/** Calls tcp_input() after adjusting current_iphdr_dest */
void test_tcp_input(struct pbuf *p, struct netif *inp)
{
struct ip_hdr *iphdr = (struct ip_hdr*)p->payload;
/* these lines are a hack, don't use them as an example :-) */
ip_addr_copy_from_ip4(*ip_current_dest_addr(), iphdr->dest);
ip_addr_copy_from_ip4(*ip_current_src_addr(), iphdr->src);
ip_current_netif() = inp;
ip_data.current_ip4_header = iphdr;
/* since adding IPv6, p->payload must point to tcp header, not ip header */
pbuf_header(p, -(s16_t)sizeof(struct ip_hdr));
tcp_input(p, inp);
ip_addr_set_zero(ip_current_dest_addr());
ip_addr_set_zero(ip_current_src_addr());
ip_current_netif() = NULL;
ip_data.current_ip4_header = NULL;
}
/**
* 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 (p->payload pointing to the UDP header)
* @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;
u16_t src, dest;
u8_t broadcast;
u8_t for_us = 0;
LWIP_UNUSED_ARG(inp);
PERF_START;
UDP_STATS_INC(udp.recv);
/* Check minimum length (UDP header) */
if (p->len < UDP_HLEN) {
/* 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);
MIB2_STATS_INC(mib2.udpinerrors);
pbuf_free(p);
goto end;
}
udphdr = (struct udp_hdr *)p->payload;
/* is broadcast packet ? */
broadcast = ip_addr_isbroadcast(ip_current_dest_addr(), ip_current_netif());
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 = lwip_ntohs(udphdr->src);
dest = lwip_ntohs(udphdr->dest);
udp_debug_print(udphdr);
/* print the UDP source and destination */
LWIP_DEBUGF(UDP_DEBUG, ("udp ("));
ip_addr_debug_print(UDP_DEBUG, ip_current_dest_addr());
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", lwip_ntohs(udphdr->dest)));
ip_addr_debug_print(UDP_DEBUG, ip_current_src_addr());
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F")\n", lwip_ntohs(udphdr->src)));
pcb = NULL;
prev = NULL;
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) {
/* print the PCB local and remote address */
LWIP_DEBUGF(UDP_DEBUG, ("pcb ("));
ip_addr_debug_print(UDP_DEBUG, &pcb->local_ip);
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", pcb->local_port));
ip_addr_debug_print(UDP_DEBUG, &pcb->remote_ip);
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F")\n", pcb->remote_port));
/* compare PCB local addr+port to UDP destination addr+port */
if ((pcb->local_port == dest) &&
(udp_input_local_match(pcb, inp, broadcast) != 0)) {
if (((pcb->flags & UDP_FLAGS_CONNECTED) == 0) &&
((uncon_pcb == NULL)
#if SO_REUSE
/* prefer specific IPs over cath-all */
|| !ip_addr_isany(&pcb->local_ip)
#endif /* SO_REUSE */
)) {
/* the first unconnected matching PCB */
uncon_pcb = pcb;
}
/* compare PCB remote addr+port to UDP source addr+port */
if ((pcb->remote_port == src) &&
(ip_addr_isany_val(pcb->remote_ip) ||
ip_addr_cmp(&pcb->remote_ip, ip_current_src_addr()))) {
/* 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;
}
}
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) {
for_us = 1;
} else {
#if LWIP_IPV6
if (ip_current_is_v6()) {
for_us = netif_get_ip6_addr_match(inp, ip6_current_dest_addr()) >= 0;
}
#endif /* LWIP_IPV6 */
#if LWIP_IPV4
if (!ip_current_is_v6()) {
for_us = ip4_addr_cmp(netif_ip4_addr(inp), ip4_current_dest_addr());
}
#endif /* LWIP_IPV4 */
}
if (for_us) {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
#if CHECKSUM_CHECK_UDP
IF__NETIF_CHECKSUM_ENABLED(inp, CHECKSUM_CHECK_UDP) {
#if LWIP_UDPLITE
if (ip_current_header_proto() == IP_PROTO_UDPLITE) {
/* Do the UDP Lite checksum */
u16_t chklen = lwip_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) */
goto chkerr;
}
}
if (ip_chksum_pseudo_partial(p, IP_PROTO_UDPLITE,
p->tot_len, chklen,
ip_current_src_addr(), ip_current_dest_addr()) != 0) {
goto chkerr;
}
} else
#endif /* LWIP_UDPLITE */
{
if (udphdr->chksum != 0) {
if (ip_chksum_pseudo(p, IP_PROTO_UDP, p->tot_len,
ip_current_src_addr(),
ip_current_dest_addr()) != 0) {
goto chkerr;
}
}
}
}
#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);
MIB2_STATS_INC(mib2.udpinerrors);
pbuf_free(p);
goto end;
}
if (pcb != NULL) {
MIB2_STATS_INC(mib2.udpindatagrams);
#if SO_REUSE && SO_REUSE_RXTOALL
if (ip_get_option(pcb, SOF_REUSEADDR) &&
(broadcast || ip_addr_ismulticast(ip_current_dest_addr()))) {
/* pass broadcast- or multicast packets to all multicast pcbs
if SOF_REUSEADDR is set on the first match */
struct udp_pcb *mpcb;
u8_t p_header_changed = 0;
s16_t hdrs_len = (s16_t)(ip_current_header_tot_len() + UDP_HLEN);
for (mpcb = udp_pcbs; mpcb != NULL; mpcb = mpcb->next) {
if (mpcb != pcb) {
/* compare PCB local addr+port to UDP destination addr+port */
if ((mpcb->local_port == dest) &&
(udp_input_local_match(mpcb, inp, broadcast) != 0)) {
/* pass a copy of the packet to all local matches */
if (mpcb->recv != NULL) {
struct pbuf *q;
/* for that, move payload to IP header again */
if (p_header_changed == 0) {
pbuf_header_force(p, hdrs_len);
p_header_changed = 1;
}
q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
if (q != NULL) {
err_t err = pbuf_copy(q, p);
if (err == ERR_OK) {
/* move payload to UDP data */
pbuf_header(q, -hdrs_len);
mpcb->recv(mpcb->recv_arg, mpcb, q, ip_current_src_addr(), src);
}
}
}
}
}
}
if (p_header_changed) {
/* and move payload to UDP data again */
pbuf_header(p, -hdrs_len);
}
}
#endif /* SO_REUSE && SO_REUSE_RXTOALL */
/* callback */
if (pcb->recv != NULL) {
/* now the recv function is responsible for freeing p */
pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr(), 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 || LWIP_ICMP6
/* No match was found, send ICMP destination port unreachable unless
destination address was broadcast/multicast. */
if (!broadcast && !ip_addr_ismulticast(ip_current_dest_addr())) {
/* move payload pointer back to ip header */
pbuf_header_force(p, ip_current_header_tot_len() + UDP_HLEN);
icmp_port_unreach(ip_current_is_v6(), p);
}
#endif /* LWIP_ICMP || LWIP_ICMP6 */
UDP_STATS_INC(udp.proterr);
UDP_STATS_INC(udp.drop);
MIB2_STATS_INC(mib2.udpnoports);
pbuf_free(p);
}
} else {
/**
* Send an ICMPv6 packet in response to an incoming packet.
*
* @param p the input packet for which the response should be sent,
* p->payload pointing to the IPv6 header
* @param code Code of the ICMPv6 header
* @param data Additional 32-bit parameter in the ICMPv6 header
* @param type Type of the ICMPv6 header
*/
static void
icmp6_send_response(struct pbuf *p, u8_t code, u32_t data, u8_t type)
{
struct pbuf *q;
struct icmp6_hdr *icmp6hdr;
ip6_addr_t *reply_src, *reply_dest;
ip6_addr_t reply_src_local, reply_dest_local;
struct ip6_hdr *ip6hdr;
struct interface *netif;
/* ICMPv6 header + IPv6 header + data */
q = pbuf_alloc(PBUF_IP, sizeof(struct icmp6_hdr) + IP6_HLEN + LWIP_ICMP6_DATASIZE,
PBUF_RAM);
if (q == NULL) {
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_time_exceeded: failed to allocate pbuf for ICMPv6 packet.\n"));
ICMP6_STATS_INC(icmp6.memerr);
return;
}
LWIP_ASSERT("check that first pbuf can hold icmp 6message",
(q->len >= (sizeof(struct icmp6_hdr) + IP6_HLEN + LWIP_ICMP6_DATASIZE)));
icmp6hdr = (struct icmp6_hdr *)q->payload;
icmp6hdr->type = type;
icmp6hdr->code = code;
icmp6hdr->data = data;
/* copy fields from original packet */
SMEMCPY((u8_t *)q->payload + sizeof(struct icmp6_hdr), (u8_t *)p->payload,
IP6_HLEN + LWIP_ICMP6_DATASIZE);
/* Get the destination address and netif for this ICMP message. */
if ((ip_current_netif() == NULL) ||
((code == ICMP6_TE_FRAG) && (type == ICMP6_TYPE_TE))) {
/* Special case, as ip6_current_xxx is either NULL, or points
* to a different packet than the one that expired.
* We must use the addresses that are stored in the expired packet. */
ip6hdr = (struct ip6_hdr *)p->payload;
/* copy from packed address to aligned address */
ip6_addr_copy(reply_dest_local, ip6hdr->src);
ip6_addr_copy(reply_src_local, ip6hdr->dest);
reply_dest = &reply_dest_local;
reply_src = &reply_src_local;
netif = ip6_route(reply_src, reply_dest);
if (netif == NULL) {
/* drop */
pbuf_free(q);
ICMP6_STATS_INC(icmp6.rterr);
return;
}
}
else {
netif = ip_current_netif();
reply_dest = ip6_current_src_addr();
/* Select an address to use as source. */
reply_src = ip6_select_source_address(netif, reply_dest);
if (reply_src == NULL) {
/* drop */
pbuf_free(q);
ICMP6_STATS_INC(icmp6.rterr);
return;
}
}
/* calculate checksum */
icmp6hdr->chksum = 0;
icmp6hdr->chksum = ip6_chksum_pseudo(q, IP6_NEXTH_ICMP6, q->tot_len,
reply_src, reply_dest);
ICMP6_STATS_INC(icmp6.xmit);
ip6_output_if(q, reply_src, reply_dest, LWIP_ICMP6_HL, 0, IP6_NEXTH_ICMP6, netif);
pbuf_free(q);
}
/**
* 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
raw_input(struct pbuf *p, struct netif *inp)
{
struct raw_pcb *pcb, *prev;
s16_t proto;
u8_t eaten = 0;
u8_t broadcast = ip_addr_isbroadcast(ip_current_dest_addr(), ip_current_netif());
LWIP_UNUSED_ARG(inp);
#if LWIP_IPV6
#if LWIP_IPV4
if (IP_HDR_GET_VERSION(p->payload) == 6)
#endif /* LWIP_IPV4 */
{
struct ip6_hdr *ip6hdr = (struct ip6_hdr *)p->payload;
proto = IP6H_NEXTH(ip6hdr);
}
#if LWIP_IPV4
else
#endif /* LWIP_IPV4 */
#endif /* LWIP_IPV6 */
#if LWIP_IPV4
{
proto = IPH_PROTO((struct ip_hdr *)p->payload);
}
#endif /* LWIP_IPV4 */
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) && raw_input_match(pcb, broadcast)) {
/* receive callback function available? */
if (pcb->recv != NULL) {
#ifndef LWIP_NOASSERT
void* old_payload = p->payload;
#endif
/* the receive callback function did not eat the packet? */
eaten = pcb->recv(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;
}
/**
* Processes ICMP input packets, called from ip_input().
*
* Currently only processes icmp echo requests and sends
* out the echo response.
*
* @param p the icmp echo request packet, p->payload pointing to the icmp header
* @param inp the netif on which this packet was received
*/
void
icmp_input(struct pbuf *p, struct netif *inp)
{
u8_t type;
#ifdef LWIP_DEBUG
u8_t code;
#endif /* LWIP_DEBUG */
struct icmp_echo_hdr *iecho;
const struct ip_hdr *iphdr_in;
struct ip_hdr *iphdr;
s16_t hlen;
const ip4_addr_t* src;
ICMP_STATS_INC(icmp.recv);
MIB2_STATS_INC(mib2.icmpinmsgs);
iphdr_in = ip4_current_header();
hlen = IPH_HL(iphdr_in) * 4;
if (p->len < sizeof(u16_t)*2) {
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: short ICMP (%"U16_F" bytes) received\n", p->tot_len));
goto lenerr;
}
type = *((u8_t *)p->payload);
#ifdef LWIP_DEBUG
code = *(((u8_t *)p->payload)+1);
#endif /* LWIP_DEBUG */
switch (type) {
case ICMP_ER:
/* This is OK, echo reply might have been parsed by a raw PCB
(as obviously, an echo request has been sent, too). */
break;
case ICMP_ECHO:
src = ip4_current_dest_addr();
/* multicast destination address? */
if (ip_addr_ismulticast(ip_current_dest_addr())) {
#if LWIP_MULTICAST_PING
/* For multicast, use address of receiving interface as source address */
src = netif_ip4_addr(inp);
#else /* LWIP_MULTICAST_PING */
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to multicast pings\n"));
goto icmperr;
#endif /* LWIP_MULTICAST_PING */
}
/* broadcast destination address? */
if (ip_addr_isbroadcast(ip_current_dest_addr(), ip_current_netif())) {
#if LWIP_BROADCAST_PING
/* For broadcast, use address of receiving interface as source address */
src = netif_ip4_addr(inp);
#else /* LWIP_BROADCAST_PING */
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: Not echoing to broadcast pings\n"));
goto icmperr;
#endif /* LWIP_BROADCAST_PING */
}
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ping\n"));
if (p->tot_len < sizeof(struct icmp_echo_hdr)) {
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: bad ICMP echo received\n"));
goto lenerr;
}
#if CHECKSUM_CHECK_ICMP
IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_ICMP) {
if (inet_chksum_pbuf(p) != 0) {
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: checksum failed for received ICMP echo\n"));
pbuf_free(p);
ICMP_STATS_INC(icmp.chkerr);
MIB2_STATS_INC(mib2.icmpinerrors);
return;
}
}
#endif
#if LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN
if (pbuf_header(p, (PBUF_IP_HLEN + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
/* p is not big enough to contain link headers
* allocate a new one and copy p into it
*/
struct pbuf *r;
/* allocate new packet buffer with space for link headers */
r = pbuf_alloc(PBUF_LINK, p->tot_len + hlen, PBUF_RAM);
if (r == NULL) {
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: allocating new pbuf failed\n"));
goto icmperr;
}
LWIP_ASSERT("check that first pbuf can hold struct the ICMP header",
(r->len >= hlen + sizeof(struct icmp_echo_hdr)));
/* copy the ip header */
MEMCPY(r->payload, iphdr_in, hlen);
iphdr = (struct ip_hdr *)r->payload;
/* switch r->payload back to icmp header */
if (pbuf_header(r, -hlen)) {
LWIP_ASSERT("icmp_input: moving r->payload to icmp header failed\n", 0);
goto icmperr;
}
/* copy the rest of the packet without ip header */
if (pbuf_copy(r, p) != ERR_OK) {
LWIP_ASSERT("icmp_input: copying to new pbuf failed\n", 0);
goto icmperr;
}
/* free the original p */
pbuf_free(p);
/* we now have an identical copy of p that has room for link headers */
p = r;
} else {
/* restore p->payload to point to icmp header */
if (pbuf_header(p, -(s16_t)(PBUF_IP_HLEN + PBUF_LINK_HLEN + PBUF_LINK_ENCAPSULATION_HLEN))) {
LWIP_ASSERT("icmp_input: restoring original p->payload failed\n", 0);
goto icmperr;
}
}
#endif /* LWIP_ICMP_ECHO_CHECK_INPUT_PBUF_LEN */
/* At this point, all checks are OK. */
/* We generate an answer by switching the dest and src ip addresses,
* setting the icmp type to ECHO_RESPONSE and updating the checksum. */
iecho = (struct icmp_echo_hdr *)p->payload;
if(pbuf_header(p, hlen)) {
LWIP_ASSERT("Can't move over header in packet", 0);
} else {
err_t ret;
iphdr = (struct ip_hdr*)p->payload;
ip4_addr_copy(iphdr->src, *src);
ip4_addr_copy(iphdr->dest, *ip4_current_src_addr());
ICMPH_TYPE_SET(iecho, ICMP_ER);
#if CHECKSUM_GEN_ICMP
IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_ICMP) {
/* adjust the checksum */
if (iecho->chksum > PP_HTONS(0xffffU - (ICMP_ECHO << 8))) {
iecho->chksum += PP_HTONS(ICMP_ECHO << 8) + 1;
} else {
iecho->chksum += PP_HTONS(ICMP_ECHO << 8);
}
}
#if LWIP_CHECKSUM_CTRL_PER_NETIF
else {
iecho->chksum = 0;
}
#endif /* LWIP_CHECKSUM_CTRL_PER_NETIF */
#else /* CHECKSUM_GEN_ICMP */
iecho->chksum = 0;
#endif /* CHECKSUM_GEN_ICMP */
/* Set the correct TTL and recalculate the header checksum. */
IPH_TTL_SET(iphdr, ICMP_TTL);
IPH_CHKSUM_SET(iphdr, 0);
#if CHECKSUM_GEN_IP
IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_GEN_IP) {
IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
}
#endif /* CHECKSUM_GEN_IP */
ICMP_STATS_INC(icmp.xmit);
/* increase number of messages attempted to send */
MIB2_STATS_INC(mib2.icmpoutmsgs);
/* increase number of echo replies attempted to send */
MIB2_STATS_INC(mib2.icmpoutechoreps);
/* send an ICMP packet */
ret = ip4_output_if(p, src, IP_HDRINCL,
ICMP_TTL, 0, IP_PROTO_ICMP, inp);
if (ret != ERR_OK) {
LWIP_DEBUGF(ICMP_DEBUG, ("icmp_input: ip_output_if returned an error: %c.\n", ret));
}
}
