rtmppkt.c
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1 /*
2  * RTMP input format
3  * Copyright (c) 2009 Kostya Shishkov
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 "libavcodec/bytestream.h"
23 #include "libavutil/avstring.h"
24 #include "libavutil/intfloat.h"
25 #include "avformat.h"
26 
27 #include "rtmppkt.h"
28 #include "flv.h"
29 #include "url.h"
30 
31 void ff_amf_write_bool(uint8_t **dst, int val)
32 {
33  bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
34  bytestream_put_byte(dst, val);
35 }
36 
37 void ff_amf_write_number(uint8_t **dst, double val)
38 {
39  bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
40  bytestream_put_be64(dst, av_double2int(val));
41 }
42 
43 void ff_amf_write_string(uint8_t **dst, const char *str)
44 {
45  bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
46  bytestream_put_be16(dst, strlen(str));
47  bytestream_put_buffer(dst, str, strlen(str));
48 }
49 
50 void ff_amf_write_null(uint8_t **dst)
51 {
52  bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
53 }
54 
55 void ff_amf_write_object_start(uint8_t **dst)
56 {
57  bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
58 }
59 
60 void ff_amf_write_field_name(uint8_t **dst, const char *str)
61 {
62  bytestream_put_be16(dst, strlen(str));
63  bytestream_put_buffer(dst, str, strlen(str));
64 }
65 
66 void ff_amf_write_object_end(uint8_t **dst)
67 {
68  /* first two bytes are field name length = 0,
69  * AMF object should end with it and end marker
70  */
71  bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
72 }
73 
75  int chunk_size, RTMPPacket *prev_pkt)
76 {
77  uint8_t hdr, t, buf[16];
78  int channel_id, timestamp, size, offset = 0;
79  uint32_t extra = 0;
80  enum RTMPPacketType type;
81  int written = 0;
82 
83  if (ffurl_read(h, &hdr, 1) != 1)
84  return AVERROR(EIO);
85  written++;
86  channel_id = hdr & 0x3F;
87 
88  if (channel_id < 2) { //special case for channel number >= 64
89  buf[1] = 0;
90  if (ffurl_read_complete(h, buf, channel_id + 1) != channel_id + 1)
91  return AVERROR(EIO);
92  written += channel_id + 1;
93  channel_id = AV_RL16(buf) + 64;
94  }
95  size = prev_pkt[channel_id].size;
96  type = prev_pkt[channel_id].type;
97  extra = prev_pkt[channel_id].extra;
98 
99  hdr >>= 6;
100  if (hdr == RTMP_PS_ONEBYTE) {
101  timestamp = prev_pkt[channel_id].ts_delta;
102  } else {
103  if (ffurl_read_complete(h, buf, 3) != 3)
104  return AVERROR(EIO);
105  written += 3;
106  timestamp = AV_RB24(buf);
107  if (hdr != RTMP_PS_FOURBYTES) {
108  if (ffurl_read_complete(h, buf, 3) != 3)
109  return AVERROR(EIO);
110  written += 3;
111  size = AV_RB24(buf);
112  if (ffurl_read_complete(h, buf, 1) != 1)
113  return AVERROR(EIO);
114  written++;
115  type = buf[0];
116  if (hdr == RTMP_PS_TWELVEBYTES) {
117  if (ffurl_read_complete(h, buf, 4) != 4)
118  return AVERROR(EIO);
119  written += 4;
120  extra = AV_RL32(buf);
121  }
122  }
123  if (timestamp == 0xFFFFFF) {
124  if (ffurl_read_complete(h, buf, 4) != 4)
125  return AVERROR(EIO);
126  timestamp = AV_RB32(buf);
127  }
128  }
129  if (hdr != RTMP_PS_TWELVEBYTES)
130  timestamp += prev_pkt[channel_id].timestamp;
131 
132  if (ff_rtmp_packet_create(p, channel_id, type, timestamp, size))
133  return -1;
134  p->extra = extra;
135  // save history
136  prev_pkt[channel_id].channel_id = channel_id;
137  prev_pkt[channel_id].type = type;
138  prev_pkt[channel_id].size = size;
139  prev_pkt[channel_id].ts_delta = timestamp - prev_pkt[channel_id].timestamp;
140  prev_pkt[channel_id].timestamp = timestamp;
141  prev_pkt[channel_id].extra = extra;
142  while (size > 0) {
143  int toread = FFMIN(size, chunk_size);
144  if (ffurl_read_complete(h, p->data + offset, toread) != toread) {
146  return AVERROR(EIO);
147  }
148  size -= chunk_size;
149  offset += chunk_size;
150  written += chunk_size;
151  if (size > 0) {
152  ffurl_read_complete(h, &t, 1); //marker
153  written++;
154  if (t != (0xC0 + channel_id))
155  return -1;
156  }
157  }
158  return written;
159 }
160 
162  int chunk_size, RTMPPacket *prev_pkt)
163 {
164  uint8_t pkt_hdr[16], *p = pkt_hdr;
165  int mode = RTMP_PS_TWELVEBYTES;
166  int off = 0;
167  int written = 0;
168 
169  pkt->ts_delta = pkt->timestamp - prev_pkt[pkt->channel_id].timestamp;
170 
171  //if channel_id = 0, this is first presentation of prev_pkt, send full hdr.
172  if (prev_pkt[pkt->channel_id].channel_id &&
173  pkt->extra == prev_pkt[pkt->channel_id].extra) {
174  if (pkt->type == prev_pkt[pkt->channel_id].type &&
175  pkt->size == prev_pkt[pkt->channel_id].size) {
176  mode = RTMP_PS_FOURBYTES;
177  if (pkt->ts_delta == prev_pkt[pkt->channel_id].ts_delta)
178  mode = RTMP_PS_ONEBYTE;
179  } else {
180  mode = RTMP_PS_EIGHTBYTES;
181  }
182  }
183 
184  if (pkt->channel_id < 64) {
185  bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
186  } else if (pkt->channel_id < 64 + 256) {
187  bytestream_put_byte(&p, 0 | (mode << 6));
188  bytestream_put_byte(&p, pkt->channel_id - 64);
189  } else {
190  bytestream_put_byte(&p, 1 | (mode << 6));
191  bytestream_put_le16(&p, pkt->channel_id - 64);
192  }
193  if (mode != RTMP_PS_ONEBYTE) {
194  uint32_t timestamp = pkt->timestamp;
195  if (mode != RTMP_PS_TWELVEBYTES)
196  timestamp = pkt->ts_delta;
197  bytestream_put_be24(&p, timestamp >= 0xFFFFFF ? 0xFFFFFF : timestamp);
198  if (mode != RTMP_PS_FOURBYTES) {
199  bytestream_put_be24(&p, pkt->size);
200  bytestream_put_byte(&p, pkt->type);
201  if (mode == RTMP_PS_TWELVEBYTES)
202  bytestream_put_le32(&p, pkt->extra);
203  }
204  if (timestamp >= 0xFFFFFF)
205  bytestream_put_be32(&p, timestamp);
206  }
207  // save history
208  prev_pkt[pkt->channel_id].channel_id = pkt->channel_id;
209  prev_pkt[pkt->channel_id].type = pkt->type;
210  prev_pkt[pkt->channel_id].size = pkt->size;
211  prev_pkt[pkt->channel_id].timestamp = pkt->timestamp;
212  if (mode != RTMP_PS_TWELVEBYTES) {
213  prev_pkt[pkt->channel_id].ts_delta = pkt->ts_delta;
214  } else {
215  prev_pkt[pkt->channel_id].ts_delta = pkt->timestamp;
216  }
217  prev_pkt[pkt->channel_id].extra = pkt->extra;
218 
219  ffurl_write(h, pkt_hdr, p-pkt_hdr);
220  written = p - pkt_hdr + pkt->size;
221  while (off < pkt->size) {
222  int towrite = FFMIN(chunk_size, pkt->size - off);
223  ffurl_write(h, pkt->data + off, towrite);
224  off += towrite;
225  if (off < pkt->size) {
226  uint8_t marker = 0xC0 | pkt->channel_id;
227  ffurl_write(h, &marker, 1);
228  written++;
229  }
230  }
231  return written;
232 }
233 
234 int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
235  int timestamp, int size)
236 {
237  if (size) {
238  pkt->data = av_malloc(size);
239  if (!pkt->data)
240  return AVERROR(ENOMEM);
241  }
242  pkt->size = size;
243  pkt->channel_id = channel_id;
244  pkt->type = type;
245  pkt->timestamp = timestamp;
246  pkt->extra = 0;
247  pkt->ts_delta = 0;
248 
249  return 0;
250 }
251 
253 {
254  if (!pkt)
255  return;
256  av_freep(&pkt->data);
257  pkt->size = 0;
258 }
259 
260 int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
261 {
262  const uint8_t *base = data;
263 
264  if (data >= data_end)
265  return -1;
266  switch (*data++) {
267  case AMF_DATA_TYPE_NUMBER: return 9;
268  case AMF_DATA_TYPE_BOOL: return 2;
269  case AMF_DATA_TYPE_STRING: return 3 + AV_RB16(data);
270  case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
271  case AMF_DATA_TYPE_NULL: return 1;
272  case AMF_DATA_TYPE_ARRAY:
273  data += 4;
275  for (;;) {
276  int size = bytestream_get_be16(&data);
277  int t;
278  if (!size) {
279  data++;
280  break;
281  }
282  if (data + size >= data_end || data + size < data)
283  return -1;
284  data += size;
285  t = ff_amf_tag_size(data, data_end);
286  if (t < 0 || data + t >= data_end)
287  return -1;
288  data += t;
289  }
290  return data - base;
291  case AMF_DATA_TYPE_OBJECT_END: return 1;
292  default: return -1;
293  }
294 }
295 
296 int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
297  const uint8_t *name, uint8_t *dst, int dst_size)
298 {
299  int namelen = strlen(name);
300  int len;
301 
302  while (*data != AMF_DATA_TYPE_OBJECT && data < data_end) {
303  len = ff_amf_tag_size(data, data_end);
304  if (len < 0)
305  len = data_end - data;
306  data += len;
307  }
308  if (data_end - data < 3)
309  return -1;
310  data++;
311  for (;;) {
312  int size = bytestream_get_be16(&data);
313  if (!size)
314  break;
315  if (data + size >= data_end || data + size < data)
316  return -1;
317  data += size;
318  if (size == namelen && !memcmp(data-size, name, namelen)) {
319  switch (*data++) {
321  snprintf(dst, dst_size, "%g", av_int2double(AV_RB64(data)));
322  break;
323  case AMF_DATA_TYPE_BOOL:
324  snprintf(dst, dst_size, "%s", *data ? "true" : "false");
325  break;
327  len = bytestream_get_be16(&data);
328  av_strlcpy(dst, data, FFMIN(len+1, dst_size));
329  break;
330  default:
331  return -1;
332  }
333  return 0;
334  }
335  len = ff_amf_tag_size(data, data_end);
336  if (len < 0 || data + len >= data_end || data + len < data)
337  return -1;
338  data += len;
339  }
340  return -1;
341 }
342 
343 static const char* rtmp_packet_type(int type)
344 {
345  switch (type) {
346  case RTMP_PT_CHUNK_SIZE: return "chunk size";
347  case RTMP_PT_BYTES_READ: return "bytes read";
348  case RTMP_PT_PING: return "ping";
349  case RTMP_PT_SERVER_BW: return "server bandwidth";
350  case RTMP_PT_CLIENT_BW: return "client bandwidth";
351  case RTMP_PT_AUDIO: return "audio packet";
352  case RTMP_PT_VIDEO: return "video packet";
353  case RTMP_PT_FLEX_STREAM: return "Flex shared stream";
354  case RTMP_PT_FLEX_OBJECT: return "Flex shared object";
355  case RTMP_PT_FLEX_MESSAGE: return "Flex shared message";
356  case RTMP_PT_NOTIFY: return "notification";
357  case RTMP_PT_SHARED_OBJ: return "shared object";
358  case RTMP_PT_INVOKE: return "invoke";
359  case RTMP_PT_METADATA: return "metadata";
360  default: return "unknown";
361  }
362 }
363 
364 static void ff_amf_tag_contents(void *ctx, const uint8_t *data, const uint8_t *data_end)
365 {
366  int size;
367  char buf[1024];
368 
369  if (data >= data_end)
370  return;
371  switch (*data++) {
373  av_log(ctx, AV_LOG_DEBUG, " number %g\n", av_int2double(AV_RB64(data)));
374  return;
375  case AMF_DATA_TYPE_BOOL:
376  av_log(ctx, AV_LOG_DEBUG, " bool %d\n", *data);
377  return;
380  if (data[-1] == AMF_DATA_TYPE_STRING) {
381  size = bytestream_get_be16(&data);
382  } else {
383  size = bytestream_get_be32(&data);
384  }
385  size = FFMIN(size, 1023);
386  memcpy(buf, data, size);
387  buf[size] = 0;
388  av_log(ctx, AV_LOG_DEBUG, " string '%s'\n", buf);
389  return;
390  case AMF_DATA_TYPE_NULL:
391  av_log(ctx, AV_LOG_DEBUG, " NULL\n");
392  return;
393  case AMF_DATA_TYPE_ARRAY:
394  data += 4;
396  av_log(ctx, AV_LOG_DEBUG, " {\n");
397  for (;;) {
398  int size = bytestream_get_be16(&data);
399  int t;
400  memcpy(buf, data, size);
401  buf[size] = 0;
402  if (!size) {
403  av_log(ctx, AV_LOG_DEBUG, " }\n");
404  data++;
405  break;
406  }
407  if (data + size >= data_end || data + size < data)
408  return;
409  data += size;
410  av_log(ctx, AV_LOG_DEBUG, " %s: ", buf);
411  ff_amf_tag_contents(ctx, data, data_end);
412  t = ff_amf_tag_size(data, data_end);
413  if (t < 0 || data + t >= data_end)
414  return;
415  data += t;
416  }
417  return;
419  av_log(ctx, AV_LOG_DEBUG, " }\n");
420  return;
421  default:
422  return;
423  }
424 }
425 
426 void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p)
427 {
428  av_log(ctx, AV_LOG_DEBUG, "RTMP packet type '%s'(%d) for channel %d, timestamp %d, extra field %d size %d\n",
429  rtmp_packet_type(p->type), p->type, p->channel_id, p->timestamp, p->extra, p->size);
430  if (p->type == RTMP_PT_INVOKE || p->type == RTMP_PT_NOTIFY) {
431  uint8_t *src = p->data, *src_end = p->data + p->size;
432  while (src < src_end) {
433  int sz;
434  ff_amf_tag_contents(ctx, src, src_end);
435  sz = ff_amf_tag_size(src, src_end);
436  if (sz < 0)
437  break;
438  src += sz;
439  }
440  } else if (p->type == RTMP_PT_SERVER_BW){
441  av_log(ctx, AV_LOG_DEBUG, "Server BW = %d\n", AV_RB32(p->data));
442  } else if (p->type == RTMP_PT_CLIENT_BW){
443  av_log(ctx, AV_LOG_DEBUG, "Client BW = %d\n", AV_RB32(p->data));
444  } else if (p->type != RTMP_PT_AUDIO && p->type != RTMP_PT_VIDEO && p->type != RTMP_PT_METADATA) {
445  int i;
446  for (i = 0; i < p->size; i++)
447  av_log(ctx, AV_LOG_DEBUG, " %02X", p->data[i]);
448  av_log(ctx, AV_LOG_DEBUG, "\n");
449  }
450 }
451 
452 int ff_amf_match_string(const uint8_t *data, int size, const char *str)
453 {
454  int len = strlen(str);
455  int amf_len, type;
456 
457  if (size < 1)
458  return 0;
459 
460  type = *data++;
461 
462  if (type != AMF_DATA_TYPE_LONG_STRING &&
463  type != AMF_DATA_TYPE_STRING)
464  return 0;
465 
466  if (type == AMF_DATA_TYPE_LONG_STRING) {
467  if ((size -= 4 + 1) < 0)
468  return 0;
469  amf_len = bytestream_get_be32(&data);
470  } else {
471  if ((size -= 2 + 1) < 0)
472  return 0;
473  amf_len = bytestream_get_be16(&data);
474  }
475 
476  if (amf_len > size)
477  return 0;
478 
479  if (amf_len != len)
480  return 0;
481 
482  return !memcmp(data, str, len);
483 }