asterisk/funcs/func_dialplan.c
Tilghman Lesher 9af5c769c3 Enable macros in 1.8 to find the next highest "h" extension in a context, like in 1.4.
This change restores functionality that was present in 1.4, when AEL macros
were implemented with the Macro dialplan application.  Macros are fraught with
functionality issues, because they consume a large portion of the underlying
application stack.  This limits the ability of AEL users to call many layers
of subroutines, an issue which Gosub does not have (originally tested to
100,000 levels deep).  Therefore, starting in 1.6.0, AEL macros were
implemented with Gosub.

However, there were some implicit behaviors of Macro, which were not replicated
at the same time as with the transition to Gosub, one of which is documented in
the related issue.  In particular, the "h" extension is designed to execute not
in the Macro context, but in the topmost calling context.  Due to legacy issues
with a misapplied bugfix many years ago, when a macro exited in 1.4, it looks
in all calling contexts, bubbling up from the deepest level until it finds an
"h" extension.

Since AEL hides the complexity of the underlying dialplan logic from the AEL
programmer, it's reasonable to assume that this behavior should not change in
the transition from Asterisk 1.4 LTS to Asterisk 1.8 LTS, lest we break
working AEL configurations in the transition to Asterisk 1.8 LTS.  This fix
is the result, which implements a search for the "h" extension in all calling
Gosub contexts.

Fixes ASTERISK-19336

Patch: 20120308__ael_bugfix_for_trunk__2.diff (License #5003) by Tilghman Lesher
	(with slight modifications for 1.8)

Tested by: Johan Wilfer

Review: https://reviewboard.asterisk.org/r/1776/
........

Merged revisions 358810 from http://svn.asterisk.org/svn/asterisk/branches/1.8
........

Merged revisions 358811 from http://svn.asterisk.org/svn/asterisk/branches/10


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@358812 65c4cc65-6c06-0410-ace0-fbb531ad65f3
2012-03-13 08:06:20 +00:00

193 lines
5.3 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2007, Digium, Inc.
*
* 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 Dialplan group functions check if a dialplan entry exists
*
* \author Gregory Nietsky AKA irroot <gregory@networksentry.co.za>
* \author Russell Bryant <russell@digium.com>
*
* \ingroup functions
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"
/*** DOCUMENTATION
<function name="DIALPLAN_EXISTS" language="en_US">
<synopsis>
Checks the existence of a dialplan target.
</synopsis>
<syntax>
<parameter name="context" required="true" />
<parameter name="extension" />
<parameter name="priority" />
</syntax>
<description>
<para>This function returns <literal>1</literal> if the target exits. Otherwise, it returns <literal>0</literal>.</para>
</description>
</function>
<function name="VALID_EXTEN" language="en_US">
<synopsis>
Determine whether an extension exists or not.
</synopsis>
<syntax>
<parameter name="context">
<para>Defaults to the current context</para>
</parameter>
<parameter name="extension" required="true" />
<parameter name="priority">
<para>Priority defaults to <literal>1</literal>.</para>
</parameter>
</syntax>
<description>
<para>Returns a true value if the indicated <replaceable>context</replaceable>,
<replaceable>extension</replaceable>, and <replaceable>priority</replaceable> exist.</para>
<warning><para>This function has been deprecated in favor of the <literal>DIALPLAN_EXISTS()</literal> function</para></warning>
</description>
</function>
***/
static int isexten_function_read(struct ast_channel *chan, const char *cmd, char *data,
char *buf, size_t len)
{
char *parse;
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(context);
AST_APP_ARG(exten);
AST_APP_ARG(priority);
);
strcpy(buf, "0");
if (ast_strlen_zero(data)) {
ast_log(LOG_ERROR, "DIALPLAN_EXISTS() requires an argument\n");
return -1;
}
parse = ast_strdupa(data);
AST_STANDARD_APP_ARGS(args, parse);
if (!ast_strlen_zero(args.priority)) {
int priority_num;
if (sscanf(args.priority, "%30d", &priority_num) == 1 && priority_num > 0) {
int res;
res = ast_exists_extension(chan, args.context, args.exten, priority_num,
S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL));
if (res)
strcpy(buf, "1");
} else {
int res;
res = ast_findlabel_extension(chan, args.context, args.exten, args.priority,
S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL));
if (res > 0)
strcpy(buf, "1");
}
} else if (!ast_strlen_zero(args.exten)) {
int res;
res = ast_exists_extension(chan, args.context, args.exten, 1,
S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL));
if (res)
strcpy(buf, "1");
} else if (!ast_strlen_zero(args.context)) {
if (ast_context_find(args.context))
strcpy(buf, "1");
} else {
ast_log(LOG_ERROR, "Invalid arguments provided to DIALPLAN_EXISTS\n");
return -1;
}
return 0;
}
static int acf_isexten_exec(struct ast_channel *chan, const char *cmd, char *parse, char *buffer, size_t buflen)
{
int priority_int;
AST_DECLARE_APP_ARGS(args,
AST_APP_ARG(context);
AST_APP_ARG(extension);
AST_APP_ARG(priority);
);
AST_STANDARD_APP_ARGS(args, parse);
if (ast_strlen_zero(args.context)) {
args.context = ast_strdupa(ast_channel_context(chan));
}
if (ast_strlen_zero(args.extension)) {
ast_log(LOG_WARNING, "Syntax: VALID_EXTEN([<context>],<extension>[,<priority>]) - missing argument <extension>!\n");
return -1;
}
if (ast_strlen_zero(args.priority)) {
priority_int = 1;
} else {
priority_int = atoi(args.priority);
}
if (ast_exists_extension(chan, args.context, args.extension, priority_int,
S_COR(ast_channel_caller(chan)->id.number.valid, ast_channel_caller(chan)->id.number.str, NULL))) {
ast_copy_string(buffer, "1", buflen);
} else {
ast_copy_string(buffer, "0", buflen);
}
return 0;
}
static struct ast_custom_function isexten_function = {
.name = "DIALPLAN_EXISTS",
.read = isexten_function_read,
.read_max = 2,
};
static struct ast_custom_function acf_isexten = {
.name = "VALID_EXTEN",
.read = acf_isexten_exec,
};
static int unload_module(void)
{
int res = ast_custom_function_unregister(&isexten_function);
res |= ast_custom_function_unregister(&acf_isexten);
return res;
}
static int load_module(void)
{
int res = ast_custom_function_register(&isexten_function);
res |= ast_custom_function_register(&acf_isexten);
return res;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "Dialplan Context/Extension/Priority Checking Functions",
.load = load_module,
.unload = unload_module,
.load_pri = AST_MODPRI_APP_DEPEND,
);