/**
* Outbound TTL/HOPL check.
*/
static int
pxudp_ttl_expired(struct pbuf *p)
{
int ttl;
if (ip_current_is_v6()) {
ttl = IP6H_HOPLIM(ip6_current_header());
}
else {
ttl = IPH_TTL(ip_current_header());
}
if (RT_UNLIKELY(ttl <= 1)) {
int status = pbuf_header(p, ip_current_header_tot_len() + UDP_HLEN);
if (RT_LIKELY(status == 0)) {
if (ip_current_is_v6()) {
icmp6_time_exceeded(p, ICMP6_TE_HL);
}
else {
icmp_time_exceeded(p, ICMP_TE_TTL);
}
}
pbuf_free(p);
return 1;
}
return 0;
}
static void
pxping_recv6(void *arg, struct pbuf *p)
{
struct pxping *pxping = (struct pxping *)arg;
struct icmp6_echo_hdr *icmph;
size_t bufsize;
struct pong6 *pong;
int mapped;
void *reqdata;
size_t reqsize;
struct sockaddr_in6 src, dst;
int hopl;
IP_OPTION_INFORMATION opts;
int status;
pong = NULL;
icmph = (struct icmp6_echo_hdr *)p->payload;
memset(&dst, 0, sizeof(dst));
dst.sin6_family = AF_INET6;
mapped = pxremap_outbound_ip6((ip6_addr_t *)&dst.sin6_addr,
ip6_current_dest_addr());
if (RT_UNLIKELY(mapped == PXREMAP_FAILED)) {
goto out;
}
hopl = IP6H_HOPLIM(ip6_current_header());
if (mapped == PXREMAP_ASIS) {
if (RT_UNLIKELY(hopl == 1)) {
status = pbuf_header(p, ip_current_header_tot_len());
if (RT_LIKELY(status == 0)) {
icmp6_time_exceeded(p, ICMP6_TE_HL);
}
goto out;
}
--hopl;
}
status = pbuf_header(p, -(u16_t)sizeof(*icmph)); /* to ping payload */
if (RT_UNLIKELY(status != 0)) {
goto out;
}
bufsize = sizeof(ICMPV6_ECHO_REPLY) + p->tot_len;
pong = (struct pong6 *)malloc(sizeof(*pong) - sizeof(pong->buf) + bufsize);
if (RT_UNLIKELY(pong == NULL)) {
goto out;
}
pong->bufsize = bufsize;
pong->netif = pxping->netif;
ip6_addr_copy(pong->reqsrc, *ip6_current_src_addr());
memcpy(&pong->reqicmph, icmph, sizeof(*icmph));
memset(pong->buf, 0xa5, pong->bufsize);
pong->reqsize = reqsize = p->tot_len;
if (p->next == NULL) {
/* single pbuf can be directly used as request data source */
reqdata = p->payload;
}
else {
/* data from pbuf chain must be concatenated */
pbuf_copy_partial(p, pong->buf, p->tot_len, 0);
reqdata = pong->buf;
}
memset(&src, 0, sizeof(src));
src.sin6_family = AF_INET6;
src.sin6_addr = in6addr_any; /* let the OS select host source address */
memset(&opts, 0, sizeof(opts));
opts.Ttl = hopl;
status = Icmp6SendEcho2(pxping->hdl6, NULL,
pxping->callback6, pong,
&src, &dst, reqdata, (WORD)reqsize, &opts,
pong->buf, (DWORD)pong->bufsize,
5 * 1000 /* ms */);
if (RT_UNLIKELY(status != 0)) {
DPRINTF(("Icmp6SendEcho2: unexpected status %d\n", status));
goto out;
}
else if ((status = GetLastError()) != ERROR_IO_PENDING) {
int code;
DPRINTF(("Icmp6SendEcho2: error %d\n", status));
switch (status) {
case ERROR_NETWORK_UNREACHABLE:
case ERROR_HOST_UNREACHABLE:
code = ICMP6_DUR_NO_ROUTE;
break;
default:
code = -1;
break;
}
if (code != -1) {
/* move payload back to IP header */
status = pbuf_header(p, (u16_t)(sizeof(*icmph)
+ ip_current_header_tot_len()));
if (RT_LIKELY(status == 0)) {
icmp6_dest_unreach(p, code);
}
}
goto out;
}
pong = NULL; /* callback owns it now */
out:
if (pong != NULL) {
free(pong);
}
pbuf_free(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 {
/**
* ICMP Echo Request in pbuf "p" is to be proxied.
*/
static void
pxping_recv4(void *arg, struct pbuf *p)
{
struct pxping *pxping = (struct pxping *)arg;
const struct ip_hdr *iph;
const struct icmp_echo_hdr *icmph;
u16_t iphlen;
size_t bufsize;
struct pong4 *pong;
IPAddr dst;
int mapped;
int ttl;
IP_OPTION_INFORMATION opts;
void *reqdata;
size_t reqsize;
int status;
pong = NULL;
iphlen = ip_current_header_tot_len();
if (RT_UNLIKELY(iphlen != IP_HLEN)) { /* we don't do options */
goto out;
}
iph = (const struct ip_hdr *)ip_current_header();
icmph = (const struct icmp_echo_hdr *)p->payload;
mapped = pxremap_outbound_ip4((ip_addr_t *)&dst, (ip_addr_t *)&iph->dest);
if (RT_UNLIKELY(mapped == PXREMAP_FAILED)) {
goto out;
}
ttl = IPH_TTL(iph);
if (mapped == PXREMAP_ASIS) {
if (RT_UNLIKELY(ttl == 1)) {
status = pbuf_header(p, iphlen); /* back to IP header */
if (RT_LIKELY(status == 0)) {
icmp_time_exceeded(p, ICMP_TE_TTL);
}
goto out;
}
--ttl;
}
status = pbuf_header(p, -(u16_t)sizeof(*icmph)); /* to ping payload */
if (RT_UNLIKELY(status != 0)) {
goto out;
}
bufsize = sizeof(ICMP_ECHO_REPLY) + p->tot_len;
pong = (struct pong4 *)malloc(sizeof(*pong) - sizeof(pong->buf) + bufsize);
if (RT_UNLIKELY(pong == NULL)) {
goto out;
}
pong->bufsize = bufsize;
pong->netif = pxping->netif;
memcpy(&pong->reqiph, iph, sizeof(*iph));
memcpy(&pong->reqicmph, icmph, sizeof(*icmph));
reqsize = p->tot_len;
if (p->next == NULL) {
/* single pbuf can be directly used as request data source */
reqdata = p->payload;
}
else {
/* data from pbuf chain must be concatenated */
pbuf_copy_partial(p, pong->buf, p->tot_len, 0);
reqdata = pong->buf;
}
opts.Ttl = ttl;
opts.Tos = IPH_TOS(iph); /* affected by DisableUserTOSSetting key */
opts.Flags = (IPH_OFFSET(iph) & PP_HTONS(IP_DF)) != 0 ? IP_FLAG_DF : 0;
opts.OptionsSize = 0;
opts.OptionsData = 0;
status = IcmpSendEcho2(pxping->hdl4, NULL,
pxping->callback4, pong,
dst, reqdata, (WORD)reqsize, &opts,
pong->buf, (DWORD)pong->bufsize,
5 * 1000 /* ms */);
if (RT_UNLIKELY(status != 0)) {
DPRINTF(("IcmpSendEcho2: unexpected status %d\n", status));
goto out;
}
else if ((status = GetLastError()) != ERROR_IO_PENDING) {
int code;
DPRINTF(("IcmpSendEcho2: error %d\n", status));
switch (status) {
case ERROR_NETWORK_UNREACHABLE:
code = ICMP_DUR_NET;
break;
case ERROR_HOST_UNREACHABLE:
code = ICMP_DUR_HOST;
break;
default:
code = -1;
break;
}
if (code != -1) {
/* move payload back to IP header */
status = pbuf_header(p, (u16_t)(sizeof(*icmph) + iphlen));
if (RT_LIKELY(status == 0)) {
icmp_dest_unreach(p, code);
}
}
goto out;
}
pong = NULL; /* callback owns it now */
out:
if (pong != NULL) {
free(pong);
}
pbuf_free(p);
}
