/*

 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * SPDX-License-Identifier: MPL-2.0

 *

 * 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 https://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

/*! \file */

#include <inttypes.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 uint32_t

decode_uint32(unsigned char *p) {

  return ((uint32_t)p[0] << 24) + ((uint32_t)p[1] << 16) +

         ((uint32_t)p[2] << 8) + ((uint32_t)p[3] << 0);

}

static void

encode_uint32(uint32_t val, unsigned char *p) {

  p[0] = (uint8_t)(val >> 24);

  p[1] = (uint8_t)(val >> 16);

  p[2] = (uint8_t)(val >> 8);

  p[3] = (uint8_t)(val >> 0);

}

static 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(const dns_name_t *origin, const dns_name_t *contact,

       dns_rdataclass_t rdclass, uint32_t serial, uint32_t refresh,

       uint32_t retry, uint32_t expire, 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);

  dns_name_clone(origin, &soa.origin);

  dns_name_init(&soa.contact);

  dns_name_clone(contact, &soa.contact);

  return dns_rdata_fromstruct(rdata, rdclass, dns_rdatatype_soa, &soa,

            &rdatabuf);

}

uint32_t

dns_soa_getserial(dns_rdata_t *rdata) {

  return soa_get(rdata, 0);

}

uint32_t

dns_soa_getrefresh(dns_rdata_t *rdata) {

  return soa_get(rdata, 4);

}

uint32_t

dns_soa_getretry(dns_rdata_t *rdata) {

  return soa_get(rdata, 8);

}

uint32_t

dns_soa_getexpire(dns_rdata_t *rdata) {

  return soa_get(rdata, 12);

}

uint32_t

dns_soa_getminimum(dns_rdata_t *rdata) {

  return soa_get(rdata, 16);

}

static void

soa_set(dns_rdata_t *rdata, 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(uint32_t val, dns_rdata_t *rdata) {

  soa_set(rdata, val, 0);

}

void

dns_soa_setrefresh(uint32_t val, dns_rdata_t *rdata) {

  soa_set(rdata, val, 4);

}

void

dns_soa_setretry(uint32_t val, dns_rdata_t *rdata) {

  soa_set(rdata, val, 8);

}

void

dns_soa_setexpire(uint32_t val, dns_rdata_t *rdata) {

  soa_set(rdata, val, 12);

}

void

dns_soa_setminimum(uint32_t val, dns_rdata_t *rdata) {

  soa_set(rdata, val, 16);

}