asterisk/funcs/func_periodic_hook.c

524 lines
13 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2014, Russell Bryant
*
* Russell Bryant <russell@russellbryant.net>
*
* 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 Periodic dialplan hooks.
*
* \author Russell Bryant <russell@russellbryant.net>
*
* \ingroup functions
*/
/*** MODULEINFO
<depend>app_chanspy</depend>
<depend>func_cut</depend>
<depend>func_groupcount</depend>
<depend>func_uri</depend>
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"
#include "asterisk/audiohook.h"
#define AST_API_MODULE
#include "asterisk/beep.h"
/*** DOCUMENTATION
<function name="PERIODIC_HOOK" language="en_US">
<synopsis>
Execute a periodic dialplan hook into the audio of a call.
</synopsis>
<syntax>
<parameter name="context" required="true">
<para>(On Read Only) Context for the hook extension.</para>
</parameter>
<parameter name="extension" required="true">
<para>(On Read Only) The hook extension.</para>
</parameter>
<parameter name="interval" required="true">
<para>(On Read Only) Number of seconds in between hook runs.
Whole seconds only.</para>
</parameter>
<parameter name="hook_id" required="true">
<para>(On Write Only) The hook ID.</para>
</parameter>
</syntax>
<description>
<para>For example, you could use this function to enable playing
a periodic <literal>beep</literal> sound in a call.</para>
<para/>
<example title="To turn on">
same => n,Set(BEEPID=${PERIODIC_HOOK(hooks,beep,180)})
</example>
<example title="To turn off">
same => n,Set(PERIODIC_HOOK(${BEEPID})=off)
</example>
<example title="To turn back on again later">
same => n,Set(PERIODIC_HOOK(${BEEPID})=on)
</example>
<para>It is important to note that the hook does not actually
run on the channel itself. It runs asynchronously on a new channel.
Any audio generated by the hook gets injected into the call for
the channel PERIODIC_HOOK() was set on.</para>
<para/>
<para>The hook dialplan will have two variables available.
<variable>HOOK_CHANNEL</variable> is the channel the hook is
enabled on. <variable>HOOK_ID</variable> is the hook ID for
enabling or disabling the hook.</para>
</description>
</function>
***/
static const char context_name[] = "__func_periodic_hook_context__";
static const char exten_name[] = "hook";
static const char full_exten_name[] = "hook@__func_periodic_hook_context__";
static const char beep_exten[] = "beep";
/*!
* \brief Last used hook ID
*
* This is incremented each time a hook is created to give each hook a unique
* ID.
*/
static unsigned int global_hook_id;
/*! State put in a datastore to track the state of the hook */
struct hook_state {
/*!
* \brief audiohook used as a callback into this module
*
* \note The code assumes this is the first element in the struct
*/
struct ast_audiohook audiohook;
/*! Seconds between each hook run */
unsigned int interval;
/*! The last time the hook ran */
struct timeval last_hook;
/*! Dialplan context for the hook */
char *context;
/*! Dialplan extension for the hook */
char *exten;
/*! Hook ID */
unsigned int hook_id;
/*! Non-zero if the hook is currently disabled */
unsigned char disabled;
};
static void hook_datastore_destroy_callback(void *data)
{
struct hook_state *state = data;
ast_audiohook_lock(&state->audiohook);
ast_audiohook_detach(&state->audiohook);
ast_audiohook_unlock(&state->audiohook);
ast_audiohook_destroy(&state->audiohook);
ast_free(state->context);
ast_free(state->exten);
ast_free(state);
}
static const struct ast_datastore_info hook_datastore = {
.type = AST_MODULE,
.destroy = hook_datastore_destroy_callback,
};
/*! Arguments to the thread that launches the hook */
struct hook_thread_arg {
/*! Hook ID */
char *hook_id;
/*! Name of the channel the hook was set on */
char *chan_name;
/*! Dialplan context for the hook */
char *context;
/*! Dialplan extension for the hook */
char *exten;
};
static void hook_thread_arg_destroy(struct hook_thread_arg *arg)
{
ast_free(arg->hook_id);
ast_free(arg->chan_name);
ast_free(arg->context);
ast_free(arg->exten);
ast_free(arg);
}
static void *hook_launch_thread(void *data)
{
struct hook_thread_arg *arg = data;
struct ast_variable hook_id = {
.name = "HOOK_ID",
.value = arg->hook_id,
};
struct ast_variable chan_name_var = {
.name = "HOOK_CHANNEL",
.value = arg->chan_name,
.next = &hook_id,
};
ast_pbx_outgoing_exten("Local", NULL, full_exten_name, 60,
arg->context, arg->exten, 1, NULL, AST_OUTGOING_NO_WAIT,
NULL, NULL, &chan_name_var, NULL, NULL, 1, NULL);
hook_thread_arg_destroy(arg);
return NULL;
}
static struct hook_thread_arg *hook_thread_arg_alloc(struct ast_channel *chan,
struct hook_state *state)
{
struct hook_thread_arg *arg;
if (!(arg = ast_calloc(1, sizeof(*arg)))) {
return NULL;
}
ast_channel_lock(chan);
arg->chan_name = ast_strdup(ast_channel_name(chan));
ast_channel_unlock(chan);
if (!arg->chan_name) {
hook_thread_arg_destroy(arg);
return NULL;
}
if (ast_asprintf(&arg->hook_id, "%u", state->hook_id) == -1) {
hook_thread_arg_destroy(arg);
return NULL;
}
if (!(arg->context = ast_strdup(state->context))) {
hook_thread_arg_destroy(arg);
return NULL;
}
if (!(arg->exten = ast_strdup(state->exten))) {
hook_thread_arg_destroy(arg);
return NULL;
}
return arg;
}
static int do_hook(struct ast_channel *chan, struct hook_state *state)
{
pthread_t t;
struct hook_thread_arg *arg;
int res;
if (!(arg = hook_thread_arg_alloc(chan, state))) {
return -1;
}
/*
* We don't want to block normal frame processing *at all* while we kick
* this off, so do it in a new thread.
*/
res = ast_pthread_create_detached_background(&t, NULL, hook_launch_thread, arg);
if (res != 0) {
hook_thread_arg_destroy(arg);
}
return res;
}
static int hook_callback(struct ast_audiohook *audiohook, struct ast_channel *chan,
struct ast_frame *frame, enum ast_audiohook_direction direction)
{
struct hook_state *state = (struct hook_state *) audiohook; /* trust me. */
struct timeval now;
int res = 0;
if (audiohook->status == AST_AUDIOHOOK_STATUS_DONE || state->disabled) {
return 0;
}
now = ast_tvnow();
if (ast_tvdiff_ms(now, state->last_hook) > state->interval * 1000) {
if ((res = do_hook(chan, state))) {
const char *name;
ast_channel_lock(chan);
name = ast_strdupa(ast_channel_name(chan));
ast_channel_unlock(chan);
ast_log(LOG_WARNING, "Failed to run hook on '%s'\n", name);
}
state->last_hook = now;
}
return res;
}
static struct hook_state *hook_state_alloc(const char *context, const char *exten,
unsigned int interval, unsigned int hook_id)
{
struct hook_state *state;
if (!(state = ast_calloc(1, sizeof(*state)))) {
return NULL;
}
state->context = ast_strdup(context);
state->exten = ast_strdup(exten);
state->interval = interval;
state->hook_id = hook_id;
ast_audiohook_init(&state->audiohook, AST_AUDIOHOOK_TYPE_MANIPULATE,
AST_MODULE, AST_AUDIOHOOK_MANIPULATE_ALL_RATES);
state->audiohook.manipulate_callback = hook_callback;
return state;
}
static int init_hook(struct ast_channel *chan, const char *context, const char *exten,
unsigned int interval, unsigned int hook_id)
{
struct hook_state *state;
struct ast_datastore *datastore;
char uid[32];
snprintf(uid, sizeof(uid), "%u", hook_id);
if (!(datastore = ast_datastore_alloc(&hook_datastore, uid))) {
return -1;
}
if (!(state = hook_state_alloc(context, exten, interval, hook_id))) {
ast_datastore_free(datastore);
return -1;
}
datastore->data = state;
ast_channel_lock(chan);
ast_channel_datastore_add(chan, datastore);
ast_audiohook_attach(chan, &state->audiohook);
ast_channel_unlock(chan);
return 0;
}
static int hook_on(struct ast_channel *chan, const char *data, unsigned int hook_id)
{
char *parse = ast_strdupa(S_OR(data, ""));
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(context);
AST_APP_ARG(exten);
AST_APP_ARG(interval);
);
unsigned int interval;
AST_STANDARD_APP_ARGS(args, parse);
if (ast_strlen_zero(args.interval) ||
sscanf(args.interval, "%30u", &interval) != 1 || interval == 0) {
ast_log(LOG_WARNING, "Invalid hook interval: '%s'\n", S_OR(args.interval, ""));
return -1;
}
if (ast_strlen_zero(args.context) || ast_strlen_zero(args.exten)) {
ast_log(LOG_WARNING, "A context and extension are required for PERIODIC_HOOK().\n");
return -1;
}
ast_debug(1, "hook to %s@%s enabled on %s with interval of %u seconds\n",
args.exten, args.context, ast_channel_name(chan), interval);
return init_hook(chan, args.context, args.exten, interval, hook_id);
}
static int hook_off(struct ast_channel *chan, const char *hook_id)
{
struct ast_datastore *datastore;
struct hook_state *state;
if (ast_strlen_zero(hook_id)) {
return -1;
}
ast_channel_lock(chan);
if (!(datastore = ast_channel_datastore_find(chan, &hook_datastore, hook_id))) {
ast_log(LOG_WARNING, "Hook with ID '%s' not found on channel '%s'\n", hook_id,
ast_channel_name(chan));
ast_channel_unlock(chan);
return -1;
}
state = datastore->data;
state->disabled = 1;
ast_channel_unlock(chan);
return 0;
}
static int hook_read(struct ast_channel *chan, const char *cmd, char *data,
char *buf, size_t len)
{
unsigned int hook_id;
if (!chan) {
return -1;
}
hook_id = (unsigned int) ast_atomic_fetchadd_int((int *) &global_hook_id, 1);
snprintf(buf, len, "%u", hook_id);
return hook_on(chan, data, hook_id);
}
static int hook_re_enable(struct ast_channel *chan, const char *uid)
{
struct ast_datastore *datastore;
struct hook_state *state;
if (ast_strlen_zero(uid)) {
return -1;
}
ast_channel_lock(chan);
if (!(datastore = ast_channel_datastore_find(chan, &hook_datastore, uid))) {
ast_log(LOG_WARNING, "Hook with ID '%s' not found on '%s'\n",
uid, ast_channel_name(chan));
ast_channel_unlock(chan);
return -1;
}
state = datastore->data;
state->disabled = 0;
ast_channel_unlock(chan);
return 0;
}
static int hook_write(struct ast_channel *chan, const char *cmd, char *data,
const char *value)
{
int res;
if (!chan) {
return -1;
}
if (ast_false(value)) {
res = hook_off(chan, data);
} else if (ast_true(value)) {
res = hook_re_enable(chan, data);
} else {
ast_log(LOG_WARNING, "Invalid value for PERIODIC_HOOK function: '%s'\n", value);
res = -1;
}
return res;
}
static struct ast_custom_function hook_function = {
.name = "PERIODIC_HOOK",
.read = hook_read,
.write = hook_write,
};
static int unload_module(void)
{
ast_context_destroy(NULL, AST_MODULE);
ast_custom_function_unregister(&hook_function);
return 0;
}
static int load_module(void)
{
int res;
if (!ast_context_find_or_create(NULL, NULL, context_name, AST_MODULE)) {
ast_log(LOG_ERROR, "Failed to create %s dialplan context.\n", context_name);
return AST_MODULE_LOAD_DECLINE;
}
/*
* Based on a handy recipe from the Asterisk Cookbook.
*/
res = ast_add_extension(context_name, 1, exten_name, 1, "", "",
"Set", "EncodedChannel=${CUT(HOOK_CHANNEL,-,1-2)}",
NULL, AST_MODULE);
res |= ast_add_extension(context_name, 1, exten_name, 2, "", "",
"Set", "GROUP_NAME=${EncodedChannel}${HOOK_ID}",
NULL, AST_MODULE);
res |= ast_add_extension(context_name, 1, exten_name, 3, "", "",
"Set", "GROUP(periodic-hook)=${GROUP_NAME}",
NULL, AST_MODULE);
res |= ast_add_extension(context_name, 1, exten_name, 4, "", "", "ExecIf",
"$[${GROUP_COUNT(${GROUP_NAME}@periodic-hook)} > 1]?Hangup()",
NULL, AST_MODULE);
res |= ast_add_extension(context_name, 1, exten_name, 5, "", "",
"Set", "ChannelToSpy=${URIDECODE(${EncodedChannel})}",
NULL, AST_MODULE);
res |= ast_add_extension(context_name, 1, exten_name, 6, "", "",
"ChanSpy", "${ChannelToSpy},qEB", NULL, AST_MODULE);
res |= ast_add_extension(context_name, 1, beep_exten, 1, "", "",
"Answer", "", NULL, AST_MODULE);
res |= ast_add_extension(context_name, 1, beep_exten, 2, "", "",
"Playback", "beep", NULL, AST_MODULE);
res |= ast_custom_function_register_escalating(&hook_function, AST_CFE_BOTH);
if (res) {
unload_module();
return AST_MODULE_LOAD_DECLINE;
}
return AST_MODULE_LOAD_SUCCESS;
}
int AST_OPTIONAL_API_NAME(ast_beep_start)(struct ast_channel *chan,
unsigned int interval, char *beep_id, size_t len)
{
char args[AST_MAX_EXTENSION + AST_MAX_CONTEXT + 32];
snprintf(args, sizeof(args), "%s,%s,%u",
context_name, beep_exten, interval);
if (hook_read(chan, NULL, args, beep_id, len)) {
ast_log(LOG_WARNING, "Failed to enable periodic beep.\n");
return -1;
}
return 0;
}
int AST_OPTIONAL_API_NAME(ast_beep_stop)(struct ast_channel *chan, const char *beep_id)
{
return hook_write(chan, NULL, (char *) beep_id, "off");
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS, "Periodic dialplan hooks.",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
.requires = "app_chanspy,func_cut,func_groupcount,func_uri",
);