app.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * 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 Convenient Application Routines
 *
 * \author Mark Spencer <markster@digium.com>
 */

/** \example
 * \par This is an example of how to develop an app.
 * Application Skeleton is an example of creating an application for Asterisk.
 * \verbinclude app_skel.c
 */

/*** MODULEINFO
	<support_level>core</support_level>
 ***/

#include "asterisk.h"

ASTERISK_REGISTER_FILE()

#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#include <regex.h>          /* for regcomp(3) */
#include <sys/file.h>       /* for flock(2) */
#include <signal.h>         /* for pthread_sigmask(3) */
#include <stdlib.h>         /* for closefrom(3) */
#include <sys/types.h>
#include <sys/wait.h>       /* for waitpid(2) */
#ifndef HAVE_CLOSEFROM
#include <dirent.h>         /* for opendir(3)   */
#endif
#ifdef HAVE_CAP
#include <sys/capability.h>
#endif /* HAVE_CAP */

#include "asterisk/paths.h"	/* use ast_config_AST_DATA_DIR */
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/file.h"
#include "asterisk/app.h"
#include "asterisk/dsp.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/indications.h"
#include "asterisk/linkedlists.h"
#include "asterisk/threadstorage.h"
#include "asterisk/test.h"
#include "asterisk/module.h"
#include "asterisk/astobj2.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/json.h"
#include "asterisk/format_cache.h"

#define MWI_TOPIC_BUCKETS 57

AST_THREADSTORAGE_PUBLIC(ast_str_thread_global_buf);

static pthread_t shaun_of_the_dead_thread = AST_PTHREADT_NULL;

struct zombie {
	pid_t pid;
	AST_LIST_ENTRY(zombie) list;
};

static AST_LIST_HEAD_STATIC(zombies, zombie);

/*
 * @{ \brief Define \ref stasis topic objects
 */
static struct stasis_topic *mwi_topic_all;
static struct stasis_cache *mwi_state_cache;
static struct stasis_caching_topic *mwi_topic_cached;
static struct stasis_topic_pool *mwi_topic_pool;

static struct stasis_topic *queue_topic_all;
static struct stasis_topic_pool *queue_topic_pool;
/* @} */

/*! \brief Convert a MWI \ref stasis_message to a \ref ast_event */
static struct ast_event *mwi_to_event(struct stasis_message *message)
{
	struct ast_event *event;
	struct ast_mwi_state *mwi_state;
	char *mailbox;
	char *context;

	if (!message) {
		return NULL;
	}

	mwi_state = stasis_message_data(message);

	/* Strip off @context */
	context = mailbox = ast_strdupa(mwi_state->uniqueid);
	strsep(&context, "@");
	if (ast_strlen_zero(context)) {
		context = "default";
	}

	event = ast_event_new(AST_EVENT_MWI,
				AST_EVENT_IE_MAILBOX, AST_EVENT_IE_PLTYPE_STR, mailbox,
				AST_EVENT_IE_CONTEXT, AST_EVENT_IE_PLTYPE_STR, context,
				AST_EVENT_IE_NEWMSGS, AST_EVENT_IE_PLTYPE_UINT, mwi_state->new_msgs,
				AST_EVENT_IE_OLDMSGS, AST_EVENT_IE_PLTYPE_UINT, mwi_state->old_msgs,
				AST_EVENT_IE_EID, AST_EVENT_IE_PLTYPE_RAW, &mwi_state->eid, sizeof(mwi_state->eid),
				AST_EVENT_IE_END);

	return event;
}

/*
 * @{ \brief Define \ref stasis message types for MWI
 */
STASIS_MESSAGE_TYPE_DEFN(ast_mwi_state_type,
	.to_event = mwi_to_event, );
STASIS_MESSAGE_TYPE_DEFN(ast_mwi_vm_app_type);
/* @} */



static void *shaun_of_the_dead(void *data)
{
	struct zombie *cur;
	int status;
	for (;;) {
		if (!AST_LIST_EMPTY(&zombies)) {
			/* Don't allow cancellation while we have a lock. */
			pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
			AST_LIST_LOCK(&zombies);
			AST_LIST_TRAVERSE_SAFE_BEGIN(&zombies, cur, list) {
				if (waitpid(cur->pid, &status, WNOHANG) != 0) {
					AST_LIST_REMOVE_CURRENT(list);
					ast_free(cur);
				}
			}
			AST_LIST_TRAVERSE_SAFE_END
			AST_LIST_UNLOCK(&zombies);
			pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
		}
		pthread_testcancel();
		/* Wait for 60 seconds, without engaging in a busy loop. */
		ast_poll(NULL, 0, AST_LIST_FIRST(&zombies) ? 5000 : 60000);
	}
	return NULL;
}


#define AST_MAX_FORMATS 10

static AST_RWLIST_HEAD_STATIC(groups, ast_group_info);

/*!
 * \brief This function presents a dialtone and reads an extension into 'collect'
 * which must be a pointer to a **pre-initialized** array of char having a
 * size of 'size' suitable for writing to.  It will collect no more than the smaller
 * of 'maxlen' or 'size' minus the original strlen() of collect digits.
 * \param chan struct.
 * \param context
 * \param collect
 * \param size
 * \param maxlen
 * \param timeout timeout in milliseconds
 *
 * \return 0 if extension does not exist, 1 if extension exists
*/
int ast_app_dtget(struct ast_channel *chan, const char *context, char *collect, size_t size, int maxlen, int timeout)
{
	struct ast_tone_zone_sound *ts;
	int res = 0, x = 0;

	if (maxlen > size) {
		maxlen = size;
	}

	if (!timeout) {
		if (ast_channel_pbx(chan) && ast_channel_pbx(chan)->dtimeoutms) {
			timeout = ast_channel_pbx(chan)->dtimeoutms;
		} else {
			timeout = 5000;
		}
	}

	if ((ts = ast_get_indication_tone(ast_channel_zone(chan), "dial"))) {
		res = ast_playtones_start(chan, 0, ts->data, 0);
		ts = ast_tone_zone_sound_unref(ts);
	} else {
		ast_log(LOG_NOTICE, "Huh....? no dial for indications?\n");
	}

	for (x = strlen(collect); x < maxlen; ) {
		res = ast_waitfordigit(chan, timeout);
		if (!ast_ignore_pattern(context, collect)) {
			ast_playtones_stop(chan);
		}
		if (res < 1) {
			break;
		}
		if (res == '#') {
			break;
		}
		collect[x++] = res;
		if (!ast_matchmore_extension(chan, context, collect, 1,
			S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
			break;
		}
	}

	if (res >= 0) {
		res = ast_exists_extension(chan, context, collect, 1,
			S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL)) ? 1 : 0;
	}

	return res;
}

/*!
 * \brief ast_app_getdata
 * \param c The channel to read from
 * \param prompt The file to stream to the channel
 * \param s The string to read in to.  Must be at least the size of your length
 * \param maxlen How many digits to read (maximum)
 * \param timeout set timeout to 0 for "standard" timeouts. Set timeout to -1 for
 *      "ludicrous time" (essentially never times out) */
enum ast_getdata_result ast_app_getdata(struct ast_channel *c, const char *prompt, char *s, int maxlen, int timeout)
{
	int res = 0, to, fto;
	char *front, *filename;

	/* XXX Merge with full version? XXX */

	if (maxlen)
		s[0] = '\0';

	if (!prompt)
		prompt = "";

	filename = ast_strdupa(prompt);
	while ((front = strsep(&filename, "&"))) {
		if (!ast_strlen_zero(front)) {
			res = ast_streamfile(c, front, ast_channel_language(c));
			if (res)
				continue;
		}
		if (ast_strlen_zero(filename)) {
			/* set timeouts for the last prompt */
			fto = ast_channel_pbx(c) ? ast_channel_pbx(c)->rtimeoutms : 6000;
			to = ast_channel_pbx(c) ? ast_channel_pbx(c)->dtimeoutms : 2000;

			if (timeout > 0) {
				fto = to = timeout;
			}
			if (timeout < 0) {
				fto = to = 1000000000;
			}
		} else {
			/* there is more than one prompt, so
			 * get rid of the long timeout between
			 * prompts, and make it 50ms */
			fto = 50;
			to = ast_channel_pbx(c) ? ast_channel_pbx(c)->dtimeoutms : 2000;
		}
		res = ast_readstring(c, s, maxlen, to, fto, "#");
		if (res == AST_GETDATA_EMPTY_END_TERMINATED) {
			return res;
		}
		if (!ast_strlen_zero(s)) {
			return res;
		}
	}

	return res;
}

/* The lock type used by ast_lock_path() / ast_unlock_path() */
static enum AST_LOCK_TYPE ast_lock_type = AST_LOCK_TYPE_LOCKFILE;

int ast_app_getdata_full(struct ast_channel *c, const char *prompt, char *s, int maxlen, int timeout, int audiofd, int ctrlfd)
{
	int res, to = 2000, fto = 6000;

	if (!ast_strlen_zero(prompt)) {
		res = ast_streamfile(c, prompt, ast_channel_language(c));
		if (res < 0) {
			return res;
		}
	}

	if (timeout > 0) {
		fto = to = timeout;
	}
	if (timeout < 0) {
		fto = to = 1000000000;
	}

	res = ast_readstring_full(c, s, maxlen, to, fto, "#", audiofd, ctrlfd);

	return res;
}

int ast_app_exec_macro(struct ast_channel *autoservice_chan, struct ast_channel *macro_chan, const char *macro_args)
{
	struct ast_app *macro_app;
	int res;

	macro_app = pbx_findapp("Macro");
	if (!macro_app) {
		ast_log(LOG_WARNING,
			"Cannot run 'Macro(%s)'.  The application is not available.\n", macro_args);
		return -1;
	}
	if (autoservice_chan) {
		ast_autoservice_start(autoservice_chan);
	}

	ast_debug(4, "%s Original location: %s,%s,%d\n", ast_channel_name(macro_chan),
		ast_channel_context(macro_chan), ast_channel_exten(macro_chan),
		ast_channel_priority(macro_chan));

	res = pbx_exec(macro_chan, macro_app, macro_args);
	ast_debug(4, "Macro exited with status %d\n", res);

	/*
	 * Assume anything negative from Macro is an error.
	 * Anything else is success.
	 */
	if (res < 0) {
		res = -1;
	} else {
		res = 0;
	}

	ast_debug(4, "%s Ending location: %s,%s,%d\n", ast_channel_name(macro_chan),
		ast_channel_context(macro_chan), ast_channel_exten(macro_chan),
		ast_channel_priority(macro_chan));

	if (autoservice_chan) {
		ast_autoservice_stop(autoservice_chan);
	}
	return res;
}

int ast_app_run_macro(struct ast_channel *autoservice_chan, struct ast_channel *macro_chan, const char *macro_name, const char *macro_args)
{
	int res;
	char *args_str;
	size_t args_len;

	if (ast_strlen_zero(macro_args)) {
		return ast_app_exec_macro(autoservice_chan, macro_chan, macro_name);
	}

	/* Create the Macro application argument string. */
	args_len = strlen(macro_name) + strlen(macro_args) + 2;
	args_str = ast_malloc(args_len);
	if (!args_str) {
		return -1;
	}
	snprintf(args_str, args_len, "%s,%s", macro_name, macro_args);

	res = ast_app_exec_macro(autoservice_chan, macro_chan, args_str);
	ast_free(args_str);
	return res;
}

static const struct ast_app_stack_funcs *app_stack_callbacks;

void ast_install_stack_functions(const struct ast_app_stack_funcs *funcs)
{
	app_stack_callbacks = funcs;
}

const char *ast_app_expand_sub_args(struct ast_channel *chan, const char *args)
{
	const struct ast_app_stack_funcs *funcs;
	const char *new_args;

	funcs = app_stack_callbacks;
	if (!funcs || !funcs->expand_sub_args) {
		ast_log(LOG_WARNING,
			"Cannot expand 'Gosub(%s)' arguments.  The app_stack module is not available.\n",
			args);
		return NULL;
	}
	ast_module_ref(funcs->module);

	new_args = funcs->expand_sub_args(chan, args);
	ast_module_unref(funcs->module);
	return new_args;
}

int ast_app_exec_sub(struct ast_channel *autoservice_chan, struct ast_channel *sub_chan, const char *sub_args, int ignore_hangup)
{
	const struct ast_app_stack_funcs *funcs;
	int res;

	funcs = app_stack_callbacks;
	if (!funcs || !funcs->run_sub) {
		ast_log(LOG_WARNING,
			"Cannot run 'Gosub(%s)'.  The app_stack module is not available.\n",
			sub_args);
		return -1;
	}
	ast_module_ref(funcs->module);

	if (autoservice_chan) {
		ast_autoservice_start(autoservice_chan);
	}

	res = funcs->run_sub(sub_chan, sub_args, ignore_hangup);
	ast_module_unref(funcs->module);

	if (autoservice_chan) {
		ast_autoservice_stop(autoservice_chan);
	}
	return res;
}

int ast_app_run_sub(struct ast_channel *autoservice_chan, struct ast_channel *sub_chan, const char *sub_location, const char *sub_args, int ignore_hangup)
{
	int res;
	char *args_str;
	size_t args_len;

	if (ast_strlen_zero(sub_args)) {
		return ast_app_exec_sub(autoservice_chan, sub_chan, sub_location, ignore_hangup);
	}

	/* Create the Gosub application argument string. */
	args_len = strlen(sub_location) + strlen(sub_args) + 3;
	args_str = ast_malloc(args_len);
	if (!args_str) {
		return -1;
	}
	snprintf(args_str, args_len, "%s(%s)", sub_location, sub_args);

	res = ast_app_exec_sub(autoservice_chan, sub_chan, args_str, ignore_hangup);
	ast_free(args_str);
	return res;
}

/*! \brief The container for the voicemail provider */
static AO2_GLOBAL_OBJ_STATIC(vm_provider);

/*! Voicemail not registered warning */
static int vm_warnings;

int ast_vm_is_registered(void)
{
	struct ast_vm_functions *table;
	int is_registered;

	table = ao2_global_obj_ref(vm_provider);
	is_registered = table ? 1 : 0;
	ao2_cleanup(table);
	return is_registered;
}

int __ast_vm_register(const struct ast_vm_functions *vm_table, struct ast_module *module)
{
	RAII_VAR(struct ast_vm_functions *, table, NULL, ao2_cleanup);

	if (!vm_table->module_name) {
		ast_log(LOG_ERROR, "Voicemail provider missing required information.\n");
		return -1;
	}
	if (vm_table->module_version != VM_MODULE_VERSION) {
		ast_log(LOG_ERROR, "Voicemail provider '%s' has incorrect version\n",
			vm_table->module_name);
		return -1;
	}

	table = ao2_global_obj_ref(vm_provider);
	if (table) {
		ast_log(LOG_WARNING, "Voicemail provider already registered by %s.\n",
			table->module_name);
		return -1;
	}

	table = ao2_alloc_options(sizeof(*table), NULL, AO2_ALLOC_OPT_LOCK_NOLOCK);
	if (!table) {
		return -1;
	}
	*table = *vm_table;
	table->module = module;

	ao2_global_obj_replace_unref(vm_provider, table);
	return 0;
}

void ast_vm_unregister(const char *module_name)
{
	struct ast_vm_functions *table;

	table = ao2_global_obj_ref(vm_provider);
	if (table && !strcmp(table->module_name, module_name)) {
		ao2_global_obj_release(vm_provider);
	}
	ao2_cleanup(table);
}

#ifdef TEST_FRAMEWORK
/*! \brief Holding container for the voicemail provider used while testing */
static AO2_GLOBAL_OBJ_STATIC(vm_provider_holder);
static int provider_is_swapped = 0;

void ast_vm_test_swap_table_in(const struct ast_vm_functions *vm_table)
{
	RAII_VAR(struct ast_vm_functions *, holding_table, NULL, ao2_cleanup);
	RAII_VAR(struct ast_vm_functions *, new_table, NULL, ao2_cleanup);

	if (provider_is_swapped) {
		ast_log(LOG_ERROR, "Attempted to swap in test function table without swapping out old test table.\n");
		return;
	}

	holding_table = ao2_global_obj_ref(vm_provider);

	if (holding_table) {
		ao2_global_obj_replace_unref(vm_provider_holder, holding_table);
	}

	new_table = ao2_alloc_options(sizeof(*new_table), NULL, AO2_ALLOC_OPT_LOCK_NOLOCK);
	if (!new_table) {
		return;
	}
	*new_table = *vm_table;

	ao2_global_obj_replace_unref(vm_provider, new_table);
	provider_is_swapped = 1;
}

void ast_vm_test_swap_table_out(void)
{
	RAII_VAR(struct ast_vm_functions *, held_table, NULL, ao2_cleanup);

	if (!provider_is_swapped) {
		ast_log(LOG_ERROR, "Attempted to swap out test function table, but none is currently installed.\n");
		return;
	}

	held_table = ao2_global_obj_ref(vm_provider_holder);
	if (!held_table) {
		return;
	}

	ao2_global_obj_replace_unref(vm_provider, held_table);
	ao2_global_obj_release(vm_provider_holder);
	provider_is_swapped = 0;
}
#endif

/*! \brief The container for the voicemail greeter provider */
static AO2_GLOBAL_OBJ_STATIC(vm_greeter_provider);

/*! Voicemail greeter not registered warning */
static int vm_greeter_warnings;

int ast_vm_greeter_is_registered(void)
{
	struct ast_vm_greeter_functions *table;
	int is_registered;

	table = ao2_global_obj_ref(vm_greeter_provider);
	is_registered = table ? 1 : 0;
	ao2_cleanup(table);
	return is_registered;
}

int __ast_vm_greeter_register(const struct ast_vm_greeter_functions *vm_table, struct ast_module *module)
{
	RAII_VAR(struct ast_vm_greeter_functions *, table, NULL, ao2_cleanup);

	if (!vm_table->module_name) {
		ast_log(LOG_ERROR, "Voicemail greeter provider missing required information.\n");
		return -1;
	}
	if (vm_table->module_version != VM_GREETER_MODULE_VERSION) {
		ast_log(LOG_ERROR, "Voicemail greeter provider '%s' has incorrect version\n",
			vm_table->module_name);
		return -1;
	}

	table = ao2_global_obj_ref(vm_greeter_provider);
	if (table) {
		ast_log(LOG_WARNING, "Voicemail greeter provider already registered by %s.\n",
			table->module_name);
		return -1;
	}

	table = ao2_alloc_options(sizeof(*table), NULL, AO2_ALLOC_OPT_LOCK_NOLOCK);
	if (!table) {
		return -1;
	}
	*table = *vm_table;
	table->module = module;

	ao2_global_obj_replace_unref(vm_greeter_provider, table);
	return 0;
}

void ast_vm_greeter_unregister(const char *module_name)
{
	struct ast_vm_greeter_functions *table;

	table = ao2_global_obj_ref(vm_greeter_provider);
	if (table && !strcmp(table->module_name, module_name)) {
		ao2_global_obj_release(vm_greeter_provider);
	}
	ao2_cleanup(table);
}

#ifdef TEST_FRAMEWORK
static ast_vm_test_create_user_fn *ast_vm_test_create_user_func = NULL;
static ast_vm_test_destroy_user_fn *ast_vm_test_destroy_user_func = NULL;

void ast_install_vm_test_functions(ast_vm_test_create_user_fn *vm_test_create_user_func,
	ast_vm_test_destroy_user_fn *vm_test_destroy_user_func)
{
	ast_vm_test_create_user_func = vm_test_create_user_func;
	ast_vm_test_destroy_user_func = vm_test_destroy_user_func;
}

void ast_uninstall_vm_test_functions(void)
{
	ast_vm_test_create_user_func = NULL;
	ast_vm_test_destroy_user_func = NULL;
}
#endif

static void vm_warn_no_provider(void)
{
	if (vm_warnings++ % 10 == 0) {
		ast_verb(3, "No voicemail provider registered.\n");
	}
}

#define VM_API_CALL(res, api_call, api_parms)								\
	do {																	\
		struct ast_vm_functions *table;										\
		table = ao2_global_obj_ref(vm_provider);							\
		if (!table) {														\
			vm_warn_no_provider();											\
		} else if (table->api_call) {										\
			ast_module_ref(table->module);									\
			(res) = table->api_call api_parms;								\
			ast_module_unref(table->module);								\
		}																	\
		ao2_cleanup(table);													\
	} while (0)

static void vm_greeter_warn_no_provider(void)
{
	if (vm_greeter_warnings++ % 10 == 0) {
		ast_verb(3, "No voicemail greeter provider registered.\n");
	}
}

#define VM_GREETER_API_CALL(res, api_call, api_parms)						\
	do {																	\
		struct ast_vm_greeter_functions *table;								\
		table = ao2_global_obj_ref(vm_greeter_provider);					\
		if (!table) {														\
			vm_greeter_warn_no_provider();									\
		} else if (table->api_call) {										\
			ast_module_ref(table->module);									\
			(res) = table->api_call api_parms;								\
			ast_module_unref(table->module);								\
		}																	\
		ao2_cleanup(table);													\
	} while (0)

int ast_app_has_voicemail(const char *mailboxes, const char *folder)
{
	int res = 0;

	VM_API_CALL(res, has_voicemail, (mailboxes, folder));
	return res;
}

/*!
 * \internal
 * \brief Function used as a callback for ast_copy_recording_to_vm when a real one isn't installed.
 * \param vm_rec_data Stores crucial information about the voicemail that will basically just be used
 * to figure out what the name of the recipient was supposed to be
 */
int ast_app_copy_recording_to_vm(struct ast_vm_recording_data *vm_rec_data)
{
	int res = -1;

	VM_API_CALL(res, copy_recording_to_vm, (vm_rec_data));
	return res;
}

int ast_app_inboxcount(const char *mailboxes, int *newmsgs, int *oldmsgs)
{
	int res = 0;

	if (newmsgs) {
		*newmsgs = 0;
	}
	if (oldmsgs) {
		*oldmsgs = 0;
	}

	VM_API_CALL(res, inboxcount, (mailboxes, newmsgs, oldmsgs));
	return res;
}

int ast_app_inboxcount2(const char *mailboxes, int *urgentmsgs, int *newmsgs, int *oldmsgs)
{
	int res = 0;

	if (newmsgs) {
		*newmsgs = 0;
	}
	if (oldmsgs) {
		*oldmsgs = 0;
	}
	if (urgentmsgs) {
		*urgentmsgs = 0;
	}

	VM_API_CALL(res, inboxcount2, (mailboxes, urgentmsgs, newmsgs, oldmsgs));
	return res;
}

int ast_app_sayname(struct ast_channel *chan, const char *mailbox_id)
{
	int res = -1;

	VM_GREETER_API_CALL(res, sayname, (chan, mailbox_id));
	return res;
}

int ast_app_messagecount(const char *mailbox_id, const char *folder)
{
	int res = 0;

	VM_API_CALL(res, messagecount, (mailbox_id, folder));
	return res;
}

const char *ast_vm_index_to_foldername(int id)
{
	const char *res = NULL;

	VM_API_CALL(res, index_to_foldername, (id));
	return res;
}

struct ast_vm_mailbox_snapshot *ast_vm_mailbox_snapshot_create(const char *mailbox,
	const char *context,
	const char *folder,
	int descending,
	enum ast_vm_snapshot_sort_val sort_val,
	int combine_INBOX_and_OLD)
{
	struct ast_vm_mailbox_snapshot *res = NULL;

	VM_API_CALL(res, mailbox_snapshot_create, (mailbox, context, folder, descending,
		sort_val, combine_INBOX_and_OLD));
	return res;
}

struct ast_vm_mailbox_snapshot *ast_vm_mailbox_snapshot_destroy(struct ast_vm_mailbox_snapshot *mailbox_snapshot)
{
	struct ast_vm_mailbox_snapshot *res = NULL;

	VM_API_CALL(res, mailbox_snapshot_destroy, (mailbox_snapshot));
	return res;
}

int ast_vm_msg_move(const char *mailbox,
	const char *context,
	size_t num_msgs,
	const char *oldfolder,
	const char *old_msg_ids[],
	const char *newfolder)
{
	int res = 0;

	VM_API_CALL(res, msg_move, (mailbox, context, num_msgs, oldfolder, old_msg_ids,
		newfolder));
	return res;
}

int ast_vm_msg_remove(const char *mailbox,
	const char *context,
	size_t num_msgs,
	const char *folder,
	const char *msgs[])
{
	int res = 0;

	VM_API_CALL(res, msg_remove, (mailbox, context, num_msgs, folder, msgs));
	return res;
}

int ast_vm_msg_forward(const char *from_mailbox,
	const char *from_context,
	const char *from_folder,
	const char *to_mailbox,
	const char *to_context,
	const char *to_folder,
	size_t num_msgs,
	const char *msg_ids[],
	int delete_old)
{
	int res = 0;

	VM_API_CALL(res, msg_forward, (from_mailbox, from_context, from_folder, to_mailbox,
		to_context, to_folder, num_msgs, msg_ids, delete_old));
	return res;
}

int ast_vm_msg_play(struct ast_channel *chan,
	const char *mailbox,
	const char *context,
	const char *folder,
	const char *msg_num,
	ast_vm_msg_play_cb *cb)
{
	int res = 0;

	VM_API_CALL(res, msg_play, (chan, mailbox, context, folder, msg_num, cb));
	return res;
}

#ifdef TEST_FRAMEWORK
int ast_vm_test_create_user(const char *context, const char *mailbox)
{
	if (ast_vm_test_create_user_func) {
		return ast_vm_test_create_user_func(context, mailbox);
	}
	return 0;
}

int ast_vm_test_destroy_user(const char *context, const char *mailbox)
{
	if (ast_vm_test_destroy_user_func) {
		return ast_vm_test_destroy_user_func(context, mailbox);
	}
	return 0;
}
#endif

int ast_dtmf_stream(struct ast_channel *chan, struct ast_channel *peer, const char *digits, int between, unsigned int duration)
{
	const char *ptr;
	int res;
	struct ast_silence_generator *silgen = NULL;

	if (!between) {
		between = 100;
	}

	if (peer && ast_autoservice_start(peer)) {
		return -1;
	}

	/* Need a quiet time before sending digits. */
	if (ast_opt_transmit_silence) {
		silgen = ast_channel_start_silence_generator(chan);
	}
	res = ast_safe_sleep(chan, 100);
	if (res) {
		goto dtmf_stream_cleanup;
	}

	for (ptr = digits; *ptr; ptr++) {
		if (*ptr == 'w') {
			/* 'w' -- wait half a second */
			if ((res = ast_safe_sleep(chan, 500))) {
				break;
			}
		} else if (*ptr == 'W') {
			/* 'W' -- wait a second */
			if ((res = ast_safe_sleep(chan, 1000))) {
				break;
			}
		} else if (strchr("0123456789*#abcdfABCDF", *ptr)) {
			if (*ptr == 'f' || *ptr == 'F') {
				/* ignore return values if not supported by channel */
				ast_indicate(chan, AST_CONTROL_FLASH);
			} else {
				/* Character represents valid DTMF */
				ast_senddigit(chan, *ptr, duration);
			}
			/* pause between digits */
			if ((res = ast_safe_sleep(chan, between))) {
				break;
			}
		} else {
			ast_log(LOG_WARNING, "Illegal DTMF character '%c' in string. (0-9*#aAbBcCdD allowed)\n", *ptr);
		}
	}

dtmf_stream_cleanup:
	if (silgen) {
		ast_channel_stop_silence_generator(chan, silgen);
	}
	if (peer && ast_autoservice_stop(peer)) {
		res = -1;
	}

	return res;
}

struct linear_state {
	int fd;
	int autoclose;
	int allowoverride;
	struct ast_format *origwfmt;
};

static void linear_release(struct ast_channel *chan, void *params)
{
	struct linear_state *ls = params;

	if (ls->origwfmt && ast_set_write_format(chan, ls->origwfmt)) {
		ast_log(LOG_WARNING, "Unable to restore channel '%s' to format '%s'\n",
			ast_channel_name(chan), ast_format_get_name(ls->origwfmt));
	}
	ao2_cleanup(ls->origwfmt);

	if (ls->autoclose) {
		close(ls->fd);
	}

	ast_free(params);
}

static int linear_generator(struct ast_channel *chan, void *data, int len, int samples)
{
	short buf[2048 + AST_FRIENDLY_OFFSET / 2];
	struct linear_state *ls = data;
	struct ast_frame f = {
		.frametype = AST_FRAME_VOICE,
		.data.ptr = buf + AST_FRIENDLY_OFFSET / 2,
		.offset = AST_FRIENDLY_OFFSET,
	};
	int res;

	f.subclass.format = ast_format_slin;

	len = samples * 2;
	if (len > sizeof(buf) - AST_FRIENDLY_OFFSET) {
		ast_log(LOG_WARNING, "Can't generate %d bytes of data!\n" , len);
		len = sizeof(buf) - AST_FRIENDLY_OFFSET;
	}
	res = read(ls->fd, buf + AST_FRIENDLY_OFFSET/2, len);
	if (res > 0) {
		f.datalen = res;
		f.samples = res / 2;
		ast_write(chan, &f);
		if (res == len) {
			return 0;
		}
	}
	return -1;
}

static void *linear_alloc(struct ast_channel *chan, void *params)
{
	struct linear_state *ls = params;

	if (!params) {
		return NULL;
	}

	/* In this case, params is already malloc'd */
	if (ls->allowoverride) {
		ast_set_flag(ast_channel_flags(chan), AST_FLAG_WRITE_INT);
	} else {
		ast_clear_flag(ast_channel_flags(chan), AST_FLAG_WRITE_INT);
	}

	ls->origwfmt = ao2_bump(ast_channel_writeformat(chan));