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