asterisk/include/asterisk/module.h

673 lines
26 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2008, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
* Kevin P. Fleming <kpfleming@digium.com>
* Luigi Rizzo <rizzo@icir.org>
*
* 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.
*/
/*! \li \ref module.h uses the configuration file \ref modules.conf
* \addtogroup configuration_file
*/
/*! \page modules.conf modules.conf
* \verbinclude modules.conf.sample
*/
#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 {
/*! Module is loaded and configured. */
AST_MODULE_LOAD_SUCCESS = 0,
/*!
* \brief Module has failed to load, may be in an inconsistent state.
*
* This value is used when a module fails to start but does not risk
* system-wide stability. Declined modules will prevent any other
* dependent module from starting.
*/
AST_MODULE_LOAD_DECLINE = 1,
/*! \internal
* \brief Module was skipped for some reason.
*
* \note For loader.c use only. Should never be returned by modules.
*/
AST_MODULE_LOAD_SKIP = 2,
/*! \internal
* \brief Module is not loaded yet, but is added to priority list.
*
* \note For loader.c use only. Should never be returned by modules.
*/
AST_MODULE_LOAD_PRIORITY = 3,
/*!
* \brief Module could not be loaded properly.
*
* This return should only be returned by modules for unrecoverable
* failures that cause the whole system to become unstable. In almost
* all cases \ref AST_MODULE_LOAD_DECLINE should be used instead.
*
* \warning Returning this code from any module will cause startup to abort.
* If startup is already completed this code has the same effect as
* \ref AST_MODULE_LOAD_DECLINE.
*/
AST_MODULE_LOAD_FAILURE = -1,
};
/*!
* \since 12
* \brief Possible return types for \ref ast_module_reload
*/
enum ast_module_reload_result {
AST_MODULE_RELOAD_SUCCESS = 0, /*!< The module was reloaded succesfully */
AST_MODULE_RELOAD_QUEUED, /*!< The module reload request was queued */
AST_MODULE_RELOAD_NOT_FOUND, /*!< The requested module was not found */
AST_MODULE_RELOAD_ERROR, /*!< An error occurred while reloading the module */
AST_MODULE_RELOAD_IN_PROGRESS, /*!< A module reload request is already in progress */
AST_MODULE_RELOAD_UNINITIALIZED, /*!< The module has not been initialized */
AST_MODULE_RELOAD_NOT_IMPLEMENTED, /*!< This module doesn't support reloading */
};
enum ast_module_support_level {
AST_MODULE_SUPPORT_UNKNOWN,
AST_MODULE_SUPPORT_CORE,
AST_MODULE_SUPPORT_EXTENDED,
AST_MODULE_SUPPORT_DEPRECATED,
};
/*! Used to specify which modules should be returned by ast_module_helper. */
enum ast_module_helper_type {
/*! Modules that are loaded by dlopen. */
AST_MODULE_HELPER_LOADED = 0,
/*! Running modules that include a reload callback. */
AST_MODULE_HELPER_RELOAD = 1,
/*! Modules that can be loaded or started. */
AST_MODULE_HELPER_LOAD,
/*! Modules that can be unloaded. */
AST_MODULE_HELPER_UNLOAD,
/*! Running modules */
AST_MODULE_HELPER_RUNNING,
};
/*!
* \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 Reload asterisk modules.
* \param name the name of the module to reload
*
* This function reloads the specified module, or if no modules are specified,
* it will reload all loaded modules.
*
* \note Modules are reloaded using their reload() functions, not unloading
* them and loading them again.
*
* \retval The \ref ast_module_reload_result status of the module load request
*/
enum ast_module_reload_result ast_module_reload(const char *name);
/*!
* \brief Notify when usecount has been changed.
*
* This function calculates 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, use counts and status.
* \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 *status, const char *like,
enum ast_module_support_level support_level),
const char *like);
/*!
* \brief Ask for a list of modules, descriptions, use counts and status.
* \param modentry A callback to an updater function
* \param like
* \param data Data passed into the callback for manipulation
*
* 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
* \since 13.5.0
*/
int ast_update_module_list_data(int (*modentry)(const char *module, const char *description,
int usecnt, const char *status, const char *like,
enum ast_module_support_level support_level,
void *data),
const char *like, void *data);
/*!
* \brief Ask for a list of modules, descriptions, use counts and status.
* \param modentry A callback to an updater function
* \param like
* \param data Data passed into the callback for manipulation
* \param condition The condition to meet
*
* 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 conditions met
* \since 13.5.0
*/
int ast_update_module_list_condition(int (*modentry)(const char *module, const char *description,
int usecnt, const char *status, const char *like,
enum ast_module_support_level support_level,
void *data, const char *condition),
const char *like, void *data, const char *condition);
/*!
* \brief Check if module with the name given is loaded
* \param name Module name, like "chan_pjsip.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 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 type The type of action that will be performed by CLI.
*
* \retval A possible completion of the partial match.
* \retval NULL if no matches were found or Asterisk is not yet fully booted.
*/
char *ast_module_helper(const char *line, const char *word, int pos, int state, int rpos, enum ast_module_helper_type type);
/* Opaque type for module handles generated by the loader */
struct ast_module;
/*!
* \brief Get the name of a module.
* \param mod A pointer to the module.
* \return the name of the module
* \retval NULL if mod or mod->info is NULL
*/
const char *ast_module_name(const struct ast_module *mod);
/* 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_CORE = 40, /*!< A core module originally meant to start between preload and load. */
AST_MODPRI_TIMING = 50, /*!< Dependency for a channel (MOH needs timing interfaces to be fully loaded) */
AST_MODPRI_CHANNEL_DEPEND = 60, /*!< Channel driver dependency (may depend upon realtime, e.g. MOH) */
AST_MODPRI_CHANNEL_DRIVER = 70, /*!< Channel drivers (provide devicestate) */
AST_MODPRI_APP_DEPEND = 80, /*!< Dependency for an application */
AST_MODPRI_DEVSTATE_PROVIDER = 90, /*!< Applications and other modules that _provide_ devicestate (e.g. meetme) */
AST_MODPRI_DEVSTATE_PLUGIN = 100, /*!< Plugin for a module that provides devstate (e.g. res_calendar_*) */
AST_MODPRI_CDR_DRIVER = 110, /*!< 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;
/*! Register stuff etc. Optional. */
enum ast_module_load_result (*load)(void);
/*! Config etc. Optional. */
int (*reload)(void);
/*! Unload. called with the module locked */
int (*unload)(void);
/*! Name of the module for loader reference and CLI commands */
const char *name;
/*! User friendly description of the module. */
const char *description;
/*!
* This holds the ASTERISK_GPL_KEY, signifying 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 must always be started first, in comma-separated string format. */
const char *requires;
/*!
* \brief Comma-separated list of optionally required modules.
*
* The listed modules are optional, but load order is enforced. For example
* app_voicemail optionally requires res_adsi. This means that app_voicemail
* will happily load without res_adsi, but if both are being loaded the module
* loader will force res_adsi to start first.
*/
const char *optional_modules;
/*!
* \brief Modules that we provide enhanced functionality for.
*
* This is similar to a "requires" but specifies that we add functionality to
* the other modules. Any module that requires something we "enhances" will
* also require us, but only if we are dlopen'ed.
*
* Example:
* - res_fax_spandsp has .enhances = "res_fax".
* - res_my_module has .requires = "res_fax" but has no direct knowledge
* of res_fax_spandsp.
*
* This forces the following startup order among the 3 modules:
* 1) res_fax starts.
* 2) res_fax_spandsp starts, holds a reference to res_fax.
* 3) res_mymod starts, holds a reference to res_fax and res_fax_spandsp.
*
* If res_fax_spandsp were not being loaded res_mymod would load with
* res_fax only. If res_fax_spandsp were later loaded res_mymod would
* get a reference to it.
*/
const char *enhances;
/*! These reserved fields should be NULL, they exist to allow addition to this
* structure in a non-breaking way. */
void *reserved1;
void *reserved2;
void *reserved3;
void *reserved4;
/*! The support level for the given module */
enum ast_module_support_level support_level;
};
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_SELF, chan)
#define ast_module_user_remove(user) __ast_module_user_remove(AST_MODULE_SELF, user)
#define ast_module_user_hangup_all() __ast_module_user_hangup_all(AST_MODULE_SELF)
struct ast_module *__ast_module_ref(struct ast_module *mod, const char *file, int line, const char *func);
struct ast_module *__ast_module_running_ref(struct ast_module *mod, const char *file, int line, const char *func);
void __ast_module_shutdown_ref(struct ast_module *mod, const char *file, int line, const char *func);
void __ast_module_unref(struct ast_module *mod, const char *file, int line, const char *func);
/*!
* \brief Hold a reference to the module
* \param mod Module to reference
* \return mod
*
* \note A module reference will prevent the module
* from being unloaded.
*/
#define ast_module_ref(mod) __ast_module_ref(mod, __FILE__, __LINE__, __PRETTY_FUNCTION__)
/*!
* \brief Hold a reference to the module if it is running.
* \param mod Module to reference
* \retval mod if running
* \retval NULL if not running
*
* The returned pointer should be released with ast_module_unref.
*
* \note A module reference will prevent the module from being unloaded.
*/
#define ast_module_running_ref(mod) \
__ast_module_running_ref(mod, __FILE__, __LINE__, __PRETTY_FUNCTION__)
/*!
* \brief Prevent unload of the module before shutdown
* \param mod Module to hold
*
* \note This should not be balanced by a call to ast_module_unref.
*/
#define ast_module_shutdown_ref(mod) __ast_module_shutdown_ref(mod, __FILE__, __LINE__, __PRETTY_FUNCTION__)
/*!
* \brief Release a reference to the module
* \param mod Module to release
*/
#define ast_module_unref(mod) __ast_module_unref(mod, __FILE__, __LINE__, __PRETTY_FUNCTION__)
#if defined(__cplusplus) || defined(c_plusplus)
#define AST_MODULE_INFO(keystr, flags_to_set, desc, load_func, unload_func, reload_func, load_pri, support_level) \
static struct ast_module_info __mod_info = { \
NULL, \
load_func, \
reload_func, \
unload_func, \
AST_MODULE, \
desc, \
keystr, \
flags_to_set, \
AST_BUILDOPT_SUM, \
load_pri, \
NULL, \
NULL, \
NULL, \
NULL, \
NULL, \
NULL, \
NULL, \
support_level, \
}; \
static void __attribute__((constructor)) __reg_module(void) \
{ \
ast_module_register(&__mod_info); \
} \
static void __attribute__((destructor)) __unreg_module(void) \
{ \
ast_module_unregister(&__mod_info); \
} \
struct ast_module *AST_MODULE_SELF_SYM(void) \
{ \
return __mod_info.self; \
} \
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, \
AST_MODULE_SUPPORT_CORE \
)
#define AST_MODULE_INFO_STANDARD_EXTENDED(keystr, desc) \
AST_MODULE_INFO(keystr, AST_MODFLAG_LOAD_ORDER, desc, \
load_module, \
unload_module, \
NULL, \
AST_MODPRI_DEFAULT, \
AST_MODULE_SUPPORT_EXTENDED \
)
#define AST_MODULE_INFO_STANDARD_DEPRECATED(keystr, desc) \
AST_MODULE_INFO(keystr, AST_MODFLAG_LOAD_ORDER, desc, \
load_module, \
unload_module, \
NULL, \
AST_MODPRI_DEFAULT, \
AST_MODULE_SUPPORT_DEPRECATED \
)
#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... */
#if !defined(AST_IN_CORE)
static const __attribute__((unused)) struct ast_module_info *ast_module_info;
#endif
#define AST_MODULE_INFO(keystr, flags_to_set, desc, fields...) \
static struct ast_module_info \
__mod_info = { \
.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); \
} \
struct ast_module *AST_MODULE_SELF_SYM(void) \
{ \
return __mod_info.self; \
} \
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, \
.support_level = AST_MODULE_SUPPORT_CORE, \
)
#define AST_MODULE_INFO_STANDARD_EXTENDED(keystr, desc) \
AST_MODULE_INFO(keystr, AST_MODFLAG_LOAD_ORDER, desc, \
.load = load_module, \
.unload = unload_module, \
.load_pri = AST_MODPRI_DEFAULT, \
.support_level = AST_MODULE_SUPPORT_EXTENDED, \
)
#define AST_MODULE_INFO_STANDARD_DEPRECATED(keystr, desc) \
AST_MODULE_INFO(keystr, AST_MODFLAG_LOAD_ORDER, desc, \
.load = load_module, \
.unload = unload_module, \
.load_pri = AST_MODPRI_DEFAULT, \
.support_level = AST_MODULE_SUPPORT_DEPRECATED, \
)
#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_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);
const char *ast_module_support_level_to_string(enum ast_module_support_level support_level);
/*! Macro to safely ref and unref the self module for the current scope */
#define SCOPED_MODULE_USE(module) \
RAII_VAR(struct ast_module *, __self__ ## __LINE__, ast_module_ref(module), ast_module_unref)
#if defined(__cplusplus) || defined(c_plusplus)
}
#endif
#endif /* _ASTERISK_MODULE_H */