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
  29 #include <vlc/vlc.h>
  30
  31 #include <stdlib.h>                                                /* free() */
  32 #include <stdio.h>                                              /* sprintf() */
  33 #include <string.h>                                            /* strerror() */
  34 #include <ctype.h>                                  /* tolower(), isxdigit() */
  35
  36 #include <vlc_sout.h>
  37 #include <vlc_network.h>
  38 #include <vlc_charset.h>
  39
  40 #include "stream_output.h"
  41
  42 /* SAP is always on that port */
  43 #define SAP_PORT 9875
  44
  45 #define DEFAULT_PORT "1234"
  46
  47 #undef EXTRA_DEBUG
  48
  49 /* SAP Specific structures */
  50
  51 /* 100ms */
  52 #define SAP_IDLE ((mtime_t)(0.100*CLOCK_FREQ))
  53 #define SAP_MAX_BUFFER 65534
  54 #define MIN_INTERVAL 2
  55 #define MAX_INTERVAL 300
  56
  57 /* A SAP announce address. For each of these, we run the
  58  * control flow algorithm */
  59 struct sap_address_t
  60 {
  61     char *psz_address;
  62     struct sockaddr_storage orig;
  63     socklen_t origlen;
  64     int i_rfd; /* Read socket */
  65     int i_wfd; /* Write socket */
  66
  67     /* Used for flow control */
  68     mtime_t t1;
  69     vlc_bool_t b_enabled;
  70     vlc_bool_t b_ready;
  71     int i_interval;
  72     int i_buff;
  73     int i_limit;
  74 };
  75
  76 /* A SAP session descriptor, enqueued in the SAP handler queue */
  77 struct sap_session_t {
  78     uint8_t       *psz_data;
  79     unsigned      i_length;
  80     sap_address_t *p_address;
  81     session_descriptor_t *p_sd;
  82
  83     /* Last and next send */
  84     mtime_t        i_last;
  85     mtime_t        i_next;
  86 };
  87
  88 /*****************************************************************************
  89  * Local prototypes
  90  *****************************************************************************/
  91 static void RunThread( vlc_object_t *p_this);
  92 static int CalculateRate( sap_handler_t *p_sap, sap_address_t *p_address );
  93 static char *SDPGenerate( sap_handler_t *p_sap,
  94                           const session_descriptor_t *p_session,
  95                           const sap_address_t *p_addr, vlc_bool_t b_ssm );
  96
  97 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
  98                                      sap_session_t *p_session );
  99
 100
 101 static int announce_SAPAnnounceAdd( sap_handler_t *p_sap,
 102                              session_descriptor_t *p_session );
 103
 104 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
 105                              session_descriptor_t *p_session );
 106
 107
 108 /**
 109  * Create the SAP handler
 110  *
 111  * \param p_announce the parent announce_handler
 112  * \return the newly created SAP handler or NULL on error
 113  */
 114 sap_handler_t *announce_SAPHandlerCreate( announce_handler_t *p_announce )
 115 {
 116     sap_handler_t *p_sap;
 117
 118     p_sap = vlc_object_create( p_announce, sizeof( sap_handler_t ) );
 119
 120     if( !p_sap )
 121     {
 122         msg_Err( p_announce, "out of memory" );
 123         return NULL;
 124     }
 125
 126     vlc_mutex_init( p_sap, &p_sap->object_lock );
 127
 128     p_sap->pf_add = announce_SAPAnnounceAdd;
 129     p_sap->pf_del = announce_SAPAnnounceDel;
 130
 131     p_sap->i_sessions = 0;
 132     p_sap->i_addresses = 0;
 133     p_sap->i_current_session = 0;
 134
 135     p_sap->b_control = config_GetInt( p_sap, "sap-flow-control");
 136
 137     if( vlc_thread_create( p_sap, "sap handler", RunThread,
 138                        VLC_THREAD_PRIORITY_LOW, VLC_FALSE ) )
 139     {
 140         msg_Dbg( p_announce, "unable to spawn SAP handler thread");
 141         free( p_sap );
 142         return NULL;
 143     };
 144     msg_Dbg( p_announce, "thread created, %i sessions", p_sap->i_sessions);
 145     return p_sap;
 146 }
 147
 148 /**
 149  *  Destroy the SAP handler
 150  *  \param p_this the SAP Handler to destroy
 151  *  \return nothing
 152  */
 153 void announce_SAPHandlerDestroy( sap_handler_t *p_sap )
 154 {
 155     int i;
 156
 157     vlc_mutex_destroy( &p_sap->object_lock );
 158
 159     /* Free the remaining sessions */
 160     for( i = 0 ; i< p_sap->i_sessions ; i++)
 161     {
 162         sap_session_t *p_session = p_sap->pp_sessions[i];
 163         FREENULL( p_session->psz_data );
 164         REMOVE_ELEM( p_sap->pp_sessions, p_sap->i_sessions , i );
 165         FREENULL( 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         FREENULL( 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         FREENULL( 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;
 250     char psz_addr[NI_MAXNUMERICHOST];
 251     vlc_bool_t b_ipv6 = VLC_FALSE, b_ssm = VLC_FALSE;
 252     sap_session_t *p_sap_session;
 253     mtime_t i_hash;
 254     struct sockaddr_storage addr;
 255     socklen_t addrlen;
 256
 257     vlc_mutex_lock( &p_sap->object_lock );
 258     addrlen = p_session->addrlen;
 259     if ((addrlen == 0) || (addrlen > sizeof (addr)))
 260     {
 261         vlc_mutex_unlock( &p_sap->object_lock );
 262         msg_Err( p_sap, "No/invalid address specified for SAP announce" );
 263         return VLC_EGENERIC;
 264     }
 265
 266     /* Determine SAP multicast address automatically */
 267     memcpy (&addr, &p_session->addr, addrlen);
 268
 269     switch( p_session->addr.ss_family )
 270     {
 271 #if defined (HAVE_INET_PTON) || defined (WIN32)
 272         case AF_INET6:
 273         {
 274             /* See RFC3513 for list of valid IPv6 scopes */
 275             struct in6_addr *a6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
 276
 277             memcpy( a6->s6_addr + 2, "\x00\x00\x00\x00\x00\x00"
 278                    "\x00\x00\x00\x00\x00\x02\x7f\xfe", 14 );
 279             if( IN6_IS_ADDR_MULTICAST( a6 ) )
 280             {
 281                 /* SSM <=> ff3x::/32 */
 282                 b_ssm = (U32_AT (a6->s6_addr) & 0xfff0ffff) == 0xff300000;
 283
 284                 /* force flags to zero, preserve scope */
 285                 a6->s6_addr[1] &= 0xf;
 286             }
 287             else
 288                 /* Unicast IPv6 - assume global scope */
 289                 memcpy( a6->s6_addr, "\xff\x0e", 2 );
 290
 291             b_ipv6 = VLC_TRUE;
 292             break;
 293         }
 294 #endif
 295
 296         case AF_INET:
 297         {
 298             /* See RFC2365 for IPv4 scopes */
 299             uint32_t ipv4;
 300
 301             ipv4 = ntohl( ((struct sockaddr_in *)&addr)->sin_addr.s_addr );
 302             /* 224.0.0.0/24 => 224.0.0.255 */
 303             if ((ipv4 & 0xffffff00) == 0xe0000000)
 304                 ipv4 =  0xe00000ff;
 305             else
 306             /* 239.255.0.0/16 => 239.255.255.255 */
 307             if ((ipv4 & 0xffff0000) == 0xefff0000)
 308                 ipv4 =  0xefffffff;
 309             else
 310             /* 239.192.0.0/14 => 239.195.255.255 */
 311             if ((ipv4 & 0xfffc0000) == 0xefc00000)
 312                 ipv4 =  0xefc3ffff;
 313             else
 314             if ((ipv4 & 0xff000000) == 0xef000000)
 315                 ipv4 = 0;
 316             else
 317             /* other addresses => 224.2.127.254 */
 318             {
 319                 /* SSM: 232.0.0.0/8 */
 320                 b_ssm = (ipv4 >> 24) == 232;
 321                 ipv4 = 0xe0027ffe;
 322             }
 323
 324             /* FIXME FIXME FIXME */
 325             if( ipv4 == 0 )
 326             {
 327                 msg_Err( p_sap, "Out-of-scope multicast address "
 328                          "not supported by SAP" );
 329                 vlc_mutex_unlock( &p_sap->object_lock );
 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             msg_Err( p_sap, "Address family %d not supported by SAP",
 340                      addr.ss_family );
 341             return VLC_EGENERIC;
 342     }
 343
 344     i = vlc_getnameinfo( (struct sockaddr *)&addr, addrlen,
 345                          psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );
 346
 347     if( i )
 348     {
 349         vlc_mutex_unlock( &p_sap->object_lock );
 350         msg_Err( p_sap, "%s", vlc_gai_strerror( i ) );
 351         return VLC_EGENERIC;
 352     }
 353
 354     msg_Dbg( p_sap, "using SAP address: %s", psz_addr);
 355
 356     /* XXX: Check for dupes */
 357     p_sap_session = (sap_session_t*)malloc(sizeof(sap_session_t));
 358     p_sap_session->p_sd = p_session;
 359     p_sap_session->p_address = NULL;
 360
 361     /* Add the address to the buffer */
 362     for( i = 0; i < p_sap->i_addresses; i++)
 363     {
 364         if( !strcmp( psz_addr, p_sap->pp_addresses[i]->psz_address ) )
 365         {
 366             p_sap_session->p_address = p_sap->pp_addresses[i];
 367             break;
 368         }
 369     }
 370
 371     if( p_sap_session->p_address == NULL )
 372     {
 373         sap_address_t *p_address = (sap_address_t *)
 374                                     malloc( sizeof(sap_address_t) );
 375         if( !p_address )
 376         {
 377             vlc_mutex_unlock( &p_sap->object_lock );
 378             return VLC_ENOMEM;
 379         }
 380         p_address->psz_address = strdup( psz_addr );
 381         p_address->i_wfd = net_ConnectUDP( VLC_OBJECT(p_sap), psz_addr, SAP_PORT, 255 );
 382         if( p_address->i_wfd != -1 )
 383         {
 384             net_StopRecv( p_address->i_wfd );
 385             p_address->origlen = sizeof (p_address->orig);
 386             getsockname (p_address->i_wfd, (struct sockaddr *)&p_address->orig,
 387                          &p_address->origlen);
 388         }
 389
 390         if( p_sap->b_control == VLC_TRUE )
 391         {
 392             p_address->i_rfd = net_ListenUDP1( (vlc_object_t*)p_sap, psz_addr, SAP_PORT );
 393             if( p_address->i_rfd != -1 )
 394                 net_StopSend( p_address->i_rfd );
 395             p_address->i_buff = 0;
 396             p_address->b_enabled = VLC_TRUE;
 397             p_address->b_ready = VLC_FALSE;
 398             p_address->i_limit = 10000; /* 10000 bps */
 399             p_address->t1 = 0;
 400         }
 401         else
 402         {
 403             p_address->b_enabled = VLC_TRUE;
 404             p_address->b_ready = VLC_TRUE;
 405             p_address->i_interval = config_GetInt( p_sap,"sap-interval");
 406             p_address->i_rfd = -1;
 407         }
 408
 409         if( p_address->i_wfd == -1 || (p_address->i_rfd == -1
 410                                         && p_sap->b_control ) )
 411         {
 412             msg_Warn( p_sap, "disabling address" );
 413             p_address->b_enabled = VLC_FALSE;
 414         }
 415
 416         INSERT_ELEM( p_sap->pp_addresses,
 417                      p_sap->i_addresses,
 418                      p_sap->i_addresses,
 419                      p_address );
 420         p_sap_session->p_address = p_address;
 421     }
 422
 423     if (p_session->origlen == 0)
 424         memcpy (&p_session->orig, &p_sap_session->p_address->orig,
 425                 p_session->origlen = p_sap_session->p_address->origlen);
 426
 427     size_t headsize = 20;
 428     switch (p_session->orig.ss_family)
 429     {
 430 #ifdef AF_INET6
 431         case AF_INET6:
 432             headsize += 16;
 433             break;
 434 #endif
 435         case AF_INET:
 436             headsize =+ 4;
 437             break;
 438         default:
 439             msg_Err( p_sap, "Address family %d not supported by SAP",
 440                      addr.ss_family );
 441             vlc_mutex_unlock( &p_sap->object_lock );
 442             return VLC_EGENERIC;
 443     }
 444
 445     /* If needed, build the SDP */
 446     if( p_session->psz_sdp == NULL )
 447     {
 448         p_session->psz_sdp = SDPGenerate( p_sap, p_session,
 449                                           p_sap_session->p_address, b_ssm );
 450         if( p_session->psz_sdp == NULL )
 451         {
 452             vlc_mutex_unlock( &p_sap->object_lock );
 453             return VLC_ENOMEM;
 454         }
 455     }
 456
 457     p_sap_session->i_last = 0;
 458     p_sap_session->i_length = headsize + strlen (p_session->psz_sdp);
 459     p_sap_session->psz_data = malloc (p_sap_session->i_length + 1);
 460     if (p_sap_session->psz_data == NULL)
 461     {
 462         free (p_session->psz_sdp);
 463         vlc_mutex_unlock( &p_sap->object_lock );
 464         return VLC_ENOMEM;
 465     }
 466
 467     /* Build the SAP Headers */
 468     uint8_t *psz_head = p_sap_session->psz_data;
 469
 470     /* SAPv1, not encrypted, not compressed */
 471     psz_head[0] = 0x20;
 472     psz_head[1] = 0x00; /* No authentification length */
 473
 474     i_hash = mdate();
 475     psz_head[2] = i_hash >> 8; /* Msg id hash */
 476     psz_head[3] = i_hash;      /* Msg id hash 2 */
 477
 478     headsize = 4;
 479     switch (p_session->orig.ss_family)
 480     {
 481 #ifdef AF_INET6
 482         case AF_INET6:
 483         {
 484             struct in6_addr *a6 =
 485                 &((struct sockaddr_in6 *)&p_session->orig)->sin6_addr;
 486             memcpy (psz_head + headsize, a6, 16);
 487             psz_head[0] |= 0x10; /* IPv6 flag */
 488             headsize += 16;
 489             break;
 490         }
 491 #endif
 492         case AF_INET:
 493         {
 494             uint32_t ipv4 =
 495                 (((struct sockaddr_in *)&p_session->orig)->sin_addr.s_addr);
 496             memcpy (psz_head + headsize, &ipv4, 4);
 497             headsize += 4;
 498             break;
 499         }
 500
 501     }
 502
 503     memcpy (psz_head + headsize, "application/sdp", 16);
 504     headsize += 16;
 505
 506     /* Build the final message */
 507     strcpy( (char *)psz_head + headsize, p_session->psz_sdp);
 508
 509     /* Enqueue the announce */
 510     INSERT_ELEM( p_sap->pp_sessions,
 511                  p_sap->i_sessions,
 512                  p_sap->i_sessions,
 513                  p_sap_session );
 514     msg_Dbg( p_sap,"%i addresses, %i sessions",
 515                    p_sap->i_addresses,p_sap->i_sessions);
 516
 517     vlc_mutex_unlock( &p_sap->object_lock );
 518
 519     return VLC_SUCCESS;
 520 }
 521
 522 /* Remove a SAP Announce */
 523 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
 524                              session_descriptor_t *p_session )
 525 {
 526     int i;
 527     vlc_mutex_lock( &p_sap->object_lock );
 528
 529     msg_Dbg( p_sap, "removing session %p from SAP", p_session);
 530
 531     /* Dequeue the announce */
 532     for( i = 0; i< p_sap->i_sessions; i++)
 533     {
 534         if( p_session == p_sap->pp_sessions[i]->p_sd )
 535         {
 536             sap_session_t *p_mysession = p_sap->pp_sessions[i];
 537             REMOVE_ELEM( p_sap->pp_sessions,
 538                          p_sap->i_sessions,
 539                          i );
 540
 541             free( p_mysession->psz_data );
 542             free( p_mysession );
 543             break;
 544         }
 545     }
 546
 547     /* XXX: Dequeue the address too if it is not used anymore
 548      * TODO: - address refcount
 549              - send a SAP deletion packet */
 550
 551     msg_Dbg( p_sap,"%i announcements remaining", p_sap->i_sessions );
 552
 553     vlc_mutex_unlock( &p_sap->object_lock );
 554
 555     return VLC_SUCCESS;
 556 }
 557
 558 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
 559                                      sap_session_t *p_session )
 560 {
 561     int i_ret;
 562
 563     /* This announce has never been sent yet */
 564     if( p_session->i_last == 0 )
 565     {
 566         p_session->i_next = mdate()+ p_session->p_address->i_interval*1000000;
 567         p_session->i_last = 1;
 568         return VLC_SUCCESS;
 569     }
 570
 571     if( p_session->i_next < mdate() )
 572     {
 573 #ifdef EXTRA_DEBUG
 574         msg_Dbg( p_sap, "sending announce");
 575 #endif
 576         i_ret = net_Write( p_sap, p_session->p_address->i_wfd, NULL,
 577                            p_session->psz_data,
 578                            p_session->i_length );
 579         if( i_ret != (int)p_session->i_length )
 580         {
 581             msg_Warn( p_sap, "SAP send failed on address %s (%i %i)",
 582                       p_session->p_address->psz_address,
 583                       i_ret, p_session->i_length );
 584         }
 585         p_session->i_last = p_session->i_next;
 586         p_session->i_next = p_session->i_last
 587                             + p_session->p_address->i_interval*1000000;
 588     }
 589     else
 590     {
 591         return VLC_SUCCESS;
 592     }
 593     return VLC_SUCCESS;
 594 }
 595
 596 static char *SDPGenerate( sap_handler_t *p_sap,
 597                           const session_descriptor_t *p_session,
 598                           const sap_address_t *p_addr, vlc_bool_t b_ssm )
 599 {
 600     char *psz_group, *psz_name, *psz_sdp;
 601
 602      char *head = StartSDP (p_session->psz_name, p_session->description,
 603         p_session->url, p_session->email, p_session->phone,
 604         (const struct sockaddr *)&p_session->orig, p_session->origlen,
 605         (const struct sockaddr *)&p_session->addr, p_session->addrlen);
 606     if (head == NULL)
 607         return NULL;
 608
 609     psz_group = p_session->psz_group;
 610     psz_name = p_session->psz_name;
 611
 612     char *plgroup;
 613     if ((psz_group == NULL)
 614      || (asprintf (&plgroup, "a=x-plgroup:%s\r\n", psz_group) == -1))
 615         plgroup = NULL;
 616
 617     char *sfilter;
 618 #if 0
 619     if ((!b_ssm)
 620      || (asprintf (&sfilter, "a=source-filter: incl IN IP%c * %s\r\n",
 621                    ipv, p_addr->psz_machine) == -1))
 622 #else
 623 # warning FIXME: repair Source Specific Multicast
 624 #endif
 625         sfilter = NULL;
 626
 627     int res = asprintf (&psz_sdp, "%s" "%s" "%s"
 628                         "m=video %d %s\r\n",
 629                         head,
 630                         plgroup ?: "",
 631                         sfilter ?: "",
 632                         net_GetPort ((const struct sockaddr *)&p_session->addr),
 633                         p_session->sdpformat);
 634     free (plgroup);
 635     free (sfilter);
 636
 637     if (res == -1)
 638         return NULL;
 639
 640     msg_Dbg( p_sap, "Generated SDP (%i bytes):\n%s", strlen(psz_sdp),
 641              psz_sdp );
 642     return psz_sdp;
 643 }
 644
 645 static int CalculateRate( sap_handler_t *p_sap, sap_address_t *p_address )
 646 {
 647     int i_read;
 648     uint8_t buffer[SAP_MAX_BUFFER];
 649     int i_tot = 0;
 650     mtime_t i_temp;
 651     int i_rate;
 652
 653     if( p_address->t1 == 0 )
 654     {
 655         p_address->t1 = mdate();
 656         return VLC_SUCCESS;
 657     }
 658     do
 659     {
 660         /* Might be too slow if we have huge data */
 661         i_read = net_ReadNonBlock( p_sap, p_address->i_rfd, NULL, buffer,
 662                                    SAP_MAX_BUFFER, 0 );
 663         i_tot += i_read;
 664     } while( i_read > 0 );
 665
 666     i_temp = mdate();
 667
 668     /* We calculate the rate every 5 seconds */
 669     if( i_temp - p_address->t1 < 5000000 )
 670     {
 671         p_address->i_buff += i_tot;
 672         return VLC_SUCCESS;
 673     }
 674
 675     /* Bits/second */
 676     i_rate = (int)(8*1000000*((mtime_t)p_address->i_buff + (mtime_t)i_tot ) /
 677                         (i_temp - p_address->t1 ));
 678
 679     p_address->i_limit = 10000;
 680
 681     p_address->i_interval = ((1000*i_rate / p_address->i_limit) *
 682                             (MAX_INTERVAL - MIN_INTERVAL))/1000 + MIN_INTERVAL;
 683
 684     if( p_address->i_interval > MAX_INTERVAL || p_address->i_interval < 0 )
 685     {
 686         p_address->i_interval = MAX_INTERVAL;
 687     }
 688 #ifdef EXTRA_DEBUG
 689     msg_Dbg( p_sap,"%s:%i: rate=%i, interval = %i s",
 690              p_address->psz_address,SAP_PORT, i_rate, p_address->i_interval );
 691 #endif
 692
 693     p_address->b_ready = VLC_TRUE;
 694
 695     p_address->t1 = i_temp;
 696     p_address->i_buff = 0;
 697
 698     return VLC_SUCCESS;
 699 }