1 /**
2 * @file
3 * User Datagram Protocol module\n
4 * The code for the User Datagram Protocol UDP & UDPLite (RFC 3828).\n
5 * See also @ref udp_raw
6 *
7 * @defgroup udp_raw UDP
8 * @ingroup callbackstyle_api
9 * User Datagram Protocol module\n
10 * @see @ref api
11 */
12
13 /*
14 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without modification,
18 * are permitted provided that the following conditions are met:
19 *
20 * 1. Redistributions of source code must retain the above copyright notice,
21 * this list of conditions and the following disclaimer.
22 * 2. Redistributions in binary form must reproduce the above copyright notice,
23 * this list of conditions and the following disclaimer in the documentation
24 * and/or other materials provided with the distribution.
25 * 3. The name of the author may not be used to endorse or promote products
26 * derived from this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
29 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
30 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
31 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
32 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
33 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
36 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
37 * OF SUCH DAMAGE.
38 *
39 * This file is part of the lwIP TCP/IP stack.
40 *
41 * Author: Adam Dunkels <adam@sics.se>
42 *
43 */
44
45 /* @todo Check the use of '(struct udp_pcb).chksum_len_rx'!
46 */
47
48 #include "lwip/opt.h"
49
50 #if LWIP_UDP /* don't build if not configured for use in lwipopts.h */
51
52 #include "lwip/udp.h"
53 #include "lwip/def.h"
54 #include "lwip/sys.h"
55 #include "lwip/memp.h"
56 #include "lwip/inet_chksum.h"
57 #include "lwip/ip_addr.h"
58 #include "lwip/ip6.h"
59 #include "lwip/ip6_addr.h"
60 #include "lwip/netif.h"
61 #include "lwip/icmp.h"
62 #include "lwip/icmp6.h"
63 #include "lwip/stats.h"
64 #include "lwip/snmp.h"
65 #include "lwip/dhcp.h"
66
67 #include <string.h>
68
69 #if (LWIP_MPL || LWIP_MPL_IPV4)
70 #include "mcast6.h"
71 #endif /* LWIP_MPL || LWIP_MPL_IPV4 */
72
73 #if (LWIP_IPV6 && LWIP_MPL)
74 #ifndef MCAST6_MPL_OUT
75 #define MCAST6_MPL_OUT mcast6_esmrf_icmp_out
76 #endif /* MCAST6_MPL_OUT */
77 #endif /* LWIP_IPV6 && LWIP_MPL */
78
79 #if LWIP_MPL_IPV4
80 #ifndef LWIP_MPL_IPV4_OUT
81 #define LWIP_MPL_IPV4_OUT mcast6_ipv4_out
82 #endif /* LWIP_MPL_IPV4_OUT */
83 #endif /* LWIP_MPL_IPV4 */
84
85 #ifndef UDP_LOCAL_PORT_RANGE_START
86 /* From http://www.iana.org/assignments/port-numbers:
87 "The Dynamic and/or Private Ports are those from 49152 through 65535" */
88 #define UDP_LOCAL_PORT_RANGE_START 0xc000
89 #define UDP_LOCAL_PORT_RANGE_END 0xffff
90 #endif
91
92 /* last local UDP port */
93 static u16_t udp_port = UDP_LOCAL_PORT_RANGE_START;
94
95 /* The list of UDP PCBs */
96 /* exported in udp.h (was static) */
97 struct udp_pcb *udp_pcbs;
98
99 /**
100 * Initialize this module.
101 */
102 void
udp_init(void)103 udp_init(void)
104 {
105 }
106
107 static void
udp_generate_port_candidate(void)108 udp_generate_port_candidate(void)
109 {
110 #ifdef LWIP_RAND
111 udp_port = (u16_t)(UDP_LOCAL_PORT_RANGE_START +
112 (LWIP_RAND() % (UDP_LOCAL_PORT_RANGE_END - UDP_LOCAL_PORT_RANGE_START + 1)));
113 #else
114 if (udp_port++ == UDP_LOCAL_PORT_RANGE_END) {
115 udp_port = UDP_LOCAL_PORT_RANGE_START;
116 }
117 #endif
118 }
119
120 /**
121 * Allocate a new local UDP port.
122 *
123 * @return a new (free) local UDP port number
124 */
125 static u16_t
udp_new_port(void)126 udp_new_port(void)
127 {
128 u16_t n = 0;
129 struct udp_pcb *pcb;
130
131 again:
132 udp_generate_port_candidate();
133 /* Check all PCBs. */
134 for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
135 if (pcb->local_port == udp_port) {
136 if (++n > (UDP_LOCAL_PORT_RANGE_END - UDP_LOCAL_PORT_RANGE_START)) {
137 return 0;
138 }
139 goto again;
140 }
141 }
142 return udp_port;
143 }
144
145 /** Common code to see if the current input packet matches the pcb
146 * (current input packet is accessed via ip(4/6)_current_* macros)
147 *
148 * @param pcb pcb to check
149 * @param inp network interface on which the datagram was received (only used for IPv4)
150 * @param broadcast 1 if his is an IPv4 broadcast (global or subnet-only), 0 otherwise (only used for IPv4)
151 * @return 1 on match, 0 otherwise
152 */
153 static u8_t
udp_input_local_match(struct udp_pcb * pcb,struct netif * inp,u8_t broadcast)154 udp_input_local_match(struct udp_pcb *pcb, struct netif *inp, u8_t broadcast)
155 {
156 LWIP_UNUSED_ARG(inp); /* in IPv6 only case */
157 LWIP_UNUSED_ARG(broadcast); /* in IPv6 only case */
158
159 LWIP_ASSERT("udp_input_local_match: invalid pcb", pcb != NULL);
160 LWIP_ASSERT("udp_input_local_match: invalid netif", inp != NULL);
161
162 /* check if PCB is bound to specific netif */
163 if ((pcb->netif_idx != NETIF_NO_INDEX) &&
164 (pcb->netif_idx != netif_get_index(ip_data.current_input_netif))) {
165 return 0;
166 }
167
168 /* Dual-stack: PCBs listening to any IP type also listen to any IP address */
169 if (IP_IS_ANY_TYPE_VAL(pcb->local_ip)) {
170 #if LWIP_IPV4 && IP_SOF_BROADCAST_RECV
171 if ((broadcast != 0) && !ip_get_option(pcb, SOF_BROADCAST)) {
172 return 0;
173 }
174 #endif /* LWIP_IPV4 && IP_SOF_BROADCAST_RECV */
175 return 1;
176 }
177
178 /* Only need to check PCB if incoming IP version matches PCB IP version */
179 if (IP_ADDR_PCB_VERSION_MATCH_EXACT(pcb, ip_current_dest_addr())) {
180 #if LWIP_IPV4
181 /* Special case: IPv4 broadcast: all or broadcasts in my subnet
182 * Note: broadcast variable can only be 1 if it is an IPv4 broadcast */
183 if (broadcast != 0) {
184 #if IP_SOF_BROADCAST_RECV
185 if (ip_get_option(pcb, SOF_BROADCAST))
186 #endif /* IP_SOF_BROADCAST_RECV */
187 {
188 if (ip4_addr_isany(ip_2_ip4(&pcb->local_ip)) ||
189 ((ip4_current_dest_addr()->addr == IPADDR_BROADCAST)) ||
190 ip4_addr_netcmp(ip_2_ip4(&pcb->local_ip), ip4_current_dest_addr(), netif_ip4_netmask(inp))) {
191 return 1;
192 }
193 }
194 } else
195 #endif /* LWIP_IPV4 */
196 /* Handle IPv4 and IPv6: all or exact match */
197 if (ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&pcb->local_ip, ip_current_dest_addr())) {
198 return 1;
199 }
200 }
201
202 return 0;
203 }
204
205 /**
206 * Process an incoming UDP datagram.
207 *
208 * Given an incoming UDP datagram (as a chain of pbufs) this function
209 * finds a corresponding UDP PCB and hands over the pbuf to the pcbs
210 * recv function. If no pcb is found or the datagram is incorrect, the
211 * pbuf is freed.
212 *
213 * @param p pbuf to be demultiplexed to a UDP PCB (p->payload pointing to the UDP header)
214 * @param inp network interface on which the datagram was received.
215 *
216 */
217 void
udp_input(struct pbuf * p,struct netif * inp)218 udp_input(struct pbuf *p, struct netif *inp)
219 {
220 struct udp_hdr *udphdr;
221 struct udp_pcb *pcb, *prev;
222 struct udp_pcb *low_score_pcb = NULL;
223 struct udp_pcb *high_score_pcb = NULL;
224 u16_t src, dest;
225 u8_t broadcast;
226 u8_t for_us = 0;
227
228 LWIP_UNUSED_ARG(inp);
229
230 LWIP_ASSERT_CORE_LOCKED();
231
232 LWIP_ASSERT("udp_input: invalid pbuf", p != NULL);
233 LWIP_ASSERT("udp_input: invalid netif", inp != NULL);
234
235 PERF_START;
236
237 UDP_STATS_INC(udp.recv);
238
239 /* Check minimum length (UDP header) */
240 if (p->len < UDP_HLEN) {
241 /* drop short packets */
242 LWIP_DEBUGF(UDP_DEBUG,
243 ("udp_input: short UDP datagram (%"U16_F" bytes) discarded\n", p->tot_len));
244 UDP_STATS_INC(udp.lenerr);
245 UDP_STATS_INC(udp.drop);
246 MIB2_STATS_INC(mib2.udpinerrors);
247 pbuf_free(p);
248 goto end;
249 }
250
251 udphdr = (struct udp_hdr *)p->payload;
252
253 /* is broadcast packet ? */
254 broadcast = ip_addr_isbroadcast(ip_current_dest_addr(), ip_current_netif());
255
256 LWIP_DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %"U16_F"\n", p->tot_len));
257
258 /* convert src and dest ports to host byte order */
259 src = lwip_ntohs(udphdr->src);
260 dest = lwip_ntohs(udphdr->dest);
261
262 udp_debug_print(udphdr);
263
264 /* print the UDP source and destination */
265 LWIP_DEBUGF(UDP_DEBUG, ("udp ("));
266 ip_addr_debug_print_val(UDP_DEBUG, *ip_current_dest_addr());
267 LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", lwip_ntohs(udphdr->dest)));
268 ip_addr_debug_print_val(UDP_DEBUG, *ip_current_src_addr());
269 LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F")\n", lwip_ntohs(udphdr->src)));
270
271 pcb = NULL;
272 prev = NULL;
273 /* Iterate through the UDP pcb list for a matching pcb.
274 * 'Perfect match' pcbs (connected to the remote port & ip address) are
275 * preferred. If no perfect match is found, the first unconnected pcb that
276 * matches the local port and ip address gets the datagram. */
277 for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
278 /* print the PCB local and remote address */
279 LWIP_DEBUGF(UDP_DEBUG, ("pcb ("));
280 ip_addr_debug_print_val(UDP_DEBUG, pcb->local_ip);
281 LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F") <-- (", pcb->local_port));
282 ip_addr_debug_print_val(UDP_DEBUG, pcb->remote_ip);
283 LWIP_DEBUGF(UDP_DEBUG, (", %"U16_F")\n", pcb->remote_port));
284
285 /* compare PCB local addr+port to UDP destination addr+port */
286 if ((pcb->local_port == dest) &&
287 (udp_input_local_match(pcb, inp, broadcast) != 0)) {
288 /* compare PCB remote addr+port to UDP source addr+port */
289 if ((pcb->remote_port == src) &&
290 (ip_addr_isany_val(pcb->remote_ip) ||
291 ip_addr_cmp(&pcb->remote_ip, ip_current_src_addr()))) {
292 /* the first fully matching PCB */
293 if (prev != NULL) {
294 /* move the pcb to the front of udp_pcbs so that is
295 found faster next time */
296 prev->next = pcb->next;
297 pcb->next = udp_pcbs;
298 udp_pcbs = pcb;
299 } else {
300 UDP_STATS_INC(udp.cachehit);
301 }
302 break;
303 }
304
305 if (high_score_pcb == NULL && !ip_addr_isany(&pcb->local_ip)) {
306 high_score_pcb = pcb;
307 } else if (low_score_pcb == NULL) {
308 /* the any addr matching PCB */
309 low_score_pcb = pcb;
310 }
311 }
312
313 prev = pcb;
314 }
315 /* no connected matching pcb found? then look for high score pcb */
316 if (pcb == NULL) {
317 pcb = high_score_pcb;
318 }
319
320 /* no matching pcb found? then look for low score pcb */
321 if (pcb == NULL) {
322 pcb = low_score_pcb;
323 }
324
325 /* Check checksum if this is a match or if it was directed at us. */
326 if (pcb != NULL) {
327 for_us = 1;
328 } else {
329 #if LWIP_IPV6
330 if (ip_current_is_v6()) {
331 for_us = netif_get_ip6_addr_match(inp, ip6_current_dest_addr()) >= 0;
332 }
333 #endif /* LWIP_IPV6 */
334 #if LWIP_IPV4
335 if (!ip_current_is_v6()) {
336 for_us = ip4_addr_cmp(netif_ip4_addr(inp), ip4_current_dest_addr());
337 }
338 #endif /* LWIP_IPV4 */
339 }
340
341 if (for_us) {
342 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
343 #if CHECKSUM_CHECK_UDP
344 IF__NETIF_CHECKSUM_ENABLED(inp, NETIF_CHECKSUM_CHECK_UDP) {
345 #if LWIP_UDPLITE
346 if (ip_current_header_proto() == IP_PROTO_UDPLITE) {
347 /* Do the UDP Lite checksum */
348 u16_t chklen = lwip_ntohs(udphdr->len);
349 if (chklen < sizeof(struct udp_hdr)) {
350 if (chklen == 0) {
351 /* For UDP-Lite, checksum length of 0 means checksum
352 over the complete packet (See RFC 3828 chap. 3.1) */
353 chklen = p->tot_len;
354 } else {
355 /* At least the UDP-Lite header must be covered by the
356 checksum! (Again, see RFC 3828 chap. 3.1) */
357 goto chkerr;
358 }
359 }
360 if (ip_chksum_pseudo_partial(p, IP_PROTO_UDPLITE,
361 p->tot_len, chklen,
362 ip_current_src_addr(), ip_current_dest_addr()) != 0) {
363 goto chkerr;
364 }
365 } else
366 #endif /* LWIP_UDPLITE */
367 {
368 if (udphdr->chksum != 0) {
369 if (ip_chksum_pseudo(p, IP_PROTO_UDP, p->tot_len,
370 ip_current_src_addr(),
371 ip_current_dest_addr()) != 0) {
372 goto chkerr;
373 }
374 }
375 }
376 }
377 #endif /* CHECKSUM_CHECK_UDP */
378 if (pbuf_remove_header(p, UDP_HLEN)) {
379 /* Can we cope with this failing? Just assert for now */
380 LWIP_ASSERT("pbuf_remove_header failed\n", 0);
381 UDP_STATS_INC(udp.drop);
382 MIB2_STATS_INC(mib2.udpinerrors);
383 pbuf_free(p);
384 goto end;
385 }
386
387 if (pcb != NULL) {
388 MIB2_STATS_INC(mib2.udpindatagrams);
389 #if SO_REUSE && SO_REUSE_RXTOALL
390 if (ip_get_option(pcb, SOF_REUSEADDR) &&
391 (broadcast || ip_addr_ismulticast(ip_current_dest_addr()))) {
392 /* pass broadcast- or multicast packets to all multicast pcbs
393 if SOF_REUSEADDR is set on the first match */
394 struct udp_pcb *mpcb;
395 for (mpcb = udp_pcbs; mpcb != NULL; mpcb = mpcb->next) {
396 if (mpcb != pcb) {
397 /* compare PCB local addr+port to UDP destination addr+port */
398 if ((mpcb->local_port == dest) &&
399 (udp_input_local_match(mpcb, inp, broadcast) != 0)) {
400 /* pass a copy of the packet to all local matches */
401 if (mpcb->recv != NULL) {
402 struct pbuf *q;
403 q = pbuf_clone(PBUF_RAW, PBUF_RAM, p);
404 if (q != NULL) {
405 mpcb->recv(mpcb->recv_arg, mpcb, q, ip_current_src_addr(), src);
406 }
407 }
408 }
409 }
410 }
411 }
412 #endif /* SO_REUSE && SO_REUSE_RXTOALL */
413 /* callback */
414 if (pcb->recv != NULL) {
415 /* now the recv function is responsible for freeing p */
416 pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr(), src);
417 } else {
418 /* no recv function registered? then we have to free the pbuf! */
419 pbuf_free(p);
420 goto end;
421 }
422 } else {
423 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: not for us.\n"));
424
425 #if LWIP_ICMP || LWIP_ICMP6
426 /* No match was found, send ICMP destination port unreachable unless
427 destination address was broadcast/multicast. */
428 if (!broadcast && !ip_addr_ismulticast(ip_current_dest_addr())) {
429 /* move payload pointer back to ip header */
430 pbuf_header_force(p, (s16_t)(ip_current_header_tot_len() + UDP_HLEN));
431 icmp_port_unreach(ip_current_is_v6(), p);
432 }
433 #endif /* LWIP_ICMP || LWIP_ICMP6 */
434 UDP_STATS_INC(udp.proterr);
435 UDP_STATS_INC(udp.drop);
436 MIB2_STATS_INC(mib2.udpnoports);
437 pbuf_free(p);
438 }
439 } else {
440 pbuf_free(p);
441 }
442 end:
443 PERF_STOP("udp_input");
444 return;
445 #if CHECKSUM_CHECK_UDP
446 chkerr:
447 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
448 ("udp_input: UDP (or UDP Lite) datagram discarded due to failing checksum\n"));
449 UDP_STATS_INC(udp.chkerr);
450 UDP_STATS_INC(udp.drop);
451 MIB2_STATS_INC(mib2.udpinerrors);
452 pbuf_free(p);
453 PERF_STOP("udp_input");
454 #endif /* CHECKSUM_CHECK_UDP */
455 }
456
457 /**
458 * @ingroup udp_raw
459 * Sends the pbuf p using UDP. The pbuf is not deallocated.
460 *
461 *
462 * @param pcb UDP PCB used to send the data.
463 * @param p chain of pbuf's to be sent.
464 *
465 * The datagram will be sent to the current remote_ip & remote_port
466 * stored in pcb. If the pcb is not bound to a port, it will
467 * automatically be bound to a random port.
468 *
469 * @return lwIP error code.
470 * - ERR_OK. Successful. No error occurred.
471 * - ERR_MEM. Out of memory.
472 * - ERR_RTE. Could not find route to destination address.
473 * - ERR_VAL. No PCB or PCB is dual-stack
474 * - More errors could be returned by lower protocol layers.
475 *
476 * @see udp_disconnect() udp_sendto()
477 */
478 err_t
udp_send(struct udp_pcb * pcb,struct pbuf * p)479 udp_send(struct udp_pcb *pcb, struct pbuf *p)
480 {
481 LWIP_ERROR("udp_send: invalid pcb", pcb != NULL, return ERR_ARG);
482 LWIP_ERROR("udp_send: invalid pbuf", p != NULL, return ERR_ARG);
483
484 if (IP_IS_ANY_TYPE_VAL(pcb->remote_ip)) {
485 return ERR_VAL;
486 }
487
488 /* send to the packet using remote ip and port stored in the pcb */
489 return udp_sendto(pcb, p, &pcb->remote_ip, pcb->remote_port);
490 }
491
492 #if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
493 /** @ingroup udp_raw
494 * Same as udp_send() but with checksum
495 */
496 err_t
udp_send_chksum(struct udp_pcb * pcb,struct pbuf * p,u8_t have_chksum,u16_t chksum)497 udp_send_chksum(struct udp_pcb *pcb, struct pbuf *p,
498 u8_t have_chksum, u16_t chksum)
499 {
500 LWIP_ERROR("udp_send_chksum: invalid pcb", pcb != NULL, return ERR_ARG);
501 LWIP_ERROR("udp_send_chksum: invalid pbuf", p != NULL, return ERR_ARG);
502
503 if (IP_IS_ANY_TYPE_VAL(pcb->remote_ip)) {
504 return ERR_VAL;
505 }
506
507 /* send to the packet using remote ip and port stored in the pcb */
508 return udp_sendto_chksum(pcb, p, &pcb->remote_ip, pcb->remote_port,
509 have_chksum, chksum);
510 }
511 #endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
512
513 /**
514 * @ingroup udp_raw
515 * Send data to a specified address using UDP.
516 *
517 * @param pcb UDP PCB used to send the data.
518 * @param p chain of pbuf's to be sent.
519 * @param dst_ip Destination IP address.
520 * @param dst_port Destination UDP port.
521 *
522 * dst_ip & dst_port are expected to be in the same byte order as in the pcb.
523 *
524 * If the PCB already has a remote address association, it will
525 * be restored after the data is sent.
526 *
527 * @return lwIP error code (@see udp_send for possible error codes)
528 *
529 * @see udp_disconnect() udp_send()
530 */
531 err_t
udp_sendto(struct udp_pcb * pcb,struct pbuf * p,const ip_addr_t * dst_ip,u16_t dst_port)532 udp_sendto(struct udp_pcb *pcb, struct pbuf *p,
533 const ip_addr_t *dst_ip, u16_t dst_port)
534 {
535 #if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
536 return udp_sendto_chksum(pcb, p, dst_ip, dst_port, 0, 0);
537 }
538
539 /** @ingroup udp_raw
540 * Same as udp_sendto(), but with checksum */
541 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)542 udp_sendto_chksum(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip,
543 u16_t dst_port, u8_t have_chksum, u16_t chksum)
544 {
545 #endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
546 struct netif *netif;
547
548 LWIP_ERROR("udp_sendto: invalid pcb", pcb != NULL, return ERR_ARG);
549 LWIP_ERROR("udp_sendto: invalid pbuf", p != NULL, return ERR_ARG);
550 LWIP_ERROR("udp_sendto: invalid dst_ip", dst_ip != NULL, return ERR_ARG);
551
552 if (!IP_ADDR_PCB_VERSION_MATCH(pcb, dst_ip)) {
553 return ERR_VAL;
554 }
555
556 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send\n"));
557
558 if (pcb->netif_idx != NETIF_NO_INDEX) {
559 netif = netif_get_by_index(pcb->netif_idx);
560 } else {
561 #if LWIP_MULTICAST_TX_OPTIONS
562 netif = NULL;
563 if (ip_addr_ismulticast(dst_ip)) {
564 /* For IPv6, the interface to use for packets with a multicast destination
565 * is specified using an interface index. The same approach may be used for
566 * IPv4 as well, in which case it overrides the IPv4 multicast override
567 * address below. Here we have to look up the netif by going through the
568 * list, but by doing so we skip a route lookup. If the interface index has
569 * gone stale, we fall through and do the regular route lookup after all. */
570 if (pcb->mcast_ifindex != NETIF_NO_INDEX) {
571 netif = netif_get_by_index(pcb->mcast_ifindex);
572 }
573 #if LWIP_IPV4
574 else
575 #if LWIP_IPV6
576 if (IP_IS_V4(dst_ip))
577 #endif /* LWIP_IPV6 */
578 {
579 /* IPv4 does not use source-based routing by default, so we use an
580 administratively selected interface for multicast by default.
581 However, this can be overridden by setting an interface address
582 in pcb->mcast_ip4 that is used for routing. If this routing lookup
583 fails, we try regular routing as though no override was set. */
584 if (!ip4_addr_isany_val(pcb->mcast_ip4) &&
585 !ip4_addr_cmp(&pcb->mcast_ip4, IP4_ADDR_BROADCAST)) {
586 netif = ip4_route_src(ip_2_ip4(&pcb->local_ip), &pcb->mcast_ip4);
587 }
588 }
589 #endif /* LWIP_IPV4 */
590 }
591
592 if (netif == NULL)
593 #endif /* LWIP_MULTICAST_TX_OPTIONS */
594 {
595 /* find the outgoing network interface for this packet */
596 netif = ip_route_pcb(dst_ip, (struct ip_pcb*)pcb);
597 }
598 }
599
600 /* no outgoing network interface could be found? */
601 if (netif == NULL) {
602 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: No route to "));
603 ip_addr_debug_print(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, dst_ip);
604 LWIP_DEBUGF(UDP_DEBUG, ("\n"));
605 UDP_STATS_INC(udp.rterr);
606 return ERR_NETUNREACH;
607 }
608 #if LWIP_MPL_IPV4
609 if ((IP_IS_V4_VAL(*dst_ip) || IP_IS_ANY_TYPE_VAL(*dst_ip)) &&
610 (ip4_addr_ismulticast(&(dst_ip->u_addr.ip4)) ||
611 (ip4_addr_netcmp(&(dst_ip->u_addr.ip4), netif_ip4_addr(netif), netif_ip4_netmask(netif)) &&
612 ((dst_ip->u_addr.ip4.addr & ~ip4_addr_get_u32(netif_ip4_netmask(netif))) ==
613 (IPADDR_BROADCAST & ~ip4_addr_get_u32(netif_ip4_netmask(netif))))))) {
614 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send: LWIP_MPL_IPV4_OUT"));
615 LWIP_MPL_IPV4_OUT(p, dst_ip, dst_port);
616 }
617 #endif /* LWIP_MPL_IPV4 */
618 #if (LWIP_IPV6 && LWIP_MPL)
619 if ((IP_IS_V6_VAL(*dst_ip) || IP_IS_ANY_TYPE_VAL(*dst_ip)) && ip6_addr_ismulticast(&(dst_ip->u_addr.ip6)) &&
620 (ip6_addr_multicast_scope(&(dst_ip->u_addr.ip6)) > IP6_MULTICAST_SCOPE_LINK_LOCAL)) {
621 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send: MCAST6_MPL_OUT"));
622 MCAST6_MPL_OUT(p, dst_ip, dst_port);
623 }
624 #endif /* LWIP_IPV6 && LWIP_MPL */
625 #if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
626 return udp_sendto_if_chksum(pcb, p, dst_ip, dst_port, netif, have_chksum, chksum);
627 #else /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
628 return udp_sendto_if(pcb, p, dst_ip, dst_port, netif);
629 #endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
630 }
631
632 /**
633 * @ingroup udp_raw
634 * Send data to a specified address using UDP.
635 * The netif used for sending can be specified.
636 *
637 * This function exists mainly for DHCP, to be able to send UDP packets
638 * on a netif that is still down.
639 *
640 * @param pcb UDP PCB used to send the data.
641 * @param p chain of pbuf's to be sent.
642 * @param dst_ip Destination IP address.
643 * @param dst_port Destination UDP port.
644 * @param netif the netif used for sending.
645 *
646 * dst_ip & dst_port are expected to be in the same byte order as in the pcb.
647 *
648 * @return lwIP error code (@see udp_send for possible error codes)
649 *
650 * @see udp_disconnect() udp_send()
651 */
652 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)653 udp_sendto_if(struct udp_pcb *pcb, struct pbuf *p,
654 const ip_addr_t *dst_ip, u16_t dst_port, struct netif *netif)
655 {
656 #if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
657 return udp_sendto_if_chksum(pcb, p, dst_ip, dst_port, netif, 0, 0);
658 }
659
660 /** Same as udp_sendto_if(), but with checksum */
661 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)662 udp_sendto_if_chksum(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip,
663 u16_t dst_port, struct netif *netif, u8_t have_chksum,
664 u16_t chksum)
665 {
666 #endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
667 const ip_addr_t *src_ip;
668
669 LWIP_ERROR("udp_sendto_if: invalid pcb", pcb != NULL, return ERR_ARG);
670 LWIP_ERROR("udp_sendto_if: invalid pbuf", p != NULL, return ERR_ARG);
671 LWIP_ERROR("udp_sendto_if: invalid dst_ip", dst_ip != NULL, return ERR_ARG);
672 LWIP_ERROR("udp_sendto_if: invalid netif", netif != NULL, return ERR_ARG);
673
674 if (!IP_ADDR_PCB_VERSION_MATCH(pcb, dst_ip)) {
675 return ERR_VAL;
676 }
677
678 /* PCB local address is IP_ANY_ADDR or multicast? */
679 #if LWIP_IPV6
680 if (IP_IS_V6(dst_ip)) {
681 if (ip6_addr_isany(ip_2_ip6(&pcb->local_ip)) ||
682 ip6_addr_ismulticast(ip_2_ip6(&pcb->local_ip)) ||
683 ip_get_option(pcb, SOF_BINDNONUNICAST)) {
684 src_ip = ip6_select_source_address(netif, ip_2_ip6(dst_ip));
685 if (src_ip == NULL) {
686 /* No suitable source address was found. */
687 return ERR_RTE;
688 }
689 } else {
690 /* use UDP PCB local IPv6 address as source address, if still valid. */
691 if (netif_get_ip6_addr_match(netif, ip_2_ip6(&pcb->local_ip)) < 0) {
692 /* Address isn't valid anymore. */
693 return ERR_RTE;
694 }
695 src_ip = &pcb->local_ip;
696 }
697 }
698 #endif /* LWIP_IPV6 */
699 #if LWIP_IPV4 && LWIP_IPV6
700 else
701 #endif /* LWIP_IPV4 && LWIP_IPV6 */
702 #if LWIP_IPV4
703 if (ip4_addr_isany(ip_2_ip4(&pcb->local_ip)) ||
704 ip4_addr_ismulticast(ip_2_ip4(&pcb->local_ip)) ||
705 ip_get_option(pcb, SOF_BINDNONUNICAST)) {
706 /* if the local_ip is any or multicast
707 * use the outgoing network interface IP address as source address */
708 src_ip = netif_ip_addr4(netif);
709 } else {
710 /* check if UDP PCB local IP address is correct
711 * this could be an old address if netif->ip_addr has changed */
712 if (!ip4_addr_cmp(ip_2_ip4(&(pcb->local_ip)), netif_ip4_addr(netif))) {
713 /* local_ip doesn't match, drop the packet */
714 return ERR_RTE;
715 }
716 /* use UDP PCB local IP address as source address */
717 src_ip = &pcb->local_ip;
718 }
719 #endif /* LWIP_IPV4 */
720 #if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
721 return udp_sendto_if_src_chksum(pcb, p, dst_ip, dst_port, netif, have_chksum, chksum, src_ip);
722 #else /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
723 return udp_sendto_if_src(pcb, p, dst_ip, dst_port, netif, src_ip);
724 #endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
725 }
726
727 /** @ingroup udp_raw
728 * Same as @ref udp_sendto_if, but with source address */
729 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)730 udp_sendto_if_src(struct udp_pcb *pcb, struct pbuf *p,
731 const ip_addr_t *dst_ip, u16_t dst_port, struct netif *netif, const ip_addr_t *src_ip)
732 {
733 #if LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP
734 return udp_sendto_if_src_chksum(pcb, p, dst_ip, dst_port, netif, 0, 0, src_ip);
735 }
736
737 /** Same as udp_sendto_if_src(), but with checksum */
738 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)739 udp_sendto_if_src_chksum(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip,
740 u16_t dst_port, struct netif *netif, u8_t have_chksum,
741 u16_t chksum, const ip_addr_t *src_ip)
742 {
743 #endif /* LWIP_CHECKSUM_ON_COPY && CHECKSUM_GEN_UDP */
744 struct udp_hdr *udphdr;
745 err_t err;
746 struct pbuf *q; /* q will be sent down the stack */
747 u8_t ip_proto;
748 u8_t ttl;
749
750 LWIP_ASSERT_CORE_LOCKED();
751 if ((pcb == NULL) || (dst_ip == NULL) || !IP_ADDR_PCB_VERSION_MATCH(pcb, src_ip) ||
752 !IP_ADDR_PCB_VERSION_MATCH(pcb, dst_ip)) {
753 return ERR_VAL;
754 }
755
756 #if LWIP_IPV4 && IP_SOF_BROADCAST
757 /* broadcast filter? */
758 if (!ip_get_option(pcb, SOF_BROADCAST) &&
759 #if LWIP_IPV6
760 IP_IS_V4(dst_ip) &&
761 #endif /* LWIP_IPV6 */
762 ip_addr_isbroadcast(dst_ip, netif)) {
763 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
764 ("udp_sendto_if: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
765 return ERR_ACCESS;
766 }
767 #endif /* LWIP_IPV4 && IP_SOF_BROADCAST */
768
769 /* if the PCB is not yet bound to a port, bind it here */
770 if (pcb->local_port == 0) {
771 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send: not yet bound to a port, binding now\n"));
772 err = udp_bind(pcb, &pcb->local_ip, pcb->local_port);
773 if (err != ERR_OK) {
774 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: forced port bind failed\n"));
775 return ((pcb->local_port == 0 && err == ERR_USE) ? ERR_TIMEOUT : err);
776 }
777 }
778
779 /* packet too large to add a UDP header without causing an overflow? */
780 if ((u16_t)(p->tot_len + UDP_HLEN) < p->tot_len) {
781 return ERR_MEM;
782 }
783 /* not enough space to add an UDP header to first pbuf in given p chain? */
784 if (pbuf_add_header(p, UDP_HLEN)) {
785 /* allocate header in a separate new pbuf */
786 q = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM);
787 /* new header pbuf could not be allocated? */
788 if (q == NULL) {
789 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: could not allocate header\n"));
790 return ERR_MEM;
791 }
792 if (p->tot_len != 0) {
793 /* chain header q in front of given pbuf p (only if p contains data) */
794 pbuf_chain(q, p);
795 }
796 /* first pbuf q points to header pbuf */
797 LWIP_DEBUGF(UDP_DEBUG,
798 ("udp_send: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
799 } else {
800 /* adding space for header within p succeeded */
801 /* first pbuf q equals given pbuf */
802 q = p;
803 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: added header in given pbuf %p\n", (void *)p));
804 }
805 LWIP_ASSERT("check that first pbuf can hold struct udp_hdr",
806 (q->len >= sizeof(struct udp_hdr)));
807 /* q now represents the packet to be sent */
808 udphdr = (struct udp_hdr *)q->payload;
809 udphdr->src = lwip_htons(pcb->local_port);
810 udphdr->dest = lwip_htons(dst_port);
811 /* in UDP, 0 checksum means 'no checksum' */
812 udphdr->chksum = 0x0000;
813
814 /* Multicast Loop? */
815 #if LWIP_MULTICAST_TX_OPTIONS
816 if (((pcb->flags & UDP_FLAGS_MULTICAST_LOOP) != 0) && ip_addr_ismulticast(dst_ip)) {
817 q->flags |= PBUF_FLAG_MCASTLOOP;
818 }
819 #endif /* LWIP_MULTICAST_TX_OPTIONS */
820
821 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %"U16_F"\n", q->tot_len));
822
823 #if LWIP_UDPLITE
824 /* UDP Lite protocol? */
825 if (pcb->flags & UDP_FLAGS_UDPLITE) {
826 u16_t chklen, chklen_hdr;
827 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE packet length %"U16_F"\n", q->tot_len));
828 /* set UDP message length in UDP header */
829 chklen_hdr = chklen = pcb->chksum_len_tx;
830 if ((chklen < sizeof(struct udp_hdr)) || (chklen > q->tot_len)) {
831 if (chklen != 0) {
832 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE pcb->chksum_len is illegal: %"U16_F"\n", chklen));
833 }
834 /* For UDP-Lite, checksum length of 0 means checksum
835 over the complete packet. (See RFC 3828 chap. 3.1)
836 At least the UDP-Lite header must be covered by the
837 checksum, therefore, if chksum_len has an illegal
838 value, we generate the checksum over the complete
839 packet to be safe. */
840 chklen_hdr = 0;
841 chklen = q->tot_len;
842 }
843 udphdr->len = lwip_htons(chklen_hdr);
844 pcb->last_payload_len = (u32_t)(chklen_hdr - UDP_HLEN);
845 /* calculate checksum */
846 #if CHECKSUM_GEN_UDP
847 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_UDP) {
848 #if LWIP_CHECKSUM_ON_COPY
849 if (have_chksum) {
850 chklen = UDP_HLEN;
851 }
852 #endif /* LWIP_CHECKSUM_ON_COPY */
853 udphdr->chksum = ip_chksum_pseudo_partial(q, IP_PROTO_UDPLITE,
854 q->tot_len, chklen, src_ip, dst_ip);
855 #if LWIP_CHECKSUM_ON_COPY
856 if (have_chksum) {
857 u32_t acc;
858 acc = udphdr->chksum + (u16_t)~(chksum);
859 udphdr->chksum = FOLD_U32T(acc);
860 }
861 #endif /* LWIP_CHECKSUM_ON_COPY */
862
863 /* chksum zero must become 0xffff, as zero means 'no checksum' */
864 if (udphdr->chksum == 0x0000) {
865 udphdr->chksum = 0xffff;
866 }
867 }
868 #endif /* CHECKSUM_GEN_UDP */
869
870 ip_proto = IP_PROTO_UDPLITE;
871 } else
872 #endif /* LWIP_UDPLITE */
873 { /* UDP */
874 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP packet length %"U16_F"\n", q->tot_len));
875 udphdr->len = lwip_htons(q->tot_len);
876 pcb->last_payload_len = (u32_t)(q->tot_len - UDP_HLEN);
877 /* calculate checksum */
878 #if CHECKSUM_GEN_UDP
879 IF__NETIF_CHECKSUM_ENABLED(netif, NETIF_CHECKSUM_GEN_UDP) {
880 /* Checksum is mandatory over IPv6. */
881 if (IP_IS_V6(dst_ip) || (pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) {
882 u16_t udpchksum;
883 #if LWIP_CHECKSUM_ON_COPY
884 if (have_chksum) {
885 u32_t acc;
886 udpchksum = ip_chksum_pseudo_partial(q, IP_PROTO_UDP,
887 q->tot_len, UDP_HLEN, src_ip, dst_ip);
888 acc = udpchksum + (u16_t)~(chksum);
889 udpchksum = FOLD_U32T(acc);
890 } else
891 #endif /* LWIP_CHECKSUM_ON_COPY */
892 {
893 udpchksum = ip_chksum_pseudo(q, IP_PROTO_UDP, q->tot_len,
894 src_ip, dst_ip);
895 }
896
897 /* chksum zero must become 0xffff, as zero means 'no checksum' */
898 if (udpchksum == 0x0000) {
899 udpchksum = 0xffff;
900 }
901 udphdr->chksum = udpchksum;
902 }
903 }
904 #endif /* CHECKSUM_GEN_UDP */
905 ip_proto = IP_PROTO_UDP;
906 }
907
908 /* Determine TTL to use */
909 #if LWIP_MULTICAST_TX_OPTIONS
910 ttl = (ip_addr_ismulticast(dst_ip) ? udp_get_multicast_ttl(pcb) : pcb->ttl);
911 #else /* LWIP_MULTICAST_TX_OPTIONS */
912 ttl = pcb->ttl;
913 #endif /* LWIP_MULTICAST_TX_OPTIONS */
914 #if LWIP_SO_DONTROUTE
915 if (ip_get_option((struct ip_pcb *)pcb, SOF_DONTROUTE)) {
916 q->flags |= PBUF_FLAG_IS_LINK_ONLY;
917 }
918 #endif /* LWIP_SO_DONTROUTE */
919
920 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum 0x%04"X16_F"\n", udphdr->chksum));
921 LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,0x%02"X16_F",)\n", (u16_t)ip_proto));
922
923 #if LWIP_SO_PRIORITY
924 q->priority = pcb->priority;
925 #endif /* LWIP_SO_PRIORITY */
926
927 /* output to IP */
928 NETIF_SET_HINTS(netif, &(pcb->netif_hints));
929 err = ip_output_if_src(q, src_ip, dst_ip, ttl, pcb->tos, ip_proto, netif);
930 NETIF_RESET_HINTS(netif);
931
932 /* @todo: must this be increased even if error occurred? */
933 MIB2_STATS_INC(mib2.udpoutdatagrams);
934
935 /* did we chain a separate header pbuf earlier? */
936 if (q != p) {
937 /* free the header pbuf */
938 pbuf_free(q);
939 q = NULL;
940 /* p is still referenced by the caller, and will live on */
941 }
942
943 UDP_STATS_INC(udp.xmit);
944 return err;
945 }
946
947 /**
948 * @ingroup udp_raw
949 * Bind an UDP PCB.
950 *
951 * @param pcb UDP PCB to be bound with a local address ipaddr and port.
952 * @param ipaddr local IP address to bind with. Use IP_ANY_TYPE to
953 * bind to all local interfaces.
954 * @param port local UDP port to bind with. Use 0 to automatically bind
955 * to a random port between UDP_LOCAL_PORT_RANGE_START and
956 * UDP_LOCAL_PORT_RANGE_END.
957 *
958 * ipaddr & port are expected to be in the same byte order as in the pcb.
959 *
960 * @return lwIP error code.
961 * - ERR_OK. Successful. No error occurred.
962 * - ERR_USE. The specified ipaddr and port are already bound to by
963 * another UDP PCB.
964 *
965 * @see udp_disconnect()
966 */
967 err_t
udp_bind(struct udp_pcb * pcb,const ip_addr_t * ipaddr,u16_t port)968 udp_bind(struct udp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port)
969 {
970 struct udp_pcb *ipcb;
971 u8_t rebind;
972 #if LWIP_IPV6 && LWIP_IPV6_SCOPES
973 ip_addr_t zoned_ipaddr;
974 #endif /* LWIP_IPV6 && LWIP_IPV6_SCOPES */
975
976 LWIP_ASSERT_CORE_LOCKED();
977
978 #if LWIP_IPV4
979 /* Don't propagate NULL pointer (IPv4 ANY) to subsequent functions */
980 if (ipaddr == NULL) {
981 ipaddr = IP4_ADDR_ANY;
982 }
983 #else /* LWIP_IPV4 */
984 LWIP_ERROR("udp_bind: invalid ipaddr", ipaddr != NULL, return ERR_ARG);
985 #endif /* LWIP_IPV4 */
986
987 LWIP_ERROR("udp_bind: invalid pcb", pcb != NULL, return ERR_ARG);
988
989 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_bind(ipaddr = "));
990 ip_addr_debug_print(UDP_DEBUG | LWIP_DBG_TRACE, ipaddr);
991 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, (", port = %"U16_F")\n", port));
992
993 rebind = 0;
994 /* Check for double bind and rebind of the same pcb */
995 for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
996 /* is this UDP PCB already on active list? */
997 if (pcb == ipcb) {
998 rebind = 1;
999 break;
1000 }
1001 /* omit the confilcting check if the pcbs bind to diff netif */
1002 if (ipcb->netif_idx && pcb->netif_idx && (pcb->netif_idx != ipcb->netif_idx)) {
1003 continue;
1004 }
1005 }
1006
1007 #if LWIP_IPV6 && LWIP_IPV6_SCOPES
1008 /* If the given IP address should have a zone but doesn't, assign one now.
1009 * This is legacy support: scope-aware callers should always provide properly
1010 * zoned source addresses. Do the zone selection before the address-in-use
1011 * check below; as such we have to make a temporary copy of the address. */
1012 if (IP_IS_V6(ipaddr) && ip6_addr_lacks_zone(ip_2_ip6(ipaddr), IP6_UNKNOWN)) {
1013 ip_addr_copy(zoned_ipaddr, *ipaddr);
1014 ip6_addr_select_zone(ip_2_ip6(&zoned_ipaddr), ip_2_ip6(&zoned_ipaddr));
1015 ipaddr = &zoned_ipaddr;
1016 }
1017 #endif /* LWIP_IPV6 && LWIP_IPV6_SCOPES */
1018
1019 /* no port specified? */
1020 if (port == 0) {
1021 port = udp_new_port();
1022 if (port == 0) {
1023 /* no more ports available in local range */
1024 LWIP_DEBUGF(UDP_DEBUG, ("udp_bind: out of free UDP ports\n"));
1025 return ERR_USE;
1026 }
1027 } else {
1028 for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
1029 if (pcb != ipcb) {
1030 /* By default, we don't allow to bind to a port that any other udp
1031 PCB is already bound to, unless *all* PCBs with that port have tha
1032 REUSEADDR flag set. */
1033 #if SO_REUSE
1034 if (!ip_get_option(pcb, SOF_REUSEADDR) ||
1035 !ip_get_option(ipcb, SOF_REUSEADDR))
1036 #endif /* SO_REUSE */
1037 {
1038 /* port matches that of PCB in list and REUSEADDR not set -> reject */
1039 if ((ipcb->local_port == port) &&
1040 (((IP_GET_TYPE(&ipcb->local_ip) == IP_GET_TYPE(ipaddr)) &&
1041 /* IP address matches or any IP used? */
1042 (ip_addr_cmp(&ipcb->local_ip, ipaddr) ||
1043 ip_addr_isany(ipaddr) ||
1044 ip_addr_isany(&ipcb->local_ip))) ||
1045 (IP_GET_TYPE(&ipcb->local_ip) == IPADDR_TYPE_ANY) ||
1046 (IP_GET_TYPE(ipaddr) == IPADDR_TYPE_ANY))) {
1047 /* other PCB already binds to this local IP and port */
1048 LWIP_DEBUGF(UDP_DEBUG,
1049 ("udp_bind: local port %"U16_F" already bound by another pcb\n", port));
1050 return ERR_USE;
1051 }
1052 }
1053 }
1054 }
1055 }
1056
1057 ip_addr_set_ipaddr(&pcb->local_ip, ipaddr);
1058 if (netif_ipaddr_isbrdcast(ipaddr) || ip_addr_ismulticast(ipaddr)) {
1059 ip_set_option(pcb, SOF_BINDNONUNICAST);
1060 } else {
1061 ip_reset_option(pcb, SOF_BINDNONUNICAST);
1062 }
1063
1064 pcb->local_port = port;
1065 mib2_udp_bind(pcb);
1066 /* pcb not active yet? */
1067 if (rebind == 0) {
1068 /* place the PCB on the active list if not already there */
1069 pcb->next = udp_pcbs;
1070 udp_pcbs = pcb;
1071 }
1072 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("udp_bind: bound to "));
1073 ip_addr_debug_print_val(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, pcb->local_ip);
1074 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, (", port %"U16_F")\n", pcb->local_port));
1075 return ERR_OK;
1076 }
1077
1078 /**
1079 * @ingroup udp_raw
1080 * Bind an UDP PCB to a specific netif.
1081 * After calling this function, all packets received via this PCB
1082 * are guaranteed to have come in via the specified netif, and all
1083 * outgoing packets will go out via the specified netif.
1084 *
1085 * @param pcb UDP PCB to be bound.
1086 * @param netif netif to bind udp pcb to. Can be NULL.
1087 *
1088 * @see udp_disconnect()
1089 */
1090 void
udp_bind_netif(struct udp_pcb * pcb,const struct netif * netif)1091 udp_bind_netif(struct udp_pcb *pcb, const struct netif *netif)
1092 {
1093 LWIP_ASSERT_CORE_LOCKED();
1094
1095 if (netif != NULL) {
1096 pcb->netif_idx = netif_get_index(netif);
1097 } else {
1098 pcb->netif_idx = NETIF_NO_INDEX;
1099 }
1100 }
1101
1102 /**
1103 * @ingroup udp_raw
1104 * Sets the remote end of the pcb. This function does not generate any
1105 * network traffic, but only sets the remote address of the pcb.
1106 *
1107 * @param pcb UDP PCB to be connected with remote address ipaddr and port.
1108 * @param ipaddr remote IP address to connect with.
1109 * @param port remote UDP port to connect with.
1110 *
1111 * @return lwIP error code
1112 *
1113 * ipaddr & port are expected to be in the same byte order as in the pcb.
1114 *
1115 * The udp pcb is bound to a random local port if not already bound.
1116 *
1117 * @see udp_disconnect()
1118 */
1119 err_t
udp_connect(struct udp_pcb * pcb,const ip_addr_t * ipaddr,u16_t port)1120 udp_connect(struct udp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port)
1121 {
1122 struct udp_pcb *ipcb = NULL;
1123 struct netif *netif = NULL;
1124
1125 SYS_ARCH_DECL_PROTECT(lev);
1126
1127 if ((pcb == NULL) || (ipaddr == NULL)) {
1128 return ERR_VAL;
1129 }
1130
1131 if (!ip_addr_isany(ipaddr)) {
1132 netif = ip_route_pcb(ipaddr, (struct ip_pcb*)pcb);
1133 if (netif == NULL) {
1134 return ERR_NETUNREACH;
1135 }
1136
1137 if (!ip_get_option(pcb, SOF_BROADCAST) && ip_addr_isbroadcast(ipaddr, netif)) {
1138 return ERR_ACCESS;
1139 }
1140 }
1141
1142 if (pcb->local_port == 0) {
1143 err_t err = udp_bind(pcb, &pcb->local_ip, pcb->local_port);
1144 if (err != ERR_OK) {
1145 return err;
1146 }
1147 }
1148
1149 /* Nail down local IP for netconn_addr()/getsockname() */
1150 if (ip_addr_isany(&pcb->local_ip) && !ip_addr_isany(ipaddr)) {
1151 /* no local IP address set, yet. */
1152 const ip_addr_t *local_ip = ip_netif_get_local_ip(netif, ipaddr);
1153 if ((local_ip == NULL)) {
1154 return ERR_NETUNREACH;
1155 }
1156 /* Use the address as local address of the pcb. */
1157 ip_addr_copy(pcb->local_ip, *local_ip);
1158 }
1159
1160 ip_addr_set_ipaddr(&pcb->remote_ip, ipaddr);
1161 #if LWIP_IPV6 && LWIP_IPV6_SCOPES
1162 /* If the given IP address should have a zone but doesn't, assign one now,
1163 * using the bound address to make a more informed decision when possible. */
1164 if (IP_IS_V6(&pcb->remote_ip) &&
1165 ip6_addr_lacks_zone(ip_2_ip6(&pcb->remote_ip), IP6_UNKNOWN)) {
1166 ip6_addr_select_zone(ip_2_ip6(&pcb->remote_ip), ip_2_ip6(&pcb->local_ip));
1167 }
1168 #endif /* LWIP_IPV6 && LWIP_IPV6_SCOPES */
1169
1170 pcb->remote_port = port;
1171
1172 SYS_ARCH_PROTECT(lev);
1173 pcb->flags |= UDP_FLAGS_CONNECTED;
1174
1175 SYS_ARCH_UNPROTECT(lev);
1176 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, ("udp_connect: connected to "));
1177 ip_addr_debug_print_val(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
1178 pcb->remote_ip);
1179 LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, (", port %"U16_F")\n", pcb->remote_port));
1180
1181 /* Insert UDP PCB into the list of active UDP PCBs. */
1182 for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
1183 if (pcb == ipcb) {
1184 /* already on the list, just return */
1185 return ERR_OK;
1186 }
1187 }
1188 /* PCB not yet on the list, add PCB now */
1189 pcb->next = udp_pcbs;
1190 udp_pcbs = pcb;
1191 return ERR_OK;
1192 }
1193
1194 /**
1195 * @ingroup udp_raw
1196 * Remove the remote end of the pcb. This function does not generate
1197 * any network traffic, but only removes the remote address of the pcb.
1198 *
1199 * @param pcb the udp pcb to disconnect.
1200 */
1201 void
udp_disconnect(struct udp_pcb * pcb)1202 udp_disconnect(struct udp_pcb *pcb)
1203 {
1204 SYS_ARCH_DECL_PROTECT(lev);
1205 LWIP_ASSERT_CORE_LOCKED();
1206
1207 LWIP_ERROR("udp_disconnect: invalid pcb", pcb != NULL, return);
1208
1209 /* reset remote address association */
1210 #if LWIP_IPV4 && LWIP_IPV6
1211 if (IP_IS_ANY_TYPE_VAL(pcb->local_ip)) {
1212 ip_addr_copy(pcb->remote_ip, *IP_ANY_TYPE);
1213 } else {
1214 #endif
1215 ip_addr_set_any(IP_IS_V6_VAL(pcb->remote_ip), &pcb->remote_ip);
1216 #if LWIP_IPV4 && LWIP_IPV6
1217 }
1218 #endif
1219 pcb->remote_port = 0;
1220
1221 SYS_ARCH_PROTECT(lev);
1222 /* mark PCB as unconnected */
1223 udp_clear_flags(pcb, UDP_FLAGS_CONNECTED);
1224 SYS_ARCH_UNPROTECT(lev);
1225 }
1226
1227 /**
1228 * @ingroup udp_raw
1229 * Set a receive callback for a UDP PCB.
1230 * This callback will be called when receiving a datagram for the pcb.
1231 *
1232 * @param pcb the pcb for which to set the recv callback
1233 * @param recv function pointer of the callback function
1234 * @param recv_arg additional argument to pass to the callback function
1235 */
1236 void
udp_recv(struct udp_pcb * pcb,udp_recv_fn recv,void * recv_arg)1237 udp_recv(struct udp_pcb *pcb, udp_recv_fn recv, void *recv_arg)
1238 {
1239 LWIP_ASSERT_CORE_LOCKED();
1240
1241 LWIP_ERROR("udp_recv: invalid pcb", pcb != NULL, return);
1242
1243 /* remember recv() callback and user data */
1244 pcb->recv = recv;
1245 pcb->recv_arg = recv_arg;
1246 }
1247
1248 /**
1249 * @ingroup udp_raw
1250 * Removes and deallocates the pcb.
1251 *
1252 * @param pcb UDP PCB to be removed. The PCB is removed from the list of
1253 * UDP PCB's and the data structure is freed from memory.
1254 *
1255 * @see udp_new()
1256 */
1257 void
udp_remove(struct udp_pcb * pcb)1258 udp_remove(struct udp_pcb *pcb)
1259 {
1260 struct udp_pcb *pcb2;
1261
1262 LWIP_ASSERT_CORE_LOCKED();
1263
1264 LWIP_ERROR("udp_remove: invalid pcb", pcb != NULL, return);
1265
1266 mib2_udp_unbind(pcb);
1267 /* pcb to be removed is first in list? */
1268 if (udp_pcbs == pcb) {
1269 /* make list start at 2nd pcb */
1270 udp_pcbs = udp_pcbs->next;
1271 /* pcb not 1st in list */
1272 } else {
1273 for (pcb2 = udp_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
1274 /* find pcb in udp_pcbs list */
1275 if (pcb2->next != NULL && pcb2->next == pcb) {
1276 /* remove pcb from list */
1277 pcb2->next = pcb->next;
1278 break;
1279 }
1280 }
1281 }
1282 memp_free(MEMP_UDP_PCB, pcb);
1283 }
1284
1285 /**
1286 * @ingroup udp_raw
1287 * Creates a new UDP pcb which can be used for UDP communication. The
1288 * pcb is not active until it has either been bound to a local address
1289 * or connected to a remote address.
1290 * @see MEMP_NUM_UDP_PCB
1291 *
1292 * @return The UDP PCB which was created. NULL if the PCB data structure
1293 * could not be allocated.
1294 *
1295 * @see udp_remove()
1296 */
1297 struct udp_pcb *
udp_new(void)1298 udp_new(void)
1299 {
1300 struct udp_pcb *pcb;
1301
1302 LWIP_ASSERT_CORE_LOCKED();
1303
1304 pcb = (struct udp_pcb *)memp_malloc(MEMP_UDP_PCB);
1305 /* could allocate UDP PCB? */
1306 if (pcb != NULL) {
1307 /* UDP Lite: by initializing to all zeroes, chksum_len is set to 0
1308 * which means checksum is generated over the whole datagram per default
1309 * (recommended as default by RFC 3828). */
1310 /* initialize PCB to all zeroes */
1311 memset(pcb, 0, sizeof(struct udp_pcb));
1312 pcb->ttl = UDP_TTL;
1313 #if LWIP_MULTICAST_TX_OPTIONS
1314 udp_setflags(pcb, UDP_FLAGS_MULTICAST_LOOP);
1315 udp_set_multicast_ttl(pcb, MC_TTL);
1316 #endif /* LWIP_MULTICAST_TX_OPTIONS */
1317 }
1318 return pcb;
1319 }
1320
1321 /**
1322 * @ingroup udp_raw
1323 * Create a UDP PCB for specific IP type.
1324 * The pcb is not active until it has either been bound to a local address
1325 * or connected to a remote address.
1326 * @see MEMP_NUM_UDP_PCB
1327 *
1328 * @param type IP address type, see @ref lwip_ip_addr_type definitions.
1329 * If you want to listen to IPv4 and IPv6 (dual-stack) packets,
1330 * supply @ref IPADDR_TYPE_ANY as argument and bind to @ref IP_ANY_TYPE.
1331 * @return The UDP PCB which was created. NULL if the PCB data structure
1332 * could not be allocated.
1333 *
1334 * @see udp_remove()
1335 */
1336 struct udp_pcb *
udp_new_ip_type(u8_t type)1337 udp_new_ip_type(u8_t type)
1338 {
1339 struct udp_pcb *pcb;
1340
1341 LWIP_ASSERT_CORE_LOCKED();
1342
1343 pcb = udp_new();
1344 #if LWIP_IPV4 && LWIP_IPV6
1345 if (pcb != NULL) {
1346 IP_SET_TYPE_VAL(pcb->local_ip, type);
1347 IP_SET_TYPE_VAL(pcb->remote_ip, type);
1348 }
1349 #else
1350 LWIP_UNUSED_ARG(type);
1351 #endif /* LWIP_IPV4 && LWIP_IPV6 */
1352 return pcb;
1353 }
1354
1355 /** This function is called from netif.c when address is changed
1356 *
1357 * @param old_addr IP address of the netif before change
1358 * @param new_addr IP address of the netif after change
1359 */
udp_netif_ip_addr_changed(const ip_addr_t * old_addr,const ip_addr_t * new_addr)1360 void udp_netif_ip_addr_changed(const ip_addr_t *old_addr, const ip_addr_t *new_addr)
1361 {
1362 struct udp_pcb *upcb;
1363
1364 if (!ip_addr_isany(old_addr) && !ip_addr_isany(new_addr)) {
1365 for (upcb = udp_pcbs; upcb != NULL; upcb = upcb->next) {
1366 /* PCB bound to current local interface address? */
1367 if (ip_addr_cmp(&upcb->local_ip, old_addr)) {
1368 /* The PCB is bound to the old ipaddr and
1369 * is set to bound to the new one instead */
1370 ip_addr_copy(upcb->local_ip, *new_addr);
1371 }
1372 }
1373 }
1374 }
1375
1376 #if UDP_DEBUG
1377 /**
1378 * Print UDP header information for debug purposes.
1379 *
1380 * @param udphdr pointer to the udp header in memory.
1381 */
1382 void
udp_debug_print(struct udp_hdr * udphdr)1383 udp_debug_print(struct udp_hdr *udphdr)
1384 {
1385 LWIP_DEBUGF(UDP_DEBUG, ("UDP header:\n"));
1386 LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
1387 LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | %5"U16_F" | (src port, dest port)\n",
1388 lwip_ntohs(udphdr->src), lwip_ntohs(udphdr->dest)));
1389 LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
1390 LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | 0x%04"X16_F" | (len, chksum)\n",
1391 lwip_ntohs(udphdr->len), lwip_ntohs(udphdr->chksum)));
1392 LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
1393 }
1394 #endif /* UDP_DEBUG */
1395
1396 #endif /* LWIP_UDP */
1397