/* $NetBSD: rootns.c,v 1.7 2023/01/25 21:43:30 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 <stdbool.h>
#include <isc/buffer.h>
#include <isc/string.h> /* Required for HP/UX (and others?) */
#include <isc/util.h>
#include <dns/callbacks.h>
#include <dns/db.h>
#include <dns/dbiterator.h>
#include <dns/fixedname.h>
#include <dns/log.h>
#include <dns/master.h>
#include <dns/rdata.h>
#include <dns/rdataset.h>
#include <dns/rdatasetiter.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/result.h>
#include <dns/rootns.h>
#include <dns/view.h>
static char root_ns[] =
";\n"
"; Internet Root Nameservers\n"
";\n"
"$TTL 518400\n"
". 518400 IN NS A.ROOT-SERVERS.NET.\n"
". 518400 IN NS B.ROOT-SERVERS.NET.\n"
". 518400 IN NS C.ROOT-SERVERS.NET.\n"
". 518400 IN NS D.ROOT-SERVERS.NET.\n"
". 518400 IN NS E.ROOT-SERVERS.NET.\n"
". 518400 IN NS F.ROOT-SERVERS.NET.\n"
". 518400 IN NS G.ROOT-SERVERS.NET.\n"
". 518400 IN NS H.ROOT-SERVERS.NET.\n"
". 518400 IN NS I.ROOT-SERVERS.NET.\n"
". 518400 IN NS J.ROOT-SERVERS.NET.\n"
". 518400 IN NS K.ROOT-SERVERS.NET.\n"
". 518400 IN NS L.ROOT-SERVERS.NET.\n"
". 518400 IN NS M.ROOT-SERVERS.NET.\n"
"A.ROOT-SERVERS.NET. 3600000 IN A 198.41.0.4\n"
"A.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:503:BA3E::2:30\n"
"B.ROOT-SERVERS.NET. 3600000 IN A 199.9.14.201\n"
"B.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:200::b\n"
"C.ROOT-SERVERS.NET. 3600000 IN A 192.33.4.12\n"
"C.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:2::c\n"
"D.ROOT-SERVERS.NET. 3600000 IN A 199.7.91.13\n"
"D.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:2d::d\n"
"E.ROOT-SERVERS.NET. 3600000 IN A 192.203.230.10\n"
"E.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:a8::e\n"
"F.ROOT-SERVERS.NET. 3600000 IN A 192.5.5.241\n"
"F.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:2F::F\n"
"G.ROOT-SERVERS.NET. 3600000 IN A 192.112.36.4\n"
"G.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:12::d0d\n"
"H.ROOT-SERVERS.NET. 3600000 IN A 198.97.190.53\n"
"H.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:1::53\n"
"I.ROOT-SERVERS.NET. 3600000 IN A 192.36.148.17\n"
"I.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:7fe::53\n"
"J.ROOT-SERVERS.NET. 3600000 IN A 192.58.128.30\n"
"J.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:503:C27::2:30\n"
"K.ROOT-SERVERS.NET. 3600000 IN A 193.0.14.129\n"
"K.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:7FD::1\n"
"L.ROOT-SERVERS.NET. 3600000 IN A 199.7.83.42\n"
"L.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:500:9f::42\n"
"M.ROOT-SERVERS.NET. 3600000 IN A 202.12.27.33\n"
"M.ROOT-SERVERS.NET. 3600000 IN AAAA 2001:DC3::35\n";
static isc_result_t
in_rootns(dns_rdataset_t *rootns, dns_name_t *name) {
isc_result_t result;
dns_rdata_t rdata = DNS_RDATA_INIT;
dns_rdata_ns_t ns;
if (!dns_rdataset_isassociated(rootns)) {
return (ISC_R_NOTFOUND);
}
result = dns_rdataset_first(rootns);
while (result == ISC_R_SUCCESS) {
dns_rdataset_current(rootns, &rdata);
result = dns_rdata_tostruct(&rdata, &ns, NULL);
if (result != ISC_R_SUCCESS) {
return (result);
}
if (dns_name_compare(name, &ns.name) == 0) {
return (ISC_R_SUCCESS);
}
result = dns_rdataset_next(rootns);
dns_rdata_reset(&rdata);
}
if (result == ISC_R_NOMORE) {
result = ISC_R_NOTFOUND;
}
return (result);
}
static isc_result_t
check_node(dns_rdataset_t *rootns, dns_name_t *name,
dns_rdatasetiter_t *rdsiter) {
isc_result_t result;
dns_rdataset_t rdataset;
dns_rdataset_init(&rdataset);
result = dns_rdatasetiter_first(rdsiter);
while (result == ISC_R_SUCCESS) {
dns_rdatasetiter_current(rdsiter, &rdataset);
switch (rdataset.type) {
case dns_rdatatype_a:
case dns_rdatatype_aaaa:
result = in_rootns(rootns, name);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
break;
case dns_rdatatype_ns:
if (dns_name_compare(name, dns_rootname) == 0) {
break;
}
FALLTHROUGH;
default:
result = ISC_R_FAILURE;
goto cleanup;
}
dns_rdataset_disassociate(&rdataset);
result = dns_rdatasetiter_next(rdsiter);
}
if (result == ISC_R_NOMORE) {
result = ISC_R_SUCCESS;
}
cleanup:
if (dns_rdataset_isassociated(&rdataset)) {
dns_rdataset_disassociate(&rdataset);
}
return (result);
}
static isc_result_t
check_hints(dns_db_t *db) {
isc_result_t result;
dns_rdataset_t rootns;
dns_dbiterator_t *dbiter = NULL;
dns_dbnode_t *node = NULL;
isc_stdtime_t now;
dns_fixedname_t fixname;
dns_name_t *name;
dns_rdatasetiter_t *rdsiter = NULL;
isc_stdtime_get(&now);
name = dns_fixedname_initname(&fixname);
dns_rdataset_init(&rootns);
(void)dns_db_find(db, dns_rootname, NULL, dns_rdatatype_ns, 0, now,
NULL, name, &rootns, NULL);
result = dns_db_createiterator(db, 0, &dbiter);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
result = dns_dbiterator_first(dbiter);
while (result == ISC_R_SUCCESS) {
result = dns_dbiterator_current(dbiter, &node, name);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
result = dns_db_allrdatasets(db, node, NULL, 0, now, &rdsiter);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
result = check_node(&rootns, name, rdsiter);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
dns_rdatasetiter_destroy(&rdsiter);
dns_db_detachnode(db, &node);
result = dns_dbiterator_next(dbiter);
}
if (result == ISC_R_NOMORE) {
result = ISC_R_SUCCESS;
}
cleanup:
if (dns_rdataset_isassociated(&rootns)) {
dns_rdataset_disassociate(&rootns);
}
if (rdsiter != NULL) {
dns_rdatasetiter_destroy(&rdsiter);
}
if (node != NULL) {
dns_db_detachnode(db, &node);
}
if (dbiter != NULL) {
dns_dbiterator_destroy(&dbiter);
}
return (result);
}
isc_result_t
dns_rootns_create(isc_mem_t *mctx, dns_rdataclass_t rdclass,
const char *filename, dns_db_t **target) {
isc_result_t result, eresult;
isc_buffer_t source;
unsigned int len;
dns_rdatacallbacks_t callbacks;
dns_db_t *db = NULL;
REQUIRE(target != NULL && *target == NULL);
result = dns_db_create(mctx, "rbt", dns_rootname, dns_dbtype_zone,
rdclass, 0, NULL, &db);
if (result != ISC_R_SUCCESS) {
goto failure;
}
len = strlen(root_ns);
isc_buffer_init(&source, root_ns, len);
isc_buffer_add(&source, len);
dns_rdatacallbacks_init(&callbacks);
result = dns_db_beginload(db, &callbacks);
if (result != ISC_R_SUCCESS) {
goto failure;
}
if (filename != NULL) {
/*
* Load the hints from the specified filename.
*/
result = dns_master_loadfile(filename, &db->origin, &db->origin,
db->rdclass, DNS_MASTER_HINT, 0,
&callbacks, NULL, NULL, db->mctx,
dns_masterformat_text, 0);
} else if (rdclass == dns_rdataclass_in) {
/*
* Default to using the Internet root servers.
*/
result = dns_master_loadbuffer(
&source, &db->origin, &db->origin, db->rdclass,
DNS_MASTER_HINT, &callbacks, db->mctx);
} else {
result = ISC_R_NOTFOUND;
}
eresult = dns_db_endload(db, &callbacks);
if (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE) {
result = eresult;
}
if (result != ISC_R_SUCCESS && result != DNS_R_SEENINCLUDE) {
goto failure;
}
if (check_hints(db) != ISC_R_SUCCESS) {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
"extra data in root hints '%s'",
(filename != NULL) ? filename : "<BUILT-IN>");
}
*target = db;
return (ISC_R_SUCCESS);
failure:
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_HINTS,
ISC_LOG_ERROR,
"could not configure root hints from "
"'%s': %s",
(filename != NULL) ? filename : "<BUILT-IN>",
isc_result_totext(result));
if (db != NULL) {
dns_db_detach(&db);
}
return (result);
}
static void
report(dns_view_t *view, dns_name_t *name, bool missing, dns_rdata_t *rdata) {
const char *viewname = "", *sep = "";
char namebuf[DNS_NAME_FORMATSIZE];
char typebuf[DNS_RDATATYPE_FORMATSIZE];
char databuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:123.123.123.123")];
isc_buffer_t buffer;
isc_result_t result;
if (strcmp(view->name, "_bind") != 0 &&
strcmp(view->name, "_default") != 0)
{
viewname = view->name;
sep = ": view ";
}
dns_name_format(name, namebuf, sizeof(namebuf));
dns_rdatatype_format(rdata->type, typebuf, sizeof(typebuf));
isc_buffer_init(&buffer, databuf, sizeof(databuf) - 1);
result = dns_rdata_totext(rdata, NULL, &buffer);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
databuf[isc_buffer_usedlength(&buffer)] = '\0';
if (missing) {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
"checkhints%s%s: %s/%s (%s) missing from hints",
sep, viewname, namebuf, typebuf, databuf);
} else {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
"checkhints%s%s: %s/%s (%s) extra record "
"in hints",
sep, viewname, namebuf, typebuf, databuf);
}
}
static bool
inrrset(dns_rdataset_t *rrset, dns_rdata_t *rdata) {
isc_result_t result;
dns_rdata_t current = DNS_RDATA_INIT;
result = dns_rdataset_first(rrset);
while (result == ISC_R_SUCCESS) {
dns_rdataset_current(rrset, ¤t);
if (dns_rdata_compare(rdata, ¤t) == 0) {
return (true);
}
dns_rdata_reset(¤t);
result = dns_rdataset_next(rrset);
}
return (false);
}
/*
* Check that the address RRsets match.
*
* Note we don't complain about missing glue records.
*/
static void
check_address_records(dns_view_t *view, dns_db_t *hints, dns_db_t *db,
dns_name_t *name, isc_stdtime_t now) {
isc_result_t hresult, rresult, result;
dns_rdataset_t hintrrset, rootrrset;
dns_rdata_t rdata = DNS_RDATA_INIT;
dns_name_t *foundname;
dns_fixedname_t fixed;
dns_rdataset_init(&hintrrset);
dns_rdataset_init(&rootrrset);
foundname = dns_fixedname_initname(&fixed);
hresult = dns_db_find(hints, name, NULL, dns_rdatatype_a, 0, now, NULL,
foundname, &hintrrset, NULL);
rresult = dns_db_find(db, name, NULL, dns_rdatatype_a,
DNS_DBFIND_GLUEOK, now, NULL, foundname,
&rootrrset, NULL);
if (hresult == ISC_R_SUCCESS &&
(rresult == ISC_R_SUCCESS || rresult == DNS_R_GLUE))
{
result = dns_rdataset_first(&rootrrset);
while (result == ISC_R_SUCCESS) {
dns_rdata_reset(&rdata);
dns_rdataset_current(&rootrrset, &rdata);
if (!inrrset(&hintrrset, &rdata)) {
report(view, name, true, &rdata);
}
result = dns_rdataset_next(&rootrrset);
}
result = dns_rdataset_first(&hintrrset);
while (result == ISC_R_SUCCESS) {
dns_rdata_reset(&rdata);
dns_rdataset_current(&hintrrset, &rdata);
if (!inrrset(&rootrrset, &rdata)) {
report(view, name, false, &rdata);
}
result = dns_rdataset_next(&hintrrset);
}
}
if (hresult == ISC_R_NOTFOUND &&
(rresult == ISC_R_SUCCESS || rresult == DNS_R_GLUE))
{
result = dns_rdataset_first(&rootrrset);
while (result == ISC_R_SUCCESS) {
dns_rdata_reset(&rdata);
dns_rdataset_current(&rootrrset, &rdata);
report(view, name, true, &rdata);
result = dns_rdataset_next(&rootrrset);
}
}
if (dns_rdataset_isassociated(&rootrrset)) {
dns_rdataset_disassociate(&rootrrset);
}
if (dns_rdataset_isassociated(&hintrrset)) {
dns_rdataset_disassociate(&hintrrset);
}
/*
* Check AAAA records.
*/
hresult = dns_db_find(hints, name, NULL, dns_rdatatype_aaaa, 0, now,
NULL, foundname, &hintrrset, NULL);
rresult = dns_db_find(db, name, NULL, dns_rdatatype_aaaa,
DNS_DBFIND_GLUEOK, now, NULL, foundname,
&rootrrset, NULL);
if (hresult == ISC_R_SUCCESS &&
(rresult == ISC_R_SUCCESS || rresult == DNS_R_GLUE))
{
result = dns_rdataset_first(&rootrrset);
while (result == ISC_R_SUCCESS) {
dns_rdata_reset(&rdata);
dns_rdataset_current(&rootrrset, &rdata);
if (!inrrset(&hintrrset, &rdata)) {
report(view, name, true, &rdata);
}
dns_rdata_reset(&rdata);
result = dns_rdataset_next(&rootrrset);
}
result = dns_rdataset_first(&hintrrset);
while (result == ISC_R_SUCCESS) {
dns_rdata_reset(&rdata);
dns_rdataset_current(&hintrrset, &rdata);
if (!inrrset(&rootrrset, &rdata)) {
report(view, name, false, &rdata);
}
dns_rdata_reset(&rdata);
result = dns_rdataset_next(&hintrrset);
}
}
if (hresult == ISC_R_NOTFOUND &&
(rresult == ISC_R_SUCCESS || rresult == DNS_R_GLUE))
{
result = dns_rdataset_first(&rootrrset);
while (result == ISC_R_SUCCESS) {
dns_rdata_reset(&rdata);
dns_rdataset_current(&rootrrset, &rdata);
report(view, name, true, &rdata);
dns_rdata_reset(&rdata);
result = dns_rdataset_next(&rootrrset);
}
}
if (dns_rdataset_isassociated(&rootrrset)) {
dns_rdataset_disassociate(&rootrrset);
}
if (dns_rdataset_isassociated(&hintrrset)) {
dns_rdataset_disassociate(&hintrrset);
}
}
void
dns_root_checkhints(dns_view_t *view, dns_db_t *hints, dns_db_t *db) {
isc_result_t result;
dns_rdata_t rdata = DNS_RDATA_INIT;
dns_rdata_ns_t ns;
dns_rdataset_t hintns, rootns;
const char *viewname = "", *sep = "";
isc_stdtime_t now;
dns_name_t *name;
dns_fixedname_t fixed;
REQUIRE(hints != NULL);
REQUIRE(db != NULL);
REQUIRE(view != NULL);
isc_stdtime_get(&now);
if (strcmp(view->name, "_bind") != 0 &&
strcmp(view->name, "_default") != 0)
{
viewname = view->name;
sep = ": view ";
}
dns_rdataset_init(&hintns);
dns_rdataset_init(&rootns);
name = dns_fixedname_initname(&fixed);
result = dns_db_find(hints, dns_rootname, NULL, dns_rdatatype_ns, 0,
now, NULL, name, &hintns, NULL);
if (result != ISC_R_SUCCESS) {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
"checkhints%s%s: unable to get root NS rrset "
"from hints: %s",
sep, viewname, dns_result_totext(result));
goto cleanup;
}
result = dns_db_find(db, dns_rootname, NULL, dns_rdatatype_ns, 0, now,
NULL, name, &rootns, NULL);
if (result != ISC_R_SUCCESS) {
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
"checkhints%s%s: unable to get root NS rrset "
"from cache: %s",
sep, viewname, dns_result_totext(result));
goto cleanup;
}
/*
* Look for missing root NS names.
*/
result = dns_rdataset_first(&rootns);
while (result == ISC_R_SUCCESS) {
dns_rdataset_current(&rootns, &rdata);
result = dns_rdata_tostruct(&rdata, &ns, NULL);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
result = in_rootns(&hintns, &ns.name);
if (result != ISC_R_SUCCESS) {
char namebuf[DNS_NAME_FORMATSIZE];
/* missing from hints */
dns_name_format(&ns.name, namebuf, sizeof(namebuf));
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
"checkhints%s%s: unable to find root "
"NS '%s' in hints",
sep, viewname, namebuf);
} else {
check_address_records(view, hints, db, &ns.name, now);
}
dns_rdata_reset(&rdata);
result = dns_rdataset_next(&rootns);
}
if (result != ISC_R_NOMORE) {
goto cleanup;
}
/*
* Look for extra root NS names.
*/
result = dns_rdataset_first(&hintns);
while (result == ISC_R_SUCCESS) {
dns_rdataset_current(&hintns, &rdata);
result = dns_rdata_tostruct(&rdata, &ns, NULL);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
result = in_rootns(&rootns, &ns.name);
if (result != ISC_R_SUCCESS) {
char namebuf[DNS_NAME_FORMATSIZE];
/* extra entry in hints */
dns_name_format(&ns.name, namebuf, sizeof(namebuf));
isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
"checkhints%s%s: extra NS '%s' in hints",
sep, viewname, namebuf);
}
dns_rdata_reset(&rdata);
result = dns_rdataset_next(&hintns);
}
if (result != ISC_R_NOMORE) {
goto cleanup;
}
cleanup:
if (dns_rdataset_isassociated(&rootns)) {
dns_rdataset_disassociate(&rootns);
}
if (dns_rdataset_isassociated(&hintns)) {
dns_rdataset_disassociate(&hintns);
}
}