1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
|
/** rtp.c
*
* Copyright (C) 2013 Tox project All Rights Reserved.
*
* This file is part of Tox.
*
* Tox is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Tox is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Tox. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif /* HAVE_CONFIG_H */
#include "../toxcore/logger.h"
#include "../toxcore/util.h"
#include "rtp.h"
#include <stdlib.h>
void toxav_handle_packet(RTPSession *_session, RTPMessage *_msg);
#define size_32 4
#define ADD_FLAG_VERSION(_h, _v) do { ( _h->flags ) &= 0x3F; ( _h->flags ) |= ( ( ( _v ) << 6 ) & 0xC0 ); } while(0)
#define ADD_FLAG_PADDING(_h, _v) do { if ( _v > 0 ) _v = 1; ( _h->flags ) &= 0xDF; ( _h->flags ) |= ( ( ( _v ) << 5 ) & 0x20 ); } while(0)
#define ADD_FLAG_EXTENSION(_h, _v) do { if ( _v > 0 ) _v = 1; ( _h->flags ) &= 0xEF;( _h->flags ) |= ( ( ( _v ) << 4 ) & 0x10 ); } while(0)
#define ADD_FLAG_CSRCC(_h, _v) do { ( _h->flags ) &= 0xF0; ( _h->flags ) |= ( ( _v ) & 0x0F ); } while(0)
#define ADD_SETTING_MARKER(_h, _v) do { if ( _v > 1 ) _v = 1; ( _h->marker_payloadt ) &= 0x7F; ( _h->marker_payloadt ) |= ( ( ( _v ) << 7 ) /*& 0x80 */ ); } while(0)
#define ADD_SETTING_PAYLOAD(_h, _v) do { if ( _v > 127 ) _v = 127; ( _h->marker_payloadt ) &= 0x80; ( _h->marker_payloadt ) |= ( ( _v ) /* & 0x7F */ ); } while(0)
#define GET_FLAG_VERSION(_h) (( _h->flags & 0xd0 ) >> 6)
#define GET_FLAG_PADDING(_h) (( _h->flags & 0x20 ) >> 5)
#define GET_FLAG_EXTENSION(_h) (( _h->flags & 0x10 ) >> 4)
#define GET_FLAG_CSRCC(_h) ( _h->flags & 0x0f )
#define GET_SETTING_MARKER(_h) (( _h->marker_payloadt ) >> 7)
#define GET_SETTING_PAYLOAD(_h) ((_h->marker_payloadt) & 0x7f)
/**
* @brief Checks if message came in late.
*
* @param session Control session.
* @param msg The message.
* @return int
* @retval -1 The message came in order.
* @retval 0 The message came late.
*/
inline__ int check_late_message (RTPSession *session, RTPMessage *msg)
{
/*
* Check Sequence number. If this new msg has lesser number then the session->rsequnum
* it shows that the message came in late. Also check timestamp to be 100% certain.
*
*/
return ( msg->header->sequnum < session->rsequnum && msg->header->timestamp < session->timestamp ) ? 0 : -1;
}
/**
* @brief Extracts header from payload.
*
* @param payload The payload.
* @param length The size of payload.
* @return RTPHeader* Extracted header.
* @retval NULL Error occurred while extracting header.
*/
RTPHeader *extract_header ( const uint8_t *payload, int length )
{
if ( !payload || !length ) {
LOGGER_WARNING("No payload to extract!");
return NULL;
}
RTPHeader *_retu = calloc(1, sizeof (RTPHeader));
if ( !_retu ) {
LOGGER_WARNING("Alloc failed! Program might misbehave!");
return NULL;
}
bytes_to_U16(&_retu->sequnum, payload);
const uint8_t *_it = payload + 2;
_retu->flags = *_it;
++_it;
/* This indicates if the first 2 bits are valid.
* Now it may happen that this is out of order but
* it cuts down chances of parsing some invalid value
*/
if ( GET_FLAG_VERSION(_retu) != RTP_VERSION ) {
/* Deallocate */
LOGGER_WARNING("Invalid version!");
free(_retu);
return NULL;
}
/*
* Added a check for the size of the header little sooner so
* I don't need to parse the other stuff if it's bad
*/
uint8_t _cc = GET_FLAG_CSRCC ( _retu );
uint32_t _length = 12 /* Minimum header len */ + ( _cc * 4 );
if ( length < _length ) {
/* Deallocate */
LOGGER_WARNING("Length invalid!");
free(_retu);
return NULL;
}
memset(_retu->csrc, 0, 16 * sizeof (uint32_t));
_retu->marker_payloadt = *_it;
++_it;
_retu->length = _length;
bytes_to_U32(&_retu->timestamp, _it);
_it += 4;
bytes_to_U32(&_retu->ssrc, _it);
uint8_t _x;
for ( _x = 0; _x < _cc; _x++ ) {
_it += 4;
bytes_to_U32(&(_retu->csrc[_x]), _it);
}
return _retu;
}
/**
* @brief Extracts external header from payload. Must be called AFTER extract_header()!
*
* @param payload The ITERATED payload.
* @param length The size of payload.
* @return RTPExtHeader* Extracted extension header.
* @retval NULL Error occurred while extracting extension header.
*/
RTPExtHeader *extract_ext_header ( const uint8_t *payload, uint16_t length )
{
const uint8_t *_it = payload;
RTPExtHeader *_retu = calloc(1, sizeof (RTPExtHeader));
if ( !_retu ) {
LOGGER_WARNING("Alloc failed! Program might misbehave!");
return NULL;
}
uint16_t _ext_length;
bytes_to_U16(&_ext_length, _it);
_it += 2;
if ( length < ( _ext_length * sizeof(uint32_t) ) ) {
LOGGER_WARNING("Length invalid!");
free(_retu);
return NULL;
}
_retu->length = _ext_length;
bytes_to_U16(&_retu->type, _it);
_it += 2;
if ( !(_retu->table = calloc(_ext_length, sizeof (uint32_t))) ) {
LOGGER_WARNING("Alloc failed! Program might misbehave!");
free(_retu);
return NULL;
}
uint16_t _x;
for ( _x = 0; _x < _ext_length; _x++ ) {
_it += 4;
bytes_to_U32(&(_retu->table[_x]), _it);
}
return _retu;
}
/**
* @brief Adds header to payload. Make sure _payload_ has enough space.
*
* @param header The header.
* @param payload The payload.
* @return uint8_t* Iterated position.
*/
uint8_t *add_header ( RTPHeader *header, uint8_t *payload )
{
uint8_t _cc = GET_FLAG_CSRCC ( header );
uint8_t *_it = payload;
/* Add sequence number first */
U16_to_bytes(_it, header->sequnum);
_it += 2;
*_it = header->flags;
++_it;
*_it = header->marker_payloadt;
++_it;
U32_to_bytes( _it, header->timestamp);
_it += 4;
U32_to_bytes( _it, header->ssrc);
uint8_t _x;
for ( _x = 0; _x < _cc; _x++ ) {
_it += 4;
U32_to_bytes( _it, header->csrc[_x]);
}
return _it + 4;
}
/**
* @brief Adds extension header to payload. Make sure _payload_ has enough space.
*
* @param header The header.
* @param payload The payload.
* @return uint8_t* Iterated position.
*/
uint8_t *add_ext_header ( RTPExtHeader *header, uint8_t *payload )
{
uint8_t *_it = payload;
U16_to_bytes(_it, header->length);
_it += 2;
U16_to_bytes(_it, header->type);
_it -= 2; /* Return to 0 position */
if ( header->table ) {
uint16_t _x;
for ( _x = 0; _x < header->length; _x++ ) {
_it += 4;
U32_to_bytes(_it, header->table[_x]);
}
}
return _it + 4;
}
/**
* @brief Builds header from control session values.
*
* @param session Control session.
* @return RTPHeader* Created header.
*/
RTPHeader *build_header ( RTPSession *session )
{
RTPHeader *_retu = calloc ( 1, sizeof (RTPHeader) );
if ( !_retu ) {
LOGGER_WARNING("Alloc failed! Program might misbehave!");
return NULL;
}
ADD_FLAG_VERSION ( _retu, session->version );
ADD_FLAG_PADDING ( _retu, session->padding );
ADD_FLAG_EXTENSION ( _retu, session->extension );
ADD_FLAG_CSRCC ( _retu, session->cc );
ADD_SETTING_MARKER ( _retu, session->marker );
ADD_SETTING_PAYLOAD ( _retu, session->payload_type );
_retu->sequnum = session->sequnum;
_retu->timestamp = current_time_monotonic(); /* milliseconds */
_retu->ssrc = session->ssrc;
int i;
for ( i = 0; i < session->cc; i++ )
_retu->csrc[i] = session->csrc[i];
_retu->length = 12 /* Minimum header len */ + ( session->cc * size_32 );
return _retu;
}
/**
* @brief Parses data into RTPMessage struct. Stores headers separately from the payload data
* and so the length variable is set accordingly. _sequnum_ argument is
* passed by the handle_packet() since it's parsed already.
*
* @param session Control session.
* @param sequnum Sequence number that's parsed from payload in handle_packet()
* @param data Payload data.
* @param length Payload size.
* @return RTPMessage*
* @retval NULL Error occurred.
*/
RTPMessage *msg_parse ( const uint8_t *data, int length )
{
RTPMessage *_retu = calloc(1, sizeof (RTPMessage));
_retu->header = extract_header ( data, length ); /* It allocates memory and all */
if ( !_retu->header ) {
LOGGER_WARNING("Header failed to extract!");
free(_retu);
return NULL;
}
uint16_t _from_pos = _retu->header->length;
_retu->length = length - _from_pos;
if ( GET_FLAG_EXTENSION ( _retu->header ) ) {
_retu->ext_header = extract_ext_header ( data + _from_pos, length );
if ( _retu->ext_header ) {
_retu->length -= ( 4 /* Minimum ext header len */ + _retu->ext_header->length * size_32 );
_from_pos += ( 4 /* Minimum ext header len */ + _retu->ext_header->length * size_32 );
} else { /* Error */
LOGGER_WARNING("Ext Header failed to extract!");
rtp_free_msg(NULL, _retu);
return NULL;
}
} else {
_retu->ext_header = NULL;
}
if ( length - _from_pos <= MAX_RTP_SIZE )
memcpy ( _retu->data, data + _from_pos, length - _from_pos );
else {
LOGGER_WARNING("Invalid length!");
rtp_free_msg(NULL, _retu);
return NULL;
}
_retu->next = NULL;
return _retu;
}
/**
* @brief Callback for networking core.
*
* @param object RTPSession object.
* @param ip_port Where the message comes from.
* @param data Message data.
* @param length Message length.
* @return int
* @retval -1 Error occurred.
* @retval 0 Success.
*/
int rtp_handle_packet ( void *object, const uint8_t *data, uint32_t length )
{
RTPSession *_session = object;
RTPMessage *_msg;
if ( !_session || length < 13 ) { /* 12 is the minimum length for rtp + desc. byte */
LOGGER_WARNING("No session or invalid length of received buffer!");
return -1;
}
_msg = msg_parse ( data + 1, length - 1 );
if ( !_msg ) {
LOGGER_WARNING("Could not parse message!");
return -1;
}
/* Check if message came in late */
if ( check_late_message(_session, _msg) < 0 ) { /* Not late */
_session->rsequnum = _msg->header->sequnum;
_session->timestamp = _msg->header->timestamp;
}
toxav_handle_packet(_session, _msg);
return 0;
}
/**
* @brief Stores headers and payload data in one container ( data )
* and the length is set accordingly. Returned message is used for sending _only_.
*
* @param session The control session.
* @param data Payload data to send ( This is what you pass ).
* @param length Size of the payload data.
* @return RTPMessage* Created message.
* @retval NULL Error occurred.
*/
RTPMessage *rtp_new_message ( RTPSession *session, const uint8_t *data, uint32_t length )
{
if ( !session ) {
LOGGER_WARNING("No session!");
return NULL;
}
uint8_t *_from_pos;
RTPMessage *_retu = calloc(1, sizeof (RTPMessage));
if ( !_retu ) {
LOGGER_WARNING("Alloc failed! Program might misbehave!");
return NULL;
}
/* Sets header values and copies the extension header in _retu */
_retu->header = build_header ( session ); /* It allocates memory and all */
_retu->ext_header = session->ext_header;
uint32_t _total_length = length + _retu->header->length + 1;
_retu->data[0] = session->prefix;
if ( _retu->ext_header ) {
_total_length += ( 4 /* Minimum ext header len */ + _retu->ext_header->length * size_32 );
_from_pos = add_header ( _retu->header, _retu->data + 1 );
_from_pos = add_ext_header ( _retu->ext_header, _from_pos + 1 );
} else {
_from_pos = add_header ( _retu->header, _retu->data + 1 );
}
/*
* Parses the extension header into the message
* Of course if any
*/
/* Appends _data on to _retu->_data */
memcpy ( _from_pos, data, length );
_retu->length = _total_length;
_retu->next = NULL;
return _retu;
}
/**
* @brief Sends data to _RTPSession::dest
*
* @param session The session.
* @param messenger Tox* object.
* @param data The payload.
* @param length Size of the payload.
* @return int
* @retval -1 On error.
* @retval 0 On success.
*/
int rtp_send_msg ( RTPSession *session, Messenger *messenger, const uint8_t *data, uint16_t length )
{
RTPMessage *msg = rtp_new_message (session, data, length);
if ( !msg ) {
LOGGER_WARNING("No session!");
return -1;
}
if ( -1 == send_custom_lossy_packet(messenger, session->dest, msg->data, msg->length) ) {
LOGGER_WARNING("Failed to send full packet! std error: %s", strerror(errno));
rtp_free_msg ( session, msg );
return -1;
}
/* Set sequ number */
session->sequnum = session->sequnum >= MAX_SEQU_NUM ? 0 : session->sequnum + 1;
rtp_free_msg ( session, msg );
return 0;
}
/**
* @brief Speaks for it self.
*
* @param session The control session msg belongs to. You set it as NULL when freeing recved messages.
* Otherwise set it to session the message was created from.
* @param msg The message.
* @return void
*/
void rtp_free_msg ( RTPSession *session, RTPMessage *msg )
{
if ( !session ) {
if ( msg->ext_header ) {
free ( msg->ext_header->table );
free ( msg->ext_header );
}
} else {
if ( msg->ext_header && session->ext_header != msg->ext_header ) {
free ( msg->ext_header->table );
free ( msg->ext_header );
}
}
free ( msg->header );
free ( msg );
}
/**
* @brief Must be called before calling any other rtp function. It's used
* to initialize RTP control session.
*
* @param payload_type Type of payload used to send. You can use values in toxmsi.h::MSICallType
* @param messenger Tox* object.
* @param friend_num Friend id.
* @return RTPSession* Created control session.
* @retval NULL Error occurred.
*/
RTPSession *rtp_init_session ( int payload_type, Messenger *messenger, int friend_num )
{
RTPSession *_retu = calloc(1, sizeof(RTPSession));
if ( !_retu ) {
LOGGER_WARNING("Alloc failed! Program might misbehave!");
return NULL;
}
if ( -1 == custom_lossy_packet_registerhandler(messenger, friend_num, payload_type, rtp_handle_packet, _retu)) {
LOGGER_ERROR("Error setting custom register handler for rtp session");
free(_retu);
return NULL;
}
LOGGER_DEBUG("Registered packet handler: pt: %d; fid: %d", payload_type, friend_num);
_retu->version = RTP_VERSION; /* It's always 2 */
_retu->padding = 0; /* If some additional data is needed about the packet */
_retu->extension = 0; /* If extension to header is needed */
_retu->cc = 1; /* Amount of contributors */
_retu->csrc = NULL; /* Container */
_retu->ssrc = random_int();
_retu->marker = 0;
_retu->payload_type = payload_type % 128;
_retu->dest = friend_num;
_retu->rsequnum = _retu->sequnum = 0;
_retu->ext_header = NULL; /* When needed allocate */
if ( !(_retu->csrc = calloc(1, sizeof (uint32_t))) ) {
LOGGER_WARNING("Alloc failed! Program might misbehave!");
free(_retu);
return NULL;
}
_retu->csrc[0] = _retu->ssrc; /* Set my ssrc to the list receive */
/* Also set payload type as prefix */
_retu->prefix = payload_type;
/*
*
*/
return _retu;
}
/**
* @brief Terminate the session.
*
* @param session The session.
* @param messenger The messenger who owns the session
* @return int
* @retval -1 Error occurred.
* @retval 0 Success.
*/
void rtp_terminate_session ( RTPSession *session, Messenger *messenger )
{
if ( !session ) return;
custom_lossy_packet_registerhandler(messenger, session->dest, session->prefix, NULL, NULL);
free ( session->ext_header );
free ( session->csrc );
LOGGER_DEBUG("Terminated RTP session: %p", session);
/* And finally free session */
free ( session );
}
|