src/modules/os.c

   1 /*****************************************************************************
   2  * os.c : Low-level dynamic library handling
   3  *****************************************************************************
   4  * Copyright (C) 2001-2007 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Sam Hocevar <sam@zoy.org>
   8  *          Ethan C. Baldridge <BaldridgeE@cadmus.com>
   9  *          Hans-Peter Jansen <hpj@urpla.net>
  10  *          Gildas Bazin <gbazin@videolan.org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 #ifdef HAVE_CONFIG_H
  28 # include "config.h"
  29 #endif
  30
  31 #include <vlc_common.h>
  32 #include <vlc_plugin.h> /* MODULE_SUFFIX */
  33 #include <vlc_charset.h>
  34 #include "libvlc.h"
  35 #include "modules.h"
  36
  37 #include <stdlib.h>                                      /* free(), strtol() */
  38 #include <stdio.h>                                              /* sprintf() */
  39 #include <string.h>                                              /* strdup() */
  40
  41 #include <sys/types.h>
  42
  43 #if !defined(HAVE_DYNAMIC_PLUGINS)
  44     /* no support for plugins */
  45 #elif defined(HAVE_DL_BEOS)
  46 #   if defined(HAVE_IMAGE_H)
  47 #       include <image.h>
  48 #   endif
  49 #elif defined(__APPLE__)
  50 #   include <dlfcn.h>
  51 #elif defined(HAVE_DL_WINDOWS)
  52 #   include <windows.h>
  53 #elif defined(HAVE_DL_DLOPEN)
  54 #   if defined(HAVE_DLFCN_H) /* Linux, BSD, Hurd */
  55 #       include <dlfcn.h>
  56 #   endif
  57 #   if defined(HAVE_SYS_DL_H)
  58 #       include <sys/dl.h>
  59 #   endif
  60 #elif defined(HAVE_DL_SHL_LOAD)
  61 #   if defined(HAVE_DL_H)
  62 #       include <dl.h>
  63 #   endif
  64 #endif
  65 #ifdef HAVE_VALGRIND_VALGRIND_H
  66 # include <valgrind/valgrind.h>
  67 #endif
  68
  69 /*****************************************************************************
  70  * Local prototypes
  71  *****************************************************************************/
  72 #ifdef HAVE_DYNAMIC_PLUGINS
  73 static void *module_Lookup( module_handle_t, const char * );
  74
  75 #if defined(HAVE_DL_WINDOWS)
  76 static char * GetWindowsError  ( void );
  77 #endif
  78
  79 /**
  80  * module Call
  81  *
  82  * Call a symbol given its name and a module structure. The symbol MUST
  83  * refer to a function returning int and taking a module_t* as an argument.
  84  * \param p_module the modules
  85  * \return 0 if it pass and -1 in case of a failure
  86  */
  87 int module_Call( vlc_object_t *obj, module_t *p_module )
  88 {
  89     static const char psz_name[] = "vlc_entry" MODULE_SUFFIX;
  90     int (* pf_symbol) ( module_t * p_module );
  91
  92     /* Try to resolve the symbol */
  93     pf_symbol = (int (*)(module_t *)) module_Lookup( p_module->handle,
  94                                                      psz_name );
  95
  96     if( pf_symbol == NULL )
  97     {
  98 #if defined(HAVE_DL_BEOS)
  99         msg_Warn( obj, "cannot find symbol \"%s\" in file `%s'",
 100                   psz_name, p_module->psz_filename );
 101 #elif defined(HAVE_DL_WINDOWS)
 102         char *psz_error = GetWindowsError();
 103         msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%s)",
 104                   psz_name, p_module->psz_filename, psz_error );
 105         free( psz_error );
 106 #elif defined(HAVE_DL_DLOPEN)
 107         msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%s)",
 108                   psz_name, p_module->psz_filename, dlerror() );
 109 #elif defined(HAVE_DL_SHL_LOAD)
 110         msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%m)",
 111                   psz_name, p_module->psz_filename );
 112 #else
 113 #   error "Something is wrong in modules.c"
 114 #endif
 115         return -1;
 116     }
 117
 118     /* We can now try to call the symbol */
 119     if( pf_symbol( p_module ) != 0 )
 120     {
 121         /* With a well-written module we shouldn't have to print an
 122          * additional error message here, but just make sure. */
 123         msg_Err( obj, "Failed to call symbol \"%s\" in file `%s'",
 124                  psz_name, p_module->psz_filename );
 125         return -1;
 126     }
 127
 128     /* Everything worked fine, we can return */
 129     return 0;
 130 }
 131
 132 /**
 133  * Load a dynamically linked library using a system dependent method.
 134  *
 135  * \param p_this vlc object
 136  * \param psz_file library file
 137  * \param p_handle the module handle returned
 138  * \return 0 on success as well as the module handle.
 139  */
 140 int module_Load( vlc_object_t *p_this, const char *psz_file,
 141                  module_handle_t *p_handle )
 142 {
 143     module_handle_t handle;
 144
 145 #if defined(HAVE_DL_BEOS)
 146     handle = load_add_on( psz_file );
 147     if( handle < 0 )
 148     {
 149         msg_Warn( p_this, "cannot load module `%s'", psz_file );
 150         return -1;
 151     }
 152
 153 #elif defined(HAVE_DL_WINDOWS)
 154     wchar_t psz_wfile[MAX_PATH];
 155     MultiByteToWideChar( CP_UTF8, 0, psz_file, -1, psz_wfile, MAX_PATH );
 156
 157 #ifndef UNDER_CE
 158     /* FIXME: this is not thread-safe -- Courmisch */
 159     UINT mode = SetErrorMode (SEM_FAILCRITICALERRORS);
 160     SetErrorMode (mode|SEM_FAILCRITICALERRORS);
 161 #endif
 162
 163     handle = LoadLibraryW( psz_wfile );
 164
 165 #ifndef UNDER_CE
 166     SetErrorMode (mode);
 167 #endif
 168
 169     if( handle == NULL )
 170     {
 171         char *psz_err = GetWindowsError();
 172         msg_Warn( p_this, "cannot load module `%s' (%s)", psz_file, psz_err );
 173         free( psz_err );
 174         return -1;
 175     }
 176
 177 #elif defined(HAVE_DL_DLOPEN)
 178
 179 # if defined (RTLD_NOW)
 180     const int flags = RTLD_NOW;
 181 # elif defined (DL_LAZY)
 182     const int flags = DL_LAZY;
 183 # else
 184     const int flags = 0;
 185 # endif
 186     char *path = ToLocale( psz_file );
 187
 188     handle = dlopen( path, flags );
 189     if( handle == NULL )
 190     {
 191         msg_Warn( p_this, "cannot load module `%s' (%s)", path, dlerror() );
 192         LocaleFree( path );
 193         return -1;
 194     }
 195     LocaleFree( path );
 196
 197 #elif defined(HAVE_DL_SHL_LOAD)
 198     handle = shl_load( psz_file, BIND_IMMEDIATE | BIND_NONFATAL, NULL );
 199     if( handle == NULL )
 200     {
 201         msg_Warn( p_this, "cannot load module `%s' (%m)", psz_file );
 202         return -1;
 203     }
 204
 205 #else
 206 #   error "Something is wrong in modules.c"
 207
 208 #endif
 209
 210     *p_handle = handle;
 211     return 0;
 212 }
 213
 214 /**
 215  * CloseModule: unload a dynamic library
 216  *
 217  * This function unloads a previously opened dynamically linked library
 218  * using a system dependent method. No return value is taken in consideration,
 219  * since some libraries sometimes refuse to close properly.
 220  * \param handle handle of the library
 221  * \return nothing
 222  */
 223 void module_Unload( module_handle_t handle )
 224 {
 225 #if defined(HAVE_DL_BEOS)
 226     unload_add_on( handle );
 227
 228 #elif defined(HAVE_DL_WINDOWS)
 229     FreeLibrary( handle );
 230
 231 #elif defined(HAVE_DL_DLOPEN)
 232 # ifdef HAVE_VALGRIND_VALGRIND_H
 233     if( RUNNING_ON_VALGRIND > 0 )
 234         return; /* do not dlclose() so that we get proper stack traces */
 235 # endif
 236     dlclose( handle );
 237
 238 #elif defined(HAVE_DL_SHL_LOAD)
 239     shl_unload( handle );
 240
 241 #endif
 242     return;
 243 }
 244
 245 /**
 246  * Looks up a symbol from a dynamically loaded library
 247  *
 248  * This function queries a loaded library for a symbol specified in a
 249  * string, and returns a pointer to it. We don't check for dlerror() or
 250  * similar functions, since we want a non-NULL symbol anyway.
 251  *
 252  * @param handle handle to the module
 253  * @param psz_function function name
 254  * @return NULL on error, or the address of the symbol
 255  */
 256 static void *module_Lookup( module_handle_t handle, const char *psz_function )
 257 {
 258 #if defined(HAVE_DL_BEOS)
 259     void * p_symbol;
 260     if( B_OK == get_image_symbol( handle, psz_function,
 261                                   B_SYMBOL_TYPE_TEXT, &p_symbol ) )
 262     {
 263         return p_symbol;
 264     }
 265     else
 266     {
 267         return NULL;
 268     }
 269
 270 #elif defined(HAVE_DL_WINDOWS) && defined(UNDER_CE)
 271     wchar_t wide[strlen( psz_function ) + 1];
 272     size_t i = 0;
 273     do
 274         wide[i] = psz_function[i]; /* UTF-16 <- ASCII */
 275     while( psz_function[i++] );
 276
 277     return (void *)GetProcAddress( handle, wide );
 278
 279 #elif defined(HAVE_DL_WINDOWS) && defined(WIN32)
 280     return (void *)GetProcAddress( handle, (char *)psz_function );
 281
 282 #elif defined(HAVE_DL_DLOPEN)
 283     return dlsym( handle, psz_function );
 284
 285 #elif defined(HAVE_DL_SHL_LOAD)
 286     void *p_sym;
 287     shl_findsym( &handle, psz_function, TYPE_UNDEFINED, &p_sym );
 288     return p_sym;
 289
 290 #endif
 291 }
 292
 293 #if defined(HAVE_DL_WINDOWS)
 294 static char * GetWindowsError( void )
 295 {
 296 #if defined(UNDER_CE)
 297     wchar_t psz_tmp[MAX_PATH];
 298     char * psz_buffer = malloc( MAX_PATH );
 299 #else
 300     char * psz_tmp = malloc( MAX_PATH );
 301 #endif
 302     int i = 0, i_error = GetLastError();
 303
 304     FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
 305                    NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
 306                    (LPTSTR)psz_tmp, MAX_PATH, NULL );
 307
 308     /* Go to the end of the string */
 309     while( psz_tmp[i] && psz_tmp[i] != _T('\r') && psz_tmp[i] != _T('\n') )
 310     {
 311         i++;
 312     }
 313
 314     if( psz_tmp[i] )
 315     {
 316 #if defined(UNDER_CE)
 317         swprintf( psz_tmp + i, L" (error %i)", i_error );
 318         psz_tmp[ 255 ] = L'\0';
 319 #else
 320         snprintf( psz_tmp + i, 256 - i, " (error %i)", i_error );
 321         psz_tmp[ 255 ] = '\0';
 322 #endif
 323     }
 324
 325 #if defined(UNDER_CE)
 326     wcstombs( psz_buffer, psz_tmp, MAX_PATH );
 327     return psz_buffer;
 328 #else
 329     return psz_tmp;
 330 #endif
 331 }
 332 #endif /* HAVE_DL_WINDOWS */
 333 #endif /* HAVE_DYNAMIC_PLUGINS */