xref: /freebsd/contrib/unbound/util/data/msgreply.c (revision e8d8bef961a50d4dc22501cde4fb9fb0be1b2532)
1 /*
2  * util/data/msgreply.c - store message and reply data.
3  *
4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * This file contains a data structure to store a message and its reply.
40  */
41 
42 #include "config.h"
43 #include "util/data/msgreply.h"
44 #include "util/storage/lookup3.h"
45 #include "util/log.h"
46 #include "util/alloc.h"
47 #include "util/netevent.h"
48 #include "util/net_help.h"
49 #include "util/data/dname.h"
50 #include "util/regional.h"
51 #include "util/data/msgparse.h"
52 #include "util/data/msgencode.h"
53 #include "sldns/sbuffer.h"
54 #include "sldns/wire2str.h"
55 #include "util/module.h"
56 #include "util/fptr_wlist.h"
57 
58 /** MAX TTL default for messages and rrsets */
59 time_t MAX_TTL = 3600 * 24 * 10; /* ten days */
60 /** MIN TTL default for messages and rrsets */
61 time_t MIN_TTL = 0;
62 /** MAX Negative TTL, for SOA records in authority section */
63 time_t MAX_NEG_TTL = 3600; /* one hour */
64 /** If we serve expired entries and prefetch them */
65 int SERVE_EXPIRED = 0;
66 /** Time to serve records after expiration */
67 time_t SERVE_EXPIRED_TTL = 0;
68 /** TTL to use for expired records */
69 time_t SERVE_EXPIRED_REPLY_TTL = 30;
70 /** If we serve the original TTL or decrementing TTLs */
71 int SERVE_ORIGINAL_TTL = 0;
72 
73 /** allocate qinfo, return 0 on error */
74 static int
75 parse_create_qinfo(sldns_buffer* pkt, struct msg_parse* msg,
76 	struct query_info* qinf, struct regional* region)
77 {
78 	if(msg->qname) {
79 		if(region)
80 			qinf->qname = (uint8_t*)regional_alloc(region,
81 				msg->qname_len);
82 		else	qinf->qname = (uint8_t*)malloc(msg->qname_len);
83 		if(!qinf->qname) return 0;
84 		dname_pkt_copy(pkt, qinf->qname, msg->qname);
85 	} else	qinf->qname = 0;
86 	qinf->qname_len = msg->qname_len;
87 	qinf->qtype = msg->qtype;
88 	qinf->qclass = msg->qclass;
89 	qinf->local_alias = NULL;
90 	return 1;
91 }
92 
93 /** constructor for replyinfo */
94 struct reply_info*
95 construct_reply_info_base(struct regional* region, uint16_t flags, size_t qd,
96 	time_t ttl, time_t prettl, time_t expttl, size_t an, size_t ns,
97 	size_t ar, size_t total, enum sec_status sec)
98 {
99 	struct reply_info* rep;
100 	/* rrset_count-1 because the first ref is part of the struct. */
101 	size_t s = sizeof(struct reply_info) - sizeof(struct rrset_ref) +
102 		sizeof(struct ub_packed_rrset_key*) * total;
103 	if(total >= RR_COUNT_MAX) return NULL; /* sanity check on numRRS*/
104 	if(region)
105 		rep = (struct reply_info*)regional_alloc(region, s);
106 	else	rep = (struct reply_info*)malloc(s +
107 			sizeof(struct rrset_ref) * (total));
108 	if(!rep)
109 		return NULL;
110 	rep->flags = flags;
111 	rep->qdcount = qd;
112 	rep->ttl = ttl;
113 	rep->prefetch_ttl = prettl;
114 	rep->serve_expired_ttl = expttl;
115 	rep->an_numrrsets = an;
116 	rep->ns_numrrsets = ns;
117 	rep->ar_numrrsets = ar;
118 	rep->rrset_count = total;
119 	rep->security = sec;
120 	rep->authoritative = 0;
121 	/* array starts after the refs */
122 	if(region)
123 		rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[0]);
124 	else	rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[total]);
125 	/* zero the arrays to assist cleanup in case of malloc failure */
126 	memset( rep->rrsets, 0, sizeof(struct ub_packed_rrset_key*) * total);
127 	if(!region)
128 		memset( &rep->ref[0], 0, sizeof(struct rrset_ref) * total);
129 	return rep;
130 }
131 
132 /** allocate replyinfo, return 0 on error */
133 static int
134 parse_create_repinfo(struct msg_parse* msg, struct reply_info** rep,
135 	struct regional* region)
136 {
137 	*rep = construct_reply_info_base(region, msg->flags, msg->qdcount, 0,
138 		0, 0, msg->an_rrsets, msg->ns_rrsets, msg->ar_rrsets,
139 		msg->rrset_count, sec_status_unchecked);
140 	if(!*rep)
141 		return 0;
142 	return 1;
143 }
144 
145 int
146 reply_info_alloc_rrset_keys(struct reply_info* rep, struct alloc_cache* alloc,
147 	struct regional* region)
148 {
149 	size_t i;
150 	for(i=0; i<rep->rrset_count; i++) {
151 		if(region) {
152 			rep->rrsets[i] = (struct ub_packed_rrset_key*)
153 				regional_alloc(region,
154 				sizeof(struct ub_packed_rrset_key));
155 			if(rep->rrsets[i]) {
156 				memset(rep->rrsets[i], 0,
157 					sizeof(struct ub_packed_rrset_key));
158 				rep->rrsets[i]->entry.key = rep->rrsets[i];
159 			}
160 		}
161 		else	rep->rrsets[i] = alloc_special_obtain(alloc);
162 		if(!rep->rrsets[i])
163 			return 0;
164 		rep->rrsets[i]->entry.data = NULL;
165 	}
166 	return 1;
167 }
168 
169 /** find the minimumttl in the rdata of SOA record */
170 static time_t
171 soa_find_minttl(struct rr_parse* rr)
172 {
173 	uint16_t rlen = sldns_read_uint16(rr->ttl_data+4);
174 	if(rlen < 20)
175 		return 0; /* rdata too small for SOA (dname, dname, 5*32bit) */
176 	/* minimum TTL is the last 32bit value in the rdata of the record */
177 	/* at position ttl_data + 4(ttl) + 2(rdatalen) + rdatalen - 4(timeval)*/
178 	return (time_t)sldns_read_uint32(rr->ttl_data+6+rlen-4);
179 }
180 
181 /** do the rdata copy */
182 static int
183 rdata_copy(sldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to,
184 	struct rr_parse* rr, time_t* rr_ttl, uint16_t type,
185 	sldns_pkt_section section)
186 {
187 	uint16_t pkt_len;
188 	const sldns_rr_descriptor* desc;
189 
190 	*rr_ttl = sldns_read_uint32(rr->ttl_data);
191 	/* RFC 2181 Section 8. if msb of ttl is set treat as if zero. */
192 	if(*rr_ttl & 0x80000000U)
193 		*rr_ttl = 0;
194 	if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) {
195 		/* negative response. see if TTL of SOA record larger than the
196 		 * minimum-ttl in the rdata of the SOA record */
197 		if(*rr_ttl > soa_find_minttl(rr))
198 			*rr_ttl = soa_find_minttl(rr);
199 		if(*rr_ttl > MAX_NEG_TTL)
200 			*rr_ttl = MAX_NEG_TTL;
201 	}
202 	if(!SERVE_ORIGINAL_TTL && (*rr_ttl < MIN_TTL))
203 		*rr_ttl = MIN_TTL;
204 	if(!SERVE_ORIGINAL_TTL && (*rr_ttl > MAX_TTL))
205 		*rr_ttl = MAX_TTL;
206 	if(*rr_ttl < data->ttl)
207 		data->ttl = *rr_ttl;
208 
209 	if(rr->outside_packet) {
210 		/* uncompressed already, only needs copy */
211 		memmove(to, rr->ttl_data+sizeof(uint32_t), rr->size);
212 		return 1;
213 	}
214 
215 	sldns_buffer_set_position(pkt, (size_t)
216 		(rr->ttl_data - sldns_buffer_begin(pkt) + sizeof(uint32_t)));
217 	/* insert decompressed size into rdata len stored in memory */
218 	/* -2 because rdatalen bytes are not included. */
219 	pkt_len = htons(rr->size - 2);
220 	memmove(to, &pkt_len, sizeof(uint16_t));
221 	to += 2;
222 	/* read packet rdata len */
223 	pkt_len = sldns_buffer_read_u16(pkt);
224 	if(sldns_buffer_remaining(pkt) < pkt_len)
225 		return 0;
226 	desc = sldns_rr_descript(type);
227 	if(pkt_len > 0 && desc && desc->_dname_count > 0) {
228 		int count = (int)desc->_dname_count;
229 		int rdf = 0;
230 		size_t len;
231 		size_t oldpos;
232 		/* decompress dnames. */
233 		while(pkt_len > 0 && count) {
234 			switch(desc->_wireformat[rdf]) {
235 			case LDNS_RDF_TYPE_DNAME:
236 				oldpos = sldns_buffer_position(pkt);
237 				dname_pkt_copy(pkt, to,
238 					sldns_buffer_current(pkt));
239 				to += pkt_dname_len(pkt);
240 				pkt_len -= sldns_buffer_position(pkt)-oldpos;
241 				count--;
242 				len = 0;
243 				break;
244 			case LDNS_RDF_TYPE_STR:
245 				len = sldns_buffer_current(pkt)[0] + 1;
246 				break;
247 			default:
248 				len = get_rdf_size(desc->_wireformat[rdf]);
249 				break;
250 			}
251 			if(len) {
252 				log_assert(len <= pkt_len);
253 				memmove(to, sldns_buffer_current(pkt), len);
254 				to += len;
255 				sldns_buffer_skip(pkt, (ssize_t)len);
256 				pkt_len -= len;
257 			}
258 			rdf++;
259 		}
260 	}
261 	/* copy remaining rdata */
262 	if(pkt_len >  0)
263 		memmove(to, sldns_buffer_current(pkt), pkt_len);
264 
265 	return 1;
266 }
267 
268 /** copy over the data into packed rrset */
269 static int
270 parse_rr_copy(sldns_buffer* pkt, struct rrset_parse* pset,
271 	struct packed_rrset_data* data)
272 {
273 	size_t i;
274 	struct rr_parse* rr = pset->rr_first;
275 	uint8_t* nextrdata;
276 	size_t total = pset->rr_count + pset->rrsig_count;
277 	data->ttl = MAX_TTL;
278 	data->count = pset->rr_count;
279 	data->rrsig_count = pset->rrsig_count;
280 	data->trust = rrset_trust_none;
281 	data->security = sec_status_unchecked;
282 	/* layout: struct - rr_len - rr_data - rr_ttl - rdata - rrsig */
283 	data->rr_len = (size_t*)((uint8_t*)data +
284 		sizeof(struct packed_rrset_data));
285 	data->rr_data = (uint8_t**)&(data->rr_len[total]);
286 	data->rr_ttl = (time_t*)&(data->rr_data[total]);
287 	nextrdata = (uint8_t*)&(data->rr_ttl[total]);
288 	for(i=0; i<data->count; i++) {
289 		data->rr_len[i] = rr->size;
290 		data->rr_data[i] = nextrdata;
291 		nextrdata += rr->size;
292 		if(!rdata_copy(pkt, data, data->rr_data[i], rr,
293 			&data->rr_ttl[i], pset->type, pset->section))
294 			return 0;
295 		rr = rr->next;
296 	}
297 	/* if rrsig, its rdata is at nextrdata */
298 	rr = pset->rrsig_first;
299 	for(i=data->count; i<total; i++) {
300 		data->rr_len[i] = rr->size;
301 		data->rr_data[i] = nextrdata;
302 		nextrdata += rr->size;
303 		if(!rdata_copy(pkt, data, data->rr_data[i], rr,
304 			&data->rr_ttl[i], LDNS_RR_TYPE_RRSIG, pset->section))
305 			return 0;
306 		rr = rr->next;
307 	}
308 	return 1;
309 }
310 
311 /** create rrset return 0 on failure */
312 static int
313 parse_create_rrset(sldns_buffer* pkt, struct rrset_parse* pset,
314 	struct packed_rrset_data** data, struct regional* region)
315 {
316 	/* allocate */
317 	size_t s;
318 	if(pset->rr_count > RR_COUNT_MAX || pset->rrsig_count > RR_COUNT_MAX ||
319 		pset->size > RR_COUNT_MAX)
320 		return 0; /* protect against integer overflow */
321 	s = sizeof(struct packed_rrset_data) +
322 		(pset->rr_count + pset->rrsig_count) *
323 		(sizeof(size_t)+sizeof(uint8_t*)+sizeof(time_t)) +
324 		pset->size;
325 	if(region)
326 		*data = regional_alloc_zero(region, s);
327 	else	*data = calloc(1, s);
328 	if(!*data)
329 		return 0;
330 	/* copy & decompress */
331 	if(!parse_rr_copy(pkt, pset, *data)) {
332 		if(!region) free(*data);
333 		return 0;
334 	}
335 	return 1;
336 }
337 
338 /** get trust value for rrset */
339 static enum rrset_trust
340 get_rrset_trust(struct msg_parse* msg, struct rrset_parse* rrset)
341 {
342 	uint16_t AA = msg->flags & BIT_AA;
343 	if(rrset->section == LDNS_SECTION_ANSWER) {
344 		if(AA) {
345 			/* RFC2181 says remainder of CNAME chain is nonauth*/
346 			if(msg->rrset_first &&
347 				msg->rrset_first->section==LDNS_SECTION_ANSWER
348 				&& msg->rrset_first->type==LDNS_RR_TYPE_CNAME){
349 				if(rrset == msg->rrset_first)
350 					return rrset_trust_ans_AA;
351 				else 	return rrset_trust_ans_noAA;
352 			}
353 			if(msg->rrset_first &&
354 				msg->rrset_first->section==LDNS_SECTION_ANSWER
355 				&& msg->rrset_first->type==LDNS_RR_TYPE_DNAME){
356 				if(rrset == msg->rrset_first ||
357 				   rrset == msg->rrset_first->rrset_all_next)
358 					return rrset_trust_ans_AA;
359 				else 	return rrset_trust_ans_noAA;
360 			}
361 			return rrset_trust_ans_AA;
362 		}
363 		else	return rrset_trust_ans_noAA;
364 	} else if(rrset->section == LDNS_SECTION_AUTHORITY) {
365 		if(AA)	return rrset_trust_auth_AA;
366 		else	return rrset_trust_auth_noAA;
367 	} else {
368 		/* addit section */
369 		if(AA)	return rrset_trust_add_AA;
370 		else	return rrset_trust_add_noAA;
371 	}
372 	/* NOTREACHED */
373 	return rrset_trust_none;
374 }
375 
376 int
377 parse_copy_decompress_rrset(sldns_buffer* pkt, struct msg_parse* msg,
378 	struct rrset_parse *pset, struct regional* region,
379 	struct ub_packed_rrset_key* pk)
380 {
381 	struct packed_rrset_data* data;
382 	pk->rk.flags = pset->flags;
383 	pk->rk.dname_len = pset->dname_len;
384 	if(region)
385 		pk->rk.dname = (uint8_t*)regional_alloc(
386 			region, pset->dname_len);
387 	else	pk->rk.dname =
388 			(uint8_t*)malloc(pset->dname_len);
389 	if(!pk->rk.dname)
390 		return 0;
391 	/** copy & decompress dname */
392 	dname_pkt_copy(pkt, pk->rk.dname, pset->dname);
393 	/** copy over type and class */
394 	pk->rk.type = htons(pset->type);
395 	pk->rk.rrset_class = pset->rrset_class;
396 	/** read data part. */
397 	if(!parse_create_rrset(pkt, pset, &data, region))
398 		return 0;
399 	pk->entry.data = (void*)data;
400 	pk->entry.key = (void*)pk;
401 	pk->entry.hash = pset->hash;
402 	data->trust = get_rrset_trust(msg, pset);
403 	return 1;
404 }
405 
406 /**
407  * Copy and decompress rrs
408  * @param pkt: the packet for compression pointer resolution.
409  * @param msg: the parsed message
410  * @param rep: reply info to put rrs into.
411  * @param region: if not NULL, used for allocation.
412  * @return 0 on failure.
413  */
414 static int
415 parse_copy_decompress(sldns_buffer* pkt, struct msg_parse* msg,
416 	struct reply_info* rep, struct regional* region)
417 {
418 	size_t i;
419 	struct rrset_parse *pset = msg->rrset_first;
420 	struct packed_rrset_data* data;
421 	log_assert(rep);
422 	rep->ttl = MAX_TTL;
423 	rep->security = sec_status_unchecked;
424 	if(rep->rrset_count == 0)
425 		rep->ttl = NORR_TTL;
426 
427 	for(i=0; i<rep->rrset_count; i++) {
428 		if(!parse_copy_decompress_rrset(pkt, msg, pset, region,
429 			rep->rrsets[i]))
430 			return 0;
431 		data = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
432 		if(data->ttl < rep->ttl)
433 			rep->ttl = data->ttl;
434 
435 		pset = pset->rrset_all_next;
436 	}
437 	rep->prefetch_ttl = PREFETCH_TTL_CALC(rep->ttl);
438 	rep->serve_expired_ttl = rep->ttl + SERVE_EXPIRED_TTL;
439 	return 1;
440 }
441 
442 int
443 parse_create_msg(sldns_buffer* pkt, struct msg_parse* msg,
444 	struct alloc_cache* alloc, struct query_info* qinf,
445 	struct reply_info** rep, struct regional* region)
446 {
447 	log_assert(pkt && msg);
448 	if(!parse_create_qinfo(pkt, msg, qinf, region))
449 		return 0;
450 	if(!parse_create_repinfo(msg, rep, region))
451 		return 0;
452 	if(!reply_info_alloc_rrset_keys(*rep, alloc, region)) {
453 		if(!region) reply_info_parsedelete(*rep, alloc);
454 		return 0;
455 	}
456 	if(!parse_copy_decompress(pkt, msg, *rep, region)) {
457 		if(!region) reply_info_parsedelete(*rep, alloc);
458 		return 0;
459 	}
460 	return 1;
461 }
462 
463 int reply_info_parse(sldns_buffer* pkt, struct alloc_cache* alloc,
464         struct query_info* qinf, struct reply_info** rep,
465 	struct regional* region, struct edns_data* edns)
466 {
467 	/* use scratch pad region-allocator during parsing. */
468 	struct msg_parse* msg;
469 	int ret;
470 
471 	qinf->qname = NULL;
472 	qinf->local_alias = NULL;
473 	*rep = NULL;
474 	if(!(msg = regional_alloc(region, sizeof(*msg)))) {
475 		return LDNS_RCODE_SERVFAIL;
476 	}
477 	memset(msg, 0, sizeof(*msg));
478 
479 	sldns_buffer_set_position(pkt, 0);
480 	if((ret = parse_packet(pkt, msg, region)) != 0) {
481 		return ret;
482 	}
483 	if((ret = parse_extract_edns(msg, edns, region)) != 0)
484 		return ret;
485 
486 	/* parse OK, allocate return structures */
487 	/* this also performs dname decompression */
488 	if(!parse_create_msg(pkt, msg, alloc, qinf, rep, NULL)) {
489 		query_info_clear(qinf);
490 		reply_info_parsedelete(*rep, alloc);
491 		*rep = NULL;
492 		return LDNS_RCODE_SERVFAIL;
493 	}
494 	return 0;
495 }
496 
497 /** helper compare function to sort in lock order */
498 static int
499 reply_info_sortref_cmp(const void* a, const void* b)
500 {
501 	struct rrset_ref* x = (struct rrset_ref*)a;
502 	struct rrset_ref* y = (struct rrset_ref*)b;
503 	if(x->key < y->key) return -1;
504 	if(x->key > y->key) return 1;
505 	return 0;
506 }
507 
508 void
509 reply_info_sortref(struct reply_info* rep)
510 {
511 	qsort(&rep->ref[0], rep->rrset_count, sizeof(struct rrset_ref),
512 		reply_info_sortref_cmp);
513 }
514 
515 void
516 reply_info_set_ttls(struct reply_info* rep, time_t timenow)
517 {
518 	size_t i, j;
519 	rep->ttl += timenow;
520 	rep->prefetch_ttl += timenow;
521 	rep->serve_expired_ttl += timenow;
522 	for(i=0; i<rep->rrset_count; i++) {
523 		struct packed_rrset_data* data = (struct packed_rrset_data*)
524 			rep->ref[i].key->entry.data;
525 		if(i>0 && rep->ref[i].key == rep->ref[i-1].key)
526 			continue;
527 		data->ttl += timenow;
528 		for(j=0; j<data->count + data->rrsig_count; j++) {
529 			data->rr_ttl[j] += timenow;
530 		}
531 		data->ttl_add = timenow;
532 	}
533 }
534 
535 void
536 reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc)
537 {
538 	size_t i;
539 	if(!rep)
540 		return;
541 	/* no need to lock, since not shared in hashtables. */
542 	for(i=0; i<rep->rrset_count; i++) {
543 		ub_packed_rrset_parsedelete(rep->rrsets[i], alloc);
544 	}
545 	free(rep);
546 }
547 
548 int
549 query_info_parse(struct query_info* m, sldns_buffer* query)
550 {
551 	uint8_t* q = sldns_buffer_begin(query);
552 	/* minimum size: header + \0 + qtype + qclass */
553 	if(sldns_buffer_limit(query) < LDNS_HEADER_SIZE + 5)
554 		return 0;
555 	if((LDNS_OPCODE_WIRE(q) != LDNS_PACKET_QUERY && LDNS_OPCODE_WIRE(q) !=
556 		LDNS_PACKET_NOTIFY) || LDNS_QDCOUNT(q) != 1 ||
557 		sldns_buffer_position(query) != 0)
558 		return 0;
559 	sldns_buffer_skip(query, LDNS_HEADER_SIZE);
560 	m->qname = sldns_buffer_current(query);
561 	if((m->qname_len = query_dname_len(query)) == 0)
562 		return 0; /* parse error */
563 	if(sldns_buffer_remaining(query) < 4)
564 		return 0; /* need qtype, qclass */
565 	m->qtype = sldns_buffer_read_u16(query);
566 	m->qclass = sldns_buffer_read_u16(query);
567 	m->local_alias = NULL;
568 	return 1;
569 }
570 
571 /** tiny subroutine for msgreply_compare */
572 #define COMPARE_IT(x, y) \
573 	if( (x) < (y) ) return -1; \
574 	else if( (x) > (y) ) return +1; \
575 	log_assert( (x) == (y) );
576 
577 int
578 query_info_compare(void* m1, void* m2)
579 {
580 	struct query_info* msg1 = (struct query_info*)m1;
581 	struct query_info* msg2 = (struct query_info*)m2;
582 	int mc;
583 	/* from most different to least different for speed */
584 	COMPARE_IT(msg1->qtype, msg2->qtype);
585 	if((mc = query_dname_compare(msg1->qname, msg2->qname)) != 0)
586 		return mc;
587 	log_assert(msg1->qname_len == msg2->qname_len);
588 	COMPARE_IT(msg1->qclass, msg2->qclass);
589 	return 0;
590 #undef COMPARE_IT
591 }
592 
593 void
594 query_info_clear(struct query_info* m)
595 {
596 	free(m->qname);
597 	m->qname = NULL;
598 }
599 
600 size_t
601 msgreply_sizefunc(void* k, void* d)
602 {
603 	struct msgreply_entry* q = (struct msgreply_entry*)k;
604 	struct reply_info* r = (struct reply_info*)d;
605 	size_t s = sizeof(struct msgreply_entry) + sizeof(struct reply_info)
606 		+ q->key.qname_len + lock_get_mem(&q->entry.lock)
607 		- sizeof(struct rrset_ref);
608 	s += r->rrset_count * sizeof(struct rrset_ref);
609 	s += r->rrset_count * sizeof(struct ub_packed_rrset_key*);
610 	return s;
611 }
612 
613 void
614 query_entry_delete(void *k, void* ATTR_UNUSED(arg))
615 {
616 	struct msgreply_entry* q = (struct msgreply_entry*)k;
617 	lock_rw_destroy(&q->entry.lock);
618 	query_info_clear(&q->key);
619 	free(q);
620 }
621 
622 void
623 reply_info_delete(void* d, void* ATTR_UNUSED(arg))
624 {
625 	struct reply_info* r = (struct reply_info*)d;
626 	free(r);
627 }
628 
629 hashvalue_type
630 query_info_hash(struct query_info *q, uint16_t flags)
631 {
632 	hashvalue_type h = 0xab;
633 	h = hashlittle(&q->qtype, sizeof(q->qtype), h);
634 	if(q->qtype == LDNS_RR_TYPE_AAAA && (flags&BIT_CD))
635 		h++;
636 	h = hashlittle(&q->qclass, sizeof(q->qclass), h);
637 	h = dname_query_hash(q->qname, h);
638 	return h;
639 }
640 
641 struct msgreply_entry*
642 query_info_entrysetup(struct query_info* q, struct reply_info* r,
643 	hashvalue_type h)
644 {
645 	struct msgreply_entry* e = (struct msgreply_entry*)malloc(
646 		sizeof(struct msgreply_entry));
647 	if(!e) return NULL;
648 	memcpy(&e->key, q, sizeof(*q));
649 	e->entry.hash = h;
650 	e->entry.key = e;
651 	e->entry.data = r;
652 	lock_rw_init(&e->entry.lock);
653 	lock_protect(&e->entry.lock, &e->key.qname, sizeof(e->key.qname));
654 	lock_protect(&e->entry.lock, &e->key.qname_len, sizeof(e->key.qname_len));
655 	lock_protect(&e->entry.lock, &e->key.qtype, sizeof(e->key.qtype));
656 	lock_protect(&e->entry.lock, &e->key.qclass, sizeof(e->key.qclass));
657 	lock_protect(&e->entry.lock, &e->key.local_alias, sizeof(e->key.local_alias));
658 	lock_protect(&e->entry.lock, &e->entry.hash, sizeof(e->entry.hash));
659 	lock_protect(&e->entry.lock, &e->entry.key, sizeof(e->entry.key));
660 	lock_protect(&e->entry.lock, &e->entry.data, sizeof(e->entry.data));
661 	lock_protect(&e->entry.lock, e->key.qname, e->key.qname_len);
662 	q->qname = NULL;
663 	return e;
664 }
665 
666 /** copy rrsets from replyinfo to dest replyinfo */
667 static int
668 repinfo_copy_rrsets(struct reply_info* dest, struct reply_info* from,
669 	struct regional* region)
670 {
671 	size_t i, s;
672 	struct packed_rrset_data* fd, *dd;
673 	struct ub_packed_rrset_key* fk, *dk;
674 	for(i=0; i<dest->rrset_count; i++) {
675 		fk = from->rrsets[i];
676 		dk = dest->rrsets[i];
677 		fd = (struct packed_rrset_data*)fk->entry.data;
678 		dk->entry.hash = fk->entry.hash;
679 		dk->rk = fk->rk;
680 		if(region) {
681 			dk->id = fk->id;
682 			dk->rk.dname = (uint8_t*)regional_alloc_init(region,
683 				fk->rk.dname, fk->rk.dname_len);
684 		} else
685 			dk->rk.dname = (uint8_t*)memdup(fk->rk.dname,
686 				fk->rk.dname_len);
687 		if(!dk->rk.dname)
688 			return 0;
689 		s = packed_rrset_sizeof(fd);
690 		if(region)
691 			dd = (struct packed_rrset_data*)regional_alloc_init(
692 				region, fd, s);
693 		else	dd = (struct packed_rrset_data*)memdup(fd, s);
694 		if(!dd)
695 			return 0;
696 		packed_rrset_ptr_fixup(dd);
697 		dk->entry.data = (void*)dd;
698 	}
699 	return 1;
700 }
701 
702 struct reply_info*
703 reply_info_copy(struct reply_info* rep, struct alloc_cache* alloc,
704 	struct regional* region)
705 {
706 	struct reply_info* cp;
707 	cp = construct_reply_info_base(region, rep->flags, rep->qdcount,
708 		rep->ttl, rep->prefetch_ttl, rep->serve_expired_ttl,
709 		rep->an_numrrsets, rep->ns_numrrsets, rep->ar_numrrsets,
710 		rep->rrset_count, rep->security);
711 	if(!cp)
712 		return NULL;
713 	/* allocate ub_key structures special or not */
714 	if(!reply_info_alloc_rrset_keys(cp, alloc, region)) {
715 		if(!region)
716 			reply_info_parsedelete(cp, alloc);
717 		return NULL;
718 	}
719 	if(!repinfo_copy_rrsets(cp, rep, region)) {
720 		if(!region)
721 			reply_info_parsedelete(cp, alloc);
722 		return NULL;
723 	}
724 	return cp;
725 }
726 
727 uint8_t*
728 reply_find_final_cname_target(struct query_info* qinfo, struct reply_info* rep)
729 {
730 	uint8_t* sname = qinfo->qname;
731 	size_t snamelen = qinfo->qname_len;
732 	size_t i;
733 	for(i=0; i<rep->an_numrrsets; i++) {
734 		struct ub_packed_rrset_key* s = rep->rrsets[i];
735 		/* follow CNAME chain (if any) */
736 		if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
737 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
738 			snamelen == s->rk.dname_len &&
739 			query_dname_compare(sname, s->rk.dname) == 0) {
740 			get_cname_target(s, &sname, &snamelen);
741 		}
742 	}
743 	if(sname != qinfo->qname)
744 		return sname;
745 	return NULL;
746 }
747 
748 struct ub_packed_rrset_key*
749 reply_find_answer_rrset(struct query_info* qinfo, struct reply_info* rep)
750 {
751 	uint8_t* sname = qinfo->qname;
752 	size_t snamelen = qinfo->qname_len;
753 	size_t i;
754 	for(i=0; i<rep->an_numrrsets; i++) {
755 		struct ub_packed_rrset_key* s = rep->rrsets[i];
756 		/* first match type, for query of qtype cname */
757 		if(ntohs(s->rk.type) == qinfo->qtype &&
758 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
759 			snamelen == s->rk.dname_len &&
760 			query_dname_compare(sname, s->rk.dname) == 0) {
761 			return s;
762 		}
763 		/* follow CNAME chain (if any) */
764 		if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
765 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
766 			snamelen == s->rk.dname_len &&
767 			query_dname_compare(sname, s->rk.dname) == 0) {
768 			get_cname_target(s, &sname, &snamelen);
769 		}
770 	}
771 	return NULL;
772 }
773 
774 struct ub_packed_rrset_key* reply_find_rrset_section_an(struct reply_info* rep,
775 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
776 {
777 	size_t i;
778 	for(i=0; i<rep->an_numrrsets; i++) {
779 		struct ub_packed_rrset_key* s = rep->rrsets[i];
780 		if(ntohs(s->rk.type) == type &&
781 			ntohs(s->rk.rrset_class) == dclass &&
782 			namelen == s->rk.dname_len &&
783 			query_dname_compare(name, s->rk.dname) == 0) {
784 			return s;
785 		}
786 	}
787 	return NULL;
788 }
789 
790 struct ub_packed_rrset_key* reply_find_rrset_section_ns(struct reply_info* rep,
791 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
792 {
793 	size_t i;
794 	for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
795 		struct ub_packed_rrset_key* s = rep->rrsets[i];
796 		if(ntohs(s->rk.type) == type &&
797 			ntohs(s->rk.rrset_class) == dclass &&
798 			namelen == s->rk.dname_len &&
799 			query_dname_compare(name, s->rk.dname) == 0) {
800 			return s;
801 		}
802 	}
803 	return NULL;
804 }
805 
806 struct ub_packed_rrset_key* reply_find_rrset(struct reply_info* rep,
807 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
808 {
809 	size_t i;
810 	for(i=0; i<rep->rrset_count; i++) {
811 		struct ub_packed_rrset_key* s = rep->rrsets[i];
812 		if(ntohs(s->rk.type) == type &&
813 			ntohs(s->rk.rrset_class) == dclass &&
814 			namelen == s->rk.dname_len &&
815 			query_dname_compare(name, s->rk.dname) == 0) {
816 			return s;
817 		}
818 	}
819 	return NULL;
820 }
821 
822 void
823 log_dns_msg(const char* str, struct query_info* qinfo, struct reply_info* rep)
824 {
825 	/* not particularly fast but flexible, make wireformat and print */
826 	sldns_buffer* buf = sldns_buffer_new(65535);
827 	struct regional* region = regional_create();
828 	if(!reply_info_encode(qinfo, rep, 0, rep->flags, buf, 0,
829 		region, 65535, 1, 0)) {
830 		log_info("%s: log_dns_msg: out of memory", str);
831 	} else {
832 		char* s = sldns_wire2str_pkt(sldns_buffer_begin(buf),
833 			sldns_buffer_limit(buf));
834 		if(!s) {
835 			log_info("%s: log_dns_msg: ldns tostr failed", str);
836 		} else {
837 			log_info("%s %s", str, s);
838 		}
839 		free(s);
840 	}
841 	sldns_buffer_free(buf);
842 	regional_destroy(region);
843 }
844 
845 void
846 log_reply_info(enum verbosity_value v, struct query_info *qinf,
847 	struct sockaddr_storage *addr, socklen_t addrlen, struct timeval dur,
848 	int cached, struct sldns_buffer *rmsg)
849 {
850 	char qname_buf[LDNS_MAX_DOMAINLEN+1];
851 	char clientip_buf[128];
852 	char rcode_buf[16];
853 	char type_buf[16];
854 	char class_buf[16];
855 	size_t pktlen;
856 	uint16_t rcode = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(rmsg, 2));
857 
858 	if(verbosity < v)
859 	  return;
860 
861 	sldns_wire2str_rcode_buf((int)rcode, rcode_buf, sizeof(rcode_buf));
862 	addr_to_str(addr, addrlen, clientip_buf, sizeof(clientip_buf));
863 	if(rcode == LDNS_RCODE_FORMERR)
864 	{
865 		if(LOG_TAG_QUERYREPLY)
866 			log_reply("%s - - - %s - - - ", clientip_buf, rcode_buf);
867 		else	log_info("%s - - - %s - - - ", clientip_buf, rcode_buf);
868 	} else {
869 		if(qinf->qname)
870 			dname_str(qinf->qname, qname_buf);
871 		else	snprintf(qname_buf, sizeof(qname_buf), "null");
872 		pktlen = sldns_buffer_limit(rmsg);
873 		sldns_wire2str_type_buf(qinf->qtype, type_buf, sizeof(type_buf));
874 		sldns_wire2str_class_buf(qinf->qclass, class_buf, sizeof(class_buf));
875 		if(LOG_TAG_QUERYREPLY)
876 		     log_reply("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d",
877 			clientip_buf, qname_buf, type_buf, class_buf,
878 			rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec, cached, (int)pktlen);
879 		else log_info("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d",
880 			clientip_buf, qname_buf, type_buf, class_buf,
881 			rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec, cached, (int)pktlen);
882 	}
883 }
884 
885 void
886 log_query_info(enum verbosity_value v, const char* str,
887 	struct query_info* qinf)
888 {
889 	log_nametypeclass(v, str, qinf->qname, qinf->qtype, qinf->qclass);
890 }
891 
892 int
893 reply_check_cname_chain(struct query_info* qinfo, struct reply_info* rep)
894 {
895 	/* check only answer section rrs for matching cname chain.
896 	 * the cache may return changed rdata, but owner names are untouched.*/
897 	size_t i;
898 	uint8_t* sname = qinfo->qname;
899 	size_t snamelen = qinfo->qname_len;
900 	for(i=0; i<rep->an_numrrsets; i++) {
901 		uint16_t t = ntohs(rep->rrsets[i]->rk.type);
902 		if(t == LDNS_RR_TYPE_DNAME)
903 			continue; /* skip dnames; note TTL 0 not cached */
904 		/* verify that owner matches current sname */
905 		if(query_dname_compare(sname, rep->rrsets[i]->rk.dname) != 0){
906 			/* cname chain broken */
907 			return 0;
908 		}
909 		/* if this is a cname; move on */
910 		if(t == LDNS_RR_TYPE_CNAME) {
911 			get_cname_target(rep->rrsets[i], &sname, &snamelen);
912 		}
913 	}
914 	return 1;
915 }
916 
917 int
918 reply_all_rrsets_secure(struct reply_info* rep)
919 {
920 	size_t i;
921 	for(i=0; i<rep->rrset_count; i++) {
922 		if( ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
923 			->security != sec_status_secure )
924 		return 0;
925 	}
926 	return 1;
927 }
928 
929 struct reply_info*
930 parse_reply_in_temp_region(sldns_buffer* pkt, struct regional* region,
931 	struct query_info* qi)
932 {
933 	struct reply_info* rep;
934 	struct msg_parse* msg;
935 	if(!(msg = regional_alloc(region, sizeof(*msg)))) {
936 		return NULL;
937 	}
938 	memset(msg, 0, sizeof(*msg));
939 	sldns_buffer_set_position(pkt, 0);
940 	if(parse_packet(pkt, msg, region) != 0){
941 		return 0;
942 	}
943 	if(!parse_create_msg(pkt, msg, NULL, qi, &rep, region)) {
944 		return 0;
945 	}
946 	return rep;
947 }
948 
949 int edns_opt_append(struct edns_data* edns, struct regional* region,
950 	uint16_t code, size_t len, uint8_t* data)
951 {
952 	struct edns_option** prevp;
953 	struct edns_option* opt;
954 
955 	/* allocate new element */
956 	opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
957 	if(!opt)
958 		return 0;
959 	opt->next = NULL;
960 	opt->opt_code = code;
961 	opt->opt_len = len;
962 	opt->opt_data = NULL;
963 	if(len > 0) {
964 		opt->opt_data = regional_alloc_init(region, data, len);
965 		if(!opt->opt_data)
966 			return 0;
967 	}
968 
969 	/* append at end of list */
970 	prevp = &edns->opt_list;
971 	while(*prevp != NULL)
972 		prevp = &((*prevp)->next);
973 	*prevp = opt;
974 	return 1;
975 }
976 
977 int edns_opt_list_append(struct edns_option** list, uint16_t code, size_t len,
978 	uint8_t* data, struct regional* region)
979 {
980 	struct edns_option** prevp;
981 	struct edns_option* opt;
982 
983 	/* allocate new element */
984 	opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
985 	if(!opt)
986 		return 0;
987 	opt->next = NULL;
988 	opt->opt_code = code;
989 	opt->opt_len = len;
990 	opt->opt_data = NULL;
991 	if(len > 0) {
992 		opt->opt_data = regional_alloc_init(region, data, len);
993 		if(!opt->opt_data)
994 			return 0;
995 	}
996 
997 	/* append at end of list */
998 	prevp = list;
999 	while(*prevp != NULL) {
1000 		prevp = &((*prevp)->next);
1001 	}
1002 	*prevp = opt;
1003 	return 1;
1004 }
1005 
1006 int edns_opt_list_remove(struct edns_option** list, uint16_t code)
1007 {
1008 	/* The list should already be allocated in a region. Freeing the
1009 	 * allocated space in a region is not possible. We just unlink the
1010 	 * required elements and they will be freed together with the region. */
1011 
1012 	struct edns_option* prev;
1013 	struct edns_option* curr;
1014 	if(!list || !(*list)) return 0;
1015 
1016 	/* Unlink and repoint if the element(s) are first in list */
1017 	while(list && *list && (*list)->opt_code == code) {
1018 		*list = (*list)->next;
1019 	}
1020 
1021 	if(!list || !(*list)) return 1;
1022 	/* Unlink elements and reattach the list */
1023 	prev = *list;
1024 	curr = (*list)->next;
1025 	while(curr != NULL) {
1026 		if(curr->opt_code == code) {
1027 			prev->next = curr->next;
1028 			curr = curr->next;
1029 		} else {
1030 			prev = curr;
1031 			curr = curr->next;
1032 		}
1033 	}
1034 	return 1;
1035 }
1036 
1037 static int inplace_cb_reply_call_generic(
1038     struct inplace_cb* callback_list, enum inplace_cb_list_type type,
1039 	struct query_info* qinfo, struct module_qstate* qstate,
1040 	struct reply_info* rep, int rcode, struct edns_data* edns,
1041 	struct comm_reply* repinfo, struct regional* region,
1042 	struct timeval* start_time)
1043 {
1044 	struct inplace_cb* cb;
1045 	struct edns_option* opt_list_out = NULL;
1046 #if defined(EXPORT_ALL_SYMBOLS)
1047 	(void)type; /* param not used when fptr_ok disabled */
1048 #endif
1049 	if(qstate)
1050 		opt_list_out = qstate->edns_opts_front_out;
1051 	for(cb=callback_list; cb; cb=cb->next) {
1052 		fptr_ok(fptr_whitelist_inplace_cb_reply_generic(
1053 			(inplace_cb_reply_func_type*)cb->cb, type));
1054 		(void)(*(inplace_cb_reply_func_type*)cb->cb)(qinfo, qstate, rep,
1055 			rcode, edns, &opt_list_out, repinfo, region, start_time, cb->id, cb->cb_arg);
1056 	}
1057 	edns->opt_list = opt_list_out;
1058 	return 1;
1059 }
1060 
1061 int inplace_cb_reply_call(struct module_env* env, struct query_info* qinfo,
1062 	struct module_qstate* qstate, struct reply_info* rep, int rcode,
1063 	struct edns_data* edns, struct comm_reply* repinfo, struct regional* region,
1064 	struct timeval* start_time)
1065 {
1066 	return inplace_cb_reply_call_generic(
1067 		env->inplace_cb_lists[inplace_cb_reply], inplace_cb_reply, qinfo,
1068 		qstate, rep, rcode, edns, repinfo, region, start_time);
1069 }
1070 
1071 int inplace_cb_reply_cache_call(struct module_env* env,
1072 	struct query_info* qinfo, struct module_qstate* qstate,
1073 	struct reply_info* rep, int rcode, struct edns_data* edns,
1074 	struct comm_reply* repinfo, struct regional* region,
1075 	struct timeval* start_time)
1076 {
1077 	return inplace_cb_reply_call_generic(
1078 		env->inplace_cb_lists[inplace_cb_reply_cache], inplace_cb_reply_cache,
1079 		qinfo, qstate, rep, rcode, edns, repinfo, region, start_time);
1080 }
1081 
1082 int inplace_cb_reply_local_call(struct module_env* env,
1083 	struct query_info* qinfo, struct module_qstate* qstate,
1084 	struct reply_info* rep, int rcode, struct edns_data* edns,
1085 	struct comm_reply* repinfo, struct regional* region,
1086 	struct timeval* start_time)
1087 {
1088 	return inplace_cb_reply_call_generic(
1089 		env->inplace_cb_lists[inplace_cb_reply_local], inplace_cb_reply_local,
1090 		qinfo, qstate, rep, rcode, edns, repinfo, region, start_time);
1091 }
1092 
1093 int inplace_cb_reply_servfail_call(struct module_env* env,
1094 	struct query_info* qinfo, struct module_qstate* qstate,
1095 	struct reply_info* rep, int rcode, struct edns_data* edns,
1096 	struct comm_reply* repinfo, struct regional* region,
1097 	struct timeval* start_time)
1098 {
1099 	/* We are going to servfail. Remove any potential edns options. */
1100 	if(qstate)
1101 		qstate->edns_opts_front_out = NULL;
1102 	return inplace_cb_reply_call_generic(
1103 		env->inplace_cb_lists[inplace_cb_reply_servfail],
1104 		inplace_cb_reply_servfail, qinfo, qstate, rep, rcode, edns, repinfo,
1105 		region, start_time);
1106 }
1107 
1108 int inplace_cb_query_call(struct module_env* env, struct query_info* qinfo,
1109 	uint16_t flags, struct sockaddr_storage* addr, socklen_t addrlen,
1110 	uint8_t* zone, size_t zonelen, struct module_qstate* qstate,
1111 	struct regional* region)
1112 {
1113 	struct inplace_cb* cb = env->inplace_cb_lists[inplace_cb_query];
1114 	for(; cb; cb=cb->next) {
1115 		fptr_ok(fptr_whitelist_inplace_cb_query(
1116 			(inplace_cb_query_func_type*)cb->cb));
1117 		(void)(*(inplace_cb_query_func_type*)cb->cb)(qinfo, flags,
1118 			qstate, addr, addrlen, zone, zonelen, region,
1119 			cb->id, cb->cb_arg);
1120 	}
1121 	return 1;
1122 }
1123 
1124 int inplace_cb_edns_back_parsed_call(struct module_env* env,
1125 	struct module_qstate* qstate)
1126 {
1127 	struct inplace_cb* cb =
1128 		env->inplace_cb_lists[inplace_cb_edns_back_parsed];
1129 	for(; cb; cb=cb->next) {
1130 		fptr_ok(fptr_whitelist_inplace_cb_edns_back_parsed(
1131 			(inplace_cb_edns_back_parsed_func_type*)cb->cb));
1132 		(void)(*(inplace_cb_edns_back_parsed_func_type*)cb->cb)(qstate,
1133 			cb->id, cb->cb_arg);
1134 	}
1135 	return 1;
1136 }
1137 
1138 int inplace_cb_query_response_call(struct module_env* env,
1139 	struct module_qstate* qstate, struct dns_msg* response) {
1140 	struct inplace_cb* cb =
1141 		env->inplace_cb_lists[inplace_cb_query_response];
1142 	for(; cb; cb=cb->next) {
1143 		fptr_ok(fptr_whitelist_inplace_cb_query_response(
1144 			(inplace_cb_query_response_func_type*)cb->cb));
1145 		(void)(*(inplace_cb_query_response_func_type*)cb->cb)(qstate,
1146 			response, cb->id, cb->cb_arg);
1147 	}
1148 	return 1;
1149 }
1150 
1151 struct edns_option* edns_opt_copy_region(struct edns_option* list,
1152         struct regional* region)
1153 {
1154 	struct edns_option* result = NULL, *cur = NULL, *s;
1155 	while(list) {
1156 		/* copy edns option structure */
1157 		s = regional_alloc_init(region, list, sizeof(*list));
1158 		if(!s) return NULL;
1159 		s->next = NULL;
1160 
1161 		/* copy option data */
1162 		if(s->opt_data) {
1163 			s->opt_data = regional_alloc_init(region, s->opt_data,
1164 				s->opt_len);
1165 			if(!s->opt_data)
1166 				return NULL;
1167 		}
1168 
1169 		/* link into list */
1170 		if(cur)
1171 			cur->next = s;
1172 		else	result = s;
1173 		cur = s;
1174 
1175 		/* examine next element */
1176 		list = list->next;
1177 	}
1178 	return result;
1179 }
1180 
1181 int edns_opt_compare(struct edns_option* p, struct edns_option* q)
1182 {
1183 	if(!p && !q) return 0;
1184 	if(!p) return -1;
1185 	if(!q) return 1;
1186 	log_assert(p && q);
1187 	if(p->opt_code != q->opt_code)
1188 		return (int)q->opt_code - (int)p->opt_code;
1189 	if(p->opt_len != q->opt_len)
1190 		return (int)q->opt_len - (int)p->opt_len;
1191 	if(p->opt_len != 0)
1192 		return memcmp(p->opt_data, q->opt_data, p->opt_len);
1193 	return 0;
1194 }
1195 
1196 int edns_opt_list_compare(struct edns_option* p, struct edns_option* q)
1197 {
1198 	int r;
1199 	while(p && q) {
1200 		r = edns_opt_compare(p, q);
1201 		if(r != 0)
1202 			return r;
1203 		p = p->next;
1204 		q = q->next;
1205 	}
1206 	if(p || q) {
1207 		/* uneven length lists */
1208 		if(p) return 1;
1209 		if(q) return -1;
1210 	}
1211 	return 0;
1212 }
1213 
1214 void edns_opt_list_free(struct edns_option* list)
1215 {
1216 	struct edns_option* n;
1217 	while(list) {
1218 		free(list->opt_data);
1219 		n = list->next;
1220 		free(list);
1221 		list = n;
1222 	}
1223 }
1224 
1225 struct edns_option* edns_opt_copy_alloc(struct edns_option* list)
1226 {
1227 	struct edns_option* result = NULL, *cur = NULL, *s;
1228 	while(list) {
1229 		/* copy edns option structure */
1230 		s = memdup(list, sizeof(*list));
1231 		if(!s) {
1232 			edns_opt_list_free(result);
1233 			return NULL;
1234 		}
1235 		s->next = NULL;
1236 
1237 		/* copy option data */
1238 		if(s->opt_data) {
1239 			s->opt_data = memdup(s->opt_data, s->opt_len);
1240 			if(!s->opt_data) {
1241 				free(s);
1242 				edns_opt_list_free(result);
1243 				return NULL;
1244 			}
1245 		}
1246 
1247 		/* link into list */
1248 		if(cur)
1249 			cur->next = s;
1250 		else	result = s;
1251 		cur = s;
1252 
1253 		/* examine next element */
1254 		list = list->next;
1255 	}
1256 	return result;
1257 }
1258 
1259 struct edns_option* edns_opt_list_find(struct edns_option* list, uint16_t code)
1260 {
1261 	struct edns_option* p;
1262 	for(p=list; p; p=p->next) {
1263 		if(p->opt_code == code)
1264 			return p;
1265 	}
1266 	return NULL;
1267 }
1268