func_hangupcause.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999-2012, 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 Functions related to retreiving per-channel hangupcause information
 *
 * \author Kinsey Moore <[email protected]>
 * \ingroup functions
 *
 * See Also:
 * \arg \ref AstCREDITS
 */

/*** 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/app.h"

/*** DOCUMENTATION
   <function name="HANGUPCAUSE" language="en_US">
      <synopsis>
         Gets per-channel hangupcause information from the channel.
      </synopsis>
      <syntax>
         <parameter name="channel" required="true">
            <para>The name of the channel for which to retrieve cause information.</para>
         </parameter>
         <parameter name="type" required="true">
            <para>Parameter describing which type of information is requested. Types are:</para>
            <enumlist>
               <enum name="tech"><para>Technology-specific cause information</para></enum>
               <enum name="ast"><para>Translated Asterisk cause code</para></enum>
            </enumlist>
         </parameter>
      </syntax>
      <description>
         <para>Gets technology-specific or translated Asterisk cause code information
         from the channel for the specified channel that resulted from a dial.</para>
      </description>
      <see-also>
         <ref type="function">HANGUPCAUSE_KEYS</ref>
         <ref type="application">HangupCauseClear</ref>
      </see-also>
   </function>
   <function name="HANGUPCAUSE_KEYS" language="en_US">
      <synopsis>
         Gets the list of channels for which hangup causes are available.
      </synopsis>
      <description>
         <para>Returns a comma-separated list of channel names to be used with the HANGUPCAUSE function.</para>
      </description>
      <see-also>
         <ref type="function">HANGUPCAUSE</ref>
         <ref type="application">HangupCauseClear</ref>
      </see-also>
   </function>
   <application name="HangupCauseClear" language="en_US">
      <synopsis>
         Clears hangup cause information from the channel that is available through HANGUPCAUSE.
      </synopsis>
      <description>
         <para>Clears all channel-specific hangup cause information from the channel.
         This is never done automatically (i.e. for new Dial()s).</para>
      </description>
      <see-also>
         <ref type="function">HANGUPCAUSE</ref>
         <ref type="function">HANGUPCAUSE_KEYS</ref>
      </see-also>
   </application>
 ***/

/*!
 * \internal
 * \brief Read values from the hangupcause ao2 container.
 *
 * \param chan Asterisk channel to read
 * \param cmd Not used
 * \param data HANGUPCAUSE function argument string
 * \param buf Buffer to fill with read value.
 * \param len Length of the buffer
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int hangupcause_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
   char *parms;
   struct ast_control_pvt_cause_code *cause_code;
   int res = 0;
   AST_DECLARE_APP_ARGS(args,
      AST_APP_ARG(channel);   /*!< Channel name */
      AST_APP_ARG(type);   /*!< Type of information requested (ast or tech) */
      );

   /* Ensure that the buffer is empty */
   *buf = 0;

   if (!chan) {
      return -1;
   }

   parms = ast_strdupa(data);
   AST_STANDARD_APP_ARGS(args, parms);
   if (args.argc != 2) {
      /* Must have two arguments. */
      ast_log(LOG_WARNING, "The HANGUPCAUSE function must have 2 parameters, not %u\n", args.argc);
      return -1;
   }

   ast_channel_lock(chan);
   cause_code = ast_channel_dialed_causes_find(chan, args.channel);
   ast_channel_unlock(chan);

   if (!cause_code) {
      ast_log(LOG_WARNING, "Unable to find information for channel %s\n", args.channel);
      return -1;
   }

   if (!strcmp(args.type, "ast")) {
      ast_copy_string(buf, ast_cause2str(cause_code->ast_cause), len);
   } else if (!strcmp(args.type, "tech")) {
      ast_copy_string(buf, cause_code->code, len);
   } else {
      ast_log(LOG_WARNING, "Information type not recognized (%s)\n", args.type);
      res = -1;
   }

   ao2_ref(cause_code, -1);

   return res;
}

/*!
 * \internal
 * \brief Read keys from the hangupcause ao2 container.
 *
 * \param chan Asterisk channel to read
 * \param cmd Not used
 * \param data HANGUPCAUSE_KEYS function argument string
 * \param buf Buffer to fill with read value.
 * \param len Length of the buffer
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int hangupcause_keys_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
{
   struct ast_str *chanlist;

   /* Ensure that the buffer is empty */
   *buf = 0;

   if (!chan) {
      return -1;
   }

   ast_channel_lock(chan);
   chanlist = ast_channel_dialed_causes_channels(chan);
   ast_channel_unlock(chan);

   if (chanlist && ast_str_strlen(chanlist)) {
      ast_copy_string(buf, ast_str_buffer(chanlist), len);
   }

   ast_free(chanlist);
   return 0;
}

/*!
 * \internal
 * \brief Remove all keys from the hangupcause ao2 container.
 *
 * \param chan Asterisk channel to read
 * \param data Not used
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int hangupcause_clear_exec(struct ast_channel *chan, const char *data) {
   ast_channel_lock(chan);
   ast_channel_dialed_causes_clear(chan);
   ast_channel_unlock(chan);
   return 0;
}

static struct ast_custom_function hangupcause_function = {
   .name = "HANGUPCAUSE",
   .read = hangupcause_read,
};

static struct ast_custom_function hangupcause_keys_function = {
   .name = "HANGUPCAUSE_KEYS",
   .read = hangupcause_keys_read,
};

static const char app[] = "HangupCauseClear";

/*!
 * \internal
 * \brief Unload the function module
 *
 * \retval 0 on success.
 * \retval -1 on error.
 */
static int unload_module(void)
{
   int res;

   res = ast_custom_function_unregister(&hangupcause_function);
   res |= ast_custom_function_unregister(&hangupcause_keys_function);
   res |= ast_unregister_application(app);
   return res;
}

/*!
 * \internal
 * \brief Load and initialize the function module.
 *
 * \retval AST_MODULE_LOAD_SUCCESS on success.
 * \retval AST_MODULE_LOAD_DECLINE on error.
 */
static int load_module(void)
{
   int res;

   res = ast_custom_function_register(&hangupcause_function);
   res |= ast_custom_function_register(&hangupcause_keys_function);
   res |= ast_register_application_xml(app, hangupcause_clear_exec);
   return res ? AST_MODULE_LOAD_DECLINE : AST_MODULE_LOAD_SUCCESS;
}

/* Do not wrap the following line. */
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "HANGUPCAUSE related functions and applications");