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 47 static void dns_close(struct irs_acc *); 48 static struct __res_state * dns_res_get(struct irs_acc *); 49 static void dns_res_set(struct irs_acc *, struct __res_state *, 50 void (*)(void *)); 51 52 /* public */ 53 54 struct irs_acc * 55 irs_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 */ 105 static struct __res_state * 106 dns_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 } 124 125 static void 126 dns_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 } 137 138 static void 139 dns_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