gfwleak/zhangyang-libzt
Archived
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Added guarded RX frame buffer to lwIP driver to protect against concurrent core access

Browse Source
This commit is contained in:
Joseph Henry
2018-02-07 11:35:51 -08:00
parent e5d0c07f5b
commit f6256b71da
2 changed files with 92 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/libztDefs.h
View File

@@ -50,6 +50,8 @@
#define STACK_PICO 0
#define NO_STACK 0 // for layer-2 only (this will omit all userspace network stack code)
#define LWIP_GUARDED_BUF_CHECK_INTERVAL 50 // in ms
#define LWIP_MAX_GUARDED_RX_BUF_SZ 1024 // number of frame pointers that can be cached waiting for receipt into core
/* sanity checks for userspace network stack and socket API layer choices
@@ -219,6 +221,8 @@ struct sockaddr_ll {
/* lwIP */
/****************************************************************************/
#define LWIP_NETIF_STATUS_CALLBACK 0
// For LWIP configuration see: include/lwipopts.h
#if defined(STACK_LWIP)

133
src/lwIP.cpp
View File

@@ -77,6 +77,10 @@ bool virt_can_provision_new_socket(int socket_type);
struct netif lwipInterfaces[10];
int lwipInterfacesCount = 0;
ZeroTier::Mutex _rx_input_lock_m;
struct pbuf* lwip_frame_rxbuf[1024];
int lwip_frame_rxbuf_tot = 0;
bool lwip_driver_initialized = false;
ZeroTier::Mutex driver_m;
@@ -112,6 +116,75 @@ static void tcpip_init_done(void *arg)
sys_sem_signal(sem);
}
void my_tcpip_callback(void *arg)
{
Mutex::Lock _l(_rx_input_lock_m);
int loop_score = 16; // max num of packets to read per polling call
// TODO: Optimize (use Ringbuffer)
int pkt_num = 0;
int count_initial = lwip_frame_rxbuf_tot;
int count_final = 0;
while (lwip_frame_rxbuf_tot > 0 && loop_score > 0) {
struct pbuf *p = lwip_frame_rxbuf[pkt_num];
pkt_num += 1;
// DEBUG_INFO("copying received packet FROM guarded buffer (addr=%p) total frames in buffer = %d", p, lwip_frame_rxbuf_tot);
// Packet routing logic. Inputs packet into correct lwip netif interface depending on protocol type
struct ip_hdr *iphdr;
//ip_addr_t iphdr_dest;
switch (((struct eth_hdr *)p->payload)->type)
{
case PP_HTONS(ETHTYPE_IPV6): {
iphdr = (struct ip_hdr *)((char *)p->payload + SIZEOF_ETH_HDR);
for (int i=0; i<lwipInterfacesCount; i++) {
if (lwipInterfaces[i].output_ip6 && lwipInterfaces[i].output_ip6 == ethip6_output) {
if (lwipInterfaces[i].input(p, &lwipInterfaces[i]) != ERR_OK) {
DEBUG_ERROR("packet input error (ipv6, p=%p, netif=%p)", p, &lwipInterfaces[i]);
break;
}
}
}
} break;
case PP_HTONS(ETHTYPE_IP): {
iphdr = (struct ip_hdr *)((char *)p->payload + SIZEOF_ETH_HDR);
for (int i=0; i<lwipInterfacesCount; i++) {
if (lwipInterfaces[i].output && lwipInterfaces[i].output == etharp_output) {
if (lwipInterfaces[i].ip_addr.u_addr.ip4.addr == iphdr->dest.addr || ip4_addr_isbroadcast_u32(iphdr->dest.addr, &lwipInterfaces[i])) {
if (lwipInterfaces[i].input(p, &lwipInterfaces[i]) != ERR_OK) {
DEBUG_ERROR("packet input error (ipv4, p=%p, netif=%p)", p, &lwipInterfaces[i]);
break;
}
}
}
}
} break;
case PP_HTONS(ETHTYPE_ARP): {
for (int i=0; i<lwipInterfacesCount; i++) {
if (lwipInterfaces[i].state) {
pbuf_ref(p);
if (lwipInterfaces[i].input(p, &lwipInterfaces[i]) != ERR_OK) {
DEBUG_ERROR("packet input error (arp, p=%p, netif=%p)", p, &lwipInterfaces[i]);
}
break;
}
}
break;
} break;
default:
break;
}
lwip_frame_rxbuf_tot-=1;
loop_score--;
}
count_final = count_initial - lwip_frame_rxbuf_tot;
//DEBUG_INFO("adjusting buffer by (%d) elements, total frames in buffer = %d", count_final, lwip_frame_rxbuf_tot);
// move pbuf address buffer by the number of packets successfully fed into the stack core
memmove(lwip_frame_rxbuf, lwip_frame_rxbuf + count_final, sizeof(lwip_frame_rxbuf) - count_final);
}
// main thread which starts the initialization process
static void main_thread(void *arg)
{
@@ -120,9 +193,18 @@ static void main_thread(void *arg)
if (sys_sem_new(&sem, 0) != ERR_OK) {
DEBUG_ERROR("failed to create semaphore");
}
tcpip_init(tcpip_init_done, &sem);
sys_sem_wait(&sem);
DEBUG_EXTRA("stack thread init complete");
while(1)
{
usleep(LWIP_GUARDED_BUF_CHECK_INTERVAL*1000);
// Handle incoming packets from the core's thread context.
// If you feed frames into the core directly you will violate the core's thread model
tcpip_callback_with_block(my_tcpip_callback, NULL, 1);
}
sys_sem_wait(&sem); // block forever
}
@@ -232,52 +314,13 @@ void lwip_eth_rx(VirtualTap *tap, const ZeroTier::MAC &from, const ZeroTier::MAC
DEBUG_ERROR("there are no netifs set up to handle this packet. ignoring.");
return;
}
// Routing
struct ip_hdr *iphdr;
//ip_addr_t iphdr_dest;
switch (((struct eth_hdr *)p->payload)->type)
{
case PP_HTONS(ETHTYPE_IPV6): {
iphdr = (struct ip_hdr *)((char *)p->payload + SIZEOF_ETH_HDR);
for (int i=0; i<lwipInterfacesCount; i++) {
if (lwipInterfaces[i].output_ip6 && lwipInterfaces[i].output_ip6 == ethip6_output) {
if (lwipInterfaces[i].input(p, &lwipInterfaces[i]) != ERR_OK) {
DEBUG_ERROR("packet input error (ipv6, p=%p, netif=%p)", p, &lwipInterfaces[i]);
break;
}
}
}
} break;
case PP_HTONS(ETHTYPE_IP): {
iphdr = (struct ip_hdr *)((char *)p->payload + SIZEOF_ETH_HDR);
for (int i=0; i<lwipInterfacesCount; i++) {
if (lwipInterfaces[i].output && lwipInterfaces[i].output == etharp_output) {
if (lwipInterfaces[i].ip_addr.u_addr.ip4.addr == iphdr->dest.addr || ip4_addr_isbroadcast_u32(iphdr->dest.addr, &lwipInterfaces[i])) {
if (lwipInterfaces[i].input(p, &lwipInterfaces[i]) != ERR_OK) {
DEBUG_ERROR("packet input error (ipv4, p=%p, netif=%p)", p, &lwipInterfaces[i]);
break;
}
}
}
}
} break;
case PP_HTONS(ETHTYPE_ARP): {
for (int i=0; i<lwipInterfacesCount; i++) {
if (lwipInterfaces[i].state) {
pbuf_ref(p);
if (lwipInterfaces[i].input(p, &lwipInterfaces[i]) != ERR_OK) {
DEBUG_ERROR("packet input error (arp, p=%p, netif=%p)", p, &lwipInterfaces[i]);
}
break;
}
}
break;
} break;
default:
break;
Mutex::Lock _l(_rx_input_lock_m);
if (lwip_frame_rxbuf_tot == LWIP_MAX_GUARDED_RX_BUF_SZ) {
//DEBUG_ERROR("guarded receive buffer full, adjust MAX_GUARDED_RX_BUF_SZ or ");
}
lwip_frame_rxbuf[lwip_frame_rxbuf_tot] = p;
lwip_frame_rxbuf_tot += 1;
//DEBUG_INFO("copying received packet TO guarded buffer (addr=%p) total frames in buffer = %d", p, lwip_frame_rxbuf_tot);
}
/*