external/bsd/bind/dist/lib/dns/soa.c

   1 /*      $NetBSD: soa.c,v 1.4 2014/12/10 04:37:58 christos Exp $ */
   2
   3 /*
   4  * Copyright (C) 2004, 2005, 2007, 2009  Internet Systems Consortium, Inc. ("ISC")
   5  * Copyright (C) 2000, 2001  Internet Software Consortium.
   6  *
   7  * Permission to use, copy, modify, and/or 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 WITH
  12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  17  * PERFORMANCE OF THIS SOFTWARE.
  18  */
  19
  20 /* Id: soa.c,v 1.12 2009/09/10 02:18:40 each Exp  */
  21
  22 /*! \file */
  23
  24 #include <config.h>
  25 #include <string.h>
  26
  27 #include <isc/buffer.h>
  28 #include <isc/util.h>
  29
  30 #include <dns/rdata.h>
  31 #include <dns/rdatastruct.h>
  32 #include <dns/soa.h>
  33
  34 static inline isc_uint32_t
  35 decode_uint32(unsigned char *p) {
  36         return ((p[0] << 24) +
  37                 (p[1] << 16) +
  38                 (p[2] <<  8) +
  39                 (p[3] <<  0));
  40 }
  41
  42 static inline void
  43 encode_uint32(isc_uint32_t val, unsigned char *p) {
  44         p[0] = (isc_uint8_t)(val >> 24);
  45         p[1] = (isc_uint8_t)(val >> 16);
  46         p[2] = (isc_uint8_t)(val >>  8);
  47         p[3] = (isc_uint8_t)(val >>  0);
  48 }
  49
  50 static isc_uint32_t
  51 soa_get(dns_rdata_t *rdata, int offset) {
  52         INSIST(rdata->type == dns_rdatatype_soa);
  53         /*
  54          * Locate the field within the SOA RDATA based
  55          * on its position relative to the end of the data.
  56          *
  57          * This is a bit of a kludge, but the alternative approach of
  58          * using dns_rdata_tostruct() and dns_rdata_fromstruct() would
  59          * involve a lot of unnecessary work (like building domain
  60          * names and allocating temporary memory) when all we really
  61          * want to do is to get 32 bits of fixed-sized data.
  62          */
  63         INSIST(rdata->length >= 20);
  64         INSIST(offset >= 0 && offset <= 16);
  65         return (decode_uint32(rdata->data + rdata->length - 20 + offset));
  66 }
  67
  68 isc_result_t
  69 dns_soa_buildrdata(dns_name_t *origin, dns_name_t *contact,
  70                    dns_rdataclass_t rdclass,
  71                    isc_uint32_t serial, isc_uint32_t refresh,
  72                    isc_uint32_t retry, isc_uint32_t expire,
  73                    isc_uint32_t minimum, unsigned char *buffer,
  74                    dns_rdata_t *rdata) {
  75         dns_rdata_soa_t soa;
  76         isc_buffer_t rdatabuf;
  77
  78         REQUIRE(origin != NULL);
  79         REQUIRE(contact != NULL);
  80
  81         memset(buffer, 0, DNS_SOA_BUFFERSIZE);
  82         isc_buffer_init(&rdatabuf, buffer, DNS_SOA_BUFFERSIZE);
  83
  84         soa.common.rdtype = dns_rdatatype_soa;
  85         soa.common.rdclass = rdclass;
  86         soa.mctx = NULL;
  87         soa.serial = serial;
  88         soa.refresh = refresh;
  89         soa.retry = retry;
  90         soa.expire = expire;
  91         soa.minimum = minimum;
  92         dns_name_init(&soa.origin, NULL);
  93         dns_name_clone(origin, &soa.origin);
  94         dns_name_init(&soa.contact, NULL);
  95         dns_name_clone(contact, &soa.contact);
  96
  97         return (dns_rdata_fromstruct(rdata, rdclass, dns_rdatatype_soa,
  98                                       &soa, &rdatabuf));
  99 }
 100
 101 isc_uint32_t
 102 dns_soa_getserial(dns_rdata_t *rdata) {
 103         return soa_get(rdata, 0);
 104 }
 105 isc_uint32_t
 106 dns_soa_getrefresh(dns_rdata_t *rdata) {
 107         return soa_get(rdata, 4);
 108 }
 109 isc_uint32_t
 110 dns_soa_getretry(dns_rdata_t *rdata) {
 111         return soa_get(rdata, 8);
 112 }
 113 isc_uint32_t
 114 dns_soa_getexpire(dns_rdata_t *rdata) {
 115         return soa_get(rdata, 12);
 116 }
 117 isc_uint32_t
 118 dns_soa_getminimum(dns_rdata_t *rdata) {
 119         return soa_get(rdata, 16);
 120 }
 121
 122 static void
 123 soa_set(dns_rdata_t *rdata, isc_uint32_t val, int offset) {
 124         INSIST(rdata->type == dns_rdatatype_soa);
 125         INSIST(rdata->length >= 20);
 126         INSIST(offset >= 0 && offset <= 16);
 127         encode_uint32(val, rdata->data + rdata->length - 20 + offset);
 128 }
 129
 130 void
 131 dns_soa_setserial(isc_uint32_t val, dns_rdata_t *rdata) {
 132         soa_set(rdata, val, 0);
 133 }
 134 void
 135 dns_soa_setrefresh(isc_uint32_t val, dns_rdata_t *rdata) {
 136         soa_set(rdata, val, 4);
 137 }
 138 void
 139 dns_soa_setretry(isc_uint32_t val, dns_rdata_t *rdata) {
 140         soa_set(rdata, val, 8);
 141 }
 142 void
 143 dns_soa_setexpire(isc_uint32_t val, dns_rdata_t *rdata) {
 144         soa_set(rdata, val, 12);
 145 }
 146 void
 147 dns_soa_setminimum(isc_uint32_t val, dns_rdata_t *rdata) {
 148         soa_set(rdata, val, 16);
 149 }