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 int64_t rw_timeout;
64 } RTPContext;
65
66 #define OFFSET(x) offsetof(RTPContext, x)
67 #define D AV_OPT_FLAG_DECODING_PARAM
68 #define E AV_OPT_FLAG_ENCODING_PARAM
69 static const AVOption options[] = {
70 { "ttl", "Time to live (in milliseconds, multicast only)", OFFSET(ttl), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
71 { "buffer_size", "Send/Receive buffer size (in bytes)", OFFSET(buffer_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
72 { "rtcp_port", "Custom rtcp port", OFFSET(rtcp_port), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
73 { "local_rtpport", "Local rtp port", OFFSET(local_rtpport), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
74 { "local_rtcpport", "Local rtcp port", OFFSET(local_rtcpport), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
75 { "connect", "Connect socket", OFFSET(connect), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, .flags = D|E },
76 { "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 },
77 { "pkt_size", "Maximum packet size", OFFSET(pkt_size), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
78 { "dscp", "DSCP class", OFFSET(dscp), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, .flags = D|E },
79 { "timeout", "set timeout (in microseconds) of socket I/O operations", OFFSET(rw_timeout), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
80 { "sources", "Source list", OFFSET(sources), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = D|E },
81 { "block", "Block list", OFFSET(block), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = D|E },
82 { "fec", "FEC", OFFSET(fec_options_str), AV_OPT_TYPE_STRING, { .str = NULL }, .flags = E },
83 { NULL }
84 };
85
86 static const AVClass rtp_class = {
87 .class_name = "rtp",
88 .item_name = av_default_item_name,
89 .option = options,
90 .version = LIBAVUTIL_VERSION_INT,
91 };
92
93 /**
94 * If no filename is given to av_open_input_file because you want to
95 * get the local port first, then you must call this function to set
96 * the remote server address.
97 *
98 * @param h media file context
99 * @param uri of the remote server
100 * @return zero if no error.
101 */
102
ff_rtp_set_remote_url(URLContext * h,const char * uri)103 int ff_rtp_set_remote_url(URLContext *h, const char *uri)
104 {
105 RTPContext *s = h->priv_data;
106 char hostname[256];
107 int port, rtcp_port;
108 const char *p;
109
110 char buf[1024];
111 char path[1024];
112
113 av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
114 path, sizeof(path), uri);
115 rtcp_port = port + 1;
116
117 p = strchr(uri, '?');
118 if (p) {
119 if (av_find_info_tag(buf, sizeof(buf), "rtcpport", p)) {
120 rtcp_port = strtol(buf, NULL, 10);
121 }
122 }
123
124 ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, port, "%s", path);
125 ff_udp_set_remote_url(s->rtp_hd, buf);
126
127 ff_url_join(buf, sizeof(buf), "udp", NULL, hostname, rtcp_port, "%s", path);
128 ff_udp_set_remote_url(s->rtcp_hd, buf);
129 return 0;
130 }
131
get_port(const struct sockaddr_storage * ss)132 static int get_port(const struct sockaddr_storage *ss)
133 {
134 if (ss->ss_family == AF_INET)
135 return ntohs(((const struct sockaddr_in *)ss)->sin_port);
136 #if HAVE_STRUCT_SOCKADDR_IN6
137 if (ss->ss_family == AF_INET6)
138 return ntohs(((const struct sockaddr_in6 *)ss)->sin6_port);
139 #endif
140 return 0;
141 }
142
set_port(struct sockaddr_storage * ss,int port)143 static void set_port(struct sockaddr_storage *ss, int port)
144 {
145 if (ss->ss_family == AF_INET)
146 ((struct sockaddr_in *)ss)->sin_port = htons(port);
147 #if HAVE_STRUCT_SOCKADDR_IN6
148 else if (ss->ss_family == AF_INET6)
149 ((struct sockaddr_in6 *)ss)->sin6_port = htons(port);
150 #endif
151 }
152
153 /**
154 * add option to url of the form:
155 * "http://host:port/path?option1=val1&option2=val2...
156 */
157
url_add_option(char * buf,int buf_size,const char * fmt,...)158 static av_printf_format(3, 4) void url_add_option(char *buf, int buf_size, const char *fmt, ...)
159 {
160 char buf1[1024];
161 va_list ap;
162
163 va_start(ap, fmt);
164 if (strchr(buf, '?'))
165 av_strlcat(buf, "&", buf_size);
166 else
167 av_strlcat(buf, "?", buf_size);
168 vsnprintf(buf1, sizeof(buf1), fmt, ap);
169 av_strlcat(buf, buf1, buf_size);
170 va_end(ap);
171 }
172
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)173 static void build_udp_url(RTPContext *s,
174 char *buf, int buf_size,
175 const char *hostname,
176 int port, int local_port,
177 const char *include_sources,
178 const char *exclude_sources)
179 {
180 ff_url_join(buf, buf_size, "udp", NULL, hostname, port, NULL);
181 if (local_port >= 0)
182 url_add_option(buf, buf_size, "localport=%d", local_port);
183 if (s->ttl >= 0)
184 url_add_option(buf, buf_size, "ttl=%d", s->ttl);
185 if (s->buffer_size >= 0)
186 url_add_option(buf, buf_size, "buffer_size=%d", s->buffer_size);
187 if (s->pkt_size >= 0)
188 url_add_option(buf, buf_size, "pkt_size=%d", s->pkt_size);
189 if (s->connect)
190 url_add_option(buf, buf_size, "connect=1");
191 if (s->dscp >= 0)
192 url_add_option(buf, buf_size, "dscp=%d", s->dscp);
193 url_add_option(buf, buf_size, "fifo_size=0");
194 if (include_sources && include_sources[0])
195 url_add_option(buf, buf_size, "sources=%s", include_sources);
196 if (exclude_sources && exclude_sources[0])
197 url_add_option(buf, buf_size, "block=%s", exclude_sources);
198 }
199
200 /**
201 * url syntax: rtp://host:port[?option=val...]
202 * option: 'ttl=n' : set the ttl value (for multicast only)
203 * 'rtcpport=n' : set the remote rtcp port to n
204 * 'localrtpport=n' : set the local rtp port to n
205 * 'localrtcpport=n' : set the local rtcp port to n
206 * 'pkt_size=n' : set max packet size
207 * 'connect=0/1' : do a connect() on the UDP socket
208 * 'sources=ip[,ip]' : list allowed source IP addresses
209 * 'block=ip[,ip]' : list disallowed source IP addresses
210 * 'write_to_source=0/1' : send packets to the source address of the latest received packet
211 * 'dscp=n' : set DSCP value to n (QoS)
212 * deprecated option:
213 * 'localport=n' : set the local port to n
214 *
215 * if rtcpport isn't set the rtcp port will be the rtp port + 1
216 * if local rtp port isn't set any available port will be used for the local
217 * rtp and rtcp ports
218 * if the local rtcp port is not set it will be the local rtp port + 1
219 */
220
rtp_open(URLContext * h,const char * uri,int flags)221 static int rtp_open(URLContext *h, const char *uri, int flags)
222 {
223 RTPContext *s = h->priv_data;
224 AVDictionary *fec_opts = NULL;
225 int rtp_port;
226 char hostname[256], include_sources[1024] = "", exclude_sources[1024] = "";
227 char *sources = include_sources, *block = exclude_sources;
228 char *fec_protocol = NULL;
229 char buf[1024];
230 char path[1024];
231 const char *p;
232 int i, max_retry_count = 3;
233 int rtcpflags;
234
235 av_url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &rtp_port,
236 path, sizeof(path), uri);
237 /* extract parameters */
238 if (s->rtcp_port < 0)
239 s->rtcp_port = rtp_port + 1;
240
241 p = strchr(uri, '?');
242 if (p) {
243 if (av_find_info_tag(buf, sizeof(buf), "ttl", p)) {
244 s->ttl = strtol(buf, NULL, 10);
245 }
246 if (av_find_info_tag(buf, sizeof(buf), "rtcpport", p)) {
247 s->rtcp_port = strtol(buf, NULL, 10);
248 }
249 if (av_find_info_tag(buf, sizeof(buf), "localport", p)) {
250 s->local_rtpport = strtol(buf, NULL, 10);
251 }
252 if (av_find_info_tag(buf, sizeof(buf), "localrtpport", p)) {
253 s->local_rtpport = strtol(buf, NULL, 10);
254 }
255 if (av_find_info_tag(buf, sizeof(buf), "localrtcpport", p)) {
256 s->local_rtcpport = strtol(buf, NULL, 10);
257 }
258 if (av_find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
259 s->pkt_size = strtol(buf, NULL, 10);
260 }
261 if (av_find_info_tag(buf, sizeof(buf), "connect", p)) {
262 s->connect = strtol(buf, NULL, 10);
263 }
264 if (av_find_info_tag(buf, sizeof(buf), "write_to_source", p)) {
265 s->write_to_source = strtol(buf, NULL, 10);
266 }
267 if (av_find_info_tag(buf, sizeof(buf), "dscp", p)) {
268 s->dscp = strtol(buf, NULL, 10);
269 }
270 if (av_find_info_tag(buf, sizeof(buf), "timeout", p)) {
271 s->rw_timeout = strtol(buf, NULL, 10);
272 }
273 if (av_find_info_tag(buf, sizeof(buf), "sources", p)) {
274 av_strlcpy(include_sources, buf, sizeof(include_sources));
275 ff_ip_parse_sources(h, buf, &s->filters);
276 } else {
277 ff_ip_parse_sources(h, s->sources, &s->filters);
278 sources = s->sources;
279 }
280 if (av_find_info_tag(buf, sizeof(buf), "block", p)) {
281 av_strlcpy(exclude_sources, buf, sizeof(exclude_sources));
282 ff_ip_parse_blocks(h, buf, &s->filters);
283 } else {
284 ff_ip_parse_blocks(h, s->block, &s->filters);
285 block = s->block;
286 }
287 }
288 if (s->rw_timeout >= 0)
289 h->rw_timeout = s->rw_timeout;
290
291 if (s->fec_options_str) {
292 p = s->fec_options_str;
293
294 if (!(fec_protocol = av_get_token(&p, "="))) {
295 av_log(h, AV_LOG_ERROR, "Failed to parse the FEC protocol value\n");
296 goto fail;
297 }
298 if (strcmp(fec_protocol, "prompeg")) {
299 av_log(h, AV_LOG_ERROR, "Unsupported FEC protocol %s\n", fec_protocol);
300 goto fail;
301 }
302
303 p = s->fec_options_str + strlen(fec_protocol);
304 while (*p && *p == '=') p++;
305
306 if (av_dict_parse_string(&fec_opts, p, "=", ":", 0) < 0) {
307 av_log(h, AV_LOG_ERROR, "Failed to parse the FEC options\n");
308 goto fail;
309 }
310 if (s->ttl > 0) {
311 av_dict_set_int(&fec_opts, "ttl", s->ttl, 0);
312 }
313 }
314
315 for (i = 0; i < max_retry_count; i++) {
316 build_udp_url(s, buf, sizeof(buf),
317 hostname, rtp_port, s->local_rtpport,
318 sources, block);
319 if (ffurl_open_whitelist(&s->rtp_hd, buf, flags, &h->interrupt_callback,
320 NULL, h->protocol_whitelist, h->protocol_blacklist, h) < 0)
321 goto fail;
322 s->local_rtpport = ff_udp_get_local_port(s->rtp_hd);
323 if(s->local_rtpport == 65535) {
324 s->local_rtpport = -1;
325 continue;
326 }
327 rtcpflags = flags | AVIO_FLAG_WRITE;
328 if (s->local_rtcpport < 0) {
329 s->local_rtcpport = s->local_rtpport + 1;
330 build_udp_url(s, buf, sizeof(buf),
331 hostname, s->rtcp_port, s->local_rtcpport,
332 sources, block);
333 if (ffurl_open_whitelist(&s->rtcp_hd, buf, rtcpflags,
334 &h->interrupt_callback, NULL,
335 h->protocol_whitelist, h->protocol_blacklist, h) < 0) {
336 s->local_rtpport = s->local_rtcpport = -1;
337 continue;
338 }
339 break;
340 }
341 build_udp_url(s, buf, sizeof(buf),
342 hostname, s->rtcp_port, s->local_rtcpport,
343 sources, block);
344 if (ffurl_open_whitelist(&s->rtcp_hd, buf, rtcpflags, &h->interrupt_callback,
345 NULL, h->protocol_whitelist, h->protocol_blacklist, h) < 0)
346 goto fail;
347 break;
348 }
349
350 s->fec_hd = NULL;
351 if (fec_protocol) {
352 ff_url_join(buf, sizeof(buf), fec_protocol, NULL, hostname, rtp_port, NULL);
353 if (ffurl_open_whitelist(&s->fec_hd, buf, flags, &h->interrupt_callback,
354 &fec_opts, h->protocol_whitelist, h->protocol_blacklist, h) < 0)
355 goto fail;
356 }
357
358 /* just to ease handle access. XXX: need to suppress direct handle
359 access */
360 s->rtp_fd = ffurl_get_file_handle(s->rtp_hd);
361 s->rtcp_fd = ffurl_get_file_handle(s->rtcp_hd);
362
363 h->max_packet_size = s->rtp_hd->max_packet_size;
364 h->is_streamed = 1;
365
366 av_free(fec_protocol);
367 av_dict_free(&fec_opts);
368
369 return 0;
370
371 fail:
372 ffurl_closep(&s->rtp_hd);
373 ffurl_closep(&s->rtcp_hd);
374 ffurl_closep(&s->fec_hd);
375 av_free(fec_protocol);
376 av_dict_free(&fec_opts);
377 return AVERROR(EIO);
378 }
379
rtp_read(URLContext * h,uint8_t * buf,int size)380 static int rtp_read(URLContext *h, uint8_t *buf, int size)
381 {
382 RTPContext *s = h->priv_data;
383 int len, n, i;
384 struct pollfd p[2] = {{s->rtp_fd, POLLIN, 0}, {s->rtcp_fd, POLLIN, 0}};
385 int poll_delay = h->flags & AVIO_FLAG_NONBLOCK ? 0 : POLLING_TIME;
386 struct sockaddr_storage *addrs[2] = { &s->last_rtp_source, &s->last_rtcp_source };
387 socklen_t *addr_lens[2] = { &s->last_rtp_source_len, &s->last_rtcp_source_len };
388 int runs = h->rw_timeout / 1000 / POLLING_TIME;
389
390 for(;;) {
391 if (ff_check_interrupt(&h->interrupt_callback))
392 return AVERROR_EXIT;
393 n = poll(p, 2, poll_delay);
394 if (n > 0) {
395 /* first try RTCP, then RTP */
396 for (i = 1; i >= 0; i--) {
397 if (!(p[i].revents & POLLIN))
398 continue;
399 *addr_lens[i] = sizeof(*addrs[i]);
400 len = recvfrom(p[i].fd, buf, size, 0,
401 (struct sockaddr *)addrs[i], addr_lens[i]);
402 if (len < 0) {
403 if (ff_neterrno() == AVERROR(EAGAIN) ||
404 ff_neterrno() == AVERROR(EINTR))
405 continue;
406 return AVERROR(EIO);
407 }
408 if (ff_ip_check_source_lists(addrs[i], &s->filters))
409 continue;
410 return len;
411 }
412 } else if (n == 0 && h->rw_timeout > 0 && --runs <= 0) {
413 return AVERROR(ETIMEDOUT);
414 } else if (n < 0) {
415 if (ff_neterrno() == AVERROR(EINTR))
416 continue;
417 return AVERROR(EIO);
418 }
419 if (h->flags & AVIO_FLAG_NONBLOCK)
420 return AVERROR(EAGAIN);
421 }
422 }
423
rtp_write(URLContext * h,const uint8_t * buf,int size)424 static int rtp_write(URLContext *h, const uint8_t *buf, int size)
425 {
426 RTPContext *s = h->priv_data;
427 int ret, ret_fec;
428 URLContext *hd;
429
430 if (size < 2)
431 return AVERROR(EINVAL);
432
433 if ((buf[0] & 0xc0) != (RTP_VERSION << 6))
434 av_log(h, AV_LOG_WARNING, "Data doesn't look like RTP packets, "
435 "make sure the RTP muxer is used\n");
436
437 if (s->write_to_source) {
438 int fd;
439 struct sockaddr_storage *source, temp_source;
440 socklen_t *source_len, temp_len;
441 if (!s->last_rtp_source.ss_family && !s->last_rtcp_source.ss_family) {
442 av_log(h, AV_LOG_ERROR,
443 "Unable to send packet to source, no packets received yet\n");
444 // Intentionally not returning an error here
445 return size;
446 }
447
448 if (RTP_PT_IS_RTCP(buf[1])) {
449 fd = s->rtcp_fd;
450 source = &s->last_rtcp_source;
451 source_len = &s->last_rtcp_source_len;
452 } else {
453 fd = s->rtp_fd;
454 source = &s->last_rtp_source;
455 source_len = &s->last_rtp_source_len;
456 }
457 if (!source->ss_family) {
458 source = &temp_source;
459 source_len = &temp_len;
460 if (RTP_PT_IS_RTCP(buf[1])) {
461 temp_source = s->last_rtp_source;
462 temp_len = s->last_rtp_source_len;
463 set_port(source, get_port(source) + 1);
464 av_log(h, AV_LOG_INFO,
465 "Not received any RTCP packets yet, inferring peer port "
466 "from the RTP port\n");
467 } else {
468 temp_source = s->last_rtcp_source;
469 temp_len = s->last_rtcp_source_len;
470 set_port(source, get_port(source) - 1);
471 av_log(h, AV_LOG_INFO,
472 "Not received any RTP packets yet, inferring peer port "
473 "from the RTCP port\n");
474 }
475 }
476
477 if (!(h->flags & AVIO_FLAG_NONBLOCK)) {
478 ret = ff_network_wait_fd(fd, 1);
479 if (ret < 0)
480 return ret;
481 }
482 ret = sendto(fd, buf, size, 0, (struct sockaddr *) source,
483 *source_len);
484
485 return ret < 0 ? ff_neterrno() : ret;
486 }
487
488 if (RTP_PT_IS_RTCP(buf[1])) {
489 /* RTCP payload type */
490 hd = s->rtcp_hd;
491 } else {
492 /* RTP payload type */
493 hd = s->rtp_hd;
494 }
495
496 if ((ret = ffurl_write(hd, buf, size)) < 0) {
497 return ret;
498 }
499
500 if (s->fec_hd && !RTP_PT_IS_RTCP(buf[1])) {
501 if ((ret_fec = ffurl_write(s->fec_hd, buf, size)) < 0) {
502 av_log(h, AV_LOG_ERROR, "Failed to send FEC\n");
503 return ret_fec;
504 }
505 }
506
507 return ret;
508 }
509
rtp_close(URLContext * h)510 static int rtp_close(URLContext *h)
511 {
512 RTPContext *s = h->priv_data;
513
514 ff_ip_reset_filters(&s->filters);
515
516 ffurl_closep(&s->rtp_hd);
517 ffurl_closep(&s->rtcp_hd);
518 ffurl_closep(&s->fec_hd);
519 return 0;
520 }
521
522 /**
523 * Return the local rtp port used by the RTP connection
524 * @param h media file context
525 * @return the local port number
526 */
527
ff_rtp_get_local_rtp_port(URLContext * h)528 int ff_rtp_get_local_rtp_port(URLContext *h)
529 {
530 RTPContext *s = h->priv_data;
531 return ff_udp_get_local_port(s->rtp_hd);
532 }
533
534 /**
535 * Return the local rtcp port used by the RTP connection
536 * @param h media file context
537 * @return the local port number
538 */
539
rtp_get_file_handle(URLContext * h)540 static int rtp_get_file_handle(URLContext *h)
541 {
542 RTPContext *s = h->priv_data;
543 return s->rtp_fd;
544 }
545
rtp_get_multi_file_handle(URLContext * h,int ** handles,int * numhandles)546 static int rtp_get_multi_file_handle(URLContext *h, int **handles,
547 int *numhandles)
548 {
549 RTPContext *s = h->priv_data;
550 int *hs = *handles = av_malloc(sizeof(**handles) * 2);
551 if (!hs)
552 return AVERROR(ENOMEM);
553 hs[0] = s->rtp_fd;
554 hs[1] = s->rtcp_fd;
555 *numhandles = 2;
556 return 0;
557 }
558
559 const URLProtocol ff_rtp_protocol = {
560 .name = "rtp",
561 .url_open = rtp_open,
562 .url_read = rtp_read,
563 .url_write = rtp_write,
564 .url_close = rtp_close,
565 .url_get_file_handle = rtp_get_file_handle,
566 .url_get_multi_file_handle = rtp_get_multi_file_handle,
567 .priv_data_size = sizeof(RTPContext),
568 .flags = URL_PROTOCOL_FLAG_NETWORK,
569 .priv_data_class = &rtp_class,
570 };
571