xref: /freebsd/contrib/unbound/util/data/msgreply.c (revision 2f513db7)
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 /** Time to serve records after expiration */
65 time_t SERVE_EXPIRED_TTL = 0;
66 
67 /** allocate qinfo, return 0 on error */
68 static int
69 parse_create_qinfo(sldns_buffer* pkt, struct msg_parse* msg,
70 	struct query_info* qinf, struct regional* region)
71 {
72 	if(msg->qname) {
73 		if(region)
74 			qinf->qname = (uint8_t*)regional_alloc(region,
75 				msg->qname_len);
76 		else	qinf->qname = (uint8_t*)malloc(msg->qname_len);
77 		if(!qinf->qname) return 0;
78 		dname_pkt_copy(pkt, qinf->qname, msg->qname);
79 	} else	qinf->qname = 0;
80 	qinf->qname_len = msg->qname_len;
81 	qinf->qtype = msg->qtype;
82 	qinf->qclass = msg->qclass;
83 	qinf->local_alias = NULL;
84 	return 1;
85 }
86 
87 /** constructor for replyinfo */
88 struct reply_info*
89 construct_reply_info_base(struct regional* region, uint16_t flags, size_t qd,
90 	time_t ttl, time_t prettl, time_t expttl, size_t an, size_t ns,
91 	size_t ar, size_t total, enum sec_status sec)
92 {
93 	struct reply_info* rep;
94 	/* rrset_count-1 because the first ref is part of the struct. */
95 	size_t s = sizeof(struct reply_info) - sizeof(struct rrset_ref) +
96 		sizeof(struct ub_packed_rrset_key*) * total;
97 	if(total >= RR_COUNT_MAX) return NULL; /* sanity check on numRRS*/
98 	if(region)
99 		rep = (struct reply_info*)regional_alloc(region, s);
100 	else	rep = (struct reply_info*)malloc(s +
101 			sizeof(struct rrset_ref) * (total));
102 	if(!rep)
103 		return NULL;
104 	rep->flags = flags;
105 	rep->qdcount = qd;
106 	rep->ttl = ttl;
107 	rep->prefetch_ttl = prettl;
108 	rep->serve_expired_ttl = expttl;
109 	rep->an_numrrsets = an;
110 	rep->ns_numrrsets = ns;
111 	rep->ar_numrrsets = ar;
112 	rep->rrset_count = total;
113 	rep->security = sec;
114 	rep->authoritative = 0;
115 	/* array starts after the refs */
116 	if(region)
117 		rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[0]);
118 	else	rep->rrsets = (struct ub_packed_rrset_key**)&(rep->ref[total]);
119 	/* zero the arrays to assist cleanup in case of malloc failure */
120 	memset( rep->rrsets, 0, sizeof(struct ub_packed_rrset_key*) * total);
121 	if(!region)
122 		memset( &rep->ref[0], 0, sizeof(struct rrset_ref) * total);
123 	return rep;
124 }
125 
126 /** allocate replyinfo, return 0 on error */
127 static int
128 parse_create_repinfo(struct msg_parse* msg, struct reply_info** rep,
129 	struct regional* region)
130 {
131 	*rep = construct_reply_info_base(region, msg->flags, msg->qdcount, 0,
132 		0, 0, msg->an_rrsets, msg->ns_rrsets, msg->ar_rrsets,
133 		msg->rrset_count, sec_status_unchecked);
134 	if(!*rep)
135 		return 0;
136 	return 1;
137 }
138 
139 int
140 reply_info_alloc_rrset_keys(struct reply_info* rep, struct alloc_cache* alloc,
141 	struct regional* region)
142 {
143 	size_t i;
144 	for(i=0; i<rep->rrset_count; i++) {
145 		if(region) {
146 			rep->rrsets[i] = (struct ub_packed_rrset_key*)
147 				regional_alloc(region,
148 				sizeof(struct ub_packed_rrset_key));
149 			if(rep->rrsets[i]) {
150 				memset(rep->rrsets[i], 0,
151 					sizeof(struct ub_packed_rrset_key));
152 				rep->rrsets[i]->entry.key = rep->rrsets[i];
153 			}
154 		}
155 		else	rep->rrsets[i] = alloc_special_obtain(alloc);
156 		if(!rep->rrsets[i])
157 			return 0;
158 		rep->rrsets[i]->entry.data = NULL;
159 	}
160 	return 1;
161 }
162 
163 /** find the minimumttl in the rdata of SOA record */
164 static time_t
165 soa_find_minttl(struct rr_parse* rr)
166 {
167 	uint16_t rlen = sldns_read_uint16(rr->ttl_data+4);
168 	if(rlen < 20)
169 		return 0; /* rdata too small for SOA (dname, dname, 5*32bit) */
170 	/* minimum TTL is the last 32bit value in the rdata of the record */
171 	/* at position ttl_data + 4(ttl) + 2(rdatalen) + rdatalen - 4(timeval)*/
172 	return (time_t)sldns_read_uint32(rr->ttl_data+6+rlen-4);
173 }
174 
175 /** do the rdata copy */
176 static int
177 rdata_copy(sldns_buffer* pkt, struct packed_rrset_data* data, uint8_t* to,
178 	struct rr_parse* rr, time_t* rr_ttl, uint16_t type,
179 	sldns_pkt_section section)
180 {
181 	uint16_t pkt_len;
182 	const sldns_rr_descriptor* desc;
183 
184 	*rr_ttl = sldns_read_uint32(rr->ttl_data);
185 	/* RFC 2181 Section 8. if msb of ttl is set treat as if zero. */
186 	if(*rr_ttl & 0x80000000U)
187 		*rr_ttl = 0;
188 	if(type == LDNS_RR_TYPE_SOA && section == LDNS_SECTION_AUTHORITY) {
189 		/* negative response. see if TTL of SOA record larger than the
190 		 * minimum-ttl in the rdata of the SOA record */
191 		if(*rr_ttl > soa_find_minttl(rr))
192 			*rr_ttl = soa_find_minttl(rr);
193 		if(*rr_ttl > MAX_NEG_TTL)
194 			*rr_ttl = MAX_NEG_TTL;
195 	}
196 	if(*rr_ttl < MIN_TTL)
197 		*rr_ttl = MIN_TTL;
198 	if(*rr_ttl > MAX_TTL)
199 		*rr_ttl = MAX_TTL;
200 	if(*rr_ttl < data->ttl)
201 		data->ttl = *rr_ttl;
202 
203 	if(rr->outside_packet) {
204 		/* uncompressed already, only needs copy */
205 		memmove(to, rr->ttl_data+sizeof(uint32_t), rr->size);
206 		return 1;
207 	}
208 
209 	sldns_buffer_set_position(pkt, (size_t)
210 		(rr->ttl_data - sldns_buffer_begin(pkt) + sizeof(uint32_t)));
211 	/* insert decompressed size into rdata len stored in memory */
212 	/* -2 because rdatalen bytes are not included. */
213 	pkt_len = htons(rr->size - 2);
214 	memmove(to, &pkt_len, sizeof(uint16_t));
215 	to += 2;
216 	/* read packet rdata len */
217 	pkt_len = sldns_buffer_read_u16(pkt);
218 	if(sldns_buffer_remaining(pkt) < pkt_len)
219 		return 0;
220 	desc = sldns_rr_descript(type);
221 	if(pkt_len > 0 && desc && desc->_dname_count > 0) {
222 		int count = (int)desc->_dname_count;
223 		int rdf = 0;
224 		size_t len;
225 		size_t oldpos;
226 		/* decompress dnames. */
227 		while(pkt_len > 0 && count) {
228 			switch(desc->_wireformat[rdf]) {
229 			case LDNS_RDF_TYPE_DNAME:
230 				oldpos = sldns_buffer_position(pkt);
231 				dname_pkt_copy(pkt, to,
232 					sldns_buffer_current(pkt));
233 				to += pkt_dname_len(pkt);
234 				pkt_len -= sldns_buffer_position(pkt)-oldpos;
235 				count--;
236 				len = 0;
237 				break;
238 			case LDNS_RDF_TYPE_STR:
239 				len = sldns_buffer_current(pkt)[0] + 1;
240 				break;
241 			default:
242 				len = get_rdf_size(desc->_wireformat[rdf]);
243 				break;
244 			}
245 			if(len) {
246 				log_assert(len <= pkt_len);
247 				memmove(to, sldns_buffer_current(pkt), len);
248 				to += len;
249 				sldns_buffer_skip(pkt, (ssize_t)len);
250 				pkt_len -= len;
251 			}
252 			rdf++;
253 		}
254 	}
255 	/* copy remaining rdata */
256 	if(pkt_len >  0)
257 		memmove(to, sldns_buffer_current(pkt), pkt_len);
258 
259 	return 1;
260 }
261 
262 /** copy over the data into packed rrset */
263 static int
264 parse_rr_copy(sldns_buffer* pkt, struct rrset_parse* pset,
265 	struct packed_rrset_data* data)
266 {
267 	size_t i;
268 	struct rr_parse* rr = pset->rr_first;
269 	uint8_t* nextrdata;
270 	size_t total = pset->rr_count + pset->rrsig_count;
271 	data->ttl = MAX_TTL;
272 	data->count = pset->rr_count;
273 	data->rrsig_count = pset->rrsig_count;
274 	data->trust = rrset_trust_none;
275 	data->security = sec_status_unchecked;
276 	/* layout: struct - rr_len - rr_data - rr_ttl - rdata - rrsig */
277 	data->rr_len = (size_t*)((uint8_t*)data +
278 		sizeof(struct packed_rrset_data));
279 	data->rr_data = (uint8_t**)&(data->rr_len[total]);
280 	data->rr_ttl = (time_t*)&(data->rr_data[total]);
281 	nextrdata = (uint8_t*)&(data->rr_ttl[total]);
282 	for(i=0; i<data->count; i++) {
283 		data->rr_len[i] = rr->size;
284 		data->rr_data[i] = nextrdata;
285 		nextrdata += rr->size;
286 		if(!rdata_copy(pkt, data, data->rr_data[i], rr,
287 			&data->rr_ttl[i], pset->type, pset->section))
288 			return 0;
289 		rr = rr->next;
290 	}
291 	/* if rrsig, its rdata is at nextrdata */
292 	rr = pset->rrsig_first;
293 	for(i=data->count; i<total; i++) {
294 		data->rr_len[i] = rr->size;
295 		data->rr_data[i] = nextrdata;
296 		nextrdata += rr->size;
297 		if(!rdata_copy(pkt, data, data->rr_data[i], rr,
298 			&data->rr_ttl[i], LDNS_RR_TYPE_RRSIG, pset->section))
299 			return 0;
300 		rr = rr->next;
301 	}
302 	return 1;
303 }
304 
305 /** create rrset return 0 on failure */
306 static int
307 parse_create_rrset(sldns_buffer* pkt, struct rrset_parse* pset,
308 	struct packed_rrset_data** data, struct regional* region)
309 {
310 	/* allocate */
311 	size_t s;
312 	if(pset->rr_count > RR_COUNT_MAX || pset->rrsig_count > RR_COUNT_MAX ||
313 		pset->size > RR_COUNT_MAX)
314 		return 0; /* protect against integer overflow */
315 	s = sizeof(struct packed_rrset_data) +
316 		(pset->rr_count + pset->rrsig_count) *
317 		(sizeof(size_t)+sizeof(uint8_t*)+sizeof(time_t)) +
318 		pset->size;
319 	if(region)
320 		*data = regional_alloc(region, s);
321 	else	*data = malloc(s);
322 	if(!*data)
323 		return 0;
324 	/* copy & decompress */
325 	if(!parse_rr_copy(pkt, pset, *data)) {
326 		if(!region) free(*data);
327 		return 0;
328 	}
329 	return 1;
330 }
331 
332 /** get trust value for rrset */
333 static enum rrset_trust
334 get_rrset_trust(struct msg_parse* msg, struct rrset_parse* rrset)
335 {
336 	uint16_t AA = msg->flags & BIT_AA;
337 	if(rrset->section == LDNS_SECTION_ANSWER) {
338 		if(AA) {
339 			/* RFC2181 says remainder of CNAME chain is nonauth*/
340 			if(msg->rrset_first &&
341 				msg->rrset_first->section==LDNS_SECTION_ANSWER
342 				&& msg->rrset_first->type==LDNS_RR_TYPE_CNAME){
343 				if(rrset == msg->rrset_first)
344 					return rrset_trust_ans_AA;
345 				else 	return rrset_trust_ans_noAA;
346 			}
347 			if(msg->rrset_first &&
348 				msg->rrset_first->section==LDNS_SECTION_ANSWER
349 				&& msg->rrset_first->type==LDNS_RR_TYPE_DNAME){
350 				if(rrset == msg->rrset_first ||
351 				   rrset == msg->rrset_first->rrset_all_next)
352 					return rrset_trust_ans_AA;
353 				else 	return rrset_trust_ans_noAA;
354 			}
355 			return rrset_trust_ans_AA;
356 		}
357 		else	return rrset_trust_ans_noAA;
358 	} else if(rrset->section == LDNS_SECTION_AUTHORITY) {
359 		if(AA)	return rrset_trust_auth_AA;
360 		else	return rrset_trust_auth_noAA;
361 	} else {
362 		/* addit section */
363 		if(AA)	return rrset_trust_add_AA;
364 		else	return rrset_trust_add_noAA;
365 	}
366 	/* NOTREACHED */
367 	return rrset_trust_none;
368 }
369 
370 int
371 parse_copy_decompress_rrset(sldns_buffer* pkt, struct msg_parse* msg,
372 	struct rrset_parse *pset, struct regional* region,
373 	struct ub_packed_rrset_key* pk)
374 {
375 	struct packed_rrset_data* data;
376 	pk->rk.flags = pset->flags;
377 	pk->rk.dname_len = pset->dname_len;
378 	if(region)
379 		pk->rk.dname = (uint8_t*)regional_alloc(
380 			region, pset->dname_len);
381 	else	pk->rk.dname =
382 			(uint8_t*)malloc(pset->dname_len);
383 	if(!pk->rk.dname)
384 		return 0;
385 	/** copy & decompress dname */
386 	dname_pkt_copy(pkt, pk->rk.dname, pset->dname);
387 	/** copy over type and class */
388 	pk->rk.type = htons(pset->type);
389 	pk->rk.rrset_class = pset->rrset_class;
390 	/** read data part. */
391 	if(!parse_create_rrset(pkt, pset, &data, region))
392 		return 0;
393 	pk->entry.data = (void*)data;
394 	pk->entry.key = (void*)pk;
395 	pk->entry.hash = pset->hash;
396 	data->trust = get_rrset_trust(msg, pset);
397 	return 1;
398 }
399 
400 /**
401  * Copy and decompress rrs
402  * @param pkt: the packet for compression pointer resolution.
403  * @param msg: the parsed message
404  * @param rep: reply info to put rrs into.
405  * @param region: if not NULL, used for allocation.
406  * @return 0 on failure.
407  */
408 static int
409 parse_copy_decompress(sldns_buffer* pkt, struct msg_parse* msg,
410 	struct reply_info* rep, struct regional* region)
411 {
412 	size_t i;
413 	struct rrset_parse *pset = msg->rrset_first;
414 	struct packed_rrset_data* data;
415 	log_assert(rep);
416 	rep->ttl = MAX_TTL;
417 	rep->security = sec_status_unchecked;
418 	if(rep->rrset_count == 0)
419 		rep->ttl = NORR_TTL;
420 
421 	for(i=0; i<rep->rrset_count; i++) {
422 		if(!parse_copy_decompress_rrset(pkt, msg, pset, region,
423 			rep->rrsets[i]))
424 			return 0;
425 		data = (struct packed_rrset_data*)rep->rrsets[i]->entry.data;
426 		if(data->ttl < rep->ttl)
427 			rep->ttl = data->ttl;
428 
429 		pset = pset->rrset_all_next;
430 	}
431 	rep->prefetch_ttl = PREFETCH_TTL_CALC(rep->ttl);
432 	rep->serve_expired_ttl = rep->ttl + SERVE_EXPIRED_TTL;
433 	return 1;
434 }
435 
436 int
437 parse_create_msg(sldns_buffer* pkt, struct msg_parse* msg,
438 	struct alloc_cache* alloc, struct query_info* qinf,
439 	struct reply_info** rep, struct regional* region)
440 {
441 	log_assert(pkt && msg);
442 	if(!parse_create_qinfo(pkt, msg, qinf, region))
443 		return 0;
444 	if(!parse_create_repinfo(msg, rep, region))
445 		return 0;
446 	if(!reply_info_alloc_rrset_keys(*rep, alloc, region)) {
447 		if(!region) reply_info_parsedelete(*rep, alloc);
448 		return 0;
449 	}
450 	if(!parse_copy_decompress(pkt, msg, *rep, region)) {
451 		if(!region) reply_info_parsedelete(*rep, alloc);
452 		return 0;
453 	}
454 	return 1;
455 }
456 
457 int reply_info_parse(sldns_buffer* pkt, struct alloc_cache* alloc,
458         struct query_info* qinf, struct reply_info** rep,
459 	struct regional* region, struct edns_data* edns)
460 {
461 	/* use scratch pad region-allocator during parsing. */
462 	struct msg_parse* msg;
463 	int ret;
464 
465 	qinf->qname = NULL;
466 	qinf->local_alias = NULL;
467 	*rep = NULL;
468 	if(!(msg = regional_alloc(region, sizeof(*msg)))) {
469 		return LDNS_RCODE_SERVFAIL;
470 	}
471 	memset(msg, 0, sizeof(*msg));
472 
473 	sldns_buffer_set_position(pkt, 0);
474 	if((ret = parse_packet(pkt, msg, region)) != 0) {
475 		return ret;
476 	}
477 	if((ret = parse_extract_edns(msg, edns, region)) != 0)
478 		return ret;
479 
480 	/* parse OK, allocate return structures */
481 	/* this also performs dname decompression */
482 	if(!parse_create_msg(pkt, msg, alloc, qinf, rep, NULL)) {
483 		query_info_clear(qinf);
484 		reply_info_parsedelete(*rep, alloc);
485 		*rep = NULL;
486 		return LDNS_RCODE_SERVFAIL;
487 	}
488 	return 0;
489 }
490 
491 /** helper compare function to sort in lock order */
492 static int
493 reply_info_sortref_cmp(const void* a, const void* b)
494 {
495 	struct rrset_ref* x = (struct rrset_ref*)a;
496 	struct rrset_ref* y = (struct rrset_ref*)b;
497 	if(x->key < y->key) return -1;
498 	if(x->key > y->key) return 1;
499 	return 0;
500 }
501 
502 void
503 reply_info_sortref(struct reply_info* rep)
504 {
505 	qsort(&rep->ref[0], rep->rrset_count, sizeof(struct rrset_ref),
506 		reply_info_sortref_cmp);
507 }
508 
509 void
510 reply_info_set_ttls(struct reply_info* rep, time_t timenow)
511 {
512 	size_t i, j;
513 	rep->ttl += timenow;
514 	rep->prefetch_ttl += timenow;
515 	rep->serve_expired_ttl += timenow;
516 	for(i=0; i<rep->rrset_count; i++) {
517 		struct packed_rrset_data* data = (struct packed_rrset_data*)
518 			rep->ref[i].key->entry.data;
519 		if(i>0 && rep->ref[i].key == rep->ref[i-1].key)
520 			continue;
521 		data->ttl += timenow;
522 		for(j=0; j<data->count + data->rrsig_count; j++) {
523 			data->rr_ttl[j] += timenow;
524 		}
525 	}
526 }
527 
528 void
529 reply_info_parsedelete(struct reply_info* rep, struct alloc_cache* alloc)
530 {
531 	size_t i;
532 	if(!rep)
533 		return;
534 	/* no need to lock, since not shared in hashtables. */
535 	for(i=0; i<rep->rrset_count; i++) {
536 		ub_packed_rrset_parsedelete(rep->rrsets[i], alloc);
537 	}
538 	free(rep);
539 }
540 
541 int
542 query_info_parse(struct query_info* m, sldns_buffer* query)
543 {
544 	uint8_t* q = sldns_buffer_begin(query);
545 	/* minimum size: header + \0 + qtype + qclass */
546 	if(sldns_buffer_limit(query) < LDNS_HEADER_SIZE + 5)
547 		return 0;
548 	if((LDNS_OPCODE_WIRE(q) != LDNS_PACKET_QUERY && LDNS_OPCODE_WIRE(q) !=
549 		LDNS_PACKET_NOTIFY) || LDNS_QDCOUNT(q) != 1 ||
550 		sldns_buffer_position(query) != 0)
551 		return 0;
552 	sldns_buffer_skip(query, LDNS_HEADER_SIZE);
553 	m->qname = sldns_buffer_current(query);
554 	if((m->qname_len = query_dname_len(query)) == 0)
555 		return 0; /* parse error */
556 	if(sldns_buffer_remaining(query) < 4)
557 		return 0; /* need qtype, qclass */
558 	m->qtype = sldns_buffer_read_u16(query);
559 	m->qclass = sldns_buffer_read_u16(query);
560 	m->local_alias = NULL;
561 	return 1;
562 }
563 
564 /** tiny subroutine for msgreply_compare */
565 #define COMPARE_IT(x, y) \
566 	if( (x) < (y) ) return -1; \
567 	else if( (x) > (y) ) return +1; \
568 	log_assert( (x) == (y) );
569 
570 int
571 query_info_compare(void* m1, void* m2)
572 {
573 	struct query_info* msg1 = (struct query_info*)m1;
574 	struct query_info* msg2 = (struct query_info*)m2;
575 	int mc;
576 	/* from most different to least different for speed */
577 	COMPARE_IT(msg1->qtype, msg2->qtype);
578 	if((mc = query_dname_compare(msg1->qname, msg2->qname)) != 0)
579 		return mc;
580 	log_assert(msg1->qname_len == msg2->qname_len);
581 	COMPARE_IT(msg1->qclass, msg2->qclass);
582 	return 0;
583 #undef COMPARE_IT
584 }
585 
586 void
587 query_info_clear(struct query_info* m)
588 {
589 	free(m->qname);
590 	m->qname = NULL;
591 }
592 
593 size_t
594 msgreply_sizefunc(void* k, void* d)
595 {
596 	struct msgreply_entry* q = (struct msgreply_entry*)k;
597 	struct reply_info* r = (struct reply_info*)d;
598 	size_t s = sizeof(struct msgreply_entry) + sizeof(struct reply_info)
599 		+ q->key.qname_len + lock_get_mem(&q->entry.lock)
600 		- sizeof(struct rrset_ref);
601 	s += r->rrset_count * sizeof(struct rrset_ref);
602 	s += r->rrset_count * sizeof(struct ub_packed_rrset_key*);
603 	return s;
604 }
605 
606 void
607 query_entry_delete(void *k, void* ATTR_UNUSED(arg))
608 {
609 	struct msgreply_entry* q = (struct msgreply_entry*)k;
610 	lock_rw_destroy(&q->entry.lock);
611 	query_info_clear(&q->key);
612 	free(q);
613 }
614 
615 void
616 reply_info_delete(void* d, void* ATTR_UNUSED(arg))
617 {
618 	struct reply_info* r = (struct reply_info*)d;
619 	free(r);
620 }
621 
622 hashvalue_type
623 query_info_hash(struct query_info *q, uint16_t flags)
624 {
625 	hashvalue_type h = 0xab;
626 	h = hashlittle(&q->qtype, sizeof(q->qtype), h);
627 	if(q->qtype == LDNS_RR_TYPE_AAAA && (flags&BIT_CD))
628 		h++;
629 	h = hashlittle(&q->qclass, sizeof(q->qclass), h);
630 	h = dname_query_hash(q->qname, h);
631 	return h;
632 }
633 
634 struct msgreply_entry*
635 query_info_entrysetup(struct query_info* q, struct reply_info* r,
636 	hashvalue_type h)
637 {
638 	struct msgreply_entry* e = (struct msgreply_entry*)malloc(
639 		sizeof(struct msgreply_entry));
640 	if(!e) return NULL;
641 	memcpy(&e->key, q, sizeof(*q));
642 	e->entry.hash = h;
643 	e->entry.key = e;
644 	e->entry.data = r;
645 	lock_rw_init(&e->entry.lock);
646 	lock_protect(&e->entry.lock, &e->key.qname, sizeof(e->key.qname));
647 	lock_protect(&e->entry.lock, &e->key.qname_len, sizeof(e->key.qname_len));
648 	lock_protect(&e->entry.lock, &e->key.qtype, sizeof(e->key.qtype));
649 	lock_protect(&e->entry.lock, &e->key.qclass, sizeof(e->key.qclass));
650 	lock_protect(&e->entry.lock, &e->key.local_alias, sizeof(e->key.local_alias));
651 	lock_protect(&e->entry.lock, &e->entry.hash, sizeof(e->entry.hash));
652 	lock_protect(&e->entry.lock, &e->entry.key, sizeof(e->entry.key));
653 	lock_protect(&e->entry.lock, &e->entry.data, sizeof(e->entry.data));
654 	lock_protect(&e->entry.lock, e->key.qname, e->key.qname_len);
655 	q->qname = NULL;
656 	return e;
657 }
658 
659 /** copy rrsets from replyinfo to dest replyinfo */
660 static int
661 repinfo_copy_rrsets(struct reply_info* dest, struct reply_info* from,
662 	struct regional* region)
663 {
664 	size_t i, s;
665 	struct packed_rrset_data* fd, *dd;
666 	struct ub_packed_rrset_key* fk, *dk;
667 	for(i=0; i<dest->rrset_count; i++) {
668 		fk = from->rrsets[i];
669 		dk = dest->rrsets[i];
670 		fd = (struct packed_rrset_data*)fk->entry.data;
671 		dk->entry.hash = fk->entry.hash;
672 		dk->rk = fk->rk;
673 		if(region) {
674 			dk->id = fk->id;
675 			dk->rk.dname = (uint8_t*)regional_alloc_init(region,
676 				fk->rk.dname, fk->rk.dname_len);
677 		} else
678 			dk->rk.dname = (uint8_t*)memdup(fk->rk.dname,
679 				fk->rk.dname_len);
680 		if(!dk->rk.dname)
681 			return 0;
682 		s = packed_rrset_sizeof(fd);
683 		if(region)
684 			dd = (struct packed_rrset_data*)regional_alloc_init(
685 				region, fd, s);
686 		else	dd = (struct packed_rrset_data*)memdup(fd, s);
687 		if(!dd)
688 			return 0;
689 		packed_rrset_ptr_fixup(dd);
690 		dk->entry.data = (void*)dd;
691 	}
692 	return 1;
693 }
694 
695 struct reply_info*
696 reply_info_copy(struct reply_info* rep, struct alloc_cache* alloc,
697 	struct regional* region)
698 {
699 	struct reply_info* cp;
700 	cp = construct_reply_info_base(region, rep->flags, rep->qdcount,
701 		rep->ttl, rep->prefetch_ttl, rep->serve_expired_ttl,
702 		rep->an_numrrsets, rep->ns_numrrsets, rep->ar_numrrsets,
703 		rep->rrset_count, rep->security);
704 	if(!cp)
705 		return NULL;
706 	/* allocate ub_key structures special or not */
707 	if(!reply_info_alloc_rrset_keys(cp, alloc, region)) {
708 		if(!region)
709 			reply_info_parsedelete(cp, alloc);
710 		return NULL;
711 	}
712 	if(!repinfo_copy_rrsets(cp, rep, region)) {
713 		if(!region)
714 			reply_info_parsedelete(cp, alloc);
715 		return NULL;
716 	}
717 	return cp;
718 }
719 
720 uint8_t*
721 reply_find_final_cname_target(struct query_info* qinfo, struct reply_info* rep)
722 {
723 	uint8_t* sname = qinfo->qname;
724 	size_t snamelen = qinfo->qname_len;
725 	size_t i;
726 	for(i=0; i<rep->an_numrrsets; i++) {
727 		struct ub_packed_rrset_key* s = rep->rrsets[i];
728 		/* follow CNAME chain (if any) */
729 		if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
730 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
731 			snamelen == s->rk.dname_len &&
732 			query_dname_compare(sname, s->rk.dname) == 0) {
733 			get_cname_target(s, &sname, &snamelen);
734 		}
735 	}
736 	if(sname != qinfo->qname)
737 		return sname;
738 	return NULL;
739 }
740 
741 struct ub_packed_rrset_key*
742 reply_find_answer_rrset(struct query_info* qinfo, struct reply_info* rep)
743 {
744 	uint8_t* sname = qinfo->qname;
745 	size_t snamelen = qinfo->qname_len;
746 	size_t i;
747 	for(i=0; i<rep->an_numrrsets; i++) {
748 		struct ub_packed_rrset_key* s = rep->rrsets[i];
749 		/* first match type, for query of qtype cname */
750 		if(ntohs(s->rk.type) == qinfo->qtype &&
751 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
752 			snamelen == s->rk.dname_len &&
753 			query_dname_compare(sname, s->rk.dname) == 0) {
754 			return s;
755 		}
756 		/* follow CNAME chain (if any) */
757 		if(ntohs(s->rk.type) == LDNS_RR_TYPE_CNAME &&
758 			ntohs(s->rk.rrset_class) == qinfo->qclass &&
759 			snamelen == s->rk.dname_len &&
760 			query_dname_compare(sname, s->rk.dname) == 0) {
761 			get_cname_target(s, &sname, &snamelen);
762 		}
763 	}
764 	return NULL;
765 }
766 
767 struct ub_packed_rrset_key* reply_find_rrset_section_an(struct reply_info* rep,
768 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
769 {
770 	size_t i;
771 	for(i=0; i<rep->an_numrrsets; i++) {
772 		struct ub_packed_rrset_key* s = rep->rrsets[i];
773 		if(ntohs(s->rk.type) == type &&
774 			ntohs(s->rk.rrset_class) == dclass &&
775 			namelen == s->rk.dname_len &&
776 			query_dname_compare(name, s->rk.dname) == 0) {
777 			return s;
778 		}
779 	}
780 	return NULL;
781 }
782 
783 struct ub_packed_rrset_key* reply_find_rrset_section_ns(struct reply_info* rep,
784 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
785 {
786 	size_t i;
787 	for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
788 		struct ub_packed_rrset_key* s = rep->rrsets[i];
789 		if(ntohs(s->rk.type) == type &&
790 			ntohs(s->rk.rrset_class) == dclass &&
791 			namelen == s->rk.dname_len &&
792 			query_dname_compare(name, s->rk.dname) == 0) {
793 			return s;
794 		}
795 	}
796 	return NULL;
797 }
798 
799 struct ub_packed_rrset_key* reply_find_rrset(struct reply_info* rep,
800 	uint8_t* name, size_t namelen, uint16_t type, uint16_t dclass)
801 {
802 	size_t i;
803 	for(i=0; i<rep->rrset_count; i++) {
804 		struct ub_packed_rrset_key* s = rep->rrsets[i];
805 		if(ntohs(s->rk.type) == type &&
806 			ntohs(s->rk.rrset_class) == dclass &&
807 			namelen == s->rk.dname_len &&
808 			query_dname_compare(name, s->rk.dname) == 0) {
809 			return s;
810 		}
811 	}
812 	return NULL;
813 }
814 
815 void
816 log_dns_msg(const char* str, struct query_info* qinfo, struct reply_info* rep)
817 {
818 	/* not particularly fast but flexible, make wireformat and print */
819 	sldns_buffer* buf = sldns_buffer_new(65535);
820 	struct regional* region = regional_create();
821 	if(!reply_info_encode(qinfo, rep, 0, rep->flags, buf, 0,
822 		region, 65535, 1, 0)) {
823 		log_info("%s: log_dns_msg: out of memory", str);
824 	} else {
825 		char* s = sldns_wire2str_pkt(sldns_buffer_begin(buf),
826 			sldns_buffer_limit(buf));
827 		if(!s) {
828 			log_info("%s: log_dns_msg: ldns tostr failed", str);
829 		} else {
830 			log_info("%s %s", str, s);
831 		}
832 		free(s);
833 	}
834 	sldns_buffer_free(buf);
835 	regional_destroy(region);
836 }
837 
838 void
839 log_reply_info(enum verbosity_value v, struct query_info *qinf,
840 	struct sockaddr_storage *addr, socklen_t addrlen, struct timeval dur,
841 	int cached, struct sldns_buffer *rmsg)
842 {
843 	char qname_buf[LDNS_MAX_DOMAINLEN+1];
844 	char clientip_buf[128];
845 	char rcode_buf[16];
846 	char type_buf[16];
847 	char class_buf[16];
848 	size_t pktlen;
849 	uint16_t rcode = FLAGS_GET_RCODE(sldns_buffer_read_u16_at(rmsg, 2));
850 
851 	if(verbosity < v)
852 	  return;
853 
854 	sldns_wire2str_rcode_buf((int)rcode, rcode_buf, sizeof(rcode_buf));
855 	addr_to_str(addr, addrlen, clientip_buf, sizeof(clientip_buf));
856 	if(rcode == LDNS_RCODE_FORMERR)
857 	{
858 		if(LOG_TAG_QUERYREPLY)
859 			log_reply("%s - - - %s - - - ", clientip_buf, rcode_buf);
860 		else	log_info("%s - - - %s - - - ", clientip_buf, rcode_buf);
861 	} else {
862 		if(qinf->qname)
863 			dname_str(qinf->qname, qname_buf);
864 		else	snprintf(qname_buf, sizeof(qname_buf), "null");
865 		pktlen = sldns_buffer_limit(rmsg);
866 		sldns_wire2str_type_buf(qinf->qtype, type_buf, sizeof(type_buf));
867 		sldns_wire2str_class_buf(qinf->qclass, class_buf, sizeof(class_buf));
868 		if(LOG_TAG_QUERYREPLY)
869 		     log_reply("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d",
870 			clientip_buf, qname_buf, type_buf, class_buf,
871 			rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec, cached, (int)pktlen);
872 		else log_info("%s %s %s %s %s " ARG_LL "d.%6.6d %d %d",
873 			clientip_buf, qname_buf, type_buf, class_buf,
874 			rcode_buf, (long long)dur.tv_sec, (int)dur.tv_usec, cached, (int)pktlen);
875 	}
876 }
877 
878 void
879 log_query_info(enum verbosity_value v, const char* str,
880 	struct query_info* qinf)
881 {
882 	log_nametypeclass(v, str, qinf->qname, qinf->qtype, qinf->qclass);
883 }
884 
885 int
886 reply_check_cname_chain(struct query_info* qinfo, struct reply_info* rep)
887 {
888 	/* check only answer section rrs for matching cname chain.
889 	 * the cache may return changed rdata, but owner names are untouched.*/
890 	size_t i;
891 	uint8_t* sname = qinfo->qname;
892 	size_t snamelen = qinfo->qname_len;
893 	for(i=0; i<rep->an_numrrsets; i++) {
894 		uint16_t t = ntohs(rep->rrsets[i]->rk.type);
895 		if(t == LDNS_RR_TYPE_DNAME)
896 			continue; /* skip dnames; note TTL 0 not cached */
897 		/* verify that owner matches current sname */
898 		if(query_dname_compare(sname, rep->rrsets[i]->rk.dname) != 0){
899 			/* cname chain broken */
900 			return 0;
901 		}
902 		/* if this is a cname; move on */
903 		if(t == LDNS_RR_TYPE_CNAME) {
904 			get_cname_target(rep->rrsets[i], &sname, &snamelen);
905 		}
906 	}
907 	return 1;
908 }
909 
910 int
911 reply_all_rrsets_secure(struct reply_info* rep)
912 {
913 	size_t i;
914 	for(i=0; i<rep->rrset_count; i++) {
915 		if( ((struct packed_rrset_data*)rep->rrsets[i]->entry.data)
916 			->security != sec_status_secure )
917 		return 0;
918 	}
919 	return 1;
920 }
921 
922 struct reply_info*
923 parse_reply_in_temp_region(sldns_buffer* pkt, struct regional* region,
924 	struct query_info* qi)
925 {
926 	struct reply_info* rep;
927 	struct msg_parse* msg;
928 	if(!(msg = regional_alloc(region, sizeof(*msg)))) {
929 		return NULL;
930 	}
931 	memset(msg, 0, sizeof(*msg));
932 	sldns_buffer_set_position(pkt, 0);
933 	if(parse_packet(pkt, msg, region) != 0){
934 		return 0;
935 	}
936 	if(!parse_create_msg(pkt, msg, NULL, qi, &rep, region)) {
937 		return 0;
938 	}
939 	return rep;
940 }
941 
942 int edns_opt_append(struct edns_data* edns, struct regional* region,
943 	uint16_t code, size_t len, uint8_t* data)
944 {
945 	struct edns_option** prevp;
946 	struct edns_option* opt;
947 
948 	/* allocate new element */
949 	opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
950 	if(!opt)
951 		return 0;
952 	opt->next = NULL;
953 	opt->opt_code = code;
954 	opt->opt_len = len;
955 	opt->opt_data = NULL;
956 	if(len > 0) {
957 		opt->opt_data = regional_alloc_init(region, data, len);
958 		if(!opt->opt_data)
959 			return 0;
960 	}
961 
962 	/* append at end of list */
963 	prevp = &edns->opt_list;
964 	while(*prevp != NULL)
965 		prevp = &((*prevp)->next);
966 	*prevp = opt;
967 	return 1;
968 }
969 
970 int edns_opt_list_append(struct edns_option** list, uint16_t code, size_t len,
971 	uint8_t* data, struct regional* region)
972 {
973 	struct edns_option** prevp;
974 	struct edns_option* opt;
975 
976 	/* allocate new element */
977 	opt = (struct edns_option*)regional_alloc(region, sizeof(*opt));
978 	if(!opt)
979 		return 0;
980 	opt->next = NULL;
981 	opt->opt_code = code;
982 	opt->opt_len = len;
983 	opt->opt_data = NULL;
984 	if(len > 0) {
985 		opt->opt_data = regional_alloc_init(region, data, len);
986 		if(!opt->opt_data)
987 			return 0;
988 	}
989 
990 	/* append at end of list */
991 	prevp = list;
992 	while(*prevp != NULL) {
993 		prevp = &((*prevp)->next);
994 	}
995 	*prevp = opt;
996 	return 1;
997 }
998 
999 int edns_opt_list_remove(struct edns_option** list, uint16_t code)
1000 {
1001 	/* The list should already be allocated in a region. Freeing the
1002 	 * allocated space in a region is not possible. We just unlink the
1003 	 * required elements and they will be freed together with the region. */
1004 
1005 	struct edns_option* prev;
1006 	struct edns_option* curr;
1007 	if(!list || !(*list)) return 0;
1008 
1009 	/* Unlink and repoint if the element(s) are first in list */
1010 	while(list && *list && (*list)->opt_code == code) {
1011 		*list = (*list)->next;
1012 	}
1013 
1014 	if(!list || !(*list)) return 1;
1015 	/* Unlink elements and reattach the list */
1016 	prev = *list;
1017 	curr = (*list)->next;
1018 	while(curr != NULL) {
1019 		if(curr->opt_code == code) {
1020 			prev->next = curr->next;
1021 			curr = curr->next;
1022 		} else {
1023 			prev = curr;
1024 			curr = curr->next;
1025 		}
1026 	}
1027 	return 1;
1028 }
1029 
1030 static int inplace_cb_reply_call_generic(
1031     struct inplace_cb* callback_list, enum inplace_cb_list_type type,
1032 	struct query_info* qinfo, struct module_qstate* qstate,
1033 	struct reply_info* rep, int rcode, struct edns_data* edns,
1034 	struct comm_reply* repinfo, struct regional* region)
1035 {
1036 	struct inplace_cb* cb;
1037 	struct edns_option* opt_list_out = NULL;
1038 #if defined(EXPORT_ALL_SYMBOLS)
1039 	(void)type; /* param not used when fptr_ok disabled */
1040 #endif
1041 	if(qstate)
1042 		opt_list_out = qstate->edns_opts_front_out;
1043 	for(cb=callback_list; cb; cb=cb->next) {
1044 		fptr_ok(fptr_whitelist_inplace_cb_reply_generic(
1045 			(inplace_cb_reply_func_type*)cb->cb, type));
1046 		(void)(*(inplace_cb_reply_func_type*)cb->cb)(qinfo, qstate, rep,
1047 			rcode, edns, &opt_list_out, repinfo, region, cb->id, cb->cb_arg);
1048 	}
1049 	edns->opt_list = opt_list_out;
1050 	return 1;
1051 }
1052 
1053 int inplace_cb_reply_call(struct module_env* env, struct query_info* qinfo,
1054 	struct module_qstate* qstate, struct reply_info* rep, int rcode,
1055 	struct edns_data* edns, struct comm_reply* repinfo, struct regional* region)
1056 {
1057 	return inplace_cb_reply_call_generic(
1058 		env->inplace_cb_lists[inplace_cb_reply], inplace_cb_reply, qinfo,
1059 		qstate, rep, rcode, edns, repinfo, region);
1060 }
1061 
1062 int inplace_cb_reply_cache_call(struct module_env* env,
1063 	struct query_info* qinfo, struct module_qstate* qstate,
1064 	struct reply_info* rep, int rcode, struct edns_data* edns,
1065 	struct comm_reply* repinfo, struct regional* region)
1066 {
1067 	return inplace_cb_reply_call_generic(
1068 		env->inplace_cb_lists[inplace_cb_reply_cache], inplace_cb_reply_cache,
1069 		qinfo, qstate, rep, rcode, edns, repinfo, region);
1070 }
1071 
1072 int inplace_cb_reply_local_call(struct module_env* env,
1073 	struct query_info* qinfo, struct module_qstate* qstate,
1074 	struct reply_info* rep, int rcode, struct edns_data* edns,
1075 	struct comm_reply* repinfo, struct regional* region)
1076 {
1077 	return inplace_cb_reply_call_generic(
1078 		env->inplace_cb_lists[inplace_cb_reply_local], inplace_cb_reply_local,
1079 		qinfo, qstate, rep, rcode, edns, repinfo, region);
1080 }
1081 
1082 int inplace_cb_reply_servfail_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 {
1087 	/* We are going to servfail. Remove any potential edns options. */
1088 	if(qstate)
1089 		qstate->edns_opts_front_out = NULL;
1090 	return inplace_cb_reply_call_generic(
1091 		env->inplace_cb_lists[inplace_cb_reply_servfail],
1092 		inplace_cb_reply_servfail, qinfo, qstate, rep, rcode, edns, repinfo,
1093 		region);
1094 }
1095 
1096 int inplace_cb_query_call(struct module_env* env, struct query_info* qinfo,
1097 	uint16_t flags, struct sockaddr_storage* addr, socklen_t addrlen,
1098 	uint8_t* zone, size_t zonelen, struct module_qstate* qstate,
1099 	struct regional* region)
1100 {
1101 	struct inplace_cb* cb = env->inplace_cb_lists[inplace_cb_query];
1102 	for(; cb; cb=cb->next) {
1103 		fptr_ok(fptr_whitelist_inplace_cb_query(
1104 			(inplace_cb_query_func_type*)cb->cb));
1105 		(void)(*(inplace_cb_query_func_type*)cb->cb)(qinfo, flags,
1106 			qstate, addr, addrlen, zone, zonelen, region,
1107 			cb->id, cb->cb_arg);
1108 	}
1109 	return 1;
1110 }
1111 
1112 int inplace_cb_edns_back_parsed_call(struct module_env* env,
1113 	struct module_qstate* qstate)
1114 {
1115 	struct inplace_cb* cb =
1116 		env->inplace_cb_lists[inplace_cb_edns_back_parsed];
1117 	for(; cb; cb=cb->next) {
1118 		fptr_ok(fptr_whitelist_inplace_cb_edns_back_parsed(
1119 			(inplace_cb_edns_back_parsed_func_type*)cb->cb));
1120 		(void)(*(inplace_cb_edns_back_parsed_func_type*)cb->cb)(qstate,
1121 			cb->id, cb->cb_arg);
1122 	}
1123 	return 1;
1124 }
1125 
1126 int inplace_cb_query_response_call(struct module_env* env,
1127 	struct module_qstate* qstate, struct dns_msg* response) {
1128 	struct inplace_cb* cb =
1129 		env->inplace_cb_lists[inplace_cb_query_response];
1130 	for(; cb; cb=cb->next) {
1131 		fptr_ok(fptr_whitelist_inplace_cb_query_response(
1132 			(inplace_cb_query_response_func_type*)cb->cb));
1133 		(void)(*(inplace_cb_query_response_func_type*)cb->cb)(qstate,
1134 			response, cb->id, cb->cb_arg);
1135 	}
1136 	return 1;
1137 }
1138 
1139 struct edns_option* edns_opt_copy_region(struct edns_option* list,
1140         struct regional* region)
1141 {
1142 	struct edns_option* result = NULL, *cur = NULL, *s;
1143 	while(list) {
1144 		/* copy edns option structure */
1145 		s = regional_alloc_init(region, list, sizeof(*list));
1146 		if(!s) return NULL;
1147 		s->next = NULL;
1148 
1149 		/* copy option data */
1150 		if(s->opt_data) {
1151 			s->opt_data = regional_alloc_init(region, s->opt_data,
1152 				s->opt_len);
1153 			if(!s->opt_data)
1154 				return NULL;
1155 		}
1156 
1157 		/* link into list */
1158 		if(cur)
1159 			cur->next = s;
1160 		else	result = s;
1161 		cur = s;
1162 
1163 		/* examine next element */
1164 		list = list->next;
1165 	}
1166 	return result;
1167 }
1168 
1169 int edns_opt_compare(struct edns_option* p, struct edns_option* q)
1170 {
1171 	if(!p && !q) return 0;
1172 	if(!p) return -1;
1173 	if(!q) return 1;
1174 	log_assert(p && q);
1175 	if(p->opt_code != q->opt_code)
1176 		return (int)q->opt_code - (int)p->opt_code;
1177 	if(p->opt_len != q->opt_len)
1178 		return (int)q->opt_len - (int)p->opt_len;
1179 	if(p->opt_len != 0)
1180 		return memcmp(p->opt_data, q->opt_data, p->opt_len);
1181 	return 0;
1182 }
1183 
1184 int edns_opt_list_compare(struct edns_option* p, struct edns_option* q)
1185 {
1186 	int r;
1187 	while(p && q) {
1188 		r = edns_opt_compare(p, q);
1189 		if(r != 0)
1190 			return r;
1191 		p = p->next;
1192 		q = q->next;
1193 	}
1194 	if(p || q) {
1195 		/* uneven length lists */
1196 		if(p) return 1;
1197 		if(q) return -1;
1198 	}
1199 	return 0;
1200 }
1201 
1202 void edns_opt_list_free(struct edns_option* list)
1203 {
1204 	struct edns_option* n;
1205 	while(list) {
1206 		free(list->opt_data);
1207 		n = list->next;
1208 		free(list);
1209 		list = n;
1210 	}
1211 }
1212 
1213 struct edns_option* edns_opt_copy_alloc(struct edns_option* list)
1214 {
1215 	struct edns_option* result = NULL, *cur = NULL, *s;
1216 	while(list) {
1217 		/* copy edns option structure */
1218 		s = memdup(list, sizeof(*list));
1219 		if(!s) {
1220 			edns_opt_list_free(result);
1221 			return NULL;
1222 		}
1223 		s->next = NULL;
1224 
1225 		/* copy option data */
1226 		if(s->opt_data) {
1227 			s->opt_data = memdup(s->opt_data, s->opt_len);
1228 			if(!s->opt_data) {
1229 				free(s);
1230 				edns_opt_list_free(result);
1231 				return NULL;
1232 			}
1233 		}
1234 
1235 		/* link into list */
1236 		if(cur)
1237 			cur->next = s;
1238 		else	result = s;
1239 		cur = s;
1240 
1241 		/* examine next element */
1242 		list = list->next;
1243 	}
1244 	return result;
1245 }
1246 
1247 struct edns_option* edns_opt_list_find(struct edns_option* list, uint16_t code)
1248 {
1249 	struct edns_option* p;
1250 	for(p=list; p; p=p->next) {
1251 		if(p->opt_code == code)
1252 			return p;
1253 	}
1254 	return NULL;
1255 }
1256