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., 59 Temple Place - Suite 330, Boston, MA  02111, 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 #if defined( WIN32 ) || defined( UNDER_CE )
  38 #   if defined(UNDER_CE) && defined(sockaddr_storage)
  39 #       undef sockaddr_storage
  40 #   endif
  41 #   include <winsock2.h>
  42 #   include <ws2tcpip.h>
  43 #else
  44 #   include <netdb.h>
  45 #   ifdef HAVE_ARPA_INET_H
  46 #       include <arpa/inet.h>
  47 #   endif
  48 #endif
  49 #include "charset.h"
  50
  51 /* SAP is always on that port */
  52 #define SAP_PORT 9875
  53
  54 #define DEFAULT_PORT "1234"
  55
  56 #undef EXTRA_DEBUG
  57
  58 /* SAP Specific structures */
  59
  60 /* 100ms */
  61 #define SAP_IDLE ((mtime_t)(0.100*CLOCK_FREQ))
  62 #define SAP_MAX_BUFFER 65534
  63 #define MIN_INTERVAL 2
  64 #define MAX_INTERVAL 300
  65
  66 /* A SAP announce address. For each of these, we run the
  67  * control flow algorithm */
  68 struct sap_address_t
  69 {
  70     char *psz_address;
  71     char psz_machine[NI_MAXNUMERICHOST];
  72     int i_port;
  73     int i_rfd; /* Read socket */
  74     int i_wfd; /* Write socket */
  75
  76     /* Used for flow control */
  77     mtime_t t1;
  78     vlc_bool_t b_enabled;
  79     vlc_bool_t b_ready;
  80     int i_interval;
  81     int i_buff;
  82     int i_limit;
  83 };
  84
  85 /*****************************************************************************
  86  * Local prototypes
  87  *****************************************************************************/
  88 static void RunThread( vlc_object_t *p_this);
  89 static int CalculateRate( sap_handler_t *p_sap, sap_address_t *p_address );
  90 static char *SDPGenerate( sap_handler_t *p_sap,
  91                           const session_descriptor_t *p_session,
  92                           const sap_address_t *p_addr );
  93
  94 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
  95                                      sap_session_t *p_session );
  96
  97
  98 static int announce_SAPAnnounceAdd( sap_handler_t *p_sap,
  99                              session_descriptor_t *p_session );
 100
 101 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
 102                              session_descriptor_t *p_session );
 103
 104 #define FREE( p ) if( p ) { free( p ); (p) = NULL; }
 105
 106
 107 /**
 108  * Create the SAP handler
 109  *
 110  * \param p_announce the parent announce_handler
 111  * \return the newly created SAP handler or NULL on error
 112  */
 113 sap_handler_t *announce_SAPHandlerCreate( announce_handler_t *p_announce )
 114 {
 115     sap_handler_t *p_sap;
 116
 117     p_sap = vlc_object_create( p_announce, sizeof( sap_handler_t ) );
 118
 119     if( !p_sap )
 120     {
 121         msg_Err( p_announce, "out of memory" );
 122         return NULL;
 123     }
 124
 125     vlc_mutex_init( p_sap, &p_sap->object_lock );
 126
 127     p_sap->pf_add = announce_SAPAnnounceAdd;
 128     p_sap->pf_del = announce_SAPAnnounceDel;
 129
 130     p_sap->i_sessions = 0;
 131     p_sap->i_addresses = 0;
 132     p_sap->i_current_session = 0;
 133
 134     p_sap->b_control = config_GetInt( p_sap, "sap-flow-control");
 135
 136     if( vlc_thread_create( p_sap, "sap handler", RunThread,
 137                        VLC_THREAD_PRIORITY_LOW, VLC_FALSE ) )
 138     {
 139         msg_Dbg( p_announce, "Unable to spawn SAP handler thread");
 140         free( p_sap );
 141         return NULL;
 142     };
 143     msg_Dbg( p_announce, "thread created, %i sessions", p_sap->i_sessions);
 144     return p_sap;
 145 }
 146
 147 /**
 148  *  Destroy the SAP handler
 149  *  \param p_this the SAP Handler to destroy
 150  *  \return nothing
 151  */
 152 void announce_SAPHandlerDestroy( sap_handler_t *p_sap )
 153 {
 154     int i;
 155
 156     vlc_mutex_destroy( &p_sap->object_lock );
 157
 158     /* Free the remaining sessions */
 159     for( i = 0 ; i< p_sap->i_sessions ; i++)
 160     {
 161         sap_session_t *p_session = p_sap->pp_sessions[i];
 162         FREE( p_session->psz_sdp );
 163         FREE( p_session->psz_data );
 164         REMOVE_ELEM( p_sap->pp_sessions, p_sap->i_sessions , i );
 165         FREE( p_session );
 166     }
 167
 168     /* Free the remaining addresses */
 169     for( i = 0 ; i< p_sap->i_addresses ; i++)
 170     {
 171         sap_address_t *p_address = p_sap->pp_addresses[i];
 172         FREE( p_address->psz_address );
 173         if( p_address->i_rfd > -1 )
 174         {
 175             net_Close( p_address->i_rfd );
 176         }
 177         if( p_address->i_wfd > -1 && p_sap->b_control )
 178         {
 179             net_Close( p_address->i_wfd );
 180         }
 181         REMOVE_ELEM( p_sap->pp_addresses, p_sap->i_addresses, i );
 182         FREE( p_address );
 183     }
 184
 185     /* Free the structure */
 186     vlc_object_destroy( p_sap );
 187 }
 188
 189 /**
 190  * main SAP handler thread
 191  * \param p_this the SAP Handler object
 192  * \return nothing
 193  */
 194 static void RunThread( vlc_object_t *p_this)
 195 {
 196     sap_handler_t *p_sap = (sap_handler_t*)p_this;
 197     sap_session_t *p_session;
 198
 199     while( !p_sap->b_die )
 200     {
 201         int i;
 202
 203         /* If needed, get the rate info */
 204         if( p_sap->b_control == VLC_TRUE )
 205         {
 206             for( i = 0 ; i< p_sap->i_addresses ; i++)
 207             {
 208                 if( p_sap->pp_addresses[i]->b_enabled == VLC_TRUE )
 209                 {
 210                     CalculateRate( p_sap, p_sap->pp_addresses[i] );
 211                 }
 212             }
 213         }
 214
 215         /* Find the session to announce */
 216         vlc_mutex_lock( &p_sap->object_lock );
 217         if( p_sap->i_sessions > p_sap->i_current_session + 1)
 218         {
 219             p_sap->i_current_session++;
 220         }
 221         else if( p_sap->i_sessions > 0)
 222         {
 223             p_sap->i_current_session = 0;
 224         }
 225         else
 226         {
 227             vlc_mutex_unlock( &p_sap->object_lock );
 228             msleep( SAP_IDLE );
 229             continue;
 230         }
 231         p_session = p_sap->pp_sessions[p_sap->i_current_session];
 232         vlc_mutex_unlock( &p_sap->object_lock );
 233
 234         /* And announce it */
 235         if( p_session->p_address->b_enabled == VLC_TRUE &&
 236             p_session->p_address->b_ready == VLC_TRUE )
 237         {
 238             announce_SendSAPAnnounce( p_sap, p_session );
 239         }
 240
 241         msleep( SAP_IDLE );
 242     }
 243 }
 244
 245 /* Add a SAP announce */
 246 static int announce_SAPAnnounceAdd( sap_handler_t *p_sap,
 247                              session_descriptor_t *p_session )
 248 {
 249     int i_header_size, i;
 250     char *psz_head, psz_addr[NI_MAXNUMERICHOST];
 251     vlc_bool_t b_ipv6 = VLC_FALSE;
 252     sap_session_t *p_sap_session;
 253     mtime_t i_hash;
 254     struct addrinfo hints, *res;
 255     struct sockaddr_storage addr;
 256
 257     vlc_mutex_lock( &p_sap->object_lock );
 258
 259     if( p_session->psz_uri == NULL )
 260     {
 261         vlc_mutex_unlock( &p_sap->object_lock );
 262         msg_Err( p_sap, "*FIXME* Unexpected NULL URI for SAP announce" );
 263         msg_Err( p_sap, "This should not happen. VLC needs fixing." );
 264         return VLC_EGENERIC;
 265     }
 266
 267     /* Determine SAP multicast address automatically */
 268     memset( &hints, 0, sizeof( hints ) );
 269     hints.ai_socktype = SOCK_DGRAM;
 270     hints.ai_flags = AI_NUMERICHOST;
 271
 272     i = vlc_getaddrinfo( (vlc_object_t *)p_sap, p_session->psz_uri, 0,
 273                          &hints, &res );
 274     if( i )
 275     {
 276         vlc_mutex_unlock( &p_sap->object_lock );
 277         msg_Err( p_sap, "Invalid URI for SAP announce: %s: %s",
 278                  p_session->psz_uri, vlc_gai_strerror( i ) );
 279         return VLC_EGENERIC;
 280     }
 281
 282     if( (unsigned)res->ai_addrlen > sizeof( addr ) )
 283     {
 284         vlc_mutex_unlock( &p_sap->object_lock );
 285         vlc_freeaddrinfo( res );
 286         msg_Err( p_sap, "Unsupported address family of size %d > %u",
 287                  res->ai_addrlen, sizeof( addr ) );
 288         return VLC_EGENERIC;
 289     }
 290
 291     memcpy( &addr, res->ai_addr, res->ai_addrlen );
 292
 293     switch( addr.ss_family )
 294     {
 295 #if defined (HAVE_INET_PTON) || defined (WIN32)
 296         case AF_INET6:
 297         {
 298             /* See RFC3513 for list of valid IPv6 scopes */
 299             struct in6_addr *a6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
 300
 301             memcpy( a6->s6_addr + 2, "\x00\x00\x00\x00\x00\x00"
 302                    "\x00\x00\x00\x00\x00\x02\x7f\xfe", 14 );
 303             if( IN6_IS_ADDR_MULTICAST( a6 ) )
 304                  /* force flags to zero, preserve scope */
 305                 a6->s6_addr[1] &= 0xf;
 306             else
 307                 /* Unicast IPv6 - assume global scope */
 308                 memcpy( a6->s6_addr, "\xff\x0e", 2 );
 309
 310             b_ipv6 = VLC_TRUE;
 311             break;
 312         }
 313 #endif
 314
 315         case AF_INET:
 316         {
 317             /* See RFC2365 for IPv4 scopes */
 318             uint32_t ipv4;
 319
 320             ipv4 = ntohl( ((struct sockaddr_in *)&addr)->sin_addr.s_addr );
 321             /* 224.0.0.0/24 => 224.0.0.255 */
 322             if ((ipv4 & 0xffffff00) == 0xe0000000)
 323                 ipv4 =  0xe00000ff;
 324             else
 325             /* 239.255.0.0/16 => 239.255.255.255 */
 326             if ((ipv4 & 0xffff0000) == 0xefff0000)
 327                 ipv4 =  0xefffffff;
 328             else
 329             /* 239.192.0.0/14 => 239.195.255.255 */
 330             if ((ipv4 & 0xfffc0000) == 0xefc00000)
 331                 ipv4 =  0xefc3ffff;
 332             else
 333             /* other addresses => 224.2.127.254 */
 334                 ipv4 = 0xe0027ffe;
 335
 336             ((struct sockaddr_in *)&addr)->sin_addr.s_addr = htonl( ipv4 );
 337             break;
 338         }
 339
 340         default:
 341             vlc_mutex_unlock( &p_sap->object_lock );
 342             vlc_freeaddrinfo( res );
 343             msg_Err( p_sap, "Address family %d not supported by SAP",
 344                      addr.ss_family );
 345             return VLC_EGENERIC;
 346     }
 347
 348     i = vlc_getnameinfo( (struct sockaddr *)&addr, res->ai_addrlen,
 349                          psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );
 350     vlc_freeaddrinfo( res );
 351
 352     if( i )
 353     {
 354         vlc_mutex_unlock( &p_sap->object_lock );
 355         msg_Err( p_sap, "%s", vlc_gai_strerror( i ) );
 356         return VLC_EGENERIC;
 357     }
 358
 359     msg_Dbg( p_sap, "using SAP address: %s", psz_addr);
 360
 361     /* XXX: Check for dupes */
 362     p_sap_session = (sap_session_t*)malloc(sizeof(sap_session_t));
 363     p_sap_session->p_address = NULL;
 364
 365     /* Add the address to the buffer */
 366     for( i = 0; i < p_sap->i_addresses; i++)
 367     {
 368         if( !strcmp( psz_addr, p_sap->pp_addresses[i]->psz_address ) )
 369         {
 370             p_sap_session->p_address = p_sap->pp_addresses[i];
 371             break;
 372         }
 373     }
 374
 375     if( p_sap_session->p_address == NULL )
 376     {
 377         sap_address_t *p_address = (sap_address_t *)
 378                                     malloc( sizeof(sap_address_t) );
 379         if( !p_address )
 380         {
 381             msg_Err( p_sap, "out of memory" );
 382             return VLC_ENOMEM;
 383         }
 384         p_address->psz_address = strdup( psz_addr );
 385         p_address->i_port  =  9875;
 386         p_address->i_wfd = net_OpenUDP( p_sap, "", 0, psz_addr,
 387                                         p_address->i_port );
 388         if( p_address->i_wfd != -1 )
 389         {
 390             char *ptr;
 391
 392             net_StopRecv( p_address->i_wfd );
 393             net_GetSockAddress( p_address->i_wfd, p_address->psz_machine,
 394                                 NULL );
 395
 396             /* removes scope if present */
 397             ptr = strchr( p_address->psz_machine, '%' );
 398             if( ptr != NULL )
 399                 *ptr = '\0';
 400         }
 401
 402         if( p_sap->b_control == VLC_TRUE )
 403         {
 404             p_address->i_rfd = net_OpenUDP( p_sap, psz_addr,
 405                                             p_address->i_port, "", 0 );
 406             if( p_address->i_rfd != -1 )
 407                 net_StopSend( p_address->i_rfd );
 408             p_address->i_buff = 0;
 409             p_address->b_enabled = VLC_TRUE;
 410             p_address->b_ready = VLC_FALSE;
 411             p_address->i_limit = 10000; /* 10000 bps */
 412             p_address->t1 = 0;
 413         }
 414         else
 415         {
 416             p_address->b_enabled = VLC_TRUE;
 417             p_address->b_ready = VLC_TRUE;
 418             p_address->i_interval = config_GetInt( p_sap,"sap-interval");
 419             p_address->i_rfd = -1;
 420         }
 421
 422         if( p_address->i_wfd == -1 || (p_address->i_rfd == -1
 423                                         && p_sap->b_control ) )
 424         {
 425             msg_Warn( p_sap, "disabling address" );
 426             p_address->b_enabled = VLC_FALSE;
 427         }
 428
 429         INSERT_ELEM( p_sap->pp_addresses,
 430                      p_sap->i_addresses,
 431                      p_sap->i_addresses,
 432                      p_address );
 433         p_sap_session->p_address = p_address;
 434     }
 435
 436
 437     /* Build the SAP Headers */
 438     i_header_size = ( b_ipv6 ? 16 : 4 ) + 20;
 439     psz_head = (char *) malloc( i_header_size * sizeof( char ) );
 440     if( psz_head == NULL )
 441     {
 442         msg_Err( p_sap, "out of memory" );
 443         return VLC_ENOMEM;
 444     }
 445
 446     /* SAPv1, not encrypted, not compressed */
 447     psz_head[0] = b_ipv6 ? 0x30 : 0x20;
 448     psz_head[1] = 0x00; /* No authentification length */
 449
 450     i_hash = mdate();
 451     psz_head[2] = (i_hash & 0xFF00) >> 8; /* Msg id hash */
 452     psz_head[3] = (i_hash & 0xFF);        /* Msg id hash 2 */
 453
 454 #if defined (HAVE_INET_PTON) || defined (WIN32)
 455     if( b_ipv6 )
 456     {
 457         inet_pton( AF_INET6, /* can't fail */
 458                    p_sap_session->p_address->psz_machine,
 459                    psz_head + 4 );
 460     }
 461     else
 462 #else
 463     {
 464         inet_pton( AF_INET, /* can't fail */
 465                    p_sap_session->p_address->psz_machine,
 466                    psz_head + 4 );
 467     }
 468 #endif
 469
 470     memcpy( psz_head + (b_ipv6 ? 20 : 8), "application/sdp", 15 );
 471
 472     /* If needed, build the SDP */
 473     if( p_session->psz_sdp == NULL )
 474     {
 475         p_session->psz_sdp = SDPGenerate( p_sap, p_session,
 476                                           p_sap_session->p_address );
 477         if( p_session->psz_sdp == NULL )
 478         {
 479             vlc_mutex_unlock( &p_sap->object_lock );
 480             return VLC_ENOMEM;
 481         }
 482     }
 483
 484     p_sap_session->psz_sdp = strdup( p_session->psz_sdp );
 485     p_sap_session->i_last = 0;
 486
 487     psz_head[ i_header_size-1 ] = '\0';
 488     p_sap_session->i_length = i_header_size + strlen( p_sap_session->psz_sdp);
 489
 490     p_sap_session->psz_data = (uint8_t *)malloc( sizeof(char)*
 491                                                  p_sap_session->i_length );
 492
 493     /* Build the final message */
 494     memcpy( p_sap_session->psz_data, psz_head, i_header_size );
 495     memcpy( p_sap_session->psz_data+i_header_size, p_sap_session->psz_sdp,
 496             strlen( p_sap_session->psz_sdp) );
 497
 498     free( psz_head );
 499
 500     /* Enqueue the announce */
 501     INSERT_ELEM( p_sap->pp_sessions,
 502                  p_sap->i_sessions,
 503                  p_sap->i_sessions,
 504                  p_sap_session );
 505     msg_Dbg( p_sap,"Addresses: %i  Sessions: %i",
 506                    p_sap->i_addresses,p_sap->i_sessions);
 507
 508     /* Remember the SAP session for later deletion */
 509     p_session->p_sap = p_sap_session;
 510
 511     vlc_mutex_unlock( &p_sap->object_lock );
 512
 513     return VLC_SUCCESS;
 514 }
 515
 516 /* Remove a SAP Announce */
 517 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
 518                              session_descriptor_t *p_session )
 519 {
 520     int i;
 521     vlc_mutex_lock( &p_sap->object_lock );
 522
 523     msg_Dbg( p_sap,"removing SAP announce %p",p_session->p_sap);
 524
 525     /* Dequeue the announce */
 526     for( i = 0; i< p_sap->i_sessions; i++)
 527     {
 528         if( p_session->p_sap == p_sap->pp_sessions[i] )
 529         {
 530             REMOVE_ELEM( p_sap->pp_sessions,
 531                          p_sap->i_sessions,
 532                          i );
 533
 534             FREE( p_session->p_sap->psz_sdp );
 535             FREE( p_session->p_sap->psz_data );
 536             free( p_session->p_sap );
 537             break;
 538         }
 539     }
 540
 541     /* XXX: Dequeue the address too if it is not used anymore
 542      * TODO: - address refcount
 543              - send a SAP deletion packet */
 544
 545     msg_Dbg( p_sap,"%i announces remaining", p_sap->i_sessions );
 546
 547     vlc_mutex_unlock( &p_sap->object_lock );
 548
 549     return VLC_SUCCESS;
 550 }
 551
 552 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
 553                                      sap_session_t *p_session )
 554 {
 555     unsigned int i_ret;
 556
 557     /* This announce has never been sent yet */
 558     if( p_session->i_last == 0 )
 559     {
 560         p_session->i_next = mdate()+ p_session->p_address->i_interval*1000000;
 561         p_session->i_last = 1;
 562         return VLC_SUCCESS;
 563     }
 564
 565     if( p_session->i_next < mdate() )
 566     {
 567 #ifdef EXTRA_DEBUG
 568         msg_Dbg( p_sap, "Sending announce");
 569 #endif
 570         i_ret = net_Write( p_sap, p_session->p_address->i_wfd, NULL,
 571                            p_session->psz_data,
 572                            p_session->i_length );
 573         if( i_ret != (int)p_session->i_length )
 574         {
 575             msg_Warn( p_sap, "SAP send failed on address %s (%i %i)",
 576                    p_session->p_address->psz_address,
 577                    i_ret, p_session->i_length );
 578         }
 579         p_session->i_last = p_session->i_next;
 580         p_session->i_next = p_session->i_last
 581                             + p_session->p_address->i_interval*1000000;
 582     }
 583     else
 584     {
 585         return VLC_SUCCESS;
 586     }
 587     return VLC_SUCCESS;
 588 }
 589
 590 static char *SDPGenerate( sap_handler_t *p_sap,
 591                           const session_descriptor_t *p_session,
 592                           const sap_address_t *p_addr )
 593 {
 594     int64_t i_sdp_id = mdate();
 595     int     i_sdp_version = 1 + p_sap->i_sessions + (rand()&0xfff);
 596     char *psz_group, *psz_name, psz_uribuf[NI_MAXNUMERICHOST], *psz_uri,
 597          *psz_sdp;
 598     char ipv;
 599
 600     psz_group = p_session->psz_group;
 601     psz_name = p_session->psz_name;
 602
 603     /* FIXME: really check that psz_uri is a real IP address
 604      * FIXME: make a common function to obtain a canonical IP address */
 605     ipv = ( strchr( p_session->psz_uri, ':' )  != NULL) ? '6' : '4';
 606     if( *p_session->psz_uri == '[' )
 607     {
 608         char *ptr;
 609
 610         strncpy( psz_uribuf, p_session->psz_uri + 1, sizeof( psz_uribuf ) );
 611         psz_uribuf[sizeof( psz_uribuf ) - 1] = '\0';
 612         ptr = strchr( psz_uribuf, '%' );
 613         if( ptr != NULL)
 614             *ptr = '\0';
 615         ptr = strchr( psz_uribuf, ']' );
 616         if( ptr != NULL)
 617             *ptr = '\0';
 618         psz_uri = psz_uribuf;
 619     }
 620     else
 621         psz_uri = p_session->psz_uri;
 622
 623     /* see the lists in modules/stream_out/rtp.c for compliance stuff */
 624     if( asprintf( &psz_sdp,
 625                             "v=0\r\n"
 626                             "o=- "I64Fd" %d IN IP%c %s\r\n"
 627                             "s=%s\r\n"
 628                             "t=0 0\r\n"
 629                             "c=IN IP%c %s/%d\r\n"
 630                             "m=video %d udp %d\r\n"
 631                             "a=tool:"PACKAGE_STRING"\r\n"
 632                             "a=type:broadcast\r\n"
 633                             "%s%s%s",
 634                             i_sdp_id, i_sdp_version,
 635                             ipv, p_addr->psz_machine,
 636                             psz_name, ipv,
 637                             psz_uri, p_session->i_ttl,
 638                             p_session->i_port, p_session->i_payload,
 639                             psz_group ? "a=x-plgroup:" : "",
 640                             psz_group ? psz_group : "", psz_group ? "\r\n" : "" ) == -1 )
 641         return NULL;
 642
 643     msg_Dbg( p_sap, "Generated SDP (%i bytes):\n%s", strlen(psz_sdp),
 644              psz_sdp );
 645     return psz_sdp;
 646 }
 647
 648 static int CalculateRate( sap_handler_t *p_sap, sap_address_t *p_address )
 649 {
 650     int i_read;
 651     uint8_t buffer[SAP_MAX_BUFFER];
 652     int i_tot = 0;
 653     mtime_t i_temp;
 654     int i_rate;
 655
 656     if( p_address->t1 == 0 )
 657     {
 658         p_address->t1 = mdate();
 659         return VLC_SUCCESS;
 660     }
 661     do
 662     {
 663         /* Might be too slow if we have huge data */
 664         i_read = net_ReadNonBlock( p_sap, p_address->i_rfd, NULL, buffer,
 665                                    SAP_MAX_BUFFER, 0 );
 666         i_tot += i_read;
 667     } while( i_read > 0 && i_tot < SAP_MAX_BUFFER );
 668
 669     i_temp = mdate();
 670
 671     /* We calculate the rate every 5 seconds */
 672     if( i_temp - p_address->t1 < 5000000 )
 673     {
 674         p_address->i_buff += i_tot;
 675         return VLC_SUCCESS;
 676     }
 677
 678     /* Bits/second */
 679     i_rate = (int)(8*1000000*((mtime_t)p_address->i_buff + (mtime_t)i_tot ) /
 680                         (i_temp - p_address->t1 ));
 681
 682     p_address->i_limit = 10000;
 683
 684     p_address->i_interval = ((1000*i_rate / p_address->i_limit) *
 685                             (MAX_INTERVAL - MIN_INTERVAL))/1000 + MIN_INTERVAL;
 686
 687     if( p_address->i_interval > MAX_INTERVAL || p_address->i_interval < 0 )
 688     {
 689         p_address->i_interval = MAX_INTERVAL;
 690     }
 691 #ifdef EXTRA_DEBUG
 692     msg_Dbg( p_sap,"%s:%i : Rate=%i, Interval = %i s",
 693                     p_address->psz_address,p_address->i_port,
 694                     i_rate,
 695                     p_address->i_interval );
 696 #endif
 697
 698     p_address->b_ready = VLC_TRUE;
 699
 700     p_address->t1 = i_temp;
 701     p_address->i_buff = 0;
 702
 703     return VLC_SUCCESS;
 704 }