forked from lwip-tcpip/lwip
/
udp.c
1243 lines (1148 loc) · 39.7 KB
/
udp.c
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/**
* @file
* User Datagram Protocol module\n
* The code for the User Datagram Protocol UDP & UDPLite (RFC 3828).\n
* See also @ref udp_raw
*
* @defgroup udp_raw UDP
* @ingroup callbackstyle_api
* User Datagram Protocol module\n
* @see @ref raw_api and @ref netconn
*/
/*
* 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>
*
*/
/* @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_chksum.h"
#include "lwip/ip_addr.h"
#include "lwip/ip6.h"
#include "lwip/ip6_addr.h"
#include "lwip/netif.h"
#include "lwip/icmp.h"
#include "lwip/icmp6.h"
#include "lwip/stats.h"
#include "lwip/snmp.h"
#include "lwip/dhcp.h"
#include <string.h>
#ifndef UDP_LOCAL_PORT_RANGE_START
/* From http://www.iana.org/assignments/port-numbers:
"The Dynamic and/or Private Ports are those from 49152 through 65535" */
#define UDP_LOCAL_PORT_RANGE_START 0xc000
#define UDP_LOCAL_PORT_RANGE_END 0xffff
#define UDP_ENSURE_LOCAL_PORT_RANGE(port) ((u16_t)(((port) & (u16_t)~UDP_LOCAL_PORT_RANGE_START) + UDP_LOCAL_PORT_RANGE_START))
#endif
/* last local UDP port */
static u16_t udp_port = UDP_LOCAL_PORT_RANGE_START;
/* The list of UDP PCBs */
/* exported in udp.h (was static) */
struct udp_pcb *udp_pcbs;
/**
* Initialize this module.
*/
void
udp_init(void)
{
#ifdef LWIP_RAND
udp_port = UDP_ENSURE_LOCAL_PORT_RANGE(LWIP_RAND());
#endif /* LWIP_RAND */
}
/**
* Allocate a new local UDP port.
*
* @return a new (free) local UDP port number
*/
static u16_t
udp_new_port(void)
{
u16_t n = 0;
struct udp_pcb *pcb;
again:
if (udp_port++ == UDP_LOCAL_PORT_RANGE_END) {
udp_port = UDP_LOCAL_PORT_RANGE_START;
}
/* Check all PCBs. */
for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
if (pcb->local_port == udp_port) {
if (++n > (UDP_LOCAL_PORT_RANGE_END - UDP_LOCAL_PORT_RANGE_START)) {
return 0;
}
goto again;
}
}
return udp_port;
}
/** Common code to see if the current input packet matches the pcb
* (current input packet is accessed via ip(4/6)_current_* macros)
*
* @param pcb pcb to check
* @param inp network interface on which the datagram was received (only used for IPv4)
* @param broadcast 1 if his is an IPv4 broadcast (global or subnet-only), 0 otherwise (only used for IPv4)
* @return 1 on match, 0 otherwise
*/
static u8_t
udp_input_local_match(struct udp_pcb *pcb, struct netif *inp, u8_t broadcast)
{
LWIP_UNUSED_ARG(inp); /* in IPv6 only case */
LWIP_UNUSED_ARG(broadcast); /* in IPv6 only case */
/* check if PCB is bound to specific netif */
if ((pcb->netif_idx != NETIF_NO_INDEX) &&
(pcb->netif_idx != netif_get_index(ip_data.current_input_netif))) {
return 0;
}
/* Dual-stack: PCBs listening to any IP type also listen to any IP address */
if (IP_IS_ANY_TYPE_VAL(pcb->local_ip)) {
#if LWIP_IPV4 && IP_SOF_BROADCAST_RECV
if ((broadcast != 0) && !ip_get_option(pcb, SOF_BROADCAST)) {
return 0;
}
#endif /* LWIP_IPV4 && IP_SOF_BROADCAST_RECV */
return 1;
}
/* Only need to check PCB if incoming IP version matches PCB IP version */
if (IP_ADDR_PCB_VERSION_MATCH_EXACT(pcb, ip_current_dest_addr())) {
#if LWIP_IPV4
/* Special case: IPv4 broadcast: all or broadcasts in my subnet
* Note: broadcast variable can only be 1 if it is an IPv4 broadcast */
if (broadcast != 0) {
#if IP_SOF_BROADCAST_RECV
if (ip_get_option(pcb, SOF_BROADCAST))
#endif /* IP_SOF_BROADCAST_RECV */
{
if (ip4_addr_isany(ip_2_ip4(&pcb->local_ip)) ||
((ip4_current_dest_addr()->addr == IPADDR_BROADCAST)) ||
ip4_addr_netcmp(ip_2_ip4(&pcb->local_ip), ip4_current_dest_addr(), netif_ip4_netmask(inp))) {
return 1;
}
}
} else
#endif /* LWIP_IPV4 */
/* Handle IPv4 and IPv6: all or exact match */
if (ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&pcb->local_ip, ip_current_dest_addr())) {
return 1;
}
}
return 0;
}
/**
* 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_val(UDP_DEBUG, *ip_current_dest_addr());
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", lwip_ntohs(udphdr->dest)));
ip_addr_debug_print_val(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_val(UDP_DEBUG, pcb->local_ip);
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", pcb->local_port));
ip_addr_debug_print_val(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;
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;
q = pbuf_clone(PBUF_RAW, PBUF_POOL, p);
if (q != NULL) {
mpcb->recv(mpcb->recv_arg, mpcb, q, ip_current_src_addr(), src);
}
}
}
}
}
}
#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, (s16_t)(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 {
pbuf_free(p);
}
end:
PERF_STOP("udp_input");
return;
#if CHECKSUM_CHECK_UDP
chkerr:
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("udp_input: UDP (or UDP Lite) datagram discarded due to failing checksum\n"));
UDP_STATS_INC(udp.chkerr);
UDP_STATS_INC(udp.drop);
MIB2_STATS_INC(mib2.udpinerrors);
pbuf_free(p);
PERF_STOP("udp_input");
#endif /* CHECKSUM_CHECK_UDP */
}
/**
* @ingroup udp_raw
* 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 occurred.
* - ERR_MEM. Out of memory.
* - ERR_RTE. Could not find route to destination address.
* - ERR_VAL. No PCB or PCB is dual-stack
* - 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)
{
if ((pcb == NULL) || IP_IS_ANY_TYPE_VAL(pcb->remote_ip)) {
return ERR_VAL;
}
/* send to the packet using remote ip and port stored in the pcb */
return udp_sendto(pcb, p, &pcb->remote_ip, pcb->remote_port);
}
#if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
/** @ingroup udp_raw
* Same as udp_send() but with checksum
*/
err_t
udp_send_chksum(struct udp_pcb *pcb, struct pbuf *p,
u8_t have_chksum, u16_t chksum)
{
if ((pcb == NULL) || IP_IS_ANY_TYPE_VAL(pcb->remote_ip)) {
return ERR_VAL;
}
/* send to the packet using remote ip and port stored in the pcb */
return udp_sendto_chksum(pcb, p, &pcb->remote_ip, pcb->remote_port,
have_chksum, chksum);
}
#endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
/**
* @ingroup udp_raw
* 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,
const ip_addr_t *dst_ip, u16_t dst_port)
{
#if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
return udp_sendto_chksum(pcb, p, dst_ip, dst_port, 0, 0);
}
/** @ingroup udp_raw
* Same as udp_sendto(), but with checksum */
err_t
udp_sendto_chksum(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip,
u16_t dst_port, u8_t have_chksum, u16_t chksum)
{
#endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
struct netif *netif;
if ((pcb == NULL) || (dst_ip == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, dst_ip)) {
return ERR_VAL;
}
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send\n"));
if (pcb->netif_idx != NETIF_NO_INDEX) {
netif = netif_get_by_index(pcb->netif_idx);
} else {
#if LWIP_MULTICAST_TX_OPTIONS
netif = NULL;
if (ip_addr_ismulticast(dst_ip)) {
/* For IPv6, the interface to use for packets with a multicast destination
* is specified using an interface index. The same approach may be used for
* IPv4 as well, in which case it overrides the IPv4 multicast override
* address below. Here we have to look up the netif by going through the
* list, but by doing so we skip a route lookup. If the interface index has
* gone stale, we fall through and do the regular route lookup after all. */
if (pcb->mcast_ifindex != NETIF_NO_INDEX) {
netif = netif_get_by_index(pcb->mcast_ifindex);
}
#if LWIP_IPV4
else
#if LWIP_IPV6
if (IP_IS_V4(dst_ip))
#endif /* LWIP_IPV6 */
{
/* IPv4 does not use source-based routing by default, so we use an
administratively selected interface for multicast by default.
However, this can be overridden by setting an interface address
in pcb->mcast_ip4 that is used for routing. If this routing lookup
fails, we try regular routing as though no override was set. */
if (!ip4_addr_isany_val(pcb->mcast_ip4) &&
!ip4_addr_cmp(&pcb->mcast_ip4, IP4_ADDR_BROADCAST)) {
netif = ip4_route_src(ip_2_ip4(&pcb->local_ip), &pcb->mcast_ip4);
}
}
#endif /* LWIP_IPV4 */
}
if (netif == NULL)
#endif /* LWIP_MULTICAST_TX_OPTIONS */
{
/* find the outgoing network interface for this packet */
netif = ip_route(&pcb->local_ip, dst_ip);
}
}
/* no outgoing network interface could be found? */
if (netif == NULL) {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: No route to "));
ip_addr_debug_print(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, dst_ip);
LWIP_DEBUGF(UDP_DEBUG, ("\n"));
UDP_STATS_INC(udp.rterr);
return ERR_RTE;
}
#if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
return udp_sendto_if_chksum(pcb, p, dst_ip, dst_port, netif, have_chksum, chksum);
#else /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
return udp_sendto_if(pcb, p, dst_ip, dst_port, netif);
#endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
}
/**
* @ingroup udp_raw
* 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,
const ip_addr_t *dst_ip, u16_t dst_port, struct netif *netif)
{
#if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
return udp_sendto_if_chksum(pcb, p, dst_ip, dst_port, netif, 0, 0);
}
/** Same as udp_sendto_if(), but with checksum */
err_t
udp_sendto_if_chksum(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip,
u16_t dst_port, struct netif *netif, u8_t have_chksum,
u16_t chksum)
{
#endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
const ip_addr_t *src_ip;
if ((pcb == NULL) || (dst_ip == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, dst_ip)) {
return ERR_VAL;
}
/* PCB local address is IP_ANY_ADDR or multicast? */
#if LWIP_IPV6
if (IP_IS_V6(dst_ip)) {
if (ip6_addr_isany(ip_2_ip6(&pcb->local_ip)) ||
ip6_addr_ismulticast(ip_2_ip6(&pcb->local_ip))) {
src_ip = ip6_select_source_address(netif, ip_2_ip6(dst_ip));
if (src_ip == NULL) {
/* No suitable source address was found. */
return ERR_RTE;
}
} else {
/* use UDP PCB local IPv6 address as source address, if still valid. */
if (netif_get_ip6_addr_match(netif, ip_2_ip6(&pcb->local_ip)) < 0) {
/* Address isn't valid anymore. */
return ERR_RTE;
}
src_ip = &pcb->local_ip;
}
}
#endif /* LWIP_IPV6 */
#if LWIP_IPV4 && LWIP_IPV6
else
#endif /* LWIP_IPV4 && LWIP_IPV6 */
#if LWIP_IPV4
if (ip4_addr_isany(ip_2_ip4(&pcb->local_ip)) ||
ip4_addr_ismulticast(ip_2_ip4(&pcb->local_ip))) {
/* if the local_ip is any or multicast
* use the outgoing network interface IP address as source address */
src_ip = netif_ip_addr4(netif);
} else {
/* check if UDP PCB local IP address is correct
* this could be an old address if netif->ip_addr has changed */
if (!ip4_addr_cmp(ip_2_ip4(&(pcb->local_ip)), netif_ip4_addr(netif))) {
/* local_ip doesn't match, drop the packet */
return ERR_RTE;
}
/* use UDP PCB local IP address as source address */
src_ip = &pcb->local_ip;
}
#endif /* LWIP_IPV4 */
#if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
return udp_sendto_if_src_chksum(pcb, p, dst_ip, dst_port, netif, have_chksum, chksum, src_ip);
#else /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
return udp_sendto_if_src(pcb, p, dst_ip, dst_port, netif, src_ip);
#endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
}
/** @ingroup udp_raw
* Same as @ref udp_sendto_if, but with source address */
err_t
udp_sendto_if_src(struct udp_pcb *pcb, struct pbuf *p,
const ip_addr_t *dst_ip, u16_t dst_port, struct netif *netif, const ip_addr_t *src_ip)
{
#if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
return udp_sendto_if_src_chksum(pcb, p, dst_ip, dst_port, netif, 0, 0, src_ip);
}
/** Same as udp_sendto_if_src(), but with checksum */
err_t
udp_sendto_if_src_chksum(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip,
u16_t dst_port, struct netif *netif, u8_t have_chksum,
u16_t chksum, const ip_addr_t *src_ip)
{
#endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
struct udp_hdr *udphdr;
err_t err;
struct pbuf *q; /* q will be sent down the stack */
u8_t ip_proto;
u8_t ttl;
if ((pcb == NULL) || (dst_ip == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, src_ip) ||
!IP_ADDR_PCB_VERSION_MATCH(pcb, dst_ip)) {
return ERR_VAL;
}
#if LWIP_IPV4 && IP_SOF_BROADCAST
/* broadcast filter? */
if (!ip_get_option(pcb, SOF_BROADCAST) &&
#if LWIP_IPV6
IP_IS_V4(dst_ip) &&
#endif /* LWIP_IPV6 */
ip_addr_isbroadcast(dst_ip, netif)) {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
("udp_sendto_if: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
return ERR_VAL;
}
#endif /* LWIP_IPV4 && IP_SOF_BROADCAST */
/* 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, ("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 | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: forced port bind failed\n"));
return err;
}
}
/* packet too large to add a UDP header without causing an overflow? */
if ((u16_t)(p->tot_len + UDP_HLEN) < p->tot_len) {
return ERR_MEM;
}
/* 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 | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: could not allocate header\n"));
return ERR_MEM;
}
if (p->tot_len != 0) {
/* chain header q in front of given pbuf p (only if p contains data) */
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 = (struct udp_hdr *)q->payload;
udphdr->src = lwip_htons(pcb->local_port);
udphdr->dest = lwip_htons(dst_port);
/* in UDP, 0 checksum means 'no checksum' */
udphdr->chksum = 0x0000;
/* Multicast Loop? */
#if LWIP_MULTICAST_TX_OPTIONS
if (((pcb->flags & UDP_FLAGS_MULTICAST_LOOP) != 0) && ip_addr_ismulticast(dst_ip)) {
q->flags |= PBUF_FLAG_MCASTLOOP;
}
#endif /* LWIP_MULTICAST_TX_OPTIONS */
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 = lwip_htons(chklen_hdr);
/* calculate checksum */
#if CHECKSUM_GEN_UDP
IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_UDP) {
#if LWIP_CHECKSUM_ON_COPY
if (have_chksum) {
chklen = UDP_HLEN;
}
#endif /* LWIP_CHECKSUM_ON_COPY */
udphdr->chksum = ip_chksum_pseudo_partial(q, IP_PROTO_UDPLITE,
q->tot_len, chklen, src_ip, dst_ip);
#if LWIP_CHECKSUM_ON_COPY
if (have_chksum) {
u32_t acc;
acc = udphdr->chksum + (u16_t)~(chksum);
udphdr->chksum = FOLD_U32T(acc);
}
#endif /* LWIP_CHECKSUM_ON_COPY */
/* chksum zero must become 0xffff, as zero means 'no checksum' */
if (udphdr->chksum == 0x0000) {
udphdr->chksum = 0xffff;
}
}
#endif /* CHECKSUM_GEN_UDP */
ip_proto = IP_PROTO_UDPLITE;
} else
#endif /* LWIP_UDPLITE */
{ /* UDP */
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP packet length %"U16_F"\n", q->tot_len));
udphdr->len = lwip_htons(q->tot_len);
/* calculate checksum */
#if CHECKSUM_GEN_UDP
IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_UDP) {
/* Checksum is mandatory over IPv6. */
if (IP_IS_V6(dst_ip) || (pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) {
u16_t udpchksum;
#if LWIP_CHECKSUM_ON_COPY
if (have_chksum) {
u32_t acc;
udpchksum = ip_chksum_pseudo_partial(q, IP_PROTO_UDP,
q->tot_len, UDP_HLEN, src_ip, dst_ip);
acc = udpchksum + (u16_t)~(chksum);
udpchksum = FOLD_U32T(acc);
} else
#endif /* LWIP_CHECKSUM_ON_COPY */
{
udpchksum = ip_chksum_pseudo(q, IP_PROTO_UDP, q->tot_len,
src_ip, dst_ip);
}
/* chksum zero must become 0xffff, as zero means 'no checksum' */
if (udpchksum == 0x0000) {
udpchksum = 0xffff;
}
udphdr->chksum = udpchksum;
}
}
#endif /* CHECKSUM_GEN_UDP */
ip_proto = IP_PROTO_UDP;
}
/* Determine TTL to use */
#if LWIP_MULTICAST_TX_OPTIONS
ttl = (ip_addr_ismulticast(dst_ip) ? udp_get_multicast_ttl(pcb) : pcb->ttl);
#else /* LWIP_MULTICAST_TX_OPTIONS */
ttl = pcb->ttl;
#endif /* LWIP_MULTICAST_TX_OPTIONS */
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum 0x%04"X16_F"\n", udphdr->chksum));
LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,0x%02"X16_F",)\n", (u16_t)ip_proto));
/* output to IP */
NETIF_SET_HINTS(netif, &(pcb->netif_hints));
err = ip_output_if_src(q, src_ip, dst_ip, ttl, pcb->tos, ip_proto, netif);
NETIF_RESET_HINTS(netif);
/* @todo: must this be increased even if error occurred? */
MIB2_STATS_INC(mib2.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;
}
/**
* @ingroup udp_raw
* 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 IP4_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 occurred.
* - 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, const ip_addr_t *ipaddr, u16_t port)
{
struct udp_pcb *ipcb;
u8_t rebind;
#if LWIP_IPV6 && LWIP_IPV6_SCOPES
ip_addr_t zoned_ipaddr;
#endif /* LWIP_IPV6 && LWIP_IPV6_SCOPES */
#if LWIP_IPV4
/* Don't propagate NULL pointer (IPv4 ANY) to subsequent functions */
if (ipaddr == NULL) {
ipaddr = IP4_ADDR_ANY;
}
#endif /* LWIP_IPV4 */
/* still need to check for ipaddr == NULL in IPv6 only case */
if ((pcb == NULL) || (ipaddr == NULL)) {
return ERR_VAL;
}
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_bind(ipaddr = "));
ip_addr_debug_print(UDP_DEBUG | LWIP_DBG_TRACE, ipaddr);
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, (", 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) {
rebind = 1;
break;
}
}
#if LWIP_IPV6 && LWIP_IPV6_SCOPES
/* If the given IP address should have a zone but doesn't, assign one now.
* This is legacy support: scope-aware callers should always provide properly
* zoned source addresses. Do the zone selection before the address-in-use
* check below; as such we have to make a temporary copy of the address. */
if (IP_IS_V6(ipaddr) && ip6_addr_lacks_zone(ip_2_ip6(ipaddr), IP6_UNKNOWN)) {
ip_addr_copy(zoned_ipaddr, *ipaddr);
ip6_addr_select_zone(ip_2_ip6(&zoned_ipaddr), ip_2_ip6(&zoned_ipaddr));
ipaddr = &zoned_ipaddr;
}
#endif /* LWIP_IPV6 && LWIP_IPV6_SCOPES */
/* no port specified? */
if (port == 0) {
port = udp_new_port();
if (port == 0) {
/* no more ports available in local range */
LWIP_DEBUGF(UDP_DEBUG, ("udp_bind: out of free UDP ports\n"));
return ERR_USE;
}
} else {
for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
if (pcb != ipcb) {
/* By default, we don't allow to bind to a port that any other udp
PCB is already bound to, unless *all* PCBs with that port have tha
REUSEADDR flag set. */
#if SO_REUSE
if (!ip_get_option(pcb, SOF_REUSEADDR) ||
!ip_get_option(ipcb, SOF_REUSEADDR))
#endif /* SO_REUSE */
{
/* port matches that of PCB in list and REUSEADDR not set -> reject */
if ((ipcb->local_port == port) &&
/* IP address matches? */
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;
}
}
}
}
}
ip_addr_set_ipaddr(&pcb->local_ip, ipaddr);
pcb->local_port = port;
mib2_udp_bind(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 "));
ip_addr_debug_print_val(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, pcb->local_ip);
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, (", port %"U16_F")\n", pcb->local_port));
return ERR_OK;
}
/**
* @ingroup udp_raw
* Bind an UDP PCB to a specific netif.
* After calling this function, all packets received via this PCB
* are guaranteed to have come in via the specified netif, and all
* outgoing packets will go out via the specified netif.
*
* @param pcb UDP PCB to be bound.
* @param netif netif to bind udp pcb to. Can be NULL.
*
* @see udp_disconnect()
*/
void
udp_bind_netif(struct udp_pcb *pcb, const struct netif *netif)
{
if (netif != NULL) {
pcb->netif_idx = netif_get_index(netif);
} else {
pcb->netif_idx = NETIF_NO_INDEX;