Asterisk - The Open Source Telephony Project GIT-master-f36a736
func_config.c
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1/*
2 * Asterisk -- An open source telephony toolkit.
3 *
4 * Copyright (C) 2008, Digium, Inc.
5 *
6 * Russell Bryant <russell@digium.com>
7 * Tilghman Lesher <func_config__200803@the-tilghman.com>
8 *
9 * See http://www.asterisk.org for more information about
10 * the Asterisk project. Please do not directly contact
11 * any of the maintainers of this project for assistance;
12 * the project provides a web site, mailing lists and IRC
13 * channels for your use.
14 *
15 * This program is free software, distributed under the terms of
16 * the GNU General Public License Version 2. See the LICENSE file
17 * at the top of the source tree.
18 */
19
20/*! \file
21 *
22 * \brief A function to retrieve variables from an Asterisk configuration file
23 *
24 * \author Russell Bryant <russell@digium.com>
25 * \author Tilghman Lesher <func_config__200803@the-tilghman.com>
26 *
27 * \ingroup functions
28 */
29
30/*** MODULEINFO
31 <support_level>core</support_level>
32 ***/
33
34#include "asterisk.h"
35
36#include "asterisk/module.h"
37#include "asterisk/channel.h"
38#include "asterisk/pbx.h"
39#include "asterisk/app.h"
40
41/*** DOCUMENTATION
42 <function name="AST_CONFIG" language="en_US">
43 <synopsis>
44 Retrieve a variable from a configuration file.
45 </synopsis>
46 <syntax>
47 <parameter name="config_file" required="true" />
48 <parameter name="category" required="true" />
49 <parameter name="variable_name" required="true" />
50 <parameter name="index" required="false">
51 <para>If there are multiple variables with the same name, you can specify
52 <literal>0</literal> for the first item (default), <literal>-1</literal> for the last
53 item, or any other number for that specific item. <literal>-1</literal> is useful
54 when the variable is derived from a template and you want the effective value (the last
55 occurrence), not the value from the template (the first occurrence).</para>
56 </parameter>
57 </syntax>
58 <description>
59 <para>This function reads a variable from an Asterisk configuration file.</para>
60 </description>
61 </function>
62
63***/
64
67 struct ast_config *cfg;
68 char filename[0];
69};
70
72
73static int config_function_read(struct ast_channel *chan, const char *cmd, char *data,
74 char *buf, size_t len)
75{
76 struct ast_config *cfg;
77 struct ast_flags cfg_flags = { CONFIG_FLAG_FILEUNCHANGED };
78 char *parse;
79 struct config_item *cur;
80 int index = 0;
81 struct ast_variable *var;
82 struct ast_variable *found = NULL;
83 int ix = 0;
85 AST_APP_ARG(filename);
86 AST_APP_ARG(category);
87 AST_APP_ARG(variable);
88 AST_APP_ARG(index);
89 );
90
91 if (ast_strlen_zero(data)) {
92 ast_log(LOG_ERROR, "AST_CONFIG() requires an argument\n");
93 return -1;
94 }
95
96 parse = ast_strdupa(data);
98
99 if (ast_strlen_zero(args.filename)) {
100 ast_log(LOG_ERROR, "AST_CONFIG() requires a filename\n");
101 return -1;
102 }
103
104 if (ast_strlen_zero(args.category)) {
105 ast_log(LOG_ERROR, "AST_CONFIG() requires a category\n");
106 return -1;
107 }
108
109 if (ast_strlen_zero(args.variable)) {
110 ast_log(LOG_ERROR, "AST_CONFIG() requires a variable\n");
111 return -1;
112 }
113
114 if (!ast_strlen_zero(args.index)) {
115 if (!sscanf(args.index, "%d", &index)) {
116 ast_log(LOG_ERROR, "AST_CONFIG() index must be an integer\n");
117 return -1;
118 }
119 }
120
121 if (!(cfg = ast_config_load(args.filename, cfg_flags)) || cfg == CONFIG_STATUS_FILEINVALID) {
122 return -1;
123 }
124
125 if (cfg == CONFIG_STATUS_FILEUNCHANGED) {
126 /* Retrieve cfg from list */
129 if (!strcmp(cur->filename, args.filename)) {
130 break;
131 }
132 }
133
134 if (!cur) {
135 /* At worst, we might leak an entry while upgrading locks */
138 if (!(cur = ast_calloc(1, sizeof(*cur) + strlen(args.filename) + 1))) {
140 return -1;
141 }
142
143 strcpy(cur->filename, args.filename);
144
146 if (!(cfg = ast_config_load(args.filename, cfg_flags)) || cfg == CONFIG_STATUS_FILEINVALID) {
147 ast_free(cur);
149 return -1;
150 }
151
152 cur->cfg = cfg;
154 }
155
156 cfg = cur->cfg;
157 } else {
158 /* Replace cfg in list */
161 if (!strcmp(cur->filename, args.filename)) {
162 break;
163 }
164 }
165
166 if (!cur) {
167 if (!(cur = ast_calloc(1, sizeof(*cur) + strlen(args.filename) + 1))) {
169 return -1;
170 }
171
172 strcpy(cur->filename, args.filename);
173 cur->cfg = cfg;
174
176 } else {
177 ast_config_destroy(cur->cfg);
178 cur->cfg = cfg;
179 }
180 }
181
182 for (var = ast_category_root(cfg, args.category); var; var = var->next) {
183 if (strcasecmp(args.variable, var->name)) {
184 continue;
185 }
186 found = var;
187 if (index == -1) {
188 continue;
189 }
190 if (ix == index) {
191 break;
192 }
193 found = NULL;
194 ix++;
195 }
196
197 if (!found) {
198 ast_debug(1, "'%s' not found at index %d in [%s] of '%s'. Maximum index found: %d\n",
199 args.variable, index, args.category, args.filename, ix);
201 return -1;
202 }
203
204 ast_copy_string(buf, found->value, len);
205
206 /* Unlock down here, so there's no chance the struct goes away while we're using it. */
208
209 return 0;
210}
211
213 .name = "AST_CONFIG",
214 .read = config_function_read,
215};
216
217static int unload_module(void)
218{
219 struct config_item *current;
221
226 }
228
229 return res;
230}
231
232static int load_module(void)
233{
235}
236
237AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Asterisk configuration file variable access");
#define var
Definition: ast_expr2f.c:605
Asterisk main include file. File version handling, generic pbx functions.
#define ast_free(a)
Definition: astmm.h:180
#define ast_strdupa(s)
duplicate a string in memory from the stack
Definition: astmm.h:298
#define ast_calloc(num, len)
A wrapper for calloc()
Definition: astmm.h:202
#define ast_log
Definition: astobj2.c:42
General Asterisk PBX channel definitions.
char buf[BUFSIZE]
Definition: eagi_proxy.c:66
static int config_function_read(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
Definition: func_config.c:73
static struct ast_custom_function config_function
Definition: func_config.c:212
static int load_module(void)
Definition: func_config.c:232
static int unload_module(void)
Definition: func_config.c:217
static int len(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t buflen)
Application convenience functions, designed to give consistent look and feel to Asterisk apps.
#define AST_APP_ARG(name)
Define an application argument.
#define AST_DECLARE_APP_ARGS(name, arglist)
Declare a structure to hold an application's arguments.
#define AST_STANDARD_APP_ARGS(args, parse)
Performs the 'standard' argument separation process for an application.
#define ast_config_load(filename, flags)
Load a config file.
#define CONFIG_STATUS_FILEUNCHANGED
#define CONFIG_STATUS_FILEINVALID
struct ast_variable * ast_category_root(struct ast_config *config, char *cat)
returns the root ast_variable of a config
Definition: main/config.c:1260
void ast_config_destroy(struct ast_config *cfg)
Destroys a config.
Definition: extconf.c:1289
@ CONFIG_FLAG_FILEUNCHANGED
#define ast_debug(level,...)
Log a DEBUG message.
#define LOG_ERROR
#define AST_RWLIST_RDLOCK(head)
Read locks a list.
Definition: linkedlists.h:78
#define AST_RWLIST_WRLOCK(head)
Write locks a list.
Definition: linkedlists.h:52
#define AST_RWLIST_UNLOCK(head)
Attempts to unlock a read/write based list.
Definition: linkedlists.h:151
#define AST_RWLIST_HEAD_STATIC(name, type)
Defines a structure to be used to hold a read/write list of specified type, statically initialized.
Definition: linkedlists.h:333
#define AST_RWLIST_REMOVE_HEAD
Definition: linkedlists.h:844
#define AST_RWLIST_TRAVERSE
Definition: linkedlists.h:494
#define AST_RWLIST_INSERT_TAIL
Definition: linkedlists.h:741
#define AST_RWLIST_ENTRY
Definition: linkedlists.h:415
size_t current
Definition: main/cli.c:113
Asterisk module definitions.
#define AST_MODULE_INFO_STANDARD(keystr, desc)
Definition: module.h:581
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:46
Core PBX routines and definitions.
#define ast_custom_function_register(acf)
Register a custom function.
Definition: pbx.h:1558
int ast_custom_function_unregister(struct ast_custom_function *acf)
Unregister a custom function.
#define NULL
Definition: resample.c:96
static force_inline int attribute_pure ast_strlen_zero(const char *s)
Definition: strings.h:65
void ast_copy_string(char *dst, const char *src, size_t size)
Size-limited null-terminating string copy.
Definition: strings.h:425
Main Channel structure associated with a channel.
Data structure associated with a custom dialplan function.
Definition: pbx.h:118
const char * name
Definition: pbx.h:119
Structure used to handle boolean flags.
Definition: utils.h:199
Structure for variables, used for configurations and for channel variables.
Definition: search.h:40
const char * args
#define ast_clear_flag(p, flag)
Definition: utils.h:77