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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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/intreadwrite.h"
27 #include "internal.h"
28 #include "network.h"
29 #include "os_support.h"
30 #include "rtpenc_chain.h"
31 #include "url.h"
32 
33 struct SAPState {
34  uint8_t *ann;
35  int ann_size;
37  int64_t last_time;
38 };
39 
41 {
42  struct SAPState *sap = s->priv_data;
43  int i;
44 
45  for (i = 0; i < s->nb_streams; i++) {
46  AVFormatContext *rtpctx = s->streams[i]->priv_data;
47  if (!rtpctx)
48  continue;
49  av_write_trailer(rtpctx);
50  avio_close(rtpctx->pb);
51  avformat_free_context(rtpctx);
52  s->streams[i]->priv_data = NULL;
53  }
54 
55  if (sap->last_time && sap->ann && sap->ann_fd) {
56  sap->ann[0] |= 4; /* Session deletion*/
57  ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
58  }
59 
60  av_freep(&sap->ann);
61  if (sap->ann_fd)
62  ffurl_close(sap->ann_fd);
64  return 0;
65 }
66 
68 {
69  struct SAPState *sap = s->priv_data;
70  char host[1024], path[1024], url[1024], announce_addr[50] = "";
71  char *option_list;
72  int port = 9875, base_port = 5004, i, pos = 0, same_port = 0, ttl = 255;
73  AVFormatContext **contexts = NULL;
74  int ret = 0;
75  struct sockaddr_storage localaddr;
76  socklen_t addrlen = sizeof(localaddr);
77  int udp_fd;
78 
79  if (!ff_network_init())
80  return AVERROR(EIO);
81 
82  /* extract hostname and port */
83  av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &base_port,
84  path, sizeof(path), s->filename);
85  if (base_port < 0)
86  base_port = 5004;
87 
88  /* search for options */
89  option_list = strrchr(path, '?');
90  if (option_list) {
91  char buf[50];
92  if (av_find_info_tag(buf, sizeof(buf), "announce_port", option_list)) {
93  port = strtol(buf, NULL, 10);
94  }
95  if (av_find_info_tag(buf, sizeof(buf), "same_port", option_list)) {
96  same_port = strtol(buf, NULL, 10);
97  }
98  if (av_find_info_tag(buf, sizeof(buf), "ttl", option_list)) {
99  ttl = strtol(buf, NULL, 10);
100  }
101  if (av_find_info_tag(buf, sizeof(buf), "announce_addr", option_list)) {
102  av_strlcpy(announce_addr, buf, sizeof(announce_addr));
103  }
104  }
105 
106  if (!announce_addr[0]) {
107  struct addrinfo hints, *ai = NULL;
108  memset(&hints, 0, sizeof(hints));
109  hints.ai_family = AF_UNSPEC;
110  if (getaddrinfo(host, NULL, &hints, &ai)) {
111  av_log(s, AV_LOG_ERROR, "Unable to resolve %s\n", host);
112  ret = AVERROR(EIO);
113  goto fail;
114  }
115  if (ai->ai_family == AF_INET) {
116  /* Also known as sap.mcast.net */
117  av_strlcpy(announce_addr, "224.2.127.254", sizeof(announce_addr));
118 #if HAVE_STRUCT_SOCKADDR_IN6
119  } else if (ai->ai_family == AF_INET6) {
120  /* With IPv6, you can use the same destination in many different
121  * multicast subnets, to choose how far you want it routed.
122  * This one is intended to be routed globally. */
123  av_strlcpy(announce_addr, "ff0e::2:7ffe", sizeof(announce_addr));
124 #endif
125  } else {
126  freeaddrinfo(ai);
127  av_log(s, AV_LOG_ERROR, "Host %s resolved to unsupported "
128  "address family\n", host);
129  ret = AVERROR(EIO);
130  goto fail;
131  }
132  freeaddrinfo(ai);
133  }
134 
135  contexts = av_mallocz(sizeof(AVFormatContext*) * s->nb_streams);
136  if (!contexts) {
137  ret = AVERROR(ENOMEM);
138  goto fail;
139  }
140 
142  for (i = 0; i < s->nb_streams; i++) {
143  URLContext *fd;
144 
145  ff_url_join(url, sizeof(url), "rtp", NULL, host, base_port,
146  "?ttl=%d", ttl);
147  if (!same_port)
148  base_port += 2;
149  ret = ffurl_open(&fd, url, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
150  if (ret) {
151  ret = AVERROR(EIO);
152  goto fail;
153  }
154  s->streams[i]->priv_data = contexts[i] =
155  ff_rtp_chain_mux_open(s, s->streams[i], fd, 0);
156  av_strlcpy(contexts[i]->filename, url, sizeof(contexts[i]->filename));
157  }
158 
159  ff_url_join(url, sizeof(url), "udp", NULL, announce_addr, port,
160  "?ttl=%d&connect=1", ttl);
161  ret = ffurl_open(&sap->ann_fd, url, AVIO_FLAG_WRITE,
162  &s->interrupt_callback, NULL);
163  if (ret) {
164  ret = AVERROR(EIO);
165  goto fail;
166  }
167 
168  udp_fd = ffurl_get_file_handle(sap->ann_fd);
169  if (getsockname(udp_fd, (struct sockaddr*) &localaddr, &addrlen)) {
170  ret = AVERROR(EIO);
171  goto fail;
172  }
173  if (localaddr.ss_family != AF_INET
175  && localaddr.ss_family != AF_INET6
176 #endif
177  ) {
178  av_log(s, AV_LOG_ERROR, "Unsupported protocol family\n");
179  ret = AVERROR(EIO);
180  goto fail;
181  }
182  sap->ann_size = 8192;
183  sap->ann = av_mallocz(sap->ann_size);
184  if (!sap->ann) {
185  ret = AVERROR(EIO);
186  goto fail;
187  }
188  sap->ann[pos] = (1 << 5);
189 #if HAVE_STRUCT_SOCKADDR_IN6
190  if (localaddr.ss_family == AF_INET6)
191  sap->ann[pos] |= 0x10;
192 #endif
193  pos++;
194  sap->ann[pos++] = 0; /* Authentication length */
195  AV_WB16(&sap->ann[pos], av_get_random_seed());
196  pos += 2;
197  if (localaddr.ss_family == AF_INET) {
198  memcpy(&sap->ann[pos], &((struct sockaddr_in*)&localaddr)->sin_addr,
199  sizeof(struct in_addr));
200  pos += sizeof(struct in_addr);
201 #if HAVE_STRUCT_SOCKADDR_IN6
202  } else {
203  memcpy(&sap->ann[pos], &((struct sockaddr_in6*)&localaddr)->sin6_addr,
204  sizeof(struct in6_addr));
205  pos += sizeof(struct in6_addr);
206 #endif
207  }
208 
209  av_strlcpy(&sap->ann[pos], "application/sdp", sap->ann_size - pos);
210  pos += strlen(&sap->ann[pos]) + 1;
211 
212  if (av_sdp_create(contexts, s->nb_streams, &sap->ann[pos],
213  sap->ann_size - pos)) {
214  ret = AVERROR_INVALIDDATA;
215  goto fail;
216  }
217  av_freep(&contexts);
218  av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", &sap->ann[pos]);
219  pos += strlen(&sap->ann[pos]);
220  sap->ann_size = pos;
221 
222  if (sap->ann_size > sap->ann_fd->max_packet_size) {
223  av_log(s, AV_LOG_ERROR, "Announcement too large to send in one "
224  "packet\n");
225  goto fail;
226  }
227 
228  return 0;
229 
230 fail:
231  av_free(contexts);
232  sap_write_close(s);
233  return ret;
234 }
235 
237 {
238  AVFormatContext *rtpctx;
239  struct SAPState *sap = s->priv_data;
240  int64_t now = av_gettime();
241 
242  if (!sap->last_time || now - sap->last_time > 5000000) {
243  int ret = ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
244  /* Don't abort even if we get "Destination unreachable" */
245  if (ret < 0 && ret != AVERROR(ECONNREFUSED))
246  return ret;
247  sap->last_time = now;
248  }
249  rtpctx = s->streams[pkt->stream_index]->priv_data;
250  return ff_write_chained(rtpctx, 0, pkt, s);
251 }
252 
254  .name = "sap",
255  .long_name = NULL_IF_CONFIG_SMALL("SAP output format"),
256  .priv_data_size = sizeof(struct SAPState),
257  .audio_codec = CODEC_ID_AAC,
258  .video_codec = CODEC_ID_MPEG4,
259  .write_header = sap_write_header,
260  .write_packet = sap_write_packet,
261  .write_trailer = sap_write_close,
262  .flags = AVFMT_NOFILE | AVFMT_GLOBALHEADER,
263 };
264