/**
* 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");
}
/**
* This function is called by the network interface device driver when
* an IP packet is received. The function does the basic checks of the
* IP header such as packet size being at least larger than the header
* size etc. If the packet was not destined for us, the packet is
* forwarded (using ip_forward). The IP checksum is always checked.
*
* Finally, the packet is sent to the upper layer protocol input function.
*
* @param p the received IP packet (p->payload points to IP header)
* @param inp the netif on which this packet was received
* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
* processed, but currently always returns ERR_OK)
*/
err_t
ip_input(struct pbuf *p, struct netif *inp)
{
struct ip_hdr *iphdr;
struct netif *netif;
u16_t iphdr_hlen;
u16_t iphdr_len;
#if LWIP_DHCP
int check_ip_src=1;
#endif /* LWIP_DHCP */
IP_STATS_INC(ip.recv);
snmp_inc_ipinreceives();
/* identify the IP header */
iphdr = p->payload;
if (IPH_V(iphdr) != 4) {
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
ip_debug_print(p);
pbuf_free(p);
IP_STATS_INC(ip.err);
IP_STATS_INC(ip.drop);
snmp_inc_ipinhdrerrors();
return ERR_OK;
}
/* obtain IP header length in number of 32-bit words */
iphdr_hlen = IPH_HL(iphdr);
/* calculate IP header length in bytes */
iphdr_hlen *= 4;
/* obtain ip length in bytes */
iphdr_len = ntohs(IPH_LEN(iphdr));
/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len)) {
if (iphdr_hlen > p->len) {
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
iphdr_hlen, p->len));
}
if (iphdr_len > p->tot_len) {
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
iphdr_len, p->tot_len));
}
/* free (drop) packet pbufs */
pbuf_free(p);
IP_STATS_INC(ip.lenerr);
IP_STATS_INC(ip.drop);
snmp_inc_ipindiscards();
return ERR_OK;
}
/* verify checksum */
#if CHECKSUM_CHECK_IP
if (inet_chksum(iphdr, iphdr_hlen) != 0) {
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
ip_debug_print(p);
pbuf_free(p);
IP_STATS_INC(ip.chkerr);
IP_STATS_INC(ip.drop);
snmp_inc_ipinhdrerrors();
return ERR_OK;
}
#endif
/* Trim pbuf. This should have been done at the netif layer,
* but we'll do it anyway just to be sure that its done. */
pbuf_realloc(p, iphdr_len);
/* match packet against an interface, i.e. is this packet for us? */
#if LWIP_IGMP
if (ip_addr_ismulticast(&(iphdr->dest))) {
if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &(iphdr->dest)))) {
netif = inp;
} else {
netif = NULL;
}
} else
#endif /* LWIP_IGMP */
{
/* start trying with inp. if that's not acceptable, start walking the
list of configured netifs.
'first' is used as a boolean to mark whether we started walking the list */
int first = 1;
netif = inp;
do {
LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%"X32_F" netif->ip_addr 0x%"X32_F" (0x%"X32_F", 0x%"X32_F", 0x%"X32_F")\n",
iphdr->dest.addr, netif->ip_addr.addr,
iphdr->dest.addr & netif->netmask.addr,
netif->ip_addr.addr & netif->netmask.addr,
iphdr->dest.addr & ~(netif->netmask.addr)));
/* interface is up and configured? */
if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
/* unicast to this interface address? */
if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr)) ||
/* or broadcast on this interface network address? */
ip_addr_isbroadcast(&(iphdr->dest), netif)) {
LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
netif->name[0], netif->name[1]));
/* break out of for loop */
break;
}
}
if (first) {
first = 0;
netif = netif_list;
} else {
netif = netif->next;
}
if (netif == inp) {
netif = netif->next;
}
} while(netif != NULL);
}
#if LWIP_DHCP
/* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
* using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
* According to RFC 1542 section 3.1.1, referred by RFC 2131).
*/
if (netif == NULL) {
/* remote port is DHCP server? */
if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen))->dest)));
if (ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen))->dest) == DHCP_CLIENT_PORT) {
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n"));
netif = inp;
check_ip_src = 0;
}
}
}
#endif /* LWIP_DHCP */
/* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
#if LWIP_DHCP
/* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
if (check_ip_src && (iphdr->src.addr != 0))
#endif /* LWIP_DHCP */
{ if ((ip_addr_isbroadcast(&(iphdr->src), inp)) ||
(ip_addr_ismulticast(&(iphdr->src)))) {
/* packet source is not valid */
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("ip_input: packet source is not valid.\n"));
/* free (drop) packet pbufs */
pbuf_free(p);
IP_STATS_INC(ip.drop);
snmp_inc_ipinaddrerrors();
snmp_inc_ipindiscards();
return ERR_OK;
}
}
/* packet not for us? */
if (netif == NULL) {
/* packet not for us, route or discard */
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: packet not for us.\n"));
#if IP_FORWARD
/* non-broadcast packet? */
if (!ip_addr_isbroadcast(&(iphdr->dest), inp)) {
/* try to forward IP packet on (other) interfaces */
ip_forward(p, iphdr, inp);
} else
#endif /* IP_FORWARD */
{
snmp_inc_ipinaddrerrors();
snmp_inc_ipindiscards();
}
pbuf_free(p);
return ERR_OK;
}
/* packet consists of multiple fragments? */
if ((IPH_OFFSET(iphdr) & htons(IP_OFFMASK | IP_MF)) != 0) {
#if IP_REASSEMBLY /* packet fragment reassembly code present? */
LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04"X16_F" tot_len=%"U16_F" len=%"U16_F" MF=%"U16_F" offset=%"U16_F"), calling ip_reass()\n",
ntohs(IPH_ID(iphdr)), p->tot_len, ntohs(IPH_LEN(iphdr)), !!(IPH_OFFSET(iphdr) & htons(IP_MF)), (ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)*8));
/* reassemble the packet*/
p = ip_reass(p);
/* packet not fully reassembled yet? */
if (p == NULL) {
return ERR_OK;
}
iphdr = p->payload;
#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
pbuf_free(p);
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
ntohs(IPH_OFFSET(iphdr))));
IP_STATS_INC(ip.opterr);
IP_STATS_INC(ip.drop);
/* unsupported protocol feature */
snmp_inc_ipinunknownprotos();
return ERR_OK;
#endif /* IP_REASSEMBLY */
}
#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
#if LWIP_IGMP
/* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
if((iphdr_hlen > IP_HLEN && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
#else
if (iphdr_hlen > IP_HLEN) {
#endif /* LWIP_IGMP */
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
pbuf_free(p);
IP_STATS_INC(ip.opterr);
IP_STATS_INC(ip.drop);
/* unsupported protocol feature */
snmp_inc_ipinunknownprotos();
return ERR_OK;
}
#endif /* IP_OPTIONS_ALLOWED == 0 */
/* send to upper layers */
LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
ip_debug_print(p);
LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
current_netif = inp;
current_header = iphdr;
#if LWIP_RAW
/* raw input did not eat the packet? */
if (raw_input(p, inp) == 0)
#endif /* LWIP_RAW */
{
switch (IPH_PROTO(iphdr)) {
#if LWIP_UDP
case IP_PROTO_UDP:
#if LWIP_UDPLITE
case IP_PROTO_UDPLITE:
#endif /* LWIP_UDPLITE */
snmp_inc_ipindelivers();
udp_input(p, inp);
break;
#endif /* LWIP_UDP */
#if LWIP_TCP
case IP_PROTO_TCP:
snmp_inc_ipindelivers();
tcp_input(p, inp);
break;
#endif /* LWIP_TCP */
#if LWIP_ICMP
case IP_PROTO_ICMP:
snmp_inc_ipindelivers();
icmp_input(p, inp);
break;
#endif /* LWIP_ICMP */
#if LWIP_IGMP
case IP_PROTO_IGMP:
igmp_input(p,inp,&(iphdr->dest));
break;
#endif /* LWIP_IGMP */
default:
#if LWIP_ICMP
/* send ICMP destination protocol unreachable unless is was a broadcast */
if (!ip_addr_isbroadcast(&(iphdr->dest), inp) &&
!ip_addr_ismulticast(&(iphdr->dest))) {
p->payload = iphdr;
icmp_dest_unreach(p, ICMP_DUR_PROTO);
}
#endif /* LWIP_ICMP */
pbuf_free(p);
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
IP_STATS_INC(ip.proterr);
IP_STATS_INC(ip.drop);
snmp_inc_ipinunknownprotos();
}
}
current_netif = NULL;
current_header = NULL;
return ERR_OK;
}
/**
* Sends an IP packet on a network interface. This function constructs
* the IP header and calculates the IP header checksum. If the source
* IP address is NULL, the IP address of the outgoing network
* interface is filled in as source address.
* If the destination IP address is IP_HDRINCL, p is assumed to already
* include an IP header and p->payload points to it instead of the data.
*
* @param p the packet to send (p->payload points to the data, e.g. next
protocol header; if dest == IP_HDRINCL, p already includes an IP
header and p->payload points to that IP header)
* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
* IP address of the netif used to send is used as source address)
* @param dest the destination IP address to send the packet to
* @param ttl the TTL value to be set in the IP header
* @param tos the TOS value to be set in the IP header
* @param proto the PROTOCOL to be set in the IP header
* @param netif the netif on which to send this packet
* @return ERR_OK if the packet was sent OK
* ERR_BUF if p doesn't have enough space for IP/LINK headers
* returns errors returned by netif->output
*
* @note ip_id: RFC791 "some host may be able to simply use
* unique identifiers independent of destination"
*/
err_t
ip_output_if(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
u8_t ttl, u8_t tos,
u8_t proto, struct netif *netif)
{
#if IP_OPTIONS_SEND
return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
}
/**
* Same as ip_output_if() but with the possibility to include IP options:
*
* @ param ip_options pointer to the IP options, copied into the IP header
* @ param optlen length of ip_options
*/
err_t ip_output_if_opt(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
u16_t optlen)
{
#endif /* IP_OPTIONS_SEND */
struct ip_hdr *iphdr;
static u16_t ip_id = 0;
snmp_inc_ipoutrequests();
/* Should the IP header be generated or is it already included in p? */
if (dest != IP_HDRINCL) {
u16_t ip_hlen = IP_HLEN;
#if IP_OPTIONS_SEND
u16_t optlen_aligned = 0;
if (optlen != 0) {
/* round up to a multiple of 4 */
optlen_aligned = ((optlen + 3) & ~3);
ip_hlen += optlen_aligned;
/* First write in the IP options */
if (pbuf_header(p, optlen_aligned)) {
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
IP_STATS_INC(ip.err);
snmp_inc_ipoutdiscards();
return ERR_BUF;
}
MEMCPY(p->payload, ip_options, optlen);
if (optlen < optlen_aligned) {
/* zero the remaining bytes */
memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
}
}
#endif /* IP_OPTIONS_SEND */
/* generate IP header */
if (pbuf_header(p, IP_HLEN)) {
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_output: not enough room for IP header in pbuf\n"));
IP_STATS_INC(ip.err);
snmp_inc_ipoutdiscards();
return ERR_BUF;
}
iphdr = p->payload;
LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
(p->len >= sizeof(struct ip_hdr)));
IPH_TTL_SET(iphdr, ttl);
IPH_PROTO_SET(iphdr, proto);
ip_addr_set(&(iphdr->dest), dest);
IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
IPH_LEN_SET(iphdr, htons(p->tot_len));
IPH_OFFSET_SET(iphdr, 0);
IPH_ID_SET(iphdr, htons(ip_id));
++ip_id;
if (ip_addr_isany(src)) {
ip_addr_set(&(iphdr->src), &(netif->ip_addr));
} else {
ip_addr_set(&(iphdr->src), src);
}
IPH_CHKSUM_SET(iphdr, 0);
#if CHECKSUM_GEN_IP
IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
#endif
} else {
/* IP header already included in p */
iphdr = p->payload;
dest = &(iphdr->dest);
}
IP_STATS_INC(ip.xmit);
LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
ip_debug_print(p);
#if ENABLE_LOOPBACK
if (ip_addr_cmp(dest, &netif->ip_addr)) {
/* Packet to self, enqueue it for loopback */
LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
return netif_loop_output(netif, p, dest);
}
#endif /* ENABLE_LOOPBACK */
#if IP_FRAG
/* don't fragment if interface has mtu set to 0 [loopif] */
if (netif->mtu && (p->tot_len > netif->mtu)) {
return ip_frag(p,netif,dest);
}
#endif
LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
return netif->output(netif, p, dest);
}
/**
* Simple interface to ip_output_if. It finds the outgoing network
* interface and calls upon ip_output_if to do the actual work.
*
* @param p the packet to send (p->payload points to the data, e.g. next
protocol header; if dest == IP_HDRINCL, p already includes an IP
header and p->payload points to that IP header)
* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
* IP address of the netif used to send is used as source address)
* @param dest the destination IP address to send the packet to
* @param ttl the TTL value to be set in the IP header
* @param tos the TOS value to be set in the IP header
* @param proto the PROTOCOL to be set in the IP header
*
* @return ERR_RTE if no route is found
* see ip_output_if() for more return values
*/
err_t
ip_output(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
u8_t ttl, u8_t tos, u8_t proto)
{
struct netif *netif;
if ((netif = ip_route(dest)) == NULL) {
LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to 0x%"X32_F"\n", dest->addr));
IP_STATS_INC(ip.rterr);
return ERR_RTE;
}
return ip_output_if(p, src, dest, ttl, tos, proto, netif);
}
#if LWIP_NETIF_HWADDRHINT
/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
* before calling ip_output_if.
*
* @param p the packet to send (p->payload points to the data, e.g. next
protocol header; if dest == IP_HDRINCL, p already includes an IP
header and p->payload points to that IP header)
* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
* IP address of the netif used to send is used as source address)
* @param dest the destination IP address to send the packet to
* @param ttl the TTL value to be set in the IP header
* @param tos the TOS value to be set in the IP header
* @param proto the PROTOCOL to be set in the IP header
* @param addr_hint address hint pointer set to netif->addr_hint before
* calling ip_output_if()
*
* @return ERR_RTE if no route is found
* see ip_output_if() for more return values
*/
err_t
ip_output_hinted(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
{
struct netif *netif;
err_t err;
if ((netif = ip_route(dest)) == NULL) {
LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to 0x%"X32_F"\n", dest->addr));
IP_STATS_INC(ip.rterr);
return ERR_RTE;
}
netif->addr_hint = addr_hint;
err = ip_output_if(p, src, dest, ttl, tos, proto, netif);
netif->addr_hint = NULL;
return err;
}
#endif /* LWIP_NETIF_HWADDRHINT*/
#if IP_DEBUG
/* Print an IP header by using LWIP_DEBUGF
* @param p an IP packet, p->payload pointing to the IP header
*/
void
ip_debug_print(struct pbuf *p)
{
struct ip_hdr *iphdr = p->payload;
u8_t *payload;
payload = (u8_t *)iphdr + IP_HLEN;
LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" | 0x%02"X16_F" | %5"U16_F" | (v, hl, tos, len)\n",
IPH_V(iphdr),
IPH_HL(iphdr),
IPH_TOS(iphdr),
ntohs(IPH_LEN(iphdr))));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" |%"U16_F"%"U16_F"%"U16_F"| %4"U16_F" | (id, flags, offset)\n",
ntohs(IPH_ID(iphdr)),
ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | 0x%04"X16_F" | (ttl, proto, chksum)\n",
IPH_TTL(iphdr),
IPH_PROTO(iphdr),
ntohs(IPH_CHKSUM(iphdr))));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (src)\n",
ip4_addr1(&iphdr->src),
ip4_addr2(&iphdr->src),
ip4_addr3(&iphdr->src),
ip4_addr4(&iphdr->src)));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (dest)\n",
ip4_addr1(&iphdr->dest),
ip4_addr2(&iphdr->dest),
ip4_addr3(&iphdr->dest),
ip4_addr4(&iphdr->dest)));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
}
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");
}
err_t
ip_input(struct pbuf *p, struct netif *inp) {
struct ip_hdr *iphdr;
struct netif *netif;
u16_t iphdrlen;
IP_STATS_INC(ip.recv);
snmp_inc_ipinreceives();
/* identify the IP header */
iphdr = p->payload;
if (IPH_V(iphdr) != 4) {
LWIP_DEBUGF(IP_DEBUG | 1, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
ip_debug_print(p);
pbuf_free(p);
IP_STATS_INC(ip.err);
IP_STATS_INC(ip.drop);
snmp_inc_ipinhdrerrors();
return ERR_OK;
}
/* obtain IP header length in number of 32-bit words */
iphdrlen = IPH_HL(iphdr);
/* calculate IP header length in bytes */
iphdrlen *= 4;
/* header length exceeds first pbuf length? */
if (iphdrlen > p->len) {
LWIP_DEBUGF(IP_DEBUG | 2, ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet droppped.\n",
iphdrlen, p->len));
/* free (drop) packet pbufs */
pbuf_free(p);
IP_STATS_INC(ip.lenerr);
IP_STATS_INC(ip.drop);
snmp_inc_ipindiscards();
return ERR_OK;
}
/* verify checksum */
#if CHECKSUM_CHECK_IP
if (inet_chksum(iphdr, iphdrlen) != 0) {
LWIP_DEBUGF(IP_DEBUG | 2, ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdrlen)));
ip_debug_print(p);
pbuf_free(p);
IP_STATS_INC(ip.chkerr);
IP_STATS_INC(ip.drop);
snmp_inc_ipinhdrerrors();
return ERR_OK;
}
#endif
/* Trim pbuf. This should have been done at the netif layer,
* but we'll do it anyway just to be sure that its done. */
pbuf_realloc(p, ntohs(IPH_LEN(iphdr)));
/* match packet against an interface, i.e. is this packet for us? */
for (netif = netif_list; netif != NULL; netif = netif->next) {
LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%"X32_F" netif->ip_addr 0x%"X32_F" (0x%"X32_F", 0x%"X32_F", 0x%"X32_F")\n",
iphdr->dest.addr, netif->ip_addr.addr,
iphdr->dest.addr & netif->netmask.addr,
netif->ip_addr.addr & netif->netmask.addr,
iphdr->dest.addr & ~(netif->netmask.addr)));
/* interface is up and configured? */
if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr))))
{
/* unicast to this interface address? */
if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr)) ||
/* or broadcast on this interface network address? */
ip_addr_isbroadcast(&(iphdr->dest), netif)) {
LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
netif->name[0], netif->name[1]));
/* break out of for loop */
break;
}
}
}
#if LWIP_DHCP
/* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
* using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
* According to RFC 1542 section 3.1.1, referred by RFC 2131).
*/
if (netif == NULL) {
/* remote port is DHCP server? */
if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
LWIP_DEBUGF(IP_DEBUG | DBG_TRACE | 1, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdrlen))->dest)));
if (ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdrlen))->dest) == DHCP_CLIENT_PORT) {
LWIP_DEBUGF(IP_DEBUG | DBG_TRACE | 1, ("ip_input: DHCP packet accepted.\n"));
netif = inp;
}
}
}
#endif /* LWIP_DHCP */
/* packet not for us? */
if (netif == NULL) {
/* packet not for us, route or discard */
LWIP_DEBUGF(IP_DEBUG | DBG_TRACE | 1, ("ip_input: packet not for us.\n"));
#if IP_FORWARD
/* non-broadcast packet? */
if (!ip_addr_isbroadcast(&(iphdr->dest), inp)) {
/* try to forward IP packet on (other) interfaces */
ip_forward(p, iphdr, inp);
}
else
#endif /* IP_FORWARD */
{
snmp_inc_ipinaddrerrors();
snmp_inc_ipindiscards();
}
pbuf_free(p);
return ERR_OK;
}
/* packet consists of multiple fragments? */
if ((IPH_OFFSET(iphdr) & htons(IP_OFFMASK | IP_MF)) != 0) {
#if IP_REASSEMBLY /* packet fragment reassembly code present? */
LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04"X16_F" tot_len=%"U16_F" len=%"U16_F" MF=%"U16_F" offset=%"U16_F"), calling ip_reass()\n",
ntohs(IPH_ID(iphdr)), p->tot_len, ntohs(IPH_LEN(iphdr)), !!(IPH_OFFSET(iphdr) & htons(IP_MF)), (ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)*8));
/* reassemble the packet*/
p = ip_reass(p);
/* packet not fully reassembled yet? */
if (p == NULL) {
return ERR_OK;
}
iphdr = p->payload;
#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
pbuf_free(p);
LWIP_DEBUGF(IP_DEBUG | 2, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
ntohs(IPH_OFFSET(iphdr))));
IP_STATS_INC(ip.opterr);
IP_STATS_INC(ip.drop);
/* unsupported protocol feature */
snmp_inc_ipinunknownprotos();
return ERR_OK;
#endif /* IP_REASSEMBLY */
}
#if IP_OPTIONS == 0 /* no support for IP options in the IP header? */
if (iphdrlen > IP_HLEN) {
LWIP_DEBUGF(IP_DEBUG | 2, ("IP packet dropped since there were IP options (while IP_OPTIONS == 0).\n"));
pbuf_free(p);
IP_STATS_INC(ip.opterr);
IP_STATS_INC(ip.drop);
/* unsupported protocol feature */
snmp_inc_ipinunknownprotos();
return ERR_OK;
}
#endif /* IP_OPTIONS == 0 */
/* send to upper layers */
LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
ip_debug_print(p);
LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
#if LWIP_RAW
/* raw input did not eat the packet? */
if (raw_input(p, inp) == 0) {
#endif /* LWIP_RAW */
switch (IPH_PROTO(iphdr)) {
#if LWIP_UDP
case IP_PROTO_UDP:
case IP_PROTO_UDPLITE:
snmp_inc_ipindelivers();
udp_input(p, inp);
break;
#endif /* LWIP_UDP */
#if LWIP_TCP
case IP_PROTO_TCP:
snmp_inc_ipindelivers();
tcp_input(p, inp);
break;
#endif /* LWIP_TCP */
case IP_PROTO_ICMP:
snmp_inc_ipindelivers();
icmp_input(p, inp);
break;
default:
/* send ICMP destination protocol unreachable unless is was a broadcast */
if (!ip_addr_isbroadcast(&(iphdr->dest), inp) &&
!ip_addr_ismulticast(&(iphdr->dest))) {
p->payload = iphdr;
icmp_dest_unreach(p, ICMP_DUR_PROTO);
}
pbuf_free(p);
LWIP_DEBUGF(IP_DEBUG | 2, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
IP_STATS_INC(ip.proterr);
IP_STATS_INC(ip.drop);
snmp_inc_ipinunknownprotos();
}
#if LWIP_RAW
} /* LWIP_RAW */
#endif
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
void
udp_input(struct pbuf *p, struct netif *inp)
{
struct udp_hdr *udphdr;
struct udp_pcb *pcb;
struct ip_hdr *iphdr;
uint16_t src, dest;
#ifdef UDP_STATS
++stats.udp.recv;
#endif /* UDP_STATS */
iphdr = (struct ip_hdr *)p->payload;
pbuf_header(p, -(UDP_HLEN + IPH_HL(iphdr) * 4));
udphdr = (struct udp_hdr *)((uint8_t *)p->payload - UDP_HLEN);
DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %d\n", p->tot_len));
src = NTOHS(udphdr->src);
dest = NTOHS(udphdr->dest);
#if UDP_DEBUG
udp_debug_print(udphdr);
#endif /* UDP_DEBUG */
/* Demultiplex packet. First, go for a perfect match. */
for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
DEBUGF(UDP_DEBUG, ("udp_input: pcb local port %d (dgram %d)\n",
pcb->local_port, ntohs(udphdr->dest)));
if(pcb->remote_port == src &&
pcb->local_port == dest &&
(ip_addr_isany(&pcb->remote_ip) ||
ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) &&
(ip_addr_isany(&pcb->local_ip) ||
ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) {
break;
}
}
if(pcb == NULL) {
for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
DEBUGF(UDP_DEBUG, ("udp_input: pcb local port %d (dgram %d)\n",
pcb->local_port, dest));
if(pcb->local_port == dest &&
(ip_addr_isany(&pcb->remote_ip) ||
ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) &&
(ip_addr_isany(&pcb->local_ip) ||
ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) {
break;
}
}
}
/* 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)) {*/
if(pcb != NULL) {
DEBUGF(UDP_DEBUG, ("udp_input: calculating checksum\n"));
pbuf_header(p, UDP_HLEN);
#ifdef IPv6
if(iphdr->nexthdr == IP_PROTO_UDPLITE) {
#else
if(IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) {
#endif /* IPv4 */
/* Do the UDP Lite checksum */
if(inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src),
(struct ip_addr *)&(iphdr->dest),
IP_PROTO_UDPLITE, ntohs(udphdr->len)) != 0) {
DEBUGF(UDP_DEBUG, ("udp_input: UDP Lite datagram discarded due to failing checksum\n"));
#ifdef UDP_STATS
++stats.udp.chkerr;
++stats.udp.drop;
#endif /* UDP_STATS */
pbuf_free(p);
goto end;
}
} else {
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) {
DEBUGF(UDP_DEBUG, ("udp_input: UDP datagram discarded due to failing checksum\n"));
#ifdef UDP_STATS
++stats.udp.chkerr;
++stats.udp.drop;
#endif /* UDP_STATS */
pbuf_free(p);
goto end;
}
}
}
pbuf_header(p, -UDP_HLEN);
if(pcb != NULL) {
pcb->recv(pcb->recv_arg, pcb, p, &(iphdr->src), src);
} else {
DEBUGF(UDP_DEBUG, ("udp_input: not for us.\n"));
/* No match was found, send ICMP destination port unreachable unless
destination address was broadcast/multicast. */
if(!ip_addr_isbroadcast(&iphdr->dest, &inp->netmask) &&
!ip_addr_ismulticast(&iphdr->dest)) {
/* deconvert from host to network byte order */
udphdr->src = htons(udphdr->src);
udphdr->dest = htons(udphdr->dest);
/* adjust pbuf pointer */
p->payload = iphdr;
icmp_dest_unreach(p, ICMP_DUR_PORT);
}
#ifdef UDP_STATS
++stats.udp.proterr;
++stats.udp.drop;
#endif /* UDP_STATS */
pbuf_free(p);
}
} else {
pbuf_free(p);
}
end:
while(0); /* hack to remove compiler warning */
}
/*-----------------------------------------------------------------------------------*/
err_t
udp_send(struct udp_pcb *pcb, struct pbuf *p)
{
struct udp_hdr *udphdr;
struct ip_addr *src_ip;
err_t err;
struct pbuf *q;
if(pbuf_header(p, UDP_HLEN)) {
q = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM);
if(q == NULL) {
return ERR_MEM;
}
pbuf_chain(q, p);
p = q;
}
udphdr = (struct udp_hdr *)p->payload;
udphdr->src = htons(pcb->local_port);
udphdr->dest = htons(pcb->remote_port);
udphdr->chksum = 0x0000;
src_ip = &(pcb->local_ip);
DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %d\n", p->tot_len));
if(pcb->flags & UDP_FLAGS_UDPLITE) {
udphdr->len = htons(pcb->chksum_len);
/* calculate checksum */
udphdr->chksum = inet_chksum_pseudo(p, src_ip, &(pcb->remote_ip),
IP_PROTO_UDP, pcb->chksum_len);
if(udphdr->chksum == 0x0000) {
udphdr->chksum = 0xffff;
}
err = sr_lwip_output(p, &pcb->local_ip, &pcb->remote_ip, IP_PROTO_UDPLITE);
} else {
udphdr->len = htons(p->tot_len);
/* calculate checksum */
if((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) {
udphdr->chksum = inet_chksum_pseudo(p, src_ip, &pcb->remote_ip,
IP_PROTO_UDP, p->tot_len);
if(udphdr->chksum == 0x0000) {
udphdr->chksum = 0xffff;
}
}
err = sr_lwip_output(p,&pcb->local_ip, &pcb->remote_ip, IP_PROTO_UDP);
}
#ifdef UDP_STATS
++stats.udp.xmit;
#endif /* UDP_STATS */
return err;
}
/*-----------------------------------------------------------------------------------*/
err_t
udp_bind(struct udp_pcb *pcb, struct ip_addr *ipaddr, uint16_t port)
{
struct udp_pcb *ipcb;
ip_addr_set(&pcb->local_ip, ipaddr);
pcb->local_port = port;
/* Insert UDP PCB into the list of active UDP PCBs. */
for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
if(pcb == ipcb) {
/* Already on the list, just return. */
return ERR_OK;
}
}
/* We need to place the PCB on the list. */
pcb->next = udp_pcbs;
udp_pcbs = pcb;
DEBUGF(UDP_DEBUG, ("udp_bind: bound to port %d\n", port));
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
err_t
udp_connect(struct udp_pcb *pcb, struct ip_addr *ipaddr, uint16_t port)
{
struct udp_pcb *ipcb;
ip_addr_set(&pcb->remote_ip, ipaddr);
pcb->remote_port = port;
/* Insert UDP PCB into the list of active UDP PCBs. */
for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
if(pcb == ipcb) {
/* Already on the list, just return. */
return ERR_OK;
}
}
/* We need to place the PCB on the list. */
pcb->next = udp_pcbs;
udp_pcbs = pcb;
return ERR_OK;
}
/*-----------------------------------------------------------------------------------*/
void
udp_recv(struct udp_pcb *pcb,
void (* recv)(void *arg, struct udp_pcb *upcb, struct pbuf *p,
struct ip_addr *addr, uint16_t port),
void *recv_arg)
{
pcb->recv = recv;
pcb->recv_arg = recv_arg;
}
/**
* 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);
}
/**
* This function is called by the network interface device driver when
* an IP packet is received. The function does the basic checks of the
* IP header such as packet size being at least larger than the header
* size etc. If the packet was not destined for us, the packet is
* forwarded (using ip_forward). The IP checksum is always checked.
*
* Finally, the packet is sent to the upper layer protocol input function.
*
* @param p the received IP packet (p->payload points to IP header)
* @param inp the netif on which this packet was received
* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
* processed, but currently always returns ERR_OK)
*/
uint8 ip_input(PBUF *p, NETIF *inp)
{
IP_HDR *iphdr;
NETIF *netif;
uint16 iphdr_hlen;
uint16 iphdr_len;
/* identify the IP header */
iphdr = p->payload;
if (IPH_V(iphdr) != 4)
{
pbuf_free(p);//this packet is not ipv4
return ERR_OK;
}
/* obtain IP header length in number of 32-bit words */
iphdr_hlen = IPH_HL(iphdr);
/* calculate IP header length in bytes */
iphdr_hlen *= 4;
/* obtain ip pocket total length in bytes */
iphdr_len = ntohs(IPH_LEN(iphdr));
/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
if ((iphdr_hlen > p->len) || (iphdr_len > p->len))
{
/* free (drop) packet pbufs */
pbuf_free(p);
return ERR_OK;
}
if (inet_chksum(iphdr, iphdr_hlen) != 0)
{
pbuf_free(p);//ip header checksum error!
return ERR_OK;
}
netif = inp;
/* interface is up and configured? */
if (ip_addr_isany(&(netif->ip_addr)))
{
netif = NULL;
}
else
{
/* unicast to this interface address? */
if (!ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr)))
{
netif = NULL;
}
}
/* packet consists of multiple fragments? */
if ((IPH_OFFSET(iphdr) & htons(IP_OFFMASK | IP_MF)) != 0)
{
printf("received splited IP packet!! \n");
pbuf_free(p);
return ERR_OK;
}
if (iphdr_hlen > IP_HLEN)
{
pbuf_free(p);
return ERR_OK;
}
switch (IPH_PROTO(iphdr))
{
case IP_PROTO_TCP://(6)
//printf("get a tcp packet\n");
tcp_input(p, inp);
break;
case IP_PROTO_UDP://(17)
printf("UDP\n");
udp_input(p, inp);
break;
case IP_PROTO_ICMP://(1)
printf("gICMP\n");
icmp_input(p, inp);
break;
default:
/* send ICMP destination protocol unreachable unless is was a broadcast */
printf("gerr\n");
if (!ip_addr_isbroadcast(&(iphdr->dest), inp) && !ip_addr_ismulticast(&(iphdr->dest)))
{
p->payload = iphdr;
icmp_dest_unreach(p, ICMP_DUR_PROTO);
}
pbuf_free(p);
}
return ERR_OK;
}
err_t udp_input(struct pbuf *p, struct netif *inp) {
struct udp_hdr *udphdr;
struct udp_pcb *pcb;
struct ip_hdr *iphdr;
unsigned short src, dest;
stats.udp.recv++;
iphdr = p->payload;
if (pbuf_header(p, -(IPH_HL(iphdr) * 4)) < 0 || p->tot_len < sizeof(struct udp_hdr)) {
kprintf(KERN_WARNING "udp_input: short packet (%u bytes) discarded\n", p->tot_len);
stats.udp.lenerr++;
stats.udp.drop++;
return -EPROTO;
}
udphdr = p->payload;
//udp_debug_print(udphdr);
#ifdef CHECK_UDP_CHECKSUM
// Check checksum
if ((inp->flags & NETIF_UDP_RX_CHECKSUM_OFFLOAD) == 0) {
if (udphdr->chksum != 0) {
if (inet_chksum_pseudo(p, &iphdr->src, &iphdr->dest, IP_PROTO_UDP, p->tot_len) != 0) {
kprintf(KERN_WARNING "udp_input: UDP datagram discarded due to failing checksum\n");
stats.udp.chkerr++;
stats.udp.drop++;
return -ECHKSUM;
}
}
}
#endif
src = NTOHS(udphdr->src);
dest = NTOHS(udphdr->dest);
// Demultiplex packet. First, go for a perfect match
for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
if (pcb->remote_port == src && pcb->local_port == dest &&
(ip_addr_isany(&pcb->remote_ip) || ip_addr_cmp(&pcb->remote_ip, &iphdr->src)) &&
(ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&pcb->local_ip, &iphdr->dest))) {
break;
}
}
if (pcb == NULL) {
// No fully matching pcb found, look for an unconnected pcb
for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
if (!(pcb->flags & UDP_FLAGS_CONNECTED) &&
pcb->local_port == dest &&
(ip_addr_isany(&pcb->remote_ip) || ip_addr_cmp(&pcb->remote_ip, &iphdr->src)) &&
(ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&pcb->local_ip, &iphdr->dest))) {
break;
}
}
}
if (pcb == NULL) {
// No match was found, send ICMP destination port unreachable unless
// destination address was broadcast/multicast.
if (!ip_addr_isbroadcast(&iphdr->dest, &inp->netmask) && !ip_addr_ismulticast(&iphdr->dest)) {
// Adjust pbuf pointer
p->payload = iphdr;
icmp_dest_unreach(p, ICMP_DUR_PORT);
}
++stats.udp.proterr;
++stats.udp.drop;
return -EHOSTUNREACH;
}
pbuf_header(p, -UDP_HLEN);
return pcb->recv(pcb->recv_arg, pcb, p, &iphdr->src, src);
}
/*-----------------------------------------------------------------------------------*/
err_t
ip_input(struct pbuf *p, struct netif *inp) {
static struct ip_hdr *iphdr;
static struct netif *netif;
static u8_t hl;
#ifdef IP_STATS
++stats.ip.recv;
#endif /* IP_STATS */
/* identify the IP header */
iphdr = p->payload;
if(IPH_V(iphdr) != 4) {
DEBUGF(IP_DEBUG, ("IP packet dropped due to bad version number %d\n", IPH_V(iphdr)));
#if IP_DEBUG
ip_debug_print(p);
#endif /* IP_DEBUG */
pbuf_free(p);
#ifdef IP_STATS
++stats.ip.err;
++stats.ip.drop;
#endif /* IP_STATS */
return ERR_OK;
}
hl = IPH_HL(iphdr);
if(hl * 4 > p->len) {
DEBUGF(IP_DEBUG, ("IP packet dropped due to too short packet %d\n", p->len));
pbuf_free(p);
#ifdef IP_STATS
++stats.ip.lenerr;
++stats.ip.drop;
#endif /* IP_STATS */
return ERR_OK;
}
/* verify checksum */
if(inet_chksum(iphdr, hl * 4) != 0) {
DEBUGF(IP_DEBUG, ("IP packet dropped due to failing checksum 0x%x\n", inet_chksum(iphdr, hl * 4)));
#if IP_DEBUG
ip_debug_print(p);
#endif /* IP_DEBUG */
pbuf_free(p);
#ifdef IP_STATS
++stats.ip.chkerr;
++stats.ip.drop;
#endif /* IP_STATS */
return ERR_OK;
}
/* Trim pbuf. This should have been done at the netif layer,
but we'll do it anyway just to be sure that its done. */
pbuf_realloc(p, ntohs(IPH_LEN(iphdr)));
/* is this packet for us? */
for(netif = netif_list; netif != NULL; netif = netif->next) {
DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%lx netif->ip_addr 0x%lx (0x%lx, 0x%lx, 0x%lx)\n",
iphdr->dest.addr, netif->ip_addr.addr,
iphdr->dest.addr & netif->netmask.addr,
netif->ip_addr.addr & netif->netmask.addr,
iphdr->dest.addr & ~(netif->netmask.addr)));
if(ip_addr_isany(&(netif->ip_addr)) ||
ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr)) ||
(ip_addr_isbroadcast(&(iphdr->dest), &(netif->netmask)) &&
ip_addr_maskcmp(&(iphdr->dest), &(netif->ip_addr), &(netif->netmask))) ||
ip_addr_cmp(&(iphdr->dest), IP_ADDR_BROADCAST)) {
break;
}
}
#if LWIP_DHCP
/* If a DHCP packet has arrived on the interface, we pass it up the
stack regardless of destination IP address. The reason is that
DHCP replies are sent to the IP adress that will be given to this
node (as recommended by RFC 1542 section 3.1.1, referred by RFC
2131). */
if(IPH_PROTO(iphdr) == IP_PROTO_UDP &&
((struct udp_hdr *)((u8_t *)iphdr + IPH_HL(iphdr) * 4/sizeof(u8_t)))->src ==
DHCP_SERVER_PORT) {
netif = inp;
}
#endif /* LWIP_DHCP */
if(netif == NULL) {
/* packet not for us, route or discard */
DEBUGF(IP_DEBUG, ("ip_input: packet not for us.\n"));
#if IP_FORWARD
if(!ip_addr_isbroadcast(&(iphdr->dest), &(inp->netmask))) {
ip_forward(p, iphdr, inp);
}
#endif /* IP_FORWARD */
pbuf_free(p);
return ERR_OK;
}
#if IP_REASSEMBLY
if((IPH_OFFSET(iphdr) & htons(IP_OFFMASK | IP_MF)) != 0) {
p = ip_reass(p);
if(p == NULL) {
return ERR_OK;
}
iphdr = p->payload;
}
#else /* IP_REASSEMBLY */
if((IPH_OFFSET(iphdr) & htons(IP_OFFMASK | IP_MF)) != 0) {
pbuf_free(p);
DEBUGF(IP_DEBUG, ("IP packet dropped since it was fragmented (0x%x).\n",
ntohs(IPH_OFFSET(iphdr))));
#ifdef IP_STATS
++stats.ip.opterr;
++stats.ip.drop;
#endif /* IP_STATS */
return ERR_OK;
}
#endif /* IP_REASSEMBLY */
#if IP_OPTIONS == 0
if(hl * 4 > IP_HLEN) {
DEBUGF(IP_DEBUG, ("IP packet dropped since there were IP options.\n"));
pbuf_free(p);
#ifdef IP_STATS
++stats.ip.opterr;
++stats.ip.drop;
#endif /* IP_STATS */
return ERR_OK;
}
#endif /* IP_OPTIONS == 0 */
/* send to upper layers */
#if IP_DEBUG
DEBUGF(IP_DEBUG, ("ip_input: \n"));
ip_debug_print(p);
DEBUGF(IP_DEBUG, ("ip_input: p->len %d p->tot_len %d\n", p->len, p->tot_len));
#endif /* IP_DEBUG */
switch(IPH_PROTO(iphdr)) {
#if LWIP_UDP > 0
case IP_PROTO_UDP:
udp_input(p, inp);
break;
#endif /* LWIP_UDP */
#if LWIP_TCP > 0
case IP_PROTO_TCP:
tcp_input(p, inp);
break;
#endif /* LWIP_TCP */
case IP_PROTO_ICMP:
icmp_input(p, inp);
break;
default:
/* send ICMP destination protocol unreachable unless is was a broadcast */
if(!ip_addr_isbroadcast(&(iphdr->dest), &(inp->netmask)) &&
!ip_addr_ismulticast(&(iphdr->dest))) {
p->payload = iphdr;
icmp_dest_unreach(p, ICMP_DUR_PROTO);
}
pbuf_free(p);
DEBUGF(IP_DEBUG, ("Unsupported transportation protocol %d\n", IPH_PROTO(iphdr)));
#ifdef IP_STATS
++stats.ip.proterr;
++stats.ip.drop;
#endif /* IP_STATS */
}
return ERR_OK;
}
