aboutsummaryrefslogtreecommitdiffstats
path: root/funcs/func_config.c
blob: ecf281c9d980f8e10af89ec344b4e7d389bf550d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2008, Digium, Inc.
 *
 * Russell Bryant <russell@digium.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>
 * 
 * \ingroup functions
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/module.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/app.h"

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))) {
		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_malloc(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))) {
				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_malloc(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);
		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",
	.syntax = "AST_CONFIG(config_file,category,variable_name)",
	.synopsis = "Retrieve a variable from a configuration file",
	.desc = 
	"   This function reads a variable from an Asterisk configuration file.\n"
	"",
	.read = config_function_read,
};

static int unload_module(void)
{
	struct config_item *cur;
	int res = ast_custom_function_unregister(&config_function);

	/* Allow anything already in the routine to exit */
	usleep(1);
	AST_RWLIST_WRLOCK(&configs);
	usleep(1);
	AST_RWLIST_UNLOCK(&configs);
	/* Even if it needed to upgrade a lock */
	usleep(1);
	AST_RWLIST_WRLOCK(&configs);
	/* At this point, no other thread should be queued inside this module */
	while ((cur = AST_RWLIST_REMOVE_HEAD(&configs, entry))) {
		ast_config_destroy(cur->cfg);
		ast_free(cur);
	}
	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");