Fix memleak caused by the fact that url_open_buf() allocates a context
[libav.git] / libavformat / rdt.c
1 /*
2 * Realmedia RTSP protocol (RDT) support.
3 * Copyright (c) 2007 Ronald S. Bultje
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 rdt.c
24 * @brief Realmedia RTSP protocol (RDT) support
25 * @author Ronald S. Bultje <rbultje@ronald.bitfreak.net>
26 */
27
28 #include "avformat.h"
29 #include "libavutil/avstring.h"
30 #include "rtp_internal.h"
31 #include "rdt.h"
32 #include "libavutil/base64.h"
33 #include "libavutil/md5.h"
34 #include "rm.h"
35 #include "internal.h"
36
37 struct RDTDemuxContext {
38 AVFormatContext *ic;
39 AVStream *st;
40 void *dynamic_protocol_context;
41 DynamicPayloadPacketHandlerProc parse_packet;
42 uint32_t prev_set_id, prev_timestamp;
43 };
44
45 RDTDemuxContext *
46 ff_rdt_parse_open(AVFormatContext *ic, AVStream *st,
47 void *priv_data, RTPDynamicProtocolHandler *handler)
48 {
49 RDTDemuxContext *s = av_mallocz(sizeof(RDTDemuxContext));
50 if (!s)
51 return NULL;
52
53 s->ic = ic;
54 s->st = st;
55 s->prev_set_id = -1;
56 s->prev_timestamp = -1;
57 s->parse_packet = handler->parse_packet;
58 s->dynamic_protocol_context = priv_data;
59
60 return s;
61 }
62
63 void
64 ff_rdt_parse_close(RDTDemuxContext *s)
65 {
66 av_free(s);
67 }
68
69 struct PayloadContext {
70 AVFormatContext *rmctx;
71 uint8_t *mlti_data;
72 unsigned int mlti_data_size;
73 char buffer[RTP_MAX_PACKET_LENGTH + FF_INPUT_BUFFER_PADDING_SIZE];
74 };
75
76 void
77 ff_rdt_calc_response_and_checksum(char response[41], char chksum[9],
78 const char *challenge)
79 {
80 int ch_len = strlen (challenge), i;
81 unsigned char zres[16],
82 buf[64] = { 0xa1, 0xe9, 0x14, 0x9d, 0x0e, 0x6b, 0x3b, 0x59 };
83 #define XOR_TABLE_SIZE 37
84 const unsigned char xor_table[XOR_TABLE_SIZE] = {
85 0x05, 0x18, 0x74, 0xd0, 0x0d, 0x09, 0x02, 0x53,
86 0xc0, 0x01, 0x05, 0x05, 0x67, 0x03, 0x19, 0x70,
87 0x08, 0x27, 0x66, 0x10, 0x10, 0x72, 0x08, 0x09,
88 0x63, 0x11, 0x03, 0x71, 0x08, 0x08, 0x70, 0x02,
89 0x10, 0x57, 0x05, 0x18, 0x54 };
90
91 /* some (length) checks */
92 if (ch_len == 40) /* what a hack... */
93 ch_len = 32;
94 else if (ch_len > 56)
95 ch_len = 56;
96 memcpy(buf + 8, challenge, ch_len);
97
98 /* xor challenge bytewise with xor_table */
99 for (i = 0; i < XOR_TABLE_SIZE; i++)
100 buf[8 + i] ^= xor_table[i];
101
102 av_md5_sum(zres, buf, 64);
103 ff_data_to_hex(response, zres, 16);
104 for (i=0;i<32;i++) response[i] = tolower(response[i]);
105
106 /* add tail */
107 strcpy (response + 32, "01d0a8e3");
108
109 /* calculate checksum */
110 for (i = 0; i < 8; i++)
111 chksum[i] = response[i * 4];
112 chksum[8] = 0;
113 }
114
115 static int
116 rdt_load_mdpr (PayloadContext *rdt, AVStream *st, int rule_nr)
117 {
118 ByteIOContext pb;
119 int size;
120 uint32_t tag;
121
122 /**
123 * Layout of the MLTI chunk:
124 * 4:MLTI
125 * 2:<number of streams>
126 * Then for each stream ([number_of_streams] times):
127 * 2:<mdpr index>
128 * 2:<number of mdpr chunks>
129 * Then for each mdpr chunk ([number_of_mdpr_chunks] times):
130 * 4:<size>
131 * [size]:<data>
132 * we skip MDPR chunks until we reach the one of the stream
133 * we're interested in, and forward that ([size]+[data]) to
134 * the RM demuxer to parse the stream-specific header data.
135 */
136 if (!rdt->mlti_data)
137 return -1;
138 init_put_byte(&pb, rdt->mlti_data, rdt->mlti_data_size, 0,
139 NULL, NULL, NULL, NULL);
140 tag = get_le32(&pb);
141 if (tag == MKTAG('M', 'L', 'T', 'I')) {
142 int num, chunk_nr;
143
144 /* read index of MDPR chunk numbers */
145 num = get_be16(&pb);
146 if (rule_nr < 0 || rule_nr >= num)
147 return -1;
148 url_fskip(&pb, rule_nr * 2);
149 chunk_nr = get_be16(&pb);
150 url_fskip(&pb, (num - 1 - rule_nr) * 2);
151
152 /* read MDPR chunks */
153 num = get_be16(&pb);
154 if (chunk_nr >= num)
155 return -1;
156 while (chunk_nr--)
157 url_fskip(&pb, get_be32(&pb));
158 size = get_be32(&pb);
159 } else {
160 size = rdt->mlti_data_size;
161 url_fseek(&pb, 0, SEEK_SET);
162 }
163 if (ff_rm_read_mdpr_codecdata(rdt->rmctx, &pb, st, size) < 0)
164 return -1;
165
166 return 0;
167 }
168
169 /**
170 * Actual data handling.
171 */
172
173 int
174 ff_rdt_parse_header(const uint8_t *buf, int len,
175 int *set_id, int *seq_no, int *stream_id,
176 int *is_keyframe, uint32_t *timestamp)
177 {
178 int consumed = 10;
179
180 /* skip status packets */
181 while (len >= 5 && buf[1] == 0xFF /* status packet */) {
182 int pkt_len;
183
184 if (!(buf[0] & 0x80))
185 return -1; /* not followed by a data packet */
186
187 pkt_len = AV_RB16(buf+3);
188 buf += pkt_len;
189 len -= pkt_len;
190 consumed += pkt_len;
191 }
192 if (len < 10)
193 return -1;
194 /**
195 * Layout of the header (in bits):
196 * 1: len_included
197 * Flag indicating whether this header includes a length field;
198 * this can be used to concatenate multiple RDT packets in a
199 * single UDP/TCP data frame and is used to precede RDT data
200 * by stream status packets
201 * 1: need_reliable
202 * Flag indicating whether this header includes a "reliable
203 * sequence number"; these are apparently sequence numbers of
204 * data packets alone. For data packets, this flag is always
205 * set, according to the Real documentation [1]
206 * 5: set_id
207 * ID of a set of streams of identical content, possibly with
208 * different codecs or bitrates
209 * 1: is_reliable
210 * Flag set for certain streams deemed less tolerable for packet
211 * loss
212 * 16: seq_no
213 * Packet sequence number; if >=0xFF00, this is a non-data packet
214 * containing stream status info, the second byte indicates the
215 * type of status packet (see wireshark docs / source code [2])
216 * if (len_included) {
217 * 16: packet_len
218 * } else {
219 * packet_len = remainder of UDP/TCP frame
220 * }
221 * 1: is_back_to_back
222 * Back-to-Back flag; used for timing, set for one in every 10
223 * packets, according to the Real documentation [1]
224 * 1: is_slow_data
225 * Slow-data flag; currently unused, according to Real docs [1]
226 * 5: stream_id
227 * ID of the stream within this particular set of streams
228 * 1: is_no_keyframe
229 * Non-keyframe flag (unset if packet belongs to a keyframe)
230 * 32: timestamp (PTS)
231 * if (set_id == 0x1F) {
232 * 16: set_id (extended set-of-streams ID; see set_id)
233 * }
234 * if (need_reliable) {
235 * 16: reliable_seq_no
236 * Reliable sequence number (see need_reliable)
237 * }
238 * if (stream_id == 0x3F) {
239 * 16: stream_id (extended stream ID; see stream_id)
240 * }
241 * [1] https://protocol.helixcommunity.org/files/2005/devdocs/RDT_Feature_Level_20.txt
242 * [2] http://www.wireshark.org/docs/dfref/r/rdt.html and
243 * http://anonsvn.wireshark.org/viewvc/trunk/epan/dissectors/packet-rdt.c
244 */
245 if (set_id) *set_id = (buf[0]>>1) & 0x1f;
246 if (seq_no) *seq_no = AV_RB16(buf+1);
247 if (timestamp) *timestamp = AV_RB32(buf+4);
248 if (stream_id) *stream_id = (buf[3]>>1) & 0x1f;
249 if (is_keyframe) *is_keyframe = !(buf[3] & 0x1);
250
251 return consumed;
252 }
253
254 /**< return 0 on packet, no more left, 1 on packet, 1 on partial packet... */
255 static int
256 rdt_parse_packet (PayloadContext *rdt, AVStream *st,
257 AVPacket *pkt, uint32_t *timestamp,
258 const uint8_t *buf, int len, int flags)
259 {
260 int seq = 1, res;
261 ByteIOContext pb;
262 RMContext *rm = rdt->rmctx->priv_data;
263
264 if (rm->audio_pkt_cnt == 0) {
265 int pos;
266
267 init_put_byte(&pb, buf, len, 0, NULL, NULL, NULL, NULL);
268 flags = (flags & PKT_FLAG_KEY) ? 2 : 0;
269 res = ff_rm_parse_packet (rdt->rmctx, &pb, st, len, pkt,
270 &seq, &flags, timestamp);
271 pos = url_ftell(&pb);
272 if (res < 0)
273 return res;
274 if (rm->audio_pkt_cnt > 0 &&
275 st->codec->codec_id == CODEC_ID_AAC) {
276 memcpy (rdt->buffer, buf + pos, len - pos);
277 rdt->rmctx->pb = av_alloc_put_byte (rdt->buffer, len - pos, 0,
278 NULL, NULL, NULL, NULL);
279 }
280 } else {
281 ff_rm_retrieve_cache (rdt->rmctx, rdt->rmctx->pb, st, pkt);
282 if (rm->audio_pkt_cnt == 0 &&
283 st->codec->codec_id == CODEC_ID_AAC)
284 av_freep(&rdt->rmctx->pb);
285 }
286 pkt->stream_index = st->index;
287 pkt->pts = *timestamp;
288
289 return rm->audio_pkt_cnt > 0;
290 }
291
292 int
293 ff_rdt_parse_packet(RDTDemuxContext *s, AVPacket *pkt,
294 const uint8_t *buf, int len)
295 {
296 int seq_no, flags = 0, stream_id, set_id, is_keyframe;
297 uint32_t timestamp;
298 int rv= 0;
299
300 if (!s->parse_packet)
301 return -1;
302
303 if (!buf) {
304 /* return the next packets, if any */
305 timestamp= 0; ///< Should not be used if buf is NULL, but should be set to the timestamp of the packet returned....
306 rv= s->parse_packet(s->dynamic_protocol_context,
307 s->st, pkt, &timestamp, NULL, 0, flags);
308 return rv;
309 }
310
311 if (len < 12)
312 return -1;
313 rv = ff_rdt_parse_header(buf, len, &set_id, &seq_no, &stream_id, &is_keyframe, &timestamp);
314 if (rv < 0)
315 return rv;
316 if (is_keyframe && (set_id != s->prev_set_id || timestamp != s->prev_timestamp)) {
317 flags |= PKT_FLAG_KEY;
318 s->prev_set_id = set_id;
319 s->prev_timestamp = timestamp;
320 }
321 buf += rv;
322 len -= rv;
323
324 rv = s->parse_packet(s->dynamic_protocol_context,
325 s->st, pkt, &timestamp, buf, len, flags);
326
327 return rv;
328 }
329
330 void
331 ff_rdt_subscribe_rule (char *cmd, int size,
332 int stream_nr, int rule_nr)
333 {
334 av_strlcatf(cmd, size, "stream=%d;rule=%d,stream=%d;rule=%d",
335 stream_nr, rule_nr * 2, stream_nr, rule_nr * 2 + 1);
336 }
337
338 void
339 ff_rdt_subscribe_rule2 (RDTDemuxContext *s, char *cmd, int size,
340 int stream_nr, int rule_nr)
341 {
342 PayloadContext *rdt = s->dynamic_protocol_context;
343
344 rdt_load_mdpr(rdt, s->st, rule_nr * 2);
345 }
346
347 static unsigned char *
348 rdt_parse_b64buf (unsigned int *target_len, const char *p)
349 {
350 unsigned char *target;
351 int len = strlen(p);
352 if (*p == '\"') {
353 p++;
354 len -= 2; /* skip embracing " at start/end */
355 }
356 *target_len = len * 3 / 4;
357 target = av_mallocz(*target_len + FF_INPUT_BUFFER_PADDING_SIZE);
358 av_base64_decode(target, p, *target_len);
359 return target;
360 }
361
362 static int
363 rdt_parse_sdp_line (AVStream *stream, PayloadContext *rdt, const char *line)
364 {
365 const char *p = line;
366
367 if (av_strstart(p, "OpaqueData:buffer;", &p)) {
368 rdt->mlti_data = rdt_parse_b64buf(&rdt->mlti_data_size, p);
369 } else if (av_strstart(p, "StartTime:integer;", &p))
370 stream->first_dts = atoi(p);
371
372 return 0;
373 }
374
375 static PayloadContext *
376 rdt_new_extradata (void)
377 {
378 PayloadContext *rdt = av_mallocz(sizeof(PayloadContext));
379
380 av_open_input_stream(&rdt->rmctx, NULL, "", &rdt_demuxer, NULL);
381
382 return rdt;
383 }
384
385 static void
386 rdt_free_extradata (PayloadContext *rdt)
387 {
388 if (rdt->rmctx)
389 av_close_input_stream(rdt->rmctx);
390 av_freep(&rdt->mlti_data);
391 av_free(rdt);
392 }
393
394 #define RDT_HANDLER(n, s, t) \
395 static RTPDynamicProtocolHandler ff_rdt_ ## n ## _handler = { \
396 s, \
397 t, \
398 CODEC_ID_NONE, \
399 rdt_parse_sdp_line, \
400 rdt_new_extradata, \
401 rdt_free_extradata, \
402 rdt_parse_packet \
403 };
404
405 RDT_HANDLER(live_video, "x-pn-multirate-realvideo-live", CODEC_TYPE_VIDEO);
406 RDT_HANDLER(live_audio, "x-pn-multirate-realaudio-live", CODEC_TYPE_AUDIO);
407 RDT_HANDLER(video, "x-pn-realvideo", CODEC_TYPE_VIDEO);
408 RDT_HANDLER(audio, "x-pn-realaudio", CODEC_TYPE_AUDIO);
409
410 void av_register_rdt_dynamic_payload_handlers(void)
411 {
412 ff_register_dynamic_payload_handler(&ff_rdt_video_handler);
413 ff_register_dynamic_payload_handler(&ff_rdt_audio_handler);
414 ff_register_dynamic_payload_handler(&ff_rdt_live_video_handler);
415 ff_register_dynamic_payload_handler(&ff_rdt_live_audio_handler);
416 }