2 * util/data/msgencode.c - Encode DNS messages, queries and replies.
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
6 * This software is open source.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
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.
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.
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.
39 * This file contains a routines to encode DNS messages.
43 #include "util/data/msgencode.h"
44 #include "util/data/msgreply.h"
45 #include "util/data/msgparse.h"
46 #include "util/data/dname.h"
48 #include "util/regional.h"
49 #include "util/net_help.h"
50 #include "sldns/sbuffer.h"
52 /** return code that means the function ran out of memory. negative so it does
53 * not conflict with DNS rcodes. */
54 #define RETVAL_OUTMEM -2
55 /** return code that means the data did not fit (completely) in the packet */
56 #define RETVAL_TRUNC -4
57 /** return code that means all is peachy keen. Equal to DNS rcode NOERROR */
61 * Data structure to help domain name compression in outgoing messages.
62 * A tree of dnames and their offsets in the packet is kept.
63 * It is kept sorted, not canonical, but by label at least, so that after
64 * a lookup of a name you know its closest match, and the parent from that
65 * closest match. These are possible compression targets.
67 * It is a binary tree, not a rbtree or balanced tree, as the effort
68 * of keeping it balanced probably outweighs usefulness (given typical
71 struct compress_tree_node {
72 /** left node in tree, all smaller to this */
73 struct compress_tree_node* left;
74 /** right node in tree, all larger than this */
75 struct compress_tree_node* right;
77 /** the parent node - not for tree, but zone parent. One less label */
78 struct compress_tree_node* parent;
79 /** the domain name for this node. Pointer to uncompressed memory. */
81 /** number of labels in domain name, kept to help compare func. */
83 /** offset in packet that points to this dname */
88 * Find domain name in tree, returns exact and closest match.
89 * @param tree: root of tree.
90 * @param dname: pointer to uncompressed dname.
91 * @param labs: number of labels in domain name.
92 * @param match: closest or exact match.
93 * guaranteed to be smaller or equal to the sought dname.
94 * can be null if the tree is empty.
95 * @param matchlabels: number of labels that match with closest match.
96 * can be zero is there is no match.
97 * @param insertpt: insert location for dname, if not found.
98 * @return: 0 if no exact match.
101 compress_tree_search(struct compress_tree_node** tree, uint8_t* dname,
102 int labs, struct compress_tree_node** match, int* matchlabels,
103 struct compress_tree_node*** insertpt)
106 struct compress_tree_node* p = *tree;
107 struct compress_tree_node* close = 0;
108 struct compress_tree_node** prev = tree;
110 if((c = dname_lab_cmp(dname, labs, p->dname, p->labs, &n))
121 close = p; /* p->dname is smaller than dname */
127 *matchlabels = closen;
133 * Lookup a domain name in compression tree.
134 * @param tree: root of tree (not the node with '.').
135 * @param dname: pointer to uncompressed dname.
136 * @param labs: number of labels in domain name.
137 * @param insertpt: insert location for dname, if not found.
138 * @return: 0 if not found or compress treenode with best compression.
140 static struct compress_tree_node*
141 compress_tree_lookup(struct compress_tree_node** tree, uint8_t* dname,
142 int labs, struct compress_tree_node*** insertpt)
144 struct compress_tree_node* p;
147 return 0; /* do not compress root node */
148 if(compress_tree_search(tree, dname, labs, &p, &m, insertpt)) {
152 /* return some ancestor of p that compresses well. */
154 /* www.example.com. (labs=4) matched foo.example.com.(labs=4)
155 * then matchcount = 3. need to go up. */
156 while(p && p->labs > m)
164 * Create node for domain name compression tree.
165 * @param dname: pointer to uncompressed dname (stored in tree).
166 * @param labs: number of labels in dname.
167 * @param offset: offset into packet for dname.
168 * @param region: how to allocate memory for new node.
169 * @return new node or 0 on malloc failure.
171 static struct compress_tree_node*
172 compress_tree_newnode(uint8_t* dname, int labs, size_t offset,
173 struct regional* region)
175 struct compress_tree_node* n = (struct compress_tree_node*)
176 regional_alloc(region, sizeof(struct compress_tree_node));
188 * Store domain name and ancestors into compression tree.
189 * @param dname: pointer to uncompressed dname (stored in tree).
190 * @param labs: number of labels in dname.
191 * @param offset: offset into packet for dname.
192 * @param region: how to allocate memory for new node.
193 * @param closest: match from previous lookup, used to compress dname.
194 * may be NULL if no previous match.
195 * if the tree has an ancestor of dname already, this must be it.
196 * @param insertpt: where to insert the dname in tree.
197 * @return: 0 on memory error.
200 compress_tree_store(uint8_t* dname, int labs, size_t offset,
201 struct regional* region, struct compress_tree_node* closest,
202 struct compress_tree_node** insertpt)
205 struct compress_tree_node* newnode;
206 struct compress_tree_node* prevnode = NULL;
207 int uplabs = labs-1; /* does not store root in tree */
208 if(closest) uplabs = labs - closest->labs;
209 log_assert(uplabs >= 0);
210 /* algorithms builds up a vine of dname-labels to hang into tree */
212 if(offset > PTR_MAX_OFFSET) {
213 /* insertion failed, drop vine */
214 return 1; /* compression pointer no longer useful */
216 if(!(newnode = compress_tree_newnode(dname, labs, offset,
218 /* insertion failed, drop vine */
223 /* chain nodes together, last one has one label more,
224 * so is larger than newnode, thus goes right. */
225 newnode->right = prevnode;
226 prevnode->parent = newnode;
236 /* if we have a vine, hang the vine into the tree */
238 *insertpt = prevnode;
239 prevnode->parent = closest;
244 /** compress a domain name */
246 write_compressed_dname(sldns_buffer* pkt, uint8_t* dname, int labs,
247 struct compress_tree_node* p)
250 int labcopy = labs - p->labs;
255 /* write root label */
256 if(sldns_buffer_remaining(pkt) < 1)
258 sldns_buffer_write_u8(pkt, 0);
262 /* copy the first couple of labels */
265 if(sldns_buffer_remaining(pkt) < (size_t)lablen+1)
267 sldns_buffer_write_u8(pkt, lablen);
268 sldns_buffer_write(pkt, dname, lablen);
271 /* insert compression ptr */
272 if(sldns_buffer_remaining(pkt) < 2)
274 ptr = PTR_CREATE(p->offset);
275 sldns_buffer_write_u16(pkt, ptr);
279 /** compress owner name of RR, return RETVAL_OUTMEM RETVAL_TRUNC */
281 compress_owner(struct ub_packed_rrset_key* key, sldns_buffer* pkt,
282 struct regional* region, struct compress_tree_node** tree,
283 size_t owner_pos, uint16_t* owner_ptr, int owner_labs)
285 struct compress_tree_node* p;
286 struct compress_tree_node** insertpt = NULL;
288 /* compress first time dname */
289 if((p = compress_tree_lookup(tree, key->rk.dname,
290 owner_labs, &insertpt))) {
291 if(p->labs == owner_labs)
292 /* avoid ptr chains, since some software is
293 * not capable of decoding ptr after a ptr. */
294 *owner_ptr = htons(PTR_CREATE(p->offset));
295 if(!write_compressed_dname(pkt, key->rk.dname,
298 /* check if typeclass+4 ttl + rdatalen is available */
299 if(sldns_buffer_remaining(pkt) < 4+4+2)
303 if(sldns_buffer_remaining(pkt) < key->rk.dname_len+4+4+2)
305 sldns_buffer_write(pkt, key->rk.dname,
307 if(owner_pos <= PTR_MAX_OFFSET)
308 *owner_ptr = htons(PTR_CREATE(owner_pos));
310 if(!compress_tree_store(key->rk.dname, owner_labs,
311 owner_pos, region, p, insertpt))
312 return RETVAL_OUTMEM;
314 /* always compress 2nd-further RRs in RRset */
315 if(owner_labs == 1) {
316 if(sldns_buffer_remaining(pkt) < 1+4+4+2)
318 sldns_buffer_write_u8(pkt, 0);
320 if(sldns_buffer_remaining(pkt) < 2+4+4+2)
322 sldns_buffer_write(pkt, owner_ptr, 2);
328 /** compress any domain name to the packet, return RETVAL_* */
330 compress_any_dname(uint8_t* dname, sldns_buffer* pkt, int labs,
331 struct regional* region, struct compress_tree_node** tree)
333 struct compress_tree_node* p;
334 struct compress_tree_node** insertpt = NULL;
335 size_t pos = sldns_buffer_position(pkt);
336 if((p = compress_tree_lookup(tree, dname, labs, &insertpt))) {
337 if(!write_compressed_dname(pkt, dname, labs, p))
340 if(!dname_buffer_write(pkt, dname))
343 if(!compress_tree_store(dname, labs, pos, region, p, insertpt))
344 return RETVAL_OUTMEM;
348 /** return true if type needs domain name compression in rdata */
349 static const sldns_rr_descriptor*
350 type_rdata_compressable(struct ub_packed_rrset_key* key)
352 uint16_t t = ntohs(key->rk.type);
353 if(sldns_rr_descript(t) &&
354 sldns_rr_descript(t)->_compress == LDNS_RR_COMPRESS)
355 return sldns_rr_descript(t);
359 /** compress domain names in rdata, return RETVAL_* */
361 compress_rdata(sldns_buffer* pkt, uint8_t* rdata, size_t todolen,
362 struct regional* region, struct compress_tree_node** tree,
363 const sldns_rr_descriptor* desc)
365 int labs, r, rdf = 0;
366 size_t dname_len, len, pos = sldns_buffer_position(pkt);
367 uint8_t count = desc->_dname_count;
369 sldns_buffer_skip(pkt, 2); /* rdata len fill in later */
370 /* space for rdatalen checked for already */
373 while(todolen > 0 && count) {
374 switch(desc->_wireformat[rdf]) {
375 case LDNS_RDF_TYPE_DNAME:
376 labs = dname_count_size_labels(rdata, &dname_len);
377 if((r=compress_any_dname(rdata, pkt, labs, region,
381 todolen -= dname_len;
385 case LDNS_RDF_TYPE_STR:
389 len = get_rdf_size(desc->_wireformat[rdf]);
393 if(sldns_buffer_remaining(pkt) < len)
395 sldns_buffer_write(pkt, rdata, len);
403 if(sldns_buffer_remaining(pkt) < todolen)
405 sldns_buffer_write(pkt, rdata, todolen);
409 sldns_buffer_write_u16_at(pkt, pos, sldns_buffer_position(pkt)-pos-2);
413 /** Returns true if RR type should be included */
415 rrset_belongs_in_reply(sldns_pkt_section s, uint16_t rrtype, uint16_t qtype,
420 /* skip non DNSSEC types, except if directly queried for */
421 if(s == LDNS_SECTION_ANSWER) {
422 if(qtype == LDNS_RR_TYPE_ANY || qtype == rrtype)
425 /* check DNSSEC-ness */
427 case LDNS_RR_TYPE_SIG:
428 case LDNS_RR_TYPE_KEY:
429 case LDNS_RR_TYPE_NXT:
430 case LDNS_RR_TYPE_DS:
431 case LDNS_RR_TYPE_RRSIG:
432 case LDNS_RR_TYPE_NSEC:
433 case LDNS_RR_TYPE_DNSKEY:
434 case LDNS_RR_TYPE_NSEC3:
435 case LDNS_RR_TYPE_NSEC3PARAMS:
441 /** store rrset in buffer in wireformat, return RETVAL_* */
443 packed_rrset_encode(struct ub_packed_rrset_key* key, sldns_buffer* pkt,
444 uint16_t* num_rrs, time_t timenow, struct regional* region,
445 int do_data, int do_sig, struct compress_tree_node** tree,
446 sldns_pkt_section s, uint16_t qtype, int dnssec, size_t rr_offset)
448 size_t i, j, owner_pos;
450 uint16_t owner_ptr = 0;
451 struct packed_rrset_data* data = (struct packed_rrset_data*)
454 /* does this RR type belong in the answer? */
455 if(!rrset_belongs_in_reply(s, ntohs(key->rk.type), qtype, dnssec))
458 owner_labs = dname_count_labels(key->rk.dname);
459 owner_pos = sldns_buffer_position(pkt);
462 const sldns_rr_descriptor* c = type_rdata_compressable(key);
463 for(i=0; i<data->count; i++) {
464 /* rrset roundrobin */
465 j = (i + rr_offset) % data->count;
466 if((r=compress_owner(key, pkt, region, tree,
467 owner_pos, &owner_ptr, owner_labs))
470 sldns_buffer_write(pkt, &key->rk.type, 2);
471 sldns_buffer_write(pkt, &key->rk.rrset_class, 2);
472 if(data->rr_ttl[j] < timenow)
473 sldns_buffer_write_u32(pkt, 0);
474 else sldns_buffer_write_u32(pkt,
475 data->rr_ttl[j]-timenow);
477 if((r=compress_rdata(pkt, data->rr_data[j],
478 data->rr_len[j], region, tree, c))
482 if(sldns_buffer_remaining(pkt) < data->rr_len[j])
484 sldns_buffer_write(pkt, data->rr_data[j],
490 if(do_sig && dnssec) {
491 size_t total = data->count+data->rrsig_count;
492 for(i=data->count; i<total; i++) {
493 if(owner_ptr && owner_labs != 1) {
494 if(sldns_buffer_remaining(pkt) <
495 2+4+4+data->rr_len[i])
497 sldns_buffer_write(pkt, &owner_ptr, 2);
499 if((r=compress_any_dname(key->rk.dname,
500 pkt, owner_labs, region, tree))
503 if(sldns_buffer_remaining(pkt) <
507 sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_RRSIG);
508 sldns_buffer_write(pkt, &key->rk.rrset_class, 2);
509 if(data->rr_ttl[i] < timenow)
510 sldns_buffer_write_u32(pkt, 0);
511 else sldns_buffer_write_u32(pkt,
512 data->rr_ttl[i]-timenow);
513 /* rrsig rdata cannot be compressed, perform 100+ byte
515 sldns_buffer_write(pkt, data->rr_data[i],
519 /* change rrnum only after we are sure it fits */
521 *num_rrs += data->count;
523 *num_rrs += data->rrsig_count;
528 /** store msg section in wireformat buffer, return RETVAL_* */
530 insert_section(struct reply_info* rep, size_t num_rrsets, uint16_t* num_rrs,
531 sldns_buffer* pkt, size_t rrsets_before, time_t timenow,
532 struct regional* region, struct compress_tree_node** tree,
533 sldns_pkt_section s, uint16_t qtype, int dnssec, size_t rr_offset)
538 if(s != LDNS_SECTION_ADDITIONAL) {
539 if(s == LDNS_SECTION_ANSWER && qtype == LDNS_RR_TYPE_ANY)
540 dnssec = 1; /* include all types in ANY answer */
541 for(i=0; i<num_rrsets; i++) {
542 setstart = sldns_buffer_position(pkt);
543 if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i],
544 pkt, num_rrs, timenow, region, 1, 1, tree,
545 s, qtype, dnssec, rr_offset))
547 /* Bad, but if due to size must set TC bit */
548 /* trim off the rrset neatly. */
549 sldns_buffer_set_position(pkt, setstart);
554 for(i=0; i<num_rrsets; i++) {
555 setstart = sldns_buffer_position(pkt);
556 if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i],
557 pkt, num_rrs, timenow, region, 1, 0, tree,
558 s, qtype, dnssec, rr_offset))
560 sldns_buffer_set_position(pkt, setstart);
565 for(i=0; i<num_rrsets; i++) {
566 setstart = sldns_buffer_position(pkt);
567 if((r=packed_rrset_encode(rep->rrsets[rrsets_before+i],
568 pkt, num_rrs, timenow, region, 0, 1, tree,
569 s, qtype, dnssec, rr_offset))
571 sldns_buffer_set_position(pkt, setstart);
579 /** store query section in wireformat buffer, return RETVAL */
581 insert_query(struct query_info* qinfo, struct compress_tree_node** tree,
582 sldns_buffer* buffer, struct regional* region)
584 if(sldns_buffer_remaining(buffer) <
585 qinfo->qname_len+sizeof(uint16_t)*2)
586 return RETVAL_TRUNC; /* buffer too small */
587 /* the query is the first name inserted into the tree */
588 if(!compress_tree_store(qinfo->qname,
589 dname_count_labels(qinfo->qname),
590 sldns_buffer_position(buffer), region, NULL, tree))
591 return RETVAL_OUTMEM;
592 if(sldns_buffer_current(buffer) == qinfo->qname)
593 sldns_buffer_skip(buffer, (ssize_t)qinfo->qname_len);
594 else sldns_buffer_write(buffer, qinfo->qname, qinfo->qname_len);
595 sldns_buffer_write_u16(buffer, qinfo->qtype);
596 sldns_buffer_write_u16(buffer, qinfo->qclass);
601 positive_answer(struct reply_info* rep, uint16_t qtype) {
603 if (FLAGS_GET_RCODE(rep->flags) != LDNS_RCODE_NOERROR)
606 for(i=0;i<rep->an_numrrsets; i++) {
607 if(ntohs(rep->rrsets[i]->rk.type) == qtype) {
608 /* in case it is a wildcard with DNSSEC, there will
609 * be NSEC/NSEC3 records in the authority section
610 * that we cannot remove */
611 for(i=rep->an_numrrsets; i<rep->an_numrrsets+
612 rep->ns_numrrsets; i++) {
613 if(ntohs(rep->rrsets[i]->rk.type) ==
615 ntohs(rep->rrsets[i]->rk.type) ==
626 reply_info_encode(struct query_info* qinfo, struct reply_info* rep,
627 uint16_t id, uint16_t flags, sldns_buffer* buffer, time_t timenow,
628 struct regional* region, uint16_t udpsize, int dnssec)
630 uint16_t ancount=0, nscount=0, arcount=0;
631 struct compress_tree_node* tree = 0;
635 sldns_buffer_clear(buffer);
636 if(udpsize < sldns_buffer_limit(buffer))
637 sldns_buffer_set_limit(buffer, udpsize);
638 if(sldns_buffer_remaining(buffer) < LDNS_HEADER_SIZE)
641 sldns_buffer_write(buffer, &id, sizeof(uint16_t));
642 sldns_buffer_write_u16(buffer, flags);
643 sldns_buffer_write_u16(buffer, rep->qdcount);
644 /* set an, ns, ar counts to zero in case of small packets */
645 sldns_buffer_write(buffer, "\000\000\000\000\000\000", 6);
647 /* insert query section */
649 if((r=insert_query(qinfo, &tree, buffer, region)) !=
651 if(r == RETVAL_TRUNC) {
652 /* create truncated message */
653 sldns_buffer_write_u16_at(buffer, 4, 0);
654 LDNS_TC_SET(sldns_buffer_begin(buffer));
655 sldns_buffer_flip(buffer);
661 /* roundrobin offset. using query id for random number. With ntohs
662 * for different roundrobins for sequential id client senders. */
663 rr_offset = RRSET_ROUNDROBIN?ntohs(id):0;
665 /* insert answer section */
666 if((r=insert_section(rep, rep->an_numrrsets, &ancount, buffer,
667 0, timenow, region, &tree, LDNS_SECTION_ANSWER, qinfo->qtype,
668 dnssec, rr_offset)) != RETVAL_OK) {
669 if(r == RETVAL_TRUNC) {
670 /* create truncated message */
671 sldns_buffer_write_u16_at(buffer, 6, ancount);
672 LDNS_TC_SET(sldns_buffer_begin(buffer));
673 sldns_buffer_flip(buffer);
678 sldns_buffer_write_u16_at(buffer, 6, ancount);
680 /* if response is positive answer, auth/add sections are not required */
681 if( ! (MINIMAL_RESPONSES && positive_answer(rep, qinfo->qtype)) ) {
682 /* insert auth section */
683 if((r=insert_section(rep, rep->ns_numrrsets, &nscount, buffer,
684 rep->an_numrrsets, timenow, region, &tree,
685 LDNS_SECTION_AUTHORITY, qinfo->qtype,
686 dnssec, rr_offset)) != RETVAL_OK) {
687 if(r == RETVAL_TRUNC) {
688 /* create truncated message */
689 sldns_buffer_write_u16_at(buffer, 8, nscount);
690 LDNS_TC_SET(sldns_buffer_begin(buffer));
691 sldns_buffer_flip(buffer);
696 sldns_buffer_write_u16_at(buffer, 8, nscount);
698 /* insert add section */
699 if((r=insert_section(rep, rep->ar_numrrsets, &arcount, buffer,
700 rep->an_numrrsets + rep->ns_numrrsets, timenow, region,
701 &tree, LDNS_SECTION_ADDITIONAL, qinfo->qtype,
702 dnssec, rr_offset)) != RETVAL_OK) {
703 if(r == RETVAL_TRUNC) {
704 /* no need to set TC bit, this is the additional */
705 sldns_buffer_write_u16_at(buffer, 10, arcount);
706 sldns_buffer_flip(buffer);
711 sldns_buffer_write_u16_at(buffer, 10, arcount);
713 sldns_buffer_flip(buffer);
718 calc_edns_field_size(struct edns_data* edns)
721 struct edns_option* opt;
722 if(!edns || !edns->edns_present)
724 for(opt = edns->opt_list; opt; opt = opt->next) {
725 rdatalen += 4 + opt->opt_len;
727 /* domain root '.' + type + class + ttl + rdatalen */
728 return 1 + 2 + 2 + 4 + 2 + rdatalen;
732 attach_edns_record(sldns_buffer* pkt, struct edns_data* edns)
736 struct edns_option* opt;
737 if(!edns || !edns->edns_present)
739 /* inc additional count */
740 sldns_buffer_write_u16_at(pkt, 10,
741 sldns_buffer_read_u16_at(pkt, 10) + 1);
742 len = sldns_buffer_limit(pkt);
743 sldns_buffer_clear(pkt);
744 sldns_buffer_set_position(pkt, len);
745 /* write EDNS record */
746 sldns_buffer_write_u8(pkt, 0); /* '.' label */
747 sldns_buffer_write_u16(pkt, LDNS_RR_TYPE_OPT); /* type */
748 sldns_buffer_write_u16(pkt, edns->udp_size); /* class */
749 sldns_buffer_write_u8(pkt, edns->ext_rcode); /* ttl */
750 sldns_buffer_write_u8(pkt, edns->edns_version);
751 sldns_buffer_write_u16(pkt, edns->bits);
752 rdatapos = sldns_buffer_position(pkt);
753 sldns_buffer_write_u16(pkt, 0); /* rdatalen */
755 for(opt=edns->opt_list; opt; opt=opt->next) {
756 sldns_buffer_write_u16(pkt, opt->opt_code);
757 sldns_buffer_write_u16(pkt, opt->opt_len);
758 if(opt->opt_len != 0)
759 sldns_buffer_write(pkt, opt->opt_data, opt->opt_len);
762 sldns_buffer_write_u16_at(pkt, rdatapos,
763 sldns_buffer_position(pkt)-rdatapos-2);
764 sldns_buffer_flip(pkt);
768 reply_info_answer_encode(struct query_info* qinf, struct reply_info* rep,
769 uint16_t id, uint16_t qflags, sldns_buffer* pkt, time_t timenow,
770 int cached, struct regional* region, uint16_t udpsize,
771 struct edns_data* edns, int dnssec, int secure)
776 if(!cached || rep->authoritative) {
777 /* original flags, copy RD and CD bits from query. */
778 flags = rep->flags | (qflags & (BIT_RD|BIT_CD));
780 /* remove AA bit, copy RD and CD bits from query. */
781 flags = (rep->flags & ~BIT_AA) | (qflags & (BIT_RD|BIT_CD));
783 if(secure && (dnssec || (qflags&BIT_AD)))
785 log_assert(flags & BIT_QR); /* QR bit must be on in our replies */
786 if(udpsize < LDNS_HEADER_SIZE)
788 if(udpsize < LDNS_HEADER_SIZE + calc_edns_field_size(edns)) {
789 /* packet too small to contain edns, omit it. */
792 /* reserve space for edns record */
793 udpsize -= calc_edns_field_size(edns);
796 if(!reply_info_encode(qinf, rep, id, flags, pkt, timenow, region,
798 log_err("reply encode: out of memory");
802 attach_edns_record(pkt, edns);
807 qinfo_query_encode(sldns_buffer* pkt, struct query_info* qinfo)
809 uint16_t flags = 0; /* QUERY, NOERROR */
810 sldns_buffer_clear(pkt);
811 log_assert(sldns_buffer_remaining(pkt) >= 12+255+4/*max query*/);
812 sldns_buffer_skip(pkt, 2); /* id done later */
813 sldns_buffer_write_u16(pkt, flags);
814 sldns_buffer_write_u16(pkt, 1); /* query count */
815 sldns_buffer_write(pkt, "\000\000\000\000\000\000", 6); /* counts */
816 sldns_buffer_write(pkt, qinfo->qname, qinfo->qname_len);
817 sldns_buffer_write_u16(pkt, qinfo->qtype);
818 sldns_buffer_write_u16(pkt, qinfo->qclass);
819 sldns_buffer_flip(pkt);
823 error_encode(sldns_buffer* buf, int r, struct query_info* qinfo,
824 uint16_t qid, uint16_t qflags, struct edns_data* edns)
828 sldns_buffer_clear(buf);
829 sldns_buffer_write(buf, &qid, sizeof(uint16_t));
830 flags = (uint16_t)(BIT_QR | BIT_RA | r); /* QR and retcode*/
831 flags |= (qflags & (BIT_RD|BIT_CD)); /* copy RD and CD bit */
832 sldns_buffer_write_u16(buf, flags);
835 sldns_buffer_write_u16(buf, flags);
837 sldns_buffer_write(buf, &flags, sizeof(uint16_t));
838 sldns_buffer_write(buf, &flags, sizeof(uint16_t));
839 sldns_buffer_write(buf, &flags, sizeof(uint16_t));
841 if(sldns_buffer_current(buf) == qinfo->qname)
842 sldns_buffer_skip(buf, (ssize_t)qinfo->qname_len);
843 else sldns_buffer_write(buf, qinfo->qname, qinfo->qname_len);
844 sldns_buffer_write_u16(buf, qinfo->qtype);
845 sldns_buffer_write_u16(buf, qinfo->qclass);
847 sldns_buffer_flip(buf);
849 struct edns_data es = *edns;
850 es.edns_version = EDNS_ADVERTISED_VERSION;
851 es.udp_size = EDNS_ADVERTISED_SIZE;
854 if(sldns_buffer_limit(buf) + calc_edns_field_size(&es) >
857 attach_edns_record(buf, &es);