1/*
2 * Copyright (C) 2004-2012  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1999-2003  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: rdataset.h,v 1.72 2011/06/08 22:13:51 each Exp $ */
19
20#ifndef DNS_RDATASET_H
21#define DNS_RDATASET_H 1
22
23/*****
24 ***** Module Info
25 *****/
26
27/*! \file dns/rdataset.h
28 * \brief
29 * A DNS rdataset is a handle that can be associated with a collection of
30 * rdata all having a common owner name, class, and type.
31 *
32 * The dns_rdataset_t type is like a "virtual class".  To actually use
33 * rdatasets, an implementation of the method suite (e.g. "slabbed rdata") is
34 * required.
35 *
36 * XXX <more> XXX
37 *
38 * MP:
39 *\li	Clients of this module must impose any required synchronization.
40 *
41 * Reliability:
42 *\li	No anticipated impact.
43 *
44 * Resources:
45 *\li	TBS
46 *
47 * Security:
48 *\li	No anticipated impact.
49 *
50 * Standards:
51 *\li	None.
52 */
53
54#include <isc/lang.h>
55#include <isc/magic.h>
56#include <isc/stdtime.h>
57
58#include <dns/types.h>
59#include <dns/rdatastruct.h>
60
61ISC_LANG_BEGINDECLS
62
63typedef enum {
64	dns_rdatasetadditional_fromauth,
65	dns_rdatasetadditional_fromcache,
66	dns_rdatasetadditional_fromglue
67} dns_rdatasetadditional_t;
68
69typedef struct dns_rdatasetmethods {
70	void			(*disassociate)(dns_rdataset_t *rdataset);
71	isc_result_t		(*first)(dns_rdataset_t *rdataset);
72	isc_result_t		(*next)(dns_rdataset_t *rdataset);
73	void			(*current)(dns_rdataset_t *rdataset,
74					   dns_rdata_t *rdata);
75	void			(*clone)(dns_rdataset_t *source,
76					 dns_rdataset_t *target);
77	unsigned int		(*count)(dns_rdataset_t *rdataset);
78	isc_result_t		(*addnoqname)(dns_rdataset_t *rdataset,
79					      dns_name_t *name);
80	isc_result_t		(*getnoqname)(dns_rdataset_t *rdataset,
81					      dns_name_t *name,
82					      dns_rdataset_t *neg,
83					      dns_rdataset_t *negsig);
84	isc_result_t		(*addclosest)(dns_rdataset_t *rdataset,
85					      dns_name_t *name);
86	isc_result_t		(*getclosest)(dns_rdataset_t *rdataset,
87					      dns_name_t *name,
88					      dns_rdataset_t *neg,
89					      dns_rdataset_t *negsig);
90	isc_result_t		(*getadditional)(dns_rdataset_t *rdataset,
91						 dns_rdatasetadditional_t type,
92						 dns_rdatatype_t qtype,
93						 dns_acache_t *acache,
94						 dns_zone_t **zonep,
95						 dns_db_t **dbp,
96						 dns_dbversion_t **versionp,
97						 dns_dbnode_t **nodep,
98						 dns_name_t *fname,
99						 dns_message_t *msg,
100						 isc_stdtime_t now);
101	isc_result_t		(*setadditional)(dns_rdataset_t *rdataset,
102						 dns_rdatasetadditional_t type,
103						 dns_rdatatype_t qtype,
104						 dns_acache_t *acache,
105						 dns_zone_t *zone,
106						 dns_db_t *db,
107						 dns_dbversion_t *version,
108						 dns_dbnode_t *node,
109						 dns_name_t *fname);
110	isc_result_t		(*putadditional)(dns_acache_t *acache,
111						 dns_rdataset_t *rdataset,
112						 dns_rdatasetadditional_t type,
113						 dns_rdatatype_t qtype);
114	void			(*settrust)(dns_rdataset_t *rdataset,
115					    dns_trust_t trust);
116	void			(*expire)(dns_rdataset_t *rdataset);
117} dns_rdatasetmethods_t;
118
119#define DNS_RDATASET_MAGIC	       ISC_MAGIC('D','N','S','R')
120#define DNS_RDATASET_VALID(set)	       ISC_MAGIC_VALID(set, DNS_RDATASET_MAGIC)
121
122/*%
123 * Direct use of this structure by clients is strongly discouraged, except
124 * for the 'link' field which may be used however the client wishes.  The
125 * 'private', 'current', and 'index' fields MUST NOT be changed by clients.
126 * rdataset implementations may change any of the fields.
127 */
128struct dns_rdataset {
129	unsigned int			magic;		/* XXX ? */
130	dns_rdatasetmethods_t *		methods;
131	ISC_LINK(dns_rdataset_t)	link;
132	/*
133	 * XXX do we need these, or should they be retrieved by methods?
134	 * Leaning towards the latter, since they are not frequently required
135	 * once you have the rdataset.
136	 */
137	dns_rdataclass_t		rdclass;
138	dns_rdatatype_t			type;
139	dns_ttl_t			ttl;
140	dns_trust_t			trust;
141	dns_rdatatype_t			covers;
142	/*
143	 * attributes
144	 */
145	unsigned int			attributes;
146	/*%
147	 * the counter provides the starting point in the "cyclic" order.
148	 * The value ISC_UINT32_MAX has a special meaning of "picking up a
149	 * random value." in order to take care of databases that do not
150	 * increment the counter.
151	 */
152	isc_uint32_t			count;
153	/*
154	 * This RRSIG RRset should be re-generated around this time.
155	 * Only valid if DNS_RDATASETATTR_RESIGN is set in attributes.
156	 */
157	isc_stdtime_t			resign;
158	/*@{*/
159	/*%
160	 * These are for use by the rdataset implementation, and MUST NOT
161	 * be changed by clients.
162	 */
163	void *				private1;
164	void *				private2;
165	void *				private3;
166	unsigned int			privateuint4;
167	void *				private5;
168	void *				private6;
169	void *				private7;
170	/*@}*/
171
172};
173
174/*!
175 * \def DNS_RDATASETATTR_RENDERED
176 *	Used by message.c to indicate that the rdataset was rendered.
177 *
178 * \def DNS_RDATASETATTR_TTLADJUSTED
179 *	Used by message.c to indicate that the rdataset's rdata had differing
180 *	TTL values, and the rdataset->ttl holds the smallest.
181 *
182 * \def DNS_RDATASETATTR_LOADORDER
183 *	Output the RRset in load order.
184 */
185
186#define DNS_RDATASETATTR_QUESTION	0x00000001
187#define DNS_RDATASETATTR_RENDERED	0x00000002	/*%< Used by message.c */
188#define DNS_RDATASETATTR_ANSWERED	0x00000004	/*%< Used by server. */
189#define DNS_RDATASETATTR_CACHE		0x00000008	/*%< Used by resolver. */
190#define DNS_RDATASETATTR_ANSWER		0x00000010	/*%< Used by resolver. */
191#define DNS_RDATASETATTR_ANSWERSIG	0x00000020	/*%< Used by resolver. */
192#define DNS_RDATASETATTR_EXTERNAL	0x00000040	/*%< Used by resolver. */
193#define DNS_RDATASETATTR_NCACHE		0x00000080	/*%< Used by resolver. */
194#define DNS_RDATASETATTR_CHAINING	0x00000100	/*%< Used by resolver. */
195#define DNS_RDATASETATTR_TTLADJUSTED	0x00000200	/*%< Used by message.c */
196#define DNS_RDATASETATTR_FIXEDORDER	0x00000400
197#define DNS_RDATASETATTR_RANDOMIZE	0x00000800
198#define DNS_RDATASETATTR_CHASE		0x00001000	/*%< Used by resolver. */
199#define DNS_RDATASETATTR_NXDOMAIN	0x00002000
200#define DNS_RDATASETATTR_NOQNAME	0x00004000
201#define DNS_RDATASETATTR_CHECKNAMES	0x00008000	/*%< Used by resolver. */
202#define DNS_RDATASETATTR_REQUIREDGLUE	0x00010000
203#define DNS_RDATASETATTR_LOADORDER	0x00020000
204#define DNS_RDATASETATTR_RESIGN		0x00040000
205#define DNS_RDATASETATTR_CLOSEST	0x00080000
206#define DNS_RDATASETATTR_OPTOUT		0x00100000	/*%< OPTOUT proof */
207#define DNS_RDATASETATTR_NEGATIVE	0x00200000
208
209/*%
210 * _OMITDNSSEC:
211 * 	Omit DNSSEC records when rendering ncache records.
212 */
213#define DNS_RDATASETTOWIRE_OMITDNSSEC	0x0001
214
215void
216dns_rdataset_init(dns_rdataset_t *rdataset);
217/*%<
218 * Make 'rdataset' a valid, disassociated rdataset.
219 *
220 * Requires:
221 *\li	'rdataset' is not NULL.
222 *
223 * Ensures:
224 *\li	'rdataset' is a valid, disassociated rdataset.
225 */
226
227void
228dns_rdataset_invalidate(dns_rdataset_t *rdataset);
229/*%<
230 * Invalidate 'rdataset'.
231 *
232 * Requires:
233 *\li	'rdataset' is a valid, disassociated rdataset.
234 *
235 * Ensures:
236 *\li	If assertion checking is enabled, future attempts to use 'rdataset'
237 *	without initializing it will cause an assertion failure.
238 */
239
240void
241dns_rdataset_disassociate(dns_rdataset_t *rdataset);
242/*%<
243 * Disassociate 'rdataset' from its rdata, allowing it to be reused.
244 *
245 * Notes:
246 *\li	The client must ensure it has no references to rdata in the rdataset
247 *	before disassociating.
248 *
249 * Requires:
250 *\li	'rdataset' is a valid, associated rdataset.
251 *
252 * Ensures:
253 *\li	'rdataset' is a valid, disassociated rdataset.
254 */
255
256isc_boolean_t
257dns_rdataset_isassociated(dns_rdataset_t *rdataset);
258/*%<
259 * Is 'rdataset' associated?
260 *
261 * Requires:
262 *\li	'rdataset' is a valid rdataset.
263 *
264 * Returns:
265 *\li	#ISC_TRUE			'rdataset' is associated.
266 *\li	#ISC_FALSE			'rdataset' is not associated.
267 */
268
269void
270dns_rdataset_makequestion(dns_rdataset_t *rdataset, dns_rdataclass_t rdclass,
271			  dns_rdatatype_t type);
272/*%<
273 * Make 'rdataset' a valid, associated, question rdataset, with a
274 * question class of 'rdclass' and type 'type'.
275 *
276 * Notes:
277 *\li	Question rdatasets have a class and type, but no rdata.
278 *
279 * Requires:
280 *\li	'rdataset' is a valid, disassociated rdataset.
281 *
282 * Ensures:
283 *\li	'rdataset' is a valid, associated, question rdataset.
284 */
285
286void
287dns_rdataset_clone(dns_rdataset_t *source, dns_rdataset_t *target);
288/*%<
289 * Make 'target' refer to the same rdataset as 'source'.
290 *
291 * Requires:
292 *\li	'source' is a valid, associated rdataset.
293 *
294 *\li	'target' is a valid, dissociated rdataset.
295 *
296 * Ensures:
297 *\li	'target' references the same rdataset as 'source'.
298 */
299
300unsigned int
301dns_rdataset_count(dns_rdataset_t *rdataset);
302/*%<
303 * Return the number of records in 'rdataset'.
304 *
305 * Requires:
306 *\li	'rdataset' is a valid, associated rdataset.
307 *
308 * Returns:
309 *\li	The number of records in 'rdataset'.
310 */
311
312isc_result_t
313dns_rdataset_first(dns_rdataset_t *rdataset);
314/*%<
315 * Move the rdata cursor to the first rdata in the rdataset (if any).
316 *
317 * Requires:
318 *\li	'rdataset' is a valid, associated rdataset.
319 *
320 * Returns:
321 *\li	#ISC_R_SUCCESS
322 *\li	#ISC_R_NOMORE			There are no rdata in the set.
323 */
324
325isc_result_t
326dns_rdataset_next(dns_rdataset_t *rdataset);
327/*%<
328 * Move the rdata cursor to the next rdata in the rdataset (if any).
329 *
330 * Requires:
331 *\li	'rdataset' is a valid, associated rdataset.
332 *
333 * Returns:
334 *\li	#ISC_R_SUCCESS
335 *\li	#ISC_R_NOMORE			There are no more rdata in the set.
336 */
337
338void
339dns_rdataset_current(dns_rdataset_t *rdataset, dns_rdata_t *rdata);
340/*%<
341 * Make 'rdata' refer to the current rdata.
342 *
343 * Notes:
344 *
345 *\li	The data returned in 'rdata' is valid for the life of the
346 *	rdataset; in particular, subsequent changes in the cursor position
347 *	do not invalidate 'rdata'.
348 *
349 * Requires:
350 *\li	'rdataset' is a valid, associated rdataset.
351 *
352 *\li	The rdata cursor of 'rdataset' is at a valid location (i.e. the
353 *	result of last call to a cursor movement command was ISC_R_SUCCESS).
354 *
355 * Ensures:
356 *\li	'rdata' refers to the rdata at the rdata cursor location of
357 *\li	'rdataset'.
358 */
359
360isc_result_t
361dns_rdataset_totext(dns_rdataset_t *rdataset,
362		    dns_name_t *owner_name,
363		    isc_boolean_t omit_final_dot,
364		    isc_boolean_t question,
365		    isc_buffer_t *target);
366/*%<
367 * Convert 'rdataset' to text format, storing the result in 'target'.
368 *
369 * Notes:
370 *\li	The rdata cursor position will be changed.
371 *
372 *\li	The 'question' flag should normally be #ISC_FALSE.  If it is
373 *	#ISC_TRUE, the TTL and rdata fields are not printed.  This is
374 *	for use when printing an rdata representing a question section.
375 *
376 *\li	This interface is deprecated; use dns_master_rdatasettottext()
377 * 	and/or dns_master_questiontotext() instead.
378 *
379 * Requires:
380 *\li	'rdataset' is a valid rdataset.
381 *
382 *\li	'rdataset' is not empty.
383 */
384
385isc_result_t
386dns_rdataset_towire(dns_rdataset_t *rdataset,
387		    dns_name_t *owner_name,
388		    dns_compress_t *cctx,
389		    isc_buffer_t *target,
390		    unsigned int options,
391		    unsigned int *countp);
392/*%<
393 * Convert 'rdataset' to wire format, compressing names as specified
394 * in 'cctx', and storing the result in 'target'.
395 *
396 * Notes:
397 *\li	The rdata cursor position will be changed.
398 *
399 *\li	The number of RRs added to target will be added to *countp.
400 *
401 * Requires:
402 *\li	'rdataset' is a valid rdataset.
403 *
404 *\li	'rdataset' is not empty.
405 *
406 *\li	'countp' is a valid pointer.
407 *
408 * Ensures:
409 *\li	On a return of ISC_R_SUCCESS, 'target' contains a wire format
410 *	for the data contained in 'rdataset'.  Any error return leaves
411 *	the buffer unchanged.
412 *
413 *\li	*countp has been incremented by the number of RRs added to
414 *	target.
415 *
416 * Returns:
417 *\li	#ISC_R_SUCCESS		- all ok
418 *\li	#ISC_R_NOSPACE		- 'target' doesn't have enough room
419 *
420 *\li	Any error returned by dns_rdata_towire(), dns_rdataset_next(),
421 *	dns_name_towire().
422 */
423
424isc_result_t
425dns_rdataset_towiresorted(dns_rdataset_t *rdataset,
426			  const dns_name_t *owner_name,
427			  dns_compress_t *cctx,
428			  isc_buffer_t *target,
429			  dns_rdatasetorderfunc_t order,
430			  const void *order_arg,
431			  unsigned int options,
432			  unsigned int *countp);
433/*%<
434 * Like dns_rdataset_towire(), but sorting the rdatasets according to
435 * the integer value returned by 'order' when called with the rdataset
436 * and 'order_arg' as arguments.
437 *
438 * Requires:
439 *\li	All the requirements of dns_rdataset_towire(), and
440 *	that order_arg is NULL if and only if order is NULL.
441 */
442
443isc_result_t
444dns_rdataset_towirepartial(dns_rdataset_t *rdataset,
445			   const dns_name_t *owner_name,
446			   dns_compress_t *cctx,
447			   isc_buffer_t *target,
448			   dns_rdatasetorderfunc_t order,
449			   const void *order_arg,
450			   unsigned int options,
451			   unsigned int *countp,
452			   void **state);
453/*%<
454 * Like dns_rdataset_towiresorted() except that a partial rdataset
455 * may be written.
456 *
457 * Requires:
458 *\li	All the requirements of dns_rdataset_towiresorted().
459 *	If 'state' is non NULL then the current position in the
460 *	rdataset will be remembered if the rdataset in not
461 *	completely written and should be passed on on subsequent
462 *	calls (NOT CURRENTLY IMPLEMENTED).
463 *
464 * Returns:
465 *\li	#ISC_R_SUCCESS if all of the records were written.
466 *\li	#ISC_R_NOSPACE if unable to fit in all of the records. *countp
467 *		      will be updated to reflect the number of records
468 *		      written.
469 */
470
471isc_result_t
472dns_rdataset_additionaldata(dns_rdataset_t *rdataset,
473			    dns_additionaldatafunc_t add, void *arg);
474/*%<
475 * For each rdata in rdataset, call 'add' for each name and type in the
476 * rdata which is subject to additional section processing.
477 *
478 * Requires:
479 *
480 *\li	'rdataset' is a valid, non-question rdataset.
481 *
482 *\li	'add' is a valid dns_additionaldatafunc_t
483 *
484 * Ensures:
485 *
486 *\li	If successful, dns_rdata_additionaldata() will have been called for
487 *	each rdata in 'rdataset'.
488 *
489 *\li	If a call to dns_rdata_additionaldata() is not successful, the
490 *	result returned will be the result of dns_rdataset_additionaldata().
491 *
492 * Returns:
493 *
494 *\li	#ISC_R_SUCCESS
495 *
496 *\li	Any error that dns_rdata_additionaldata() can return.
497 */
498
499isc_result_t
500dns_rdataset_getnoqname(dns_rdataset_t *rdataset, dns_name_t *name,
501			dns_rdataset_t *neg, dns_rdataset_t *negsig);
502/*%<
503 * Return the noqname proof for this record.
504 *
505 * Requires:
506 *\li	'rdataset' to be valid and #DNS_RDATASETATTR_NOQNAME to be set.
507 *\li	'name' to be valid.
508 *\li	'neg' and 'negsig' to be valid and not associated.
509 */
510
511isc_result_t
512dns_rdataset_addnoqname(dns_rdataset_t *rdataset, dns_name_t *name);
513/*%<
514 * Associate a noqname proof with this record.
515 * Sets #DNS_RDATASETATTR_NOQNAME if successful.
516 * Adjusts the 'rdataset->ttl' to minimum of the 'rdataset->ttl' and
517 * the 'nsec'/'nsec3' and 'rrsig(nsec)'/'rrsig(nsec3)' ttl.
518 *
519 * Requires:
520 *\li	'rdataset' to be valid and #DNS_RDATASETATTR_NOQNAME to be set.
521 *\li	'name' to be valid and have NSEC or NSEC3 and associated RRSIG
522 *	 rdatasets.
523 */
524
525isc_result_t
526dns_rdataset_getclosest(dns_rdataset_t *rdataset, dns_name_t *name,
527			dns_rdataset_t *nsec, dns_rdataset_t *nsecsig);
528/*%<
529 * Return the closest encloser for this record.
530 *
531 * Requires:
532 *\li	'rdataset' to be valid and #DNS_RDATASETATTR_CLOSEST to be set.
533 *\li	'name' to be valid.
534 *\li	'nsec' and 'nsecsig' to be valid and not associated.
535 */
536
537isc_result_t
538dns_rdataset_addclosest(dns_rdataset_t *rdataset, dns_name_t *name);
539/*%<
540 * Associate a closest encloset proof with this record.
541 * Sets #DNS_RDATASETATTR_CLOSEST if successful.
542 * Adjusts the 'rdataset->ttl' to minimum of the 'rdataset->ttl' and
543 * the 'nsec' and 'rrsig(nsec)' ttl.
544 *
545 * Requires:
546 *\li	'rdataset' to be valid and #DNS_RDATASETATTR_CLOSEST to be set.
547 *\li	'name' to be valid and have NSEC3 and RRSIG(NSEC3) rdatasets.
548 */
549
550isc_result_t
551dns_rdataset_getadditional(dns_rdataset_t *rdataset,
552			   dns_rdatasetadditional_t type,
553			   dns_rdatatype_t qtype,
554			   dns_acache_t *acache,
555			   dns_zone_t **zonep,
556			   dns_db_t **dbp,
557			   dns_dbversion_t **versionp,
558			   dns_dbnode_t **nodep,
559			   dns_name_t *fname,
560			   dns_message_t *msg,
561			   isc_stdtime_t now);
562/*%<
563 * Get cached additional information from the DB node for a particular
564 * 'rdataset.'  'type' is one of dns_rdatasetadditional_fromauth,
565 * dns_rdatasetadditional_fromcache, and dns_rdatasetadditional_fromglue,
566 * which specifies the origin of the information.  'qtype' is intended to
567 * be used for specifying a particular rdata type in the cached information.
568 *
569 * Requires:
570 * \li	'rdataset' is a valid rdataset.
571 * \li	'acache' can be NULL, in which case this function will simply return
572 * 	ISC_R_FAILURE.
573 * \li	For the other pointers, see dns_acache_getentry().
574 *
575 * Ensures:
576 * \li	See dns_acache_getentry().
577 *
578 * Returns:
579 * \li	#ISC_R_SUCCESS
580 * \li	#ISC_R_FAILURE	- additional information caching is not supported.
581 * \li	#ISC_R_NOTFOUND	- the corresponding DB node has not cached additional
582 *			  information for 'rdataset.'
583 * \li	Any error that dns_acache_getentry() can return.
584 */
585
586isc_result_t
587dns_rdataset_setadditional(dns_rdataset_t *rdataset,
588			   dns_rdatasetadditional_t type,
589			   dns_rdatatype_t qtype,
590			   dns_acache_t *acache,
591			   dns_zone_t *zone,
592			   dns_db_t *db,
593			   dns_dbversion_t *version,
594			   dns_dbnode_t *node,
595			   dns_name_t *fname);
596/*%<
597 * Set cached additional information to the DB node for a particular
598 * 'rdataset.'  See dns_rdataset_getadditional for the semantics of 'type'
599 * and 'qtype'.
600 *
601 * Requires:
602 * \li	'rdataset' is a valid rdataset.
603 * \li	'acache' can be NULL, in which case this function will simply return
604 *	ISC_R_FAILURE.
605 * \li	For the other pointers, see dns_acache_setentry().
606 *
607 * Ensures:
608 * \li	See dns_acache_setentry().
609 *
610 * Returns:
611 * \li	#ISC_R_SUCCESS
612 * \li	#ISC_R_FAILURE	- additional information caching is not supported.
613 * \li	#ISC_R_NOMEMORY
614 * \li	Any error that dns_acache_setentry() can return.
615 */
616
617isc_result_t
618dns_rdataset_putadditional(dns_acache_t *acache,
619			   dns_rdataset_t *rdataset,
620			   dns_rdatasetadditional_t type,
621			   dns_rdatatype_t qtype);
622/*%<
623 * Discard cached additional information stored in the DB node for a particular
624 * 'rdataset.'  See dns_rdataset_getadditional for the semantics of 'type'
625 * and 'qtype'.
626 *
627 * Requires:
628 * \li	'rdataset' is a valid rdataset.
629 * \li	'acache' can be NULL, in which case this function will simply return
630 *	ISC_R_FAILURE.
631 *
632 * Ensures:
633 * \li	See dns_acache_cancelentry().
634 *
635 * Returns:
636 * \li	#ISC_R_SUCCESS
637 * \li	#ISC_R_FAILURE	- additional information caching is not supported.
638 * \li	#ISC_R_NOTFOUND	- the corresponding DB node has not cached additional
639 *			  information for 'rdataset.'
640 */
641
642void
643dns_rdataset_settrust(dns_rdataset_t *rdataset, dns_trust_t trust);
644/*%<
645 * Set the trust of the 'rdataset' to trust in any in the backing database.
646 * The local trust level of 'rdataset' is also set.
647 */
648
649void
650dns_rdataset_expire(dns_rdataset_t *rdataset);
651/*%<
652 * Mark the rdataset to be expired in the backing database.
653 */
654
655void
656dns_rdataset_trimttl(dns_rdataset_t *rdataset, dns_rdataset_t *sigrdataset,
657		     dns_rdata_rrsig_t *rrsig, isc_stdtime_t now,
658		     isc_boolean_t acceptexpired);
659/*%<
660 * Trim the ttl of 'rdataset' and 'sigrdataset' so that they will expire
661 * at or before 'rrsig->expiretime'.  If 'acceptexpired' is true and the
662 * signature has expired or will expire in the next 120 seconds, limit
663 * the ttl to be no more than 120 seconds.
664 *
665 * The ttl is further limited by the original ttl as stored in 'rrsig'
666 * and the original ttl values of 'rdataset' and 'sigrdataset'.
667 *
668 * Requires:
669 * \li	'rdataset' is a valid rdataset.
670 * \li	'sigrdataset' is a valid rdataset.
671 * \li	'rrsig' is non NULL.
672 */
673
674const char *
675dns_trust_totext(dns_trust_t trust);
676/*
677 * Display trust in textual form.
678 */
679
680ISC_LANG_ENDDECLS
681
682#endif /* DNS_RDATASET_H */
683