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bind9/lib/dns/ecs.c
Daniel Baumann f66ff7eae6
Adding upstream version 1:9.20.9.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-21 13:32:37 +02:00

112 lines
2.4 KiB
C

/*
* 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 <string.h>
#include <isc/buffer.h>
#include <isc/mem.h>
#include <isc/netaddr.h>
#include <isc/util.h>
#include <dns/ecs.h>
#include <dns/nsec.h>
#include <dns/rbt.h>
#include <dns/rdata.h>
#include <dns/rdatatype.h>
#include <dns/result.h>
#include <dns/types.h>
void
dns_ecs_init(dns_ecs_t *ecs) {
isc_netaddr_unspec(&ecs->addr);
ecs->source = 0;
ecs->scope = 0xff;
}
bool
dns_ecs_equals(const dns_ecs_t *ecs1, const dns_ecs_t *ecs2) {
const unsigned char *addr1, *addr2;
uint8_t mask;
size_t alen;
REQUIRE(ecs1 != NULL && ecs2 != NULL);
if (ecs1->source != ecs2->source ||
ecs1->addr.family != ecs2->addr.family)
{
return false;
}
alen = (ecs1->source + 7) / 8;
if (alen == 0) {
return true;
}
switch (ecs1->addr.family) {
case AF_INET:
INSIST(alen <= 4);
addr1 = (const unsigned char *)&ecs1->addr.type.in;
addr2 = (const unsigned char *)&ecs2->addr.type.in;
break;
case AF_INET6:
INSIST(alen <= 16);
addr1 = (const unsigned char *)&ecs1->addr.type.in6;
addr2 = (const unsigned char *)&ecs2->addr.type.in6;
break;
default:
UNREACHABLE();
}
/*
* Compare all octets except the final octet of the address
* prefix.
*/
if (alen > 1 && memcmp(addr1, addr2, alen - 1) != 0) {
return false;
}
/*
* It should not be necessary to mask the final octet; all
* bits past the source prefix length are supposed to be 0.
* However, it seems prudent not to omit them from the
* comparison anyway.
*/
mask = (~0U << (8 - (ecs1->source % 8))) & 0xff;
if (mask == 0) {
mask = 0xff;
}
if ((addr1[alen - 1] & mask) != (addr2[alen - 1] & mask)) {
return false;
}
return true;
}
void
dns_ecs_format(const dns_ecs_t *ecs, char *buf, size_t size) {
size_t len;
char *p;
REQUIRE(ecs != NULL);
REQUIRE(buf != NULL);
REQUIRE(size >= DNS_ECS_FORMATSIZE);
isc_netaddr_format(&ecs->addr, buf, size);
len = strlen(buf);
p = buf + len;
snprintf(p, size - len, "/%d/%d", ecs->source,
ecs->scope == 0xff ? 0 : ecs->scope);
}