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     int canc = vlc_savecancel ();
 196     /* TODO: Once net_Write() is cancel-safe, so will this whole thread.
 197      * However, there is a more serious issues here: msleep(SAP_IDLE).
 198      * This thread should really use poll().
 199      */
 200
 201     while( !p_sap->b_die )
 202     {
 203         int i;
 204
 205         msleep( SAP_IDLE );
 206
 207         /* If needed, get the rate info */
 208         if( p_sap->b_control == true )
 209         {
 210             for( i = 0 ; i< p_sap->i_addresses ; i++)
 211             {
 212                 if( p_sap->pp_addresses[i]->b_enabled == true )
 213                 {
 214                     ComputeRate( p_sap->pp_addresses[i] );
 215                 }
 216             }
 217         }
 218
 219         /* Find the session to announce */
 220         vlc_object_lock( p_sap );
 221         if( p_sap->i_sessions > p_sap->i_current_session + 1)
 222         {
 223             p_sap->i_current_session++;
 224         }
 225         else if( p_sap->i_sessions > 0)
 226         {
 227             p_sap->i_current_session = 0;
 228         }
 229         else
 230         {
 231             vlc_object_unlock( p_sap );
 232             continue;
 233         }
 234         p_session = p_sap->pp_sessions[p_sap->i_current_session];
 235
 236         /* And announce it */
 237         if( p_session->p_address->b_enabled == true &&
 238             p_session->p_address->b_ready == true )
 239         {
 240             announce_SendSAPAnnounce( p_sap, p_session );
 241         }
 242         vlc_object_unlock( p_sap );
 243     }
 244     vlc_restorecancel (canc);
 245     return NULL;
 246 }
 247
 248 /* Add a SAP announce */
 249 static int announce_SAPAnnounceAdd( sap_handler_t *p_sap,
 250                              session_descriptor_t *p_session )
 251 {
 252     int i;
 253     char psz_addr[NI_MAXNUMERICHOST];
 254     bool b_ipv6 = false, b_ssm = false;
 255     sap_session_t *p_sap_session;
 256     mtime_t i_hash;
 257     struct sockaddr_storage addr;
 258     socklen_t addrlen;
 259
 260     vlc_object_lock( p_sap );
 261     addrlen = p_session->addrlen;
 262     if ((addrlen == 0) || (addrlen > sizeof (addr)))
 263     {
 264         vlc_object_unlock( p_sap );
 265         msg_Err( p_sap, "No/invalid address specified for SAP announce" );
 266         return VLC_EGENERIC;
 267     }
 268
 269     /* Determine SAP multicast address automatically */
 270     memcpy (&addr, &p_session->addr, addrlen);
 271
 272     switch( p_session->addr.ss_family )
 273     {
 274 #if defined (HAVE_INET_PTON) || defined (WIN32)
 275         case AF_INET6:
 276         {
 277             /* See RFC3513 for list of valid IPv6 scopes */
 278             struct in6_addr *a6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
 279
 280             memcpy( a6->s6_addr + 2, "\x00\x00\x00\x00\x00\x00"
 281                    "\x00\x00\x00\x00\x00\x02\x7f\xfe", 14 );
 282             if( IN6_IS_ADDR_MULTICAST( a6 ) )
 283             {
 284                 /* SSM <=> ff3x::/32 */
 285                 b_ssm = (U32_AT (a6->s6_addr) & 0xfff0ffff) == 0xff300000;
 286
 287                 /* force flags to zero, preserve scope */
 288                 a6->s6_addr[1] &= 0xf;
 289             }
 290             else
 291                 /* Unicast IPv6 - assume global scope */
 292                 memcpy( a6->s6_addr, "\xff\x0e", 2 );
 293
 294             b_ipv6 = true;
 295             break;
 296         }
 297 #endif
 298
 299         case AF_INET:
 300         {
 301             /* See RFC2365 for IPv4 scopes */
 302             uint32_t ipv4;
 303
 304             ipv4 = ntohl( ((struct sockaddr_in *)&addr)->sin_addr.s_addr );
 305             /* 224.0.0.0/24 => 224.0.0.255 */
 306             if ((ipv4 & 0xffffff00) == 0xe0000000)
 307                 ipv4 =  0xe00000ff;
 308             else
 309             /* 239.255.0.0/16 => 239.255.255.255 */
 310             if ((ipv4 & 0xffff0000) == 0xefff0000)
 311                 ipv4 =  0xefffffff;
 312             else
 313             /* 239.192.0.0/14 => 239.195.255.255 */
 314             if ((ipv4 & 0xfffc0000) == 0xefc00000)
 315                 ipv4 =  0xefc3ffff;
 316             else
 317             if ((ipv4 & 0xff000000) == 0xef000000)
 318                 ipv4 = 0;
 319             else
 320             /* other addresses => 224.2.127.254 */
 321             {
 322                 /* SSM: 232.0.0.0/8 */
 323                 b_ssm = (ipv4 >> 24) == 232;
 324                 ipv4 = 0xe0027ffe;
 325             }
 326
 327             if( ipv4 == 0 )
 328             {
 329                 msg_Err( p_sap, "Out-of-scope multicast address "
 330                          "not supported by SAP" );
 331                 vlc_object_unlock( p_sap );
 332                 return VLC_EGENERIC;
 333             }
 334
 335             ((struct sockaddr_in *)&addr)->sin_addr.s_addr = htonl( ipv4 );
 336             break;
 337         }
 338
 339         default:
 340             vlc_object_unlock( p_sap );
 341             msg_Err( p_sap, "Address family %d not supported by SAP",
 342                      addr.ss_family );
 343             return VLC_EGENERIC;
 344     }
 345
 346     i = vlc_getnameinfo( (struct sockaddr *)&addr, addrlen,
 347                          psz_addr, sizeof( psz_addr ), NULL, NI_NUMERICHOST );
 348
 349     if( i )
 350     {
 351         vlc_object_unlock( p_sap );
 352         msg_Err( p_sap, "%s", vlc_gai_strerror( i ) );
 353         return VLC_EGENERIC;
 354     }
 355
 356     msg_Dbg( p_sap, "using SAP address: %s", psz_addr);
 357
 358     /* XXX: Check for dupes */
 359     p_sap_session = (sap_session_t*)malloc(sizeof(sap_session_t));
 360     p_sap_session->p_sd = p_session;
 361     p_sap_session->p_address = NULL;
 362
 363     /* Add the address to the buffer */
 364     for( i = 0; i < p_sap->i_addresses; i++)
 365     {
 366         if( !strcmp( psz_addr, p_sap->pp_addresses[i]->psz_address ) )
 367         {
 368             p_sap_session->p_address = p_sap->pp_addresses[i];
 369             break;
 370         }
 371     }
 372
 373     if( p_sap_session->p_address == NULL )
 374     {
 375         sap_address_t *p_address = (sap_address_t *)
 376                                     malloc( sizeof(sap_address_t) );
 377         if( !p_address )
 378         {
 379             vlc_object_unlock( p_sap );
 380             return VLC_ENOMEM;
 381         }
 382         p_address->psz_address = strdup( psz_addr );
 383         p_address->i_wfd = net_ConnectUDP( VLC_OBJECT(p_sap), psz_addr, SAP_PORT, 255 );
 384         if( p_address->i_wfd != -1 )
 385         {
 386             shutdown( p_address->i_wfd, SHUT_RD );
 387             p_address->origlen = sizeof (p_address->orig);
 388             getsockname (p_address->i_wfd, (struct sockaddr *)&p_address->orig,
 389                          &p_address->origlen);
 390         }
 391
 392         if( p_sap->b_control == true )
 393         {
 394             p_address->i_rfd = net_ListenUDP1( (vlc_object_t*)p_sap, psz_addr, SAP_PORT );
 395             if( p_address->i_rfd != -1 )
 396                 shutdown( p_address->i_rfd, SHUT_WR );
 397             p_address->i_buff = 0;
 398             p_address->b_enabled = true;
 399             p_address->b_ready = false;
 400             p_address->i_limit = 10000; /* 10000 bps */
 401             p_address->t1 = 0;
 402         }
 403         else
 404         {
 405             p_address->b_enabled = true;
 406             p_address->b_ready = true;
 407             p_address->i_interval = config_GetInt( p_sap,"sap-interval");
 408             p_address->i_rfd = -1;
 409         }
 410
 411         if( p_address->i_wfd == -1 || (p_address->i_rfd == -1
 412                                         && p_sap->b_control ) )
 413         {
 414             msg_Warn( p_sap, "disabling address" );
 415             p_address->b_enabled = false;
 416         }
 417
 418         INSERT_ELEM( p_sap->pp_addresses,
 419                      p_sap->i_addresses,
 420                      p_sap->i_addresses,
 421                      p_address );
 422         p_sap_session->p_address = p_address;
 423     }
 424
 425     memcpy (&p_session->orig, &p_sap_session->p_address->orig,
 426              p_session->origlen = p_sap_session->p_address->origlen);
 427
 428     size_t headsize = 20;
 429     switch (p_session->orig.ss_family)
 430     {
 431 #ifdef AF_INET6
 432         case AF_INET6:
 433             headsize += 16;
 434             break;
 435 #endif
 436         case AF_INET:
 437             headsize += 4;
 438             break;
 439         default:
 440             msg_Err( p_sap, "Address family %d not supported by SAP",
 441                      addr.ss_family );
 442             vlc_object_unlock( p_sap );
 443             return VLC_EGENERIC;
 444     }
 445
 446     /* If needed, build the SDP */
 447     assert( p_session->psz_sdp != NULL );
 448
 449     p_sap_session->i_last = 0;
 450     p_sap_session->i_length = headsize + strlen (p_session->psz_sdp);
 451     p_sap_session->psz_data = malloc (p_sap_session->i_length + 1);
 452     if (p_sap_session->psz_data == NULL)
 453     {
 454         free (p_session->psz_sdp);
 455         vlc_object_unlock( p_sap );
 456         return VLC_ENOMEM;
 457     }
 458
 459     /* Build the SAP Headers */
 460     uint8_t *psz_head = p_sap_session->psz_data;
 461
 462     /* SAPv1, not encrypted, not compressed */
 463     psz_head[0] = 0x20;
 464     psz_head[1] = 0x00; /* No authentification length */
 465
 466     i_hash = mdate();
 467     psz_head[2] = i_hash >> 8; /* Msg id hash */
 468     psz_head[3] = i_hash;      /* Msg id hash 2 */
 469
 470     headsize = 4;
 471     switch (p_session->orig.ss_family)
 472     {
 473 #ifdef AF_INET6
 474         case AF_INET6:
 475         {
 476             struct in6_addr *a6 =
 477                 &((struct sockaddr_in6 *)&p_session->orig)->sin6_addr;
 478             memcpy (psz_head + headsize, a6, 16);
 479             psz_head[0] |= 0x10; /* IPv6 flag */
 480             headsize += 16;
 481             break;
 482         }
 483 #endif
 484         case AF_INET:
 485         {
 486             uint32_t ipv4 =
 487                 (((struct sockaddr_in *)&p_session->orig)->sin_addr.s_addr);
 488             memcpy (psz_head + headsize, &ipv4, 4);
 489             headsize += 4;
 490             break;
 491         }
 492
 493     }
 494
 495     memcpy (psz_head + headsize, "application/sdp", 16);
 496     headsize += 16;
 497
 498     /* Build the final message */
 499     strcpy( (char *)psz_head + headsize, p_session->psz_sdp);
 500
 501     /* Enqueue the announce */
 502     INSERT_ELEM( p_sap->pp_sessions,
 503                  p_sap->i_sessions,
 504                  p_sap->i_sessions,
 505                  p_sap_session );
 506     msg_Dbg( p_sap,"%i addresses, %i sessions",
 507                    p_sap->i_addresses,p_sap->i_sessions);
 508
 509     vlc_object_unlock( p_sap );
 510
 511     return VLC_SUCCESS;
 512 }
 513
 514 /* Remove a SAP Announce */
 515 static int announce_SAPAnnounceDel( sap_handler_t *p_sap,
 516                              session_descriptor_t *p_session )
 517 {
 518     int i;
 519     vlc_object_lock( p_sap );
 520
 521     msg_Dbg( p_sap, "removing session %p from SAP", p_session);
 522
 523     /* Dequeue the announce */
 524     for( i = 0; i< p_sap->i_sessions; i++)
 525     {
 526         if( p_session == p_sap->pp_sessions[i]->p_sd )
 527         {
 528             free( p_session->psz_sdp );
 529             sap_session_t *p_mysession = p_sap->pp_sessions[i];
 530             REMOVE_ELEM( p_sap->pp_sessions,
 531                          p_sap->i_sessions,
 532                          i );
 533
 534             free( p_mysession->psz_data );
 535             free( p_mysession );
 536             break;
 537         }
 538     }
 539
 540     /* XXX: Dequeue the address too if it is not used anymore
 541      * TODO: - address refcount
 542              - send a SAP deletion packet */
 543
 544     msg_Dbg( p_sap,"%i announcements remaining", p_sap->i_sessions );
 545
 546     vlc_object_unlock( p_sap );
 547
 548     return VLC_SUCCESS;
 549 }
 550
 551 static int announce_SendSAPAnnounce( sap_handler_t *p_sap,
 552                                      sap_session_t *p_session )
 553 {
 554     int i_ret;
 555
 556     /* This announce has never been sent yet */
 557     if( p_session->i_last == 0 )
 558     {
 559         p_session->i_next = mdate()+ p_session->p_address->i_interval*1000000;
 560         p_session->i_last = 1;
 561         return VLC_SUCCESS;
 562     }
 563
 564     if( p_session->i_next < mdate() )
 565     {
 566 #ifdef EXTRA_DEBUG
 567         msg_Dbg( p_sap, "sending announce");
 568 #endif
 569         i_ret = net_Write( p_sap, p_session->p_address->i_wfd, NULL,
 570                            p_session->psz_data,
 571                            p_session->i_length );
 572         if( i_ret != (int)p_session->i_length )
 573         {
 574             msg_Warn( p_sap, "SAP send failed on address %s (%i %i)",
 575                       p_session->p_address->psz_address,
 576                       i_ret, p_session->i_length );
 577         }
 578         p_session->i_last = p_session->i_next;
 579         p_session->i_next = p_session->i_last
 580                             + p_session->p_address->i_interval*1000000;
 581     }
 582     return VLC_SUCCESS;
 583 }
 584
 585 static int ComputeRate( sap_address_t *p_address )
 586 {
 587     uint8_t buffer[SAP_MAX_BUFFER];
 588     ssize_t i_tot = 0;
 589     mtime_t i_temp;
 590     int i_rate;
 591
 592     if( p_address->t1 == 0 )
 593     {
 594         p_address->t1 = mdate();
 595         return VLC_SUCCESS;
 596     }
 597     for (;;)
 598     {
 599         /* Might be too slow if we have huge data */
 600         ssize_t i_read = recv( p_address->i_rfd, buffer, SAP_MAX_BUFFER, 0 );
 601         if (i_read == -1)
 602             break;
 603         i_tot += i_read;
 604     }
 605
 606     i_temp = mdate();
 607
 608     /* We calculate the rate every 5 seconds */
 609     if( i_temp - p_address->t1 < 5000000 )
 610     {
 611         p_address->i_buff += i_tot;
 612         return VLC_SUCCESS;
 613     }
 614
 615     /* Bits/second */
 616     i_rate = (int)(8*1000000*((mtime_t)p_address->i_buff + (mtime_t)i_tot ) /
 617                         (i_temp - p_address->t1 ));
 618
 619     p_address->i_limit = 10000;
 620
 621     p_address->i_interval = ((1000*i_rate / p_address->i_limit) *
 622                             (MAX_INTERVAL - MIN_INTERVAL))/1000 + MIN_INTERVAL;
 623
 624     if( p_address->i_interval > MAX_INTERVAL || p_address->i_interval < 0 )
 625     {
 626         p_address->i_interval = MAX_INTERVAL;
 627     }
 628 #ifdef EXTRA_DEBUG
 629     msg_Dbg( p_sap,"%s:%i: rate=%i, interval = %i s",
 630              p_address->psz_address,SAP_PORT, i_rate, p_address->i_interval );
 631 #endif
 632
 633     p_address->b_ready = true;
 634
 635     p_address->t1 = i_temp;
 636     p_address->i_buff = 0;
 637
 638     return VLC_SUCCESS;
 639 }