soa.c revision 0c27b3fe77ac1d5094ba3521e8142d9e7973133f
/*
* Copyright (C) 2000, 2001, 2004, 2005, 2007, 2009, 2016 Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/* $Id: soa.c,v 1.12 2009/09/10 02:18:40 each Exp $ */
/*! \file */
#include <config.h>
#include <string.h>
#include <isc/buffer.h>
#include <isc/util.h>
#include <dns/rdata.h>
#include <dns/rdatastruct.h>
#include <dns/soa.h>
static inline isc_uint32_t
decode_uint32(unsigned char *p) {
return ((p[0] << 24) +
(p[1] << 16) +
(p[2] << 8) +
(p[3] << 0));
}
static inline void
encode_uint32(isc_uint32_t val, unsigned char *p) {
p[0] = (isc_uint8_t)(val >> 24);
p[1] = (isc_uint8_t)(val >> 16);
p[2] = (isc_uint8_t)(val >> 8);
p[3] = (isc_uint8_t)(val >> 0);
}
static isc_uint32_t
soa_get(dns_rdata_t *rdata, int offset) {
INSIST(rdata->type == dns_rdatatype_soa);
/*
* Locate the field within the SOA RDATA based
* on its position relative to the end of the data.
*
* This is a bit of a kludge, but the alternative approach of
* using dns_rdata_tostruct() and dns_rdata_fromstruct() would
* involve a lot of unnecessary work (like building domain
* names and allocating temporary memory) when all we really
* want to do is to get 32 bits of fixed-sized data.
*/
INSIST(rdata->length >= 20);
INSIST(offset >= 0 && offset <= 16);
return (decode_uint32(rdata->data + rdata->length - 20 + offset));
}
isc_result_t
dns_soa_buildrdata(dns_name_t *origin, dns_name_t *contact,
dns_rdataclass_t rdclass,
isc_uint32_t serial, isc_uint32_t refresh,
isc_uint32_t retry, isc_uint32_t expire,
isc_uint32_t minimum, unsigned char *buffer,
dns_rdata_t *rdata) {
dns_rdata_soa_t soa;
isc_buffer_t rdatabuf;
REQUIRE(origin != NULL);
REQUIRE(contact != NULL);
memset(buffer, 0, DNS_SOA_BUFFERSIZE);
isc_buffer_init(&rdatabuf, buffer, DNS_SOA_BUFFERSIZE);
soa.common.rdtype = dns_rdatatype_soa;
soa.common.rdclass = rdclass;
soa.mctx = NULL;
soa.serial = serial;
soa.refresh = refresh;
soa.retry = retry;
soa.expire = expire;
soa.minimum = minimum;
dns_name_init(&soa.origin, NULL);
dns_name_clone(origin, &soa.origin);
dns_name_init(&soa.contact, NULL);
dns_name_clone(contact, &soa.contact);
return (dns_rdata_fromstruct(rdata, rdclass, dns_rdatatype_soa,
&soa, &rdatabuf));
}
isc_uint32_t
dns_soa_getserial(dns_rdata_t *rdata) {
return soa_get(rdata, 0);
}
isc_uint32_t
dns_soa_getrefresh(dns_rdata_t *rdata) {
return soa_get(rdata, 4);
}
isc_uint32_t
dns_soa_getretry(dns_rdata_t *rdata) {
return soa_get(rdata, 8);
}
isc_uint32_t
dns_soa_getexpire(dns_rdata_t *rdata) {
return soa_get(rdata, 12);
}
isc_uint32_t
dns_soa_getminimum(dns_rdata_t *rdata) {
return soa_get(rdata, 16);
}
static void
soa_set(dns_rdata_t *rdata, isc_uint32_t val, int offset) {
INSIST(rdata->type == dns_rdatatype_soa);
INSIST(rdata->length >= 20);
INSIST(offset >= 0 && offset <= 16);
encode_uint32(val, rdata->data + rdata->length - 20 + offset);
}
void
dns_soa_setserial(isc_uint32_t val, dns_rdata_t *rdata) {
soa_set(rdata, val, 0);
}
void
dns_soa_setrefresh(isc_uint32_t val, dns_rdata_t *rdata) {
soa_set(rdata, val, 4);
}
void
dns_soa_setretry(isc_uint32_t val, dns_rdata_t *rdata) {
soa_set(rdata, val, 8);
}
void
dns_soa_setexpire(isc_uint32_t val, dns_rdata_t *rdata) {
soa_set(rdata, val, 12);
}
void
dns_soa_setminimum(isc_uint32_t val, dns_rdata_t *rdata) {
soa_set(rdata, val, 16);
}