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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2015, Digium, Inc.
*
* Matt Jordan <mjordan@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 Function that intercepts HOLD frames from channels and raises events
*
* \author Matt Jordan <mjordan@digium.com>
*
* \ingroup functions
*/
/*** MODULEINFO
<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/frame.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_channels.h"
/*** DOCUMENTATION
<function name="HOLD_INTERCEPT" language="en_US">
<synopsis>
Intercepts hold frames on a channel and raises an event instead of passing the frame on
</synopsis>
<syntax>
<parameter name="action" required="true">
<optionlist>
<option name="remove">
<para>W/O. Removes the hold interception function.</para>
</option>
<option name="set">
<para>W/O. Enable hold interception on the channel. When
enabled, the channel will intercept any hold action that
is signalled from the device, and instead simply raise an
event (AMI/ARI) indicating that the channel wanted to put other
parties on hold.</para>
</option>
</optionlist>
</parameter>
</syntax>
</function>
***/
/*! \brief Private data structure used with the function's datastore */
struct hold_intercept_data {
int framehook_id;
};
/*! \brief The channel datastore the function uses to store state */
static const struct ast_datastore_info hold_intercept_datastore = {
.type = "hold_intercept",
};
/*! \internal \brief Disable hold interception on the channel */
static int remove_hold_intercept(struct ast_channel *chan)
{
struct ast_datastore *datastore = NULL;
struct hold_intercept_data *data;
SCOPED_CHANNELLOCK(chan_lock, chan);
datastore = ast_channel_datastore_find(chan, &hold_intercept_datastore, NULL);
if (!datastore) {
ast_log(AST_LOG_WARNING, "Cannot remove HOLD_INTERCEPT from %s: HOLD_INTERCEPT not currently enabled\n",
ast_channel_name(chan));
return -1;
}
data = datastore->data;
if (ast_framehook_detach(chan, data->framehook_id)) {
ast_log(AST_LOG_WARNING, "Failed to remove HOLD_INTERCEPT framehook from channel %s\n",
ast_channel_name(chan));
return -1;
}
if (ast_channel_datastore_remove(chan, datastore)) {
ast_log(AST_LOG_WARNING, "Failed to remove HOLD_INTERCEPT datastore from channel %s\n",
ast_channel_name(chan));
return -1;
}
ast_datastore_free(datastore);
return 0;
}
/*! \brief Frame hook that is called to intercept hold/unhold */
static struct ast_frame *hold_intercept_framehook(struct ast_channel *chan,
struct ast_frame *f, enum ast_framehook_event event, void *data)
{
int frame_type;
if (!f || (event != AST_FRAMEHOOK_EVENT_WRITE)) {
return f;
}
if (f->frametype != AST_FRAME_CONTROL) {
return f;
}
frame_type = f->subclass.integer;
if (frame_type != AST_CONTROL_HOLD && frame_type != AST_CONTROL_UNHOLD) {
return f;
}
/* Munch munch */
ast_frfree(f);
f = &ast_null_frame;
ast_channel_publish_cached_blob(chan,
frame_type == AST_CONTROL_HOLD ? ast_channel_hold_type() : ast_channel_unhold_type(),
NULL);
return f;
}
/*! \brief Callback function which informs upstream if we are consuming a frame of a specific type */
static int hold_intercept_framehook_consume(void *data, enum ast_frame_type type)
{
return (type == AST_FRAME_CONTROL ? 1 : 0);
}
/*! \internal \brief Enable hold interception on the channel */
static int set_hold_intercept(struct ast_channel *chan)
{
struct ast_datastore *datastore;
struct hold_intercept_data *data;
static struct ast_framehook_interface hold_framehook_interface = {
.version = AST_FRAMEHOOK_INTERFACE_VERSION,
.event_cb = hold_intercept_framehook,
.consume_cb = hold_intercept_framehook_consume,
.disable_inheritance = 1,
};
SCOPED_CHANNELLOCK(chan_lock, chan);
datastore = ast_channel_datastore_find(chan, &hold_intercept_datastore, NULL);
if (datastore) {
ast_log(AST_LOG_WARNING, "HOLD_INTERCEPT already set on '%s'\n",
ast_channel_name(chan));
return 0;
}
datastore = ast_datastore_alloc(&hold_intercept_datastore, NULL);
if (!datastore) {
return -1;
}
data = ast_calloc(1, sizeof(*data));
if (!data) {
ast_datastore_free(datastore);
return -1;
}
data->framehook_id = ast_framehook_attach(chan, &hold_framehook_interface);
if (data->framehook_id < 0) {
ast_log(AST_LOG_WARNING, "Failed to attach HOLD_INTERCEPT framehook to '%s'\n",
ast_channel_name(chan));
ast_datastore_free(datastore);
ast_free(data);
return -1;
}
datastore->data = data;
ast_channel_datastore_add(chan, datastore);
return 0;
}
/*! \internal \brief HOLD_INTERCEPT write function callback */
static int hold_intercept_fn_write(struct ast_channel *chan, const char *function,
char *data, const char *value)
{
int res;
if (!chan) {
return -1;
}
if (ast_strlen_zero(data)) {
ast_log(AST_LOG_WARNING, "HOLD_INTERCEPT requires an argument\n");
return -1;
}
if (!strcasecmp(data, "set")) {
res = set_hold_intercept(chan);
} else if (!strcasecmp(data, "remove")) {
res = remove_hold_intercept(chan);
} else {
ast_log(AST_LOG_WARNING, "HOLD_INTERCEPT: unknown option %s\n", data);
res = -1;
}
return res;
}
/*! \brief Definition of the HOLD_INTERCEPT function */
static struct ast_custom_function hold_intercept_function = {
.name = "HOLD_INTERCEPT",
.write = hold_intercept_fn_write,
};
/*! \internal \brief Unload the module */
static int unload_module(void)
{
return ast_custom_function_unregister(&hold_intercept_function);
}
/*! \internal \brief Load the module */
static int load_module(void)
{
return ast_custom_function_register(&hold_intercept_function) ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
}
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Hold interception dialplan function");
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