1/*-
2 * Copyright (c) 2006 The FreeBSD Project. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * $FreeBSD$
26 */
27
28#include <sys/types.h>
29#include <netinet/in.h>
30#include <arpa/nameser.h>
31#include <resolv.h>
32#include <stdlib.h>
33
34#include "namespace.h"
35#include "reentrant.h"
36#include "un-namespace.h"
37
38#undef _res
39
40struct __res_state _res;
41
42static thread_key_t res_key;
43static once_t res_init_once = ONCE_INITIALIZER;
44static int res_thr_keycreated = 0;
45
46static void
47free_res(void *ptr)
48{
49	res_state statp = ptr;
50
51	if (statp->_u._ext.ext != NULL)
52		res_ndestroy(statp);
53	free(statp);
54}
55
56static void
57res_keycreate(void)
58{
59	res_thr_keycreated = thr_keycreate(&res_key, free_res) == 0;
60}
61
62res_state
63__res_state(void)
64{
65	res_state statp;
66
67	if (thr_main() != 0)
68		return (&_res);
69
70	if (thr_once(&res_init_once, res_keycreate) != 0 ||
71	    !res_thr_keycreated)
72		return (&_res);
73
74	statp = thr_getspecific(res_key);
75	if (statp != NULL)
76		return (statp);
77	statp = calloc(1, sizeof(*statp));
78	if (statp == NULL)
79		return (&_res);
80#ifdef __BIND_RES_TEXT
81	statp->options = RES_TIMEOUT;			/* Motorola, et al. */
82#endif
83	if (thr_setspecific(res_key, statp) == 0)
84		return (statp);
85	free(statp);
86	return (&_res);
87}
88