xref: /minix/external/bsd/bind/dist/lib/dns/zt.c (revision fb9c64b2)
1 /*	$NetBSD: zt.c,v 1.8 2015/07/08 17:28:59 christos Exp $	*/
2 
3 /*
4  * Copyright (C) 2004-2007, 2011-2015  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 
42 struct 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 
60 static void
61 auto_detach(void *, void *);
62 
63 static isc_result_t
64 load(dns_zone_t *zone, void *uap);
65 
66 static isc_result_t
67 asyncload(dns_zone_t *zone, void *callback);
68 
69 static isc_result_t
70 loadnew(dns_zone_t *zone, void *uap);
71 
72 static isc_result_t
73 freezezones(dns_zone_t *zone, void *uap);
74 
75 static isc_result_t
76 doneloading(dns_zt_t *zt, dns_zone_t *zone, isc_task_t *task);
77 
78 isc_result_t
79 dns_zt_create(isc_mem_t *mctx, dns_rdataclass_t rdclass, dns_zt_t **ztp) {
80 	dns_zt_t *zt;
81 	isc_result_t result;
82 
83 	REQUIRE(ztp != NULL && *ztp == NULL);
84 
85 	zt = isc_mem_get(mctx, sizeof(*zt));
86 	if (zt == NULL)
87 		return (ISC_R_NOMEMORY);
88 
89 	zt->table = NULL;
90 	result = dns_rbt_create(mctx, auto_detach, zt, &zt->table);
91 	if (result != ISC_R_SUCCESS)
92 		goto cleanup_zt;
93 
94 	result = isc_rwlock_init(&zt->rwlock, 0, 0);
95 	if (result != ISC_R_SUCCESS)
96 		goto cleanup_rbt;
97 
98 	zt->mctx = NULL;
99 	isc_mem_attach(mctx, &zt->mctx);
100 	zt->references = 1;
101 	zt->flush = ISC_FALSE;
102 	zt->rdclass = rdclass;
103 	zt->magic = ZTMAGIC;
104 	zt->loaddone = NULL;
105 	zt->loaddone_arg = NULL;
106 	zt->loads_pending = 0;
107 	*ztp = zt;
108 
109 	return (ISC_R_SUCCESS);
110 
111    cleanup_rbt:
112 	dns_rbt_destroy(&zt->table);
113 
114    cleanup_zt:
115 	isc_mem_put(mctx, zt, sizeof(*zt));
116 
117 	return (result);
118 }
119 
120 isc_result_t
121 dns_zt_mount(dns_zt_t *zt, dns_zone_t *zone) {
122 	isc_result_t result;
123 	dns_zone_t *dummy = NULL;
124 	dns_name_t *name;
125 
126 	REQUIRE(VALID_ZT(zt));
127 
128 	name = dns_zone_getorigin(zone);
129 
130 	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
131 
132 	result = dns_rbt_addname(zt->table, name, zone);
133 	if (result == ISC_R_SUCCESS)
134 		dns_zone_attach(zone, &dummy);
135 
136 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
137 
138 	return (result);
139 }
140 
141 isc_result_t
142 dns_zt_unmount(dns_zt_t *zt, dns_zone_t *zone) {
143 	isc_result_t result;
144 	dns_name_t *name;
145 
146 	REQUIRE(VALID_ZT(zt));
147 
148 	name = dns_zone_getorigin(zone);
149 
150 	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
151 
152 	result = dns_rbt_deletename(zt->table, name, ISC_FALSE);
153 
154 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
155 
156 	return (result);
157 }
158 
159 isc_result_t
160 dns_zt_find(dns_zt_t *zt, dns_name_t *name, unsigned int options,
161 	    dns_name_t *foundname, dns_zone_t **zonep)
162 {
163 	isc_result_t result;
164 	dns_zone_t *dummy = NULL;
165 	unsigned int rbtoptions = 0;
166 
167 	REQUIRE(VALID_ZT(zt));
168 
169 	if ((options & DNS_ZTFIND_NOEXACT) != 0)
170 		rbtoptions |= DNS_RBTFIND_NOEXACT;
171 
172 	RWLOCK(&zt->rwlock, isc_rwlocktype_read);
173 
174 	result = dns_rbt_findname(zt->table, name, rbtoptions, foundname,
175 				  (void **) (void*)&dummy);
176 	if (result == ISC_R_SUCCESS || result == DNS_R_PARTIALMATCH)
177 		dns_zone_attach(dummy, zonep);
178 
179 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
180 
181 	return (result);
182 }
183 
184 void
185 dns_zt_attach(dns_zt_t *zt, dns_zt_t **ztp) {
186 
187 	REQUIRE(VALID_ZT(zt));
188 	REQUIRE(ztp != NULL && *ztp == NULL);
189 
190 	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
191 
192 	INSIST(zt->references > 0);
193 	zt->references++;
194 	INSIST(zt->references != 0);
195 
196 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
197 
198 	*ztp = zt;
199 }
200 
201 static isc_result_t
202 flush(dns_zone_t *zone, void *uap) {
203 	UNUSED(uap);
204 	return (dns_zone_flush(zone));
205 }
206 
207 static void
208 zt_destroy(dns_zt_t *zt) {
209 	if (zt->flush)
210 		(void)dns_zt_apply(zt, ISC_FALSE, flush, NULL);
211 	dns_rbt_destroy(&zt->table);
212 	isc_rwlock_destroy(&zt->rwlock);
213 	zt->magic = 0;
214 	isc_mem_putanddetach(&zt->mctx, zt, sizeof(*zt));
215 }
216 
217 static void
218 zt_flushanddetach(dns_zt_t **ztp, isc_boolean_t need_flush) {
219 	isc_boolean_t destroy = ISC_FALSE;
220 	dns_zt_t *zt;
221 
222 	REQUIRE(ztp != NULL && VALID_ZT(*ztp));
223 
224 	zt = *ztp;
225 
226 	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
227 
228 	INSIST(zt->references > 0);
229 	zt->references--;
230 	if (zt->references == 0)
231 		destroy = ISC_TRUE;
232 	if (need_flush)
233 		zt->flush = ISC_TRUE;
234 
235 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
236 
237 	if (destroy)
238 		zt_destroy(zt);
239 
240 	*ztp = NULL;
241 }
242 
243 void
244 dns_zt_flushanddetach(dns_zt_t **ztp) {
245 	zt_flushanddetach(ztp, ISC_TRUE);
246 }
247 
248 void
249 dns_zt_detach(dns_zt_t **ztp) {
250 	zt_flushanddetach(ztp, ISC_FALSE);
251 }
252 
253 isc_result_t
254 dns_zt_load(dns_zt_t *zt, isc_boolean_t stop) {
255 	isc_result_t result;
256 
257 	REQUIRE(VALID_ZT(zt));
258 
259 	RWLOCK(&zt->rwlock, isc_rwlocktype_read);
260 	result = dns_zt_apply(zt, stop, load, NULL);
261 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
262 	return (result);
263 }
264 
265 static isc_result_t
266 load(dns_zone_t *zone, void *uap) {
267 	isc_result_t result;
268 	UNUSED(uap);
269 
270 	result = dns_zone_load(zone);
271 	if (result == DNS_R_CONTINUE || result == DNS_R_UPTODATE)
272 		result = ISC_R_SUCCESS;
273 
274 	return (result);
275 }
276 
277 isc_result_t
278 dns_zt_asyncload(dns_zt_t *zt, dns_zt_allloaded_t alldone, void *arg) {
279 	isc_result_t result;
280 	static dns_zt_zoneloaded_t dl = doneloading;
281 	int pending;
282 
283 	REQUIRE(VALID_ZT(zt));
284 
285 	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
286 
287 	INSIST(zt->loads_pending == 0);
288 	result = dns_zt_apply2(zt, ISC_FALSE, NULL, asyncload, &dl);
289 
290 	pending = zt->loads_pending;
291 	if (pending != 0) {
292 		zt->loaddone = alldone;
293 		zt->loaddone_arg = arg;
294 	}
295 
296 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
297 
298 	if (pending == 0)
299 		alldone(arg);
300 
301 	return (result);
302 }
303 
304 /*
305  * Initiates asynchronous loading of zone 'zone'.  'callback' is a
306  * pointer to a function which will be used to inform the caller when
307  * the zone loading is complete.
308  */
309 static isc_result_t
310 asyncload(dns_zone_t *zone, void *callback) {
311 	isc_result_t result;
312 	dns_zt_zoneloaded_t *loaded = callback;
313 	dns_zt_t *zt;
314 
315 	REQUIRE(zone != NULL);
316 	zt = dns_zone_getview(zone)->zonetable;
317 	INSIST(VALID_ZT(zt));
318 
319 	INSIST(zt->references > 0);
320 	zt->references++;
321 	zt->loads_pending++;
322 
323 	result = dns_zone_asyncload(zone, *loaded, zt);
324 	if (result != ISC_R_SUCCESS) {
325 		zt->references--;
326 		zt->loads_pending--;
327 		INSIST(zt->references > 0);
328 	}
329 	return (ISC_R_SUCCESS);
330 }
331 
332 isc_result_t
333 dns_zt_loadnew(dns_zt_t *zt, isc_boolean_t stop) {
334 	isc_result_t result;
335 
336 	REQUIRE(VALID_ZT(zt));
337 
338 	RWLOCK(&zt->rwlock, isc_rwlocktype_read);
339 	result = dns_zt_apply(zt, stop, loadnew, NULL);
340 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
341 	return (result);
342 }
343 
344 static isc_result_t
345 loadnew(dns_zone_t *zone, void *uap) {
346 	isc_result_t result;
347 	UNUSED(uap);
348 
349 	result = dns_zone_loadnew(zone);
350 	if (result == DNS_R_CONTINUE || result == DNS_R_UPTODATE ||
351 	    result == DNS_R_DYNAMIC)
352 		result = ISC_R_SUCCESS;
353 	return (result);
354 }
355 
356 isc_result_t
357 dns_zt_freezezones(dns_zt_t *zt, isc_boolean_t freeze) {
358 	isc_result_t result, tresult;
359 
360 	REQUIRE(VALID_ZT(zt));
361 
362 	RWLOCK(&zt->rwlock, isc_rwlocktype_read);
363 	result = dns_zt_apply2(zt, ISC_FALSE, &tresult, freezezones, &freeze);
364 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_read);
365 	if (tresult == ISC_R_NOTFOUND)
366 		tresult = ISC_R_SUCCESS;
367 	return ((result == ISC_R_SUCCESS) ? tresult : result);
368 }
369 
370 static isc_result_t
371 freezezones(dns_zone_t *zone, void *uap) {
372 	isc_boolean_t freeze = *(isc_boolean_t *)uap;
373 	isc_boolean_t frozen;
374 	isc_result_t result = ISC_R_SUCCESS;
375 	char classstr[DNS_RDATACLASS_FORMATSIZE];
376 	char zonename[DNS_NAME_FORMATSIZE];
377 	dns_zone_t *raw = NULL;
378 	dns_view_t *view;
379 	const char *vname;
380 	const char *sep;
381 	int level;
382 
383 	dns_zone_getraw(zone, &raw);
384 	if (raw != NULL)
385 		zone = raw;
386 	if (dns_zone_gettype(zone) != dns_zone_master) {
387 		if (raw != NULL)
388 			dns_zone_detach(&raw);
389 		return (ISC_R_SUCCESS);
390 	}
391 	if (!dns_zone_isdynamic(zone, ISC_TRUE)) {
392 		if (raw != NULL)
393 			dns_zone_detach(&raw);
394 		return (ISC_R_SUCCESS);
395 	}
396 
397 	frozen = dns_zone_getupdatedisabled(zone);
398 	if (freeze) {
399 		if (frozen)
400 			result = DNS_R_FROZEN;
401 		if (result == ISC_R_SUCCESS)
402 			result = dns_zone_flush(zone);
403 		if (result == ISC_R_SUCCESS)
404 			dns_zone_setupdatedisabled(zone, freeze);
405 	} else {
406 		if (frozen) {
407 			result = dns_zone_loadandthaw(zone);
408 			if (result == DNS_R_CONTINUE ||
409 			    result == DNS_R_UPTODATE)
410 				result = ISC_R_SUCCESS;
411 		}
412 	}
413 	view = dns_zone_getview(zone);
414 	if (strcmp(view->name, "_bind") == 0 ||
415 	    strcmp(view->name, "_default") == 0)
416 	{
417 		vname = "";
418 		sep = "";
419 	} else {
420 		vname = view->name;
421 		sep = " ";
422 	}
423 	dns_rdataclass_format(dns_zone_getclass(zone), classstr,
424 			      sizeof(classstr));
425 	dns_name_format(dns_zone_getorigin(zone), zonename, sizeof(zonename));
426 	level = (result != ISC_R_SUCCESS) ? ISC_LOG_ERROR : ISC_LOG_DEBUG(1);
427 	isc_log_write(dns_lctx, DNS_LOGCATEGORY_GENERAL, DNS_LOGMODULE_ZONE,
428 		      level, "%s zone '%s/%s'%s%s: %s",
429 		      freeze ? "freezing" : "thawing",
430 		      zonename, classstr, sep, vname,
431 		      isc_result_totext(result));
432 	if (raw != NULL)
433 		dns_zone_detach(&raw);
434 	return (result);
435 }
436 
437 isc_result_t
438 dns_zt_apply(dns_zt_t *zt, isc_boolean_t stop,
439 	     isc_result_t (*action)(dns_zone_t *, void *), void *uap)
440 {
441 	return (dns_zt_apply2(zt, stop, NULL, action, uap));
442 }
443 
444 isc_result_t
445 dns_zt_apply2(dns_zt_t *zt, isc_boolean_t stop, isc_result_t *sub,
446 	      isc_result_t (*action)(dns_zone_t *, void *), void *uap)
447 {
448 	dns_rbtnode_t *node;
449 	dns_rbtnodechain_t chain;
450 	isc_result_t result, tresult = ISC_R_SUCCESS;
451 	dns_zone_t *zone;
452 
453 	REQUIRE(VALID_ZT(zt));
454 	REQUIRE(action != NULL);
455 
456 	dns_rbtnodechain_init(&chain, zt->mctx);
457 	result = dns_rbtnodechain_first(&chain, zt->table, NULL, NULL);
458 	if (result == ISC_R_NOTFOUND) {
459 		/*
460 		 * The tree is empty.
461 		 */
462 		tresult = result;
463 		result = ISC_R_NOMORE;
464 	}
465 	while (result == DNS_R_NEWORIGIN || result == ISC_R_SUCCESS) {
466 		result = dns_rbtnodechain_current(&chain, NULL, NULL,
467 						  &node);
468 		if (result == ISC_R_SUCCESS) {
469 			zone = node->data;
470 			if (zone != NULL)
471 				result = (action)(zone, uap);
472 			if (result != ISC_R_SUCCESS && stop) {
473 				tresult = result;
474 				goto cleanup;	/* don't break */
475 			} else if (result != ISC_R_SUCCESS &&
476 				   tresult == ISC_R_SUCCESS)
477 				tresult = result;
478 		}
479 		result = dns_rbtnodechain_next(&chain, NULL, NULL);
480 	}
481 	if (result == ISC_R_NOMORE)
482 		result = ISC_R_SUCCESS;
483 
484  cleanup:
485 	dns_rbtnodechain_invalidate(&chain);
486 	if (sub != NULL)
487 		*sub = tresult;
488 
489 	return (result);
490 }
491 
492 /*
493  * Decrement the loads_pending counter; when counter reaches
494  * zero, call the loaddone callback that was initially set by
495  * dns_zt_asyncload().
496  */
497 static isc_result_t
498 doneloading(dns_zt_t *zt, dns_zone_t *zone, isc_task_t *task) {
499 	isc_boolean_t destroy = ISC_FALSE;
500 	dns_zt_allloaded_t alldone = NULL;
501 	void *arg = NULL;
502 
503 	UNUSED(zone);
504 	UNUSED(task);
505 
506 	REQUIRE(VALID_ZT(zt));
507 
508 	RWLOCK(&zt->rwlock, isc_rwlocktype_write);
509 	INSIST(zt->loads_pending != 0);
510 	INSIST(zt->references != 0);
511 	zt->references--;
512 	if (zt->references == 0)
513 		destroy = ISC_TRUE;
514 	zt->loads_pending--;
515 	if (zt->loads_pending == 0) {
516 		alldone = zt->loaddone;
517 		arg = zt->loaddone_arg;
518 		zt->loaddone = NULL;
519 		zt->loaddone_arg = NULL;
520 	}
521 	RWUNLOCK(&zt->rwlock, isc_rwlocktype_write);
522 
523 	if (alldone != NULL)
524 		alldone(arg);
525 
526 	if (destroy)
527 		zt_destroy(zt);
528 
529 	return (ISC_R_SUCCESS);
530 }
531 
532 /***
533  *** Private
534  ***/
535 
536 static void
537 auto_detach(void *data, void *arg) {
538 	dns_zone_t *zone = data;
539 
540 	UNUSED(arg);
541 	dns_zone_detach(&zone);
542 }
543