resource_bridges.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2012 - 2013, Digium, Inc.
 *
 * David M. Lee, II <dlee@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 Implementation for ARI stubs.
 *
 * \author David M. Lee, II <dlee@digium.com>
 */
 
/*** MODULEINFO
    <support_level>core</support_level>
 ***/
 
#include "asterisk.h"
 
#include "resource_bridges.h"
#include "asterisk/stasis.h"
#include "asterisk/stasis_bridges.h"
#include "asterisk/stasis_app.h"
#include "asterisk/stasis_app_impl.h"
#include "asterisk/stasis_app_playback.h"
#include "asterisk/stasis_app_recording.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/core_unreal.h"
#include "asterisk/channel.h"
#include "asterisk/bridge.h"
#include "asterisk/format_cap.h"
#include "asterisk/file.h"
#include "asterisk/musiconhold.h"
#include "asterisk/format_cache.h"
 
/*!
 * \brief Finds a bridge, filling the response with an error, if appropriate.
 *
 * \param[out] response Response to fill with an error if control is not found.
 * \param bridge_id ID of the bridge to lookup.
 *
 * \return Bridget.
 * \retval NULL if bridge does not exist.
 */
static struct ast_bridge *find_bridge(
    struct ast_ari_response *response,
    const char *bridge_id)
{
    RAII_VAR(struct ast_bridge *, bridge, NULL, ao2_cleanup);
 
    ast_assert(response != NULL);
 
    bridge = stasis_app_bridge_find_by_id(bridge_id);
    if (bridge == NULL) {
        RAII_VAR(struct ast_bridge_snapshot *, snapshot,
            ast_bridge_get_snapshot_by_uniqueid(bridge_id), ao2_cleanup);
        if (!snapshot) {
            ast_ari_response_error(response, 404, "Not found",
                "Bridge not found");
            return NULL;
        }
 
        ast_ari_response_error(response, 409, "Conflict",
            "Bridge not in Stasis application");
        return NULL;
    }
 
    ao2_ref(bridge, +1);
    return bridge;
}
 
/*!
 * \brief Finds the control object for a channel, filling the response with an
 * error, if appropriate.
 * \param[out] response Response to fill with an error if control is not found.
 * \param channel_id ID of the channel to lookup.
 * \return Channel control object.
 * \retval NULL if control object does not exist.
 */
static struct stasis_app_control *find_channel_control(
    struct ast_ari_response *response,
    const char *channel_id)
{
    RAII_VAR(struct stasis_app_control *, control, NULL, ao2_cleanup);
 
    ast_assert(response != NULL);
 
    control = stasis_app_control_find_by_channel_id(channel_id);
    if (control == NULL) {
        /* Distinguish between 400 and 422 errors */
        RAII_VAR(struct ast_channel_snapshot *, snapshot, NULL,
            ao2_cleanup);
        snapshot = ast_channel_snapshot_get_latest(channel_id);
        if (snapshot == NULL) {
            ast_log(LOG_DEBUG, "Couldn't find '%s'\n", channel_id);
            ast_ari_response_error(response, 400, "Bad Request",
                "Channel not found");
            return NULL;
        }
 
        ast_log(LOG_DEBUG, "Found non-stasis '%s'\n", channel_id);
        ast_ari_response_error(response, 422, "Unprocessable Entity",
            "Channel not in Stasis application");
        return NULL;
    }
 
    ao2_ref(control, +1);
    return control;
}
 
struct control_list {
    size_t count;
    struct stasis_app_control *controls[];
};
 
static void control_list_dtor(void *obj) {
    struct control_list *list = obj;
    size_t i;
 
    for (i = 0; i < list->count; ++i) {
        ao2_cleanup(list->controls[i]);
        list->controls[i] = NULL;
    }
}
 
static struct control_list *control_list_create(struct ast_ari_response *response, size_t count, const char **channels) {
    RAII_VAR(struct control_list *, list, NULL, ao2_cleanup);
    size_t i;
 
    if (count == 0 || !channels) {
        ast_ari_response_error(response, 400, "Bad Request", "Missing parameter channel");
        return NULL;
    }
 
    list = ao2_alloc(sizeof(*list) + count * sizeof(list->controls[0]), control_list_dtor);
    if (!list) {
        ast_ari_response_alloc_failed(response);
        return NULL;
    }
 
    for (i = 0; i < count; ++i) {
        if (ast_strlen_zero(channels[i])) {
            continue;
        }
        list->controls[list->count] =
            find_channel_control(response, channels[i]);
        if (!list->controls[list->count]) {
            /* response filled in by find_channel_control() */
            return NULL;
        }
        ++list->count;
    }
 
    if (list->count == 0) {
        ast_ari_response_error(response, 400, "Bad Request", "Missing parameter channel");
        return NULL;
    }
 
    ao2_ref(list, +1);
    return list;
}
 
static int check_add_remove_channel(struct ast_ari_response *response,
                    struct stasis_app_control *control,
                    enum stasis_app_control_channel_result result)
{
    switch (result) {
    case STASIS_APP_CHANNEL_RECORDING :
        ast_ari_response_error(
            response, 409, "Conflict", "Channel %s currently recording",
            stasis_app_control_get_channel_id(control));
        return -1;
    case STASIS_APP_CHANNEL_OKAY:
        return 0;
    }
    return 0;
}
 
void ast_ari_bridges_add_channel(struct ast_variable *headers,
    struct ast_ari_bridges_add_channel_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, find_bridge(response, args->bridge_id), ao2_cleanup);
    RAII_VAR(struct control_list *, list, NULL, ao2_cleanup);
    size_t i;
    int has_error = 0;
 
    if (!bridge) {
        /* Response filled in by find_bridge() */
        return;
    }
 
    list = control_list_create(response, args->channel_count, args->channel);
    if (!list) {
        /* Response filled in by control_list_create() */
        return;
    }
 
    for (i = 0; i < list->count; ++i) {
        stasis_app_control_clear_roles(list->controls[i]);
        if (!ast_strlen_zero(args->role)) {
            if (stasis_app_control_add_role(list->controls[i], args->role)) {
                ast_ari_response_alloc_failed(response);
                return;
            }
        }
 
        /* Apply bridge features to each of the channel controls */
        if (!stasis_app_control_bridge_features_init(list->controls[i])) {
            stasis_app_control_absorb_dtmf_in_bridge(list->controls[i], args->absorb_dtmf);
            stasis_app_control_mute_in_bridge(list->controls[i], args->mute);
            stasis_app_control_inhibit_colp_in_bridge(list->controls[i], args->inhibit_connected_line_updates);
        }
    }
 
    for (i = 0; i < list->count; ++i) {
        if ((has_error = check_add_remove_channel(response, list->controls[i],
                 stasis_app_control_add_channel_to_bridge(
                    list->controls[i], bridge)))) {
            break;
        }
    }
 
    if (!has_error) {
        ast_ari_response_no_content(response);
    }
}
 
void ast_ari_bridges_remove_channel(struct ast_variable *headers,
    struct ast_ari_bridges_remove_channel_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, find_bridge(response, args->bridge_id), ao2_cleanup);
    RAII_VAR(struct control_list *, list, NULL, ao2_cleanup);
    size_t i;
 
    if (!bridge) {
        /* Response filled in by find_bridge() */
        return;
    }
 
    list = control_list_create(response, args->channel_count, args->channel);
    if (!list) {
        /* Response filled in by control_list_create() */
        return;
    }
 
    /* Make sure all of the channels are in this bridge */
    for (i = 0; i < list->count; ++i) {
        if (stasis_app_get_bridge(list->controls[i]) != bridge) {
            ast_log(LOG_WARNING, "Channel %s not in bridge %s\n",
                args->channel[i], args->bridge_id);
            ast_ari_response_error(response, 422,
                "Unprocessable Entity",
                "Channel not in this bridge");
            return;
        }
    }
 
    /* Now actually remove it */
    for (i = 0; i < list->count; ++i) {
        stasis_app_control_remove_channel_from_bridge(list->controls[i],
            bridge);
    }
 
    ast_ari_response_no_content(response);
}
 
struct bridge_channel_control_thread_data {
    struct ast_channel *bridge_channel;
    struct stasis_app_control *control;
    struct stasis_forward *forward;
    char bridge_id[0];
};
 
static void *bridge_channel_control_thread(void *data)
{
    struct bridge_channel_control_thread_data *thread_data = data;
    struct ast_channel *bridge_channel = thread_data->bridge_channel;
    struct stasis_app_control *control = thread_data->control;
    struct stasis_forward *forward = thread_data->forward;
    ast_callid callid = ast_channel_callid(bridge_channel);
    char *bridge_id = ast_strdupa(thread_data->bridge_id);
 
    if (callid) {
        ast_callid_threadassoc_add(callid);
    }
 
    ast_free(thread_data);
    thread_data = NULL;
 
    stasis_app_control_execute_until_exhausted(bridge_channel, control);
    stasis_app_control_flush_queue(control);
 
    stasis_app_bridge_playback_channel_remove(bridge_id, control);
    stasis_forward_cancel(forward);
    ao2_cleanup(control);
    ast_hangup(bridge_channel);
    return NULL;
}
 
static struct ast_channel *prepare_bridge_media_channel(const char *type,
    struct ast_format *channel_format)
{
    RAII_VAR(struct ast_format_cap *, cap, NULL, ao2_cleanup);
    struct ast_channel *chan;
 
    cap = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
    if (!cap) {
        return NULL;
    }
 
    /* This bumps the format's refcount */
    ast_format_cap_append(cap, channel_format, 0);
 
    chan = ast_request(type, cap, NULL, NULL, "ARI", NULL);
    if (!chan) {
        return NULL;
    }
 
    if (stasis_app_channel_unreal_set_internal(chan)) {
        ast_channel_cleanup(chan);
        return NULL;
    }
    return chan;
}
 
/*!
 * \brief Performs common setup for a bridge playback operation
 * with both new controls and when existing controls are  found.
 *
 * \param args_media medias to play
 * \param args_media_count number of media items in \c media
 * \param args_lang language string split from arguments
 * \param args_offset_ms milliseconds offset split from arguments
 * \param args_skipms
 * \param args_playback_id string to use for playback split from
 *        arguments (null valid)
 * \param response ARI response being built
 * \param bridge Bridge the playback is being performed on
 * \param control Control being used for the playback channel
 * \param json contents of the response to ARI
 * \param playback_url stores playback URL for use with response
 *
 * \retval -1 operation failed
 * \return operation was successful
 */
static int ari_bridges_play_helper(const char **args_media,
    size_t args_media_count,
    const char *args_lang,
    int args_offset_ms,
    int args_skipms,
    const char *args_playback_id,
    struct ast_ari_response *response,
    struct ast_bridge *bridge,
    struct stasis_app_control *control,
    struct ast_json **json,
    char **playback_url)
{
    RAII_VAR(struct ast_channel_snapshot *, snapshot, NULL, ao2_cleanup);
    RAII_VAR(struct stasis_app_playback *, playback, NULL, ao2_cleanup);
 
    const char *language;
 
    snapshot = stasis_app_control_get_snapshot(control);
    if (!snapshot) {
        ast_ari_response_error(
            response, 500, "Internal Error", "Failed to get control snapshot");
        return -1;
    }
 
    language = S_OR(args_lang, snapshot->base->language);
 
    playback = stasis_app_control_play_uri(control, args_media, args_media_count,
        language, bridge->uniqueid, STASIS_PLAYBACK_TARGET_BRIDGE, args_skipms,
        args_offset_ms, args_playback_id);
 
    if (!playback) {
        ast_ari_response_alloc_failed(response);
        return -1;
    }
 
    if (ast_asprintf(playback_url, "/playbacks/%s",
            stasis_app_playback_get_id(playback)) == -1) {
        ast_ari_response_alloc_failed(response);
        return -1;
    }
 
    *json = stasis_app_playback_to_json(playback);
    if (!*json) {
        ast_ari_response_alloc_failed(response);
        return -1;
    }
 
    return 0;
}
 
static void ari_bridges_play_new(const char **args_media,
    size_t args_media_count,
    const char *args_format,
    const char *args_lang,
    int args_offset_ms,
    int args_skipms,
    const char *args_playback_id,
    struct ast_ari_response *response,
    struct ast_bridge *bridge)
{
    RAII_VAR(struct ast_channel *, play_channel, NULL, ast_hangup);
    RAII_VAR(struct stasis_app_control *, control, NULL, ao2_cleanup);
    RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
    RAII_VAR(struct stasis_forward *, channel_forward, NULL, stasis_forward_cancel);
    RAII_VAR(char *, playback_url, NULL, ast_free);
 
    struct stasis_topic *channel_topic;
    struct stasis_topic *bridge_topic;
    struct bridge_channel_control_thread_data *thread_data;
    pthread_t threadid;
    struct ast_format *channel_format = NULL;
 
    struct ast_frame prog = {
        .frametype = AST_FRAME_CONTROL,
        .subclass.integer = AST_CONTROL_PROGRESS,
    };
 
    /*
     * Determine the format for the playback channel.
     * If a format was specified, use that if it's valid.
     * Otherwise, if the bridge is empty, use slin.
     * If the bridge has one channel, use that channel's raw write format.
     * If the bridge has multiple channels, use the slin format that
     * will handle the highest sample rate of the raw write format of all the channels.
     */
    if (!ast_strlen_zero(args_format)) {
        channel_format = ast_format_cache_get(args_format);
        if (!channel_format) {
            ast_ari_response_error(
                response, 422, "Unprocessable Entity",
                "specified announcer_format is unknown on this system");
            return;
        }
        /*
         * ast_format_cache_get() bumps the refcount but the other calls
         * to retrieve formats don't so we'll drop this reference.
         * It'll be bumped again in the prepare_bridge_media_channel() call below.
         */
        ao2_ref(channel_format, -1);
    } else {
        ast_bridge_lock(bridge);
        if (bridge->num_channels == 0) {
            channel_format = ast_format_slin;
        } else if (bridge->num_channels == 1) {
            struct ast_bridge_channel *bc = NULL;
            bc = AST_LIST_FIRST(&bridge->channels);
            if (bc) {
                channel_format = ast_channel_rawwriteformat(bc->chan);
            }
        } else {
            struct ast_bridge_channel *bc = NULL;
            unsigned int max_sample_rate = 0;
            AST_LIST_TRAVERSE(&bridge->channels, bc, entry) {
                struct ast_format *fmt = ast_channel_rawwriteformat(bc->chan);
                max_sample_rate = MAX(ast_format_get_sample_rate(fmt), max_sample_rate);
            }
            channel_format = ast_format_cache_get_slin_by_rate(max_sample_rate);
        }
        ast_bridge_unlock(bridge);
    }
 
    if (!channel_format) {
        channel_format = ast_format_slin;
    }
 
    play_channel = prepare_bridge_media_channel("Announcer", channel_format);
    ao2_cleanup(channel_format);
    if (!play_channel) {
        ast_ari_response_error(
            response, 500, "Internal Error", "Could not create playback channel");
        return;
    }
    ast_debug(1, "Created announcer channel '%s'\n", ast_channel_name(play_channel));
 
    bridge_topic = ast_bridge_topic(bridge);
    channel_topic = ast_channel_topic(play_channel);
 
    /* Forward messages from the playback channel topic to the bridge topic so that anything listening for
     * messages on the bridge topic will receive the playback start/stop messages. Other messages that would
     * go to this channel will be suppressed since the channel is marked as internal.
     */
    if (!bridge_topic || !channel_topic || !(channel_forward = stasis_forward_all(channel_topic, bridge_topic))) {
        ast_ari_response_error(
            response, 500, "Internal Error", "Could not forward playback channel stasis messages to bridge topic");
        return;
    }
 
    if (ast_unreal_channel_push_to_bridge(play_channel, bridge,
        AST_BRIDGE_CHANNEL_FLAG_IMMOVABLE | AST_BRIDGE_CHANNEL_FLAG_LONELY)) {
        ast_ari_response_error(
            response, 500, "Internal Error", "Failed to put playback channel into the bridge");
        return;
    }
 
    control = stasis_app_control_create(play_channel);
    if (control == NULL) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    ao2_lock(control);
    if (ari_bridges_play_helper(args_media, args_media_count, args_lang,
            args_offset_ms, args_skipms, args_playback_id, response, bridge,
            control, &json, &playback_url)) {
        ao2_unlock(control);
        return;
    }
    ao2_unlock(control);
 
    if (stasis_app_bridge_playback_channel_add(bridge, play_channel, control)) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    ast_bridge_queue_everyone_else(bridge, NULL, &prog);
 
    /* Give play_channel and control reference to the thread data */
    thread_data = ast_malloc(sizeof(*thread_data) + strlen(bridge->uniqueid) + 1);
    if (!thread_data) {
        stasis_app_bridge_playback_channel_remove((char *)bridge->uniqueid, control);
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    thread_data->bridge_channel = play_channel;
    thread_data->control = control;
    thread_data->forward = channel_forward;
    /* Safe */
    strcpy(thread_data->bridge_id, bridge->uniqueid);
 
    if (ast_pthread_create_detached(&threadid, NULL, bridge_channel_control_thread, thread_data)) {
        stasis_app_bridge_playback_channel_remove((char *)bridge->uniqueid, control);
        ast_ari_response_alloc_failed(response);
        ast_free(thread_data);
        return;
    }
 
    /* These are owned by the other thread now, so we don't want RAII_VAR disposing of them. */
    play_channel = NULL;
    control = NULL;
    channel_forward = NULL;
 
    ast_ari_response_created(response, playback_url, ast_json_ref(json));
}
 
enum play_found_result {
    PLAY_FOUND_SUCCESS,
    PLAY_FOUND_FAILURE,
    PLAY_FOUND_CHANNEL_UNAVAILABLE,
};
 
/*!
 * \brief Performs common setup for a bridge playback operation
 * with both new controls and when existing controls are  found.
 *
 * \param args_media medias to play
 * \param args_media_count number of media items in \c media
 * \param args_lang language string split from arguments
 * \param args_offset_ms milliseconds offset split from arguments
 * \param args_skipms
 * \param args_playback_id string to use for playback split from
 *        arguments (null valid)
 * \param response ARI response being built
 * \param bridge Bridge the playback is being performed on
 * \param found_channel The channel that was found controlling playback
 *
 * \retval PLAY_FOUND_SUCCESS The operation was successful
 * \retval PLAY_FOUND_FAILURE The operation failed (terminal failure)
 * \retval PLAY_FOUND_CHANNEL_UNAVAILABLE The operation failed because
 * the channel requested to playback with is breaking down.
 */
static enum play_found_result ari_bridges_play_found(const char **args_media,
    size_t args_media_count,
    const char *args_lang,
    int args_offset_ms,
    int args_skipms,
    const char *args_playback_id,
    struct ast_ari_response *response,
    struct ast_bridge *bridge,
    struct ast_channel *found_channel)
{
    RAII_VAR(struct ast_channel *, play_channel, found_channel, ao2_cleanup);
    RAII_VAR(struct stasis_app_control *, control, NULL, ao2_cleanup);
    RAII_VAR(char *, playback_url, NULL, ast_free);
    RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
 
    control = stasis_app_control_find_by_channel(play_channel);
    if (!control) {
        return PLAY_FOUND_CHANNEL_UNAVAILABLE;
    }
 
    ao2_lock(control);
    if (stasis_app_control_is_done(control)) {
        /* We failed to queue the action. Bailout and return that we aren't terminal. */
        ao2_unlock(control);
        return PLAY_FOUND_CHANNEL_UNAVAILABLE;
    }
 
    if (ari_bridges_play_helper(args_media, args_media_count,
            args_lang, args_offset_ms, args_skipms, args_playback_id,
            response, bridge, control, &json, &playback_url)) {
        ao2_unlock(control);
        return PLAY_FOUND_FAILURE;
    }
    ao2_unlock(control);
 
    ast_ari_response_created(response, playback_url, ast_json_ref(json));
    return PLAY_FOUND_SUCCESS;
}
 
static void ari_bridges_handle_play(
    const char *args_bridge_id,
    const char **args_media,
    size_t args_media_count,
    const char *args_format,
    const char *args_lang,
    int args_offset_ms,
    int args_skipms,
    const char *args_playback_id,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, find_bridge(response, args_bridge_id), ao2_cleanup);
    struct ast_channel *play_channel;
 
    ast_assert(response != NULL);
 
    if (!bridge) {
        return;
    }
 
    while ((play_channel = stasis_app_bridge_playback_channel_find(bridge))) {
        /* If ari_bridges_play_found fails because the channel is unavailable for
         * playback, The channel will be removed from the playback list soon. We
         * can keep trying to get channels from the list until we either get one
         * that will work or else there isn't a channel for this bridge anymore,
         * in which case we'll revert to ari_bridges_play_new.
         */
        if (ari_bridges_play_found(args_media, args_media_count, args_lang,
                args_offset_ms, args_skipms, args_playback_id, response,bridge,
                play_channel) == PLAY_FOUND_CHANNEL_UNAVAILABLE) {
            continue;
        }
        return;
    }
 
    ari_bridges_play_new(args_media, args_media_count, args_format, args_lang, args_offset_ms,
        args_skipms, args_playback_id, response, bridge);
}
 
 
void ast_ari_bridges_play(struct ast_variable *headers,
    struct ast_ari_bridges_play_args *args,
    struct ast_ari_response *response)
{
    ari_bridges_handle_play(args->bridge_id,
    args->media,
    args->media_count,
    args->announcer_format,
    args->lang,
    args->offsetms,
    args->skipms,
    args->playback_id,
    response);
}
 
void ast_ari_bridges_play_with_id(struct ast_variable *headers,
    struct ast_ari_bridges_play_with_id_args *args,
    struct ast_ari_response *response)
{
    ari_bridges_handle_play(args->bridge_id,
    args->media,
    args->media_count,
    args->announcer_format,
    args->lang,
    args->offsetms,
    args->skipms,
    args->playback_id,
    response);
}
 
void ast_ari_bridges_record(struct ast_variable *headers,
    struct ast_ari_bridges_record_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, find_bridge(response, args->bridge_id), ao2_cleanup);
    RAII_VAR(struct ast_channel *, record_channel, NULL, ast_hangup);
    RAII_VAR(struct stasis_app_control *, control, NULL, ao2_cleanup);
    RAII_VAR(struct stasis_app_recording *, recording, NULL, ao2_cleanup);
    RAII_VAR(char *, recording_url, NULL, ast_free);
    RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
    RAII_VAR(struct stasis_app_recording_options *, options, NULL, ao2_cleanup);
    RAII_VAR(char *, uri_encoded_name, NULL, ast_free);
    RAII_VAR(struct stasis_forward *, channel_forward, NULL, stasis_forward_cancel);
 
    struct stasis_topic *channel_topic;
    struct stasis_topic *bridge_topic;
    size_t uri_name_maxlen;
    struct bridge_channel_control_thread_data *thread_data;
    pthread_t threadid;
    struct ast_format *file_format = NULL;
    struct ast_format *channel_format = NULL;
 
    ast_assert(response != NULL);
 
    if (bridge == NULL) {
        return;
    }
 
    file_format = ast_get_format_for_file_ext(args->format);
    if (!file_format) {
        ast_ari_response_error(
            response, 422, "Unprocessable Entity",
            "specified format is unknown on this system");
        return;
    }
 
    if (!ast_strlen_zero(args->recorder_format)) {
        channel_format = ast_format_cache_get(args->recorder_format);
        if (!channel_format) {
            ast_ari_response_error(
                response, 422, "Unprocessable Entity",
                "specified recorder_format is unknown on this system");
            return;
        }
        /*
         * ast_format_cache_get() bumps the refcount but the other calls
         * to retrieve formats don't so we'll drop this reference.
         * It'll be bumped again in the prepare_bridge_media_channel() call below.
         */
        ao2_ref(channel_format, -1);
 
    } else {
        channel_format = file_format;
    }
 
    if (!(record_channel = prepare_bridge_media_channel("Recorder", channel_format))) {
        ast_ari_response_error(
            response, 500, "Internal Server Error", "Failed to create recording channel");
        return;
    }
 
    bridge_topic = ast_bridge_topic(bridge);
    channel_topic = ast_channel_topic(record_channel);
 
    /* Forward messages from the recording channel topic to the bridge topic so that anything listening for
     * messages on the bridge topic will receive the recording start/stop messages. Other messages that would
     * go to this channel will be suppressed since the channel is marked as internal.
     */
    if (!bridge_topic || !channel_topic || !(channel_forward = stasis_forward_all(channel_topic, bridge_topic))) {
        ast_ari_response_error(
            response, 500, "Internal Error", "Could not forward record channel stasis messages to bridge topic");
        return;
    }
 
    if (ast_unreal_channel_push_to_bridge(record_channel, bridge,
        AST_BRIDGE_CHANNEL_FLAG_IMMOVABLE | AST_BRIDGE_CHANNEL_FLAG_LONELY)) {
        ast_ari_response_error(
            response, 500, "Internal Error", "Failed to put recording channel into the bridge");
        return;
    }
 
    control = stasis_app_control_create(record_channel);
    if (control == NULL) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    options = stasis_app_recording_options_create(args->name, args->format);
    if (options == NULL) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    ast_string_field_build(options, target, "bridge:%s", args->bridge_id);
    options->max_silence_seconds = args->max_silence_seconds;
    options->max_duration_seconds = args->max_duration_seconds;
    options->terminate_on =
        stasis_app_recording_termination_parse(args->terminate_on);
    options->if_exists =
        stasis_app_recording_if_exists_parse(args->if_exists);
    options->beep = args->beep;
 
    if (options->terminate_on == STASIS_APP_RECORDING_TERMINATE_INVALID) {
        ast_ari_response_error(
            response, 400, "Bad Request",
            "terminateOn invalid");
        return;
    }
 
    if (options->if_exists == AST_RECORD_IF_EXISTS_ERROR) {
        ast_ari_response_error(
            response, 400, "Bad Request",
            "ifExists invalid");
        return;
    }
 
    recording = stasis_app_control_record(control, options);
    if (recording == NULL) {
        switch(errno) {
        case EINVAL:
            /* While the arguments are invalid, we should have
             * caught them prior to calling record.
             */
            ast_ari_response_error(
                response, 500, "Internal Server Error",
                "Error parsing request");
            break;
        case EEXIST:
            ast_ari_response_error(response, 409, "Conflict",
                "Recording '%s' already exists and can not be overwritten",
                args->name);
            break;
        case ENOMEM:
            ast_ari_response_alloc_failed(response);
            break;
        case EPERM:
            ast_ari_response_error(
                response, 400, "Bad Request",
                "Recording name invalid");
            break;
        default:
            ast_log(LOG_WARNING,
                "Unrecognized recording error: %s\n",
                strerror(errno));
            ast_ari_response_error(
                response, 500, "Internal Server Error",
                "Internal Server Error");
            break;
        }
        return;
    }
 
    uri_name_maxlen = strlen(args->name) * 3;
    uri_encoded_name = ast_malloc(uri_name_maxlen);
    if (!uri_encoded_name) {
        ast_ari_response_alloc_failed(response);
        return;
    }
    ast_uri_encode(args->name, uri_encoded_name, uri_name_maxlen, ast_uri_http);
 
    if (ast_asprintf(&recording_url, "/recordings/live/%s",
            uri_encoded_name) == -1) {
        recording_url = NULL;
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    json = stasis_app_recording_to_json(recording);
    if (!json) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    thread_data = ast_calloc(1, sizeof(*thread_data));
    if (!thread_data) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    thread_data->bridge_channel = record_channel;
    thread_data->control = control;
    thread_data->forward = channel_forward;
 
    if (ast_pthread_create_detached(&threadid, NULL, bridge_channel_control_thread, thread_data)) {
        ast_ari_response_alloc_failed(response);
        ast_free(thread_data);
        return;
    }
 
    /* These are owned by the other thread now, so we don't want RAII_VAR disposing of them. */
    record_channel = NULL;
    control = NULL;
    channel_forward = NULL;
 
    ast_ari_response_created(response, recording_url, ast_json_ref(json));
}
 
void ast_ari_bridges_start_moh(struct ast_variable *headers,
    struct ast_ari_bridges_start_moh_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, find_bridge(response, args->bridge_id), ao2_cleanup);
    struct ast_channel *moh_channel;
    const char *moh_class = args->moh_class;
 
    if (!bridge) {
        /* The response is provided by find_bridge() */
        return;
    }
 
    moh_channel = stasis_app_bridge_moh_channel(bridge);
    if (!moh_channel) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    ast_moh_start(moh_channel, moh_class, NULL);
    ast_channel_cleanup(moh_channel);
 
    ast_ari_response_no_content(response);
 
}
 
void ast_ari_bridges_stop_moh(struct ast_variable *headers,
    struct ast_ari_bridges_stop_moh_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, find_bridge(response, args->bridge_id), ao2_cleanup);
 
    if (!bridge) {
        /* the response is provided by find_bridge() */
        return;
    }
 
    if (stasis_app_bridge_moh_stop(bridge)) {
        ast_ari_response_error(
            response, 409, "Conflict",
            "Bridge isn't playing music");
        return;
    }
 
    ast_ari_response_no_content(response);
}
 
void ast_ari_bridges_get(struct ast_variable *headers,
    struct ast_ari_bridges_get_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge_snapshot *, snapshot, ast_bridge_get_snapshot_by_uniqueid(args->bridge_id), ao2_cleanup);
    if (!snapshot) {
        ast_ari_response_error(
            response, 404, "Not Found",
            "Bridge not found");
        return;
    }
 
    ast_ari_response_ok(response,
        ast_bridge_snapshot_to_json(snapshot, stasis_app_get_sanitizer()));
}
 
void ast_ari_bridges_destroy(struct ast_variable *headers,
    struct ast_ari_bridges_destroy_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, find_bridge(response, args->bridge_id), ao2_cleanup);
    if (!bridge) {
        return;
    }
 
    stasis_app_bridge_destroy(args->bridge_id);
    ast_ari_response_no_content(response);
}
 
void ast_ari_bridges_list(struct ast_variable *headers,
    struct ast_ari_bridges_list_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ao2_container *, bridges, NULL, ao2_cleanup);
    RAII_VAR(struct ast_json *, json, NULL, ast_json_unref);
    struct ao2_iterator i;
    struct ast_bridge *bridge;
 
    bridges = ast_bridges();
    if (!bridges) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    json = ast_json_array_create();
    if (!json) {
        ast_ari_response_alloc_failed(response);
        return;
    }
 
    i = ao2_iterator_init(bridges, 0);
    while ((bridge = ao2_iterator_next(&i))) {
        struct ast_bridge_snapshot *snapshot;
        struct ast_json *json_bridge = NULL;
 
        /* Invisible bridges don't get shown externally and have no snapshot */
        if (ast_test_flag(&bridge->feature_flags, AST_BRIDGE_FLAG_INVISIBLE)) {
            ao2_ref(bridge, -1);
            continue;
        }
 
        snapshot = ast_bridge_get_snapshot(bridge);
        if (snapshot) {
            json_bridge = ast_bridge_snapshot_to_json(snapshot, stasis_app_get_sanitizer());
            ao2_ref(snapshot, -1);
        }
 
        ao2_ref(bridge, -1);
 
        if (!json_bridge || ast_json_array_append(json, json_bridge)) {
            ao2_iterator_destroy(&i);
            ast_ari_response_alloc_failed(response);
            return;
        }
    }
    ao2_iterator_destroy(&i);
 
    ast_ari_response_ok(response, ast_json_ref(json));
}
 
void ast_ari_bridges_create(struct ast_variable *headers,
    struct ast_ari_bridges_create_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, NULL, ao2_cleanup);
    RAII_VAR(struct ast_bridge_snapshot *, snapshot, NULL, ao2_cleanup);
 
    if (ast_bridge_topic_exists(args->bridge_id)) {
        ast_ari_response_error(
            response, 409, "Conflict",
            "Bridge with id '%s' already exists", args->bridge_id);
        return;
    }
 
    bridge = stasis_app_bridge_create(args->type, args->name, args->bridge_id);
    if (!bridge) {
        ast_ari_response_error(
            response, 500, "Internal Error",
            "Unable to create bridge. Possible duplicate bridge id '%s'", args->bridge_id);
        return;
    }
 
    ast_bridge_lock(bridge);
    snapshot = ast_bridge_snapshot_create(bridge);
    ast_bridge_unlock(bridge);
 
    if (!snapshot) {
        ast_ari_response_error(
            response, 500, "Internal Error",
            "Unable to create snapshot for new bridge");
        return;
    }
 
    ast_ari_response_ok(response,
        ast_bridge_snapshot_to_json(snapshot, stasis_app_get_sanitizer()));
}
 
void ast_ari_bridges_create_with_id(struct ast_variable *headers,
    struct ast_ari_bridges_create_with_id_args *args,
    struct ast_ari_response *response)
{
    RAII_VAR(struct ast_bridge *, bridge, NULL, ao2_cleanup);
    RAII_VAR(struct ast_bridge_snapshot *, snapshot, NULL, ao2_cleanup);
 
    if (ast_bridge_topic_exists(args->bridge_id)) {
        ast_ari_response_error(
            response, 409, "Conflict",
            "Bridge with id '%s' already exists", args->bridge_id);
        return;
    }
 
    bridge = stasis_app_bridge_create(args->type, args->name, args->bridge_id);
    if (!bridge) {
        ast_ari_response_error(
            response, 500, "Internal Error",
            "Unable to create bridge");
        return;
    }
 
    ast_bridge_lock(bridge);
    snapshot = ast_bridge_snapshot_create(bridge);
    ast_bridge_unlock(bridge);
 
    if (!snapshot) {
        ast_ari_response_error(
            response, 500, "Internal Error",
            "Unable to create snapshot for new bridge");
        return;
    }
 
    ast_ari_response_ok(response,
        ast_bridge_snapshot_to_json(snapshot, stasis_app_get_sanitizer()));
}
 
static int bridge_set_video_source_cb(struct stasis_app_control *control,
    struct ast_channel *chan, void *data)
{
    struct ast_bridge *bridge = data;
 
    ast_bridge_lock(bridge);
    ast_bridge_set_single_src_video_mode(bridge, chan);
    ast_bridge_unlock(bridge);
 
    return 0;
}
 
void ast_ari_bridges_set_video_source(struct ast_variable *headers,
    struct ast_ari_bridges_set_video_source_args *args, struct ast_ari_response *response)
{
    struct ast_bridge *bridge;
    struct stasis_app_control *control;
 
    bridge = find_bridge(response, args->bridge_id);
    if (!bridge) {
        return;
    }
 
    control = find_channel_control(response, args->channel_id);
    if (!control) {
        ao2_ref(bridge, -1);
        return;
    }
 
    if (stasis_app_get_bridge(control) != bridge) {
        ast_ari_response_error(response, 422,
            "Unprocessable Entity",
            "Channel not in this bridge");
        ao2_ref(bridge, -1);
        ao2_ref(control, -1);
        return;
    }
 
    stasis_app_send_command(control, bridge_set_video_source_cb,
        ao2_bump(bridge), __ao2_cleanup);
 
    ao2_ref(bridge, -1);
    ao2_ref(control, -1);
 
    ast_ari_response_no_content(response);
}
 
void ast_ari_bridges_clear_video_source(struct ast_variable *headers,
    struct ast_ari_bridges_clear_video_source_args *args, struct ast_ari_response *response)
{
    struct ast_bridge *bridge;
 
    bridge = find_bridge(response, args->bridge_id);
    if (!bridge) {
        return;
    }
 
    ast_bridge_lock(bridge);
    ast_bridge_set_talker_src_video_mode(bridge);
    ast_bridge_unlock(bridge);
 
    ao2_ref(bridge, -1);
    ast_ari_response_no_content(response);
}