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 #include <limits.h>
  38 #include <unistd.h>
  39 #ifdef HAVE_POLL
  40 # include <poll.h>
  41 #endif
  42
  43 #include <vlc_network.h>
  44 #if defined (_WIN32)
  45 #   undef EINPROGRESS
  46 #   define EINPROGRESS WSAEWOULDBLOCK
  47 #   undef EWOULDBLOCK
  48 #   define EWOULDBLOCK WSAEWOULDBLOCK
  49 #   undef EAGAIN
  50 #   define EAGAIN WSAEWOULDBLOCK
  51 #endif
  52 #include <vlc_interrupt.h>
  53
  54 static int SocksNegotiate( vlc_object_t *, int fd, int i_socks_version,
  55                            const char *psz_user, const char *psz_passwd );
  56 static int SocksHandshakeTCP( vlc_object_t *,
  57                               int fd, int i_socks_version,
  58                               const char *psz_user, const char *psz_passwd,
  59                               const char *psz_host, int i_port );
  60
  61 #undef net_Connect
  62 /*****************************************************************************
  63  * net_Connect:
  64  *****************************************************************************
  65  * Open a network connection.
  66  * @return socket handler or -1 on error.
  67  *****************************************************************************/
  68 int net_Connect( vlc_object_t *p_this, const char *psz_host, int i_port,
  69                  int type, int proto )
  70 {
  71     const char      *psz_realhost;
  72     char            *psz_socks;
  73     int             i_realport, i_handle = -1;
  74
  75     psz_socks = var_InheritString( p_this, "socks" );
  76     if( psz_socks != NULL )
  77     {
  78         char *psz = strchr( psz_socks, ':' );
  79
  80         if( psz )
  81             *psz++ = '\0';
  82
  83         psz_realhost = psz_socks;
  84         i_realport = ( psz != NULL ) ? atoi( psz ) : 1080;
  85
  86         msg_Dbg( p_this, "net: connecting to %s port %d (SOCKS) "
  87                  "for %s port %d", psz_realhost, i_realport,
  88                  psz_host, i_port );
  89
  90         /* We only implement TCP with SOCKS */
  91         switch( type )
  92         {
  93             case 0:
  94                 type = SOCK_STREAM;
  95             case SOCK_STREAM:
  96                 break;
  97             default:
  98                 msg_Err( p_this, "Socket type not supported through SOCKS" );
  99                 free( psz_socks );
 100                 return -1;
 101         }
 102         switch( proto )
 103         {
 104             case 0:
 105                 proto = IPPROTO_TCP;
 106             case IPPROTO_TCP:
 107                 break;
 108             default:
 109                 msg_Err( p_this, "Transport not supported through SOCKS" );
 110                 free( psz_socks );
 111                 return -1;
 112         }
 113     }
 114     else
 115     {
 116         psz_realhost = psz_host;
 117         i_realport = i_port;
 118
 119         msg_Dbg( p_this, "net: connecting to %s port %d", psz_realhost,
 120                  i_realport );
 121     }
 122
 123     struct addrinfo hints = {
 124         .ai_socktype = type,
 125         .ai_protocol = proto,
 126         .ai_flags = AI_NUMERICSERV | AI_IDN,
 127     }, *res;
 128
 129     int val = vlc_getaddrinfo_i11e(psz_realhost, i_realport, &hints, &res);
 130     if (val)
 131     {
 132         msg_Err (p_this, "cannot resolve %s port %d : %s", psz_realhost,
 133                  i_realport, gai_strerror (val));
 134         free( psz_socks );
 135         return -1;
 136     }
 137     free( psz_socks );
 138
 139     vlc_tick_t timeout = VLC_TICK_FROM_MS( var_InheritInteger(p_this, "ipv4-timeout") );
 140
 141     for (struct addrinfo *ptr = res; ptr != NULL; ptr = ptr->ai_next)
 142     {
 143         int fd = net_Socket( p_this, ptr->ai_family,
 144                              ptr->ai_socktype, ptr->ai_protocol );
 145         if( fd == -1 )
 146         {
 147             msg_Dbg( p_this, "socket error: %s", vlc_strerror_c(net_errno) );
 148             continue;
 149         }
 150
 151         if( connect( fd, ptr->ai_addr, ptr->ai_addrlen ) )
 152         {
 153             if( net_errno != EINPROGRESS && errno != EINTR )
 154             {
 155                 msg_Err( p_this, "connection failed: %s",
 156                          vlc_strerror_c(net_errno) );
 157                 goto next_ai;
 158             }
 159
 160             struct pollfd ufd;
 161             vlc_tick_t deadline = VLC_TICK_INVALID;
 162
 163             ufd.fd = fd;
 164             ufd.events = POLLOUT;
 165             deadline = vlc_tick_now() + timeout;
 166
 167             do
 168             {
 169                 vlc_tick_t now = vlc_tick_now();
 170
 171                 if (vlc_killed())
 172                     goto next_ai;
 173
 174                 if (now > deadline)
 175                     now = deadline;
 176
 177                 val = vlc_poll_i11e(&ufd, 1, MS_FROM_VLC_TICK(deadline - now));
 178             }
 179             while (val == -1 && errno == EINTR);
 180
 181             switch (val)
 182             {
 183                  case -1: /* error */
 184                      msg_Err (p_this, "polling error: %s",
 185                               vlc_strerror_c(net_errno));
 186                      goto next_ai;
 187
 188                  case 0: /* timeout */
 189                      msg_Warn (p_this, "connection timed out");
 190                      goto next_ai;
 191             }
 192
 193             /* There is NO WAY around checking SO_ERROR.
 194              * Don't ifdef it out!!! */
 195             if (getsockopt (fd, SOL_SOCKET, SO_ERROR, &val,
 196                             &(socklen_t){ sizeof (val) }) || val)
 197             {
 198                 msg_Err (p_this, "connection failed: %s",
 199                          vlc_strerror_c(val));
 200                 goto next_ai;
 201             }
 202         }
 203
 204         msg_Dbg( p_this, "connection succeeded (socket = %d)", fd );
 205         i_handle = fd; /* success! */
 206         break;
 207
 208 next_ai: /* failure */
 209         net_Close( fd );
 210     }
 211
 212     freeaddrinfo( res );
 213
 214     if( i_handle == -1 )
 215         return -1;
 216
 217     if( psz_socks != NULL )
 218     {
 219         /* NOTE: psz_socks already free'd! */
 220         char *psz_user = var_InheritString( p_this, "socks-user" );
 221         char *psz_pwd  = var_InheritString( p_this, "socks-pwd" );
 222
 223         if( SocksHandshakeTCP( p_this, i_handle, 5, psz_user, psz_pwd,
 224                                psz_host, i_port ) )
 225         {
 226             msg_Err( p_this, "SOCKS handshake failed" );
 227             net_Close( i_handle );
 228             i_handle = -1;
 229         }
 230
 231         free( psz_user );
 232         free( psz_pwd );
 233     }
 234
 235     return i_handle;
 236 }
 237
 238
 239 int net_AcceptSingle (vlc_object_t *obj, int lfd)
 240 {
 241     int fd = vlc_accept (lfd, NULL, NULL, true);
 242     if (fd == -1)
 243     {
 244         if (net_errno != EAGAIN)
 245 #if (EAGAIN != EWOULDBLOCK)
 246           if (net_errno != EWOULDBLOCK)
 247 #endif
 248             msg_Err (obj, "accept failed (from socket %d): %s", lfd,
 249                      vlc_strerror_c(net_errno));
 250         return -1;
 251     }
 252
 253     msg_Dbg (obj, "accepted socket %d (from socket %d)", fd, lfd);
 254     setsockopt (fd, SOL_SOCKET, SO_REUSEADDR, &(int){ 1 }, sizeof(int));
 255     return fd;
 256 }
 257
 258
 259 #undef net_Accept
 260 /**
 261  * Accepts an new connection on a set of listening sockets.
 262  * If there are no pending connections, this function will wait.
 263  * @note If the thread needs to handle events other than incoming connections,
 264  * you need to use poll() and net_AcceptSingle() instead.
 265  *
 266  * @param p_this VLC object for logging and object kill signal
 267  * @param pi_fd listening socket set
 268  * @return -1 on error (may be transient error due to network issues),
 269  * a new socket descriptor on success.
 270  */
 271 int net_Accept (vlc_object_t *p_this, int *pi_fd)
 272 {
 273     assert (pi_fd != NULL);
 274
 275     unsigned n = 0;
 276     while (pi_fd[n] != -1)
 277         n++;
 278
 279     struct pollfd ufd[n];
 280     /* Initialize file descriptor set */
 281     for (unsigned i = 0; i < n; i++)
 282     {
 283         ufd[i].fd = pi_fd[i];
 284         ufd[i].events = POLLIN;
 285     }
 286
 287     for (;;)
 288     {
 289         while (poll (ufd, n, -1) == -1)
 290         {
 291             if (net_errno != EINTR)
 292             {
 293                 msg_Err (p_this, "poll error: %s", vlc_strerror_c(net_errno));
 294                 return -1;
 295             }
 296         }
 297
 298         for (unsigned i = 0; i < n; i++)
 299         {
 300             if (ufd[i].revents == 0)
 301                 continue;
 302
 303             int sfd = ufd[i].fd;
 304             int fd = net_AcceptSingle (p_this, sfd);
 305             if (fd == -1)
 306                 continue;
 307
 308             /*
 309              * Move listening socket to the end to let the others in the
 310              * set a chance next time.
 311              */
 312             memmove (pi_fd + i, pi_fd + i + 1, n - (i + 1));
 313             pi_fd[n - 1] = sfd;
 314             return fd;
 315         }
 316     }
 317     return -1;
 318 }
 319
 320
 321 /*****************************************************************************
 322  * SocksNegotiate:
 323  *****************************************************************************
 324  * Negotiate authentication with a SOCKS server.
 325  *****************************************************************************/
 326 static int SocksNegotiate( vlc_object_t *p_obj,
 327                            int fd, int i_socks_version,
 328                            const char *psz_socks_user,
 329                            const char *psz_socks_passwd )
 330 {
 331     uint8_t buffer[128+2*256];
 332     int i_len;
 333     bool b_auth = false;
 334
 335     if( i_socks_version != 5 )
 336         return VLC_SUCCESS;
 337
 338     /* We negotiate authentication */
 339     buffer[0] = i_socks_version;    /* SOCKS version */
 340     if( psz_socks_user != NULL && psz_socks_passwd != NULL )
 341     {
 342         buffer[1] = 2;                  /* Number of methods */
 343         buffer[2] = 0x00;               /* - No auth required */
 344         buffer[3] = 0x02;               /* - USer/Password */
 345         i_len = 4;
 346         b_auth = true;
 347     }
 348     else
 349     {
 350         buffer[1] = 1;                  /* Number of methods */
 351         buffer[2] = 0x00;               /* - No auth required */
 352         i_len = 3;
 353     }
 354
 355     if( net_Write( p_obj, fd, buffer, i_len ) != i_len )
 356         return VLC_EGENERIC;
 357     if( net_Read( p_obj, fd, buffer, 2) != 2 )
 358         return VLC_EGENERIC;
 359
 360     msg_Dbg( p_obj, "socks: v=%d method=%x", buffer[0], buffer[1] );
 361
 362     if( buffer[1] == 0x00 )
 363     {
 364         msg_Dbg( p_obj, "socks: no authentication required" );
 365     }
 366     else if( buffer[1] == 0x02 )
 367     {
 368         if( psz_socks_user == NULL || psz_socks_passwd == NULL )
 369         {
 370             msg_Err( p_obj, "socks: server mandates authentication but "
 371                             "a username and/or password was not supplied" );
 372             return VLC_EGENERIC;
 373         }
 374
 375         int const i_user = strlen( psz_socks_user );
 376         int const i_pasw = strlen( psz_socks_passwd );
 377
 378         if( i_user > 255 || i_pasw > 255 )
 379         {
 380             msg_Err( p_obj, "socks: rejecting username and/or password due to "
 381                             "violation of RFC1929 (longer than 255 bytes)" );
 382             return VLC_EGENERIC;
 383         }
 384
 385         msg_Dbg( p_obj, "socks: username/password authentication" );
 386
 387         buffer[0] = i_socks_version;        /* Version */
 388         buffer[1] = i_user;                 /* User length */
 389         memcpy( &buffer[2], psz_socks_user, i_user );
 390         buffer[2+i_user] = i_pasw;          /* Password length */
 391         memcpy( &buffer[2+i_user+1], psz_socks_passwd, i_pasw );
 392
 393         i_len = 3 + i_user + i_pasw;
 394
 395         if( net_Write( p_obj, fd, buffer, i_len ) != i_len )
 396             return VLC_EGENERIC;
 397
 398         if( net_Read( p_obj, fd, buffer, 2 ) != 2 )
 399             return VLC_EGENERIC;
 400
 401         msg_Dbg( p_obj, "socks: v=%d status=%x", buffer[0], buffer[1] );
 402         if( buffer[1] != 0x00 )
 403         {
 404             msg_Err( p_obj, "socks: authentication rejected" );
 405             return VLC_EGENERIC;
 406         }
 407     }
 408     else
 409     {
 410         if( b_auth )
 411             msg_Err( p_obj, "socks: unsupported authentication method %x",
 412                      buffer[0] );
 413         else
 414             msg_Err( p_obj, "socks: authentication needed" );
 415         return VLC_EGENERIC;
 416     }
 417
 418     return VLC_SUCCESS;
 419 }
 420
 421 /*****************************************************************************
 422  * SocksHandshakeTCP:
 423  *****************************************************************************
 424  * Open a TCP connection using a SOCKS server and return a handle (RFC 1928)
 425  *****************************************************************************/
 426 static int SocksHandshakeTCP( vlc_object_t *p_obj,
 427                               int fd,
 428                               int i_socks_version,
 429                               const char *psz_user, const char *psz_passwd,
 430                               const char *psz_host, int i_port )
 431 {
 432     uint8_t buffer[128+2*256];
 433
 434     if( i_socks_version != 4 && i_socks_version != 5 )
 435     {
 436         msg_Warn( p_obj, "invalid socks protocol version %d", i_socks_version );
 437         i_socks_version = 5;
 438     }
 439
 440     if( i_socks_version == 5 &&
 441         SocksNegotiate( p_obj, fd, i_socks_version,
 442                         psz_user, psz_passwd ) )
 443         return VLC_EGENERIC;
 444
 445     if( i_socks_version == 4 )
 446     {
 447         /* v4 only support ipv4 */
 448         static const struct addrinfo hints = {
 449             .ai_family = AF_INET,
 450             .ai_socktype = SOCK_STREAM,
 451             .ai_protocol = IPPROTO_TCP,
 452             .ai_flags = AI_IDN,
 453         };
 454         struct addrinfo *res;
 455
 456         if (vlc_getaddrinfo_i11e(psz_host, 0, &hints, &res))
 457             return VLC_EGENERIC;
 458
 459         buffer[0] = i_socks_version;
 460         buffer[1] = 0x01;               /* CONNECT */
 461         SetWBE( &buffer[2], i_port );   /* Port */
 462         memcpy (&buffer[4],             /* Address */
 463                 &((struct sockaddr_in *)(res->ai_addr))->sin_addr, 4);
 464         freeaddrinfo (res);
 465
 466         buffer[8] = 0;                  /* Empty user id */
 467
 468         if( net_Write( p_obj, fd, buffer, 9 ) != 9 )
 469             return VLC_EGENERIC;
 470         if( net_Read( p_obj, fd, buffer, 8 ) != 8 )
 471             return VLC_EGENERIC;
 472
 473         msg_Dbg( p_obj, "socks: v=%d cd=%d",
 474                  buffer[0], buffer[1] );
 475
 476         if( buffer[1] != 90 )
 477             return VLC_EGENERIC;
 478     }
 479     else if( i_socks_version == 5 )
 480     {
 481         int i_hlen = __MIN(strlen( psz_host ), 255);
 482         int i_len;
 483
 484         buffer[0] = i_socks_version;    /* Version */
 485         buffer[1] = 0x01;               /* Cmd: connect */
 486         buffer[2] = 0x00;               /* Reserved */
 487         buffer[3] = 3;                  /* ATYP: for now domainname */
 488
 489         buffer[4] = i_hlen;
 490         memcpy( &buffer[5], psz_host, i_hlen );
 491         SetWBE( &buffer[5+i_hlen], i_port );
 492
 493         i_len = 5 + i_hlen + 2;
 494
 495
 496         if( net_Write( p_obj, fd, buffer, i_len ) != i_len )
 497             return VLC_EGENERIC;
 498
 499         /* Read the header */
 500         if( net_Read( p_obj, fd, buffer, 5 ) != 5 )
 501             return VLC_EGENERIC;
 502
 503         msg_Dbg( p_obj, "socks: v=%d rep=%d atyp=%d",
 504                  buffer[0], buffer[1], buffer[3] );
 505
 506         if( buffer[1] != 0x00 )
 507         {
 508             msg_Err( p_obj, "socks: CONNECT request failed" );
 509             return VLC_EGENERIC;
 510         }
 511
 512         /* Read the remaining bytes */
 513         if( buffer[3] == 0x01 )
 514             i_len = 4-1 + 2;
 515         else if( buffer[3] == 0x03 )
 516             i_len = buffer[4] + 2;
 517         else if( buffer[3] == 0x04 )
 518             i_len = 16-1+2;
 519         else
 520             return VLC_EGENERIC;
 521
 522         if( net_Read( p_obj, fd, buffer, i_len ) != i_len )
 523             return VLC_EGENERIC;
 524     }
 525
 526     return VLC_SUCCESS;
 527 }
 528
 529 void net_ListenClose( int *pi_fd )
 530 {
 531     if( pi_fd != NULL )
 532     {
 533         int *pi;
 534
 535         for( pi = pi_fd; *pi != -1; pi++ )
 536             net_Close( *pi );
 537         free( pi_fd );
 538     }
 539 }