1174294Sobrien/* $NetBSD: ecs.c,v 1.1 2024/02/18 20:57:31 christos Exp $ */ 2174294Sobrien 3174294Sobrien/* 4174294Sobrien * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 5174294Sobrien * 6174294Sobrien * SPDX-License-Identifier: MPL-2.0 7174294Sobrien * 8174294Sobrien * This Source Code Form is subject to the terms of the Mozilla Public 9174294Sobrien * License, v. 2.0. If a copy of the MPL was not distributed with this 10174294Sobrien * file, you can obtain one at https://mozilla.org/MPL/2.0/. 11174294Sobrien * 12174294Sobrien * See the COPYRIGHT file distributed with this work for additional 13174294Sobrien * information regarding copyright ownership. 14174294Sobrien */ 15174294Sobrien 16174294Sobrien/*! \file */ 17174294Sobrien 18174294Sobrien#include <string.h> 19174294Sobrien 20174294Sobrien#include <isc/buffer.h> 21174294Sobrien#include <isc/mem.h> 22174294Sobrien#include <isc/netaddr.h> 23174294Sobrien#include <isc/print.h> 24174294Sobrien#include <isc/util.h> 25174294Sobrien 26174294Sobrien#include <dns/ecs.h> 27174294Sobrien#include <dns/nsec.h> 28174294Sobrien#include <dns/rbt.h> 29174294Sobrien#include <dns/rdata.h> 30174294Sobrien#include <dns/rdatatype.h> 31174294Sobrien#include <dns/result.h> 32174294Sobrien#include <dns/types.h> 33174294Sobrien 34174294Sobrienvoid 35174294Sobriendns_ecs_init(dns_ecs_t *ecs) { 36174294Sobrien isc_netaddr_unspec(&ecs->addr); 37174294Sobrien ecs->source = 0; 38174294Sobrien ecs->scope = 0xff; 39174294Sobrien} 40174294Sobrien 41174294Sobrienbool 42174294Sobriendns_ecs_equals(const dns_ecs_t *ecs1, const dns_ecs_t *ecs2) { 43174294Sobrien const unsigned char *addr1, *addr2; 44174294Sobrien uint8_t mask; 45174294Sobrien size_t alen; 46174294Sobrien 47174294Sobrien REQUIRE(ecs1 != NULL && ecs2 != NULL); 48174294Sobrien 49174294Sobrien if (ecs1->source != ecs2->source || 50174294Sobrien ecs1->addr.family != ecs2->addr.family) 51174294Sobrien { 52174294Sobrien return (false); 53174294Sobrien } 54174294Sobrien 55174294Sobrien alen = (ecs1->source + 7) / 8; 56174294Sobrien if (alen == 0) { 57174294Sobrien return (true); 58174294Sobrien } 59174294Sobrien 60174294Sobrien switch (ecs1->addr.family) { 61174294Sobrien case AF_INET: 62174294Sobrien INSIST(alen <= 4); 63174294Sobrien addr1 = (const unsigned char *)&ecs1->addr.type.in; 64174294Sobrien addr2 = (const unsigned char *)&ecs2->addr.type.in; 65174294Sobrien break; 66174294Sobrien case AF_INET6: 67174294Sobrien INSIST(alen <= 16); 68174294Sobrien addr1 = (const unsigned char *)&ecs1->addr.type.in6; 69174294Sobrien addr2 = (const unsigned char *)&ecs2->addr.type.in6; 70174294Sobrien break; 71174294Sobrien default: 72174294Sobrien UNREACHABLE(); 73174294Sobrien } 74174294Sobrien 75174294Sobrien /* 76174294Sobrien * Compare all octets except the final octet of the address 77174294Sobrien * prefix. 78174294Sobrien */ 79174294Sobrien if (alen > 1 && memcmp(addr1, addr2, alen - 1) != 0) { 80174294Sobrien return (false); 81174294Sobrien } 82174294Sobrien 83174294Sobrien /* 84174294Sobrien * It should not be necessary to mask the final octet; all 85174294Sobrien * bits past the source prefix length are supposed to be 0. 86174294Sobrien * However, it seems prudent not to omit them from the 87174294Sobrien * comparison anyway. 88174294Sobrien */ 89174294Sobrien mask = (~0U << (8 - (ecs1->source % 8))) & 0xff; 90174294Sobrien if (mask == 0) { 91174294Sobrien mask = 0xff; 92174294Sobrien } 93174294Sobrien 94174294Sobrien if ((addr1[alen - 1] & mask) != (addr2[alen - 1] & mask)) { 95174294Sobrien return (false); 96174294Sobrien } 97174294Sobrien 98174294Sobrien return (true); 99174294Sobrien} 100174294Sobrien 101174294Sobrienvoid 102174294Sobriendns_ecs_format(const dns_ecs_t *ecs, char *buf, size_t size) { 103174294Sobrien size_t len; 104174294Sobrien char *p; 105174294Sobrien 106174294Sobrien REQUIRE(ecs != NULL); 107174294Sobrien REQUIRE(buf != NULL); 108174294Sobrien REQUIRE(size >= DNS_ECS_FORMATSIZE); 109174294Sobrien 110174294Sobrien isc_netaddr_format(&ecs->addr, buf, size); 111174294Sobrien len = strlen(buf); 112174294Sobrien p = buf + len; 113174294Sobrien snprintf(p, size - len, "/%d/%d", ecs->source, 114174294Sobrien ecs->scope == 0xff ? 0 : ecs->scope); 115174294Sobrien} 116174294Sobrien