src/network/tcp.c

   1 /*****************************************************************************
   2  * tcp.c:
   3  *****************************************************************************
   4  * Copyright (C) 2004-2005 VLC authors and VideoLAN
   5  * Copyright (C) 2005-2006 Rémi Denis-Courmont
   6  * $Id$
   7  *
   8  * Authors: Laurent Aimar <fenrir@videolan.org>
   9  *          Rémi Denis-Courmont <rem # videolan.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU Lesser General Public License as published by
  13  * the Free Software Foundation; either version 2.1 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * along with this program; if not, write to the Free Software Foundation,
  23  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc_common.h>
  34
  35 #include <errno.h>
  36 #include <assert.h>
  37
  38 #ifdef HAVE_UNISTD_H
  39 #   include <unistd.h>
  40 #endif
  41 #ifdef HAVE_POLL
  42 # include <poll.h>
  43 #endif
  44
  45 #include <vlc_network.h>
  46 #if defined (WIN32) || defined (UNDER_CE)
  47 #   undef EINPROGRESS
  48 #   define EINPROGRESS WSAEWOULDBLOCK
  49 #   undef EWOULDBLOCK
  50 #   define EWOULDBLOCK WSAEWOULDBLOCK
  51 #   undef EINTR
  52 #   define EINTR WSAEINTR
  53 #   undef ETIMEDOUT
  54 #   define ETIMEDOUT WSAETIMEDOUT
  55 #endif
  56
  57 #include "libvlc.h" /* vlc_object_waitpipe */
  58
  59 static int SocksNegotiate( vlc_object_t *, int fd, int i_socks_version,
  60                            const char *psz_user, const char *psz_passwd );
  61 static int SocksHandshakeTCP( vlc_object_t *,
  62                               int fd, int i_socks_version,
  63                               const char *psz_user, const char *psz_passwd,
  64                               const char *psz_host, int i_port );
  65 extern int net_Socket( vlc_object_t *p_this, int i_family, int i_socktype,
  66                        int i_protocol );
  67
  68 #undef net_Connect
  69 /*****************************************************************************
  70  * net_Connect:
  71  *****************************************************************************
  72  * Open a network connection.
  73  * @return socket handler or -1 on error.
  74  *****************************************************************************/
  75 int net_Connect( vlc_object_t *p_this, const char *psz_host, int i_port,
  76                  int type, int proto )
  77 {
  78     struct addrinfo hints, *res, *ptr;
  79     const char      *psz_realhost;
  80     char            *psz_socks;
  81     int             i_realport, i_val, i_handle = -1;
  82
  83     int evfd = vlc_object_waitpipe (p_this);
  84     if (evfd == -1)
  85         return -1;
  86
  87     memset( &hints, 0, sizeof( hints ) );
  88     hints.ai_socktype = type;
  89     hints.ai_protocol = proto;
  90
  91     psz_socks = var_InheritString( p_this, "socks" );
  92     if( psz_socks != NULL )
  93     {
  94         char *psz = strchr( psz_socks, ':' );
  95
  96         if( psz )
  97             *psz++ = '\0';
  98
  99         psz_realhost = psz_socks;
 100         i_realport = ( psz != NULL ) ? atoi( psz ) : 1080;
 101         hints.ai_flags &= ~AI_NUMERICHOST;
 102
 103         msg_Dbg( p_this, "net: connecting to %s port %d (SOCKS) "
 104                  "for %s port %d", psz_realhost, i_realport,
 105                  psz_host, i_port );
 106
 107         /* We only implement TCP with SOCKS */
 108         switch( type )
 109         {
 110             case 0:
 111                 type = SOCK_STREAM;
 112             case SOCK_STREAM:
 113                 break;
 114             default:
 115                 msg_Err( p_this, "Socket type not supported through SOCKS" );
 116                 free( psz_socks );
 117                 return -1;
 118         }
 119         switch( proto )
 120         {
 121             case 0:
 122                 proto = IPPROTO_TCP;
 123             case IPPROTO_TCP:
 124                 break;
 125             default:
 126                 msg_Err( p_this, "Transport not supported through SOCKS" );
 127                 free( psz_socks );
 128                 return -1;
 129         }
 130     }
 131     else
 132     {
 133         psz_realhost = psz_host;
 134         i_realport = i_port;
 135
 136         msg_Dbg( p_this, "net: connecting to %s port %d", psz_realhost,
 137                  i_realport );
 138     }
 139
 140     i_val = vlc_getaddrinfo( p_this, psz_realhost, i_realport, &hints, &res );
 141     free( psz_socks );
 142
 143     if( i_val )
 144     {
 145         msg_Err( p_this, "cannot resolve %s port %d : %s", psz_realhost,
 146                  i_realport, gai_strerror( i_val ) );
 147         return -1;
 148     }
 149
 150     int timeout = var_InheritInteger (p_this, "ipv4-timeout");
 151     if (timeout < 0)
 152         timeout = -1;
 153
 154     for( ptr = res; ptr != NULL; ptr = ptr->ai_next )
 155     {
 156         int fd = net_Socket( p_this, ptr->ai_family,
 157                              ptr->ai_socktype, ptr->ai_protocol );
 158         if( fd == -1 )
 159         {
 160             msg_Dbg( p_this, "socket error: %m" );
 161             continue;
 162         }
 163
 164         if( connect( fd, ptr->ai_addr, ptr->ai_addrlen ) )
 165         {
 166             int val;
 167
 168             if( net_errno != EINPROGRESS && net_errno != EINTR )
 169             {
 170                 msg_Err( p_this, "connection failed: %m" );
 171                 goto next_ai;
 172             }
 173
 174             struct pollfd ufd[2] = {
 175                 { .fd = fd,   .events = POLLOUT },
 176                 { .fd = evfd, .events = POLLIN },
 177             };
 178
 179             do
 180                 /* NOTE: timeout screwed up if we catch a signal (EINTR) */
 181                 val = poll (ufd, sizeof (ufd) / sizeof (ufd[0]), timeout);
 182             while ((val == -1) && (net_errno == EINTR));
 183
 184             switch (val)
 185             {
 186                  case -1: /* error */
 187                      msg_Err (p_this, "connection polling error: %m");
 188                      goto next_ai;
 189
 190                  case 0: /* timeout */
 191                      msg_Warn (p_this, "connection timed out");
 192                      goto next_ai;
 193
 194                  default: /* something happended */
 195                      if (ufd[1].revents)
 196                          goto next_ai; /* LibVLC object killed */
 197             }
 198
 199             /* There is NO WAY around checking SO_ERROR.
 200              * Don't ifdef it out!!! */
 201             if (getsockopt (fd, SOL_SOCKET, SO_ERROR, &val,
 202                             &(socklen_t){ sizeof (val) }) || val)
 203             {
 204                 errno = val;
 205                 msg_Err (p_this, "connection failed: %m");
 206                 goto next_ai;
 207             }
 208         }
 209
 210         msg_Dbg( p_this, "connection succeeded (socket = %d)", fd );
 211         i_handle = fd; /* success! */
 212         break;
 213
 214 next_ai: /* failure */
 215         net_Close( fd );
 216         continue;
 217     }
 218
 219     freeaddrinfo( res );
 220
 221     if( i_handle == -1 )
 222         return -1;
 223
 224     if( psz_socks != NULL )
 225     {
 226         /* NOTE: psz_socks already free'd! */
 227         char *psz_user = var_InheritString( p_this, "socks-user" );
 228         char *psz_pwd  = var_InheritString( p_this, "socks-pwd" );
 229
 230         if( SocksHandshakeTCP( p_this, i_handle, 5, psz_user, psz_pwd,
 231                                psz_host, i_port ) )
 232         {
 233             msg_Err( p_this, "SOCKS handshake failed" );
 234             net_Close( i_handle );
 235             i_handle = -1;
 236         }
 237
 238         free( psz_user );
 239         free( psz_pwd );
 240     }
 241
 242     return i_handle;
 243 }
 244
 245
 246 int net_AcceptSingle (vlc_object_t *obj, int lfd)
 247 {
 248     int fd = vlc_accept (lfd, NULL, NULL, true);
 249     if (fd == -1)
 250     {
 251         if (net_errno != EAGAIN && net_errno != EWOULDBLOCK)
 252             msg_Err (obj, "accept failed (from socket %d): %m", lfd);
 253         return -1;
 254     }
 255
 256     msg_Dbg (obj, "accepted socket %d (from socket %d)", fd, lfd);
 257     setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &(int){ 1 }, sizeof(int));
 258     return fd;
 259 }
 260
 261
 262 #undef net_Accept
 263 /**
 264  * Accepts an new connection on a set of listening sockets.
 265  * If there are no pending connections, this function will wait.
 266  * @note If the thread needs to handle events other than incoming connections,
 267  * you need to use poll() and net_AcceptSingle() instead.
 268  *
 269  * @param p_this VLC object for logging and object kill signal
 270  * @param pi_fd listening socket set
 271  * @return -1 on error (may be transient error due to network issues),
 272  * a new socket descriptor on success.
 273  */
 274 int net_Accept (vlc_object_t *p_this, int *pi_fd)
 275 {
 276     int evfd = vlc_object_waitpipe (p_this);
 277
 278     assert (pi_fd != NULL);
 279
 280     unsigned n = 0;
 281     while (pi_fd[n] != -1)
 282         n++;
 283     struct pollfd ufd[n + 1];
 284
 285     /* Initialize file descriptor set */
 286     for (unsigned i = 0; i <= n; i++)
 287     {
 288         ufd[i].fd = (i < n) ? pi_fd[i] : evfd;
 289         ufd[i].events = POLLIN;
 290     }
 291     ufd[n].revents = 0;
 292
 293     for (;;)
 294     {
 295         while (poll (ufd, n + (evfd != -1), -1) == -1)
 296         {
 297             if (net_errno != EINTR)
 298             {
 299                 msg_Err (p_this, "poll error: %m");
 300                 return -1;
 301             }
 302         }
 303
 304         for (unsigned i = 0; i < n; i++)
 305         {
 306             if (ufd[i].revents == 0)
 307                 continue;
 308
 309             int sfd = ufd[i].fd;
 310             int fd = net_AcceptSingle (p_this, sfd);
 311             if (fd == -1)
 312                 continue;
 313
 314             /*
 315              * Move listening socket to the end to let the others in the
 316              * set a chance next time.
 317              */
 318             memmove (pi_fd + i, pi_fd + i + 1, n - (i + 1));
 319             pi_fd[n - 1] = sfd;
 320             return fd;
 321         }
 322
 323         if (ufd[n].revents)
 324         {
 325             errno = EINTR;
 326             break;
 327         }
 328     }
 329     return -1;
 330 }
 331
 332
 333 /*****************************************************************************
 334  * SocksNegotiate:
 335  *****************************************************************************
 336  * Negotiate authentication with a SOCKS server.
 337  *****************************************************************************/
 338 static int SocksNegotiate( vlc_object_t *p_obj,
 339                            int fd, int i_socks_version,
 340                            const char *psz_socks_user,
 341                            const char *psz_socks_passwd )
 342 {
 343     uint8_t buffer[128+2*256];
 344     int i_len;
 345     bool b_auth = false;
 346
 347     if( i_socks_version != 5 )
 348         return VLC_SUCCESS;
 349
 350     /* We negotiate authentication */
 351
 352     if( ( psz_socks_user == NULL ) && ( psz_socks_passwd == NULL ) )
 353         b_auth = true;
 354
 355     buffer[0] = i_socks_version;    /* SOCKS version */
 356     if( b_auth )
 357     {
 358         buffer[1] = 2;                  /* Number of methods */
 359         buffer[2] = 0x00;               /* - No auth required */
 360         buffer[3] = 0x02;               /* - USer/Password */
 361         i_len = 4;
 362     }
 363     else
 364     {
 365         buffer[1] = 1;                  /* Number of methods */
 366         buffer[2] = 0x00;               /* - No auth required */
 367         i_len = 3;
 368     }
 369
 370     if( net_Write( p_obj, fd, NULL, buffer, i_len ) != i_len )
 371         return VLC_EGENERIC;
 372     if( net_Read( p_obj, fd, NULL, buffer, 2, true ) != 2 )
 373         return VLC_EGENERIC;
 374
 375     msg_Dbg( p_obj, "socks: v=%d method=%x", buffer[0], buffer[1] );
 376
 377     if( buffer[1] == 0x00 )
 378     {
 379         msg_Dbg( p_obj, "socks: no authentication required" );
 380     }
 381     else if( buffer[1] == 0x02 )
 382     {
 383         int i_len1 = __MIN( strlen(psz_socks_user), 255 );
 384         int i_len2 = __MIN( strlen(psz_socks_passwd), 255 );
 385         msg_Dbg( p_obj, "socks: username/password authentication" );
 386
 387         /* XXX: we don't support user/pwd > 255 (truncated)*/
 388         buffer[0] = i_socks_version;        /* Version */
 389         buffer[1] = i_len1;                 /* User length */
 390         memcpy( &buffer[2], psz_socks_user, i_len1 );
 391         buffer[2+i_len1] = i_len2;          /* Password length */
 392         memcpy( &buffer[2+i_len1+1], psz_socks_passwd, i_len2 );
 393
 394         i_len = 3 + i_len1 + i_len2;
 395
 396         if( net_Write( p_obj, fd, NULL, buffer, i_len ) != i_len )
 397             return VLC_EGENERIC;
 398
 399         if( net_Read( p_obj, fd, NULL, buffer, 2, true ) != 2 )
 400             return VLC_EGENERIC;
 401
 402         msg_Dbg( p_obj, "socks: v=%d status=%x", buffer[0], buffer[1] );
 403         if( buffer[1] != 0x00 )
 404         {
 405             msg_Err( p_obj, "socks: authentication rejected" );
 406             return VLC_EGENERIC;
 407         }
 408     }
 409     else
 410     {
 411         if( b_auth )
 412             msg_Err( p_obj, "socks: unsupported authentication method %x",
 413                      buffer[0] );
 414         else
 415             msg_Err( p_obj, "socks: authentication needed" );
 416         return VLC_EGENERIC;
 417     }
 418
 419     return VLC_SUCCESS;
 420 }
 421
 422 /*****************************************************************************
 423  * SocksHandshakeTCP:
 424  *****************************************************************************
 425  * Open a TCP connection using a SOCKS server and return a handle (RFC 1928)
 426  *****************************************************************************/
 427 static int SocksHandshakeTCP( vlc_object_t *p_obj,
 428                               int fd,
 429                               int i_socks_version,
 430                               const char *psz_user, const char *psz_passwd,
 431                               const char *psz_host, int i_port )
 432 {
 433     uint8_t buffer[128+2*256];
 434
 435     if( i_socks_version != 4 && i_socks_version != 5 )
 436     {
 437         msg_Warn( p_obj, "invalid socks protocol version %d", i_socks_version );
 438         i_socks_version = 5;
 439     }
 440
 441     if( i_socks_version == 5 &&
 442         SocksNegotiate( p_obj, fd, i_socks_version,
 443                         psz_user, psz_passwd ) )
 444         return VLC_EGENERIC;
 445
 446     if( i_socks_version == 4 )
 447     {
 448         struct addrinfo hints, *p_res;
 449
 450         /* v4 only support ipv4 */
 451         memset (&hints, 0, sizeof (hints));
 452         hints.ai_family = AF_INET;
 453         hints.ai_socktype = SOCK_STREAM;
 454         hints.ai_protocol = IPPROTO_TCP;
 455         if( vlc_getaddrinfo( p_obj, psz_host, 0, &hints, &p_res ) )
 456             return VLC_EGENERIC;
 457
 458         buffer[0] = i_socks_version;
 459         buffer[1] = 0x01;               /* CONNECT */
 460         SetWBE( &buffer[2], i_port );   /* Port */
 461         memcpy( &buffer[4],             /* Address */
 462                 &((struct sockaddr_in *)(p_res->ai_addr))->sin_addr, 4 );
 463         freeaddrinfo( p_res );
 464
 465         buffer[8] = 0;                  /* Empty user id */
 466
 467         if( net_Write( p_obj, fd, NULL, buffer, 9 ) != 9 )
 468             return VLC_EGENERIC;
 469         if( net_Read( p_obj, fd, NULL, buffer, 8, true ) != 8 )
 470             return VLC_EGENERIC;
 471
 472         msg_Dbg( p_obj, "socks: v=%d cd=%d",
 473                  buffer[0], buffer[1] );
 474
 475         if( buffer[1] != 90 )
 476             return VLC_EGENERIC;
 477     }
 478     else if( i_socks_version == 5 )
 479     {
 480         int i_hlen = __MIN(strlen( psz_host ), 255);
 481         int i_len;
 482
 483         buffer[0] = i_socks_version;    /* Version */
 484         buffer[1] = 0x01;               /* Cmd: connect */
 485         buffer[2] = 0x00;               /* Reserved */
 486         buffer[3] = 3;                  /* ATYP: for now domainname */
 487
 488         buffer[4] = i_hlen;
 489         memcpy( &buffer[5], psz_host, i_hlen );
 490         SetWBE( &buffer[5+i_hlen], i_port );
 491
 492         i_len = 5 + i_hlen + 2;
 493
 494
 495         if( net_Write( p_obj, fd, NULL, buffer, i_len ) != i_len )
 496             return VLC_EGENERIC;
 497
 498         /* Read the header */
 499         if( net_Read( p_obj, fd, NULL, buffer, 5, true ) != 5 )
 500             return VLC_EGENERIC;
 501
 502         msg_Dbg( p_obj, "socks: v=%d rep=%d atyp=%d",
 503                  buffer[0], buffer[1], buffer[3] );
 504
 505         if( buffer[1] != 0x00 )
 506         {
 507             msg_Err( p_obj, "socks: CONNECT request failed" );
 508             return VLC_EGENERIC;
 509         }
 510
 511         /* Read the remaining bytes */
 512         if( buffer[3] == 0x01 )
 513             i_len = 4-1 + 2;
 514         else if( buffer[3] == 0x03 )
 515             i_len = buffer[4] + 2;
 516         else if( buffer[3] == 0x04 )
 517             i_len = 16-1+2;
 518         else
 519             return VLC_EGENERIC;
 520
 521         if( net_Read( p_obj, fd, NULL, buffer, i_len, true ) != i_len )
 522             return VLC_EGENERIC;
 523     }
 524
 525     return VLC_SUCCESS;
 526 }
 527
 528 void net_ListenClose( int *pi_fd )
 529 {
 530     if( pi_fd != NULL )
 531     {
 532         int *pi;
 533
 534         for( pi = pi_fd; *pi != -1; pi++ )
 535             net_Close( *pi );
 536         free( pi_fd );
 537     }
 538 }