2 * Copyright (C) 2004, 2006 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2000, 2001, 2003 Internet Software Consortium.
5 * Permission to use, copy, modify, and 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.
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.
18 /* $Id: lookup.c,v 1.9.12.7 2006/01/04 23:50:20 marka Exp $ */
23 #include <isc/netaddr.h>
24 #include <isc/string.h> /* Required for HP/UX (and others?) */
29 #include <dns/events.h>
30 #include <dns/lookup.h>
31 #include <dns/rdata.h>
32 #include <dns/rdataset.h>
33 #include <dns/rdatastruct.h>
34 #include <dns/resolver.h>
35 #include <dns/result.h>
49 dns_lookupevent_t * event;
51 unsigned int restarts;
52 isc_boolean_t canceled;
53 dns_rdataset_t rdataset;
54 dns_rdataset_t sigrdataset;
57 #define LOOKUP_MAGIC ISC_MAGIC('l', 'o', 'o', 'k')
58 #define VALID_LOOKUP(l) ISC_MAGIC_VALID((l), LOOKUP_MAGIC)
60 #define MAX_RESTARTS 16
62 static void lookup_find(dns_lookup_t *lookup, dns_fetchevent_t *event);
65 fetch_done(isc_task_t *task, isc_event_t *event) {
66 dns_lookup_t *lookup = event->ev_arg;
67 dns_fetchevent_t *fevent;
70 REQUIRE(event->ev_type == DNS_EVENT_FETCHDONE);
71 REQUIRE(VALID_LOOKUP(lookup));
72 REQUIRE(lookup->task == task);
73 fevent = (dns_fetchevent_t *)event;
74 REQUIRE(fevent->fetch == lookup->fetch);
76 lookup_find(lookup, fevent);
79 static inline isc_result_t
80 start_fetch(dns_lookup_t *lookup) {
84 * The caller must be holding the lookup's lock.
87 REQUIRE(lookup->fetch == NULL);
89 result = dns_resolver_createfetch(lookup->view->resolver,
90 dns_fixedname_name(&lookup->name),
93 lookup->task, fetch_done, lookup,
102 build_event(dns_lookup_t *lookup) {
103 dns_name_t *name = NULL;
104 dns_rdataset_t *rdataset = NULL;
105 dns_rdataset_t *sigrdataset = NULL;
108 name = isc_mem_get(lookup->mctx, sizeof(dns_name_t));
110 result = ISC_R_NOMEMORY;
113 dns_name_init(name, NULL);
114 result = dns_name_dup(dns_fixedname_name(&lookup->name),
116 if (result != ISC_R_SUCCESS)
119 if (dns_rdataset_isassociated(&lookup->rdataset)) {
120 rdataset = isc_mem_get(lookup->mctx, sizeof(dns_rdataset_t));
121 if (rdataset == NULL) {
122 result = ISC_R_NOMEMORY;
125 dns_rdataset_init(rdataset);
126 dns_rdataset_clone(&lookup->rdataset, rdataset);
129 if (dns_rdataset_isassociated(&lookup->sigrdataset)) {
130 sigrdataset = isc_mem_get(lookup->mctx,
131 sizeof(dns_rdataset_t));
132 if (sigrdataset == NULL) {
133 result = ISC_R_NOMEMORY;
136 dns_rdataset_init(sigrdataset);
137 dns_rdataset_clone(&lookup->sigrdataset, sigrdataset);
140 lookup->event->name = name;
141 lookup->event->rdataset = rdataset;
142 lookup->event->sigrdataset = sigrdataset;
144 return (ISC_R_SUCCESS);
148 if (dns_name_dynamic(name))
149 dns_name_free(name, lookup->mctx);
150 isc_mem_put(lookup->mctx, name, sizeof(dns_name_t));
152 if (rdataset != NULL) {
153 if (dns_rdataset_isassociated(rdataset))
154 dns_rdataset_disassociate(rdataset);
155 isc_mem_put(lookup->mctx, rdataset, sizeof(dns_rdataset_t));
161 view_find(dns_lookup_t *lookup, dns_name_t *foundname) {
163 dns_name_t *name = dns_fixedname_name(&lookup->name);
164 dns_rdatatype_t type;
166 if (lookup->type == dns_rdatatype_rrsig)
167 type = dns_rdatatype_any;
171 result = dns_view_find(lookup->view, name, type, 0, 0, ISC_FALSE,
172 &lookup->event->db, &lookup->event->node,
173 foundname, &lookup->rdataset,
174 &lookup->sigrdataset);
179 lookup_find(dns_lookup_t *lookup, dns_fetchevent_t *event) {
181 isc_boolean_t want_restart;
182 isc_boolean_t send_event = ISC_FALSE;
183 dns_name_t *name, *fname, *prefix;
184 dns_fixedname_t foundname, fixed;
185 dns_rdata_t rdata = DNS_RDATA_INIT;
186 unsigned int nlabels;
188 dns_namereln_t namereln;
189 dns_rdata_cname_t cname;
190 dns_rdata_dname_t dname;
192 REQUIRE(VALID_LOOKUP(lookup));
196 result = ISC_R_SUCCESS;
197 name = dns_fixedname_name(&lookup->name);
201 want_restart = ISC_FALSE;
203 if (event == NULL && !lookup->canceled) {
204 dns_fixedname_init(&foundname);
205 fname = dns_fixedname_name(&foundname);
206 INSIST(!dns_rdataset_isassociated(&lookup->rdataset));
207 INSIST(!dns_rdataset_isassociated
208 (&lookup->sigrdataset));
209 result = view_find(lookup, fname);
210 if (result == ISC_R_NOTFOUND) {
212 * We don't know anything about the name.
215 if (lookup->event->node != NULL) {
216 INSIST(lookup->event->db != NULL);
217 dns_db_detachnode(lookup->event->db,
218 &lookup->event->node);
220 if (lookup->event->db != NULL)
221 dns_db_detach(&lookup->event->db);
222 result = start_fetch(lookup);
223 if (result != ISC_R_SUCCESS)
224 send_event = ISC_TRUE;
227 } else if (event != NULL) {
228 result = event->result;
229 fname = dns_fixedname_name(&event->foundname);
230 dns_resolver_destroyfetch(&lookup->fetch);
231 INSIST(event->rdataset == &lookup->rdataset);
232 INSIST(event->sigrdataset == &lookup->sigrdataset);
234 fname = NULL; /* Silence compiler warning. */
237 * If we've been canceled, forget about the result.
239 if (lookup->canceled)
240 result = ISC_R_CANCELED;
244 result = build_event(lookup);
245 send_event = ISC_TRUE;
248 if (event->db != NULL)
249 dns_db_attach(event->db, &lookup->event->db);
250 if (event->node != NULL)
251 dns_db_attachnode(lookup->event->db,
253 &lookup->event->node);
257 * Copy the CNAME's target into the lookup's
258 * query name and start over.
260 result = dns_rdataset_first(&lookup->rdataset);
261 if (result != ISC_R_SUCCESS)
263 dns_rdataset_current(&lookup->rdataset, &rdata);
264 result = dns_rdata_tostruct(&rdata, &cname, NULL);
265 dns_rdata_reset(&rdata);
266 if (result != ISC_R_SUCCESS)
268 result = dns_name_copy(&cname.cname, name, NULL);
269 dns_rdata_freestruct(&cname);
270 if (result == ISC_R_SUCCESS)
271 want_restart = ISC_TRUE;
274 namereln = dns_name_fullcompare(name, fname, &order,
276 INSIST(namereln == dns_namereln_subdomain);
278 * Get the target name of the DNAME.
280 result = dns_rdataset_first(&lookup->rdataset);
281 if (result != ISC_R_SUCCESS)
283 dns_rdataset_current(&lookup->rdataset, &rdata);
284 result = dns_rdata_tostruct(&rdata, &dname, NULL);
285 dns_rdata_reset(&rdata);
286 if (result != ISC_R_SUCCESS)
289 * Construct the new query name and start over.
291 dns_fixedname_init(&fixed);
292 prefix = dns_fixedname_name(&fixed);
293 dns_name_split(name, nlabels, prefix, NULL);
294 result = dns_name_concatenate(prefix, &dname.dname,
296 dns_rdata_freestruct(&dname);
297 if (result == ISC_R_SUCCESS)
298 want_restart = ISC_TRUE;
301 send_event = ISC_TRUE;
304 if (dns_rdataset_isassociated(&lookup->rdataset))
305 dns_rdataset_disassociate(&lookup->rdataset);
306 if (dns_rdataset_isassociated(&lookup->sigrdataset))
307 dns_rdataset_disassociate(&lookup->sigrdataset);
311 if (event->node != NULL)
312 dns_db_detachnode(event->db, &event->node);
313 if (event->db != NULL)
314 dns_db_detach(&event->db);
315 isc_event_free(ISC_EVENT_PTR(&event));
319 * Limit the number of restarts.
321 if (want_restart && lookup->restarts == MAX_RESTARTS) {
322 want_restart = ISC_FALSE;
323 result = ISC_R_QUOTA;
324 send_event = ISC_TRUE;
327 } while (want_restart);
330 lookup->event->result = result;
331 lookup->event->ev_sender = lookup;
332 isc_task_sendanddetach(&lookup->task,
333 (isc_event_t **)&lookup->event);
334 dns_view_detach(&lookup->view);
337 UNLOCK(&lookup->lock);
341 levent_destroy(isc_event_t *event) {
342 dns_lookupevent_t *levent;
345 REQUIRE(event->ev_type == DNS_EVENT_LOOKUPDONE);
346 mctx = event->ev_destroy_arg;
347 levent = (dns_lookupevent_t *)event;
349 if (levent->name != NULL) {
350 if (dns_name_dynamic(levent->name))
351 dns_name_free(levent->name, mctx);
352 isc_mem_put(mctx, levent->name, sizeof(dns_name_t));
354 if (levent->rdataset != NULL) {
355 dns_rdataset_disassociate(levent->rdataset);
356 isc_mem_put(mctx, levent->rdataset, sizeof(dns_rdataset_t));
358 if (levent->sigrdataset != NULL) {
359 dns_rdataset_disassociate(levent->sigrdataset);
360 isc_mem_put(mctx, levent->sigrdataset, sizeof(dns_rdataset_t));
362 if (levent->node != NULL)
363 dns_db_detachnode(levent->db, &levent->node);
364 if (levent->db != NULL)
365 dns_db_detach(&levent->db);
366 isc_mem_put(mctx, event, event->ev_size);
371 dns_lookup_create(isc_mem_t *mctx, dns_name_t *name, dns_rdatatype_t type,
372 dns_view_t *view, unsigned int options, isc_task_t *task,
373 isc_taskaction_t action, void *arg, dns_lookup_t **lookupp)
376 dns_lookup_t *lookup;
379 lookup = isc_mem_get(mctx, sizeof(*lookup));
381 return (ISC_R_NOMEMORY);
383 lookup->options = options;
385 ievent = isc_event_allocate(mctx, lookup, DNS_EVENT_LOOKUPDONE,
386 action, arg, sizeof(*lookup->event));
387 if (ievent == NULL) {
388 result = ISC_R_NOMEMORY;
391 lookup->event = (dns_lookupevent_t *)ievent;
392 lookup->event->ev_destroy = levent_destroy;
393 lookup->event->ev_destroy_arg = mctx;
394 lookup->event->result = ISC_R_FAILURE;
395 lookup->event->name = NULL;
396 lookup->event->rdataset = NULL;
397 lookup->event->sigrdataset = NULL;
398 lookup->event->db = NULL;
399 lookup->event->node = NULL;
402 isc_task_attach(task, &lookup->task);
404 result = isc_mutex_init(&lookup->lock);
405 if (result != ISC_R_SUCCESS)
408 dns_fixedname_init(&lookup->name);
410 result = dns_name_copy(name, dns_fixedname_name(&lookup->name), NULL);
411 if (result != ISC_R_SUCCESS)
416 dns_view_attach(view, &lookup->view);
417 lookup->fetch = NULL;
418 lookup->restarts = 0;
419 lookup->canceled = ISC_FALSE;
420 dns_rdataset_init(&lookup->rdataset);
421 dns_rdataset_init(&lookup->sigrdataset);
422 lookup->magic = LOOKUP_MAGIC;
426 lookup_find(lookup, NULL);
428 return (ISC_R_SUCCESS);
431 DESTROYLOCK(&lookup->lock);
434 ievent = (isc_event_t *)lookup->event;
435 isc_event_free(&ievent);
436 lookup->event = NULL;
438 isc_task_detach(&lookup->task);
441 isc_mem_put(mctx, lookup, sizeof(*lookup));
447 dns_lookup_cancel(dns_lookup_t *lookup) {
448 REQUIRE(VALID_LOOKUP(lookup));
452 if (!lookup->canceled) {
453 lookup->canceled = ISC_TRUE;
454 if (lookup->fetch != NULL) {
455 INSIST(lookup->view != NULL);
456 dns_resolver_cancelfetch(lookup->fetch);
460 UNLOCK(&lookup->lock);
464 dns_lookup_destroy(dns_lookup_t **lookupp) {
465 dns_lookup_t *lookup;
467 REQUIRE(lookupp != NULL);
469 REQUIRE(VALID_LOOKUP(lookup));
470 REQUIRE(lookup->event == NULL);
471 REQUIRE(lookup->task == NULL);
472 REQUIRE(lookup->view == NULL);
473 if (dns_rdataset_isassociated(&lookup->rdataset))
474 dns_rdataset_disassociate(&lookup->rdataset);
475 if (dns_rdataset_isassociated(&lookup->sigrdataset))
476 dns_rdataset_disassociate(&lookup->sigrdataset);
478 DESTROYLOCK(&lookup->lock);
480 isc_mem_put(lookup->mctx, lookup, sizeof(*lookup));