/** | |
* @file | |
* User Datagram Protocol module | |
* | |
*/ | |
/* | |
* Copyright (c) 2001-2004 Swedish Institute of Computer Science. | |
* All rights reserved. | |
* | |
* Redistribution and use in source and binary forms, with or without modification, | |
* are permitted provided that the following conditions are met: | |
* | |
* 1. Redistributions of source code must retain the above copyright notice, | |
* this list of conditions and the following disclaimer. | |
* 2. Redistributions in binary form must reproduce the above copyright notice, | |
* this list of conditions and the following disclaimer in the documentation | |
* and/or other materials provided with the distribution. | |
* 3. The name of the author may not be used to endorse or promote products | |
* derived from this software without specific prior written permission. | |
* | |
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED | |
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT | |
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, | |
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT | |
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY | |
* OF SUCH DAMAGE. | |
* | |
* This file is part of the lwIP TCP/IP stack. | |
* | |
* Author: Adam Dunkels <adam@sics.se> | |
* | |
*/ | |
/* udp.c | |
* | |
* The code for the User Datagram Protocol UDP & UDPLite (RFC 3828). | |
* | |
*/ | |
/* @todo Check the use of '(struct udp_pcb).chksum_len_rx'! | |
*/ | |
#include "lwip/opt.h" | |
#if LWIP_UDP /* don't build if not configured for use in lwipopts.h */ | |
#include "lwip/udp.h" | |
#include "lwip/def.h" | |
#include "lwip/memp.h" | |
#include "lwip/inet.h" | |
#include "lwip/inet_chksum.h" | |
#include "lwip/ip_addr.h" | |
#include "lwip/netif.h" | |
#include "lwip/icmp.h" | |
#include "lwip/stats.h" | |
#include "lwip/snmp.h" | |
#include "arch/perf.h" | |
#include "lwip/dhcp.h" | |
#include <string.h> | |
/* The list of UDP PCBs */ | |
/* exported in udp.h (was static) */ | |
struct udp_pcb *udp_pcbs; | |
/** | |
* 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; | |
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; | |
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) && | |
(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 */ | |
ip_addr_isbroadcast(&(iphdr->dest), inp))) { | |
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; | |
} | |
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 | 2, | |
("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 | 2, | |
("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 (!ip_addr_isbroadcast(&iphdr->dest, inp) && | |
!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"); | |
} | |
/** | |
* Send data using UDP. | |
* | |
* @param pcb UDP PCB used to send the data. | |
* @param p chain of pbuf's to be sent. | |
* | |
* The datagram will be sent to the current remote_ip & remote_port | |
* stored in pcb. If the pcb is not bound to a port, it will | |
* automatically be bound to a random port. | |
* | |
* @return lwIP error code. | |
* - ERR_OK. Successful. No error occured. | |
* - ERR_MEM. Out of memory. | |
* - ERR_RTE. Could not find route to destination address. | |
* - More errors could be returned by lower protocol layers. | |
* | |
* @see udp_disconnect() udp_sendto() | |
*/ | |
err_t | |
udp_send(struct udp_pcb *pcb, struct pbuf *p) | |
{ | |
/* send to the packet using remote ip and port stored in the pcb */ | |
return udp_sendto(pcb, p, &pcb->remote_ip, pcb->remote_port); | |
} | |
/** | |
* Send data to a specified address using UDP. | |
* | |
* @param pcb UDP PCB used to send the data. | |
* @param p chain of pbuf's to be sent. | |
* @param dst_ip Destination IP address. | |
* @param dst_port Destination UDP port. | |
* | |
* dst_ip & dst_port are expected to be in the same byte order as in the pcb. | |
* | |
* If the PCB already has a remote address association, it will | |
* be restored after the data is sent. | |
* | |
* @return lwIP error code (@see udp_send for possible error codes) | |
* | |
* @see udp_disconnect() udp_send() | |
*/ | |
err_t | |
udp_sendto(struct udp_pcb *pcb, struct pbuf *p, | |
struct ip_addr *dst_ip, u16_t dst_port) | |
{ | |
struct netif *netif; | |
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | 3, ("udp_send\n")); | |
/* find the outgoing network interface for this packet */ | |
#if LWIP_IGMP | |
netif = ip_route((ip_addr_ismulticast(dst_ip))?(&(pcb->multicast_ip)):(dst_ip)); | |
#else | |
netif = ip_route(dst_ip); | |
#endif /* LWIP_IGMP */ | |
/* no outgoing network interface could be found? */ | |
if (netif == NULL) { | |
LWIP_DEBUGF(UDP_DEBUG | 1, ("udp_send: No route to 0x%"X32_F"\n", dst_ip->addr)); | |
UDP_STATS_INC(udp.rterr); | |
return ERR_RTE; | |
} | |
return udp_sendto_if(pcb, p, dst_ip, dst_port, netif); | |
} | |
/** | |
* Send data to a specified address using UDP. | |
* The netif used for sending can be specified. | |
* | |
* This function exists mainly for DHCP, to be able to send UDP packets | |
* on a netif that is still down. | |
* | |
* @param pcb UDP PCB used to send the data. | |
* @param p chain of pbuf's to be sent. | |
* @param dst_ip Destination IP address. | |
* @param dst_port Destination UDP port. | |
* @param netif the netif used for sending. | |
* | |
* dst_ip & dst_port are expected to be in the same byte order as in the pcb. | |
* | |
* @return lwIP error code (@see udp_send for possible error codes) | |
* | |
* @see udp_disconnect() udp_send() | |
*/ | |
err_t | |
udp_sendto_if(struct udp_pcb *pcb, struct pbuf *p, | |
struct ip_addr *dst_ip, u16_t dst_port, struct netif *netif) | |
{ | |
struct udp_hdr *udphdr; | |
struct ip_addr *src_ip; | |
err_t err; | |
struct pbuf *q; /* q will be sent down the stack */ | |
/* if the PCB is not yet bound to a port, bind it here */ | |
if (pcb->local_port == 0) { | |
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | 2, ("udp_send: not yet bound to a port, binding now\n")); | |
err = udp_bind(pcb, &pcb->local_ip, pcb->local_port); | |
if (err != ERR_OK) { | |
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | 2, ("udp_send: forced port bind failed\n")); | |
return err; | |
} | |
} | |
/* not enough space to add an UDP header to first pbuf in given p chain? */ | |
if (pbuf_header(p, UDP_HLEN)) { | |
/* allocate header in a separate new pbuf */ | |
q = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM); | |
/* new header pbuf could not be allocated? */ | |
if (q == NULL) { | |
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | 2, ("udp_send: could not allocate header\n")); | |
return ERR_MEM; | |
} | |
/* chain header q in front of given pbuf p */ | |
pbuf_chain(q, p); | |
/* first pbuf q points to header pbuf */ | |
LWIP_DEBUGF(UDP_DEBUG, | |
("udp_send: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p)); | |
} else { | |
/* adding space for header within p succeeded */ | |
/* first pbuf q equals given pbuf */ | |
q = p; | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: added header in given pbuf %p\n", (void *)p)); | |
} | |
LWIP_ASSERT("check that first pbuf can hold struct udp_hdr", | |
(q->len >= sizeof(struct udp_hdr))); | |
/* q now represents the packet to be sent */ | |
udphdr = q->payload; | |
udphdr->src = htons(pcb->local_port); | |
udphdr->dest = htons(dst_port); | |
/* in UDP, 0 checksum means 'no checksum' */ | |
udphdr->chksum = 0x0000; | |
/* PCB local address is IP_ANY_ADDR? */ | |
if (ip_addr_isany(&pcb->local_ip)) { | |
/* use outgoing network interface IP address as source address */ | |
src_ip = &(netif->ip_addr); | |
} else { | |
/* check if UDP PCB local IP address is correct | |
* this could be an old address if netif->ip_addr has changed */ | |
if (!ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) { | |
/* local_ip doesn't match, drop the packet */ | |
if (q != p) { | |
/* free the header pbuf */ | |
pbuf_free(q); | |
q = NULL; | |
/* p is still referenced by the caller, and will live on */ | |
} | |
return ERR_VAL; | |
} | |
/* use UDP PCB local IP address as source address */ | |
src_ip = &(pcb->local_ip); | |
} | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %"U16_F"\n", q->tot_len)); | |
#if LWIP_UDPLITE | |
/* UDP Lite protocol? */ | |
if (pcb->flags & UDP_FLAGS_UDPLITE) { | |
u16_t chklen, chklen_hdr; | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE packet length %"U16_F"\n", q->tot_len)); | |
/* set UDP message length in UDP header */ | |
chklen_hdr = chklen = pcb->chksum_len_tx; | |
if ((chklen < sizeof(struct udp_hdr)) || (chklen > q->tot_len)) { | |
if (chklen != 0) { | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE pcb->chksum_len is illegal: %"U16_F"\n", chklen)); | |
} | |
/* For UDP-Lite, checksum length of 0 means checksum | |
over the complete packet. (See RFC 3828 chap. 3.1) | |
At least the UDP-Lite header must be covered by the | |
checksum, therefore, if chksum_len has an illegal | |
value, we generate the checksum over the complete | |
packet to be safe. */ | |
chklen_hdr = 0; | |
chklen = q->tot_len; | |
} | |
udphdr->len = htons(chklen_hdr); | |
/* calculate checksum */ | |
#if CHECKSUM_GEN_UDP | |
udphdr->chksum = inet_chksum_pseudo_partial(q, src_ip, dst_ip, | |
IP_PROTO_UDPLITE, q->tot_len, chklen); | |
/* chksum zero must become 0xffff, as zero means 'no checksum' */ | |
if (udphdr->chksum == 0x0000) | |
udphdr->chksum = 0xffff; | |
#endif /* CHECKSUM_CHECK_UDP */ | |
/* output to IP */ | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDPLITE,)\n")); | |
#if LWIP_NETIF_HWADDRHINT | |
netif->addr_hint = &(pcb->addr_hint); | |
#endif /* LWIP_NETIF_HWADDRHINT*/ | |
err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDPLITE, netif); | |
#if LWIP_NETIF_HWADDRHINT | |
netif->addr_hint = NULL; | |
#endif /* LWIP_NETIF_HWADDRHINT*/ | |
} else | |
#endif /* LWIP_UDPLITE */ | |
{ /* UDP */ | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP packet length %"U16_F"\n", q->tot_len)); | |
udphdr->len = htons(q->tot_len); | |
/* calculate checksum */ | |
#if CHECKSUM_GEN_UDP | |
if ((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) { | |
udphdr->chksum = inet_chksum_pseudo(q, src_ip, dst_ip, IP_PROTO_UDP, q->tot_len); | |
/* chksum zero must become 0xffff, as zero means 'no checksum' */ | |
if (udphdr->chksum == 0x0000) udphdr->chksum = 0xffff; | |
} | |
#endif /* CHECKSUM_CHECK_UDP */ | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum 0x%04"X16_F"\n", udphdr->chksum)); | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDP,)\n")); | |
/* output to IP */ | |
#if LWIP_NETIF_HWADDRHINT | |
netif->addr_hint = &(pcb->addr_hint); | |
#endif /* LWIP_NETIF_HWADDRHINT*/ | |
err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDP, netif); | |
#if LWIP_NETIF_HWADDRHINT | |
netif->addr_hint = NULL; | |
#endif /* LWIP_NETIF_HWADDRHINT*/ | |
} | |
/* TODO: must this be increased even if error occured? */ | |
snmp_inc_udpoutdatagrams(); | |
/* did we chain a separate header pbuf earlier? */ | |
if (q != p) { | |
/* free the header pbuf */ | |
pbuf_free(q); | |
q = NULL; | |
/* p is still referenced by the caller, and will live on */ | |
} | |
UDP_STATS_INC(udp.xmit); | |
return err; | |
} | |
/** | |
* Bind an UDP PCB. | |
* | |
* @param pcb UDP PCB to be bound with a local address ipaddr and port. | |
* @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to | |
* bind to all local interfaces. | |
* @param port local UDP port to bind with. Use 0 to automatically bind | |
* to a random port between UDP_LOCAL_PORT_RANGE_START and | |
* UDP_LOCAL_PORT_RANGE_END. | |
* | |
* ipaddr & port are expected to be in the same byte order as in the pcb. | |
* | |
* @return lwIP error code. | |
* - ERR_OK. Successful. No error occured. | |
* - ERR_USE. The specified ipaddr and port are already bound to by | |
* another UDP PCB. | |
* | |
* @see udp_disconnect() | |
*/ | |
err_t | |
udp_bind(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) | |
{ | |
struct udp_pcb *ipcb; | |
u8_t rebind; | |
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | 3, ("udp_bind(ipaddr = ")); | |
ip_addr_debug_print(UDP_DEBUG, ipaddr); | |
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | 3, (", port = %"U16_F")\n", port)); | |
rebind = 0; | |
/* Check for double bind and rebind of the same pcb */ | |
for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) { | |
/* is this UDP PCB already on active list? */ | |
if (pcb == ipcb) { | |
/* pcb may occur at most once in active list */ | |
LWIP_ASSERT("rebind == 0", rebind == 0); | |
/* pcb already in list, just rebind */ | |
rebind = 1; | |
} | |
/* this code does not allow upper layer to share a UDP port for | |
listening to broadcast or multicast traffic (See SO_REUSE_ADDR and | |
SO_REUSE_PORT under *BSD). TODO: See where it fits instead, OR | |
combine with implementation of UDP PCB flags. Leon Woestenberg. */ | |
#ifdef LWIP_UDP_TODO | |
/* port matches that of PCB in list? */ | |
else | |
if ((ipcb->local_port == port) && | |
/* IP address matches, or one is IP_ADDR_ANY? */ | |
(ip_addr_isany(&(ipcb->local_ip)) || | |
ip_addr_isany(ipaddr) || | |
ip_addr_cmp(&(ipcb->local_ip), ipaddr))) { | |
/* other PCB already binds to this local IP and port */ | |
LWIP_DEBUGF(UDP_DEBUG, | |
("udp_bind: local port %"U16_F" already bound by another pcb\n", port)); | |
return ERR_USE; | |
} | |
#endif | |
} | |
ip_addr_set(&pcb->local_ip, ipaddr); | |
/* no port specified? */ | |
if (port == 0) { | |
#ifndef UDP_LOCAL_PORT_RANGE_START | |
#define UDP_LOCAL_PORT_RANGE_START 4096 | |
#define UDP_LOCAL_PORT_RANGE_END 0x7fff | |
#endif | |
port = UDP_LOCAL_PORT_RANGE_START; | |
ipcb = udp_pcbs; | |
while ((ipcb != NULL) && (port != UDP_LOCAL_PORT_RANGE_END)) { | |
if (ipcb->local_port == port) { | |
/* port is already used by another udp_pcb */ | |
port++; | |
/* restart scanning all udp pcbs */ | |
ipcb = udp_pcbs; | |
} else | |
/* go on with next udp pcb */ | |
ipcb = ipcb->next; | |
} | |
if (ipcb != NULL) { | |
/* no more ports available in local range */ | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_bind: out of free UDP ports\n")); | |
return ERR_USE; | |
} | |
} | |
pcb->local_port = port; | |
snmp_insert_udpidx_tree(pcb); | |
/* pcb not active yet? */ | |
if (rebind == 0) { | |
/* place the PCB on the active list if not already there */ | |
pcb->next = udp_pcbs; | |
udp_pcbs = pcb; | |
} | |
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, | |
("udp_bind: bound to %"U16_F".%"U16_F".%"U16_F".%"U16_F", port %"U16_F"\n", | |
(u16_t)(ntohl(pcb->local_ip.addr) >> 24 & 0xff), | |
(u16_t)(ntohl(pcb->local_ip.addr) >> 16 & 0xff), | |
(u16_t)(ntohl(pcb->local_ip.addr) >> 8 & 0xff), | |
(u16_t)(ntohl(pcb->local_ip.addr) & 0xff), pcb->local_port)); | |
return ERR_OK; | |
} | |
/** | |
* Connect an UDP PCB. | |
* | |
* This will associate the UDP PCB with the remote address. | |
* | |
* @param pcb UDP PCB to be connected with remote address ipaddr and port. | |
* @param ipaddr remote IP address to connect with. | |
* @param port remote UDP port to connect with. | |
* | |
* @return lwIP error code | |
* | |
* ipaddr & port are expected to be in the same byte order as in the pcb. | |
* | |
* The udp pcb is bound to a random local port if not already bound. | |
* | |
* @see udp_disconnect() | |
*/ | |
err_t | |
udp_connect(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) | |
{ | |
struct udp_pcb *ipcb; | |
if (pcb->local_port == 0) { | |
err_t err = udp_bind(pcb, &pcb->local_ip, pcb->local_port); | |
if (err != ERR_OK) | |
return err; | |
} | |
ip_addr_set(&pcb->remote_ip, ipaddr); | |
pcb->remote_port = port; | |
pcb->flags |= UDP_FLAGS_CONNECTED; | |
/** TODO: this functionality belongs in upper layers */ | |
#ifdef LWIP_UDP_TODO | |
/* Nail down local IP for netconn_addr()/getsockname() */ | |
if (ip_addr_isany(&pcb->local_ip) && !ip_addr_isany(&pcb->remote_ip)) { | |
struct netif *netif; | |
if ((netif = ip_route(&(pcb->remote_ip))) == NULL) { | |
LWIP_DEBUGF(UDP_DEBUG, ("udp_connect: No route to 0x%lx\n", pcb->remote_ip.addr)); | |
UDP_STATS_INC(udp.rterr); | |
return ERR_RTE; | |
} | |
/** TODO: this will bind the udp pcb locally, to the interface which | |
is used to route output packets to the remote address. However, we | |
might want to accept incoming packets on any interface! */ | |
pcb->local_ip = netif->ip_addr; | |
} else if (ip_addr_isany(&pcb->remote_ip)) { | |
pcb->local_ip.addr = 0; | |
} | |
#endif | |
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, | |
("udp_connect: connected to %"U16_F".%"U16_F".%"U16_F".%"U16_F",port %"U16_F"\n", | |
(u16_t)(ntohl(pcb->remote_ip.addr) >> 24 & 0xff), | |
(u16_t)(ntohl(pcb->remote_ip.addr) >> 16 & 0xff), | |
(u16_t)(ntohl(pcb->remote_ip.addr) >> 8 & 0xff), | |
(u16_t)(ntohl(pcb->remote_ip.addr) & 0xff), pcb->remote_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; | |
} | |
} | |
/* PCB not yet on the list, add PCB now */ | |
pcb->next = udp_pcbs; | |
udp_pcbs = pcb; | |
return ERR_OK; | |
} | |
/** | |
* Disconnect a UDP PCB | |
* | |
* @param pcb the udp pcb to disconnect. | |
*/ | |
void | |
udp_disconnect(struct udp_pcb *pcb) | |
{ | |
/* reset remote address association */ | |
ip_addr_set(&pcb->remote_ip, IP_ADDR_ANY); | |
pcb->remote_port = 0; | |
/* mark PCB as unconnected */ | |
pcb->flags &= ~UDP_FLAGS_CONNECTED; | |
} | |
/** | |
* Set a receive callback for a UDP PCB | |
* | |
* This callback will be called when receiving a datagram for the pcb. | |
* | |
* @param pcb the pcb for wich to set the recv callback | |
* @param recv function pointer of the callback function | |
* @param recv_arg additional argument to pass to the callback function | |
*/ | |
void | |
udp_recv(struct udp_pcb *pcb, | |
void (* recv)(void *arg, struct udp_pcb *upcb, struct pbuf *p, | |
struct ip_addr *addr, u16_t port), | |
void *recv_arg) | |
{ | |
/* remember recv() callback and user data */ | |
pcb->recv = recv; | |
pcb->recv_arg = recv_arg; | |
} | |
/** | |
* Remove an UDP PCB. | |
* | |
* @param pcb UDP PCB to be removed. The PCB is removed from the list of | |
* UDP PCB's and the data structure is freed from memory. | |
* | |
* @see udp_new() | |
*/ | |
void | |
udp_remove(struct udp_pcb *pcb) | |
{ | |
struct udp_pcb *pcb2; | |
snmp_delete_udpidx_tree(pcb); | |
/* pcb to be removed is first in list? */ | |
if (udp_pcbs == pcb) { | |
/* make list start at 2nd pcb */ | |
udp_pcbs = udp_pcbs->next; | |
/* pcb not 1st in list */ | |
} else | |
for (pcb2 = udp_pcbs; pcb2 != NULL; pcb2 = pcb2->next) { | |
/* find pcb in udp_pcbs list */ | |
if (pcb2->next != NULL && pcb2->next == pcb) { | |
/* remove pcb from list */ | |
pcb2->next = pcb->next; | |
} | |
} | |
memp_free(MEMP_UDP_PCB, pcb); | |
} | |
/** | |
* Create a UDP PCB. | |
* | |
* @return The UDP PCB which was created. NULL if the PCB data structure | |
* could not be allocated. | |
* | |
* @see udp_remove() | |
*/ | |
struct udp_pcb * | |
udp_new(void) | |
{ | |
struct udp_pcb *pcb; | |
pcb = memp_malloc(MEMP_UDP_PCB); | |
/* could allocate UDP PCB? */ | |
if (pcb != NULL) { | |
/* UDP Lite: by initializing to all zeroes, chksum_len is set to 0 | |
* which means checksum is generated over the whole datagram per default | |
* (recommended as default by RFC 3828). */ | |
/* initialize PCB to all zeroes */ | |
memset(pcb, 0, sizeof(struct udp_pcb)); | |
pcb->ttl = UDP_TTL; | |
} | |
return pcb; | |
} | |
#if UDP_DEBUG | |
/** | |
* Print UDP header information for debug purposes. | |
* | |
* @param udphdr pointer to the udp header in memory. | |
*/ | |
void | |
udp_debug_print(struct udp_hdr *udphdr) | |
{ | |
LWIP_DEBUGF(UDP_DEBUG, ("UDP header:\n")); | |
LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); | |
LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | %5"U16_F" | (src port, dest port)\n", | |
ntohs(udphdr->src), ntohs(udphdr->dest))); | |
LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); | |
LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | 0x%04"X16_F" | (len, chksum)\n", | |
ntohs(udphdr->len), ntohs(udphdr->chksum))); | |
LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); | |
} | |
#endif /* UDP_DEBUG */ | |
#endif /* LWIP_UDP */ |