1 /*****************************************************************************
2 * os.c : Low-level dynamic library handling
3 *****************************************************************************
4 * Copyright (C) 2001-2007 the VideoLAN team
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>
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.
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.
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 *****************************************************************************/
31 #include <vlc_common.h>
32 #include <vlc_plugin.h> /* MODULE_SUFFIX */
36 #include <stdlib.h> /* free(), strtol() */
37 #include <stdio.h> /* sprintf() */
38 #include <string.h> /* strdup() */
40 #ifdef HAVE_SYS_TYPES_H
41 # include <sys/types.h>
44 #if !defined(HAVE_DYNAMIC_PLUGINS)
45 /* no support for plugins */
46 #elif defined(HAVE_DL_DYLD)
47 # if defined(HAVE_MACH_O_DYLD_H)
48 # include <mach-o/dyld.h>
50 #elif defined(HAVE_DL_BEOS)
51 # if defined(HAVE_IMAGE_H)
54 #elif defined(HAVE_DL_WINDOWS)
56 #elif defined(HAVE_DL_DLOPEN)
57 # if defined(HAVE_DLFCN_H) /* Linux, BSD, Hurd */
60 # if defined(HAVE_SYS_DL_H)
63 #elif defined(HAVE_DL_SHL_LOAD)
64 # if defined(HAVE_DL_H)
69 /*****************************************************************************
71 *****************************************************************************/
72 #ifdef HAVE_DYNAMIC_PLUGINS
73 static void *module_Lookup( module_handle_t, const char * );
75 #if defined(HAVE_DL_WINDOWS)
76 static char * GetWindowsError ( void );
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
87 int module_Call( vlc_object_t *obj, module_t *p_module )
89 static const char psz_name[] = "vlc_entry" MODULE_SUFFIX;
90 int (* pf_symbol) ( module_t * p_module );
92 /* Try to resolve the symbol */
93 pf_symbol = (int (*)(module_t *)) module_Lookup( p_module->handle,
96 if( pf_symbol == NULL )
98 #if defined(HAVE_DL_DYLD) || 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 );
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 );
113 # error "Something is wrong in modules.c"
118 /* We can now try to call the symbol */
119 if( pf_symbol( p_module ) != 0 )
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 );
128 /* Everything worked fine, we can return */
132 #if defined (RTLD_NOLOAD)
133 /* Make sure libvlccore is in the global namespace */
134 static void load_libvlccore( void )
136 if( !dlsym( RTLD_DEFAULT, "libvlc_Quit" )
137 && !dlopen( "libvlccore.so", RTLD_GLOBAL|RTLD_NOLOAD ) )
138 fprintf( stderr, "ERROR: failed loading libvlccore\n" );
143 * Load a dynamically linked library using a system dependent method.
145 * \param p_this vlc object
146 * \param psz_file library file
147 * \param p_handle the module handle returned
148 * \return 0 on success as well as the module handle.
150 int module_Load( vlc_object_t *p_this, const char *psz_file,
151 module_handle_t *p_handle )
153 module_handle_t handle;
155 #if defined(HAVE_DL_DYLD)
156 NSObjectFileImage image;
157 NSObjectFileImageReturnCode ret;
159 ret = NSCreateObjectFileImageFromFile( psz_file, &image );
161 if( ret != NSObjectFileImageSuccess )
163 msg_Warn( p_this, "cannot create image from `%s'", psz_file );
167 /* Open the dynamic module */
168 handle = NSLinkModule( image, psz_file,
169 NSLINKMODULE_OPTION_RETURN_ON_ERROR );
173 NSLinkEditErrors errors;
174 const char *psz_file, *psz_err;
176 NSLinkEditError( &errors, &i_errnum, &psz_file, &psz_err );
177 msg_Warn( p_this, "cannot link module `%s' (%s)", psz_file, psz_err );
178 NSDestroyObjectFileImage( image );
182 /* Destroy our image, we won't need it */
183 NSDestroyObjectFileImage( image );
185 #elif defined(HAVE_DL_BEOS)
186 handle = load_add_on( psz_file );
189 msg_Warn( p_this, "cannot load module `%s'", psz_file );
193 #elif defined(HAVE_DL_WINDOWS)
194 wchar_t psz_wfile[MAX_PATH];
195 MultiByteToWideChar( CP_ACP, 0, psz_file, -1, psz_wfile, MAX_PATH );
198 /* FIXME: this is not thread-safe -- Courmisch */
199 UINT mode = SetErrorMode (SEM_FAILCRITICALERRORS);
200 SetErrorMode (mode|SEM_FAILCRITICALERRORS);
203 handle = LoadLibraryW( psz_wfile );
211 char *psz_err = GetWindowsError();
212 msg_Warn( p_this, "cannot load module `%s' (%s)", psz_file, psz_err );
217 #elif defined(HAVE_DL_DLOPEN)
218 # if defined (RTLD_NOLOAD)
219 static pthread_once_t once = PTHREAD_ONCE_INIT;
220 pthread_once( &once, &load_libvlccore );
223 # if defined (RTLD_NOW)
224 const int flags = RTLD_NOW;
225 # elif defined (DL_LAZY)
226 const int flags = DL_LAZY;
231 handle = dlopen( psz_file, flags );
234 msg_Warn( p_this, "cannot load module `%s' (%s)",
235 psz_file, dlerror() );
239 #elif defined(HAVE_DL_SHL_LOAD)
240 handle = shl_load( psz_file, BIND_IMMEDIATE | BIND_NONFATAL, NULL );
243 msg_Warn( p_this, "cannot load module `%s' (%m)", psz_file );
248 # error "Something is wrong in modules.c"
257 * CloseModule: unload a dynamic library
259 * This function unloads a previously opened dynamically linked library
260 * using a system dependent method. No return value is taken in consideration,
261 * since some libraries sometimes refuse to close properly.
262 * \param handle handle of the library
265 void module_Unload( module_handle_t handle )
267 #if defined(HAVE_DL_DYLD)
268 NSUnLinkModule( handle, FALSE );
270 #elif defined(HAVE_DL_BEOS)
271 unload_add_on( handle );
273 #elif defined(HAVE_DL_WINDOWS)
274 FreeLibrary( handle );
276 #elif defined(HAVE_DL_DLOPEN)
283 #elif defined(HAVE_DL_SHL_LOAD)
284 shl_unload( handle );
291 * Looks up a symbol from a dynamically loaded library
293 * This function queries a loaded library for a symbol specified in a
294 * string, and returns a pointer to it. We don't check for dlerror() or
295 * similar functions, since we want a non-NULL symbol anyway.
297 * @param handle handle to the module
298 * @param psz_function function name
299 * @return NULL on error, or the address of the symbol
301 static void *module_Lookup( module_handle_t handle, const char *psz_function )
303 #if defined(HAVE_DL_DYLD)
304 char psz_call[strlen( psz_function ) + 2];
306 memcpy( psz_call + 1, psz_function, sizeof( psz_call ) - 1 );
308 NSSymbol sym = NSLookupSymbolInModule( handle, psz_call );
309 return NSAddressOfSymbol( sym );
311 #elif defined(HAVE_DL_BEOS)
313 if( B_OK == get_image_symbol( handle, psz_function,
314 B_SYMBOL_TYPE_TEXT, &p_symbol ) )
323 #elif defined(HAVE_DL_WINDOWS) && defined(UNDER_CE)
324 wchar_t wide[strlen( psz_function ) + 1];
327 wide[i] = psz_function[i]; /* UTF-16 <- ASCII */
328 while( psz_function[i++] );
330 return (void *)GetProcAddress( handle, wide );
332 #elif defined(HAVE_DL_WINDOWS) && defined(WIN32)
333 return (void *)GetProcAddress( handle, (char *)psz_function );
335 #elif defined(HAVE_DL_DLOPEN)
336 return dlsym( handle, psz_function );
338 #elif defined(HAVE_DL_SHL_LOAD)
340 shl_findsym( &handle, psz_function, TYPE_UNDEFINED, &p_sym );
346 #if defined(HAVE_DL_WINDOWS)
347 static char * GetWindowsError( void )
349 #if defined(UNDER_CE)
350 wchar_t psz_tmp[MAX_PATH];
351 char * psz_buffer = malloc( MAX_PATH );
353 char * psz_tmp = malloc( MAX_PATH );
355 int i = 0, i_error = GetLastError();
357 FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
358 NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
359 (LPTSTR)psz_tmp, MAX_PATH, NULL );
361 /* Go to the end of the string */
362 while( psz_tmp[i] && psz_tmp[i] != _T('\r') && psz_tmp[i] != _T('\n') )
369 #if defined(UNDER_CE)
370 swprintf( psz_tmp + i, L" (error %i)", i_error );
371 psz_tmp[ 255 ] = L'\0';
373 snprintf( psz_tmp + i, 256 - i, " (error %i)", i_error );
374 psz_tmp[ 255 ] = '\0';
378 #if defined(UNDER_CE)
379 wcstombs( psz_buffer, psz_tmp, MAX_PATH );
385 #endif /* HAVE_DL_WINDOWS */
386 #endif /* HAVE_DYNAMIC_PLUGINS */