1 /*
2 * RTP network protocol
3 * Copyright (c) 2002 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 /**
23 * @file
24 * RTP protocol
25 */
26
27 #include "libavutil/parseutils.h"
28 #include "libavutil/avstring.h"
29 #include "libavutil/opt.h"
30 #include "avformat.h"
31 #include "avio_internal.h"
32 #include "rtp.h"
33 #include "rtpproto.h"
34 #include "url.h"
35 #include "ip.h"
36
37 #include <stdarg.h>
38 #include "internal.h"
39 #include "network.h"
40 #include "os_support.h"
41 #include <fcntl.h>
42 #if HAVE_POLL_H
43 #include <poll.h>
44 #endif
45
46 typedef struct RTPContext {
47 const AVClass *class;
48 URLContext *rtp_hd, *rtcp_hd, *fec_hd;
49 int rtp_fd, rtcp_fd;
50 IPSourceFilters filters;
51 int write_to_source;
52 struct sockaddr_storage last_rtp_source, last_rtcp_source;
53 socklen_t last_rtp_source_len, last_rtcp_source_len;
54 int ttl;
55 int buffer_size;
56 int rtcp_port, local_rtpport, local_rtcpport;
57 int connect;
58 int pkt_size;
59 int dscp;
60 char *sources;
61 char *block;
62 char *fec_options_str;
63 } RTPContext;
64
65 #define OFFSET(x) offsetof(RTPContext, x)
66 #define D AV_OPT_FLAG_DECODING_PARAM
67 #define E AV_OPT_FLAG_ENCODING_PARAM
68 static const AVOption options[] = {
69 { "ttl", "Time to live (in milliseconds, multicast only)", OFFSET(ttl), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
70 { "buffer_size", "Send/Receive buffer size (in bytes)", OFFSET(buffer_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
71 { "rtcp_port", "Custom rtcp port", OFFSET(rtcp_port), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
72 { "local_rtpport", "Local rtp port", OFFSET(local_rtpport), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
73 { "local_rtcpport", "Local rtcp port", OFFSET(local_rtcpport), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
74 { "connect", "Connect socket", OFFSET(connect), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, .flags = D|E },
75 { "write_to_source", "Send packets to the source address of the latest received packet", OFFSET(write_to_source), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, .flags = D|E },
76 { "pkt_size", "Maximum packet size", OFFSET(pkt_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
77 { "dscp", "DSCP class", OFFSET(dscp), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
78 { "sources", "Source list", OFFSET(sources), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = D|E },
79 { "block", "Block list", OFFSET(block), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = D|E },
80 { "fec", "FEC", OFFSET(fec_options_str), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = E },
81 { NULL }
82 };
83
84 static const AVClass rtp_class = {
85 .class_name = "rtp",
86 .item_name = av_default_item_name,
87 .option = options,
88 .version = LIBAVUTIL_VERSION_INT,
89 };
90
91 /**
92 * If no filename is given to av_open_input_file because you want to
93 * get the local port first, then you must call this function to set
94 * the remote server address.
95 *
96 * @param h media file context
97 * @param uri of the remote server
98 * @return zero if no error.
99 */
100
ff_rtp_set_remote_url(URLContext * h,const char * uri)101 int ff_rtp_set_remote_url(URLContext *h, const char *uri)
102 {
103 RTPContext *s = h->priv_data;
104 char hostname[256];
105 int port, rtcp_port;
106 const char *p;
107
108 char buf[1024];
109 char path[1024];
110
111 av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
112 path, sizeof(path), uri);
113 rtcp_port = port + 1;
114
115 p = strchr(uri, '?');
116 if (p) {
117 if (av_find_info_tag(buf, sizeof(buf), "rtcpport", p)) {
118 rtcp_port = strtol(buf, NULL, 10);
119 }
120 }
121
122 ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port, "%s", path);
123 ff_udp_set_remote_url(s->rtp_hd, buf);
124
125 ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, rtcp_port, "%s", path);
126 ff_udp_set_remote_url(s->rtcp_hd, buf);
127 return 0;
128 }
129
get_port(const struct sockaddr_storage * ss)130 static int get_port(const struct sockaddr_storage *ss)
131 {
132 if (ss->ss_family == AF_INET)
133 return ntohs(((const struct sockaddr_in *)ss)->sin_port);
134 #if HAVE_STRUCT_SOCKADDR_IN6
135 if (ss->ss_family == AF_INET6)
136 return ntohs(((const struct sockaddr_in6 *)ss)->sin6_port);
137 #endif
138 return 0;
139 }
140
set_port(struct sockaddr_storage * ss,int port)141 static void set_port(struct sockaddr_storage *ss, int port)
142 {
143 if (ss->ss_family == AF_INET)
144 ((struct sockaddr_in *)ss)->sin_port = htons(port);
145 #if HAVE_STRUCT_SOCKADDR_IN6
146 else if (ss->ss_family == AF_INET6)
147 ((struct sockaddr_in6 *)ss)->sin6_port = htons(port);
148 #endif
149 }
150
151 /**
152 * add option to url of the form:
153 * "http://host:port/path?option1=val1&option2=val2...
154 */
155
url_add_option(char * buf,int buf_size,const char * fmt,...)156 static av_printf_format(3, 4) void url_add_option(char *buf, int buf_size, const char *fmt, ...)
157 {
158 char buf1[1024];
159 va_list ap;
160
161 va_start(ap, fmt);
162 if (strchr(buf, '?'))
163 av_strlcat(buf, "&", buf_size);
164 else
165 av_strlcat(buf, "?", buf_size);
166 vsnprintf(buf1, sizeof(buf1), fmt, ap);
167 av_strlcat(buf, buf1, buf_size);
168 va_end(ap);
169 }
170
build_udp_url(RTPContext * s,char * buf,int buf_size,const char * hostname,int port,int local_port,const char * include_sources,const char * exclude_sources)171 static void build_udp_url(RTPContext *s,
172 char *buf, int buf_size,
173 const char *hostname,
174 int port, int local_port,
175 const char *include_sources,
176 const char *exclude_sources)
177 {
178 ff_url_join(buf, buf_size, "udp", NULL, hostname, port, NULL);
179 if (local_port >= 0)
180 url_add_option(buf, buf_size, "localport=%d", local_port);
181 if (s->ttl >= 0)
182 url_add_option(buf, buf_size, "ttl=%d", s->ttl);
183 if (s->buffer_size >= 0)
184 url_add_option(buf, buf_size, "buffer_size=%d", s->buffer_size);
185 if (s->pkt_size >= 0)
186 url_add_option(buf, buf_size, "pkt_size=%d", s->pkt_size);
187 if (s->connect)
188 url_add_option(buf, buf_size, "connect=1");
189 if (s->dscp >= 0)
190 url_add_option(buf, buf_size, "dscp=%d", s->dscp);
191 url_add_option(buf, buf_size, "fifo_size=0");
192 if (include_sources && include_sources[0])
193 url_add_option(buf, buf_size, "sources=%s", include_sources);
194 if (exclude_sources && exclude_sources[0])
195 url_add_option(buf, buf_size, "block=%s", exclude_sources);
196 }
197
198 /**
199 * url syntax: rtp://host:port[?option=val...]
200 * option: 'ttl=n' : set the ttl value (for multicast only)
201 * 'rtcpport=n' : set the remote rtcp port to n
202 * 'localrtpport=n' : set the local rtp port to n
203 * 'localrtcpport=n' : set the local rtcp port to n
204 * 'pkt_size=n' : set max packet size
205 * 'connect=0/1' : do a connect() on the UDP socket
206 * 'sources=ip[,ip]' : list allowed source IP addresses
207 * 'block=ip[,ip]' : list disallowed source IP addresses
208 * 'write_to_source=0/1' : send packets to the source address of the latest received packet
209 * 'dscp=n' : set DSCP value to n (QoS)
210 * deprecated option:
211 * 'localport=n' : set the local port to n
212 *
213 * if rtcpport isn't set the rtcp port will be the rtp port + 1
214 * if local rtp port isn't set any available port will be used for the local
215 * rtp and rtcp ports
216 * if the local rtcp port is not set it will be the local rtp port + 1
217 */
218
rtp_open(URLContext * h,const char * uri,int flags)219 static int rtp_open(URLContext *h, const char *uri, int flags)
220 {
221 RTPContext *s = h->priv_data;
222 AVDictionary *fec_opts = NULL;
223 int rtp_port;
224 char hostname[256], include_sources[1024] = "", exclude_sources[1024] = "";
225 char *sources = include_sources, *block = exclude_sources;
226 char *fec_protocol = NULL;
227 char buf[1024];
228 char path[1024];
229 const char *p;
230 int i, max_retry_count = 3;
231 int rtcpflags;
232
233 av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port,
234 path, sizeof(path), uri);
235 /* extract parameters */
236 if (s->rtcp_port < 0)
237 s->rtcp_port = rtp_port + 1;
238
239 p = strchr(uri, '?');
240 if (p) {
241 if (av_find_info_tag(buf, sizeof(buf), "ttl", p)) {
242 s->ttl = strtol(buf, NULL, 10);
243 }
244 if (av_find_info_tag(buf, sizeof(buf), "rtcpport", p)) {
245 s->rtcp_port = strtol(buf, NULL, 10);
246 }
247 if (av_find_info_tag(buf, sizeof(buf), "localport", p)) {
248 s->local_rtpport = strtol(buf, NULL, 10);
249 }
250 if (av_find_info_tag(buf, sizeof(buf), "localrtpport", p)) {
251 s->local_rtpport = strtol(buf, NULL, 10);
252 }
253 if (av_find_info_tag(buf, sizeof(buf), "localrtcpport", p)) {
254 s->local_rtcpport = strtol(buf, NULL, 10);
255 }
256 if (av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
257 s->pkt_size = strtol(buf, NULL, 10);
258 }
259 if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
260 s->connect = strtol(buf, NULL, 10);
261 }
262 if (av_find_info_tag(buf, sizeof(buf), "write_to_source", p)) {
263 s->write_to_source = strtol(buf, NULL, 10);
264 }
265 if (av_find_info_tag(buf, sizeof(buf), "dscp", p)) {
266 s->dscp = strtol(buf, NULL, 10);
267 }
268 if (av_find_info_tag(buf, sizeof(buf), "sources", p)) {
269 av_strlcpy(include_sources, buf, sizeof(include_sources));
270 ff_ip_parse_sources(h, buf, &s->filters);
271 } else {
272 ff_ip_parse_sources(h, s->sources, &s->filters);
273 sources = s->sources;
274 }
275 if (av_find_info_tag(buf, sizeof(buf), "block", p)) {
276 av_strlcpy(exclude_sources, buf, sizeof(exclude_sources));
277 ff_ip_parse_blocks(h, buf, &s->filters);
278 } else {
279 ff_ip_parse_blocks(h, s->block, &s->filters);
280 block = s->block;
281 }
282 }
283
284 if (s->fec_options_str) {
285 p = s->fec_options_str;
286
287 if (!(fec_protocol = av_get_token(&p, "="))) {
288 av_log(h, AV_LOG_ERROR, "Failed to parse the FEC protocol value\n");
289 goto fail;
290 }
291 if (strcmp(fec_protocol, "prompeg")) {
292 av_log(h, AV_LOG_ERROR, "Unsupported FEC protocol %s\n", fec_protocol);
293 goto fail;
294 }
295
296 p = s->fec_options_str + strlen(fec_protocol);
297 while (*p && *p == '=') p++;
298
299 if (av_dict_parse_string(&fec_opts, p, "=", ":", 0) < 0) {
300 av_log(h, AV_LOG_ERROR, "Failed to parse the FEC options\n");
301 goto fail;
302 }
303 if (s->ttl > 0) {
304 av_dict_set_int(&fec_opts, "ttl", s->ttl, 0);
305 }
306 }
307
308 for (i = 0; i < max_retry_count; i++) {
309 build_udp_url(s, buf, sizeof(buf),
310 hostname, rtp_port, s->local_rtpport,
311 sources, block);
312 if (ffurl_open_whitelist(&s->rtp_hd, buf, flags, &h->interrupt_callback,
313 NULL, h->protocol_whitelist, h->protocol_blacklist, h) < 0)
314 goto fail;
315 s->local_rtpport = ff_udp_get_local_port(s->rtp_hd);
316 if(s->local_rtpport == 65535) {
317 s->local_rtpport = -1;
318 continue;
319 }
320 rtcpflags = flags | AVIO_FLAG_WRITE;
321 if (s->local_rtcpport < 0) {
322 s->local_rtcpport = s->local_rtpport + 1;
323 build_udp_url(s, buf, sizeof(buf),
324 hostname, s->rtcp_port, s->local_rtcpport,
325 sources, block);
326 if (ffurl_open_whitelist(&s->rtcp_hd, buf, rtcpflags,
327 &h->interrupt_callback, NULL,
328 h->protocol_whitelist, h->protocol_blacklist, h) < 0) {
329 s->local_rtpport = s->local_rtcpport = -1;
330 continue;
331 }
332 break;
333 }
334 build_udp_url(s, buf, sizeof(buf),
335 hostname, s->rtcp_port, s->local_rtcpport,
336 sources, block);
337 if (ffurl_open_whitelist(&s->rtcp_hd, buf, rtcpflags, &h->interrupt_callback,
338 NULL, h->protocol_whitelist, h->protocol_blacklist, h) < 0)
339 goto fail;
340 break;
341 }
342
343 s->fec_hd = NULL;
344 if (fec_protocol) {
345 ff_url_join(buf, sizeof(buf), fec_protocol, NULL, hostname, rtp_port, NULL);
346 if (ffurl_open_whitelist(&s->fec_hd, buf, flags, &h->interrupt_callback,
347 &fec_opts, h->protocol_whitelist, h->protocol_blacklist, h) < 0)
348 goto fail;
349 }
350
351 /* just to ease handle access. XXX: need to suppress direct handle
352 access */
353 s->rtp_fd = ffurl_get_file_handle(s->rtp_hd);
354 s->rtcp_fd = ffurl_get_file_handle(s->rtcp_hd);
355
356 h->max_packet_size = s->rtp_hd->max_packet_size;
357 h->is_streamed = 1;
358
359 av_free(fec_protocol);
360 av_dict_free(&fec_opts);
361
362 return 0;
363
364 fail:
365 ffurl_closep(&s->rtp_hd);
366 ffurl_closep(&s->rtcp_hd);
367 ffurl_closep(&s->fec_hd);
368 av_free(fec_protocol);
369 av_dict_free(&fec_opts);
370 return AVERROR(EIO);
371 }
372
rtp_read(URLContext * h,uint8_t * buf,int size)373 static int rtp_read(URLContext *h, uint8_t *buf, int size)
374 {
375 RTPContext *s = h->priv_data;
376 int len, n, i;
377 struct pollfd p[2] = {{s->rtp_fd, POLLIN, 0}, {s->rtcp_fd, POLLIN, 0}};
378 int poll_delay = h->flags & AVIO_FLAG_NONBLOCK ? 0 : 100;
379 struct sockaddr_storage *addrs[2] = { &s->last_rtp_source, &s->last_rtcp_source };
380 socklen_t *addr_lens[2] = { &s->last_rtp_source_len, &s->last_rtcp_source_len };
381
382 for(;;) {
383 if (ff_check_interrupt(&h->interrupt_callback))
384 return AVERROR_EXIT;
385 n = poll(p, 2, poll_delay);
386 if (n > 0) {
387 /* first try RTCP, then RTP */
388 for (i = 1; i >= 0; i--) {
389 if (!(p[i].revents & POLLIN))
390 continue;
391 *addr_lens[i] = sizeof(*addrs[i]);
392 len = recvfrom(p[i].fd, buf, size, 0,
393 (struct sockaddr *)addrs[i], addr_lens[i]);
394 if (len < 0) {
395 if (ff_neterrno() == AVERROR(EAGAIN) ||
396 ff_neterrno() == AVERROR(EINTR))
397 continue;
398 return AVERROR(EIO);
399 }
400 if (ff_ip_check_source_lists(addrs[i], &s->filters))
401 continue;
402 return len;
403 }
404 } else if (n < 0) {
405 if (ff_neterrno() == AVERROR(EINTR))
406 continue;
407 return AVERROR(EIO);
408 }
409 if (h->flags & AVIO_FLAG_NONBLOCK)
410 return AVERROR(EAGAIN);
411 }
412 }
413
rtp_write(URLContext * h,const uint8_t * buf,int size)414 static int rtp_write(URLContext *h, const uint8_t *buf, int size)
415 {
416 RTPContext *s = h->priv_data;
417 int ret, ret_fec;
418 URLContext *hd;
419
420 if (size < 2)
421 return AVERROR(EINVAL);
422
423 if ((buf[0] & 0xc0) != (RTP_VERSION << 6))
424 av_log(h, AV_LOG_WARNING, "Data doesn't look like RTP packets, "
425 "make sure the RTP muxer is used\n");
426
427 if (s->write_to_source) {
428 int fd;
429 struct sockaddr_storage *source, temp_source;
430 socklen_t *source_len, temp_len;
431 if (!s->last_rtp_source.ss_family && !s->last_rtcp_source.ss_family) {
432 av_log(h, AV_LOG_ERROR,
433 "Unable to send packet to source, no packets received yet\n");
434 // Intentionally not returning an error here
435 return size;
436 }
437
438 if (RTP_PT_IS_RTCP(buf[1])) {
439 fd = s->rtcp_fd;
440 source = &s->last_rtcp_source;
441 source_len = &s->last_rtcp_source_len;
442 } else {
443 fd = s->rtp_fd;
444 source = &s->last_rtp_source;
445 source_len = &s->last_rtp_source_len;
446 }
447 if (!source->ss_family) {
448 source = &temp_source;
449 source_len = &temp_len;
450 if (RTP_PT_IS_RTCP(buf[1])) {
451 temp_source = s->last_rtp_source;
452 temp_len = s->last_rtp_source_len;
453 set_port(source, get_port(source) + 1);
454 av_log(h, AV_LOG_INFO,
455 "Not received any RTCP packets yet, inferring peer port "
456 "from the RTP port\n");
457 } else {
458 temp_source = s->last_rtcp_source;
459 temp_len = s->last_rtcp_source_len;
460 set_port(source, get_port(source) - 1);
461 av_log(h, AV_LOG_INFO,
462 "Not received any RTP packets yet, inferring peer port "
463 "from the RTCP port\n");
464 }
465 }
466
467 if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
468 ret = ff_network_wait_fd(fd, 1);
469 if (ret < 0)
470 return ret;
471 }
472 ret = sendto(fd, buf, size, 0, (struct sockaddr *) source,
473 *source_len);
474
475 return ret < 0 ? ff_neterrno() : ret;
476 }
477
478 if (RTP_PT_IS_RTCP(buf[1])) {
479 /* RTCP payload type */
480 hd = s->rtcp_hd;
481 } else {
482 /* RTP payload type */
483 hd = s->rtp_hd;
484 }
485
486 if ((ret = ffurl_write(hd, buf, size)) < 0) {
487 return ret;
488 }
489
490 if (s->fec_hd && !RTP_PT_IS_RTCP(buf[1])) {
491 if ((ret_fec = ffurl_write(s->fec_hd, buf, size)) < 0) {
492 av_log(h, AV_LOG_ERROR, "Failed to send FEC\n");
493 return ret_fec;
494 }
495 }
496
497 return ret;
498 }
499
rtp_close(URLContext * h)500 static int rtp_close(URLContext *h)
501 {
502 RTPContext *s = h->priv_data;
503
504 ff_ip_reset_filters(&s->filters);
505
506 ffurl_closep(&s->rtp_hd);
507 ffurl_closep(&s->rtcp_hd);
508 ffurl_closep(&s->fec_hd);
509 return 0;
510 }
511
512 /**
513 * Return the local rtp port used by the RTP connection
514 * @param h media file context
515 * @return the local port number
516 */
517
ff_rtp_get_local_rtp_port(URLContext * h)518 int ff_rtp_get_local_rtp_port(URLContext *h)
519 {
520 RTPContext *s = h->priv_data;
521 return ff_udp_get_local_port(s->rtp_hd);
522 }
523
524 /**
525 * Return the local rtcp port used by the RTP connection
526 * @param h media file context
527 * @return the local port number
528 */
529
rtp_get_file_handle(URLContext * h)530 static int rtp_get_file_handle(URLContext *h)
531 {
532 RTPContext *s = h->priv_data;
533 return s->rtp_fd;
534 }
535
rtp_get_multi_file_handle(URLContext * h,int ** handles,int * numhandles)536 static int rtp_get_multi_file_handle(URLContext *h, int **handles,
537 int *numhandles)
538 {
539 RTPContext *s = h->priv_data;
540 int *hs = *handles = av_malloc(sizeof(**handles) * 2);
541 if (!hs)
542 return AVERROR(ENOMEM);
543 hs[0] = s->rtp_fd;
544 hs[1] = s->rtcp_fd;
545 *numhandles = 2;
546 return 0;
547 }
548
549 const URLProtocol ff_rtp_protocol = {
550 .name = "rtp",
551 .url_open = rtp_open,
552 .url_read = rtp_read,
553 .url_write = rtp_write,
554 .url_close = rtp_close,
555 .url_get_file_handle = rtp_get_file_handle,
556 .url_get_multi_file_handle = rtp_get_multi_file_handle,
557 .priv_data_size = sizeof(RTPContext),
558 .flags = URL_PROTOCOL_FLAG_NETWORK,
559 .priv_data_class = &rtp_class,
560 };
561