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 <stdlib.h> /* free(), strtol() */
32 #include <stdio.h> /* sprintf() */
33 #include <string.h> /* strdup() */
35 #ifdef HAVE_SYS_TYPES_H
36 # include <sys/types.h>
39 #if !defined(HAVE_DYNAMIC_PLUGINS)
40 /* no support for plugins */
41 #elif defined(HAVE_DL_DYLD)
42 # if defined(HAVE_MACH_O_DYLD_H)
43 # include <mach-o/dyld.h>
45 #elif defined(HAVE_DL_BEOS)
46 # if defined(HAVE_IMAGE_H)
49 #elif defined(HAVE_DL_WINDOWS)
51 #elif defined(HAVE_DL_DLOPEN)
52 # if defined(HAVE_DLFCN_H) /* Linux, BSD, Hurd */
55 # if defined(HAVE_SYS_DL_H)
58 #elif defined(HAVE_DL_SHL_LOAD)
59 # if defined(HAVE_DL_H)
64 /*****************************************************************************
66 *****************************************************************************/
67 #ifdef HAVE_DYNAMIC_PLUGINS
68 static void * GetSymbol ( module_handle_t, const char * );
70 #if defined(HAVE_DL_WINDOWS)
71 static char * GetWindowsError ( void );
74 /*****************************************************************************
75 * module_Call: call an entry point.
76 *****************************************************************************
77 * This function calls a symbol given its name and a module structure. The
78 * symbol MUST refer to a function returning int and taking a module_t* as
80 *****************************************************************************/
81 int module_Call( module_t * p_module )
83 static const char psz_name[] = "vlc_entry" MODULE_SUFFIX;
84 int (* pf_symbol) ( module_t * p_module );
86 /* Try to resolve the symbol */
87 pf_symbol = (int (*)(module_t *)) GetSymbol( p_module->handle, psz_name );
89 if( pf_symbol == NULL )
91 #if defined(HAVE_DL_DYLD) || defined(HAVE_DL_BEOS)
92 msg_Warn( p_module, "cannot find symbol \"%s\" in file `%s'",
93 psz_name, p_module->psz_filename );
94 #elif defined(HAVE_DL_WINDOWS)
95 char *psz_error = GetWindowsError();
96 msg_Warn( p_module, "cannot find symbol \"%s\" in file `%s' (%s)",
97 psz_name, p_module->psz_filename, psz_error );
99 #elif defined(HAVE_DL_DLOPEN)
100 msg_Warn( p_module, "cannot find symbol \"%s\" in file `%s' (%s)",
101 psz_name, p_module->psz_filename, dlerror() );
102 #elif defined(HAVE_DL_SHL_LOAD)
103 msg_Warn( p_module, "cannot find symbol \"%s\" in file `%s' (%m)",
104 psz_name, p_module->psz_filename );
106 # error "Something is wrong in modules.c"
111 /* We can now try to call the symbol */
112 if( pf_symbol( p_module ) != 0 )
114 /* With a well-written module we shouldn't have to print an
115 * additional error message here, but just make sure. */
116 msg_Err( p_module, "Failed to call symbol \"%s\" in file `%s'",
117 psz_name, p_module->psz_filename );
121 /* Everything worked fine, we can return */
125 /*****************************************************************************
126 * module_Load: loads a dynamic library
127 *****************************************************************************
128 * This function loads a dynamically linked library using a system dependant
129 * method. Will return 0 on success as well as the module handle.
130 *****************************************************************************/
131 int module_Load( vlc_object_t *p_this, const char *psz_file,
132 module_handle_t *p_handle )
134 module_handle_t handle;
136 #if defined(HAVE_DL_DYLD)
137 NSObjectFileImage image;
138 NSObjectFileImageReturnCode ret;
140 ret = NSCreateObjectFileImageFromFile( psz_file, &image );
142 if( ret != NSObjectFileImageSuccess )
144 msg_Warn( p_this, "cannot create image from `%s'", psz_file );
148 /* Open the dynamic module */
149 handle = NSLinkModule( image, psz_file,
150 NSLINKMODULE_OPTION_RETURN_ON_ERROR );
154 NSLinkEditErrors errors;
155 const char *psz_file, *psz_err;
157 NSLinkEditError( &errors, &i_errnum, &psz_file, &psz_err );
158 msg_Warn( p_this, "cannot link module `%s' (%s)", psz_file, psz_err );
159 NSDestroyObjectFileImage( image );
163 /* Destroy our image, we won't need it */
164 NSDestroyObjectFileImage( image );
166 #elif defined(HAVE_DL_BEOS)
167 handle = load_add_on( psz_file );
170 msg_Warn( p_this, "cannot load module `%s'", psz_file );
174 #elif defined(HAVE_DL_WINDOWS)
177 wchar_t psz_wfile[MAX_PATH];
178 MultiByteToWideChar( CP_ACP, 0, psz_file, -1, psz_wfile, MAX_PATH );
179 handle = LoadLibrary( psz_wfile );
182 handle = LoadLibrary( psz_file );
186 char *psz_err = GetWindowsError();
187 msg_Warn( p_this, "cannot load module `%s' (%s)", psz_file, psz_err );
192 #elif defined(HAVE_DL_DLOPEN) && defined(RTLD_NOW)
193 /* static is OK, we are called atomically */
194 handle = dlopen( psz_file, RTLD_NOW );
197 msg_Warn( p_this, "cannot load module `%s' (%s)",
198 psz_file, dlerror() );
202 #elif defined(HAVE_DL_DLOPEN)
203 # if defined(DL_LAZY)
204 handle = dlopen( psz_file, DL_LAZY );
206 handle = dlopen( psz_file, 0 );
210 msg_Warn( p_this, "cannot load module `%s' (%s)",
211 psz_file, dlerror() );
215 #elif defined(HAVE_DL_SHL_LOAD)
216 handle = shl_load( psz_file, BIND_IMMEDIATE | BIND_NONFATAL, NULL );
219 msg_Warn( p_this, "cannot load module `%s' (%m)", psz_file );
224 # error "Something is wrong in modules.c"
232 /*****************************************************************************
233 * CloseModule: unload a dynamic library
234 *****************************************************************************
235 * This function unloads a previously opened dynamically linked library
236 * using a system dependant method. No return value is taken in consideration,
237 * since some libraries sometimes refuse to close properly.
238 *****************************************************************************/
239 void module_Unload( module_handle_t handle )
241 #if defined(HAVE_DL_DYLD)
242 NSUnLinkModule( handle, FALSE );
244 #elif defined(HAVE_DL_BEOS)
245 unload_add_on( handle );
247 #elif defined(HAVE_DL_WINDOWS)
248 FreeLibrary( handle );
250 #elif defined(HAVE_DL_DLOPEN)
255 #elif defined(HAVE_DL_SHL_LOAD)
256 shl_unload( handle );
262 /*****************************************************************************
263 * GetSymbol: get a symbol from a dynamic library
264 *****************************************************************************
265 * This function queries a loaded library for a symbol specified in a
266 * string, and returns a pointer to it. We don't check for dlerror() or
267 * similar functions, since we want a non-NULL symbol anyway.
268 *****************************************************************************/
269 static void * _module_getsymbol( module_handle_t, const char * );
271 static void * GetSymbol( module_handle_t handle, const char * psz_function )
273 void * p_symbol = _module_getsymbol( handle, psz_function );
275 /* MacOS X dl library expects symbols to begin with "_". So do
276 * some other operating systems. That's really lame, but hey, what
278 if( p_symbol == NULL )
280 char psz_call[strlen( psz_function ) + 2];
283 memcpy( psz_call + 1, psz_function, sizeof (psz_call) - 1 );
284 p_symbol = _module_getsymbol( handle, psz_call );
290 static void * _module_getsymbol( module_handle_t handle,
291 const char * psz_function )
293 #if defined(HAVE_DL_DYLD)
294 NSSymbol sym = NSLookupSymbolInModule( handle, psz_function );
295 return NSAddressOfSymbol( sym );
297 #elif defined(HAVE_DL_BEOS)
299 if( B_OK == get_image_symbol( handle, psz_function,
300 B_SYMBOL_TYPE_TEXT, &p_symbol ) )
309 #elif defined(HAVE_DL_WINDOWS) && defined(UNDER_CE)
310 wchar_t psz_real[256];
311 MultiByteToWideChar( CP_ACP, 0, psz_function, -1, psz_real, 256 );
313 return (void *)GetProcAddress( handle, psz_real );
315 #elif defined(HAVE_DL_WINDOWS) && defined(WIN32)
316 return (void *)GetProcAddress( handle, (char *)psz_function );
318 #elif defined(HAVE_DL_DLOPEN)
319 return dlsym( handle, psz_function );
321 #elif defined(HAVE_DL_SHL_LOAD)
323 shl_findsym( &handle, psz_function, TYPE_UNDEFINED, &p_sym );
329 #if defined(HAVE_DL_WINDOWS)
330 static char * GetWindowsError( void )
332 #if defined(UNDER_CE)
333 wchar_t psz_tmp[MAX_PATH];
334 char * psz_buffer = malloc( MAX_PATH );
336 char * psz_tmp = malloc( MAX_PATH );
338 int i = 0, i_error = GetLastError();
340 FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
341 NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
342 (LPTSTR)psz_tmp, MAX_PATH, NULL );
344 /* Go to the end of the string */
345 while( psz_tmp[i] && psz_tmp[i] != _T('\r') && psz_tmp[i] != _T('\n') )
352 #if defined(UNDER_CE)
353 swprintf( psz_tmp + i, L" (error %i)", i_error );
354 psz_tmp[ 255 ] = L'\0';
356 snprintf( psz_tmp + i, 256 - i, " (error %i)", i_error );
357 psz_tmp[ 255 ] = '\0';
361 #if defined(UNDER_CE)
362 wcstombs( psz_buffer, psz_tmp, MAX_PATH );
368 #endif /* HAVE_DL_WINDOWS */
369 #endif /* HAVE_DYNAMIC_PLUGINS */