dial.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2007, Digium, Inc.
 *
 * Joshua Colp <jcolp@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 Dialing API
 *
 * \author Joshua Colp <jcolp@digium.com>
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <sys/time.h>
#include <signal.h>
 
#include "asterisk/channel.h"
#include "asterisk/utils.h"
#include "asterisk/lock.h"
#include "asterisk/linkedlists.h"
#include "asterisk/dial.h"
#include "asterisk/pbx.h"
#include "asterisk/musiconhold.h"
#include "asterisk/app.h"
#include "asterisk/causes.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/max_forwards.h"
 
/*! \brief Main dialing structure. Contains global options, channels being dialed, and more! */
struct ast_dial {
    int num;                                           /*!< Current number to give to next dialed channel */
    int timeout;                                       /*!< Maximum time allowed for dial attempts */
    int actual_timeout;                                /*!< Actual timeout based on all factors (ie: channels) */
    enum ast_dial_result state;                        /*!< Status of dial */
    void *options[AST_DIAL_OPTION_MAX];                /*!< Global options */
    ast_dial_state_callback state_callback;            /*!< Status callback */
    void *user_data;                                   /*!< Attached user data */
    AST_LIST_HEAD(, ast_dial_channel) channels; /*!< Channels being dialed */
    pthread_t thread;                                  /*!< Thread (if running in async) */
    ast_callid callid;                                 /*!< callid (if running in async) */
    ast_mutex_t lock;                                  /*! Lock to protect the thread information above */
};
 
/*! \brief Dialing channel structure. Contains per-channel dialing options, asterisk channel, and more! */
struct ast_dial_channel {
    int num;                /*!< Unique number for dialed channel */
    int timeout;                /*!< Maximum time allowed for attempt */
    char *tech;             /*!< Technology being dialed */
    char *device;               /*!< Device being dialed */
    void *options[AST_DIAL_OPTION_MAX]; /*!< Channel specific options */
    int cause;              /*!< Cause code in case of failure */
    unsigned int is_running_app:1;      /*!< Is this running an application? */
    char *assignedid1;              /*!< UniqueID to assign channel */
    char *assignedid2;              /*!< UniqueID to assign 2nd channel */
    struct ast_channel *owner;      /*!< Asterisk channel */
    AST_LIST_ENTRY(ast_dial_channel) list;  /*!< Linked list information */
};
 
/*! \brief Typedef for dial option enable */
typedef void *(*ast_dial_option_cb_enable)(void *data);
 
/*! \brief Typedef for dial option disable */
typedef int (*ast_dial_option_cb_disable)(void *data);
 
/*! \brief Structure for 'ANSWER_EXEC' option */
struct answer_exec_struct {
    char app[AST_MAX_APP]; /*!< Application name */
    char *args;            /*!< Application arguments */
};
 
/*! \brief Enable function for 'ANSWER_EXEC' option */
static void *answer_exec_enable(void *data)
{
    struct answer_exec_struct *answer_exec = NULL;
    char *app = ast_strdupa((char*)data), *args = NULL;
 
    /* Not giving any data to this option is bad, mmmk? */
    if (ast_strlen_zero(app))
        return NULL;
 
    /* Create new data structure */
    if (!(answer_exec = ast_calloc(1, sizeof(*answer_exec))))
        return NULL;
 
    /* Parse out application and arguments */
    if ((args = strchr(app, ','))) {
        *args++ = '\0';
        answer_exec->args = ast_strdup(args);
    }
 
    /* Copy application name */
    ast_copy_string(answer_exec->app, app, sizeof(answer_exec->app));
 
    return answer_exec;
}
 
/*! \brief Disable function for 'ANSWER_EXEC' option */
static int answer_exec_disable(void *data)
{
    struct answer_exec_struct *answer_exec = data;
 
    /* Make sure we have a value */
    if (!answer_exec)
        return -1;
 
    /* If arguments are present, free them too */
    if (answer_exec->args)
        ast_free(answer_exec->args);
 
    /* This is simple - just free the structure */
    ast_free(answer_exec);
 
    return 0;
}
 
static void *music_enable(void *data)
{
    return ast_strdup(data);
}
 
static int music_disable(void *data)
{
    if (!data)
        return -1;
 
    ast_free(data);
 
    return 0;
}
 
static void *predial_enable(void *data)
{
    return ast_strdup(data);
}
 
static int predial_disable(void *data)
{
    if (!data) {
        return -1;
    }
 
    ast_free(data);
 
    return 0;
}
 
/*! \brief Application execution function for 'ANSWER_EXEC' option */
static void answer_exec_run(struct ast_dial *dial, struct ast_dial_channel *dial_channel, char *app, char *args)
{
    struct ast_channel *chan = dial_channel->owner;
 
    /* Execute the application, if available */
    if (ast_pbx_exec_application(chan, app, args)) {
        /* If the application was not found, return immediately */
        return;
    }
 
    /* If another thread is not taking over hang up the channel */
    ast_mutex_lock(&dial->lock);
    if (dial->thread != AST_PTHREADT_STOP) {
        ast_hangup(chan);
        dial_channel->owner = NULL;
    }
    ast_mutex_unlock(&dial->lock);
 
    return;
}
 
struct ast_option_types {
    enum ast_dial_option option;
    ast_dial_option_cb_enable enable;
    ast_dial_option_cb_disable disable;
};
 
/*!
 * \brief Map options to respective handlers (enable/disable).
 *
 * \note This list MUST be perfectly kept in order with enum
 * ast_dial_option, or else madness will happen.
 */
static const struct ast_option_types option_types[] = {
    { AST_DIAL_OPTION_RINGING, NULL, NULL },                                  /*!< Always indicate ringing to caller */
    { AST_DIAL_OPTION_ANSWER_EXEC, answer_exec_enable, answer_exec_disable }, /*!< Execute application upon answer in async mode */
    { AST_DIAL_OPTION_MUSIC, music_enable, music_disable },                   /*!< Play music to the caller instead of ringing */
    { AST_DIAL_OPTION_DISABLE_CALL_FORWARDING, NULL, NULL },                  /*!< Disable call forwarding on channels */
    { AST_DIAL_OPTION_PREDIAL, predial_enable, predial_disable },             /*!< Execute a subroutine on the outbound channels prior to dialing */
    { AST_DIAL_OPTION_DIAL_REPLACES_SELF, NULL, NULL },                       /*!< The dial operation is a replacement for the requester */
    { AST_DIAL_OPTION_SELF_DESTROY, NULL, NULL},                              /*!< Destroy self at end of ast_dial_run */
    { AST_DIAL_OPTION_MAX, NULL, NULL },                                      /*!< Terminator of list */
};
 
/*! \brief Maximum number of channels we can watch at a time */
#define AST_MAX_WATCHERS 256
 
/*! \brief Macro for finding the option structure to use on a dialed channel */
#define FIND_RELATIVE_OPTION(dial, dial_channel, ast_dial_option) (dial_channel->options[ast_dial_option] ? dial_channel->options[ast_dial_option] : dial->options[ast_dial_option])
 
/*! \brief Macro that determines whether a channel is the caller or not */
#define IS_CALLER(chan, owner) (chan == owner ? 1 : 0)
 
/*! \brief New dialing structure
 * \note Create a dialing structure
 * \return Returns a calloc'd ast_dial structure, NULL on failure
 */
struct ast_dial *ast_dial_create(void)
{
    struct ast_dial *dial = NULL;
 
    /* Allocate new memory for structure */
    if (!(dial = ast_calloc(1, sizeof(*dial))))
        return NULL;
 
    /* Initialize list of channels */
    AST_LIST_HEAD_INIT(&dial->channels);
 
    /* Initialize thread to NULL */
    dial->thread = AST_PTHREADT_NULL;
 
    /* No timeout exists... yet */
    dial->timeout = -1;
    dial->actual_timeout = -1;
 
    /* Can't forget about the lock */
    ast_mutex_init(&dial->lock);
 
    return dial;
}
 
static int dial_append_common(struct ast_dial *dial, struct ast_dial_channel *channel,
        const char *tech, const char *device, const struct ast_assigned_ids *assignedids)
{
    /* Record technology and device for when we actually dial */
    channel->tech = ast_strdup(tech);
    channel->device = ast_strdup(device);
 
    /* Store the assigned id */
    if (assignedids && !ast_strlen_zero(assignedids->uniqueid)) {
        channel->assignedid1 = ast_strdup(assignedids->uniqueid);
 
        if (!ast_strlen_zero(assignedids->uniqueid2)) {
            channel->assignedid2 = ast_strdup(assignedids->uniqueid2);
        }
    }
 
    /* Grab reference number from dial structure */
    channel->num = ast_atomic_fetchadd_int(&dial->num, +1);
 
    /* No timeout exists... yet */
    channel->timeout = -1;
 
    /* Insert into channels list */
    AST_LIST_INSERT_TAIL(&dial->channels, channel, list);
 
    return channel->num;
 
}
 
/*! \brief Append a channel
 * \note Appends a channel to a dialing structure
 * \return Returns channel reference number on success, -1 on failure
 */
int ast_dial_append(struct ast_dial *dial, const char *tech, const char *device, const struct ast_assigned_ids *assignedids)
{
    struct ast_dial_channel *channel = NULL;
 
    /* Make sure we have required arguments */
    if (!dial || !tech || !device)
        return -1;
 
    /* Allocate new memory for dialed channel structure */
    if (!(channel = ast_calloc(1, sizeof(*channel))))
        return -1;
 
    return dial_append_common(dial, channel, tech, device, assignedids);
}
 
int ast_dial_append_channel(struct ast_dial *dial, struct ast_channel *chan)
{
    struct ast_dial_channel *channel;
    char *tech;
    char *device;
    char *dash;
 
    if (!dial || !chan) {
        return -1;
    }
 
    channel = ast_calloc(1, sizeof(*channel));
    if (!channel) {
        return -1;
    }
    channel->owner = chan;
 
    tech = ast_strdupa(ast_channel_name(chan));
 
    device = strchr(tech, '/');
    if (!device) {
        ast_free(channel);
        return -1;
    }
    *device++ = '\0';
 
    dash = strrchr(device, '-');
    if (dash) {
        *dash = '\0';
    }
 
    return dial_append_common(dial, channel, tech, device, NULL);
}
 
/*! \brief Helper function that requests all channels */
static int begin_dial_prerun(struct ast_dial_channel *channel, struct ast_channel *chan, struct ast_format_cap *cap, const char *predial_string)
{
    struct ast_format_cap *cap_all_audio = NULL;
    struct ast_format_cap *cap_request;
    struct ast_format_cap *requester_cap = NULL;
    struct ast_assigned_ids assignedids = {
        .uniqueid = channel->assignedid1,
        .uniqueid2 = channel->assignedid2,
    };
 
    if (chan) {
        int max_forwards;
 
        ast_channel_lock(chan);
        max_forwards = ast_max_forwards_get(chan);
        requester_cap = ao2_bump(ast_channel_nativeformats(chan));
        ast_channel_unlock(chan);
 
        if (max_forwards <= 0) {
            ast_log(LOG_WARNING, "Cannot dial from channel '%s'. Max forwards exceeded\n",
                    ast_channel_name(chan));
        }
    }
 
    if (!channel->owner) {
        if (cap && ast_format_cap_count(cap)) {
            cap_request = cap;
        } else if (requester_cap) {
            cap_request = requester_cap;
        } else {
            cap_all_audio = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
            ast_format_cap_append_by_type(cap_all_audio, AST_MEDIA_TYPE_AUDIO);
            cap_request = cap_all_audio;
        }
 
        /* If we fail to create our owner channel bail out */
        if (!(channel->owner = ast_request(channel->tech, cap_request, &assignedids, chan, channel->device, &channel->cause))) {
            ao2_cleanup(cap_all_audio);
            return -1;
        }
        cap_request = NULL;
        ao2_cleanup(requester_cap);
        ao2_cleanup(cap_all_audio);
    }
 
    if (chan) {
        ast_channel_lock_both(chan, channel->owner);
    } else {
        ast_channel_lock(channel->owner);
    }
 
    ast_channel_stage_snapshot(channel->owner);
 
    ast_channel_appl_set(channel->owner, "AppDial2");
    ast_channel_data_set(channel->owner, "(Outgoing Line)");
 
    memset(ast_channel_whentohangup(channel->owner), 0, sizeof(*ast_channel_whentohangup(channel->owner)));
 
    /* Inherit everything from he who spawned this dial */
    if (chan) {
        ast_channel_inherit_variables(chan, channel->owner);
        ast_channel_datastore_inherit(chan, channel->owner);
        ast_max_forwards_decrement(channel->owner);
 
        /* Copy over callerid information */
        ast_party_redirecting_copy(ast_channel_redirecting(channel->owner), ast_channel_redirecting(chan));
 
        ast_channel_dialed(channel->owner)->transit_network_select = ast_channel_dialed(chan)->transit_network_select;
 
        ast_connected_line_copy_from_caller(ast_channel_connected(channel->owner), ast_channel_caller(chan));
 
        ast_channel_language_set(channel->owner, ast_channel_language(chan));
        if (channel->options[AST_DIAL_OPTION_DIAL_REPLACES_SELF]) {
            ast_channel_req_accountcodes(channel->owner, chan, AST_CHANNEL_REQUESTOR_REPLACEMENT);
        } else {
            ast_channel_req_accountcodes(channel->owner, chan, AST_CHANNEL_REQUESTOR_BRIDGE_PEER);
        }
        if (ast_strlen_zero(ast_channel_musicclass(channel->owner)))
            ast_channel_musicclass_set(channel->owner, ast_channel_musicclass(chan));
 
        ast_channel_adsicpe_set(channel->owner, ast_channel_adsicpe(chan));
        ast_channel_transfercapability_set(channel->owner, ast_channel_transfercapability(chan));
        ast_channel_unlock(chan);
    }
 
    ast_channel_stage_snapshot_done(channel->owner);
    ast_channel_unlock(channel->owner);
 
    if (!ast_strlen_zero(predial_string)) {
        if (chan) {
            ast_autoservice_start(chan);
        }
        ast_pre_call(channel->owner, predial_string);
        if (chan) {
            ast_autoservice_stop(chan);
        }
    }
 
    return 0;
}
 
int ast_dial_prerun(struct ast_dial *dial, struct ast_channel *chan, struct ast_format_cap *cap)
{
    struct ast_dial_channel *channel;
    int res = -1;
    char *predial_string = dial->options[AST_DIAL_OPTION_PREDIAL];
 
    AST_LIST_LOCK(&dial->channels);
    AST_LIST_TRAVERSE(&dial->channels, channel, list) {
        if ((res = begin_dial_prerun(channel, chan, cap, predial_string))) {
            break;
        }
    }
    AST_LIST_UNLOCK(&dial->channels);
 
    return res;
}
 
/*! \brief Helper function that does the beginning dialing per-appended channel */
static int begin_dial_channel(struct ast_dial_channel *channel, struct ast_channel *chan, int async, const char *predial_string, struct ast_channel *forwarder_chan)
{
    int res = 1;
    char forwarder[AST_CHANNEL_NAME];
 
    /* If no owner channel exists yet execute pre-run */
    if (!channel->owner && begin_dial_prerun(channel, chan, NULL, predial_string)) {
        return 0;
    }
 
    if (forwarder_chan) {
        ast_copy_string(forwarder, ast_channel_name(forwarder_chan), sizeof(forwarder));
        ast_channel_lock(channel->owner);
        pbx_builtin_setvar_helper(channel->owner, "FORWARDERNAME", forwarder);
        ast_channel_unlock(channel->owner);
    }
 
    /* Attempt to actually call this device */
    if ((res = ast_call(channel->owner, channel->device, 0))) {
        res = 0;
        ast_hangup(channel->owner);
        channel->owner = NULL;
    } else {
        ast_channel_publish_dial(async ? NULL : chan, channel->owner, channel->device, NULL);
        res = 1;
        ast_verb(3, "Called %s\n", channel->device);
    }
 
    return res;
}
 
/*! \brief Helper function that does the beginning dialing per dial structure */
static int begin_dial(struct ast_dial *dial, struct ast_channel *chan, int async)
{
    struct ast_dial_channel *channel = NULL;
    int success = 0;
    char *predial_string = dial->options[AST_DIAL_OPTION_PREDIAL];
 
    /* Iterate through channel list, requesting and calling each one */
    AST_LIST_LOCK(&dial->channels);
    AST_LIST_TRAVERSE(&dial->channels, channel, list) {
        success += begin_dial_channel(channel, chan, async, predial_string, NULL);
    }
    AST_LIST_UNLOCK(&dial->channels);
 
    /* If number of failures matches the number of channels, then this truly failed */
    return success;
}
 
/*! \brief Helper function to handle channels that have been call forwarded */
static int handle_call_forward(struct ast_dial *dial, struct ast_dial_channel *channel, struct ast_channel *chan)
{
    struct ast_channel *original = channel->owner;
    char *tmp = ast_strdupa(ast_channel_call_forward(channel->owner));
    char *tech = "Local", *device = tmp, *stuff;
    char *predial_string = dial->options[AST_DIAL_OPTION_PREDIAL];
 
    /* If call forwarding is disabled just drop the original channel and don't attempt to dial the new one */
    if (FIND_RELATIVE_OPTION(dial, channel, AST_DIAL_OPTION_DISABLE_CALL_FORWARDING)) {
        ast_hangup(original);
        channel->owner = NULL;
        return 0;
    }
 
    /* Figure out the new destination */
    if ((stuff = strchr(tmp, '/'))) {
        *stuff++ = '\0';
        tech = tmp;
        device = stuff;
    } else {
        const char *forward_context;
        char destination[AST_MAX_CONTEXT + AST_MAX_EXTENSION + 1];
 
        ast_channel_lock(original);
        forward_context = pbx_builtin_getvar_helper(original, "FORWARD_CONTEXT");
        snprintf(destination, sizeof(destination), "%s@%s", tmp, S_OR(forward_context, ast_channel_context(original)));
        ast_channel_unlock(original);
        device = ast_strdupa(destination);
    }
 
    /* Drop old destination information */
    ast_free(channel->tech);
    ast_free(channel->device);
    ast_free(channel->assignedid1);
    channel->assignedid1 = NULL;
    ast_free(channel->assignedid2);
    channel->assignedid2 = NULL;
 
    /* Update the dial channel with the new destination information */
    channel->tech = ast_strdup(tech);
    channel->device = ast_strdup(device);
    AST_LIST_UNLOCK(&dial->channels);
 
    /* Drop the original channel */
    channel->owner = NULL;
 
    /* Finally give it a go... send it out into the world */
    begin_dial_channel(channel, chan, chan ? 0 : 1, predial_string, original);
 
    ast_channel_publish_dial_forward(chan, original, channel->owner, NULL, "CANCEL",
        ast_channel_call_forward(original));
 
    ast_hangup(original);
 
    return 0;
}
 
/*! \brief Helper function that finds the dialed channel based on owner */
static struct ast_dial_channel *find_relative_dial_channel(struct ast_dial *dial, struct ast_channel *owner)
{
    struct ast_dial_channel *channel = NULL;
 
    AST_LIST_LOCK(&dial->channels);
    AST_LIST_TRAVERSE(&dial->channels, channel, list) {
        if (channel->owner == owner)
            break;
    }
    AST_LIST_UNLOCK(&dial->channels);
 
    return channel;
}
 
static void set_state(struct ast_dial *dial, enum ast_dial_result state)
{
    dial->state = state;
 
    if (dial->state_callback)
        dial->state_callback(dial);
}
 
/*! \brief Helper function that handles frames */
static void handle_frame(struct ast_dial *dial, struct ast_dial_channel *channel, struct ast_frame *fr, struct ast_channel *chan)
{
    if (fr->frametype == AST_FRAME_CONTROL) {
        switch (fr->subclass.integer) {
        case AST_CONTROL_ANSWER:
            if (chan) {
                ast_verb(3, "%s answered %s\n", ast_channel_name(channel->owner), ast_channel_name(chan));
            } else {
                ast_verb(3, "%s answered\n", ast_channel_name(channel->owner));
            }
            AST_LIST_LOCK(&dial->channels);
            AST_LIST_REMOVE(&dial->channels, channel, list);
            AST_LIST_INSERT_HEAD(&dial->channels, channel, list);
            AST_LIST_UNLOCK(&dial->channels);
            ast_channel_publish_dial(chan, channel->owner, channel->device, "ANSWER");
            set_state(dial, AST_DIAL_RESULT_ANSWERED);
            break;
        case AST_CONTROL_BUSY:
            ast_verb(3, "%s is busy\n", ast_channel_name(channel->owner));
            ast_channel_publish_dial(chan, channel->owner, channel->device, "BUSY");
            ast_hangup(channel->owner);
            channel->cause = AST_CAUSE_USER_BUSY;
            channel->owner = NULL;
            break;
        case AST_CONTROL_CONGESTION:
            ast_verb(3, "%s is circuit-busy\n", ast_channel_name(channel->owner));
            ast_channel_publish_dial(chan, channel->owner, channel->device, "CONGESTION");
            ast_hangup(channel->owner);
            channel->cause = AST_CAUSE_NORMAL_CIRCUIT_CONGESTION;
            channel->owner = NULL;
            break;
        case AST_CONTROL_INCOMPLETE:
            ast_verb(3, "%s dialed Incomplete extension %s\n", ast_channel_name(channel->owner), ast_channel_exten(channel->owner));
            if (chan) {
                ast_indicate(chan, AST_CONTROL_INCOMPLETE);
            } else {
                ast_hangup(channel->owner);
                channel->cause = AST_CAUSE_UNALLOCATED;
                channel->owner = NULL;
            }
            break;
        case AST_CONTROL_RINGING:
            ast_verb(3, "%s is ringing\n", ast_channel_name(channel->owner));
            ast_channel_publish_dial(chan, channel->owner, channel->device, "RINGING");
            if (chan && !dial->options[AST_DIAL_OPTION_MUSIC])
                ast_indicate(chan, AST_CONTROL_RINGING);
            set_state(dial, AST_DIAL_RESULT_RINGING);
            break;
        case AST_CONTROL_PROGRESS:
            ast_channel_publish_dial(chan, channel->owner, channel->device, "PROGRESS");
            if (chan) {
                ast_verb(3, "%s is making progress, passing it to %s\n", ast_channel_name(channel->owner), ast_channel_name(chan));
                ast_indicate(chan, AST_CONTROL_PROGRESS);
            } else {
                ast_verb(3, "%s is making progress\n", ast_channel_name(channel->owner));
            }
            set_state(dial, AST_DIAL_RESULT_PROGRESS);
            break;
        case AST_CONTROL_VIDUPDATE:
            if (!chan) {
                break;
            }
            ast_verb(3, "%s requested a video update, passing it to %s\n", ast_channel_name(channel->owner), ast_channel_name(chan));
            ast_indicate(chan, AST_CONTROL_VIDUPDATE);
            break;
        case AST_CONTROL_SRCUPDATE:
            if (!chan) {
                break;
            }
            ast_verb(3, "%s requested a source update, passing it to %s\n", ast_channel_name(channel->owner), ast_channel_name(chan));
            ast_indicate(chan, AST_CONTROL_SRCUPDATE);
            break;
        case AST_CONTROL_CONNECTED_LINE:
            if (!chan) {
                break;
            }
            ast_verb(3, "%s connected line has changed, passing it to %s\n", ast_channel_name(channel->owner), ast_channel_name(chan));
            if (ast_channel_connected_line_sub(channel->owner, chan, fr, 1)) {
                ast_indicate_data(chan, AST_CONTROL_CONNECTED_LINE, fr->data.ptr, fr->datalen);
            }
            break;
        case AST_CONTROL_REDIRECTING:
            if (!chan) {
                break;
            }
            ast_verb(3, "%s redirecting info has changed, passing it to %s\n", ast_channel_name(channel->owner), ast_channel_name(chan));
            if (ast_channel_redirecting_sub(channel->owner, chan, fr, 1)) {
                ast_indicate_data(chan, AST_CONTROL_REDIRECTING, fr->data.ptr, fr->datalen);
            }
            break;
        case AST_CONTROL_PROCEEDING:
            ast_channel_publish_dial(chan, channel->owner, channel->device, "PROCEEDING");
            if (chan) {
                ast_verb(3, "%s is proceeding, passing it to %s\n", ast_channel_name(channel->owner), ast_channel_name(chan));
                ast_indicate(chan, AST_CONTROL_PROCEEDING);
            } else {
                ast_verb(3, "%s is proceeding\n", ast_channel_name(channel->owner));
            }
            set_state(dial, AST_DIAL_RESULT_PROCEEDING);
            break;
        case AST_CONTROL_HOLD:
            if (!chan) {
                break;
            }
            ast_verb(3, "Call on %s placed on hold\n", ast_channel_name(chan));
            ast_indicate_data(chan, AST_CONTROL_HOLD, fr->data.ptr, fr->datalen);
            break;
        case AST_CONTROL_UNHOLD:
            if (!chan) {
                break;
            }
            ast_verb(3, "Call on %s left from hold\n", ast_channel_name(chan));
            ast_indicate(chan, AST_CONTROL_UNHOLD);
            break;
        case AST_CONTROL_OFFHOOK:
        case AST_CONTROL_FLASH:
            break;
        case AST_CONTROL_PVT_CAUSE_CODE:
            if (chan) {
                ast_indicate_data(chan, AST_CONTROL_PVT_CAUSE_CODE, fr->data.ptr, fr->datalen);
            }
            break;
        case -1:
            if (chan) {
                /* Prod the channel */
                ast_indicate(chan, -1);
            }
            break;
        default:
            break;
        }
    }
}
 
/*! \brief Helper function to handle when a timeout occurs on dialing attempt */
static int handle_timeout_trip(struct ast_dial *dial, struct timeval start)
{
    struct ast_dial_channel *channel = NULL;
    int diff = ast_tvdiff_ms(ast_tvnow(), start), lowest_timeout = -1, new_timeout = -1;
 
    /* If there is no difference yet return the dial timeout so we can go again, we were likely interrupted */
    if (!diff) {
        return dial->timeout;
    }
 
    /* If the global dial timeout tripped switch the state to timeout so our channel loop will drop every channel */
    if (diff >= dial->timeout) {
        set_state(dial, AST_DIAL_RESULT_TIMEOUT);
        new_timeout = 0;
    }
 
    /* Go through dropping out channels that have met their timeout */
    AST_LIST_TRAVERSE(&dial->channels, channel, list) {
        if (dial->state == AST_DIAL_RESULT_TIMEOUT || diff >= channel->timeout) {
            ast_hangup(channel->owner);
            channel->cause = AST_CAUSE_NO_ANSWER;
            channel->owner = NULL;
        } else if ((lowest_timeout == -1) || (lowest_timeout > channel->timeout)) {
            lowest_timeout = channel->timeout;
        }
    }
 
    /* Calculate the new timeout using the lowest timeout found */
    if (lowest_timeout >= 0)
        new_timeout = lowest_timeout - diff;
 
    return new_timeout;
}
 
const char *ast_hangup_cause_to_dial_status(int hangup_cause)
{
    switch(hangup_cause) {
    case AST_CAUSE_BUSY:
        return "BUSY";
    case AST_CAUSE_CONGESTION:
        return "CONGESTION";
    case AST_CAUSE_NO_ROUTE_DESTINATION:
    case AST_CAUSE_UNREGISTERED:
        return "CHANUNAVAIL";
    case AST_CAUSE_NO_ANSWER:
    default:
        return "NOANSWER";
    }
}
 
/*! \brief Helper function that basically keeps tabs on dialing attempts */
static enum ast_dial_result monitor_dial(struct ast_dial *dial, struct ast_channel *chan)
{
    int timeout = -1;
    struct ast_channel *cs[AST_MAX_WATCHERS], *who = NULL;
    struct ast_dial_channel *channel = NULL;
    struct answer_exec_struct *answer_exec = NULL;
    struct timeval start;
 
    set_state(dial, AST_DIAL_RESULT_TRYING);
 
    /* If the "always indicate ringing" option is set, change state to ringing and indicate to the owner if present */
    if (dial->options[AST_DIAL_OPTION_RINGING]) {
        set_state(dial, AST_DIAL_RESULT_RINGING);
        if (chan)
            ast_indicate(chan, AST_CONTROL_RINGING);
    } else if (chan && dial->options[AST_DIAL_OPTION_MUSIC] &&
        !ast_strlen_zero(dial->options[AST_DIAL_OPTION_MUSIC])) {
        char *original_moh = ast_strdupa(ast_channel_musicclass(chan));
        ast_indicate(chan, -1);
        ast_channel_musicclass_set(chan, dial->options[AST_DIAL_OPTION_MUSIC]);
        ast_moh_start(chan, dial->options[AST_DIAL_OPTION_MUSIC], NULL);
        ast_channel_musicclass_set(chan, original_moh);
    }
 
    /* Record start time for timeout purposes */
    start = ast_tvnow();
 
    /* We actually figured out the maximum timeout we can do as they were added, so we can directly access the info */
    timeout = dial->actual_timeout;
 
    /* Go into an infinite loop while we are trying */
    while ((dial->state != AST_DIAL_RESULT_UNANSWERED) && (dial->state != AST_DIAL_RESULT_ANSWERED) && (dial->state != AST_DIAL_RESULT_HANGUP) && (dial->state != AST_DIAL_RESULT_TIMEOUT)) {
        int pos = 0, count = 0;
        struct ast_frame *fr = NULL;
 
        /* Set up channel structure array */
        pos = count = 0;
        if (chan)
            cs[pos++] = chan;
 
        /* Add channels we are attempting to dial */
        AST_LIST_LOCK(&dial->channels);
        AST_LIST_TRAVERSE(&dial->channels, channel, list) {
            if (channel->owner) {
                cs[pos++] = channel->owner;
                count++;
            }
        }
        AST_LIST_UNLOCK(&dial->channels);
 
        /* If we have no outbound channels in progress, switch state to unanswered and stop */
        if (!count) {
            set_state(dial, AST_DIAL_RESULT_UNANSWERED);
            break;
        }
 
        /* Just to be safe... */
        if (dial->thread == AST_PTHREADT_STOP)
            break;
 
        /* Wait for frames from channels */
        who = ast_waitfor_n(cs, pos, &timeout);
 
        /* Check to see if our thread is being canceled */
        if (dial->thread == AST_PTHREADT_STOP)
            break;
 
        /* If the timeout no longer exists OR if we got no channel it basically means the timeout was tripped, so handle it */
        if (!timeout || !who) {
            timeout = handle_timeout_trip(dial, start);
            continue;
        }
 
        /* Find relative dial channel */
        if (!chan || !IS_CALLER(chan, who))
            channel = find_relative_dial_channel(dial, who);
 
        /* See if this channel has been forwarded elsewhere */
        if (!ast_strlen_zero(ast_channel_call_forward(who))) {
            handle_call_forward(dial, channel, chan);
            continue;
        }
 
        /* Attempt to read in a frame */
        if (!(fr = ast_read(who))) {
            /* If this is the caller then we switch state to hangup and stop */
            if (chan && IS_CALLER(chan, who)) {
                set_state(dial, AST_DIAL_RESULT_HANGUP);
                break;
            }
            ast_channel_publish_dial(chan, who, channel->device, ast_hangup_cause_to_dial_status(ast_channel_hangupcause(who)));
            ast_hangup(who);
            channel->owner = NULL;
            continue;
        }
 
        /* Process the frame */
        handle_frame(dial, channel, fr, chan);
 
        /* Free the received frame and start all over */
        ast_frfree(fr);
    }
 
    /* Do post-processing from loop */
    if (dial->state == AST_DIAL_RESULT_ANSWERED) {
        /* Hangup everything except that which answered */
        AST_LIST_LOCK(&dial->channels);
        AST_LIST_TRAVERSE(&dial->channels, channel, list) {
            if (!channel->owner || channel->owner == who)
                continue;
            ast_channel_publish_dial(chan, channel->owner, channel->device, "CANCEL");
            ast_hangup(channel->owner);
            channel->cause = AST_CAUSE_ANSWERED_ELSEWHERE;
            channel->owner = NULL;
        }
        AST_LIST_UNLOCK(&dial->channels);
        /* If ANSWER_EXEC is enabled as an option, execute application on answered channel */
        if ((channel = find_relative_dial_channel(dial, who)) && (answer_exec = FIND_RELATIVE_OPTION(dial, channel, AST_DIAL_OPTION_ANSWER_EXEC))) {
            channel->is_running_app = 1;
            answer_exec_run(dial, channel, answer_exec->app, answer_exec->args);
            channel->is_running_app = 0;
        }
 
        if (chan && dial->options[AST_DIAL_OPTION_MUSIC] &&
            !ast_strlen_zero(dial->options[AST_DIAL_OPTION_MUSIC])) {
            ast_moh_stop(chan);
        }
    } else if (dial->state == AST_DIAL_RESULT_HANGUP) {
        /* Hangup everything */
        AST_LIST_LOCK(&dial->channels);
        AST_LIST_TRAVERSE(&dial->channels, channel, list) {
            if (!channel->owner)
                continue;
            ast_channel_publish_dial(chan, channel->owner, channel->device, "CANCEL");
            ast_hangup(channel->owner);
            channel->cause = AST_CAUSE_NORMAL_CLEARING;
            channel->owner = NULL;
        }
        AST_LIST_UNLOCK(&dial->channels);
    }
 
    if (dial->options[AST_DIAL_OPTION_SELF_DESTROY]) {
        enum ast_dial_result state = dial->state;
 
        ast_dial_destroy(dial);
        return state;
    }
 
    return dial->state;
}
 
/*! \brief Dial async thread function */
static void *async_dial(void *data)
{
    struct ast_dial *dial = data;
    if (dial->callid) {
        ast_callid_threadassoc_add(dial->callid);
    }
 
    /* This is really really simple... we basically pass monitor_dial a NULL owner and it changes it's behavior */
    monitor_dial(dial, NULL);
 
    return NULL;
}
 
/*! \brief Execute dialing synchronously or asynchronously
 * \note Dials channels in a dial structure.
 * \return Returns dial result code. (TRYING/INVALID/FAILED/ANSWERED/TIMEOUT/UNANSWERED).
 */
enum ast_dial_result ast_dial_run(struct ast_dial *dial, struct ast_channel *chan, int async)
{
    enum ast_dial_result res = AST_DIAL_RESULT_TRYING;
 
    /* Ensure required arguments are passed */
    if (!dial) {
        ast_debug(1, "invalid #1\n");
        return AST_DIAL_RESULT_INVALID;
    }
 
    /* If there are no channels to dial we can't very well try to dial them */
    if (AST_LIST_EMPTY(&dial->channels)) {
        ast_debug(1, "invalid #2\n");
        return AST_DIAL_RESULT_INVALID;
    }
 
    /* Dial each requested channel */
    if (!begin_dial(dial, chan, async))
        return AST_DIAL_RESULT_FAILED;
 
    /* If we are running async spawn a thread and send it away... otherwise block here */
    if (async) {
        /* reference be released at dial destruction if it isn't NULL */
        dial->callid = ast_read_threadstorage_callid();
        dial->state = AST_DIAL_RESULT_TRYING;
        /* Try to create a thread */
        if (ast_pthread_create(&dial->thread, NULL, async_dial, dial)) {
            /* Failed to create the thread - hangup all dialed channels and return failed */
            ast_dial_hangup(dial);
            res = AST_DIAL_RESULT_FAILED;
        }
    } else {
        res = monitor_dial(dial, chan);
    }
 
    return res;
}
 
/*! \brief Return channel that answered
 * \note Returns the Asterisk channel that answered
 * \param dial Dialing structure
 */
struct ast_channel *ast_dial_answered(struct ast_dial *dial)
{
    if (!dial)
        return NULL;
 
    return ((dial->state == AST_DIAL_RESULT_ANSWERED) ? AST_LIST_FIRST(&dial->channels)->owner : NULL);
}
 
/*! \brief Steal the channel that answered
 * \note Returns the Asterisk channel that answered and removes it from the dialing structure
 * \param dial Dialing structure
 */
struct ast_channel *ast_dial_answered_steal(struct ast_dial *dial)
{
    struct ast_channel *chan = NULL;
 
    if (!dial)
        return NULL;
 
    if (dial->state == AST_DIAL_RESULT_ANSWERED) {
        chan = AST_LIST_FIRST(&dial->channels)->owner;
        AST_LIST_FIRST(&dial->channels)->owner = NULL;
    }
 
    return chan;
}
 
/*! \brief Return state of dial
 * \note Returns the state of the dial attempt
 * \param dial Dialing structure
 */
enum ast_dial_result ast_dial_state(struct ast_dial *dial)
{
    return dial->state;
}
 
/*! \brief Cancel async thread
 * \note Cancel a running async thread
 * \param dial Dialing structure
 */
enum ast_dial_result ast_dial_join(struct ast_dial *dial)
{
    pthread_t thread;
 
    /* If the dial structure is not running in async, return failed */
    if (dial->thread == AST_PTHREADT_NULL)
        return AST_DIAL_RESULT_FAILED;
 
    /* Record thread */
    thread = dial->thread;
 
    /* Boom, commence locking */
    ast_mutex_lock(&dial->lock);
 
    /* Stop the thread */
    dial->thread = AST_PTHREADT_STOP;
 
    /* If the answered channel is running an application we have to soft hangup it, can't just poke the thread */
    AST_LIST_LOCK(&dial->channels);
    if (AST_LIST_FIRST(&dial->channels)->is_running_app) {
        struct ast_channel *chan = AST_LIST_FIRST(&dial->channels)->owner;
        if (chan) {
            ast_channel_lock(chan);
            ast_softhangup(chan, AST_SOFTHANGUP_EXPLICIT);
            ast_channel_unlock(chan);
        }
    } else {
        struct ast_dial_channel *channel = NULL;
 
        /* Now we signal it with SIGURG so it will break out of it's waitfor */
        pthread_kill(thread, SIGURG);
 
        /* pthread_kill may not be enough, if outgoing channel has already got an answer (no more in waitfor) but is not yet running an application. Force soft hangup. */
        AST_LIST_TRAVERSE(&dial->channels, channel, list) {
            if (channel->owner) {
                ast_softhangup(channel->owner, AST_SOFTHANGUP_EXPLICIT);
            }
        }
    }
    AST_LIST_UNLOCK(&dial->channels);
 
    /* Yay done with it */
    ast_mutex_unlock(&dial->lock);
 
    /* Finally wait for the thread to exit */
    pthread_join(thread, NULL);
 
    /* Yay thread is all gone */
    dial->thread = AST_PTHREADT_NULL;
 
    return dial->state;
}
 
/*! \brief Hangup channels
 * \note Hangup all active channels
 * \param dial Dialing structure
 */
void ast_dial_hangup(struct ast_dial *dial)
{
    struct ast_dial_channel *channel = NULL;
 
    if (!dial)
        return;
 
    AST_LIST_LOCK(&dial->channels);
    AST_LIST_TRAVERSE(&dial->channels, channel, list) {
        ast_hangup(channel->owner);
        channel->owner = NULL;
    }
    AST_LIST_UNLOCK(&dial->channels);
 
    return;
}
 
int ast_dial_destroy(struct ast_dial *dial)
{
    int i = 0;
    struct ast_dial_channel *channel = NULL;
 
    if (!dial)
        return -1;
 
    /* Hangup and deallocate all the dialed channels */
    AST_LIST_LOCK(&dial->channels);
    AST_LIST_TRAVERSE_SAFE_BEGIN(&dial->channels, channel, list) {
        /* Disable any enabled options */
        for (i = 0; i < AST_DIAL_OPTION_MAX; i++) {
            if (!channel->options[i])
                continue;
            if (option_types[i].disable)
                option_types[i].disable(channel->options[i]);
            channel->options[i] = NULL;
        }
 
        /* Hang up channel if need be */
        ast_hangup(channel->owner);
        channel->owner = NULL;
 
        /* Free structure */
        ast_free(channel->tech);
        ast_free(channel->device);
        ast_free(channel->assignedid1);
        ast_free(channel->assignedid2);
 
        AST_LIST_REMOVE_CURRENT(list);
        ast_free(channel);
    }
    AST_LIST_TRAVERSE_SAFE_END;
    AST_LIST_UNLOCK(&dial->channels);
 
    /* Disable any enabled options globally */
    for (i = 0; i < AST_DIAL_OPTION_MAX; i++) {
        if (!dial->options[i])
            continue;
        if (option_types[i].disable)
            option_types[i].disable(dial->options[i]);
        dial->options[i] = NULL;
    }
 
    /* Lock be gone! */
    ast_mutex_destroy(&dial->lock);
 
    /* Free structure */
    ast_free(dial);
 
    return 0;
}
 
int ast_dial_option_global_enable(struct ast_dial *dial, enum ast_dial_option option, void *data)
{
    /* If the option is already enabled, return failure */
    if (dial->options[option])
        return -1;
 
    /* Execute enable callback if it exists, if not simply make sure the value is set */
    if (option_types[option].enable)
        dial->options[option] = option_types[option].enable(data);
    else
        dial->options[option] = (void*)1;
 
    return 0;
}
 
/*! \brief Helper function for finding a channel in a dial structure based on number
 */
static struct ast_dial_channel *find_dial_channel(struct ast_dial *dial, int num)
{
    struct ast_dial_channel *channel = AST_LIST_LAST(&dial->channels);
 
    /* We can try to predict programmer behavior, the last channel they added is probably the one they wanted to modify */
    if (channel->num == num)
        return channel;
 
    /* Hrm not at the end... looking through the list it is! */
    AST_LIST_LOCK(&dial->channels);
    AST_LIST_TRAVERSE(&dial->channels, channel, list) {
        if (channel->num == num)
            break;
    }
    AST_LIST_UNLOCK(&dial->channels);
 
    return channel;
}
 
int ast_dial_option_enable(struct ast_dial *dial, int num, enum ast_dial_option option, void *data)
{
    struct ast_dial_channel *channel = NULL;
 
    /* Ensure we have required arguments */
    if (!dial || AST_LIST_EMPTY(&dial->channels))
        return -1;
 
    if (!(channel = find_dial_channel(dial, num)))
        return -1;
 
    /* If the option is already enabled, return failure */
    if (channel->options[option])
        return -1;
 
    /* Execute enable callback if it exists, if not simply make sure the value is set */
    if (option_types[option].enable)
        channel->options[option] = option_types[option].enable(data);
    else
        channel->options[option] = (void*)1;
 
    return 0;
}
 
int ast_dial_option_global_disable(struct ast_dial *dial, enum ast_dial_option option)
{
    /* If the option is not enabled, return failure */
    if (!dial->options[option]) {
        return -1;
    }
 
    /* Execute callback of option to disable if it exists */
    if (option_types[option].disable)
        option_types[option].disable(dial->options[option]);
 
    /* Finally disable option on the structure */
    dial->options[option] = NULL;
 
    return 0;
}
 
int ast_dial_option_disable(struct ast_dial *dial, int num, enum ast_dial_option option)
{
    struct ast_dial_channel *channel = NULL;
 
    /* Ensure we have required arguments */
    if (!dial || AST_LIST_EMPTY(&dial->channels))
        return -1;
 
    if (!(channel = find_dial_channel(dial, num)))
        return -1;
 
    /* If the option is not enabled, return failure */
    if (!channel->options[option])
        return -1;
 
    /* Execute callback of option to disable it if it exists */
    if (option_types[option].disable)
        option_types[option].disable(channel->options[option]);
 
    /* Finally disable the option on the structure */
    channel->options[option] = NULL;
 
    return 0;
}
 
int ast_dial_reason(struct ast_dial *dial, int num)
{
    struct ast_dial_channel *channel;
 
    if (!dial || AST_LIST_EMPTY(&dial->channels) || !(channel = find_dial_channel(dial, num))) {
        return -1;
    }
 
    return channel->cause;
}
 
struct ast_channel *ast_dial_get_channel(struct ast_dial *dial, int num)
{
    struct ast_dial_channel *channel;
 
    if (!dial || AST_LIST_EMPTY(&dial->channels) || !(channel = find_dial_channel(dial, num))) {
        return NULL;
    }
 
    return channel->owner;
}
 
void ast_dial_set_state_callback(struct ast_dial *dial, ast_dial_state_callback callback)
{
    dial->state_callback = callback;
}
 
void ast_dial_set_user_data(struct ast_dial *dial, void *user_data)
{
    dial->user_data = user_data;
}
 
void *ast_dial_get_user_data(struct ast_dial *dial)
{
    return dial->user_data;
}
 
void ast_dial_set_global_timeout(struct ast_dial *dial, int timeout)
{
    dial->timeout = timeout;
 
    if (dial->timeout > 0 && (dial->actual_timeout > dial->timeout || dial->actual_timeout == -1))
        dial->actual_timeout = dial->timeout;
 
    return;
}
 
void ast_dial_set_timeout(struct ast_dial *dial, int num, int timeout)
{
    struct ast_dial_channel *channel = NULL;
 
    if (!(channel = find_dial_channel(dial, num)))
        return;
 
    channel->timeout = timeout;
 
    if (channel->timeout > 0 && (dial->actual_timeout > channel->timeout || dial->actual_timeout == -1))
        dial->actual_timeout = channel->timeout;
 
    return;
}