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

   1 /*****************************************************************************
   2  * sap.c : SAP announce handler
   3  *****************************************************************************
   4  * Copyright (C) 2002-2007 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 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc_common.h>
  34
  35 #include <stdlib.h>                                                /* free() */
  36 #include <stdio.h>                                              /* sprintf() */
  37 #include <string.h>
  38 #include <ctype.h>                                  /* tolower(), isxdigit() */
  39 #include <assert.h>
  40
  41 #include <vlc_sout.h>
  42 #include <vlc_network.h>
  43 #include <vlc_charset.h>
  44
  45 #include "stream_output.h"
  46 #include "libvlc.h"
  47
  48 /* SAP is always on that port */
  49 #define SAP_PORT 9875
  50
  51 #define DEFAULT_PORT "1234"
  52
  53 #undef EXTRA_DEBUG
  54
  55 /* SAP Specific structures */
  56
  57 /* 100ms */
  58 #define SAP_IDLE ((mtime_t)(0.100*CLOCK_FREQ))
  59 #define SAP_MAX_BUFFER 65534
  60 #define MIN_INTERVAL 2
  61 #define MAX_INTERVAL 300
  62
  63 /* A SAP announce address. For each of these, we run the
  64  * control flow algorithm */
  65 struct sap_address_t
  66 {
  67     char *psz_address;
  68     struct sockaddr_storage orig;
  69     socklen_t origlen;
  70     int i_rfd; /* Read socket */
  71     int i_wfd; /* Write socket */
  72
  73     /* Used for flow control */
  74     mtime_t t1;
  75     bool b_enabled;
  76     bool b_ready;
  77     int i_interval;
  78     int i_buff;
  79     int i_limit;
  80 };
  81
  82 /* A SAP session descriptor, enqueued in the SAP handler queue */
  83 struct sap_session_t {
  84     uint8_t       *psz_data;
  85     unsigned      i_length;
  86     sap_address_t *p_address;
  87     session_descriptor_t *p_sd;
  88
  89     /* Last and next send */
  90     mtime_t        i_last;
  91     mtime_t        i_next;
  92 };
  93
  94 /*****************************************************************************
  95  * Local prototypes
  96  *****************************************************************************/
  97 static void * RunThread( vlc_object_t *p_this);
  98 static int ComputeRate( sap_address_t *p_address );
  99
 100 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
 101                                      sap_session_t *p_session );
 102
 103
 104 static int announce_SAPAnnounceAdd( sap_handler_t *p_sap,
 105                              session_descriptor_t *p_session );
 106
 107 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
 108                              session_descriptor_t *p_session );
 109
 110 static void announce_SAPHandlerDestructor( vlc_object_t *p_this );
 111
 112
 113 /**
 114  * Create the SAP handler
 115  *
 116  * \param p_announce the parent announce_handler
 117  * \return the newly created SAP handler or NULL on error
 118  */
 119 sap_handler_t *announce_SAPHandlerCreate( announce_handler_t *p_announce )
 120 {
 121     sap_handler_t *p_sap;
 122
 123     p_sap = vlc_custom_create( VLC_OBJECT(p_announce), sizeof( sap_handler_t ),
 124                                VLC_OBJECT_ANNOUNCE, "announce" );
 125     if( !p_sap )
 126         return NULL;
 127
 128     p_sap->psz_object_name = strdup( "sap announcer" );
 129
 130     p_sap->pf_add = announce_SAPAnnounceAdd;
 131     p_sap->pf_del = announce_SAPAnnounceDel;
 132
 133     p_sap->i_sessions = 0;
 134     p_sap->i_addresses = 0;
 135     p_sap->i_current_session = 0;
 136
 137     p_sap->b_control = config_GetInt( p_sap, "sap-flow-control");
 138
 139     if( vlc_thread_create( p_sap, "sap handler", RunThread,
 140                        VLC_THREAD_PRIORITY_LOW, false ) )
 141     {
 142         msg_Dbg( p_announce, "unable to spawn SAP handler thread");
 143         vlc_object_release( p_sap );
 144         return NULL;
 145     }
 146
 147     vlc_object_set_destructor( p_sap, announce_SAPHandlerDestructor );
 148
 149     msg_Dbg( p_announce, "thread created, %i sessions", p_sap->i_sessions);
 150
 151     return p_sap;
 152 }
 153
 154 static void announce_SAPHandlerDestructor( vlc_object_t * p_this )
 155 {
 156     sap_handler_t *p_sap = (sap_handler_t *)p_this;
 157     int i;
 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
 186 /**
 187  * main SAP handler thread
 188  * \param p_this the SAP Handler object
 189  * \return nothing
 190  */
 191 static void * RunThread( vlc_object_t *p_this)
 192 {
 193     sap_handler_t *p_sap = (sap_handler_t*)p_this;
 194     sap_session_t *p_session;
 195
 196     while( !p_sap->b_die )
 197     {
 198         int i;
 199
 200         msleep( SAP_IDLE );
 201
 202         /* If needed, get the rate info */
 203         if( p_sap->b_control == true )
 204         {
 205             for( i = 0 ; i< p_sap->i_addresses ; i++)
 206             {
 207                 if( p_sap->pp_addresses[i]->b_enabled == true )
 208                 {
 209                     ComputeRate( p_sap->pp_addresses[i] );
 210                 }
 211             }
 212         }
 213
 214         /* Find the session to announce */
 215         vlc_object_lock( p_sap );
 216         if( p_sap->i_sessions > p_sap->i_current_session + 1)
 217         {
 218             p_sap->i_current_session++;
 219         }
 220         else if( p_sap->i_sessions > 0)
 221         {
 222             p_sap->i_current_session = 0;
 223         }
 224         else
 225         {
 226             vlc_object_unlock( p_sap );
 227             continue;
 228         }
 229         p_session = p_sap->pp_sessions[p_sap->i_current_session];
 230
 231         /* And announce it */
 232         if( p_session->p_address->b_enabled == true &&
 233             p_session->p_address->b_ready == true )
 234         {
 235             announce_SendSAPAnnounce( p_sap, p_session );
 236         }
 237         vlc_object_unlock( p_sap );
 238     }
 239     return NULL;
 240 }
 241
 242 /* Add a SAP announce */
 243 static int announce_SAPAnnounceAdd( sap_handler_t *p_sap,
 244                              session_descriptor_t *p_session )
 245 {
 246     int i;
 247     char psz_addr[NI_MAXNUMERICHOST];
 248     bool b_ipv6 = false, b_ssm = false;
 249     sap_session_t *p_sap_session;
 250     mtime_t i_hash;
 251     struct sockaddr_storage addr;
 252     socklen_t addrlen;
 253
 254     vlc_object_lock( p_sap );
 255     addrlen = p_session->addrlen;
 256     if ((addrlen == 0) || (addrlen > sizeof (addr)))
 257     {
 258         vlc_object_unlock( p_sap );
 259         msg_Err( p_sap, "No/invalid address specified for SAP announce" );
 260         return VLC_EGENERIC;
 261     }
 262
 263     /* Determine SAP multicast address automatically */
 264     memcpy (&addr, &p_session->addr, addrlen);
 265
 266     switch( p_session->addr.ss_family )
 267     {
 268 #if defined (HAVE_INET_PTON) || defined (WIN32)
 269         case AF_INET6:
 270         {
 271             /* See RFC3513 for list of valid IPv6 scopes */
 272             struct in6_addr *a6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
 273
 274             memcpy( a6->s6_addr + 2, "\x00\x00\x00\x00\x00\x00"
 275                    "\x00\x00\x00\x00\x00\x02\x7f\xfe", 14 );
 276             if( IN6_IS_ADDR_MULTICAST( a6 ) )
 277             {
 278                 /* SSM <=> ff3x::/32 */
 279                 b_ssm = (U32_AT (a6->s6_addr) & 0xfff0ffff) == 0xff300000;
 280
 281                 /* force flags to zero, preserve scope */
 282                 a6->s6_addr[1] &= 0xf;
 283             }
 284             else
 285                 /* Unicast IPv6 - assume global scope */
 286                 memcpy( a6->s6_addr, "\xff\x0e", 2 );
 287
 288             b_ipv6 = true;
 289             break;
 290         }
 291 #endif
 292
 293         case AF_INET:
 294         {
 295             /* See RFC2365 for IPv4 scopes */
 296             uint32_t ipv4;
 297
 298             ipv4 = ntohl( ((struct sockaddr_in *)&addr)->sin_addr.s_addr );
 299             /* 224.0.0.0/24 => 224.0.0.255 */
 300             if ((ipv4 & 0xffffff00) == 0xe0000000)
 301                 ipv4 =  0xe00000ff;
 302             else
 303             /* 239.255.0.0/16 => 239.255.255.255 */
 304             if ((ipv4 & 0xffff0000) == 0xefff0000)
 305                 ipv4 =  0xefffffff;
 306             else
 307             /* 239.192.0.0/14 => 239.195.255.255 */
 308             if ((ipv4 & 0xfffc0000) == 0xefc00000)
 309                 ipv4 =  0xefc3ffff;
 310             else
 311             if ((ipv4 & 0xff000000) == 0xef000000)
 312                 ipv4 = 0;
 313             else
 314             /* other addresses => 224.2.127.254 */
 315             {
 316                 /* SSM: 232.0.0.0/8 */
 317                 b_ssm = (ipv4 >> 24) == 232;
 318                 ipv4 = 0xe0027ffe;
 319             }
 320
 321             if( ipv4 == 0 )
 322             {
 323                 msg_Err( p_sap, "Out-of-scope multicast address "
 324                          "not supported by SAP" );
 325                 vlc_object_unlock( p_sap );
 326                 return VLC_EGENERIC;
 327             }
 328
 329             ((struct sockaddr_in *)&addr)->sin_addr.s_addr = htonl( ipv4 );
 330             break;
 331         }
 332
 333         default:
 334             vlc_object_unlock( p_sap );
 335             msg_Err( p_sap, "Address family %d not supported by SAP",
 336                      addr.ss_family );
 337             return VLC_EGENERIC;
 338     }
 339
 340     i = vlc_getnameinfo( (struct sockaddr *)&addr, addrlen,
 341                          psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );
 342
 343     if( i )
 344     {
 345         vlc_object_unlock( p_sap );
 346         msg_Err( p_sap, "%s", vlc_gai_strerror( i ) );
 347         return VLC_EGENERIC;
 348     }
 349
 350     msg_Dbg( p_sap, "using SAP address: %s", psz_addr);
 351
 352     /* XXX: Check for dupes */
 353     p_sap_session = (sap_session_t*)malloc(sizeof(sap_session_t));
 354     p_sap_session->p_sd = p_session;
 355     p_sap_session->p_address = NULL;
 356
 357     /* Add the address to the buffer */
 358     for( i = 0; i < p_sap->i_addresses; i++)
 359     {
 360         if( !strcmp( psz_addr, p_sap->pp_addresses[i]->psz_address ) )
 361         {
 362             p_sap_session->p_address = p_sap->pp_addresses[i];
 363             break;
 364         }
 365     }
 366
 367     if( p_sap_session->p_address == NULL )
 368     {
 369         sap_address_t *p_address = (sap_address_t *)
 370                                     malloc( sizeof(sap_address_t) );
 371         if( !p_address )
 372         {
 373             vlc_object_unlock( p_sap );
 374             return VLC_ENOMEM;
 375         }
 376         p_address->psz_address = strdup( psz_addr );
 377         p_address->i_wfd = net_ConnectUDP( VLC_OBJECT(p_sap), psz_addr, SAP_PORT, 255 );
 378         if( p_address->i_wfd != -1 )
 379         {
 380             shutdown( p_address->i_wfd, SHUT_RD );
 381             p_address->origlen = sizeof (p_address->orig);
 382             getsockname (p_address->i_wfd, (struct sockaddr *)&p_address->orig,
 383                          &p_address->origlen);
 384         }
 385
 386         if( p_sap->b_control == true )
 387         {
 388             p_address->i_rfd = net_ListenUDP1( (vlc_object_t*)p_sap, psz_addr, SAP_PORT );
 389             if( p_address->i_rfd != -1 )
 390                 shutdown( p_address->i_rfd, SHUT_WR );
 391             p_address->i_buff = 0;
 392             p_address->b_enabled = true;
 393             p_address->b_ready = false;
 394             p_address->i_limit = 10000; /* 10000 bps */
 395             p_address->t1 = 0;
 396         }
 397         else
 398         {
 399             p_address->b_enabled = true;
 400             p_address->b_ready = true;
 401             p_address->i_interval = config_GetInt( p_sap,"sap-interval");
 402             p_address->i_rfd = -1;
 403         }
 404
 405         if( p_address->i_wfd == -1 || (p_address->i_rfd == -1
 406                                         && p_sap->b_control ) )
 407         {
 408             msg_Warn( p_sap, "disabling address" );
 409             p_address->b_enabled = false;
 410         }
 411
 412         INSERT_ELEM( p_sap->pp_addresses,
 413                      p_sap->i_addresses,
 414                      p_sap->i_addresses,
 415                      p_address );
 416         p_sap_session->p_address = p_address;
 417     }
 418
 419     memcpy (&p_session->orig, &p_sap_session->p_address->orig,
 420              p_session->origlen = p_sap_session->p_address->origlen);
 421
 422     size_t headsize = 20;
 423     switch (p_session->orig.ss_family)
 424     {
 425 #ifdef AF_INET6
 426         case AF_INET6:
 427             headsize += 16;
 428             break;
 429 #endif
 430         case AF_INET:
 431             headsize += 4;
 432             break;
 433         default:
 434             msg_Err( p_sap, "Address family %d not supported by SAP",
 435                      addr.ss_family );
 436             vlc_object_unlock( p_sap );
 437             return VLC_EGENERIC;
 438     }
 439
 440     /* If needed, build the SDP */
 441     assert( p_session->psz_sdp != NULL );
 442
 443     p_sap_session->i_last = 0;
 444     p_sap_session->i_length = headsize + strlen (p_session->psz_sdp);
 445     p_sap_session->psz_data = malloc (p_sap_session->i_length + 1);
 446     if (p_sap_session->psz_data == NULL)
 447     {
 448         free (p_session->psz_sdp);
 449         vlc_object_unlock( p_sap );
 450         return VLC_ENOMEM;
 451     }
 452
 453     /* Build the SAP Headers */
 454     uint8_t *psz_head = p_sap_session->psz_data;
 455
 456     /* SAPv1, not encrypted, not compressed */
 457     psz_head[0] = 0x20;
 458     psz_head[1] = 0x00; /* No authentification length */
 459
 460     i_hash = mdate();
 461     psz_head[2] = i_hash >> 8; /* Msg id hash */
 462     psz_head[3] = i_hash;      /* Msg id hash 2 */
 463
 464     headsize = 4;
 465     switch (p_session->orig.ss_family)
 466     {
 467 #ifdef AF_INET6
 468         case AF_INET6:
 469         {
 470             struct in6_addr *a6 =
 471                 &((struct sockaddr_in6 *)&p_session->orig)->sin6_addr;
 472             memcpy (psz_head + headsize, a6, 16);
 473             psz_head[0] |= 0x10; /* IPv6 flag */
 474             headsize += 16;
 475             break;
 476         }
 477 #endif
 478         case AF_INET:
 479         {
 480             uint32_t ipv4 =
 481                 (((struct sockaddr_in *)&p_session->orig)->sin_addr.s_addr);
 482             memcpy (psz_head + headsize, &ipv4, 4);
 483             headsize += 4;
 484             break;
 485         }
 486
 487     }
 488
 489     memcpy (psz_head + headsize, "application/sdp", 16);
 490     headsize += 16;
 491
 492     /* Build the final message */
 493     strcpy( (char *)psz_head + headsize, p_session->psz_sdp);
 494
 495     /* Enqueue the announce */
 496     INSERT_ELEM( p_sap->pp_sessions,
 497                  p_sap->i_sessions,
 498                  p_sap->i_sessions,
 499                  p_sap_session );
 500     msg_Dbg( p_sap,"%i addresses, %i sessions",
 501                    p_sap->i_addresses,p_sap->i_sessions);
 502
 503     vlc_object_unlock( p_sap );
 504
 505     return VLC_SUCCESS;
 506 }
 507
 508 /* Remove a SAP Announce */
 509 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
 510                              session_descriptor_t *p_session )
 511 {
 512     int i;
 513     vlc_object_lock( p_sap );
 514
 515     msg_Dbg( p_sap, "removing session %p from SAP", p_session);
 516
 517     /* Dequeue the announce */
 518     for( i = 0; i< p_sap->i_sessions; i++)
 519     {
 520         if( p_session == p_sap->pp_sessions[i]->p_sd )
 521         {
 522             free( p_session->psz_sdp );
 523             sap_session_t *p_mysession = p_sap->pp_sessions[i];
 524             REMOVE_ELEM( p_sap->pp_sessions,
 525                          p_sap->i_sessions,
 526                          i );
 527
 528             free( p_mysession->psz_data );
 529             free( p_mysession );
 530             break;
 531         }
 532     }
 533
 534     /* XXX: Dequeue the address too if it is not used anymore
 535      * TODO: - address refcount
 536              - send a SAP deletion packet */
 537
 538     msg_Dbg( p_sap,"%i announcements remaining", p_sap->i_sessions );
 539
 540     vlc_object_unlock( p_sap );
 541
 542     return VLC_SUCCESS;
 543 }
 544
 545 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
 546                                      sap_session_t *p_session )
 547 {
 548     int i_ret;
 549
 550     /* This announce has never been sent yet */
 551     if( p_session->i_last == 0 )
 552     {
 553         p_session->i_next = mdate()+ p_session->p_address->i_interval*1000000;
 554         p_session->i_last = 1;
 555         return VLC_SUCCESS;
 556     }
 557
 558     if( p_session->i_next < mdate() )
 559     {
 560 #ifdef EXTRA_DEBUG
 561         msg_Dbg( p_sap, "sending announce");
 562 #endif
 563         i_ret = net_Write( p_sap, p_session->p_address->i_wfd, NULL,
 564                            p_session->psz_data,
 565                            p_session->i_length );
 566         if( i_ret != (int)p_session->i_length )
 567         {
 568             msg_Warn( p_sap, "SAP send failed on address %s (%i %i)",
 569                       p_session->p_address->psz_address,
 570                       i_ret, p_session->i_length );
 571         }
 572         p_session->i_last = p_session->i_next;
 573         p_session->i_next = p_session->i_last
 574                             + p_session->p_address->i_interval*1000000;
 575     }
 576     return VLC_SUCCESS;
 577 }
 578
 579 static int ComputeRate( sap_address_t *p_address )
 580 {
 581     uint8_t buffer[SAP_MAX_BUFFER];
 582     ssize_t i_tot = 0;
 583     mtime_t i_temp;
 584     int i_rate;
 585
 586     if( p_address->t1 == 0 )
 587     {
 588         p_address->t1 = mdate();
 589         return VLC_SUCCESS;
 590     }
 591     for (;;)
 592     {
 593         /* Might be too slow if we have huge data */
 594         ssize_t i_read = recv( p_address->i_rfd, buffer, SAP_MAX_BUFFER, 0 );
 595         if (i_read == -1)
 596             break;
 597         i_tot += i_read;
 598     }
 599
 600     i_temp = mdate();
 601
 602     /* We calculate the rate every 5 seconds */
 603     if( i_temp - p_address->t1 < 5000000 )
 604     {
 605         p_address->i_buff += i_tot;
 606         return VLC_SUCCESS;
 607     }
 608
 609     /* Bits/second */
 610     i_rate = (int)(8*1000000*((mtime_t)p_address->i_buff + (mtime_t)i_tot ) /
 611                         (i_temp - p_address->t1 ));
 612
 613     p_address->i_limit = 10000;
 614
 615     p_address->i_interval = ((1000*i_rate / p_address->i_limit) *
 616                             (MAX_INTERVAL - MIN_INTERVAL))/1000 + MIN_INTERVAL;
 617
 618     if( p_address->i_interval > MAX_INTERVAL || p_address->i_interval < 0 )
 619     {
 620         p_address->i_interval = MAX_INTERVAL;
 621     }
 622 #ifdef EXTRA_DEBUG
 623     msg_Dbg( p_sap,"%s:%i: rate=%i, interval = %i s",
 624              p_address->psz_address,SAP_PORT, i_rate, p_address->i_interval );
 625 #endif
 626
 627     p_address->b_ready = true;
 628
 629     p_address->t1 = i_temp;
 630     p_address->i_buff = 0;
 631
 632     return VLC_SUCCESS;
 633 }