chan_bridge_media.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2013 Digium, Inc.
 *
 * Jonathan Rose <[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 Bridge Media Channels driver
 *
 * \author Jonathan Rose <[email protected]>
 * \author Richard Mudgett <[email protected]>
 *
 * \brief Bridge Media Channels
 *
 * \ingroup channel_drivers
 */

/*** MODULEINFO
   <support_level>core</support_level>
 ***/

#include "asterisk.h"

#include "asterisk/channel.h"
#include "asterisk/bridge.h"
#include "asterisk/core_unreal.h"
#include "asterisk/module.h"

static int media_call(struct ast_channel *chan, const char *addr, int timeout)
{
   /* ast_call() will fail unconditionally against channels provided by this driver */
   return -1;
}

static int media_hangup(struct ast_channel *ast)
{
   struct ast_unreal_pvt *p = ast_channel_tech_pvt(ast);
   int res;

   if (!p) {
      return -1;
   }

   /* Give the pvt a ref to fulfill calling requirements. */
   ao2_ref(p, +1);
   res = ast_unreal_hangup(p, ast);
   ao2_ref(p, -1);

   return res;
}

static struct ast_channel *announce_request(const char *type, struct ast_format_cap *cap,
   const struct ast_assigned_ids *assignedids, const struct ast_channel *requestor, const char *data, int *cause);

static struct ast_channel *record_request(const char *type, struct ast_format_cap *cap,
   const struct ast_assigned_ids *assignedids, const struct ast_channel *requestor, const char *data, int *cause);

static struct ast_channel_tech announce_tech = {
   .type = "Announcer",
   .description = "Bridge Media Announcing Channel Driver",
   .requester = announce_request,
   .call = media_call,
   .hangup = media_hangup,

   .send_digit_begin = ast_unreal_digit_begin,
   .send_digit_end = ast_unreal_digit_end,
   .read = ast_unreal_read,
   .write = ast_unreal_write,
   .write_video = ast_unreal_write,
   .exception = ast_unreal_read,
   .indicate = ast_unreal_indicate,
   .fixup = ast_unreal_fixup,
   .send_html = ast_unreal_sendhtml,
   .send_text = ast_unreal_sendtext,
   .queryoption = ast_unreal_queryoption,
   .setoption = ast_unreal_setoption,
   .properties = AST_CHAN_TP_INTERNAL,
};

static struct ast_channel_tech record_tech = {
   .type = "Recorder",
   .description = "Bridge Media Recording Channel Driver",
   .requester = record_request,
   .call = media_call,
   .hangup = media_hangup,

   .send_digit_begin = ast_unreal_digit_begin,
   .send_digit_end = ast_unreal_digit_end,
   .read = ast_unreal_read,
   .write = ast_unreal_write,
   .write_video = ast_unreal_write,
   .exception = ast_unreal_read,
   .indicate = ast_unreal_indicate,
   .fixup = ast_unreal_fixup,
   .send_html = ast_unreal_sendhtml,
   .send_text = ast_unreal_sendtext,
   .queryoption = ast_unreal_queryoption,
   .setoption = ast_unreal_setoption,
   .properties = AST_CHAN_TP_INTERNAL,
};

static struct ast_channel *media_request_helper(struct ast_format_cap *cap, const struct ast_assigned_ids *assignedids,
   const struct ast_channel *requestor, const char *data, struct ast_channel_tech *tech, const char *role)
{
   struct ast_channel *chan;
   ast_callid callid;

   RAII_VAR(struct ast_unreal_pvt *, pvt, NULL, ao2_cleanup);

   if (!(pvt = ast_unreal_alloc(sizeof(*pvt), ast_unreal_destructor, cap))) {
      return NULL;
   }

   ast_copy_string(pvt->name, data, sizeof(pvt->name));

   ast_set_flag(pvt, AST_UNREAL_NO_OPTIMIZATION);

   callid = ast_read_threadstorage_callid();

   chan = ast_unreal_new_channels(pvt, tech,
      AST_STATE_UP, AST_STATE_UP, NULL, NULL, assignedids, requestor, callid);
   if (!chan) {
      return NULL;
   }

   ast_answer(pvt->owner);
   ast_answer(pvt->chan);

   if (ast_channel_add_bridge_role(pvt->chan, role)) {
      ast_hangup(chan);
      return NULL;
   }

   return chan;
}

static struct ast_channel *announce_request(const char *type, struct ast_format_cap *cap,
   const struct ast_assigned_ids *assignedids, const struct ast_channel *requestor, const char *data, int *cause)
{
   return media_request_helper(cap, assignedids, requestor, data, &announce_tech, "announcer");
}

static struct ast_channel *record_request(const char *type, struct ast_format_cap *cap,
   const struct ast_assigned_ids *assignedids, const struct ast_channel *requestor, const char *data, int *cause)
{
   return media_request_helper(cap, assignedids, requestor, data, &record_tech, "recorder");
}

static void cleanup_capabilities(void)
{
   if (announce_tech.capabilities) {
      ao2_ref(announce_tech.capabilities, -1);
      announce_tech.capabilities = NULL;
   }

   if (record_tech.capabilities) {
      ao2_ref(record_tech.capabilities, -1);
      record_tech.capabilities = NULL;
   }
}

static int unload_module(void)
{
   ast_channel_unregister(&announce_tech);
   ast_channel_unregister(&record_tech);
   cleanup_capabilities();
   return 0;
}

static int load_module(void)
{
   announce_tech.capabilities = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
   if (!announce_tech.capabilities) {
      return AST_MODULE_LOAD_DECLINE;
   }

   record_tech.capabilities = ast_format_cap_alloc(AST_FORMAT_CAP_FLAG_DEFAULT);
   if (!record_tech.capabilities) {
      return AST_MODULE_LOAD_DECLINE;
   }

   ast_format_cap_append_by_type(announce_tech.capabilities, AST_MEDIA_TYPE_UNKNOWN);
   ast_format_cap_append_by_type(record_tech.capabilities, AST_MEDIA_TYPE_UNKNOWN);

   if (ast_channel_register(&announce_tech)) {
      ast_log(LOG_ERROR, "Unable to register channel technology %s(%s).\n",
         announce_tech.type, announce_tech.description);
      cleanup_capabilities();
      return AST_MODULE_LOAD_DECLINE;
   }

   if (ast_channel_register(&record_tech)) {
      ast_log(LOG_ERROR, "Unable to register channel technology %s(%s).\n",
         record_tech.type, record_tech.description);
      cleanup_capabilities();
      return AST_MODULE_LOAD_DECLINE;
   }

   return AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Bridge Media Channel Driver",
   .support_level = AST_MODULE_SUPPORT_CORE,
   .load = load_module,
   .unload = unload_module,
);