external/bsd/libbind/dist/irs/dns.c

   1 /*      $NetBSD$        */
   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 *
  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 *
 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
 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
 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