Merge branch 'master' into gdamore-fixes

README.md

@@ -54,4 +54,10 @@ Bindings for various [languages](examples)
 ***
 
 ### Testing and Debugging
- - See [TESTING.md](TESTING.md)
+ - See [TESTING.md](TESTING.md)
+
+### Licensing
+ - For a [BSD]() license, build using the `lwIP` network stack with `STACK_LWIP=1`
+ - For a [GPL]() license, build using the `picoTCP` network stack with `STACK_PICO=1`
+
+ Regardless of which network stack you build with, the socket API will remain the same.

ext/lwip/COPYING

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2001, 2002 Swedish Institute of Computer Science.
+ * All rights reserved. 
+ * 
+ * Redistribution and use in source and binary forms, with or without modification, 
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ * 
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+

ext/lwip/FILES

@@ -0,0 +1,4 @@
+src/      - The source code for the lwIP TCP/IP stack.
+doc/      - The documentation for lwIP.
+
+See also the FILES file in each subdirectory.

ext/lwip/README

@@ -0,0 +1,97 @@
+INTRODUCTION
+
+lwIP is a small independent implementation of the TCP/IP protocol
+suite that has been developed by Adam Dunkels at the Computer and
+Networks Architectures (CNA) lab at the Swedish Institute of Computer
+Science (SICS).
+
+The focus of the lwIP TCP/IP implementation is to reduce the RAM usage
+while still having a full scale TCP. This making lwIP suitable for use
+in embedded systems with tens of kilobytes of free RAM and room for
+around 40 kilobytes of code ROM.
+
+
+FEATURES
+
+  * IP (Internet Protocol, IPv4 and IPv6) including packet forwarding over
+    multiple network interfaces
+  * ICMP (Internet Control Message Protocol) for network maintenance and debugging
+  * IGMP (Internet Group Management Protocol) for multicast traffic management
+  * MLD (Multicast listener discovery for IPv6). Aims to be compliant with 
+    RFC 2710. No support for MLDv2
+  * ND (Neighbor discovery and stateless address autoconfiguration for IPv6).
+    Aims to be compliant with RFC 4861 (Neighbor discovery) and RFC 4862
+    (Address autoconfiguration)
+  * UDP (User Datagram Protocol) including experimental UDP-lite extensions
+  * TCP (Transmission Control Protocol) with congestion control, RTT estimation
+    and fast recovery/fast retransmit
+  * raw/native API for enhanced performance
+  * Optional Berkeley-like socket API
+  * DNS (Domain names resolver)
+
+
+APPLICATIONS
+
+  * HTTP server with SSI and CGI
+  * SNMPv2c agent with MIB compiler (Simple Network Management Protocol)
+  * SNTP (Simple network time protocol)
+
+
+LICENSE
+
+lwIP is freely available under a BSD license.
+
+
+DEVELOPMENT
+
+lwIP has grown into an excellent TCP/IP stack for embedded devices,
+and developers using the stack often submit bug fixes, improvements,
+and additions to the stack to further increase its usefulness.
+
+Development of lwIP is hosted on Savannah, a central point for
+software development, maintenance and distribution. Everyone can
+help improve lwIP by use of Savannah's interface, Git and the
+mailing list. A core team of developers will commit changes to the
+Git source tree.
+
+The lwIP TCP/IP stack is maintained in the 'lwip' Git module and
+contributions (such as platform ports) are in the 'contrib' Git module.
+
+See doc/savannah.txt for details on Git server access for users and
+developers.
+
+The current Git trees are web-browsable:
+  http://git.savannah.gnu.org/cgit/lwip.git
+  http://git.savannah.gnu.org/cgit/lwip/lwip-contrib.git
+
+Submit patches and bugs via the lwIP project page:
+  http://savannah.nongnu.org/projects/lwip/
+
+Continuous integration builds (GCC, clang):
+  https://travis-ci.org/yarrick/lwip-merged
+
+
+DOCUMENTATION
+
+Self documentation of the source code is regularly extracted from the current
+Git sources and is available from this web page:
+  http://www.nongnu.org/lwip/
+
+There is now a constantly growin wiki about lwIP at
+  http://lwip.wikia.com/wiki/LwIP_Wiki
+
+Also, there are mailing lists you can subscribe at
+  http://savannah.nongnu.org/mail/?group=lwip
+plus searchable archives:
+  http://lists.nongnu.org/archive/html/lwip-users/
+  http://lists.nongnu.org/archive/html/lwip-devel/
+
+lwIP was originally written by Adam Dunkels:
+  http://dunkels.com/adam/
+
+Reading Adam's papers, the files in docs/, browsing the source code
+documentation and browsing the mailing list archives is a good way to
+become familiar with the design of lwIP.
+
+Adam Dunkels <adam@sics.se>
+Leon Woestenberg <leon.woestenberg@gmx.net>

ext/lwip/UPGRADING

@@ -0,0 +1,217 @@
+This file lists major changes between release versions that require
+ports or applications to be changed. Use it to update a port or an
+application written for an older version of lwIP to correctly work
+with newer versions.
+
+
+(git master)
+
+  * [Enter new changes just after this line - do not remove this line]
+
+  * TODO
+
+(2.0.0)
+
+  ++ Application changes:
+
+  * Changed netif "up" flag handling to be an administrative flag (as opposed to the previous meaning of
+    "ip4-address-valid", a netif will now not be used for transmission if not up) -> even a DHCP netif
+    has to be set "up" before starting the DHCP client
+  * Added IPv6 support (dual-stack or IPv4/IPv6 only)
+  * Changed ip_addr_t to be a union in dual-stack mode (use ip4_addr_t where referring to IPv4 only).
+  * Major rewrite of SNMP (added MIB parser that creates code stubs for custom MIBs);
+    supports SNMP2vc (experimental v3 support)
+  * Moved some core applications from contrib repository to src/apps (and include/lwip/apps)
+
+  +++ Raw API:
+    * Changed TCP listen backlog: removed tcp_accepted(), added the function pair tcp_backlog_delayed()/
+      tcp_backlog_accepted() to explicitly delay backlog handling on a connection pcb
+
+  +++ Socket API:
+    * Added an implementation for posix sendmsg()
+    * Added LWIP_FIONREAD_LINUXMODE that makes ioctl/FIONREAD return the size of the next pending datagram
+
+  ++ Port changes
+
+  +++ new files:
+    * MANY new and moved files!
+    * Continued moving stack-internal parts from abc.h to abc_priv.h in sub-folder "priv"
+      to let abc.h only contain the actual application programmer's API
+
+  +++ sys layer:
+    * Made LWIP_TCPIP_CORE_LOCKING==1 the default as it usually performs better than
+      the traditional message passing (although with LWIP_COMPAT_MUTEX you are still
+      open to priority inversion, so this is not recommended any more)
+    * Added LWIP_NETCONN_SEM_PER_THREAD to use one "op_completed" semaphore per thread
+      instead of using one per netconn (these semaphores are used even with core locking
+      enabled as some longer lasting functions like big writes still need to delay)
+
+  +++ new options:
+     * TODO
+
+  +++ new pools:
+     * Added LWIP_MEMPOOL_* (declare/init/alloc/free) to declare private memp pools
+       that share memp.c code but do not have to be made global via lwippools.h
+     * Added pools for IPv6, MPU_COMPATIBLE, dns-api, netif-api, etc.
+     * added hook LWIP_HOOK_MEMP_AVAILABLE() to get informed when a memp pool was empty and an item
+       is now available
+
+  * LWIP_DECLARE_MEMORY_ALIGNED() may be used to declare aligned memory buffers (mem/memp)
+    or to move buffers to dedicated memory using compiler attributes
+
+  * Standard C headers are used to define sized types and printf formatters
+    (disable by setting LWIP_NO_STDINT_H=1 or LWIP_NO_INTTYPES_H=1 if your compiler
+    does not support these)
+
+
+  ++ Major bugfixes/improvements
+
+  * Added IPv6 support (dual-stack or IPv4/IPv6 only)
+  * Major rewrite of PPP (incl. keep-up with apache pppd)
+  * Major rewrite of SNMP (incl. MIB parser)
+  * Fixed timing issues that might have lead to losing a DHCP lease
+  * Made rx processing path more robust against crafted errors
+  * TCP window scaling support
+  * modification of api modules to support FreeRTOS-MPU (don't pass stack-pointers to other threads)
+  * made DNS client more robust
+  * support PBUF_REF for RX packets
+  * LWIP_NETCONN_FULLDUPLEX allows netconn/sockets to be used for reading/writing from separate
+    threads each (needs LWIP_NETCONN_SEM_PER_THREAD)
+  * Moved and reorderd stats (mainly memp/mib2)
+
+(1.4.0)
+
+  ++ Application changes:
+
+  * Replaced struct ip_addr by typedef ip_addr_t (struct ip_addr is kept for
+    compatibility to old applications, but will be removed in the future).
+
+  * Renamed mem_realloc() to mem_trim() to prevent confusion with realloc()
+
+  +++ Raw API:
+    * Changed the semantics of tcp_close() (since it was rather a
+      shutdown before): Now the application does *NOT* get any calls to the recv
+      callback (aside from NULL/closed) after calling tcp_close()
+
+    * When calling tcp_abort() from a raw API TCP callback function,
+      make sure you return ERR_ABRT to prevent accessing unallocated memory.
+      (ERR_ABRT now means the applicaiton has called tcp_abort!)
+
+  +++ Netconn API:
+    * Changed netconn_receive() and netconn_accept() to return
+      err_t, not a pointer to new data/netconn.
+
+  +++ Socket API:
+    * LWIP_SO_RCVTIMEO: when accept() or recv() time out, they
+      now set errno to EWOULDBLOCK/EAGAIN, not ETIMEDOUT.
+
+    * Added a minimal version of posix fctl() to have a
+      standardised way to set O_NONBLOCK for nonblocking sockets.
+
+  +++ all APIs:
+    * correctly implemented SO(F)_REUSEADDR
+
+  ++ Port changes
+
+  +++ new files:
+
+    * Added 4 new files: def.c, timers.c, timers.h, tcp_impl.h:
+
+    * Moved stack-internal parts of tcp.h to tcp_impl.h, tcp.h now only contains
+      the actual application programmer's API
+  
+    * Separated timer implementation from sys.h/.c, moved to timers.h/.c;
+      Added timer implementation for NO_SYS==1, set NO_SYS_NO_TIMERS==1 if you
+      still want to use your own timer implementation for NO_SYS==0 (as before).
+
+  +++ sys layer:
+
+    * Converted mbox- and semaphore-functions to take pointers to sys_mbox_t/
+      sys_sem_t;
+
+    * Converted sys_mbox_new/sys_sem_new to take pointers and return err_t;
+
+    * Added Mutex concept in sys_arch (define LWIP_COMPAT_MUTEX to let sys.h use
+      binary semaphores instead of mutexes - as before)
+
+  +++ new options:
+
+     * Don't waste memory when chaining segments, added option TCP_OVERSIZE to
+       prevent creating many small pbufs when calling tcp_write with many small
+       blocks of data. Instead, pbufs are allocated larger than needed and the
+       space is used for later calls to tcp_write.
+
+     * Added LWIP_NETIF_TX_SINGLE_PBUF to always copy to try to create single pbufs
+       in tcp_write/udp_send.
+
+    * Added an additional option LWIP_ETHERNET to support ethernet without ARP
+      (necessary for pure PPPoE)
+
+    * Add MEMP_SEPARATE_POOLS to place memory pools in separate arrays. This may
+      be used to place these pools into user-defined memory by using external
+      declaration.
+
+    * Added TCP_SNDQUEUELOWAT corresponding to TCP_SNDLOWAT
+
+  +++ new pools:
+
+     * Netdb uses a memp pool for allocating memory when getaddrinfo() is called,
+       so MEMP_NUM_NETDB has to be set accordingly.
+
+     * DNS_LOCAL_HOSTLIST_IS_DYNAMIC uses a memp pool instead of the heap, so
+       MEMP_NUM_LOCALHOSTLIST has to be set accordingly.
+
+     * Snmp-agent uses a memp pools instead of the heap, so MEMP_NUM_SNMP_* have
+       to be set accordingly.
+
+     * PPPoE uses a MEMP pool instead of the heap, so MEMP_NUM_PPPOE_INTERFACES
+       has to be set accordingly
+
+  * Integrated loopif into netif.c - loopif does not have to be created by the
+    port any more, just define LWIP_HAVE_LOOPIF to 1.
+
+  * Added define LWIP_RAND() for lwip-wide randomization (needs to be defined
+    in cc.h, e.g. used by igmp)
+
+  * Added printf-formatter X8_F to printf u8_t as hex
+
+  * The heap now may be moved to user-defined memory by defining
+    LWIP_RAM_HEAP_POINTER as a void pointer to that memory's address
+
+  * added autoip_set_struct() and dhcp_set_struct() to let autoip and dhcp work
+    with user-allocated structs instead of calling mem_malloc
+
+  * Added const char* name to mem- and memp-stats for easier debugging.
+
+  * Calculate the TCP/UDP checksum while copying to only fetch data once:
+    Define LWIP_CHKSUM_COPY to a memcpy-like function that returns the checksum
+
+  * Added SO_REUSE_RXTOALL to pass received UDP broadcast/multicast packets to
+    more than one pcb.
+
+  * Changed the semantics of ARP_QUEUEING==0: ARP_QUEUEING now cannot be turned
+    off any more, if this is set to 0, only one packet (the most recent one) is
+    queued (like demanded by RFC 1122).
+
+  
+  ++ Major bugfixes/improvements
+
+  * Implemented tcp_shutdown() to only shut down one end of a connection
+  * Implemented shutdown() at socket- and netconn-level
+  * Added errorset support to select() + improved select speed overhead
+  * Merged pppd to v2.3.11 (including some backported bugfixes from 2.4.x)
+  * Added timer implementation for NO_SYS==1 (may be disabled with NO_SYS_NO_TIMERS==1
+  * Use macros defined in ip_addr.h to work with IP addresses
+  * Implemented many nonblocking socket/netconn functions
+  * Fixed ARP input processing: only add a new entry if a request was directed as us
+  * mem_realloc() to mem_trim() to prevent confusion with realloc()
+  * Some improvements for AutoIP (don't route/forward link-local addresses, don't break
+    existing connections when assigning a routable address)
+  * Correctly handle remote side overrunning our rcv_wnd in ooseq case
+  * Removed packing from ip_addr_t, the packed version is now only used in protocol headers
+  * Corrected PBUF_POOL_BUFSIZE for ports where ETH_PAD_SIZE > 0
+  * Added support for static ARP table entries
+
+(STABLE-1.3.2)
+
+  * initial version of this file

ext/lwip/doc/FILES

@@ -0,0 +1,6 @@
+savannah.txt   - How to obtain the current development source code.
+contrib.txt    - How to contribute to lwIP as a developer.
+rawapi.txt     - The documentation for the core API of lwIP.
+                 Also provides an overview about the other APIs and multithreading.
+snmp_agent.txt - The documentation for the lwIP SNMP agent.
+sys_arch.txt   - The documentation for a system abstraction layer of lwIP.

ext/lwip/doc/contrib.txt

@@ -0,0 +1,58 @@
+1 Introduction
+
+This document describes some guidelines for people participating
+in lwIP development.
+
+2 How to contribute to lwIP
+
+Here is a short list of suggestions to anybody working with lwIP and 
+trying to contribute bug reports, fixes, enhancements, platform ports etc.
+First of all as you may already know lwIP is a volunteer project so feedback
+to fixes or questions might often come late. Hopefully the bug and patch tracking 
+features of Savannah help us not lose users' input.
+
+2.1 Source code style:
+
+1. do not use tabs.
+2. indentation is two spaces per level (i.e. per tab).
+3. end debug messages with a trailing newline (\n).
+4. one space between keyword and opening bracket.
+5. no space between function and opening bracket.
+6. one space and no newline before opening curly braces of a block.
+7. closing curly brace on a single line.
+8. spaces surrounding assignment and comparisons.
+9. don't initialize static and/or global variables to zero, the compiler takes care of that.
+10. use current source code style as further reference.
+
+2.2 Source code documentation style:
+
+1. JavaDoc compliant and Doxygen compatible.
+2. Function documentation above functions in .c files, not .h files.
+   (This forces you to synchronize documentation and implementation.)
+3. Use current documentation style as further reference.
+ 
+2.3 Bug reports and patches:
+
+1. Make sure you are reporting bugs or send patches against the latest
+   sources. (From the latest release and/or the current Git sources.)
+2. If you think you found a bug make sure it's not already filed in the
+   bugtracker at Savannah.
+3. If you have a fix put the patch on Savannah. If it is a patch that affects
+   both core and arch specific stuff please separate them so that the core can
+   be applied separately while leaving the other patch 'open'. The prefered way
+   is to NOT touch archs you can't test and let maintainers take care of them.
+   This is a good way to see if they are used at all - the same goes for unix
+   netifs except tapif.
+4. Do not file a bug and post a fix to it to the patch area. Either a bug report
+   or a patch will be enough.
+   If you correct an existing bug then attach the patch to the bug rather than creating a new entry in the patch area.
+5. Patches should be specific to a single change or to related changes. Do not mix bugfixes with spelling and other
+   trivial fixes unless the bugfix is trivial too. Do not reorganize code and rename identifiers in the same patch you
+   change behaviour if not necessary. A patch is easier to read and understand if it's to the point and short than
+   if it's not to the point and long :) so the chances for it to be applied are greater. 
+
+2.4 Platform porters:
+
+1. If you have ported lwIP to a platform (an OS, a uC/processor or a combination of these) and
+   you think it could benefit others[1] you might want discuss this on the mailing list. You
+   can also ask for Git access to submit and maintain your port in the contrib Git module.

ext/lwip/doc/doxygen/generate.bat

@@ -0,0 +1 @@
+doxygen lwip.Doxyfile

ext/lwip/doc/doxygen/generate.sh

@@ -0,0 +1 @@
+doxygen lwip.Doxyfile

ext/lwip/doc/doxygen/main_page.h

@@ -0,0 +1,32 @@
+/**
+ * @defgroup lwip lwIP
+ *
+ * @defgroup infrastructure Infrastructure
+ *
+ * @defgroup callbackstyle_api Callback-style APIs
+ * Non thread-safe APIs, callback style for maximum performance and minimum
+ * memory footprint.
+ * 
+ * @defgroup threadsafe_api Thread-safe APIs
+ * Thread-safe APIs, blocking functions. More overhead, but can be called
+ * from any thread except TCPIP thread.
+ * 
+ * @defgroup addons Addons
+ * 
+ * @defgroup apps Applications
+ */
+
+/**
+ * @mainpage Overview
+ * @verbinclude "README"
+ */
+
+/**
+ * @page upgrading Upgrading
+ * @verbinclude "UPGRADING"
+ */
+
+/**
+ * @page contrib How to contribute to lwIP
+ * @verbinclude "contrib.txt"
+ */

ext/lwip/doc/ppp.txt

@@ -0,0 +1,529 @@
+PPP interface for lwIP
+
+Author: Sylvain Rochet
+
+Table of Contents:
+
+1 - Supported PPP protocols and features
+2 - Raw API PPP example for all protocols
+3 - PPPoS input path (raw API, IRQ safe API, TCPIP API)
+4 - Thread safe PPP API (PPPAPI)
+5 - Notify phase callback (PPP_NOTIFY_PHASE)
+6 - Upgrading from lwIP <= 1.4.x to lwIP >= 2.0.x
+
+
+
+1 Supported PPP protocols and features
+======================================
+
+Supported Low level protocols:
+* PPP over serial using HDLC-like framing, such as wired dialup modems
+  or mobile telecommunications GPRS/EDGE/UMTS/HSPA+/LTE modems
+* PPP over Ethernet, such as xDSL modems
+* PPP over L2TP (Layer 2 Tunneling Protocol) LAC (L2TP Access Concentrator),
+  IP tunnel over UDP, such as VPN access
+
+Supported auth protocols:
+* PAP, Password Authentication Protocol
+* CHAP, Challenge-Handshake Authentication Protocol, also known as CHAP-MD5
+* MSCHAPv1, Microsoft version of CHAP, version 1
+* MSCHAPv2, Microsoft version of CHAP, version 2
+* EAP, Extensible Authentication Protocol
+
+Supported address protocols:
+* IPCP, IP Control Protocol, IPv4 addresses negotiation
+* IP6CP, IPv6 Control Protocol, IPv6 link-local addresses negotiation
+
+Supported encryption protocols:
+* MPPE, Microsoft Point-to-Point Encryption
+
+Supported compression or miscellaneous protocols, for serial links only:
+* PFC, Protocol Field Compression
+* ACFC, Address-and-Control-Field-Compression
+* ACCM, Asynchronous-Control-Character-Map
+* VJ, Van Jacobson TCP/IP Header Compression
+
+
+
+2 Raw API PPP example for all protocols
+=======================================
+
+As usual, raw API for lwIP means the lightweight API which *MUST* only be used
+for NO_SYS=1 systems or called inside lwIP core thread for NO_SYS=0 systems.
+
+/*
+ * Globals
+ * =======
+ */
+
+/* The PPP control block */
+ppp_pcb *ppp;
+
+/* The PPP IP interface */
+struct netif ppp_netif;
+
+
+/*
+ * PPP status callback
+ * ===================
+ *
+ * PPP status callback is called on PPP status change (up, down, …) from lwIP
+ * core thread
+ */
+
+/* PPP status callback example */
+static void status_cb(ppp_pcb *pcb, int err_code, void *ctx) {
+  struct netif *pppif = ppp_netif(pcb);
+  LWIP_UNUSED_ARG(ctx);
+
+  switch(err_code) {
+    case PPPERR_NONE: {
+#if LWIP_DNS
+      ip_addr_t ns;
+#endif /* LWIP_DNS */
+      printf("status_cb: Connected\n");
+#if PPP_IPV4_SUPPORT
+      printf("   our_ipaddr  = %s\n", ipaddr_ntoa(&pppif->ip_addr));
+      printf("   his_ipaddr  = %s\n", ipaddr_ntoa(&pppif->gw));
+      printf("   netmask     = %s\n", ipaddr_ntoa(&pppif->netmask));
+#if LWIP_DNS
+      ns = dns_getserver(0);
+      printf("   dns1        = %s\n", ipaddr_ntoa(&ns));
+      ns = dns_getserver(1);
+      printf("   dns2        = %s\n", ipaddr_ntoa(&ns));
+#endif /* LWIP_DNS */
+#endif /* PPP_IPV4_SUPPORT */
+#if PPP_IPV6_SUPPORT
+      printf("   our6_ipaddr = %s\n", ip6addr_ntoa(netif_ip6_addr(pppif, 0)));
+#endif /* PPP_IPV6_SUPPORT */
+      break;
+    }
+    case PPPERR_PARAM: {
+      printf("status_cb: Invalid parameter\n");
+      break;
+    }
+    case PPPERR_OPEN: {
+      printf("status_cb: Unable to open PPP session\n");
+      break;
+    }
+    case PPPERR_DEVICE: {
+      printf("status_cb: Invalid I/O device for PPP\n");
+      break;
+    }
+    case PPPERR_ALLOC: {
+      printf("status_cb: Unable to allocate resources\n");
+      break;
+    }
+    case PPPERR_USER: {
+      printf("status_cb: User interrupt\n");
+      break;
+    }
+    case PPPERR_CONNECT: {
+      printf("status_cb: Connection lost\n");
+      break;
+    }
+    case PPPERR_AUTHFAIL: {
+      printf("status_cb: Failed authentication challenge\n");
+      break;
+    }
+    case PPPERR_PROTOCOL: {
+      printf("status_cb: Failed to meet protocol\n");
+      break;
+    }
+    case PPPERR_PEERDEAD: {
+      printf("status_cb: Connection timeout\n");
+      break;
+    }
+    case PPPERR_IDLETIMEOUT: {
+      printf("status_cb: Idle Timeout\n");
+      break;
+    }
+    case PPPERR_CONNECTTIME: {
+      printf("status_cb: Max connect time reached\n");
+      break;
+    }
+    case PPPERR_LOOPBACK: {
+      printf("status_cb: Loopback detected\n");
+      break;
+    }
+    default: {
+      printf("status_cb: Unknown error code %d\n", err_code);
+      break;
+    }
+  }
+
+/*
+ * This should be in the switch case, this is put outside of the switch
+ * case for example readability.
+ */
+
+  if (err_code == PPPERR_NONE) {
+    return;
+  }
+
+  /* ppp_close() was previously called, don't reconnect */
+  if (err_code == PPPERR_USER) {
+    /* ppp_free(); -- can be called here */
+    return;
+  }
+
+  /*
+   * Try to reconnect in 30 seconds, if you need a modem chatscript you have
+   * to do a much better signaling here ;-)
+   */
+  ppp_connect(pcb, 30);
+  /* OR ppp_listen(pcb); */
+}
+
+
+/*
+ * Creating a new PPPoS session
+ * ============================
+ *
+ * In lwIP, PPPoS is not PPPoSONET, in lwIP PPPoS is PPPoSerial.
+ */
+
+#include "netif/ppp/pppos.h"
+
+/*
+ * PPPoS serial output callback
+ *
+ * ppp_pcb, PPP control block
+ * data, buffer to write to serial port
+ * len, length of the data buffer
+ * ctx, optional user-provided callback context pointer
+ *
+ * Return value: len if write succeed
+ */
+static u32_t output_cb(ppp_pcb *pcb, u8_t *data, u32_t len, void *ctx) {
+  return uart_write(UART, data, len);
+}
+
+/*
+ * Create a new PPPoS interface
+ *
+ * ppp_netif, netif to use for this PPP link, i.e. PPP IP interface
+ * output_cb, PPPoS serial output callback
+ * status_cb, PPP status callback, called on PPP status change (up, down, …)
+ * ctx_cb, optional user-provided callback context pointer
+ */
+ppp = pppos_create(&ppp_netif,
+       output_cb, status_cb, ctx_cb);
+
+
+/*
+ * Creating a new PPPoE session
+ * ============================
+ */
+
+#include "netif/ppp/pppoe.h"
+
+/*
+ * Create a new PPPoE interface
+ *
+ * ppp_netif, netif to use for this PPP link, i.e. PPP IP interface
+ * ethif, already existing and setup Ethernet interface to use
+ * service_name, PPPoE service name discriminator (not supported yet)
+ * concentrator_name, PPPoE concentrator name discriminator (not supported yet)
+ * status_cb, PPP status callback, called on PPP status change (up, down, …)
+ * ctx_cb, optional user-provided callback context pointer
+ */
+ppp = pppoe_create(&ppp_netif,
+       &ethif,
+       service_name, concentrator_name,
+       status_cb, ctx_cb);
+
+
+/*
+ * Creating a new PPPoL2TP session
+ * ===============================
+ */
+
+#include "netif/ppp/pppol2tp.h"
+
+/*
+ * Create a new PPPoL2TP interface
+ *
+ * ppp_netif, netif to use for this PPP link, i.e. PPP IP interface
+ * netif, optional already existing and setup output netif, necessary if you
+ *        want to set this interface as default route to settle the chicken
+ *        and egg problem with VPN links
+ * ipaddr, IP to connect to
+ * port, UDP port to connect to (usually 1701)
+ * secret, L2TP secret to use
+ * secret_len, size in bytes of the L2TP secret
+ * status_cb, PPP status callback, called on PPP status change (up, down, …)
+ * ctx_cb, optional user-provided callback context pointer
+ */
+ppp = pppol2tp_create(&ppp_netif,
+       struct netif *netif, ip_addr_t *ipaddr, u16_t port,
+       u8_t *secret, u8_t secret_len,
+       ppp_link_status_cb_fn link_status_cb, void *ctx_cb);
+
+
+/*
+ * Initiate PPP client connection
+ * ==============================
+ */
+
+/* Set this interface as default route */
+ppp_set_default(ppp);
+
+/*
+ * Basic PPP client configuration. Can only be set if PPP session is in the
+ * dead state (i.e. disconnected). We don't need to provide thread-safe
+ * equivalents through PPPAPI because those helpers are only changing
+ * structure members while session is inactive for lwIP core. Configuration
+ * only need to be done once.
+ */
+
+/* Ask the peer for up to 2 DNS server addresses. */
+ppp_set_usepeerdns(ppp, 1);
+
+/* Auth configuration, this is pretty self-explanatory */
+ppp_set_auth(ppp, PPPAUTHTYPE_ANY, "login", "password");
+
+/*
+ * Initiate PPP negotiation, without waiting (holdoff=0), can only be called
+ * if PPP session is in the dead state (i.e. disconnected).
+ */
+u16_t holdoff = 0;
+ppp_connect(ppp, holdoff);
+
+
+/*
+ * Initiate PPP server listener
+ * ============================
+ */
+
+/*
+ * Basic PPP server configuration. Can only be set if PPP session is in the
+ * dead state (i.e. disconnected). We don't need to provide thread-safe
+ * equivalents through PPPAPI because those helpers are only changing
+ * structure members while session is inactive for lwIP core. Configuration
+ * only need to be done once.
+ */
+ip4_addr_t addr;
+
+/* Set our address */
+IP4_ADDR(&addr, 192,168,0,1);
+ppp_set_ipcp_ouraddr(ppp, &addr);
+
+/* Set peer(his) address */
+IP4_ADDR(&addr, 192,168,0,2);
+ppp_set_ipcp_hisaddr(ppp, &addr);
+
+/* Set primary DNS server */
+IP4_ADDR(&addr, 192,168,10,20);
+ppp_set_ipcp_dnsaddr(ppp, 0, &addr);
+
+/* Set secondary DNS server */
+IP4_ADDR(&addr, 192,168,10,21);
+ppp_set_ipcp_dnsaddr(ppp, 1, &addr);
+
+/* Auth configuration, this is pretty self-explanatory */
+ppp_set_auth(ppp, PPPAUTHTYPE_ANY, "login", "password");
+
+/* Require peer to authenticate */
+ppp_set_auth_required(ppp, 1);
+
+/*
+ * Only for PPPoS, the PPP session should be up and waiting for input.
+ *
+ * Note: for PPPoS, ppp_connect() and ppp_listen() are actually the same thing.
+ * The listen call is meant for future support of PPPoE and PPPoL2TP server
+ * mode, where we will need to negotiate the incoming PPPoE session or L2TP
+ * session before initiating PPP itself. We need this call because there is
+ * two passive modes for PPPoS, ppp_set_passive and ppp_set_silent.
+ */
+ppp_set_silent(pppos, 1);
+
+/*
+ * Initiate PPP listener (i.e. wait for an incoming connection), can only
+ * be called if PPP session is in the dead state (i.e. disconnected).
+ */
+ppp_listen(ppp);
+
+
+/*
+ * Closing PPP connection
+ * ======================
+ */
+
+/*
+ * Initiate the end of the PPP session, without carrier lost signal
+ * (nocarrier=0), meaning a clean shutdown of PPP protocols.
+ * You can call this function at anytime.
+ */
+u8_t nocarrier = 0;
+ppp_close(ppp, nocarrier);
+/*
+ * Then you must wait your status_cb() to be called, it may takes from a few
+ * seconds to several tens of seconds depending on the current PPP state.
+ */
+
+/*
+ * Freeing a PPP connection
+ * ========================
+ */
+
+/*
+ * Free the PPP control block, can only be called if PPP session is in the
+ * dead state (i.e. disconnected). You need to call ppp_close() before.
+ */
+ppp_free(ppp);
+
+
+
+3 PPPoS input path (raw API, IRQ safe API, TCPIP API)
+=====================================================
+
+Received data on serial port should be sent to lwIP using the pppos_input()
+function or the pppos_input_tcpip() function.
+
+If NO_SYS is 1 and if PPP_INPROC_IRQ_SAFE is 0 (the default), pppos_input()
+is not IRQ safe and then *MUST* only be called inside your main loop.
+
+Whatever the NO_SYS value, if PPP_INPROC_IRQ_SAFE is 1, pppos_input() is IRQ
+safe and can be safely called from an interrupt context, using that is going
+to reduce your need of buffer if pppos_input() is called byte after byte in
+your rx serial interrupt.
+
+if NO_SYS is 0, the thread safe way outside an interrupt context is to use
+the pppos_input_tcpip() function to pass input data to the lwIP core thread
+using the TCPIP API. This is thread safe in all cases but you should avoid
+passing data byte after byte because it uses heavy locking (mailbox) and it
+allocates pbuf, better fill them !
+
+if NO_SYS is 0 and if PPP_INPROC_IRQ_SAFE is 1, you may also use pppos_input()
+from an RX thread, however pppos_input() is not thread safe by itself. You can
+do that *BUT* you should NEVER call pppos_connect(), pppos_listen() and
+ppp_free() if pppos_input() can still be running, doing this is NOT thread safe
+at all. Using PPP_INPROC_IRQ_SAFE from an RX thread is discouraged unless you
+really know what you are doing, your move ;-)
+
+
+/*
+ * Fonction to call for received data
+ *
+ * ppp, PPP control block
+ * buffer, input buffer
+ * buffer_len, buffer length in bytes
+ */
+void pppos_input(ppp, buffer, buffer_len);
+
+or
+
+void pppos_input_tcpip(ppp, buffer, buffer_len);
+
+
+
+4 Thread safe PPP API (PPPAPI)
+==============================
+
+There is a thread safe API for all corresponding ppp_* functions, you have to
+enable LWIP_PPP_API in your lwipopts.h file, then see
+include/netif/ppp/pppapi.h, this is actually pretty obvious.
+
+
+
+5 Notify phase callback (PPP_NOTIFY_PHASE)
+==========================================
+
+Notify phase callback, enabled using the PPP_NOTIFY_PHASE config option, let
+you configure a callback that is called on each PPP internal state change.
+This is different from the status callback which only warns you about
+up(running) and down(dead) events.
+
+Notify phase callback can be used, for example, to set a LED pattern depending
+on the current phase of the PPP session. Here is a callback example which
+tries to mimic what we usually see on xDSL modems while they are negotiating
+the link, which should be self-explanatory:
+
+static void ppp_notify_phase_cb(ppp_pcb *pcb, u8_t phase, void *ctx) {
+  switch (phase) {
+
+  /* Session is down (either permanently or briefly) */
+  case PPP_PHASE_DEAD:
+    led_set(PPP_LED, LED_OFF);
+    break;
+
+  /* We are between two sessions */
+  case PPP_PHASE_HOLDOFF:
+    led_set(PPP_LED, LED_SLOW_BLINK);
+    break;
+
+  /* Session just started */
+  case PPP_PHASE_INITIALIZE:
+    led_set(PPP_LED, LED_FAST_BLINK);
+    break;
+
+  /* Session is running */
+  case PPP_PHASE_RUNNING:
+    led_set(PPP_LED, LED_ON);
+    break;
+
+  default:
+    break;
+  }
+}
+
+
+
+6 Upgrading from lwIP <= 1.4.x to lwIP >= 2.0.x
+===============================================
+
+PPP API was fully reworked between 1.4.x and 2.0.x releases. However porting
+from previous lwIP version is pretty easy:
+
+* Previous PPP API used an integer to identify PPP sessions, we are now
+  using ppp_pcb* control block, therefore all functions changed from "int ppp"
+  to "ppp_pcb *ppp"
+
+* struct netif was moved outside the PPP structure, you have to provide a netif
+  for PPP interface in pppoX_create() functions
+
+* PPP session are not started automatically after you created them anymore,
+  you have to call ppp_connect(), this way you can configure the session before
+  starting it.
+
+* Previous PPP API used CamelCase, we are now using snake_case.
+
+* Previous PPP API mixed PPPoS and PPPoE calls, this isn't the case anymore,
+  PPPoS functions are now prefixed pppos_ and PPPoE functions are now prefixed
+  pppoe_, common functions are now prefixed ppp_.
+
+* New PPPERR_ error codes added, check you have all of them in your status
+  callback function
+
+* Only the following include files should now be used in user application:
+  #include "netif/ppp/pppapi.h"
+  #include "netif/ppp/pppos.h"
+  #include "netif/ppp/pppoe.h"
+  #include "netif/ppp/pppol2tp.h"
+
+  Functions from ppp.h can be used, but you don't need to include this header
+  file as it is already included by above header files.
+
+* PPP_INPROC_OWNTHREAD was broken by design and was removed, you have to create
+  your own serial rx thread
+
+* PPP_INPROC_MULTITHREADED option was misnamed and confusing and was renamed
+  PPP_INPROC_IRQ_SAFE, please read the "PPPoS input path" documentation above
+  because you might have been fooled by that
+
+* If you used tcpip_callback_with_block() on ppp_ functions you may wish to use
+  the PPPAPI API instead.
+
+* ppp_sighup and ppp_close functions were merged using an optional argument
+  "nocarrier" on ppp_close.
+
+* DNS servers are now only remotely asked if LWIP_DNS is set and if
+  ppp_set_usepeerdns() is set to true, they are now automatically registered
+  using the dns_setserver() function so you don't need to do that in the PPP
+  callback anymore.
+
+* PPPoS does not use the SIO API anymore, as such it now requires a serial
+  output callback in place of sio_write
+
+* PPP_MAXIDLEFLAG is now in ms instead of jiffies

ext/lwip/doc/rawapi.txt

@@ -0,0 +1,506 @@
+Raw TCP/IP interface for lwIP
+
+Authors: Adam Dunkels, Leon Woestenberg, Christiaan Simons
+
+lwIP provides three Application Program's Interfaces (APIs) for programs
+to use for communication with the TCP/IP code:
+* low-level "core" / "callback" or "raw" API.
+* higher-level "sequential" API.
+* BSD-style socket API.
+
+The raw API (sometimes called native API) is an event-driven API designed
+to be used without an operating system that implements zero-copy send and
+receive. This API is also used by the core stack for interaction between
+the various protocols. It is the only API available when running lwIP
+without an operating system.
+
+The sequential API provides a way for ordinary, sequential, programs
+to use the lwIP stack. It is quite similar to the BSD socket API. The
+model of execution is based on the blocking open-read-write-close
+paradigm. Since the TCP/IP stack is event based by nature, the TCP/IP
+code and the application program must reside in different execution
+contexts (threads).
+
+The socket API is a compatibility API for existing applications,
+currently it is built on top of the sequential API. It is meant to
+provide all functions needed to run socket API applications running
+on other platforms (e.g. unix / windows etc.). However, due to limitations
+in the specification of this API, there might be incompatibilities
+that require small modifications of existing programs.
+
+** Multithreading
+
+lwIP started targeting single-threaded environments. When adding multi-
+threading support, instead of making the core thread-safe, another
+approach was chosen: there is one main thread running the lwIP core
+(also known as the "tcpip_thread"). When running in a multithreaded
+environment, raw API functions MUST only be called from the core thread
+since raw API functions are not protected from concurrent access (aside
+from pbuf- and memory management functions). Application threads using
+the sequential- or socket API communicate with this main thread through
+message passing.
+
+      As such, the list of functions that may be called from
+      other threads or an ISR is very limited! Only functions
+      from these API header files are thread-safe:
+      - api.h
+      - netbuf.h
+      - netdb.h
+      - netifapi.h
+      - pppapi.h
+      - sockets.h
+      - sys.h
+
+      Additionaly, memory (de-)allocation functions may be
+      called from multiple threads (not ISR!) with NO_SYS=0
+      since they are protected by SYS_LIGHTWEIGHT_PROT and/or
+      semaphores.
+
+      Netconn or Socket API functions are thread safe against the
+      core thread but they are not reentrant at the control block
+      granularity level. That is, a UDP or TCP control block must
+      not be shared among multiple threads without proper locking.
+
+      If SYS_LIGHTWEIGHT_PROT is set to 1 and
+      LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT is set to 1,
+      pbuf_free() may also be called from another thread or
+      an ISR (since only then, mem_free - for PBUF_RAM - may
+      be called from an ISR: otherwise, the HEAP is only
+      protected by semaphores).
+
+
+** The remainder of this document discusses the "raw" API. **
+
+The raw TCP/IP interface allows the application program to integrate
+better with the TCP/IP code. Program execution is event based by
+having callback functions being called from within the TCP/IP
+code. The TCP/IP code and the application program both run in the same
+thread. The sequential API has a much higher overhead and is not very
+well suited for small systems since it forces a multithreaded paradigm
+on the application.
+
+The raw TCP/IP interface is not only faster in terms of code execution
+time but is also less memory intensive. The drawback is that program
+development is somewhat harder and application programs written for
+the raw TCP/IP interface are more difficult to understand. Still, this
+is the preferred way of writing applications that should be small in
+code size and memory usage.
+
+All APIs can be used simultaneously by different application
+programs. In fact, the sequential API is implemented as an application
+program using the raw TCP/IP interface.
+
+Do not confuse the lwIP raw API with raw Ethernet or IP sockets.
+The former is a way of interfacing the lwIP network stack (including
+TCP and UDP), the later refers to processing raw Ethernet or IP data
+instead of TCP connections or UDP packets.
+
+Raw API applications may never block since all packet processing
+(input and output) as well as timer processing (TCP mainly) is done
+in a single execution context.
+
+--- Callbacks
+
+Program execution is driven by callbacks functions, which are then
+invoked by the lwIP core when activity related to that application
+occurs. A particular application may register to be notified via a
+callback function for events such as incoming data available, outgoing
+data sent, error notifications, poll timer expiration, connection
+closed, etc. An application can provide a callback function to perform
+processing for any or all of these events. Each callback is an ordinary
+C function that is called from within the TCP/IP code. Every callback
+function is passed the current TCP or UDP connection state as an
+argument. Also, in order to be able to keep program specific state,
+the callback functions are called with a program specified argument
+that is independent of the TCP/IP state.
+
+The function for setting the application connection state is:
+
+- void tcp_arg(struct tcp_pcb *pcb, void *arg)
+
+  Specifies the program specific state that should be passed to all
+  other callback functions. The "pcb" argument is the current TCP
+  connection control block, and the "arg" argument is the argument
+  that will be passed to the callbacks.
+
+  
+--- TCP connection setup
+
+The functions used for setting up connections is similar to that of
+the sequential API and of the BSD socket API. A new TCP connection
+identifier (i.e., a protocol control block - PCB) is created with the
+tcp_new() function. This PCB can then be either set to listen for new
+incoming connections or be explicitly connected to another host.
+
+- struct tcp_pcb *tcp_new(void)
+
+  Creates a new connection identifier (PCB). If memory is not
+  available for creating the new pcb, NULL is returned.
+
+- err_t tcp_bind(struct tcp_pcb *pcb, ip_addr_t *ipaddr,
+                 u16_t port)
+
+  Binds the pcb to a local IP address and port number. The IP address
+  can be specified as IP_ADDR_ANY in order to bind the connection to
+  all local IP addresses.
+
+  If another connection is bound to the same port, the function will
+  return ERR_USE, otherwise ERR_OK is returned.
+
+- struct tcp_pcb *tcp_listen(struct tcp_pcb *pcb)
+
+  Commands a pcb to start listening for incoming connections. When an
+  incoming connection is accepted, the function specified with the
+  tcp_accept() function will be called. The pcb will have to be bound
+  to a local port with the tcp_bind() function.
+
+  The tcp_listen() function returns a new connection identifier, and
+  the one passed as an argument to the function will be
+  deallocated. The reason for this behavior is that less memory is
+  needed for a connection that is listening, so tcp_listen() will
+  reclaim the memory needed for the original connection and allocate a
+  new smaller memory block for the listening connection.
+
+  tcp_listen() may return NULL if no memory was available for the
+  listening connection. If so, the memory associated with the pcb
+  passed as an argument to tcp_listen() will not be deallocated.
+
+- struct tcp_pcb *tcp_listen_with_backlog(struct tcp_pcb *pcb, u8_t backlog)
+
+  Same as tcp_listen, but limits the number of outstanding connections
+  in the listen queue to the value specified by the backlog argument.
+  To use it, your need to set TCP_LISTEN_BACKLOG=1 in your lwipopts.h.
+
+- void tcp_accepted(struct tcp_pcb *pcb)
+
+  Inform lwIP that an incoming connection has been accepted. This would
+  usually be called from the accept callback. This allows lwIP to perform
+  housekeeping tasks, such as allowing further incoming connections to be
+  queued in the listen backlog.
+  ATTENTION: the PCB passed in must be the listening pcb, not the pcb passed
+  into the accept callback!
+
+- void tcp_accept(struct tcp_pcb *pcb,
+                  err_t (* accept)(void *arg, struct tcp_pcb *newpcb,
+                                   err_t err))
+
+  Specified the callback function that should be called when a new
+  connection arrives on a listening connection.
+
+- err_t tcp_connect(struct tcp_pcb *pcb, ip_addr_t *ipaddr,
+                    u16_t port, err_t (* connected)(void *arg,
+                                                    struct tcp_pcb *tpcb,
+                                                    err_t err));
+
+  Sets up the pcb to connect to the remote host and sends the
+  initial SYN segment which opens the connection. 
+
+  The tcp_connect() function returns immediately; it does not wait for
+  the connection to be properly setup. Instead, it will call the
+  function specified as the fourth argument (the "connected" argument)
+  when the connection is established. If the connection could not be
+  properly established, either because the other host refused the
+  connection or because the other host didn't answer, the "err"
+  callback function of this pcb (registered with tcp_err, see below)
+  will be called.
+
+  The tcp_connect() function can return ERR_MEM if no memory is
+  available for enqueueing the SYN segment. If the SYN indeed was
+  enqueued successfully, the tcp_connect() function returns ERR_OK.
+
+
+--- Sending TCP data
+
+TCP data is sent by enqueueing the data with a call to
+tcp_write(). When the data is successfully transmitted to the remote
+host, the application will be notified with a call to a specified
+callback function.
+
+- err_t tcp_write(struct tcp_pcb *pcb, const void *dataptr, u16_t len,
+                  u8_t apiflags)
+
+  Enqueues the data pointed to by the argument dataptr. The length of
+  the data is passed as the len parameter. The apiflags can be one or more of:
+  - TCP_WRITE_FLAG_COPY: indicates whether the new memory should be allocated
+    for the data to be copied into. If this flag is not given, no new memory
+    should be allocated and the data should only be referenced by pointer. This
+    also means that the memory behind dataptr must not change until the data is
+    ACKed by the remote host
+  - TCP_WRITE_FLAG_MORE: indicates that more data follows. If this is omitted,
+    the PSH flag is set in the last segment created by this call to tcp_write.
+    If this flag is given, the PSH flag is not set.
+
+  The tcp_write() function will fail and return ERR_MEM if the length
+  of the data exceeds the current send buffer size or if the length of
+  the queue of outgoing segment is larger than the upper limit defined
+  in lwipopts.h. The number of bytes available in the output queue can
+  be retrieved with the tcp_sndbuf() function.
+
+  The proper way to use this function is to call the function with at
+  most tcp_sndbuf() bytes of data. If the function returns ERR_MEM,
+  the application should wait until some of the currently enqueued
+  data has been successfully received by the other host and try again.
+
+- void tcp_sent(struct tcp_pcb *pcb,
+                err_t (* sent)(void *arg, struct tcp_pcb *tpcb,
+                u16_t len))
+
+  Specifies the callback function that should be called when data has
+  successfully been received (i.e., acknowledged) by the remote
+  host. The len argument passed to the callback function gives the
+  amount bytes that was acknowledged by the last acknowledgment.
+
+  
+--- Receiving TCP data
+
+TCP data reception is callback based - an application specified
+callback function is called when new data arrives. When the
+application has taken the data, it has to call the tcp_recved()
+function to indicate that TCP can advertise increase the receive
+window.
+
+- void tcp_recv(struct tcp_pcb *pcb,
+                err_t (* recv)(void *arg, struct tcp_pcb *tpcb,
+                               struct pbuf *p, err_t err))
+
+  Sets the callback function that will be called when new data
+  arrives. The callback function will be passed a NULL pbuf to
+  indicate that the remote host has closed the connection. If
+  there are no errors and the callback function is to return
+  ERR_OK, then it must free the pbuf. Otherwise, it must not
+  free the pbuf so that lwIP core code can store it.
+
+- void tcp_recved(struct tcp_pcb *pcb, u16_t len)
+
+  Must be called when the application has received the data. The len
+  argument indicates the length of the received data.
+
+
+--- Application polling
+
+When a connection is idle (i.e., no data is either transmitted or
+received), lwIP will repeatedly poll the application by calling a
+specified callback function. This can be used either as a watchdog
+timer for killing connections that have stayed idle for too long, or
+as a method of waiting for memory to become available. For instance,
+if a call to tcp_write() has failed because memory wasn't available,
+the application may use the polling functionality to call tcp_write()
+again when the connection has been idle for a while.
+
+- void tcp_poll(struct tcp_pcb *pcb, 
+                err_t (* poll)(void *arg, struct tcp_pcb *tpcb),
+                u8_t interval)
+
+  Specifies the polling interval and the callback function that should
+  be called to poll the application. The interval is specified in
+  number of TCP coarse grained timer shots, which typically occurs
+  twice a second. An interval of 10 means that the application would
+  be polled every 5 seconds.
+
+
+--- Closing and aborting connections
+
+- err_t tcp_close(struct tcp_pcb *pcb)
+
+  Closes the connection. The function may return ERR_MEM if no memory
+  was available for closing the connection. If so, the application
+  should wait and try again either by using the acknowledgment
+  callback or the polling functionality. If the close succeeds, the
+  function returns ERR_OK.
+
+  The pcb is deallocated by the TCP code after a call to tcp_close(). 
+
+- void tcp_abort(struct tcp_pcb *pcb)
+
+  Aborts the connection by sending a RST (reset) segment to the remote
+  host. The pcb is deallocated. This function never fails.
+
+  ATTENTION: When calling this from one of the TCP callbacks, make
+  sure you always return ERR_ABRT (and never return ERR_ABRT otherwise
+  or you will risk accessing deallocated memory or memory leaks!
+
+
+If a connection is aborted because of an error, the application is
+alerted of this event by the err callback. Errors that might abort a
+connection are when there is a shortage of memory. The callback
+function to be called is set using the tcp_err() function.
+
+- void tcp_err(struct tcp_pcb *pcb, void (* err)(void *arg,
+       err_t err))
+
+  The error callback function does not get the pcb passed to it as a
+  parameter since the pcb may already have been deallocated.
+
+
+--- UDP interface
+
+The UDP interface is similar to that of TCP, but due to the lower
+level of complexity of UDP, the interface is significantly simpler.
+
+- struct udp_pcb *udp_new(void)
+
+  Creates a new UDP pcb which can be used for UDP communication. The
+  pcb is not active until it has either been bound to a local address
+  or connected to a remote address.
+
+- void udp_remove(struct udp_pcb *pcb)
+
+  Removes and deallocates the pcb.  
+  
+- err_t udp_bind(struct udp_pcb *pcb, ip_addr_t *ipaddr,
+                 u16_t port)
+
+  Binds the pcb to a local address. The IP-address argument "ipaddr"
+  can be IP_ADDR_ANY to indicate that it should listen to any local IP
+  address. The function currently always return ERR_OK.
+
+- err_t udp_connect(struct udp_pcb *pcb, ip_addr_t *ipaddr,
+                    u16_t port)
+
+  Sets the remote end of the pcb. This function does not generate any
+  network traffic, but only set the remote address of the pcb.
+
+- err_t udp_disconnect(struct udp_pcb *pcb)
+
+  Remove the remote end of the pcb. This function does not generate
+  any network traffic, but only removes the remote address of the pcb.
+
+- err_t udp_send(struct udp_pcb *pcb, struct pbuf *p)
+
+  Sends the pbuf p. The pbuf is not deallocated.
+
+- void udp_recv(struct udp_pcb *pcb,
+                void (* recv)(void *arg, struct udp_pcb *upcb,
+                                         struct pbuf *p,
+                                         ip_addr_t *addr,
+                                         u16_t port),
+                              void *recv_arg)
+
+  Specifies a callback function that should be called when a UDP
+  datagram is received.
+  
+
+--- System initalization
+
+A truly complete and generic sequence for initializing the lwIP stack
+cannot be given because it depends on additional initializations for
+your runtime environment (e.g. timers).
+
+We can give you some idea on how to proceed when using the raw API.
+We assume a configuration using a single Ethernet netif and the
+UDP and TCP transport layers, IPv4 and the DHCP client.
+
+Call these functions in the order of appearance:
+
+- lwip_init()
+
+  Initialize the lwIP stack and all of its subsystems.
+
+- netif_add(struct netif *netif, const ip4_addr_t *ipaddr,
+            const ip4_addr_t *netmask, const ip4_addr_t *gw,
+            void *state, netif_init_fn init, netif_input_fn input)
+
+  Adds your network interface to the netif_list. Allocate a struct
+  netif and pass a pointer to this structure as the first argument.
+  Give pointers to cleared ip_addr structures when using DHCP,
+  or fill them with sane numbers otherwise. The state pointer may be NULL.
+
+  The init function pointer must point to a initialization function for
+  your Ethernet netif interface. The following code illustrates its use.
+  
+  err_t netif_if_init(struct netif *netif)
+  {
+    u8_t i;
+    
+    for (i = 0; i < ETHARP_HWADDR_LEN; i++) {
+      netif->hwaddr[i] = some_eth_addr[i];
+    }
+    init_my_eth_device();
+    return ERR_OK;
+  }
+  
+  For Ethernet drivers, the input function pointer must point to the lwIP
+  function ethernet_input() declared in "netif/etharp.h". Other drivers
+  must use ip_input() declared in "lwip/ip.h".
+  
+- netif_set_default(struct netif *netif)
+
+  Registers the default network interface.
+
+- netif_set_link_up(struct netif *netif)
+
+  This is the hardware link state; e.g. whether cable is plugged for wired
+  Ethernet interface. This function must be called even if you don't know
+  the current state. Having link up and link down events is optional but
+  DHCP and IPv6 discover benefit well from those events.
+
+- netif_set_up(struct netif *netif)
+
+  This is the administrative (= software) state of the netif, when the
+  netif is fully configured this function must be called.
+
+- dhcp_start(struct netif *netif)
+
+  Creates a new DHCP client for this interface on the first call.
+  
+  You can peek in the netif->dhcp struct for the actual DHCP status.
+
+- sys_check_timeouts()
+
+  When the system is running, you have to periodically call
+  sys_check_timeouts() which will handle all timers for all protocols in
+  the stack; add this to your main loop or equivalent.
+
+
+--- Optimalization hints
+
+The first thing you want to optimize is the lwip_standard_checksum()
+routine from src/core/inet.c. You can override this standard
+function with the #define LWIP_CHKSUM <your_checksum_routine>.
+
+There are C examples given in inet.c or you might want to
+craft an assembly function for this. RFC1071 is a good
+introduction to this subject.
+
+Other significant improvements can be made by supplying
+assembly or inline replacements for htons() and htonl()
+if you're using a little-endian architecture.
+#define LWIP_PLATFORM_BYTESWAP 1
+#define LWIP_PLATFORM_HTONS(x) <your_htons>
+#define LWIP_PLATFORM_HTONL(x) <your_htonl>
+
+Check your network interface driver if it reads at
+a higher speed than the maximum wire-speed. If the
+hardware isn't serviced frequently and fast enough
+buffer overflows are likely to occur.
+
+E.g. when using the cs8900 driver, call cs8900if_service(ethif)
+as frequently as possible. When using an RTOS let the cs8900 interrupt
+wake a high priority task that services your driver using a binary
+semaphore or event flag. Some drivers might allow additional tuning
+to match your application and network.
+
+For a production release it is recommended to set LWIP_STATS to 0.
+Note that speed performance isn't influenced much by simply setting
+high values to the memory options.
+
+For more optimization hints take a look at the lwIP wiki.
+
+--- Zero-copy MACs
+
+To achieve zero-copy on transmit, the data passed to the raw API must
+remain unchanged until sent. Because the send- (or write-)functions return
+when the packets have been enqueued for sending, data must be kept stable
+after that, too.
+
+This implies that PBUF_RAM/PBUF_POOL pbufs passed to raw-API send functions
+must *not* be reused by the application unless their ref-count is 1.
+
+For no-copy pbufs (PBUF_ROM/PBUF_REF), data must be kept unchanged, too,
+but the stack/driver will/must copy PBUF_REF'ed data when enqueueing, while
+PBUF_ROM-pbufs are just enqueued (as ROM-data is expected to never change).
+
+Also, data passed to tcp_write without the copy-flag must not be changed!
+
+Therefore, be careful which type of PBUF you use and if you copy TCP data
+or not!

ext/lwip/doc/savannah.txt

@@ -0,0 +1,120 @@
+Daily Use Guide for using Savannah for lwIP
+
+Table of Contents:
+
+1 - Obtaining lwIP from the Git repository
+2 - Committers/developers Git access using SSH
+3 - Merging a development branch to master branch
+4 - How to release lwIP
+
+
+
+1 Obtaining lwIP from the Git repository
+----------------------------------------
+
+To perform an anonymous Git clone of the master branch (this is where
+bug fixes and incremental enhancements occur), do this:
+ git clone git://git.savannah.nongnu.org/lwip.git
+
+Or, obtain a stable branch (updated with bug fixes only) as follows:
+ git clone --branch DEVEL-1_4_1 git://git.savannah.nongnu.org/lwip.git
+
+Or, obtain a specific (fixed) release as follows:
+ git clone --branch STABLE-1_4_1 git://git.savannah.nongnu.org/lwip.git
+
+
+2 Committers/developers Git access using SSH
+--------------------------------------------
+
+The Savannah server uses SSH (Secure Shell) protocol 2 authentication and encryption.
+As such, Git commits to the server occur through a SSH tunnel for project members.
+To create a SSH2 key pair in UNIX-like environments, do this:
+ ssh-keygen -t dsa
+
+Under Windows, a recommended SSH client is "PuTTY", freely available with good
+documentation and a graphic user interface. Use its key generator.
+
+Now paste the id_dsa.pub contents into your Savannah account public key list. Wait
+a while so that Savannah can update its configuration (This can take minutes).
+
+Try to login using SSH:
+ ssh -v your_login@git.sv.gnu.org
+
+If it tells you:
+ Linux vcs.savannah.gnu.org 2.6.32-5-xen-686 #1 SMP Wed Jun 17 17:10:03 UTC 2015 i686
+
+ Interactive shell login is not possible for security reasons.
+ VCS commands are allowed.
+ Last login: Tue May 15 23:10:12 2012 from 82.245.102.129
+ You tried to execute:
+ Sorry, you are not allowed to execute that command.
+ Shared connection to git.sv.gnu.org closed.
+
+then you could login; Savannah refuses to give you a shell - which is OK, as we
+are allowed to use SSH for Git only. Now, you should be able to do this:
+ git clone your_login@git.sv.gnu.org:/srv/git/lwip.git
+
+After which you can edit your local files with bug fixes or new features and
+commit them. Make sure you know what you are doing when using Git to make
+changes on the repository. If in doubt, ask on the lwip-members mailing list.
+
+(If SSH asks about authenticity of the host, you can check the key
+fingerprint against https://savannah.nongnu.org/git/?group=lwip
+
+
+3 - Merging a development branch to master branch
+-------------------------------------------------
+
+Merging is a straightforward process in Git. How to merge all changes in a
+development branch since our last merge from main:
+
+Checkout the master branch:
+ git checkout master
+
+Merge the development branch to master:
+ git merge your-development-branch
+
+Resolve any conflict.
+
+Commit the merge result.
+ git commit -a
+
+Push your commits:
+ git push
+
+
+4 How to release lwIP
+---------------------
+
+First, tag the release using Git: (I use release number 1.4.1 throughout
+this example).
+ git tag -a STABLE-1_4_1
+
+Share the tag reference by pushing it to remote:
+ git push origin STABLE-1_4_1
+
+Prepare the release:
+ cp -r lwip lwip-1.4.1
+ rm -rf lwip-1.4.1/.git lwip-1.4.1/.gitattributes
+
+Archive the current directory using tar, gzip'd, bzip2'd and zip'd.
+ tar czvf lwip-1.4.1.tar.gz lwip-1.4.1
+ tar cjvf lwip-1.4.1.tar.bz2 lwip-1.4.1
+ zip -r lwip-1.4.1.zip lwip-1.4.1
+
+Now, sign the archives with a detached GPG binary signature as follows:
+ gpg -b lwip-1.4.1.tar.gz
+ gpg -b lwip-1.4.1.tar.bz2
+ gpg -b lwip-1.4.1.zip
+
+Upload these files using anonymous FTP:
+ ncftp ftp://savannah.gnu.org/incoming/savannah/lwip
+ ncftp> mput *1.4.1.*
+
+Additionally, you may post a news item on Savannah, like this:
+
+A new 1.4.1 release is now available here:
+http://savannah.nongnu.org/files/?group=lwip&highlight=1.4.1
+
+You will have to submit this via the user News interface, then approve
+this via the Administrator News interface.

ext/lwip/doc/sys_arch.txt

@@ -0,0 +1,267 @@
+sys_arch interface for lwIP 0.6++
+
+Author: Adam Dunkels
+
+The operating system emulation layer provides a common interface
+between the lwIP code and the underlying operating system kernel. The
+general idea is that porting lwIP to new architectures requires only
+small changes to a few header files and a new sys_arch
+implementation. It is also possible to do a sys_arch implementation
+that does not rely on any underlying operating system.
+
+The sys_arch provides semaphores and mailboxes to lwIP. For the full
+lwIP functionality, multiple threads support can be implemented in the
+sys_arch, but this is not required for the basic lwIP
+functionality. Previous versions of lwIP required the sys_arch to
+implement timer scheduling as well but as of lwIP 0.5 this is
+implemented in a higher layer.
+
+In addition to the source file providing the functionality of sys_arch,
+the OS emulation layer must provide several header files defining
+macros used throughout lwip.  The files required and the macros they
+must define are listed below the sys_arch description.
+
+Semaphores can be either counting or binary - lwIP works with both
+kinds. Mailboxes are used for message passing and can be implemented
+either as a queue which allows multiple messages to be posted to a
+mailbox, or as a rendez-vous point where only one message can be
+posted at a time. lwIP works with both kinds, but the former type will
+be more efficient. A message in a mailbox is just a pointer, nothing
+more. 
+
+Semaphores are represented by the type "sys_sem_t" which is typedef'd
+in the sys_arch.h file. Mailboxes are equivalently represented by the
+type "sys_mbox_t". lwIP does not place any restrictions on how
+sys_sem_t or sys_mbox_t are represented internally.
+
+Since lwIP 1.4.0, semaphore and mailbox functions are prototyped in a way that
+allows both using pointers or actual OS structures to be used. This way, memory
+required for such types can be either allocated in place (globally or on the
+stack) or on the heap (allocated internally in the "*_new()" functions).
+
+The following functions must be implemented by the sys_arch:
+
+- void sys_init(void)
+
+  Is called to initialize the sys_arch layer.
+
+- err_t sys_sem_new(sys_sem_t *sem, u8_t count)
+
+  Creates a new semaphore. The semaphore is allocated to the memory that 'sem'
+  points to (which can be both a pointer or the actual OS structure).
+  The "count" argument specifies the initial state of the semaphore (which is
+  either 0 or 1).
+  If the semaphore has been created, ERR_OK should be returned. Returning any
+  other error will provide a hint what went wrong, but except for assertions,
+  no real error handling is implemented.
+
+- void sys_sem_free(sys_sem_t *sem)
+
+  Deallocates a semaphore.
+
+- void sys_sem_signal(sys_sem_t *sem)
+
+  Signals a semaphore.
+
+- u32_t sys_arch_sem_wait(sys_sem_t *sem, u32_t timeout)
+
+  Blocks the thread while waiting for the semaphore to be
+  signaled. If the "timeout" argument is non-zero, the thread should
+  only be blocked for the specified time (measured in
+  milliseconds). If the "timeout" argument is zero, the thread should be
+  blocked until the semaphore is signalled.
+
+  If the timeout argument is non-zero, the return value is the number of
+  milliseconds spent waiting for the semaphore to be signaled. If the
+  semaphore wasn't signaled within the specified time, the return value is
+  SYS_ARCH_TIMEOUT. If the thread didn't have to wait for the semaphore
+  (i.e., it was already signaled), the function may return zero.
+
+  Notice that lwIP implements a function with a similar name,
+  sys_sem_wait(), that uses the sys_arch_sem_wait() function.
+
+- int sys_sem_valid(sys_sem_t *sem)
+
+  Returns 1 if the semaphore is valid, 0 if it is not valid.
+  When using pointers, a simple way is to check the pointer for != NULL.
+  When directly using OS structures, implementing this may be more complex.
+  This may also be a define, in which case the function is not prototyped.
+
+- void sys_sem_set_invalid(sys_sem_t *sem)
+
+  Invalidate a semaphore so that sys_sem_valid() returns 0.
+  ATTENTION: This does NOT mean that the semaphore shall be deallocated:
+  sys_sem_free() is always called before calling this function!
+  This may also be a define, in which case the function is not prototyped.
+
+- err_t sys_mbox_new(sys_mbox_t *mbox, int size)
+
+  Creates an empty mailbox for maximum "size" elements. Elements stored
+  in mailboxes are pointers. You have to define macros "_MBOX_SIZE"
+  in your lwipopts.h, or ignore this parameter in your implementation
+  and use a default size.
+  If the mailbox has been created, ERR_OK should be returned. Returning any
+  other error will provide a hint what went wrong, but except for assertions,
+  no real error handling is implemented.
+
+- void sys_mbox_free(sys_mbox_t *mbox)
+
+  Deallocates a mailbox. If there are messages still present in the
+  mailbox when the mailbox is deallocated, it is an indication of a
+  programming error in lwIP and the developer should be notified.
+
+- void sys_mbox_post(sys_mbox_t *mbox, void *msg)
+
+  Posts the "msg" to the mailbox. This function have to block until
+  the "msg" is really posted.
+
+- err_t sys_mbox_trypost(sys_mbox_t *mbox, void *msg)
+
+  Try to post the "msg" to the mailbox. Returns ERR_MEM if this one
+  is full, else, ERR_OK if the "msg" is posted.
+
+- u32_t sys_arch_mbox_fetch(sys_mbox_t *mbox, void **msg, u32_t timeout)
+
+  Blocks the thread until a message arrives in the mailbox, but does
+  not block the thread longer than "timeout" milliseconds (similar to
+  the sys_arch_sem_wait() function). If "timeout" is 0, the thread should
+  be blocked until a message arrives. The "msg" argument is a result
+  parameter that is set by the function (i.e., by doing "*msg =
+  ptr"). The "msg" parameter maybe NULL to indicate that the message
+  should be dropped.
+
+  The return values are the same as for the sys_arch_sem_wait() function:
+  Number of milliseconds spent waiting or SYS_ARCH_TIMEOUT if there was a
+  timeout.
+
+  Note that a function with a similar name, sys_mbox_fetch(), is
+  implemented by lwIP. 
+
+- u32_t sys_arch_mbox_tryfetch(sys_mbox_t *mbox, void **msg)
+
+  This is similar to sys_arch_mbox_fetch, however if a message is not
+  present in the mailbox, it immediately returns with the code
+  SYS_MBOX_EMPTY. On success 0 is returned.
+
+  To allow for efficient implementations, this can be defined as a
+  function-like macro in sys_arch.h instead of a normal function. For
+  example, a naive implementation could be:
+    #define sys_arch_mbox_tryfetch(mbox,msg) \
+      sys_arch_mbox_fetch(mbox,msg,1)
+  although this would introduce unnecessary delays.
+
+- int sys_mbox_valid(sys_mbox_t *mbox)
+
+  Returns 1 if the mailbox is valid, 0 if it is not valid.
+  When using pointers, a simple way is to check the pointer for != NULL.
+  When directly using OS structures, implementing this may be more complex.
+  This may also be a define, in which case the function is not prototyped.
+
+- void sys_mbox_set_invalid(sys_mbox_t *mbox)
+
+  Invalidate a mailbox so that sys_mbox_valid() returns 0.
+  ATTENTION: This does NOT mean that the mailbox shall be deallocated:
+  sys_mbox_free() is always called before calling this function!
+  This may also be a define, in which case the function is not prototyped.
+
+If threads are supported by the underlying operating system and if
+such functionality is needed in lwIP, the following function will have
+to be implemented as well:
+
+- sys_thread_t sys_thread_new(char *name, void (* thread)(void *arg), void *arg, int stacksize, int prio)
+
+  Starts a new thread named "name" with priority "prio" that will begin its
+  execution in the function "thread()". The "arg" argument will be passed as an
+  argument to the thread() function. The stack size to used for this thread is
+  the "stacksize" parameter. The id of the new thread is returned. Both the id
+  and the priority are system dependent.
+
+- sys_prot_t sys_arch_protect(void)
+
+  This optional function does a "fast" critical region protection and returns
+  the previous protection level. This function is only called during very short
+  critical regions. An embedded system which supports ISR-based drivers might
+  want to implement this function by disabling interrupts. Task-based systems
+  might want to implement this by using a mutex or disabling tasking. This
+  function should support recursive calls from the same task or interrupt. In
+  other words, sys_arch_protect() could be called while already protected. In
+  that case the return value indicates that it is already protected.
+
+  sys_arch_protect() is only required if your port is supporting an operating
+  system.
+
+- void sys_arch_unprotect(sys_prot_t pval)
+
+  This optional function does a "fast" set of critical region protection to the
+  value specified by pval. See the documentation for sys_arch_protect() for
+  more information. This function is only required if your port is supporting
+  an operating system.
+
+For some configurations, you also need:
+
+- u32_t sys_now(void)
+
+  This optional function returns the current time in milliseconds (don't care
+  for wraparound, this is only used for time diffs).
+  Not implementing this function means you cannot use some modules (e.g. TCP
+  timestamps, internal timeouts for NO_SYS==1).
+
+
+Note:
+
+Be carefull with using mem_malloc() in sys_arch. When malloc() refers to
+mem_malloc() you can run into a circular function call problem. In mem.c
+mem_init() tries to allcate a semaphore using mem_malloc, which of course
+can't be performed when sys_arch uses mem_malloc.
+
+-------------------------------------------------------------------------------
+Additional files required for the "OS support" emulation layer:
+-------------------------------------------------------------------------------
+
+cc.h       - Architecture environment, some compiler specific, some
+             environment specific (probably should move env stuff 
+             to sys_arch.h.)
+
+  Typedefs for the types used by lwip -
+    u8_t, s8_t, u16_t, s16_t, u32_t, s32_t, mem_ptr_t
+
+  Compiler hints for packing lwip's structures -
+    PACK_STRUCT_FIELD(x)
+    PACK_STRUCT_STRUCT
+    PACK_STRUCT_BEGIN
+    PACK_STRUCT_END
+
+  Platform specific diagnostic output -
+    LWIP_PLATFORM_DIAG(x)    - non-fatal, print a message.
+    LWIP_PLATFORM_ASSERT(x)  - fatal, print message and abandon execution.
+    Portability defines for printf formatters:
+    U16_F, S16_F, X16_F, U32_F, S32_F, X32_F, SZT_F
+
+  "lightweight" synchronization mechanisms -
+    SYS_ARCH_DECL_PROTECT(x) - declare a protection state variable.
+    SYS_ARCH_PROTECT(x)      - enter protection mode.
+    SYS_ARCH_UNPROTECT(x)    - leave protection mode.
+
+  If the compiler does not provide memset() this file must include a
+  definition of it, or include a file which defines it.
+
+  This file must either include a system-local <errno.h> which defines
+  the standard *nix error codes, or it should #define LWIP_PROVIDE_ERRNO
+  to make lwip/arch.h define the codes which are used throughout.
+
+
+perf.h     - Architecture specific performance measurement.
+  Measurement calls made throughout lwip, these can be defined to nothing.
+    PERF_START               - start measuring something.
+    PERF_STOP(x)             - stop measuring something, and record the result.
+
+sys_arch.h - Tied to sys_arch.c
+
+  Arch dependent types for the following objects:
+    sys_sem_t, sys_mbox_t, sys_thread_t,
+  And, optionally:
+    sys_prot_t
+
+  Defines to set vars of sys_mbox_t and sys_sem_t to NULL.
+    SYS_MBOX_NULL NULL
+    SYS_SEM_NULL NULL

ext/lwip/src/FILES

@@ -0,0 +1,13 @@
+api/      - The code for the high-level wrapper API. Not needed if
+            you use the lowel-level call-back/raw API.
+
+core/     - The core of the TPC/IP stack; protocol implementations,
+            memory and buffer management, and the low-level raw API.
+
+include/  - lwIP include files.
+
+netif/    - Generic network interface device drivers are kept here,
+            as well as the ARP module.
+
+For more information on the various subdirectories, check the FILES
+file in each directory.

ext/lwip/src/Filelists.mk

@@ -0,0 +1,169 @@
+#
+# Copyright (c) 2001, 2002 Swedish Institute of Computer Science.
+# All rights reserved. 
+# 
+# Redistribution and use in source and binary forms, with or without modification, 
+# are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+#    this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+# 3. The name of the author may not be used to endorse or promote products
+#    derived from this software without specific prior written permission. 
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
+# WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+# MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
+# SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
+# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+# IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+# OF SUCH DAMAGE.
+#
+# This file is part of the lwIP TCP/IP stack.
+# 
+# Author: Adam Dunkels <adam@sics.se>
+#
+
+# COREFILES, CORE4FILES: The minimum set of files needed for lwIP.
+COREFILES=$(LWIPDIR)/core/init.c \
+	$(LWIPDIR)/core/def.c \
+	$(LWIPDIR)/core/dns.c \
+	$(LWIPDIR)/core/inet_chksum.c \
+	$(LWIPDIR)/core/ip.c \
+	$(LWIPDIR)/core/mem.c \
+	$(LWIPDIR)/core/memp.c \
+	$(LWIPDIR)/core/netif.c \
+	$(LWIPDIR)/core/pbuf.c \
+	$(LWIPDIR)/core/raw.c \
+	$(LWIPDIR)/core/stats.c \
+	$(LWIPDIR)/core/sys.c \
+	$(LWIPDIR)/core/tcp.c \
+	$(LWIPDIR)/core/tcp_in.c \
+	$(LWIPDIR)/core/tcp_out.c \
+	$(LWIPDIR)/core/timeouts.c \
+	$(LWIPDIR)/core/udp.c
+
+CORE4FILES=$(LWIPDIR)/core/ipv4/autoip.c \
+	$(LWIPDIR)/core/ipv4/dhcp.c \
+	$(LWIPDIR)/core/ipv4/etharp.c \
+	$(LWIPDIR)/core/ipv4/icmp.c \
+	$(LWIPDIR)/core/ipv4/igmp.c \
+	$(LWIPDIR)/core/ipv4/ip4_frag.c \
+	$(LWIPDIR)/core/ipv4/ip4.c \
+	$(LWIPDIR)/core/ipv4/ip4_addr.c
+
+CORE6FILES=$(LWIPDIR)/core/ipv6/dhcp6.c \
+	$(LWIPDIR)/core/ipv6/ethip6.c \
+	$(LWIPDIR)/core/ipv6/icmp6.c \
+	$(LWIPDIR)/core/ipv6/inet6.c \
+	$(LWIPDIR)/core/ipv6/ip6.c \
+	$(LWIPDIR)/core/ipv6/ip6_addr.c \
+	$(LWIPDIR)/core/ipv6/ip6_frag.c \
+	$(LWIPDIR)/core/ipv6/mld6.c \
+	$(LWIPDIR)/core/ipv6/nd6.c
+
+# APIFILES: The files which implement the sequential and socket APIs.
+APIFILES=$(LWIPDIR)/api/api_lib.c \
+	$(LWIPDIR)/api/api_msg.c \
+	$(LWIPDIR)/api/err.c \
+	$(LWIPDIR)/api/netbuf.c \
+	$(LWIPDIR)/api/netdb.c \
+	$(LWIPDIR)/api/netifapi.c \
+	$(LWIPDIR)/api/sockets.c \
+	$(LWIPDIR)/api/tcpip.c
+
+# NETIFFILES: Files implementing various generic network interface functions
+NETIFFILES=$(LWIPDIR)/netif/ethernet.c \
+	$(LWIPDIR)/netif/slipif.c
+
+# SIXLOWPAN: 6LoWPAN
+SIXLOWPAN=$(LWIPDIR)/netif/lowpan6.c \
+
+# PPPFILES: PPP
+PPPFILES=$(LWIPDIR)/netif/ppp/auth.c \
+	$(LWIPDIR)/netif/ppp/ccp.c \
+	$(LWIPDIR)/netif/ppp/chap-md5.c \
+	$(LWIPDIR)/netif/ppp/chap_ms.c \
+	$(LWIPDIR)/netif/ppp/chap-new.c \
+	$(LWIPDIR)/netif/ppp/demand.c \
+	$(LWIPDIR)/netif/ppp/eap.c \
+	$(LWIPDIR)/netif/ppp/ecp.c \
+	$(LWIPDIR)/netif/ppp/eui64.c \
+	$(LWIPDIR)/netif/ppp/fsm.c \
+	$(LWIPDIR)/netif/ppp/ipcp.c \
+	$(LWIPDIR)/netif/ppp/ipv6cp.c \
+	$(LWIPDIR)/netif/ppp/lcp.c \
+	$(LWIPDIR)/netif/ppp/magic.c \
+	$(LWIPDIR)/netif/ppp/mppe.c \
+	$(LWIPDIR)/netif/ppp/multilink.c \
+	$(LWIPDIR)/netif/ppp/ppp.c \
+	$(LWIPDIR)/netif/ppp/pppapi.c \
+	$(LWIPDIR)/netif/ppp/pppcrypt.c \
+	$(LWIPDIR)/netif/ppp/pppoe.c \
+	$(LWIPDIR)/netif/ppp/pppol2tp.c \
+	$(LWIPDIR)/netif/ppp/pppos.c \
+	$(LWIPDIR)/netif/ppp/upap.c \
+	$(LWIPDIR)/netif/ppp/utils.c \
+	$(LWIPDIR)/netif/ppp/vj.c \
+	$(LWIPDIR)/netif/ppp/polarssl/arc4.c \
+	$(LWIPDIR)/netif/ppp/polarssl/des.c \
+	$(LWIPDIR)/netif/ppp/polarssl/md4.c \
+	$(LWIPDIR)/netif/ppp/polarssl/md5.c \
+	$(LWIPDIR)/netif/ppp/polarssl/sha1.c
+
+# LWIPNOAPPSFILES: All LWIP files without apps
+LWIPNOAPPSFILES=$(COREFILES) \
+	$(CORE4FILES) \
+	$(CORE6FILES) \
+	$(APIFILES) \
+	$(NETIFFILES) \
+	$(PPPFILES) \
+	$(SIXLOWPAN)
+
+# SNMPFILES: SNMPv2c agent
+SNMPFILES=$(LWIPDIR)/apps/snmp/snmp_asn1.c \
+	$(LWIPDIR)/apps/snmp/snmp_core.c \
+	$(LWIPDIR)/apps/snmp/snmp_mib2.c \
+	$(LWIPDIR)/apps/snmp/snmp_mib2_icmp.c \
+	$(LWIPDIR)/apps/snmp/snmp_mib2_interfaces.c \
+	$(LWIPDIR)/apps/snmp/snmp_mib2_ip.c \
+	$(LWIPDIR)/apps/snmp/snmp_mib2_snmp.c \
+	$(LWIPDIR)/apps/snmp/snmp_mib2_system.c \
+	$(LWIPDIR)/apps/snmp/snmp_mib2_tcp.c \
+	$(LWIPDIR)/apps/snmp/snmp_mib2_udp.c \
+	$(LWIPDIR)/apps/snmp/snmp_msg.c \
+	$(LWIPDIR)/apps/snmp/snmpv3.c \
+	$(LWIPDIR)/apps/snmp/snmp_netconn.c \
+	$(LWIPDIR)/apps/snmp/snmp_pbuf_stream.c \
+	$(LWIPDIR)/apps/snmp/snmp_raw.c \
+	$(LWIPDIR)/apps/snmp/snmp_scalar.c \
+	$(LWIPDIR)/apps/snmp/snmp_table.c \
+	$(LWIPDIR)/apps/snmp/snmp_threadsync.c \
+	$(LWIPDIR)/apps/snmp/snmp_traps.c \
+	$(LWIPDIR)/apps/snmp/snmpv3_mbedtls.c \
+	$(LWIPDIR)/apps/snmp/snmpv3_dummy.c
+
+# HTTPDFILES: HTTP server
+HTTPDFILES=$(LWIPDIR)/apps/httpd/fs.c \
+	$(LWIPDIR)/apps/httpd/httpd.c
+
+# LWIPERFFILES: IPERF server
+LWIPERFFILES=$(LWIPDIR)/apps/lwiperf/lwiperf.c
+
+# SNTPFILES: SNTP client
+SNTPFILES=$(LWIPDIR)/apps/sntp/sntp.c
+
+# NETBIOSNSFILES: NetBIOS name server
+NETBIOSNSFILES=$(LWIPDIR)/apps/netbiosns/netbiosns.c
+
+# LWIPAPPFILES: All LWIP APPs
+LWIPAPPFILES=$(SNMPFILES) \
+	$(HTTPDFILES) \
+	$(LWIPERFFILES) \
+	$(SNTPFILES) \
+	$(NETBIOSNSFILES)

ext/lwip/src/api/api_lib.c

@@ -0,0 +1,993 @@
+/**
+ * @file
+ * Sequential API External module
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ */
+
+/**
+ * @defgroup netconn Netconn API
+ * @ingroup threadsafe_api
+ * Thread-safe, to be called from non-TCPIP threads only.
+ * TX/RX handling based on @ref netbuf (containing @ref pbuf)
+ * to avoid copying data around.
+ * 
+ * @defgroup netconn_common Common functions
+ * @ingroup netconn
+ * For use with TCP and UDP
+ * 
+ * @defgroup netconn_tcp TCP only
+ * @ingroup netconn
+ * TCP only functions
+ * 
+ * @defgroup netconn_udp UDP only
+ * @ingroup netconn
+ * UDP only functions
+ */
+
+/* This is the part of the API that is linked with
+   the application */
+
+#include "lwip/opt.h"
+
+#if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/api.h"
+#include "lwip/memp.h"
+
+#include "lwip/ip.h"
+#include "lwip/raw.h"
+#include "lwip/udp.h"
+#include "lwip/priv/api_msg.h"
+#include "lwip/priv/tcp_priv.h"
+#include "lwip/priv/tcpip_priv.h"
+
+#include <string.h>
+
+#define API_MSG_VAR_REF(name)               API_VAR_REF(name)
+#define API_MSG_VAR_DECLARE(name)           API_VAR_DECLARE(struct api_msg, name)
+#define API_MSG_VAR_ALLOC(name)             API_VAR_ALLOC(struct api_msg, MEMP_API_MSG, name, ERR_MEM)
+#define API_MSG_VAR_ALLOC_RETURN_NULL(name) API_VAR_ALLOC(struct api_msg, MEMP_API_MSG, name, NULL)
+#define API_MSG_VAR_FREE(name)              API_VAR_FREE(MEMP_API_MSG, name)
+
+static err_t netconn_close_shutdown(struct netconn *conn, u8_t how);
+
+/**
+ * Call the lower part of a netconn_* function
+ * This function is then running in the thread context
+ * of tcpip_thread and has exclusive access to lwIP core code.
+ *
+ * @param fn function to call
+ * @param apimsg a struct containing the function to call and its parameters
+ * @return ERR_OK if the function was called, another err_t if not
+ */
+static err_t
+netconn_apimsg(tcpip_callback_fn fn, struct api_msg *apimsg)
+{
+  err_t err;
+
+#ifdef LWIP_DEBUG
+  /* catch functions that don't set err */
+  apimsg->err = ERR_VAL;
+#endif /* LWIP_DEBUG */
+
+#if LWIP_NETCONN_SEM_PER_THREAD
+  apimsg->op_completed_sem = LWIP_NETCONN_THREAD_SEM_GET();
+#endif /* LWIP_NETCONN_SEM_PER_THREAD */
+
+  err = tcpip_send_msg_wait_sem(fn, apimsg, LWIP_API_MSG_SEM(apimsg));
+  if (err == ERR_OK) {
+    return apimsg->err;
+  }
+  return err;
+}
+
+/**
+ * Create a new netconn (of a specific type) that has a callback function.
+ * The corresponding pcb is also created.
+ *
+ * @param t the type of 'connection' to create (@see enum netconn_type)
+ * @param proto the IP protocol for RAW IP pcbs
+ * @param callback a function to call on status changes (RX available, TX'ed)
+ * @return a newly allocated struct netconn or
+ *         NULL on memory error
+ */
+struct netconn*
+netconn_new_with_proto_and_callback(enum netconn_type t, u8_t proto, netconn_callback callback)
+{
+  struct netconn *conn;
+  API_MSG_VAR_DECLARE(msg);
+  API_MSG_VAR_ALLOC_RETURN_NULL(msg);
+
+  conn = netconn_alloc(t, callback);
+  if (conn != NULL) {
+    err_t err;
+
+    API_MSG_VAR_REF(msg).msg.n.proto = proto;
+    API_MSG_VAR_REF(msg).conn = conn;
+    err = netconn_apimsg(lwip_netconn_do_newconn, &API_MSG_VAR_REF(msg));
+    if (err != ERR_OK) {
+      LWIP_ASSERT("freeing conn without freeing pcb", conn->pcb.tcp == NULL);
+      LWIP_ASSERT("conn has no recvmbox", sys_mbox_valid(&conn->recvmbox));
+#if LWIP_TCP
+      LWIP_ASSERT("conn->acceptmbox shouldn't exist", !sys_mbox_valid(&conn->acceptmbox));
+#endif /* LWIP_TCP */
+#if !LWIP_NETCONN_SEM_PER_THREAD
+      LWIP_ASSERT("conn has no op_completed", sys_sem_valid(&conn->op_completed));
+      sys_sem_free(&conn->op_completed);
+#endif /* !LWIP_NETCONN_SEM_PER_THREAD */
+      sys_mbox_free(&conn->recvmbox);
+      memp_free(MEMP_NETCONN, conn);
+      API_MSG_VAR_FREE(msg);
+      return NULL;
+    }
+  }
+  API_MSG_VAR_FREE(msg);
+  return conn;
+}
+
+/**
+ * @ingroup netconn_common
+ * Close a netconn 'connection' and free its resources.
+ * UDP and RAW connection are completely closed, TCP pcbs might still be in a waitstate
+ * after this returns.
+ *
+ * @param conn the netconn to delete
+ * @return ERR_OK if the connection was deleted
+ */
+err_t
+netconn_delete(struct netconn *conn)
+{
+  err_t err;
+  API_MSG_VAR_DECLARE(msg);
+
+  /* No ASSERT here because possible to get a (conn == NULL) if we got an accept error */
+  if (conn == NULL) {
+    return ERR_OK;
+  }
+
+  API_MSG_VAR_ALLOC(msg);
+  API_MSG_VAR_REF(msg).conn = conn;
+#if LWIP_SO_SNDTIMEO || LWIP_SO_LINGER
+  /* get the time we started, which is later compared to
+     sys_now() + conn->send_timeout */
+  API_MSG_VAR_REF(msg).msg.sd.time_started = sys_now();
+#else /* LWIP_SO_SNDTIMEO || LWIP_SO_LINGER */
+#if LWIP_TCP
+  API_MSG_VAR_REF(msg).msg.sd.polls_left =
+    ((LWIP_TCP_CLOSE_TIMEOUT_MS_DEFAULT + TCP_SLOW_INTERVAL - 1) / TCP_SLOW_INTERVAL) + 1;
+#endif /* LWIP_TCP */
+#endif /* LWIP_SO_SNDTIMEO || LWIP_SO_LINGER */
+  err = netconn_apimsg(lwip_netconn_do_delconn, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+
+  if (err != ERR_OK) {
+    return err;
+  }
+
+  netconn_free(conn);
+
+  return ERR_OK;
+}
+
+/**
+ * Get the local or remote IP address and port of a netconn.
+ * For RAW netconns, this returns the protocol instead of a port!
+ *
+ * @param conn the netconn to query
+ * @param addr a pointer to which to save the IP address
+ * @param port a pointer to which to save the port (or protocol for RAW)
+ * @param local 1 to get the local IP address, 0 to get the remote one
+ * @return ERR_CONN for invalid connections
+ *         ERR_OK if the information was retrieved
+ */
+err_t
+netconn_getaddr(struct netconn *conn, ip_addr_t *addr, u16_t *port, u8_t local)
+{
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+
+  LWIP_ERROR("netconn_getaddr: invalid conn", (conn != NULL), return ERR_ARG;);
+  LWIP_ERROR("netconn_getaddr: invalid addr", (addr != NULL), return ERR_ARG;);
+  LWIP_ERROR("netconn_getaddr: invalid port", (port != NULL), return ERR_ARG;);
+
+  API_MSG_VAR_ALLOC(msg);
+  API_MSG_VAR_REF(msg).conn = conn;
+  API_MSG_VAR_REF(msg).msg.ad.local = local;
+#if LWIP_MPU_COMPATIBLE
+  err = netconn_apimsg(lwip_netconn_do_getaddr, &API_MSG_VAR_REF(msg));
+  *addr = msg->msg.ad.ipaddr;
+  *port = msg->msg.ad.port;
+#else /* LWIP_MPU_COMPATIBLE */
+  msg.msg.ad.ipaddr = addr;
+  msg.msg.ad.port = port;
+  err = netconn_apimsg(lwip_netconn_do_getaddr, &msg);
+#endif /* LWIP_MPU_COMPATIBLE */
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+}
+
+/**
+ * @ingroup netconn_common
+ * Bind a netconn to a specific local IP address and port.
+ * Binding one netconn twice might not always be checked correctly!
+ *
+ * @param conn the netconn to bind
+ * @param addr the local IP address to bind the netconn to (use IP_ADDR_ANY
+ *             to bind to all addresses)
+ * @param port the local port to bind the netconn to (not used for RAW)
+ * @return ERR_OK if bound, any other err_t on failure
+ */
+err_t
+netconn_bind(struct netconn *conn, const ip_addr_t *addr, u16_t port)
+{
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+  
+  LWIP_ERROR("netconn_bind: invalid conn", (conn != NULL), return ERR_ARG;);
+
+  /* Don't propagate NULL pointer (IP_ADDR_ANY alias) to subsequent functions */
+  if (addr == NULL) {
+    addr = IP_ADDR_ANY;
+  }
+
+  API_MSG_VAR_ALLOC(msg);
+  API_MSG_VAR_REF(msg).conn = conn;
+  API_MSG_VAR_REF(msg).msg.bc.ipaddr = API_MSG_VAR_REF(addr);
+  API_MSG_VAR_REF(msg).msg.bc.port = port;
+  err = netconn_apimsg(lwip_netconn_do_bind, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+}
+
+/**
+ * @ingroup netconn_common
+ * Connect a netconn to a specific remote IP address and port.
+ *
+ * @param conn the netconn to connect
+ * @param addr the remote IP address to connect to
+ * @param port the remote port to connect to (no used for RAW)
+ * @return ERR_OK if connected, return value of tcp_/udp_/raw_connect otherwise
+ */
+err_t
+netconn_connect(struct netconn *conn, const ip_addr_t *addr, u16_t port)
+{
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+
+  LWIP_ERROR("netconn_connect: invalid conn", (conn != NULL), return ERR_ARG;);
+
+  /* Don't propagate NULL pointer (IP_ADDR_ANY alias) to subsequent functions */
+  if (addr == NULL) {
+    addr = IP_ADDR_ANY;
+  }
+
+  API_MSG_VAR_ALLOC(msg);
+  API_MSG_VAR_REF(msg).conn = conn;
+  API_MSG_VAR_REF(msg).msg.bc.ipaddr = API_MSG_VAR_REF(addr);
+  API_MSG_VAR_REF(msg).msg.bc.port = port;
+  err = netconn_apimsg(lwip_netconn_do_connect, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+}
+
+/**
+ * @ingroup netconn_udp
+ * Disconnect a netconn from its current peer (only valid for UDP netconns).
+ *
+ * @param conn the netconn to disconnect
+ * @return @todo: return value is not set here...
+ */
+err_t
+netconn_disconnect(struct netconn *conn)
+{
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+
+  LWIP_ERROR("netconn_disconnect: invalid conn", (conn != NULL), return ERR_ARG;);
+
+  API_MSG_VAR_ALLOC(msg);
+  API_MSG_VAR_REF(msg).conn = conn;
+  err = netconn_apimsg(lwip_netconn_do_disconnect, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+}
+
+/**
+ * @ingroup netconn_tcp
+ * Set a TCP netconn into listen mode
+ *
+ * @param conn the tcp netconn to set to listen mode
+ * @param backlog the listen backlog, only used if TCP_LISTEN_BACKLOG==1
+ * @return ERR_OK if the netconn was set to listen (UDP and RAW netconns
+ *         don't return any error (yet?))
+ */
+err_t
+netconn_listen_with_backlog(struct netconn *conn, u8_t backlog)
+{
+#if LWIP_TCP
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+
+  /* This does no harm. If TCP_LISTEN_BACKLOG is off, backlog is unused. */
+  LWIP_UNUSED_ARG(backlog);
+
+  LWIP_ERROR("netconn_listen: invalid conn", (conn != NULL), return ERR_ARG;);
+
+  API_MSG_VAR_ALLOC(msg);
+  API_MSG_VAR_REF(msg).conn = conn;
+#if TCP_LISTEN_BACKLOG
+  API_MSG_VAR_REF(msg).msg.lb.backlog = backlog;
+#endif /* TCP_LISTEN_BACKLOG */
+  err = netconn_apimsg(lwip_netconn_do_listen, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+#else /* LWIP_TCP */
+  LWIP_UNUSED_ARG(conn);
+  LWIP_UNUSED_ARG(backlog);
+  return ERR_ARG;
+#endif /* LWIP_TCP */
+}
+
+/**
+ * @ingroup netconn_tcp
+ * Accept a new connection on a TCP listening netconn.
+ *
+ * @param conn the TCP listen netconn
+ * @param new_conn pointer where the new connection is stored
+ * @return ERR_OK if a new connection has been received or an error
+ *                code otherwise
+ */
+err_t
+netconn_accept(struct netconn *conn, struct netconn **new_conn)
+{
+#if LWIP_TCP
+  void *accept_ptr;
+  struct netconn *newconn;
+  err_t err;
+#if TCP_LISTEN_BACKLOG
+  API_MSG_VAR_DECLARE(msg);
+#endif /* TCP_LISTEN_BACKLOG */
+
+  LWIP_ERROR("netconn_accept: invalid pointer",    (new_conn != NULL),                  return ERR_ARG;);
+  *new_conn = NULL;
+  LWIP_ERROR("netconn_accept: invalid conn",       (conn != NULL),                      return ERR_ARG;);
+
+  err = conn->last_err;
+  if (ERR_IS_FATAL(err)) {
+    /* don't recv on fatal errors: this might block the application task
+       waiting on acceptmbox forever! */
+    return err;
+  }
+  if (!sys_mbox_valid(&conn->acceptmbox)) {
+    return ERR_CLSD;
+  }
+
+#if TCP_LISTEN_BACKLOG
+  API_MSG_VAR_ALLOC(msg);
+#endif /* TCP_LISTEN_BACKLOG */
+
+#if LWIP_SO_RCVTIMEO
+  if (sys_arch_mbox_fetch(&conn->acceptmbox, &accept_ptr, conn->recv_timeout) == SYS_ARCH_TIMEOUT) {
+#if TCP_LISTEN_BACKLOG
+    API_MSG_VAR_FREE(msg);
+#endif /* TCP_LISTEN_BACKLOG */
+    return ERR_TIMEOUT;
+  }
+#else
+  sys_arch_mbox_fetch(&conn->acceptmbox, &accept_ptr, 0);
+#endif /* LWIP_SO_RCVTIMEO*/
+  newconn = (struct netconn *)accept_ptr;
+  /* Register event with callback */
+  API_EVENT(conn, NETCONN_EVT_RCVMINUS, 0);
+
+  if (accept_ptr == &netconn_aborted) {
+    /* a connection has been aborted: out of pcbs or out of netconns during accept */
+    /* @todo: set netconn error, but this would be fatal and thus block further accepts */
+#if TCP_LISTEN_BACKLOG
+    API_MSG_VAR_FREE(msg);
+#endif /* TCP_LISTEN_BACKLOG */
+    return ERR_ABRT;
+  }
+  if (newconn == NULL) {
+    /* connection has been aborted */
+    /* in this special case, we set the netconn error from application thread, as
+       on a ready-to-accept listening netconn, there should not be anything running
+       in tcpip_thread */
+    NETCONN_SET_SAFE_ERR(conn, ERR_CLSD);
+#if TCP_LISTEN_BACKLOG
+    API_MSG_VAR_FREE(msg);
+#endif /* TCP_LISTEN_BACKLOG */
+    return ERR_CLSD;
+  }
+#if TCP_LISTEN_BACKLOG
+  /* Let the stack know that we have accepted the connection. */
+  API_MSG_VAR_REF(msg).conn = newconn;
+  /* don't care for the return value of lwip_netconn_do_recv */
+  netconn_apimsg(lwip_netconn_do_accepted, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+#endif /* TCP_LISTEN_BACKLOG */
+
+  *new_conn = newconn;
+  /* don't set conn->last_err: it's only ERR_OK, anyway */
+  return ERR_OK;
+#else /* LWIP_TCP */
+  LWIP_UNUSED_ARG(conn);
+  LWIP_UNUSED_ARG(new_conn);
+  return ERR_ARG;
+#endif /* LWIP_TCP */
+}
+
+/**
+ * @ingroup netconn_common
+ * Receive data: actual implementation that doesn't care whether pbuf or netbuf
+ * is received
+ *
+ * @param conn the netconn from which to receive data
+ * @param new_buf pointer where a new pbuf/netbuf is stored when received data
+ * @return ERR_OK if data has been received, an error code otherwise (timeout,
+ *                memory error or another error)
+ */
+static err_t
+netconn_recv_data(struct netconn *conn, void **new_buf)
+{
+  void *buf = NULL;
+  u16_t len;
+  err_t err;
+#if LWIP_TCP
+  API_MSG_VAR_DECLARE(msg);
+#if LWIP_MPU_COMPATIBLE
+  msg = NULL;
+#endif
+#endif /* LWIP_TCP */
+
+  LWIP_ERROR("netconn_recv: invalid pointer", (new_buf != NULL), return ERR_ARG;);
+  *new_buf = NULL;
+  LWIP_ERROR("netconn_recv: invalid conn",    (conn != NULL),    return ERR_ARG;);
+#if LWIP_TCP
+#if (LWIP_UDP || LWIP_RAW)
+  if (NETCONNTYPE_GROUP(conn->type) == NETCONN_TCP)
+#endif /* (LWIP_UDP || LWIP_RAW) */
+  {
+    if (!sys_mbox_valid(&conn->recvmbox)) {
+      /* This happens when calling this function after receiving FIN */
+      return sys_mbox_valid(&conn->acceptmbox) ? ERR_CONN : ERR_CLSD;
+    }
+  }
+#endif /* LWIP_TCP */
+  LWIP_ERROR("netconn_recv: invalid recvmbox", sys_mbox_valid(&conn->recvmbox), return ERR_CONN;);
+
+  err = conn->last_err;
+  if (ERR_IS_FATAL(err)) {
+    /* don't recv on fatal errors: this might block the application task
+       waiting on recvmbox forever! */
+    /* @todo: this does not allow us to fetch data that has been put into recvmbox
+       before the fatal error occurred - is that a problem? */
+    return err;
+  }
+#if LWIP_TCP
+#if (LWIP_UDP || LWIP_RAW)
+  if (NETCONNTYPE_GROUP(conn->type) == NETCONN_TCP)
+#endif /* (LWIP_UDP || LWIP_RAW) */
+  {
+    API_MSG_VAR_ALLOC(msg);
+  }
+#endif /* LWIP_TCP */
+
+#if LWIP_SO_RCVTIMEO
+  if (sys_arch_mbox_fetch(&conn->recvmbox, &buf, conn->recv_timeout) == SYS_ARCH_TIMEOUT) {
+#if LWIP_TCP
+#if (LWIP_UDP || LWIP_RAW)
+    if (NETCONNTYPE_GROUP(conn->type) == NETCONN_TCP)
+#endif /* (LWIP_UDP || LWIP_RAW) */
+    {
+      API_MSG_VAR_FREE(msg);
+    }
+#endif /* LWIP_TCP */
+    return ERR_TIMEOUT;
+  }
+#else
+  sys_arch_mbox_fetch(&conn->recvmbox, &buf, 0);
+#endif /* LWIP_SO_RCVTIMEO*/
+
+#if LWIP_TCP
+#if (LWIP_UDP || LWIP_RAW)
+  if (NETCONNTYPE_GROUP(conn->type) == NETCONN_TCP)
+#endif /* (LWIP_UDP || LWIP_RAW) */
+  {
+    /* Let the stack know that we have taken the data. */
+    /* @todo: Speedup: Don't block and wait for the answer here
+       (to prevent multiple thread-switches). */
+    API_MSG_VAR_REF(msg).conn = conn;
+    if (buf != NULL) {
+      API_MSG_VAR_REF(msg).msg.r.len = ((struct pbuf *)buf)->tot_len;
+    } else {
+      API_MSG_VAR_REF(msg).msg.r.len = 1;
+    }
+
+    /* don't care for the return value of lwip_netconn_do_recv */
+    netconn_apimsg(lwip_netconn_do_recv, &API_MSG_VAR_REF(msg));
+    API_MSG_VAR_FREE(msg);
+
+    /* If we are closed, we indicate that we no longer wish to use the socket */
+    if (buf == NULL) {
+      API_EVENT(conn, NETCONN_EVT_RCVMINUS, 0);
+      /* RX side is closed, so deallocate the recvmbox */
+      netconn_close_shutdown(conn, NETCONN_SHUT_RD);
+      /* Don' store ERR_CLSD as conn->err since we are only half-closed */
+      return ERR_CLSD;
+    }
+    len = ((struct pbuf *)buf)->tot_len;
+  }
+#endif /* LWIP_TCP */
+#if LWIP_TCP && (LWIP_UDP || LWIP_RAW)
+  else
+#endif /* LWIP_TCP && (LWIP_UDP || LWIP_RAW) */
+#if (LWIP_UDP || LWIP_RAW)
+  {
+    LWIP_ASSERT("buf != NULL", buf != NULL);
+    len = netbuf_len((struct netbuf *)buf);
+  }
+#endif /* (LWIP_UDP || LWIP_RAW) */
+
+#if LWIP_SO_RCVBUF
+  SYS_ARCH_DEC(conn->recv_avail, len);
+#endif /* LWIP_SO_RCVBUF */
+  /* Register event with callback */
+  API_EVENT(conn, NETCONN_EVT_RCVMINUS, len);
+
+  LWIP_DEBUGF(API_LIB_DEBUG, ("netconn_recv_data: received %p, len=%"U16_F"\n", buf, len));
+
+  *new_buf = buf;
+  /* don't set conn->last_err: it's only ERR_OK, anyway */
+  return ERR_OK;
+}
+
+/**
+ * @ingroup netconn_tcp
+ * Receive data (in form of a pbuf) from a TCP netconn
+ *
+ * @param conn the netconn from which to receive data
+ * @param new_buf pointer where a new pbuf is stored when received data
+ * @return ERR_OK if data has been received, an error code otherwise (timeout,
+ *                memory error or another error)
+ *         ERR_ARG if conn is not a TCP netconn
+ */
+err_t
+netconn_recv_tcp_pbuf(struct netconn *conn, struct pbuf **new_buf)
+{
+  LWIP_ERROR("netconn_recv: invalid conn", (conn != NULL) &&
+             NETCONNTYPE_GROUP(netconn_type(conn)) == NETCONN_TCP, return ERR_ARG;);
+
+  return netconn_recv_data(conn, (void **)new_buf);
+}
+
+/**
+ * @ingroup netconn_common
+ * Receive data (in form of a netbuf containing a packet buffer) from a netconn
+ *
+ * @param conn the netconn from which to receive data
+ * @param new_buf pointer where a new netbuf is stored when received data
+ * @return ERR_OK if data has been received, an error code otherwise (timeout,
+ *                memory error or another error)
+ */
+err_t
+netconn_recv(struct netconn *conn, struct netbuf **new_buf)
+{
+#if LWIP_TCP
+  struct netbuf *buf = NULL;
+  err_t err;
+#endif /* LWIP_TCP */
+
+  LWIP_ERROR("netconn_recv: invalid pointer", (new_buf != NULL), return ERR_ARG;);
+  *new_buf = NULL;
+  LWIP_ERROR("netconn_recv: invalid conn",    (conn != NULL),    return ERR_ARG;);
+
+#if LWIP_TCP
+#if (LWIP_UDP || LWIP_RAW)
+  if (NETCONNTYPE_GROUP(conn->type) == NETCONN_TCP)
+#endif /* (LWIP_UDP || LWIP_RAW) */
+  {
+    struct pbuf *p = NULL;
+    /* This is not a listening netconn, since recvmbox is set */
+
+    buf = (struct netbuf *)memp_malloc(MEMP_NETBUF);
+    if (buf == NULL) {
+      return ERR_MEM;
+    }
+
+    err = netconn_recv_data(conn, (void **)&p);
+    if (err != ERR_OK) {
+      memp_free(MEMP_NETBUF, buf);
+      return err;
+    }
+    LWIP_ASSERT("p != NULL", p != NULL);
+
+    buf->p = p;
+    buf->ptr = p;
+    buf->port = 0;
+    ip_addr_set_zero(&buf->addr);
+    *new_buf = buf;
+    /* don't set conn->last_err: it's only ERR_OK, anyway */
+    return ERR_OK;
+  }
+#endif /* LWIP_TCP */
+#if LWIP_TCP && (LWIP_UDP || LWIP_RAW)
+  else
+#endif /* LWIP_TCP && (LWIP_UDP || LWIP_RAW) */
+  {
+#if (LWIP_UDP || LWIP_RAW)
+    return netconn_recv_data(conn, (void **)new_buf);
+#endif /* (LWIP_UDP || LWIP_RAW) */
+  }
+}
+
+/**
+ * @ingroup netconn_udp
+ * Send data (in form of a netbuf) to a specific remote IP address and port.
+ * Only to be used for UDP and RAW netconns (not TCP).
+ *
+ * @param conn the netconn over which to send data
+ * @param buf a netbuf containing the data to send
+ * @param addr the remote IP address to which to send the data
+ * @param port the remote port to which to send the data
+ * @return ERR_OK if data was sent, any other err_t on error
+ */
+err_t
+netconn_sendto(struct netconn *conn, struct netbuf *buf, const ip_addr_t *addr, u16_t port)
+{
+  if (buf != NULL) {
+    ip_addr_set(&buf->addr, addr);
+    buf->port = port;
+    return netconn_send(conn, buf);
+  }
+  return ERR_VAL;
+}
+
+/**
+ * @ingroup netconn_udp
+ * Send data over a UDP or RAW netconn (that is already connected).
+ *
+ * @param conn the UDP or RAW netconn over which to send data
+ * @param buf a netbuf containing the data to send
+ * @return ERR_OK if data was sent, any other err_t on error
+ */
+err_t
+netconn_send(struct netconn *conn, struct netbuf *buf)
+{
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+
+  LWIP_ERROR("netconn_send: invalid conn",  (conn != NULL), return ERR_ARG;);
+
+  LWIP_DEBUGF(API_LIB_DEBUG, ("netconn_send: sending %"U16_F" bytes\n", buf->p->tot_len));
+  API_MSG_VAR_ALLOC(msg);
+  API_MSG_VAR_REF(msg).conn = conn;
+  API_MSG_VAR_REF(msg).msg.b = buf;
+  err = netconn_apimsg(lwip_netconn_do_send, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+}
+
+/**
+ * @ingroup netconn_tcp
+ * Send data over a TCP netconn.
+ *
+ * @param conn the TCP netconn over which to send data
+ * @param dataptr pointer to the application buffer that contains the data to send
+ * @param size size of the application data to send
+ * @param apiflags combination of following flags :
+ * - NETCONN_COPY: data will be copied into memory belonging to the stack
+ * - NETCONN_MORE: for TCP connection, PSH flag will be set on last segment sent
+ * - NETCONN_DONTBLOCK: only write the data if all data can be written at once
+ * @param bytes_written pointer to a location that receives the number of written bytes
+ * @return ERR_OK if data was sent, any other err_t on error
+ */
+err_t
+netconn_write_partly(struct netconn *conn, const void *dataptr, size_t size,
+                     u8_t apiflags, size_t *bytes_written)
+{
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+  u8_t dontblock;
+
+  LWIP_ERROR("netconn_write: invalid conn",  (conn != NULL), return ERR_ARG;);
+  LWIP_ERROR("netconn_write: invalid conn->type",  (NETCONNTYPE_GROUP(conn->type)== NETCONN_TCP), return ERR_VAL;);
+  if (size == 0) {
+    return ERR_OK;
+  }
+  dontblock = netconn_is_nonblocking(conn) || (apiflags & NETCONN_DONTBLOCK);
+  if (dontblock && !bytes_written) {
+    /* This implies netconn_write() cannot be used for non-blocking send, since
+       it has no way to return the number of bytes written. */
+    return ERR_VAL;
+  }
+
+  API_MSG_VAR_ALLOC(msg);
+  /* non-blocking write sends as much  */
+  API_MSG_VAR_REF(msg).conn = conn;
+  API_MSG_VAR_REF(msg).msg.w.dataptr = dataptr;
+  API_MSG_VAR_REF(msg).msg.w.apiflags = apiflags;
+  API_MSG_VAR_REF(msg).msg.w.len = size;
+#if LWIP_SO_SNDTIMEO
+  if (conn->send_timeout != 0) {
+    /* get the time we started, which is later compared to
+        sys_now() + conn->send_timeout */
+    API_MSG_VAR_REF(msg).msg.w.time_started = sys_now();
+  } else {
+    API_MSG_VAR_REF(msg).msg.w.time_started = 0;
+  }
+#endif /* LWIP_SO_SNDTIMEO */
+
+  /* For locking the core: this _can_ be delayed on low memory/low send buffer,
+     but if it is, this is done inside api_msg.c:do_write(), so we can use the
+     non-blocking version here. */
+  err = netconn_apimsg(lwip_netconn_do_write, &API_MSG_VAR_REF(msg));
+  if ((err == ERR_OK) && (bytes_written != NULL)) {
+    if (dontblock
+#if LWIP_SO_SNDTIMEO
+        || (conn->send_timeout != 0)
+#endif /* LWIP_SO_SNDTIMEO */
+       ) {
+      /* nonblocking write: maybe the data has been sent partly */
+      *bytes_written = API_MSG_VAR_REF(msg).msg.w.len;
+    } else {
+      /* blocking call succeeded: all data has been sent if it */
+      *bytes_written = size;
+    }
+  }
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+}
+
+/**
+ * @ingroup netconn_tcp
+ * Close or shutdown a TCP netconn (doesn't delete it).
+ *
+ * @param conn the TCP netconn to close or shutdown
+ * @param how fully close or only shutdown one side?
+ * @return ERR_OK if the netconn was closed, any other err_t on error
+ */
+static err_t
+netconn_close_shutdown(struct netconn *conn, u8_t how)
+{
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+  LWIP_UNUSED_ARG(how);
+
+  LWIP_ERROR("netconn_close: invalid conn",  (conn != NULL), return ERR_ARG;);
+
+  API_MSG_VAR_ALLOC(msg);
+  API_MSG_VAR_REF(msg).conn = conn;
+#if LWIP_TCP
+  /* shutting down both ends is the same as closing */
+  API_MSG_VAR_REF(msg).msg.sd.shut = how;
+#if LWIP_SO_SNDTIMEO || LWIP_SO_LINGER
+  /* get the time we started, which is later compared to
+     sys_now() + conn->send_timeout */
+  API_MSG_VAR_REF(msg).msg.sd.time_started = sys_now();
+#else /* LWIP_SO_SNDTIMEO || LWIP_SO_LINGER */
+  API_MSG_VAR_REF(msg).msg.sd.polls_left =
+    ((LWIP_TCP_CLOSE_TIMEOUT_MS_DEFAULT + TCP_SLOW_INTERVAL - 1) / TCP_SLOW_INTERVAL) + 1;
+#endif /* LWIP_SO_SNDTIMEO || LWIP_SO_LINGER */
+#endif /* LWIP_TCP */
+  err = netconn_apimsg(lwip_netconn_do_close, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+}
+
+/**
+ * @ingroup netconn_tcp
+ * Close a TCP netconn (doesn't delete it).
+ *
+ * @param conn the TCP netconn to close
+ * @return ERR_OK if the netconn was closed, any other err_t on error
+ */
+err_t
+netconn_close(struct netconn *conn)
+{
+  /* shutting down both ends is the same as closing */
+  return netconn_close_shutdown(conn, NETCONN_SHUT_RDWR);
+}
+
+/**
+ * @ingroup netconn_tcp
+ * Shut down one or both sides of a TCP netconn (doesn't delete it).
+ *
+ * @param conn the TCP netconn to shut down
+ * @param shut_rx shut down the RX side (no more read possible after this)
+ * @param shut_tx shut down the TX side (no more write possible after this)
+ * @return ERR_OK if the netconn was closed, any other err_t on error
+ */
+err_t
+netconn_shutdown(struct netconn *conn, u8_t shut_rx, u8_t shut_tx)
+{
+  return netconn_close_shutdown(conn, (shut_rx ? NETCONN_SHUT_RD : 0) | (shut_tx ? NETCONN_SHUT_WR : 0));
+}
+
+#if LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD)
+/**
+ * @ingroup netconn_udp
+ * Join multicast groups for UDP netconns.
+ *
+ * @param conn the UDP netconn for which to change multicast addresses
+ * @param multiaddr IP address of the multicast group to join or leave
+ * @param netif_addr the IP address of the network interface on which to send
+ *                  the igmp message
+ * @param join_or_leave flag whether to send a join- or leave-message
+ * @return ERR_OK if the action was taken, any err_t on error
+ */
+err_t
+netconn_join_leave_group(struct netconn *conn,
+                         const ip_addr_t *multiaddr,
+                         const ip_addr_t *netif_addr,
+                         enum netconn_igmp join_or_leave)
+{
+  API_MSG_VAR_DECLARE(msg);
+  err_t err;
+
+  LWIP_ERROR("netconn_join_leave_group: invalid conn",  (conn != NULL), return ERR_ARG;);
+
+  API_MSG_VAR_ALLOC(msg);
+
+  /* Don't propagate NULL pointer (IP_ADDR_ANY alias) to subsequent functions */
+  if (multiaddr == NULL) {
+    multiaddr = IP_ADDR_ANY;
+  }
+  if (netif_addr == NULL) {
+    netif_addr = IP_ADDR_ANY;
+  }
+
+  API_MSG_VAR_REF(msg).conn = conn;
+  API_MSG_VAR_REF(msg).msg.jl.multiaddr = API_MSG_VAR_REF(multiaddr);
+  API_MSG_VAR_REF(msg).msg.jl.netif_addr = API_MSG_VAR_REF(netif_addr);
+  API_MSG_VAR_REF(msg).msg.jl.join_or_leave = join_or_leave;
+  err = netconn_apimsg(lwip_netconn_do_join_leave_group, &API_MSG_VAR_REF(msg));
+  API_MSG_VAR_FREE(msg);
+
+  return err;
+}
+#endif /* LWIP_IGMP || (LWIP_IPV6 && LWIP_IPV6_MLD) */
+
+#if LWIP_DNS
+/**
+ * @ingroup netconn_common
+ * Execute a DNS query, only one IP address is returned
+ *
+ * @param name a string representation of the DNS host name to query
+ * @param addr a preallocated ip_addr_t where to store the resolved IP address
+ * @param dns_addrtype IP address type (IPv4 / IPv6)
+ * @return ERR_OK: resolving succeeded
+ *         ERR_MEM: memory error, try again later
+ *         ERR_ARG: dns client not initialized or invalid hostname
+ *         ERR_VAL: dns server response was invalid
+ */
+#if LWIP_IPV4 && LWIP_IPV6
+err_t
+netconn_gethostbyname_addrtype(const char *name, ip_addr_t *addr, u8_t dns_addrtype)
+#else
+err_t
+netconn_gethostbyname(const char *name, ip_addr_t *addr)
+#endif
+{
+  API_VAR_DECLARE(struct dns_api_msg, msg);
+#if !LWIP_MPU_COMPATIBLE
+  sys_sem_t sem;
+#endif /* LWIP_MPU_COMPATIBLE */
+  err_t err;
+
+  LWIP_ERROR("netconn_gethostbyname: invalid name", (name != NULL), return ERR_ARG;);
+  LWIP_ERROR("netconn_gethostbyname: invalid addr", (addr != NULL), return ERR_ARG;);
+#if LWIP_MPU_COMPATIBLE
+  if (strlen(name) >= DNS_MAX_NAME_LENGTH) {
+    return ERR_ARG;
+  }
+#endif
+
+  API_VAR_ALLOC(struct dns_api_msg, MEMP_DNS_API_MSG, msg, ERR_MEM);
+#if LWIP_MPU_COMPATIBLE
+  strncpy(API_VAR_REF(msg).name, name, DNS_MAX_NAME_LENGTH-1);
+  API_VAR_REF(msg).name[DNS_MAX_NAME_LENGTH-1] = 0;
+#else /* LWIP_MPU_COMPATIBLE */
+  msg.err = &err;
+  msg.sem = &sem;
+  API_VAR_REF(msg).addr = API_VAR_REF(addr);
+  API_VAR_REF(msg).name = name;
+#endif /* LWIP_MPU_COMPATIBLE */
+#if LWIP_IPV4 && LWIP_IPV6
+  API_VAR_REF(msg).dns_addrtype = dns_addrtype;
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+#if LWIP_NETCONN_SEM_PER_THREAD
+  API_VAR_REF(msg).sem = LWIP_NETCONN_THREAD_SEM_GET();
+#else /* LWIP_NETCONN_SEM_PER_THREAD*/
+  err = sys_sem_new(API_EXPR_REF(API_VAR_REF(msg).sem), 0);
+  if (err != ERR_OK) {
+    API_VAR_FREE(MEMP_DNS_API_MSG, msg);
+    return err;
+  }
+#endif /* LWIP_NETCONN_SEM_PER_THREAD */
+
+  err = tcpip_callback(lwip_netconn_do_gethostbyname, &API_VAR_REF(msg));
+  if (err != ERR_OK) {
+#if !LWIP_NETCONN_SEM_PER_THREAD
+    sys_sem_free(API_EXPR_REF(API_VAR_REF(msg).sem));
+#endif /* !LWIP_NETCONN_SEM_PER_THREAD */
+    API_VAR_FREE(MEMP_DNS_API_MSG, msg);
+    return err;
+  }
+  sys_sem_wait(API_EXPR_REF_SEM(API_VAR_REF(msg).sem));
+#if !LWIP_NETCONN_SEM_PER_THREAD
+  sys_sem_free(API_EXPR_REF(API_VAR_REF(msg).sem));
+#endif /* !LWIP_NETCONN_SEM_PER_THREAD */
+
+#if LWIP_MPU_COMPATIBLE
+  *addr = msg->addr;
+  err = msg->err;
+#endif /* LWIP_MPU_COMPATIBLE */
+
+  API_VAR_FREE(MEMP_DNS_API_MSG, msg);
+  return err;
+}
+#endif /* LWIP_DNS*/
+
+#if LWIP_NETCONN_SEM_PER_THREAD
+void
+netconn_thread_init(void)
+{
+  sys_sem_t *sem = LWIP_NETCONN_THREAD_SEM_GET();
+  if ((sem == NULL) || !sys_sem_valid(sem)) {
+    /* call alloc only once */
+    LWIP_NETCONN_THREAD_SEM_ALLOC();
+    LWIP_ASSERT("LWIP_NETCONN_THREAD_SEM_ALLOC() failed", sys_sem_valid(LWIP_NETCONN_THREAD_SEM_GET()));
+  }
+}
+
+void
+netconn_thread_cleanup(void)
+{
+  sys_sem_t *sem = LWIP_NETCONN_THREAD_SEM_GET();
+  if ((sem != NULL) && sys_sem_valid(sem)) {
+    /* call free only once */
+    LWIP_NETCONN_THREAD_SEM_FREE();
+  }
+}
+#endif /* LWIP_NETCONN_SEM_PER_THREAD */
+
+#endif /* LWIP_NETCONN */

ext/lwip/src/api/err.c

@@ -0,0 +1,75 @@
+/**
+ * @file
+ * Error Management module
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/err.h"
+
+#ifdef LWIP_DEBUG
+
+static const char *err_strerr[] = {
+           "Ok.",                    /* ERR_OK          0  */
+           "Out of memory error.",   /* ERR_MEM        -1  */
+           "Buffer error.",          /* ERR_BUF        -2  */
+           "Timeout.",               /* ERR_TIMEOUT    -3  */
+           "Routing problem.",       /* ERR_RTE        -4  */
+           "Operation in progress.", /* ERR_INPROGRESS -5  */
+           "Illegal value.",         /* ERR_VAL        -6  */
+           "Operation would block.", /* ERR_WOULDBLOCK -7  */
+           "Address in use.",        /* ERR_USE        -8  */
+           "Already connecting.",    /* ERR_ALREADY    -9  */
+           "Already connected.",     /* ERR_ISCONN     -10 */
+           "Not connected.",         /* ERR_CONN       -11 */
+           "Low-level netif error.", /* ERR_IF         -12 */
+           "Connection aborted.",    /* ERR_ABRT       -13 */
+           "Connection reset.",      /* ERR_RST        -14 */
+           "Connection closed.",     /* ERR_CLSD       -15 */
+           "Illegal argument."       /* ERR_ARG        -16 */
+};
+
+/**
+ * Convert an lwip internal error to a string representation.
+ *
+ * @param err an lwip internal err_t
+ * @return a string representation for err
+ */
+const char *
+lwip_strerr(err_t err)
+{
+  return err_strerr[-err];
+}
+
+#endif /* LWIP_DEBUG */

ext/lwip/src/api/netbuf.c

@@ -0,0 +1,263 @@
+/**
+ * @file
+ * Network buffer management
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+/**
+ * @defgroup netbuf Network buffers
+ * @ingroup netconn
+ * Network buffer descriptor for @ref netconn. Based on @ref pbuf internally
+ * to avoid copying data around.\n
+ * Buffers must not be shared accross multiple threads, all functions except
+ * netbuf_new() and netbuf_delete() are not thread-safe.
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_NETCONN /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/netbuf.h"
+#include "lwip/memp.h"
+
+#include <string.h>
+
+/**
+ * @ingroup netbuf
+ * Create (allocate) and initialize a new netbuf.
+ * The netbuf doesn't yet contain a packet buffer!
+ *
+ * @return a pointer to a new netbuf
+ *         NULL on lack of memory
+ */
+struct
+netbuf *netbuf_new(void)
+{
+  struct netbuf *buf;
+
+  buf = (struct netbuf *)memp_malloc(MEMP_NETBUF);
+  if (buf != NULL) {
+    buf->p = NULL;
+    buf->ptr = NULL;
+    ip_addr_set_zero(&buf->addr);
+    buf->port = 0;
+#if LWIP_NETBUF_RECVINFO || LWIP_CHECKSUM_ON_COPY
+#if LWIP_CHECKSUM_ON_COPY
+    buf->flags = 0;
+#endif /* LWIP_CHECKSUM_ON_COPY */
+    buf->toport_chksum = 0;
+#if LWIP_NETBUF_RECVINFO
+    ip_addr_set_zero(&buf->toaddr);
+#endif /* LWIP_NETBUF_RECVINFO */
+#endif /* LWIP_NETBUF_RECVINFO || LWIP_CHECKSUM_ON_COPY */
+    return buf;
+  } else {
+    return NULL;
+  }
+}
+
+/**
+ * @ingroup netbuf
+ * Deallocate a netbuf allocated by netbuf_new().
+ *
+ * @param buf pointer to a netbuf allocated by netbuf_new()
+ */
+void
+netbuf_delete(struct netbuf *buf)
+{
+  if (buf != NULL) {
+    if (buf->p != NULL) {
+      pbuf_free(buf->p);
+      buf->p = buf->ptr = NULL;
+    }
+    memp_free(MEMP_NETBUF, buf);
+  }
+}
+
+/**
+ * @ingroup netbuf
+ * Allocate memory for a packet buffer for a given netbuf.
+ *
+ * @param buf the netbuf for which to allocate a packet buffer
+ * @param size the size of the packet buffer to allocate
+ * @return pointer to the allocated memory
+ *         NULL if no memory could be allocated
+ */
+void *
+netbuf_alloc(struct netbuf *buf, u16_t size)
+{
+  LWIP_ERROR("netbuf_alloc: invalid buf", (buf != NULL), return NULL;);
+
+  /* Deallocate any previously allocated memory. */
+  if (buf->p != NULL) {
+    pbuf_free(buf->p);
+  }
+  buf->p = pbuf_alloc(PBUF_TRANSPORT, size, PBUF_RAM);
+  if (buf->p == NULL) {
+     return NULL;
+  }
+  LWIP_ASSERT("check that first pbuf can hold size",
+             (buf->p->len >= size));
+  buf->ptr = buf->p;
+  return buf->p->payload;
+}
+
+/**
+ * @ingroup netbuf
+ * Free the packet buffer included in a netbuf
+ *
+ * @param buf pointer to the netbuf which contains the packet buffer to free
+ */
+void
+netbuf_free(struct netbuf *buf)
+{
+  LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;);
+  if (buf->p != NULL) {
+    pbuf_free(buf->p);
+  }
+  buf->p = buf->ptr = NULL;
+}
+
+/**
+ * @ingroup netbuf
+ * Let a netbuf reference existing (non-volatile) data.
+ *
+ * @param buf netbuf which should reference the data
+ * @param dataptr pointer to the data to reference
+ * @param size size of the data
+ * @return ERR_OK if data is referenced
+ *         ERR_MEM if data couldn't be referenced due to lack of memory
+ */
+err_t
+netbuf_ref(struct netbuf *buf, const void *dataptr, u16_t size)
+{
+  LWIP_ERROR("netbuf_ref: invalid buf", (buf != NULL), return ERR_ARG;);
+  if (buf->p != NULL) {
+    pbuf_free(buf->p);
+  }
+  buf->p = pbuf_alloc(PBUF_TRANSPORT, 0, PBUF_REF);
+  if (buf->p == NULL) {
+    buf->ptr = NULL;
+    return ERR_MEM;
+  }
+  ((struct pbuf_rom*)buf->p)->payload = dataptr;
+  buf->p->len = buf->p->tot_len = size;
+  buf->ptr = buf->p;
+  return ERR_OK;
+}
+
+/**
+ * @ingroup netbuf
+ * Chain one netbuf to another (@see pbuf_chain)
+ *
+ * @param head the first netbuf
+ * @param tail netbuf to chain after head, freed by this function, may not be reference after returning
+ */
+void
+netbuf_chain(struct netbuf *head, struct netbuf *tail)
+{
+  LWIP_ERROR("netbuf_ref: invalid head", (head != NULL), return;);
+  LWIP_ERROR("netbuf_chain: invalid tail", (tail != NULL), return;);
+  pbuf_cat(head->p, tail->p);
+  head->ptr = head->p;
+  memp_free(MEMP_NETBUF, tail);
+}
+
+/**
+ * @ingroup netbuf
+ * Get the data pointer and length of the data inside a netbuf.
+ *
+ * @param buf netbuf to get the data from
+ * @param dataptr pointer to a void pointer where to store the data pointer
+ * @param len pointer to an u16_t where the length of the data is stored
+ * @return ERR_OK if the information was retrieved,
+ *         ERR_BUF on error.
+ */
+err_t
+netbuf_data(struct netbuf *buf, void **dataptr, u16_t *len)
+{
+  LWIP_ERROR("netbuf_data: invalid buf", (buf != NULL), return ERR_ARG;);
+  LWIP_ERROR("netbuf_data: invalid dataptr", (dataptr != NULL), return ERR_ARG;);
+  LWIP_ERROR("netbuf_data: invalid len", (len != NULL), return ERR_ARG;);
+
+  if (buf->ptr == NULL) {
+    return ERR_BUF;
+  }
+  *dataptr = buf->ptr->payload;
+  *len = buf->ptr->len;
+  return ERR_OK;
+}
+
+/**
+ * @ingroup netbuf
+ * Move the current data pointer of a packet buffer contained in a netbuf
+ * to the next part.
+ * The packet buffer itself is not modified.
+ *
+ * @param buf the netbuf to modify
+ * @return -1 if there is no next part
+ *         1  if moved to the next part but now there is no next part
+ *         0  if moved to the next part and there are still more parts
+ */
+s8_t
+netbuf_next(struct netbuf *buf)
+{
+  LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return -1;);
+  if (buf->ptr->next == NULL) {
+    return -1;
+  }
+  buf->ptr = buf->ptr->next;
+  if (buf->ptr->next == NULL) {
+    return 1;
+  }
+  return 0;
+}
+
+/**
+ * @ingroup netbuf
+ * Move the current data pointer of a packet buffer contained in a netbuf
+ * to the beginning of the packet.
+ * The packet buffer itself is not modified.
+ *
+ * @param buf the netbuf to modify
+ */
+void
+netbuf_first(struct netbuf *buf)
+{
+  LWIP_ERROR("netbuf_free: invalid buf", (buf != NULL), return;);
+  buf->ptr = buf->p;
+}
+
+#endif /* LWIP_NETCONN */

ext/lwip/src/api/netdb.c

@@ -0,0 +1,417 @@
+/**
+ * @file
+ * API functions for name resolving
+ *
+ */
+
+/*
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Simon Goldschmidt
+ *
+ */
+
+
+/**
+ * @defgroup netdbapi NETDB API
+ * @ingroup socket
+ */
+
+#include "lwip/netdb.h"
+
+#if LWIP_DNS && LWIP_SOCKET
+
+#include "lwip/err.h"
+#include "lwip/mem.h"
+#include "lwip/memp.h"
+#include "lwip/ip_addr.h"
+#include "lwip/api.h"
+#include "lwip/dns.h"
+
+#include <string.h>
+#include <stdlib.h>
+
+/** helper struct for gethostbyname_r to access the char* buffer */
+struct gethostbyname_r_helper {
+  ip_addr_t *addr_list[2];
+  ip_addr_t addr;
+  char *aliases;
+};
+
+/** h_errno is exported in netdb.h for access by applications. */
+#if LWIP_DNS_API_DECLARE_H_ERRNO
+int h_errno;
+#endif /* LWIP_DNS_API_DECLARE_H_ERRNO */
+
+/** define "hostent" variables storage: 0 if we use a static (but unprotected)
+ * set of variables for lwip_gethostbyname, 1 if we use a local storage */
+#ifndef LWIP_DNS_API_HOSTENT_STORAGE
+#define LWIP_DNS_API_HOSTENT_STORAGE 0
+#endif
+
+/** define "hostent" variables storage */
+#if LWIP_DNS_API_HOSTENT_STORAGE
+#define HOSTENT_STORAGE
+#else
+#define HOSTENT_STORAGE static
+#endif /* LWIP_DNS_API_STATIC_HOSTENT */
+
+/**
+ * Returns an entry containing addresses of address family AF_INET
+ * for the host with name name.
+ * Due to dns_gethostbyname limitations, only one address is returned.
+ *
+ * @param name the hostname to resolve
+ * @return an entry containing addresses of address family AF_INET
+ *         for the host with name name
+ */
+struct hostent*
+lwip_gethostbyname(const char *name)
+{
+  err_t err;
+  ip_addr_t addr;
+
+  /* buffer variables for lwip_gethostbyname() */
+  HOSTENT_STORAGE struct hostent s_hostent;
+  HOSTENT_STORAGE char *s_aliases;
+  HOSTENT_STORAGE ip_addr_t s_hostent_addr;
+  HOSTENT_STORAGE ip_addr_t *s_phostent_addr[2];
+  HOSTENT_STORAGE char s_hostname[DNS_MAX_NAME_LENGTH + 1];
+
+  /* query host IP address */
+  err = netconn_gethostbyname(name, &addr);
+  if (err != ERR_OK) {
+    LWIP_DEBUGF(DNS_DEBUG, ("lwip_gethostbyname(%s) failed, err=%d\n", name, err));
+    h_errno = HOST_NOT_FOUND;
+    return NULL;
+  }
+
+  /* fill hostent */
+  s_hostent_addr = addr;
+  s_phostent_addr[0] = &s_hostent_addr;
+  s_phostent_addr[1] = NULL;
+  strncpy(s_hostname, name, DNS_MAX_NAME_LENGTH);
+  s_hostname[DNS_MAX_NAME_LENGTH] = 0;
+  s_hostent.h_name = s_hostname;
+  s_aliases = NULL;
+  s_hostent.h_aliases = &s_aliases;
+  s_hostent.h_addrtype = AF_INET;
+  s_hostent.h_length = sizeof(ip_addr_t);
+  s_hostent.h_addr_list = (char**)&s_phostent_addr;
+
+#if DNS_DEBUG
+  /* dump hostent */
+  LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_name           == %s\n", s_hostent.h_name));
+  LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_aliases        == %p\n", (void*)s_hostent.h_aliases));
+  /* h_aliases are always empty */
+  LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addrtype       == %d\n", s_hostent.h_addrtype));
+  LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_length         == %d\n", s_hostent.h_length));
+  LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addr_list      == %p\n", (void*)s_hostent.h_addr_list));
+  if (s_hostent.h_addr_list != NULL) {
+    u8_t idx;
+    for (idx=0; s_hostent.h_addr_list[idx]; idx++) {
+      LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addr_list[%i]   == %p\n", idx, s_hostent.h_addr_list[idx]));
+      LWIP_DEBUGF(DNS_DEBUG, ("hostent.h_addr_list[%i]-> == %s\n", idx, ipaddr_ntoa((ip_addr_t*)s_hostent.h_addr_list[idx])));
+    }
+  }
+#endif /* DNS_DEBUG */
+
+#if LWIP_DNS_API_HOSTENT_STORAGE
+  /* this function should return the "per-thread" hostent after copy from s_hostent */
+  return sys_thread_hostent(&s_hostent);
+#else
+  return &s_hostent;
+#endif /* LWIP_DNS_API_HOSTENT_STORAGE */
+}
+
+/**
+ * Thread-safe variant of lwip_gethostbyname: instead of using a static
+ * buffer, this function takes buffer and errno pointers as arguments
+ * and uses these for the result.
+ *
+ * @param name the hostname to resolve
+ * @param ret pre-allocated struct where to store the result
+ * @param buf pre-allocated buffer where to store additional data
+ * @param buflen the size of buf
+ * @param result pointer to a hostent pointer that is set to ret on success
+ *               and set to zero on error
+ * @param h_errnop pointer to an int where to store errors (instead of modifying
+ *                 the global h_errno)
+ * @return 0 on success, non-zero on error, additional error information
+ *         is stored in *h_errnop instead of h_errno to be thread-safe
+ */
+int
+lwip_gethostbyname_r(const char *name, struct hostent *ret, char *buf,
+                size_t buflen, struct hostent **result, int *h_errnop)
+{
+  err_t err;
+  struct gethostbyname_r_helper *h;
+  char *hostname;
+  size_t namelen;
+  int lh_errno;
+
+  if (h_errnop == NULL) {
+    /* ensure h_errnop is never NULL */
+    h_errnop = &lh_errno;
+  }
+
+  if (result == NULL) {
+    /* not all arguments given */
+    *h_errnop = EINVAL;
+    return -1;
+  }
+  /* first thing to do: set *result to nothing */
+  *result = NULL;
+  if ((name == NULL) || (ret == NULL) || (buf == NULL)) {
+    /* not all arguments given */
+    *h_errnop = EINVAL;
+    return -1;
+  }
+
+  namelen = strlen(name);
+  if (buflen < (sizeof(struct gethostbyname_r_helper) + namelen + 1 + (MEM_ALIGNMENT - 1))) {
+    /* buf can't hold the data needed + a copy of name */
+    *h_errnop = ERANGE;
+    return -1;
+  }
+
+  h = (struct gethostbyname_r_helper*)LWIP_MEM_ALIGN(buf);
+  hostname = ((char*)h) + sizeof(struct gethostbyname_r_helper);
+
+  /* query host IP address */
+  err = netconn_gethostbyname(name, &h->addr);
+  if (err != ERR_OK) {
+    LWIP_DEBUGF(DNS_DEBUG, ("lwip_gethostbyname(%s) failed, err=%d\n", name, err));
+    *h_errnop = HOST_NOT_FOUND;
+    return -1;
+  }
+
+  /* copy the hostname into buf */
+  MEMCPY(hostname, name, namelen);
+  hostname[namelen] = 0;
+
+  /* fill hostent */
+  h->addr_list[0] = &h->addr;
+  h->addr_list[1] = NULL;
+  h->aliases = NULL;
+  ret->h_name = hostname;
+  ret->h_aliases = &h->aliases;
+  ret->h_addrtype = AF_INET;
+  ret->h_length = sizeof(ip_addr_t);
+  ret->h_addr_list = (char**)&h->addr_list;
+
+  /* set result != NULL */
+  *result = ret;
+
+  /* return success */
+  return 0;
+}
+
+/**
+ * Frees one or more addrinfo structures returned by getaddrinfo(), along with
+ * any additional storage associated with those structures. If the ai_next field
+ * of the structure is not null, the entire list of structures is freed.
+ *
+ * @param ai struct addrinfo to free
+ */
+void
+lwip_freeaddrinfo(struct addrinfo *ai)
+{
+  struct addrinfo *next;
+
+  while (ai != NULL) {
+    next = ai->ai_next;
+    memp_free(MEMP_NETDB, ai);
+    ai = next;
+  }
+}
+
+/**
+ * Translates the name of a service location (for example, a host name) and/or
+ * a service name and returns a set of socket addresses and associated
+ * information to be used in creating a socket with which to address the
+ * specified service.
+ * Memory for the result is allocated internally and must be freed by calling
+ * lwip_freeaddrinfo()!
+ *
+ * Due to a limitation in dns_gethostbyname, only the first address of a
+ * host is returned.
+ * Also, service names are not supported (only port numbers)!
+ *
+ * @param nodename descriptive name or address string of the host
+ *                 (may be NULL -> local address)
+ * @param servname port number as string of NULL
+ * @param hints structure containing input values that set socktype and protocol
+ * @param res pointer to a pointer where to store the result (set to NULL on failure)
+ * @return 0 on success, non-zero on failure
+ *
+ * @todo: implement AI_V4MAPPED, AI_ADDRCONFIG
+ */
+int
+lwip_getaddrinfo(const char *nodename, const char *servname,
+       const struct addrinfo *hints, struct addrinfo **res)
+{
+  err_t err;
+  ip_addr_t addr;
+  struct addrinfo *ai;
+  struct sockaddr_storage *sa = NULL;
+  int port_nr = 0;
+  size_t total_size;
+  size_t namelen = 0;
+  int ai_family;
+
+  if (res == NULL) {
+    return EAI_FAIL;
+  }
+  *res = NULL;
+  if ((nodename == NULL) && (servname == NULL)) {
+    return EAI_NONAME;
+  }
+
+  if (hints != NULL) {
+    ai_family = hints->ai_family;
+    if ((ai_family != AF_UNSPEC)
+#if LWIP_IPV4
+      && (ai_family != AF_INET)
+#endif /* LWIP_IPV4 */
+#if LWIP_IPV6
+      && (ai_family != AF_INET6)
+#endif /* LWIP_IPV6 */
+      ) {
+      return EAI_FAMILY;
+    }
+  } else {
+    ai_family = AF_UNSPEC;
+  }
+
+  if (servname != NULL) {
+    /* service name specified: convert to port number
+     * @todo?: currently, only ASCII integers (port numbers) are supported (AI_NUMERICSERV)! */
+    port_nr = atoi(servname);
+    if ((port_nr <= 0) || (port_nr > 0xffff)) {
+      return EAI_SERVICE;
+    }
+  }
+
+  if (nodename != NULL) {
+    /* service location specified, try to resolve */
+    if ((hints != NULL) && (hints->ai_flags & AI_NUMERICHOST)) {
+      /* no DNS lookup, just parse for an address string */
+      if (!ipaddr_aton(nodename, &addr)) {
+        return EAI_NONAME;
+      }
+#if LWIP_IPV4 && LWIP_IPV6
+      if ((IP_IS_V6_VAL(addr) && ai_family == AF_INET) ||
+          (IP_IS_V4_VAL(addr) && ai_family == AF_INET6)) {
+        return EAI_NONAME;
+      }
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+    } else {
+#if LWIP_IPV4 && LWIP_IPV6
+      /* AF_UNSPEC: prefer IPv4 */
+      u8_t type = NETCONN_DNS_IPV4_IPV6;
+      if (ai_family == AF_INET) {
+        type = NETCONN_DNS_IPV4;
+      } else if (ai_family == AF_INET6) {
+        type = NETCONN_DNS_IPV6;
+      }
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+      err = netconn_gethostbyname_addrtype(nodename, &addr, type);
+      if (err != ERR_OK) {
+        return EAI_FAIL;
+      }
+    }
+  } else {
+    /* service location specified, use loopback address */
+    if ((hints != NULL) && (hints->ai_flags & AI_PASSIVE)) {
+      ip_addr_set_any(ai_family == AF_INET6, &addr);
+    } else {
+      ip_addr_set_loopback(ai_family == AF_INET6, &addr);
+    }
+  }
+
+  total_size = sizeof(struct addrinfo) + sizeof(struct sockaddr_storage);
+  if (nodename != NULL) {
+    namelen = strlen(nodename);
+    if (namelen > DNS_MAX_NAME_LENGTH) {
+      /* invalid name length */
+      return EAI_FAIL;
+    }
+    LWIP_ASSERT("namelen is too long", total_size + namelen + 1 > total_size);
+    total_size += namelen + 1;
+  }
+  /* If this fails, please report to lwip-devel! :-) */
+  LWIP_ASSERT("total_size <= NETDB_ELEM_SIZE: please report this!",
+    total_size <= NETDB_ELEM_SIZE);
+  ai = (struct addrinfo *)memp_malloc(MEMP_NETDB);
+  if (ai == NULL) {
+    return EAI_MEMORY;
+  }
+  memset(ai, 0, total_size);
+  /* cast through void* to get rid of alignment warnings */
+  sa = (struct sockaddr_storage *)(void*)((u8_t*)ai + sizeof(struct addrinfo));
+  if (IP_IS_V6_VAL(addr)) {
+#if LWIP_IPV6
+    struct sockaddr_in6 *sa6 = (struct sockaddr_in6*)sa;
+    /* set up sockaddr */
+    inet6_addr_from_ip6addr(&sa6->sin6_addr, ip_2_ip6(&addr));
+    sa6->sin6_family = AF_INET6;
+    sa6->sin6_len = sizeof(struct sockaddr_in6);
+    sa6->sin6_port = htons((u16_t)port_nr);
+    ai->ai_family = AF_INET6;
+#endif /* LWIP_IPV6 */
+  } else {
+#if LWIP_IPV4
+    struct sockaddr_in *sa4 = (struct sockaddr_in*)sa;
+    /* set up sockaddr */
+    inet_addr_from_ipaddr(&sa4->sin_addr, ip_2_ip4(&addr));
+    sa4->sin_family = AF_INET;
+    sa4->sin_len = sizeof(struct sockaddr_in);
+    sa4->sin_port = htons((u16_t)port_nr);
+    ai->ai_family = AF_INET;
+#endif /* LWIP_IPV4 */
+  }
+
+  /* set up addrinfo */
+  if (hints != NULL) {
+    /* copy socktype & protocol from hints if specified */
+    ai->ai_socktype = hints->ai_socktype;
+    ai->ai_protocol = hints->ai_protocol;
+  }
+  if (nodename != NULL) {
+    /* copy nodename to canonname if specified */
+    ai->ai_canonname = ((char*)ai + sizeof(struct addrinfo) + sizeof(struct sockaddr_storage));
+    MEMCPY(ai->ai_canonname, nodename, namelen);
+    ai->ai_canonname[namelen] = 0;
+  }
+  ai->ai_addrlen = sizeof(struct sockaddr_storage);
+  ai->ai_addr = (struct sockaddr*)sa;
+
+  *res = ai;
+
+  return 0;
+}
+
+#endif /* LWIP_DNS && LWIP_SOCKET */

ext/lwip/src/api/netifapi.c

@@ -0,0 +1,224 @@
+/**
+ * @file
+ * Network Interface Sequential API module
+ *
+ */
+
+/*
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ */
+
+/**
+ * @defgroup netifapi NETIF API
+ * @ingroup threadsafe_api
+ * Thread-safe functions to be called from non-TCPIP threads
+ * 
+ * @defgroup netifapi_netif NETIF related
+ * @ingroup netifapi
+ * To be called from non-TCPIP threads 
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_NETIF_API /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/netifapi.h"
+#include "lwip/memp.h"
+#include "lwip/priv/tcpip_priv.h"
+
+#define NETIFAPI_VAR_REF(name)      API_VAR_REF(name)
+#define NETIFAPI_VAR_DECLARE(name)  API_VAR_DECLARE(struct netifapi_msg, name)
+#define NETIFAPI_VAR_ALLOC(name)    API_VAR_ALLOC(struct netifapi_msg, MEMP_NETIFAPI_MSG, name, ERR_MEM)
+#define NETIFAPI_VAR_FREE(name)     API_VAR_FREE(MEMP_NETIFAPI_MSG, name)
+
+/**
+ * Call netif_add() inside the tcpip_thread context.
+ */
+static err_t
+netifapi_do_netif_add(struct tcpip_api_call_data *m)
+{
+  /* cast through void* to silence alignment warnings. 
+   * We know it works because the structs have been instantiated as struct netifapi_msg */
+  struct netifapi_msg *msg = (struct netifapi_msg*)(void*)m;
+  
+  if (!netif_add( msg->netif,
+#if LWIP_IPV4
+                  API_EXPR_REF(msg->msg.add.ipaddr),
+                  API_EXPR_REF(msg->msg.add.netmask),
+                  API_EXPR_REF(msg->msg.add.gw),
+#endif /* LWIP_IPV4 */
+                  msg->msg.add.state,
+                  msg->msg.add.init,
+                  msg->msg.add.input)) {
+    return ERR_IF;
+  } else {
+    return ERR_OK;
+  }
+}
+
+#if LWIP_IPV4
+/**
+ * Call netif_set_addr() inside the tcpip_thread context.
+ */
+static err_t
+netifapi_do_netif_set_addr(struct tcpip_api_call_data *m)
+{
+  /* cast through void* to silence alignment warnings. 
+   * We know it works because the structs have been instantiated as struct netifapi_msg */
+  struct netifapi_msg *msg = (struct netifapi_msg*)(void*)m;
+
+  netif_set_addr( msg->netif,
+                  API_EXPR_REF(msg->msg.add.ipaddr),
+                  API_EXPR_REF(msg->msg.add.netmask),
+                  API_EXPR_REF(msg->msg.add.gw));
+  return ERR_OK;
+}
+#endif /* LWIP_IPV4 */
+
+/**
+ * Call the "errtfunc" (or the "voidfunc" if "errtfunc" is NULL) inside the
+ * tcpip_thread context.
+ */
+static err_t
+netifapi_do_netif_common(struct tcpip_api_call_data *m)
+{
+  /* cast through void* to silence alignment warnings. 
+   * We know it works because the structs have been instantiated as struct netifapi_msg */
+  struct netifapi_msg *msg = (struct netifapi_msg*)(void*)m;
+
+  if (msg->msg.common.errtfunc != NULL) {
+    return msg->msg.common.errtfunc(msg->netif);
+  } else {
+    msg->msg.common.voidfunc(msg->netif);
+    return ERR_OK;
+  }
+}
+
+/**
+ * @ingroup netifapi_netif
+ * Call netif_add() in a thread-safe way by running that function inside the
+ * tcpip_thread context.
+ *
+ * @note for params @see netif_add()
+ */
+err_t
+netifapi_netif_add(struct netif *netif,
+#if LWIP_IPV4
+                   const ip4_addr_t *ipaddr, const ip4_addr_t *netmask, const ip4_addr_t *gw,
+#endif /* LWIP_IPV4 */
+                   void *state, netif_init_fn init, netif_input_fn input)
+{
+  err_t err;
+  NETIFAPI_VAR_DECLARE(msg);
+  NETIFAPI_VAR_ALLOC(msg);
+
+#if LWIP_IPV4
+  if (ipaddr == NULL) {
+    ipaddr = IP4_ADDR_ANY;
+  }
+  if (netmask == NULL) {
+    netmask = IP4_ADDR_ANY;
+  }
+  if (gw == NULL) {
+    gw = IP4_ADDR_ANY;
+  }
+#endif /* LWIP_IPV4 */
+
+  NETIFAPI_VAR_REF(msg).netif = netif;
+#if LWIP_IPV4
+  NETIFAPI_VAR_REF(msg).msg.add.ipaddr  = NETIFAPI_VAR_REF(ipaddr);
+  NETIFAPI_VAR_REF(msg).msg.add.netmask = NETIFAPI_VAR_REF(netmask);
+  NETIFAPI_VAR_REF(msg).msg.add.gw      = NETIFAPI_VAR_REF(gw);
+#endif /* LWIP_IPV4 */
+  NETIFAPI_VAR_REF(msg).msg.add.state   = state;
+  NETIFAPI_VAR_REF(msg).msg.add.init    = init;
+  NETIFAPI_VAR_REF(msg).msg.add.input   = input;
+  err = tcpip_api_call(netifapi_do_netif_add, &API_VAR_REF(msg).call);
+  NETIFAPI_VAR_FREE(msg);
+  return err;
+}
+
+#if LWIP_IPV4
+/**
+ * @ingroup netifapi_netif
+ * Call netif_set_addr() in a thread-safe way by running that function inside the
+ * tcpip_thread context.
+ *
+ * @note for params @see netif_set_addr()
+ */
+err_t
+netifapi_netif_set_addr(struct netif *netif,
+                        const ip4_addr_t *ipaddr,
+                        const ip4_addr_t *netmask,
+                        const ip4_addr_t *gw)
+{
+  err_t err;
+  NETIFAPI_VAR_DECLARE(msg);
+  NETIFAPI_VAR_ALLOC(msg);
+
+  if (ipaddr == NULL) {
+    ipaddr = IP4_ADDR_ANY;
+  }
+  if (netmask == NULL) {
+    netmask = IP4_ADDR_ANY;
+  }
+  if (gw == NULL) {
+    gw = IP4_ADDR_ANY;
+  }
+
+  NETIFAPI_VAR_REF(msg).netif = netif;
+  NETIFAPI_VAR_REF(msg).msg.add.ipaddr  = NETIFAPI_VAR_REF(ipaddr);
+  NETIFAPI_VAR_REF(msg).msg.add.netmask = NETIFAPI_VAR_REF(netmask);
+  NETIFAPI_VAR_REF(msg).msg.add.gw      = NETIFAPI_VAR_REF(gw);
+  err = tcpip_api_call(netifapi_do_netif_set_addr, &API_VAR_REF(msg).call);
+  NETIFAPI_VAR_FREE(msg);
+  return err;
+}
+#endif /* LWIP_IPV4 */
+
+/**
+ * call the "errtfunc" (or the "voidfunc" if "errtfunc" is NULL) in a thread-safe
+ * way by running that function inside the tcpip_thread context.
+ *
+ * @note use only for functions where there is only "netif" parameter.
+ */
+err_t
+netifapi_netif_common(struct netif *netif, netifapi_void_fn voidfunc,
+                       netifapi_errt_fn errtfunc)
+{
+  err_t err;
+  NETIFAPI_VAR_DECLARE(msg);
+  NETIFAPI_VAR_ALLOC(msg);
+
+  NETIFAPI_VAR_REF(msg).netif = netif;
+  NETIFAPI_VAR_REF(msg).msg.common.voidfunc = voidfunc;
+  NETIFAPI_VAR_REF(msg).msg.common.errtfunc = errtfunc;
+  err = tcpip_api_call(netifapi_do_netif_common, &API_VAR_REF(msg).call);
+  NETIFAPI_VAR_FREE(msg);
+  return err;
+}
+
+#endif /* LWIP_NETIF_API */

ext/lwip/src/api/tcpip.c

@@ -0,0 +1,511 @@
+/**
+ * @file
+ * Sequential API Main thread module
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/opt.h"
+
+#if !NO_SYS /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/priv/tcpip_priv.h"
+#include "lwip/sys.h"
+#include "lwip/memp.h"
+#include "lwip/mem.h"
+#include "lwip/init.h"
+#include "lwip/ip.h"
+#include "lwip/pbuf.h"
+#include "lwip/etharp.h"
+
+#define TCPIP_MSG_VAR_REF(name)     API_VAR_REF(name)
+#define TCPIP_MSG_VAR_DECLARE(name) API_VAR_DECLARE(struct tcpip_msg, name)
+#define TCPIP_MSG_VAR_ALLOC(name)   API_VAR_ALLOC(struct tcpip_msg, MEMP_TCPIP_MSG_API, name, ERR_MEM)
+#define TCPIP_MSG_VAR_FREE(name)    API_VAR_FREE(MEMP_TCPIP_MSG_API, name)
+
+/* global variables */
+static tcpip_init_done_fn tcpip_init_done;
+static void *tcpip_init_done_arg;
+static sys_mbox_t mbox;
+
+#if LWIP_TCPIP_CORE_LOCKING
+/** The global semaphore to lock the stack. */
+sys_mutex_t lock_tcpip_core;
+#endif /* LWIP_TCPIP_CORE_LOCKING */
+
+
+/**
+ * The main lwIP thread. This thread has exclusive access to lwIP core functions
+ * (unless access to them is not locked). Other threads communicate with this
+ * thread using message boxes.
+ *
+ * It also starts all the timers to make sure they are running in the right
+ * thread context.
+ *
+ * @param arg unused argument
+ */
+static void
+tcpip_thread(void *arg)
+{
+  struct tcpip_msg *msg;
+  LWIP_UNUSED_ARG(arg);
+
+  if (tcpip_init_done != NULL) {
+    tcpip_init_done(tcpip_init_done_arg);
+  }
+
+  LOCK_TCPIP_CORE();
+  while (1) {                          /* MAIN Loop */
+    UNLOCK_TCPIP_CORE();
+    LWIP_TCPIP_THREAD_ALIVE();
+    /* wait for a message, timeouts are processed while waiting */
+    sys_timeouts_mbox_fetch(&mbox, (void **)&msg);
+    LOCK_TCPIP_CORE();
+    if (msg == NULL) {
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: invalid message: NULL\n"));
+      LWIP_ASSERT("tcpip_thread: invalid message", 0);
+      continue;
+    }
+    switch (msg->type) {
+#if !LWIP_TCPIP_CORE_LOCKING
+    case TCPIP_MSG_API:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: API message %p\n", (void *)msg));
+      msg->msg.api_msg.function(msg->msg.api_msg.msg);
+      break;
+    case TCPIP_MSG_API_CALL:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: API CALL message %p\n", (void *)msg));
+      msg->msg.api_call.arg->err = msg->msg.api_call.function(msg->msg.api_call.arg);
+      sys_sem_signal(msg->msg.api_call.sem);
+      break;
+#endif /* !LWIP_TCPIP_CORE_LOCKING */
+
+#if !LWIP_TCPIP_CORE_LOCKING_INPUT
+    case TCPIP_MSG_INPKT:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: PACKET %p\n", (void *)msg));
+      msg->msg.inp.input_fn(msg->msg.inp.p, msg->msg.inp.netif);
+      memp_free(MEMP_TCPIP_MSG_INPKT, msg);
+      break;
+#endif /* !LWIP_TCPIP_CORE_LOCKING_INPUT */
+
+#if LWIP_TCPIP_TIMEOUT
+    case TCPIP_MSG_TIMEOUT:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: TIMEOUT %p\n", (void *)msg));
+      sys_timeout(msg->msg.tmo.msecs, msg->msg.tmo.h, msg->msg.tmo.arg);
+      memp_free(MEMP_TCPIP_MSG_API, msg);
+      break;
+    case TCPIP_MSG_UNTIMEOUT:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: UNTIMEOUT %p\n", (void *)msg));
+      sys_untimeout(msg->msg.tmo.h, msg->msg.tmo.arg);
+      memp_free(MEMP_TCPIP_MSG_API, msg);
+      break;
+#endif /* LWIP_TCPIP_TIMEOUT */
+
+    case TCPIP_MSG_CALLBACK:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: CALLBACK %p\n", (void *)msg));
+      msg->msg.cb.function(msg->msg.cb.ctx);
+      memp_free(MEMP_TCPIP_MSG_API, msg);
+      break;
+
+    case TCPIP_MSG_CALLBACK_STATIC:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: CALLBACK_STATIC %p\n", (void *)msg));
+      msg->msg.cb.function(msg->msg.cb.ctx);
+      break;
+
+    default:
+      LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_thread: invalid message: %d\n", msg->type));
+      LWIP_ASSERT("tcpip_thread: invalid message", 0);
+      break;
+    }
+  }
+}
+
+/**
+ * Pass a received packet to tcpip_thread for input processing
+ *
+ * @param p the received packet
+ * @param inp the network interface on which the packet was received
+ * @param input_fn input function to call
+ */
+err_t
+tcpip_inpkt(struct pbuf *p, struct netif *inp, netif_input_fn input_fn)
+{
+#if LWIP_TCPIP_CORE_LOCKING_INPUT
+  err_t ret;
+  LWIP_DEBUGF(TCPIP_DEBUG, ("tcpip_inpkt: PACKET %p/%p\n", (void *)p, (void *)inp));
+  LOCK_TCPIP_CORE();
+  ret = input_fn(p, inp);
+  UNLOCK_TCPIP_CORE();
+  return ret;
+#else /* LWIP_TCPIP_CORE_LOCKING_INPUT */
+  struct tcpip_msg *msg;
+
+  LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
+
+  msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_INPKT);
+  if (msg == NULL) {
+    return ERR_MEM;
+  }
+
+  msg->type = TCPIP_MSG_INPKT;
+  msg->msg.inp.p = p;
+  msg->msg.inp.netif = inp;
+  msg->msg.inp.input_fn = input_fn;
+  if (sys_mbox_trypost(&mbox, msg) != ERR_OK) {
+    memp_free(MEMP_TCPIP_MSG_INPKT, msg);
+    return ERR_MEM;
+  }
+  return ERR_OK;
+#endif /* LWIP_TCPIP_CORE_LOCKING_INPUT */
+}
+
+/**
+ * @ingroup lwip_os
+ * Pass a received packet to tcpip_thread for input processing with
+ * ethernet_input or ip_input. Don't call directly, pass to netif_add()
+ * and call netif->input().
+ *
+ * @param p the received packet, p->payload pointing to the Ethernet header or
+ *          to an IP header (if inp doesn't have NETIF_FLAG_ETHARP or
+ *          NETIF_FLAG_ETHERNET flags)
+ * @param inp the network interface on which the packet was received
+ */
+err_t
+tcpip_input(struct pbuf *p, struct netif *inp)
+{
+#if LWIP_ETHERNET
+  if (inp->flags & (NETIF_FLAG_ETHARP | NETIF_FLAG_ETHERNET)) {
+    return tcpip_inpkt(p, inp, ethernet_input);
+  } else
+#endif /* LWIP_ETHERNET */
+  return tcpip_inpkt(p, inp, ip_input);
+}
+
+/**
+ * Call a specific function in the thread context of
+ * tcpip_thread for easy access synchronization.
+ * A function called in that way may access lwIP core code
+ * without fearing concurrent access.
+ *
+ * @param function the function to call
+ * @param ctx parameter passed to f
+ * @param block 1 to block until the request is posted, 0 to non-blocking mode
+ * @return ERR_OK if the function was called, another err_t if not
+ */
+err_t
+tcpip_callback_with_block(tcpip_callback_fn function, void *ctx, u8_t block)
+{
+  struct tcpip_msg *msg;
+
+  LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
+
+  msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
+  if (msg == NULL) {
+    return ERR_MEM;
+  }
+
+  msg->type = TCPIP_MSG_CALLBACK;
+  msg->msg.cb.function = function;
+  msg->msg.cb.ctx = ctx;
+  if (block) {
+    sys_mbox_post(&mbox, msg);
+  } else {
+    if (sys_mbox_trypost(&mbox, msg) != ERR_OK) {
+      memp_free(MEMP_TCPIP_MSG_API, msg);
+      return ERR_MEM;
+    }
+  }
+  return ERR_OK;
+}
+
+#if LWIP_TCPIP_TIMEOUT
+/**
+ * call sys_timeout in tcpip_thread
+ *
+ * @param msec time in milliseconds for timeout
+ * @param h function to be called on timeout
+ * @param arg argument to pass to timeout function h
+ * @return ERR_MEM on memory error, ERR_OK otherwise
+ */
+err_t
+tcpip_timeout(u32_t msecs, sys_timeout_handler h, void *arg)
+{
+  struct tcpip_msg *msg;
+
+  LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
+
+  msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
+  if (msg == NULL) {
+    return ERR_MEM;
+  }
+
+  msg->type = TCPIP_MSG_TIMEOUT;
+  msg->msg.tmo.msecs = msecs;
+  msg->msg.tmo.h = h;
+  msg->msg.tmo.arg = arg;
+  sys_mbox_post(&mbox, msg);
+  return ERR_OK;
+}
+
+/**
+ * call sys_untimeout in tcpip_thread
+ *
+ * @param msec time in milliseconds for timeout
+ * @param h function to be called on timeout
+ * @param arg argument to pass to timeout function h
+ * @return ERR_MEM on memory error, ERR_OK otherwise
+ */
+err_t
+tcpip_untimeout(sys_timeout_handler h, void *arg)
+{
+  struct tcpip_msg *msg;
+
+  LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
+
+  msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
+  if (msg == NULL) {
+    return ERR_MEM;
+  }
+
+  msg->type = TCPIP_MSG_UNTIMEOUT;
+  msg->msg.tmo.h = h;
+  msg->msg.tmo.arg = arg;
+  sys_mbox_post(&mbox, msg);
+  return ERR_OK;
+}
+#endif /* LWIP_TCPIP_TIMEOUT */
+
+
+/**
+ * Sends a message to TCPIP thread to call a function. Caller thread blocks on
+ * on a provided semaphore, which ist NOT automatically signalled by TCPIP thread,
+ * this has to be done by the user.
+ * It is recommended to use LWIP_TCPIP_CORE_LOCKING since this is the way
+ * with least runtime overhead.
+ *
+ * @param fn function to be called from TCPIP thread
+ * @param apimsg argument to API function
+ * @param sem semaphore to wait on
+ * @return ERR_OK if the function was called, another err_t if not
+ */
+err_t
+tcpip_send_msg_wait_sem(tcpip_callback_fn fn, void *apimsg, sys_sem_t* sem)
+{
+#if LWIP_TCPIP_CORE_LOCKING
+  LWIP_UNUSED_ARG(sem);
+  LOCK_TCPIP_CORE();
+  fn(apimsg);
+  UNLOCK_TCPIP_CORE();
+  return ERR_OK;
+#else /* LWIP_TCPIP_CORE_LOCKING */
+  TCPIP_MSG_VAR_DECLARE(msg);
+
+  LWIP_ASSERT("semaphore not initialized", sys_sem_valid(sem));
+  LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
+
+  TCPIP_MSG_VAR_ALLOC(msg);
+  TCPIP_MSG_VAR_REF(msg).type = TCPIP_MSG_API;
+  TCPIP_MSG_VAR_REF(msg).msg.api_msg.function = fn;
+  TCPIP_MSG_VAR_REF(msg).msg.api_msg.msg = apimsg;
+  sys_mbox_post(&mbox, &TCPIP_MSG_VAR_REF(msg));
+  sys_arch_sem_wait(sem, 0);
+  TCPIP_MSG_VAR_FREE(msg);
+  return ERR_OK;
+#endif /* LWIP_TCPIP_CORE_LOCKING */
+}
+
+/**
+ * Synchronously calls function in TCPIP thread and waits for its completion.
+ * It is recommended to use LWIP_TCPIP_CORE_LOCKING (preferred) or
+ * LWIP_NETCONN_SEM_PER_THREAD. 
+ * If not, a semaphore is created and destroyed on every call which is usually
+ * an expensive/slow operation.
+ * @param fn Function to call
+ * @param call Call parameters
+ * @return Return value from tcpip_api_call_fn
+ */
+err_t
+tcpip_api_call(tcpip_api_call_fn fn, struct tcpip_api_call_data *call)
+{
+#if LWIP_TCPIP_CORE_LOCKING
+  err_t err;
+  LOCK_TCPIP_CORE();
+  err = fn(call);
+  UNLOCK_TCPIP_CORE();
+  return err;
+#else /* LWIP_TCPIP_CORE_LOCKING */
+  TCPIP_MSG_VAR_DECLARE(msg);
+
+#if !LWIP_NETCONN_SEM_PER_THREAD
+  err_t err = sys_sem_new(&call->sem, 0);
+  if (err != ERR_OK) {
+    return err;
+  }
+#endif /* LWIP_NETCONN_SEM_PER_THREAD */
+
+  LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
+    
+  TCPIP_MSG_VAR_ALLOC(msg);
+  TCPIP_MSG_VAR_REF(msg).type = TCPIP_MSG_API_CALL;
+  TCPIP_MSG_VAR_REF(msg).msg.api_call.arg = call;
+  TCPIP_MSG_VAR_REF(msg).msg.api_call.function = fn;
+#if LWIP_NETCONN_SEM_PER_THREAD
+  TCPIP_MSG_VAR_REF(msg).msg.api_call.sem = LWIP_NETCONN_THREAD_SEM_GET();
+#else /* LWIP_NETCONN_SEM_PER_THREAD */
+  TCPIP_MSG_VAR_REF(msg).msg.api_call.sem = &call->sem;
+#endif /* LWIP_NETCONN_SEM_PER_THREAD */
+  sys_mbox_post(&mbox, &TCPIP_MSG_VAR_REF(msg));
+  sys_arch_sem_wait(TCPIP_MSG_VAR_REF(msg).msg.api_call.sem, 0);
+  TCPIP_MSG_VAR_FREE(msg);
+
+#if !LWIP_NETCONN_SEM_PER_THREAD
+  sys_sem_free(&call->sem);
+#endif /* LWIP_NETCONN_SEM_PER_THREAD */
+
+  return call->err;
+#endif /* LWIP_TCPIP_CORE_LOCKING */
+}
+
+/**
+ * Allocate a structure for a static callback message and initialize it.
+ * This is intended to be used to send "static" messages from interrupt context.
+ *
+ * @param function the function to call
+ * @param ctx parameter passed to function
+ * @return a struct pointer to pass to tcpip_trycallback().
+ */
+struct tcpip_callback_msg*
+tcpip_callbackmsg_new(tcpip_callback_fn function, void *ctx)
+{
+  struct tcpip_msg *msg = (struct tcpip_msg *)memp_malloc(MEMP_TCPIP_MSG_API);
+  if (msg == NULL) {
+    return NULL;
+  }
+  msg->type = TCPIP_MSG_CALLBACK_STATIC;
+  msg->msg.cb.function = function;
+  msg->msg.cb.ctx = ctx;
+  return (struct tcpip_callback_msg*)msg;
+}
+
+/**
+ * Free a callback message allocated by tcpip_callbackmsg_new().
+ *
+ * @param msg the message to free
+ */
+void
+tcpip_callbackmsg_delete(struct tcpip_callback_msg* msg)
+{
+  memp_free(MEMP_TCPIP_MSG_API, msg);
+}
+
+/**
+ * Try to post a callback-message to the tcpip_thread mbox
+ * This is intended to be used to send "static" messages from interrupt context.
+ *
+ * @param msg pointer to the message to post
+ * @return sys_mbox_trypost() return code
+ */
+err_t
+tcpip_trycallback(struct tcpip_callback_msg* msg)
+{
+  LWIP_ASSERT("Invalid mbox", sys_mbox_valid_val(mbox));
+  return sys_mbox_trypost(&mbox, msg);
+}
+
+/**
+ * @ingroup lwip_os
+ * Initialize this module:
+ * - initialize all sub modules
+ * - start the tcpip_thread
+ *
+ * @param initfunc a function to call when tcpip_thread is running and finished initializing
+ * @param arg argument to pass to initfunc
+ */
+void
+tcpip_init(tcpip_init_done_fn initfunc, void *arg)
+{
+  lwip_init();
+
+  tcpip_init_done = initfunc;
+  tcpip_init_done_arg = arg;
+  if (sys_mbox_new(&mbox, TCPIP_MBOX_SIZE) != ERR_OK) {
+    LWIP_ASSERT("failed to create tcpip_thread mbox", 0);
+  }
+#if LWIP_TCPIP_CORE_LOCKING
+  if (sys_mutex_new(&lock_tcpip_core) != ERR_OK) {
+    LWIP_ASSERT("failed to create lock_tcpip_core", 0);
+  }
+#endif /* LWIP_TCPIP_CORE_LOCKING */
+
+  sys_thread_new(TCPIP_THREAD_NAME, tcpip_thread, NULL, TCPIP_THREAD_STACKSIZE, TCPIP_THREAD_PRIO);
+}
+
+/**
+ * Simple callback function used with tcpip_callback to free a pbuf
+ * (pbuf_free has a wrong signature for tcpip_callback)
+ *
+ * @param p The pbuf (chain) to be dereferenced.
+ */
+static void
+pbuf_free_int(void *p)
+{
+  struct pbuf *q = (struct pbuf *)p;
+  pbuf_free(q);
+}
+
+/**
+ * A simple wrapper function that allows you to free a pbuf from interrupt context.
+ *
+ * @param p The pbuf (chain) to be dereferenced.
+ * @return ERR_OK if callback could be enqueued, an err_t if not
+ */
+err_t
+pbuf_free_callback(struct pbuf *p)
+{
+  return tcpip_callback_with_block(pbuf_free_int, p, 0);
+}
+
+/**
+ * A simple wrapper function that allows you to free heap memory from
+ * interrupt context.
+ *
+ * @param m the heap memory to free
+ * @return ERR_OK if callback could be enqueued, an err_t if not
+ */
+err_t
+mem_free_callback(void *m)
+{
+  return tcpip_callback_with_block(mem_free, m, 0);
+}
+
+#endif /* !NO_SYS */

ext/lwip/src/apps/httpd/fs.c

@@ -0,0 +1,179 @@
+/*
+ * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
+ * All rights reserved. 
+ * 
+ * Redistribution and use in source and binary forms, with or without modification, 
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ * 
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/apps/httpd_opts.h"
+#include "lwip/def.h"
+#include "lwip/apps/fs.h"
+#include "fsdata.h"
+#include <string.h>
+
+
+#if HTTPD_USE_CUSTOM_FSDATA
+#include "fsdata_custom.c"
+#else /* HTTPD_USE_CUSTOM_FSDATA */
+#include "fsdata.c"
+#endif /* HTTPD_USE_CUSTOM_FSDATA */
+
+/*-----------------------------------------------------------------------------------*/
+
+#if LWIP_HTTPD_CUSTOM_FILES
+int fs_open_custom(struct fs_file *file, const char *name);
+void fs_close_custom(struct fs_file *file);
+#if LWIP_HTTPD_FS_ASYNC_READ
+u8_t fs_canread_custom(struct fs_file *file);
+u8_t fs_wait_read_custom(struct fs_file *file, fs_wait_cb callback_fn, void *callback_arg);
+int fs_read_async_custom(struct fs_file *file, char *buffer, int count, fs_wait_cb callback_fn, void *callback_arg);
+#else /* LWIP_HTTPD_FS_ASYNC_READ */
+int fs_read_custom(struct fs_file *file, char *buffer, int count);
+#endif /* LWIP_HTTPD_FS_ASYNC_READ */
+#endif /* LWIP_HTTPD_CUSTOM_FILES */
+
+/*-----------------------------------------------------------------------------------*/
+err_t
+fs_open(struct fs_file *file, const char *name)
+{
+  const struct fsdata_file *f;
+
+  if ((file == NULL) || (name == NULL)) {
+     return ERR_ARG;
+  }
+
+#if LWIP_HTTPD_CUSTOM_FILES
+  if (fs_open_custom(file, name)) {
+    file->is_custom_file = 1;
+    return ERR_OK;
+  }
+  file->is_custom_file = 0;
+#endif /* LWIP_HTTPD_CUSTOM_FILES */
+
+  for (f = FS_ROOT; f != NULL; f = f->next) {
+    if (!strcmp(name, (const char *)f->name)) {
+      file->data = (const char *)f->data;
+      file->len = f->len;
+      file->index = f->len;
+      file->pextension = NULL;
+      file->flags = f->flags;
+#if HTTPD_PRECALCULATED_CHECKSUM
+      file->chksum_count = f->chksum_count;
+      file->chksum = f->chksum;
+#endif /* HTTPD_PRECALCULATED_CHECKSUM */
+#if LWIP_HTTPD_FILE_STATE
+      file->state = fs_state_init(file, name);
+#endif /* #if LWIP_HTTPD_FILE_STATE */
+      return ERR_OK;
+    }
+  }
+  /* file not found */
+  return ERR_VAL;
+}
+
+/*-----------------------------------------------------------------------------------*/
+void
+fs_close(struct fs_file *file)
+{
+#if LWIP_HTTPD_CUSTOM_FILES
+  if (file->is_custom_file) {
+    fs_close_custom(file);
+  }
+#endif /* LWIP_HTTPD_CUSTOM_FILES */
+#if LWIP_HTTPD_FILE_STATE
+  fs_state_free(file, file->state);
+#endif /* #if LWIP_HTTPD_FILE_STATE */
+  LWIP_UNUSED_ARG(file);
+}
+/*-----------------------------------------------------------------------------------*/
+#if LWIP_HTTPD_DYNAMIC_FILE_READ
+#if LWIP_HTTPD_FS_ASYNC_READ
+int
+fs_read_async(struct fs_file *file, char *buffer, int count, fs_wait_cb callback_fn, void *callback_arg)
+#else /* LWIP_HTTPD_FS_ASYNC_READ */
+int
+fs_read(struct fs_file *file, char *buffer, int count)
+#endif /* LWIP_HTTPD_FS_ASYNC_READ */
+{
+  int read;
+  if(file->index == file->len) {
+    return FS_READ_EOF;
+  }
+#if LWIP_HTTPD_FS_ASYNC_READ
+  LWIP_UNUSED_ARG(callback_fn);
+  LWIP_UNUSED_ARG(callback_arg);
+#endif /* LWIP_HTTPD_FS_ASYNC_READ */
+#if LWIP_HTTPD_CUSTOM_FILES
+  if (file->is_custom_file) {
+#if LWIP_HTTPD_FS_ASYNC_READ
+    return fs_read_async_custom(file, buffer, count, callback_fn, callback_arg);
+#else /* LWIP_HTTPD_FS_ASYNC_READ */
+    return fs_read_custom(file, buffer, count);
+#endif /* LWIP_HTTPD_FS_ASYNC_READ */
+  }
+#endif /* LWIP_HTTPD_CUSTOM_FILES */
+
+  read = file->len - file->index;
+  if(read > count) {
+    read = count;
+  }
+
+  MEMCPY(buffer, (file->data + file->index), read);
+  file->index += read;
+
+  return(read);
+}
+#endif /* LWIP_HTTPD_DYNAMIC_FILE_READ */
+/*-----------------------------------------------------------------------------------*/
+#if LWIP_HTTPD_FS_ASYNC_READ
+int
+fs_is_file_ready(struct fs_file *file, fs_wait_cb callback_fn, void *callback_arg)
+{
+  if (file != NULL) {
+#if LWIP_HTTPD_FS_ASYNC_READ
+#if LWIP_HTTPD_CUSTOM_FILES
+    if (!fs_canread_custom(file)) {
+      if (fs_wait_read_custom(file, callback_fn, callback_arg)) {
+        return 0;
+      }
+    }
+#else /* LWIP_HTTPD_CUSTOM_FILES */
+    LWIP_UNUSED_ARG(callback_fn);
+    LWIP_UNUSED_ARG(callback_arg);
+#endif /* LWIP_HTTPD_CUSTOM_FILES */
+#endif /* LWIP_HTTPD_FS_ASYNC_READ */
+  }
+  return 1;
+}
+#endif /* LWIP_HTTPD_FS_ASYNC_READ */
+/*-----------------------------------------------------------------------------------*/
+int
+fs_bytes_left(struct fs_file *file)
+{
+  return file->len - file->index;
+}

ext/lwip/src/apps/httpd/fs/404.html

@@ -0,0 +1,21 @@
+<html>
+<head><title>lwIP - A Lightweight TCP/IP Stack</title></head>
+<body bgcolor="white" text="black">
+
+    <table width="100%">
+      <tr valign="top"><td width="80">	  
+	  <a href="http://www.sics.se/"><img src="/img/sics.gif"
+	  border="0" alt="SICS logo" title="SICS logo"></a>
+	</td><td width="500">	  
+	  <h1>lwIP - A Lightweight TCP/IP Stack</h1>
+	  <h2>404 - Page not found</h2>
+	  <p>
+	    Sorry, the page you are requesting was not found on this
+	    server. 
+	  </p>
+	</td><td>
+	  &nbsp;
+	</td></tr>
+      </table>
+</body>
+</html>

ext/lwip/src/apps/httpd/fs/index.html

@@ -0,0 +1,47 @@
+<html>
+<head><title>lwIP - A Lightweight TCP/IP Stack</title></head>
+<body bgcolor="white" text="black">
+
+    <table width="100%">
+      <tr valign="top"><td width="80">	  
+	  <a href="http://www.sics.se/"><img src="/img/sics.gif"
+	  border="0" alt="SICS logo" title="SICS logo"></a>
+	</td><td width="500">	  
+	  <h1>lwIP - A Lightweight TCP/IP Stack</h1>
+	  <p>
+	    The web page you are watching was served by a simple web
+	    server running on top of the lightweight TCP/IP stack <a
+	    href="http://www.sics.se/~adam/lwip/">lwIP</a>.
+	  </p>
+	  <p>
+	    lwIP is an open source implementation of the TCP/IP
+	    protocol suite that was originally written by <a
+	    href="http://www.sics.se/~adam/lwip/">Adam Dunkels
+	    of the Swedish Institute of Computer Science</a> but now is
+	    being actively developed by a team of developers
+	    distributed world-wide. Since it's release, lwIP has
+	    spurred a lot of interest and has been ported to several
+	    platforms and operating systems. lwIP can be used either
+	    with or without an underlying OS.
+	  </p>
+	  <p>
+	    The focus of the lwIP TCP/IP implementation is to reduce
+	    the RAM usage while still having a full scale TCP. This
+	    makes lwIP suitable for use in embedded systems with tens
+	    of kilobytes of free RAM and room for around 40 kilobytes
+	    of code ROM.
+	  </p>
+	  <p>
+	    More information about lwIP can be found at the lwIP
+	    homepage at <a
+	    href="http://savannah.nongnu.org/projects/lwip/">http://savannah.nongnu.org/projects/lwip/</a>
+	    or at the lwIP wiki at <a
+	    href="http://lwip.wikia.com/">http://lwip.wikia.com/</a>.
+	  </p>
+	</td><td>
+	  &nbsp;
+	</td></tr>
+      </table>
+</body>
+</html>
+

ext/lwip/src/apps/httpd/fsdata.c

@@ -0,0 +1,298 @@
+#include "lwip/apps/fs.h"
+#include "lwip/def.h"
+#include "fsdata.h"
+
+
+#define file_NULL (struct fsdata_file *) NULL
+
+
+static const unsigned int dummy_align__img_sics_gif = 0;
+static const unsigned char data__img_sics_gif[] = {
+/* /img/sics.gif (14 chars) */
+0x2f,0x69,0x6d,0x67,0x2f,0x73,0x69,0x63,0x73,0x2e,0x67,0x69,0x66,0x00,0x00,0x00,
+
+/* HTTP header */
+/* "HTTP/1.0 200 OK
+" (17 bytes) */
+0x48,0x54,0x54,0x50,0x2f,0x31,0x2e,0x30,0x20,0x32,0x30,0x30,0x20,0x4f,0x4b,0x0d,
+0x0a,
+/* "Server: lwIP/1.3.1 (http://savannah.nongnu.org/projects/lwip)
+" (63 bytes) */
+0x53,0x65,0x72,0x76,0x65,0x72,0x3a,0x20,0x6c,0x77,0x49,0x50,0x2f,0x31,0x2e,0x33,
+0x2e,0x31,0x20,0x28,0x68,0x74,0x74,0x70,0x3a,0x2f,0x2f,0x73,0x61,0x76,0x61,0x6e,
+0x6e,0x61,0x68,0x2e,0x6e,0x6f,0x6e,0x67,0x6e,0x75,0x2e,0x6f,0x72,0x67,0x2f,0x70,
+0x72,0x6f,0x6a,0x65,0x63,0x74,0x73,0x2f,0x6c,0x77,0x69,0x70,0x29,0x0d,0x0a,
+/* "Content-type: image/gif
+
+" (27 bytes) */
+0x43,0x6f,0x6e,0x74,0x65,0x6e,0x74,0x2d,0x74,0x79,0x70,0x65,0x3a,0x20,0x69,0x6d,
+0x61,0x67,0x65,0x2f,0x67,0x69,0x66,0x0d,0x0a,0x0d,0x0a,
+/* raw file data (724 bytes) */
+0x47,0x49,0x46,0x38,0x39,0x61,0x46,0x00,0x22,0x00,0xa5,0x00,0x00,0xd9,0x2b,0x39,
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+0xa6,0xa6,0x80,0x80,0x80,0x76,0x76,0x76,0x1e,0x1e,0x1e,0x9d,0x9d,0x9d,0x2e,0x2e,
+0x2e,0x49,0x49,0x49,0x54,0x54,0x54,0x8a,0x8a,0x8a,0x60,0x60,0x60,0xc6,0xa6,0x99,
+0xbd,0xb5,0xb2,0xc2,0xab,0xa1,0xd9,0x41,0x40,0xd5,0x67,0x55,0xc0,0xb0,0xaa,0xd5,
+0x5e,0x4e,0xd6,0x50,0x45,0xcc,0x93,0x7d,0xc8,0xa1,0x90,0xce,0x8b,0x76,0xd2,0x7b,
+0x65,0xd1,0x84,0x6d,0xc9,0x99,0x86,0x3a,0x3a,0x3a,0x00,0x00,0x00,0xb8,0xb8,0xb8,
+0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,
+0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0xff,0x2c,0x00,0x00,
+0x00,0x00,0x46,0x00,0x22,0x00,0x00,0x06,0xfe,0x40,0x90,0x70,0x48,0x2c,0x1a,0x8f,
+0xc8,0xa4,0x72,0xc9,0x6c,0x3a,0x9f,0xd0,0xa8,0x74,0x4a,0xad,0x5a,0xaf,0xd8,0xac,
+0x76,0xa9,0x40,0x04,0xbe,0x83,0xe2,0x60,0x3c,0x50,0x20,0x0d,0x8e,0x6f,0x00,0x31,
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+0x41,0x00,0x00,0x3b,};
+
+static const unsigned int dummy_align__404_html = 1;
+static const unsigned char data__404_html[] = {
+/* /404.html (10 chars) */
+0x2f,0x34,0x30,0x34,0x2e,0x68,0x74,0x6d,0x6c,0x00,0x00,0x00,
+
+/* HTTP header */
+/* "HTTP/1.0 404 File not found
+" (29 bytes) */
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+/* "Server: lwIP/1.3.1 (http://savannah.nongnu.org/projects/lwip)
+" (63 bytes) */
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+/* "Content-type: text/html
+
+" (27 bytes) */
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+/* raw file data (565 bytes) */
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+
+static const unsigned int dummy_align__index_html = 2;
+static const unsigned char data__index_html[] = {
+/* /index.html (12 chars) */
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+
+/* HTTP header */
+/* "HTTP/1.0 200 OK
+" (17 bytes) */
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+0x0a,
+/* "Server: lwIP/1.3.1 (http://savannah.nongnu.org/projects/lwip)
+" (63 bytes) */
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+/* "Content-type: text/html
+
+" (27 bytes) */
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+
+
+
+const struct fsdata_file file__img_sics_gif[] = { {
+file_NULL,
+data__img_sics_gif,
+data__img_sics_gif + 16,
+sizeof(data__img_sics_gif) - 16,
+1,
+}};
+
+const struct fsdata_file file__404_html[] = { {
+file__img_sics_gif,
+data__404_html,
+data__404_html + 12,
+sizeof(data__404_html) - 12,
+1,
+}};
+
+const struct fsdata_file file__index_html[] = { {
+file__404_html,
+data__index_html,
+data__index_html + 12,
+sizeof(data__index_html) - 12,
+1,
+}};
+
+#define FS_ROOT file__index_html
+#define FS_NUMFILES 3
+

ext/lwip/src/apps/httpd/fsdata.h

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2001-2003 Swedish Institute of Computer Science.
+ * All rights reserved. 
+ * 
+ * Redistribution and use in source and binary forms, with or without modification, 
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission. 
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT 
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ * 
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+#ifndef LWIP_FSDATA_H
+#define LWIP_FSDATA_H
+
+#include "lwip/apps/httpd_opts.h"
+#include "lwip/apps/fs.h"
+
+struct fsdata_file {
+  const struct fsdata_file *next;
+  const unsigned char *name;
+  const unsigned char *data;
+  int len;
+  u8_t flags;
+#if HTTPD_PRECALCULATED_CHECKSUM
+  u16_t chksum_count;
+  const struct fsdata_chksum *chksum;
+#endif /* HTTPD_PRECALCULATED_CHECKSUM */
+};
+
+#endif /* LWIP_FSDATA_H */

ext/lwip/src/apps/httpd/httpd_structs.h

@@ -0,0 +1,114 @@
+#ifndef LWIP_HTTPD_STRUCTS_H
+#define LWIP_HTTPD_STRUCTS_H
+
+#include "lwip/apps/httpd.h"
+
+#if LWIP_HTTPD_DYNAMIC_HEADERS
+/** This struct is used for a list of HTTP header strings for various
+ * filename extensions. */
+typedef struct
+{
+  const char *extension;
+  const char *content_type;
+} tHTTPHeader;
+
+/** A list of strings used in HTTP headers (see RFC 1945 HTTP/1.0 and
+ * RFC 2616 HTTP/1.1 for header field definitions) */
+static const char * const g_psHTTPHeaderStrings[] =
+{
+ "HTTP/1.0 200 OK\r\n",
+ "HTTP/1.0 404 File not found\r\n",
+ "HTTP/1.0 400 Bad Request\r\n",
+ "HTTP/1.0 501 Not Implemented\r\n",
+ "HTTP/1.1 200 OK\r\n",
+ "HTTP/1.1 404 File not found\r\n",
+ "HTTP/1.1 400 Bad Request\r\n",
+ "HTTP/1.1 501 Not Implemented\r\n",
+ "Content-Length: ",
+ "Connection: Close\r\n",
+ "Connection: keep-alive\r\n",
+ "Connection: keep-alive\r\nContent-Length: ",
+ "Server: "HTTPD_SERVER_AGENT"\r\n",
+ "\r\n<html><body><h2>404: The requested file cannot be found.</h2></body></html>\r\n"
+#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
+ ,"Connection: keep-alive\r\nContent-Length: 77\r\n\r\n<html><body><h2>404: The requested file cannot be found.</h2></body></html>\r\n"
+#endif
+};
+
+/* Indexes into the g_psHTTPHeaderStrings array */
+#define HTTP_HDR_OK             0 /* 200 OK */
+#define HTTP_HDR_NOT_FOUND      1 /* 404 File not found */
+#define HTTP_HDR_BAD_REQUEST    2 /* 400 Bad request */
+#define HTTP_HDR_NOT_IMPL       3 /* 501 Not Implemented */
+#define HTTP_HDR_OK_11          4 /* 200 OK */
+#define HTTP_HDR_NOT_FOUND_11   5 /* 404 File not found */
+#define HTTP_HDR_BAD_REQUEST_11 6 /* 400 Bad request */
+#define HTTP_HDR_NOT_IMPL_11    7 /* 501 Not Implemented */
+#define HTTP_HDR_CONTENT_LENGTH 8 /* Content-Length: (HTTP 1.0)*/
+#define HTTP_HDR_CONN_CLOSE     9 /* Connection: Close (HTTP 1.1) */
+#define HTTP_HDR_CONN_KEEPALIVE 10 /* Connection: keep-alive (HTTP 1.1) */
+#define HTTP_HDR_KEEPALIVE_LEN  11 /* Connection: keep-alive + Content-Length: (HTTP 1.1)*/
+#define HTTP_HDR_SERVER         12 /* Server: HTTPD_SERVER_AGENT */
+#define DEFAULT_404_HTML        13 /* default 404 body */
+#if LWIP_HTTPD_SUPPORT_11_KEEPALIVE
+#define DEFAULT_404_HTML_PERSISTENT 14 /* default 404 body, but including Connection: keep-alive */
+#endif
+
+
+#define HTTP_HDR_HTML           "Content-type: text/html\r\n\r\n"
+#define HTTP_HDR_SSI            "Content-type: text/html\r\nExpires: Fri, 10 Apr 2008 14:00:00 GMT\r\nPragma: no-cache\r\n\r\n"
+#define HTTP_HDR_GIF            "Content-type: image/gif\r\n\r\n"
+#define HTTP_HDR_PNG            "Content-type: image/png\r\n\r\n"
+#define HTTP_HDR_JPG            "Content-type: image/jpeg\r\n\r\n"
+#define HTTP_HDR_BMP            "Content-type: image/bmp\r\n\r\n"
+#define HTTP_HDR_ICO            "Content-type: image/x-icon\r\n\r\n"
+#define HTTP_HDR_APP            "Content-type: application/octet-stream\r\n\r\n"
+#define HTTP_HDR_JS             "Content-type: application/javascript\r\n\r\n"
+#define HTTP_HDR_RA             "Content-type: application/javascript\r\n\r\n"
+#define HTTP_HDR_CSS            "Content-type: text/css\r\n\r\n"
+#define HTTP_HDR_SWF            "Content-type: application/x-shockwave-flash\r\n\r\n"
+#define HTTP_HDR_XML            "Content-type: text/xml\r\n\r\n"
+#define HTTP_HDR_PDF            "Content-type: application/pdf\r\n\r\n"
+#define HTTP_HDR_JSON           "Content-type: application/json\r\n\r\n"
+
+#define HTTP_HDR_DEFAULT_TYPE   "Content-type: text/plain\r\n\r\n"
+
+/** A list of extension-to-HTTP header strings (see outdated RFC 1700 MEDIA TYPES
+ * and http://www.iana.org/assignments/media-types for registered content types
+ * and subtypes) */
+static const tHTTPHeader g_psHTTPHeaders[] =
+{
+ { "html", HTTP_HDR_HTML},
+ { "htm",  HTTP_HDR_HTML},
+ { "shtml",HTTP_HDR_SSI},
+ { "shtm", HTTP_HDR_SSI},
+ { "ssi",  HTTP_HDR_SSI},
+ { "gif",  HTTP_HDR_GIF},
+ { "png",  HTTP_HDR_PNG},
+ { "jpg",  HTTP_HDR_JPG},
+ { "bmp",  HTTP_HDR_BMP},
+ { "ico",  HTTP_HDR_ICO},
+ { "class",HTTP_HDR_APP},
+ { "cls",  HTTP_HDR_APP},
+ { "js",   HTTP_HDR_JS},
+ { "ram",  HTTP_HDR_RA},
+ { "css",  HTTP_HDR_CSS},
+ { "swf",  HTTP_HDR_SWF},
+ { "xml",  HTTP_HDR_XML},
+ { "xsl",  HTTP_HDR_XML},
+ { "pdf",  HTTP_HDR_PDF},
+ { "json", HTTP_HDR_JSON}
+};
+
+#define NUM_HTTP_HEADERS (sizeof(g_psHTTPHeaders) / sizeof(tHTTPHeader))
+
+#endif /* LWIP_HTTPD_DYNAMIC_HEADERS */
+
+#if LWIP_HTTPD_SSI
+static const char * const g_pcSSIExtensions[] = {
+  ".shtml", ".shtm", ".ssi", ".xml"
+};
+#define NUM_SHTML_EXTENSIONS (sizeof(g_pcSSIExtensions) / sizeof(const char *))
+#endif /* LWIP_HTTPD_SSI */
+
+#endif /* LWIP_HTTPD_STRUCTS_H */

ext/lwip/src/apps/httpd/makefsdata/makefsdata

@@ -0,0 +1,97 @@
+#!/usr/bin/perl
+
+open(OUTPUT, "> fsdata.c");
+
+chdir("fs");
+open(FILES, "find . -type f |");
+
+while($file = <FILES>) {
+
+    # Do not include files in CVS directories nor backup files.
+    if($file =~ /(CVS|~)/) {
+    	next;
+    }
+    
+    chop($file);
+    
+    open(HEADER, "> /tmp/header") || die $!;
+    if($file =~ /404/) {
+	print(HEADER "HTTP/1.0 404 File not found\r\n");
+    } else {
+	print(HEADER "HTTP/1.0 200 OK\r\n");
+    }
+    print(HEADER "Server: lwIP/pre-0.6 (http://www.sics.se/~adam/lwip/)\r\n");
+    if($file =~ /\.html$/) {
+	print(HEADER "Content-type: text/html\r\n");
+    } elsif($file =~ /\.gif$/) {
+	print(HEADER "Content-type: image/gif\r\n");
+    } elsif($file =~ /\.png$/) {
+	print(HEADER "Content-type: image/png\r\n");
+    } elsif($file =~ /\.jpg$/) {
+	print(HEADER "Content-type: image/jpeg\r\n");
+    } elsif($file =~ /\.class$/) {
+	print(HEADER "Content-type: application/octet-stream\r\n");
+    } elsif($file =~ /\.ram$/) {
+	print(HEADER "Content-type: audio/x-pn-realaudio\r\n");    
+    } else {
+	print(HEADER "Content-type: text/plain\r\n");
+    }
+    print(HEADER "\r\n");
+    close(HEADER);
+
+    unless($file =~ /\.plain$/ || $file =~ /cgi/) {
+	system("cat /tmp/header $file > /tmp/file");
+    } else {
+	system("cp $file /tmp/file");
+    }
+    
+    open(FILE, "/tmp/file");
+    unlink("/tmp/file");
+    unlink("/tmp/header");
+
+    $file =~ s/\.//;
+    $fvar = $file;
+    $fvar =~ s-/-_-g;
+    $fvar =~ s-\.-_-g;
+    print(OUTPUT "static const unsigned char data".$fvar."[] = {\n");
+    print(OUTPUT "\t/* $file */\n\t");
+    for($j = 0; $j < length($file); $j++) {
+	printf(OUTPUT "%#02x, ", unpack("C", substr($file, $j, 1)));
+    }
+    printf(OUTPUT "0,\n");
+    
+    
+    $i = 0;
+    while(read(FILE, $data, 1)) {
+        if($i == 0) {
+            print(OUTPUT "\t");
+        }
+        printf(OUTPUT "%#02x, ", unpack("C", $data));
+        $i++;
+        if($i == 10) {
+            print(OUTPUT "\n");
+            $i = 0;
+        }
+    }
+    print(OUTPUT "};\n\n");
+    close(FILE);
+    push(@fvars, $fvar);
+    push(@files, $file);
+}
+
+for($i = 0; $i < @fvars; $i++) {
+    $file = $files[$i];
+    $fvar = $fvars[$i];
+
+    if($i == 0) {
+        $prevfile = "NULL";
+    } else {
+        $prevfile = "file" . $fvars[$i - 1];
+    }
+    print(OUTPUT "const struct fsdata_file file".$fvar."[] = {{$prevfile, data$fvar, ");
+    print(OUTPUT "data$fvar + ". (length($file) + 1) .", ");
+    print(OUTPUT "sizeof(data$fvar) - ". (length($file) + 1) ."}};\n\n");
+}
+
+print(OUTPUT "#define FS_ROOT file$fvars[$i - 1]\n\n");
+print(OUTPUT "#define FS_NUMFILES $i\n");

ext/lwip/src/apps/httpd/makefsdata/readme.txt

@@ -0,0 +1,13 @@
+This directory contains a script ('makefsdata') to create C code suitable for
+httpd for given html pages (or other files) in a directory.
+
+There is also a plain C console application doing the same and extended a bit.
+
+Usage: htmlgen [targetdir] [-s] [-i]s
+   targetdir: relative or absolute path to files to convert
+   switch -s: toggle processing of subdirectories (default is on)
+   switch -e: exclude HTTP header from file (header is created at runtime, default is on)
+   switch -11: include HTTP 1.1 header (1.0 is default)
+
+  if targetdir not specified, makefsdata will attempt to
+  process files in subdirectory 'fs'.

ext/lwip/src/apps/lwiperf/lwiperf.c

@@ -0,0 +1,662 @@
+/**
+ * @file
+ * lwIP iPerf server implementation
+ */
+
+/**
+ * @defgroup iperf Iperf server
+ * @ingroup apps
+ *
+ * This is a simple performance measuring server to check your bandwith using
+ * iPerf2 on a PC as client.
+ * It is currently a minimal implementation providing an IPv4 TCP server only.
+ *
+ * @todo: implement UDP mode and IPv6
+ */
+
+/*
+ * Copyright (c) 2014 Simon Goldschmidt
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Simon Goldschmidt
+ */
+
+#include "lwip/apps/lwiperf.h"
+
+#include "lwip/tcp.h"
+#include "lwip/sys.h"
+
+#include <string.h>
+
+/* Currently, only TCP-over-IPv4 is implemented (does iperf support IPv6 anyway?) */
+#if LWIP_IPV4 && LWIP_TCP
+
+/** Specify the idle timeout (in seconds) after that the test fails */
+#ifndef LWIPERF_TCP_MAX_IDLE_SEC
+#define LWIPERF_TCP_MAX_IDLE_SEC    10U
+#endif
+#if LWIPERF_TCP_MAX_IDLE_SEC > 255
+#error LWIPERF_TCP_MAX_IDLE_SEC must fit into an u8_t
+#endif
+
+/* File internal memory allocation (struct lwiperf_*): this defaults to
+   the heap */
+#ifndef LWIPERF_ALLOC
+#define LWIPERF_ALLOC(type)         mem_malloc(sizeof(type))
+#define LWIPERF_FREE(type, item)    mem_free(item)
+#endif
+
+/** If this is 1, check that received data has the correct format */
+#ifndef LWIPERF_CHECK_RX_DATA
+#define LWIPERF_CHECK_RX_DATA       0
+#endif
+
+/** This is the Iperf settings struct sent from the client */
+typedef struct _lwiperf_settings {
+#define LWIPERF_FLAGS_ANSWER_TEST 0x80000000
+#define LWIPERF_FLAGS_ANSWER_NOW  0x00000001
+  u32_t flags;
+  u32_t num_threads; /* unused for now */
+  u32_t remote_port;
+  u32_t buffer_len; /* unused for now */
+  u32_t win_band; /* TCP window / UDP rate: unused for now */
+  u32_t amount; /* pos. value: bytes?; neg. values: time (unit is 10ms: 1/100 second) */
+} lwiperf_settings_t;
+
+/** Basic connection handle */
+struct _lwiperf_state_base;
+typedef struct _lwiperf_state_base lwiperf_state_base_t;
+struct _lwiperf_state_base {
+  /* 1=tcp, 0=udp */
+  u8_t tcp;
+  /* 1=server, 0=client */
+  u8_t server;
+  lwiperf_state_base_t* next;
+  lwiperf_state_base_t* related_server_state;
+};
+
+/** Connection handle for a TCP iperf session */
+typedef struct _lwiperf_state_tcp {
+  lwiperf_state_base_t base;
+  struct tcp_pcb* server_pcb;
+  struct tcp_pcb* conn_pcb;
+  u32_t time_started;
+  lwiperf_report_fn report_fn;
+  void* report_arg;
+  u8_t poll_count;
+  u8_t next_num;
+  u32_t bytes_transferred;
+  lwiperf_settings_t settings;
+  u8_t have_settings_buf;
+} lwiperf_state_tcp_t;
+
+/** List of active iperf sessions */
+static lwiperf_state_base_t* lwiperf_all_connections;
+/** A const buffer to send from: we want to measure sending, not copying! */
+static const u8_t lwiperf_txbuf_const[1600] = {
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+  '0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9','0','1','2','3','4','5','6','7','8','9',
+};
+
+static err_t lwiperf_tcp_poll(void *arg, struct tcp_pcb *tpcb);
+static void lwiperf_tcp_err(void *arg, err_t err);
+
+/** Add an iperf session to the 'active' list */
+static void
+lwiperf_list_add(lwiperf_state_base_t* item)
+{
+  if (lwiperf_all_connections == NULL) {
+    lwiperf_all_connections = item;
+  } else {
+    item = lwiperf_all_connections;
+  }
+}
+
+/** Remove an iperf session from the 'active' list */
+static void
+lwiperf_list_remove(lwiperf_state_base_t* item)
+{
+  lwiperf_state_base_t* prev = NULL;
+  lwiperf_state_base_t* iter;
+  for (iter = lwiperf_all_connections; iter != NULL; prev = iter, iter = iter->next) {
+    if (iter == item) {
+      if (prev == NULL) {
+        lwiperf_all_connections = iter->next;
+      } else {
+        prev->next = item;
+      }
+      /* @debug: ensure this item is listed only once */
+      for (iter = iter->next; iter != NULL; iter = iter->next) {
+        LWIP_ASSERT("duplicate entry", iter != item);
+      }
+      break;
+    }
+  }
+}
+
+/** Call the report function of an iperf tcp session */
+static void
+lwip_tcp_conn_report(lwiperf_state_tcp_t* conn, enum lwiperf_report_type report_type)
+{
+  if ((conn != NULL) && (conn->report_fn != NULL)) {
+    u32_t now, duration_ms, bandwidth_kbitpsec;
+    now = sys_now();
+    duration_ms = now - conn->time_started;
+    if (duration_ms == 0) {
+      bandwidth_kbitpsec = 0;
+    } else {
+      bandwidth_kbitpsec = (conn->bytes_transferred / duration_ms) * 8U;
+    }
+    conn->report_fn(conn->report_arg, report_type,
+      &conn->conn_pcb->local_ip, conn->conn_pcb->local_port,
+      &conn->conn_pcb->remote_ip, conn->conn_pcb->remote_port,
+      conn->bytes_transferred, duration_ms, bandwidth_kbitpsec);
+  }
+}
+
+/** Close an iperf tcp session */
+static void
+lwiperf_tcp_close(lwiperf_state_tcp_t* conn, enum lwiperf_report_type report_type)
+{
+  err_t err;
+
+  lwip_tcp_conn_report(conn, report_type);
+  lwiperf_list_remove(&conn->base);
+  if (conn->conn_pcb != NULL) {
+    tcp_arg(conn->conn_pcb, NULL);
+    tcp_poll(conn->conn_pcb, NULL, 0);
+    tcp_sent(conn->conn_pcb, NULL);
+    tcp_recv(conn->conn_pcb, NULL);
+    tcp_err(conn->conn_pcb, NULL);
+    err = tcp_close(conn->conn_pcb);
+    if (err != ERR_OK) {
+      /* don't want to wait for free memory here... */
+      tcp_abort(conn->conn_pcb);
+    }
+  } else {
+    /* no conn pcb, this is the server pcb */
+    err = tcp_close(conn->server_pcb);
+    LWIP_ASSERT("error", err != ERR_OK);
+  }
+  LWIPERF_FREE(lwiperf_state_tcp_t, conn);
+}
+
+/** Try to send more data on an iperf tcp session */
+static err_t
+lwiperf_tcp_client_send_more(lwiperf_state_tcp_t* conn)
+{
+  int send_more;
+  err_t err;
+  u16_t txlen;
+  u16_t txlen_max;
+  void* txptr;
+  u8_t apiflags;
+
+  LWIP_ASSERT("conn invalid", (conn != NULL) && conn->base.tcp && (conn->base.server == 0));
+
+  do {
+    send_more = 0;
+    if (conn->settings.amount & PP_HTONL(0x80000000)) {
+      /* this session is time-limited */
+      u32_t now = sys_now();
+      u32_t diff_ms = now - conn->time_started;
+      u32_t time = (u32_t)-(s32_t)htonl(conn->settings.amount);
+      u32_t time_ms = time * 10;
+      if (diff_ms >= time_ms) {
+        /* time specified by the client is over -> close the connection */
+        lwiperf_tcp_close(conn, LWIPERF_TCP_DONE_CLIENT);
+        return ERR_OK;
+      }
+    } else {
+      /* this session is byte-limited */
+      u32_t amount_bytes = htonl(conn->settings.amount);
+      /* @todo: this can send up to 1*MSS more than requested... */
+      if (amount_bytes >= conn->bytes_transferred) {
+        /* all requested bytes transferred -> close the connection */
+        lwiperf_tcp_close(conn, LWIPERF_TCP_DONE_CLIENT);
+        return ERR_OK;
+      }
+    }
+
+    if (conn->bytes_transferred < 24) {
+      /* transmit the settings a first time */
+      txptr = &((u8_t*)&conn->settings)[conn->bytes_transferred];
+      txlen_max = (u16_t)(24 - conn->bytes_transferred);
+      apiflags = TCP_WRITE_FLAG_COPY;
+    } else if (conn->bytes_transferred < 48) {
+      /* transmit the settings a second time */
+      txptr = &((u8_t*)&conn->settings)[conn->bytes_transferred - 24];
+      txlen_max = (u16_t)(48 - conn->bytes_transferred);
+      apiflags = TCP_WRITE_FLAG_COPY | TCP_WRITE_FLAG_MORE;
+      send_more = 1;
+    } else {
+      /* transmit data */
+      /* @todo: every x bytes, transmit the settings again */
+      txptr = (void*)(size_t)&lwiperf_txbuf_const[conn->bytes_transferred % 10];
+      txlen_max = TCP_MSS;
+      if (conn->bytes_transferred == 48) { /* @todo: fix this for intermediate settings, too */
+        txlen_max = TCP_MSS - 24;
+      }
+      apiflags = 0; /* no copying needed */
+      send_more = 1;
+    }
+    txlen = txlen_max;
+    do {
+      err = tcp_write(conn->conn_pcb, txptr, txlen, apiflags);
+      if (err ==  ERR_MEM) {
+        txlen /= 2;
+      }
+    } while ((err == ERR_MEM) && (txlen >= (TCP_MSS/2)));
+
+    if (err == ERR_OK) {
+      conn->bytes_transferred += txlen;
+    } else {
+      send_more = 0;
+    }
+  } while(send_more);
+
+  tcp_output(conn->conn_pcb);
+  return ERR_OK;
+}
+
+/** TCP sent callback, try to send more data */
+static err_t
+lwiperf_tcp_client_sent(void *arg, struct tcp_pcb *tpcb, u16_t len)
+{
+  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
+  /* @todo: check 'len' (e.g. to time ACK of all data)? for now, we just send more... */
+  LWIP_ASSERT("invalid conn", conn->conn_pcb == tpcb);
+  LWIP_UNUSED_ARG(tpcb);
+  LWIP_UNUSED_ARG(len);
+
+  conn->poll_count = 0;
+
+  return lwiperf_tcp_client_send_more(conn);
+}
+
+/** TCP connected callback (active connection), send data now */
+static err_t
+lwiperf_tcp_client_connected(void *arg, struct tcp_pcb *tpcb, err_t err)
+{
+  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
+  LWIP_ASSERT("invalid conn", conn->conn_pcb == tpcb);
+  LWIP_UNUSED_ARG(tpcb);
+  if (err != ERR_OK) {
+    lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_REMOTE);
+    return ERR_OK;
+  }
+  conn->poll_count = 0;
+  conn->time_started = sys_now();
+  return lwiperf_tcp_client_send_more(conn);
+}
+
+/** Start TCP connection back to the client (either parallel or after the
+ * receive test has finished.
+ */
+static err_t
+lwiperf_tx_start(lwiperf_state_tcp_t* conn)
+{
+  err_t err;
+  lwiperf_state_tcp_t* client_conn;
+  struct tcp_pcb* newpcb;
+  ip_addr_t remote_addr;
+  u16_t remote_port;
+
+  client_conn = (lwiperf_state_tcp_t*)LWIPERF_ALLOC(lwiperf_state_tcp_t);
+  if (client_conn == NULL) {
+    return ERR_MEM;
+  }
+  newpcb = tcp_new();
+  if (newpcb == NULL) {
+    LWIPERF_FREE(lwiperf_state_tcp_t, client_conn);
+    return ERR_MEM;
+  }
+
+  memcpy(client_conn, conn, sizeof(lwiperf_state_tcp_t));
+  client_conn->base.server = 0;
+  client_conn->server_pcb = NULL;
+  client_conn->conn_pcb = newpcb;
+  client_conn->time_started = sys_now(); /* @todo: set this again on 'connected' */
+  client_conn->poll_count = 0;
+  client_conn->next_num = 4; /* initial nr is '4' since the header has 24 byte */
+  client_conn->bytes_transferred = 0;
+  client_conn->settings.flags = 0; /* prevent the remote side starting back as client again */
+
+  tcp_arg(newpcb, client_conn);
+  tcp_sent(newpcb, lwiperf_tcp_client_sent);
+  tcp_poll(newpcb, lwiperf_tcp_poll, 2U);
+  tcp_err(newpcb, lwiperf_tcp_err);
+
+  ip_addr_copy(remote_addr, conn->conn_pcb->remote_ip);
+  remote_port = (u16_t)htonl(client_conn->settings.remote_port);
+
+  err = tcp_connect(newpcb, &remote_addr, remote_port, lwiperf_tcp_client_connected);
+  if (err != ERR_OK) {
+    lwiperf_tcp_close(client_conn, LWIPERF_TCP_ABORTED_LOCAL);
+    return err;
+  }
+  lwiperf_list_add(&client_conn->base);
+  return ERR_OK;
+}
+
+/** Receive data on an iperf tcp session */
+static err_t
+lwiperf_tcp_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
+{
+  u16_t tot_len;
+  u32_t packet_idx;
+  struct pbuf* q;
+  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
+
+  LWIP_ASSERT("pcb mismatch", conn->conn_pcb == tpcb);
+  LWIP_UNUSED_ARG(tpcb);
+
+  if (err != ERR_OK) {
+    lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_REMOTE);
+    return ERR_OK;
+  }
+  if (p == NULL) {
+    /* connection closed -> test done */
+    if ((conn->settings.flags & PP_HTONL(LWIPERF_FLAGS_ANSWER_TEST|LWIPERF_FLAGS_ANSWER_NOW)) ==
+        PP_HTONL(LWIPERF_FLAGS_ANSWER_TEST)) {
+      /* client requested transmission after end of test */
+      lwiperf_tx_start(conn);
+    }
+    lwiperf_tcp_close(conn, LWIPERF_TCP_DONE_SERVER);
+    return ERR_OK;
+  }
+  tot_len = p->tot_len;
+
+  conn->poll_count = 0;
+
+  if ((!conn->have_settings_buf) || ((conn->bytes_transferred -24) % (1024*128) == 0)) {
+    /* wait for 24-byte header */
+    if (p->tot_len < sizeof(lwiperf_settings_t)) {
+      lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL_DATAERROR);
+      pbuf_free(p);
+      return ERR_VAL;
+    }
+    if (!conn->have_settings_buf) {
+      if (pbuf_copy_partial(p, &conn->settings, sizeof(lwiperf_settings_t), 0) != sizeof(lwiperf_settings_t)) {
+        lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL);
+        pbuf_free(p);
+        return ERR_VAL;
+      }
+      conn->have_settings_buf = 1;
+      if ((conn->settings.flags & PP_HTONL(LWIPERF_FLAGS_ANSWER_TEST|LWIPERF_FLAGS_ANSWER_NOW)) ==
+        PP_HTONL(LWIPERF_FLAGS_ANSWER_TEST|LWIPERF_FLAGS_ANSWER_NOW)) {
+          /* client requested parallel transmission test */
+          err_t err2 = lwiperf_tx_start(conn);
+          if (err2 != ERR_OK) {
+            lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL_TXERROR);
+            pbuf_free(p);
+            return err2;
+          }
+      }
+    } else {
+      if (pbuf_memcmp(p, 0, &conn->settings, sizeof(lwiperf_settings_t)) != 0) {
+        lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL_DATAERROR);
+        pbuf_free(p);
+        return ERR_VAL;
+      }
+    }
+    conn->bytes_transferred += sizeof(lwiperf_settings_t);
+    if (conn->bytes_transferred <= 24) {
+      conn->time_started = sys_now();
+      tcp_recved(tpcb, p->tot_len);
+      pbuf_free(p);
+      return ERR_OK;
+    }
+    conn->next_num = 4; /* 24 bytes received... */
+    err = pbuf_header(p, -24);
+    LWIP_ASSERT("pbuf_header failed", err == ERR_OK);
+  }
+
+  packet_idx = 0;
+  for (q = p; q != NULL; q = q->next) {
+#if LWIPERF_CHECK_RX_DATA
+    const u8_t* payload = (const u8_t*)q->payload;
+    u16_t i;
+    for (i = 0; i < q->len; i++) {
+      u8_t val = payload[i];
+      u8_t num = val - '0';
+      if (num == conn->next_num) {
+        conn->next_num++;
+        if (conn->next_num == 10) {
+          conn->next_num = 0;
+        }
+      } else {
+        lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL_DATAERROR);
+        pbuf_free(p);
+        return ERR_VAL;
+      }
+    }
+    packet_idx += i;
+#else
+    packet_idx += q->len;
+#endif
+  }
+  LWIP_ASSERT("count mismatch", packet_idx == p->tot_len);
+  conn->bytes_transferred += packet_idx;
+  tcp_recved(tpcb, tot_len);
+  pbuf_free(p);
+  return ERR_OK;
+}
+
+/** Error callback, iperf tcp session aborted */
+static void
+lwiperf_tcp_err(void *arg, err_t err)
+{
+  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
+  LWIP_UNUSED_ARG(err);
+  lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_REMOTE);
+}
+
+/** TCP poll callback, try to send more data */
+static err_t
+lwiperf_tcp_poll(void *arg, struct tcp_pcb *tpcb)
+{
+  lwiperf_state_tcp_t* conn = (lwiperf_state_tcp_t*)arg;
+  LWIP_ASSERT("pcb mismatch", conn->conn_pcb == tpcb);
+  LWIP_UNUSED_ARG(tpcb);
+  if (++conn->poll_count >= LWIPERF_TCP_MAX_IDLE_SEC) {
+    lwiperf_tcp_close(conn, LWIPERF_TCP_ABORTED_LOCAL);
+    return ERR_OK; /* lwiperf_tcp_close frees conn */
+  }
+
+  if (!conn->base.server) {
+    lwiperf_tcp_client_send_more(conn);
+  }
+
+  return ERR_OK;
+}
+
+/** This is called when a new client connects for an iperf tcp session */
+static err_t
+lwiperf_tcp_accept(void *arg, struct tcp_pcb *newpcb, err_t err)
+{
+  lwiperf_state_tcp_t *s, *conn;
+  if ((err != ERR_OK) || (newpcb == NULL) || (arg == NULL)) {
+    return ERR_VAL;
+  }
+
+  s = (lwiperf_state_tcp_t*)arg;
+  conn = (lwiperf_state_tcp_t*)LWIPERF_ALLOC(lwiperf_state_tcp_t);
+  if (conn == NULL) {
+    return ERR_MEM;
+  }
+  memset(conn, 0, sizeof(lwiperf_state_tcp_t));
+  conn->base.tcp = 1;
+  conn->base.server = 1;
+  conn->base.related_server_state = &s->base;
+  conn->server_pcb = s->server_pcb;
+  conn->conn_pcb = newpcb;
+  conn->time_started = sys_now();
+  conn->report_fn = s->report_fn;
+  conn->report_arg = s->report_arg;
+
+  /* setup the tcp rx connection */
+  tcp_arg(newpcb, conn);
+  tcp_recv(newpcb, lwiperf_tcp_recv);
+  tcp_poll(newpcb, lwiperf_tcp_poll, 2U);
+  tcp_err(conn->conn_pcb, lwiperf_tcp_err);
+
+  lwiperf_list_add(&conn->base);
+  return ERR_OK;
+}
+
+/** 
+ * @ingroup iperf
+ * Start a TCP iperf server on the default TCP port (5001) and listen for
+ * incoming connections from iperf clients.
+ *
+ * @returns a connection handle that can be used to abort the server
+ *          by calling @ref lwiperf_abort()
+ */
+void*
+lwiperf_start_tcp_server_default(lwiperf_report_fn report_fn, void* report_arg)
+{
+  return lwiperf_start_tcp_server(IP_ADDR_ANY, LWIPERF_TCP_PORT_DEFAULT,
+    report_fn, report_arg);
+}
+
+/**
+ * @ingroup iperf
+ * Start a TCP iperf server on a specific IP address and port and listen for
+ * incoming connections from iperf clients.
+ *
+ * @returns a connection handle that can be used to abort the server
+ *          by calling @ref lwiperf_abort()
+ */
+void*
+lwiperf_start_tcp_server(const ip_addr_t* local_addr, u16_t local_port,
+  lwiperf_report_fn report_fn, void* report_arg)
+{
+  err_t err;
+  struct tcp_pcb* pcb;
+  lwiperf_state_tcp_t* s;
+
+  if (local_addr == NULL) {
+    return NULL;
+  }
+
+  s = (lwiperf_state_tcp_t*)LWIPERF_ALLOC(lwiperf_state_tcp_t);
+  if (s == NULL) {
+    return NULL;
+  }
+  memset(s, 0, sizeof(lwiperf_state_tcp_t));
+  s->base.tcp = 1;
+  s->base.server = 1;
+  s->report_fn = report_fn;
+  s->report_arg = report_arg;
+
+  pcb = tcp_new();
+  if (pcb != NULL) {
+    err = tcp_bind(pcb, local_addr, local_port);
+    if (err == ERR_OK) {
+      s->server_pcb = tcp_listen_with_backlog(pcb, 1);
+    }
+  }
+  if (s->server_pcb == NULL) {
+    if (pcb != NULL) {
+      tcp_close(pcb);
+    }
+    LWIPERF_FREE(lwiperf_state_tcp_t, s);
+    return NULL;
+  }
+  pcb = NULL;
+
+  tcp_arg(s->server_pcb, s);
+  tcp_accept(s->server_pcb, lwiperf_tcp_accept);
+
+  lwiperf_list_add(&s->base);
+  return s;
+}
+
+/**
+ * @ingroup iperf
+ * Abort an iperf session (handle returned by lwiperf_start_tcp_server*())
+ */
+void
+lwiperf_abort(void* lwiperf_session)
+{
+  lwiperf_state_base_t* i, *dealloc, *last = NULL;
+
+  for (i = lwiperf_all_connections; i != NULL; ) {
+    if ((i == lwiperf_session) || (i->related_server_state == lwiperf_session)) {
+      dealloc = i;
+      i = i->next;
+      if (last != NULL) {
+        last->next = i;
+      }
+      LWIPERF_FREE(lwiperf_state_tcp_t, dealloc); /* @todo: type? */
+    } else {
+      last = i;
+      i = i->next;
+    }
+  }
+}
+
+#endif /* LWIP_IPV4 && LWIP_TCP */

ext/lwip/src/apps/netbiosns/netbiosns.c

@@ -0,0 +1,366 @@
+/**
+ * @file
+ * NetBIOS name service responder
+ */
+
+/**
+ * @defgroup netbiosns NETBIOS responder
+ * @ingroup apps
+ *
+ * This is an example implementation of a NetBIOS name server.
+ * It responds to name queries for a configurable name.
+ * Name resolving is not supported.
+ *
+ * Note that the device doesn't broadcast it's own name so can't
+ * detect duplicate names!
+ */
+
+/*
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ */
+
+#include "lwip/apps/netbiosns.h"
+
+#if LWIP_IPV4 && LWIP_UDP  /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/udp.h"
+#include "lwip/netif.h"
+
+#include <string.h>
+
+/** default port number for "NetBIOS Name service */
+#define NETBIOS_PORT     137
+
+/** size of a NetBIOS name */
+#define NETBIOS_NAME_LEN 16
+
+/** The Time-To-Live for NetBIOS name responds (in seconds)
+ * Default is 300000 seconds (3 days, 11 hours, 20 minutes) */
+#define NETBIOS_NAME_TTL 300000u
+
+/** NetBIOS header flags */
+#define NETB_HFLAG_RESPONSE           0x8000U
+#define NETB_HFLAG_OPCODE             0x7800U
+#define NETB_HFLAG_OPCODE_NAME_QUERY  0x0000U
+#define NETB_HFLAG_AUTHORATIVE        0x0400U
+#define NETB_HFLAG_TRUNCATED          0x0200U
+#define NETB_HFLAG_RECURS_DESIRED     0x0100U
+#define NETB_HFLAG_RECURS_AVAILABLE   0x0080U
+#define NETB_HFLAG_BROADCAST          0x0010U
+#define NETB_HFLAG_REPLYCODE          0x0008U
+#define NETB_HFLAG_REPLYCODE_NOERROR  0x0000U
+
+/** NetBIOS name flags */
+#define NETB_NFLAG_UNIQUE             0x8000U
+#define NETB_NFLAG_NODETYPE           0x6000U
+#define NETB_NFLAG_NODETYPE_HNODE     0x6000U
+#define NETB_NFLAG_NODETYPE_MNODE     0x4000U
+#define NETB_NFLAG_NODETYPE_PNODE     0x2000U
+#define NETB_NFLAG_NODETYPE_BNODE     0x0000U
+
+/** NetBIOS message header */
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct netbios_hdr {
+  PACK_STRUCT_FIELD(u16_t trans_id);
+  PACK_STRUCT_FIELD(u16_t flags);
+  PACK_STRUCT_FIELD(u16_t questions);
+  PACK_STRUCT_FIELD(u16_t answerRRs);
+  PACK_STRUCT_FIELD(u16_t authorityRRs);
+  PACK_STRUCT_FIELD(u16_t additionalRRs);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+
+/** NetBIOS message name part */
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct netbios_name_hdr {
+  PACK_STRUCT_FLD_8(u8_t  nametype);
+  PACK_STRUCT_FLD_8(u8_t  encname[(NETBIOS_NAME_LEN*2)+1]);
+  PACK_STRUCT_FIELD(u16_t type);
+  PACK_STRUCT_FIELD(u16_t cls);
+  PACK_STRUCT_FIELD(u32_t ttl);
+  PACK_STRUCT_FIELD(u16_t datalen);
+  PACK_STRUCT_FIELD(u16_t flags);
+  PACK_STRUCT_FLD_S(ip4_addr_p_t addr);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+
+/** NetBIOS message */
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct netbios_resp
+{
+  struct netbios_hdr      resp_hdr;
+  struct netbios_name_hdr resp_name;
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+
+#ifdef NETBIOS_LWIP_NAME
+#define NETBIOS_LOCAL_NAME NETBIOS_LWIP_NAME
+#else
+static char netbiosns_local_name[NETBIOS_NAME_LEN];
+#define NETBIOS_LOCAL_NAME netbiosns_local_name
+#endif
+
+struct udp_pcb *netbiosns_pcb;
+
+/** Decode a NetBIOS name (from packet to string) */
+static int
+netbiosns_name_decode(char *name_enc, char *name_dec, int name_dec_len)
+{
+  char *pname;
+  char  cname;
+  char  cnbname;
+  int   idx = 0;
+
+  LWIP_UNUSED_ARG(name_dec_len);
+
+  /* Start decoding netbios name. */
+  pname  = name_enc;
+  for (;;) {
+    /* Every two characters of the first level-encoded name
+     * turn into one character in the decoded name. */
+    cname = *pname;
+    if (cname == '\0')
+      break;    /* no more characters */
+    if (cname == '.')
+      break;    /* scope ID follows */
+    if (cname < 'A' || cname > 'Z') {
+      /* Not legal. */
+      return -1;
+    }
+    cname -= 'A';
+    cnbname = cname << 4;
+    pname++;
+
+    cname = *pname;
+    if (cname == '\0' || cname == '.') {
+      /* No more characters in the name - but we're in
+       * the middle of a pair.  Not legal. */
+      return -1;
+    }
+    if (cname < 'A' || cname > 'Z') {
+      /* Not legal. */
+      return -1;
+    }
+    cname -= 'A';
+    cnbname |= cname;
+    pname++;
+
+    /* Do we have room to store the character? */
+    if (idx < NETBIOS_NAME_LEN) {
+      /* Yes - store the character. */
+      name_dec[idx++] = (cnbname!=' '?cnbname:'\0');
+    }
+  }
+
+  return 0;
+}
+
+#if 0 /* function currently unused */
+/** Encode a NetBIOS name (from string to packet) - currently unused because
+    we don't ask for names. */
+static int
+netbiosns_name_encode(char *name_enc, char *name_dec, int name_dec_len)
+{
+  char         *pname;
+  char          cname;
+  unsigned char ucname;
+  int           idx = 0;
+
+  /* Start encoding netbios name. */
+  pname = name_enc;
+
+  for (;;) {
+    /* Every two characters of the first level-encoded name
+     * turn into one character in the decoded name. */
+    cname = *pname;
+    if (cname == '\0')
+      break;    /* no more characters */
+    if (cname == '.')
+      break;    /* scope ID follows */
+    if ((cname < 'A' || cname > 'Z') && (cname < '0' || cname > '9')) {
+      /* Not legal. */
+      return -1;
+    }
+
+    /* Do we have room to store the character? */
+    if (idx >= name_dec_len) {
+      return -1;
+    }
+
+    /* Yes - store the character. */
+    ucname = cname;
+    name_dec[idx++] = ('A'+((ucname>>4) & 0x0F));
+    name_dec[idx++] = ('A'+( ucname     & 0x0F));
+    pname++;
+  }
+
+  /* Fill with "space" coding */
+  for (;idx < name_dec_len - 1;) {
+    name_dec[idx++] = 'C';
+    name_dec[idx++] = 'A';
+  }
+
+  /* Terminate string */
+  name_dec[idx] = '\0';
+
+  return 0;
+}
+#endif /* 0 */
+
+/** NetBIOS Name service recv callback */
+static void
+netbiosns_recv(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
+{
+  LWIP_UNUSED_ARG(arg);
+
+  /* if packet is valid */
+  if (p != NULL) {
+    char   netbios_name[NETBIOS_NAME_LEN+1];
+    struct netbios_hdr*      netbios_hdr      = (struct netbios_hdr*)p->payload;
+    struct netbios_name_hdr* netbios_name_hdr = (struct netbios_name_hdr*)(netbios_hdr+1);
+
+    /* we only answer if we got a default interface */
+    if (netif_default != NULL) {
+      /* @todo: do we need to check answerRRs/authorityRRs/additionalRRs? */
+      /* if the packet is a NetBIOS name query question */
+      if (((netbios_hdr->flags & PP_NTOHS(NETB_HFLAG_OPCODE)) == PP_NTOHS(NETB_HFLAG_OPCODE_NAME_QUERY)) &&
+          ((netbios_hdr->flags & PP_NTOHS(NETB_HFLAG_RESPONSE)) == 0) &&
+           (netbios_hdr->questions == PP_NTOHS(1))) {
+        /* decode the NetBIOS name */
+        netbiosns_name_decode((char*)(netbios_name_hdr->encname), netbios_name, sizeof(netbios_name));
+        /* if the packet is for us */
+        if (NETBIOS_STRCMP(netbios_name, NETBIOS_LOCAL_NAME) == 0) {
+          struct pbuf *q;
+          struct netbios_resp *resp;
+
+          q = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct netbios_resp), PBUF_RAM);
+          if (q != NULL) {
+            resp = (struct netbios_resp*)q->payload;
+
+            /* prepare NetBIOS header response */
+            resp->resp_hdr.trans_id      = netbios_hdr->trans_id;
+            resp->resp_hdr.flags         = PP_HTONS(NETB_HFLAG_RESPONSE |
+                                                 NETB_HFLAG_OPCODE_NAME_QUERY |
+                                                 NETB_HFLAG_AUTHORATIVE |
+                                                 NETB_HFLAG_RECURS_DESIRED);
+            resp->resp_hdr.questions     = 0;
+            resp->resp_hdr.answerRRs     = PP_HTONS(1);
+            resp->resp_hdr.authorityRRs  = 0;
+            resp->resp_hdr.additionalRRs = 0;
+
+            /* prepare NetBIOS header datas */
+            MEMCPY( resp->resp_name.encname, netbios_name_hdr->encname, sizeof(netbios_name_hdr->encname));
+            resp->resp_name.nametype     = netbios_name_hdr->nametype;
+            resp->resp_name.type         = netbios_name_hdr->type;
+            resp->resp_name.cls          = netbios_name_hdr->cls;
+            resp->resp_name.ttl          = PP_HTONL(NETBIOS_NAME_TTL);
+            resp->resp_name.datalen      = PP_HTONS(sizeof(resp->resp_name.flags)+sizeof(resp->resp_name.addr));
+            resp->resp_name.flags        = PP_HTONS(NETB_NFLAG_NODETYPE_BNODE);
+            ip4_addr_copy(resp->resp_name.addr, *netif_ip4_addr(netif_default));
+
+            /* send the NetBIOS response */
+            udp_sendto(upcb, q, addr, port);
+
+            /* free the "reference" pbuf */
+            pbuf_free(q);
+          }
+        }
+      }
+    }
+    /* free the pbuf */
+    pbuf_free(p);
+  }
+}
+
+/**
+ * @ingroup netbiosns 
+ * Init netbios responder
+ */
+void
+netbiosns_init(void)
+{
+#ifdef NETBIOS_LWIP_NAME
+  LWIP_ASSERT("NetBIOS name is too long!", strlen(NETBIOS_LWIP_NAME) < NETBIOS_NAME_LEN);
+#endif
+
+  netbiosns_pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
+  if (netbiosns_pcb != NULL) {
+    /* we have to be allowed to send broadcast packets! */
+    netbiosns_pcb->so_options |= SOF_BROADCAST;
+    udp_bind(netbiosns_pcb, IP_ANY_TYPE, NETBIOS_PORT);
+    udp_recv(netbiosns_pcb, netbiosns_recv, netbiosns_pcb);
+  }
+}
+
+#ifndef NETBIOS_LWIP_NAME
+/**
+ * @ingroup netbiosns 
+ * Set netbios name. ATTENTION: the hostname must be less than 15 characters!
+ */
+void
+netbiosns_set_name(const char* hostname)
+{
+  size_t copy_len = strlen(hostname);
+  LWIP_ASSERT("NetBIOS name is too long!", copy_len < NETBIOS_NAME_LEN);
+  if (copy_len >= NETBIOS_NAME_LEN) {
+    copy_len = NETBIOS_NAME_LEN - 1;
+  }
+  memcpy(netbiosns_local_name, hostname, copy_len + 1);
+}
+#endif
+
+/**
+ * @ingroup netbiosns 
+ * Stop netbios responder
+ */
+void
+netbiosns_stop(void)
+{
+  if (netbiosns_pcb != NULL) {
+    udp_remove(netbiosns_pcb);
+    netbiosns_pcb = NULL;
+  }
+}
+
+#endif /* LWIP_IPV4 && LWIP_UDP */

ext/lwip/src/apps/snmp/README

@@ -0,0 +1,38 @@
+lwIP SNMPv2c agent
+==================
+
+Based on SNMP stack written by Christiaan Simons <christiaan.simons@axon.tv>
+
+Rewritten by Martin Hentschel <info@cl-soft.de> and
+Dirk Ziegelmeier <dziegel@gmx.de>
+
+Features:
+  - SNMPv2c support.
+  - Low RAM usage - no memory pools, stack only.
+  - MIB2 implementation is separated from SNMP stack.
+  - Support for multiple MIBs (snmp_set_mibs() call) - e.g. for private MIB.
+  - Simple and generic API for MIB implementation.
+  - Comfortable node types and helper functions for scalar arrays and tables.
+  - Counter64, bit and truthvalue datatype support.
+  - Callbacks for SNMP writes e.g. to implement persistency.
+  - Runs on two APIs: RAW and netconn.
+  - Async API is gone - the stack now supports netconn API instead,
+    so blocking operations can be done in MIB calls.
+    SNMP runs in a worker thread when netconn API is used.
+  - Simplified thread sync support for MIBs - useful when MIBs
+    need to access variables shared with other threads where no locking is
+    possible. Used in MIB2 to access lwIP stats from lwIP thread.
+
+MIB compiler (code generator):
+  - Written in C#. MIB viewer used Windows Forms.
+  - Developed on Windows with Visual Studio 2010.
+  - Can be compiled and used under Linux with http://www.monodevelop.com/.
+  - Based on a heavily modified version of of SharpSnmpLib (a4bd05c6afb4)
+    (https://sharpsnmplib.codeplex.com/SourceControl/network/forks/Nemo157/MIBParserUpdate).
+  - MIB parser, C file generation framework and LWIP code generation are cleanly
+    separated, which means the code may be useful as a base for code generation
+    of other SNMP agents.
+
+Notes:
+  - Stack and MIB compiler were used to implement a Profinet device.
+    Compiled/implemented MIBs: LLDP-MIB, LLDP-EXT-DOT3-MIB, LLDP-EXT-PNO-MIB.

ext/lwip/src/apps/snmp/snmp_asn1.c

@@ -0,0 +1,749 @@
+/**
+ * @file
+ * Abstract Syntax Notation One (ISO 8824, 8825) encoding
+ *
+ * @todo not optimised (yet), favor correctness over speed, favor speed over size
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Christiaan Simons <christiaan.simons@axon.tv>
+ *         Martin Hentschel <info@cl-soft.de>
+ */
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
+
+#include "snmp_asn1.h"
+
+#define PBUF_OP_EXEC(code) \
+  if ((code) != ERR_OK) { \
+    return ERR_BUF; \
+  }
+
+/**
+ * Encodes a TLV into a pbuf stream.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param tlv TLV to encode
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
+ */
+err_t
+snmp_ans1_enc_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tlv)
+{
+  u8_t data;
+  u8_t length_bytes_required;
+
+  /* write type */
+  if ((tlv->type & SNMP_ASN1_DATATYPE_MASK) == SNMP_ASN1_DATATYPE_EXTENDED) {
+    /* extended format is not used by SNMP so we do not accept those values */
+    return ERR_ARG;
+  }
+  if (tlv->type_len != 0) {
+    /* any other value as auto is not accepted for type (we always use one byte because extended syntax is prohibited) */
+    return ERR_ARG;
+  }
+
+  PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, tlv->type));
+  tlv->type_len = 1;
+
+  /* write length */
+  if (tlv->value_len <= 127) {
+    length_bytes_required = 1;
+  } else if (tlv->value_len <= 255) {
+    length_bytes_required = 2;
+  } else  {
+    length_bytes_required = 3;
+  }
+
+  /* check for forced min length */
+  if (tlv->length_len > 0) {
+    if (tlv->length_len < length_bytes_required) {
+      /* unable to code requested length in requested number of bytes */
+      return ERR_ARG;
+    }
+
+    length_bytes_required = tlv->length_len;
+  } else {
+    tlv->length_len = length_bytes_required;
+  }
+
+  if (length_bytes_required > 1) {
+    /* multi byte representation required */
+    length_bytes_required--;
+    data = 0x80 | length_bytes_required; /* extended length definition, 1 length byte follows */
+
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, data));
+
+    while (length_bytes_required > 1) {
+      if (length_bytes_required == 2) {
+        /* append high byte */
+        data = (u8_t)(tlv->value_len >> 8);
+      } else {
+        /* append leading 0x00 */
+        data = 0x00;
+      }
+
+      PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, data));
+      length_bytes_required--;
+    }
+  }
+
+  /* append low byte */
+  data = (u8_t)(tlv->value_len & 0xFF);
+  PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, data));
+
+  return ERR_OK;
+}
+
+/**
+ * Encodes raw data (octet string, opaque) into a pbuf chained ASN1 msg.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param raw_len raw data length
+ * @param raw points raw data
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
+ */
+err_t
+snmp_asn1_enc_raw(struct snmp_pbuf_stream* pbuf_stream, const u8_t *raw, u16_t raw_len)
+{
+  PBUF_OP_EXEC(snmp_pbuf_stream_writebuf(pbuf_stream, raw, raw_len));
+
+  return ERR_OK;
+}
+
+/**
+ * Encodes u32_t (counter, gauge, timeticks) into a pbuf chained ASN1 msg.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param octets_needed encoding length (from snmp_asn1_enc_u32t_cnt())
+ * @param value is the host order u32_t value to be encoded
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
+ *
+ * @see snmp_asn1_enc_u32t_cnt()
+ */
+err_t
+snmp_asn1_enc_u32t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, u32_t value)
+{
+  if (octets_needed > 5) {
+    return ERR_ARG;
+  }
+  if (octets_needed == 5) {
+    /* not enough bits in 'value' add leading 0x00 */
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, 0x00));
+    octets_needed--;
+  }
+
+  while (octets_needed > 1) {
+    octets_needed--;
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(value >> (octets_needed << 3))));
+  }
+
+  /* (only) one least significant octet */
+  PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)value));
+
+  return ERR_OK;
+}
+
+/**
+ * Encodes u64_t (counter64) into a pbuf chained ASN1 msg.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param octets_needed encoding length (from snmp_asn1_enc_u32t_cnt())
+ * @param value is the host order u32_t value to be encoded
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
+ *
+ * @see snmp_asn1_enc_u64t_cnt()
+ */
+err_t
+snmp_asn1_enc_u64t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, const u32_t* value)
+{
+  if (octets_needed > 9) {
+    return ERR_ARG;
+  }
+  if (octets_needed == 9) {
+    /* not enough bits in 'value' add leading 0x00 */
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, 0x00));
+    octets_needed--;
+  }
+
+  while (octets_needed > 4) {
+    octets_needed--;
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(*value >> ((octets_needed-4) << 3))));
+  }
+  
+  /* skip to low u32 */
+  value++;
+  
+  while (octets_needed > 1) {
+    octets_needed--;
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(*value >> (octets_needed << 3))));
+  }
+
+  /* always write at least one octet (also in case of value == 0) */
+  PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(*value)));
+
+  return ERR_OK;
+}
+
+/**
+ * Encodes s32_t integer into a pbuf chained ASN1 msg.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param octets_needed encoding length (from snmp_asn1_enc_s32t_cnt())
+ * @param value is the host order s32_t value to be encoded
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
+ *
+ * @see snmp_asn1_enc_s32t_cnt()
+ */
+err_t
+snmp_asn1_enc_s32t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, s32_t value)
+{
+  while (octets_needed > 1) {
+    octets_needed--;
+
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)(value >> (octets_needed << 3))));
+  }
+
+  /* (only) one least significant octet */
+  PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)value));
+
+  return ERR_OK;
+}
+
+/**
+ * Encodes object identifier into a pbuf chained ASN1 msg.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param oid points to object identifier array
+ * @param oid_len object identifier array length
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) encode
+ */
+err_t
+snmp_asn1_enc_oid(struct snmp_pbuf_stream* pbuf_stream, const u32_t *oid, u16_t oid_len)
+{
+  if (oid_len > 1) {
+    /* write compressed first two sub id's */
+    u32_t compressed_byte = ((oid[0] * 40) + oid[1]);
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)compressed_byte));
+    oid_len -= 2;
+    oid += 2;
+  } else {
+    /* @bug:  allow empty varbinds for symmetry (we must decode them for getnext), allow partial compression?? */
+    /* ident_len <= 1, at least we need zeroDotZero (0.0) (ident_len == 2) */
+    return ERR_ARG;
+  }
+
+  while (oid_len > 0) {
+    u32_t sub_id;
+    u8_t shift, tail;
+
+    oid_len--;
+    sub_id = *oid;
+    tail = 0;
+    shift = 28;
+    while (shift > 0) {
+      u8_t code;
+
+      code = (u8_t)(sub_id >> shift);
+      if ((code != 0) || (tail != 0)) {
+        tail = 1;
+        PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, code | 0x80));
+      }
+      shift -= 7;
+    }
+    PBUF_OP_EXEC(snmp_pbuf_stream_write(pbuf_stream, (u8_t)sub_id & 0x7F));
+
+    /* proceed to next sub-identifier */
+    oid++;
+  }
+  return ERR_OK;
+}
+
+/**
+ * Returns octet count for length.
+ *
+ * @param length
+ * @param octets_needed points to the return value
+ */
+void
+snmp_asn1_enc_length_cnt(u16_t length, u8_t *octets_needed)
+{
+  if (length < 0x80U) {
+    *octets_needed = 1;
+  } else if (length < 0x100U) {
+    *octets_needed = 2;
+  } else {
+    *octets_needed = 3;
+  }
+}
+
+/**
+ * Returns octet count for an u32_t.
+ *
+ * @param value
+ * @param octets_needed points to the return value
+ *
+ * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded
+ * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value
+ * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!!
+ */
+void
+snmp_asn1_enc_u32t_cnt(u32_t value, u16_t *octets_needed)
+{
+  if (value < 0x80UL) {
+    *octets_needed = 1;
+  } else if (value < 0x8000UL) {
+    *octets_needed = 2;
+  } else if (value < 0x800000UL) {
+    *octets_needed = 3;
+  } else if (value < 0x80000000UL) {
+    *octets_needed = 4;
+  } else {
+    *octets_needed = 5;
+  }
+}
+
+/**
+ * Returns octet count for an u64_t.
+ *
+ * @param value
+ * @param octets_needed points to the return value
+ *
+ * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded
+ * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value
+ * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!!
+ */
+void
+snmp_asn1_enc_u64t_cnt(const u32_t *value, u16_t *octets_needed)
+{
+  /* check if high u32 is 0 */
+  if (*value == 0x00) {
+    /* only low u32 is important */
+    value++;
+    snmp_asn1_enc_u32t_cnt(*value, octets_needed);
+  } else {
+    /* low u32 does not matter for length determination */
+    snmp_asn1_enc_u32t_cnt(*value, octets_needed);
+    *octets_needed = *octets_needed + 4; /* add the 4 bytes of low u32 */
+  }
+}
+
+/**
+ * Returns octet count for an s32_t.
+ *
+ * @param value
+ * @param octets_needed points to the return value
+ *
+ * @note ASN coded integers are _always_ signed.
+ */
+void
+snmp_asn1_enc_s32t_cnt(s32_t value, u16_t *octets_needed)
+{
+  if (value < 0) {
+    value = ~value;
+  } 
+  if (value < 0x80L) {
+    *octets_needed = 1;
+  } else if (value < 0x8000L) {
+    *octets_needed = 2;
+  } else if (value < 0x800000L) {
+    *octets_needed = 3;
+  } else {
+    *octets_needed = 4;
+  }
+}
+
+/**
+ * Returns octet count for an object identifier.
+ *
+ * @param oid points to object identifier array
+ * @param oid_len object identifier array length
+ * @param octets_needed points to the return value
+ */
+void
+snmp_asn1_enc_oid_cnt(const u32_t *oid, u16_t oid_len, u16_t *octets_needed)
+{
+  u32_t sub_id;
+
+  *octets_needed = 0;
+  if (oid_len > 1) {
+    /* compressed prefix in one octet */
+    (*octets_needed)++;
+    oid_len -= 2;
+    oid += 2;
+  }
+  while (oid_len > 0) {
+    oid_len--;
+    sub_id = *oid;
+
+    sub_id >>= 7;
+    (*octets_needed)++;
+    while (sub_id > 0) {
+      sub_id >>= 7;
+      (*octets_needed)++;
+    }
+    oid++;
+  }
+}
+
+/**
+ * Decodes a TLV from a pbuf stream.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param tlv returns decoded TLV
+ * @return ERR_OK if successful, ERR_VAL if we can't decode
+ */
+err_t
+snmp_asn1_dec_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tlv)
+{
+  u8_t data;
+
+  /* decode type first */
+  PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+  tlv->type = data;
+
+  if ((tlv->type & SNMP_ASN1_DATATYPE_MASK) == SNMP_ASN1_DATATYPE_EXTENDED) {
+    /* extended format is not used by SNMP so we do not accept those values */
+    return ERR_VAL;
+  }
+  tlv->type_len = 1;
+
+  /* now, decode length */
+  PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+
+  if (data < 0x80) { /* short form */
+    tlv->length_len = 1;
+    tlv->value_len  = data;
+  } else if (data > 0x80) { /* long form */
+    u8_t length_bytes = data - 0x80;
+    tlv->length_len = length_bytes + 1; /* this byte + defined number of length bytes following */
+    tlv->value_len = 0;
+
+    while (length_bytes > 0) {
+      /* we only support up to u16.maxvalue-1 (2 bytes) but have to accept leading zero bytes */
+      if (tlv->value_len > 0xFF) {
+        return ERR_VAL;
+      }
+      PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+      tlv->value_len <<= 8;
+      tlv->value_len |= data;
+      
+      /* take care for special value used for indefinite length */
+      if (tlv->value_len == 0xFFFF) {
+        return ERR_VAL;
+      }
+
+      length_bytes--;
+    }
+  } else { /* data == 0x80 indefinite length form */
+    /* (not allowed for SNMP; RFC 1157, 3.2.2) */
+    return ERR_VAL;
+  }
+
+  return ERR_OK;
+}
+
+/**
+ * Decodes positive integer (counter, gauge, timeticks) into u32_t.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param len length of the coded integer field
+ * @param value return host order integer
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode
+ *
+ * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded
+ * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value
+ * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!!
+ */
+err_t
+snmp_asn1_dec_u32t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t *value)
+{
+  u8_t data;
+
+  if ((len > 0) && (len <= 5)) {
+    PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+
+    /* expecting sign bit to be zero, only unsigned please! */
+    if (((len == 5) && (data == 0x00)) || ((len < 5) && ((data & 0x80) == 0))) {
+      *value = data;
+      len--;
+
+      while (len > 0) {
+        PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+        len--;
+
+        *value <<= 8;
+        *value |= data;
+      }
+
+      return ERR_OK;
+    }
+  }
+
+  return ERR_VAL;
+}
+
+/**
+ * Decodes large positive integer (counter64) into 2x u32_t.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param len length of the coded integer field
+ * @param value return host order integer
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode
+ *
+ * @note ASN coded integers are _always_ signed. E.g. +0xFFFF is coded
+ * as 0x00,0xFF,0xFF. Note the leading sign octet. A positive value
+ * of 0xFFFFFFFF is preceded with 0x00 and the length is 5 octets!!
+ */
+err_t
+snmp_asn1_dec_u64t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t *value)
+{
+  u8_t data;
+
+  if (len <= 4) {
+    /* high u32 is 0 */
+    *value = 0;
+    /* directly skip to low u32 */
+    value++;
+  }
+
+  if ((len > 0) && (len <= 9)) {
+    PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+
+    /* expecting sign bit to be zero, only unsigned please! */
+    if (((len == 9) && (data == 0x00)) || ((len < 9) && ((data & 0x80) == 0))) {
+      *value = data;
+      len--;
+
+      while (len > 0) {
+        PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+
+        if (len == 4) {
+          /* skip to low u32 */
+          value++;
+          *value = 0;
+        } else {
+          *value <<= 8;
+        }
+        
+        *value |= data;
+        len--;
+      }
+
+      return ERR_OK;
+    }
+  }
+
+  return ERR_VAL;
+}
+
+/**
+ * Decodes integer into s32_t.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param len length of the coded integer field
+ * @param value return host order integer
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode
+ *
+ * @note ASN coded integers are _always_ signed!
+ */
+err_t
+snmp_asn1_dec_s32t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, s32_t *value)
+{
+#if BYTE_ORDER == LITTLE_ENDIAN
+  u8_t *lsb_ptr = (u8_t*)value;
+#endif
+#if BYTE_ORDER == BIG_ENDIAN
+  u8_t *lsb_ptr = (u8_t*)value + sizeof(s32_t) - 1;
+#endif
+  u8_t sign;
+  u8_t data;
+
+  if ((len > 0) && (len < 5)) {
+    PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+    len--;
+    
+    if (data & 0x80) {
+      /* negative, start from -1 */
+      *value = -1;
+      sign = 1;
+      *lsb_ptr &= data;
+    } else {
+      /* positive, start from 0 */
+      *value = 0;
+      sign = 0;
+      *lsb_ptr |= data;
+    }
+
+    /* OR/AND octets with value */
+    while (len > 0) {
+      PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+      len--;
+
+#if BYTE_ORDER == LITTLE_ENDIAN
+      *value <<= 8;
+#endif
+#if BYTE_ORDER == BIG_ENDIAN
+      *value >>= 8;
+#endif
+
+      if (sign) {
+        *lsb_ptr |= 255;
+        *lsb_ptr &= data;
+      } else {
+        *lsb_ptr |= data;
+      }
+    }
+
+    return ERR_OK;
+  }
+
+  return ERR_VAL;
+}
+
+/**
+ * Decodes object identifier from incoming message into array of u32_t.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param len length of the coded object identifier
+ * @param oid return decoded object identifier
+ * @param oid_len return decoded object identifier length
+ * @param oid_max_len size of oid buffer
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode
+ */
+err_t
+snmp_asn1_dec_oid(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t* oid, u8_t* oid_len, u8_t oid_max_len)
+{
+  u32_t *oid_ptr;
+  u8_t data;
+
+  *oid_len = 0;
+  oid_ptr = oid;
+  if (len > 0) {
+    if (oid_max_len < 2) {
+      return ERR_MEM;
+    }
+    
+    PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+    len--;
+
+    /* first compressed octet */
+    if (data == 0x2B) {
+      /* (most) common case 1.3 (iso.org) */
+      *oid_ptr = 1;
+      oid_ptr++;
+      *oid_ptr = 3;
+      oid_ptr++;
+    } else if (data < 40) {
+      *oid_ptr = 0;
+      oid_ptr++;
+      *oid_ptr = data;
+      oid_ptr++;
+    } else if (data < 80) {
+      *oid_ptr = 1;
+      oid_ptr++;
+      *oid_ptr = data - 40;
+      oid_ptr++;
+    } else {
+      *oid_ptr = 2;
+      oid_ptr++;
+      *oid_ptr = data - 80;
+      oid_ptr++;
+    }
+    *oid_len = 2;
+  } else {
+    /* accepting zero length identifiers e.g. for getnext operation. uncommon but valid */
+    return ERR_OK;
+  }
+
+  while ((len > 0) && (*oid_len < oid_max_len)) {
+    PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+    len--;
+
+    if ((data & 0x80) == 0x00) {
+      /* sub-identifier uses single octet */
+      *oid_ptr = data;
+    } else {
+      /* sub-identifier uses multiple octets */
+      u32_t sub_id = (data & ~0x80);
+      while ((len > 0) && ((data & 0x80) != 0)) {
+        PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, &data));
+        len--;
+
+        sub_id = (sub_id << 7) + (data & ~0x80);
+      }
+
+      if ((data & 0x80) != 0) {
+        /* "more bytes following" bit still set at end of len */
+        return ERR_VAL;
+      }
+      *oid_ptr = sub_id;
+    }
+    oid_ptr++;
+    (*oid_len)++;
+  }
+
+  if (len > 0) {
+    /* OID to long to fit in our buffer */
+    return ERR_MEM;
+  }
+
+  return ERR_OK;
+}
+
+/**
+ * Decodes (copies) raw data (ip-addresses, octet strings, opaque encoding)
+ * from incoming message into array.
+ *
+ * @param pbuf_stream points to a pbuf stream
+ * @param len length of the coded raw data (zero is valid, e.g. empty string!)
+ * @param buf return raw bytes
+ * @param buf_len returns length of the raw return value
+ * @param buf_max_len buffer size
+ * @return ERR_OK if successful, ERR_ARG if we can't (or won't) decode
+ */
+err_t
+snmp_asn1_dec_raw(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u8_t *buf, u16_t* buf_len, u16_t buf_max_len)
+{
+  if (len > buf_max_len) {
+    /* not enough dst space */
+    return ERR_MEM;
+  }
+  *buf_len = len;
+  
+  while (len > 0) {
+    PBUF_OP_EXEC(snmp_pbuf_stream_read(pbuf_stream, buf));
+    buf++;
+    len--;
+  }
+
+  return ERR_OK;
+}
+
+#endif /* LWIP_SNMP */

ext/lwip/src/apps/snmp/snmp_asn1.h

@@ -0,0 +1,108 @@
+/**
+ * @file
+ * Abstract Syntax Notation One (ISO 8824, 8825) codec.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * Copyright (c) 2016 Elias Oenal.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Christiaan Simons <christiaan.simons@axon.tv>
+ *         Martin Hentschel <info@cl-soft.de>
+ *         Elias Oenal <lwip@eliasoenal.com>
+ */
+
+#ifndef LWIP_HDR_APPS_SNMP_ASN1_H
+#define LWIP_HDR_APPS_SNMP_ASN1_H
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP
+
+#include "lwip/err.h"
+#include "lwip/apps/snmp_core.h"
+#include "snmp_pbuf_stream.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define SNMP_ASN1_TLV_INDEFINITE_LENGTH 0x80
+
+#define SNMP_ASN1_CLASS_MASK        0xC0
+#define SNMP_ASN1_CONTENTTYPE_MASK  0x20
+#define SNMP_ASN1_DATATYPE_MASK     0x1F
+#define SNMP_ASN1_DATATYPE_EXTENDED 0x1F /* DataType indicating that datatype is encoded in following bytes */
+
+/* context specific (SNMP) tags (from SNMP spec. RFC1157) */
+#define SNMP_ASN1_CONTEXT_PDU_GET_REQ      0
+#define SNMP_ASN1_CONTEXT_PDU_GET_NEXT_REQ 1
+#define SNMP_ASN1_CONTEXT_PDU_GET_RESP     2
+#define SNMP_ASN1_CONTEXT_PDU_SET_REQ      3
+#define SNMP_ASN1_CONTEXT_PDU_TRAP         4
+#define SNMP_ASN1_CONTEXT_PDU_GET_BULK_REQ 5
+
+#define SNMP_ASN1_CONTEXT_VARBIND_NO_SUCH_OBJECT      0
+#define SNMP_ASN1_CONTEXT_VARBIND_END_OF_MIB_VIEW     2
+
+struct snmp_asn1_tlv
+{
+  u8_t  type;       /* only U8 because extended types are not specified by SNMP */
+  u8_t  type_len;   /* encoded length of 'type' field (normally 1) */
+  u8_t  length_len; /* indicates how many bytes are required to encode the 'value_len' field */
+  u16_t value_len;  /* encoded length of the value */
+};
+#define SNMP_ASN1_TLV_HDR_LENGTH(tlv) ((tlv).type_len + (tlv).length_len)
+#define SNMP_ASN1_TLV_LENGTH(tlv) ((tlv).type_len + (tlv).length_len + (tlv).value_len)
+#define SNMP_ASN1_SET_TLV_PARAMS(tlv, type_, length_len_, value_len_) do { (tlv).type = (type_); (tlv).type_len = 0; (tlv).length_len = (length_len_); (tlv).value_len = (value_len_); } while (0);
+
+err_t snmp_asn1_dec_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tlv);
+err_t snmp_asn1_dec_u32t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t *value);
+err_t snmp_asn1_dec_u64t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t *value);
+err_t snmp_asn1_dec_s32t(struct snmp_pbuf_stream *pbuf_stream, u16_t len, s32_t *value);
+err_t snmp_asn1_dec_oid(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u32_t* oid, u8_t* oid_len, u8_t oid_max_len);
+err_t snmp_asn1_dec_raw(struct snmp_pbuf_stream *pbuf_stream, u16_t len, u8_t *buf, u16_t* buf_len, u16_t buf_max_len);
+
+err_t snmp_ans1_enc_tlv(struct snmp_pbuf_stream* pbuf_stream, struct snmp_asn1_tlv* tlv);
+
+void snmp_asn1_enc_length_cnt(u16_t length, u8_t *octets_needed);
+void snmp_asn1_enc_u32t_cnt(u32_t value, u16_t *octets_needed);
+void snmp_asn1_enc_u64t_cnt(const u32_t *value, u16_t *octets_needed);
+void snmp_asn1_enc_s32t_cnt(s32_t value, u16_t *octets_needed);
+void snmp_asn1_enc_oid_cnt(const u32_t *oid, u16_t oid_len, u16_t *octets_needed);
+err_t snmp_asn1_enc_oid(struct snmp_pbuf_stream* pbuf_stream, const u32_t *oid, u16_t oid_len);
+err_t snmp_asn1_enc_s32t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, s32_t value);
+err_t snmp_asn1_enc_u32t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, u32_t value);
+err_t snmp_asn1_enc_u64t(struct snmp_pbuf_stream* pbuf_stream, u16_t octets_needed, const u32_t* value);
+err_t snmp_asn1_enc_raw(struct snmp_pbuf_stream* pbuf_stream, const u8_t *raw, u16_t raw_len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LWIP_SNMP */
+
+#endif /* LWIP_HDR_APPS_SNMP_ASN1_H */

ext/lwip/src/apps/snmp/snmp_core_priv.h

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Martin Hentschel <info@cl-soft.de>
+ *
+ */
+
+#ifndef LWIP_HDR_APPS_SNMP_CORE_PRIV_H
+#define LWIP_HDR_APPS_SNMP_CORE_PRIV_H
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/apps/snmp_core.h"
+#include "snmp_asn1.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* (outdated) SNMPv1 error codes
+ * shall not be used by MIBS anymore, nevertheless required from core for properly answering a v1 request
+ */
+#define SNMP_ERR_NOSUCHNAME 2
+#define SNMP_ERR_BADVALUE   3
+#define SNMP_ERR_READONLY   4
+/* error codes which are internal and shall not be used by MIBS
+ * shall not be used by MIBS anymore, nevertheless required from core for properly answering a v1 request
+ */
+#define SNMP_ERR_TOOBIG               1
+#define SNMP_ERR_AUTHORIZATIONERROR   16
+#define SNMP_ERR_NOSUCHOBJECT         SNMP_VARBIND_EXCEPTION_OFFSET + SNMP_ASN1_CONTEXT_VARBIND_NO_SUCH_OBJECT
+#define SNMP_ERR_ENDOFMIBVIEW         SNMP_VARBIND_EXCEPTION_OFFSET + SNMP_ASN1_CONTEXT_VARBIND_END_OF_MIB_VIEW
+
+
+const struct snmp_node* snmp_mib_tree_resolve_exact(const struct snmp_mib *mib, const u32_t *oid, u8_t oid_len, u8_t* oid_instance_len);
+const struct snmp_node* snmp_mib_tree_resolve_next(const struct snmp_mib *mib, const u32_t *oid, u8_t oid_len, struct snmp_obj_id* oidret);
+
+typedef u8_t (*snmp_validate_node_instance_method)(struct snmp_node_instance*, void*);
+
+u8_t snmp_get_node_instance_from_oid(const u32_t *oid, u8_t oid_len, struct snmp_node_instance* node_instance);
+u8_t snmp_get_next_node_instance_from_oid(const u32_t *oid, u8_t oid_len, snmp_validate_node_instance_method validate_node_instance_method, void* validate_node_instance_arg, struct snmp_obj_id* node_oid, struct snmp_node_instance* node_instance);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LWIP_SNMP */
+
+#endif /* LWIP_HDR_APPS_SNMP_CORE_PRIV_H */

ext/lwip/src/apps/snmp/snmp_mib2.c

@@ -0,0 +1,116 @@
+/**
+ * @file
+ * Management Information Base II (RFC1213) objects and functions.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ */
+
+/**
+ * @defgroup snmp_mib2 MIB2
+ * @ingroup snmp
+ */
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP && SNMP_LWIP_MIB2 /* don't build if not configured for use in lwipopts.h */
+
+#if !LWIP_STATS
+#error LWIP_SNMP MIB2 needs LWIP_STATS (for MIB2)
+#endif
+#if !MIB2_STATS
+#error LWIP_SNMP MIB2 needs MIB2_STATS (for MIB2)
+#endif
+
+#include "lwip/snmp.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_mib2.h"
+#include "lwip/apps/snmp_scalar.h"
+
+#if SNMP_USE_NETCONN
+#include "lwip/tcpip.h"
+#include "lwip/priv/tcpip_priv.h"
+void
+snmp_mib2_lwip_synchronizer(snmp_threadsync_called_fn fn, void* arg)
+{
+#if LWIP_TCPIP_CORE_LOCKING
+  LOCK_TCPIP_CORE();
+  fn(arg);
+  UNLOCK_TCPIP_CORE();
+#else
+  tcpip_callback(fn, arg);
+#endif
+}
+
+struct snmp_threadsync_instance snmp_mib2_lwip_locks;
+#endif
+
+/* dot3 and EtherLike MIB not planned. (transmission .1.3.6.1.2.1.10) */
+/* historical (some say hysterical). (cmot .1.3.6.1.2.1.9) */
+/* lwIP has no EGP, thus may not implement it. (egp .1.3.6.1.2.1.8) */
+
+/* --- mib-2 .1.3.6.1.2.1 ----------------------------------------------------- */
+extern const struct snmp_scalar_array_node snmp_mib2_snmp_root;
+extern const struct snmp_tree_node snmp_mib2_udp_root;
+extern const struct snmp_tree_node snmp_mib2_tcp_root;
+extern const struct snmp_scalar_array_node snmp_mib2_icmp_root;
+extern const struct snmp_tree_node snmp_mib2_interface_root;
+extern const struct snmp_scalar_array_node snmp_mib2_system_node;
+extern const struct snmp_tree_node snmp_mib2_at_root;
+extern const struct snmp_tree_node snmp_mib2_ip_root;
+
+static const struct snmp_node* const mib2_nodes[] = {
+  &snmp_mib2_system_node.node.node,
+  &snmp_mib2_interface_root.node,
+#if LWIP_ARP && LWIP_IPV4
+  &snmp_mib2_at_root.node,
+#endif /* LWIP_ARP && LWIP_IPV4 */
+#if LWIP_IPV4
+  &snmp_mib2_ip_root.node,
+#endif /* LWIP_IPV4 */
+#if LWIP_ICMP
+  &snmp_mib2_icmp_root.node.node,
+#endif /* LWIP_ICMP */
+#if LWIP_TCP
+  &snmp_mib2_tcp_root.node,
+#endif /* LWIP_TCP */
+#if LWIP_UDP
+  &snmp_mib2_udp_root.node,
+#endif /* LWIP_UDP */
+  &snmp_mib2_snmp_root.node.node
+};
+
+static const struct snmp_tree_node mib2_root = SNMP_CREATE_TREE_NODE(1, mib2_nodes);
+
+static const u32_t  mib2_base_oid_arr[] = { 1,3,6,1,2,1 };
+const struct snmp_mib mib2 = SNMP_MIB_CREATE(mib2_base_oid_arr, &mib2_root.node);
+
+#endif /* LWIP_SNMP && SNMP_LWIP_MIB2 */

ext/lwip/src/apps/snmp/snmp_mib2_icmp.c

@@ -0,0 +1,182 @@
+/**
+ * @file
+ * Management Information Base II (RFC1213) ICMP objects and functions.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ */
+
+#include "lwip/snmp.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_mib2.h"
+#include "lwip/apps/snmp_table.h"
+#include "lwip/apps/snmp_scalar.h"
+#include "lwip/icmp.h"
+#include "lwip/stats.h"
+
+#if LWIP_SNMP && SNMP_LWIP_MIB2 && LWIP_ICMP
+
+#if SNMP_USE_NETCONN
+#define SYNC_NODE_NAME(node_name) node_name ## _synced
+#define CREATE_LWIP_SYNC_NODE(oid, node_name) \
+   static const struct snmp_threadsync_node node_name ## _synced = SNMP_CREATE_THREAD_SYNC_NODE(oid, &node_name.node, &snmp_mib2_lwip_locks);
+#else
+#define SYNC_NODE_NAME(node_name) node_name
+#define CREATE_LWIP_SYNC_NODE(oid, node_name)
+#endif
+
+/* --- icmp .1.3.6.1.2.1.5 ----------------------------------------------------- */
+
+static s16_t
+icmp_get_value(const struct snmp_scalar_array_node_def *node, void *value)
+{
+  u32_t *uint_ptr = (u32_t*)value;
+
+  switch (node->oid) {
+  case 1: /* icmpInMsgs */
+    *uint_ptr = STATS_GET(mib2.icmpinmsgs);
+    return sizeof(*uint_ptr);
+  case 2: /* icmpInErrors */
+    *uint_ptr = STATS_GET(mib2.icmpinerrors);
+    return sizeof(*uint_ptr);
+  case 3: /* icmpInDestUnreachs */
+    *uint_ptr = STATS_GET(mib2.icmpindestunreachs);
+    return sizeof(*uint_ptr);
+  case 4: /* icmpInTimeExcds */
+    *uint_ptr = STATS_GET(mib2.icmpintimeexcds);
+    return sizeof(*uint_ptr);
+  case 5: /* icmpInParmProbs */
+    *uint_ptr = STATS_GET(mib2.icmpinparmprobs);
+    return sizeof(*uint_ptr);
+  case 6: /* icmpInSrcQuenchs */
+    *uint_ptr = STATS_GET(mib2.icmpinsrcquenchs);
+    return sizeof(*uint_ptr);
+  case 7: /* icmpInRedirects */
+    *uint_ptr = STATS_GET(mib2.icmpinredirects);
+    return sizeof(*uint_ptr);
+  case 8: /* icmpInEchos */
+    *uint_ptr = STATS_GET(mib2.icmpinechos);
+    return sizeof(*uint_ptr);
+  case 9: /* icmpInEchoReps */
+    *uint_ptr = STATS_GET(mib2.icmpinechoreps);
+    return sizeof(*uint_ptr);
+  case 10: /* icmpInTimestamps */
+    *uint_ptr = STATS_GET(mib2.icmpintimestamps);
+    return sizeof(*uint_ptr);
+  case 11: /* icmpInTimestampReps */
+    *uint_ptr = STATS_GET(mib2.icmpintimestampreps);
+    return sizeof(*uint_ptr);
+  case 12: /* icmpInAddrMasks */
+    *uint_ptr = STATS_GET(mib2.icmpinaddrmasks);
+    return sizeof(*uint_ptr);
+  case 13: /* icmpInAddrMaskReps */
+    *uint_ptr = STATS_GET(mib2.icmpinaddrmaskreps);
+    return sizeof(*uint_ptr);
+  case 14: /* icmpOutMsgs */
+    *uint_ptr = STATS_GET(mib2.icmpoutmsgs);
+    return sizeof(*uint_ptr);
+  case 15: /* icmpOutErrors */
+    *uint_ptr = STATS_GET(mib2.icmpouterrors);
+    return sizeof(*uint_ptr);
+  case 16: /* icmpOutDestUnreachs */
+    *uint_ptr = STATS_GET(mib2.icmpoutdestunreachs);
+    return sizeof(*uint_ptr);
+  case 17: /* icmpOutTimeExcds */
+    *uint_ptr = STATS_GET(mib2.icmpouttimeexcds);
+    return sizeof(*uint_ptr);
+  case 18: /* icmpOutParmProbs: not supported -> always 0 */
+    *uint_ptr = 0;
+    return sizeof(*uint_ptr);
+  case 19: /* icmpOutSrcQuenchs: not supported -> always 0 */
+    *uint_ptr = 0;
+    return sizeof(*uint_ptr);
+  case 20: /* icmpOutRedirects: not supported -> always 0 */
+    *uint_ptr = 0;
+    return sizeof(*uint_ptr);
+  case 21: /* icmpOutEchos */
+    *uint_ptr = STATS_GET(mib2.icmpoutechos);
+    return sizeof(*uint_ptr);
+  case 22: /* icmpOutEchoReps */
+    *uint_ptr = STATS_GET(mib2.icmpoutechoreps);
+    return sizeof(*uint_ptr);
+  case 23: /* icmpOutTimestamps: not supported -> always 0 */
+    *uint_ptr = 0;
+    return sizeof(*uint_ptr);
+  case 24: /* icmpOutTimestampReps: not supported -> always 0 */
+    *uint_ptr = 0;
+    return sizeof(*uint_ptr);
+  case 25: /* icmpOutAddrMasks: not supported -> always 0 */
+    *uint_ptr = 0;
+    return sizeof(*uint_ptr);
+  case 26: /* icmpOutAddrMaskReps: not supported -> always 0 */
+    *uint_ptr = 0;
+    return sizeof(*uint_ptr);
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("icmp_get_value(): unknown id: %"S32_F"\n", node->oid));
+    break;
+  }
+
+  return 0;
+}
+
+
+static const struct snmp_scalar_array_node_def icmp_nodes[] = {
+  { 1, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  { 2, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  { 3, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  { 4, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  { 5, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  { 6, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  { 7, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  { 8, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  { 9, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {10, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {11, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {12, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {13, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {14, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {15, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {16, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {17, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {18, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {19, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {20, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {21, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {22, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {23, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {24, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {25, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},
+  {26, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY}
+};
+
+const struct snmp_scalar_array_node snmp_mib2_icmp_root = SNMP_SCALAR_CREATE_ARRAY_NODE(5, icmp_nodes, icmp_get_value, NULL, NULL);
+
+#endif /* LWIP_SNMP && SNMP_LWIP_MIB2 && LWIP_ICMP */

ext/lwip/src/apps/snmp/snmp_mib2_interfaces.c

@@ -0,0 +1,376 @@
+/**
+ * @file
+ * Management Information Base II (RFC1213) INTERFACES objects and functions.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ */
+
+#include "lwip/snmp.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_mib2.h"
+#include "lwip/apps/snmp_table.h"
+#include "lwip/apps/snmp_scalar.h"
+#include "lwip/netif.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+#if LWIP_SNMP && SNMP_LWIP_MIB2
+
+#if SNMP_USE_NETCONN
+#define SYNC_NODE_NAME(node_name) node_name ## _synced
+#define CREATE_LWIP_SYNC_NODE(oid, node_name) \
+   static const struct snmp_threadsync_node node_name ## _synced = SNMP_CREATE_THREAD_SYNC_NODE(oid, &node_name.node, &snmp_mib2_lwip_locks);
+#else
+#define SYNC_NODE_NAME(node_name) node_name
+#define CREATE_LWIP_SYNC_NODE(oid, node_name)
+#endif
+
+
+/* --- interfaces .1.3.6.1.2.1.2 ----------------------------------------------------- */
+
+static s16_t 
+interfaces_get_value(struct snmp_node_instance* instance, void* value)
+{
+  if (instance->node->oid == 1) {
+    s32_t *sint_ptr = (s32_t*)value;
+    s32_t num_netifs = 0;
+
+    struct netif *netif = netif_list;
+    while (netif != NULL) {
+      num_netifs++;
+      netif = netif->next;
+    }
+
+    *sint_ptr = num_netifs;
+    return sizeof(*sint_ptr);
+  }
+
+  return 0;
+}
+
+/* list of allowed value ranges for incoming OID */
+static const struct snmp_oid_range interfaces_Table_oid_ranges[] = {
+  { 1, 0xff } /* netif->num is u8_t */
+};
+
+static const u8_t iftable_ifOutQLen         = 0;
+
+static const u8_t iftable_ifOperStatus_up   = 1;
+static const u8_t iftable_ifOperStatus_down = 2;
+
+static const u8_t iftable_ifAdminStatus_up             = 1;
+static const u8_t iftable_ifAdminStatus_lowerLayerDown = 7;
+static const u8_t iftable_ifAdminStatus_down           = 2;
+
+static snmp_err_t
+interfaces_Table_get_cell_instance(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, struct snmp_node_instance* cell_instance)
+{
+  u32_t ifIndex;
+  struct netif *netif;
+
+  LWIP_UNUSED_ARG(column);
+
+  /* check if incoming OID length and if values are in plausible range */
+  if (!snmp_oid_in_range(row_oid, row_oid_len, interfaces_Table_oid_ranges, LWIP_ARRAYSIZE(interfaces_Table_oid_ranges))) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* get netif index from incoming OID */
+  ifIndex = row_oid[0];
+
+  /* find netif with index */
+  netif = netif_list;
+  while (netif != NULL) {
+    if (netif_to_num(netif) == ifIndex) {
+      /* store netif pointer for subsequent operations (get/test/set) */
+      cell_instance->reference.ptr = netif;
+      return SNMP_ERR_NOERROR;
+    }
+    netif = netif->next;
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+static snmp_err_t
+interfaces_Table_get_next_cell_instance(const u32_t* column, struct snmp_obj_id* row_oid, struct snmp_node_instance* cell_instance)
+{
+  struct netif *netif;
+  struct snmp_next_oid_state state;
+  u32_t result_temp[LWIP_ARRAYSIZE(interfaces_Table_oid_ranges)];
+
+  LWIP_UNUSED_ARG(column);
+  
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(interfaces_Table_oid_ranges));
+
+  /* iterate over all possible OIDs to find the next one */
+  netif = netif_list;
+  while (netif != NULL) {
+    u32_t test_oid[LWIP_ARRAYSIZE(interfaces_Table_oid_ranges)];
+    test_oid[0] = netif_to_num(netif);
+
+    /* check generated OID: is it a candidate for the next one? */
+    snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(interfaces_Table_oid_ranges), netif);
+
+    netif = netif->next;
+  }
+
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* store netif pointer for subsequent operations (get/test/set) */
+    cell_instance->reference.ptr = /* (struct netif*) */state.reference;
+    return SNMP_ERR_NOERROR;
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+static s16_t
+interfaces_Table_get_value(struct snmp_node_instance* instance, void* value)
+{
+  struct netif *netif = (struct netif*)instance->reference.ptr;
+  u32_t* value_u32 = (u32_t*)value;
+  s32_t* value_s32 = (s32_t*)value;
+  u16_t value_len;
+
+  switch (SNMP_TABLE_GET_COLUMN_FROM_OID(instance->instance_oid.id))
+  {
+  case 1: /* ifIndex */
+    *value_s32 = netif_to_num(netif);
+    value_len = sizeof(*value_s32);
+    break;
+  case 2: /* ifDescr */
+    value_len = sizeof(netif->name);
+    MEMCPY(value, netif->name, value_len);
+    break;
+  case 3: /* ifType */
+    *value_s32 = netif->link_type;
+    value_len = sizeof(*value_s32);
+    break;
+  case 4: /* ifMtu */
+    *value_s32 = netif->mtu;
+    value_len = sizeof(*value_s32);
+    break;
+  case 5: /* ifSpeed */
+    *value_u32 = netif->link_speed;
+    value_len = sizeof(*value_u32);
+    break;
+  case 6: /* ifPhysAddress */
+    value_len = sizeof(netif->hwaddr);
+    MEMCPY(value, &netif->hwaddr, value_len);
+    break;
+  case 7: /* ifAdminStatus */
+    if (netif_is_up(netif)) {
+      *value_s32 = iftable_ifOperStatus_up;
+    } else {
+      *value_s32 = iftable_ifOperStatus_down;
+    }
+    value_len = sizeof(*value_s32);
+    break;
+  case 8: /* ifOperStatus */
+    if (netif_is_up(netif)) {
+      if (netif_is_link_up(netif)) {
+        *value_s32 = iftable_ifAdminStatus_up;
+      } else {
+        *value_s32 = iftable_ifAdminStatus_lowerLayerDown;
+      }
+    } else {
+      *value_s32 = iftable_ifAdminStatus_down;
+    }
+    value_len = sizeof(*value_s32);
+    break;
+  case 9: /* ifLastChange */
+    *value_u32 = netif->ts;
+    value_len = sizeof(*value_u32);
+    break;
+  case 10: /* ifInOctets */
+    *value_u32 = netif->mib2_counters.ifinoctets;
+    value_len = sizeof(*value_u32);
+    break;
+  case 11: /* ifInUcastPkts */
+    *value_u32 = netif->mib2_counters.ifinucastpkts;
+    value_len = sizeof(*value_u32);
+    break;
+  case 12: /* ifInNUcastPkts */
+    *value_u32 = netif->mib2_counters.ifinnucastpkts;
+    value_len = sizeof(*value_u32);
+    break;
+  case 13: /* ifInDiscards */
+    *value_u32 = netif->mib2_counters.ifindiscards;
+    value_len = sizeof(*value_u32);
+    break;
+  case 14: /* ifInErrors */
+    *value_u32 = netif->mib2_counters.ifinerrors;
+    value_len = sizeof(*value_u32);
+    break;
+  case 15: /* ifInUnkownProtos */
+    *value_u32 = netif->mib2_counters.ifinunknownprotos;
+    value_len = sizeof(*value_u32);
+    break;
+  case 16: /* ifOutOctets */
+    *value_u32 = netif->mib2_counters.ifoutoctets;
+    value_len = sizeof(*value_u32);
+    break;
+  case 17: /* ifOutUcastPkts */
+    *value_u32 = netif->mib2_counters.ifoutucastpkts;
+    value_len = sizeof(*value_u32);
+    break;
+  case 18: /* ifOutNUcastPkts */
+    *value_u32 = netif->mib2_counters.ifoutnucastpkts;
+    value_len = sizeof(*value_u32);
+    break;
+  case 19: /* ifOutDiscarts */
+    *value_u32 = netif->mib2_counters.ifoutdiscards;
+    value_len = sizeof(*value_u32);
+    break;
+  case 20: /* ifOutErrors */
+    *value_u32 = netif->mib2_counters.ifouterrors;
+    value_len = sizeof(*value_u32);
+    break;
+  case 21: /* ifOutQLen */
+    *value_u32 = iftable_ifOutQLen;
+    value_len = sizeof(*value_u32);
+    break;
+  /** @note returning zeroDotZero (0.0) no media specific MIB support */
+  case 22: /* ifSpecific */
+    value_len = snmp_zero_dot_zero.len * sizeof(u32_t);
+    MEMCPY(value, snmp_zero_dot_zero.id, value_len);
+    break;
+  default:
+    return 0;
+  }
+
+  return value_len;
+}
+
+#if !SNMP_SAFE_REQUESTS
+
+static snmp_err_t
+interfaces_Table_set_test(struct snmp_node_instance* instance, u16_t len, void *value)
+{
+  s32_t *sint_ptr = (s32_t*)value;
+
+  /* stack should never call this method for another column,
+  because all other columns are set to readonly */
+  LWIP_ASSERT("Invalid column", (SNMP_TABLE_GET_COLUMN_FROM_OID(instance->instance_oid.id) == 7));
+  LWIP_UNUSED_ARG(len);
+
+  if (*sint_ptr == 1 || *sint_ptr == 2)
+  {
+    return SNMP_ERR_NOERROR;
+  }
+    
+  return SNMP_ERR_WRONGVALUE;
+}
+
+static snmp_err_t
+interfaces_Table_set_value(struct snmp_node_instance* instance, u16_t len, void *value)
+{
+  struct netif *netif = (struct netif*)instance->reference.ptr;
+  s32_t *sint_ptr = (s32_t*)value;
+
+  /* stack should never call this method for another column,
+  because all other columns are set to readonly */
+  LWIP_ASSERT("Invalid column", (SNMP_TABLE_GET_COLUMN_FROM_OID(instance->instance_oid.id) == 7));
+  LWIP_UNUSED_ARG(len);
+
+  if (*sint_ptr == 1) {
+    netif_set_up(netif);
+  } else if (*sint_ptr == 2) {
+    netif_set_down(netif);
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+#endif /* SNMP_SAFE_REQUESTS */
+
+static const struct snmp_scalar_node interfaces_Number = SNMP_SCALAR_CREATE_NODE_READONLY(1, SNMP_ASN1_TYPE_INTEGER, interfaces_get_value);
+
+static const struct snmp_table_col_def interfaces_Table_columns[] = {
+  {  1, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifIndex */
+  {  2, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY }, /* ifDescr */
+  {  3, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifType */
+  {  4, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifMtu */
+  {  5, SNMP_ASN1_TYPE_GAUGE,        SNMP_NODE_INSTANCE_READ_ONLY }, /* ifSpeed */
+  {  6, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY }, /* ifPhysAddress */
+#if !SNMP_SAFE_REQUESTS
+  {  7, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_WRITE }, /* ifAdminStatus */
+#else
+  {  7, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifAdminStatus */
+#endif
+  {  8, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifOperStatus */
+  {  9, SNMP_ASN1_TYPE_TIMETICKS,    SNMP_NODE_INSTANCE_READ_ONLY }, /* ifLastChange */
+  { 10, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifInOctets */
+  { 11, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifInUcastPkts */
+  { 12, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifInNUcastPkts */
+  { 13, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifInDiscarts */
+  { 14, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifInErrors */
+  { 15, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifInUnkownProtos */
+  { 16, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifOutOctets */
+  { 17, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifOutUcastPkts */
+  { 18, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifOutNUcastPkts */
+  { 19, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifOutDiscarts */
+  { 20, SNMP_ASN1_TYPE_COUNTER,      SNMP_NODE_INSTANCE_READ_ONLY }, /* ifOutErrors */
+  { 21, SNMP_ASN1_TYPE_GAUGE,        SNMP_NODE_INSTANCE_READ_ONLY }, /* ifOutQLen */
+  { 22, SNMP_ASN1_TYPE_OBJECT_ID,    SNMP_NODE_INSTANCE_READ_ONLY }  /* ifSpecific */
+};
+
+#if !SNMP_SAFE_REQUESTS
+static const struct snmp_table_node interfaces_Table = SNMP_TABLE_CREATE(
+  2, interfaces_Table_columns, 
+  interfaces_Table_get_cell_instance, interfaces_Table_get_next_cell_instance, 
+  interfaces_Table_get_value, interfaces_Table_set_test, interfaces_Table_set_value);
+#else
+static const struct snmp_table_node interfaces_Table = SNMP_TABLE_CREATE(
+  2, interfaces_Table_columns, 
+  interfaces_Table_get_cell_instance, interfaces_Table_get_next_cell_instance, 
+  interfaces_Table_get_value, NULL, NULL);
+#endif
+
+/* the following nodes access variables in LWIP stack from SNMP worker thread and must therefore be synced to LWIP (TCPIP) thread */ 
+CREATE_LWIP_SYNC_NODE(1, interfaces_Number)
+CREATE_LWIP_SYNC_NODE(2, interfaces_Table)
+
+static const struct snmp_node* const interface_nodes[] = {
+  &SYNC_NODE_NAME(interfaces_Number).node.node,
+  &SYNC_NODE_NAME(interfaces_Table).node.node
+};
+
+const struct snmp_tree_node snmp_mib2_interface_root = SNMP_CREATE_TREE_NODE(2, interface_nodes);
+
+#endif /* LWIP_SNMP && SNMP_LWIP_MIB2 */

ext/lwip/src/apps/snmp/snmp_mib2_ip.c

@@ -0,0 +1,743 @@
+/**
+ * @file
+ * Management Information Base II (RFC1213) IP objects and functions.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ */
+
+#include "lwip/snmp.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_mib2.h"
+#include "lwip/apps/snmp_table.h"
+#include "lwip/apps/snmp_scalar.h"
+#include "lwip/stats.h"
+#include "lwip/netif.h"
+#include "lwip/ip.h"
+#include "lwip/etharp.h"
+
+#if LWIP_SNMP && SNMP_LWIP_MIB2
+
+#if SNMP_USE_NETCONN
+#define SYNC_NODE_NAME(node_name) node_name ## _synced
+#define CREATE_LWIP_SYNC_NODE(oid, node_name) \
+   static const struct snmp_threadsync_node node_name ## _synced = SNMP_CREATE_THREAD_SYNC_NODE(oid, &node_name.node, &snmp_mib2_lwip_locks);
+#else
+#define SYNC_NODE_NAME(node_name) node_name
+#define CREATE_LWIP_SYNC_NODE(oid, node_name)
+#endif
+
+#if LWIP_IPV4
+/* --- ip .1.3.6.1.2.1.4 ----------------------------------------------------- */
+
+static s16_t 
+ip_get_value(struct snmp_node_instance* instance, void* value)
+{
+  s32_t* sint_ptr = (s32_t*)value;
+  u32_t* uint_ptr = (u32_t*)value;
+
+  switch (instance->node->oid) {
+  case 1: /* ipForwarding */
+#if IP_FORWARD
+    /* forwarding */
+    *sint_ptr = 1;
+#else
+    /* not-forwarding */
+    *sint_ptr = 2;
+#endif
+    return sizeof(*sint_ptr);
+  case 2: /* ipDefaultTTL */
+    *sint_ptr = IP_DEFAULT_TTL;
+    return sizeof(*sint_ptr);
+  case 3: /* ipInReceives */
+    *uint_ptr = STATS_GET(mib2.ipinreceives);
+    return sizeof(*uint_ptr);
+  case 4: /* ipInHdrErrors */
+    *uint_ptr = STATS_GET(mib2.ipinhdrerrors);
+    return sizeof(*uint_ptr);
+  case 5: /* ipInAddrErrors */
+    *uint_ptr = STATS_GET(mib2.ipinaddrerrors);
+    return sizeof(*uint_ptr);
+  case 6: /* ipForwDatagrams */
+    *uint_ptr = STATS_GET(mib2.ipforwdatagrams);
+    return sizeof(*uint_ptr);
+  case 7: /* ipInUnknownProtos */
+    *uint_ptr = STATS_GET(mib2.ipinunknownprotos);
+    return sizeof(*uint_ptr);
+  case 8: /* ipInDiscards */
+    *uint_ptr = STATS_GET(mib2.ipindiscards);
+    return sizeof(*uint_ptr);
+  case 9: /* ipInDelivers */
+    *uint_ptr = STATS_GET(mib2.ipindelivers);
+    return sizeof(*uint_ptr);
+  case 10: /* ipOutRequests */
+    *uint_ptr = STATS_GET(mib2.ipoutrequests);
+    return sizeof(*uint_ptr);
+  case 11: /* ipOutDiscards */
+    *uint_ptr = STATS_GET(mib2.ipoutdiscards);
+    return sizeof(*uint_ptr);
+  case 12: /* ipOutNoRoutes */
+    *uint_ptr = STATS_GET(mib2.ipoutnoroutes);
+    return sizeof(*uint_ptr);
+  case 13: /* ipReasmTimeout */
+#if IP_REASSEMBLY
+    *sint_ptr = IP_REASS_MAXAGE;
+#else
+    *sint_ptr = 0;
+#endif
+    return sizeof(*sint_ptr);
+  case 14: /* ipReasmReqds */
+    *uint_ptr = STATS_GET(mib2.ipreasmreqds);
+    return sizeof(*uint_ptr);
+  case 15: /* ipReasmOKs */
+    *uint_ptr = STATS_GET(mib2.ipreasmoks);
+    return sizeof(*uint_ptr);
+  case 16: /* ipReasmFails */
+    *uint_ptr = STATS_GET(mib2.ipreasmfails);
+    return sizeof(*uint_ptr);
+  case 17: /* ipFragOKs */
+    *uint_ptr = STATS_GET(mib2.ipfragoks);
+    return sizeof(*uint_ptr);
+  case 18: /* ipFragFails */
+    *uint_ptr = STATS_GET(mib2.ipfragfails);
+    return sizeof(*uint_ptr);
+  case 19: /* ipFragCreates */
+    *uint_ptr = STATS_GET(mib2.ipfragcreates);
+    return sizeof(*uint_ptr);
+  case 23: /* ipRoutingDiscards: not supported -> always 0 */
+    *uint_ptr = 0;
+    return sizeof(*uint_ptr);
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("ip_get_value(): unknown id: %"S32_F"\n", instance->node->oid));
+    break;
+  }
+
+  return 0;
+}
+
+/**
+ * Test ip object value before setting.
+ *
+ * @param od is the object definition
+ * @param len return value space (in bytes)
+ * @param value points to (varbind) space to copy value from.
+ *
+ * @note we allow set if the value matches the hardwired value,
+ *   otherwise return badvalue.
+ */
+static snmp_err_t
+ip_set_test(struct snmp_node_instance* instance, u16_t len, void *value)
+{
+  snmp_err_t ret = SNMP_ERR_WRONGVALUE;
+  s32_t *sint_ptr = (s32_t*)value;
+
+  LWIP_UNUSED_ARG(len);
+  switch (instance->node->oid) {
+  case 1: /* ipForwarding */
+#if IP_FORWARD
+    /* forwarding */
+    if (*sint_ptr == 1)
+#else
+    /* not-forwarding */
+    if (*sint_ptr == 2)
+#endif
+    {
+      ret = SNMP_ERR_NOERROR;
+    }
+    break;
+  case 2: /* ipDefaultTTL */
+    if (*sint_ptr == IP_DEFAULT_TTL) {
+      ret = SNMP_ERR_NOERROR;
+    }
+    break;
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("ip_set_test(): unknown id: %"S32_F"\n", instance->node->oid));
+    break;
+  }
+
+  return ret;
+}
+
+static snmp_err_t
+ip_set_value(struct snmp_node_instance* instance, u16_t len, void *value)
+{
+  LWIP_UNUSED_ARG(instance);
+  LWIP_UNUSED_ARG(len);
+  LWIP_UNUSED_ARG(value);
+  /* nothing to do here because in set_test we only accept values being the same as our own stored value -> no need to store anything */
+  return SNMP_ERR_NOERROR;
+}
+
+/* --- ipAddrTable --- */
+
+/* list of allowed value ranges for incoming OID */
+static const struct snmp_oid_range ip_AddrTable_oid_ranges[] = {
+  { 0, 0xff }, /* IP A */
+  { 0, 0xff }, /* IP B */
+  { 0, 0xff }, /* IP C */
+  { 0, 0xff }  /* IP D */
+};
+
+static snmp_err_t
+ip_AddrTable_get_cell_value_core(struct netif *netif, const u32_t* column, union snmp_variant_value* value, u32_t* value_len)
+{
+  LWIP_UNUSED_ARG(value_len);
+
+  switch (*column) {
+  case 1: /* ipAdEntAddr */
+    value->u32 = netif_ip4_addr(netif)->addr;
+    break;
+  case 2: /* ipAdEntIfIndex */
+    value->u32 = netif_to_num(netif);
+    break;
+  case 3: /* ipAdEntNetMask */
+    value->u32 = netif_ip4_netmask(netif)->addr;
+    break;
+  case 4: /* ipAdEntBcastAddr */
+    /* lwIP oddity, there's no broadcast
+       address in the netif we can rely on */
+    value->u32 = IPADDR_BROADCAST & 1;
+    break;
+  case 5: /* ipAdEntReasmMaxSize */
+#if IP_REASSEMBLY
+    /* @todo The theoretical maximum is IP_REASS_MAX_PBUFS * size of the pbufs,
+     * but only if receiving one fragmented packet at a time.
+     * The current solution is to calculate for 2 simultaneous packets...
+     */
+    value->u32 = (IP_HLEN + ((IP_REASS_MAX_PBUFS/2) *
+        (PBUF_POOL_BUFSIZE - PBUF_LINK_ENCAPSULATION_HLEN - PBUF_LINK_HLEN - IP_HLEN)));
+#else
+    /** @todo returning MTU would be a bad thing and
+        returning a wild guess like '576' isn't good either */
+    value->u32 = 0;
+#endif
+    break;
+  default:
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static snmp_err_t
+ip_AddrTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, union snmp_variant_value* value, u32_t* value_len)
+{
+  ip4_addr_t ip;
+  struct netif *netif;
+
+  /* check if incoming OID length and if values are in plausible range */
+  if (!snmp_oid_in_range(row_oid, row_oid_len, ip_AddrTable_oid_ranges, LWIP_ARRAYSIZE(ip_AddrTable_oid_ranges))) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* get IP from incoming OID */
+  snmp_oid_to_ip4(&row_oid[0], &ip); /* we know it succeeds because of oid_in_range check above */
+
+  /* find netif with requested ip */
+  netif = netif_list;
+  while (netif != NULL) {
+    if (ip4_addr_cmp(&ip, netif_ip4_addr(netif))) {
+      /* fill in object properties */
+      return ip_AddrTable_get_cell_value_core(netif, column, value, value_len);
+    }
+
+    netif = netif->next;
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+static snmp_err_t
+ip_AddrTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_obj_id* row_oid, union snmp_variant_value* value, u32_t* value_len)
+{
+  struct netif *netif;
+  struct snmp_next_oid_state state;
+  u32_t result_temp[LWIP_ARRAYSIZE(ip_AddrTable_oid_ranges)];
+
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(ip_AddrTable_oid_ranges));
+
+  /* iterate over all possible OIDs to find the next one */
+  netif = netif_list;
+  while (netif != NULL) {
+    u32_t test_oid[LWIP_ARRAYSIZE(ip_AddrTable_oid_ranges)];
+    snmp_ip4_to_oid(netif_ip4_addr(netif), &test_oid[0]);
+
+    /* check generated OID: is it a candidate for the next one? */
+    snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(ip_AddrTable_oid_ranges), netif);
+
+    netif = netif->next;
+  }
+
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* fill in object properties */
+    return ip_AddrTable_get_cell_value_core((struct netif*)state.reference, column, value, value_len);
+  }
+  
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+/* --- ipRouteTable --- */
+
+/* list of allowed value ranges for incoming OID */
+static const struct snmp_oid_range ip_RouteTable_oid_ranges[] = {
+  { 0, 0xff }, /* IP A */
+  { 0, 0xff }, /* IP B */
+  { 0, 0xff }, /* IP C */
+  { 0, 0xff }, /* IP D */
+};
+
+static snmp_err_t
+ip_RouteTable_get_cell_value_core(struct netif *netif, u8_t default_route, const u32_t* column, union snmp_variant_value* value, u32_t* value_len)
+{
+  switch (*column) {
+  case 1: /* ipRouteDest */
+    if (default_route) {
+       /* default rte has 0.0.0.0 dest */
+      value->u32 = IP4_ADDR_ANY->addr;
+    } else {
+      /* netifs have netaddress dest */
+      ip4_addr_t tmp;
+      ip4_addr_get_network(&tmp, netif_ip4_addr(netif), netif_ip4_netmask(netif));
+      value->u32 = tmp.addr;
+    }
+    break;
+  case 2: /* ipRouteIfIndex */
+    value->u32 = netif_to_num(netif);
+    break;
+  case 3: /* ipRouteMetric1 */
+    if (default_route) {
+      value->s32 = 1; /* default */
+    } else {
+      value->s32 = 0; /* normal */
+    }
+    break;
+  case 4: /* ipRouteMetric2 */
+  case 5: /* ipRouteMetric3 */
+  case 6: /* ipRouteMetric4 */
+    value->s32 = -1; /* none */
+    break;
+  case 7: /* ipRouteNextHop */
+    if (default_route) {
+      /* default rte: gateway */
+      value->u32 = netif_ip4_gw(netif)->addr;
+    } else {
+      /* other rtes: netif ip_addr  */
+      value->u32 = netif_ip4_addr(netif)->addr;
+    }
+    break;
+  case 8: /* ipRouteType */
+    if (default_route) {
+      /* default rte is indirect */
+      value->u32 = 4; /* indirect */
+    } else {
+      /* other rtes are direct */
+      value->u32 = 3; /* direct */
+    }
+    break;
+  case 9: /* ipRouteProto */
+    /* locally defined routes */
+    value->u32 = 2; /* local */
+    break;
+  case 10: /* ipRouteAge */
+    /* @todo (sysuptime - timestamp last change) / 100 */
+    value->u32 = 0;
+    break;
+  case 11: /* ipRouteMask */
+    if (default_route) {
+      /* default rte use 0.0.0.0 mask */
+      value->u32 = IP4_ADDR_ANY->addr;
+    } else {
+      /* other rtes use netmask */
+      value->u32 = netif_ip4_netmask(netif)->addr;
+    }
+    break;
+  case 12: /* ipRouteMetric5 */
+    value->s32 = -1; /* none */
+    break;
+  case 13: /* ipRouteInfo */
+    value->const_ptr = snmp_zero_dot_zero.id;
+    *value_len = snmp_zero_dot_zero.len * sizeof(u32_t);
+    break;
+  default:
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static snmp_err_t
+ip_RouteTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, union snmp_variant_value* value, u32_t* value_len)
+{
+  ip4_addr_t test_ip;
+  struct netif *netif;
+
+  /* check if incoming OID length and if values are in plausible range */
+  if (!snmp_oid_in_range(row_oid, row_oid_len, ip_RouteTable_oid_ranges, LWIP_ARRAYSIZE(ip_RouteTable_oid_ranges))) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* get IP and port from incoming OID */
+  snmp_oid_to_ip4(&row_oid[0], &test_ip); /* we know it succeeds because of oid_in_range check above */
+
+  /* default route is on default netif */
+  if (ip4_addr_isany_val(test_ip) && (netif_default != NULL)) {
+    /* fill in object properties */
+    return ip_RouteTable_get_cell_value_core(netif_default, 1, column, value, value_len);
+  }
+
+  /* find netif with requested route */
+  netif = netif_list;
+  while (netif != NULL) {
+    ip4_addr_t dst;
+    ip4_addr_get_network(&dst, netif_ip4_addr(netif), netif_ip4_netmask(netif));
+
+    if (ip4_addr_cmp(&dst, &test_ip)) {
+      /* fill in object properties */
+      return ip_RouteTable_get_cell_value_core(netif, 0, column, value, value_len);
+    }
+
+    netif = netif->next;
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+static snmp_err_t
+ip_RouteTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_obj_id* row_oid, union snmp_variant_value* value, u32_t* value_len)
+{
+  struct netif *netif;
+  struct snmp_next_oid_state state;
+  u32_t result_temp[LWIP_ARRAYSIZE(ip_RouteTable_oid_ranges)];
+  u32_t test_oid[LWIP_ARRAYSIZE(ip_RouteTable_oid_ranges)];
+
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(ip_RouteTable_oid_ranges));
+
+  /* check default route */
+  if (netif_default != NULL) {
+    snmp_ip4_to_oid(IP4_ADDR_ANY, &test_oid[0]);
+    snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(ip_RouteTable_oid_ranges), netif_default);
+  }
+
+  /* iterate over all possible OIDs to find the next one */
+  netif = netif_list;
+  while (netif != NULL) {
+    ip4_addr_t dst;
+    ip4_addr_get_network(&dst, netif_ip4_addr(netif), netif_ip4_netmask(netif));
+
+    /* check generated OID: is it a candidate for the next one? */
+    if (!ip4_addr_isany_val(dst)) {
+      snmp_ip4_to_oid(&dst, &test_oid[0]);
+      snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(ip_RouteTable_oid_ranges), netif);
+    }
+    
+    netif = netif->next;
+  }
+
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    ip4_addr_t dst;
+    snmp_oid_to_ip4(&result_temp[0], &dst);
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* fill in object properties */
+    return ip_RouteTable_get_cell_value_core((struct netif*)state.reference, ip4_addr_isany_val(dst), column, value, value_len);
+  } else {
+    /* not found */
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+}
+
+#if LWIP_ARP && LWIP_IPV4
+/* --- ipNetToMediaTable --- */
+
+/* list of allowed value ranges for incoming OID */
+static const struct snmp_oid_range ip_NetToMediaTable_oid_ranges[] = {
+  { 1, 0xff }, /* IfIndex */
+  { 0, 0xff }, /* IP A    */
+  { 0, 0xff }, /* IP B    */
+  { 0, 0xff }, /* IP C    */
+  { 0, 0xff }  /* IP D    */
+};
+
+static snmp_err_t
+ip_NetToMediaTable_get_cell_value_core(u8_t arp_table_index, const u32_t* column, union snmp_variant_value* value, u32_t* value_len)
+{
+  ip4_addr_t *ip;
+  struct netif *netif;
+  struct eth_addr *ethaddr;
+
+  etharp_get_entry(arp_table_index, &ip, &netif, &ethaddr);
+
+  /* value */
+  switch (*column) {
+  case 1: /* atIfIndex / ipNetToMediaIfIndex */
+    value->u32 = netif_to_num(netif);
+    break;
+  case 2: /* atPhysAddress / ipNetToMediaPhysAddress */
+    value->ptr = ethaddr;
+    *value_len = sizeof(*ethaddr);
+    break;
+  case 3: /* atNetAddress / ipNetToMediaNetAddress */
+    value->u32 = ip->addr;
+    break;
+  case 4: /* ipNetToMediaType */
+    value->u32 = 3; /* dynamic*/
+    break;
+  default:
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static snmp_err_t
+ip_NetToMediaTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, union snmp_variant_value* value, u32_t* value_len)
+{
+  ip4_addr_t ip_in;
+  u8_t netif_index;
+  u8_t i;
+
+  /* check if incoming OID length and if values are in plausible range */
+  if (!snmp_oid_in_range(row_oid, row_oid_len, ip_NetToMediaTable_oid_ranges, LWIP_ARRAYSIZE(ip_NetToMediaTable_oid_ranges))) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* get IP from incoming OID */
+  netif_index = (u8_t)row_oid[0];
+  snmp_oid_to_ip4(&row_oid[1], &ip_in); /* we know it succeeds because of oid_in_range check above */
+
+  /* find requested entry */
+  for (i=0; i<ARP_TABLE_SIZE; i++) {
+    ip4_addr_t *ip;
+    struct netif *netif;
+    struct eth_addr *ethaddr;
+
+    if (etharp_get_entry(i, &ip, &netif, &ethaddr)) {
+      if ((netif_index == netif_to_num(netif)) && ip4_addr_cmp(&ip_in, ip)) {
+        /* fill in object properties */
+        return ip_NetToMediaTable_get_cell_value_core(i, column, value, value_len);
+      }
+    }
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+static snmp_err_t
+ip_NetToMediaTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_obj_id* row_oid, union snmp_variant_value* value, u32_t* value_len)
+{
+  u8_t i;
+  struct snmp_next_oid_state state;
+  u32_t result_temp[LWIP_ARRAYSIZE(ip_NetToMediaTable_oid_ranges)];
+
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(ip_NetToMediaTable_oid_ranges));
+
+  /* iterate over all possible OIDs to find the next one */
+  for (i=0; i<ARP_TABLE_SIZE; i++) {
+    ip4_addr_t *ip;
+    struct netif *netif;
+    struct eth_addr *ethaddr;
+
+    if (etharp_get_entry(i, &ip, &netif, &ethaddr)) {
+      u32_t test_oid[LWIP_ARRAYSIZE(ip_NetToMediaTable_oid_ranges)];
+
+      test_oid[0] = netif_to_num(netif);
+      snmp_ip4_to_oid(ip, &test_oid[1]);
+
+      /* check generated OID: is it a candidate for the next one? */
+      snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(ip_NetToMediaTable_oid_ranges), (void*)(size_t)i);
+    }
+  }
+
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* fill in object properties */
+    return ip_NetToMediaTable_get_cell_value_core((u8_t)(size_t)state.reference, column, value, value_len);
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+#endif /* LWIP_ARP && LWIP_IPV4 */
+
+static const struct snmp_scalar_node ip_Forwarding      = SNMP_SCALAR_CREATE_NODE(1, SNMP_NODE_INSTANCE_READ_WRITE, SNMP_ASN1_TYPE_INTEGER, ip_get_value, ip_set_test, ip_set_value);
+static const struct snmp_scalar_node ip_DefaultTTL      = SNMP_SCALAR_CREATE_NODE(2, SNMP_NODE_INSTANCE_READ_WRITE, SNMP_ASN1_TYPE_INTEGER, ip_get_value, ip_set_test, ip_set_value);
+static const struct snmp_scalar_node ip_InReceives      = SNMP_SCALAR_CREATE_NODE_READONLY(3, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_InHdrErrors     = SNMP_SCALAR_CREATE_NODE_READONLY(4, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_InAddrErrors    = SNMP_SCALAR_CREATE_NODE_READONLY(5, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_ForwDatagrams   = SNMP_SCALAR_CREATE_NODE_READONLY(6, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_InUnknownProtos = SNMP_SCALAR_CREATE_NODE_READONLY(7, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_InDiscards      = SNMP_SCALAR_CREATE_NODE_READONLY(8, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_InDelivers      = SNMP_SCALAR_CREATE_NODE_READONLY(9, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_OutRequests     = SNMP_SCALAR_CREATE_NODE_READONLY(10, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_OutDiscards     = SNMP_SCALAR_CREATE_NODE_READONLY(11, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_OutNoRoutes     = SNMP_SCALAR_CREATE_NODE_READONLY(12, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_ReasmTimeout    = SNMP_SCALAR_CREATE_NODE_READONLY(13, SNMP_ASN1_TYPE_INTEGER, ip_get_value);
+static const struct snmp_scalar_node ip_ReasmReqds      = SNMP_SCALAR_CREATE_NODE_READONLY(14, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_ReasmOKs        = SNMP_SCALAR_CREATE_NODE_READONLY(15, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_ReasmFails      = SNMP_SCALAR_CREATE_NODE_READONLY(16, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_FragOKs         = SNMP_SCALAR_CREATE_NODE_READONLY(17, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_FragFails       = SNMP_SCALAR_CREATE_NODE_READONLY(18, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_FragCreates     = SNMP_SCALAR_CREATE_NODE_READONLY(19, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+static const struct snmp_scalar_node ip_RoutingDiscards = SNMP_SCALAR_CREATE_NODE_READONLY(23, SNMP_ASN1_TYPE_COUNTER, ip_get_value);
+
+static const struct snmp_table_simple_col_def ip_AddrTable_columns[] = {
+  { 1, SNMP_ASN1_TYPE_IPADDR,  SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipAdEntAddr */
+  { 2, SNMP_ASN1_TYPE_INTEGER, SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipAdEntIfIndex */
+  { 3, SNMP_ASN1_TYPE_IPADDR,  SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipAdEntNetMask */
+  { 4, SNMP_ASN1_TYPE_INTEGER, SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipAdEntBcastAddr */
+  { 5, SNMP_ASN1_TYPE_INTEGER, SNMP_VARIANT_VALUE_TYPE_U32 }  /* ipAdEntReasmMaxSize */
+};
+
+static const struct snmp_table_simple_node ip_AddrTable = SNMP_TABLE_CREATE_SIMPLE(20, ip_AddrTable_columns, ip_AddrTable_get_cell_value, ip_AddrTable_get_next_cell_instance_and_value);
+
+static const struct snmp_table_simple_col_def ip_RouteTable_columns[] = {
+  {  1, SNMP_ASN1_TYPE_IPADDR,    SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipRouteDest */
+  {  2, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipRouteIfIndex */
+  {  3, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_S32 }, /* ipRouteMetric1 */
+  {  4, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_S32 }, /* ipRouteMetric2 */
+  {  5, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_S32 }, /* ipRouteMetric3 */
+  {  6, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_S32 }, /* ipRouteMetric4 */
+  {  7, SNMP_ASN1_TYPE_IPADDR,    SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipRouteNextHop */
+  {  8, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipRouteType */
+  {  9, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipRouteProto */
+  { 10, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipRouteAge */
+  { 11, SNMP_ASN1_TYPE_IPADDR,    SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipRouteMask */
+  { 12, SNMP_ASN1_TYPE_INTEGER,   SNMP_VARIANT_VALUE_TYPE_S32 }, /* ipRouteMetric5 */
+  { 13, SNMP_ASN1_TYPE_OBJECT_ID, SNMP_VARIANT_VALUE_TYPE_PTR }  /* ipRouteInfo */
+};
+
+static const struct snmp_table_simple_node ip_RouteTable = SNMP_TABLE_CREATE_SIMPLE(21, ip_RouteTable_columns, ip_RouteTable_get_cell_value, ip_RouteTable_get_next_cell_instance_and_value);
+#endif /* LWIP_IPV4 */
+
+#if LWIP_ARP && LWIP_IPV4
+static const struct snmp_table_simple_col_def ip_NetToMediaTable_columns[] = {
+  {  1, SNMP_ASN1_TYPE_INTEGER,      SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipNetToMediaIfIndex */
+  {  2, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_VARIANT_VALUE_TYPE_PTR }, /* ipNetToMediaPhysAddress */
+  {  3, SNMP_ASN1_TYPE_IPADDR,       SNMP_VARIANT_VALUE_TYPE_U32 }, /* ipNetToMediaNetAddress */
+  {  4, SNMP_ASN1_TYPE_INTEGER,      SNMP_VARIANT_VALUE_TYPE_U32 }  /* ipNetToMediaType */
+};
+
+static const struct snmp_table_simple_node ip_NetToMediaTable = SNMP_TABLE_CREATE_SIMPLE(22, ip_NetToMediaTable_columns, ip_NetToMediaTable_get_cell_value, ip_NetToMediaTable_get_next_cell_instance_and_value);
+#endif /* LWIP_ARP && LWIP_IPV4 */
+
+#if LWIP_IPV4
+/* the following nodes access variables in LWIP stack from SNMP worker thread and must therefore be synced to LWIP (TCPIP) thread */ 
+CREATE_LWIP_SYNC_NODE( 1, ip_Forwarding)
+CREATE_LWIP_SYNC_NODE( 2, ip_DefaultTTL)
+CREATE_LWIP_SYNC_NODE( 3, ip_InReceives)
+CREATE_LWIP_SYNC_NODE( 4, ip_InHdrErrors)
+CREATE_LWIP_SYNC_NODE( 5, ip_InAddrErrors)
+CREATE_LWIP_SYNC_NODE( 6, ip_ForwDatagrams)
+CREATE_LWIP_SYNC_NODE( 7, ip_InUnknownProtos)
+CREATE_LWIP_SYNC_NODE( 8, ip_InDiscards)
+CREATE_LWIP_SYNC_NODE( 9, ip_InDelivers)
+CREATE_LWIP_SYNC_NODE(10, ip_OutRequests)
+CREATE_LWIP_SYNC_NODE(11, ip_OutDiscards)
+CREATE_LWIP_SYNC_NODE(12, ip_OutNoRoutes)
+CREATE_LWIP_SYNC_NODE(13, ip_ReasmTimeout)
+CREATE_LWIP_SYNC_NODE(14, ip_ReasmReqds)
+CREATE_LWIP_SYNC_NODE(15, ip_ReasmOKs)
+CREATE_LWIP_SYNC_NODE(15, ip_ReasmFails)
+CREATE_LWIP_SYNC_NODE(17, ip_FragOKs)
+CREATE_LWIP_SYNC_NODE(18, ip_FragFails)
+CREATE_LWIP_SYNC_NODE(19, ip_FragCreates)
+CREATE_LWIP_SYNC_NODE(20, ip_AddrTable)
+CREATE_LWIP_SYNC_NODE(21, ip_RouteTable)
+#if LWIP_ARP
+CREATE_LWIP_SYNC_NODE(22, ip_NetToMediaTable)
+#endif /* LWIP_ARP */
+CREATE_LWIP_SYNC_NODE(23, ip_RoutingDiscards)
+
+static const struct snmp_node* const ip_nodes[] = {
+  &SYNC_NODE_NAME(ip_Forwarding).node.node,
+  &SYNC_NODE_NAME(ip_DefaultTTL).node.node,
+  &SYNC_NODE_NAME(ip_InReceives).node.node,
+  &SYNC_NODE_NAME(ip_InHdrErrors).node.node,
+  &SYNC_NODE_NAME(ip_InAddrErrors).node.node,
+  &SYNC_NODE_NAME(ip_ForwDatagrams).node.node,
+  &SYNC_NODE_NAME(ip_InUnknownProtos).node.node,
+  &SYNC_NODE_NAME(ip_InDiscards).node.node,
+  &SYNC_NODE_NAME(ip_InDelivers).node.node,
+  &SYNC_NODE_NAME(ip_OutRequests).node.node,
+  &SYNC_NODE_NAME(ip_OutDiscards).node.node,
+  &SYNC_NODE_NAME(ip_OutNoRoutes).node.node,
+  &SYNC_NODE_NAME(ip_ReasmTimeout).node.node,
+  &SYNC_NODE_NAME(ip_ReasmReqds).node.node,
+  &SYNC_NODE_NAME(ip_ReasmOKs).node.node,
+  &SYNC_NODE_NAME(ip_ReasmFails).node.node,
+  &SYNC_NODE_NAME(ip_FragOKs).node.node,
+  &SYNC_NODE_NAME(ip_FragFails).node.node,
+  &SYNC_NODE_NAME(ip_FragCreates).node.node,
+  &SYNC_NODE_NAME(ip_AddrTable).node.node,
+  &SYNC_NODE_NAME(ip_RouteTable).node.node,
+#if LWIP_ARP
+  &SYNC_NODE_NAME(ip_NetToMediaTable).node.node,
+#endif /* LWIP_ARP */
+  &SYNC_NODE_NAME(ip_RoutingDiscards).node.node
+};
+
+const struct snmp_tree_node snmp_mib2_ip_root = SNMP_CREATE_TREE_NODE(4, ip_nodes);
+#endif /* LWIP_IPV4 */
+
+/* --- at .1.3.6.1.2.1.3 ----------------------------------------------------- */
+
+#if LWIP_ARP && LWIP_IPV4
+/* at node table is a subset of ip_nettomedia table (same rows but less columns) */
+static const struct snmp_table_simple_col_def at_Table_columns[] = {
+  { 1, SNMP_ASN1_TYPE_INTEGER,      SNMP_VARIANT_VALUE_TYPE_U32 }, /* atIfIndex */
+  { 2, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_VARIANT_VALUE_TYPE_PTR }, /* atPhysAddress */
+  { 3, SNMP_ASN1_TYPE_IPADDR,       SNMP_VARIANT_VALUE_TYPE_U32 }  /* atNetAddress */
+};
+
+static const struct snmp_table_simple_node at_Table = SNMP_TABLE_CREATE_SIMPLE(1, at_Table_columns, ip_NetToMediaTable_get_cell_value, ip_NetToMediaTable_get_next_cell_instance_and_value);
+
+/* the following nodes access variables in LWIP stack from SNMP worker thread and must therefore be synced to LWIP (TCPIP) thread */ 
+CREATE_LWIP_SYNC_NODE(1, at_Table)
+
+static const struct snmp_node* const at_nodes[] = {
+  &SYNC_NODE_NAME(at_Table).node.node
+};
+
+const struct snmp_tree_node snmp_mib2_at_root = SNMP_CREATE_TREE_NODE(3, at_nodes);
+#endif /* LWIP_ARP && LWIP_IPV4 */
+
+#endif /* LWIP_SNMP && SNMP_LWIP_MIB2 */

ext/lwip/src/apps/snmp/snmp_mib2_snmp.c

@@ -0,0 +1,227 @@
+/**
+ * @file
+ * Management Information Base II (RFC1213) SNMP objects and functions.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ */
+
+#include "lwip/snmp.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_mib2.h"
+#include "lwip/apps/snmp_scalar.h"
+
+#if LWIP_SNMP && SNMP_LWIP_MIB2
+
+#define MIB2_AUTH_TRAPS_ENABLED  1
+#define MIB2_AUTH_TRAPS_DISABLED 2
+
+/* --- snmp .1.3.6.1.2.1.11 ----------------------------------------------------- */
+static s16_t
+snmp_get_value(const struct snmp_scalar_array_node_def *node, void *value)
+{
+  u32_t *uint_ptr = (u32_t*)value;
+  switch (node->oid) {
+  case 1: /* snmpInPkts */
+    *uint_ptr = snmp_stats.inpkts;
+    break;
+  case 2: /* snmpOutPkts */
+    *uint_ptr = snmp_stats.outpkts;
+    break;
+  case 3: /* snmpInBadVersions */
+    *uint_ptr = snmp_stats.inbadversions;
+    break;
+  case 4: /* snmpInBadCommunityNames */
+    *uint_ptr = snmp_stats.inbadcommunitynames;
+    break;
+  case 5: /* snmpInBadCommunityUses */
+    *uint_ptr = snmp_stats.inbadcommunityuses;
+    break;
+  case 6: /* snmpInASNParseErrs */
+    *uint_ptr = snmp_stats.inasnparseerrs;
+    break;
+  case 8: /* snmpInTooBigs */
+    *uint_ptr = snmp_stats.intoobigs;
+    break;
+  case 9: /* snmpInNoSuchNames */
+    *uint_ptr = snmp_stats.innosuchnames;
+    break;
+  case 10: /* snmpInBadValues */
+    *uint_ptr = snmp_stats.inbadvalues;
+    break;
+  case 11: /* snmpInReadOnlys */
+    *uint_ptr = snmp_stats.inreadonlys;
+    break;
+  case 12: /* snmpInGenErrs */
+    *uint_ptr = snmp_stats.ingenerrs;
+    break;
+  case 13: /* snmpInTotalReqVars */
+    *uint_ptr = snmp_stats.intotalreqvars;
+    break;
+  case 14: /* snmpInTotalSetVars */
+    *uint_ptr = snmp_stats.intotalsetvars;
+    break;
+  case 15: /* snmpInGetRequests */
+    *uint_ptr = snmp_stats.ingetrequests;
+    break;
+  case 16: /* snmpInGetNexts */
+    *uint_ptr = snmp_stats.ingetnexts;
+    break;
+  case 17: /* snmpInSetRequests */
+    *uint_ptr = snmp_stats.insetrequests;
+    break;
+  case 18: /* snmpInGetResponses */
+    *uint_ptr = snmp_stats.ingetresponses;
+    break;
+  case 19: /* snmpInTraps */
+    *uint_ptr = snmp_stats.intraps;
+    break;
+  case 20: /* snmpOutTooBigs */
+    *uint_ptr = snmp_stats.outtoobigs;
+    break;
+  case 21: /* snmpOutNoSuchNames */
+    *uint_ptr = snmp_stats.outnosuchnames;
+    break;
+  case 22: /* snmpOutBadValues */
+    *uint_ptr = snmp_stats.outbadvalues;
+    break;
+  case 24: /* snmpOutGenErrs */
+    *uint_ptr = snmp_stats.outgenerrs;
+    break;
+  case 25: /* snmpOutGetRequests */
+    *uint_ptr = snmp_stats.outgetrequests;
+    break;
+  case 26: /* snmpOutGetNexts */
+    *uint_ptr = snmp_stats.outgetnexts;
+    break;
+  case 27: /* snmpOutSetRequests */
+    *uint_ptr = snmp_stats.outsetrequests;
+    break;
+  case 28: /* snmpOutGetResponses */
+    *uint_ptr = snmp_stats.outgetresponses;
+    break;
+  case 29: /* snmpOutTraps */
+    *uint_ptr = snmp_stats.outtraps;
+    break;
+  case 30: /* snmpEnableAuthenTraps */
+    if (snmp_get_auth_traps_enabled() == SNMP_AUTH_TRAPS_DISABLED) {
+      *uint_ptr = MIB2_AUTH_TRAPS_DISABLED;
+    } else {
+      *uint_ptr = MIB2_AUTH_TRAPS_ENABLED;
+    }
+    break;
+  case 31: /* snmpSilentDrops */
+    *uint_ptr = 0; /* not supported */
+    break;
+  case 32: /* snmpProxyDrops */
+    *uint_ptr = 0; /* not supported */
+    break;
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("snmp_get_value(): unknown id: %"S32_F"\n", node->oid));
+    return 0;
+  }
+
+  return sizeof(*uint_ptr);
+}
+
+static snmp_err_t
+snmp_set_test(const struct snmp_scalar_array_node_def *node, u16_t len, void *value)
+{
+  snmp_err_t ret = SNMP_ERR_WRONGVALUE;
+  LWIP_UNUSED_ARG(len);
+
+  if (node->oid == 30) {
+    /* snmpEnableAuthenTraps */
+    s32_t *sint_ptr = (s32_t*)value;
+
+    /* we should have writable non-volatile mem here */
+    if ((*sint_ptr == MIB2_AUTH_TRAPS_DISABLED) || (*sint_ptr == MIB2_AUTH_TRAPS_ENABLED)) {
+      ret = SNMP_ERR_NOERROR;
+    }
+  }
+  return ret;
+}
+
+static snmp_err_t
+snmp_set_value(const struct snmp_scalar_array_node_def *node, u16_t len, void *value)
+{
+  LWIP_UNUSED_ARG(len);
+
+  if (node->oid == 30) {
+    /* snmpEnableAuthenTraps */
+    s32_t *sint_ptr = (s32_t*)value;
+    if (*sint_ptr == MIB2_AUTH_TRAPS_DISABLED) {
+      snmp_set_auth_traps_enabled(SNMP_AUTH_TRAPS_DISABLED);
+    } else {
+      snmp_set_auth_traps_enabled(SNMP_AUTH_TRAPS_ENABLED);
+    }
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+/* the following nodes access variables in SNMP stack (snmp_stats) from SNMP worker thread -> OK, no sync needed */ 
+static const struct snmp_scalar_array_node_def snmp_nodes[] = {
+  { 1, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInPkts */
+  { 2, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutPkts */
+  { 3, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInBadVersions */
+  { 4, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInBadCommunityNames */
+  { 5, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInBadCommunityUses */
+  { 6, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInASNParseErrs */
+  { 8, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInTooBigs */
+  { 9, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInNoSuchNames */
+  {10, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInBadValues */
+  {11, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInReadOnlys */
+  {12, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInGenErrs */
+  {13, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInTotalReqVars */
+  {14, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInTotalSetVars */
+  {15, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInGetRequests */
+  {16, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInGetNexts */
+  {17, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInSetRequests */
+  {18, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInGetResponses */
+  {19, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpInTraps */
+  {20, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutTooBigs */
+  {21, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutNoSuchNames */
+  {22, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutBadValues */
+  {24, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutGenErrs */
+  {25, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutGetRequests */
+  {26, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutGetNexts */
+  {27, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutSetRequests */
+  {28, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutGetResponses */
+  {29, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpOutTraps */
+  {30, SNMP_ASN1_TYPE_INTEGER, SNMP_NODE_INSTANCE_READ_WRITE}, /* snmpEnableAuthenTraps */
+  {31, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY},  /* snmpSilentDrops */
+  {32, SNMP_ASN1_TYPE_COUNTER, SNMP_NODE_INSTANCE_READ_ONLY}   /* snmpProxyDrops */
+};
+
+const struct snmp_scalar_array_node snmp_mib2_snmp_root = SNMP_SCALAR_CREATE_ARRAY_NODE(11, snmp_nodes, snmp_get_value, snmp_set_test, snmp_set_value);
+
+#endif /* LWIP_SNMP && SNMP_LWIP_MIB2 */

ext/lwip/src/apps/snmp/snmp_mib2_system.c

@@ -0,0 +1,377 @@
+/**
+ * @file
+ * Management Information Base II (RFC1213) SYSTEM objects and functions.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ */
+
+#include "lwip/snmp.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_mib2.h"
+#include "lwip/apps/snmp_table.h"
+#include "lwip/apps/snmp_scalar.h"
+#include "lwip/sys.h"
+
+#include <string.h>
+
+#if LWIP_SNMP && SNMP_LWIP_MIB2
+
+#if SNMP_USE_NETCONN
+#define SYNC_NODE_NAME(node_name) node_name ## _synced
+#define CREATE_LWIP_SYNC_NODE(oid, node_name) \
+   static const struct snmp_threadsync_node node_name ## _synced = SNMP_CREATE_THREAD_SYNC_NODE(oid, &node_name.node, &snmp_mib2_lwip_locks);
+#else
+#define SYNC_NODE_NAME(node_name) node_name
+#define CREATE_LWIP_SYNC_NODE(oid, node_name)
+#endif
+
+/* --- system .1.3.6.1.2.1.1 ----------------------------------------------------- */
+
+/** mib-2.system.sysDescr */
+static const u8_t   sysdescr_default[] = SNMP_LWIP_MIB2_SYSDESC;
+static const u8_t*  sysdescr           = sysdescr_default;
+static const u16_t* sysdescr_len       = NULL; /* use strlen for determining len */
+
+/** mib-2.system.sysContact */
+static const u8_t   syscontact_default[]     = SNMP_LWIP_MIB2_SYSCONTACT;
+static const u8_t*  syscontact               = syscontact_default;
+static const u16_t* syscontact_len           = NULL; /* use strlen for determining len */
+static u8_t*        syscontact_wr            = NULL; /* if writable, points to the same buffer as syscontact (required for correct constness) */
+static u16_t*       syscontact_wr_len        = NULL; /* if writable, points to the same buffer as syscontact_len (required for correct constness) */
+static u16_t        syscontact_bufsize       = 0;    /* 0=not writable */
+
+/** mib-2.system.sysName */
+static const u8_t   sysname_default[]        = SNMP_LWIP_MIB2_SYSNAME;
+static const u8_t*  sysname                  = sysname_default;
+static const u16_t* sysname_len              = NULL; /* use strlen for determining len */
+static u8_t*        sysname_wr               = NULL; /* if writable, points to the same buffer as sysname (required for correct constness) */
+static u16_t*       sysname_wr_len           = NULL; /* if writable, points to the same buffer as sysname_len (required for correct constness) */
+static u16_t        sysname_bufsize          = 0;    /* 0=not writable */
+
+/** mib-2.system.sysLocation */
+static const u8_t   syslocation_default[]    = SNMP_LWIP_MIB2_SYSLOCATION;
+static const u8_t*  syslocation              = syslocation_default;
+static const u16_t* syslocation_len           = NULL; /* use strlen for determining len */
+static u8_t*        syslocation_wr            = NULL; /* if writable, points to the same buffer as syslocation (required for correct constness) */
+static u16_t*       syslocation_wr_len        = NULL; /* if writable, points to the same buffer as syslocation_len (required for correct constness) */
+static u16_t        syslocation_bufsize       = 0;    /* 0=not writable */
+
+/**
+ * @ingroup snmp_mib2
+ * Initializes sysDescr pointers.
+ *
+ * @param str if non-NULL then copy str pointer
+ * @param len points to string length, excluding zero terminator
+ */
+void
+snmp_mib2_set_sysdescr(const u8_t *str, const u16_t *len)
+{
+  if (str != NULL) {
+    sysdescr     = str;
+    sysdescr_len = len;
+  }
+}
+
+/**
+ * @ingroup snmp_mib2
+ * Initializes sysContact pointers
+ *
+ * @param ocstr if non-NULL then copy str pointer
+ * @param ocstrlen points to string length, excluding zero terminator. 
+ *        if set to NULL it is assumed that ocstr is NULL-terminated.
+ * @param bufsize size of the buffer in bytes.
+ *        (this is required because the buffer can be overwritten by snmp-set)
+ *        if ocstrlen is NULL buffer needs space for terminating 0 byte.
+ *        otherwise complete buffer is used for string.
+ *        if bufsize is set to 0, the value is regarded as read-only.
+ */
+void
+snmp_mib2_set_syscontact(u8_t *ocstr, u16_t *ocstrlen, u16_t bufsize)
+{
+  if (ocstr != NULL) {
+    syscontact         = ocstr;
+    syscontact_wr      = ocstr;
+    syscontact_len     = ocstrlen;
+    syscontact_wr_len  = ocstrlen;
+    syscontact_bufsize = bufsize;
+  }
+}
+
+/**
+ * @ingroup snmp_mib2
+ * see \ref snmp_mib2_set_syscontact but set pointer to readonly memory
+ */
+void
+snmp_mib2_set_syscontact_readonly(const u8_t *ocstr, const u16_t *ocstrlen)
+{
+  if (ocstr != NULL) {
+    syscontact         = ocstr;
+    syscontact_len     = ocstrlen;
+    syscontact_wr      = NULL;
+    syscontact_wr_len  = NULL;
+    syscontact_bufsize = 0;
+  }
+}
+
+
+/**
+ * @ingroup snmp_mib2
+ * Initializes sysName pointers
+ *
+ * @param ocstr if non-NULL then copy str pointer
+ * @param ocstrlen points to string length, excluding zero terminator. 
+ *        if set to NULL it is assumed that ocstr is NULL-terminated.
+ * @param bufsize size of the buffer in bytes.
+ *        (this is required because the buffer can be overwritten by snmp-set)
+ *        if ocstrlen is NULL buffer needs space for terminating 0 byte.
+ *        otherwise complete buffer is used for string.
+ *        if bufsize is set to 0, the value is regarded as read-only.
+ */
+void
+snmp_mib2_set_sysname(u8_t *ocstr, u16_t *ocstrlen, u16_t bufsize)
+{
+  if (ocstr != NULL) {
+    sysname         = ocstr;
+    sysname_wr      = ocstr;
+    sysname_len     = ocstrlen;
+    sysname_wr_len  = ocstrlen;
+    sysname_bufsize = bufsize;
+  }
+}
+
+/**
+ * @ingroup snmp_mib2
+ * see \ref snmp_mib2_set_sysname but set pointer to readonly memory
+ */
+void
+snmp_mib2_set_sysname_readonly(const u8_t *ocstr, const u16_t *ocstrlen)
+{
+  if (ocstr != NULL) {
+    sysname         = ocstr;
+    sysname_len     = ocstrlen;
+    sysname_wr      = NULL;
+    sysname_wr_len  = NULL;
+    sysname_bufsize = 0;
+  }
+}
+
+/**
+ * @ingroup snmp_mib2
+ * Initializes sysLocation pointers
+ *
+ * @param ocstr if non-NULL then copy str pointer
+ * @param ocstrlen points to string length, excluding zero terminator. 
+ *        if set to NULL it is assumed that ocstr is NULL-terminated.
+ * @param bufsize size of the buffer in bytes.
+ *        (this is required because the buffer can be overwritten by snmp-set)
+ *        if ocstrlen is NULL buffer needs space for terminating 0 byte.
+ *        otherwise complete buffer is used for string.
+ *        if bufsize is set to 0, the value is regarded as read-only.
+ */
+void
+snmp_mib2_set_syslocation(u8_t *ocstr, u16_t *ocstrlen, u16_t bufsize)
+{
+  if (ocstr != NULL) {
+    syslocation         = ocstr;
+    syslocation_wr      = ocstr;
+    syslocation_len     = ocstrlen;
+    syslocation_wr_len  = ocstrlen;
+    syslocation_bufsize = bufsize;
+  }
+}
+
+/**
+ * @ingroup snmp_mib2
+ * see \ref snmp_mib2_set_syslocation but set pointer to readonly memory
+ */
+void
+snmp_mib2_set_syslocation_readonly(const u8_t *ocstr, const u16_t *ocstrlen)
+{
+  if (ocstr != NULL) {
+    syslocation         = ocstr;
+    syslocation_len     = ocstrlen;
+    syslocation_wr      = NULL;
+    syslocation_wr_len  = NULL;
+    syslocation_bufsize = 0;
+  }
+}
+
+
+static s16_t
+system_get_value(const struct snmp_scalar_array_node_def *node, void *value)
+{
+  const u8_t*  var = NULL;
+  const s16_t* var_len;
+  u16_t result;
+
+  switch (node->oid) {
+  case 1: /* sysDescr */
+    var     = sysdescr;
+    var_len = (const s16_t*)sysdescr_len;
+    break;
+  case 2: /* sysObjectID */
+    {
+      const struct snmp_obj_id* dev_enterprise_oid = snmp_get_device_enterprise_oid();
+      MEMCPY(value, dev_enterprise_oid->id, dev_enterprise_oid->len * sizeof(u32_t));
+      return dev_enterprise_oid->len * sizeof(u32_t);
+    }
+  case 3: /* sysUpTime */
+    MIB2_COPY_SYSUPTIME_TO((u32_t*)value);
+    return sizeof(u32_t);
+  case 4: /* sysContact */
+    var     = syscontact;
+    var_len = (const s16_t*)syscontact_len;
+    break;
+  case 5: /* sysName */
+    var     = sysname;
+    var_len = (const s16_t*)sysname_len;
+    break;
+  case 6: /* sysLocation */
+    var     = syslocation;
+    var_len = (const s16_t*)syslocation_len;
+    break;
+  case 7: /* sysServices */
+    *(s32_t*)value = SNMP_SYSSERVICES;
+    return sizeof(s32_t);
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("system_get_value(): unknown id: %"S32_F"\n", node->oid));
+    return 0;
+  }
+
+  /* handle string values (OID 1,4,5 and 6) */
+  LWIP_ASSERT("", (value != NULL));
+  if (var_len == NULL) {
+    result = (s16_t)strlen((const char*)var);
+  } else {
+    result = *var_len;
+  }
+  MEMCPY(value, var, result);
+  return result;
+}
+
+static snmp_err_t 
+system_set_test(const struct snmp_scalar_array_node_def *node, u16_t len, void *value)
+{
+  snmp_err_t ret = SNMP_ERR_WRONGVALUE;
+  const u16_t* var_bufsize  = NULL;
+  const u16_t* var_wr_len;
+
+  LWIP_UNUSED_ARG(value);
+
+  switch (node->oid) {
+  case 4: /* sysContact */
+    var_bufsize  = &syscontact_bufsize;
+    var_wr_len   = syscontact_wr_len;
+    break;
+  case 5: /* sysName */
+    var_bufsize  = &sysname_bufsize;
+    var_wr_len   = sysname_wr_len;
+    break;
+  case 6: /* sysLocation */
+    var_bufsize  = &syslocation_bufsize;
+    var_wr_len   = syslocation_wr_len;
+    break;
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("system_set_test(): unknown id: %"S32_F"\n", node->oid));
+    return ret;
+  }
+
+  /* check if value is writable at all */
+  if (*var_bufsize > 0) {
+    if (var_wr_len == NULL) {
+      /* we have to take the terminating 0 into account */
+      if (len < *var_bufsize) {
+        ret = SNMP_ERR_NOERROR;
+      }
+    } else {
+      if (len <= *var_bufsize) {
+        ret = SNMP_ERR_NOERROR;
+      }
+    }
+  } else {
+    ret = SNMP_ERR_NOTWRITABLE;
+  }
+
+  return ret;
+}
+
+static snmp_err_t 
+system_set_value(const struct snmp_scalar_array_node_def *node, u16_t len, void *value)
+{
+  u8_t*  var_wr = NULL;
+  u16_t* var_wr_len;
+
+  switch (node->oid) {
+  case 4: /* sysContact */
+    var_wr     = syscontact_wr;
+    var_wr_len = syscontact_wr_len;
+    break;
+  case 5: /* sysName */
+    var_wr     = sysname_wr;
+    var_wr_len = sysname_wr_len;
+    break;
+  case 6: /* sysLocation */
+    var_wr     = syslocation_wr;
+    var_wr_len = syslocation_wr_len;
+    break;
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("system_set_value(): unknown id: %"S32_F"\n", node->oid));
+    return SNMP_ERR_GENERROR;
+  }
+
+  /* no need to check size of target buffer, this was already done in set_test method */
+  LWIP_ASSERT("", var_wr != NULL);
+  MEMCPY(var_wr, value, len);
+  
+  if (var_wr_len == NULL) {
+    /* add terminating 0 */
+    var_wr[len] = 0;
+  } else {
+    *var_wr_len = len;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static const struct snmp_scalar_array_node_def system_nodes[] = {
+  {1, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_ONLY},  /* sysDescr */
+  {2, SNMP_ASN1_TYPE_OBJECT_ID,    SNMP_NODE_INSTANCE_READ_ONLY},  /* sysObjectID */
+  {3, SNMP_ASN1_TYPE_TIMETICKS,    SNMP_NODE_INSTANCE_READ_ONLY},  /* sysUpTime */
+  {4, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_WRITE}, /* sysContact */
+  {5, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_WRITE}, /* sysName */
+  {6, SNMP_ASN1_TYPE_OCTET_STRING, SNMP_NODE_INSTANCE_READ_WRITE}, /* sysLocation */
+  {7, SNMP_ASN1_TYPE_INTEGER,      SNMP_NODE_INSTANCE_READ_ONLY}   /* sysServices */
+};
+
+const struct snmp_scalar_array_node snmp_mib2_system_node = SNMP_SCALAR_CREATE_ARRAY_NODE(1, system_nodes, system_get_value, system_set_test, system_set_value);
+
+#endif /* LWIP_SNMP && SNMP_LWIP_MIB2 */

ext/lwip/src/apps/snmp/snmp_mib2_tcp.c

@@ -0,0 +1,594 @@
+/**
+ * @file
+ * Management Information Base II (RFC1213) TCP objects and functions.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ */
+
+#include "lwip/snmp.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_mib2.h"
+#include "lwip/apps/snmp_table.h"
+#include "lwip/apps/snmp_scalar.h"
+#include "lwip/tcp.h"
+#include "lwip/priv/tcp_priv.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+#if LWIP_SNMP && SNMP_LWIP_MIB2 && LWIP_TCP
+
+#if SNMP_USE_NETCONN
+#define SYNC_NODE_NAME(node_name) node_name ## _synced
+#define CREATE_LWIP_SYNC_NODE(oid, node_name) \
+   static const struct snmp_threadsync_node node_name ## _synced = SNMP_CREATE_THREAD_SYNC_NODE(oid, &node_name.node, &snmp_mib2_lwip_locks);
+#else
+#define SYNC_NODE_NAME(node_name) node_name
+#define CREATE_LWIP_SYNC_NODE(oid, node_name)
+#endif
+
+/* --- tcp .1.3.6.1.2.1.6 ----------------------------------------------------- */
+
+static s16_t 
+tcp_get_value(struct snmp_node_instance* instance, void* value)
+{
+  u32_t *uint_ptr = (u32_t*)value;
+  s32_t *sint_ptr = (s32_t*)value;
+
+  switch (instance->node->oid) {
+  case 1: /* tcpRtoAlgorithm, vanj(4) */
+    *sint_ptr = 4;
+    return sizeof(*sint_ptr);
+  case 2: /* tcpRtoMin */
+    /* @todo not the actual value, a guess,
+        needs to be calculated */
+    *sint_ptr = 1000;
+    return sizeof(*sint_ptr);
+  case 3: /* tcpRtoMax */
+    /* @todo not the actual value, a guess,
+        needs to be calculated */
+    *sint_ptr = 60000;
+    return sizeof(*sint_ptr);
+  case 4: /* tcpMaxConn */
+    *sint_ptr = MEMP_NUM_TCP_PCB;
+    return sizeof(*sint_ptr);
+  case 5: /* tcpActiveOpens */
+    *uint_ptr = STATS_GET(mib2.tcpactiveopens);
+    return sizeof(*uint_ptr);
+  case 6: /* tcpPassiveOpens */
+    *uint_ptr = STATS_GET(mib2.tcppassiveopens);
+    return sizeof(*uint_ptr);
+  case 7: /* tcpAttemptFails */
+    *uint_ptr = STATS_GET(mib2.tcpattemptfails);
+    return sizeof(*uint_ptr);
+  case 8: /* tcpEstabResets */
+    *uint_ptr = STATS_GET(mib2.tcpestabresets);
+    return sizeof(*uint_ptr);
+  case 9: /* tcpCurrEstab */
+    {
+      u16_t tcpcurrestab = 0;
+      struct tcp_pcb *pcb = tcp_active_pcbs;
+      while (pcb != NULL) {
+        if ((pcb->state == ESTABLISHED) ||
+            (pcb->state == CLOSE_WAIT)) {
+          tcpcurrestab++;
+        }
+        pcb = pcb->next;
+      }
+      *uint_ptr = tcpcurrestab;
+    }
+    return sizeof(*uint_ptr);
+  case 10: /* tcpInSegs */
+    *uint_ptr = STATS_GET(mib2.tcpinsegs);
+    return sizeof(*uint_ptr);
+  case 11: /* tcpOutSegs */
+    *uint_ptr = STATS_GET(mib2.tcpoutsegs);
+    return sizeof(*uint_ptr);
+  case 12: /* tcpRetransSegs */
+    *uint_ptr = STATS_GET(mib2.tcpretranssegs);
+    return sizeof(*uint_ptr);
+  case 14: /* tcpInErrs */
+    *uint_ptr = STATS_GET(mib2.tcpinerrs);
+    return sizeof(*uint_ptr);
+  case 15: /* tcpOutRsts */
+    *uint_ptr = STATS_GET(mib2.tcpoutrsts);
+    return sizeof(*uint_ptr);
+  case 17: /* tcpHCInSegs */
+    memset(value, 0, 2*sizeof(u32_t)); /* not supported */
+    return 2*sizeof(u32_t);
+  case 18: /* tcpHCOutSegs */
+    memset(value, 0, 2*sizeof(u32_t)); /* not supported */
+    return 2*sizeof(u32_t);
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("tcp_get_value(): unknown id: %"S32_F"\n", instance->node->oid));
+    break;
+  }
+
+  return 0;
+}
+
+/* --- tcpConnTable --- */
+
+#if LWIP_IPV4
+
+/* list of allowed value ranges for incoming OID */
+static const struct snmp_oid_range tcp_ConnTable_oid_ranges[] = {
+  { 0, 0xff   }, /* IP A */
+  { 0, 0xff   }, /* IP B */
+  { 0, 0xff   }, /* IP C */
+  { 0, 0xff   }, /* IP D */
+  { 0, 0xffff }, /* Port */
+  { 0, 0xff   }, /* IP A */
+  { 0, 0xff   }, /* IP B */
+  { 0, 0xff   }, /* IP C */
+  { 0, 0xff   }, /* IP D */
+  { 0, 0xffff }  /* Port */
+};
+
+static snmp_err_t 
+tcp_ConnTable_get_cell_value_core(struct tcp_pcb *pcb, const u32_t* column, union snmp_variant_value* value, u32_t* value_len)
+{
+  LWIP_UNUSED_ARG(value_len);
+
+  /* value */
+  switch (*column) {
+  case 1: /* tcpConnState */
+    value->u32 = pcb->state + 1;
+    break;
+  case 2: /* tcpConnLocalAddress */
+    value->u32 = ip_2_ip4(&pcb->local_ip)->addr;
+    break;
+  case 3: /* tcpConnLocalPort */
+    value->u32 = pcb->local_port;
+    break;
+  case 4: /* tcpConnRemAddress */
+    if (pcb->state == LISTEN) {
+      value->u32 = IP4_ADDR_ANY->addr;
+    } else {
+      value->u32 = ip_2_ip4(&pcb->remote_ip)->addr;
+    }
+    break;
+  case 5: /* tcpConnRemPort */
+    if (pcb->state == LISTEN) {
+      value->u32 = 0;
+    } else {
+      value->u32 = pcb->remote_port;
+    }
+    break;
+  default:
+    LWIP_ASSERT("invalid id", 0);
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static snmp_err_t
+tcp_ConnTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, union snmp_variant_value* value, u32_t* value_len)
+{
+  u8_t i;
+  ip4_addr_t local_ip;
+  ip4_addr_t remote_ip;
+  u16_t local_port;
+  u16_t remote_port;
+  struct tcp_pcb *pcb;
+
+  /* check if incoming OID length and if values are in plausible range */
+  if (!snmp_oid_in_range(row_oid, row_oid_len, tcp_ConnTable_oid_ranges, LWIP_ARRAYSIZE(tcp_ConnTable_oid_ranges))) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* get IPs and ports from incoming OID */
+  snmp_oid_to_ip4(&row_oid[0], &local_ip); /* we know it succeeds because of oid_in_range check above */
+  local_port = (u16_t)row_oid[4];
+  snmp_oid_to_ip4(&row_oid[5], &remote_ip); /* we know it succeeds because of oid_in_range check above */
+  remote_port = (u16_t)row_oid[9];
+  
+  /* find tcp_pcb with requested ips and ports */
+  for (i = 0; i < LWIP_ARRAYSIZE(tcp_pcb_lists); i++) {
+    pcb = *tcp_pcb_lists[i];
+
+    while (pcb != NULL) {
+      /* do local IP and local port match? */
+      if (IP_IS_V4_VAL(pcb->local_ip) &&
+         ip4_addr_cmp(&local_ip, ip_2_ip4(&pcb->local_ip)) && (local_port == pcb->local_port)) {
+
+        /* PCBs in state LISTEN are not connected and have no remote_ip or remote_port */
+        if (pcb->state == LISTEN) {
+          if (ip4_addr_cmp(&remote_ip, IP4_ADDR_ANY) && (remote_port == 0)) {
+            /* fill in object properties */
+            return tcp_ConnTable_get_cell_value_core(pcb, column, value, value_len);
+          }
+        } else {
+          if (IP_IS_V4_VAL(pcb->remote_ip) &&
+             ip4_addr_cmp(&remote_ip, ip_2_ip4(&pcb->remote_ip)) && (remote_port == pcb->remote_port)) {
+            /* fill in object properties */
+            return tcp_ConnTable_get_cell_value_core(pcb, column, value, value_len);
+          }
+        }
+      }
+
+      pcb = pcb->next;
+    }
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+static snmp_err_t
+tcp_ConnTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_obj_id* row_oid, union snmp_variant_value* value, u32_t* value_len)
+{
+  u8_t i;
+  struct tcp_pcb *pcb;
+  struct snmp_next_oid_state state;
+  u32_t result_temp[LWIP_ARRAYSIZE(tcp_ConnTable_oid_ranges)];
+
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(tcp_ConnTable_oid_ranges));
+
+  /* iterate over all possible OIDs to find the next one */
+  for (i = 0; i < LWIP_ARRAYSIZE(tcp_pcb_lists); i++) {
+    pcb = *tcp_pcb_lists[i];
+    while (pcb != NULL) {
+      u32_t test_oid[LWIP_ARRAYSIZE(tcp_ConnTable_oid_ranges)];
+            
+      if (IP_IS_V4_VAL(pcb->local_ip)) {
+        snmp_ip4_to_oid(ip_2_ip4(&pcb->local_ip), &test_oid[0]);
+        test_oid[4] = pcb->local_port;
+
+        /* PCBs in state LISTEN are not connected and have no remote_ip or remote_port */
+        if (pcb->state == LISTEN) {
+          snmp_ip4_to_oid(IP4_ADDR_ANY, &test_oid[5]);
+          test_oid[9] = 0;
+        } else {
+          if (IP_IS_V6_VAL(pcb->remote_ip)) { /* should never happen */
+            continue;
+          }
+          snmp_ip4_to_oid(ip_2_ip4(&pcb->remote_ip), &test_oid[5]);
+          test_oid[9] = pcb->remote_port;
+        }
+
+        /* check generated OID: is it a candidate for the next one? */
+        snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(tcp_ConnTable_oid_ranges), pcb);
+      }
+    
+      pcb = pcb->next;
+    }
+  }
+
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* fill in object properties */
+    return tcp_ConnTable_get_cell_value_core((struct tcp_pcb*)state.reference, column, value, value_len);
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+#endif /* LWIP_IPV4 */
+
+/* --- tcpConnectionTable --- */
+
+static snmp_err_t 
+tcp_ConnectionTable_get_cell_value_core(const u32_t* column, struct tcp_pcb *pcb, union snmp_variant_value* value)
+{
+  /* all items except tcpConnectionState and tcpConnectionProcess are declared as not-accessible */   
+  switch (*column) {
+  case 7: /* tcpConnectionState */
+    value->u32 = pcb->state + 1;
+    break;
+  case 8: /* tcpConnectionProcess */
+    value->u32 = 0; /* not supported */
+    break;
+  default:
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static snmp_err_t
+tcp_ConnectionTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, union snmp_variant_value* value, u32_t* value_len)
+{
+  ip_addr_t local_ip, remote_ip;
+  u16_t local_port, remote_port;
+  struct tcp_pcb *pcb;
+  u8_t idx = 0;
+  u8_t i;
+  struct tcp_pcb ** const tcp_pcb_nonlisten_lists[] = {&tcp_bound_pcbs, &tcp_active_pcbs, &tcp_tw_pcbs};
+
+  LWIP_UNUSED_ARG(value_len);
+
+  /* tcpConnectionLocalAddressType + tcpConnectionLocalAddress + tcpConnectionLocalPort */
+  idx += snmp_oid_to_ip_port(&row_oid[idx], row_oid_len-idx, &local_ip, &local_port);
+  if (idx == 0) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+  
+  /* tcpConnectionRemAddressType + tcpConnectionRemAddress + tcpConnectionRemPort */
+  idx += snmp_oid_to_ip_port(&row_oid[idx], row_oid_len-idx, &remote_ip, &remote_port);
+  if (idx == 0) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* find tcp_pcb with requested ip and port*/
+  for (i = 0; i < LWIP_ARRAYSIZE(tcp_pcb_nonlisten_lists); i++) {
+    pcb = *tcp_pcb_nonlisten_lists[i];
+    
+    while (pcb != NULL) {
+      if (ip_addr_cmp(&local_ip, &pcb->local_ip) &&
+         (local_port == pcb->local_port) &&
+         ip_addr_cmp(&remote_ip, &pcb->remote_ip) &&
+         (remote_port == pcb->remote_port)) {
+        /* fill in object properties */
+        return tcp_ConnectionTable_get_cell_value_core(column, pcb, value);
+      }
+      pcb = pcb->next;
+    }
+  }
+  
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;  
+}
+
+static snmp_err_t
+tcp_ConnectionTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_obj_id* row_oid, union snmp_variant_value* value, u32_t* value_len)
+{
+  struct tcp_pcb *pcb;
+  struct snmp_next_oid_state state;
+  /* 1x tcpConnectionLocalAddressType + 1x OID len + 16x tcpConnectionLocalAddress  + 1x tcpConnectionLocalPort
+   * 1x tcpConnectionRemAddressType   + 1x OID len + 16x tcpConnectionRemAddress    + 1x tcpConnectionRemPort */
+  u32_t  result_temp[38];
+  u8_t i;
+  struct tcp_pcb ** const tcp_pcb_nonlisten_lists[] = {&tcp_bound_pcbs, &tcp_active_pcbs, &tcp_tw_pcbs};
+
+  LWIP_UNUSED_ARG(value_len);
+
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(result_temp));
+
+  /* iterate over all possible OIDs to find the next one */
+  for (i = 0; i < LWIP_ARRAYSIZE(tcp_pcb_nonlisten_lists); i++) {
+    pcb = *tcp_pcb_nonlisten_lists[i];
+
+    while (pcb != NULL) {
+      u8_t idx = 0;
+      u32_t test_oid[LWIP_ARRAYSIZE(result_temp)];
+
+      /* tcpConnectionLocalAddressType + tcpConnectionLocalAddress + tcpConnectionLocalPort */
+      idx += snmp_ip_port_to_oid(&pcb->local_ip, pcb->local_port, &test_oid[idx]);
+
+      /* tcpConnectionRemAddressType + tcpConnectionRemAddress + tcpConnectionRemPort */
+      idx += snmp_ip_port_to_oid(&pcb->remote_ip, pcb->remote_port, &test_oid[idx]);
+
+      /* check generated OID: is it a candidate for the next one? */
+      snmp_next_oid_check(&state, test_oid, idx, pcb);
+    
+      pcb = pcb->next;
+    }
+  }
+  
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* fill in object properties */
+    return tcp_ConnectionTable_get_cell_value_core(column, (struct tcp_pcb*)state.reference, value);
+  } else {
+    /* not found */
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+}
+
+/* --- tcpListenerTable --- */
+
+static snmp_err_t 
+tcp_ListenerTable_get_cell_value_core(const u32_t* column, union snmp_variant_value* value)
+{
+  /* all items except tcpListenerProcess are declared as not-accessible */   
+  switch (*column) {
+  case 4: /* tcpListenerProcess */
+    value->u32 = 0; /* not supported */
+    break;
+  default:
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static snmp_err_t
+tcp_ListenerTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, union snmp_variant_value* value, u32_t* value_len)
+{
+  ip_addr_t local_ip;
+  u16_t local_port;
+  struct tcp_pcb_listen *pcb;
+  u8_t idx = 0;
+
+  LWIP_UNUSED_ARG(value_len);
+
+  /* tcpListenerLocalAddressType + tcpListenerLocalAddress + tcpListenerLocalPort */
+  idx += snmp_oid_to_ip_port(&row_oid[idx], row_oid_len-idx, &local_ip, &local_port);
+  if (idx == 0) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+  
+  /* find tcp_pcb with requested ip and port*/
+  pcb = tcp_listen_pcbs.listen_pcbs;
+  while (pcb != NULL) {
+    if (ip_addr_cmp(&local_ip, &pcb->local_ip) &&
+       (local_port == pcb->local_port)) {
+      /* fill in object properties */
+      return tcp_ListenerTable_get_cell_value_core(column, value);
+    }
+    pcb = pcb->next;
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;  
+}
+
+static snmp_err_t
+tcp_ListenerTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_obj_id* row_oid, union snmp_variant_value* value, u32_t* value_len)
+{
+  struct tcp_pcb_listen *pcb;
+  struct snmp_next_oid_state state;
+  /* 1x tcpListenerLocalAddressType + 1x OID len + 16x tcpListenerLocalAddress  + 1x tcpListenerLocalPort */
+  u32_t  result_temp[19];
+
+  LWIP_UNUSED_ARG(value_len);
+
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(result_temp));
+
+  /* iterate over all possible OIDs to find the next one */
+  pcb = tcp_listen_pcbs.listen_pcbs;
+  while (pcb != NULL) {
+    u8_t idx = 0;
+    u32_t test_oid[LWIP_ARRAYSIZE(result_temp)];
+            
+    /* tcpListenerLocalAddressType + tcpListenerLocalAddress + tcpListenerLocalPort */
+    idx += snmp_ip_port_to_oid(&pcb->local_ip, pcb->local_port, &test_oid[idx]);
+
+    /* check generated OID: is it a candidate for the next one? */
+    snmp_next_oid_check(&state, test_oid, idx, NULL);
+    
+    pcb = pcb->next;
+  }
+
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* fill in object properties */
+    return tcp_ListenerTable_get_cell_value_core(column, value);
+  } else {
+    /* not found */
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+}
+
+static const struct snmp_scalar_node tcp_RtoAlgorithm  = SNMP_SCALAR_CREATE_NODE_READONLY(1, SNMP_ASN1_TYPE_INTEGER, tcp_get_value);
+static const struct snmp_scalar_node tcp_RtoMin        = SNMP_SCALAR_CREATE_NODE_READONLY(2, SNMP_ASN1_TYPE_INTEGER, tcp_get_value);
+static const struct snmp_scalar_node tcp_RtoMax        = SNMP_SCALAR_CREATE_NODE_READONLY(3, SNMP_ASN1_TYPE_INTEGER, tcp_get_value);
+static const struct snmp_scalar_node tcp_MaxConn       = SNMP_SCALAR_CREATE_NODE_READONLY(4, SNMP_ASN1_TYPE_INTEGER, tcp_get_value);
+static const struct snmp_scalar_node tcp_ActiveOpens   = SNMP_SCALAR_CREATE_NODE_READONLY(5, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_PassiveOpens  = SNMP_SCALAR_CREATE_NODE_READONLY(6, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_AttemptFails  = SNMP_SCALAR_CREATE_NODE_READONLY(7, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_EstabResets   = SNMP_SCALAR_CREATE_NODE_READONLY(8, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_CurrEstab     = SNMP_SCALAR_CREATE_NODE_READONLY(9, SNMP_ASN1_TYPE_GAUGE, tcp_get_value);
+static const struct snmp_scalar_node tcp_InSegs        = SNMP_SCALAR_CREATE_NODE_READONLY(10, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_OutSegs       = SNMP_SCALAR_CREATE_NODE_READONLY(11, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_RetransSegs   = SNMP_SCALAR_CREATE_NODE_READONLY(12, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_InErrs        = SNMP_SCALAR_CREATE_NODE_READONLY(14, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_OutRsts       = SNMP_SCALAR_CREATE_NODE_READONLY(15, SNMP_ASN1_TYPE_COUNTER, tcp_get_value);
+static const struct snmp_scalar_node tcp_HCInSegs      = SNMP_SCALAR_CREATE_NODE_READONLY(17, SNMP_ASN1_TYPE_COUNTER64, tcp_get_value);
+static const struct snmp_scalar_node tcp_HCOutSegs     = SNMP_SCALAR_CREATE_NODE_READONLY(18, SNMP_ASN1_TYPE_COUNTER64, tcp_get_value);
+
+#if LWIP_IPV4
+static const struct snmp_table_simple_col_def tcp_ConnTable_columns[] = {
+  {  1, SNMP_ASN1_TYPE_INTEGER, SNMP_VARIANT_VALUE_TYPE_U32 }, /* tcpConnState */
+  {  2, SNMP_ASN1_TYPE_IPADDR,  SNMP_VARIANT_VALUE_TYPE_U32 }, /* tcpConnLocalAddress */
+  {  3, SNMP_ASN1_TYPE_INTEGER, SNMP_VARIANT_VALUE_TYPE_U32 }, /* tcpConnLocalPort */
+  {  4, SNMP_ASN1_TYPE_IPADDR,  SNMP_VARIANT_VALUE_TYPE_U32 }, /* tcpConnRemAddress */
+  {  5, SNMP_ASN1_TYPE_INTEGER, SNMP_VARIANT_VALUE_TYPE_U32 }  /* tcpConnRemPort */
+};
+
+static const struct snmp_table_simple_node tcp_ConnTable = SNMP_TABLE_CREATE_SIMPLE(13, tcp_ConnTable_columns, tcp_ConnTable_get_cell_value, tcp_ConnTable_get_next_cell_instance_and_value);
+#endif /* LWIP_IPV4 */
+
+static const struct snmp_table_simple_col_def tcp_ConnectionTable_columns[] = {
+  /* all items except tcpConnectionState and tcpConnectionProcess are declared as not-accessible */   
+  { 7, SNMP_ASN1_TYPE_INTEGER,    SNMP_VARIANT_VALUE_TYPE_U32 }, /* tcpConnectionState */
+  { 8, SNMP_ASN1_TYPE_UNSIGNED32, SNMP_VARIANT_VALUE_TYPE_U32 }  /* tcpConnectionProcess */
+};
+
+static const struct snmp_table_simple_node tcp_ConnectionTable = SNMP_TABLE_CREATE_SIMPLE(19, tcp_ConnectionTable_columns, tcp_ConnectionTable_get_cell_value, tcp_ConnectionTable_get_next_cell_instance_and_value);
+
+
+static const struct snmp_table_simple_col_def tcp_ListenerTable_columns[] = {
+  /* all items except tcpListenerProcess are declared as not-accessible */   
+  { 4, SNMP_ASN1_TYPE_UNSIGNED32, SNMP_VARIANT_VALUE_TYPE_U32 }  /* tcpListenerProcess */
+};
+
+static const struct snmp_table_simple_node tcp_ListenerTable = SNMP_TABLE_CREATE_SIMPLE(20, tcp_ListenerTable_columns, tcp_ListenerTable_get_cell_value, tcp_ListenerTable_get_next_cell_instance_and_value);
+
+/* the following nodes access variables in LWIP stack from SNMP worker thread and must therefore be synced to LWIP (TCPIP) thread */ 
+CREATE_LWIP_SYNC_NODE( 1, tcp_RtoAlgorithm)
+CREATE_LWIP_SYNC_NODE( 2, tcp_RtoMin)
+CREATE_LWIP_SYNC_NODE( 3, tcp_RtoMax)
+CREATE_LWIP_SYNC_NODE( 4, tcp_MaxConn)
+CREATE_LWIP_SYNC_NODE( 5, tcp_ActiveOpens)
+CREATE_LWIP_SYNC_NODE( 6, tcp_PassiveOpens)
+CREATE_LWIP_SYNC_NODE( 7, tcp_AttemptFails)
+CREATE_LWIP_SYNC_NODE( 8, tcp_EstabResets)
+CREATE_LWIP_SYNC_NODE( 9, tcp_CurrEstab)
+CREATE_LWIP_SYNC_NODE(10, tcp_InSegs)
+CREATE_LWIP_SYNC_NODE(11, tcp_OutSegs)
+CREATE_LWIP_SYNC_NODE(12, tcp_RetransSegs)
+#if LWIP_IPV4
+CREATE_LWIP_SYNC_NODE(13, tcp_ConnTable)
+#endif /* LWIP_IPV4 */
+CREATE_LWIP_SYNC_NODE(14, tcp_InErrs)
+CREATE_LWIP_SYNC_NODE(15, tcp_OutRsts)
+CREATE_LWIP_SYNC_NODE(17, tcp_HCInSegs)
+CREATE_LWIP_SYNC_NODE(18, tcp_HCOutSegs)
+CREATE_LWIP_SYNC_NODE(19, tcp_ConnectionTable)
+CREATE_LWIP_SYNC_NODE(20, tcp_ListenerTable)
+
+static const struct snmp_node* const tcp_nodes[] = {
+  &SYNC_NODE_NAME(tcp_RtoAlgorithm).node.node,
+  &SYNC_NODE_NAME(tcp_RtoMin).node.node,
+  &SYNC_NODE_NAME(tcp_RtoMax).node.node,
+  &SYNC_NODE_NAME(tcp_MaxConn).node.node,
+  &SYNC_NODE_NAME(tcp_ActiveOpens).node.node,
+  &SYNC_NODE_NAME(tcp_PassiveOpens).node.node,
+  &SYNC_NODE_NAME(tcp_AttemptFails).node.node,
+  &SYNC_NODE_NAME(tcp_EstabResets).node.node,
+  &SYNC_NODE_NAME(tcp_CurrEstab).node.node,
+  &SYNC_NODE_NAME(tcp_InSegs).node.node,
+  &SYNC_NODE_NAME(tcp_OutSegs).node.node,
+  &SYNC_NODE_NAME(tcp_RetransSegs).node.node,
+#if LWIP_IPV4
+  &SYNC_NODE_NAME(tcp_ConnTable).node.node,
+#endif /* LWIP_IPV4 */
+  &SYNC_NODE_NAME(tcp_InErrs).node.node,
+  &SYNC_NODE_NAME(tcp_OutRsts).node.node,
+  &SYNC_NODE_NAME(tcp_HCInSegs).node.node,
+  &SYNC_NODE_NAME(tcp_HCOutSegs).node.node,
+  &SYNC_NODE_NAME(tcp_ConnectionTable).node.node,
+  &SYNC_NODE_NAME(tcp_ListenerTable).node.node
+};
+
+const struct snmp_tree_node snmp_mib2_tcp_root = SNMP_CREATE_TREE_NODE(6, tcp_nodes);
+#endif /* LWIP_SNMP && SNMP_LWIP_MIB2 && LWIP_TCP */

ext/lwip/src/apps/snmp/snmp_mib2_udp.c

@@ -0,0 +1,357 @@
+/**
+ * @file
+ * Management Information Base II (RFC1213) UDP objects and functions.
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ */
+
+#include "lwip/snmp.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_mib2.h"
+#include "lwip/apps/snmp_table.h"
+#include "lwip/apps/snmp_scalar.h"
+#include "lwip/udp.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+#if LWIP_SNMP && SNMP_LWIP_MIB2 && LWIP_UDP
+
+#if SNMP_USE_NETCONN
+#define SYNC_NODE_NAME(node_name) node_name ## _synced
+#define CREATE_LWIP_SYNC_NODE(oid, node_name) \
+   static const struct snmp_threadsync_node node_name ## _synced = SNMP_CREATE_THREAD_SYNC_NODE(oid, &node_name.node, &snmp_mib2_lwip_locks);
+#else
+#define SYNC_NODE_NAME(node_name) node_name
+#define CREATE_LWIP_SYNC_NODE(oid, node_name)
+#endif
+
+/* --- udp .1.3.6.1.2.1.7 ----------------------------------------------------- */
+
+static s16_t 
+udp_get_value(struct snmp_node_instance* instance, void* value)
+{
+  u32_t *uint_ptr = (u32_t*)value;
+
+  switch (instance->node->oid) {
+  case 1: /* udpInDatagrams */
+    *uint_ptr = STATS_GET(mib2.udpindatagrams);
+    return sizeof(*uint_ptr);
+  case 2: /* udpNoPorts */
+    *uint_ptr = STATS_GET(mib2.udpnoports);
+    return sizeof(*uint_ptr);
+  case 3: /* udpInErrors */
+    *uint_ptr = STATS_GET(mib2.udpinerrors);
+    return sizeof(*uint_ptr);
+  case 4: /* udpOutDatagrams */
+    *uint_ptr = STATS_GET(mib2.udpoutdatagrams);
+    return sizeof(*uint_ptr);
+  case 8: /* udpHCInDatagrams */
+    memset(value, 0, 2*sizeof(u32_t)); /* not supported */
+    return 2*sizeof(u32_t);
+  case 9: /* udpHCOutDatagrams */
+    memset(value, 0, 2*sizeof(u32_t)); /* not supported */
+    return 2*sizeof(u32_t);
+  default:
+    LWIP_DEBUGF(SNMP_MIB_DEBUG,("udp_get_value(): unknown id: %"S32_F"\n", instance->node->oid));
+    break;
+  }
+
+  return 0;
+}
+
+/* --- udpEndpointTable --- */
+
+static snmp_err_t 
+udp_endpointTable_get_cell_value_core(const u32_t* column, union snmp_variant_value* value)
+{
+  /* all items except udpEndpointProcess are declared as not-accessible */   
+  switch (*column) {
+  case 8: /* udpEndpointProcess */
+    value->u32 = 0; /* not supported */
+    break;
+  default:
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static snmp_err_t 
+udp_endpointTable_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, union snmp_variant_value* value, u32_t* value_len)
+{
+  ip_addr_t local_ip, remote_ip;
+  u16_t local_port, remote_port;
+  struct udp_pcb *pcb;
+  u8_t idx = 0;
+
+  LWIP_UNUSED_ARG(value_len);
+
+  /* udpEndpointLocalAddressType + udpEndpointLocalAddress + udpEndpointLocalPort */
+  idx += snmp_oid_to_ip_port(&row_oid[idx], row_oid_len-idx, &local_ip, &local_port);
+  if (idx == 0) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* udpEndpointRemoteAddressType + udpEndpointRemoteAddress + udpEndpointRemotePort */
+  idx += snmp_oid_to_ip_port(&row_oid[idx], row_oid_len-idx, &remote_ip, &remote_port);
+  if (idx == 0) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* udpEndpointInstance */
+  if (row_oid_len < (idx+1)) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+  if (row_oid[idx] != 0) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+  
+  /* find udp_pcb with requested ip and port*/
+  pcb = udp_pcbs;
+  while (pcb != NULL) {
+    if (ip_addr_cmp(&local_ip, &pcb->local_ip) &&
+       (local_port == pcb->local_port) &&
+       ip_addr_cmp(&remote_ip, &pcb->remote_ip) &&
+       (remote_port == pcb->remote_port)) {
+      /* fill in object properties */
+      return udp_endpointTable_get_cell_value_core(column, value);
+    }
+    pcb = pcb->next;
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+static snmp_err_t 
+udp_endpointTable_get_next_cell_instance_and_value(const u32_t* column, struct snmp_obj_id* row_oid, union snmp_variant_value* value, u32_t* value_len)
+{
+  struct udp_pcb *pcb;
+  struct snmp_next_oid_state state;
+  /* 1x udpEndpointLocalAddressType  + 1x OID len + 16x udpEndpointLocalAddress  + 1x udpEndpointLocalPort  +
+   * 1x udpEndpointRemoteAddressType + 1x OID len + 16x udpEndpointRemoteAddress + 1x udpEndpointRemotePort +
+   * 1x udpEndpointInstance = 39
+   */
+  u32_t  result_temp[39];
+
+  LWIP_UNUSED_ARG(value_len);
+
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(result_temp));
+
+  /* iterate over all possible OIDs to find the next one */
+  pcb = udp_pcbs;
+  while (pcb != NULL) {
+    u32_t test_oid[LWIP_ARRAYSIZE(result_temp)];
+    u8_t idx = 0;
+
+    /* udpEndpointLocalAddressType + udpEndpointLocalAddress + udpEndpointLocalPort */
+    idx += snmp_ip_port_to_oid(&pcb->local_ip, pcb->local_port, &test_oid[idx]);
+
+    /* udpEndpointRemoteAddressType + udpEndpointRemoteAddress + udpEndpointRemotePort */
+    idx += snmp_ip_port_to_oid(&pcb->remote_ip, pcb->remote_port, &test_oid[idx]);
+
+    test_oid[idx] = 0; /* udpEndpointInstance */    
+    idx++;
+    
+    /* check generated OID: is it a candidate for the next one? */
+    snmp_next_oid_check(&state, test_oid, idx, NULL);
+    
+    pcb = pcb->next;
+  }
+
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* fill in object properties */
+    return udp_endpointTable_get_cell_value_core(column, value);
+  } else {
+    /* not found */
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+}
+
+/* --- udpTable --- */
+
+#if LWIP_IPV4
+
+/* list of allowed value ranges for incoming OID */
+static const struct snmp_oid_range udp_Table_oid_ranges[] = {
+  { 0, 0xff   }, /* IP A        */
+  { 0, 0xff   }, /* IP B        */
+  { 0, 0xff   }, /* IP C        */
+  { 0, 0xff   }, /* IP D        */
+  { 1, 0xffff }  /* Port        */
+};
+
+static snmp_err_t 
+udp_Table_get_cell_value_core(struct udp_pcb *pcb, const u32_t* column, union snmp_variant_value* value, u32_t* value_len)
+{
+  LWIP_UNUSED_ARG(value_len);
+
+  switch (*column) {
+  case 1: /* udpLocalAddress */
+    /* set reference to PCB local IP and return a generic node that copies IP4 addresses */
+    value->u32 = ip_2_ip4(&pcb->local_ip)->addr;
+    break;
+  case 2: /* udpLocalPort */
+    /* set reference to PCB local port and return a generic node that copies u16_t values */
+    value->u32 = pcb->local_port;
+    break;
+  default:
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  return SNMP_ERR_NOERROR;
+}
+
+static snmp_err_t 
+udp_Table_get_cell_value(const u32_t* column, const u32_t* row_oid, u8_t row_oid_len, union snmp_variant_value* value, u32_t* value_len)
+{
+  ip4_addr_t ip;
+  u16_t port;
+  struct udp_pcb *pcb;
+
+  /* check if incoming OID length and if values are in plausible range */
+  if (!snmp_oid_in_range(row_oid, row_oid_len, udp_Table_oid_ranges, LWIP_ARRAYSIZE(udp_Table_oid_ranges))) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  /* get IP and port from incoming OID */
+  snmp_oid_to_ip4(&row_oid[0], &ip); /* we know it succeeds because of oid_in_range check above */
+  port = (u16_t)row_oid[4];
+
+  /* find udp_pcb with requested ip and port*/
+  pcb = udp_pcbs;
+  while (pcb != NULL) {
+    if (IP_IS_V4_VAL(pcb->local_ip)) {
+      if (ip4_addr_cmp(&ip, ip_2_ip4(&pcb->local_ip)) && (port == pcb->local_port)) {
+        /* fill in object properties */
+        return udp_Table_get_cell_value_core(pcb, column, value, value_len);
+      }
+    }
+    pcb = pcb->next;
+  }
+
+  /* not found */
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+static snmp_err_t 
+udp_Table_get_next_cell_instance_and_value(const u32_t* column, struct snmp_obj_id* row_oid, union snmp_variant_value* value, u32_t* value_len)
+{
+  struct udp_pcb *pcb;
+  struct snmp_next_oid_state state;
+  u32_t  result_temp[LWIP_ARRAYSIZE(udp_Table_oid_ranges)];
+
+  /* init struct to search next oid */
+  snmp_next_oid_init(&state, row_oid->id, row_oid->len, result_temp, LWIP_ARRAYSIZE(udp_Table_oid_ranges));
+
+  /* iterate over all possible OIDs to find the next one */
+  pcb = udp_pcbs;
+  while (pcb != NULL) {
+    u32_t test_oid[LWIP_ARRAYSIZE(udp_Table_oid_ranges)];
+
+    if (IP_IS_V4_VAL(pcb->local_ip)) {
+      snmp_ip4_to_oid(ip_2_ip4(&pcb->local_ip), &test_oid[0]);
+      test_oid[4] = pcb->local_port;
+
+      /* check generated OID: is it a candidate for the next one? */
+      snmp_next_oid_check(&state, test_oid, LWIP_ARRAYSIZE(udp_Table_oid_ranges), pcb);
+    }
+    
+    pcb = pcb->next;
+  }
+
+  /* did we find a next one? */
+  if (state.status == SNMP_NEXT_OID_STATUS_SUCCESS) {
+    snmp_oid_assign(row_oid, state.next_oid, state.next_oid_len);
+    /* fill in object properties */
+    return udp_Table_get_cell_value_core((struct udp_pcb*)state.reference, column, value, value_len);
+  } else {
+    /* not found */
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+}
+
+#endif /* LWIP_IPV4 */
+
+static const struct snmp_scalar_node udp_inDatagrams    = SNMP_SCALAR_CREATE_NODE_READONLY(1, SNMP_ASN1_TYPE_COUNTER,   udp_get_value);
+static const struct snmp_scalar_node udp_noPorts        = SNMP_SCALAR_CREATE_NODE_READONLY(2, SNMP_ASN1_TYPE_COUNTER,   udp_get_value);
+static const struct snmp_scalar_node udp_inErrors       = SNMP_SCALAR_CREATE_NODE_READONLY(3, SNMP_ASN1_TYPE_COUNTER,   udp_get_value);
+static const struct snmp_scalar_node udp_outDatagrams   = SNMP_SCALAR_CREATE_NODE_READONLY(4, SNMP_ASN1_TYPE_COUNTER,   udp_get_value);
+static const struct snmp_scalar_node udp_HCInDatagrams  = SNMP_SCALAR_CREATE_NODE_READONLY(8, SNMP_ASN1_TYPE_COUNTER64, udp_get_value);
+static const struct snmp_scalar_node udp_HCOutDatagrams = SNMP_SCALAR_CREATE_NODE_READONLY(9, SNMP_ASN1_TYPE_COUNTER64, udp_get_value);
+
+#if LWIP_IPV4
+static const struct snmp_table_simple_col_def udp_Table_columns[] = {
+  { 1, SNMP_ASN1_TYPE_IPADDR,  SNMP_VARIANT_VALUE_TYPE_U32 }, /* udpLocalAddress */
+  { 2, SNMP_ASN1_TYPE_INTEGER, SNMP_VARIANT_VALUE_TYPE_U32 }  /* udpLocalPort */
+};
+static const struct snmp_table_simple_node udp_Table = SNMP_TABLE_CREATE_SIMPLE(5, udp_Table_columns, udp_Table_get_cell_value, udp_Table_get_next_cell_instance_and_value);
+#endif /* LWIP_IPV4 */
+
+static const struct snmp_table_simple_col_def udp_endpointTable_columns[] = {
+  /* all items except udpEndpointProcess are declared as not-accessible */   
+  { 8, SNMP_ASN1_TYPE_UNSIGNED32, SNMP_VARIANT_VALUE_TYPE_U32 }  /* udpEndpointProcess */
+};
+
+static const struct snmp_table_simple_node udp_endpointTable = SNMP_TABLE_CREATE_SIMPLE(7, udp_endpointTable_columns, udp_endpointTable_get_cell_value, udp_endpointTable_get_next_cell_instance_and_value);
+
+/* the following nodes access variables in LWIP stack from SNMP worker thread and must therefore be synced to LWIP (TCPIP) thread */ 
+CREATE_LWIP_SYNC_NODE(1, udp_inDatagrams)
+CREATE_LWIP_SYNC_NODE(2, udp_noPorts)
+CREATE_LWIP_SYNC_NODE(3, udp_inErrors)
+CREATE_LWIP_SYNC_NODE(4, udp_outDatagrams)
+#if LWIP_IPV4
+CREATE_LWIP_SYNC_NODE(5, udp_Table)
+#endif /* LWIP_IPV4 */
+CREATE_LWIP_SYNC_NODE(7, udp_endpointTable)
+CREATE_LWIP_SYNC_NODE(8, udp_HCInDatagrams)
+CREATE_LWIP_SYNC_NODE(9, udp_HCOutDatagrams)
+
+static const struct snmp_node* const udp_nodes[] = {
+  &SYNC_NODE_NAME(udp_inDatagrams).node.node,
+  &SYNC_NODE_NAME(udp_noPorts).node.node,
+  &SYNC_NODE_NAME(udp_inErrors).node.node,
+  &SYNC_NODE_NAME(udp_outDatagrams).node.node,
+#if LWIP_IPV4
+  &SYNC_NODE_NAME(udp_Table).node.node,
+#endif /* LWIP_IPV4 */
+  &SYNC_NODE_NAME(udp_endpointTable).node.node,
+  &SYNC_NODE_NAME(udp_HCInDatagrams).node.node,
+  &SYNC_NODE_NAME(udp_HCOutDatagrams).node.node
+};
+
+const struct snmp_tree_node snmp_mib2_udp_root = SNMP_CREATE_TREE_NODE(7, udp_nodes);
+#endif /* LWIP_SNMP && SNMP_LWIP_MIB2 && LWIP_UDP */

ext/lwip/src/apps/snmp/snmp_msg.h

@@ -0,0 +1,193 @@
+/**
+ * @file
+ * SNMP Agent message handling structures (internal API, do not use in client code).
+ */
+
+/*
+ * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
+ * Copyright (c) 2016 Elias Oenal.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Christiaan Simons <christiaan.simons@axon.tv>
+ *         Martin Hentschel <info@cl-soft.de>
+ *         Elias Oenal <lwip@eliasoenal.com>
+ */
+
+#ifndef LWIP_HDR_APPS_SNMP_MSG_H
+#define LWIP_HDR_APPS_SNMP_MSG_H
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP
+
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "snmp_pbuf_stream.h"
+#include "lwip/ip_addr.h"
+#include "lwip/err.h"
+
+#if LWIP_SNMP_V3
+#include "snmpv3_priv.h"
+#endif
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* The listen port of the SNMP agent. Clients have to make their requests to
+   this port. Most standard clients won't work if you change this! */
+#ifndef SNMP_IN_PORT
+#define SNMP_IN_PORT 161
+#endif
+/* The remote port the SNMP agent sends traps to. Most standard trap sinks won't
+   work if you change this! */
+#ifndef SNMP_TRAP_PORT
+#define SNMP_TRAP_PORT 162
+#endif
+
+/* version defines used in PDU */
+#define SNMP_VERSION_1  0
+#define SNMP_VERSION_2c 1
+#define SNMP_VERSION_3  3
+
+struct snmp_varbind_enumerator
+{
+  struct snmp_pbuf_stream pbuf_stream;
+  u16_t varbind_count;
+};
+
+typedef u8_t snmp_vb_enumerator_err_t;
+#define SNMP_VB_ENUMERATOR_ERR_OK            0
+#define SNMP_VB_ENUMERATOR_ERR_EOVB          1
+#define SNMP_VB_ENUMERATOR_ERR_ASN1ERROR     2
+#define SNMP_VB_ENUMERATOR_ERR_INVALIDLENGTH 3
+
+void snmp_vb_enumerator_init(struct snmp_varbind_enumerator* enumerator, struct pbuf* p, u16_t offset, u16_t length);
+snmp_vb_enumerator_err_t snmp_vb_enumerator_get_next(struct snmp_varbind_enumerator* enumerator, struct snmp_varbind* varbind);
+
+struct snmp_request
+{
+  /* Communication handle */
+  void *handle;
+  /* source IP address */
+  const ip_addr_t *source_ip;
+  /* source UDP port */
+  u16_t source_port;
+  /* incoming snmp version */
+  u8_t version;
+  /* community name (zero terminated) */
+  u8_t community[SNMP_MAX_COMMUNITY_STR_LEN + 1];
+  /* community string length (exclusive zero term) */
+  u16_t community_strlen;
+  /* request type */
+  u8_t request_type;
+  /* request ID */
+  s32_t request_id;
+  /* error status */
+  s32_t error_status;
+  /* error index */
+  s32_t error_index;
+  /* non-repeaters (getBulkRequest (SNMPv2c)) */
+  s32_t non_repeaters;
+  /* max-repetitions (getBulkRequest (SNMPv2c)) */
+  s32_t max_repetitions;
+  
+#if LWIP_SNMP_V3
+  s32_t msg_id;
+  s32_t msg_max_size;
+  u8_t  msg_flags;
+  s32_t msg_security_model;
+  u8_t  msg_authoritative_engine_id[SNMP_V3_MAX_ENGINE_ID_LENGTH];
+  u8_t  msg_authoritative_engine_id_len;
+  s32_t msg_authoritative_engine_boots;
+  s32_t msg_authoritative_engine_time;
+  u8_t  msg_user_name[SNMP_V3_MAX_USER_LENGTH];
+  u8_t  msg_user_name_len;
+  u8_t  msg_authentication_parameters[SNMP_V3_MAX_AUTH_PARAM_LENGTH];
+  u8_t  msg_privacy_parameters[SNMP_V3_MAX_PRIV_PARAM_LENGTH];
+  u8_t  context_engine_id[SNMP_V3_MAX_ENGINE_ID_LENGTH];
+  u8_t  context_engine_id_len;
+  u8_t  context_name[SNMP_V3_MAX_ENGINE_ID_LENGTH];
+  u8_t  context_name_len;
+#endif
+
+  struct pbuf *inbound_pbuf;
+  struct snmp_varbind_enumerator inbound_varbind_enumerator;
+  u16_t inbound_varbind_offset;
+  u16_t inbound_varbind_len;
+  u16_t inbound_padding_len;
+
+  struct pbuf *outbound_pbuf;
+  struct snmp_pbuf_stream outbound_pbuf_stream;
+  u16_t outbound_pdu_offset;
+  u16_t outbound_error_status_offset;
+  u16_t outbound_error_index_offset;
+  u16_t outbound_varbind_offset;
+#if LWIP_SNMP_V3
+  u16_t outbound_msg_global_data_offset;
+  u16_t outbound_msg_global_data_end;
+  u16_t outbound_msg_security_parameters_str_offset;
+  u16_t outbound_msg_security_parameters_seq_offset;
+  u16_t outbound_msg_security_parameters_end;
+  u16_t outbound_msg_authentication_parameters_offset;
+  u16_t outbound_scoped_pdu_seq_offset;
+  u16_t outbound_scoped_pdu_string_offset;
+#endif
+
+  u8_t value_buffer[SNMP_MAX_VALUE_SIZE];
+};
+
+/** A helper struct keeping length information about varbinds */
+struct snmp_varbind_len
+{
+  u8_t  vb_len_len;
+  u16_t vb_value_len;
+  u8_t  oid_len_len;
+  u16_t oid_value_len;
+  u8_t  value_len_len;
+  u16_t value_value_len;
+};
+
+/** Agent community string */
+extern const char *snmp_community;
+/** Agent community string for write access */
+extern const char *snmp_community_write;
+/** handle for sending traps */
+extern void* snmp_traps_handle;
+
+void snmp_receive(void *handle, struct pbuf *p, const ip_addr_t *source_ip, u16_t port);
+err_t snmp_sendto(void *handle, struct pbuf *p, const ip_addr_t *dst, u16_t port);
+u8_t snmp_get_local_ip_for_dst(void* handle, const ip_addr_t *dst, ip_addr_t *result);
+err_t snmp_varbind_length(struct snmp_varbind *varbind, struct snmp_varbind_len *len);
+err_t snmp_append_outbound_varbind(struct snmp_pbuf_stream *pbuf_stream, struct snmp_varbind* varbind);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LWIP_SNMP */
+
+#endif /* LWIP_HDR_APPS_SNMP_MSG_H */

ext/lwip/src/apps/snmp/snmp_netconn.c

@@ -0,0 +1,120 @@
+/**
+ * @file
+ * SNMP netconn frontend.
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ */
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP && SNMP_USE_NETCONN
+
+#include "lwip/api.h"
+#include "lwip/ip.h"
+#include "lwip/udp.h"
+#include "snmp_msg.h"
+#include "lwip/sys.h"
+
+/** SNMP netconn API worker thread */
+static void
+snmp_netconn_thread(void *arg)
+{
+  struct netconn *conn;
+  struct netbuf *buf;
+  err_t err;
+  LWIP_UNUSED_ARG(arg);
+  
+  /* Bind to SNMP port with default IP address */
+ #if LWIP_IPV6
+  conn = netconn_new(NETCONN_UDP_IPV6);
+  netconn_bind(conn, IP6_ADDR_ANY, SNMP_IN_PORT);
+#else /* LWIP_IPV6 */
+  conn = netconn_new(NETCONN_UDP);
+  netconn_bind(conn, IP_ADDR_ANY, SNMP_IN_PORT);
+#endif /* LWIP_IPV6 */
+  LWIP_ERROR("snmp_netconn: invalid conn", (conn != NULL), return;);
+  
+  snmp_traps_handle = conn;
+
+  do {
+    err = netconn_recv(conn, &buf);
+
+    if (err == ERR_OK) {
+      snmp_receive(conn, buf->p, &buf->addr, buf->port);
+    }
+
+    if (buf != NULL) {
+      netbuf_delete(buf);
+    }
+  } while(1);
+}
+
+err_t 
+snmp_sendto(void *handle, struct pbuf *p, const ip_addr_t *dst, u16_t port)
+{
+  err_t result;
+  struct netbuf buf;
+  
+  memset(&buf, 0, sizeof(buf));
+  buf.p = p;
+  result = netconn_sendto((struct netconn*)handle, &buf, dst, port);
+  
+  return result;
+}
+
+u8_t
+snmp_get_local_ip_for_dst(void* handle, const ip_addr_t *dst, ip_addr_t *result)
+{
+  struct netconn* conn = (struct netconn*)handle;
+  struct netif *dst_if;
+  const ip_addr_t* dst_ip;
+
+  LWIP_UNUSED_ARG(conn); /* unused in case of IPV4 only configuration */
+
+  ip_route_get_local_ip(&conn->pcb.udp->local_ip, dst, dst_if, dst_ip);
+
+  if ((dst_if != NULL) && (dst_ip != NULL)) {
+    ip_addr_copy(*result, *dst_ip);
+    return 1;
+  } else {
+    return 0;
+  }
+}
+
+/**
+ * Starts SNMP Agent.
+ */
+void
+snmp_init(void)
+{
+  sys_thread_new("snmp_netconn", snmp_netconn_thread, NULL, SNMP_STACK_SIZE, SNMP_THREAD_PRIO);
+}
+
+#endif /* LWIP_SNMP && SNMP_USE_NETCONN */

ext/lwip/src/apps/snmp/snmp_pbuf_stream.c

@@ -0,0 +1,156 @@
+/**
+ * @file
+ * SNMP pbuf stream wrapper implementation (internal API, do not use in client code).
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Martin Hentschel <info@cl-soft.de>
+ *
+ */
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
+
+#include "snmp_pbuf_stream.h"
+#include "lwip/def.h"
+#include <string.h>
+
+err_t
+snmp_pbuf_stream_init(struct snmp_pbuf_stream* pbuf_stream, struct pbuf* p, u16_t offset, u16_t length)
+{
+  pbuf_stream->offset = offset;
+  pbuf_stream->length = length;
+  pbuf_stream->pbuf   = p;
+
+  return ERR_OK;
+}
+
+err_t
+snmp_pbuf_stream_read(struct snmp_pbuf_stream* pbuf_stream, u8_t* data)
+{
+  if (pbuf_stream->length == 0) {
+    return ERR_BUF;
+  }
+
+  if (pbuf_copy_partial(pbuf_stream->pbuf, data, 1, pbuf_stream->offset) == 0) {
+    return ERR_BUF;
+  }
+
+  pbuf_stream->offset++;
+  pbuf_stream->length--;
+
+  return ERR_OK;
+}
+
+err_t
+snmp_pbuf_stream_write(struct snmp_pbuf_stream* pbuf_stream, u8_t data)
+{
+  return snmp_pbuf_stream_writebuf(pbuf_stream, &data, 1);
+}
+
+err_t
+snmp_pbuf_stream_writebuf(struct snmp_pbuf_stream* pbuf_stream, const void* buf, u16_t buf_len)
+{
+  if (pbuf_stream->length < buf_len) {
+    return ERR_BUF;
+  }
+
+  if (pbuf_take_at(pbuf_stream->pbuf, buf, buf_len, pbuf_stream->offset) != ERR_OK) {
+    return ERR_BUF;
+  }
+
+  pbuf_stream->offset += buf_len;
+  pbuf_stream->length -= buf_len;
+
+  return ERR_OK;
+}
+
+err_t
+snmp_pbuf_stream_writeto(struct snmp_pbuf_stream* pbuf_stream, struct snmp_pbuf_stream* target_pbuf_stream, u16_t len)
+{
+
+  if ((pbuf_stream == NULL) || (target_pbuf_stream == NULL)) {
+    return ERR_ARG;
+  }
+  if ((len > pbuf_stream->length) || (len > target_pbuf_stream->length)) {
+    return ERR_ARG;
+  }
+
+  if (len == 0) {
+    len = LWIP_MIN(pbuf_stream->length, target_pbuf_stream->length);
+  }
+
+  while (len > 0) {
+    u16_t chunk_len;
+    err_t err;
+    u16_t target_offset;
+    struct pbuf* pbuf = pbuf_skip(pbuf_stream->pbuf, pbuf_stream->offset, &target_offset);
+
+    if ((pbuf == NULL) || (pbuf->len == 0)) {
+      return ERR_BUF;
+    }
+
+    chunk_len = LWIP_MIN(len, pbuf->len);
+    err = snmp_pbuf_stream_writebuf(target_pbuf_stream, &((u8_t*)pbuf->payload)[target_offset], chunk_len);
+    if (err != ERR_OK) {
+      return err;
+    }
+
+    pbuf_stream->offset   += chunk_len;
+    pbuf_stream->length   -= chunk_len;
+    len -= chunk_len;
+  }
+
+  return ERR_OK;
+}
+
+err_t
+snmp_pbuf_stream_seek(struct snmp_pbuf_stream* pbuf_stream, s32_t offset)
+{
+  if ((offset < 0) || (offset > pbuf_stream->length)) {
+    /* we cannot seek backwards or forward behind stream end */
+    return ERR_ARG;
+  }
+
+  pbuf_stream->offset += (u16_t)offset;
+  pbuf_stream->length -= (u16_t)offset;
+
+  return ERR_OK;
+}
+
+err_t
+snmp_pbuf_stream_seek_abs(struct snmp_pbuf_stream* pbuf_stream, u32_t offset)
+{
+  s32_t rel_offset = offset - pbuf_stream->offset;
+  return snmp_pbuf_stream_seek(pbuf_stream, rel_offset);
+}
+
+#endif /* LWIP_SNMP */

ext/lwip/src/apps/snmp/snmp_pbuf_stream.h

@@ -0,0 +1,73 @@
+/**
+ * @file
+ * SNMP pbuf stream wrapper (internal API, do not use in client code).
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Martin Hentschel <info@cl-soft.de>
+ *
+ */
+
+#ifndef LWIP_HDR_APPS_SNMP_PBUF_STREAM_H
+#define LWIP_HDR_APPS_SNMP_PBUF_STREAM_H
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP
+
+#include "lwip/err.h"
+#include "lwip/pbuf.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct snmp_pbuf_stream
+{
+  struct pbuf* pbuf;
+  u16_t offset;
+  u16_t length;
+};
+
+err_t snmp_pbuf_stream_init(struct snmp_pbuf_stream* pbuf_stream, struct pbuf* p, u16_t offset, u16_t length);
+err_t snmp_pbuf_stream_read(struct snmp_pbuf_stream* pbuf_stream, u8_t* data);
+err_t snmp_pbuf_stream_write(struct snmp_pbuf_stream* pbuf_stream, u8_t data);
+err_t snmp_pbuf_stream_writebuf(struct snmp_pbuf_stream* pbuf_stream, const void* buf, u16_t buf_len);
+err_t snmp_pbuf_stream_writeto(struct snmp_pbuf_stream* pbuf_stream, struct snmp_pbuf_stream* target_pbuf_stream, u16_t len);
+err_t snmp_pbuf_stream_seek(struct snmp_pbuf_stream* pbuf_stream, s32_t offset);
+err_t snmp_pbuf_stream_seek_abs(struct snmp_pbuf_stream* pbuf_stream, u32_t offset);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LWIP_SNMP */
+
+#endif /* LWIP_HDR_APPS_SNMP_PBUF_STREAM_H */

ext/lwip/src/apps/snmp/snmp_raw.c

@@ -0,0 +1,100 @@
+/**
+ * @file
+ * SNMP RAW API frontend.
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ */
+
+#include "lwip/apps/snmp_opts.h"
+#include "lwip/ip_addr.h"
+
+#if LWIP_SNMP && SNMP_USE_RAW
+
+#include "lwip/udp.h"
+#include "lwip/ip.h"
+#include "snmp_msg.h"
+
+/* lwIP UDP receive callback function */
+static void
+snmp_recv(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
+{
+  LWIP_UNUSED_ARG(arg);
+
+  snmp_receive(pcb, p, addr, port);
+
+  pbuf_free(p);
+}
+
+err_t 
+snmp_sendto(void *handle, struct pbuf *p, const ip_addr_t *dst, u16_t port)
+{
+  return udp_sendto((struct udp_pcb*)handle, p, dst, port);
+}
+
+u8_t
+snmp_get_local_ip_for_dst(void* handle, const ip_addr_t *dst, ip_addr_t *result)
+{
+  struct udp_pcb* udp_pcb = (struct udp_pcb*)handle;
+  struct netif *dst_if;
+  const ip_addr_t* dst_ip;
+
+  LWIP_UNUSED_ARG(udp_pcb); /* unused in case of IPV4 only configuration */
+
+  ip_route_get_local_ip(&udp_pcb->local_ip, dst, dst_if, dst_ip);
+
+  if ((dst_if != NULL) && (dst_ip != NULL)) {
+    ip_addr_copy(*result, *dst_ip);
+    return 1;
+  } else {
+    return 0;
+  }
+}
+
+/**
+ * @ingroup snmp_core
+ * Starts SNMP Agent.
+ * Allocates UDP pcb and binds it to IP_ADDR_ANY port 161.
+ */
+void
+snmp_init(void)
+{
+  err_t err;
+  
+  struct udp_pcb *snmp_pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
+  LWIP_ERROR("snmp_raw: no PCB", (snmp_pcb != NULL), return;);
+
+  snmp_traps_handle = snmp_pcb;
+
+  udp_recv(snmp_pcb, snmp_recv, (void *)SNMP_IN_PORT);
+  err = udp_bind(snmp_pcb, IP_ANY_TYPE, SNMP_IN_PORT);
+  LWIP_ERROR("snmp_raw: Unable to bind PCB", (err == ERR_OK), return;);
+}
+
+#endif /* LWIP_SNMP && SNMP_USE_RAW */

ext/lwip/src/apps/snmp/snmp_scalar.c

@@ -0,0 +1,220 @@
+/**
+ * @file
+ * SNMP scalar node support implementation.
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Martin Hentschel <info@cl-soft.de>
+ *
+ */
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/apps/snmp_scalar.h"
+#include "lwip/apps/snmp_core.h"
+
+static s16_t snmp_scalar_array_get_value(struct snmp_node_instance* instance, void* value);
+static snmp_err_t  snmp_scalar_array_set_test(struct snmp_node_instance* instance, u16_t value_len, void* value);
+static snmp_err_t  snmp_scalar_array_set_value(struct snmp_node_instance* instance, u16_t value_len, void* value);
+
+snmp_err_t 
+snmp_scalar_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  const struct snmp_scalar_node* scalar_node = (const struct snmp_scalar_node*)(const void*)instance->node;
+
+  LWIP_UNUSED_ARG(root_oid);
+  LWIP_UNUSED_ARG(root_oid_len);
+
+  /* scalar only has one dedicated instance: .0 */
+  if ((instance->instance_oid.len != 1) || (instance->instance_oid.id[0] != 0)) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  instance->access    = scalar_node->access;
+  instance->asn1_type = scalar_node->asn1_type;
+  instance->get_value = scalar_node->get_value;
+  instance->set_test  = scalar_node->set_test;
+  instance->set_value = scalar_node->set_value;
+  return SNMP_ERR_NOERROR;
+}
+
+snmp_err_t 
+snmp_scalar_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  /* because our only instance is .0 we can only return a next instance if no instance oid is passed */
+  if (instance->instance_oid.len == 0) {
+    instance->instance_oid.len   = 1;
+    instance->instance_oid.id[0] = 0;
+
+    return snmp_scalar_get_instance(root_oid, root_oid_len, instance);
+  }
+
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+
+snmp_err_t
+snmp_scalar_array_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  LWIP_UNUSED_ARG(root_oid);
+  LWIP_UNUSED_ARG(root_oid_len);
+
+  if ((instance->instance_oid.len == 2) && (instance->instance_oid.id[1] == 0)) {
+    const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
+    const struct snmp_scalar_array_node_def* array_node_def = array_node->array_nodes;
+    u32_t i = 0;
+
+    while (i < array_node->array_node_count) {
+      if (array_node_def->oid == instance->instance_oid.id[0]) {
+        break;
+      }
+
+      array_node_def++;
+      i++;
+    }
+
+    if (i < array_node->array_node_count) {
+      instance->access              = array_node_def->access;
+      instance->asn1_type           = array_node_def->asn1_type;
+      instance->get_value           = snmp_scalar_array_get_value;
+      instance->set_test            = snmp_scalar_array_set_test;
+      instance->set_value           = snmp_scalar_array_set_value;
+      instance->reference.const_ptr = array_node_def;
+
+      return SNMP_ERR_NOERROR;
+    }
+  }
+
+  return SNMP_ERR_NOSUCHINSTANCE;
+}
+
+snmp_err_t
+snmp_scalar_array_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
+  const struct snmp_scalar_array_node_def* array_node_def = array_node->array_nodes;
+  const struct snmp_scalar_array_node_def* result = NULL;
+
+  LWIP_UNUSED_ARG(root_oid);
+  LWIP_UNUSED_ARG(root_oid_len);
+
+  if ((instance->instance_oid.len == 0) && (array_node->array_node_count > 0)) {
+    /* return node with lowest OID */
+    u16_t i = 0;
+    
+    result = array_node_def;
+    array_node_def++;
+
+    for (i = 1; i < array_node->array_node_count; i++) {
+      if (array_node_def->oid < result->oid) {
+        result = array_node_def;
+      }
+      array_node_def++;
+    }
+  } else if (instance->instance_oid.len >= 1) {
+    if (instance->instance_oid.len == 1) {
+      /* if we have the requested OID we return its instance, otherwise we search for the next available */    
+      u16_t i = 0;
+      while (i < array_node->array_node_count) {
+        if (array_node_def->oid == instance->instance_oid.id[0]) {
+          result = array_node_def;
+          break;
+        }
+
+        array_node_def++;
+        i++;
+      }
+    }
+    if (result == NULL) {
+      u32_t oid_dist = 0xFFFFFFFFUL;
+      u16_t i        = 0;
+      array_node_def = array_node->array_nodes; /* may be already at the end when if case before was executed without result -> reinitialize to start */
+      while (i < array_node->array_node_count) {
+        if ((array_node_def->oid > instance->instance_oid.id[0]) &&
+            ((u32_t)(array_node_def->oid - instance->instance_oid.id[0]) < oid_dist)) {
+          result   = array_node_def;
+          oid_dist = array_node_def->oid - instance->instance_oid.id[0];
+        }
+
+        array_node_def++;
+        i++;
+      }
+    }
+  }
+
+  if (result == NULL) {
+    /* nothing to return */
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  instance->instance_oid.len   = 2;
+  instance->instance_oid.id[0] = result->oid;
+  instance->instance_oid.id[1] = 0;
+  
+  instance->access              = result->access;
+  instance->asn1_type           = result->asn1_type;
+  instance->get_value           = snmp_scalar_array_get_value;
+  instance->set_test            = snmp_scalar_array_set_test;
+  instance->set_value           = snmp_scalar_array_set_value;
+  instance->reference.const_ptr = result;
+
+  return SNMP_ERR_NOERROR;
+}
+
+static s16_t
+snmp_scalar_array_get_value(struct snmp_node_instance* instance, void* value)
+{
+  const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
+  const struct snmp_scalar_array_node_def* array_node_def = (const struct snmp_scalar_array_node_def*)instance->reference.const_ptr;
+
+  return array_node->get_value(array_node_def, value);
+}
+
+static snmp_err_t
+snmp_scalar_array_set_test(struct snmp_node_instance* instance, u16_t value_len, void* value)
+{
+  const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
+  const struct snmp_scalar_array_node_def* array_node_def = (const struct snmp_scalar_array_node_def*)instance->reference.const_ptr;
+
+  return array_node->set_test(array_node_def, value_len, value);
+}
+
+static snmp_err_t
+snmp_scalar_array_set_value(struct snmp_node_instance* instance, u16_t value_len, void* value)
+{
+  const struct snmp_scalar_array_node* array_node = (const struct snmp_scalar_array_node*)(const void*)instance->node;
+  const struct snmp_scalar_array_node_def* array_node_def = (const struct snmp_scalar_array_node_def*)instance->reference.const_ptr;
+
+  return array_node->set_value(array_node_def, value_len, value);
+}
+
+#endif /* LWIP_SNMP */

ext/lwip/src/apps/snmp/snmp_table.c

@@ -0,0 +1,343 @@
+/**
+ * @file
+ * SNMP table support implementation.
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Martin Hentschel <info@cl-soft.de>
+ *
+ */
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/apps/snmp_core.h"
+#include "lwip/apps/snmp_table.h"
+#include <string.h>
+
+snmp_err_t snmp_table_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  snmp_err_t ret = SNMP_ERR_NOSUCHINSTANCE;
+  const struct snmp_table_node* table_node = (const struct snmp_table_node*)(const void*)instance->node;
+
+  LWIP_UNUSED_ARG(root_oid);
+  LWIP_UNUSED_ARG(root_oid_len);
+
+  /* check min. length (fixed row entry definition, column, row instance oid with at least one entry */
+  /* fixed row entry always has oid 1 */
+  if ((instance->instance_oid.len >= 3) && (instance->instance_oid.id[0] == 1)) {
+    /* search column */
+    const struct snmp_table_col_def* col_def = table_node->columns;
+    u16_t i = table_node->column_count;
+    while (i > 0) {
+      if (col_def->index == instance->instance_oid.id[1]) {
+        break;
+      }
+      
+      col_def++;
+      i--;
+    }
+
+    if (i > 0) {
+      /* everything may be overwritten by get_cell_instance_method() in order to implement special handling for single columns/cells */
+      instance->asn1_type = col_def->asn1_type;
+      instance->access    = col_def->access;
+      instance->get_value = table_node->get_value;
+      instance->set_test  = table_node->set_test;
+      instance->set_value = table_node->set_value;
+
+      ret = table_node->get_cell_instance(
+        &(instance->instance_oid.id[1]),
+        &(instance->instance_oid.id[2]),
+        instance->instance_oid.len-2,
+        instance);
+    }
+  }
+
+  return ret;
+}
+
+snmp_err_t snmp_table_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  const struct snmp_table_node* table_node = (const struct snmp_table_node*)(const void*)instance->node;
+  const struct snmp_table_col_def* col_def;
+  struct snmp_obj_id row_oid;
+  u32_t column = 0;
+  snmp_err_t result;
+
+  LWIP_UNUSED_ARG(root_oid);
+  LWIP_UNUSED_ARG(root_oid_len);
+
+  /* check that first part of id is 0 or 1, referencing fixed row entry */
+  if ((instance->instance_oid.len > 0) && (instance->instance_oid.id[0] > 1)) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+  if (instance->instance_oid.len > 1) {
+    column = instance->instance_oid.id[1];
+  }
+  if (instance->instance_oid.len > 2) {
+    snmp_oid_assign(&row_oid, &(instance->instance_oid.id[2]), instance->instance_oid.len - 2);
+  } else {
+    row_oid.len = 0;
+  }
+
+  instance->get_value    = table_node->get_value;
+  instance->set_test     = table_node->set_test;
+  instance->set_value    = table_node->set_value;
+
+  /* resolve column and value */
+  do {
+    u16_t i;
+    const struct snmp_table_col_def* next_col_def = NULL;
+    col_def = table_node->columns;
+
+    for (i = 0; i < table_node->column_count; i++) {
+      if (col_def->index == column) {
+        next_col_def = col_def;
+        break;
+      } else if ((col_def->index > column) && ((next_col_def == NULL) || (col_def->index < next_col_def->index))) {
+        next_col_def = col_def;
+      }
+      col_def++;
+    }
+
+    if (next_col_def == NULL) {
+      /* no further column found */
+      return SNMP_ERR_NOSUCHINSTANCE;
+    }
+
+    instance->asn1_type          = next_col_def->asn1_type;
+    instance->access             = next_col_def->access;
+
+    result = table_node->get_next_cell_instance(
+      &next_col_def->index,
+      &row_oid,
+      instance);
+
+    if (result == SNMP_ERR_NOERROR) {
+      col_def = next_col_def;
+      break;
+    }
+
+    row_oid.len = 0; /* reset row_oid because we switch to next column and start with the first entry there */
+    column = next_col_def->index + 1;
+  } while (1);
+
+  /* build resulting oid */
+  instance->instance_oid.len   = 2;
+  instance->instance_oid.id[0] = 1;
+  instance->instance_oid.id[1] = col_def->index;
+  snmp_oid_append(&instance->instance_oid, row_oid.id, row_oid.len);
+
+  return SNMP_ERR_NOERROR;
+}
+
+
+snmp_err_t snmp_table_simple_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  snmp_err_t ret = SNMP_ERR_NOSUCHINSTANCE;
+  const struct snmp_table_simple_node* table_node = (const struct snmp_table_simple_node*)(const void*)instance->node;
+
+  LWIP_UNUSED_ARG(root_oid);
+  LWIP_UNUSED_ARG(root_oid_len);
+
+  /* check min. length (fixed row entry definition, column, row instance oid with at least one entry */
+  /* fixed row entry always has oid 1 */
+  if ((instance->instance_oid.len >= 3) && (instance->instance_oid.id[0] == 1)) {
+    ret = table_node->get_cell_value(
+      &(instance->instance_oid.id[1]),
+      &(instance->instance_oid.id[2]),
+      instance->instance_oid.len-2,
+      &instance->reference,
+      &instance->reference_len);
+
+    if (ret == SNMP_ERR_NOERROR) {
+      /* search column */
+      const struct snmp_table_simple_col_def* col_def = table_node->columns;
+      u32_t i = table_node->column_count;
+      while (i > 0) {
+        if (col_def->index == instance->instance_oid.id[1]) {
+          break;
+        }
+
+        col_def++;
+        i--;
+      }
+
+      if (i > 0) {
+        instance->asn1_type = col_def->asn1_type;
+        instance->access    = SNMP_NODE_INSTANCE_READ_ONLY;
+        instance->set_test  = NULL;
+        instance->set_value = NULL;
+
+        switch (col_def->data_type) {
+          case SNMP_VARIANT_VALUE_TYPE_U32:
+            instance->get_value = snmp_table_extract_value_from_u32ref;
+            break;
+          case SNMP_VARIANT_VALUE_TYPE_S32:
+            instance->get_value = snmp_table_extract_value_from_s32ref;
+            break;
+          case SNMP_VARIANT_VALUE_TYPE_PTR: /* fall through */
+          case SNMP_VARIANT_VALUE_TYPE_CONST_PTR:
+            instance->get_value = snmp_table_extract_value_from_refconstptr;
+            break;
+          default:
+            LWIP_DEBUGF(SNMP_DEBUG, ("snmp_table_simple_get_instance(): unknown column data_type: %d\n", col_def->data_type));
+            return SNMP_ERR_GENERROR;
+        }        
+
+        ret = SNMP_ERR_NOERROR;
+      } else {
+        ret = SNMP_ERR_NOSUCHINSTANCE;
+      }
+    } 
+  }
+
+  return ret;
+}
+
+snmp_err_t snmp_table_simple_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  const struct snmp_table_simple_node* table_node = (const struct snmp_table_simple_node*)(const void*)instance->node;
+  const struct snmp_table_simple_col_def* col_def;
+  struct snmp_obj_id row_oid;
+  u32_t column = 0;
+  snmp_err_t result;
+
+  LWIP_UNUSED_ARG(root_oid);
+  LWIP_UNUSED_ARG(root_oid_len);
+
+  /* check that first part of id is 0 or 1, referencing fixed row entry */
+  if ((instance->instance_oid.len > 0) && (instance->instance_oid.id[0] > 1)) {
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+  if (instance->instance_oid.len > 1) {
+    column = instance->instance_oid.id[1];
+  }
+  if (instance->instance_oid.len > 2) {
+    snmp_oid_assign(&row_oid, &(instance->instance_oid.id[2]), instance->instance_oid.len - 2);
+  } else {
+    row_oid.len = 0;
+  }
+
+  /* resolve column and value */
+  do {
+    u32_t i;
+    const struct snmp_table_simple_col_def* next_col_def = NULL;
+    col_def = table_node->columns;
+
+    for (i = 0; i < table_node->column_count; i++) {
+      if (col_def->index == column) {
+        next_col_def = col_def;
+        break;
+      } else if ((col_def->index > column) && ((next_col_def == NULL) ||
+                 (col_def->index < next_col_def->index))) {
+        next_col_def = col_def;
+      }
+      col_def++;
+    }
+
+    if (next_col_def == NULL) {
+      /* no further column found */
+      return SNMP_ERR_NOSUCHINSTANCE;
+    }
+
+    result = table_node->get_next_cell_instance_and_value(
+      &next_col_def->index,
+      &row_oid,
+      &instance->reference,
+      &instance->reference_len);
+
+    if (result == SNMP_ERR_NOERROR) {
+      col_def = next_col_def;
+      break;
+    }
+
+    row_oid.len = 0; /* reset row_oid because we switch to next column and start with the first entry there */
+    column = next_col_def->index + 1;
+  }
+  while (1);
+
+  instance->asn1_type = col_def->asn1_type;
+  instance->access    = SNMP_NODE_INSTANCE_READ_ONLY;
+  instance->set_test  = NULL;
+  instance->set_value = NULL;
+
+  switch (col_def->data_type) {
+    case SNMP_VARIANT_VALUE_TYPE_U32:
+      instance->get_value = snmp_table_extract_value_from_u32ref;
+      break;
+    case SNMP_VARIANT_VALUE_TYPE_S32:
+      instance->get_value = snmp_table_extract_value_from_s32ref;
+      break;
+    case SNMP_VARIANT_VALUE_TYPE_PTR: /* fall through */
+    case SNMP_VARIANT_VALUE_TYPE_CONST_PTR:
+      instance->get_value = snmp_table_extract_value_from_refconstptr;
+      break;
+    default:
+      LWIP_DEBUGF(SNMP_DEBUG, ("snmp_table_simple_get_instance(): unknown column data_type: %d\n", col_def->data_type));
+      return SNMP_ERR_GENERROR;
+  }
+
+  /* build resulting oid */
+  instance->instance_oid.len   = 2;
+  instance->instance_oid.id[0] = 1;
+  instance->instance_oid.id[1] = col_def->index;
+  snmp_oid_append(&instance->instance_oid, row_oid.id, row_oid.len);
+
+  return SNMP_ERR_NOERROR;
+}
+
+
+s16_t
+snmp_table_extract_value_from_s32ref(struct snmp_node_instance* instance, void* value)
+{
+  s32_t *dst = (s32_t*)value;
+  *dst = instance->reference.s32;
+  return sizeof(*dst);
+}
+
+s16_t
+snmp_table_extract_value_from_u32ref(struct snmp_node_instance* instance, void* value)
+{
+  u32_t *dst = (u32_t*)value;
+  *dst = instance->reference.u32;
+  return sizeof(*dst);
+}
+
+s16_t
+snmp_table_extract_value_from_refconstptr(struct snmp_node_instance* instance, void* value)
+{
+  MEMCPY(value, instance->reference.const_ptr, instance->reference_len);
+  return (u16_t)instance->reference_len;
+}
+
+#endif /* LWIP_SNMP */

ext/lwip/src/apps/snmp/snmp_threadsync.c

@@ -0,0 +1,218 @@
+/**
+ * @file
+ * SNMP thread synchronization implementation.
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dirk Ziegelmeier <dziegel@gmx.de>
+ */
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP && (NO_SYS == 0) /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/apps/snmp_threadsync.h"
+#include "lwip/apps/snmp_core.h"
+#include "lwip/sys.h"
+#include <string.h>
+        
+static void
+call_synced_function(struct threadsync_data *call_data, snmp_threadsync_called_fn fn)
+{
+  sys_mutex_lock(&call_data->threadsync_node->instance->sem_usage_mutex);
+  call_data->threadsync_node->instance->sync_fn(fn, call_data);
+  sys_sem_wait(&call_data->threadsync_node->instance->sem);
+  sys_mutex_unlock(&call_data->threadsync_node->instance->sem_usage_mutex);
+}
+
+static void
+threadsync_get_value_synced(void *ctx)
+{
+  struct threadsync_data *call_data = (struct threadsync_data*)ctx;
+
+  call_data->retval.s16 = call_data->proxy_instance.get_value(&call_data->proxy_instance, call_data->arg1.value);
+
+  sys_sem_signal(&call_data->threadsync_node->instance->sem);
+}
+
+static s16_t
+threadsync_get_value(struct snmp_node_instance* instance, void* value)
+{
+  struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr;
+
+  call_data->arg1.value = value;
+  call_synced_function(call_data, threadsync_get_value_synced);
+
+  return call_data->retval.s16;
+}
+
+static void
+threadsync_set_test_synced(void *ctx)
+{
+  struct threadsync_data *call_data = (struct threadsync_data*)ctx;
+
+  call_data->retval.err = call_data->proxy_instance.set_test(&call_data->proxy_instance, call_data->arg2.len, call_data->arg1.value);
+
+  sys_sem_signal(&call_data->threadsync_node->instance->sem);
+}
+
+static snmp_err_t
+threadsync_set_test(struct snmp_node_instance* instance, u16_t len, void *value)
+{
+  struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr;
+
+  call_data->arg1.value = value;
+  call_data->arg2.len = len;
+  call_synced_function(call_data, threadsync_set_test_synced);
+
+  return call_data->retval.err;
+}
+
+static void
+threadsync_set_value_synced(void *ctx)
+{
+  struct threadsync_data *call_data = (struct threadsync_data*)ctx;
+
+  call_data->retval.err = call_data->proxy_instance.set_value(&call_data->proxy_instance, call_data->arg2.len, call_data->arg1.value);
+
+  sys_sem_signal(&call_data->threadsync_node->instance->sem);
+}
+
+static snmp_err_t
+threadsync_set_value(struct snmp_node_instance* instance, u16_t len, void *value)
+{
+  struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr;
+
+  call_data->arg1.value = value;
+  call_data->arg2.len = len;
+  call_synced_function(call_data, threadsync_set_value_synced);
+  
+  return call_data->retval.err;
+}
+
+static void
+threadsync_release_instance_synced(void* ctx)
+{
+  struct threadsync_data *call_data = (struct threadsync_data*)ctx;
+  
+  call_data->proxy_instance.release_instance(&call_data->proxy_instance);
+
+  sys_sem_signal(&call_data->threadsync_node->instance->sem);
+}
+
+static void
+threadsync_release_instance(struct snmp_node_instance *instance)
+{
+  struct threadsync_data *call_data = (struct threadsync_data*)instance->reference.ptr;
+  
+  if (call_data->proxy_instance.release_instance != NULL) {
+    call_synced_function(call_data, threadsync_release_instance_synced);
+  }
+}
+
+static void
+get_instance_synced(void* ctx)
+{
+  struct threadsync_data *call_data   = (struct threadsync_data*)ctx;
+  const struct snmp_leaf_node *leaf   = (const struct snmp_leaf_node*)(const void*)call_data->proxy_instance.node;
+
+  call_data->retval.err = leaf->get_instance(call_data->arg1.root_oid, call_data->arg2.root_oid_len, &call_data->proxy_instance);
+
+  sys_sem_signal(&call_data->threadsync_node->instance->sem);
+}
+
+static void
+get_next_instance_synced(void* ctx)
+{
+  struct threadsync_data *call_data   = (struct threadsync_data*)ctx;
+  const struct snmp_leaf_node *leaf   = (const struct snmp_leaf_node*)(const void*)call_data->proxy_instance.node;
+
+  call_data->retval.err = leaf->get_next_instance(call_data->arg1.root_oid, call_data->arg2.root_oid_len, &call_data->proxy_instance);
+
+  sys_sem_signal(&call_data->threadsync_node->instance->sem);
+}
+
+static snmp_err_t
+do_sync(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance, snmp_threadsync_called_fn fn)
+{
+  const struct snmp_threadsync_node *threadsync_node = (const struct snmp_threadsync_node*)(const void*)instance->node;
+  struct threadsync_data *call_data = &threadsync_node->instance->data;
+
+  if (threadsync_node->node.node.oid != threadsync_node->target->node.oid) {
+    LWIP_DEBUGF(SNMP_DEBUG, ("Sync node OID does not match target node OID"));
+    return SNMP_ERR_NOSUCHINSTANCE;
+  }
+
+  memset(&call_data->proxy_instance, 0, sizeof(call_data->proxy_instance));
+
+  instance->reference.ptr = call_data;
+  snmp_oid_assign(&call_data->proxy_instance.instance_oid, instance->instance_oid.id, instance->instance_oid.len);
+
+  call_data->proxy_instance.node = &threadsync_node->target->node;
+  call_data->threadsync_node     = threadsync_node;
+
+  call_data->arg1.root_oid       = root_oid;
+  call_data->arg2.root_oid_len   = root_oid_len;
+  call_synced_function(call_data, fn);
+
+  if (call_data->retval.err == SNMP_ERR_NOERROR) {
+    instance->access           = call_data->proxy_instance.access;
+    instance->asn1_type        = call_data->proxy_instance.asn1_type;
+    instance->release_instance = threadsync_release_instance;
+    instance->get_value        = (call_data->proxy_instance.get_value != NULL)? threadsync_get_value : NULL;
+    instance->set_value        = (call_data->proxy_instance.set_value != NULL)? threadsync_set_value : NULL;
+    instance->set_test         = (call_data->proxy_instance.set_test != NULL)?  threadsync_set_test  : NULL;
+    snmp_oid_assign(&instance->instance_oid, call_data->proxy_instance.instance_oid.id, call_data->proxy_instance.instance_oid.len);
+  }
+
+  return call_data->retval.err;
+}
+
+snmp_err_t
+snmp_threadsync_get_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  return do_sync(root_oid, root_oid_len, instance, get_instance_synced);
+}
+
+snmp_err_t
+snmp_threadsync_get_next_instance(const u32_t *root_oid, u8_t root_oid_len, struct snmp_node_instance* instance)
+{
+  return do_sync(root_oid, root_oid_len, instance, get_next_instance_synced);
+}
+
+/** Initializes thread synchronization instance */
+void snmp_threadsync_init(struct snmp_threadsync_instance *instance, snmp_threadsync_synchronizer_fn sync_fn)
+{
+  err_t err = sys_mutex_new(&instance->sem_usage_mutex);
+  LWIP_ASSERT("Failed to set up mutex", err == ERR_OK);
+  err = sys_sem_new(&instance->sem, 0);
+  LWIP_ASSERT("Failed to set up semaphore", err == ERR_OK);
+  instance->sync_fn = sync_fn;
+}
+
+#endif /* LWIP_SNMP */

ext/lwip/src/apps/snmp/snmp_traps.c

@@ -0,0 +1,443 @@
+/**
+ * @file
+ * SNMPv1 traps implementation.
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Martin Hentschel
+ *         Christiaan Simons <christiaan.simons@axon.tv>
+ *
+ */
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
+
+#include <string.h>
+
+#include "lwip/snmp.h"
+#include "lwip/sys.h"
+#include "lwip/apps/snmp.h"
+#include "lwip/apps/snmp_core.h"
+#include "snmp_msg.h"
+#include "snmp_asn1.h"
+#include "snmp_core_priv.h"
+
+struct snmp_msg_trap
+{
+  /* source enterprise ID (sysObjectID) */
+  const struct snmp_obj_id *enterprise;
+  /* source IP address, raw network order format */
+  ip_addr_t sip;
+  /* generic trap code */
+  u32_t gen_trap;
+  /* specific trap code */
+  u32_t spc_trap;
+  /* timestamp */
+  u32_t ts;
+  /* snmp_version */
+  u32_t snmp_version;
+
+  /* output trap lengths used in ASN encoding */
+  /* encoding pdu length */
+  u16_t pdulen;
+  /* encoding community length */
+  u16_t comlen;
+  /* encoding sequence length */
+  u16_t seqlen;
+  /* encoding varbinds sequence length */
+  u16_t vbseqlen;
+};
+
+static u16_t snmp_trap_varbind_sum(struct snmp_msg_trap *trap, struct snmp_varbind *varbinds);
+static u16_t snmp_trap_header_sum(struct snmp_msg_trap *trap, u16_t vb_len);
+static void snmp_trap_header_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_stream);
+static void snmp_trap_varbind_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_stream, struct snmp_varbind *varbinds);
+
+/** Agent community string for sending traps */
+extern const char *snmp_community_trap;
+
+void* snmp_traps_handle;
+
+struct snmp_trap_dst
+{
+  /* destination IP address in network order */
+  ip_addr_t dip;
+  /* set to 0 when disabled, >0 when enabled */
+  u8_t enable;
+};
+static struct snmp_trap_dst trap_dst[SNMP_TRAP_DESTINATIONS];
+
+static u8_t snmp_auth_traps_enabled = 0;
+
+/**
+ * @ingroup snmp_traps
+ * Sets enable switch for this trap destination.
+ * @param dst_idx index in 0 .. SNMP_TRAP_DESTINATIONS-1
+ * @param enable switch if 0 destination is disabled >0 enabled.
+ */
+void
+snmp_trap_dst_enable(u8_t dst_idx, u8_t enable)
+{
+  if (dst_idx < SNMP_TRAP_DESTINATIONS) {
+    trap_dst[dst_idx].enable = enable;
+  }
+}
+
+/**
+ * @ingroup snmp_traps
+ * Sets IPv4 address for this trap destination.
+ * @param dst_idx index in 0 .. SNMP_TRAP_DESTINATIONS-1
+ * @param dst IPv4 address in host order.
+ */
+void
+snmp_trap_dst_ip_set(u8_t dst_idx, const ip_addr_t *dst)
+{
+  if (dst_idx < SNMP_TRAP_DESTINATIONS) {
+    ip_addr_set(&trap_dst[dst_idx].dip, dst);
+  }
+}
+
+/**
+ * @ingroup snmp_traps
+ * Enable/disable authentication traps
+ */
+void
+snmp_set_auth_traps_enabled(u8_t enable)
+{
+  snmp_auth_traps_enabled = enable;
+}
+
+/**
+ * @ingroup snmp_traps
+ * Get authentication traps enabled state
+ */
+u8_t
+snmp_get_auth_traps_enabled(void)
+{
+  return snmp_auth_traps_enabled;
+}
+
+
+/**
+ * Sends an generic or enterprise specific trap message.
+ *
+ * @param generic_trap is the trap code
+ * @param eoid points to enterprise object identifier
+ * @param specific_trap used for enterprise traps when generic_trap == 6
+ * @return ERR_OK when success, ERR_MEM if we're out of memory
+ *
+ * @note the use of the enterprise identifier field
+ * is per RFC1215.
+ * Use .iso.org.dod.internet.mgmt.mib-2.snmp for generic traps
+ * and .iso.org.dod.internet.private.enterprises.yourenterprise
+ * (sysObjectID) for specific traps.
+ */
+static err_t
+snmp_send_trap(const struct snmp_obj_id *device_enterprise_oid, s32_t generic_trap, s32_t specific_trap, struct snmp_varbind *varbinds)
+{
+  struct snmp_msg_trap trap_msg;
+  struct snmp_trap_dst *td;
+  struct pbuf *p;
+  u16_t i, tot_len;
+  err_t err = ERR_OK;
+
+  trap_msg.snmp_version = 0;
+
+  for (i = 0, td = &trap_dst[0]; i < SNMP_TRAP_DESTINATIONS; i++, td++) {
+    if ((td->enable != 0) && !ip_addr_isany(&td->dip)) {
+      /* lookup current source address for this dst */
+      if (snmp_get_local_ip_for_dst(snmp_traps_handle, &td->dip, &trap_msg.sip)) {
+        if (device_enterprise_oid == NULL) {
+          trap_msg.enterprise = snmp_get_device_enterprise_oid();
+        } else {
+          trap_msg.enterprise = device_enterprise_oid;
+        }
+
+        trap_msg.gen_trap = generic_trap;
+        if (generic_trap == SNMP_GENTRAP_ENTERPRISE_SPECIFIC) {
+          trap_msg.spc_trap = specific_trap;
+        } else {
+          trap_msg.spc_trap = 0;
+        }
+
+        MIB2_COPY_SYSUPTIME_TO(&trap_msg.ts);
+
+        /* pass 0, calculate length fields */
+        tot_len = snmp_trap_varbind_sum(&trap_msg, varbinds);
+        tot_len = snmp_trap_header_sum(&trap_msg, tot_len);
+
+        /* allocate pbuf(s) */
+        p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_RAM);
+        if (p != NULL) {
+          struct snmp_pbuf_stream pbuf_stream;
+          snmp_pbuf_stream_init(&pbuf_stream, p, 0, tot_len);
+
+          /* pass 1, encode packet ino the pbuf(s) */
+          snmp_trap_header_enc(&trap_msg, &pbuf_stream);
+          snmp_trap_varbind_enc(&trap_msg, &pbuf_stream, varbinds);
+
+          snmp_stats.outtraps++;
+          snmp_stats.outpkts++;
+
+          /** send to the TRAP destination */
+          snmp_sendto(snmp_traps_handle, p, &td->dip, SNMP_TRAP_PORT);
+          pbuf_free(p);
+        } else {
+          err = ERR_MEM;
+        }
+      } else {
+        /* routing error */
+        err = ERR_RTE;
+      }
+    }
+  }
+  return err;
+}
+
+/**
+ * @ingroup snmp_traps
+ *  Send generic SNMP trap
+ */
+err_t 
+snmp_send_trap_generic(s32_t generic_trap)
+{
+  static const struct snmp_obj_id oid = { 7, { 1, 3, 6, 1, 2, 1, 11 } };
+  return snmp_send_trap(&oid, generic_trap, 0, NULL);
+}
+
+/**
+ *@ingroup snmp_traps
+ * Send specific SNMP trap with variable bindings
+ */
+err_t
+snmp_send_trap_specific(s32_t specific_trap, struct snmp_varbind *varbinds)
+{
+  return snmp_send_trap(NULL, SNMP_GENTRAP_ENTERPRISE_SPECIFIC, specific_trap, varbinds);
+}
+
+/**
+ * @ingroup snmp_traps
+ * Send coldstart trap
+ */
+void
+snmp_coldstart_trap(void)
+{
+  snmp_send_trap_generic(SNMP_GENTRAP_COLDSTART);
+}
+
+/**
+ * @ingroup snmp_traps
+ * Send authentication failure trap (used internally by agent) 
+ */
+void
+snmp_authfail_trap(void)
+{
+  if (snmp_auth_traps_enabled != 0) {
+    snmp_send_trap_generic(SNMP_GENTRAP_AUTH_FAILURE);
+  }
+}
+
+static u16_t
+snmp_trap_varbind_sum(struct snmp_msg_trap *trap, struct snmp_varbind *varbinds)
+{
+  struct snmp_varbind *varbind;
+  u16_t tot_len;
+  u8_t tot_len_len;
+
+  tot_len = 0;
+  varbind = varbinds;
+  while (varbind != NULL) {
+    struct snmp_varbind_len len;
+
+    if (snmp_varbind_length(varbind, &len) == ERR_OK) {
+      tot_len += 1 + len.vb_len_len + len.vb_value_len;
+    }
+
+    varbind = varbind->next;
+  }
+
+  trap->vbseqlen = tot_len;
+  snmp_asn1_enc_length_cnt(trap->vbseqlen, &tot_len_len);
+  tot_len += 1 + tot_len_len;
+
+  return tot_len;
+}
+
+/**
+ * Sums trap header field lengths from tail to head and
+ * returns trap_header_lengths for second encoding pass.
+ *
+ * @param vb_len varbind-list length
+ * @param thl points to returned header lengths
+ * @return the required length for encoding the trap header
+ */
+static u16_t
+snmp_trap_header_sum(struct snmp_msg_trap *trap, u16_t vb_len)
+{
+  u16_t tot_len;
+  u16_t len;
+  u8_t lenlen;
+
+  tot_len = vb_len;
+
+  snmp_asn1_enc_u32t_cnt(trap->ts, &len);
+  snmp_asn1_enc_length_cnt(len, &lenlen);
+  tot_len += 1 + len + lenlen;
+
+  snmp_asn1_enc_s32t_cnt(trap->spc_trap, &len);
+  snmp_asn1_enc_length_cnt(len, &lenlen);
+  tot_len += 1 + len + lenlen;
+
+  snmp_asn1_enc_s32t_cnt(trap->gen_trap, &len);
+  snmp_asn1_enc_length_cnt(len, &lenlen);
+  tot_len += 1 + len + lenlen;
+
+  if (IP_IS_V6_VAL(trap->sip)) {
+#if LWIP_IPV6
+    len = sizeof(ip_2_ip6(&trap->sip)->addr);
+#endif
+  } else {
+#if LWIP_IPV4
+    len = sizeof(ip_2_ip4(&trap->sip)->addr);
+#endif
+  }
+  snmp_asn1_enc_length_cnt(len, &lenlen);
+  tot_len += 1 + len + lenlen;
+
+  snmp_asn1_enc_oid_cnt(trap->enterprise->id, trap->enterprise->len, &len);
+  snmp_asn1_enc_length_cnt(len, &lenlen);
+  tot_len += 1 + len + lenlen;
+
+  trap->pdulen = tot_len;
+  snmp_asn1_enc_length_cnt(trap->pdulen, &lenlen);
+  tot_len += 1 + lenlen;
+
+  trap->comlen = (u16_t)LWIP_MIN(strlen(snmp_community_trap), 0xFFFF);
+  snmp_asn1_enc_length_cnt(trap->comlen, &lenlen);
+  tot_len += 1 + lenlen + trap->comlen;
+
+  snmp_asn1_enc_s32t_cnt(trap->snmp_version, &len);
+  snmp_asn1_enc_length_cnt(len, &lenlen);
+  tot_len += 1 + len + lenlen;
+
+  trap->seqlen = tot_len;
+  snmp_asn1_enc_length_cnt(trap->seqlen, &lenlen);
+  tot_len += 1 + lenlen;
+
+  return tot_len;
+}
+
+static void
+snmp_trap_varbind_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_stream, struct snmp_varbind *varbinds)
+{
+  struct snmp_asn1_tlv tlv;
+  struct snmp_varbind *varbind;
+
+  varbind = varbinds;
+
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_SEQUENCE, 0, trap->vbseqlen);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+
+  while (varbind != NULL) {
+    snmp_append_outbound_varbind(pbuf_stream, varbind);
+
+    varbind = varbind->next;
+  }
+}
+
+/**
+ * Encodes trap header from head to tail.
+ */
+static void
+snmp_trap_header_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_stream)
+{
+  struct snmp_asn1_tlv tlv;
+
+  /* 'Message' sequence */
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_SEQUENCE, 0, trap->seqlen);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+
+  /* version */
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_INTEGER, 0, 0);
+  snmp_asn1_enc_s32t_cnt(trap->snmp_version, &tlv.value_len);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+  snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->snmp_version);
+
+  /* community */
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_OCTET_STRING, 0, trap->comlen);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+  snmp_asn1_enc_raw(pbuf_stream,  (const u8_t *)snmp_community_trap, trap->comlen);
+
+  /* 'PDU' sequence */
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, (SNMP_ASN1_CLASS_CONTEXT | SNMP_ASN1_CONTENTTYPE_CONSTRUCTED | SNMP_ASN1_CONTEXT_PDU_TRAP), 0, trap->pdulen);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+
+  /* object ID */
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_OBJECT_ID, 0, 0);
+  snmp_asn1_enc_oid_cnt(trap->enterprise->id, trap->enterprise->len, &tlv.value_len);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+  snmp_asn1_enc_oid(pbuf_stream, trap->enterprise->id, trap->enterprise->len);
+
+  /* IP addr */
+  if (IP_IS_V6_VAL(trap->sip)) {
+#if LWIP_IPV6
+    SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_IPADDR, 0, sizeof(ip_2_ip6(&trap->sip)->addr));
+    snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+    snmp_asn1_enc_raw(pbuf_stream, (const u8_t *)&ip_2_ip6(&trap->sip)->addr, sizeof(ip_2_ip6(&trap->sip)->addr));
+#endif
+  } else {
+#if LWIP_IPV4
+    SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_IPADDR, 0, sizeof(ip_2_ip4(&trap->sip)->addr));
+    snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+    snmp_asn1_enc_raw(pbuf_stream, (const u8_t *)&ip_2_ip4(&trap->sip)->addr, sizeof(ip_2_ip4(&trap->sip)->addr));
+#endif
+  }
+
+  /* trap length */
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_INTEGER, 0, 0);
+  snmp_asn1_enc_s32t_cnt(trap->gen_trap, &tlv.value_len);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+  snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->gen_trap);
+
+  /* specific trap */
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_INTEGER, 0, 0);
+  snmp_asn1_enc_s32t_cnt(trap->spc_trap, &tlv.value_len);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+  snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->spc_trap);
+
+  /* timestamp */
+  SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_TIMETICKS, 0, 0);
+  snmp_asn1_enc_s32t_cnt(trap->ts, &tlv.value_len);
+  snmp_ans1_enc_tlv(pbuf_stream, &tlv);
+  snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->ts);
+}
+
+#endif /* LWIP_SNMP */

ext/lwip/src/apps/snmp/snmpv3.c

@@ -0,0 +1,136 @@
+/**
+ * @file
+ * Additional SNMPv3 functionality RFC3414 and RFC3826.
+ */
+
+/*
+ * Copyright (c) 2016 Elias Oenal.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Elias Oenal <lwip@eliasoenal.com>
+ */
+
+#include "snmpv3_priv.h"
+#include "lwip/apps/snmpv3.h"
+#include "lwip/sys.h"
+#include <string.h>
+
+#if LWIP_SNMP && LWIP_SNMP_V3
+
+#ifdef LWIP_SNMPV3_INCLUDE_ENGINE
+#include LWIP_SNMPV3_INCLUDE_ENGINE
+#endif
+
+#define SNMP_MAX_TIME_BOOT 2147483647UL
+
+/** Call this if engine has been changed. Has to reset boots, see below */
+void
+snmpv3_engine_id_changed(void)
+{
+  snmpv3_set_engine_boots(0);
+}
+
+/** According to RFC3414 2.2.2.
+ *
+ * The number of times that the SNMP engine has
+ * (re-)initialized itself since snmpEngineID
+ * was last configured.
+ */
+u32_t
+snmpv3_get_engine_boots_internal(void)
+{
+  if (snmpv3_get_engine_boots() == 0 ||
+      snmpv3_get_engine_boots() < SNMP_MAX_TIME_BOOT) {
+    return snmpv3_get_engine_boots();
+  }
+
+  snmpv3_set_engine_boots(SNMP_MAX_TIME_BOOT);
+  return snmpv3_get_engine_boots();
+}
+
+/** RFC3414 2.2.2.
+ *
+ * Once the timer reaches 2147483647 it gets reset to zero and the
+ * engine boot ups get incremented.
+ */
+u32_t
+snmpv3_get_engine_time_internal(void)
+{
+  if (snmpv3_get_engine_time() >= SNMP_MAX_TIME_BOOT) {
+    snmpv3_reset_engine_time();
+
+    if (snmpv3_get_engine_boots() < SNMP_MAX_TIME_BOOT - 1) {
+      snmpv3_set_engine_boots(snmpv3_get_engine_boots() + 1);
+    } else {
+      snmpv3_set_engine_boots(SNMP_MAX_TIME_BOOT);
+    }
+  }
+
+  return snmpv3_get_engine_time();
+}
+
+#if LWIP_SNMP_V3_CRYPTO
+
+/* This function ignores the byte order suggestion in RFC3414
+ * since it simply doesn't influence the effectiveness of an IV.
+ *
+ * Implementing RFC3826 priv param algorithm if LWIP_RAND is available.
+ *
+ * @todo: This is a potential thread safety issue.
+ */
+err_t
+snmpv3_build_priv_param(u8_t* priv_param)
+{
+#ifdef LWIP_RAND /* Based on RFC3826 */
+  static u8_t init;
+  static u32_t priv1, priv2;
+
+  /* Lazy initialisation */
+  if (init == 0) {
+    init = 1;
+    priv1 = LWIP_RAND();
+    priv2 = LWIP_RAND();
+  }
+
+  memcpy(&priv_param[0], &priv1, sizeof(priv1));
+  memcpy(&priv_param[4], &priv2, sizeof(priv2));
+
+  /* Emulate 64bit increment */
+  priv1++;
+  if (!priv1) { /* Overflow */
+    priv2++;
+  }
+#else /* Based on RFC3414 */
+  static u32_t ctr;
+  u32_t boots = LWIP_SNMPV3_GET_ENGINE_BOOTS();
+  memcpy(&priv_param[0], &boots, 4);
+  memcpy(&priv_param[4], &ctr, 4);
+  ctr++;
+#endif
+  return ERR_OK;
+}
+#endif /* LWIP_SNMP_V3_CRYPTO */
+
+#endif

ext/lwip/src/apps/snmp/snmpv3_dummy.c

@@ -0,0 +1,145 @@
+/**
+ * @file
+ * Dummy SNMPv3 functions.
+ */
+
+/*
+ * Copyright (c) 2016 Elias Oenal.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Elias Oenal <lwip@eliasoenal.com>
+ *         Dirk Ziegelmeier <dirk@ziegelmeier.net>
+ */
+
+#include "lwip/apps/snmpv3.h"
+#include "snmpv3_priv.h"
+#include <string.h>
+#include "lwip/err.h"
+
+#if LWIP_SNMP && LWIP_SNMP_V3
+
+/**
+ *  @param username is a pointer to a string.
+ * @param auth_algo is a pointer to u8_t. The implementation has to set this if user was found.
+ * @param auth_key is a pointer to a pointer to a string. Implementation has to set this if user was found.
+ * @param priv_algo is a pointer to u8_t. The implementation has to set this if user was found.
+ * @param priv_key is a pointer to a pointer to a string. Implementation has to set this if user was found.
+ */
+err_t
+snmpv3_get_user(const char* username, u8_t *auth_algo, u8_t *auth_key, u8_t *priv_algo, u8_t *priv_key)
+{
+  const char* engine_id;
+  u8_t engine_id_len;
+  
+  if(strlen(username) == 0) {
+    return ERR_OK;
+  }
+  
+  if(memcmp(username, "lwip", 4) != 0) {
+    return ERR_VAL;
+  }
+  
+  snmpv3_get_engine_id(&engine_id, &engine_id_len);
+  
+  if(auth_key != NULL) {
+    snmpv3_password_to_key_sha((const u8_t*)"maplesyrup", 10,
+      (const u8_t*)engine_id, engine_id_len,
+      auth_key);
+    *auth_algo = SNMP_V3_AUTH_ALGO_SHA;
+  }
+  if(priv_key != NULL) {
+    snmpv3_password_to_key_sha((const u8_t*)"maplesyrup", 10,
+      (const u8_t*)engine_id, engine_id_len,
+      priv_key);
+    *priv_algo = SNMP_V3_PRIV_ALGO_DES;
+  }
+  return ERR_OK;
+}
+
+/**
+ * Get engine ID from persistence
+ * @param id
+ * @param len
+ */
+void
+snmpv3_get_engine_id(const char **id, u8_t *len)
+{
+  *id = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02";
+  *len = 12;
+}
+
+/**
+ * Store engine ID in persistence
+ * @param id
+ * @param len
+ */
+err_t
+snmpv3_set_engine_id(const char *id, u8_t len)
+{
+  LWIP_UNUSED_ARG(id);
+  LWIP_UNUSED_ARG(len);
+  return ERR_OK;
+}
+
+/**
+ * Get engine boots from persistence. Must be increased on each boot.
+ * @return 
+ */
+u32_t
+snmpv3_get_engine_boots(void)
+{
+  return 0;
+}
+
+/**
+ * Store engine boots in persistence
+ * @param boots
+ */
+void 
+snmpv3_set_engine_boots(u32_t boots)
+{
+  LWIP_UNUSED_ARG(boots);
+}
+
+/**
+ * RFC3414 2.2.2.
+ * Once the timer reaches 2147483647 it gets reset to zero and the
+ * engine boot ups get incremented.
+ */
+u32_t
+snmpv3_get_engine_time(void)
+{
+  return 0;
+}
+
+/**
+ * Reset current engine time to 0
+ */
+void
+snmpv3_reset_engine_time(void)
+{
+}
+
+#endif /* LWIP_SNMP && LWIP_SNMP_V3 */

ext/lwip/src/apps/snmp/snmpv3_mbedtls.c

@@ -0,0 +1,331 @@
+/**
+ * @file
+ * SNMPv3 crypto/auth functions implemented for ARM mbedtls.
+ */
+
+/*
+ * Copyright (c) 2016 Elias Oenal and Dirk Ziegelmeier.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Elias Oenal <lwip@eliasoenal.com>
+ *         Dirk Ziegelmeier <dirk@ziegelmeier.net>
+ */
+
+#include "lwip/apps/snmpv3.h"
+#include "snmpv3_priv.h"
+#include "lwip/arch.h"
+#include "snmp_msg.h"
+#include "lwip/sys.h"
+#include <string.h>
+
+#if LWIP_SNMP && LWIP_SNMP_V3 && LWIP_SNMP_V3_MBEDTLS
+
+#include "mbedtls/md.h"
+#include "mbedtls/cipher.h"
+
+#include "mbedtls/md5.h"
+#include "mbedtls/sha1.h"
+
+err_t
+snmpv3_auth(struct snmp_pbuf_stream* stream, u16_t length,
+    const u8_t* key, u8_t algo, u8_t* hmac_out)
+{
+  u32_t i;
+  u8_t key_len;
+  const mbedtls_md_info_t *md_info;
+  mbedtls_md_context_t ctx;
+  struct snmp_pbuf_stream read_stream;
+  snmp_pbuf_stream_init(&read_stream, stream->pbuf, stream->offset, stream->length);
+
+  if (algo == SNMP_V3_AUTH_ALGO_MD5) {
+    md_info = mbedtls_md_info_from_type(MBEDTLS_MD_MD5);
+    key_len = SNMP_V3_MD5_LEN;
+  } else if (algo == SNMP_V3_AUTH_ALGO_SHA) {
+    md_info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA1);
+    key_len = SNMP_V3_SHA_LEN;
+  } else {
+    return ERR_ARG;
+  }
+
+  mbedtls_md_init(&ctx);
+  if(mbedtls_md_setup(&ctx, md_info, 1) != 0) {
+    return ERR_ARG;
+  }
+          
+  if (mbedtls_md_hmac_starts(&ctx, key, key_len) != 0) {
+    goto free_md;
+  }
+
+  for (i = 0; i < length; i++) {
+    u8_t byte;
+
+    if (snmp_pbuf_stream_read(&read_stream, &byte)) {
+      goto free_md;
+    }
+
+    if (mbedtls_md_hmac_update(&ctx, &byte, 1) != 0) {
+      goto free_md;
+    }
+  }
+
+  if (mbedtls_md_hmac_finish(&ctx, hmac_out) != 0) {
+    goto free_md;
+  }
+
+  mbedtls_md_free(&ctx);
+  return ERR_OK;
+  
+free_md:
+  mbedtls_md_free(&ctx);
+  return ERR_ARG;
+}
+
+#if LWIP_SNMP_V3_CRYPTO
+
+err_t
+snmpv3_crypt(struct snmp_pbuf_stream* stream, u16_t length,
+    const u8_t* key, const u8_t* priv_param, const u32_t engine_boots,
+    const u32_t engine_time, u8_t algo, u8_t mode)
+{
+  size_t i;
+  mbedtls_cipher_context_t ctx;
+  const mbedtls_cipher_info_t *cipher_info;
+
+  struct snmp_pbuf_stream read_stream;
+  struct snmp_pbuf_stream write_stream;
+  snmp_pbuf_stream_init(&read_stream, stream->pbuf, stream->offset, stream->length);
+  snmp_pbuf_stream_init(&write_stream, stream->pbuf, stream->offset, stream->length);
+  mbedtls_cipher_init(&ctx);
+
+  if (algo == SNMP_V3_PRIV_ALGO_DES) {
+    u8_t iv_local[8];
+    u8_t out_bytes[8];
+    size_t out_len;
+
+    /* RFC 3414 mandates padding for DES */
+    if ((length & 0x07) != 0) {
+      return ERR_ARG;
+    }
+
+    cipher_info = mbedtls_cipher_info_from_type(MBEDTLS_CIPHER_DES_CBC);
+    if(mbedtls_cipher_setup(&ctx, cipher_info) != 0) {
+      return ERR_ARG;
+    }
+    if(mbedtls_cipher_set_padding_mode(&ctx, MBEDTLS_PADDING_NONE) != 0) {
+      return ERR_ARG;
+    }
+    if(mbedtls_cipher_setkey(&ctx, key, 8*8, (mode == SNMP_V3_PRIV_MODE_ENCRYPT)? MBEDTLS_ENCRYPT : MBEDTLS_DECRYPT) != 0) {
+      goto error;
+    }
+
+    /* Prepare IV */    
+    for (i = 0; i < LWIP_ARRAYSIZE(iv_local); i++) {
+      iv_local[i] = priv_param[i] ^ key[i + 8];
+    }
+    if(mbedtls_cipher_set_iv(&ctx, iv_local, LWIP_ARRAYSIZE(iv_local)) != 0) {
+      goto error;
+    }
+
+    for (i = 0; i < length; i += 8) {
+      size_t j;
+      u8_t in_bytes[8];
+      out_len = LWIP_ARRAYSIZE(out_bytes) ;
+      
+      for (j = 0; j < LWIP_ARRAYSIZE(in_bytes); j++) {
+        snmp_pbuf_stream_read(&read_stream, &in_bytes[j]);
+      }
+
+      if(mbedtls_cipher_update(&ctx, in_bytes, LWIP_ARRAYSIZE(in_bytes), out_bytes, &out_len) != 0) {
+        goto error;
+      }
+
+      snmp_pbuf_stream_writebuf(&write_stream, out_bytes, out_len);
+    }
+    
+    out_len = LWIP_ARRAYSIZE(out_bytes);
+    if(mbedtls_cipher_finish(&ctx, out_bytes, &out_len) != 0) {
+      goto error;
+    }
+    snmp_pbuf_stream_writebuf(&write_stream, out_bytes, out_len);
+  } else if (algo == SNMP_V3_PRIV_ALGO_AES) {
+    u8_t iv_local[16];
+
+    cipher_info = mbedtls_cipher_info_from_type(MBEDTLS_CIPHER_AES_128_CFB128);
+    if(mbedtls_cipher_setup(&ctx, cipher_info) != 0) {
+      return ERR_ARG;
+    }
+    if(mbedtls_cipher_setkey(&ctx, key, 16*8, (mode == SNMP_V3_PRIV_MODE_ENCRYPT)? MBEDTLS_ENCRYPT : MBEDTLS_DECRYPT) != 0) {
+      goto error;
+    }
+
+    /*
+     * IV is the big endian concatenation of boots,
+     * uptime and priv param - see RFC3826.
+     */
+    iv_local[0 + 0] = (engine_boots >> 24) & 0xFF;
+    iv_local[0 + 1] = (engine_boots >> 16) & 0xFF;
+    iv_local[0 + 2] = (engine_boots >>  8) & 0xFF;
+    iv_local[0 + 3] = (engine_boots >>  0) & 0xFF;
+    iv_local[4 + 0] = (engine_time  >> 24) & 0xFF;
+    iv_local[4 + 1] = (engine_time  >> 16) & 0xFF;
+    iv_local[4 + 2] = (engine_time  >>  8) & 0xFF;
+    iv_local[4 + 3] = (engine_time  >>  0) & 0xFF;
+    memcpy(iv_local + 8, priv_param, 8);
+    if(mbedtls_cipher_set_iv(&ctx, iv_local, LWIP_ARRAYSIZE(iv_local)) != 0) {
+      goto error;
+    }
+
+    for (i = 0; i < length; i++) {
+      u8_t in_byte;
+      u8_t out_byte;
+      size_t out_len = sizeof(out_byte);
+      
+      snmp_pbuf_stream_read(&read_stream, &in_byte);
+      if(mbedtls_cipher_update(&ctx, &in_byte, sizeof(in_byte), &out_byte, &out_len) != 0) {
+        goto error;
+      }
+      snmp_pbuf_stream_write(&write_stream, out_byte);
+    }
+  } else {
+    return ERR_ARG;
+  }
+
+  mbedtls_cipher_free(&ctx);
+  return ERR_OK;
+
+error:
+  mbedtls_cipher_free(&ctx);
+  return ERR_OK;
+}
+
+#endif /* LWIP_SNMP_V3_CRYPTO */
+
+/* A.2.1. Password to Key Sample Code for MD5 */
+void 
+snmpv3_password_to_key_md5(
+    const u8_t *password,    /* IN */
+    u8_t        passwordlen, /* IN */
+    const u8_t *engineID,    /* IN  - pointer to snmpEngineID  */
+    u8_t        engineLength,/* IN  - length of snmpEngineID */
+    u8_t       *key)         /* OUT - pointer to caller 16-octet buffer */
+{
+  mbedtls_md5_context MD;
+  u8_t *cp, password_buf[64];
+  u32_t password_index = 0;
+  u8_t i;
+  u32_t count = 0;
+
+  mbedtls_md5_init(&MD); /* initialize MD5 */
+  mbedtls_md5_starts(&MD);
+
+  /**********************************************/
+  /* Use while loop until we've done 1 Megabyte */
+  /**********************************************/
+  while (count < 1048576) {
+    cp = password_buf;
+    for (i = 0; i < 64; i++) {
+      /*************************************************/
+      /* Take the next octet of the password, wrapping */
+      /* to the beginning of the password as necessary.*/
+      /*************************************************/
+      *cp++ = password[password_index++ % passwordlen];
+    }
+    mbedtls_md5_update(&MD, password_buf, 64);
+    count += 64;
+  }
+  mbedtls_md5_finish(&MD, key); /* tell MD5 we're done */
+
+  /*****************************************************/
+  /* Now localize the key with the engineID and pass   */
+  /* through MD5 to produce final key                  */
+  /* May want to ensure that engineLength <= 32,       */
+  /* otherwise need to use a buffer larger than 64     */
+  /*****************************************************/
+  memcpy(password_buf, key, 16);
+  memcpy(password_buf + 16, engineID, engineLength);
+  memcpy(password_buf + 16 + engineLength, key, 16);
+
+  mbedtls_md5_starts(&MD);
+  mbedtls_md5_update(&MD, password_buf, 32 + engineLength);
+  mbedtls_md5_finish(&MD, key);
+
+  mbedtls_md5_free(&MD);
+  return;
+}
+
+/* A.2.2. Password to Key Sample Code for SHA */
+void 
+snmpv3_password_to_key_sha(
+    const u8_t *password,    /* IN */
+    u8_t        passwordlen, /* IN */
+    const u8_t *engineID,    /* IN  - pointer to snmpEngineID  */
+    u8_t        engineLength,/* IN  - length of snmpEngineID */
+    u8_t       *key)         /* OUT - pointer to caller 20-octet buffer */
+{
+  mbedtls_sha1_context SH;
+  u8_t *cp, password_buf[72];
+  u32_t password_index = 0;
+  u8_t i;
+  u32_t count = 0;
+
+  mbedtls_sha1_init(&SH); /* initialize SHA */
+  mbedtls_sha1_starts(&SH);
+
+  /**********************************************/
+  /* Use while loop until we've done 1 Megabyte */
+  /**********************************************/
+  while (count < 1048576) {
+    cp = password_buf;
+    for (i = 0; i < 64; i++) {
+      /*************************************************/
+      /* Take the next octet of the password, wrapping */
+      /* to the beginning of the password as necessary.*/
+      /*************************************************/
+      *cp++ = password[password_index++ % passwordlen];
+    }
+    mbedtls_sha1_update(&SH, password_buf, 64);
+    count += 64;
+  }
+  mbedtls_sha1_finish(&SH, key); /* tell SHA we're done */
+
+  /*****************************************************/
+  /* Now localize the key with the engineID and pass   */
+  /* through SHA to produce final key                  */
+  /* May want to ensure that engineLength <= 32,       */
+  /* otherwise need to use a buffer larger than 72     */
+  /*****************************************************/
+  memcpy(password_buf, key, 20);
+  memcpy(password_buf + 20, engineID, engineLength);
+  memcpy(password_buf + 20 + engineLength, key, 20);
+
+  mbedtls_sha1_starts(&SH);
+  mbedtls_sha1_update(&SH, password_buf, 40 + engineLength);
+  mbedtls_sha1_finish(&SH, key);
+  
+  mbedtls_sha1_free(&SH);
+  return;
+}
+
+#endif /* LWIP_SNMP && LWIP_SNMP_V3 && LWIP_SNMP_V3_MBEDTLS */

ext/lwip/src/apps/snmp/snmpv3_priv.h

@@ -0,0 +1,66 @@
+/**
+ * @file
+ * Additional SNMPv3 functionality RFC3414 and RFC3826 (internal API, do not use in client code).
+ */
+
+/*
+ * Copyright (c) 2016 Elias Oenal.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Elias Oenal <lwip@eliasoenal.com>
+ */
+
+#ifndef LWIP_HDR_APPS_SNMP_V3_PRIV_H
+#define LWIP_HDR_APPS_SNMP_V3_PRIV_H
+
+#include "lwip/apps/snmp_opts.h"
+
+#if LWIP_SNMP && LWIP_SNMP_V3
+
+#include "snmp_pbuf_stream.h"
+
+/* According to RFC 3411 */
+#define SNMP_V3_MAX_ENGINE_ID_LENGTH  32
+#define SNMP_V3_MAX_USER_LENGTH       32
+
+#define SNMP_V3_MAX_AUTH_PARAM_LENGTH  12
+#define SNMP_V3_MAX_PRIV_PARAM_LENGTH  8
+
+#define SNMP_V3_AUTH_FLAG      0x01
+#define SNMP_V3_PRIV_FLAG      0x02
+
+#define SNMP_V3_MD5_LEN        16
+#define SNMP_V3_SHA_LEN        20
+
+u32_t snmpv3_get_engine_boots_internal(void);
+u32_t snmpv3_get_engine_time_internal(void);
+err_t snmpv3_auth(struct snmp_pbuf_stream* stream, u16_t length, const u8_t* key, u8_t algo, u8_t* hmac_out);
+err_t snmpv3_crypt(struct snmp_pbuf_stream* stream, u16_t length, const u8_t* key,
+    const u8_t* priv_param, const u32_t engine_boots, const u32_t engine_time, u8_t algo, u8_t mode);
+err_t snmpv3_build_priv_param(u8_t* priv_param);
+
+#endif
+
+#endif /* LWIP_HDR_APPS_SNMP_V3_PRIV_H */

ext/lwip/src/apps/sntp/sntp.c

@@ -0,0 +1,726 @@
+/**
+ * @file
+ * SNTP client module
+ */
+
+/*
+ * Copyright (c) 2007-2009 Frédéric Bernon, Simon Goldschmidt
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Frédéric Bernon, Simon Goldschmidt
+ */
+
+
+/**
+ * @defgroup sntp SNTP
+ * @ingroup apps
+ *
+ * This is simple "SNTP" client for the lwIP raw API.
+ * It is a minimal implementation of SNTPv4 as specified in RFC 4330.
+ *
+ * For a list of some public NTP servers, see this link :
+ * http://support.ntp.org/bin/view/Servers/NTPPoolServers
+ *
+ * @todo:
+ * - set/change servers at runtime
+ * - complete SNTP_CHECK_RESPONSE checks 3 and 4
+ */
+
+#include "lwip/apps/sntp.h"
+
+#include "lwip/opt.h"
+#include "lwip/timeouts.h"
+#include "lwip/udp.h"
+#include "lwip/dns.h"
+#include "lwip/ip_addr.h"
+#include "lwip/pbuf.h"
+#include "lwip/dhcp.h"
+
+#include <string.h>
+#include <time.h>
+
+#if LWIP_UDP
+
+/* Handle support for more than one server via SNTP_MAX_SERVERS */
+#if SNTP_MAX_SERVERS > 1
+#define SNTP_SUPPORT_MULTIPLE_SERVERS 1
+#else /* NTP_MAX_SERVERS > 1 */
+#define SNTP_SUPPORT_MULTIPLE_SERVERS 0
+#endif /* NTP_MAX_SERVERS > 1 */
+
+#if (SNTP_UPDATE_DELAY < 15000) && !defined(SNTP_SUPPRESS_DELAY_CHECK)
+#error "SNTPv4 RFC 4330 enforces a minimum update time of 15 seconds (define SNTP_SUPPRESS_DELAY_CHECK to disable this error)!"
+#endif
+
+/* Configure behaviour depending on microsecond or second precision */
+#ifdef SNTP_SET_SYSTEM_TIME_US
+#define SNTP_CALC_TIME_US           1
+#define SNTP_RECEIVE_TIME_SIZE      2
+#else
+#define SNTP_SET_SYSTEM_TIME_US(sec, us)
+#define SNTP_CALC_TIME_US           0
+#define SNTP_RECEIVE_TIME_SIZE      1
+#endif
+
+
+/* the various debug levels for this file */
+#define SNTP_DEBUG_TRACE        (SNTP_DEBUG | LWIP_DBG_TRACE)
+#define SNTP_DEBUG_STATE        (SNTP_DEBUG | LWIP_DBG_STATE)
+#define SNTP_DEBUG_WARN         (SNTP_DEBUG | LWIP_DBG_LEVEL_WARNING)
+#define SNTP_DEBUG_WARN_STATE   (SNTP_DEBUG | LWIP_DBG_LEVEL_WARNING | LWIP_DBG_STATE)
+#define SNTP_DEBUG_SERIOUS      (SNTP_DEBUG | LWIP_DBG_LEVEL_SERIOUS)
+
+#define SNTP_ERR_KOD                1
+
+/* SNTP protocol defines */
+#define SNTP_MSG_LEN                48
+
+#define SNTP_OFFSET_LI_VN_MODE      0
+#define SNTP_LI_MASK                0xC0
+#define SNTP_LI_NO_WARNING          0x00
+#define SNTP_LI_LAST_MINUTE_61_SEC  0x01
+#define SNTP_LI_LAST_MINUTE_59_SEC  0x02
+#define SNTP_LI_ALARM_CONDITION     0x03 /* (clock not synchronized) */
+
+#define SNTP_VERSION_MASK           0x38
+#define SNTP_VERSION                (4/* NTP Version 4*/<<3)
+
+#define SNTP_MODE_MASK              0x07
+#define SNTP_MODE_CLIENT            0x03
+#define SNTP_MODE_SERVER            0x04
+#define SNTP_MODE_BROADCAST         0x05
+
+#define SNTP_OFFSET_STRATUM         1
+#define SNTP_STRATUM_KOD            0x00
+
+#define SNTP_OFFSET_ORIGINATE_TIME  24
+#define SNTP_OFFSET_RECEIVE_TIME    32
+#define SNTP_OFFSET_TRANSMIT_TIME   40
+
+/* number of seconds between 1900 and 1970 (MSB=1)*/
+#define DIFF_SEC_1900_1970         (2208988800UL)
+/* number of seconds between 1970 and Feb 7, 2036 (6:28:16 UTC) (MSB=0) */
+#define DIFF_SEC_1970_2036         (2085978496UL)
+
+/**
+ * SNTP packet format (without optional fields)
+ * Timestamps are coded as 64 bits:
+ * - 32 bits seconds since Jan 01, 1970, 00:00
+ * - 32 bits seconds fraction (0-padded)
+ * For future use, if the MSB in the seconds part is set, seconds are based
+ * on Feb 07, 2036, 06:28:16.
+ */
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct sntp_msg {
+  PACK_STRUCT_FLD_8(u8_t  li_vn_mode);
+  PACK_STRUCT_FLD_8(u8_t  stratum);
+  PACK_STRUCT_FLD_8(u8_t  poll);
+  PACK_STRUCT_FLD_8(u8_t  precision);
+  PACK_STRUCT_FIELD(u32_t root_delay);
+  PACK_STRUCT_FIELD(u32_t root_dispersion);
+  PACK_STRUCT_FIELD(u32_t reference_identifier);
+  PACK_STRUCT_FIELD(u32_t reference_timestamp[2]);
+  PACK_STRUCT_FIELD(u32_t originate_timestamp[2]);
+  PACK_STRUCT_FIELD(u32_t receive_timestamp[2]);
+  PACK_STRUCT_FIELD(u32_t transmit_timestamp[2]);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+
+/* function prototypes */
+static void sntp_request(void *arg);
+
+/** The operating mode */
+static u8_t sntp_opmode;
+
+/** The UDP pcb used by the SNTP client */
+static struct udp_pcb* sntp_pcb;
+/** Names/Addresses of servers */
+struct sntp_server {
+#if SNTP_SERVER_DNS
+  char* name;
+#endif /* SNTP_SERVER_DNS */
+  ip_addr_t addr;
+};
+static struct sntp_server sntp_servers[SNTP_MAX_SERVERS];
+
+#if SNTP_GET_SERVERS_FROM_DHCP
+static u8_t sntp_set_servers_from_dhcp;
+#endif /* SNTP_GET_SERVERS_FROM_DHCP */
+#if SNTP_SUPPORT_MULTIPLE_SERVERS
+/** The currently used server (initialized to 0) */
+static u8_t sntp_current_server;
+#else /* SNTP_SUPPORT_MULTIPLE_SERVERS */
+#define sntp_current_server 0
+#endif /* SNTP_SUPPORT_MULTIPLE_SERVERS */
+
+#if SNTP_RETRY_TIMEOUT_EXP
+#define SNTP_RESET_RETRY_TIMEOUT() sntp_retry_timeout = SNTP_RETRY_TIMEOUT
+/** Retry time, initialized with SNTP_RETRY_TIMEOUT and doubled with each retry. */
+static u32_t sntp_retry_timeout;
+#else /* SNTP_RETRY_TIMEOUT_EXP */
+#define SNTP_RESET_RETRY_TIMEOUT()
+#define sntp_retry_timeout SNTP_RETRY_TIMEOUT
+#endif /* SNTP_RETRY_TIMEOUT_EXP */
+
+#if SNTP_CHECK_RESPONSE >= 1
+/** Saves the last server address to compare with response */
+static ip_addr_t sntp_last_server_address;
+#endif /* SNTP_CHECK_RESPONSE >= 1 */
+
+#if SNTP_CHECK_RESPONSE >= 2
+/** Saves the last timestamp sent (which is sent back by the server)
+ * to compare against in response */
+static u32_t sntp_last_timestamp_sent[2];
+#endif /* SNTP_CHECK_RESPONSE >= 2 */
+
+/**
+ * SNTP processing of received timestamp
+ */
+static void
+sntp_process(u32_t *receive_timestamp)
+{
+  /* convert SNTP time (1900-based) to unix GMT time (1970-based)
+   * if MSB is 0, SNTP time is 2036-based!
+   */
+  u32_t rx_secs = ntohl(receive_timestamp[0]);
+  int is_1900_based = ((rx_secs & 0x80000000) != 0);
+  u32_t t = is_1900_based ? (rx_secs - DIFF_SEC_1900_1970) : (rx_secs + DIFF_SEC_1970_2036);
+  time_t tim = t;
+
+#if SNTP_CALC_TIME_US
+  u32_t us = ntohl(receive_timestamp[1]) / 4295;
+  SNTP_SET_SYSTEM_TIME_US(t, us);
+  /* display local time from GMT time */
+  LWIP_DEBUGF(SNTP_DEBUG_TRACE, ("sntp_process: %s, %"U32_F" us", ctime(&tim), us));
+
+#else /* SNTP_CALC_TIME_US */
+
+  /* change system time and/or the update the RTC clock */
+  SNTP_SET_SYSTEM_TIME(t);
+  /* display local time from GMT time */
+  LWIP_DEBUGF(SNTP_DEBUG_TRACE, ("sntp_process: %s", ctime(&tim)));
+#endif /* SNTP_CALC_TIME_US */
+  LWIP_UNUSED_ARG(tim);
+}
+
+/**
+ * Initialize request struct to be sent to server.
+ */
+static void
+sntp_initialize_request(struct sntp_msg *req)
+{
+  memset(req, 0, SNTP_MSG_LEN);
+  req->li_vn_mode = SNTP_LI_NO_WARNING | SNTP_VERSION | SNTP_MODE_CLIENT;
+
+#if SNTP_CHECK_RESPONSE >= 2
+  {
+    u32_t sntp_time_sec, sntp_time_us;
+    /* fill in transmit timestamp and save it in 'sntp_last_timestamp_sent' */
+    SNTP_GET_SYSTEM_TIME(sntp_time_sec, sntp_time_us);
+    sntp_last_timestamp_sent[0] = htonl(sntp_time_sec + DIFF_SEC_1900_1970);
+    req->transmit_timestamp[0] = sntp_last_timestamp_sent[0];
+    /* we send/save us instead of fraction to be faster... */
+    sntp_last_timestamp_sent[1] = htonl(sntp_time_us);
+    req->transmit_timestamp[1] = sntp_last_timestamp_sent[1];
+  }
+#endif /* SNTP_CHECK_RESPONSE >= 2 */
+}
+
+/**
+ * Retry: send a new request (and increase retry timeout).
+ *
+ * @param arg is unused (only necessary to conform to sys_timeout)
+ */
+static void
+sntp_retry(void* arg)
+{
+  LWIP_UNUSED_ARG(arg);
+
+  LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_retry: Next request will be sent in %"U32_F" ms\n",
+    sntp_retry_timeout));
+
+  /* set up a timer to send a retry and increase the retry delay */
+  sys_timeout(sntp_retry_timeout, sntp_request, NULL);
+
+#if SNTP_RETRY_TIMEOUT_EXP
+  {
+    u32_t new_retry_timeout;
+    /* increase the timeout for next retry */
+    new_retry_timeout = sntp_retry_timeout << 1;
+    /* limit to maximum timeout and prevent overflow */
+    if ((new_retry_timeout <= SNTP_RETRY_TIMEOUT_MAX) &&
+        (new_retry_timeout > sntp_retry_timeout)) {
+      sntp_retry_timeout = new_retry_timeout;
+    }
+  }
+#endif /* SNTP_RETRY_TIMEOUT_EXP */
+}
+
+#if SNTP_SUPPORT_MULTIPLE_SERVERS
+/**
+ * If Kiss-of-Death is received (or another packet parsing error),
+ * try the next server or retry the current server and increase the retry
+ * timeout if only one server is available.
+ * (implicitly, SNTP_MAX_SERVERS > 1)
+ *
+ * @param arg is unused (only necessary to conform to sys_timeout)
+ */
+static void
+sntp_try_next_server(void* arg)
+{
+  u8_t old_server, i;
+  LWIP_UNUSED_ARG(arg);
+
+  old_server = sntp_current_server;
+  for (i = 0; i < SNTP_MAX_SERVERS - 1; i++) {
+    sntp_current_server++;
+    if (sntp_current_server >= SNTP_MAX_SERVERS) {
+      sntp_current_server = 0;
+    }
+    if (!ip_addr_isany(&sntp_servers[sntp_current_server].addr)
+#if SNTP_SERVER_DNS
+        || (sntp_servers[sntp_current_server].name != NULL)
+#endif
+        ) {
+      LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_try_next_server: Sending request to server %"U16_F"\n",
+        (u16_t)sntp_current_server));
+      /* new server: reset retry timeout */
+      SNTP_RESET_RETRY_TIMEOUT();
+      /* instantly send a request to the next server */
+      sntp_request(NULL);
+      return;
+    }
+  }
+  /* no other valid server found */
+  sntp_current_server = old_server;
+  sntp_retry(NULL);
+}
+#else /* SNTP_SUPPORT_MULTIPLE_SERVERS */
+/* Always retry on error if only one server is supported */
+#define sntp_try_next_server    sntp_retry
+#endif /* SNTP_SUPPORT_MULTIPLE_SERVERS */
+
+/** UDP recv callback for the sntp pcb */
+static void
+sntp_recv(void *arg, struct udp_pcb* pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port)
+{
+  u8_t mode;
+  u8_t stratum;
+  u32_t receive_timestamp[SNTP_RECEIVE_TIME_SIZE];
+  err_t err;
+
+  LWIP_UNUSED_ARG(arg);
+  LWIP_UNUSED_ARG(pcb);
+
+  /* packet received: stop retry timeout  */
+  sys_untimeout(sntp_try_next_server, NULL);
+  sys_untimeout(sntp_request, NULL);
+
+  err = ERR_ARG;
+#if SNTP_CHECK_RESPONSE >= 1
+  /* check server address and port */
+  if (((sntp_opmode != SNTP_OPMODE_POLL) || ip_addr_cmp(addr, &sntp_last_server_address)) &&
+    (port == SNTP_PORT))
+#else /* SNTP_CHECK_RESPONSE >= 1 */
+  LWIP_UNUSED_ARG(addr);
+  LWIP_UNUSED_ARG(port);
+#endif /* SNTP_CHECK_RESPONSE >= 1 */
+  {
+    /* process the response */
+    if (p->tot_len == SNTP_MSG_LEN) {
+      pbuf_copy_partial(p, &mode, 1, SNTP_OFFSET_LI_VN_MODE);
+      mode &= SNTP_MODE_MASK;
+      /* if this is a SNTP response... */
+      if (((sntp_opmode == SNTP_OPMODE_POLL) && (mode == SNTP_MODE_SERVER)) ||
+          ((sntp_opmode == SNTP_OPMODE_LISTENONLY) && (mode == SNTP_MODE_BROADCAST))) {
+        pbuf_copy_partial(p, &stratum, 1, SNTP_OFFSET_STRATUM);
+        if (stratum == SNTP_STRATUM_KOD) {
+          /* Kiss-of-death packet. Use another server or increase UPDATE_DELAY. */
+          err = SNTP_ERR_KOD;
+          LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_recv: Received Kiss-of-Death\n"));
+        } else {
+#if SNTP_CHECK_RESPONSE >= 2
+          /* check originate_timetamp against sntp_last_timestamp_sent */
+          u32_t originate_timestamp[2];
+          pbuf_copy_partial(p, &originate_timestamp, 8, SNTP_OFFSET_ORIGINATE_TIME);
+          if ((originate_timestamp[0] != sntp_last_timestamp_sent[0]) ||
+              (originate_timestamp[1] != sntp_last_timestamp_sent[1]))
+          {
+            LWIP_DEBUGF(SNTP_DEBUG_WARN, ("sntp_recv: Invalid originate timestamp in response\n"));
+          } else
+#endif /* SNTP_CHECK_RESPONSE >= 2 */
+          /* @todo: add code for SNTP_CHECK_RESPONSE >= 3 and >= 4 here */
+          {
+            /* correct answer */
+            err = ERR_OK;
+            pbuf_copy_partial(p, &receive_timestamp, SNTP_RECEIVE_TIME_SIZE * 4, SNTP_OFFSET_TRANSMIT_TIME);
+          }
+        }
+      } else {
+        LWIP_DEBUGF(SNTP_DEBUG_WARN, ("sntp_recv: Invalid mode in response: %"U16_F"\n", (u16_t)mode));
+        /* wait for correct response */
+        err = ERR_TIMEOUT;
+      }
+    } else {
+      LWIP_DEBUGF(SNTP_DEBUG_WARN, ("sntp_recv: Invalid packet length: %"U16_F"\n", p->tot_len));
+    }
+  }
+#if SNTP_CHECK_RESPONSE >= 1
+  else {
+    /* packet from wrong remote address or port, wait for correct response */
+    err = ERR_TIMEOUT;
+  }
+#endif /* SNTP_CHECK_RESPONSE >= 1 */
+  pbuf_free(p);
+  if (err == ERR_OK) {
+    sntp_process(receive_timestamp);
+
+    /* Set up timeout for next request (only if poll response was received)*/
+    if (sntp_opmode == SNTP_OPMODE_POLL) {
+      /* Correct response, reset retry timeout */
+      SNTP_RESET_RETRY_TIMEOUT();
+
+      sys_timeout((u32_t)SNTP_UPDATE_DELAY, sntp_request, NULL);
+      LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_recv: Scheduled next time request: %"U32_F" ms\n",
+        (u32_t)SNTP_UPDATE_DELAY));
+    }
+  } else if (err != ERR_TIMEOUT) {
+    /* Errors are only processed in case of an explicit poll response */
+    if (sntp_opmode == SNTP_OPMODE_POLL) {
+      if (err == SNTP_ERR_KOD) {
+        /* Kiss-of-death packet. Use another server or increase UPDATE_DELAY. */
+        sntp_try_next_server(NULL);
+      } else {
+        /* another error, try the same server again */
+        sntp_retry(NULL);
+      }
+    }
+  }
+}
+
+/** Actually send an sntp request to a server.
+ *
+ * @param server_addr resolved IP address of the SNTP server
+ */
+static void
+sntp_send_request(const ip_addr_t *server_addr)
+{
+  struct pbuf* p;
+  p = pbuf_alloc(PBUF_TRANSPORT, SNTP_MSG_LEN, PBUF_RAM);
+  if (p != NULL) {
+    struct sntp_msg *sntpmsg = (struct sntp_msg *)p->payload;
+    LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_send_request: Sending request to server\n"));
+    /* initialize request message */
+    sntp_initialize_request(sntpmsg);
+    /* send request */
+    udp_sendto(sntp_pcb, p, server_addr, SNTP_PORT);
+    /* free the pbuf after sending it */
+    pbuf_free(p);
+    /* set up receive timeout: try next server or retry on timeout */
+    sys_timeout((u32_t)SNTP_RECV_TIMEOUT, sntp_try_next_server, NULL);
+#if SNTP_CHECK_RESPONSE >= 1
+    /* save server address to verify it in sntp_recv */
+    ip_addr_set(&sntp_last_server_address, server_addr);
+#endif /* SNTP_CHECK_RESPONSE >= 1 */
+  } else {
+    LWIP_DEBUGF(SNTP_DEBUG_SERIOUS, ("sntp_send_request: Out of memory, trying again in %"U32_F" ms\n",
+      (u32_t)SNTP_RETRY_TIMEOUT));
+    /* out of memory: set up a timer to send a retry */
+    sys_timeout((u32_t)SNTP_RETRY_TIMEOUT, sntp_request, NULL);
+  }
+}
+
+#if SNTP_SERVER_DNS
+/**
+ * DNS found callback when using DNS names as server address.
+ */
+static void
+sntp_dns_found(const char* hostname, const ip_addr_t *ipaddr, void *arg)
+{
+  LWIP_UNUSED_ARG(hostname);
+  LWIP_UNUSED_ARG(arg);
+
+  if (ipaddr != NULL) {
+    /* Address resolved, send request */
+    LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_dns_found: Server address resolved, sending request\n"));
+    sntp_send_request(ipaddr);
+  } else {
+    /* DNS resolving failed -> try another server */
+    LWIP_DEBUGF(SNTP_DEBUG_WARN_STATE, ("sntp_dns_found: Failed to resolve server address resolved, trying next server\n"));
+    sntp_try_next_server(NULL);
+  }
+}
+#endif /* SNTP_SERVER_DNS */
+
+/**
+ * Send out an sntp request.
+ *
+ * @param arg is unused (only necessary to conform to sys_timeout)
+ */
+static void
+sntp_request(void *arg)
+{
+  ip_addr_t sntp_server_address;
+  err_t err;
+
+  LWIP_UNUSED_ARG(arg);
+
+  /* initialize SNTP server address */
+#if SNTP_SERVER_DNS
+  if (sntp_servers[sntp_current_server].name) {
+    /* always resolve the name and rely on dns-internal caching & timeout */
+    ip_addr_set_zero(&sntp_servers[sntp_current_server].addr);
+    err = dns_gethostbyname(sntp_servers[sntp_current_server].name, &sntp_server_address,
+      sntp_dns_found, NULL);
+    if (err == ERR_INPROGRESS) {
+      /* DNS request sent, wait for sntp_dns_found being called */
+      LWIP_DEBUGF(SNTP_DEBUG_STATE, ("sntp_request: Waiting for server address to be resolved.\n"));
+      return;
+    } else if (err == ERR_OK) {
+      sntp_servers[sntp_current_server].addr = sntp_server_address;
+    }
+  } else
+#endif /* SNTP_SERVER_DNS */
+  {
+    sntp_server_address = sntp_servers[sntp_current_server].addr;
+    err = (ip_addr_isany_val(sntp_server_address)) ? ERR_ARG : ERR_OK;
+  }
+
+  if (err == ERR_OK) {
+    LWIP_DEBUGF(SNTP_DEBUG_TRACE, ("sntp_request: current server address is %s\n",
+      ipaddr_ntoa(&sntp_server_address)));
+    sntp_send_request(&sntp_server_address);
+  } else {
+    /* address conversion failed, try another server */
+    LWIP_DEBUGF(SNTP_DEBUG_WARN_STATE, ("sntp_request: Invalid server address, trying next server.\n"));
+    sys_timeout((u32_t)SNTP_RETRY_TIMEOUT, sntp_try_next_server, NULL);
+  }
+}
+
+/**
+ * @ingroup sntp
+ * Initialize this module.
+ * Send out request instantly or after SNTP_STARTUP_DELAY(_FUNC).
+ */
+void
+sntp_init(void)
+{
+#ifdef SNTP_SERVER_ADDRESS
+#if SNTP_SERVER_DNS
+  sntp_setservername(0, SNTP_SERVER_ADDRESS);
+#else
+#error SNTP_SERVER_ADDRESS string not supported SNTP_SERVER_DNS==0
+#endif
+#endif /* SNTP_SERVER_ADDRESS */
+
+  if (sntp_pcb == NULL) {
+    sntp_pcb = udp_new_ip_type(IPADDR_TYPE_ANY);
+    LWIP_ASSERT("Failed to allocate udp pcb for sntp client", sntp_pcb != NULL);
+    if (sntp_pcb != NULL) {
+      udp_recv(sntp_pcb, sntp_recv, NULL);
+
+      if (sntp_opmode == SNTP_OPMODE_POLL) {
+        SNTP_RESET_RETRY_TIMEOUT();
+#if SNTP_STARTUP_DELAY
+        sys_timeout((u32_t)SNTP_STARTUP_DELAY_FUNC, sntp_request, NULL);
+#else
+        sntp_request(NULL);
+#endif
+      } else if (sntp_opmode == SNTP_OPMODE_LISTENONLY) {
+        ip_set_option(sntp_pcb, SOF_BROADCAST);
+        udp_bind(sntp_pcb, IP_ANY_TYPE, SNTP_PORT);
+      }
+    }
+  }
+}
+
+/**
+ * @ingroup sntp
+ * Stop this module.
+ */
+void
+sntp_stop(void)
+{
+  if (sntp_pcb != NULL) {
+    sys_untimeout(sntp_request, NULL);
+    udp_remove(sntp_pcb);
+    sntp_pcb = NULL;
+  }
+}
+
+/**
+ * @ingroup sntp
+ * Get enabled state.
+ */
+u8_t sntp_enabled(void)
+{
+  return (sntp_pcb != NULL)? 1 : 0;
+}
+
+/**
+ * @ingroup sntp
+ * Sets the operating mode.
+ * @param operating_mode one of the available operating modes
+ */
+void
+sntp_setoperatingmode(u8_t operating_mode)
+{
+  LWIP_ASSERT("Invalid operating mode", operating_mode <= SNTP_OPMODE_LISTENONLY);
+  LWIP_ASSERT("Operating mode must not be set while SNTP client is running", sntp_pcb == NULL);
+  sntp_opmode = operating_mode;
+}
+
+/**
+ * @ingroup sntp
+ * Gets the operating mode.
+ */
+u8_t
+sntp_getoperatingmode(void)
+{
+  return sntp_opmode;
+}
+
+#if SNTP_GET_SERVERS_FROM_DHCP
+/**
+ * Config SNTP server handling by IP address, name, or DHCP; clear table
+ * @param set_servers_from_dhcp enable or disable getting server addresses from dhcp
+ */
+void
+sntp_servermode_dhcp(int set_servers_from_dhcp)
+{
+  u8_t new_mode = set_servers_from_dhcp ? 1 : 0;
+  if (sntp_set_servers_from_dhcp != new_mode) {
+    sntp_set_servers_from_dhcp = new_mode;
+  }
+}
+#endif /* SNTP_GET_SERVERS_FROM_DHCP */
+
+/**
+ * @ingroup sntp
+ * Initialize one of the NTP servers by IP address
+ *
+ * @param idx the index of the NTP server to set must be < SNTP_MAX_SERVERS
+ * @param server IP address of the NTP server to set
+ */
+void
+sntp_setserver(u8_t idx, const ip_addr_t *server)
+{
+  if (idx < SNTP_MAX_SERVERS) {
+    if (server != NULL) {
+      sntp_servers[idx].addr = (*server);
+    } else {
+      ip_addr_set_zero(&sntp_servers[idx].addr);
+    }
+#if SNTP_SERVER_DNS
+    sntp_servers[idx].name = NULL;
+#endif
+  }
+}
+
+#if LWIP_DHCP && SNTP_GET_SERVERS_FROM_DHCP
+/**
+ * Initialize one of the NTP servers by IP address, required by DHCP
+ *
+ * @param numdns the index of the NTP server to set must be < SNTP_MAX_SERVERS
+ * @param dnsserver IP address of the NTP server to set
+ */
+void
+dhcp_set_ntp_servers(u8_t num, const ip4_addr_t *server)
+{
+  LWIP_DEBUGF(SNTP_DEBUG_TRACE, ("sntp: %s %u.%u.%u.%u as NTP server #%u via DHCP\n",
+    (sntp_set_servers_from_dhcp ? "Got" : "Rejected"),
+    ip4_addr1(server), ip4_addr2(server), ip4_addr3(server), ip4_addr4(server), num));
+  if (sntp_set_servers_from_dhcp && num) {
+    u8_t i;
+    for (i = 0; (i < num) && (i < SNTP_MAX_SERVERS); i++) {
+      ip_addr_t addr;
+      ip_addr_copy_from_ip4(addr, server[i]);
+      sntp_setserver(i, &addr);
+    }
+    for (i = num; i < SNTP_MAX_SERVERS; i++) {
+      sntp_setserver(i, NULL);
+    }
+  }
+}
+#endif /* LWIP_DHCP && SNTP_GET_SERVERS_FROM_DHCP */
+
+/**
+ * @ingroup sntp
+ * Obtain one of the currently configured by IP address (or DHCP) NTP servers
+ *
+ * @param idx the index of the NTP server
+ * @return IP address of the indexed NTP server or "ip_addr_any" if the NTP
+ *         server has not been configured by address (or at all).
+ */
+const ip_addr_t*
+sntp_getserver(u8_t idx)
+{
+  if (idx < SNTP_MAX_SERVERS) {
+    return &sntp_servers[idx].addr;
+  }
+  return IP_ADDR_ANY;
+}
+
+#if SNTP_SERVER_DNS
+/**
+ * Initialize one of the NTP servers by name
+ *
+ * @param numdns the index of the NTP server to set must be < SNTP_MAX_SERVERS
+ * @param dnsserver DNS name of the NTP server to set, to be resolved at contact time
+ */
+void
+sntp_setservername(u8_t idx, char *server)
+{
+  if (idx < SNTP_MAX_SERVERS) {
+    sntp_servers[idx].name = server;
+  }
+}
+
+/**
+ * Obtain one of the currently configured by name NTP servers.
+ *
+ * @param numdns the index of the NTP server
+ * @return IP address of the indexed NTP server or NULL if the NTP
+ *         server has not been configured by name (or at all)
+ */
+char *
+sntp_getservername(u8_t idx)
+{
+  if (idx < SNTP_MAX_SERVERS) {
+    return sntp_servers[idx].name;
+  }
+  return NULL;
+}
+#endif /* SNTP_SERVER_DNS */
+
+#endif /* LWIP_UDP */

ext/lwip/src/core/def.c

@@ -0,0 +1,108 @@
+/**
+ * @file
+ * Common functions used throughout the stack.
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Simon Goldschmidt
+ *
+ */
+
+#include "lwip/opt.h"
+#include "lwip/def.h"
+
+/**
+ * These are reference implementations of the byte swapping functions.
+ * Again with the aim of being simple, correct and fully portable.
+ * Byte swapping is the second thing you would want to optimize. You will
+ * need to port it to your architecture and in your cc.h:
+ *
+ * #define LWIP_PLATFORM_BYTESWAP 1
+ * #define LWIP_PLATFORM_HTONS(x) <your_htons>
+ * #define LWIP_PLATFORM_HTONL(x) <your_htonl>
+ *
+ * Note ntohs() and ntohl() are merely references to the htonx counterparts.
+ */
+
+#if (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN)
+
+/**
+ * Convert an u16_t from host- to network byte order.
+ *
+ * @param n u16_t in host byte order
+ * @return n in network byte order
+ */
+u16_t
+lwip_htons(u16_t n)
+{
+  return ((n & 0xff) << 8) | ((n & 0xff00) >> 8);
+}
+
+/**
+ * Convert an u16_t from network- to host byte order.
+ *
+ * @param n u16_t in network byte order
+ * @return n in host byte order
+ */
+u16_t
+lwip_ntohs(u16_t n)
+{
+  return lwip_htons(n);
+}
+
+/**
+ * Convert an u32_t from host- to network byte order.
+ *
+ * @param n u32_t in host byte order
+ * @return n in network byte order
+ */
+u32_t
+lwip_htonl(u32_t n)
+{
+  return ((n & 0xff) << 24) |
+    ((n & 0xff00) << 8) |
+    ((n & 0xff0000UL) >> 8) |
+    ((n & 0xff000000UL) >> 24);
+}
+
+/**
+ * Convert an u32_t from network- to host byte order.
+ *
+ * @param n u32_t in network byte order
+ * @return n in host byte order
+ */
+u32_t
+lwip_ntohl(u32_t n)
+{
+  return lwip_htonl(n);
+}
+
+#endif /* (LWIP_PLATFORM_BYTESWAP == 0) && (BYTE_ORDER == LITTLE_ENDIAN) */

ext/lwip/src/core/inet_chksum.c

@@ -0,0 +1,612 @@
+/**
+ * @file
+ * Incluse internet checksum functions.
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/opt.h"
+
+#include "lwip/inet_chksum.h"
+#include "lwip/def.h"
+#include "lwip/ip_addr.h"
+
+#include <stddef.h>
+#include <string.h>
+
+/* These are some reference implementations of the checksum algorithm, with the
+ * aim of being simple, correct and fully portable. Checksumming is the
+ * first thing you would want to optimize for your platform. If you create
+ * your own version, link it in and in your cc.h put:
+ *
+ * #define LWIP_CHKSUM <your_checksum_routine>
+ *
+ * Or you can select from the implementations below by defining
+ * LWIP_CHKSUM_ALGORITHM to 1, 2 or 3.
+ */
+
+#ifndef LWIP_CHKSUM
+# define LWIP_CHKSUM lwip_standard_chksum
+# ifndef LWIP_CHKSUM_ALGORITHM
+#  define LWIP_CHKSUM_ALGORITHM 2
+# endif
+u16_t lwip_standard_chksum(const void *dataptr, int len);
+#endif
+/* If none set: */
+#ifndef LWIP_CHKSUM_ALGORITHM
+# define LWIP_CHKSUM_ALGORITHM 0
+#endif
+
+#if (LWIP_CHKSUM_ALGORITHM == 1) /* Version #1 */
+/**
+ * lwip checksum
+ *
+ * @param dataptr points to start of data to be summed at any boundary
+ * @param len length of data to be summed
+ * @return host order (!) lwip checksum (non-inverted Internet sum)
+ *
+ * @note accumulator size limits summable length to 64k
+ * @note host endianess is irrelevant (p3 RFC1071)
+ */
+u16_t
+lwip_standard_chksum(const void *dataptr, int len)
+{
+  u32_t acc;
+  u16_t src;
+  const u8_t *octetptr;
+
+  acc = 0;
+  /* dataptr may be at odd or even addresses */
+  octetptr = (const u8_t*)dataptr;
+  while (len > 1) {
+    /* declare first octet as most significant
+       thus assume network order, ignoring host order */
+    src = (*octetptr) << 8;
+    octetptr++;
+    /* declare second octet as least significant */
+    src |= (*octetptr);
+    octetptr++;
+    acc += src;
+    len -= 2;
+  }
+  if (len > 0) {
+    /* accumulate remaining octet */
+    src = (*octetptr) << 8;
+    acc += src;
+  }
+  /* add deferred carry bits */
+  acc = (acc >> 16) + (acc & 0x0000ffffUL);
+  if ((acc & 0xffff0000UL) != 0) {
+    acc = (acc >> 16) + (acc & 0x0000ffffUL);
+  }
+  /* This maybe a little confusing: reorder sum using htons()
+     instead of ntohs() since it has a little less call overhead.
+     The caller must invert bits for Internet sum ! */
+  return htons((u16_t)acc);
+}
+#endif
+
+#if (LWIP_CHKSUM_ALGORITHM == 2) /* Alternative version #2 */
+/*
+ * Curt McDowell
+ * Broadcom Corp.
+ * csm@broadcom.com
+ *
+ * IP checksum two bytes at a time with support for
+ * unaligned buffer.
+ * Works for len up to and including 0x20000.
+ * by Curt McDowell, Broadcom Corp. 12/08/2005
+ *
+ * @param dataptr points to start of data to be summed at any boundary
+ * @param len length of data to be summed
+ * @return host order (!) lwip checksum (non-inverted Internet sum)
+ */
+u16_t
+lwip_standard_chksum(const void *dataptr, int len)
+{
+  const u8_t *pb = (const u8_t *)dataptr;
+  const u16_t *ps;
+  u16_t t = 0;
+  u32_t sum = 0;
+  int odd = ((mem_ptr_t)pb & 1);
+
+  /* Get aligned to u16_t */
+  if (odd && len > 0) {
+    ((u8_t *)&t)[1] = *pb++;
+    len--;
+  }
+
+  /* Add the bulk of the data */
+  ps = (const u16_t *)(const void *)pb;
+  while (len > 1) {
+    sum += *ps++;
+    len -= 2;
+  }
+
+  /* Consume left-over byte, if any */
+  if (len > 0) {
+    ((u8_t *)&t)[0] = *(const u8_t *)ps;
+  }
+
+  /* Add end bytes */
+  sum += t;
+
+  /* Fold 32-bit sum to 16 bits
+     calling this twice is probably faster than if statements... */
+  sum = FOLD_U32T(sum);
+  sum = FOLD_U32T(sum);
+
+  /* Swap if alignment was odd */
+  if (odd) {
+    sum = SWAP_BYTES_IN_WORD(sum);
+  }
+
+  return (u16_t)sum;
+}
+#endif
+
+#if (LWIP_CHKSUM_ALGORITHM == 3) /* Alternative version #3 */
+/**
+ * An optimized checksum routine. Basically, it uses loop-unrolling on
+ * the checksum loop, treating the head and tail bytes specially, whereas
+ * the inner loop acts on 8 bytes at a time.
+ *
+ * @arg start of buffer to be checksummed. May be an odd byte address.
+ * @len number of bytes in the buffer to be checksummed.
+ * @return host order (!) lwip checksum (non-inverted Internet sum)
+ *
+ * by Curt McDowell, Broadcom Corp. December 8th, 2005
+ */
+u16_t
+lwip_standard_chksum(const void *dataptr, int len)
+{
+  const u8_t *pb = (const u8_t *)dataptr;
+  const u16_t *ps;
+  u16_t t = 0;
+  const u32_t *pl;
+  u32_t sum = 0, tmp;
+  /* starts at odd byte address? */
+  int odd = ((mem_ptr_t)pb & 1);
+
+  if (odd && len > 0) {
+    ((u8_t *)&t)[1] = *pb++;
+    len--;
+  }
+
+  ps = (const u16_t *)(const void*)pb;
+
+  if (((mem_ptr_t)ps & 3) && len > 1) {
+    sum += *ps++;
+    len -= 2;
+  }
+
+  pl = (const u32_t *)(const void*)ps;
+
+  while (len > 7)  {
+    tmp = sum + *pl++;          /* ping */
+    if (tmp < sum) {
+      tmp++;                    /* add back carry */
+    }
+
+    sum = tmp + *pl++;          /* pong */
+    if (sum < tmp) {
+      sum++;                    /* add back carry */
+    }
+
+    len -= 8;
+  }
+
+  /* make room in upper bits */
+  sum = FOLD_U32T(sum);
+
+  ps = (const u16_t *)pl;
+
+  /* 16-bit aligned word remaining? */
+  while (len > 1) {
+    sum += *ps++;
+    len -= 2;
+  }
+
+  /* dangling tail byte remaining? */
+  if (len > 0) {                /* include odd byte */
+    ((u8_t *)&t)[0] = *(const u8_t *)ps;
+  }
+
+  sum += t;                     /* add end bytes */
+
+  /* Fold 32-bit sum to 16 bits
+     calling this twice is probably faster than if statements... */
+  sum = FOLD_U32T(sum);
+  sum = FOLD_U32T(sum);
+
+  if (odd) {
+    sum = SWAP_BYTES_IN_WORD(sum);
+  }
+
+  return (u16_t)sum;
+}
+#endif
+
+/** Parts of the pseudo checksum which are common to IPv4 and IPv6 */
+static u16_t
+inet_cksum_pseudo_base(struct pbuf *p, u8_t proto, u16_t proto_len, u32_t acc)
+{
+  struct pbuf *q;
+  u8_t swapped = 0;
+
+  /* iterate through all pbuf in chain */
+  for (q = p; q != NULL; q = q->next) {
+    LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
+      (void *)q, (void *)q->next));
+    acc += LWIP_CHKSUM(q->payload, q->len);
+    /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
+    /* just executing this next line is probably faster that the if statement needed
+       to check whether we really need to execute it, and does no harm */
+    acc = FOLD_U32T(acc);
+    if (q->len % 2 != 0) {
+      swapped = 1 - swapped;
+      acc = SWAP_BYTES_IN_WORD(acc);
+    }
+    /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
+  }
+
+  if (swapped) {
+    acc = SWAP_BYTES_IN_WORD(acc);
+  }
+
+  acc += (u32_t)htons((u16_t)proto);
+  acc += (u32_t)htons(proto_len);
+
+  /* Fold 32-bit sum to 16 bits
+     calling this twice is probably faster than if statements... */
+  acc = FOLD_U32T(acc);
+  acc = FOLD_U32T(acc);
+  LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
+  return (u16_t)~(acc & 0xffffUL);
+}
+
+#if LWIP_IPV4
+/* inet_chksum_pseudo:
+ *
+ * Calculates the IPv4 pseudo Internet checksum used by TCP and UDP for a pbuf chain.
+ * IP addresses are expected to be in network byte order.
+ *
+ * @param p chain of pbufs over that a checksum should be calculated (ip data part)
+ * @param src source ip address (used for checksum of pseudo header)
+ * @param dst destination ip address (used for checksum of pseudo header)
+ * @param proto ip protocol (used for checksum of pseudo header)
+ * @param proto_len length of the ip data part (used for checksum of pseudo header)
+ * @return checksum (as u16_t) to be saved directly in the protocol header
+ */
+u16_t
+inet_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
+       const ip4_addr_t *src, const ip4_addr_t *dest)
+{
+  u32_t acc;
+  u32_t addr;
+
+  addr = ip4_addr_get_u32(src);
+  acc = (addr & 0xffffUL);
+  acc += ((addr >> 16) & 0xffffUL);
+  addr = ip4_addr_get_u32(dest);
+  acc += (addr & 0xffffUL);
+  acc += ((addr >> 16) & 0xffffUL);
+  /* fold down to 16 bits */
+  acc = FOLD_U32T(acc);
+  acc = FOLD_U32T(acc);
+
+  return inet_cksum_pseudo_base(p, proto, proto_len, acc);
+}
+#endif /* LWIP_IPV4 */
+
+#if LWIP_IPV6
+/**
+ * Calculates the checksum with IPv6 pseudo header used by TCP and UDP for a pbuf chain.
+ * IPv6 addresses are expected to be in network byte order.
+ *
+ * @param p chain of pbufs over that a checksum should be calculated (ip data part)
+ * @param proto ipv6 protocol/next header (used for checksum of pseudo header)
+ * @param proto_len length of the ipv6 payload (used for checksum of pseudo header)
+ * @param src source ipv6 address (used for checksum of pseudo header)
+ * @param dest destination ipv6 address (used for checksum of pseudo header)
+ * @return checksum (as u16_t) to be saved directly in the protocol header
+ */
+u16_t
+ip6_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
+       const ip6_addr_t *src, const ip6_addr_t *dest)
+{
+  u32_t acc = 0;
+  u32_t addr;
+  u8_t addr_part;
+
+  for (addr_part = 0; addr_part < 4; addr_part++) {
+    addr = src->addr[addr_part];
+    acc += (addr & 0xffffUL);
+    acc += ((addr >> 16) & 0xffffUL);
+    addr = dest->addr[addr_part];
+    acc += (addr & 0xffffUL);
+    acc += ((addr >> 16) & 0xffffUL);
+  }
+  /* fold down to 16 bits */
+  acc = FOLD_U32T(acc);
+  acc = FOLD_U32T(acc);
+
+  return inet_cksum_pseudo_base(p, proto, proto_len, acc);
+}
+#endif /* LWIP_IPV6 */
+
+/* ip_chksum_pseudo:
+ *
+ * Calculates the IPv4 or IPv6 pseudo Internet checksum used by TCP and UDP for a pbuf chain.
+ * IP addresses are expected to be in network byte order.
+ *
+ * @param p chain of pbufs over that a checksum should be calculated (ip data part)
+ * @param src source ip address (used for checksum of pseudo header)
+ * @param dst destination ip address (used for checksum of pseudo header)
+ * @param proto ip protocol (used for checksum of pseudo header)
+ * @param proto_len length of the ip data part (used for checksum of pseudo header)
+ * @return checksum (as u16_t) to be saved directly in the protocol header
+ */
+u16_t
+ip_chksum_pseudo(struct pbuf *p, u8_t proto, u16_t proto_len,
+       const ip_addr_t *src, const ip_addr_t *dest)
+{
+#if LWIP_IPV6
+  if (IP_IS_V6(dest)) {
+    return ip6_chksum_pseudo(p, proto, proto_len, ip_2_ip6(src), ip_2_ip6(dest));
+  }
+#endif /* LWIP_IPV6 */
+#if LWIP_IPV4 && LWIP_IPV6
+  else
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+#if LWIP_IPV4
+  {
+    return inet_chksum_pseudo(p, proto, proto_len, ip_2_ip4(src), ip_2_ip4(dest));
+  }
+#endif /* LWIP_IPV4 */
+}
+
+/** Parts of the pseudo checksum which are common to IPv4 and IPv6 */
+static u16_t
+inet_cksum_pseudo_partial_base(struct pbuf *p, u8_t proto, u16_t proto_len,
+       u16_t chksum_len, u32_t acc)
+{
+  struct pbuf *q;
+  u8_t swapped = 0;
+  u16_t chklen;
+
+  /* iterate through all pbuf in chain */
+  for (q = p; (q != NULL) && (chksum_len > 0); q = q->next) {
+    LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): checksumming pbuf %p (has next %p) \n",
+      (void *)q, (void *)q->next));
+    chklen = q->len;
+    if (chklen > chksum_len) {
+      chklen = chksum_len;
+    }
+    acc += LWIP_CHKSUM(q->payload, chklen);
+    chksum_len -= chklen;
+    LWIP_ASSERT("delete me", chksum_len < 0x7fff);
+    /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): unwrapped lwip_chksum()=%"X32_F" \n", acc));*/
+    /* fold the upper bit down */
+    acc = FOLD_U32T(acc);
+    if (q->len % 2 != 0) {
+      swapped = 1 - swapped;
+      acc = SWAP_BYTES_IN_WORD(acc);
+    }
+    /*LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): wrapped lwip_chksum()=%"X32_F" \n", acc));*/
+  }
+
+  if (swapped) {
+    acc = SWAP_BYTES_IN_WORD(acc);
+  }
+
+  acc += (u32_t)htons((u16_t)proto);
+  acc += (u32_t)htons(proto_len);
+
+  /* Fold 32-bit sum to 16 bits
+     calling this twice is probably faster than if statements... */
+  acc = FOLD_U32T(acc);
+  acc = FOLD_U32T(acc);
+  LWIP_DEBUGF(INET_DEBUG, ("inet_chksum_pseudo(): pbuf chain lwip_chksum()=%"X32_F"\n", acc));
+  return (u16_t)~(acc & 0xffffUL);
+}
+
+#if LWIP_IPV4
+/* inet_chksum_pseudo_partial:
+ *
+ * Calculates the IPv4 pseudo Internet checksum used by TCP and UDP for a pbuf chain.
+ * IP addresses are expected to be in network byte order.
+ *
+ * @param p chain of pbufs over that a checksum should be calculated (ip data part)
+ * @param src source ip address (used for checksum of pseudo header)
+ * @param dst destination ip address (used for checksum of pseudo header)
+ * @param proto ip protocol (used for checksum of pseudo header)
+ * @param proto_len length of the ip data part (used for checksum of pseudo header)
+ * @return checksum (as u16_t) to be saved directly in the protocol header
+ */
+u16_t
+inet_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len,
+       u16_t chksum_len, const ip4_addr_t *src, const ip4_addr_t *dest)
+{
+  u32_t acc;
+  u32_t addr;
+
+  addr = ip4_addr_get_u32(src);
+  acc = (addr & 0xffffUL);
+  acc += ((addr >> 16) & 0xffffUL);
+  addr = ip4_addr_get_u32(dest);
+  acc += (addr & 0xffffUL);
+  acc += ((addr >> 16) & 0xffffUL);
+  /* fold down to 16 bits */
+  acc = FOLD_U32T(acc);
+  acc = FOLD_U32T(acc);
+
+  return inet_cksum_pseudo_partial_base(p, proto, proto_len, chksum_len, acc);
+}
+#endif /* LWIP_IPV4 */
+
+#if LWIP_IPV6
+/**
+ * Calculates the checksum with IPv6 pseudo header used by TCP and UDP for a pbuf chain.
+ * IPv6 addresses are expected to be in network byte order. Will only compute for a
+ * portion of the payload.
+ *
+ * @param p chain of pbufs over that a checksum should be calculated (ip data part)
+ * @param proto ipv6 protocol/next header (used for checksum of pseudo header)
+ * @param proto_len length of the ipv6 payload (used for checksum of pseudo header)
+ * @param chksum_len number of payload bytes used to compute chksum
+ * @param src source ipv6 address (used for checksum of pseudo header)
+ * @param dest destination ipv6 address (used for checksum of pseudo header)
+ * @return checksum (as u16_t) to be saved directly in the protocol header
+ */
+u16_t
+ip6_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len,
+       u16_t chksum_len, const ip6_addr_t *src, const ip6_addr_t *dest)
+{
+  u32_t acc = 0;
+  u32_t addr;
+  u8_t addr_part;
+
+  for (addr_part = 0; addr_part < 4; addr_part++) {
+    addr = src->addr[addr_part];
+    acc += (addr & 0xffffUL);
+    acc += ((addr >> 16) & 0xffffUL);
+    addr = dest->addr[addr_part];
+    acc += (addr & 0xffffUL);
+    acc += ((addr >> 16) & 0xffffUL);
+  }
+  /* fold down to 16 bits */
+  acc = FOLD_U32T(acc);
+  acc = FOLD_U32T(acc);
+
+  return inet_cksum_pseudo_partial_base(p, proto, proto_len, chksum_len, acc);
+}
+#endif /* LWIP_IPV6 */
+
+/* ip_chksum_pseudo_partial:
+ *
+ * Calculates the IPv4 or IPv6 pseudo Internet checksum used by TCP and UDP for a pbuf chain.
+ *
+ * @param p chain of pbufs over that a checksum should be calculated (ip data part)
+ * @param src source ip address (used for checksum of pseudo header)
+ * @param dst destination ip address (used for checksum of pseudo header)
+ * @param proto ip protocol (used for checksum of pseudo header)
+ * @param proto_len length of the ip data part (used for checksum of pseudo header)
+ * @return checksum (as u16_t) to be saved directly in the protocol header
+ */
+u16_t
+ip_chksum_pseudo_partial(struct pbuf *p, u8_t proto, u16_t proto_len,
+       u16_t chksum_len, const ip_addr_t *src, const ip_addr_t *dest)
+{
+#if LWIP_IPV6
+  if (IP_IS_V6(dest)) {
+    return ip6_chksum_pseudo_partial(p, proto, proto_len, chksum_len, ip_2_ip6(src), ip_2_ip6(dest));
+  }
+#endif /* LWIP_IPV6 */
+#if LWIP_IPV4 && LWIP_IPV6
+  else
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+#if LWIP_IPV4
+  {
+    return inet_chksum_pseudo_partial(p, proto, proto_len, chksum_len, ip_2_ip4(src), ip_2_ip4(dest));
+  }
+#endif /* LWIP_IPV4 */
+}
+
+/* inet_chksum:
+ *
+ * Calculates the Internet checksum over a portion of memory. Used primarily for IP
+ * and ICMP.
+ *
+ * @param dataptr start of the buffer to calculate the checksum (no alignment needed)
+ * @param len length of the buffer to calculate the checksum
+ * @return checksum (as u16_t) to be saved directly in the protocol header
+ */
+
+u16_t
+inet_chksum(const void *dataptr, u16_t len)
+{
+  return (u16_t)~(unsigned int)LWIP_CHKSUM(dataptr, len);
+}
+
+/**
+ * Calculate a checksum over a chain of pbufs (without pseudo-header, much like
+ * inet_chksum only pbufs are used).
+ *
+ * @param p pbuf chain over that the checksum should be calculated
+ * @return checksum (as u16_t) to be saved directly in the protocol header
+ */
+u16_t
+inet_chksum_pbuf(struct pbuf *p)
+{
+  u32_t acc;
+  struct pbuf *q;
+  u8_t swapped;
+
+  acc = 0;
+  swapped = 0;
+  for (q = p; q != NULL; q = q->next) {
+    acc += LWIP_CHKSUM(q->payload, q->len);
+    acc = FOLD_U32T(acc);
+    if (q->len % 2 != 0) {
+      swapped = 1 - swapped;
+      acc = SWAP_BYTES_IN_WORD(acc);
+    }
+  }
+
+  if (swapped) {
+    acc = SWAP_BYTES_IN_WORD(acc);
+  }
+  return (u16_t)~(acc & 0xffffUL);
+}
+
+/* These are some implementations for LWIP_CHKSUM_COPY, which copies data
+ * like MEMCPY but generates a checksum at the same time. Since this is a
+ * performance-sensitive function, you might want to create your own version
+ * in assembly targeted at your hardware by defining it in lwipopts.h:
+ *   #define LWIP_CHKSUM_COPY(dst, src, len) your_chksum_copy(dst, src, len)
+ */
+
+#if (LWIP_CHKSUM_COPY_ALGORITHM == 1) /* Version #1 */
+/** Safe but slow: first call MEMCPY, then call LWIP_CHKSUM.
+ * For architectures with big caches, data might still be in cache when
+ * generating the checksum after copying.
+ */
+u16_t
+lwip_chksum_copy(void *dst, const void *src, u16_t len)
+{
+  MEMCPY(dst, src, len);
+  return LWIP_CHKSUM(dst, len);
+}
+#endif /* (LWIP_CHKSUM_COPY_ALGORITHM == 1) */

ext/lwip/src/core/init.c

@@ -0,0 +1,388 @@
+/**
+ * @file
+ * Modules initialization
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ */
+
+/**
+ * @defgroup lwip_nosys Mainloop mode ("NO_SYS")
+ * @ingroup lwip
+ * Use this mode if you do not run an OS on your system. \#define NO_SYS to 1.
+ * Feed incoming packets to netif->input(pbuf, netif) function from mainloop,
+ * *not* *from* *interrupt* *context*. You can allocate a @ref pbuf in interrupt
+ * context and put them into a queue which is processed from mainloop.\n
+ * Call sys_check_timeouts() periodically in the mainloop.\n
+ * Porting: implement all functions in @ref sys_time and @ref sys_prot.\n
+ * You can only use @ref callbackstyle_api in this mode.
+ *
+ * @defgroup lwip_os OS mode (TCPIP thread)
+ * @ingroup lwip
+ * Use this mode if you run an OS on your system. It is recommended to
+ * use an RTOS that correctly handles priority inversion and
+ * to use LWIP_TCPIP_CORE_LOCKING.\n
+ * Porting: implement all functions in @ref sys_layer.\n
+ * You can use @ref callbackstyle_api together with \#define tcpip_callback,
+ * and all @ref threadsafe_api.
+ */
+
+#include "lwip/opt.h"
+
+#include "lwip/init.h"
+#include "lwip/stats.h"
+#include "lwip/sys.h"
+#include "lwip/mem.h"
+#include "lwip/memp.h"
+#include "lwip/pbuf.h"
+#include "lwip/netif.h"
+#include "lwip/sockets.h"
+#include "lwip/ip.h"
+#include "lwip/raw.h"
+#include "lwip/udp.h"
+#include "lwip/priv/tcp_priv.h"
+#include "lwip/autoip.h"
+#include "lwip/igmp.h"
+#include "lwip/dns.h"
+#include "lwip/timeouts.h"
+#include "lwip/etharp.h"
+#include "lwip/ip6.h"
+#include "lwip/nd6.h"
+#include "lwip/mld6.h"
+#include "lwip/api.h"
+
+#include "netif/ppp/ppp_opts.h"
+#include "netif/ppp/ppp_impl.h"
+
+/* Compile-time sanity checks for configuration errors.
+ * These can be done independently of LWIP_DEBUG, without penalty.
+ */
+#ifndef BYTE_ORDER
+  #error "BYTE_ORDER is not defined, you have to define it in your cc.h"
+#endif
+#if (!IP_SOF_BROADCAST && IP_SOF_BROADCAST_RECV)
+  #error "If you want to use broadcast filter per pcb on recv operations, you have to define IP_SOF_BROADCAST=1 in your lwipopts.h"
+#endif
+#if (!LWIP_UDP && LWIP_UDPLITE)
+  #error "If you want to use UDP Lite, you have to define LWIP_UDP=1 in your lwipopts.h"
+#endif
+#if (!LWIP_UDP && LWIP_DHCP)
+  #error "If you want to use DHCP, you have to define LWIP_UDP=1 in your lwipopts.h"
+#endif
+#if (!LWIP_UDP && LWIP_MULTICAST_TX_OPTIONS)
+  #error "If you want to use IGMP/LWIP_MULTICAST_TX_OPTIONS, you have to define LWIP_UDP=1 in your lwipopts.h"
+#endif
+#if (!LWIP_UDP && LWIP_DNS)
+  #error "If you want to use DNS, you have to define LWIP_UDP=1 in your lwipopts.h"
+#endif
+#if !MEMP_MEM_MALLOC /* MEMP_NUM_* checks are disabled when not using the pool allocator */
+#if (LWIP_ARP && ARP_QUEUEING && (MEMP_NUM_ARP_QUEUE<=0))
+  #error "If you want to use ARP Queueing, you have to define MEMP_NUM_ARP_QUEUE>=1 in your lwipopts.h"
+#endif
+#if (LWIP_RAW && (MEMP_NUM_RAW_PCB<=0))
+  #error "If you want to use RAW, you have to define MEMP_NUM_RAW_PCB>=1 in your lwipopts.h"
+#endif
+#if (LWIP_UDP && (MEMP_NUM_UDP_PCB<=0))
+  #error "If you want to use UDP, you have to define MEMP_NUM_UDP_PCB>=1 in your lwipopts.h"
+#endif
+#if (LWIP_TCP && (MEMP_NUM_TCP_PCB<=0))
+  #error "If you want to use TCP, you have to define MEMP_NUM_TCP_PCB>=1 in your lwipopts.h"
+#endif
+#if (LWIP_IGMP && (MEMP_NUM_IGMP_GROUP<=1))
+  #error "If you want to use IGMP, you have to define MEMP_NUM_IGMP_GROUP>1 in your lwipopts.h"
+#endif
+#if (LWIP_IGMP && !LWIP_MULTICAST_TX_OPTIONS)
+  #error "If you want to use IGMP, you have to define LWIP_MULTICAST_TX_OPTIONS==1 in your lwipopts.h"
+#endif
+#if (LWIP_IGMP && !LWIP_IPV4)
+  #error "IGMP needs LWIP_IPV4 enabled in your lwipopts.h"
+#endif
+#if (LWIP_MULTICAST_TX_OPTIONS && !LWIP_IPV4)
+  #error "LWIP_MULTICAST_TX_OPTIONS needs LWIP_IPV4 enabled in your lwipopts.h"
+#endif
+#if ((LWIP_NETCONN || LWIP_SOCKET) && (MEMP_NUM_TCPIP_MSG_API<=0))
+  #error "If you want to use Sequential API, you have to define MEMP_NUM_TCPIP_MSG_API>=1 in your lwipopts.h"
+#endif
+/* There must be sufficient timeouts, taking into account requirements of the subsystems. */
+#if LWIP_TIMERS && (MEMP_NUM_SYS_TIMEOUT < (LWIP_TCP + IP_REASSEMBLY + LWIP_ARP + (2*LWIP_DHCP) + LWIP_AUTOIP + LWIP_IGMP + LWIP_DNS + PPP_SUPPORT + (LWIP_IPV6 ? (1 + LWIP_IPV6_REASS + LWIP_IPV6_MLD) : 0)))
+  #error "MEMP_NUM_SYS_TIMEOUT is too low to accomodate all required timeouts"
+#endif
+#if (IP_REASSEMBLY && (MEMP_NUM_REASSDATA > IP_REASS_MAX_PBUFS))
+  #error "MEMP_NUM_REASSDATA > IP_REASS_MAX_PBUFS doesn't make sense since each struct ip_reassdata must hold 2 pbufs at least!"
+#endif
+#endif /* !MEMP_MEM_MALLOC */
+#if LWIP_WND_SCALE
+#if (LWIP_TCP && (TCP_WND > 0xffffffff))
+  #error "If you want to use TCP, TCP_WND must fit in an u32_t, so, you have to reduce it in your lwipopts.h"
+#endif
+#if (LWIP_TCP && LWIP_WND_SCALE && (TCP_RCV_SCALE > 14))
+  #error "The maximum valid window scale value is 14!"
+#endif
+#if (LWIP_TCP && (TCP_WND > (0xFFFFU << TCP_RCV_SCALE)))
+  #error "TCP_WND is bigger than the configured LWIP_WND_SCALE allows!"
+#endif
+#if (LWIP_TCP && ((TCP_WND >> TCP_RCV_SCALE) == 0))
+  #error "TCP_WND is too small for the configured LWIP_WND_SCALE (results in zero window)!"
+#endif
+#else /* LWIP_WND_SCALE */
+#if (LWIP_TCP && (TCP_WND > 0xffff))
+  #error "If you want to use TCP, TCP_WND must fit in an u16_t, so, you have to reduce it in your lwipopts.h (or enable window scaling)"
+#endif
+#endif /* LWIP_WND_SCALE */
+#if (LWIP_TCP && (TCP_SND_QUEUELEN > 0xffff))
+  #error "If you want to use TCP, TCP_SND_QUEUELEN must fit in an u16_t, so, you have to reduce it in your lwipopts.h"
+#endif
+#if (LWIP_TCP && (TCP_SND_QUEUELEN < 2))
+  #error "TCP_SND_QUEUELEN must be at least 2 for no-copy TCP writes to work"
+#endif
+#if (LWIP_TCP && ((TCP_MAXRTX > 12) || (TCP_SYNMAXRTX > 12)))
+  #error "If you want to use TCP, TCP_MAXRTX and TCP_SYNMAXRTX must less or equal to 12 (due to tcp_backoff table), so, you have to reduce them in your lwipopts.h"
+#endif
+#if (LWIP_TCP && TCP_LISTEN_BACKLOG && ((TCP_DEFAULT_LISTEN_BACKLOG < 0) || (TCP_DEFAULT_LISTEN_BACKLOG > 0xff)))
+  #error "If you want to use TCP backlog, TCP_DEFAULT_LISTEN_BACKLOG must fit into an u8_t"
+#endif
+#if (LWIP_NETIF_API && (NO_SYS==1))
+  #error "If you want to use NETIF API, you have to define NO_SYS=0 in your lwipopts.h"
+#endif
+#if ((LWIP_SOCKET || LWIP_NETCONN) && (NO_SYS==1))
+  #error "If you want to use Sequential API, you have to define NO_SYS=0 in your lwipopts.h"
+#endif
+#if (LWIP_PPP_API && (NO_SYS==1))
+  #error "If you want to use PPP API, you have to define NO_SYS=0 in your lwipopts.h"
+#endif
+#if (LWIP_PPP_API && (PPP_SUPPORT==0))
+  #error "If you want to use PPP API, you have to enable PPP_SUPPORT in your lwipopts.h"
+#endif
+#if (((!LWIP_DHCP) || (!LWIP_AUTOIP)) && LWIP_DHCP_AUTOIP_COOP)
+  #error "If you want to use DHCP/AUTOIP cooperation mode, you have to define LWIP_DHCP=1 and LWIP_AUTOIP=1 in your lwipopts.h"
+#endif
+#if (((!LWIP_DHCP) || (!LWIP_ARP)) && DHCP_DOES_ARP_CHECK)
+  #error "If you want to use DHCP ARP checking, you have to define LWIP_DHCP=1 and LWIP_ARP=1 in your lwipopts.h"
+#endif
+#if (!LWIP_ARP && LWIP_AUTOIP)
+  #error "If you want to use AUTOIP, you have to define LWIP_ARP=1 in your lwipopts.h"
+#endif
+#if (LWIP_TCP && ((LWIP_EVENT_API && LWIP_CALLBACK_API) || (!LWIP_EVENT_API && !LWIP_CALLBACK_API)))
+  #error "One and exactly one of LWIP_EVENT_API and LWIP_CALLBACK_API has to be enabled in your lwipopts.h"
+#endif
+#if (MEM_LIBC_MALLOC && MEM_USE_POOLS)
+  #error "MEM_LIBC_MALLOC and MEM_USE_POOLS may not both be simultaneously enabled in your lwipopts.h"
+#endif
+#if (MEM_USE_POOLS && !MEMP_USE_CUSTOM_POOLS)
+  #error "MEM_USE_POOLS requires custom pools (MEMP_USE_CUSTOM_POOLS) to be enabled in your lwipopts.h"
+#endif
+#if (PBUF_POOL_BUFSIZE <= MEM_ALIGNMENT)
+  #error "PBUF_POOL_BUFSIZE must be greater than MEM_ALIGNMENT or the offset may take the full first pbuf"
+#endif
+#if (DNS_LOCAL_HOSTLIST && !DNS_LOCAL_HOSTLIST_IS_DYNAMIC && !(defined(DNS_LOCAL_HOSTLIST_INIT)))
+  #error "you have to define define DNS_LOCAL_HOSTLIST_INIT {{'host1', 0x123}, {'host2', 0x234}} to initialize DNS_LOCAL_HOSTLIST"
+#endif
+#if PPP_SUPPORT && !PPPOS_SUPPORT && !PPPOE_SUPPORT && !PPPOL2TP_SUPPORT
+  #error "PPP_SUPPORT needs at least one of PPPOS_SUPPORT, PPPOE_SUPPORT or PPPOL2TP_SUPPORT turned on"
+#endif
+#if PPP_SUPPORT && !PPP_IPV4_SUPPORT && !PPP_IPV6_SUPPORT
+  #error "PPP_SUPPORT needs PPP_IPV4_SUPPORT and/or PPP_IPV6_SUPPORT turned on"
+#endif
+#if PPP_SUPPORT && PPP_IPV4_SUPPORT && !LWIP_IPV4
+  #error "PPP_IPV4_SUPPORT needs LWIP_IPV4 turned on"
+#endif
+#if PPP_SUPPORT && PPP_IPV6_SUPPORT && !LWIP_IPV6
+  #error "PPP_IPV6_SUPPORT needs LWIP_IPV6 turned on"
+#endif
+#if !LWIP_ETHERNET && (LWIP_ARP || PPPOE_SUPPORT)
+  #error "LWIP_ETHERNET needs to be turned on for LWIP_ARP or PPPOE_SUPPORT"
+#endif
+#if (LWIP_IGMP || LWIP_IPV6) && !defined(LWIP_RAND)
+  #error "When using IGMP or IPv6, LWIP_RAND() needs to be defined to a random-function returning an u32_t random value"
+#endif
+#if LWIP_TCPIP_CORE_LOCKING_INPUT && !LWIP_TCPIP_CORE_LOCKING
+  #error "When using LWIP_TCPIP_CORE_LOCKING_INPUT, LWIP_TCPIP_CORE_LOCKING must be enabled, too"
+#endif
+#if LWIP_TCP && LWIP_NETIF_TX_SINGLE_PBUF && !TCP_OVERSIZE
+  #error "LWIP_NETIF_TX_SINGLE_PBUF needs TCP_OVERSIZE enabled to create single-pbuf TCP packets"
+#endif
+#if IP_FRAG && IP_FRAG_USES_STATIC_BUF && LWIP_NETIF_TX_SINGLE_PBUF
+  #error "LWIP_NETIF_TX_SINGLE_PBUF does not work with IP_FRAG_USES_STATIC_BUF==1 as that creates pbuf queues"
+#endif
+#if LWIP_NETCONN && LWIP_TCP
+#if NETCONN_COPY != TCP_WRITE_FLAG_COPY
+  #error "NETCONN_COPY != TCP_WRITE_FLAG_COPY"
+#endif
+#if NETCONN_MORE != TCP_WRITE_FLAG_MORE
+  #error "NETCONN_MORE != TCP_WRITE_FLAG_MORE"
+#endif
+#endif /* LWIP_NETCONN && LWIP_TCP */
+#if LWIP_SOCKET
+/* Check that the SO_* socket options and SOF_* lwIP-internal flags match */
+#if SO_REUSEADDR != SOF_REUSEADDR
+  #error "WARNING: SO_REUSEADDR != SOF_REUSEADDR"
+#endif
+#if SO_KEEPALIVE != SOF_KEEPALIVE
+  #error "WARNING: SO_KEEPALIVE != SOF_KEEPALIVE"
+#endif
+#if SO_BROADCAST != SOF_BROADCAST
+  #error "WARNING: SO_BROADCAST != SOF_BROADCAST"
+#endif
+#endif /* LWIP_SOCKET */
+
+
+/* Compile-time checks for deprecated options.
+ */
+#ifdef MEMP_NUM_TCPIP_MSG
+  #error "MEMP_NUM_TCPIP_MSG option is deprecated. Remove it from your lwipopts.h."
+#endif
+#ifdef TCP_REXMIT_DEBUG
+  #error "TCP_REXMIT_DEBUG option is deprecated. Remove it from your lwipopts.h."
+#endif
+#ifdef RAW_STATS
+  #error "RAW_STATS option is deprecated. Remove it from your lwipopts.h."
+#endif
+#ifdef ETHARP_QUEUE_FIRST
+  #error "ETHARP_QUEUE_FIRST option is deprecated. Remove it from your lwipopts.h."
+#endif
+#ifdef ETHARP_ALWAYS_INSERT
+  #error "ETHARP_ALWAYS_INSERT option is deprecated. Remove it from your lwipopts.h."
+#endif
+#if !NO_SYS && LWIP_TCPIP_CORE_LOCKING && LWIP_COMPAT_MUTEX && !defined(LWIP_COMPAT_MUTEX_ALLOWED)
+  #error "LWIP_COMPAT_MUTEX cannot prevent priority inversion. It is recommended to implement priority-aware mutexes. (Define LWIP_COMPAT_MUTEX_ALLOWED to disable this error.)"
+#endif
+
+#ifndef LWIP_DISABLE_TCP_SANITY_CHECKS
+#define LWIP_DISABLE_TCP_SANITY_CHECKS  0
+#endif
+#ifndef LWIP_DISABLE_MEMP_SANITY_CHECKS
+#define LWIP_DISABLE_MEMP_SANITY_CHECKS 0
+#endif
+
+/* MEMP sanity checks */
+#if MEMP_MEM_MALLOC
+#if !LWIP_DISABLE_MEMP_SANITY_CHECKS
+#if LWIP_NETCONN || LWIP_SOCKET
+#if !MEMP_NUM_NETCONN && LWIP_SOCKET
+#error "lwip_sanity_check: WARNING: MEMP_NUM_NETCONN cannot be 0 when using sockets!"
+#endif
+#else /* MEMP_MEM_MALLOC */
+#if MEMP_NUM_NETCONN > (MEMP_NUM_TCP_PCB+MEMP_NUM_TCP_PCB_LISTEN+MEMP_NUM_UDP_PCB+MEMP_NUM_RAW_PCB)
+#error "lwip_sanity_check: WARNING: MEMP_NUM_NETCONN should be less than the sum of MEMP_NUM_{TCP,RAW,UDP}_PCB+MEMP_NUM_TCP_PCB_LISTEN. If you know what you are doing, define LWIP_DISABLE_MEMP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#endif /* LWIP_NETCONN || LWIP_SOCKET */
+#endif /* !LWIP_DISABLE_MEMP_SANITY_CHECKS */
+#if MEM_USE_POOLS
+#error "MEMP_MEM_MALLOC and MEM_USE_POOLS cannot be enabled at the same time"
+#endif
+#ifdef LWIP_HOOK_MEMP_AVAILABLE
+#error "LWIP_HOOK_MEMP_AVAILABLE doesn't make sense with MEMP_MEM_MALLOC"
+#endif
+#endif /* MEMP_MEM_MALLOC */
+
+/* TCP sanity checks */
+#if !LWIP_DISABLE_TCP_SANITY_CHECKS
+#if LWIP_TCP
+#if !MEMP_MEM_MALLOC && (MEMP_NUM_TCP_SEG < TCP_SND_QUEUELEN)
+  #error "lwip_sanity_check: WARNING: MEMP_NUM_TCP_SEG should be at least as big as TCP_SND_QUEUELEN. If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#if TCP_SND_BUF < (2 * TCP_MSS)
+  #error "lwip_sanity_check: WARNING: TCP_SND_BUF must be at least as much as (2 * TCP_MSS) for things to work smoothly. If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#if TCP_SND_QUEUELEN < (2 * (TCP_SND_BUF / TCP_MSS))
+  #error "lwip_sanity_check: WARNING: TCP_SND_QUEUELEN must be at least as much as (2 * TCP_SND_BUF/TCP_MSS) for things to work. If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#if TCP_SNDLOWAT >= TCP_SND_BUF
+  #error "lwip_sanity_check: WARNING: TCP_SNDLOWAT must be less than TCP_SND_BUF. If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#if TCP_SNDLOWAT >= (0xFFFF - (4 * TCP_MSS))
+  #error "lwip_sanity_check: WARNING: TCP_SNDLOWAT must at least be 4*MSS below u16_t overflow!"
+#endif
+#if TCP_SNDQUEUELOWAT >= TCP_SND_QUEUELEN
+  #error "lwip_sanity_check: WARNING: TCP_SNDQUEUELOWAT must be less than TCP_SND_QUEUELEN. If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#if !MEMP_MEM_MALLOC && (PBUF_POOL_BUFSIZE <= (PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN))
+  #error "lwip_sanity_check: WARNING: PBUF_POOL_BUFSIZE does not provide enough space for protocol headers. If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#if !MEMP_MEM_MALLOC && (TCP_WND > (PBUF_POOL_SIZE * (PBUF_POOL_BUFSIZE - (PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN))))
+  #error "lwip_sanity_check: WARNING: TCP_WND is larger than space provided by PBUF_POOL_SIZE * (PBUF_POOL_BUFSIZE - protocol headers). If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#if TCP_WND < TCP_MSS
+  #error "lwip_sanity_check: WARNING: TCP_WND is smaller than MSS. If you know what you are doing, define LWIP_DISABLE_TCP_SANITY_CHECKS to 1 to disable this error."
+#endif
+#endif /* LWIP_TCP */
+#endif /* !LWIP_DISABLE_TCP_SANITY_CHECKS */
+
+/**
+ * @ingroup lwip_nosys
+ * Initialize all modules.
+ * Use this in NO_SYS mode. Use tcpip_init() otherwise.
+ */
+void
+lwip_init(void)
+{
+  /* Modules initialization */
+  stats_init();
+#if !NO_SYS
+  sys_init();
+#endif /* !NO_SYS */
+  mem_init();
+  memp_init();
+  pbuf_init();
+  netif_init();
+#if LWIP_IPV4
+  ip_init();
+#if LWIP_ARP
+  etharp_init();
+#endif /* LWIP_ARP */
+#endif /* LWIP_IPV4 */
+#if LWIP_RAW
+  raw_init();
+#endif /* LWIP_RAW */
+#if LWIP_UDP
+  udp_init();
+#endif /* LWIP_UDP */
+#if LWIP_TCP
+  tcp_init();
+#endif /* LWIP_TCP */
+#if LWIP_AUTOIP
+  autoip_init();
+#endif /* LWIP_AUTOIP */
+#if LWIP_IGMP
+  igmp_init();
+#endif /* LWIP_IGMP */
+#if LWIP_DNS
+  dns_init();
+#endif /* LWIP_DNS */
+#if PPP_SUPPORT
+  ppp_init();
+#endif
+ 
+#if LWIP_TIMERS
+  sys_timeouts_init();
+#endif /* LWIP_TIMERS */
+}

ext/lwip/src/core/ip.c

@@ -0,0 +1,124 @@
+/**
+ * @file ip.c
+ * Common IPv4 and IPv6 code
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+/**
+ * @defgroup ip4 IPv4
+ * @ingroup callbackstyle_api
+ *
+ * @defgroup ip6 IPv6
+ * @ingroup callbackstyle_api
+ * 
+ * @defgroup ipaddr IP address handling
+ * @ingroup infrastructure
+ * 
+ * @defgroup ip4addr IPv4 only
+ * @ingroup ipaddr
+ * 
+ * @defgroup ip6addr IPv6 only
+ * @ingroup ipaddr
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV4 || LWIP_IPV6
+
+#include "lwip/ip_addr.h"
+#include "lwip/ip.h"
+
+/** Global data for both IPv4 and IPv6 */
+struct ip_globals ip_data;
+
+#if LWIP_IPV4 && LWIP_IPV6
+
+const ip_addr_t ip_addr_any_type = IPADDR_ANY_TYPE_INIT;
+
+/**
+ * @ingroup ipaddr
+ * Convert IP address string (both versions) to numeric.
+ * The version is auto-detected from the string.
+ *
+ * @param cp IP address string to convert
+ * @param addr conversion result is stored here
+ * @return 1 on success, 0 on error
+ */
+int
+ipaddr_aton(const char *cp, ip_addr_t *addr)
+{
+  if (cp != NULL) {
+    const char* c;
+    for (c = cp; *c != 0; c++) {
+      if (*c == ':') {
+        /* contains a colon: IPv6 address */
+        if (addr) {
+          IP_SET_TYPE_VAL(*addr, IPADDR_TYPE_V6);
+        }
+        return ip6addr_aton(cp, ip_2_ip6(addr));
+      } else if (*c == '.') {
+        /* contains a dot: IPv4 address */
+        break;
+      }
+    }
+    /* call ip4addr_aton as fallback or if IPv4 was found */
+    if (addr) {
+      IP_SET_TYPE_VAL(*addr, IPADDR_TYPE_V4);
+    }
+    return ip4addr_aton(cp, ip_2_ip4(addr));
+  }
+  return 0;
+}
+
+/**
+ * @ingroup lwip_nosys
+ * If both IP versions are enabled, this function can dispatch packets to the correct one.
+ * Don't call directly, pass to netif_add() and call netif->input().
+ */
+err_t
+ip_input(struct pbuf *p, struct netif *inp)
+{
+  if (p != NULL) {
+    if (IP_HDR_GET_VERSION(p->payload) == 6) {
+      return ip6_input(p, inp);
+    }
+    return ip4_input(p, inp);
+  }
+  return ERR_VAL;
+}
+
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+
+#endif /* LWIP_IPV4 || LWIP_IPV6 */

ext/lwip/src/core/ipv4/autoip.c

@@ -0,0 +1,546 @@
+/**
+ * @file
+ * AutoIP Automatic LinkLocal IP Configuration
+ *
+ */
+
+/*
+ *
+ * Copyright (c) 2007 Dominik Spies <kontakt@dspies.de>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * Author: Dominik Spies <kontakt@dspies.de>
+ *
+ * This is a AutoIP implementation for the lwIP TCP/IP stack. It aims to conform
+ * with RFC 3927.
+ *
+ *
+ * Please coordinate changes and requests with Dominik Spies
+ * <kontakt@dspies.de>
+ */
+
+/*******************************************************************************
+ * USAGE:
+ *
+ * define LWIP_AUTOIP 1  in your lwipopts.h
+ *
+ * If you don't use tcpip.c (so, don't call, you don't call tcpip_init):
+ * - First, call autoip_init().
+ * - call autoip_tmr() all AUTOIP_TMR_INTERVAL msces,
+ *   that should be defined in autoip.h.
+ *   I recommend a value of 100. The value must divide 1000 with a remainder almost 0.
+ *   Possible values are 1000, 500, 333, 250, 200, 166, 142, 125, 111, 100 ....
+ *
+ * Without DHCP:
+ * - Call autoip_start() after netif_add().
+ *
+ * With DHCP:
+ * - define LWIP_DHCP_AUTOIP_COOP 1 in your lwipopts.h.
+ * - Configure your DHCP Client.
+ *
+ */
+
+/**
+ * @defgroup autoip AUTOIP
+ * @ingroup ip4
+ * AUTOIP related functions
+ * @see netifapi_autoip
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV4 && LWIP_AUTOIP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/mem.h"
+/* #include "lwip/udp.h" */
+#include "lwip/ip_addr.h"
+#include "lwip/netif.h"
+#include "lwip/autoip.h"
+#include "lwip/etharp.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+/* 169.254.0.0 */
+#define AUTOIP_NET         0xA9FE0000
+/* 169.254.1.0 */
+#define AUTOIP_RANGE_START (AUTOIP_NET | 0x0100)
+/* 169.254.254.255 */
+#define AUTOIP_RANGE_END   (AUTOIP_NET | 0xFEFF)
+
+/* RFC 3927 Constants */
+#define PROBE_WAIT               1   /* second   (initial random delay)                 */
+#define PROBE_MIN                1   /* second   (minimum delay till repeated probe)    */
+#define PROBE_MAX                2   /* seconds  (maximum delay till repeated probe)    */
+#define PROBE_NUM                3   /*          (number of probe packets)              */
+#define ANNOUNCE_NUM             2   /*          (number of announcement packets)       */
+#define ANNOUNCE_INTERVAL        2   /* seconds  (time between announcement packets)    */
+#define ANNOUNCE_WAIT            2   /* seconds  (delay before announcing)              */
+#define MAX_CONFLICTS            10  /*          (max conflicts before rate limiting)   */
+#define RATE_LIMIT_INTERVAL      60  /* seconds  (delay between successive attempts)    */
+#define DEFEND_INTERVAL          10  /* seconds  (min. wait between defensive ARPs)     */
+
+/* AutoIP client states */
+#define AUTOIP_STATE_OFF         0
+#define AUTOIP_STATE_PROBING     1
+#define AUTOIP_STATE_ANNOUNCING  2
+#define AUTOIP_STATE_BOUND       3
+
+/** Pseudo random macro based on netif informations.
+ * You could use "rand()" from the C Library if you define LWIP_AUTOIP_RAND in lwipopts.h */
+#ifndef LWIP_AUTOIP_RAND
+#define LWIP_AUTOIP_RAND(netif) ( (((u32_t)((netif->hwaddr[5]) & 0xff) << 24) | \
+                                   ((u32_t)((netif->hwaddr[3]) & 0xff) << 16) | \
+                                   ((u32_t)((netif->hwaddr[2]) & 0xff) << 8) | \
+                                   ((u32_t)((netif->hwaddr[4]) & 0xff))) + \
+                                   (netif->autoip?netif->autoip->tried_llipaddr:0))
+#endif /* LWIP_AUTOIP_RAND */
+
+/**
+ * Macro that generates the initial IP address to be tried by AUTOIP.
+ * If you want to override this, define it to something else in lwipopts.h.
+ */
+#ifndef LWIP_AUTOIP_CREATE_SEED_ADDR
+#define LWIP_AUTOIP_CREATE_SEED_ADDR(netif) \
+  htonl(AUTOIP_RANGE_START + ((u32_t)(((u8_t)(netif->hwaddr[4])) | \
+                 ((u32_t)((u8_t)(netif->hwaddr[5]))) << 8)))
+#endif /* LWIP_AUTOIP_CREATE_SEED_ADDR */
+
+/* static functions */
+static err_t autoip_arp_announce(struct netif *netif);
+static void autoip_start_probing(struct netif *netif);
+
+
+/**
+ * @ingroup autoip 
+ * Set a statically allocated struct autoip to work with.
+ * Using this prevents autoip_start to allocate it using mem_malloc.
+ *
+ * @param netif the netif for which to set the struct autoip
+ * @param autoip (uninitialised) autoip struct allocated by the application
+ */
+void
+autoip_set_struct(struct netif *netif, struct autoip *autoip)
+{
+  LWIP_ASSERT("netif != NULL", netif != NULL);
+  LWIP_ASSERT("autoip != NULL", autoip != NULL);
+  LWIP_ASSERT("netif already has a struct autoip set", netif->autoip == NULL);
+
+  /* clear data structure */
+  memset(autoip, 0, sizeof(struct autoip));
+  /* autoip->state = AUTOIP_STATE_OFF; */
+  netif->autoip = autoip;
+}
+
+/** Restart AutoIP client and check the next address (conflict detected)
+ *
+ * @param netif The netif under AutoIP control
+ */
+static void
+autoip_restart(struct netif *netif)
+{
+  netif->autoip->tried_llipaddr++;
+  autoip_start(netif);
+}
+
+/**
+ * Handle a IP address conflict after an ARP conflict detection
+ */
+static void
+autoip_handle_arp_conflict(struct netif *netif)
+{
+  /* RFC3927, 2.5 "Conflict Detection and Defense" allows two options where
+     a) means retreat on the first conflict and
+     b) allows to keep an already configured address when having only one
+        conflict in 10 seconds
+     We use option b) since it helps to improve the chance that one of the two
+     conflicting hosts may be able to retain its address. */
+
+  if (netif->autoip->lastconflict > 0) {
+    /* retreat, there was a conflicting ARP in the last DEFEND_INTERVAL seconds */
+    LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+      ("autoip_handle_arp_conflict(): we are defending, but in DEFEND_INTERVAL, retreating\n"));
+
+    /* Active TCP sessions are aborted when removing the ip addresss */
+    autoip_restart(netif);
+  } else {
+    LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+      ("autoip_handle_arp_conflict(): we are defend, send ARP Announce\n"));
+    autoip_arp_announce(netif);
+    netif->autoip->lastconflict = DEFEND_INTERVAL * AUTOIP_TICKS_PER_SECOND;
+  }
+}
+
+/**
+ * Create an IP-Address out of range 169.254.1.0 to 169.254.254.255
+ *
+ * @param netif network interface on which create the IP-Address
+ * @param ipaddr ip address to initialize
+ */
+static void
+autoip_create_addr(struct netif *netif, ip4_addr_t *ipaddr)
+{
+  /* Here we create an IP-Address out of range 169.254.1.0 to 169.254.254.255
+   * compliant to RFC 3927 Section 2.1
+   * We have 254 * 256 possibilities */
+
+  u32_t addr = ntohl(LWIP_AUTOIP_CREATE_SEED_ADDR(netif));
+  addr += netif->autoip->tried_llipaddr;
+  addr = AUTOIP_NET | (addr & 0xffff);
+  /* Now, 169.254.0.0 <= addr <= 169.254.255.255 */
+
+  if (addr < AUTOIP_RANGE_START) {
+    addr += AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
+  }
+  if (addr > AUTOIP_RANGE_END) {
+    addr -= AUTOIP_RANGE_END - AUTOIP_RANGE_START + 1;
+  }
+  LWIP_ASSERT("AUTOIP address not in range", (addr >= AUTOIP_RANGE_START) &&
+    (addr <= AUTOIP_RANGE_END));
+  ip4_addr_set_u32(ipaddr, htonl(addr));
+
+  LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+    ("autoip_create_addr(): tried_llipaddr=%"U16_F", %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
+    (u16_t)(netif->autoip->tried_llipaddr), ip4_addr1_16(ipaddr), ip4_addr2_16(ipaddr),
+    ip4_addr3_16(ipaddr), ip4_addr4_16(ipaddr)));
+}
+
+/**
+ * Sends an ARP probe from a network interface
+ *
+ * @param netif network interface used to send the probe
+ */
+static err_t
+autoip_arp_probe(struct netif *netif)
+{
+  /* this works because netif->ip_addr is ANY */
+  return etharp_request(netif, &netif->autoip->llipaddr);
+}
+
+/**
+ * Sends an ARP announce from a network interface
+ *
+ * @param netif network interface used to send the announce
+ */
+static err_t
+autoip_arp_announce(struct netif *netif)
+{
+  return etharp_gratuitous(netif);
+}
+
+/**
+ * Configure interface for use with current LL IP-Address
+ *
+ * @param netif network interface to configure with current LL IP-Address
+ */
+static err_t
+autoip_bind(struct netif *netif)
+{
+  struct autoip *autoip = netif->autoip;
+  ip4_addr_t sn_mask, gw_addr;
+
+  LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
+    ("autoip_bind(netif=%p) %c%c%"U16_F" %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
+    (void*)netif, netif->name[0], netif->name[1], (u16_t)netif->num,
+    ip4_addr1_16(&autoip->llipaddr), ip4_addr2_16(&autoip->llipaddr),
+    ip4_addr3_16(&autoip->llipaddr), ip4_addr4_16(&autoip->llipaddr)));
+
+  IP4_ADDR(&sn_mask, 255, 255, 0, 0);
+  IP4_ADDR(&gw_addr, 0, 0, 0, 0);
+
+  netif_set_addr(netif, &autoip->llipaddr, &sn_mask, &gw_addr);
+  /* interface is used by routing now that an address is set */
+
+  return ERR_OK;
+}
+
+/**
+ * @ingroup autoip 
+ * Start AutoIP client
+ *
+ * @param netif network interface on which start the AutoIP client
+ */
+err_t
+autoip_start(struct netif *netif)
+{
+  struct autoip *autoip = netif->autoip;
+  err_t result = ERR_OK;
+
+  LWIP_ERROR("netif is not up, old style port?", netif_is_up(netif), return ERR_ARG;);
+
+  /* Set IP-Address, Netmask and Gateway to 0 to make sure that
+   * ARP Packets are formed correctly
+   */
+  netif_set_addr(netif, IP4_ADDR_ANY, IP4_ADDR_ANY, IP4_ADDR_ANY);
+
+  LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+    ("autoip_start(netif=%p) %c%c%"U16_F"\n", (void*)netif, netif->name[0],
+    netif->name[1], (u16_t)netif->num));
+  if (autoip == NULL) {
+    /* no AutoIP client attached yet? */
+    LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
+      ("autoip_start(): starting new AUTOIP client\n"));
+    autoip = (struct autoip *)mem_malloc(sizeof(struct autoip));
+    if (autoip == NULL) {
+      LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
+        ("autoip_start(): could not allocate autoip\n"));
+      return ERR_MEM;
+    }
+    memset(autoip, 0, sizeof(struct autoip));
+    /* store this AutoIP client in the netif */
+    netif->autoip = autoip;
+    LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_start(): allocated autoip"));
+  } else {
+    autoip->state = AUTOIP_STATE_OFF;
+    autoip->ttw = 0;
+    autoip->sent_num = 0;
+    ip4_addr_set_zero(&autoip->llipaddr);
+    autoip->lastconflict = 0;
+  }
+
+  autoip_create_addr(netif, &(autoip->llipaddr));
+  autoip_start_probing(netif);
+
+  return result;
+}
+
+static void
+autoip_start_probing(struct netif *netif)
+{
+  struct autoip *autoip = netif->autoip;
+
+  autoip->state = AUTOIP_STATE_PROBING;
+  autoip->sent_num = 0;
+  LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+     ("autoip_start_probing(): changing state to PROBING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
+      ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
+      ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
+
+  /* time to wait to first probe, this is randomly
+   * chosen out of 0 to PROBE_WAIT seconds.
+   * compliant to RFC 3927 Section 2.2.1
+   */
+  autoip->ttw = (u16_t)(LWIP_AUTOIP_RAND(netif) % (PROBE_WAIT * AUTOIP_TICKS_PER_SECOND));
+
+  /*
+   * if we tried more then MAX_CONFLICTS we must limit our rate for
+   * acquiring and probing address
+   * compliant to RFC 3927 Section 2.2.1
+   */
+  if (autoip->tried_llipaddr > MAX_CONFLICTS) {
+    autoip->ttw = RATE_LIMIT_INTERVAL * AUTOIP_TICKS_PER_SECOND;
+  }
+}
+
+/**
+ * Handle a possible change in the network configuration.
+ *
+ * If there is an AutoIP address configured, take the interface down
+ * and begin probing with the same address.
+ */
+void
+autoip_network_changed(struct netif *netif)
+{
+  if (netif->autoip && netif->autoip->state != AUTOIP_STATE_OFF) {
+    autoip_start_probing(netif);
+  }
+}
+
+/**
+ * @ingroup autoip 
+ * Stop AutoIP client
+ *
+ * @param netif network interface on which stop the AutoIP client
+ */
+err_t
+autoip_stop(struct netif *netif)
+{
+  if (netif->autoip) {
+    netif->autoip->state = AUTOIP_STATE_OFF;
+    if (ip4_addr_islinklocal(netif_ip4_addr(netif))) {
+      netif_set_addr(netif, IP4_ADDR_ANY, IP4_ADDR_ANY, IP4_ADDR_ANY);
+    }
+  }
+  return ERR_OK;
+}
+
+/**
+ * Has to be called in loop every AUTOIP_TMR_INTERVAL milliseconds
+ */
+void
+autoip_tmr(void)
+{
+  struct netif *netif = netif_list;
+  /* loop through netif's */
+  while (netif != NULL) {
+    /* only act on AutoIP configured interfaces */
+    if (netif->autoip != NULL) {
+      if (netif->autoip->lastconflict > 0) {
+        netif->autoip->lastconflict--;
+      }
+
+      LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE,
+        ("autoip_tmr() AutoIP-State: %"U16_F", ttw=%"U16_F"\n",
+        (u16_t)(netif->autoip->state), netif->autoip->ttw));
+
+      if (netif->autoip->ttw > 0) {
+        netif->autoip->ttw--;
+      }
+
+      switch(netif->autoip->state) {
+        case AUTOIP_STATE_PROBING:
+          if (netif->autoip->ttw == 0) {
+            if (netif->autoip->sent_num >= PROBE_NUM) {
+              /* Switch to ANNOUNCING: now we can bind to an IP address and use it */
+              netif->autoip->state = AUTOIP_STATE_ANNOUNCING;
+              autoip_bind(netif);
+              /* autoip_bind() calls netif_set_addr(): this triggers a gratuitous ARP
+                 which counts as an announcement */
+              netif->autoip->sent_num = 1;
+              netif->autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
+              LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+                 ("autoip_tmr(): changing state to ANNOUNCING: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
+                  ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
+                  ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
+            } else {
+              autoip_arp_probe(netif);
+              LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() PROBING Sent Probe\n"));
+              netif->autoip->sent_num++;
+              if (netif->autoip->sent_num == PROBE_NUM) {
+                /* calculate time to wait to for announce */
+                netif->autoip->ttw = ANNOUNCE_WAIT * AUTOIP_TICKS_PER_SECOND;
+              } else {
+                /* calculate time to wait to next probe */
+                netif->autoip->ttw = (u16_t)((LWIP_AUTOIP_RAND(netif) %
+                  ((PROBE_MAX - PROBE_MIN) * AUTOIP_TICKS_PER_SECOND) ) +
+                  PROBE_MIN * AUTOIP_TICKS_PER_SECOND);
+              }
+            }
+          }
+          break;
+
+        case AUTOIP_STATE_ANNOUNCING:
+          if (netif->autoip->ttw == 0) {
+            autoip_arp_announce(netif);
+            LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_tmr() ANNOUNCING Sent Announce\n"));
+            netif->autoip->ttw = ANNOUNCE_INTERVAL * AUTOIP_TICKS_PER_SECOND;
+            netif->autoip->sent_num++;
+
+            if (netif->autoip->sent_num >= ANNOUNCE_NUM) {
+                netif->autoip->state = AUTOIP_STATE_BOUND;
+                netif->autoip->sent_num = 0;
+                netif->autoip->ttw = 0;
+                 LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+                    ("autoip_tmr(): changing state to BOUND: %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
+                     ip4_addr1_16(&netif->autoip->llipaddr), ip4_addr2_16(&netif->autoip->llipaddr),
+                     ip4_addr3_16(&netif->autoip->llipaddr), ip4_addr4_16(&netif->autoip->llipaddr)));
+            }
+          }
+          break;
+
+        default:
+          /* nothing to do in other states */
+          break;
+      }
+    }
+    /* proceed to next network interface */
+    netif = netif->next;
+  }
+}
+
+/**
+ * Handles every incoming ARP Packet, called by etharp_arp_input.
+ *
+ * @param netif network interface to use for autoip processing
+ * @param hdr Incoming ARP packet
+ */
+void
+autoip_arp_reply(struct netif *netif, struct etharp_hdr *hdr)
+{
+  LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE, ("autoip_arp_reply()\n"));
+  if ((netif->autoip != NULL) && (netif->autoip->state != AUTOIP_STATE_OFF)) {
+   /* when ip.src == llipaddr && hw.src != netif->hwaddr
+    *
+    * when probing  ip.dst == llipaddr && hw.src != netif->hwaddr
+    * we have a conflict and must solve it
+    */
+    ip4_addr_t sipaddr, dipaddr;
+    struct eth_addr netifaddr;
+    ETHADDR16_COPY(netifaddr.addr, netif->hwaddr);
+
+    /* Copy struct ip4_addr2 to aligned ip4_addr, to support compilers without
+     * structure packing (not using structure copy which breaks strict-aliasing rules).
+     */
+    IPADDR2_COPY(&sipaddr, &hdr->sipaddr);
+    IPADDR2_COPY(&dipaddr, &hdr->dipaddr);
+
+    if (netif->autoip->state == AUTOIP_STATE_PROBING) {
+     /* RFC 3927 Section 2.2.1:
+      * from beginning to after ANNOUNCE_WAIT
+      * seconds we have a conflict if
+      * ip.src == llipaddr OR
+      * ip.dst == llipaddr && hw.src != own hwaddr
+      */
+      if ((ip4_addr_cmp(&sipaddr, &netif->autoip->llipaddr)) ||
+          (ip4_addr_cmp(&dipaddr, &netif->autoip->llipaddr) &&
+           !eth_addr_cmp(&netifaddr, &hdr->shwaddr))) {
+        LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
+          ("autoip_arp_reply(): Probe Conflict detected\n"));
+        autoip_restart(netif);
+      }
+    } else {
+     /* RFC 3927 Section 2.5:
+      * in any state we have a conflict if
+      * ip.src == llipaddr && hw.src != own hwaddr
+      */
+      if (ip4_addr_cmp(&sipaddr, &netif->autoip->llipaddr) &&
+          !eth_addr_cmp(&netifaddr, &hdr->shwaddr)) {
+        LWIP_DEBUGF(AUTOIP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE | LWIP_DBG_LEVEL_WARNING,
+          ("autoip_arp_reply(): Conflicting ARP-Packet detected\n"));
+        autoip_handle_arp_conflict(netif);
+      }
+    }
+  }
+}
+
+/** check if AutoIP supplied netif->ip_addr
+ *
+ * @param netif the netif to check
+ * @return 1 if AutoIP supplied netif->ip_addr (state BOUND or ANNOUNCING),
+ *         0 otherwise
+ */
+u8_t
+autoip_supplied_address(const struct netif *netif)
+{
+  if ((netif != NULL) && (netif->autoip != NULL)) {
+    if ((netif->autoip->state == AUTOIP_STATE_BOUND) ||
+        (netif->autoip->state == AUTOIP_STATE_ANNOUNCING)) {
+      return 1;
+    }
+  }
+  return 0;
+}
+
+#endif /* LWIP_IPV4 && LWIP_AUTOIP */

ext/lwip/src/core/ipv4/icmp.c

@@ -0,0 +1,393 @@
+/**
+ * @file
+ * ICMP - Internet Control Message Protocol
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+/* Some ICMP messages should be passed to the transport protocols. This
+   is not implemented. */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV4 && LWIP_ICMP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/icmp.h"
+#include "lwip/inet_chksum.h"
+#include "lwip/ip.h"
+#include "lwip/def.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+/** Small optimization: set to 0 if incoming PBUF_POOL pbuf always can be
+ * used to modify and send a response packet (and to 1 if this is not the case,
+ * e.g. when link header is stripped of when receiving) */
+#ifndef LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
+#define LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN 1
+#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
+
+/* The amount of data from the original packet to return in a dest-unreachable */
+#define ICMP_DEST_UNREACH_DATASIZE 8
+
+static void icmp_send_response(struct pbuf *p, u8_t type, u8_t code);
+
+/**
+ * Processes ICMP input packets, called from ip_input().
+ *
+ * Currently only processes icmp echo requests and sends
+ * out the echo response.
+ *
+ * @param p the icmp echo request packet, p->payload pointing to the icmp header
+ * @param inp the netif on which this packet was received
+ */
+void
+icmp_input(struct pbuf *p, struct netif *inp)
+{
+  u8_t type;
+#ifdef LWIP_DEBUG
+  u8_t code;
+#endif /* LWIP_DEBUG */
+  struct icmp_echo_hdr *iecho;
+  const struct ip_hdr *iphdr_in;
+  s16_t hlen;
+  const ip4_addr_t* src;
+
+  ICMP_STATS_INC(icmp.recv);
+  MIB2_STATS_INC(mib2.icmpinmsgs);
+
+  iphdr_in = ip4_current_header();
+  hlen = IPH_HL(iphdr_in) * 4;
+  if (hlen < IP_HLEN) {
+    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short IP header (%"S16_F" bytes) received\n", hlen));
+    goto lenerr;
+  }
+  if (p->len < sizeof(u16_t)*2) {
+    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len));
+    goto lenerr;
+  }
+
+  type = *((u8_t *)p->payload);
+#ifdef LWIP_DEBUG
+  code = *(((u8_t *)p->payload)+1);
+#endif /* LWIP_DEBUG */
+  switch (type) {
+  case ICMP_ER:
+    /* This is OK, echo reply might have been parsed by a raw PCB
+       (as obviously, an echo request has been sent, too). */
+    MIB2_STATS_INC(mib2.icmpinechoreps);
+    break;
+  case ICMP_ECHO:
+    MIB2_STATS_INC(mib2.icmpinechos);
+    src = ip4_current_dest_addr();
+    /* multicast destination address? */
+    if (ip4_addr_ismulticast(ip4_current_dest_addr())) {
+#if LWIP_MULTICAST_PING
+      /* For multicast, use address of receiving interface as source address */
+      src = netif_ip4_addr(inp);
+#else /* LWIP_MULTICAST_PING */
+      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast pings\n"));
+      goto icmperr;
+#endif /* LWIP_MULTICAST_PING */
+    }
+    /* broadcast destination address? */
+    if (ip4_addr_isbroadcast(ip4_current_dest_addr(), ip_current_netif())) {
+#if LWIP_BROADCAST_PING
+      /* For broadcast, use address of receiving interface as source address */
+      src = netif_ip4_addr(inp);
+#else /* LWIP_BROADCAST_PING */
+      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to broadcast pings\n"));
+      goto icmperr;
+#endif /* LWIP_BROADCAST_PING */
+    }
+    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
+    if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
+      LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
+      goto lenerr;
+    }
+#if CHECKSUM_CHECK_ICMP
+    IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP) {
+      if (inet_chksum_pbuf(p) != 0) {
+        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
+        pbuf_free(p);
+        ICMP_STATS_INC(icmp.chkerr);
+        MIB2_STATS_INC(mib2.icmpinerrors);
+        return;
+      }
+    }
+#endif
+#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
+    if (pbuf_header(p, (hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
+      /* p is not big enough to contain link headers
+       * allocate a new one and copy p into it
+       */
+      struct pbuf *r;
+      /* allocate new packet buffer with space for link headers */
+      r = pbuf_alloc(PBUF_LINK, p->tot_len + hlen, PBUF_RAM);
+      if (r == NULL) {
+        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
+        goto icmperr;
+      }
+      if (r->len < hlen + sizeof(struct icmp_echo_hdr)) {
+        LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("first pbuf cannot hold the ICMP header"));
+        pbuf_free(r);
+        goto icmperr;
+      }
+      /* copy the ip header */
+      MEMCPY(r->payload, iphdr_in, hlen);
+      /* switch r->payload back to icmp header (cannot fail) */
+      if (pbuf_header(r, -hlen)) {
+        LWIP_ASSERT("icmp_input: moving r->payload to icmp header failed\n", 0);
+        pbuf_free(r);
+        goto icmperr;
+      }
+      /* copy the rest of the packet without ip header */
+      if (pbuf_copy(r, p) != ERR_OK) {
+        LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("icmp_input: copying to new pbuf failed"));
+        pbuf_free(r);
+        goto icmperr;
+      }
+      /* free the original p */
+      pbuf_free(p);
+      /* we now have an identical copy of p that has room for link headers */
+      p = r;
+    } else {
+      /* restore p->payload to point to icmp header (cannot fail) */
+      if (pbuf_header(p, -(s16_t)(hlen + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
+        LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
+        goto icmperr;
+      }
+    }
+#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
+    /* At this point, all checks are OK. */
+    /* We generate an answer by switching the dest and src ip addresses,
+     * setting the icmp type to ECHO_RESPONSE and updating the checksum. */
+    iecho = (struct icmp_echo_hdr *)p->payload;
+    if (pbuf_header(p, hlen)) {
+      LWIP_DEBUGF(ICMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Can't move over header in packet"));
+    } else {
+      err_t ret;
+      struct ip_hdr *iphdr = (struct ip_hdr*)p->payload;
+      ip4_addr_copy(iphdr->src, *src);
+      ip4_addr_copy(iphdr->dest, *ip4_current_src_addr());
+      ICMPH_TYPE_SET(iecho, ICMP_ER);
+#if CHECKSUM_GEN_ICMP
+      IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP) {
+        /* adjust the checksum */
+        if (iecho->chksum > PP_HTONS(0xffffU - (ICMP_ECHO << 8))) {
+          iecho->chksum += PP_HTONS(ICMP_ECHO << 8) + 1;
+        } else {
+          iecho->chksum += PP_HTONS(ICMP_ECHO << 8);
+        }
+      }
+#if LWIP_CHECKSUM_CTRL_PER_NETIF
+      else {
+        iecho->chksum = 0;
+      }
+#endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
+#else /* CHECKSUM_GEN_ICMP */
+      iecho->chksum = 0;
+#endif /* CHECKSUM_GEN_ICMP */
+
+      /* Set the correct TTL and recalculate the header checksum. */
+      IPH_TTL_SET(iphdr, ICMP_TTL);
+      IPH_CHKSUM_SET(iphdr, 0);
+#if CHECKSUM_GEN_IP
+      IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP) {
+        IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, hlen));
+      }
+#endif /* CHECKSUM_GEN_IP */
+
+      ICMP_STATS_INC(icmp.xmit);
+      /* increase number of messages attempted to send */
+      MIB2_STATS_INC(mib2.icmpoutmsgs);
+      /* increase number of echo replies attempted to send */
+      MIB2_STATS_INC(mib2.icmpoutechoreps);
+
+      /* send an ICMP packet */
+      ret = ip4_output_if(p, src, IP_HDRINCL,
+                   ICMP_TTL, 0, IP_PROTO_ICMP, inp);
+      if (ret != ERR_OK) {
+        LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %s\n", lwip_strerr(ret)));
+      }
+    }
+    break;
+  default:
+    if (type == ICMP_DUR) {
+      MIB2_STATS_INC(mib2.icmpindestunreachs);
+    } else if (type == ICMP_TE) {
+      MIB2_STATS_INC(mib2.icmpindestunreachs);
+    } else if (type == ICMP_PP) {
+      MIB2_STATS_INC(mib2.icmpinparmprobs);
+    } else if (type == ICMP_SQ) {
+      MIB2_STATS_INC(mib2.icmpinsrcquenchs);
+    } else if (type == ICMP_RD) {
+      MIB2_STATS_INC(mib2.icmpinredirects);
+    } else if (type == ICMP_TS) {
+      MIB2_STATS_INC(mib2.icmpintimestamps);
+    } else if (type == ICMP_TSR) {
+      MIB2_STATS_INC(mib2.icmpintimestampreps);
+    } else if (type == ICMP_AM) {
+      MIB2_STATS_INC(mib2.icmpinaddrmasks);
+    } else if (type == ICMP_AMR) {
+      MIB2_STATS_INC(mib2.icmpinaddrmaskreps);
+    }
+    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ICMP type %"S16_F" code %"S16_F" not supported.\n",
+                (s16_t)type, (s16_t)code));
+    ICMP_STATS_INC(icmp.proterr);
+    ICMP_STATS_INC(icmp.drop);
+  }
+  pbuf_free(p);
+  return;
+lenerr:
+  pbuf_free(p);
+  ICMP_STATS_INC(icmp.lenerr);
+  MIB2_STATS_INC(mib2.icmpinerrors);
+  return;
+#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING
+icmperr:
+  pbuf_free(p);
+  ICMP_STATS_INC(icmp.err);
+  MIB2_STATS_INC(mib2.icmpinerrors);
+  return;
+#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN || !LWIP_MULTICAST_PING || !LWIP_BROADCAST_PING */
+}
+
+/**
+ * Send an icmp 'destination unreachable' packet, called from ip_input() if
+ * the transport layer protocol is unknown and from udp_input() if the local
+ * port is not bound.
+ *
+ * @param p the input packet for which the 'unreachable' should be sent,
+ *          p->payload pointing to the IP header
+ * @param t type of the 'unreachable' packet
+ */
+void
+icmp_dest_unreach(struct pbuf *p, enum icmp_dur_type t)
+{
+  MIB2_STATS_INC(mib2.icmpoutdestunreachs);
+  icmp_send_response(p, ICMP_DUR, t);
+}
+
+#if IP_FORWARD || IP_REASSEMBLY
+/**
+ * Send a 'time exceeded' packet, called from ip_forward() if TTL is 0.
+ *
+ * @param p the input packet for which the 'time exceeded' should be sent,
+ *          p->payload pointing to the IP header
+ * @param t type of the 'time exceeded' packet
+ */
+void
+icmp_time_exceeded(struct pbuf *p, enum icmp_te_type t)
+{
+  MIB2_STATS_INC(mib2.icmpouttimeexcds);
+  icmp_send_response(p, ICMP_TE, t);
+}
+
+#endif /* IP_FORWARD || IP_REASSEMBLY */
+
+/**
+ * Send an icmp packet in response to an incoming packet.
+ *
+ * @param p the input packet for which the 'unreachable' should be sent,
+ *          p->payload pointing to the IP header
+ * @param type Type of the ICMP header
+ * @param code Code of the ICMP header
+ */
+static void
+icmp_send_response(struct pbuf *p, u8_t type, u8_t code)
+{
+  struct pbuf *q;
+  struct ip_hdr *iphdr;
+  /* we can use the echo header here */
+  struct icmp_echo_hdr *icmphdr;
+  ip4_addr_t iphdr_src;
+  struct netif *netif;
+
+  /* increase number of messages attempted to send */
+  MIB2_STATS_INC(mib2.icmpoutmsgs);
+
+  /* ICMP header + IP header + 8 bytes of data */
+  q = pbuf_alloc(PBUF_IP, sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE,
+                 PBUF_RAM);
+  if (q == NULL) {
+    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMP packet.\n"));
+    MIB2_STATS_INC(mib2.icmpouterrors);
+    return;
+  }
+  LWIP_ASSERT("check that first pbuf can hold icmp message",
+             (q->len >= (sizeof(struct icmp_echo_hdr) + IP_HLEN + ICMP_DEST_UNREACH_DATASIZE)));
+
+  iphdr = (struct ip_hdr *)p->payload;
+  LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded from "));
+  ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->src);
+  LWIP_DEBUGF(ICMP_DEBUG, (" to "));
+  ip4_addr_debug_print_val(ICMP_DEBUG, iphdr->dest);
+  LWIP_DEBUGF(ICMP_DEBUG, ("\n"));
+
+  icmphdr = (struct icmp_echo_hdr *)q->payload;
+  icmphdr->type = type;
+  icmphdr->code = code;
+  icmphdr->id = 0;
+  icmphdr->seqno = 0;
+
+  /* copy fields from original packet */
+  SMEMCPY((u8_t *)q->payload + sizeof(struct icmp_echo_hdr), (u8_t *)p->payload,
+          IP_HLEN + ICMP_DEST_UNREACH_DATASIZE);
+
+  ip4_addr_copy(iphdr_src, iphdr->src);
+#ifdef LWIP_HOOK_IP4_ROUTE_SRC
+  {
+    ip4_addr_t iphdr_dst;
+    ip4_addr_copy(iphdr_dst, iphdr->dest);
+    netif = ip4_route_src(&iphdr_src, &iphdr_dst);
+  }
+#else
+  netif = ip4_route(&iphdr_src);
+#endif
+  if (netif != NULL) {
+    /* calculate checksum */
+    icmphdr->chksum = 0;
+#if CHECKSUM_GEN_ICMP
+    IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP) {
+      icmphdr->chksum = inet_chksum(icmphdr, q->len);
+    }
+#endif
+    ICMP_STATS_INC(icmp.xmit);
+    ip4_output_if(q, NULL, &iphdr_src, ICMP_TTL, 0, IP_PROTO_ICMP, netif);
+  }
+  pbuf_free(q);
+}
+
+#endif /* LWIP_IPV4 && LWIP_ICMP */

ext/lwip/src/core/ipv4/igmp.c

@@ -0,0 +1,841 @@
+/**
+ * @file
+ * IGMP - Internet Group Management Protocol
+ *
+ */
+
+/*
+ * Copyright (c) 2002 CITEL Technologies Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of CITEL Technologies Ltd nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY CITEL TECHNOLOGIES AND CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL CITEL TECHNOLOGIES OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is a contribution to the lwIP TCP/IP stack.
+ * The Swedish Institute of Computer Science and Adam Dunkels
+ * are specifically granted permission to redistribute this
+ * source code.
+*/
+
+/**
+ * @defgroup igmp IGMP
+ * @ingroup ip4
+ * To be called from TCPIP thread
+ */
+
+/*-------------------------------------------------------------
+Note 1)
+Although the rfc requires V1 AND V2 capability
+we will only support v2 since now V1 is very old (August 1989)
+V1 can be added if required
+
+a debug print and statistic have been implemented to
+show this up.
+-------------------------------------------------------------
+-------------------------------------------------------------
+Note 2)
+A query for a specific group address (as opposed to ALLHOSTS)
+has now been implemented as I am unsure if it is required
+
+a debug print and statistic have been implemented to
+show this up.
+-------------------------------------------------------------
+-------------------------------------------------------------
+Note 3)
+The router alert rfc 2113 is implemented in outgoing packets
+but not checked rigorously incoming
+-------------------------------------------------------------
+Steve Reynolds
+------------------------------------------------------------*/
+
+/*-----------------------------------------------------------------------------
+ * RFC 988  - Host extensions for IP multicasting                         - V0
+ * RFC 1054 - Host extensions for IP multicasting                         -
+ * RFC 1112 - Host extensions for IP multicasting                         - V1
+ * RFC 2236 - Internet Group Management Protocol, Version 2               - V2  <- this code is based on this RFC (it's the "de facto" standard)
+ * RFC 3376 - Internet Group Management Protocol, Version 3               - V3
+ * RFC 4604 - Using Internet Group Management Protocol Version 3...       - V3+
+ * RFC 2113 - IP Router Alert Option                                      -
+ *----------------------------------------------------------------------------*/
+
+/*-----------------------------------------------------------------------------
+ * Includes
+ *----------------------------------------------------------------------------*/
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV4 && LWIP_IGMP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/igmp.h"
+#include "lwip/debug.h"
+#include "lwip/def.h"
+#include "lwip/mem.h"
+#include "lwip/ip.h"
+#include "lwip/inet_chksum.h"
+#include "lwip/netif.h"
+#include "lwip/stats.h"
+
+#include "string.h"
+
+/*
+ * IGMP constants
+ */
+#define IGMP_TTL                       1
+#define IGMP_MINLEN                    8
+#define ROUTER_ALERT                   0x9404U
+#define ROUTER_ALERTLEN                4
+
+/*
+ * IGMP message types, including version number.
+ */
+#define IGMP_MEMB_QUERY                0x11 /* Membership query         */
+#define IGMP_V1_MEMB_REPORT            0x12 /* Ver. 1 membership report */
+#define IGMP_V2_MEMB_REPORT            0x16 /* Ver. 2 membership report */
+#define IGMP_LEAVE_GROUP               0x17 /* Leave-group message      */
+
+/* Group  membership states */
+#define IGMP_GROUP_NON_MEMBER          0
+#define IGMP_GROUP_DELAYING_MEMBER     1
+#define IGMP_GROUP_IDLE_MEMBER         2
+
+/**
+ * IGMP packet format.
+ */
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct igmp_msg {
+  PACK_STRUCT_FLD_8(u8_t         igmp_msgtype);
+  PACK_STRUCT_FLD_8(u8_t         igmp_maxresp);
+  PACK_STRUCT_FIELD(u16_t        igmp_checksum);
+  PACK_STRUCT_FLD_S(ip4_addr_p_t igmp_group_address);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+
+
+static struct igmp_group *igmp_lookup_group(struct netif *ifp, const ip4_addr_t *addr);
+static err_t  igmp_remove_group(struct igmp_group *group);
+static void   igmp_timeout( struct igmp_group *group);
+static void   igmp_start_timer(struct igmp_group *group, u8_t max_time);
+static void   igmp_delaying_member(struct igmp_group *group, u8_t maxresp);
+static err_t  igmp_ip_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, struct netif *netif);
+static void   igmp_send(struct igmp_group *group, u8_t type);
+
+
+static struct igmp_group* igmp_group_list;
+static ip4_addr_t     allsystems;
+static ip4_addr_t     allrouters;
+
+
+/**
+ * Initialize the IGMP module
+ */
+void
+igmp_init(void)
+{
+  LWIP_DEBUGF(IGMP_DEBUG, ("igmp_init: initializing\n"));
+
+  IP4_ADDR(&allsystems, 224, 0, 0, 1);
+  IP4_ADDR(&allrouters, 224, 0, 0, 2);
+}
+
+/**
+ * Start IGMP processing on interface
+ *
+ * @param netif network interface on which start IGMP processing
+ */
+err_t
+igmp_start(struct netif *netif)
+{
+  struct igmp_group* group;
+
+  LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: starting IGMP processing on if %p\n", (void*)netif));
+
+  group = igmp_lookup_group(netif, &allsystems);
+
+  if (group != NULL) {
+    group->group_state = IGMP_GROUP_IDLE_MEMBER;
+    group->use++;
+
+    /* Allow the igmp messages at the MAC level */
+    if (netif->igmp_mac_filter != NULL) {
+      LWIP_DEBUGF(IGMP_DEBUG, ("igmp_start: igmp_mac_filter(ADD "));
+      ip4_addr_debug_print_val(IGMP_DEBUG, allsystems);
+      LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void*)netif));
+      netif->igmp_mac_filter(netif, &allsystems, IGMP_ADD_MAC_FILTER);
+    }
+
+    return ERR_OK;
+  }
+
+  return ERR_MEM;
+}
+
+/**
+ * Stop IGMP processing on interface
+ *
+ * @param netif network interface on which stop IGMP processing
+ */
+err_t
+igmp_stop(struct netif *netif)
+{
+  struct igmp_group *group = igmp_group_list;
+  struct igmp_group *prev  = NULL;
+  struct igmp_group *next;
+
+  /* look for groups joined on this interface further down the list */
+  while (group != NULL) {
+    next = group->next;
+    /* is it a group joined on this interface? */
+    if (group->netif == netif) {
+      /* is it the first group of the list? */
+      if (group == igmp_group_list) {
+        igmp_group_list = next;
+      }
+      /* is there a "previous" group defined? */
+      if (prev != NULL) {
+        prev->next = next;
+      }
+      /* disable the group at the MAC level */
+      if (netif->igmp_mac_filter != NULL) {
+        LWIP_DEBUGF(IGMP_DEBUG, ("igmp_stop: igmp_mac_filter(DEL "));
+        ip4_addr_debug_print(IGMP_DEBUG, &group->group_address);
+        LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void*)netif));
+        netif->igmp_mac_filter(netif, &(group->group_address), IGMP_DEL_MAC_FILTER);
+      }
+      /* free group */
+      memp_free(MEMP_IGMP_GROUP, group);
+    } else {
+      /* change the "previous" */
+      prev = group;
+    }
+    /* move to "next" */
+    group = next;
+  }
+  return ERR_OK;
+}
+
+/**
+ * Report IGMP memberships for this interface
+ *
+ * @param netif network interface on which report IGMP memberships
+ */
+void
+igmp_report_groups(struct netif *netif)
+{
+  struct igmp_group *group = igmp_group_list;
+
+  LWIP_DEBUGF(IGMP_DEBUG, ("igmp_report_groups: sending IGMP reports on if %p\n", (void*)netif));
+
+  while (group != NULL) {
+    if ((group->netif == netif) && (!(ip4_addr_cmp(&(group->group_address), &allsystems)))) {
+      igmp_delaying_member(group, IGMP_JOIN_DELAYING_MEMBER_TMR);
+    }
+    group = group->next;
+  }
+}
+
+/**
+ * Search for a group in the global igmp_group_list
+ *
+ * @param ifp the network interface for which to look
+ * @param addr the group ip address to search for
+ * @return a struct igmp_group* if the group has been found,
+ *         NULL if the group wasn't found.
+ */
+struct igmp_group *
+igmp_lookfor_group(struct netif *ifp, const ip4_addr_t *addr)
+{
+  struct igmp_group *group = igmp_group_list;
+
+  while (group != NULL) {
+    if ((group->netif == ifp) && (ip4_addr_cmp(&(group->group_address), addr))) {
+      return group;
+    }
+    group = group->next;
+  }
+
+  /* to be clearer, we return NULL here instead of
+   * 'group' (which is also NULL at this point).
+   */
+  return NULL;
+}
+
+/**
+ * Search for a specific igmp group and create a new one if not found-
+ *
+ * @param ifp the network interface for which to look
+ * @param addr the group ip address to search
+ * @return a struct igmp_group*,
+ *         NULL on memory error.
+ */
+struct igmp_group *
+igmp_lookup_group(struct netif *ifp, const ip4_addr_t *addr)
+{
+  struct igmp_group *group;
+
+  /* Search if the group already exists */
+  group = igmp_lookfor_group(ifp, addr);
+  if (group != NULL) {
+    /* Group already exists. */
+    return group;
+  }
+
+  /* Group doesn't exist yet, create a new one */
+  group = (struct igmp_group *)memp_malloc(MEMP_IGMP_GROUP);
+  if (group != NULL) {
+    group->netif              = ifp;
+    ip4_addr_set(&(group->group_address), addr);
+    group->timer              = 0; /* Not running */
+    group->group_state        = IGMP_GROUP_NON_MEMBER;
+    group->last_reporter_flag = 0;
+    group->use                = 0;
+    group->next               = igmp_group_list;
+
+    igmp_group_list = group;
+  }
+
+  LWIP_DEBUGF(IGMP_DEBUG, ("igmp_lookup_group: %sallocated a new group with address ", (group?"":"impossible to ")));
+  ip4_addr_debug_print(IGMP_DEBUG, addr);
+  LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void*)ifp));
+
+  return group;
+}
+
+/**
+ * Remove a group in the global igmp_group_list
+ *
+ * @param group the group to remove from the global igmp_group_list
+ * @return ERR_OK if group was removed from the list, an err_t otherwise
+ */
+static err_t
+igmp_remove_group(struct igmp_group *group)
+{
+  err_t err = ERR_OK;
+
+  /* Is it the first group? */
+  if (igmp_group_list == group) {
+    igmp_group_list = group->next;
+  } else {
+    /* look for group further down the list */
+    struct igmp_group *tmpGroup;
+    for (tmpGroup = igmp_group_list; tmpGroup != NULL; tmpGroup = tmpGroup->next) {
+      if (tmpGroup->next == group) {
+        tmpGroup->next = group->next;
+        break;
+      }
+    }
+    /* Group not found in the global igmp_group_list */
+    if (tmpGroup == NULL) {
+      err = ERR_ARG;
+    }
+  }
+  /* free group */
+  memp_free(MEMP_IGMP_GROUP, group);
+
+  return err;
+}
+
+/**
+ * Called from ip_input() if a new IGMP packet is received.
+ *
+ * @param p received igmp packet, p->payload pointing to the igmp header
+ * @param inp network interface on which the packet was received
+ * @param dest destination ip address of the igmp packet
+ */
+void
+igmp_input(struct pbuf *p, struct netif *inp, const ip4_addr_t *dest)
+{
+  struct igmp_msg*   igmp;
+  struct igmp_group* group;
+  struct igmp_group* groupref;
+
+  IGMP_STATS_INC(igmp.recv);
+
+  /* Note that the length CAN be greater than 8 but only 8 are used - All are included in the checksum */
+  if (p->len < IGMP_MINLEN) {
+    pbuf_free(p);
+    IGMP_STATS_INC(igmp.lenerr);
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: length error\n"));
+    return;
+  }
+
+  LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: message from "));
+  ip4_addr_debug_print(IGMP_DEBUG, &(ip4_current_header()->src));
+  LWIP_DEBUGF(IGMP_DEBUG, (" to address "));
+  ip4_addr_debug_print(IGMP_DEBUG, &(ip4_current_header()->dest));
+  LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void*)inp));
+
+  /* Now calculate and check the checksum */
+  igmp = (struct igmp_msg *)p->payload;
+  if (inet_chksum(igmp, p->len)) {
+    pbuf_free(p);
+    IGMP_STATS_INC(igmp.chkerr);
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: checksum error\n"));
+    return;
+  }
+
+  /* Packet is ok so find an existing group */
+  group = igmp_lookfor_group(inp, dest); /* use the destination IP address of incoming packet */
+
+  /* If group can be found or create... */
+  if (!group) {
+    pbuf_free(p);
+    IGMP_STATS_INC(igmp.drop);
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP frame not for us\n"));
+    return;
+  }
+
+  /* NOW ACT ON THE INCOMING MESSAGE TYPE... */
+  switch (igmp->igmp_msgtype) {
+  case IGMP_MEMB_QUERY:
+    /* IGMP_MEMB_QUERY to the "all systems" address ? */
+    if ((ip4_addr_cmp(dest, &allsystems)) && ip4_addr_isany(&igmp->igmp_group_address)) {
+      /* THIS IS THE GENERAL QUERY */
+      LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: General IGMP_MEMB_QUERY on \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
+
+      if (igmp->igmp_maxresp == 0) {
+        IGMP_STATS_INC(igmp.rx_v1);
+        LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: got an all hosts query with time== 0 - this is V1 and not implemented - treat as v2\n"));
+        igmp->igmp_maxresp = IGMP_V1_DELAYING_MEMBER_TMR;
+      } else {
+        IGMP_STATS_INC(igmp.rx_general);
+      }
+
+      groupref = igmp_group_list;
+      while (groupref) {
+        /* Do not send messages on the all systems group address! */
+        if ((groupref->netif == inp) && (!(ip4_addr_cmp(&(groupref->group_address), &allsystems)))) {
+          igmp_delaying_member(groupref, igmp->igmp_maxresp);
+        }
+        groupref = groupref->next;
+      }
+    } else {
+      /* IGMP_MEMB_QUERY to a specific group ? */
+      if (!ip4_addr_isany(&igmp->igmp_group_address)) {
+        LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_MEMB_QUERY to a specific group "));
+        ip4_addr_debug_print(IGMP_DEBUG, &igmp->igmp_group_address);
+        if (ip4_addr_cmp(dest, &allsystems)) {
+          ip4_addr_t groupaddr;
+          LWIP_DEBUGF(IGMP_DEBUG, (" using \"ALL SYSTEMS\" address (224.0.0.1) [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
+          /* we first need to re-look for the group since we used dest last time */
+          ip4_addr_copy(groupaddr, igmp->igmp_group_address);
+          group = igmp_lookfor_group(inp, &groupaddr);
+        } else {
+          LWIP_DEBUGF(IGMP_DEBUG, (" with the group address as destination [igmp_maxresp=%i]\n", (int)(igmp->igmp_maxresp)));
+        }
+
+        if (group != NULL) {
+          IGMP_STATS_INC(igmp.rx_group);
+          igmp_delaying_member(group, igmp->igmp_maxresp);
+        } else {
+          IGMP_STATS_INC(igmp.drop);
+        }
+      } else {
+        IGMP_STATS_INC(igmp.proterr);
+      }
+    }
+    break;
+  case IGMP_V2_MEMB_REPORT:
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: IGMP_V2_MEMB_REPORT\n"));
+    IGMP_STATS_INC(igmp.rx_report);
+    if (group->group_state == IGMP_GROUP_DELAYING_MEMBER) {
+      /* This is on a specific group we have already looked up */
+      group->timer = 0; /* stopped */
+      group->group_state = IGMP_GROUP_IDLE_MEMBER;
+      group->last_reporter_flag = 0;
+    }
+    break;
+  default:
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_input: unexpected msg %d in state %d on group %p on if %p\n",
+      igmp->igmp_msgtype, group->group_state, (void*)&group, (void*)group->netif));
+    IGMP_STATS_INC(igmp.proterr);
+    break;
+  }
+
+  pbuf_free(p);
+  return;
+}
+
+/**
+ * @ingroup igmp
+ * Join a group on one network interface.
+ *
+ * @param ifaddr ip address of the network interface which should join a new group
+ * @param groupaddr the ip address of the group which to join
+ * @return ERR_OK if group was joined on the netif(s), an err_t otherwise
+ */
+err_t
+igmp_joingroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr)
+{
+  err_t err = ERR_VAL; /* no matching interface */
+  struct netif *netif;
+
+  /* make sure it is multicast address */
+  LWIP_ERROR("igmp_joingroup: attempt to join non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;);
+  LWIP_ERROR("igmp_joingroup: attempt to join allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;);
+
+  /* loop through netif's */
+  netif = netif_list;
+  while (netif != NULL) {
+    /* Should we join this interface ? */
+    if ((netif->flags & NETIF_FLAG_IGMP) && ((ip4_addr_isany(ifaddr) || ip4_addr_cmp(netif_ip4_addr(netif), ifaddr)))) {
+      err = igmp_joingroup_netif(netif, groupaddr);
+      if (err != ERR_OK) {
+        /* Return an error even if some network interfaces are joined */
+        /** @todo undo any other netif already joined */
+        return err;
+      }
+    }
+    /* proceed to next network interface */
+    netif = netif->next;
+  }
+
+  return err;
+}
+
+/**
+ * @ingroup igmp
+ * Join a group on one network interface.
+ *
+ * @param netif the network interface which should join a new group
+ * @param groupaddr the ip address of the group which to join
+ * @return ERR_OK if group was joined on the netif, an err_t otherwise
+ */
+err_t
+igmp_joingroup_netif(struct netif *netif, const ip4_addr_t *groupaddr)
+{
+  struct igmp_group *group;
+
+  /* make sure it is multicast address */
+  LWIP_ERROR("igmp_joingroup_netif: attempt to join non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;);
+  LWIP_ERROR("igmp_joingroup_netif: attempt to join allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;);
+
+  /* make sure it is an igmp-enabled netif */
+  LWIP_ERROR("igmp_joingroup_netif: attempt to join on non-IGMP netif", netif->flags & NETIF_FLAG_IGMP, return ERR_VAL;);
+
+  /* find group or create a new one if not found */
+  group = igmp_lookup_group(netif, groupaddr);
+
+  if (group != NULL) {
+    /* This should create a new group, check the state to make sure */
+    if (group->group_state != IGMP_GROUP_NON_MEMBER) {
+      LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: join to group not in state IGMP_GROUP_NON_MEMBER\n"));
+    } else {
+      /* OK - it was new group */
+      LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: join to new group: "));
+      ip4_addr_debug_print(IGMP_DEBUG, groupaddr);
+      LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
+
+      /* If first use of the group, allow the group at the MAC level */
+      if ((group->use==0) && (netif->igmp_mac_filter != NULL)) {
+        LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: igmp_mac_filter(ADD "));
+        ip4_addr_debug_print(IGMP_DEBUG, groupaddr);
+        LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void*)netif));
+        netif->igmp_mac_filter(netif, groupaddr, IGMP_ADD_MAC_FILTER);
+      }
+
+      IGMP_STATS_INC(igmp.tx_join);
+      igmp_send(group, IGMP_V2_MEMB_REPORT);
+
+      igmp_start_timer(group, IGMP_JOIN_DELAYING_MEMBER_TMR);
+
+      /* Need to work out where this timer comes from */
+      group->group_state = IGMP_GROUP_DELAYING_MEMBER;
+    }
+    /* Increment group use */
+    group->use++;
+    /* Join on this interface */
+    return ERR_OK;
+  } else {
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_joingroup_netif: Not enough memory to join to group\n"));
+    return ERR_MEM;
+  }
+}
+
+/**
+ * @ingroup igmp
+ * Leave a group on one network interface.
+ *
+ * @param ifaddr ip address of the network interface which should leave a group
+ * @param groupaddr the ip address of the group which to leave
+ * @return ERR_OK if group was left on the netif(s), an err_t otherwise
+ */
+err_t
+igmp_leavegroup(const ip4_addr_t *ifaddr, const ip4_addr_t *groupaddr)
+{
+  err_t err = ERR_VAL; /* no matching interface */
+  struct netif *netif;
+
+  /* make sure it is multicast address */
+  LWIP_ERROR("igmp_leavegroup: attempt to leave non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;);
+  LWIP_ERROR("igmp_leavegroup: attempt to leave allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;);
+
+  /* loop through netif's */
+  netif = netif_list;
+  while (netif != NULL) {
+    /* Should we leave this interface ? */
+    if ((netif->flags & NETIF_FLAG_IGMP) && ((ip4_addr_isany(ifaddr) || ip4_addr_cmp(netif_ip4_addr(netif), ifaddr)))) {
+      err_t res = igmp_leavegroup_netif(netif, groupaddr);
+      if (err != ERR_OK) {
+        /* Store this result if we have not yet gotten a success */
+        err = res;
+      }
+    }
+    /* proceed to next network interface */
+    netif = netif->next;
+  }
+
+  return err;
+}
+
+/**
+ * @ingroup igmp
+ * Leave a group on one network interface.
+ *
+ * @param netif the network interface which should leave a group
+ * @param groupaddr the ip address of the group which to leave
+ * @return ERR_OK if group was left on the netif, an err_t otherwise
+ */
+err_t
+igmp_leavegroup_netif(struct netif *netif, const ip4_addr_t *groupaddr)
+{
+  struct igmp_group *group;
+
+  /* make sure it is multicast address */
+  LWIP_ERROR("igmp_leavegroup_netif: attempt to leave non-multicast address", ip4_addr_ismulticast(groupaddr), return ERR_VAL;);
+  LWIP_ERROR("igmp_leavegroup_netif: attempt to leave allsystems address", (!ip4_addr_cmp(groupaddr, &allsystems)), return ERR_VAL;);
+
+  /* make sure it is an igmp-enabled netif */
+  LWIP_ERROR("igmp_leavegroup_netif: attempt to leave on non-IGMP netif", netif->flags & NETIF_FLAG_IGMP, return ERR_VAL;);
+
+  /* find group */
+  group = igmp_lookfor_group(netif, groupaddr);
+
+  if (group != NULL) {
+    /* Only send a leave if the flag is set according to the state diagram */
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: Leaving group: "));
+    ip4_addr_debug_print(IGMP_DEBUG, groupaddr);
+    LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
+
+    /* If there is no other use of the group */
+    if (group->use <= 1) {
+      /* If we are the last reporter for this group */
+      if (group->last_reporter_flag) {
+        LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: sending leaving group\n"));
+        IGMP_STATS_INC(igmp.tx_leave);
+        igmp_send(group, IGMP_LEAVE_GROUP);
+      }
+
+      /* Disable the group at the MAC level */
+      if (netif->igmp_mac_filter != NULL) {
+        LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: igmp_mac_filter(DEL "));
+        ip4_addr_debug_print(IGMP_DEBUG, groupaddr);
+        LWIP_DEBUGF(IGMP_DEBUG, (") on if %p\n", (void*)netif));
+        netif->igmp_mac_filter(netif, groupaddr, IGMP_DEL_MAC_FILTER);
+      }
+
+      LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: remove group: "));
+      ip4_addr_debug_print(IGMP_DEBUG, groupaddr);
+      LWIP_DEBUGF(IGMP_DEBUG, ("\n"));
+
+      /* Free the group */
+      igmp_remove_group(group);
+    } else {
+      /* Decrement group use */
+      group->use--;
+    }
+    return ERR_OK;
+  } else {
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_leavegroup_netif: not member of group\n"));
+    return ERR_VAL;
+  }
+}
+
+/**
+ * The igmp timer function (both for NO_SYS=1 and =0)
+ * Should be called every IGMP_TMR_INTERVAL milliseconds (100 ms is default).
+ */
+void
+igmp_tmr(void)
+{
+  struct igmp_group *group = igmp_group_list;
+
+  while (group != NULL) {
+    if (group->timer > 0) {
+      group->timer--;
+      if (group->timer == 0) {
+        igmp_timeout(group);
+      }
+    }
+    group = group->next;
+  }
+}
+
+/**
+ * Called if a timeout for one group is reached.
+ * Sends a report for this group.
+ *
+ * @param group an igmp_group for which a timeout is reached
+ */
+static void
+igmp_timeout(struct igmp_group *group)
+{
+  /* If the state is IGMP_GROUP_DELAYING_MEMBER then we send a report for this group
+     (unless it is the allsystems group) */
+  if ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) &&
+      (!(ip4_addr_cmp(&(group->group_address), &allsystems)))) {
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_timeout: report membership for group with address "));
+    ip4_addr_debug_print(IGMP_DEBUG, &(group->group_address));
+    LWIP_DEBUGF(IGMP_DEBUG, (" on if %p\n", (void*)group->netif));
+
+    IGMP_STATS_INC(igmp.tx_report);
+    igmp_send(group, IGMP_V2_MEMB_REPORT);
+  }
+}
+
+/**
+ * Start a timer for an igmp group
+ *
+ * @param group the igmp_group for which to start a timer
+ * @param max_time the time in multiples of IGMP_TMR_INTERVAL (decrease with
+ *        every call to igmp_tmr())
+ */
+static void
+igmp_start_timer(struct igmp_group *group, u8_t max_time)
+{
+#ifdef LWIP_RAND
+  group->timer = max_time > 2 ? (LWIP_RAND() % max_time) : 1;
+#else /* LWIP_RAND */
+  /* ATTENTION: use this only if absolutely necessary! */
+  group->timer = max_time / 2;
+#endif /* LWIP_RAND */
+
+  if (group->timer == 0) {
+    group->timer = 1;
+  }
+}
+
+/**
+ * Delaying membership report for a group if necessary
+ *
+ * @param group the igmp_group for which "delaying" membership report
+ * @param maxresp query delay
+ */
+static void
+igmp_delaying_member(struct igmp_group *group, u8_t maxresp)
+{
+  if ((group->group_state == IGMP_GROUP_IDLE_MEMBER) ||
+     ((group->group_state == IGMP_GROUP_DELAYING_MEMBER) &&
+      ((group->timer == 0) || (maxresp < group->timer)))) {
+    igmp_start_timer(group, maxresp);
+    group->group_state = IGMP_GROUP_DELAYING_MEMBER;
+  }
+}
+
+
+/**
+ * Sends an IP packet on a network interface. This function constructs the IP header
+ * and calculates the IP header checksum. If the source IP address is NULL,
+ * the IP address of the outgoing network interface is filled in as source address.
+ *
+ * @param p the packet to send (p->payload points to the data, e.g. next
+            protocol header; if dest == IP_HDRINCL, p already includes an IP
+            header and p->payload points to that IP header)
+ * @param src the source IP address to send from (if src == IP_ADDR_ANY, the
+ *         IP  address of the netif used to send is used as source address)
+ * @param dest the destination IP address to send the packet to
+ * @param ttl the TTL value to be set in the IP header
+ * @param proto the PROTOCOL to be set in the IP header
+ * @param netif the netif on which to send this packet
+ * @return ERR_OK if the packet was sent OK
+ *         ERR_BUF if p doesn't have enough space for IP/LINK headers
+ *         returns errors returned by netif->output
+ */
+static err_t
+igmp_ip_output_if(struct pbuf *p, const ip4_addr_t *src, const ip4_addr_t *dest, struct netif *netif)
+{
+  /* This is the "router alert" option */
+  u16_t ra[2];
+  ra[0] = PP_HTONS(ROUTER_ALERT);
+  ra[1] = 0x0000; /* Router shall examine packet */
+  IGMP_STATS_INC(igmp.xmit);
+  return ip4_output_if_opt(p, src, dest, IGMP_TTL, 0, IP_PROTO_IGMP, netif, ra, ROUTER_ALERTLEN);
+}
+
+/**
+ * Send an igmp packet to a specific group.
+ *
+ * @param group the group to which to send the packet
+ * @param type the type of igmp packet to send
+ */
+static void
+igmp_send(struct igmp_group *group, u8_t type)
+{
+  struct pbuf*     p    = NULL;
+  struct igmp_msg* igmp = NULL;
+  ip4_addr_t   src  = *IP4_ADDR_ANY;
+  ip4_addr_t*  dest = NULL;
+
+  /* IP header + "router alert" option + IGMP header */
+  p = pbuf_alloc(PBUF_TRANSPORT, IGMP_MINLEN, PBUF_RAM);
+
+  if (p) {
+    igmp = (struct igmp_msg *)p->payload;
+    LWIP_ASSERT("igmp_send: check that first pbuf can hold struct igmp_msg",
+               (p->len >= sizeof(struct igmp_msg)));
+    ip4_addr_copy(src, *netif_ip4_addr(group->netif));
+
+    if (type == IGMP_V2_MEMB_REPORT) {
+      dest = &(group->group_address);
+      ip4_addr_copy(igmp->igmp_group_address, group->group_address);
+      group->last_reporter_flag = 1; /* Remember we were the last to report */
+    } else {
+      if (type == IGMP_LEAVE_GROUP) {
+        dest = &allrouters;
+        ip4_addr_copy(igmp->igmp_group_address, group->group_address);
+      }
+    }
+
+    if ((type == IGMP_V2_MEMB_REPORT) || (type == IGMP_LEAVE_GROUP)) {
+      igmp->igmp_msgtype  = type;
+      igmp->igmp_maxresp  = 0;
+      igmp->igmp_checksum = 0;
+      igmp->igmp_checksum = inet_chksum(igmp, IGMP_MINLEN);
+
+      igmp_ip_output_if(p, &src, dest, group->netif);
+    }
+
+    pbuf_free(p);
+  } else {
+    LWIP_DEBUGF(IGMP_DEBUG, ("igmp_send: not enough memory for igmp_send\n"));
+    IGMP_STATS_INC(igmp.memerr);
+  }
+}
+
+#endif /* LWIP_IPV4 && LWIP_IGMP */

ext/lwip/src/core/ipv4/ip4_addr.c

@@ -0,0 +1,331 @@
+/**
+ * @file
+ * This is the IPv4 address tools implementation.
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV4
+
+#include "lwip/ip_addr.h"
+#include "lwip/netif.h"
+
+/* used by IP_ADDR_ANY and IP_ADDR_BROADCAST in ip_addr.h */
+const ip_addr_t ip_addr_any = IPADDR4_INIT(IPADDR_ANY);
+const ip_addr_t ip_addr_broadcast = IPADDR4_INIT(IPADDR_BROADCAST);
+
+/**
+ * Determine if an address is a broadcast address on a network interface
+ *
+ * @param addr address to be checked
+ * @param netif the network interface against which the address is checked
+ * @return returns non-zero if the address is a broadcast address
+ */
+u8_t
+ip4_addr_isbroadcast_u32(u32_t addr, const struct netif *netif)
+{
+  ip4_addr_t ipaddr;
+  ip4_addr_set_u32(&ipaddr, addr);
+
+  /* all ones (broadcast) or all zeroes (old skool broadcast) */
+  if ((~addr == IPADDR_ANY) ||
+      (addr == IPADDR_ANY)) {
+    return 1;
+  /* no broadcast support on this network interface? */
+  } else if ((netif->flags & NETIF_FLAG_BROADCAST) == 0) {
+    /* the given address cannot be a broadcast address
+     * nor can we check against any broadcast addresses */
+    return 0;
+  /* address matches network interface address exactly? => no broadcast */
+  } else if (addr == ip4_addr_get_u32(netif_ip4_addr(netif))) {
+    return 0;
+  /*  on the same (sub) network... */
+  } else if (ip4_addr_netcmp(&ipaddr, netif_ip4_addr(netif), netif_ip4_netmask(netif))
+         /* ...and host identifier bits are all ones? =>... */
+          && ((addr & ~ip4_addr_get_u32(netif_ip4_netmask(netif))) ==
+           (IPADDR_BROADCAST & ~ip4_addr_get_u32(netif_ip4_netmask(netif))))) {
+    /* => network broadcast address */
+    return 1;
+  } else {
+    return 0;
+  }
+}
+
+/** Checks if a netmask is valid (starting with ones, then only zeros)
+ *
+ * @param netmask the IPv4 netmask to check (in network byte order!)
+ * @return 1 if the netmask is valid, 0 if it is not
+ */
+u8_t
+ip4_addr_netmask_valid(u32_t netmask)
+{
+  u32_t mask;
+  u32_t nm_hostorder = lwip_htonl(netmask);
+
+  /* first, check for the first zero */
+  for (mask = 1UL << 31 ; mask != 0; mask >>= 1) {
+    if ((nm_hostorder & mask) == 0) {
+      break;
+    }
+  }
+  /* then check that there is no one */
+  for (; mask != 0; mask >>= 1) {
+    if ((nm_hostorder & mask) != 0) {
+      /* there is a one after the first zero -> invalid */
+      return 0;
+    }
+  }
+  /* no one after the first zero -> valid */
+  return 1;
+}
+
+/* Here for now until needed in other places in lwIP */
+#ifndef isprint
+#define in_range(c, lo, up)  ((u8_t)c >= lo && (u8_t)c <= up)
+#define isprint(c)           in_range(c, 0x20, 0x7f)
+#define isdigit(c)           in_range(c, '0', '9')
+#define isxdigit(c)          (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F'))
+#define islower(c)           in_range(c, 'a', 'z')
+#define isspace(c)           (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
+#endif
+
+/**
+ * Ascii internet address interpretation routine.
+ * The value returned is in network order.
+ *
+ * @param cp IP address in ascii representation (e.g. "127.0.0.1")
+ * @return ip address in network order
+ */
+u32_t
+ipaddr_addr(const char *cp)
+{
+  ip4_addr_t val;
+
+  if (ip4addr_aton(cp, &val)) {
+    return ip4_addr_get_u32(&val);
+  }
+  return (IPADDR_NONE);
+}
+
+/**
+ * Check whether "cp" is a valid ascii representation
+ * of an Internet address and convert to a binary address.
+ * Returns 1 if the address is valid, 0 if not.
+ * This replaces inet_addr, the return value from which
+ * cannot distinguish between failure and a local broadcast address.
+ *
+ * @param cp IP address in ascii representation (e.g. "127.0.0.1")
+ * @param addr pointer to which to save the ip address in network order
+ * @return 1 if cp could be converted to addr, 0 on failure
+ */
+int
+ip4addr_aton(const char *cp, ip4_addr_t *addr)
+{
+  u32_t val;
+  u8_t base;
+  char c;
+  u32_t parts[4];
+  u32_t *pp = parts;
+
+  c = *cp;
+  for (;;) {
+    /*
+     * Collect number up to ``.''.
+     * Values are specified as for C:
+     * 0x=hex, 0=octal, 1-9=decimal.
+     */
+    if (!isdigit(c)) {
+      return 0;
+    }
+    val = 0;
+    base = 10;
+    if (c == '0') {
+      c = *++cp;
+      if (c == 'x' || c == 'X') {
+        base = 16;
+        c = *++cp;
+      } else {
+        base = 8;
+      }
+    }
+    for (;;) {
+      if (isdigit(c)) {
+        val = (val * base) + (int)(c - '0');
+        c = *++cp;
+      } else if (base == 16 && isxdigit(c)) {
+        val = (val << 4) | (int)(c + 10 - (islower(c) ? 'a' : 'A'));
+        c = *++cp;
+      } else {
+        break;
+      }
+    }
+    if (c == '.') {
+      /*
+       * Internet format:
+       *  a.b.c.d
+       *  a.b.c   (with c treated as 16 bits)
+       *  a.b (with b treated as 24 bits)
+       */
+      if (pp >= parts + 3) {
+        return 0;
+      }
+      *pp++ = val;
+      c = *++cp;
+    } else {
+      break;
+    }
+  }
+  /*
+   * Check for trailing characters.
+   */
+  if (c != '\0' && !isspace(c)) {
+    return 0;
+  }
+  /*
+   * Concoct the address according to
+   * the number of parts specified.
+   */
+  switch (pp - parts + 1) {
+
+  case 0:
+    return 0;       /* initial nondigit */
+
+  case 1:             /* a -- 32 bits */
+    break;
+
+  case 2:             /* a.b -- 8.24 bits */
+    if (val > 0xffffffUL) {
+      return 0;
+    }
+    if (parts[0] > 0xff) {
+      return 0;
+    }
+    val |= parts[0] << 24;
+    break;
+
+  case 3:             /* a.b.c -- 8.8.16 bits */
+    if (val > 0xffff) {
+      return 0;
+    }
+    if ((parts[0] > 0xff) || (parts[1] > 0xff)) {
+      return 0;
+    }
+    val |= (parts[0] << 24) | (parts[1] << 16);
+    break;
+
+  case 4:             /* a.b.c.d -- 8.8.8.8 bits */
+    if (val > 0xff) {
+      return 0;
+    }
+    if ((parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff)) {
+      return 0;
+    }
+    val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
+    break;
+  default:
+    LWIP_ASSERT("unhandled", 0);
+    break;
+  }
+  if (addr) {
+    ip4_addr_set_u32(addr, htonl(val));
+  }
+  return 1;
+}
+
+/**
+ * Convert numeric IP address into decimal dotted ASCII representation.
+ * returns ptr to static buffer; not reentrant!
+ *
+ * @param addr ip address in network order to convert
+ * @return pointer to a global static (!) buffer that holds the ASCII
+ *         representation of addr
+ */
+char*
+ip4addr_ntoa(const ip4_addr_t *addr)
+{
+  static char str[IP4ADDR_STRLEN_MAX];
+  return ip4addr_ntoa_r(addr, str, IP4ADDR_STRLEN_MAX);
+}
+
+/**
+ * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
+ *
+ * @param addr ip address in network order to convert
+ * @param buf target buffer where the string is stored
+ * @param buflen length of buf
+ * @return either pointer to buf which now holds the ASCII
+ *         representation of addr or NULL if buf was too small
+ */
+char*
+ip4addr_ntoa_r(const ip4_addr_t *addr, char *buf, int buflen)
+{
+  u32_t s_addr;
+  char inv[3];
+  char *rp;
+  u8_t *ap;
+  u8_t rem;
+  u8_t n;
+  u8_t i;
+  int len = 0;
+
+  s_addr = ip4_addr_get_u32(addr);
+
+  rp = buf;
+  ap = (u8_t *)&s_addr;
+  for (n = 0; n < 4; n++) {
+    i = 0;
+    do {
+      rem = *ap % (u8_t)10;
+      *ap /= (u8_t)10;
+      inv[i++] = '0' + rem;
+    } while (*ap);
+    while (i--) {
+      if (len++ >= buflen) {
+        return NULL;
+      }
+      *rp++ = inv[i];
+    }
+    if (len++ >= buflen) {
+      return NULL;
+    }
+    *rp++ = '.';
+    ap++;
+  }
+  *--rp = 0;
+  return buf;
+}
+
+#endif /* LWIP_IPV4 */

ext/lwip/src/core/ipv4/ip4_frag.c

@@ -0,0 +1,897 @@
+/**
+ * @file
+ * This is the IPv4 packet segmentation and reassembly implementation.
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Jani Monoses <jani@iv.ro>
+ *         Simon Goldschmidt
+ * original reassembly code by Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV4
+
+#include "lwip/ip4_frag.h"
+#include "lwip/def.h"
+#include "lwip/inet_chksum.h"
+#include "lwip/netif.h"
+#include "lwip/stats.h"
+#include "lwip/icmp.h"
+
+#include <string.h>
+
+#if IP_REASSEMBLY
+/**
+ * The IP reassembly code currently has the following limitations:
+ * - IP header options are not supported
+ * - fragments must not overlap (e.g. due to different routes),
+ *   currently, overlapping or duplicate fragments are thrown away
+ *   if IP_REASS_CHECK_OVERLAP=1 (the default)!
+ *
+ * @todo: work with IP header options
+ */
+
+/** Setting this to 0, you can turn off checking the fragments for overlapping
+ * regions. The code gets a little smaller. Only use this if you know that
+ * overlapping won't occur on your network! */
+#ifndef IP_REASS_CHECK_OVERLAP
+#define IP_REASS_CHECK_OVERLAP 1
+#endif /* IP_REASS_CHECK_OVERLAP */
+
+/** Set to 0 to prevent freeing the oldest datagram when the reassembly buffer is
+ * full (IP_REASS_MAX_PBUFS pbufs are enqueued). The code gets a little smaller.
+ * Datagrams will be freed by timeout only. Especially useful when MEMP_NUM_REASSDATA
+ * is set to 1, so one datagram can be reassembled at a time, only. */
+#ifndef IP_REASS_FREE_OLDEST
+#define IP_REASS_FREE_OLDEST 1
+#endif /* IP_REASS_FREE_OLDEST */
+
+#define IP_REASS_FLAG_LASTFRAG 0x01
+
+/** This is a helper struct which holds the starting
+ * offset and the ending offset of this fragment to
+ * easily chain the fragments.
+ * It has the same packing requirements as the IP header, since it replaces
+ * the IP header in memory in incoming fragments (after copying it) to keep
+ * track of the various fragments. (-> If the IP header doesn't need packing,
+ * this struct doesn't need packing, too.)
+ */
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct ip_reass_helper {
+  PACK_STRUCT_FIELD(struct pbuf *next_pbuf);
+  PACK_STRUCT_FIELD(u16_t start);
+  PACK_STRUCT_FIELD(u16_t end);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+
+#define IP_ADDRESSES_AND_ID_MATCH(iphdrA, iphdrB)  \
+  (ip4_addr_cmp(&(iphdrA)->src, &(iphdrB)->src) && \
+   ip4_addr_cmp(&(iphdrA)->dest, &(iphdrB)->dest) && \
+   IPH_ID(iphdrA) == IPH_ID(iphdrB)) ? 1 : 0
+
+/* global variables */
+static struct ip_reassdata *reassdatagrams;
+static u16_t ip_reass_pbufcount;
+
+/* function prototypes */
+static void ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
+static int ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev);
+
+/**
+ * Reassembly timer base function
+ * for both NO_SYS == 0 and 1 (!).
+ *
+ * Should be called every 1000 msec (defined by IP_TMR_INTERVAL).
+ */
+void
+ip_reass_tmr(void)
+{
+  struct ip_reassdata *r, *prev = NULL;
+
+  r = reassdatagrams;
+  while (r != NULL) {
+    /* Decrement the timer. Once it reaches 0,
+     * clean up the incomplete fragment assembly */
+    if (r->timer > 0) {
+      r->timer--;
+      LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer dec %"U16_F"\n",(u16_t)r->timer));
+      prev = r;
+      r = r->next;
+    } else {
+      /* reassembly timed out */
+      struct ip_reassdata *tmp;
+      LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_reass_tmr: timer timed out\n"));
+      tmp = r;
+      /* get the next pointer before freeing */
+      r = r->next;
+      /* free the helper struct and all enqueued pbufs */
+      ip_reass_free_complete_datagram(tmp, prev);
+     }
+   }
+}
+
+/**
+ * Free a datagram (struct ip_reassdata) and all its pbufs.
+ * Updates the total count of enqueued pbufs (ip_reass_pbufcount),
+ * SNMP counters and sends an ICMP time exceeded packet.
+ *
+ * @param ipr datagram to free
+ * @param prev the previous datagram in the linked list
+ * @return the number of pbufs freed
+ */
+static int
+ip_reass_free_complete_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
+{
+  u16_t pbufs_freed = 0;
+  u8_t clen;
+  struct pbuf *p;
+  struct ip_reass_helper *iprh;
+
+  LWIP_ASSERT("prev != ipr", prev != ipr);
+  if (prev != NULL) {
+    LWIP_ASSERT("prev->next == ipr", prev->next == ipr);
+  }
+
+  MIB2_STATS_INC(mib2.ipreasmfails);
+#if LWIP_ICMP
+  iprh = (struct ip_reass_helper *)ipr->p->payload;
+  if (iprh->start == 0) {
+    /* The first fragment was received, send ICMP time exceeded. */
+    /* First, de-queue the first pbuf from r->p. */
+    p = ipr->p;
+    ipr->p = iprh->next_pbuf;
+    /* Then, copy the original header into it. */
+    SMEMCPY(p->payload, &ipr->iphdr, IP_HLEN);
+    icmp_time_exceeded(p, ICMP_TE_FRAG);
+    clen = pbuf_clen(p);
+    LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
+    pbufs_freed += clen;
+    pbuf_free(p);
+  }
+#endif /* LWIP_ICMP */
+
+  /* First, free all received pbufs.  The individual pbufs need to be released
+     separately as they have not yet been chained */
+  p = ipr->p;
+  while (p != NULL) {
+    struct pbuf *pcur;
+    iprh = (struct ip_reass_helper *)p->payload;
+    pcur = p;
+    /* get the next pointer before freeing */
+    p = iprh->next_pbuf;
+    clen = pbuf_clen(pcur);
+    LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
+    pbufs_freed += clen;
+    pbuf_free(pcur);
+  }
+  /* Then, unchain the struct ip_reassdata from the list and free it. */
+  ip_reass_dequeue_datagram(ipr, prev);
+  LWIP_ASSERT("ip_reass_pbufcount >= clen", ip_reass_pbufcount >= pbufs_freed);
+  ip_reass_pbufcount -= pbufs_freed;
+
+  return pbufs_freed;
+}
+
+#if IP_REASS_FREE_OLDEST
+/**
+ * Free the oldest datagram to make room for enqueueing new fragments.
+ * The datagram 'fraghdr' belongs to is not freed!
+ *
+ * @param fraghdr IP header of the current fragment
+ * @param pbufs_needed number of pbufs needed to enqueue
+ *        (used for freeing other datagrams if not enough space)
+ * @return the number of pbufs freed
+ */
+static int
+ip_reass_remove_oldest_datagram(struct ip_hdr *fraghdr, int pbufs_needed)
+{
+  /* @todo Can't we simply remove the last datagram in the
+   *       linked list behind reassdatagrams?
+   */
+  struct ip_reassdata *r, *oldest, *prev, *oldest_prev;
+  int pbufs_freed = 0, pbufs_freed_current;
+  int other_datagrams;
+
+  /* Free datagrams until being allowed to enqueue 'pbufs_needed' pbufs,
+   * but don't free the datagram that 'fraghdr' belongs to! */
+  do {
+    oldest = NULL;
+    prev = NULL;
+    oldest_prev = NULL;
+    other_datagrams = 0;
+    r = reassdatagrams;
+    while (r != NULL) {
+      if (!IP_ADDRESSES_AND_ID_MATCH(&r->iphdr, fraghdr)) {
+        /* Not the same datagram as fraghdr */
+        other_datagrams++;
+        if (oldest == NULL) {
+          oldest = r;
+          oldest_prev = prev;
+        } else if (r->timer <= oldest->timer) {
+          /* older than the previous oldest */
+          oldest = r;
+          oldest_prev = prev;
+        }
+      }
+      if (r->next != NULL) {
+        prev = r;
+      }
+      r = r->next;
+    }
+    if (oldest != NULL) {
+      pbufs_freed_current = ip_reass_free_complete_datagram(oldest, oldest_prev);
+      pbufs_freed += pbufs_freed_current;
+    }
+  } while ((pbufs_freed < pbufs_needed) && (other_datagrams > 1));
+  return pbufs_freed;
+}
+#endif /* IP_REASS_FREE_OLDEST */
+
+/**
+ * Enqueues a new fragment into the fragment queue
+ * @param fraghdr points to the new fragments IP hdr
+ * @param clen number of pbufs needed to enqueue (used for freeing other datagrams if not enough space)
+ * @return A pointer to the queue location into which the fragment was enqueued
+ */
+static struct ip_reassdata*
+ip_reass_enqueue_new_datagram(struct ip_hdr *fraghdr, int clen)
+{
+  struct ip_reassdata* ipr;
+#if ! IP_REASS_FREE_OLDEST
+  LWIP_UNUSED_ARG(clen);
+#endif
+
+  /* No matching previous fragment found, allocate a new reassdata struct */
+  ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
+  if (ipr == NULL) {
+#if IP_REASS_FREE_OLDEST
+    if (ip_reass_remove_oldest_datagram(fraghdr, clen) >= clen) {
+      ipr = (struct ip_reassdata *)memp_malloc(MEMP_REASSDATA);
+    }
+    if (ipr == NULL)
+#endif /* IP_REASS_FREE_OLDEST */
+    {
+      IPFRAG_STATS_INC(ip_frag.memerr);
+      LWIP_DEBUGF(IP_REASS_DEBUG,("Failed to alloc reassdata struct\n"));
+      return NULL;
+    }
+  }
+  memset(ipr, 0, sizeof(struct ip_reassdata));
+  ipr->timer = IP_REASS_MAXAGE;
+
+  /* enqueue the new structure to the front of the list */
+  ipr->next = reassdatagrams;
+  reassdatagrams = ipr;
+  /* copy the ip header for later tests and input */
+  /* @todo: no ip options supported? */
+  SMEMCPY(&(ipr->iphdr), fraghdr, IP_HLEN);
+  return ipr;
+}
+
+/**
+ * Dequeues a datagram from the datagram queue. Doesn't deallocate the pbufs.
+ * @param ipr points to the queue entry to dequeue
+ */
+static void
+ip_reass_dequeue_datagram(struct ip_reassdata *ipr, struct ip_reassdata *prev)
+{
+  /* dequeue the reass struct  */
+  if (reassdatagrams == ipr) {
+    /* it was the first in the list */
+    reassdatagrams = ipr->next;
+  } else {
+    /* it wasn't the first, so it must have a valid 'prev' */
+    LWIP_ASSERT("sanity check linked list", prev != NULL);
+    prev->next = ipr->next;
+  }
+
+  /* now we can free the ip_reassdata struct */
+  memp_free(MEMP_REASSDATA, ipr);
+}
+
+/**
+ * Chain a new pbuf into the pbuf list that composes the datagram.  The pbuf list
+ * will grow over time as  new pbufs are rx.
+ * Also checks that the datagram passes basic continuity checks (if the last
+ * fragment was received at least once).
+ * @param root_p points to the 'root' pbuf for the current datagram being assembled.
+ * @param new_p points to the pbuf for the current fragment
+ * @return 0 if invalid, >0 otherwise
+ */
+static int
+ip_reass_chain_frag_into_datagram_and_validate(struct ip_reassdata *ipr, struct pbuf *new_p)
+{
+  struct ip_reass_helper *iprh, *iprh_tmp, *iprh_prev=NULL;
+  struct pbuf *q;
+  u16_t offset,len;
+  struct ip_hdr *fraghdr;
+  int valid = 1;
+
+  /* Extract length and fragment offset from current fragment */
+  fraghdr = (struct ip_hdr*)new_p->payload;
+  len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
+  offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
+
+  /* overwrite the fragment's ip header from the pbuf with our helper struct,
+   * and setup the embedded helper structure. */
+  /* make sure the struct ip_reass_helper fits into the IP header */
+  LWIP_ASSERT("sizeof(struct ip_reass_helper) <= IP_HLEN",
+              sizeof(struct ip_reass_helper) <= IP_HLEN);
+  iprh = (struct ip_reass_helper*)new_p->payload;
+  iprh->next_pbuf = NULL;
+  iprh->start = offset;
+  iprh->end = offset + len;
+
+  /* Iterate through until we either get to the end of the list (append),
+   * or we find one with a larger offset (insert). */
+  for (q = ipr->p; q != NULL;) {
+    iprh_tmp = (struct ip_reass_helper*)q->payload;
+    if (iprh->start < iprh_tmp->start) {
+      /* the new pbuf should be inserted before this */
+      iprh->next_pbuf = q;
+      if (iprh_prev != NULL) {
+        /* not the fragment with the lowest offset */
+#if IP_REASS_CHECK_OVERLAP
+        if ((iprh->start < iprh_prev->end) || (iprh->end > iprh_tmp->start)) {
+          /* fragment overlaps with previous or following, throw away */
+          goto freepbuf;
+        }
+#endif /* IP_REASS_CHECK_OVERLAP */
+        iprh_prev->next_pbuf = new_p;
+      } else {
+        /* fragment with the lowest offset */
+        ipr->p = new_p;
+      }
+      break;
+    } else if (iprh->start == iprh_tmp->start) {
+      /* received the same datagram twice: no need to keep the datagram */
+      goto freepbuf;
+#if IP_REASS_CHECK_OVERLAP
+    } else if (iprh->start < iprh_tmp->end) {
+      /* overlap: no need to keep the new datagram */
+      goto freepbuf;
+#endif /* IP_REASS_CHECK_OVERLAP */
+    } else {
+      /* Check if the fragments received so far have no holes. */
+      if (iprh_prev != NULL) {
+        if (iprh_prev->end != iprh_tmp->start) {
+          /* There is a fragment missing between the current
+           * and the previous fragment */
+          valid = 0;
+        }
+      }
+    }
+    q = iprh_tmp->next_pbuf;
+    iprh_prev = iprh_tmp;
+  }
+
+  /* If q is NULL, then we made it to the end of the list. Determine what to do now */
+  if (q == NULL) {
+    if (iprh_prev != NULL) {
+      /* this is (for now), the fragment with the highest offset:
+       * chain it to the last fragment */
+#if IP_REASS_CHECK_OVERLAP
+      LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start);
+#endif /* IP_REASS_CHECK_OVERLAP */
+      iprh_prev->next_pbuf = new_p;
+      if (iprh_prev->end != iprh->start) {
+        valid = 0;
+      }
+    } else {
+#if IP_REASS_CHECK_OVERLAP
+      LWIP_ASSERT("no previous fragment, this must be the first fragment!",
+        ipr->p == NULL);
+#endif /* IP_REASS_CHECK_OVERLAP */
+      /* this is the first fragment we ever received for this ip datagram */
+      ipr->p = new_p;
+    }
+  }
+
+  /* At this point, the validation part begins: */
+  /* If we already received the last fragment */
+  if ((ipr->flags & IP_REASS_FLAG_LASTFRAG) != 0) {
+    /* and had no holes so far */
+    if (valid) {
+      /* then check if the rest of the fragments is here */
+      /* Check if the queue starts with the first datagram */
+      if ((ipr->p == NULL) || (((struct ip_reass_helper*)ipr->p->payload)->start != 0)) {
+        valid = 0;
+      } else {
+        /* and check that there are no holes after this datagram */
+        iprh_prev = iprh;
+        q = iprh->next_pbuf;
+        while (q != NULL) {
+          iprh = (struct ip_reass_helper*)q->payload;
+          if (iprh_prev->end != iprh->start) {
+            valid = 0;
+            break;
+          }
+          iprh_prev = iprh;
+          q = iprh->next_pbuf;
+        }
+        /* if still valid, all fragments are received
+         * (because to the MF==0 already arrived */
+        if (valid) {
+          LWIP_ASSERT("sanity check", ipr->p != NULL);
+          LWIP_ASSERT("sanity check",
+            ((struct ip_reass_helper*)ipr->p->payload) != iprh);
+          LWIP_ASSERT("validate_datagram:next_pbuf!=NULL",
+            iprh->next_pbuf == NULL);
+          LWIP_ASSERT("validate_datagram:datagram end!=datagram len",
+            iprh->end == ipr->datagram_len);
+        }
+      }
+    }
+    /* If valid is 0 here, there are some fragments missing in the middle
+     * (since MF == 0 has already arrived). Such datagrams simply time out if
+     * no more fragments are received... */
+    return valid;
+  }
+  /* If we come here, not all fragments were received, yet! */
+  return 0; /* not yet valid! */
+#if IP_REASS_CHECK_OVERLAP
+freepbuf:
+  ip_reass_pbufcount -= pbuf_clen(new_p);
+  pbuf_free(new_p);
+  return 0;
+#endif /* IP_REASS_CHECK_OVERLAP */
+}
+
+/**
+ * Reassembles incoming IP fragments into an IP datagram.
+ *
+ * @param p points to a pbuf chain of the fragment
+ * @return NULL if reassembly is incomplete, ? otherwise
+ */
+struct pbuf *
+ip4_reass(struct pbuf *p)
+{
+  struct pbuf *r;
+  struct ip_hdr *fraghdr;
+  struct ip_reassdata *ipr;
+  struct ip_reass_helper *iprh;
+  u16_t offset, len;
+  u8_t clen;
+
+  IPFRAG_STATS_INC(ip_frag.recv);
+  MIB2_STATS_INC(mib2.ipreasmreqds);
+
+  fraghdr = (struct ip_hdr*)p->payload;
+
+  if ((IPH_HL(fraghdr) * 4) != IP_HLEN) {
+    LWIP_DEBUGF(IP_REASS_DEBUG,("ip4_reass: IP options currently not supported!\n"));
+    IPFRAG_STATS_INC(ip_frag.err);
+    goto nullreturn;
+  }
+
+  offset = (ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) * 8;
+  len = ntohs(IPH_LEN(fraghdr)) - IPH_HL(fraghdr) * 4;
+
+  /* Check if we are allowed to enqueue more datagrams. */
+  clen = pbuf_clen(p);
+  if ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
+#if IP_REASS_FREE_OLDEST
+    if (!ip_reass_remove_oldest_datagram(fraghdr, clen) ||
+        ((ip_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS))
+#endif /* IP_REASS_FREE_OLDEST */
+    {
+      /* No datagram could be freed and still too many pbufs enqueued */
+      LWIP_DEBUGF(IP_REASS_DEBUG,("ip4_reass: Overflow condition: pbufct=%d, clen=%d, MAX=%d\n",
+        ip_reass_pbufcount, clen, IP_REASS_MAX_PBUFS));
+      IPFRAG_STATS_INC(ip_frag.memerr);
+      /* @todo: send ICMP time exceeded here? */
+      /* drop this pbuf */
+      goto nullreturn;
+    }
+  }
+
+  /* Look for the datagram the fragment belongs to in the current datagram queue,
+   * remembering the previous in the queue for later dequeueing. */
+  for (ipr = reassdatagrams; ipr != NULL; ipr = ipr->next) {
+    /* Check if the incoming fragment matches the one currently present
+       in the reassembly buffer. If so, we proceed with copying the
+       fragment into the buffer. */
+    if (IP_ADDRESSES_AND_ID_MATCH(&ipr->iphdr, fraghdr)) {
+      LWIP_DEBUGF(IP_REASS_DEBUG, ("ip4_reass: matching previous fragment ID=%"X16_F"\n",
+        ntohs(IPH_ID(fraghdr))));
+      IPFRAG_STATS_INC(ip_frag.cachehit);
+      break;
+    }
+  }
+
+  if (ipr == NULL) {
+  /* Enqueue a new datagram into the datagram queue */
+    ipr = ip_reass_enqueue_new_datagram(fraghdr, clen);
+    /* Bail if unable to enqueue */
+    if (ipr == NULL) {
+      goto nullreturn;
+    }
+  } else {
+    if (((ntohs(IPH_OFFSET(fraghdr)) & IP_OFFMASK) == 0) &&
+      ((ntohs(IPH_OFFSET(&ipr->iphdr)) & IP_OFFMASK) != 0)) {
+      /* ipr->iphdr is not the header from the first fragment, but fraghdr is
+       * -> copy fraghdr into ipr->iphdr since we want to have the header
+       * of the first fragment (for ICMP time exceeded and later, for copying
+       * all options, if supported)*/
+      SMEMCPY(&ipr->iphdr, fraghdr, IP_HLEN);
+    }
+  }
+  /* Track the current number of pbufs current 'in-flight', in order to limit
+  the number of fragments that may be enqueued at any one time */
+  ip_reass_pbufcount += clen;
+
+  /* At this point, we have either created a new entry or pointing
+   * to an existing one */
+
+  /* check for 'no more fragments', and update queue entry*/
+  if ((IPH_OFFSET(fraghdr) & PP_NTOHS(IP_MF)) == 0) {
+    ipr->flags |= IP_REASS_FLAG_LASTFRAG;
+    ipr->datagram_len = offset + len;
+    LWIP_DEBUGF(IP_REASS_DEBUG,
+     ("ip4_reass: last fragment seen, total len %"S16_F"\n",
+      ipr->datagram_len));
+  }
+  /* find the right place to insert this pbuf */
+  /* @todo: trim pbufs if fragments are overlapping */
+  if (ip_reass_chain_frag_into_datagram_and_validate(ipr, p)) {
+    struct ip_reassdata *ipr_prev;
+    /* the totally last fragment (flag more fragments = 0) was received at least
+     * once AND all fragments are received */
+    ipr->datagram_len += IP_HLEN;
+
+    /* save the second pbuf before copying the header over the pointer */
+    r = ((struct ip_reass_helper*)ipr->p->payload)->next_pbuf;
+
+    /* copy the original ip header back to the first pbuf */
+    fraghdr = (struct ip_hdr*)(ipr->p->payload);
+    SMEMCPY(fraghdr, &ipr->iphdr, IP_HLEN);
+    IPH_LEN_SET(fraghdr, htons(ipr->datagram_len));
+    IPH_OFFSET_SET(fraghdr, 0);
+    IPH_CHKSUM_SET(fraghdr, 0);
+    /* @todo: do we need to set/calculate the correct checksum? */
+#if CHECKSUM_GEN_IP
+    IF__NETIF_CHECKSUM_ENABLED(ip_current_input_netif(), NETIF_CHECKSUM_GEN_IP) {
+      IPH_CHKSUM_SET(fraghdr, inet_chksum(fraghdr, IP_HLEN));
+    }
+#endif /* CHECKSUM_GEN_IP */
+
+    p = ipr->p;
+
+    /* chain together the pbufs contained within the reass_data list. */
+    while (r != NULL) {
+      iprh = (struct ip_reass_helper*)r->payload;
+
+      /* hide the ip header for every succeeding fragment */
+      pbuf_header(r, -IP_HLEN);
+      pbuf_cat(p, r);
+      r = iprh->next_pbuf;
+    }
+
+    /* find the previous entry in the linked list */
+    if (ipr == reassdatagrams) {
+      ipr_prev = NULL;
+    } else {
+      for (ipr_prev = reassdatagrams; ipr_prev != NULL; ipr_prev = ipr_prev->next) {
+        if (ipr_prev->next == ipr) {
+          break;
+        }
+      }
+    }
+
+    /* release the sources allocate for the fragment queue entry */
+    ip_reass_dequeue_datagram(ipr, ipr_prev);
+
+    /* and adjust the number of pbufs currently queued for reassembly. */
+    ip_reass_pbufcount -= pbuf_clen(p);
+
+    MIB2_STATS_INC(mib2.ipreasmoks);
+
+    /* Return the pbuf chain */
+    return p;
+  }
+  /* the datagram is not (yet?) reassembled completely */
+  LWIP_DEBUGF(IP_REASS_DEBUG,("ip_reass_pbufcount: %d out\n", ip_reass_pbufcount));
+  return NULL;
+
+nullreturn:
+  LWIP_DEBUGF(IP_REASS_DEBUG,("ip4_reass: nullreturn\n"));
+  IPFRAG_STATS_INC(ip_frag.drop);
+  pbuf_free(p);
+  return NULL;
+}
+#endif /* IP_REASSEMBLY */
+
+#if IP_FRAG
+#if IP_FRAG_USES_STATIC_BUF
+static LWIP_DECLARE_MEMORY_ALIGNED(buf, IP_FRAG_MAX_MTU);
+#else /* IP_FRAG_USES_STATIC_BUF */
+
+#if !LWIP_NETIF_TX_SINGLE_PBUF
+/** Allocate a new struct pbuf_custom_ref */
+static struct pbuf_custom_ref*
+ip_frag_alloc_pbuf_custom_ref(void)
+{
+  return (struct pbuf_custom_ref*)memp_malloc(MEMP_FRAG_PBUF);
+}
+
+/** Free a struct pbuf_custom_ref */
+static void
+ip_frag_free_pbuf_custom_ref(struct pbuf_custom_ref* p)
+{
+  LWIP_ASSERT("p != NULL", p != NULL);
+  memp_free(MEMP_FRAG_PBUF, p);
+}
+
+/** Free-callback function to free a 'struct pbuf_custom_ref', called by
+ * pbuf_free. */
+static void
+ipfrag_free_pbuf_custom(struct pbuf *p)
+{
+  struct pbuf_custom_ref *pcr = (struct pbuf_custom_ref*)p;
+  LWIP_ASSERT("pcr != NULL", pcr != NULL);
+  LWIP_ASSERT("pcr == p", (void*)pcr == (void*)p);
+  if (pcr->original != NULL) {
+    pbuf_free(pcr->original);
+  }
+  ip_frag_free_pbuf_custom_ref(pcr);
+}
+#endif /* !LWIP_NETIF_TX_SINGLE_PBUF */
+#endif /* IP_FRAG_USES_STATIC_BUF */
+
+/**
+ * Fragment an IP datagram if too large for the netif.
+ *
+ * Chop the datagram in MTU sized chunks and send them in order
+ * by using a fixed size static memory buffer (PBUF_REF) or
+ * point PBUF_REFs into p (depending on IP_FRAG_USES_STATIC_BUF).
+ *
+ * @param p ip packet to send
+ * @param netif the netif on which to send
+ * @param dest destination ip address to which to send
+ *
+ * @return ERR_OK if sent successfully, err_t otherwise
+ */
+err_t
+ip4_frag(struct pbuf *p, struct netif *netif, const ip4_addr_t *dest)
+{
+  struct pbuf *rambuf;
+#if IP_FRAG_USES_STATIC_BUF
+  struct pbuf *header;
+#else
+#if !LWIP_NETIF_TX_SINGLE_PBUF
+  struct pbuf *newpbuf;
+#endif
+  struct ip_hdr *original_iphdr;
+#endif
+  struct ip_hdr *iphdr;
+  u16_t nfb;
+  u16_t left, cop;
+  u16_t mtu = netif->mtu;
+  u16_t ofo, omf;
+  u16_t last;
+  u16_t poff = IP_HLEN;
+  u16_t tmp;
+#if !IP_FRAG_USES_STATIC_BUF && !LWIP_NETIF_TX_SINGLE_PBUF
+  u16_t newpbuflen = 0;
+  u16_t left_to_copy;
+#endif
+
+  /* Get a RAM based MTU sized pbuf */
+#if IP_FRAG_USES_STATIC_BUF
+  /* When using a static buffer, we use a PBUF_REF, which we will
+   * use to reference the packet (without link header).
+   * Layer and length is irrelevant.
+   */
+  rambuf = pbuf_alloc(PBUF_LINK, 0, PBUF_REF);
+  if (rambuf == NULL) {
+    LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc(PBUF_LINK, 0, PBUF_REF) failed\n"));
+    goto memerr;
+  }
+  rambuf->tot_len = rambuf->len = mtu;
+  rambuf->payload = LWIP_MEM_ALIGN((void *)buf);
+
+  /* Copy the IP header in it */
+  iphdr = (struct ip_hdr *)rambuf->payload;
+  SMEMCPY(iphdr, p->payload, IP_HLEN);
+#else /* IP_FRAG_USES_STATIC_BUF */
+  original_iphdr = (struct ip_hdr *)p->payload;
+  iphdr = original_iphdr;
+#endif /* IP_FRAG_USES_STATIC_BUF */
+
+  /* Save original offset */
+  tmp = ntohs(IPH_OFFSET(iphdr));
+  ofo = tmp & IP_OFFMASK;
+  omf = tmp & IP_MF;
+
+  left = p->tot_len - IP_HLEN;
+
+  nfb = (mtu - IP_HLEN) / 8;
+
+  while (left) {
+    last = (left <= mtu - IP_HLEN);
+
+    /* Set new offset and MF flag */
+    tmp = omf | (IP_OFFMASK & (ofo));
+    if (!last) {
+      tmp = tmp | IP_MF;
+    }
+
+    /* Fill this fragment */
+    cop = last ? left : nfb * 8;
+
+#if IP_FRAG_USES_STATIC_BUF
+    poff += pbuf_copy_partial(p, (u8_t*)iphdr + IP_HLEN, cop, poff);
+#else /* IP_FRAG_USES_STATIC_BUF */
+#if LWIP_NETIF_TX_SINGLE_PBUF
+    rambuf = pbuf_alloc(PBUF_IP, cop, PBUF_RAM);
+    if (rambuf == NULL) {
+      goto memerr;
+    }
+    LWIP_ASSERT("this needs a pbuf in one piece!",
+      (rambuf->len == rambuf->tot_len) && (rambuf->next == NULL));
+    poff += pbuf_copy_partial(p, rambuf->payload, cop, poff);
+    /* make room for the IP header */
+    if (pbuf_header(rambuf, IP_HLEN)) {
+      pbuf_free(rambuf);
+      goto memerr;
+    }
+    /* fill in the IP header */
+    SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
+    iphdr = (struct ip_hdr*)rambuf->payload;
+#else /* LWIP_NETIF_TX_SINGLE_PBUF */
+    /* When not using a static buffer, create a chain of pbufs.
+     * The first will be a PBUF_RAM holding the link and IP header.
+     * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged,
+     * but limited to the size of an mtu.
+     */
+    rambuf = pbuf_alloc(PBUF_LINK, IP_HLEN, PBUF_RAM);
+    if (rambuf == NULL) {
+      goto memerr;
+    }
+    LWIP_ASSERT("this needs a pbuf in one piece!",
+                (p->len >= (IP_HLEN)));
+    SMEMCPY(rambuf->payload, original_iphdr, IP_HLEN);
+    iphdr = (struct ip_hdr *)rambuf->payload;
+
+    /* Can just adjust p directly for needed offset. */
+    p->payload = (u8_t *)p->payload + poff;
+    p->len -= poff;
+
+    left_to_copy = cop;
+    while (left_to_copy) {
+      struct pbuf_custom_ref *pcr;
+      newpbuflen = (left_to_copy < p->len) ? left_to_copy : p->len;
+      /* Is this pbuf already empty? */
+      if (!newpbuflen) {
+        p = p->next;
+        continue;
+      }
+      pcr = ip_frag_alloc_pbuf_custom_ref();
+      if (pcr == NULL) {
+        pbuf_free(rambuf);
+        goto memerr;
+      }
+      /* Mirror this pbuf, although we might not need all of it. */
+      newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, p->payload, newpbuflen);
+      if (newpbuf == NULL) {
+        ip_frag_free_pbuf_custom_ref(pcr);
+        pbuf_free(rambuf);
+        goto memerr;
+      }
+      pbuf_ref(p);
+      pcr->original = p;
+      pcr->pc.custom_free_function = ipfrag_free_pbuf_custom;
+
+      /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain
+       * so that it is removed when pbuf_dechain is later called on rambuf.
+       */
+      pbuf_cat(rambuf, newpbuf);
+      left_to_copy -= newpbuflen;
+      if (left_to_copy) {
+        p = p->next;
+      }
+    }
+    poff = newpbuflen;
+#endif /* LWIP_NETIF_TX_SINGLE_PBUF */
+#endif /* IP_FRAG_USES_STATIC_BUF */
+
+    /* Correct header */
+    IPH_OFFSET_SET(iphdr, htons(tmp));
+    IPH_LEN_SET(iphdr, htons(cop + IP_HLEN));
+    IPH_CHKSUM_SET(iphdr, 0);
+#if CHECKSUM_GEN_IP
+    IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_IP) {
+      IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
+    }
+#endif /* CHECKSUM_GEN_IP */
+
+#if IP_FRAG_USES_STATIC_BUF
+    if (last) {
+      pbuf_realloc(rambuf, left + IP_HLEN);
+    }
+
+    /* This part is ugly: we alloc a RAM based pbuf for
+     * the link level header for each chunk and then
+     * free it. A PBUF_ROM style pbuf for which pbuf_header
+     * worked would make things simpler.
+     */
+    header = pbuf_alloc(PBUF_LINK, 0, PBUF_RAM);
+    if (header != NULL) {
+      pbuf_chain(header, rambuf);
+      netif->output(netif, header, dest);
+      IPFRAG_STATS_INC(ip_frag.xmit);
+      MIB2_STATS_INC(mib2.ipfragcreates);
+      pbuf_free(header);
+    } else {
+      LWIP_DEBUGF(IP_REASS_DEBUG, ("ip_frag: pbuf_alloc() for header failed\n"));
+      pbuf_free(rambuf);
+      goto memerr;
+    }
+#else /* IP_FRAG_USES_STATIC_BUF */
+    /* No need for separate header pbuf - we allowed room for it in rambuf
+     * when allocated.
+     */
+    netif->output(netif, rambuf, dest);
+    IPFRAG_STATS_INC(ip_frag.xmit);
+
+    /* Unfortunately we can't reuse rambuf - the hardware may still be
+     * using the buffer. Instead we free it (and the ensuing chain) and
+     * recreate it next time round the loop. If we're lucky the hardware
+     * will have already sent the packet, the free will really free, and
+     * there will be zero memory penalty.
+     */
+
+    pbuf_free(rambuf);
+#endif /* IP_FRAG_USES_STATIC_BUF */
+    left -= cop;
+    ofo += nfb;
+  }
+#if IP_FRAG_USES_STATIC_BUF
+  pbuf_free(rambuf);
+#endif /* IP_FRAG_USES_STATIC_BUF */
+  MIB2_STATS_INC(mib2.ipfragoks);
+  return ERR_OK;
+memerr:
+  MIB2_STATS_INC(mib2.ipfragfails);
+  return ERR_MEM;
+}
+#endif /* IP_FRAG */
+
+#endif /* LWIP_IPV4 */

ext/lwip/src/core/ipv6/README

@@ -0,0 +1 @@
+IPv6 support in lwIP is very experimental.

ext/lwip/src/core/ipv6/dhcp6.c

@@ -0,0 +1,50 @@
+/**
+ * @file
+ *
+ * DHCPv6.
+ */
+
+/*
+ * Copyright (c) 2010 Inico Technologies Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Ivan Delamer <delamer@inicotech.com>
+ *
+ *
+ * Please coordinate changes and requests with Ivan Delamer
+ * <delamer@inicotech.com>
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV6 && LWIP_IPV6_DHCP6 /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/ip6_addr.h"
+#include "lwip/def.h"
+
+
+#endif /* LWIP_IPV6 && LWIP_IPV6_DHCP6 */

ext/lwip/src/core/ipv6/ethip6.c

@@ -0,0 +1,157 @@
+/**
+ * @file
+ *
+ * Ethernet output for IPv6. Uses ND tables for link-layer addressing.
+ */
+
+/*
+ * Copyright (c) 2010 Inico Technologies Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Ivan Delamer <delamer@inicotech.com>
+ *
+ *
+ * Please coordinate changes and requests with Ivan Delamer
+ * <delamer@inicotech.com>
+ */
+
+#include "lwip/opt.h"
+
+
+
+#include "lwip/ethip6.h"
+#include "lwip/nd6.h"
+#include "lwip/pbuf.h"
+#include "lwip/ip6.h"
+#include "lwip/ip6_addr.h"
+#include "lwip/inet_chksum.h"
+#include "lwip/netif.h"
+#include "lwip/icmp6.h"
+#include "netif/ethernet.h"
+
+#include <string.h>
+
+/**
+ * Send an IPv6 packet on the network using netif->linkoutput
+ * The ethernet header is filled in before sending.
+ *
+ * @params netif the lwIP network interface on which to send the packet
+ * @params p the packet to send, p->payload pointing to the (uninitialized) ethernet header
+ * @params src the source MAC address to be copied into the ethernet header
+ * @params dst the destination MAC address to be copied into the ethernet header
+ * @return ERR_OK if the packet was sent, any other err_t on failure
+ */
+static err_t
+ethip6_send(struct netif *netif, struct pbuf *p, struct eth_addr *src, struct eth_addr *dst)
+{
+  struct eth_hdr *ethhdr = (struct eth_hdr *)p->payload;
+
+  LWIP_ASSERT("netif->hwaddr_len must be 6 for ethip6!",
+              (netif->hwaddr_len == 6));
+  SMEMCPY(&ethhdr->dest, dst, 6);
+  SMEMCPY(&ethhdr->src, src, 6);
+  ethhdr->type = PP_HTONS(ETHTYPE_IPV6);
+  LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE, ("ethip6_send: sending packet %p\n", (void *)p));
+  /* send the packet */
+  return netif->linkoutput(netif, p);
+}
+
+/**
+ * Resolve and fill-in Ethernet address header for outgoing IPv6 packet.
+ *
+ * For IPv6 multicast, corresponding Ethernet addresses
+ * are selected and the packet is transmitted on the link.
+ *
+ * For unicast addresses, ...
+ *
+ * @todo anycast addresses
+ *
+ * @param netif The lwIP network interface which the IP packet will be sent on.
+ * @param q The pbuf(s) containing the IP packet to be sent.
+ * @param ip6addr The IP address of the packet destination.
+ *
+ * @return
+ * - ERR_RTE No route to destination (no gateway to external networks),
+ * or the return type of either etharp_query() or etharp_send_ip().
+ */
+err_t
+ethip6_output(struct netif *netif, struct pbuf *q, const ip6_addr_t *ip6addr)
+{
+  struct eth_addr dest;
+  s8_t i;
+
+  /* make room for Ethernet header - should not fail */
+  if (pbuf_header(q, sizeof(struct eth_hdr)) != 0) {
+    /* bail out */
+    LWIP_DEBUGF(ETHARP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS,
+      ("etharp_output: could not allocate room for header.\n"));
+    return ERR_BUF;
+  }
+
+  /* multicast destination IP address? */
+  if (ip6_addr_ismulticast(ip6addr)) {
+    /* Hash IP multicast address to MAC address.*/
+    dest.addr[0] = 0x33;
+    dest.addr[1] = 0x33;
+    dest.addr[2] = ((const u8_t *)(&(ip6addr->addr[3])))[0];
+    dest.addr[3] = ((const u8_t *)(&(ip6addr->addr[3])))[1];
+    dest.addr[4] = ((const u8_t *)(&(ip6addr->addr[3])))[2];
+    dest.addr[5] = ((const u8_t *)(&(ip6addr->addr[3])))[3];
+
+    /* Send out. */
+    return ethip6_send(netif, q, (struct eth_addr*)(netif->hwaddr), &dest);
+  }
+
+  /* We have a unicast destination IP address */
+  /* @todo anycast? */
+  /* Get next hop record. */
+  i = nd6_get_next_hop_entry(ip6addr, netif);
+  if (i < 0) {
+    /* failed to get a next hop neighbor record. */
+    return ERR_MEM;
+  }
+
+  /* Now that we have a destination record, send or queue the packet. */
+  if (neighbor_cache[i].state == ND6_STALE) {
+    /* Switch to delay state. */
+    neighbor_cache[i].state = ND6_DELAY;
+    neighbor_cache[i].counter.delay_time = LWIP_ND6_DELAY_FIRST_PROBE_TIME;
+  }
+  /* @todo should we send or queue if PROBE? send for now, to let unicast NS pass. */
+  if ((neighbor_cache[i].state == ND6_REACHABLE) ||
+      (neighbor_cache[i].state == ND6_DELAY) ||
+      (neighbor_cache[i].state == ND6_PROBE)) {
+
+    /* Send out. */
+    SMEMCPY(dest.addr, neighbor_cache[i].lladdr, 6);
+    return ethip6_send(netif, q, (struct eth_addr*)(netif->hwaddr), &dest);
+  }
+  /* We should queue packet on this interface. */
+  pbuf_header(q, -(s16_t)SIZEOF_ETH_HDR);
+  return nd6_queue_packet(i, q);
+}
+

ext/lwip/src/core/ipv6/icmp6.c

@@ -0,0 +1,349 @@
+/**
+ * @file
+ *
+ * IPv6 version of ICMP, as per RFC 4443.
+ */
+
+/*
+ * Copyright (c) 2010 Inico Technologies Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Ivan Delamer <delamer@inicotech.com>
+ *
+ *
+ * Please coordinate changes and requests with Ivan Delamer
+ * <delamer@inicotech.com>
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_ICMP6 && LWIP_IPV6 /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/icmp6.h"
+#include "lwip/ip6.h"
+#include "lwip/ip6_addr.h"
+#include "lwip/inet_chksum.h"
+#include "lwip/pbuf.h"
+#include "lwip/netif.h"
+#include "lwip/nd6.h"
+#include "lwip/mld6.h"
+#include "lwip/ip.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+#ifndef LWIP_ICMP6_DATASIZE
+#define LWIP_ICMP6_DATASIZE   8
+#endif
+#if LWIP_ICMP6_DATASIZE == 0
+#define LWIP_ICMP6_DATASIZE   8
+#endif
+
+/* Forward declarations */
+static void icmp6_send_response(struct pbuf *p, u8_t code, u32_t data, u8_t type);
+
+
+/**
+ * Process an input ICMPv6 message. Called by ip6_input.
+ *
+ * Will generate a reply for echo requests. Other messages are forwarded
+ * to nd6_input, or mld6_input.
+ *
+ * @param p the mld packet, p->payload pointing to the icmpv6 header
+ * @param inp the netif on which this packet was received
+ */
+void
+icmp6_input(struct pbuf *p, struct netif *inp)
+{
+  struct icmp6_hdr *icmp6hdr;
+  struct pbuf * r;
+  const ip6_addr_t * reply_src;
+
+  ICMP6_STATS_INC(icmp6.recv);
+
+  /* Check that ICMPv6 header fits in payload */
+  if (p->len < sizeof(struct icmp6_hdr)) {
+    /* drop short packets */
+    pbuf_free(p);
+    ICMP6_STATS_INC(icmp6.lenerr);
+    ICMP6_STATS_INC(icmp6.drop);
+    return;
+  }
+
+  icmp6hdr = (struct icmp6_hdr *)p->payload;
+
+#if CHECKSUM_CHECK_ICMP6
+  IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP6) {
+    if (ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->tot_len, ip6_current_src_addr(),
+                          ip6_current_dest_addr()) != 0) {
+      /* Checksum failed */
+      pbuf_free(p);
+      ICMP6_STATS_INC(icmp6.chkerr);
+      ICMP6_STATS_INC(icmp6.drop);
+      return;
+    }
+  }
+#endif /* CHECKSUM_CHECK_ICMP6 */
+
+  switch (icmp6hdr->type) {
+  case ICMP6_TYPE_NA: /* Neighbor advertisement */
+  case ICMP6_TYPE_NS: /* Neighbor solicitation */
+  case ICMP6_TYPE_RA: /* Router advertisement */
+  case ICMP6_TYPE_RD: /* Redirect */
+  case ICMP6_TYPE_PTB: /* Packet too big */
+    nd6_input(p, inp);
+    return;
+    break;
+  case ICMP6_TYPE_RS:
+#if LWIP_IPV6_FORWARD
+    /* @todo implement router functionality */
+#endif
+    break;
+#if LWIP_IPV6_MLD
+  case ICMP6_TYPE_MLQ:
+  case ICMP6_TYPE_MLR:
+  case ICMP6_TYPE_MLD:
+    mld6_input(p, inp);
+    return;
+    break;
+#endif
+  case ICMP6_TYPE_EREQ:
+#if !LWIP_MULTICAST_PING
+    /* multicast destination address? */
+    if (ip6_addr_ismulticast(ip6_current_dest_addr())) {
+      /* drop */
+      pbuf_free(p);
+      ICMP6_STATS_INC(icmp6.drop);
+      return;
+    }
+#endif /* LWIP_MULTICAST_PING */
+
+    /* Allocate reply. */
+    r = pbuf_alloc(PBUF_IP, p->tot_len, PBUF_RAM);
+    if (r == NULL) {
+      /* drop */
+      pbuf_free(p);
+      ICMP6_STATS_INC(icmp6.memerr);
+      return;
+    }
+
+    /* Copy echo request. */
+    if (pbuf_copy(r, p) != ERR_OK) {
+      /* drop */
+      pbuf_free(p);
+      pbuf_free(r);
+      ICMP6_STATS_INC(icmp6.err);
+      return;
+    }
+
+    /* Determine reply source IPv6 address. */
+#if LWIP_MULTICAST_PING
+    if (ip6_addr_ismulticast(ip6_current_dest_addr())) {
+      reply_src = ip_2_ip6(ip6_select_source_address(inp, ip6_current_src_addr()));
+      if (reply_src == NULL) {
+        /* drop */
+        pbuf_free(p);
+        pbuf_free(r);
+        ICMP6_STATS_INC(icmp6.rterr);
+        return;
+      }
+    }
+    else
+#endif /* LWIP_MULTICAST_PING */
+    {
+      reply_src = ip6_current_dest_addr();
+    }
+
+    /* Set fields in reply. */
+    ((struct icmp6_echo_hdr *)(r->payload))->type = ICMP6_TYPE_EREP;
+    ((struct icmp6_echo_hdr *)(r->payload))->chksum = 0;
+#if CHECKSUM_GEN_ICMP6
+    IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP6) {
+      ((struct icmp6_echo_hdr *)(r->payload))->chksum = ip6_chksum_pseudo(r,
+          IP6_NEXTH_ICMP6, r->tot_len, reply_src, ip6_current_src_addr());
+    }
+#endif /* CHECKSUM_GEN_ICMP6 */
+
+    /* Send reply. */
+    ICMP6_STATS_INC(icmp6.xmit);
+    ip6_output_if(r, reply_src, ip6_current_src_addr(),
+        LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, inp);
+    pbuf_free(r);
+
+    break;
+  default:
+    ICMP6_STATS_INC(icmp6.proterr);
+    ICMP6_STATS_INC(icmp6.drop);
+    break;
+  }
+
+  pbuf_free(p);
+}
+
+
+/**
+ * Send an icmpv6 'destination unreachable' packet.
+ *
+ * @param p the input packet for which the 'unreachable' should be sent,
+ *          p->payload pointing to the IPv6 header
+ * @param c ICMPv6 code for the unreachable type
+ */
+void
+icmp6_dest_unreach(struct pbuf *p, enum icmp6_dur_code c)
+{
+  icmp6_send_response(p, c, 0, ICMP6_TYPE_DUR);
+}
+
+/**
+ * Send an icmpv6 'packet too big' packet.
+ *
+ * @param p the input packet for which the 'packet too big' should be sent,
+ *          p->payload pointing to the IPv6 header
+ * @param mtu the maximum mtu that we can accept
+ */
+void
+icmp6_packet_too_big(struct pbuf *p, u32_t mtu)
+{
+  icmp6_send_response(p, 0, mtu, ICMP6_TYPE_PTB);
+}
+
+/**
+ * Send an icmpv6 'time exceeded' packet.
+ *
+ * @param p the input packet for which the 'unreachable' should be sent,
+ *          p->payload pointing to the IPv6 header
+ * @param c ICMPv6 code for the time exceeded type
+ */
+void
+icmp6_time_exceeded(struct pbuf *p, enum icmp6_te_code c)
+{
+  icmp6_send_response(p, c, 0, ICMP6_TYPE_TE);
+}
+
+/**
+ * Send an icmpv6 'parameter problem' packet.
+ *
+ * @param p the input packet for which the 'param problem' should be sent,
+ *          p->payload pointing to the IP header
+ * @param c ICMPv6 code for the param problem type
+ * @param pointer the pointer to the byte where the parameter is found
+ */
+void
+icmp6_param_problem(struct pbuf *p, enum icmp6_pp_code c, u32_t pointer)
+{
+  icmp6_send_response(p, c, pointer, ICMP6_TYPE_PP);
+}
+
+/**
+ * Send an ICMPv6 packet in response to an incoming packet.
+ *
+ * @param p the input packet for which the response should be sent,
+ *          p->payload pointing to the IPv6 header
+ * @param code Code of the ICMPv6 header
+ * @param data Additional 32-bit parameter in the ICMPv6 header
+ * @param type Type of the ICMPv6 header
+ */
+static void
+icmp6_send_response(struct pbuf *p, u8_t code, u32_t data, u8_t type)
+{
+  struct pbuf *q;
+  struct icmp6_hdr *icmp6hdr;
+  const ip6_addr_t *reply_src;
+  ip6_addr_t *reply_dest;
+  ip6_addr_t reply_src_local, reply_dest_local;
+  struct ip6_hdr *ip6hdr;
+  struct netif *netif;
+
+  /* ICMPv6 header + IPv6 header + data */
+  q = pbuf_alloc(PBUF_IP, sizeof(struct icmp6_hdr) + IP6_HLEN + LWIP_ICMP6_DATASIZE,
+                 PBUF_RAM);
+  if (q == NULL) {
+    LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMPv6 packet.\n"));
+    ICMP6_STATS_INC(icmp6.memerr);
+    return;
+  }
+  LWIP_ASSERT("check that first pbuf can hold icmp 6message",
+             (q->len >= (sizeof(struct icmp6_hdr) + IP6_HLEN + LWIP_ICMP6_DATASIZE)));
+
+  icmp6hdr = (struct icmp6_hdr *)q->payload;
+  icmp6hdr->type = type;
+  icmp6hdr->code = code;
+  icmp6hdr->data = data;
+
+  /* copy fields from original packet */
+  SMEMCPY((u8_t *)q->payload + sizeof(struct icmp6_hdr), (u8_t *)p->payload,
+          IP6_HLEN + LWIP_ICMP6_DATASIZE);
+
+  /* Get the destination address and netif for this ICMP message. */
+  if ((ip_current_netif() == NULL) ||
+      ((code == ICMP6_TE_FRAG) && (type == ICMP6_TYPE_TE))) {
+    /* Special case, as ip6_current_xxx is either NULL, or points
+     * to a different packet than the one that expired.
+     * We must use the addresses that are stored in the expired packet. */
+    ip6hdr = (struct ip6_hdr *)p->payload;
+    /* copy from packed address to aligned address */
+    ip6_addr_copy(reply_dest_local, ip6hdr->src);
+    ip6_addr_copy(reply_src_local, ip6hdr->dest);
+    reply_dest = &reply_dest_local;
+    reply_src = &reply_src_local;
+    netif = ip6_route(reply_src, reply_dest);
+    if (netif == NULL) {
+      /* drop */
+      pbuf_free(q);
+      ICMP6_STATS_INC(icmp6.rterr);
+      return;
+    }
+  }
+  else {
+    netif = ip_current_netif();
+    reply_dest = ip6_current_src_addr();
+
+    /* Select an address to use as source. */
+    reply_src = ip_2_ip6(ip6_select_source_address(netif, reply_dest));
+    if (reply_src == NULL) {
+      /* drop */
+      pbuf_free(q);
+      ICMP6_STATS_INC(icmp6.rterr);
+      return;
+    }
+  }
+
+  /* calculate checksum */
+  icmp6hdr->chksum = 0;
+#if CHECKSUM_GEN_ICMP6
+  IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_ICMP6) {
+    icmp6hdr->chksum = ip6_chksum_pseudo(q, IP6_NEXTH_ICMP6, q->tot_len,
+      reply_src, reply_dest);
+  }
+#endif /* CHECKSUM_GEN_ICMP6 */
+
+  ICMP6_STATS_INC(icmp6.xmit);
+  ip6_output_if(q, reply_src, reply_dest, LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, netif);
+  pbuf_free(q);
+}
+
+#endif /* LWIP_ICMP6 && LWIP_IPV6 */

ext/lwip/src/core/ipv6/inet6.c

@@ -0,0 +1,53 @@
+/**
+ * @file
+ *
+ * INET v6 addresses.
+ */
+
+/*
+ * Copyright (c) 2010 Inico Technologies Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Ivan Delamer <delamer@inicotech.com>
+ *
+ *
+ * Please coordinate changes and requests with Ivan Delamer
+ * <delamer@inicotech.com>
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV6 && LWIP_SOCKET /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/def.h"
+#include "lwip/inet.h"
+
+/** This variable is initialized by the system to contain the wildcard IPv6 address.
+ */
+const struct in6_addr in6addr_any = IN6ADDR_ANY_INIT;
+
+#endif /* LWIP_IPV6 */

ext/lwip/src/core/ipv6/ip6_addr.c

@@ -0,0 +1,292 @@
+/**
+ * @file
+ *
+ * IPv6 addresses.
+ */
+
+/*
+ * Copyright (c) 2010 Inico Technologies Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Ivan Delamer <delamer@inicotech.com>
+ *
+ * Functions for handling IPv6 addresses.
+ *
+ * Please coordinate changes and requests with Ivan Delamer
+ * <delamer@inicotech.com>
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV6  /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/ip_addr.h"
+#include "lwip/def.h"
+
+/* used by IP6_ADDR_ANY(6) in ip6_addr.h */
+const ip_addr_t ip6_addr_any = IPADDR6_INIT(0ul, 0ul, 0ul, 0ul);
+
+#ifndef isprint
+#define in_range(c, lo, up)  ((u8_t)c >= lo && (u8_t)c <= up)
+#define isprint(c)           in_range(c, 0x20, 0x7f)
+#define isdigit(c)           in_range(c, '0', '9')
+#define isxdigit(c)          (isdigit(c) || in_range(c, 'a', 'f') || in_range(c, 'A', 'F'))
+#define islower(c)           in_range(c, 'a', 'z')
+#define isspace(c)           (c == ' ' || c == '\f' || c == '\n' || c == '\r' || c == '\t' || c == '\v')
+#define xchar(i)             ((i) < 10 ? '0' + (i) : 'A' + (i) - 10)
+#endif
+
+/**
+ * Check whether "cp" is a valid ascii representation
+ * of an IPv6 address and convert to a binary address.
+ * Returns 1 if the address is valid, 0 if not.
+ *
+ * @param cp IPv6 address in ascii representation (e.g. "FF01::1")
+ * @param addr pointer to which to save the ip address in network order
+ * @return 1 if cp could be converted to addr, 0 on failure
+ */
+int
+ip6addr_aton(const char *cp, ip6_addr_t *addr)
+{
+  u32_t addr_index, zero_blocks, current_block_index, current_block_value;
+  const char * s;
+
+  /* Count the number of colons, to count the number of blocks in a "::" sequence
+     zero_blocks may be 1 even if there are no :: sequences */
+  zero_blocks = 8;
+  for (s = cp; *s != 0; s++) {
+    if (*s == ':') {
+      zero_blocks--;
+    } else if (!isxdigit(*s)) {
+      break;
+    }
+  }
+
+  /* parse each block */
+  addr_index = 0;
+  current_block_index = 0;
+  current_block_value = 0;
+  for (s = cp; *s != 0; s++) {
+    if (*s == ':') {
+      if (addr) {
+        if (current_block_index & 0x1) {
+          addr->addr[addr_index++] |= current_block_value;
+        }
+        else {
+          addr->addr[addr_index] = current_block_value << 16;
+        }
+      }
+      current_block_index++;
+      current_block_value = 0;
+      if (current_block_index > 7) {
+        /* address too long! */
+        return 0;
+      }
+      if (s[1] == ':') {
+        if (s[2] == ':') {
+          /* invalid format: three successive colons */
+          return 0;
+        }
+        s++;
+        /* "::" found, set zeros */
+        while (zero_blocks > 0) {
+          zero_blocks--;
+          if (current_block_index & 0x1) {
+            addr_index++;
+          } else {
+            if (addr) {
+              addr->addr[addr_index] = 0;
+            }
+          }
+          current_block_index++;
+          if (current_block_index > 7) {
+            /* address too long! */
+            return 0;
+          }
+        }
+      }
+    } else if (isxdigit(*s)) {
+      /* add current digit */
+      current_block_value = (current_block_value << 4) +
+          (isdigit(*s) ? *s - '0' :
+          10 + (islower(*s) ? *s - 'a' : *s - 'A'));
+    } else {
+      /* unexpected digit, space? CRLF? */
+      break;
+    }
+  }
+
+  if (addr) {
+    if (current_block_index & 0x1) {
+      addr->addr[addr_index++] |= current_block_value;
+    }
+    else {
+      addr->addr[addr_index] = current_block_value << 16;
+    }
+  }
+
+  /* convert to network byte order. */
+  if (addr) {
+    for (addr_index = 0; addr_index < 4; addr_index++) {
+      addr->addr[addr_index] = htonl(addr->addr[addr_index]);
+    }
+  }
+
+  if (current_block_index != 7) {
+    return 0;
+  }
+
+  return 1;
+}
+
+/**
+ * Convert numeric IPv6 address into ASCII representation.
+ * returns ptr to static buffer; not reentrant!
+ *
+ * @param addr ip6 address in network order to convert
+ * @return pointer to a global static (!) buffer that holds the ASCII
+ *         representation of addr
+ */
+char *
+ip6addr_ntoa(const ip6_addr_t *addr)
+{
+  static char str[40];
+  return ip6addr_ntoa_r(addr, str, 40);
+}
+
+/**
+ * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
+ *
+ * @param addr ip6 address in network order to convert
+ * @param buf target buffer where the string is stored
+ * @param buflen length of buf
+ * @return either pointer to buf which now holds the ASCII
+ *         representation of addr or NULL if buf was too small
+ */
+char *
+ip6addr_ntoa_r(const ip6_addr_t *addr, char *buf, int buflen)
+{
+  u32_t current_block_index, current_block_value, next_block_value;
+  s32_t i;
+  u8_t zero_flag, empty_block_flag;
+
+  i = 0;
+  empty_block_flag = 0; /* used to indicate a zero chain for "::' */
+
+  for (current_block_index = 0; current_block_index < 8; current_block_index++) {
+    /* get the current 16-bit block */
+    current_block_value = htonl(addr->addr[current_block_index >> 1]);
+    if ((current_block_index & 0x1) == 0) {
+      current_block_value = current_block_value >> 16;
+    }
+    current_block_value &= 0xffff;
+
+    /* Check for empty block. */
+    if (current_block_value == 0) {
+      if (current_block_index == 7 && empty_block_flag == 1) {
+        /* special case, we must render a ':' for the last block. */
+        buf[i++] = ':';
+        if (i >= buflen) {
+          return NULL;
+        }
+        break;
+      }
+      if (empty_block_flag == 0) {
+        /* generate empty block "::", but only if more than one contiguous zero block,
+         * according to current formatting suggestions RFC 5952. */
+        next_block_value = htonl(addr->addr[(current_block_index + 1) >> 1]);
+        if ((current_block_index & 0x1) == 0x01) {
+            next_block_value = next_block_value >> 16;
+        }
+        next_block_value &= 0xffff;
+        if (next_block_value == 0) {
+          empty_block_flag = 1;
+          buf[i++] = ':';
+          if (i >= buflen) {
+            return NULL;
+          }
+          continue; /* move on to next block. */
+        }
+      } else if (empty_block_flag == 1) {
+        /* move on to next block. */
+        continue;
+      }
+    } else if (empty_block_flag == 1) {
+      /* Set this flag value so we don't produce multiple empty blocks. */
+      empty_block_flag = 2;
+    }
+
+    if (current_block_index > 0) {
+      buf[i++] = ':';
+      if (i >= buflen) {
+        return NULL;
+      }
+    }
+
+    if ((current_block_value & 0xf000) == 0) {
+      zero_flag = 1;
+    } else {
+      buf[i++] = xchar(((current_block_value & 0xf000) >> 12));
+      zero_flag = 0;
+      if (i >= buflen) {
+        return NULL;
+      }
+    }
+
+    if (((current_block_value & 0xf00) == 0) && (zero_flag)) {
+      /* do nothing */
+    } else {
+      buf[i++] = xchar(((current_block_value & 0xf00) >> 8));
+      zero_flag = 0;
+      if (i >= buflen) {
+        return NULL;
+      }
+    }
+
+    if (((current_block_value & 0xf0) == 0) && (zero_flag)) {
+      /* do nothing */
+    }
+    else {
+      buf[i++] = xchar(((current_block_value & 0xf0) >> 4));
+      zero_flag = 0;
+      if (i >= buflen) {
+        return NULL;
+      }
+    }
+
+    buf[i++] = xchar((current_block_value & 0xf));
+    if (i >= buflen) {
+      return NULL;
+    }
+  }
+
+  buf[i] = 0;
+
+  return buf;
+}
+
+#endif /* LWIP_IPV6 */

ext/lwip/src/core/ipv6/ip6_frag.c

@@ -0,0 +1,776 @@
+/**
+ * @file
+ *
+ * IPv6 fragmentation and reassembly.
+ */
+
+/*
+ * Copyright (c) 2010 Inico Technologies Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Ivan Delamer <delamer@inicotech.com>
+ *
+ *
+ * Please coordinate changes and requests with Ivan Delamer
+ * <delamer@inicotech.com>
+ */
+
+#include "lwip/opt.h"
+#include "lwip/ip6_frag.h"
+#include "lwip/ip6.h"
+#include "lwip/icmp6.h"
+#include "lwip/nd6.h"
+#include "lwip/ip.h"
+
+#include "lwip/pbuf.h"
+#include "lwip/memp.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+#if LWIP_IPV6 && LWIP_IPV6_REASS  /* don't build if not configured for use in lwipopts.h */
+
+
+/** Setting this to 0, you can turn off checking the fragments for overlapping
+ * regions. The code gets a little smaller. Only use this if you know that
+ * overlapping won't occur on your network! */
+#ifndef IP_REASS_CHECK_OVERLAP
+#define IP_REASS_CHECK_OVERLAP 1
+#endif /* IP_REASS_CHECK_OVERLAP */
+
+/** Set to 0 to prevent freeing the oldest datagram when the reassembly buffer is
+ * full (IP_REASS_MAX_PBUFS pbufs are enqueued). The code gets a little smaller.
+ * Datagrams will be freed by timeout only. Especially useful when MEMP_NUM_REASSDATA
+ * is set to 1, so one datagram can be reassembled at a time, only. */
+#ifndef IP_REASS_FREE_OLDEST
+#define IP_REASS_FREE_OLDEST 1
+#endif /* IP_REASS_FREE_OLDEST */
+
+#if IPV6_FRAG_COPYHEADER
+#define IPV6_FRAG_REQROOM ((s16_t)(sizeof(struct ip6_reass_helper) - IP6_FRAG_HLEN))
+#endif
+
+#define IP_REASS_FLAG_LASTFRAG 0x01
+
+/** This is a helper struct which holds the starting
+ * offset and the ending offset of this fragment to
+ * easily chain the fragments.
+ * It has the same packing requirements as the IPv6 header, since it replaces
+ * the Fragment Header in memory in incoming fragments to keep
+ * track of the various fragments.
+ */
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/bpstruct.h"
+#endif
+PACK_STRUCT_BEGIN
+struct ip6_reass_helper {
+  PACK_STRUCT_FIELD(struct pbuf *next_pbuf);
+  PACK_STRUCT_FIELD(u16_t start);
+  PACK_STRUCT_FIELD(u16_t end);
+} PACK_STRUCT_STRUCT;
+PACK_STRUCT_END
+#ifdef PACK_STRUCT_USE_INCLUDES
+#  include "arch/epstruct.h"
+#endif
+
+/* static variables */
+static struct ip6_reassdata *reassdatagrams;
+static u16_t ip6_reass_pbufcount;
+
+/* Forward declarations. */
+static void ip6_reass_free_complete_datagram(struct ip6_reassdata *ipr);
+#if IP_REASS_FREE_OLDEST
+static void ip6_reass_remove_oldest_datagram(struct ip6_reassdata *ipr, int pbufs_needed);
+#endif /* IP_REASS_FREE_OLDEST */
+
+void
+ip6_reass_tmr(void)
+{
+  struct ip6_reassdata *r, *tmp;
+
+#if !IPV6_FRAG_COPYHEADER
+  LWIP_ASSERT("sizeof(struct ip6_reass_helper) <= IP6_FRAG_HLEN, set IPV6_FRAG_COPYHEADER to 1",
+    sizeof(struct ip6_reass_helper) <= IP6_FRAG_HLEN);
+#endif /* !IPV6_FRAG_COPYHEADER */
+
+  r = reassdatagrams;
+  while (r != NULL) {
+    /* Decrement the timer. Once it reaches 0,
+     * clean up the incomplete fragment assembly */
+    if (r->timer > 0) {
+      r->timer--;
+      r = r->next;
+    } else {
+      /* reassembly timed out */
+      tmp = r;
+      /* get the next pointer before freeing */
+      r = r->next;
+      /* free the helper struct and all enqueued pbufs */
+      ip6_reass_free_complete_datagram(tmp);
+     }
+   }
+}
+
+/**
+ * Free a datagram (struct ip6_reassdata) and all its pbufs.
+ * Updates the total count of enqueued pbufs (ip6_reass_pbufcount),
+ * sends an ICMP time exceeded packet.
+ *
+ * @param ipr datagram to free
+ */
+static void
+ip6_reass_free_complete_datagram(struct ip6_reassdata *ipr)
+{
+  struct ip6_reassdata *prev;
+  u16_t pbufs_freed = 0;
+  u8_t clen;
+  struct pbuf *p;
+  struct ip6_reass_helper *iprh;
+
+#if LWIP_ICMP6
+  iprh = (struct ip6_reass_helper *)ipr->p->payload;
+  if (iprh->start == 0) {
+    /* The first fragment was received, send ICMP time exceeded. */
+    /* First, de-queue the first pbuf from r->p. */
+    p = ipr->p;
+    ipr->p = iprh->next_pbuf;
+    /* Then, move back to the original ipv6 header (we are now pointing to Fragment header).
+       This cannot fail since we already checked when receiving this fragment. */
+    if (pbuf_header_force(p, (s16_t)((u8_t*)p->payload - (u8_t*)IPV6_FRAG_HDRREF(ipr->iphdr)))) {
+      LWIP_ASSERT("ip6_reass_free: moving p->payload to ip6 header failed\n", 0);
+    }
+    else {
+      icmp6_time_exceeded(p, ICMP6_TE_FRAG);
+    }
+    clen = pbuf_clen(p);
+    LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
+    pbufs_freed += clen;
+    pbuf_free(p);
+  }
+#endif /* LWIP_ICMP6 */
+
+  /* First, free all received pbufs.  The individual pbufs need to be released
+     separately as they have not yet been chained */
+  p = ipr->p;
+  while (p != NULL) {
+    struct pbuf *pcur;
+    iprh = (struct ip6_reass_helper *)p->payload;
+    pcur = p;
+    /* get the next pointer before freeing */
+    p = iprh->next_pbuf;
+    clen = pbuf_clen(pcur);
+    LWIP_ASSERT("pbufs_freed + clen <= 0xffff", pbufs_freed + clen <= 0xffff);
+    pbufs_freed += clen;
+    pbuf_free(pcur);
+  }
+
+  /* Then, unchain the struct ip6_reassdata from the list and free it. */
+  if (ipr == reassdatagrams) {
+    reassdatagrams = ipr->next;
+  } else {
+    prev = reassdatagrams;
+    while (prev != NULL) {
+      if (prev->next == ipr) {
+        break;
+      }
+      prev = prev->next;
+    }
+    if (prev != NULL) {
+      prev->next = ipr->next;
+    }
+  }
+  memp_free(MEMP_IP6_REASSDATA, ipr);
+
+  /* Finally, update number of pbufs in reassembly queue */
+  LWIP_ASSERT("ip_reass_pbufcount >= clen", ip6_reass_pbufcount >= pbufs_freed);
+  ip6_reass_pbufcount -= pbufs_freed;
+}
+
+#if IP_REASS_FREE_OLDEST
+/**
+ * Free the oldest datagram to make room for enqueueing new fragments.
+ * The datagram ipr is not freed!
+ *
+ * @param ipr ip6_reassdata for the current fragment
+ * @param pbufs_needed number of pbufs needed to enqueue
+ *        (used for freeing other datagrams if not enough space)
+ */
+static void
+ip6_reass_remove_oldest_datagram(struct ip6_reassdata *ipr, int pbufs_needed)
+{
+  struct ip6_reassdata *r, *oldest;
+
+  /* Free datagrams until being allowed to enqueue 'pbufs_needed' pbufs,
+   * but don't free the current datagram! */
+  do {
+    r = oldest = reassdatagrams;
+    while (r != NULL) {
+      if (r != ipr) {
+        if (r->timer <= oldest->timer) {
+          /* older than the previous oldest */
+          oldest = r;
+        }
+      }
+      r = r->next;
+    }
+    if (oldest == ipr) {
+      /* nothing to free, ipr is the only element on the list */
+      return;
+    }
+    if (oldest != NULL) {
+      ip6_reass_free_complete_datagram(oldest);
+    }
+  } while (((ip6_reass_pbufcount + pbufs_needed) > IP_REASS_MAX_PBUFS) && (reassdatagrams != NULL));
+}
+#endif /* IP_REASS_FREE_OLDEST */
+
+/**
+ * Reassembles incoming IPv6 fragments into an IPv6 datagram.
+ *
+ * @param p points to the IPv6 Fragment Header
+ * @return NULL if reassembly is incomplete, pbuf pointing to
+ *         IPv6 Header if reassembly is complete
+ */
+struct pbuf *
+ip6_reass(struct pbuf *p)
+{
+  struct ip6_reassdata *ipr, *ipr_prev;
+  struct ip6_reass_helper *iprh, *iprh_tmp, *iprh_prev=NULL;
+  struct ip6_frag_hdr * frag_hdr;
+  u16_t offset, len;
+  u8_t clen, valid = 1;
+  struct pbuf *q;
+
+  IP6_FRAG_STATS_INC(ip6_frag.recv);
+
+  if ((const void*)ip6_current_header() != ((u8_t*)p->payload) - IP6_HLEN) {
+    /* ip6_frag_hdr must be in the first pbuf, not chained */
+    IP6_FRAG_STATS_INC(ip6_frag.proterr);
+    IP6_FRAG_STATS_INC(ip6_frag.drop);
+    goto nullreturn;
+  }
+
+  frag_hdr = (struct ip6_frag_hdr *) p->payload;
+
+  clen = pbuf_clen(p);
+
+  offset = ntohs(frag_hdr->_fragment_offset);
+
+  /* Calculate fragment length from IPv6 payload length.
+   * Adjust for headers before Fragment Header.
+   * And finally adjust by Fragment Header length. */
+  len = ntohs(ip6_current_header()->_plen);
+  len -= (u16_t)(((u8_t*)p->payload - (const u8_t*)ip6_current_header()) - IP6_HLEN);
+  len -= IP6_FRAG_HLEN;
+
+  /* Look for the datagram the fragment belongs to in the current datagram queue,
+   * remembering the previous in the queue for later dequeueing. */
+  for (ipr = reassdatagrams, ipr_prev = NULL; ipr != NULL; ipr = ipr->next) {
+    /* Check if the incoming fragment matches the one currently present
+       in the reassembly buffer. If so, we proceed with copying the
+       fragment into the buffer. */
+    if ((frag_hdr->_identification == ipr->identification) &&
+        ip6_addr_cmp(ip6_current_src_addr(), &(IPV6_FRAG_HDRREF(ipr->iphdr)->src)) &&
+        ip6_addr_cmp(ip6_current_dest_addr(), &(IPV6_FRAG_HDRREF(ipr->iphdr)->dest))) {
+      IP6_FRAG_STATS_INC(ip6_frag.cachehit);
+      break;
+    }
+    ipr_prev = ipr;
+  }
+
+  if (ipr == NULL) {
+  /* Enqueue a new datagram into the datagram queue */
+    ipr = (struct ip6_reassdata *)memp_malloc(MEMP_IP6_REASSDATA);
+    if (ipr == NULL) {
+#if IP_REASS_FREE_OLDEST
+      /* Make room and try again. */
+      ip6_reass_remove_oldest_datagram(ipr, clen);
+      ipr = (struct ip6_reassdata *)memp_malloc(MEMP_IP6_REASSDATA);
+      if (ipr != NULL) {
+        /* re-search ipr_prev since it might have been removed */
+        for (ipr_prev = reassdatagrams; ipr_prev != NULL; ipr_prev = ipr_prev->next) {
+          if (ipr_prev->next == ipr) {
+            break;
+          }
+        }
+      } else
+#endif /* IP_REASS_FREE_OLDEST */
+      {
+        IP6_FRAG_STATS_INC(ip6_frag.memerr);
+        IP6_FRAG_STATS_INC(ip6_frag.drop);
+        goto nullreturn;
+      }
+    }
+
+    memset(ipr, 0, sizeof(struct ip6_reassdata));
+    ipr->timer = IP_REASS_MAXAGE;
+
+    /* enqueue the new structure to the front of the list */
+    ipr->next = reassdatagrams;
+    reassdatagrams = ipr;
+
+    /* Use the current IPv6 header for src/dest address reference.
+     * Eventually, we will replace it when we get the first fragment
+     * (it might be this one, in any case, it is done later). */
+#if IPV6_FRAG_COPYHEADER
+    MEMCPY(&ipr->iphdr, ip6_current_header(), IP6_HLEN);
+#else /* IPV6_FRAG_COPYHEADER */
+    /* need to use the none-const pointer here: */
+    ipr->iphdr = ip_data.current_ip6_header;
+#endif /* IPV6_FRAG_COPYHEADER */
+
+    /* copy the fragmented packet id. */
+    ipr->identification = frag_hdr->_identification;
+
+    /* copy the nexth field */
+    ipr->nexth = frag_hdr->_nexth;
+  }
+
+  /* Check if we are allowed to enqueue more datagrams. */
+  if ((ip6_reass_pbufcount + clen) > IP_REASS_MAX_PBUFS) {
+#if IP_REASS_FREE_OLDEST
+    ip6_reass_remove_oldest_datagram(ipr, clen);
+    if ((ip6_reass_pbufcount + clen) <= IP_REASS_MAX_PBUFS) {
+      /* re-search ipr_prev since it might have been removed */
+      for (ipr_prev = reassdatagrams; ipr_prev != NULL; ipr_prev = ipr_prev->next) {
+        if (ipr_prev->next == ipr) {
+          break;
+        }
+      }
+    } else
+#endif /* IP_REASS_FREE_OLDEST */
+    {
+      /* @todo: send ICMPv6 time exceeded here? */
+      /* drop this pbuf */
+      IP6_FRAG_STATS_INC(ip6_frag.memerr);
+      IP6_FRAG_STATS_INC(ip6_frag.drop);
+      goto nullreturn;
+    }
+  }
+
+  /* Overwrite Fragment Header with our own helper struct. */
+#if IPV6_FRAG_COPYHEADER
+  if (IPV6_FRAG_REQROOM > 0) {
+    /* Make room for struct ip6_reass_helper (only required if sizeof(void*) > 4).
+       This cannot fail since we already checked when receiving this fragment. */
+    err_t hdrerr = pbuf_header_force(p, IPV6_FRAG_REQROOM);
+    LWIP_ASSERT("no room for struct ip6_reass_helper", hdrerr == ERR_OK);
+  }
+#else /* IPV6_FRAG_COPYHEADER */
+  LWIP_ASSERT("sizeof(struct ip6_reass_helper) <= IP6_FRAG_HLEN, set IPV6_FRAG_COPYHEADER to 1",
+    sizeof(struct ip6_reass_helper) <= IP6_FRAG_HLEN);
+#endif /* IPV6_FRAG_COPYHEADER */
+  iprh = (struct ip6_reass_helper *)p->payload;
+  iprh->next_pbuf = NULL;
+  iprh->start = (offset & IP6_FRAG_OFFSET_MASK);
+  iprh->end = (offset & IP6_FRAG_OFFSET_MASK) + len;
+
+  /* find the right place to insert this pbuf */
+  /* Iterate through until we either get to the end of the list (append),
+   * or we find on with a larger offset (insert). */
+  for (q = ipr->p; q != NULL;) {
+    iprh_tmp = (struct ip6_reass_helper*)q->payload;
+    if (iprh->start < iprh_tmp->start) {
+#if IP_REASS_CHECK_OVERLAP
+      if (iprh->end > iprh_tmp->start) {
+        /* fragment overlaps with following, throw away */
+        IP6_FRAG_STATS_INC(ip6_frag.proterr);
+        IP6_FRAG_STATS_INC(ip6_frag.drop);
+        goto nullreturn;
+      }
+      if (iprh_prev != NULL) {
+        if (iprh->start < iprh_prev->end) {
+          /* fragment overlaps with previous, throw away */
+          IP6_FRAG_STATS_INC(ip6_frag.proterr);
+          IP6_FRAG_STATS_INC(ip6_frag.drop);
+          goto nullreturn;
+        }
+      }
+#endif /* IP_REASS_CHECK_OVERLAP */
+      /* the new pbuf should be inserted before this */
+      iprh->next_pbuf = q;
+      if (iprh_prev != NULL) {
+        /* not the fragment with the lowest offset */
+        iprh_prev->next_pbuf = p;
+      } else {
+        /* fragment with the lowest offset */
+        ipr->p = p;
+      }
+      break;
+    } else if (iprh->start == iprh_tmp->start) {
+      /* received the same datagram twice: no need to keep the datagram */
+      IP6_FRAG_STATS_INC(ip6_frag.drop);
+      goto nullreturn;
+#if IP_REASS_CHECK_OVERLAP
+    } else if (iprh->start < iprh_tmp->end) {
+      /* overlap: no need to keep the new datagram */
+      IP6_FRAG_STATS_INC(ip6_frag.proterr);
+      IP6_FRAG_STATS_INC(ip6_frag.drop);
+      goto nullreturn;
+#endif /* IP_REASS_CHECK_OVERLAP */
+    } else {
+      /* Check if the fragments received so far have no gaps. */
+      if (iprh_prev != NULL) {
+        if (iprh_prev->end != iprh_tmp->start) {
+          /* There is a fragment missing between the current
+           * and the previous fragment */
+          valid = 0;
+        }
+      }
+    }
+    q = iprh_tmp->next_pbuf;
+    iprh_prev = iprh_tmp;
+  }
+
+  /* If q is NULL, then we made it to the end of the list. Determine what to do now */
+  if (q == NULL) {
+    if (iprh_prev != NULL) {
+      /* this is (for now), the fragment with the highest offset:
+       * chain it to the last fragment */
+#if IP_REASS_CHECK_OVERLAP
+      LWIP_ASSERT("check fragments don't overlap", iprh_prev->end <= iprh->start);
+#endif /* IP_REASS_CHECK_OVERLAP */
+      iprh_prev->next_pbuf = p;
+      if (iprh_prev->end != iprh->start) {
+        valid = 0;
+      }
+    } else {
+#if IP_REASS_CHECK_OVERLAP
+      LWIP_ASSERT("no previous fragment, this must be the first fragment!",
+        ipr->p == NULL);
+#endif /* IP_REASS_CHECK_OVERLAP */
+      /* this is the first fragment we ever received for this ip datagram */
+      ipr->p = p;
+    }
+  }
+
+  /* Track the current number of pbufs current 'in-flight', in order to limit
+  the number of fragments that may be enqueued at any one time */
+  ip6_reass_pbufcount += clen;
+
+  /* Remember IPv6 header if this is the first fragment. */
+  if (iprh->start == 0) {
+#if IPV6_FRAG_COPYHEADER
+    if (iprh->next_pbuf != NULL) {
+      MEMCPY(&ipr->iphdr, ip6_current_header(), IP6_HLEN);
+    }
+#else /* IPV6_FRAG_COPYHEADER */
+    /* need to use the none-const pointer here: */
+    ipr->iphdr = ip_data.current_ip6_header;
+#endif /* IPV6_FRAG_COPYHEADER */
+  }
+
+  /* If this is the last fragment, calculate total packet length. */
+  if ((offset & IP6_FRAG_MORE_FLAG) == 0) {
+    ipr->datagram_len = iprh->end;
+  }
+
+  /* Additional validity tests: we have received first and last fragment. */
+  iprh_tmp = (struct ip6_reass_helper*)ipr->p->payload;
+  if (iprh_tmp->start != 0) {
+    valid = 0;
+  }
+  if (ipr->datagram_len == 0) {
+    valid = 0;
+  }
+
+  /* Final validity test: no gaps between current and last fragment. */
+  iprh_prev = iprh;
+  q = iprh->next_pbuf;
+  while ((q != NULL) && valid) {
+    iprh = (struct ip6_reass_helper*)q->payload;
+    if (iprh_prev->end != iprh->start) {
+      valid = 0;
+      break;
+    }
+    iprh_prev = iprh;
+    q = iprh->next_pbuf;
+  }
+
+  if (valid) {
+    /* All fragments have been received */
+    struct ip6_hdr* iphdr_ptr;
+
+    /* chain together the pbufs contained within the ip6_reassdata list. */
+    iprh = (struct ip6_reass_helper*) ipr->p->payload;
+    while (iprh != NULL) {
+      struct pbuf* next_pbuf = iprh->next_pbuf;
+      if (next_pbuf != NULL) {
+        /* Save next helper struct (will be hidden in next step). */
+        iprh_tmp = (struct ip6_reass_helper*)next_pbuf->payload;
+
+        /* hide the fragment header for every succeeding fragment */
+        pbuf_header(next_pbuf, -IP6_FRAG_HLEN);
+#if IPV6_FRAG_COPYHEADER
+        if (IPV6_FRAG_REQROOM > 0) {
+          /* hide the extra bytes borrowed from ip6_hdr for struct ip6_reass_helper */
+          err_t hdrerr = pbuf_header(next_pbuf, -(s16_t)(IPV6_FRAG_REQROOM));
+          LWIP_ASSERT("no room for struct ip6_reass_helper", hdrerr == ERR_OK);
+        }
+#endif
+        pbuf_cat(ipr->p, next_pbuf);
+      }
+      else {
+        iprh_tmp = NULL;
+      }
+
+      iprh = iprh_tmp;
+    }
+
+#if IPV6_FRAG_COPYHEADER
+    if (IPV6_FRAG_REQROOM > 0) {
+      /* get back room for struct ip6_reass_helper (only required if sizeof(void*) > 4) */
+      err_t hdrerr = pbuf_header(ipr->p, -(s16_t)(IPV6_FRAG_REQROOM));
+      LWIP_ASSERT("no room for struct ip6_reass_helper", hdrerr == ERR_OK);
+    }
+    iphdr_ptr = (struct ip6_hdr*)((u8_t*)ipr->p->payload - IP6_HLEN);
+    MEMCPY(iphdr_ptr, &ipr->iphdr, IP6_HLEN);
+#else
+    iphdr_ptr = ipr->iphdr;
+#endif
+
+    /* Adjust datagram length by adding header lengths. */
+    ipr->datagram_len += (u16_t)(((u8_t*)ipr->p->payload - (u8_t*)iphdr_ptr)
+                         + IP6_FRAG_HLEN
+                         - IP6_HLEN);
+
+    /* Set payload length in ip header. */
+    iphdr_ptr->_plen = htons(ipr->datagram_len);
+
+    /* Get the first pbuf. */
+    p = ipr->p;
+
+    /* Restore Fragment Header in first pbuf. Mark as "single fragment"
+     * packet. Restore nexth. */
+    frag_hdr = (struct ip6_frag_hdr *) p->payload;
+    frag_hdr->_nexth = ipr->nexth;
+    frag_hdr->reserved = 0;
+    frag_hdr->_fragment_offset = 0;
+    frag_hdr->_identification = 0;
+
+    /* release the sources allocate for the fragment queue entry */
+    if (reassdatagrams == ipr) {
+      /* it was the first in the list */
+      reassdatagrams = ipr->next;
+    } else {
+      /* it wasn't the first, so it must have a valid 'prev' */
+      LWIP_ASSERT("sanity check linked list", ipr_prev != NULL);
+      ipr_prev->next = ipr->next;
+    }
+    memp_free(MEMP_IP6_REASSDATA, ipr);
+
+    /* adjust the number of pbufs currently queued for reassembly. */
+    ip6_reass_pbufcount -= pbuf_clen(p);
+
+    /* Move pbuf back to IPv6 header.
+       This cannot fail since we already checked when receiving this fragment. */
+    if (pbuf_header_force(p, (s16_t)((u8_t*)p->payload - (u8_t*)iphdr_ptr))) {
+      LWIP_ASSERT("ip6_reass: moving p->payload to ip6 header failed\n", 0);
+      pbuf_free(p);
+      return NULL;
+    }
+
+    /* Return the pbuf chain */
+    return p;
+  }
+  /* the datagram is not (yet?) reassembled completely */
+  return NULL;
+
+nullreturn:
+  pbuf_free(p);
+  return NULL;
+}
+
+#endif /* LWIP_IPV6 && LWIP_IPV6_REASS */
+
+#if LWIP_IPV6 && LWIP_IPV6_FRAG
+
+/** Allocate a new struct pbuf_custom_ref */
+static struct pbuf_custom_ref*
+ip6_frag_alloc_pbuf_custom_ref(void)
+{
+  return (struct pbuf_custom_ref*)memp_malloc(MEMP_FRAG_PBUF);
+}
+
+/** Free a struct pbuf_custom_ref */
+static void
+ip6_frag_free_pbuf_custom_ref(struct pbuf_custom_ref* p)
+{
+  LWIP_ASSERT("p != NULL", p != NULL);
+  memp_free(MEMP_FRAG_PBUF, p);
+}
+
+/** Free-callback function to free a 'struct pbuf_custom_ref', called by
+ * pbuf_free. */
+static void
+ip6_frag_free_pbuf_custom(struct pbuf *p)
+{
+  struct pbuf_custom_ref *pcr = (struct pbuf_custom_ref*)p;
+  LWIP_ASSERT("pcr != NULL", pcr != NULL);
+  LWIP_ASSERT("pcr == p", (void*)pcr == (void*)p);
+  if (pcr->original != NULL) {
+    pbuf_free(pcr->original);
+  }
+  ip6_frag_free_pbuf_custom_ref(pcr);
+}
+
+/**
+ * Fragment an IPv6 datagram if too large for the netif or path MTU.
+ *
+ * Chop the datagram in MTU sized chunks and send them in order
+ * by pointing PBUF_REFs into p
+ *
+ * @param p ipv6 packet to send
+ * @param netif the netif on which to send
+ * @param dest destination ipv6 address to which to send
+ *
+ * @return ERR_OK if sent successfully, err_t otherwise
+ */
+err_t
+ip6_frag(struct pbuf *p, struct netif *netif, const ip6_addr_t *dest)
+{
+  struct ip6_hdr *original_ip6hdr;
+  struct ip6_hdr *ip6hdr;
+  struct ip6_frag_hdr * frag_hdr;
+  struct pbuf *rambuf;
+  struct pbuf *newpbuf;
+  static u32_t identification;
+  u16_t nfb;
+  u16_t left, cop;
+  u16_t mtu;
+  u16_t fragment_offset = 0;
+  u16_t last;
+  u16_t poff = IP6_HLEN;
+  u16_t newpbuflen = 0;
+  u16_t left_to_copy;
+
+  identification++;
+
+  original_ip6hdr = (struct ip6_hdr *)p->payload;
+
+  mtu = nd6_get_destination_mtu(dest, netif);
+
+  /* @todo we assume there are no options in the unfragmentable part (IPv6 header). */
+  left = p->tot_len - IP6_HLEN;
+
+  nfb = (mtu - (IP6_HLEN + IP6_FRAG_HLEN)) & IP6_FRAG_OFFSET_MASK;
+
+  while (left) {
+    last = (left <= nfb);
+
+    /* Fill this fragment */
+    cop = last ? left : nfb;
+
+    /* When not using a static buffer, create a chain of pbufs.
+     * The first will be a PBUF_RAM holding the link, IPv6, and Fragment header.
+     * The rest will be PBUF_REFs mirroring the pbuf chain to be fragged,
+     * but limited to the size of an mtu.
+     */
+    rambuf = pbuf_alloc(PBUF_LINK, IP6_HLEN + IP6_FRAG_HLEN, PBUF_RAM);
+    if (rambuf == NULL) {
+      IP6_FRAG_STATS_INC(ip6_frag.memerr);
+      return ERR_MEM;
+    }
+    LWIP_ASSERT("this needs a pbuf in one piece!",
+                (p->len >= (IP6_HLEN + IP6_FRAG_HLEN)));
+    SMEMCPY(rambuf->payload, original_ip6hdr, IP6_HLEN);
+    ip6hdr = (struct ip6_hdr *)rambuf->payload;
+    frag_hdr = (struct ip6_frag_hdr *)((u8_t*)rambuf->payload + IP6_HLEN);
+
+    /* Can just adjust p directly for needed offset. */
+    p->payload = (u8_t *)p->payload + poff;
+    p->len -= poff;
+    p->tot_len -= poff;
+
+    left_to_copy = cop;
+    while (left_to_copy) {
+      struct pbuf_custom_ref *pcr;
+      newpbuflen = (left_to_copy < p->len) ? left_to_copy : p->len;
+      /* Is this pbuf already empty? */
+      if (!newpbuflen) {
+        p = p->next;
+        continue;
+      }
+      pcr = ip6_frag_alloc_pbuf_custom_ref();
+      if (pcr == NULL) {
+        pbuf_free(rambuf);
+        IP6_FRAG_STATS_INC(ip6_frag.memerr);
+        return ERR_MEM;
+      }
+      /* Mirror this pbuf, although we might not need all of it. */
+      newpbuf = pbuf_alloced_custom(PBUF_RAW, newpbuflen, PBUF_REF, &pcr->pc, p->payload, newpbuflen);
+      if (newpbuf == NULL) {
+        ip6_frag_free_pbuf_custom_ref(pcr);
+        pbuf_free(rambuf);
+        IP6_FRAG_STATS_INC(ip6_frag.memerr);
+        return ERR_MEM;
+      }
+      pbuf_ref(p);
+      pcr->original = p;
+      pcr->pc.custom_free_function = ip6_frag_free_pbuf_custom;
+
+      /* Add it to end of rambuf's chain, but using pbuf_cat, not pbuf_chain
+       * so that it is removed when pbuf_dechain is later called on rambuf.
+       */
+      pbuf_cat(rambuf, newpbuf);
+      left_to_copy -= newpbuflen;
+      if (left_to_copy) {
+        p = p->next;
+      }
+    }
+    poff = newpbuflen;
+
+    /* Set headers */
+    frag_hdr->_nexth = original_ip6hdr->_nexth;
+    frag_hdr->reserved = 0;
+    frag_hdr->_fragment_offset = htons((fragment_offset & IP6_FRAG_OFFSET_MASK) | (last ? 0 : IP6_FRAG_MORE_FLAG));
+    frag_hdr->_identification = htonl(identification);
+
+    IP6H_NEXTH_SET(ip6hdr, IP6_NEXTH_FRAGMENT);
+    IP6H_PLEN_SET(ip6hdr, cop + IP6_FRAG_HLEN);
+
+    /* No need for separate header pbuf - we allowed room for it in rambuf
+     * when allocated.
+     */
+    IP6_FRAG_STATS_INC(ip6_frag.xmit);
+    netif->output_ip6(netif, rambuf, dest);
+
+    /* Unfortunately we can't reuse rambuf - the hardware may still be
+     * using the buffer. Instead we free it (and the ensuing chain) and
+     * recreate it next time round the loop. If we're lucky the hardware
+     * will have already sent the packet, the free will really free, and
+     * there will be zero memory penalty.
+     */
+
+    pbuf_free(rambuf);
+    left -= cop;
+    fragment_offset += cop;
+  }
+  return ERR_OK;
+}
+
+#endif /* LWIP_IPV6 && LWIP_IPV6_FRAG */

ext/lwip/src/core/ipv6/mld6.c

@@ -0,0 +1,598 @@
+/**
+ * @file
+ */
+
+/*
+ * Copyright (c) 2010 Inico Technologies Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Ivan Delamer <delamer@inicotech.com>
+ *
+ *
+ * Please coordinate changes and requests with Ivan Delamer
+ * <delamer@inicotech.com>
+ */
+
+/**
+ * @defgroup mld6 MLD6
+ * @ingroup ip6
+ * Multicast listener discovery for IPv6. Aims to be compliant with RFC 2710.
+ * No support for MLDv2.\n
+ * To be called from TCPIP thread
+ */
+
+/* Based on igmp.c implementation of igmp v2 protocol */
+
+#include "lwip/opt.h"
+
+#if LWIP_IPV6 && LWIP_IPV6_MLD  /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/mld6.h"
+#include "lwip/icmp6.h"
+#include "lwip/ip6.h"
+#include "lwip/ip6_addr.h"
+#include "lwip/ip.h"
+#include "lwip/inet_chksum.h"
+#include "lwip/pbuf.h"
+#include "lwip/netif.h"
+#include "lwip/memp.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+
+/*
+ * MLD constants
+ */
+#define MLD6_HL                           1
+#define MLD6_JOIN_DELAYING_MEMBER_TMR_MS  (500)
+
+#define MLD6_GROUP_NON_MEMBER             0
+#define MLD6_GROUP_DELAYING_MEMBER        1
+#define MLD6_GROUP_IDLE_MEMBER            2
+
+
+/* The list of joined groups. */
+static struct mld_group* mld_group_list;
+
+
+/* Forward declarations. */
+static struct mld_group * mld6_new_group(struct netif *ifp, const ip6_addr_t *addr);
+static err_t mld6_free_group(struct mld_group *group);
+static void mld6_delayed_report(struct mld_group *group, u16_t maxresp);
+static void mld6_send(struct mld_group *group, u8_t type);
+
+
+/**
+ * Stop MLD processing on interface
+ *
+ * @param netif network interface on which stop MLD processing
+ */
+err_t
+mld6_stop(struct netif *netif)
+{
+  struct mld_group *group = mld_group_list;
+  struct mld_group *prev  = NULL;
+  struct mld_group *next;
+
+  /* look for groups joined on this interface further down the list */
+  while (group != NULL) {
+    next = group->next;
+    /* is it a group joined on this interface? */
+    if (group->netif == netif) {
+      /* is it the first group of the list? */
+      if (group == mld_group_list) {
+        mld_group_list = next;
+      }
+      /* is there a "previous" group defined? */
+      if (prev != NULL) {
+        prev->next = next;
+      }
+      /* disable the group at the MAC level */
+      if (netif->mld_mac_filter != NULL) {
+        netif->mld_mac_filter(netif, &(group->group_address), MLD6_DEL_MAC_FILTER);
+      }
+      /* free group */
+      memp_free(MEMP_MLD6_GROUP, group);
+    } else {
+      /* change the "previous" */
+      prev = group;
+    }
+    /* move to "next" */
+    group = next;
+  }
+  return ERR_OK;
+}
+
+/**
+ * Report MLD memberships for this interface
+ *
+ * @param netif network interface on which report MLD memberships
+ */
+void
+mld6_report_groups(struct netif *netif)
+{
+  struct mld_group *group = mld_group_list;
+
+  while (group != NULL) {
+    if (group->netif == netif) {
+      mld6_delayed_report(group, MLD6_JOIN_DELAYING_MEMBER_TMR_MS);
+    }
+    group = group->next;
+  }
+}
+
+/**
+ * Search for a group that is joined on a netif
+ *
+ * @param ifp the network interface for which to look
+ * @param addr the group ipv6 address to search for
+ * @return a struct mld_group* if the group has been found,
+ *         NULL if the group wasn't found.
+ */
+struct mld_group *
+mld6_lookfor_group(struct netif *ifp, const ip6_addr_t *addr)
+{
+  struct mld_group *group = mld_group_list;
+
+  while (group != NULL) {
+    if ((group->netif == ifp) && (ip6_addr_cmp(&(group->group_address), addr))) {
+      return group;
+    }
+    group = group->next;
+  }
+
+  return NULL;
+}
+
+
+/**
+ * create a new group
+ *
+ * @param ifp the network interface for which to create
+ * @param addr the new group ipv6
+ * @return a struct mld_group*,
+ *         NULL on memory error.
+ */
+static struct mld_group *
+mld6_new_group(struct netif *ifp, const ip6_addr_t *addr)
+{
+  struct mld_group *group;
+
+  group = (struct mld_group *)memp_malloc(MEMP_MLD6_GROUP);
+  if (group != NULL) {
+    group->netif              = ifp;
+    ip6_addr_set(&(group->group_address), addr);
+    group->timer              = 0; /* Not running */
+    group->group_state        = MLD6_GROUP_IDLE_MEMBER;
+    group->last_reporter_flag = 0;
+    group->use                = 0;
+    group->next               = mld_group_list;
+
+    mld_group_list = group;
+  }
+
+  return group;
+}
+
+/**
+ * Remove a group in the mld_group_list and free
+ *
+ * @param group the group to remove
+ * @return ERR_OK if group was removed from the list, an err_t otherwise
+ */
+static err_t
+mld6_free_group(struct mld_group *group)
+{
+  err_t err = ERR_OK;
+
+  /* Is it the first group? */
+  if (mld_group_list == group) {
+    mld_group_list = group->next;
+  } else {
+    /* look for group further down the list */
+    struct mld_group *tmpGroup;
+    for (tmpGroup = mld_group_list; tmpGroup != NULL; tmpGroup = tmpGroup->next) {
+      if (tmpGroup->next == group) {
+        tmpGroup->next = group->next;
+        break;
+      }
+    }
+    /* Group not find group */
+    if (tmpGroup == NULL) {
+      err = ERR_ARG;
+    }
+  }
+  /* free group */
+  memp_free(MEMP_MLD6_GROUP, group);
+
+  return err;
+}
+
+
+/**
+ * Process an input MLD message. Called by icmp6_input.
+ *
+ * @param p the mld packet, p->payload pointing to the icmpv6 header
+ * @param inp the netif on which this packet was received
+ */
+void
+mld6_input(struct pbuf *p, struct netif *inp)
+{
+  struct mld_header * mld_hdr;
+  struct mld_group* group;
+
+  MLD6_STATS_INC(mld6.recv);
+
+  /* Check that mld header fits in packet. */
+  if (p->len < sizeof(struct mld_header)) {
+    /* @todo debug message */
+    pbuf_free(p);
+    MLD6_STATS_INC(mld6.lenerr);
+    MLD6_STATS_INC(mld6.drop);
+    return;
+  }
+
+  mld_hdr = (struct mld_header *)p->payload;
+
+  switch (mld_hdr->type) {
+  case ICMP6_TYPE_MLQ: /* Multicast listener query. */
+    /* Is it a general query? */
+    if (ip6_addr_isallnodes_linklocal(ip6_current_dest_addr()) &&
+        ip6_addr_isany(&(mld_hdr->multicast_address))) {
+      MLD6_STATS_INC(mld6.rx_general);
+      /* Report all groups, except all nodes group, and if-local groups. */
+      group = mld_group_list;
+      while (group != NULL) {
+        if ((group->netif == inp) &&
+            (!(ip6_addr_ismulticast_iflocal(&(group->group_address)))) &&
+            (!(ip6_addr_isallnodes_linklocal(&(group->group_address))))) {
+          mld6_delayed_report(group, mld_hdr->max_resp_delay);
+        }
+        group = group->next;
+      }
+    } else {
+      /* Have we joined this group?
+       * We use IP6 destination address to have a memory aligned copy.
+       * mld_hdr->multicast_address should be the same. */
+      MLD6_STATS_INC(mld6.rx_group);
+      group = mld6_lookfor_group(inp, ip6_current_dest_addr());
+      if (group != NULL) {
+        /* Schedule a report. */
+        mld6_delayed_report(group, mld_hdr->max_resp_delay);
+      }
+    }
+    break; /* ICMP6_TYPE_MLQ */
+  case ICMP6_TYPE_MLR: /* Multicast listener report. */
+    /* Have we joined this group?
+     * We use IP6 destination address to have a memory aligned copy.
+     * mld_hdr->multicast_address should be the same. */
+    MLD6_STATS_INC(mld6.rx_report);
+    group = mld6_lookfor_group(inp, ip6_current_dest_addr());
+    if (group != NULL) {
+      /* If we are waiting to report, cancel it. */
+      if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) {
+        group->timer = 0; /* stopped */
+        group->group_state = MLD6_GROUP_IDLE_MEMBER;
+        group->last_reporter_flag = 0;
+      }
+    }
+    break; /* ICMP6_TYPE_MLR */
+  case ICMP6_TYPE_MLD: /* Multicast listener done. */
+    /* Do nothing, router will query us. */
+    break; /* ICMP6_TYPE_MLD */
+  default:
+    MLD6_STATS_INC(mld6.proterr);
+    MLD6_STATS_INC(mld6.drop);
+    break;
+  }
+
+  pbuf_free(p);
+}
+
+/**
+ * @ingroup mld6
+ * Join a group on a network interface.
+ *
+ * @param srcaddr ipv6 address of the network interface which should
+ *                join a new group. If IP6_ADDR_ANY, join on all netifs
+ * @param groupaddr the ipv6 address of the group to join
+ * @return ERR_OK if group was joined on the netif(s), an err_t otherwise
+ */
+err_t
+mld6_joingroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
+{
+  err_t         err = ERR_VAL; /* no matching interface */
+  struct netif *netif;
+
+  /* loop through netif's */
+  netif = netif_list;
+  while (netif != NULL) {
+    /* Should we join this interface ? */
+    if (ip6_addr_isany(srcaddr) ||
+        netif_get_ip6_addr_match(netif, srcaddr) >= 0) {
+      err = mld6_joingroup_netif(netif, groupaddr);
+      if (err != ERR_OK) {
+        return err;
+      }
+    }
+
+    /* proceed to next network interface */
+    netif = netif->next;
+  }
+
+  return err;
+}
+
+/**
+ * @ingroup mld6
+ * Join a group on a network interface.
+ *
+ * @param netif the network interface which should join a new group.
+ * @param groupaddr the ipv6 address of the group to join
+ * @return ERR_OK if group was joined on the netif, an err_t otherwise
+ */
+err_t
+mld6_joingroup_netif(struct netif *netif, const ip6_addr_t *groupaddr)
+{
+  struct mld_group *group;
+
+  /* find group or create a new one if not found */
+  group = mld6_lookfor_group(netif, groupaddr);
+
+  if (group == NULL) {
+    /* Joining a new group. Create a new group entry. */
+    group = mld6_new_group(netif, groupaddr);
+    if (group == NULL) {
+      return ERR_MEM;
+    }
+
+    /* Activate this address on the MAC layer. */
+    if (netif->mld_mac_filter != NULL) {
+      netif->mld_mac_filter(netif, groupaddr, MLD6_ADD_MAC_FILTER);
+    }
+
+    /* Report our membership. */
+    MLD6_STATS_INC(mld6.tx_report);
+    mld6_send(group, ICMP6_TYPE_MLR);
+    mld6_delayed_report(group, MLD6_JOIN_DELAYING_MEMBER_TMR_MS);
+  }
+
+  /* Increment group use */
+  group->use++;
+  return ERR_OK;
+}
+
+/**
+ * @ingroup mld6
+ * Leave a group on a network interface.
+ *
+ * @param srcaddr ipv6 address of the network interface which should
+ *                leave the group. If IP6_ISANY, leave on all netifs
+ * @param groupaddr the ipv6 address of the group to leave
+ * @return ERR_OK if group was left on the netif(s), an err_t otherwise
+ */
+err_t
+mld6_leavegroup(const ip6_addr_t *srcaddr, const ip6_addr_t *groupaddr)
+{
+  err_t         err = ERR_VAL; /* no matching interface */
+  struct netif *netif;
+
+  /* loop through netif's */
+  netif = netif_list;
+  while (netif != NULL) {
+    /* Should we leave this interface ? */
+    if (ip6_addr_isany(srcaddr) ||
+        netif_get_ip6_addr_match(netif, srcaddr) >= 0) {
+      err_t res = mld6_leavegroup_netif(netif, groupaddr);
+      if (err != ERR_OK) {
+        /* Store this result if we have not yet gotten a success */
+        err = res;
+      }
+    }
+    /* proceed to next network interface */
+    netif = netif->next;
+  }
+
+  return err;
+}
+
+/**
+ * @ingroup mld6
+ * Leave a group on a network interface.
+ *
+ * @param netif the network interface which should leave the group.
+ * @param groupaddr the ipv6 address of the group to leave
+ * @return ERR_OK if group was left on the netif, an err_t otherwise
+ */
+err_t
+mld6_leavegroup_netif(struct netif *netif, const ip6_addr_t *groupaddr)
+{
+  struct mld_group *group;
+
+  /* find group */
+  group = mld6_lookfor_group(netif, groupaddr);
+
+  if (group != NULL) {
+    /* Leave if there is no other use of the group */
+    if (group->use <= 1) {
+      /* If we are the last reporter for this group */
+      if (group->last_reporter_flag) {
+        MLD6_STATS_INC(mld6.tx_leave);
+        mld6_send(group, ICMP6_TYPE_MLD);
+      }
+
+      /* Disable the group at the MAC level */
+      if (netif->mld_mac_filter != NULL) {
+        netif->mld_mac_filter(netif, groupaddr, MLD6_DEL_MAC_FILTER);
+      }
+
+      /* Free the group */
+      mld6_free_group(group);
+    } else {
+      /* Decrement group use */
+      group->use--;
+    }
+
+    /* Left group */
+    return ERR_OK;
+  }
+
+  /* Group not found */
+  return ERR_VAL;
+}
+
+
+/**
+ * Periodic timer for mld processing. Must be called every
+ * MLD6_TMR_INTERVAL milliseconds (100).
+ *
+ * When a delaying member expires, a membership report is sent.
+ */
+void
+mld6_tmr(void)
+{
+  struct mld_group *group = mld_group_list;
+
+  while (group != NULL) {
+    if (group->timer > 0) {
+      group->timer--;
+      if (group->timer == 0) {
+        /* If the state is MLD6_GROUP_DELAYING_MEMBER then we send a report for this group */
+        if (group->group_state == MLD6_GROUP_DELAYING_MEMBER) {
+          MLD6_STATS_INC(mld6.tx_report);
+          mld6_send(group, ICMP6_TYPE_MLR);
+          group->group_state = MLD6_GROUP_IDLE_MEMBER;
+        }
+      }
+    }
+    group = group->next;
+  }
+}
+
+/**
+ * Schedule a delayed membership report for a group
+ *
+ * @param group the mld_group for which "delaying" membership report
+ *              should be sent
+ * @param maxresp the max resp delay provided in the query
+ */
+static void
+mld6_delayed_report(struct mld_group *group, u16_t maxresp)
+{
+  /* Convert maxresp from milliseconds to tmr ticks */
+  maxresp = maxresp / MLD6_TMR_INTERVAL;
+  if (maxresp == 0) {
+    maxresp = 1;
+  }
+
+#ifdef LWIP_RAND
+  /* Randomize maxresp. (if LWIP_RAND is supported) */
+  maxresp = LWIP_RAND() % maxresp;
+  if (maxresp == 0) {
+    maxresp = 1;
+  }
+#endif /* LWIP_RAND */
+
+  /* Apply timer value if no report has been scheduled already. */
+  if ((group->group_state == MLD6_GROUP_IDLE_MEMBER) ||
+     ((group->group_state == MLD6_GROUP_DELAYING_MEMBER) &&
+      ((group->timer == 0) || (maxresp < group->timer)))) {
+    group->timer = maxresp;
+    group->group_state = MLD6_GROUP_DELAYING_MEMBER;
+  }
+}
+
+/**
+ * Send a MLD message (report or done).
+ *
+ * An IPv6 hop-by-hop options header with a router alert option
+ * is prepended.
+ *
+ * @param group the group to report or quit
+ * @param type ICMP6_TYPE_MLR (report) or ICMP6_TYPE_MLD (done)
+ */
+static void
+mld6_send(struct mld_group *group, u8_t type)
+{
+  struct mld_header * mld_hdr;
+  struct pbuf * p;
+  const ip6_addr_t * src_addr;
+
+  /* Allocate a packet. Size is MLD header + IPv6 Hop-by-hop options header. */
+  p = pbuf_alloc(PBUF_IP, sizeof(struct mld_header) + sizeof(struct ip6_hbh_hdr), PBUF_RAM);
+  if (p == NULL) {
+    MLD6_STATS_INC(mld6.memerr);
+    return;
+  }
+
+  /* Move to make room for Hop-by-hop options header. */
+  if (pbuf_header(p, -IP6_HBH_HLEN)) {
+    pbuf_free(p);
+    MLD6_STATS_INC(mld6.lenerr);
+    return;
+  }
+
+  /* Select our source address. */
+  if (!ip6_addr_isvalid(netif_ip6_addr_state(group->netif, 0))) {
+    /* This is a special case, when we are performing duplicate address detection.
+     * We must join the multicast group, but we don't have a valid address yet. */
+    src_addr = IP6_ADDR_ANY6;
+  } else {
+    /* Use link-local address as source address. */
+    src_addr = netif_ip6_addr(group->netif, 0);
+  }
+
+  /* MLD message header pointer. */
+  mld_hdr = (struct mld_header *)p->payload;
+
+  /* Set fields. */
+  mld_hdr->type = type;
+  mld_hdr->code = 0;
+  mld_hdr->chksum = 0;
+  mld_hdr->max_resp_delay = 0;
+  mld_hdr->reserved = 0;
+  ip6_addr_set(&(mld_hdr->multicast_address), &(group->group_address));
+
+#if CHECKSUM_GEN_ICMP6
+  IF__NETIF_CHECKSUM_ENABLED(group->netif, NETIF_CHECKSUM_GEN_ICMP6) {
+    mld_hdr->chksum = ip6_chksum_pseudo(p, IP6_NEXTH_ICMP6, p->len,
+      src_addr, &(group->group_address));
+  }
+#endif /* CHECKSUM_GEN_ICMP6 */
+
+  /* Add hop-by-hop headers options: router alert with MLD value. */
+  ip6_options_add_hbh_ra(p, IP6_NEXTH_ICMP6, IP6_ROUTER_ALERT_VALUE_MLD);
+
+  /* Send the packet out. */
+  MLD6_STATS_INC(mld6.xmit);
+  ip6_output_if(p, (ip6_addr_isany(src_addr)) ? NULL : src_addr, &(group->group_address),
+      MLD6_HL, 0, IP6_NEXTH_HOPBYHOP, group->netif);
+  pbuf_free(p);
+}
+
+#endif /* LWIP_IPV6 */

ext/lwip/src/core/mem.c

@@ -0,0 +1,777 @@
+/**
+ * @file
+ * Dynamic memory manager
+ *
+ * This is a lightweight replacement for the standard C library malloc().
+ *
+ * If you want to use the standard C library malloc() instead, define
+ * MEM_LIBC_MALLOC to 1 in your lwipopts.h
+ *
+ * To let mem_malloc() use pools (prevents fragmentation and is much faster than
+ * a heap but might waste some memory), define MEM_USE_POOLS to 1, define
+ * MEM_USE_CUSTOM_POOLS to 1 and create a file "lwippools.h" that includes a list
+ * of pools like this (more pools can be added between _START and _END):
+ *
+ * Define three pools with sizes 256, 512, and 1512 bytes
+ * LWIP_MALLOC_MEMPOOL_START
+ * LWIP_MALLOC_MEMPOOL(20, 256)
+ * LWIP_MALLOC_MEMPOOL(10, 512)
+ * LWIP_MALLOC_MEMPOOL(5, 1512)
+ * LWIP_MALLOC_MEMPOOL_END
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *         Simon Goldschmidt
+ *
+ */
+
+#include "lwip/opt.h"
+#include "lwip/def.h"
+#include "lwip/mem.h"
+#include "lwip/sys.h"
+#include "lwip/stats.h"
+#include "lwip/err.h"
+
+#include <string.h>
+
+#if MEM_LIBC_MALLOC || MEM_USE_POOLS
+/** mem_init is not used when using pools instead of a heap or using
+ * C library malloc().
+ */
+void
+mem_init(void)
+{
+}
+
+/** mem_trim is not used when using pools instead of a heap or using
+ * C library malloc(): we can't free part of a pool element and the stack
+ * support mem_trim() to return a different pointer
+ */
+void*
+mem_trim(void *mem, mem_size_t size)
+{
+  LWIP_UNUSED_ARG(size);
+  return mem;
+}
+#endif /* MEM_LIBC_MALLOC || MEM_USE_POOLS */
+
+#if MEM_LIBC_MALLOC
+/* lwIP heap implemented using C library malloc() */
+
+/* in case C library malloc() needs extra protection,
+ * allow these defines to be overridden.
+ */
+#ifndef mem_clib_free
+#define mem_clib_free free
+#endif
+#ifndef mem_clib_malloc
+#define mem_clib_malloc malloc
+#endif
+#ifndef mem_clib_calloc
+#define mem_clib_calloc calloc
+#endif
+
+#if LWIP_STATS && MEM_STATS
+#define MEM_LIBC_STATSHELPER_SIZE LWIP_MEM_ALIGN_SIZE(sizeof(mem_size_t))
+#else
+#define MEM_LIBC_STATSHELPER_SIZE 0
+#endif
+
+/**
+ * Allocate a block of memory with a minimum of 'size' bytes.
+ *
+ * @param size is the minimum size of the requested block in bytes.
+ * @return pointer to allocated memory or NULL if no free memory was found.
+ *
+ * Note that the returned value must always be aligned (as defined by MEM_ALIGNMENT).
+ */
+void *
+mem_malloc(mem_size_t size)
+{
+  void* ret = mem_clib_malloc(size + MEM_LIBC_STATSHELPER_SIZE);
+  if (ret == NULL) {
+    MEM_STATS_INC(err);
+  } else {
+    LWIP_ASSERT("malloc() must return aligned memory", LWIP_MEM_ALIGN(ret) == ret);
+#if LWIP_STATS && MEM_STATS
+    *(mem_size_t*)ret = size;
+    ret = (u8_t*)ret + MEM_LIBC_STATSHELPER_SIZE;
+    MEM_STATS_INC_USED(used, size);
+#endif
+  }
+  return ret;
+}
+
+/** Put memory back on the heap
+ *
+ * @param rmem is the pointer as returned by a previous call to mem_malloc()
+ */
+void
+mem_free(void *rmem)
+{
+  LWIP_ASSERT("rmem != NULL", (rmem != NULL));
+  LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
+#if LWIP_STATS && MEM_STATS
+  rmem = (u8_t*)rmem - MEM_LIBC_STATSHELPER_SIZE;
+  MEM_STATS_DEC_USED(used, *(mem_size_t*)rmem);
+#endif
+  mem_clib_free(rmem);
+}
+
+#elif MEM_USE_POOLS
+
+/* lwIP heap implemented with different sized pools */
+
+/**
+ * Allocate memory: determine the smallest pool that is big enough
+ * to contain an element of 'size' and get an element from that pool.
+ *
+ * @param size the size in bytes of the memory needed
+ * @return a pointer to the allocated memory or NULL if the pool is empty
+ */
+void *
+mem_malloc(mem_size_t size)
+{
+  void *ret;
+  struct memp_malloc_helper *element;
+  memp_t poolnr;
+  mem_size_t required_size = size + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));
+
+  for (poolnr = MEMP_POOL_FIRST; poolnr <= MEMP_POOL_LAST; poolnr = (memp_t)(poolnr + 1)) {
+#if MEM_USE_POOLS_TRY_BIGGER_POOL
+again:
+#endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
+    /* is this pool big enough to hold an element of the required size
+       plus a struct memp_malloc_helper that saves the pool this element came from? */
+    if (required_size <= memp_pools[poolnr]->size) {
+      break;
+    }
+  }
+  if (poolnr > MEMP_POOL_LAST) {
+    LWIP_ASSERT("mem_malloc(): no pool is that big!", 0);
+    MEM_STATS_INC(err);
+    return NULL;
+  }
+  element = (struct memp_malloc_helper*)memp_malloc(poolnr);
+  if (element == NULL) {
+    /* No need to DEBUGF or ASSERT: This error is already
+       taken care of in memp.c */
+#if MEM_USE_POOLS_TRY_BIGGER_POOL
+    /** Try a bigger pool if this one is empty! */
+    if (poolnr < MEMP_POOL_LAST) {
+      poolnr++;
+      goto again;
+    }
+#endif /* MEM_USE_POOLS_TRY_BIGGER_POOL */
+    MEM_STATS_INC(err);
+    return NULL;
+  }
+
+  /* save the pool number this element came from */
+  element->poolnr = poolnr;
+  /* and return a pointer to the memory directly after the struct memp_malloc_helper */
+  ret = (u8_t*)element + LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper));
+
+#if MEMP_OVERFLOW_CHECK || (LWIP_STATS && MEM_STATS)
+  /* truncating to u16_t is safe because struct memp_desc::size is u16_t */
+  element->size = (u16_t)size;
+  MEM_STATS_INC_USED(used, element->size);
+#endif /* MEMP_OVERFLOW_CHECK || (LWIP_STATS && MEM_STATS) */
+#if MEMP_OVERFLOW_CHECK
+  /* initialize unused memory (diff between requested size and selected pool's size) */
+  memset((u8_t*)ret + size, 0xcd, memp_pools[poolnr]->size - size);
+#endif /* MEMP_OVERFLOW_CHECK */
+  return ret;
+}
+
+/**
+ * Free memory previously allocated by mem_malloc. Loads the pool number
+ * and calls memp_free with that pool number to put the element back into
+ * its pool
+ *
+ * @param rmem the memory element to free
+ */
+void
+mem_free(void *rmem)
+{
+  struct memp_malloc_helper *hmem;
+
+  LWIP_ASSERT("rmem != NULL", (rmem != NULL));
+  LWIP_ASSERT("rmem == MEM_ALIGN(rmem)", (rmem == LWIP_MEM_ALIGN(rmem)));
+
+  /* get the original struct memp_malloc_helper */
+  /* cast through void* to get rid of alignment warnings */
+  hmem = (struct memp_malloc_helper*)(void*)((u8_t*)rmem - LWIP_MEM_ALIGN_SIZE(sizeof(struct memp_malloc_helper)));
+
+  LWIP_ASSERT("hmem != NULL", (hmem != NULL));
+  LWIP_ASSERT("hmem == MEM_ALIGN(hmem)", (hmem == LWIP_MEM_ALIGN(hmem)));
+  LWIP_ASSERT("hmem->poolnr < MEMP_MAX", (hmem->poolnr < MEMP_MAX));
+
+  MEM_STATS_DEC_USED(used, hmem->size);
+#if MEMP_OVERFLOW_CHECK
+  {
+     u16_t i;
+     LWIP_ASSERT("MEM_USE_POOLS: invalid chunk size",
+        hmem->size <= memp_pools[hmem->poolnr]->size);
+     /* check that unused memory remained untouched (diff between requested size and selected pool's size) */
+     for (i = hmem->size; i < memp_pools[hmem->poolnr]->size; i++) {
+        u8_t data = *((u8_t*)rmem + i);
+        LWIP_ASSERT("MEM_USE_POOLS: mem overflow detected", data == 0xcd);
+     }
+  }
+#endif /* MEMP_OVERFLOW_CHECK */
+
+  /* and put it in the pool we saved earlier */
+  memp_free(hmem->poolnr, hmem);
+}
+
+#else /* MEM_USE_POOLS */
+/* lwIP replacement for your libc malloc() */
+
+/**
+ * The heap is made up as a list of structs of this type.
+ * This does not have to be aligned since for getting its size,
+ * we only use the macro SIZEOF_STRUCT_MEM, which automatically aligns.
+ */
+struct mem {
+  /** index (-> ram[next]) of the next struct */
+  mem_size_t next;
+  /** index (-> ram[prev]) of the previous struct */
+  mem_size_t prev;
+  /** 1: this area is used; 0: this area is unused */
+  u8_t used;
+};
+
+/** All allocated blocks will be MIN_SIZE bytes big, at least!
+ * MIN_SIZE can be overridden to suit your needs. Smaller values save space,
+ * larger values could prevent too small blocks to fragment the RAM too much. */
+#ifndef MIN_SIZE
+#define MIN_SIZE             12
+#endif /* MIN_SIZE */
+/* some alignment macros: we define them here for better source code layout */
+#define MIN_SIZE_ALIGNED     LWIP_MEM_ALIGN_SIZE(MIN_SIZE)
+#define SIZEOF_STRUCT_MEM    LWIP_MEM_ALIGN_SIZE(sizeof(struct mem))
+#define MEM_SIZE_ALIGNED     LWIP_MEM_ALIGN_SIZE(MEM_SIZE)
+
+/** If you want to relocate the heap to external memory, simply define
+ * LWIP_RAM_HEAP_POINTER as a void-pointer to that location.
+ * If so, make sure the memory at that location is big enough (see below on
+ * how that space is calculated). */
+#ifndef LWIP_RAM_HEAP_POINTER
+/** the heap. we need one struct mem at the end and some room for alignment */
+LWIP_DECLARE_MEMORY_ALIGNED(ram_heap, MEM_SIZE_ALIGNED + (2U*SIZEOF_STRUCT_MEM));
+#define LWIP_RAM_HEAP_POINTER ram_heap
+#endif /* LWIP_RAM_HEAP_POINTER */
+
+/** pointer to the heap (ram_heap): for alignment, ram is now a pointer instead of an array */
+static u8_t *ram;
+/** the last entry, always unused! */
+static struct mem *ram_end;
+/** pointer to the lowest free block, this is used for faster search */
+static struct mem *lfree;
+
+/** concurrent access protection */
+#if !NO_SYS
+static sys_mutex_t mem_mutex;
+#endif
+
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+
+static volatile u8_t mem_free_count;
+
+/* Allow mem_free from other (e.g. interrupt) context */
+#define LWIP_MEM_FREE_DECL_PROTECT()  SYS_ARCH_DECL_PROTECT(lev_free)
+#define LWIP_MEM_FREE_PROTECT()       SYS_ARCH_PROTECT(lev_free)
+#define LWIP_MEM_FREE_UNPROTECT()     SYS_ARCH_UNPROTECT(lev_free)
+#define LWIP_MEM_ALLOC_DECL_PROTECT() SYS_ARCH_DECL_PROTECT(lev_alloc)
+#define LWIP_MEM_ALLOC_PROTECT()      SYS_ARCH_PROTECT(lev_alloc)
+#define LWIP_MEM_ALLOC_UNPROTECT()    SYS_ARCH_UNPROTECT(lev_alloc)
+
+#else /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+
+/* Protect the heap only by using a semaphore */
+#define LWIP_MEM_FREE_DECL_PROTECT()
+#define LWIP_MEM_FREE_PROTECT()    sys_mutex_lock(&mem_mutex)
+#define LWIP_MEM_FREE_UNPROTECT()  sys_mutex_unlock(&mem_mutex)
+/* mem_malloc is protected using semaphore AND LWIP_MEM_ALLOC_PROTECT */
+#define LWIP_MEM_ALLOC_DECL_PROTECT()
+#define LWIP_MEM_ALLOC_PROTECT()
+#define LWIP_MEM_ALLOC_UNPROTECT()
+
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+
+
+/**
+ * "Plug holes" by combining adjacent empty struct mems.
+ * After this function is through, there should not exist
+ * one empty struct mem pointing to another empty struct mem.
+ *
+ * @param mem this points to a struct mem which just has been freed
+ * @internal this function is only called by mem_free() and mem_trim()
+ *
+ * This assumes access to the heap is protected by the calling function
+ * already.
+ */
+static void
+plug_holes(struct mem *mem)
+{
+  struct mem *nmem;
+  struct mem *pmem;
+
+  LWIP_ASSERT("plug_holes: mem >= ram", (u8_t *)mem >= ram);
+  LWIP_ASSERT("plug_holes: mem < ram_end", (u8_t *)mem < (u8_t *)ram_end);
+  LWIP_ASSERT("plug_holes: mem->used == 0", mem->used == 0);
+
+  /* plug hole forward */
+  LWIP_ASSERT("plug_holes: mem->next <= MEM_SIZE_ALIGNED", mem->next <= MEM_SIZE_ALIGNED);
+
+  nmem = (struct mem *)(void *)&ram[mem->next];
+  if (mem != nmem && nmem->used == 0 && (u8_t *)nmem != (u8_t *)ram_end) {
+    /* if mem->next is unused and not end of ram, combine mem and mem->next */
+    if (lfree == nmem) {
+      lfree = mem;
+    }
+    mem->next = nmem->next;
+    ((struct mem *)(void *)&ram[nmem->next])->prev = (mem_size_t)((u8_t *)mem - ram);
+  }
+
+  /* plug hole backward */
+  pmem = (struct mem *)(void *)&ram[mem->prev];
+  if (pmem != mem && pmem->used == 0) {
+    /* if mem->prev is unused, combine mem and mem->prev */
+    if (lfree == mem) {
+      lfree = pmem;
+    }
+    pmem->next = mem->next;
+    ((struct mem *)(void *)&ram[mem->next])->prev = (mem_size_t)((u8_t *)pmem - ram);
+  }
+}
+
+/**
+ * Zero the heap and initialize start, end and lowest-free
+ */
+void
+mem_init(void)
+{
+  struct mem *mem;
+
+  LWIP_ASSERT("Sanity check alignment",
+    (SIZEOF_STRUCT_MEM & (MEM_ALIGNMENT-1)) == 0);
+
+  /* align the heap */
+  ram = (u8_t *)LWIP_MEM_ALIGN(LWIP_RAM_HEAP_POINTER);
+  /* initialize the start of the heap */
+  mem = (struct mem *)(void *)ram;
+  mem->next = MEM_SIZE_ALIGNED;
+  mem->prev = 0;
+  mem->used = 0;
+  /* initialize the end of the heap */
+  ram_end = (struct mem *)(void *)&ram[MEM_SIZE_ALIGNED];
+  ram_end->used = 1;
+  ram_end->next = MEM_SIZE_ALIGNED;
+  ram_end->prev = MEM_SIZE_ALIGNED;
+
+  /* initialize the lowest-free pointer to the start of the heap */
+  lfree = (struct mem *)(void *)ram;
+
+  MEM_STATS_AVAIL(avail, MEM_SIZE_ALIGNED);
+
+  if (sys_mutex_new(&mem_mutex) != ERR_OK) {
+    LWIP_ASSERT("failed to create mem_mutex", 0);
+  }
+}
+
+/**
+ * Put a struct mem back on the heap
+ *
+ * @param rmem is the data portion of a struct mem as returned by a previous
+ *             call to mem_malloc()
+ */
+void
+mem_free(void *rmem)
+{
+  struct mem *mem;
+  LWIP_MEM_FREE_DECL_PROTECT();
+
+  if (rmem == NULL) {
+    LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("mem_free(p == NULL) was called.\n"));
+    return;
+  }
+  LWIP_ASSERT("mem_free: sanity check alignment", (((mem_ptr_t)rmem) & (MEM_ALIGNMENT-1)) == 0);
+
+  LWIP_ASSERT("mem_free: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
+    (u8_t *)rmem < (u8_t *)ram_end);
+
+  if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
+    SYS_ARCH_DECL_PROTECT(lev);
+    LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_free: illegal memory\n"));
+    /* protect mem stats from concurrent access */
+    SYS_ARCH_PROTECT(lev);
+    MEM_STATS_INC(illegal);
+    SYS_ARCH_UNPROTECT(lev);
+    return;
+  }
+  /* protect the heap from concurrent access */
+  LWIP_MEM_FREE_PROTECT();
+  /* Get the corresponding struct mem ... */
+  /* cast through void* to get rid of alignment warnings */
+  mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
+  /* ... which has to be in a used state ... */
+  LWIP_ASSERT("mem_free: mem->used", mem->used);
+  /* ... and is now unused. */
+  mem->used = 0;
+
+  if (mem < lfree) {
+    /* the newly freed struct is now the lowest */
+    lfree = mem;
+  }
+
+  MEM_STATS_DEC_USED(used, mem->next - (mem_size_t)(((u8_t *)mem - ram)));
+
+  /* finally, see if prev or next are free also */
+  plug_holes(mem);
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+  mem_free_count = 1;
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+  LWIP_MEM_FREE_UNPROTECT();
+}
+
+/**
+ * Shrink memory returned by mem_malloc().
+ *
+ * @param rmem pointer to memory allocated by mem_malloc the is to be shrinked
+ * @param newsize required size after shrinking (needs to be smaller than or
+ *                equal to the previous size)
+ * @return for compatibility reasons: is always == rmem, at the moment
+ *         or NULL if newsize is > old size, in which case rmem is NOT touched
+ *         or freed!
+ */
+void *
+mem_trim(void *rmem, mem_size_t newsize)
+{
+  mem_size_t size;
+  mem_size_t ptr, ptr2;
+  struct mem *mem, *mem2;
+  /* use the FREE_PROTECT here: it protects with sem OR SYS_ARCH_PROTECT */
+  LWIP_MEM_FREE_DECL_PROTECT();
+
+  /* Expand the size of the allocated memory region so that we can
+     adjust for alignment. */
+  newsize = LWIP_MEM_ALIGN_SIZE(newsize);
+
+  if (newsize < MIN_SIZE_ALIGNED) {
+    /* every data block must be at least MIN_SIZE_ALIGNED long */
+    newsize = MIN_SIZE_ALIGNED;
+  }
+
+  if (newsize > MEM_SIZE_ALIGNED) {
+    return NULL;
+  }
+
+  LWIP_ASSERT("mem_trim: legal memory", (u8_t *)rmem >= (u8_t *)ram &&
+   (u8_t *)rmem < (u8_t *)ram_end);
+
+  if ((u8_t *)rmem < (u8_t *)ram || (u8_t *)rmem >= (u8_t *)ram_end) {
+    SYS_ARCH_DECL_PROTECT(lev);
+    LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SEVERE, ("mem_trim: illegal memory\n"));
+    /* protect mem stats from concurrent access */
+    SYS_ARCH_PROTECT(lev);
+    MEM_STATS_INC(illegal);
+    SYS_ARCH_UNPROTECT(lev);
+    return rmem;
+  }
+  /* Get the corresponding struct mem ... */
+  /* cast through void* to get rid of alignment warnings */
+  mem = (struct mem *)(void *)((u8_t *)rmem - SIZEOF_STRUCT_MEM);
+  /* ... and its offset pointer */
+  ptr = (mem_size_t)((u8_t *)mem - ram);
+
+  size = mem->next - ptr - SIZEOF_STRUCT_MEM;
+  LWIP_ASSERT("mem_trim can only shrink memory", newsize <= size);
+  if (newsize > size) {
+    /* not supported */
+    return NULL;
+  }
+  if (newsize == size) {
+    /* No change in size, simply return */
+    return rmem;
+  }
+
+  /* protect the heap from concurrent access */
+  LWIP_MEM_FREE_PROTECT();
+
+  mem2 = (struct mem *)(void *)&ram[mem->next];
+  if (mem2->used == 0) {
+    /* The next struct is unused, we can simply move it at little */
+    mem_size_t next;
+    /* remember the old next pointer */
+    next = mem2->next;
+    /* create new struct mem which is moved directly after the shrinked mem */
+    ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
+    if (lfree == mem2) {
+      lfree = (struct mem *)(void *)&ram[ptr2];
+    }
+    mem2 = (struct mem *)(void *)&ram[ptr2];
+    mem2->used = 0;
+    /* restore the next pointer */
+    mem2->next = next;
+    /* link it back to mem */
+    mem2->prev = ptr;
+    /* link mem to it */
+    mem->next = ptr2;
+    /* last thing to restore linked list: as we have moved mem2,
+     * let 'mem2->next->prev' point to mem2 again. but only if mem2->next is not
+     * the end of the heap */
+    if (mem2->next != MEM_SIZE_ALIGNED) {
+      ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
+    }
+    MEM_STATS_DEC_USED(used, (size - newsize));
+    /* no need to plug holes, we've already done that */
+  } else if (newsize + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED <= size) {
+    /* Next struct is used but there's room for another struct mem with
+     * at least MIN_SIZE_ALIGNED of data.
+     * Old size ('size') must be big enough to contain at least 'newsize' plus a struct mem
+     * ('SIZEOF_STRUCT_MEM') with some data ('MIN_SIZE_ALIGNED').
+     * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
+     *       region that couldn't hold data, but when mem->next gets freed,
+     *       the 2 regions would be combined, resulting in more free memory */
+    ptr2 = ptr + SIZEOF_STRUCT_MEM + newsize;
+    mem2 = (struct mem *)(void *)&ram[ptr2];
+    if (mem2 < lfree) {
+      lfree = mem2;
+    }
+    mem2->used = 0;
+    mem2->next = mem->next;
+    mem2->prev = ptr;
+    mem->next = ptr2;
+    if (mem2->next != MEM_SIZE_ALIGNED) {
+      ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
+    }
+    MEM_STATS_DEC_USED(used, (size - newsize));
+    /* the original mem->next is used, so no need to plug holes! */
+  }
+  /* else {
+    next struct mem is used but size between mem and mem2 is not big enough
+    to create another struct mem
+    -> don't do anyhting.
+    -> the remaining space stays unused since it is too small
+  } */
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+  mem_free_count = 1;
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+  LWIP_MEM_FREE_UNPROTECT();
+  return rmem;
+}
+
+/**
+ * Allocate a block of memory with a minimum of 'size' bytes.
+ *
+ * @param size is the minimum size of the requested block in bytes.
+ * @return pointer to allocated memory or NULL if no free memory was found.
+ *
+ * Note that the returned value will always be aligned (as defined by MEM_ALIGNMENT).
+ */
+void *
+mem_malloc(mem_size_t size)
+{
+  mem_size_t ptr, ptr2;
+  struct mem *mem, *mem2;
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+  u8_t local_mem_free_count = 0;
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+  LWIP_MEM_ALLOC_DECL_PROTECT();
+
+  if (size == 0) {
+    return NULL;
+  }
+
+  /* Expand the size of the allocated memory region so that we can
+     adjust for alignment. */
+  size = LWIP_MEM_ALIGN_SIZE(size);
+
+  if (size < MIN_SIZE_ALIGNED) {
+    /* every data block must be at least MIN_SIZE_ALIGNED long */
+    size = MIN_SIZE_ALIGNED;
+  }
+
+  if (size > MEM_SIZE_ALIGNED) {
+    return NULL;
+  }
+
+  /* protect the heap from concurrent access */
+  sys_mutex_lock(&mem_mutex);
+  LWIP_MEM_ALLOC_PROTECT();
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+  /* run as long as a mem_free disturbed mem_malloc or mem_trim */
+  do {
+    local_mem_free_count = 0;
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+
+    /* Scan through the heap searching for a free block that is big enough,
+     * beginning with the lowest free block.
+     */
+    for (ptr = (mem_size_t)((u8_t *)lfree - ram); ptr < MEM_SIZE_ALIGNED - size;
+         ptr = ((struct mem *)(void *)&ram[ptr])->next) {
+      mem = (struct mem *)(void *)&ram[ptr];
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+      mem_free_count = 0;
+      LWIP_MEM_ALLOC_UNPROTECT();
+      /* allow mem_free or mem_trim to run */
+      LWIP_MEM_ALLOC_PROTECT();
+      if (mem_free_count != 0) {
+        /* If mem_free or mem_trim have run, we have to restart since they
+           could have altered our current struct mem. */
+        local_mem_free_count = 1;
+        break;
+      }
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+
+      if ((!mem->used) &&
+          (mem->next - (ptr + SIZEOF_STRUCT_MEM)) >= size) {
+        /* mem is not used and at least perfect fit is possible:
+         * mem->next - (ptr + SIZEOF_STRUCT_MEM) gives us the 'user data size' of mem */
+
+        if (mem->next - (ptr + SIZEOF_STRUCT_MEM) >= (size + SIZEOF_STRUCT_MEM + MIN_SIZE_ALIGNED)) {
+          /* (in addition to the above, we test if another struct mem (SIZEOF_STRUCT_MEM) containing
+           * at least MIN_SIZE_ALIGNED of data also fits in the 'user data space' of 'mem')
+           * -> split large block, create empty remainder,
+           * remainder must be large enough to contain MIN_SIZE_ALIGNED data: if
+           * mem->next - (ptr + (2*SIZEOF_STRUCT_MEM)) == size,
+           * struct mem would fit in but no data between mem2 and mem2->next
+           * @todo we could leave out MIN_SIZE_ALIGNED. We would create an empty
+           *       region that couldn't hold data, but when mem->next gets freed,
+           *       the 2 regions would be combined, resulting in more free memory
+           */
+          ptr2 = ptr + SIZEOF_STRUCT_MEM + size;
+          /* create mem2 struct */
+          mem2 = (struct mem *)(void *)&ram[ptr2];
+          mem2->used = 0;
+          mem2->next = mem->next;
+          mem2->prev = ptr;
+          /* and insert it between mem and mem->next */
+          mem->next = ptr2;
+          mem->used = 1;
+
+          if (mem2->next != MEM_SIZE_ALIGNED) {
+            ((struct mem *)(void *)&ram[mem2->next])->prev = ptr2;
+          }
+          MEM_STATS_INC_USED(used, (size + SIZEOF_STRUCT_MEM));
+        } else {
+          /* (a mem2 struct does no fit into the user data space of mem and mem->next will always
+           * be used at this point: if not we have 2 unused structs in a row, plug_holes should have
+           * take care of this).
+           * -> near fit or exact fit: do not split, no mem2 creation
+           * also can't move mem->next directly behind mem, since mem->next
+           * will always be used at this point!
+           */
+          mem->used = 1;
+          MEM_STATS_INC_USED(used, mem->next - (mem_size_t)((u8_t *)mem - ram));
+        }
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+mem_malloc_adjust_lfree:
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+        if (mem == lfree) {
+          struct mem *cur = lfree;
+          /* Find next free block after mem and update lowest free pointer */
+          while (cur->used && cur != ram_end) {
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+            mem_free_count = 0;
+            LWIP_MEM_ALLOC_UNPROTECT();
+            /* prevent high interrupt latency... */
+            LWIP_MEM_ALLOC_PROTECT();
+            if (mem_free_count != 0) {
+              /* If mem_free or mem_trim have run, we have to restart since they
+                 could have altered our current struct mem or lfree. */
+              goto mem_malloc_adjust_lfree;
+            }
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+            cur = (struct mem *)(void *)&ram[cur->next];
+          }
+          lfree = cur;
+          LWIP_ASSERT("mem_malloc: !lfree->used", ((lfree == ram_end) || (!lfree->used)));
+        }
+        LWIP_MEM_ALLOC_UNPROTECT();
+        sys_mutex_unlock(&mem_mutex);
+        LWIP_ASSERT("mem_malloc: allocated memory not above ram_end.",
+         (mem_ptr_t)mem + SIZEOF_STRUCT_MEM + size <= (mem_ptr_t)ram_end);
+        LWIP_ASSERT("mem_malloc: allocated memory properly aligned.",
+         ((mem_ptr_t)mem + SIZEOF_STRUCT_MEM) % MEM_ALIGNMENT == 0);
+        LWIP_ASSERT("mem_malloc: sanity check alignment",
+          (((mem_ptr_t)mem) & (MEM_ALIGNMENT-1)) == 0);
+
+        return (u8_t *)mem + SIZEOF_STRUCT_MEM;
+      }
+    }
+#if LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT
+    /* if we got interrupted by a mem_free, try again */
+  } while (local_mem_free_count != 0);
+#endif /* LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT */
+  LWIP_DEBUGF(MEM_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("mem_malloc: could not allocate %"S16_F" bytes\n", (s16_t)size));
+  MEM_STATS_INC(err);
+  LWIP_MEM_ALLOC_UNPROTECT();
+  sys_mutex_unlock(&mem_mutex);
+  return NULL;
+}
+
+#endif /* MEM_USE_POOLS */
+
+#if MEM_LIBC_MALLOC && (!LWIP_STATS || !MEM_STATS)
+void *
+mem_calloc(mem_size_t count, mem_size_t size)
+{
+  return mem_clib_calloc(count, size);
+}
+
+#else /* MEM_LIBC_MALLOC && (!LWIP_STATS || !MEM_STATS) */
+/**
+ * Contiguously allocates enough space for count objects that are size bytes
+ * of memory each and returns a pointer to the allocated memory.
+ *
+ * The allocated memory is filled with bytes of value zero.
+ *
+ * @param count number of objects to allocate
+ * @param size size of the objects to allocate
+ * @return pointer to allocated memory / NULL pointer if there is an error
+ */
+void *
+mem_calloc(mem_size_t count, mem_size_t size)
+{
+  void *p;
+
+  /* allocate 'count' objects of size 'size' */
+  p = mem_malloc(count * size);
+  if (p) {
+    /* zero the memory */
+    memset(p, 0, (size_t)count * (size_t)size);
+  }
+  return p;
+}
+#endif /* MEM_LIBC_MALLOC && (!LWIP_STATS || !MEM_STATS) */

ext/lwip/src/core/memp.c

@@ -0,0 +1,501 @@
+/**
+ * @file
+ * Dynamic pool memory manager
+ *
+ * lwIP has dedicated pools for many structures (netconn, protocol control blocks,
+ * packet buffers, ...). All these pools are managed here.
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+/**
+ * @defgroup mempool Memory pools
+ * @ingroup infrastructure
+ * Custom memory pools
+ */
+
+#include "lwip/opt.h"
+
+#include "lwip/memp.h"
+#include "lwip/sys.h"
+#include "lwip/stats.h"
+
+#include <string.h>
+
+/* Make sure we include everything we need for size calculation required by memp_std.h */
+#include "lwip/pbuf.h"
+#include "lwip/raw.h"
+#include "lwip/udp.h"
+#include "lwip/tcp.h"
+#include "lwip/priv/tcp_priv.h"
+#include "lwip/ip4_frag.h"
+#include "lwip/netbuf.h"
+#include "lwip/api.h"
+#include "lwip/priv/tcpip_priv.h"
+#include "lwip/priv/api_msg.h"
+#include "lwip/sockets.h"
+#include "lwip/netifapi.h"
+#include "lwip/etharp.h"
+#include "lwip/igmp.h"
+#include "lwip/timeouts.h"
+/* needed by default MEMP_NUM_SYS_TIMEOUT */
+#include "netif/ppp/ppp_opts.h"
+#include "lwip/netdb.h"
+#include "lwip/dns.h"
+#include "lwip/nd6.h"
+#include "lwip/ip6_frag.h"
+#include "lwip/mld6.h"
+
+
+#define LWIP_MEMPOOL(name,num,size,desc) LWIP_MEMPOOL_DECLARE(name,num,size,desc)
+#include "lwip/priv/memp_std.h"
+
+const struct memp_desc* const memp_pools[MEMP_MAX] = {
+#define LWIP_MEMPOOL(name,num,size,desc) &memp_ ## name,
+#include "lwip/priv/memp_std.h"
+};
+
+#if MEMP_MEM_MALLOC && MEMP_OVERFLOW_CHECK >= 2
+#undef MEMP_OVERFLOW_CHECK
+/* MEMP_OVERFLOW_CHECK >= 2 does not work with MEMP_MEM_MALLOC, use 1 instead */
+#define MEMP_OVERFLOW_CHECK 1
+#endif
+
+#if MEMP_SANITY_CHECK && !MEMP_MEM_MALLOC
+/**
+ * Check that memp-lists don't form a circle, using "Floyd's cycle-finding algorithm".
+ */
+static int
+memp_sanity(const struct memp_desc *desc)
+{
+  struct memp *t, *h;
+
+  t = *desc->tab;
+  if (t != NULL) {
+    for (h = t->next; (t != NULL) && (h != NULL); t = t->next,
+      h = ((h->next != NULL) ? h->next->next : NULL)) {
+      if (t == h) {
+        return 0;
+      }
+    }
+  }
+
+  return 1;
+}
+#endif /* MEMP_SANITY_CHECK && !MEMP_MEM_MALLOC */
+
+#if MEMP_OVERFLOW_CHECK
+/**
+ * Check if a memp element was victim of an overflow
+ * (e.g. the restricted area after it has been altered)
+ *
+ * @param p the memp element to check
+ * @param memp_type the pool p comes from
+ */
+static void
+memp_overflow_check_element_overflow(struct memp *p, const struct memp_desc *desc)
+{
+  u16_t k;
+  u8_t *m;
+#if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
+  m = (u8_t*)p + MEMP_SIZE + desc->size;
+  for (k = 0; k < MEMP_SANITY_REGION_AFTER_ALIGNED; k++) {
+    if (m[k] != 0xcd) {
+      char errstr[128] = "detected memp overflow in pool ";
+      strcat(errstr, desc->desc);
+      LWIP_ASSERT(errstr, 0);
+    }
+  }
+#endif
+}
+
+/**
+ * Check if a memp element was victim of an underflow
+ * (e.g. the restricted area before it has been altered)
+ *
+ * @param p the memp element to check
+ * @param memp_type the pool p comes from
+ */
+static void
+memp_overflow_check_element_underflow(struct memp *p, const struct memp_desc *desc)
+{
+  u16_t k;
+  u8_t *m;
+#if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
+  m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
+  for (k = 0; k < MEMP_SANITY_REGION_BEFORE_ALIGNED; k++) {
+    if (m[k] != 0xcd) {
+      char errstr[128] = "detected memp underflow in pool ";
+      strcat(errstr, desc->desc);
+      LWIP_ASSERT(errstr, 0);
+    }
+  }
+#endif
+}
+
+/**
+ * Initialize the restricted area of on memp element.
+ */
+static void
+memp_overflow_init_element(struct memp *p, const struct memp_desc *desc)
+{
+  u8_t *m;
+#if MEMP_SANITY_REGION_BEFORE_ALIGNED > 0
+  m = (u8_t*)p + MEMP_SIZE - MEMP_SANITY_REGION_BEFORE_ALIGNED;
+  memset(m, 0xcd, MEMP_SANITY_REGION_BEFORE_ALIGNED);
+#endif
+#if MEMP_SANITY_REGION_AFTER_ALIGNED > 0
+  m = (u8_t*)p + MEMP_SIZE + desc->size;
+  memset(m, 0xcd, MEMP_SANITY_REGION_AFTER_ALIGNED);
+#endif
+}
+
+#if MEMP_OVERFLOW_CHECK >= 2
+/**
+ * Do an overflow check for all elements in every pool.
+ *
+ * @see memp_overflow_check_element for a description of the check
+ */
+static void
+memp_overflow_check_all(void)
+{
+  u16_t i, j;
+  struct memp *p;
+  SYS_ARCH_DECL_PROTECT(old_level);
+  SYS_ARCH_PROTECT(old_level);
+
+  for (i = 0; i < MEMP_MAX; ++i) {
+    p = (struct memp *)(size_t)(memp_pools[i]->base);
+    for (j = 0; j < memp_pools[i]->num; ++j) {
+      memp_overflow_check_element_overflow(p, memp_pools[i]);
+      memp_overflow_check_element_underflow(p, memp_pools[i]);
+      p = (struct memp*)(size_t)((u8_t*)p + MEMP_SIZE + memp_pools[i]->size + MEMP_SANITY_REGION_AFTER_ALIGNED);
+    }
+  }
+  SYS_ARCH_UNPROTECT(old_level);
+}
+#endif /* MEMP_OVERFLOW_CHECK >= 2 */
+
+#if !MEMP_MEM_MALLOC
+/**
+ * Initialize the restricted areas of all memp elements in a pool.
+ */
+static void
+memp_overflow_init(const struct memp_desc *desc)
+{
+  u16_t i;
+  struct memp *p;
+
+  p = (struct memp *)(size_t)(desc->base);
+  for (i = 0; i < desc->num; ++i) {
+    memp_overflow_init_element(p, desc);
+    p = (struct memp*)(size_t)((u8_t*)p + MEMP_SIZE + desc->size + MEMP_SANITY_REGION_AFTER_ALIGNED);
+  }
+}
+#endif /* !MEMP_MEM_MALLOC */
+#endif /* MEMP_OVERFLOW_CHECK */
+
+/**
+ * Initialize custom memory pool.
+ * Related functions: memp_malloc_pool, memp_free_pool
+ *
+ * @param desc pool to initialize
+ */
+void
+memp_init_pool(const struct memp_desc *desc)
+{
+#if MEMP_MEM_MALLOC
+  LWIP_UNUSED_ARG(desc);
+#else
+  int i;
+  struct memp *memp;
+
+  *desc->tab = NULL;
+  memp = (struct memp*)LWIP_MEM_ALIGN(desc->base);
+  /* create a linked list of memp elements */
+  for (i = 0; i < desc->num; ++i) {
+    memp->next = *desc->tab;
+    *desc->tab = memp;
+   /* cast through void* to get rid of alignment warnings */
+   memp = (struct memp *)(void *)((u8_t *)memp + MEMP_SIZE + desc->size
+#if MEMP_OVERFLOW_CHECK
+      + MEMP_SANITY_REGION_AFTER_ALIGNED
+#endif
+    );
+  }
+
+#if MEMP_OVERFLOW_CHECK
+  memp_overflow_init(desc);
+#endif /* MEMP_OVERFLOW_CHECK */
+#endif /* !MEMP_MEM_MALLOC */
+
+#if MEMP_STATS
+#if !MEMP_MEM_MALLOC
+  desc->stats->avail = desc->num;
+#endif /* !MEMP_MEM_MALLOC */
+
+#if defined(LWIP_DEBUG) || LWIP_STATS_DISPLAY
+  desc->stats->name  = desc->desc;
+#endif /* defined(LWIP_DEBUG) || LWIP_STATS_DISPLAY */
+#endif /* MEMP_STATS */
+}
+
+/**
+ * Initializes lwIP built-in pools.
+ * Related functions: memp_malloc, memp_free
+ *
+ * Carves out memp_memory into linked lists for each pool-type.
+ */
+void
+memp_init(void)
+{
+  u16_t i;
+
+  /* for every pool: */
+  for (i = 0; i < LWIP_ARRAYSIZE(memp_pools); i++) {
+    memp_init_pool(memp_pools[i]);
+
+#if LWIP_STATS && MEMP_STATS
+    lwip_stats.memp[i] = memp_pools[i]->stats;
+#endif
+  }
+
+#if MEMP_OVERFLOW_CHECK >= 2
+  /* check everything a first time to see if it worked */
+  memp_overflow_check_all();
+#endif /* MEMP_OVERFLOW_CHECK >= 2 */
+}
+
+static void*
+#if !MEMP_OVERFLOW_CHECK
+do_memp_malloc_pool(const struct memp_desc *desc)
+#else
+do_memp_malloc_pool_fn(const struct memp_desc *desc, const char* file, const int line)
+#endif
+{
+  struct memp *memp;
+  SYS_ARCH_DECL_PROTECT(old_level);
+
+#if MEMP_MEM_MALLOC
+  memp = (struct memp *)mem_malloc(MEMP_SIZE + MEMP_ALIGN_SIZE(desc->size));
+  SYS_ARCH_PROTECT(old_level);
+#else /* MEMP_MEM_MALLOC */
+  SYS_ARCH_PROTECT(old_level);
+
+  memp = *desc->tab;
+
+#if MEMP_OVERFLOW_CHECK == 1
+  memp_overflow_check_element_overflow(memp, desc);
+  memp_overflow_check_element_underflow(memp, desc);
+#endif /* MEMP_OVERFLOW_CHECK */
+#endif /* MEMP_MEM_MALLOC */
+
+  if (memp != NULL) {
+#if !MEMP_MEM_MALLOC
+    *desc->tab = memp->next;
+#if MEMP_OVERFLOW_CHECK
+    memp->next = NULL;
+#endif /* MEMP_OVERFLOW_CHECK */
+#endif /* !MEMP_MEM_MALLOC */
+#if MEMP_OVERFLOW_CHECK
+    memp->file = file;
+    memp->line = line;
+#if MEMP_MEM_MALLOC
+    memp_overflow_init_element(memp, desc);
+#endif /* MEMP_MEM_MALLOC */
+#endif /* MEMP_OVERFLOW_CHECK */
+    LWIP_ASSERT("memp_malloc: memp properly aligned",
+                ((mem_ptr_t)memp % MEM_ALIGNMENT) == 0);
+#if MEMP_STATS
+    desc->stats->used++;
+    if (desc->stats->used > desc->stats->max) {
+      desc->stats->max = desc->stats->used;
+    }
+#endif
+    SYS_ARCH_UNPROTECT(old_level);
+    /* cast through u8_t* to get rid of alignment warnings */
+    return ((u8_t*)memp + MEMP_SIZE);
+  } else {
+    LWIP_DEBUGF(MEMP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("memp_malloc: out of memory in pool %s\n", desc->desc));
+#if MEMP_STATS
+    desc->stats->err++;
+#endif
+  }
+
+  SYS_ARCH_UNPROTECT(old_level);
+  return NULL;
+}
+
+/**
+ * Get an element from a custom pool.
+ *
+ * @param desc the pool to get an element from
+ *
+ * @return a pointer to the allocated memory or a NULL pointer on error
+ */
+void *
+#if !MEMP_OVERFLOW_CHECK
+memp_malloc_pool(const struct memp_desc *desc)
+#else
+memp_malloc_pool_fn(const struct memp_desc *desc, const char* file, const int line)
+#endif
+{
+  LWIP_ASSERT("invalid pool desc", desc != NULL);
+  if (desc == NULL) {
+    return NULL;
+  }
+
+#if !MEMP_OVERFLOW_CHECK
+  return do_memp_malloc_pool(desc);
+#else
+  return do_memp_malloc_pool_fn(desc, file, line);
+#endif
+}
+
+/**
+ * Get an element from a specific pool.
+ *
+ * @param type the pool to get an element from
+ *
+ * @return a pointer to the allocated memory or a NULL pointer on error
+ */
+void *
+#if !MEMP_OVERFLOW_CHECK
+memp_malloc(memp_t type)
+#else
+memp_malloc_fn(memp_t type, const char* file, const int line)
+#endif
+{
+  void *memp;
+  LWIP_ERROR("memp_malloc: type < MEMP_MAX", (type < MEMP_MAX), return NULL;);
+
+#if MEMP_OVERFLOW_CHECK >= 2
+  memp_overflow_check_all();
+#endif /* MEMP_OVERFLOW_CHECK >= 2 */
+
+#if !MEMP_OVERFLOW_CHECK
+  memp = do_memp_malloc_pool(memp_pools[type]);
+#else
+  memp = do_memp_malloc_pool_fn(memp_pools[type], file, line);
+#endif
+
+  return memp;
+}
+
+static void
+do_memp_free_pool(const struct memp_desc* desc, void *mem)
+{
+  struct memp *memp;
+  SYS_ARCH_DECL_PROTECT(old_level);
+
+  LWIP_ASSERT("memp_free: mem properly aligned",
+                ((mem_ptr_t)mem % MEM_ALIGNMENT) == 0);
+
+  /* cast through void* to get rid of alignment warnings */
+  memp = (struct memp *)(void *)((u8_t*)mem - MEMP_SIZE);
+
+  SYS_ARCH_PROTECT(old_level);
+
+#if MEMP_OVERFLOW_CHECK == 1
+  memp_overflow_check_element_overflow(memp, desc);
+  memp_overflow_check_element_underflow(memp, desc);
+#endif /* MEMP_OVERFLOW_CHECK */
+
+#if MEMP_STATS
+  desc->stats->used--;
+#endif
+
+#if MEMP_MEM_MALLOC
+  LWIP_UNUSED_ARG(desc);
+  SYS_ARCH_UNPROTECT(old_level);
+  mem_free(memp);
+#else /* MEMP_MEM_MALLOC */
+  memp->next = *desc->tab;
+  *desc->tab = memp;
+
+#if MEMP_SANITY_CHECK
+  LWIP_ASSERT("memp sanity", memp_sanity(desc));
+#endif /* MEMP_SANITY_CHECK */
+
+  SYS_ARCH_UNPROTECT(old_level);
+#endif /* !MEMP_MEM_MALLOC */
+}
+
+/**
+ * Put a custom pool element back into its pool.
+ *
+ * @param desc the pool where to put mem
+ * @param mem the memp element to free
+ */
+void
+memp_free_pool(const struct memp_desc* desc, void *mem)
+{
+  LWIP_ASSERT("invalid pool desc", desc != NULL);
+  if ((desc == NULL) || (mem == NULL)) {
+    return;
+  }
+
+  do_memp_free_pool(desc, mem);
+}
+
+/**
+ * Put an element back into its pool.
+ *
+ * @param type the pool where to put mem
+ * @param mem the memp element to free
+ */
+void
+memp_free(memp_t type, void *mem)
+{
+#ifdef LWIP_HOOK_MEMP_AVAILABLE
+  struct memp *old_first;
+#endif
+
+  LWIP_ERROR("memp_free: type < MEMP_MAX", (type < MEMP_MAX), return;);
+
+#if MEMP_OVERFLOW_CHECK >= 2
+  memp_overflow_check_all();
+#endif /* MEMP_OVERFLOW_CHECK >= 2 */
+
+#ifdef LWIP_HOOK_MEMP_AVAILABLE
+  old_first = memp_pools[type].tab;
+#endif
+
+  do_memp_free_pool(memp_pools[type], mem);
+
+#ifdef LWIP_HOOK_MEMP_AVAILABLE
+  if (old_first == NULL) {
+    LWIP_HOOK_MEMP_AVAILABLE(type);
+  }
+#endif
+}

ext/lwip/src/core/raw.c

@@ -0,0 +1,504 @@
+/**
+ * @file
+ * Implementation of raw protocol PCBs for low-level handling of
+ * different types of protocols besides (or overriding) those
+ * already available in lwIP.\n
+ * See also @ref raw_raw
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+/**
+ * @defgroup raw_api RAW API
+ * @ingroup callbackstyle_api
+ * @verbinclude "rawapi.txt"
+ */
+
+/**
+ * @defgroup raw_raw RAW
+ * @ingroup raw_api
+ * Implementation of raw protocol PCBs for low-level handling of
+ * different types of protocols besides (or overriding) those
+ * already available in lwIP.\n
+ * @see @ref raw_api
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_RAW /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/def.h"
+#include "lwip/memp.h"
+#include "lwip/ip_addr.h"
+#include "lwip/netif.h"
+#include "lwip/raw.h"
+#include "lwip/stats.h"
+#include "lwip/ip6.h"
+#include "lwip/ip6_addr.h"
+#include "lwip/inet_chksum.h"
+
+#include <string.h>
+
+/** The list of RAW PCBs */
+static struct raw_pcb *raw_pcbs;
+
+static u8_t
+raw_input_match(struct raw_pcb *pcb, u8_t broadcast)
+{
+  LWIP_UNUSED_ARG(broadcast); /* in IPv6 only case */
+
+#if LWIP_IPV4 && LWIP_IPV6
+  /* Dual-stack: PCBs listening to any IP type also listen to any IP address */
+  if (IP_IS_ANY_TYPE_VAL(pcb->local_ip)) {
+#if IP_SOF_BROADCAST_RECV
+    if ((broadcast != 0) && !ip_get_option(pcb, SOF_BROADCAST)) {
+      return 0;
+    }
+#endif /* IP_SOF_BROADCAST_RECV */
+    return 1;
+  }
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+  
+  /* Only need to check PCB if incoming IP version matches PCB IP version */
+  if (IP_ADDR_PCB_VERSION_MATCH_EXACT(pcb, ip_current_dest_addr())) {
+#if LWIP_IPV4
+    /* Special case: IPv4 broadcast: receive all broadcasts
+     * Note: broadcast variable can only be 1 if it is an IPv4 broadcast */
+    if (broadcast != 0) {
+#if IP_SOF_BROADCAST_RECV
+      if (ip_get_option(pcb, SOF_BROADCAST))
+#endif /* IP_SOF_BROADCAST_RECV */
+      {
+        if (ip4_addr_isany(ip_2_ip4(&pcb->local_ip))) {
+          return 1;
+        }
+      }
+    } else
+#endif /* LWIP_IPV4 */
+    /* Handle IPv4 and IPv6: catch all or exact match */
+    if (ip_addr_isany(&pcb->local_ip) ||
+       ip_addr_cmp(&pcb->local_ip, ip_current_dest_addr())) {
+      return 1;
+    }
+  }
+  
+  return 0;
+}
+
+/**
+ * Determine if in incoming IP packet is covered by a RAW PCB
+ * and if so, pass it to a user-provided receive callback function.
+ *
+ * Given an incoming IP datagram (as a chain of pbufs) this function
+ * finds a corresponding RAW PCB and calls the corresponding receive
+ * callback function.
+ *
+ * @param p pbuf to be demultiplexed to a RAW PCB.
+ * @param inp network interface on which the datagram was received.
+ * @return - 1 if the packet has been eaten by a RAW PCB receive
+ *           callback function. The caller MAY NOT not reference the
+ *           packet any longer, and MAY NOT call pbuf_free().
+ * @return - 0 if packet is not eaten (pbuf is still referenced by the
+ *           caller).
+ *
+ */
+u8_t
+raw_input(struct pbuf *p, struct netif *inp)
+{
+  struct raw_pcb *pcb, *prev;
+  s16_t proto;
+  u8_t eaten = 0;
+  u8_t broadcast = ip_addr_isbroadcast(ip_current_dest_addr(), ip_current_netif());
+
+  LWIP_UNUSED_ARG(inp);
+
+#if LWIP_IPV6
+#if LWIP_IPV4
+  if (IP_HDR_GET_VERSION(p->payload) == 6)
+#endif /* LWIP_IPV4 */
+  {
+    struct ip6_hdr *ip6hdr = (struct ip6_hdr *)p->payload;
+    proto = IP6H_NEXTH(ip6hdr);
+  }
+#if LWIP_IPV4
+  else
+#endif /* LWIP_IPV4 */
+#endif /* LWIP_IPV6 */
+#if LWIP_IPV4
+  {
+    proto = IPH_PROTO((struct ip_hdr *)p->payload);
+  }
+#endif /* LWIP_IPV4 */
+
+  prev = NULL;
+  pcb = raw_pcbs;
+  /* loop through all raw pcbs until the packet is eaten by one */
+  /* this allows multiple pcbs to match against the packet by design */
+  while ((eaten == 0) && (pcb != NULL)) {
+    if ((pcb->protocol == proto) && raw_input_match(pcb, broadcast)) {
+      /* receive callback function available? */
+      if (pcb->recv != NULL) {
+#ifndef LWIP_NOASSERT
+        void* old_payload = p->payload;
+#endif
+        /* the receive callback function did not eat the packet? */
+        eaten = pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr());
+        if (eaten != 0) {
+          /* receive function ate the packet */
+          p = NULL;
+          eaten = 1;
+          if (prev != NULL) {
+          /* move the pcb to the front of raw_pcbs so that is
+             found faster next time */
+            prev->next = pcb->next;
+            pcb->next = raw_pcbs;
+            raw_pcbs = pcb;
+          }
+        } else {
+          /* sanity-check that the receive callback did not alter the pbuf */
+          LWIP_ASSERT("raw pcb recv callback altered pbuf payload pointer without eating packet",
+            p->payload == old_payload);
+        }
+      }
+      /* no receive callback function was set for this raw PCB */
+    }
+    /* drop the packet */
+    prev = pcb;
+    pcb = pcb->next;
+  }
+  return eaten;
+}
+
+/**
+ * @ingroup raw_raw
+ * Bind a RAW PCB.
+ *
+ * @param pcb RAW PCB to be bound with a local address ipaddr.
+ * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to
+ * bind to all local interfaces.
+ *
+ * @return lwIP error code.
+ * - ERR_OK. Successful. No error occurred.
+ * - ERR_USE. The specified IP address is already bound to by
+ * another RAW PCB.
+ *
+ * @see raw_disconnect()
+ */
+err_t
+raw_bind(struct raw_pcb *pcb, const ip_addr_t *ipaddr)
+{
+  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH_EXACT(pcb, ipaddr)) {
+    return ERR_VAL;
+  }
+  ip_addr_set_ipaddr(&pcb->local_ip, ipaddr);
+  return ERR_OK;
+}
+
+/**
+ * @ingroup raw_raw
+ * Connect an RAW PCB. This function is required by upper layers
+ * of lwip. Using the raw api you could use raw_sendto() instead
+ *
+ * This will associate the RAW PCB with the remote address.
+ *
+ * @param pcb RAW PCB to be connected with remote address ipaddr and port.
+ * @param ipaddr remote IP address to connect with.
+ *
+ * @return lwIP error code
+ *
+ * @see raw_disconnect() and raw_sendto()
+ */
+err_t
+raw_connect(struct raw_pcb *pcb, const ip_addr_t *ipaddr)
+{
+  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH_EXACT(pcb, ipaddr)) {
+    return ERR_VAL;
+  }
+  ip_addr_set_ipaddr(&pcb->remote_ip, ipaddr);
+  return ERR_OK;
+}
+
+/**
+ * @ingroup raw_raw
+ * Set the callback function for received packets that match the
+ * raw PCB's protocol and binding.
+ *
+ * The callback function MUST either
+ * - eat the packet by calling pbuf_free() and returning non-zero. The
+ *   packet will not be passed to other raw PCBs or other protocol layers.
+ * - not free the packet, and return zero. The packet will be matched
+ *   against further PCBs and/or forwarded to another protocol layers.
+ *
+ * @return non-zero if the packet was free()d, zero if the packet remains
+ * available for others.
+ */
+void
+raw_recv(struct raw_pcb *pcb, raw_recv_fn recv, void *recv_arg)
+{
+  /* remember recv() callback and user data */
+  pcb->recv = recv;
+  pcb->recv_arg = recv_arg;
+}
+
+/**
+ * @ingroup raw_raw
+ * Send the raw IP packet to the given address. Note that actually you cannot
+ * modify the IP headers (this is inconsistent with the receive callback where
+ * you actually get the IP headers), you can only specify the IP payload here.
+ * It requires some more changes in lwIP. (there will be a raw_send() function
+ * then.)
+ *
+ * @param pcb the raw pcb which to send
+ * @param p the IP payload to send
+ * @param ipaddr the destination address of the IP packet
+ *
+ */
+err_t
+raw_sendto(struct raw_pcb *pcb, struct pbuf *p, const ip_addr_t *ipaddr)
+{
+  err_t err;
+  struct netif *netif;
+  const ip_addr_t *src_ip;
+  struct pbuf *q; /* q will be sent down the stack */
+  s16_t header_size;
+  const ip_addr_t *dst_ip = ipaddr;
+
+  if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
+    return ERR_VAL;
+  }
+
+  LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_sendto\n"));
+
+  header_size = (
+#if LWIP_IPV4 && LWIP_IPV6
+    IP_IS_V6(ipaddr) ? IP6_HLEN : IP_HLEN);
+#elif LWIP_IPV4
+    IP_HLEN);
+#else
+    IP6_HLEN);
+#endif
+
+  /* not enough space to add an IP header to first pbuf in given p chain? */
+  if (pbuf_header(p, header_size)) {
+    /* allocate header in new pbuf */
+    q = pbuf_alloc(PBUF_IP, 0, PBUF_RAM);
+    /* new header pbuf could not be allocated? */
+    if (q == NULL) {
+      LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("raw_sendto: could not allocate header\n"));
+      return ERR_MEM;
+    }
+    if (p->tot_len != 0) {
+      /* chain header q in front of given pbuf p */
+      pbuf_chain(q, p);
+    }
+    /* { first pbuf q points to header pbuf } */
+    LWIP_DEBUGF(RAW_DEBUG, ("raw_sendto: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
+  } else {
+    /* first pbuf q equals given pbuf */
+    q = p;
+    if (pbuf_header(q, -header_size)) {
+      LWIP_ASSERT("Can't restore header we just removed!", 0);
+      return ERR_MEM;
+    }
+  }
+
+  netif = ip_route(&pcb->local_ip, dst_ip);
+  if (netif == NULL) {
+    LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: No route to "));
+    ip_addr_debug_print(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, dst_ip);
+    /* free any temporary header pbuf allocated by pbuf_header() */
+    if (q != p) {
+      pbuf_free(q);
+    }
+    return ERR_RTE;
+  }
+
+#if IP_SOF_BROADCAST
+  if (IP_IS_V4(ipaddr))
+  {
+    /* broadcast filter? */
+    if (!ip_get_option(pcb, SOF_BROADCAST) && ip_addr_isbroadcast(ipaddr, netif)) {
+      LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_LEVEL_WARNING, ("raw_sendto: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
+      /* free any temporary header pbuf allocated by pbuf_header() */
+      if (q != p) {
+        pbuf_free(q);
+      }
+      return ERR_VAL;
+    }
+  }
+#endif /* IP_SOF_BROADCAST */
+
+  if (ip_addr_isany(&pcb->local_ip)) {
+    /* use outgoing network interface IP address as source address */
+    src_ip = ip_netif_get_local_ip(netif, dst_ip);
+#if LWIP_IPV6
+    if (src_ip == NULL) {
+      if (q != p) {
+        pbuf_free(q);
+      }
+      return ERR_RTE;
+    }
+#endif /* LWIP_IPV6 */
+  } else {
+    /* use RAW PCB local IP address as source address */
+    src_ip = &pcb->local_ip;
+  }
+
+#if LWIP_IPV6
+  /* If requested, based on the IPV6_CHECKSUM socket option per RFC3542,
+     compute the checksum and update the checksum in the payload. */
+  if (IP_IS_V6(dst_ip) && pcb->chksum_reqd) {
+    u16_t chksum = ip6_chksum_pseudo(p, pcb->protocol, p->tot_len, ip_2_ip6(src_ip), ip_2_ip6(dst_ip));
+    LWIP_ASSERT("Checksum must fit into first pbuf", p->len >= (pcb->chksum_offset + 2));
+    SMEMCPY(((u8_t *)p->payload) + pcb->chksum_offset, &chksum, sizeof(u16_t));
+  }
+#endif
+
+  NETIF_SET_HWADDRHINT(netif, &pcb->addr_hint);
+  err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, pcb->protocol, netif);
+  NETIF_SET_HWADDRHINT(netif, NULL);
+
+  /* did we chain a header earlier? */
+  if (q != p) {
+    /* free the header */
+    pbuf_free(q);
+  }
+  return err;
+}
+
+/**
+ * @ingroup raw_raw
+ * Send the raw IP packet to the address given by raw_connect()
+ *
+ * @param pcb the raw pcb which to send
+ * @param p the IP payload to send
+ *
+ */
+err_t
+raw_send(struct raw_pcb *pcb, struct pbuf *p)
+{
+  return raw_sendto(pcb, p, &pcb->remote_ip);
+}
+
+/**
+ * @ingroup raw_raw
+ * Remove an RAW PCB.
+ *
+ * @param pcb RAW PCB to be removed. The PCB is removed from the list of
+ * RAW PCB's and the data structure is freed from memory.
+ *
+ * @see raw_new()
+ */
+void
+raw_remove(struct raw_pcb *pcb)
+{
+  struct raw_pcb *pcb2;
+  /* pcb to be removed is first in list? */
+  if (raw_pcbs == pcb) {
+    /* make list start at 2nd pcb */
+    raw_pcbs = raw_pcbs->next;
+    /* pcb not 1st in list */
+  } else {
+    for (pcb2 = raw_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
+      /* find pcb in raw_pcbs list */
+      if (pcb2->next != NULL && pcb2->next == pcb) {
+        /* remove pcb from list */
+        pcb2->next = pcb->next;
+        break;
+      }
+    }
+  }
+  memp_free(MEMP_RAW_PCB, pcb);
+}
+
+/**
+ * @ingroup raw_raw
+ * Create a RAW PCB.
+ *
+ * @return The RAW PCB which was created. NULL if the PCB data structure
+ * could not be allocated.
+ *
+ * @param proto the protocol number of the IPs payload (e.g. IP_PROTO_ICMP)
+ *
+ * @see raw_remove()
+ */
+struct raw_pcb *
+raw_new(u8_t proto)
+{
+  struct raw_pcb *pcb;
+
+  LWIP_DEBUGF(RAW_DEBUG | LWIP_DBG_TRACE, ("raw_new\n"));
+
+  pcb = (struct raw_pcb *)memp_malloc(MEMP_RAW_PCB);
+  /* could allocate RAW PCB? */
+  if (pcb != NULL) {
+    /* initialize PCB to all zeroes */
+    memset(pcb, 0, sizeof(struct raw_pcb));
+    pcb->protocol = proto;
+    pcb->ttl = RAW_TTL;
+    pcb->next = raw_pcbs;
+    raw_pcbs = pcb;
+  }
+  return pcb;
+}
+
+/**
+ * @ingroup raw_raw
+ * Create a RAW PCB for specific IP type.
+ *
+ * @return The RAW PCB which was created. NULL if the PCB data structure
+ * could not be allocated.
+ *
+ * @param type IP address type, see IPADDR_TYPE_XX definitions.
+ * @param proto the protocol number (next header) of the IPv6 packet payload
+ *              (e.g. IP6_NEXTH_ICMP6)
+ *
+ * @see raw_remove()
+ */
+struct raw_pcb *
+raw_new_ip_type(u8_t type, u8_t proto)
+{
+  struct raw_pcb *pcb;
+  pcb = raw_new(proto);
+#if LWIP_IPV4 && LWIP_IPV6
+  if (pcb != NULL) {
+    IP_SET_TYPE_VAL(pcb->local_ip,  type);
+    IP_SET_TYPE_VAL(pcb->remote_ip, type);
+  }
+#else /* LWIP_IPV4 && LWIP_IPV6 */
+  LWIP_UNUSED_ARG(type);
+#endif /* LWIP_IPV4 && LWIP_IPV6 */
+  return pcb;
+}
+
+#endif /* LWIP_RAW */

ext/lwip/src/core/stats.c

@@ -0,0 +1,169 @@
+/**
+ * @file
+ * Statistics module
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_STATS /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/def.h"
+#include "lwip/stats.h"
+#include "lwip/mem.h"
+#include "lwip/debug.h"
+
+#include <string.h>
+
+struct stats_ lwip_stats;
+
+void
+stats_init(void)
+{
+#ifdef LWIP_DEBUG
+#if MEM_STATS
+  lwip_stats.mem.name = "MEM";
+#endif /* MEM_STATS */
+#endif /* LWIP_DEBUG */
+}
+
+#if LWIP_STATS_DISPLAY
+void
+stats_display_proto(struct stats_proto *proto, const char *name)
+{
+  LWIP_PLATFORM_DIAG(("\n%s\n\t", name));
+  LWIP_PLATFORM_DIAG(("xmit: %"STAT_COUNTER_F"\n\t", proto->xmit));
+  LWIP_PLATFORM_DIAG(("recv: %"STAT_COUNTER_F"\n\t", proto->recv));
+  LWIP_PLATFORM_DIAG(("fw: %"STAT_COUNTER_F"\n\t", proto->fw));
+  LWIP_PLATFORM_DIAG(("drop: %"STAT_COUNTER_F"\n\t", proto->drop));
+  LWIP_PLATFORM_DIAG(("chkerr: %"STAT_COUNTER_F"\n\t", proto->chkerr));
+  LWIP_PLATFORM_DIAG(("lenerr: %"STAT_COUNTER_F"\n\t", proto->lenerr));
+  LWIP_PLATFORM_DIAG(("memerr: %"STAT_COUNTER_F"\n\t", proto->memerr));
+  LWIP_PLATFORM_DIAG(("rterr: %"STAT_COUNTER_F"\n\t", proto->rterr));
+  LWIP_PLATFORM_DIAG(("proterr: %"STAT_COUNTER_F"\n\t", proto->proterr));
+  LWIP_PLATFORM_DIAG(("opterr: %"STAT_COUNTER_F"\n\t", proto->opterr));
+  LWIP_PLATFORM_DIAG(("err: %"STAT_COUNTER_F"\n\t", proto->err));
+  LWIP_PLATFORM_DIAG(("cachehit: %"STAT_COUNTER_F"\n", proto->cachehit));
+}
+
+#if IGMP_STATS || MLD6_STATS
+void
+stats_display_igmp(struct stats_igmp *igmp, const char *name)
+{
+  LWIP_PLATFORM_DIAG(("\n%s\n\t", name));
+  LWIP_PLATFORM_DIAG(("xmit: %"STAT_COUNTER_F"\n\t", igmp->xmit));
+  LWIP_PLATFORM_DIAG(("recv: %"STAT_COUNTER_F"\n\t", igmp->recv));
+  LWIP_PLATFORM_DIAG(("drop: %"STAT_COUNTER_F"\n\t", igmp->drop));
+  LWIP_PLATFORM_DIAG(("chkerr: %"STAT_COUNTER_F"\n\t", igmp->chkerr));
+  LWIP_PLATFORM_DIAG(("lenerr: %"STAT_COUNTER_F"\n\t", igmp->lenerr));
+  LWIP_PLATFORM_DIAG(("memerr: %"STAT_COUNTER_F"\n\t", igmp->memerr));
+  LWIP_PLATFORM_DIAG(("proterr: %"STAT_COUNTER_F"\n\t", igmp->proterr));
+  LWIP_PLATFORM_DIAG(("rx_v1: %"STAT_COUNTER_F"\n\t", igmp->rx_v1));
+  LWIP_PLATFORM_DIAG(("rx_group: %"STAT_COUNTER_F"\n\t", igmp->rx_group));
+  LWIP_PLATFORM_DIAG(("rx_general: %"STAT_COUNTER_F"\n\t", igmp->rx_general));
+  LWIP_PLATFORM_DIAG(("rx_report: %"STAT_COUNTER_F"\n\t", igmp->rx_report));
+  LWIP_PLATFORM_DIAG(("tx_join: %"STAT_COUNTER_F"\n\t", igmp->tx_join));
+  LWIP_PLATFORM_DIAG(("tx_leave: %"STAT_COUNTER_F"\n\t", igmp->tx_leave));
+  LWIP_PLATFORM_DIAG(("tx_report: %"STAT_COUNTER_F"\n\t", igmp->tx_report));
+}
+#endif /* IGMP_STATS || MLD6_STATS */
+
+#if MEM_STATS || MEMP_STATS
+void
+stats_display_mem(struct stats_mem *mem, const char *name)
+{
+  LWIP_PLATFORM_DIAG(("\nMEM %s\n\t", name));
+  LWIP_PLATFORM_DIAG(("avail: %"U32_F"\n\t", (u32_t)mem->avail));
+  LWIP_PLATFORM_DIAG(("used: %"U32_F"\n\t", (u32_t)mem->used));
+  LWIP_PLATFORM_DIAG(("max: %"U32_F"\n\t", (u32_t)mem->max));
+  LWIP_PLATFORM_DIAG(("err: %"U32_F"\n", (u32_t)mem->err));
+}
+
+#if MEMP_STATS
+void
+stats_display_memp(struct stats_mem *mem, int index)
+{
+  if (index < MEMP_MAX) {
+    stats_display_mem(mem, mem->name);
+  }
+}
+#endif /* MEMP_STATS */
+#endif /* MEM_STATS || MEMP_STATS */
+
+#if SYS_STATS
+void
+stats_display_sys(struct stats_sys *sys)
+{
+  LWIP_PLATFORM_DIAG(("\nSYS\n\t"));
+  LWIP_PLATFORM_DIAG(("sem.used:  %"U32_F"\n\t", (u32_t)sys->sem.used));
+  LWIP_PLATFORM_DIAG(("sem.max:   %"U32_F"\n\t", (u32_t)sys->sem.max));
+  LWIP_PLATFORM_DIAG(("sem.err:   %"U32_F"\n\t", (u32_t)sys->sem.err));
+  LWIP_PLATFORM_DIAG(("mutex.used: %"U32_F"\n\t", (u32_t)sys->mutex.used));
+  LWIP_PLATFORM_DIAG(("mutex.max:  %"U32_F"\n\t", (u32_t)sys->mutex.max));
+  LWIP_PLATFORM_DIAG(("mutex.err:  %"U32_F"\n\t", (u32_t)sys->mutex.err));
+  LWIP_PLATFORM_DIAG(("mbox.used:  %"U32_F"\n\t", (u32_t)sys->mbox.used));
+  LWIP_PLATFORM_DIAG(("mbox.max:   %"U32_F"\n\t", (u32_t)sys->mbox.max));
+  LWIP_PLATFORM_DIAG(("mbox.err:   %"U32_F"\n\t", (u32_t)sys->mbox.err));
+}
+#endif /* SYS_STATS */
+
+void
+stats_display(void)
+{
+  s16_t i;
+
+  LINK_STATS_DISPLAY();
+  ETHARP_STATS_DISPLAY();
+  IPFRAG_STATS_DISPLAY();
+  IP6_FRAG_STATS_DISPLAY();
+  IP_STATS_DISPLAY();
+  ND6_STATS_DISPLAY();
+  IP6_STATS_DISPLAY();
+  IGMP_STATS_DISPLAY();
+  MLD6_STATS_DISPLAY();
+  ICMP_STATS_DISPLAY();
+  ICMP6_STATS_DISPLAY();
+  UDP_STATS_DISPLAY();
+  TCP_STATS_DISPLAY();
+  MEM_STATS_DISPLAY();
+  for (i = 0; i < MEMP_MAX; i++) {
+    MEMP_STATS_DISPLAY(i);
+  }
+  SYS_STATS_DISPLAY();
+}
+#endif /* LWIP_STATS_DISPLAY */
+
+#endif /* LWIP_STATS */
+

ext/lwip/src/core/sys.c

@@ -0,0 +1,68 @@
+/**
+ * @file
+ * lwIP Operating System abstraction
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "lwip/opt.h"
+
+#include "lwip/sys.h"
+
+/* Most of the functions defined in sys.h must be implemented in the
+ * architecture-dependent file sys_arch.c */
+
+#if !NO_SYS
+
+#ifndef sys_msleep
+/**
+ * Sleep for some ms. Timeouts are NOT processed while sleeping.
+ *
+ * @param ms number of milliseconds to sleep
+ */
+void
+sys_msleep(u32_t ms)
+{
+  if (ms > 0) {
+    sys_sem_t delaysem;
+    err_t err = sys_sem_new(&delaysem, 0);
+    if (err == ERR_OK) {
+      sys_arch_sem_wait(&delaysem, ms);
+      sys_sem_free(&delaysem);
+    }
+  }
+}
+#endif /* sys_msleep */
+
+#endif /* !NO_SYS */

ext/lwip/src/core/timeouts.c

@@ -0,0 +1,435 @@
+/**
+ * @file
+ * Stack-internal timers implementation.
+ * This file includes timer callbacks for stack-internal timers as well as
+ * functions to set up or stop timers and check for expired timers.
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *         Simon Goldschmidt
+ *
+ */
+
+#include "lwip/opt.h"
+
+#include "lwip/timeouts.h"
+#include "lwip/priv/tcp_priv.h"
+
+#include "lwip/def.h"
+#include "lwip/memp.h"
+#include "lwip/priv/tcpip_priv.h"
+
+#include "lwip/ip4_frag.h"
+#include "lwip/etharp.h"
+#include "lwip/dhcp.h"
+#include "lwip/autoip.h"
+#include "lwip/igmp.h"
+#include "lwip/dns.h"
+#include "lwip/nd6.h"
+#include "lwip/ip6_frag.h"
+#include "lwip/mld6.h"
+#include "lwip/sys.h"
+#include "lwip/pbuf.h"
+
+#if LWIP_DEBUG_TIMERNAMES
+#define HANDLER(x) x, #x
+#else /* LWIP_DEBUG_TIMERNAMES */
+#define HANDLER(x) x
+#endif /* LWIP_DEBUG_TIMERNAMES */
+
+/** This array contains all stack-internal cyclic timers. To get the number of
+ * timers, use LWIP_ARRAYSIZE() */
+const struct lwip_cyclic_timer lwip_cyclic_timers[] = {
+#if LWIP_TCP
+  /* The TCP timer is a special case: it does not have to run always and
+     is triggered to start from TCP using tcp_timer_needed() */
+  {TCP_TMR_INTERVAL, HANDLER(tcp_tmr)},
+#endif /* LWIP_TCP */
+#if LWIP_IPV4
+#if IP_REASSEMBLY
+  {IP_TMR_INTERVAL, HANDLER(ip_reass_tmr)},
+#endif /* IP_REASSEMBLY */
+#if LWIP_ARP
+  {ARP_TMR_INTERVAL, HANDLER(etharp_tmr)},
+#endif /* LWIP_ARP */
+#if LWIP_DHCP
+  {DHCP_COARSE_TIMER_MSECS, HANDLER(dhcp_coarse_tmr)},
+  {DHCP_FINE_TIMER_MSECS, HANDLER(dhcp_fine_tmr)},
+#endif /* LWIP_DHCP */
+#if LWIP_AUTOIP
+  {AUTOIP_TMR_INTERVAL, HANDLER(autoip_tmr)},
+#endif /* LWIP_AUTOIP */
+#if LWIP_IGMP
+  {IGMP_TMR_INTERVAL, HANDLER(igmp_tmr)},
+#endif /* LWIP_IGMP */
+#endif /* LWIP_IPV4 */
+#if LWIP_DNS
+  {DNS_TMR_INTERVAL, HANDLER(dns_tmr)},
+#endif /* LWIP_DNS */
+#if LWIP_IPV6
+  {ND6_TMR_INTERVAL, HANDLER(nd6_tmr)},
+#if LWIP_IPV6_REASS
+  {IP6_REASS_TMR_INTERVAL, HANDLER(ip6_reass_tmr)},
+#endif /* LWIP_IPV6_REASS */
+#if LWIP_IPV6_MLD
+  {MLD6_TMR_INTERVAL, HANDLER(mld6_tmr)},
+#endif /* LWIP_IPV6_MLD */
+#endif /* LWIP_IPV6 */
+};
+
+#if LWIP_TIMERS && !LWIP_TIMERS_CUSTOM
+
+/** The one and only timeout list */
+static struct sys_timeo *next_timeout;
+static u32_t timeouts_last_time;
+
+#if LWIP_TCP
+/** global variable that shows if the tcp timer is currently scheduled or not */
+static int tcpip_tcp_timer_active;
+
+/**
+ * Timer callback function that calls tcp_tmr() and reschedules itself.
+ *
+ * @param arg unused argument
+ */
+static void
+tcpip_tcp_timer(void *arg)
+{
+  LWIP_UNUSED_ARG(arg);
+
+  /* call TCP timer handler */
+  tcp_tmr();
+  /* timer still needed? */
+  if (tcp_active_pcbs || tcp_tw_pcbs) {
+    /* restart timer */
+    sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL);
+  } else {
+    /* disable timer */
+    tcpip_tcp_timer_active = 0;
+  }
+}
+
+/**
+ * Called from TCP_REG when registering a new PCB:
+ * the reason is to have the TCP timer only running when
+ * there are active (or time-wait) PCBs.
+ */
+void
+tcp_timer_needed(void)
+{
+  /* timer is off but needed again? */
+  if (!tcpip_tcp_timer_active && (tcp_active_pcbs || tcp_tw_pcbs)) {
+    /* enable and start timer */
+    tcpip_tcp_timer_active = 1;
+    sys_timeout(TCP_TMR_INTERVAL, tcpip_tcp_timer, NULL);
+  }
+}
+#endif /* LWIP_TCP */
+
+/**
+ * Timer callback function that calls mld6_tmr() and reschedules itself.
+ *
+ * @param arg unused argument
+ */
+static void
+cyclic_timer(void *arg)
+{
+  const struct lwip_cyclic_timer* cyclic = (const struct lwip_cyclic_timer*)arg;
+#if LWIP_DEBUG_TIMERNAMES
+  LWIP_DEBUGF(TIMERS_DEBUG, ("tcpip: %s()\n", cyclic->handler_name));
+#endif
+  cyclic->handler();
+  sys_timeout(cyclic->interval_ms, cyclic_timer, arg);
+}
+
+/** Initialize this module */
+void sys_timeouts_init(void)
+{
+  size_t i;
+  /* tcp_tmr() at index 0 is started on demand */
+  for (i = 1; i < LWIP_ARRAYSIZE(lwip_cyclic_timers); i++) {
+    /* we have to cast via size_t to get rid of const warning
+      (this is OK as cyclic_timer() casts back to const* */
+    sys_timeout(lwip_cyclic_timers[i].interval_ms, cyclic_timer, (void*)(size_t)&lwip_cyclic_timers[i]);
+  }
+
+  /* Initialise timestamp for sys_check_timeouts */
+  timeouts_last_time = sys_now();
+}
+
+/**
+ * Create a one-shot timer (aka timeout). Timeouts are processed in the
+ * following cases:
+ * - while waiting for a message using sys_timeouts_mbox_fetch()
+ * - by calling sys_check_timeouts() (NO_SYS==1 only)
+ *
+ * @param msecs time in milliseconds after that the timer should expire
+ * @param handler callback function to call when msecs have elapsed
+ * @param arg argument to pass to the callback function
+ */
+#if LWIP_DEBUG_TIMERNAMES
+void
+sys_timeout_debug(u32_t msecs, sys_timeout_handler handler, void *arg, const char* handler_name)
+#else /* LWIP_DEBUG_TIMERNAMES */
+void
+sys_timeout(u32_t msecs, sys_timeout_handler handler, void *arg)
+#endif /* LWIP_DEBUG_TIMERNAMES */
+{
+  struct sys_timeo *timeout, *t;
+  u32_t now, diff;
+
+  timeout = (struct sys_timeo *)memp_malloc(MEMP_SYS_TIMEOUT);
+  if (timeout == NULL) {
+    LWIP_ASSERT("sys_timeout: timeout != NULL, pool MEMP_SYS_TIMEOUT is empty", timeout != NULL);
+    return;
+  }
+
+  now = sys_now();
+  if (next_timeout == NULL) {
+    diff = 0;
+    timeouts_last_time = now;
+  } else {
+    diff = now - timeouts_last_time;
+  }
+
+  timeout->next = NULL;
+  timeout->h = handler;
+  timeout->arg = arg;
+  timeout->time = msecs + diff;
+#if LWIP_DEBUG_TIMERNAMES
+  timeout->handler_name = handler_name;
+  LWIP_DEBUGF(TIMERS_DEBUG, ("sys_timeout: %p msecs=%"U32_F" handler=%s arg=%p\n",
+    (void *)timeout, msecs, handler_name, (void *)arg));
+#endif /* LWIP_DEBUG_TIMERNAMES */
+
+  if (next_timeout == NULL) {
+    next_timeout = timeout;
+    return;
+  }
+
+  if (next_timeout->time > msecs) {
+    next_timeout->time -= msecs;
+    timeout->next = next_timeout;
+    next_timeout = timeout;
+  } else {
+    for (t = next_timeout; t != NULL; t = t->next) {
+      timeout->time -= t->time;
+      if (t->next == NULL || t->next->time > timeout->time) {
+        if (t->next != NULL) {
+          t->next->time -= timeout->time;
+        } else if (timeout->time > msecs) {
+          /* If this is the case, 'timeouts_last_time' and 'now' differs too much.
+             This can be due to sys_check_timeouts() not being called at the right
+             times, but also when stopping in a breakpoint. Anyway, let's assume
+             this is not wanted, so add the first timer's time instead of 'diff' */
+          timeout->time = msecs + next_timeout->time;
+        }
+        timeout->next = t->next;
+        t->next = timeout;
+        break;
+      }
+    }
+  }
+}
+
+/**
+ * Go through timeout list (for this task only) and remove the first matching
+ * entry (subsequent entries remain untouched), even though the timeout has not
+ * triggered yet.
+ *
+ * @param handler callback function that would be called by the timeout
+ * @param arg callback argument that would be passed to handler
+*/
+void
+sys_untimeout(sys_timeout_handler handler, void *arg)
+{
+  struct sys_timeo *prev_t, *t;
+
+  if (next_timeout == NULL) {
+    return;
+  }
+
+  for (t = next_timeout, prev_t = NULL; t != NULL; prev_t = t, t = t->next) {
+    if ((t->h == handler) && (t->arg == arg)) {
+      /* We have a match */
+      /* Unlink from previous in list */
+      if (prev_t == NULL) {
+        next_timeout = t->next;
+      } else {
+        prev_t->next = t->next;
+      }
+      /* If not the last one, add time of this one back to next */
+      if (t->next != NULL) {
+        t->next->time += t->time;
+      }
+      memp_free(MEMP_SYS_TIMEOUT, t);
+      return;
+    }
+  }
+  return;
+}
+
+/**
+ * @ingroup lwip_nosys
+ * Handle timeouts for NO_SYS==1 (i.e. without using
+ * tcpip_thread/sys_timeouts_mbox_fetch(). Uses sys_now() to call timeout
+ * handler functions when timeouts expire.
+ *
+ * Must be called periodically from your main loop.
+ */
+#if !NO_SYS && !defined __DOXYGEN__
+static
+#endif /* !NO_SYS */
+void
+sys_check_timeouts(void)
+{
+  if (next_timeout) {
+    struct sys_timeo *tmptimeout;
+    u32_t diff;
+    sys_timeout_handler handler;
+    void *arg;
+    u8_t had_one;
+    u32_t now;
+
+    now = sys_now();
+    /* this cares for wraparounds */
+    diff = now - timeouts_last_time;
+    do {
+      PBUF_CHECK_FREE_OOSEQ();
+      had_one = 0;
+      tmptimeout = next_timeout;
+      if (tmptimeout && (tmptimeout->time <= diff)) {
+        /* timeout has expired */
+        had_one = 1;
+        timeouts_last_time += tmptimeout->time;
+        diff -= tmptimeout->time;
+        next_timeout = tmptimeout->next;
+        handler = tmptimeout->h;
+        arg = tmptimeout->arg;
+#if LWIP_DEBUG_TIMERNAMES
+        if (handler != NULL) {
+          LWIP_DEBUGF(TIMERS_DEBUG, ("sct calling h=%s arg=%p\n",
+            tmptimeout->handler_name, arg));
+        }
+#endif /* LWIP_DEBUG_TIMERNAMES */
+        memp_free(MEMP_SYS_TIMEOUT, tmptimeout);
+        if (handler != NULL) {
+#if !NO_SYS
+          /* For LWIP_TCPIP_CORE_LOCKING, lock the core before calling the
+             timeout handler function. */
+          LOCK_TCPIP_CORE();
+#endif /* !NO_SYS */
+          handler(arg);
+#if !NO_SYS
+          UNLOCK_TCPIP_CORE();
+#endif /* !NO_SYS */
+        }
+        LWIP_TCPIP_THREAD_ALIVE();
+      }
+    /* repeat until all expired timers have been called */
+    } while (had_one);
+  }
+}
+
+#if NO_SYS
+/** Set back the timestamp of the last call to sys_check_timeouts()
+ * This is necessary if sys_check_timeouts() hasn't been called for a long
+ * time (e.g. while saving energy) to prevent all timer functions of that
+ * period being called.
+ */
+void
+sys_restart_timeouts(void)
+{
+  timeouts_last_time = sys_now();
+}
+#endif /* NO_SYS */
+
+/** Return the time left before the next timeout is due. If no timeouts are
+ * enqueued, returns 0xffffffff
+ */
+#if !NO_SYS
+static
+#endif /* !NO_SYS */
+u32_t
+sys_timeouts_sleeptime(void)
+{
+  u32_t diff;
+  if (next_timeout == NULL) {
+    return 0xffffffff;
+  }
+  diff = sys_now() - timeouts_last_time;
+  if (diff > next_timeout->time) {
+    return 0;
+  } else {
+    return next_timeout->time - diff;
+  }
+}
+
+#if !NO_SYS
+
+/**
+ * Wait (forever) for a message to arrive in an mbox.
+ * While waiting, timeouts are processed.
+ *
+ * @param mbox the mbox to fetch the message from
+ * @param msg the place to store the message
+ */
+void
+sys_timeouts_mbox_fetch(sys_mbox_t *mbox, void **msg)
+{
+  u32_t sleeptime;
+
+again:
+  if (!next_timeout) {
+    sys_arch_mbox_fetch(mbox, msg, 0);
+    return;
+  }
+
+  sleeptime = sys_timeouts_sleeptime();
+  if (sleeptime == 0 || sys_arch_mbox_fetch(mbox, msg, sleeptime) == SYS_ARCH_TIMEOUT) {
+    /* If a SYS_ARCH_TIMEOUT value is returned, a timeout occurred
+       before a message could be fetched. */
+    sys_check_timeouts();
+    /* We try again to fetch a message from the mbox. */
+    goto again;
+  }
+}
+
+#endif /* NO_SYS */
+
+#else /* LWIP_TIMERS && !LWIP_TIMERS_CUSTOM */
+/* Satisfy the TCP code which calls this function */
+void
+tcp_timer_needed(void)
+{
+}
+#endif /* LWIP_TIMERS && !LWIP_TIMERS_CUSTOM */