modules/access/sftp.c

   1 /*****************************************************************************
   2  * sftp.c: SFTP input module
   3  *****************************************************************************
   4  * Copyright (C) 2009 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Rémi Duraffort <ivoire@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * 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 PORT_TEXT N_("SFTP port")
  52 #define PORT_LONGTEXT N_("SFTP port number to use on the server")
  53 #define MTU_TEXT N_("Read size")
  54 #define MTU_LONGTEXT N_("Size of the request for reading access")
  55
  56 vlc_module_begin ()
  57     set_shortname( "SFTP" )
  58     set_description( N_("SFTP input") )
  59     set_capability( "access", 0 )
  60     set_category( CAT_INPUT )
  61     set_subcategory( SUBCAT_INPUT_ACCESS )
  62     add_integer( "sftp-readsize", 8192, MTU_TEXT, MTU_LONGTEXT, true )
  63     add_integer( "sftp-port", 22, PORT_TEXT, PORT_LONGTEXT, true )
  64     add_shortcut( "sftp" )
  65     set_callbacks( Open, Close )
  66 vlc_module_end ()
  67
  68
  69 /*****************************************************************************
  70  * Local prototypes
  71  *****************************************************************************/
  72 static block_t* Block( access_t * );
  73 static int      Seek( access_t *, uint64_t );
  74 static int      Control( access_t *, int, va_list );
  75
  76
  77 struct access_sys_t
  78 {
  79     int i_socket;
  80     LIBSSH2_SESSION* ssh_session;
  81     LIBSSH2_SFTP* sftp_session;
  82     LIBSSH2_SFTP_HANDLE* file;
  83     uint64_t filesize;
  84     size_t i_read_size;
  85 };
  86
  87
  88
  89 /**
  90  * Connect to the sftp server and ask for a file
  91  * @param p_this: the vlc_object
  92  * @return VLC_SUCCESS if everything was fine
  93  */
  94 static int Open( vlc_object_t* p_this )
  95 {
  96     access_t*   p_access = (access_t*)p_this;
  97     access_sys_t* p_sys;
  98     char* psz_username = NULL;
  99     char* psz_password = NULL;
 100     int i_port;
 101     int i_ret;
 102     vlc_url_t url;
 103     size_t i_len;
 104     int i_type;
 105
 106     if( !p_access->psz_location )
 107         return VLC_EGENERIC;
 108
 109     STANDARD_BLOCK_ACCESS_INIT;
 110
 111     /* Parse the URL */
 112     const char* path = p_access->psz_location;
 113     vlc_UrlParse( &url, path, 0 );
 114
 115     /* Check for some parameters */
 116     if( EMPTY_STR( url.psz_host ) )
 117     {
 118         msg_Err( p_access, "You might give a non empty host" );
 119         goto error;
 120     }
 121
 122     /* If the user name is empty, ask the user */
 123     if( !EMPTY_STR( url.psz_username ) && url.psz_password )
 124     {
 125         psz_username = strdup( url.psz_username );
 126         psz_password = strdup( url.psz_password );
 127     }
 128     else
 129     {
 130         dialog_Login( p_access, &psz_username, &psz_password,
 131                       _("SFTP authentication"),
 132                       _("Please enter a valid login and password for the sftp "
 133                         "connexion to %s"), url.psz_host );
 134         if( EMPTY_STR(psz_username) || !psz_password )
 135             goto error;
 136     }
 137
 138     if( url.i_port <= 0 )
 139         i_port = var_InheritInteger( p_access, "sftp-port" );
 140     else
 141         i_port = url.i_port;
 142
 143
 144     /* Connect to the server using a regular socket */
 145     p_sys->i_socket = net_Connect( p_access, url.psz_host, i_port, SOCK_STREAM, 0 );
 146
 147     /* Create the ssh connexion and wait until the server answer */
 148     if( ( p_sys->ssh_session = libssh2_session_init() ) == NULL )
 149         goto error;
 150
 151     while( ( i_ret = libssh2_session_startup( p_sys->ssh_session,
 152                                               p_sys->i_socket ) )
 153            == LIBSSH2_ERROR_EAGAIN );
 154
 155     if( i_ret != 0 )
 156     {
 157         msg_Err( p_access, "Impossible to open the connection to %s:%i", url.psz_host, i_port );
 158         goto error;
 159     }
 160
 161     /* Set the socket in non-blocking mode */
 162     libssh2_session_set_blocking( p_sys->ssh_session, 1 );
 163
 164     /* List the know hosts */
 165     LIBSSH2_KNOWNHOSTS *ssh_knownhosts = libssh2_knownhost_init( p_sys->ssh_session );
 166     if( !ssh_knownhosts )
 167         goto error;
 168
 169     char *psz_home = config_GetUserDir( VLC_HOME_DIR );
 170     char *psz_knownhosts_file;
 171     if( asprintf( &psz_knownhosts_file, "%s/.ssh/known_hosts", psz_home ) != -1 )
 172     {
 173         libssh2_knownhost_readfile( ssh_knownhosts, psz_knownhosts_file,
 174                 LIBSSH2_KNOWNHOST_FILE_OPENSSH );
 175         free( psz_knownhosts_file );
 176     }
 177     free( psz_home );
 178
 179     const char *fingerprint = libssh2_session_hostkey( p_sys->ssh_session, &i_len, &i_type );
 180     struct libssh2_knownhost *host;
 181     int check = libssh2_knownhost_check( ssh_knownhosts, url.psz_host,
 182                                          fingerprint, i_len,
 183                                          LIBSSH2_KNOWNHOST_TYPE_PLAIN |
 184                                          LIBSSH2_KNOWNHOST_KEYENC_RAW,
 185                                          &host );
 186
 187     libssh2_knownhost_free( ssh_knownhosts );
 188
 189     /* Check that it does match or at least that the host is unknown */
 190     switch(check)
 191     {
 192     case LIBSSH2_KNOWNHOST_CHECK_FAILURE:
 193     case LIBSSH2_KNOWNHOST_CHECK_NOTFOUND:
 194         msg_Dbg( p_access, "Unable to check the remote host" );
 195         break;
 196     case LIBSSH2_KNOWNHOST_CHECK_MATCH:
 197         msg_Dbg( p_access, "Succesfuly matched the host" );
 198         break;
 199     case LIBSSH2_KNOWNHOST_CHECK_MISMATCH:
 200         msg_Err( p_access, "The host does not match !! The remote key changed !!" );
 201         goto error;
 202     }
 203
 204     //TODO: ask for the available auth methods
 205
 206     /* send the login/password */
 207     if( libssh2_userauth_password( p_sys->ssh_session, psz_username, psz_password ) )
 208     {
 209         msg_Err( p_access, "Authentication by password failed" );
 210         goto error;
 211     }
 212
 213     /* Create the sftp session */
 214     p_sys->sftp_session = libssh2_sftp_init( p_sys->ssh_session );
 215
 216     if( !p_sys->sftp_session )
 217     {
 218         msg_Err( p_access, "Unable to initialize the SFTP session" );
 219         goto error;
 220     }
 221
 222     /* Open the given file */
 223     p_sys->file = libssh2_sftp_open( p_sys->sftp_session, url.psz_path, LIBSSH2_FXF_READ, 0 );
 224     if( !p_sys->file )
 225     {
 226         msg_Err( p_access, "Unable to open the remote file %s", url.psz_path );
 227         goto error;
 228     }
 229
 230     /* Get some information */
 231     LIBSSH2_SFTP_ATTRIBUTES attributes;
 232     if( libssh2_sftp_stat( p_sys->sftp_session, url.psz_path, &attributes ) )
 233     {
 234         msg_Err( p_access, "Impossible to get information about the remote file %s", url.psz_path );
 235         goto error;
 236     }
 237     p_sys->filesize = attributes.filesize;
 238
 239     p_sys->i_read_size = var_InheritInteger( p_access, "sftp-readsize" );
 240
 241     free( psz_password );
 242     free( psz_username );
 243     vlc_UrlClean( &url );
 244     return VLC_SUCCESS;
 245
 246 error:
 247     if( p_sys->ssh_session )
 248         libssh2_session_free( p_sys->ssh_session );
 249     free( psz_password );
 250     free( psz_username );
 251     vlc_UrlClean( &url );
 252     free( p_sys );
 253     return VLC_EGENERIC;
 254 }
 255
 256
 257 /* Close: quit the module */
 258 static void Close( vlc_object_t* p_this )
 259 {
 260     access_t*   p_access = (access_t*)p_this;
 261     access_sys_t* p_sys = p_access->p_sys;
 262
 263     libssh2_sftp_close_handle( p_sys->file );
 264     libssh2_sftp_shutdown( p_sys->sftp_session );
 265
 266     libssh2_session_free( p_sys->ssh_session );
 267     free( p_sys );
 268 }
 269
 270
 271 static block_t* Block( access_t* p_access )
 272 {
 273     access_sys_t *p_sys = p_access->p_sys;
 274
 275     if( p_access->info.b_eof )
 276         return NULL;
 277
 278     /* Allocate the buffer we need */
 279     size_t i_len = __MIN( p_sys->i_read_size,
 280                           p_sys->filesize - p_access->info.i_pos );
 281     block_t* p_block = block_Alloc( i_len );
 282     if( !p_block )
 283         return NULL;
 284
 285     /* Read the specified size */
 286     ssize_t i_ret = libssh2_sftp_read( p_access->p_sys->file, (char*)p_block->p_buffer, i_len );
 287
 288     if( i_ret < 0 )
 289     {
 290         block_Release( p_block );
 291         msg_Err( p_access, "read failed" );
 292         return NULL;
 293     }
 294     else if( i_ret == 0 )
 295     {
 296         p_access->info.b_eof = true;
 297         block_Release( p_block );
 298         return NULL;
 299     }
 300     else
 301     {
 302         p_access->info.i_pos += i_ret;
 303         return p_block;
 304     }
 305 }
 306
 307
 308 static int Seek( access_t* p_access, uint64_t i_pos )
 309 {
 310     p_access->info.i_pos = i_pos;
 311     p_access->info.b_eof = false;
 312
 313     libssh2_sftp_seek( p_access->p_sys->file, i_pos );
 314     return VLC_SUCCESS;
 315 }
 316
 317
 318 static int Control( access_t* p_access, int i_query, va_list args )
 319 {
 320     bool*       pb_bool;
 321     int64_t*    pi_64;
 322
 323     switch( i_query )
 324     {
 325     case ACCESS_CAN_SEEK:
 326         pb_bool = (bool*)va_arg( args, bool* );
 327         *pb_bool = true;
 328         break;
 329
 330     case ACCESS_CAN_FASTSEEK:
 331         pb_bool = (bool*)va_arg( args, bool* );
 332         *pb_bool = false;
 333         break;
 334
 335     case ACCESS_CAN_PAUSE:
 336     case ACCESS_CAN_CONTROL_PACE:
 337         pb_bool = (bool*)va_arg( args, bool* );
 338         *pb_bool = true;
 339         break;
 340
 341     case ACCESS_GET_SIZE:
 342         *va_arg( args, uint64_t * ) = p_access->p_sys->filesize;
 343         break;
 344
 345     case ACCESS_GET_PTS_DELAY:
 346         pi_64 = (int64_t*)va_arg( args, int64_t* );
 347         *pi_64 = INT64_C(1000)
 348                * var_InheritInteger( p_access, "network-caching" );
 349         break;
 350
 351     case ACCESS_SET_PAUSE_STATE:
 352         break;
 353
 354     default:
 355         return VLC_EGENERIC;
 356     }
 357
 358     return VLC_SUCCESS;
 359 }
 360