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