The AST_CONFIG dialplan function defined in func_config.c allocates its config file list entries using ast_malloc. List entry allocations destined for use with Asterisk's linked list API must be ast_calloc()d or otherwise initialized so that list pointers are set to NULL. These uses of ast_malloc have been replaced by ast_calloc to prevent dereferencing of uninitialized pointer values when traversing the list. (closes issue ASTERISK-22483) Reported by: Brian Scott ........ Merged revisions 400694 from http://svn.asterisk.org/svn/asterisk/branches/1.8 ........ Merged revisions 400697 from http://svn.asterisk.org/svn/asterisk/branches/11 ........ Merged revisions 400701 from http://svn.asterisk.org/svn/asterisk/branches/12 git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@400704 65c4cc65-6c06-0410-ace0-fbb531ad65f3
208 lines
5 KiB
C
208 lines
5 KiB
C
/*
|
|
* Asterisk -- An open source telephony toolkit.
|
|
*
|
|
* Copyright (C) 2008, Digium, Inc.
|
|
*
|
|
* Russell Bryant <russell@digium.com>
|
|
* Tilghman Lesher <func_config__200803@the-tilghman.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 A function to retrieve variables from an Asterisk configuration file
|
|
*
|
|
* \author Russell Bryant <russell@digium.com>
|
|
* \author Tilghman Lesher <func_config__200803@the-tilghman.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="AST_CONFIG" language="en_US">
|
|
<synopsis>
|
|
Retrieve a variable from a configuration file.
|
|
</synopsis>
|
|
<syntax>
|
|
<parameter name="config_file" required="true" />
|
|
<parameter name="category" required="true" />
|
|
<parameter name="variable_name" required="true" />
|
|
</syntax>
|
|
<description>
|
|
<para>This function reads a variable from an Asterisk configuration file.</para>
|
|
</description>
|
|
</function>
|
|
|
|
***/
|
|
|
|
struct config_item {
|
|
AST_RWLIST_ENTRY(config_item) entry;
|
|
struct ast_config *cfg;
|
|
char filename[0];
|
|
};
|
|
|
|
static AST_RWLIST_HEAD_STATIC(configs, config_item);
|
|
|
|
static int config_function_read(struct ast_channel *chan, const char *cmd, char *data,
|
|
char *buf, size_t len)
|
|
{
|
|
struct ast_config *cfg;
|
|
struct ast_flags cfg_flags = { CONFIG_FLAG_FILEUNCHANGED };
|
|
const char *val;
|
|
char *parse;
|
|
struct config_item *cur;
|
|
AST_DECLARE_APP_ARGS(args,
|
|
AST_APP_ARG(filename);
|
|
AST_APP_ARG(category);
|
|
AST_APP_ARG(variable);
|
|
AST_APP_ARG(index);
|
|
);
|
|
|
|
if (ast_strlen_zero(data)) {
|
|
ast_log(LOG_ERROR, "AST_CONFIG() requires an argument\n");
|
|
return -1;
|
|
}
|
|
|
|
parse = ast_strdupa(data);
|
|
AST_STANDARD_APP_ARGS(args, parse);
|
|
|
|
if (ast_strlen_zero(args.filename)) {
|
|
ast_log(LOG_ERROR, "AST_CONFIG() requires a filename\n");
|
|
return -1;
|
|
}
|
|
|
|
if (ast_strlen_zero(args.category)) {
|
|
ast_log(LOG_ERROR, "AST_CONFIG() requires a category\n");
|
|
return -1;
|
|
}
|
|
|
|
if (ast_strlen_zero(args.variable)) {
|
|
ast_log(LOG_ERROR, "AST_CONFIG() requires a variable\n");
|
|
return -1;
|
|
}
|
|
|
|
if (!(cfg = ast_config_load(args.filename, cfg_flags)) || cfg == CONFIG_STATUS_FILEINVALID) {
|
|
return -1;
|
|
}
|
|
|
|
if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
|
|
/* Retrieve cfg from list */
|
|
AST_RWLIST_RDLOCK(&configs);
|
|
AST_RWLIST_TRAVERSE(&configs, cur, entry) {
|
|
if (!strcmp(cur->filename, args.filename)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!cur) {
|
|
/* At worst, we might leak an entry while upgrading locks */
|
|
AST_RWLIST_UNLOCK(&configs);
|
|
AST_RWLIST_WRLOCK(&configs);
|
|
if (!(cur = ast_calloc(1, sizeof(*cur) + strlen(args.filename) + 1))) {
|
|
AST_RWLIST_UNLOCK(&configs);
|
|
return -1;
|
|
}
|
|
|
|
strcpy(cur->filename, args.filename);
|
|
|
|
ast_clear_flag(&cfg_flags, CONFIG_FLAG_FILEUNCHANGED);
|
|
if (!(cfg = ast_config_load(args.filename, cfg_flags)) || cfg == CONFIG_STATUS_FILEINVALID) {
|
|
ast_free(cur);
|
|
AST_RWLIST_UNLOCK(&configs);
|
|
return -1;
|
|
}
|
|
|
|
cur->cfg = cfg;
|
|
AST_RWLIST_INSERT_TAIL(&configs, cur, entry);
|
|
}
|
|
|
|
cfg = cur->cfg;
|
|
} else {
|
|
/* Replace cfg in list */
|
|
AST_RWLIST_WRLOCK(&configs);
|
|
AST_RWLIST_TRAVERSE(&configs, cur, entry) {
|
|
if (!strcmp(cur->filename, args.filename)) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!cur) {
|
|
if (!(cur = ast_calloc(1, sizeof(*cur) + strlen(args.filename) + 1))) {
|
|
AST_RWLIST_UNLOCK(&configs);
|
|
return -1;
|
|
}
|
|
|
|
strcpy(cur->filename, args.filename);
|
|
cur->cfg = cfg;
|
|
|
|
AST_RWLIST_INSERT_TAIL(&configs, cur, entry);
|
|
} else {
|
|
ast_config_destroy(cur->cfg);
|
|
cur->cfg = cfg;
|
|
}
|
|
}
|
|
|
|
if (!(val = ast_variable_retrieve(cfg, args.category, args.variable))) {
|
|
ast_log(LOG_ERROR, "'%s' not found in [%s] of '%s'\n", args.variable,
|
|
args.category, args.filename);
|
|
AST_RWLIST_UNLOCK(&configs);
|
|
return -1;
|
|
}
|
|
|
|
ast_copy_string(buf, val, len);
|
|
|
|
/* Unlock down here, so there's no chance the struct goes away while we're using it. */
|
|
AST_RWLIST_UNLOCK(&configs);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct ast_custom_function config_function = {
|
|
.name = "AST_CONFIG",
|
|
.read = config_function_read,
|
|
};
|
|
|
|
static int unload_module(void)
|
|
{
|
|
struct config_item *current;
|
|
int res = ast_custom_function_unregister(&config_function);
|
|
|
|
AST_RWLIST_WRLOCK(&configs);
|
|
while ((current = AST_RWLIST_REMOVE_HEAD(&configs, entry))) {
|
|
ast_config_destroy(current->cfg);
|
|
ast_free(current);
|
|
}
|
|
AST_RWLIST_UNLOCK(&configs);
|
|
|
|
return res;
|
|
}
|
|
|
|
static int load_module(void)
|
|
{
|
|
return ast_custom_function_register(&config_function);
|
|
}
|
|
|
|
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Asterisk configuration file variable access");
|