xref: /freebsd/contrib/ldns/packet.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*
2  * packet.c
3  *
4  * dns packet implementation
5  *
6  * a Net::DNS like library for C
7  *
8  * (c) NLnet Labs, 2004-2006
9  *
10  * See the file LICENSE for the license
11  */
12 
13 #include <ldns/config.h>
14 
15 #include <ldns/ldns.h>
16 
17 #include <strings.h>
18 #include <limits.h>
19 
20 #ifdef HAVE_SSL
21 #include <openssl/rand.h>
22 #endif
23 
24 /* Access functions
25  * do this as functions to get type checking
26  */
27 
28 #define LDNS_EDNS_MASK_DO_BIT 0x8000
29 
30 /* TODO defines for 3600 */
31 /* convert to and from numerical flag values */
32 ldns_lookup_table ldns_edns_flags[] = {
33 	{ 3600, "do"},
34 	{ 0, NULL}
35 };
36 
37 /* read */
38 uint16_t
39 ldns_pkt_id(const ldns_pkt *packet)
40 {
41 	return packet->_header->_id;
42 }
43 
44 bool
45 ldns_pkt_qr(const ldns_pkt *packet)
46 {
47 	return packet->_header->_qr;
48 }
49 
50 bool
51 ldns_pkt_aa(const ldns_pkt *packet)
52 {
53 	return packet->_header->_aa;
54 }
55 
56 bool
57 ldns_pkt_tc(const ldns_pkt *packet)
58 {
59 	return packet->_header->_tc;
60 }
61 
62 bool
63 ldns_pkt_rd(const ldns_pkt *packet)
64 {
65 	return packet->_header->_rd;
66 }
67 
68 bool
69 ldns_pkt_cd(const ldns_pkt *packet)
70 {
71 	return packet->_header->_cd;
72 }
73 
74 bool
75 ldns_pkt_ra(const ldns_pkt *packet)
76 {
77 	return packet->_header->_ra;
78 }
79 
80 bool
81 ldns_pkt_ad(const ldns_pkt *packet)
82 {
83 	return packet->_header->_ad;
84 }
85 
86 ldns_pkt_opcode
87 ldns_pkt_get_opcode(const ldns_pkt *packet)
88 {
89 	return packet->_header->_opcode;
90 }
91 
92 ldns_pkt_rcode
93 ldns_pkt_get_rcode(const ldns_pkt *packet)
94 {
95 	return packet->_header->_rcode;
96 }
97 
98 uint16_t
99 ldns_pkt_qdcount(const ldns_pkt *packet)
100 {
101 	return packet->_header->_qdcount;
102 }
103 
104 uint16_t
105 ldns_pkt_ancount(const ldns_pkt *packet)
106 {
107 	return packet->_header->_ancount;
108 }
109 
110 uint16_t
111 ldns_pkt_nscount(const ldns_pkt *packet)
112 {
113 	return packet->_header->_nscount;
114 }
115 
116 uint16_t
117 ldns_pkt_arcount(const ldns_pkt *packet)
118 {
119 	return packet->_header->_arcount;
120 }
121 
122 ldns_rr_list *
123 ldns_pkt_question(const ldns_pkt *packet)
124 {
125 	return packet->_question;
126 }
127 
128 ldns_rr_list *
129 ldns_pkt_answer(const ldns_pkt *packet)
130 {
131 	return packet->_answer;
132 }
133 
134 ldns_rr_list *
135 ldns_pkt_authority(const ldns_pkt *packet)
136 {
137 	return packet->_authority;
138 }
139 
140 ldns_rr_list *
141 ldns_pkt_additional(const ldns_pkt *packet)
142 {
143 	return packet->_additional;
144 }
145 
146 /* return ALL section concatenated */
147 ldns_rr_list *
148 ldns_pkt_all(const ldns_pkt *packet)
149 {
150 	ldns_rr_list *all, *prev_all;
151 
152 	all = ldns_rr_list_cat_clone(
153 			ldns_pkt_question(packet),
154 			ldns_pkt_answer(packet));
155 	prev_all = all;
156 	all = ldns_rr_list_cat_clone(all,
157 			ldns_pkt_authority(packet));
158 	ldns_rr_list_deep_free(prev_all);
159 	prev_all = all;
160 	all = ldns_rr_list_cat_clone(all,
161 			ldns_pkt_additional(packet));
162 	ldns_rr_list_deep_free(prev_all);
163 	return all;
164 }
165 
166 ldns_rr_list *
167 ldns_pkt_all_noquestion(const ldns_pkt *packet)
168 {
169 	ldns_rr_list *all, *all2;
170 
171 	all = ldns_rr_list_cat_clone(
172 			ldns_pkt_answer(packet),
173 			ldns_pkt_authority(packet));
174 	all2 = ldns_rr_list_cat_clone(all,
175 			ldns_pkt_additional(packet));
176 
177 	ldns_rr_list_deep_free(all);
178 	return all2;
179 }
180 
181 size_t
182 ldns_pkt_size(const ldns_pkt *packet)
183 {
184 	return packet->_size;
185 }
186 
187 uint32_t
188 ldns_pkt_querytime(const ldns_pkt *packet)
189 {
190 	return packet->_querytime;
191 }
192 
193 ldns_rdf *
194 ldns_pkt_answerfrom(const ldns_pkt *packet)
195 {
196 	return packet->_answerfrom;
197 }
198 
199 struct timeval
200 ldns_pkt_timestamp(const ldns_pkt *packet)
201 {
202 	return packet->timestamp;
203 }
204 
205 uint16_t
206 ldns_pkt_edns_udp_size(const ldns_pkt *packet)
207 {
208 	return packet->_edns_udp_size;
209 }
210 
211 uint8_t
212 ldns_pkt_edns_extended_rcode(const ldns_pkt *packet)
213 {
214 	return packet->_edns_extended_rcode;
215 }
216 
217 uint8_t
218 ldns_pkt_edns_version(const ldns_pkt *packet)
219 {
220 	return packet->_edns_version;
221 }
222 
223 uint16_t
224 ldns_pkt_edns_z(const ldns_pkt *packet)
225 {
226 	return packet->_edns_z;
227 }
228 
229 bool
230 ldns_pkt_edns_do(const ldns_pkt *packet)
231 {
232 	return (packet->_edns_z & LDNS_EDNS_MASK_DO_BIT);
233 }
234 
235 void
236 ldns_pkt_set_edns_do(ldns_pkt *packet, bool value)
237 {
238 	if (value) {
239 		packet->_edns_z = packet->_edns_z | LDNS_EDNS_MASK_DO_BIT;
240 	} else {
241 		packet->_edns_z = packet->_edns_z & ~LDNS_EDNS_MASK_DO_BIT;
242 	}
243 }
244 
245 ldns_rdf *
246 ldns_pkt_edns_data(const ldns_pkt *packet)
247 {
248 	return packet->_edns_data;
249 }
250 
251 /* return only those rr that share the ownername */
252 ldns_rr_list *
253 ldns_pkt_rr_list_by_name(const ldns_pkt *packet,
254                          const ldns_rdf *ownername,
255                          ldns_pkt_section sec)
256 {
257 	ldns_rr_list *rrs;
258 	ldns_rr_list *ret;
259 	uint16_t i;
260 
261 	if (!packet) {
262 		return NULL;
263 	}
264 
265 	rrs = ldns_pkt_get_section_clone(packet, sec);
266 	ret = NULL;
267 
268 	for(i = 0; i < ldns_rr_list_rr_count(rrs); i++) {
269 		if (ldns_dname_compare(ldns_rr_owner(
270 						ldns_rr_list_rr(rrs, i)),
271 					ownername) == 0) {
272 			/* owner names match */
273 			if (ret == NULL) {
274 				ret = ldns_rr_list_new();
275 			}
276 			ldns_rr_list_push_rr(ret,
277 					     ldns_rr_clone(
278 						ldns_rr_list_rr(rrs, i))
279 					    );
280 		}
281 	}
282 
283 	ldns_rr_list_deep_free(rrs);
284 
285 	return ret;
286 }
287 
288 /* return only those rr that share a type */
289 ldns_rr_list *
290 ldns_pkt_rr_list_by_type(const ldns_pkt *packet,
291                          ldns_rr_type type,
292                          ldns_pkt_section sec)
293 {
294 	ldns_rr_list *rrs;
295 	ldns_rr_list *new;
296 	uint16_t i;
297 
298 	if(!packet) {
299 		return NULL;
300 	}
301 
302 	rrs = ldns_pkt_get_section_clone(packet, sec);
303 	new = ldns_rr_list_new();
304 
305 	for(i = 0; i < ldns_rr_list_rr_count(rrs); i++) {
306 		if (type == ldns_rr_get_type(ldns_rr_list_rr(rrs, i))) {
307 			/* types match */
308 			ldns_rr_list_push_rr(new,
309 			                     ldns_rr_clone(
310 			                     	ldns_rr_list_rr(rrs, i))
311 					     );
312 		}
313 	}
314 	ldns_rr_list_deep_free(rrs);
315 
316 	if (ldns_rr_list_rr_count(new) == 0) {
317 		ldns_rr_list_free(new);
318 		return NULL;
319 	} else {
320 		return new;
321 	}
322 }
323 
324 /* return only those rrs that share name and type */
325 ldns_rr_list *
326 ldns_pkt_rr_list_by_name_and_type(const ldns_pkt *packet,
327                                   const ldns_rdf *ownername,
328                                   ldns_rr_type type,
329                                   ldns_pkt_section sec)
330 {
331 	ldns_rr_list *rrs;
332 	ldns_rr_list *new;
333 	ldns_rr_list *ret;
334 	uint16_t i;
335 
336 	if(!packet) {
337 		return NULL;
338 	}
339 
340 	rrs = ldns_pkt_get_section_clone(packet, sec);
341 	new = ldns_rr_list_new();
342 	ret = NULL;
343 
344 	for(i = 0; i < ldns_rr_list_rr_count(rrs); i++) {
345 		if (type == ldns_rr_get_type(ldns_rr_list_rr(rrs, i)) &&
346 		    ldns_dname_compare(ldns_rr_owner(ldns_rr_list_rr(rrs, i)),
347 		                     ownername
348 		                    ) == 0
349 		   ) {
350 			/* types match */
351 			ldns_rr_list_push_rr(new, ldns_rr_clone(ldns_rr_list_rr(rrs, i)));
352 			ret = new;
353 		}
354 	}
355 	ldns_rr_list_deep_free(rrs);
356 	if (!ret) {
357 		ldns_rr_list_free(new);
358 	}
359 	return ret;
360 }
361 
362 bool
363 ldns_pkt_rr(const ldns_pkt *pkt, ldns_pkt_section sec, const ldns_rr *rr)
364 {
365 	bool result = false;
366 
367 	switch (sec) {
368 	case LDNS_SECTION_QUESTION:
369 		return ldns_rr_list_contains_rr(ldns_pkt_question(pkt), rr);
370 	case LDNS_SECTION_ANSWER:
371 		return ldns_rr_list_contains_rr(ldns_pkt_answer(pkt), rr);
372 	case LDNS_SECTION_AUTHORITY:
373 		return ldns_rr_list_contains_rr(ldns_pkt_authority(pkt), rr);
374 	case LDNS_SECTION_ADDITIONAL:
375 		return ldns_rr_list_contains_rr(ldns_pkt_additional(pkt), rr);
376 	case LDNS_SECTION_ANY:
377 		result = ldns_rr_list_contains_rr(ldns_pkt_question(pkt), rr);
378 	case LDNS_SECTION_ANY_NOQUESTION:
379 		result = result
380 		    || ldns_rr_list_contains_rr(ldns_pkt_answer(pkt), rr)
381 		    || ldns_rr_list_contains_rr(ldns_pkt_authority(pkt), rr)
382 		    || ldns_rr_list_contains_rr(ldns_pkt_additional(pkt), rr);
383 	}
384 
385 	return result;
386 }
387 
388 uint16_t
389 ldns_pkt_section_count(const ldns_pkt *packet, ldns_pkt_section s)
390 {
391 	switch(s) {
392 	case LDNS_SECTION_QUESTION:
393 		return ldns_pkt_qdcount(packet);
394 	case LDNS_SECTION_ANSWER:
395 		return ldns_pkt_ancount(packet);
396 	case LDNS_SECTION_AUTHORITY:
397 		return ldns_pkt_nscount(packet);
398 	case LDNS_SECTION_ADDITIONAL:
399 		return ldns_pkt_arcount(packet);
400 	case LDNS_SECTION_ANY:
401 		return ldns_pkt_qdcount(packet) +
402 			ldns_pkt_ancount(packet) +
403 			ldns_pkt_nscount(packet) +
404 			ldns_pkt_arcount(packet);
405 	case LDNS_SECTION_ANY_NOQUESTION:
406 		return ldns_pkt_ancount(packet) +
407 			ldns_pkt_nscount(packet) +
408 			ldns_pkt_arcount(packet);
409 	default:
410 		return 0;
411 	}
412 }
413 
414 bool
415 ldns_pkt_empty(ldns_pkt *p)
416 {
417 	if (!p) {
418 		return true; /* NULL is empty? */
419 	}
420 	if (ldns_pkt_section_count(p, LDNS_SECTION_ANY) > 0) {
421 		return false;
422 	} else {
423 		return true;
424     }
425 }
426 
427 
428 ldns_rr_list *
429 ldns_pkt_get_section_clone(const ldns_pkt *packet, ldns_pkt_section s)
430 {
431 	switch(s) {
432 	case LDNS_SECTION_QUESTION:
433 		return ldns_rr_list_clone(ldns_pkt_question(packet));
434 	case LDNS_SECTION_ANSWER:
435 		return ldns_rr_list_clone(ldns_pkt_answer(packet));
436 	case LDNS_SECTION_AUTHORITY:
437 		return ldns_rr_list_clone(ldns_pkt_authority(packet));
438 	case LDNS_SECTION_ADDITIONAL:
439 		return ldns_rr_list_clone(ldns_pkt_additional(packet));
440 	case LDNS_SECTION_ANY:
441 		/* these are already clones */
442 		return ldns_pkt_all(packet);
443 	case LDNS_SECTION_ANY_NOQUESTION:
444 		return ldns_pkt_all_noquestion(packet);
445 	default:
446 		return NULL;
447 	}
448 }
449 
450 ldns_rr *ldns_pkt_tsig(const ldns_pkt *pkt) {
451 	return pkt->_tsig_rr;
452 }
453 
454 /* write */
455 void
456 ldns_pkt_set_id(ldns_pkt *packet, uint16_t id)
457 {
458 	packet->_header->_id = id;
459 }
460 
461 void
462 ldns_pkt_set_random_id(ldns_pkt *packet)
463 {
464 	uint16_t rid = ldns_get_random();
465 	ldns_pkt_set_id(packet, rid);
466 }
467 
468 
469 void
470 ldns_pkt_set_qr(ldns_pkt *packet, bool qr)
471 {
472 	packet->_header->_qr = qr;
473 }
474 
475 void
476 ldns_pkt_set_aa(ldns_pkt *packet, bool aa)
477 {
478 	packet->_header->_aa = aa;
479 }
480 
481 void
482 ldns_pkt_set_tc(ldns_pkt *packet, bool tc)
483 {
484 	packet->_header->_tc = tc;
485 }
486 
487 void
488 ldns_pkt_set_rd(ldns_pkt *packet, bool rd)
489 {
490 	packet->_header->_rd = rd;
491 }
492 
493 void
494 ldns_pkt_set_additional(ldns_pkt *p, ldns_rr_list *rr)
495 {
496 	p->_additional = rr;
497 }
498 
499 void
500 ldns_pkt_set_question(ldns_pkt *p, ldns_rr_list *rr)
501 {
502 	p->_question = rr;
503 }
504 
505 void
506 ldns_pkt_set_answer(ldns_pkt *p, ldns_rr_list *rr)
507 {
508 	p->_answer = rr;
509 }
510 
511 void
512 ldns_pkt_set_authority(ldns_pkt *p, ldns_rr_list *rr)
513 {
514 	p->_authority = rr;
515 }
516 
517 void
518 ldns_pkt_set_cd(ldns_pkt *packet, bool cd)
519 {
520 	packet->_header->_cd = cd;
521 }
522 
523 void
524 ldns_pkt_set_ra(ldns_pkt *packet, bool ra)
525 {
526 	packet->_header->_ra = ra;
527 }
528 
529 void
530 ldns_pkt_set_ad(ldns_pkt *packet, bool ad)
531 {
532 	packet->_header->_ad = ad;
533 }
534 
535 void
536 ldns_pkt_set_opcode(ldns_pkt *packet, ldns_pkt_opcode opcode)
537 {
538 	packet->_header->_opcode = opcode;
539 }
540 
541 void
542 ldns_pkt_set_rcode(ldns_pkt *packet, uint8_t rcode)
543 {
544 	packet->_header->_rcode = rcode;
545 }
546 
547 void
548 ldns_pkt_set_qdcount(ldns_pkt *packet, uint16_t qdcount)
549 {
550 	packet->_header->_qdcount = qdcount;
551 }
552 
553 void
554 ldns_pkt_set_ancount(ldns_pkt *packet, uint16_t ancount)
555 {
556 	packet->_header->_ancount = ancount;
557 }
558 
559 void
560 ldns_pkt_set_nscount(ldns_pkt *packet, uint16_t nscount)
561 {
562 	packet->_header->_nscount = nscount;
563 }
564 
565 void
566 ldns_pkt_set_arcount(ldns_pkt *packet, uint16_t arcount)
567 {
568 	packet->_header->_arcount = arcount;
569 }
570 
571 void
572 ldns_pkt_set_querytime(ldns_pkt *packet, uint32_t time)
573 {
574 	packet->_querytime = time;
575 }
576 
577 void
578 ldns_pkt_set_answerfrom(ldns_pkt *packet, ldns_rdf *answerfrom)
579 {
580 	packet->_answerfrom = answerfrom;
581 }
582 
583 void
584 ldns_pkt_set_timestamp(ldns_pkt *packet, struct timeval timeval)
585 {
586 	packet->timestamp.tv_sec = timeval.tv_sec;
587 	packet->timestamp.tv_usec = timeval.tv_usec;
588 }
589 
590 void
591 ldns_pkt_set_size(ldns_pkt *packet, size_t s)
592 {
593 	packet->_size = s;
594 }
595 
596 void
597 ldns_pkt_set_edns_udp_size(ldns_pkt *packet, uint16_t s)
598 {
599 	packet->_edns_udp_size = s;
600 }
601 
602 void
603 ldns_pkt_set_edns_extended_rcode(ldns_pkt *packet, uint8_t c)
604 {
605 	packet->_edns_extended_rcode = c;
606 }
607 
608 void
609 ldns_pkt_set_edns_version(ldns_pkt *packet, uint8_t v)
610 {
611 	packet->_edns_version = v;
612 }
613 
614 void
615 ldns_pkt_set_edns_z(ldns_pkt *packet, uint16_t z)
616 {
617 	packet->_edns_z = z;
618 }
619 
620 void
621 ldns_pkt_set_edns_data(ldns_pkt *packet, ldns_rdf *data)
622 {
623 	packet->_edns_data = data;
624 }
625 
626 void
627 ldns_pkt_set_section_count(ldns_pkt *packet, ldns_pkt_section s, uint16_t count)
628 {
629 	switch(s) {
630 		case LDNS_SECTION_QUESTION:
631 			ldns_pkt_set_qdcount(packet, count);
632 			break;
633 		case LDNS_SECTION_ANSWER:
634 			ldns_pkt_set_ancount(packet, count);
635 			break;
636 		case LDNS_SECTION_AUTHORITY:
637 			ldns_pkt_set_nscount(packet, count);
638 			break;
639 		case LDNS_SECTION_ADDITIONAL:
640 			ldns_pkt_set_arcount(packet, count);
641 			break;
642 		case LDNS_SECTION_ANY:
643 		case LDNS_SECTION_ANY_NOQUESTION:
644 			break;
645 	}
646 }
647 
648 void ldns_pkt_set_tsig(ldns_pkt *pkt, ldns_rr *rr)
649 {
650 	pkt->_tsig_rr = rr;
651 }
652 
653 bool
654 ldns_pkt_push_rr(ldns_pkt *packet, ldns_pkt_section section, ldns_rr *rr)
655 {
656 	switch(section) {
657 		case LDNS_SECTION_QUESTION:
658 			if (!ldns_rr_list_push_rr(ldns_pkt_question(packet), rr)) {
659 				return false;
660 			}
661 			ldns_pkt_set_qdcount(packet, ldns_pkt_qdcount(packet) + 1);
662 			break;
663 		case LDNS_SECTION_ANSWER:
664 			if (!ldns_rr_list_push_rr(ldns_pkt_answer(packet), rr)) {
665 				return false;
666 			}
667 			ldns_pkt_set_ancount(packet, ldns_pkt_ancount(packet) + 1);
668 			break;
669 		case LDNS_SECTION_AUTHORITY:
670 			if (!ldns_rr_list_push_rr(ldns_pkt_authority(packet), rr)) {
671 				return false;
672 			}
673 			ldns_pkt_set_nscount(packet, ldns_pkt_nscount(packet) + 1);
674 			break;
675 		case LDNS_SECTION_ADDITIONAL:
676 			if (!ldns_rr_list_push_rr(ldns_pkt_additional(packet), rr)) {
677 				return false;
678 			}
679 			ldns_pkt_set_arcount(packet, ldns_pkt_arcount(packet) + 1);
680 			break;
681 		case LDNS_SECTION_ANY:
682 		case LDNS_SECTION_ANY_NOQUESTION:
683 			/* shouldn't this error? */
684 			break;
685 	}
686 	return true;
687 }
688 
689 bool
690 ldns_pkt_safe_push_rr(ldns_pkt *pkt, ldns_pkt_section sec, ldns_rr *rr)
691 {
692 
693 	/* check to see if its there */
694 	if (ldns_pkt_rr(pkt, sec, rr)) {
695 		/* already there */
696 		return false;
697 	}
698 	return ldns_pkt_push_rr(pkt, sec, rr);
699 }
700 
701 bool
702 ldns_pkt_push_rr_list(ldns_pkt *p, ldns_pkt_section s, ldns_rr_list *list)
703 {
704 	size_t i;
705 	for(i = 0; i < ldns_rr_list_rr_count(list); i++) {
706 		if (!ldns_pkt_push_rr(p, s, ldns_rr_list_rr(list, i))) {
707 			return false;
708 		}
709 	}
710 	return true;
711 }
712 
713 bool
714 ldns_pkt_safe_push_rr_list(ldns_pkt *p, ldns_pkt_section s, ldns_rr_list *list)
715 {
716 	size_t i;
717 	for(i = 0; i < ldns_rr_list_rr_count(list); i++) {
718 		if (!ldns_pkt_safe_push_rr(p, s, ldns_rr_list_rr(list, i))) {
719 			return false;
720 		}
721 	}
722 	return true;
723 }
724 
725 bool
726 ldns_pkt_edns(const ldns_pkt *pkt) {
727 	return (ldns_pkt_edns_udp_size(pkt) > 0 ||
728 		ldns_pkt_edns_extended_rcode(pkt) > 0 ||
729 		ldns_pkt_edns_data(pkt) ||
730 		ldns_pkt_edns_do(pkt) ||
731                 pkt->_edns_present
732 	       );
733 }
734 
735 
736 /* Create/destroy/convert functions
737  */
738 ldns_pkt *
739 ldns_pkt_new(void)
740 {
741 	ldns_pkt *packet;
742 	packet = LDNS_MALLOC(ldns_pkt);
743 	if (!packet) {
744 		return NULL;
745 	}
746 
747 	packet->_header = LDNS_MALLOC(ldns_hdr);
748 	if (!packet->_header) {
749 		LDNS_FREE(packet);
750 		return NULL;
751 	}
752 
753 	packet->_question = ldns_rr_list_new();
754 	packet->_answer = ldns_rr_list_new();
755 	packet->_authority = ldns_rr_list_new();
756 	packet->_additional = ldns_rr_list_new();
757 
758 	/* default everything to false */
759 	ldns_pkt_set_qr(packet, false);
760 	ldns_pkt_set_aa(packet, false);
761 	ldns_pkt_set_tc(packet, false);
762 	ldns_pkt_set_rd(packet, false);
763 	ldns_pkt_set_ra(packet, false);
764 	ldns_pkt_set_ad(packet, false);
765 	ldns_pkt_set_cd(packet, false);
766 
767 	ldns_pkt_set_opcode(packet, LDNS_PACKET_QUERY);
768 	ldns_pkt_set_rcode(packet, 0);
769 	ldns_pkt_set_id(packet, 0);
770 	ldns_pkt_set_size(packet, 0);
771 	ldns_pkt_set_querytime(packet, 0);
772 	memset(&packet->timestamp, 0, sizeof(packet->timestamp));
773 	ldns_pkt_set_answerfrom(packet, NULL);
774 	ldns_pkt_set_section_count(packet, LDNS_SECTION_QUESTION, 0);
775 	ldns_pkt_set_section_count(packet, LDNS_SECTION_ANSWER, 0);
776 	ldns_pkt_set_section_count(packet, LDNS_SECTION_AUTHORITY, 0);
777 	ldns_pkt_set_section_count(packet, LDNS_SECTION_ADDITIONAL, 0);
778 
779 	ldns_pkt_set_edns_udp_size(packet, 0);
780 	ldns_pkt_set_edns_extended_rcode(packet, 0);
781 	ldns_pkt_set_edns_version(packet, 0);
782 	ldns_pkt_set_edns_z(packet, 0);
783 	ldns_pkt_set_edns_data(packet, NULL);
784 	packet->_edns_present = false;
785 
786 	ldns_pkt_set_tsig(packet, NULL);
787 
788 	return packet;
789 }
790 
791 void
792 ldns_pkt_free(ldns_pkt *packet)
793 {
794 	if (packet) {
795 		LDNS_FREE(packet->_header);
796 		ldns_rr_list_deep_free(packet->_question);
797 		ldns_rr_list_deep_free(packet->_answer);
798 		ldns_rr_list_deep_free(packet->_authority);
799 		ldns_rr_list_deep_free(packet->_additional);
800 		ldns_rr_free(packet->_tsig_rr);
801 		ldns_rdf_deep_free(packet->_edns_data);
802 		ldns_rdf_deep_free(packet->_answerfrom);
803 		LDNS_FREE(packet);
804 	}
805 }
806 
807 bool
808 ldns_pkt_set_flags(ldns_pkt *packet, uint16_t flags)
809 {
810 	if (!packet) {
811 		return false;
812 	}
813 	if ((flags & LDNS_QR) == LDNS_QR) {
814 		ldns_pkt_set_qr(packet, true);
815 	}
816 	if ((flags & LDNS_AA) == LDNS_AA) {
817 		ldns_pkt_set_aa(packet, true);
818 	}
819 	if ((flags & LDNS_RD) == LDNS_RD) {
820 		ldns_pkt_set_rd(packet, true);
821 	}
822 	if ((flags & LDNS_TC) == LDNS_TC) {
823 		ldns_pkt_set_tc(packet, true);
824 	}
825 	if ((flags & LDNS_CD) == LDNS_CD) {
826 		ldns_pkt_set_cd(packet, true);
827 	}
828 	if ((flags & LDNS_RA) == LDNS_RA) {
829 		ldns_pkt_set_ra(packet, true);
830 	}
831 	if ((flags & LDNS_AD) == LDNS_AD) {
832 		ldns_pkt_set_ad(packet, true);
833 	}
834 	return true;
835 }
836 
837 
838 static ldns_rr*
839 ldns_pkt_authsoa(const ldns_rdf* rr_name, ldns_rr_class rr_class)
840 {
841 	ldns_rr* soa_rr = ldns_rr_new();
842 	ldns_rdf *owner_rdf;
843 	ldns_rdf *mname_rdf;
844 	ldns_rdf *rname_rdf;
845 	ldns_rdf *serial_rdf;
846 	ldns_rdf *refresh_rdf;
847 	ldns_rdf *retry_rdf;
848 	ldns_rdf *expire_rdf;
849 	ldns_rdf *minimum_rdf;
850 
851 	if (!soa_rr) {
852 		return NULL;
853 	}
854 	owner_rdf = ldns_rdf_clone(rr_name);
855 	if (!owner_rdf) {
856 		ldns_rr_free(soa_rr);
857 		return NULL;
858 	}
859 
860 	ldns_rr_set_owner(soa_rr, owner_rdf);
861 	ldns_rr_set_type(soa_rr, LDNS_RR_TYPE_SOA);
862 	ldns_rr_set_class(soa_rr, rr_class);
863 	ldns_rr_set_question(soa_rr, false);
864 
865 	if (ldns_str2rdf_dname(&mname_rdf, ".") != LDNS_STATUS_OK) {
866 		ldns_rr_free(soa_rr);
867 		return NULL;
868 	} else {
869 		ldns_rr_push_rdf(soa_rr, mname_rdf);
870 	}
871 	if (ldns_str2rdf_dname(&rname_rdf, ".") != LDNS_STATUS_OK) {
872 		ldns_rr_free(soa_rr);
873 		return NULL;
874 	} else {
875 		ldns_rr_push_rdf(soa_rr, rname_rdf);
876 	}
877 	serial_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
878 	if (!serial_rdf) {
879 		ldns_rr_free(soa_rr);
880 		return NULL;
881 	} else {
882 		ldns_rr_push_rdf(soa_rr, serial_rdf);
883 	}
884 	refresh_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
885 	if (!refresh_rdf) {
886 		ldns_rr_free(soa_rr);
887 		return NULL;
888 	} else {
889 		ldns_rr_push_rdf(soa_rr, refresh_rdf);
890 	}
891 	retry_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
892 	if (!retry_rdf) {
893 		ldns_rr_free(soa_rr);
894 		return NULL;
895 	} else {
896 		ldns_rr_push_rdf(soa_rr, retry_rdf);
897 	}
898 	expire_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
899 	if (!expire_rdf) {
900 		ldns_rr_free(soa_rr);
901 		return NULL;
902 	} else {
903 		ldns_rr_push_rdf(soa_rr, expire_rdf);
904 	}
905 	minimum_rdf = ldns_native2rdf_int32(LDNS_RDF_TYPE_INT32, 0);
906 	if (!minimum_rdf) {
907 		ldns_rr_free(soa_rr);
908 		return NULL;
909 	} else {
910 		ldns_rr_push_rdf(soa_rr, minimum_rdf);
911 	}
912 	return soa_rr;
913 }
914 
915 
916 static ldns_status
917 ldns_pkt_query_new_frm_str_internal(ldns_pkt **p, const char *name,
918 	ldns_rr_type rr_type, ldns_rr_class rr_class, uint16_t flags,
919 	ldns_rr* authsoa_rr)
920 {
921 	ldns_pkt *packet;
922 	ldns_rr *question_rr;
923 	ldns_rdf *name_rdf;
924 
925 	packet = ldns_pkt_new();
926 	if (!packet) {
927 		return LDNS_STATUS_MEM_ERR;
928 	}
929 
930 	if (!ldns_pkt_set_flags(packet, flags)) {
931 		return LDNS_STATUS_ERR;
932 	}
933 
934 	question_rr = ldns_rr_new();
935 	if (!question_rr) {
936 		return LDNS_STATUS_MEM_ERR;
937 	}
938 
939 	if (rr_type == 0) {
940 		rr_type = LDNS_RR_TYPE_A;
941 	}
942 	if (rr_class == 0) {
943 		rr_class = LDNS_RR_CLASS_IN;
944 	}
945 
946 	if (ldns_str2rdf_dname(&name_rdf, name) == LDNS_STATUS_OK) {
947 		ldns_rr_set_owner(question_rr, name_rdf);
948 		ldns_rr_set_type(question_rr, rr_type);
949 		ldns_rr_set_class(question_rr, rr_class);
950                 ldns_rr_set_question(question_rr, true);
951 
952 		ldns_pkt_push_rr(packet, LDNS_SECTION_QUESTION, question_rr);
953 	} else {
954 		ldns_rr_free(question_rr);
955 		ldns_pkt_free(packet);
956 		return LDNS_STATUS_ERR;
957 	}
958 
959 	if (authsoa_rr) {
960 		ldns_pkt_push_rr(packet, LDNS_SECTION_AUTHORITY, authsoa_rr);
961 	}
962 
963 	packet->_tsig_rr = NULL;
964 	ldns_pkt_set_answerfrom(packet, NULL);
965 	if (p) {
966 		*p = packet;
967 		return LDNS_STATUS_OK;
968 	} else {
969 		ldns_pkt_free(packet);
970 		return LDNS_STATUS_NULL;
971 	}
972 }
973 
974 ldns_status
975 ldns_pkt_query_new_frm_str(ldns_pkt **p, const char *name,
976 	ldns_rr_type rr_type, ldns_rr_class rr_class, uint16_t flags)
977 {
978 	return ldns_pkt_query_new_frm_str_internal(p, name, rr_type,
979 		rr_class, flags, NULL);
980 }
981 
982 ldns_status
983 ldns_pkt_ixfr_request_new_frm_str(ldns_pkt **p, const char *name,
984 	ldns_rr_class rr_class, uint16_t flags, ldns_rr *soa)
985 {
986 	ldns_rr* authsoa_rr = soa;
987 	if (!authsoa_rr) {
988 		ldns_rdf *name_rdf;
989 		if (ldns_str2rdf_dname(&name_rdf, name) == LDNS_STATUS_OK) {
990 			authsoa_rr = ldns_pkt_authsoa(name_rdf, rr_class);
991 		}
992 		ldns_rdf_free(name_rdf);
993 	}
994 	return ldns_pkt_query_new_frm_str_internal(p, name, LDNS_RR_TYPE_IXFR,
995 		rr_class, flags, authsoa_rr);
996 }
997 
998 static ldns_pkt *
999 ldns_pkt_query_new_internal(ldns_rdf *rr_name, ldns_rr_type rr_type,
1000 	ldns_rr_class rr_class,	uint16_t flags, ldns_rr* authsoa_rr)
1001 {
1002 	ldns_pkt *packet;
1003 	ldns_rr *question_rr;
1004 
1005 	packet = ldns_pkt_new();
1006 	if (!packet) {
1007 		return NULL;
1008 	}
1009 
1010 	if (!ldns_pkt_set_flags(packet, flags)) {
1011 		return NULL;
1012 	}
1013 
1014 	question_rr = ldns_rr_new();
1015 	if (!question_rr) {
1016 		ldns_pkt_free(packet);
1017 		return NULL;
1018 	}
1019 
1020 	if (rr_type == 0) {
1021 		rr_type = LDNS_RR_TYPE_A;
1022 	}
1023 	if (rr_class == 0) {
1024 		rr_class = LDNS_RR_CLASS_IN;
1025 	}
1026 
1027 	ldns_rr_set_owner(question_rr, rr_name);
1028 	ldns_rr_set_type(question_rr, rr_type);
1029 	ldns_rr_set_class(question_rr, rr_class);
1030         ldns_rr_set_question(question_rr, true);
1031 	ldns_pkt_push_rr(packet, LDNS_SECTION_QUESTION, question_rr);
1032 
1033 	if (authsoa_rr) {
1034 		ldns_pkt_push_rr(packet, LDNS_SECTION_AUTHORITY, authsoa_rr);
1035 	}
1036 
1037 	packet->_tsig_rr = NULL;
1038 	return packet;
1039 }
1040 
1041 ldns_pkt *
1042 ldns_pkt_query_new(ldns_rdf *rr_name, ldns_rr_type rr_type,
1043 	ldns_rr_class rr_class,	uint16_t flags)
1044 {
1045 	return ldns_pkt_query_new_internal(rr_name, rr_type,
1046 		rr_class, flags, NULL);
1047 }
1048 
1049 ldns_pkt *
1050 ldns_pkt_ixfr_request_new(ldns_rdf *rr_name, ldns_rr_class rr_class,
1051 	uint16_t flags, ldns_rr* soa)
1052 {
1053 	ldns_rr* authsoa_rr = soa;
1054 	if (!authsoa_rr) {
1055 		authsoa_rr = ldns_pkt_authsoa(rr_name, rr_class);
1056 	}
1057 	return ldns_pkt_query_new_internal(rr_name, LDNS_RR_TYPE_IXFR,
1058 		rr_class, flags, authsoa_rr);
1059 }
1060 
1061 ldns_pkt_type
1062 ldns_pkt_reply_type(const ldns_pkt *p)
1063 {
1064 	ldns_rr_list *tmp;
1065 
1066 	if (!p) {
1067 		return LDNS_PACKET_UNKNOWN;
1068 	}
1069 
1070 	if (ldns_pkt_get_rcode(p) == LDNS_RCODE_NXDOMAIN) {
1071 		return LDNS_PACKET_NXDOMAIN;
1072 	}
1073 
1074 	if (ldns_pkt_ancount(p) == 0 && ldns_pkt_arcount(p) == 0
1075 			&& ldns_pkt_nscount(p) == 1) {
1076 
1077 		/* check for SOA */
1078 		tmp = ldns_pkt_rr_list_by_type(p, LDNS_RR_TYPE_SOA,
1079 					LDNS_SECTION_AUTHORITY);
1080 		if (tmp) {
1081 			ldns_rr_list_deep_free(tmp);
1082 			return LDNS_PACKET_NODATA;
1083 		} else {
1084 			/* I have no idea ... */
1085 		}
1086 	}
1087 
1088 	if (ldns_pkt_ancount(p) == 0 && ldns_pkt_nscount(p) > 0) {
1089 		tmp = ldns_pkt_rr_list_by_type(p, LDNS_RR_TYPE_NS,
1090 		                               LDNS_SECTION_AUTHORITY);
1091 		if (tmp) {
1092 			/* there are nameservers here */
1093 			ldns_rr_list_deep_free(tmp);
1094 			return LDNS_PACKET_REFERRAL;
1095 		} else {
1096 			/* I have no idea */
1097 		}
1098 		ldns_rr_list_deep_free(tmp);
1099 	}
1100 
1101 	/* if we cannot determine the packet type, we say it's an
1102 	 * answer...
1103 	 */
1104 	return LDNS_PACKET_ANSWER;
1105 }
1106 
1107 ldns_pkt *
1108 ldns_pkt_clone(const ldns_pkt *pkt)
1109 {
1110 	ldns_pkt *new_pkt;
1111 
1112 	if (!pkt) {
1113 		return NULL;
1114 	}
1115 	new_pkt = ldns_pkt_new();
1116 
1117 	ldns_pkt_set_id(new_pkt, ldns_pkt_id(pkt));
1118 	ldns_pkt_set_qr(new_pkt, ldns_pkt_qr(pkt));
1119 	ldns_pkt_set_aa(new_pkt, ldns_pkt_aa(pkt));
1120 	ldns_pkt_set_tc(new_pkt, ldns_pkt_tc(pkt));
1121 	ldns_pkt_set_rd(new_pkt, ldns_pkt_rd(pkt));
1122 	ldns_pkt_set_cd(new_pkt, ldns_pkt_cd(pkt));
1123 	ldns_pkt_set_ra(new_pkt, ldns_pkt_ra(pkt));
1124 	ldns_pkt_set_ad(new_pkt, ldns_pkt_ad(pkt));
1125 	ldns_pkt_set_opcode(new_pkt, ldns_pkt_get_opcode(pkt));
1126 	ldns_pkt_set_rcode(new_pkt, ldns_pkt_get_rcode(pkt));
1127 	ldns_pkt_set_qdcount(new_pkt, ldns_pkt_qdcount(pkt));
1128 	ldns_pkt_set_ancount(new_pkt, ldns_pkt_ancount(pkt));
1129 	ldns_pkt_set_nscount(new_pkt, ldns_pkt_nscount(pkt));
1130 	ldns_pkt_set_arcount(new_pkt, ldns_pkt_arcount(pkt));
1131 	if (ldns_pkt_answerfrom(pkt))
1132 		ldns_pkt_set_answerfrom(new_pkt,
1133 			ldns_rdf_clone(ldns_pkt_answerfrom(pkt)));
1134 	ldns_pkt_set_timestamp(new_pkt, ldns_pkt_timestamp(pkt));
1135 	ldns_pkt_set_querytime(new_pkt, ldns_pkt_querytime(pkt));
1136 	ldns_pkt_set_size(new_pkt, ldns_pkt_size(pkt));
1137 	ldns_pkt_set_tsig(new_pkt, ldns_rr_clone(ldns_pkt_tsig(pkt)));
1138 
1139 	ldns_pkt_set_edns_udp_size(new_pkt, ldns_pkt_edns_udp_size(pkt));
1140 	ldns_pkt_set_edns_extended_rcode(new_pkt,
1141 		ldns_pkt_edns_extended_rcode(pkt));
1142 	ldns_pkt_set_edns_version(new_pkt, ldns_pkt_edns_version(pkt));
1143 	new_pkt->_edns_present = pkt->_edns_present;
1144 	ldns_pkt_set_edns_z(new_pkt, ldns_pkt_edns_z(pkt));
1145 	if(ldns_pkt_edns_data(pkt))
1146 		ldns_pkt_set_edns_data(new_pkt,
1147 			ldns_rdf_clone(ldns_pkt_edns_data(pkt)));
1148 	ldns_pkt_set_edns_do(new_pkt, ldns_pkt_edns_do(pkt));
1149 
1150 	ldns_rr_list_deep_free(new_pkt->_question);
1151 	ldns_rr_list_deep_free(new_pkt->_answer);
1152 	ldns_rr_list_deep_free(new_pkt->_authority);
1153 	ldns_rr_list_deep_free(new_pkt->_additional);
1154 	new_pkt->_question = ldns_rr_list_clone(ldns_pkt_question(pkt));
1155 	new_pkt->_answer = ldns_rr_list_clone(ldns_pkt_answer(pkt));
1156 	new_pkt->_authority = ldns_rr_list_clone(ldns_pkt_authority(pkt));
1157 	new_pkt->_additional = ldns_rr_list_clone(ldns_pkt_additional(pkt));
1158 	return new_pkt;
1159 }
1160