/* $NetBSD: rdataset.c,v 1.7 2022/09/23 12:15:30 christos Exp $ */
/*
* 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 <stdbool.h>
#include <stdlib.h>
#include <isc/buffer.h>
#include <isc/mem.h>
#include <isc/random.h>
#include <isc/serial.h>
#include <isc/util.h>
#include <dns/compress.h>
#include <dns/fixedname.h>
#include <dns/name.h>
#include <dns/ncache.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
static const char *trustnames[] = {
"none", "pending-additional",
"pending-answer", "additional",
"glue", "answer",
"authauthority", "authanswer",
"secure", "local" /* aka ultimate */
};
const char *
dns_trust_totext(dns_trust_t trust) {
if (trust >= sizeof(trustnames) / sizeof(*trustnames)) {
return ("bad");
}
return (trustnames[trust]);
}
#define DNS_RDATASET_COUNT_UNDEFINED UINT32_MAX
void
dns_rdataset_init(dns_rdataset_t *rdataset) {
/*
* Make 'rdataset' a valid, disassociated rdataset.
*/
REQUIRE(rdataset != NULL);
rdataset->magic = DNS_RDATASET_MAGIC;
rdataset->methods = NULL;
ISC_LINK_INIT(rdataset, link);
rdataset->rdclass = 0;
rdataset->type = 0;
rdataset->ttl = 0;
rdataset->trust = 0;
rdataset->covers = 0;
rdataset->attributes = 0;
rdataset->count = DNS_RDATASET_COUNT_UNDEFINED;
rdataset->private1 = NULL;
rdataset->private2 = NULL;
rdataset->private3 = NULL;
rdataset->privateuint4 = 0;
rdataset->private5 = NULL;
rdataset->private6 = NULL;
rdataset->private7 = NULL;
rdataset->resign = 0;
}
void
dns_rdataset_invalidate(dns_rdataset_t *rdataset) {
/*
* Invalidate 'rdataset'.
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods == NULL);
rdataset->magic = 0;
ISC_LINK_INIT(rdataset, link);
rdataset->rdclass = 0;
rdataset->type = 0;
rdataset->ttl = 0;
rdataset->trust = 0;
rdataset->covers = 0;
rdataset->attributes = 0;
rdataset->count = DNS_RDATASET_COUNT_UNDEFINED;
rdataset->private1 = NULL;
rdataset->private2 = NULL;
rdataset->private3 = NULL;
rdataset->privateuint4 = 0;
rdataset->private5 = NULL;
}
void
dns_rdataset_disassociate(dns_rdataset_t *rdataset) {
/*
* Disassociate 'rdataset' from its rdata, allowing it to be reused.
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
(rdataset->methods->disassociate)(rdataset);
rdataset->methods = NULL;
ISC_LINK_INIT(rdataset, link);
rdataset->rdclass = 0;
rdataset->type = 0;
rdataset->ttl = 0;
rdataset->trust = 0;
rdataset->covers = 0;
rdataset->attributes = 0;
rdataset->count = DNS_RDATASET_COUNT_UNDEFINED;
rdataset->private1 = NULL;
rdataset->private2 = NULL;
rdataset->private3 = NULL;
rdataset->privateuint4 = 0;
rdataset->private5 = NULL;
rdataset->private6 = NULL;
}
bool
dns_rdataset_isassociated(dns_rdataset_t *rdataset) {
/*
* Is 'rdataset' associated?
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
if (rdataset->methods != NULL) {
return (true);
}
return (false);
}
static void
question_disassociate(dns_rdataset_t *rdataset) {
UNUSED(rdataset);
}
static isc_result_t
question_cursor(dns_rdataset_t *rdataset) {
UNUSED(rdataset);
return (ISC_R_NOMORE);
}
static void
question_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata) {
/*
* This routine should never be called.
*/
UNUSED(rdataset);
UNUSED(rdata);
REQUIRE(0);
}
static void
question_clone(dns_rdataset_t *source, dns_rdataset_t *target) {
*target = *source;
}
static unsigned int
question_count(dns_rdataset_t *rdataset) {
/*
* This routine should never be called.
*/
UNUSED(rdataset);
REQUIRE(0);
return (0);
}
static dns_rdatasetmethods_t question_methods = {
question_disassociate,
question_cursor,
question_cursor,
question_current,
question_clone,
question_count,
NULL, /* addnoqname */
NULL, /* getnoqname */
NULL, /* addclosest */
NULL, /* getclosest */
NULL, /* settrust */
NULL, /* expire */
NULL, /* clearprefetch */
NULL, /* setownercase */
NULL, /* getownercase */
NULL /* addglue */
};
void
dns_rdataset_makequestion(dns_rdataset_t *rdataset, dns_rdataclass_t rdclass,
dns_rdatatype_t type) {
/*
* Make 'rdataset' a valid, associated, question rdataset, with a
* question class of 'rdclass' and type 'type'.
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods == NULL);
rdataset->methods = &question_methods;
rdataset->rdclass = rdclass;
rdataset->type = type;
rdataset->attributes |= DNS_RDATASETATTR_QUESTION;
}
unsigned int
dns_rdataset_count(dns_rdataset_t *rdataset) {
/*
* Return the number of records in 'rdataset'.
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
return ((rdataset->methods->count)(rdataset));
}
void
dns_rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target) {
/*
* Make 'target' refer to the same rdataset as 'source'.
*/
REQUIRE(DNS_RDATASET_VALID(source));
REQUIRE(source->methods != NULL);
REQUIRE(DNS_RDATASET_VALID(target));
REQUIRE(target->methods == NULL);
(source->methods->clone)(source, target);
}
isc_result_t
dns_rdataset_first(dns_rdataset_t *rdataset) {
/*
* Move the rdata cursor to the first rdata in the rdataset (if any).
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
return ((rdataset->methods->first)(rdataset));
}
isc_result_t
dns_rdataset_next(dns_rdataset_t *rdataset) {
/*
* Move the rdata cursor to the next rdata in the rdataset (if any).
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
return ((rdataset->methods->next)(rdataset));
}
void
dns_rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata) {
/*
* Make 'rdata' refer to the current rdata.
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
(rdataset->methods->current)(rdataset, rdata);
}
#define MAX_SHUFFLE 32
#define WANT_FIXED(r) (((r)->attributes & DNS_RDATASETATTR_FIXEDORDER) != 0)
#define WANT_RANDOM(r) (((r)->attributes & DNS_RDATASETATTR_RANDOMIZE) != 0)
#define WANT_CYCLIC(r) (((r)->attributes & DNS_RDATASETATTR_CYCLIC) != 0)
struct towire_sort {
int key;
dns_rdata_t *rdata;
};
static int
towire_compare(const void *av, const void *bv) {
const struct towire_sort *a = (const struct towire_sort *)av;
const struct towire_sort *b = (const struct towire_sort *)bv;
return (a->key - b->key);
}
static void
swap_rdata(dns_rdata_t *in, unsigned int a, unsigned int b) {
dns_rdata_t rdata = in[a];
in[a] = in[b];
in[b] = rdata;
}
static isc_result_t
towiresorted(dns_rdataset_t *rdataset, const dns_name_t *owner_name,
dns_compress_t *cctx, isc_buffer_t *target,
dns_rdatasetorderfunc_t order, const void *order_arg, bool partial,
unsigned int options, unsigned int *countp, void **state) {
isc_region_t r;
isc_result_t result;
unsigned int i, count = 0, added;
isc_buffer_t savedbuffer, rdlen, rrbuffer;
unsigned int headlen;
bool question = false;
bool shuffle = false, sort = false;
bool want_random, want_cyclic;
dns_rdata_t in_fixed[MAX_SHUFFLE];
dns_rdata_t *in = in_fixed;
struct towire_sort out_fixed[MAX_SHUFFLE];
struct towire_sort *out = out_fixed;
dns_fixedname_t fixed;
dns_name_t *name;
uint16_t offset;
UNUSED(state);
/*
* Convert 'rdataset' to wire format, compressing names as specified
* in cctx, and storing the result in 'target'.
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
REQUIRE(countp != NULL);
REQUIRE(cctx != NULL && cctx->mctx != NULL);
want_random = WANT_RANDOM(rdataset);
want_cyclic = WANT_CYCLIC(rdataset);
if ((rdataset->attributes & DNS_RDATASETATTR_QUESTION) != 0) {
question = true;
count = 1;
result = dns_rdataset_first(rdataset);
INSIST(result == ISC_R_NOMORE);
} else if ((rdataset->attributes & DNS_RDATASETATTR_NEGATIVE) != 0) {
/*
* This is a negative caching rdataset.
*/
unsigned int ncache_opts = 0;
if ((options & DNS_RDATASETTOWIRE_OMITDNSSEC) != 0) {
ncache_opts |= DNS_NCACHETOWIRE_OMITDNSSEC;
}
return (dns_ncache_towire(rdataset, cctx, target, ncache_opts,
countp));
} else {
count = (rdataset->methods->count)(rdataset);
result = dns_rdataset_first(rdataset);
if (result == ISC_R_NOMORE) {
return (ISC_R_SUCCESS);
}
if (result != ISC_R_SUCCESS) {
return (result);
}
}
/*
* Do we want to sort and/or shuffle this answer?
*/
if (!question && count > 1 && rdataset->type != dns_rdatatype_rrsig) {
if (order != NULL) {
sort = true;
}
if (want_random || want_cyclic) {
shuffle = true;
}
}
if ((shuffle || sort)) {
if (count > MAX_SHUFFLE) {
in = isc_mem_get(cctx->mctx, count * sizeof(*in));
out = isc_mem_get(cctx->mctx, count * sizeof(*out));
if (in == NULL || out == NULL) {
shuffle = sort = false;
}
}
}
if ((shuffle || sort)) {
uint32_t seed = 0;
unsigned int j = 0;
/*
* First we get handles to all of the rdata.
*/
i = 0;
do {
INSIST(i < count);
dns_rdata_init(&in[i]);
dns_rdataset_current(rdataset, &in[i]);
i++;
result = dns_rdataset_next(rdataset);
} while (result == ISC_R_SUCCESS);
if (result != ISC_R_NOMORE) {
goto cleanup;
}
INSIST(i == count);
if (ISC_LIKELY(want_random)) {
seed = isc_random32();
}
if (ISC_UNLIKELY(want_cyclic) &&
(rdataset->count != DNS_RDATASET_COUNT_UNDEFINED))
{
j = rdataset->count % count;
}
for (i = 0; i < count; i++) {
if (ISC_LIKELY(want_random)) {
swap_rdata(in, j, j + seed % (count - j));
}
out[i].key = (sort) ? (*order)(&in[j], order_arg) : 0;
out[i].rdata = &in[j];
if (++j == count) {
j = 0;
}
}
/*
* Sortlist order.
*/
if (sort) {
qsort(out, count, sizeof(out[0]), towire_compare);
}
}
savedbuffer = *target;
i = 0;
added = 0;
name = dns_fixedname_initname(&fixed);
dns_name_copynf(owner_name, name);
dns_rdataset_getownercase(rdataset, name);
offset = 0xffff;
name->attributes |= owner_name->attributes & DNS_NAMEATTR_NOCOMPRESS;
do {
/*
* Copy out the name, type, class, ttl.
*/
rrbuffer = *target;
dns_compress_setmethods(cctx, DNS_COMPRESS_GLOBAL14);
result = dns_name_towire2(name, cctx, target, &offset);
if (result != ISC_R_SUCCESS) {
goto rollback;
}
headlen = sizeof(dns_rdataclass_t) + sizeof(dns_rdatatype_t);
if (!question) {
headlen += sizeof(dns_ttl_t) + 2;
} /* XXX 2 for rdata len
*/
isc_buffer_availableregion(target, &r);
if (r.length < headlen) {
result = ISC_R_NOSPACE;
goto rollback;
}
isc_buffer_putuint16(target, rdataset->type);
isc_buffer_putuint16(target, rdataset->rdclass);
if (!question) {
dns_rdata_t rdata = DNS_RDATA_INIT;
isc_buffer_putuint32(target, rdataset->ttl);
/*
* Save space for rdlen.
*/
rdlen = *target;
isc_buffer_add(target, 2);
/*
* Copy out the rdata
*/
if (shuffle || sort) {
rdata = *(out[i].rdata);
} else {
dns_rdata_reset(&rdata);
dns_rdataset_current(rdataset, &rdata);
}
result = dns_rdata_towire(&rdata, cctx, target);
if (result != ISC_R_SUCCESS) {
goto rollback;
}
INSIST((target->used >= rdlen.used + 2) &&
(target->used - rdlen.used - 2 < 65536));
isc_buffer_putuint16(
&rdlen,
(uint16_t)(target->used - rdlen.used - 2));
added++;
}
if (shuffle || sort) {
i++;
if (i == count) {
result = ISC_R_NOMORE;
} else {
result = ISC_R_SUCCESS;
}
} else {
result = dns_rdataset_next(rdataset);
}
} while (result == ISC_R_SUCCESS);
if (result != ISC_R_NOMORE) {
goto rollback;
}
*countp += count;
result = ISC_R_SUCCESS;
goto cleanup;
rollback:
if (partial && result == ISC_R_NOSPACE) {
INSIST(rrbuffer.used < 65536);
dns_compress_rollback(cctx, (uint16_t)rrbuffer.used);
*countp += added;
*target = rrbuffer;
goto cleanup;
}
INSIST(savedbuffer.used < 65536);
dns_compress_rollback(cctx, (uint16_t)savedbuffer.used);
*countp = 0;
*target = savedbuffer;
cleanup:
if (out != NULL && out != out_fixed) {
isc_mem_put(cctx->mctx, out, count * sizeof(*out));
}
if (in != NULL && in != in_fixed) {
isc_mem_put(cctx->mctx, in, count * sizeof(*in));
}
return (result);
}
isc_result_t
dns_rdataset_towiresorted(dns_rdataset_t *rdataset,
const dns_name_t *owner_name, dns_compress_t *cctx,
isc_buffer_t *target, dns_rdatasetorderfunc_t order,
const void *order_arg, unsigned int options,
unsigned int *countp) {
return (towiresorted(rdataset, owner_name, cctx, target, order,
order_arg, false, options, countp, NULL));
}
isc_result_t
dns_rdataset_towirepartial(dns_rdataset_t *rdataset,
const dns_name_t *owner_name, dns_compress_t *cctx,
isc_buffer_t *target, dns_rdatasetorderfunc_t order,
const void *order_arg, unsigned int options,
unsigned int *countp, void **state) {
REQUIRE(state == NULL); /* XXX remove when implemented */
return (towiresorted(rdataset, owner_name, cctx, target, order,
order_arg, true, options, countp, state));
}
isc_result_t
dns_rdataset_towire(dns_rdataset_t *rdataset, const dns_name_t *owner_name,
dns_compress_t *cctx, isc_buffer_t *target,
unsigned int options, unsigned int *countp) {
return (towiresorted(rdataset, owner_name, cctx, target, NULL, NULL,
false, options, countp, NULL));
}
isc_result_t
dns_rdataset_additionaldata(dns_rdataset_t *rdataset,
dns_additionaldatafunc_t add, void *arg) {
dns_rdata_t rdata = DNS_RDATA_INIT;
isc_result_t result;
/*
* For each rdata in rdataset, call 'add' for each name and type in the
* rdata which is subject to additional section processing.
*/
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE((rdataset->attributes & DNS_RDATASETATTR_QUESTION) == 0);
result = dns_rdataset_first(rdataset);
if (result != ISC_R_SUCCESS) {
return (result);
}
do {
dns_rdataset_current(rdataset, &rdata);
result = dns_rdata_additionaldata(&rdata, add, arg);
if (result == ISC_R_SUCCESS) {
result = dns_rdataset_next(rdataset);
}
dns_rdata_reset(&rdata);
} while (result == ISC_R_SUCCESS);
if (result != ISC_R_NOMORE) {
return (result);
}
return (ISC_R_SUCCESS);
}
isc_result_t
dns_rdataset_addnoqname(dns_rdataset_t *rdataset, dns_name_t *name) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->addnoqname == NULL) {
return (ISC_R_NOTIMPLEMENTED);
}
return ((rdataset->methods->addnoqname)(rdataset, name));
}
isc_result_t
dns_rdataset_getnoqname(dns_rdataset_t *rdataset, dns_name_t *name,
dns_rdataset_t *neg, dns_rdataset_t *negsig) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->getnoqname == NULL) {
return (ISC_R_NOTIMPLEMENTED);
}
return ((rdataset->methods->getnoqname)(rdataset, name, neg, negsig));
}
isc_result_t
dns_rdataset_addclosest(dns_rdataset_t *rdataset, const dns_name_t *name) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->addclosest == NULL) {
return (ISC_R_NOTIMPLEMENTED);
}
return ((rdataset->methods->addclosest)(rdataset, name));
}
isc_result_t
dns_rdataset_getclosest(dns_rdataset_t *rdataset, dns_name_t *name,
dns_rdataset_t *neg, dns_rdataset_t *negsig) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->getclosest == NULL) {
return (ISC_R_NOTIMPLEMENTED);
}
return ((rdataset->methods->getclosest)(rdataset, name, neg, negsig));
}
void
dns_rdataset_settrust(dns_rdataset_t *rdataset, dns_trust_t trust) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->settrust != NULL) {
(rdataset->methods->settrust)(rdataset, trust);
} else {
rdataset->trust = trust;
}
}
void
dns_rdataset_expire(dns_rdataset_t *rdataset) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->expire != NULL) {
(rdataset->methods->expire)(rdataset);
}
}
void
dns_rdataset_clearprefetch(dns_rdataset_t *rdataset) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->clearprefetch != NULL) {
(rdataset->methods->clearprefetch)(rdataset);
}
}
void
dns_rdataset_setownercase(dns_rdataset_t *rdataset, const dns_name_t *name) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->setownercase != NULL) {
(rdataset->methods->setownercase)(rdataset, name);
}
}
void
dns_rdataset_getownercase(const dns_rdataset_t *rdataset, dns_name_t *name) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
if (rdataset->methods->getownercase != NULL) {
(rdataset->methods->getownercase)(rdataset, name);
}
}
void
dns_rdataset_trimttl(dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
dns_rdata_rrsig_t *rrsig, isc_stdtime_t now,
bool acceptexpired) {
uint32_t ttl = 0;
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(DNS_RDATASET_VALID(sigrdataset));
REQUIRE(rrsig != NULL);
/*
* If we accept expired RRsets keep them for no more than 120 seconds.
*/
if (acceptexpired &&
(isc_serial_le(rrsig->timeexpire, ((now + 120) & 0xffffffff)) ||
isc_serial_le(rrsig->timeexpire, now)))
{
ttl = 120;
} else if (isc_serial_ge(rrsig->timeexpire, now)) {
ttl = rrsig->timeexpire - now;
}
ttl = ISC_MIN(ISC_MIN(rdataset->ttl, sigrdataset->ttl),
ISC_MIN(rrsig->originalttl, ttl));
rdataset->ttl = ttl;
sigrdataset->ttl = ttl;
}
isc_result_t
dns_rdataset_addglue(dns_rdataset_t *rdataset, dns_dbversion_t *version,
dns_message_t *msg) {
REQUIRE(DNS_RDATASET_VALID(rdataset));
REQUIRE(rdataset->methods != NULL);
REQUIRE(rdataset->type == dns_rdatatype_ns);
if (rdataset->methods->addglue == NULL) {
return (ISC_R_NOTIMPLEMENTED);
}
return ((rdataset->methods->addglue)(rdataset, version, msg));
}