1/*	$NetBSD: zt.c,v 1.3.4.2 2012/12/15 05:40:00 riz Exp $	*/
2
3/*
4 * Copyright (C) 2004-2007, 2011, 2012  Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (C) 1999-2002  Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and/or distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
13 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
17 * PERFORMANCE OF THIS SOFTWARE.
18 */
19
20/* Id */
21
22/*! \file */
23
24#include <config.h>
25
26#include <isc/file.h>
27#include <isc/magic.h>
28#include <isc/mem.h>
29#include <isc/string.h>
30#include <isc/task.h>
31#include <isc/util.h>
32
33#include <dns/log.h>
34#include <dns/name.h>
35#include <dns/rbt.h>
36#include <dns/rdataclass.h>
37#include <dns/result.h>
38#include <dns/view.h>
39#include <dns/zone.h>
40#include <dns/zt.h>
41
42struct dns_zt {
43	/* Unlocked. */
44	unsigned int		magic;
45	isc_mem_t		*mctx;
46	dns_rdataclass_t	rdclass;
47	isc_rwlock_t		rwlock;
48	dns_zt_allloaded_t	loaddone;
49	void *			loaddone_arg;
50	/* Locked by lock. */
51	isc_boolean_t		flush;
52	isc_uint32_t		references;
53	unsigned int		loads_pending;
54	dns_rbt_t		*table;
55};
56
57#define ZTMAGIC			ISC_MAGIC('Z', 'T', 'b', 'l')
58#define VALID_ZT(zt) 		ISC_MAGIC_VALID(zt, ZTMAGIC)
59
60static void
61auto_detach(void *, void *);
62
63static isc_result_t
64load(dns_zone_t *zone, void *uap);
65
66static isc_result_t
67asyncload(dns_zone_t *zone, void *callback);
68
69static isc_result_t
70loadnew(dns_zone_t *zone, void *uap);
71
72static isc_result_t
73freezezones(dns_zone_t *zone, void *uap);
74
75static isc_result_t
76doneloading(dns_zt_t *zt, dns_zone_t *zone, isc_task_t *task);
77
78isc_result_t
79dns_zt_create(isc_mem_t *mctx, dns_rdataclass_t rdclass, dns_zt_t **ztp)
80{
81	dns_zt_t *zt;
82	isc_result_t result;
83
84	REQUIRE(ztp != NULL && *ztp == NULL);
85
86	zt = isc_mem_get(mctx, sizeof(*zt));
87	if (zt == NULL)
88		return (ISC_R_NOMEMORY);
89
90	zt->table = NULL;
91	result = dns_rbt_create(mctx, auto_detach, zt, &zt->table);
92	if (result != ISC_R_SUCCESS)
93		goto cleanup_zt;
94
95	result = isc_rwlock_init(&zt->rwlock, 0, 0);
96	if (result != ISC_R_SUCCESS)
97		goto cleanup_rbt;
98
99	zt->mctx = NULL;
100	isc_mem_attach(mctx, &zt->mctx);
101	zt->references = 1;
102	zt->flush = ISC_FALSE;
103	zt->rdclass = rdclass;
104	zt->magic = ZTMAGIC;
105	zt->loaddone = NULL;
106	zt->loaddone_arg = NULL;
107	zt->loads_pending = 0;
108	*ztp = zt;
109
110	return (ISC_R_SUCCESS);
111
112   cleanup_rbt:
113	dns_rbt_destroy(&zt->table);
114
115   cleanup_zt:
116	isc_mem_put(mctx, zt, sizeof(*zt));
117
118	return (result);
119}
120
121isc_result_t
122dns_zt_mount(dns_zt_t *zt, dns_zone_t *zone) {
123	isc_result_t result;
124	dns_zone_t *dummy = NULL;
125	dns_name_t *name;
126
127	REQUIRE(VALID_ZT(zt));
128
129	name = dns_zone_getorigin(zone);
130
131	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
132
133	result = dns_rbt_addname(zt->table, name, zone);
134	if (result == ISC_R_SUCCESS)
135		dns_zone_attach(zone, &dummy);
136
137	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
138
139	return (result);
140}
141
142isc_result_t
143dns_zt_unmount(dns_zt_t *zt, dns_zone_t *zone) {
144	isc_result_t result;
145	dns_name_t *name;
146
147	REQUIRE(VALID_ZT(zt));
148
149	name = dns_zone_getorigin(zone);
150
151	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
152
153	result = dns_rbt_deletename(zt->table, name, ISC_FALSE);
154
155	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
156
157	return (result);
158}
159
160isc_result_t
161dns_zt_find(dns_zt_t *zt, dns_name_t *name, unsigned int options,
162	    dns_name_t *foundname, dns_zone_t **zonep)
163{
164	isc_result_t result;
165	dns_zone_t *dummy = NULL;
166	unsigned int rbtoptions = 0;
167
168	REQUIRE(VALID_ZT(zt));
169
170	if ((options & DNS_ZTFIND_NOEXACT) != 0)
171		rbtoptions |= DNS_RBTFIND_NOEXACT;
172
173	RWLOCK(&zt->rwlock, isc_rwlocktype_read);
174
175	result = dns_rbt_findname(zt->table, name, rbtoptions, foundname,
176				  (void **) (void*)&dummy);
177	if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH)
178		dns_zone_attach(dummy, zonep);
179
180	RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
181
182	return (result);
183}
184
185void
186dns_zt_attach(dns_zt_t *zt, dns_zt_t **ztp) {
187
188	REQUIRE(VALID_ZT(zt));
189	REQUIRE(ztp != NULL && *ztp == NULL);
190
191	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
192
193	INSIST(zt->references > 0);
194	zt->references++;
195	INSIST(zt->references != 0);
196
197	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
198
199	*ztp = zt;
200}
201
202static isc_result_t
203flush(dns_zone_t *zone, void *uap) {
204	UNUSED(uap);
205	return (dns_zone_flush(zone));
206}
207
208static void
209zt_destroy(dns_zt_t *zt) {
210	if (zt->flush)
211		(void)dns_zt_apply(zt, ISC_FALSE, flush, NULL);
212	dns_rbt_destroy(&zt->table);
213	isc_rwlock_destroy(&zt->rwlock);
214	zt->magic = 0;
215	isc_mem_putanddetach(&zt->mctx, zt, sizeof(*zt));
216}
217
218static void
219zt_flushanddetach(dns_zt_t **ztp, isc_boolean_t need_flush) {
220	isc_boolean_t destroy = ISC_FALSE;
221	dns_zt_t *zt;
222
223	REQUIRE(ztp != NULL && VALID_ZT(*ztp));
224
225	zt = *ztp;
226
227	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
228
229	INSIST(zt->references > 0);
230	zt->references--;
231	if (zt->references == 0)
232		destroy = ISC_TRUE;
233	if (need_flush)
234		zt->flush = ISC_TRUE;
235
236	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
237
238	if (destroy)
239		zt_destroy(zt);
240
241	*ztp = NULL;
242}
243
244void
245dns_zt_flushanddetach(dns_zt_t **ztp) {
246	zt_flushanddetach(ztp, ISC_TRUE);
247}
248
249void
250dns_zt_detach(dns_zt_t **ztp) {
251	zt_flushanddetach(ztp, ISC_FALSE);
252}
253
254isc_result_t
255dns_zt_load(dns_zt_t *zt, isc_boolean_t stop) {
256	isc_result_t result;
257
258	REQUIRE(VALID_ZT(zt));
259
260	RWLOCK(&zt->rwlock, isc_rwlocktype_read);
261	result = dns_zt_apply(zt, stop, load, NULL);
262	RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
263	return (result);
264}
265
266static isc_result_t
267load(dns_zone_t *zone, void *uap) {
268	isc_result_t result;
269	UNUSED(uap);
270
271	result = dns_zone_load(zone);
272	if (result == DNS_R_CONTINUE || result == DNS_R_UPTODATE)
273		result = ISC_R_SUCCESS;
274
275	return (result);
276}
277
278isc_result_t
279dns_zt_asyncload(dns_zt_t *zt, dns_zt_allloaded_t alldone, void *arg) {
280	isc_result_t result;
281	static dns_zt_zoneloaded_t dl = doneloading;
282	int pending;
283
284	REQUIRE(VALID_ZT(zt));
285
286	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
287
288	INSIST(zt->loads_pending == 0);
289	result = dns_zt_apply2(zt, ISC_FALSE, NULL, asyncload, &dl);
290
291	pending = zt->loads_pending;
292	if (pending != 0) {
293		zt->loaddone = alldone;
294		zt->loaddone_arg = arg;
295	}
296
297	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
298
299	if (pending == 0)
300		alldone(arg);
301
302	return (result);
303}
304
305/*
306 * Initiates asynchronous loading of zone 'zone'.  'callback' is a
307 * pointer to a function which will be used to inform the caller when
308 * the zone loading is complete.
309 */
310static isc_result_t
311asyncload(dns_zone_t *zone, void *callback) {
312	isc_result_t result;
313	dns_zt_zoneloaded_t *loaded = callback;
314	dns_zt_t *zt;
315
316	REQUIRE(zone != NULL);
317	zt = dns_zone_getview(zone)->zonetable;
318	INSIST(VALID_ZT(zt));
319
320	result = dns_zone_asyncload(zone, *loaded, zt);
321	if (result == ISC_R_SUCCESS) {
322		INSIST(zt->references > 0);
323		zt->references++;
324		INSIST(zt->references != 0);
325		zt->loads_pending++;
326	}
327	return (ISC_R_SUCCESS);
328}
329
330isc_result_t
331dns_zt_loadnew(dns_zt_t *zt, isc_boolean_t stop) {
332	isc_result_t result;
333
334	REQUIRE(VALID_ZT(zt));
335
336	RWLOCK(&zt->rwlock, isc_rwlocktype_read);
337	result = dns_zt_apply(zt, stop, loadnew, NULL);
338	RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
339	return (result);
340}
341
342static isc_result_t
343loadnew(dns_zone_t *zone, void *uap) {
344	isc_result_t result;
345	UNUSED(uap);
346
347	result = dns_zone_loadnew(zone);
348	if (result == DNS_R_CONTINUE || result == DNS_R_UPTODATE ||
349	    result == DNS_R_DYNAMIC)
350		result = ISC_R_SUCCESS;
351	return (result);
352}
353
354isc_result_t
355dns_zt_freezezones(dns_zt_t *zt, isc_boolean_t freeze) {
356	isc_result_t result, tresult;
357
358	REQUIRE(VALID_ZT(zt));
359
360	RWLOCK(&zt->rwlock, isc_rwlocktype_read);
361	result = dns_zt_apply2(zt, ISC_FALSE, &tresult, freezezones, &freeze);
362	RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
363	if (tresult == ISC_R_NOTFOUND)
364		tresult = ISC_R_SUCCESS;
365	return ((result == ISC_R_SUCCESS) ? tresult : result);
366}
367
368static isc_result_t
369freezezones(dns_zone_t *zone, void *uap) {
370	isc_boolean_t freeze = *(isc_boolean_t *)uap;
371	isc_boolean_t frozen;
372	isc_result_t result = ISC_R_SUCCESS;
373	char classstr[DNS_RDATACLASS_FORMATSIZE];
374	char zonename[DNS_NAME_FORMATSIZE];
375	dns_zone_t *raw = NULL;
376	dns_view_t *view;
377	const char *vname;
378	const char *sep;
379	int level;
380
381	dns_zone_getraw(zone, &raw);
382	if (raw != NULL)
383		zone = raw;
384	if (dns_zone_gettype(zone) != dns_zone_master) {
385		if (raw != NULL)
386			dns_zone_detach(&raw);
387		return (ISC_R_SUCCESS);
388	}
389	if (!dns_zone_isdynamic(zone, ISC_TRUE)) {
390		if (raw != NULL)
391			dns_zone_detach(&raw);
392		return (ISC_R_SUCCESS);
393	}
394
395	frozen = dns_zone_getupdatedisabled(zone);
396	if (freeze) {
397		if (frozen)
398			result = DNS_R_FROZEN;
399		if (result == ISC_R_SUCCESS)
400			result = dns_zone_flush(zone);
401	} else {
402		if (frozen) {
403			result = dns_zone_load(zone);
404			if (result == DNS_R_CONTINUE ||
405			    result == DNS_R_UPTODATE)
406				result = ISC_R_SUCCESS;
407		}
408	}
409	if (result == ISC_R_SUCCESS)
410		dns_zone_setupdatedisabled(zone, freeze);
411	view = dns_zone_getview(zone);
412	if (strcmp(view->name, "_bind") == 0 ||
413	    strcmp(view->name, "_default") == 0)
414	{
415		vname = "";
416		sep = "";
417	} else {
418		vname = view->name;
419		sep = " ";
420	}
421	dns_rdataclass_format(dns_zone_getclass(zone), classstr,
422			      sizeof(classstr));
423	dns_name_format(dns_zone_getorigin(zone), zonename, sizeof(zonename));
424	level = (result != ISC_R_SUCCESS) ? ISC_LOG_ERROR : ISC_LOG_DEBUG(1);
425	isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_ZONE,
426		      level, "%s zone '%s/%s'%s%s: %s",
427		      freeze ? "freezing" : "thawing",
428		      zonename, classstr, sep, vname,
429		      isc_result_totext(result));
430	if (raw != NULL)
431		dns_zone_detach(&raw);
432	return (result);
433}
434
435isc_result_t
436dns_zt_apply(dns_zt_t *zt, isc_boolean_t stop,
437	     isc_result_t (*action)(dns_zone_t *, void *), void *uap)
438{
439	return (dns_zt_apply2(zt, stop, NULL, action, uap));
440}
441
442isc_result_t
443dns_zt_apply2(dns_zt_t *zt, isc_boolean_t stop, isc_result_t *sub,
444	      isc_result_t (*action)(dns_zone_t *, void *), void *uap)
445{
446	dns_rbtnode_t *node;
447	dns_rbtnodechain_t chain;
448	isc_result_t result, tresult = ISC_R_SUCCESS;
449	dns_zone_t *zone;
450
451	REQUIRE(VALID_ZT(zt));
452	REQUIRE(action != NULL);
453
454	dns_rbtnodechain_init(&chain, zt->mctx);
455	result = dns_rbtnodechain_first(&chain, zt->table, NULL, NULL);
456	if (result == ISC_R_NOTFOUND) {
457		/*
458		 * The tree is empty.
459		 */
460		tresult = result;
461		result = ISC_R_NOMORE;
462	}
463	while (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) {
464		result = dns_rbtnodechain_current(&chain, NULL, NULL,
465						  &node);
466		if (result == ISC_R_SUCCESS) {
467			zone = node->data;
468			if (zone != NULL)
469				result = (action)(zone, uap);
470			if (result != ISC_R_SUCCESS && stop) {
471				tresult = result;
472				goto cleanup;	/* don't break */
473			} else if (result != ISC_R_SUCCESS &&
474				   tresult == ISC_R_SUCCESS)
475				tresult = result;
476		}
477		result = dns_rbtnodechain_next(&chain, NULL, NULL);
478	}
479	if (result == ISC_R_NOMORE)
480		result = ISC_R_SUCCESS;
481
482 cleanup:
483	dns_rbtnodechain_invalidate(&chain);
484	if (sub != NULL)
485		*sub = tresult;
486
487	return (result);
488}
489
490/*
491 * Decrement the loads_pending counter; when counter reaches
492 * zero, call the loaddone callback that was initially set by
493 * dns_zt_asyncload().
494 */
495static isc_result_t
496doneloading(dns_zt_t *zt, dns_zone_t *zone, isc_task_t *task) {
497	isc_boolean_t destroy = ISC_FALSE;
498	dns_zt_allloaded_t alldone = NULL;
499	void *arg = NULL;
500
501	UNUSED(zone);
502	UNUSED(task);
503
504	REQUIRE(VALID_ZT(zt));
505
506	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
507	INSIST(zt->loads_pending != 0);
508	INSIST(zt->references != 0);
509	zt->references--;
510	if (zt->references == 0)
511		destroy = ISC_TRUE;
512	zt->loads_pending--;
513	if (zt->loads_pending == 0) {
514		alldone = zt->loaddone;
515		arg = zt->loaddone_arg;
516		zt->loaddone = NULL;
517		zt->loaddone_arg = NULL;
518	}
519	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
520
521	if (alldone != NULL)
522		alldone(arg);
523
524	if (destroy)
525		zt_destroy(zt);
526
527	return (ISC_R_SUCCESS);
528}
529
530/***
531 *** Private
532 ***/
533
534static void
535auto_detach(void *data, void *arg) {
536	dns_zone_t *zone = data;
537
538	UNUSED(arg);
539
540	dns_zone_detach(&zone);
541}
542