asterisk/main/pickup.c

407 lines
12 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2013, Digium, Inc.
* Copyright (C) 2012, Russell Bryant
*
* 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 Routines implementing call pickup
*
* \author Matt Jordan <mjordan@digium.com>
*/
/*!
* \li Call pickup uses the configuration file \ref features.conf
* \addtogroup configuration_file Configuration Files
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
/*** DOCUMENTATION
<managerEvent language="en_US" name="Pickup">
<managerEventInstance class="EVENT_FLAG_CALL">
<synopsis>Raised when a call pickup occurs.</synopsis>
<syntax>
<channel_snapshot/>
<channel_snapshot prefix="Target"/>
</syntax>
</managerEventInstance>
</managerEvent>
***/
#include "asterisk.h"
#include "asterisk/pickup.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"
#include "asterisk/callerid.h"
#include "asterisk/causes.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/features_config.h"
static struct ast_manager_event_blob *call_pickup_to_ami(struct stasis_message *message);
STASIS_MESSAGE_TYPE_DEFN(
ast_call_pickup_type,
.to_ami = call_pickup_to_ami);
/*!
* The presence of this datastore on the channel indicates that
* someone is attemting to pickup or has picked up the channel.
* The purpose is to prevent a race between two channels
* attempting to pickup the same channel.
*/
static const struct ast_datastore_info pickup_active = {
.type = "pickup-active",
};
int ast_can_pickup(struct ast_channel *chan)
{
if (!ast_channel_pbx(chan) && !ast_channel_masq(chan) && !ast_test_flag(ast_channel_flags(chan), AST_FLAG_ZOMBIE)
&& (ast_channel_state(chan) == AST_STATE_RINGING
|| ast_channel_state(chan) == AST_STATE_RING
/*
* Check the down state as well because some SIP devices do not
* give 180 ringing when they can just give 183 session progress
* instead. Issue 14005. (Some ISDN switches as well for that
* matter.)
*/
|| ast_channel_state(chan) == AST_STATE_DOWN)
&& !ast_channel_datastore_find(chan, &pickup_active, NULL)) {
return 1;
}
return 0;
}
static int find_channel_by_group(void *obj, void *arg, void *data, int flags)
{
struct ast_channel *target = obj; /*!< Potential pickup target */
struct ast_channel *chan = arg; /*!< Channel wanting to pickup call */
if (chan == target) {
return 0;
}
ast_channel_lock(target);
if (ast_can_pickup(target)) {
/* Lock both channels. */
while (ast_channel_trylock(chan)) {
ast_channel_unlock(target);
sched_yield();
ast_channel_lock(target);
}
/*
* Both callgroup and namedcallgroup pickup variants are
* matched independently. Checking for named group match is
* done last since it's a more expensive operation.
*/
if ((ast_channel_pickupgroup(chan) & ast_channel_callgroup(target))
|| (ast_namedgroups_intersect(ast_channel_named_pickupgroups(chan),
ast_channel_named_callgroups(target)))) {
struct ao2_container *candidates = data;/*!< Candidate channels found. */
/* This is a candidate to pickup */
ao2_link(candidates, target);
}
ast_channel_unlock(chan);
}
ast_channel_unlock(target);
return 0;
}
struct ast_channel *ast_pickup_find_by_group(struct ast_channel *chan)
{
struct ao2_container *candidates;/*!< Candidate channels found to pickup. */
struct ast_channel *target;/*!< Potential pickup target */
candidates = ao2_container_alloc_list(AO2_ALLOC_OPT_LOCK_NOLOCK, 0, NULL, NULL);
if (!candidates) {
return NULL;
}
/* Find all candidate targets by group. */
ast_channel_callback(find_channel_by_group, chan, candidates, 0);
/* Find the oldest pickup target candidate */
target = NULL;
for (;;) {
struct ast_channel *candidate;/*!< Potential new older target */
struct ao2_iterator iter;
iter = ao2_iterator_init(candidates, 0);
while ((candidate = ao2_iterator_next(&iter))) {
if (!target) {
/* First target. */
target = candidate;
continue;
}
if (ast_tvcmp(ast_channel_creationtime(candidate), ast_channel_creationtime(target)) < 0) {
/* We have a new target. */
ast_channel_unref(target);
target = candidate;
continue;
}
ast_channel_unref(candidate);
}
ao2_iterator_destroy(&iter);
if (!target) {
/* No candidates found. */
break;
}
/* The found channel must be locked and ref'd. */
ast_channel_lock(target);
/* Recheck pickup ability */
if (ast_can_pickup(target)) {
/* This is the channel to pickup. */
break;
}
/* Someone else picked it up or the call went away. */
ast_channel_unlock(target);
ao2_unlink(candidates, target);
target = ast_channel_unref(target);
}
ao2_ref(candidates, -1);
return target;
}
/*!
* \brief Pickup a call
*
* Walk list of channels, checking it is not itself, channel is pbx one,
* check that the callgroup for both channels are the same and the channel is ringing.
* Answer calling channel, flag channel as answered on queue, masq channels together.
*/
int ast_pickup_call(struct ast_channel *chan)
{
struct ast_channel *target;/*!< Potential pickup target */
int res = -1;
RAII_VAR(struct ast_features_pickup_config *, pickup_cfg, NULL, ao2_cleanup);
const char *pickup_sound;
const char *fail_sound;
ast_debug(1, "Pickup attempt by %s\n", ast_channel_name(chan));
ast_channel_lock(chan);
pickup_cfg = ast_get_chan_features_pickup_config(chan);
if (!pickup_cfg) {
ast_log(LOG_ERROR, "Unable to retrieve pickup configuration. Unable to play pickup sounds\n");
}
pickup_sound = ast_strdupa(pickup_cfg ? pickup_cfg->pickupsound : "");
fail_sound = ast_strdupa(pickup_cfg ? pickup_cfg->pickupfailsound : "");
ast_channel_unlock(chan);
/* The found channel is already locked. */
target = ast_pickup_find_by_group(chan);
if (target) {
ast_log(LOG_NOTICE, "Pickup %s attempt by %s\n", ast_channel_name(target), ast_channel_name(chan));
res = ast_do_pickup(chan, target);
ast_channel_unlock(target);
if (!res) {
if (!ast_strlen_zero(pickup_sound)) {
pbx_builtin_setvar_helper(target, "BRIDGE_PLAY_SOUND", pickup_sound);
}
} else {
ast_log(LOG_WARNING, "Pickup %s failed by %s\n", ast_channel_name(target), ast_channel_name(chan));
}
target = ast_channel_unref(target);
}
if (res < 0) {
ast_debug(1, "No call pickup possible... for %s\n", ast_channel_name(chan));
if (!ast_strlen_zero(fail_sound)) {
ast_answer(chan);
ast_stream_and_wait(chan, fail_sound, "");
}
}
return res;
}
static struct ast_manager_event_blob *call_pickup_to_ami(struct stasis_message *message)
{
struct ast_multi_channel_blob *contents = stasis_message_data(message);
struct ast_channel_snapshot *chan;
struct ast_channel_snapshot *target;
struct ast_manager_event_blob *res;
RAII_VAR(struct ast_str *, channel_str, NULL, ast_free);
RAII_VAR(struct ast_str *, target_str, NULL, ast_free);
chan = ast_multi_channel_blob_get_channel(contents, "channel");
target = ast_multi_channel_blob_get_channel(contents, "target");
ast_assert(chan != NULL && target != NULL);
if (!(channel_str = ast_manager_build_channel_state_string(chan))) {
return NULL;
}
if (!(target_str = ast_manager_build_channel_state_string_prefix(target, "Target"))) {
return NULL;
}
res = ast_manager_event_blob_create(EVENT_FLAG_CALL, "Pickup",
"%s"
"%s",
ast_str_buffer(channel_str),
ast_str_buffer(target_str));
return res;
}
static int send_call_pickup_stasis_message(struct ast_channel *picking_up, struct ast_channel_snapshot *chan, struct ast_channel_snapshot *target)
{
RAII_VAR(struct ast_multi_channel_blob *, pickup_payload, NULL, ao2_cleanup);
RAII_VAR(struct stasis_message *, msg, NULL, ao2_cleanup);
if (!ast_call_pickup_type()) {
return -1;
}
if (!(pickup_payload = ast_multi_channel_blob_create(ast_json_null()))) {
return -1;
}
ast_multi_channel_blob_add_channel(pickup_payload, "channel", chan);
ast_multi_channel_blob_add_channel(pickup_payload, "target", target);
if (!(msg = stasis_message_create(ast_call_pickup_type(), pickup_payload))) {
return -1;
}
stasis_publish(ast_channel_topic(picking_up), msg);
return 0;
}
int ast_do_pickup(struct ast_channel *chan, struct ast_channel *target)
{
struct ast_party_connected_line connected_caller;
struct ast_datastore *ds_pickup;
const char *chan_name;/*!< A masquerade changes channel names. */
const char *target_name;/*!< A masquerade changes channel names. */
int res = -1;
RAII_VAR(struct ast_channel_snapshot *, chan_snapshot, NULL, ao2_cleanup);
RAII_VAR(struct ast_channel_snapshot *, target_snapshot, NULL, ao2_cleanup);
target_name = ast_strdupa(ast_channel_name(target));
ast_debug(1, "Call pickup on '%s' by '%s'\n", target_name, ast_channel_name(chan));
/* Mark the target to block any call pickup race. */
ds_pickup = ast_datastore_alloc(&pickup_active, NULL);
if (!ds_pickup) {
ast_log(LOG_WARNING,
"Unable to create channel datastore on '%s' for call pickup\n", target_name);
return -1;
}
ast_channel_datastore_add(target, ds_pickup);
ast_party_connected_line_init(&connected_caller);
ast_party_connected_line_copy(&connected_caller, ast_channel_connected(target));
ast_channel_unlock(target);/* The pickup race is avoided so we do not need the lock anymore. */
/* Reset any earlier private connected id representation */
ast_party_id_reset(&connected_caller.priv);
connected_caller.source = AST_CONNECTED_LINE_UPDATE_SOURCE_ANSWER;
if (ast_channel_connected_line_sub(NULL, chan, &connected_caller, 0) &&
ast_channel_connected_line_macro(NULL, chan, &connected_caller, 0, 0)) {
ast_channel_update_connected_line(chan, &connected_caller, NULL);
}
ast_party_connected_line_free(&connected_caller);
ast_channel_lock(chan);
chan_name = ast_strdupa(ast_channel_name(chan));
ast_connected_line_copy_from_caller(&connected_caller, ast_channel_caller(chan));
ast_channel_unlock(chan);
connected_caller.source = AST_CONNECTED_LINE_UPDATE_SOURCE_ANSWER;
if (ast_answer(chan)) {
ast_log(LOG_WARNING, "Unable to answer '%s'\n", chan_name);
goto pickup_failed;
}
if (ast_queue_control(chan, AST_CONTROL_ANSWER)) {
ast_log(LOG_WARNING, "Unable to queue answer on '%s'\n", chan_name);
goto pickup_failed;
}
ast_channel_queue_connected_line_update(chan, &connected_caller, NULL);
/* setting the HANGUPCAUSE so the ringing channel knows this call was not a missed call */
ast_channel_hangupcause_set(chan, AST_CAUSE_ANSWERED_ELSEWHERE);
ast_channel_lock(chan);
chan_snapshot = ast_channel_snapshot_create(chan);
ast_channel_unlock(chan);
if (!chan_snapshot) {
goto pickup_failed;
}
target_snapshot = ast_channel_snapshot_get_latest(ast_channel_uniqueid(target));
if (!target_snapshot) {
goto pickup_failed;
}
if (ast_channel_move(target, chan)) {
ast_log(LOG_WARNING, "Unable to complete call pickup of '%s' with '%s'\n",
chan_name, target_name);
goto pickup_failed;
}
/* target points to the channel that did the pickup at this point, so use that channel's topic instead of chan */
send_call_pickup_stasis_message(target, chan_snapshot, target_snapshot);
res = 0;
pickup_failed:
ast_channel_lock(target);
if (!ast_channel_datastore_remove(target, ds_pickup)) {
ast_datastore_free(ds_pickup);
}
ast_party_connected_line_free(&connected_caller);
return res;
}
/*!
* \internal
* \brief Clean up resources on Asterisk shutdown
*/
static void pickup_shutdown(void)
{
STASIS_MESSAGE_TYPE_CLEANUP(ast_call_pickup_type);
}
int ast_pickup_init(void)
{
STASIS_MESSAGE_TYPE_INIT(ast_call_pickup_type);
ast_register_cleanup(pickup_shutdown);
return 0;
}