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 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char rcsid[] = "$Id: dns.c,v 1.5 2006/03/09 23:57:56 marka Exp $";
20 #endif
21
22 /*! \file
23 * \brief
24 * dns.c --- this is the top-level accessor function for the dns
25 */
26
27 #include "port_before.h"
28
29 #include <stdlib.h>
30 #include <string.h>
31 #include <errno.h>
32
33 #include <sys/types.h>
34 #include <netinet/in.h>
35 #include <arpa/nameser.h>
36 #include <resolv.h>
37
38 #include <resolv.h>
39
40 #include <isc/memcluster.h>
41 #include <irs.h>
42
43 #include "port_after.h"
44
45 #include "irs_p.h"
46 #include "hesiod.h"
47 #include "dns_p.h"
48
49 /* forward */
50
51 static void dns_close(struct irs_acc *);
52 static struct __res_state * dns_res_get(struct irs_acc *);
53 static void dns_res_set(struct irs_acc *, struct __res_state *,
54 void (*)(void *));
55
56 /* public */
57
58 struct irs_acc *
irs_dns_acc(const char * options)59 irs_dns_acc(const char *options) {
60 struct irs_acc *acc;
61 struct dns_p *dns;
62
63 UNUSED(options);
64
65 if (!(acc = memget(sizeof *acc))) {
66 errno = ENOMEM;
67 return (NULL);
68 }
69 memset(acc, 0x5e, sizeof *acc);
70 if (!(dns = memget(sizeof *dns))) {
71 errno = ENOMEM;
72 memput(acc, sizeof *acc);
73 return (NULL);
74 }
75 memset(dns, 0x5e, sizeof *dns);
76 dns->res = NULL;
77 dns->free_res = NULL;
78 if (hesiod_init(&dns->hes_ctx) < 0) {
79 /*
80 * We allow the dns accessor class to initialize
81 * despite hesiod failing to initialize correctly,
82 * since dns host queries don't depend on hesiod.
83 */
84 dns->hes_ctx = NULL;
85 }
86 acc->private = dns;
87 #ifdef WANT_IRS_GR
88 acc->gr_map = irs_dns_gr;
89 #else
90 acc->gr_map = NULL;
91 #endif
92 #ifdef WANT_IRS_PW
93 acc->pw_map = irs_dns_pw;
94 #else
95 acc->pw_map = NULL;
96 #endif
97 acc->sv_map = irs_dns_sv;
98 acc->pr_map = irs_dns_pr;
99 acc->ho_map = irs_dns_ho;
100 acc->nw_map = irs_dns_nw;
101 acc->ng_map = irs_nul_ng;
102 acc->res_get = dns_res_get;
103 acc->res_set = dns_res_set;
104 acc->close = dns_close;
105 return (acc);
106 }
107
108 /* methods */
109 static struct __res_state *
dns_res_get(struct irs_acc * this)110 dns_res_get(struct irs_acc *this) {
111 struct dns_p *dns = (struct dns_p *)this->private;
112
113 if (dns->res == NULL) {
114 struct __res_state *res;
115 res = (struct __res_state *)malloc(sizeof *res);
116 if (res == NULL)
117 return (NULL);
118 memset(res, 0, sizeof *res);
119 dns_res_set(this, res, free);
120 }
121
122 if ((dns->res->options & RES_INIT) == 0U &&
123 res_ninit(dns->res) < 0)
124 return (NULL);
125
126 return (dns->res);
127 }
128
129 static void
dns_res_set(struct irs_acc * this,struct __res_state * res,void (* free_res)(void *))130 dns_res_set(struct irs_acc *this, struct __res_state *res,
131 void (*free_res)(void *)) {
132 struct dns_p *dns = (struct dns_p *)this->private;
133
134 if (dns->res && dns->free_res) {
135 res_nclose(dns->res);
136 (*dns->free_res)(dns->res);
137 }
138 dns->res = res;
139 dns->free_res = free_res;
140 }
141
142 static void
dns_close(struct irs_acc * this)143 dns_close(struct irs_acc *this) {
144 struct dns_p *dns;
145
146 dns = (struct dns_p *)this->private;
147 if (dns->res && dns->free_res)
148 (*dns->free_res)(dns->res);
149 if (dns->hes_ctx)
150 hesiod_end(dns->hes_ctx);
151 memput(dns, sizeof *dns);
152 memput(this, sizeof *this);
153 }
154
155