func_hangupcause.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999-2012, Digium, Inc.
 *
 * Kinsey Moore <kmoore@digium.com>
 *
 * 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 <kmoore@digium.com>
 * \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">
        <since>
            <version>11.0.0</version>
        </since>
        <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="tech_extended"><para>Technology-specific extended list of 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">
        <since>
            <version>11.0.0</version>
        </since>
        <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">
        <since>
            <version>11.0.0</version>
        </since>
        <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;
    struct ast_str *causelist;
    AST_DECLARE_APP_ARGS(args,
        AST_APP_ARG(channel);   /*!< Channel name */
        AST_APP_ARG(type);  /*!< Type of information requested (ast, tech or tech_extended) */
        );
 
    /* 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;
    }
 
    causelist = ast_str_create(128);
    if (!causelist) {
        ast_log(LOG_ERROR, "Unable to allocate buffer, cause information will be unavailable!\n");
        return -1;
    }
 
    ast_channel_lock(chan);
    if (!strcmp(args.type, "tech_extended")) {
        struct ao2_iterator *cause_codes;
        cause_codes = ast_channel_dialed_causes_find_multiple(chan, args.channel);
        while ((cause_code = ao2_iterator_next(cause_codes))) {
            if (!cause_code->cause_extended) {
                ao2_ref(cause_code, -1);
                continue;
            }
            ast_str_append(&causelist, 0, "%s%s", (ast_str_strlen(causelist) ? "," : ""), cause_code->code);
            ao2_ref(cause_code, -1);
        }
        ao2_iterator_destroy(cause_codes);
    } else {
        cause_code = ast_channel_dialed_causes_find(chan, args.channel);
        if (!cause_code) {
            ast_log(LOG_WARNING, "Unable to find information for channel '%s'\n", args.channel);
            ast_channel_unlock(chan);
            return -1;
        }
    }
    ast_channel_unlock(chan);
 
    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 if (!strcmp(args.type, "tech_extended")) {
        ast_copy_string(buf, ast_str_buffer(causelist), len);
    } else {
        ast_log(LOG_WARNING, "Information type not recognized (%s)\n", args.type);
        res = -1;
    }
 
    if (cause_code) {
        ao2_cleanup(cause_code);
    }
 
    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");