/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen * 2000 Wim Taymans * * gstplugin.c: Plugin subsystem for loading elements, types, and libs * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #ifdef HAVE_DIRENT_H #include #endif #ifdef HAVE_UNISTD_H #include #endif #include #include "gst_private.h" #include "gstplugin.h" #include "gstversion.h" #include "gstregistrypool.h" #include "gstinfo.h" #include "gstfilter.h" #define GST_CAT_DEFAULT GST_CAT_PLUGIN_LOADING static GModule *main_module = NULL; static GList *_gst_plugin_static = NULL; /* static variables for segfault handling of plugin loading */ static char *_gst_plugin_fault_handler_filename = NULL; extern gboolean *_gst_disable_segtrap; /* see gst.c */ #ifndef HAVE_WIN32 static gboolean *_gst_plugin_fault_handler_is_setup = FALSE; #endif /* list of valid licenses. * One of these must be specified or the plugin won't be loaded * Contact gstreamer-devel@lists.sourceforge.net if your license should be * added. * * GPL: http://www.gnu.org/copyleft/gpl.html * LGPL: http://www.gnu.org/copyleft/lesser.html * QPL: http://www.trolltech.com/licenses/qpl.html */ static gchar *valid_licenses[] = { "LGPL", /* GNU Lesser General Public License */ "GPL", /* GNU General Public License */ "QPL", /* Trolltech Qt Public License */ "GPL/QPL", /* Combi-license of GPL + QPL */ GST_LICENSE_UNKNOWN, /* some other license */ NULL }; static void gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src); static GstPlugin *gst_plugin_register_func (GstPlugin * plugin, GModule * module, GstPluginDesc * desc); static GstPlugin * gst_plugin_copy (GstPlugin * plugin) { return g_memdup (plugin, sizeof (*plugin)); } GType gst_plugin_get_type (void) { static GType plugin_type; if (plugin_type == 0) { plugin_type = g_boxed_type_register_static ("GstPlugin", (GBoxedCopyFunc) gst_plugin_copy, g_free); } return plugin_type; } GQuark gst_plugin_error_quark (void) { static GQuark quark = 0; if (!quark) quark = g_quark_from_static_string ("gst_plugin_error"); return quark; } /* this function can be called in the GCC constructor extension, before * the _gst_plugin_initialize() was called. In that case, we store the * plugin description in a list to initialize it when we open the main * module later on. * When the main module is known, we can register the plugin right away. * */ void _gst_plugin_register_static (GstPluginDesc * desc) { if (main_module == NULL) { if (GST_CAT_DEFAULT) GST_LOG ("queueing static plugin \"%s\" for loading later on", desc->name); _gst_plugin_static = g_list_prepend (_gst_plugin_static, desc); } else { GstPlugin *plugin; if (GST_CAT_DEFAULT) GST_LOG ("attempting to load static plugin \"%s\" now...", desc->name); plugin = g_new0 (GstPlugin, 1); if (gst_plugin_register_func (plugin, main_module, desc)) { if (GST_CAT_DEFAULT) GST_INFO ("loaded static plugin \"%s\"", desc->name); gst_registry_pool_add_plugin (plugin); } } } void _gst_plugin_initialize (void) { main_module = g_module_open (NULL, G_MODULE_BIND_LAZY); /* now register all static plugins */ g_list_foreach (_gst_plugin_static, (GFunc) _gst_plugin_register_static, NULL); } /* this function could be extended to check if the plugin license matches the * applications license (would require the app to register its license somehow). * We'll wait for someone who's interested in it to code it :) */ static gboolean gst_plugin_check_license (const gchar * license) { gchar **check_license = valid_licenses; g_assert (check_license); while (*check_license) { if (strcmp (license, *check_license) == 0) return TRUE; check_license++; } return FALSE; } static gboolean gst_plugin_check_version (gint major, gint minor) { /* return NULL if the major and minor version numbers are not compatible */ /* with ours. */ if (major != GST_VERSION_MAJOR || minor != GST_VERSION_MINOR) return FALSE; return TRUE; } static GstPlugin * gst_plugin_register_func (GstPlugin * plugin, GModule * module, GstPluginDesc * desc) { g_assert (plugin->module == NULL); if (!gst_plugin_check_version (desc->major_version, desc->minor_version)) { if (GST_CAT_DEFAULT) GST_INFO ("plugin \"%s\" has incompatible version, not loading", plugin->filename); return FALSE; } if (!desc->license || !desc->description || !desc->package || !desc->origin) { if (GST_CAT_DEFAULT) GST_INFO ("plugin \"%s\" has incorrect GstPluginDesc, not loading", plugin->filename); return FALSE; } if (!gst_plugin_check_license (desc->license)) { if (GST_CAT_DEFAULT) GST_INFO ("plugin \"%s\" has invalid license \"%s\", not loading", plugin->filename, desc->license); return FALSE; } gst_plugin_desc_copy (&plugin->desc, desc); plugin->module = module; if (!((desc->plugin_init) (plugin))) { if (GST_CAT_DEFAULT) GST_INFO ("plugin \"%s\" failed to initialise", plugin->filename); plugin->module = NULL; return FALSE; } if (GST_CAT_DEFAULT) GST_LOG ("plugin \"%s\" initialised", GST_STR_NULL (plugin->filename)); return plugin; } #ifndef HAVE_WIN32 /* * _gst_plugin_fault_handler_restore: * segfault handler restorer */ static void _gst_plugin_fault_handler_restore (void) { struct sigaction action; memset (&action, 0, sizeof (action)); action.sa_handler = SIG_DFL; sigaction (SIGSEGV, &action, NULL); } /* * _gst_plugin_fault_handler_sighandler: * segfault handler implementation */ static void _gst_plugin_fault_handler_sighandler (int signum) { /* We need to restore the fault handler or we'll keep getting it */ _gst_plugin_fault_handler_restore (); switch (signum) { case SIGSEGV: g_print ("\nERROR: "); g_print ("Caught a segmentation fault while loading plugin file:\n"); g_print ("%s\n\n", _gst_plugin_fault_handler_filename); g_print ("Please either:\n"); g_print ("- remove it and restart.\n"); g_print ("- run with --gst-disable-segtrap and debug.\n"); exit (-1); break; default: g_print ("Caught unhandled signal on plugin loading\n"); break; } } /* * _gst_plugin_fault_handler_setup: * sets up the segfault handler */ static void _gst_plugin_fault_handler_setup (void) { struct sigaction action; /* if asked to leave segfaults alone, just return */ if (_gst_disable_segtrap) return; if (_gst_plugin_fault_handler_is_setup) return; memset (&action, 0, sizeof (action)); action.sa_handler = _gst_plugin_fault_handler_sighandler; sigaction (SIGSEGV, &action, NULL); } #else static void _gst_plugin_fault_handler_restore (void) { } static void _gst_plugin_fault_handler_setup (void) { } #endif static void _gst_plugin_fault_handler_setup (); /** * gst_plugin_check_file: * @filename: the plugin filename to check for pluginness * @error: pointer to a NULL-valued GError * * Checks if the given path represents a GStreamer plugin. * * Returns: TRUE if the given path is a GStreamer plugin. */ gboolean gst_plugin_check_file (const gchar * filename, GError ** error) { GModule *module; struct stat file_status; gpointer ptr; g_return_val_if_fail (filename != NULL, FALSE); if (g_module_supported () == FALSE) { g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "Dynamic loading not supported"); return FALSE; } if (stat (filename, &file_status)) { g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "Problem opening file %s\n", filename); return FALSE; } module = g_module_open (filename, G_MODULE_BIND_LAZY); if (module == NULL) { GST_DEBUG ("Error loading plugin %s, reason: %s\n", filename, g_module_error ()); g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "Error loading plugin %s, reason: %s\n", filename, g_module_error ()); return FALSE; } if (!g_module_symbol (module, "gst_plugin_desc", &ptr)) { GST_DEBUG ("Could not find plugin entry point in \"%s\"", filename); g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "Could not find plugin entry point in \"%s\"", filename); g_module_close (module); return FALSE; } /* it's a plugin */ g_module_close (module); return TRUE; } /** * gst_plugin_load_file: * @filename: the plugin filename to load * @error: pointer to a NULL-valued GError * * Loads the given plugin. * * Returns: a new GstPlugin or NULL, if an error occurred. */ GstPlugin * gst_plugin_load_file (const gchar * filename, GError ** error) { GstPlugin *plugin; GModule *module; GstPluginDesc *desc; gboolean free_plugin; gpointer ptr; g_return_val_if_fail (filename != NULL, NULL); GST_CAT_DEBUG (GST_CAT_PLUGIN_LOADING, "attempt to load plugin \"%s\"", filename); if (!gst_plugin_check_file (filename, error)) return NULL; module = g_module_open (filename, G_MODULE_BIND_LAZY); if (module == NULL) goto load_error; if (!g_module_symbol (module, "gst_plugin_desc", &ptr)) goto load_error; desc = (GstPluginDesc *) ptr; plugin = gst_registry_pool_find_plugin (desc->name); if (!plugin) { free_plugin = TRUE; plugin = g_new0 (GstPlugin, 1); plugin->filename = g_strdup (filename); GST_DEBUG ("created new GstPlugin %p for file \"%s\"", plugin, filename); } else { free_plugin = FALSE; if (gst_plugin_is_loaded (plugin)) { if (plugin->filename && strcmp (plugin->filename, filename) != 0) { GST_WARNING ("plugin %p from file \"%s\" with same name %s is already " "loaded, aborting loading of \"%s\"", plugin, plugin->filename, plugin->desc.name, filename); g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_NAME_MISMATCH, "plugin %p from file \"%s\" with same name %s is already " "loaded, aborting loading of \"%s\"", plugin, plugin->filename, plugin->desc.name, filename); if (free_plugin) g_free (plugin); return NULL; } GST_LOG ("Plugin %p for file \"%s\" already loaded, returning it now", plugin, filename); return plugin; } } GST_LOG ("Plugin %p for file \"%s\" prepared, calling entry function...", plugin, filename); if (g_module_symbol (module, "plugin_init", &ptr)) { g_print ("plugin %p from file \"%s\" exports a symbol named plugin_init\n", plugin, plugin->filename); g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_NAME_MISMATCH, "plugin \"%s\" exports a symbol named plugin_init", desc->name); } /* this is where we load the actual .so, so let's trap SIGSEGV */ _gst_plugin_fault_handler_setup (); _gst_plugin_fault_handler_filename = plugin->filename; if (gst_plugin_register_func (plugin, module, desc)) { /* remove signal handler */ _gst_plugin_fault_handler_restore (); _gst_plugin_fault_handler_filename = NULL; GST_INFO ("plugin \"%s\" loaded", plugin->filename); return plugin; } else { /* remove signal handler */ _gst_plugin_fault_handler_restore (); GST_DEBUG ("gst_plugin_register_func failed for plugin \"%s\"", filename); /* plugin == NULL */ g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "gst_plugin_register_func failed for plugin \"%s\"", filename); if (free_plugin) g_free (plugin); return NULL; } load_error: g_set_error (error, GST_PLUGIN_ERROR, GST_PLUGIN_ERROR_MODULE, "generic load error for \"%s\"", filename); return NULL; } static void gst_plugin_desc_copy (GstPluginDesc * dest, const GstPluginDesc * src) { dest->major_version = src->major_version; dest->minor_version = src->minor_version; g_free (dest->name); dest->name = g_strdup (src->name); g_free (dest->description); dest->description = g_strdup (src->description); dest->plugin_init = src->plugin_init; dest->plugin_exit = src->plugin_exit; g_free (dest->version); dest->version = g_strdup (src->version); g_free (dest->license); dest->license = g_strdup (src->license); g_free (dest->package); dest->package = g_strdup (src->package); g_free (dest->origin); dest->origin = g_strdup (src->origin); } #if 0 /* unused */ static void gst_plugin_desc_free (GstPluginDesc * desc) { g_free (desc->name); g_free (desc->description); g_free (desc->version); g_free (desc->license); g_free (desc->package); g_free (desc->origin); memset (desc, 0, sizeof (GstPluginDesc)); } #endif /** * gst_plugin_unload_plugin: * @plugin: The plugin to unload * * Unload the given plugin. * * Returns: whether or not the plugin unloaded */ gboolean gst_plugin_unload_plugin (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, FALSE); if (!plugin->module) return TRUE; if (g_module_close (plugin->module)) { plugin->module = NULL; GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "plugin \"%s\" unloaded", plugin->filename); return TRUE; } else { GST_CAT_INFO (GST_CAT_PLUGIN_LOADING, "failed to unload plugin \"%s\"", plugin->filename); return FALSE; } } /** * gst_plugin_get_name: * @plugin: plugin to get the name of * * Get the short name of the plugin * * Returns: the name of the plugin */ const gchar * gst_plugin_get_name (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, NULL); return plugin->desc.name; } /** * gst_plugin_get_description: * @plugin: plugin to get long name of * * Get the long descriptive name of the plugin * * Returns: the long name of the plugin */ G_CONST_RETURN gchar * gst_plugin_get_description (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, NULL); return plugin->desc.description; } /** * gst_plugin_get_filename: * @plugin: plugin to get the filename of * * get the filename of the plugin * * Returns: the filename of the plugin */ G_CONST_RETURN gchar * gst_plugin_get_filename (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, NULL); return plugin->filename; } /** * gst_plugin_get_license: * @plugin: plugin to get the license of * * get the license of the plugin * * Returns: the license of the plugin */ G_CONST_RETURN gchar * gst_plugin_get_license (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, NULL); return plugin->desc.license; } /** * gst_plugin_get_package: * @plugin: plugin to get the package of * * get the package the plugin belongs to. * * Returns: the package of the plugin */ G_CONST_RETURN gchar * gst_plugin_get_package (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, NULL); return plugin->desc.package; } /** * gst_plugin_get_origin: * @plugin: plugin to get the origin of * * get the URL where the plugin comes from * * Returns: the origin of the plugin */ G_CONST_RETURN gchar * gst_plugin_get_origin (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, NULL); return plugin->desc.origin; } /** * gst_plugin_get_module: * @plugin: plugin to query * * Gets the #GModule of the plugin. If the plugin isn't loaded yet, NULL is * returned. * * Returns: module belonging to the plugin or NULL if the plugin isn't * loaded yet. */ GModule * gst_plugin_get_module (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, FALSE); return plugin->module; } /** * gst_plugin_is_loaded: * @plugin: plugin to query * * queries if the plugin is loaded into memory * * Returns: TRUE is loaded, FALSE otherwise */ gboolean gst_plugin_is_loaded (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, FALSE); return (plugin->module != NULL); } /** * gst_plugin_feature_list: * @plugin: plugin to query * @filter: the filter to use * @first: only return first match * @user_data: user data passed to the filter function * * Runs a filter against all plugin features and returns a GList with * the results. If the first flag is set, only the first match is * returned (as a list with a single object). * * Returns: a GList of features, g_list_free after use. */ GList * gst_plugin_feature_filter (GstPlugin * plugin, GstPluginFeatureFilter filter, gboolean first, gpointer user_data) { return gst_filter_run (plugin->features, (GstFilterFunc) filter, first, user_data); } typedef struct { GstPluginFeatureFilter filter; gboolean first; gpointer user_data; GList *result; } FeatureFilterData; static gboolean _feature_filter (GstPlugin * plugin, gpointer user_data) { GList *result; FeatureFilterData *data = (FeatureFilterData *) user_data; result = gst_plugin_feature_filter (plugin, data->filter, data->first, data->user_data); if (result) { data->result = g_list_concat (data->result, result); return TRUE; } return FALSE; } /** * gst_plugin_list_feature_list: * @list: a list of plugins to query * @filter: the filter to use * @first: only return first match * @user_data: user data passed to the filter function * * Runs a filter against all plugin features of the plugins in the given * list and returns a GList with the results. * If the first flag is set, only the first match is * returned (as a list with a single object). * * Returns: a GList of features, g_list_free after use. */ GList * gst_plugin_list_feature_filter (GList * list, GstPluginFeatureFilter filter, gboolean first, gpointer user_data) { FeatureFilterData data; GList *result; data.filter = filter; data.first = first; data.user_data = user_data; data.result = NULL; result = gst_filter_run (list, (GstFilterFunc) _feature_filter, first, &data); g_list_free (result); return data.result; } /** * gst_plugin_name_filter: * @plugin: the plugin to check * @name: the name of the plugin * * A standard filter that returns TRUE when the plugin is of the * given name. * * Returns: TRUE if the plugin is of the given name. */ gboolean gst_plugin_name_filter (GstPlugin * plugin, const gchar * name) { return (plugin->desc.name && !strcmp (plugin->desc.name, name)); } /** * gst_plugin_find_feature: * @plugin: plugin to get the feature from * @name: The name of the feature to find * @type: The type of the feature to find * * Find a feature of the given name and type in the given plugin. * * Returns: a GstPluginFeature or NULL if the feature was not found. */ GstPluginFeature * gst_plugin_find_feature (GstPlugin * plugin, const gchar * name, GType type) { GList *walk; GstPluginFeature *result = NULL; GstTypeNameData data; g_return_val_if_fail (name != NULL, NULL); data.type = type; data.name = name; walk = gst_filter_run (plugin->features, (GstFilterFunc) gst_plugin_feature_type_name_filter, TRUE, &data); if (walk) result = GST_PLUGIN_FEATURE (walk->data); return result; } /** * gst_plugin_add_feature: * @plugin: plugin to add feature to * @feature: feature to add * * Add feature to the list of those provided by the plugin. * There is a separate namespace for each plugin feature type. * See #gst_plugin_get_feature_list */ void gst_plugin_add_feature (GstPlugin * plugin, GstPluginFeature * feature) { GstPluginFeature *oldfeature; /* FIXME 0.9: get reference counting somewhat right in here, * GstPluginFeatures should probably be GstObjects that are sinked when * adding them to a plugin */ g_return_if_fail (plugin != NULL); g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature)); g_return_if_fail (feature != NULL); oldfeature = gst_plugin_find_feature (plugin, GST_PLUGIN_FEATURE_NAME (feature), G_OBJECT_TYPE (feature)); if (oldfeature == feature) { GST_WARNING ("feature %s has already been added", GST_PLUGIN_FEATURE_NAME (feature)); /* g_object_unref (feature); */ } else if (oldfeature) { GST_WARNING ("feature %s already present in plugin", GST_PLUGIN_FEATURE_NAME (feature)); /* g_object_unref (feature); */ } else { feature->manager = plugin; plugin->features = g_list_prepend (plugin->features, feature); plugin->numfeatures++; } } /** * gst_plugin_get_feature_list: * @plugin: the plugin to get the features from * * get a list of all the features that this plugin provides * * Returns: a GList of features, use g_list_free to free the list. */ GList * gst_plugin_get_feature_list (GstPlugin * plugin) { g_return_val_if_fail (plugin != NULL, NULL); return g_list_copy (plugin->features); } /** * gst_plugin_load: * @name: name of plugin to load * * Load the named plugin. * * Returns: whether the plugin was loaded or not */ gboolean gst_plugin_load (const gchar * name) { GstPlugin *plugin; GError *error = NULL; plugin = gst_registry_pool_find_plugin (name); if (plugin) { gst_plugin_load_file (plugin->filename, &error); if (error) { GST_WARNING ("load_plugin error: %s\n", error->message); g_error_free (error); return FALSE; } return TRUE;; } GST_DEBUG ("Could not find %s in registry pool", name); return FALSE; } /** * gst_library_load: * @name: name of library to load * * Load the named library. Name should be given as * "liblibrary.so". * * Returns: whether the library was loaded or not */ gboolean gst_library_load (const gchar * name) { gboolean res; /* for now this is the same */ res = gst_plugin_load (name); return res; }