modules/access/ftp.c

   1 /*****************************************************************************
   2  * ftp.c: FTP input module
   3  *****************************************************************************
   4  * Copyright (C) 2001-2006 the VideoLAN team
   5  * Copyright © 2006 Rémi Denis-Courmont
   6  * $Id$
   7  *
   8  * Authors: Laurent Aimar <fenrir@via.ecp.fr> - original code
   9  *          Rémi Denis-Courmont <rem # videolan.org> - EPSV support
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 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 General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, 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 #include <vlc_plugin.h>
  35
  36 #include <assert.h>
  37
  38 #include <vlc_access.h>
  39 #include <vlc_interface.h>
  40
  41 #include <vlc_network.h>
  42 #include "vlc_url.h"
  43 #include <vlc_sout.h>
  44
  45 #ifndef IPPORT_FTP
  46 # define IPPORT_FTP 21u
  47 #endif
  48
  49 /*****************************************************************************
  50  * Module descriptor
  51  *****************************************************************************/
  52 static int   InOpen ( vlc_object_t * );
  53 static void  InClose( vlc_object_t * );
  54 static int  OutOpen ( vlc_object_t * );
  55 static void OutClose( vlc_object_t * );
  56
  57 #define CACHING_TEXT N_("Caching value in ms")
  58 #define CACHING_LONGTEXT N_( \
  59     "Caching value for FTP streams. This " \
  60     "value should be set in milliseconds." )
  61 #define USER_TEXT N_("FTP user name")
  62 #define USER_LONGTEXT N_("User name that will " \
  63     "be used for the connection.")
  64 #define PASS_TEXT N_("FTP password")
  65 #define PASS_LONGTEXT N_("Password that will be " \
  66     "used for the connection.")
  67 #define ACCOUNT_TEXT N_("FTP account")
  68 #define ACCOUNT_LONGTEXT N_("Account that will be " \
  69     "used for the connection.")
  70
  71 vlc_module_begin();
  72     set_shortname( "FTP" );
  73     set_description( N_("FTP input") );
  74     set_capability( "access", 0 );
  75     set_category( CAT_INPUT );
  76     set_subcategory( SUBCAT_INPUT_ACCESS );
  77     add_integer( "ftp-caching", 2 * DEFAULT_PTS_DELAY / 1000, NULL,
  78                  CACHING_TEXT, CACHING_LONGTEXT, true );
  79     add_string( "ftp-user", "anonymous", NULL, USER_TEXT, USER_LONGTEXT,
  80                 false );
  81     add_string( "ftp-pwd", "anonymous@example.com", NULL, PASS_TEXT,
  82                 PASS_LONGTEXT, false );
  83     add_string( "ftp-account", "anonymous", NULL, ACCOUNT_TEXT,
  84                 ACCOUNT_LONGTEXT, false );
  85     add_shortcut( "ftp" );
  86     set_callbacks( InOpen, InClose );
  87
  88     add_submodule();
  89     set_shortname( "FTP" );
  90     set_description( N_("FTP upload output") );
  91     set_capability( "sout access", 0 );
  92     set_category( CAT_SOUT );
  93     set_subcategory( SUBCAT_SOUT_ACO );
  94     set_callbacks( OutOpen, OutClose );
  95 vlc_module_end();
  96
  97 /*****************************************************************************
  98  * Local prototypes
  99  *****************************************************************************/
 100 static ssize_t Read( access_t *, uint8_t *, size_t );
 101 static ssize_t Write( sout_access_out_t *, block_t * );
 102 static int Seek( access_t *, int64_t );
 103 static int OutSeek( sout_access_out_t *, off_t );
 104 static int Control( access_t *, int, va_list );
 105
 106 struct access_sys_t
 107 {
 108     vlc_url_t  url;
 109
 110     int        fd_cmd;
 111     int        fd_data;
 112
 113     char       sz_epsv_ip[NI_MAXNUMERICHOST];
 114     bool       out;
 115 };
 116 #define GET_OUT_SYS( p_this ) \
 117     ((access_sys_t *)(((sout_access_out_t *)(p_this))->p_sys))
 118
 119 static int ftp_SendCommand( vlc_object_t *, access_sys_t *, const char *, ... );
 120 static int ftp_ReadCommand( vlc_object_t *, access_sys_t *, int *, char ** );
 121 static int ftp_StartStream( vlc_object_t *, access_sys_t *, int64_t );
 122 static int ftp_StopStream ( vlc_object_t *, access_sys_t * );
 123
 124 static int Login( vlc_object_t *p_access, access_sys_t *p_sys )
 125 {
 126     int i_answer;
 127     char *psz;
 128
 129     /* *** Open a TCP connection with server *** */
 130     int fd = p_sys->fd_cmd = net_ConnectTCP( p_access, p_sys->url.psz_host,
 131                                              p_sys->url.i_port );
 132     if( fd == -1 )
 133     {
 134         msg_Err( p_access, "connection failed" );
 135         intf_UserFatal( p_access, false, _("Network interaction failed"),
 136                         _("VLC could not connect with the given server.") );
 137         return -1;
 138     }
 139
 140     while( ftp_ReadCommand( p_access, p_sys, &i_answer, NULL ) == 1 );
 141
 142     if( i_answer / 100 != 2 )
 143     {
 144         msg_Err( p_access, "connection rejected" );
 145         intf_UserFatal( p_access, false, _("Network interaction failed"),
 146                         _("VLC's connection to the given server was rejected.") );
 147         return -1;
 148     }
 149
 150     msg_Dbg( p_access, "connection accepted (%d)", i_answer );
 151
 152     if( p_sys->url.psz_username && *p_sys->url.psz_username )
 153         psz = strdup( p_sys->url.psz_username );
 154     else
 155         psz = var_CreateGetString( p_access, "ftp-user" );
 156     if( !psz )
 157         return -1;
 158
 159     if( ftp_SendCommand( p_access, p_sys, "USER %s", psz ) < 0 ||
 160         ftp_ReadCommand( p_access, p_sys, &i_answer, NULL ) < 0 )
 161     {
 162         free( psz );
 163         return -1;
 164     }
 165     free( psz );
 166
 167     switch( i_answer / 100 )
 168     {
 169         case 2:
 170             msg_Dbg( p_access, "user accepted" );
 171             break;
 172         case 3:
 173             msg_Dbg( p_access, "password needed" );
 174             if( p_sys->url.psz_password && *p_sys->url.psz_password )
 175                 psz = strdup( p_sys->url.psz_password );
 176             else
 177                 psz = var_CreateGetString( p_access, "ftp-pwd" );
 178             if( !psz )
 179                 return -1;
 180
 181             if( ftp_SendCommand( p_access, p_sys, "PASS %s", psz ) < 0 ||
 182                 ftp_ReadCommand( p_access, p_sys, &i_answer, NULL ) < 0 )
 183             {
 184                 free( psz );
 185                 return -1;
 186             }
 187             free( psz );
 188
 189             switch( i_answer / 100 )
 190             {
 191                 case 2:
 192                     msg_Dbg( p_access, "password accepted" );
 193                     break;
 194                 case 3:
 195                     msg_Dbg( p_access, "account needed" );
 196                     psz = var_CreateGetString( p_access, "ftp-account" );
 197                     if( ftp_SendCommand( p_access, p_sys, "ACCT %s",
 198                                          psz ) < 0 ||
 199                         ftp_ReadCommand( p_access, p_sys, &i_answer, NULL ) < 0 )
 200                     {
 201                         free( psz );
 202                         return -1;
 203                     }
 204                     free( psz );
 205
 206                     if( i_answer / 100 != 2 )
 207                     {
 208                         msg_Err( p_access, "account rejected" );
 209                         intf_UserFatal( p_access, false,
 210                                         _("Network interaction failed"),
 211                                         _("Your account was rejected.") );
 212                         return -1;
 213                     }
 214                     msg_Dbg( p_access, "account accepted" );
 215                     break;
 216
 217                 default:
 218                     msg_Err( p_access, "password rejected" );
 219                     intf_UserFatal( p_access, false,
 220                                     _("Network interaction failed"),
 221                                     _("Your password was rejected.") );
 222                     return -1;
 223             }
 224             break;
 225         default:
 226             msg_Err( p_access, "user rejected" );
 227             intf_UserFatal( p_access, false,
 228                         _("Network interaction failed"),
 229                         _("Your connection attempt to the server was rejected.") );
 230             return -1;
 231     }
 232
 233     return 0;
 234 }
 235
 236 static int Connect( vlc_object_t *p_access, access_sys_t *p_sys )
 237 {
 238     if( Login( p_access, p_sys ) < 0 )
 239         return -1;
 240
 241     /* Extended passive mode */
 242     if( ftp_SendCommand( p_access, p_sys, "EPSV ALL" ) < 0 )
 243     {
 244         msg_Err( p_access, "cannot request extended passive mode" );
 245         net_Close( p_sys->fd_cmd );
 246         return -1;
 247     }
 248
 249     if( ftp_ReadCommand( p_access, p_sys, NULL, NULL ) == 2 )
 250     {
 251         if( net_GetPeerAddress( p_sys->fd_cmd, p_sys->sz_epsv_ip, NULL ) )
 252         {
 253             net_Close( p_sys->fd_cmd );
 254             return -1;
 255         }
 256     }
 257     else
 258     {
 259         /* If ESPV ALL fails, we fallback to PASV.
 260          * We have to restart the connection in case there is a NAT that
 261          * understands EPSV ALL in the way, and hence won't allow PASV on
 262          * the initial connection.
 263          */
 264         msg_Info( p_access, "FTP Extended passive mode disabled" );
 265         net_Close( p_sys->fd_cmd );
 266
 267         if( Login( p_access, p_sys ) )
 268         {
 269             net_Close( p_sys->fd_cmd );
 270             return -1;
 271         }
 272     }
 273
 274     /* check binary mode support */
 275     if( ftp_SendCommand( p_access, p_sys, "TYPE I" ) < 0 ||
 276         ftp_ReadCommand( p_access, p_sys, NULL, NULL ) != 2 )
 277     {
 278         msg_Err( p_access, "cannot set binary transfer mode" );
 279         net_Close( p_sys->fd_cmd );
 280         return -1;
 281     }
 282
 283     return 0;
 284 }
 285
 286
 287 static int parseURL( vlc_url_t *url, const char *path )
 288 {
 289     if( path == NULL )
 290         return VLC_EGENERIC;
 291
 292     /* *** Parse URL and get server addr/port and path *** */
 293     while( *path == '/' )
 294         path++;
 295
 296     vlc_UrlParse( url, path, 0 );
 297
 298     if( url->psz_host == NULL || *url->psz_host == '\0' )
 299         return VLC_EGENERIC;
 300
 301     if( url->i_port <= 0 )
 302         url->i_port = IPPORT_FTP; /* default port */
 303
 304     /* FTP URLs are relative to user's default directory (RFC1738)
 305     For absolute path use ftp://foo.bar//usr/local/etc/filename */
 306
 307     if( url->psz_path && *url->psz_path == '/' )
 308         url->psz_path++;
 309
 310     return VLC_SUCCESS;
 311 }
 312
 313
 314 /****************************************************************************
 315  * Open: connect to ftp server and ask for file
 316  ****************************************************************************/
 317 static int InOpen( vlc_object_t *p_this )
 318 {
 319     access_t     *p_access = (access_t*)p_this;
 320     access_sys_t *p_sys;
 321     char         *psz_arg;
 322
 323     /* Init p_access */
 324     STANDARD_READ_ACCESS_INIT
 325     p_sys->fd_data = -1;
 326     p_sys->out = false;
 327
 328     if( parseURL( &p_sys->url, p_access->psz_path ) )
 329         goto exit_error;
 330
 331     if( Connect( p_this, p_sys ) )
 332         goto exit_error;
 333
 334     /* get size */
 335     if( ftp_SendCommand( p_this, p_sys, "SIZE %s", p_sys->url.psz_path ? : "" ) < 0 ||
 336         ftp_ReadCommand( p_this, p_sys, NULL, &psz_arg ) != 2 )
 337     {
 338         msg_Err( p_access, "cannot get file size" );
 339         net_Close( p_sys->fd_cmd );
 340         goto exit_error;
 341     }
 342     p_access->info.i_size = atoll( &psz_arg[4] );
 343     free( psz_arg );
 344     msg_Dbg( p_access, "file size: %"PRId64, p_access->info.i_size );
 345
 346     /* Start the 'stream' */
 347     if( ftp_StartStream( p_this, p_sys, 0 ) < 0 )
 348     {
 349         msg_Err( p_access, "cannot retrieve file" );
 350         net_Close( p_sys->fd_cmd );
 351         goto exit_error;
 352     }
 353
 354     /* Update default_pts to a suitable value for ftp access */
 355     var_Create( p_access, "ftp-caching", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
 356
 357     return VLC_SUCCESS;
 358
 359 exit_error:
 360     vlc_UrlClean( &p_sys->url );
 361     free( p_sys );
 362     return VLC_EGENERIC;
 363 }
 364
 365 static int OutOpen( vlc_object_t *p_this )
 366 {
 367     sout_access_out_t *p_access = (sout_access_out_t *)p_this;
 368     access_sys_t      *p_sys;
 369
 370     p_sys = malloc( sizeof( *p_sys ) );
 371     if( p_sys == NULL )
 372         return VLC_ENOMEM;
 373     memset( p_sys, 0, sizeof( *p_sys ) );
 374
 375     /* Init p_access */
 376     p_sys->fd_data = -1;
 377     p_sys->out = true;
 378
 379     if( parseURL( &p_sys->url, p_access->psz_path ) )
 380         goto exit_error;
 381
 382     if( Connect( p_this, p_sys ) )
 383         goto exit_error;
 384
 385     /* Start the 'stream' */
 386     if( ftp_StartStream( p_this, p_sys, 0 ) < 0 )
 387     {
 388         msg_Err( p_access, "cannot store file" );
 389         net_Close( p_sys->fd_cmd );
 390         goto exit_error;
 391     }
 392
 393     p_access->pf_seek = OutSeek;
 394     p_access->pf_write = Write;
 395     p_access->p_sys = (void *)p_sys;
 396
 397     return VLC_SUCCESS;
 398
 399 exit_error:
 400     vlc_UrlClean( &p_sys->url );
 401     free( p_sys );
 402     return VLC_EGENERIC;
 403 }
 404
 405 /*****************************************************************************
 406  * Close: free unused data structures
 407  *****************************************************************************/
 408 static void Close( vlc_object_t *p_access, access_sys_t *p_sys )
 409 {
 410     msg_Dbg( p_access, "stopping stream" );
 411     ftp_StopStream( p_access, p_sys );
 412
 413     if( ftp_SendCommand( p_access, p_sys, "QUIT" ) < 0 )
 414     {
 415         msg_Warn( p_access, "cannot quit" );
 416     }
 417     else
 418     {
 419         ftp_ReadCommand( p_access, p_sys, NULL, NULL );
 420     }
 421     net_Close( p_sys->fd_cmd );
 422
 423     /* free memory */
 424     vlc_UrlClean( &p_sys->url );
 425     free( p_sys );
 426 }
 427
 428 static void InClose( vlc_object_t *p_this )
 429 {
 430     Close( p_this, ((access_t *)p_this)->p_sys);
 431 }
 432
 433 static void OutClose( vlc_object_t *p_this )
 434 {
 435     Close( p_this, GET_OUT_SYS(p_this));
 436 }
 437
 438
 439 /*****************************************************************************
 440  * Seek: try to go at the right place
 441  *****************************************************************************/
 442 static int _Seek( vlc_object_t *p_access, access_sys_t *p_sys, int64_t i_pos )
 443 {
 444     if( i_pos < 0 )
 445         return VLC_EGENERIC;
 446
 447     msg_Dbg( p_access, "seeking to %"PRId64, i_pos );
 448
 449     ftp_StopStream( (vlc_object_t *)p_access, p_sys );
 450     if( ftp_StartStream( (vlc_object_t *)p_access, p_sys, i_pos ) < 0 )
 451         return VLC_EGENERIC;
 452
 453     return VLC_SUCCESS;
 454 }
 455
 456 static int Seek( access_t *p_access, int64_t i_pos )
 457 {
 458     int val = _Seek( (vlc_object_t *)p_access, p_access->p_sys, i_pos );
 459     if( val )
 460         return val;
 461
 462     p_access->info.b_eof = false;
 463     p_access->info.i_pos = i_pos;
 464
 465     return VLC_SUCCESS;
 466 }
 467
 468 static int OutSeek( sout_access_out_t *p_access, off_t i_pos )
 469 {
 470     return _Seek( (vlc_object_t *)p_access, GET_OUT_SYS( p_access ), i_pos);
 471 }
 472
 473 /*****************************************************************************
 474  * Read:
 475  *****************************************************************************/
 476 static ssize_t Read( access_t *p_access, uint8_t *p_buffer, size_t i_len )
 477 {
 478     access_sys_t *p_sys = p_access->p_sys;
 479     int i_read;
 480
 481     assert( p_sys->fd_data != -1 );
 482     assert( !p_sys->out );
 483
 484     if( p_access->info.b_eof )
 485         return 0;
 486
 487     i_read = net_Read( p_access, p_sys->fd_data, NULL, p_buffer, i_len,
 488                        false );
 489     if( i_read == 0 )
 490         p_access->info.b_eof = true;
 491     else if( i_read > 0 )
 492         p_access->info.i_pos += i_read;
 493
 494     return i_read;
 495 }
 496
 497 /*****************************************************************************
 498  * Write:
 499  *****************************************************************************/
 500 static ssize_t Write( sout_access_out_t *p_access, block_t *p_buffer )
 501 {
 502     access_sys_t *p_sys = GET_OUT_SYS(p_access);
 503     size_t i_write = 0;
 504
 505     assert( p_sys->fd_data != -1 );
 506
 507     while( p_buffer != NULL )
 508     {
 509         block_t *p_next = p_buffer->p_next;;
 510
 511         i_write += net_Write( p_access, p_sys->fd_data, NULL,
 512                               p_buffer->p_buffer, p_buffer->i_buffer );
 513         block_Release( p_buffer );
 514
 515         p_buffer = p_next;
 516     }
 517
 518     return i_write;
 519 }
 520
 521 /*****************************************************************************
 522  * Control:
 523  *****************************************************************************/
 524 static int Control( access_t *p_access, int i_query, va_list args )
 525 {
 526     bool   *pb_bool;
 527     int          *pi_int;
 528     int64_t      *pi_64;
 529     vlc_value_t  val;
 530
 531     switch( i_query )
 532     {
 533         /* */
 534         case ACCESS_CAN_SEEK:
 535             pb_bool = (bool*)va_arg( args, bool* );
 536             *pb_bool = true;
 537             break;
 538         case ACCESS_CAN_FASTSEEK:
 539             pb_bool = (bool*)va_arg( args, bool* );
 540             *pb_bool = false;
 541             break;
 542         case ACCESS_CAN_PAUSE:
 543             pb_bool = (bool*)va_arg( args, bool* );
 544             *pb_bool = true;    /* FIXME */
 545             break;
 546         case ACCESS_CAN_CONTROL_PACE:
 547             pb_bool = (bool*)va_arg( args, bool* );
 548             *pb_bool = true;    /* FIXME */
 549             break;
 550
 551         /* */
 552         case ACCESS_GET_MTU:
 553             pi_int = (int*)va_arg( args, int * );
 554             *pi_int = 0;
 555             break;
 556
 557         case ACCESS_GET_PTS_DELAY:
 558             pi_64 = (int64_t*)va_arg( args, int64_t * );
 559             var_Get( p_access, "ftp-caching", &val );
 560             *pi_64 = (int64_t)var_GetInteger( p_access, "ftp-caching" ) * INT64_C(1000);
 561             break;
 562
 563         /* */
 564         case ACCESS_SET_PAUSE_STATE:
 565             pb_bool = (bool*)va_arg( args, bool* );
 566             if ( !pb_bool )
 567               return Seek( p_access, p_access->info.i_pos );
 568             break;
 569
 570         case ACCESS_GET_TITLE_INFO:
 571         case ACCESS_SET_TITLE:
 572         case ACCESS_SET_SEEKPOINT:
 573         case ACCESS_SET_PRIVATE_ID_STATE:
 574         case ACCESS_GET_CONTENT_TYPE:
 575         case ACCESS_GET_META:
 576             return VLC_EGENERIC;
 577
 578         default:
 579             msg_Warn( p_access, "unimplemented query in control: %d", i_query);
 580             return VLC_EGENERIC;
 581
 582     }
 583     return VLC_SUCCESS;
 584 }
 585
 586 /*****************************************************************************
 587  * ftp_*:
 588  *****************************************************************************/
 589 static int ftp_SendCommand( vlc_object_t *p_access, access_sys_t *p_sys,
 590                             const char *psz_fmt, ... )
 591 {
 592     va_list      args;
 593     char         *psz_cmd;
 594
 595     va_start( args, psz_fmt );
 596     if( vasprintf( &psz_cmd, psz_fmt, args ) == -1 )
 597         return VLC_EGENERIC;
 598
 599     va_end( args );
 600
 601     msg_Dbg( p_access, "ftp_SendCommand:\"%s\"", psz_cmd);
 602
 603     if( net_Printf( VLC_OBJECT(p_access), p_sys->fd_cmd, NULL, "%s\r\n",
 604                     psz_cmd ) < 0 )
 605     {
 606         msg_Err( p_access, "failed to send command" );
 607         return VLC_EGENERIC;
 608     }
 609     return VLC_SUCCESS;
 610 }
 611
 612 /* TODO support this s**t :
 613  RFC 959 allows the client to send certain TELNET strings at any moment,
 614  even in the middle of a request:
 615
 616  * \377\377.
 617  * \377\376x where x is one byte.
 618  * \377\375x where x is one byte. The server is obliged to send \377\374x
 619  *                                immediately after reading x.
 620  * \377\374x where x is one byte.
 621  * \377\373x where x is one byte. The server is obliged to send \377\376x
 622  *                                immediately after reading x.
 623  * \377x for any other byte x.
 624
 625  These strings are not part of the requests, except in the case \377\377,
 626  where the request contains one \377. */
 627 static int ftp_ReadCommand( vlc_object_t *p_access, access_sys_t *p_sys,
 628                             int *pi_answer, char **ppsz_answer )
 629 {
 630     char         *psz_line;
 631     int          i_answer;
 632
 633     psz_line = net_Gets( p_access, p_sys->fd_cmd, NULL );
 634     if( psz_line == NULL || strlen( psz_line ) < 3 )
 635     {
 636         msg_Err( p_access, "cannot get answer" );
 637         free( psz_line );
 638         if( pi_answer ) *pi_answer    = 500;
 639         if( ppsz_answer ) *ppsz_answer  = NULL;
 640         return -1;
 641     }
 642     msg_Dbg( p_access, "answer=%s", psz_line );
 643
 644     if( psz_line[3] == '-' )    /* Multiple response */
 645     {
 646         char end[4];
 647
 648         memcpy( end, psz_line, 3 );
 649         end[3] = ' ';
 650
 651         for( ;; )
 652         {
 653             char *psz_tmp = net_Gets( p_access, p_sys->fd_cmd, NULL );
 654
 655             if( psz_tmp == NULL )   /* Error */
 656                 break;
 657
 658             if( !strncmp( psz_tmp, end, 4 ) )
 659             {
 660                 free( psz_tmp );
 661                 break;
 662             }
 663             free( psz_tmp );
 664         }
 665     }
 666
 667     i_answer = atoi( psz_line );
 668
 669     if( pi_answer ) *pi_answer = i_answer;
 670     if( ppsz_answer )
 671     {
 672         *ppsz_answer = psz_line;
 673     }
 674     else
 675     {
 676         free( psz_line );
 677     }
 678     return( i_answer / 100 );
 679 }
 680
 681 static int ftp_StartStream( vlc_object_t *p_access, access_sys_t *p_sys,
 682                             int64_t i_start )
 683 {
 684     char psz_ipv4[16], *psz_ip = p_sys->sz_epsv_ip;
 685     int  i_answer;
 686     char *psz_arg, *psz_parser;
 687     int  i_port;
 688
 689     assert( p_sys->fd_data == -1 );
 690
 691     if( ( ftp_SendCommand( p_access, p_sys, *psz_ip ? "EPSV" : "PASV" ) < 0 )
 692      || ( ftp_ReadCommand( p_access, p_sys, &i_answer, &psz_arg ) != 2 ) )
 693     {
 694         msg_Err( p_access, "cannot set passive mode" );
 695         return VLC_EGENERIC;
 696     }
 697
 698     psz_parser = strchr( psz_arg, '(' );
 699     if( psz_parser == NULL )
 700     {
 701         free( psz_arg );
 702         msg_Err( p_access, "cannot parse passive mode response" );
 703         return VLC_EGENERIC;
 704     }
 705
 706     if( *psz_ip )
 707     {
 708         char psz_fmt[7] = "(|||%u";
 709         psz_fmt[1] = psz_fmt[2] = psz_fmt[3] = psz_parser[1];
 710
 711         if( sscanf( psz_parser, psz_fmt, &i_port ) < 1 )
 712         {
 713             free( psz_arg );
 714             msg_Err( p_access, "cannot parse passive mode response" );
 715             return VLC_EGENERIC;
 716         }
 717     }
 718     else
 719     {
 720         unsigned a1, a2, a3, a4, p1, p2;
 721
 722         if( ( sscanf( psz_parser, "(%u,%u,%u,%u,%u,%u", &a1, &a2, &a3, &a4,
 723                       &p1, &p2 ) < 6 ) || ( a1 > 255 ) || ( a2 > 255 )
 724          || ( a3 > 255 ) || ( a4 > 255 ) || ( p1 > 255 ) || ( p2 > 255 ) )
 725         {
 726             free( psz_arg );
 727             msg_Err( p_access, "cannot parse passive mode response" );
 728             return VLC_EGENERIC;
 729         }
 730
 731         sprintf( psz_ipv4, "%u.%u.%u.%u", a1, a2, a3, a4 );
 732         psz_ip = psz_ipv4;
 733         i_port = (p1 << 8) | p2;
 734     }
 735     free( psz_arg );
 736
 737     msg_Dbg( p_access, "ip:%s port:%d", psz_ip, i_port );
 738
 739     if( ftp_SendCommand( p_access, p_sys, "TYPE I" ) < 0 ||
 740         ftp_ReadCommand( p_access, p_sys, &i_answer, NULL ) != 2 )
 741     {
 742         msg_Err( p_access, "cannot set binary transfer mode" );
 743         return VLC_EGENERIC;
 744     }
 745
 746     if( i_start > 0 )
 747     {
 748         if( ftp_SendCommand( p_access, p_sys, "REST %"PRIu64, i_start ) < 0 ||
 749             ftp_ReadCommand( p_access, p_sys, &i_answer, NULL ) > 3 )
 750         {
 751             msg_Err( p_access, "cannot set restart offset" );
 752             return VLC_EGENERIC;
 753         }
 754     }
 755
 756     msg_Dbg( p_access, "waiting for data connection..." );
 757     p_sys->fd_data = net_ConnectTCP( p_access, psz_ip, i_port );
 758     if( p_sys->fd_data < 0 )
 759     {
 760         msg_Err( p_access, "failed to connect with server" );
 761         return VLC_EGENERIC;
 762     }
 763     msg_Dbg( p_access, "connection with \"%s:%d\" successful",
 764              psz_ip, i_port );
 765
 766     /* "1xx" message */
 767     if( ftp_SendCommand( p_access, p_sys, "%s %s",
 768                          p_sys->out ? "STOR" : "RETR",
 769                          p_sys->url.psz_path ?: "" ) < 0 ||
 770         ftp_ReadCommand( p_access, p_sys, &i_answer, NULL ) > 2 )
 771     {
 772         msg_Err( p_access, "cannot retrieve file" );
 773         return VLC_EGENERIC;
 774     }
 775
 776     shutdown( p_sys->fd_data, p_sys->out ? SHUT_RD : SHUT_WR );
 777
 778     return VLC_SUCCESS;
 779 }
 780
 781 static int ftp_StopStream ( vlc_object_t *p_access, access_sys_t *p_sys )
 782 {
 783     if( ftp_SendCommand( p_access, p_sys, "ABOR" ) < 0 )
 784     {
 785         msg_Warn( p_access, "cannot abort file" );
 786         if(  p_sys->fd_data > 0 )
 787             net_Close( p_sys->fd_data );
 788         p_sys->fd_data = -1;
 789         return VLC_EGENERIC;
 790     }
 791
 792     if( p_sys->fd_data != -1 )
 793     {
 794         net_Close( p_sys->fd_data );
 795         p_sys->fd_data = -1;
 796         /* Read the final response from RETR/STOR, i.e. 426 or 226 */
 797         ftp_ReadCommand( p_access, p_sys, NULL, NULL );
 798     }
 799     /* Read the response from ABOR, i.e. 226 or 225 */
 800     ftp_ReadCommand( p_access, p_sys, NULL, NULL );
 801
 802     return VLC_SUCCESS;
 803 }