xref: /freebsd/contrib/unbound/libunbound/libunbound.c (revision 68d75eff68281c1b445e3010bb975eae07aac225)
1 /*
2  * unbound.c - unbound validating resolver public API implementation
3  *
4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * This file contains functions to resolve DNS queries and
40  * validate the answers. Synchronously and asynchronously.
41  *
42  */
43 
44 /* include the public api first, it should be able to stand alone */
45 #include "libunbound/unbound.h"
46 #include "libunbound/unbound-event.h"
47 #include "config.h"
48 #include <ctype.h>
49 #include "libunbound/context.h"
50 #include "libunbound/libworker.h"
51 #include "util/locks.h"
52 #include "util/config_file.h"
53 #include "util/alloc.h"
54 #include "util/module.h"
55 #include "util/regional.h"
56 #include "util/log.h"
57 #include "util/random.h"
58 #include "util/net_help.h"
59 #include "util/tube.h"
60 #include "util/ub_event.h"
61 #include "services/modstack.h"
62 #include "services/localzone.h"
63 #include "services/cache/infra.h"
64 #include "services/cache/rrset.h"
65 #include "services/authzone.h"
66 #include "sldns/sbuffer.h"
67 #ifdef HAVE_PTHREAD
68 #include <signal.h>
69 #endif
70 #ifdef HAVE_SYS_WAIT_H
71 #include <sys/wait.h>
72 #endif
73 #ifdef HAVE_TIME_H
74 #include <time.h>
75 #endif
76 
77 #if defined(UB_ON_WINDOWS) && defined (HAVE_WINDOWS_H)
78 #include <windows.h>
79 #include <iphlpapi.h>
80 #endif /* UB_ON_WINDOWS */
81 
82 /** store that the logfile has a debug override */
83 int ctx_logfile_overridden = 0;
84 
85 /** create context functionality, but no pipes */
86 static struct ub_ctx* ub_ctx_create_nopipe(void)
87 {
88 	struct ub_ctx* ctx;
89 #ifdef USE_WINSOCK
90 	int r;
91 	WSADATA wsa_data;
92 #endif
93 
94 	checklock_start();
95 	if(!ctx_logfile_overridden)
96 		log_init(NULL, 0, NULL); /* logs to stderr */
97 	log_ident_set("libunbound");
98 #ifdef USE_WINSOCK
99 	if((r = WSAStartup(MAKEWORD(2,2), &wsa_data)) != 0) {
100 		log_err("could not init winsock. WSAStartup: %s",
101 			wsa_strerror(r));
102 		return NULL;
103 	}
104 #endif
105 	verbosity = NO_VERBOSE; /* errors only */
106 	checklock_start();
107 	ctx = (struct ub_ctx*)calloc(1, sizeof(*ctx));
108 	if(!ctx) {
109 		errno = ENOMEM;
110 		return NULL;
111 	}
112 	alloc_init(&ctx->superalloc, NULL, 0);
113 	if(!(ctx->seed_rnd = ub_initstate(NULL))) {
114 		ub_randfree(ctx->seed_rnd);
115 		free(ctx);
116 		errno = ENOMEM;
117 		return NULL;
118 	}
119 	lock_basic_init(&ctx->qqpipe_lock);
120 	lock_basic_init(&ctx->rrpipe_lock);
121 	lock_basic_init(&ctx->cfglock);
122 	ctx->env = (struct module_env*)calloc(1, sizeof(*ctx->env));
123 	if(!ctx->env) {
124 		ub_randfree(ctx->seed_rnd);
125 		free(ctx);
126 		errno = ENOMEM;
127 		return NULL;
128 	}
129 	ctx->env->cfg = config_create_forlib();
130 	if(!ctx->env->cfg) {
131 		free(ctx->env);
132 		ub_randfree(ctx->seed_rnd);
133 		free(ctx);
134 		errno = ENOMEM;
135 		return NULL;
136 	}
137 	/* init edns_known_options */
138 	if(!edns_known_options_init(ctx->env)) {
139 		config_delete(ctx->env->cfg);
140 		free(ctx->env);
141 		ub_randfree(ctx->seed_rnd);
142 		free(ctx);
143 		errno = ENOMEM;
144 		return NULL;
145 	}
146 	ctx->env->auth_zones = auth_zones_create();
147 	if(!ctx->env->auth_zones) {
148 		edns_known_options_delete(ctx->env);
149 		config_delete(ctx->env->cfg);
150 		free(ctx->env);
151 		ub_randfree(ctx->seed_rnd);
152 		free(ctx);
153 		errno = ENOMEM;
154 		return NULL;
155 	}
156 	ctx->env->alloc = &ctx->superalloc;
157 	ctx->env->worker = NULL;
158 	ctx->env->need_to_validate = 0;
159 	modstack_init(&ctx->mods);
160 	rbtree_init(&ctx->queries, &context_query_cmp);
161 	return ctx;
162 }
163 
164 struct ub_ctx*
165 ub_ctx_create(void)
166 {
167 	struct ub_ctx* ctx = ub_ctx_create_nopipe();
168 	if(!ctx)
169 		return NULL;
170 	if((ctx->qq_pipe = tube_create()) == NULL) {
171 		int e = errno;
172 		ub_randfree(ctx->seed_rnd);
173 		config_delete(ctx->env->cfg);
174 		modstack_desetup(&ctx->mods, ctx->env);
175 		edns_known_options_delete(ctx->env);
176 		free(ctx->env);
177 		free(ctx);
178 		errno = e;
179 		return NULL;
180 	}
181 	if((ctx->rr_pipe = tube_create()) == NULL) {
182 		int e = errno;
183 		tube_delete(ctx->qq_pipe);
184 		ub_randfree(ctx->seed_rnd);
185 		config_delete(ctx->env->cfg);
186 		modstack_desetup(&ctx->mods, ctx->env);
187 		edns_known_options_delete(ctx->env);
188 		free(ctx->env);
189 		free(ctx);
190 		errno = e;
191 		return NULL;
192 	}
193 	return ctx;
194 }
195 
196 struct ub_ctx*
197 ub_ctx_create_ub_event(struct ub_event_base* ueb)
198 {
199 	struct ub_ctx* ctx = ub_ctx_create_nopipe();
200 	if(!ctx)
201 		return NULL;
202 	/* no pipes, but we have the locks to make sure everything works */
203 	ctx->created_bg = 0;
204 	ctx->dothread = 1; /* the processing is in the same process,
205 		makes ub_cancel and ub_ctx_delete do the right thing */
206 	ctx->event_base = ueb;
207 	return ctx;
208 }
209 
210 struct ub_ctx*
211 ub_ctx_create_event(struct event_base* eb)
212 {
213 	struct ub_ctx* ctx = ub_ctx_create_nopipe();
214 	if(!ctx)
215 		return NULL;
216 	/* no pipes, but we have the locks to make sure everything works */
217 	ctx->created_bg = 0;
218 	ctx->dothread = 1; /* the processing is in the same process,
219 		makes ub_cancel and ub_ctx_delete do the right thing */
220 	ctx->event_base = ub_libevent_event_base(eb);
221 	if (!ctx->event_base) {
222 		ub_ctx_delete(ctx);
223 		return NULL;
224 	}
225 	ctx->event_base_malloced = 1;
226 	return ctx;
227 }
228 
229 /** delete q */
230 static void
231 delq(rbnode_type* n, void* ATTR_UNUSED(arg))
232 {
233 	struct ctx_query* q = (struct ctx_query*)n;
234 	context_query_delete(q);
235 }
236 
237 /** stop the bg thread */
238 static void ub_stop_bg(struct ub_ctx* ctx)
239 {
240 	/* stop the bg thread */
241 	lock_basic_lock(&ctx->cfglock);
242 	if(ctx->created_bg) {
243 		uint8_t* msg;
244 		uint32_t len;
245 		uint32_t cmd = UB_LIBCMD_QUIT;
246 		lock_basic_unlock(&ctx->cfglock);
247 		lock_basic_lock(&ctx->qqpipe_lock);
248 		(void)tube_write_msg(ctx->qq_pipe, (uint8_t*)&cmd,
249 			(uint32_t)sizeof(cmd), 0);
250 		lock_basic_unlock(&ctx->qqpipe_lock);
251 		lock_basic_lock(&ctx->rrpipe_lock);
252 		while(tube_read_msg(ctx->rr_pipe, &msg, &len, 0)) {
253 			/* discard all results except a quit confirm */
254 			if(context_serial_getcmd(msg, len) == UB_LIBCMD_QUIT) {
255 				free(msg);
256 				break;
257 			}
258 			free(msg);
259 		}
260 		lock_basic_unlock(&ctx->rrpipe_lock);
261 
262 		/* if bg worker is a thread, wait for it to exit, so that all
263 	 	 * resources are really gone. */
264 		lock_basic_lock(&ctx->cfglock);
265 		if(ctx->dothread) {
266 			lock_basic_unlock(&ctx->cfglock);
267 			ub_thread_join(ctx->bg_tid);
268 		} else {
269 			lock_basic_unlock(&ctx->cfglock);
270 #ifndef UB_ON_WINDOWS
271 			if(waitpid(ctx->bg_pid, NULL, 0) == -1) {
272 				if(verbosity > 2)
273 					log_err("waitpid: %s", strerror(errno));
274 			}
275 #endif
276 		}
277 	}
278 	else {
279 		lock_basic_unlock(&ctx->cfglock);
280 	}
281 }
282 
283 void
284 ub_ctx_delete(struct ub_ctx* ctx)
285 {
286 	struct alloc_cache* a, *na;
287 	int do_stop = 1;
288 	if(!ctx) return;
289 
290 	/* see if bg thread is created and if threads have been killed */
291 	/* no locks, because those may be held by terminated threads */
292 	/* for processes the read pipe is closed and we see that on read */
293 #ifdef HAVE_PTHREAD
294 	if(ctx->created_bg && ctx->dothread) {
295 		if(pthread_kill(ctx->bg_tid, 0) == ESRCH) {
296 			/* thread has been killed */
297 			do_stop = 0;
298 		}
299 	}
300 #endif /* HAVE_PTHREAD */
301 	if(do_stop)
302 		ub_stop_bg(ctx);
303 	libworker_delete_event(ctx->event_worker);
304 
305 	modstack_desetup(&ctx->mods, ctx->env);
306 	a = ctx->alloc_list;
307 	while(a) {
308 		na = a->super;
309 		a->super = &ctx->superalloc;
310 		alloc_clear(a);
311 		free(a);
312 		a = na;
313 	}
314 	local_zones_delete(ctx->local_zones);
315 	lock_basic_destroy(&ctx->qqpipe_lock);
316 	lock_basic_destroy(&ctx->rrpipe_lock);
317 	lock_basic_destroy(&ctx->cfglock);
318 	tube_delete(ctx->qq_pipe);
319 	tube_delete(ctx->rr_pipe);
320 	if(ctx->env) {
321 		slabhash_delete(ctx->env->msg_cache);
322 		rrset_cache_delete(ctx->env->rrset_cache);
323 		infra_delete(ctx->env->infra_cache);
324 		config_delete(ctx->env->cfg);
325 		edns_known_options_delete(ctx->env);
326 		auth_zones_delete(ctx->env->auth_zones);
327 		free(ctx->env);
328 	}
329 	ub_randfree(ctx->seed_rnd);
330 	alloc_clear(&ctx->superalloc);
331 	traverse_postorder(&ctx->queries, delq, NULL);
332 	if(ctx_logfile_overridden) {
333 		log_file(NULL);
334 		ctx_logfile_overridden = 0;
335 	}
336 	if(ctx->event_base_malloced)
337 		free(ctx->event_base);
338 	free(ctx);
339 #ifdef USE_WINSOCK
340 	WSACleanup();
341 #endif
342 }
343 
344 int
345 ub_ctx_set_option(struct ub_ctx* ctx, const char* opt, const char* val)
346 {
347 	lock_basic_lock(&ctx->cfglock);
348 	if(ctx->finalized) {
349 		lock_basic_unlock(&ctx->cfglock);
350 		return UB_AFTERFINAL;
351 	}
352 	if(!config_set_option(ctx->env->cfg, opt, val)) {
353 		lock_basic_unlock(&ctx->cfglock);
354 		return UB_SYNTAX;
355 	}
356 	lock_basic_unlock(&ctx->cfglock);
357 	return UB_NOERROR;
358 }
359 
360 int
361 ub_ctx_get_option(struct ub_ctx* ctx, const char* opt, char** str)
362 {
363 	int r;
364 	lock_basic_lock(&ctx->cfglock);
365 	r = config_get_option_collate(ctx->env->cfg, opt, str);
366 	lock_basic_unlock(&ctx->cfglock);
367 	if(r == 0) r = UB_NOERROR;
368 	else if(r == 1) r = UB_SYNTAX;
369 	else if(r == 2) r = UB_NOMEM;
370 	return r;
371 }
372 
373 int
374 ub_ctx_config(struct ub_ctx* ctx, const char* fname)
375 {
376 	lock_basic_lock(&ctx->cfglock);
377 	if(ctx->finalized) {
378 		lock_basic_unlock(&ctx->cfglock);
379 		return UB_AFTERFINAL;
380 	}
381 	if(!config_read(ctx->env->cfg, fname, NULL)) {
382 		lock_basic_unlock(&ctx->cfglock);
383 		return UB_SYNTAX;
384 	}
385 	lock_basic_unlock(&ctx->cfglock);
386 	return UB_NOERROR;
387 }
388 
389 int
390 ub_ctx_add_ta(struct ub_ctx* ctx, const char* ta)
391 {
392 	char* dup = strdup(ta);
393 	if(!dup) return UB_NOMEM;
394 	lock_basic_lock(&ctx->cfglock);
395 	if(ctx->finalized) {
396 		lock_basic_unlock(&ctx->cfglock);
397 		free(dup);
398 		return UB_AFTERFINAL;
399 	}
400 	if(!cfg_strlist_insert(&ctx->env->cfg->trust_anchor_list, dup)) {
401 		lock_basic_unlock(&ctx->cfglock);
402 		return UB_NOMEM;
403 	}
404 	lock_basic_unlock(&ctx->cfglock);
405 	return UB_NOERROR;
406 }
407 
408 int
409 ub_ctx_add_ta_file(struct ub_ctx* ctx, const char* fname)
410 {
411 	char* dup = strdup(fname);
412 	if(!dup) return UB_NOMEM;
413 	lock_basic_lock(&ctx->cfglock);
414 	if(ctx->finalized) {
415 		lock_basic_unlock(&ctx->cfglock);
416 		free(dup);
417 		return UB_AFTERFINAL;
418 	}
419 	if(!cfg_strlist_insert(&ctx->env->cfg->trust_anchor_file_list, dup)) {
420 		lock_basic_unlock(&ctx->cfglock);
421 		return UB_NOMEM;
422 	}
423 	lock_basic_unlock(&ctx->cfglock);
424 	return UB_NOERROR;
425 }
426 
427 int ub_ctx_add_ta_autr(struct ub_ctx* ctx, const char* fname)
428 {
429 	char* dup = strdup(fname);
430 	if(!dup) return UB_NOMEM;
431 	lock_basic_lock(&ctx->cfglock);
432 	if(ctx->finalized) {
433 		lock_basic_unlock(&ctx->cfglock);
434 		free(dup);
435 		return UB_AFTERFINAL;
436 	}
437 	if(!cfg_strlist_insert(&ctx->env->cfg->auto_trust_anchor_file_list,
438 		dup)) {
439 		lock_basic_unlock(&ctx->cfglock);
440 		return UB_NOMEM;
441 	}
442 	lock_basic_unlock(&ctx->cfglock);
443 	return UB_NOERROR;
444 }
445 
446 int
447 ub_ctx_trustedkeys(struct ub_ctx* ctx, const char* fname)
448 {
449 	char* dup = strdup(fname);
450 	if(!dup) return UB_NOMEM;
451 	lock_basic_lock(&ctx->cfglock);
452 	if(ctx->finalized) {
453 		lock_basic_unlock(&ctx->cfglock);
454 		free(dup);
455 		return UB_AFTERFINAL;
456 	}
457 	if(!cfg_strlist_insert(&ctx->env->cfg->trusted_keys_file_list, dup)) {
458 		lock_basic_unlock(&ctx->cfglock);
459 		return UB_NOMEM;
460 	}
461 	lock_basic_unlock(&ctx->cfglock);
462 	return UB_NOERROR;
463 }
464 
465 int
466 ub_ctx_debuglevel(struct ub_ctx* ctx, int d)
467 {
468 	lock_basic_lock(&ctx->cfglock);
469 	verbosity = d;
470 	ctx->env->cfg->verbosity = d;
471 	lock_basic_unlock(&ctx->cfglock);
472 	return UB_NOERROR;
473 }
474 
475 int ub_ctx_debugout(struct ub_ctx* ctx, void* out)
476 {
477 	lock_basic_lock(&ctx->cfglock);
478 	log_file((FILE*)out);
479 	ctx_logfile_overridden = 1;
480 	ctx->logfile_override = 1;
481 	ctx->log_out = out;
482 	lock_basic_unlock(&ctx->cfglock);
483 	return UB_NOERROR;
484 }
485 
486 int
487 ub_ctx_async(struct ub_ctx* ctx, int dothread)
488 {
489 #ifdef THREADS_DISABLED
490 	if(dothread) /* cannot do threading */
491 		return UB_NOERROR;
492 #endif
493 	lock_basic_lock(&ctx->cfglock);
494 	if(ctx->finalized) {
495 		lock_basic_unlock(&ctx->cfglock);
496 		return UB_AFTERFINAL;
497 	}
498 	ctx->dothread = dothread;
499 	lock_basic_unlock(&ctx->cfglock);
500 	return UB_NOERROR;
501 }
502 
503 int
504 ub_poll(struct ub_ctx* ctx)
505 {
506 	/* no need to hold lock while testing for readability. */
507 	return tube_poll(ctx->rr_pipe);
508 }
509 
510 int
511 ub_fd(struct ub_ctx* ctx)
512 {
513 	return tube_read_fd(ctx->rr_pipe);
514 }
515 
516 /** process answer from bg worker */
517 static int
518 process_answer_detail(struct ub_ctx* ctx, uint8_t* msg, uint32_t len,
519 	ub_callback_type* cb, void** cbarg, int* err,
520 	struct ub_result** res)
521 {
522 	struct ctx_query* q;
523 	if(context_serial_getcmd(msg, len) != UB_LIBCMD_ANSWER) {
524 		log_err("error: bad data from bg worker %d",
525 			(int)context_serial_getcmd(msg, len));
526 		return 0;
527 	}
528 
529 	lock_basic_lock(&ctx->cfglock);
530 	q = context_deserialize_answer(ctx, msg, len, err);
531 	if(!q) {
532 		lock_basic_unlock(&ctx->cfglock);
533 		/* probably simply the lookup that failed, i.e.
534 		 * response returned before cancel was sent out, so noerror */
535 		return 1;
536 	}
537 	log_assert(q->async);
538 
539 	/* grab cb while locked */
540 	if(q->cancelled) {
541 		*cb = NULL;
542 		*cbarg = NULL;
543 	} else {
544 		*cb = q->cb;
545 		*cbarg = q->cb_arg;
546 	}
547 	if(*err) {
548 		*res = NULL;
549 		ub_resolve_free(q->res);
550 	} else {
551 		/* parse the message, extract rcode, fill result */
552 		sldns_buffer* buf = sldns_buffer_new(q->msg_len);
553 		struct regional* region = regional_create();
554 		*res = q->res;
555 		(*res)->rcode = LDNS_RCODE_SERVFAIL;
556 		if(region && buf) {
557 			sldns_buffer_clear(buf);
558 			sldns_buffer_write(buf, q->msg, q->msg_len);
559 			sldns_buffer_flip(buf);
560 			libworker_enter_result(*res, buf, region,
561 				q->msg_security);
562 		}
563 		(*res)->answer_packet = q->msg;
564 		(*res)->answer_len = (int)q->msg_len;
565 		q->msg = NULL;
566 		sldns_buffer_free(buf);
567 		regional_destroy(region);
568 	}
569 	q->res = NULL;
570 	/* delete the q from list */
571 	(void)rbtree_delete(&ctx->queries, q->node.key);
572 	ctx->num_async--;
573 	context_query_delete(q);
574 	lock_basic_unlock(&ctx->cfglock);
575 
576 	if(*cb) return 2;
577 	ub_resolve_free(*res);
578 	return 1;
579 }
580 
581 /** process answer from bg worker */
582 static int
583 process_answer(struct ub_ctx* ctx, uint8_t* msg, uint32_t len)
584 {
585 	int err;
586 	ub_callback_type cb;
587 	void* cbarg;
588 	struct ub_result* res;
589 	int r;
590 
591 	r = process_answer_detail(ctx, msg, len, &cb, &cbarg, &err, &res);
592 
593 	/* no locks held while calling callback, so that library is
594 	 * re-entrant. */
595 	if(r == 2)
596 		(*cb)(cbarg, err, res);
597 
598 	return r;
599 }
600 
601 int
602 ub_process(struct ub_ctx* ctx)
603 {
604 	int r;
605 	uint8_t* msg;
606 	uint32_t len;
607 	while(1) {
608 		msg = NULL;
609 		lock_basic_lock(&ctx->rrpipe_lock);
610 		r = tube_read_msg(ctx->rr_pipe, &msg, &len, 1);
611 		lock_basic_unlock(&ctx->rrpipe_lock);
612 		if(r == 0)
613 			return UB_PIPE;
614 		else if(r == -1)
615 			break;
616 		if(!process_answer(ctx, msg, len)) {
617 			free(msg);
618 			return UB_PIPE;
619 		}
620 		free(msg);
621 	}
622 	return UB_NOERROR;
623 }
624 
625 int
626 ub_wait(struct ub_ctx* ctx)
627 {
628 	int err;
629 	ub_callback_type cb;
630 	void* cbarg;
631 	struct ub_result* res;
632 	int r;
633 	uint8_t* msg;
634 	uint32_t len;
635 	/* this is basically the same loop as _process(), but with changes.
636 	 * holds the rrpipe lock and waits with tube_wait */
637 	while(1) {
638 		lock_basic_lock(&ctx->rrpipe_lock);
639 		lock_basic_lock(&ctx->cfglock);
640 		if(ctx->num_async == 0) {
641 			lock_basic_unlock(&ctx->cfglock);
642 			lock_basic_unlock(&ctx->rrpipe_lock);
643 			break;
644 		}
645 		lock_basic_unlock(&ctx->cfglock);
646 
647 		/* keep rrpipe locked, while
648 		 * 	o waiting for pipe readable
649 		 * 	o parsing message
650 		 * 	o possibly decrementing num_async
651 		 * do callback without lock
652 		 */
653 		r = tube_wait(ctx->rr_pipe);
654 		if(r) {
655 			r = tube_read_msg(ctx->rr_pipe, &msg, &len, 1);
656 			if(r == 0) {
657 				lock_basic_unlock(&ctx->rrpipe_lock);
658 				return UB_PIPE;
659 			}
660 			if(r == -1) {
661 				lock_basic_unlock(&ctx->rrpipe_lock);
662 				continue;
663 			}
664 			r = process_answer_detail(ctx, msg, len,
665 				&cb, &cbarg, &err, &res);
666 			lock_basic_unlock(&ctx->rrpipe_lock);
667 			free(msg);
668 			if(r == 0)
669 				return UB_PIPE;
670 			if(r == 2)
671 				(*cb)(cbarg, err, res);
672 		} else {
673 			lock_basic_unlock(&ctx->rrpipe_lock);
674 		}
675 	}
676 	return UB_NOERROR;
677 }
678 
679 int
680 ub_resolve(struct ub_ctx* ctx, const char* name, int rrtype,
681 	int rrclass, struct ub_result** result)
682 {
683 	struct ctx_query* q;
684 	int r;
685 	*result = NULL;
686 
687 	lock_basic_lock(&ctx->cfglock);
688 	if(!ctx->finalized) {
689 		r = context_finalize(ctx);
690 		if(r) {
691 			lock_basic_unlock(&ctx->cfglock);
692 			return r;
693 		}
694 	}
695 	/* create new ctx_query and attempt to add to the list */
696 	lock_basic_unlock(&ctx->cfglock);
697 	q = context_new(ctx, name, rrtype, rrclass, NULL, NULL, NULL);
698 	if(!q)
699 		return UB_NOMEM;
700 	/* become a resolver thread for a bit */
701 
702 	r = libworker_fg(ctx, q);
703 	if(r) {
704 		lock_basic_lock(&ctx->cfglock);
705 		(void)rbtree_delete(&ctx->queries, q->node.key);
706 		context_query_delete(q);
707 		lock_basic_unlock(&ctx->cfglock);
708 		return r;
709 	}
710 	q->res->answer_packet = q->msg;
711 	q->res->answer_len = (int)q->msg_len;
712 	q->msg = NULL;
713 	*result = q->res;
714 	q->res = NULL;
715 
716 	lock_basic_lock(&ctx->cfglock);
717 	(void)rbtree_delete(&ctx->queries, q->node.key);
718 	context_query_delete(q);
719 	lock_basic_unlock(&ctx->cfglock);
720 	return UB_NOERROR;
721 }
722 
723 int
724 ub_resolve_event(struct ub_ctx* ctx, const char* name, int rrtype,
725 	int rrclass, void* mydata, ub_event_callback_type callback,
726 	int* async_id)
727 {
728 	struct ctx_query* q;
729 	int r;
730 
731 	if(async_id)
732 		*async_id = 0;
733 	lock_basic_lock(&ctx->cfglock);
734 	if(!ctx->finalized) {
735 		r = context_finalize(ctx);
736 		if(r) {
737 			lock_basic_unlock(&ctx->cfglock);
738 			return r;
739 		}
740 	}
741 	lock_basic_unlock(&ctx->cfglock);
742 	if(!ctx->event_worker) {
743 		ctx->event_worker = libworker_create_event(ctx,
744 			ctx->event_base);
745 		if(!ctx->event_worker) {
746 			return UB_INITFAIL;
747 		}
748 	}
749 
750 	/* set time in case answer comes from cache */
751 	ub_comm_base_now(ctx->event_worker->base);
752 
753 	/* create new ctx_query and attempt to add to the list */
754 	q = context_new(ctx, name, rrtype, rrclass, NULL, callback, mydata);
755 	if(!q)
756 		return UB_NOMEM;
757 
758 	/* attach to mesh */
759 	if((r=libworker_attach_mesh(ctx, q, async_id)) != 0)
760 		return r;
761 	return UB_NOERROR;
762 }
763 
764 
765 int
766 ub_resolve_async(struct ub_ctx* ctx, const char* name, int rrtype,
767 	int rrclass, void* mydata, ub_callback_type callback, int* async_id)
768 {
769 	struct ctx_query* q;
770 	uint8_t* msg = NULL;
771 	uint32_t len = 0;
772 
773 	if(async_id)
774 		*async_id = 0;
775 	lock_basic_lock(&ctx->cfglock);
776 	if(!ctx->finalized) {
777 		int r = context_finalize(ctx);
778 		if(r) {
779 			lock_basic_unlock(&ctx->cfglock);
780 			return r;
781 		}
782 	}
783 	if(!ctx->created_bg) {
784 		int r;
785 		ctx->created_bg = 1;
786 		lock_basic_unlock(&ctx->cfglock);
787 		r = libworker_bg(ctx);
788 		if(r) {
789 			lock_basic_lock(&ctx->cfglock);
790 			ctx->created_bg = 0;
791 			lock_basic_unlock(&ctx->cfglock);
792 			return r;
793 		}
794 	} else {
795 		lock_basic_unlock(&ctx->cfglock);
796 	}
797 
798 	/* create new ctx_query and attempt to add to the list */
799 	q = context_new(ctx, name, rrtype, rrclass, callback, NULL, mydata);
800 	if(!q)
801 		return UB_NOMEM;
802 
803 	/* write over pipe to background worker */
804 	lock_basic_lock(&ctx->cfglock);
805 	msg = context_serialize_new_query(q, &len);
806 	if(!msg) {
807 		(void)rbtree_delete(&ctx->queries, q->node.key);
808 		ctx->num_async--;
809 		context_query_delete(q);
810 		lock_basic_unlock(&ctx->cfglock);
811 		return UB_NOMEM;
812 	}
813 	if(async_id)
814 		*async_id = q->querynum;
815 	lock_basic_unlock(&ctx->cfglock);
816 
817 	lock_basic_lock(&ctx->qqpipe_lock);
818 	if(!tube_write_msg(ctx->qq_pipe, msg, len, 0)) {
819 		lock_basic_unlock(&ctx->qqpipe_lock);
820 		free(msg);
821 		return UB_PIPE;
822 	}
823 	lock_basic_unlock(&ctx->qqpipe_lock);
824 	free(msg);
825 	return UB_NOERROR;
826 }
827 
828 int
829 ub_cancel(struct ub_ctx* ctx, int async_id)
830 {
831 	struct ctx_query* q;
832 	uint8_t* msg = NULL;
833 	uint32_t len = 0;
834 	lock_basic_lock(&ctx->cfglock);
835 	q = (struct ctx_query*)rbtree_search(&ctx->queries, &async_id);
836 	if(!q || !q->async) {
837 		/* it is not there, so nothing to do */
838 		lock_basic_unlock(&ctx->cfglock);
839 		return UB_NOID;
840 	}
841 	log_assert(q->async);
842 	q->cancelled = 1;
843 
844 	/* delete it */
845 	if(!ctx->dothread) { /* if forked */
846 		(void)rbtree_delete(&ctx->queries, q->node.key);
847 		ctx->num_async--;
848 		msg = context_serialize_cancel(q, &len);
849 		context_query_delete(q);
850 		lock_basic_unlock(&ctx->cfglock);
851 		if(!msg) {
852 			return UB_NOMEM;
853 		}
854 		/* send cancel to background worker */
855 		lock_basic_lock(&ctx->qqpipe_lock);
856 		if(!tube_write_msg(ctx->qq_pipe, msg, len, 0)) {
857 			lock_basic_unlock(&ctx->qqpipe_lock);
858 			free(msg);
859 			return UB_PIPE;
860 		}
861 		lock_basic_unlock(&ctx->qqpipe_lock);
862 		free(msg);
863 	} else {
864 		lock_basic_unlock(&ctx->cfglock);
865 	}
866 	return UB_NOERROR;
867 }
868 
869 void
870 ub_resolve_free(struct ub_result* result)
871 {
872 	char** p;
873 	if(!result) return;
874 	free(result->qname);
875 	if(result->canonname != result->qname)
876 		free(result->canonname);
877 	if(result->data)
878 		for(p = result->data; *p; p++)
879 			free(*p);
880 	free(result->data);
881 	free(result->len);
882 	free(result->answer_packet);
883 	free(result->why_bogus);
884 	free(result);
885 }
886 
887 const char*
888 ub_strerror(int err)
889 {
890 	switch(err) {
891 		case UB_NOERROR: return "no error";
892 		case UB_SOCKET: return "socket io error";
893 		case UB_NOMEM: return "out of memory";
894 		case UB_SYNTAX: return "syntax error";
895 		case UB_SERVFAIL: return "server failure";
896 		case UB_FORKFAIL: return "could not fork";
897 		case UB_INITFAIL: return "initialization failure";
898 		case UB_AFTERFINAL: return "setting change after finalize";
899 		case UB_PIPE: return "error in pipe communication with async";
900 		case UB_READFILE: return "error reading file";
901 		case UB_NOID: return "error async_id does not exist";
902 		default: return "unknown error";
903 	}
904 }
905 
906 int
907 ub_ctx_set_fwd(struct ub_ctx* ctx, const char* addr)
908 {
909 	struct sockaddr_storage storage;
910 	socklen_t stlen;
911 	struct config_stub* s;
912 	char* dupl;
913 	lock_basic_lock(&ctx->cfglock);
914 	if(ctx->finalized) {
915 		lock_basic_unlock(&ctx->cfglock);
916 		errno=EINVAL;
917 		return UB_AFTERFINAL;
918 	}
919 	if(!addr) {
920 		/* disable fwd mode - the root stub should be first. */
921 		if(ctx->env->cfg->forwards &&
922 			strcmp(ctx->env->cfg->forwards->name, ".") == 0) {
923 			s = ctx->env->cfg->forwards;
924 			ctx->env->cfg->forwards = s->next;
925 			s->next = NULL;
926 			config_delstubs(s);
927 		}
928 		lock_basic_unlock(&ctx->cfglock);
929 		return UB_NOERROR;
930 	}
931 	lock_basic_unlock(&ctx->cfglock);
932 
933 	/* check syntax for addr */
934 	if(!extstrtoaddr(addr, &storage, &stlen)) {
935 		errno=EINVAL;
936 		return UB_SYNTAX;
937 	}
938 
939 	/* it parses, add root stub in front of list */
940 	lock_basic_lock(&ctx->cfglock);
941 	if(!ctx->env->cfg->forwards ||
942 		strcmp(ctx->env->cfg->forwards->name, ".") != 0) {
943 		s = calloc(1, sizeof(*s));
944 		if(!s) {
945 			lock_basic_unlock(&ctx->cfglock);
946 			errno=ENOMEM;
947 			return UB_NOMEM;
948 		}
949 		s->name = strdup(".");
950 		if(!s->name) {
951 			free(s);
952 			lock_basic_unlock(&ctx->cfglock);
953 			errno=ENOMEM;
954 			return UB_NOMEM;
955 		}
956 		s->next = ctx->env->cfg->forwards;
957 		ctx->env->cfg->forwards = s;
958 	} else {
959 		log_assert(ctx->env->cfg->forwards);
960 		s = ctx->env->cfg->forwards;
961 	}
962 	dupl = strdup(addr);
963 	if(!dupl) {
964 		lock_basic_unlock(&ctx->cfglock);
965 		errno=ENOMEM;
966 		return UB_NOMEM;
967 	}
968 	if(!cfg_strlist_insert(&s->addrs, dupl)) {
969 		lock_basic_unlock(&ctx->cfglock);
970 		errno=ENOMEM;
971 		return UB_NOMEM;
972 	}
973 	lock_basic_unlock(&ctx->cfglock);
974 	return UB_NOERROR;
975 }
976 
977 int ub_ctx_set_tls(struct ub_ctx* ctx, int tls)
978 {
979 	lock_basic_lock(&ctx->cfglock);
980 	if(ctx->finalized) {
981 		lock_basic_unlock(&ctx->cfglock);
982 		errno=EINVAL;
983 		return UB_AFTERFINAL;
984 	}
985 	ctx->env->cfg->ssl_upstream = tls;
986 	lock_basic_unlock(&ctx->cfglock);
987 	return UB_NOERROR;
988 }
989 
990 int ub_ctx_set_stub(struct ub_ctx* ctx, const char* zone, const char* addr,
991 	int isprime)
992 {
993 	char* a;
994 	struct config_stub **prev, *elem;
995 
996 	/* check syntax for zone name */
997 	if(zone) {
998 		uint8_t* nm;
999 		int nmlabs;
1000 		size_t nmlen;
1001 		if(!parse_dname(zone, &nm, &nmlen, &nmlabs)) {
1002 			errno=EINVAL;
1003 			return UB_SYNTAX;
1004 		}
1005 		free(nm);
1006 	} else {
1007 		zone = ".";
1008 	}
1009 
1010 	/* check syntax for addr (if not NULL) */
1011 	if(addr) {
1012 		struct sockaddr_storage storage;
1013 		socklen_t stlen;
1014 		if(!extstrtoaddr(addr, &storage, &stlen)) {
1015 			errno=EINVAL;
1016 			return UB_SYNTAX;
1017 		}
1018 	}
1019 
1020 	lock_basic_lock(&ctx->cfglock);
1021 	if(ctx->finalized) {
1022 		lock_basic_unlock(&ctx->cfglock);
1023 		errno=EINVAL;
1024 		return UB_AFTERFINAL;
1025 	}
1026 
1027 	/* arguments all right, now find or add the stub */
1028 	prev = &ctx->env->cfg->stubs;
1029 	elem = cfg_stub_find(&prev, zone);
1030 	if(!elem && !addr) {
1031 		/* not found and we want to delete, nothing to do */
1032 		lock_basic_unlock(&ctx->cfglock);
1033 		return UB_NOERROR;
1034 	} else if(elem && !addr) {
1035 		/* found, and we want to delete */
1036 		*prev = elem->next;
1037 		config_delstub(elem);
1038 		lock_basic_unlock(&ctx->cfglock);
1039 		return UB_NOERROR;
1040 	} else if(!elem) {
1041 		/* not found, create the stub entry */
1042 		elem=(struct config_stub*)calloc(1, sizeof(struct config_stub));
1043 		if(elem) elem->name = strdup(zone);
1044 		if(!elem || !elem->name) {
1045 			free(elem);
1046 			lock_basic_unlock(&ctx->cfglock);
1047 			errno = ENOMEM;
1048 			return UB_NOMEM;
1049 		}
1050 		elem->next = ctx->env->cfg->stubs;
1051 		ctx->env->cfg->stubs = elem;
1052 	}
1053 
1054 	/* add the address to the list and set settings */
1055 	elem->isprime = isprime;
1056 	a = strdup(addr);
1057 	if(!a) {
1058 		lock_basic_unlock(&ctx->cfglock);
1059 		errno = ENOMEM;
1060 		return UB_NOMEM;
1061 	}
1062 	if(!cfg_strlist_insert(&elem->addrs, a)) {
1063 		lock_basic_unlock(&ctx->cfglock);
1064 		errno = ENOMEM;
1065 		return UB_NOMEM;
1066 	}
1067 	lock_basic_unlock(&ctx->cfglock);
1068 	return UB_NOERROR;
1069 }
1070 
1071 int
1072 ub_ctx_resolvconf(struct ub_ctx* ctx, const char* fname)
1073 {
1074 	FILE* in;
1075 	int numserv = 0;
1076 	char buf[1024];
1077 	char* parse, *addr;
1078 	int r;
1079 
1080 	if(fname == NULL) {
1081 #if !defined(UB_ON_WINDOWS) || !defined(HAVE_WINDOWS_H)
1082 		fname = "/etc/resolv.conf";
1083 #else
1084 		FIXED_INFO *info;
1085 		ULONG buflen = sizeof(*info);
1086 		IP_ADDR_STRING *ptr;
1087 
1088 		info = (FIXED_INFO *) malloc(sizeof (FIXED_INFO));
1089 		if (info == NULL)
1090 			return UB_READFILE;
1091 
1092 		if (GetNetworkParams(info, &buflen) == ERROR_BUFFER_OVERFLOW) {
1093 			free(info);
1094 			info = (FIXED_INFO *) malloc(buflen);
1095 			if (info == NULL)
1096 				return UB_READFILE;
1097 		}
1098 
1099 		if (GetNetworkParams(info, &buflen) == NO_ERROR) {
1100 			int retval=0;
1101 			ptr = &(info->DnsServerList);
1102 			while (ptr) {
1103 				numserv++;
1104 				if((retval=ub_ctx_set_fwd(ctx,
1105 					ptr->IpAddress.String))!=0) {
1106 					free(info);
1107 					return retval;
1108 				}
1109 				ptr = ptr->Next;
1110 			}
1111 			free(info);
1112 			if (numserv==0)
1113 				return UB_READFILE;
1114 			return UB_NOERROR;
1115 		}
1116 		free(info);
1117 		return UB_READFILE;
1118 #endif /* WINDOWS */
1119 	}
1120 	in = fopen(fname, "r");
1121 	if(!in) {
1122 		/* error in errno! perror(fname) */
1123 		return UB_READFILE;
1124 	}
1125 	while(fgets(buf, (int)sizeof(buf), in)) {
1126 		buf[sizeof(buf)-1] = 0;
1127 		parse=buf;
1128 		while(*parse == ' ' || *parse == '\t')
1129 			parse++;
1130 		if(strncmp(parse, "nameserver", 10) == 0) {
1131 			numserv++;
1132 			parse += 10; /* skip 'nameserver' */
1133 			/* skip whitespace */
1134 			while(*parse == ' ' || *parse == '\t')
1135 				parse++;
1136 			addr = parse;
1137 			/* skip [0-9a-fA-F.:]*, i.e. IP4 and IP6 address */
1138 			while(isxdigit((unsigned char)*parse) || *parse=='.' || *parse==':')
1139 				parse++;
1140 			/* terminate after the address, remove newline */
1141 			*parse = 0;
1142 
1143 			if((r = ub_ctx_set_fwd(ctx, addr)) != UB_NOERROR) {
1144 				fclose(in);
1145 				return r;
1146 			}
1147 		}
1148 	}
1149 	fclose(in);
1150 	if(numserv == 0) {
1151 		/* from resolv.conf(5) if none given, use localhost */
1152 		return ub_ctx_set_fwd(ctx, "127.0.0.1");
1153 	}
1154 	return UB_NOERROR;
1155 }
1156 
1157 int
1158 ub_ctx_hosts(struct ub_ctx* ctx, const char* fname)
1159 {
1160 	FILE* in;
1161 	char buf[1024], ldata[2048];
1162 	char* parse, *addr, *name, *ins;
1163 	lock_basic_lock(&ctx->cfglock);
1164 	if(ctx->finalized) {
1165 		lock_basic_unlock(&ctx->cfglock);
1166 		errno=EINVAL;
1167 		return UB_AFTERFINAL;
1168 	}
1169 	lock_basic_unlock(&ctx->cfglock);
1170 	if(fname == NULL) {
1171 #if defined(UB_ON_WINDOWS) && defined(HAVE_WINDOWS_H)
1172 		/*
1173 		 * If this is Windows NT/XP/2K it's in
1174 		 * %WINDIR%\system32\drivers\etc\hosts.
1175 		 * If this is Windows 95/98/Me it's in %WINDIR%\hosts.
1176 		 */
1177 		name = getenv("WINDIR");
1178 		if (name != NULL) {
1179 			int retval=0;
1180 			snprintf(buf, sizeof(buf), "%s%s", name,
1181 				"\\system32\\drivers\\etc\\hosts");
1182 			if((retval=ub_ctx_hosts(ctx, buf)) !=0 ) {
1183 				snprintf(buf, sizeof(buf), "%s%s", name,
1184 					"\\hosts");
1185 				retval=ub_ctx_hosts(ctx, buf);
1186 			}
1187 			return retval;
1188 		}
1189 		return UB_READFILE;
1190 #else
1191 		fname = "/etc/hosts";
1192 #endif /* WIN32 */
1193 	}
1194 	in = fopen(fname, "r");
1195 	if(!in) {
1196 		/* error in errno! perror(fname) */
1197 		return UB_READFILE;
1198 	}
1199 	while(fgets(buf, (int)sizeof(buf), in)) {
1200 		buf[sizeof(buf)-1] = 0;
1201 		parse=buf;
1202 		while(*parse == ' ' || *parse == '\t')
1203 			parse++;
1204 		if(*parse == '#')
1205 			continue; /* skip comment */
1206 		/* format: <addr> spaces <name> spaces <name> ... */
1207 		addr = parse;
1208 		/* skip addr */
1209 		while(isxdigit((unsigned char)*parse) || *parse == '.' || *parse == ':')
1210 			parse++;
1211 		if(*parse == '\r')
1212 			parse++;
1213 		if(*parse == '\n' || *parse == 0)
1214 			continue;
1215 		if(*parse == '%')
1216 			continue; /* ignore macOSX fe80::1%lo0 localhost */
1217 		if(*parse != ' ' && *parse != '\t') {
1218 			/* must have whitespace after address */
1219 			fclose(in);
1220 			errno=EINVAL;
1221 			return UB_SYNTAX;
1222 		}
1223 		*parse++ = 0; /* end delimiter for addr ... */
1224 		/* go to names and add them */
1225 		while(*parse) {
1226 			while(*parse == ' ' || *parse == '\t' || *parse=='\n'
1227 				|| *parse=='\r')
1228 				parse++;
1229 			if(*parse == 0 || *parse == '#')
1230 				break;
1231 			/* skip name, allows (too) many printable characters */
1232 			name = parse;
1233 			while('!' <= *parse && *parse <= '~')
1234 				parse++;
1235 			if(*parse)
1236 				*parse++ = 0; /* end delimiter for name */
1237 			snprintf(ldata, sizeof(ldata), "%s %s %s",
1238 				name, str_is_ip6(addr)?"AAAA":"A", addr);
1239 			ins = strdup(ldata);
1240 			if(!ins) {
1241 				/* out of memory */
1242 				fclose(in);
1243 				errno=ENOMEM;
1244 				return UB_NOMEM;
1245 			}
1246 			lock_basic_lock(&ctx->cfglock);
1247 			if(!cfg_strlist_insert(&ctx->env->cfg->local_data,
1248 				ins)) {
1249 				lock_basic_unlock(&ctx->cfglock);
1250 				fclose(in);
1251 				errno=ENOMEM;
1252 				return UB_NOMEM;
1253 			}
1254 			lock_basic_unlock(&ctx->cfglock);
1255 		}
1256 	}
1257 	fclose(in);
1258 	return UB_NOERROR;
1259 }
1260 
1261 /** finalize the context, if not already finalized */
1262 static int ub_ctx_finalize(struct ub_ctx* ctx)
1263 {
1264 	int res = 0;
1265 	lock_basic_lock(&ctx->cfglock);
1266 	if (!ctx->finalized) {
1267 		res = context_finalize(ctx);
1268 	}
1269 	lock_basic_unlock(&ctx->cfglock);
1270 	return res;
1271 }
1272 
1273 /* Print local zones and RR data */
1274 int ub_ctx_print_local_zones(struct ub_ctx* ctx)
1275 {
1276 	int res = ub_ctx_finalize(ctx);
1277 	if (res) return res;
1278 
1279 	local_zones_print(ctx->local_zones);
1280 
1281 	return UB_NOERROR;
1282 }
1283 
1284 /* Add a new zone */
1285 int ub_ctx_zone_add(struct ub_ctx* ctx, const char *zone_name,
1286 	const char *zone_type)
1287 {
1288 	enum localzone_type t;
1289 	struct local_zone* z;
1290 	uint8_t* nm;
1291 	int nmlabs;
1292 	size_t nmlen;
1293 
1294 	int res = ub_ctx_finalize(ctx);
1295 	if (res) return res;
1296 
1297 	if(!local_zone_str2type(zone_type, &t)) {
1298 		return UB_SYNTAX;
1299 	}
1300 
1301 	if(!parse_dname(zone_name, &nm, &nmlen, &nmlabs)) {
1302 		return UB_SYNTAX;
1303 	}
1304 
1305 	lock_rw_wrlock(&ctx->local_zones->lock);
1306 	if((z=local_zones_find(ctx->local_zones, nm, nmlen, nmlabs,
1307 		LDNS_RR_CLASS_IN))) {
1308 		/* already present in tree */
1309 		lock_rw_wrlock(&z->lock);
1310 		z->type = t; /* update type anyway */
1311 		lock_rw_unlock(&z->lock);
1312 		lock_rw_unlock(&ctx->local_zones->lock);
1313 		free(nm);
1314 		return UB_NOERROR;
1315 	}
1316 	if(!local_zones_add_zone(ctx->local_zones, nm, nmlen, nmlabs,
1317 		LDNS_RR_CLASS_IN, t)) {
1318 		lock_rw_unlock(&ctx->local_zones->lock);
1319 		return UB_NOMEM;
1320 	}
1321 	lock_rw_unlock(&ctx->local_zones->lock);
1322 	return UB_NOERROR;
1323 }
1324 
1325 /* Remove zone */
1326 int ub_ctx_zone_remove(struct ub_ctx* ctx, const char *zone_name)
1327 {
1328 	struct local_zone* z;
1329 	uint8_t* nm;
1330 	int nmlabs;
1331 	size_t nmlen;
1332 
1333 	int res = ub_ctx_finalize(ctx);
1334 	if (res) return res;
1335 
1336 	if(!parse_dname(zone_name, &nm, &nmlen, &nmlabs)) {
1337 		return UB_SYNTAX;
1338 	}
1339 
1340 	lock_rw_wrlock(&ctx->local_zones->lock);
1341 	if((z=local_zones_find(ctx->local_zones, nm, nmlen, nmlabs,
1342 		LDNS_RR_CLASS_IN))) {
1343 		/* present in tree */
1344 		local_zones_del_zone(ctx->local_zones, z);
1345 	}
1346 	lock_rw_unlock(&ctx->local_zones->lock);
1347 	free(nm);
1348 	return UB_NOERROR;
1349 }
1350 
1351 /* Add new RR data */
1352 int ub_ctx_data_add(struct ub_ctx* ctx, const char *data)
1353 {
1354 	int res = ub_ctx_finalize(ctx);
1355 	if (res) return res;
1356 
1357 	res = local_zones_add_RR(ctx->local_zones, data);
1358 	return (!res) ? UB_NOMEM : UB_NOERROR;
1359 }
1360 
1361 /* Remove RR data */
1362 int ub_ctx_data_remove(struct ub_ctx* ctx, const char *data)
1363 {
1364 	uint8_t* nm;
1365 	int nmlabs;
1366 	size_t nmlen;
1367 	int res = ub_ctx_finalize(ctx);
1368 	if (res) return res;
1369 
1370 	if(!parse_dname(data, &nm, &nmlen, &nmlabs))
1371 		return UB_SYNTAX;
1372 
1373 	local_zones_del_data(ctx->local_zones, nm, nmlen, nmlabs,
1374 		LDNS_RR_CLASS_IN);
1375 
1376 	free(nm);
1377 	return UB_NOERROR;
1378 }
1379 
1380 const char* ub_version(void)
1381 {
1382 	return PACKAGE_VERSION;
1383 }
1384 
1385 int
1386 ub_ctx_set_event(struct ub_ctx* ctx, struct event_base* base) {
1387 	struct ub_event_base* new_base;
1388 
1389 	if (!ctx || !ctx->event_base || !base) {
1390 		return UB_INITFAIL;
1391 	}
1392 	if (ub_libevent_get_event_base(ctx->event_base) == base) {
1393 		/* already set */
1394 		return UB_NOERROR;
1395 	}
1396 
1397 	lock_basic_lock(&ctx->cfglock);
1398 	/* destroy the current worker - safe to pass in NULL */
1399 	libworker_delete_event(ctx->event_worker);
1400 	ctx->event_worker = NULL;
1401 	new_base = ub_libevent_event_base(base);
1402 	if (new_base)
1403 		ctx->event_base = new_base;
1404 	ctx->created_bg = 0;
1405 	ctx->dothread = 1;
1406 	lock_basic_unlock(&ctx->cfglock);
1407 	return new_base ? UB_NOERROR : UB_INITFAIL;
1408 }
1409