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sapenc.c
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1 /*
2  * Session Announcement Protocol (RFC 2974) muxer
3  * Copyright (c) 2010 Martin Storsjo
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 #include "avformat.h"
23 #include "libavutil/parseutils.h"
24 #include "libavutil/random_seed.h"
25 #include "libavutil/avstring.h"
26 #include "libavutil/dict.h"
27 #include "libavutil/intreadwrite.h"
28 #include "libavutil/time.h"
29 #include "internal.h"
30 #include "network.h"
31 #include "os_support.h"
32 #include "rtpenc_chain.h"
33 #include "url.h"
34 
35 struct SAPState {
37  int ann_size;
39  int64_t last_time;
40 };
41 
43 {
44  struct SAPState *sap = s->priv_data;
45  int i;
46 
47  for (i = 0; i < s->nb_streams; i++) {
48  AVFormatContext *rtpctx = s->streams[i]->priv_data;
49  if (!rtpctx)
50  continue;
51  av_write_trailer(rtpctx);
52  avio_close(rtpctx->pb);
53  avformat_free_context(rtpctx);
54  s->streams[i]->priv_data = NULL;
55  }
56 
57  if (sap->last_time && sap->ann && sap->ann_fd) {
58  sap->ann[0] |= 4; /* Session deletion*/
59  ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
60  }
61 
62  av_freep(&sap->ann);
63  if (sap->ann_fd)
64  ffurl_close(sap->ann_fd);
66  return 0;
67 }
68 
70 {
71  struct SAPState *sap = s->priv_data;
72  char host[1024], path[1024], url[1024], announce_addr[50] = "";
73  char *option_list;
74  int port = 9875, base_port = 5004, i, pos = 0, same_port = 0, ttl = 255;
75  AVFormatContext **contexts = NULL;
76  int ret = 0;
77  struct sockaddr_storage localaddr;
78  socklen_t addrlen = sizeof(localaddr);
79  int udp_fd;
80  AVDictionaryEntry* title = av_dict_get(s->metadata, "title", NULL, 0);
81 
82  if (!ff_network_init())
83  return AVERROR(EIO);
84 
85  /* extract hostname and port */
86  av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &base_port,
87  path, sizeof(path), s->filename);
88  if (base_port < 0)
89  base_port = 5004;
90 
91  /* search for options */
92  option_list = strrchr(path, '?');
93  if (option_list) {
94  char buf[50];
95  if (av_find_info_tag(buf, sizeof(buf), "announce_port", option_list)) {
96  port = strtol(buf, NULL, 10);
97  }
98  if (av_find_info_tag(buf, sizeof(buf), "same_port", option_list)) {
99  same_port = strtol(buf, NULL, 10);
100  }
101  if (av_find_info_tag(buf, sizeof(buf), "ttl", option_list)) {
102  ttl = strtol(buf, NULL, 10);
103  }
104  if (av_find_info_tag(buf, sizeof(buf), "announce_addr", option_list)) {
105  av_strlcpy(announce_addr, buf, sizeof(announce_addr));
106  }
107  }
108 
109  if (!announce_addr[0]) {
110  struct addrinfo hints = { 0 }, *ai = NULL;
111  hints.ai_family = AF_UNSPEC;
112  if (getaddrinfo(host, NULL, &hints, &ai)) {
113  av_log(s, AV_LOG_ERROR, "Unable to resolve %s\n", host);
114  ret = AVERROR(EIO);
115  goto fail;
116  }
117  if (ai->ai_family == AF_INET) {
118  /* Also known as sap.mcast.net */
119  av_strlcpy(announce_addr, "224.2.127.254", sizeof(announce_addr));
120 #if HAVE_STRUCT_SOCKADDR_IN6
121  } else if (ai->ai_family == AF_INET6) {
122  /* With IPv6, you can use the same destination in many different
123  * multicast subnets, to choose how far you want it routed.
124  * This one is intended to be routed globally. */
125  av_strlcpy(announce_addr, "ff0e::2:7ffe", sizeof(announce_addr));
126 #endif
127  } else {
128  freeaddrinfo(ai);
129  av_log(s, AV_LOG_ERROR, "Host %s resolved to unsupported "
130  "address family\n", host);
131  ret = AVERROR(EIO);
132  goto fail;
133  }
134  freeaddrinfo(ai);
135  }
136 
137  contexts = av_mallocz(sizeof(AVFormatContext*) * s->nb_streams);
138  if (!contexts) {
139  ret = AVERROR(ENOMEM);
140  goto fail;
141  }
142 
144  for (i = 0; i < s->nb_streams; i++) {
145  URLContext *fd;
146 
147  ff_url_join(url, sizeof(url), "rtp", NULL, host, base_port,
148  "?ttl=%d", ttl);
149  if (!same_port)
150  base_port += 2;
151  ret = ffurl_open(&fd, url, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
152  if (ret) {
153  ret = AVERROR(EIO);
154  goto fail;
155  }
156  ret = ff_rtp_chain_mux_open(&contexts[i], s, s->streams[i], fd, 0, i);
157  if (ret < 0)
158  goto fail;
159  s->streams[i]->priv_data = contexts[i];
160  av_strlcpy(contexts[i]->filename, url, sizeof(contexts[i]->filename));
161  }
162 
163  if (s->nb_streams > 0 && title)
164  av_dict_set(&contexts[0]->metadata, "title", title->value, 0);
165 
166  ff_url_join(url, sizeof(url), "udp", NULL, announce_addr, port,
167  "?ttl=%d&connect=1", ttl);
168  ret = ffurl_open(&sap->ann_fd, url, AVIO_FLAG_WRITE,
169  &s->interrupt_callback, NULL);
170  if (ret) {
171  ret = AVERROR(EIO);
172  goto fail;
173  }
174 
175  udp_fd = ffurl_get_file_handle(sap->ann_fd);
176  if (getsockname(udp_fd, (struct sockaddr*) &localaddr, &addrlen)) {
177  ret = AVERROR(EIO);
178  goto fail;
179  }
180  if (localaddr.ss_family != AF_INET
181 #if HAVE_STRUCT_SOCKADDR_IN6
182  && localaddr.ss_family != AF_INET6
183 #endif
184  ) {
185  av_log(s, AV_LOG_ERROR, "Unsupported protocol family\n");
186  ret = AVERROR(EIO);
187  goto fail;
188  }
189  sap->ann_size = 8192;
190  sap->ann = av_mallocz(sap->ann_size);
191  if (!sap->ann) {
192  ret = AVERROR(EIO);
193  goto fail;
194  }
195  sap->ann[pos] = (1 << 5);
196 #if HAVE_STRUCT_SOCKADDR_IN6
197  if (localaddr.ss_family == AF_INET6)
198  sap->ann[pos] |= 0x10;
199 #endif
200  pos++;
201  sap->ann[pos++] = 0; /* Authentication length */
202  AV_WB16(&sap->ann[pos], av_get_random_seed());
203  pos += 2;
204  if (localaddr.ss_family == AF_INET) {
205  memcpy(&sap->ann[pos], &((struct sockaddr_in*)&localaddr)->sin_addr,
206  sizeof(struct in_addr));
207  pos += sizeof(struct in_addr);
208 #if HAVE_STRUCT_SOCKADDR_IN6
209  } else {
210  memcpy(&sap->ann[pos], &((struct sockaddr_in6*)&localaddr)->sin6_addr,
211  sizeof(struct in6_addr));
212  pos += sizeof(struct in6_addr);
213 #endif
214  }
215 
216  av_strlcpy(&sap->ann[pos], "application/sdp", sap->ann_size - pos);
217  pos += strlen(&sap->ann[pos]) + 1;
218 
219  if (av_sdp_create(contexts, s->nb_streams, &sap->ann[pos],
220  sap->ann_size - pos)) {
221  ret = AVERROR_INVALIDDATA;
222  goto fail;
223  }
224  av_freep(&contexts);
225  av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", &sap->ann[pos]);
226  pos += strlen(&sap->ann[pos]);
227  sap->ann_size = pos;
228 
229  if (sap->ann_size > sap->ann_fd->max_packet_size) {
230  av_log(s, AV_LOG_ERROR, "Announcement too large to send in one "
231  "packet\n");
232  goto fail;
233  }
234 
235  return 0;
236 
237 fail:
238  av_free(contexts);
239  sap_write_close(s);
240  return ret;
241 }
242 
244 {
245  AVFormatContext *rtpctx;
246  struct SAPState *sap = s->priv_data;
247  int64_t now = av_gettime();
248 
249  if (!sap->last_time || now - sap->last_time > 5000000) {
250  int ret = ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
251  /* Don't abort even if we get "Destination unreachable" */
252  if (ret < 0 && ret != AVERROR(ECONNREFUSED))
253  return ret;
254  sap->last_time = now;
255  }
256  rtpctx = s->streams[pkt->stream_index]->priv_data;
257  return ff_write_chained(rtpctx, 0, pkt, s);
258 }
259 
261  .name = "sap",
262  .long_name = NULL_IF_CONFIG_SMALL("SAP output"),
263  .priv_data_size = sizeof(struct SAPState),
264  .audio_codec = AV_CODEC_ID_AAC,
265  .video_codec = AV_CODEC_ID_MPEG4,
266  .write_header = sap_write_header,
267  .write_packet = sap_write_packet,
268  .write_trailer = sap_write_close,
269  .flags = AVFMT_NOFILE | AVFMT_GLOBALHEADER,
270 };