bridge_channel.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2007 - 2009, 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 Bridging Channel API
 *
 * \author Joshua Colp <jcolp@digium.com>
 * \author Richard Mudgett <rmudgett@digium.com>
 * \author Matt Jordan <mjordan@digium.com>
 *
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include <signal.h>
 
#include "asterisk/heap.h"
#include "asterisk/alertpipe.h"
#include "asterisk/astobj2.h"
#include "asterisk/stringfields.h"
#include "asterisk/app.h"
#include "asterisk/pbx.h"
#include "asterisk/channel.h"
#include "asterisk/timing.h"
#include "asterisk/bridge.h"
#include "asterisk/bridge_channel.h"
#include "asterisk/bridge_after.h"
#include "asterisk/bridge_channel_internal.h"
#include "asterisk/bridge_internal.h"
#include "asterisk/stasis_bridges.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/musiconhold.h"
#include "asterisk/features_config.h"
#include "asterisk/parking.h"
#include "asterisk/causes.h"
#include "asterisk/test.h"
#include "asterisk/sem.h"
#include "asterisk/stream.h"
#include "asterisk/message.h"
#include "asterisk/core_local.h"
 
/*!
 * \brief Used to queue an action frame onto a bridge channel and write an action frame into a bridge.
 * \since 12.0.0
 *
 * \param bridge_channel Which channel work with.
 * \param action Type of bridge action frame.
 * \param data Frame payload data to pass.
 * \param datalen Frame payload data length to pass.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
typedef int (*ast_bridge_channel_post_action_data)(struct ast_bridge_channel *bridge_channel, enum bridge_channel_action_type action, const void *data, size_t datalen);
 
/*!
 * \brief Counter used for assigning synchronous bridge action IDs
 */
static int sync_ids;
 
/*!
 * \brief Frame payload for synchronous bridge actions.
 *
 * The payload serves as a wrapper around the actual payload of the
 * frame, with the addition of an id used to find the associated
 * bridge_sync object.
 */
struct sync_payload {
    /*! Unique ID for this synchronous action */
    unsigned int id;
    /*! Actual frame data to process */
    unsigned char data[0];
};
 
/*!
 * \brief Synchronous bridge action object.
 *
 * Synchronous bridge actions require the ability for one thread to wait
 * and for another thread to indicate that the action has completed. This
 * structure facilitates that goal by providing synchronization structures.
 */
struct bridge_sync {
    /*! Unique ID of this synchronization object. Corresponds with ID in synchronous frame payload */
    unsigned int id;
    /*! Semaphore used for synchronization */
    struct ast_sem sem;
    /*! Pointer to next entry in the list */
    AST_LIST_ENTRY(bridge_sync) list;
};
 
/*!
 * \brief List holding active synchronous action objects.
 */
static AST_RWLIST_HEAD_STATIC(sync_structs, bridge_sync);
 
/*!
 * \brief Initialize a synchronous bridge object.
 *
 * This both initializes the structure and adds it to the list of
 * synchronization structures.
 *
 * \param sync_struct The synchronization object to initialize.
 * \param id ID to assign to the synchronization object.
 */
static void bridge_sync_init(struct bridge_sync *sync_struct, unsigned int id)
{
    memset(sync_struct, 0, sizeof(*sync_struct));
    sync_struct->id = id;
    ast_sem_init(&sync_struct->sem, 0, 0);
 
    AST_RWLIST_WRLOCK(&sync_structs);
    AST_RWLIST_INSERT_TAIL(&sync_structs, sync_struct, list);
    AST_RWLIST_UNLOCK(&sync_structs);
}
 
/*!
 * \brief Clean up a synchronization bridge object.
 *
 * This frees fields within the synchronization object and removes
 * it from the list of active synchronization objects.
 *
 * Since synchronization objects are stack-allocated, it is vital
 * that this is called before the synchronization object goes
 * out of scope.
 *
 * \param sync_struct Synchronization object to clean up.
 */
static void bridge_sync_cleanup(struct bridge_sync *sync_struct)
{
    struct bridge_sync *iter;
 
    AST_RWLIST_WRLOCK(&sync_structs);
    AST_LIST_TRAVERSE_SAFE_BEGIN(&sync_structs, iter, list) {
        if (iter->id == sync_struct->id) {
            AST_LIST_REMOVE_CURRENT(list);
            break;
        }
    }
    AST_LIST_TRAVERSE_SAFE_END;
    AST_RWLIST_UNLOCK(&sync_structs);
 
    ast_sem_destroy(&sync_struct->sem);
}
 
/*!
 * \brief Failsafe for synchronous bridge action waiting.
 *
 * When waiting for a synchronous bridge action to complete,
 * if there is a frame resource leak somewhere, it is possible
 * that we will never get notified that the synchronous action
 * completed.
 *
 * If a significant amount of time passes, then we will abandon
 * waiting for the synchrnous bridge action to complete.
 *
 * This constant represents the number of milliseconds we will
 * wait for the bridge action to complete.
 */
#define PLAYBACK_TIMEOUT (600 * 1000)
 
/*!
 * \brief Wait for a synchronous bridge action to complete.
 *
 * \param sync_struct Synchronization object corresponding to the bridge action.
 */
static void bridge_sync_wait(struct bridge_sync *sync_struct)
{
    struct timeval timeout_val = ast_tvadd(ast_tvnow(), ast_samp2tv(PLAYBACK_TIMEOUT, 1000));
    struct timespec timeout_spec = {
        .tv_sec = timeout_val.tv_sec,
        .tv_nsec = timeout_val.tv_usec * 1000,
    };
 
    ast_sem_timedwait(&sync_struct->sem, &timeout_spec);
}
 
/*!
 * \brief Signal that waiting for a synchronous bridge action is no longer necessary.
 *
 * This may occur for several reasons
 * \li The synchronous bridge action has completed.
 * \li The bridge channel has been removed from the bridge.
 * \li The synchronous bridge action could not be queued.
 *
 * \param sync_struct Synchronization object corresponding to the bridge action.
 */
static void bridge_sync_signal(struct bridge_sync *sync_struct)
{
    ast_sem_post(&sync_struct->sem);
}
 
struct ast_channel *ast_bridge_channel_get_chan(struct ast_bridge_channel *bridge_channel)
{
    struct ast_channel *chan;
 
    ao2_lock(bridge_channel);
    chan = ao2_bump(bridge_channel->chan);
    ao2_unlock(bridge_channel);
 
    return chan;
}
 
void ast_bridge_channel_lock_bridge(struct ast_bridge_channel *bridge_channel)
{
    struct ast_bridge *bridge;
 
    for (;;) {
        /* Safely get the bridge pointer */
        ast_bridge_channel_lock(bridge_channel);
        bridge = bridge_channel->bridge;
        ao2_ref(bridge, +1);
        ast_bridge_channel_unlock(bridge_channel);
 
        /* Lock the bridge and see if it is still the bridge we need to lock. */
        ast_bridge_lock(bridge);
        if (bridge == bridge_channel->bridge) {
            ao2_ref(bridge, -1);
            return;
        }
        ast_bridge_unlock(bridge);
        ao2_ref(bridge, -1);
    }
}
 
int ast_bridge_channel_notify_talking(struct ast_bridge_channel *bridge_channel, int started_talking)
{
    struct ast_frame action = {
        .frametype = AST_FRAME_BRIDGE_ACTION,
        .subclass.integer = started_talking
            ? BRIDGE_CHANNEL_ACTION_TALKING_START : BRIDGE_CHANNEL_ACTION_TALKING_STOP,
    };
 
    return ast_bridge_channel_queue_frame(bridge_channel, &action);
}
 
/*!
 * \internal
 * \brief Poke the bridge_channel thread
 */
static void bridge_channel_poke(struct ast_bridge_channel *bridge_channel)
{
    if (!pthread_equal(pthread_self(), bridge_channel->thread)) {
        /* Wake up the bridge channel thread. */
        ast_queue_frame(bridge_channel->chan, &ast_null_frame);
    }
}
 
/*!
 * \internal
 * \brief Set actual cause on channel.
 * \since 12.0.0
 *
 * \param chan Channel to set cause.
 * \param cause Cause to set on channel.
 *   If cause <= 0 then use cause on channel if cause still <= 0 use AST_CAUSE_NORMAL_CLEARING.
 *
 * \return Actual cause set on channel.
 */
static int channel_set_cause(struct ast_channel *chan, int cause)
{
    int current_cause;
    ast_channel_lock(chan);
    current_cause = ast_channel_hangupcause(chan);
 
    /* if the hangupcause is already set, leave it */
    if (current_cause > 0) {
        ast_channel_unlock(chan);
        return current_cause;
    }
 
    if (cause <= 0) {
        cause = ast_channel_hangupcause(chan);
        if (cause <= 0) {
            cause = AST_CAUSE_NORMAL_CLEARING;
        }
    }
 
    ast_channel_hangupcause_set(chan, cause);
    ast_channel_unlock(chan);
    return cause;
}
 
void ast_bridge_channel_leave_bridge_nolock(struct ast_bridge_channel *bridge_channel, enum bridge_channel_state new_state, int cause)
{
    if (bridge_channel->state != BRIDGE_CHANNEL_STATE_WAIT) {
        return;
    }
 
    ast_debug(1, "Setting %p(%s) state from:%u to:%u\n",
        bridge_channel, ast_channel_name(bridge_channel->chan), bridge_channel->state,
        new_state);
 
    channel_set_cause(bridge_channel->chan, cause);
 
    ast_channel_lock(bridge_channel->chan);
    ast_bridge_vars_set(bridge_channel->chan, NULL, NULL);
    ast_channel_unlock(bridge_channel->chan);
 
    /* Change the state on the bridge channel */
    bridge_channel->state = new_state;
 
    bridge_channel_poke(bridge_channel);
}
 
void ast_bridge_channel_leave_bridge(struct ast_bridge_channel *bridge_channel, enum bridge_channel_state new_state, int cause)
{
    ast_bridge_channel_lock(bridge_channel);
    ast_bridge_channel_leave_bridge_nolock(bridge_channel, new_state, cause);
    ast_bridge_channel_unlock(bridge_channel);
}
 
struct ast_bridge_channel *ast_bridge_channel_peer(struct ast_bridge_channel *bridge_channel)
{
    struct ast_bridge *bridge = bridge_channel->bridge;
    struct ast_bridge_channel *other = NULL;
 
    if (bridge_channel->in_bridge && bridge->num_channels == 2) {
        AST_LIST_TRAVERSE(&bridge->channels, other, entry) {
            if (other != bridge_channel) {
                break;
            }
        }
    }
 
    return other;
}
 
void ast_bridge_channel_restore_formats(struct ast_bridge_channel *bridge_channel)
{
    ast_assert(bridge_channel->read_format != NULL);
    ast_assert(bridge_channel->write_format != NULL);
 
    ast_channel_lock(bridge_channel->chan);
 
    /* Restore original formats of the channel as they came in */
    if (ast_format_cmp(ast_channel_readformat(bridge_channel->chan), bridge_channel->read_format) == AST_FORMAT_CMP_NOT_EQUAL) {
        ast_debug(1, "Bridge is returning %p(%s) to read format %s\n",
            bridge_channel, ast_channel_name(bridge_channel->chan),
            ast_format_get_name(bridge_channel->read_format));
        if (ast_set_read_format(bridge_channel->chan, bridge_channel->read_format)) {
            ast_debug(1, "Bridge failed to return %p(%s) to read format %s\n",
                bridge_channel, ast_channel_name(bridge_channel->chan),
                ast_format_get_name(bridge_channel->read_format));
        }
    }
    if (ast_format_cmp(ast_channel_writeformat(bridge_channel->chan), bridge_channel->write_format) == AST_FORMAT_CMP_NOT_EQUAL) {
        ast_debug(1, "Bridge is returning %p(%s) to write format %s\n",
            bridge_channel, ast_channel_name(bridge_channel->chan),
            ast_format_get_name(bridge_channel->write_format));
        if (ast_set_write_format(bridge_channel->chan, bridge_channel->write_format)) {
            ast_debug(1, "Bridge failed to return %p(%s) to write format %s\n",
                bridge_channel, ast_channel_name(bridge_channel->chan),
                ast_format_get_name(bridge_channel->write_format));
        }
    }
 
    ast_channel_unlock(bridge_channel->chan);
}
 
struct ast_bridge *ast_bridge_channel_merge_inhibit(struct ast_bridge_channel *bridge_channel, int request)
{
    struct ast_bridge *bridge;
 
    ast_bridge_channel_lock_bridge(bridge_channel);
    bridge = bridge_channel->bridge;
    ao2_ref(bridge, +1);
    bridge_merge_inhibit_nolock(bridge, request);
    ast_bridge_unlock(bridge);
    return bridge;
}
 
void ast_bridge_channel_update_linkedids(struct ast_bridge_channel *bridge_channel, struct ast_bridge_channel *swap)
{
    struct ast_bridge_channel *other;
    struct ast_bridge *bridge = bridge_channel->bridge;
    struct ast_channel *oldest_linkedid_chan = bridge_channel->chan;
 
    AST_LIST_TRAVERSE(&bridge->channels, other, entry) {
        if (other == swap) {
            continue;
        }
        oldest_linkedid_chan = ast_channel_internal_oldest_linkedid(
            oldest_linkedid_chan, other->chan);
    }
 
    ast_channel_lock(bridge_channel->chan);
    ast_channel_internal_copy_linkedid(bridge_channel->chan, oldest_linkedid_chan);
    ast_channel_unlock(bridge_channel->chan);
    AST_LIST_TRAVERSE(&bridge->channels, other, entry) {
        if (other == swap) {
            continue;
        }
        ast_channel_lock(other->chan);
        ast_channel_internal_copy_linkedid(other->chan, oldest_linkedid_chan);
        ast_channel_unlock(other->chan);
    }
}
 
/*!
 * \internal
 * \brief Set dest's empty peeraccount with the src's non-empty accountcode.
 * \since 12.5.0
 *
 * \param dest Channel to update peeraccount.
 * \param src Channel to get accountcode from.
 *
 * \note Both channels are already locked.
 */
static void channel_fill_empty_peeraccount(struct ast_channel *dest, struct ast_channel *src)
{
    if (ast_strlen_zero(ast_channel_peeraccount(dest))
        && !ast_strlen_zero(ast_channel_accountcode(src))) {
        ast_debug(1, "Setting channel %s peeraccount with channel %s accountcode '%s'.\n",
            ast_channel_name(dest),
            ast_channel_name(src), ast_channel_accountcode(src));
        ast_channel_peeraccount_set(dest, ast_channel_accountcode(src));
    }
}
 
/*!
 * \internal
 * \brief Set dest's empty accountcode with the src's non-empty peeraccount.
 * \since 12.5.0
 *
 * \param dest Channel to update accountcode.
 * \param src Channel to get peeraccount from.
 *
 * \note Both channels are already locked.
 */
static void channel_fill_empty_accountcode(struct ast_channel *dest, struct ast_channel *src)
{
    if (ast_strlen_zero(ast_channel_accountcode(dest))
        && !ast_strlen_zero(ast_channel_peeraccount(src))) {
        ast_debug(1, "Setting channel %s accountcode with channel %s peeraccount '%s'.\n",
            ast_channel_name(dest),
            ast_channel_name(src), ast_channel_peeraccount(src));
        ast_channel_accountcode_set(dest, ast_channel_peeraccount(src));
    }
}
 
/*!
 * \internal
 * \brief Set empty peeraccount and accountcode in a channel from the other channel.
 * \since 12.5.0
 *
 * \param c0 First bridge channel to update.
 * \param c1 Second bridge channel to update.
 *
 * \note Both channels are already locked.
 */
static void channel_set_empty_accountcodes(struct ast_channel *c0, struct ast_channel *c1)
{
    /* Set empty peeraccount from the other channel's accountcode. */
    channel_fill_empty_peeraccount(c0, c1);
    channel_fill_empty_peeraccount(c1, c0);
 
    /* Set empty accountcode from the other channel's peeraccount. */
    channel_fill_empty_accountcode(c0, c1);
    channel_fill_empty_accountcode(c1, c0);
}
 
/*!
 * \internal
 * \brief Update dest's peeraccount with the src's different accountcode.
 * \since 12.5.0
 *
 * \param dest Channel to update peeraccount.
 * \param src Channel to get accountcode from.
 *
 * \note Both channels are already locked.
 */
static void channel_update_peeraccount(struct ast_channel *dest, struct ast_channel *src)
{
    if (strcmp(ast_channel_accountcode(src), ast_channel_peeraccount(dest))) {
        ast_debug(1, "Changing channel %s peeraccount '%s' to match channel %s accountcode '%s'.\n",
            ast_channel_name(dest), ast_channel_peeraccount(dest),
            ast_channel_name(src), ast_channel_accountcode(src));
        ast_channel_peeraccount_set(dest, ast_channel_accountcode(src));
    }
}
 
/*!
 * \internal
 * \brief Update peeraccounts to match the other channel's accountcode.
 * \since 12.5.0
 *
 * \param c0 First channel to update.
 * \param c1 Second channel to update.
 *
 * \note Both channels are already locked.
 */
static void channel_update_peeraccounts(struct ast_channel *c0, struct ast_channel *c1)
{
    channel_update_peeraccount(c0, c1);
    channel_update_peeraccount(c1, c0);
}
 
/*!
 * \internal
 * \brief Update channel accountcodes because a channel is joining a bridge.
 * \since 12.5.0
 *
 * \param joining Channel joining the bridge.
 * \param swap Channel being replaced by the joining channel.  May be NULL.
 *
 * \note The bridge must be locked prior to calling this function.
 */
static void bridge_channel_update_accountcodes_joining(struct ast_bridge_channel *joining, struct ast_bridge_channel *swap)
{
    struct ast_bridge *bridge = joining->bridge;
    struct ast_bridge_channel *other;
    unsigned int swap_in_bridge = 0;
    unsigned int will_be_two_party;
 
    /*
     * Only update the peeraccount to match if the joining channel
     * will make it a two party bridge.
     */
    if (bridge->num_channels <= 2 && swap) {
        AST_LIST_TRAVERSE(&bridge->channels, other, entry) {
            if (other == swap) {
                swap_in_bridge = 1;
                break;
            }
        }
    }
    will_be_two_party = (1 == bridge->num_channels - swap_in_bridge);
 
    AST_LIST_TRAVERSE(&bridge->channels, other, entry) {
        if (other == swap) {
            continue;
        }
        ast_assert(joining != other);
        ast_channel_lock_both(joining->chan, other->chan);
        channel_set_empty_accountcodes(joining->chan, other->chan);
        if (will_be_two_party) {
            channel_update_peeraccounts(joining->chan, other->chan);
        }
        ast_channel_unlock(joining->chan);
        ast_channel_unlock(other->chan);
    }
}
 
/*!
 * \internal
 * \brief Update channel peeraccount codes because a channel has left a bridge.
 * \since 12.5.0
 *
 * \param leaving Channel leaving the bridge. (Has already been removed actually)
 *
 * \note The bridge must be locked prior to calling this function.
 */
static void bridge_channel_update_accountcodes_leaving(struct ast_bridge_channel *leaving)
{
    struct ast_bridge *bridge = leaving->bridge;
    struct ast_bridge_channel *first;
    struct ast_bridge_channel *second;
 
    if (bridge->num_channels != 2 || bridge->dissolved) {
        return;
    }
 
    first = AST_LIST_FIRST(&bridge->channels);
    second = AST_LIST_LAST(&bridge->channels);
    ast_assert(first && first != second);
    ast_channel_lock_both(first->chan, second->chan);
    channel_set_empty_accountcodes(first->chan, second->chan);
    channel_update_peeraccounts(first->chan, second->chan);
    ast_channel_unlock(second->chan);
    ast_channel_unlock(first->chan);
}
 
void ast_bridge_channel_update_accountcodes(struct ast_bridge_channel *joining, struct ast_bridge_channel *leaving)
{
    if (joining) {
        bridge_channel_update_accountcodes_joining(joining, leaving);
    } else {
        bridge_channel_update_accountcodes_leaving(leaving);
    }
}
 
void ast_bridge_channel_kick(struct ast_bridge_channel *bridge_channel, int cause)
{
    struct ast_bridge_features *features = bridge_channel->features;
    struct ast_bridge_hook *hook;
    struct ao2_iterator iter;
 
    ast_bridge_channel_lock(bridge_channel);
    if (bridge_channel->state == BRIDGE_CHANNEL_STATE_WAIT) {
        channel_set_cause(bridge_channel->chan, cause);
        cause = 0;
    }
    ast_bridge_channel_unlock(bridge_channel);
 
    /* Run any hangup hooks. */
    iter = ao2_iterator_init(features->other_hooks, 0);
    for (; (hook = ao2_iterator_next(&iter)); ao2_ref(hook, -1)) {
        int remove_me;
 
        if (hook->type != AST_BRIDGE_HOOK_TYPE_HANGUP) {
            continue;
        }
        remove_me = hook->callback(bridge_channel, hook->hook_pvt);
        if (remove_me) {
            ast_debug(1, "Hangup hook %p is being removed from %p(%s)\n",
                hook, bridge_channel, ast_channel_name(bridge_channel->chan));
            ao2_unlink(features->other_hooks, hook);
        }
    }
    ao2_iterator_destroy(&iter);
 
    /* Default hangup action. */
    ast_bridge_channel_leave_bridge(bridge_channel, BRIDGE_CHANNEL_STATE_END, cause);
}
 
/*!
 * \internal
 * \brief Write an \ref ast_frame into the bridge
 * \since 12.0.0
 *
 * \param bridge_channel Which channel is queueing the frame.
 * \param frame The frame to write into the bridge
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int bridge_channel_write_frame(struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
{
    const struct ast_control_t38_parameters *t38_parameters;
    int unmapped_stream_num;
    int deferred;
 
    ast_assert(frame->frametype != AST_FRAME_BRIDGE_ACTION_SYNC);
 
    ast_bridge_channel_lock_bridge(bridge_channel);
 
    /*
     * Map the frame to the bridge.
     * We need to lock the bridge_channel to make sure that bridge_channel->chan
     * isn't NULL and keep it locked while we do multistream processing.
     */
    ast_bridge_channel_lock(bridge_channel);
    if (bridge_channel->chan && ast_channel_is_multistream(bridge_channel->chan)) {
        unmapped_stream_num = frame->stream_num;
        switch (frame->frametype) {
        case AST_FRAME_VOICE:
        case AST_FRAME_VIDEO:
        case AST_FRAME_TEXT:
        case AST_FRAME_IMAGE:
        case AST_FRAME_RTCP:
            /* These frames need to be mapped to an appropriate write stream */
            if (frame->stream_num < 0) {
                /* Map to default stream */
                frame->stream_num = -1;
                break;
            }
            if (frame->stream_num < (int)AST_VECTOR_SIZE(&bridge_channel->stream_map.to_bridge)) {
                frame->stream_num = AST_VECTOR_GET(
                    &bridge_channel->stream_map.to_bridge, frame->stream_num);
                if (0 <= frame->stream_num) {
                    break;
                }
            }
            ast_bridge_channel_unlock(bridge_channel);
            ast_bridge_unlock(bridge_channel->bridge);
            /*
             * Ignore frame because we don't know how to map the frame
             * or the bridge is not expecting any media from that
             * stream.
             */
            return 0;
        case AST_FRAME_DTMF_BEGIN:
        case AST_FRAME_DTMF_END:
            /*
             * XXX It makes sense that DTMF could be on any audio stream.
             * For now we will only put it on the default audio stream.
             */
        default:
            frame->stream_num = -1;
            break;
        }
    } else {
        unmapped_stream_num = -1;
        frame->stream_num = -1;
    }
    ast_bridge_channel_unlock(bridge_channel);
 
    deferred = bridge_channel->bridge->technology->write(bridge_channel->bridge, bridge_channel, frame);
    if (deferred) {
        struct ast_frame *dup;
 
        dup = ast_frdup(frame);
        if (dup) {
            /*
             * We have to unmap the deferred frame so it comes back
             * in like a new frame.
             */
            dup->stream_num = unmapped_stream_num;
            ast_bridge_channel_lock(bridge_channel);
            AST_LIST_INSERT_HEAD(&bridge_channel->deferred_queue, dup, frame_list);
            ast_bridge_channel_unlock(bridge_channel);
        }
    }
 
    /* Remember any owed events to the bridge. */
    switch (frame->frametype) {
    case AST_FRAME_DTMF_BEGIN:
        bridge_channel->owed.dtmf_tv = ast_tvnow();
        bridge_channel->owed.dtmf_digit = frame->subclass.integer;
        break;
    case AST_FRAME_DTMF_END:
        bridge_channel->owed.dtmf_digit = '\0';
        break;
    case AST_FRAME_CONTROL:
        /*
         * We explicitly will not remember HOLD/UNHOLD frames because
         * things like attended transfers will handle them.
         */
        switch (frame->subclass.integer) {
        case AST_CONTROL_T38_PARAMETERS:
            t38_parameters = frame->data.ptr;
            switch (t38_parameters->request_response) {
            case AST_T38_REQUEST_NEGOTIATE:
            case AST_T38_NEGOTIATED:
                bridge_channel->owed.t38_terminate = 1;
                break;
            case AST_T38_REQUEST_TERMINATE:
            case AST_T38_TERMINATED:
            case AST_T38_REFUSED:
                bridge_channel->owed.t38_terminate = 0;
                break;
            default:
                break;
            }
            break;
        default:
            break;
        }
        break;
    default:
        break;
    }
    ast_bridge_unlock(bridge_channel->bridge);
 
    /*
     * Claim successful write to bridge.  If deferred frame
     * support is added, claim successfully deferred.
     */
    return 0;
}
 
/*!
 * \internal
 * \brief Cancel owed events by the channel to the bridge.
 * \since 13.8.0
 *
 * \param bridge_channel Channel that owes events to the bridge.
 *
 * \note On entry, the bridge_channel->bridge is already locked.
 */
static void bridge_channel_cancel_owed_events(struct ast_bridge_channel *bridge_channel)
{
    bridge_channel->owed.dtmf_digit = '\0';
    bridge_channel->owed.t38_terminate = 0;
}
 
void bridge_channel_settle_owed_events(struct ast_bridge *orig_bridge, struct ast_bridge_channel *bridge_channel)
{
    if (bridge_channel->owed.dtmf_digit) {
        struct ast_frame frame = {
            .frametype = AST_FRAME_DTMF_END,
            .subclass.integer = bridge_channel->owed.dtmf_digit,
            .src = "Bridge channel owed DTMF",
        };
 
        frame.len = ast_tvdiff_ms(ast_tvnow(), bridge_channel->owed.dtmf_tv);
        if (frame.len < option_dtmfminduration) {
            frame.len = option_dtmfminduration;
        }
        ast_log(LOG_DTMF, "DTMF end '%c' simulated to bridge %s because %s left.  Duration %ld ms.\n",
            bridge_channel->owed.dtmf_digit, orig_bridge->uniqueid,
            ast_channel_name(bridge_channel->chan), frame.len);
        bridge_channel->owed.dtmf_digit = '\0';
        orig_bridge->technology->write(orig_bridge, NULL, &frame);
    }
    if (bridge_channel->owed.t38_terminate) {
        struct ast_control_t38_parameters t38_parameters = {
            .request_response = AST_T38_TERMINATED,
        };
        struct ast_frame frame = {
            .frametype = AST_FRAME_CONTROL,
            .subclass.integer = AST_CONTROL_T38_PARAMETERS,
            .data.ptr = &t38_parameters,
            .datalen = sizeof(t38_parameters),
            .src = "Bridge channel owed T.38 terminate",
        };
 
        ast_debug(1, "T.38 terminate simulated to bridge %s because %s left.\n",
            orig_bridge->uniqueid, ast_channel_name(bridge_channel->chan));
        bridge_channel->owed.t38_terminate = 0;
        orig_bridge->technology->write(orig_bridge, NULL, &frame);
    }
}
 
void bridge_channel_queue_deferred_frames(struct ast_bridge_channel *bridge_channel)
{
    struct ast_frame *frame;
 
    ast_bridge_channel_lock(bridge_channel);
    ast_channel_lock(bridge_channel->chan);
    while ((frame = AST_LIST_REMOVE_HEAD(&bridge_channel->deferred_queue, frame_list))) {
        ast_queue_frame_head(bridge_channel->chan, frame);
        ast_frfree(frame);
    }
    ast_channel_unlock(bridge_channel->chan);
    ast_bridge_channel_unlock(bridge_channel);
}
 
void bridge_channel_internal_suspend_nolock(struct ast_bridge_channel *bridge_channel)
{
    bridge_channel->suspended = 1;
    if (bridge_channel->in_bridge) {
        --bridge_channel->bridge->num_active;
    }
 
    /* Get technology bridge threads off of the channel. */
    if (bridge_channel->bridge->technology->suspend) {
        bridge_channel->bridge->technology->suspend(bridge_channel->bridge, bridge_channel);
    }
}
 
/*!
 * \internal
 * \brief Suspend a channel from a bridge.
 *
 * \param bridge_channel Channel to suspend.
 */
static void bridge_channel_suspend(struct ast_bridge_channel *bridge_channel)
{
    ast_bridge_channel_lock_bridge(bridge_channel);
    bridge_channel_internal_suspend_nolock(bridge_channel);
    ast_bridge_unlock(bridge_channel->bridge);
}
 
void bridge_channel_internal_unsuspend_nolock(struct ast_bridge_channel *bridge_channel)
{
    bridge_channel->suspended = 0;
    if (bridge_channel->in_bridge) {
        ++bridge_channel->bridge->num_active;
    }
 
    /* Wake technology bridge threads to take care of channel again. */
    if (bridge_channel->bridge->technology->unsuspend) {
        bridge_channel->bridge->technology->unsuspend(bridge_channel->bridge, bridge_channel);
    }
 
    /* Wake suspended channel. */
    ast_bridge_channel_lock(bridge_channel);
    ast_cond_signal(&bridge_channel->cond);
    ast_bridge_channel_unlock(bridge_channel);
}
 
/*!
 * \internal
 * \brief Unsuspend a channel from a bridge.
 *
 * \param bridge_channel Channel to unsuspend.
 */
static void bridge_channel_unsuspend(struct ast_bridge_channel *bridge_channel)
{
    ast_bridge_channel_lock_bridge(bridge_channel);
    bridge_channel_internal_unsuspend_nolock(bridge_channel);
    ast_bridge_unlock(bridge_channel->bridge);
}
 
/*!
 * \internal
 * \brief Queue an action frame onto the bridge channel with data.
 * \since 12.0.0
 *
 * \param bridge_channel Which channel to queue the frame onto.
 * \param action Type of bridge action frame.
 * \param data Frame payload data to pass.
 * \param datalen Frame payload data length to pass.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int bridge_channel_queue_action_data(struct ast_bridge_channel *bridge_channel,
    enum bridge_channel_action_type action, const void *data, size_t datalen)
{
    struct ast_frame frame = {
        .frametype = AST_FRAME_BRIDGE_ACTION,
        .subclass.integer = action,
        .datalen = datalen,
        .data.ptr = (void *) data,
    };
 
    return ast_bridge_channel_queue_frame(bridge_channel, &frame);
}
 
/*!
 * \internal
 * \brief Queue an action frame onto the bridge channel with data synchronously.
 * \since 12.2.0
 *
 * The function will not return until the queued frame is freed.
 *
 * \param bridge_channel Which channel to queue the frame onto.
 * \param action Type of bridge action frame.
 * \param data Frame payload data to pass.
 * \param datalen Frame payload data length to pass.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int bridge_channel_queue_action_data_sync(struct ast_bridge_channel *bridge_channel,
    enum bridge_channel_action_type action, const void *data, size_t datalen)
{
    struct sync_payload *sync_payload;
    int sync_payload_len = sizeof(*sync_payload) + datalen;
    struct bridge_sync sync_struct;
    struct ast_frame frame = {
        .frametype = AST_FRAME_BRIDGE_ACTION_SYNC,
        .subclass.integer = action,
    };
 
    /* Make sure we don't end up trying to wait on ourself to deliver the frame */
    ast_assert(!pthread_equal(pthread_self(), bridge_channel->thread));
 
    sync_payload = ast_alloca(sync_payload_len);
    sync_payload->id = ast_atomic_fetchadd_int(&sync_ids, +1);
    memcpy(sync_payload->data, data, datalen);
 
    frame.datalen = sync_payload_len;
    frame.data.ptr = sync_payload;
 
    bridge_sync_init(&sync_struct, sync_payload->id);
    if (ast_bridge_channel_queue_frame(bridge_channel, &frame)) {
        bridge_sync_cleanup(&sync_struct);
        return -1;
    }
 
    bridge_sync_wait(&sync_struct);
    bridge_sync_cleanup(&sync_struct);
    return 0;
}
/*!
 * \internal
 * \brief Write an action frame onto the bridge channel with data.
 * \since 12.0.0
 *
 * \param bridge_channel Which channel to queue the frame onto.
 * \param action Type of bridge action frame.
 * \param data Frame payload data to pass.
 * \param datalen Frame payload data length to pass.
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int bridge_channel_write_action_data(struct ast_bridge_channel *bridge_channel,
    enum bridge_channel_action_type action, const void *data, size_t datalen)
{
    struct ast_frame frame = {
        .frametype = AST_FRAME_BRIDGE_ACTION,
        .subclass.integer = action,
        .datalen = datalen,
        .data.ptr = (void *) data,
    };
 
    return bridge_channel_write_frame(bridge_channel, &frame);
}
 
static void bridge_frame_free(struct ast_frame *frame)
{
    if (frame->frametype == AST_FRAME_BRIDGE_ACTION_SYNC) {
        struct sync_payload *sync_payload = frame->data.ptr;
        struct bridge_sync *sync;
 
        AST_RWLIST_RDLOCK(&sync_structs);
        AST_RWLIST_TRAVERSE(&sync_structs, sync, list) {
            if (sync->id == sync_payload->id) {
                break;
            }
        }
        if (sync) {
            bridge_sync_signal(sync);
        }
        AST_RWLIST_UNLOCK(&sync_structs);
    }
 
    ast_frfree(frame);
}
 
int ast_bridge_channel_queue_frame(struct ast_bridge_channel *bridge_channel, struct ast_frame *fr)
{
    struct ast_frame *dup;
 
    if (bridge_channel->suspended
        /* Also defer DTMF frames. */
        && fr->frametype != AST_FRAME_DTMF_BEGIN
        && fr->frametype != AST_FRAME_DTMF_END
        && !ast_is_deferrable_frame(fr)) {
        /* Drop non-deferable frames when suspended. */
        return 0;
    }
    if (fr->frametype == AST_FRAME_NULL) {
        /* "Accept" the frame and discard it. */
        return 0;
    }
 
    if ((fr->frametype == AST_FRAME_VOICE || fr->frametype == AST_FRAME_VIDEO ||
        fr->frametype == AST_FRAME_TEXT || fr->frametype == AST_FRAME_IMAGE ||
        fr->frametype == AST_FRAME_RTCP) && fr->stream_num > -1) {
        int num = -1;
 
        ast_bridge_channel_lock(bridge_channel);
        if (fr->stream_num < (int)AST_VECTOR_SIZE(&bridge_channel->stream_map.to_channel)) {
            num = AST_VECTOR_GET(&bridge_channel->stream_map.to_channel, fr->stream_num);
        }
        ast_bridge_channel_unlock(bridge_channel);
 
        if (num == -1) {
            /* We don't have a mapped stream so just discard this frame. */
            return 0;
        }
    }
 
    dup = ast_frdup(fr);
    if (!dup) {
        return -1;
    }
 
    ast_bridge_channel_lock(bridge_channel);
    if (bridge_channel->state != BRIDGE_CHANNEL_STATE_WAIT) {
        /* Drop frames on channels leaving the bridge. */
        ast_bridge_channel_unlock(bridge_channel);
        bridge_frame_free(dup);
        return 0;
    }
 
    if ((fr->frametype == AST_FRAME_TEXT || fr->frametype == AST_FRAME_TEXT_DATA) &&
        !bridge_channel->features->text_messaging) {
        /* This channel is not accepting text messages. */
        ast_bridge_channel_unlock(bridge_channel);
        bridge_frame_free(dup);
        return 0;
    }
 
    if (DEBUG_ATLEAST(1)) {
        if (fr->frametype == AST_FRAME_TEXT) {
            ast_log(LOG_DEBUG, "Queuing TEXT frame to '%s': %*.s\n", ast_channel_name(bridge_channel->chan),
                fr->datalen, (char *)fr->data.ptr);
        } else if (fr->frametype == AST_FRAME_TEXT_DATA) {
            struct ast_msg_data *msg = fr->data.ptr;
            ast_log(LOG_DEBUG, "Queueing TEXT_DATA frame from '%s' to '%s:%s': %s\n",
                ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_FROM),
                ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_TO),
                ast_channel_name(bridge_channel->chan),
                ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_BODY));
        }
    }
 
    AST_LIST_INSERT_TAIL(&bridge_channel->wr_queue, dup, frame_list);
    if (ast_alertpipe_write(bridge_channel->alert_pipe)) {
        ast_log(LOG_ERROR, "We couldn't write alert pipe for %p(%s)... something is VERY wrong\n",
            bridge_channel, ast_channel_name(bridge_channel->chan));
    }
    ast_bridge_channel_unlock(bridge_channel);
    return 0;
}
 
int ast_bridge_queue_everyone_else(struct ast_bridge *bridge, struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
{
    struct ast_bridge_channel *cur;
    int not_written = -1;
 
    if (frame->frametype == AST_FRAME_NULL) {
        /* "Accept" the frame and discard it. */
        return 0;
    }
 
    AST_LIST_TRAVERSE(&bridge->channels, cur, entry) {
        if (cur == bridge_channel) {
            continue;
        }
        if (!ast_bridge_channel_queue_frame(cur, frame)) {
            not_written = 0;
        }
    }
    return not_written;
}
 
int ast_bridge_channel_queue_control_data(struct ast_bridge_channel *bridge_channel, enum ast_control_frame_type control, const void *data, size_t datalen)
{
    struct ast_frame frame = {
        .frametype = AST_FRAME_CONTROL,
        .subclass.integer = control,
        .datalen = datalen,
        .data.ptr = (void *) data,
    };
 
    return ast_bridge_channel_queue_frame(bridge_channel, &frame);
}
 
int ast_bridge_channel_write_control_data(struct ast_bridge_channel *bridge_channel, enum ast_control_frame_type control, const void *data, size_t datalen)
{
    struct ast_frame frame = {
        .frametype = AST_FRAME_CONTROL,
        .subclass.integer = control,
        .datalen = datalen,
        .data.ptr = (void *) data,
    };
 
    return bridge_channel_write_frame(bridge_channel, &frame);
}
 
int ast_bridge_channel_write_hold(struct ast_bridge_channel *bridge_channel, const char *moh_class)
{
    struct ast_json *blob;
    int res;
    size_t datalen;
 
    if (!ast_strlen_zero(moh_class)) {
        datalen = strlen(moh_class) + 1;
 
        blob = ast_json_pack("{s: s}",
            "musicclass", moh_class);
    } else {
        moh_class = NULL;
        datalen = 0;
        blob = NULL;
    }
 
    ast_channel_publish_cached_blob(bridge_channel->chan, ast_channel_hold_type(), blob);
 
    res = ast_bridge_channel_write_control_data(bridge_channel, AST_CONTROL_HOLD,
        moh_class, datalen);
 
    ast_json_unref(blob);
    return res;
}
 
int ast_bridge_channel_write_unhold(struct ast_bridge_channel *bridge_channel)
{
    struct ast_channel *chan = ast_bridge_channel_get_chan(bridge_channel);
 
    if (!chan) {
        return -1;
    }
 
    ast_channel_publish_cached_blob(chan, ast_channel_unhold_type(), NULL);
    ao2_ref(chan, -1);
 
    return ast_bridge_channel_write_control_data(bridge_channel, AST_CONTROL_UNHOLD, NULL, 0);
}
 
/*!
 * \internal
 * \brief Helper function to kick off a PBX app on a bridge_channel
 */
static int run_app_helper(struct ast_channel *chan, const char *app_name, const char *app_args)
{
    int res = 0;
 
    if (!strcasecmp("Gosub", app_name)) {
        ast_app_exec_sub(NULL, chan, app_args, 0);
    } else {
        res = ast_pbx_exec_application(chan, app_name, app_args);
    }
    return res;
}
 
void ast_bridge_channel_run_app(struct ast_bridge_channel *bridge_channel, const char *app_name, const char *app_args, const char *moh_class)
{
    if (moh_class) {
        ast_bridge_channel_write_hold(bridge_channel, moh_class);
    }
    if (run_app_helper(bridge_channel->chan, app_name, S_OR(app_args, ""))) {
        /* Break the bridge if the app returns non-zero. */
        ast_bridge_channel_kick(bridge_channel, AST_CAUSE_NORMAL_CLEARING);
    }
    if (moh_class) {
        ast_bridge_channel_write_unhold(bridge_channel);
    }
}
 
struct bridge_run_app {
    /*! Offset into app_name[] where the MOH class name starts.  (zero if no MOH) */
    int moh_offset;
    /*! Offset into app_name[] where the application argument string starts. (zero if no arguments) */
    int app_args_offset;
    /*! Application name to run. */
    char app_name[0];
};
 
/*!
 * \internal
 * \brief Handle the run application bridge action.
 * \since 12.0.0
 *
 * \param bridge_channel Which channel to run the application on.
 * \param data Action frame data to run the application.
 */
static void bridge_channel_run_app(struct ast_bridge_channel *bridge_channel, struct bridge_run_app *data)
{
    ast_bridge_channel_run_app(bridge_channel, data->app_name,
        data->app_args_offset ? &data->app_name[data->app_args_offset] : NULL,
        data->moh_offset ? &data->app_name[data->moh_offset] : NULL);
}
 
/*!
 * \internal
 * \brief Marshal an application to be executed on a bridge_channel
 */
static int payload_helper_app(ast_bridge_channel_post_action_data post_it,
    struct ast_bridge_channel *bridge_channel, const char *app_name, const char *app_args, const char *moh_class)
{
    struct bridge_run_app *app_data;
    size_t len_name = strlen(app_name) + 1;
    size_t len_args = ast_strlen_zero(app_args) ? 0 : strlen(app_args) + 1;
    size_t len_moh = !moh_class ? 0 : strlen(moh_class) + 1;
    size_t len_data = sizeof(*app_data) + len_name + len_args + len_moh;
 
    /* Fill in application run frame data. */
    app_data = alloca(len_data);
    app_data->app_args_offset = len_args ? len_name : 0;
    app_data->moh_offset = len_moh ? len_name + len_args : 0;
    strcpy(app_data->app_name, app_name);/* Safe */
    if (len_args) {
        strcpy(&app_data->app_name[app_data->app_args_offset], app_args);/* Safe */
    }
    if (moh_class) {
        strcpy(&app_data->app_name[app_data->moh_offset], moh_class);/* Safe */
    }
 
    return post_it(bridge_channel, BRIDGE_CHANNEL_ACTION_RUN_APP, app_data, len_data);
}
 
int ast_bridge_channel_write_app(struct ast_bridge_channel *bridge_channel, const char *app_name, const char *app_args, const char *moh_class)
{
    return payload_helper_app(bridge_channel_write_action_data,
        bridge_channel, app_name, app_args, moh_class);
}
 
int ast_bridge_channel_queue_app(struct ast_bridge_channel *bridge_channel, const char *app_name, const char *app_args, const char *moh_class)
{
    return payload_helper_app(bridge_channel_queue_action_data,
        bridge_channel, app_name, app_args, moh_class);
}
 
void ast_bridge_channel_playfile(struct ast_bridge_channel *bridge_channel, ast_bridge_custom_play_fn custom_play, const char *playfile, const char *moh_class)
{
    if (moh_class) {
        ast_bridge_channel_write_hold(bridge_channel, moh_class);
    }
    if (custom_play) {
        custom_play(bridge_channel, playfile);
    } else {
        ast_stream_and_wait(bridge_channel->chan, playfile, AST_DIGIT_NONE);
    }
    if (moh_class) {
        ast_bridge_channel_write_unhold(bridge_channel);
    }
 
    /*
     * It may be necessary to resume music on hold after we finish
     * playing the announcement.
     */
    if (ast_test_flag(ast_channel_flags(bridge_channel->chan), AST_FLAG_MOH)) {
        const char *latest_musicclass;
 
        ast_channel_lock(bridge_channel->chan);
        latest_musicclass = ast_strdupa(ast_channel_latest_musicclass(bridge_channel->chan));
        ast_channel_unlock(bridge_channel->chan);
        ast_moh_start(bridge_channel->chan, latest_musicclass, NULL);
    }
}
 
struct bridge_playfile {
    /*! Call this function to play the playfile. (NULL if normal sound file to play) */
    ast_bridge_custom_play_fn custom_play;
    /*! Offset into playfile[] where the MOH class name starts.  (zero if no MOH)*/
    int moh_offset;
    /*! Filename to play. */
    char playfile[0];
};
 
/*!
 * \internal
 * \brief Handle the playfile bridge action.
 * \since 12.0.0
 *
 * \param bridge_channel Which channel to play a file on.
 * \param payload Action frame payload to play a file.
 */
static void bridge_channel_playfile(struct ast_bridge_channel *bridge_channel, struct bridge_playfile *payload)
{
    ast_bridge_channel_playfile(bridge_channel, payload->custom_play, payload->playfile,
        payload->moh_offset ? &payload->playfile[payload->moh_offset] : NULL);
}
 
/*!
 * \internal
 * \brief Marshal a file to be played on a bridge_channel
 */
static int payload_helper_playfile(ast_bridge_channel_post_action_data post_it,
    struct ast_bridge_channel *bridge_channel, ast_bridge_custom_play_fn custom_play, const char *playfile, const char *moh_class)
{
    struct bridge_playfile *payload;
    size_t len_name = strlen(playfile) + 1;
    size_t len_moh = !moh_class ? 0 : strlen(moh_class) + 1;
    size_t len_payload = sizeof(*payload) + len_name + len_moh;
 
    /* Fill in play file frame data. */
    payload = ast_alloca(len_payload);
    payload->custom_play = custom_play;
    payload->moh_offset = len_moh ? len_name : 0;
    strcpy(payload->playfile, playfile);/* Safe */
    if (moh_class) {
        strcpy(&payload->playfile[payload->moh_offset], moh_class);/* Safe */
    }
 
    return post_it(bridge_channel, BRIDGE_CHANNEL_ACTION_PLAY_FILE, payload, len_payload);
}
 
int ast_bridge_channel_write_playfile(struct ast_bridge_channel *bridge_channel, ast_bridge_custom_play_fn custom_play, const char *playfile, const char *moh_class)
{
    return payload_helper_playfile(bridge_channel_write_action_data,
        bridge_channel, custom_play, playfile, moh_class);
}
 
int ast_bridge_channel_queue_playfile(struct ast_bridge_channel *bridge_channel, ast_bridge_custom_play_fn custom_play, const char *playfile, const char *moh_class)
{
    return payload_helper_playfile(bridge_channel_queue_action_data,
        bridge_channel, custom_play, playfile, moh_class);
}
 
int ast_bridge_channel_queue_playfile_sync(struct ast_bridge_channel *bridge_channel,
        ast_bridge_custom_play_fn custom_play, const char *playfile, const char *moh_class)
{
    return payload_helper_playfile(bridge_channel_queue_action_data_sync,
        bridge_channel, custom_play, playfile, moh_class);
}
 
struct bridge_custom_callback {
    /*! Call this function on the bridge channel thread. */
    ast_bridge_custom_callback_fn callback;
    /*! Size of the payload if it exists.  A number otherwise. */
    size_t payload_size;
    /*! Option flags determining how callback is called. */
    unsigned int flags;
    /*! Nonzero if the payload exists. */
    char payload_exists;
    /*! Payload to give to callback. */
    char payload[0];
};
 
/*!
 * \internal
 * \brief Handle the do custom callback bridge action.
 * \since 12.0.0
 *
 * \param bridge_channel Which channel to call the callback on.
 * \param data Action frame data to call the callback.
 */
static void bridge_channel_do_callback(struct ast_bridge_channel *bridge_channel, struct bridge_custom_callback *data)
{
    if (ast_test_flag(data, AST_BRIDGE_CHANNEL_CB_OPTION_MEDIA)) {
        bridge_channel_suspend(bridge_channel);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
    }
    data->callback(bridge_channel, data->payload_exists ? data->payload : NULL, data->payload_size);
    if (ast_test_flag(data, AST_BRIDGE_CHANNEL_CB_OPTION_MEDIA)) {
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_unsuspend(bridge_channel);
    }
}
 
/*!
 * \internal
 * \brief Marshal a custom callback function to be called on a bridge_channel
 */
static int payload_helper_cb(ast_bridge_channel_post_action_data post_it,
    struct ast_bridge_channel *bridge_channel,
    enum ast_bridge_channel_custom_callback_option flags,
    ast_bridge_custom_callback_fn callback, const void *payload, size_t payload_size)
{
    struct bridge_custom_callback *cb_data;
    size_t len_data = sizeof(*cb_data) + (payload ? payload_size : 0);
 
    /* Sanity check. */
    if (!callback) {
        ast_assert(0);
        return -1;
    }
 
    /* Fill in custom callback frame data. */
    cb_data = alloca(len_data);
    cb_data->callback = callback;
    cb_data->payload_size = payload_size;
    cb_data->flags = flags;
    cb_data->payload_exists = payload && payload_size;
    if (cb_data->payload_exists) {
        memcpy(cb_data->payload, payload, payload_size);/* Safe */
    }
 
    return post_it(bridge_channel, BRIDGE_CHANNEL_ACTION_CALLBACK, cb_data, len_data);
}
 
int ast_bridge_channel_write_callback(struct ast_bridge_channel *bridge_channel,
    enum ast_bridge_channel_custom_callback_option flags,
    ast_bridge_custom_callback_fn callback, const void *payload, size_t payload_size)
{
    return payload_helper_cb(bridge_channel_write_action_data,
        bridge_channel, flags, callback, payload, payload_size);
}
 
int ast_bridge_channel_queue_callback(struct ast_bridge_channel *bridge_channel,
    enum ast_bridge_channel_custom_callback_option flags,
    ast_bridge_custom_callback_fn callback, const void *payload, size_t payload_size)
{
    return payload_helper_cb(bridge_channel_queue_action_data,
        bridge_channel, flags, callback, payload, payload_size);
}
 
struct bridge_park {
    int parker_uuid_offset;
    int app_data_offset;
    /* buffer used for holding those strings */
    char parkee_uuid[0];
};
 
/*!
 * \internal
 * \brief Park a bridge_cahnnel
 */
static void bridge_channel_park(struct ast_bridge_channel *bridge_channel, struct bridge_park *payload)
{
    if (!ast_parking_provider_registered()) {
        ast_log(AST_LOG_WARNING, "Unable to park %s: No parking provider loaded!\n",
            ast_channel_name(bridge_channel->chan));
        return;
    }
 
    if (ast_parking_park_bridge_channel(bridge_channel, payload->parkee_uuid,
        &payload->parkee_uuid[payload->parker_uuid_offset],
        payload->app_data_offset ? &payload->parkee_uuid[payload->app_data_offset] : NULL)) {
        ast_log(AST_LOG_WARNING, "Error occurred while parking %s\n",
            ast_channel_name(bridge_channel->chan));
    }
}
 
/*!
 * \internal
 * \brief Marshal a park action onto a bridge_channel
 */
static int payload_helper_park(ast_bridge_channel_post_action_data post_it,
    struct ast_bridge_channel *bridge_channel,
    const char *parkee_uuid,
    const char *parker_uuid,
    const char *app_data)
{
    struct bridge_park *payload;
    size_t len_parkee_uuid = strlen(parkee_uuid) + 1;
    size_t len_parker_uuid = strlen(parker_uuid) + 1;
    size_t len_app_data = !app_data ? 0 : strlen(app_data) + 1;
    size_t len_payload = sizeof(*payload) + len_parker_uuid + len_parkee_uuid + len_app_data;
 
    payload = alloca(len_payload);
    payload->app_data_offset = len_app_data ? len_parkee_uuid + len_parker_uuid : 0;
    payload->parker_uuid_offset = len_parkee_uuid;
    strcpy(payload->parkee_uuid, parkee_uuid);
    strcpy(&payload->parkee_uuid[payload->parker_uuid_offset], parker_uuid);
    if (app_data) {
        strcpy(&payload->parkee_uuid[payload->app_data_offset], app_data);
    }
 
    return post_it(bridge_channel, BRIDGE_CHANNEL_ACTION_PARK, payload, len_payload);
}
 
int ast_bridge_channel_write_park(struct ast_bridge_channel *bridge_channel, const char *parkee_uuid, const char *parker_uuid, const char *app_data)
{
    return payload_helper_park(bridge_channel_write_action_data,
        bridge_channel, parkee_uuid, parker_uuid, app_data);
}
 
/*!
 * \internal
 * \brief Handle bridge channel interval expiration.
 * \since 12.0.0
 *
 * \param bridge_channel Channel to run expired intervals on.
 */
static void bridge_channel_handle_interval(struct ast_bridge_channel *bridge_channel)
{
    struct ast_heap *interval_hooks;
    struct ast_bridge_hook_timer *hook;
    struct timeval start;
    int chan_suspended = 0;
 
    interval_hooks = bridge_channel->features->interval_hooks;
    ast_heap_wrlock(interval_hooks);
    start = ast_tvnow();
    while ((hook = ast_heap_peek(interval_hooks, 1))) {
        int interval;
        unsigned int execution_time;
 
        if (ast_tvdiff_ms(hook->timer.trip_time, start) > 0) {
            ast_debug(1, "Hook %p on %p(%s) wants to happen in the future, stopping our traversal\n",
                hook, bridge_channel, ast_channel_name(bridge_channel->chan));
            break;
        }
        ao2_ref(hook, +1);
        ast_heap_unlock(interval_hooks);
 
        if (!chan_suspended
            && ast_test_flag(&hook->timer, AST_BRIDGE_HOOK_TIMER_OPTION_MEDIA)) {
            chan_suspended = 1;
            bridge_channel_suspend(bridge_channel);
            ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        }
 
        ast_debug(1, "Executing hook %p on %p(%s)\n",
            hook, bridge_channel, ast_channel_name(bridge_channel->chan));
        interval = hook->generic.callback(bridge_channel, hook->generic.hook_pvt);
 
        ast_heap_wrlock(interval_hooks);
        if (ast_heap_peek(interval_hooks, hook->timer.heap_index) != hook
            || !ast_heap_remove(interval_hooks, hook)) {
            /* Interval hook is already removed from the bridge_channel. */
            ao2_ref(hook, -1);
            continue;
        }
        ao2_ref(hook, -1);
 
        if (interval < 0) {
            ast_debug(1, "Removed interval hook %p from %p(%s)\n",
                hook, bridge_channel, ast_channel_name(bridge_channel->chan));
            ao2_ref(hook, -1);
            continue;
        }
        if (interval) {
            /* Set new interval for the hook. */
            hook->timer.interval = interval;
        }
 
        ast_debug(1, "Updating interval hook %p with interval %u on %p(%s)\n",
            hook, hook->timer.interval, bridge_channel,
            ast_channel_name(bridge_channel->chan));
 
        /* resetting start */
        start = ast_tvnow();
 
        /*
         * Resetup the interval hook for the next interval.  We may need
         * to skip over any missed intervals because the hook was
         * delayed or took too long.
         */
        execution_time = ast_tvdiff_ms(start, hook->timer.trip_time);
        while (hook->timer.interval < execution_time) {
            execution_time -= hook->timer.interval;
        }
        hook->timer.trip_time = ast_tvadd(start, ast_samp2tv(hook->timer.interval - execution_time, 1000));
        hook->timer.seqno = ast_atomic_fetchadd_int((int *) &bridge_channel->features->interval_sequence, +1);
 
        if (ast_heap_push(interval_hooks, hook)) {
            /* Could not push the hook back onto the heap. */
            ao2_ref(hook, -1);
        }
    }
    ast_heap_unlock(interval_hooks);
 
    if (chan_suspended) {
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_unsuspend(bridge_channel);
    }
}
 
/*!
 * \internal
 * \brief Write a DTMF stream out to a channel
 */
static int bridge_channel_write_dtmf_stream(struct ast_bridge_channel *bridge_channel, const char *dtmf)
{
    return bridge_channel_write_action_data(bridge_channel,
        BRIDGE_CHANNEL_ACTION_DTMF_STREAM, dtmf, strlen(dtmf) + 1);
}
 
/*!
 * \internal
 * \brief Indicate to the testsuite a feature was successfully detected.
 *
 * Currently, this function only will relay built-in features to the testsuite,
 * but it could be modified to detect applicationmap items should the need arise.
 *
 * \param chan The channel that activated the feature
 * \param dtmf The DTMF sequence entered to activate the feature
 */
static void testsuite_notify_feature_success(struct ast_channel *chan, const char *dtmf)
{
#ifdef TEST_FRAMEWORK
    char *feature = "unknown";
    struct ast_featuremap_config *featuremap;
    struct ast_features_xfer_config *xfer;
 
    ast_channel_lock(chan);
    featuremap = ast_get_chan_featuremap_config(chan);
    xfer = ast_get_chan_features_xfer_config(chan);
    ast_channel_unlock(chan);
 
    if (featuremap) {
        if (!strcmp(dtmf, featuremap->blindxfer)) {
            feature = "blindxfer";
        } else if (!strcmp(dtmf, featuremap->atxfer)) {
            feature = "atxfer";
        } else if (!strcmp(dtmf, featuremap->disconnect)) {
            feature = "disconnect";
        } else if (!strcmp(dtmf, featuremap->automixmon)) {
            feature = "automixmon";
        } else if (!strcmp(dtmf, featuremap->parkcall)) {
            feature = "parkcall";
        }
    }
    if (xfer) {
        if (!strcmp(dtmf, xfer->atxferthreeway)) {
            feature = "atxferthreeway";
        }
    }
 
    ao2_cleanup(featuremap);
    ao2_cleanup(xfer);
 
    ast_test_suite_event_notify("FEATURE_DETECTION",
            "Result: success\r\n"
            "Feature: %s", feature);
#endif /* TEST_FRAMEWORK */
}
 
static int bridge_channel_feature_digit_add(
    struct ast_bridge_channel *bridge_channel, int digit, size_t dtmf_len)
{
    if (dtmf_len < ARRAY_LEN(bridge_channel->dtmf_hook_state.collected) - 1) {
        /* Add the new digit to the DTMF string so we can do our matching */
        bridge_channel->dtmf_hook_state.collected[dtmf_len++] = digit;
        bridge_channel->dtmf_hook_state.collected[dtmf_len] = '\0';
 
        ast_debug(1, "DTMF feature string on %p(%s) is now '%s'\n",
              bridge_channel, ast_channel_name(bridge_channel->chan),
              bridge_channel->dtmf_hook_state.collected);
    }
 
    return dtmf_len;
}
 
static unsigned int bridge_channel_feature_digit_timeout(struct ast_bridge_channel *bridge_channel)
{
    unsigned int digit_timeout;
    struct ast_features_general_config *gen_cfg;
 
    /* Determine interdigit timeout */
    ast_channel_lock(bridge_channel->chan);
    gen_cfg = ast_get_chan_features_general_config(bridge_channel->chan);
    ast_channel_unlock(bridge_channel->chan);
 
    if (!gen_cfg) {
        ast_log(LOG_ERROR, "Unable to retrieve features configuration.\n");
        return 3000; /* Pick a reasonable failsafe timeout in ms */
    }
 
    digit_timeout = gen_cfg->featuredigittimeout;
    ao2_ref(gen_cfg, -1);
 
    return digit_timeout;
}
 
void ast_bridge_channel_feature_digit_add(struct ast_bridge_channel *bridge_channel, int digit)
{
    if (digit) {
        bridge_channel_feature_digit_add(
            bridge_channel, digit, strlen(bridge_channel->dtmf_hook_state.collected));
    }
}
 
void ast_bridge_channel_feature_digit(struct ast_bridge_channel *bridge_channel, int digit)
{
    struct ast_bridge_features *features = bridge_channel->features;
    struct ast_bridge_hook_dtmf *hook = NULL;
    size_t dtmf_len;
 
    struct sanity_check_of_dtmf_size {
        char check[1 / (ARRAY_LEN(bridge_channel->dtmf_hook_state.collected) == ARRAY_LEN(hook->dtmf.code))];
    };
 
    dtmf_len = strlen(bridge_channel->dtmf_hook_state.collected);
    if (!dtmf_len && !digit) {
        /* Nothing to do */
        return;
    }
 
    if (digit) {
        dtmf_len = bridge_channel_feature_digit_add(bridge_channel, digit, dtmf_len);
    }
 
    while (digit) {
        /* See if a DTMF feature hook matches or can match */
        hook = ao2_find(features->dtmf_hooks, bridge_channel->dtmf_hook_state.collected,
            OBJ_SEARCH_PARTIAL_KEY);
        if (!hook) {
            ast_debug(1, "No DTMF feature hooks on %p(%s) match '%s'\n",
                bridge_channel, ast_channel_name(bridge_channel->chan),
                bridge_channel->dtmf_hook_state.collected);
            break;
        } else if (dtmf_len != strlen(hook->dtmf.code)) {
            unsigned int digit_timeout;
            /* Need more digits to match */
            ao2_ref(hook, -1);
            digit_timeout = bridge_channel_feature_digit_timeout(bridge_channel);
            bridge_channel->dtmf_hook_state.interdigit_timeout =
                ast_tvadd(ast_tvnow(), ast_samp2tv(digit_timeout, 1000));
            return;
        } else {
            int remove_me;
            int already_suspended;
 
            ast_debug(1, "DTMF feature hook %p matched DTMF string '%s' on %p(%s)\n",
                hook, bridge_channel->dtmf_hook_state.collected, bridge_channel,
                ast_channel_name(bridge_channel->chan));
 
            /*
             * Clear the collected digits before executing the hook
             * in case the hook starts another sequence.
             */
            bridge_channel->dtmf_hook_state.collected[0] = '\0';
 
            ast_bridge_channel_lock_bridge(bridge_channel);
            already_suspended = bridge_channel->suspended;
            if (!already_suspended) {
                bridge_channel_internal_suspend_nolock(bridge_channel);
            }
            ast_bridge_unlock(bridge_channel->bridge);
            ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
 
            /* Execute the matched hook on this channel. */
            remove_me = hook->generic.callback(bridge_channel, hook->generic.hook_pvt);
            if (remove_me) {
                ast_debug(1, "DTMF hook %p is being removed from %p(%s)\n",
                    hook, bridge_channel, ast_channel_name(bridge_channel->chan));
                ao2_unlink(features->dtmf_hooks, hook);
            }
            testsuite_notify_feature_success(bridge_channel->chan, hook->dtmf.code);
            ao2_ref(hook, -1);
 
            ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
            if (!already_suspended) {
                bridge_channel_unsuspend(bridge_channel);
            }
 
            /*
             * If we are handing the channel off to an external hook for
             * ownership, we are not guaranteed what kind of state it will
             * come back in.  If the channel hungup, we need to detect that
             * here if the hook did not already change the state.
             */
            if (bridge_channel->chan && ast_check_hangup_locked(bridge_channel->chan)) {
                ast_bridge_channel_kick(bridge_channel, 0);
                bridge_channel->dtmf_hook_state.collected[0] = '\0';
                return;
            }
 
            /* if there is dtmf that has been collected then loop back through,
               but set digit to -1 so it doesn't try to do an add since the dtmf
               is already in the buffer */
            dtmf_len = strlen(bridge_channel->dtmf_hook_state.collected);
            if (!dtmf_len) {
                return;
            }
        }
    }
 
    if (!digit) {
        ast_debug(1, "DTMF feature string collection on %p(%s) timed out\n",
            bridge_channel, ast_channel_name(bridge_channel->chan));
    }
 
    /* Timeout or DTMF digit didn't allow a match with any hooks. */
    if (features->dtmf_passthrough) {
        /* Stream the collected DTMF to the other channels. */
        bridge_channel_write_dtmf_stream(bridge_channel,
            bridge_channel->dtmf_hook_state.collected);
    }
    bridge_channel->dtmf_hook_state.collected[0] = '\0';
 
    ast_test_suite_event_notify("FEATURE_DETECTION", "Result: fail");
}
 
/*!
 * \internal
 * \brief Handle bridge channel DTMF feature timeout expiration.
 * \since 12.8.0
 *
 * \param bridge_channel Channel to check expired interdigit timer on.
 */
static void bridge_channel_handle_feature_timeout(struct ast_bridge_channel *bridge_channel)
{
    if (!bridge_channel->dtmf_hook_state.collected[0]
        || 0 < ast_tvdiff_ms(bridge_channel->dtmf_hook_state.interdigit_timeout,
            ast_tvnow())) {
        /* Not within a sequence or not timed out. */
        return;
    }
 
    ast_bridge_channel_feature_digit(bridge_channel, 0);
}
 
/*!
 * \internal
 * \brief Indicate that a bridge_channel is talking
 */
static void bridge_channel_talking(struct ast_bridge_channel *bridge_channel, int talking)
{
    struct ast_bridge_features *features = bridge_channel->features;
    struct ast_bridge_hook *hook;
    struct ao2_iterator iter;
 
    /* Run any talk detection hooks. */
    iter = ao2_iterator_init(features->other_hooks, 0);
    for (; (hook = ao2_iterator_next(&iter)); ao2_ref(hook, -1)) {
        int remove_me;
        ast_bridge_talking_indicate_callback talk_cb;
 
        if (hook->type != AST_BRIDGE_HOOK_TYPE_TALK) {
            continue;
        }
        talk_cb = (ast_bridge_talking_indicate_callback) hook->callback;
        remove_me = talk_cb(bridge_channel, hook->hook_pvt, talking);
        if (remove_me) {
            ast_debug(1, "Talk detection hook %p is being removed from %p(%s)\n",
                hook, bridge_channel, ast_channel_name(bridge_channel->chan));
            ao2_unlink(features->other_hooks, hook);
        }
    }
    ao2_iterator_destroy(&iter);
}
 
/*!
 * \internal
 * \brief Play back DTMF on a bridge channel
 */
static void bridge_channel_dtmf_stream(struct ast_bridge_channel *bridge_channel, const char *dtmf)
{
    ast_debug(1, "Playing DTMF stream '%s' out to %p(%s)\n",
        dtmf, bridge_channel, ast_channel_name(bridge_channel->chan));
    ast_dtmf_stream(bridge_channel->chan, NULL, dtmf, 0, 0);
}
 
/*! \brief Data specifying where a blind transfer is going to */
struct blind_transfer_data {
    char exten[AST_MAX_EXTENSION];
    char context[AST_MAX_CONTEXT];
};
 
/*!
 * \internal
 * \brief Execute after bridge actions on a channel when it leaves a bridge
 */
static void after_bridge_move_channel(struct ast_channel *chan_bridged, void *data)
{
    RAII_VAR(struct ast_channel *, chan_target, data, ao2_cleanup);
    struct ast_party_connected_line connected_target;
    unsigned char connected_line_data[1024];
    int payload_size;
 
    ast_party_connected_line_init(&connected_target);
 
    ast_channel_lock(chan_target);
    ast_party_connected_line_copy(&connected_target, ast_channel_connected(chan_target));
    ast_channel_unlock(chan_target);
    ast_party_id_reset(&connected_target.priv);
 
    if (ast_channel_move(chan_target, chan_bridged)) {
        ast_softhangup(chan_target, AST_SOFTHANGUP_DEV);
        ast_party_connected_line_free(&connected_target);
        return;
    }
 
    /* The ast_channel_move function will end up updating the connected line information
     * on chan_target to the value we have here, but will not inform it. To ensure that
     * AST_FRAME_READ_ACTION_CONNECTED_LINE_MACRO is executed we wipe it away here. If
     * we don't do this then the change will be considered redundant, since the connected
     * line information is already there (despite the channel not being told).
     */
    ast_channel_lock(chan_target);
    ast_party_connected_line_free(ast_channel_connected_indicated(chan_target));
    ast_party_connected_line_init(ast_channel_connected_indicated(chan_target));
    ast_channel_unlock(chan_target);
 
    if ((payload_size = ast_connected_line_build_data(connected_line_data,
        sizeof(connected_line_data), &connected_target, NULL)) != -1) {
        struct ast_control_read_action_payload *frame_payload;
        int frame_size;
 
        frame_size = payload_size + sizeof(*frame_payload);
        frame_payload = ast_alloca(frame_size);
        frame_payload->action = AST_FRAME_READ_ACTION_CONNECTED_LINE_MACRO;
        frame_payload->payload_size = payload_size;
        memcpy(frame_payload->payload, connected_line_data, payload_size);
        ast_queue_control_data(chan_target, AST_CONTROL_READ_ACTION, frame_payload, frame_size);
    }
 
    /* A connected line update is queued so that if chan_target is remotely involved with
     * anything (such as dialing a channel) the other channel(s) will be informed of the
     * new channel they are involved with.
     */
    ast_channel_lock(chan_target);
    ast_connected_line_copy_from_caller(&connected_target, ast_channel_caller(chan_target));
    ast_channel_queue_connected_line_update(chan_target, &connected_target, NULL);
    ast_channel_unlock(chan_target);
 
    ast_party_connected_line_free(&connected_target);
}
 
/*!
 * \internal
 * \brief Execute logic to cleanup when after bridge fails
 */
static void after_bridge_move_channel_fail(enum ast_bridge_after_cb_reason reason, void *data)
{
    RAII_VAR(struct ast_channel *, chan_target, data, ao2_cleanup);
 
    ast_log(LOG_WARNING, "Unable to complete transfer: %s\n",
        ast_bridge_after_cb_reason_string(reason));
    ast_softhangup(chan_target, AST_SOFTHANGUP_DEV);
}
 
/*!
 * \internal
 * \brief Perform a blind transfer on a channel in a bridge
 */
static void bridge_channel_blind_transfer(struct ast_bridge_channel *bridge_channel,
        struct blind_transfer_data *blind_data)
{
    ast_async_goto(bridge_channel->chan, blind_data->context, blind_data->exten, 1);
    ast_bridge_channel_kick(bridge_channel, AST_CAUSE_NORMAL_CLEARING);
}
 
/*!
 * \internal
 * \brief Perform an attended transfer on a channel in a bridge
 */
static void bridge_channel_attended_transfer(struct ast_bridge_channel *bridge_channel,
        const char *target_chan_name)
{
    RAII_VAR(struct ast_channel *, chan_target, NULL, ao2_cleanup);
    RAII_VAR(struct ast_channel *, chan_bridged, NULL, ao2_cleanup);
 
    chan_target = ast_channel_get_by_name(target_chan_name);
    if (!chan_target) {
        /* Dang, it disappeared somehow */
        ast_bridge_channel_kick(bridge_channel, AST_CAUSE_NORMAL_CLEARING);
        return;
    }
 
    ast_bridge_channel_lock(bridge_channel);
    chan_bridged = bridge_channel->chan;
    ast_assert(chan_bridged != NULL);
    ao2_ref(chan_bridged, +1);
    ast_bridge_channel_unlock(bridge_channel);
 
    if (ast_bridge_set_after_callback(chan_bridged, after_bridge_move_channel,
        after_bridge_move_channel_fail, ast_channel_ref(chan_target))) {
        ast_softhangup(chan_target, AST_SOFTHANGUP_DEV);
 
        /* Release the ref we tried to pass to ast_bridge_set_after_callback(). */
        ast_channel_unref(chan_target);
    }
    ast_bridge_channel_kick(bridge_channel, AST_CAUSE_NORMAL_CLEARING);
}
 
/*!
 * \internal
 * \brief Handle bridge channel bridge action frame.
 * \since 12.0.0
 *
 * \param bridge_channel Channel to execute the action on.
 * \param action What to do.
 * \param data data from the action.
 */
static void bridge_channel_handle_action(struct ast_bridge_channel *bridge_channel,
    enum bridge_channel_action_type action, void *data)
{
    switch (action) {
    case BRIDGE_CHANNEL_ACTION_DTMF_STREAM:
        bridge_channel_suspend(bridge_channel);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_dtmf_stream(bridge_channel, data);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_unsuspend(bridge_channel);
        break;
    case BRIDGE_CHANNEL_ACTION_TALKING_START:
    case BRIDGE_CHANNEL_ACTION_TALKING_STOP:
        bridge_channel_talking(bridge_channel,
            action == BRIDGE_CHANNEL_ACTION_TALKING_START);
        break;
    case BRIDGE_CHANNEL_ACTION_PLAY_FILE:
        bridge_channel_suspend(bridge_channel);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_playfile(bridge_channel, data);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_unsuspend(bridge_channel);
        break;
    case BRIDGE_CHANNEL_ACTION_RUN_APP:
        bridge_channel_suspend(bridge_channel);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_run_app(bridge_channel, data);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_unsuspend(bridge_channel);
        break;
    case BRIDGE_CHANNEL_ACTION_CALLBACK:
        bridge_channel_do_callback(bridge_channel, data);
        break;
    case BRIDGE_CHANNEL_ACTION_PARK:
        bridge_channel_suspend(bridge_channel);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_park(bridge_channel, data);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_unsuspend(bridge_channel);
        break;
    case BRIDGE_CHANNEL_ACTION_BLIND_TRANSFER:
        bridge_channel_blind_transfer(bridge_channel, data);
        break;
    case BRIDGE_CHANNEL_ACTION_ATTENDED_TRANSFER:
        bridge_channel_attended_transfer(bridge_channel, data);
        break;
    default:
        break;
    }
 
    /* While invoking an action it is possible for the channel to be hung up. So
     * that the bridge respects this we check here and if hung up kick it out.
     */
    if (bridge_channel->chan && ast_check_hangup_locked(bridge_channel->chan)) {
        ast_bridge_channel_kick(bridge_channel, 0);
    }
}
 
/*!
 * \internal
 * \brief Check if a bridge should dissolve and do it.
 * \since 12.0.0
 *
 * \param bridge_channel Channel causing the check.
 *
 * \note On entry, bridge_channel->bridge is already locked.
 */
static void bridge_channel_dissolve_check(struct ast_bridge_channel *bridge_channel)
{
    struct ast_bridge *bridge = bridge_channel->bridge;
 
    if (bridge->dissolved) {
        return;
    }
 
    if (!bridge->num_channels
        && ast_test_flag(&bridge->feature_flags, AST_BRIDGE_FLAG_DISSOLVE_EMPTY)) {
        /* Last channel leaving the bridge turns off the lights. */
        bridge_dissolve(bridge, ast_channel_hangupcause(bridge_channel->chan));
        return;
    }
 
    switch (bridge_channel->state) {
    case BRIDGE_CHANNEL_STATE_END:
        /* Do we need to dissolve the bridge because this channel hung up? */
        if (ast_test_flag(&bridge->feature_flags, AST_BRIDGE_FLAG_DISSOLVE_HANGUP)
            || (bridge_channel->features->usable
                && ast_test_flag(&bridge_channel->features->feature_flags,
                    AST_BRIDGE_CHANNEL_FLAG_DISSOLVE_HANGUP))) {
            bridge_dissolve(bridge, ast_channel_hangupcause(bridge_channel->chan));
            return;
        }
        break;
    default:
        break;
    }
 
    if (bridge->num_lonely && bridge->num_lonely == bridge->num_channels) {
        /*
         * This will start a chain reaction where each channel leaving
         * enters this function and causes the next to leave as long as
         * there aren't non-lonely channels in the bridge.
         */
        ast_bridge_channel_leave_bridge(AST_LIST_FIRST(&bridge->channels),
            BRIDGE_CHANNEL_STATE_END_NO_DISSOLVE,
            ast_channel_hangupcause(bridge_channel->chan));
    }
}
 
void bridge_channel_internal_pull(struct ast_bridge_channel *bridge_channel)
{
    struct ast_bridge *bridge = bridge_channel->bridge;
 
    if (!bridge_channel->in_bridge) {
        return;
    }
    bridge_channel->in_bridge = 0;
 
    ast_debug(1, "Bridge %s: pulling %p(%s)\n",
        bridge->uniqueid, bridge_channel, ast_channel_name(bridge_channel->chan));
 
    ast_verb(3, "Channel %s left '%s' %s-bridge <%s>\n",
        ast_channel_name(bridge_channel->chan),
        bridge->technology->name,
        bridge->v_table->name,
        bridge->uniqueid);
 
    if (!bridge_channel->just_joined) {
        /* Tell the bridge technology we are leaving so they tear us down */
        ast_debug(1, "Bridge %s: %p(%s) is leaving %s technology\n",
            bridge->uniqueid, bridge_channel, ast_channel_name(bridge_channel->chan),
            bridge->technology->name);
        if (bridge->technology->leave) {
            bridge->technology->leave(bridge, bridge_channel);
        }
    }
 
    /* Remove channel from the bridge */
    if (!bridge_channel->suspended) {
        --bridge->num_active;
    }
    if (ast_test_flag(&bridge_channel->features->feature_flags, AST_BRIDGE_CHANNEL_FLAG_LONELY)) {
        --bridge->num_lonely;
    }
    --bridge->num_channels;
    AST_LIST_REMOVE(&bridge->channels, bridge_channel, entry);
 
    bridge_channel_dissolve_check(bridge_channel);
    bridge->v_table->pull(bridge, bridge_channel);
 
    ast_bridge_channel_clear_roles(bridge_channel);
 
    /* If we are not going to be hung up after leaving a bridge, and we were an
     * outgoing channel, clear the outgoing flag.
     */
    if (ast_test_flag(ast_channel_flags(bridge_channel->chan), AST_FLAG_OUTGOING)
        && (ast_channel_is_leaving_bridge(bridge_channel->chan)
            || bridge_channel->state == BRIDGE_CHANNEL_STATE_WAIT)) {
        ast_debug(2, "Channel %s will survive this bridge; clearing outgoing (dialed) flag\n", ast_channel_name(bridge_channel->chan));
        ast_channel_clear_flag(bridge_channel->chan, AST_FLAG_OUTGOING);
    }
 
    bridge->reconfigured = 1;
    ast_bridge_publish_leave(bridge, bridge_channel->chan);
}
 
int bridge_channel_internal_push_full(struct ast_bridge_channel *bridge_channel, int optimized)
{
    struct ast_bridge *bridge = bridge_channel->bridge;
    struct ast_bridge_channel *swap;
 
    ast_assert(!bridge_channel->in_bridge);
 
    swap = bridge_find_channel(bridge, bridge_channel->swap);
    bridge_channel->swap = NULL;
 
    if (swap) {
        ast_debug(1, "Bridge %s: pushing %p(%s) by swapping with %p(%s)\n",
            bridge->uniqueid, bridge_channel, ast_channel_name(bridge_channel->chan),
            swap, ast_channel_name(swap->chan));
    } else {
        ast_debug(1, "Bridge %s: pushing %p(%s)\n",
            bridge->uniqueid, bridge_channel, ast_channel_name(bridge_channel->chan));
    }
 
    /* Add channel to the bridge */
    if (bridge->dissolved
        || bridge_channel->state != BRIDGE_CHANNEL_STATE_WAIT
        || (swap && swap->state != BRIDGE_CHANNEL_STATE_WAIT)
        || bridge->v_table->push(bridge, bridge_channel, swap)) {
        ast_debug(1, "Bridge %s: pushing %p(%s) into bridge failed\n",
            bridge->uniqueid, bridge_channel, ast_channel_name(bridge_channel->chan));
        return -1;
    }
 
    ast_bridge_channel_establish_roles(bridge_channel);
 
    if (swap) {
        int dissolve = ast_test_flag(&bridge->feature_flags, AST_BRIDGE_FLAG_DISSOLVE_EMPTY);
 
        /* This flag is cleared so the act of this channel leaving does not cause it to dissolve if need be */
        ast_clear_flag(&bridge->feature_flags, AST_BRIDGE_FLAG_DISSOLVE_EMPTY);
 
        if (optimized) {
            bridge_channel_cancel_owed_events(swap);
        }
        ast_bridge_channel_leave_bridge(swap, BRIDGE_CHANNEL_STATE_END_NO_DISSOLVE, 0);
        bridge_channel_internal_pull(swap);
 
        ast_set2_flag(&bridge->feature_flags, dissolve, AST_BRIDGE_FLAG_DISSOLVE_EMPTY);
    }
 
    bridge_channel->in_bridge = 1;
    bridge_channel->just_joined = 1;
    AST_LIST_INSERT_TAIL(&bridge->channels, bridge_channel, entry);
    ++bridge->num_channels;
    if (ast_test_flag(&bridge_channel->features->feature_flags, AST_BRIDGE_CHANNEL_FLAG_LONELY)) {
        ++bridge->num_lonely;
    }
    if (!bridge_channel->suspended) {
        ++bridge->num_active;
    }
 
    ast_verb(3, "Channel %s %s%s%s '%s' %s-bridge <%s>\n",
        ast_channel_name(bridge_channel->chan),
        swap ? "swapped with " : "joined",
        swap ? ast_channel_name(swap->chan) : "",
        swap ? " into" : "",
        bridge->technology->name,
        bridge->v_table->name,
        bridge->uniqueid);
 
    ast_bridge_publish_enter(bridge, bridge_channel->chan, swap ? swap->chan : NULL);
 
    /* Clear any BLINDTRANSFER,ATTENDEDTRANSFER and FORWARDERNAME since the transfer has completed. */
    pbx_builtin_setvar_helper(bridge_channel->chan, "BLINDTRANSFER", NULL);
    pbx_builtin_setvar_helper(bridge_channel->chan, "ATTENDEDTRANSFER", NULL);
    pbx_builtin_setvar_helper(bridge_channel->chan, "FORWARDERNAME", NULL);
 
    /* Wake up the bridge channel thread to reevaluate any interval timers. */
    ast_queue_frame(bridge_channel->chan, &ast_null_frame);
 
    bridge->reconfigured = 1;
    return 0;
}
 
int bridge_channel_internal_push(struct ast_bridge_channel *bridge_channel)
{
    return bridge_channel_internal_push_full(bridge_channel, 0);
}
 
/*!
 * \internal
 * \brief Handle bridge channel control frame action.
 * \since 12.0.0
 *
 * \param bridge_channel Channel to execute the control frame action on.
 * \param fr Control frame to handle.
 */
static void bridge_channel_handle_control(struct ast_bridge_channel *bridge_channel, struct ast_frame *fr)
{
    struct ast_channel *chan;
    struct ast_option_header *aoh;
 
    chan = bridge_channel->chan;
    switch (fr->subclass.integer) {
    case AST_CONTROL_REDIRECTING:
        if (ast_channel_redirecting_sub(NULL, chan, fr, 1)) {
            ast_indicate_data(chan, fr->subclass.integer, fr->data.ptr, fr->datalen);
        }
        break;
    case AST_CONTROL_CONNECTED_LINE:
        if (ast_channel_connected_line_sub(NULL, chan, fr, 1)) {
            ast_indicate_data(chan, fr->subclass.integer, fr->data.ptr, fr->datalen);
        }
        break;
    case AST_CONTROL_OPTION:
        /*
         * Forward option Requests, but only ones we know are safe These
         * are ONLY sent by chan_iax2 and I'm not convinced that they
         * are useful. I haven't deleted them entirely because I just am
         * not sure of the ramifications of removing them.
         */
        aoh = fr->data.ptr;
        if (aoh && aoh->flag == AST_OPTION_FLAG_REQUEST) {
            switch (ntohs(aoh->option)) {
            case AST_OPTION_TONE_VERIFY:
            case AST_OPTION_TDD:
            case AST_OPTION_RELAXDTMF:
            case AST_OPTION_AUDIO_MODE:
            case AST_OPTION_DIGIT_DETECT:
            case AST_OPTION_FAX_DETECT:
                ast_channel_setoption(chan, ntohs(aoh->option), aoh->data,
                    fr->datalen - sizeof(*aoh), 0);
                break;
            default:
                break;
            }
        }
        break;
    case AST_CONTROL_ANSWER:
        if (ast_channel_state(chan) != AST_STATE_UP) {
            ast_answer(chan);
            ast_bridge_channel_lock_bridge(bridge_channel);
            bridge_channel->bridge->reconfigured = 1;
            bridge_reconfigured(bridge_channel->bridge, 0);
            ast_bridge_unlock(bridge_channel->bridge);
        } else {
            ast_indicate(chan, -1);
        }
        break;
    case AST_CONTROL_MASQUERADE_NOTIFY:
        /* Should never happen. */
        ast_assert(0);
        break;
    case AST_CONTROL_STREAM_TOPOLOGY_CHANGED:
        ast_indicate_data(chan, fr->subclass.integer, fr->data.ptr, fr->datalen);
        break;
    default:
        ast_indicate_data(chan, fr->subclass.integer, fr->data.ptr, fr->datalen);
        break;
    }
}
 
/*!
 * \internal
 * \brief Ensure text data is zero terminated before sending
 *
 * \param chan Channel to send text to
 * \param f The frame containing the text data to send
 */
static void sendtext_safe(struct ast_channel *chan, const struct ast_frame *f)
{
    if (f->datalen) {
        char *text = f->data.ptr;
 
        if (text[f->datalen - 1]) {
            /* Not zero terminated, we need to allocate */
            text = ast_strndup(text, f->datalen);
            if (!text) {
                return;
            }
        }
 
        ast_sendtext(chan, text);
 
        if (text != f->data.ptr) {
            /* Only free if we allocated */
            ast_free(text);
        }
    } else {
        /* Special case if the frame length is zero (although I
         * am not sure this is possible?) */
        ast_sendtext(chan, "");
    }
}
 
/*!
 * \internal
 * \brief Handle bridge channel write frame to channel.
 * \since 12.0.0
 *
 * \param bridge_channel Channel to write outgoing frame.
 */
static void bridge_channel_handle_write(struct ast_bridge_channel *bridge_channel)
{
    struct ast_frame *fr;
    struct sync_payload *sync_payload;
    int num;
    struct ast_msg_data *msg;
 
    ast_bridge_channel_lock(bridge_channel);
 
    /* It's not good to have unbalanced frames and alert_pipe alerts. */
    ast_assert(!AST_LIST_EMPTY(&bridge_channel->wr_queue));
    if (AST_LIST_EMPTY(&bridge_channel->wr_queue)) {
        /* No frame, flush the alert pipe of excess alerts. */
        ast_log(LOG_WARNING, "Weird.  No frame from bridge for %s to process?\n",
            ast_channel_name(bridge_channel->chan));
        ast_alertpipe_read(bridge_channel->alert_pipe);
        ast_bridge_channel_unlock(bridge_channel);
        return;
    }
 
    AST_LIST_TRAVERSE_SAFE_BEGIN(&bridge_channel->wr_queue, fr, frame_list) {
        if (bridge_channel->dtmf_hook_state.collected[0]) {
            switch (fr->frametype) {
            case AST_FRAME_BRIDGE_ACTION:
            case AST_FRAME_BRIDGE_ACTION_SYNC:
                /* Defer processing these frames while DTMF is collected. */
                continue;
            default:
                break;
            }
        }
        ast_alertpipe_read(bridge_channel->alert_pipe);
        AST_LIST_REMOVE_CURRENT(frame_list);
        break;
    }
    AST_LIST_TRAVERSE_SAFE_END;
 
    ast_bridge_channel_unlock(bridge_channel);
 
    if (!fr) {
        /*
         * Wait some to reduce CPU usage from a tight loop
         * without any wait because we only have deferred
         * frames in the wr_queue.
         */
        usleep(1);
        return;
    }
 
    switch (fr->frametype) {
    case AST_FRAME_BRIDGE_ACTION:
        bridge_channel_handle_action(bridge_channel, fr->subclass.integer, fr->data.ptr);
        break;
    case AST_FRAME_BRIDGE_ACTION_SYNC:
        sync_payload = fr->data.ptr;
        bridge_channel_handle_action(bridge_channel, fr->subclass.integer, sync_payload->data);
        break;
    case AST_FRAME_CONTROL:
        bridge_channel_handle_control(bridge_channel, fr);
        break;
    case AST_FRAME_NULL:
        break;
    case AST_FRAME_TEXT:
        ast_debug(1, "Sending TEXT frame to '%s': %*.s\n",
            ast_channel_name(bridge_channel->chan), fr->datalen, (char *)fr->data.ptr);
        sendtext_safe(bridge_channel->chan, fr);
        break;
    case AST_FRAME_TEXT_DATA:
        msg = (struct ast_msg_data *)fr->data.ptr;
        ast_debug(1, "Sending TEXT_DATA frame from '%s' to '%s:%s': %s\n",
            ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_FROM),
            ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_TO),
            ast_channel_name(bridge_channel->chan),
            ast_msg_data_get_attribute(msg, AST_MSG_DATA_ATTR_BODY));
        ast_sendtext_data(bridge_channel->chan, msg);
        break;
    default:
        /* Assume that there is no mapped stream for this */
        num = -1;
 
        if (fr->stream_num > -1) {
            ast_bridge_channel_lock(bridge_channel);
            if (fr->stream_num < (int)AST_VECTOR_SIZE(&bridge_channel->stream_map.to_channel)) {
                num = AST_VECTOR_GET(&bridge_channel->stream_map.to_channel, fr->stream_num);
            }
            ast_bridge_channel_unlock(bridge_channel);
 
            /* If there is no mapped stream after checking the mapping then there is nowhere
             * to write this frame to, so drop it.
             */
            if (num == -1) {
                break;
            }
        }
 
        /* Write the frame to the channel. */
        bridge_channel->activity = BRIDGE_CHANNEL_THREAD_SIMPLE;
        ast_write_stream(bridge_channel->chan, num, fr);
        break;
    }
    bridge_frame_free(fr);
}
 
/*!
 * \internal
 * \brief Handle DTMF from a channel
 */
static struct ast_frame *bridge_handle_dtmf(struct ast_bridge_channel *bridge_channel, struct ast_frame *frame)
{
    struct ast_bridge_features *features = bridge_channel->features;
    struct ast_bridge_hook_dtmf *hook = NULL;
    char dtmf[2];
 
    /*
     * See if we are already matching a DTMF feature hook sequence or
     * if this DTMF matches the beginning of any DTMF feature hooks.
     */
    dtmf[0] = frame->subclass.integer;
    dtmf[1] = '\0';
    if (bridge_channel->dtmf_hook_state.collected[0]
        || (hook = ao2_find(features->dtmf_hooks, dtmf, OBJ_SEARCH_PARTIAL_KEY))) {
        enum ast_frame_type frametype = frame->frametype;
 
        bridge_frame_free(frame);
        frame = NULL;
 
        ao2_cleanup(hook);
 
        switch (frametype) {
        case AST_FRAME_DTMF_BEGIN:
            /* Just eat the frame. */
            break;
        case AST_FRAME_DTMF_END:
            ast_bridge_channel_feature_digit(bridge_channel, dtmf[0]);
            break;
        default:
            /* Unexpected frame type. */
            ast_assert(0);
            break;
        }
#ifdef TEST_FRAMEWORK
    } else if (frame->frametype == AST_FRAME_DTMF_END) {
        /* Only transmit this event on DTMF end or else every DTMF
         * press will result in the event being broadcast twice
         */
        ast_test_suite_event_notify("FEATURE_DETECTION", "Result: fail");
#endif
    }
 
    return frame;
}
 
static const char *controls[] = {
    [AST_CONTROL_RINGING] = "RINGING",
    [AST_CONTROL_PROCEEDING] = "PROCEEDING",
    [AST_CONTROL_PROGRESS] = "PROGRESS",
    [AST_CONTROL_BUSY] = "BUSY",
    [AST_CONTROL_CONGESTION] = "CONGESTION",
    [AST_CONTROL_ANSWER] = "ANSWER",
};
 
/*!
 * \internal
 * \brief Feed notification that a frame is waiting on a channel into the bridging core
 *
 * \param bridge_channel Bridge channel the notification was received on
 */
static void bridge_handle_trip(struct ast_bridge_channel *bridge_channel)
{
    struct ast_frame *frame;
    int blocked;
 
    if (!ast_strlen_zero(ast_channel_call_forward(bridge_channel->chan))) {
        /* TODO If early bridging is ever used by anything other than ARI,
         * it's important that we actually attempt to handle the call forward
         * attempt, as well as expand features on a bridge channel to allow/disallow
         * call forwarding. For now, all we do is raise an event, showing that
         * a call forward is being attempted.
         */
        ast_channel_publish_dial_forward(NULL, bridge_channel->chan, NULL, NULL, "CANCEL",
            ast_channel_call_forward(bridge_channel->chan));
    }
 
    if (bridge_channel->features->mute) {
        frame = ast_read_stream_noaudio(bridge_channel->chan);
    } else {
        frame = ast_read_stream(bridge_channel->chan);
    }
 
    if (!frame) {
        ast_bridge_channel_kick(bridge_channel, 0);
        return;
    }
 
    if (!ast_channel_is_multistream(bridge_channel->chan)) {
        /* This may not be initialized by non-multistream channel drivers */
        frame->stream_num = -1;
    }
 
    switch (frame->frametype) {
    case AST_FRAME_CONTROL:
        switch (frame->subclass.integer) {
        case AST_CONTROL_CONGESTION:
        case AST_CONTROL_BUSY:
            ast_channel_publish_dial(NULL, bridge_channel->chan, NULL, controls[frame->subclass.integer]);
            break;
        case AST_CONTROL_HANGUP:
            ast_bridge_channel_kick(bridge_channel, 0);
            bridge_frame_free(frame);
            return;
        case AST_CONTROL_RINGING:
        case AST_CONTROL_PROGRESS:
        case AST_CONTROL_PROCEEDING:
        case AST_CONTROL_ANSWER:
            ast_channel_publish_dial(NULL, bridge_channel->chan, NULL, controls[frame->subclass.integer]);
            break;
        case AST_CONTROL_STREAM_TOPOLOGY_REQUEST_CHANGE:
            ast_bridge_channel_lock_bridge(bridge_channel);
            blocked = bridge_channel->bridge->technology->stream_topology_request_change
                && bridge_channel->bridge->technology->stream_topology_request_change(
                    bridge_channel->bridge, bridge_channel);
            ast_bridge_unlock(bridge_channel->bridge);
            if (blocked) {
                /*
                 * Topology change was intercepted by the bridge technology
                 * so drop frame.
                 */
                bridge_frame_free(frame);
                return;
            }
            break;
        case AST_CONTROL_STREAM_TOPOLOGY_CHANGED:
            /*
             * If a stream topology has changed then the bridge_channel's
             * media mapping needs to be updated.
             */
            ast_bridge_channel_lock_bridge(bridge_channel);
            if (bridge_channel->bridge->technology->stream_topology_changed) {
                bridge_channel->bridge->technology->stream_topology_changed(
                    bridge_channel->bridge, bridge_channel);
            } else {
                ast_bridge_channel_stream_map(bridge_channel);
            }
            ast_bridge_unlock(bridge_channel->bridge);
            break;
        default:
            break;
        }
        break;
    case AST_FRAME_DTMF_BEGIN:
    case AST_FRAME_DTMF_END:
        frame = bridge_handle_dtmf(bridge_channel, frame);
        if (!frame) {
            return;
        }
        if (!bridge_channel->features->dtmf_passthrough) {
            bridge_frame_free(frame);
            return;
        }
        break;
    default:
        break;
    }
 
    /* Simply write the frame out to the bridge technology. */
    bridge_channel_write_frame(bridge_channel, frame);
    bridge_frame_free(frame);
}
 
/*!
 * \internal
 * \brief Determine how long till the next timer interval.
 * \since 12.0.0
 *
 * \param bridge_channel Channel to determine how long can wait.
 *
 * \retval ms Number of milliseconds to wait.
 * \retval -1 to wait forever.
 */
static int bridge_channel_next_interval(struct ast_bridge_channel *bridge_channel)
{
    struct ast_heap *interval_hooks = bridge_channel->features->interval_hooks;
    struct ast_bridge_hook_timer *hook;
    int ms;
 
    ast_heap_wrlock(interval_hooks);
    hook = ast_heap_peek(interval_hooks, 1);
    if (hook) {
        ms = ast_tvdiff_ms(hook->timer.trip_time, ast_tvnow());
        if (ms < 0) {
            /* Expire immediately.  An interval hook is ready to run. */
            ms = 0;
        }
    } else {
        /* No hook so wait forever. */
        ms = -1;
    }
    ast_heap_unlock(interval_hooks);
 
    return ms;
}
 
/*!
 * \internal
 * \brief Determine how long till the DTMF interdigit timeout.
 * \since 12.8.0
 *
 * \param bridge_channel Channel to determine how long can wait.
 *
 * \retval ms Number of milliseconds to wait.
 * \retval -1 to wait forever.
 */
static int bridge_channel_feature_timeout(struct ast_bridge_channel *bridge_channel)
{
    int ms;
 
    if (bridge_channel->dtmf_hook_state.collected[0]) {
        ms = ast_tvdiff_ms(bridge_channel->dtmf_hook_state.interdigit_timeout,
            ast_tvnow());
        if (ms < 0) {
            /* Expire immediately. */
            ms = 0;
        }
    } else {
        /* Timer is not active so wait forever. */
        ms = -1;
    }
 
    return ms;
}
 
/*!
 * \internal
 * \brief Determine how long till a timeout.
 * \since 12.8.0
 *
 * \param bridge_channel Channel to determine how long can wait.
 *
 * \retval ms Number of milliseconds to wait.
 * \retval -1 to wait forever.
 */
static int bridge_channel_next_timeout(struct ast_bridge_channel *bridge_channel)
{
    int ms_interval;
    int ms;
 
    ms_interval = bridge_channel_next_interval(bridge_channel);
    ms = bridge_channel_feature_timeout(bridge_channel);
    if (ms < 0 || (0 <= ms_interval && ms_interval < ms)) {
        /* Interval hook timeout is next. */
        ms = ms_interval;
    }
 
    return ms;
}
 
/*!
 * \internal
 * \brief Wait for something to happen on the bridge channel and handle it.
 * \since 12.0.0
 *
 * \param bridge_channel Channel to wait.
 *
 * \note Each channel does writing/reading in their own thread.
 */
static void bridge_channel_wait(struct ast_bridge_channel *bridge_channel)
{
    int ms;
    int outfd;
    struct ast_channel *chan;
 
    /* Wait for data to either come from the channel or us to be signaled */
    ast_bridge_channel_lock(bridge_channel);
    if (bridge_channel->state != BRIDGE_CHANNEL_STATE_WAIT) {
    } else if (bridge_channel->suspended) {
/* XXX ASTERISK-21271 the external party use of suspended will go away as will these references because this is the bridge channel thread */
        ast_debug(1, "Bridge %s: %p(%s) is going into a signal wait\n",
            bridge_channel->bridge->uniqueid, bridge_channel,
            ast_channel_name(bridge_channel->chan));
        ast_cond_wait(&bridge_channel->cond, ao2_object_get_lockaddr(bridge_channel));
    } else {
        ast_bridge_channel_unlock(bridge_channel);
        outfd = -1;
        ms = bridge_channel_next_timeout(bridge_channel);
        chan = ast_waitfor_nandfds(&bridge_channel->chan, 1,
            &bridge_channel->alert_pipe[0], 1, NULL, &outfd, &ms);
        if (ast_channel_unbridged(bridge_channel->chan)) {
            ast_channel_set_unbridged(bridge_channel->chan, 0);
            ast_bridge_channel_lock_bridge(bridge_channel);
            bridge_channel->bridge->reconfigured = 1;
            bridge_reconfigured(bridge_channel->bridge, 0);
            ast_bridge_unlock(bridge_channel->bridge);
        }
        ast_bridge_channel_lock(bridge_channel);
        bridge_channel->activity = BRIDGE_CHANNEL_THREAD_FRAME;
        ast_bridge_channel_unlock(bridge_channel);
        if (!bridge_channel->suspended
            && bridge_channel->state == BRIDGE_CHANNEL_STATE_WAIT) {
            if (chan) {
                bridge_handle_trip(bridge_channel);
            } else if (ms == 0) {
                /* An interdigit timeout or interval expired. */
                bridge_channel_handle_feature_timeout(bridge_channel);
                bridge_channel_handle_interval(bridge_channel);
            } else if (-1 < outfd) {
                /*
                 * Must do this after checking timeouts or may have
                 * an infinite loop due to deferring write queue
                 * actions while trying to match DTMF feature hooks.
                 */
                bridge_channel_handle_write(bridge_channel);
            }
        }
        bridge_channel->activity = BRIDGE_CHANNEL_THREAD_IDLE;
        return;
    }
    ast_bridge_channel_unlock(bridge_channel);
}
 
/*!
 * \internal
 * \brief Handle bridge channel join/leave event.
 * \since 12.0.0
 *
 * \param bridge_channel Which channel is involved.
 * \param type Specified join/leave event.
 */
static void bridge_channel_event_join_leave(struct ast_bridge_channel *bridge_channel, enum ast_bridge_hook_type type)
{
    struct ast_bridge_features *features = bridge_channel->features;
    struct ast_bridge_hook *hook;
    struct ao2_iterator iter;
 
    /* Run the specified hooks. */
    iter = ao2_iterator_init(features->other_hooks, 0);
    for (; (hook = ao2_iterator_next(&iter)); ao2_ref(hook, -1)) {
        if (hook->type == type) {
            break;
        }
    }
    if (hook) {
        /* Found the first specified hook to run. */
        bridge_channel_suspend(bridge_channel);
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        do {
            if (hook->type == type) {
                hook->callback(bridge_channel, hook->hook_pvt);
                ao2_unlink(features->other_hooks, hook);
            }
            ao2_ref(hook, -1);
        } while ((hook = ao2_iterator_next(&iter)));
        ast_indicate(bridge_channel->chan, AST_CONTROL_SRCUPDATE);
        bridge_channel_unsuspend(bridge_channel);
    }
    ao2_iterator_destroy(&iter);
}
 
int bridge_channel_internal_join(struct ast_bridge_channel *bridge_channel)
{
    int res = 0;
    uint8_t indicate_src_change = 0;
    struct ast_bridge_features *channel_features;
    struct ast_channel *peer;
    struct ast_channel *swap;
 
    ast_debug(1, "Bridge %s: %p(%s) is joining\n",
        bridge_channel->bridge->uniqueid,
        bridge_channel, ast_channel_name(bridge_channel->chan));
 
    /*
     * Directly locking the bridge is safe here because nobody else
     * knows about this bridge_channel yet.
     */
    ast_bridge_lock(bridge_channel->bridge);
 
    ast_channel_lock(bridge_channel->chan);
    peer = ast_local_get_peer(bridge_channel->chan);
 
    if (peer) {
        struct ast_bridge *peer_bridge;
 
        ast_channel_unlock(bridge_channel->chan);
 
        ast_channel_lock(peer);
        peer_bridge = ast_channel_internal_bridge(peer);
        ast_channel_unlock(peer);
        ast_channel_unref(peer);
 
        /* As we are only doing a pointer comparison we don't need the peer_bridge
         * to be reference counted or locked.
         */
        if (peer_bridge == bridge_channel->bridge) {
            ast_bridge_unlock(bridge_channel->bridge);
            ast_debug(1, "Bridge %s: %p(%s) denying Bridge join to prevent Local channel loop\n",
                bridge_channel->bridge->uniqueid,
                bridge_channel,
                ast_channel_name(bridge_channel->chan));
            return -1;
        }
 
        ast_channel_lock(bridge_channel->chan);
    }
 
    bridge_channel->read_format = ao2_bump(ast_channel_readformat(bridge_channel->chan));
    bridge_channel->write_format = ao2_bump(ast_channel_writeformat(bridge_channel->chan));
 
    /* Make sure we're still good to be put into a bridge */
    if (ast_channel_internal_bridge(bridge_channel->chan)
        || ast_test_flag(ast_channel_flags(bridge_channel->chan), AST_FLAG_ZOMBIE)) {
        ast_channel_unlock(bridge_channel->chan);
        ast_bridge_unlock(bridge_channel->bridge);
        ast_debug(1, "Bridge %s: %p(%s) failed to join Bridge\n",
            bridge_channel->bridge->uniqueid,
            bridge_channel,
            ast_channel_name(bridge_channel->chan));
        return -1;
    }
    ast_channel_internal_bridge_set(bridge_channel->chan, bridge_channel->bridge);
 
    /* Attach features requested by the channel */
    channel_features = ast_channel_feature_hooks_get(bridge_channel->chan);
    if (channel_features) {
        ast_bridge_features_merge(bridge_channel->features, channel_features);
    }
    ast_channel_unlock(bridge_channel->chan);
 
    /* Add the jitterbuffer if the channel requires it */
    ast_jb_enable_for_channel(bridge_channel->chan);
 
    if (!bridge_channel->bridge->callid) {
        bridge_channel->bridge->callid = ast_read_threadstorage_callid();
    }
 
    /* Take the swap channel ref from the bridge_channel struct. */
    swap = bridge_channel->swap;
 
    if (bridge_channel_internal_push(bridge_channel)) {
        int cause = bridge_channel->bridge->cause;
 
        ast_bridge_unlock(bridge_channel->bridge);
        ast_bridge_channel_kick(bridge_channel, cause);
        ast_bridge_channel_lock_bridge(bridge_channel);
        ast_bridge_features_remove(bridge_channel->features,
            AST_BRIDGE_HOOK_REMOVE_ON_PULL);
        bridge_channel_dissolve_check(bridge_channel);
        res = -1;
    }
    bridge_reconfigured(bridge_channel->bridge, !bridge_channel->inhibit_colp);
 
    if (bridge_channel->state == BRIDGE_CHANNEL_STATE_WAIT) {
        /*
         * Indicate a source change since this channel is entering the
         * bridge system only if the bridge technology is not MULTIMIX
         * capable.  The MULTIMIX technology has already done it.
         */
        if (!(bridge_channel->bridge->technology->capabilities
            & AST_BRIDGE_CAPABILITY_MULTIMIX)) {
            indicate_src_change = 1;
        }
 
        bridge_channel_impart_signal(bridge_channel->chan);
        ast_bridge_unlock(bridge_channel->bridge);
 
        /* Must release any swap ref after unlocking the bridge. */
        ao2_t_cleanup(swap, "Bridge push with swap successful");
        swap = NULL;
 
        if (indicate_src_change) {
            ast_indicate(bridge_channel->chan, AST_CONTROL_SRCCHANGE);
        }
 
        bridge_channel_event_join_leave(bridge_channel, AST_BRIDGE_HOOK_TYPE_JOIN);
 
        while (bridge_channel->state == BRIDGE_CHANNEL_STATE_WAIT) {
            /* Wait for something to do. */
            bridge_channel_wait(bridge_channel);
        }
 
        /* Force a timeout on any accumulated DTMF hook digits. */
        ast_bridge_channel_feature_digit(bridge_channel, 0);
 
        bridge_channel_event_join_leave(bridge_channel, AST_BRIDGE_HOOK_TYPE_LEAVE);
        ast_bridge_channel_lock_bridge(bridge_channel);
    }
 
    bridge_channel_internal_pull(bridge_channel);
    bridge_channel_settle_owed_events(bridge_channel->bridge, bridge_channel);
    bridge_reconfigured(bridge_channel->bridge, 1);
 
    /* Remove ourselves if we are the video source */
    ast_bridge_remove_video_src(bridge_channel->bridge, bridge_channel->chan);
 
    ast_bridge_unlock(bridge_channel->bridge);
 
    /* Must release any swap ref after unlocking the bridge. */
    ao2_t_cleanup(swap, "Bridge push with swap failed or exited immediately");
 
    /* Complete any active hold before exiting the bridge. */
    if (ast_channel_hold_state(bridge_channel->chan) == AST_CONTROL_HOLD) {
        ast_debug(1, "Channel %s simulating UNHOLD for bridge end.\n",
            ast_channel_name(bridge_channel->chan));
        ast_indicate(bridge_channel->chan, AST_CONTROL_UNHOLD);
    }
 
    /* Complete any partial DTMF digit before exiting the bridge. */
    if (ast_channel_sending_dtmf_digit(bridge_channel->chan)) {
        ast_channel_end_dtmf(bridge_channel->chan,
            ast_channel_sending_dtmf_digit(bridge_channel->chan),
            ast_channel_sending_dtmf_tv(bridge_channel->chan), "bridge end");
    }
 
    /* Complete any T.38 session before exiting the bridge. */
    if (ast_channel_is_t38_active(bridge_channel->chan)) {
        struct ast_control_t38_parameters t38_parameters = {
            .request_response = AST_T38_TERMINATED,
        };
 
        ast_debug(1, "Channel %s simulating T.38 terminate for bridge end.\n",
            ast_channel_name(bridge_channel->chan));
        ast_indicate_data(bridge_channel->chan, AST_CONTROL_T38_PARAMETERS,
            &t38_parameters, sizeof(t38_parameters));
    }
 
    /* Indicate a source change since this channel is leaving the bridge system. */
    ast_indicate(bridge_channel->chan, AST_CONTROL_SRCCHANGE);
 
    /*
     * Wait for any dual redirect to complete.
     *
     * Must be done while "still in the bridge" for ast_async_goto()
     * to work right.
     */
    while (ast_test_flag(ast_channel_flags(bridge_channel->chan), AST_FLAG_BRIDGE_DUAL_REDIRECT_WAIT)) {
        sched_yield();
    }
    ast_channel_lock(bridge_channel->chan);
    ast_channel_internal_bridge_set(bridge_channel->chan, NULL);
    ast_channel_unlock(bridge_channel->chan);
 
    ast_bridge_channel_restore_formats(bridge_channel);
 
    return res;
}
 
int bridge_channel_internal_queue_blind_transfer(struct ast_channel *transferee,
        const char *exten, const char *context,
        transfer_channel_cb new_channel_cb, void *user_data)
{
    RAII_VAR(struct ast_bridge_channel *, transferee_bridge_channel, NULL, ao2_cleanup);
    struct blind_transfer_data blind_data;
 
    ast_channel_lock(transferee);
    transferee_bridge_channel = ast_channel_get_bridge_channel(transferee);
    ast_channel_unlock(transferee);
 
    if (!transferee_bridge_channel) {
        return -1;
    }
 
    if (new_channel_cb) {
        new_channel_cb(transferee, user_data, AST_BRIDGE_TRANSFER_SINGLE_PARTY);
    }
 
    ast_copy_string(blind_data.exten, exten, sizeof(blind_data.exten));
    ast_copy_string(blind_data.context, context, sizeof(blind_data.context));
 
    return bridge_channel_queue_action_data(transferee_bridge_channel,
        BRIDGE_CHANNEL_ACTION_BLIND_TRANSFER, &blind_data, sizeof(blind_data));
}
 
int bridge_channel_internal_queue_attended_transfer(struct ast_channel *transferee,
        struct ast_channel *unbridged_chan)
{
    RAII_VAR(struct ast_bridge_channel *, transferee_bridge_channel, NULL, ao2_cleanup);
    char unbridged_chan_name[AST_CHANNEL_NAME];
 
    ast_channel_lock(transferee);
    transferee_bridge_channel = ast_channel_get_bridge_channel(transferee);
    ast_channel_unlock(transferee);
 
    if (!transferee_bridge_channel) {
        return -1;
    }
 
    ast_copy_string(unbridged_chan_name, ast_channel_name(unbridged_chan),
        sizeof(unbridged_chan_name));
 
    return bridge_channel_queue_action_data(transferee_bridge_channel,
        BRIDGE_CHANNEL_ACTION_ATTENDED_TRANSFER, unbridged_chan_name,
        sizeof(unbridged_chan_name));
}
 
int bridge_channel_internal_allows_optimization(struct ast_bridge_channel *bridge_channel)
{
    return bridge_channel->in_bridge
        && AST_LIST_EMPTY(&bridge_channel->wr_queue);
}
 
/* Destroy elements of the bridge channel structure and the bridge channel structure itself */
static void bridge_channel_destroy(void *obj)
{
    struct ast_bridge_channel *bridge_channel = obj;
    struct ast_frame *fr;
 
    if (bridge_channel->callid) {
        bridge_channel->callid = 0;
    }
 
    if (bridge_channel->bridge) {
        ao2_ref(bridge_channel->bridge, -1);
        bridge_channel->bridge = NULL;
    }
 
    /* Flush any unhandled wr_queue frames. */
    while ((fr = AST_LIST_REMOVE_HEAD(&bridge_channel->wr_queue, frame_list))) {
        bridge_frame_free(fr);
    }
    ast_alertpipe_close(bridge_channel->alert_pipe);
 
    /* Flush any unhandled deferred_queue frames. */
    while ((fr = AST_LIST_REMOVE_HEAD(&bridge_channel->deferred_queue, frame_list))) {
        ast_frfree(fr);
    }
 
    ast_cond_destroy(&bridge_channel->cond);
 
    ao2_cleanup(bridge_channel->write_format);
    ao2_cleanup(bridge_channel->read_format);
 
    AST_VECTOR_FREE(&bridge_channel->stream_map.to_bridge);
    AST_VECTOR_FREE(&bridge_channel->stream_map.to_channel);
}
 
struct ast_bridge_channel *bridge_channel_internal_alloc(struct ast_bridge *bridge)
{
    struct ast_bridge_channel *bridge_channel;
 
    bridge_channel = ao2_alloc(sizeof(struct ast_bridge_channel), bridge_channel_destroy);
    if (!bridge_channel) {
        return NULL;
    }
    ast_cond_init(&bridge_channel->cond, NULL);
    if (ast_alertpipe_init(bridge_channel->alert_pipe)) {
        ao2_ref(bridge_channel, -1);
        return NULL;
    }
    if (bridge) {
        bridge_channel->bridge = bridge;
        ao2_ref(bridge_channel->bridge, +1);
    }
 
    /* The stream_map is initialized later - see ast_bridge_channel_stream_map */
 
    return bridge_channel;
}
 
void ast_bridge_channel_stream_map(struct ast_bridge_channel *bridge_channel)
{
    ast_bridge_channel_lock(bridge_channel);
    ast_channel_lock(bridge_channel->chan);
    ast_stream_topology_map(ast_channel_get_stream_topology(bridge_channel->chan),
        &bridge_channel->bridge->media_types, &bridge_channel->stream_map.to_bridge,
        &bridge_channel->stream_map.to_channel);
    ast_channel_unlock(bridge_channel->chan);
    ast_bridge_channel_unlock(bridge_channel);
}