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