xref: /netbsd-src/external/mpl/bind/dist/lib/dns/rootns.c (revision f8cf1a9151c7af1cb0bd8b09c13c66bca599c027)
1 /*	$NetBSD: rootns.c,v 1.8 2024/02/21 22:52:08 christos Exp $	*/
2 
3 /*
4  * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
5  *
6  * SPDX-License-Identifier: MPL-2.0
7  *
8  * This Source Code Form is subject to the terms of the Mozilla Public
9  * License, v. 2.0. If a copy of the MPL was not distributed with this
10  * file, you can obtain one at https://mozilla.org/MPL/2.0/.
11  *
12  * See the COPYRIGHT file distributed with this work for additional
13  * information regarding copyright ownership.
14  */
15 
16 /*! \file */
17 
18 #include <stdbool.h>
19 
20 #include <isc/buffer.h>
21 #include <isc/result.h>
22 #include <isc/string.h> /* Required for HP/UX (and others?) */
23 #include <isc/util.h>
24 
25 #include <dns/callbacks.h>
26 #include <dns/db.h>
27 #include <dns/dbiterator.h>
28 #include <dns/fixedname.h>
29 #include <dns/log.h>
30 #include <dns/master.h>
31 #include <dns/rdata.h>
32 #include <dns/rdataset.h>
33 #include <dns/rdatasetiter.h>
34 #include <dns/rdatastruct.h>
35 #include <dns/rdatatype.h>
36 #include <dns/rootns.h>
37 #include <dns/view.h>
38 
39 /*
40  * Also update 'upcoming' when updating 'root_ns'.
41  */
42 static char root_ns[] =
43 	";\n"
44 	"; Internet Root Nameservers\n"
45 	";\n"
46 	"$TTL 518400\n"
47 	".                       518400  IN      NS      A.ROOT-SERVERS.NET.\n"
48 	".                       518400  IN      NS      B.ROOT-SERVERS.NET.\n"
49 	".                       518400  IN      NS      C.ROOT-SERVERS.NET.\n"
50 	".                       518400  IN      NS      D.ROOT-SERVERS.NET.\n"
51 	".                       518400  IN      NS      E.ROOT-SERVERS.NET.\n"
52 	".                       518400  IN      NS      F.ROOT-SERVERS.NET.\n"
53 	".                       518400  IN      NS      G.ROOT-SERVERS.NET.\n"
54 	".                       518400  IN      NS      H.ROOT-SERVERS.NET.\n"
55 	".                       518400  IN      NS      I.ROOT-SERVERS.NET.\n"
56 	".                       518400  IN      NS      J.ROOT-SERVERS.NET.\n"
57 	".                       518400  IN      NS      K.ROOT-SERVERS.NET.\n"
58 	".                       518400  IN      NS      L.ROOT-SERVERS.NET.\n"
59 	".                       518400  IN      NS      M.ROOT-SERVERS.NET.\n"
60 	"A.ROOT-SERVERS.NET.     3600000 IN      A       198.41.0.4\n"
61 	"A.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:503:BA3E::2:30\n"
62 	"B.ROOT-SERVERS.NET.     3600000 IN      A       170.247.170.2\n"
63 	"B.ROOT-SERVERS.NET.     3600000 IN      AAAA    2801:1b8:10::b\n"
64 	"C.ROOT-SERVERS.NET.     3600000 IN      A       192.33.4.12\n"
65 	"C.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:2::c\n"
66 	"D.ROOT-SERVERS.NET.     3600000 IN      A       199.7.91.13\n"
67 	"D.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:2d::d\n"
68 	"E.ROOT-SERVERS.NET.     3600000 IN      A       192.203.230.10\n"
69 	"E.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:a8::e\n"
70 	"F.ROOT-SERVERS.NET.     3600000 IN      A       192.5.5.241\n"
71 	"F.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:2F::F\n"
72 	"G.ROOT-SERVERS.NET.     3600000 IN      A       192.112.36.4\n"
73 	"G.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:12::d0d\n"
74 	"H.ROOT-SERVERS.NET.     3600000 IN      A       198.97.190.53\n"
75 	"H.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:1::53\n"
76 	"I.ROOT-SERVERS.NET.     3600000 IN      A       192.36.148.17\n"
77 	"I.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:7fe::53\n"
78 	"J.ROOT-SERVERS.NET.     3600000 IN      A       192.58.128.30\n"
79 	"J.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:503:C27::2:30\n"
80 	"K.ROOT-SERVERS.NET.     3600000 IN      A       193.0.14.129\n"
81 	"K.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:7FD::1\n"
82 	"L.ROOT-SERVERS.NET.     3600000 IN      A       199.7.83.42\n"
83 	"L.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:500:9f::42\n"
84 	"M.ROOT-SERVERS.NET.     3600000 IN      A       202.12.27.33\n"
85 	"M.ROOT-SERVERS.NET.     3600000 IN      AAAA    2001:DC3::35\n";
86 
87 static unsigned char b_data[] = "\001b\014root-servers\003net";
88 static unsigned char b_offsets[] = { 0, 2, 15, 19 };
89 
90 static struct upcoming {
91 	const dns_name_t name;
92 	dns_rdatatype_t type;
93 	isc_stdtime_t time;
94 } upcoming[] = { {
95 			 .name = DNS_NAME_INITABSOLUTE(b_data, b_offsets),
96 			 .type = dns_rdatatype_a,
97 			 .time = 1701086400 /* November 27 2023, 12:00 UTC */
98 		 },
99 		 {
100 			 .name = DNS_NAME_INITABSOLUTE(b_data, b_offsets),
101 			 .type = dns_rdatatype_aaaa,
102 			 .time = 1701086400 /* November 27 2023, 12:00 UTC */
103 		 } };
104 
105 static isc_result_t
106 in_rootns(dns_rdataset_t *rootns, dns_name_t *name) {
107 	isc_result_t result;
108 	dns_rdata_t rdata = DNS_RDATA_INIT;
109 	dns_rdata_ns_t ns;
110 
111 	if (!dns_rdataset_isassociated(rootns)) {
112 		return (ISC_R_NOTFOUND);
113 	}
114 
115 	result = dns_rdataset_first(rootns);
116 	while (result == ISC_R_SUCCESS) {
117 		dns_rdataset_current(rootns, &rdata);
118 		result = dns_rdata_tostruct(&rdata, &ns, NULL);
119 		if (result != ISC_R_SUCCESS) {
120 			return (result);
121 		}
122 		if (dns_name_compare(name, &ns.name) == 0) {
123 			return (ISC_R_SUCCESS);
124 		}
125 		result = dns_rdataset_next(rootns);
126 		dns_rdata_reset(&rdata);
127 	}
128 	if (result == ISC_R_NOMORE) {
129 		result = ISC_R_NOTFOUND;
130 	}
131 	return (result);
132 }
133 
134 static isc_result_t
135 check_node(dns_rdataset_t *rootns, dns_name_t *name,
136 	   dns_rdatasetiter_t *rdsiter) {
137 	isc_result_t result;
138 	dns_rdataset_t rdataset;
139 
140 	dns_rdataset_init(&rdataset);
141 	result = dns_rdatasetiter_first(rdsiter);
142 	while (result == ISC_R_SUCCESS) {
143 		dns_rdatasetiter_current(rdsiter, &rdataset);
144 		switch (rdataset.type) {
145 		case dns_rdatatype_a:
146 		case dns_rdatatype_aaaa:
147 			result = in_rootns(rootns, name);
148 			if (result != ISC_R_SUCCESS) {
149 				goto cleanup;
150 			}
151 			break;
152 		case dns_rdatatype_ns:
153 			if (dns_name_compare(name, dns_rootname) == 0) {
154 				break;
155 			}
156 			FALLTHROUGH;
157 		default:
158 			result = ISC_R_FAILURE;
159 			goto cleanup;
160 		}
161 		dns_rdataset_disassociate(&rdataset);
162 		result = dns_rdatasetiter_next(rdsiter);
163 	}
164 	if (result == ISC_R_NOMORE) {
165 		result = ISC_R_SUCCESS;
166 	}
167 cleanup:
168 	if (dns_rdataset_isassociated(&rdataset)) {
169 		dns_rdataset_disassociate(&rdataset);
170 	}
171 	return (result);
172 }
173 
174 static isc_result_t
175 check_hints(dns_db_t *db) {
176 	isc_result_t result;
177 	dns_rdataset_t rootns;
178 	dns_dbiterator_t *dbiter = NULL;
179 	dns_dbnode_t *node = NULL;
180 	isc_stdtime_t now;
181 	dns_fixedname_t fixname;
182 	dns_name_t *name;
183 	dns_rdatasetiter_t *rdsiter = NULL;
184 
185 	isc_stdtime_get(&now);
186 
187 	name = dns_fixedname_initname(&fixname);
188 
189 	dns_rdataset_init(&rootns);
190 	(void)dns_db_find(db, dns_rootname, NULL, dns_rdatatype_ns, 0, now,
191 			  NULL, name, &rootns, NULL);
192 	result = dns_db_createiterator(db, 0, &dbiter);
193 	if (result != ISC_R_SUCCESS) {
194 		goto cleanup;
195 	}
196 	result = dns_dbiterator_first(dbiter);
197 	while (result == ISC_R_SUCCESS) {
198 		result = dns_dbiterator_current(dbiter, &node, name);
199 		if (result != ISC_R_SUCCESS) {
200 			goto cleanup;
201 		}
202 		result = dns_db_allrdatasets(db, node, NULL, 0, now, &rdsiter);
203 		if (result != ISC_R_SUCCESS) {
204 			goto cleanup;
205 		}
206 		result = check_node(&rootns, name, rdsiter);
207 		if (result != ISC_R_SUCCESS) {
208 			goto cleanup;
209 		}
210 		dns_rdatasetiter_destroy(&rdsiter);
211 		dns_db_detachnode(db, &node);
212 		result = dns_dbiterator_next(dbiter);
213 	}
214 	if (result == ISC_R_NOMORE) {
215 		result = ISC_R_SUCCESS;
216 	}
217 
218 cleanup:
219 	if (dns_rdataset_isassociated(&rootns)) {
220 		dns_rdataset_disassociate(&rootns);
221 	}
222 	if (rdsiter != NULL) {
223 		dns_rdatasetiter_destroy(&rdsiter);
224 	}
225 	if (node != NULL) {
226 		dns_db_detachnode(db, &node);
227 	}
228 	if (dbiter != NULL) {
229 		dns_dbiterator_destroy(&dbiter);
230 	}
231 	return (result);
232 }
233 
234 isc_result_t
235 dns_rootns_create(isc_mem_t *mctx, dns_rdataclass_t rdclass,
236 		  const char *filename, dns_db_t **target) {
237 	isc_result_t result, eresult;
238 	isc_buffer_t source;
239 	unsigned int len;
240 	dns_rdatacallbacks_t callbacks;
241 	dns_db_t *db = NULL;
242 
243 	REQUIRE(target != NULL && *target == NULL);
244 
245 	result = dns_db_create(mctx, "rbt", dns_rootname, dns_dbtype_zone,
246 			       rdclass, 0, NULL, &db);
247 	if (result != ISC_R_SUCCESS) {
248 		goto failure;
249 	}
250 
251 	len = strlen(root_ns);
252 	isc_buffer_init(&source, root_ns, len);
253 	isc_buffer_add(&source, len);
254 
255 	dns_rdatacallbacks_init(&callbacks);
256 	result = dns_db_beginload(db, &callbacks);
257 	if (result != ISC_R_SUCCESS) {
258 		goto failure;
259 	}
260 	if (filename != NULL) {
261 		/*
262 		 * Load the hints from the specified filename.
263 		 */
264 		result = dns_master_loadfile(filename, &db->origin, &db->origin,
265 					     db->rdclass, DNS_MASTER_HINT, 0,
266 					     &callbacks, NULL, NULL, db->mctx,
267 					     dns_masterformat_text, 0);
268 	} else if (rdclass == dns_rdataclass_in) {
269 		/*
270 		 * Default to using the Internet root servers.
271 		 */
272 		result = dns_master_loadbuffer(
273 			&source, &db->origin, &db->origin, db->rdclass,
274 			DNS_MASTER_HINT, &callbacks, db->mctx);
275 	} else {
276 		result = ISC_R_NOTFOUND;
277 	}
278 	eresult = dns_db_endload(db, &callbacks);
279 	if (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE) {
280 		result = eresult;
281 	}
282 	if (result != ISC_R_SUCCESS && result != DNS_R_SEENINCLUDE) {
283 		goto failure;
284 	}
285 	if (check_hints(db) != ISC_R_SUCCESS) {
286 		isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
287 			      DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
288 			      "extra data in root hints '%s'",
289 			      (filename != NULL) ? filename : "<BUILT-IN>");
290 	}
291 	*target = db;
292 	return (ISC_R_SUCCESS);
293 
294 failure:
295 	isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_HINTS,
296 		      ISC_LOG_ERROR,
297 		      "could not configure root hints from "
298 		      "'%s': %s",
299 		      (filename != NULL) ? filename : "<BUILT-IN>",
300 		      isc_result_totext(result));
301 
302 	if (db != NULL) {
303 		dns_db_detach(&db);
304 	}
305 
306 	return (result);
307 }
308 
309 static void
310 report(dns_view_t *view, dns_name_t *name, bool missing, dns_rdata_t *rdata) {
311 	const char *viewname = "", *sep = "";
312 	char namebuf[DNS_NAME_FORMATSIZE];
313 	char typebuf[DNS_RDATATYPE_FORMATSIZE];
314 	char databuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:123.123.123.123")];
315 	isc_buffer_t buffer;
316 	isc_result_t result;
317 
318 	if (strcmp(view->name, "_bind") != 0 &&
319 	    strcmp(view->name, "_default") != 0)
320 	{
321 		viewname = view->name;
322 		sep = ": view ";
323 	}
324 
325 	dns_name_format(name, namebuf, sizeof(namebuf));
326 	dns_rdatatype_format(rdata->type, typebuf, sizeof(typebuf));
327 	isc_buffer_init(&buffer, databuf, sizeof(databuf) - 1);
328 	result = dns_rdata_totext(rdata, NULL, &buffer);
329 	RUNTIME_CHECK(result == ISC_R_SUCCESS);
330 	databuf[isc_buffer_usedlength(&buffer)] = '\0';
331 
332 	if (missing) {
333 		isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
334 			      DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
335 			      "checkhints%s%s: %s/%s (%s) missing from hints",
336 			      sep, viewname, namebuf, typebuf, databuf);
337 	} else {
338 		isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
339 			      DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
340 			      "checkhints%s%s: %s/%s (%s) extra record "
341 			      "in hints",
342 			      sep, viewname, namebuf, typebuf, databuf);
343 	}
344 }
345 
346 static bool
347 inrrset(dns_rdataset_t *rrset, dns_rdata_t *rdata) {
348 	isc_result_t result;
349 	dns_rdata_t current = DNS_RDATA_INIT;
350 
351 	result = dns_rdataset_first(rrset);
352 	while (result == ISC_R_SUCCESS) {
353 		dns_rdataset_current(rrset, &current);
354 		if (dns_rdata_compare(rdata, &current) == 0) {
355 			return (true);
356 		}
357 		dns_rdata_reset(&current);
358 		result = dns_rdataset_next(rrset);
359 	}
360 	return (false);
361 }
362 
363 static bool
364 changing(const dns_name_t *name, dns_rdatatype_t type, isc_stdtime_t now) {
365 	for (size_t i = 0; i < ARRAY_SIZE(upcoming); i++) {
366 		if (upcoming[i].time > now && upcoming[i].type == type &&
367 		    dns_name_equal(&upcoming[i].name, name))
368 		{
369 			return (true);
370 		}
371 	}
372 	return (false);
373 }
374 
375 /*
376  * Check that the address RRsets match.
377  *
378  * Note we don't complain about missing glue records.
379  */
380 
381 static void
382 check_address_records(dns_view_t *view, dns_db_t *hints, dns_db_t *db,
383 		      dns_name_t *name, isc_stdtime_t now) {
384 	isc_result_t hresult, rresult, result;
385 	dns_rdataset_t hintrrset, rootrrset;
386 	dns_rdata_t rdata = DNS_RDATA_INIT;
387 	dns_name_t *foundname;
388 	dns_fixedname_t fixed;
389 
390 	dns_rdataset_init(&hintrrset);
391 	dns_rdataset_init(&rootrrset);
392 	foundname = dns_fixedname_initname(&fixed);
393 
394 	hresult = dns_db_find(hints, name, NULL, dns_rdatatype_a, 0, now, NULL,
395 			      foundname, &hintrrset, NULL);
396 	rresult = dns_db_find(db, name, NULL, dns_rdatatype_a,
397 			      DNS_DBFIND_GLUEOK, now, NULL, foundname,
398 			      &rootrrset, NULL);
399 	if (hresult == ISC_R_SUCCESS &&
400 	    (rresult == ISC_R_SUCCESS || rresult == DNS_R_GLUE))
401 	{
402 		result = dns_rdataset_first(&rootrrset);
403 		while (result == ISC_R_SUCCESS) {
404 			dns_rdata_reset(&rdata);
405 			dns_rdataset_current(&rootrrset, &rdata);
406 			if (!inrrset(&hintrrset, &rdata) &&
407 			    !changing(name, dns_rdatatype_a, now))
408 			{
409 				report(view, name, true, &rdata);
410 			}
411 			result = dns_rdataset_next(&rootrrset);
412 		}
413 		result = dns_rdataset_first(&hintrrset);
414 		while (result == ISC_R_SUCCESS) {
415 			dns_rdata_reset(&rdata);
416 			dns_rdataset_current(&hintrrset, &rdata);
417 			if (!inrrset(&rootrrset, &rdata) &&
418 			    !changing(name, dns_rdatatype_a, now))
419 			{
420 				report(view, name, false, &rdata);
421 			}
422 			result = dns_rdataset_next(&hintrrset);
423 		}
424 	}
425 	if (hresult == ISC_R_NOTFOUND &&
426 	    (rresult == ISC_R_SUCCESS || rresult == DNS_R_GLUE))
427 	{
428 		result = dns_rdataset_first(&rootrrset);
429 		while (result == ISC_R_SUCCESS) {
430 			dns_rdata_reset(&rdata);
431 			dns_rdataset_current(&rootrrset, &rdata);
432 			report(view, name, true, &rdata);
433 			result = dns_rdataset_next(&rootrrset);
434 		}
435 	}
436 	if (dns_rdataset_isassociated(&rootrrset)) {
437 		dns_rdataset_disassociate(&rootrrset);
438 	}
439 	if (dns_rdataset_isassociated(&hintrrset)) {
440 		dns_rdataset_disassociate(&hintrrset);
441 	}
442 
443 	/*
444 	 * Check AAAA records.
445 	 */
446 	hresult = dns_db_find(hints, name, NULL, dns_rdatatype_aaaa, 0, now,
447 			      NULL, foundname, &hintrrset, NULL);
448 	rresult = dns_db_find(db, name, NULL, dns_rdatatype_aaaa,
449 			      DNS_DBFIND_GLUEOK, now, NULL, foundname,
450 			      &rootrrset, NULL);
451 	if (hresult == ISC_R_SUCCESS &&
452 	    (rresult == ISC_R_SUCCESS || rresult == DNS_R_GLUE))
453 	{
454 		result = dns_rdataset_first(&rootrrset);
455 		while (result == ISC_R_SUCCESS) {
456 			dns_rdata_reset(&rdata);
457 			dns_rdataset_current(&rootrrset, &rdata);
458 			if (!inrrset(&hintrrset, &rdata) &&
459 			    !changing(name, dns_rdatatype_aaaa, now))
460 			{
461 				report(view, name, true, &rdata);
462 			}
463 			dns_rdata_reset(&rdata);
464 			result = dns_rdataset_next(&rootrrset);
465 		}
466 		result = dns_rdataset_first(&hintrrset);
467 		while (result == ISC_R_SUCCESS) {
468 			dns_rdata_reset(&rdata);
469 			dns_rdataset_current(&hintrrset, &rdata);
470 			if (!inrrset(&rootrrset, &rdata) &&
471 			    !changing(name, dns_rdatatype_aaaa, now))
472 			{
473 				report(view, name, false, &rdata);
474 			}
475 			dns_rdata_reset(&rdata);
476 			result = dns_rdataset_next(&hintrrset);
477 		}
478 	}
479 	if (hresult == ISC_R_NOTFOUND &&
480 	    (rresult == ISC_R_SUCCESS || rresult == DNS_R_GLUE))
481 	{
482 		result = dns_rdataset_first(&rootrrset);
483 		while (result == ISC_R_SUCCESS) {
484 			dns_rdata_reset(&rdata);
485 			dns_rdataset_current(&rootrrset, &rdata);
486 			report(view, name, true, &rdata);
487 			dns_rdata_reset(&rdata);
488 			result = dns_rdataset_next(&rootrrset);
489 		}
490 	}
491 	if (dns_rdataset_isassociated(&rootrrset)) {
492 		dns_rdataset_disassociate(&rootrrset);
493 	}
494 	if (dns_rdataset_isassociated(&hintrrset)) {
495 		dns_rdataset_disassociate(&hintrrset);
496 	}
497 }
498 
499 void
500 dns_root_checkhints(dns_view_t *view, dns_db_t *hints, dns_db_t *db) {
501 	isc_result_t result;
502 	dns_rdata_t rdata = DNS_RDATA_INIT;
503 	dns_rdata_ns_t ns;
504 	dns_rdataset_t hintns, rootns;
505 	const char *viewname = "", *sep = "";
506 	isc_stdtime_t now;
507 	dns_name_t *name;
508 	dns_fixedname_t fixed;
509 
510 	REQUIRE(hints != NULL);
511 	REQUIRE(db != NULL);
512 	REQUIRE(view != NULL);
513 
514 	isc_stdtime_get(&now);
515 
516 	if (strcmp(view->name, "_bind") != 0 &&
517 	    strcmp(view->name, "_default") != 0)
518 	{
519 		viewname = view->name;
520 		sep = ": view ";
521 	}
522 
523 	dns_rdataset_init(&hintns);
524 	dns_rdataset_init(&rootns);
525 	name = dns_fixedname_initname(&fixed);
526 
527 	result = dns_db_find(hints, dns_rootname, NULL, dns_rdatatype_ns, 0,
528 			     now, NULL, name, &hintns, NULL);
529 	if (result != ISC_R_SUCCESS) {
530 		isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
531 			      DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
532 			      "checkhints%s%s: unable to get root NS rrset "
533 			      "from hints: %s",
534 			      sep, viewname, isc_result_totext(result));
535 		goto cleanup;
536 	}
537 
538 	result = dns_db_find(db, dns_rootname, NULL, dns_rdatatype_ns, 0, now,
539 			     NULL, name, &rootns, NULL);
540 	if (result != ISC_R_SUCCESS) {
541 		isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
542 			      DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
543 			      "checkhints%s%s: unable to get root NS rrset "
544 			      "from cache: %s",
545 			      sep, viewname, isc_result_totext(result));
546 		goto cleanup;
547 	}
548 
549 	/*
550 	 * Look for missing root NS names.
551 	 */
552 	result = dns_rdataset_first(&rootns);
553 	while (result == ISC_R_SUCCESS) {
554 		dns_rdataset_current(&rootns, &rdata);
555 		result = dns_rdata_tostruct(&rdata, &ns, NULL);
556 		RUNTIME_CHECK(result == ISC_R_SUCCESS);
557 		result = in_rootns(&hintns, &ns.name);
558 		if (result != ISC_R_SUCCESS) {
559 			char namebuf[DNS_NAME_FORMATSIZE];
560 			/* missing from hints */
561 			dns_name_format(&ns.name, namebuf, sizeof(namebuf));
562 			isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
563 				      DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
564 				      "checkhints%s%s: unable to find root "
565 				      "NS '%s' in hints",
566 				      sep, viewname, namebuf);
567 		} else {
568 			check_address_records(view, hints, db, &ns.name, now);
569 		}
570 		dns_rdata_reset(&rdata);
571 		result = dns_rdataset_next(&rootns);
572 	}
573 	if (result != ISC_R_NOMORE) {
574 		goto cleanup;
575 	}
576 
577 	/*
578 	 * Look for extra root NS names.
579 	 */
580 	result = dns_rdataset_first(&hintns);
581 	while (result == ISC_R_SUCCESS) {
582 		dns_rdataset_current(&hintns, &rdata);
583 		result = dns_rdata_tostruct(&rdata, &ns, NULL);
584 		RUNTIME_CHECK(result == ISC_R_SUCCESS);
585 		result = in_rootns(&rootns, &ns.name);
586 		if (result != ISC_R_SUCCESS) {
587 			char namebuf[DNS_NAME_FORMATSIZE];
588 			/* extra entry in hints */
589 			dns_name_format(&ns.name, namebuf, sizeof(namebuf));
590 			isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL,
591 				      DNS_LOGMODULE_HINTS, ISC_LOG_WARNING,
592 				      "checkhints%s%s: extra NS '%s' in hints",
593 				      sep, viewname, namebuf);
594 		}
595 		dns_rdata_reset(&rdata);
596 		result = dns_rdataset_next(&hintns);
597 	}
598 	if (result != ISC_R_NOMORE) {
599 		goto cleanup;
600 	}
601 
602 cleanup:
603 	if (dns_rdataset_isassociated(&rootns)) {
604 		dns_rdataset_disassociate(&rootns);
605 	}
606 	if (dns_rdataset_isassociated(&hintns)) {
607 		dns_rdataset_disassociate(&hintns);
608 	}
609 }
610