manager_mwi.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013, Digium, Inc.
 *
 * Matt Jordan <[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 (MWI event handling)
 *
 * \author Matt Jordan <[email protected]>
 */

#include "asterisk.h"

#include "asterisk/manager.h"
#include "asterisk/app.h"
#include "asterisk/mwi.h"
#include "asterisk/channel.h"
#include "asterisk/stasis_message_router.h"
#include "asterisk/stasis.h"

struct stasis_message_router *mwi_state_router;

/*** DOCUMENTATION
 ***/

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

/*! \brief Callback function used by \ref mwi_app_event_cb to weed out "Event" keys */
static int exclude_event_cb(const char *key)
{
   if (!strcmp(key, "Event")) {
      return -1;
   }
   return 0;
}

/*! \brief Generic MWI event callback used for one-off events from voicemail modules */
static void mwi_app_event_cb(void *data, struct stasis_subscription *sub,
                struct stasis_message *message)
{
   struct ast_mwi_blob *payload = stasis_message_data(message);
   RAII_VAR(struct ast_str *, channel_event_string, NULL, ast_free);
   RAII_VAR(struct ast_str *, event_buffer, NULL, ast_free);
   struct ast_json *event_json = ast_json_object_get(payload->blob, "Event");

   if (!event_json) {
      return;
   }

   if (payload->mwi_state && payload->mwi_state->snapshot) {
      channel_event_string = ast_manager_build_channel_state_string(payload->mwi_state->snapshot);
   }

   event_buffer = ast_manager_str_from_json_object(payload->blob, exclude_event_cb);
   if (!event_buffer) {
      ast_log(AST_LOG_WARNING, "Failed to create payload for event %s\n", ast_json_string_get(event_json));
      return;
   }

   manager_event(EVENT_FLAG_CALL, ast_json_string_get(event_json),
         "Mailbox: %s\r\n"
         "%s"
         "%s",
         payload->mwi_state ? payload->mwi_state->uniqueid : "Unknown",
         ast_str_buffer(event_buffer),
         channel_event_string ? ast_str_buffer(channel_event_string) : "");
}

static void mwi_update_cb(void *data, struct stasis_subscription *sub,
                struct stasis_message *message)
{
   struct ast_mwi_state *mwi_state;
   RAII_VAR(struct ast_str *, channel_event_string, NULL, ast_free);

   if (ast_mwi_state_type() != stasis_message_type(message)) {
      return;
   }

   mwi_state = stasis_message_data(message);
   if (!mwi_state) {
      return;
   }

   if (mwi_state->snapshot) {
      channel_event_string = ast_manager_build_channel_state_string(mwi_state->snapshot);
   }

   /*** DOCUMENTATION
      <managerEventInstance>
         <synopsis>Raised when the state of messages in a voicemail mailbox
         has changed or when a channel has finished interacting with a
         mailbox.</synopsis>
         <syntax>
            <channel_snapshot/>
            <parameter name="Mailbox">
               <para>The mailbox with the new message, specified as <literal>mailbox</literal>@<literal>context</literal></para>
            </parameter>
            <parameter name="Waiting">
               <para>Whether or not the mailbox has messages waiting for it.</para>
            </parameter>
            <parameter name="New">
               <para>The number of new messages.</para>
            </parameter>
            <parameter name="Old">
               <para>The number of old messages.</para>
            </parameter>
         </syntax>
         <description>
            <note><para>The Channel related parameters are only present if a
            channel was involved in the manipulation of a mailbox. If no
            channel is involved, the parameters are not included with the
            event.</para>
            </note>
         </description>
      </managerEventInstance>
   ***/
   manager_event(EVENT_FLAG_CALL, "MessageWaiting",
         "%s"
         "Mailbox: %s\r\n"
         "Waiting: %d\r\n"
         "New: %d\r\n"
         "Old: %d\r\n",
         AS_OR(channel_event_string, ""),
         mwi_state->uniqueid,
         ast_app_has_voicemail(mwi_state->uniqueid, NULL),
         mwi_state->new_msgs,
         mwi_state->old_msgs);
}

static void manager_mwi_shutdown(void)
{
   stasis_forward_cancel(topic_forwarder);
   topic_forwarder = NULL;
}

int manager_mwi_init(void)
{
   int ret = 0;
   struct stasis_topic *manager_topic;
   struct stasis_topic *mwi_topic;
   struct stasis_message_router *message_router;

   manager_topic = ast_manager_get_topic();
   if (!manager_topic) {
      return -1;
   }
   message_router = ast_manager_get_message_router();
   if (!message_router) {
      return -1;
   }
   mwi_topic = ast_mwi_topic_all();
   if (!mwi_topic) {
      return -1;
   }

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

   ast_register_cleanup(manager_mwi_shutdown);

   ret |= stasis_message_router_add(message_router,
                ast_mwi_state_type(),
                mwi_update_cb,
                NULL);

   ret |= stasis_message_router_add(message_router,
                ast_mwi_vm_app_type(),
                mwi_app_event_cb,
                NULL);

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

   return 0;
}