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

pull/1/head
Joseph Henry 8 years ago
parent
e5d0c07f5b
commit
f6256b71da
2 changed files with 92 additions and 45 deletions
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  1. 4
      include/libztDefs.h
  2. 133
      src/lwIP.cpp

4
include/libztDefs.h
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@ -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
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@ -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);
}
/*

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