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8ac1b4825a
lwip/src/core/udp.c
Joel Cunningham 8ac1b4825a udp: use netif addr as src for multicast sockets 
Sockets bound to a multicast address could not transmit multicast
packets because the pcb local address did not match the netif address
even if the outgoing netif was resolved correctly.

To correct the issue, pcbs with a multicast local address will use
the outgoing netif address as the source address in IPv4.
2016-04-18 16:36:13 -04:00

1205 lines
38 KiB
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/**
* @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_chksum.h"
#include "lwip/ip_addr.h"
#include "lwip/ip6.h"
#include "lwip/ip6_addr.h"
#include "lwip/inet_chksum.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) & ~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)
{
#if LWIP_RANDOMIZE_INITIAL_LOCAL_PORTS && defined(LWIP_RAND)
udp_port = UDP_ENSURE_LOCAL_PORT_RANGE(LWIP_RAND());
#endif /* LWIP_RANDOMIZE_INITIAL_LOCAL_PORTS && defined(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;
#if 0
struct udp_pcb *ipcb = udp_pcbs;
while ((ipcb != NULL) && (udp_port != UDP_LOCAL_PORT_RANGE_END)) {
if (ipcb->local_port == udp_port) {
/* port is already used by another udp_pcb */
udp_port++;
/* restart scanning all udp pcbs */
ipcb = udp_pcbs;
} else {
/* go on with next udp pcb */
ipcb = ipcb->next;
}
}
if (ipcb != NULL) {
return 0;
}
return udp_port;
#endif
}
/** 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 */
/* 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, multicast or exact match */
if(ip_addr_isany(&pcb->local_ip) ||
#if LWIP_IPV6_MLD
(ip_current_is_v6() && ip6_addr_ismulticast(ip6_current_dest_addr())) ||
#endif /* LWIP_IPV6_MLD */
#if LWIP_IGMP
(!ip_current_is_v6() && ip4_addr_ismulticast(ip4_current_dest_addr())) ||
#endif /* LWIP_IGMP */
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 = ntohs(udphdr->src);
dest = ntohs(udphdr->dest);
udp_debug_print(udphdr);
/* print the UDP source and destination */
LWIP_DEBUGF(UDP_DEBUG, ("udp ("));
ip_addr_debug_print(UDP_DEBUG, ip_current_dest_addr());
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", ntohs(udphdr->dest)));
ip_addr_debug_print(UDP_DEBUG, ip_current_src_addr());
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F")\n", ntohs(udphdr->src)));
pcb = NULL;
prev = NULL;
uncon_pcb = NULL;
/* Iterate through the UDP pcb list for a matching pcb.
* 'Perfect match' pcbs (connected to the remote port & ip address) are
* preferred. If no perfect match is found, the first unconnected pcb that
* matches the local port and ip address gets the datagram. */
for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
/* print the PCB local and remote address */
LWIP_DEBUGF(UDP_DEBUG, ("pcb ("));
ip_addr_debug_print(UDP_DEBUG, &pcb->local_ip);
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", pcb->local_port));
ip_addr_debug_print(UDP_DEBUG, &pcb->remote_ip);
LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F")\n", pcb->remote_port));
/* compare PCB local addr+port to UDP destination addr+port */
if ((pcb->local_port == dest) &&
(udp_input_local_match(pcb, inp, broadcast) != 0)) {
if (((pcb->flags & UDP_FLAGS_CONNECTED) == 0) &&
((uncon_pcb == NULL)
#if SO_REUSE
/* prefer specific IPs over cath-all */
|| !ip_addr_isany(&pcb->local_ip)
#endif /* SO_REUSE */
)) {
/* the first unconnected matching PCB */
uncon_pcb = pcb;
}
/* compare PCB remote addr+port to UDP source addr+port */
if ((pcb->remote_port == src) &&
(ip_addr_isany_val(pcb->remote_ip) ||
ip_addr_cmp(&pcb->remote_ip, ip_current_src_addr()))) {
/* the first fully matching PCB */
if (prev != NULL) {
/* move the pcb to the front of udp_pcbs so that is
found faster next time */
prev->next = pcb->next;
pcb->next = udp_pcbs;
udp_pcbs = pcb;
} else {
UDP_STATS_INC(udp.cachehit);
}
break;
}
}
prev = pcb;
}
/* no fully matching pcb found? then look for an unconnected pcb */
if (pcb == NULL) {
pcb = uncon_pcb;
}
/* Check checksum if this is a match or if it was directed at us. */
if (pcb != NULL) {
for_us = 1;
} else {
#if LWIP_IPV6
if (ip_current_is_v6()) {
for_us = netif_get_ip6_addr_match(inp, ip6_current_dest_addr()) >= 0;
}
#endif /* LWIP_IPV6 */
#if LWIP_IPV4
if (!ip_current_is_v6()) {
for_us = ip4_addr_cmp(netif_ip4_addr(inp), ip4_current_dest_addr());
}
#endif /* LWIP_IPV4 */
}
if (for_us) {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
#if CHECKSUM_CHECK_UDP
IF__NETIF_CHECKSUM_ENABLED(inp, CHECKSUM_CHECK_UDP) {
#if LWIP_UDPLITE
if (ip_current_header_proto() == IP_PROTO_UDPLITE) {
/* Do the UDP Lite checksum */
u16_t chklen = ntohs(udphdr->len);
if (chklen < sizeof(struct udp_hdr)) {
if (chklen == 0) {
/* For UDP-Lite, checksum length of 0 means checksum
over the complete packet (See RFC 3828 chap. 3.1) */
chklen = p->tot_len;
} else {
/* At least the UDP-Lite header must be covered by the
checksum! (Again, see RFC 3828 chap. 3.1) */
goto chkerr;
}
}
if (ip_chksum_pseudo_partial(p, IP_PROTO_UDPLITE,
p->tot_len, chklen,
ip_current_src_addr(), ip_current_dest_addr()) != 0) {
goto chkerr;
}
} else
#endif /* LWIP_UDPLITE */
{
if (udphdr->chksum != 0) {
if (ip_chksum_pseudo(p, IP_PROTO_UDP, p->tot_len,
ip_current_src_addr(),
ip_current_dest_addr()) != 0) {
goto chkerr;
}
}
}
}
#endif /* CHECKSUM_CHECK_UDP */
if (pbuf_header(p, -UDP_HLEN)) {
/* Can we cope with this failing? Just assert for now */
LWIP_ASSERT("pbuf_header failed\n", 0);
UDP_STATS_INC(udp.drop);
MIB2_STATS_INC(mib2.udpinerrors);
pbuf_free(p);
goto end;
}
if (pcb != NULL) {
MIB2_STATS_INC(mib2.udpindatagrams);
#if SO_REUSE && SO_REUSE_RXTOALL
if (ip_get_option(pcb, SOF_REUSEADDR) &&
(broadcast || ip_addr_ismulticast(ip_current_dest_addr()))) {
/* pass broadcast- or multicast packets to all multicast pcbs
if SOF_REUSEADDR is set on the first match */
struct udp_pcb *mpcb;
u8_t p_header_changed = 0;
s16_t hdrs_len = (s16_t)(ip_current_header_tot_len() + UDP_HLEN);
for (mpcb = udp_pcbs; mpcb != NULL; mpcb = mpcb->next) {
if (mpcb != pcb) {
/* compare PCB local addr+port to UDP destination addr+port */
if ((mpcb->local_port == dest) &&
(udp_input_local_match(mpcb, inp, broadcast) != 0)) {
/* pass a copy of the packet to all local matches */
if (mpcb->recv != NULL) {
struct pbuf *q;
/* for that, move payload to IP header again */
if (p_header_changed == 0) {
pbuf_header_force(p, hdrs_len);
p_header_changed = 1;
}
q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
if (q != NULL) {
err_t err = pbuf_copy(q, p);
if (err == ERR_OK) {
/* move payload to UDP data */
pbuf_header(q, -hdrs_len);
mpcb->recv(mpcb->recv_arg, mpcb, q, ip_current_src_addr(), src);
}
}
}
}
}
}
if (p_header_changed) {
/* and move payload to UDP data again */
pbuf_header(p, -hdrs_len);
}
}
#endif /* SO_REUSE && SO_REUSE_RXTOALL */
/* callback */
if (pcb->recv != NULL) {
/* now the recv function is responsible for freeing p */
pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr(), src);
} else {
/* no recv function registered? then we have to free the pbuf! */
pbuf_free(p);
goto end;
}
} else {
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: not for us.\n"));
#if LWIP_ICMP || LWIP_ICMP6
/* No match was found, send ICMP destination port unreachable unless
destination address was broadcast/multicast. */
if (!broadcast && !ip_addr_ismulticast(ip_current_dest_addr())) {
/* move payload pointer back to ip header */
pbuf_header_force(p, ip_current_header_tot_len() + UDP_HLEN);
icmp_port_unreach(ip_current_is_v6(), p);
}
#endif /* LWIP_ICMP || LWIP_ICMP6 */
UDP_STATS_INC(udp.proterr);
UDP_STATS_INC(udp.drop);
MIB2_STATS_INC(mib2.udpnoports);
pbuf_free(p);
}
} else {
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 */
}
/**
* 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
/** 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 */
/**
* 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);
}
/** 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;
const ip_addr_t *dst_ip_route = dst_ip;
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 LWIP_IPV6 || (LWIP_IPV4 && LWIP_MULTICAST_TX_OPTIONS)
if (ip_addr_ismulticast(dst_ip_route)) {
#if LWIP_IPV6
if (IP_IS_V6(dst_ip)) {
/* For multicast, find a netif based on source address. */
dst_ip_route = &pcb->local_ip;
} else
#endif /* LWIP_IPV6 */
{
#if LWIP_IPV4 && LWIP_MULTICAST_TX_OPTIONS
/* 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->multicast_ip that is used for routing. */
if (!ip_addr_isany_val(pcb->multicast_ip) &&
!ip4_addr_cmp(ip_2_ip4(&pcb->multicast_ip), IP4_ADDR_BROADCAST)) {
dst_ip_route = &pcb->multicast_ip;
}
#endif /* LWIP_IPV4 && LWIP_MULTICAST_TX_OPTIONS */
}
}
#endif /* LWIP_IPV6 || (LWIP_IPV4 && LWIP_MULTICAST_TX_OPTIONS) */
/* find the outgoing network interface for this packet */
netif = ip_route(&pcb->local_ip, dst_ip_route);
/* 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 */
}
/**
* 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? */
#if LWIP_IPV6
if (IP_IS_V6(dst_ip)) {
if (ip6_addr_isany(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_VAL;
}
/* 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 */
}
/** Same as 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;
}
}
/* 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 = htons(pcb->local_port);
udphdr->dest = htons(dst_port);
/* in UDP, 0 checksum means 'no checksum' */
udphdr->chksum = 0x0000;
/* Multicast Loop? */
#if (LWIP_IPV4 && LWIP_MULTICAST_TX_OPTIONS) || (LWIP_IPV6 && LWIP_IPV6_MLD)
if (((pcb->flags & UDP_FLAGS_MULTICAST_LOOP) != 0) && ip_addr_ismulticast(dst_ip)) {
q->flags |= PBUF_FLAG_MCASTLOOP;
}
#endif /* (LWIP_IPV4 && LWIP_MULTICAST_TX_OPTIONS) || (LWIP_IPV6 && LWIP_IPV6_MLD) */
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
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 = 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) ? pcb->mcast_ttl : 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_HWADDRHINT(netif, &(pcb->addr_hint));
err = ip_output_if_src(q, src_ip, dst_ip, ttl, pcb->tos, ip_proto, netif);
NETIF_SET_HWADDRHINT(netif, NULL);
/* 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;
}
/**
* 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 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_IPV4
/* Don't propagate NULL pointer (IPv4 ANY) to subsequent functions */
if (ipaddr == NULL) {
ipaddr = IP_ADDR_ANY;
}
#endif /* LWIP_IPV4 */
/* still need to check for ipaddr == NULL in IPv6 only case */
if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH_EXACT(pcb, ipaddr)) {
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;
}
}
/* 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(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;
}
/**
* 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, const ip_addr_t *ipaddr, u16_t port)
{
struct udp_pcb *ipcb;
if ((pcb == NULL) || (ipaddr == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, ipaddr)) {
return ERR_VAL;
}
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_ipaddr(&pcb->remote_ip, ipaddr);
pcb->remote_port = port;
pcb->flags |= UDP_FLAGS_CONNECTED;
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("udp_connect: connected to "));
ip_addr_debug_print(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
&pcb->remote_ip);
LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, (", port %"U16_F")\n", 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 */
#if LWIP_IPV4 && LWIP_IPV6
if(IP_IS_ANY_TYPE_VAL(pcb->local_ip)) {
ip_addr_copy(pcb->remote_ip, *IP_ANY_TYPE);
} else {
#endif
ip_addr_set_any(IP_IS_V6_VAL(pcb->remote_ip), &pcb->remote_ip);
#if LWIP_IPV4 && LWIP_IPV6
}
#endif
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 which 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, udp_recv_fn recv, 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;
mib2_udp_unbind(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;
break;
}
}
}
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 = (struct udp_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;
#if LWIP_MULTICAST_TX_OPTIONS
pcb->mcast_ttl = UDP_TTL;
#endif /* LWIP_MULTICAST_TX_OPTIONS */
}
return pcb;
}
/**
* Create a UDP PCB for specific IP type.
*
* @param type IP address type, see IPADDR_TYPE_XX definitions.
* @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_ip_type(u8_t type)
{
struct udp_pcb *pcb;
pcb = udp_new();
#if LWIP_IPV4 && LWIP_IPV6
if(pcb != NULL) {
IP_SET_TYPE_VAL(pcb->local_ip, type);
IP_SET_TYPE_VAL(pcb->remote_ip, type);
}
#else
LWIP_UNUSED_ARG(type);
#endif /* LWIP_IPV4 && LWIP_IPV6 */
return pcb;
}
#if LWIP_IPV4
/** This function is called from netif.c when address is changed
*
* @param old_addr IPv4 address of the netif before change
* @param new_addr IPv4 address of the netif after change
*/
void udp_netif_ipv4_addr_changed(const ip4_addr_t* old_addr, const ip4_addr_t* new_addr)
{
struct udp_pcb* upcb;
if (!ip4_addr_isany(new_addr)) {
for (upcb = udp_pcbs; upcb != NULL; upcb = upcb->next) {
/* Is this an IPv4 pcb? */
if (IP_IS_V4_VAL(upcb->local_ip)) {
/* PCB bound to current local interface address? */
if (!ip4_addr_isany(ip_2_ip4(&upcb->local_ip)) &&
ip4_addr_cmp(ip_2_ip4(&upcb->local_ip), old_addr)) {
/* The PCB is bound to the old ipaddr and
* is set to bound to the new one instead */
ip_addr_copy_from_ip4(upcb->local_ip, *new_addr);
}
}
}
}
}
#endif /* LWIP_IPV4 */
#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 */
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