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 extern int net_Socket( vlc_object_t *p_this, int i_family, int i_socktype,
  61                        int i_protocol );
  62
  63 #undef net_Connect
  64 /*****************************************************************************
  65  * net_Connect:
  66  *****************************************************************************
  67  * Open a network connection.
  68  * @return socket handler or -1 on error.
  69  *****************************************************************************/
  70 int net_Connect( vlc_object_t *p_this, const char *psz_host, int i_port,
  71                  int type, int proto )
  72 {
  73     const char      *psz_realhost;
  74     char            *psz_socks;
  75     int             i_realport, i_handle = -1;
  76
  77     psz_socks = var_InheritString( p_this, "socks" );
  78     if( psz_socks != NULL )
  79     {
  80         char *psz = strchr( psz_socks, ':' );
  81
  82         if( psz )
  83             *psz++ = '\0';
  84
  85         psz_realhost = psz_socks;
  86         i_realport = ( psz != NULL ) ? atoi( psz ) : 1080;
  87
  88         msg_Dbg( p_this, "net: connecting to %s port %d (SOCKS) "
  89                  "for %s port %d", psz_realhost, i_realport,
  90                  psz_host, i_port );
  91
  92         /* We only implement TCP with SOCKS */
  93         switch( type )
  94         {
  95             case 0:
  96                 type = SOCK_STREAM;
  97             case SOCK_STREAM:
  98                 break;
  99             default:
 100                 msg_Err( p_this, "Socket type not supported through SOCKS" );
 101                 free( psz_socks );
 102                 return -1;
 103         }
 104         switch( proto )
 105         {
 106             case 0:
 107                 proto = IPPROTO_TCP;
 108             case IPPROTO_TCP:
 109                 break;
 110             default:
 111                 msg_Err( p_this, "Transport not supported through SOCKS" );
 112                 free( psz_socks );
 113                 return -1;
 114         }
 115     }
 116     else
 117     {
 118         psz_realhost = psz_host;
 119         i_realport = i_port;
 120
 121         msg_Dbg( p_this, "net: connecting to %s port %d", psz_realhost,
 122                  i_realport );
 123     }
 124
 125     struct addrinfo hints = {
 126         .ai_socktype = type,
 127         .ai_protocol = proto,
 128         .ai_flags = AI_NUMERICSERV | AI_IDN,
 129     }, *res;
 130
 131     int val = vlc_getaddrinfo_i11e(psz_realhost, i_realport, &hints, &res);
 132     if (val)
 133     {
 134         msg_Err (p_this, "cannot resolve %s port %d : %s", psz_realhost,
 135                  i_realport, gai_strerror (val));
 136         free( psz_socks );
 137         return -1;
 138     }
 139     free( psz_socks );
 140
 141     mtime_t timeout = var_InheritInteger(p_this, "ipv4-timeout")
 142                       * (CLOCK_FREQ / 1000);
 143
 144     for (struct addrinfo *ptr = res; ptr != NULL; ptr = ptr->ai_next)
 145     {
 146         int fd = net_Socket( p_this, ptr->ai_family,
 147                              ptr->ai_socktype, ptr->ai_protocol );
 148         if( fd == -1 )
 149         {
 150             msg_Dbg( p_this, "socket error: %s", vlc_strerror_c(net_errno) );
 151             continue;
 152         }
 153
 154         if( connect( fd, ptr->ai_addr, ptr->ai_addrlen ) )
 155         {
 156             if( net_errno != EINPROGRESS && errno != EINTR )
 157             {
 158                 msg_Err( p_this, "connection failed: %s",
 159                          vlc_strerror_c(net_errno) );
 160                 goto next_ai;
 161             }
 162
 163             struct pollfd ufd;
 164             mtime_t deadline = VLC_TS_INVALID;
 165
 166             ufd.fd = fd;
 167             ufd.events = POLLOUT;
 168             deadline = mdate() + timeout;
 169
 170             do
 171             {
 172                 mtime_t now = mdate();
 173
 174                 if (vlc_killed())
 175                     goto next_ai;
 176
 177                 if (now > deadline)
 178                     now = deadline;
 179
 180                 val = vlc_poll_i11e(&ufd, 1, (deadline - now) / 1000);
 181             }
 182             while (val == -1 && errno == EINTR);
 183
 184             switch (val)
 185             {
 186                  case -1: /* error */
 187                      msg_Err (p_this, "polling error: %s",
 188                               vlc_strerror_c(net_errno));
 189                      goto next_ai;
 190
 191                  case 0: /* timeout */
 192                      msg_Warn (p_this, "connection timed out");
 193                      goto next_ai;
 194             }
 195
 196             /* There is NO WAY around checking SO_ERROR.
 197              * Don't ifdef it out!!! */
 198             if (getsockopt (fd, SOL_SOCKET, SO_ERROR, &val,
 199                             &(socklen_t){ sizeof (val) }) || val)
 200             {
 201                 msg_Err (p_this, "connection failed: %s",
 202                          vlc_strerror_c(val));
 203                 goto next_ai;
 204             }
 205         }
 206
 207         msg_Dbg( p_this, "connection succeeded (socket = %d)", fd );
 208         i_handle = fd; /* success! */
 209         break;
 210
 211 next_ai: /* failure */
 212         net_Close( fd );
 213     }
 214
 215     freeaddrinfo( res );
 216
 217     if( i_handle == -1 )
 218         return -1;
 219
 220     if( psz_socks != NULL )
 221     {
 222         /* NOTE: psz_socks already free'd! */
 223         char *psz_user = var_InheritString( p_this, "socks-user" );
 224         char *psz_pwd  = var_InheritString( p_this, "socks-pwd" );
 225
 226         if( SocksHandshakeTCP( p_this, i_handle, 5, psz_user, psz_pwd,
 227                                psz_host, i_port ) )
 228         {
 229             msg_Err( p_this, "SOCKS handshake failed" );
 230             net_Close( i_handle );
 231             i_handle = -1;
 232         }
 233
 234         free( psz_user );
 235         free( psz_pwd );
 236     }
 237
 238     return i_handle;
 239 }
 240
 241
 242 int net_AcceptSingle (vlc_object_t *obj, int lfd)
 243 {
 244     int fd = vlc_accept (lfd, NULL, NULL, true);
 245     if (fd == -1)
 246     {
 247         if (net_errno != EAGAIN)
 248 #if (EAGAIN != EWOULDBLOCK)
 249           if (net_errno != EWOULDBLOCK)
 250 #endif
 251             msg_Err (obj, "accept failed (from socket %d): %s", lfd,
 252                      vlc_strerror_c(net_errno));
 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     assert (pi_fd != NULL);
 277
 278     unsigned n = 0;
 279     while (pi_fd[n] != -1)
 280         n++;
 281
 282     struct pollfd ufd[n];
 283     /* Initialize file descriptor set */
 284     for (unsigned i = 0; i < n; i++)
 285     {
 286         ufd[i].fd = pi_fd[i];
 287         ufd[i].events = POLLIN;
 288     }
 289
 290     for (;;)
 291     {
 292         while (poll (ufd, n, -1) == -1)
 293         {
 294             if (net_errno != EINTR)
 295             {
 296                 msg_Err (p_this, "poll error: %s", vlc_strerror_c(net_errno));
 297                 return -1;
 298             }
 299         }
 300
 301         for (unsigned i = 0; i < n; i++)
 302         {
 303             if (ufd[i].revents == 0)
 304                 continue;
 305
 306             int sfd = ufd[i].fd;
 307             int fd = net_AcceptSingle (p_this, sfd);
 308             if (fd == -1)
 309                 continue;
 310
 311             /*
 312              * Move listening socket to the end to let the others in the
 313              * set a chance next time.
 314              */
 315             memmove (pi_fd + i, pi_fd + i + 1, n - (i + 1));
 316             pi_fd[n - 1] = sfd;
 317             return fd;
 318         }
 319     }
 320     return -1;
 321 }
 322
 323
 324 /*****************************************************************************
 325  * SocksNegotiate:
 326  *****************************************************************************
 327  * Negotiate authentication with a SOCKS server.
 328  *****************************************************************************/
 329 static int SocksNegotiate( vlc_object_t *p_obj,
 330                            int fd, int i_socks_version,
 331                            const char *psz_socks_user,
 332                            const char *psz_socks_passwd )
 333 {
 334     uint8_t buffer[128+2*256];
 335     int i_len;
 336     bool b_auth = false;
 337
 338     if( i_socks_version != 5 )
 339         return VLC_SUCCESS;
 340
 341     /* We negotiate authentication */
 342     buffer[0] = i_socks_version;    /* SOCKS version */
 343     if( psz_socks_user != NULL && psz_socks_passwd != NULL )
 344     {
 345         buffer[1] = 2;                  /* Number of methods */
 346         buffer[2] = 0x00;               /* - No auth required */
 347         buffer[3] = 0x02;               /* - USer/Password */
 348         i_len = 4;
 349         b_auth = true;
 350     }
 351     else
 352     {
 353         buffer[1] = 1;                  /* Number of methods */
 354         buffer[2] = 0x00;               /* - No auth required */
 355         i_len = 3;
 356     }
 357
 358     if( net_Write( p_obj, fd, buffer, i_len ) != i_len )
 359         return VLC_EGENERIC;
 360     if( net_Read( p_obj, fd, buffer, 2) != 2 )
 361         return VLC_EGENERIC;
 362
 363     msg_Dbg( p_obj, "socks: v=%d method=%x", buffer[0], buffer[1] );
 364
 365     if( buffer[1] == 0x00 )
 366     {
 367         msg_Dbg( p_obj, "socks: no authentication required" );
 368     }
 369     else if( buffer[1] == 0x02 )
 370     {
 371         if( psz_socks_user == NULL || psz_socks_passwd == NULL )
 372         {
 373             msg_Err( p_obj, "socks: server mandates authentication but "
 374                             "a username and/or password was not supplied" );
 375             return VLC_EGENERIC;
 376         }
 377
 378         int const i_user = strlen( psz_socks_user );
 379         int const i_pasw = strlen( psz_socks_passwd );
 380
 381         if( i_user > 255 || i_pasw > 255 )
 382         {
 383             msg_Err( p_obj, "socks: rejecting username and/or password due to "
 384                             "violation of RFC1929 (longer than 255 bytes)" );
 385             return VLC_EGENERIC;
 386         }
 387
 388         msg_Dbg( p_obj, "socks: username/password authentication" );
 389
 390         buffer[0] = i_socks_version;        /* Version */
 391         buffer[1] = i_user;                 /* User length */
 392         memcpy( &buffer[2], psz_socks_user, i_user );
 393         buffer[2+i_user] = i_pasw;          /* Password length */
 394         memcpy( &buffer[2+i_user+1], psz_socks_passwd, i_pasw );
 395
 396         i_len = 3 + i_user + i_pasw;
 397
 398         if( net_Write( p_obj, fd, buffer, i_len ) != i_len )
 399             return VLC_EGENERIC;
 400
 401         if( net_Read( p_obj, fd, buffer, 2 ) != 2 )
 402             return VLC_EGENERIC;
 403
 404         msg_Dbg( p_obj, "socks: v=%d status=%x", buffer[0], buffer[1] );
 405         if( buffer[1] != 0x00 )
 406         {
 407             msg_Err( p_obj, "socks: authentication rejected" );
 408             return VLC_EGENERIC;
 409         }
 410     }
 411     else
 412     {
 413         if( b_auth )
 414             msg_Err( p_obj, "socks: unsupported authentication method %x",
 415                      buffer[0] );
 416         else
 417             msg_Err( p_obj, "socks: authentication needed" );
 418         return VLC_EGENERIC;
 419     }
 420
 421     return VLC_SUCCESS;
 422 }
 423
 424 /*****************************************************************************
 425  * SocksHandshakeTCP:
 426  *****************************************************************************
 427  * Open a TCP connection using a SOCKS server and return a handle (RFC 1928)
 428  *****************************************************************************/
 429 static int SocksHandshakeTCP( vlc_object_t *p_obj,
 430                               int fd,
 431                               int i_socks_version,
 432                               const char *psz_user, const char *psz_passwd,
 433                               const char *psz_host, int i_port )
 434 {
 435     uint8_t buffer[128+2*256];
 436
 437     if( i_socks_version != 4 && i_socks_version != 5 )
 438     {
 439         msg_Warn( p_obj, "invalid socks protocol version %d", i_socks_version );
 440         i_socks_version = 5;
 441     }
 442
 443     if( i_socks_version == 5 &&
 444         SocksNegotiate( p_obj, fd, i_socks_version,
 445                         psz_user, psz_passwd ) )
 446         return VLC_EGENERIC;
 447
 448     if( i_socks_version == 4 )
 449     {
 450         /* v4 only support ipv4 */
 451         static const struct addrinfo hints = {
 452             .ai_family = AF_INET,
 453             .ai_socktype = SOCK_STREAM,
 454             .ai_protocol = IPPROTO_TCP,
 455             .ai_flags = AI_IDN,
 456         };
 457         struct addrinfo *res;
 458
 459         if (vlc_getaddrinfo_i11e(psz_host, 0, &hints, &res))
 460             return VLC_EGENERIC;
 461
 462         buffer[0] = i_socks_version;
 463         buffer[1] = 0x01;               /* CONNECT */
 464         SetWBE( &buffer[2], i_port );   /* Port */
 465         memcpy (&buffer[4],             /* Address */
 466                 &((struct sockaddr_in *)(res->ai_addr))->sin_addr, 4);
 467         freeaddrinfo (res);
 468
 469         buffer[8] = 0;                  /* Empty user id */
 470
 471         if( net_Write( p_obj, fd, buffer, 9 ) != 9 )
 472             return VLC_EGENERIC;
 473         if( net_Read( p_obj, fd, buffer, 8 ) != 8 )
 474             return VLC_EGENERIC;
 475
 476         msg_Dbg( p_obj, "socks: v=%d cd=%d",
 477                  buffer[0], buffer[1] );
 478
 479         if( buffer[1] != 90 )
 480             return VLC_EGENERIC;
 481     }
 482     else if( i_socks_version == 5 )
 483     {
 484         int i_hlen = __MIN(strlen( psz_host ), 255);
 485         int i_len;
 486
 487         buffer[0] = i_socks_version;    /* Version */
 488         buffer[1] = 0x01;               /* Cmd: connect */
 489         buffer[2] = 0x00;               /* Reserved */
 490         buffer[3] = 3;                  /* ATYP: for now domainname */
 491
 492         buffer[4] = i_hlen;
 493         memcpy( &buffer[5], psz_host, i_hlen );
 494         SetWBE( &buffer[5+i_hlen], i_port );
 495
 496         i_len = 5 + i_hlen + 2;
 497
 498
 499         if( net_Write( p_obj, fd, buffer, i_len ) != i_len )
 500             return VLC_EGENERIC;
 501
 502         /* Read the header */
 503         if( net_Read( p_obj, fd, buffer, 5 ) != 5 )
 504             return VLC_EGENERIC;
 505
 506         msg_Dbg( p_obj, "socks: v=%d rep=%d atyp=%d",
 507                  buffer[0], buffer[1], buffer[3] );
 508
 509         if( buffer[1] != 0x00 )
 510         {
 511             msg_Err( p_obj, "socks: CONNECT request failed" );
 512             return VLC_EGENERIC;
 513         }
 514
 515         /* Read the remaining bytes */
 516         if( buffer[3] == 0x01 )
 517             i_len = 4-1 + 2;
 518         else if( buffer[3] == 0x03 )
 519             i_len = buffer[4] + 2;
 520         else if( buffer[3] == 0x04 )
 521             i_len = 16-1+2;
 522         else
 523             return VLC_EGENERIC;
 524
 525         if( net_Read( p_obj, fd, buffer, i_len ) != i_len )
 526             return VLC_EGENERIC;
 527     }
 528
 529     return VLC_SUCCESS;
 530 }
 531
 532 void net_ListenClose( int *pi_fd )
 533 {
 534     if( pi_fd != NULL )
 535     {
 536         int *pi;
 537
 538         for( pi = pi_fd; *pi != -1; pi++ )
 539             net_Close( *pi );
 540         free( pi_fd );
 541     }
 542 }