xref: /freebsd/contrib/unbound/util/data/msgreply.c (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
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 
71 /** allocate qinfo, return 0 on error */
72 static int
73 parse_create_qinfo(sldns_buffer* pkt, struct msg_parse* msg,
74 	struct query_info* qinf, struct regional* region)
75 {
76 	if(msg->qname) {
77 		if(region)
78 			qinf->qname = (uint8_t*)regional_alloc(region,
79 				msg->qname_len);
80 		else	qinf->qname = (uint8_t*)malloc(msg->qname_len);
81 		if(!qinf->qname) return 0;
82 		dname_pkt_copy(pkt, qinf->qname, msg->qname);
83 	} else	qinf->qname = 0;
84 	qinf->qname_len = msg->qname_len;
85 	qinf->qtype = msg->qtype;
86 	qinf->qclass = msg->qclass;
87 	qinf->local_alias = NULL;
88 	return 1;
89 }
90 
91 /** constructor for replyinfo */
92 struct reply_info*
93 construct_reply_info_base(struct regional* region, uint16_t flags, size_t qd,
94 	time_t ttl, time_t prettl, time_t expttl, size_t an, size_t ns,
95 	size_t ar, size_t total, enum sec_status sec)
96 {
97 	struct reply_info* rep;
98 	/* rrset_count-1 because the first ref is part of the struct. */
99 	size_t s = sizeof(struct reply_info) - sizeof(struct rrset_ref) +
100 		sizeof(struct ub_packed_rrset_key*) * total;
101 	if(total >= RR_COUNT_MAX) return NULL; /* sanity check on numRRS*/
102 	if(region)
103 		rep = (struct reply_info*)regional_alloc(region, s);
104 	else	rep = (struct reply_info*)malloc(s +
105 			sizeof(struct rrset_ref) * (total));
106 	if(!rep)
107 		return NULL;
108 	rep->flags = flags;
109 	rep->qdcount = qd;
110 	rep->ttl = ttl;
111 	rep->prefetch_ttl = prettl;
112 	rep->serve_expired_ttl = expttl;
113 	rep->an_numrrsets = an;
114 	rep->ns_numrrsets = ns;
115 	rep->ar_numrrsets = ar;
116 	rep->rrset_count = total;
117 	rep->security = sec;
118 	rep->authoritative = 0;
119 	/* array starts after the refs */
120 	if(region)
121 		rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[0]);
122 	else	rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[total]);
123 	/* zero the arrays to assist cleanup in case of malloc failure */
124 	memset( rep->rrsets, 0, sizeof(struct ub_packed_rrset_key*) * total);
125 	if(!region)
126 		memset( &rep->ref[0], 0, sizeof(struct rrset_ref) * total);
127 	return rep;
128 }
129 
130 /** allocate replyinfo, return 0 on error */
131 static int
132 parse_create_repinfo(struct msg_parse* msg, struct reply_info** rep,
133 	struct regional* region)
134 {
135 	*rep = construct_reply_info_base(region, msg->flags, msg->qdcount, 0,
136 		0, 0, msg->an_rrsets, msg->ns_rrsets, msg->ar_rrsets,
137 		msg->rrset_count, sec_status_unchecked);
138 	if(!*rep)
139 		return 0;
140 	return 1;
141 }
142 
143 int
144 reply_info_alloc_rrset_keys(struct reply_info* rep, struct alloc_cache* alloc,
145 	struct regional* region)
146 {
147 	size_t i;
148 	for(i=0; i<rep->rrset_count; i++) {
149 		if(region) {
150 			rep->rrsets[i] = (struct ub_packed_rrset_key*)
151 				regional_alloc(region,
152 				sizeof(struct ub_packed_rrset_key));
153 			if(rep->rrsets[i]) {
154 				memset(rep->rrsets[i], 0,
155 					sizeof(struct ub_packed_rrset_key));
156 				rep->rrsets[i]->entry.key = rep->rrsets[i];
157 			}
158 		}
159 		else	rep->rrsets[i] = alloc_special_obtain(alloc);
160 		if(!rep->rrsets[i])
161 			return 0;
162 		rep->rrsets[i]->entry.data = NULL;
163 	}
164 	return 1;
165 }
166 
167 /** find the minimumttl in the rdata of SOA record */
168 static time_t
169 soa_find_minttl(struct rr_parse* rr)
170 {
171 	uint16_t rlen = sldns_read_uint16(rr->ttl_data+4);
172 	if(rlen < 20)
173 		return 0; /* rdata too small for SOA (dname, dname, 5*32bit) */
174 	/* minimum TTL is the last 32bit value in the rdata of the record */
175 	/* at position ttl_data + 4(ttl) + 2(rdatalen) + rdatalen - 4(timeval)*/
176 	return (time_t)sldns_read_uint32(rr->ttl_data+6+rlen-4);
177 }
178 
179 /** do the rdata copy */
180 static int
181 rdata_copy(sldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to,
182 	struct rr_parse* rr, time_t* rr_ttl, uint16_t type,
183 	sldns_pkt_section section)
184 {
185 	uint16_t pkt_len;
186 	const sldns_rr_descriptor* desc;
187 
188 	*rr_ttl = sldns_read_uint32(rr->ttl_data);
189 	/* RFC 2181 Section 8. if msb of ttl is set treat as if zero. */
190 	if(*rr_ttl & 0x80000000U)
191 		*rr_ttl = 0;
192 	if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) {
193 		/* negative response. see if TTL of SOA record larger than the
194 		 * minimum-ttl in the rdata of the SOA record */
195 		if(*rr_ttl > soa_find_minttl(rr))
196 			*rr_ttl = soa_find_minttl(rr);
197 		if(*rr_ttl > MAX_NEG_TTL)
198 			*rr_ttl = MAX_NEG_TTL;
199 	}
200 	if(*rr_ttl < MIN_TTL)
201 		*rr_ttl = MIN_TTL;
202 	if(*rr_ttl > MAX_TTL)
203 		*rr_ttl = MAX_TTL;
204 	if(*rr_ttl < data->ttl)
205 		data->ttl = *rr_ttl;
206 
207 	if(rr->outside_packet) {
208 		/* uncompressed already, only needs copy */
209 		memmove(to, rr->ttl_data+sizeof(uint32_t), rr->size);
210 		return 1;
211 	}
212 
213 	sldns_buffer_set_position(pkt, (size_t)
214 		(rr->ttl_data - sldns_buffer_begin(pkt) + sizeof(uint32_t)));
215 	/* insert decompressed size into rdata len stored in memory */
216 	/* -2 because rdatalen bytes are not included. */
217 	pkt_len = htons(rr->size - 2);
218 	memmove(to, &pkt_len, sizeof(uint16_t));
219 	to += 2;
220 	/* read packet rdata len */
221 	pkt_len = sldns_buffer_read_u16(pkt);
222 	if(sldns_buffer_remaining(pkt) < pkt_len)
223 		return 0;
224 	desc = sldns_rr_descript(type);
225 	if(pkt_len > 0 && desc && desc->_dname_count > 0) {
226 		int count = (int)desc->_dname_count;
227 		int rdf = 0;
228 		size_t len;
229 		size_t oldpos;
230 		/* decompress dnames. */
231 		while(pkt_len > 0 && count) {
232 			switch(desc->_wireformat[rdf]) {
233 			case LDNS_RDF_TYPE_DNAME:
234 				oldpos = sldns_buffer_position(pkt);
235 				dname_pkt_copy(pkt, to,
236 					sldns_buffer_current(pkt));
237 				to += pkt_dname_len(pkt);
238 				pkt_len -= sldns_buffer_position(pkt)-oldpos;
239 				count--;
240 				len = 0;
241 				break;
242 			case LDNS_RDF_TYPE_STR:
243 				len = sldns_buffer_current(pkt)[0] + 1;
244 				break;
245 			default:
246 				len = get_rdf_size(desc->_wireformat[rdf]);
247 				break;
248 			}
249 			if(len) {
250 				log_assert(len <= pkt_len);
251 				memmove(to, sldns_buffer_current(pkt), len);
252 				to += len;
253 				sldns_buffer_skip(pkt, (ssize_t)len);
254 				pkt_len -= len;
255 			}
256 			rdf++;
257 		}
258 	}
259 	/* copy remaining rdata */
260 	if(pkt_len >  0)
261 		memmove(to, sldns_buffer_current(pkt), pkt_len);
262 
263 	return 1;
264 }
265 
266 /** copy over the data into packed rrset */
267 static int
268 parse_rr_copy(sldns_buffer* pkt, struct rrset_parse* pset,
269 	struct packed_rrset_data* data)
270 {
271 	size_t i;
272 	struct rr_parse* rr = pset->rr_first;
273 	uint8_t* nextrdata;
274 	size_t total = pset->rr_count + pset->rrsig_count;
275 	data->ttl = MAX_TTL;
276 	data->count = pset->rr_count;
277 	data->rrsig_count = pset->rrsig_count;
278 	data->trust = rrset_trust_none;
279 	data->security = sec_status_unchecked;
280 	/* layout: struct - rr_len - rr_data - rr_ttl - rdata - rrsig */
281 	data->rr_len = (size_t*)((uint8_t*)data +
282 		sizeof(struct packed_rrset_data));
283 	data->rr_data = (uint8_t**)&(data->rr_len[total]);
284 	data->rr_ttl = (time_t*)&(data->rr_data[total]);
285 	nextrdata = (uint8_t*)&(data->rr_ttl[total]);
286 	for(i=0; i<data->count; i++) {
287 		data->rr_len[i] = rr->size;
288 		data->rr_data[i] = nextrdata;
289 		nextrdata += rr->size;
290 		if(!rdata_copy(pkt, data, data->rr_data[i], rr,
291 			&data->rr_ttl[i], pset->type, pset->section))
292 			return 0;
293 		rr = rr->next;
294 	}
295 	/* if rrsig, its rdata is at nextrdata */
296 	rr = pset->rrsig_first;
297 	for(i=data->count; i<total; i++) {
298 		data->rr_len[i] = rr->size;
299 		data->rr_data[i] = nextrdata;
300 		nextrdata += rr->size;
301 		if(!rdata_copy(pkt, data, data->rr_data[i], rr,
302 			&data->rr_ttl[i], LDNS_RR_TYPE_RRSIG, pset->section))
303 			return 0;
304 		rr = rr->next;
305 	}
306 	return 1;
307 }
308 
309 /** create rrset return 0 on failure */
310 static int
311 parse_create_rrset(sldns_buffer* pkt, struct rrset_parse* pset,
312 	struct packed_rrset_data** data, struct regional* region)
313 {
314 	/* allocate */
315 	size_t s;
316 	if(pset->rr_count > RR_COUNT_MAX || pset->rrsig_count > RR_COUNT_MAX ||
317 		pset->size > RR_COUNT_MAX)
318 		return 0; /* protect against integer overflow */
319 	s = sizeof(struct packed_rrset_data) +
320 		(pset->rr_count + pset->rrsig_count) *
321 		(sizeof(size_t)+sizeof(uint8_t*)+sizeof(time_t)) +
322 		pset->size;
323 	if(region)
324 		*data = regional_alloc(region, s);
325 	else	*data = malloc(s);
326 	if(!*data)
327 		return 0;
328 	/* copy & decompress */
329 	if(!parse_rr_copy(pkt, pset, *data)) {
330 		if(!region) free(*data);
331 		return 0;
332 	}
333 	return 1;
334 }
335 
336 /** get trust value for rrset */
337 static enum rrset_trust
338 get_rrset_trust(struct msg_parse* msg, struct rrset_parse* rrset)
339 {
340 	uint16_t AA = msg->flags & BIT_AA;
341 	if(rrset->section == LDNS_SECTION_ANSWER) {
342 		if(AA) {
343 			/* RFC2181 says remainder of CNAME chain is nonauth*/
344 			if(msg->rrset_first &&
345 				msg->rrset_first->section==LDNS_SECTION_ANSWER
346 				&& msg->rrset_first->type==LDNS_RR_TYPE_CNAME){
347 				if(rrset == msg->rrset_first)
348 					return rrset_trust_ans_AA;
349 				else 	return rrset_trust_ans_noAA;
350 			}
351 			if(msg->rrset_first &&
352 				msg->rrset_first->section==LDNS_SECTION_ANSWER
353 				&& msg->rrset_first->type==LDNS_RR_TYPE_DNAME){
354 				if(rrset == msg->rrset_first ||
355 				   rrset == msg->rrset_first->rrset_all_next)
356 					return rrset_trust_ans_AA;
357 				else 	return rrset_trust_ans_noAA;
358 			}
359 			return rrset_trust_ans_AA;
360 		}
361 		else	return rrset_trust_ans_noAA;
362 	} else if(rrset->section == LDNS_SECTION_AUTHORITY) {
363 		if(AA)	return rrset_trust_auth_AA;
364 		else	return rrset_trust_auth_noAA;
365 	} else {
366 		/* addit section */
367 		if(AA)	return rrset_trust_add_AA;
368 		else	return rrset_trust_add_noAA;
369 	}
370 	/* NOTREACHED */
371 	return rrset_trust_none;
372 }
373 
374 int
375 parse_copy_decompress_rrset(sldns_buffer* pkt, struct msg_parse* msg,
376 	struct rrset_parse *pset, struct regional* region,
377 	struct ub_packed_rrset_key* pk)
378 {
379 	struct packed_rrset_data* data;
380 	pk->rk.flags = pset->flags;
381 	pk->rk.dname_len = pset->dname_len;
382 	if(region)
383 		pk->rk.dname = (uint8_t*)regional_alloc(
384 			region, pset->dname_len);
385 	else	pk->rk.dname =
386 			(uint8_t*)malloc(pset->dname_len);
387 	if(!pk->rk.dname)
388 		return 0;
389 	/** copy & decompress dname */
390 	dname_pkt_copy(pkt, pk->rk.dname, pset->dname);
391 	/** copy over type and class */
392 	pk->rk.type = htons(pset->type);
393 	pk->rk.rrset_class = pset->rrset_class;
394 	/** read data part. */
395 	if(!parse_create_rrset(pkt, pset, &data, region))
396 		return 0;
397 	pk->entry.data = (void*)data;
398 	pk->entry.key = (void*)pk;
399 	pk->entry.hash = pset->hash;
400 	data->trust = get_rrset_trust(msg, pset);
401 	return 1;
402 }
403 
404 /**
405  * Copy and decompress rrs
406  * @param pkt: the packet for compression pointer resolution.
407  * @param msg: the parsed message
408  * @param rep: reply info to put rrs into.
409  * @param region: if not NULL, used for allocation.
410  * @return 0 on failure.
411  */
412 static int
413 parse_copy_decompress(sldns_buffer* pkt, struct msg_parse* msg,
414 	struct reply_info* rep, struct regional* region)
415 {
416 	size_t i;
417 	struct rrset_parse *pset = msg->rrset_first;
418 	struct packed_rrset_data* data;
419 	log_assert(rep);
420 	rep->ttl = MAX_TTL;
421 	rep->security = sec_status_unchecked;
422 	if(rep->rrset_count == 0)
423 		rep->ttl = NORR_TTL;
424 
425 	for(i=0; i<rep->rrset_count; i++) {
426 		if(!parse_copy_decompress_rrset(pkt, msg, pset, region,
427 			rep->rrsets[i]))
428 			return 0;
429 		data = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
430 		if(data->ttl < rep->ttl)
431 			rep->ttl = data->ttl;
432 
433 		pset = pset->rrset_all_next;
434 	}
435 	rep->prefetch_ttl = PREFETCH_TTL_CALC(rep->ttl);
436 	rep->serve_expired_ttl = rep->ttl + SERVE_EXPIRED_TTL;
437 	return 1;
438 }
439 
440 int
441 parse_create_msg(sldns_buffer* pkt, struct msg_parse* msg,
442 	struct alloc_cache* alloc, struct query_info* qinf,
443 	struct reply_info** rep, struct regional* region)
444 {
445 	log_assert(pkt && msg);
446 	if(!parse_create_qinfo(pkt, msg, qinf, region))
447 		return 0;
448 	if(!parse_create_repinfo(msg, rep, region))
449 		return 0;
450 	if(!reply_info_alloc_rrset_keys(*rep, alloc, region)) {
451 		if(!region) reply_info_parsedelete(*rep, alloc);
452 		return 0;
453 	}
454 	if(!parse_copy_decompress(pkt, msg, *rep, region)) {
455 		if(!region) reply_info_parsedelete(*rep, alloc);
456 		return 0;
457 	}
458 	return 1;
459 }
460 
461 int reply_info_parse(sldns_buffer* pkt, struct alloc_cache* alloc,
462         struct query_info* qinf, struct reply_info** rep,
463 	struct regional* region, struct edns_data* edns)
464 {
465 	/* use scratch pad region-allocator during parsing. */
466 	struct msg_parse* msg;
467 	int ret;
468 
469 	qinf->qname = NULL;
470 	qinf->local_alias = NULL;
471 	*rep = NULL;
472 	if(!(msg = regional_alloc(region, sizeof(*msg)))) {
473 		return LDNS_RCODE_SERVFAIL;
474 	}
475 	memset(msg, 0, sizeof(*msg));
476 
477 	sldns_buffer_set_position(pkt, 0);
478 	if((ret = parse_packet(pkt, msg, region)) != 0) {
479 		return ret;
480 	}
481 	if((ret = parse_extract_edns(msg, edns, region)) != 0)
482 		return ret;
483 
484 	/* parse OK, allocate return structures */
485 	/* this also performs dname decompression */
486 	if(!parse_create_msg(pkt, msg, alloc, qinf, rep, NULL)) {
487 		query_info_clear(qinf);
488 		reply_info_parsedelete(*rep, alloc);
489 		*rep = NULL;
490 		return LDNS_RCODE_SERVFAIL;
491 	}
492 	return 0;
493 }
494 
495 /** helper compare function to sort in lock order */
496 static int
497 reply_info_sortref_cmp(const void* a, const void* b)
498 {
499 	struct rrset_ref* x = (struct rrset_ref*)a;
500 	struct rrset_ref* y = (struct rrset_ref*)b;
501 	if(x->key < y->key) return -1;
502 	if(x->key > y->key) return 1;
503 	return 0;
504 }
505 
506 void
507 reply_info_sortref(struct reply_info* rep)
508 {
509 	qsort(&rep->ref[0], rep->rrset_count, sizeof(struct rrset_ref),
510 		reply_info_sortref_cmp);
511 }
512 
513 void
514 reply_info_set_ttls(struct reply_info* rep, time_t timenow)
515 {
516 	size_t i, j;
517 	rep->ttl += timenow;
518 	rep->prefetch_ttl += timenow;
519 	rep->serve_expired_ttl += timenow;
520 	for(i=0; i<rep->rrset_count; i++) {
521 		struct packed_rrset_data* data = (struct packed_rrset_data*)
522 			rep->ref[i].key->entry.data;
523 		if(i>0 && rep->ref[i].key == rep->ref[i-1].key)
524 			continue;
525 		data->ttl += timenow;
526 		for(j=0; j<data->count + data->rrsig_count; j++) {
527 			data->rr_ttl[j] += timenow;
528 		}
529 	}
530 }
531 
532 void
533 reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc)
534 {
535 	size_t i;
536 	if(!rep)
537 		return;
538 	/* no need to lock, since not shared in hashtables. */
539 	for(i=0; i<rep->rrset_count; i++) {
540 		ub_packed_rrset_parsedelete(rep->rrsets[i], alloc);
541 	}
542 	free(rep);
543 }
544 
545 int
546 query_info_parse(struct query_info* m, sldns_buffer* query)
547 {
548 	uint8_t* q = sldns_buffer_begin(query);
549 	/* minimum size: header + \0 + qtype + qclass */
550 	if(sldns_buffer_limit(query) < LDNS_HEADER_SIZE + 5)
551 		return 0;
552 	if((LDNS_OPCODE_WIRE(q) != LDNS_PACKET_QUERY && LDNS_OPCODE_WIRE(q) !=
553 		LDNS_PACKET_NOTIFY) || LDNS_QDCOUNT(q) != 1 ||
554 		sldns_buffer_position(query) != 0)
555 		return 0;
556 	sldns_buffer_skip(query, LDNS_HEADER_SIZE);
557 	m->qname = sldns_buffer_current(query);
558 	if((m->qname_len = query_dname_len(query)) == 0)
559 		return 0; /* parse error */
560 	if(sldns_buffer_remaining(query) < 4)
561 		return 0; /* need qtype, qclass */
562 	m->qtype = sldns_buffer_read_u16(query);
563 	m->qclass = sldns_buffer_read_u16(query);
564 	m->local_alias = NULL;
565 	return 1;
566 }
567 
568 /** tiny subroutine for msgreply_compare */
569 #define COMPARE_IT(x, y) \
570 	if( (x) < (y) ) return -1; \
571 	else if( (x) > (y) ) return +1; \
572 	log_assert( (x) == (y) );
573 
574 int
575 query_info_compare(void* m1, void* m2)
576 {
577 	struct query_info* msg1 = (struct query_info*)m1;
578 	struct query_info* msg2 = (struct query_info*)m2;
579 	int mc;
580 	/* from most different to least different for speed */
581 	COMPARE_IT(msg1->qtype, msg2->qtype);
582 	if((mc = query_dname_compare(msg1->qname, msg2->qname)) != 0)
583 		return mc;
584 	log_assert(msg1->qname_len == msg2->qname_len);
585 	COMPARE_IT(msg1->qclass, msg2->qclass);
586 	return 0;
587 #undef COMPARE_IT
588 }
589 
590 void
591 query_info_clear(struct query_info* m)
592 {
593 	free(m->qname);
594 	m->qname = NULL;
595 }
596 
597 size_t
598 msgreply_sizefunc(void* k, void* d)
599 {
600 	struct msgreply_entry* q = (struct msgreply_entry*)k;
601 	struct reply_info* r = (struct reply_info*)d;
602 	size_t s = sizeof(struct msgreply_entry) + sizeof(struct reply_info)
603 		+ q->key.qname_len + lock_get_mem(&q->entry.lock)
604 		- sizeof(struct rrset_ref);
605 	s += r->rrset_count * sizeof(struct rrset_ref);
606 	s += r->rrset_count * sizeof(struct ub_packed_rrset_key*);
607 	return s;
608 }
609 
610 void
611 query_entry_delete(void *k, void* ATTR_UNUSED(arg))
612 {
613 	struct msgreply_entry* q = (struct msgreply_entry*)k;
614 	lock_rw_destroy(&q->entry.lock);
615 	query_info_clear(&q->key);
616 	free(q);
617 }
618 
619 void
620 reply_info_delete(void* d, void* ATTR_UNUSED(arg))
621 {
622 	struct reply_info* r = (struct reply_info*)d;
623 	free(r);
624 }
625 
626 hashvalue_type
627 query_info_hash(struct query_info *q, uint16_t flags)
628 {
629 	hashvalue_type h = 0xab;
630 	h = hashlittle(&q->qtype, sizeof(q->qtype), h);
631 	if(q->qtype == LDNS_RR_TYPE_AAAA && (flags&BIT_CD))
632 		h++;
633 	h = hashlittle(&q->qclass, sizeof(q->qclass), h);
634 	h = dname_query_hash(q->qname, h);
635 	return h;
636 }
637 
638 struct msgreply_entry*
639 query_info_entrysetup(struct query_info* q, struct reply_info* r,
640 	hashvalue_type h)
641 {
642 	struct msgreply_entry* e = (struct msgreply_entry*)malloc(
643 		sizeof(struct msgreply_entry));
644 	if(!e) return NULL;
645 	memcpy(&e->key, q, sizeof(*q));
646 	e->entry.hash = h;
647 	e->entry.key = e;
648 	e->entry.data = r;
649 	lock_rw_init(&e->entry.lock);
650 	lock_protect(&e->entry.lock, &e->key.qname, sizeof(e->key.qname));
651 	lock_protect(&e->entry.lock, &e->key.qname_len, sizeof(e->key.qname_len));
652 	lock_protect(&e->entry.lock, &e->key.qtype, sizeof(e->key.qtype));
653 	lock_protect(&e->entry.lock, &e->key.qclass, sizeof(e->key.qclass));
654 	lock_protect(&e->entry.lock, &e->key.local_alias, sizeof(e->key.local_alias));
655 	lock_protect(&e->entry.lock, &e->entry.hash, sizeof(e->entry.hash));
656 	lock_protect(&e->entry.lock, &e->entry.key, sizeof(e->entry.key));
657 	lock_protect(&e->entry.lock, &e->entry.data, sizeof(e->entry.data));
658 	lock_protect(&e->entry.lock, e->key.qname, e->key.qname_len);
659 	q->qname = NULL;
660 	return e;
661 }
662 
663 /** copy rrsets from replyinfo to dest replyinfo */
664 static int
665 repinfo_copy_rrsets(struct reply_info* dest, struct reply_info* from,
666 	struct regional* region)
667 {
668 	size_t i, s;
669 	struct packed_rrset_data* fd, *dd;
670 	struct ub_packed_rrset_key* fk, *dk;
671 	for(i=0; i<dest->rrset_count; i++) {
672 		fk = from->rrsets[i];
673 		dk = dest->rrsets[i];
674 		fd = (struct packed_rrset_data*)fk->entry.data;
675 		dk->entry.hash = fk->entry.hash;
676 		dk->rk = fk->rk;
677 		if(region) {
678 			dk->id = fk->id;
679 			dk->rk.dname = (uint8_t*)regional_alloc_init(region,
680 				fk->rk.dname, fk->rk.dname_len);
681 		} else
682 			dk->rk.dname = (uint8_t*)memdup(fk->rk.dname,
683 				fk->rk.dname_len);
684 		if(!dk->rk.dname)
685 			return 0;
686 		s = packed_rrset_sizeof(fd);
687 		if(region)
688 			dd = (struct packed_rrset_data*)regional_alloc_init(
689 				region, fd, s);
690 		else	dd = (struct packed_rrset_data*)memdup(fd, s);
691 		if(!dd)
692 			return 0;
693 		packed_rrset_ptr_fixup(dd);
694 		dk->entry.data = (void*)dd;
695 	}
696 	return 1;
697 }
698 
699 struct reply_info*
700 reply_info_copy(struct reply_info* rep, struct alloc_cache* alloc,
701 	struct regional* region)
702 {
703 	struct reply_info* cp;
704 	cp = construct_reply_info_base(region, rep->flags, rep->qdcount,
705 		rep->ttl, rep->prefetch_ttl, rep->serve_expired_ttl,
706 		rep->an_numrrsets, rep->ns_numrrsets, rep->ar_numrrsets,
707 		rep->rrset_count, rep->security);
708 	if(!cp)
709 		return NULL;
710 	/* allocate ub_key structures special or not */
711 	if(!reply_info_alloc_rrset_keys(cp, alloc, region)) {
712 		if(!region)
713 			reply_info_parsedelete(cp, alloc);
714 		return NULL;
715 	}
716 	if(!repinfo_copy_rrsets(cp, rep, region)) {
717 		if(!region)
718 			reply_info_parsedelete(cp, alloc);
719 		return NULL;
720 	}
721 	return cp;
722 }
723 
724 uint8_t*
725 reply_find_final_cname_target(struct query_info* qinfo, struct reply_info* rep)
726 {
727 	uint8_t* sname = qinfo->qname;
728 	size_t snamelen = qinfo->qname_len;
729 	size_t i;
730 	for(i=0; i<rep->an_numrrsets; i++) {
731 		struct ub_packed_rrset_key* s = rep->rrsets[i];
732 		/* follow CNAME chain (if any) */
733 		if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
734 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
735 			snamelen == s->rk.dname_len &&
736 			query_dname_compare(sname, s->rk.dname) == 0) {
737 			get_cname_target(s, &sname, &snamelen);
738 		}
739 	}
740 	if(sname != qinfo->qname)
741 		return sname;
742 	return NULL;
743 }
744 
745 struct ub_packed_rrset_key*
746 reply_find_answer_rrset(struct query_info* qinfo, struct reply_info* rep)
747 {
748 	uint8_t* sname = qinfo->qname;
749 	size_t snamelen = qinfo->qname_len;
750 	size_t i;
751 	for(i=0; i<rep->an_numrrsets; i++) {
752 		struct ub_packed_rrset_key* s = rep->rrsets[i];
753 		/* first match type, for query of qtype cname */
754 		if(ntohs(s->rk.type) == qinfo->qtype &&
755 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
756 			snamelen == s->rk.dname_len &&
757 			query_dname_compare(sname, s->rk.dname) == 0) {
758 			return s;
759 		}
760 		/* follow CNAME chain (if any) */
761 		if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
762 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
763 			snamelen == s->rk.dname_len &&
764 			query_dname_compare(sname, s->rk.dname) == 0) {
765 			get_cname_target(s, &sname, &snamelen);
766 		}
767 	}
768 	return NULL;
769 }
770 
771 struct ub_packed_rrset_key* reply_find_rrset_section_an(struct reply_info* rep,
772 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
773 {
774 	size_t i;
775 	for(i=0; i<rep->an_numrrsets; i++) {
776 		struct ub_packed_rrset_key* s = rep->rrsets[i];
777 		if(ntohs(s->rk.type) == type &&
778 			ntohs(s->rk.rrset_class) == dclass &&
779 			namelen == s->rk.dname_len &&
780 			query_dname_compare(name, s->rk.dname) == 0) {
781 			return s;
782 		}
783 	}
784 	return NULL;
785 }
786 
787 struct ub_packed_rrset_key* reply_find_rrset_section_ns(struct reply_info* rep,
788 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
789 {
790 	size_t i;
791 	for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
792 		struct ub_packed_rrset_key* s = rep->rrsets[i];
793 		if(ntohs(s->rk.type) == type &&
794 			ntohs(s->rk.rrset_class) == dclass &&
795 			namelen == s->rk.dname_len &&
796 			query_dname_compare(name, s->rk.dname) == 0) {
797 			return s;
798 		}
799 	}
800 	return NULL;
801 }
802 
803 struct ub_packed_rrset_key* reply_find_rrset(struct reply_info* rep,
804 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
805 {
806 	size_t i;
807 	for(i=0; i<rep->rrset_count; i++) {
808 		struct ub_packed_rrset_key* s = rep->rrsets[i];
809 		if(ntohs(s->rk.type) == type &&
810 			ntohs(s->rk.rrset_class) == dclass &&
811 			namelen == s->rk.dname_len &&
812 			query_dname_compare(name, s->rk.dname) == 0) {
813 			return s;
814 		}
815 	}
816 	return NULL;
817 }
818 
819 void
820 log_dns_msg(const char* str, struct query_info* qinfo, struct reply_info* rep)
821 {
822 	/* not particularly fast but flexible, make wireformat and print */
823 	sldns_buffer* buf = sldns_buffer_new(65535);
824 	struct regional* region = regional_create();
825 	if(!reply_info_encode(qinfo, rep, 0, rep->flags, buf, 0,
826 		region, 65535, 1, 0)) {
827 		log_info("%s: log_dns_msg: out of memory", str);
828 	} else {
829 		char* s = sldns_wire2str_pkt(sldns_buffer_begin(buf),
830 			sldns_buffer_limit(buf));
831 		if(!s) {
832 			log_info("%s: log_dns_msg: ldns tostr failed", str);
833 		} else {
834 			log_info("%s %s", str, s);
835 		}
836 		free(s);
837 	}
838 	sldns_buffer_free(buf);
839 	regional_destroy(region);
840 }
841 
842 void
843 log_reply_info(enum verbosity_value v, struct query_info *qinf,
844 	struct sockaddr_storage *addr, socklen_t addrlen, struct timeval dur,
845 	int cached, struct sldns_buffer *rmsg)
846 {
847 	char qname_buf[LDNS_MAX_DOMAINLEN+1];
848 	char clientip_buf[128];
849 	char rcode_buf[16];
850 	char type_buf[16];
851 	char class_buf[16];
852 	size_t pktlen;
853 	uint16_t rcode = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(rmsg, 2));
854 
855 	if(verbosity < v)
856 	  return;
857 
858 	sldns_wire2str_rcode_buf((int)rcode, rcode_buf, sizeof(rcode_buf));
859 	addr_to_str(addr, addrlen, clientip_buf, sizeof(clientip_buf));
860 	if(rcode == LDNS_RCODE_FORMERR)
861 	{
862 		if(LOG_TAG_QUERYREPLY)
863 			log_reply("%s - - - %s - - - ", clientip_buf, rcode_buf);
864 		else	log_info("%s - - - %s - - - ", clientip_buf, rcode_buf);
865 	} else {
866 		if(qinf->qname)
867 			dname_str(qinf->qname, qname_buf);
868 		else	snprintf(qname_buf, sizeof(qname_buf), "null");
869 		pktlen = sldns_buffer_limit(rmsg);
870 		sldns_wire2str_type_buf(qinf->qtype, type_buf, sizeof(type_buf));
871 		sldns_wire2str_class_buf(qinf->qclass, class_buf, sizeof(class_buf));
872 		if(LOG_TAG_QUERYREPLY)
873 		     log_reply("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d",
874 			clientip_buf, qname_buf, type_buf, class_buf,
875 			rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec, cached, (int)pktlen);
876 		else log_info("%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 	}
880 }
881 
882 void
883 log_query_info(enum verbosity_value v, const char* str,
884 	struct query_info* qinf)
885 {
886 	log_nametypeclass(v, str, qinf->qname, qinf->qtype, qinf->qclass);
887 }
888 
889 int
890 reply_check_cname_chain(struct query_info* qinfo, struct reply_info* rep)
891 {
892 	/* check only answer section rrs for matching cname chain.
893 	 * the cache may return changed rdata, but owner names are untouched.*/
894 	size_t i;
895 	uint8_t* sname = qinfo->qname;
896 	size_t snamelen = qinfo->qname_len;
897 	for(i=0; i<rep->an_numrrsets; i++) {
898 		uint16_t t = ntohs(rep->rrsets[i]->rk.type);
899 		if(t == LDNS_RR_TYPE_DNAME)
900 			continue; /* skip dnames; note TTL 0 not cached */
901 		/* verify that owner matches current sname */
902 		if(query_dname_compare(sname, rep->rrsets[i]->rk.dname) != 0){
903 			/* cname chain broken */
904 			return 0;
905 		}
906 		/* if this is a cname; move on */
907 		if(t == LDNS_RR_TYPE_CNAME) {
908 			get_cname_target(rep->rrsets[i], &sname, &snamelen);
909 		}
910 	}
911 	return 1;
912 }
913 
914 int
915 reply_all_rrsets_secure(struct reply_info* rep)
916 {
917 	size_t i;
918 	for(i=0; i<rep->rrset_count; i++) {
919 		if( ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
920 			->security != sec_status_secure )
921 		return 0;
922 	}
923 	return 1;
924 }
925 
926 struct reply_info*
927 parse_reply_in_temp_region(sldns_buffer* pkt, struct regional* region,
928 	struct query_info* qi)
929 {
930 	struct reply_info* rep;
931 	struct msg_parse* msg;
932 	if(!(msg = regional_alloc(region, sizeof(*msg)))) {
933 		return NULL;
934 	}
935 	memset(msg, 0, sizeof(*msg));
936 	sldns_buffer_set_position(pkt, 0);
937 	if(parse_packet(pkt, msg, region) != 0){
938 		return 0;
939 	}
940 	if(!parse_create_msg(pkt, msg, NULL, qi, &rep, region)) {
941 		return 0;
942 	}
943 	return rep;
944 }
945 
946 int edns_opt_append(struct edns_data* edns, struct regional* region,
947 	uint16_t code, size_t len, uint8_t* data)
948 {
949 	struct edns_option** prevp;
950 	struct edns_option* opt;
951 
952 	/* allocate new element */
953 	opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
954 	if(!opt)
955 		return 0;
956 	opt->next = NULL;
957 	opt->opt_code = code;
958 	opt->opt_len = len;
959 	opt->opt_data = NULL;
960 	if(len > 0) {
961 		opt->opt_data = regional_alloc_init(region, data, len);
962 		if(!opt->opt_data)
963 			return 0;
964 	}
965 
966 	/* append at end of list */
967 	prevp = &edns->opt_list;
968 	while(*prevp != NULL)
969 		prevp = &((*prevp)->next);
970 	*prevp = opt;
971 	return 1;
972 }
973 
974 int edns_opt_list_append(struct edns_option** list, uint16_t code, size_t len,
975 	uint8_t* data, struct regional* region)
976 {
977 	struct edns_option** prevp;
978 	struct edns_option* opt;
979 
980 	/* allocate new element */
981 	opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
982 	if(!opt)
983 		return 0;
984 	opt->next = NULL;
985 	opt->opt_code = code;
986 	opt->opt_len = len;
987 	opt->opt_data = NULL;
988 	if(len > 0) {
989 		opt->opt_data = regional_alloc_init(region, data, len);
990 		if(!opt->opt_data)
991 			return 0;
992 	}
993 
994 	/* append at end of list */
995 	prevp = list;
996 	while(*prevp != NULL) {
997 		prevp = &((*prevp)->next);
998 	}
999 	*prevp = opt;
1000 	return 1;
1001 }
1002 
1003 int edns_opt_list_remove(struct edns_option** list, uint16_t code)
1004 {
1005 	/* The list should already be allocated in a region. Freeing the
1006 	 * allocated space in a region is not possible. We just unlink the
1007 	 * required elements and they will be freed together with the region. */
1008 
1009 	struct edns_option* prev;
1010 	struct edns_option* curr;
1011 	if(!list || !(*list)) return 0;
1012 
1013 	/* Unlink and repoint if the element(s) are first in list */
1014 	while(list && *list && (*list)->opt_code == code) {
1015 		*list = (*list)->next;
1016 	}
1017 
1018 	if(!list || !(*list)) return 1;
1019 	/* Unlink elements and reattach the list */
1020 	prev = *list;
1021 	curr = (*list)->next;
1022 	while(curr != NULL) {
1023 		if(curr->opt_code == code) {
1024 			prev->next = curr->next;
1025 			curr = curr->next;
1026 		} else {
1027 			prev = curr;
1028 			curr = curr->next;
1029 		}
1030 	}
1031 	return 1;
1032 }
1033 
1034 static int inplace_cb_reply_call_generic(
1035     struct inplace_cb* callback_list, enum inplace_cb_list_type type,
1036 	struct query_info* qinfo, struct module_qstate* qstate,
1037 	struct reply_info* rep, int rcode, struct edns_data* edns,
1038 	struct comm_reply* repinfo, struct regional* region)
1039 {
1040 	struct inplace_cb* cb;
1041 	struct edns_option* opt_list_out = NULL;
1042 #if defined(EXPORT_ALL_SYMBOLS)
1043 	(void)type; /* param not used when fptr_ok disabled */
1044 #endif
1045 	if(qstate)
1046 		opt_list_out = qstate->edns_opts_front_out;
1047 	for(cb=callback_list; cb; cb=cb->next) {
1048 		fptr_ok(fptr_whitelist_inplace_cb_reply_generic(
1049 			(inplace_cb_reply_func_type*)cb->cb, type));
1050 		(void)(*(inplace_cb_reply_func_type*)cb->cb)(qinfo, qstate, rep,
1051 			rcode, edns, &opt_list_out, repinfo, region, cb->id, cb->cb_arg);
1052 	}
1053 	edns->opt_list = opt_list_out;
1054 	return 1;
1055 }
1056 
1057 int inplace_cb_reply_call(struct module_env* env, struct query_info* qinfo,
1058 	struct module_qstate* qstate, struct reply_info* rep, int rcode,
1059 	struct edns_data* edns, struct comm_reply* repinfo, struct regional* region)
1060 {
1061 	return inplace_cb_reply_call_generic(
1062 		env->inplace_cb_lists[inplace_cb_reply], inplace_cb_reply, qinfo,
1063 		qstate, rep, rcode, edns, repinfo, region);
1064 }
1065 
1066 int inplace_cb_reply_cache_call(struct module_env* env,
1067 	struct query_info* qinfo, struct module_qstate* qstate,
1068 	struct reply_info* rep, int rcode, struct edns_data* edns,
1069 	struct comm_reply* repinfo, struct regional* region)
1070 {
1071 	return inplace_cb_reply_call_generic(
1072 		env->inplace_cb_lists[inplace_cb_reply_cache], inplace_cb_reply_cache,
1073 		qinfo, qstate, rep, rcode, edns, repinfo, region);
1074 }
1075 
1076 int inplace_cb_reply_local_call(struct module_env* env,
1077 	struct query_info* qinfo, struct module_qstate* qstate,
1078 	struct reply_info* rep, int rcode, struct edns_data* edns,
1079 	struct comm_reply* repinfo, struct regional* region)
1080 {
1081 	return inplace_cb_reply_call_generic(
1082 		env->inplace_cb_lists[inplace_cb_reply_local], inplace_cb_reply_local,
1083 		qinfo, qstate, rep, rcode, edns, repinfo, region);
1084 }
1085 
1086 int inplace_cb_reply_servfail_call(struct module_env* env,
1087 	struct query_info* qinfo, struct module_qstate* qstate,
1088 	struct reply_info* rep, int rcode, struct edns_data* edns,
1089 	struct comm_reply* repinfo, struct regional* region)
1090 {
1091 	/* We are going to servfail. Remove any potential edns options. */
1092 	if(qstate)
1093 		qstate->edns_opts_front_out = NULL;
1094 	return inplace_cb_reply_call_generic(
1095 		env->inplace_cb_lists[inplace_cb_reply_servfail],
1096 		inplace_cb_reply_servfail, qinfo, qstate, rep, rcode, edns, repinfo,
1097 		region);
1098 }
1099 
1100 int inplace_cb_query_call(struct module_env* env, struct query_info* qinfo,
1101 	uint16_t flags, struct sockaddr_storage* addr, socklen_t addrlen,
1102 	uint8_t* zone, size_t zonelen, struct module_qstate* qstate,
1103 	struct regional* region)
1104 {
1105 	struct inplace_cb* cb = env->inplace_cb_lists[inplace_cb_query];
1106 	for(; cb; cb=cb->next) {
1107 		fptr_ok(fptr_whitelist_inplace_cb_query(
1108 			(inplace_cb_query_func_type*)cb->cb));
1109 		(void)(*(inplace_cb_query_func_type*)cb->cb)(qinfo, flags,
1110 			qstate, addr, addrlen, zone, zonelen, region,
1111 			cb->id, cb->cb_arg);
1112 	}
1113 	return 1;
1114 }
1115 
1116 int inplace_cb_edns_back_parsed_call(struct module_env* env,
1117 	struct module_qstate* qstate)
1118 {
1119 	struct inplace_cb* cb =
1120 		env->inplace_cb_lists[inplace_cb_edns_back_parsed];
1121 	for(; cb; cb=cb->next) {
1122 		fptr_ok(fptr_whitelist_inplace_cb_edns_back_parsed(
1123 			(inplace_cb_edns_back_parsed_func_type*)cb->cb));
1124 		(void)(*(inplace_cb_edns_back_parsed_func_type*)cb->cb)(qstate,
1125 			cb->id, cb->cb_arg);
1126 	}
1127 	return 1;
1128 }
1129 
1130 int inplace_cb_query_response_call(struct module_env* env,
1131 	struct module_qstate* qstate, struct dns_msg* response) {
1132 	struct inplace_cb* cb =
1133 		env->inplace_cb_lists[inplace_cb_query_response];
1134 	for(; cb; cb=cb->next) {
1135 		fptr_ok(fptr_whitelist_inplace_cb_query_response(
1136 			(inplace_cb_query_response_func_type*)cb->cb));
1137 		(void)(*(inplace_cb_query_response_func_type*)cb->cb)(qstate,
1138 			response, cb->id, cb->cb_arg);
1139 	}
1140 	return 1;
1141 }
1142 
1143 struct edns_option* edns_opt_copy_region(struct edns_option* list,
1144         struct regional* region)
1145 {
1146 	struct edns_option* result = NULL, *cur = NULL, *s;
1147 	while(list) {
1148 		/* copy edns option structure */
1149 		s = regional_alloc_init(region, list, sizeof(*list));
1150 		if(!s) return NULL;
1151 		s->next = NULL;
1152 
1153 		/* copy option data */
1154 		if(s->opt_data) {
1155 			s->opt_data = regional_alloc_init(region, s->opt_data,
1156 				s->opt_len);
1157 			if(!s->opt_data)
1158 				return NULL;
1159 		}
1160 
1161 		/* link into list */
1162 		if(cur)
1163 			cur->next = s;
1164 		else	result = s;
1165 		cur = s;
1166 
1167 		/* examine next element */
1168 		list = list->next;
1169 	}
1170 	return result;
1171 }
1172 
1173 int edns_opt_compare(struct edns_option* p, struct edns_option* q)
1174 {
1175 	if(!p && !q) return 0;
1176 	if(!p) return -1;
1177 	if(!q) return 1;
1178 	log_assert(p && q);
1179 	if(p->opt_code != q->opt_code)
1180 		return (int)q->opt_code - (int)p->opt_code;
1181 	if(p->opt_len != q->opt_len)
1182 		return (int)q->opt_len - (int)p->opt_len;
1183 	if(p->opt_len != 0)
1184 		return memcmp(p->opt_data, q->opt_data, p->opt_len);
1185 	return 0;
1186 }
1187 
1188 int edns_opt_list_compare(struct edns_option* p, struct edns_option* q)
1189 {
1190 	int r;
1191 	while(p && q) {
1192 		r = edns_opt_compare(p, q);
1193 		if(r != 0)
1194 			return r;
1195 		p = p->next;
1196 		q = q->next;
1197 	}
1198 	if(p || q) {
1199 		/* uneven length lists */
1200 		if(p) return 1;
1201 		if(q) return -1;
1202 	}
1203 	return 0;
1204 }
1205 
1206 void edns_opt_list_free(struct edns_option* list)
1207 {
1208 	struct edns_option* n;
1209 	while(list) {
1210 		free(list->opt_data);
1211 		n = list->next;
1212 		free(list);
1213 		list = n;
1214 	}
1215 }
1216 
1217 struct edns_option* edns_opt_copy_alloc(struct edns_option* list)
1218 {
1219 	struct edns_option* result = NULL, *cur = NULL, *s;
1220 	while(list) {
1221 		/* copy edns option structure */
1222 		s = memdup(list, sizeof(*list));
1223 		if(!s) {
1224 			edns_opt_list_free(result);
1225 			return NULL;
1226 		}
1227 		s->next = NULL;
1228 
1229 		/* copy option data */
1230 		if(s->opt_data) {
1231 			s->opt_data = memdup(s->opt_data, s->opt_len);
1232 			if(!s->opt_data) {
1233 				free(s);
1234 				edns_opt_list_free(result);
1235 				return NULL;
1236 			}
1237 		}
1238 
1239 		/* link into list */
1240 		if(cur)
1241 			cur->next = s;
1242 		else	result = s;
1243 		cur = s;
1244 
1245 		/* examine next element */
1246 		list = list->next;
1247 	}
1248 	return result;
1249 }
1250 
1251 struct edns_option* edns_opt_list_find(struct edns_option* list, uint16_t code)
1252 {
1253 	struct edns_option* p;
1254 	for(p=list; p; p=p->next) {
1255 		if(p->opt_code == code)
1256 			return p;
1257 	}
1258 	return NULL;
1259 }
1260