manager_bridges.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Kinsey Moore <[email protected]>
 *
 * 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 The Asterisk Management Interface - AMI (bridge event handling)
 *
 * \author Kinsey Moore <[email protected]>
 */

#include "asterisk.h"

#include "asterisk/stasis_bridges.h"
#include "asterisk/stasis_channels.h"
#include "asterisk/manager.h"
#include "asterisk/stasis_message_router.h"

/*! \brief Message router for cached bridge state snapshot updates */
static struct stasis_message_router *bridge_state_router;

/*** DOCUMENTATION
   <managerEvent language="en_US" name="BridgeCreate">
      <managerEventInstance class="EVENT_FLAG_CALL">
         <synopsis>Raised when a bridge is created.</synopsis>
         <syntax>
            <bridge_snapshot/>
         </syntax>
         <see-also>
            <ref type="managerEvent">BridgeDestroy</ref>
            <ref type="managerEvent">BridgeEnter</ref>
            <ref type="managerEvent">BridgeLeave</ref>
         </see-also>
      </managerEventInstance>
   </managerEvent>
   <managerEvent language="en_US" name="BridgeDestroy">
      <managerEventInstance class="EVENT_FLAG_CALL">
         <synopsis>Raised when a bridge is destroyed.</synopsis>
         <syntax>
            <bridge_snapshot/>
         </syntax>
         <see-also>
            <ref type="managerEvent">BridgeCreate</ref>
            <ref type="managerEvent">BridgeEnter</ref>
            <ref type="managerEvent">BridgeLeave</ref>
         </see-also>
      </managerEventInstance>
   </managerEvent>
   <managerEvent language="en_US" name="BridgeEnter">
      <managerEventInstance class="EVENT_FLAG_CALL">
         <synopsis>Raised when a channel enters a bridge.</synopsis>
         <syntax>
            <bridge_snapshot/>
            <channel_snapshot/>
            <parameter name="SwapUniqueid">
               <para>The uniqueid of the channel being swapped out of the bridge</para>
            </parameter>
         </syntax>
         <see-also>
            <ref type="managerEvent">BridgeCreate</ref>
            <ref type="managerEvent">BridgeDestroy</ref>
            <ref type="managerEvent">BridgeLeave</ref>
         </see-also>
      </managerEventInstance>
   </managerEvent>
   <managerEvent language="en_US" name="BridgeLeave">
      <managerEventInstance class="EVENT_FLAG_CALL">
         <synopsis>Raised when a channel leaves a bridge.</synopsis>
         <syntax>
            <bridge_snapshot/>
            <channel_snapshot/>
         </syntax>
         <see-also>
            <ref type="managerEvent">BridgeCreate</ref>
            <ref type="managerEvent">BridgeDestroy</ref>
            <ref type="managerEvent">BridgeEnter</ref>
         </see-also>
      </managerEventInstance>
   </managerEvent>
   <managerEvent language="en_US" name="BridgeVideoSourceUpdate">
      <managerEventInstance class="EVENT_FLAG_CALL">
         <synopsis>Raised when the channel that is the source of video in a bridge changes.</synopsis>
         <syntax>
            <bridge_snapshot/>
            <parameter name="BridgePreviousVideoSource">
               <para>The unique ID of the channel that was the video source.</para>
            </parameter>
         </syntax>
         <see-also>
            <ref type="managerEvent">BridgeCreate</ref>
            <ref type="managerEvent">BridgeDestroy</ref>
         </see-also>
      </managerEventInstance>
   </managerEvent>
   <manager name="BridgeList" language="en_US">
      <synopsis>
         Get a list of bridges in the system.
      </synopsis>
      <syntax>
         <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
         <parameter name="BridgeType">
            <para>Optional type for filtering the resulting list of bridges.</para>
         </parameter>
      </syntax>
      <description>
         <para>Returns a list of bridges, optionally filtering on a bridge type.</para>
      </description>
      <see-also>
         <ref type="manager">Bridge</ref>
         <ref type="manager">BridgeDestroy</ref>
         <ref type="manager">BridgeInfo</ref>
         <ref type="manager">BridgeKick</ref>
      </see-also>
   </manager>
   <manager name="BridgeInfo" language="en_US">
      <synopsis>
         Get information about a bridge.
      </synopsis>
      <syntax>
         <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
         <parameter name="BridgeUniqueid" required="true">
            <para>The unique ID of the bridge about which to retrieve information.</para>
         </parameter>
      </syntax>
      <description>
         <para>Returns detailed information about a bridge and the channels in it.</para>
      </description>
      <see-also>
         <ref type="manager">Bridge</ref>
         <ref type="manager">BridgeDestroy</ref>
         <ref type="manager">BridgeKick</ref>
         <ref type="manager">BridgeList</ref>
      </see-also>
      <responses>
         <list-elements>
            <managerEvent language="en_US" name="BridgeInfoChannel">
               <managerEventInstance class="EVENT_FLAG_COMMAND">
                  <synopsis>Information about a channel in a bridge.</synopsis>
                  <syntax>
                     <channel_snapshot/>
                  </syntax>
               </managerEventInstance>
            </managerEvent>
         </list-elements>
         <managerEvent language="en_US" name="BridgeInfoComplete">
            <managerEventInstance class="EVENT_FLAG_COMMAND">
               <synopsis>Information about a bridge.</synopsis>
               <syntax>
                  <bridge_snapshot/>
               </syntax>
            </managerEventInstance>
         </managerEvent>
      </responses>
   </manager>
   <manager name="BridgeDestroy" language="en_US">
      <synopsis>
         Destroy a bridge.
      </synopsis>
      <syntax>
         <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
         <parameter name="BridgeUniqueid" required="true">
            <para>The unique ID of the bridge to destroy.</para>
         </parameter>
      </syntax>
      <description>
         <para>Deletes the bridge, causing channels to continue or hang up.</para>
      </description>
      <see-also>
         <ref type="manager">Bridge</ref>
         <ref type="manager">BridgeInfo</ref>
         <ref type="manager">BridgeKick</ref>
         <ref type="manager">BridgeList</ref>
         <ref type="managerEvent">BridgeDestroy</ref>
      </see-also>
   </manager>
   <manager name="BridgeKick" language="en_US">
      <synopsis>
         Kick a channel from a bridge.
      </synopsis>
      <syntax>
         <xi:include xpointer="xpointer(/docs/manager[@name='Login']/syntax/parameter[@name='ActionID'])" />
         <parameter name="BridgeUniqueid" required="false">
            <para>The unique ID of the bridge containing the channel to
            destroy.  This parameter can be omitted, or supplied to insure
            that the channel is not removed from the wrong bridge.</para>
         </parameter>
         <parameter name="Channel" required="true">
            <para>The channel to kick out of a bridge.</para>
         </parameter>
      </syntax>
      <description>
         <para>The channel is removed from the bridge.</para>
      </description>
      <see-also>
         <ref type="manager">Bridge</ref>
         <ref type="manager">BridgeDestroy</ref>
         <ref type="manager">BridgeInfo</ref>
         <ref type="manager">BridgeList</ref>
         <ref type="managerEvent">BridgeLeave</ref>
      </see-also>
   </manager>
 ***/

/*! \brief The \ref stasis subscription returned by the forwarding of the channel topic
 * to the manager topic
 */
static struct stasis_forward *topic_forwarder;

struct ast_str *ast_manager_build_bridge_state_string_prefix(
   const struct ast_bridge_snapshot *snapshot,
   const char *prefix)
{
   struct ast_str *out = ast_str_create(128);
   int res;

   if (!out) {
      return NULL;
   }

   res = ast_str_set(&out, 0,
      "%sBridgeUniqueid: %s\r\n"
      "%sBridgeType: %s\r\n"
      "%sBridgeTechnology: %s\r\n"
      "%sBridgeCreator: %s\r\n"
      "%sBridgeName: %s\r\n"
      "%sBridgeNumChannels: %u\r\n"
      "%sBridgeVideoSourceMode: %s\r\n",
      prefix, snapshot->uniqueid,
      prefix, snapshot->subclass,
      prefix, snapshot->technology,
      prefix, ast_strlen_zero(snapshot->creator) ? "<unknown>": snapshot->creator,
      prefix, ast_strlen_zero(snapshot->name) ? "<unknown>": snapshot->name,
      prefix, snapshot->num_channels,
      prefix, ast_bridge_video_mode_to_string(snapshot->video_mode));
   if (!res) {
      ast_free(out);
      return NULL;
   }

   if (snapshot->video_mode != AST_BRIDGE_VIDEO_MODE_NONE
      && !ast_strlen_zero(snapshot->video_source_id)) {
      res = ast_str_append(&out, 0, "%sBridgeVideoSource: %s\r\n",
         prefix, snapshot->video_source_id);
      if (!res) {
         ast_free(out);
         return NULL;
      }
   }

   return out;
}

struct ast_str *ast_manager_build_bridge_state_string(
   const struct ast_bridge_snapshot *snapshot)
{
   return ast_manager_build_bridge_state_string_prefix(snapshot, "");
}

/*! \brief Typedef for callbacks that get called on channel snapshot updates */
typedef struct ast_manager_event_blob *(*bridge_snapshot_monitor)(
   struct ast_bridge_snapshot *old_snapshot,
   struct ast_bridge_snapshot *new_snapshot);

/*! \brief Handle bridge creation */
static struct ast_manager_event_blob *bridge_create(
   struct ast_bridge_snapshot *old_snapshot,
   struct ast_bridge_snapshot *new_snapshot)
{
   if (!new_snapshot || old_snapshot) {
      return NULL;
   }

   return ast_manager_event_blob_create(
      EVENT_FLAG_CALL, "BridgeCreate", NO_EXTRA_FIELDS);
}

/* \brief Handle video source updates */
static struct ast_manager_event_blob *bridge_video_update(
   struct ast_bridge_snapshot *old_snapshot,
   struct ast_bridge_snapshot *new_snapshot)
{
   if (!new_snapshot || !old_snapshot) {
      return NULL;
   }

   if (!strcmp(old_snapshot->video_source_id, new_snapshot->video_source_id)) {
      return NULL;
   }

   return ast_manager_event_blob_create(
      EVENT_FLAG_CALL, "BridgeVideoSourceUpdate",
      "BridgePreviousVideoSource: %s\r\n",
      old_snapshot->video_source_id);
}

/*! \brief Handle bridge destruction */
static struct ast_manager_event_blob *bridge_destroy(
   struct ast_bridge_snapshot *old_snapshot,
   struct ast_bridge_snapshot *new_snapshot)
{
   if (new_snapshot || !old_snapshot) {
      return NULL;
   }

   return ast_manager_event_blob_create(
      EVENT_FLAG_CALL, "BridgeDestroy", NO_EXTRA_FIELDS);
}

bridge_snapshot_monitor bridge_monitors[] = {
   bridge_create,
   bridge_video_update,
   bridge_destroy,
};

static void bridge_snapshot_update(void *data, struct stasis_subscription *sub,
                struct stasis_message *message)
{
   RAII_VAR(struct ast_str *, bridge_event_string, NULL, ast_free);
   struct ast_bridge_snapshot_update *update;
   size_t i;

   update = stasis_message_data(message);

   for (i = 0; i < ARRAY_LEN(bridge_monitors); ++i) {
      RAII_VAR(struct ast_manager_event_blob *, event, NULL, ao2_cleanup);

      event = bridge_monitors[i](update->old_snapshot, update->new_snapshot);
      if (!event) {
         continue;
      }

      /* If we haven't already, build the channel event string */
      if (!bridge_event_string) {
         bridge_event_string =
            ast_manager_build_bridge_state_string(
               update->new_snapshot ? update->new_snapshot : update->old_snapshot);
         if (!bridge_event_string) {
            return;
         }
      }

      manager_event(event->event_flags, event->manager_event, "%s%s",
         ast_str_buffer(bridge_event_string),
         event->extra_fields);
   }
}

static void bridge_merge_cb(void *data, struct stasis_subscription *sub,
                struct stasis_message *message)
{
   struct ast_bridge_merge_message *merge_msg = stasis_message_data(message);
   RAII_VAR(struct ast_str *, to_text, NULL, ast_free);
   RAII_VAR(struct ast_str *, from_text, NULL, ast_free);

   ast_assert(merge_msg->to != NULL);
   ast_assert(merge_msg->from != NULL);

   to_text = ast_manager_build_bridge_state_string_prefix(merge_msg->to, "To");
   from_text = ast_manager_build_bridge_state_string_prefix(merge_msg->from, "From");
   if (!to_text || !from_text) {
      return;
   }

   /*** DOCUMENTATION
      <managerEventInstance>
         <synopsis>Raised when two bridges are merged.</synopsis>
         <syntax>
            <bridge_snapshot prefix="To"/>
            <bridge_snapshot prefix="From"/>
         </syntax>
      </managerEventInstance>
   ***/
   manager_event(EVENT_FLAG_CALL, "BridgeMerge",
      "%s"
      "%s",
      ast_str_buffer(to_text),
      ast_str_buffer(from_text));
}

static void channel_enter_cb(void *data, struct stasis_subscription *sub,
                struct stasis_message *message)
{
   static const char *swap_name = "SwapUniqueid: ";
   struct ast_bridge_blob *blob = stasis_message_data(message);
   RAII_VAR(struct ast_str *, bridge_text, NULL, ast_free);
   RAII_VAR(struct ast_str *, channel_text, NULL, ast_free);
   const char *swap_id;

   bridge_text = ast_manager_build_bridge_state_string(blob->bridge);
   channel_text = ast_manager_build_channel_state_string(blob->channel);
   if (!bridge_text || !channel_text) {
      return;
   }

   swap_id = ast_json_string_get(ast_json_object_get(blob->blob, "swap"));

   manager_event(EVENT_FLAG_CALL, "BridgeEnter",
      "%s"
      "%s"
      "%s%s%s",
      ast_str_buffer(bridge_text),
      ast_str_buffer(channel_text),
      swap_id ? swap_name : "",
      S_OR(swap_id, ""),
      swap_id ? "\r\n" : "");
}

static void channel_leave_cb(void *data, struct stasis_subscription *sub,
                struct stasis_message *message)
{
   struct ast_bridge_blob *blob = stasis_message_data(message);
   RAII_VAR(struct ast_str *, bridge_text, NULL, ast_free);
   RAII_VAR(struct ast_str *, channel_text, NULL, ast_free);

   bridge_text = ast_manager_build_bridge_state_string(blob->bridge);
   channel_text = ast_manager_build_channel_state_string(blob->channel);
   if (!bridge_text || !channel_text) {
      return;
   }

   manager_event(EVENT_FLAG_CALL, "BridgeLeave",
      "%s"
      "%s",
      ast_str_buffer(bridge_text),
      ast_str_buffer(channel_text));
}

struct bridge_list_data {
   struct ast_str *id_text;
   const char *type_filter;
   int count;
};

static int send_bridge_list_item_cb(void *obj, void *arg, void *data, int flags)
{
   struct ast_bridge *bridge = obj;
   RAII_VAR(struct ast_bridge_snapshot *, snapshot, ast_bridge_get_snapshot(bridge), ao2_cleanup);
   struct mansession *s = arg;
   struct bridge_list_data *list_data = data;
   struct ast_str * bridge_info;

   if (!snapshot) {
      return 0;
   }

   if (!ast_strlen_zero(list_data->type_filter)
      && strcmp(list_data->type_filter, snapshot->technology)) {
      return 0;
   }

   bridge_info = ast_manager_build_bridge_state_string(snapshot);
   if (!bridge_info) {
      return 0;
   }

   astman_append(s,
      "Event: BridgeListItem\r\n"
      "%s"
      "%s"
      "\r\n",
      ast_str_buffer(list_data->id_text),
      ast_str_buffer(bridge_info));
   ++list_data->count;

   ast_free(bridge_info);

   return 0;
}

static int manager_bridges_list(struct mansession *s, const struct message *m)
{
   const char *id = astman_get_header(m, "ActionID");
   const char *type_filter = astman_get_header(m, "BridgeType");
   struct ao2_container *bridges;
   struct bridge_list_data list_data = { 0 };

   bridges = ast_bridges();
   if (!bridges) {
      astman_send_error(s, m, "Internal error");
      return -1;
   }

   list_data.id_text = ast_str_create(128);
   if (!list_data.id_text) {
      ao2_ref(bridges, -1);
      astman_send_error(s, m, "Internal error");
      return -1;
   }

   if (!ast_strlen_zero(id)) {
      ast_str_set(&list_data.id_text, 0, "ActionID: %s\r\n", id);
   }
   list_data.type_filter = type_filter;

   astman_send_listack(s, m, "Bridge listing will follow", "start");

   ao2_callback_data(bridges, OBJ_NODATA, send_bridge_list_item_cb, s, &list_data);

   astman_send_list_complete_start(s, m, "BridgeListComplete", list_data.count);
   astman_send_list_complete_end(s);

   ast_free(list_data.id_text);
   ao2_ref(bridges, -1);

   return 0;
}

static int send_bridge_info_item_cb(void *obj, void *arg, void *data, int flags)
{
   char *uniqueid = obj;
   struct mansession *s = arg;
   struct bridge_list_data *list_data = data;
   RAII_VAR(struct ast_channel_snapshot *, snapshot, NULL, ao2_cleanup);
   RAII_VAR(struct ast_str *, channel_text, NULL, ast_free);

   snapshot = ast_channel_snapshot_get_latest(uniqueid);
   if (!snapshot) {
      return 0;
   }

   if (snapshot->base->tech_properties & AST_CHAN_TP_INTERNAL) {
      return 0;
   }

   channel_text = ast_manager_build_channel_state_string(snapshot);
   if (!channel_text) {
      return 0;
   }

   astman_append(s,
      "Event: BridgeInfoChannel\r\n"
      "%s"
      "%s"
      "\r\n",
      ast_str_buffer(list_data->id_text),
      ast_str_buffer(channel_text));
   ++list_data->count;
   return 0;
}

static int manager_bridge_info(struct mansession *s, const struct message *m)
{
   const char *id = astman_get_header(m, "ActionID");
   const char *bridge_uniqueid = astman_get_header(m, "BridgeUniqueid");
   RAII_VAR(struct ast_str *, bridge_info, NULL, ast_free);
   RAII_VAR(struct ast_bridge_snapshot *, snapshot, NULL, ao2_cleanup);
   struct bridge_list_data list_data = { 0 };

   if (ast_strlen_zero(bridge_uniqueid)) {
      astman_send_error(s, m, "BridgeUniqueid must be provided");
      return 0;
   }

   snapshot = ast_bridge_get_snapshot_by_uniqueid(bridge_uniqueid);
   if (!snapshot) {
      astman_send_error(s, m, "Specified BridgeUniqueid not found");
      return 0;
   }

   bridge_info = ast_manager_build_bridge_state_string(snapshot);
   if (!bridge_info) {
      astman_send_error(s, m, "Internal error");
      return -1;
   }

   list_data.id_text = ast_str_create(128);
   if (!list_data.id_text) {
      astman_send_error(s, m, "Internal error");
      return -1;
   }

   if (!ast_strlen_zero(id)) {
      ast_str_set(&list_data.id_text, 0, "ActionID: %s\r\n", id);
   }

   astman_send_listack(s, m, "Bridge channel listing will follow", "start");

   ao2_callback_data(snapshot->channels, OBJ_NODATA, send_bridge_info_item_cb, s, &list_data);

   astman_send_list_complete_start(s, m, "BridgeInfoComplete", list_data.count);
   if (!ast_strlen_zero(ast_str_buffer(bridge_info))) {
      astman_append(s, "%s", ast_str_buffer(bridge_info));
   }
   astman_send_list_complete_end(s);
   ast_free(list_data.id_text);

   return 0;
}

static int manager_bridge_destroy(struct mansession *s, const struct message *m)
{
   const char *bridge_uniqueid = astman_get_header(m, "BridgeUniqueid");
   struct ast_bridge *bridge;

   if (ast_strlen_zero(bridge_uniqueid)) {
      astman_send_error(s, m, "BridgeUniqueid must be provided");
      return 0;
   }

   bridge = ast_bridge_find_by_id(bridge_uniqueid);
   if (!bridge) {
      astman_send_error(s, m, "Specified BridgeUniqueid not found");
      return 0;
   }
   ast_bridge_destroy(bridge, 0);

   astman_send_ack(s, m, "Bridge has been destroyed");

   return 0;
}

static int manager_bridge_kick(struct mansession *s, const struct message *m)
{
   const char *bridge_uniqueid = astman_get_header(m, "BridgeUniqueid");
   const char *channel_name = astman_get_header(m, "Channel");
   RAII_VAR(struct ast_bridge *, bridge, NULL, ao2_cleanup);
   RAII_VAR(struct ast_channel *, channel, NULL, ao2_cleanup);

   if (ast_strlen_zero(channel_name)) {
      astman_send_error(s, m, "Channel must be provided");
      return 0;
   }

   channel = ast_channel_get_by_name(channel_name);
   if (!channel) {
      astman_send_error(s, m, "Channel does not exist");
      return 0;
   }

   if (ast_strlen_zero(bridge_uniqueid)) {
      /* get the bridge from the channel */
      ast_channel_lock(channel);
      bridge = ast_channel_get_bridge(channel);
      ast_channel_unlock(channel);
      if (!bridge) {
         astman_send_error(s, m, "Channel is not in a bridge");
         return 0;
      }
   } else {
      bridge = ast_bridge_find_by_id(bridge_uniqueid);
      if (!bridge || ast_test_flag(&bridge->feature_flags, AST_BRIDGE_FLAG_INVISIBLE)) {
         astman_send_error(s, m, "Bridge not found");
         return 0;
      }
   }

   if (ast_bridge_kick(bridge, channel)) {
      astman_send_error(s, m, "Channel kick from bridge failed");
      return 0;
   }

   astman_send_ack(s, m, "Channel has been kicked");
   return 0;
}

static void manager_bridging_cleanup(void)
{
   stasis_forward_cancel(topic_forwarder);
   topic_forwarder = NULL;

   ast_manager_unregister("BridgeList");
   ast_manager_unregister("BridgeInfo");
   ast_manager_unregister("BridgeDestroy");
   ast_manager_unregister("BridgeKick");
}

int manager_bridging_init(void)
{
   int ret = 0;
   struct stasis_topic *manager_topic;
   struct stasis_topic *bridge_topic;

   if (bridge_state_router) {
      /* Already initialized */
      return 0;
   }

   ast_register_cleanup(manager_bridging_cleanup);

   manager_topic = ast_manager_get_topic();
   if (!manager_topic) {
      return -1;
   }

   bridge_topic = ast_bridge_topic_all();
   if (!bridge_topic) {
      return -1;
   }

   topic_forwarder = stasis_forward_all(bridge_topic, manager_topic);
   if (!topic_forwarder) {
      return -1;
   }

   bridge_state_router = ast_manager_get_message_router();
   if (!bridge_state_router) {
      return -1;
   }

   ret |= stasis_message_router_add(bridge_state_router,
      ast_bridge_snapshot_type(), bridge_snapshot_update, NULL);

   ret |= stasis_message_router_add(bridge_state_router,
      ast_bridge_merge_message_type(), bridge_merge_cb, NULL);

   ret |= stasis_message_router_add(bridge_state_router,
      ast_channel_entered_bridge_type(), channel_enter_cb, NULL);

   ret |= stasis_message_router_add(bridge_state_router,
      ast_channel_left_bridge_type(), channel_leave_cb, NULL);

   ret |= ast_manager_register_xml_core("BridgeList", 0, manager_bridges_list);
   ret |= ast_manager_register_xml_core("BridgeInfo", 0, manager_bridge_info);
   ret |= ast_manager_register_xml_core("BridgeDestroy", 0, manager_bridge_destroy);
   ret |= ast_manager_register_xml_core("BridgeKick", 0, manager_bridge_kick);

   /* If somehow we failed to add any routes, just shut down the whole
    * thing and fail it.
    */
   if (ret) {
      manager_bridging_cleanup();
      return -1;
   }

   return 0;
}