AmpereMeter - Example self-announcing webserver which controls …

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Dirk-Willem van Gulik (NXP/mbed) / Mbed 2 deprecated AmpereMeter

Example self-announcing webserver which controls a servo through a smallHTML userinterface.

lwip/core/udp.c@0:a259777c45a3, 2010-08-14 (annotated)

Committer:: dirkx
Date:: Sat Aug 14 15:56:01 2010 +0000
Revision:: 0:a259777c45a3

Who changed what in which revision?

User	Revision	Line number	New contents of line
dirkx	0:a259777c45a3	1	/**
dirkx	0:a259777c45a3	2	* @file
dirkx	0:a259777c45a3	3	* User Datagram Protocol module
dirkx	0:a259777c45a3	4	*
dirkx	0:a259777c45a3	5	*/
dirkx	0:a259777c45a3	6
dirkx	0:a259777c45a3	7	/*
dirkx	0:a259777c45a3	8	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
dirkx	0:a259777c45a3	9	* All rights reserved.
dirkx	0:a259777c45a3	10	*
dirkx	0:a259777c45a3	11	* Redistribution and use in source and binary forms, with or without modification,
dirkx	0:a259777c45a3	12	* are permitted provided that the following conditions are met:
dirkx	0:a259777c45a3	13	*
dirkx	0:a259777c45a3	14	* 1. Redistributions of source code must retain the above copyright notice,
dirkx	0:a259777c45a3	15	* this list of conditions and the following disclaimer.
dirkx	0:a259777c45a3	16	* 2. Redistributions in binary form must reproduce the above copyright notice,
dirkx	0:a259777c45a3	17	* this list of conditions and the following disclaimer in the documentation
dirkx	0:a259777c45a3	18	* and/or other materials provided with the distribution.
dirkx	0:a259777c45a3	19	* 3. The name of the author may not be used to endorse or promote products
dirkx	0:a259777c45a3	20	* derived from this software without specific prior written permission.
dirkx	0:a259777c45a3	21	*
dirkx	0:a259777c45a3	22	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
dirkx	0:a259777c45a3	23	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
dirkx	0:a259777c45a3	24	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
dirkx	0:a259777c45a3	25	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
dirkx	0:a259777c45a3	26	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
dirkx	0:a259777c45a3	27	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
dirkx	0:a259777c45a3	28	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
dirkx	0:a259777c45a3	29	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
dirkx	0:a259777c45a3	30	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
dirkx	0:a259777c45a3	31	* OF SUCH DAMAGE.
dirkx	0:a259777c45a3	32	*
dirkx	0:a259777c45a3	33	* This file is part of the lwIP TCP/IP stack.
dirkx	0:a259777c45a3	34	*
dirkx	0:a259777c45a3	35	* Author: Adam Dunkels <adam@sics.se>
dirkx	0:a259777c45a3	36	*
dirkx	0:a259777c45a3	37	*/
dirkx	0:a259777c45a3	38
dirkx	0:a259777c45a3	39
dirkx	0:a259777c45a3	40	/* udp.c
dirkx	0:a259777c45a3	41	*
dirkx	0:a259777c45a3	42	* The code for the User Datagram Protocol UDP & UDPLite (RFC 3828).
dirkx	0:a259777c45a3	43	*
dirkx	0:a259777c45a3	44	*/
dirkx	0:a259777c45a3	45
dirkx	0:a259777c45a3	46	/* @todo Check the use of '(struct udp_pcb).chksum_len_rx'!
dirkx	0:a259777c45a3	47	*/
dirkx	0:a259777c45a3	48
dirkx	0:a259777c45a3	49	#include "lwip/opt.h"
dirkx	0:a259777c45a3	50
dirkx	0:a259777c45a3	51	#if LWIP_UDP /* don't build if not configured for use in lwipopts.h */
dirkx	0:a259777c45a3	52
dirkx	0:a259777c45a3	53	#include "lwip/udp.h"
dirkx	0:a259777c45a3	54	#include "lwip/def.h"
dirkx	0:a259777c45a3	55	#include "lwip/memp.h"
dirkx	0:a259777c45a3	56	#include "lwip/inet_chksum.h"
dirkx	0:a259777c45a3	57	#include "lwip/ip_addr.h"
dirkx	0:a259777c45a3	58	#include "lwip/netif.h"
dirkx	0:a259777c45a3	59	#include "lwip/icmp.h"
dirkx	0:a259777c45a3	60	#include "lwip/stats.h"
dirkx	0:a259777c45a3	61	#include "lwip/snmp.h"
dirkx	0:a259777c45a3	62	#include "arch/perf.h"
dirkx	0:a259777c45a3	63	#include "lwip/dhcp.h"
dirkx	0:a259777c45a3	64
dirkx	0:a259777c45a3	65	#include <string.h>
dirkx	0:a259777c45a3	66
dirkx	0:a259777c45a3	67	/* The list of UDP PCBs */
dirkx	0:a259777c45a3	68	/* exported in udp.h (was static) */
dirkx	0:a259777c45a3	69	struct udp_pcb *udp_pcbs;
dirkx	0:a259777c45a3	70
dirkx	0:a259777c45a3	71	/**
dirkx	0:a259777c45a3	72	* Process an incoming UDP datagram.
dirkx	0:a259777c45a3	73	*
dirkx	0:a259777c45a3	74	* Given an incoming UDP datagram (as a chain of pbufs) this function
dirkx	0:a259777c45a3	75	* finds a corresponding UDP PCB and hands over the pbuf to the pcbs
dirkx	0:a259777c45a3	76	* recv function. If no pcb is found or the datagram is incorrect, the
dirkx	0:a259777c45a3	77	* pbuf is freed.
dirkx	0:a259777c45a3	78	*
dirkx	0:a259777c45a3	79	* @param p pbuf to be demultiplexed to a UDP PCB.
dirkx	0:a259777c45a3	80	* @param inp network interface on which the datagram was received.
dirkx	0:a259777c45a3	81	*
dirkx	0:a259777c45a3	82	*/
dirkx	0:a259777c45a3	83	void
dirkx	0:a259777c45a3	84	udp_input(struct pbuf p, struct netif inp)
dirkx	0:a259777c45a3	85	{
dirkx	0:a259777c45a3	86	struct udp_hdr *udphdr;
dirkx	0:a259777c45a3	87	struct udp_pcb pcb, prev;
dirkx	0:a259777c45a3	88	struct udp_pcb *uncon_pcb;
dirkx	0:a259777c45a3	89	struct ip_hdr *iphdr;
dirkx	0:a259777c45a3	90	u16_t src, dest;
dirkx	0:a259777c45a3	91	u8_t local_match;
dirkx	0:a259777c45a3	92	u8_t broadcast;
dirkx	0:a259777c45a3	93
dirkx	0:a259777c45a3	94	PERF_START;
dirkx	0:a259777c45a3	95
dirkx	0:a259777c45a3	96	UDP_STATS_INC(udp.recv);
dirkx	0:a259777c45a3	97
dirkx	0:a259777c45a3	98	iphdr = (struct ip_hdr *)p->payload;
dirkx	0:a259777c45a3	99
dirkx	0:a259777c45a3	100	/* Check minimum length (IP header + UDP header)
dirkx	0:a259777c45a3	101	* and move payload pointer to UDP header */
dirkx	0:a259777c45a3	102	if (p->tot_len < (IPH_HL(iphdr) * 4 + UDP_HLEN) \|\| pbuf_header(p, -(s16_t)(IPH_HL(iphdr) * 4))) {
dirkx	0:a259777c45a3	103	/* drop short packets */
dirkx	0:a259777c45a3	104	LWIP_DEBUGF(UDP_DEBUG,
dirkx	0:a259777c45a3	105	("udp_input: short UDP datagram (%"U16_F" bytes) discarded\n", p->tot_len));
dirkx	0:a259777c45a3	106	UDP_STATS_INC(udp.lenerr);
dirkx	0:a259777c45a3	107	UDP_STATS_INC(udp.drop);
dirkx	0:a259777c45a3	108	snmp_inc_udpinerrors();
dirkx	0:a259777c45a3	109	pbuf_free(p);
dirkx	0:a259777c45a3	110	goto end;
dirkx	0:a259777c45a3	111	}
dirkx	0:a259777c45a3	112
dirkx	0:a259777c45a3	113	udphdr = (struct udp_hdr *)p->payload;
dirkx	0:a259777c45a3	114
dirkx	0:a259777c45a3	115	/* is broadcast packet ? */
dirkx	0:a259777c45a3	116	broadcast = ip_addr_isbroadcast(&(iphdr->dest), inp);
dirkx	0:a259777c45a3	117
dirkx	0:a259777c45a3	118	LWIP_DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %"U16_F"\n", p->tot_len));
dirkx	0:a259777c45a3	119
dirkx	0:a259777c45a3	120	/* convert src and dest ports to host byte order */
dirkx	0:a259777c45a3	121	src = ntohs(udphdr->src);
dirkx	0:a259777c45a3	122	dest = ntohs(udphdr->dest);
dirkx	0:a259777c45a3	123
dirkx	0:a259777c45a3	124	udp_debug_print(udphdr);
dirkx	0:a259777c45a3	125
dirkx	0:a259777c45a3	126	/* print the UDP source and destination */
dirkx	0:a259777c45a3	127	LWIP_DEBUGF(UDP_DEBUG,
dirkx	0:a259777c45a3	128	("udp (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") <-- "
dirkx	0:a259777c45a3	129	"(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
dirkx	0:a259777c45a3	130	ip4_addr1_16(&iphdr->dest), ip4_addr2_16(&iphdr->dest),
dirkx	0:a259777c45a3	131	ip4_addr3_16(&iphdr->dest), ip4_addr4_16(&iphdr->dest), ntohs(udphdr->dest),
dirkx	0:a259777c45a3	132	ip4_addr1_16(&iphdr->src), ip4_addr2_16(&iphdr->src),
dirkx	0:a259777c45a3	133	ip4_addr3_16(&iphdr->src), ip4_addr4_16(&iphdr->src), ntohs(udphdr->src)));
dirkx	0:a259777c45a3	134
dirkx	0:a259777c45a3	135	#if LWIP_DHCP
dirkx	0:a259777c45a3	136	pcb = NULL;
dirkx	0:a259777c45a3	137	/* when LWIP_DHCP is active, packets to DHCP_CLIENT_PORT may only be processed by
dirkx	0:a259777c45a3	138	the dhcp module, no other UDP pcb may use the local UDP port DHCP_CLIENT_PORT */
dirkx	0:a259777c45a3	139	if (dest == DHCP_CLIENT_PORT) {
dirkx	0:a259777c45a3	140	/* all packets for DHCP_CLIENT_PORT not coming from DHCP_SERVER_PORT are dropped! */
dirkx	0:a259777c45a3	141	if (src == DHCP_SERVER_PORT) {
dirkx	0:a259777c45a3	142	if ((inp->dhcp != NULL) && (inp->dhcp->pcb != NULL)) {
dirkx	0:a259777c45a3	143	/* accept the packe if
dirkx	0:a259777c45a3	144	(- broadcast or directed to us) -> DHCP is link-layer-addressed, local ip is always ANY!
dirkx	0:a259777c45a3	145	- inp->dhcp->pcb->remote == ANY or iphdr->src */
dirkx	0:a259777c45a3	146	if ((ip_addr_isany(&inp->dhcp->pcb->remote_ip) \|\|
dirkx	0:a259777c45a3	147	ip_addr_cmp(&(inp->dhcp->pcb->remote_ip), &(iphdr->src)))) {
dirkx	0:a259777c45a3	148	pcb = inp->dhcp->pcb;
dirkx	0:a259777c45a3	149	}
dirkx	0:a259777c45a3	150	}
dirkx	0:a259777c45a3	151	}
dirkx	0:a259777c45a3	152	} else
dirkx	0:a259777c45a3	153	#endif /* LWIP_DHCP */
dirkx	0:a259777c45a3	154	{
dirkx	0:a259777c45a3	155	prev = NULL;
dirkx	0:a259777c45a3	156	local_match = 0;
dirkx	0:a259777c45a3	157	uncon_pcb = NULL;
dirkx	0:a259777c45a3	158	/* Iterate through the UDP pcb list for a matching pcb.
dirkx	0:a259777c45a3	159	* 'Perfect match' pcbs (connected to the remote port & ip address) are
dirkx	0:a259777c45a3	160	* preferred. If no perfect match is found, the first unconnected pcb that
dirkx	0:a259777c45a3	161	* matches the local port and ip address gets the datagram. */
dirkx	0:a259777c45a3	162	for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
dirkx	0:a259777c45a3	163	local_match = 0;
dirkx	0:a259777c45a3	164	/* print the PCB local and remote address */
dirkx	0:a259777c45a3	165	LWIP_DEBUGF(UDP_DEBUG,
dirkx	0:a259777c45a3	166	("pcb (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") --- "
dirkx	0:a259777c45a3	167	"(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
dirkx	0:a259777c45a3	168	ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
dirkx	0:a259777c45a3	169	ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip), pcb->local_port,
dirkx	0:a259777c45a3	170	ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
dirkx	0:a259777c45a3	171	ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip), pcb->remote_port));
dirkx	0:a259777c45a3	172
dirkx	0:a259777c45a3	173	/* compare PCB local addr+port to UDP destination addr+port */
dirkx	0:a259777c45a3	174	if ((pcb->local_port == dest) &&
dirkx	0:a259777c45a3	175	((!broadcast && ip_addr_isany(&pcb->local_ip)) \|\|
dirkx	0:a259777c45a3	176	ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)) \|\|
dirkx	0:a259777c45a3	177	#if LWIP_IGMP
dirkx	0:a259777c45a3	178	ip_addr_ismulticast(&(iphdr->dest)) \|\|
dirkx	0:a259777c45a3	179	#endif /* LWIP_IGMP */
dirkx	0:a259777c45a3	180	#if IP_SOF_BROADCAST_RECV
dirkx	0:a259777c45a3	181	(broadcast && (pcb->so_options & SOF_BROADCAST)))) {
dirkx	0:a259777c45a3	182	#else /* IP_SOF_BROADCAST_RECV */
dirkx	0:a259777c45a3	183	(broadcast))) {
dirkx	0:a259777c45a3	184	#endif /* IP_SOF_BROADCAST_RECV */
dirkx	0:a259777c45a3	185	local_match = 1;
dirkx	0:a259777c45a3	186	if ((uncon_pcb == NULL) &&
dirkx	0:a259777c45a3	187	((pcb->flags & UDP_FLAGS_CONNECTED) == 0)) {
dirkx	0:a259777c45a3	188	/* the first unconnected matching PCB */
dirkx	0:a259777c45a3	189	uncon_pcb = pcb;
dirkx	0:a259777c45a3	190	}
dirkx	0:a259777c45a3	191	}
dirkx	0:a259777c45a3	192	/* compare PCB remote addr+port to UDP source addr+port */
dirkx	0:a259777c45a3	193	if ((local_match != 0) &&
dirkx	0:a259777c45a3	194	(pcb->remote_port == src) &&
dirkx	0:a259777c45a3	195	(ip_addr_isany(&pcb->remote_ip) \|\|
dirkx	0:a259777c45a3	196	ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)))) {
dirkx	0:a259777c45a3	197	/* the first fully matching PCB */
dirkx	0:a259777c45a3	198	if (prev != NULL) {
dirkx	0:a259777c45a3	199	/* move the pcb to the front of udp_pcbs so that is
dirkx	0:a259777c45a3	200	found faster next time */
dirkx	0:a259777c45a3	201	prev->next = pcb->next;
dirkx	0:a259777c45a3	202	pcb->next = udp_pcbs;
dirkx	0:a259777c45a3	203	udp_pcbs = pcb;
dirkx	0:a259777c45a3	204	} else {
dirkx	0:a259777c45a3	205	UDP_STATS_INC(udp.cachehit);
dirkx	0:a259777c45a3	206	}
dirkx	0:a259777c45a3	207	break;
dirkx	0:a259777c45a3	208	}
dirkx	0:a259777c45a3	209	prev = pcb;
dirkx	0:a259777c45a3	210	}
dirkx	0:a259777c45a3	211	/* no fully matching pcb found? then look for an unconnected pcb */
dirkx	0:a259777c45a3	212	if (pcb == NULL) {
dirkx	0:a259777c45a3	213	pcb = uncon_pcb;
dirkx	0:a259777c45a3	214	}
dirkx	0:a259777c45a3	215	}
dirkx	0:a259777c45a3	216
dirkx	0:a259777c45a3	217	/* Check checksum if this is a match or if it was directed at us. */
dirkx	0:a259777c45a3	218	if (pcb != NULL \|\| ip_addr_cmp(&inp->ip_addr, &iphdr->dest)) {
dirkx	0:a259777c45a3	219	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
dirkx	0:a259777c45a3	220	#if LWIP_UDPLITE
dirkx	0:a259777c45a3	221	if (IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) {
dirkx	0:a259777c45a3	222	/* Do the UDP Lite checksum */
dirkx	0:a259777c45a3	223	#if CHECKSUM_CHECK_UDP
dirkx	0:a259777c45a3	224	u16_t chklen = ntohs(udphdr->len);
dirkx	0:a259777c45a3	225	if (chklen < sizeof(struct udp_hdr)) {
dirkx	0:a259777c45a3	226	if (chklen == 0) {
dirkx	0:a259777c45a3	227	/* For UDP-Lite, checksum length of 0 means checksum
dirkx	0:a259777c45a3	228	over the complete packet (See RFC 3828 chap. 3.1) */
dirkx	0:a259777c45a3	229	chklen = p->tot_len;
dirkx	0:a259777c45a3	230	} else {
dirkx	0:a259777c45a3	231	/* At least the UDP-Lite header must be covered by the
dirkx	0:a259777c45a3	232	checksum! (Again, see RFC 3828 chap. 3.1) */
dirkx	0:a259777c45a3	233	UDP_STATS_INC(udp.chkerr);
dirkx	0:a259777c45a3	234	UDP_STATS_INC(udp.drop);
dirkx	0:a259777c45a3	235	snmp_inc_udpinerrors();
dirkx	0:a259777c45a3	236	pbuf_free(p);
dirkx	0:a259777c45a3	237	goto end;
dirkx	0:a259777c45a3	238	}
dirkx	0:a259777c45a3	239	}
dirkx	0:a259777c45a3	240	if (inet_chksum_pseudo_partial(p, &iphdr->src, &iphdr->dest,
dirkx	0:a259777c45a3	241	IP_PROTO_UDPLITE, p->tot_len, chklen) != 0) {
dirkx	0:a259777c45a3	242	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
dirkx	0:a259777c45a3	243	("udp_input: UDP Lite datagram discarded due to failing checksum\n"));
dirkx	0:a259777c45a3	244	UDP_STATS_INC(udp.chkerr);
dirkx	0:a259777c45a3	245	UDP_STATS_INC(udp.drop);
dirkx	0:a259777c45a3	246	snmp_inc_udpinerrors();
dirkx	0:a259777c45a3	247	pbuf_free(p);
dirkx	0:a259777c45a3	248	goto end;
dirkx	0:a259777c45a3	249	}
dirkx	0:a259777c45a3	250	#endif /* CHECKSUM_CHECK_UDP */
dirkx	0:a259777c45a3	251	} else
dirkx	0:a259777c45a3	252	#endif /* LWIP_UDPLITE */
dirkx	0:a259777c45a3	253	{
dirkx	0:a259777c45a3	254	#if CHECKSUM_CHECK_UDP
dirkx	0:a259777c45a3	255	if (udphdr->chksum != 0) {
dirkx	0:a259777c45a3	256	if (inet_chksum_pseudo(p, &iphdr->src, &iphdr->dest,
dirkx	0:a259777c45a3	257	IP_PROTO_UDP, p->tot_len) != 0) {
dirkx	0:a259777c45a3	258	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
dirkx	0:a259777c45a3	259	("udp_input: UDP datagram discarded due to failing checksum\n"));
dirkx	0:a259777c45a3	260	UDP_STATS_INC(udp.chkerr);
dirkx	0:a259777c45a3	261	UDP_STATS_INC(udp.drop);
dirkx	0:a259777c45a3	262	snmp_inc_udpinerrors();
dirkx	0:a259777c45a3	263	pbuf_free(p);
dirkx	0:a259777c45a3	264	goto end;
dirkx	0:a259777c45a3	265	}
dirkx	0:a259777c45a3	266	}
dirkx	0:a259777c45a3	267	#endif /* CHECKSUM_CHECK_UDP */
dirkx	0:a259777c45a3	268	}
dirkx	0:a259777c45a3	269	if(pbuf_header(p, -UDP_HLEN)) {
dirkx	0:a259777c45a3	270	/* Can we cope with this failing? Just assert for now */
dirkx	0:a259777c45a3	271	LWIP_ASSERT("pbuf_header failed\n", 0);
dirkx	0:a259777c45a3	272	UDP_STATS_INC(udp.drop);
dirkx	0:a259777c45a3	273	snmp_inc_udpinerrors();
dirkx	0:a259777c45a3	274	pbuf_free(p);
dirkx	0:a259777c45a3	275	goto end;
dirkx	0:a259777c45a3	276	}
dirkx	0:a259777c45a3	277	if (pcb != NULL) {
dirkx	0:a259777c45a3	278	snmp_inc_udpindatagrams();
dirkx	0:a259777c45a3	279	/* callback */
dirkx	0:a259777c45a3	280	if (pcb->recv != NULL) {
dirkx	0:a259777c45a3	281	/* now the recv function is responsible for freeing p */
dirkx	0:a259777c45a3	282	pcb->recv(pcb->recv_arg, pcb, p, &iphdr->src, src);
dirkx	0:a259777c45a3	283	} else {
dirkx	0:a259777c45a3	284	/* no recv function registered? then we have to free the pbuf! */
dirkx	0:a259777c45a3	285	pbuf_free(p);
dirkx	0:a259777c45a3	286	goto end;
dirkx	0:a259777c45a3	287	}
dirkx	0:a259777c45a3	288	} else {
dirkx	0:a259777c45a3	289	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE, ("udp_input: not for us.\n"));
dirkx	0:a259777c45a3	290
dirkx	0:a259777c45a3	291	#if LWIP_ICMP
dirkx	0:a259777c45a3	292	/* No match was found, send ICMP destination port unreachable unless
dirkx	0:a259777c45a3	293	destination address was broadcast/multicast. */
dirkx	0:a259777c45a3	294	if (!broadcast &&
dirkx	0:a259777c45a3	295	!ip_addr_ismulticast(&iphdr->dest)) {
dirkx	0:a259777c45a3	296	/* move payload pointer back to ip header */
dirkx	0:a259777c45a3	297	pbuf_header(p, (IPH_HL(iphdr) * 4) + UDP_HLEN);
dirkx	0:a259777c45a3	298	LWIP_ASSERT("p->payload == iphdr", (p->payload == iphdr));
dirkx	0:a259777c45a3	299	icmp_dest_unreach(p, ICMP_DUR_PORT);
dirkx	0:a259777c45a3	300	}
dirkx	0:a259777c45a3	301	#endif /* LWIP_ICMP */
dirkx	0:a259777c45a3	302	UDP_STATS_INC(udp.proterr);
dirkx	0:a259777c45a3	303	UDP_STATS_INC(udp.drop);
dirkx	0:a259777c45a3	304	snmp_inc_udpnoports();
dirkx	0:a259777c45a3	305	pbuf_free(p);
dirkx	0:a259777c45a3	306	}
dirkx	0:a259777c45a3	307	} else {
dirkx	0:a259777c45a3	308	pbuf_free(p);
dirkx	0:a259777c45a3	309	}
dirkx	0:a259777c45a3	310	end:
dirkx	0:a259777c45a3	311	PERF_STOP("udp_input");
dirkx	0:a259777c45a3	312	}
dirkx	0:a259777c45a3	313
dirkx	0:a259777c45a3	314	/**
dirkx	0:a259777c45a3	315	* Send data using UDP.
dirkx	0:a259777c45a3	316	*
dirkx	0:a259777c45a3	317	* @param pcb UDP PCB used to send the data.
dirkx	0:a259777c45a3	318	* @param p chain of pbuf's to be sent.
dirkx	0:a259777c45a3	319	*
dirkx	0:a259777c45a3	320	* The datagram will be sent to the current remote_ip & remote_port
dirkx	0:a259777c45a3	321	* stored in pcb. If the pcb is not bound to a port, it will
dirkx	0:a259777c45a3	322	* automatically be bound to a random port.
dirkx	0:a259777c45a3	323	*
dirkx	0:a259777c45a3	324	* @return lwIP error code.
dirkx	0:a259777c45a3	325	* - ERR_OK. Successful. No error occured.
dirkx	0:a259777c45a3	326	* - ERR_MEM. Out of memory.
dirkx	0:a259777c45a3	327	* - ERR_RTE. Could not find route to destination address.
dirkx	0:a259777c45a3	328	* - More errors could be returned by lower protocol layers.
dirkx	0:a259777c45a3	329	*
dirkx	0:a259777c45a3	330	* @see udp_disconnect() udp_sendto()
dirkx	0:a259777c45a3	331	*/
dirkx	0:a259777c45a3	332	err_t
dirkx	0:a259777c45a3	333	udp_send(struct udp_pcb pcb, struct pbuf p)
dirkx	0:a259777c45a3	334	{
dirkx	0:a259777c45a3	335	/* send to the packet using remote ip and port stored in the pcb */
dirkx	0:a259777c45a3	336	return udp_sendto(pcb, p, &pcb->remote_ip, pcb->remote_port);
dirkx	0:a259777c45a3	337	}
dirkx	0:a259777c45a3	338
dirkx	0:a259777c45a3	339	/**
dirkx	0:a259777c45a3	340	* Send data to a specified address using UDP.
dirkx	0:a259777c45a3	341	*
dirkx	0:a259777c45a3	342	* @param pcb UDP PCB used to send the data.
dirkx	0:a259777c45a3	343	* @param p chain of pbuf's to be sent.
dirkx	0:a259777c45a3	344	* @param dst_ip Destination IP address.
dirkx	0:a259777c45a3	345	* @param dst_port Destination UDP port.
dirkx	0:a259777c45a3	346	*
dirkx	0:a259777c45a3	347	* dst_ip & dst_port are expected to be in the same byte order as in the pcb.
dirkx	0:a259777c45a3	348	*
dirkx	0:a259777c45a3	349	* If the PCB already has a remote address association, it will
dirkx	0:a259777c45a3	350	* be restored after the data is sent.
dirkx	0:a259777c45a3	351	*
dirkx	0:a259777c45a3	352	* @return lwIP error code (@see udp_send for possible error codes)
dirkx	0:a259777c45a3	353	*
dirkx	0:a259777c45a3	354	* @see udp_disconnect() udp_send()
dirkx	0:a259777c45a3	355	*/
dirkx	0:a259777c45a3	356	err_t
dirkx	0:a259777c45a3	357	udp_sendto(struct udp_pcb pcb, struct pbuf p,
dirkx	0:a259777c45a3	358	ip_addr_t *dst_ip, u16_t dst_port)
dirkx	0:a259777c45a3	359	{
dirkx	0:a259777c45a3	360	struct netif *netif;
dirkx	0:a259777c45a3	361
dirkx	0:a259777c45a3	362	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE, ("udp_send\n"));
dirkx	0:a259777c45a3	363
dirkx	0:a259777c45a3	364	/* find the outgoing network interface for this packet */
dirkx	0:a259777c45a3	365	#if LWIP_IGMP
dirkx	0:a259777c45a3	366	netif = ip_route((ip_addr_ismulticast(dst_ip))?(&(pcb->multicast_ip)):(dst_ip));
dirkx	0:a259777c45a3	367	#else
dirkx	0:a259777c45a3	368	netif = ip_route(dst_ip);
dirkx	0:a259777c45a3	369	#endif /* LWIP_IGMP */
dirkx	0:a259777c45a3	370
dirkx	0:a259777c45a3	371	/* no outgoing network interface could be found? */
dirkx	0:a259777c45a3	372	if (netif == NULL) {
dirkx	0:a259777c45a3	373	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("udp_send: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
dirkx	0:a259777c45a3	374	ip4_addr1_16(dst_ip), ip4_addr2_16(dst_ip), ip4_addr3_16(dst_ip), ip4_addr4_16(dst_ip)));
dirkx	0:a259777c45a3	375	UDP_STATS_INC(udp.rterr);
dirkx	0:a259777c45a3	376	return ERR_RTE;
dirkx	0:a259777c45a3	377	}
dirkx	0:a259777c45a3	378	return udp_sendto_if(pcb, p, dst_ip, dst_port, netif);
dirkx	0:a259777c45a3	379	}
dirkx	0:a259777c45a3	380
dirkx	0:a259777c45a3	381	/**
dirkx	0:a259777c45a3	382	* Send data to a specified address using UDP.
dirkx	0:a259777c45a3	383	* The netif used for sending can be specified.
dirkx	0:a259777c45a3	384	*
dirkx	0:a259777c45a3	385	* This function exists mainly for DHCP, to be able to send UDP packets
dirkx	0:a259777c45a3	386	* on a netif that is still down.
dirkx	0:a259777c45a3	387	*
dirkx	0:a259777c45a3	388	* @param pcb UDP PCB used to send the data.
dirkx	0:a259777c45a3	389	* @param p chain of pbuf's to be sent.
dirkx	0:a259777c45a3	390	* @param dst_ip Destination IP address.
dirkx	0:a259777c45a3	391	* @param dst_port Destination UDP port.
dirkx	0:a259777c45a3	392	* @param netif the netif used for sending.
dirkx	0:a259777c45a3	393	*
dirkx	0:a259777c45a3	394	* dst_ip & dst_port are expected to be in the same byte order as in the pcb.
dirkx	0:a259777c45a3	395	*
dirkx	0:a259777c45a3	396	* @return lwIP error code (@see udp_send for possible error codes)
dirkx	0:a259777c45a3	397	*
dirkx	0:a259777c45a3	398	* @see udp_disconnect() udp_send()
dirkx	0:a259777c45a3	399	*/
dirkx	0:a259777c45a3	400	err_t
dirkx	0:a259777c45a3	401	udp_sendto_if(struct udp_pcb pcb, struct pbuf p,
dirkx	0:a259777c45a3	402	ip_addr_t dst_ip, u16_t dst_port, struct netif netif)
dirkx	0:a259777c45a3	403	{
dirkx	0:a259777c45a3	404	struct udp_hdr *udphdr;
dirkx	0:a259777c45a3	405	ip_addr_t *src_ip;
dirkx	0:a259777c45a3	406	err_t err;
dirkx	0:a259777c45a3	407	struct pbuf q; / q will be sent down the stack */
dirkx	0:a259777c45a3	408
dirkx	0:a259777c45a3	409	#if IP_SOF_BROADCAST
dirkx	0:a259777c45a3	410	/* broadcast filter? */
dirkx	0:a259777c45a3	411	if ( ((pcb->so_options & SOF_BROADCAST) == 0) && ip_addr_isbroadcast(dst_ip, netif) ) {
dirkx	0:a259777c45a3	412	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
dirkx	0:a259777c45a3	413	("udp_sendto_if: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
dirkx	0:a259777c45a3	414	return ERR_VAL;
dirkx	0:a259777c45a3	415	}
dirkx	0:a259777c45a3	416	#endif /* IP_SOF_BROADCAST */
dirkx	0:a259777c45a3	417
dirkx	0:a259777c45a3	418	/* if the PCB is not yet bound to a port, bind it here */
dirkx	0:a259777c45a3	419	if (pcb->local_port == 0) {
dirkx	0:a259777c45a3	420	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE, ("udp_send: not yet bound to a port, binding now\n"));
dirkx	0:a259777c45a3	421	err = udp_bind(pcb, &pcb->local_ip, pcb->local_port);
dirkx	0:a259777c45a3	422	if (err != ERR_OK) {
dirkx	0:a259777c45a3	423	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_SERIOUS, ("udp_send: forced port bind failed\n"));
dirkx	0:a259777c45a3	424	return err;
dirkx	0:a259777c45a3	425	}
dirkx	0:a259777c45a3	426	}
dirkx	0:a259777c45a3	427
dirkx	0:a259777c45a3	428	/* not enough space to add an UDP header to first pbuf in given p chain? */
dirkx	0:a259777c45a3	429	if (pbuf_header(p, UDP_HLEN)) {
dirkx	0:a259777c45a3	430	/* allocate header in a separate new pbuf */
dirkx	0:a259777c45a3	431	q = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM);
dirkx	0:a259777c45a3	432	/* new header pbuf could not be allocated? */
dirkx	0:a259777c45a3	433	if (q == NULL) {
dirkx	0:a259777c45a3	434	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_SERIOUS, ("udp_send: could not allocate header\n"));
dirkx	0:a259777c45a3	435	return ERR_MEM;
dirkx	0:a259777c45a3	436	}
dirkx	0:a259777c45a3	437	/* chain header q in front of given pbuf p */
dirkx	0:a259777c45a3	438	pbuf_chain(q, p);
dirkx	0:a259777c45a3	439	/* first pbuf q points to header pbuf */
dirkx	0:a259777c45a3	440	LWIP_DEBUGF(UDP_DEBUG,
dirkx	0:a259777c45a3	441	("udp_send: added header pbuf %p before given pbuf %p\n", (void )q, (void )p));
dirkx	0:a259777c45a3	442	} else {
dirkx	0:a259777c45a3	443	/* adding space for header within p succeeded */
dirkx	0:a259777c45a3	444	/* first pbuf q equals given pbuf */
dirkx	0:a259777c45a3	445	q = p;
dirkx	0:a259777c45a3	446	LWIP_DEBUGF(UDP_DEBUG, ("udp_send: added header in given pbuf %p\n", (void *)p));
dirkx	0:a259777c45a3	447	}
dirkx	0:a259777c45a3	448	LWIP_ASSERT("check that first pbuf can hold struct udp_hdr",
dirkx	0:a259777c45a3	449	(q->len >= sizeof(struct udp_hdr)));
dirkx	0:a259777c45a3	450	/* q now represents the packet to be sent */
dirkx	0:a259777c45a3	451	udphdr = (struct udp_hdr *)q->payload;
dirkx	0:a259777c45a3	452	udphdr->src = htons(pcb->local_port);
dirkx	0:a259777c45a3	453	udphdr->dest = htons(dst_port);
dirkx	0:a259777c45a3	454	/* in UDP, 0 checksum means 'no checksum' */
dirkx	0:a259777c45a3	455	udphdr->chksum = 0x0000;
dirkx	0:a259777c45a3	456
dirkx	0:a259777c45a3	457	/* PCB local address is IP_ANY_ADDR? */
dirkx	0:a259777c45a3	458	if (ip_addr_isany(&pcb->local_ip)) {
dirkx	0:a259777c45a3	459	/* use outgoing network interface IP address as source address */
dirkx	0:a259777c45a3	460	src_ip = &(netif->ip_addr);
dirkx	0:a259777c45a3	461	} else {
dirkx	0:a259777c45a3	462	/* check if UDP PCB local IP address is correct
dirkx	0:a259777c45a3	463	* this could be an old address if netif->ip_addr has changed */
dirkx	0:a259777c45a3	464	if (!ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {
dirkx	0:a259777c45a3	465	/* local_ip doesn't match, drop the packet */
dirkx	0:a259777c45a3	466	if (q != p) {
dirkx	0:a259777c45a3	467	/* free the header pbuf */
dirkx	0:a259777c45a3	468	pbuf_free(q);
dirkx	0:a259777c45a3	469	q = NULL;
dirkx	0:a259777c45a3	470	/* p is still referenced by the caller, and will live on */
dirkx	0:a259777c45a3	471	}
dirkx	0:a259777c45a3	472	return ERR_VAL;
dirkx	0:a259777c45a3	473	}
dirkx	0:a259777c45a3	474	/* use UDP PCB local IP address as source address */
dirkx	0:a259777c45a3	475	src_ip = &(pcb->local_ip);
dirkx	0:a259777c45a3	476	}
dirkx	0:a259777c45a3	477
dirkx	0:a259777c45a3	478	LWIP_DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %"U16_F"\n", q->tot_len));
dirkx	0:a259777c45a3	479
dirkx	0:a259777c45a3	480	#if LWIP_UDPLITE
dirkx	0:a259777c45a3	481	/* UDP Lite protocol? */
dirkx	0:a259777c45a3	482	if (pcb->flags & UDP_FLAGS_UDPLITE) {
dirkx	0:a259777c45a3	483	u16_t chklen, chklen_hdr;
dirkx	0:a259777c45a3	484	LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE packet length %"U16_F"\n", q->tot_len));
dirkx	0:a259777c45a3	485	/* set UDP message length in UDP header */
dirkx	0:a259777c45a3	486	chklen_hdr = chklen = pcb->chksum_len_tx;
dirkx	0:a259777c45a3	487	if ((chklen < sizeof(struct udp_hdr)) \|\| (chklen > q->tot_len)) {
dirkx	0:a259777c45a3	488	if (chklen != 0) {
dirkx	0:a259777c45a3	489	LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE pcb->chksum_len is illegal: %"U16_F"\n", chklen));
dirkx	0:a259777c45a3	490	}
dirkx	0:a259777c45a3	491	/* For UDP-Lite, checksum length of 0 means checksum
dirkx	0:a259777c45a3	492	over the complete packet. (See RFC 3828 chap. 3.1)
dirkx	0:a259777c45a3	493	At least the UDP-Lite header must be covered by the
dirkx	0:a259777c45a3	494	checksum, therefore, if chksum_len has an illegal
dirkx	0:a259777c45a3	495	value, we generate the checksum over the complete
dirkx	0:a259777c45a3	496	packet to be safe. */
dirkx	0:a259777c45a3	497	chklen_hdr = 0;
dirkx	0:a259777c45a3	498	chklen = q->tot_len;
dirkx	0:a259777c45a3	499	}
dirkx	0:a259777c45a3	500	udphdr->len = htons(chklen_hdr);
dirkx	0:a259777c45a3	501	/* calculate checksum */
dirkx	0:a259777c45a3	502	#if CHECKSUM_GEN_UDP
dirkx	0:a259777c45a3	503	udphdr->chksum = inet_chksum_pseudo_partial(q, src_ip, dst_ip,
dirkx	0:a259777c45a3	504	IP_PROTO_UDPLITE, q->tot_len, chklen);
dirkx	0:a259777c45a3	505	/* chksum zero must become 0xffff, as zero means 'no checksum' */
dirkx	0:a259777c45a3	506	if (udphdr->chksum == 0x0000) {
dirkx	0:a259777c45a3	507	udphdr->chksum = 0xffff;
dirkx	0:a259777c45a3	508	}
dirkx	0:a259777c45a3	509	#endif /* CHECKSUM_GEN_UDP */
dirkx	0:a259777c45a3	510	/* output to IP */
dirkx	0:a259777c45a3	511	LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDPLITE,)\n"));
dirkx	0:a259777c45a3	512	#if LWIP_NETIF_HWADDRHINT
dirkx	0:a259777c45a3	513	netif->addr_hint = &(pcb->addr_hint);
dirkx	0:a259777c45a3	514	#endif /* LWIP_NETIF_HWADDRHINT*/
dirkx	0:a259777c45a3	515	err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDPLITE, netif);
dirkx	0:a259777c45a3	516	#if LWIP_NETIF_HWADDRHINT
dirkx	0:a259777c45a3	517	netif->addr_hint = NULL;
dirkx	0:a259777c45a3	518	#endif /* LWIP_NETIF_HWADDRHINT*/
dirkx	0:a259777c45a3	519	} else
dirkx	0:a259777c45a3	520	#endif /* LWIP_UDPLITE */
dirkx	0:a259777c45a3	521	{ /* UDP */
dirkx	0:a259777c45a3	522	LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP packet length %"U16_F"\n", q->tot_len));
dirkx	0:a259777c45a3	523	udphdr->len = htons(q->tot_len);
dirkx	0:a259777c45a3	524	/* calculate checksum */
dirkx	0:a259777c45a3	525	#if CHECKSUM_GEN_UDP
dirkx	0:a259777c45a3	526	if ((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) {
dirkx	0:a259777c45a3	527	udphdr->chksum = inet_chksum_pseudo(q, src_ip, dst_ip, IP_PROTO_UDP, q->tot_len);
dirkx	0:a259777c45a3	528	/* chksum zero must become 0xffff, as zero means 'no checksum' */
dirkx	0:a259777c45a3	529	if (udphdr->chksum == 0x0000) {
dirkx	0:a259777c45a3	530	udphdr->chksum = 0xffff;
dirkx	0:a259777c45a3	531	}
dirkx	0:a259777c45a3	532	}
dirkx	0:a259777c45a3	533	#endif /* CHECKSUM_GEN_UDP */
dirkx	0:a259777c45a3	534	LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum 0x%04"X16_F"\n", udphdr->chksum));
dirkx	0:a259777c45a3	535	LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDP,)\n"));
dirkx	0:a259777c45a3	536	/* output to IP */
dirkx	0:a259777c45a3	537	#if LWIP_NETIF_HWADDRHINT
dirkx	0:a259777c45a3	538	netif->addr_hint = &(pcb->addr_hint);
dirkx	0:a259777c45a3	539	#endif /* LWIP_NETIF_HWADDRHINT*/
dirkx	0:a259777c45a3	540	err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDP, netif);
dirkx	0:a259777c45a3	541	#if LWIP_NETIF_HWADDRHINT
dirkx	0:a259777c45a3	542	netif->addr_hint = NULL;
dirkx	0:a259777c45a3	543	#endif /* LWIP_NETIF_HWADDRHINT*/
dirkx	0:a259777c45a3	544	}
dirkx	0:a259777c45a3	545	/* TODO: must this be increased even if error occured? */
dirkx	0:a259777c45a3	546	snmp_inc_udpoutdatagrams();
dirkx	0:a259777c45a3	547
dirkx	0:a259777c45a3	548	/* did we chain a separate header pbuf earlier? */
dirkx	0:a259777c45a3	549	if (q != p) {
dirkx	0:a259777c45a3	550	/* free the header pbuf */
dirkx	0:a259777c45a3	551	pbuf_free(q);
dirkx	0:a259777c45a3	552	q = NULL;
dirkx	0:a259777c45a3	553	/* p is still referenced by the caller, and will live on */
dirkx	0:a259777c45a3	554	}
dirkx	0:a259777c45a3	555
dirkx	0:a259777c45a3	556	UDP_STATS_INC(udp.xmit);
dirkx	0:a259777c45a3	557	return err;
dirkx	0:a259777c45a3	558	}
dirkx	0:a259777c45a3	559
dirkx	0:a259777c45a3	560	/**
dirkx	0:a259777c45a3	561	* Bind an UDP PCB.
dirkx	0:a259777c45a3	562	*
dirkx	0:a259777c45a3	563	* @param pcb UDP PCB to be bound with a local address ipaddr and port.
dirkx	0:a259777c45a3	564	* @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to
dirkx	0:a259777c45a3	565	* bind to all local interfaces.
dirkx	0:a259777c45a3	566	* @param port local UDP port to bind with. Use 0 to automatically bind
dirkx	0:a259777c45a3	567	* to a random port between UDP_LOCAL_PORT_RANGE_START and
dirkx	0:a259777c45a3	568	* UDP_LOCAL_PORT_RANGE_END.
dirkx	0:a259777c45a3	569	*
dirkx	0:a259777c45a3	570	* ipaddr & port are expected to be in the same byte order as in the pcb.
dirkx	0:a259777c45a3	571	*
dirkx	0:a259777c45a3	572	* @return lwIP error code.
dirkx	0:a259777c45a3	573	* - ERR_OK. Successful. No error occured.
dirkx	0:a259777c45a3	574	* - ERR_USE. The specified ipaddr and port are already bound to by
dirkx	0:a259777c45a3	575	* another UDP PCB.
dirkx	0:a259777c45a3	576	*
dirkx	0:a259777c45a3	577	* @see udp_disconnect()
dirkx	0:a259777c45a3	578	*/
dirkx	0:a259777c45a3	579	err_t
dirkx	0:a259777c45a3	580	udp_bind(struct udp_pcb pcb, ip_addr_t ipaddr, u16_t port)
dirkx	0:a259777c45a3	581	{
dirkx	0:a259777c45a3	582	struct udp_pcb *ipcb;
dirkx	0:a259777c45a3	583	u8_t rebind;
dirkx	0:a259777c45a3	584
dirkx	0:a259777c45a3	585	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE, ("udp_bind(ipaddr = "));
dirkx	0:a259777c45a3	586	ip_addr_debug_print(UDP_DEBUG, ipaddr);
dirkx	0:a259777c45a3	587	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE, (", port = %"U16_F")\n", port));
dirkx	0:a259777c45a3	588
dirkx	0:a259777c45a3	589	rebind = 0;
dirkx	0:a259777c45a3	590	/* Check for double bind and rebind of the same pcb */
dirkx	0:a259777c45a3	591	for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
dirkx	0:a259777c45a3	592	/* is this UDP PCB already on active list? */
dirkx	0:a259777c45a3	593	if (pcb == ipcb) {
dirkx	0:a259777c45a3	594	/* pcb may occur at most once in active list */
dirkx	0:a259777c45a3	595	LWIP_ASSERT("rebind == 0", rebind == 0);
dirkx	0:a259777c45a3	596	/* pcb already in list, just rebind */
dirkx	0:a259777c45a3	597	rebind = 1;
dirkx	0:a259777c45a3	598	}
dirkx	0:a259777c45a3	599
dirkx	0:a259777c45a3	600	/* this code does not allow upper layer to share a UDP port for
dirkx	0:a259777c45a3	601	listening to broadcast or multicast traffic (See SO_REUSEADDR and
dirkx	0:a259777c45a3	602	SO_REUSEPORT under *BSD). TODO: See where it fits instead, OR
dirkx	0:a259777c45a3	603	combine with implementation of UDP PCB flags. Leon Woestenberg. */
dirkx	0:a259777c45a3	604	#ifdef LWIP_UDP_TODO
dirkx	0:a259777c45a3	605	/* port matches that of PCB in list? */
dirkx	0:a259777c45a3	606	else {
dirkx	0:a259777c45a3	607	if ((ipcb->local_port == port) &&
dirkx	0:a259777c45a3	608	/* IP address matches, or one is IP_ADDR_ANY? */
dirkx	0:a259777c45a3	609	(ip_addr_isany(&(ipcb->local_ip)) \|\|
dirkx	0:a259777c45a3	610	ip_addr_isany(ipaddr) \|\|
dirkx	0:a259777c45a3	611	ip_addr_cmp(&(ipcb->local_ip), ipaddr))) {
dirkx	0:a259777c45a3	612	/* other PCB already binds to this local IP and port */
dirkx	0:a259777c45a3	613	LWIP_DEBUGF(UDP_DEBUG,
dirkx	0:a259777c45a3	614	("udp_bind: local port %"U16_F" already bound by another pcb\n", port));
dirkx	0:a259777c45a3	615	return ERR_USE;
dirkx	0:a259777c45a3	616	}
dirkx	0:a259777c45a3	617	}
dirkx	0:a259777c45a3	618	#endif
dirkx	0:a259777c45a3	619	}
dirkx	0:a259777c45a3	620
dirkx	0:a259777c45a3	621	ip_addr_set(&pcb->local_ip, ipaddr);
dirkx	0:a259777c45a3	622
dirkx	0:a259777c45a3	623	/* no port specified? */
dirkx	0:a259777c45a3	624	if (port == 0) {
dirkx	0:a259777c45a3	625	#ifndef UDP_LOCAL_PORT_RANGE_START
dirkx	0:a259777c45a3	626	#define UDP_LOCAL_PORT_RANGE_START 4096
dirkx	0:a259777c45a3	627	#define UDP_LOCAL_PORT_RANGE_END 0x7fff
dirkx	0:a259777c45a3	628	#endif
dirkx	0:a259777c45a3	629	port = UDP_LOCAL_PORT_RANGE_START;
dirkx	0:a259777c45a3	630	ipcb = udp_pcbs;
dirkx	0:a259777c45a3	631	while ((ipcb != NULL) && (port != UDP_LOCAL_PORT_RANGE_END)) {
dirkx	0:a259777c45a3	632	if (ipcb->local_port == port) {
dirkx	0:a259777c45a3	633	/* port is already used by another udp_pcb */
dirkx	0:a259777c45a3	634	port++;
dirkx	0:a259777c45a3	635	/* restart scanning all udp pcbs */
dirkx	0:a259777c45a3	636	ipcb = udp_pcbs;
dirkx	0:a259777c45a3	637	} else {
dirkx	0:a259777c45a3	638	/* go on with next udp pcb */
dirkx	0:a259777c45a3	639	ipcb = ipcb->next;
dirkx	0:a259777c45a3	640	}
dirkx	0:a259777c45a3	641	}
dirkx	0:a259777c45a3	642	if (ipcb != NULL) {
dirkx	0:a259777c45a3	643	/* no more ports available in local range */
dirkx	0:a259777c45a3	644	LWIP_DEBUGF(UDP_DEBUG, ("udp_bind: out of free UDP ports\n"));
dirkx	0:a259777c45a3	645	return ERR_USE;
dirkx	0:a259777c45a3	646	}
dirkx	0:a259777c45a3	647	}
dirkx	0:a259777c45a3	648	pcb->local_port = port;
dirkx	0:a259777c45a3	649	snmp_insert_udpidx_tree(pcb);
dirkx	0:a259777c45a3	650	/* pcb not active yet? */
dirkx	0:a259777c45a3	651	if (rebind == 0) {
dirkx	0:a259777c45a3	652	/* place the PCB on the active list if not already there */
dirkx	0:a259777c45a3	653	pcb->next = udp_pcbs;
dirkx	0:a259777c45a3	654	udp_pcbs = pcb;
dirkx	0:a259777c45a3	655	}
dirkx	0:a259777c45a3	656	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_STATE,
dirkx	0:a259777c45a3	657	("udp_bind: bound to %"U16_F".%"U16_F".%"U16_F".%"U16_F", port %"U16_F"\n",
dirkx	0:a259777c45a3	658	ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
dirkx	0:a259777c45a3	659	ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip),
dirkx	0:a259777c45a3	660	pcb->local_port));
dirkx	0:a259777c45a3	661	return ERR_OK;
dirkx	0:a259777c45a3	662	}
dirkx	0:a259777c45a3	663	/**
dirkx	0:a259777c45a3	664	* Connect an UDP PCB.
dirkx	0:a259777c45a3	665	*
dirkx	0:a259777c45a3	666	* This will associate the UDP PCB with the remote address.
dirkx	0:a259777c45a3	667	*
dirkx	0:a259777c45a3	668	* @param pcb UDP PCB to be connected with remote address ipaddr and port.
dirkx	0:a259777c45a3	669	* @param ipaddr remote IP address to connect with.
dirkx	0:a259777c45a3	670	* @param port remote UDP port to connect with.
dirkx	0:a259777c45a3	671	*
dirkx	0:a259777c45a3	672	* @return lwIP error code
dirkx	0:a259777c45a3	673	*
dirkx	0:a259777c45a3	674	* ipaddr & port are expected to be in the same byte order as in the pcb.
dirkx	0:a259777c45a3	675	*
dirkx	0:a259777c45a3	676	* The udp pcb is bound to a random local port if not already bound.
dirkx	0:a259777c45a3	677	*
dirkx	0:a259777c45a3	678	* @see udp_disconnect()
dirkx	0:a259777c45a3	679	*/
dirkx	0:a259777c45a3	680	err_t
dirkx	0:a259777c45a3	681	udp_connect(struct udp_pcb pcb, ip_addr_t ipaddr, u16_t port)
dirkx	0:a259777c45a3	682	{
dirkx	0:a259777c45a3	683	struct udp_pcb *ipcb;
dirkx	0:a259777c45a3	684
dirkx	0:a259777c45a3	685	if (pcb->local_port == 0) {
dirkx	0:a259777c45a3	686	err_t err = udp_bind(pcb, &pcb->local_ip, pcb->local_port);
dirkx	0:a259777c45a3	687	if (err != ERR_OK) {
dirkx	0:a259777c45a3	688	return err;
dirkx	0:a259777c45a3	689	}
dirkx	0:a259777c45a3	690	}
dirkx	0:a259777c45a3	691
dirkx	0:a259777c45a3	692	ip_addr_set(&pcb->remote_ip, ipaddr);
dirkx	0:a259777c45a3	693	pcb->remote_port = port;
dirkx	0:a259777c45a3	694	pcb->flags \|= UDP_FLAGS_CONNECTED;
dirkx	0:a259777c45a3	695	/** TODO: this functionality belongs in upper layers */
dirkx	0:a259777c45a3	696	#ifdef LWIP_UDP_TODO
dirkx	0:a259777c45a3	697	/* Nail down local IP for netconn_addr()/getsockname() */
dirkx	0:a259777c45a3	698	if (ip_addr_isany(&pcb->local_ip) && !ip_addr_isany(&pcb->remote_ip)) {
dirkx	0:a259777c45a3	699	struct netif *netif;
dirkx	0:a259777c45a3	700
dirkx	0:a259777c45a3	701	if ((netif = ip_route(&(pcb->remote_ip))) == NULL) {
dirkx	0:a259777c45a3	702	LWIP_DEBUGF(UDP_DEBUG, ("udp_connect: No route to 0x%lx\n", pcb->remote_ip.addr));
dirkx	0:a259777c45a3	703	UDP_STATS_INC(udp.rterr);
dirkx	0:a259777c45a3	704	return ERR_RTE;
dirkx	0:a259777c45a3	705	}
dirkx	0:a259777c45a3	706	/** TODO: this will bind the udp pcb locally, to the interface which
dirkx	0:a259777c45a3	707	is used to route output packets to the remote address. However, we
dirkx	0:a259777c45a3	708	might want to accept incoming packets on any interface! */
dirkx	0:a259777c45a3	709	pcb->local_ip = netif->ip_addr;
dirkx	0:a259777c45a3	710	} else if (ip_addr_isany(&pcb->remote_ip)) {
dirkx	0:a259777c45a3	711	pcb->local_ip.addr = 0;
dirkx	0:a259777c45a3	712	}
dirkx	0:a259777c45a3	713	#endif
dirkx	0:a259777c45a3	714	LWIP_DEBUGF(UDP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_STATE,
dirkx	0:a259777c45a3	715	("udp_connect: connected to %"U16_F".%"U16_F".%"U16_F".%"U16_F",port %"U16_F"\n",
dirkx	0:a259777c45a3	716	ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
dirkx	0:a259777c45a3	717	ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip),
dirkx	0:a259777c45a3	718	pcb->local_port));
dirkx	0:a259777c45a3	719
dirkx	0:a259777c45a3	720	/* Insert UDP PCB into the list of active UDP PCBs. */
dirkx	0:a259777c45a3	721	for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
dirkx	0:a259777c45a3	722	if (pcb == ipcb) {
dirkx	0:a259777c45a3	723	/* already on the list, just return */
dirkx	0:a259777c45a3	724	return ERR_OK;
dirkx	0:a259777c45a3	725	}
dirkx	0:a259777c45a3	726	}
dirkx	0:a259777c45a3	727	/* PCB not yet on the list, add PCB now */
dirkx	0:a259777c45a3	728	pcb->next = udp_pcbs;
dirkx	0:a259777c45a3	729	udp_pcbs = pcb;
dirkx	0:a259777c45a3	730	return ERR_OK;
dirkx	0:a259777c45a3	731	}
dirkx	0:a259777c45a3	732
dirkx	0:a259777c45a3	733	/**
dirkx	0:a259777c45a3	734	* Disconnect a UDP PCB
dirkx	0:a259777c45a3	735	*
dirkx	0:a259777c45a3	736	* @param pcb the udp pcb to disconnect.
dirkx	0:a259777c45a3	737	*/
dirkx	0:a259777c45a3	738	void
dirkx	0:a259777c45a3	739	udp_disconnect(struct udp_pcb *pcb)
dirkx	0:a259777c45a3	740	{
dirkx	0:a259777c45a3	741	/* reset remote address association */
dirkx	0:a259777c45a3	742	ip_addr_set_any(&pcb->remote_ip);
dirkx	0:a259777c45a3	743	pcb->remote_port = 0;
dirkx	0:a259777c45a3	744	/* mark PCB as unconnected */
dirkx	0:a259777c45a3	745	pcb->flags &= ~UDP_FLAGS_CONNECTED;
dirkx	0:a259777c45a3	746	}
dirkx	0:a259777c45a3	747
dirkx	0:a259777c45a3	748	/**
dirkx	0:a259777c45a3	749	* Set a receive callback for a UDP PCB
dirkx	0:a259777c45a3	750	*
dirkx	0:a259777c45a3	751	* This callback will be called when receiving a datagram for the pcb.
dirkx	0:a259777c45a3	752	*
dirkx	0:a259777c45a3	753	* @param pcb the pcb for wich to set the recv callback
dirkx	0:a259777c45a3	754	* @param recv function pointer of the callback function
dirkx	0:a259777c45a3	755	* @param recv_arg additional argument to pass to the callback function
dirkx	0:a259777c45a3	756	*/
dirkx	0:a259777c45a3	757	void
dirkx	0:a259777c45a3	758	udp_recv(struct udp_pcb pcb, udp_recv_fn recv, void recv_arg)
dirkx	0:a259777c45a3	759	{
dirkx	0:a259777c45a3	760	/* remember recv() callback and user data */
dirkx	0:a259777c45a3	761	pcb->recv = recv;
dirkx	0:a259777c45a3	762	pcb->recv_arg = recv_arg;
dirkx	0:a259777c45a3	763	}
dirkx	0:a259777c45a3	764
dirkx	0:a259777c45a3	765	/**
dirkx	0:a259777c45a3	766	* Remove an UDP PCB.
dirkx	0:a259777c45a3	767	*
dirkx	0:a259777c45a3	768	* @param pcb UDP PCB to be removed. The PCB is removed from the list of
dirkx	0:a259777c45a3	769	* UDP PCB's and the data structure is freed from memory.
dirkx	0:a259777c45a3	770	*
dirkx	0:a259777c45a3	771	* @see udp_new()
dirkx	0:a259777c45a3	772	*/
dirkx	0:a259777c45a3	773	void
dirkx	0:a259777c45a3	774	udp_remove(struct udp_pcb *pcb)
dirkx	0:a259777c45a3	775	{
dirkx	0:a259777c45a3	776	struct udp_pcb *pcb2;
dirkx	0:a259777c45a3	777
dirkx	0:a259777c45a3	778	snmp_delete_udpidx_tree(pcb);
dirkx	0:a259777c45a3	779	/* pcb to be removed is first in list? */
dirkx	0:a259777c45a3	780	if (udp_pcbs == pcb) {
dirkx	0:a259777c45a3	781	/* make list start at 2nd pcb */
dirkx	0:a259777c45a3	782	udp_pcbs = udp_pcbs->next;
dirkx	0:a259777c45a3	783	/* pcb not 1st in list */
dirkx	0:a259777c45a3	784	} else {
dirkx	0:a259777c45a3	785	for (pcb2 = udp_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
dirkx	0:a259777c45a3	786	/* find pcb in udp_pcbs list */
dirkx	0:a259777c45a3	787	if (pcb2->next != NULL && pcb2->next == pcb) {
dirkx	0:a259777c45a3	788	/* remove pcb from list */
dirkx	0:a259777c45a3	789	pcb2->next = pcb->next;
dirkx	0:a259777c45a3	790	}
dirkx	0:a259777c45a3	791	}
dirkx	0:a259777c45a3	792	}
dirkx	0:a259777c45a3	793	memp_free(MEMP_UDP_PCB, pcb);
dirkx	0:a259777c45a3	794	}
dirkx	0:a259777c45a3	795
dirkx	0:a259777c45a3	796	/**
dirkx	0:a259777c45a3	797	* Create a UDP PCB.
dirkx	0:a259777c45a3	798	*
dirkx	0:a259777c45a3	799	* @return The UDP PCB which was created. NULL if the PCB data structure
dirkx	0:a259777c45a3	800	* could not be allocated.
dirkx	0:a259777c45a3	801	*
dirkx	0:a259777c45a3	802	* @see udp_remove()
dirkx	0:a259777c45a3	803	*/
dirkx	0:a259777c45a3	804	struct udp_pcb *
dirkx	0:a259777c45a3	805	udp_new(void)
dirkx	0:a259777c45a3	806	{
dirkx	0:a259777c45a3	807	struct udp_pcb *pcb;
dirkx	0:a259777c45a3	808	pcb = (struct udp_pcb *)memp_malloc(MEMP_UDP_PCB);
dirkx	0:a259777c45a3	809	/* could allocate UDP PCB? */
dirkx	0:a259777c45a3	810	if (pcb != NULL) {
dirkx	0:a259777c45a3	811	/* UDP Lite: by initializing to all zeroes, chksum_len is set to 0
dirkx	0:a259777c45a3	812	* which means checksum is generated over the whole datagram per default
dirkx	0:a259777c45a3	813	* (recommended as default by RFC 3828). */
dirkx	0:a259777c45a3	814	/* initialize PCB to all zeroes */
dirkx	0:a259777c45a3	815	memset(pcb, 0, sizeof(struct udp_pcb));
dirkx	0:a259777c45a3	816	pcb->ttl = UDP_TTL;
dirkx	0:a259777c45a3	817	}
dirkx	0:a259777c45a3	818	return pcb;
dirkx	0:a259777c45a3	819	}
dirkx	0:a259777c45a3	820
dirkx	0:a259777c45a3	821	#if UDP_DEBUG
dirkx	0:a259777c45a3	822	/**
dirkx	0:a259777c45a3	823	* Print UDP header information for debug purposes.
dirkx	0:a259777c45a3	824	*
dirkx	0:a259777c45a3	825	* @param udphdr pointer to the udp header in memory.
dirkx	0:a259777c45a3	826	*/
dirkx	0:a259777c45a3	827	void
dirkx	0:a259777c45a3	828	udp_debug_print(struct udp_hdr *udphdr)
dirkx	0:a259777c45a3	829	{
dirkx	0:a259777c45a3	830	LWIP_DEBUGF(UDP_DEBUG, ("UDP header:\n"));
dirkx	0:a259777c45a3	831	LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	832	LWIP_DEBUGF(UDP_DEBUG, ("\| %5"U16_F" \| %5"U16_F" \| (src port, dest port)\n",
dirkx	0:a259777c45a3	833	ntohs(udphdr->src), ntohs(udphdr->dest)));
dirkx	0:a259777c45a3	834	LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	835	LWIP_DEBUGF(UDP_DEBUG, ("\| %5"U16_F" \| 0x%04"X16_F" \| (len, chksum)\n",
dirkx	0:a259777c45a3	836	ntohs(udphdr->len), ntohs(udphdr->chksum)));
dirkx	0:a259777c45a3	837	LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	838	}
dirkx	0:a259777c45a3	839	#endif /* UDP_DEBUG */
dirkx	0:a259777c45a3	840
dirkx	0:a259777c45a3	841	#endif /* LWIP_UDP */

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	14 Aug 2010
Imports:	49
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	2
Followers:	1

lwip/core/udp.c@0:a259777c45a3, 2010-08-14 (annotated)

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