1/*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996-1999 by Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/*! \file
19 * \brief
20 * dns.c --- this is the top-level accessor function for the dns
21 */
22
23#include "port_before.h"
24
25#include <stdlib.h>
26#include <string.h>
27#include <errno.h>
28
29#include <sys/types.h>
30#include <netinet/in.h>
31#include <arpa/nameser.h>
32#include <resolv.h>
33
34#include <resolv.h>
35
36#include <isc/memcluster.h>
37#include <irs.h>
38
39#include "port_after.h"
40
41#include "irs_p.h"
42#include "hesiod.h"
43#include "dns_p.h"
44
45/* forward */
46
47static void		dns_close(struct irs_acc *);
48static struct __res_state *	dns_res_get(struct irs_acc *);
49static void		dns_res_set(struct irs_acc *, struct __res_state *,
50				void (*)(void *));
51
52/* public */
53
54struct irs_acc *
55irs_dns_acc(const char *options) {
56	struct irs_acc *acc;
57	struct dns_p *dns;
58
59	UNUSED(options);
60
61	if (!(acc = memget(sizeof *acc))) {
62		errno = ENOMEM;
63		return (NULL);
64	}
65	memset(acc, 0x5e, sizeof *acc);
66	if (!(dns = memget(sizeof *dns))) {
67		errno = ENOMEM;
68		memput(acc, sizeof *acc);
69		return (NULL);
70	}
71	memset(dns, 0x5e, sizeof *dns);
72	dns->res = NULL;
73	dns->free_res = NULL;
74	if (hesiod_init(&dns->hes_ctx) < 0) {
75		/*
76		 * We allow the dns accessor class to initialize
77		 * despite hesiod failing to initialize correctly,
78		 * since dns host queries don't depend on hesiod.
79		 */
80		dns->hes_ctx = NULL;
81	}
82	acc->private = dns;
83#ifdef WANT_IRS_GR
84	acc->gr_map = irs_dns_gr;
85#else
86	acc->gr_map = NULL;
87#endif
88#ifdef WANT_IRS_PW
89	acc->pw_map = irs_dns_pw;
90#else
91	acc->pw_map = NULL;
92#endif
93	acc->sv_map = irs_dns_sv;
94	acc->pr_map = irs_dns_pr;
95	acc->ho_map = irs_dns_ho;
96	acc->nw_map = irs_dns_nw;
97	acc->ng_map = irs_nul_ng;
98	acc->res_get = dns_res_get;
99	acc->res_set = dns_res_set;
100	acc->close = dns_close;
101	return (acc);
102}
103
104/* methods */
105static struct __res_state *
106dns_res_get(struct irs_acc *this) {
107	struct dns_p *dns = (struct dns_p *)this->private;
108
109	if (dns->res == NULL) {
110		struct __res_state *res;
111		res = (struct __res_state *)malloc(sizeof *res);
112		if (res == NULL)
113			return (NULL);
114		memset(res, 0, sizeof *res);
115		dns_res_set(this, res, free);
116	}
117
118	if ((dns->res->options & RES_INIT) == 0U &&
119	    res_ninit(dns->res) < 0)
120		return (NULL);
121
122	return (dns->res);
123}
124
125static void
126dns_res_set(struct irs_acc *this, struct __res_state *res,
127	    void (*free_res)(void *)) {
128	struct dns_p *dns = (struct dns_p *)this->private;
129
130	if (dns->res && dns->free_res) {
131		res_nclose(dns->res);
132		(*dns->free_res)(dns->res);
133	}
134	dns->res = res;
135	dns->free_res = free_res;
136}
137
138static void
139dns_close(struct irs_acc *this) {
140	struct dns_p *dns;
141
142	dns = (struct dns_p *)this->private;
143	if (dns->res && dns->free_res)
144		(*dns->free_res)(dns->res);
145	if (dns->hes_ctx)
146		hesiod_end(dns->hes_ctx);
147	memput(dns, sizeof *dns);
148	memput(this, sizeof *this);
149}
150
151