1 /*
2 * iterator/iterator.c - iterative resolver DNS query response module
3 *
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36 /**
37 * \file
38 *
39 * This file contains a module that performs recursive iterative DNS query
40 * processing.
41 */
42
43 #include "config.h"
44 #include "iterator/iterator.h"
45 #include "iterator/iter_utils.h"
46 #include "iterator/iter_hints.h"
47 #include "iterator/iter_fwd.h"
48 #include "iterator/iter_donotq.h"
49 #include "iterator/iter_delegpt.h"
50 #include "iterator/iter_resptype.h"
51 #include "iterator/iter_scrub.h"
52 #include "iterator/iter_priv.h"
53 #include "validator/val_neg.h"
54 #include "services/cache/dns.h"
55 #include "services/cache/infra.h"
56 #include "services/authzone.h"
57 #include "util/module.h"
58 #include "util/netevent.h"
59 #include "util/net_help.h"
60 #include "util/regional.h"
61 #include "util/data/dname.h"
62 #include "util/data/msgencode.h"
63 #include "util/fptr_wlist.h"
64 #include "util/config_file.h"
65 #include "util/random.h"
66 #include "sldns/rrdef.h"
67 #include "sldns/wire2str.h"
68 #include "sldns/str2wire.h"
69 #include "sldns/parseutil.h"
70 #include "sldns/sbuffer.h"
71
72 /* in msec */
73 int UNKNOWN_SERVER_NICENESS = 376;
74 /* in msec */
75 int USEFUL_SERVER_TOP_TIMEOUT = 120000;
76 /* Equals USEFUL_SERVER_TOP_TIMEOUT*4 */
77 int BLACKLIST_PENALTY = (120000*4);
78
79 static void target_count_increase_nx(struct iter_qstate* iq, int num);
80
81 int
iter_init(struct module_env * env,int id)82 iter_init(struct module_env* env, int id)
83 {
84 struct iter_env* iter_env = (struct iter_env*)calloc(1,
85 sizeof(struct iter_env));
86 if(!iter_env) {
87 log_err("malloc failure");
88 return 0;
89 }
90 env->modinfo[id] = (void*)iter_env;
91
92 lock_basic_init(&iter_env->queries_ratelimit_lock);
93 lock_protect(&iter_env->queries_ratelimit_lock,
94 &iter_env->num_queries_ratelimited,
95 sizeof(iter_env->num_queries_ratelimited));
96
97 if(!iter_apply_cfg(iter_env, env->cfg)) {
98 log_err("iterator: could not apply configuration settings.");
99 return 0;
100 }
101
102 return 1;
103 }
104
105 /** delete caps_whitelist element */
106 static void
caps_free(struct rbnode_type * n,void * ATTR_UNUSED (d))107 caps_free(struct rbnode_type* n, void* ATTR_UNUSED(d))
108 {
109 if(n) {
110 free(((struct name_tree_node*)n)->name);
111 free(n);
112 }
113 }
114
115 void
iter_deinit(struct module_env * env,int id)116 iter_deinit(struct module_env* env, int id)
117 {
118 struct iter_env* iter_env;
119 if(!env || !env->modinfo[id])
120 return;
121 iter_env = (struct iter_env*)env->modinfo[id];
122 lock_basic_destroy(&iter_env->queries_ratelimit_lock);
123 free(iter_env->target_fetch_policy);
124 priv_delete(iter_env->priv);
125 donotq_delete(iter_env->donotq);
126 if(iter_env->caps_white) {
127 traverse_postorder(iter_env->caps_white, caps_free, NULL);
128 free(iter_env->caps_white);
129 }
130 free(iter_env);
131 env->modinfo[id] = NULL;
132 }
133
134 /** new query for iterator */
135 static int
iter_new(struct module_qstate * qstate,int id)136 iter_new(struct module_qstate* qstate, int id)
137 {
138 struct iter_qstate* iq = (struct iter_qstate*)regional_alloc(
139 qstate->region, sizeof(struct iter_qstate));
140 qstate->minfo[id] = iq;
141 if(!iq)
142 return 0;
143 memset(iq, 0, sizeof(*iq));
144 iq->state = INIT_REQUEST_STATE;
145 iq->final_state = FINISHED_STATE;
146 iq->an_prepend_list = NULL;
147 iq->an_prepend_last = NULL;
148 iq->ns_prepend_list = NULL;
149 iq->ns_prepend_last = NULL;
150 iq->dp = NULL;
151 iq->depth = 0;
152 iq->num_target_queries = 0;
153 iq->num_current_queries = 0;
154 iq->query_restart_count = 0;
155 iq->referral_count = 0;
156 iq->sent_count = 0;
157 iq->ratelimit_ok = 0;
158 iq->target_count = NULL;
159 iq->dp_target_count = 0;
160 iq->wait_priming_stub = 0;
161 iq->refetch_glue = 0;
162 iq->dnssec_expected = 0;
163 iq->dnssec_lame_query = 0;
164 iq->chase_flags = qstate->query_flags;
165 /* Start with the (current) qname. */
166 iq->qchase = qstate->qinfo;
167 outbound_list_init(&iq->outlist);
168 iq->minimise_count = 0;
169 iq->timeout_count = 0;
170 if (qstate->env->cfg->qname_minimisation)
171 iq->minimisation_state = INIT_MINIMISE_STATE;
172 else
173 iq->minimisation_state = DONOT_MINIMISE_STATE;
174
175 memset(&iq->qinfo_out, 0, sizeof(struct query_info));
176 return 1;
177 }
178
179 /**
180 * Transition to the next state. This can be used to advance a currently
181 * processing event. It cannot be used to reactivate a forEvent.
182 *
183 * @param iq: iterator query state
184 * @param nextstate The state to transition to.
185 * @return true. This is so this can be called as the return value for the
186 * actual process*State() methods. (Transitioning to the next state
187 * implies further processing).
188 */
189 static int
next_state(struct iter_qstate * iq,enum iter_state nextstate)190 next_state(struct iter_qstate* iq, enum iter_state nextstate)
191 {
192 /* If transitioning to a "response" state, make sure that there is a
193 * response */
194 if(iter_state_is_responsestate(nextstate)) {
195 if(iq->response == NULL) {
196 log_err("transitioning to response state sans "
197 "response.");
198 }
199 }
200 iq->state = nextstate;
201 return 1;
202 }
203
204 /**
205 * Transition an event to its final state. Final states always either return
206 * a result up the module chain, or reactivate a dependent event. Which
207 * final state to transition to is set in the module state for the event when
208 * it was created, and depends on the original purpose of the event.
209 *
210 * The response is stored in the qstate->buf buffer.
211 *
212 * @param iq: iterator query state
213 * @return false. This is so this method can be used as the return value for
214 * the processState methods. (Transitioning to the final state
215 */
216 static int
final_state(struct iter_qstate * iq)217 final_state(struct iter_qstate* iq)
218 {
219 return next_state(iq, iq->final_state);
220 }
221
222 /**
223 * Callback routine to handle errors in parent query states
224 * @param qstate: query state that failed.
225 * @param id: module id.
226 * @param super: super state.
227 */
228 static void
error_supers(struct module_qstate * qstate,int id,struct module_qstate * super)229 error_supers(struct module_qstate* qstate, int id, struct module_qstate* super)
230 {
231 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
232 struct iter_qstate* super_iq = (struct iter_qstate*)super->minfo[id];
233
234 if(qstate->qinfo.qtype == LDNS_RR_TYPE_A ||
235 qstate->qinfo.qtype == LDNS_RR_TYPE_AAAA) {
236 /* mark address as failed. */
237 struct delegpt_ns* dpns = NULL;
238 super_iq->num_target_queries--;
239 if(super_iq->dp)
240 dpns = delegpt_find_ns(super_iq->dp,
241 qstate->qinfo.qname, qstate->qinfo.qname_len);
242 if(!dpns) {
243 /* not interested */
244 /* this can happen, for eg. qname minimisation asked
245 * for an NXDOMAIN to be validated, and used qtype
246 * A for that, and the error of that, the name, is
247 * not listed in super_iq->dp */
248 verbose(VERB_ALGO, "subq error, but not interested");
249 log_query_info(VERB_ALGO, "superq", &super->qinfo);
250 return;
251 } else {
252 /* see if the failure did get (parent-lame) info */
253 if(!cache_fill_missing(super->env, super_iq->qchase.qclass,
254 super->region, super_iq->dp))
255 log_err("out of memory adding missing");
256 }
257 delegpt_mark_neg(dpns, qstate->qinfo.qtype);
258 if((dpns->got4 == 2 || (!ie->supports_ipv4 && !ie->use_nat64)) &&
259 (dpns->got6 == 2 || !ie->supports_ipv6)) {
260 dpns->resolved = 1; /* mark as failed */
261 target_count_increase_nx(super_iq, 1);
262 }
263 }
264 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS) {
265 /* prime failed to get delegation */
266 super_iq->dp = NULL;
267 }
268 /* evaluate targets again */
269 super_iq->state = QUERYTARGETS_STATE;
270 /* super becomes runnable, and will process this change */
271 }
272
273 /**
274 * Return an error to the client
275 * @param qstate: our query state
276 * @param id: module id
277 * @param rcode: error code (DNS errcode).
278 * @return: 0 for use by caller, to make notation easy, like:
279 * return error_response(..).
280 */
281 static int
error_response(struct module_qstate * qstate,int id,int rcode)282 error_response(struct module_qstate* qstate, int id, int rcode)
283 {
284 verbose(VERB_QUERY, "return error response %s",
285 sldns_lookup_by_id(sldns_rcodes, rcode)?
286 sldns_lookup_by_id(sldns_rcodes, rcode)->name:"??");
287 qstate->return_rcode = rcode;
288 qstate->return_msg = NULL;
289 qstate->ext_state[id] = module_finished;
290 return 0;
291 }
292
293 /**
294 * Return an error to the client and cache the error code in the
295 * message cache (so per qname, qtype, qclass).
296 * @param qstate: our query state
297 * @param id: module id
298 * @param rcode: error code (DNS errcode).
299 * @return: 0 for use by caller, to make notation easy, like:
300 * return error_response(..).
301 */
302 static int
error_response_cache(struct module_qstate * qstate,int id,int rcode)303 error_response_cache(struct module_qstate* qstate, int id, int rcode)
304 {
305 struct reply_info err;
306 struct msgreply_entry* msg;
307 if(qstate->no_cache_store) {
308 return error_response(qstate, id, rcode);
309 }
310 if(qstate->prefetch_leeway > NORR_TTL) {
311 verbose(VERB_ALGO, "error response for prefetch in cache");
312 /* attempt to adjust the cache entry prefetch */
313 if(dns_cache_prefetch_adjust(qstate->env, &qstate->qinfo,
314 NORR_TTL, qstate->query_flags))
315 return error_response(qstate, id, rcode);
316 /* if that fails (not in cache), fall through to store err */
317 }
318 if((msg=msg_cache_lookup(qstate->env,
319 qstate->qinfo.qname, qstate->qinfo.qname_len,
320 qstate->qinfo.qtype, qstate->qinfo.qclass,
321 qstate->query_flags, 0,
322 qstate->env->cfg->serve_expired_ttl_reset)) != NULL) {
323 struct reply_info* rep = (struct reply_info*)msg->entry.data;
324 if(qstate->env->cfg->serve_expired &&
325 qstate->env->cfg->serve_expired_ttl_reset && rep &&
326 *qstate->env->now + qstate->env->cfg->serve_expired_ttl
327 > rep->serve_expired_ttl) {
328 verbose(VERB_ALGO, "reset serve-expired-ttl for "
329 "response in cache");
330 rep->serve_expired_ttl = *qstate->env->now +
331 qstate->env->cfg->serve_expired_ttl;
332 }
333 if(rep && (FLAGS_GET_RCODE(rep->flags) ==
334 LDNS_RCODE_NOERROR ||
335 FLAGS_GET_RCODE(rep->flags) ==
336 LDNS_RCODE_NXDOMAIN ||
337 FLAGS_GET_RCODE(rep->flags) ==
338 LDNS_RCODE_YXDOMAIN) &&
339 (qstate->env->cfg->serve_expired ||
340 *qstate->env->now <= rep->ttl)) {
341 /* we have a good entry, don't overwrite */
342 lock_rw_unlock(&msg->entry.lock);
343 return error_response(qstate, id, rcode);
344 }
345 lock_rw_unlock(&msg->entry.lock);
346 /* nothing interesting is cached (already error response or
347 * expired good record when we don't serve expired), so this
348 * servfail cache entry is useful (stops waste of time on this
349 * servfail NORR_TTL) */
350 }
351 /* store in cache */
352 memset(&err, 0, sizeof(err));
353 err.flags = (uint16_t)(BIT_QR | BIT_RA);
354 FLAGS_SET_RCODE(err.flags, rcode);
355 err.qdcount = 1;
356 err.ttl = NORR_TTL;
357 err.prefetch_ttl = PREFETCH_TTL_CALC(err.ttl);
358 err.serve_expired_ttl = NORR_TTL;
359 /* do not waste time trying to validate this servfail */
360 err.security = sec_status_indeterminate;
361 verbose(VERB_ALGO, "store error response in message cache");
362 iter_dns_store(qstate->env, &qstate->qinfo, &err, 0, 0, 0, NULL,
363 qstate->query_flags, qstate->qstarttime);
364 return error_response(qstate, id, rcode);
365 }
366
367 /** check if prepend item is duplicate item */
368 static int
prepend_is_duplicate(struct ub_packed_rrset_key ** sets,size_t to,struct ub_packed_rrset_key * dup)369 prepend_is_duplicate(struct ub_packed_rrset_key** sets, size_t to,
370 struct ub_packed_rrset_key* dup)
371 {
372 size_t i;
373 for(i=0; i<to; i++) {
374 if(sets[i]->rk.type == dup->rk.type &&
375 sets[i]->rk.rrset_class == dup->rk.rrset_class &&
376 sets[i]->rk.dname_len == dup->rk.dname_len &&
377 query_dname_compare(sets[i]->rk.dname, dup->rk.dname)
378 == 0)
379 return 1;
380 }
381 return 0;
382 }
383
384 /** prepend the prepend list in the answer and authority section of dns_msg */
385 static int
iter_prepend(struct iter_qstate * iq,struct dns_msg * msg,struct regional * region)386 iter_prepend(struct iter_qstate* iq, struct dns_msg* msg,
387 struct regional* region)
388 {
389 struct iter_prep_list* p;
390 struct ub_packed_rrset_key** sets;
391 size_t num_an = 0, num_ns = 0;;
392 for(p = iq->an_prepend_list; p; p = p->next)
393 num_an++;
394 for(p = iq->ns_prepend_list; p; p = p->next)
395 num_ns++;
396 if(num_an + num_ns == 0)
397 return 1;
398 verbose(VERB_ALGO, "prepending %d rrsets", (int)num_an + (int)num_ns);
399 if(num_an > RR_COUNT_MAX || num_ns > RR_COUNT_MAX ||
400 msg->rep->rrset_count > RR_COUNT_MAX) return 0; /* overflow */
401 sets = regional_alloc(region, (num_an+num_ns+msg->rep->rrset_count) *
402 sizeof(struct ub_packed_rrset_key*));
403 if(!sets)
404 return 0;
405 /* ANSWER section */
406 num_an = 0;
407 for(p = iq->an_prepend_list; p; p = p->next) {
408 sets[num_an++] = p->rrset;
409 if(ub_packed_rrset_ttl(p->rrset) < msg->rep->ttl)
410 msg->rep->ttl = ub_packed_rrset_ttl(p->rrset);
411 }
412 memcpy(sets+num_an, msg->rep->rrsets, msg->rep->an_numrrsets *
413 sizeof(struct ub_packed_rrset_key*));
414 /* AUTH section */
415 num_ns = 0;
416 for(p = iq->ns_prepend_list; p; p = p->next) {
417 if(prepend_is_duplicate(sets+msg->rep->an_numrrsets+num_an,
418 num_ns, p->rrset) || prepend_is_duplicate(
419 msg->rep->rrsets+msg->rep->an_numrrsets,
420 msg->rep->ns_numrrsets, p->rrset))
421 continue;
422 sets[msg->rep->an_numrrsets + num_an + num_ns++] = p->rrset;
423 if(ub_packed_rrset_ttl(p->rrset) < msg->rep->ttl)
424 msg->rep->ttl = ub_packed_rrset_ttl(p->rrset);
425 }
426 memcpy(sets + num_an + msg->rep->an_numrrsets + num_ns,
427 msg->rep->rrsets + msg->rep->an_numrrsets,
428 (msg->rep->ns_numrrsets + msg->rep->ar_numrrsets) *
429 sizeof(struct ub_packed_rrset_key*));
430
431 /* NXDOMAIN rcode can stay if we prepended DNAME/CNAMEs, because
432 * this is what recursors should give. */
433 msg->rep->rrset_count += num_an + num_ns;
434 msg->rep->an_numrrsets += num_an;
435 msg->rep->ns_numrrsets += num_ns;
436 msg->rep->rrsets = sets;
437 return 1;
438 }
439
440 /**
441 * Find rrset in ANSWER prepend list.
442 * to avoid duplicate DNAMEs when a DNAME is traversed twice.
443 * @param iq: iterator query state.
444 * @param rrset: rrset to add.
445 * @return false if not found
446 */
447 static int
iter_find_rrset_in_prepend_answer(struct iter_qstate * iq,struct ub_packed_rrset_key * rrset)448 iter_find_rrset_in_prepend_answer(struct iter_qstate* iq,
449 struct ub_packed_rrset_key* rrset)
450 {
451 struct iter_prep_list* p = iq->an_prepend_list;
452 while(p) {
453 if(ub_rrset_compare(p->rrset, rrset) == 0 &&
454 rrsetdata_equal((struct packed_rrset_data*)p->rrset
455 ->entry.data, (struct packed_rrset_data*)rrset
456 ->entry.data))
457 return 1;
458 p = p->next;
459 }
460 return 0;
461 }
462
463 /**
464 * Add rrset to ANSWER prepend list
465 * @param qstate: query state.
466 * @param iq: iterator query state.
467 * @param rrset: rrset to add.
468 * @return false on failure (malloc).
469 */
470 static int
iter_add_prepend_answer(struct module_qstate * qstate,struct iter_qstate * iq,struct ub_packed_rrset_key * rrset)471 iter_add_prepend_answer(struct module_qstate* qstate, struct iter_qstate* iq,
472 struct ub_packed_rrset_key* rrset)
473 {
474 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
475 qstate->region, sizeof(struct iter_prep_list));
476 if(!p)
477 return 0;
478 p->rrset = rrset;
479 p->next = NULL;
480 /* add at end */
481 if(iq->an_prepend_last)
482 iq->an_prepend_last->next = p;
483 else iq->an_prepend_list = p;
484 iq->an_prepend_last = p;
485 return 1;
486 }
487
488 /**
489 * Add rrset to AUTHORITY prepend list
490 * @param qstate: query state.
491 * @param iq: iterator query state.
492 * @param rrset: rrset to add.
493 * @return false on failure (malloc).
494 */
495 static int
iter_add_prepend_auth(struct module_qstate * qstate,struct iter_qstate * iq,struct ub_packed_rrset_key * rrset)496 iter_add_prepend_auth(struct module_qstate* qstate, struct iter_qstate* iq,
497 struct ub_packed_rrset_key* rrset)
498 {
499 struct iter_prep_list* p = (struct iter_prep_list*)regional_alloc(
500 qstate->region, sizeof(struct iter_prep_list));
501 if(!p)
502 return 0;
503 p->rrset = rrset;
504 p->next = NULL;
505 /* add at end */
506 if(iq->ns_prepend_last)
507 iq->ns_prepend_last->next = p;
508 else iq->ns_prepend_list = p;
509 iq->ns_prepend_last = p;
510 return 1;
511 }
512
513 /**
514 * Given a CNAME response (defined as a response containing a CNAME or DNAME
515 * that does not answer the request), process the response, modifying the
516 * state as necessary. This follows the CNAME/DNAME chain and returns the
517 * final query name.
518 *
519 * sets the new query name, after following the CNAME/DNAME chain.
520 * @param qstate: query state.
521 * @param iq: iterator query state.
522 * @param msg: the response.
523 * @param mname: returned target new query name.
524 * @param mname_len: length of mname.
525 * @return false on (malloc) error.
526 */
527 static int
handle_cname_response(struct module_qstate * qstate,struct iter_qstate * iq,struct dns_msg * msg,uint8_t ** mname,size_t * mname_len)528 handle_cname_response(struct module_qstate* qstate, struct iter_qstate* iq,
529 struct dns_msg* msg, uint8_t** mname, size_t* mname_len)
530 {
531 size_t i;
532 /* Start with the (current) qname. */
533 *mname = iq->qchase.qname;
534 *mname_len = iq->qchase.qname_len;
535
536 /* Iterate over the ANSWER rrsets in order, looking for CNAMEs and
537 * DNAMES. */
538 for(i=0; i<msg->rep->an_numrrsets; i++) {
539 struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
540 /* If there is a (relevant) DNAME, add it to the list.
541 * We always expect there to be CNAME that was generated
542 * by this DNAME following, so we don't process the DNAME
543 * directly. */
544 if(ntohs(r->rk.type) == LDNS_RR_TYPE_DNAME &&
545 dname_strict_subdomain_c(*mname, r->rk.dname) &&
546 !iter_find_rrset_in_prepend_answer(iq, r)) {
547 if(!iter_add_prepend_answer(qstate, iq, r))
548 return 0;
549 continue;
550 }
551
552 if(ntohs(r->rk.type) == LDNS_RR_TYPE_CNAME &&
553 query_dname_compare(*mname, r->rk.dname) == 0 &&
554 !iter_find_rrset_in_prepend_answer(iq, r)) {
555 /* Add this relevant CNAME rrset to the prepend list.*/
556 if(!iter_add_prepend_answer(qstate, iq, r))
557 return 0;
558 get_cname_target(r, mname, mname_len);
559 }
560
561 /* Other rrsets in the section are ignored. */
562 }
563 /* add authority rrsets to authority prepend, for wildcarded CNAMEs */
564 for(i=msg->rep->an_numrrsets; i<msg->rep->an_numrrsets +
565 msg->rep->ns_numrrsets; i++) {
566 struct ub_packed_rrset_key* r = msg->rep->rrsets[i];
567 /* only add NSEC/NSEC3, as they may be needed for validation */
568 if(ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC ||
569 ntohs(r->rk.type) == LDNS_RR_TYPE_NSEC3) {
570 if(!iter_add_prepend_auth(qstate, iq, r))
571 return 0;
572 }
573 }
574 return 1;
575 }
576
577 /** fill fail address for later recovery */
578 static void
fill_fail_addr(struct iter_qstate * iq,struct sockaddr_storage * addr,socklen_t addrlen)579 fill_fail_addr(struct iter_qstate* iq, struct sockaddr_storage* addr,
580 socklen_t addrlen)
581 {
582 if(addrlen == 0) {
583 iq->fail_addr_type = 0;
584 return;
585 }
586 if(((struct sockaddr_in*)addr)->sin_family == AF_INET) {
587 iq->fail_addr_type = 4;
588 memcpy(&iq->fail_addr.in,
589 &((struct sockaddr_in*)addr)->sin_addr,
590 sizeof(iq->fail_addr.in));
591 }
592 #ifdef AF_INET6
593 else if(((struct sockaddr_in*)addr)->sin_family == AF_INET6) {
594 iq->fail_addr_type = 6;
595 memcpy(&iq->fail_addr.in6,
596 &((struct sockaddr_in6*)addr)->sin6_addr,
597 sizeof(iq->fail_addr.in6));
598 }
599 #endif
600 else {
601 iq->fail_addr_type = 0;
602 }
603 }
604
605 /** print fail addr to string */
606 static void
print_fail_addr(struct iter_qstate * iq,char * buf,size_t len)607 print_fail_addr(struct iter_qstate* iq, char* buf, size_t len)
608 {
609 if(iq->fail_addr_type == 4) {
610 if(inet_ntop(AF_INET, &iq->fail_addr.in, buf,
611 (socklen_t)len) == 0)
612 (void)strlcpy(buf, "(inet_ntop error)", len);
613 }
614 #ifdef AF_INET6
615 else if(iq->fail_addr_type == 6) {
616 if(inet_ntop(AF_INET6, &iq->fail_addr.in6, buf,
617 (socklen_t)len) == 0)
618 (void)strlcpy(buf, "(inet_ntop error)", len);
619 }
620 #endif
621 else
622 (void)strlcpy(buf, "", len);
623 }
624
625 /** add response specific error information for log servfail */
626 static void
errinf_reply(struct module_qstate * qstate,struct iter_qstate * iq)627 errinf_reply(struct module_qstate* qstate, struct iter_qstate* iq)
628 {
629 if(qstate->env->cfg->val_log_level < 2 && !qstate->env->cfg->log_servfail)
630 return;
631 if((qstate->reply && qstate->reply->remote_addrlen != 0) ||
632 (iq->fail_addr_type != 0)) {
633 char from[256], frm[512];
634 if(qstate->reply && qstate->reply->remote_addrlen != 0)
635 addr_to_str(&qstate->reply->remote_addr,
636 qstate->reply->remote_addrlen, from,
637 sizeof(from));
638 else
639 print_fail_addr(iq, from, sizeof(from));
640 snprintf(frm, sizeof(frm), "from %s", from);
641 errinf(qstate, frm);
642 }
643 if(iq->scrub_failures || iq->parse_failures) {
644 if(iq->scrub_failures)
645 errinf(qstate, "upstream response failed scrub");
646 if(iq->parse_failures)
647 errinf(qstate, "could not parse upstream response");
648 } else if(iq->response == NULL && iq->timeout_count != 0) {
649 errinf(qstate, "upstream server timeout");
650 } else if(iq->response == NULL) {
651 errinf(qstate, "no server to query");
652 if(iq->dp) {
653 if(iq->dp->target_list == NULL)
654 errinf(qstate, "no addresses for nameservers");
655 else errinf(qstate, "nameserver addresses not usable");
656 if(iq->dp->nslist == NULL)
657 errinf(qstate, "have no nameserver names");
658 if(iq->dp->bogus)
659 errinf(qstate, "NS record was dnssec bogus");
660 }
661 }
662 if(iq->response && iq->response->rep) {
663 if(FLAGS_GET_RCODE(iq->response->rep->flags) != 0) {
664 char rcode[256], rc[32];
665 (void)sldns_wire2str_rcode_buf(
666 FLAGS_GET_RCODE(iq->response->rep->flags),
667 rc, sizeof(rc));
668 snprintf(rcode, sizeof(rcode), "got %s", rc);
669 errinf(qstate, rcode);
670 } else {
671 /* rcode NOERROR */
672 if(iq->response->rep->an_numrrsets == 0) {
673 errinf(qstate, "nodata answer");
674 }
675 }
676 }
677 }
678
679 /** see if last resort is possible - does config allow queries to parent */
680 static int
can_have_last_resort(struct module_env * env,uint8_t * nm,size_t nmlen,uint16_t qclass,struct delegpt ** retdp)681 can_have_last_resort(struct module_env* env, uint8_t* nm, size_t nmlen,
682 uint16_t qclass, struct delegpt** retdp)
683 {
684 struct delegpt* fwddp;
685 struct iter_hints_stub* stub;
686 int labs = dname_count_labels(nm);
687 /* do not process a last resort (the parent side) if a stub
688 * or forward is configured, because we do not want to go 'above'
689 * the configured servers */
690 if(!dname_is_root(nm) && (stub = (struct iter_hints_stub*)
691 name_tree_find(&env->hints->tree, nm, nmlen, labs, qclass)) &&
692 /* has_parent side is turned off for stub_first, where we
693 * are allowed to go to the parent */
694 stub->dp->has_parent_side_NS) {
695 if(retdp) *retdp = stub->dp;
696 return 0;
697 }
698 if((fwddp = forwards_find(env->fwds, nm, qclass)) &&
699 /* has_parent_side is turned off for forward_first, where
700 * we are allowed to go to the parent */
701 fwddp->has_parent_side_NS) {
702 if(retdp) *retdp = fwddp;
703 return 0;
704 }
705 return 1;
706 }
707
708 /** see if target name is caps-for-id whitelisted */
709 static int
is_caps_whitelisted(struct iter_env * ie,struct iter_qstate * iq)710 is_caps_whitelisted(struct iter_env* ie, struct iter_qstate* iq)
711 {
712 if(!ie->caps_white) return 0; /* no whitelist, or no capsforid */
713 return name_tree_lookup(ie->caps_white, iq->qchase.qname,
714 iq->qchase.qname_len, dname_count_labels(iq->qchase.qname),
715 iq->qchase.qclass) != NULL;
716 }
717
718 /**
719 * Create target count structure for this query. This is always explicitly
720 * created for the parent query.
721 */
722 static void
target_count_create(struct iter_qstate * iq)723 target_count_create(struct iter_qstate* iq)
724 {
725 if(!iq->target_count) {
726 iq->target_count = (int*)calloc(TARGET_COUNT_MAX, sizeof(int));
727 /* if calloc fails we simply do not track this number */
728 if(iq->target_count) {
729 iq->target_count[TARGET_COUNT_REF] = 1;
730 iq->nxns_dp = (uint8_t**)calloc(1, sizeof(uint8_t*));
731 }
732 }
733 }
734
735 static void
target_count_increase(struct iter_qstate * iq,int num)736 target_count_increase(struct iter_qstate* iq, int num)
737 {
738 target_count_create(iq);
739 if(iq->target_count)
740 iq->target_count[TARGET_COUNT_QUERIES] += num;
741 iq->dp_target_count++;
742 }
743
744 static void
target_count_increase_nx(struct iter_qstate * iq,int num)745 target_count_increase_nx(struct iter_qstate* iq, int num)
746 {
747 target_count_create(iq);
748 if(iq->target_count)
749 iq->target_count[TARGET_COUNT_NX] += num;
750 }
751
752 /**
753 * Generate a subrequest.
754 * Generate a local request event. Local events are tied to this module, and
755 * have a corresponding (first tier) event that is waiting for this event to
756 * resolve to continue.
757 *
758 * @param qname The query name for this request.
759 * @param qnamelen length of qname
760 * @param qtype The query type for this request.
761 * @param qclass The query class for this request.
762 * @param qstate The event that is generating this event.
763 * @param id: module id.
764 * @param iq: The iterator state that is generating this event.
765 * @param initial_state The initial response state (normally this
766 * is QUERY_RESP_STATE, unless it is known that the request won't
767 * need iterative processing
768 * @param finalstate The final state for the response to this request.
769 * @param subq_ret: if newly allocated, the subquerystate, or NULL if it does
770 * not need initialisation.
771 * @param v: if true, validation is done on the subquery.
772 * @param detached: true if this qstate should not attach to the subquery
773 * @return false on error (malloc).
774 */
775 static int
generate_sub_request(uint8_t * qname,size_t qnamelen,uint16_t qtype,uint16_t qclass,struct module_qstate * qstate,int id,struct iter_qstate * iq,enum iter_state initial_state,enum iter_state finalstate,struct module_qstate ** subq_ret,int v,int detached)776 generate_sub_request(uint8_t* qname, size_t qnamelen, uint16_t qtype,
777 uint16_t qclass, struct module_qstate* qstate, int id,
778 struct iter_qstate* iq, enum iter_state initial_state,
779 enum iter_state finalstate, struct module_qstate** subq_ret, int v,
780 int detached)
781 {
782 struct module_qstate* subq = NULL;
783 struct iter_qstate* subiq = NULL;
784 uint16_t qflags = 0; /* OPCODE QUERY, no flags */
785 struct query_info qinf;
786 int prime = (finalstate == PRIME_RESP_STATE)?1:0;
787 int valrec = 0;
788 qinf.qname = qname;
789 qinf.qname_len = qnamelen;
790 qinf.qtype = qtype;
791 qinf.qclass = qclass;
792 qinf.local_alias = NULL;
793
794 /* RD should be set only when sending the query back through the INIT
795 * state. */
796 if(initial_state == INIT_REQUEST_STATE)
797 qflags |= BIT_RD;
798 /* We set the CD flag so we can send this through the "head" of
799 * the resolution chain, which might have a validator. We are
800 * uninterested in validating things not on the direct resolution
801 * path. */
802 if(!v) {
803 qflags |= BIT_CD;
804 valrec = 1;
805 }
806
807 if(detached) {
808 struct mesh_state* sub = NULL;
809 fptr_ok(fptr_whitelist_modenv_add_sub(
810 qstate->env->add_sub));
811 if(!(*qstate->env->add_sub)(qstate, &qinf,
812 qflags, prime, valrec, &subq, &sub)){
813 return 0;
814 }
815 }
816 else {
817 /* attach subquery, lookup existing or make a new one */
818 fptr_ok(fptr_whitelist_modenv_attach_sub(
819 qstate->env->attach_sub));
820 if(!(*qstate->env->attach_sub)(qstate, &qinf, qflags, prime,
821 valrec, &subq)) {
822 return 0;
823 }
824 }
825 *subq_ret = subq;
826 if(subq) {
827 /* initialise the new subquery */
828 subq->curmod = id;
829 subq->ext_state[id] = module_state_initial;
830 subq->minfo[id] = regional_alloc(subq->region,
831 sizeof(struct iter_qstate));
832 if(!subq->minfo[id]) {
833 log_err("init subq: out of memory");
834 fptr_ok(fptr_whitelist_modenv_kill_sub(
835 qstate->env->kill_sub));
836 (*qstate->env->kill_sub)(subq);
837 return 0;
838 }
839 subiq = (struct iter_qstate*)subq->minfo[id];
840 memset(subiq, 0, sizeof(*subiq));
841 subiq->num_target_queries = 0;
842 target_count_create(iq);
843 subiq->target_count = iq->target_count;
844 if(iq->target_count) {
845 iq->target_count[TARGET_COUNT_REF] ++; /* extra reference */
846 subiq->nxns_dp = iq->nxns_dp;
847 }
848 subiq->dp_target_count = 0;
849 subiq->num_current_queries = 0;
850 subiq->depth = iq->depth+1;
851 outbound_list_init(&subiq->outlist);
852 subiq->state = initial_state;
853 subiq->final_state = finalstate;
854 subiq->qchase = subq->qinfo;
855 subiq->chase_flags = subq->query_flags;
856 subiq->refetch_glue = 0;
857 if(qstate->env->cfg->qname_minimisation)
858 subiq->minimisation_state = INIT_MINIMISE_STATE;
859 else
860 subiq->minimisation_state = DONOT_MINIMISE_STATE;
861 memset(&subiq->qinfo_out, 0, sizeof(struct query_info));
862 }
863 return 1;
864 }
865
866 /**
867 * Generate and send a root priming request.
868 * @param qstate: the qtstate that triggered the need to prime.
869 * @param iq: iterator query state.
870 * @param id: module id.
871 * @param qclass: the class to prime.
872 * @return 0 on failure
873 */
874 static int
prime_root(struct module_qstate * qstate,struct iter_qstate * iq,int id,uint16_t qclass)875 prime_root(struct module_qstate* qstate, struct iter_qstate* iq, int id,
876 uint16_t qclass)
877 {
878 struct delegpt* dp;
879 struct module_qstate* subq;
880 verbose(VERB_DETAIL, "priming . %s NS",
881 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)?
882 sldns_lookup_by_id(sldns_rr_classes, (int)qclass)->name:"??");
883 dp = hints_lookup_root(qstate->env->hints, qclass);
884 if(!dp) {
885 verbose(VERB_ALGO, "Cannot prime due to lack of hints");
886 return 0;
887 }
888 /* Priming requests start at the QUERYTARGETS state, skipping
889 * the normal INIT state logic (which would cause an infloop). */
890 if(!generate_sub_request((uint8_t*)"\000", 1, LDNS_RR_TYPE_NS,
891 qclass, qstate, id, iq, QUERYTARGETS_STATE, PRIME_RESP_STATE,
892 &subq, 0, 0)) {
893 verbose(VERB_ALGO, "could not prime root");
894 return 0;
895 }
896 if(subq) {
897 struct iter_qstate* subiq =
898 (struct iter_qstate*)subq->minfo[id];
899 /* Set the initial delegation point to the hint.
900 * copy dp, it is now part of the root prime query.
901 * dp was part of in the fixed hints structure. */
902 subiq->dp = delegpt_copy(dp, subq->region);
903 if(!subiq->dp) {
904 log_err("out of memory priming root, copydp");
905 fptr_ok(fptr_whitelist_modenv_kill_sub(
906 qstate->env->kill_sub));
907 (*qstate->env->kill_sub)(subq);
908 return 0;
909 }
910 /* there should not be any target queries. */
911 subiq->num_target_queries = 0;
912 subiq->dnssec_expected = iter_indicates_dnssec(
913 qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
914 }
915
916 /* this module stops, our submodule starts, and does the query. */
917 qstate->ext_state[id] = module_wait_subquery;
918 return 1;
919 }
920
921 /**
922 * Generate and process a stub priming request. This method tests for the
923 * need to prime a stub zone, so it is safe to call for every request.
924 *
925 * @param qstate: the qtstate that triggered the need to prime.
926 * @param iq: iterator query state.
927 * @param id: module id.
928 * @param qname: request name.
929 * @param qclass: request class.
930 * @return true if a priming subrequest was made, false if not. The will only
931 * issue a priming request if it detects an unprimed stub.
932 * Uses value of 2 to signal during stub-prime in root-prime situation
933 * that a noprime-stub is available and resolution can continue.
934 */
935 static int
prime_stub(struct module_qstate * qstate,struct iter_qstate * iq,int id,uint8_t * qname,uint16_t qclass)936 prime_stub(struct module_qstate* qstate, struct iter_qstate* iq, int id,
937 uint8_t* qname, uint16_t qclass)
938 {
939 /* Lookup the stub hint. This will return null if the stub doesn't
940 * need to be re-primed. */
941 struct iter_hints_stub* stub;
942 struct delegpt* stub_dp;
943 struct module_qstate* subq;
944
945 if(!qname) return 0;
946 stub = hints_lookup_stub(qstate->env->hints, qname, qclass, iq->dp);
947 /* The stub (if there is one) does not need priming. */
948 if(!stub)
949 return 0;
950 stub_dp = stub->dp;
951 /* if we have an auth_zone dp, and stub is equal, don't prime stub
952 * yet, unless we want to fallback and avoid the auth_zone */
953 if(!iq->auth_zone_avoid && iq->dp && iq->dp->auth_dp &&
954 query_dname_compare(iq->dp->name, stub_dp->name) == 0)
955 return 0;
956
957 /* is it a noprime stub (always use) */
958 if(stub->noprime) {
959 int r = 0;
960 if(iq->dp == NULL) r = 2;
961 /* copy the dp out of the fixed hints structure, so that
962 * it can be changed when servicing this query */
963 iq->dp = delegpt_copy(stub_dp, qstate->region);
964 if(!iq->dp) {
965 log_err("out of memory priming stub");
966 errinf(qstate, "malloc failure, priming stub");
967 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
968 return 1; /* return 1 to make module stop, with error */
969 }
970 log_nametypeclass(VERB_DETAIL, "use stub", stub_dp->name,
971 LDNS_RR_TYPE_NS, qclass);
972 return r;
973 }
974
975 /* Otherwise, we need to (re)prime the stub. */
976 log_nametypeclass(VERB_DETAIL, "priming stub", stub_dp->name,
977 LDNS_RR_TYPE_NS, qclass);
978
979 /* Stub priming events start at the QUERYTARGETS state to avoid the
980 * redundant INIT state processing. */
981 if(!generate_sub_request(stub_dp->name, stub_dp->namelen,
982 LDNS_RR_TYPE_NS, qclass, qstate, id, iq,
983 QUERYTARGETS_STATE, PRIME_RESP_STATE, &subq, 0, 0)) {
984 verbose(VERB_ALGO, "could not prime stub");
985 errinf(qstate, "could not generate lookup for stub prime");
986 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
987 return 1; /* return 1 to make module stop, with error */
988 }
989 if(subq) {
990 struct iter_qstate* subiq =
991 (struct iter_qstate*)subq->minfo[id];
992
993 /* Set the initial delegation point to the hint. */
994 /* make copy to avoid use of stub dp by different qs/threads */
995 subiq->dp = delegpt_copy(stub_dp, subq->region);
996 if(!subiq->dp) {
997 log_err("out of memory priming stub, copydp");
998 fptr_ok(fptr_whitelist_modenv_kill_sub(
999 qstate->env->kill_sub));
1000 (*qstate->env->kill_sub)(subq);
1001 errinf(qstate, "malloc failure, in stub prime");
1002 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1003 return 1; /* return 1 to make module stop, with error */
1004 }
1005 /* there should not be any target queries -- although there
1006 * wouldn't be anyway, since stub hints never have
1007 * missing targets. */
1008 subiq->num_target_queries = 0;
1009 subiq->wait_priming_stub = 1;
1010 subiq->dnssec_expected = iter_indicates_dnssec(
1011 qstate->env, subiq->dp, NULL, subq->qinfo.qclass);
1012 }
1013
1014 /* this module stops, our submodule starts, and does the query. */
1015 qstate->ext_state[id] = module_wait_subquery;
1016 return 1;
1017 }
1018
1019 /**
1020 * Generate a delegation point for an auth zone (unless cached dp is better)
1021 * false on alloc failure.
1022 */
1023 static int
auth_zone_delegpt(struct module_qstate * qstate,struct iter_qstate * iq,uint8_t * delname,size_t delnamelen)1024 auth_zone_delegpt(struct module_qstate* qstate, struct iter_qstate* iq,
1025 uint8_t* delname, size_t delnamelen)
1026 {
1027 struct auth_zone* z;
1028 if(iq->auth_zone_avoid)
1029 return 1;
1030 if(!delname) {
1031 delname = iq->qchase.qname;
1032 delnamelen = iq->qchase.qname_len;
1033 }
1034 lock_rw_rdlock(&qstate->env->auth_zones->lock);
1035 z = auth_zones_find_zone(qstate->env->auth_zones, delname, delnamelen,
1036 qstate->qinfo.qclass);
1037 if(!z) {
1038 lock_rw_unlock(&qstate->env->auth_zones->lock);
1039 return 1;
1040 }
1041 lock_rw_rdlock(&z->lock);
1042 lock_rw_unlock(&qstate->env->auth_zones->lock);
1043 if(z->for_upstream) {
1044 if(iq->dp && query_dname_compare(z->name, iq->dp->name) == 0
1045 && iq->dp->auth_dp && qstate->blacklist &&
1046 z->fallback_enabled) {
1047 /* cache is blacklisted and fallback, and we
1048 * already have an auth_zone dp */
1049 if(verbosity>=VERB_ALGO) {
1050 char buf[255+1];
1051 dname_str(z->name, buf);
1052 verbose(VERB_ALGO, "auth_zone %s "
1053 "fallback because cache blacklisted",
1054 buf);
1055 }
1056 lock_rw_unlock(&z->lock);
1057 iq->dp = NULL;
1058 return 1;
1059 }
1060 if(iq->dp==NULL || dname_subdomain_c(z->name, iq->dp->name)) {
1061 struct delegpt* dp;
1062 if(qstate->blacklist && z->fallback_enabled) {
1063 /* cache is blacklisted because of a DNSSEC
1064 * validation failure, and the zone allows
1065 * fallback to the internet, query there. */
1066 if(verbosity>=VERB_ALGO) {
1067 char buf[255+1];
1068 dname_str(z->name, buf);
1069 verbose(VERB_ALGO, "auth_zone %s "
1070 "fallback because cache blacklisted",
1071 buf);
1072 }
1073 lock_rw_unlock(&z->lock);
1074 return 1;
1075 }
1076 dp = (struct delegpt*)regional_alloc_zero(
1077 qstate->region, sizeof(*dp));
1078 if(!dp) {
1079 log_err("alloc failure");
1080 if(z->fallback_enabled) {
1081 lock_rw_unlock(&z->lock);
1082 return 1; /* just fallback */
1083 }
1084 lock_rw_unlock(&z->lock);
1085 errinf(qstate, "malloc failure");
1086 return 0;
1087 }
1088 dp->name = regional_alloc_init(qstate->region,
1089 z->name, z->namelen);
1090 if(!dp->name) {
1091 log_err("alloc failure");
1092 if(z->fallback_enabled) {
1093 lock_rw_unlock(&z->lock);
1094 return 1; /* just fallback */
1095 }
1096 lock_rw_unlock(&z->lock);
1097 errinf(qstate, "malloc failure");
1098 return 0;
1099 }
1100 dp->namelen = z->namelen;
1101 dp->namelabs = z->namelabs;
1102 dp->auth_dp = 1;
1103 iq->dp = dp;
1104 }
1105 }
1106
1107 lock_rw_unlock(&z->lock);
1108 return 1;
1109 }
1110
1111 /**
1112 * Generate A and AAAA checks for glue that is in-zone for the referral
1113 * we just got to obtain authoritative information on the addresses.
1114 *
1115 * @param qstate: the qtstate that triggered the need to prime.
1116 * @param iq: iterator query state.
1117 * @param id: module id.
1118 */
1119 static void
generate_a_aaaa_check(struct module_qstate * qstate,struct iter_qstate * iq,int id)1120 generate_a_aaaa_check(struct module_qstate* qstate, struct iter_qstate* iq,
1121 int id)
1122 {
1123 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
1124 struct module_qstate* subq;
1125 size_t i;
1126 struct reply_info* rep = iq->response->rep;
1127 struct ub_packed_rrset_key* s;
1128 log_assert(iq->dp);
1129
1130 if(iq->depth == ie->max_dependency_depth)
1131 return;
1132 /* walk through additional, and check if in-zone,
1133 * only relevant A, AAAA are left after scrub anyway */
1134 for(i=rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
1135 s = rep->rrsets[i];
1136 /* check *ALL* addresses that are transmitted in additional*/
1137 /* is it an address ? */
1138 if( !(ntohs(s->rk.type)==LDNS_RR_TYPE_A ||
1139 ntohs(s->rk.type)==LDNS_RR_TYPE_AAAA)) {
1140 continue;
1141 }
1142 /* is this query the same as the A/AAAA check for it */
1143 if(qstate->qinfo.qtype == ntohs(s->rk.type) &&
1144 qstate->qinfo.qclass == ntohs(s->rk.rrset_class) &&
1145 query_dname_compare(qstate->qinfo.qname,
1146 s->rk.dname)==0 &&
1147 (qstate->query_flags&BIT_RD) &&
1148 !(qstate->query_flags&BIT_CD))
1149 continue;
1150
1151 /* generate subrequest for it */
1152 log_nametypeclass(VERB_ALGO, "schedule addr fetch",
1153 s->rk.dname, ntohs(s->rk.type),
1154 ntohs(s->rk.rrset_class));
1155 if(!generate_sub_request(s->rk.dname, s->rk.dname_len,
1156 ntohs(s->rk.type), ntohs(s->rk.rrset_class),
1157 qstate, id, iq,
1158 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) {
1159 verbose(VERB_ALGO, "could not generate addr check");
1160 return;
1161 }
1162 /* ignore subq - not need for more init */
1163 }
1164 }
1165
1166 /**
1167 * Generate a NS check request to obtain authoritative information
1168 * on an NS rrset.
1169 *
1170 * @param qstate: the qstate that triggered the need to prime.
1171 * @param iq: iterator query state.
1172 * @param id: module id.
1173 */
1174 static void
generate_ns_check(struct module_qstate * qstate,struct iter_qstate * iq,int id)1175 generate_ns_check(struct module_qstate* qstate, struct iter_qstate* iq, int id)
1176 {
1177 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
1178 struct module_qstate* subq;
1179 log_assert(iq->dp);
1180
1181 if(iq->depth == ie->max_dependency_depth)
1182 return;
1183 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen,
1184 iq->qchase.qclass, NULL))
1185 return;
1186 /* is this query the same as the nscheck? */
1187 if(qstate->qinfo.qtype == LDNS_RR_TYPE_NS &&
1188 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
1189 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
1190 /* spawn off A, AAAA queries for in-zone glue to check */
1191 generate_a_aaaa_check(qstate, iq, id);
1192 return;
1193 }
1194 /* no need to get the NS record for DS, it is above the zonecut */
1195 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DS)
1196 return;
1197
1198 log_nametypeclass(VERB_ALGO, "schedule ns fetch",
1199 iq->dp->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
1200 if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
1201 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
1202 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) {
1203 verbose(VERB_ALGO, "could not generate ns check");
1204 return;
1205 }
1206 if(subq) {
1207 struct iter_qstate* subiq =
1208 (struct iter_qstate*)subq->minfo[id];
1209
1210 /* make copy to avoid use of stub dp by different qs/threads */
1211 /* refetch glue to start higher up the tree */
1212 subiq->refetch_glue = 1;
1213 subiq->dp = delegpt_copy(iq->dp, subq->region);
1214 if(!subiq->dp) {
1215 log_err("out of memory generating ns check, copydp");
1216 fptr_ok(fptr_whitelist_modenv_kill_sub(
1217 qstate->env->kill_sub));
1218 (*qstate->env->kill_sub)(subq);
1219 return;
1220 }
1221 }
1222 }
1223
1224 /**
1225 * Generate a DNSKEY prefetch query to get the DNSKEY for the DS record we
1226 * just got in a referral (where we have dnssec_expected, thus have trust
1227 * anchors above it). Note that right after calling this routine the
1228 * iterator detached subqueries (because of following the referral), and thus
1229 * the DNSKEY query becomes detached, its return stored in the cache for
1230 * later lookup by the validator. This cache lookup by the validator avoids
1231 * the roundtrip incurred by the DNSKEY query. The DNSKEY query is now
1232 * performed at about the same time the original query is sent to the domain,
1233 * thus the two answers are likely to be returned at about the same time,
1234 * saving a roundtrip from the validated lookup.
1235 *
1236 * @param qstate: the qtstate that triggered the need to prime.
1237 * @param iq: iterator query state.
1238 * @param id: module id.
1239 */
1240 static void
generate_dnskey_prefetch(struct module_qstate * qstate,struct iter_qstate * iq,int id)1241 generate_dnskey_prefetch(struct module_qstate* qstate,
1242 struct iter_qstate* iq, int id)
1243 {
1244 struct module_qstate* subq;
1245 log_assert(iq->dp);
1246
1247 /* is this query the same as the prefetch? */
1248 if(qstate->qinfo.qtype == LDNS_RR_TYPE_DNSKEY &&
1249 query_dname_compare(iq->dp->name, qstate->qinfo.qname)==0 &&
1250 (qstate->query_flags&BIT_RD) && !(qstate->query_flags&BIT_CD)){
1251 return;
1252 }
1253 /* we do not generate this prefetch when the query list is full,
1254 * the query is fetched, if needed, when the validator wants it.
1255 * At that time the validator waits for it, after spawning it.
1256 * This means there is one state that uses cpu and a socket, the
1257 * spawned while this one waits, and not several at the same time,
1258 * if we had created the lookup here. And this helps to keep
1259 * the total load down, but the query still succeeds to resolve. */
1260 if(mesh_jostle_exceeded(qstate->env->mesh))
1261 return;
1262
1263 /* if the DNSKEY is in the cache this lookup will stop quickly */
1264 log_nametypeclass(VERB_ALGO, "schedule dnskey prefetch",
1265 iq->dp->name, LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass);
1266 if(!generate_sub_request(iq->dp->name, iq->dp->namelen,
1267 LDNS_RR_TYPE_DNSKEY, iq->qchase.qclass, qstate, id, iq,
1268 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0)) {
1269 /* we'll be slower, but it'll work */
1270 verbose(VERB_ALGO, "could not generate dnskey prefetch");
1271 return;
1272 }
1273 if(subq) {
1274 struct iter_qstate* subiq =
1275 (struct iter_qstate*)subq->minfo[id];
1276 /* this qstate has the right delegation for the dnskey lookup*/
1277 /* make copy to avoid use of stub dp by different qs/threads */
1278 subiq->dp = delegpt_copy(iq->dp, subq->region);
1279 /* if !subiq->dp, it'll start from the cache, no problem */
1280 }
1281 }
1282
1283 /**
1284 * See if the query needs forwarding.
1285 *
1286 * @param qstate: query state.
1287 * @param iq: iterator query state.
1288 * @return true if the request is forwarded, false if not.
1289 * If returns true but, iq->dp is NULL then a malloc failure occurred.
1290 */
1291 static int
forward_request(struct module_qstate * qstate,struct iter_qstate * iq)1292 forward_request(struct module_qstate* qstate, struct iter_qstate* iq)
1293 {
1294 struct delegpt* dp;
1295 uint8_t* delname = iq->qchase.qname;
1296 size_t delnamelen = iq->qchase.qname_len;
1297 if(iq->refetch_glue && iq->dp) {
1298 delname = iq->dp->name;
1299 delnamelen = iq->dp->namelen;
1300 }
1301 /* strip one label off of DS query to lookup higher for it */
1302 if( (iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue)
1303 && !dname_is_root(iq->qchase.qname))
1304 dname_remove_label(&delname, &delnamelen);
1305 dp = forwards_lookup(qstate->env->fwds, delname, iq->qchase.qclass);
1306 if(!dp)
1307 return 0;
1308 /* send recursion desired to forward addr */
1309 iq->chase_flags |= BIT_RD;
1310 iq->dp = delegpt_copy(dp, qstate->region);
1311 /* iq->dp checked by caller */
1312 verbose(VERB_ALGO, "forwarding request");
1313 return 1;
1314 }
1315
1316 /**
1317 * Process the initial part of the request handling. This state roughly
1318 * corresponds to resolver algorithms steps 1 (find answer in cache) and 2
1319 * (find the best servers to ask).
1320 *
1321 * Note that all requests start here, and query restarts revisit this state.
1322 *
1323 * This state either generates: 1) a response, from cache or error, 2) a
1324 * priming event, or 3) forwards the request to the next state (init2,
1325 * generally).
1326 *
1327 * @param qstate: query state.
1328 * @param iq: iterator query state.
1329 * @param ie: iterator shared global environment.
1330 * @param id: module id.
1331 * @return true if the event needs more request processing immediately,
1332 * false if not.
1333 */
1334 static int
processInitRequest(struct module_qstate * qstate,struct iter_qstate * iq,struct iter_env * ie,int id)1335 processInitRequest(struct module_qstate* qstate, struct iter_qstate* iq,
1336 struct iter_env* ie, int id)
1337 {
1338 uint8_t* delname, *dpname=NULL;
1339 size_t delnamelen, dpnamelen=0;
1340 struct dns_msg* msg = NULL;
1341
1342 log_query_info(VERB_DETAIL, "resolving", &qstate->qinfo);
1343 /* check effort */
1344
1345 /* We enforce a maximum number of query restarts. This is primarily a
1346 * cheap way to prevent CNAME loops. */
1347 if(iq->query_restart_count > ie->max_query_restarts) {
1348 verbose(VERB_QUERY, "request has exceeded the maximum number"
1349 " of query restarts with %d", iq->query_restart_count);
1350 errinf(qstate, "request has exceeded the maximum number "
1351 "restarts (eg. indirections)");
1352 if(iq->qchase.qname)
1353 errinf_dname(qstate, "stop at", iq->qchase.qname);
1354 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1355 }
1356
1357 /* We enforce a maximum recursion/dependency depth -- in general,
1358 * this is unnecessary for dependency loops (although it will
1359 * catch those), but it provides a sensible limit to the amount
1360 * of work required to answer a given query. */
1361 verbose(VERB_ALGO, "request has dependency depth of %d", iq->depth);
1362 if(iq->depth > ie->max_dependency_depth) {
1363 verbose(VERB_QUERY, "request has exceeded the maximum "
1364 "dependency depth with depth of %d", iq->depth);
1365 errinf(qstate, "request has exceeded the maximum dependency "
1366 "depth (eg. nameserver lookup recursion)");
1367 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1368 }
1369
1370 /* If the request is qclass=ANY, setup to generate each class */
1371 if(qstate->qinfo.qclass == LDNS_RR_CLASS_ANY) {
1372 iq->qchase.qclass = 0;
1373 return next_state(iq, COLLECT_CLASS_STATE);
1374 }
1375
1376 /*
1377 * If we are restricted by a forward-zone or a stub-zone, we
1378 * can't re-fetch glue for this delegation point.
1379 * we won’t try to re-fetch glue if the iq->dp is null.
1380 */
1381 if (iq->refetch_glue &&
1382 iq->dp &&
1383 !can_have_last_resort(qstate->env, iq->dp->name,
1384 iq->dp->namelen, iq->qchase.qclass, NULL)) {
1385 iq->refetch_glue = 0;
1386 }
1387
1388 /* Resolver Algorithm Step 1 -- Look for the answer in local data. */
1389
1390 /* This either results in a query restart (CNAME cache response), a
1391 * terminating response (ANSWER), or a cache miss (null). */
1392
1393 if (iter_stub_fwd_no_cache(qstate, &iq->qchase, &dpname, &dpnamelen)) {
1394 /* Asked to not query cache. */
1395 verbose(VERB_ALGO, "no-cache set, going to the network");
1396 qstate->no_cache_lookup = 1;
1397 qstate->no_cache_store = 1;
1398 msg = NULL;
1399 } else if(qstate->blacklist) {
1400 /* if cache, or anything else, was blacklisted then
1401 * getting older results from cache is a bad idea, no cache */
1402 verbose(VERB_ALGO, "cache blacklisted, going to the network");
1403 msg = NULL;
1404 } else if(!qstate->no_cache_lookup) {
1405 msg = dns_cache_lookup(qstate->env, iq->qchase.qname,
1406 iq->qchase.qname_len, iq->qchase.qtype,
1407 iq->qchase.qclass, qstate->query_flags,
1408 qstate->region, qstate->env->scratch, 0, dpname,
1409 dpnamelen);
1410 if(!msg && qstate->env->neg_cache &&
1411 iter_qname_indicates_dnssec(qstate->env, &iq->qchase)) {
1412 /* lookup in negative cache; may result in
1413 * NOERROR/NODATA or NXDOMAIN answers that need validation */
1414 msg = val_neg_getmsg(qstate->env->neg_cache, &iq->qchase,
1415 qstate->region, qstate->env->rrset_cache,
1416 qstate->env->scratch_buffer,
1417 *qstate->env->now, 1/*add SOA*/, NULL,
1418 qstate->env->cfg);
1419 }
1420 /* item taken from cache does not match our query name, thus
1421 * security needs to be re-examined later */
1422 if(msg && query_dname_compare(qstate->qinfo.qname,
1423 iq->qchase.qname) != 0)
1424 msg->rep->security = sec_status_unchecked;
1425 }
1426 if(msg) {
1427 /* handle positive cache response */
1428 enum response_type type = response_type_from_cache(msg,
1429 &iq->qchase);
1430 if(verbosity >= VERB_ALGO) {
1431 log_dns_msg("msg from cache lookup", &msg->qinfo,
1432 msg->rep);
1433 verbose(VERB_ALGO, "msg ttl is %d, prefetch ttl %d",
1434 (int)msg->rep->ttl,
1435 (int)msg->rep->prefetch_ttl);
1436 }
1437
1438 if(type == RESPONSE_TYPE_CNAME) {
1439 uint8_t* sname = 0;
1440 size_t slen = 0;
1441 verbose(VERB_ALGO, "returning CNAME response from "
1442 "cache");
1443 if(!handle_cname_response(qstate, iq, msg,
1444 &sname, &slen)) {
1445 errinf(qstate, "failed to prepend CNAME "
1446 "components, malloc failure");
1447 return error_response(qstate, id,
1448 LDNS_RCODE_SERVFAIL);
1449 }
1450 iq->qchase.qname = sname;
1451 iq->qchase.qname_len = slen;
1452 if(qstate->env->auth_zones) {
1453 /* apply rpz qname triggers after cname */
1454 struct dns_msg* forged_response =
1455 rpz_callback_from_iterator_cname(qstate, iq);
1456 while(forged_response && reply_find_rrset_section_an(
1457 forged_response->rep, iq->qchase.qname,
1458 iq->qchase.qname_len, LDNS_RR_TYPE_CNAME,
1459 iq->qchase.qclass)) {
1460 /* another cname to follow */
1461 if(!handle_cname_response(qstate, iq, forged_response,
1462 &sname, &slen)) {
1463 errinf(qstate, "malloc failure, CNAME info");
1464 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1465 }
1466 iq->qchase.qname = sname;
1467 iq->qchase.qname_len = slen;
1468 forged_response =
1469 rpz_callback_from_iterator_cname(qstate, iq);
1470 }
1471 if(forged_response != NULL) {
1472 qstate->ext_state[id] = module_finished;
1473 qstate->return_rcode = LDNS_RCODE_NOERROR;
1474 qstate->return_msg = forged_response;
1475 iq->response = forged_response;
1476 next_state(iq, FINISHED_STATE);
1477 if(!iter_prepend(iq, qstate->return_msg, qstate->region)) {
1478 log_err("rpz: after cached cname, prepend rrsets: out of memory");
1479 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1480 }
1481 qstate->return_msg->qinfo = qstate->qinfo;
1482 return 0;
1483 }
1484 }
1485 /* This *is* a query restart, even if it is a cheap
1486 * one. */
1487 iq->dp = NULL;
1488 iq->refetch_glue = 0;
1489 iq->query_restart_count++;
1490 iq->sent_count = 0;
1491 iq->dp_target_count = 0;
1492 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1493 if(qstate->env->cfg->qname_minimisation)
1494 iq->minimisation_state = INIT_MINIMISE_STATE;
1495 return next_state(iq, INIT_REQUEST_STATE);
1496 }
1497
1498 /* if from cache, NULL, else insert 'cache IP' len=0 */
1499 if(qstate->reply_origin)
1500 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1501 if(FLAGS_GET_RCODE(msg->rep->flags) == LDNS_RCODE_SERVFAIL)
1502 errinf(qstate, "SERVFAIL in cache");
1503 /* it is an answer, response, to final state */
1504 verbose(VERB_ALGO, "returning answer from cache.");
1505 iq->response = msg;
1506 return final_state(iq);
1507 }
1508
1509 /* attempt to forward the request */
1510 if(forward_request(qstate, iq))
1511 {
1512 if(!iq->dp) {
1513 log_err("alloc failure for forward dp");
1514 errinf(qstate, "malloc failure for forward zone");
1515 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1516 }
1517 if((qstate->query_flags&BIT_RD)==0) {
1518 /* If the server accepts RD=0 queries and forwards
1519 * with RD=1, then if the server is listed as an NS
1520 * entry, it starts query loops. Stop that loop by
1521 * disallowing the query. The RD=0 was previously used
1522 * to check the cache with allow_snoop. For stubs,
1523 * the iterator pass would have primed the stub and
1524 * then cached information can be used for further
1525 * queries. */
1526 verbose(VERB_ALGO, "cannot forward RD=0 query, to stop query loops");
1527 errinf(qstate, "cannot forward RD=0 query");
1528 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1529 }
1530 iq->refetch_glue = 0;
1531 iq->minimisation_state = DONOT_MINIMISE_STATE;
1532 /* the request has been forwarded.
1533 * forwarded requests need to be immediately sent to the
1534 * next state, QUERYTARGETS. */
1535 return next_state(iq, QUERYTARGETS_STATE);
1536 }
1537
1538 /* Resolver Algorithm Step 2 -- find the "best" servers. */
1539
1540 /* first, adjust for DS queries. To avoid the grandparent problem,
1541 * we just look for the closest set of server to the parent of qname.
1542 * When re-fetching glue we also need to ask the parent.
1543 */
1544 if(iq->refetch_glue) {
1545 if(!iq->dp) {
1546 log_err("internal or malloc fail: no dp for refetch");
1547 errinf(qstate, "malloc failure, for delegation info");
1548 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1549 }
1550 delname = iq->dp->name;
1551 delnamelen = iq->dp->namelen;
1552 } else {
1553 delname = iq->qchase.qname;
1554 delnamelen = iq->qchase.qname_len;
1555 }
1556 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue ||
1557 (iq->qchase.qtype == LDNS_RR_TYPE_NS && qstate->prefetch_leeway
1558 && can_have_last_resort(qstate->env, delname, delnamelen, iq->qchase.qclass, NULL))) {
1559 /* remove first label from delname, root goes to hints,
1560 * but only to fetch glue, not for qtype=DS. */
1561 /* also when prefetching an NS record, fetch it again from
1562 * its parent, just as if it expired, so that you do not
1563 * get stuck on an older nameserver that gives old NSrecords */
1564 if(dname_is_root(delname) && (iq->refetch_glue ||
1565 (iq->qchase.qtype == LDNS_RR_TYPE_NS &&
1566 qstate->prefetch_leeway)))
1567 delname = NULL; /* go to root priming */
1568 else dname_remove_label(&delname, &delnamelen);
1569 }
1570 /* delname is the name to lookup a delegation for. If NULL rootprime */
1571 while(1) {
1572
1573 /* Lookup the delegation in the cache. If null, then the
1574 * cache needs to be primed for the qclass. */
1575 if(delname)
1576 iq->dp = dns_cache_find_delegation(qstate->env, delname,
1577 delnamelen, iq->qchase.qtype, iq->qchase.qclass,
1578 qstate->region, &iq->deleg_msg,
1579 *qstate->env->now+qstate->prefetch_leeway, 1,
1580 dpname, dpnamelen);
1581 else iq->dp = NULL;
1582
1583 /* If the cache has returned nothing, then we have a
1584 * root priming situation. */
1585 if(iq->dp == NULL) {
1586 int r;
1587 /* if under auth zone, no prime needed */
1588 if(!auth_zone_delegpt(qstate, iq, delname, delnamelen))
1589 return error_response(qstate, id,
1590 LDNS_RCODE_SERVFAIL);
1591 if(iq->dp) /* use auth zone dp */
1592 return next_state(iq, INIT_REQUEST_2_STATE);
1593 /* if there is a stub, then no root prime needed */
1594 r = prime_stub(qstate, iq, id, delname,
1595 iq->qchase.qclass);
1596 if(r == 2)
1597 break; /* got noprime-stub-zone, continue */
1598 else if(r)
1599 return 0; /* stub prime request made */
1600 if(forwards_lookup_root(qstate->env->fwds,
1601 iq->qchase.qclass)) {
1602 /* forward zone root, no root prime needed */
1603 /* fill in some dp - safety belt */
1604 iq->dp = hints_lookup_root(qstate->env->hints,
1605 iq->qchase.qclass);
1606 if(!iq->dp) {
1607 log_err("internal error: no hints dp");
1608 errinf(qstate, "no hints for this class");
1609 return error_response(qstate, id,
1610 LDNS_RCODE_SERVFAIL);
1611 }
1612 iq->dp = delegpt_copy(iq->dp, qstate->region);
1613 if(!iq->dp) {
1614 log_err("out of memory in safety belt");
1615 errinf(qstate, "malloc failure, in safety belt");
1616 return error_response(qstate, id,
1617 LDNS_RCODE_SERVFAIL);
1618 }
1619 return next_state(iq, INIT_REQUEST_2_STATE);
1620 }
1621 /* Note that the result of this will set a new
1622 * DelegationPoint based on the result of priming. */
1623 if(!prime_root(qstate, iq, id, iq->qchase.qclass))
1624 return error_response(qstate, id,
1625 LDNS_RCODE_REFUSED);
1626
1627 /* priming creates and sends a subordinate query, with
1628 * this query as the parent. So further processing for
1629 * this event will stop until reactivated by the
1630 * results of priming. */
1631 return 0;
1632 }
1633 if(!iq->ratelimit_ok && qstate->prefetch_leeway)
1634 iq->ratelimit_ok = 1; /* allow prefetches, this keeps
1635 otherwise valid data in the cache */
1636
1637 /* see if this dp not useless.
1638 * It is useless if:
1639 * o all NS items are required glue.
1640 * or the query is for NS item that is required glue.
1641 * o no addresses are provided.
1642 * o RD qflag is on.
1643 * Instead, go up one level, and try to get even further
1644 * If the root was useless, use safety belt information.
1645 * Only check cache returns, because replies for servers
1646 * could be useless but lead to loops (bumping into the
1647 * same server reply) if useless-checked.
1648 */
1649 if(iter_dp_is_useless(&qstate->qinfo, qstate->query_flags,
1650 iq->dp, ie->supports_ipv4, ie->supports_ipv6,
1651 ie->use_nat64)) {
1652 struct delegpt* retdp = NULL;
1653 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen, iq->qchase.qclass, &retdp)) {
1654 if(retdp) {
1655 verbose(VERB_QUERY, "cache has stub "
1656 "or fwd but no addresses, "
1657 "fallback to config");
1658 iq->dp = delegpt_copy(retdp,
1659 qstate->region);
1660 if(!iq->dp) {
1661 log_err("out of memory in "
1662 "stub/fwd fallback");
1663 errinf(qstate, "malloc failure, for fallback to config");
1664 return error_response(qstate,
1665 id, LDNS_RCODE_SERVFAIL);
1666 }
1667 break;
1668 }
1669 verbose(VERB_ALGO, "useless dp "
1670 "but cannot go up, servfail");
1671 delegpt_log(VERB_ALGO, iq->dp);
1672 errinf(qstate, "no useful nameservers, "
1673 "and cannot go up");
1674 errinf_dname(qstate, "for zone", iq->dp->name);
1675 return error_response(qstate, id,
1676 LDNS_RCODE_SERVFAIL);
1677 }
1678 if(dname_is_root(iq->dp->name)) {
1679 /* use safety belt */
1680 verbose(VERB_QUERY, "Cache has root NS but "
1681 "no addresses. Fallback to the safety belt.");
1682 iq->dp = hints_lookup_root(qstate->env->hints,
1683 iq->qchase.qclass);
1684 /* note deleg_msg is from previous lookup,
1685 * but RD is on, so it is not used */
1686 if(!iq->dp) {
1687 log_err("internal error: no hints dp");
1688 return error_response(qstate, id,
1689 LDNS_RCODE_REFUSED);
1690 }
1691 iq->dp = delegpt_copy(iq->dp, qstate->region);
1692 if(!iq->dp) {
1693 log_err("out of memory in safety belt");
1694 errinf(qstate, "malloc failure, in safety belt, for root");
1695 return error_response(qstate, id,
1696 LDNS_RCODE_SERVFAIL);
1697 }
1698 break;
1699 } else {
1700 verbose(VERB_ALGO,
1701 "cache delegation was useless:");
1702 delegpt_log(VERB_ALGO, iq->dp);
1703 /* go up */
1704 delname = iq->dp->name;
1705 delnamelen = iq->dp->namelen;
1706 dname_remove_label(&delname, &delnamelen);
1707 }
1708 } else break;
1709 }
1710
1711 verbose(VERB_ALGO, "cache delegation returns delegpt");
1712 delegpt_log(VERB_ALGO, iq->dp);
1713
1714 /* Otherwise, set the current delegation point and move on to the
1715 * next state. */
1716 return next_state(iq, INIT_REQUEST_2_STATE);
1717 }
1718
1719 /**
1720 * Process the second part of the initial request handling. This state
1721 * basically exists so that queries that generate root priming events have
1722 * the same init processing as ones that do not. Request events that reach
1723 * this state must have a valid currentDelegationPoint set.
1724 *
1725 * This part is primarily handling stub zone priming. Events that reach this
1726 * state must have a current delegation point.
1727 *
1728 * @param qstate: query state.
1729 * @param iq: iterator query state.
1730 * @param id: module id.
1731 * @return true if the event needs more request processing immediately,
1732 * false if not.
1733 */
1734 static int
processInitRequest2(struct module_qstate * qstate,struct iter_qstate * iq,int id)1735 processInitRequest2(struct module_qstate* qstate, struct iter_qstate* iq,
1736 int id)
1737 {
1738 uint8_t* delname;
1739 size_t delnamelen;
1740 log_query_info(VERB_QUERY, "resolving (init part 2): ",
1741 &qstate->qinfo);
1742
1743 delname = iq->qchase.qname;
1744 delnamelen = iq->qchase.qname_len;
1745 if(iq->refetch_glue) {
1746 struct iter_hints_stub* stub;
1747 if(!iq->dp) {
1748 log_err("internal or malloc fail: no dp for refetch");
1749 errinf(qstate, "malloc failure, no delegation info");
1750 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1751 }
1752 /* Do not send queries above stub, do not set delname to dp if
1753 * this is above stub without stub-first. */
1754 stub = hints_lookup_stub(
1755 qstate->env->hints, iq->qchase.qname, iq->qchase.qclass,
1756 iq->dp);
1757 if(!stub || !stub->dp->has_parent_side_NS ||
1758 dname_subdomain_c(iq->dp->name, stub->dp->name)) {
1759 delname = iq->dp->name;
1760 delnamelen = iq->dp->namelen;
1761 }
1762 }
1763 if(iq->qchase.qtype == LDNS_RR_TYPE_DS || iq->refetch_glue) {
1764 if(!dname_is_root(delname))
1765 dname_remove_label(&delname, &delnamelen);
1766 iq->refetch_glue = 0; /* if CNAME causes restart, no refetch */
1767 }
1768
1769 /* see if we have an auth zone to answer from, improves dp from cache
1770 * (if any dp from cache) with auth zone dp, if that is lower */
1771 if(!auth_zone_delegpt(qstate, iq, delname, delnamelen))
1772 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
1773
1774 /* Check to see if we need to prime a stub zone. */
1775 if(prime_stub(qstate, iq, id, delname, iq->qchase.qclass)) {
1776 /* A priming sub request was made */
1777 return 0;
1778 }
1779
1780 /* most events just get forwarded to the next state. */
1781 return next_state(iq, INIT_REQUEST_3_STATE);
1782 }
1783
1784 /**
1785 * Process the third part of the initial request handling. This state exists
1786 * as a separate state so that queries that generate stub priming events
1787 * will get the tail end of the init process but not repeat the stub priming
1788 * check.
1789 *
1790 * @param qstate: query state.
1791 * @param iq: iterator query state.
1792 * @param id: module id.
1793 * @return true, advancing the event to the QUERYTARGETS_STATE.
1794 */
1795 static int
processInitRequest3(struct module_qstate * qstate,struct iter_qstate * iq,int id)1796 processInitRequest3(struct module_qstate* qstate, struct iter_qstate* iq,
1797 int id)
1798 {
1799 log_query_info(VERB_QUERY, "resolving (init part 3): ",
1800 &qstate->qinfo);
1801 /* if the cache reply dp equals a validation anchor or msg has DS,
1802 * then DNSSEC RRSIGs are expected in the reply */
1803 iq->dnssec_expected = iter_indicates_dnssec(qstate->env, iq->dp,
1804 iq->deleg_msg, iq->qchase.qclass);
1805
1806 /* If the RD flag wasn't set, then we just finish with the
1807 * cached referral as the response. */
1808 if(!(qstate->query_flags & BIT_RD) && iq->deleg_msg) {
1809 iq->response = iq->deleg_msg;
1810 if(verbosity >= VERB_ALGO && iq->response)
1811 log_dns_msg("no RD requested, using delegation msg",
1812 &iq->response->qinfo, iq->response->rep);
1813 if(qstate->reply_origin)
1814 sock_list_insert(&qstate->reply_origin, NULL, 0, qstate->region);
1815 return final_state(iq);
1816 }
1817 /* After this point, unset the RD flag -- this query is going to
1818 * be sent to an auth. server. */
1819 iq->chase_flags &= ~BIT_RD;
1820
1821 /* if dnssec expected, fetch key for the trust-anchor or cached-DS */
1822 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
1823 !(qstate->query_flags&BIT_CD)) {
1824 generate_dnskey_prefetch(qstate, iq, id);
1825 fptr_ok(fptr_whitelist_modenv_detach_subs(
1826 qstate->env->detach_subs));
1827 (*qstate->env->detach_subs)(qstate);
1828 }
1829
1830 /* Jump to the next state. */
1831 return next_state(iq, QUERYTARGETS_STATE);
1832 }
1833
1834 /**
1835 * Given a basic query, generate a parent-side "target" query.
1836 * These are subordinate queries for missing delegation point target addresses,
1837 * for which only the parent of the delegation provides correct IP addresses.
1838 *
1839 * @param qstate: query state.
1840 * @param iq: iterator query state.
1841 * @param id: module id.
1842 * @param name: target qname.
1843 * @param namelen: target qname length.
1844 * @param qtype: target qtype (either A or AAAA).
1845 * @param qclass: target qclass.
1846 * @return true on success, false on failure.
1847 */
1848 static int
generate_parentside_target_query(struct module_qstate * qstate,struct iter_qstate * iq,int id,uint8_t * name,size_t namelen,uint16_t qtype,uint16_t qclass)1849 generate_parentside_target_query(struct module_qstate* qstate,
1850 struct iter_qstate* iq, int id, uint8_t* name, size_t namelen,
1851 uint16_t qtype, uint16_t qclass)
1852 {
1853 struct module_qstate* subq;
1854 if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
1855 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0))
1856 return 0;
1857 if(subq) {
1858 struct iter_qstate* subiq =
1859 (struct iter_qstate*)subq->minfo[id];
1860 /* blacklist the cache - we want to fetch parent stuff */
1861 sock_list_insert(&subq->blacklist, NULL, 0, subq->region);
1862 subiq->query_for_pside_glue = 1;
1863 if(dname_subdomain_c(name, iq->dp->name)) {
1864 subiq->dp = delegpt_copy(iq->dp, subq->region);
1865 subiq->dnssec_expected = iter_indicates_dnssec(
1866 qstate->env, subiq->dp, NULL,
1867 subq->qinfo.qclass);
1868 subiq->refetch_glue = 1;
1869 } else {
1870 subiq->dp = dns_cache_find_delegation(qstate->env,
1871 name, namelen, qtype, qclass, subq->region,
1872 &subiq->deleg_msg,
1873 *qstate->env->now+subq->prefetch_leeway,
1874 1, NULL, 0);
1875 /* if no dp, then it's from root, refetch unneeded */
1876 if(subiq->dp) {
1877 subiq->dnssec_expected = iter_indicates_dnssec(
1878 qstate->env, subiq->dp, NULL,
1879 subq->qinfo.qclass);
1880 subiq->refetch_glue = 1;
1881 }
1882 }
1883 }
1884 log_nametypeclass(VERB_QUERY, "new pside target", name, qtype, qclass);
1885 return 1;
1886 }
1887
1888 /**
1889 * Given a basic query, generate a "target" query. These are subordinate
1890 * queries for missing delegation point target addresses.
1891 *
1892 * @param qstate: query state.
1893 * @param iq: iterator query state.
1894 * @param id: module id.
1895 * @param name: target qname.
1896 * @param namelen: target qname length.
1897 * @param qtype: target qtype (either A or AAAA).
1898 * @param qclass: target qclass.
1899 * @return true on success, false on failure.
1900 */
1901 static int
generate_target_query(struct module_qstate * qstate,struct iter_qstate * iq,int id,uint8_t * name,size_t namelen,uint16_t qtype,uint16_t qclass)1902 generate_target_query(struct module_qstate* qstate, struct iter_qstate* iq,
1903 int id, uint8_t* name, size_t namelen, uint16_t qtype, uint16_t qclass)
1904 {
1905 struct module_qstate* subq;
1906 if(!generate_sub_request(name, namelen, qtype, qclass, qstate,
1907 id, iq, INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0))
1908 return 0;
1909 log_nametypeclass(VERB_QUERY, "new target", name, qtype, qclass);
1910 return 1;
1911 }
1912
1913 /**
1914 * Given an event at a certain state, generate zero or more target queries
1915 * for it's current delegation point.
1916 *
1917 * @param qstate: query state.
1918 * @param iq: iterator query state.
1919 * @param ie: iterator shared global environment.
1920 * @param id: module id.
1921 * @param maxtargets: The maximum number of targets to query for.
1922 * if it is negative, there is no maximum number of targets.
1923 * @param num: returns the number of queries generated and processed,
1924 * which may be zero if there were no missing targets.
1925 * @return false on error.
1926 */
1927 static int
query_for_targets(struct module_qstate * qstate,struct iter_qstate * iq,struct iter_env * ie,int id,int maxtargets,int * num)1928 query_for_targets(struct module_qstate* qstate, struct iter_qstate* iq,
1929 struct iter_env* ie, int id, int maxtargets, int* num)
1930 {
1931 int query_count = 0;
1932 struct delegpt_ns* ns;
1933 int missing;
1934 int toget = 0;
1935
1936 iter_mark_cycle_targets(qstate, iq->dp);
1937 missing = (int)delegpt_count_missing_targets(iq->dp, NULL);
1938 log_assert(maxtargets != 0); /* that would not be useful */
1939
1940 /* Generate target requests. Basically, any missing targets
1941 * are queried for here, regardless if it is necessary to do
1942 * so to continue processing. */
1943 if(maxtargets < 0 || maxtargets > missing)
1944 toget = missing;
1945 else toget = maxtargets;
1946 if(toget == 0) {
1947 *num = 0;
1948 return 1;
1949 }
1950
1951 /* now that we are sure that a target query is going to be made,
1952 * check the limits. */
1953 if(iq->depth == ie->max_dependency_depth)
1954 return 0;
1955 if(iq->depth > 0 && iq->target_count &&
1956 iq->target_count[TARGET_COUNT_QUERIES] > MAX_TARGET_COUNT) {
1957 char s[LDNS_MAX_DOMAINLEN+1];
1958 dname_str(qstate->qinfo.qname, s);
1959 verbose(VERB_QUERY, "request %s has exceeded the maximum "
1960 "number of glue fetches %d", s,
1961 iq->target_count[TARGET_COUNT_QUERIES]);
1962 return 0;
1963 }
1964 if(iq->dp_target_count > MAX_DP_TARGET_COUNT) {
1965 char s[LDNS_MAX_DOMAINLEN+1];
1966 dname_str(qstate->qinfo.qname, s);
1967 verbose(VERB_QUERY, "request %s has exceeded the maximum "
1968 "number of glue fetches %d to a single delegation point",
1969 s, iq->dp_target_count);
1970 return 0;
1971 }
1972
1973 /* select 'toget' items from the total of 'missing' items */
1974 log_assert(toget <= missing);
1975
1976 /* loop over missing targets */
1977 for(ns = iq->dp->nslist; ns; ns = ns->next) {
1978 if(ns->resolved)
1979 continue;
1980
1981 /* randomly select this item with probability toget/missing */
1982 if(!iter_ns_probability(qstate->env->rnd, toget, missing)) {
1983 /* do not select this one, next; select toget number
1984 * of items from a list one less in size */
1985 missing --;
1986 continue;
1987 }
1988
1989 if(ie->supports_ipv6 &&
1990 ((ns->lame && !ns->done_pside6) ||
1991 (!ns->lame && !ns->got6))) {
1992 /* Send the AAAA request. */
1993 if(!generate_target_query(qstate, iq, id,
1994 ns->name, ns->namelen,
1995 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) {
1996 *num = query_count;
1997 if(query_count > 0)
1998 qstate->ext_state[id] = module_wait_subquery;
1999 return 0;
2000 }
2001 query_count++;
2002 /* If the mesh query list is full, exit the loop here.
2003 * This makes the routine spawn one query at a time,
2004 * and this means there is no query state load
2005 * increase, because the spawned state uses cpu and a
2006 * socket while this state waits for that spawned
2007 * state. Next time we can look up further targets */
2008 if(mesh_jostle_exceeded(qstate->env->mesh))
2009 break;
2010 }
2011 /* Send the A request. */
2012 if((ie->supports_ipv4 || ie->use_nat64) &&
2013 ((ns->lame && !ns->done_pside4) ||
2014 (!ns->lame && !ns->got4))) {
2015 if(!generate_target_query(qstate, iq, id,
2016 ns->name, ns->namelen,
2017 LDNS_RR_TYPE_A, iq->qchase.qclass)) {
2018 *num = query_count;
2019 if(query_count > 0)
2020 qstate->ext_state[id] = module_wait_subquery;
2021 return 0;
2022 }
2023 query_count++;
2024 /* If the mesh query list is full, exit the loop. */
2025 if(mesh_jostle_exceeded(qstate->env->mesh))
2026 break;
2027 }
2028
2029 /* mark this target as in progress. */
2030 ns->resolved = 1;
2031 missing--;
2032 toget--;
2033 if(toget == 0)
2034 break;
2035 }
2036 *num = query_count;
2037 if(query_count > 0)
2038 qstate->ext_state[id] = module_wait_subquery;
2039
2040 return 1;
2041 }
2042
2043 /**
2044 * Called by processQueryTargets when it would like extra targets to query
2045 * but it seems to be out of options. At last resort some less appealing
2046 * options are explored. If there are no more options, the result is SERVFAIL
2047 *
2048 * @param qstate: query state.
2049 * @param iq: iterator query state.
2050 * @param ie: iterator shared global environment.
2051 * @param id: module id.
2052 * @return true if the event requires more request processing immediately,
2053 * false if not.
2054 */
2055 static int
processLastResort(struct module_qstate * qstate,struct iter_qstate * iq,struct iter_env * ie,int id)2056 processLastResort(struct module_qstate* qstate, struct iter_qstate* iq,
2057 struct iter_env* ie, int id)
2058 {
2059 struct delegpt_ns* ns;
2060 int query_count = 0;
2061 verbose(VERB_ALGO, "No more query targets, attempting last resort");
2062 log_assert(iq->dp);
2063
2064 if(!can_have_last_resort(qstate->env, iq->dp->name, iq->dp->namelen,
2065 iq->qchase.qclass, NULL)) {
2066 /* fail -- no more targets, no more hope of targets, no hope
2067 * of a response. */
2068 errinf(qstate, "all the configured stub or forward servers failed,");
2069 errinf_dname(qstate, "at zone", iq->dp->name);
2070 errinf_reply(qstate, iq);
2071 verbose(VERB_QUERY, "configured stub or forward servers failed -- returning SERVFAIL");
2072 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2073 }
2074 if(!iq->dp->has_parent_side_NS && dname_is_root(iq->dp->name)) {
2075 struct delegpt* p = hints_lookup_root(qstate->env->hints,
2076 iq->qchase.qclass);
2077 if(p) {
2078 struct delegpt_addr* a;
2079 iq->chase_flags &= ~BIT_RD; /* go to authorities */
2080 for(ns = p->nslist; ns; ns=ns->next) {
2081 (void)delegpt_add_ns(iq->dp, qstate->region,
2082 ns->name, ns->lame, ns->tls_auth_name,
2083 ns->port);
2084 }
2085 for(a = p->target_list; a; a=a->next_target) {
2086 (void)delegpt_add_addr(iq->dp, qstate->region,
2087 &a->addr, a->addrlen, a->bogus,
2088 a->lame, a->tls_auth_name, -1, NULL);
2089 }
2090 }
2091 iq->dp->has_parent_side_NS = 1;
2092 } else if(!iq->dp->has_parent_side_NS) {
2093 if(!iter_lookup_parent_NS_from_cache(qstate->env, iq->dp,
2094 qstate->region, &qstate->qinfo)
2095 || !iq->dp->has_parent_side_NS) {
2096 /* if: malloc failure in lookup go up to try */
2097 /* if: no parent NS in cache - go up one level */
2098 verbose(VERB_ALGO, "try to grab parent NS");
2099 iq->store_parent_NS = iq->dp;
2100 iq->chase_flags &= ~BIT_RD; /* go to authorities */
2101 iq->deleg_msg = NULL;
2102 iq->refetch_glue = 1;
2103 iq->query_restart_count++;
2104 iq->sent_count = 0;
2105 iq->dp_target_count = 0;
2106 if(qstate->env->cfg->qname_minimisation)
2107 iq->minimisation_state = INIT_MINIMISE_STATE;
2108 return next_state(iq, INIT_REQUEST_STATE);
2109 }
2110 }
2111 /* see if that makes new names available */
2112 if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
2113 qstate->region, iq->dp))
2114 log_err("out of memory in cache_fill_missing");
2115 if(iq->dp->usable_list) {
2116 verbose(VERB_ALGO, "try parent-side-name, w. glue from cache");
2117 return next_state(iq, QUERYTARGETS_STATE);
2118 }
2119 /* try to fill out parent glue from cache */
2120 if(iter_lookup_parent_glue_from_cache(qstate->env, iq->dp,
2121 qstate->region, &qstate->qinfo)) {
2122 /* got parent stuff from cache, see if we can continue */
2123 verbose(VERB_ALGO, "try parent-side glue from cache");
2124 return next_state(iq, QUERYTARGETS_STATE);
2125 }
2126 /* query for an extra name added by the parent-NS record */
2127 if(delegpt_count_missing_targets(iq->dp, NULL) > 0) {
2128 int qs = 0;
2129 verbose(VERB_ALGO, "try parent-side target name");
2130 if(!query_for_targets(qstate, iq, ie, id, 1, &qs)) {
2131 errinf(qstate, "could not fetch nameserver");
2132 errinf_dname(qstate, "at zone", iq->dp->name);
2133 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2134 }
2135 iq->num_target_queries += qs;
2136 target_count_increase(iq, qs);
2137 if(qs != 0) {
2138 qstate->ext_state[id] = module_wait_subquery;
2139 return 0; /* and wait for them */
2140 }
2141 }
2142 if(iq->depth == ie->max_dependency_depth) {
2143 verbose(VERB_QUERY, "maxdepth and need more nameservers, fail");
2144 errinf(qstate, "cannot fetch more nameservers because at max dependency depth");
2145 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2146 }
2147 if(iq->depth > 0 && iq->target_count &&
2148 iq->target_count[TARGET_COUNT_QUERIES] > MAX_TARGET_COUNT) {
2149 char s[LDNS_MAX_DOMAINLEN+1];
2150 dname_str(qstate->qinfo.qname, s);
2151 verbose(VERB_QUERY, "request %s has exceeded the maximum "
2152 "number of glue fetches %d", s,
2153 iq->target_count[TARGET_COUNT_QUERIES]);
2154 errinf(qstate, "exceeded the maximum number of glue fetches");
2155 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2156 }
2157 /* mark cycle targets for parent-side lookups */
2158 iter_mark_pside_cycle_targets(qstate, iq->dp);
2159 /* see if we can issue queries to get nameserver addresses */
2160 /* this lookup is not randomized, but sequential. */
2161 for(ns = iq->dp->nslist; ns; ns = ns->next) {
2162 /* if this nameserver is at a delegation point, but that
2163 * delegation point is a stub and we cannot go higher, skip*/
2164 if( ((ie->supports_ipv6 && !ns->done_pside6) ||
2165 ((ie->supports_ipv4 || ie->use_nat64) && !ns->done_pside4)) &&
2166 !can_have_last_resort(qstate->env, ns->name, ns->namelen,
2167 iq->qchase.qclass, NULL)) {
2168 log_nametypeclass(VERB_ALGO, "cannot pside lookup ns "
2169 "because it is also a stub/forward,",
2170 ns->name, LDNS_RR_TYPE_NS, iq->qchase.qclass);
2171 if(ie->supports_ipv6) ns->done_pside6 = 1;
2172 if(ie->supports_ipv4 || ie->use_nat64) ns->done_pside4 = 1;
2173 continue;
2174 }
2175 /* query for parent-side A and AAAA for nameservers */
2176 if(ie->supports_ipv6 && !ns->done_pside6) {
2177 /* Send the AAAA request. */
2178 if(!generate_parentside_target_query(qstate, iq, id,
2179 ns->name, ns->namelen,
2180 LDNS_RR_TYPE_AAAA, iq->qchase.qclass)) {
2181 errinf_dname(qstate, "could not generate nameserver AAAA lookup for", ns->name);
2182 return error_response(qstate, id,
2183 LDNS_RCODE_SERVFAIL);
2184 }
2185 ns->done_pside6 = 1;
2186 query_count++;
2187 if(mesh_jostle_exceeded(qstate->env->mesh)) {
2188 /* Wait for the lookup; do not spawn multiple
2189 * lookups at a time. */
2190 verbose(VERB_ALGO, "try parent-side glue lookup");
2191 iq->num_target_queries += query_count;
2192 target_count_increase(iq, query_count);
2193 qstate->ext_state[id] = module_wait_subquery;
2194 return 0;
2195 }
2196 }
2197 if((ie->supports_ipv4 || ie->use_nat64) && !ns->done_pside4) {
2198 /* Send the A request. */
2199 if(!generate_parentside_target_query(qstate, iq, id,
2200 ns->name, ns->namelen,
2201 LDNS_RR_TYPE_A, iq->qchase.qclass)) {
2202 errinf_dname(qstate, "could not generate nameserver A lookup for", ns->name);
2203 return error_response(qstate, id,
2204 LDNS_RCODE_SERVFAIL);
2205 }
2206 ns->done_pside4 = 1;
2207 query_count++;
2208 }
2209 if(query_count != 0) { /* suspend to await results */
2210 verbose(VERB_ALGO, "try parent-side glue lookup");
2211 iq->num_target_queries += query_count;
2212 target_count_increase(iq, query_count);
2213 qstate->ext_state[id] = module_wait_subquery;
2214 return 0;
2215 }
2216 }
2217
2218 /* if this was a parent-side glue query itself, then store that
2219 * failure in cache. */
2220 if(!qstate->no_cache_store && iq->query_for_pside_glue
2221 && !iq->pside_glue)
2222 iter_store_parentside_neg(qstate->env, &qstate->qinfo,
2223 iq->deleg_msg?iq->deleg_msg->rep:
2224 (iq->response?iq->response->rep:NULL));
2225
2226 errinf(qstate, "all servers for this domain failed,");
2227 errinf_dname(qstate, "at zone", iq->dp->name);
2228 errinf_reply(qstate, iq);
2229 verbose(VERB_QUERY, "out of query targets -- returning SERVFAIL");
2230 /* fail -- no more targets, no more hope of targets, no hope
2231 * of a response. */
2232 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2233 }
2234
2235 /**
2236 * Try to find the NS record set that will resolve a qtype DS query. Due
2237 * to grandparent/grandchild reasons we did not get a proper lookup right
2238 * away. We need to create type NS queries until we get the right parent
2239 * for this lookup. We remove labels from the query to find the right point.
2240 * If we end up at the old dp name, then there is no solution.
2241 *
2242 * @param qstate: query state.
2243 * @param iq: iterator query state.
2244 * @param id: module id.
2245 * @return true if the event requires more immediate processing, false if
2246 * not. This is generally only true when forwarding the request to
2247 * the final state (i.e., on answer).
2248 */
2249 static int
processDSNSFind(struct module_qstate * qstate,struct iter_qstate * iq,int id)2250 processDSNSFind(struct module_qstate* qstate, struct iter_qstate* iq, int id)
2251 {
2252 struct module_qstate* subq = NULL;
2253 verbose(VERB_ALGO, "processDSNSFind");
2254
2255 if(!iq->dsns_point) {
2256 /* initialize */
2257 iq->dsns_point = iq->qchase.qname;
2258 iq->dsns_point_len = iq->qchase.qname_len;
2259 }
2260 /* robustcheck for internal error: we are not underneath the dp */
2261 if(!dname_subdomain_c(iq->dsns_point, iq->dp->name)) {
2262 errinf_dname(qstate, "for DS query parent-child nameserver search the query is not under the zone", iq->dp->name);
2263 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2264 }
2265
2266 /* go up one (more) step, until we hit the dp, if so, end */
2267 dname_remove_label(&iq->dsns_point, &iq->dsns_point_len);
2268 if(query_dname_compare(iq->dsns_point, iq->dp->name) == 0) {
2269 /* there was no inbetween nameserver, use the old delegation
2270 * point again. And this time, because dsns_point is nonNULL
2271 * we are going to accept the (bad) result */
2272 iq->state = QUERYTARGETS_STATE;
2273 return 1;
2274 }
2275 iq->state = DSNS_FIND_STATE;
2276
2277 /* spawn NS lookup (validation not needed, this is for DS lookup) */
2278 log_nametypeclass(VERB_ALGO, "fetch nameservers",
2279 iq->dsns_point, LDNS_RR_TYPE_NS, iq->qchase.qclass);
2280 if(!generate_sub_request(iq->dsns_point, iq->dsns_point_len,
2281 LDNS_RR_TYPE_NS, iq->qchase.qclass, qstate, id, iq,
2282 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 0, 0)) {
2283 errinf_dname(qstate, "for DS query parent-child nameserver search, could not generate NS lookup for", iq->dsns_point);
2284 return error_response_cache(qstate, id, LDNS_RCODE_SERVFAIL);
2285 }
2286
2287 return 0;
2288 }
2289
2290 /**
2291 * Check if we wait responses for sent queries and update the iterator's
2292 * external state.
2293 */
2294 static void
check_waiting_queries(struct iter_qstate * iq,struct module_qstate * qstate,int id)2295 check_waiting_queries(struct iter_qstate* iq, struct module_qstate* qstate,
2296 int id)
2297 {
2298 if(iq->num_target_queries>0 && iq->num_current_queries>0) {
2299 verbose(VERB_ALGO, "waiting for %d targets to "
2300 "resolve or %d outstanding queries to "
2301 "respond", iq->num_target_queries,
2302 iq->num_current_queries);
2303 qstate->ext_state[id] = module_wait_reply;
2304 } else if(iq->num_target_queries>0) {
2305 verbose(VERB_ALGO, "waiting for %d targets to "
2306 "resolve", iq->num_target_queries);
2307 qstate->ext_state[id] = module_wait_subquery;
2308 } else {
2309 verbose(VERB_ALGO, "waiting for %d "
2310 "outstanding queries to respond",
2311 iq->num_current_queries);
2312 qstate->ext_state[id] = module_wait_reply;
2313 }
2314 }
2315
2316 /**
2317 * This is the request event state where the request will be sent to one of
2318 * its current query targets. This state also handles issuing target lookup
2319 * queries for missing target IP addresses. Queries typically iterate on
2320 * this state, both when they are just trying different targets for a given
2321 * delegation point, and when they change delegation points. This state
2322 * roughly corresponds to RFC 1034 algorithm steps 3 and 4.
2323 *
2324 * @param qstate: query state.
2325 * @param iq: iterator query state.
2326 * @param ie: iterator shared global environment.
2327 * @param id: module id.
2328 * @return true if the event requires more request processing immediately,
2329 * false if not. This state only returns true when it is generating
2330 * a SERVFAIL response because the query has hit a dead end.
2331 */
2332 static int
processQueryTargets(struct module_qstate * qstate,struct iter_qstate * iq,struct iter_env * ie,int id)2333 processQueryTargets(struct module_qstate* qstate, struct iter_qstate* iq,
2334 struct iter_env* ie, int id)
2335 {
2336 int tf_policy;
2337 struct delegpt_addr* target;
2338 struct outbound_entry* outq;
2339 struct sockaddr_storage real_addr;
2340 socklen_t real_addrlen;
2341 int auth_fallback = 0;
2342 uint8_t* qout_orig = NULL;
2343 size_t qout_orig_len = 0;
2344 int sq_check_ratelimit = 1;
2345 int sq_was_ratelimited = 0;
2346 int can_do_promisc = 0;
2347
2348 /* NOTE: a request will encounter this state for each target it
2349 * needs to send a query to. That is, at least one per referral,
2350 * more if some targets timeout or return throwaway answers. */
2351
2352 log_query_info(VERB_QUERY, "processQueryTargets:", &qstate->qinfo);
2353 verbose(VERB_ALGO, "processQueryTargets: targetqueries %d, "
2354 "currentqueries %d sentcount %d", iq->num_target_queries,
2355 iq->num_current_queries, iq->sent_count);
2356
2357 /* Make sure that we haven't run away */
2358 if(iq->referral_count > MAX_REFERRAL_COUNT) {
2359 verbose(VERB_QUERY, "request has exceeded the maximum "
2360 "number of referrrals with %d", iq->referral_count);
2361 errinf(qstate, "exceeded the maximum of referrals");
2362 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2363 }
2364 if(iq->sent_count > ie->max_sent_count) {
2365 verbose(VERB_QUERY, "request has exceeded the maximum "
2366 "number of sends with %d", iq->sent_count);
2367 errinf(qstate, "exceeded the maximum number of sends");
2368 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2369 }
2370
2371 /* Check if we reached MAX_TARGET_NX limit without a fallback activation. */
2372 if(iq->target_count && !*iq->nxns_dp &&
2373 iq->target_count[TARGET_COUNT_NX] > MAX_TARGET_NX) {
2374 struct delegpt_ns* ns;
2375 /* If we can wait for resolution, do so. */
2376 if(iq->num_target_queries>0 || iq->num_current_queries>0) {
2377 check_waiting_queries(iq, qstate, id);
2378 return 0;
2379 }
2380 verbose(VERB_ALGO, "request has exceeded the maximum "
2381 "number of nxdomain nameserver lookups (%d) with %d",
2382 MAX_TARGET_NX, iq->target_count[TARGET_COUNT_NX]);
2383 /* Check for dp because we require one below */
2384 if(!iq->dp) {
2385 verbose(VERB_QUERY, "Failed to get a delegation, "
2386 "giving up");
2387 errinf(qstate, "failed to get a delegation (eg. prime "
2388 "failure)");
2389 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2390 }
2391 /* We reached the limit but we already have parent side
2392 * information; stop resolution */
2393 if(iq->dp->has_parent_side_NS) {
2394 verbose(VERB_ALGO, "parent-side information is "
2395 "already present for the delegation point, no "
2396 "fallback possible");
2397 errinf(qstate, "exceeded the maximum nameserver nxdomains");
2398 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2399 }
2400 verbose(VERB_ALGO, "initiating parent-side fallback for "
2401 "nxdomain nameserver lookups");
2402 /* Mark all the current NSes as resolved to allow for parent
2403 * fallback */
2404 for(ns=iq->dp->nslist; ns; ns=ns->next) {
2405 ns->resolved = 1;
2406 }
2407 /* Note the delegation point that triggered the NXNS fallback;
2408 * no reason for shared queries to keep trying there.
2409 * This also marks the fallback activation. */
2410 *iq->nxns_dp = malloc(iq->dp->namelen);
2411 if(!*iq->nxns_dp) {
2412 verbose(VERB_ALGO, "out of memory while initiating "
2413 "fallback");
2414 errinf(qstate, "exceeded the maximum nameserver "
2415 "nxdomains (malloc)");
2416 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2417 }
2418 memcpy(*iq->nxns_dp, iq->dp->name, iq->dp->namelen);
2419 } else if(iq->target_count && *iq->nxns_dp) {
2420 /* Handle the NXNS fallback case. */
2421 /* If we can wait for resolution, do so. */
2422 if(iq->num_target_queries>0 || iq->num_current_queries>0) {
2423 check_waiting_queries(iq, qstate, id);
2424 return 0;
2425 }
2426 /* Check for dp because we require one below */
2427 if(!iq->dp) {
2428 verbose(VERB_QUERY, "Failed to get a delegation, "
2429 "giving up");
2430 errinf(qstate, "failed to get a delegation (eg. prime "
2431 "failure)");
2432 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2433 }
2434
2435 if(iq->target_count[TARGET_COUNT_NX] > MAX_TARGET_NX_FALLBACK) {
2436 verbose(VERB_ALGO, "request has exceeded the maximum "
2437 "number of fallback nxdomain nameserver "
2438 "lookups (%d) with %d", MAX_TARGET_NX_FALLBACK,
2439 iq->target_count[TARGET_COUNT_NX]);
2440 errinf(qstate, "exceeded the maximum nameserver nxdomains");
2441 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2442 }
2443
2444 if(!iq->dp->has_parent_side_NS) {
2445 struct delegpt_ns* ns;
2446 if(!dname_canonical_compare(*iq->nxns_dp, iq->dp->name)) {
2447 verbose(VERB_ALGO, "this delegation point "
2448 "initiated the fallback, marking the "
2449 "nslist as resolved");
2450 for(ns=iq->dp->nslist; ns; ns=ns->next) {
2451 ns->resolved = 1;
2452 }
2453 }
2454 }
2455 }
2456
2457 /* Make sure we have a delegation point, otherwise priming failed
2458 * or another failure occurred */
2459 if(!iq->dp) {
2460 verbose(VERB_QUERY, "Failed to get a delegation, giving up");
2461 errinf(qstate, "failed to get a delegation (eg. prime failure)");
2462 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2463 }
2464 if(!ie->supports_ipv6)
2465 delegpt_no_ipv6(iq->dp);
2466 if(!ie->supports_ipv4 && !ie->use_nat64)
2467 delegpt_no_ipv4(iq->dp);
2468 delegpt_log(VERB_ALGO, iq->dp);
2469
2470 if(iq->num_current_queries>0) {
2471 /* already busy answering a query, this restart is because
2472 * more delegpt addrs became available, wait for existing
2473 * query. */
2474 verbose(VERB_ALGO, "woke up, but wait for outstanding query");
2475 qstate->ext_state[id] = module_wait_reply;
2476 return 0;
2477 }
2478
2479 if(iq->minimisation_state == INIT_MINIMISE_STATE
2480 && !(iq->chase_flags & BIT_RD)) {
2481 /* (Re)set qinfo_out to (new) delegation point, except when
2482 * qinfo_out is already a subdomain of dp. This happens when
2483 * increasing by more than one label at once (QNAMEs with more
2484 * than MAX_MINIMISE_COUNT labels). */
2485 if(!(iq->qinfo_out.qname_len
2486 && dname_subdomain_c(iq->qchase.qname,
2487 iq->qinfo_out.qname)
2488 && dname_subdomain_c(iq->qinfo_out.qname,
2489 iq->dp->name))) {
2490 iq->qinfo_out.qname = iq->dp->name;
2491 iq->qinfo_out.qname_len = iq->dp->namelen;
2492 iq->qinfo_out.qtype = LDNS_RR_TYPE_A;
2493 iq->qinfo_out.qclass = iq->qchase.qclass;
2494 iq->qinfo_out.local_alias = NULL;
2495 iq->minimise_count = 0;
2496 }
2497
2498 iq->minimisation_state = MINIMISE_STATE;
2499 }
2500 if(iq->minimisation_state == MINIMISE_STATE) {
2501 int qchaselabs = dname_count_labels(iq->qchase.qname);
2502 int labdiff = qchaselabs -
2503 dname_count_labels(iq->qinfo_out.qname);
2504
2505 qout_orig = iq->qinfo_out.qname;
2506 qout_orig_len = iq->qinfo_out.qname_len;
2507 iq->qinfo_out.qname = iq->qchase.qname;
2508 iq->qinfo_out.qname_len = iq->qchase.qname_len;
2509 iq->minimise_count++;
2510 iq->timeout_count = 0;
2511
2512 iter_dec_attempts(iq->dp, 1, ie->outbound_msg_retry);
2513
2514 /* Limit number of iterations for QNAMEs with more
2515 * than MAX_MINIMISE_COUNT labels. Send first MINIMISE_ONE_LAB
2516 * labels of QNAME always individually.
2517 */
2518 if(qchaselabs > MAX_MINIMISE_COUNT && labdiff > 1 &&
2519 iq->minimise_count > MINIMISE_ONE_LAB) {
2520 if(iq->minimise_count < MAX_MINIMISE_COUNT) {
2521 int multilabs = qchaselabs - 1 -
2522 MINIMISE_ONE_LAB;
2523 int extralabs = multilabs /
2524 MINIMISE_MULTIPLE_LABS;
2525
2526 if (MAX_MINIMISE_COUNT - iq->minimise_count >=
2527 multilabs % MINIMISE_MULTIPLE_LABS)
2528 /* Default behaviour is to add 1 label
2529 * every iteration. Therefore, decrement
2530 * the extralabs by 1 */
2531 extralabs--;
2532 if (extralabs < labdiff)
2533 labdiff -= extralabs;
2534 else
2535 labdiff = 1;
2536 }
2537 /* Last minimised iteration, send all labels with
2538 * QTYPE=NS */
2539 else
2540 labdiff = 1;
2541 }
2542
2543 if(labdiff > 1) {
2544 verbose(VERB_QUERY, "removing %d labels", labdiff-1);
2545 dname_remove_labels(&iq->qinfo_out.qname,
2546 &iq->qinfo_out.qname_len,
2547 labdiff-1);
2548 }
2549 if(labdiff < 1 || (labdiff < 2
2550 && (iq->qchase.qtype == LDNS_RR_TYPE_DS
2551 || iq->qchase.qtype == LDNS_RR_TYPE_A)))
2552 /* Stop minimising this query, resolve "as usual" */
2553 iq->minimisation_state = DONOT_MINIMISE_STATE;
2554 else if(!qstate->no_cache_lookup) {
2555 struct dns_msg* msg = dns_cache_lookup(qstate->env,
2556 iq->qinfo_out.qname, iq->qinfo_out.qname_len,
2557 iq->qinfo_out.qtype, iq->qinfo_out.qclass,
2558 qstate->query_flags, qstate->region,
2559 qstate->env->scratch, 0, iq->dp->name,
2560 iq->dp->namelen);
2561 if(msg && FLAGS_GET_RCODE(msg->rep->flags) ==
2562 LDNS_RCODE_NOERROR)
2563 /* no need to send query if it is already
2564 * cached as NOERROR */
2565 return 1;
2566 if(msg && FLAGS_GET_RCODE(msg->rep->flags) ==
2567 LDNS_RCODE_NXDOMAIN &&
2568 qstate->env->need_to_validate &&
2569 qstate->env->cfg->harden_below_nxdomain) {
2570 if(msg->rep->security == sec_status_secure) {
2571 iq->response = msg;
2572 return final_state(iq);
2573 }
2574 if(msg->rep->security == sec_status_unchecked) {
2575 struct module_qstate* subq = NULL;
2576 if(!generate_sub_request(
2577 iq->qinfo_out.qname,
2578 iq->qinfo_out.qname_len,
2579 iq->qinfo_out.qtype,
2580 iq->qinfo_out.qclass,
2581 qstate, id, iq,
2582 INIT_REQUEST_STATE,
2583 FINISHED_STATE, &subq, 1, 1))
2584 verbose(VERB_ALGO,
2585 "could not validate NXDOMAIN "
2586 "response");
2587 }
2588 }
2589 if(msg && FLAGS_GET_RCODE(msg->rep->flags) ==
2590 LDNS_RCODE_NXDOMAIN) {
2591 /* return and add a label in the next
2592 * minimisation iteration.
2593 */
2594 return 1;
2595 }
2596 }
2597 }
2598 if(iq->minimisation_state == SKIP_MINIMISE_STATE) {
2599 if(iq->timeout_count < MAX_MINIMISE_TIMEOUT_COUNT)
2600 /* Do not increment qname, continue incrementing next
2601 * iteration */
2602 iq->minimisation_state = MINIMISE_STATE;
2603 else if(!qstate->env->cfg->qname_minimisation_strict)
2604 /* Too many time-outs detected for this QNAME and QTYPE.
2605 * We give up, disable QNAME minimisation. */
2606 iq->minimisation_state = DONOT_MINIMISE_STATE;
2607 }
2608 if(iq->minimisation_state == DONOT_MINIMISE_STATE)
2609 iq->qinfo_out = iq->qchase;
2610
2611 /* now find an answer to this query */
2612 /* see if authority zones have an answer */
2613 /* now we know the dp, we can check the auth zone for locally hosted
2614 * contents */
2615 if(!iq->auth_zone_avoid && qstate->blacklist) {
2616 if(auth_zones_can_fallback(qstate->env->auth_zones,
2617 iq->dp->name, iq->dp->namelen, iq->qinfo_out.qclass)) {
2618 /* if cache is blacklisted and this zone allows us
2619 * to fallback to the internet, then do so, and
2620 * fetch results from the internet servers */
2621 iq->auth_zone_avoid = 1;
2622 }
2623 }
2624 if(iq->auth_zone_avoid) {
2625 iq->auth_zone_avoid = 0;
2626 auth_fallback = 1;
2627 } else if(auth_zones_lookup(qstate->env->auth_zones, &iq->qinfo_out,
2628 qstate->region, &iq->response, &auth_fallback, iq->dp->name,
2629 iq->dp->namelen)) {
2630 /* use this as a response to be processed by the iterator */
2631 if(verbosity >= VERB_ALGO) {
2632 log_dns_msg("msg from auth zone",
2633 &iq->response->qinfo, iq->response->rep);
2634 }
2635 if((iq->chase_flags&BIT_RD) && !(iq->response->rep->flags&BIT_AA)) {
2636 verbose(VERB_ALGO, "forwarder, ignoring referral from auth zone");
2637 } else {
2638 lock_rw_wrlock(&qstate->env->auth_zones->lock);
2639 qstate->env->auth_zones->num_query_up++;
2640 lock_rw_unlock(&qstate->env->auth_zones->lock);
2641 iq->num_current_queries++;
2642 iq->chase_to_rd = 0;
2643 iq->dnssec_lame_query = 0;
2644 iq->auth_zone_response = 1;
2645 return next_state(iq, QUERY_RESP_STATE);
2646 }
2647 }
2648 iq->auth_zone_response = 0;
2649 if(auth_fallback == 0) {
2650 /* like we got servfail from the auth zone lookup, and
2651 * no internet fallback */
2652 verbose(VERB_ALGO, "auth zone lookup failed, no fallback,"
2653 " servfail");
2654 errinf(qstate, "auth zone lookup failed, fallback is off");
2655 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2656 }
2657 if(iq->dp->auth_dp) {
2658 /* we wanted to fallback, but had no delegpt, only the
2659 * auth zone generated delegpt, create an actual one */
2660 iq->auth_zone_avoid = 1;
2661 return next_state(iq, INIT_REQUEST_STATE);
2662 }
2663 /* but mostly, fallback==1 (like, when no such auth zone exists)
2664 * and we continue with lookups */
2665
2666 tf_policy = 0;
2667 /* < not <=, because although the array is large enough for <=, the
2668 * generated query will immediately be discarded due to depth and
2669 * that servfail is cached, which is not good as opportunism goes. */
2670 if(iq->depth < ie->max_dependency_depth
2671 && iq->num_target_queries == 0
2672 && (!iq->target_count || iq->target_count[TARGET_COUNT_NX]==0)
2673 && iq->sent_count < TARGET_FETCH_STOP) {
2674 can_do_promisc = 1;
2675 }
2676 /* if the mesh query list is full, then do not waste cpu and sockets to
2677 * fetch promiscuous targets. They can be looked up when needed. */
2678 if(can_do_promisc && !mesh_jostle_exceeded(qstate->env->mesh)) {
2679 tf_policy = ie->target_fetch_policy[iq->depth];
2680 }
2681
2682 /* if in 0x20 fallback get as many targets as possible */
2683 if(iq->caps_fallback) {
2684 int extra = 0;
2685 size_t naddr, nres, navail;
2686 if(!query_for_targets(qstate, iq, ie, id, -1, &extra)) {
2687 errinf(qstate, "could not fetch nameservers for 0x20 fallback");
2688 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2689 }
2690 iq->num_target_queries += extra;
2691 target_count_increase(iq, extra);
2692 if(iq->num_target_queries > 0) {
2693 /* wait to get all targets, we want to try em */
2694 verbose(VERB_ALGO, "wait for all targets for fallback");
2695 qstate->ext_state[id] = module_wait_reply;
2696 /* undo qname minimise step because we'll get back here
2697 * to do it again */
2698 if(qout_orig && iq->minimise_count > 0) {
2699 iq->minimise_count--;
2700 iq->qinfo_out.qname = qout_orig;
2701 iq->qinfo_out.qname_len = qout_orig_len;
2702 }
2703 return 0;
2704 }
2705 /* did we do enough fallback queries already? */
2706 delegpt_count_addr(iq->dp, &naddr, &nres, &navail);
2707 /* the current caps_server is the number of fallbacks sent.
2708 * the original query is one that matched too, so we have
2709 * caps_server+1 number of matching queries now */
2710 if(iq->caps_server+1 >= naddr*3 ||
2711 iq->caps_server*2+2 >= (size_t)ie->max_sent_count) {
2712 /* *2 on sentcount check because ipv6 may fail */
2713 /* we're done, process the response */
2714 verbose(VERB_ALGO, "0x20 fallback had %d responses "
2715 "match for %d wanted, done.",
2716 (int)iq->caps_server+1, (int)naddr*3);
2717 iq->response = iq->caps_response;
2718 iq->caps_fallback = 0;
2719 iter_dec_attempts(iq->dp, 3, ie->outbound_msg_retry); /* space for fallback */
2720 iq->num_current_queries++; /* RespState decrements it*/
2721 iq->referral_count++; /* make sure we don't loop */
2722 iq->sent_count = 0;
2723 iq->dp_target_count = 0;
2724 iq->state = QUERY_RESP_STATE;
2725 return 1;
2726 }
2727 verbose(VERB_ALGO, "0x20 fallback number %d",
2728 (int)iq->caps_server);
2729
2730 /* if there is a policy to fetch missing targets
2731 * opportunistically, do it. we rely on the fact that once a
2732 * query (or queries) for a missing name have been issued,
2733 * they will not show up again. */
2734 } else if(tf_policy != 0) {
2735 int extra = 0;
2736 verbose(VERB_ALGO, "attempt to get extra %d targets",
2737 tf_policy);
2738 (void)query_for_targets(qstate, iq, ie, id, tf_policy, &extra);
2739 /* errors ignored, these targets are not strictly necessary for
2740 * this result, we do not have to reply with SERVFAIL */
2741 iq->num_target_queries += extra;
2742 target_count_increase(iq, extra);
2743 }
2744
2745 /* Add the current set of unused targets to our queue. */
2746 delegpt_add_unused_targets(iq->dp);
2747
2748 if(qstate->env->auth_zones) {
2749 /* apply rpz triggers at query time */
2750 struct dns_msg* forged_response = rpz_callback_from_iterator_module(qstate, iq);
2751 if(forged_response != NULL) {
2752 qstate->ext_state[id] = module_finished;
2753 qstate->return_rcode = LDNS_RCODE_NOERROR;
2754 qstate->return_msg = forged_response;
2755 iq->response = forged_response;
2756 next_state(iq, FINISHED_STATE);
2757 if(!iter_prepend(iq, qstate->return_msg, qstate->region)) {
2758 log_err("rpz: prepend rrsets: out of memory");
2759 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2760 }
2761 return 0;
2762 }
2763 }
2764
2765 /* Select the next usable target, filtering out unsuitable targets. */
2766 target = iter_server_selection(ie, qstate->env, iq->dp,
2767 iq->dp->name, iq->dp->namelen, iq->qchase.qtype,
2768 &iq->dnssec_lame_query, &iq->chase_to_rd,
2769 iq->num_target_queries, qstate->blacklist,
2770 qstate->prefetch_leeway);
2771
2772 /* If no usable target was selected... */
2773 if(!target) {
2774 /* Here we distinguish between three states: generate a new
2775 * target query, just wait, or quit (with a SERVFAIL).
2776 * We have the following information: number of active
2777 * target queries, number of active current queries,
2778 * the presence of missing targets at this delegation
2779 * point, and the given query target policy. */
2780
2781 /* Check for the wait condition. If this is true, then
2782 * an action must be taken. */
2783 if(iq->num_target_queries==0 && iq->num_current_queries==0) {
2784 /* If there is nothing to wait for, then we need
2785 * to distinguish between generating (a) new target
2786 * query, or failing. */
2787 if(delegpt_count_missing_targets(iq->dp, NULL) > 0) {
2788 int qs = 0;
2789 verbose(VERB_ALGO, "querying for next "
2790 "missing target");
2791 if(!query_for_targets(qstate, iq, ie, id,
2792 1, &qs)) {
2793 errinf(qstate, "could not fetch nameserver");
2794 errinf_dname(qstate, "at zone", iq->dp->name);
2795 return error_response(qstate, id,
2796 LDNS_RCODE_SERVFAIL);
2797 }
2798 if(qs == 0 &&
2799 delegpt_count_missing_targets(iq->dp, NULL) == 0){
2800 /* it looked like there were missing
2801 * targets, but they did not turn up.
2802 * Try the bad choices again (if any),
2803 * when we get back here missing==0,
2804 * so this is not a loop. */
2805 return 1;
2806 }
2807 iq->num_target_queries += qs;
2808 target_count_increase(iq, qs);
2809 }
2810 /* Since a target query might have been made, we
2811 * need to check again. */
2812 if(iq->num_target_queries == 0) {
2813 /* if in capsforid fallback, instead of last
2814 * resort, we agree with the current reply
2815 * we have (if any) (our count of addrs bad)*/
2816 if(iq->caps_fallback && iq->caps_reply) {
2817 /* we're done, process the response */
2818 verbose(VERB_ALGO, "0x20 fallback had %d responses, "
2819 "but no more servers except "
2820 "last resort, done.",
2821 (int)iq->caps_server+1);
2822 iq->response = iq->caps_response;
2823 iq->caps_fallback = 0;
2824 iter_dec_attempts(iq->dp, 3, ie->outbound_msg_retry); /* space for fallback */
2825 iq->num_current_queries++; /* RespState decrements it*/
2826 iq->referral_count++; /* make sure we don't loop */
2827 iq->sent_count = 0;
2828 iq->dp_target_count = 0;
2829 iq->state = QUERY_RESP_STATE;
2830 return 1;
2831 }
2832 return processLastResort(qstate, iq, ie, id);
2833 }
2834 }
2835
2836 /* otherwise, we have no current targets, so submerge
2837 * until one of the target or direct queries return. */
2838 verbose(VERB_ALGO, "no current targets");
2839 check_waiting_queries(iq, qstate, id);
2840 /* undo qname minimise step because we'll get back here
2841 * to do it again */
2842 if(qout_orig && iq->minimise_count > 0) {
2843 iq->minimise_count--;
2844 iq->qinfo_out.qname = qout_orig;
2845 iq->qinfo_out.qname_len = qout_orig_len;
2846 }
2847 return 0;
2848 }
2849
2850 /* We have a target. We could have created promiscuous target
2851 * queries but we are currently under pressure (mesh_jostle_exceeded).
2852 * If we are configured to allow promiscuous target queries and haven't
2853 * gone out to the network for a target query for this delegation, then
2854 * it is possible to slip in a promiscuous one with a 1/10 chance. */
2855 if(can_do_promisc && tf_policy == 0 && iq->depth == 0
2856 && iq->depth < ie->max_dependency_depth
2857 && ie->target_fetch_policy[iq->depth] != 0
2858 && iq->dp_target_count == 0
2859 && !ub_random_max(qstate->env->rnd, 10)) {
2860 int extra = 0;
2861 verbose(VERB_ALGO, "available target exists in cache but "
2862 "attempt to get extra 1 target");
2863 (void)query_for_targets(qstate, iq, ie, id, 1, &extra);
2864 /* errors ignored, these targets are not strictly necessary for
2865 * this result, we do not have to reply with SERVFAIL */
2866 if(extra > 0) {
2867 iq->num_target_queries += extra;
2868 target_count_increase(iq, extra);
2869 check_waiting_queries(iq, qstate, id);
2870 /* undo qname minimise step because we'll get back here
2871 * to do it again */
2872 if(qout_orig && iq->minimise_count > 0) {
2873 iq->minimise_count--;
2874 iq->qinfo_out.qname = qout_orig;
2875 iq->qinfo_out.qname_len = qout_orig_len;
2876 }
2877 return 0;
2878 }
2879 }
2880
2881 /* Do not check ratelimit for forwarding queries or if we already got a
2882 * pass. */
2883 sq_check_ratelimit = (!(iq->chase_flags & BIT_RD) && !iq->ratelimit_ok);
2884 /* We have a valid target. */
2885 if(verbosity >= VERB_QUERY) {
2886 log_query_info(VERB_QUERY, "sending query:", &iq->qinfo_out);
2887 log_name_addr(VERB_QUERY, "sending to target:", iq->dp->name,
2888 &target->addr, target->addrlen);
2889 verbose(VERB_ALGO, "dnssec status: %s%s",
2890 iq->dnssec_expected?"expected": "not expected",
2891 iq->dnssec_lame_query?" but lame_query anyway": "");
2892 }
2893
2894 real_addr = target->addr;
2895 real_addrlen = target->addrlen;
2896
2897 if(ie->use_nat64 && target->addr.ss_family == AF_INET) {
2898 addr_to_nat64(&target->addr, &ie->nat64_prefix_addr,
2899 ie->nat64_prefix_addrlen, ie->nat64_prefix_net,
2900 &real_addr, &real_addrlen);
2901 log_name_addr(VERB_QUERY, "applied NAT64:",
2902 iq->dp->name, &real_addr, real_addrlen);
2903 }
2904
2905 fptr_ok(fptr_whitelist_modenv_send_query(qstate->env->send_query));
2906 outq = (*qstate->env->send_query)(&iq->qinfo_out,
2907 iq->chase_flags | (iq->chase_to_rd?BIT_RD:0),
2908 /* unset CD if to forwarder(RD set) and not dnssec retry
2909 * (blacklist nonempty) and no trust-anchors are configured
2910 * above the qname or on the first attempt when dnssec is on */
2911 (qstate->env->cfg->disable_edns_do?0:EDNS_DO)|
2912 ((iq->chase_to_rd||(iq->chase_flags&BIT_RD)!=0)&&
2913 !qstate->blacklist&&(!iter_qname_indicates_dnssec(qstate->env,
2914 &iq->qinfo_out)||target->attempts==1)?0:BIT_CD),
2915 iq->dnssec_expected, iq->caps_fallback || is_caps_whitelisted(
2916 ie, iq), sq_check_ratelimit, &real_addr, real_addrlen,
2917 iq->dp->name, iq->dp->namelen,
2918 (iq->dp->tcp_upstream || qstate->env->cfg->tcp_upstream),
2919 (iq->dp->ssl_upstream || qstate->env->cfg->ssl_upstream),
2920 target->tls_auth_name, qstate, &sq_was_ratelimited);
2921 if(!outq) {
2922 if(sq_was_ratelimited) {
2923 lock_basic_lock(&ie->queries_ratelimit_lock);
2924 ie->num_queries_ratelimited++;
2925 lock_basic_unlock(&ie->queries_ratelimit_lock);
2926 verbose(VERB_ALGO, "query exceeded ratelimits");
2927 qstate->was_ratelimited = 1;
2928 errinf_dname(qstate, "exceeded ratelimit for zone",
2929 iq->dp->name);
2930 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
2931 }
2932 log_addr(VERB_QUERY, "error sending query to auth server",
2933 &real_addr, real_addrlen);
2934 if(qstate->env->cfg->qname_minimisation)
2935 iq->minimisation_state = SKIP_MINIMISE_STATE;
2936 return next_state(iq, QUERYTARGETS_STATE);
2937 }
2938 outbound_list_insert(&iq->outlist, outq);
2939 iq->num_current_queries++;
2940 iq->sent_count++;
2941 qstate->ext_state[id] = module_wait_reply;
2942
2943 return 0;
2944 }
2945
2946 /** find NS rrset in given list */
2947 static struct ub_packed_rrset_key*
find_NS(struct reply_info * rep,size_t from,size_t to)2948 find_NS(struct reply_info* rep, size_t from, size_t to)
2949 {
2950 size_t i;
2951 for(i=from; i<to; i++) {
2952 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NS)
2953 return rep->rrsets[i];
2954 }
2955 return NULL;
2956 }
2957
2958
2959 /**
2960 * Process the query response. All queries end up at this state first. This
2961 * process generally consists of analyzing the response and routing the
2962 * event to the next state (either bouncing it back to a request state, or
2963 * terminating the processing for this event).
2964 *
2965 * @param qstate: query state.
2966 * @param iq: iterator query state.
2967 * @param ie: iterator shared global environment.
2968 * @param id: module id.
2969 * @return true if the event requires more immediate processing, false if
2970 * not. This is generally only true when forwarding the request to
2971 * the final state (i.e., on answer).
2972 */
2973 static int
processQueryResponse(struct module_qstate * qstate,struct iter_qstate * iq,struct iter_env * ie,int id)2974 processQueryResponse(struct module_qstate* qstate, struct iter_qstate* iq,
2975 struct iter_env* ie, int id)
2976 {
2977 int dnsseclame = 0, origtypecname = 0, orig_empty_nodata_found;
2978 enum response_type type;
2979
2980 iq->num_current_queries--;
2981
2982 if(!inplace_cb_query_response_call(qstate->env, qstate, iq->response))
2983 log_err("unable to call query_response callback");
2984
2985 if(iq->response == NULL) {
2986 /* Don't increment qname when QNAME minimisation is enabled */
2987 if(qstate->env->cfg->qname_minimisation) {
2988 iq->minimisation_state = SKIP_MINIMISE_STATE;
2989 }
2990 iq->timeout_count++;
2991 iq->chase_to_rd = 0;
2992 iq->dnssec_lame_query = 0;
2993 verbose(VERB_ALGO, "query response was timeout");
2994 return next_state(iq, QUERYTARGETS_STATE);
2995 }
2996 iq->timeout_count = 0;
2997 orig_empty_nodata_found = iq->empty_nodata_found;
2998 type = response_type_from_server(
2999 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
3000 iq->response, &iq->qinfo_out, iq->dp, &iq->empty_nodata_found);
3001 iq->chase_to_rd = 0;
3002 /* remove TC flag, if this is erroneously set by TCP upstream */
3003 iq->response->rep->flags &= ~BIT_TC;
3004 if(orig_empty_nodata_found != iq->empty_nodata_found &&
3005 iq->empty_nodata_found < EMPTY_NODATA_RETRY_COUNT) {
3006 /* try to search at another server */
3007 if(qstate->reply) {
3008 struct delegpt_addr* a = delegpt_find_addr(
3009 iq->dp, &qstate->reply->remote_addr,
3010 qstate->reply->remote_addrlen);
3011 /* make selection disprefer it */
3012 if(a) a->lame = 1;
3013 }
3014 return next_state(iq, QUERYTARGETS_STATE);
3015 }
3016 if(type == RESPONSE_TYPE_REFERRAL && (iq->chase_flags&BIT_RD) &&
3017 !iq->auth_zone_response) {
3018 /* When forwarding (RD bit is set), we handle referrals
3019 * differently. No queries should be sent elsewhere */
3020 type = RESPONSE_TYPE_ANSWER;
3021 }
3022 if(!qstate->env->cfg->disable_dnssec_lame_check && iq->dnssec_expected
3023 && !iq->dnssec_lame_query &&
3024 !(iq->chase_flags&BIT_RD)
3025 && iq->sent_count < DNSSEC_LAME_DETECT_COUNT
3026 && type != RESPONSE_TYPE_LAME
3027 && type != RESPONSE_TYPE_REC_LAME
3028 && type != RESPONSE_TYPE_THROWAWAY
3029 && type != RESPONSE_TYPE_UNTYPED) {
3030 /* a possible answer, see if it is missing DNSSEC */
3031 /* but not when forwarding, so we dont mark fwder lame */
3032 if(!iter_msg_has_dnssec(iq->response)) {
3033 /* Mark this address as dnsseclame in this dp,
3034 * because that will make serverselection disprefer
3035 * it, but also, once it is the only final option,
3036 * use dnssec-lame-bypass if it needs to query there.*/
3037 if(qstate->reply) {
3038 struct delegpt_addr* a = delegpt_find_addr(
3039 iq->dp, &qstate->reply->remote_addr,
3040 qstate->reply->remote_addrlen);
3041 if(a) a->dnsseclame = 1;
3042 }
3043 /* test the answer is from the zone we expected,
3044 * otherwise, (due to parent,child on same server), we
3045 * might mark the server,zone lame inappropriately */
3046 if(!iter_msg_from_zone(iq->response, iq->dp, type,
3047 iq->qchase.qclass))
3048 qstate->reply = NULL;
3049 type = RESPONSE_TYPE_LAME;
3050 dnsseclame = 1;
3051 }
3052 } else iq->dnssec_lame_query = 0;
3053 /* see if referral brings us close to the target */
3054 if(type == RESPONSE_TYPE_REFERRAL) {
3055 struct ub_packed_rrset_key* ns = find_NS(
3056 iq->response->rep, iq->response->rep->an_numrrsets,
3057 iq->response->rep->an_numrrsets
3058 + iq->response->rep->ns_numrrsets);
3059 if(!ns) ns = find_NS(iq->response->rep, 0,
3060 iq->response->rep->an_numrrsets);
3061 if(!ns || !dname_strict_subdomain_c(ns->rk.dname, iq->dp->name)
3062 || !dname_subdomain_c(iq->qchase.qname, ns->rk.dname)){
3063 verbose(VERB_ALGO, "bad referral, throwaway");
3064 type = RESPONSE_TYPE_THROWAWAY;
3065 } else
3066 iter_scrub_ds(iq->response, ns, iq->dp->name);
3067 } else iter_scrub_ds(iq->response, NULL, NULL);
3068 if(type == RESPONSE_TYPE_THROWAWAY &&
3069 FLAGS_GET_RCODE(iq->response->rep->flags) == LDNS_RCODE_YXDOMAIN) {
3070 /* YXDOMAIN is a permanent error, no need to retry */
3071 type = RESPONSE_TYPE_ANSWER;
3072 }
3073 if(type == RESPONSE_TYPE_CNAME)
3074 origtypecname = 1;
3075 if(type == RESPONSE_TYPE_CNAME && iq->response->rep->an_numrrsets >= 1
3076 && ntohs(iq->response->rep->rrsets[0]->rk.type) == LDNS_RR_TYPE_DNAME) {
3077 uint8_t* sname = NULL;
3078 size_t snamelen = 0;
3079 get_cname_target(iq->response->rep->rrsets[0], &sname,
3080 &snamelen);
3081 if(snamelen && dname_subdomain_c(sname, iq->response->rep->rrsets[0]->rk.dname)) {
3082 /* DNAME to a subdomain loop; do not recurse */
3083 type = RESPONSE_TYPE_ANSWER;
3084 }
3085 } else if(type == RESPONSE_TYPE_CNAME &&
3086 iq->qchase.qtype == LDNS_RR_TYPE_CNAME &&
3087 iq->minimisation_state == MINIMISE_STATE &&
3088 query_dname_compare(iq->qchase.qname, iq->qinfo_out.qname) == 0) {
3089 /* The minimised query for full QTYPE and hidden QTYPE can be
3090 * classified as CNAME response type, even when the original
3091 * QTYPE=CNAME. This should be treated as answer response type.
3092 */
3093 type = RESPONSE_TYPE_ANSWER;
3094 }
3095
3096 /* handle each of the type cases */
3097 if(type == RESPONSE_TYPE_ANSWER) {
3098 /* ANSWER type responses terminate the query algorithm,
3099 * so they sent on their */
3100 if(verbosity >= VERB_DETAIL) {
3101 verbose(VERB_DETAIL, "query response was %s",
3102 FLAGS_GET_RCODE(iq->response->rep->flags)
3103 ==LDNS_RCODE_NXDOMAIN?"NXDOMAIN ANSWER":
3104 (iq->response->rep->an_numrrsets?"ANSWER":
3105 "nodata ANSWER"));
3106 }
3107 /* if qtype is DS, check we have the right level of answer,
3108 * like grandchild answer but we need the middle, reject it */
3109 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
3110 && !(iq->chase_flags&BIT_RD)
3111 && iter_ds_toolow(iq->response, iq->dp)
3112 && iter_dp_cangodown(&iq->qchase, iq->dp)) {
3113 /* close down outstanding requests to be discarded */
3114 outbound_list_clear(&iq->outlist);
3115 iq->num_current_queries = 0;
3116 fptr_ok(fptr_whitelist_modenv_detach_subs(
3117 qstate->env->detach_subs));
3118 (*qstate->env->detach_subs)(qstate);
3119 iq->num_target_queries = 0;
3120 return processDSNSFind(qstate, iq, id);
3121 }
3122 if(!qstate->no_cache_store)
3123 iter_dns_store(qstate->env, &iq->response->qinfo,
3124 iq->response->rep,
3125 iq->qchase.qtype != iq->response->qinfo.qtype,
3126 qstate->prefetch_leeway,
3127 iq->dp&&iq->dp->has_parent_side_NS,
3128 qstate->region, qstate->query_flags,
3129 qstate->qstarttime);
3130 /* close down outstanding requests to be discarded */
3131 outbound_list_clear(&iq->outlist);
3132 iq->num_current_queries = 0;
3133 fptr_ok(fptr_whitelist_modenv_detach_subs(
3134 qstate->env->detach_subs));
3135 (*qstate->env->detach_subs)(qstate);
3136 iq->num_target_queries = 0;
3137 if(qstate->reply)
3138 sock_list_insert(&qstate->reply_origin,
3139 &qstate->reply->remote_addr,
3140 qstate->reply->remote_addrlen, qstate->region);
3141 if(iq->minimisation_state != DONOT_MINIMISE_STATE
3142 && !(iq->chase_flags & BIT_RD)) {
3143 if(FLAGS_GET_RCODE(iq->response->rep->flags) !=
3144 LDNS_RCODE_NOERROR) {
3145 if(qstate->env->cfg->qname_minimisation_strict) {
3146 if(FLAGS_GET_RCODE(iq->response->rep->flags) ==
3147 LDNS_RCODE_NXDOMAIN) {
3148 iter_scrub_nxdomain(iq->response);
3149 return final_state(iq);
3150 }
3151 return error_response(qstate, id,
3152 LDNS_RCODE_SERVFAIL);
3153 }
3154 /* Best effort qname-minimisation.
3155 * Stop minimising and send full query when
3156 * RCODE is not NOERROR. */
3157 iq->minimisation_state = DONOT_MINIMISE_STATE;
3158 }
3159 if(FLAGS_GET_RCODE(iq->response->rep->flags) ==
3160 LDNS_RCODE_NXDOMAIN && !origtypecname) {
3161 /* Stop resolving when NXDOMAIN is DNSSEC
3162 * signed. Based on assumption that nameservers
3163 * serving signed zones do not return NXDOMAIN
3164 * for empty-non-terminals. */
3165 /* If this response is actually a CNAME type,
3166 * the nxdomain rcode may not be for the qname,
3167 * and so it is not the final response. */
3168 if(iq->dnssec_expected)
3169 return final_state(iq);
3170 /* Make subrequest to validate intermediate
3171 * NXDOMAIN if harden-below-nxdomain is
3172 * enabled. */
3173 if(qstate->env->cfg->harden_below_nxdomain &&
3174 qstate->env->need_to_validate) {
3175 struct module_qstate* subq = NULL;
3176 log_query_info(VERB_QUERY,
3177 "schedule NXDOMAIN validation:",
3178 &iq->response->qinfo);
3179 if(!generate_sub_request(
3180 iq->response->qinfo.qname,
3181 iq->response->qinfo.qname_len,
3182 iq->response->qinfo.qtype,
3183 iq->response->qinfo.qclass,
3184 qstate, id, iq,
3185 INIT_REQUEST_STATE,
3186 FINISHED_STATE, &subq, 1, 1))
3187 verbose(VERB_ALGO,
3188 "could not validate NXDOMAIN "
3189 "response");
3190 }
3191 }
3192 return next_state(iq, QUERYTARGETS_STATE);
3193 }
3194 return final_state(iq);
3195 } else if(type == RESPONSE_TYPE_REFERRAL) {
3196 /* REFERRAL type responses get a reset of the
3197 * delegation point, and back to the QUERYTARGETS_STATE. */
3198 verbose(VERB_DETAIL, "query response was REFERRAL");
3199
3200 /* if hardened, only store referral if we asked for it */
3201 if(!qstate->no_cache_store &&
3202 (!qstate->env->cfg->harden_referral_path ||
3203 ( qstate->qinfo.qtype == LDNS_RR_TYPE_NS
3204 && (qstate->query_flags&BIT_RD)
3205 && !(qstate->query_flags&BIT_CD)
3206 /* we know that all other NS rrsets are scrubbed
3207 * away, thus on referral only one is left.
3208 * see if that equals the query name... */
3209 && ( /* auth section, but sometimes in answer section*/
3210 reply_find_rrset_section_ns(iq->response->rep,
3211 iq->qchase.qname, iq->qchase.qname_len,
3212 LDNS_RR_TYPE_NS, iq->qchase.qclass)
3213 || reply_find_rrset_section_an(iq->response->rep,
3214 iq->qchase.qname, iq->qchase.qname_len,
3215 LDNS_RR_TYPE_NS, iq->qchase.qclass)
3216 )
3217 ))) {
3218 /* Store the referral under the current query */
3219 /* no prefetch-leeway, since its not the answer */
3220 iter_dns_store(qstate->env, &iq->response->qinfo,
3221 iq->response->rep, 1, 0, 0, NULL, 0,
3222 qstate->qstarttime);
3223 if(iq->store_parent_NS)
3224 iter_store_parentside_NS(qstate->env,
3225 iq->response->rep);
3226 if(qstate->env->neg_cache)
3227 val_neg_addreferral(qstate->env->neg_cache,
3228 iq->response->rep, iq->dp->name);
3229 }
3230 /* store parent-side-in-zone-glue, if directly queried for */
3231 if(!qstate->no_cache_store && iq->query_for_pside_glue
3232 && !iq->pside_glue) {
3233 iq->pside_glue = reply_find_rrset(iq->response->rep,
3234 iq->qchase.qname, iq->qchase.qname_len,
3235 iq->qchase.qtype, iq->qchase.qclass);
3236 if(iq->pside_glue) {
3237 log_rrset_key(VERB_ALGO, "found parent-side "
3238 "glue", iq->pside_glue);
3239 iter_store_parentside_rrset(qstate->env,
3240 iq->pside_glue);
3241 }
3242 }
3243
3244 /* Reset the event state, setting the current delegation
3245 * point to the referral. */
3246 iq->deleg_msg = iq->response;
3247 iq->dp = delegpt_from_message(iq->response, qstate->region);
3248 if (qstate->env->cfg->qname_minimisation)
3249 iq->minimisation_state = INIT_MINIMISE_STATE;
3250 if(!iq->dp) {
3251 errinf(qstate, "malloc failure, for delegation point");
3252 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3253 }
3254 if(!cache_fill_missing(qstate->env, iq->qchase.qclass,
3255 qstate->region, iq->dp)) {
3256 errinf(qstate, "malloc failure, copy extra info into delegation point");
3257 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3258 }
3259 if(iq->store_parent_NS && query_dname_compare(iq->dp->name,
3260 iq->store_parent_NS->name) == 0)
3261 iter_merge_retry_counts(iq->dp, iq->store_parent_NS,
3262 ie->outbound_msg_retry);
3263 delegpt_log(VERB_ALGO, iq->dp);
3264 /* Count this as a referral. */
3265 iq->referral_count++;
3266 iq->sent_count = 0;
3267 iq->dp_target_count = 0;
3268 /* see if the next dp is a trust anchor, or a DS was sent
3269 * along, indicating dnssec is expected for next zone */
3270 iq->dnssec_expected = iter_indicates_dnssec(qstate->env,
3271 iq->dp, iq->response, iq->qchase.qclass);
3272 /* if dnssec, validating then also fetch the key for the DS */
3273 if(iq->dnssec_expected && qstate->env->cfg->prefetch_key &&
3274 !(qstate->query_flags&BIT_CD))
3275 generate_dnskey_prefetch(qstate, iq, id);
3276
3277 /* spawn off NS and addr to auth servers for the NS we just
3278 * got in the referral. This gets authoritative answer
3279 * (answer section trust level) rrset.
3280 * right after, we detach the subs, answer goes to cache. */
3281 if(qstate->env->cfg->harden_referral_path)
3282 generate_ns_check(qstate, iq, id);
3283
3284 /* stop current outstanding queries.
3285 * FIXME: should the outstanding queries be waited for and
3286 * handled? Say by a subquery that inherits the outbound_entry.
3287 */
3288 outbound_list_clear(&iq->outlist);
3289 iq->num_current_queries = 0;
3290 fptr_ok(fptr_whitelist_modenv_detach_subs(
3291 qstate->env->detach_subs));
3292 (*qstate->env->detach_subs)(qstate);
3293 iq->num_target_queries = 0;
3294 iq->response = NULL;
3295 iq->fail_addr_type = 0;
3296 verbose(VERB_ALGO, "cleared outbound list for next round");
3297 return next_state(iq, QUERYTARGETS_STATE);
3298 } else if(type == RESPONSE_TYPE_CNAME) {
3299 uint8_t* sname = NULL;
3300 size_t snamelen = 0;
3301 /* CNAME type responses get a query restart (i.e., get a
3302 * reset of the query state and go back to INIT_REQUEST_STATE).
3303 */
3304 verbose(VERB_DETAIL, "query response was CNAME");
3305 if(verbosity >= VERB_ALGO)
3306 log_dns_msg("cname msg", &iq->response->qinfo,
3307 iq->response->rep);
3308 /* if qtype is DS, check we have the right level of answer,
3309 * like grandchild answer but we need the middle, reject it */
3310 if(iq->qchase.qtype == LDNS_RR_TYPE_DS && !iq->dsns_point
3311 && !(iq->chase_flags&BIT_RD)
3312 && iter_ds_toolow(iq->response, iq->dp)
3313 && iter_dp_cangodown(&iq->qchase, iq->dp)) {
3314 outbound_list_clear(&iq->outlist);
3315 iq->num_current_queries = 0;
3316 fptr_ok(fptr_whitelist_modenv_detach_subs(
3317 qstate->env->detach_subs));
3318 (*qstate->env->detach_subs)(qstate);
3319 iq->num_target_queries = 0;
3320 return processDSNSFind(qstate, iq, id);
3321 }
3322 /* Process the CNAME response. */
3323 if(!handle_cname_response(qstate, iq, iq->response,
3324 &sname, &snamelen)) {
3325 errinf(qstate, "malloc failure, CNAME info");
3326 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3327 }
3328 /* cache the CNAME response under the current query */
3329 /* NOTE : set referral=1, so that rrsets get stored but not
3330 * the partial query answer (CNAME only). */
3331 /* prefetchleeway applied because this updates answer parts */
3332 if(!qstate->no_cache_store)
3333 iter_dns_store(qstate->env, &iq->response->qinfo,
3334 iq->response->rep, 1, qstate->prefetch_leeway,
3335 iq->dp&&iq->dp->has_parent_side_NS, NULL,
3336 qstate->query_flags, qstate->qstarttime);
3337 /* set the current request's qname to the new value. */
3338 iq->qchase.qname = sname;
3339 iq->qchase.qname_len = snamelen;
3340 if(qstate->env->auth_zones) {
3341 /* apply rpz qname triggers after cname */
3342 struct dns_msg* forged_response =
3343 rpz_callback_from_iterator_cname(qstate, iq);
3344 while(forged_response && reply_find_rrset_section_an(
3345 forged_response->rep, iq->qchase.qname,
3346 iq->qchase.qname_len, LDNS_RR_TYPE_CNAME,
3347 iq->qchase.qclass)) {
3348 /* another cname to follow */
3349 if(!handle_cname_response(qstate, iq, forged_response,
3350 &sname, &snamelen)) {
3351 errinf(qstate, "malloc failure, CNAME info");
3352 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3353 }
3354 iq->qchase.qname = sname;
3355 iq->qchase.qname_len = snamelen;
3356 forged_response =
3357 rpz_callback_from_iterator_cname(qstate, iq);
3358 }
3359 if(forged_response != NULL) {
3360 qstate->ext_state[id] = module_finished;
3361 qstate->return_rcode = LDNS_RCODE_NOERROR;
3362 qstate->return_msg = forged_response;
3363 iq->response = forged_response;
3364 next_state(iq, FINISHED_STATE);
3365 if(!iter_prepend(iq, qstate->return_msg, qstate->region)) {
3366 log_err("rpz: after cname, prepend rrsets: out of memory");
3367 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3368 }
3369 qstate->return_msg->qinfo = qstate->qinfo;
3370 return 0;
3371 }
3372 }
3373 /* Clear the query state, since this is a query restart. */
3374 iq->deleg_msg = NULL;
3375 iq->dp = NULL;
3376 iq->dsns_point = NULL;
3377 iq->auth_zone_response = 0;
3378 iq->sent_count = 0;
3379 iq->dp_target_count = 0;
3380 if(iq->minimisation_state != MINIMISE_STATE)
3381 /* Only count as query restart when it is not an extra
3382 * query as result of qname minimisation. */
3383 iq->query_restart_count++;
3384 if(qstate->env->cfg->qname_minimisation)
3385 iq->minimisation_state = INIT_MINIMISE_STATE;
3386
3387 /* stop current outstanding queries.
3388 * FIXME: should the outstanding queries be waited for and
3389 * handled? Say by a subquery that inherits the outbound_entry.
3390 */
3391 outbound_list_clear(&iq->outlist);
3392 iq->num_current_queries = 0;
3393 fptr_ok(fptr_whitelist_modenv_detach_subs(
3394 qstate->env->detach_subs));
3395 (*qstate->env->detach_subs)(qstate);
3396 iq->num_target_queries = 0;
3397 if(qstate->reply)
3398 sock_list_insert(&qstate->reply_origin,
3399 &qstate->reply->remote_addr,
3400 qstate->reply->remote_addrlen, qstate->region);
3401 verbose(VERB_ALGO, "cleared outbound list for query restart");
3402 /* go to INIT_REQUEST_STATE for new qname. */
3403 return next_state(iq, INIT_REQUEST_STATE);
3404 } else if(type == RESPONSE_TYPE_LAME) {
3405 /* Cache the LAMEness. */
3406 verbose(VERB_DETAIL, "query response was %sLAME",
3407 dnsseclame?"DNSSEC ":"");
3408 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
3409 log_err("mark lame: mismatch in qname and dpname");
3410 /* throwaway this reply below */
3411 } else if(qstate->reply) {
3412 /* need addr for lameness cache, but we may have
3413 * gotten this from cache, so test to be sure */
3414 if(!infra_set_lame(qstate->env->infra_cache,
3415 &qstate->reply->remote_addr,
3416 qstate->reply->remote_addrlen,
3417 iq->dp->name, iq->dp->namelen,
3418 *qstate->env->now, dnsseclame, 0,
3419 iq->qchase.qtype))
3420 log_err("mark host lame: out of memory");
3421 }
3422 } else if(type == RESPONSE_TYPE_REC_LAME) {
3423 /* Cache the LAMEness. */
3424 verbose(VERB_DETAIL, "query response REC_LAME: "
3425 "recursive but not authoritative server");
3426 if(!dname_subdomain_c(iq->qchase.qname, iq->dp->name)) {
3427 log_err("mark rec_lame: mismatch in qname and dpname");
3428 /* throwaway this reply below */
3429 } else if(qstate->reply) {
3430 /* need addr for lameness cache, but we may have
3431 * gotten this from cache, so test to be sure */
3432 verbose(VERB_DETAIL, "mark as REC_LAME");
3433 if(!infra_set_lame(qstate->env->infra_cache,
3434 &qstate->reply->remote_addr,
3435 qstate->reply->remote_addrlen,
3436 iq->dp->name, iq->dp->namelen,
3437 *qstate->env->now, 0, 1, iq->qchase.qtype))
3438 log_err("mark host lame: out of memory");
3439 }
3440 } else if(type == RESPONSE_TYPE_THROWAWAY) {
3441 /* LAME and THROWAWAY responses are handled the same way.
3442 * In this case, the event is just sent directly back to
3443 * the QUERYTARGETS_STATE without resetting anything,
3444 * because, clearly, the next target must be tried. */
3445 verbose(VERB_DETAIL, "query response was THROWAWAY");
3446 } else {
3447 log_warn("A query response came back with an unknown type: %d",
3448 (int)type);
3449 }
3450
3451 /* LAME, THROWAWAY and "unknown" all end up here.
3452 * Recycle to the QUERYTARGETS state to hopefully try a
3453 * different target. */
3454 if (qstate->env->cfg->qname_minimisation &&
3455 !qstate->env->cfg->qname_minimisation_strict)
3456 iq->minimisation_state = DONOT_MINIMISE_STATE;
3457 if(iq->auth_zone_response) {
3458 /* can we fallback? */
3459 iq->auth_zone_response = 0;
3460 if(!auth_zones_can_fallback(qstate->env->auth_zones,
3461 iq->dp->name, iq->dp->namelen, qstate->qinfo.qclass)) {
3462 verbose(VERB_ALGO, "auth zone response bad, and no"
3463 " fallback possible, servfail");
3464 errinf_dname(qstate, "response is bad, no fallback, "
3465 "for auth zone", iq->dp->name);
3466 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3467 }
3468 verbose(VERB_ALGO, "auth zone response was bad, "
3469 "fallback enabled");
3470 iq->auth_zone_avoid = 1;
3471 if(iq->dp->auth_dp) {
3472 /* we are using a dp for the auth zone, with no
3473 * nameservers, get one first */
3474 iq->dp = NULL;
3475 return next_state(iq, INIT_REQUEST_STATE);
3476 }
3477 }
3478 return next_state(iq, QUERYTARGETS_STATE);
3479 }
3480
3481 /**
3482 * Return priming query results to interested super querystates.
3483 *
3484 * Sets the delegation point and delegation message (not nonRD queries).
3485 * This is a callback from walk_supers.
3486 *
3487 * @param qstate: priming query state that finished.
3488 * @param id: module id.
3489 * @param forq: the qstate for which priming has been done.
3490 */
3491 static void
prime_supers(struct module_qstate * qstate,int id,struct module_qstate * forq)3492 prime_supers(struct module_qstate* qstate, int id, struct module_qstate* forq)
3493 {
3494 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
3495 struct delegpt* dp = NULL;
3496
3497 log_assert(qstate->is_priming || foriq->wait_priming_stub);
3498 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
3499 /* Convert our response to a delegation point */
3500 dp = delegpt_from_message(qstate->return_msg, forq->region);
3501 if(!dp) {
3502 /* if there is no convertible delegation point, then
3503 * the ANSWER type was (presumably) a negative answer. */
3504 verbose(VERB_ALGO, "prime response was not a positive "
3505 "ANSWER; failing");
3506 foriq->dp = NULL;
3507 foriq->state = QUERYTARGETS_STATE;
3508 return;
3509 }
3510
3511 log_query_info(VERB_DETAIL, "priming successful for", &qstate->qinfo);
3512 delegpt_log(VERB_ALGO, dp);
3513 foriq->dp = dp;
3514 foriq->deleg_msg = dns_copy_msg(qstate->return_msg, forq->region);
3515 if(!foriq->deleg_msg) {
3516 log_err("copy prime response: out of memory");
3517 foriq->dp = NULL;
3518 foriq->state = QUERYTARGETS_STATE;
3519 return;
3520 }
3521
3522 /* root priming responses go to init stage 2, priming stub
3523 * responses to to stage 3. */
3524 if(foriq->wait_priming_stub) {
3525 foriq->state = INIT_REQUEST_3_STATE;
3526 foriq->wait_priming_stub = 0;
3527 } else foriq->state = INIT_REQUEST_2_STATE;
3528 /* because we are finished, the parent will be reactivated */
3529 }
3530
3531 /**
3532 * This handles the response to a priming query. This is used to handle both
3533 * root and stub priming responses. This is basically the equivalent of the
3534 * QUERY_RESP_STATE, but will not handle CNAME responses and will treat
3535 * REFERRALs as ANSWERS. It will also update and reactivate the originating
3536 * event.
3537 *
3538 * @param qstate: query state.
3539 * @param id: module id.
3540 * @return true if the event needs more immediate processing, false if not.
3541 * This state always returns false.
3542 */
3543 static int
processPrimeResponse(struct module_qstate * qstate,int id)3544 processPrimeResponse(struct module_qstate* qstate, int id)
3545 {
3546 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
3547 enum response_type type;
3548 iq->response->rep->flags &= ~(BIT_RD|BIT_RA); /* ignore rec-lame */
3549 type = response_type_from_server(
3550 (int)((iq->chase_flags&BIT_RD) || iq->chase_to_rd),
3551 iq->response, &iq->qchase, iq->dp, NULL);
3552 if(type == RESPONSE_TYPE_ANSWER) {
3553 qstate->return_rcode = LDNS_RCODE_NOERROR;
3554 qstate->return_msg = iq->response;
3555 } else {
3556 errinf(qstate, "prime response did not get an answer");
3557 errinf_dname(qstate, "for", qstate->qinfo.qname);
3558 qstate->return_rcode = LDNS_RCODE_SERVFAIL;
3559 qstate->return_msg = NULL;
3560 }
3561
3562 /* validate the root or stub after priming (if enabled).
3563 * This is the same query as the prime query, but with validation.
3564 * Now that we are primed, the additional queries that validation
3565 * may need can be resolved. */
3566 if(qstate->env->cfg->harden_referral_path) {
3567 struct module_qstate* subq = NULL;
3568 log_nametypeclass(VERB_ALGO, "schedule prime validation",
3569 qstate->qinfo.qname, qstate->qinfo.qtype,
3570 qstate->qinfo.qclass);
3571 if(!generate_sub_request(qstate->qinfo.qname,
3572 qstate->qinfo.qname_len, qstate->qinfo.qtype,
3573 qstate->qinfo.qclass, qstate, id, iq,
3574 INIT_REQUEST_STATE, FINISHED_STATE, &subq, 1, 0)) {
3575 verbose(VERB_ALGO, "could not generate prime check");
3576 }
3577 generate_a_aaaa_check(qstate, iq, id);
3578 }
3579
3580 /* This event is finished. */
3581 qstate->ext_state[id] = module_finished;
3582 return 0;
3583 }
3584
3585 /**
3586 * Do final processing on responses to target queries. Events reach this
3587 * state after the iterative resolution algorithm terminates. This state is
3588 * responsible for reactivating the original event, and housekeeping related
3589 * to received target responses (caching, updating the current delegation
3590 * point, etc).
3591 * Callback from walk_supers for every super state that is interested in
3592 * the results from this query.
3593 *
3594 * @param qstate: query state.
3595 * @param id: module id.
3596 * @param forq: super query state.
3597 */
3598 static void
processTargetResponse(struct module_qstate * qstate,int id,struct module_qstate * forq)3599 processTargetResponse(struct module_qstate* qstate, int id,
3600 struct module_qstate* forq)
3601 {
3602 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
3603 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
3604 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
3605 struct ub_packed_rrset_key* rrset;
3606 struct delegpt_ns* dpns;
3607 log_assert(qstate->return_rcode == LDNS_RCODE_NOERROR);
3608
3609 foriq->state = QUERYTARGETS_STATE;
3610 log_query_info(VERB_ALGO, "processTargetResponse", &qstate->qinfo);
3611 log_query_info(VERB_ALGO, "processTargetResponse super", &forq->qinfo);
3612
3613 /* Tell the originating event that this target query has finished
3614 * (regardless if it succeeded or not). */
3615 foriq->num_target_queries--;
3616
3617 /* check to see if parent event is still interested (in orig name). */
3618 if(!foriq->dp) {
3619 verbose(VERB_ALGO, "subq: parent not interested, was reset");
3620 return; /* not interested anymore */
3621 }
3622 dpns = delegpt_find_ns(foriq->dp, qstate->qinfo.qname,
3623 qstate->qinfo.qname_len);
3624 if(!dpns) {
3625 /* If not interested, just stop processing this event */
3626 verbose(VERB_ALGO, "subq: parent not interested anymore");
3627 /* could be because parent was jostled out of the cache,
3628 and a new identical query arrived, that does not want it*/
3629 return;
3630 }
3631
3632 /* if iq->query_for_pside_glue then add the pside_glue (marked lame) */
3633 if(iq->pside_glue) {
3634 /* if the pside_glue is NULL, then it could not be found,
3635 * the done_pside is already set when created and a cache
3636 * entry created in processFinished so nothing to do here */
3637 log_rrset_key(VERB_ALGO, "add parentside glue to dp",
3638 iq->pside_glue);
3639 if(!delegpt_add_rrset(foriq->dp, forq->region,
3640 iq->pside_glue, 1, NULL))
3641 log_err("out of memory adding pside glue");
3642 }
3643
3644 /* This response is relevant to the current query, so we
3645 * add (attempt to add, anyway) this target(s) and reactivate
3646 * the original event.
3647 * NOTE: we could only look for the AnswerRRset if the
3648 * response type was ANSWER. */
3649 rrset = reply_find_answer_rrset(&iq->qchase, qstate->return_msg->rep);
3650 if(rrset) {
3651 int additions = 0;
3652 /* if CNAMEs have been followed - add new NS to delegpt. */
3653 /* BTW. RFC 1918 says NS should not have got CNAMEs. Robust. */
3654 if(!delegpt_find_ns(foriq->dp, rrset->rk.dname,
3655 rrset->rk.dname_len)) {
3656 /* if dpns->lame then set newcname ns lame too */
3657 if(!delegpt_add_ns(foriq->dp, forq->region,
3658 rrset->rk.dname, dpns->lame, dpns->tls_auth_name,
3659 dpns->port))
3660 log_err("out of memory adding cnamed-ns");
3661 }
3662 /* if dpns->lame then set the address(es) lame too */
3663 if(!delegpt_add_rrset(foriq->dp, forq->region, rrset,
3664 dpns->lame, &additions))
3665 log_err("out of memory adding targets");
3666 if(!additions) {
3667 /* no new addresses, increase the nxns counter, like
3668 * this could be a list of wildcards with no new
3669 * addresses */
3670 target_count_increase_nx(foriq, 1);
3671 }
3672 verbose(VERB_ALGO, "added target response");
3673 delegpt_log(VERB_ALGO, foriq->dp);
3674 } else {
3675 verbose(VERB_ALGO, "iterator TargetResponse failed");
3676 delegpt_mark_neg(dpns, qstate->qinfo.qtype);
3677 if((dpns->got4 == 2 || (!ie->supports_ipv4 && !ie->use_nat64)) &&
3678 (dpns->got6 == 2 || !ie->supports_ipv6)) {
3679 dpns->resolved = 1; /* fail the target */
3680 /* do not count cached answers */
3681 if(qstate->reply_origin && qstate->reply_origin->len != 0) {
3682 target_count_increase_nx(foriq, 1);
3683 }
3684 }
3685 }
3686 }
3687
3688 /**
3689 * Process response for DS NS Find queries, that attempt to find the delegation
3690 * point where we ask the DS query from.
3691 *
3692 * @param qstate: query state.
3693 * @param id: module id.
3694 * @param forq: super query state.
3695 */
3696 static void
processDSNSResponse(struct module_qstate * qstate,int id,struct module_qstate * forq)3697 processDSNSResponse(struct module_qstate* qstate, int id,
3698 struct module_qstate* forq)
3699 {
3700 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
3701
3702 /* if the finished (iq->response) query has no NS set: continue
3703 * up to look for the right dp; nothing to change, do DPNSstate */
3704 if(qstate->return_rcode != LDNS_RCODE_NOERROR)
3705 return; /* seek further */
3706 /* find the NS RRset (without allowing CNAMEs) */
3707 if(!reply_find_rrset(qstate->return_msg->rep, qstate->qinfo.qname,
3708 qstate->qinfo.qname_len, LDNS_RR_TYPE_NS,
3709 qstate->qinfo.qclass)){
3710 return; /* seek further */
3711 }
3712
3713 /* else, store as DP and continue at querytargets */
3714 foriq->state = QUERYTARGETS_STATE;
3715 foriq->dp = delegpt_from_message(qstate->return_msg, forq->region);
3716 if(!foriq->dp) {
3717 log_err("out of memory in dsns dp alloc");
3718 errinf(qstate, "malloc failure, in DS search");
3719 return; /* dp==NULL in QUERYTARGETS makes SERVFAIL */
3720 }
3721 /* success, go query the querytargets in the new dp (and go down) */
3722 }
3723
3724 /**
3725 * Process response for qclass=ANY queries for a particular class.
3726 * Append to result or error-exit.
3727 *
3728 * @param qstate: query state.
3729 * @param id: module id.
3730 * @param forq: super query state.
3731 */
3732 static void
processClassResponse(struct module_qstate * qstate,int id,struct module_qstate * forq)3733 processClassResponse(struct module_qstate* qstate, int id,
3734 struct module_qstate* forq)
3735 {
3736 struct iter_qstate* foriq = (struct iter_qstate*)forq->minfo[id];
3737 struct dns_msg* from = qstate->return_msg;
3738 log_query_info(VERB_ALGO, "processClassResponse", &qstate->qinfo);
3739 log_query_info(VERB_ALGO, "processClassResponse super", &forq->qinfo);
3740 if(qstate->return_rcode != LDNS_RCODE_NOERROR) {
3741 /* cause servfail for qclass ANY query */
3742 foriq->response = NULL;
3743 foriq->state = FINISHED_STATE;
3744 return;
3745 }
3746 /* append result */
3747 if(!foriq->response) {
3748 /* allocate the response: copy RCODE, sec_state */
3749 foriq->response = dns_copy_msg(from, forq->region);
3750 if(!foriq->response) {
3751 log_err("malloc failed for qclass ANY response");
3752 foriq->state = FINISHED_STATE;
3753 return;
3754 }
3755 foriq->response->qinfo.qclass = forq->qinfo.qclass;
3756 /* qclass ANY does not receive the AA flag on replies */
3757 foriq->response->rep->authoritative = 0;
3758 } else {
3759 struct dns_msg* to = foriq->response;
3760 /* add _from_ this response _to_ existing collection */
3761 /* if there are records, copy RCODE */
3762 /* lower sec_state if this message is lower */
3763 if(from->rep->rrset_count != 0) {
3764 size_t n = from->rep->rrset_count+to->rep->rrset_count;
3765 struct ub_packed_rrset_key** dest, **d;
3766 /* copy appropriate rcode */
3767 to->rep->flags = from->rep->flags;
3768 /* copy rrsets */
3769 if(from->rep->rrset_count > RR_COUNT_MAX ||
3770 to->rep->rrset_count > RR_COUNT_MAX) {
3771 log_err("malloc failed (too many rrsets) in collect ANY");
3772 foriq->state = FINISHED_STATE;
3773 return; /* integer overflow protection */
3774 }
3775 dest = regional_alloc(forq->region, sizeof(dest[0])*n);
3776 if(!dest) {
3777 log_err("malloc failed in collect ANY");
3778 foriq->state = FINISHED_STATE;
3779 return;
3780 }
3781 d = dest;
3782 /* copy AN */
3783 memcpy(dest, to->rep->rrsets, to->rep->an_numrrsets
3784 * sizeof(dest[0]));
3785 dest += to->rep->an_numrrsets;
3786 memcpy(dest, from->rep->rrsets, from->rep->an_numrrsets
3787 * sizeof(dest[0]));
3788 dest += from->rep->an_numrrsets;
3789 /* copy NS */
3790 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets,
3791 to->rep->ns_numrrsets * sizeof(dest[0]));
3792 dest += to->rep->ns_numrrsets;
3793 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets,
3794 from->rep->ns_numrrsets * sizeof(dest[0]));
3795 dest += from->rep->ns_numrrsets;
3796 /* copy AR */
3797 memcpy(dest, to->rep->rrsets+to->rep->an_numrrsets+
3798 to->rep->ns_numrrsets,
3799 to->rep->ar_numrrsets * sizeof(dest[0]));
3800 dest += to->rep->ar_numrrsets;
3801 memcpy(dest, from->rep->rrsets+from->rep->an_numrrsets+
3802 from->rep->ns_numrrsets,
3803 from->rep->ar_numrrsets * sizeof(dest[0]));
3804 /* update counts */
3805 to->rep->rrsets = d;
3806 to->rep->an_numrrsets += from->rep->an_numrrsets;
3807 to->rep->ns_numrrsets += from->rep->ns_numrrsets;
3808 to->rep->ar_numrrsets += from->rep->ar_numrrsets;
3809 to->rep->rrset_count = n;
3810 }
3811 if(from->rep->security < to->rep->security) /* lowest sec */
3812 to->rep->security = from->rep->security;
3813 if(from->rep->qdcount != 0) /* insert qd if appropriate */
3814 to->rep->qdcount = from->rep->qdcount;
3815 if(from->rep->ttl < to->rep->ttl) /* use smallest TTL */
3816 to->rep->ttl = from->rep->ttl;
3817 if(from->rep->prefetch_ttl < to->rep->prefetch_ttl)
3818 to->rep->prefetch_ttl = from->rep->prefetch_ttl;
3819 if(from->rep->serve_expired_ttl < to->rep->serve_expired_ttl)
3820 to->rep->serve_expired_ttl = from->rep->serve_expired_ttl;
3821 }
3822 /* are we done? */
3823 foriq->num_current_queries --;
3824 if(foriq->num_current_queries == 0)
3825 foriq->state = FINISHED_STATE;
3826 }
3827
3828 /**
3829 * Collect class ANY responses and make them into one response. This
3830 * state is started and it creates queries for all classes (that have
3831 * root hints). The answers are then collected.
3832 *
3833 * @param qstate: query state.
3834 * @param id: module id.
3835 * @return true if the event needs more immediate processing, false if not.
3836 */
3837 static int
processCollectClass(struct module_qstate * qstate,int id)3838 processCollectClass(struct module_qstate* qstate, int id)
3839 {
3840 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
3841 struct module_qstate* subq;
3842 /* If qchase.qclass == 0 then send out queries for all classes.
3843 * Otherwise, do nothing (wait for all answers to arrive and the
3844 * processClassResponse to put them together, and that moves us
3845 * towards the Finished state when done. */
3846 if(iq->qchase.qclass == 0) {
3847 uint16_t c = 0;
3848 iq->qchase.qclass = LDNS_RR_CLASS_ANY;
3849 while(iter_get_next_root(qstate->env->hints,
3850 qstate->env->fwds, &c)) {
3851 /* generate query for this class */
3852 log_nametypeclass(VERB_ALGO, "spawn collect query",
3853 qstate->qinfo.qname, qstate->qinfo.qtype, c);
3854 if(!generate_sub_request(qstate->qinfo.qname,
3855 qstate->qinfo.qname_len, qstate->qinfo.qtype,
3856 c, qstate, id, iq, INIT_REQUEST_STATE,
3857 FINISHED_STATE, &subq,
3858 (int)!(qstate->query_flags&BIT_CD), 0)) {
3859 errinf(qstate, "could not generate class ANY"
3860 " lookup query");
3861 return error_response(qstate, id,
3862 LDNS_RCODE_SERVFAIL);
3863 }
3864 /* ignore subq, no special init required */
3865 iq->num_current_queries ++;
3866 if(c == 0xffff)
3867 break;
3868 else c++;
3869 }
3870 /* if no roots are configured at all, return */
3871 if(iq->num_current_queries == 0) {
3872 verbose(VERB_ALGO, "No root hints or fwds, giving up "
3873 "on qclass ANY");
3874 return error_response(qstate, id, LDNS_RCODE_REFUSED);
3875 }
3876 /* return false, wait for queries to return */
3877 }
3878 /* if woke up here because of an answer, wait for more answers */
3879 return 0;
3880 }
3881
3882 /**
3883 * This handles the final state for first-tier responses (i.e., responses to
3884 * externally generated queries).
3885 *
3886 * @param qstate: query state.
3887 * @param iq: iterator query state.
3888 * @param id: module id.
3889 * @return true if the event needs more processing, false if not. Since this
3890 * is the final state for an event, it always returns false.
3891 */
3892 static int
processFinished(struct module_qstate * qstate,struct iter_qstate * iq,int id)3893 processFinished(struct module_qstate* qstate, struct iter_qstate* iq,
3894 int id)
3895 {
3896 log_query_info(VERB_QUERY, "finishing processing for",
3897 &qstate->qinfo);
3898
3899 /* store negative cache element for parent side glue. */
3900 if(!qstate->no_cache_store && iq->query_for_pside_glue
3901 && !iq->pside_glue)
3902 iter_store_parentside_neg(qstate->env, &qstate->qinfo,
3903 iq->deleg_msg?iq->deleg_msg->rep:
3904 (iq->response?iq->response->rep:NULL));
3905 if(!iq->response) {
3906 verbose(VERB_ALGO, "No response is set, servfail");
3907 errinf(qstate, "(no response found at query finish)");
3908 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3909 }
3910
3911 /* Make sure that the RA flag is set (since the presence of
3912 * this module means that recursion is available) */
3913 iq->response->rep->flags |= BIT_RA;
3914
3915 /* Clear the AA flag */
3916 /* FIXME: does this action go here or in some other module? */
3917 iq->response->rep->flags &= ~BIT_AA;
3918
3919 /* make sure QR flag is on */
3920 iq->response->rep->flags |= BIT_QR;
3921
3922 /* explicitly set the EDE string to NULL */
3923 iq->response->rep->reason_bogus_str = NULL;
3924 if((qstate->env->cfg->val_log_level >= 2 ||
3925 qstate->env->cfg->log_servfail) && qstate->errinf &&
3926 !qstate->env->cfg->val_log_squelch) {
3927 char* err_str = errinf_to_str_misc(qstate);
3928 if(err_str) {
3929 size_t err_str_len = strlen(err_str);
3930 verbose(VERB_ALGO, "iterator EDE: %s", err_str);
3931 /* allocate space and store the error
3932 * string */
3933 iq->response->rep->reason_bogus_str = regional_alloc(
3934 qstate->region,
3935 sizeof(char) * (err_str_len+1));
3936 memcpy(iq->response->rep->reason_bogus_str,
3937 err_str, err_str_len+1);
3938 }
3939 free(err_str);
3940 }
3941
3942 /* we have finished processing this query */
3943 qstate->ext_state[id] = module_finished;
3944
3945 /* TODO: we are using a private TTL, trim the response. */
3946 /* if (mPrivateTTL > 0){IterUtils.setPrivateTTL(resp, mPrivateTTL); } */
3947
3948 /* prepend any items we have accumulated */
3949 if(iq->an_prepend_list || iq->ns_prepend_list) {
3950 if(!iter_prepend(iq, iq->response, qstate->region)) {
3951 log_err("prepend rrsets: out of memory");
3952 return error_response(qstate, id, LDNS_RCODE_SERVFAIL);
3953 }
3954 /* reset the query name back */
3955 iq->response->qinfo = qstate->qinfo;
3956 /* the security state depends on the combination */
3957 iq->response->rep->security = sec_status_unchecked;
3958 /* store message with the finished prepended items,
3959 * but only if we did recursion. The nonrecursion referral
3960 * from cache does not need to be stored in the msg cache. */
3961 if(!qstate->no_cache_store && qstate->query_flags&BIT_RD) {
3962 iter_dns_store(qstate->env, &qstate->qinfo,
3963 iq->response->rep, 0, qstate->prefetch_leeway,
3964 iq->dp&&iq->dp->has_parent_side_NS,
3965 qstate->region, qstate->query_flags,
3966 qstate->qstarttime);
3967 }
3968 }
3969 qstate->return_rcode = LDNS_RCODE_NOERROR;
3970 qstate->return_msg = iq->response;
3971 return 0;
3972 }
3973
3974 /*
3975 * Return priming query results to interested super querystates.
3976 *
3977 * Sets the delegation point and delegation message (not nonRD queries).
3978 * This is a callback from walk_supers.
3979 *
3980 * @param qstate: query state that finished.
3981 * @param id: module id.
3982 * @param super: the qstate to inform.
3983 */
3984 void
iter_inform_super(struct module_qstate * qstate,int id,struct module_qstate * super)3985 iter_inform_super(struct module_qstate* qstate, int id,
3986 struct module_qstate* super)
3987 {
3988 if(!qstate->is_priming && super->qinfo.qclass == LDNS_RR_CLASS_ANY)
3989 processClassResponse(qstate, id, super);
3990 else if(super->qinfo.qtype == LDNS_RR_TYPE_DS && ((struct iter_qstate*)
3991 super->minfo[id])->state == DSNS_FIND_STATE)
3992 processDSNSResponse(qstate, id, super);
3993 else if(qstate->return_rcode != LDNS_RCODE_NOERROR)
3994 error_supers(qstate, id, super);
3995 else if(qstate->is_priming)
3996 prime_supers(qstate, id, super);
3997 else processTargetResponse(qstate, id, super);
3998 }
3999
4000 /**
4001 * Handle iterator state.
4002 * Handle events. This is the real processing loop for events, responsible
4003 * for moving events through the various states. If a processing method
4004 * returns true, then it will be advanced to the next state. If false, then
4005 * processing will stop.
4006 *
4007 * @param qstate: query state.
4008 * @param ie: iterator shared global environment.
4009 * @param iq: iterator query state.
4010 * @param id: module id.
4011 */
4012 static void
iter_handle(struct module_qstate * qstate,struct iter_qstate * iq,struct iter_env * ie,int id)4013 iter_handle(struct module_qstate* qstate, struct iter_qstate* iq,
4014 struct iter_env* ie, int id)
4015 {
4016 int cont = 1;
4017 while(cont) {
4018 verbose(VERB_ALGO, "iter_handle processing q with state %s",
4019 iter_state_to_string(iq->state));
4020 switch(iq->state) {
4021 case INIT_REQUEST_STATE:
4022 cont = processInitRequest(qstate, iq, ie, id);
4023 break;
4024 case INIT_REQUEST_2_STATE:
4025 cont = processInitRequest2(qstate, iq, id);
4026 break;
4027 case INIT_REQUEST_3_STATE:
4028 cont = processInitRequest3(qstate, iq, id);
4029 break;
4030 case QUERYTARGETS_STATE:
4031 cont = processQueryTargets(qstate, iq, ie, id);
4032 break;
4033 case QUERY_RESP_STATE:
4034 cont = processQueryResponse(qstate, iq, ie, id);
4035 break;
4036 case PRIME_RESP_STATE:
4037 cont = processPrimeResponse(qstate, id);
4038 break;
4039 case COLLECT_CLASS_STATE:
4040 cont = processCollectClass(qstate, id);
4041 break;
4042 case DSNS_FIND_STATE:
4043 cont = processDSNSFind(qstate, iq, id);
4044 break;
4045 case FINISHED_STATE:
4046 cont = processFinished(qstate, iq, id);
4047 break;
4048 default:
4049 log_warn("iterator: invalid state: %d",
4050 iq->state);
4051 cont = 0;
4052 break;
4053 }
4054 }
4055 }
4056
4057 /**
4058 * This is the primary entry point for processing request events. Note that
4059 * this method should only be used by external modules.
4060 * @param qstate: query state.
4061 * @param ie: iterator shared global environment.
4062 * @param iq: iterator query state.
4063 * @param id: module id.
4064 */
4065 static void
process_request(struct module_qstate * qstate,struct iter_qstate * iq,struct iter_env * ie,int id)4066 process_request(struct module_qstate* qstate, struct iter_qstate* iq,
4067 struct iter_env* ie, int id)
4068 {
4069 /* external requests start in the INIT state, and finish using the
4070 * FINISHED state. */
4071 iq->state = INIT_REQUEST_STATE;
4072 iq->final_state = FINISHED_STATE;
4073 verbose(VERB_ALGO, "process_request: new external request event");
4074 iter_handle(qstate, iq, ie, id);
4075 }
4076
4077 /** process authoritative server reply */
4078 static void
process_response(struct module_qstate * qstate,struct iter_qstate * iq,struct iter_env * ie,int id,struct outbound_entry * outbound,enum module_ev event)4079 process_response(struct module_qstate* qstate, struct iter_qstate* iq,
4080 struct iter_env* ie, int id, struct outbound_entry* outbound,
4081 enum module_ev event)
4082 {
4083 struct msg_parse* prs;
4084 struct edns_data edns;
4085 sldns_buffer* pkt;
4086
4087 verbose(VERB_ALGO, "process_response: new external response event");
4088 iq->response = NULL;
4089 iq->state = QUERY_RESP_STATE;
4090 if(event == module_event_noreply || event == module_event_error) {
4091 if(event == module_event_noreply && iq->timeout_count >= 3 &&
4092 qstate->env->cfg->use_caps_bits_for_id &&
4093 !iq->caps_fallback && !is_caps_whitelisted(ie, iq)) {
4094 /* start fallback */
4095 iq->caps_fallback = 1;
4096 iq->caps_server = 0;
4097 iq->caps_reply = NULL;
4098 iq->caps_response = NULL;
4099 iq->caps_minimisation_state = DONOT_MINIMISE_STATE;
4100 iq->state = QUERYTARGETS_STATE;
4101 iq->num_current_queries--;
4102 /* need fresh attempts for the 0x20 fallback, if
4103 * that was the cause for the failure */
4104 iter_dec_attempts(iq->dp, 3, ie->outbound_msg_retry);
4105 verbose(VERB_DETAIL, "Capsforid: timeouts, starting fallback");
4106 goto handle_it;
4107 }
4108 goto handle_it;
4109 }
4110 if( (event != module_event_reply && event != module_event_capsfail)
4111 || !qstate->reply) {
4112 log_err("Bad event combined with response");
4113 outbound_list_remove(&iq->outlist, outbound);
4114 errinf(qstate, "module iterator received wrong internal event with a response message");
4115 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
4116 return;
4117 }
4118
4119 /* parse message */
4120 fill_fail_addr(iq, &qstate->reply->remote_addr,
4121 qstate->reply->remote_addrlen);
4122 prs = (struct msg_parse*)regional_alloc(qstate->env->scratch,
4123 sizeof(struct msg_parse));
4124 if(!prs) {
4125 log_err("out of memory on incoming message");
4126 /* like packet got dropped */
4127 goto handle_it;
4128 }
4129 memset(prs, 0, sizeof(*prs));
4130 memset(&edns, 0, sizeof(edns));
4131 pkt = qstate->reply->c->buffer;
4132 sldns_buffer_set_position(pkt, 0);
4133 if(parse_packet(pkt, prs, qstate->env->scratch) != LDNS_RCODE_NOERROR) {
4134 verbose(VERB_ALGO, "parse error on reply packet");
4135 iq->parse_failures++;
4136 goto handle_it;
4137 }
4138 /* edns is not examined, but removed from message to help cache */
4139 if(parse_extract_edns_from_response_msg(prs, &edns, qstate->env->scratch) !=
4140 LDNS_RCODE_NOERROR) {
4141 iq->parse_failures++;
4142 goto handle_it;
4143 }
4144
4145 /* Copy the edns options we may got from the back end */
4146 if(edns.opt_list_in) {
4147 qstate->edns_opts_back_in = edns_opt_copy_region(edns.opt_list_in,
4148 qstate->region);
4149 if(!qstate->edns_opts_back_in) {
4150 log_err("out of memory on incoming message");
4151 /* like packet got dropped */
4152 goto handle_it;
4153 }
4154 }
4155 if(!inplace_cb_edns_back_parsed_call(qstate->env, qstate)) {
4156 log_err("unable to call edns_back_parsed callback");
4157 goto handle_it;
4158 }
4159
4160 /* remove CD-bit, we asked for in case we handle validation ourself */
4161 prs->flags &= ~BIT_CD;
4162
4163 /* normalize and sanitize: easy to delete items from linked lists */
4164 if(!scrub_message(pkt, prs, &iq->qinfo_out, iq->dp->name,
4165 qstate->env->scratch, qstate->env, qstate, ie)) {
4166 /* if 0x20 enabled, start fallback, but we have no message */
4167 if(event == module_event_capsfail && !iq->caps_fallback) {
4168 iq->caps_fallback = 1;
4169 iq->caps_server = 0;
4170 iq->caps_reply = NULL;
4171 iq->caps_response = NULL;
4172 iq->caps_minimisation_state = DONOT_MINIMISE_STATE;
4173 iq->state = QUERYTARGETS_STATE;
4174 iq->num_current_queries--;
4175 verbose(VERB_DETAIL, "Capsforid: scrub failed, starting fallback with no response");
4176 }
4177 iq->scrub_failures++;
4178 goto handle_it;
4179 }
4180
4181 /* allocate response dns_msg in region */
4182 iq->response = dns_alloc_msg(pkt, prs, qstate->region);
4183 if(!iq->response)
4184 goto handle_it;
4185 log_query_info(VERB_DETAIL, "response for", &qstate->qinfo);
4186 log_name_addr(VERB_DETAIL, "reply from", iq->dp->name,
4187 &qstate->reply->remote_addr, qstate->reply->remote_addrlen);
4188 if(verbosity >= VERB_ALGO)
4189 log_dns_msg("incoming scrubbed packet:", &iq->response->qinfo,
4190 iq->response->rep);
4191
4192 if(event == module_event_capsfail || iq->caps_fallback) {
4193 if(qstate->env->cfg->qname_minimisation &&
4194 iq->minimisation_state != DONOT_MINIMISE_STATE) {
4195 /* Skip QNAME minimisation for next query, since that
4196 * one has to match the current query. */
4197 iq->minimisation_state = SKIP_MINIMISE_STATE;
4198 }
4199 /* for fallback we care about main answer, not additionals */
4200 /* removing that makes comparison more likely to succeed */
4201 caps_strip_reply(iq->response->rep);
4202
4203 if(iq->caps_fallback &&
4204 iq->caps_minimisation_state != iq->minimisation_state) {
4205 /* QNAME minimisation state has changed, restart caps
4206 * fallback. */
4207 iq->caps_fallback = 0;
4208 }
4209
4210 if(!iq->caps_fallback) {
4211 /* start fallback */
4212 iq->caps_fallback = 1;
4213 iq->caps_server = 0;
4214 iq->caps_reply = iq->response->rep;
4215 iq->caps_response = iq->response;
4216 iq->caps_minimisation_state = iq->minimisation_state;
4217 iq->state = QUERYTARGETS_STATE;
4218 iq->num_current_queries--;
4219 verbose(VERB_DETAIL, "Capsforid: starting fallback");
4220 goto handle_it;
4221 } else {
4222 /* check if reply is the same, otherwise, fail */
4223 if(!iq->caps_reply) {
4224 iq->caps_reply = iq->response->rep;
4225 iq->caps_response = iq->response;
4226 iq->caps_server = -1; /*become zero at ++,
4227 so that we start the full set of trials */
4228 } else if(caps_failed_rcode(iq->caps_reply) &&
4229 !caps_failed_rcode(iq->response->rep)) {
4230 /* prefer to upgrade to non-SERVFAIL */
4231 iq->caps_reply = iq->response->rep;
4232 iq->caps_response = iq->response;
4233 } else if(!caps_failed_rcode(iq->caps_reply) &&
4234 caps_failed_rcode(iq->response->rep)) {
4235 /* if we have non-SERVFAIL as answer then
4236 * we can ignore SERVFAILs for the equality
4237 * comparison */
4238 /* no instructions here, skip other else */
4239 } else if(caps_failed_rcode(iq->caps_reply) &&
4240 caps_failed_rcode(iq->response->rep)) {
4241 /* failure is same as other failure in fallbk*/
4242 /* no instructions here, skip other else */
4243 } else if(!reply_equal(iq->response->rep, iq->caps_reply,
4244 qstate->env->scratch)) {
4245 verbose(VERB_DETAIL, "Capsforid fallback: "
4246 "getting different replies, failed");
4247 outbound_list_remove(&iq->outlist, outbound);
4248 errinf(qstate, "0x20 failed, then got different replies in fallback");
4249 (void)error_response(qstate, id,
4250 LDNS_RCODE_SERVFAIL);
4251 return;
4252 }
4253 /* continue the fallback procedure at next server */
4254 iq->caps_server++;
4255 iq->state = QUERYTARGETS_STATE;
4256 iq->num_current_queries--;
4257 verbose(VERB_DETAIL, "Capsforid: reply is equal. "
4258 "go to next fallback");
4259 goto handle_it;
4260 }
4261 }
4262 iq->caps_fallback = 0; /* if we were in fallback, 0x20 is OK now */
4263
4264 handle_it:
4265 outbound_list_remove(&iq->outlist, outbound);
4266 iter_handle(qstate, iq, ie, id);
4267 }
4268
4269 void
iter_operate(struct module_qstate * qstate,enum module_ev event,int id,struct outbound_entry * outbound)4270 iter_operate(struct module_qstate* qstate, enum module_ev event, int id,
4271 struct outbound_entry* outbound)
4272 {
4273 struct iter_env* ie = (struct iter_env*)qstate->env->modinfo[id];
4274 struct iter_qstate* iq = (struct iter_qstate*)qstate->minfo[id];
4275 verbose(VERB_QUERY, "iterator[module %d] operate: extstate:%s event:%s",
4276 id, strextstate(qstate->ext_state[id]), strmodulevent(event));
4277 if(iq) log_query_info(VERB_QUERY, "iterator operate: query",
4278 &qstate->qinfo);
4279 if(iq && qstate->qinfo.qname != iq->qchase.qname)
4280 log_query_info(VERB_QUERY, "iterator operate: chased to",
4281 &iq->qchase);
4282
4283 /* perform iterator state machine */
4284 if((event == module_event_new || event == module_event_pass) &&
4285 iq == NULL) {
4286 if(!iter_new(qstate, id)) {
4287 errinf(qstate, "malloc failure, new iterator module allocation");
4288 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
4289 return;
4290 }
4291 iq = (struct iter_qstate*)qstate->minfo[id];
4292 process_request(qstate, iq, ie, id);
4293 return;
4294 }
4295 if(iq && event == module_event_pass) {
4296 iter_handle(qstate, iq, ie, id);
4297 return;
4298 }
4299 if(iq && outbound) {
4300 process_response(qstate, iq, ie, id, outbound, event);
4301 return;
4302 }
4303 if(event == module_event_error) {
4304 verbose(VERB_ALGO, "got called with event error, giving up");
4305 errinf(qstate, "iterator module got the error event");
4306 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
4307 return;
4308 }
4309
4310 log_err("bad event for iterator");
4311 errinf(qstate, "iterator module received wrong event");
4312 (void)error_response(qstate, id, LDNS_RCODE_SERVFAIL);
4313 }
4314
4315 void
iter_clear(struct module_qstate * qstate,int id)4316 iter_clear(struct module_qstate* qstate, int id)
4317 {
4318 struct iter_qstate* iq;
4319 if(!qstate)
4320 return;
4321 iq = (struct iter_qstate*)qstate->minfo[id];
4322 if(iq) {
4323 outbound_list_clear(&iq->outlist);
4324 if(iq->target_count && --iq->target_count[TARGET_COUNT_REF] == 0) {
4325 free(iq->target_count);
4326 if(*iq->nxns_dp) free(*iq->nxns_dp);
4327 free(iq->nxns_dp);
4328 }
4329 iq->num_current_queries = 0;
4330 }
4331 qstate->minfo[id] = NULL;
4332 }
4333
4334 size_t
iter_get_mem(struct module_env * env,int id)4335 iter_get_mem(struct module_env* env, int id)
4336 {
4337 struct iter_env* ie = (struct iter_env*)env->modinfo[id];
4338 if(!ie)
4339 return 0;
4340 return sizeof(*ie) + sizeof(int)*((size_t)ie->max_dependency_depth+1)
4341 + donotq_get_mem(ie->donotq) + priv_get_mem(ie->priv);
4342 }
4343
4344 /**
4345 * The iterator function block
4346 */
4347 static struct module_func_block iter_block = {
4348 "iterator",
4349 &iter_init, &iter_deinit, &iter_operate, &iter_inform_super,
4350 &iter_clear, &iter_get_mem
4351 };
4352
4353 struct module_func_block*
iter_get_funcblock(void)4354 iter_get_funcblock(void)
4355 {
4356 return &iter_block;
4357 }
4358
4359 const char*
iter_state_to_string(enum iter_state state)4360 iter_state_to_string(enum iter_state state)
4361 {
4362 switch (state)
4363 {
4364 case INIT_REQUEST_STATE :
4365 return "INIT REQUEST STATE";
4366 case INIT_REQUEST_2_STATE :
4367 return "INIT REQUEST STATE (stage 2)";
4368 case INIT_REQUEST_3_STATE:
4369 return "INIT REQUEST STATE (stage 3)";
4370 case QUERYTARGETS_STATE :
4371 return "QUERY TARGETS STATE";
4372 case PRIME_RESP_STATE :
4373 return "PRIME RESPONSE STATE";
4374 case COLLECT_CLASS_STATE :
4375 return "COLLECT CLASS STATE";
4376 case DSNS_FIND_STATE :
4377 return "DSNS FIND STATE";
4378 case QUERY_RESP_STATE :
4379 return "QUERY RESPONSE STATE";
4380 case FINISHED_STATE :
4381 return "FINISHED RESPONSE STATE";
4382 default :
4383 return "UNKNOWN ITER STATE";
4384 }
4385 }
4386
4387 int
iter_state_is_responsestate(enum iter_state s)4388 iter_state_is_responsestate(enum iter_state s)
4389 {
4390 switch(s) {
4391 case INIT_REQUEST_STATE :
4392 case INIT_REQUEST_2_STATE :
4393 case INIT_REQUEST_3_STATE :
4394 case QUERYTARGETS_STATE :
4395 case COLLECT_CLASS_STATE :
4396 return 0;
4397 default:
4398 break;
4399 }
4400 return 1;
4401 }
4402