xref: /netbsd-src/external/mpl/bind/dist/lib/dns/db.c (revision c9055873d0546e63388f027d3d7f85381cde0545) 
1 /*	$NetBSD: db.c,v 1.10 2024/02/21 22:52:06 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 /***
19  *** Imports
20  ***/
21 
22 #include <inttypes.h>
23 #include <stdbool.h>
24 
25 #include <isc/buffer.h>
26 #include <isc/mem.h>
27 #include <isc/once.h>
28 #include <isc/result.h>
29 #include <isc/rwlock.h>
30 #include <isc/string.h>
31 #include <isc/util.h>
32 
33 #include <dns/callbacks.h>
34 #include <dns/clientinfo.h>
35 #include <dns/db.h>
36 #include <dns/dbiterator.h>
37 #include <dns/log.h>
38 #include <dns/master.h>
39 #include <dns/rdata.h>
40 #include <dns/rdataset.h>
41 #include <dns/rdatasetiter.h>
42 
43 /***
44  *** Private Types
45  ***/
46 
47 struct dns_dbimplementation {
48 	const char *name;
49 	dns_dbcreatefunc_t create;
50 	isc_mem_t *mctx;
51 	void *driverarg;
52 	ISC_LINK(dns_dbimplementation_t) link;
53 };
54 
55 /***
56  *** Supported DB Implementations Registry
57  ***/
58 
59 /*
60  * Built in database implementations are registered here.
61  */
62 
63 #include "rbtdb.h"
64 
65 unsigned int dns_pps = 0U;
66 
67 static ISC_LIST(dns_dbimplementation_t) implementations;
68 static isc_rwlock_t implock;
69 static isc_once_t once = ISC_ONCE_INIT;
70 
71 static dns_dbimplementation_t rbtimp;
72 
73 static void
74 initialize(void) {
75 	isc_rwlock_init(&implock, 0, 0);
76 
77 	rbtimp.name = "rbt";
78 	rbtimp.create = dns_rbtdb_create;
79 	rbtimp.mctx = NULL;
80 	rbtimp.driverarg = NULL;
81 	ISC_LINK_INIT(&rbtimp, link);
82 
83 	ISC_LIST_INIT(implementations);
84 	ISC_LIST_APPEND(implementations, &rbtimp, link);
85 }
86 
87 static dns_dbimplementation_t *
88 impfind(const char *name) {
89 	dns_dbimplementation_t *imp;
90 
91 	for (imp = ISC_LIST_HEAD(implementations); imp != NULL;
92 	     imp = ISC_LIST_NEXT(imp, link))
93 	{
94 		if (strcasecmp(name, imp->name) == 0) {
95 			return (imp);
96 		}
97 	}
98 	return (NULL);
99 }
100 
101 /***
102  *** Basic DB Methods
103  ***/
104 
105 isc_result_t
106 dns_db_create(isc_mem_t *mctx, const char *db_type, const dns_name_t *origin,
107 	      dns_dbtype_t type, dns_rdataclass_t rdclass, unsigned int argc,
108 	      char *argv[], dns_db_t **dbp) {
109 	dns_dbimplementation_t *impinfo;
110 
111 	RUNTIME_CHECK(isc_once_do(&once, initialize) == ISC_R_SUCCESS);
112 
113 	/*
114 	 * Create a new database using implementation 'db_type'.
115 	 */
116 
117 	REQUIRE(dbp != NULL && *dbp == NULL);
118 	REQUIRE(dns_name_isabsolute(origin));
119 
120 	RWLOCK(&implock, isc_rwlocktype_read);
121 	impinfo = impfind(db_type);
122 	if (impinfo != NULL) {
123 		isc_result_t result;
124 		result = ((impinfo->create)(mctx, origin, type, rdclass, argc,
125 					    argv, impinfo->driverarg, dbp));
126 		RWUNLOCK(&implock, isc_rwlocktype_read);
127 		return (result);
128 	}
129 
130 	RWUNLOCK(&implock, isc_rwlocktype_read);
131 
132 	isc_log_write(dns_lctx, DNS_LOGCATEGORY_DATABASE, DNS_LOGMODULE_DB,
133 		      ISC_LOG_ERROR, "unsupported database type '%s'", db_type);
134 
135 	return (ISC_R_NOTFOUND);
136 }
137 
138 void
139 dns_db_attach(dns_db_t *source, dns_db_t **targetp) {
140 	/*
141 	 * Attach *targetp to source.
142 	 */
143 
144 	REQUIRE(DNS_DB_VALID(source));
145 	REQUIRE(targetp != NULL && *targetp == NULL);
146 
147 	(source->methods->attach)(source, targetp);
148 
149 	ENSURE(*targetp == source);
150 }
151 
152 void
153 dns_db_detach(dns_db_t **dbp) {
154 	/*
155 	 * Detach *dbp from its database.
156 	 */
157 
158 	REQUIRE(dbp != NULL);
159 	REQUIRE(DNS_DB_VALID(*dbp));
160 
161 	((*dbp)->methods->detach)(dbp);
162 
163 	ENSURE(*dbp == NULL);
164 }
165 
166 bool
167 dns_db_iscache(dns_db_t *db) {
168 	/*
169 	 * Does 'db' have cache semantics?
170 	 */
171 
172 	REQUIRE(DNS_DB_VALID(db));
173 
174 	if ((db->attributes & DNS_DBATTR_CACHE) != 0) {
175 		return (true);
176 	}
177 
178 	return (false);
179 }
180 
181 bool
182 dns_db_iszone(dns_db_t *db) {
183 	/*
184 	 * Does 'db' have zone semantics?
185 	 */
186 
187 	REQUIRE(DNS_DB_VALID(db));
188 
189 	if ((db->attributes & (DNS_DBATTR_CACHE | DNS_DBATTR_STUB)) == 0) {
190 		return (true);
191 	}
192 
193 	return (false);
194 }
195 
196 bool
197 dns_db_isstub(dns_db_t *db) {
198 	/*
199 	 * Does 'db' have stub semantics?
200 	 */
201 
202 	REQUIRE(DNS_DB_VALID(db));
203 
204 	if ((db->attributes & DNS_DBATTR_STUB) != 0) {
205 		return (true);
206 	}
207 
208 	return (false);
209 }
210 
211 bool
212 dns_db_isdnssec(dns_db_t *db) {
213 	/*
214 	 * Is 'db' secure or partially secure?
215 	 */
216 
217 	REQUIRE(DNS_DB_VALID(db));
218 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
219 
220 	if (db->methods->isdnssec != NULL) {
221 		return ((db->methods->isdnssec)(db));
222 	}
223 	return ((db->methods->issecure)(db));
224 }
225 
226 bool
227 dns_db_issecure(dns_db_t *db) {
228 	/*
229 	 * Is 'db' secure?
230 	 */
231 
232 	REQUIRE(DNS_DB_VALID(db));
233 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
234 
235 	return ((db->methods->issecure)(db));
236 }
237 
238 bool
239 dns_db_ispersistent(dns_db_t *db) {
240 	/*
241 	 * Is 'db' persistent?
242 	 */
243 
244 	REQUIRE(DNS_DB_VALID(db));
245 
246 	return ((db->methods->ispersistent)(db));
247 }
248 
249 dns_name_t *
250 dns_db_origin(dns_db_t *db) {
251 	/*
252 	 * The origin of the database.
253 	 */
254 
255 	REQUIRE(DNS_DB_VALID(db));
256 
257 	return (&db->origin);
258 }
259 
260 dns_rdataclass_t
261 dns_db_class(dns_db_t *db) {
262 	/*
263 	 * The class of the database.
264 	 */
265 
266 	REQUIRE(DNS_DB_VALID(db));
267 
268 	return (db->rdclass);
269 }
270 
271 isc_result_t
272 dns_db_beginload(dns_db_t *db, dns_rdatacallbacks_t *callbacks) {
273 	/*
274 	 * Begin loading 'db'.
275 	 */
276 
277 	REQUIRE(DNS_DB_VALID(db));
278 	REQUIRE(DNS_CALLBACK_VALID(callbacks));
279 
280 	return ((db->methods->beginload)(db, callbacks));
281 }
282 
283 isc_result_t
284 dns_db_endload(dns_db_t *db, dns_rdatacallbacks_t *callbacks) {
285 	dns_dbonupdatelistener_t *listener;
286 
287 	/*
288 	 * Finish loading 'db'.
289 	 */
290 
291 	REQUIRE(DNS_DB_VALID(db));
292 	REQUIRE(DNS_CALLBACK_VALID(callbacks));
293 	REQUIRE(callbacks->add_private != NULL);
294 
295 	for (listener = ISC_LIST_HEAD(db->update_listeners); listener != NULL;
296 	     listener = ISC_LIST_NEXT(listener, link))
297 	{
298 		listener->onupdate(db, listener->onupdate_arg);
299 	}
300 
301 	return ((db->methods->endload)(db, callbacks));
302 }
303 
304 isc_result_t
305 dns_db_load(dns_db_t *db, const char *filename, dns_masterformat_t format,
306 	    unsigned int options) {
307 	isc_result_t result, eresult;
308 	dns_rdatacallbacks_t callbacks;
309 
310 	/*
311 	 * Load master file 'filename' into 'db'.
312 	 */
313 
314 	REQUIRE(DNS_DB_VALID(db));
315 
316 	if ((db->attributes & DNS_DBATTR_CACHE) != 0) {
317 		options |= DNS_MASTER_AGETTL;
318 	}
319 
320 	dns_rdatacallbacks_init(&callbacks);
321 	result = dns_db_beginload(db, &callbacks);
322 	if (result != ISC_R_SUCCESS) {
323 		return (result);
324 	}
325 	result = dns_master_loadfile(filename, &db->origin, &db->origin,
326 				     db->rdclass, options, 0, &callbacks, NULL,
327 				     NULL, db->mctx, format, 0);
328 	eresult = dns_db_endload(db, &callbacks);
329 	/*
330 	 * We always call dns_db_endload(), but we only want to return its
331 	 * result if dns_master_loadfile() succeeded.  If dns_master_loadfile()
332 	 * failed, we want to return the result code it gave us.
333 	 */
334 	if (eresult != ISC_R_SUCCESS &&
335 	    (result == ISC_R_SUCCESS || result == DNS_R_SEENINCLUDE))
336 	{
337 		result = eresult;
338 	}
339 
340 	return (result);
341 }
342 
343 isc_result_t
344 dns_db_dump(dns_db_t *db, dns_dbversion_t *version, const char *filename) {
345 	return ((db->methods->dump)(db, version, filename,
346 				    dns_masterformat_text));
347 }
348 
349 /***
350  *** Version Methods
351  ***/
352 
353 void
354 dns_db_currentversion(dns_db_t *db, dns_dbversion_t **versionp) {
355 	/*
356 	 * Open the current version for reading.
357 	 */
358 
359 	REQUIRE(DNS_DB_VALID(db));
360 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
361 	REQUIRE(versionp != NULL && *versionp == NULL);
362 
363 	(db->methods->currentversion)(db, versionp);
364 }
365 
366 isc_result_t
367 dns_db_newversion(dns_db_t *db, dns_dbversion_t **versionp) {
368 	/*
369 	 * Open a new version for reading and writing.
370 	 */
371 
372 	REQUIRE(DNS_DB_VALID(db));
373 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
374 	REQUIRE(versionp != NULL && *versionp == NULL);
375 
376 	return ((db->methods->newversion)(db, versionp));
377 }
378 
379 void
380 dns_db_attachversion(dns_db_t *db, dns_dbversion_t *source,
381 		     dns_dbversion_t **targetp) {
382 	/*
383 	 * Attach '*targetp' to 'source'.
384 	 */
385 
386 	REQUIRE(DNS_DB_VALID(db));
387 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
388 	REQUIRE(source != NULL);
389 	REQUIRE(targetp != NULL && *targetp == NULL);
390 
391 	(db->methods->attachversion)(db, source, targetp);
392 
393 	ENSURE(*targetp != NULL);
394 }
395 
396 void
397 dns_db_closeversion(dns_db_t *db, dns_dbversion_t **versionp, bool commit) {
398 	dns_dbonupdatelistener_t *listener;
399 
400 	/*
401 	 * Close version '*versionp'.
402 	 */
403 
404 	REQUIRE(DNS_DB_VALID(db));
405 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0);
406 	REQUIRE(versionp != NULL && *versionp != NULL);
407 
408 	(db->methods->closeversion)(db, versionp, commit);
409 
410 	if (commit) {
411 		for (listener = ISC_LIST_HEAD(db->update_listeners);
412 		     listener != NULL; listener = ISC_LIST_NEXT(listener, link))
413 		{
414 			listener->onupdate(db, listener->onupdate_arg);
415 		}
416 	}
417 
418 	ENSURE(*versionp == NULL);
419 }
420 
421 /***
422  *** Node Methods
423  ***/
424 
425 isc_result_t
426 dns_db_findnode(dns_db_t *db, const dns_name_t *name, bool create,
427 		dns_dbnode_t **nodep) {
428 	/*
429 	 * Find the node with name 'name'.
430 	 */
431 
432 	REQUIRE(DNS_DB_VALID(db));
433 	REQUIRE(nodep != NULL && *nodep == NULL);
434 
435 	if (db->methods->findnode != NULL) {
436 		return ((db->methods->findnode)(db, name, create, nodep));
437 	} else {
438 		return ((db->methods->findnodeext)(db, name, create, NULL, NULL,
439 						   nodep));
440 	}
441 }
442 
443 isc_result_t
444 dns_db_findnodeext(dns_db_t *db, const dns_name_t *name, bool create,
445 		   dns_clientinfomethods_t *methods,
446 		   dns_clientinfo_t *clientinfo, dns_dbnode_t **nodep) {
447 	/*
448 	 * Find the node with name 'name', passing 'arg' to the database
449 	 * implementation.
450 	 */
451 
452 	REQUIRE(DNS_DB_VALID(db));
453 	REQUIRE(nodep != NULL && *nodep == NULL);
454 
455 	if (db->methods->findnodeext != NULL) {
456 		return ((db->methods->findnodeext)(db, name, create, methods,
457 						   clientinfo, nodep));
458 	} else {
459 		return ((db->methods->findnode)(db, name, create, nodep));
460 	}
461 }
462 
463 isc_result_t
464 dns_db_findnsec3node(dns_db_t *db, const dns_name_t *name, bool create,
465 		     dns_dbnode_t **nodep) {
466 	/*
467 	 * Find the node with name 'name'.
468 	 */
469 
470 	REQUIRE(DNS_DB_VALID(db));
471 	REQUIRE(nodep != NULL && *nodep == NULL);
472 
473 	return ((db->methods->findnsec3node)(db, name, create, nodep));
474 }
475 
476 isc_result_t
477 dns_db_find(dns_db_t *db, const dns_name_t *name, dns_dbversion_t *version,
478 	    dns_rdatatype_t type, unsigned int options, isc_stdtime_t now,
479 	    dns_dbnode_t **nodep, dns_name_t *foundname,
480 	    dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) {
481 	/*
482 	 * Find the best match for 'name' and 'type' in version 'version'
483 	 * of 'db'.
484 	 */
485 
486 	REQUIRE(DNS_DB_VALID(db));
487 	REQUIRE(type != dns_rdatatype_rrsig);
488 	REQUIRE(nodep == NULL || *nodep == NULL);
489 	REQUIRE(dns_name_hasbuffer(foundname));
490 	REQUIRE(rdataset == NULL || (DNS_RDATASET_VALID(rdataset) &&
491 				     !dns_rdataset_isassociated(rdataset)));
492 	REQUIRE(sigrdataset == NULL ||
493 		(DNS_RDATASET_VALID(sigrdataset) &&
494 		 !dns_rdataset_isassociated(sigrdataset)));
495 
496 	if (db->methods->find != NULL) {
497 		return ((db->methods->find)(db, name, version, type, options,
498 					    now, nodep, foundname, rdataset,
499 					    sigrdataset));
500 	} else {
501 		return ((db->methods->findext)(db, name, version, type, options,
502 					       now, nodep, foundname, NULL,
503 					       NULL, rdataset, sigrdataset));
504 	}
505 }
506 
507 isc_result_t
508 dns_db_findext(dns_db_t *db, const dns_name_t *name, dns_dbversion_t *version,
509 	       dns_rdatatype_t type, unsigned int options, isc_stdtime_t now,
510 	       dns_dbnode_t **nodep, dns_name_t *foundname,
511 	       dns_clientinfomethods_t *methods, dns_clientinfo_t *clientinfo,
512 	       dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) {
513 	/*
514 	 * Find the best match for 'name' and 'type' in version 'version'
515 	 * of 'db', passing in 'arg'.
516 	 */
517 
518 	REQUIRE(DNS_DB_VALID(db));
519 	REQUIRE(type != dns_rdatatype_rrsig);
520 	REQUIRE(nodep == NULL || *nodep == NULL);
521 	REQUIRE(dns_name_hasbuffer(foundname));
522 	REQUIRE(rdataset == NULL || (DNS_RDATASET_VALID(rdataset) &&
523 				     !dns_rdataset_isassociated(rdataset)));
524 	REQUIRE(sigrdataset == NULL ||
525 		(DNS_RDATASET_VALID(sigrdataset) &&
526 		 !dns_rdataset_isassociated(sigrdataset)));
527 
528 	if (db->methods->findext != NULL) {
529 		return ((db->methods->findext)(
530 			db, name, version, type, options, now, nodep, foundname,
531 			methods, clientinfo, rdataset, sigrdataset));
532 	} else {
533 		return ((db->methods->find)(db, name, version, type, options,
534 					    now, nodep, foundname, rdataset,
535 					    sigrdataset));
536 	}
537 }
538 
539 isc_result_t
540 dns_db_findzonecut(dns_db_t *db, const dns_name_t *name, unsigned int options,
541 		   isc_stdtime_t now, dns_dbnode_t **nodep,
542 		   dns_name_t *foundname, dns_name_t *dcname,
543 		   dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset) {
544 	/*
545 	 * Find the deepest known zonecut which encloses 'name' in 'db'.
546 	 * foundname is the zonecut, dcname is the deepest name we have
547 	 * in database that is part of queried name.
548 	 */
549 
550 	REQUIRE(DNS_DB_VALID(db));
551 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);
552 	REQUIRE(nodep == NULL || *nodep == NULL);
553 	REQUIRE(dns_name_hasbuffer(foundname));
554 	REQUIRE(sigrdataset == NULL ||
555 		(DNS_RDATASET_VALID(sigrdataset) &&
556 		 !dns_rdataset_isassociated(sigrdataset)));
557 
558 	return ((db->methods->findzonecut)(db, name, options, now, nodep,
559 					   foundname, dcname, rdataset,
560 					   sigrdataset));
561 }
562 
563 void
564 dns_db_attachnode(dns_db_t *db, dns_dbnode_t *source, dns_dbnode_t **targetp) {
565 	/*
566 	 * Attach *targetp to source.
567 	 */
568 
569 	REQUIRE(DNS_DB_VALID(db));
570 	REQUIRE(source != NULL);
571 	REQUIRE(targetp != NULL && *targetp == NULL);
572 
573 	(db->methods->attachnode)(db, source, targetp);
574 }
575 
576 void
577 dns_db_detachnode(dns_db_t *db, dns_dbnode_t **nodep) {
578 	/*
579 	 * Detach *nodep from its node.
580 	 */
581 
582 	REQUIRE(DNS_DB_VALID(db));
583 	REQUIRE(nodep != NULL && *nodep != NULL);
584 
585 	(db->methods->detachnode)(db, nodep);
586 
587 	ENSURE(*nodep == NULL);
588 }
589 
590 void
591 dns_db_transfernode(dns_db_t *db, dns_dbnode_t **sourcep,
592 		    dns_dbnode_t **targetp) {
593 	REQUIRE(DNS_DB_VALID(db));
594 	REQUIRE(targetp != NULL && *targetp == NULL);
595 	/*
596 	 * This doesn't check the implementation magic.  If we find that
597 	 * we need such checks in future then this will be done in the
598 	 * method.
599 	 */
600 	REQUIRE(sourcep != NULL && *sourcep != NULL);
601 
602 	UNUSED(db);
603 
604 	if (db->methods->transfernode == NULL) {
605 		*targetp = *sourcep;
606 		*sourcep = NULL;
607 	} else {
608 		(db->methods->transfernode)(db, sourcep, targetp);
609 	}
610 
611 	ENSURE(*sourcep == NULL);
612 }
613 
614 isc_result_t
615 dns_db_expirenode(dns_db_t *db, dns_dbnode_t *node, isc_stdtime_t now) {
616 	/*
617 	 * Mark as stale all records at 'node' which expire at or before 'now'.
618 	 */
619 
620 	REQUIRE(DNS_DB_VALID(db));
621 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);
622 	REQUIRE(node != NULL);
623 
624 	return ((db->methods->expirenode)(db, node, now));
625 }
626 
627 void
628 dns_db_printnode(dns_db_t *db, dns_dbnode_t *node, FILE *out) {
629 	/*
630 	 * Print a textual representation of the contents of the node to
631 	 * 'out'.
632 	 */
633 
634 	REQUIRE(DNS_DB_VALID(db));
635 	REQUIRE(node != NULL);
636 
637 	(db->methods->printnode)(db, node, out);
638 }
639 
640 /***
641  *** DB Iterator Creation
642  ***/
643 
644 isc_result_t
645 dns_db_createiterator(dns_db_t *db, unsigned int flags,
646 		      dns_dbiterator_t **iteratorp) {
647 	/*
648 	 * Create an iterator for version 'version' of 'db'.
649 	 */
650 
651 	REQUIRE(DNS_DB_VALID(db));
652 	REQUIRE(iteratorp != NULL && *iteratorp == NULL);
653 
654 	return (db->methods->createiterator(db, flags, iteratorp));
655 }
656 
657 /***
658  *** Rdataset Methods
659  ***/
660 
661 isc_result_t
662 dns_db_findrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
663 		    dns_rdatatype_t type, dns_rdatatype_t covers,
664 		    isc_stdtime_t now, dns_rdataset_t *rdataset,
665 		    dns_rdataset_t *sigrdataset) {
666 	REQUIRE(DNS_DB_VALID(db));
667 	REQUIRE(node != NULL);
668 	REQUIRE(DNS_RDATASET_VALID(rdataset));
669 	REQUIRE(!dns_rdataset_isassociated(rdataset));
670 	REQUIRE(covers == 0 || type == dns_rdatatype_rrsig);
671 	REQUIRE(type != dns_rdatatype_any);
672 	REQUIRE(sigrdataset == NULL ||
673 		(DNS_RDATASET_VALID(sigrdataset) &&
674 		 !dns_rdataset_isassociated(sigrdataset)));
675 
676 	return ((db->methods->findrdataset)(db, node, version, type, covers,
677 					    now, rdataset, sigrdataset));
678 }
679 
680 isc_result_t
681 dns_db_allrdatasets(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
682 		    unsigned int options, isc_stdtime_t now,
683 		    dns_rdatasetiter_t **iteratorp) {
684 	/*
685 	 * Make '*iteratorp' an rdataset iteratator for all rdatasets at
686 	 * 'node' in version 'version' of 'db'.
687 	 */
688 
689 	REQUIRE(DNS_DB_VALID(db));
690 	REQUIRE(iteratorp != NULL && *iteratorp == NULL);
691 
692 	return ((db->methods->allrdatasets)(db, node, version, options, now,
693 					    iteratorp));
694 }
695 
696 isc_result_t
697 dns_db_addrdataset(dns_db_t *db, dns_dbnode_t *node, dns_dbversion_t *version,
698 		   isc_stdtime_t now, dns_rdataset_t *rdataset,
699 		   unsigned int options, dns_rdataset_t *addedrdataset) {
700 	/*
701 	 * Add 'rdataset' to 'node' in version 'version' of 'db'.
702 	 */
703 
704 	REQUIRE(DNS_DB_VALID(db));
705 	REQUIRE(node != NULL);
706 	REQUIRE(((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL) ||
707 		((db->attributes & DNS_DBATTR_CACHE) != 0 && version == NULL &&
708 		 (options & DNS_DBADD_MERGE) == 0));
709 	REQUIRE((options & DNS_DBADD_EXACT) == 0 ||
710 		(options & DNS_DBADD_MERGE) != 0);
711 	REQUIRE(DNS_RDATASET_VALID(rdataset));
712 	REQUIRE(dns_rdataset_isassociated(rdataset));
713 	REQUIRE(rdataset->rdclass == db->rdclass);
714 	REQUIRE(addedrdataset == NULL ||
715 		(DNS_RDATASET_VALID(addedrdataset) &&
716 		 !dns_rdataset_isassociated(addedrdataset)));
717 
718 	return ((db->methods->addrdataset)(db, node, version, now, rdataset,
719 					   options, addedrdataset));
720 }
721 
722 isc_result_t
723 dns_db_subtractrdataset(dns_db_t *db, dns_dbnode_t *node,
724 			dns_dbversion_t *version, dns_rdataset_t *rdataset,
725 			unsigned int options, dns_rdataset_t *newrdataset) {
726 	/*
727 	 * Remove any rdata in 'rdataset' from 'node' in version 'version' of
728 	 * 'db'.
729 	 */
730 
731 	REQUIRE(DNS_DB_VALID(db));
732 	REQUIRE(node != NULL);
733 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL);
734 	REQUIRE(DNS_RDATASET_VALID(rdataset));
735 	REQUIRE(dns_rdataset_isassociated(rdataset));
736 	REQUIRE(rdataset->rdclass == db->rdclass);
737 	REQUIRE(newrdataset == NULL ||
738 		(DNS_RDATASET_VALID(newrdataset) &&
739 		 !dns_rdataset_isassociated(newrdataset)));
740 
741 	return ((db->methods->subtractrdataset)(db, node, version, rdataset,
742 						options, newrdataset));
743 }
744 
745 isc_result_t
746 dns_db_deleterdataset(dns_db_t *db, dns_dbnode_t *node,
747 		      dns_dbversion_t *version, dns_rdatatype_t type,
748 		      dns_rdatatype_t covers) {
749 	/*
750 	 * Make it so that no rdataset of type 'type' exists at 'node' in
751 	 * version version 'version' of 'db'.
752 	 */
753 
754 	REQUIRE(DNS_DB_VALID(db));
755 	REQUIRE(node != NULL);
756 	REQUIRE(((db->attributes & DNS_DBATTR_CACHE) == 0 && version != NULL) ||
757 		((db->attributes & DNS_DBATTR_CACHE) != 0 && version == NULL));
758 
759 	return ((db->methods->deleterdataset)(db, node, version, type, covers));
760 }
761 
762 void
763 dns_db_overmem(dns_db_t *db, bool overmem) {
764 	REQUIRE(DNS_DB_VALID(db));
765 
766 	(db->methods->overmem)(db, overmem);
767 }
768 
769 isc_result_t
770 dns_db_getsoaserial(dns_db_t *db, dns_dbversion_t *ver, uint32_t *serialp) {
771 	isc_result_t result;
772 	dns_dbnode_t *node = NULL;
773 	dns_rdataset_t rdataset;
774 	dns_rdata_t rdata = DNS_RDATA_INIT;
775 	isc_buffer_t buffer;
776 
777 	REQUIRE(dns_db_iszone(db) || dns_db_isstub(db));
778 
779 	result = dns_db_findnode(db, dns_db_origin(db), false, &node);
780 	if (result != ISC_R_SUCCESS) {
781 		return (result);
782 	}
783 
784 	dns_rdataset_init(&rdataset);
785 	result = dns_db_findrdataset(db, node, ver, dns_rdatatype_soa, 0,
786 				     (isc_stdtime_t)0, &rdataset, NULL);
787 	if (result != ISC_R_SUCCESS) {
788 		goto freenode;
789 	}
790 
791 	result = dns_rdataset_first(&rdataset);
792 	if (result != ISC_R_SUCCESS) {
793 		goto freerdataset;
794 	}
795 	dns_rdataset_current(&rdataset, &rdata);
796 	result = dns_rdataset_next(&rdataset);
797 	INSIST(result == ISC_R_NOMORE);
798 
799 	INSIST(rdata.length > 20);
800 	isc_buffer_init(&buffer, rdata.data, rdata.length);
801 	isc_buffer_add(&buffer, rdata.length);
802 	isc_buffer_forward(&buffer, rdata.length - 20);
803 	*serialp = isc_buffer_getuint32(&buffer);
804 
805 	result = ISC_R_SUCCESS;
806 
807 freerdataset:
808 	dns_rdataset_disassociate(&rdataset);
809 
810 freenode:
811 	dns_db_detachnode(db, &node);
812 	return (result);
813 }
814 
815 unsigned int
816 dns_db_nodecount(dns_db_t *db, dns_dbtree_t tree) {
817 	REQUIRE(DNS_DB_VALID(db));
818 
819 	return ((db->methods->nodecount)(db, tree));
820 }
821 
822 size_t
823 dns_db_hashsize(dns_db_t *db) {
824 	REQUIRE(DNS_DB_VALID(db));
825 
826 	if (db->methods->hashsize == NULL) {
827 		return (0);
828 	}
829 
830 	return ((db->methods->hashsize)(db));
831 }
832 
833 void
834 dns_db_settask(dns_db_t *db, isc_task_t *task) {
835 	REQUIRE(DNS_DB_VALID(db));
836 
837 	(db->methods->settask)(db, task);
838 }
839 
840 isc_result_t
841 dns_db_register(const char *name, dns_dbcreatefunc_t create, void *driverarg,
842 		isc_mem_t *mctx, dns_dbimplementation_t **dbimp) {
843 	dns_dbimplementation_t *imp;
844 
845 	REQUIRE(name != NULL);
846 	REQUIRE(dbimp != NULL && *dbimp == NULL);
847 
848 	RUNTIME_CHECK(isc_once_do(&once, initialize) == ISC_R_SUCCESS);
849 
850 	RWLOCK(&implock, isc_rwlocktype_write);
851 	imp = impfind(name);
852 	if (imp != NULL) {
853 		RWUNLOCK(&implock, isc_rwlocktype_write);
854 		return (ISC_R_EXISTS);
855 	}
856 
857 	imp = isc_mem_get(mctx, sizeof(dns_dbimplementation_t));
858 	imp->name = name;
859 	imp->create = create;
860 	imp->mctx = NULL;
861 	imp->driverarg = driverarg;
862 	isc_mem_attach(mctx, &imp->mctx);
863 	ISC_LINK_INIT(imp, link);
864 	ISC_LIST_APPEND(implementations, imp, link);
865 	RWUNLOCK(&implock, isc_rwlocktype_write);
866 
867 	*dbimp = imp;
868 
869 	return (ISC_R_SUCCESS);
870 }
871 
872 void
873 dns_db_unregister(dns_dbimplementation_t **dbimp) {
874 	dns_dbimplementation_t *imp;
875 
876 	REQUIRE(dbimp != NULL && *dbimp != NULL);
877 
878 	RUNTIME_CHECK(isc_once_do(&once, initialize) == ISC_R_SUCCESS);
879 
880 	imp = *dbimp;
881 	*dbimp = NULL;
882 	RWLOCK(&implock, isc_rwlocktype_write);
883 	ISC_LIST_UNLINK(implementations, imp, link);
884 	isc_mem_putanddetach(&imp->mctx, imp, sizeof(dns_dbimplementation_t));
885 	RWUNLOCK(&implock, isc_rwlocktype_write);
886 	ENSURE(*dbimp == NULL);
887 }
888 
889 isc_result_t
890 dns_db_getoriginnode(dns_db_t *db, dns_dbnode_t **nodep) {
891 	REQUIRE(DNS_DB_VALID(db));
892 	REQUIRE(dns_db_iszone(db));
893 	REQUIRE(nodep != NULL && *nodep == NULL);
894 
895 	if (db->methods->getoriginnode != NULL) {
896 		return ((db->methods->getoriginnode)(db, nodep));
897 	}
898 
899 	return (ISC_R_NOTFOUND);
900 }
901 
902 dns_stats_t *
903 dns_db_getrrsetstats(dns_db_t *db) {
904 	REQUIRE(DNS_DB_VALID(db));
905 
906 	if (db->methods->getrrsetstats != NULL) {
907 		return ((db->methods->getrrsetstats)(db));
908 	}
909 
910 	return (NULL);
911 }
912 
913 isc_result_t
914 dns_db_setcachestats(dns_db_t *db, isc_stats_t *stats) {
915 	REQUIRE(DNS_DB_VALID(db));
916 
917 	if (db->methods->setcachestats != NULL) {
918 		return ((db->methods->setcachestats)(db, stats));
919 	}
920 
921 	return (ISC_R_NOTIMPLEMENTED);
922 }
923 
924 isc_result_t
925 dns_db_getnsec3parameters(dns_db_t *db, dns_dbversion_t *version,
926 			  dns_hash_t *hash, uint8_t *flags,
927 			  uint16_t *iterations, unsigned char *salt,
928 			  size_t *salt_length) {
929 	REQUIRE(DNS_DB_VALID(db));
930 	REQUIRE(dns_db_iszone(db));
931 
932 	if (db->methods->getnsec3parameters != NULL) {
933 		return ((db->methods->getnsec3parameters)(db, version, hash,
934 							  flags, iterations,
935 							  salt, salt_length));
936 	}
937 
938 	return (ISC_R_NOTFOUND);
939 }
940 
941 isc_result_t
942 dns_db_getsize(dns_db_t *db, dns_dbversion_t *version, uint64_t *records,
943 	       uint64_t *bytes) {
944 	REQUIRE(DNS_DB_VALID(db));
945 	REQUIRE(dns_db_iszone(db));
946 
947 	if (db->methods->getsize != NULL) {
948 		return ((db->methods->getsize)(db, version, records, bytes));
949 	}
950 
951 	return (ISC_R_NOTFOUND);
952 }
953 
954 isc_result_t
955 dns_db_setsigningtime(dns_db_t *db, dns_rdataset_t *rdataset,
956 		      isc_stdtime_t resign) {
957 	if (db->methods->setsigningtime != NULL) {
958 		return ((db->methods->setsigningtime)(db, rdataset, resign));
959 	}
960 	return (ISC_R_NOTIMPLEMENTED);
961 }
962 
963 isc_result_t
964 dns_db_getsigningtime(dns_db_t *db, dns_rdataset_t *rdataset,
965 		      dns_name_t *name) {
966 	if (db->methods->getsigningtime != NULL) {
967 		return ((db->methods->getsigningtime)(db, rdataset, name));
968 	}
969 	return (ISC_R_NOTFOUND);
970 }
971 
972 void
973 dns_db_resigned(dns_db_t *db, dns_rdataset_t *rdataset,
974 		dns_dbversion_t *version) {
975 	if (db->methods->resigned != NULL) {
976 		(db->methods->resigned)(db, rdataset, version);
977 	}
978 }
979 
980 /*
981  * Attach a database to policy zone databases.
982  * This should only happen when the caller has already ensured that
983  * it is dealing with a database that understands response policy zones.
984  */
985 void
986 dns_db_rpz_attach(dns_db_t *db, void *rpzs, uint8_t rpz_num) {
987 	REQUIRE(db->methods->rpz_attach != NULL);
988 	(db->methods->rpz_attach)(db, rpzs, rpz_num);
989 }
990 
991 /*
992  * Finish loading a response policy zone.
993  */
994 isc_result_t
995 dns_db_rpz_ready(dns_db_t *db) {
996 	if (db->methods->rpz_ready == NULL) {
997 		return (ISC_R_SUCCESS);
998 	}
999 	return ((db->methods->rpz_ready)(db));
1000 }
1001 
1002 /*
1003  * Attach a notify-on-update function the database
1004  */
1005 isc_result_t
1006 dns_db_updatenotify_register(dns_db_t *db, dns_dbupdate_callback_t fn,
1007 			     void *fn_arg) {
1008 	dns_dbonupdatelistener_t *listener;
1009 
1010 	REQUIRE(db != NULL);
1011 	REQUIRE(fn != NULL);
1012 
1013 	for (listener = ISC_LIST_HEAD(db->update_listeners); listener != NULL;
1014 	     listener = ISC_LIST_NEXT(listener, link))
1015 	{
1016 		if ((listener->onupdate == fn) &&
1017 		    (listener->onupdate_arg == fn_arg))
1018 		{
1019 			return (ISC_R_SUCCESS);
1020 		}
1021 	}
1022 
1023 	listener = isc_mem_get(db->mctx, sizeof(dns_dbonupdatelistener_t));
1024 
1025 	listener->onupdate = fn;
1026 	listener->onupdate_arg = fn_arg;
1027 
1028 	ISC_LINK_INIT(listener, link);
1029 	ISC_LIST_APPEND(db->update_listeners, listener, link);
1030 
1031 	return (ISC_R_SUCCESS);
1032 }
1033 
1034 isc_result_t
1035 dns_db_updatenotify_unregister(dns_db_t *db, dns_dbupdate_callback_t fn,
1036 			       void *fn_arg) {
1037 	dns_dbonupdatelistener_t *listener;
1038 
1039 	REQUIRE(db != NULL);
1040 
1041 	for (listener = ISC_LIST_HEAD(db->update_listeners); listener != NULL;
1042 	     listener = ISC_LIST_NEXT(listener, link))
1043 	{
1044 		if ((listener->onupdate == fn) &&
1045 		    (listener->onupdate_arg == fn_arg))
1046 		{
1047 			ISC_LIST_UNLINK(db->update_listeners, listener, link);
1048 			isc_mem_put(db->mctx, listener,
1049 				    sizeof(dns_dbonupdatelistener_t));
1050 			return (ISC_R_SUCCESS);
1051 		}
1052 	}
1053 
1054 	return (ISC_R_NOTFOUND);
1055 }
1056 
1057 isc_result_t
1058 dns_db_nodefullname(dns_db_t *db, dns_dbnode_t *node, dns_name_t *name) {
1059 	REQUIRE(db != NULL);
1060 	REQUIRE(node != NULL);
1061 	REQUIRE(name != NULL);
1062 
1063 	if (db->methods->nodefullname == NULL) {
1064 		return (ISC_R_NOTIMPLEMENTED);
1065 	}
1066 	return ((db->methods->nodefullname)(db, node, name));
1067 }
1068 
1069 isc_result_t
1070 dns_db_setservestalettl(dns_db_t *db, dns_ttl_t ttl) {
1071 	REQUIRE(DNS_DB_VALID(db));
1072 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);
1073 
1074 	if (db->methods->setservestalettl != NULL) {
1075 		return ((db->methods->setservestalettl)(db, ttl));
1076 	}
1077 	return (ISC_R_NOTIMPLEMENTED);
1078 }
1079 
1080 isc_result_t
1081 dns_db_getservestalettl(dns_db_t *db, dns_ttl_t *ttl) {
1082 	REQUIRE(DNS_DB_VALID(db));
1083 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);
1084 
1085 	if (db->methods->getservestalettl != NULL) {
1086 		return ((db->methods->getservestalettl)(db, ttl));
1087 	}
1088 	return (ISC_R_NOTIMPLEMENTED);
1089 }
1090 
1091 isc_result_t
1092 dns_db_setservestalerefresh(dns_db_t *db, uint32_t interval) {
1093 	REQUIRE(DNS_DB_VALID(db));
1094 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);
1095 
1096 	if (db->methods->setservestalerefresh != NULL) {
1097 		return ((db->methods->setservestalerefresh)(db, interval));
1098 	}
1099 	return (ISC_R_NOTIMPLEMENTED);
1100 }
1101 
1102 isc_result_t
1103 dns_db_getservestalerefresh(dns_db_t *db, uint32_t *interval) {
1104 	REQUIRE(DNS_DB_VALID(db));
1105 	REQUIRE((db->attributes & DNS_DBATTR_CACHE) != 0);
1106 
1107 	if (db->methods->getservestalerefresh != NULL) {
1108 		return ((db->methods->getservestalerefresh)(db, interval));
1109 	}
1110 	return (ISC_R_NOTIMPLEMENTED);
1111 }
1112 
1113 isc_result_t
1114 dns_db_setgluecachestats(dns_db_t *db, isc_stats_t *stats) {
1115 	REQUIRE(dns_db_iszone(db));
1116 	REQUIRE(stats != NULL);
1117 
1118 	if (db->methods->setgluecachestats != NULL) {
1119 		return ((db->methods->setgluecachestats)(db, stats));
1120 	}
1121 
1122 	return (ISC_R_NOTIMPLEMENTED);
1123 }
1124