app_directed_pickup.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2005, Joshua Colp
 *
 * Joshua Colp <jcolp@digium.com>
 *
 * Portions merged from app_pickupchan, which was
 * Copyright (C) 2008, Gary Cook
 *
 * 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 Directed Call Pickup Support
 *
 * \author Joshua Colp <jcolp@digium.com>
 * \author Gary Cook
 *
 * \ingroup applications
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/lock.h"
#include "asterisk/app.h"
#include "asterisk/pickup.h"
#include "asterisk/manager.h"
#include "asterisk/callerid.h"
 
#define PICKUPMARK "PICKUPMARK"
 
/*** DOCUMENTATION
    <application name="Pickup" language="en_US">
        <synopsis>
            Directed extension call pickup.
        </synopsis>
        <syntax>
            <parameter name="targets" argsep="&amp;">
                <argument name="extension" argsep="@" required="true">
                    <para>Specification of the pickup target.</para>
                    <argument name="extension" required="true"/>
                    <argument name="context" />
                </argument>
                <argument name="extension2" argsep="@" multiple="true">
                    <para>Additional specifications of pickup targets.</para>
                    <argument name="extension2" required="true"/>
                    <argument name="context2"/>
                </argument>
            </parameter>
        </syntax>
        <description>
            <para>This application can pickup a specified ringing channel.  The channel
            to pickup can be specified in the following ways.</para>
            <para>1) If no <replaceable>extension</replaceable> targets are specified,
            the application will pickup a channel matching the pickup group of the
            requesting channel.</para>
            <para>2) If the <replaceable>extension</replaceable> is specified with a
            <replaceable>context</replaceable> of the special string
            <literal>PICKUPMARK</literal> (for example 10@PICKUPMARK), the application
            will pickup a channel which has defined the channel variable
            <variable>PICKUPMARK</variable> with the same value as
            <replaceable>extension</replaceable> (in this example,
            <literal>10</literal>).</para>
            <para>3) If the <replaceable>extension</replaceable> is specified
            with or without a <replaceable>context</replaceable>, the channel with a
            matching <replaceable>extension</replaceable> and <replaceable>context</replaceable>
            will be picked up.  If no <replaceable>context</replaceable> is specified,
            the current context will be used.</para>
            <note><para>The <replaceable>extension</replaceable> is typically set on
            matching channels by the dial application that created the channel.  The
            <replaceable>context</replaceable> is set on matching channels by the
            channel driver for the device.</para></note>
        </description>
    </application>
    <application name="PickupChan" language="en_US">
        <synopsis>
            Pickup a ringing channel.
        </synopsis>
        <syntax >
            <parameter name="channel" argsep="&amp;" required="true">
                <argument name="channel" required="true" />
                <argument name="channel2" required="false" multiple="true" />
                <para>List of channel names or channel uniqueids to pickup if ringing.
                    For example, a channel name could be <literal>SIP/bob</literal> or
                    <literal>SIP/bob-00000000</literal> to find
                    <literal>SIP/bob-00000000</literal>.
                </para>
            </parameter>
            <parameter name="options" required="false">
                <optionlist>
                    <option name="p">
                        <para>Supplied channel names are prefixes.  For example,
                            <literal>SIP/bob</literal> will match
                            <literal>SIP/bob-00000000</literal> and
                            <literal>SIP/bobby-00000000</literal>.
                        </para>
                    </option>
                </optionlist>
            </parameter>
        </syntax>
        <description>
            <para>Pickup a specified <replaceable>channel</replaceable> if ringing.</para>
        </description>
    </application>
 ***/
 
static const char app[] = "Pickup";
static const char app2[] = "PickupChan";
 
struct pickup_by_name_args {
    /*! Channel attempting to pickup a call. */
    struct ast_channel *chan;
    /*! Channel uniqueid or partial channel name to match. */
    const char *name;
    /*! Length of partial channel name to match. */
    size_t len;
};
 
static int find_by_name(void *obj, void *arg, void *data, int flags)
{
    struct ast_channel *target = obj;/*!< Potential pickup target */
    struct pickup_by_name_args *args = data;
 
    if (args->chan == target) {
        /* The channel attempting to pickup a call cannot pickup itself. */
        return 0;
    }
 
    ast_channel_lock(target);
    if (!strncasecmp(ast_channel_name(target), args->name, args->len)
        && ast_can_pickup(target)) {
        /* Return with the channel still locked on purpose */
        return CMP_MATCH | CMP_STOP;
    }
    ast_channel_unlock(target);
 
    return 0;
}
 
static int find_by_uniqueid(void *obj, void *arg, void *data, int flags)
{
    struct ast_channel *target = obj;/*!< Potential pickup target */
    struct pickup_by_name_args *args = data;
 
    if (args->chan == target) {
        /* The channel attempting to pickup a call cannot pickup itself. */
        return 0;
    }
 
    ast_channel_lock(target);
    if (!strcasecmp(ast_channel_uniqueid(target), args->name)
        && ast_can_pickup(target)) {
        /* Return with the channel still locked on purpose */
        return CMP_MATCH | CMP_STOP;
    }
    ast_channel_unlock(target);
 
    return 0;
}
 
/*! \brief Helper Function to walk through ALL channels checking NAME and STATE */
static struct ast_channel *find_by_channel(struct ast_channel *chan, const char *channame)
{
    struct ast_channel *target;
    char *chkchan;
    struct pickup_by_name_args pickup_args;
 
    pickup_args.chan = chan;
 
    if (strchr(channame, '-')) {
        /*
         * Use the given channel name string as-is.  This allows a full channel
         * name with a typical sequence number to be used as well as still
         * allowing the odd partial channel name that has a '-' in it to still
         * work, i.e. Local/bob@en-phone.
         */
        pickup_args.len = strlen(channame);
        pickup_args.name = channame;
    } else {
        /*
         * Append a '-' for the comparison so we check the channel name less
         * a sequence number, i.e Find SIP/bob- and not SIP/bobby.
         */
        pickup_args.len = strlen(channame) + 1;
        chkchan = ast_alloca(pickup_args.len + 1);
        strcpy(chkchan, channame);/* Safe */
        strcat(chkchan, "-");
        pickup_args.name = chkchan;
    }
    target = ast_channel_callback(find_by_name, NULL, &pickup_args, 0);
    if (target) {
        return target;
    }
 
    /* Now try a search for uniqueid. */
    pickup_args.name = channame;
    pickup_args.len = 0;
    return ast_channel_callback(find_by_uniqueid, NULL, &pickup_args, 0);
}
 
/*! \brief Attempt to pick up named channel. */
static int pickup_by_channel(struct ast_channel *chan, const char *name)
{
    int res = -1;
    struct ast_channel *target;/*!< Potential pickup target */
 
    /* The found channel is already locked. */
    target = find_by_channel(chan, name);
    if (target) {
        res = ast_do_pickup(chan, target);
        ast_channel_unlock(target);
        target = ast_channel_unref(target);
    }
 
    return res;
}
 
/* Attempt to pick up specified extension with context */
static int pickup_by_exten(struct ast_channel *chan, const char *exten, const char *context)
{
    struct ast_channel *target = NULL;/*!< Potential pickup target */
    struct ast_channel_iterator *iter;
    int res = -1;
 
    if (!(iter = ast_channel_iterator_by_exten_new(exten, context))) {
        return -1;
    }
 
    while ((target = ast_channel_iterator_next(iter))) {
        ast_channel_lock(target);
        if ((chan != target) && ast_can_pickup(target)) {
            ast_log(LOG_NOTICE, "%s pickup by %s\n", ast_channel_name(target), ast_channel_name(chan));
            break;
        }
        ast_channel_unlock(target);
        target = ast_channel_unref(target);
    }
 
    ast_channel_iterator_destroy(iter);
 
    if (target) {
        res = ast_do_pickup(chan, target);
        ast_channel_unlock(target);
        target = ast_channel_unref(target);
    }
 
    return res;
}
 
static int find_by_mark(void *obj, void *arg, void *data, int flags)
{
    struct ast_channel *target = obj;/*!< Potential pickup target */
    struct ast_channel *chan = arg;
    const char *mark = data;
    const char *tmp;
 
    if (chan == target) {
        /* The channel attempting to pickup a call cannot pickup itself. */
        return 0;
    }
 
    ast_channel_lock(target);
    tmp = pbx_builtin_getvar_helper(target, PICKUPMARK);
    if (tmp && !strcasecmp(tmp, mark) && ast_can_pickup(target)) {
        /* Return with the channel still locked on purpose */
        return CMP_MATCH | CMP_STOP;
    }
    ast_channel_unlock(target);
 
    return 0;
}
 
/* Attempt to pick up specified mark */
static int pickup_by_mark(struct ast_channel *chan, const char *mark)
{
    struct ast_channel *target;/*!< Potential pickup target */
    int res = -1;
 
    /* The found channel is already locked. */
    target = ast_channel_callback(find_by_mark, chan, (char *) mark, 0);
    if (target) {
        res = ast_do_pickup(chan, target);
        ast_channel_unlock(target);
        target = ast_channel_unref(target);
    }
 
    return res;
}
 
static int pickup_by_group(struct ast_channel *chan)
{
    struct ast_channel *target;/*!< Potential pickup target */
    int res = -1;
 
    /* The found channel is already locked. */
    target = ast_pickup_find_by_group(chan);
    if (target) {
        ast_log(LOG_NOTICE, "pickup %s attempt by %s\n", ast_channel_name(target), ast_channel_name(chan));
        res = ast_do_pickup(chan, target);
        ast_channel_unlock(target);
        target = ast_channel_unref(target);
    }
 
    return res;
}
 
/* application entry point for Pickup() */
static int pickup_exec(struct ast_channel *chan, const char *data)
{
    char *parse;
    char *exten;
    char *context;
 
    if (ast_strlen_zero(data)) {
        return pickup_by_group(chan) ? 0 : -1;
    }
 
    /* Parse extension (and context if there) */
    parse = ast_strdupa(data);
    for (;;) {
        if (ast_strlen_zero(parse)) {
            break;
        }
        exten = strsep(&parse, "&");
        if (ast_strlen_zero(exten)) {
            continue;
        }
 
        context = strchr(exten, '@');
        if (context) {
            *context++ = '\0';
        }
        if (!ast_strlen_zero(context) && !strcasecmp(context, PICKUPMARK)) {
            if (!pickup_by_mark(chan, exten)) {
                /* Pickup successful.  Stop the dialplan this channel is a zombie. */
                return -1;
            }
        } else {
            if (ast_strlen_zero(context)) {
                context = (char *) ast_channel_context(chan);
            }
            if (!pickup_by_exten(chan, exten, context)) {
                /* Pickup successful.  Stop the dialplan this channel is a zombie. */
                return -1;
            }
        }
        ast_log(LOG_NOTICE, "No target channel found for %s@%s.\n", exten, context);
    }
 
    /* Pickup failed.  Keep going in the dialplan. */
    return 0;
}
 
/* Find channel for pick up specified by partial channel name */
static struct ast_channel *find_by_part(struct ast_channel *chan, const char *part)
{
    struct ast_channel *target;
    struct pickup_by_name_args pickup_args;
 
    pickup_args.chan = chan;
 
    /* Try a partial channel name search. */
    pickup_args.name = part;
    pickup_args.len = strlen(part);
    target = ast_channel_callback(find_by_name, NULL, &pickup_args, 0);
    if (target) {
        return target;
    }
 
    /* Now try a search for uniqueid. */
    pickup_args.name = part;
    pickup_args.len = 0;
    return ast_channel_callback(find_by_uniqueid, NULL, &pickup_args, 0);
}
 
/* Attempt to pick up specified by partial channel name */
static int pickup_by_part(struct ast_channel *chan, const char *part)
{
    struct ast_channel *target;/*!< Potential pickup target */
    int res = -1;
 
    /* The found channel is already locked. */
    target = find_by_part(chan, part);
    if (target) {
        res = ast_do_pickup(chan, target);
        ast_channel_unlock(target);
        target = ast_channel_unref(target);
    }
 
    return res;
}
 
enum OPT_PICKUPCHAN_FLAGS {
    OPT_PICKUPCHAN_PARTIAL =   (1 << 0),    /* Channel name is a partial name. */
};
 
AST_APP_OPTIONS(pickupchan_opts, BEGIN_OPTIONS
    AST_APP_OPTION('p', OPT_PICKUPCHAN_PARTIAL),
END_OPTIONS);
 
/* application entry point for PickupChan() */
static int pickupchan_exec(struct ast_channel *chan, const char *data)
{
    char *pickup = NULL;
    char *parse = ast_strdupa(data);
    AST_DECLARE_APP_ARGS(args,
        AST_APP_ARG(channel);
        AST_APP_ARG(options);
        AST_APP_ARG(other); /* Any remining unused arguments */
    );
    struct ast_flags opts;
 
    AST_STANDARD_APP_ARGS(args, parse);
 
    if (ast_strlen_zero(args.channel)) {
        ast_log(LOG_WARNING, "PickupChan requires an argument (channel)!\n");
        /* Pickup failed.  Keep going in the dialplan. */
        return 0;
    }
    if (ast_app_parse_options(pickupchan_opts, &opts, NULL, args.options)) {
        /*
         * General invalid option syntax.
         * Pickup failed.  Keep going in the dialplan.
         */
        return 0;
    }
 
    /* Parse channel */
    for (;;) {
        if (ast_strlen_zero(args.channel)) {
            break;
        }
        pickup = strsep(&args.channel, "&");
        if (ast_strlen_zero(pickup)) {
            continue;
        }
 
        if (ast_test_flag(&opts, OPT_PICKUPCHAN_PARTIAL)) {
            if (!pickup_by_part(chan, pickup)) {
                /* Pickup successful.  Stop the dialplan this channel is a zombie. */
                return -1;
            }
        } else if (!pickup_by_channel(chan, pickup)) {
            /* Pickup successful.  Stop the dialplan this channel is a zombie. */
            return -1;
        }
        ast_log(LOG_NOTICE, "No target channel found for %s.\n", pickup);
    }
 
    /* Pickup failed.  Keep going in the dialplan. */
    return 0;
}
 
static int unload_module(void)
{
    int res;
 
    res = ast_unregister_application(app);
    res |= ast_unregister_application(app2);
 
    return res;
}
 
static int load_module(void)
{
    int res;
 
    res = ast_register_application_xml(app, pickup_exec);
    res |= ast_register_application_xml(app2, pickupchan_exec);
 
    return res;
}
 
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Directed Call Pickup Application");