source: UsbWattMeter/trunk/lwip-1.4.1/src/core/udp.c

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1/**
2 * @file
3 * User Datagram Protocol module
4 *
5 */
6
7/*
8 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without modification,
12 * are permitted provided that the following conditions are met:
13 *
14 * 1. Redistributions of source code must retain the above copyright notice,
15 * this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright notice,
17 * this list of conditions and the following disclaimer in the documentation
18 * and/or other materials provided with the distribution.
19 * 3. The name of the author may not be used to endorse or promote products
20 * derived from this software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
25 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
26 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
27 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
30 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
31 * OF SUCH DAMAGE.
32 *
33 * This file is part of the lwIP TCP/IP stack.
34 *
35 * Author: Adam Dunkels <adam@sics.se>
36 *
37 */
38
39
40/* udp.c
41 *
42 * The code for the User Datagram Protocol UDP & UDPLite (RFC 3828).
43 *
44 */
45
46/* @todo Check the use of '(struct udp_pcb).chksum_len_rx'!
47 */
48
49#include "lwip/opt.h"
50
51#if LWIP_UDP /* don't build if not configured for use in lwipopts.h */
52
53#include "lwip/udp.h"
54#include "lwip/def.h"
55#include "lwip/memp.h"
56#include "lwip/inet_chksum.h"
57#include "lwip/ip_addr.h"
58#include "lwip/netif.h"
59#include "lwip/icmp.h"
60#include "lwip/stats.h"
61#include "lwip/snmp.h"
62#include "arch/perf.h"
63#include "lwip/dhcp.h"
64
65#include <string.h>
66
67#ifndef UDP_LOCAL_PORT_RANGE_START
68/* From http://www.iana.org/assignments/port-numbers:
69 "The Dynamic and/or Private Ports are those from 49152 through 65535" */
70#define UDP_LOCAL_PORT_RANGE_START 0xc000
71#define UDP_LOCAL_PORT_RANGE_END 0xffff
72#define UDP_ENSURE_LOCAL_PORT_RANGE(port) (((port) & ~UDP_LOCAL_PORT_RANGE_START) + UDP_LOCAL_PORT_RANGE_START)
73#endif
74
75/* last local UDP port */
76static u16_t udp_port = UDP_LOCAL_PORT_RANGE_START;
77
78/* The list of UDP PCBs */
79/* exported in udp.h (was static) */
80struct udp_pcb *udp_pcbs;
81
82/**
83 * Initialize this module.
84 */
85void
86udp_init(void)
87{
88#if LWIP_RANDOMIZE_INITIAL_LOCAL_PORTS && defined(LWIP_RAND)
89 udp_port = UDP_ENSURE_LOCAL_PORT_RANGE(LWIP_RAND());
90#endif /* LWIP_RANDOMIZE_INITIAL_LOCAL_PORTS && defined(LWIP_RAND) */
91}
92
93/**
94 * Allocate a new local UDP port.
95 *
96 * @return a new (free) local UDP port number
97 */
98static u16_t
99udp_new_port(void)
100{
101 u16_t n = 0;
102 struct udp_pcb *pcb;
103
104again:
105 if (udp_port++ == UDP_LOCAL_PORT_RANGE_END) {
106 udp_port = UDP_LOCAL_PORT_RANGE_START;
107 }
108 /* Check all PCBs. */
109 for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
110 if (pcb->local_port == udp_port) {
111 if (++n > (UDP_LOCAL_PORT_RANGE_END - UDP_LOCAL_PORT_RANGE_START)) {
112 return 0;
113 }
114 goto again;
115 }
116 }
117 return udp_port;
118#if 0
119 struct udp_pcb *ipcb = udp_pcbs;
120 while ((ipcb != NULL) && (udp_port != UDP_LOCAL_PORT_RANGE_END)) {
121 if (ipcb->local_port == udp_port) {
122 /* port is already used by another udp_pcb */
123 udp_port++;
124 /* restart scanning all udp pcbs */
125 ipcb = udp_pcbs;
126 } else {
127 /* go on with next udp pcb */
128 ipcb = ipcb->next;
129 }
130 }
131 if (ipcb != NULL) {
132 return 0;
133 }
134 return udp_port;
135#endif
136}
137
138/**
139 * Process an incoming UDP datagram.
140 *
141 * Given an incoming UDP datagram (as a chain of pbufs) this function
142 * finds a corresponding UDP PCB and hands over the pbuf to the pcbs
143 * recv function. If no pcb is found or the datagram is incorrect, the
144 * pbuf is freed.
145 *
146 * @param p pbuf to be demultiplexed to a UDP PCB.
147 * @param inp network interface on which the datagram was received.
148 *
149 */
150void
151udp_input(struct pbuf *p, struct netif *inp)
152{
153 struct udp_hdr *udphdr;
154 struct udp_pcb *pcb, *prev;
155 struct udp_pcb *uncon_pcb;
156 struct ip_hdr *iphdr;
157 u16_t src, dest;
158 u8_t local_match;
159 u8_t broadcast;
160
161 PERF_START;
162
163 UDP_STATS_INC(udp.recv);
164
165 iphdr = (struct ip_hdr *)p->payload;
166
167 /* Check minimum length (IP header + UDP header)
168 * and move payload pointer to UDP header */
169 if (p->tot_len < (IPH_HL(iphdr) * 4 + UDP_HLEN) || pbuf_header(p, -(s16_t)(IPH_HL(iphdr) * 4))) {
170 /* drop short packets */
171 LWIP_DEBUGF(UDP_DEBUG,
172 ("udp_input: short UDP datagram (%"U16_F" bytes) discarded\n", p->tot_len));
173 UDP_STATS_INC(udp.lenerr);
174 UDP_STATS_INC(udp.drop);
175 snmp_inc_udpinerrors();
176 pbuf_free(p);
177 goto end;
178 }
179
180 udphdr = (struct udp_hdr *)p->payload;
181
182 /* is broadcast packet ? */
183 broadcast = ip_addr_isbroadcast(&current_iphdr_dest, inp);
184
185 LWIP_DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %"U16_F"\n", p->tot_len));
186
187 /* convert src and dest ports to host byte order */
188 src = ntohs(udphdr->src);
189 dest = ntohs(udphdr->dest);
190
191 udp_debug_print(udphdr);
192
193 /* print the UDP source and destination */
194 LWIP_DEBUGF(UDP_DEBUG,
195 ("udp (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") <-- "
196 "(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
197 ip4_addr1_16(&iphdr->dest), ip4_addr2_16(&iphdr->dest),
198 ip4_addr3_16(&iphdr->dest), ip4_addr4_16(&iphdr->dest), ntohs(udphdr->dest),
199 ip4_addr1_16(&iphdr->src), ip4_addr2_16(&iphdr->src),
200 ip4_addr3_16(&iphdr->src), ip4_addr4_16(&iphdr->src), ntohs(udphdr->src)));
201
202#if LWIP_DHCP
203 pcb = NULL;
204 /* when LWIP_DHCP is active, packets to DHCP_CLIENT_PORT may only be processed by
205 the dhcp module, no other UDP pcb may use the local UDP port DHCP_CLIENT_PORT */
206 if (dest == DHCP_CLIENT_PORT) {
207 /* all packets for DHCP_CLIENT_PORT not coming from DHCP_SERVER_PORT are dropped! */
208 if (src == DHCP_SERVER_PORT) {
209 if ((inp->dhcp != NULL) && (inp->dhcp->pcb != NULL)) {
210 /* accept the packe if
211 (- broadcast or directed to us) -> DHCP is link-layer-addressed, local ip is always ANY!
212 - inp->dhcp->pcb->remote == ANY or iphdr->src */
213 if ((ip_addr_isany(&inp->dhcp->pcb->remote_ip) ||
214 ip_addr_cmp(&(inp->dhcp->pcb->remote_ip), &current_iphdr_src))) {
215 pcb = inp->dhcp->pcb;
216 }
217 }
218 }
219 } else
220#endif /* LWIP_DHCP */
221 {
222 prev = NULL;
223 local_match = 0;
224 uncon_pcb = NULL;
225 /* Iterate through the UDP pcb list for a matching pcb.
226 * 'Perfect match' pcbs (connected to the remote port & ip address) are
227 * preferred. If no perfect match is found, the first unconnected pcb that
228 * matches the local port and ip address gets the datagram. */
229 for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
230 local_match = 0;
231 /* print the PCB local and remote address */
232 LWIP_DEBUGF(UDP_DEBUG,
233 ("pcb (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") --- "
234 "(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
235 ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
236 ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip), pcb->local_port,
237 ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
238 ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip), pcb->remote_port));
239
240 /* compare PCB local addr+port to UDP destination addr+port */
241 if (pcb->local_port == dest) {
242 if (
243 (!broadcast && ip_addr_isany(&pcb->local_ip)) ||
244 ip_addr_cmp(&(pcb->local_ip), &current_iphdr_dest) ||
245#if LWIP_IGMP
246 ip_addr_ismulticast(&current_iphdr_dest) ||
247#endif /* LWIP_IGMP */
248#if IP_SOF_BROADCAST_RECV
249 (broadcast && ip_get_option(pcb, SOF_BROADCAST) &&
250 (ip_addr_isany(&pcb->local_ip) ||
251 ip_addr_netcmp(&pcb->local_ip, ip_current_dest_addr(), &inp->netmask)))) {
252#else /* IP_SOF_BROADCAST_RECV */
253 (broadcast &&
254 (ip_addr_isany(&pcb->local_ip) ||
255 ip_addr_netcmp(&pcb->local_ip, ip_current_dest_addr(), &inp->netmask)))) {
256#endif /* IP_SOF_BROADCAST_RECV */
257 local_match = 1;
258 if ((uncon_pcb == NULL) &&
259 ((pcb->flags & UDP_FLAGS_CONNECTED) == 0)) {
260 /* the first unconnected matching PCB */
261 uncon_pcb = pcb;
262 }
263 }
264 }
265 /* compare PCB remote addr+port to UDP source addr+port */
266 if ((local_match != 0) &&
267 (pcb->remote_port == src) &&
268 (ip_addr_isany(&pcb->remote_ip) ||
269 ip_addr_cmp(&(pcb->remote_ip), &current_iphdr_src))) {
270 /* the first fully matching PCB */
271 if (prev != NULL) {
272 /* move the pcb to the front of udp_pcbs so that is
273 found faster next time */
274 prev->next = pcb->next;
275 pcb->next = udp_pcbs;
276 udp_pcbs = pcb;
277 } else {
278 UDP_STATS_INC(udp.cachehit);
279 }
280 break;
281 }
282 prev = pcb;
283 }
284 /* no fully matching pcb found? then look for an unconnected pcb */
285 if (pcb == NULL) {
286 pcb = uncon_pcb;
287 }
288 }
289
290 /* Check checksum if this is a match or if it was directed at us. */
291 if (pcb != NULL || ip_addr_cmp(&inp->ip_addr, &current_iphdr_dest)) {
292 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
293#if LWIP_UDPLITE
294 if (IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) {
295 /* Do the UDP Lite checksum */
296#if CHECKSUM_CHECK_UDP
297 u16_t chklen = ntohs(udphdr->len);
298 if (chklen < sizeof(struct udp_hdr)) {
299 if (chklen == 0) {
300 /* For UDP-Lite, checksum length of 0 means checksum
301 over the complete packet (See RFC 3828 chap. 3.1) */
302 chklen = p->tot_len;
303 } else {
304 /* At least the UDP-Lite header must be covered by the
305 checksum! (Again, see RFC 3828 chap. 3.1) */
306 UDP_STATS_INC(udp.chkerr);
307 UDP_STATS_INC(udp.drop);
308 snmp_inc_udpinerrors();
309 pbuf_free(p);
310 goto end;
311 }
312 }
313 if (inet_chksum_pseudo_partial(p, &current_iphdr_src, &current_iphdr_dest,
314 IP_PROTO_UDPLITE, p->tot_len, chklen) != 0) {
315 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
316 ("udp_input: UDP Lite datagram discarded due to failing checksum\n"));
317 UDP_STATS_INC(udp.chkerr);
318 UDP_STATS_INC(udp.drop);
319 snmp_inc_udpinerrors();
320 pbuf_free(p);
321 goto end;
322 }
323#endif /* CHECKSUM_CHECK_UDP */
324 } else
325#endif /* LWIP_UDPLITE */
326 {
327#if CHECKSUM_CHECK_UDP
328 if (udphdr->chksum != 0) {
329 if (inet_chksum_pseudo(p, ip_current_src_addr(), ip_current_dest_addr(),
330 IP_PROTO_UDP, p->tot_len) != 0) {
331 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
332 ("udp_input: UDP datagram discarded due to failing checksum\n"));
333 UDP_STATS_INC(udp.chkerr);
334 UDP_STATS_INC(udp.drop);
335 snmp_inc_udpinerrors();
336 pbuf_free(p);
337 goto end;
338 }
339 }
340#endif /* CHECKSUM_CHECK_UDP */
341 }
342 if(pbuf_header(p, -UDP_HLEN)) {
343 /* Can we cope with this failing? Just assert for now */
344 LWIP_ASSERT("pbuf_header failed\n", 0);
345 UDP_STATS_INC(udp.drop);
346 snmp_inc_udpinerrors();
347 pbuf_free(p);
348 goto end;
349 }
350 if (pcb != NULL) {
351 snmp_inc_udpindatagrams();
352#if SO_REUSE && SO_REUSE_RXTOALL
353 if ((broadcast || ip_addr_ismulticast(&current_iphdr_dest)) &&
354 ip_get_option(pcb, SOF_REUSEADDR)) {
355 /* pass broadcast- or multicast packets to all multicast pcbs
356 if SOF_REUSEADDR is set on the first match */
357 struct udp_pcb *mpcb;
358 u8_t p_header_changed = 0;
359 for (mpcb = udp_pcbs; mpcb != NULL; mpcb = mpcb->next) {
360 if (mpcb != pcb) {
361 /* compare PCB local addr+port to UDP destination addr+port */
362 if ((mpcb->local_port == dest) &&
363 ((!broadcast && ip_addr_isany(&mpcb->local_ip)) ||
364 ip_addr_cmp(&(mpcb->local_ip), &current_iphdr_dest) ||
365#if LWIP_IGMP
366 ip_addr_ismulticast(&current_iphdr_dest) ||
367#endif /* LWIP_IGMP */
368#if IP_SOF_BROADCAST_RECV
369 (broadcast && ip_get_option(mpcb, SOF_BROADCAST)))) {
370#else /* IP_SOF_BROADCAST_RECV */
371 (broadcast))) {
372#endif /* IP_SOF_BROADCAST_RECV */
373 /* pass a copy of the packet to all local matches */
374 if (mpcb->recv != NULL) {
375 struct pbuf *q;
376 /* for that, move payload to IP header again */
377 if (p_header_changed == 0) {
378 pbuf_header(p, (s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
379 p_header_changed = 1;
380 }
381 q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
382 if (q != NULL) {
383 err_t err = pbuf_copy(q, p);
384 if (err == ERR_OK) {
385 /* move payload to UDP data */
386 pbuf_header(q, -(s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
387 mpcb->recv(mpcb->recv_arg, mpcb, q, ip_current_src_addr(), src);
388 }
389 }
390 }
391 }
392 }
393 }
394 if (p_header_changed) {
395 /* and move payload to UDP data again */
396 pbuf_header(p, -(s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
397 }
398 }
399#endif /* SO_REUSE && SO_REUSE_RXTOALL */
400 /* callback */
401 if (pcb->recv != NULL) {
402 /* now the recv function is responsible for freeing p */
403 pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr(), src);
404 } else {
405 /* no recv function registered? then we have to free the pbuf! */
406 pbuf_free(p);
407 goto end;
408 }
409 } else {
410 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: not for us.\n"));
411
412#if LWIP_ICMP
413 /* No match was found, send ICMP destination port unreachable unless
414 destination address was broadcast/multicast. */
415 if (!broadcast &&
416 !ip_addr_ismulticast(&current_iphdr_dest)) {
417 /* move payload pointer back to ip header */
418 pbuf_header(p, (IPH_HL(iphdr) * 4) + UDP_HLEN);
419 LWIP_ASSERT("p->payload == iphdr", (p->payload == iphdr));
420 icmp_dest_unreach(p, ICMP_DUR_PORT);
421 }
422#endif /* LWIP_ICMP */
423 UDP_STATS_INC(udp.proterr);
424 UDP_STATS_INC(udp.drop);
425 snmp_inc_udpnoports();
426 pbuf_free(p);
427 }
428 } else {
429 pbuf_free(p);
430 }
431end:
432 PERF_STOP("udp_input");
433}
434
435/**
436 * Send data using UDP.
437 *
438 * @param pcb UDP PCB used to send the data.
439 * @param p chain of pbuf's to be sent.
440 *
441 * The datagram will be sent to the current remote_ip & remote_port
442 * stored in pcb. If the pcb is not bound to a port, it will
443 * automatically be bound to a random port.
444 *
445 * @return lwIP error code.
446 * - ERR_OK. Successful. No error occured.
447 * - ERR_MEM. Out of memory.
448 * - ERR_RTE. Could not find route to destination address.
449 * - More errors could be returned by lower protocol layers.
450 *
451 * @see udp_disconnect() udp_sendto()
452 */
453err_t
454udp_send(struct udp_pcb *pcb, struct pbuf *p)
455{
456 /* send to the packet using remote ip and port stored in the pcb */
457 return udp_sendto(pcb, p, &pcb->remote_ip, pcb->remote_port);
458}
459
460#if LWIP_CHECKSUM_ON_COPY
461/** Same as udp_send() but with checksum
462 */
463err_t
464udp_send_chksum(struct udp_pcb *pcb, struct pbuf *p,
465 u8_t have_chksum, u16_t chksum)
466{
467 /* send to the packet using remote ip and port stored in the pcb */
468 return udp_sendto_chksum(pcb, p, &pcb->remote_ip, pcb->remote_port,
469 have_chksum, chksum);
470}
471#endif /* LWIP_CHECKSUM_ON_COPY */
472
473/**
474 * Send data to a specified address using UDP.
475 *
476 * @param pcb UDP PCB used to send the data.
477 * @param p chain of pbuf's to be sent.
478 * @param dst_ip Destination IP address.
479 * @param dst_port Destination UDP port.
480 *
481 * dst_ip & dst_port are expected to be in the same byte order as in the pcb.
482 *
483 * If the PCB already has a remote address association, it will
484 * be restored after the data is sent.
485 *
486 * @return lwIP error code (@see udp_send for possible error codes)
487 *
488 * @see udp_disconnect() udp_send()
489 */
490err_t
491udp_sendto(struct udp_pcb *pcb, struct pbuf *p,
492 ip_addr_t *dst_ip, u16_t dst_port)
493{
494#if LWIP_CHECKSUM_ON_COPY
495 return udp_sendto_chksum(pcb, p, dst_ip, dst_port, 0, 0);
496}
497
498/** Same as udp_sendto(), but with checksum */
499err_t
500udp_sendto_chksum(struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *dst_ip,
501 u16_t dst_port, u8_t have_chksum, u16_t chksum)
502{
503#endif /* LWIP_CHECKSUM_ON_COPY */
504 struct netif *netif;
505
506 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send\n"));
507
508 /* find the outgoing network interface for this packet */
509#if LWIP_IGMP
510 netif = ip_route((ip_addr_ismulticast(dst_ip))?(&(pcb->multicast_ip)):(dst_ip));
511#else
512 netif = ip_route(dst_ip);
513#endif /* LWIP_IGMP */
514
515 /* no outgoing network interface could be found? */
516 if (netif == NULL) {
517 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
518 ip4_addr1_16(dst_ip), ip4_addr2_16(dst_ip), ip4_addr3_16(dst_ip), ip4_addr4_16(dst_ip)));
519 UDP_STATS_INC(udp.rterr);
520 return ERR_RTE;
521 }
522#if LWIP_CHECKSUM_ON_COPY
523 return udp_sendto_if_chksum(pcb, p, dst_ip, dst_port, netif, have_chksum, chksum);
524#else /* LWIP_CHECKSUM_ON_COPY */
525 return udp_sendto_if(pcb, p, dst_ip, dst_port, netif);
526#endif /* LWIP_CHECKSUM_ON_COPY */
527}
528
529/**
530 * Send data to a specified address using UDP.
531 * The netif used for sending can be specified.
532 *
533 * This function exists mainly for DHCP, to be able to send UDP packets
534 * on a netif that is still down.
535 *
536 * @param pcb UDP PCB used to send the data.
537 * @param p chain of pbuf's to be sent.
538 * @param dst_ip Destination IP address.
539 * @param dst_port Destination UDP port.
540 * @param netif the netif used for sending.
541 *
542 * dst_ip & dst_port are expected to be in the same byte order as in the pcb.
543 *
544 * @return lwIP error code (@see udp_send for possible error codes)
545 *
546 * @see udp_disconnect() udp_send()
547 */
548err_t
549udp_sendto_if(struct udp_pcb *pcb, struct pbuf *p,
550 ip_addr_t *dst_ip, u16_t dst_port, struct netif *netif)
551{
552#if LWIP_CHECKSUM_ON_COPY
553 return udp_sendto_if_chksum(pcb, p, dst_ip, dst_port, netif, 0, 0);
554}
555
556/** Same as udp_sendto_if(), but with checksum */
557err_t
558udp_sendto_if_chksum(struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *dst_ip,
559 u16_t dst_port, struct netif *netif, u8_t have_chksum,
560 u16_t chksum)
561{
562#endif /* LWIP_CHECKSUM_ON_COPY */
563 struct udp_hdr *udphdr;
564 ip_addr_t *src_ip;
565 err_t err;
566 struct pbuf *q; /* q will be sent down the stack */
567
568#if IP_SOF_BROADCAST
569 /* broadcast filter? */
570 if (!ip_get_option(pcb, SOF_BROADCAST) && ip_addr_isbroadcast(dst_ip, netif)) {
571 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
572 ("udp_sendto_if: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
573 return ERR_VAL;
574 }
575#endif /* IP_SOF_BROADCAST */
576
577 /* if the PCB is not yet bound to a port, bind it here */
578 if (pcb->local_port == 0) {
579 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send: not yet bound to a port, binding now\n"));
580 err = udp_bind(pcb, &pcb->local_ip, pcb->local_port);
581 if (err != ERR_OK) {
582 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: forced port bind failed\n"));
583 return err;
584 }
585 }
586
587 /* not enough space to add an UDP header to first pbuf in given p chain? */
588 if (pbuf_header(p, UDP_HLEN)) {
589 /* allocate header in a separate new pbuf */
590 q = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM);
591 /* new header pbuf could not be allocated? */
592 if (q == NULL) {
593 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: could not allocate header\n"));
594 return ERR_MEM;
595 }
596 if (p->tot_len != 0) {
597 /* chain header q in front of given pbuf p (only if p contains data) */
598 pbuf_chain(q, p);
599 }
600 /* first pbuf q points to header pbuf */
601 LWIP_DEBUGF(UDP_DEBUG,
602 ("udp_send: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
603 } else {
604 /* adding space for header within p succeeded */
605 /* first pbuf q equals given pbuf */
606 q = p;
607 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: added header in given pbuf %p\n", (void *)p));
608 }
609 LWIP_ASSERT("check that first pbuf can hold struct udp_hdr",
610 (q->len >= sizeof(struct udp_hdr)));
611 /* q now represents the packet to be sent */
612 udphdr = (struct udp_hdr *)q->payload;
613 udphdr->src = htons(pcb->local_port);
614 udphdr->dest = htons(dst_port);
615 /* in UDP, 0 checksum means 'no checksum' */
616 udphdr->chksum = 0x0000;
617
618 /* Multicast Loop? */
619#if LWIP_IGMP
620 if (ip_addr_ismulticast(dst_ip) && ((pcb->flags & UDP_FLAGS_MULTICAST_LOOP) != 0)) {
621 q->flags |= PBUF_FLAG_MCASTLOOP;
622 }
623#endif /* LWIP_IGMP */
624
625
626 /* PCB local address is IP_ANY_ADDR? */
627 if (ip_addr_isany(&pcb->local_ip)) {
628 /* use outgoing network interface IP address as source address */
629 src_ip = &(netif->ip_addr);
630 } else {
631 /* check if UDP PCB local IP address is correct
632 * this could be an old address if netif->ip_addr has changed */
633 if (!ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {
634 /* local_ip doesn't match, drop the packet */
635 if (q != p) {
636 /* free the header pbuf */
637 pbuf_free(q);
638 q = NULL;
639 /* p is still referenced by the caller, and will live on */
640 }
641 return ERR_VAL;
642 }
643 /* use UDP PCB local IP address as source address */
644 src_ip = &(pcb->local_ip);
645 }
646
647 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %"U16_F"\n", q->tot_len));
648
649#if LWIP_UDPLITE
650 /* UDP Lite protocol? */
651 if (pcb->flags & UDP_FLAGS_UDPLITE) {
652 u16_t chklen, chklen_hdr;
653 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE packet length %"U16_F"\n", q->tot_len));
654 /* set UDP message length in UDP header */
655 chklen_hdr = chklen = pcb->chksum_len_tx;
656 if ((chklen < sizeof(struct udp_hdr)) || (chklen > q->tot_len)) {
657 if (chklen != 0) {
658 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE pcb->chksum_len is illegal: %"U16_F"\n", chklen));
659 }
660 /* For UDP-Lite, checksum length of 0 means checksum
661 over the complete packet. (See RFC 3828 chap. 3.1)
662 At least the UDP-Lite header must be covered by the
663 checksum, therefore, if chksum_len has an illegal
664 value, we generate the checksum over the complete
665 packet to be safe. */
666 chklen_hdr = 0;
667 chklen = q->tot_len;
668 }
669 udphdr->len = htons(chklen_hdr);
670 /* calculate checksum */
671#if CHECKSUM_GEN_UDP
672 udphdr->chksum = inet_chksum_pseudo_partial(q, src_ip, dst_ip,
673 IP_PROTO_UDPLITE, q->tot_len,
674#if !LWIP_CHECKSUM_ON_COPY
675 chklen);
676#else /* !LWIP_CHECKSUM_ON_COPY */
677 (have_chksum ? UDP_HLEN : chklen));
678 if (have_chksum) {
679 u32_t acc;
680 acc = udphdr->chksum + (u16_t)~(chksum);
681 udphdr->chksum = FOLD_U32T(acc);
682 }
683#endif /* !LWIP_CHECKSUM_ON_COPY */
684
685 /* chksum zero must become 0xffff, as zero means 'no checksum' */
686 if (udphdr->chksum == 0x0000) {
687 udphdr->chksum = 0xffff;
688 }
689#endif /* CHECKSUM_GEN_UDP */
690 /* output to IP */
691 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDPLITE,)\n"));
692 NETIF_SET_HWADDRHINT(netif, &pcb->addr_hint);
693 err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDPLITE, netif);
694 NETIF_SET_HWADDRHINT(netif, NULL);
695 } else
696#endif /* LWIP_UDPLITE */
697 { /* UDP */
698 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP packet length %"U16_F"\n", q->tot_len));
699 udphdr->len = htons(q->tot_len);
700 /* calculate checksum */
701#if CHECKSUM_GEN_UDP
702 if ((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) {
703 u16_t udpchksum;
704#if LWIP_CHECKSUM_ON_COPY
705 if (have_chksum) {
706 u32_t acc;
707 udpchksum = inet_chksum_pseudo_partial(q, src_ip, dst_ip, IP_PROTO_UDP,
708 q->tot_len, UDP_HLEN);
709 acc = udpchksum + (u16_t)~(chksum);
710 udpchksum = FOLD_U32T(acc);
711 } else
712#endif /* LWIP_CHECKSUM_ON_COPY */
713 {
714 udpchksum = inet_chksum_pseudo(q, src_ip, dst_ip, IP_PROTO_UDP, q->tot_len);
715 }
716
717 /* chksum zero must become 0xffff, as zero means 'no checksum' */
718 if (udpchksum == 0x0000) {
719 udpchksum = 0xffff;
720 }
721 udphdr->chksum = udpchksum;
722 }
723#endif /* CHECKSUM_GEN_UDP */
724 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum 0x%04"X16_F"\n", udphdr->chksum));
725 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDP,)\n"));
726 /* output to IP */
727 NETIF_SET_HWADDRHINT(netif, &pcb->addr_hint);
728 err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDP, netif);
729 NETIF_SET_HWADDRHINT(netif, NULL);
730 }
731 /* TODO: must this be increased even if error occured? */
732 snmp_inc_udpoutdatagrams();
733
734 /* did we chain a separate header pbuf earlier? */
735 if (q != p) {
736 /* free the header pbuf */
737 pbuf_free(q);
738 q = NULL;
739 /* p is still referenced by the caller, and will live on */
740 }
741
742 UDP_STATS_INC(udp.xmit);
743 return err;
744}
745
746/**
747 * Bind an UDP PCB.
748 *
749 * @param pcb UDP PCB to be bound with a local address ipaddr and port.
750 * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to
751 * bind to all local interfaces.
752 * @param port local UDP port to bind with. Use 0 to automatically bind
753 * to a random port between UDP_LOCAL_PORT_RANGE_START and
754 * UDP_LOCAL_PORT_RANGE_END.
755 *
756 * ipaddr & port are expected to be in the same byte order as in the pcb.
757 *
758 * @return lwIP error code.
759 * - ERR_OK. Successful. No error occured.
760 * - ERR_USE. The specified ipaddr and port are already bound to by
761 * another UDP PCB.
762 *
763 * @see udp_disconnect()
764 */
765err_t
766udp_bind(struct udp_pcb *pcb, ip_addr_t *ipaddr, u16_t port)
767{
768 struct udp_pcb *ipcb;
769 u8_t rebind;
770
771 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_bind(ipaddr = "));
772 ip_addr_debug_print(UDP_DEBUG, ipaddr);
773 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, (", port = %"U16_F")\n", port));
774
775 rebind = 0;
776 /* Check for double bind and rebind of the same pcb */
777 for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
778 /* is this UDP PCB already on active list? */
779 if (pcb == ipcb) {
780 /* pcb may occur at most once in active list */
781 LWIP_ASSERT("rebind == 0", rebind == 0);
782 /* pcb already in list, just rebind */
783 rebind = 1;
784 }
785
786 /* By default, we don't allow to bind to a port that any other udp
787 PCB is alread bound to, unless *all* PCBs with that port have tha
788 REUSEADDR flag set. */
789#if SO_REUSE
790 else if (!ip_get_option(pcb, SOF_REUSEADDR) &&
791 !ip_get_option(ipcb, SOF_REUSEADDR)) {
792#else /* SO_REUSE */
793 /* port matches that of PCB in list and REUSEADDR not set -> reject */
794 else {
795#endif /* SO_REUSE */
796 if ((ipcb->local_port == port) &&
797 /* IP address matches, or one is IP_ADDR_ANY? */
798 (ip_addr_isany(&(ipcb->local_ip)) ||
799 ip_addr_isany(ipaddr) ||
800 ip_addr_cmp(&(ipcb->local_ip), ipaddr))) {
801 /* other PCB already binds to this local IP and port */
802 LWIP_DEBUGF(UDP_DEBUG,
803 ("udp_bind: local port %"U16_F" already bound by another pcb\n", port));
804 return ERR_USE;
805 }
806 }
807 }
808
809 ip_addr_set(&pcb->local_ip, ipaddr);
810
811 /* no port specified? */
812 if (port == 0) {
813 port = udp_new_port();
814 if (port == 0) {
815 /* no more ports available in local range */
816 LWIP_DEBUGF(UDP_DEBUG, ("udp_bind: out of free UDP ports\n"));
817 return ERR_USE;
818 }
819 }
820 pcb->local_port = port;
821 snmp_insert_udpidx_tree(pcb);
822 /* pcb not active yet? */
823 if (rebind == 0) {
824 /* place the PCB on the active list if not already there */
825 pcb->next = udp_pcbs;
826 udp_pcbs = pcb;
827 }
828 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
829 ("udp_bind: bound to %"U16_F".%"U16_F".%"U16_F".%"U16_F", port %"U16_F"\n",
830 ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
831 ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip),
832 pcb->local_port));
833 return ERR_OK;
834}
835/**
836 * Connect an UDP PCB.
837 *
838 * This will associate the UDP PCB with the remote address.
839 *
840 * @param pcb UDP PCB to be connected with remote address ipaddr and port.
841 * @param ipaddr remote IP address to connect with.
842 * @param port remote UDP port to connect with.
843 *
844 * @return lwIP error code
845 *
846 * ipaddr & port are expected to be in the same byte order as in the pcb.
847 *
848 * The udp pcb is bound to a random local port if not already bound.
849 *
850 * @see udp_disconnect()
851 */
852err_t
853udp_connect(struct udp_pcb *pcb, ip_addr_t *ipaddr, u16_t port)
854{
855 struct udp_pcb *ipcb;
856
857 if (pcb->local_port == 0) {
858 err_t err = udp_bind(pcb, &pcb->local_ip, pcb->local_port);
859 if (err != ERR_OK) {
860 return err;
861 }
862 }
863
864 ip_addr_set(&pcb->remote_ip, ipaddr);
865 pcb->remote_port = port;
866 pcb->flags |= UDP_FLAGS_CONNECTED;
867/** TODO: this functionality belongs in upper layers */
868#ifdef LWIP_UDP_TODO
869 /* Nail down local IP for netconn_addr()/getsockname() */
870 if (ip_addr_isany(&pcb->local_ip) && !ip_addr_isany(&pcb->remote_ip)) {
871 struct netif *netif;
872
873 if ((netif = ip_route(&(pcb->remote_ip))) == NULL) {
874 LWIP_DEBUGF(UDP_DEBUG, ("udp_connect: No route to 0x%lx\n", pcb->remote_ip.addr));
875 UDP_STATS_INC(udp.rterr);
876 return ERR_RTE;
877 }
878 /** TODO: this will bind the udp pcb locally, to the interface which
879 is used to route output packets to the remote address. However, we
880 might want to accept incoming packets on any interface! */
881 pcb->local_ip = netif->ip_addr;
882 } else if (ip_addr_isany(&pcb->remote_ip)) {
883 pcb->local_ip.addr = 0;
884 }
885#endif
886 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
887 ("udp_connect: connected to %"U16_F".%"U16_F".%"U16_F".%"U16_F",port %"U16_F"\n",
888 ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
889 ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip),
890 pcb->local_port));
891
892 /* Insert UDP PCB into the list of active UDP PCBs. */
893 for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
894 if (pcb == ipcb) {
895 /* already on the list, just return */
896 return ERR_OK;
897 }
898 }
899 /* PCB not yet on the list, add PCB now */
900 pcb->next = udp_pcbs;
901 udp_pcbs = pcb;
902 return ERR_OK;
903}
904
905/**
906 * Disconnect a UDP PCB
907 *
908 * @param pcb the udp pcb to disconnect.
909 */
910void
911udp_disconnect(struct udp_pcb *pcb)
912{
913 /* reset remote address association */
914 ip_addr_set_any(&pcb->remote_ip);
915 pcb->remote_port = 0;
916 /* mark PCB as unconnected */
917 pcb->flags &= ~UDP_FLAGS_CONNECTED;
918}
919
920/**
921 * Set a receive callback for a UDP PCB
922 *
923 * This callback will be called when receiving a datagram for the pcb.
924 *
925 * @param pcb the pcb for wich to set the recv callback
926 * @param recv function pointer of the callback function
927 * @param recv_arg additional argument to pass to the callback function
928 */
929void
930udp_recv(struct udp_pcb *pcb, udp_recv_fn recv, void *recv_arg)
931{
932 /* remember recv() callback and user data */
933 pcb->recv = recv;
934 pcb->recv_arg = recv_arg;
935}
936
937/**
938 * Remove an UDP PCB.
939 *
940 * @param pcb UDP PCB to be removed. The PCB is removed from the list of
941 * UDP PCB's and the data structure is freed from memory.
942 *
943 * @see udp_new()
944 */
945void
946udp_remove(struct udp_pcb *pcb)
947{
948 struct udp_pcb *pcb2;
949
950 snmp_delete_udpidx_tree(pcb);
951 /* pcb to be removed is first in list? */
952 if (udp_pcbs == pcb) {
953 /* make list start at 2nd pcb */
954 udp_pcbs = udp_pcbs->next;
955 /* pcb not 1st in list */
956 } else {
957 for (pcb2 = udp_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
958 /* find pcb in udp_pcbs list */
959 if (pcb2->next != NULL && pcb2->next == pcb) {
960 /* remove pcb from list */
961 pcb2->next = pcb->next;
962 }
963 }
964 }
965 memp_free(MEMP_UDP_PCB, pcb);
966}
967
968/**
969 * Create a UDP PCB.
970 *
971 * @return The UDP PCB which was created. NULL if the PCB data structure
972 * could not be allocated.
973 *
974 * @see udp_remove()
975 */
976struct udp_pcb *
977udp_new(void)
978{
979 struct udp_pcb *pcb;
980 pcb = (struct udp_pcb *)memp_malloc(MEMP_UDP_PCB);
981 /* could allocate UDP PCB? */
982 if (pcb != NULL) {
983 /* UDP Lite: by initializing to all zeroes, chksum_len is set to 0
984 * which means checksum is generated over the whole datagram per default
985 * (recommended as default by RFC 3828). */
986 /* initialize PCB to all zeroes */
987 memset(pcb, 0, sizeof(struct udp_pcb));
988 pcb->ttl = UDP_TTL;
989 }
990 return pcb;
991}
992
993#if UDP_DEBUG
994/**
995 * Print UDP header information for debug purposes.
996 *
997 * @param udphdr pointer to the udp header in memory.
998 */
999void
1000udp_debug_print(struct udp_hdr *udphdr)
1001{
1002 LWIP_DEBUGF(UDP_DEBUG, ("UDP header:\n"));
1003 LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
1004 LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | %5"U16_F" | (src port, dest port)\n",
1005 ntohs(udphdr->src), ntohs(udphdr->dest)));
1006 LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
1007 LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | 0x%04"X16_F" | (len, chksum)\n",
1008 ntohs(udphdr->len), ntohs(udphdr->chksum)));
1009 LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
1010}
1011#endif /* UDP_DEBUG */
1012
1013#endif /* LWIP_UDP */
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