xref: /freebsd/contrib/unbound/daemon/worker.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
1 /*
2  * daemon/worker.c - worker that handles a pending list of requests.
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 implements the worker that handles callbacks on events, for
40  * pending requests.
41  */
42 #include "config.h"
43 #include "util/log.h"
44 #include "util/net_help.h"
45 #include "util/random.h"
46 #include "daemon/worker.h"
47 #include "daemon/daemon.h"
48 #include "daemon/remote.h"
49 #include "daemon/acl_list.h"
50 #include "util/netevent.h"
51 #include "util/config_file.h"
52 #include "util/module.h"
53 #include "util/regional.h"
54 #include "util/storage/slabhash.h"
55 #include "services/listen_dnsport.h"
56 #include "services/outside_network.h"
57 #include "services/outbound_list.h"
58 #include "services/cache/rrset.h"
59 #include "services/cache/infra.h"
60 #include "services/cache/dns.h"
61 #include "services/authzone.h"
62 #include "services/mesh.h"
63 #include "services/localzone.h"
64 #include "services/rpz.h"
65 #include "util/data/msgparse.h"
66 #include "util/data/msgencode.h"
67 #include "util/data/dname.h"
68 #include "util/fptr_wlist.h"
69 #include "util/proxy_protocol.h"
70 #include "util/tube.h"
71 #include "util/edns.h"
72 #include "util/timeval_func.h"
73 #include "iterator/iter_fwd.h"
74 #include "iterator/iter_hints.h"
75 #include "iterator/iter_utils.h"
76 #include "validator/autotrust.h"
77 #include "validator/val_anchor.h"
78 #include "respip/respip.h"
79 #include "libunbound/context.h"
80 #include "libunbound/libworker.h"
81 #include "sldns/sbuffer.h"
82 #include "sldns/wire2str.h"
83 #include "util/shm_side/shm_main.h"
84 #include "dnscrypt/dnscrypt.h"
85 #include "dnstap/dtstream.h"
86 
87 #ifdef HAVE_SYS_TYPES_H
88 #  include <sys/types.h>
89 #endif
90 #ifdef HAVE_NETDB_H
91 #include <netdb.h>
92 #endif
93 #include <signal.h>
94 #ifdef UB_ON_WINDOWS
95 #include "winrc/win_svc.h"
96 #endif
97 
98 /** Size of an UDP datagram */
99 #define NORMAL_UDP_SIZE	512 /* bytes */
100 /** ratelimit for error responses */
101 #define ERROR_RATELIMIT 100 /* qps */
102 
103 /**
104  * seconds to add to prefetch leeway.  This is a TTL that expires old rrsets
105  * earlier than they should in order to put the new update into the cache.
106  * This additional value is to make sure that if not all TTLs are equal in
107  * the message to be updated(and replaced), that rrsets with up to this much
108  * extra TTL are also replaced.  This means that the resulting new message
109  * will have (most likely) this TTL at least, avoiding very small 'split
110  * second' TTLs due to operators choosing relative primes for TTLs (or so).
111  * Also has to be at least one to break ties (and overwrite cached entry).
112  */
113 #define PREFETCH_EXPIRY_ADD 60
114 
115 /** Report on memory usage by this thread and global */
116 static void
117 worker_mem_report(struct worker* ATTR_UNUSED(worker),
118 	struct serviced_query* ATTR_UNUSED(cur_serv))
119 {
120 #ifdef UNBOUND_ALLOC_STATS
121 	/* measure memory leakage */
122 	extern size_t unbound_mem_alloc, unbound_mem_freed;
123 	/* debug func in validator module */
124 	size_t total, front, back, mesh, msg, rrset, infra, ac, superac;
125 	size_t me, iter, val, anch;
126 	int i;
127 #ifdef CLIENT_SUBNET
128 	size_t subnet = 0;
129 #endif /* CLIENT_SUBNET */
130 	if(verbosity < VERB_ALGO)
131 		return;
132 	front = listen_get_mem(worker->front);
133 	back = outnet_get_mem(worker->back);
134 	msg = slabhash_get_mem(worker->env.msg_cache);
135 	rrset = slabhash_get_mem(&worker->env.rrset_cache->table);
136 	infra = infra_get_mem(worker->env.infra_cache);
137 	mesh = mesh_get_mem(worker->env.mesh);
138 	ac = alloc_get_mem(worker->alloc);
139 	superac = alloc_get_mem(&worker->daemon->superalloc);
140 	anch = anchors_get_mem(worker->env.anchors);
141 	iter = 0;
142 	val = 0;
143 	for(i=0; i<worker->env.mesh->mods.num; i++) {
144 		fptr_ok(fptr_whitelist_mod_get_mem(worker->env.mesh->
145 			mods.mod[i]->get_mem));
146 		if(strcmp(worker->env.mesh->mods.mod[i]->name, "validator")==0)
147 			val += (*worker->env.mesh->mods.mod[i]->get_mem)
148 				(&worker->env, i);
149 #ifdef CLIENT_SUBNET
150 		else if(strcmp(worker->env.mesh->mods.mod[i]->name,
151 			"subnetcache")==0)
152 			subnet += (*worker->env.mesh->mods.mod[i]->get_mem)
153 				(&worker->env, i);
154 #endif /* CLIENT_SUBNET */
155 		else	iter += (*worker->env.mesh->mods.mod[i]->get_mem)
156 				(&worker->env, i);
157 	}
158 	me = sizeof(*worker) + sizeof(*worker->base) + sizeof(*worker->comsig)
159 		+ comm_point_get_mem(worker->cmd_com)
160 		+ sizeof(worker->rndstate)
161 		+ regional_get_mem(worker->scratchpad)
162 		+ sizeof(*worker->env.scratch_buffer)
163 		+ sldns_buffer_capacity(worker->env.scratch_buffer);
164 	if(worker->daemon->env->fwds)
165 		log_info("forwards=%u", (unsigned)forwards_get_mem(worker->env.fwds));
166 	if(worker->daemon->env->hints)
167 		log_info("hints=%u", (unsigned)hints_get_mem(worker->env.hints));
168 	if(worker->thread_num == 0)
169 		me += acl_list_get_mem(worker->daemon->acl);
170 	if(cur_serv) {
171 		me += serviced_get_mem(cur_serv);
172 	}
173 	total = front+back+mesh+msg+rrset+infra+iter+val+ac+superac+me;
174 #ifdef CLIENT_SUBNET
175 	total += subnet;
176 	log_info("Memory conditions: %u front=%u back=%u mesh=%u msg=%u "
177 		"rrset=%u infra=%u iter=%u val=%u subnet=%u anchors=%u "
178 		"alloccache=%u globalalloccache=%u me=%u",
179 		(unsigned)total, (unsigned)front, (unsigned)back,
180 		(unsigned)mesh, (unsigned)msg, (unsigned)rrset, (unsigned)infra,
181 		(unsigned)iter, (unsigned)val,
182 		(unsigned)subnet, (unsigned)anch, (unsigned)ac,
183 		(unsigned)superac, (unsigned)me);
184 #else /* no CLIENT_SUBNET */
185 	log_info("Memory conditions: %u front=%u back=%u mesh=%u msg=%u "
186 		"rrset=%u infra=%u iter=%u val=%u anchors=%u "
187 		"alloccache=%u globalalloccache=%u me=%u",
188 		(unsigned)total, (unsigned)front, (unsigned)back,
189 		(unsigned)mesh, (unsigned)msg, (unsigned)rrset,
190 		(unsigned)infra, (unsigned)iter, (unsigned)val, (unsigned)anch,
191 		(unsigned)ac, (unsigned)superac, (unsigned)me);
192 #endif /* CLIENT_SUBNET */
193 	log_info("Total heap memory estimate: %u  total-alloc: %u  "
194 		"total-free: %u", (unsigned)total,
195 		(unsigned)unbound_mem_alloc, (unsigned)unbound_mem_freed);
196 #else /* no UNBOUND_ALLOC_STATS */
197 	size_t val = 0;
198 #ifdef CLIENT_SUBNET
199 	size_t subnet = 0;
200 #endif /* CLIENT_SUBNET */
201 	int i;
202 	if(verbosity < VERB_QUERY)
203 		return;
204 	for(i=0; i<worker->env.mesh->mods.num; i++) {
205 		fptr_ok(fptr_whitelist_mod_get_mem(worker->env.mesh->
206 			mods.mod[i]->get_mem));
207 		if(strcmp(worker->env.mesh->mods.mod[i]->name, "validator")==0)
208 			val += (*worker->env.mesh->mods.mod[i]->get_mem)
209 				(&worker->env, i);
210 #ifdef CLIENT_SUBNET
211 		else if(strcmp(worker->env.mesh->mods.mod[i]->name,
212 			"subnetcache")==0)
213 			subnet += (*worker->env.mesh->mods.mod[i]->get_mem)
214 				(&worker->env, i);
215 #endif /* CLIENT_SUBNET */
216 	}
217 #ifdef CLIENT_SUBNET
218 	verbose(VERB_QUERY, "cache memory msg=%u rrset=%u infra=%u val=%u "
219 		"subnet=%u",
220 		(unsigned)slabhash_get_mem(worker->env.msg_cache),
221 		(unsigned)slabhash_get_mem(&worker->env.rrset_cache->table),
222 		(unsigned)infra_get_mem(worker->env.infra_cache),
223 		(unsigned)val, (unsigned)subnet);
224 #else /* no CLIENT_SUBNET */
225 	verbose(VERB_QUERY, "cache memory msg=%u rrset=%u infra=%u val=%u",
226 		(unsigned)slabhash_get_mem(worker->env.msg_cache),
227 		(unsigned)slabhash_get_mem(&worker->env.rrset_cache->table),
228 		(unsigned)infra_get_mem(worker->env.infra_cache),
229 		(unsigned)val);
230 #endif /* CLIENT_SUBNET */
231 #endif /* UNBOUND_ALLOC_STATS */
232 }
233 
234 void
235 worker_send_cmd(struct worker* worker, enum worker_commands cmd)
236 {
237 	uint32_t c = (uint32_t)htonl(cmd);
238 	if(!tube_write_msg(worker->cmd, (uint8_t*)&c, sizeof(c), 0)) {
239 		log_err("worker send cmd %d failed", (int)cmd);
240 	}
241 }
242 
243 int
244 worker_handle_service_reply(struct comm_point* c, void* arg, int error,
245 	struct comm_reply* reply_info)
246 {
247 	struct outbound_entry* e = (struct outbound_entry*)arg;
248 	struct worker* worker = e->qstate->env->worker;
249 	struct serviced_query *sq = e->qsent;
250 
251 	verbose(VERB_ALGO, "worker svcd callback for qstate %p", e->qstate);
252 	if(error != 0) {
253 		mesh_report_reply(worker->env.mesh, e, reply_info, error);
254 		worker_mem_report(worker, sq);
255 		return 0;
256 	}
257 	/* sanity check. */
258 	if(!LDNS_QR_WIRE(sldns_buffer_begin(c->buffer))
259 		|| LDNS_OPCODE_WIRE(sldns_buffer_begin(c->buffer)) !=
260 			LDNS_PACKET_QUERY
261 		|| LDNS_QDCOUNT(sldns_buffer_begin(c->buffer)) > 1) {
262 		/* error becomes timeout for the module as if this reply
263 		 * never arrived. */
264 		verbose(VERB_ALGO, "worker: bad reply handled as timeout");
265 		mesh_report_reply(worker->env.mesh, e, reply_info,
266 			NETEVENT_TIMEOUT);
267 		worker_mem_report(worker, sq);
268 		return 0;
269 	}
270 	mesh_report_reply(worker->env.mesh, e, reply_info, NETEVENT_NOERROR);
271 	worker_mem_report(worker, sq);
272 	return 0;
273 }
274 
275 /** ratelimit error replies
276  * @param worker: the worker struct with ratelimit counter
277  * @param err: error code that would be wanted.
278  * @return value of err if okay, or -1 if it should be discarded instead.
279  */
280 static int
281 worker_err_ratelimit(struct worker* worker, int err)
282 {
283 	if(worker->err_limit_time == *worker->env.now) {
284 		/* see if limit is exceeded for this second */
285 		if(worker->err_limit_count++ > ERROR_RATELIMIT)
286 			return -1;
287 	} else {
288 		/* new second, new limits */
289 		worker->err_limit_time = *worker->env.now;
290 		worker->err_limit_count = 1;
291 	}
292 	return err;
293 }
294 
295 /**
296  * Structure holding the result of the worker_check_request function.
297  * Based on configuration it could be called up to four times; ideally should
298  * be called once.
299  */
300 struct check_request_result {
301 	int checked;
302 	int value;
303 };
304 /** check request sanity.
305  * @param pkt: the wire packet to examine for sanity.
306  * @param worker: parameters for checking.
307  * @param out: struct to update with the result.
308 */
309 static void
310 worker_check_request(sldns_buffer* pkt, struct worker* worker,
311 	struct check_request_result* out)
312 {
313 	if(out->checked) return;
314 	out->checked = 1;
315 	if(sldns_buffer_limit(pkt) < LDNS_HEADER_SIZE) {
316 		verbose(VERB_QUERY, "request too short, discarded");
317 		out->value = -1;
318 		return;
319 	}
320 	if(sldns_buffer_limit(pkt) > NORMAL_UDP_SIZE &&
321 		worker->daemon->cfg->harden_large_queries) {
322 		verbose(VERB_QUERY, "request too large, discarded");
323 		out->value = -1;
324 		return;
325 	}
326 	if(LDNS_QR_WIRE(sldns_buffer_begin(pkt))) {
327 		verbose(VERB_QUERY, "request has QR bit on, discarded");
328 		out->value = -1;
329 		return;
330 	}
331 	if(LDNS_TC_WIRE(sldns_buffer_begin(pkt))) {
332 		LDNS_TC_CLR(sldns_buffer_begin(pkt));
333 		verbose(VERB_QUERY, "request bad, has TC bit on");
334 		out->value = worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
335 		return;
336 	}
337 	if(LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_PACKET_QUERY &&
338 		LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_PACKET_NOTIFY) {
339 		verbose(VERB_QUERY, "request unknown opcode %d",
340 			LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)));
341 		out->value = worker_err_ratelimit(worker, LDNS_RCODE_NOTIMPL);
342 		return;
343 	}
344 	if(LDNS_QDCOUNT(sldns_buffer_begin(pkt)) != 1) {
345 		verbose(VERB_QUERY, "request wrong nr qd=%d",
346 			LDNS_QDCOUNT(sldns_buffer_begin(pkt)));
347 		out->value = worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
348 		return;
349 	}
350 	if(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) != 0 &&
351 		(LDNS_ANCOUNT(sldns_buffer_begin(pkt)) != 1 ||
352 		LDNS_OPCODE_WIRE(sldns_buffer_begin(pkt)) != LDNS_PACKET_NOTIFY)) {
353 		verbose(VERB_QUERY, "request wrong nr an=%d",
354 			LDNS_ANCOUNT(sldns_buffer_begin(pkt)));
355 		out->value = worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
356 		return;
357 	}
358 	if(LDNS_NSCOUNT(sldns_buffer_begin(pkt)) != 0) {
359 		verbose(VERB_QUERY, "request wrong nr ns=%d",
360 			LDNS_NSCOUNT(sldns_buffer_begin(pkt)));
361 		out->value = worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
362 		return;
363 	}
364 	if(LDNS_ARCOUNT(sldns_buffer_begin(pkt)) > 1) {
365 		verbose(VERB_QUERY, "request wrong nr ar=%d",
366 			LDNS_ARCOUNT(sldns_buffer_begin(pkt)));
367 		out->value = worker_err_ratelimit(worker, LDNS_RCODE_FORMERR);
368 		return;
369 	}
370 	out->value = 0;
371 	return;
372 }
373 
374 void
375 worker_handle_control_cmd(struct tube* ATTR_UNUSED(tube), uint8_t* msg,
376 	size_t len, int error, void* arg)
377 {
378 	struct worker* worker = (struct worker*)arg;
379 	enum worker_commands cmd;
380 	if(error != NETEVENT_NOERROR) {
381 		free(msg);
382 		if(error == NETEVENT_CLOSED)
383 			comm_base_exit(worker->base);
384 		else	log_info("control event: %d", error);
385 		return;
386 	}
387 	if(len != sizeof(uint32_t)) {
388 		fatal_exit("bad control msg length %d", (int)len);
389 	}
390 	cmd = sldns_read_uint32(msg);
391 	free(msg);
392 	switch(cmd) {
393 	case worker_cmd_quit:
394 		verbose(VERB_ALGO, "got control cmd quit");
395 		comm_base_exit(worker->base);
396 		break;
397 	case worker_cmd_stats:
398 		verbose(VERB_ALGO, "got control cmd stats");
399 		server_stats_reply(worker, 1);
400 		break;
401 	case worker_cmd_stats_noreset:
402 		verbose(VERB_ALGO, "got control cmd stats_noreset");
403 		server_stats_reply(worker, 0);
404 		break;
405 	case worker_cmd_remote:
406 		verbose(VERB_ALGO, "got control cmd remote");
407 		daemon_remote_exec(worker);
408 		break;
409 	default:
410 		log_err("bad command %d", (int)cmd);
411 		break;
412 	}
413 }
414 
415 /** check if a delegation is secure */
416 static enum sec_status
417 check_delegation_secure(struct reply_info *rep)
418 {
419 	/* return smallest security status */
420 	size_t i;
421 	enum sec_status sec = sec_status_secure;
422 	enum sec_status s;
423 	size_t num = rep->an_numrrsets + rep->ns_numrrsets;
424 	/* check if answer and authority are OK */
425 	for(i=0; i<num; i++) {
426 		s = ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
427 			->security;
428 		if(s < sec)
429 			sec = s;
430 	}
431 	/* in additional, only unchecked triggers revalidation */
432 	for(i=num; i<rep->rrset_count; i++) {
433 		s = ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
434 			->security;
435 		if(s == sec_status_unchecked)
436 			return s;
437 	}
438 	return sec;
439 }
440 
441 /** remove nonsecure from a delegation referral additional section */
442 static void
443 deleg_remove_nonsecure_additional(struct reply_info* rep)
444 {
445 	/* we can simply edit it, since we are working in the scratch region */
446 	size_t i;
447 	enum sec_status s;
448 
449 	for(i = rep->an_numrrsets+rep->ns_numrrsets; i<rep->rrset_count; i++) {
450 		s = ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
451 			->security;
452 		if(s != sec_status_secure) {
453 			memmove(rep->rrsets+i, rep->rrsets+i+1,
454 				sizeof(struct ub_packed_rrset_key*)*
455 				(rep->rrset_count - i - 1));
456 			rep->ar_numrrsets--;
457 			rep->rrset_count--;
458 			i--;
459 		}
460 	}
461 }
462 
463 /** answer nonrecursive query from the cache */
464 static int
465 answer_norec_from_cache(struct worker* worker, struct query_info* qinfo,
466 	uint16_t id, uint16_t flags, struct comm_reply* repinfo,
467 	struct edns_data* edns)
468 {
469 	/* for a nonrecursive query return either:
470 	 * 	o an error (servfail; we try to avoid this)
471 	 * 	o a delegation (closest we have; this routine tries that)
472 	 * 	o the answer (checked by answer_from_cache)
473 	 *
474 	 * So, grab a delegation from the rrset cache.
475 	 * Then check if it needs validation, if so, this routine fails,
476 	 * so that iterator can prime and validator can verify rrsets.
477 	 */
478 	uint16_t udpsize = edns->udp_size;
479 	int secure = 0;
480 	time_t timenow = *worker->env.now;
481 	int has_cd_bit = (flags&BIT_CD);
482 	int must_validate = (!has_cd_bit || worker->env.cfg->ignore_cd)
483 		&& worker->env.need_to_validate;
484 	struct dns_msg *msg = NULL;
485 	struct delegpt *dp;
486 
487 	dp = dns_cache_find_delegation(&worker->env, qinfo->qname,
488 		qinfo->qname_len, qinfo->qtype, qinfo->qclass,
489 		worker->scratchpad, &msg, timenow, 0, NULL, 0);
490 	if(!dp) { /* no delegation, need to reprime */
491 		return 0;
492 	}
493 	/* In case we have a local alias, copy it into the delegation message.
494 	 * Shallow copy should be fine, as we'll be done with msg in this
495 	 * function. */
496 	msg->qinfo.local_alias = qinfo->local_alias;
497 	if(must_validate) {
498 		switch(check_delegation_secure(msg->rep)) {
499 		case sec_status_unchecked:
500 			/* some rrsets have not been verified yet, go and
501 			 * let validator do that */
502 			return 0;
503 		case sec_status_bogus:
504 		case sec_status_secure_sentinel_fail:
505 			/* some rrsets are bogus, reply servfail */
506 			edns->edns_version = EDNS_ADVERTISED_VERSION;
507 			edns->udp_size = EDNS_ADVERTISED_SIZE;
508 			edns->ext_rcode = 0;
509 			edns->bits &= EDNS_DO;
510 			if(!inplace_cb_reply_servfail_call(&worker->env, qinfo, NULL,
511 				msg->rep, LDNS_RCODE_SERVFAIL, edns, repinfo, worker->scratchpad,
512 				worker->env.now_tv))
513 					return 0;
514 			/* Attach the cached EDE (RFC8914) */
515 			if(worker->env.cfg->ede &&
516 				msg->rep->reason_bogus != LDNS_EDE_NONE) {
517 				edns_opt_list_append_ede(&edns->opt_list_out,
518 					worker->scratchpad, msg->rep->reason_bogus,
519 					msg->rep->reason_bogus_str);
520 			}
521 			error_encode(repinfo->c->buffer, LDNS_RCODE_SERVFAIL,
522 				&msg->qinfo, id, flags, edns);
523 			if(worker->stats.extended) {
524 				worker->stats.ans_bogus++;
525 				worker->stats.ans_rcode[LDNS_RCODE_SERVFAIL]++;
526 			}
527 			return 1;
528 		case sec_status_secure:
529 			/* all rrsets are secure */
530 			/* remove non-secure rrsets from the add. section*/
531 			if(worker->env.cfg->val_clean_additional)
532 				deleg_remove_nonsecure_additional(msg->rep);
533 			secure = 1;
534 			break;
535 		case sec_status_indeterminate:
536 		case sec_status_insecure:
537 		default:
538 			/* not secure */
539 			secure = 0;
540 			break;
541 		}
542 	}
543 	/* return this delegation from the cache */
544 	edns->edns_version = EDNS_ADVERTISED_VERSION;
545 	edns->udp_size = EDNS_ADVERTISED_SIZE;
546 	edns->ext_rcode = 0;
547 	edns->bits &= EDNS_DO;
548 	if(worker->env.cfg->disable_edns_do && (edns->bits & EDNS_DO))
549 		edns->edns_present = 0;
550 	if(!inplace_cb_reply_cache_call(&worker->env, qinfo, NULL, msg->rep,
551 		(int)(flags&LDNS_RCODE_MASK), edns, repinfo, worker->scratchpad,
552 		worker->env.now_tv))
553 			return 0;
554 	msg->rep->flags |= BIT_QR|BIT_RA;
555 	/* Attach the cached EDE (RFC8914) if CD bit is set and the answer is
556 	 * bogus. */
557 	if(worker->env.cfg->ede && has_cd_bit &&
558 		(check_delegation_secure(msg->rep) == sec_status_bogus ||
559 		check_delegation_secure(msg->rep) == sec_status_secure_sentinel_fail) &&
560 		msg->rep->reason_bogus != LDNS_EDE_NONE) {
561 		edns_opt_list_append_ede(&edns->opt_list_out,
562 			worker->scratchpad, msg->rep->reason_bogus,
563 			msg->rep->reason_bogus_str);
564 	}
565 	if(!reply_info_answer_encode(&msg->qinfo, msg->rep, id, flags,
566 		repinfo->c->buffer, 0, 1, worker->scratchpad,
567 		udpsize, edns, (int)(edns->bits & EDNS_DO), secure)) {
568 		if(!inplace_cb_reply_servfail_call(&worker->env, qinfo, NULL, NULL,
569 			LDNS_RCODE_SERVFAIL, edns, repinfo, worker->scratchpad,
570 			worker->env.now_tv))
571 				edns->opt_list_inplace_cb_out = NULL;
572 		error_encode(repinfo->c->buffer, LDNS_RCODE_SERVFAIL,
573 			&msg->qinfo, id, flags, edns);
574 	}
575 	if(worker->stats.extended) {
576 		if(secure) worker->stats.ans_secure++;
577 		server_stats_insrcode(&worker->stats, repinfo->c->buffer);
578 	}
579 	return 1;
580 }
581 
582 /** Apply, if applicable, a response IP action to a cached answer.
583  * If the answer is rewritten as a result of an action, '*encode_repp' will
584  * point to the reply info containing the modified answer.  '*encode_repp' will
585  * be intact otherwise.
586  * It returns 1 on success, 0 otherwise. */
587 static int
588 apply_respip_action(struct worker* worker, const struct query_info* qinfo,
589 	struct respip_client_info* cinfo, struct reply_info* rep,
590 	struct sockaddr_storage* addr, socklen_t addrlen,
591 	struct ub_packed_rrset_key** alias_rrset,
592 	struct reply_info** encode_repp, struct auth_zones* az)
593 {
594 	struct respip_action_info actinfo = {0, 0, 0, 0, NULL, 0, NULL};
595 	actinfo.action = respip_none;
596 
597 	if(qinfo->qtype != LDNS_RR_TYPE_A &&
598 		qinfo->qtype != LDNS_RR_TYPE_AAAA &&
599 		qinfo->qtype != LDNS_RR_TYPE_ANY)
600 		return 1;
601 
602 	if(!respip_rewrite_reply(qinfo, cinfo, rep, encode_repp, &actinfo,
603 		alias_rrset, 0, worker->scratchpad, az, NULL))
604 		return 0;
605 
606 	/* xxx_deny actions mean dropping the reply, unless the original reply
607 	 * was redirected to response-ip data. */
608 	if(actinfo.action == respip_always_deny ||
609 		((actinfo.action == respip_deny ||
610 		actinfo.action == respip_inform_deny) &&
611 		*encode_repp == rep))
612 		*encode_repp = NULL;
613 
614 	/* If address info is returned, it means the action should be an
615 	 * 'inform' variant and the information should be logged. */
616 	if(actinfo.addrinfo) {
617 		respip_inform_print(&actinfo, qinfo->qname,
618 			qinfo->qtype, qinfo->qclass, qinfo->local_alias,
619 			addr, addrlen);
620 
621 		if(worker->stats.extended && actinfo.rpz_used) {
622 			if(actinfo.rpz_disabled)
623 				worker->stats.rpz_action[RPZ_DISABLED_ACTION]++;
624 			if(actinfo.rpz_cname_override)
625 				worker->stats.rpz_action[RPZ_CNAME_OVERRIDE_ACTION]++;
626 			else
627 				worker->stats.rpz_action[
628 					respip_action_to_rpz_action(actinfo.action)]++;
629 		}
630 	}
631 
632 	return 1;
633 }
634 
635 /** answer query from the cache.
636  * Normally, the answer message will be built in repinfo->c->buffer; if the
637  * answer is supposed to be suppressed or the answer is supposed to be an
638  * incomplete CNAME chain, the buffer is explicitly cleared to signal the
639  * caller as such.  In the latter case *partial_rep will point to the incomplete
640  * reply, and this function is (possibly) supposed to be called again with that
641  * *partial_rep value to complete the chain.  In addition, if the query should
642  * be completely dropped, '*need_drop' will be set to 1. */
643 static int
644 answer_from_cache(struct worker* worker, struct query_info* qinfo,
645 	struct respip_client_info* cinfo, int* need_drop, int* is_expired_answer,
646 	int* is_secure_answer, struct ub_packed_rrset_key** alias_rrset,
647 	struct reply_info** partial_repp,
648 	struct reply_info* rep, uint16_t id, uint16_t flags,
649 	struct comm_reply* repinfo, struct edns_data* edns)
650 {
651 	time_t timenow = *worker->env.now;
652 	uint16_t udpsize = edns->udp_size;
653 	struct reply_info* encode_rep = rep;
654 	struct reply_info* partial_rep = *partial_repp;
655 	int has_cd_bit = (flags&BIT_CD);
656 	int must_validate = (!has_cd_bit || worker->env.cfg->ignore_cd)
657 		&& worker->env.need_to_validate;
658 	*partial_repp = NULL;  /* avoid accidental further pass */
659 
660 	/* Check TTL */
661 	if(rep->ttl < timenow) {
662 		/* Check if we need to serve expired now */
663 		if(worker->env.cfg->serve_expired &&
664 			/* if serve-expired-client-timeout is set, serve
665 			 * an expired record without attempting recursion
666 			 * if the serve_expired_norec_ttl is set for the record
667 			 * as we know that recursion is currently failing. */
668 			(!worker->env.cfg->serve_expired_client_timeout ||
669 			 timenow < rep->serve_expired_norec_ttl)
670 #ifdef USE_CACHEDB
671 			&& !(worker->env.cachedb_enabled &&
672 			  worker->env.cfg->cachedb_check_when_serve_expired)
673 #endif
674 			) {
675 				if(!reply_info_can_answer_expired(rep, timenow))
676 					return 0;
677 				if(!rrset_array_lock(rep->ref, rep->rrset_count, 0))
678 					return 0;
679 				*is_expired_answer = 1;
680 		} else {
681 			/* the rrsets may have been updated in the meantime.
682 			 * we will refetch the message format from the
683 			 * authoritative server
684 			 */
685 			return 0;
686 		}
687 	} else {
688 		if(!rrset_array_lock(rep->ref, rep->rrset_count, timenow))
689 			return 0;
690 	}
691 	/* locked and ids and ttls are OK. */
692 
693 	/* check CNAME chain (if any) */
694 	if(rep->an_numrrsets > 0 && (rep->rrsets[0]->rk.type ==
695 		htons(LDNS_RR_TYPE_CNAME) || rep->rrsets[0]->rk.type ==
696 		htons(LDNS_RR_TYPE_DNAME))) {
697 		if(!reply_check_cname_chain(qinfo, rep)) {
698 			/* cname chain invalid, redo iterator steps */
699 			verbose(VERB_ALGO, "Cache reply: cname chain broken");
700 			goto bail_out;
701 		}
702 	}
703 	/* check security status of the cached answer */
704 	if(must_validate && (rep->security == sec_status_bogus ||
705 		rep->security == sec_status_secure_sentinel_fail)) {
706 		/* BAD cached */
707 		edns->edns_version = EDNS_ADVERTISED_VERSION;
708 		edns->udp_size = EDNS_ADVERTISED_SIZE;
709 		edns->ext_rcode = 0;
710 		edns->bits &= EDNS_DO;
711 		if(worker->env.cfg->disable_edns_do && (edns->bits & EDNS_DO))
712 			edns->edns_present = 0;
713 		if(!inplace_cb_reply_servfail_call(&worker->env, qinfo, NULL, rep,
714 			LDNS_RCODE_SERVFAIL, edns, repinfo, worker->scratchpad,
715 			worker->env.now_tv))
716 			goto bail_out;
717 		/* Attach the cached EDE (RFC8914) */
718 		if(worker->env.cfg->ede && rep->reason_bogus != LDNS_EDE_NONE) {
719 			edns_opt_list_append_ede(&edns->opt_list_out,
720 					worker->scratchpad, rep->reason_bogus,
721 					rep->reason_bogus_str);
722 		}
723 		error_encode(repinfo->c->buffer, LDNS_RCODE_SERVFAIL,
724 			qinfo, id, flags, edns);
725 		rrset_array_unlock_touch(worker->env.rrset_cache,
726 			worker->scratchpad, rep->ref, rep->rrset_count);
727 		if(worker->stats.extended) {
728 			worker->stats.ans_bogus ++;
729 			worker->stats.ans_rcode[LDNS_RCODE_SERVFAIL] ++;
730 		}
731 		return 1;
732 	} else if(rep->security == sec_status_unchecked && must_validate) {
733 		verbose(VERB_ALGO, "Cache reply: unchecked entry needs "
734 			"validation");
735 		goto bail_out; /* need to validate cache entry first */
736 	} else if(rep->security == sec_status_secure) {
737 		if(reply_all_rrsets_secure(rep)) {
738 			*is_secure_answer = 1;
739 		} else {
740 			if(must_validate) {
741 				verbose(VERB_ALGO, "Cache reply: secure entry"
742 					" changed status");
743 				goto bail_out; /* rrset changed, re-verify */
744 			}
745 			*is_secure_answer = 0;
746 		}
747 	} else *is_secure_answer = 0;
748 
749 	edns->edns_version = EDNS_ADVERTISED_VERSION;
750 	edns->udp_size = EDNS_ADVERTISED_SIZE;
751 	edns->ext_rcode = 0;
752 	edns->bits &= EDNS_DO;
753 	if(worker->env.cfg->disable_edns_do && (edns->bits & EDNS_DO))
754 		edns->edns_present = 0;
755 	*alias_rrset = NULL; /* avoid confusion if caller set it to non-NULL */
756 	if((worker->daemon->use_response_ip || worker->daemon->use_rpz) &&
757 		!partial_rep && !apply_respip_action(worker, qinfo, cinfo, rep,
758 		&repinfo->client_addr, repinfo->client_addrlen, alias_rrset,
759 		&encode_rep, worker->env.auth_zones)) {
760 		goto bail_out;
761 	} else if(partial_rep &&
762 		!respip_merge_cname(partial_rep, qinfo, rep, cinfo,
763 		must_validate, &encode_rep, worker->scratchpad,
764 		worker->env.auth_zones)) {
765 		goto bail_out;
766 	}
767 	if(encode_rep != rep) {
768 		/* if rewritten, it can't be considered "secure" */
769 		*is_secure_answer = 0;
770 	}
771 	if(!encode_rep || *alias_rrset) {
772 		if(!encode_rep)
773 			*need_drop = 1;
774 		else {
775 			/* If a partial CNAME chain is found, we first need to
776 			 * make a copy of the reply in the scratchpad so we
777 			 * can release the locks and lookup the cache again. */
778 			*partial_repp = reply_info_copy(encode_rep, NULL,
779 				worker->scratchpad);
780 			if(!*partial_repp)
781 				goto bail_out;
782 		}
783 	} else {
784 		if(*is_expired_answer == 1 &&
785 			worker->env.cfg->ede_serve_expired && worker->env.cfg->ede) {
786 			EDNS_OPT_LIST_APPEND_EDE(&edns->opt_list_out,
787 				worker->scratchpad, LDNS_EDE_STALE_ANSWER, "");
788 		}
789 		/* Attach the cached EDE (RFC8914) if CD bit is set and the
790 		 * answer is bogus. */
791 		if(*is_secure_answer == 0 &&
792 			worker->env.cfg->ede && has_cd_bit &&
793 			encode_rep->reason_bogus != LDNS_EDE_NONE) {
794 			edns_opt_list_append_ede(&edns->opt_list_out,
795 				worker->scratchpad, encode_rep->reason_bogus,
796 				encode_rep->reason_bogus_str);
797 		}
798 		if(!inplace_cb_reply_cache_call(&worker->env, qinfo, NULL, encode_rep,
799 			(int)(flags&LDNS_RCODE_MASK), edns, repinfo, worker->scratchpad,
800 			worker->env.now_tv))
801 			goto bail_out;
802 		if(!reply_info_answer_encode(qinfo, encode_rep, id, flags,
803 			repinfo->c->buffer, timenow, 1, worker->scratchpad,
804 			udpsize, edns, (int)(edns->bits & EDNS_DO),
805 			*is_secure_answer)) {
806 			if(!inplace_cb_reply_servfail_call(&worker->env, qinfo,
807 				NULL, NULL, LDNS_RCODE_SERVFAIL, edns, repinfo,
808 				worker->scratchpad, worker->env.now_tv))
809 					edns->opt_list_inplace_cb_out = NULL;
810 			error_encode(repinfo->c->buffer, LDNS_RCODE_SERVFAIL,
811 				qinfo, id, flags, edns);
812 		}
813 	}
814 	/* cannot send the reply right now, because blocking network syscall
815 	 * is bad while holding locks. */
816 	rrset_array_unlock_touch(worker->env.rrset_cache, worker->scratchpad,
817 		rep->ref, rep->rrset_count);
818 	/* go and return this buffer to the client */
819 	return 1;
820 
821 bail_out:
822 	rrset_array_unlock_touch(worker->env.rrset_cache,
823 		worker->scratchpad, rep->ref, rep->rrset_count);
824 	return 0;
825 }
826 
827 /** Reply to client and perform prefetch to keep cache up to date. */
828 static void
829 reply_and_prefetch(struct worker* worker, struct query_info* qinfo,
830 	uint16_t flags, struct comm_reply* repinfo, time_t leeway, int noreply,
831 	int rpz_passthru, struct edns_option* opt_list)
832 {
833 	(void)opt_list;
834 	/* first send answer to client to keep its latency
835 	 * as small as a cachereply */
836 	if(!noreply) {
837 		if(repinfo->c->tcp_req_info) {
838 			sldns_buffer_copy(
839 				repinfo->c->tcp_req_info->spool_buffer,
840 				repinfo->c->buffer);
841 		}
842 		comm_point_send_reply(repinfo);
843 	}
844 	server_stats_prefetch(&worker->stats, worker);
845 #ifdef CLIENT_SUBNET
846 	/* Check if the subnet module is enabled. In that case pass over the
847 	 * comm_reply information for ECS generation later. The mesh states are
848 	 * unique when subnet is enabled. */
849 	if(modstack_find(&worker->env.mesh->mods, "subnetcache") != -1
850 		&& worker->env.unique_mesh) {
851 		mesh_new_prefetch(worker->env.mesh, qinfo, flags, leeway +
852 			PREFETCH_EXPIRY_ADD, rpz_passthru,
853 			&repinfo->client_addr, opt_list);
854 		return;
855 	}
856 #endif
857 	/* create the prefetch in the mesh as a normal lookup without
858 	 * client addrs waiting, which has the cache blacklisted (to bypass
859 	 * the cache and go to the network for the data). */
860 	/* this (potentially) runs the mesh for the new query */
861 	mesh_new_prefetch(worker->env.mesh, qinfo, flags, leeway +
862 		PREFETCH_EXPIRY_ADD, rpz_passthru, NULL, NULL);
863 }
864 
865 /**
866  * Fill CH class answer into buffer. Keeps query.
867  * @param pkt: buffer
868  * @param str: string to put into text record (<255).
869  * 	array of strings, every string becomes a text record.
870  * @param num: number of strings in array.
871  * @param edns: edns reply information.
872  * @param worker: worker with scratch region.
873  * @param repinfo: reply information for a communication point.
874  */
875 static void
876 chaos_replystr(sldns_buffer* pkt, char** str, int num, struct edns_data* edns,
877 	struct worker* worker, struct comm_reply* repinfo)
878 {
879 	int i;
880 	unsigned int rd = LDNS_RD_WIRE(sldns_buffer_begin(pkt));
881 	unsigned int cd = LDNS_CD_WIRE(sldns_buffer_begin(pkt));
882 	size_t udpsize = edns->udp_size;
883 	edns->edns_version = EDNS_ADVERTISED_VERSION;
884 	edns->udp_size = EDNS_ADVERTISED_SIZE;
885 	edns->bits &= EDNS_DO;
886 	if(!inplace_cb_reply_local_call(&worker->env, NULL, NULL, NULL,
887 		LDNS_RCODE_NOERROR, edns, repinfo, worker->scratchpad,
888 		worker->env.now_tv))
889 			edns->opt_list_inplace_cb_out = NULL;
890 	sldns_buffer_clear(pkt);
891 	sldns_buffer_skip(pkt, (ssize_t)sizeof(uint16_t)); /* skip id */
892 	sldns_buffer_write_u16(pkt, (uint16_t)(BIT_QR|BIT_RA));
893 	if(rd) LDNS_RD_SET(sldns_buffer_begin(pkt));
894 	if(cd) LDNS_CD_SET(sldns_buffer_begin(pkt));
895 	sldns_buffer_write_u16(pkt, 1); /* qdcount */
896 	sldns_buffer_write_u16(pkt, (uint16_t)num); /* ancount */
897 	sldns_buffer_write_u16(pkt, 0); /* nscount */
898 	sldns_buffer_write_u16(pkt, 0); /* arcount */
899 	(void)query_dname_len(pkt); /* skip qname */
900 	sldns_buffer_skip(pkt, (ssize_t)sizeof(uint16_t)); /* skip qtype */
901 	sldns_buffer_skip(pkt, (ssize_t)sizeof(uint16_t)); /* skip qclass */
902 	for(i=0; i<num; i++) {
903 		size_t len = strlen(str[i]);
904 		if(len>255) len=255; /* cap size of TXT record */
905 		if(sldns_buffer_position(pkt)+2+2+2+4+2+1+len+
906 			calc_edns_field_size(edns) > udpsize) {
907 			sldns_buffer_write_u16_at(pkt, 6, i); /* ANCOUNT */
908 			LDNS_TC_SET(sldns_buffer_begin(pkt));
909 			break;
910 		}
911 		sldns_buffer_write_u16(pkt, 0xc00c); /* compr ptr to query */
912 		sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_TXT);
913 		sldns_buffer_write_u16(pkt, LDNS_RR_CLASS_CH);
914 		sldns_buffer_write_u32(pkt, 0); /* TTL */
915 		sldns_buffer_write_u16(pkt, sizeof(uint8_t) + len);
916 		sldns_buffer_write_u8(pkt, len);
917 		sldns_buffer_write(pkt, str[i], len);
918 	}
919 	sldns_buffer_flip(pkt);
920 	if(sldns_buffer_capacity(pkt) >=
921 		sldns_buffer_limit(pkt)+calc_edns_field_size(edns))
922 		attach_edns_record(pkt, edns);
923 }
924 
925 /** Reply with one string */
926 static void
927 chaos_replyonestr(sldns_buffer* pkt, const char* str, struct edns_data* edns,
928 	struct worker* worker, struct comm_reply* repinfo)
929 {
930 	chaos_replystr(pkt, (char**)&str, 1, edns, worker, repinfo);
931 }
932 
933 /**
934  * Create CH class trustanchor answer.
935  * @param pkt: buffer
936  * @param edns: edns reply information.
937  * @param w: worker with scratch region.
938  * @param repinfo: reply information for a communication point.
939  */
940 static void
941 chaos_trustanchor(sldns_buffer* pkt, struct edns_data* edns, struct worker* w,
942 	struct comm_reply* repinfo)
943 {
944 #define TA_RESPONSE_MAX_TXT 16 /* max number of TXT records */
945 #define TA_RESPONSE_MAX_TAGS 32 /* max number of tags printed per zone */
946 	char* str_array[TA_RESPONSE_MAX_TXT];
947 	uint16_t tags[TA_RESPONSE_MAX_TAGS];
948 	int num = 0;
949 	struct trust_anchor* ta;
950 
951 	if(!w->env.need_to_validate) {
952 		/* no validator module, reply no trustanchors */
953 		chaos_replystr(pkt, NULL, 0, edns, w, repinfo);
954 		return;
955 	}
956 
957 	/* fill the string with contents */
958 	lock_basic_lock(&w->env.anchors->lock);
959 	RBTREE_FOR(ta, struct trust_anchor*, w->env.anchors->tree) {
960 		char* str;
961 		size_t i, numtag, str_len = 255;
962 		if(num == TA_RESPONSE_MAX_TXT) continue;
963 		str = (char*)regional_alloc(w->scratchpad, str_len);
964 		if(!str) continue;
965 		lock_basic_lock(&ta->lock);
966 		numtag = anchor_list_keytags(ta, tags, TA_RESPONSE_MAX_TAGS);
967 		if(numtag == 0) {
968 			/* empty, insecure point */
969 			lock_basic_unlock(&ta->lock);
970 			continue;
971 		}
972 		str_array[num] = str;
973 		num++;
974 
975 		/* spool name of anchor */
976 		(void)sldns_wire2str_dname_buf(ta->name, ta->namelen, str, str_len);
977 		str_len -= strlen(str); str += strlen(str);
978 		/* spool tags */
979 		for(i=0; i<numtag; i++) {
980 			snprintf(str, str_len, " %u", (unsigned)tags[i]);
981 			str_len -= strlen(str); str += strlen(str);
982 		}
983 		lock_basic_unlock(&ta->lock);
984 	}
985 	lock_basic_unlock(&w->env.anchors->lock);
986 
987 	chaos_replystr(pkt, str_array, num, edns, w, repinfo);
988 	regional_free_all(w->scratchpad);
989 }
990 
991 /**
992  * Answer CH class queries.
993  * @param w: worker
994  * @param qinfo: query info. Pointer into packet buffer.
995  * @param edns: edns info from query.
996  * @param repinfo: reply information for a communication point.
997  * @param pkt: packet buffer.
998  * @return: true if a reply is to be sent.
999  */
1000 static int
1001 answer_chaos(struct worker* w, struct query_info* qinfo,
1002 	struct edns_data* edns, struct comm_reply* repinfo, sldns_buffer* pkt)
1003 {
1004 	struct config_file* cfg = w->env.cfg;
1005 	if(qinfo->qtype != LDNS_RR_TYPE_ANY && qinfo->qtype != LDNS_RR_TYPE_TXT)
1006 		return 0;
1007 	if(query_dname_compare(qinfo->qname,
1008 		(uint8_t*)"\002id\006server") == 0 ||
1009 		query_dname_compare(qinfo->qname,
1010 		(uint8_t*)"\010hostname\004bind") == 0)
1011 	{
1012 		if(cfg->hide_identity)
1013 			return 0;
1014 		if(cfg->identity==NULL || cfg->identity[0]==0) {
1015 			char buf[MAXHOSTNAMELEN+1];
1016 			if (gethostname(buf, MAXHOSTNAMELEN) == 0) {
1017 				buf[MAXHOSTNAMELEN] = 0;
1018 				chaos_replyonestr(pkt, buf, edns, w, repinfo);
1019 			} else 	{
1020 				log_err("gethostname: %s", strerror(errno));
1021 				chaos_replyonestr(pkt, "no hostname", edns, w, repinfo);
1022 			}
1023 		}
1024 		else 	chaos_replyonestr(pkt, cfg->identity, edns, w, repinfo);
1025 		return 1;
1026 	}
1027 	if(query_dname_compare(qinfo->qname,
1028 		(uint8_t*)"\007version\006server") == 0 ||
1029 		query_dname_compare(qinfo->qname,
1030 		(uint8_t*)"\007version\004bind") == 0)
1031 	{
1032 		if(cfg->hide_version)
1033 			return 0;
1034 		if(cfg->version==NULL || cfg->version[0]==0)
1035 			chaos_replyonestr(pkt, PACKAGE_STRING, edns, w, repinfo);
1036 		else 	chaos_replyonestr(pkt, cfg->version, edns, w, repinfo);
1037 		return 1;
1038 	}
1039 	if(query_dname_compare(qinfo->qname,
1040 		(uint8_t*)"\013trustanchor\007unbound") == 0)
1041 	{
1042 		if(cfg->hide_trustanchor)
1043 			return 0;
1044 		chaos_trustanchor(pkt, edns, w, repinfo);
1045 		return 1;
1046 	}
1047 
1048 	return 0;
1049 }
1050 
1051 /**
1052  * Answer notify queries.  These are notifies for authoritative zones,
1053  * the reply is an ack that the notify has been received.  We need to check
1054  * access permission here.
1055  * @param w: worker
1056  * @param qinfo: query info. Pointer into packet buffer.
1057  * @param edns: edns info from query.
1058  * @param addr: client address.
1059  * @param addrlen: client address length.
1060  * @param pkt: packet buffer.
1061  */
1062 static void
1063 answer_notify(struct worker* w, struct query_info* qinfo,
1064 	struct edns_data* edns, sldns_buffer* pkt,
1065 	struct sockaddr_storage* addr, socklen_t addrlen)
1066 {
1067 	int refused = 0;
1068 	int rcode = LDNS_RCODE_NOERROR;
1069 	uint32_t serial = 0;
1070 	int has_serial;
1071 	if(!w->env.auth_zones) return;
1072 	has_serial = auth_zone_parse_notify_serial(pkt, &serial);
1073 	if(auth_zones_notify(w->env.auth_zones, &w->env, qinfo->qname,
1074 		qinfo->qname_len, qinfo->qclass, addr,
1075 		addrlen, has_serial, serial, &refused)) {
1076 		rcode = LDNS_RCODE_NOERROR;
1077 	} else {
1078 		if(refused)
1079 			rcode = LDNS_RCODE_REFUSED;
1080 		else	rcode = LDNS_RCODE_SERVFAIL;
1081 	}
1082 
1083 	if(verbosity >= VERB_DETAIL) {
1084 		char buf[380];
1085 		char zname[255+1];
1086 		char sr[25];
1087 		dname_str(qinfo->qname, zname);
1088 		sr[0]=0;
1089 		if(has_serial)
1090 			snprintf(sr, sizeof(sr), "serial %u ",
1091 				(unsigned)serial);
1092 		if(rcode == LDNS_RCODE_REFUSED)
1093 			snprintf(buf, sizeof(buf),
1094 				"refused NOTIFY %sfor %s from", sr, zname);
1095 		else if(rcode == LDNS_RCODE_SERVFAIL)
1096 			snprintf(buf, sizeof(buf),
1097 				"servfail for NOTIFY %sfor %s from", sr, zname);
1098 		else	snprintf(buf, sizeof(buf),
1099 				"received NOTIFY %sfor %s from", sr, zname);
1100 		log_addr(VERB_DETAIL, buf, addr, addrlen);
1101 	}
1102 	edns->edns_version = EDNS_ADVERTISED_VERSION;
1103 	edns->udp_size = EDNS_ADVERTISED_SIZE;
1104 	edns->ext_rcode = 0;
1105 	edns->bits &= EDNS_DO;
1106 	error_encode(pkt, rcode, qinfo,
1107 		*(uint16_t*)(void *)sldns_buffer_begin(pkt),
1108 		sldns_buffer_read_u16_at(pkt, 2), edns);
1109 	LDNS_OPCODE_SET(sldns_buffer_begin(pkt), LDNS_PACKET_NOTIFY);
1110 }
1111 
1112 static int
1113 deny_refuse(struct comm_point* c, enum acl_access acl,
1114 	enum acl_access deny, enum acl_access refuse,
1115 	struct worker* worker, struct comm_reply* repinfo,
1116 	struct acl_addr* acladdr, int ede,
1117 	struct check_request_result* check_result)
1118 {
1119 	if(acl == deny) {
1120 		if(verbosity >= VERB_ALGO) {
1121 			log_acl_action("dropped", &repinfo->client_addr,
1122 				repinfo->client_addrlen, acl, acladdr);
1123 			log_buf(VERB_ALGO, "dropped", c->buffer);
1124 		}
1125 		comm_point_drop_reply(repinfo);
1126 		if(worker->stats.extended)
1127 			worker->stats.unwanted_queries++;
1128 		return 0;
1129 	} else if(acl == refuse) {
1130 		size_t opt_rr_mark;
1131 
1132 		if(verbosity >= VERB_ALGO) {
1133 			log_acl_action("refused", &repinfo->client_addr,
1134 				repinfo->client_addrlen, acl, acladdr);
1135 			log_buf(VERB_ALGO, "refuse", c->buffer);
1136 		}
1137 
1138 		if(worker->stats.extended)
1139 			worker->stats.unwanted_queries++;
1140 		worker_check_request(c->buffer, worker, check_result);
1141 		if(check_result->value != 0) {
1142 			if(check_result->value != -1) {
1143 				LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1144 				LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1145 					check_result->value);
1146 				return 1;
1147 			}
1148 			comm_point_drop_reply(repinfo);
1149 			return 0;
1150 		}
1151 		/* worker_check_request() above guarantees that the buffer contains at
1152 		 * least a header and that qdcount == 1
1153 		 */
1154 		log_assert(sldns_buffer_limit(c->buffer) >= LDNS_HEADER_SIZE
1155 			&& LDNS_QDCOUNT(sldns_buffer_begin(c->buffer)) == 1);
1156 
1157 		sldns_buffer_set_position(c->buffer, LDNS_HEADER_SIZE); /* skip header */
1158 
1159 		/* check additional section is present and that we respond with EDEs */
1160 		if(LDNS_ARCOUNT(sldns_buffer_begin(c->buffer)) != 1
1161 			|| !ede) {
1162 			LDNS_QDCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1163 			LDNS_ANCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1164 			LDNS_NSCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1165 			LDNS_ARCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1166 			LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1167 			LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1168 				LDNS_RCODE_REFUSED);
1169 			sldns_buffer_set_position(c->buffer, LDNS_HEADER_SIZE);
1170 			sldns_buffer_flip(c->buffer);
1171 			return 1;
1172 		}
1173 
1174 		if (!query_dname_len(c->buffer)) {
1175 			LDNS_QDCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1176 			LDNS_ANCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1177 			LDNS_NSCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1178 			LDNS_ARCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1179 			LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1180 			LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1181 				LDNS_RCODE_FORMERR);
1182 			sldns_buffer_set_position(c->buffer, LDNS_HEADER_SIZE);
1183 			sldns_buffer_flip(c->buffer);
1184 			return 1;
1185 		}
1186 		/* space available for query type and class? */
1187 		if (sldns_buffer_remaining(c->buffer) < 2 * sizeof(uint16_t)) {
1188                         LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1189                         LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1190 				 LDNS_RCODE_FORMERR);
1191 			LDNS_QDCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1192 			LDNS_ANCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1193 			LDNS_NSCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1194 			LDNS_ARCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1195 			sldns_buffer_set_position(c->buffer, LDNS_HEADER_SIZE);
1196                         sldns_buffer_flip(c->buffer);
1197 			return 1;
1198 		}
1199 		LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1200 		LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1201 			LDNS_RCODE_REFUSED);
1202 
1203 		sldns_buffer_skip(c->buffer, (ssize_t)sizeof(uint16_t)); /* skip qtype */
1204 
1205 		sldns_buffer_skip(c->buffer, (ssize_t)sizeof(uint16_t)); /* skip qclass */
1206 
1207 		/* The OPT RR to be returned should come directly after
1208 		 * the query, so mark this spot.
1209 		 */
1210 		opt_rr_mark = sldns_buffer_position(c->buffer);
1211 
1212 		/* Skip through the RR records */
1213 		if(LDNS_ANCOUNT(sldns_buffer_begin(c->buffer)) != 0 ||
1214 			LDNS_NSCOUNT(sldns_buffer_begin(c->buffer)) != 0) {
1215 			if(!skip_pkt_rrs(c->buffer,
1216 				((int)LDNS_ANCOUNT(sldns_buffer_begin(c->buffer)))+
1217 				((int)LDNS_NSCOUNT(sldns_buffer_begin(c->buffer))))) {
1218 				LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1219 					LDNS_RCODE_FORMERR);
1220 				LDNS_ANCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1221 				LDNS_NSCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1222 				LDNS_ARCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1223 				sldns_buffer_set_position(c->buffer, opt_rr_mark);
1224 				sldns_buffer_flip(c->buffer);
1225 				return 1;
1226 			}
1227 		}
1228 		/* Do we have a valid OPT RR here? If not return REFUSED (could be a valid TSIG or something so no FORMERR) */
1229 		/* domain name must be the root of length 1. */
1230 		if(sldns_buffer_remaining(c->buffer) < 1 || *sldns_buffer_current(c->buffer) != 0) {
1231 			LDNS_ANCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1232 			LDNS_NSCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1233 			LDNS_ARCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1234 			sldns_buffer_set_position(c->buffer, opt_rr_mark);
1235 			sldns_buffer_flip(c->buffer);
1236 			return 1;
1237 		} else {
1238 			sldns_buffer_skip(c->buffer, 1); /* skip root label */
1239 		}
1240 		if(sldns_buffer_remaining(c->buffer) < 2 ||
1241 			sldns_buffer_read_u16(c->buffer) != LDNS_RR_TYPE_OPT) {
1242 			LDNS_ANCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1243 			LDNS_NSCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1244 			LDNS_ARCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1245 			sldns_buffer_set_position(c->buffer, opt_rr_mark);
1246 			sldns_buffer_flip(c->buffer);
1247 			return 1;
1248 		}
1249 		/* Write OPT RR directly after the query,
1250 		 * so without the (possibly skipped) Answer and NS RRs
1251 		 */
1252 		LDNS_ANCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1253 		LDNS_NSCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1254 		sldns_buffer_clear(c->buffer); /* reset write limit */
1255 		sldns_buffer_set_position(c->buffer, opt_rr_mark);
1256 
1257 		/* Check if OPT record can be written
1258 		 * 17 == root label (1) + RR type (2) + UDP Size (2)
1259 		 *     + Fields (4) + rdata len (2) + EDE Option code (2)
1260 		 *     + EDE Option length (2) + EDE info-code (2)
1261 		 */
1262 		if (sldns_buffer_available(c->buffer, 17) == 0) {
1263 			LDNS_ARCOUNT_SET(sldns_buffer_begin(c->buffer), 0);
1264 			sldns_buffer_flip(c->buffer);
1265 			return 1;
1266 		}
1267 
1268 		LDNS_ARCOUNT_SET(sldns_buffer_begin(c->buffer), 1);
1269 
1270 		/* root label */
1271 		sldns_buffer_write_u8(c->buffer, 0);
1272 		sldns_buffer_write_u16(c->buffer, LDNS_RR_TYPE_OPT);
1273 		sldns_buffer_write_u16(c->buffer, EDNS_ADVERTISED_SIZE);
1274 
1275 		/* write OPT Record TTL Field */
1276 		sldns_buffer_write_u32(c->buffer, 0);
1277 
1278 		/* write rdata len: EDE option + length + info-code */
1279 		sldns_buffer_write_u16(c->buffer, 6);
1280 
1281 		/* write OPTIONS; add EDE option code */
1282 		sldns_buffer_write_u16(c->buffer, LDNS_EDNS_EDE);
1283 
1284 		/* write single EDE option length (for just 1 info-code) */
1285 		sldns_buffer_write_u16(c->buffer, 2);
1286 
1287 		/* write single EDE info-code */
1288 		sldns_buffer_write_u16(c->buffer, LDNS_EDE_PROHIBITED);
1289 
1290 		sldns_buffer_flip(c->buffer);
1291 
1292 		verbose(VERB_ALGO, "attached EDE code: %d", LDNS_EDE_PROHIBITED);
1293 
1294 		return 1;
1295 
1296 	}
1297 
1298 	return -1;
1299 }
1300 
1301 static int
1302 deny_refuse_all(struct comm_point* c, enum acl_access* acl,
1303 	struct worker* worker, struct comm_reply* repinfo,
1304 	struct acl_addr** acladdr, int ede, int check_proxy,
1305 	struct check_request_result* check_result)
1306 {
1307 	if(check_proxy) {
1308 		*acladdr = acl_addr_lookup(worker->daemon->acl,
1309 			&repinfo->remote_addr, repinfo->remote_addrlen);
1310 	} else {
1311 		*acladdr = acl_addr_lookup(worker->daemon->acl,
1312 			&repinfo->client_addr, repinfo->client_addrlen);
1313 	}
1314 	/* If there is no ACL based on client IP use the interface ACL. */
1315 	if(!(*acladdr) && c->socket) {
1316 		*acladdr = c->socket->acl;
1317 	}
1318 	*acl = acl_get_control(*acladdr);
1319 	return deny_refuse(c, *acl, acl_deny, acl_refuse, worker, repinfo,
1320 		*acladdr, ede, check_result);
1321 }
1322 
1323 static int
1324 deny_refuse_non_local(struct comm_point* c, enum acl_access acl,
1325 	struct worker* worker, struct comm_reply* repinfo,
1326 	struct acl_addr* acladdr, int ede,
1327 	struct check_request_result* check_result)
1328 {
1329 	return deny_refuse(c, acl, acl_deny_non_local, acl_refuse_non_local,
1330 		worker, repinfo, acladdr, ede, check_result);
1331 }
1332 
1333 /* Check if the query is blocked by source IP rate limiting.
1334  * Returns 1 if it passes the check, 0 otherwise. */
1335 static int
1336 check_ip_ratelimit(struct worker* worker, struct sockaddr_storage* addr,
1337 	socklen_t addrlen, int has_cookie, sldns_buffer* pkt)
1338 {
1339 	if(!infra_ip_ratelimit_inc(worker->env.infra_cache, addr, addrlen,
1340 			*worker->env.now, has_cookie,
1341 			worker->env.cfg->ip_ratelimit_backoff, pkt)) {
1342 		/* See if we can pass through with slip factor */
1343 		if(!has_cookie && worker->env.cfg->ip_ratelimit_factor != 0 &&
1344 			ub_random_max(worker->env.rnd,
1345 			worker->env.cfg->ip_ratelimit_factor) == 0) {
1346 			char addrbuf[128];
1347 			addr_to_str(addr, addrlen, addrbuf, sizeof(addrbuf));
1348 			verbose(VERB_QUERY, "ip_ratelimit allowed through for "
1349 				"ip address %s because of slip in "
1350 				"ip_ratelimit_factor", addrbuf);
1351 			return 1;
1352 		}
1353 		return 0;
1354 	}
1355 	return 1;
1356 }
1357 
1358 int
1359 worker_handle_request(struct comm_point* c, void* arg, int error,
1360 	struct comm_reply* repinfo)
1361 {
1362 	struct worker* worker = (struct worker*)arg;
1363 	int ret;
1364 	hashvalue_type h;
1365 	struct lruhash_entry* e;
1366 	struct query_info qinfo;
1367 	struct edns_data edns;
1368 	struct edns_option* original_edns_list = NULL;
1369 	enum acl_access acl;
1370 	struct acl_addr* acladdr;
1371 	int pre_edns_ip_ratelimit = 1;
1372 	int rc = 0;
1373 	int need_drop = 0;
1374 	int is_expired_answer = 0;
1375 	int is_secure_answer = 0;
1376 	int rpz_passthru = 0;
1377 	long long wait_queue_time = 0;
1378 	/* We might have to chase a CNAME chain internally, in which case
1379 	 * we'll have up to two replies and combine them to build a complete
1380 	 * answer.  These variables control this case. */
1381 	struct ub_packed_rrset_key* alias_rrset = NULL;
1382 	struct reply_info* partial_rep = NULL;
1383 	struct query_info* lookup_qinfo = &qinfo;
1384 	struct query_info qinfo_tmp; /* placeholder for lookup_qinfo */
1385 	struct respip_client_info* cinfo = NULL, cinfo_tmp;
1386 	struct timeval wait_time;
1387 	struct check_request_result check_result = {0,0};
1388 	memset(&qinfo, 0, sizeof(qinfo));
1389 
1390 	if((error != NETEVENT_NOERROR && error != NETEVENT_DONE)|| !repinfo) {
1391 		/* some bad tcp query DNS formats give these error calls */
1392 		verbose(VERB_ALGO, "handle request called with err=%d", error);
1393 		return 0;
1394 	}
1395 
1396 	if (worker->env.cfg->sock_queue_timeout && timeval_isset(&c->recv_tv)) {
1397 		timeval_subtract(&wait_time, worker->env.now_tv, &c->recv_tv);
1398 		wait_queue_time = wait_time.tv_sec * 1000000 +  wait_time.tv_usec;
1399 		if (worker->stats.max_query_time_us < wait_queue_time)
1400 			worker->stats.max_query_time_us = wait_queue_time;
1401 		if(wait_queue_time >
1402 			(long long)(worker->env.cfg->sock_queue_timeout * 1000000)) {
1403 			/* count and drop queries that were sitting in the socket queue too long */
1404 			worker->stats.num_queries_timed_out++;
1405 			return 0;
1406 		}
1407 	}
1408 
1409 #ifdef USE_DNSCRYPT
1410 	repinfo->max_udp_size = worker->daemon->cfg->max_udp_size;
1411 	if(!dnsc_handle_curved_request(worker->daemon->dnscenv, repinfo)) {
1412 		worker->stats.num_query_dnscrypt_crypted_malformed++;
1413 		return 0;
1414 	}
1415 	if(c->dnscrypt && !repinfo->is_dnscrypted) {
1416 		char buf[LDNS_MAX_DOMAINLEN+1];
1417 		/* Check if this is unencrypted and asking for certs */
1418 		worker_check_request(c->buffer, worker, &check_result);
1419 		if(check_result.value != 0) {
1420 			verbose(VERB_ALGO,
1421 				"dnscrypt: worker check request: bad query.");
1422 			log_addr(VERB_CLIENT,"from",&repinfo->client_addr,
1423 				repinfo->client_addrlen);
1424 			comm_point_drop_reply(repinfo);
1425 			return 0;
1426 		}
1427 		if(!query_info_parse(&qinfo, c->buffer)) {
1428 			verbose(VERB_ALGO,
1429 				"dnscrypt: worker parse request: formerror.");
1430 			log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1431 				repinfo->client_addrlen);
1432 			comm_point_drop_reply(repinfo);
1433 			return 0;
1434 		}
1435 		dname_str(qinfo.qname, buf);
1436 		if(!(qinfo.qtype == LDNS_RR_TYPE_TXT &&
1437 			strcasecmp(buf,
1438 			worker->daemon->dnscenv->provider_name) == 0)) {
1439 			verbose(VERB_ALGO,
1440 				"dnscrypt: not TXT \"%s\". Received: %s \"%s\"",
1441 				worker->daemon->dnscenv->provider_name,
1442 				sldns_rr_descript(qinfo.qtype)->_name,
1443 				buf);
1444 			comm_point_drop_reply(repinfo);
1445 			worker->stats.num_query_dnscrypt_cleartext++;
1446 			return 0;
1447 		}
1448 		worker->stats.num_query_dnscrypt_cert++;
1449 		sldns_buffer_rewind(c->buffer);
1450 	} else if(c->dnscrypt && repinfo->is_dnscrypted) {
1451 		worker->stats.num_query_dnscrypt_crypted++;
1452 	}
1453 #endif
1454 #ifdef USE_DNSTAP
1455 	/*
1456 	 * sending src (client)/dst (local service) addresses over DNSTAP from incoming request handler
1457 	 */
1458 	if(worker->dtenv.log_client_query_messages) {
1459 		log_addr(VERB_ALGO, "request from client", &repinfo->client_addr, repinfo->client_addrlen);
1460 		log_addr(VERB_ALGO, "to local addr", (void*)repinfo->c->socket->addr, repinfo->c->socket->addrlen);
1461 		dt_msg_send_client_query(&worker->dtenv, &repinfo->client_addr, (void*)repinfo->c->socket->addr, c->type, c->ssl, c->buffer,
1462 		((worker->env.cfg->sock_queue_timeout && timeval_isset(&c->recv_tv))?&c->recv_tv:NULL));
1463 	}
1464 #endif
1465 	/* Check deny/refuse ACLs */
1466 	if(repinfo->is_proxied) {
1467 		if((ret=deny_refuse_all(c, &acl, worker, repinfo, &acladdr,
1468 			worker->env.cfg->ede, 1, &check_result)) != -1) {
1469 			if(ret == 1)
1470 				goto send_reply;
1471 			return ret;
1472 		}
1473 	}
1474 	if((ret=deny_refuse_all(c, &acl, worker, repinfo, &acladdr,
1475 		worker->env.cfg->ede, 0, &check_result)) != -1) {
1476 		if(ret == 1)
1477 			goto send_reply;
1478 		return ret;
1479 	}
1480 
1481 	worker_check_request(c->buffer, worker, &check_result);
1482 	if(check_result.value != 0) {
1483 		verbose(VERB_ALGO, "worker check request: bad query.");
1484 		log_addr(VERB_CLIENT,"from",&repinfo->client_addr, repinfo->client_addrlen);
1485 		if(check_result.value != -1) {
1486 			LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1487 			LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1488 				check_result.value);
1489 			return 1;
1490 		}
1491 		comm_point_drop_reply(repinfo);
1492 		return 0;
1493 	}
1494 
1495 	worker->stats.num_queries++;
1496 	pre_edns_ip_ratelimit = !worker->env.cfg->do_answer_cookie
1497 		|| sldns_buffer_limit(c->buffer) < LDNS_HEADER_SIZE
1498 		|| LDNS_ARCOUNT(sldns_buffer_begin(c->buffer)) == 0;
1499 
1500 	/* If the IP rate limiting check needs extra EDNS information (e.g.,
1501 	 * DNS Cookies) postpone the check until after EDNS is parsed. */
1502 	if(pre_edns_ip_ratelimit) {
1503 		/* NOTE: we always check the repinfo->client_address.
1504 		 *       IP ratelimiting is implicitly disabled for proxies. */
1505 		if(!check_ip_ratelimit(worker, &repinfo->client_addr,
1506 			repinfo->client_addrlen, 0, c->buffer)) {
1507 			worker->stats.num_queries_ip_ratelimited++;
1508 			comm_point_drop_reply(repinfo);
1509 			return 0;
1510 		}
1511 	}
1512 
1513 	if(!query_info_parse(&qinfo, c->buffer)) {
1514 		verbose(VERB_ALGO, "worker parse request: formerror.");
1515 		log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1516 			repinfo->client_addrlen);
1517 		memset(&qinfo, 0, sizeof(qinfo)); /* zero qinfo.qname */
1518 		if(worker_err_ratelimit(worker, LDNS_RCODE_FORMERR) == -1) {
1519 			comm_point_drop_reply(repinfo);
1520 			return 0;
1521 		}
1522 		sldns_buffer_rewind(c->buffer);
1523 		LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1524 		LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1525 			LDNS_RCODE_FORMERR);
1526 		goto send_reply;
1527 	}
1528 	if(worker->env.cfg->log_queries) {
1529 		char ip[128];
1530 		addr_to_str(&repinfo->client_addr, repinfo->client_addrlen, ip, sizeof(ip));
1531 		log_query_in(ip, qinfo.qname, qinfo.qtype, qinfo.qclass);
1532 	}
1533 	if(qinfo.qtype == LDNS_RR_TYPE_AXFR ||
1534 		qinfo.qtype == LDNS_RR_TYPE_IXFR) {
1535 		verbose(VERB_ALGO, "worker request: refused zone transfer.");
1536 		log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1537 			repinfo->client_addrlen);
1538 		sldns_buffer_rewind(c->buffer);
1539 		LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1540 		LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1541 			LDNS_RCODE_REFUSED);
1542 		if(worker->stats.extended) {
1543 			worker->stats.qtype[qinfo.qtype]++;
1544 		}
1545 		goto send_reply;
1546 	}
1547 	if(qinfo.qtype == LDNS_RR_TYPE_OPT ||
1548 		qinfo.qtype == LDNS_RR_TYPE_TSIG ||
1549 		qinfo.qtype == LDNS_RR_TYPE_TKEY ||
1550 		qinfo.qtype == LDNS_RR_TYPE_MAILA ||
1551 		qinfo.qtype == LDNS_RR_TYPE_MAILB ||
1552 		(qinfo.qtype >= 128 && qinfo.qtype <= 248)) {
1553 		verbose(VERB_ALGO, "worker request: formerror for meta-type.");
1554 		log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1555 			repinfo->client_addrlen);
1556 		if(worker_err_ratelimit(worker, LDNS_RCODE_FORMERR) == -1) {
1557 			comm_point_drop_reply(repinfo);
1558 			return 0;
1559 		}
1560 		sldns_buffer_rewind(c->buffer);
1561 		LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1562 		LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1563 			LDNS_RCODE_FORMERR);
1564 		if(worker->stats.extended) {
1565 			worker->stats.qtype[qinfo.qtype]++;
1566 		}
1567 		goto send_reply;
1568 	}
1569 	if((ret=parse_edns_from_query_pkt(
1570 			c->buffer, &edns, worker->env.cfg, c, repinfo,
1571 			(worker->env.now ? *worker->env.now : time(NULL)),
1572 			worker->scratchpad,
1573 			worker->daemon->cookie_secrets)) != 0) {
1574 		struct edns_data reply_edns;
1575 		verbose(VERB_ALGO, "worker parse edns: formerror.");
1576 		log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1577 			repinfo->client_addrlen);
1578 		memset(&reply_edns, 0, sizeof(reply_edns));
1579 		reply_edns.edns_present = 1;
1580 		error_encode(c->buffer, ret, &qinfo,
1581 			*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
1582 			sldns_buffer_read_u16_at(c->buffer, 2), &reply_edns);
1583 		regional_free_all(worker->scratchpad);
1584 		goto send_reply;
1585 	}
1586 	if(edns.edns_present) {
1587 		if(edns.edns_version != 0) {
1588 			edns.opt_list_in = NULL;
1589 			edns.opt_list_out = NULL;
1590 			edns.opt_list_inplace_cb_out = NULL;
1591 			verbose(VERB_ALGO, "query with bad edns version.");
1592 			log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1593 				repinfo->client_addrlen);
1594 			extended_error_encode(c->buffer, EDNS_RCODE_BADVERS, &qinfo,
1595 				*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
1596 				sldns_buffer_read_u16_at(c->buffer, 2), 0, &edns);
1597 			regional_free_all(worker->scratchpad);
1598 			goto send_reply;
1599 		}
1600 		if(edns.udp_size < NORMAL_UDP_SIZE &&
1601 		   worker->daemon->cfg->harden_short_bufsize) {
1602 			verbose(VERB_QUERY, "worker request: EDNS bufsize %d ignored",
1603 				(int)edns.udp_size);
1604 			log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1605 				repinfo->client_addrlen);
1606 			edns.udp_size = NORMAL_UDP_SIZE;
1607 		}
1608 	}
1609 
1610 	/* Get stats for cookies */
1611 	server_stats_downstream_cookie(&worker->stats, &edns);
1612 
1613 	/* If the IP rate limiting check was postponed, check now. */
1614 	if(!pre_edns_ip_ratelimit) {
1615 		/* NOTE: we always check the repinfo->client_address.
1616 		 *       IP ratelimiting is implicitly disabled for proxies. */
1617 		if(!check_ip_ratelimit(worker, &repinfo->client_addr,
1618 			repinfo->client_addrlen, edns.cookie_valid,
1619 			c->buffer)) {
1620 			worker->stats.num_queries_ip_ratelimited++;
1621 			comm_point_drop_reply(repinfo);
1622 			return 0;
1623 		}
1624 	}
1625 
1626 	/* "if, else if" sequence below deals with downstream DNS Cookies */
1627 	if(acl != acl_allow_cookie)
1628 		; /* pass; No cookie downstream processing whatsoever */
1629 
1630 	else if(edns.cookie_valid)
1631 		; /* pass; Valid cookie is good! */
1632 
1633 	else if(c->type != comm_udp)
1634 		; /* pass; Stateful transport */
1635 
1636 	else if(edns.cookie_present) {
1637 		/* Cookie present, but not valid: Cookie was bad! */
1638 		extended_error_encode(c->buffer,
1639 			LDNS_EXT_RCODE_BADCOOKIE, &qinfo,
1640 			*(uint16_t*)(void *)
1641 			sldns_buffer_begin(c->buffer),
1642 			sldns_buffer_read_u16_at(c->buffer, 2),
1643 			0, &edns);
1644 		regional_free_all(worker->scratchpad);
1645 		goto send_reply;
1646 	} else {
1647 		/* Cookie required, but no cookie present on UDP */
1648 		verbose(VERB_ALGO, "worker request: "
1649 			"need cookie or stateful transport");
1650 		log_addr(VERB_ALGO, "from",&repinfo->remote_addr
1651 		                          , repinfo->remote_addrlen);
1652 		EDNS_OPT_LIST_APPEND_EDE(&edns.opt_list_out,
1653 			worker->scratchpad, LDNS_EDE_OTHER,
1654 			"DNS Cookie needed for UDP replies");
1655 		error_encode(c->buffer,
1656 			(LDNS_RCODE_REFUSED|BIT_TC), &qinfo,
1657 			*(uint16_t*)(void *)
1658 			sldns_buffer_begin(c->buffer),
1659 			sldns_buffer_read_u16_at(c->buffer, 2),
1660 			&edns);
1661 		regional_free_all(worker->scratchpad);
1662 		goto send_reply;
1663 	}
1664 
1665 	if(edns.udp_size > worker->daemon->cfg->max_udp_size &&
1666 		c->type == comm_udp) {
1667 		verbose(VERB_QUERY,
1668 			"worker request: max UDP reply size modified"
1669 			" (%d to max-udp-size)", (int)edns.udp_size);
1670 		log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1671 			repinfo->client_addrlen);
1672 		edns.udp_size = worker->daemon->cfg->max_udp_size;
1673 	}
1674 	if(edns.udp_size < LDNS_HEADER_SIZE) {
1675 		verbose(VERB_ALGO, "worker request: edns is too small.");
1676 		log_addr(VERB_CLIENT, "from", &repinfo->client_addr,
1677 			repinfo->client_addrlen);
1678 		LDNS_QR_SET(sldns_buffer_begin(c->buffer));
1679 		LDNS_TC_SET(sldns_buffer_begin(c->buffer));
1680 		LDNS_RCODE_SET(sldns_buffer_begin(c->buffer),
1681 			LDNS_RCODE_SERVFAIL);
1682 		sldns_buffer_set_position(c->buffer, LDNS_HEADER_SIZE);
1683 		sldns_buffer_write_at(c->buffer, 4,
1684 			(uint8_t*)"\0\0\0\0\0\0\0\0", 8);
1685 		sldns_buffer_flip(c->buffer);
1686 		regional_free_all(worker->scratchpad);
1687 		goto send_reply;
1688 	}
1689 	if(worker->stats.extended)
1690 		server_stats_insquery(&worker->stats, c, qinfo.qtype,
1691 			qinfo.qclass, &edns, repinfo);
1692 	if(c->type != comm_udp)
1693 		edns.udp_size = 65535; /* max size for TCP replies */
1694 	if(qinfo.qclass == LDNS_RR_CLASS_CH && answer_chaos(worker, &qinfo,
1695 		&edns, repinfo, c->buffer)) {
1696 		regional_free_all(worker->scratchpad);
1697 		goto send_reply;
1698 	}
1699 	if(LDNS_OPCODE_WIRE(sldns_buffer_begin(c->buffer)) ==
1700 		LDNS_PACKET_NOTIFY) {
1701 		answer_notify(worker, &qinfo, &edns, c->buffer,
1702 			&repinfo->client_addr, repinfo->client_addrlen);
1703 		regional_free_all(worker->scratchpad);
1704 		goto send_reply;
1705 	}
1706 	if(local_zones_answer(worker->daemon->local_zones, &worker->env, &qinfo,
1707 		&edns, c->buffer, worker->scratchpad, repinfo, acladdr->taglist,
1708 		acladdr->taglen, acladdr->tag_actions,
1709 		acladdr->tag_actions_size, acladdr->tag_datas,
1710 		acladdr->tag_datas_size, worker->daemon->cfg->tagname,
1711 		worker->daemon->cfg->num_tags, acladdr->view)) {
1712 		regional_free_all(worker->scratchpad);
1713 		if(sldns_buffer_limit(c->buffer) == 0) {
1714 			comm_point_drop_reply(repinfo);
1715 			return 0;
1716 		}
1717 		goto send_reply;
1718 	}
1719 	if(worker->env.auth_zones &&
1720 		rpz_callback_from_worker_request(worker->env.auth_zones,
1721 		&worker->env, &qinfo, &edns, c->buffer, worker->scratchpad,
1722 		repinfo, acladdr->taglist, acladdr->taglen, &worker->stats,
1723 		&rpz_passthru)) {
1724 		regional_free_all(worker->scratchpad);
1725 		if(sldns_buffer_limit(c->buffer) == 0) {
1726 			comm_point_drop_reply(repinfo);
1727 			return 0;
1728 		}
1729 		goto send_reply;
1730 	}
1731 	if(worker->env.auth_zones &&
1732 		auth_zones_answer(worker->env.auth_zones, &worker->env,
1733 		&qinfo, &edns, repinfo, c->buffer, worker->scratchpad)) {
1734 		regional_free_all(worker->scratchpad);
1735 		if(sldns_buffer_limit(c->buffer) == 0) {
1736 			comm_point_drop_reply(repinfo);
1737 			return 0;
1738 		}
1739 		/* set RA for everyone that can have recursion (based on
1740 		 * access control list) */
1741 		if(LDNS_RD_WIRE(sldns_buffer_begin(c->buffer)) &&
1742 		   acl != acl_deny_non_local && acl != acl_refuse_non_local)
1743 			LDNS_RA_SET(sldns_buffer_begin(c->buffer));
1744 		goto send_reply;
1745 	}
1746 
1747 	/* We've looked in our local zones. If the answer isn't there, we
1748 	 * might need to bail out based on ACLs now. */
1749 	if((ret=deny_refuse_non_local(c, acl, worker, repinfo, acladdr,
1750 		worker->env.cfg->ede, &check_result)) != -1)
1751 	{
1752 		regional_free_all(worker->scratchpad);
1753 		if(ret == 1)
1754 			goto send_reply;
1755 		return ret;
1756 	}
1757 
1758 	/* If this request does not have the recursion bit set, verify
1759 	 * ACLs allow the recursion bit to be treated as set. */
1760 	if(!(LDNS_RD_WIRE(sldns_buffer_begin(c->buffer))) &&
1761 		acl == acl_allow_setrd ) {
1762 		LDNS_RD_SET(sldns_buffer_begin(c->buffer));
1763 	}
1764 
1765 	/* If this request does not have the recursion bit set, verify
1766 	 * ACLs allow the snooping. */
1767 	if(!(LDNS_RD_WIRE(sldns_buffer_begin(c->buffer))) &&
1768 		acl != acl_allow_snoop ) {
1769 		if(worker->env.cfg->ede) {
1770 			EDNS_OPT_LIST_APPEND_EDE(&edns.opt_list_out,
1771 				worker->scratchpad, LDNS_EDE_NOT_AUTHORITATIVE, "");
1772 		}
1773 		error_encode(c->buffer, LDNS_RCODE_REFUSED, &qinfo,
1774 			*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
1775 			sldns_buffer_read_u16_at(c->buffer, 2), &edns);
1776 		regional_free_all(worker->scratchpad);
1777 		log_addr(VERB_ALGO, "refused nonrec (cache snoop) query from",
1778 			&repinfo->client_addr, repinfo->client_addrlen);
1779 
1780 		goto send_reply;
1781 	}
1782 
1783 	/* If we've found a local alias, replace the qname with the alias
1784 	 * target before resolving it. */
1785 	if(qinfo.local_alias) {
1786 		struct ub_packed_rrset_key* rrset = qinfo.local_alias->rrset;
1787 		struct packed_rrset_data* d = rrset->entry.data;
1788 
1789 		/* Sanity check: our current implementation only supports
1790 		 * a single CNAME RRset as a local alias. */
1791 		if(qinfo.local_alias->next ||
1792 			rrset->rk.type != htons(LDNS_RR_TYPE_CNAME) ||
1793 			d->count != 1) {
1794 			log_err("assumption failure: unexpected local alias");
1795 			regional_free_all(worker->scratchpad);
1796 			return 0; /* drop it */
1797 		}
1798 		qinfo.qname = d->rr_data[0] + 2;
1799 		qinfo.qname_len = d->rr_len[0] - 2;
1800 	}
1801 
1802 	/* If we may apply IP-based actions to the answer, build the client
1803 	 * information.  As this can be expensive, skip it if there is
1804 	 * absolutely no possibility of it. */
1805 	if((worker->daemon->use_response_ip || worker->daemon->use_rpz) &&
1806 		(qinfo.qtype == LDNS_RR_TYPE_A ||
1807 		qinfo.qtype == LDNS_RR_TYPE_AAAA ||
1808 		qinfo.qtype == LDNS_RR_TYPE_ANY)) {
1809 		cinfo_tmp.taglist = acladdr->taglist;
1810 		cinfo_tmp.taglen = acladdr->taglen;
1811 		cinfo_tmp.tag_actions = acladdr->tag_actions;
1812 		cinfo_tmp.tag_actions_size = acladdr->tag_actions_size;
1813 		cinfo_tmp.tag_datas = acladdr->tag_datas;
1814 		cinfo_tmp.tag_datas_size = acladdr->tag_datas_size;
1815 		cinfo_tmp.view = acladdr->view;
1816 		cinfo_tmp.respip_set = worker->daemon->respip_set;
1817 		cinfo = &cinfo_tmp;
1818 	}
1819 
1820 	/* Keep the original edns list around. The pointer could change if there is
1821 	 * a cached answer (through the inplace callback function there).
1822 	 * No need to actually copy the contents as they shouldn't change.
1823 	 * Used while prefetching and subnet is enabled. */
1824 	original_edns_list = edns.opt_list_in;
1825 lookup_cache:
1826 	/* Lookup the cache.  In case we chase an intermediate CNAME chain
1827 	 * this is a two-pass operation, and lookup_qinfo is different for
1828 	 * each pass.  We should still pass the original qinfo to
1829 	 * answer_from_cache(), however, since it's used to build the reply. */
1830 	if(!edns_bypass_cache_stage(edns.opt_list_in, &worker->env)) {
1831 		is_expired_answer = 0;
1832 		is_secure_answer = 0;
1833 		h = query_info_hash(lookup_qinfo, sldns_buffer_read_u16_at(c->buffer, 2));
1834 		if((e=slabhash_lookup(worker->env.msg_cache, h, lookup_qinfo, 0))) {
1835 			struct reply_info* rep = (struct reply_info*)e->data;
1836 			/* answer from cache - we have acquired a readlock on it */
1837 			if(answer_from_cache(worker, &qinfo, cinfo, &need_drop,
1838 				&is_expired_answer, &is_secure_answer,
1839 				&alias_rrset, &partial_rep, rep,
1840 				*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
1841 				sldns_buffer_read_u16_at(c->buffer, 2), repinfo,
1842 				&edns)) {
1843 				/* prefetch it if the prefetch TTL expired.
1844 				 * Note that if there is more than one pass
1845 				 * its qname must be that used for cache
1846 				 * lookup. */
1847 				if((worker->env.cfg->prefetch &&
1848 					*worker->env.now >= rep->prefetch_ttl) ||
1849 					(worker->env.cfg->serve_expired &&
1850 					*worker->env.now > rep->ttl)) {
1851 
1852 					time_t leeway = rep->ttl - *worker->env.now;
1853 					if(rep->ttl < *worker->env.now)
1854 						leeway = 0;
1855 					lock_rw_unlock(&e->lock);
1856 
1857 					reply_and_prefetch(worker, lookup_qinfo,
1858 						sldns_buffer_read_u16_at(c->buffer, 2),
1859 						repinfo, leeway,
1860 						(partial_rep || need_drop),
1861 						rpz_passthru,
1862 						original_edns_list);
1863 					if(!partial_rep) {
1864 						rc = 0;
1865 						regional_free_all(worker->scratchpad);
1866 						goto send_reply_rc;
1867 					}
1868 				} else if(!partial_rep) {
1869 					lock_rw_unlock(&e->lock);
1870 					regional_free_all(worker->scratchpad);
1871 					goto send_reply;
1872 				} else {
1873 					/* Note that we've already released the
1874 					 * lock if we're here after prefetch. */
1875 					lock_rw_unlock(&e->lock);
1876 				}
1877 				/* We've found a partial reply ending with an
1878 				 * alias.  Replace the lookup qinfo for the
1879 				 * alias target and lookup the cache again to
1880 				 * (possibly) complete the reply.  As we're
1881 				 * passing the "base" reply, there will be no
1882 				 * more alias chasing. */
1883 				memset(&qinfo_tmp, 0, sizeof(qinfo_tmp));
1884 				get_cname_target(alias_rrset, &qinfo_tmp.qname,
1885 					&qinfo_tmp.qname_len);
1886 				if(!qinfo_tmp.qname) {
1887 					log_err("unexpected: invalid answer alias");
1888 					regional_free_all(worker->scratchpad);
1889 					return 0; /* drop query */
1890 				}
1891 				qinfo_tmp.qtype = qinfo.qtype;
1892 				qinfo_tmp.qclass = qinfo.qclass;
1893 				lookup_qinfo = &qinfo_tmp;
1894 				goto lookup_cache;
1895 			}
1896 			verbose(VERB_ALGO, "answer from the cache failed");
1897 			lock_rw_unlock(&e->lock);
1898 		}
1899 
1900 		if(!LDNS_RD_WIRE(sldns_buffer_begin(c->buffer))) {
1901 			if(answer_norec_from_cache(worker, &qinfo,
1902 				*(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
1903 				sldns_buffer_read_u16_at(c->buffer, 2), repinfo,
1904 				&edns)) {
1905 				regional_free_all(worker->scratchpad);
1906 				goto send_reply;
1907 			}
1908 			verbose(VERB_ALGO, "answer norec from cache -- "
1909 				"need to validate or not primed");
1910 		}
1911 	}
1912 	sldns_buffer_rewind(c->buffer);
1913 	server_stats_querymiss(&worker->stats, worker);
1914 
1915 	if(verbosity >= VERB_CLIENT) {
1916 		if(c->type == comm_udp)
1917 			log_addr(VERB_CLIENT, "udp request from",
1918 				&repinfo->client_addr, repinfo->client_addrlen);
1919 		else	log_addr(VERB_CLIENT, "tcp request from",
1920 				&repinfo->client_addr, repinfo->client_addrlen);
1921 	}
1922 
1923 	/* grab a work request structure for this new request */
1924 	mesh_new_client(worker->env.mesh, &qinfo, cinfo,
1925 		sldns_buffer_read_u16_at(c->buffer, 2),
1926 		&edns, repinfo, *(uint16_t*)(void *)sldns_buffer_begin(c->buffer),
1927 		rpz_passthru);
1928 	regional_free_all(worker->scratchpad);
1929 	worker_mem_report(worker, NULL);
1930 	return 0;
1931 
1932 send_reply:
1933 	rc = 1;
1934 send_reply_rc:
1935 	if(need_drop) {
1936 		comm_point_drop_reply(repinfo);
1937 		return 0;
1938 	}
1939 	if(is_expired_answer) {
1940 		worker->stats.ans_expired++;
1941 	}
1942 	server_stats_insrcode(&worker->stats, c->buffer);
1943 	if(worker->stats.extended) {
1944 		if(is_secure_answer) worker->stats.ans_secure++;
1945 	}
1946 #ifdef USE_DNSTAP
1947 	/*
1948 	 * sending src (client)/dst (local service) addresses over DNSTAP from send_reply code label (when we serviced local zone for ex.)
1949 	 */
1950 	if(worker->dtenv.log_client_response_messages && rc !=0) {
1951 		log_addr(VERB_ALGO, "from local addr", (void*)repinfo->c->socket->addr, repinfo->c->socket->addrlen);
1952 		log_addr(VERB_ALGO, "response to client", &repinfo->client_addr, repinfo->client_addrlen);
1953 		dt_msg_send_client_response(&worker->dtenv, &repinfo->client_addr, (void*)repinfo->c->socket->addr, c->type, c->ssl, c->buffer);
1954 	}
1955 #endif
1956 	if(worker->env.cfg->log_replies)
1957 	{
1958 		struct timeval tv;
1959 		memset(&tv, 0, sizeof(tv));
1960 		if(qinfo.local_alias && qinfo.local_alias->rrset &&
1961 			qinfo.local_alias->rrset->rk.dname) {
1962 			/* log original qname, before the local alias was
1963 			 * used to resolve that CNAME to something else */
1964 			qinfo.qname = qinfo.local_alias->rrset->rk.dname;
1965 			log_reply_info(NO_VERBOSE, &qinfo,
1966 				&repinfo->client_addr, repinfo->client_addrlen,
1967 				tv, 1, c->buffer,
1968 				(worker->env.cfg->log_destaddr?(void*)repinfo->c->socket->addr:NULL),
1969 				c->type);
1970 		} else {
1971 			log_reply_info(NO_VERBOSE, &qinfo,
1972 				&repinfo->client_addr, repinfo->client_addrlen,
1973 				tv, 1, c->buffer,
1974 				(worker->env.cfg->log_destaddr?(void*)repinfo->c->socket->addr:NULL),
1975 				c->type);
1976 		}
1977 	}
1978 #ifdef USE_DNSCRYPT
1979 	if(!dnsc_handle_uncurved_request(repinfo)) {
1980 		return 0;
1981 	}
1982 #endif
1983 	return rc;
1984 }
1985 
1986 void
1987 worker_sighandler(int sig, void* arg)
1988 {
1989 	/* note that log, print, syscalls here give race conditions.
1990 	 * And cause hangups if the log-lock is held by the application. */
1991 	struct worker* worker = (struct worker*)arg;
1992 	switch(sig) {
1993 #ifdef SIGHUP
1994 		case SIGHUP:
1995 			comm_base_exit(worker->base);
1996 			break;
1997 #endif
1998 #ifdef SIGBREAK
1999 		case SIGBREAK:
2000 #endif
2001 		case SIGINT:
2002 			worker->need_to_exit = 1;
2003 			comm_base_exit(worker->base);
2004 			break;
2005 #ifdef SIGQUIT
2006 		case SIGQUIT:
2007 			worker->need_to_exit = 1;
2008 			comm_base_exit(worker->base);
2009 			break;
2010 #endif
2011 		case SIGTERM:
2012 			worker->need_to_exit = 1;
2013 			comm_base_exit(worker->base);
2014 			break;
2015 		default:
2016 			/* unknown signal, ignored */
2017 			break;
2018 	}
2019 }
2020 
2021 /** restart statistics timer for worker, if enabled */
2022 static void
2023 worker_restart_timer(struct worker* worker)
2024 {
2025 	if(worker->env.cfg->stat_interval > 0) {
2026 		struct timeval tv;
2027 #ifndef S_SPLINT_S
2028 		tv.tv_sec = worker->env.cfg->stat_interval;
2029 		tv.tv_usec = 0;
2030 #endif
2031 		comm_timer_set(worker->stat_timer, &tv);
2032 	}
2033 }
2034 
2035 void worker_stat_timer_cb(void* arg)
2036 {
2037 	struct worker* worker = (struct worker*)arg;
2038 	server_stats_log(&worker->stats, worker, worker->thread_num);
2039 	mesh_stats(worker->env.mesh, "mesh has");
2040 	worker_mem_report(worker, NULL);
2041 	/* SHM is enabled, process data to SHM */
2042 	if (worker->daemon->cfg->shm_enable) {
2043 		shm_main_run(worker);
2044 	}
2045 	if(!worker->daemon->cfg->stat_cumulative) {
2046 		worker_stats_clear(worker);
2047 	}
2048 	/* start next timer */
2049 	worker_restart_timer(worker);
2050 }
2051 
2052 void worker_probe_timer_cb(void* arg)
2053 {
2054 	struct worker* worker = (struct worker*)arg;
2055 	struct timeval tv;
2056 #ifndef S_SPLINT_S
2057 	tv.tv_sec = (time_t)autr_probe_timer(&worker->env);
2058 	tv.tv_usec = 0;
2059 #endif
2060 	if(tv.tv_sec != 0)
2061 		comm_timer_set(worker->env.probe_timer, &tv);
2062 }
2063 
2064 struct worker*
2065 worker_create(struct daemon* daemon, int id, int* ports, int n)
2066 {
2067 	unsigned int seed;
2068 	struct worker* worker = (struct worker*)calloc(1,
2069 		sizeof(struct worker));
2070 	if(!worker)
2071 		return NULL;
2072 	worker->numports = n;
2073 	worker->ports = (int*)memdup(ports, sizeof(int)*n);
2074 	if(!worker->ports) {
2075 		free(worker);
2076 		return NULL;
2077 	}
2078 	worker->daemon = daemon;
2079 	worker->thread_num = id;
2080 	if(!(worker->cmd = tube_create())) {
2081 		free(worker->ports);
2082 		free(worker);
2083 		return NULL;
2084 	}
2085 	/* create random state here to avoid locking trouble in RAND_bytes */
2086 	if(!(worker->rndstate = ub_initstate(daemon->rand))) {
2087 		log_err("could not init random numbers.");
2088 		tube_delete(worker->cmd);
2089 		free(worker->ports);
2090 		free(worker);
2091 		return NULL;
2092 	}
2093 	explicit_bzero(&seed, sizeof(seed));
2094 	return worker;
2095 }
2096 
2097 int
2098 worker_init(struct worker* worker, struct config_file *cfg,
2099 	struct listen_port* ports, int do_sigs)
2100 {
2101 #ifdef USE_DNSTAP
2102 	struct dt_env* dtenv = &worker->dtenv;
2103 #else
2104 	void* dtenv = NULL;
2105 #endif
2106 #ifdef HAVE_GETTID
2107 	worker->thread_tid = gettid();
2108 #endif
2109 	worker->need_to_exit = 0;
2110 	worker->base = comm_base_create(do_sigs);
2111 	if(!worker->base) {
2112 		log_err("could not create event handling base");
2113 		worker_delete(worker);
2114 		return 0;
2115 	}
2116 	comm_base_set_slow_accept_handlers(worker->base, &worker_stop_accept,
2117 		&worker_start_accept, worker);
2118 	if(do_sigs) {
2119 #ifdef SIGHUP
2120 		ub_thread_sig_unblock(SIGHUP);
2121 #endif
2122 #ifdef SIGBREAK
2123 		ub_thread_sig_unblock(SIGBREAK);
2124 #endif
2125 		ub_thread_sig_unblock(SIGINT);
2126 #ifdef SIGQUIT
2127 		ub_thread_sig_unblock(SIGQUIT);
2128 #endif
2129 		ub_thread_sig_unblock(SIGTERM);
2130 #ifndef LIBEVENT_SIGNAL_PROBLEM
2131 		worker->comsig = comm_signal_create(worker->base,
2132 			worker_sighandler, worker);
2133 		if(!worker->comsig
2134 #ifdef SIGHUP
2135 			|| !comm_signal_bind(worker->comsig, SIGHUP)
2136 #endif
2137 #ifdef SIGQUIT
2138 			|| !comm_signal_bind(worker->comsig, SIGQUIT)
2139 #endif
2140 			|| !comm_signal_bind(worker->comsig, SIGTERM)
2141 #ifdef SIGBREAK
2142 			|| !comm_signal_bind(worker->comsig, SIGBREAK)
2143 #endif
2144 			|| !comm_signal_bind(worker->comsig, SIGINT)) {
2145 			log_err("could not create signal handlers");
2146 			worker_delete(worker);
2147 			return 0;
2148 		}
2149 #endif /* LIBEVENT_SIGNAL_PROBLEM */
2150 		if(!daemon_remote_open_accept(worker->daemon->rc,
2151 			worker->daemon->rc_ports, worker)) {
2152 			worker_delete(worker);
2153 			return 0;
2154 		}
2155 #ifdef UB_ON_WINDOWS
2156 		wsvc_setup_worker(worker);
2157 #endif /* UB_ON_WINDOWS */
2158 	} else { /* !do_sigs */
2159 		worker->comsig = NULL;
2160 	}
2161 #ifdef USE_DNSTAP
2162 	if(cfg->dnstap) {
2163 		log_assert(worker->daemon->dtenv != NULL);
2164 		memcpy(&worker->dtenv, worker->daemon->dtenv, sizeof(struct dt_env));
2165 		if(!dt_init(&worker->dtenv, worker->base))
2166 			fatal_exit("dt_init failed");
2167 	}
2168 #endif
2169 	worker->front = listen_create(worker->base, ports,
2170 		cfg->msg_buffer_size, (int)cfg->incoming_num_tcp,
2171 		cfg->do_tcp_keepalive
2172 			? cfg->tcp_keepalive_timeout
2173 			: cfg->tcp_idle_timeout,
2174 		cfg->harden_large_queries, cfg->http_max_streams,
2175 		cfg->http_endpoint, cfg->http_notls_downstream,
2176 		worker->daemon->tcl, worker->daemon->listen_sslctx,
2177 		dtenv, worker->daemon->doq_table, worker->env.rnd,
2178 		cfg->ssl_service_key, cfg->ssl_service_pem, cfg,
2179 		worker_handle_request, worker);
2180 	if(!worker->front) {
2181 		log_err("could not create listening sockets");
2182 		worker_delete(worker);
2183 		return 0;
2184 	}
2185 	worker->back = outside_network_create(worker->base,
2186 		cfg->msg_buffer_size, (size_t)cfg->outgoing_num_ports,
2187 		cfg->out_ifs, cfg->num_out_ifs, cfg->do_ip4, cfg->do_ip6,
2188 		cfg->do_tcp?cfg->outgoing_num_tcp:0, cfg->ip_dscp,
2189 		worker->daemon->env->infra_cache, worker->rndstate,
2190 		cfg->use_caps_bits_for_id, worker->ports, worker->numports,
2191 		cfg->unwanted_threshold, cfg->outgoing_tcp_mss,
2192 		&worker_alloc_cleanup, worker,
2193 		cfg->do_udp || cfg->udp_upstream_without_downstream,
2194 		worker->daemon->connect_sslctx, cfg->delay_close,
2195 		cfg->tls_use_sni, dtenv, cfg->udp_connect,
2196 		cfg->max_reuse_tcp_queries, cfg->tcp_reuse_timeout,
2197 		cfg->tcp_auth_query_timeout);
2198 	if(!worker->back) {
2199 		log_err("could not create outgoing sockets");
2200 		worker_delete(worker);
2201 		return 0;
2202 	}
2203 	iterator_set_ip46_support(&worker->daemon->mods, worker->daemon->env,
2204 		worker->back);
2205 	/* start listening to commands */
2206 	if(!tube_setup_bg_listen(worker->cmd, worker->base,
2207 		&worker_handle_control_cmd, worker)) {
2208 		log_err("could not create control compt.");
2209 		worker_delete(worker);
2210 		return 0;
2211 	}
2212 	worker->stat_timer = comm_timer_create(worker->base,
2213 		worker_stat_timer_cb, worker);
2214 	if(!worker->stat_timer) {
2215 		log_err("could not create statistics timer");
2216 	}
2217 
2218 	/* we use the msg_buffer_size as a good estimate for what the
2219 	 * user wants for memory usage sizes */
2220 	worker->scratchpad = regional_create_custom(cfg->msg_buffer_size);
2221 	if(!worker->scratchpad) {
2222 		log_err("malloc failure");
2223 		worker_delete(worker);
2224 		return 0;
2225 	}
2226 
2227 	server_stats_init(&worker->stats, cfg);
2228 	worker->alloc = worker->daemon->worker_allocs[worker->thread_num];
2229 	alloc_set_id_cleanup(worker->alloc, &worker_alloc_cleanup, worker);
2230 	worker->env = *worker->daemon->env;
2231 	comm_base_timept(worker->base, &worker->env.now, &worker->env.now_tv);
2232 	worker->env.worker = worker;
2233 	worker->env.worker_base = worker->base;
2234 	worker->env.send_query = &worker_send_query;
2235 	worker->env.alloc = worker->alloc;
2236 	worker->env.outnet = worker->back;
2237 	worker->env.rnd = worker->rndstate;
2238 	/* If case prefetch is triggered, the corresponding mesh will clear
2239 	 * the scratchpad for the module env in the middle of request handling.
2240 	 * It would be prone to a use-after-free kind of bug, so we avoid
2241 	 * sharing it with worker's own scratchpad at the cost of having
2242 	 * one more pad per worker. */
2243 	worker->env.scratch = regional_create_custom(cfg->msg_buffer_size);
2244 	if(!worker->env.scratch) {
2245 		log_err("malloc failure");
2246 		worker_delete(worker);
2247 		return 0;
2248 	}
2249 	worker->env.mesh = mesh_create(&worker->daemon->mods, &worker->env);
2250 	if(!worker->env.mesh) {
2251 		log_err("malloc failure");
2252 		worker_delete(worker);
2253 		return 0;
2254 	}
2255 	/* Pass on daemon variables that we would need in the mesh area */
2256 	worker->env.mesh->use_response_ip = worker->daemon->use_response_ip;
2257 	worker->env.mesh->use_rpz = worker->daemon->use_rpz;
2258 
2259 	worker->env.detach_subs = &mesh_detach_subs;
2260 	worker->env.attach_sub = &mesh_attach_sub;
2261 	worker->env.add_sub = &mesh_add_sub;
2262 	worker->env.kill_sub = &mesh_state_delete;
2263 	worker->env.detect_cycle = &mesh_detect_cycle;
2264 	worker->env.scratch_buffer = sldns_buffer_new(cfg->msg_buffer_size);
2265 	if(!worker->env.scratch_buffer) {
2266 		log_err("malloc failure");
2267 		worker_delete(worker);
2268 		return 0;
2269 	}
2270 	/* one probe timer per process -- if we have 5011 anchors */
2271 	if(autr_get_num_anchors(worker->env.anchors) > 0
2272 #ifndef THREADS_DISABLED
2273 		&& worker->thread_num == 0
2274 #endif
2275 		) {
2276 		struct timeval tv;
2277 		tv.tv_sec = 0;
2278 		tv.tv_usec = 0;
2279 		worker->env.probe_timer = comm_timer_create(worker->base,
2280 			worker_probe_timer_cb, worker);
2281 		if(!worker->env.probe_timer) {
2282 			log_err("could not create 5011-probe timer");
2283 		} else {
2284 			/* let timer fire, then it can reset itself */
2285 			comm_timer_set(worker->env.probe_timer, &tv);
2286 		}
2287 	}
2288 	/* zone transfer tasks, setup once per process, if any */
2289 	if(worker->env.auth_zones
2290 #ifndef THREADS_DISABLED
2291 		&& worker->thread_num == 0
2292 #endif
2293 		) {
2294 		auth_xfer_pickup_initial(worker->env.auth_zones, &worker->env);
2295 		auth_zones_pickup_zonemd_verify(worker->env.auth_zones,
2296 			&worker->env);
2297 	}
2298 #ifdef USE_DNSTAP
2299 	if(worker->daemon->cfg->dnstap
2300 #ifndef THREADS_DISABLED
2301 		&& worker->thread_num == 0
2302 #endif
2303 		) {
2304 		if(!dt_io_thread_start(dtenv->dtio, comm_base_internal(
2305 			worker->base), worker->daemon->num)) {
2306 			log_err("could not start dnstap io thread");
2307 			worker_delete(worker);
2308 			return 0;
2309 		}
2310 	}
2311 #endif /* USE_DNSTAP */
2312 	worker_mem_report(worker, NULL);
2313 	/* if statistics enabled start timer */
2314 	if(worker->env.cfg->stat_interval > 0) {
2315 		verbose(VERB_ALGO, "set statistics interval %d secs",
2316 			worker->env.cfg->stat_interval);
2317 		worker_restart_timer(worker);
2318 	}
2319 	pp_init(&sldns_write_uint16, &sldns_write_uint32);
2320 	return 1;
2321 }
2322 
2323 void
2324 worker_work(struct worker* worker)
2325 {
2326 	comm_base_dispatch(worker->base);
2327 }
2328 
2329 void
2330 worker_delete(struct worker* worker)
2331 {
2332 	if(!worker)
2333 		return;
2334 	if(worker->env.mesh && verbosity >= VERB_OPS) {
2335 		server_stats_log(&worker->stats, worker, worker->thread_num);
2336 		mesh_stats(worker->env.mesh, "mesh has");
2337 		worker_mem_report(worker, NULL);
2338 	}
2339 	outside_network_quit_prepare(worker->back);
2340 	mesh_delete(worker->env.mesh);
2341 	sldns_buffer_free(worker->env.scratch_buffer);
2342 	listen_delete(worker->front);
2343 	outside_network_delete(worker->back);
2344 	comm_signal_delete(worker->comsig);
2345 	tube_delete(worker->cmd);
2346 	comm_timer_delete(worker->stat_timer);
2347 	comm_timer_delete(worker->env.probe_timer);
2348 	free(worker->ports);
2349 	if(worker->thread_num == 0) {
2350 #ifdef UB_ON_WINDOWS
2351 		wsvc_desetup_worker(worker);
2352 #endif /* UB_ON_WINDOWS */
2353 	}
2354 #ifdef USE_DNSTAP
2355 	if(worker->daemon->cfg->dnstap
2356 #ifndef THREADS_DISABLED
2357 		&& worker->thread_num == 0
2358 #endif
2359 		) {
2360 		dt_io_thread_stop(worker->dtenv.dtio);
2361 	}
2362 	dt_deinit(&worker->dtenv);
2363 #endif /* USE_DNSTAP */
2364 	comm_base_delete(worker->base);
2365 	ub_randfree(worker->rndstate);
2366 	/* don't touch worker->alloc, as it's maintained in daemon */
2367 	regional_destroy(worker->env.scratch);
2368 	regional_destroy(worker->scratchpad);
2369 	free(worker);
2370 }
2371 
2372 struct outbound_entry*
2373 worker_send_query(struct query_info* qinfo, uint16_t flags, int dnssec,
2374 	int want_dnssec, int nocaps, int check_ratelimit,
2375 	struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* zone,
2376 	size_t zonelen, int tcp_upstream, int ssl_upstream, char* tls_auth_name,
2377 	struct module_qstate* q, int* was_ratelimited)
2378 {
2379 	struct worker* worker = q->env->worker;
2380 	struct outbound_entry* e = (struct outbound_entry*)regional_alloc(
2381 		q->region, sizeof(*e));
2382 	if(!e)
2383 		return NULL;
2384 	e->qstate = q;
2385 	e->qsent = outnet_serviced_query(worker->back, qinfo, flags, dnssec,
2386 		want_dnssec, nocaps, check_ratelimit, tcp_upstream,
2387 		ssl_upstream, tls_auth_name, addr, addrlen, zone, zonelen, q,
2388 		worker_handle_service_reply, e, worker->back->udp_buff, q->env,
2389 		was_ratelimited);
2390 	if(!e->qsent) {
2391 		return NULL;
2392 	}
2393 	return e;
2394 }
2395 
2396 void
2397 worker_alloc_cleanup(void* arg)
2398 {
2399 	struct worker* worker = (struct worker*)arg;
2400 	slabhash_clear(&worker->env.rrset_cache->table);
2401 	slabhash_clear(worker->env.msg_cache);
2402 }
2403 
2404 void worker_stats_clear(struct worker* worker)
2405 {
2406 	server_stats_init(&worker->stats, worker->env.cfg);
2407 	mesh_stats_clear(worker->env.mesh);
2408 	worker->back->unwanted_replies = 0;
2409 	worker->back->num_tcp_outgoing = 0;
2410 	worker->back->num_udp_outgoing = 0;
2411 }
2412 
2413 void worker_start_accept(void* arg)
2414 {
2415 	struct worker* worker = (struct worker*)arg;
2416 	listen_start_accept(worker->front);
2417 	if(worker->thread_num == 0)
2418 		daemon_remote_start_accept(worker->daemon->rc);
2419 }
2420 
2421 void worker_stop_accept(void* arg)
2422 {
2423 	struct worker* worker = (struct worker*)arg;
2424 	listen_stop_accept(worker->front);
2425 	if(worker->thread_num == 0)
2426 		daemon_remote_stop_accept(worker->daemon->rc);
2427 }
2428 
2429 /* --- fake callbacks for fptr_wlist to work --- */
2430 struct outbound_entry* libworker_send_query(
2431 	struct query_info* ATTR_UNUSED(qinfo),
2432 	uint16_t ATTR_UNUSED(flags), int ATTR_UNUSED(dnssec),
2433 	int ATTR_UNUSED(want_dnssec), int ATTR_UNUSED(nocaps),
2434 	int ATTR_UNUSED(check_ratelimit),
2435 	struct sockaddr_storage* ATTR_UNUSED(addr), socklen_t ATTR_UNUSED(addrlen),
2436 	uint8_t* ATTR_UNUSED(zone), size_t ATTR_UNUSED(zonelen), int ATTR_UNUSED(tcp_upstream),
2437 	int ATTR_UNUSED(ssl_upstream), char* ATTR_UNUSED(tls_auth_name),
2438 	struct module_qstate* ATTR_UNUSED(q), int* ATTR_UNUSED(was_ratelimited))
2439 {
2440 	log_assert(0);
2441 	return 0;
2442 }
2443 
2444 int libworker_handle_service_reply(struct comm_point* ATTR_UNUSED(c),
2445 	void* ATTR_UNUSED(arg), int ATTR_UNUSED(error),
2446         struct comm_reply* ATTR_UNUSED(reply_info))
2447 {
2448 	log_assert(0);
2449 	return 0;
2450 }
2451 
2452 void libworker_handle_control_cmd(struct tube* ATTR_UNUSED(tube),
2453         uint8_t* ATTR_UNUSED(buffer), size_t ATTR_UNUSED(len),
2454         int ATTR_UNUSED(error), void* ATTR_UNUSED(arg))
2455 {
2456 	log_assert(0);
2457 }
2458 
2459 void libworker_fg_done_cb(void* ATTR_UNUSED(arg), int ATTR_UNUSED(rcode),
2460 	sldns_buffer* ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s),
2461 	char* ATTR_UNUSED(why_bogus), int ATTR_UNUSED(was_ratelimited))
2462 {
2463 	log_assert(0);
2464 }
2465 
2466 void libworker_bg_done_cb(void* ATTR_UNUSED(arg), int ATTR_UNUSED(rcode),
2467 	sldns_buffer* ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s),
2468 	char* ATTR_UNUSED(why_bogus), int ATTR_UNUSED(was_ratelimited))
2469 {
2470 	log_assert(0);
2471 }
2472 
2473 void libworker_event_done_cb(void* ATTR_UNUSED(arg), int ATTR_UNUSED(rcode),
2474 	sldns_buffer* ATTR_UNUSED(buf), enum sec_status ATTR_UNUSED(s),
2475 	char* ATTR_UNUSED(why_bogus), int ATTR_UNUSED(was_ratelimited))
2476 {
2477 	log_assert(0);
2478 }
2479 
2480 int context_query_cmp(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
2481 {
2482 	log_assert(0);
2483 	return 0;
2484 }
2485 
2486 int order_lock_cmp(const void* ATTR_UNUSED(e1), const void* ATTR_UNUSED(e2))
2487 {
2488 	log_assert(0);
2489 	return 0;
2490 }
2491 
2492 int codeline_cmp(const void* ATTR_UNUSED(a), const void* ATTR_UNUSED(b))
2493 {
2494 	log_assert(0);
2495 	return 0;
2496 }
2497 
2498 #ifdef USE_DNSTAP
2499 void dtio_tap_callback(int ATTR_UNUSED(fd), short ATTR_UNUSED(ev),
2500 	void* ATTR_UNUSED(arg))
2501 {
2502 	log_assert(0);
2503 }
2504 #endif
2505 
2506 #ifdef USE_DNSTAP
2507 void dtio_mainfdcallback(int ATTR_UNUSED(fd), short ATTR_UNUSED(ev),
2508 	void* ATTR_UNUSED(arg))
2509 {
2510 	log_assert(0);
2511 }
2512 #endif
2513 
2514 #ifdef HAVE_NGTCP2
2515 void doq_client_event_cb(int ATTR_UNUSED(fd), short ATTR_UNUSED(ev),
2516 	void* ATTR_UNUSED(arg))
2517 {
2518 	log_assert(0);
2519 }
2520 #endif
2521 
2522 #ifdef HAVE_NGTCP2
2523 void doq_client_timer_cb(int ATTR_UNUSED(fd), short ATTR_UNUSED(ev),
2524 	void* ATTR_UNUSED(arg))
2525 {
2526 	log_assert(0);
2527 }
2528 #endif
2529