/* * Asterisk -- An open source telephony toolkit. * * Copyright (C) 1999 - 2008, Digium, Inc. * * Mark Spencer * Kevin P. Fleming * Luigi Rizzo * * See http://www.asterisk.org for more information about * the Asterisk project. Please do not directly contact * any of the maintainers of this project for assistance; * the project provides a web site, mailing lists and IRC * channels for your use. * * This program is free software, distributed under the terms of * the GNU General Public License Version 2. See the LICENSE file * at the top of the source tree. */ /*! \file * \brief Asterisk module definitions. * * This file contains the definitons for functions Asterisk modules should * provide and some other module related functions. */ #ifndef _ASTERISK_MODULE_H #define _ASTERISK_MODULE_H #include "asterisk/utils.h" #if defined(__cplusplus) || defined(c_plusplus) extern "C" { #endif /*! \brief The text the key() function should return. */ #define ASTERISK_GPL_KEY \ "This paragraph is copyright (c) 2006 by Digium, Inc. \ In order for your module to load, it must return this \ key via a function called \"key\". Any code which \ includes this paragraph must be licensed under the GNU \ General Public License version 2 or later (at your \ option). In addition to Digium's general reservations \ of rights, Digium expressly reserves the right to \ allow other parties to license this paragraph under \ different terms. Any use of Digium, Inc. trademarks or \ logos (including \"Asterisk\" or \"Digium\") without \ express written permission of Digium, Inc. is prohibited.\n" #define AST_MODULE_CONFIG "modules.conf" /*!< \brief Module configuration file */ enum ast_module_unload_mode { AST_FORCE_SOFT = 0, /*!< Softly unload a module, only if not in use */ AST_FORCE_FIRM = 1, /*!< Firmly unload a module, even if in use */ AST_FORCE_HARD = 2, /*!< as FIRM, plus dlclose() on the module. Not recommended as it may cause crashes */ }; enum ast_module_load_result { AST_MODULE_LOAD_SUCCESS = 0, /*!< Module loaded and configured */ AST_MODULE_LOAD_DECLINE = 1, /*!< Module is not configured */ AST_MODULE_LOAD_SKIP = 2, /*!< Module was skipped for some reason */ AST_MODULE_LOAD_PRIORITY = 3, /*!< Module is not loaded yet, but is added to prioity heap */ AST_MODULE_LOAD_FAILURE = -1, /*!< Module could not be loaded properly */ }; /*! * \brief Load a module. * \param resource_name The name of the module to load. * * This function is run by the PBX to load the modules. It performs * all loading and initialization tasks. Basically, to load a module, just * give it the name of the module and it will do the rest. * * \return See possible enum values for ast_module_load_result. */ enum ast_module_load_result ast_load_resource(const char *resource_name); /*! * \brief Unload a module. * \param resource_name The name of the module to unload. * \param ast_module_unload_mode The force flag. This should be set using one of the AST_FORCE flags. * * This function unloads a module. It will only unload modules that are not in * use (usecount not zero), unless #AST_FORCE_FIRM or #AST_FORCE_HARD is * specified. Setting #AST_FORCE_FIRM or #AST_FORCE_HARD will unload the * module regardless of consequences (NOT RECOMMENDED). * * \retval 0 on success. * \retval -1 on error. */ int ast_unload_resource(const char *resource_name, enum ast_module_unload_mode); /*! * \brief Notify when usecount has been changed. * * This function calulates use counts and notifies anyone trying to keep track * of them. It should be called whenever your module's usecount changes. * * \note The ast_module_user_* functions take care of calling this function for you. */ void ast_update_use_count(void); /*! * \brief Ask for a list of modules, descriptions, and use counts. * \param modentry A callback to an updater function. * \param like * * For each of the modules loaded, modentry will be executed with the resource, * description, and usecount values of each particular module. * * \return the number of modules loaded */ int ast_update_module_list(int (*modentry)(const char *module, const char *description, int usecnt, const char *like), const char *like); /*! * \brief Check if module with the name given is loaded * \param name Module name, like "chan_sip.so" * \retval 1 if true * \retval 0 if false */ int ast_module_check(const char *name); /*! * \brief Add a procedure to be run when modules have been updated. * \param updater The function to run when modules have been updated. * * This function adds the given function to a linked list of functions to be * run when the modules are updated. * * \retval 0 on success * \retval -1 on failure. */ int ast_loader_register(int (*updater)(void)); /*! * \brief Remove a procedure to be run when modules are updated. * \param updater The updater function to unregister. * * This removes the given function from the updater list. * * \retval 0 on success * \retval -1 on failure. */ int ast_loader_unregister(int (*updater)(void)); /*! * \brief Run the unload() callback for all loaded modules * * This function should be called when Asterisk is shutting down gracefully. */ void ast_module_shutdown(void); /*! * \brief Match modules names for the Asterisk cli. * \param line Unused by this function, but this should be the line we are * matching. * \param word The partial name to match. * \param pos The position the word we are completing is in. * \param state The possible match to return. * \param rpos The position we should be matching. This should be the same as * pos. * \param needsreload This should be 1 if we need to reload this module and 0 * otherwise. This function will only return modules that are reloadble * if this is 1. * * \retval A possible completion of the partial match. * \retval NULL if no matches were found. */ char *ast_module_helper(const char *line, const char *word, int pos, int state, int rpos, int needsreload); /* Opaque type for module handles generated by the loader */ struct ast_module; /* User count routines keep track of which channels are using a given module resource. They can help make removing modules safer, particularly if they're in use at the time they have been requested to be removed */ struct ast_module_user; struct ast_module_user_list; /*! \page ModMngmnt The Asterisk Module management interface * * All modules must implement the module API (load, unload...) */ enum ast_module_flags { AST_MODFLAG_DEFAULT = 0, AST_MODFLAG_GLOBAL_SYMBOLS = (1 << 0), AST_MODFLAG_LOAD_ORDER = (1 << 1), }; enum ast_module_load_priority { AST_MODPRI_REALTIME_DEPEND = 10, /*!< Dependency for a realtime driver */ AST_MODPRI_REALTIME_DEPEND2 = 20, /*!< Second level dependency for a realtime driver (func_curl needs res_curl, but is needed by res_config_curl) */ AST_MODPRI_REALTIME_DRIVER = 30, /*!< A realtime driver, which provides configuration services for other modules */ AST_MODPRI_CHANNEL_DEPEND = 50, /*!< Channel driver dependency (may depend upon realtime, e.g. MOH) */ AST_MODPRI_CHANNEL_DRIVER = 60, /*!< Channel drivers (provide devicestate) */ AST_MODPRI_APP_DEPEND = 70, /*!< Dependency for an application */ AST_MODPRI_DEVSTATE_PROVIDER = 80, /*!< Applications and other modules that _provide_ devicestate (e.g. meetme) */ AST_MODPRI_DEVSTATE_PLUGIN = 90, /*!< Plugin for a module that provides devstate (e.g. res_calendar_*) */ AST_MODPRI_CDR_DRIVER = 100, /*!< CDR or CEL backend */ AST_MODPRI_DEFAULT = 128, /*!< Modules not otherwise defined (such as most apps) will load here */ AST_MODPRI_DEVSTATE_CONSUMER = 150, /*!< Certain modules, which consume devstate, need to load after all others (e.g. app_queue) */ }; struct ast_module_info { /*! * The 'self' pointer for a module; it will be set by the loader before * it calls the module's load_module() entrypoint, and used by various * other macros that need to identify the module. */ struct ast_module *self; enum ast_module_load_result (*load)(void); /*!< register stuff etc. Optional. */ int (*reload)(void); /*!< config etc. Optional. */ int (*unload)(void); /*!< unload. called with the module locked */ int (*backup_globals)(void); /*!< for embedded modules, backup global data */ void (*restore_globals)(void); /*!< for embedded modules, restore global data */ const char *name; /*!< name of the module for loader reference and CLI commands */ const char *description; /*!< user friendly description of the module. */ /*! * This holds the ASTERISK_GPL_KEY, signifiying that you agree to the terms of * the Asterisk license as stated in the ASTERISK_GPL_KEY. Your module will not * load if it does not return the EXACT key string. */ const char *key; unsigned int flags; /*! The value of AST_BUILDOPT_SUM when this module was compiled */ const char buildopt_sum[33]; /*! This value represents the order in which a module's load() function is initialized. * The lower this value, the higher the priority. The value is only checked if the * AST_MODFLAG_LOAD_ORDER flag is set. If the AST_MODFLAG_LOAD_ORDER flag is not set, * this value will never be read and the module will be given the lowest possible priority * on load. */ unsigned char load_pri; /*! Modules which should be loaded first, in comma-separated string format. * These are only required for loading, when the optional_api header file * detects that the compiler does not support the optional API featureset. */ const char *nonoptreq; }; void ast_module_register(const struct ast_module_info *); void ast_module_unregister(const struct ast_module_info *); struct ast_module_user *__ast_module_user_add(struct ast_module *, struct ast_channel *); void __ast_module_user_remove(struct ast_module *, struct ast_module_user *); void __ast_module_user_hangup_all(struct ast_module *); #define ast_module_user_add(chan) __ast_module_user_add(ast_module_info->self, chan) #define ast_module_user_remove(user) __ast_module_user_remove(ast_module_info->self, user) #define ast_module_user_hangup_all() __ast_module_user_hangup_all(ast_module_info->self) struct ast_module *ast_module_ref(struct ast_module *); void ast_module_unref(struct ast_module *); #if defined(__cplusplus) || defined(c_plusplus) #define AST_MODULE_INFO(keystr, flags_to_set, desc, load_func, unload_func, reload_func, load_pri) \ static struct ast_module_info __mod_info = { \ NULL, \ load_func, \ reload_func, \ unload_func, \ NULL, \ NULL, \ AST_MODULE, \ desc, \ keystr, \ flags_to_set, \ AST_BUILDOPT_SUM, \ load_pri, \ }; \ static void __attribute__((constructor)) __reg_module(void) \ { \ ast_module_register(&__mod_info); \ } \ static void __attribute__((destructor)) __unreg_module(void) \ { \ ast_module_unregister(&__mod_info); \ } \ static const __attribute__((unused)) struct ast_module_info *ast_module_info = &__mod_info #define AST_MODULE_INFO_STANDARD(keystr, desc) \ AST_MODULE_INFO(keystr, AST_MODFLAG_LOAD_ORDER, desc, \ load_module, \ unload_module, \ NULL, \ AST_MODPRI_DEFAULT \ ) #else /* plain C */ /* forward declare this pointer in modules, so that macro/function calls that need it can get it, since it will actually be declared and populated at the end of the module's source file... */ static const __attribute__((unused)) struct ast_module_info *ast_module_info; #if !defined(EMBEDDED_MODULE) #define __MODULE_INFO_SECTION #define __MODULE_INFO_GLOBALS #else /* * For embedded modules we need additional information to backup and * restore the global variables in the module itself, so we can unload * reload the module. * EMBEDDED_MODULE is defined as the module name, so the calls to make_var() * below will actually define different symbols for each module. */ #define __MODULE_INFO_SECTION __attribute__((section(".embed_module"))) #define __MODULE_INFO_GLOBALS .backup_globals = __backup_globals, .restore_globals = __restore_globals, #define make_var_sub(mod, type) __ ## mod ## _ ## type #define make_var(mod, type) make_var_sub(mod, type) extern void make_var(EMBEDDED_MODULE, bss_start); extern void make_var(EMBEDDED_MODULE, bss_end); extern void make_var(EMBEDDED_MODULE, data_start); extern void make_var(EMBEDDED_MODULE, data_end); static void * __attribute__((section(".embed_module"))) __global_backup; static int __backup_globals(void) { size_t data_size = & make_var(EMBEDDED_MODULE, data_end) - & make_var(EMBEDDED_MODULE, data_start); if (__global_backup) return 0; if (!data_size) return 0; if (!(__global_backup = ast_malloc(data_size))) return -1; memcpy(__global_backup, & make_var(EMBEDDED_MODULE, data_start), data_size); return 0; } static void __restore_globals(void) { size_t data_size = & make_var(EMBEDDED_MODULE, data_end) - & make_var(EMBEDDED_MODULE, data_start); size_t bss_size = & make_var(EMBEDDED_MODULE, bss_end) - & make_var(EMBEDDED_MODULE, bss_start); if (bss_size) memset(& make_var(EMBEDDED_MODULE, bss_start), 0, bss_size); if (!data_size || !__global_backup) return; memcpy(& make_var(EMBEDDED_MODULE, data_start), __global_backup, data_size); } #undef make_var #undef make_var_sub #endif /* EMBEDDED_MODULE */ #define AST_MODULE_INFO(keystr, flags_to_set, desc, fields...) \ static struct ast_module_info \ __MODULE_INFO_SECTION \ __mod_info = { \ __MODULE_INFO_GLOBALS \ .name = AST_MODULE, \ .flags = flags_to_set, \ .description = desc, \ .key = keystr, \ .buildopt_sum = AST_BUILDOPT_SUM, \ fields \ }; \ static void __attribute__((constructor)) __reg_module(void) \ { \ ast_module_register(&__mod_info); \ } \ static void __attribute__((destructor)) __unreg_module(void) \ { \ ast_module_unregister(&__mod_info); \ } \ static const struct ast_module_info *ast_module_info = &__mod_info #define AST_MODULE_INFO_STANDARD(keystr, desc) \ AST_MODULE_INFO(keystr, AST_MODFLAG_LOAD_ORDER, desc, \ .load = load_module, \ .unload = unload_module, \ .load_pri = AST_MODPRI_DEFAULT, \ ) #endif /* plain C */ /*! * \brief Register an application. * * \param app Short name of the application * \param execute a function callback to execute the application. It should return * non-zero if the channel needs to be hung up. * \param synopsis a short description (one line synopsis) of the application * \param description long description with all of the details about the use of * the application * * This registers an application with Asterisk's internal application list. * \note The individual applications themselves are responsible for registering and unregistering * and unregistering their own CLI commands. * * \retval 0 success * \retval -1 failure. */ #define ast_register_application(app, execute, synopsis, description) ast_register_application2(app, execute, synopsis, description, ast_module_info->self) /*! * \brief Register an application using XML documentation. * * \param app Short name of the application * \param execute a function callback to execute the application. It should return * non-zero if the channel needs to be hung up. * * This registers an application with Asterisk's internal application list. * \note The individual applications themselves are responsible for registering and unregistering * and unregistering their own CLI commands. * * \retval 0 success * \retval -1 failure. */ #define ast_register_application_xml(app, execute) ast_register_application(app, execute, NULL, NULL) /*! * \brief Register an application. * * \param app Short name of the application * \param execute a function callback to execute the application. It should return * non-zero if the channel needs to be hung up. * \param synopsis a short description (one line synopsis) of the application * \param description long description with all of the details about the use of * the application * \param mod module this application belongs to * * This registers an application with Asterisk's internal application list. * \note The individual applications themselves are responsible for registering and unregistering * and unregistering their own CLI commands. * * \retval 0 success * \retval -1 failure. */ int ast_register_application2(const char *app, int (*execute)(struct ast_channel *, const char *), const char *synopsis, const char *description, void *mod); /*! * \brief Unregister an application * * \param app name of the application (does not have to be the same string as the one that was registered) * * This unregisters an application from Asterisk's internal application list. * * \retval 0 success * \retval -1 failure */ int ast_unregister_application(const char *app); #if defined(__cplusplus) || defined(c_plusplus) } #endif #endif /* _ASTERISK_MODULE_H */