modules/access/sftp.c

   1 /*****************************************************************************
   2  * sftp.c: SFTP input module
   3  *****************************************************************************
   4  * Copyright (C) 2009 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Rémi Duraffort <ivoire@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h>
  33
  34 #include <assert.h>
  35
  36 #include <vlc_access.h>
  37 #include <vlc_dialog.h>
  38 #include <vlc_network.h>
  39 #include <vlc_url.h>
  40
  41 #include <libssh2.h>
  42 #include <libssh2_sftp.h>
  43
  44
  45 /*****************************************************************************
  46  * Module descriptor
  47  *****************************************************************************/
  48 static int  Open ( vlc_object_t* );
  49 static void Close( vlc_object_t* );
  50
  51 #define USER_TEXT N_("SFTP user name")
  52 #define USER_LONGTEXT N_("User name that will be used for the connection.")
  53 #define PASS_TEXT N_("SFTP password")
  54 #define PASS_LONGTEXT N_("Password that will be used for the connection.")
  55 #define PORT_TEXT N_("SFTP port")
  56 #define PORT_LONGTEXT N_("SFTP port number to use on the server")
  57 #define MTU_TEXT N_("Read size")
  58 #define MTU_LONGTEXT N_("Size of the request for reading access")
  59
  60 vlc_module_begin ()
  61     set_shortname( "SFTP" )
  62     set_description( N_("SFTP input") )
  63     set_capability( "access", 0 )
  64     set_category( CAT_INPUT )
  65     set_subcategory( SUBCAT_INPUT_ACCESS )
  66     add_integer( "sftp-readsize", 8192, MTU_TEXT, MTU_LONGTEXT, true )
  67     add_integer( "sftp-port", 22, PORT_TEXT, PORT_LONGTEXT, true )
  68     add_shortcut( "sftp" )
  69     set_callbacks( Open, Close )
  70 vlc_module_end ()
  71
  72
  73 /*****************************************************************************
  74  * Local prototypes
  75  *****************************************************************************/
  76 static block_t* Block( access_t * );
  77 static int      Seek( access_t *, uint64_t );
  78 static int      Control( access_t *, int, va_list );
  79
  80
  81 struct access_sys_t
  82 {
  83     int i_socket;
  84     LIBSSH2_SESSION* ssh_session;
  85     LIBSSH2_SFTP* sftp_session;
  86     LIBSSH2_SFTP_HANDLE* file;
  87     int i_read_size;
  88 };
  89
  90
  91
  92 /**
  93  * Connect to the sftp server and ask for a file
  94  * @param p_this: the vlc_object
  95  * @return VLC_SUCCESS if everything was fine
  96  */
  97 static int Open( vlc_object_t* p_this )
  98 {
  99     access_t*   p_access = (access_t*)p_this;
 100     access_sys_t* p_sys;
 101     char* psz_username = NULL;
 102     char* psz_password = NULL;
 103     int i_port;
 104     int i_ret;
 105     vlc_url_t url;
 106     size_t i_len;
 107     int i_type;
 108
 109     if( !p_access->psz_location )
 110         return VLC_EGENERIC;
 111
 112     STANDARD_BLOCK_ACCESS_INIT;
 113
 114     /* Parse the URL */
 115     const char* path = p_access->psz_location;
 116     vlc_UrlParse( &url, path, 0 );
 117
 118     /* Check for some parameters */
 119     if( EMPTY_STR( url.psz_host ) )
 120     {
 121         msg_Err( p_access, "You might give a non empty host" );
 122         goto error;
 123     }
 124
 125     /* If the user name is empty, ask the user */
 126     if( !EMPTY_STR( url.psz_username ) && url.psz_password )
 127     {
 128         psz_username = strdup( url.psz_username );
 129         psz_password = strdup( url.psz_password );
 130     }
 131     else
 132     {
 133         dialog_Login( p_access, &psz_username, &psz_password,
 134                       _("SFTP authentication"),
 135                       _("Please enter a valid login and password for the sftp "
 136                         "connexion to %s"), url.psz_host );
 137         if( EMPTY_STR(psz_username) || !psz_password )
 138             goto error;
 139     }
 140
 141     if( url.i_port <= 0 )
 142         i_port = var_InheritInteger( p_access, "sftp-port" );
 143     else
 144         i_port = url.i_port;
 145
 146
 147     /* Connect to the server using a regular socket */
 148     p_sys->i_socket = net_Connect( p_access, url.psz_host, i_port, SOCK_STREAM, 0 );
 149
 150     /* Create the ssh connexion and wait until the server answer */
 151     if( ( p_sys->ssh_session = libssh2_session_init() ) == NULL )
 152         goto error;
 153
 154     while( ( i_ret = libssh2_session_startup( p_sys->ssh_session,
 155                                               p_sys->i_socket ) )
 156            == LIBSSH2_ERROR_EAGAIN );
 157
 158     if( i_ret != 0 )
 159     {
 160         msg_Err( p_access, "Impossible to open the connection to %s:%i", url.psz_host, i_port );
 161         goto error;
 162     }
 163
 164     /* Set the socket in non-blocking mode */
 165     libssh2_session_set_blocking( p_sys->ssh_session, 1 );
 166
 167     /* List the know hosts */
 168     LIBSSH2_KNOWNHOSTS *ssh_knownhosts = libssh2_knownhost_init( p_sys->ssh_session );
 169     if( !ssh_knownhosts )
 170         goto error;
 171
 172     char *psz_home = config_GetUserDir( VLC_HOME_DIR );
 173     char *psz_knownhosts_file;
 174     asprintf( &psz_knownhosts_file, "%s/.ssh/known_hosts", psz_home );
 175     libssh2_knownhost_readfile( ssh_knownhosts, psz_knownhosts_file,
 176                                 LIBSSH2_KNOWNHOST_FILE_OPENSSH );
 177     free( psz_knownhosts_file );
 178     free( psz_home );
 179
 180     const char *fingerprint = libssh2_session_hostkey( p_sys->ssh_session, &i_len, &i_type );
 181     struct libssh2_knownhost *host;
 182     int check = libssh2_knownhost_check( ssh_knownhosts, url.psz_host,
 183                                          fingerprint, i_len,
 184                                          LIBSSH2_KNOWNHOST_TYPE_PLAIN |
 185                                          LIBSSH2_KNOWNHOST_KEYENC_RAW,
 186                                          &host );
 187
 188     libssh2_knownhost_free( ssh_knownhosts );
 189
 190     /* Check that it does match or at least that the host is unkown */
 191     switch(check)
 192     {
 193     case LIBSSH2_KNOWNHOST_CHECK_FAILURE:
 194     case LIBSSH2_KNOWNHOST_CHECK_NOTFOUND:
 195         msg_Dbg( p_access, "Unable to check the remote host" );
 196         break;
 197     case LIBSSH2_KNOWNHOST_CHECK_MATCH:
 198         msg_Dbg( p_access, "Succesfuly matched the host" );
 199         break;
 200     case LIBSSH2_KNOWNHOST_CHECK_MISMATCH:
 201         msg_Err( p_access, "The host does not match !! The remote key changed !!" );
 202         goto error;
 203     }
 204
 205     //TODO: ask for the available auth methods
 206
 207     /* send the login/password */
 208     if( libssh2_userauth_password( p_sys->ssh_session, psz_username, psz_password ) )
 209     {
 210         msg_Err( p_access, "Authentication by password failed" );
 211         goto error;
 212     }
 213
 214     /* Create the sftp session */
 215     p_sys->sftp_session = libssh2_sftp_init( p_sys->ssh_session );
 216
 217     if( !p_sys->sftp_session )
 218     {
 219         msg_Err( p_access, "Unable to initialize the SFTP session" );
 220         goto error;
 221     }
 222
 223     /* Open the given file */
 224     p_sys->file = libssh2_sftp_open( p_sys->sftp_session, url.psz_path, LIBSSH2_FXF_READ, 0 );
 225     if( !p_sys->file )
 226     {
 227         msg_Err( p_access, "Unable to open the remote file %s", url.psz_path );
 228         goto error;
 229     }
 230
 231     /* Get some information */
 232     LIBSSH2_SFTP_ATTRIBUTES attributes;
 233     if( libssh2_sftp_stat( p_sys->sftp_session, url.psz_path, &attributes ) )
 234     {
 235         msg_Err( p_access, "Impossible to get information about the remote file %s", url.psz_path );
 236         goto error;
 237     }
 238     p_access->info.i_size = attributes.filesize;
 239
 240     p_sys->i_read_size = var_InheritInteger( p_access, "sftp-readsize" );
 241
 242     free( psz_password );
 243     free( psz_username );
 244     vlc_UrlClean( &url );
 245     return VLC_SUCCESS;
 246
 247 error:
 248     if( p_sys->ssh_session )
 249         libssh2_session_free( p_sys->ssh_session );
 250     free( psz_password );
 251     free( psz_username );
 252     vlc_UrlClean( &url );
 253     free( p_sys );
 254     return VLC_EGENERIC;
 255 }
 256
 257
 258 /* Close: quit the module */
 259 static void Close( vlc_object_t* p_this )
 260 {
 261     access_t*   p_access = (access_t*)p_this;
 262     access_sys_t* p_sys = p_access->p_sys;
 263
 264     libssh2_sftp_close_handle( p_sys->file );
 265     libssh2_sftp_shutdown( p_sys->sftp_session );
 266
 267     libssh2_session_free( p_sys->ssh_session );
 268     free( p_sys );
 269 }
 270
 271
 272 static block_t* Block( access_t* p_access )
 273 {
 274     if( p_access->info.b_eof )
 275         return NULL;
 276
 277     /* Allocate the buffer we need */
 278     size_t i_len = __MIN( p_access->p_sys->i_read_size, p_access->info.i_size -
 279                                               p_access->info.i_pos );
 280     block_t* p_block = block_New( p_access, i_len );
 281     if( !p_block )
 282         return NULL;
 283
 284     /* Read the specified size */
 285     ssize_t i_ret = libssh2_sftp_read( p_access->p_sys->file, (char*)p_block->p_buffer, i_len );
 286
 287     if( i_ret < 0 )
 288     {
 289         block_Release( p_block );
 290         msg_Err( p_access, "read failed" );
 291         return NULL;
 292     }
 293     else if( i_ret == 0 )
 294     {
 295         p_access->info.b_eof = true;
 296         block_Release( p_block );
 297         return NULL;
 298     }
 299     else
 300     {
 301         p_access->info.i_pos += i_ret;
 302         return p_block;
 303     }
 304 }
 305
 306
 307 static int Seek( access_t* p_access, uint64_t i_pos )
 308 {
 309     p_access->info.i_pos = i_pos;
 310     p_access->info.b_eof = false;
 311
 312     libssh2_sftp_seek( p_access->p_sys->file, i_pos );
 313     return VLC_SUCCESS;
 314 }
 315
 316
 317 static int Control( access_t* p_access, int i_query, va_list args )
 318 {
 319     bool*       pb_bool;
 320     int64_t*    pi_64;
 321
 322     switch( i_query )
 323     {
 324     case ACCESS_CAN_SEEK:
 325         pb_bool = (bool*)va_arg( args, bool* );
 326         *pb_bool = true;
 327         break;
 328
 329     case ACCESS_CAN_FASTSEEK:
 330         pb_bool = (bool*)va_arg( args, bool* );
 331         *pb_bool = false;
 332         break;
 333
 334     case ACCESS_CAN_PAUSE:
 335     case ACCESS_CAN_CONTROL_PACE:
 336         pb_bool = (bool*)va_arg( args, bool* );
 337         *pb_bool = true;
 338         break;
 339
 340     case ACCESS_GET_PTS_DELAY:
 341         pi_64 = (int64_t*)va_arg( args, int64_t* );
 342         *pi_64 = INT64_C(1000)
 343                * var_InheritInteger( p_access, "network-caching" );
 344         break;
 345
 346     case ACCESS_SET_PAUSE_STATE:
 347         break;
 348
 349     case ACCESS_GET_TITLE_INFO:
 350     case ACCESS_SET_TITLE:
 351     case ACCESS_SET_SEEKPOINT:
 352     case ACCESS_SET_PRIVATE_ID_STATE:
 353     case ACCESS_GET_META:
 354     case ACCESS_GET_PRIVATE_ID_STATE:
 355     case ACCESS_GET_CONTENT_TYPE:
 356         return VLC_EGENERIC;
 357
 358     default:
 359         msg_Warn( p_access, "unimplemented query %d in control", i_query );
 360         return VLC_EGENERIC;
 361     }
 362
 363     return VLC_SUCCESS;
 364 }
 365