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