git.sesse.net Git - vlc/blob - src/stream_output/sap.c

   1 /*****************************************************************************
   2  * sap.c : SAP announce handler
   3  *****************************************************************************
   4  * Copyright (C) 2002-2005 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Clément Stenac <zorglub@videolan.org>
   8  *          Rémi Denis-Courmont <rem # videolan.org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #include <stdlib.h>                                                /* free() */
  29 #include <stdio.h>                                              /* sprintf() */
  30 #include <string.h>                                            /* strerror() */
  31 #include <ctype.h>                                  /* tolower(), isxdigit() */
  32
  33 #include <vlc/vlc.h>
  34 #include <vlc/sout.h>
  35
  36 #include "network.h"
  37 #include "charset.h"
  38
  39 /* SAP is always on that port */
  40 #define SAP_PORT 9875
  41
  42 #define DEFAULT_PORT "1234"
  43
  44 #undef EXTRA_DEBUG
  45
  46 /* SAP Specific structures */
  47
  48 /* 100ms */
  49 #define SAP_IDLE ((mtime_t)(0.100*CLOCK_FREQ))
  50 #define SAP_MAX_BUFFER 65534
  51 #define MIN_INTERVAL 2
  52 #define MAX_INTERVAL 300
  53
  54 /* A SAP announce address. For each of these, we run the
  55  * control flow algorithm */
  56 struct sap_address_t
  57 {
  58     char *psz_address;
  59     char psz_machine[NI_MAXNUMERICHOST];
  60     int i_rfd; /* Read socket */
  61     int i_wfd; /* Write socket */
  62
  63     /* Used for flow control */
  64     mtime_t t1;
  65     vlc_bool_t b_enabled;
  66     vlc_bool_t b_ready;
  67     int i_interval;
  68     int i_buff;
  69     int i_limit;
  70 };
  71
  72 /*****************************************************************************
  73  * Local prototypes
  74  *****************************************************************************/
  75 static void RunThread( vlc_object_t *p_this);
  76 static int CalculateRate( sap_handler_t *p_sap, sap_address_t *p_address );
  77 static char *SDPGenerate( sap_handler_t *p_sap,
  78                           const session_descriptor_t *p_session,
  79                           const sap_address_t *p_addr );
  80
  81 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
  82                                      sap_session_t *p_session );
  83
  84
  85 static int announce_SAPAnnounceAdd( sap_handler_t *p_sap,
  86                              session_descriptor_t *p_session );
  87
  88 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
  89                              session_descriptor_t *p_session );
  90
  91
  92 /**
  93  * Create the SAP handler
  94  *
  95  * \param p_announce the parent announce_handler
  96  * \return the newly created SAP handler or NULL on error
  97  */
  98 sap_handler_t *announce_SAPHandlerCreate( announce_handler_t *p_announce )
  99 {
 100     sap_handler_t *p_sap;
 101
 102     p_sap = vlc_object_create( p_announce, sizeof( sap_handler_t ) );
 103
 104     if( !p_sap )
 105     {
 106         msg_Err( p_announce, "out of memory" );
 107         return NULL;
 108     }
 109
 110     vlc_mutex_init( p_sap, &p_sap->object_lock );
 111
 112     p_sap->pf_add = announce_SAPAnnounceAdd;
 113     p_sap->pf_del = announce_SAPAnnounceDel;
 114
 115     p_sap->i_sessions = 0;
 116     p_sap->i_addresses = 0;
 117     p_sap->i_current_session = 0;
 118
 119     p_sap->b_control = config_GetInt( p_sap, "sap-flow-control");
 120
 121     if( vlc_thread_create( p_sap, "sap handler", RunThread,
 122                        VLC_THREAD_PRIORITY_LOW, VLC_FALSE ) )
 123     {
 124         msg_Dbg( p_announce, "unable to spawn SAP handler thread");
 125         free( p_sap );
 126         return NULL;
 127     };
 128     msg_Dbg( p_announce, "thread created, %i sessions", p_sap->i_sessions);
 129     return p_sap;
 130 }
 131
 132 /**
 133  *  Destroy the SAP handler
 134  *  \param p_this the SAP Handler to destroy
 135  *  \return nothing
 136  */
 137 void announce_SAPHandlerDestroy( sap_handler_t *p_sap )
 138 {
 139     int i;
 140
 141     vlc_mutex_destroy( &p_sap->object_lock );
 142
 143     /* Free the remaining sessions */
 144     for( i = 0 ; i< p_sap->i_sessions ; i++)
 145     {
 146         sap_session_t *p_session = p_sap->pp_sessions[i];
 147         FREENULL( p_session->psz_sdp );
 148         FREENULL( p_session->psz_data );
 149         REMOVE_ELEM( p_sap->pp_sessions, p_sap->i_sessions , i );
 150         FREENULL( p_session );
 151     }
 152
 153     /* Free the remaining addresses */
 154     for( i = 0 ; i< p_sap->i_addresses ; i++)
 155     {
 156         sap_address_t *p_address = p_sap->pp_addresses[i];
 157         FREENULL( p_address->psz_address );
 158         if( p_address->i_rfd > -1 )
 159         {
 160             net_Close( p_address->i_rfd );
 161         }
 162         if( p_address->i_wfd > -1 && p_sap->b_control )
 163         {
 164             net_Close( p_address->i_wfd );
 165         }
 166         REMOVE_ELEM( p_sap->pp_addresses, p_sap->i_addresses, i );
 167         FREENULL( p_address );
 168     }
 169
 170     /* Free the structure */
 171     vlc_object_destroy( p_sap );
 172 }
 173
 174 /**
 175  * main SAP handler thread
 176  * \param p_this the SAP Handler object
 177  * \return nothing
 178  */
 179 static void RunThread( vlc_object_t *p_this)
 180 {
 181     sap_handler_t *p_sap = (sap_handler_t*)p_this;
 182     sap_session_t *p_session;
 183
 184     while( !p_sap->b_die )
 185     {
 186         int i;
 187
 188         /* If needed, get the rate info */
 189         if( p_sap->b_control == VLC_TRUE )
 190         {
 191             for( i = 0 ; i< p_sap->i_addresses ; i++)
 192             {
 193                 if( p_sap->pp_addresses[i]->b_enabled == VLC_TRUE )
 194                 {
 195                     CalculateRate( p_sap, p_sap->pp_addresses[i] );
 196                 }
 197             }
 198         }
 199
 200         /* Find the session to announce */
 201         vlc_mutex_lock( &p_sap->object_lock );
 202         if( p_sap->i_sessions > p_sap->i_current_session + 1)
 203         {
 204             p_sap->i_current_session++;
 205         }
 206         else if( p_sap->i_sessions > 0)
 207         {
 208             p_sap->i_current_session = 0;
 209         }
 210         else
 211         {
 212             vlc_mutex_unlock( &p_sap->object_lock );
 213             msleep( SAP_IDLE );
 214             continue;
 215         }
 216         p_session = p_sap->pp_sessions[p_sap->i_current_session];
 217         vlc_mutex_unlock( &p_sap->object_lock );
 218
 219         /* And announce it */
 220         if( p_session->p_address->b_enabled == VLC_TRUE &&
 221             p_session->p_address->b_ready == VLC_TRUE )
 222         {
 223             announce_SendSAPAnnounce( p_sap, p_session );
 224         }
 225
 226         msleep( SAP_IDLE );
 227     }
 228 }
 229
 230 /* Add a SAP announce */
 231 static int announce_SAPAnnounceAdd( sap_handler_t *p_sap,
 232                              session_descriptor_t *p_session )
 233 {
 234     int i_header_size, i;
 235     char *psz_head, psz_addr[NI_MAXNUMERICHOST];
 236     vlc_bool_t b_ipv6 = VLC_FALSE;
 237     sap_session_t *p_sap_session;
 238     mtime_t i_hash;
 239     struct addrinfo hints, *res;
 240     struct sockaddr_storage addr;
 241
 242     vlc_mutex_lock( &p_sap->object_lock );
 243
 244     if( p_session->psz_uri == NULL )
 245     {
 246         vlc_mutex_unlock( &p_sap->object_lock );
 247         msg_Err( p_sap, "*FIXME* unexpected NULL URI for SAP announce" );
 248         msg_Err( p_sap, "This should not happen. VLC needs fixing." );
 249         return VLC_EGENERIC;
 250     }
 251
 252     /* Determine SAP multicast address automatically */
 253     memset( &hints, 0, sizeof( hints ) );
 254     hints.ai_socktype = SOCK_DGRAM;
 255     hints.ai_flags = AI_NUMERICHOST;
 256
 257     i = vlc_getaddrinfo( (vlc_object_t *)p_sap, p_session->psz_uri, 0,
 258                          &hints, &res );
 259     if( i )
 260     {
 261         vlc_mutex_unlock( &p_sap->object_lock );
 262         msg_Err( p_sap, "Invalid URI for SAP announce: %s: %s",
 263                  p_session->psz_uri, vlc_gai_strerror( i ) );
 264         return VLC_EGENERIC;
 265     }
 266
 267     if( (unsigned)res->ai_addrlen > sizeof( addr ) )
 268     {
 269         vlc_mutex_unlock( &p_sap->object_lock );
 270         vlc_freeaddrinfo( res );
 271         msg_Err( p_sap, "Unsupported address family of size %d > %u",
 272                  res->ai_addrlen, (unsigned) sizeof( addr ) );
 273         return VLC_EGENERIC;
 274     }
 275
 276     memcpy( &addr, res->ai_addr, res->ai_addrlen );
 277
 278     switch( addr.ss_family )
 279     {
 280 #if defined (HAVE_INET_PTON) || defined (WIN32)
 281         case AF_INET6:
 282         {
 283             /* See RFC3513 for list of valid IPv6 scopes */
 284             struct in6_addr *a6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
 285
 286             memcpy( a6->s6_addr + 2, "\x00\x00\x00\x00\x00\x00"
 287                    "\x00\x00\x00\x00\x00\x02\x7f\xfe", 14 );
 288             if( IN6_IS_ADDR_MULTICAST( a6 ) )
 289                  /* force flags to zero, preserve scope */
 290                 a6->s6_addr[1] &= 0xf;
 291             else
 292                 /* Unicast IPv6 - assume global scope */
 293                 memcpy( a6->s6_addr, "\xff\x0e", 2 );
 294
 295             b_ipv6 = VLC_TRUE;
 296             break;
 297         }
 298 #endif
 299
 300         case AF_INET:
 301         {
 302             /* See RFC2365 for IPv4 scopes */
 303             uint32_t ipv4;
 304
 305             ipv4 = ntohl( ((struct sockaddr_in *)&addr)->sin_addr.s_addr );
 306             /* 224.0.0.0/24 => 224.0.0.255 */
 307             if ((ipv4 & 0xffffff00) == 0xe0000000)
 308                 ipv4 =  0xe00000ff;
 309             else
 310             /* 239.255.0.0/16 => 239.255.255.255 */
 311             if ((ipv4 & 0xffff0000) == 0xefff0000)
 312                 ipv4 =  0xefffffff;
 313             else
 314             /* 239.192.0.0/14 => 239.195.255.255 */
 315             if ((ipv4 & 0xfffc0000) == 0xefc00000)
 316                 ipv4 =  0xefc3ffff;
 317             else
 318             if ((ipv4 & 0xff000000) == 0xef000000)
 319                 ipv4 = 0;
 320             else
 321             /* other addresses => 224.2.127.254 */
 322                 ipv4 = 0xe0027ffe;
 323
 324             if( ipv4 == 0 )
 325             {
 326                 msg_Err( p_sap, "Out-of-scope multicast address "
 327                         "not supported by SAP: %s", p_session->psz_uri );
 328                 vlc_mutex_unlock( &p_sap->object_lock );
 329                 vlc_freeaddrinfo( res );
 330                 return VLC_EGENERIC;
 331             }
 332
 333             ((struct sockaddr_in *)&addr)->sin_addr.s_addr = htonl( ipv4 );
 334             break;
 335         }
 336
 337         default:
 338             vlc_mutex_unlock( &p_sap->object_lock );
 339             vlc_freeaddrinfo( res );
 340             msg_Err( p_sap, "Address family %d not supported by SAP",
 341                      addr.ss_family );
 342             return VLC_EGENERIC;
 343     }
 344
 345     i = vlc_getnameinfo( (struct sockaddr *)&addr, res->ai_addrlen,
 346                          psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );
 347     vlc_freeaddrinfo( res );
 348
 349     if( i )
 350     {
 351         vlc_mutex_unlock( &p_sap->object_lock );
 352         msg_Err( p_sap, "%s", vlc_gai_strerror( i ) );
 353         return VLC_EGENERIC;
 354     }
 355
 356     msg_Dbg( p_sap, "using SAP address: %s", psz_addr);
 357
 358     /* XXX: Check for dupes */
 359     p_sap_session = (sap_session_t*)malloc(sizeof(sap_session_t));
 360     p_sap_session->p_address = NULL;
 361
 362     /* Add the address to the buffer */
 363     for( i = 0; i < p_sap->i_addresses; i++)
 364     {
 365         if( !strcmp( psz_addr, p_sap->pp_addresses[i]->psz_address ) )
 366         {
 367             p_sap_session->p_address = p_sap->pp_addresses[i];
 368             break;
 369         }
 370     }
 371
 372     if( p_sap_session->p_address == NULL )
 373     {
 374         sap_address_t *p_address = (sap_address_t *)
 375                                     malloc( sizeof(sap_address_t) );
 376         if( !p_address )
 377         {
 378             msg_Err( p_sap, "out of memory" );
 379             return VLC_ENOMEM;
 380         }
 381         p_address->psz_address = strdup( psz_addr );
 382         p_address->i_wfd = net_ConnectUDP( p_sap, psz_addr, SAP_PORT, 255 );
 383         if( p_address->i_wfd != -1 )
 384         {
 385             char *ptr;
 386
 387             net_StopRecv( p_address->i_wfd );
 388             net_GetSockAddress( p_address->i_wfd, p_address->psz_machine,
 389                                 NULL );
 390
 391             /* removes scope if present */
 392             ptr = strchr( p_address->psz_machine, '%' );
 393             if( ptr != NULL )
 394                 *ptr = '\0';
 395         }
 396
 397         if( p_sap->b_control == VLC_TRUE )
 398         {
 399             p_address->i_rfd = net_OpenUDP( p_sap, psz_addr, SAP_PORT, "", 0 );
 400             if( p_address->i_rfd != -1 )
 401                 net_StopSend( p_address->i_rfd );
 402             p_address->i_buff = 0;
 403             p_address->b_enabled = VLC_TRUE;
 404             p_address->b_ready = VLC_FALSE;
 405             p_address->i_limit = 10000; /* 10000 bps */
 406             p_address->t1 = 0;
 407         }
 408         else
 409         {
 410             p_address->b_enabled = VLC_TRUE;
 411             p_address->b_ready = VLC_TRUE;
 412             p_address->i_interval = config_GetInt( p_sap,"sap-interval");
 413             p_address->i_rfd = -1;
 414         }
 415
 416         if( p_address->i_wfd == -1 || (p_address->i_rfd == -1
 417                                         && p_sap->b_control ) )
 418         {
 419             msg_Warn( p_sap, "disabling address" );
 420             p_address->b_enabled = VLC_FALSE;
 421         }
 422
 423         INSERT_ELEM( p_sap->pp_addresses,
 424                      p_sap->i_addresses,
 425                      p_sap->i_addresses,
 426                      p_address );
 427         p_sap_session->p_address = p_address;
 428     }
 429
 430
 431     /* Build the SAP Headers */
 432     i_header_size = ( b_ipv6 ? 16 : 4 ) + 20;
 433     psz_head = (char *) malloc( i_header_size * sizeof( char ) );
 434     if( psz_head == NULL )
 435     {
 436         msg_Err( p_sap, "out of memory" );
 437         return VLC_ENOMEM;
 438     }
 439
 440     /* SAPv1, not encrypted, not compressed */
 441     psz_head[0] = b_ipv6 ? 0x30 : 0x20;
 442     psz_head[1] = 0x00; /* No authentification length */
 443
 444     i_hash = mdate();
 445     psz_head[2] = (i_hash & 0xFF00) >> 8; /* Msg id hash */
 446     psz_head[3] = (i_hash & 0xFF);        /* Msg id hash 2 */
 447
 448 #if defined (HAVE_INET_PTON) || defined (WIN32)
 449     if( b_ipv6 )
 450     {
 451         inet_pton( AF_INET6, /* can't fail */
 452                    p_sap_session->p_address->psz_machine,
 453                    psz_head + 4 );
 454     }
 455     else
 456 #endif
 457     {
 458         inet_pton( AF_INET, /* can't fail */
 459                    p_sap_session->p_address->psz_machine,
 460                    psz_head + 4 );
 461     }
 462
 463     memcpy( psz_head + (b_ipv6 ? 20 : 8), "application/sdp", 15 );
 464
 465     /* If needed, build the SDP */
 466     if( p_session->psz_sdp == NULL )
 467     {
 468         p_session->psz_sdp = SDPGenerate( p_sap, p_session,
 469                                           p_sap_session->p_address );
 470         if( p_session->psz_sdp == NULL )
 471         {
 472             vlc_mutex_unlock( &p_sap->object_lock );
 473             return VLC_ENOMEM;
 474         }
 475     }
 476
 477     p_sap_session->psz_sdp = strdup( p_session->psz_sdp );
 478     p_sap_session->i_last = 0;
 479
 480     psz_head[ i_header_size-1 ] = '\0';
 481     p_sap_session->i_length = i_header_size + strlen( p_sap_session->psz_sdp);
 482
 483     p_sap_session->psz_data = (uint8_t *)malloc( sizeof(char)*
 484                                                  p_sap_session->i_length );
 485
 486     /* Build the final message */
 487     memcpy( p_sap_session->psz_data, psz_head, i_header_size );
 488     memcpy( p_sap_session->psz_data+i_header_size, p_sap_session->psz_sdp,
 489             strlen( p_sap_session->psz_sdp) );
 490
 491     free( psz_head );
 492
 493     /* Enqueue the announce */
 494     INSERT_ELEM( p_sap->pp_sessions,
 495                  p_sap->i_sessions,
 496                  p_sap->i_sessions,
 497                  p_sap_session );
 498     msg_Dbg( p_sap,"%i addresses, %i sessions",
 499                    p_sap->i_addresses,p_sap->i_sessions);
 500
 501     /* Remember the SAP session for later deletion */
 502     p_session->p_sap = p_sap_session;
 503
 504     vlc_mutex_unlock( &p_sap->object_lock );
 505
 506     return VLC_SUCCESS;
 507 }
 508
 509 /* Remove a SAP Announce */
 510 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
 511                              session_descriptor_t *p_session )
 512 {
 513     int i;
 514     vlc_mutex_lock( &p_sap->object_lock );
 515
 516     msg_Dbg( p_sap,"removing SAP announce %p",p_session->p_sap);
 517
 518     /* Dequeue the announce */
 519     for( i = 0; i< p_sap->i_sessions; i++)
 520     {
 521         if( p_session->p_sap == p_sap->pp_sessions[i] )
 522         {
 523             REMOVE_ELEM( p_sap->pp_sessions,
 524                          p_sap->i_sessions,
 525                          i );
 526
 527             FREENULL( p_session->p_sap->psz_sdp );
 528             FREENULL( p_session->p_sap->psz_data );
 529             free( p_session->p_sap );
 530             break;
 531         }
 532     }
 533
 534     /* XXX: Dequeue the address too if it is not used anymore
 535      * TODO: - address refcount
 536              - send a SAP deletion packet */
 537
 538     msg_Dbg( p_sap,"%i announcements remaining", p_sap->i_sessions );
 539
 540     vlc_mutex_unlock( &p_sap->object_lock );
 541
 542     return VLC_SUCCESS;
 543 }
 544
 545 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
 546                                      sap_session_t *p_session )
 547 {
 548     int i_ret;
 549
 550     /* This announce has never been sent yet */
 551     if( p_session->i_last == 0 )
 552     {
 553         p_session->i_next = mdate()+ p_session->p_address->i_interval*1000000;
 554         p_session->i_last = 1;
 555         return VLC_SUCCESS;
 556     }
 557
 558     if( p_session->i_next < mdate() )
 559     {
 560 #ifdef EXTRA_DEBUG
 561         msg_Dbg( p_sap, "sending announce");
 562 #endif
 563         i_ret = net_Write( p_sap, p_session->p_address->i_wfd, NULL,
 564                            p_session->psz_data,
 565                            p_session->i_length );
 566         if( i_ret != (int)p_session->i_length )
 567         {
 568             msg_Warn( p_sap, "SAP send failed on address %s (%i %i)",
 569                       p_session->p_address->psz_address,
 570                       i_ret, p_session->i_length );
 571         }
 572         p_session->i_last = p_session->i_next;
 573         p_session->i_next = p_session->i_last
 574                             + p_session->p_address->i_interval*1000000;
 575     }
 576     else
 577     {
 578         return VLC_SUCCESS;
 579     }
 580     return VLC_SUCCESS;
 581 }
 582
 583 static char *SDPGenerate( sap_handler_t *p_sap,
 584                           const session_descriptor_t *p_session,
 585                           const sap_address_t *p_addr )
 586 {
 587     int64_t i_sdp_id = mdate();
 588     int     i_sdp_version = 1 + p_sap->i_sessions + (rand()&0xfff);
 589     char *psz_group, *psz_name, psz_uribuf[NI_MAXNUMERICHOST], *psz_uri,
 590          *psz_sdp;
 591     char ipv;
 592
 593     psz_group = p_session->psz_group;
 594     psz_name = p_session->psz_name;
 595
 596     /* FIXME: really check that psz_uri is a real IP address
 597      * FIXME: make a common function to obtain a canonical IP address */
 598     ipv = ( strchr( p_session->psz_uri, ':' )  != NULL) ? '6' : '4';
 599     if( *p_session->psz_uri == '[' )
 600     {
 601         char *ptr;
 602
 603         strlcpy( psz_uribuf, p_session->psz_uri + 1, sizeof( psz_uribuf ) );
 604         ptr = strchr( psz_uribuf, '%' );
 605         if( ptr != NULL)
 606             *ptr = '\0';
 607         ptr = strchr( psz_uribuf, ']' );
 608         if( ptr != NULL)
 609             *ptr = '\0';
 610         psz_uri = psz_uribuf;
 611     }
 612     else
 613         psz_uri = p_session->psz_uri;
 614
 615     /* see the lists in modules/stream_out/rtp.c for compliance stuff */
 616     if( asprintf( &psz_sdp,
 617                             "v=0\r\n"
 618                             "o=- "I64Fd" %d IN IP%c %s\r\n"
 619                             "s=%s\r\n"
 620                             "c=IN IP%c %s/%d\r\n"
 621                             "a=tool:"PACKAGE_STRING"\r\n"
 622                             "t=0 0\r\n"
 623                             "m=video %d %s %d\r\n"
 624                             "a=type:broadcast\r\n"
 625                             "%s%s%s",
 626                             i_sdp_id, i_sdp_version,
 627                             ipv, p_addr->psz_machine,
 628                             psz_name, ipv, psz_uri,
 629                             /* FIXME: 1 is IPv4 default TTL, not that of IPv6 */
 630                             p_session->i_ttl ?: (config_GetInt( p_sap, "ttl" ) ?: 1),
 631                             p_session->i_port,
 632                             p_session->b_rtp ? "RTP/AVP" : "udp",
 633                             p_session->i_payload,
 634                             psz_group ? "a=x-plgroup:" : "",
 635                             psz_group ? psz_group : "", psz_group ? "\r\n" : "" ) == -1 )
 636         return NULL;
 637
 638     msg_Dbg( p_sap, "Generated SDP (%i bytes):\n%s", strlen(psz_sdp),
 639              psz_sdp );
 640     return psz_sdp;
 641 }
 642
 643 static int CalculateRate( sap_handler_t *p_sap, sap_address_t *p_address )
 644 {
 645     int i_read;
 646     uint8_t buffer[SAP_MAX_BUFFER];
 647     int i_tot = 0;
 648     mtime_t i_temp;
 649     int i_rate;
 650
 651     if( p_address->t1 == 0 )
 652     {
 653         p_address->t1 = mdate();
 654         return VLC_SUCCESS;
 655     }
 656     do
 657     {
 658         /* Might be too slow if we have huge data */
 659         i_read = net_ReadNonBlock( p_sap, p_address->i_rfd, NULL, buffer,
 660                                    SAP_MAX_BUFFER, 0 );
 661         i_tot += i_read;
 662     } while( i_read > 0 && i_tot < SAP_MAX_BUFFER );
 663
 664     i_temp = mdate();
 665
 666     /* We calculate the rate every 5 seconds */
 667     if( i_temp - p_address->t1 < 5000000 )
 668     {
 669         p_address->i_buff += i_tot;
 670         return VLC_SUCCESS;
 671     }
 672
 673     /* Bits/second */
 674     i_rate = (int)(8*1000000*((mtime_t)p_address->i_buff + (mtime_t)i_tot ) /
 675                         (i_temp - p_address->t1 ));
 676
 677     p_address->i_limit = 10000;
 678
 679     p_address->i_interval = ((1000*i_rate / p_address->i_limit) *
 680                             (MAX_INTERVAL - MIN_INTERVAL))/1000 + MIN_INTERVAL;
 681
 682     if( p_address->i_interval > MAX_INTERVAL || p_address->i_interval < 0 )
 683     {
 684         p_address->i_interval = MAX_INTERVAL;
 685     }
 686 #ifdef EXTRA_DEBUG
 687     msg_Dbg( p_sap,"%s:%i: rate=%i, interval = %i s",
 688              p_address->psz_address,SAP_PORT, i_rate, p_address->i_interval );
 689 #endif
 690
 691     p_address->b_ready = VLC_TRUE;
 692
 693     p_address->t1 = i_temp;
 694     p_address->i_buff = 0;
 695
 696     return VLC_SUCCESS;
 697 }