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2ba45a60 DM |
1 | /* |
2 | * Session Announcement Protocol (RFC 2974) demuxer | |
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" | |
f6fa7814 | 23 | #include "libavutil/avassert.h" |
2ba45a60 DM |
24 | #include "libavutil/avstring.h" |
25 | #include "libavutil/intreadwrite.h" | |
26 | #include "network.h" | |
27 | #include "os_support.h" | |
28 | #include "internal.h" | |
29 | #include "avio_internal.h" | |
30 | #include "url.h" | |
31 | #include "rtpdec.h" | |
32 | #if HAVE_POLL_H | |
33 | #include <poll.h> | |
34 | #endif | |
35 | ||
36 | struct SAPState { | |
37 | URLContext *ann_fd; | |
38 | AVFormatContext *sdp_ctx; | |
39 | AVIOContext sdp_pb; | |
40 | uint16_t hash; | |
41 | char *sdp; | |
42 | int eof; | |
43 | }; | |
44 | ||
45 | static int sap_probe(AVProbeData *p) | |
46 | { | |
47 | if (av_strstart(p->filename, "sap:", NULL)) | |
48 | return AVPROBE_SCORE_MAX; | |
49 | return 0; | |
50 | } | |
51 | ||
52 | static int sap_read_close(AVFormatContext *s) | |
53 | { | |
54 | struct SAPState *sap = s->priv_data; | |
55 | if (sap->sdp_ctx) | |
56 | avformat_close_input(&sap->sdp_ctx); | |
57 | if (sap->ann_fd) | |
58 | ffurl_close(sap->ann_fd); | |
59 | av_freep(&sap->sdp); | |
60 | ff_network_close(); | |
61 | return 0; | |
62 | } | |
63 | ||
64 | static int sap_read_header(AVFormatContext *s) | |
65 | { | |
66 | struct SAPState *sap = s->priv_data; | |
67 | char host[1024], path[1024], url[1024]; | |
68 | uint8_t recvbuf[RTP_MAX_PACKET_LENGTH]; | |
69 | int port; | |
70 | int ret, i; | |
71 | AVInputFormat* infmt; | |
72 | ||
73 | if (!ff_network_init()) | |
74 | return AVERROR(EIO); | |
75 | ||
76 | av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port, | |
77 | path, sizeof(path), s->filename); | |
78 | if (port < 0) | |
79 | port = 9875; | |
80 | ||
81 | if (!host[0]) { | |
82 | /* Listen for announcements on sap.mcast.net if no host was specified */ | |
83 | av_strlcpy(host, "224.2.127.254", sizeof(host)); | |
84 | } | |
85 | ||
86 | ff_url_join(url, sizeof(url), "udp", NULL, host, port, "?localport=%d", | |
87 | port); | |
88 | ret = ffurl_open(&sap->ann_fd, url, AVIO_FLAG_READ, | |
89 | &s->interrupt_callback, NULL); | |
90 | if (ret) | |
91 | goto fail; | |
92 | ||
93 | while (1) { | |
94 | int addr_type, auth_len; | |
95 | int pos; | |
96 | ||
97 | ret = ffurl_read(sap->ann_fd, recvbuf, sizeof(recvbuf) - 1); | |
98 | if (ret == AVERROR(EAGAIN)) | |
99 | continue; | |
100 | if (ret < 0) | |
101 | goto fail; | |
102 | recvbuf[ret] = '\0'; /* Null terminate for easier parsing */ | |
103 | if (ret < 8) { | |
104 | av_log(s, AV_LOG_WARNING, "Received too short packet\n"); | |
105 | continue; | |
106 | } | |
107 | ||
108 | if ((recvbuf[0] & 0xe0) != 0x20) { | |
109 | av_log(s, AV_LOG_WARNING, "Unsupported SAP version packet " | |
110 | "received\n"); | |
111 | continue; | |
112 | } | |
113 | ||
114 | if (recvbuf[0] & 0x04) { | |
115 | av_log(s, AV_LOG_WARNING, "Received stream deletion " | |
116 | "announcement\n"); | |
117 | continue; | |
118 | } | |
119 | addr_type = recvbuf[0] & 0x10; | |
120 | auth_len = recvbuf[1]; | |
121 | sap->hash = AV_RB16(&recvbuf[2]); | |
122 | pos = 4; | |
123 | if (addr_type) | |
124 | pos += 16; /* IPv6 */ | |
125 | else | |
126 | pos += 4; /* IPv4 */ | |
127 | pos += auth_len * 4; | |
128 | if (pos + 4 >= ret) { | |
129 | av_log(s, AV_LOG_WARNING, "Received too short packet\n"); | |
130 | continue; | |
131 | } | |
132 | #define MIME "application/sdp" | |
133 | if (strcmp(&recvbuf[pos], MIME) == 0) { | |
134 | pos += strlen(MIME) + 1; | |
135 | } else if (strncmp(&recvbuf[pos], "v=0\r\n", 5) == 0) { | |
136 | // Direct SDP without a mime type | |
137 | } else { | |
138 | av_log(s, AV_LOG_WARNING, "Unsupported mime type %s\n", | |
139 | &recvbuf[pos]); | |
140 | continue; | |
141 | } | |
142 | ||
143 | sap->sdp = av_strdup(&recvbuf[pos]); | |
144 | break; | |
145 | } | |
146 | ||
147 | av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", sap->sdp); | |
148 | ffio_init_context(&sap->sdp_pb, sap->sdp, strlen(sap->sdp), 0, NULL, NULL, | |
149 | NULL, NULL); | |
150 | ||
151 | infmt = av_find_input_format("sdp"); | |
152 | if (!infmt) | |
153 | goto fail; | |
154 | sap->sdp_ctx = avformat_alloc_context(); | |
155 | if (!sap->sdp_ctx) { | |
156 | ret = AVERROR(ENOMEM); | |
157 | goto fail; | |
158 | } | |
159 | sap->sdp_ctx->max_delay = s->max_delay; | |
160 | sap->sdp_ctx->pb = &sap->sdp_pb; | |
161 | sap->sdp_ctx->interrupt_callback = s->interrupt_callback; | |
f6fa7814 DM |
162 | |
163 | if ((ret = ff_copy_whitelists(sap->sdp_ctx, s)) < 0) | |
164 | goto fail; | |
165 | ||
2ba45a60 DM |
166 | ret = avformat_open_input(&sap->sdp_ctx, "temp.sdp", infmt, NULL); |
167 | if (ret < 0) | |
168 | goto fail; | |
169 | if (sap->sdp_ctx->ctx_flags & AVFMTCTX_NOHEADER) | |
170 | s->ctx_flags |= AVFMTCTX_NOHEADER; | |
171 | for (i = 0; i < sap->sdp_ctx->nb_streams; i++) { | |
172 | AVStream *st = avformat_new_stream(s, NULL); | |
173 | if (!st) { | |
174 | ret = AVERROR(ENOMEM); | |
175 | goto fail; | |
176 | } | |
177 | st->id = i; | |
178 | avcodec_copy_context(st->codec, sap->sdp_ctx->streams[i]->codec); | |
179 | st->time_base = sap->sdp_ctx->streams[i]->time_base; | |
180 | } | |
181 | ||
182 | return 0; | |
183 | ||
184 | fail: | |
185 | sap_read_close(s); | |
186 | return ret; | |
187 | } | |
188 | ||
189 | static int sap_fetch_packet(AVFormatContext *s, AVPacket *pkt) | |
190 | { | |
191 | struct SAPState *sap = s->priv_data; | |
192 | int fd = ffurl_get_file_handle(sap->ann_fd); | |
193 | int n, ret; | |
194 | struct pollfd p = {fd, POLLIN, 0}; | |
195 | uint8_t recvbuf[RTP_MAX_PACKET_LENGTH]; | |
196 | ||
197 | if (sap->eof) | |
198 | return AVERROR_EOF; | |
199 | ||
200 | while (1) { | |
201 | n = poll(&p, 1, 0); | |
202 | if (n <= 0 || !(p.revents & POLLIN)) | |
203 | break; | |
204 | ret = ffurl_read(sap->ann_fd, recvbuf, sizeof(recvbuf)); | |
205 | if (ret >= 8) { | |
206 | uint16_t hash = AV_RB16(&recvbuf[2]); | |
207 | /* Should ideally check the source IP address, too */ | |
208 | if (recvbuf[0] & 0x04 && hash == sap->hash) { | |
209 | /* Stream deletion */ | |
210 | sap->eof = 1; | |
211 | return AVERROR_EOF; | |
212 | } | |
213 | } | |
214 | } | |
215 | ret = av_read_frame(sap->sdp_ctx, pkt); | |
216 | if (ret < 0) | |
217 | return ret; | |
218 | if (s->ctx_flags & AVFMTCTX_NOHEADER) { | |
219 | while (sap->sdp_ctx->nb_streams > s->nb_streams) { | |
220 | int i = s->nb_streams; | |
221 | AVStream *st = avformat_new_stream(s, NULL); | |
222 | if (!st) { | |
223 | av_free_packet(pkt); | |
224 | return AVERROR(ENOMEM); | |
225 | } | |
226 | st->id = i; | |
227 | avcodec_copy_context(st->codec, sap->sdp_ctx->streams[i]->codec); | |
228 | st->time_base = sap->sdp_ctx->streams[i]->time_base; | |
229 | } | |
230 | } | |
231 | return ret; | |
232 | } | |
233 | ||
234 | AVInputFormat ff_sap_demuxer = { | |
235 | .name = "sap", | |
236 | .long_name = NULL_IF_CONFIG_SMALL("SAP input"), | |
237 | .priv_data_size = sizeof(struct SAPState), | |
238 | .read_probe = sap_probe, | |
239 | .read_header = sap_read_header, | |
240 | .read_packet = sap_fetch_packet, | |
241 | .read_close = sap_read_close, | |
242 | .flags = AVFMT_NOFILE, | |
243 | }; |