/*
* Copyright (C) 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 https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#ifndef DNS_DNS64_H
#define DNS_DNS64_H 1
#include <stdbool.h>
#include <isc/lang.h>
#include <dns/types.h>
ISC_LANG_BEGINDECLS
/*
* dns_dns64_create() flags.
*/
#define DNS_DNS64_RECURSIVE_ONLY 0x01 /* If set then this record
* only applies to recursive
* queries.
*/
#define DNS_DNS64_BREAK_DNSSEC 0x02 /* If set then still perform
* DNSSEC synthesis even
* though the result would
* fail validation.
*/
/*
* dns_dns64_aaaaok() and dns_dns64_aaaafroma() flags.
*/
#define DNS_DNS64_RECURSIVE 0x01 /* Recursive query. */
#define DNS_DNS64_DNSSEC 0x02 /* DNSSEC sensitive query. */
isc_result_t
dns_dns64_create(isc_mem_t *mctx, isc_netaddr_t *prefix,
unsigned int prefixlen, isc_netaddr_t *suffix,
dns_acl_t *client, dns_acl_t *mapped, dns_acl_t *excluded,
unsigned int flags, dns_dns64_t **dns64);
/*
* Create a dns64 record which is used to identify the set of clients
* it applies to and how to perform the DNS64 synthesis.
*
* 'prefix' and 'prefixlen' defined the leading bits of the AAAA records
* to be synthesised. 'suffix' defines the bits after the A records bits.
* If suffix is NULL zeros will be used for these bits. 'client' defines
* for which clients this record applies. If 'client' is NULL then all
* clients apply. 'mapped' defines which A records are candidated for
* mapping. If 'mapped' is NULL then all A records will be mapped.
* 'excluded' defines which AAAA are to be treated as non-existent for the
* purposed of determining whether to perform synthesis. If 'excluded' is
* NULL then no AAAA records prevent synthesis.
*
* If DNS_DNS64_RECURSIVE_ONLY is set then the record will only match if
* DNS_DNS64_RECURSIVE is set when calling dns_dns64_aaaaok() and
* dns_dns64_aaaafroma().
*
* If DNS_DNS64_BREAK_DNSSEC is set then the record will still apply if
* DNS_DNS64_DNSSEC is set when calling dns_dns64_aaaaok() and
* dns_dns64_aaaafroma() otherwise the record will be ignored.
*
* Requires:
* 'mctx' to be valid.
* 'prefix' to be valid and the address family to AF_INET6.
* 'prefixlen' to be one of 32, 40, 48, 56, 72 and 96.
* the bits not covered by prefixlen in prefix to
* be zero.
* 'suffix' to be NULL or the address family be set to AF_INET6
* and the leading 'prefixlen' + 32 bits of the 'suffix'
* to be zero. If 'prefixlen' is 40, 48 or 56 then the
* the leading 'prefixlen' + 40 bits of 'suffix' must be
* zero.
* 'client' to be NULL or a valid acl.
* 'mapped' to be NULL or a valid acl.
* 'excluded' to be NULL or a valid acl.
*
* Returns:
* ISC_R_SUCCESS
* ISC_R_NOMEMORY
*/
void
dns_dns64_destroy(dns_dns64_t **dns64p);
/*
* Destroys a dns64 record.
*
* Requires the record to not be linked.
*/
isc_result_t
dns_dns64_aaaafroma(const dns_dns64_t *dns64, const isc_netaddr_t *reqaddr,
const dns_name_t *reqsigner, const dns_aclenv_t *env,
unsigned int flags, unsigned char *a, unsigned char *aaaa);
/*
* dns_dns64_aaaafroma() determines whether to perform a DNS64 address
* synthesis from 'a' based on 'dns64', 'reqaddr', 'reqsigner', 'env',
* 'flags' and 'aaaa'. If synthesis is performed then the result is
* written to '*aaaa'.
*
* The synthesised address will be of the form:
*
* <prefix bits><a bits><suffix bits>
*
* If <a bits> straddle bits 64-71 of the AAAA record, then 8 zero bits will
* be inserted at bits 64-71.
*
* Requires:
* 'dns64' to be valid.
* 'reqaddr' to be valid.
* 'reqsigner' to be NULL or valid.
* 'env' to be valid.
* 'a' to point to a IPv4 address in network order.
* 'aaaa' to point to a IPv6 address buffer in network order.
*
* Returns:
* ISC_R_SUCCESS if synthesis was performed.
* DNS_R_DISALLOWED if there is no match.
*/
dns_dns64_t *
dns_dns64_next(dns_dns64_t *dns64);
/*
* Return the next dns64 record in the list.
*/
void
dns_dns64_append(dns_dns64list_t *list, dns_dns64_t *dns64);
/*
* Append the dns64 record to the list.
*/
void
dns_dns64_unlink(dns_dns64list_t *list, dns_dns64_t *dns64);
/*
* Unlink the dns64 record from the list.
*/
bool
dns_dns64_aaaaok(const dns_dns64_t *dns64, const isc_netaddr_t *reqaddr,
const dns_name_t *reqsigner, const dns_aclenv_t *env,
unsigned int flags, dns_rdataset_t *rdataset,
bool *aaaaok, size_t aaaaoklen);
/*
* Determine if there are any non-excluded AAAA records in from the
* matching dns64 records in the list starting at 'dns64'. If there
* is a non-excluded address return true. If all addresses are
* excluded in the matched records return false. If no records
* match then return true.
*
* If aaaaok is defined then dns_dns64_aaaaok() return a array of which
* addresses in 'rdataset' were deemed to not be exclude by any matching
* record. If there are no matching records then all entries are set
* to true.
*
* Requires
* 'rdataset' to be valid and to be for type AAAA and class IN.
* 'aaaaoklen' must match the number of records in 'rdataset'
* if 'aaaaok' in non NULL.
*/
ISC_LANG_ENDDECLS
#endif /* DNS_DNS64_H */
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