/**
* 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 ICACHE_FLASH_ATTR
raw_input(struct pbuf *p, struct netif *inp)
{
struct raw_pcb *pcb, *prev;
struct ip_hdr *iphdr;
s16_t proto;
u8_t eaten = 0;
#if LWIP_IPV6
struct ip6_hdr *ip6hdr;
#endif /* LWIP_IPV6 */
LWIP_UNUSED_ARG(inp);
iphdr = (struct ip_hdr *)p->payload;
#if LWIP_IPV6
if (IPH_V(iphdr) == 6) {
ip6hdr = (struct ip6_hdr *)p->payload;
proto = IP6H_NEXTH(ip6hdr);
}
else
#endif /* LWIP_IPV6 */
{
proto = IPH_PROTO(iphdr);
}
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) && IP_PCB_IPVER_INPUT_MATCH(pcb) &&
(ipX_addr_isany(PCB_ISIPV6(pcb), &pcb->local_ip) ||
ipX_addr_cmp(PCB_ISIPV6(pcb), &(pcb->local_ip), ipX_current_dest_addr()))) {
#if IP_SOF_BROADCAST_RECV
/* broadcast filter? */
if ((ip_get_option(pcb, SOF_BROADCAST) || !ip_addr_isbroadcast(ip_current_dest_addr(), inp))
#if LWIP_IPV6
&& !PCB_ISIPV6(pcb)
#endif /* LWIP_IPV6 */
)
#endif /* IP_SOF_BROADCAST_RECV */
{
/* receive callback function available? */
if (pcb->recv.ip4 != NULL) {
#ifndef LWIP_NOASSERT
void* old_payload = p->payload;
#endif
/* the receive callback function did not eat the packet? */
eaten = pcb->recv.ip4(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;
}
/**
* Lwip thread callback invoked via fwudp::msg_send
*/
void
fwudp_pcb_send(void *arg)
{
struct fwudp *fwudp = (struct fwudp *)arg;
struct fwudp_dgram dgram;
struct udp_pcb *pcb;
struct udp_pcb **pprev;
int isv6;
size_t idx;
idx = fwudp->inbuf.unsent;
if (idx == fwudp->inbuf.vacant) {
/* empty buffer - shouldn't happen! */
DPRINTF(("%s: ring buffer empty!\n", __func__));
return;
}
dgram = fwudp->inbuf.buf[idx]; /* struct copy */
#if 1 /* valgrind hint */
fwudp->inbuf.buf[idx].p = NULL;
#endif
if (++idx == fwudp->inbuf.bufsize) {
idx = 0;
}
fwudp->inbuf.unsent = idx;
/* XXX: this is *STUPID* */
isv6 = (fwudp->fwspec.sdom == PF_INET6);
pprev = &udp_proxy_pcbs;
for (pcb = udp_proxy_pcbs; pcb != NULL; pcb = pcb->next) {
if (PCB_ISIPV6(pcb) == isv6
&& pcb->remote_port == fwudp->dst_port
&& ipX_addr_cmp(isv6, &fwudp->dst_addr, &pcb->remote_ip)
&& pcb->local_port == dgram.src_port
&& ipX_addr_cmp(isv6, &dgram.src_addr, &pcb->local_ip))
{
break;
}
else {
pprev = &pcb->next;
}
}
if (pcb != NULL) {
*pprev = pcb->next;
pcb->next = udp_proxy_pcbs;
udp_proxy_pcbs = pcb;
/*
* XXX: check that its ours and not accidentally created by
* outbound traffic.
*
* ???: Otherwise? Expire it and set pcb = NULL; to create a
* new one below?
*/
}
if (pcb == NULL) {
pcb = udp_new();
if (pcb == NULL) {
goto out;
}
ip_set_v6(pcb, isv6);
/* equivalent of udp_bind */
ipX_addr_set(isv6, &pcb->local_ip, &dgram.src_addr);
pcb->local_port = dgram.src_port;
/* equivalent to udp_connect */
ipX_addr_set(isv6, &pcb->remote_ip, &fwudp->dst_addr);
pcb->remote_port = fwudp->dst_port;
pcb->flags |= UDP_FLAGS_CONNECTED;
udp_recv(pcb, fwudp_pcb_recv, fwudp);
pcb->next = udp_proxy_pcbs;
udp_proxy_pcbs = pcb;
udp_proxy_timer_needed();
}
udp_send(pcb, dgram.p);
out:
pbuf_free(dgram.p);
}
