/**
* Forwards an IP packet. It finds an appropriate route for the
* packet, decrements the TTL value of the packet, adjusts the
* checksum and outputs the packet on the appropriate interface.
*
* @param p the packet to forward (p->payload points to IP header)
* @param iphdr the IP header of the input packet
* @param inp the netif on which this packet was received
* @return the netif on which the packet was sent (NULL if it wasn't sent)
*/
static struct netif *
ip_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
{
struct netif *netif;
PERF_START;
/* Find network interface where to forward this IP packet to. */
netif = ip_route((struct ip_addr *)&(iphdr->dest));
if (netif == NULL) {
LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for 0x%"X32_F" found\n",
iphdr->dest.addr));
snmp_inc_ipoutnoroutes();
return (struct netif *)NULL;
}
/* Do not forward packets onto the same network interface on which
* they arrived. */
if (netif == inp) {
LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n"));
snmp_inc_ipoutnoroutes();
return (struct netif *)NULL;
}
/* decrement TTL */
IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
/* send ICMP if TTL == 0 */
if (IPH_TTL(iphdr) == 0) {
snmp_inc_ipinhdrerrors();
#if LWIP_ICMP
/* Don't send ICMP messages in response to ICMP messages */
if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
icmp_time_exceeded(p, ICMP_TE_TTL);
}
#endif /* LWIP_ICMP */
return (struct netif *)NULL;
}
/* Incrementally update the IP checksum. */
if (IPH_CHKSUM(iphdr) >= htons(0xffff - 0x100)) {
IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100) + 1);
} else {
IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100));
}
LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to 0x%"X32_F"\n",
iphdr->dest.addr));
IP_STATS_INC(ip.fw);
IP_STATS_INC(ip.xmit);
snmp_inc_ipforwdatagrams();
PERF_STOP("ip_forward");
/* transmit pbuf on chosen interface */
netif->output(netif, p, (struct ip_addr *)&(iphdr->dest));
return netif;
}
void minheap_build(int *v, int len)
{
int i;
PERF_START();
PERF_PROBLEM_SIZE(len);
for (i = len; i > 0; i--) {
minheap_heapify(v, i, len);
}
PERF_STOP();
}
err_t
ip_output_if (struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
u8_t ttl,
u8_t proto, struct netif *netif)
{
struct ip_hdr *iphdr;
PERF_START;
xprintf("len %"U16_F" tot_len %"U16_F"\n", p->len, p->tot_len);
if (pbuf_header(p, IP_HLEN)) {
LWIP_DEBUGF(IP_DEBUG, ("ip_output: not enough room for IP header in pbuf\n"));
#ifdef IP_STATS
++lwip_stats.ip.err;
#endif /* IP_STATS */
return ERR_BUF;
}
xprintf("len %"U16_F" tot_len %"U16_F"\n", p->len, p->tot_len);
iphdr = p->payload;
if (dest != IP_HDRINCL) {
xprintf("!IP_HDRLINCL\n");
iphdr->hoplim = ttl;
iphdr->nexthdr = proto;
iphdr->len = htons(p->tot_len - IP_HLEN);
ip_addr_set(&(iphdr->dest), dest);
iphdr->v = 6;
if (ip_addr_isany(src)) {
ip_addr_set(&(iphdr->src), &(netif->ip_addr));
} else {
ip_addr_set(&(iphdr->src), src);
}
} else {
dest = &(iphdr->dest);
}
#ifdef IP_STATS
++lwip_stats.ip.xmit;
#endif /* IP_STATS */
LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c (len %"U16_F")\n", netif->name[0], netif->name[1], p->tot_len));
#if IP_DEBUG
ip_debug_print(p);
#endif /* IP_DEBUG */
PERF_STOP("ip_output_if");
return netif->output(netif, p, dest);
}
/*-----------------------------------------------------------------------------------*/
static void
ip_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
{
static struct netif *netif;
PERF_START;
if((netif = ip_route((struct ip_addr *)&(iphdr->dest))) == NULL) {
DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for 0x%lx found\n",
iphdr->dest.addr));
return;
}
/* Don't forward packets onto the same network interface on which
they arrived. */
if(netif == inp) {
DEBUGF(IP_DEBUG, ("ip_forward: not forward packets back on incoming interface.\n"));
return;
}
/* Decrement TTL and send ICMP if ttl == 0. */
IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
if(IPH_TTL(iphdr) == 0) {
/* Don't send ICMP messages in response to ICMP messages */
if(IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
icmp_time_exceeded(p, ICMP_TE_TTL);
}
return;
}
/* Incremental update of the IP checksum. */
if(IPH_CHKSUM(iphdr) >= htons(0xffff - 0x100)) {
IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100) + 1);
} else {
IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100));
}
DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to 0x%lx\n",
iphdr->dest.addr));
#ifdef IP_STATS
++stats.ip.fw;
++stats.ip.xmit;
#endif /* IP_STATS */
PERF_STOP("ip_forward");
netif->output(netif, p, (struct ip_addr *)&(iphdr->dest));
}
int minheap_extract(int *v, int *len)
{
int ret = v[1];
PERF_START();
PERF_PROBLEM_SIZE(*len);
v[1] = v[*len];
(*len)--;
minheap_heapify(v, 1, *len);
PERF_STOP();
return ret;
}
static void
ip_forward(struct pbuf *p, struct ip_hdr *iphdr)
{
struct netif *netif;
PERF_START;
if ((netif = ip_route((struct ip_addr *)&(iphdr->dest))) == NULL) {
LWIP_DEBUGF(IP_DEBUG, ("ip_input: no forwarding route found for "));
#if IP_DEBUG
ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
#endif /* IP_DEBUG */
LWIP_DEBUGF(IP_DEBUG, ("\n"));
pbuf_free(p);
return;
}
/* Decrement TTL and send ICMP if ttl == 0. */
if (--iphdr->hoplim == 0) {
#if LWIP_ICMP
/* Don't send ICMP messages in response to ICMP messages */
if (iphdr->nexthdr != IP_PROTO_ICMP) {
icmp_time_exceeded(p, ICMP_TE_TTL);
}
#endif /* LWIP_ICMP */
pbuf_free(p);
return;
}
/* Incremental update of the IP checksum. */
/* if (iphdr->chksum >= htons(0xffff - 0x100)) {
iphdr->chksum += htons(0x100) + 1;
} else {
iphdr->chksum += htons(0x100);
}*/
LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to "));
#if IP_DEBUG
ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
#endif /* IP_DEBUG */
LWIP_DEBUGF(IP_DEBUG, ("\n"));
IP_STATS_INC(ip.fw);
IP_STATS_INC(ip.xmit);
PERF_STOP("ip_forward");
netif->output(netif, p, (struct ip_addr *)&(iphdr->dest));
}
/**
* Dereference a pbuf chain or queue and deallocate any no-longer-used
* pbufs at the head of this chain or queue.
*
* Decrements the pbuf reference count. If it reaches zero, the pbuf is
* deallocated.
*
* For a pbuf chain, this is repeated for each pbuf in the chain,
* up to the first pbuf which has a non-zero reference count after
* decrementing. So, when all reference counts are one, the whole
* chain is free'd.
*
* @param pbuf The pbuf (chain) to be dereferenced.
*
* @return the number of pbufs that were de-allocated
* from the head of the chain.
*
* @note MUST NOT be called on a packet queue (Not verified to work yet).
* @note the reference counter of a pbuf equals the number of pointers
* that refer to the pbuf (or into the pbuf).
*
* @internal examples:
*
* Assuming existing chains a->b->c with the following reference
* counts, calling pbuf_free(a) results in:
*
* 1->2->3 becomes ...1->3
* 3->3->3 becomes 2->3->3
* 1->1->2 becomes ......1
* 2->1->1 becomes 1->1->1
* 1->1->1 becomes .......
*
*/
u8_t
pbuf_free(struct pbuf *p)
{
struct pbuf *q;
u8_t count;
SYS_ARCH_DECL_PROTECT(old_level);
LWIP_ASSERT("p != NULL", p != NULL);
/* if assertions are disabled, proceed with debug output */
if (p == NULL) {
LWIP_DEBUGF(PBUF_DEBUG | DBG_TRACE | 2, ("pbuf_free(p == NULL) was called.\n"));
return 0;
}
LWIP_DEBUGF(PBUF_DEBUG | DBG_TRACE | 3, ("pbuf_free(%p)\n", (void *)p));
PERF_START;
LWIP_ASSERT("pbuf_free: sane flags",
p->flags == PBUF_FLAG_RAM || p->flags == PBUF_FLAG_ROM ||
p->flags == PBUF_FLAG_REF || p->flags == PBUF_FLAG_POOL);
count = 0;
/* Since decrementing ref cannot be guaranteed to be a single machine operation
* we must protect it. Also, the later test of ref must be protected.
*/
SYS_ARCH_PROTECT(old_level);
/* de-allocate all consecutive pbufs from the head of the chain that
* obtain a zero reference count after decrementing*/
while (p != NULL) {
/* all pbufs in a chain are referenced at least once */
LWIP_ASSERT("pbuf_free: p->ref > 0", p->ref > 0);
/* decrease reference count (number of pointers to pbuf) */
p->ref--;
/* this pbuf is no longer referenced to? */
if (p->ref == 0) {
/* remember next pbuf in chain for next iteration */
q = p->next;
LWIP_DEBUGF( PBUF_DEBUG | 2, ("pbuf_free: deallocating %p\n", (void *)p));
/* is this a pbuf from the pool? */
if (p->flags == PBUF_FLAG_POOL) {
p->len = p->tot_len = PBUF_POOL_BUFSIZE;
p->payload = (void *)((u8_t *)p + sizeof(struct pbuf));
PBUF_POOL_FREE(p);
/* is this a ROM or RAM referencing pbuf? */
} else if (p->flags == PBUF_FLAG_ROM || p->flags == PBUF_FLAG_REF) {
memp_free(MEMP_PBUF, p);
/* p->flags == PBUF_FLAG_RAM */
} else {
mem_free(p);
}
count++;
/* proceed to next pbuf */
p = q;
/* p->ref > 0, this pbuf is still referenced to */
/* (and so the remaining pbufs in chain as well) */
} else {
LWIP_DEBUGF( PBUF_DEBUG | 2, ("pbuf_free: %p has ref %u, ending here.\n", (void *)p, (unsigned int)p->ref));
/* stop walking through the chain */
p = NULL;
}
}
SYS_ARCH_UNPROTECT(old_level);
PERF_STOP("pbuf_free");
/* return number of de-allocated pbufs */
return count;
}
/**
* Process an incoming UDP datagram.
*
* Given an incoming UDP datagram (as a chain of pbufs) this function
* finds a corresponding UDP PCB and hands over the pbuf to the pcbs
* recv function. If no pcb is found or the datagram is incorrect, the
* pbuf is freed.
*
* @param p pbuf to be demultiplexed to a UDP PCB.
* @param inp network interface on which the datagram was received.
*
*/
void
udp_input(struct pbuf *p, struct netif *inp)
{
struct udp_hdr *udphdr;
struct udp_pcb *pcb, *prev;
struct udp_pcb *uncon_pcb;
struct ip_hdr *iphdr;
u16_t src, dest;
u8_t local_match;
u8_t broadcast;
PERF_START;
UDP_STATS_INC(udp.recv);
iphdr = p->payload;
/* Check minimum length (IP header + UDP header)
* and move payload pointer to UDP header */
if (p->tot_len < (IPH_HL(iphdr) * 4 + UDP_HLEN) || pbuf_header(p, -(s16_t)(IPH_HL(iphdr) * 4))) {
/* drop short packets */
LWIP_DEBUGF(UDP_DEBUG,
("udp_input: short UDP datagram (%"U16_F" bytes) discarded\n", p->tot_len));
UDP_STATS_INC(udp.lenerr);
UDP_STATS_INC(udp.drop);
snmp_inc_udpinerrors();
pbuf_free(p);
goto end;
}
udphdr = (struct udp_hdr *)p->payload;
/* is broadcast packet ? */
broadcast = ip_addr_isbroadcast(&(iphdr->dest), inp);
LWIP_DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %"U16_F"\n", p->tot_len));
/* convert src and dest ports to host byte order */
src = ntohs(udphdr->src);
dest = ntohs(udphdr->dest);
udp_debug_print(udphdr);
/* print the UDP source and destination */
LWIP_DEBUGF(UDP_DEBUG,
("udp (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") <-- "
"(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
ip4_addr1(&iphdr->dest), ip4_addr2(&iphdr->dest),
ip4_addr3(&iphdr->dest), ip4_addr4(&iphdr->dest), ntohs(udphdr->dest),
ip4_addr1(&iphdr->src), ip4_addr2(&iphdr->src),
ip4_addr3(&iphdr->src), ip4_addr4(&iphdr->src), ntohs(udphdr->src)));
#if LWIP_DHCP
pcb = NULL;
/* when LWIP_DHCP is active, packets to DHCP_CLIENT_PORT may only be processed by
the dhcp module, no other UDP pcb may use the local UDP port DHCP_CLIENT_PORT */
if (dest == DHCP_CLIENT_PORT) {
/* all packets for DHCP_CLIENT_PORT not coming from DHCP_SERVER_PORT are dropped! */
if (src == DHCP_SERVER_PORT) {
if ((inp->dhcp != NULL) && (inp->dhcp->pcb != NULL)) {
/* accept the packe if
(- broadcast or directed to us) -> DHCP is link-layer-addressed, local ip is always ANY!
- inp->dhcp->pcb->remote == ANY or iphdr->src */
if ((ip_addr_isany(&inp->dhcp->pcb->remote_ip) ||
ip_addr_cmp(&(inp->dhcp->pcb->remote_ip), &(iphdr->src)))) {
pcb = inp->dhcp->pcb;
}
}
}
} else
#endif /* LWIP_DHCP */
{
prev = NULL;
local_match = 0;
uncon_pcb = NULL;
/* Iterate through the UDP pcb list for a matching pcb.
* 'Perfect match' pcbs (connected to the remote port & ip address) are
* preferred. If no perfect match is found, the first unconnected pcb that
* matches the local port and ip address gets the datagram. */
for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
local_match = 0;
/* print the PCB local and remote address */
LWIP_DEBUGF(UDP_DEBUG,
("pcb (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") --- "
"(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
ip4_addr1(&pcb->local_ip), ip4_addr2(&pcb->local_ip),
ip4_addr3(&pcb->local_ip), ip4_addr4(&pcb->local_ip), pcb->local_port,
ip4_addr1(&pcb->remote_ip), ip4_addr2(&pcb->remote_ip),
ip4_addr3(&pcb->remote_ip), ip4_addr4(&pcb->remote_ip), pcb->remote_port));
/* compare PCB local addr+port to UDP destination addr+port */
if ((pcb->local_port == dest) &&
((!broadcast && ip_addr_isany(&pcb->local_ip)) ||
ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)) ||
#if LWIP_IGMP
ip_addr_ismulticast(&(iphdr->dest)) ||
#endif /* LWIP_IGMP */
#if IP_SOF_BROADCAST_RECV
(broadcast && (pcb->so_options & SOF_BROADCAST)))) {
#else /* IP_SOF_BROADCAST_RECV */
(broadcast))) {
#endif /* IP_SOF_BROADCAST_RECV */
local_match = 1;
if ((uncon_pcb == NULL) &&
((pcb->flags & UDP_FLAGS_CONNECTED) == 0)) {
/* the first unconnected matching PCB */
uncon_pcb = pcb;
}
}
/* compare PCB remote addr+port to UDP source addr+port */
if ((local_match != 0) &&
(pcb->remote_port == src) &&
(ip_addr_isany(&pcb->remote_ip) ||
ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)))) {
/* the first fully matching PCB */
if (prev != NULL) {
/* move the pcb to the front of udp_pcbs so that is
found faster next time */
prev->next = pcb->next;
pcb->next = udp_pcbs;
udp_pcbs = pcb;
} else {
UDP_STATS_INC(udp.cachehit);
}
break;
}
#if LWIP_UPNP
if((local_match != 0) && (dest == 1900)) {
break;
}
#endif
prev = pcb;
}
/* no fully matching pcb found? then look for an unconnected pcb */
if (pcb == NULL) {
pcb = uncon_pcb;
}
}
/* Check checksum if this is a match or if it was directed at us. */
if (pcb != NULL || ip_addr_cmp(&inp->ip_addr, &iphdr->dest)) {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
#if LWIP_UDPLITE
if (IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) {
/* Do the UDP Lite checksum */
#if CHECKSUM_CHECK_UDP
u16_t chklen = ntohs(udphdr->len);
if (chklen < sizeof(struct udp_hdr)) {
if (chklen == 0) {
/* For UDP-Lite, checksum length of 0 means checksum
over the complete packet (See RFC 3828 chap. 3.1) */
chklen = p->tot_len;
} else {
/* At least the UDP-Lite header must be covered by the
checksum! (Again, see RFC 3828 chap. 3.1) */
UDP_STATS_INC(udp.chkerr);
UDP_STATS_INC(udp.drop);
snmp_inc_udpinerrors();
pbuf_free(p);
goto end;
}
}
if (inet_chksum_pseudo_partial(p, (struct ip_addr *)&(iphdr->src),
(struct ip_addr *)&(iphdr->dest),
IP_PROTO_UDPLITE, p->tot_len, chklen) != 0) {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("udp_input: UDP Lite datagram discarded due to failing checksum\n"));
UDP_STATS_INC(udp.chkerr);
UDP_STATS_INC(udp.drop);
snmp_inc_udpinerrors();
pbuf_free(p);
goto end;
}
#endif /* CHECKSUM_CHECK_UDP */
} else
#endif /* LWIP_UDPLITE */
{
#if CHECKSUM_CHECK_UDP
if (udphdr->chksum != 0) {
if (inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src),
(struct ip_addr *)&(iphdr->dest),
IP_PROTO_UDP, p->tot_len) != 0) {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("udp_input: UDP datagram discarded due to failing checksum\n"));
UDP_STATS_INC(udp.chkerr);
UDP_STATS_INC(udp.drop);
snmp_inc_udpinerrors();
pbuf_free(p);
goto end;
}
}
#endif /* CHECKSUM_CHECK_UDP */
}
if(pbuf_header(p, -UDP_HLEN)) {
/* Can we cope with this failing? Just assert for now */
LWIP_ASSERT("pbuf_header failed\n", 0);
UDP_STATS_INC(udp.drop);
snmp_inc_udpinerrors();
pbuf_free(p);
goto end;
}
if (pcb != NULL) {
snmp_inc_udpindatagrams();
/* callback */
if (pcb->recv != NULL) {
/* now the recv function is responsible for freeing p */
pcb->recv(pcb->recv_arg, pcb, p, &iphdr->src, src);
} else {
/* no recv function registered? then we have to free the pbuf! */
pbuf_free(p);
goto end;
}
} else {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: not for us.\n"));
#if LWIP_ICMP
/* No match was found, send ICMP destination port unreachable unless
destination address was broadcast/multicast. */
if (!broadcast &&
!ip_addr_ismulticast(&iphdr->dest)) {
/* move payload pointer back to ip header */
pbuf_header(p, (IPH_HL(iphdr) * 4) + UDP_HLEN);
LWIP_ASSERT("p->payload == iphdr", (p->payload == iphdr));
icmp_dest_unreach(p, ICMP_DUR_PORT);
}
#endif /* LWIP_ICMP */
UDP_STATS_INC(udp.proterr);
UDP_STATS_INC(udp.drop);
snmp_inc_udpnoports();
pbuf_free(p);
}
} else {
pbuf_free(p);
}
end:
PERF_STOP("udp_input");
}
void
ip_input(struct pbuf *p, struct netif *inp) {
struct ip_hdr *iphdr;
struct netif *netif;
PERF_START;
#if IP_DEBUG
ip_debug_print(p);
#endif /* IP_DEBUG */
IP_STATS_INC(ip.recv);
/* identify the IP header */
iphdr = p->payload;
if (iphdr->v != 6) {
LWIP_DEBUGF(IP_DEBUG, ("IP packet dropped due to bad version number\n"));
#if IP_DEBUG
ip_debug_print(p);
#endif /* IP_DEBUG */
pbuf_free(p);
IP_STATS_INC(ip.err);
IP_STATS_INC(ip.drop);
return;
}
/* is this packet for us? */
for(netif = netif_list; netif != NULL; netif = netif->next) {
#if IP_DEBUG
LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest "));
ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
LWIP_DEBUGF(IP_DEBUG, ("netif->ip_addr "));
ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
LWIP_DEBUGF(IP_DEBUG, ("\n"));
#endif /* IP_DEBUG */
if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr))) {
break;
}
}
if (netif == NULL) {
/* packet not for us, route or discard */
#if IP_FORWARD
ip_forward(p, iphdr);
#endif
pbuf_free(p);
return;
}
pbuf_realloc(p, IP_HLEN + ntohs(iphdr->len));
/* send to upper layers */
#if IP_DEBUG
/* LWIP_DEBUGF("ip_input: \n");
ip_debug_print(p);
LWIP_DEBUGF("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len);*/
#endif /* IP_DEBUG */
if(pbuf_header(p, -IP_HLEN)) {
LWIP_ASSERT("Can't move over header in packet", 0);
return;
}
switch (iphdr->nexthdr) {
case IP_PROTO_UDP:
udp_input(p, inp);
break;
case IP_PROTO_TCP:
tcp_input(p, inp);
break;
#if LWIP_ICMP
case IP_PROTO_ICMP:
icmp_input(p, inp);
break;
#endif /* LWIP_ICMP */
default:
#if LWIP_ICMP
/* send ICMP destination protocol unreachable */
icmp_dest_unreach(p, ICMP_DUR_PROTO);
#endif /* LWIP_ICMP */
pbuf_free(p);
LWIP_DEBUGF(IP_DEBUG, ("Unsupported transport protocol %"U16_F"\n",
iphdr->nexthdr));
IP_STATS_INC(ip.proterr);
IP_STATS_INC(ip.drop);
}
PERF_STOP("ip_input");
}
/**
* The initial input processing of TCP. It verifies the TCP header, demultiplexes
* the segment between the PCBs and passes it on to tcp_process(), which implements
* the TCP finite state machine. This function is called by the IP layer (in
* ip_input()).
*
* @param p received TCP segment to process (p->payload pointing to the IP header)
* @param inp network interface on which this segment was received
*/
void
tcp_input(struct pbuf *p, struct netif *inp)
{
struct tcp_pcb *pcb, *prev;
struct tcp_pcb_listen *lpcb;
u8_t hdrlen;
err_t err;
PERF_START;
TCP_STATS_INC(tcp.recv);
snmp_inc_tcpinsegs();
iphdr = p->payload;
tcphdr = (struct tcp_hdr *)((u8_t *)p->payload + IPH_HL(iphdr) * 4);
#if TCP_INPUT_DEBUG
tcp_debug_print(tcphdr);
#endif
/* remove header from payload */
if (pbuf_header(p, -((s16_t)(IPH_HL(iphdr) * 4))) || (p->tot_len < sizeof(struct tcp_hdr))) {
/* drop short packets */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet (%"U16_F" bytes) discarded\n", p->tot_len));
TCP_STATS_INC(tcp.lenerr);
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
/* Don't even process incoming broadcasts/multicasts. */
if (ip_addr_isbroadcast(&(iphdr->dest), inp) ||
ip_addr_ismulticast(&(iphdr->dest))) {
TCP_STATS_INC(tcp.proterr);
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
#if CHECKSUM_CHECK_TCP
/* Verify TCP checksum. */
if (inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src),
(struct ip_addr *)&(iphdr->dest),
IP_PROTO_TCP, p->tot_len) != 0) {
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packet discarded due to failing checksum 0x%04"X16_F"\n",
inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src), (struct ip_addr *)&(iphdr->dest),
IP_PROTO_TCP, p->tot_len)));
#if TCP_DEBUG
tcp_debug_print(tcphdr);
#endif /* TCP_DEBUG */
TCP_STATS_INC(tcp.chkerr);
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
#endif
/* Move the payload pointer in the pbuf so that it points to the
TCP data instead of the TCP header. */
hdrlen = TCPH_HDRLEN(tcphdr);
if(pbuf_header(p, -(hdrlen * 4))){
/* drop short packets */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet\n"));
TCP_STATS_INC(tcp.lenerr);
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
/* Convert fields in TCP header to host byte order. */
tcphdr->src = ntohs(tcphdr->src);
tcphdr->dest = ntohs(tcphdr->dest);
seqno = tcphdr->seqno = ntohl(tcphdr->seqno);
ackno = tcphdr->ackno = ntohl(tcphdr->ackno);
tcphdr->wnd = ntohs(tcphdr->wnd);
flags = TCPH_FLAGS(tcphdr) & TCP_FLAGS;
tcplen = p->tot_len + ((flags & TCP_FIN || flags & TCP_SYN)? 1: 0);
/* Demultiplex an incoming segment. First, we check if it is destined
for an active connection. */
prev = NULL;
for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) {
LWIP_ASSERT("tcp_input: active pcb->state != CLOSED", pcb->state != CLOSED);
LWIP_ASSERT("tcp_input: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT);
LWIP_ASSERT("tcp_input: active pcb->state != LISTEN", pcb->state != LISTEN);
if (pcb->remote_port == tcphdr->src &&
pcb->local_port == tcphdr->dest &&
ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)) &&
ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest))) {
/* Move this PCB to the front of the list so that subsequent
lookups will be faster (we exploit locality in TCP segment
arrivals). */
LWIP_ASSERT("tcp_input: pcb->next != pcb (before cache)", pcb->next != pcb);
if (prev != NULL) {
prev->next = pcb->next;
pcb->next = tcp_active_pcbs;
tcp_active_pcbs = pcb;
}
LWIP_ASSERT("tcp_input: pcb->next != pcb (after cache)", pcb->next != pcb);
break;
}
prev = pcb;
}
if (pcb == NULL) {
/* If it did not go to an active connection, we check the connections
in the TIME-WAIT state. */
for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) {
LWIP_ASSERT("tcp_input: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT);
if (pcb->remote_port == tcphdr->src &&
pcb->local_port == tcphdr->dest &&
ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)) &&
ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest))) {
/* We don't really care enough to move this PCB to the front
of the list since we are not very likely to receive that
many segments for connections in TIME-WAIT. */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for TIME_WAITing connection.\n"));
tcp_timewait_input(pcb);
pbuf_free(p);
return;
}
}
/* Finally, if we still did not get a match, we check all PCBs that
are LISTENing for incoming connections. */
prev = NULL;
for(lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) {
if ((ip_addr_isany(&(lpcb->local_ip)) ||
ip_addr_cmp(&(lpcb->local_ip), &(iphdr->dest))) &&
lpcb->local_port == tcphdr->dest) {
/* Move this PCB to the front of the list so that subsequent
lookups will be faster (we exploit locality in TCP segment
arrivals). */
if (prev != NULL) {
((struct tcp_pcb_listen *)prev)->next = lpcb->next;
/* our successor is the remainder of the listening list */
lpcb->next = tcp_listen_pcbs.listen_pcbs;
/* put this listening pcb at the head of the listening list */
tcp_listen_pcbs.listen_pcbs = lpcb;
}
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for LISTENing connection.\n"));
tcp_listen_input(lpcb);
pbuf_free(p);
return;
}
prev = (struct tcp_pcb *)lpcb;
}
}
#if TCP_INPUT_DEBUG
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("+-+-+-+-+-+-+-+-+-+-+-+-+-+- tcp_input: flags "));
tcp_debug_print_flags(TCPH_FLAGS(tcphdr));
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n"));
#endif /* TCP_INPUT_DEBUG */
if (pcb != NULL) {
/* The incoming segment belongs to a connection. */
#if TCP_INPUT_DEBUG
#if TCP_DEBUG
tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
#endif /* TCP_INPUT_DEBUG */
/* Set up a tcp_seg structure. */
inseg.next = NULL;
inseg.len = p->tot_len;
inseg.dataptr = p->payload;
inseg.p = p;
inseg.tcphdr = tcphdr;
recv_data = NULL;
recv_flags = 0;
/* If there is data which was previously "refused" by upper layer */
if (pcb->refused_data != NULL) {
/* Notify again application with data previously received. */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: notify kept packet\n"));
TCP_EVENT_RECV(pcb, pcb->refused_data, ERR_OK, err);
if (err == ERR_OK) {
pcb->refused_data = NULL;
} else {
/* drop incoming packets, because pcb is "full" */
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: drop incoming packets, because pcb is \"full\"\n"));
TCP_STATS_INC(tcp.drop);
snmp_inc_tcpinerrs();
pbuf_free(p);
return;
}
}
tcp_input_pcb = pcb;
err = tcp_process(pcb);
tcp_input_pcb = NULL;
/* A return value of ERR_ABRT means that tcp_abort() was called
and that the pcb has been freed. If so, we don't do anything. */
if (err != ERR_ABRT) {
if (recv_flags & TF_RESET) {
/* TF_RESET means that the connection was reset by the other
end. We then call the error callback to inform the
application that the connection is dead before we
deallocate the PCB. */
TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_RST);
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
} else if (recv_flags & TF_CLOSED) {
/* The connection has been closed and we will deallocate the
PCB. */
tcp_pcb_remove(&tcp_active_pcbs, pcb);
memp_free(MEMP_TCP_PCB, pcb);
} else {
err = ERR_OK;
/* If the application has registered a "sent" function to be
called when new send buffer space is available, we call it
now. */
if (pcb->acked > 0) {
TCP_EVENT_SENT(pcb, pcb->acked, err);
}
if (recv_data != NULL) {
if(flags & TCP_PSH) {
recv_data->flags |= PBUF_FLAG_PUSH;
}
/* Notify application that data has been received. */
TCP_EVENT_RECV(pcb, recv_data, ERR_OK, err);
/* If the upper layer can't receive this data, store it */
if (err != ERR_OK) {
pcb->refused_data = recv_data;
LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: keep incoming packet, because pcb is \"full\"\n"));
}
}
/* If a FIN segment was received, we call the callback
function with a NULL buffer to indicate EOF. */
if (recv_flags & TF_GOT_FIN) {
TCP_EVENT_RECV(pcb, NULL, ERR_OK, err);
}
/* If there were no errors, we try to send something out. */
if (err == ERR_OK) {
tcp_output(pcb);
}
}
}
/* give up our reference to inseg.p */
if (inseg.p != NULL)
{
pbuf_free(inseg.p);
inseg.p = NULL;
}
#if TCP_INPUT_DEBUG
#if TCP_DEBUG
tcp_debug_print_state(pcb->state);
#endif /* TCP_DEBUG */
#endif /* TCP_INPUT_DEBUG */
} else {
/* If no matching PCB was found, send a TCP RST (reset) to the
sender. */
LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_input: no PCB match found, resetting.\n"));
if (!(TCPH_FLAGS(tcphdr) & TCP_RST)) {
TCP_STATS_INC(tcp.proterr);
TCP_STATS_INC(tcp.drop);
tcp_rst(ackno, seqno + tcplen,
&(iphdr->dest), &(iphdr->src),
tcphdr->dest, tcphdr->src);
}
pbuf_free(p);
}
LWIP_ASSERT("tcp_input: tcp_pcbs_sane()", tcp_pcbs_sane());
PERF_STOP("tcp_input");
}
void ip6_input(struct pbuf *p, struct netif *inp) {
struct ip6_hdr *iphdr;
struct netif *netif;
PERF_START;
#if IP_DEBUG
ip6_debug_print(p);
#endif /* IP_DEBUG */
IP_STATS_INC(ip.recv);
/* identify the IP header */
iphdr = p->payload;
if (iphdr->v != 6) {
LWIP_DEBUGF(IP_DEBUG, ("IP packet dropped due to bad version number\n"));
#if IP_DEBUG
ip6_debug_print(p);
#endif /* IP_DEBUG */
pbuf_free(p);
IP_STATS_INC(ip.err);IP_STATS_INC(ip.drop);
return;
}
char forus = 0;
/* is this packet for us? */
for (netif = netif_list; netif != NULL; netif = netif->next) {
#if IP_DEBUG
LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest "));
ip6_addr_debug_print(IP_DEBUG, ((struct ip6_addr *)&(iphdr->dest)));
LWIP_DEBUGF(IP_DEBUG, ("netif->ip6_addr "));
ip6_addr_debug_print(IP_DEBUG, ((struct ip6_addr *)&(netif->ip6_addr)));
LWIP_DEBUGF(IP_DEBUG, ("\n\r"));
#endif /* IP_DEBUG */
if (ip6_addr_cmp(&(iphdr->dest), &(netif->ip6_addr))) {
forus = 1;
LWIP_DEBUGF(IP_DEBUG, ("ip6_input: packet for us: perfect match"));
break;
}
if (ip6_addr_issolicitedmulticast(&(iphdr->dest), &(netif->ip6_addr))) {
forus = 1;
LWIP_DEBUGF(IP_DEBUG, ("ip6_input: packet for us on solicited multicast address\n"));
break;
}
}
// check if it is a multicast address and we are listening on that address
if (ip6_addr_isallnodes(&(iphdr->dest)))
forus = 1;
if (forus == 0) {
/* packet not for us, route or discard */
LWIP_DEBUGF(IP_DEBUG, ("ip6_input: packet not for us.\n"));
#if IP_FORWARD
ip6_forward(p, iphdr);
#endif
pbuf_free(p);
return;
}
pbuf_realloc(p, IP6_HLEN + ntohs(iphdr->len));
/* send to upper layers */
#if IP_DEBUG
/* LWIP_DEBUGF("ip_input: \n");
ip_debug_print(p);
LWIP_DEBUGF("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len);*/
#endif /* IP_DEBUG */
/*if(pbuf_header(p, -IP6_HLEN)) {
LWIP_ASSERT("Can't move over header in packet", 0);
return;
}*/
switch (iphdr->nexthdr) {
#if LWIP_UDP
case IP6_PROTO_UDP:
udp_input(p, inp);
break;
#endif
#if LWIP_TCP
case IP6_PROTO_TCP:
tcp_input(p, inp);
break;
#endif
#if LWIP_ICMP
case IP6_PROTO_ICMP:
icmp6_input(p, inp);
break;
#endif /* LWIP_ICMP */
default:
#if LWIP_ICMP
/* send ICMP destination protocol unreachable */
icmp6_dest_unreach(p, ICMP_DUR_PROTO);
#endif /* LWIP_ICMP */
pbuf_free(p);
LWIP_DEBUGF(IP_DEBUG, ("Unsupported transport protocol %"U16_F"\n", iphdr->nexthdr));
IP_STATS_INC(ip.proterr);
IP_STATS_INC(ip.drop);
}PERF_STOP("ip_input");
}
