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/*****************************************************************************
* os.c : Low-level dynamic library handling
*****************************************************************************
* Copyright (C) 2001-2007 the VideoLAN team
* $Id$
*
* Authors: Sam Hocevar <sam@zoy.org>
* Ethan C. Baldridge <BaldridgeE@cadmus.com>
* Hans-Peter Jansen <hpj@urpla.net>
* Gildas Bazin <gbazin@videolan.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <vlc_common.h>
#include <vlc_plugin.h> /* MODULE_SUFFIX */
#include <vlc_charset.h>
#include "libvlc.h"
#include "modules.h"
#include <stdlib.h> /* free(), strtol() */
#include <stdio.h> /* sprintf() */
#include <string.h> /* strdup() */
#include <sys/types.h>
#if !defined(HAVE_DYNAMIC_PLUGINS)
/* no support for plugins */
#elif defined(HAVE_DL_BEOS)
# if defined(HAVE_IMAGE_H)
# include <image.h>
# endif
#elif defined(__APPLE__)
# include <dlfcn.h>
#elif defined(HAVE_DL_WINDOWS)
# include <windows.h>
#elif defined(HAVE_DL_DLOPEN)
# if defined(HAVE_DLFCN_H) /* Linux, BSD, Hurd */
# include <dlfcn.h>
# endif
# if defined(HAVE_SYS_DL_H)
# include <sys/dl.h>
# endif
#elif defined(HAVE_DL_SHL_LOAD)
# if defined(HAVE_DL_H)
# include <dl.h>
# endif
#endif
#ifdef HAVE_VALGRIND_VALGRIND_H
# include <valgrind/valgrind.h>
#endif
/*****************************************************************************
* Local prototypes
*****************************************************************************/
#ifdef HAVE_DYNAMIC_PLUGINS
static void *module_Lookup( module_handle_t, const char * );
#if defined(HAVE_DL_WINDOWS)
static char * GetWindowsError ( void );
#endif
/**
* module Call
*
* Call a symbol given its name and a module structure. The symbol MUST
* refer to a function returning int and taking a module_t* as an argument.
* \param p_module the modules
* \return 0 if it pass and -1 in case of a failure
*/
int module_Call( vlc_object_t *obj, module_t *p_module )
{
static const char psz_name[] = "vlc_entry" MODULE_SUFFIX;
int (* pf_symbol) ( module_t * p_module );
/* Try to resolve the symbol */
pf_symbol = (int (*)(module_t *)) module_Lookup( p_module->handle,
psz_name );
if( pf_symbol == NULL )
{
#if defined(HAVE_DL_BEOS)
msg_Warn( obj, "cannot find symbol \"%s\" in file `%s'",
psz_name, p_module->psz_filename );
#elif defined(HAVE_DL_WINDOWS)
char *psz_error = GetWindowsError();
msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%s)",
psz_name, p_module->psz_filename, psz_error );
free( psz_error );
#elif defined(HAVE_DL_DLOPEN)
msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%s)",
psz_name, p_module->psz_filename, dlerror() );
#elif defined(HAVE_DL_SHL_LOAD)
msg_Warn( obj, "cannot find symbol \"%s\" in file `%s' (%m)",
psz_name, p_module->psz_filename );
#else
# error "Something is wrong in modules.c"
#endif
return -1;
}
/* We can now try to call the symbol */
if( pf_symbol( p_module ) != 0 )
{
/* With a well-written module we shouldn't have to print an
* additional error message here, but just make sure. */
msg_Err( obj, "Failed to call symbol \"%s\" in file `%s'",
psz_name, p_module->psz_filename );
return -1;
}
/* Everything worked fine, we can return */
return 0;
}
/**
* Load a dynamically linked library using a system dependent method.
*
* \param p_this vlc object
* \param psz_file library file
* \param p_handle the module handle returned
* \return 0 on success as well as the module handle.
*/
int module_Load( vlc_object_t *p_this, const char *psz_file,
module_handle_t *p_handle )
{
module_handle_t handle;
#if defined(HAVE_DL_BEOS)
handle = load_add_on( psz_file );
if( handle < 0 )
{
msg_Warn( p_this, "cannot load module `%s'", psz_file );
return -1;
}
#elif defined(HAVE_DL_WINDOWS)
wchar_t psz_wfile[MAX_PATH];
MultiByteToWideChar( CP_UTF8, 0, psz_file, -1, psz_wfile, MAX_PATH );
#ifndef UNDER_CE
/* FIXME: this is not thread-safe -- Courmisch */
UINT mode = SetErrorMode (SEM_FAILCRITICALERRORS);
SetErrorMode (mode|SEM_FAILCRITICALERRORS);
#endif
handle = LoadLibraryW( psz_wfile );
#ifndef UNDER_CE
SetErrorMode (mode);
#endif
if( handle == NULL )
{
char *psz_err = GetWindowsError();
msg_Warn( p_this, "cannot load module `%s' (%s)", psz_file, psz_err );
free( psz_err );
return -1;
}
#elif defined(HAVE_DL_DLOPEN)
# if defined (RTLD_NOW)
const int flags = RTLD_NOW;
# elif defined (DL_LAZY)
const int flags = DL_LAZY;
# else
const int flags = 0;
# endif
char *path = ToLocale( psz_file );
handle = dlopen( path, flags );
if( handle == NULL )
{
msg_Warn( p_this, "cannot load module `%s' (%s)", path, dlerror() );
LocaleFree( path );
return -1;
}
LocaleFree( path );
#elif defined(HAVE_DL_SHL_LOAD)
handle = shl_load( psz_file, BIND_IMMEDIATE | BIND_NONFATAL, NULL );
if( handle == NULL )
{
msg_Warn( p_this, "cannot load module `%s' (%m)", psz_file );
return -1;
}
#else
# error "Something is wrong in modules.c"
#endif
*p_handle = handle;
return 0;
}
/**
* CloseModule: unload a dynamic library
*
* This function unloads a previously opened dynamically linked library
* using a system dependent method. No return value is taken in consideration,
* since some libraries sometimes refuse to close properly.
* \param handle handle of the library
* \return nothing
*/
void module_Unload( module_handle_t handle )
{
#if defined(HAVE_DL_BEOS)
unload_add_on( handle );
#elif defined(HAVE_DL_WINDOWS)
FreeLibrary( handle );
#elif defined(HAVE_DL_DLOPEN)
# ifdef HAVE_VALGRIND_VALGRIND_H
if( RUNNING_ON_VALGRIND > 0 )
return; /* do not dlclose() so that we get proper stack traces */
# endif
dlclose( handle );
#elif defined(HAVE_DL_SHL_LOAD)
shl_unload( handle );
#endif
return;
}
/**
* Looks up a symbol from a dynamically loaded library
*
* This function queries a loaded library for a symbol specified in a
* string, and returns a pointer to it. We don't check for dlerror() or
* similar functions, since we want a non-NULL symbol anyway.
*
* @param handle handle to the module
* @param psz_function function name
* @return NULL on error, or the address of the symbol
*/
static void *module_Lookup( module_handle_t handle, const char *psz_function )
{
#if defined(HAVE_DL_BEOS)
void * p_symbol;
if( B_OK == get_image_symbol( handle, psz_function,
B_SYMBOL_TYPE_TEXT, &p_symbol ) )
{
return p_symbol;
}
else
{
return NULL;
}
#elif defined(HAVE_DL_WINDOWS) && defined(UNDER_CE)
wchar_t wide[strlen( psz_function ) + 1];
size_t i = 0;
do
wide[i] = psz_function[i]; /* UTF-16 <- ASCII */
while( psz_function[i++] );
return (void *)GetProcAddress( handle, wide );
#elif defined(HAVE_DL_WINDOWS) && defined(WIN32)
return (void *)GetProcAddress( handle, (char *)psz_function );
#elif defined(HAVE_DL_DLOPEN)
return dlsym( handle, psz_function );
#elif defined(HAVE_DL_SHL_LOAD)
void *p_sym;
shl_findsym( &handle, psz_function, TYPE_UNDEFINED, &p_sym );
return p_sym;
#endif
}
#if defined(HAVE_DL_WINDOWS)
# include <wchar.h>
static char * GetWindowsError( void )
{
wchar_t wmsg[256];
int i = 0, i_error = GetLastError();
FormatMessageW( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, i_error, MAKELANGID (LANG_NEUTRAL, SUBLANG_DEFAULT),
wmsg, 256, NULL );
/* Go to the end of the string */
while( !wmemchr( L"\r\n\0", wmsg[i], 3 ) )
i++;
snwprintf( wmsg + i, 256 - i, L" (error %i)", i_error );
return FromWide( wmsg );
}
#endif /* HAVE_DL_WINDOWS */
#endif /* HAVE_DYNAMIC_PLUGINS */