Fix inverted test preventing DTMF disconnect from working.

[asterisk/asterisk.git] / main / features.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2012, Digium, Inc.
 * Copyright (C) 2012, Russell Bryant
 *
 * 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 Routines implementing call features as call pickup, parking and transfer
 *
 * \author Mark Spencer <markster@digium.com>
 */

/*! \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"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/_private.h"

#include <pthread.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/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/adsi.h"
#include "asterisk/devicestate.h"
#include "asterisk/monitor.h"
#include "asterisk/audiohook.h"
#include "asterisk/global_datastores.h"
#include "asterisk/astobj2.h"
#include "asterisk/cel.h"
#include "asterisk/test.h"
#include "asterisk/bridging.h"
#include "asterisk/bridging_basic.h"

/*
 * Party A - transferee
 * Party B - transferer
 * Party C - target of transfer
 *
 * DTMF attended transfer works within the channel bridge.
 * Unfortunately, when either party A or B in the channel bridge
 * hangs up, that channel is not completely hung up until the
 * transfer completes.  This is a real problem depending upon
 * the channel technology involved.
 *
 * For chan_dahdi, the channel is crippled until the hangup is
 * complete.  Either the channel is not useable (analog) or the
 * protocol disconnect messages are held up (PRI/BRI/SS7) and
 * the media is not released.
 *
 * For chan_sip, a call limit of one is going to block that
 * endpoint from any further calls until the hangup is complete.
 *
 * For party A this is a minor problem.  The party A channel
 * will only be in this condition while party B is dialing and
 * when party B and C are conferring.  The conversation between
 * party B and C is expected to be a short one.  Party B is
 * either asking a question of party C or announcing party A.
 * Also party A does not have much incentive to hangup at this
 * point.
 *
 * For party B this can be a major problem during a blonde
 * transfer.  (A blonde transfer is our term for an attended
 * transfer that is converted into a blind transfer. :))  Party
 * B could be the operator.  When party B hangs up, he assumes
 * that he is out of the original call entirely.  The party B
 * channel will be in this condition while party C is ringing,
 * while attempting to recall party B, and while waiting between
 * call attempts.
 *
 * WARNING:
 * The ATXFER_NULL_TECH conditional is a hack to fix the
 * problem.  It will replace the party B channel technology with
 * a NULL channel driver.  The consequences of this code is that
 * the 'h' extension will not be able to access any channel
 * technology specific information like SIP statistics for the
 * call.
 *
 * Uncomment the ATXFER_NULL_TECH define below to replace the
 * party B channel technology in the channel bridge to complete
 * hanging up the channel technology.
 */
//#define ATXFER_NULL_TECH      1

/*** 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 specified <replaceable>channel</replaceable>.</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" />
                                        <value name="INCOMPATIBLE" />
                                </variable>
                        </variablelist>
                </description>
        </application>
        <manager name="Park" language="en_US">
                <synopsis>
                        Park a channel.
                </synopsis>
                <syntax>
                        <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
                        <parameter name="Channel" required="true">
                                <para>Channel name to park.</para>
                        </parameter>
                        <parameter name="Channel2" required="true">
                                <para>Channel to return to if timeout.</para>
                        </parameter>
                        <parameter name="Timeout">
                                <para>Number of milliseconds to wait before callback.</para>
                        </parameter>
                        <parameter name="Parkinglot">
                                <para>Specify in which parking lot to park the channel.</para>
                        </parameter>
                </syntax>
                <description>
                        <para>Park a channel.</para>
                </description>
        </manager>
        <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="yes" />
                                        <enum name="no" />
                                </enumlist>
                        </parameter>
                </syntax>
                <description>
                        <para>Bridge together two channels already in the PBX.</para>
                </description>
        </manager>
        <function name="FEATURE" language="en_US">
                <synopsis>
                        Get or set a feature option on a channel.
                </synopsis>
                <syntax>
                        <parameter name="option_name" required="true">
                                <para>The allowed values are:</para>
                                <enumlist>
                                        <enum name="parkingtime"><para>Specified in seconds.</para></enum>
                                        <enum name="inherit"><para>Inherit feature settings made in FEATURE or FEATUREMAP to child channels.</para></enum>
                                </enumlist>
                        </parameter>
                </syntax>
                <description>
                        <para>When this function is used as a read, it will get the current
                        value of the specified feature option for this channel.  It will be
                        the value of this option configured in features.conf if a channel specific
                        value has not been set.  This function can also be used to set a channel
                        specific value for the supported feature options.</para>
                </description>
                <see-also>
                        <ref type="function">FEATUREMAP</ref>
                </see-also>
        </function>
        <function name="FEATUREMAP" language="en_US">
                <synopsis>
                        Get or set a feature map to a given value on a specific channel.
                </synopsis>
                <syntax>
                        <parameter name="feature_name" required="true">
                                <para>The allowed values are:</para>
                                <enumlist>
                                        <enum name="atxfer"><para>Attended Transfer</para></enum>
                                        <enum name="blindxfer"><para>Blind Transfer</para></enum>
                                        <enum name="automon"><para>Auto Monitor</para></enum>
                                        <enum name="disconnect"><para>Call Disconnect</para></enum>
                                        <enum name="parkcall"><para>Park Call</para></enum>
                                        <enum name="automixmon"><para>Auto MixMonitor</para></enum>
                                </enumlist>
                        </parameter>
                </syntax>
                <description>
                        <para>When this function is used as a read, it will get the current
                        digit sequence mapped to the specified feature for this channel.  This
                        value will be the one configured in features.conf if a channel specific
                        value has not been set.  This function can also be used to set a channel
                        specific value for a feature mapping.</para>
                </description>
                <see-also>
                        <ref type="function">FEATURE</ref>
                </see-also>
        </function>
        <managerEvent language="en_US" name="ParkedCallTimeOut">
                <managerEventInstance class="EVENT_FLAG_CALL">
                        <synopsis>Raised when a parked call times out.</synopsis>
                        <syntax>
                                <parameter name="Exten">
                                        <para>The parking lot extension.</para>
                                </parameter>
                                <parameter name="Channel"/>
                                <parameter name="Parkinglot">
                                        <para>The name of the parking lot.</para>
                                </parameter>
                                <parameter name="CallerIDNum"/>
                                <parameter name="CallerIDName"/>
                                <parameter name="ConnectedLineNum"/>
                                <parameter name="ConnectedLineName"/>
                                <parameter name="UniqueID"/>
                        </syntax>
                        <see-also>
                                <ref type="managerEvent">ParkedCall</ref>
                        </see-also>
                </managerEventInstance>
        </managerEvent>
        <managerEvent language="en_US" name="ParkedCallGiveUp">
                <managerEventInstance class="EVENT_FLAG_CALL">
                        <synopsis>Raised when a parked call hangs up while in the parking lot.</synopsis>
                        <syntax>
                                <xi:include xpointer="xpointer(/docs/managerEvent[@name='ParkedCallTimeOut']/managerEventInstance/syntax/parameter[@name='Exten'])" />
                                <parameter name="Channel"/>
                                <xi:include xpointer="xpointer(/docs/managerEvent[@name='ParkedCallTimeOut']/managerEventInstance/syntax/parameter[@name='Parkinglot'])" />
                                <parameter name="CallerIDNum"/>
                                <parameter name="CallerIDName"/>
                                <parameter name="ConnectedLineNum"/>
                                <parameter name="ConnectedLineName"/>
                                <parameter name="UniqueID"/>
                        </syntax>
                        <see-also>
                                <ref type="managerEvent">ParkedCall</ref>
                        </see-also>
                </managerEventInstance>
        </managerEvent>
 ***/

#define DEFAULT_PARK_TIME                                                       45000   /*!< ms */
#define DEFAULT_PARK_EXTENSION                                          "700"
#define DEFAULT_TRANSFER_DIGIT_TIMEOUT                          3000    /*!< ms */
#define DEFAULT_FEATURE_DIGIT_TIMEOUT                           1000    /*!< ms */
#define DEFAULT_NOANSWER_TIMEOUT_ATTENDED_TRANSFER      15000   /*!< ms */
#define DEFAULT_ATXFER_DROP_CALL                                        0               /*!< Do not drop call. */
#define DEFAULT_ATXFER_LOOP_DELAY                                       10000   /*!< ms */
#define DEFAULT_ATXFER_CALLBACK_RETRIES                         2
#define DEFAULT_COMEBACK_CONTEXT                                        "parkedcallstimeout"
#define DEFAULT_COMEBACK_TO_ORIGIN                                      1
#define DEFAULT_COMEBACK_DIAL_TIME                                      30

#define AST_MAX_WATCHERS 256
#define MAX_DIAL_FEATURE_OPTIONS 30

/* TODO Scrape all of the parking stuff out of features.c */

struct feature_group_exten {
        AST_LIST_ENTRY(feature_group_exten) entry;
        AST_DECLARE_STRING_FIELDS(
                AST_STRING_FIELD(exten);
        );
        struct ast_call_feature *feature;
};

struct feature_group {
        AST_LIST_ENTRY(feature_group) entry;
        AST_DECLARE_STRING_FIELDS(
                AST_STRING_FIELD(gname);
        );
        AST_LIST_HEAD_NOLOCK(, feature_group_exten) features;
};

static AST_RWLIST_HEAD_STATIC(feature_groups, feature_group);

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;

static const char *parkedcall = "ParkedCall";

static char pickup_ext[AST_MAX_EXTENSION];                 /*!< Call pickup extension */

/*! Parking lot access ramp dialplan usage entry. */
struct parking_dp_ramp {
        /*! Next node in the parking lot spaces dialplan list. */
        AST_LIST_ENTRY(parking_dp_ramp) node;
        /*! TRUE if the parking lot access extension is exclusive. */
        unsigned int exclusive:1;
        /*! Parking lot access extension */
        char exten[1];
};

/*! Parking lot dialplan access ramp map */
AST_LIST_HEAD_NOLOCK(parking_dp_ramp_map, parking_dp_ramp);

/*! Parking lot spaces dialplan usage entry. */
struct parking_dp_spaces {
        /*! Next node in the parking lot spaces dialplan list. */
        AST_LIST_ENTRY(parking_dp_spaces) node;
        /*! First parking space */
        int start;
        /*! Last parking space */
        int stop;
};

/*! Parking lot dialplan context space map */
AST_LIST_HEAD_NOLOCK(parking_dp_space_map, parking_dp_spaces);

/*! Parking lot context dialplan usage entry. */
struct parking_dp_context {
        /*! Next node in the parking lot contexts dialplan list. */
        AST_LIST_ENTRY(parking_dp_context) node;
        /*! Parking access extensions defined in this context. */
        struct parking_dp_ramp_map access_extens;
        /*! Parking spaces defined in this context. */
        struct parking_dp_space_map spaces;
        /*! Parking hints defined in this context. */
        struct parking_dp_space_map hints;
        /*! Parking lot context name */
        char context[1];
};

/*! Parking lot dialplan usage map. */
AST_LIST_HEAD_NOLOCK(parking_dp_map, parking_dp_context);

/*!
 * \brief Description of one parked call, added to a list while active, then removed.
 * The list belongs to a parkinglot.
 */
struct parkeduser {
        struct ast_channel *chan;                   /*!< Parked channel */
        struct timeval start;                       /*!< Time the park started */
        int parkingnum;                             /*!< Parking lot space used */
        char parkingexten[AST_MAX_EXTENSION];       /*!< If set beforehand, parking extension used for this call */
        char context[AST_MAX_CONTEXT];              /*!< Where to go if our parking time expires */
        char exten[AST_MAX_EXTENSION];
        int priority;
        unsigned int parkingtime;                   /*!< Maximum length in parking lot before return */
        /*! Method to entertain the caller when parked: AST_CONTROL_RINGING, AST_CONTROL_HOLD, or 0(none) */
        enum ast_control_frame_type hold_method;
        unsigned int notquiteyet:1;
        unsigned int options_specified:1;
        char peername[AST_CHANNEL_NAME];
        unsigned char moh_trys;
        /*! Parking lot this entry belongs to.  Holds a parking lot reference. */
        struct ast_parkinglot *parkinglot;
        AST_LIST_ENTRY(parkeduser) list;
};

/*! Parking lot configuration options. */
struct parkinglot_cfg {
        /*! Music class used for parking */
        char mohclass[MAX_MUSICCLASS];
        /*! Extension to park calls in this parking lot. */
        char parkext[AST_MAX_EXTENSION];
        /*! Context for which parking is made accessible */
        char parking_con[AST_MAX_CONTEXT];
        /*! Context that timed-out parked calls are called back on when comebacktoorigin=no */
        char comebackcontext[AST_MAX_CONTEXT];
        /*! First available extension for parking */
        int parking_start;
        /*! Last available extension for parking */
        int parking_stop;
        /*! Default parking time in ms. */
        unsigned int parkingtime;
        /*!
         * \brief Enable DTMF based transfers on bridge when picking up parked calls.
         *
         * \details
         * none(0)
         * AST_FEATURE_FLAG_BYCALLEE
         * AST_FEATURE_FLAG_BYCALLER
         * AST_FEATURE_FLAG_BYBOTH
         */
        int parkedcalltransfers;
        /*!
         * \brief Enable DTMF based parking on bridge when picking up parked calls.
         *
         * \details
         * none(0)
         * AST_FEATURE_FLAG_BYCALLEE
         * AST_FEATURE_FLAG_BYCALLER
         * AST_FEATURE_FLAG_BYBOTH
         */
        int parkedcallreparking;
        /*!
         * \brief Enable DTMF based hangup on a bridge when pickup up parked calls.
         *
         * \details
         * none(0)
         * AST_FEATURE_FLAG_BYCALLEE
         * AST_FEATURE_FLAG_BYCALLER
         * AST_FEATURE_FLAG_BYBOTH
         */
        int parkedcallhangup;
        /*!
         * \brief Enable DTMF based recording on a bridge when picking up parked calls.
         *
         * \details
         * none(0)
         * AST_FEATURE_FLAG_BYCALLEE
         * AST_FEATURE_FLAG_BYCALLER
         * AST_FEATURE_FLAG_BYBOTH
         */
        int parkedcallrecording;

        /*! Time in seconds to dial the device that parked a timedout parked call */
        unsigned int comebackdialtime;
        /*! TRUE if findslot is set to next */
        unsigned int parkfindnext:1;
        /*! TRUE if the parking lot is exclusively accessed by parkext */
        unsigned int parkext_exclusive:1;
        /*! Add parking hints automatically */
        unsigned int parkaddhints:1;
        /*! TRUE if configuration is invalid and the parking lot should not be used. */
        unsigned int is_invalid:1;
        /*! TRUE if a timed out parked call goes back to the parker */
        unsigned int comebacktoorigin:1;
};

/*! \brief Structure for parking lots which are put in a container. */
struct ast_parkinglot {
        /*! Name of the parking lot. */
        char name[AST_MAX_CONTEXT];
        /*! Parking lot user configuration. */
        struct parkinglot_cfg cfg;

        /*! Parking space to start next park search. */
        int next_parking_space;

        /*! That which bears the_mark shall be deleted if parking lot empty! (Used during reloads.) */
        unsigned int the_mark:1;
        /*! TRUE if the parking lot is disabled. */
        unsigned int disabled:1;

        /*! List of active parkings in this parkinglot */
        AST_LIST_HEAD(parkinglot_parklist, parkeduser) parkings;
};

/*! \brief The configured parking lots container. Always at least one  - the default parking lot */
static struct ao2_container *parkinglots;

/*!
 * \brief Default parking lot.
 * \note Holds a parkinglot reference.
 * \note Will not be NULL while running.
 */
static struct ast_parkinglot *default_parkinglot;

/*! Force a config reload to reload regardless of config file timestamp. */
static int force_reload_load;

static int parkedplay = 0;                                 /*!< Who to play courtesytone to when someone picks up a parked call. */
static int parkeddynamic = 0;                              /*!< Enable creation of parkinglots dynamically */
static char courtesytone[256];                             /*!< Courtesy tone used to pickup parked calls and on-touch-record */
static char xfersound[256];                                /*!< Call transfer sound */
static char xferfailsound[256];                            /*!< Call transfer failure sound */
static char pickupsound[256];                              /*!< Pickup sound */
static char pickupfailsound[256];                          /*!< Pickup failure sound */

/*!
 * \brief Context for parking dialback to parker.
 * \note The need for the context is a KLUDGE.
 *
 * \todo Might be able to eliminate the parking_con_dial context
 * kludge by running app_dial directly in its own thread to
 * simulate a PBX.
 */
static char parking_con_dial[] = "park-dial";

/*! Ensure that features.conf reloads on one thread at a time. */
AST_MUTEX_DEFINE_STATIC(features_reload_lock);

static int adsipark;

static int transferdigittimeout;
static int featuredigittimeout;

static int atxfernoanswertimeout;
static unsigned int atxferdropcall;
static unsigned int atxferloopdelay;
static unsigned int atxfercallbackretries;

static char *registrar = "features";               /*!< Registrar for operations */

/*! PARK_APP_NAME application arguments */
AST_DEFINE_APP_ARGS_TYPE(park_app_args,
        AST_APP_ARG(timeout);           /*!< Time in ms to remain in the parking lot. */
        AST_APP_ARG(return_con);        /*!< Context to return parked call if timeout. */
        AST_APP_ARG(return_ext);        /*!< Exten to return parked call if timeout. */
        AST_APP_ARG(return_pri);        /*!< Priority to return parked call if timeout. */
        AST_APP_ARG(options);           /*!< Parking option flags. */
        AST_APP_ARG(pl_name);           /*!< Parking lot name to use if present. */
        AST_APP_ARG(dummy);                     /*!< Place to put any remaining args string. */
        );

/* module and CLI command definitions */
static const char *parkcall = "Park";

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

#if defined(ATXFER_NULL_TECH)
/*!
 * \internal
 * \brief Set the channel technology to the kill technology.
 *
 * \param chan Channel to change technology.
 *
 * \return Nothing
 */
static void set_kill_chan_tech(struct ast_channel *chan)
{
        int idx;

        ast_channel_lock(chan);

        /* Hangup the channel's physical side */
        if (ast_channel_tech(chan)->hangup) {
                ast_channel_tech(chan)->hangup(chan);
        }
        if (ast_channel_tech_pvt(chan)) {
                ast_log(LOG_WARNING, "Channel '%s' may not have been hung up properly\n",
                        ast_channel_name(chan));
                ast_free(ast_channel_tech_pvt(chan));
                ast_channel_tech_pvt_set(chan, NULL);
        }

        /* Install the kill technology and wake up anyone waiting on it. */
        ast_channel_tech_set(chan, &ast_kill_tech);
        for (idx = 0; idx < AST_MAX_FDS; ++idx) {
                switch (idx) {
                case AST_ALERT_FD:
                case AST_TIMING_FD:
                case AST_GENERATOR_FD:
                        /* Don't clear these fd's. */
                        break;
                default:
                        ast_channel_set_fd(chan, idx, -1);
                        break;
                }
        }
        ast_queue_frame(chan, &ast_null_frame);

        ast_channel_unlock(chan);
}
#endif  /* defined(ATXFER_NULL_TECH) */

#if defined(ATXFER_NULL_TECH)
/*!
 * \internal
 * \brief Set the channel name to something unique.
 *
 * \param chan Channel to change name.
 *
 * \return Nothing
 */
static void set_new_chan_name(struct ast_channel *chan)
{
        static int seq_num_last;
        int seq_num;
        int len;
        char *chan_name;
        char dummy[1];

        /* Create the new channel name string. */
        ast_channel_lock(chan);
        seq_num = ast_atomic_fetchadd_int(&seq_num_last, +1);
        len = snprintf(dummy, sizeof(dummy), "%s<XFER_%x>", ast_channel_name(chan), seq_num) + 1;
        chan_name = ast_alloca(len);
        snprintf(chan_name, len, "%s<XFER_%x>", ast_channel_name(chan), seq_num);
        ast_channel_unlock(chan);

        ast_change_name(chan, chan_name);
}
#endif  /* defined(ATXFER_NULL_TECH) */

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;
}

/* Forward declarations */
static struct ast_parkinglot *parkinglot_addref(struct ast_parkinglot *parkinglot);
static void parkinglot_unref(struct ast_parkinglot *parkinglot);
static struct ast_parkinglot *find_parkinglot(const char *name);
static struct ast_parkinglot *create_parkinglot(const char *name);
static struct ast_parkinglot *copy_parkinglot(const char *name, const struct ast_parkinglot *parkinglot);
static int parkinglot_activate(struct ast_parkinglot *parkinglot);
static int play_message_on_chan(struct ast_channel *play_to, struct ast_channel *other, const char *msg, const char *audiofile);

/*!
 * \internal
 * \brief Get the parking extension if it exists.
 *
 * \param exten_str Parking extension to see if exists.
 * \param chan Channel to autoservice while looking for exten.  (Could be NULL)
 * \param context Parking context to look in for exten.
 *
 * \retval exten on success.
 * \retval NULL on error or exten does not exist.
 */
static struct ast_exten *get_parking_exten(const char *exten_str, struct ast_channel *chan, const char *context)
{
        struct ast_exten *exten;
        struct pbx_find_info q = { .stacklen = 0 }; /* the rest is reset in pbx_find_extension */
        const char *app_at_exten;

        ast_debug(4, "Checking if %s@%s is a parking exten\n", exten_str, context);
        exten = pbx_find_extension(chan, NULL, &q, context, exten_str, 1, NULL, NULL,
                E_MATCH);
        if (!exten) {
                return NULL;
        }

        app_at_exten = ast_get_extension_app(exten);
        if (!app_at_exten || strcasecmp(parkcall, app_at_exten)) {
                return NULL;
        }

        return exten;
}

int ast_parking_ext_valid(const char *exten_str, struct ast_channel *chan, const char *context)
{
        return get_parking_exten(exten_str, chan, context) ? 1 : 0;
}

const char *ast_pickup_ext(void)
{
        return pickup_ext;
}

struct ast_bridge_thread_obj
{
        struct ast_bridge_config bconfig;
        struct ast_channel *chan;
        struct ast_channel *peer;
        struct ast_callid *callid;                             /*<! callid pointer (Only used to bind thread) */
        unsigned int return_to_pbx:1;
};

static int parkinglot_hash_cb(const void *obj, const int flags)
{
        const struct ast_parkinglot *parkinglot = obj;

        return ast_str_case_hash(parkinglot->name);
}

static int parkinglot_cmp_cb(void *obj, void *arg, int flags)
{
        struct ast_parkinglot *parkinglot = obj;
        struct ast_parkinglot *parkinglot2 = arg;

        return !strcasecmp(parkinglot->name, parkinglot2->name) ? CMP_MATCH | CMP_STOP : 0;
}

/*!
 * \brief store context, extension and priority
 * \param chan, context, ext, pri
 */
static void set_c_e_p(struct ast_channel *chan, const char *context, const char *ext, int pri)
{
        ast_channel_context_set(chan, context);
        ast_channel_exten_set(chan, ext);
        ast_channel_priority_set(chan, pri);
}

/*!
 * \brief Check goto on transfer
 * \param chan
 *
 * Check if channel has 'GOTO_ON_BLINDXFR' set, if not exit.
 * When found make sure the types are compatible. Check if channel is valid
 * if so start the new channel else hangup the call.
 */
static void check_goto_on_transfer(struct ast_channel *chan)
{
        struct ast_channel *xferchan;
        const char *val;
        char *goto_on_transfer;
        char *x;

        ast_channel_lock(chan);
        val = pbx_builtin_getvar_helper(chan, "GOTO_ON_BLINDXFR");
        if (ast_strlen_zero(val)) {
                ast_channel_unlock(chan);
                return;
        }
        goto_on_transfer = ast_strdupa(val);
        ast_channel_unlock(chan);

        ast_debug(1, "Attempting GOTO_ON_BLINDXFR=%s for %s.\n", val, ast_channel_name(chan));

        xferchan = ast_channel_alloc(0, AST_STATE_DOWN, 0, 0, "", "", "", ast_channel_linkedid(chan), 0,
                "%s", ast_channel_name(chan));
        if (!xferchan) {
                return;
        }

        /* Make formats okay */
        ast_format_copy(ast_channel_readformat(xferchan), ast_channel_readformat(chan));
        ast_format_copy(ast_channel_writeformat(xferchan), ast_channel_writeformat(chan));

        if (ast_channel_masquerade(xferchan, chan)) {
                /* Failed to setup masquerade. */
                ast_hangup(xferchan);
                return;
        }

        for (x = goto_on_transfer; *x; ++x) {
                if (*x == '^') {
                        *x = ',';
                }
        }
        ast_parseable_goto(xferchan, goto_on_transfer);
        ast_channel_state_set(xferchan, AST_STATE_UP);
        ast_clear_flag(ast_channel_flags(xferchan), AST_FLAGS_ALL);
        ast_channel_clear_softhangup(xferchan, AST_SOFTHANGUP_ALL);

        ast_do_masquerade(xferchan);
        if (ast_pbx_start(xferchan)) {
                /* Failed to start PBX. */
                ast_hangup(xferchan);
        }
}

static struct ast_channel *feature_request_and_dial(struct ast_channel *caller,
        const char *caller_name, struct ast_channel *requestor,
        struct ast_channel *transferee, const char *type, struct ast_format_cap *cap, const char *addr,
        int timeout, int *outstate, const char *language);

static const struct ast_datastore_info channel_app_data_datastore = {
        .type = "Channel appdata datastore",
        .destroy = ast_free_ptr,
};

static int set_chan_app_data(struct ast_channel *chan, const char *src_app_data)
{
        struct ast_datastore *datastore;
        char *dst_app_data;

        datastore = ast_datastore_alloc(&channel_app_data_datastore, NULL);
        if (!datastore) {
                return -1;
        }

        dst_app_data = ast_malloc(strlen(src_app_data) + 1);
        if (!dst_app_data) {
                ast_datastore_free(datastore);
                return -1;
        }

        ast_channel_data_set(chan, strcpy(dst_app_data, src_app_data));
        datastore->data = dst_app_data;
        ast_channel_datastore_add(chan, datastore);
        return 0;
}

/*!
 * \brief bridge the call
 * \param data thread bridge.
 *
 * Set Last Data for respective channels, reset cdr for channels
 * bridge call, check if we're going back to dialplan
 * if not hangup both legs of the call
 */
static void *bridge_call_thread(void *data)
{
        struct ast_bridge_thread_obj *tobj = data;

        if (tobj->callid) {
                ast_callid_threadassoc_add(tobj->callid);
                /* Need to deref and set to null since ast_bridge_thread_obj has no common destructor */
                tobj->callid = ast_callid_unref(tobj->callid);
        }

        ast_channel_appl_set(tobj->chan, !tobj->return_to_pbx ? "Transferred Call" : "ManagerBridge");
        if (set_chan_app_data(tobj->chan, ast_channel_name(tobj->peer))) {
                ast_channel_data_set(tobj->chan, "(Empty)");
        }
        ast_channel_appl_set(tobj->peer, !tobj->return_to_pbx ? "Transferred Call" : "ManagerBridge");
        if (set_chan_app_data(tobj->peer, ast_channel_name(tobj->chan))) {
                ast_channel_data_set(tobj->peer, "(Empty)");
        }

        if (tobj->return_to_pbx) {
                ast_after_bridge_set_goto(tobj->chan, ast_channel_context(tobj->chan),
                        ast_channel_exten(tobj->chan), ast_channel_priority(tobj->chan));
                ast_after_bridge_set_goto(tobj->peer, ast_channel_context(tobj->peer),
                        ast_channel_exten(tobj->peer), ast_channel_priority(tobj->peer));
        }

        ast_bridge_call(tobj->chan, tobj->peer, &tobj->bconfig);

        ast_after_bridge_goto_run(tobj->chan);

        ast_free(tobj);

        return NULL;
}

/*!
 * \brief create thread for the bridging call
 * \param tobj
 */
static void bridge_call_thread_launch(struct ast_bridge_thread_obj *tobj)
{
        pthread_t thread;

        /* This needs to be unreffed once it has been associated with the new thread. */
        tobj->callid = ast_read_threadstorage_callid();

        if (ast_pthread_create_detached(&thread, NULL, bridge_call_thread, tobj)) {
                ast_log(LOG_ERROR, "Failed to create bridge_call_thread.\n");
                ast_callid_unref(tobj->callid);
                ast_hangup(tobj->chan);
                ast_hangup(tobj->peer);
                ast_free(tobj);
        }
}

/*!
 * \brief Announce call parking by ADSI
 * \param chan .
 * \param parkingexten .
 * Create message to show for ADSI, display message.
 * \retval 0 on success.
 * \retval -1 on failure.
 */
static int adsi_announce_park(struct ast_channel *chan, char *parkingexten)
{
        int res;
        int justify[5] = {ADSI_JUST_CENT, ADSI_JUST_CENT, ADSI_JUST_CENT, ADSI_JUST_CENT};
        char tmp[256];
        char *message[5] = {NULL, NULL, NULL, NULL, NULL};

        snprintf(tmp, sizeof(tmp), "Parked on %s", parkingexten);
        message[0] = tmp;
        res = ast_adsi_load_session(chan, NULL, 0, 1);
        if (res == -1)
                return res;
        return ast_adsi_print(chan, message, justify, 1);
}

/*!
 * \brief Find parking lot name from channel
 * \note Channel needs to be locked while the returned string is in use.
 */
static const char *findparkinglotname(struct ast_channel *chan)
{
        const char *name;

        /* The channel variable overrides everything */
        name = pbx_builtin_getvar_helper(chan, "PARKINGLOT");
        if (!name && !ast_strlen_zero(ast_channel_parkinglot(chan))) {
                /* Use the channel's parking lot. */
                name = ast_channel_parkinglot(chan);
        }
        return name;
}

/*! \brief Notify metermaids that we've changed an extension */
static void notify_metermaids(const char *exten, char *context, enum ast_device_state state)
{
        ast_debug(4, "Notification of state change to metermaids %s@%s\n to state '%s'",
                exten, context, ast_devstate2str(state));

        ast_devstate_changed(state, AST_DEVSTATE_CACHABLE, "park:%s@%s", exten, context);
}

/*! \brief metermaids callback from devicestate.c */
static enum ast_device_state metermaidstate(const char *data)
{
        char *context;
        char *exten;

        context = ast_strdupa(data);

        exten = strsep(&context, "@");
        if (!context)
                return AST_DEVICE_INVALID;

        ast_debug(4, "Checking state of exten %s in context %s\n", exten, context);

        if (!ast_exists_extension(NULL, context, exten, 1, NULL))
                return AST_DEVICE_NOT_INUSE;

        return AST_DEVICE_INUSE;
}

/*! Options to pass to park_call_full */
enum ast_park_call_options {
        /*! Provide ringing to the parked caller instead of music on hold */
        AST_PARK_OPT_RINGING =   (1 << 0),
        /*! Randomly choose a parking spot for the caller instead of choosing
         *  the first one that is available. */
        AST_PARK_OPT_RANDOMIZE = (1 << 1),
        /*! Do not announce the parking number */
        AST_PARK_OPT_SILENCE = (1 << 2),
};

/*! Optional additional parking options when parking a call. */
struct ast_park_call_args {
        /*! How long to wait in the parking lot before the call gets sent back
         *  to the specified return extension (or a best guess at where it came
         *  from if not explicitly specified). */
        int timeout;
        /*! An output parameter to store the parking space where the parked caller
         *  was placed. */
        int *extout;
        const char *orig_chan_name;
        const char *return_con;
        const char *return_ext;
        int return_pri;
        uint32_t flags;
        /*! Parked user that has already obtained a parking space */
        struct parkeduser *pu;
        /*! \brief Parkinglot to be parked in */
        struct ast_parkinglot *parkinglot;
};

/*!
 * \internal
 * \brief Create a dynamic parking lot.
 *
 * \param name Dynamic parking lot name to create.
 * \param chan Channel to get dynamic parking lot parameters.
 *
 * \retval parkinglot on success.
 * \retval NULL on error.
 */
static struct ast_parkinglot *create_dynamic_parkinglot(const char *name, struct ast_channel *chan)
{
        const char *dyn_context;
        const char *dyn_exten;
        const char *dyn_range;
        const char *template_name;
        struct ast_parkinglot *template_parkinglot = NULL;
        struct ast_parkinglot *parkinglot;
        int dyn_start;
        int dyn_end;

        ast_channel_lock(chan);
        template_name = ast_strdupa(S_OR(pbx_builtin_getvar_helper(chan, "PARKINGDYNAMIC"), ""));
        dyn_context = ast_strdupa(S_OR(pbx_builtin_getvar_helper(chan, "PARKINGDYNCONTEXT"), ""));
        dyn_exten = ast_strdupa(S_OR(pbx_builtin_getvar_helper(chan, "PARKINGDYNEXTEN"), ""));
        dyn_range = ast_strdupa(S_OR(pbx_builtin_getvar_helper(chan, "PARKINGDYNPOS"), ""));
        ast_channel_unlock(chan);

        if (!ast_strlen_zero(template_name)) {
                template_parkinglot = find_parkinglot(template_name);
                if (!template_parkinglot) {
                        ast_debug(1, "PARKINGDYNAMIC lot %s does not exist.\n",
                                template_name);
                } else if (template_parkinglot->cfg.is_invalid) {
                        ast_debug(1, "PARKINGDYNAMIC lot %s has invalid config.\n",
                                template_name);
                        parkinglot_unref(template_parkinglot);
                        template_parkinglot = NULL;
                }
        }
        if (!template_parkinglot) {
                template_parkinglot = parkinglot_addref(default_parkinglot);
                ast_debug(1, "Using default parking lot for template\n");
        }

        parkinglot = copy_parkinglot(name, template_parkinglot);
        if (!parkinglot) {
                ast_log(LOG_ERROR, "Could not build dynamic parking lot!\n");
        } else {
                /* Configure the dynamic parking lot. */
                if (!ast_strlen_zero(dyn_context)) {
                        ast_copy_string(parkinglot->cfg.parking_con, dyn_context,
                                sizeof(parkinglot->cfg.parking_con));
                }
                if (!ast_strlen_zero(dyn_exten)) {
                        ast_copy_string(parkinglot->cfg.parkext, dyn_exten,
                                sizeof(parkinglot->cfg.parkext));
                }
                if (!ast_strlen_zero(dyn_range)) {
                        if (sscanf(dyn_range, "%30d-%30d", &dyn_start, &dyn_end) != 2) {
                                ast_log(LOG_WARNING,
                                        "Format for parking positions is a-b, where a and b are numbers\n");
                        } else if (dyn_end < dyn_start || dyn_start <= 0 || dyn_end <= 0) {
                                ast_log(LOG_WARNING,
                                        "Format for parking positions is a-b, where a <= b\n");
                        } else {
                                parkinglot->cfg.parking_start = dyn_start;
                                parkinglot->cfg.parking_stop = dyn_end;
                        }
                }

                /*
                 * Sanity check for dynamic parking lot configuration.
                 *
                 * XXX It may be desirable to instead check if the dynamic
                 * parking lot overlaps any existing lots like what is done for
                 * a reload.
                 */
                if (!strcmp(parkinglot->cfg.parking_con, template_parkinglot->cfg.parking_con)) {
                        if (!strcmp(parkinglot->cfg.parkext, template_parkinglot->cfg.parkext)
                                && parkinglot->cfg.parkext_exclusive) {
                                ast_log(LOG_WARNING,
                                        "Parking lot '%s' conflicts with template parking lot '%s'!\n"
                                        "Change either PARKINGDYNCONTEXT or PARKINGDYNEXTEN.\n",
                                        parkinglot->name, template_parkinglot->name);
                        }
                        if ((template_parkinglot->cfg.parking_start <= parkinglot->cfg.parking_start
                                        && parkinglot->cfg.parking_start <= template_parkinglot->cfg.parking_stop)
                                || (template_parkinglot->cfg.parking_start <= parkinglot->cfg.parking_stop
                                        && parkinglot->cfg.parking_stop <= template_parkinglot->cfg.parking_stop)
                                || (parkinglot->cfg.parking_start < template_parkinglot->cfg.parking_start
                                        && template_parkinglot->cfg.parking_stop < parkinglot->cfg.parking_stop)) {
                                ast_log(LOG_WARNING,
                                        "Parking lot '%s' parking spaces overlap template parking lot '%s'!\n"
                                        "Change PARKINGDYNPOS.\n",
                                        parkinglot->name, template_parkinglot->name);
                        }
                }

                parkinglot_activate(parkinglot);
                ao2_link(parkinglots, parkinglot);
        }
        parkinglot_unref(template_parkinglot);

        return parkinglot;
}

/*!
 * \internal
 * \brief Abort parking a call that has not completed parking yet.
 *
 * \param pu Parked user item to clean up.
 *
 * \note The parking lot parkings list is locked on entry.
 *
 * \return Nothing
 */
static void park_space_abort(struct parkeduser *pu)
{
        struct ast_parkinglot *parkinglot;

        parkinglot = pu->parkinglot;

        /* Put back the parking space just allocated. */
        --parkinglot->next_parking_space;

        AST_LIST_REMOVE(&parkinglot->parkings, pu, list);

        AST_LIST_UNLOCK(&parkinglot->parkings);
        parkinglot_unref(parkinglot);
        ast_free(pu);
}

/*!
 * \internal
 * \brief Reserve a parking space in a parking lot for a call being parked.
 *
 * \param park_me Channel being parked.
 * \param parker Channel parking the call.
 * \param args Optional additional parking options when parking a call.
 *
 * \return Parked call descriptor or NULL if failed.
 * \note The parking lot list is locked if successful.
 */
static struct parkeduser *park_space_reserve(struct ast_channel *park_me, struct ast_channel *parker, struct ast_park_call_args *args)
{
        struct parkeduser *pu;
        int i;
        int parking_space = -1;
        const char *parkinglotname;
        const char *parkingexten;
        struct parkeduser *cur;
        struct ast_parkinglot *parkinglot = NULL;

        if (args->parkinglot) {
                parkinglot = parkinglot_addref(args->parkinglot);
                parkinglotname = parkinglot->name;
        } else {
                if (parker) {
                        parkinglotname = findparkinglotname(parker);
                } else { /* parker was NULL, check park_me (ParkAndAnnounce / res_agi) */
                        parkinglotname = findparkinglotname(park_me);
                }
                if (!ast_strlen_zero(parkinglotname)) {
                        parkinglot = find_parkinglot(parkinglotname);
                } else {
                        /* Parking lot is not specified, so use the default parking lot. */
                        ast_debug(4, "This could be an indication channel driver needs updating, using default lot.\n");
                        parkinglot = parkinglot_addref(default_parkinglot);
                }
        }

        /* Dynamically create parkinglot */
        if (!parkinglot && parkeddynamic && !ast_strlen_zero(parkinglotname)) {
                parkinglot = create_dynamic_parkinglot(parkinglotname, park_me);
        }

        if (!parkinglot) {
                ast_log(LOG_WARNING, "Parking lot not available to park %s.\n", ast_channel_name(park_me));
                return NULL;
        }

        ast_debug(1, "Parking lot: %s\n", parkinglot->name);
        if (parkinglot->disabled || parkinglot->cfg.is_invalid) {
                ast_log(LOG_WARNING, "Parking lot %s is not in a useable state.\n",
                        parkinglot->name);
                parkinglot_unref(parkinglot);
                return NULL;
        }

        /* Allocate memory for parking data */
        if (!(pu = ast_calloc(1, sizeof(*pu)))) {
                parkinglot_unref(parkinglot);
                return NULL;
        }

        /* Lock parking list */
        AST_LIST_LOCK(&parkinglot->parkings);

        /* Check for channel variable PARKINGEXTEN */
        parkingexten = ast_strdupa(S_OR(pbx_builtin_getvar_helper(park_me, "PARKINGEXTEN"), ""));
        if (!ast_strlen_zero(parkingexten)) {
                /*!
                 * \note The API forces us to specify a numeric parking slot, even
                 * though the architecture would tend to support non-numeric extensions
                 * (as are possible with SIP, for example).  Hence, we enforce that
                 * limitation here.  If extout was not numeric, we could permit
                 * arbitrary non-numeric extensions.
                 */
                if (sscanf(parkingexten, "%30d", &parking_space) != 1 || parking_space <= 0) {
                        ast_log(LOG_WARNING, "PARKINGEXTEN='%s' is not a valid parking space.\n",
                                parkingexten);
                        AST_LIST_UNLOCK(&parkinglot->parkings);
                        parkinglot_unref(parkinglot);
                        ast_free(pu);
                        return NULL;
                }

                if (parking_space < parkinglot->cfg.parking_start
                        || parkinglot->cfg.parking_stop < parking_space) {
                        /*
                         * Cannot allow park because parking lots are not setup for
                         * spaces outside of the lot.  (Things like dialplan hints don't
                         * exist for outside lot space.)
                         */
                        ast_log(LOG_WARNING, "PARKINGEXTEN=%d is not in %s (%d-%d).\n",
                                parking_space, parkinglot->name, parkinglot->cfg.parking_start,
                                parkinglot->cfg.parking_stop);
                        AST_LIST_UNLOCK(&parkinglot->parkings);
                        parkinglot_unref(parkinglot);
                        ast_free(pu);
                        return NULL;
                }

                /* Check if requested parking space is in use. */
                AST_LIST_TRAVERSE(&parkinglot->parkings, cur, list) {
                        if (cur->parkingnum == parking_space) {
                                ast_log(LOG_WARNING, "PARKINGEXTEN=%d is already in use in %s\n",
                                        parking_space, parkinglot->name);
                                AST_LIST_UNLOCK(&parkinglot->parkings);
                                parkinglot_unref(parkinglot);
                                ast_free(pu);
                                return NULL;
                        }
                }
        } else {
                /* PARKINGEXTEN is empty, so find a usable extension in the lot to park the call */
                int start; /* The first slot we look in the parkinglot. It can be randomized. */
                int start_checked = 0; /* flag raised once the first slot is checked */

                /* If using randomize mode, set start to random position on parking range */
                if (ast_test_flag(args, AST_PARK_OPT_RANDOMIZE)) {
                        start = ast_random() % (parkinglot->cfg.parking_stop - parkinglot->cfg.parking_start + 1);
                        start += parkinglot->cfg.parking_start;
                } else if (parkinglot->cfg.parkfindnext
                        && parkinglot->cfg.parking_start <= parkinglot->next_parking_space
                        && parkinglot->next_parking_space <= parkinglot->cfg.parking_stop) {
                        /* Start looking with the next parking space in the lot. */
                        start = parkinglot->next_parking_space;
                } else {
                        /* Otherwise, just set it to the start position. */
                        start = parkinglot->cfg.parking_start;
                }

                /* free parking extension linear search: O(n^2) */
                for (i = start; ; i++) {
                        /* If we are past the end, wrap around to the first parking slot*/
                        if (i == parkinglot->cfg.parking_stop + 1) {
                                i = parkinglot->cfg.parking_start;
                        }

                        if (i == start) {
                                /* At this point, if start_checked, we've exhausted all the possible slots. */
                                if (start_checked) {
                                        break;
                                } else {
                                        start_checked = 1;
                                }
                        }

                        /* Search the list of parked calls already in use for i. If we find it, it's in use. */
                        AST_LIST_TRAVERSE(&parkinglot->parkings, cur, list) {
                                if (cur->parkingnum == i) {
                                        break;
                                }
                        }
                        if (!cur) {
                                /* We found a parking space. */
                                parking_space = i;
                                break;
                        }
                }
                if (parking_space == -1) {
                        /* We did not find a parking space.  Lot is full. */
                        ast_log(LOG_WARNING, "No more parking spaces in %s\n", parkinglot->name);
                        AST_LIST_UNLOCK(&parkinglot->parkings);
                        parkinglot_unref(parkinglot);
                        ast_free(pu);
                        return NULL;
                }
        }

        /* Prepare for next parking space search. */
        parkinglot->next_parking_space = parking_space + 1;

        snprintf(pu->parkingexten, sizeof(pu->parkingexten), "%d", parking_space);
        pu->notquiteyet = 1;
        pu->parkingnum = parking_space;
        pu->parkinglot = parkinglot;
        AST_LIST_INSERT_TAIL(&parkinglot->parkings, pu, list);

        return pu;
}

static unsigned int get_parkingtime(struct ast_channel *chan, struct ast_parkinglot *parkinglot);

/* Park a call */
static int park_call_full(struct ast_channel *chan, struct ast_channel *peer, struct ast_park_call_args *args)
{
        struct parkeduser *pu = args->pu;
        const char *event_from;         /*!< Channel name that is parking the call. */
        char app_data[AST_MAX_EXTENSION + AST_MAX_CONTEXT];

        if (pu == NULL) {
                args->pu = pu = park_space_reserve(chan, peer, args);
                if (pu == NULL) {
                        return -1;
                }
        }

        ast_channel_appl_set(chan, "Parked Call");
        ast_channel_data_set(chan, NULL);

        pu->chan = chan;

        /* Put the parked channel on hold if we have two different channels */
        if (chan != peer) {
                if (ast_test_flag(args, AST_PARK_OPT_RINGING)) {
                        pu->hold_method = AST_CONTROL_RINGING;
                        ast_indicate(chan, AST_CONTROL_RINGING);
                } else {
                        pu->hold_method = AST_CONTROL_HOLD;
                        ast_indicate_data(chan, AST_CONTROL_HOLD,
                                S_OR(pu->parkinglot->cfg.mohclass, NULL),
                                !ast_strlen_zero(pu->parkinglot->cfg.mohclass) ? strlen(pu->parkinglot->cfg.mohclass) + 1 : 0);
                }
        }

        pu->start = ast_tvnow();
        pu->parkingtime = (args->timeout > 0) ? args->timeout : get_parkingtime(chan, pu->parkinglot);
        if (args->extout)
                *(args->extout) = pu->parkingnum;

        if (peer) {
                event_from = S_OR(args->orig_chan_name, ast_channel_name(peer));

                /*
                 * This is so ugly that it hurts, but implementing
                 * get_base_channel() on local channels could have ugly side
                 * effects.  We could have
                 * transferer<->local;1<->local;2<->parking and we need the
                 * callback name to be that of transferer.  Since local;1/2 have
                 * the same name we can be tricky and just grab the bridged
                 * channel from the other side of the local.
                 */
                if (!strcasecmp(ast_channel_tech(peer)->type, "Local")) {
                        struct ast_channel *tmpchan, *base_peer;
                        char other_side[AST_CHANNEL_NAME];
                        char *c;

                        ast_copy_string(other_side, event_from, sizeof(other_side));
                        if ((c = strrchr(other_side, ';'))) {
                                *++c = '1';
                        }
                        if ((tmpchan = ast_channel_get_by_name(other_side))) {
                                ast_channel_lock(tmpchan);
                                if ((base_peer = ast_bridged_channel(tmpchan))) {
                                        ast_copy_string(pu->peername, ast_channel_name(base_peer), sizeof(pu->peername));
                                }
                                ast_channel_unlock(tmpchan);
                                tmpchan = ast_channel_unref(tmpchan);
                        }
                } else {
                        ast_copy_string(pu->peername, event_from, sizeof(pu->peername));
                }
        } else {
                event_from = S_OR(pbx_builtin_getvar_helper(chan, "BLINDTRANSFER"),
                        ast_channel_name(chan));
        }

        /*
         * Remember what had been dialed, so that if the parking
         * expires, we try to come back to the same place
         */
        pu->options_specified = (!ast_strlen_zero(args->return_con) || !ast_strlen_zero(args->return_ext) || args->return_pri);

        /*
         * If extension has options specified, they override all other
         * possibilities such as the returntoorigin flag and transferred
         * context.  Information on extension options is lost here, so
         * we set a flag
         */
        ast_copy_string(pu->context,
                S_OR(args->return_con, S_OR(ast_channel_macrocontext(chan), ast_channel_context(chan))),
                sizeof(pu->context));
        ast_copy_string(pu->exten,
                S_OR(args->return_ext, S_OR(ast_channel_macroexten(chan), ast_channel_exten(chan))),
                sizeof(pu->exten));
        pu->priority = args->return_pri ? args->return_pri :
                (ast_channel_macropriority(chan) ? ast_channel_macropriority(chan) : ast_channel_priority(chan));

        /*
         * If parking a channel directly, don't quite yet get parking
         * running on it.  All parking lot entries are put into the
         * parking lot with notquiteyet on.
         */
        if (peer != chan) {
                pu->notquiteyet = 0;
        }

        /* Wake up the (presumably select()ing) thread */
        pthread_kill(parking_thread, SIGURG);
        ast_verb(2, "Parked %s on %d (lot %s). Will timeout back to extension [%s] %s, %d in %u seconds\n",
                ast_channel_name(chan), pu->parkingnum, pu->parkinglot->name,
                pu->context, pu->exten, pu->priority, (pu->parkingtime / 1000));

        ast_cel_report_event(chan, AST_CEL_PARK_START, NULL, pu->parkinglot->name, peer);
        /*** DOCUMENTATION
                <managerEventInstance>
                        <synopsis>Raised when a call has been parked.</synopsis>
                        <syntax>
                                <parameter name="Exten">
                                        <para>The parking lot extension.</para>
                                </parameter>
                                <parameter name="Parkinglot">
                                        <para>The name of the parking lot.</para>
                                </parameter>
                                <parameter name="From">
                                        <para>The name of the channel that parked the call.</para>
                                </parameter>
                        </syntax>
                        <see-also>
                                <ref type="application">Park</ref>
                                <ref type="manager">Park</ref>
                                <ref type="managerEvent">ParkedCallTimeOut</ref>
                                <ref type="managerEvent">ParkedCallGiveUp</ref>
                        </see-also>
                </managerEventInstance>
        ***/
        ast_manager_event(chan, EVENT_FLAG_CALL, "ParkedCall",
                "Exten: %s\r\n"
                "Channel: %s\r\n"
                "Parkinglot: %s\r\n"
                "From: %s\r\n"
                "Timeout: %ld\r\n"
                "CallerIDNum: %s\r\n"
                "CallerIDName: %s\r\n"
                "ConnectedLineNum: %s\r\n"
                "ConnectedLineName: %s\r\n"
                "Uniqueid: %s\r\n",
                pu->parkingexten, ast_channel_name(chan), pu->parkinglot->name, event_from,
                (long)pu->start.tv_sec + (long)(pu->parkingtime/1000) - (long)time(NULL),
                S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, "<unknown>"),
                S_COR(ast_channel_caller(chan)->id.name.valid, ast_channel_caller(chan)->id.name.str, "<unknown>"),
                S_COR(ast_channel_connected(chan)->id.number.valid, ast_channel_connected(chan)->id.number.str, "<unknown>"),
                S_COR(ast_channel_connected(chan)->id.name.valid, ast_channel_connected(chan)->id.name.str, "<unknown>"),
                ast_channel_uniqueid(chan)
                );
        ast_debug(4, "peer: %s\n", peer ? ast_channel_name(peer) : "-No peer-");
        ast_debug(4, "args->orig_chan_name: %s\n", args->orig_chan_name ? args->orig_chan_name : "-none-");
        ast_debug(4, "pu->peername: %s\n", pu->peername);
        ast_debug(4, "AMI ParkedCall Channel: %s\n", ast_channel_name(chan));
        ast_debug(4, "AMI ParkedCall From: %s\n", event_from);

        if (peer && adsipark && ast_adsi_available(peer)) {
                adsi_announce_park(peer, pu->parkingexten);     /* Only supports parking numbers */
                ast_adsi_unload_session(peer);
        }

        snprintf(app_data, sizeof(app_data), "%s,%s", pu->parkingexten,
                pu->parkinglot->name);
        if (ast_add_extension(pu->parkinglot->cfg.parking_con, 1, pu->parkingexten, 1,
                NULL, NULL, parkedcall, ast_strdup(app_data), ast_free_ptr, registrar)) {
                ast_log(LOG_ERROR, "Could not create parked call exten: %s@%s\n",
                        pu->parkingexten, pu->parkinglot->cfg.parking_con);
        } else {
                notify_metermaids(pu->parkingexten, pu->parkinglot->cfg.parking_con, AST_DEVICE_INUSE);
        }

        AST_LIST_UNLOCK(&pu->parkinglot->parkings);

        /* Only say number if it's a number and the channel hasn't been masqueraded away */
        if (peer && !ast_test_flag(args, AST_PARK_OPT_SILENCE)
                && (ast_strlen_zero(args->orig_chan_name) || !strcasecmp(ast_channel_name(peer), args->orig_chan_name))) {
                /*
                 * If a channel is masqueraded into peer while playing back the
                 * parking space number do not continue playing it back.  This
                 * is the case if an attended transfer occurs.
                 */
                ast_set_flag(ast_channel_flags(peer), AST_FLAG_MASQ_NOSTREAM);
                /* Tell the peer channel the number of the parking space */
                ast_say_digits(peer, pu->parkingnum, "", ast_channel_language(peer));
                ast_clear_flag(ast_channel_flags(peer), AST_FLAG_MASQ_NOSTREAM);
        }
        if (peer == chan) { /* pu->notquiteyet = 1 */
                /* Wake up parking thread if we're really done */
                if (ast_test_flag(args, AST_PARK_OPT_RINGING)) {
                        pu->hold_method = AST_CONTROL_RINGING;
                        ast_indicate(chan, AST_CONTROL_RINGING);
                } else {
                        pu->hold_method = AST_CONTROL_HOLD;
                        ast_indicate_data(chan, AST_CONTROL_HOLD,
                                S_OR(pu->parkinglot->cfg.mohclass, NULL),
                                !ast_strlen_zero(pu->parkinglot->cfg.mohclass) ? strlen(pu->parkinglot->cfg.mohclass) + 1 : 0);
                }
                pu->notquiteyet = 0;
                pthread_kill(parking_thread, SIGURG);
        }
        return 0;
}

int ast_park_call_exten(struct ast_channel *park_me, struct ast_channel *parker, const char *park_exten, const char *park_context, int timeout, int *extout)
{
        int res;
        char *parse;
        const char *app_data;
        struct ast_exten *exten;
        struct park_app_args app_args;
        struct ast_park_call_args args = {
                .timeout = timeout,
                .extout = extout,
        };

        if (!park_exten || !park_context) {
                return park_call_full(park_me, parker, &args);
        }

        /*
         * Determiine if the specified park extension has an exclusive
         * parking lot to use.
         */
        if (parker && parker != park_me) {
                ast_autoservice_start(park_me);
        }
        exten = get_parking_exten(park_exten, parker, park_context);
        if (exten) {
                app_data = ast_get_extension_app_data(exten);
                if (!app_data) {
                        app_data = "";
                }
                parse = ast_strdupa(app_data);
                AST_STANDARD_APP_ARGS(app_args, parse);

                if (!ast_strlen_zero(app_args.pl_name)) {
                        /* Find the specified exclusive parking lot */
                        args.parkinglot = find_parkinglot(app_args.pl_name);
                        if (!args.parkinglot && parkeddynamic) {
                                args.parkinglot = create_dynamic_parkinglot(app_args.pl_name, park_me);
                        }
                }
        }
        if (parker && parker != park_me) {
                ast_autoservice_stop(park_me);
        }

        res = park_call_full(park_me, parker, &args);
        if (args.parkinglot) {
                parkinglot_unref(args.parkinglot);
        }
        return res;
}

int ast_park_call(struct ast_channel *park_me, struct ast_channel *parker, int timeout, const char *park_exten, int *extout)
{
        struct ast_park_call_args args = {
                .timeout = timeout,
                .extout = extout,
        };

        return park_call_full(park_me, parker, &args);
}

/*!
 * \brief Park call via masqueraded channel and announce parking spot on peer channel.
 *
 * \param rchan the real channel to be parked
 * \param peer the channel to have the parking read to.
 * \param args Additional parking options when parking a call.
 *
 * \retval 0 on success.
 * \retval -1 on failure.
 */
static int masq_park_call(struct ast_channel *rchan, struct ast_channel *peer, struct ast_park_call_args *args)
{
        struct ast_channel *chan;

        /* Make a new, channel that we'll use to masquerade in the real one */
        chan = ast_channel_alloc(0, AST_STATE_DOWN, 0, 0, ast_channel_accountcode(rchan), ast_channel_exten(rchan),
                ast_channel_context(rchan), ast_channel_linkedid(rchan), ast_channel_amaflags(rchan), "Parked/%s", ast_channel_name(rchan));
        if (!chan) {
                ast_log(LOG_WARNING, "Unable to create parked channel\n");
                if (!ast_test_flag(args, AST_PARK_OPT_SILENCE)) {
                        if (peer == rchan) {
                                /* Only have one channel to worry about. */
                                ast_stream_and_wait(peer, "pbx-parkingfailed", "");
                        } else if (peer) {
                                /* Have two different channels to worry about. */
                                play_message_on_chan(peer, rchan, "failure message", "pbx-parkingfailed");
                        }
                }
                return -1;
        }

        args->pu = park_space_reserve(rchan, peer, args);
        if (!args->pu) {
                ast_hangup(chan);
                if (!ast_test_flag(args, AST_PARK_OPT_SILENCE)) {
                        if (peer == rchan) {
                                /* Only have one channel to worry about. */
                                ast_stream_and_wait(peer, "pbx-parkingfailed", "");
                        } else if (peer) {
                                /* Have two different channels to worry about. */
                                play_message_on_chan(peer, rchan, "failure message", "pbx-parkingfailed");
                        }
                }
                return -1;
        }

        /* Make formats okay */
        ast_format_copy(ast_channel_readformat(chan), ast_channel_readformat(rchan));
        ast_format_copy(ast_channel_writeformat(chan), ast_channel_writeformat(rchan));

        if (ast_channel_masquerade(chan, rchan)) {
                park_space_abort(args->pu);
                args->pu = NULL;
                ast_hangup(chan);
                if (!ast_test_flag(args, AST_PARK_OPT_SILENCE)) {
                        if (peer == rchan) {
                                /* Only have one channel to worry about. */
                                ast_stream_and_wait(peer, "pbx-parkingfailed", "");
                        } else if (peer) {
                                /* Have two different channels to worry about. */
                                play_message_on_chan(peer, rchan, "failure message", "pbx-parkingfailed");
                        }
                }
                return -1;
        }

        /* Setup the extensions and such */
        set_c_e_p(chan, ast_channel_context(rchan), ast_channel_exten(rchan), ast_channel_priority(rchan));

        /* Setup the macro extension and such */
        ast_channel_macrocontext_set(chan, ast_channel_macrocontext(rchan));
        ast_channel_macroexten_set(chan, ast_channel_macroexten(rchan));
        ast_channel_macropriority_set(chan, ast_channel_macropriority(rchan));

        /* Manually do the masquerade to make sure it is complete. */
        ast_do_masquerade(chan);

        if (peer == rchan) {
                peer = chan;
        }

        /* parking space reserved, return code check unnecessary */
        park_call_full(chan, peer, args);

        return 0;
}

int ast_masq_park_call_exten(struct ast_channel *park_me, struct ast_channel *parker, const char *park_exten, const char *park_context, int timeout, int *extout)
{
        int res;
        char *parse;
        const char *app_data;
        struct ast_exten *exten;
        struct park_app_args app_args;
        struct ast_park_call_args args = {
                .timeout = timeout,
                .extout = extout,
        };

        if (parker) {
                args.orig_chan_name = ast_strdupa(ast_channel_name(parker));
        }
        if (!park_exten || !park_context) {
                return masq_park_call(park_me, parker, &args);
        }

        /*
         * Determiine if the specified park extension has an exclusive
         * parking lot to use.
         */
        if (parker && parker != park_me) {
                ast_autoservice_start(park_me);
        }
        exten = get_parking_exten(park_exten, parker, park_context);
        if (exten) {
                app_data = ast_get_extension_app_data(exten);
                if (!app_data) {
                        app_data = "";
                }
                parse = ast_strdupa(app_data);
                AST_STANDARD_APP_ARGS(app_args, parse);

                if (!ast_strlen_zero(app_args.pl_name)) {
                        /* Find the specified exclusive parking lot */
                        args.parkinglot = find_parkinglot(app_args.pl_name);
                        if (!args.parkinglot && parkeddynamic) {
                                args.parkinglot = create_dynamic_parkinglot(app_args.pl_name, park_me);
                        }
                }
        }
        if (parker && parker != park_me) {
                ast_autoservice_stop(park_me);
        }

        res = masq_park_call(park_me, parker, &args);
        if (args.parkinglot) {
                parkinglot_unref(args.parkinglot);
        }
        return res;
}

int ast_masq_park_call(struct ast_channel *rchan, struct ast_channel *peer, int timeout, int *extout)
{
        struct ast_park_call_args args = {
                .timeout = timeout,
                .extout = extout,
        };

        if (peer) {
                args.orig_chan_name = ast_strdupa(ast_channel_name(peer));
        }
        return masq_park_call(rchan, peer, &args);
}

static int finishup(struct ast_channel *chan)
{
        ast_indicate(chan, AST_CONTROL_UNHOLD);

        return ast_autoservice_stop(chan);
}

/*!
 * \internal
 * \brief Builtin transfer park call helper.
 *
 * \param park_me Channel to be parked.
 * \param parker Channel parking the call.
 * \param park_exten Parking lot dialplan access ramp extension.
 *
 * \note Assumes park_me is on hold and in autoservice.
 *
 * \retval -1 on successful park.
 * \retval -1 on park_me hangup.
 * \retval AST_FEATURE_RETURN_SUCCESS on error to keep the bridge connected.
 */
static int xfer_park_call_helper(struct ast_channel *park_me, struct ast_channel *parker, struct ast_exten *park_exten)
{
        char *parse;
        const char *app_data;
        const char *pl_name;
        struct ast_park_call_args args = { 0, };
        struct park_app_args app_args;
        int res;

        app_data = ast_get_extension_app_data(park_exten);
        if (!app_data) {
                app_data = "";
        }
        parse = ast_strdupa(app_data);
        AST_STANDARD_APP_ARGS(app_args, parse);

        /* Find the parking lot */
        if (!ast_strlen_zero(app_args.pl_name)) {
                pl_name = app_args.pl_name;
        } else {
                pl_name = findparkinglotname(parker);
        }
        if (ast_strlen_zero(pl_name)) {
                /* Parking lot is not specified, so use the default parking lot. */
                args.parkinglot = parkinglot_addref(default_parkinglot);
        } else {
                args.parkinglot = find_parkinglot(pl_name);
                if (!args.parkinglot && parkeddynamic) {
                        args.parkinglot = create_dynamic_parkinglot(pl_name, park_me);
                }
        }

        if (args.parkinglot) {
                /* Park the call */
                res = finishup(park_me);
                if (res) {
                        /* park_me hungup on us. */
                        parkinglot_unref(args.parkinglot);
                        return -1;
                }
                res = masq_park_call(park_me, parker, &args);
                parkinglot_unref(args.parkinglot);
        } else {
                /* Parking failed because parking lot does not exist. */
                if (!ast_test_flag(&args, AST_PARK_OPT_SILENCE)) {
                        ast_stream_and_wait(parker, "pbx-parkingfailed", "");
                }
                finishup(park_me);
                res = -1;
        }

        return res ? AST_FEATURE_RETURN_SUCCESS : -1;
}

/*!
 * \brief set caller and callee according to the direction
 * \param caller, callee, peer, chan, sense
 *
 * Detect who triggered feature and set callee/caller variables accordingly
 */
static void set_peers(struct ast_channel **caller, struct ast_channel **callee,
        struct ast_channel *peer, struct ast_channel *chan, int sense)
{
        if (sense == FEATURE_SENSE_PEER) {
                *caller = peer;
                *callee = chan;
        } else {
                *callee = peer;
                *caller = chan;
        }
}

/*!
 * \brief support routing for one touch call parking
 * \param chan channel parking call
 * \param peer channel to be parked
 * \param config unsed
 * \param code unused
 * \param sense feature options
 * \param data unused
 *
 * \retval -1 on successful park.
 * \retval -1 on chan hangup.
 * \retval AST_FEATURE_RETURN_SUCCESS on error to keep the bridge connected.
 */
static int builtin_parkcall(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config, const char *code, int sense, void *data)
{
        struct ast_channel *parker;
        struct ast_channel *parkee;
        struct ast_park_call_args args = { 0, };

        /*
         * We used to set chan's exten and priority to "s" and 1 here,
         * but this generates (in some cases) an invalid extension, and
         * if "s" exists, could errantly cause execution of extensions
         * you don't expect.  It makes more sense to let nature take its
         * course when chan finishes, and let the pbx do its thing and
         * hang up when the park is over.
         */

        /* Answer if call is not up */
        if (ast_channel_state(chan) != AST_STATE_UP) {
                /*
                 * XXX Why are we doing this?  Both of the channels should be up
                 * since you cannot do DTMF features unless you are bridged.
                 */
                if (ast_answer(chan)) {
                        return -1;
                }

                /* Sleep to allow VoIP streams to settle down */
                if (ast_safe_sleep(chan, 1000)) {
                        return -1;
                }
        }

        /* one direction used to call park_call.... */
        set_peers(&parker, &parkee, peer, chan, sense);
        return masq_park_call(parkee, parker, &args) ? AST_FEATURE_RETURN_SUCCESS : -1;
}

/*!
 * \internal
 * \brief Play file to specified channel.
 *
 * \param play_to Channel to play audiofile to.
 * \param other Channel to put in autoservice while playing file.
 * \param msg Descriptive name of message type being played.
 * \param audiofile Audio file to play.
 *
 * \retval 0 on success.
 * \retval -1 on error. (Couldn't play file, a channel hung up,...)
 */
static int play_message_on_chan(struct ast_channel *play_to, struct ast_channel *other, const char *msg, const char *audiofile)
{
        /* Put other channel in autoservice. */
        if (ast_autoservice_start(other)) {
                return -1;
        }
        ast_autoservice_ignore(other, AST_FRAME_DTMF_BEGIN);
        ast_autoservice_ignore(other, AST_FRAME_DTMF_END);
        if (ast_stream_and_wait(play_to, audiofile, "")) {
                ast_log(LOG_WARNING, "Failed to play %s '%s'!\n", msg, audiofile);
                ast_autoservice_stop(other);
                return -1;
        }
        if (ast_autoservice_stop(other)) {
                return -1;
        }
        return 0;
}

/*!
 * \internal
 * \brief Play file to specified channels.
 *
 * \param left Channel on left to play file.
 * \param right Channel on right to play file.
 * \param which Play file on indicated channels: which < 0 play left, which == 0 play both, which > 0 play right
 * \param msg Descriptive name of message type being played.
 * \param audiofile Audio file to play to channels.
 *
 * \note Plays file to the indicated channels in turn so please
 * don't use this for very long messages.
 *
 * \retval 0 on success.
 * \retval -1 on error. (Couldn't play file, channel hung up,...)
 */
static int play_message_to_chans(struct ast_channel *left, struct ast_channel *right, int which, const char *msg, const char *audiofile)
{
        /* First play the file to the left channel if requested. */
        if (which <= 0 && play_message_on_chan(left, right, msg, audiofile)) {
                return -1;
        }

        /* Then play the file to the right channel if requested. */
        if (which >= 0 && play_message_on_chan(right, left, msg, audiofile)) {
                return -1;
        }

        return 0;
}

/*!
 * \brief Play message to both caller and callee in bridged call, plays synchronously, autoservicing the
 * other channel during the message, so please don't use this for very long messages
 */
static int play_message_in_bridged_call(struct ast_channel *caller_chan, struct ast_channel *callee_chan, const char *audiofile)
{
        return play_message_to_chans(caller_chan, callee_chan, 0, "automon message",
                audiofile);
}

/*!
 * \brief Monitor a channel by DTMF
 * \param chan channel requesting monitor
 * \param peer channel to be monitored
 * \param config
 * \param code
 * \param sense feature options
 *
 * \param data
 * Check monitor app enabled, setup channels, both caller/callee chans not null
 * get TOUCH_MONITOR variable for filename if exists, exec monitor app.
 * \retval AST_FEATURE_RETURN_SUCCESS on success.
 * \retval -1 on error.
 */
static int builtin_automonitor(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config, const char *code, int sense, void *data)
{
        char *caller_chan_id = NULL, *callee_chan_id = NULL, *args = NULL, *touch_filename = NULL;
        int x = 0;
        size_t len;
        struct ast_channel *caller_chan, *callee_chan;
        const char *automon_message_start = NULL;
        const char *automon_message_stop = NULL;
        const char *touch_format = NULL;
        const char *touch_monitor = NULL;
        const char *touch_monitor_prefix = NULL;
        struct ast_app *monitor_app;

        monitor_app = pbx_findapp("Monitor");
        if (!monitor_app) {
                ast_log(LOG_ERROR,"Cannot record the call. The monitor application is disabled.\n");
                return -1;
        }

        set_peers(&caller_chan, &callee_chan, peer, chan, sense);

        /* Find extra messages */
        automon_message_start = pbx_builtin_getvar_helper(caller_chan, "TOUCH_MONITOR_MESSAGE_START");
        automon_message_stop = pbx_builtin_getvar_helper(caller_chan, "TOUCH_MONITOR_MESSAGE_STOP");

        if (!ast_strlen_zero(courtesytone)) {   /* Play courtesy tone if configured */
                if(play_message_in_bridged_call(caller_chan, callee_chan, courtesytone) == -1) {
                        return -1;
                }
        }

        if (ast_channel_monitor(callee_chan)) {
                ast_verb(4, "User hit '%s' to stop recording call.\n", code);
                if (!ast_strlen_zero(automon_message_stop)) {
                        play_message_in_bridged_call(caller_chan, callee_chan, automon_message_stop);
                }
                ast_channel_monitor(callee_chan)->stop(callee_chan, 1);
                return AST_FEATURE_RETURN_SUCCESS;
        }

        touch_format = pbx_builtin_getvar_helper(caller_chan, "TOUCH_MONITOR_FORMAT");
        touch_monitor = pbx_builtin_getvar_helper(caller_chan, "TOUCH_MONITOR");
        touch_monitor_prefix = pbx_builtin_getvar_helper(caller_chan, "TOUCH_MONITOR_PREFIX");

        if (!touch_format)
                touch_format = pbx_builtin_getvar_helper(callee_chan, "TOUCH_MONITOR_FORMAT");

        if (!touch_monitor)
                touch_monitor = pbx_builtin_getvar_helper(callee_chan, "TOUCH_MONITOR");

        if (!touch_monitor_prefix)
                touch_monitor_prefix = pbx_builtin_getvar_helper(callee_chan, "TOUCH_MONITOR_PREFIX");

        if (touch_monitor) {
                len = strlen(touch_monitor) + 50;
                args = ast_alloca(len);
                touch_filename = ast_alloca(len);
                snprintf(touch_filename, len, "%s-%ld-%s", S_OR(touch_monitor_prefix, "auto"), (long)time(NULL), touch_monitor);
                snprintf(args, len, "%s,%s,m", S_OR(touch_format, "wav"), touch_filename);
        } else {
                caller_chan_id = ast_strdupa(S_COR(ast_channel_caller(caller_chan)->id.number.valid,
                        ast_channel_caller(caller_chan)->id.number.str, ast_channel_name(caller_chan)));
                callee_chan_id = ast_strdupa(S_COR(ast_channel_caller(callee_chan)->id.number.valid,
                        ast_channel_caller(callee_chan)->id.number.str, ast_channel_name(callee_chan)));
                len = strlen(caller_chan_id) + strlen(callee_chan_id) + 50;
                args = ast_alloca(len);
                touch_filename = ast_alloca(len);
                snprintf(touch_filename, len, "%s-%ld-%s-%s", S_OR(touch_monitor_prefix, "auto"), (long)time(NULL), caller_chan_id, callee_chan_id);
                snprintf(args, len, "%s,%s,m", S_OR(touch_format, "wav"), touch_filename);
        }

        for(x = 0; x < strlen(args); x++) {
                if (args[x] == '/')
                        args[x] = '-';
        }

        ast_verb(4, "User hit '%s' to record call. filename: %s\n", code, args);

        pbx_exec(callee_chan, monitor_app, args);
        pbx_builtin_setvar_helper(callee_chan, "TOUCH_MONITOR_OUTPUT", touch_filename);
        pbx_builtin_setvar_helper(caller_chan, "TOUCH_MONITOR_OUTPUT", touch_filename);

        if (!ast_strlen_zero(automon_message_start)) {  /* Play start message for both channels */
                play_message_in_bridged_call(caller_chan, callee_chan, automon_message_start);
        }

        return AST_FEATURE_RETURN_SUCCESS;
}

static int builtin_automixmonitor(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config, const char *code, int sense, void *data)
{
        char *caller_chan_id = NULL, *callee_chan_id = NULL, *args = NULL, *touch_filename = NULL;
        int x = 0;
        size_t len;
        struct ast_channel *caller_chan, *callee_chan;
        const char *mixmonitor_spy_type = "MixMonitor";
        const char *touch_format;
        const char *touch_monitor;
        struct ast_app *mixmonitor_app;
        int count = 0;

        mixmonitor_app = pbx_findapp("MixMonitor");
        if (!mixmonitor_app) {
                ast_log(LOG_ERROR,"Cannot record the call. The mixmonitor application is disabled.\n");
                return -1;
        }

        set_peers(&caller_chan, &callee_chan, peer, chan, sense);

        if (!ast_strlen_zero(courtesytone)) {
                if (ast_autoservice_start(callee_chan))
                        return -1;
                ast_autoservice_ignore(callee_chan, AST_FRAME_DTMF_END);
                if (ast_stream_and_wait(caller_chan, courtesytone, "")) {
                        ast_log(LOG_WARNING, "Failed to play courtesy tone!\n");
                        ast_autoservice_stop(callee_chan);
                        return -1;
                }
                if (ast_autoservice_stop(callee_chan))
                        return -1;
        }

        ast_channel_lock(callee_chan);
        count = ast_channel_audiohook_count_by_source(callee_chan, mixmonitor_spy_type, AST_AUDIOHOOK_TYPE_SPY);
        ast_channel_unlock(callee_chan);

        /* This means a mixmonitor is attached to the channel, running or not is unknown. */
        if (count > 0) {
                ast_verb(3, "User hit '%s' to stop recording call.\n", code);

                /* Make sure they are running */
                ast_channel_lock(callee_chan);
                count = ast_channel_audiohook_count_by_source_running(callee_chan, mixmonitor_spy_type, AST_AUDIOHOOK_TYPE_SPY);
                ast_channel_unlock(callee_chan);
                if (count > 0) {
                        struct ast_app *stopmixmonitor_app;

                        stopmixmonitor_app = pbx_findapp("StopMixMonitor");
                        if (!stopmixmonitor_app) {
                                ast_log(LOG_ERROR,"Cannot stop recording the call. The stopmixmonitor application is disabled.\n");
                                return -1;
                        }
                        pbx_exec(callee_chan, stopmixmonitor_app, "");
                        return AST_FEATURE_RETURN_SUCCESS;
                }

                ast_log(LOG_WARNING,"Stopped MixMonitors are attached to the channel.\n");
        }

        touch_format = pbx_builtin_getvar_helper(caller_chan, "TOUCH_MIXMONITOR_FORMAT");
        touch_monitor = pbx_builtin_getvar_helper(caller_chan, "TOUCH_MIXMONITOR");

        if (!touch_format)
                touch_format = pbx_builtin_getvar_helper(callee_chan, "TOUCH_MIXMONITOR_FORMAT");

        if (!touch_monitor)
                touch_monitor = pbx_builtin_getvar_helper(callee_chan, "TOUCH_MIXMONITOR");

        if (touch_monitor) {
                len = strlen(touch_monitor) + 50;
                args = ast_alloca(len);
                touch_filename = ast_alloca(len);
                snprintf(touch_filename, len, "auto-%ld-%s", (long)time(NULL), touch_monitor);
                snprintf(args, len, "%s.%s,b", touch_filename, (touch_format) ? touch_format : "wav");
        } else {
                caller_chan_id = ast_strdupa(S_COR(ast_channel_caller(caller_chan)->id.number.valid,
                        ast_channel_caller(caller_chan)->id.number.str, ast_channel_name(caller_chan)));
                callee_chan_id = ast_strdupa(S_COR(ast_channel_caller(callee_chan)->id.number.valid,
                        ast_channel_caller(callee_chan)->id.number.str, ast_channel_name(callee_chan)));
                len = strlen(caller_chan_id) + strlen(callee_chan_id) + 50;
                args = ast_alloca(len);
                touch_filename = ast_alloca(len);
                snprintf(touch_filename, len, "auto-%ld-%s-%s", (long)time(NULL), caller_chan_id, callee_chan_id);
                snprintf(args, len, "%s.%s,b", touch_filename, S_OR(touch_format, "wav"));
        }

        for( x = 0; x < strlen(args); x++) {
                if (args[x] == '/')
                        args[x] = '-';
        }

        ast_verb(3, "User hit '%s' to record call. filename: %s\n", code, touch_filename);

        pbx_exec(callee_chan, mixmonitor_app, args);
        pbx_builtin_setvar_helper(callee_chan, "TOUCH_MIXMONITOR_OUTPUT", touch_filename);
        pbx_builtin_setvar_helper(caller_chan, "TOUCH_MIXMONITOR_OUTPUT", touch_filename);
        return AST_FEATURE_RETURN_SUCCESS;
}

static int builtin_disconnect(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config, const char *code, int sense, void *data)
{
        ast_verb(4, "User hit '%s' to disconnect call.\n", code);
        return AST_FEATURE_RETURN_HANGUP;
}

/*!
 * \brief Find the context for the transfer
 * \param transferer
 * \param transferee
 *
 * Grab the TRANSFER_CONTEXT, if fails try grabbing macrocontext.
 * \return a context string
 */
static const char *real_ctx(struct ast_channel *transferer, struct ast_channel *transferee)
{
        const char *s = pbx_builtin_getvar_helper(transferer, "TRANSFER_CONTEXT");
        if (ast_strlen_zero(s)) {
                s = pbx_builtin_getvar_helper(transferee, "TRANSFER_CONTEXT");
        }
        if (ast_strlen_zero(s)) { /* Use the non-macro context to transfer the call XXX ? */
                s = ast_channel_macrocontext(transferer);
        }
        if (ast_strlen_zero(s)) {
                s = ast_channel_context(transferer);
        }
        return s;
}

/*!
 * \brief Blind transfer user to another extension
 * \param chan channel to be transfered
 * \param peer channel initiated blind transfer
 * \param config
 * \param code
 * \param data
 * \param sense  feature options
 *
 * Place chan on hold, check if transferred to parkinglot extension,
 * otherwise check extension exists and transfer caller.
 * \retval AST_FEATURE_RETURN_SUCCESS.
 * \retval -1 on failure.
 */
static int builtin_blindtransfer(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config, const char *code, int sense, void *data)
{
        struct ast_channel *transferer;
        struct ast_channel *transferee;
        struct ast_exten *park_exten;
        const char *transferer_real_context;
        char xferto[256] = "";
        int res;

        ast_debug(1, "Executing Blind Transfer %s, %s (sense=%d) \n", ast_channel_name(chan), ast_channel_name(peer), sense);
        set_peers(&transferer, &transferee, peer, chan, sense);
        transferer_real_context = ast_strdupa(real_ctx(transferer, transferee));

        /* Start autoservice on transferee while we talk to the transferer */
        ast_autoservice_start(transferee);
        ast_indicate(transferee, AST_CONTROL_HOLD);

        /* Transfer */
        res = ast_stream_and_wait(transferer, "pbx-transfer", AST_DIGIT_ANY);
        if (res < 0) {
                finishup(transferee);
                return -1; /* error ? */
        }
        if (res > 0) { /* If they've typed a digit already, handle it */
                xferto[0] = (char) res;
        }

        res = ast_app_dtget(transferer, transferer_real_context, xferto, sizeof(xferto), 100, transferdigittimeout);
        if (res < 0) {  /* hangup or error, (would be 0 for invalid and 1 for valid) */
                finishup(transferee);
                return -1;
        }
        if (res == 0) {
                if (xferto[0]) {
                        ast_log(LOG_WARNING, "Extension '%s' does not exist in context '%s'\n",
                                xferto, transferer_real_context);
                } else {
                        /* Does anyone care about this case? */
                        ast_log(LOG_WARNING, "No digits dialed.\n");
                }
                ast_stream_and_wait(transferer, "pbx-invalid", "");
                finishup(transferee);
                return AST_FEATURE_RETURN_SUCCESS;
        }

        park_exten = get_parking_exten(xferto, transferer, transferer_real_context);
        if (park_exten) {
                /* We are transfering the transferee to a parking lot. */
                return xfer_park_call_helper(transferee, transferer, park_exten);
        }

        /* Do blind transfer. */
        ast_verb(3, "Blind transferring %s to '%s' (context %s) priority 1\n",
                ast_channel_name(transferee), xferto, transferer_real_context);
        ast_cel_report_event(transferer, AST_CEL_BLINDTRANSFER, NULL, xferto, transferee);
        pbx_builtin_setvar_helper(transferer, "BLINDTRANSFER", ast_channel_name(transferee));
        pbx_builtin_setvar_helper(transferee, "BLINDTRANSFER", ast_channel_name(transferer));
        finishup(transferee);
        ast_channel_lock(transferer);
        if (!ast_channel_cdr(transferer)) {
                /* this code should never get called (in a perfect world) */
                ast_channel_cdr_set(transferer, ast_cdr_alloc());
                if (ast_channel_cdr(transferer)) {
                        ast_cdr_init(ast_channel_cdr(transferer), transferer); /* initialize our channel's cdr */
                        ast_cdr_start(ast_channel_cdr(transferer));
                }
        }
        ast_channel_unlock(transferer);
        if (ast_channel_cdr(transferer)) {
                struct ast_cdr *swap = ast_channel_cdr(transferer);

                ast_debug(1,
                        "transferer=%s; transferee=%s; lastapp=%s; lastdata=%s; chan=%s; dstchan=%s\n",
                        ast_channel_name(transferer), ast_channel_name(transferee), ast_channel_cdr(transferer)->lastapp,
                        ast_channel_cdr(transferer)->lastdata, ast_channel_cdr(transferer)->channel,
                        ast_channel_cdr(transferer)->dstchannel);
                ast_debug(1, "TRANSFEREE; lastapp=%s; lastdata=%s, chan=%s; dstchan=%s\n",
                        ast_channel_cdr(transferee)->lastapp, ast_channel_cdr(transferee)->lastdata, ast_channel_cdr(transferee)->channel,
                        ast_channel_cdr(transferee)->dstchannel);
                ast_debug(1, "transferer_real_context=%s; xferto=%s\n",
                        transferer_real_context, xferto);
                /* swap cdrs-- it will save us some time & work */
                ast_channel_cdr_set(transferer, ast_channel_cdr(transferee));
                ast_channel_cdr_set(transferee, swap);
        }

        res = ast_channel_pbx(transferee) ? AST_FEATURE_RETURN_SUCCESSBREAK : -1;

        /* Doh!  Use our handy async_goto functions */
        if (ast_async_goto(transferee, transferer_real_context, xferto, 1)) {
                ast_log(LOG_WARNING, "Async goto failed :-(\n");
                res = -1;
        }
        check_goto_on_transfer(transferer);
        return res;
}

/*!
 * \brief make channels compatible
 * \param c
 * \param newchan
 * \retval 0 on success.
 * \retval -1 on failure.
 */
static int check_compat(struct ast_channel *c, struct ast_channel *newchan)
{
        if (ast_channel_make_compatible(c, newchan) < 0) {
                ast_log(LOG_WARNING, "Had to drop call because I couldn't make %s compatible with %s\n",
                        ast_channel_name(c), ast_channel_name(newchan));
                ast_autoservice_chan_hangup_peer(c, newchan);
                return -1;
        }
        return 0;
}

/*!
 * \internal
 * \brief Builtin attended transfer failed cleanup.
 * \since 10.0
 *
 * \param transferee Party A in the transfer.
 * \param transferer Party B in the transfer.
 * \param connected_line Saved connected line info about party A.
 *
 * \note The connected_line data is freed.
 *
 * \return Nothing
 */
static void atxfer_fail_cleanup(struct ast_channel *transferee, struct ast_channel *transferer, struct ast_party_connected_line *connected_line)
{
        finishup(transferee);

        /*
         * Restore party B connected line info about party A.
         *
         * Party B was the caller to party C and is the last known mode
         * for party B.
         */
        if (ast_channel_connected_line_sub(transferee, transferer, connected_line, 0) &&
                ast_channel_connected_line_macro(transferee, transferer, connected_line, 1, 0)) {
                ast_channel_update_connected_line(transferer, connected_line, NULL);
        }
        ast_party_connected_line_free(connected_line);
}

/*!
 * \brief Attended transfer
 * \param chan transfered user
 * \param peer person transfering call
 * \param config
 * \param code
 * \param sense feature options
 *
 * \param data
 * Get extension to transfer to, if you cannot generate channel (or find extension)
 * return to host channel. After called channel answered wait for hangup of transferer,
 * bridge call between transfer peer (taking them off hold) to attended transfer channel.
 *
 * \return -1 on failure
 */
static int builtin_atxfer(struct ast_channel *chan, struct ast_channel *peer, struct ast_bridge_config *config, const char *code, int sense, void *data)
{
        struct ast_channel *transferer;/* Party B */
        struct ast_channel *transferee;/* Party A */
        struct ast_exten *park_exten;
        const char *chan1_attended_sound;
        const char *chan2_attended_sound;
        const char *transferer_real_context;
        char xferto[256] = "";
        int res;
        int outstate=0;
        struct ast_channel *newchan;
        struct ast_channel *xferchan;
        struct ast_bridge_thread_obj *tobj;
        struct ast_bridge_config bconfig;
        int l;
        struct ast_party_connected_line connected_line;
        struct ast_datastore *features_datastore;
        struct ast_dial_features *dialfeatures;
        char *transferer_tech;
        char *transferer_name;
        char *transferer_name_orig;
        char *dash;

        ast_debug(1, "Executing Attended Transfer %s, %s (sense=%d) \n", ast_channel_name(chan), ast_channel_name(peer), sense);
        set_peers(&transferer, &transferee, peer, chan, sense);
        transferer_real_context = real_ctx(transferer, transferee);

        /* Start autoservice on transferee while we talk to the transferer */
        ast_autoservice_start(transferee);
        ast_indicate(transferee, AST_CONTROL_HOLD);

        /* Transfer */
        res = ast_stream_and_wait(transferer, "pbx-transfer", AST_DIGIT_ANY);
        if (res < 0) {
                finishup(transferee);
                return -1;
        }
        if (res > 0) { /* If they've typed a digit already, handle it */
                xferto[0] = (char) res;
        }

        /* this is specific of atxfer */
        res = ast_app_dtget(transferer, transferer_real_context, xferto, sizeof(xferto), 100, transferdigittimeout);
        if (res < 0) {  /* hangup or error, (would be 0 for invalid and 1 for valid) */
                finishup(transferee);
                return -1;
        }
        l = strlen(xferto);
        if (res == 0) {
                if (l) {
                        ast_log(LOG_WARNING, "Extension '%s' does not exist in context '%s'\n",
                                xferto, transferer_real_context);
                } else {
                        /* Does anyone care about this case? */
                        ast_log(LOG_WARNING, "No digits dialed for atxfer.\n");
                }
                ast_stream_and_wait(transferer, "pbx-invalid", "");
                finishup(transferee);
                return AST_FEATURE_RETURN_SUCCESS;
        }

        park_exten = get_parking_exten(xferto, transferer, transferer_real_context);
        if (park_exten) {
                /* We are transfering the transferee to a parking lot. */
                return xfer_park_call_helper(transferee, transferer, park_exten);
        }

        /*
         * Append context to dialed transfer number.
         *
         * NOTE: The local channel needs the /n flag so party C will use
         * the feature flags set by the dialplan when calling that
         * party.
         */
        snprintf(xferto + l, sizeof(xferto) - l, "@%s/n", transferer_real_context);

        /* If we are performing an attended transfer and we have two channels involved then
           copy sound file information to play upon attended transfer completion */
        chan1_attended_sound = pbx_builtin_getvar_helper(transferer, "ATTENDED_TRANSFER_COMPLETE_SOUND");
        chan2_attended_sound = pbx_builtin_getvar_helper(transferee, "ATTENDED_TRANSFER_COMPLETE_SOUND");
        if (!ast_strlen_zero(chan1_attended_sound)) {
                pbx_builtin_setvar_helper(transferer, "BRIDGE_PLAY_SOUND", chan1_attended_sound);
        }
        if (!ast_strlen_zero(chan2_attended_sound)) {
                pbx_builtin_setvar_helper(transferee, "BRIDGE_PLAY_SOUND", chan2_attended_sound);
        }

        /* Extract redial transferer information from the channel name. */
        transferer_name_orig = ast_strdupa(ast_channel_name(transferer));
        transferer_name = ast_strdupa(transferer_name_orig);
        transferer_tech = strsep(&transferer_name, "/");
        dash = strrchr(transferer_name, '-');
        if (dash) {
                /* Trim off channel name sequence/serial number. */
                *dash = '\0';
        }

        /* Stop autoservice so we can monitor all parties involved in the transfer. */
        if (ast_autoservice_stop(transferee) < 0) {
                ast_indicate(transferee, AST_CONTROL_UNHOLD);
                return -1;
        }

        /* Save connected line info for party B about party A in case transfer fails. */
        ast_party_connected_line_init(&connected_line);
        ast_channel_lock(transferer);
        ast_party_connected_line_copy(&connected_line, ast_channel_connected(transferer));
        ast_channel_unlock(transferer);
        connected_line.source = AST_CONNECTED_LINE_UPDATE_SOURCE_TRANSFER;

        /* Dial party C */
        newchan = feature_request_and_dial(transferer, transferer_name_orig, transferer,
                transferee, "Local", ast_channel_nativeformats(transferer), xferto,
                atxfernoanswertimeout, &outstate, ast_channel_language(transferer));
        ast_debug(2, "Dial party C result: newchan:%d, outstate:%d\n", !!newchan, outstate);

        if (!ast_check_hangup(transferer)) {
                /* Transferer (party B) is up */
                ast_debug(1, "Actually doing an attended transfer.\n");

                /* Start autoservice on transferee while the transferer deals with party C. */
                ast_autoservice_start(transferee);

                ast_indicate(transferer, -1);
                if (!newchan) {
                        /* any reason besides user requested cancel and busy triggers the failed sound */
                        switch (outstate) {
                        case AST_CONTROL_UNHOLD:/* Caller requested cancel or party C answer timeout. */
                        case AST_CONTROL_BUSY:
                        case AST_CONTROL_CONGESTION:
                                if (ast_stream_and_wait(transferer, xfersound, "")) {
                                        ast_log(LOG_WARNING, "Failed to play transfer sound!\n");
                                }
                                break;
                        default:
                                if (ast_stream_and_wait(transferer, xferfailsound, "")) {
                                        ast_log(LOG_WARNING, "Failed to play transfer failed sound!\n");
                                }
                                break;
                        }
                        atxfer_fail_cleanup(transferee, transferer, &connected_line);
                        return AST_FEATURE_RETURN_SUCCESS;
                }

                if (check_compat(transferer, newchan)) {
                        if (ast_stream_and_wait(transferer, xferfailsound, "")) {
                                ast_log(LOG_WARNING, "Failed to play transfer failed sound!\n");
                        }
                        atxfer_fail_cleanup(transferee, transferer, &connected_line);
                        return AST_FEATURE_RETURN_SUCCESS;
                }
                memset(&bconfig,0,sizeof(struct ast_bridge_config));
                ast_set_flag(&(bconfig.features_caller), AST_FEATURE_DISCONNECT);
                ast_set_flag(&(bconfig.features_callee), AST_FEATURE_DISCONNECT);

                /*
                 * Let party B and C talk as long as they want while party A
                 * languishes in autoservice listening to MOH.
                 */
                ast_bridge_call(transferer, newchan, &bconfig);

                if (ast_check_hangup(newchan) || !ast_check_hangup(transferer)) {
                        ast_autoservice_chan_hangup_peer(transferer, newchan);
                        if (ast_stream_and_wait(transferer, xfersound, "")) {
                                ast_log(LOG_WARNING, "Failed to play transfer sound!\n");
                        }
                        atxfer_fail_cleanup(transferee, transferer, &connected_line);
                        return AST_FEATURE_RETURN_SUCCESS;
                }

                /* Transferer (party B) is confirmed hung up at this point. */
                if (check_compat(transferee, newchan)) {
                        finishup(transferee);
                        ast_party_connected_line_free(&connected_line);
                        return -1;
                }

                ast_indicate(transferee, AST_CONTROL_UNHOLD);
                if ((ast_autoservice_stop(transferee) < 0)
                        || (ast_waitfordigit(transferee, 100) < 0)
                        || (ast_waitfordigit(newchan, 100) < 0)
                        || ast_check_hangup(transferee)
                        || ast_check_hangup(newchan)) {
                        ast_hangup(newchan);
                        ast_party_connected_line_free(&connected_line);
                        return -1;
                }
        } else if (!ast_check_hangup(transferee)) {
                /* Transferer (party B) has hung up at this point.  Doing blonde transfer. */
                ast_debug(1, "Actually doing a blonde transfer.\n");

                if (!newchan && !atxferdropcall) {
                        /* Party C is not available, try to call party B back. */
                        unsigned int tries = 0;

                        if (ast_strlen_zero(transferer_name) || ast_strlen_zero(transferer_tech)) {
                                ast_log(LOG_WARNING,
                                        "Transferer channel name: '%s' cannot be used for callback.\n",
                                        transferer_name_orig);
                                ast_indicate(transferee, AST_CONTROL_UNHOLD);
                                ast_party_connected_line_free(&connected_line);
                                return -1;
                        }

                        tries = 0;
                        for (;;) {
                                /* Try to get party B back. */
                                ast_debug(1, "We're trying to callback %s/%s\n",
                                        transferer_tech, transferer_name);
                                newchan = feature_request_and_dial(transferer, transferer_name_orig,
                                        transferee, transferee, transferer_tech,
                                        ast_channel_nativeformats(transferee), transferer_name,
                                        atxfernoanswertimeout, &outstate, ast_channel_language(transferer));
                                ast_debug(2, "Dial party B result: newchan:%d, outstate:%d\n",
                                        !!newchan, outstate);
                                if (newchan) {
                                        /*
                                         * We have recalled party B (newchan).  We need to give this
                                         * call leg the same feature flags as the original party B call
                                         * leg.
                                         */
                                        ast_channel_lock(transferer);
                                        features_datastore = ast_channel_datastore_find(transferer,
                                                &dial_features_info, NULL);
                                        if (features_datastore && (dialfeatures = features_datastore->data)) {
                                                struct ast_flags my_features = { 0 };
                                                struct ast_flags peer_features = { 0 };

                                                ast_copy_flags(&my_features, &dialfeatures->my_features,
                                                        AST_FLAGS_ALL);
                                                ast_copy_flags(&peer_features, &dialfeatures->peer_features,
                                                        AST_FLAGS_ALL);
                                                ast_channel_unlock(transferer);
                                                add_features_datastore(newchan, &my_features, &peer_features);
                                        } else {
                                                ast_channel_unlock(transferer);
                                        }
                                        break;
                                }
                                if (ast_check_hangup(transferee)) {
                                        break;
                                }

                                ++tries;
                                if (atxfercallbackretries <= tries) {
                                        /* No more callback tries remaining. */
                                        break;
                                }

                                if (atxferloopdelay) {
                                        /* Transfer failed, sleeping */
                                        ast_debug(1, "Sleeping for %d ms before retrying atxfer.\n",
                                                atxferloopdelay);
                                        ast_safe_sleep(transferee, atxferloopdelay);
                                        if (ast_check_hangup(transferee)) {
                                                ast_party_connected_line_free(&connected_line);
                                                return -1;
                                        }
                                }

                                /* Retry dialing party C. */
                                ast_debug(1, "We're retrying to call %s/%s\n", "Local", xferto);
                                newchan = feature_request_and_dial(transferer, transferer_name_orig,
                                        transferer, transferee, "Local",
                                        ast_channel_nativeformats(transferee), xferto,
                                        atxfernoanswertimeout, &outstate, ast_channel_language(transferer));
                                ast_debug(2, "Redial party C result: newchan:%d, outstate:%d\n",
                                        !!newchan, outstate);
                                if (newchan || ast_check_hangup(transferee)) {
                                        break;
                                }
                        }
                }
                ast_indicate(transferee, AST_CONTROL_UNHOLD);
                if (!newchan) {
                        /* No party C or could not callback party B. */
                        ast_party_connected_line_free(&connected_line);
                        return -1;
                }

                /* newchan is up, we should prepare transferee and bridge them */
                if (ast_check_hangup(newchan)) {
                        ast_autoservice_chan_hangup_peer(transferee, newchan);
                        ast_party_connected_line_free(&connected_line);
                        return -1;
                }
                if (check_compat(transferee, newchan)) {
                        ast_party_connected_line_free(&connected_line);
                        return -1;
                }
        } else {
                /*
                 * Both the transferer and transferee have hungup.  If newchan
                 * is up, hang it up as it has no one to talk to.
                 */
                ast_debug(1, "Everyone is hungup.\n");
                if (newchan) {
                        ast_hangup(newchan);
                }
                ast_party_connected_line_free(&connected_line);
                return -1;
        }

        /* Initiate the channel transfer of party A to party C (or recalled party B). */
        ast_cel_report_event(transferee, AST_CEL_ATTENDEDTRANSFER, NULL, NULL, newchan);

        xferchan = ast_channel_alloc(0, AST_STATE_DOWN, 0, 0, "", "", "", ast_channel_linkedid(transferee), 0, "Transfered/%s", ast_channel_name(transferee));
        if (!xferchan) {
                ast_autoservice_chan_hangup_peer(transferee, newchan);
                ast_party_connected_line_free(&connected_line);
                return -1;
        }

        /* Give party A a momentary ringback tone during transfer. */
        ast_channel_visible_indication_set(xferchan, AST_CONTROL_RINGING);

        /* Make formats okay */
        ast_format_copy(ast_channel_readformat(xferchan), ast_channel_readformat(transferee));
        ast_format_copy(ast_channel_writeformat(xferchan), ast_channel_writeformat(transferee));

        if (ast_channel_masquerade(xferchan, transferee)) {
                ast_hangup(xferchan);
                ast_autoservice_chan_hangup_peer(transferee, newchan);
                ast_party_connected_line_free(&connected_line);
                return -1;
        }

        dash = strrchr(xferto, '@');
        if (dash) {
                /* Trim off the context. */
                *dash = '\0';
        }
        ast_explicit_goto(xferchan, transferer_real_context, xferto, 1);
        ast_channel_state_set(xferchan, AST_STATE_UP);
        ast_clear_flag(ast_channel_flags(xferchan), AST_FLAGS_ALL);

        /* Do the masquerade manually to make sure that is is completed. */
        ast_do_masquerade(xferchan);

        ast_channel_state_set(newchan, AST_STATE_UP);
        ast_clear_flag(ast_channel_flags(newchan), AST_FLAGS_ALL);
        tobj = ast_calloc(1, sizeof(*tobj));
        if (!tobj) {
                ast_hangup(xferchan);
                ast_hangup(newchan);
                ast_party_connected_line_free(&connected_line);
                return -1;
        }

        tobj->chan = newchan;
        tobj->peer = xferchan;
        tobj->bconfig = *config;

        ast_channel_lock(newchan);
        features_datastore = ast_channel_datastore_find(newchan, &dial_features_info, NULL);
        if (features_datastore && (dialfeatures = features_datastore->data)) {
                ast_copy_flags(&tobj->bconfig.features_callee, &dialfeatures->my_features,
                        AST_FLAGS_ALL);
        }
        ast_channel_unlock(newchan);

        ast_channel_lock(xferchan);
        features_datastore = ast_channel_datastore_find(xferchan, &dial_features_info, NULL);
        if (features_datastore && (dialfeatures = features_datastore->data)) {
                ast_copy_flags(&tobj->bconfig.features_caller, &dialfeatures->my_features,
                        AST_FLAGS_ALL);
        }
        ast_channel_unlock(xferchan);

        if (tobj->bconfig.end_bridge_callback_data_fixup) {
                tobj->bconfig.end_bridge_callback_data_fixup(&tobj->bconfig, tobj->peer, tobj->chan);
        }

        /*
         * xferchan is transferee, and newchan is the transfer target
         * So...in a transfer, who is the caller and who is the callee?
         *
         * When the call is originally made, it is clear who is caller and callee.
         * When a transfer occurs, it is my humble opinion that the transferee becomes
         * the caller, and the transfer target is the callee.
         *
         * The problem is that these macros were set with the intention of the original
         * caller and callee taking those roles.  A transfer can totally mess things up,
         * to be technical.  What sucks even more is that you can't effectively change
         * the macros in the dialplan during the call from the transferer to the transfer
         * target because the transferee is stuck with whatever role he originally had.
         *
         * I think the answer here is just to make sure that it is well documented that
         * during a transfer, the transferee is the "caller" and the transfer target
         * is the "callee."
         *
         * This means that if party B calls party A, and party B transfers party A to
         * party C, then A has switched roles for the call.  Now party A will have the
         * caller macro called on his channel instead of the callee macro.
         *
         * Luckily, the method by which the party B to party C bridge is
         * launched above ensures that the transferee is the "chan" on
         * the bridge and the transfer target is the "peer," so my idea
         * for the roles post-transfer does not require extensive code
         * changes.
         */

        /* Transfer party C connected line to party A */
        ast_channel_lock(transferer);
        /*
         * Due to a limitation regarding when callerID is set on a Local channel,
         * we use the transferer's connected line information here.
         */
        ast_party_connected_line_copy(&connected_line, ast_channel_connected(transferer));
        ast_channel_unlock(transferer);
        connected_line.source = AST_CONNECTED_LINE_UPDATE_SOURCE_TRANSFER;
        if (ast_channel_connected_line_sub(newchan, xferchan, &connected_line, 0) &&
                ast_channel_connected_line_macro(newchan, xferchan, &connected_line, 1, 0)) {
                ast_channel_update_connected_line(xferchan, &connected_line, NULL);
        }

        /* Transfer party A connected line to party C */
        ast_channel_lock(xferchan);
        ast_connected_line_copy_from_caller(&connected_line, ast_channel_caller(xferchan));
        ast_channel_unlock(xferchan);
        connected_line.source = AST_CONNECTED_LINE_UPDATE_SOURCE_TRANSFER;
        if (ast_channel_connected_line_sub(xferchan, newchan, &connected_line, 0) &&
                ast_channel_connected_line_macro(xferchan, newchan, &connected_line, 0, 0)) {
                ast_channel_update_connected_line(newchan, &connected_line, NULL);
        }

        if (ast_stream_and_wait(newchan, xfersound, ""))
                ast_log(LOG_WARNING, "Failed to play transfer sound!\n");
        bridge_call_thread_launch(tobj);

        ast_party_connected_line_free(&connected_line);
        return -1;/* The transferee is masqueraded and the original bridged channels can be hungup. */
}

/* add atxfer and automon as undefined so you can only use em if you configure them */
#define FEATURES_COUNT ARRAY_LEN(builtin_features)

AST_RWLOCK_DEFINE_STATIC(features_lock);

/*! \note This is protected by features_lock. */
static AST_LIST_HEAD_NOLOCK_STATIC(feature_list, ast_call_feature);

static void ast_wrlock_call_features(void)
{
        ast_rwlock_wrlock(&features_lock);
}

void ast_rdlock_call_features(void)
{
        ast_rwlock_rdlock(&features_lock);
}

void ast_unlock_call_features(void)
{
        ast_rwlock_unlock(&features_lock);
}

/*! \note This is protected by features_lock. */
static struct ast_call_feature builtin_features[] = {
        { AST_FEATURE_REDIRECT, "Blind Transfer", "blindxfer", "#", "#", builtin_blindtransfer, AST_FEATURE_FLAG_NEEDSDTMF, "" },
        { AST_FEATURE_REDIRECT, "Attended Transfer", "atxfer", "", "", builtin_atxfer, AST_FEATURE_FLAG_NEEDSDTMF, "" },
        { AST_FEATURE_AUTOMON, "One Touch Monitor", "automon", "", "", builtin_automonitor, AST_FEATURE_FLAG_NEEDSDTMF, "" },
        { AST_FEATURE_DISCONNECT, "Disconnect Call", "disconnect", "*", "*", builtin_disconnect, AST_FEATURE_FLAG_NEEDSDTMF, "" },
        { AST_FEATURE_PARKCALL, "Park Call", "parkcall", "", "", builtin_parkcall, AST_FEATURE_FLAG_NEEDSDTMF, "" },
        { AST_FEATURE_AUTOMIXMON, "One Touch MixMonitor", "automixmon", "", "", builtin_automixmonitor, AST_FEATURE_FLAG_NEEDSDTMF, "" },
};

/*! \brief register new feature into feature_list */
void ast_register_feature(struct ast_call_feature *feature)
{
        if (!feature) {
                ast_log(LOG_NOTICE,"You didn't pass a feature!\n");
                return;
        }

        ast_wrlock_call_features();
        AST_LIST_INSERT_HEAD(&feature_list, feature, feature_entry);
        ast_unlock_call_features();

        ast_verb(2, "Registered Feature '%s'\n",feature->sname);
}

/*!
 * \brief Add new feature group
 * \param fgname feature group name.
 *
 * Add new feature group to the feature group list insert at head of list.
 * \note This function MUST be called while feature_groups is locked.
 */
static struct feature_group *register_group(const char *fgname)
{
        struct feature_group *fg;

        if (!fgname) {
                ast_log(LOG_NOTICE, "You didn't pass a new group name!\n");
                return NULL;
        }

        if (!(fg = ast_calloc_with_stringfields(1, struct feature_group, 128))) {
                return NULL;
        }

        ast_string_field_set(fg, gname, fgname);

        AST_LIST_INSERT_HEAD(&feature_groups, fg, entry);

        ast_verb(2, "Registered group '%s'\n", fg->gname);

        return fg;
}

/*!
 * \brief Add feature to group
 * \param fg feature group
 * \param exten
 * \param feature feature to add.
 *
 * Check fg and feature specified, add feature to list
 * \note This function MUST be called while feature_groups is locked.
 */
static void register_group_feature(struct feature_group *fg, const char *exten, struct ast_call_feature *feature)
{
        struct feature_group_exten *fge;

        if (!fg) {
                ast_log(LOG_NOTICE, "You didn't pass a group!\n");
                return;
        }

        if (!feature) {
                ast_log(LOG_NOTICE, "You didn't pass a feature!\n");
                return;
        }

        if (!(fge = ast_calloc_with_stringfields(1, struct feature_group_exten, 128))) {
                return;
        }

        ast_string_field_set(fge, exten, S_OR(exten, feature->exten));

        fge->feature = feature;

        AST_LIST_INSERT_HEAD(&fg->features, fge, entry);

        ast_verb(2, "Registered feature '%s' for group '%s' at exten '%s'\n",
                                        feature->sname, fg->gname, fge->exten);
}

void ast_unregister_feature(struct ast_call_feature *feature)
{
        if (!feature) {
                return;
        }

        ast_wrlock_call_features();
        AST_LIST_REMOVE(&feature_list, feature, feature_entry);
        ast_unlock_call_features();

        ast_free(feature);
}

/*! \brief Remove all features in the list */
static void ast_unregister_features(void)
{
        struct ast_call_feature *feature;

        ast_wrlock_call_features();
        while ((feature = AST_LIST_REMOVE_HEAD(&feature_list, feature_entry))) {
                ast_free(feature);
        }
        ast_unlock_call_features();
}

/*!
 * \internal
 * \brief find a dynamic call feature by name
 * \pre Expects features_lock to be at least readlocked
 */
static struct ast_call_feature *find_dynamic_feature(const char *name)
{
        struct ast_call_feature *tmp;

        AST_LIST_TRAVERSE(&feature_list, tmp, feature_entry) {
                if (!strcasecmp(tmp->sname, name)) {
                        break;
                }
        }

        return tmp;
}

/*! \brief Remove all feature groups in the list */
static void ast_unregister_groups(void)