1 /* $NetBSD: dns.c,v 1.1.1.2 2012/09/09 16:07:57 christos Exp $ */
2
3 /*
4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (c) 1996-1999 by Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 #if defined(LIBC_SCCS) && !defined(lint)
21 static const char rcsid[] = "Id: dns.c,v 1.5 2006/03/09 23:57:56 marka Exp ";
22 #endif
23
24 /*! \file
25 * \brief
26 * dns.c --- this is the top-level accessor function for the dns
27 */
28
29 #include "port_before.h"
30
31 #include <stdlib.h>
32 #include <string.h>
33 #include <errno.h>
34
35 #include <sys/types.h>
36 #include <netinet/in.h>
37 #include <arpa/nameser.h>
38 #include <resolv.h>
39
40 #include <resolv.h>
41
42 #include <isc/memcluster.h>
43 #include <irs.h>
44
45 #include "port_after.h"
46
47 #include "irs_p.h"
48 #include "hesiod.h"
49 #include "dns_p.h"
50
51 /* forward */
52
53 static void dns_close(struct irs_acc *);
54 static struct __res_state * dns_res_get(struct irs_acc *);
55 static void dns_res_set(struct irs_acc *, struct __res_state *,
56 void (*)(void *));
57
58 /* public */
59
60 struct irs_acc *
irs_dns_acc(const char * options)61 irs_dns_acc(const char *options) {
62 struct irs_acc *acc;
63 struct dns_p *dns;
64
65 UNUSED(options);
66
67 if (!(acc = memget(sizeof *acc))) {
68 errno = ENOMEM;
69 return (NULL);
70 }
71 memset(acc, 0x5e, sizeof *acc);
72 if (!(dns = memget(sizeof *dns))) {
73 errno = ENOMEM;
74 memput(acc, sizeof *acc);
75 return (NULL);
76 }
77 memset(dns, 0x5e, sizeof *dns);
78 dns->res = NULL;
79 dns->free_res = NULL;
80 if (hesiod_init(&dns->hes_ctx) < 0) {
81 /*
82 * We allow the dns accessor class to initialize
83 * despite hesiod failing to initialize correctly,
84 * since dns host queries don't depend on hesiod.
85 */
86 dns->hes_ctx = NULL;
87 }
88 acc->private = dns;
89 #ifdef WANT_IRS_GR
90 acc->gr_map = irs_dns_gr;
91 #else
92 acc->gr_map = NULL;
93 #endif
94 #ifdef WANT_IRS_PW
95 acc->pw_map = irs_dns_pw;
96 #else
97 acc->pw_map = NULL;
98 #endif
99 acc->sv_map = irs_dns_sv;
100 acc->pr_map = irs_dns_pr;
101 acc->ho_map = irs_dns_ho;
102 acc->nw_map = irs_dns_nw;
103 acc->ng_map = irs_nul_ng;
104 acc->res_get = dns_res_get;
105 acc->res_set = dns_res_set;
106 acc->close = dns_close;
107 return (acc);
108 }
109
110 /* methods */
111 static struct __res_state *
dns_res_get(struct irs_acc * this)112 dns_res_get(struct irs_acc *this) {
113 struct dns_p *dns = (struct dns_p *)this->private;
114
115 if (dns->res == NULL) {
116 struct __res_state *res;
117 res = (struct __res_state *)malloc(sizeof *res);
118 if (res == NULL)
119 return (NULL);
120 memset(res, 0, sizeof *res);
121 dns_res_set(this, res, free);
122 }
123
124 if ((dns->res->options & RES_INIT) == 0U &&
125 res_ninit(dns->res) < 0)
126 return (NULL);
127
128 return (dns->res);
129 }
130
131 static void
dns_res_set(struct irs_acc * this,struct __res_state * res,void (* free_res)(void *))132 dns_res_set(struct irs_acc *this, struct __res_state *res,
133 void (*free_res)(void *)) {
134 struct dns_p *dns = (struct dns_p *)this->private;
135
136 if (dns->res && dns->free_res) {
137 res_nclose(dns->res);
138 (*dns->free_res)(dns->res);
139 }
140 dns->res = res;
141 dns->free_res = free_res;
142 }
143
144 static void
dns_close(struct irs_acc * this)145 dns_close(struct irs_acc *this) {
146 struct dns_p *dns;
147
148 dns = (struct dns_p *)this->private;
149 if (dns->res && dns->free_res)
150 (*dns->free_res)(dns->res);
151 if (dns->hes_ctx)
152 hesiod_end(dns->hes_ctx);
153 memput(dns, sizeof *dns);
154 memput(this, sizeof *this);
155 }
156
157