dns.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
1/*
2 * Copyright 1997-2002 Sun Microsystems, Inc.  All rights reserved.
3 * Use is subject to license terms.
4 */
5
6/*
7 * Copyright (c) 1996-1999 by Internet Software Consortium.
8 *
9 * Permission to use, copy, modify, and distribute this software for any
10 * purpose with or without fee is hereby granted, provided that the above
11 * copyright notice and this permission notice appear in all copies.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
14 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
15 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
16 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
17 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
18 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
19 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
20 * SOFTWARE.
21 */
22
23#pragma ident	"%Z%%M%	%I%	%E% SMI"
24
25#if defined(LIBC_SCCS) && !defined(lint)
26static const char rcsid[] = "$Id: dns.c,v 1.16 2001/05/29 05:48:26 marka Exp $";
27#endif
28
29/*
30 * dns.c --- this is the top-level accessor function for the dns
31 */
32
33#include "port_before.h"
34
35#include <stdlib.h>
36#include <string.h>
37#include <errno.h>
38
39#include <sys/types.h>
40#include <netinet/in.h>
41#include <arpa/nameser.h>
42#include <resolv.h>
43
44#include <resolv.h>
45
46#include <isc/memcluster.h>
47#include <irs.h>
48
49#include "port_after.h"
50
51#include "irs_p.h"
52#include "hesiod.h"
53#include "dns_p.h"
54
55/* forward */
56
57static void		dns_close(struct irs_acc *);
58static struct __res_state *	dns_res_get(struct irs_acc *);
59static void		dns_res_set(struct irs_acc *, struct __res_state *,
60				void (*)(void *));
61
62/* public */
63
64struct irs_acc *
65irs_dns_acc(const char *options) {
66	struct irs_acc *acc;
67	struct dns_p *dns;
68
69	UNUSED(options);
70
71	if (!(acc = memget(sizeof *acc))) {
72		errno = ENOMEM;
73		return (NULL);
74	}
75	memset(acc, 0x5e, sizeof *acc);
76	if (!(dns = memget(sizeof *dns))) {
77		errno = ENOMEM;
78		memput(acc, sizeof *acc);
79		return (NULL);
80	}
81	memset(dns, 0x5e, sizeof *dns);
82	dns->res = NULL;
83	dns->free_res = NULL;
84	if (hesiod_init(&dns->hes_ctx) < 0) {
85		/*
86		 * We allow the dns accessor class to initialize
87		 * despite hesiod failing to initialize correctly,
88		 * since dns host queries don't depend on hesiod.
89		 */
90		dns->hes_ctx = NULL;
91	}
92	acc->private = dns;
93#ifdef WANT_IRS_GR
94	acc->gr_map = irs_dns_gr;
95#else
96	acc->gr_map = NULL;
97#endif
98#ifdef WANT_IRS_PW
99	acc->pw_map = irs_dns_pw;
100#else
101	acc->pw_map = NULL;
102#endif
103	acc->sv_map = irs_dns_sv;
104	acc->pr_map = irs_dns_pr;
105	acc->ho_map = irs_dns_ho;
106	acc->nw_map = irs_dns_nw;
107	acc->ng_map = irs_nul_ng;
108	acc->res_get = dns_res_get;
109	acc->res_set = dns_res_set;
110	acc->close = dns_close;
111	return (acc);
112}
113
114/* methods */
115static struct __res_state *
116dns_res_get(struct irs_acc *this) {
117	struct dns_p *dns = (struct dns_p *)this->private;
118
119	if (dns->res == NULL) {
120		struct __res_state *res;
121		res = (struct __res_state *)malloc(sizeof *res);
122		if (res == NULL)
123			return (NULL);
124		memset(dns->res, 0, sizeof *dns->res);
125		dns_res_set(this, res, free);
126	}
127
128	if ((dns->res->options & RES_INIT) == 0 &&
129	    res_ninit(dns->res) < 0)
130		return (NULL);
131
132	return (dns->res);
133}
134
135static void
136dns_res_set(struct irs_acc *this, struct __res_state *res,
137	    void (*free_res)(void *)) {
138	struct dns_p *dns = (struct dns_p *)this->private;
139
140	if (dns->res && dns->free_res) {
141		res_nclose(dns->res);
142		(*dns->free_res)(dns->res);
143	}
144	dns->res = res;
145	dns->free_res = free_res;
146}
147
148static void
149dns_close(struct irs_acc *this) {
150	struct dns_p *dns;
151
152	dns = (struct dns_p *)this->private;
153	if (dns->res && dns->free_res)
154		(*dns->free_res)(dns->res);
155	if (dns->hes_ctx)
156		hesiod_end(dns->hes_ctx);
157	memput(dns, sizeof *dns);
158	memput(this, sizeof *this);
159}
160
161