Skip to content
Snippets Groups Projects
app_attended_transfer.c 3.8 KiB
Newer Older
  • Learn to ignore specific revisions
  • /*
     * Asterisk -- An open source telephony toolkit.
     *
     * Copyright (C) 2019, Alexei Gradinari
     *
     * Alexei Gradinari <alex2grad@gmail.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 Attended transfer by caller channel
     *
     * \author Alexei Gradinari <alex2grad@gmail.com>
     *
     * \ingroup applications
     */
    
    /*** MODULEINFO
    	<support_level>extended</support_level>
     ***/
    
    #include "asterisk.h"
    
    #include "asterisk/pbx.h"
    #include "asterisk/module.h"
    #include "asterisk/app.h"
    #include "asterisk/channel.h"
    #include "asterisk/bridge.h"
    #include "asterisk/features_config.h"
    
    /*** DOCUMENTATION
    	<application name="AttendedTransfer" language="en_US">
    		<synopsis>
    			Attended transfer to the extension provided and TRANSFER_CONTEXT
    		</synopsis>
    		<syntax>
    			<parameter name="exten" required="true">
    				<para>Specify extension.</para>
    			</parameter>
    		</syntax>
    		<description>
    			<para>Queue up attended transfer to the specified extension in the <literal>TRANSFER_CONTEXT</literal>.</para>
    			<para>Note that the attended transfer only work when two channels have answered and are bridged together.</para>
    			<para>Make sure to set Attended Transfer DTMF feature <literal>atxfer</literal>
    			and attended transfer is permitted.</para>
    			<para>The result of the application will be reported in the <variable>ATTENDEDTRANSFERSTATUS</variable>
    			channel variable:</para>
    			<variablelist>
    				<variable name="ATTENDEDTRANSFERSTATUS">
    					<value name="SUCCESS">
    						Transfer successfully queued.
    					</value>
    					<value name="FAILURE">
    						Transfer failed.
    					</value>
    					<value name="NOTPERMITTED">
    						Transfer not permitted.
    					</value>
    				</variable>
    			</variablelist>
    		</description>
    	</application>
     ***/
    
    static const char * const app = "AttendedTransfer";
    
    static int attended_transfer_exec(struct ast_channel *chan, const char *data)
    {
    	char *exten = NULL;
    	const char *context = NULL;
    	char *parse;
    	AST_DECLARE_APP_ARGS(args,
    		AST_APP_ARG(exten);
    	);
    	char feature_code[AST_FEATURE_MAX_LEN];
    	const char *digit;
    	struct ast_frame f = { .frametype = AST_FRAME_DTMF };
    
    	if (ast_strlen_zero((char *)data)) {
    		ast_log(LOG_WARNING, "%s requires an argument (exten)\n", app);
    		pbx_builtin_setvar_helper(chan, "ATTENDEDTRANSFERSTATUS", "FAILURE");
    		return 0;
    	}
    
    	context = pbx_builtin_getvar_helper(chan, "TRANSFER_CONTEXT");
    	if (ast_strlen_zero(context)) {
    		pbx_builtin_setvar_helper(chan, "ATTENDEDTRANSFERSTATUS", "NOTPERMITTED");
    		return 0;
    	}
    
    	ast_channel_lock(chan);
    	if (ast_get_builtin_feature(chan, "atxfer", feature_code, sizeof(feature_code)) ||
    		ast_strlen_zero(feature_code)) {
    		pbx_builtin_setvar_helper(chan, "ATTENDEDTRANSFERSTATUS", "NOTPERMITTED");
    		ast_channel_unlock(chan);
    		return 0;
    	}
    	ast_channel_unlock(chan);
    
    	parse = ast_strdupa(data);
    	AST_STANDARD_APP_ARGS(args, parse);
    
    	exten = args.exten;
    
    	for (digit = feature_code; *digit; ++digit) {
    		f.subclass.integer = *digit;
    		ast_queue_frame(chan, &f);
    	}
    
    	for (digit = exten; *digit; ++digit) {
    		f.subclass.integer = *digit;
    		ast_queue_frame(chan, &f);
    	}
    
    	f.subclass.integer = '#';
    	ast_queue_frame(chan, &f);
    
    	pbx_builtin_setvar_helper(chan, "ATTENDEDTRANSFERSTATUS", "SUCCESS");
    
    	return 0;
    }
    
    static int unload_module(void)
    {
    	return ast_unregister_application(app);
    }
    
    static int load_module(void)
    {
    	return ast_register_application_xml(app, attended_transfer_exec);
    }
    
    AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Attended transfer to the given extension");