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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (c) 2004-2006 Tilghman Lesher <app_stack_v003@the-tilghman.com>.
*
* This code is released by the author with no restrictions on usage.
*
* 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 Stack applications Gosub, Return, etc.
*
* \author Tilghman Lesher <app_stack_v003@the-tilghman.com>
*
* \ingroup applications
*/
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "asterisk/options.h"
#include "asterisk/logger.h"
#include "asterisk/channel.h"
#include "asterisk/chanvars.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/app.h"
#define STACKVAR "~GOSUB~STACK~"
static const char *app_gosub = "Gosub";
static const char *app_gosubif = "GosubIf";
static const char *app_return = "Return";
static const char *app_pop = "StackPop";
static const char *gosub_synopsis = "Jump to label, saving return address";
static const char *gosubif_synopsis = "Conditionally jump to label, saving return address";
static const char *return_synopsis = "Return from gosub routine";
static const char *pop_synopsis = "Remove one address from gosub stack";
static const char *gosub_descrip =
"Gosub([[context|]exten|]priority[(arg1[|...][|argN])])\n"
" Jumps to the label specified, saving the return address.\n";
static const char *gosubif_descrip =
"GosubIf(condition?labeliftrue[(arg1[|...])][:labeliffalse[(arg1[|...])]])\n"
" If the condition is true, then jump to labeliftrue. If false, jumps to\n"
"labeliffalse, if specified. In either case, a jump saves the return point\n"
"in the dialplan, to be returned to with a Return.\n";
static const char *return_descrip =
"Return([return-value])\n"
" Jumps to the last label on the stack, removing it. The return value, if\n"
"any, is saved in the channel variable GOSUB_RETVAL.\n";
static const char *pop_descrip =
"StackPop()\n"
" Removes last label on the stack, discarding it.\n";
static int pop_exec(struct ast_channel *chan, void *data)
{
const char *frame = pbx_builtin_getvar_helper(chan, STACKVAR);
int numargs = 0, i;
char argname[15];
/* Pop any arguments for this stack frame off the variable stack */
if (frame) {
numargs = atoi(frame);
for (i = 1; i <= numargs; i++) {
snprintf(argname, sizeof(argname), "ARG%d", i);
pbx_builtin_setvar_helper(chan, argname, NULL);
}
}
/* Remove the last frame from the Gosub stack */
pbx_builtin_setvar_helper(chan, STACKVAR, NULL);
return 0;
}
static int return_exec(struct ast_channel *chan, void *data)
{
const char *label = pbx_builtin_getvar_helper(chan, STACKVAR);
char argname[15], *retval = data;
int numargs, i;
if (ast_strlen_zero(label)) {
ast_log(LOG_ERROR, "Return without Gosub: stack is empty\n");
return -1;
}
/* Pop any arguments for this stack frame off the variable stack */
numargs = atoi(label);
for (i = 1; i <= numargs; i++) {
snprintf(argname, sizeof(argname), "ARG%d", i);
pbx_builtin_setvar_helper(chan, argname, NULL);
}
/* If the label exists, it will always have a ':' */
label = strchr(label, ':') + 1;
if (ast_parseable_goto(chan, label)) {
ast_log(LOG_WARNING, "No next statement after Gosub?\n");
return -1;
}
/* Remove the current frame from the Gosub stack */
pbx_builtin_setvar_helper(chan, STACKVAR, NULL);
/* Set a return value, if any */
pbx_builtin_setvar_helper(chan, "GOSUB_RETVAL", S_OR(retval, ""));
return 0;
}
static int gosub_exec(struct ast_channel *chan, void *data)
{
char newlabel[AST_MAX_EXTENSION + AST_MAX_CONTEXT + 11 + 11 + 4];
char argname[15], *tmp = ast_strdupa(data), *label, *endparen;
int i;
struct ast_module_user *u;
AST_DECLARE_APP_ARGS(args2,
AST_APP_ARG(argval)[100];
);
if (ast_strlen_zero(data)) {
ast_log(LOG_ERROR, "%s requires an argument: %s([[context|]exten|]priority[(arg1[|...][|argN])])\n", app_gosub, app_gosub);
return -1;
}
u = ast_module_user_add(chan);
/* Separate the arguments from the label */
/* NOTE: you cannot use ast_app_separate_args for this, because '(' cannot be used as a delimiter. */
label = strsep(&tmp, "(");
if (tmp) {
endparen = strrchr(tmp, ')');
if (endparen)
*endparen = '\0';
else
ast_log(LOG_WARNING, "Ouch. No closing paren: '%s'?\n", (char *)data);
AST_STANDARD_APP_ARGS(args2, tmp);
} else
args2.argc = 0;
/* Create the return address, but don't save it until we know that the Gosub destination exists */
snprintf(newlabel, sizeof(newlabel), "%d:%s|%s|%d", args2.argc, chan->context, chan->exten, chan->priority + 1);
if (ast_parseable_goto(chan, label)) {
ast_log(LOG_ERROR, "Gosub address is invalid: '%s'\n", (char *)data);
ast_module_user_remove(u);
return -1;
}
/* Now that we know for certain that we're going to a new location, set our arguments */
for (i = 0; i < args2.argc; i++) {
snprintf(argname, sizeof(argname), "ARG%d", i + 1);
pbx_builtin_pushvar_helper(chan, argname, args2.argval[i]);
ast_log(LOG_DEBUG, "Setting '%s' to '%s'\n", argname, args2.argval[i]);
}
/* And finally, save our return address */
pbx_builtin_pushvar_helper(chan, STACKVAR, newlabel);
ast_log(LOG_DEBUG, "Setting gosub return address to '%s'\n", newlabel);
ast_module_user_remove(u);
return 0;
}
static int gosubif_exec(struct ast_channel *chan, void *data)
{
struct ast_module_user *u;
char *args;
int res=0;
AST_DECLARE_APP_ARGS(cond,
AST_APP_ARG(ition);
AST_APP_ARG(labels);
);
AST_DECLARE_APP_ARGS(label,
AST_APP_ARG(iftrue);
AST_APP_ARG(iffalse);
);
if (ast_strlen_zero(data)) {
ast_log(LOG_WARNING, "GosubIf requires an argument: GosubIf(cond?label1(args):label2(args)\n");
return 0;
}
u = ast_module_user_add(chan);
args = ast_strdupa(data);
AST_NONSTANDARD_APP_ARGS(cond, args, '?');
if (cond.argc != 2) {
ast_log(LOG_WARNING, "GosubIf requires an argument: GosubIf(cond?label1(args):label2(args)\n");
ast_module_user_remove(u);
return 0;
}
AST_NONSTANDARD_APP_ARGS(label, cond.labels, ':');
if (pbx_checkcondition(cond.ition)) {
if (!ast_strlen_zero(label.iftrue))
res = gosub_exec(chan, label.iftrue);
} else if (!ast_strlen_zero(label.iffalse)) {
res = gosub_exec(chan, label.iffalse);
}
ast_module_user_remove(u);
return res;
}
static int unload_module(void)
{
ast_unregister_application(app_return);
ast_unregister_application(app_pop);
ast_unregister_application(app_gosubif);
ast_unregister_application(app_gosub);
ast_module_user_hangup_all();
return 0;
}
static int load_module(void)
{
ast_register_application(app_pop, pop_exec, pop_synopsis, pop_descrip);
ast_register_application(app_return, return_exec, return_synopsis, return_descrip);
ast_register_application(app_gosubif, gosubif_exec, gosubif_synopsis, gosubif_descrip);
ast_register_application(app_gosub, gosub_exec, gosub_synopsis, gosub_descrip);
return 0;
}
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Stack Routines");
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