git.sesse.net Git - vlc/blob - modules/stream_out/rtsp.c

   1 /*****************************************************************************
   2  * rtsp.c: RTSP support for RTP stream output module
   3  *****************************************************************************
   4  * Copyright (C) 2003-2004 the VideoLAN team
   5  * Copyright © 2007 Rémi Denis-Courmont
   6  *
   7  * $Id: rtp.c 21407 2007-08-22 20:10:41Z courmisch $
   8  *
   9  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29 #include <vlc/vlc.h>
  30 #include <vlc_sout.h>
  31
  32 #include <vlc_httpd.h>
  33 #include <vlc_url.h>
  34 #include <vlc_network.h>
  35 #include <vlc_rand.h>
  36 #include <assert.h>
  37 #include <errno.h>
  38 #include <stdlib.h>
  39
  40 #include "rtp.h"
  41
  42 typedef struct rtsp_session_t rtsp_session_t;
  43
  44 struct rtsp_stream_t
  45 {
  46     vlc_mutex_t     lock;
  47     sout_stream_t  *owner;
  48     httpd_host_t   *host;
  49     httpd_url_t    *url;
  50     char           *psz_path;
  51     const char     *track_fmt;
  52     unsigned        port;
  53
  54     int             sessionc;
  55     rtsp_session_t **sessionv;
  56 };
  57
  58
  59 static int  RtspCallback( httpd_callback_sys_t *p_args,
  60                           httpd_client_t *cl, httpd_message_t *answer,
  61                           const httpd_message_t *query );
  62 static int  RtspCallbackId( httpd_callback_sys_t *p_args,
  63                             httpd_client_t *cl, httpd_message_t *answer,
  64                             const httpd_message_t *query );
  65 static void RtspClientDel( rtsp_stream_t *rtsp, rtsp_session_t *session );
  66
  67 rtsp_stream_t *RtspSetup( sout_stream_t *p_stream, const vlc_url_t *url )
  68 {
  69     rtsp_stream_t *rtsp = malloc( sizeof( *rtsp ) );
  70
  71     if( rtsp == NULL || ( url->i_port > 99999 ) )
  72     {
  73         free( rtsp );
  74         return NULL;
  75     }
  76
  77     rtsp->owner = p_stream;
  78     rtsp->sessionc = 0;
  79     rtsp->sessionv = NULL;
  80     rtsp->host = NULL;
  81     rtsp->url = NULL;
  82     rtsp->psz_path = NULL;
  83     vlc_mutex_init( p_stream, &rtsp->lock );
  84
  85     rtsp->port = (url->i_port > 0) ? url->i_port : 554;
  86     rtsp->psz_path = strdup( ( url->psz_path != NULL ) ? url->psz_path : "/" );
  87     if( rtsp->psz_path == NULL )
  88         goto error;
  89
  90     assert( strlen( rtsp->psz_path ) > 0 );
  91     if( rtsp->psz_path[strlen( rtsp->psz_path ) - 1] == '/' )
  92         rtsp->track_fmt = "%strackID=%u";
  93     else
  94         rtsp->track_fmt = "%s/trackID=%u";
  95
  96     msg_Dbg( p_stream, "RTSP stream: host %s port %d at %s",
  97              url->psz_host, rtsp->port, rtsp->psz_path );
  98
  99     rtsp->host = httpd_HostNew( VLC_OBJECT(p_stream), url->psz_host,
 100                                 rtsp->port );
 101     if( rtsp->host == NULL )
 102         goto error;
 103
 104     rtsp->url = httpd_UrlNewUnique( rtsp->host, rtsp->psz_path,
 105                                     NULL, NULL, NULL );
 106     if( rtsp->url == NULL )
 107         goto error;
 108
 109     httpd_UrlCatch( rtsp->url, HTTPD_MSG_DESCRIBE, RtspCallback, (void*)rtsp );
 110     httpd_UrlCatch( rtsp->url, HTTPD_MSG_SETUP,    RtspCallback, (void*)rtsp );
 111     httpd_UrlCatch( rtsp->url, HTTPD_MSG_PLAY,     RtspCallback, (void*)rtsp );
 112     httpd_UrlCatch( rtsp->url, HTTPD_MSG_PAUSE,    RtspCallback, (void*)rtsp );
 113     httpd_UrlCatch( rtsp->url, HTTPD_MSG_GETPARAMETER, RtspCallback,
 114                     (void*)rtsp );
 115     httpd_UrlCatch( rtsp->url, HTTPD_MSG_TEARDOWN, RtspCallback, (void*)rtsp );
 116     return rtsp;
 117
 118 error:
 119     RtspUnsetup( rtsp );
 120     return NULL;
 121 }
 122
 123
 124 void RtspUnsetup( rtsp_stream_t *rtsp )
 125 {
 126     while( rtsp->sessionc > 0 )
 127         RtspClientDel( rtsp, rtsp->sessionv[0] );
 128
 129     if( rtsp->url )
 130         httpd_UrlDelete( rtsp->url );
 131
 132     if( rtsp->host )
 133         httpd_HostDelete( rtsp->host );
 134
 135     free( rtsp->psz_path );
 136     vlc_mutex_destroy( &rtsp->lock );
 137 }
 138
 139
 140 struct rtsp_stream_id_t
 141 {
 142     rtsp_stream_t    *stream;
 143     sout_stream_id_t *sout_id;
 144     httpd_url_t      *url;
 145     const char       *dst;
 146     int               ttl;
 147     unsigned          loport, hiport;
 148 };
 149
 150
 151 typedef struct rtsp_strack_t rtsp_strack_t;
 152
 153 /* For unicast streaming */
 154 struct rtsp_session_t
 155 {
 156     rtsp_stream_t *stream;
 157     uint64_t       id;
 158
 159     /* output (id-access) */
 160     int            trackc;
 161     rtsp_strack_t *trackv;
 162 };
 163
 164
 165 /* Unicast session track */
 166 struct rtsp_strack_t
 167 {
 168     sout_stream_id_t  *id;
 169     int                fd;
 170     vlc_bool_t         playing;
 171 };
 172
 173
 174 rtsp_stream_id_t *RtspAddId( rtsp_stream_t *rtsp, sout_stream_id_t *sid,
 175                              unsigned num,
 176                              /* Multicast stuff - TODO: cleanup */
 177                              const char *dst, int ttl,
 178                              unsigned loport, unsigned hiport )
 179 {
 180     char urlbuf[sizeof( "/trackID=123" ) + strlen( rtsp->psz_path )];
 181     rtsp_stream_id_t *id = malloc( sizeof( *id ) );
 182     httpd_url_t *url;
 183
 184     if( id == NULL )
 185         return NULL;
 186
 187     id->stream = rtsp;
 188     id->sout_id = sid;
 189     /* TODO: can we assume that this need not be strdup'd? */
 190     id->dst = dst;
 191     if( id->dst != NULL )
 192     {
 193         id->ttl = ttl;
 194         id->loport = loport;
 195         id->hiport = hiport;
 196     }
 197
 198     snprintf( urlbuf, sizeof( urlbuf ), rtsp->track_fmt, rtsp->psz_path,
 199               num );
 200     msg_Dbg( rtsp->owner, "RTSP: adding %s", urlbuf );
 201     url = id->url = httpd_UrlNewUnique( rtsp->host, urlbuf, NULL, NULL, NULL );
 202
 203     if( url == NULL )
 204     {
 205         free( id );
 206         return NULL;
 207     }
 208
 209     httpd_UrlCatch( url, HTTPD_MSG_DESCRIBE, RtspCallbackId, (void *)id );
 210     httpd_UrlCatch( url, HTTPD_MSG_SETUP,    RtspCallbackId, (void *)id );
 211     httpd_UrlCatch( url, HTTPD_MSG_PLAY,     RtspCallbackId, (void *)id );
 212     httpd_UrlCatch( url, HTTPD_MSG_PAUSE,    RtspCallbackId, (void *)id );
 213     httpd_UrlCatch( url, HTTPD_MSG_GETPARAMETER, RtspCallbackId, (void *)id );
 214     httpd_UrlCatch( url, HTTPD_MSG_TEARDOWN, RtspCallbackId, (void *)id );
 215
 216     return id;
 217 }
 218
 219
 220 void RtspDelId( rtsp_stream_t *rtsp, rtsp_stream_id_t *id )
 221 {
 222     vlc_mutex_lock( &rtsp->lock );
 223     for( int i = 0; i < rtsp->sessionc; i++ )
 224     {
 225         rtsp_session_t *ses = rtsp->sessionv[i];
 226
 227         for( int j = 0; j < ses->trackc; j++ )
 228         {
 229             if( ses->trackv[j].id == id->sout_id )
 230             {
 231                 rtsp_strack_t *tr = ses->trackv + j;
 232                 net_Close( tr->fd );
 233                 REMOVE_ELEM( ses->trackv, ses->trackc, j );
 234             }
 235         }
 236     }
 237
 238     vlc_mutex_unlock( &rtsp->lock );
 239     httpd_UrlDelete( id->url );
 240     free( id );
 241 }
 242
 243
 244 /** rtsp must be locked */
 245 static
 246 rtsp_session_t *RtspClientNew( rtsp_stream_t *rtsp )
 247 {
 248     rtsp_session_t *s = malloc( sizeof( *s ) );
 249     if( s == NULL )
 250         return NULL;
 251
 252     s->stream = rtsp;
 253     vlc_rand_bytes (&s->id, sizeof (s->id));
 254     s->trackc = 0;
 255     s->trackv = NULL;
 256
 257     TAB_APPEND( rtsp->sessionc, rtsp->sessionv, s );
 258
 259     return s;
 260 }
 261
 262
 263 /** rtsp must be locked */
 264 static
 265 rtsp_session_t *RtspClientGet( rtsp_stream_t *rtsp, const char *name )
 266 {
 267     char *end;
 268     uint64_t id;
 269     int i;
 270
 271     if( name == NULL )
 272         return NULL;
 273
 274     errno = 0;
 275     id = strtoull( name, &end, 0x10 );
 276     if( errno || *end )
 277         return NULL;
 278
 279     /* FIXME: use a hash/dictionary */
 280     for( i = 0; i < rtsp->sessionc; i++ )
 281     {
 282         if( rtsp->sessionv[i]->id == id )
 283             return rtsp->sessionv[i];
 284     }
 285     return NULL;
 286 }
 287
 288
 289 /** rtsp must be locked */
 290 static
 291 void RtspClientDel( rtsp_stream_t *rtsp, rtsp_session_t *session )
 292 {
 293     int i;
 294     TAB_REMOVE( rtsp->sessionc, rtsp->sessionv, session );
 295
 296     for( i = 0; i < session->trackc; i++ )
 297         rtp_del_sink( session->trackv[i].id, session->trackv[i].fd );
 298
 299     free( session->trackv );
 300     free( session );
 301 }
 302
 303
 304 /** Finds the next transport choice */
 305 static inline const char *transport_next( const char *str )
 306 {
 307     /* Looks for comma */
 308     str = strchr( str, ',' );
 309     if( str == NULL )
 310         return NULL; /* No more transport options */
 311
 312     str++; /* skips comma */
 313     while( strchr( "\r\n\t ", *str ) )
 314         str++;
 315
 316     return (*str) ? str : NULL;
 317 }
 318
 319
 320 /** Finds the next transport parameter */
 321 static inline const char *parameter_next( const char *str )
 322 {
 323     while( strchr( ",;", *str ) == NULL )
 324         str++;
 325
 326     return (*str == ';') ? (str + 1) : NULL;
 327 }
 328
 329
 330 /** RTSP requests handler
 331  * @param id selected track for non-aggregate URLs,
 332  *           NULL for aggregate URLs
 333  */
 334 static int RtspHandler( rtsp_stream_t *rtsp, rtsp_stream_id_t *id,
 335                         httpd_client_t *cl,
 336                         httpd_message_t *answer,
 337                         const httpd_message_t *query )
 338 {
 339     sout_stream_t *p_stream = rtsp->owner;
 340     char psz_sesbuf[17];
 341     const char *psz_session = NULL, *psz;
 342     char control[sizeof("rtsp://[]:12345") + NI_MAXNUMERICHOST
 343                   + strlen( rtsp->psz_path )];
 344
 345     if( answer == NULL || query == NULL || cl == NULL )
 346         return VLC_SUCCESS;
 347     else
 348     {
 349         /* Build self-referential control URL */
 350         char ip[NI_MAXNUMERICHOST], *ptr;
 351
 352         httpd_ServerIP( cl, ip );
 353         ptr = strchr( ip, '%' );
 354         if( ptr != NULL )
 355             *ptr = '\0';
 356
 357         if( strchr( ip, ':' ) != NULL )
 358             sprintf( control, "rtsp://[%s]:%u%s", ip, rtsp->port,
 359                      rtsp->psz_path );
 360         else
 361             sprintf( control, "rtsp://%s:%u%s", ip, rtsp->port,
 362                      rtsp->psz_path );
 363     }
 364
 365     /* */
 366     answer->i_proto = HTTPD_PROTO_RTSP;
 367     answer->i_version= 0;
 368     answer->i_type   = HTTPD_MSG_ANSWER;
 369     answer->i_body = 0;
 370     answer->p_body = NULL;
 371
 372     if( httpd_MsgGet( query, "Require" ) != NULL )
 373     {
 374         answer->i_status = 551;
 375         httpd_MsgAdd( answer, "Unsupported", "%s",
 376                       httpd_MsgGet( query, "Require" ) );
 377     }
 378     else
 379     switch( query->i_type )
 380     {
 381         case HTTPD_MSG_DESCRIBE:
 382         {   /* Aggregate-only */
 383             if( id != NULL )
 384             {
 385                 answer->i_status = 460;
 386                 break;
 387             }
 388
 389             answer->i_status = 200;
 390             httpd_MsgAdd( answer, "Content-Type",  "%s", "application/sdp" );
 391             httpd_MsgAdd( answer, "Content-Base",  "%s", control );
 392             answer->p_body = (uint8_t *)SDPGenerate( rtsp->owner, control );
 393             if( answer->p_body != NULL )
 394                 answer->i_body = strlen( (char *)answer->p_body );
 395             else
 396                 answer->i_status = 500;
 397             break;
 398         }
 399
 400         case HTTPD_MSG_SETUP:
 401             /* Non-aggregate-only */
 402             if( id == NULL )
 403             {
 404                 answer->i_status = 459;
 405                 break;
 406             }
 407
 408             psz_session = httpd_MsgGet( query, "Session" );
 409             answer->i_status = 461;
 410
 411             for( const char *tpt = httpd_MsgGet( query, "Transport" );
 412                  tpt != NULL;
 413                  tpt = transport_next( tpt ) )
 414             {
 415                 vlc_bool_t b_multicast = VLC_TRUE, b_unsupp = VLC_FALSE;
 416                 unsigned loport = 5004, hiport = 5005; /* from RFC3551 */
 417
 418                 /* Check transport protocol. */
 419                 /* Currently, we only support RTP/AVP over UDP */
 420                 if( strncmp( tpt, "RTP/AVP", 7 ) )
 421                     continue;
 422                 tpt += 7;
 423                 if( strncmp( tpt, "/UDP", 4 ) == 0 )
 424                     tpt += 4;
 425                 if( strchr( ";,", *tpt ) == NULL )
 426                     continue;
 427
 428                 /* Parse transport options */
 429                 for( const char *opt = parameter_next( tpt );
 430                      opt != NULL;
 431                      opt = parameter_next( opt ) )
 432                 {
 433                     if( strncmp( opt, "multicast", 9 ) == 0)
 434                         b_multicast = VLC_TRUE;
 435                     else
 436                     if( strncmp( opt, "unicast", 7 ) == 0 )
 437                         b_multicast = VLC_FALSE;
 438                     else
 439                     if( sscanf( opt, "client_port=%u-%u", &loport, &hiport )
 440                                 == 2 )
 441                         ;
 442                     else
 443                     if( strncmp( opt, "mode=", 5 ) == 0 )
 444                     {
 445                         if( strncasecmp( opt + 5, "play", 4 )
 446                          && strncasecmp( opt + 5, "\"PLAY\"", 6 ) )
 447                         {
 448                             /* Not playing?! */
 449                             b_unsupp = VLC_TRUE;
 450                             break;
 451                         }
 452                     }
 453                     else
 454                     if( strncmp( opt,"destination=", 12 ) == 0 )
 455                     {
 456                         answer->i_status = 403;
 457                         b_unsupp = VLC_TRUE;
 458                     }
 459                     else
 460                     {
 461                     /*
 462                      * Every other option is unsupported:
 463                      *
 464                      * "source" and "append" are invalid (server-only);
 465                      * "ssrc" also (as clarified per RFC2326bis).
 466                      *
 467                      * For multicast, "port", "layers", "ttl" are set by the
 468                      * stream output configuration.
 469                      *
 470                      * For unicast, we want to decide "server_port" values.
 471                      *
 472                      * "interleaved" is not implemented.
 473                      */
 474                         b_unsupp = VLC_TRUE;
 475                         break;
 476                     }
 477                 }
 478
 479                 if( b_unsupp )
 480                     continue;
 481
 482                 if( b_multicast )
 483                 {
 484                     const char *dst = id->dst;
 485                     if( dst == NULL )
 486                         continue;
 487
 488                     if( psz_session == NULL )
 489                     {
 490                         /* Create a dummy session ID */
 491                         snprintf( psz_sesbuf, sizeof( psz_sesbuf ), "%d",
 492                                   rand() );
 493                         psz_session = psz_sesbuf;
 494                     }
 495                     answer->i_status = 200;
 496
 497                     httpd_MsgAdd( answer, "Transport",
 498                                   "RTP/AVP/UDP;destination=%s;port=%u-%u;"
 499                                   "ttl=%d;mode=play",
 500                                   dst, id->loport, id->hiport,
 501                                   ( id->ttl > 0 ) ? id->ttl : 1 );
 502                 }
 503                 else
 504                 {
 505                     char ip[NI_MAXNUMERICHOST], src[NI_MAXNUMERICHOST];
 506                     rtsp_session_t *ses = NULL;
 507                     rtsp_strack_t track = { id->sout_id, -1, VLC_FALSE };
 508                     int sport;
 509
 510                     if( httpd_ClientIP( cl, ip ) == NULL )
 511                     {
 512                         answer->i_status = 500;
 513                         continue;
 514                     }
 515
 516                     track.fd = net_ConnectDgram( p_stream, ip, loport, -1,
 517                                                  IPPROTO_UDP );
 518                     if( track.fd == -1 )
 519                     {
 520                         msg_Err( p_stream,
 521                                  "cannot create RTP socket for %s port %u",
 522                                  ip, loport );
 523                         answer->i_status = 500;
 524                         continue;
 525                     }
 526
 527                     net_GetSockAddress( track.fd, src, &sport );
 528
 529                     vlc_mutex_lock( &rtsp->lock );
 530                     if( psz_session == NULL )
 531                     {
 532                         ses = RtspClientNew( rtsp );
 533                         snprintf( psz_sesbuf, sizeof( psz_sesbuf ), I64Fx,
 534                                   ses->id );
 535                         psz_session = psz_sesbuf;
 536                     }
 537                     else
 538                     {
 539                         /* FIXME: we probably need to remove an access out,
 540                          * if there is already one for the same ID */
 541                         ses = RtspClientGet( rtsp, psz_session );
 542                         if( ses == NULL )
 543                         {
 544                             answer->i_status = 454;
 545                             vlc_mutex_unlock( &rtsp->lock );
 546                             continue;
 547                         }
 548                     }
 549
 550                     INSERT_ELEM( ses->trackv, ses->trackc, ses->trackc,
 551                                  track );
 552                     vlc_mutex_unlock( &rtsp->lock );
 553
 554                     httpd_ServerIP( cl, ip );
 555
 556                     if( strcmp( src, ip ) )
 557                     {
 558                         /* Specify source IP if it is different from the RTSP
 559                          * control connection server address */
 560                         char *ptr = strchr( src, '%' );
 561                         if( ptr != NULL ) *ptr = '\0'; /* remove scope ID */
 562
 563                         httpd_MsgAdd( answer, "Transport",
 564                                       "RTP/AVP/UDP;unicast;source=%s;"
 565                                       "client_port=%u-%u;server_port=%u-%u;"
 566                                       "mode=play",
 567                                       src, loport, loport + 1, sport,
 568                                       sport + 1 );
 569                     }
 570                     else
 571                     {
 572                         httpd_MsgAdd( answer, "Transport",
 573                                       "RTP/AVP/UDP;unicast;"
 574                                       "client_port=%u-%u;server_port=%u-%u;"
 575                                       "mode=play",
 576                                       loport, loport + 1, sport, sport + 1 );
 577                     }
 578
 579                     answer->i_status = 200;
 580                 }
 581                 break;
 582             }
 583             break;
 584
 585         case HTTPD_MSG_PLAY:
 586         {
 587             rtsp_session_t *ses;
 588             answer->i_status = 200;
 589
 590             psz_session = httpd_MsgGet( query, "Session" );
 591             if( httpd_MsgGet( query, "Range" ) != NULL )
 592             {
 593                 answer->i_status = 456; /* cannot seek */
 594                 break;
 595             }
 596
 597             vlc_mutex_lock( &rtsp->lock );
 598             ses = RtspClientGet( rtsp, psz_session );
 599             if( ses != NULL )
 600             {
 601                 for( int i = 0; i < ses->trackc; i++ )
 602                 {
 603                     rtsp_strack_t *tr = ses->trackv + i;
 604                     if( !tr->playing
 605                      && ( ( id == NULL ) || ( tr->id == id->sout_id ) ) )
 606                     {
 607                         tr->playing = VLC_TRUE;
 608                         rtp_add_sink( tr->id, tr->fd, VLC_FALSE );
 609                     }
 610                 }
 611             }
 612             vlc_mutex_unlock( &rtsp->lock );
 613
 614             if( httpd_MsgGet( query, "Scale" ) != NULL )
 615                 httpd_MsgAdd( answer, "Scale", "1." );
 616             break;
 617         }
 618
 619         case HTTPD_MSG_PAUSE:
 620             answer->i_status = 405;
 621             httpd_MsgAdd( answer, "Allow",
 622                           "%s, TEARDOWN, PLAY, GET_PARAMETER",
 623                           ( id != NULL ) ? "SETUP" : "DESCRIBE" );
 624             break;
 625
 626         case HTTPD_MSG_GETPARAMETER:
 627             if( query->i_body > 0 )
 628             {
 629                 answer->i_status = 451;
 630                 break;
 631             }
 632
 633             psz_session = httpd_MsgGet( query, "Session" );
 634             answer->i_status = 200;
 635             break;
 636
 637         case HTTPD_MSG_TEARDOWN:
 638         {
 639             rtsp_session_t *ses;
 640
 641             answer->i_status = 200;
 642
 643             psz_session = httpd_MsgGet( query, "Session" );
 644
 645             vlc_mutex_lock( &rtsp->lock );
 646             ses = RtspClientGet( rtsp, psz_session );
 647             if( ses != NULL )
 648             {
 649                 if( id == NULL ) /* Delete the entire session */
 650                     RtspClientDel( rtsp, ses );
 651                 else /* Delete one track from the session */
 652                 for( int i = 0; i < ses->trackc; i++ )
 653                 {
 654                     if( ses->trackv[i].id == id->sout_id )
 655                     {
 656                         rtp_del_sink( id->sout_id, ses->trackv[i].fd );
 657                         REMOVE_ELEM( ses->trackv, ses->trackc, i );
 658                     }
 659                 }
 660             }
 661             vlc_mutex_unlock( &rtsp->lock );
 662             break;
 663         }
 664
 665         default:
 666             return VLC_EGENERIC;
 667     }
 668
 669     httpd_MsgAdd( answer, "Server", "%s", PACKAGE_STRING );
 670     if( psz_session )
 671         httpd_MsgAdd( answer, "Session", "%s"/*;timeout=5*/, psz_session );
 672
 673     httpd_MsgAdd( answer, "Content-Length", "%d", answer->i_body );
 674     httpd_MsgAdd( answer, "Cache-Control", "no-cache" );
 675
 676     psz = httpd_MsgGet( query, "Cseq" );
 677     if( psz != NULL )
 678         httpd_MsgAdd( answer, "Cseq", "%s", psz );
 679     psz = httpd_MsgGet( query, "Timestamp" );
 680     if( psz != NULL )
 681         httpd_MsgAdd( answer, "Timestamp", "%s", psz );
 682
 683     return VLC_SUCCESS;
 684 }
 685
 686
 687 /** Aggregate RTSP callback */
 688 static int RtspCallback( httpd_callback_sys_t *p_args,
 689                          httpd_client_t *cl,
 690                          httpd_message_t *answer,
 691                          const httpd_message_t *query )
 692 {
 693     return RtspHandler( (rtsp_stream_t *)p_args, NULL, cl, answer, query );
 694 }
 695
 696
 697 /** Non-aggregate RTSP callback */
 698 static int RtspCallbackId( httpd_callback_sys_t *p_args,
 699                            httpd_client_t *cl,
 700                            httpd_message_t *answer,
 701                            const httpd_message_t *query )
 702 {
 703     rtsp_stream_id_t *id = (rtsp_stream_id_t *)p_args;
 704     return RtspHandler( id->stream, id, cl, answer, query );
 705 }