Added untested DNS client code

examples/ztproxy/ztproxy.cpp

@@ -31,6 +31,7 @@
 #include <stdlib.h>
 #include <string>
 #include <fcntl.h>
+#include <regex.h>
 
 #include <vector>
 #include <algorithm>
@@ -45,12 +46,13 @@ namespace ZeroTier {
 	typedef void PhySocket;
 
 	ZTProxy::ZTProxy(int proxy_listen_port, std::string nwid, std::string path, std::string internal_addr, 
-		int internal_port) 
+		int internal_port, std::string dns_nameserver) 
 		:
 			_enabled(true),
 			_run(true),
 			_proxy_listen_port(proxy_listen_port),
 			_internal_port(internal_port),
+			_dns_nameserver(dns_nameserver),
 			_nwid(nwid),
 			_internal_addr(internal_addr),
 			_phy(this,false,true)
@@ -97,6 +99,14 @@ namespace ZeroTier {
 	void ZTProxy::threadMain()
 		throw()
 	{
+		// Add DNS nameserver
+		if (_dns_nameserver.length() > 0) {
+			DEBUG_INFO("setting DNS nameserver (%s)", _dns_nameserver.c_str());
+			struct sockaddr_in dns_address;
+			dns_address.sin_addr.s_addr = inet_addr(_dns_nameserver.c_str());
+			zts_add_dns_nameserver((struct sockaddr*)&dns_address);
+		}
+
 		TcpConnection *conn = NULL;
 		uint32_t msecs = 1;
 		struct timeval tv;
@@ -185,63 +195,89 @@ namespace ZeroTier {
 		}
 	}
 
+	bool isValidIPAddress(const char *ip)
+	{
+		struct sockaddr_in sa;
+		return inet_pton(AF_INET, ip, &(sa.sin_addr)) == 1;
+	}
+
 	void ZTProxy::phyOnTcpData(PhySocket *sock, void **uptr, void *data, unsigned long len)
 	{
 		int wr = 0, zfd = -1, err = 0;
 		DEBUG_EXTRA("sock=%p, len=%lu", sock, len);
 		std::string host = _internal_addr;
-		// Get the TcpConnection object 
 		TcpConnection *conn = cmap[sock];
 		if (conn == NULL) {
 			DEBUG_ERROR("invalid conn");
 			exit(0);
 		}
 		if (conn->zfd < 0) { // no connection yet
+			DEBUG_INFO("no connection yet, will establish...");
+			if (host == "") {
+				DEBUG_ERROR("invalid hostname or address (empty)");
+				return;
+			}
 			DEBUG_INFO("establishing proxy connection...");
-			if (host != "")
+		
-			{
+			uint16_t dest_port, ipv;
-				uint16_t dest_port, ipv;
+			dest_port = _internal_port;
-				dest_port = _internal_port;
+			host = _internal_addr;
-				host = _internal_addr;
 
-				ipv = host.find(":") != std::string::npos ? 6 : 4;
+			if (isValidIPAddress(host.c_str()) == false) {
+				// try to resolve this if it isn't an IP address
+				struct hostent *h = zts_gethostbyname(host.c_str());
+				if (h == NULL) {
+					DEBUG_ERROR("unable to resolve hostname (%s) (errno=%d)", host.c_str(), errno);
+					return;
+				}
+				// TODO
+				// host = h->h_addr_list[0];
+			}
 
-				if (ipv == 4) {
+			// determine address type
-					// Connect to proxied host via libzt
+			ipv = host.find(":") != std::string::npos ? 6 : 4;
-					DEBUG_INFO("attempting to proxy [0.0.0.0:%d -> %s:%d]", _proxy_listen_port, host.c_str(), dest_port);
+
-					struct sockaddr_in in4;
+			// connect to remote host
-					memset(&in4,0,sizeof(in4));
+			if (ipv == 4) {
-					in4.sin_family = AF_INET;
+				DEBUG_INFO("attempting to proxy [0.0.0.0:%d -> %s:%d]", _proxy_listen_port, host.c_str(), dest_port);
-					in4.sin_addr.s_addr = inet_addr(host.c_str());
+				struct sockaddr_in in4;
-					in4.sin_port = Utils::hton(dest_port);				
+				memset(&in4,0,sizeof(in4));
-					zfd = zts_socket(AF_INET, SOCK_STREAM, 0);
+				in4.sin_family = AF_INET;
-					err = zts_connect(zfd, (const struct sockaddr *)&in4, sizeof(in4));		
+				in4.sin_addr.s_addr = inet_addr(host.c_str());
+				in4.sin_port = Utils::hton(dest_port);				
+				if ((zfd = zts_socket(AF_INET, SOCK_STREAM, 0)) < 0) {
+					DEBUG_ERROR("unable to create socket (errno=%d)", errno);
+					return;
 				}
-				if (ipv == 6) {
+				if ((err = zts_connect(zfd, (const struct sockaddr *)&in4, sizeof(in4))) < 0) {
-					// Connect to proxied host via libzt
+					DEBUG_ERROR("unable to connect to remote host (errno=%d)", errno);
-					//DEBUG_INFO("attempting to proxy [0.0.0.0:%d -> %s:%d]", _proxy_listen_port, host.c_str(), dest_port);
-					struct sockaddr_in6 in6;
-					memset(&in6,0,sizeof(in6));
-					in6.sin6_family = AF_INET;
-					struct hostent *server;
-					server = gethostbyname2((char*)host.c_str(),AF_INET6);
-					memmove((char *) &in6.sin6_addr.s6_addr, (char *) server->h_addr, server->h_length);
-					in6.sin6_port = Utils::hton(dest_port);			
-					zfd = zts_socket(AF_INET, SOCK_STREAM, 0);
-					err = zts_connect(zfd, (const struct sockaddr *)&in6, sizeof(in6));
-				}
-				if (zfd < 0 || err < 0) {
-					// now release TX buffer contents we previously saved, since we can't connect
-					DEBUG_ERROR("error while connecting to remote host (zfd=%d, err=%d)", zfd, err);
-					conn->tx_m.lock();
-					conn->TXbuf->reset();
-					conn->tx_m.unlock();
 					return;
 				}		
-				else {
-					DEBUG_INFO("successfully connected to remote host");
-				}	
 			}
+			if (ipv == 6) {
+				//DEBUG_INFO("attempting to proxy [0.0.0.0:%d -> %s:%d]", _proxy_listen_port, host.c_str(), dest_port);
+				struct sockaddr_in6 in6;
+				memset(&in6,0,sizeof(in6));
+				in6.sin6_family = AF_INET;
+				struct hostent *server;
+				server = gethostbyname2((char*)host.c_str(),AF_INET6);
+				memmove((char *) &in6.sin6_addr.s6_addr, (char *) server->h_addr, server->h_length);
+				in6.sin6_port = Utils::hton(dest_port);			
+				zfd = zts_socket(AF_INET, SOCK_STREAM, 0);
+				err = zts_connect(zfd, (const struct sockaddr *)&in6, sizeof(in6));
+			}
+			if (zfd < 0 || err < 0) {
+				// now release TX buffer contents we previously saved, since we can't connect
+				DEBUG_ERROR("error while connecting to remote host (zfd=%d, err=%d)", zfd, err);
+				conn->tx_m.lock();
+				conn->TXbuf->reset();
+				conn->tx_m.unlock();
+				return;
+			}		
+			else {
+				DEBUG_INFO("successfully connected to remote host");
+			}	
+			
 			conn_m.lock();
 			// on success, add connection entry to map, set physock for later
 			clist.push_back(conn);
@@ -251,6 +287,9 @@ namespace ZeroTier {
 			zmap[zfd] = conn;
 			conn_m.unlock();			
 		}
+		else {
+			DEBUG_INFO("connection already established, reusing...");
+		}
 		// Write data coming from client TCP connection to its TX buffer, later emptied into libzt by threadMain I/O loop
 		conn->tx_m.lock();
 		if ((wr = conn->TXbuf->write((const unsigned char *)data, len)) < 0) {
@@ -278,6 +317,9 @@ namespace ZeroTier {
 		TcpConnection *conn = cmap[sock];
 		if (conn) {
 			conn->client_sock=NULL;
+			if (conn->zfd >= 0) {
+				zts_close(conn->zfd);
+			}
 			cmap.erase(sock);
 			for (int i=0; i<clist.size(); i++) {
 				if (conn == clist[i]) {
@@ -319,9 +361,9 @@ namespace ZeroTier {
 
 int main(int argc, char **argv)
 {
-	if (argc != 6) {
+	if (argc < 6 || argc > 7) {
 		printf("\nZeroTier TCP Proxy Service\n");
-		printf("ztproxy [config_file_path] [local_listen_port] [nwid] [zt_host_addr] [zt_resource_port]\n");
+		printf("ztproxy [config_file_path] [local_listen_port] [nwid] [zt_host_addr] [zt_resource_port] [optional_dns_nameserver]\n");
 		exit(0);
 	}
 	std::string path          = argv[1];
@@ -329,8 +371,9 @@ int main(int argc, char **argv)
 	std::string nwid          = argv[3];
 	std::string internal_addr = argv[4];
 	int internal_port         = atoi(argv[5]);
+	std::string dns_nameserver= argv[6];
 
-	ZeroTier::ZTProxy *proxy = new ZeroTier::ZTProxy(proxy_listen_port, nwid, path, internal_addr, internal_port);
+	ZeroTier::ZTProxy *proxy = new ZeroTier::ZTProxy(proxy_listen_port, nwid, path, internal_addr, internal_port, dns_nameserver);
 	
 	if (proxy) {
 		printf("\nZTProxy started. Listening on %d\n", proxy_listen_port);

examples/ztproxy/ztproxy.hpp

@@ -75,7 +75,7 @@ namespace ZeroTier {
 		friend class Phy<ZTProxy *>;
 
 	public:
-		ZTProxy(int proxy_listen_port, std::string nwid, std::string path, std::string internal_addr, int internal_port);
+		ZTProxy(int proxy_listen_port, std::string nwid, std::string path, std::string internal_addr, int internal_port, std::string _dns_nameserver);
 		~ZTProxy();
 
 		// Send incoming data to intended host
@@ -111,6 +111,7 @@ namespace ZeroTier {
 		int _internal_port;
 		std::string _nwid;
 		std::string _internal_addr;
+		std::string _dns_nameserver;
 
 		Thread _thread;
 		Phy<ZTProxy*> _phy;

include/libzt.h

@@ -413,6 +413,15 @@ int zts_gethostname(char *name, size_t len);
  */
 int zts_sethostname(const char *name, size_t len);
 
+/**
+ * @brief Return a pointer to an object with the following structure describing an internet host referenced by name
+ *
+ * @usage Call this after zts_start() has succeeded
+ * @param name
+ * @return Returns pointer to hostent structure otherwise NULL if failure
+ */
+struct hostent *zts_gethostbyname(const char *name);
+
 /**
  * @brief Close a socket
  *

include/lwIP.hpp

@@ -46,6 +46,22 @@
  */
 void lwip_driver_init();
 
+/**
+ * @brief Initialize and start the DNS client
+ *
+ * @usage Called after lwip_driver_init()
+ * @return
+ */
+void lwip_dns_init();
+
+/**
+ * @brief Starts DHCP timers
+ *
+ * @usage lwip_driver_init()
+ * @return
+ */
+void lwip_start_dhcp(struct netif *interface);
+
 void general_lwip_init_interface(void *tapref, struct netif *interface, const char *name, const ZeroTier::MAC &mac,
 	const ZeroTier::InetAddress &addr, const ZeroTier::InetAddress &nm, const ZeroTier::InetAddress &gw);
 

include/lwipopts.h

@@ -167,6 +167,7 @@
 #undef TCP_MSS
 #define TCP_MSS 1460
 
+#define LWIP_NETIF_API 1
 /*
 The TCP window size can be adjusted by changing the define TCP_WND. However,
 do keep in mind that this should be at least twice the size of TCP_MSS (thus
@@ -356,26 +357,26 @@ happening sooner than they should.
  * MEMP_NUM_NETCONN: the number of struct netconns.
  * (only needed if you use the sequential API, like api_lib.c)
  */
-#define MEMP_NUM_NETCONN                4
+#define MEMP_NUM_NETCONN                32
 
 /**
  * MEMP_NUM_TCPIP_MSG_API: the number of struct tcpip_msg, which are used
  * for callback/timeout API communication.
  * (only needed if you use tcpip.c)
  */
-#define MEMP_NUM_TCPIP_MSG_API          8
+#define MEMP_NUM_TCPIP_MSG_API          64
 
 /**
  * MEMP_NUM_TCPIP_MSG_INPKT: the number of struct tcpip_msg, which are used
  * for incoming packets.
  * (only needed if you use tcpip.c)
  */
-#define MEMP_NUM_TCPIP_MSG_INPKT        8
+#define MEMP_NUM_TCPIP_MSG_INPKT        32
 
 /**
  * PBUF_POOL_SIZE: the number of buffers in the pbuf pool.
  */
-#define PBUF_POOL_SIZE                  8000 /* was 32 */
+#define PBUF_POOL_SIZE                  4092 /* was 32 */
 
 
 /*------------------------------------------------------------------------------
@@ -433,7 +434,7 @@ happening sooner than they should.
  * PBUF_POOL_SIZE > IP_REASS_MAX_PBUFS so that the stack is still able to receive
  * packets even if the maximum amount of fragments is enqueued for reassembly!
  */
-#define IP_REASS_MAX_PBUFS              4
+#define IP_REASS_MAX_PBUFS              32
 
 /**
  * IP_FRAG_USES_STATIC_BUF==1: Use a static MTU-sized buffer for IP
@@ -476,7 +477,7 @@ happening sooner than they should.
 /**
  * LWIP_DHCP==1: Enable DHCP module.
  */
-#define LWIP_DHCP                       0
+#define LWIP_DHCP                       1
 
 
 /*------------------------------------------------------------------------------
@@ -518,7 +519,7 @@ happening sooner than they should.
  * LWIP_DNS==1: Turn on DNS module. UDP must be available for DNS
  * transport.
  */
-#define LWIP_DNS                        0
+#define LWIP_DNS                        1
 
 
 /*------------------------------------------------------------------------------

src/libzt.cpp

@@ -36,6 +36,8 @@
 #include "lwip/sockets.h"
 #include "lwip/sys.h"
 #include "lwip/ip_addr.h"
+#include "lwip/netdb.h"
+#include "dns.h"
 #endif
 #if defined(NO_STACK)
 #include <sys/socket.h>
@@ -265,6 +267,36 @@ int zts_sethostname(const char *name, size_t len)
 	return err;
 }
 
+struct hostent *zts_gethostbyname(const char *name)
+{
+#if defined(STACK_LWIP)
+	// TODO:
+	char buf[256];
+	int buflen = 256;
+	int h_err = 0;
+	struct hostent hret;
+	struct hostent **result = NULL;
+	int err = 0;
+	/*
+	if ((err = lwip_gethostbyname_r(name, &hret, buf, buflen, result, &h_err)) != 0) {
+		DEBUG_ERROR("err = %d", err);
+		DEBUG_ERROR("h_err = %d", h_err);
+		errno = h_err;
+		return NULL; // failure
+	}
+	return *result;
+	*/
+	return lwip_gethostbyname(name);
+
+
+#endif
+#if defined(STCK_PICO)
+#endif
+#if defined(NO_STACK)
+	return NULL;
+#endif
+}
+
 int zts_close(int fd)
 {
 	int err = -1;
@@ -475,6 +507,12 @@ int zts_add_dns_nameserver(struct sockaddr *addr)
 	DEBUG_EXTRA();
 	int err = -1;
 #if defined(STACK_LWIP)
+	struct sockaddr_in *in4 = (struct sockaddr_in*)&addr;
+	static ip_addr_t ipaddr;
+	ipaddr.addr = in4->sin_addr.s_addr;
+	// TODO: manage DNS server indices 
+	dns_setserver(0, &ipaddr);
+	err = 0;
 #endif
 #if defined(STCK_PICO)
 #endif

src/lwIP.cpp

@@ -51,6 +51,9 @@
 #include "lwip/timeouts.h"
 #include "lwip/stats.h"
 
+#include "dns.h"
+#include "netifapi.h"
+
 #include "lwIP.hpp"
 
 netif lwipdev, lwipdev6, n1;
@@ -87,7 +90,6 @@ static void tcpip_init_done(void *arg)
 	DEBUG_EXTRA("lwIP stack driver initialized");
 	lwip_driver_initialized = true;
 	driver_m.unlock();
-	DEBUG_EXTRA("released lock");
 	// sys_timeout(5000, tcp_timeout, NULL);
 	sys_sem_signal(sem);
 }
@@ -109,9 +111,7 @@ static void main_network_stack_thread(void *arg)
 // initialize the lwIP stack
 void lwip_driver_init()
 {
-	DEBUG_EXTRA("getting lock..");
 	driver_m.lock(); // unlocked from callback indicating completion of driver init
-	DEBUG_EXTRA("got lock");
 	if (lwip_driver_initialized == true) {
 		return;
 	}
@@ -201,6 +201,16 @@ void general_turn_on_interface(struct netif *interface)
 	//netif_set_link_down(&lwipdev);
 }
 
+void lwip_dns_init()
+{
+	dns_init();
+}
+
+void lwip_start_dhcp(struct netif *interface)
+{
+	netifapi_dhcp_start(interface);
+}
+
 void lwip_init_interface(void *tapref, const ZeroTier::MAC &mac, const ZeroTier::InetAddress &ip)
 {
 	char ipbuf[INET6_ADDRSTRLEN], nmbuf[INET6_ADDRSTRLEN];