/** Create a TCP segment usable for passing to tcp_input */
static struct pbuf*
tcp_create_segment_wnd(ip_addr_t* src_ip, ip_addr_t* dst_ip,
u16_t src_port, u16_t dst_port, void* data, size_t data_len,
u32_t seqno, u32_t ackno, u8_t headerflags, u16_t wnd)
{
struct pbuf *p, *q;
struct ip_hdr* iphdr;
struct tcp_hdr* tcphdr;
u16_t pbuf_len = (u16_t)(sizeof(struct ip_hdr) + sizeof(struct tcp_hdr) + data_len);
LWIP_ASSERT("data_len too big", data_len <= 0xFFFF);
p = pbuf_alloc(PBUF_RAW, pbuf_len, PBUF_POOL);
EXPECT_RETNULL(p != NULL);
/* first pbuf must be big enough to hold the headers */
EXPECT_RETNULL(p->len >= (sizeof(struct ip_hdr) + sizeof(struct tcp_hdr)));
if (data_len > 0) {
/* first pbuf must be big enough to hold at least 1 data byte, too */
EXPECT_RETNULL(p->len > (sizeof(struct ip_hdr) + sizeof(struct tcp_hdr)));
}
for(q = p; q != NULL; q = q->next) {
memset(q->payload, 0, q->len);
}
iphdr = (struct ip_hdr*)p->payload;
/* fill IP header */
iphdr->dest.addr = ip_2_ip4(dst_ip)->addr;
iphdr->src.addr = ip_2_ip4(src_ip)->addr;
IPH_VHL_SET(iphdr, 4, IP_HLEN / 4);
IPH_TOS_SET(iphdr, 0);
IPH_LEN_SET(iphdr, htons(p->tot_len));
IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, IP_HLEN));
/* let p point to TCP header */
pbuf_header(p, -(s16_t)sizeof(struct ip_hdr));
tcphdr = (struct tcp_hdr*)p->payload;
tcphdr->src = htons(src_port);
tcphdr->dest = htons(dst_port);
tcphdr->seqno = htonl(seqno);
tcphdr->ackno = htonl(ackno);
TCPH_HDRLEN_SET(tcphdr, sizeof(struct tcp_hdr)/4);
TCPH_FLAGS_SET(tcphdr, headerflags);
tcphdr->wnd = htons(wnd);
if (data_len > 0) {
/* let p point to TCP data */
pbuf_header(p, -(s16_t)sizeof(struct tcp_hdr));
/* copy data */
pbuf_take(p, data, (u16_t)data_len);
/* let p point to TCP header again */
pbuf_header(p, sizeof(struct tcp_hdr));
}
/* calculate checksum */
tcphdr->chksum = ip_chksum_pseudo(p,
IP_PROTO_TCP, p->tot_len, src_ip, dst_ip);
pbuf_header(p, sizeof(struct ip_hdr));
return p;
}
/**
* 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 {
END_TEST
/** Check that we handle malformed tcp headers, and discard the pbuf(s) */
START_TEST(test_tcp_malformed_header)
{
struct test_tcp_counters counters;
struct tcp_pcb* pcb;
struct pbuf* p;
char data[] = {1, 2, 3, 4};
ip_addr_t remote_ip, local_ip, netmask;
u16_t data_len, chksum;
u16_t remote_port = 0x100, local_port = 0x101;
struct netif netif;
struct test_tcp_txcounters txcounters;
struct tcp_hdr *hdr;
LWIP_UNUSED_ARG(_i);
/* initialize local vars */
memset(&netif, 0, sizeof(netif));
IP_ADDR4(&local_ip, 192, 168, 1, 1);
IP_ADDR4(&remote_ip, 192, 168, 1, 2);
IP_ADDR4(&netmask, 255, 255, 255, 0);
test_tcp_init_netif(&netif, &txcounters, &local_ip, &netmask);
data_len = sizeof(data);
/* initialize counter struct */
memset(&counters, 0, sizeof(counters));
counters.expected_data_len = data_len;
counters.expected_data = data;
/* create and initialize the pcb */
pcb = test_tcp_new_counters_pcb(&counters);
EXPECT_RET(pcb != NULL);
tcp_set_state(pcb, ESTABLISHED, &local_ip, &remote_ip, local_port, remote_port);
/* create a segment */
p = tcp_create_rx_segment(pcb, counters.expected_data, data_len, 0, 0, 0);
pbuf_header(p, -(s16_t)sizeof(struct ip_hdr));
hdr = (struct tcp_hdr *)p->payload;
TCPH_HDRLEN_FLAGS_SET(hdr, 15, 0x3d1);
hdr->chksum = 0;
chksum = ip_chksum_pseudo(p, IP_PROTO_TCP, p->tot_len,
&remote_ip, &local_ip);
hdr->chksum = chksum;
pbuf_header(p, sizeof(struct ip_hdr));
EXPECT(p != NULL);
EXPECT(p->next == NULL);
if (p != NULL) {
/* pass the segment to tcp_input */
test_tcp_input(p, &netif);
/* check if counters are as expected */
EXPECT(counters.close_calls == 0);
EXPECT(counters.recv_calls == 0);
EXPECT(counters.recved_bytes == 0);
EXPECT(counters.err_calls == 0);
}
/* make sure the pcb is freed */
EXPECT(lwip_stats.memp[MEMP_TCP_PCB].used == 1);
tcp_abort(pcb);
EXPECT(lwip_stats.memp[MEMP_TCP_PCB].used == 0);
}
