features.c

Go to the documentation of this file.

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2012, Digium, Inc.
 * Copyright (C) 2012, Russell Bryant
 *
 * Mark Spencer <[email protected]>
 *
 * 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 features as call pickup, parking and transfer
 *
 * \author Mark Spencer <[email protected]>
 */

/*! \li \ref features.c uses the configuration file \ref features.conf
 * \addtogroup configuration_file Configuration Files
 */

/*!
 * \page features.conf features.conf
 * \verbinclude features.conf.sample
 */

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

#include "asterisk.h"

#include "asterisk/_private.h"
#include "features_config.h"

#include <pthread.h>
#include <signal.h>
#include <sys/time.h>
#include <signal.h>
#include <netinet/in.h>

#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/causes.h"
#include "asterisk/module.h"
#include "asterisk/translate.h"
#include "asterisk/app.h"
#include "asterisk/say.h"
#include "asterisk/features.h"
#include "asterisk/musiconhold.h"
#include "asterisk/config.h"
#include "asterisk/cli.h"
#include "asterisk/manager.h"
#include "asterisk/utils.h"
#include "asterisk/devicestate.h"
#include "asterisk/audiohook.h"
#include "asterisk/global_datastores.h"
#include "asterisk/astobj2.h"
#include "asterisk/test.h"
#include "asterisk/bridge.h"
#include "asterisk/bridge_features.h"
#include "asterisk/bridge_basic.h"
#include "asterisk/bridge_after.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/features_config.h"
#include "asterisk/max_forwards.h"
#include "asterisk/stream.h"

/*** DOCUMENTATION
 <application name="Bridge" language="en_US">
 <synopsis>
 Bridge two channels.
 </synopsis>
 <syntax>
 <parameter name="channel" required="true">
 <para>The current channel is bridged to the channel
 identified by the channel name, channel name prefix, or channel
 uniqueid.</para>
 </parameter>
 <parameter name="options">
 <optionlist>
 <option name="p">
 <para>Play a courtesy tone to <replaceable>channel</replaceable>.</para>
 </option>
 <option name="F" argsep="^">
 <argument name="context" required="false" />
 <argument name="exten" required="false" />
 <argument name="priority" required="true" />
 <para>When the bridger hangs up, transfer the <emphasis>bridged</emphasis> party
 to the specified destination and <emphasis>start</emphasis> execution at that location.</para>
 <note>
 <para>Any channel variables you want the called channel to inherit from the caller channel must be
 prefixed with one or two underbars ('_').</para>
 </note>
 <note>
 <para>This option will override the 'x' option</para>
 </note>
 </option>
 <option name="F">
 <para>When the bridger hangs up, transfer the <emphasis>bridged</emphasis> party
 to the next priority of the current extension and <emphasis>start</emphasis> execution
 at that location.</para>
 <note>
 <para>Any channel variables you want the called channel to inherit from the caller channel must be
 prefixed with one or two underbars ('_').</para>
 </note>
 <note>
 <para>Using this option from a Macro() or GoSub() might not make sense as there would be no return points.</para>
 </note>
 <note>
 <para>This option will override the 'x' option</para>
 </note>
 </option>

 <option name="h">
 <para>Allow the called party to hang up by sending the
 <replaceable>*</replaceable> DTMF digit.</para>
 </option>
 <option name="H">
 <para>Allow the calling party to hang up by pressing the
 <replaceable>*</replaceable> DTMF digit.</para>
 </option>
 <option name="k">
 <para>Allow the called party to enable parking of the call by sending
 the DTMF sequence defined for call parking in <filename>features.conf</filename>.</para>
 </option>
 <option name="K">
 <para>Allow the calling party to enable parking of the call by sending
 the DTMF sequence defined for call parking in <filename>features.conf</filename>.</para>
 </option>
 <option name="L(x[:y][:z])">
 <para>Limit the call to <replaceable>x</replaceable> ms. Play a warning
 when <replaceable>y</replaceable> ms are left. Repeat the warning every
 <replaceable>z</replaceable> ms. The following special variables can be
 used with this option:</para>
 <variablelist>
 <variable name="LIMIT_PLAYAUDIO_CALLER">
 <para>Play sounds to the caller. yes|no (default yes)</para>
 </variable>
 <variable name="LIMIT_PLAYAUDIO_CALLEE">
 <para>Play sounds to the callee. yes|no</para>
 </variable>
 <variable name="LIMIT_TIMEOUT_FILE">
 <para>File to play when time is up.</para>
 </variable>
 <variable name="LIMIT_CONNECT_FILE">
 <para>File to play when call begins.</para>
 </variable>
 <variable name="LIMIT_WARNING_FILE">
 <para>File to play as warning if <replaceable>y</replaceable> is
 defined. The default is to say the time remaining.</para>
 </variable>
 </variablelist>
 </option>
 <option name="S(x)">
 <para>Hang up the call after <replaceable>x</replaceable> seconds *after* the called party has answered the call.</para>
 </option>
 <option name="t">
 <para>Allow the called party to transfer the calling party by sending the
 DTMF sequence defined in <filename>features.conf</filename>.</para>
 </option>
 <option name="T">
 <para>Allow the calling party to transfer the called party by sending the
 DTMF sequence defined in <filename>features.conf</filename>.</para>
 </option>
 <option name="w">
 <para>Allow the called party to enable recording of the call by sending
 the DTMF sequence defined for one-touch recording in <filename>features.conf</filename>.</para>
 </option>
 <option name="W">
 <para>Allow the calling party to enable recording of the call by sending
 the DTMF sequence defined for one-touch recording in <filename>features.conf</filename>.</para>
 </option>
 <option name="x">
 <para>Cause the called party to be hung up after the bridge, instead of being
 restarted in the dialplan.</para>
 </option>
 </optionlist>
 </parameter>
 </syntax>
 <description>
 <para>Allows the ability to bridge two channels via the dialplan.</para>
 <para>This application sets the following channel variable upon completion:</para>
 <variablelist>
 <variable name="BRIDGERESULT">
 <para>The result of the bridge attempt as a text string.</para>
 <value name="SUCCESS" />
 <value name="FAILURE" />
 <value name="LOOP" />
 <value name="NONEXISTENT" />
 </variable>
 </variablelist>
 </description>
 <see-also>
 <ref type="manager">Bridge</ref>
 <ref type="managerEvent">BridgeCreate</ref>
 <ref type="managerEvent">BridgeEnter</ref>
 </see-also>
 </application>
 <manager name="Bridge" language="en_US">
 <synopsis>
 Bridge two channels already in the PBX.
 </synopsis>
 <syntax>
 <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
 <parameter name="Channel1" required="true">
 <para>Channel to Bridge to Channel2.</para>
 </parameter>
 <parameter name="Channel2" required="true">
 <para>Channel to Bridge to Channel1.</para>
 </parameter>
 <parameter name="Tone">
 <para>Play courtesy tone to Channel 2.</para>
 <enumlist>
 <enum name="no" />
 <enum name="Channel1" />
 <enum name="Channel2" />
 <enum name="Both" />
 </enumlist>
 </parameter>
 </syntax>
 <description>
 <para>Bridge together two channels already in the PBX.</para>
 </description>
 <see-also>
 <ref type="application">Bridge</ref>
 <ref type="managerEvent">BridgeCreate</ref>
 <ref type="managerEvent">BridgeEnter</ref>
 <ref type="manager">BridgeDestroy</ref>
 <ref type="manager">BridgeInfo</ref>
 <ref type="manager">BridgeKick</ref>
 <ref type="manager">BridgeList</ref>
 </see-also>
 </manager>
 ***/

typedef enum {
 FEATURE_INTERPRET_DETECT, /* Used by ast_feature_detect */
 FEATURE_INTERPRET_DO, /* Used by feature_interpret */
 FEATURE_INTERPRET_CHECK, /* Used by feature_check */
} feature_interpret_op;

struct ast_dial_features {
 /*! Channel's feature flags. */
 struct ast_flags my_features;
 /*! Bridge peer's feature flags. */
 struct ast_flags peer_features;
};

static void *dial_features_duplicate(void *data)
{
 struct ast_dial_features *df = data, *df_copy;

 if (!(df_copy = ast_calloc(1, sizeof(*df)))) {
 return NULL;
 }

 memcpy(df_copy, df, sizeof(*df));

 return df_copy;
}

static const struct ast_datastore_info dial_features_info = {
 .type = "dial-features",
 .destroy = ast_free_ptr,
 .duplicate = dial_features_duplicate,
};

/*!
 * \internal
 * \brief Set the features datastore if it doesn't exist.
 *
 * \param chan Channel to add features datastore
 * \param my_features The channel's feature flags
 * \param peer_features The channel's bridge peer feature flags
 *
 * \retval TRUE if features datastore already existed.
 */
static int add_features_datastore(struct ast_channel *chan, const struct ast_flags *my_features, const struct ast_flags *peer_features)
{
 struct ast_datastore *datastore;
 struct ast_dial_features *dialfeatures;

 ast_channel_lock(chan);
 datastore = ast_channel_datastore_find(chan, &dial_features_info, NULL);
 ast_channel_unlock(chan);
 if (datastore) {
 /* Already exists. */
 return 1;
 }

 /* Create a new datastore with specified feature flags. */
 datastore = ast_datastore_alloc(&dial_features_info, NULL);
 if (!datastore) {
 ast_log(LOG_WARNING, "Unable to create channel features datastore.\n");
 return 0;
 }
 dialfeatures = ast_calloc(1, sizeof(*dialfeatures));
 if (!dialfeatures) {
 ast_log(LOG_WARNING, "Unable to allocate memory for feature flags.\n");
 ast_datastore_free(datastore);
 return 0;
 }
 ast_copy_flags(&dialfeatures->my_features, my_features, AST_FLAGS_ALL);
 ast_copy_flags(&dialfeatures->peer_features, peer_features, AST_FLAGS_ALL);
 datastore->inheritance = DATASTORE_INHERIT_FOREVER;
 datastore->data = dialfeatures;
 ast_channel_lock(chan);
 ast_channel_datastore_add(chan, datastore);
 ast_channel_unlock(chan);
 return 0;
}

struct ast_bridge_thread_obj
{
 struct ast_bridge_config bconfig;
 struct ast_channel *chan;
 struct ast_channel *peer;
 unsigned int return_to_pbx:1;
};

static void set_config_flags(struct ast_channel *chan, struct ast_bridge_config *config)
{
 ast_clear_flag(config, AST_FLAGS_ALL);

 if (ast_test_flag(&config->features_caller, AST_FEATURE_DTMF_MASK)) {
 ast_set_flag(config, AST_BRIDGE_DTMF_CHANNEL_0);
 }
 if (ast_test_flag(&config->features_callee, AST_FEATURE_DTMF_MASK)) {
 ast_set_flag(config, AST_BRIDGE_DTMF_CHANNEL_1);
 }

 if (!(ast_test_flag(config, AST_BRIDGE_DTMF_CHANNEL_0) && ast_test_flag(config, AST_BRIDGE_DTMF_CHANNEL_1))) {
 RAII_VAR(struct ao2_container *, applicationmap, NULL, ao2_cleanup);

 ast_channel_lock(chan);
 applicationmap = ast_get_chan_applicationmap(chan);
 ast_channel_unlock(chan);

 if (!applicationmap) {
 return;
 }

 /* If an applicationmap exists for this channel at all, then the channel needs the DTMF flag set */
 ast_set_flag(config, AST_BRIDGE_DTMF_CHANNEL_0);
 }
}

void ast_channel_log(char *title, struct ast_channel *chan);

void ast_channel_log(char *title, struct ast_channel *chan) /* for debug, this is handy enough to justify keeping it in the source */
{
 ast_log(LOG_NOTICE, "______ %s (%lx)______\n", title, (unsigned long) chan);
 ast_log(LOG_NOTICE, "CHAN: name: %s; appl: %s; data: %s; contxt: %s; exten: %s; pri: %d;\n",
 ast_channel_name(chan), ast_channel_appl(chan), ast_channel_data(chan),
 ast_channel_context(chan), ast_channel_exten(chan), ast_channel_priority(chan));
 ast_log(LOG_NOTICE, "CHAN: acctcode: %s; dialcontext: %s; amaflags: %x; maccontxt: %s; macexten: %s; macpri: %d;\n",
 ast_channel_accountcode(chan), ast_channel_dialcontext(chan), ast_channel_amaflags(chan),
 ast_channel_macrocontext(chan), ast_channel_macroexten(chan), ast_channel_macropriority(chan));
 ast_log(LOG_NOTICE, "CHAN: masq: %p; masqr: %p; uniqueID: %s; linkedID:%s\n",
 ast_channel_masq(chan), ast_channel_masqr(chan),
 ast_channel_uniqueid(chan), ast_channel_linkedid(chan));
 if (ast_channel_masqr(chan)) {
 ast_log(LOG_NOTICE, "CHAN: masquerading as: %s; cdr: %p;\n",
 ast_channel_name(ast_channel_masqr(chan)), ast_channel_cdr(ast_channel_masqr(chan)));
 }

 ast_log(LOG_NOTICE, "===== done ====\n");
}

static void set_bridge_features_on_config(struct ast_bridge_config *config, const char *features)
{
 const char *feature;

 if (ast_strlen_zero(features)) {
 return;
 }

 for (feature = features; *feature; feature++) {
 struct ast_flags *party;

 if (isupper(*feature)) {
 party = &config->features_caller;
 } else {
 party = &config->features_callee;
 }

 switch (tolower(*feature)) {
 case 't' :
 ast_set_flag(party, AST_FEATURE_REDIRECT);
 break;
 case 'k' :
 ast_set_flag(party, AST_FEATURE_PARKCALL);
 break;
 case 'h' :
 ast_set_flag(party, AST_FEATURE_DISCONNECT);
 break;
 case 'w' :
 ast_set_flag(party, AST_FEATURE_AUTOMON);
 break;
 case 'x' :
 ast_set_flag(party, AST_FEATURE_AUTOMIXMON);
 break;
 default :
 ast_log(LOG_WARNING, "Skipping unknown feature code '%c'\n", *feature);
 break;
 }
 }
}

static void add_features_datastores(struct ast_channel *caller, struct ast_channel *callee, struct ast_bridge_config *config)
{
 if (add_features_datastore(caller, &config->features_caller, &config->features_callee)) {
 /*
 * If we don't return here, then when we do a builtin_atxfer we
 * will copy the disconnect flags over from the atxfer to the
 * callee (Party C).
 */
 return;
 }

 add_features_datastore(callee, &config->features_callee, &config->features_caller);
}

static void bridge_config_set_limits_warning_values(struct ast_bridge_config *config, struct ast_bridge_features_limits *limits)
{
 if (config->end_sound) {
 ast_string_field_set(limits, duration_sound, config->end_sound);
 }

 if (config->warning_sound) {
 ast_string_field_set(limits, warning_sound, config->warning_sound);
 }

 if (config->start_sound) {
 ast_string_field_set(limits, connect_sound, config->start_sound);
 }

 limits->frequency = config->warning_freq;
 limits->warning = config->play_warning;
}

/*!
 * \internal brief Setup limit hook structures on calls that need limits
 *
 * \param config ast_bridge_config which provides the limit data
 * \param caller_limits pointer to an ast_bridge_features_limits struct which will store the caller side limits
 * \param callee_limits pointer to an ast_bridge_features_limits struct which will store the callee side limits
 */
static void bridge_config_set_limits(struct ast_bridge_config *config, struct ast_bridge_features_limits *caller_limits, struct ast_bridge_features_limits *callee_limits)
{
 if (ast_test_flag(&config->features_caller, AST_FEATURE_PLAY_WARNING)) {
 bridge_config_set_limits_warning_values(config, caller_limits);
 }

 if (ast_test_flag(&config->features_callee, AST_FEATURE_PLAY_WARNING)) {
 bridge_config_set_limits_warning_values(config, callee_limits);
 }

 caller_limits->duration = config->timelimit;
 callee_limits->duration = config->timelimit;
}

/*!
 * \internal
 * \brief Check if Monitor needs to be started on a channel.
 * \since 12.0.0
 *
 * \param chan The bridge considers this channel the caller.
 * \param peer The bridge considers this channel the callee.
 *
 * \return Nothing
 */
static void bridge_check_monitor(struct ast_channel *chan, struct ast_channel *peer)
{
 const char *value;
 const char *monitor_args = NULL;
 struct ast_channel *monitor_chan = NULL;

 ast_channel_lock(chan);
 value = pbx_builtin_getvar_helper(chan, "AUTO_MONITOR");
 if (!ast_strlen_zero(value)) {
 monitor_args = ast_strdupa(value);
 monitor_chan = chan;
 }
 ast_channel_unlock(chan);
 if (!monitor_chan) {
 ast_channel_lock(peer);
 value = pbx_builtin_getvar_helper(peer, "AUTO_MONITOR");
 if (!ast_strlen_zero(value)) {
 monitor_args = ast_strdupa(value);
 monitor_chan = peer;
 }
 ast_channel_unlock(peer);
 }
 if (monitor_chan) {
 struct ast_app *monitor_app;

 monitor_app = pbx_findapp("Monitor");
 if (monitor_app) {
 pbx_exec(monitor_chan, monitor_app, monitor_args);
 }
 }
}

/*!
 * \internal
 * \brief Send the peer channel on its way on bridge start failure.
 * \since 12.0.0
 *
 * \param chan Chan to put into autoservice.
 * \param peer Chan to send to after bridge goto or run hangup handlers and hangup.
 *
 * \return Nothing
 */
static void bridge_failed_peer_goto(struct ast_channel *chan, struct ast_channel *peer)
{
 if (ast_bridge_setup_after_goto(peer)
 || ast_pbx_start(peer)) {
 ast_autoservice_chan_hangup_peer(chan, peer);
 }
}

static int pre_bridge_setup(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config,
 struct ast_bridge_features *chan_features, struct ast_bridge_features *peer_features)
{
 int res;
 SCOPE_TRACE(1, "%s Peer: %s\n", ast_channel_name(chan), ast_channel_name(peer));

 set_bridge_features_on_config(config, pbx_builtin_getvar_helper(chan, "BRIDGE_FEATURES"));
 add_features_datastores(chan, peer, config);

 /*
 * This is an interesting case. One example is if a ringing
 * channel gets redirected to an extension that picks up a
 * parked call. This will make sure that the call taken out of
 * parking gets told that the channel it just got bridged to is
 * still ringing.
 */
 if (ast_channel_state(chan) == AST_STATE_RINGING
 && ast_channel_visible_indication(peer) != AST_CONTROL_RINGING) {
 ast_indicate(peer, AST_CONTROL_RINGING);
 }

 bridge_check_monitor(chan, peer);

 set_config_flags(chan, config);

 /* Answer if need be */

 res = 0;

 if (ast_channel_state(chan) != AST_STATE_UP) {
 res = ast_raw_answer_with_stream_topology(chan, config->answer_topology);
 if (res != 0) {
 return -1;
 }
 }


#ifdef FOR_DEBUG
 /* show the two channels and cdrs involved in the bridge for debug & devel purposes */
 ast_channel_log("Pre-bridge CHAN Channel info", chan);
 ast_channel_log("Pre-bridge PEER Channel info", peer);
#endif

 res = 0;
 ast_channel_lock(chan);
 ast_max_forwards_reset(chan);
 res |= ast_bridge_features_ds_append(chan, &config->features_caller);
 ast_channel_unlock(chan);
 ast_channel_lock(peer);
 ast_max_forwards_reset(peer);
 res |= ast_bridge_features_ds_append(peer, &config->features_callee);
 ast_channel_unlock(peer);

 if (res) {
 return -1;
 }

 if (config->timelimit) {
 struct ast_bridge_features_limits call_duration_limits_chan;
 struct ast_bridge_features_limits call_duration_limits_peer;
 int abandon_call = 0; /* TRUE if set limits fails so we can abandon the call. */

 if (ast_bridge_features_limits_construct(&call_duration_limits_chan)) {
 ast_log(LOG_ERROR, "Could not construct caller duration limits. Bridge canceled.\n");

 return -1;
 }

 if (ast_bridge_features_limits_construct(&call_duration_limits_peer)) {
 ast_log(LOG_ERROR, "Could not construct callee duration limits. Bridge canceled.\n");
 ast_bridge_features_limits_destroy(&call_duration_limits_chan);

 return -1;
 }

 bridge_config_set_limits(config, &call_duration_limits_chan, &call_duration_limits_peer);

 if (ast_bridge_features_set_limits(chan_features, &call_duration_limits_chan, 0)) {
 abandon_call = 1;
 }
 if (ast_bridge_features_set_limits(peer_features, &call_duration_limits_peer, 0)) {
 abandon_call = 1;
 }

 /* At this point we are done with the limits structs since they have been copied to the individual feature sets. */
 ast_bridge_features_limits_destroy(&call_duration_limits_chan);
 ast_bridge_features_limits_destroy(&call_duration_limits_peer);

 if (abandon_call) {
 ast_log(LOG_ERROR, "Could not set duration limits on one or more sides of the call. Bridge canceled.\n");
 return -1;
 }
 }

 return 0;
}

int ast_bridge_call_with_flags(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config, unsigned int flags)
{
 int res;
 struct ast_bridge *bridge;
 struct ast_bridge_features chan_features;
 struct ast_bridge_features *peer_features;
 SCOPE_TRACE(1, "%s Peer: %s\n", ast_channel_name(chan), ast_channel_name(peer));

 /* Setup features. */
 res = ast_bridge_features_init(&chan_features);
 peer_features = ast_bridge_features_new();
 if (res || !peer_features) {
 ast_bridge_features_destroy(peer_features);
 ast_bridge_features_cleanup(&chan_features);
 bridge_failed_peer_goto(chan, peer);
 return -1;
 }

 if (pre_bridge_setup(chan, peer, config, &chan_features, peer_features)) {
 ast_bridge_features_destroy(peer_features);
 ast_bridge_features_cleanup(&chan_features);
 bridge_failed_peer_goto(chan, peer);
 return -1;
 }

 /* Create bridge */
 bridge = ast_bridge_basic_new();
 if (!bridge) {
 ast_bridge_features_destroy(peer_features);
 ast_bridge_features_cleanup(&chan_features);
 bridge_failed_peer_goto(chan, peer);
 return -1;
 }

 ast_bridge_basic_set_flags(bridge, flags);

 /* Put peer into the bridge */
 if (ast_bridge_impart(bridge, peer, NULL, peer_features,
 AST_BRIDGE_IMPART_CHAN_INDEPENDENT | AST_BRIDGE_IMPART_INHIBIT_JOIN_COLP)) {
 ast_bridge_destroy(bridge, 0);
 ast_bridge_features_cleanup(&chan_features);
 bridge_failed_peer_goto(chan, peer);
 return -1;
 }

 /* Join bridge */
 ast_bridge_join(bridge, chan, NULL, &chan_features, NULL,
 AST_BRIDGE_JOIN_PASS_REFERENCE | AST_BRIDGE_JOIN_INHIBIT_JOIN_COLP);

 /*
 * If the bridge was broken for a hangup that isn't real, then
 * don't run the h extension, because the channel isn't really
 * hung up. This should really only happen with
 * AST_SOFTHANGUP_ASYNCGOTO.
 */
 res = -1;
 ast_channel_lock(chan);
 if (ast_channel_softhangup_internal_flag(chan) & AST_SOFTHANGUP_ASYNCGOTO) {
 res = 0;
 }
 ast_channel_unlock(chan);

 ast_bridge_features_cleanup(&chan_features);

 if (res && config->end_bridge_callback) {
 config->end_bridge_callback(config->end_bridge_callback_data);
 }

 return res;
}

/*!
 * \brief bridge the call and set CDR
 *
 * \param chan The bridge considers this channel the caller.
 * \param peer The bridge considers this channel the callee.
 * \param config Configuration for this bridge.
 *
 * Set start time, check for two channels,check if monitor on
 * check for feature activation, create new CDR
 * \retval res on success.
 * \retval -1 on failure to bridge.
 */
int ast_bridge_call(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config)
{
 return ast_bridge_call_with_flags(chan, peer, config, 0);
}

enum play_tone_action {
 PLAYTONE_NONE = 0,
 PLAYTONE_CHANNEL1 = (1 << 0),
 PLAYTONE_CHANNEL2 = (1 << 1),
 PLAYTONE_BOTH = PLAYTONE_CHANNEL1 | PLAYTONE_CHANNEL2,
};

static enum play_tone_action parse_playtone(const char *playtone_val)
{
 if (ast_strlen_zero(playtone_val) || ast_false(playtone_val)) {
 return PLAYTONE_NONE;
 } if (!strcasecmp(playtone_val, "channel1")) {
 return PLAYTONE_CHANNEL1;
 } else if (!strcasecmp(playtone_val, "channel2") || ast_true(playtone_val)) {
 return PLAYTONE_CHANNEL2;
 } else if (!strcasecmp(playtone_val, "both")) {
 return PLAYTONE_BOTH;
 } else {
 /* Invalid input. Assume none */
 return PLAYTONE_NONE;
 }
}

/*!
 * \brief Bridge channels together
 * \param s
 * \param m
 *
 * Make sure valid channels were specified,
 * send errors if any of the channels could not be found/locked, answer channels if needed,
 * create the placeholder channels and grab the other channels
 * make the channels compatible, send error if we fail doing so
 * setup the bridge thread object and start the bridge.
 *
 * \retval 0
 */
static int action_bridge(struct mansession *s, const struct message *m)
{
 const char *channela = astman_get_header(m, "Channel1");
 const char *channelb = astman_get_header(m, "Channel2");
 enum play_tone_action playtone = parse_playtone(astman_get_header(m, "Tone"));
 RAII_VAR(struct ast_channel *, chana, NULL, ao2_cleanup);
 RAII_VAR(struct ast_channel *, chanb, NULL, ao2_cleanup);
 const char *chana_exten;
 const char *chana_context;
 int chana_priority;
 const char *chanb_exten;
 const char *chanb_context;
 int chanb_priority;
 struct ast_bridge *bridge;
 char buf[256];
 RAII_VAR(struct ast_features_xfer_config *, xfer_cfg_a, NULL, ao2_cleanup);
 RAII_VAR(struct ast_features_xfer_config *, xfer_cfg_b, NULL, ao2_cleanup);

 /* make sure valid channels were specified */
 if (ast_strlen_zero(channela) || ast_strlen_zero(channelb)) {
 astman_send_error(s, m, "Missing channel parameter in request");
 return 0;
 }

 ast_debug(1, "Performing Bridge action on %s and %s\n", channela, channelb);

 /* Start with chana */
 chana = ast_channel_get_by_name_prefix(channela, strlen(channela));
 if (!chana) {
 snprintf(buf, sizeof(buf), "Channel1 does not exist: %s", channela);
 astman_send_error(s, m, buf);
 return 0;
 }
 ast_channel_lock(chana);
 xfer_cfg_a = ast_get_chan_features_xfer_config(chana);
 chana_exten = ast_strdupa(ast_channel_exten(chana));
 chana_context = ast_strdupa(ast_channel_context(chana));
 chana_priority = ast_channel_priority(chana);
 if (ast_test_flag(ast_channel_flags(chana), AST_FLAG_IN_AUTOLOOP)) {
 chana_priority++;
 }
 ast_channel_unlock(chana);

 chanb = ast_channel_get_by_name_prefix(channelb, strlen(channelb));
 if (!chanb) {
 snprintf(buf, sizeof(buf), "Channel2 does not exist: %s", channelb);
 astman_send_error(s, m, buf);
 return 0;
 }
 ast_channel_lock(chanb);
 xfer_cfg_b = ast_get_chan_features_xfer_config(chanb);
 chanb_exten = ast_strdupa(ast_channel_exten(chanb));
 chanb_context = ast_strdupa(ast_channel_context(chanb));
 chanb_priority = ast_channel_priority(chanb);
 if (ast_test_flag(ast_channel_flags(chanb), AST_FLAG_IN_AUTOLOOP)) {
 chanb_priority++;
 }
 ast_channel_unlock(chanb);

 bridge = ast_bridge_basic_new();
 if (!bridge) {
 astman_send_error(s, m, "Unable to create bridge\n");
 return 0;
 }

 ast_bridge_set_after_goto(chana, chana_context, chana_exten, chana_priority);
 if (ast_bridge_add_channel(bridge, chana, NULL, playtone & PLAYTONE_CHANNEL1, xfer_cfg_a ? xfer_cfg_a->xfersound : NULL)) {
 snprintf(buf, sizeof(buf), "Unable to add Channel1 to bridge: %s", ast_channel_name(chana));
 astman_send_error(s, m, buf);
 ast_bridge_destroy(bridge, 0);
 return 0;
 }

 ast_bridge_set_after_goto(chanb, chanb_context, chanb_exten, chanb_priority);
 if (ast_bridge_add_channel(bridge, chanb, NULL, playtone & PLAYTONE_CHANNEL2, xfer_cfg_b ? xfer_cfg_b->xfersound : NULL)) {
 snprintf(buf, sizeof(buf), "Unable to add Channel2 to bridge: %s", ast_channel_name(chanb));
 astman_send_error(s, m, buf);
 ast_bridge_destroy(bridge, 0);
 return 0;
 }

 astman_send_ack(s, m, "Channels have been bridged");
 ao2_cleanup(bridge);

 return 0;
}

static char *app_bridge = "Bridge";

enum {
 BRIDGE_OPT_PLAYTONE = (1 << 0),
 OPT_CALLEE_HANGUP = (1 << 1),
 OPT_CALLER_HANGUP = (1 << 2),
 OPT_DURATION_LIMIT = (1 << 3),
 OPT_DURATION_STOP = (1 << 4),
 OPT_CALLEE_TRANSFER = (1 << 5),
 OPT_CALLER_TRANSFER = (1 << 6),
 OPT_CALLEE_MONITOR = (1 << 7),
 OPT_CALLER_MONITOR = (1 << 8),
 OPT_CALLEE_PARK = (1 << 9),
 OPT_CALLER_PARK = (1 << 10),
 OPT_CALLEE_KILL = (1 << 11),
 OPT_CALLEE_GO_ON = (1 << 12),
};

enum {
 OPT_ARG_DURATION_LIMIT = 0,
 OPT_ARG_DURATION_STOP,
 OPT_ARG_CALLEE_GO_ON,
 /* note: this entry _MUST_ be the last one in the enum */
 OPT_ARG_ARRAY_SIZE,
};

AST_APP_OPTIONS(bridge_exec_options, BEGIN_OPTIONS
 AST_APP_OPTION('p', BRIDGE_OPT_PLAYTONE),
 AST_APP_OPTION_ARG('F', OPT_CALLEE_GO_ON, OPT_ARG_CALLEE_GO_ON),
 AST_APP_OPTION('h', OPT_CALLEE_HANGUP),
 AST_APP_OPTION('H', OPT_CALLER_HANGUP),
 AST_APP_OPTION('k', OPT_CALLEE_PARK),
 AST_APP_OPTION('K', OPT_CALLER_PARK),
 AST_APP_OPTION_ARG('L', OPT_DURATION_LIMIT, OPT_ARG_DURATION_LIMIT),
 AST_APP_OPTION_ARG('S', OPT_DURATION_STOP, OPT_ARG_DURATION_STOP),
 AST_APP_OPTION('t', OPT_CALLEE_TRANSFER),
 AST_APP_OPTION('T', OPT_CALLER_TRANSFER),
 AST_APP_OPTION('w', OPT_CALLEE_MONITOR),
 AST_APP_OPTION('W', OPT_CALLER_MONITOR),
 AST_APP_OPTION('x', OPT_CALLEE_KILL),
END_OPTIONS );

int ast_bridge_timelimit(struct ast_channel *chan, struct ast_bridge_config *config,
 char *parse, struct timeval *calldurationlimit)
{
 char *stringp = ast_strdupa(parse);
 char *limit_str, *warning_str, *warnfreq_str;
 const char *var;
 int play_to_caller = 0, play_to_callee = 0;
 int delta;

 limit_str = strsep(&stringp, ":");
 warning_str = strsep(&stringp, ":");
 warnfreq_str = strsep(&stringp, ":");

 config->timelimit = atol(limit_str);
 if (warning_str)
 config->play_warning = atol(warning_str);
 if (warnfreq_str)
 config->warning_freq = atol(warnfreq_str);

 if (!config->timelimit) {
 ast_log(LOG_WARNING, "Bridge does not accept L(%s)\n", limit_str);
 config->timelimit = config->play_warning = config->warning_freq = 0;
 config->warning_sound = NULL;
 return -1; /* error */
 } else if ( (delta = config->play_warning - config->timelimit) > 0) {
 int w = config->warning_freq;

 /*
 * If the first warning is requested _after_ the entire call
 * would end, and no warning frequency is requested, then turn
 * off the warning. If a warning frequency is requested, reduce
 * the 'first warning' time by that frequency until it falls
 * within the call's total time limit.
 *
 * Graphically:
 * timelim->| delta |<-playwarning
 * 0__________________|_________________|
 * | w | | | |
 *
 * so the number of intervals to cut is 1+(delta-1)/w
 */
 if (w == 0) {
 config->play_warning = 0;
 } else {
 config->play_warning -= w * ( 1 + (delta-1)/w );
 if (config->play_warning < 1)
 config->play_warning = config->warning_freq = 0;
 }
 }

 ast_channel_lock(chan);

 var = pbx_builtin_getvar_helper(chan, "LIMIT_PLAYAUDIO_CALLER");
 play_to_caller = var ? ast_true(var) : 1;

 var = pbx_builtin_getvar_helper(chan, "LIMIT_PLAYAUDIO_CALLEE");
 play_to_callee = var ? ast_true(var) : 0;

 if (!play_to_caller && !play_to_callee)
 play_to_caller = 1;

 var = pbx_builtin_getvar_helper(chan, "LIMIT_WARNING_FILE");
 config->warning_sound = !ast_strlen_zero(var) ? ast_strdup(var) : ast_strdup("timeleft");

 /* The code looking at config wants a NULL, not just "", to decide
 * that the message should not be played, so we replace "" with NULL.
 * Note, pbx_builtin_getvar_helper _can_ return NULL if the variable is
 * not found.
 */

 var = pbx_builtin_getvar_helper(chan, "LIMIT_TIMEOUT_FILE");
 config->end_sound = !ast_strlen_zero(var) ? ast_strdup(var) : NULL;

 var = pbx_builtin_getvar_helper(chan, "LIMIT_CONNECT_FILE");
 config->start_sound = !ast_strlen_zero(var) ? ast_strdup(var) : NULL;

 ast_channel_unlock(chan);

 /* undo effect of S(x) in case they are both used */
 calldurationlimit->tv_sec = 0;
 calldurationlimit->tv_usec = 0;

 /* more efficient to do it like S(x) does since no advanced opts */
 if (!config->play_warning && !config->start_sound && !config->end_sound && config->timelimit) {
 calldurationlimit->tv_sec = config->timelimit / 1000;
 calldurationlimit->tv_usec = (config->timelimit % 1000) * 1000;
 ast_verb(3, "Setting call duration limit to %.3lf seconds.\n",
 calldurationlimit->tv_sec + calldurationlimit->tv_usec / 1000000.0);
 play_to_caller = 0;
 play_to_callee = 0;
 config->timelimit = 0;
 config->play_warning = 0;
 config->warning_freq = 0;
 } else {
 ast_verb(4, "Limit Data for this call:\n");
 ast_verb(4, "timelimit = %ld ms (%.3lf s)\n", config->timelimit, config->timelimit / 1000.0);
 ast_verb(4, "play_warning = %ld ms (%.3lf s)\n", config->play_warning, config->play_warning / 1000.0);
 ast_verb(4, "play_to_caller = %s\n", play_to_caller ? "yes" : "no");
 ast_verb(4, "play_to_callee = %s\n", play_to_callee ? "yes" : "no");
 ast_verb(4, "warning_freq = %ld ms (%.3lf s)\n", config->warning_freq, config->warning_freq / 1000.0);
 ast_verb(4, "start_sound = %s\n", S_OR(config->start_sound, ""));
 ast_verb(4, "warning_sound = %s\n", config->warning_sound);
 ast_verb(4, "end_sound = %s\n", S_OR(config->end_sound, ""));
 }
 if (play_to_caller)
 ast_set_flag(&(config->features_caller), AST_FEATURE_PLAY_WARNING);
 if (play_to_callee)
 ast_set_flag(&(config->features_callee), AST_FEATURE_PLAY_WARNING);
 return 0;
}


/*!
 * \brief Bridge channels
 * \param chan
 * \param data channel to bridge with.
 *
 * Split data, check we aren't bridging with ourself, check valid channel,
 * answer call if not already, check compatible channels, setup bridge config
 * now bridge call, if transferred party hangs up return to PBX extension.
 */
static int bridge_exec(struct ast_channel *chan, const char *data)
{
 struct ast_channel *current_dest_chan = NULL;
 char *tmp_data = NULL;
 struct ast_flags opts = { 0, };
 struct ast_bridge_config bconfig = { { 0, }, };
 char *opt_args[OPT_ARG_ARRAY_SIZE];
 struct timeval calldurationlimit = { 0, };
 const char *context;
 const char *extension;
 int priority;
 int bridge_add_failed;
 int res = -1;
 struct ast_bridge_features chan_features;
 struct ast_bridge_features *peer_features;
 struct ast_bridge *bridge;
 struct ast_features_xfer_config *xfer_cfg;

 AST_DECLARE_APP_ARGS(args,
 AST_APP_ARG(dest_chan);
 AST_APP_ARG(options);
 );

 tmp_data = ast_strdupa(data ?: "");
 AST_STANDARD_APP_ARGS(args, tmp_data);
 if (!ast_strlen_zero(args.options)) {
 ast_app_parse_options(bridge_exec_options, &opts, opt_args, args.options);
 }

 /* make sure we have a valid end point */
 if (!ast_strlen_zero(args.dest_chan)) {
 current_dest_chan = ast_channel_get_by_name_prefix(args.dest_chan,
 strlen(args.dest_chan));
 }
 if (!current_dest_chan) {
 ast_verb(4, "Bridge failed because channel '%s' does not exist\n",
 args.dest_chan ?: "");
 pbx_builtin_setvar_helper(chan, "BRIDGERESULT", "NONEXISTENT");
 return 0;
 }

 /* avoid bridge with ourselves */
 if (chan == current_dest_chan) {
 ast_channel_unref(current_dest_chan);
 ast_log(LOG_WARNING, "Unable to bridge channel %s with itself\n", ast_channel_name(chan));
 pbx_builtin_setvar_helper(chan, "BRIDGERESULT", "LOOP");
 return 0;
 }

 if (ast_test_flag(&opts, OPT_DURATION_LIMIT)
 && !ast_strlen_zero(opt_args[OPT_ARG_DURATION_LIMIT])
 && ast_bridge_timelimit(chan, &bconfig, opt_args[OPT_ARG_DURATION_LIMIT], &calldurationlimit)) {
 goto done;
 }

 if (ast_test_flag(&opts, OPT_CALLEE_TRANSFER))
 ast_set_flag(&(bconfig.features_callee), AST_FEATURE_REDIRECT);
 if (ast_test_flag(&opts, OPT_CALLER_TRANSFER))
 ast_set_flag(&(bconfig.features_caller), AST_FEATURE_REDIRECT);
 if (ast_test_flag(&opts, OPT_CALLEE_HANGUP))
 ast_set_flag(&(bconfig.features_callee), AST_FEATURE_DISCONNECT);
 if (ast_test_flag(&opts, OPT_CALLER_HANGUP))
 ast_set_flag(&(bconfig.features_caller), AST_FEATURE_DISCONNECT);
 if (ast_test_flag(&opts, OPT_CALLEE_MONITOR))
 ast_set_flag(&(bconfig.features_callee), AST_FEATURE_AUTOMON);
 if (ast_test_flag(&opts, OPT_CALLER_MONITOR))
 ast_set_flag(&(bconfig.features_caller), AST_FEATURE_AUTOMON);
 if (ast_test_flag(&opts, OPT_CALLEE_PARK))
 ast_set_flag(&(bconfig.features_callee), AST_FEATURE_PARKCALL);
 if (ast_test_flag(&opts, OPT_CALLER_PARK))
 ast_set_flag(&(bconfig.features_caller), AST_FEATURE_PARKCALL);

 /* Setup after bridge goto location. */
 if (ast_test_flag(&opts, OPT_CALLEE_GO_ON)) {
 ast_channel_lock(chan);
 context = ast_strdupa(ast_channel_context(chan));
 extension = ast_strdupa(ast_channel_exten(chan));
 priority = ast_channel_priority(chan);
 ast_channel_unlock(chan);
 ast_bridge_set_after_go_on(current_dest_chan, context, extension, priority,
 opt_args[OPT_ARG_CALLEE_GO_ON]);
 } else if (!ast_test_flag(&opts, OPT_CALLEE_KILL)) {
 ast_channel_lock(current_dest_chan);
 context = ast_strdupa(ast_channel_context(current_dest_chan));
 extension = ast_strdupa(ast_channel_exten(current_dest_chan));
 priority = ast_channel_priority(current_dest_chan);
 ast_channel_unlock(current_dest_chan);
 ast_bridge_set_after_go_on(current_dest_chan, context, extension, priority, NULL);
 }

 if (ast_bridge_features_init(&chan_features)) {
 ast_bridge_features_cleanup(&chan_features);
 goto done;
 }

 peer_features = ast_bridge_features_new();
 if (!peer_features) {
 ast_bridge_features_cleanup(&chan_features);
 goto done;
 }

 if (pre_bridge_setup(chan, current_dest_chan, &bconfig, &chan_features, peer_features)) {
 ast_bridge_features_destroy(peer_features);
 ast_bridge_features_cleanup(&chan_features);
 goto done;
 }

 bridge = ast_bridge_basic_new();
 if (!bridge) {
 ast_bridge_features_destroy(peer_features);
 ast_bridge_features_cleanup(&chan_features);
 goto done;
 }

 ast_channel_lock(current_dest_chan);
 xfer_cfg = ast_get_chan_features_xfer_config(current_dest_chan);
 ast_channel_unlock(current_dest_chan);
 bridge_add_failed = ast_bridge_add_channel(bridge, current_dest_chan, peer_features,
 ast_test_flag(&opts, BRIDGE_OPT_PLAYTONE),
 xfer_cfg ? xfer_cfg->xfersound : NULL);
 ao2_cleanup(xfer_cfg);
 if (bridge_add_failed) {
 ast_bridge_features_cleanup(&chan_features);
 ast_bridge_destroy(bridge, 0);
 goto done;
 }

 /* Don't keep the channel ref in case it was not already in a bridge. */
 current_dest_chan = ast_channel_unref(current_dest_chan);

 res = ast_bridge_join(bridge, chan, NULL, &chan_features, NULL,
 AST_BRIDGE_JOIN_PASS_REFERENCE);

 ast_bridge_features_cleanup(&chan_features);

done:
 if (res == -1) {
 pbx_builtin_setvar_helper(chan, "BRIDGERESULT", "FAILURE");
 } else {
 pbx_builtin_setvar_helper(chan, "BRIDGERESULT", "SUCCESS");
 }

 ast_free((char *) bconfig.warning_sound);
 ast_free((char *) bconfig.end_sound);
 ast_free((char *) bconfig.start_sound);

 ast_channel_cleanup(current_dest_chan);
 return 0;
}

static int unload_module(void)
{
 unload_features_config();

 ast_manager_unregister("Bridge");

 ast_unregister_application(app_bridge);

 return 0;
}

static int load_module(void)
{
 int res;

 res = load_features_config();
 res |= ast_register_application2(app_bridge, bridge_exec, NULL, NULL, NULL);
 res |= ast_manager_register_xml_core("Bridge", EVENT_FLAG_CALL, action_bridge);

 return res ? AST_MODULE_LOAD_FAILURE : AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_GLOBAL_SYMBOLS | AST_MODFLAG_LOAD_ORDER, "Call Features",
 .support_level = AST_MODULE_SUPPORT_CORE,
 .load = load_module,
 .unload = unload_module,
 .reload = reload_features_config,
 .load_pri = AST_MODPRI_CORE,
 .requires = "extconfig",
);