func_extstate.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2007, Digium, Inc.
 *
 * Modified from func_devstate.c by Russell Bryant <[email protected]>
 * Adam Gundy <[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 Get the state of a hinted extension for dialplan control
 *
 * \author Adam Gundy <[email protected]>
 *
 * \ingroup functions
 */

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

#include "asterisk.h"

#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/utils.h"
#include "asterisk/devicestate.h"

/*** DOCUMENTATION
   <function name="EXTENSION_STATE" language="en_US">
      <synopsis>
         Get an extension's state.
      </synopsis>
      <syntax argsep="@">
         <parameter name="extension" required="true" />
         <parameter name="context">
            <para>If it is not specified defaults to <literal>default</literal>.</para>
         </parameter>
      </syntax>
      <description>
         <para>The EXTENSION_STATE function can be used to retrieve the state from any
         hinted extension. For example:</para>
         <para>NoOp(1234@default has state ${EXTENSION_STATE(1234)})</para>
         <para>NoOp(4567@home has state ${EXTENSION_STATE(4567@home)})</para>
         <para>The possible values returned by this function are:</para>
         <para>UNKNOWN | NOT_INUSE | INUSE | BUSY | INVALID | UNAVAILABLE | RINGING |
         RINGINUSE | HOLDINUSE | ONHOLD</para>
      </description>
   </function>
 ***/

static const char *ast_extstate_str(int state)
{
   const char *res = "UNKNOWN";

   switch (state) {
   case AST_EXTENSION_NOT_INUSE:
      res = "NOT_INUSE";
      break;
   case AST_EXTENSION_INUSE:
      res = "INUSE";
      break;
   case AST_EXTENSION_BUSY:
      res = "BUSY";
      break;
   case AST_EXTENSION_UNAVAILABLE:
      res = "UNAVAILABLE";
      break;
   case AST_EXTENSION_RINGING:
      res = "RINGING";
      break;
   case AST_EXTENSION_INUSE | AST_EXTENSION_RINGING:
      res = "RINGINUSE";
      break;
   case AST_EXTENSION_INUSE | AST_EXTENSION_ONHOLD:
      res = "HOLDINUSE";
      break;
   case AST_EXTENSION_ONHOLD:
      res = "ONHOLD";
      break;
   }

   return res;
}

static int extstate_read(struct ast_channel *chan, const char *cmd, char *data,
   char *buf, size_t len)
{
   char *exten, *context;

   if (ast_strlen_zero(data)) {
      ast_log(LOG_WARNING, "EXTENSION_STATE requires an extension\n");
      return -1;
   }

   context = exten = data;
   strsep(&context, "@");
   if (ast_strlen_zero(context))
      context = "default";

   if (ast_strlen_zero(exten)) {
      ast_log(LOG_WARNING, "EXTENSION_STATE requires an extension\n");
      return -1;
   }

   ast_copy_string(buf,
      ast_extstate_str(ast_extension_state(chan, context, exten)), len);

   return 0;
}

static struct ast_custom_function extstate_function = {
   .name = "EXTENSION_STATE",
   .read = extstate_read,
   .read_max = 12,
};

static int unload_module(void)
{
   int res;

   res = ast_custom_function_unregister(&extstate_function);

   return res;
}

static int load_module(void)
{
   int res;

   res = ast_custom_function_register(&extstate_function);

   return res ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Gets an extension's state in the dialplan");