src/network/udp.c

   1 /*****************************************************************************
   2  * udp.c:
   3  *****************************************************************************
   4  * Copyright (C) 2004-2006 the VideoLAN team
   5  * Copyright © 2006-2007 Rémi Denis-Courmont
   6  *
   7  * $Id$
   8  *
   9  * Authors: Laurent Aimar <fenrir@videolan.org>
  10  *          Rémi Denis-Courmont <rem # videolan.org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30 #ifdef HAVE_CONFIG_H
  31 # include "config.h"
  32 #endif
  33
  34 #include <vlc_common.h>
  35
  36 #include <errno.h>
  37
  38 #include <vlc_network.h>
  39
  40 #ifdef WIN32
  41 #   if defined(UNDER_CE)
  42 #       undef IP_MULTICAST_TTL
  43 #       define IP_MULTICAST_TTL 3
  44 #       undef IP_ADD_MEMBERSHIP
  45 #       define IP_ADD_MEMBERSHIP 5
  46 #   endif
  47 #   define EAFNOSUPPORT WSAEAFNOSUPPORT
  48 #   define if_nametoindex( str ) atoi( str )
  49 #else
  50 #   include <unistd.h>
  51 #   ifdef HAVE_NET_IF_H
  52 #       include <net/if.h>
  53 #   endif
  54 #endif
  55
  56 #ifdef HAVE_LINUX_DCCP_H
  57 # include <linux/dccp.h>
  58 # ifndef SOCK_DCCP /* provisional API */
  59 #  define SOCK_DCCP 6
  60 # endif
  61 #endif
  62
  63 #ifndef SOL_IP
  64 # define SOL_IP IPPROTO_IP
  65 #endif
  66 #ifndef SOL_IPV6
  67 # define SOL_IPV6 IPPROTO_IPV6
  68 #endif
  69 #ifndef IPPROTO_IPV6
  70 # define IPPROTO_IPV6 41 /* IANA */
  71 #endif
  72 #ifndef SOL_DCCP
  73 # define SOL_DCCP IPPROTO_DCCP
  74 #endif
  75 #ifndef IPPROTO_DCCP
  76 # define IPPROTO_DCCP 33 /* IANA */
  77 #endif
  78 #ifndef SOL_UDPLITE
  79 # define SOL_UDPLITE IPPROTO_UDPLITE
  80 #endif
  81 #ifndef IPPROTO_UDPLITE
  82 # define IPPROTO_UDPLITE 136 /* IANA */
  83 #endif
  84
  85 #if defined (HAVE_NETINET_UDPLITE_H)
  86 # include <netinet/udplite.h>
  87 #elif defined (__linux__)
  88 /* still missing from glibc 2.6 */
  89 # define UDPLITE_SEND_CSCOV     10
  90 # define UDPLITE_RECV_CSCOV     11
  91 #endif
  92
  93 extern int net_Socket( vlc_object_t *p_this, int i_family, int i_socktype,
  94                        int i_protocol );
  95
  96 /* */
  97 static int net_SetupDgramSocket( vlc_object_t *p_obj, int fd, const struct addrinfo *ptr )
  98 {
  99 #ifdef SO_REUSEPORT
 100     setsockopt (fd, SOL_SOCKET, SO_REUSEPORT, &(int){ 1 }, sizeof (int));
 101 #endif
 102
 103 #ifdef SO_RCVBUF
 104     /* Increase the receive buffer size to 1/2MB (8Mb/s during 1/2s)
 105      * to avoid packet loss caused in case of scheduling hiccups */
 106     setsockopt (fd, SOL_SOCKET, SO_RCVBUF,
 107                 (void *)&(int){ 0x80000 }, sizeof (int));
 108     setsockopt (fd, SOL_SOCKET, SO_SNDBUF,
 109                 (void *)&(int){ 0x80000 }, sizeof (int));
 110 #endif
 111
 112 #if defined (WIN32) || defined (UNDER_CE)
 113     if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
 114      && (sizeof (struct sockaddr_storage) >= ptr->ai_addrlen))
 115     {
 116         // This works for IPv4 too - don't worry!
 117         struct sockaddr_in6 dumb =
 118         {
 119             .sin6_family = ptr->ai_addr->sa_family,
 120             .sin6_port =  ((struct sockaddr_in *)(ptr->ai_addr))->sin_port
 121         };
 122
 123         bind (fd, (struct sockaddr *)&dumb, ptr->ai_addrlen);
 124     }
 125     else
 126 #endif
 127     if (bind (fd, ptr->ai_addr, ptr->ai_addrlen))
 128     {
 129         msg_Err( p_obj, "socket bind error (%m)" );
 130         net_Close (fd);
 131         return -1;
 132     }
 133     return fd;
 134 }
 135
 136 /* */
 137 static int net_ListenSingle (vlc_object_t *obj, const char *host, int port,
 138                              int family, int protocol)
 139 {
 140     struct addrinfo hints, *res;
 141
 142     memset (&hints, 0, sizeof( hints ));
 143     hints.ai_family = family;
 144     hints.ai_socktype = SOCK_DGRAM;
 145     hints.ai_protocol = protocol;
 146     hints.ai_flags = AI_PASSIVE;
 147
 148     if (host && !*host)
 149         host = NULL;
 150
 151     msg_Dbg (obj, "net: opening %s datagram port %d",
 152              host ? host : "any", port);
 153
 154     int val = vlc_getaddrinfo (obj, host, port, &hints, &res);
 155     if (val)
 156     {
 157         msg_Err (obj, "Cannot resolve %s port %d : %s", host, port,
 158                  gai_strerror (val));
 159         return -1;
 160     }
 161
 162     val = -1;
 163
 164     for (const struct addrinfo *ptr = res; ptr != NULL; ptr = ptr->ai_next)
 165     {
 166         int fd = net_Socket (obj, ptr->ai_family, ptr->ai_socktype,
 167                              ptr->ai_protocol);
 168         if (fd == -1)
 169         {
 170             msg_Dbg (obj, "socket error: %m");
 171             continue;
 172         }
 173
 174 #ifdef IPV6_V6ONLY
 175         /* If IPv6 was forced, set IPv6-only mode.
 176          * If IPv4 was forced, do nothing extraordinary.
 177          * If nothing was forced, try dual-mode IPv6. */
 178         if (ptr->ai_family == AF_INET6)
 179         {
 180             int on = (family == AF_INET6);
 181             setsockopt (fd, SOL_IPV6, IPV6_V6ONLY, &on, sizeof (on));
 182         }
 183         if (ptr->ai_family == AF_INET)
 184 #endif
 185         if (family == AF_UNSPEC && ptr->ai_next != NULL)
 186         {
 187             msg_Warn (obj, "ambiguous network protocol specification");
 188             msg_Warn (obj, "please select IP version explicitly");
 189         }
 190
 191         fd = net_SetupDgramSocket( obj, fd, ptr );
 192         if( fd == -1 )
 193             continue;
 194
 195         if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
 196          && net_Subscribe (obj, fd, ptr->ai_addr, ptr->ai_addrlen))
 197         {
 198             net_Close (fd);
 199             continue;
 200         }
 201
 202         val = fd;
 203         break;
 204     }
 205
 206     freeaddrinfo (res);
 207     return val;
 208 }
 209
 210
 211 static int net_SetMcastHopLimit( vlc_object_t *p_this,
 212                                  int fd, int family, int hlim )
 213 {
 214     int proto, cmd;
 215
 216     /* There is some confusion in the world whether IP_MULTICAST_TTL
 217      * takes a byte or an int as an argument.
 218      * BSD seems to indicate byte so we are going with that and use
 219      * int as a fallback to be safe */
 220     switch( family )
 221     {
 222 #ifdef IP_MULTICAST_TTL
 223         case AF_INET:
 224             proto = SOL_IP;
 225             cmd = IP_MULTICAST_TTL;
 226             break;
 227 #endif
 228
 229 #ifdef IPV6_MULTICAST_HOPS
 230         case AF_INET6:
 231             proto = SOL_IPV6;
 232             cmd = IPV6_MULTICAST_HOPS;
 233             break;
 234 #endif
 235
 236         default:
 237             errno = EAFNOSUPPORT;
 238             msg_Warn( p_this, "%m" );
 239             return VLC_EGENERIC;
 240     }
 241
 242     if( setsockopt( fd, proto, cmd, &hlim, sizeof( hlim ) ) < 0 )
 243     {
 244         /* BSD compatibility */
 245         unsigned char buf;
 246
 247         msg_Dbg( p_this, "cannot set hop limit (%d): %m", hlim );
 248         buf = (unsigned char)(( hlim > 255 ) ? 255 : hlim);
 249         if( setsockopt( fd, proto, cmd, &buf, sizeof( buf ) ) )
 250         {
 251             msg_Err( p_this, "cannot set hop limit (%d): %m", hlim );
 252             return VLC_EGENERIC;
 253         }
 254     }
 255
 256     return VLC_SUCCESS;
 257 }
 258
 259
 260 static int net_SetMcastOutIface (int fd, int family, int scope)
 261 {
 262     switch (family)
 263     {
 264 #ifdef IPV6_MULTICAST_IF
 265         case AF_INET6:
 266             return setsockopt (fd, SOL_IPV6, IPV6_MULTICAST_IF,
 267                                &scope, sizeof (scope));
 268 #endif
 269
 270 #ifdef __linux__
 271         case AF_INET:
 272         {
 273             struct ip_mreqn req = { .imr_ifindex = scope };
 274
 275             return setsockopt (fd, SOL_IP, IP_MULTICAST_IF, &req,
 276                                sizeof (req));
 277         }
 278 #endif
 279     }
 280
 281     errno = EAFNOSUPPORT;
 282     return -1;
 283 }
 284
 285
 286 static inline int net_SetMcastOutIPv4 (int fd, struct in_addr ipv4)
 287 {
 288 #ifdef IP_MULTICAST_IF
 289     return setsockopt( fd, SOL_IP, IP_MULTICAST_IF, &ipv4, sizeof (ipv4));
 290 #else
 291     errno = EAFNOSUPPORT;
 292     return -1;
 293 #endif
 294 }
 295
 296
 297 static int net_SetMcastOut (vlc_object_t *p_this, int fd, int family,
 298                             const char *iface, const char *addr)
 299 {
 300     if (iface != NULL)
 301     {
 302         int scope = if_nametoindex (iface);
 303         if (scope == 0)
 304         {
 305             msg_Err (p_this, "invalid multicast interface: %s", iface);
 306             return -1;
 307         }
 308
 309         if (net_SetMcastOutIface (fd, family, scope) == 0)
 310             return 0;
 311
 312         msg_Err (p_this, "%s: %m", iface);
 313     }
 314
 315     if (addr != NULL)
 316     {
 317         if (family == AF_INET)
 318         {
 319             struct in_addr ipv4;
 320             if (inet_pton (AF_INET, addr, &ipv4) <= 0)
 321             {
 322                 msg_Err (p_this, "invalid IPv4 address for multicast: %s",
 323                          addr);
 324                 return -1;
 325             }
 326
 327             if (net_SetMcastOutIPv4 (fd, ipv4) == 0)
 328                 return 0;
 329
 330             msg_Err (p_this, "%s: %m", addr);
 331         }
 332     }
 333
 334     return -1;
 335 }
 336
 337
 338 /**
 339  * Old-style any-source multicast join.
 340  * In use on Windows XP/2003 and older.
 341  */
 342 static int
 343 net_IPv4Join (vlc_object_t *obj, int fd,
 344               const struct sockaddr_in *src, const struct sockaddr_in *grp)
 345 {
 346 #ifdef IP_ADD_MEMBERSHIP
 347     union
 348     {
 349         struct ip_mreq gr4;
 350 # ifdef IP_ADD_SOURCE_MEMBERSHIP
 351         struct ip_mreq_source gsr4;
 352 # endif
 353     } opt;
 354     int cmd;
 355     struct in_addr id = { .s_addr = INADDR_ANY };
 356     socklen_t optlen;
 357
 358     /* Multicast interface IPv4 address */
 359     char *iface = var_CreateGetNonEmptyString (obj, "miface-addr");
 360     if ((iface != NULL)
 361      && (inet_pton (AF_INET, iface, &id) <= 0))
 362     {
 363         msg_Err (obj, "invalid multicast interface address %s", iface);
 364         free (iface);
 365         goto error;
 366     }
 367     free (iface);
 368
 369     memset (&opt, 0, sizeof (opt));
 370     if (src != NULL)
 371     {
 372 # ifdef IP_ADD_SOURCE_MEMBERSHIP
 373         cmd = IP_ADD_SOURCE_MEMBERSHIP;
 374         opt.gsr4.imr_multiaddr = grp->sin_addr;
 375         opt.gsr4.imr_sourceaddr = src->sin_addr;
 376         opt.gsr4.imr_interface = id;
 377         optlen = sizeof (opt.gsr4);
 378 # else
 379         errno = ENOSYS;
 380         goto error;
 381 # endif
 382     }
 383     else
 384     {
 385         cmd = IP_ADD_MEMBERSHIP;
 386         opt.gr4.imr_multiaddr = grp->sin_addr;
 387         opt.gr4.imr_interface = id;
 388         optlen = sizeof (opt.gr4);
 389     }
 390
 391     msg_Dbg (obj, "IP_ADD_%sMEMBERSHIP multicast request",
 392              (src != NULL) ? "SOURCE_" : "");
 393
 394     if (setsockopt (fd, SOL_IP, cmd, &opt, optlen) == 0)
 395         return 0;
 396
 397 error:
 398 #endif
 399
 400     msg_Err (obj, "cannot join IPv4 multicast group (%m)");
 401     return -1;
 402 }
 403
 404
 405 static int
 406 net_IPv6Join (vlc_object_t *obj, int fd, const struct sockaddr_in6 *src)
 407 {
 408 #ifdef IPV6_JOIN_GROUP
 409     struct ipv6_mreq gr6;
 410     memset (&gr6, 0, sizeof (gr6));
 411     gr6.ipv6mr_interface = src->sin6_scope_id;
 412     memcpy (&gr6.ipv6mr_multiaddr, &src->sin6_addr, 16);
 413
 414     msg_Dbg (obj, "IPV6_JOIN_GROUP multicast request");
 415
 416     if (!setsockopt (fd, SOL_IPV6, IPV6_JOIN_GROUP, &gr6, sizeof (gr6)))
 417         return 0;
 418 #else
 419     errno = ENOSYS;
 420 #endif
 421
 422     msg_Err (obj, "cannot join IPv6 any-source multicast group (%m)");
 423     return -1;
 424 }
 425
 426
 427 #if defined (WIN32) && !defined (MCAST_JOIN_SOURCE_GROUP)
 428 /*
 429  * I hate manual definitions: Error-prone. Portability hell.
 430  * Developers shall use UP-TO-DATE compilers. Full point.
 431  * If you remove the warning, you remove the whole ifndef.
 432  */
 433 #  warning Your C headers are out-of-date. Please update.
 434
 435 #  define MCAST_JOIN_GROUP 41
 436 struct group_req
 437 {
 438     ULONG gr_interface;
 439     struct sockaddr_storage gr_group;
 440 };
 441
 442 #  define MCAST_JOIN_SOURCE_GROUP 45 /* from <ws2ipdef.h> */
 443 struct group_source_req
 444 {
 445     uint32_t gsr_interface;
 446     struct sockaddr_storage gsr_group;
 447     struct sockaddr_storage gsr_source;
 448 };
 449 #endif
 450
 451 /**
 452  * IP-agnostic multicast join,
 453  * with fallback to old APIs, and fallback from SSM to ASM.
 454  */
 455 static int
 456 net_SourceSubscribe (vlc_object_t *obj, int fd,
 457                      const struct sockaddr *src, socklen_t srclen,
 458                      const struct sockaddr *grp, socklen_t grplen)
 459 {
 460     int level, iid = 0;
 461
 462     char *iface = var_CreateGetNonEmptyString (obj, "miface");
 463     if (iface != NULL)
 464     {
 465         iid = if_nametoindex (iface);
 466         if (iid == 0)
 467         {
 468             msg_Err (obj, "invalid multicast interface: %s", iface);
 469             free (iface);
 470             return -1;
 471         }
 472         free (iface);
 473     }
 474
 475     switch (grp->sa_family)
 476     {
 477 #ifdef AF_INET6
 478         case AF_INET6:
 479             level = SOL_IPV6;
 480             if (((const struct sockaddr_in6 *)grp)->sin6_scope_id)
 481                 iid = ((const struct sockaddr_in6 *)grp)->sin6_scope_id;
 482             break;
 483 #endif
 484
 485         case AF_INET:
 486             level = SOL_IP;
 487             break;
 488
 489         default:
 490             errno = EAFNOSUPPORT;
 491             return -1;
 492     }
 493
 494     if (src != NULL)
 495         switch (src->sa_family)
 496         {
 497 #ifdef AF_INET6
 498             case AF_INET6:
 499                 if (memcmp (&((const struct sockaddr_in6 *)src)->sin6_addr,
 500                             &in6addr_any, sizeof (in6addr_any)) == 0)
 501                     src = NULL;
 502             break;
 503 #endif
 504
 505             case AF_INET:
 506                 if (((const struct sockaddr_in *)src)->sin_addr.s_addr
 507                      == INADDR_ANY)
 508                     src = NULL;
 509                 break;
 510         }
 511
 512
 513     /* Agnostic ASM/SSM multicast join */
 514 #ifdef MCAST_JOIN_SOURCE_GROUP
 515     union
 516     {
 517         struct group_req gr;
 518         struct group_source_req gsr;
 519     } opt;
 520     socklen_t optlen;
 521
 522     memset (&opt, 0, sizeof (opt));
 523
 524     if (src != NULL)
 525     {
 526         if ((grplen > sizeof (opt.gsr.gsr_group))
 527          || (srclen > sizeof (opt.gsr.gsr_source)))
 528             return -1;
 529
 530         opt.gsr.gsr_interface = iid;
 531         memcpy (&opt.gsr.gsr_source, src, srclen);
 532         memcpy (&opt.gsr.gsr_group,  grp, grplen);
 533         optlen = sizeof (opt.gsr);
 534     }
 535     else
 536     {
 537         if (grplen > sizeof (opt.gr.gr_group))
 538             return -1;
 539
 540         opt.gr.gr_interface = iid;
 541         memcpy (&opt.gr.gr_group, grp, grplen);
 542         optlen = sizeof (opt.gr);
 543     }
 544
 545     msg_Dbg (obj, "Multicast %sgroup join request", src ? "source " : "");
 546
 547     if (setsockopt (fd, level,
 548                     src ? MCAST_JOIN_SOURCE_GROUP : MCAST_JOIN_GROUP,
 549                     (void *)&opt, optlen) == 0)
 550         return 0;
 551 #endif
 552
 553     /* Fallback to IPv-specific APIs */
 554     if ((src != NULL) && (src->sa_family != grp->sa_family))
 555         return -1;
 556
 557     switch (grp->sa_family)
 558     {
 559         case AF_INET:
 560             if ((grplen < sizeof (struct sockaddr_in))
 561              || ((src != NULL) && (srclen < sizeof (struct sockaddr_in))))
 562                 return -1;
 563
 564             if (net_IPv4Join (obj, fd, (const struct sockaddr_in *)src,
 565                               (const struct sockaddr_in *)grp) == 0)
 566                 return 0;
 567             break;
 568
 569 #ifdef AF_INET6
 570         case AF_INET6:
 571             if ((grplen < sizeof (struct sockaddr_in6))
 572              || ((src != NULL) && (srclen < sizeof (struct sockaddr_in6))))
 573                 return -1;
 574
 575             /* IPv6-specific SSM API does not exist. So if we're here
 576              * it means IPv6 SSM is not supported on this OS and we
 577              * directly fallback to ASM */
 578
 579             if (net_IPv6Join (obj, fd, (const struct sockaddr_in6 *)grp) == 0)
 580                 return 0;
 581             break;
 582 #endif
 583     }
 584
 585     msg_Err (obj, "Multicast group join error (%m)");
 586
 587     if (src != NULL)
 588     {
 589         msg_Warn (obj, "Trying ASM instead of SSM...");
 590         return net_Subscribe (obj, fd, grp, grplen);
 591     }
 592
 593     msg_Err (obj, "Multicast not supported");
 594     return -1;
 595 }
 596
 597
 598 int net_Subscribe (vlc_object_t *obj, int fd,
 599                    const struct sockaddr *addr, socklen_t addrlen)
 600 {
 601     return net_SourceSubscribe (obj, fd, NULL, 0, addr, addrlen);
 602 }
 603
 604
 605 static int net_SetDSCP( int fd, uint8_t dscp )
 606 {
 607     struct sockaddr_storage addr;
 608     if( getsockname( fd, (struct sockaddr *)&addr, &(socklen_t){ sizeof (addr) }) )
 609         return -1;
 610
 611     int level, cmd;
 612
 613     switch( addr.ss_family )
 614     {
 615 #ifdef IPV6_TCLASS
 616         case AF_INET6:
 617             level = SOL_IPV6;
 618             cmd = IPV6_TCLASS;
 619             break;
 620 #endif
 621
 622         case AF_INET:
 623             level = SOL_IP;
 624             cmd = IP_TOS;
 625             break;
 626
 627         default:
 628 #ifdef ENOPROTOOPT
 629             errno = ENOPROTOOPT;
 630 #endif
 631             return -1;
 632     }
 633
 634     return setsockopt( fd, level, cmd, &(int){ dscp }, sizeof (int));
 635 }
 636
 637 #undef net_ConnectDgram
 638 /*****************************************************************************
 639  * net_ConnectDgram:
 640  *****************************************************************************
 641  * Open a datagram socket to send data to a defined destination, with an
 642  * optional hop limit.
 643  *****************************************************************************/
 644 int net_ConnectDgram( vlc_object_t *p_this, const char *psz_host, int i_port,
 645                       int i_hlim, int proto )
 646 {
 647     struct addrinfo hints, *res, *ptr;
 648     int             i_val, i_handle = -1;
 649     bool      b_unreach = false;
 650
 651     if( i_hlim < 0 )
 652         i_hlim = var_CreateGetInteger( p_this, "ttl" );
 653
 654     memset( &hints, 0, sizeof( hints ) );
 655     hints.ai_socktype = SOCK_DGRAM;
 656     hints.ai_protocol = proto;
 657
 658     msg_Dbg( p_this, "net: connecting to [%s]:%d", psz_host, i_port );
 659
 660     i_val = vlc_getaddrinfo( p_this, psz_host, i_port, &hints, &res );
 661     if( i_val )
 662     {
 663         msg_Err( p_this, "cannot resolve [%s]:%d : %s", psz_host, i_port,
 664                  gai_strerror( i_val ) );
 665         return -1;
 666     }
 667
 668     for( ptr = res; ptr != NULL; ptr = ptr->ai_next )
 669     {
 670         char *str;
 671         int fd = net_Socket (p_this, ptr->ai_family, ptr->ai_socktype,
 672                              ptr->ai_protocol);
 673         if (fd == -1)
 674             continue;
 675
 676 #if !defined( SYS_BEOS )
 677         /* Increase the receive buffer size to 1/2MB (8Mb/s during 1/2s)
 678         * to avoid packet loss caused by scheduling problems */
 679         setsockopt (fd, SOL_SOCKET, SO_RCVBUF, &(int){ 0x80000 }, sizeof (int));
 680         setsockopt (fd, SOL_SOCKET, SO_SNDBUF, &(int){ 0x80000 }, sizeof (int));
 681
 682         /* Allow broadcast sending */
 683         setsockopt (fd, SOL_SOCKET, SO_BROADCAST, &(int){ 1 }, sizeof (int));
 684 #endif
 685
 686         if( i_hlim >= 0 )
 687             net_SetMcastHopLimit( p_this, fd, ptr->ai_family, i_hlim );
 688
 689         str = var_CreateGetNonEmptyString (p_this, "miface");
 690         if (str != NULL)
 691         {
 692             net_SetMcastOut (p_this, fd, ptr->ai_family, str, NULL);
 693             free (str);
 694         }
 695
 696         str = var_CreateGetNonEmptyString (p_this, "miface-addr");
 697         if (str != NULL)
 698         {
 699             net_SetMcastOut (p_this, fd, ptr->ai_family, NULL, str);
 700             free (str);
 701         }
 702
 703         net_SetDSCP (fd, var_CreateGetInteger (p_this, "dscp"));
 704
 705         if( connect( fd, ptr->ai_addr, ptr->ai_addrlen ) == 0 )
 706         {
 707             /* success */
 708             i_handle = fd;
 709             break;
 710         }
 711
 712 #if defined( WIN32 ) || defined( UNDER_CE )
 713         if( WSAGetLastError () == WSAENETUNREACH )
 714 #else
 715         if( errno == ENETUNREACH )
 716 #endif
 717             b_unreach = true;
 718         else
 719         {
 720             msg_Warn( p_this, "%s port %d : %m", psz_host, i_port);
 721             net_Close( fd );
 722             continue;
 723         }
 724     }
 725
 726     freeaddrinfo( res );
 727
 728     if( i_handle == -1 )
 729     {
 730         if( b_unreach )
 731             msg_Err( p_this, "Host %s port %d is unreachable", psz_host,
 732                      i_port );
 733         return -1;
 734     }
 735
 736     return i_handle;
 737 }
 738
 739 #undef net_OpenDgram
 740 /*****************************************************************************
 741  * net_OpenDgram:
 742  *****************************************************************************
 743  * OpenDgram a datagram socket and return a handle
 744  *****************************************************************************/
 745 int net_OpenDgram( vlc_object_t *obj, const char *psz_bind, int i_bind,
 746                    const char *psz_server, int i_server,
 747                    int family, int protocol )
 748 {
 749     if ((psz_server == NULL) || (psz_server[0] == '\0'))
 750         return net_ListenSingle (obj, psz_bind, i_bind, family, protocol);
 751
 752     msg_Dbg (obj, "net: connecting to [%s]:%d from [%s]:%d",
 753              psz_server, i_server, psz_bind, i_bind);
 754
 755     struct addrinfo hints, *loc, *rem;
 756     int val;
 757
 758     memset (&hints, 0, sizeof (hints));
 759     hints.ai_family = family;
 760     hints.ai_socktype = SOCK_DGRAM;
 761     hints.ai_protocol = protocol;
 762
 763     val = vlc_getaddrinfo (obj, psz_server, i_server, &hints, &rem);
 764     if (val)
 765     {
 766         msg_Err (obj, "cannot resolve %s port %d : %s", psz_bind, i_bind,
 767                  gai_strerror (val));
 768         return -1;
 769     }
 770
 771     hints.ai_flags = AI_PASSIVE;
 772     val = vlc_getaddrinfo (obj, psz_bind, i_bind, &hints, &loc);
 773     if (val)
 774     {
 775         msg_Err (obj, "cannot resolve %s port %d : %s", psz_bind, i_bind,
 776                  gai_strerror (val));
 777         freeaddrinfo (rem);
 778         return -1;
 779     }
 780
 781     val = -1;
 782     for (struct addrinfo *ptr = loc; ptr != NULL; ptr = ptr->ai_next)
 783     {
 784         int fd = net_Socket (obj, ptr->ai_family, ptr->ai_socktype,
 785                              ptr->ai_protocol);
 786         if (fd == -1)
 787             continue; // usually, address family not supported
 788
 789         fd = net_SetupDgramSocket( obj, fd, ptr );
 790         if( fd == -1 )
 791             continue;
 792
 793         for (struct addrinfo *ptr2 = rem; ptr2 != NULL; ptr2 = ptr2->ai_next)
 794         {
 795             if ((ptr2->ai_family != ptr->ai_family)
 796              || (ptr2->ai_socktype != ptr->ai_socktype)
 797              || (ptr2->ai_protocol != ptr->ai_protocol))
 798                 continue;
 799
 800             if (net_SockAddrIsMulticast (ptr->ai_addr, ptr->ai_addrlen)
 801               ? net_SourceSubscribe (obj, fd,
 802                                      ptr2->ai_addr, ptr2->ai_addrlen,
 803                                      ptr->ai_addr, ptr->ai_addrlen)
 804               : connect (fd, ptr2->ai_addr, ptr2->ai_addrlen))
 805             {
 806                 msg_Err (obj, "cannot connect to %s port %d: %m",
 807                          psz_server, i_server);
 808                 continue;
 809             }
 810             val = fd;
 811             break;
 812         }
 813
 814         if (val != -1)
 815             break;
 816
 817         net_Close (fd);
 818     }
 819
 820     freeaddrinfo (rem);
 821     freeaddrinfo (loc);
 822     return val;
 823 }
 824
 825
 826 /**
 827  * net_SetCSCov:
 828  * Sets the send and receive checksum coverage of a socket:
 829  * @param fd socket
 830  * @param sendcov payload coverage of sent packets (bytes), -1 for full
 831  * @param recvcov minimum payload coverage of received packets, -1 for full
 832  */
 833 int net_SetCSCov (int fd, int sendcov, int recvcov)
 834 {
 835     int type;
 836
 837     if (getsockopt (fd, SOL_SOCKET, SO_TYPE,
 838                     &type, &(socklen_t){ sizeof (type) }))
 839         return VLC_EGENERIC;
 840
 841     switch (type)
 842     {
 843 #ifdef UDPLITE_RECV_CSCOV
 844         case SOCK_DGRAM: /* UDP-Lite */
 845             if (sendcov == -1)
 846                 sendcov = 0;
 847             else
 848                 sendcov += 8; /* partial */
 849             if (setsockopt (fd, SOL_UDPLITE, UDPLITE_SEND_CSCOV, &sendcov,
 850                             sizeof (sendcov)))
 851                 return VLC_EGENERIC;
 852
 853             if (recvcov == -1)
 854                 recvcov = 0;
 855             else
 856                 recvcov += 8;
 857             if (setsockopt (fd, SOL_UDPLITE, UDPLITE_RECV_CSCOV,
 858                             &recvcov, sizeof (recvcov)))
 859                 return VLC_EGENERIC;
 860
 861             return VLC_SUCCESS;
 862 #endif
 863 #ifdef DCCP_SOCKOPT_SEND_CSCOV
 864         case SOCK_DCCP: /* DCCP and its ill-named socket type */
 865             if ((sendcov == -1) || (sendcov > 56))
 866                 sendcov = 0;
 867             else
 868                 sendcov = (sendcov + 3) / 4;
 869             if (setsockopt (fd, SOL_DCCP, DCCP_SOCKOPT_SEND_CSCOV,
 870                             &sendcov, sizeof (sendcov)))
 871                 return VLC_EGENERIC;
 872
 873             if ((recvcov == -1) || (recvcov > 56))
 874                 recvcov = 0;
 875             else
 876                 recvcov = (recvcov + 3) / 4;
 877             if (setsockopt (fd, SOL_DCCP, DCCP_SOCKOPT_RECV_CSCOV,
 878                             &recvcov, sizeof (recvcov)))
 879                 return VLC_EGENERIC;
 880
 881             return VLC_SUCCESS;
 882 #endif
 883     }
 884 #if !defined( UDPLITE_RECV_CSCOV ) && !defined( DCCP_SOCKOPT_SEND_CSCOV )
 885     VLC_UNUSED(sendcov);
 886     VLC_UNUSED(recvcov);
 887 #endif
 888
 889     return VLC_EGENERIC;
 890 }