2 * iterator/iter_scrub.c - scrubbing, normalization, sanitization of DNS msgs.
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 LIMITED
25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
39 * This file has routine(s) for cleaning up incoming DNS messages from
40 * possible useless or malicious junk in it.
43 #include "iterator/iter_scrub.h"
44 #include "iterator/iterator.h"
45 #include "iterator/iter_priv.h"
46 #include "services/cache/rrset.h"
48 #include "util/net_help.h"
49 #include "util/regional.h"
50 #include "util/config_file.h"
51 #include "util/module.h"
52 #include "util/data/msgparse.h"
53 #include "util/data/dname.h"
54 #include "util/data/msgreply.h"
55 #include "util/alloc.h"
57 /** RRset flag used during scrubbing. The RRset is OK. */
58 #define RRSET_SCRUB_OK 0x80
60 /** remove rrset, update loop variables */
62 remove_rrset(const char* str, ldns_buffer* pkt, struct msg_parse* msg,
63 struct rrset_parse* prev, struct rrset_parse** rrset)
65 if(verbosity >= VERB_QUERY && str
66 && (*rrset)->dname_len <= LDNS_MAX_DOMAINLEN) {
67 uint8_t buf[LDNS_MAX_DOMAINLEN+1];
68 dname_pkt_copy(pkt, buf, (*rrset)->dname);
69 log_nametypeclass(VERB_QUERY, str, buf,
70 (*rrset)->type, ntohs((*rrset)->rrset_class));
73 prev->rrset_all_next = (*rrset)->rrset_all_next;
74 else msg->rrset_first = (*rrset)->rrset_all_next;
75 if(msg->rrset_last == *rrset)
76 msg->rrset_last = prev;
78 switch((*rrset)->section) {
79 case LDNS_SECTION_ANSWER: msg->an_rrsets--; break;
80 case LDNS_SECTION_AUTHORITY: msg->ns_rrsets--; break;
81 case LDNS_SECTION_ADDITIONAL: msg->ar_rrsets--; break;
82 default: log_assert(0);
84 msgparse_bucket_remove(msg, *rrset);
85 *rrset = (*rrset)->rrset_all_next;
88 /** return true if rr type has additional names in it */
90 has_additional(uint16_t t)
99 case LDNS_RR_TYPE_SRV:
101 case LDNS_RR_TYPE_NAPTR:
102 /* TODO: NAPTR not supported, glue stripped off */
108 /** get additional name from rrset RR, return false if no name present */
110 get_additional_name(struct rrset_parse* rrset, struct rr_parse* rr,
111 uint8_t** nm, size_t* nmlen, ldns_buffer* pkt)
115 switch(rrset->type) {
116 case LDNS_RR_TYPE_MB:
117 case LDNS_RR_TYPE_MD:
118 case LDNS_RR_TYPE_MF:
119 case LDNS_RR_TYPE_NS:
122 case LDNS_RR_TYPE_MX:
123 case LDNS_RR_TYPE_KX:
126 case LDNS_RR_TYPE_SRV:
129 case LDNS_RR_TYPE_NAPTR:
130 /* TODO: NAPTR not supported, glue stripped off */
135 len = ldns_read_uint16(rr->ttl_data+sizeof(uint32_t));
137 return 0; /* rdata field too small */
138 *nm = rr->ttl_data+sizeof(uint32_t)+sizeof(uint16_t)+offset;
139 oldpos = ldns_buffer_position(pkt);
140 ldns_buffer_set_position(pkt, (size_t)(*nm - ldns_buffer_begin(pkt)));
141 *nmlen = pkt_dname_len(pkt);
142 ldns_buffer_set_position(pkt, oldpos);
148 /** Place mark on rrsets in additional section they are OK */
150 mark_additional_rrset(ldns_buffer* pkt, struct msg_parse* msg,
151 struct rrset_parse* rrset)
153 /* Mark A and AAAA for NS as appropriate additional section info. */
158 if(!has_additional(rrset->type))
160 for(rr = rrset->rr_first; rr; rr = rr->next) {
161 if(get_additional_name(rrset, rr, &nm, &nmlen, pkt)) {
163 hashvalue_t h = pkt_hash_rrset(pkt, nm, LDNS_RR_TYPE_A,
164 rrset->rrset_class, 0);
165 struct rrset_parse* r = msgparse_hashtable_lookup(
166 msg, pkt, h, 0, nm, nmlen,
167 LDNS_RR_TYPE_A, rrset->rrset_class);
168 if(r && r->section == LDNS_SECTION_ADDITIONAL) {
169 r->flags |= RRSET_SCRUB_OK;
173 h = pkt_hash_rrset(pkt, nm, LDNS_RR_TYPE_AAAA,
174 rrset->rrset_class, 0);
175 r = msgparse_hashtable_lookup(msg, pkt, h, 0, nm,
176 nmlen, LDNS_RR_TYPE_AAAA, rrset->rrset_class);
177 if(r && r->section == LDNS_SECTION_ADDITIONAL) {
178 r->flags |= RRSET_SCRUB_OK;
184 /** Get target name of a CNAME */
186 parse_get_cname_target(struct rrset_parse* rrset, uint8_t** sname,
189 if(rrset->rr_count != 1) {
190 struct rr_parse* sig;
191 verbose(VERB_ALGO, "Found CNAME rrset with "
192 "size > 1: %u", (unsigned)rrset->rr_count);
193 /* use the first CNAME! */
195 rrset->size = rrset->rr_first->size;
196 for(sig=rrset->rrsig_first; sig; sig=sig->next)
197 rrset->size += sig->size;
198 rrset->rr_last = rrset->rr_first;
199 rrset->rr_first->next = NULL;
201 if(rrset->rr_first->size < sizeof(uint16_t)+1)
202 return 0; /* CNAME rdata too small */
203 *sname = rrset->rr_first->ttl_data + sizeof(uint32_t)
204 + sizeof(uint16_t); /* skip ttl, rdatalen */
205 *snamelen = rrset->rr_first->size - sizeof(uint16_t);
209 /** Synthesize CNAME from DNAME, false if too long */
211 synth_cname(uint8_t* qname, size_t qnamelen, struct rrset_parse* dname_rrset,
212 uint8_t* alias, size_t* aliaslen, ldns_buffer* pkt)
214 /* we already know that sname is a strict subdomain of DNAME owner */
215 uint8_t* dtarg = NULL;
217 if(!parse_get_cname_target(dname_rrset, &dtarg, &dtarglen))
219 log_assert(qnamelen > dname_rrset->dname_len);
220 /* DNAME from com. to net. with qname example.com. -> example.net. */
221 /* so: \3com\0 to \3net\0 and qname \7example\3com\0 */
222 *aliaslen = qnamelen + dtarglen - dname_rrset->dname_len;
223 if(*aliaslen > LDNS_MAX_DOMAINLEN)
224 return 0; /* should have been RCODE YXDOMAIN */
225 /* decompress dnames into buffer, we know it fits */
226 dname_pkt_copy(pkt, alias, qname);
227 dname_pkt_copy(pkt, alias+(qnamelen-dname_rrset->dname_len), dtarg);
231 /** synthesize a CNAME rrset */
232 static struct rrset_parse*
233 synth_cname_rrset(uint8_t** sname, size_t* snamelen, uint8_t* alias,
234 size_t aliaslen, struct regional* region, struct msg_parse* msg,
235 struct rrset_parse* rrset, struct rrset_parse* prev,
236 struct rrset_parse* nx, ldns_buffer* pkt)
238 struct rrset_parse* cn = (struct rrset_parse*)regional_alloc(region,
239 sizeof(struct rrset_parse));
242 memset(cn, 0, sizeof(*cn));
243 cn->rr_first = (struct rr_parse*)regional_alloc(region,
244 sizeof(struct rr_parse));
247 cn->rr_last = cn->rr_first;
248 /* CNAME from sname to alias */
249 cn->dname = (uint8_t*)regional_alloc(region, *snamelen);
252 dname_pkt_copy(pkt, cn->dname, *sname);
253 cn->dname_len = *snamelen;
254 cn->type = LDNS_RR_TYPE_CNAME;
255 cn->section = rrset->section;
256 cn->rrset_class = rrset->rrset_class;
258 cn->size = sizeof(uint16_t) + aliaslen;
259 cn->hash=pkt_hash_rrset(pkt, cn->dname, cn->type, cn->rrset_class, 0);
260 /* allocate TTL + rdatalen + uncompressed dname */
261 memset(cn->rr_first, 0, sizeof(struct rr_parse));
262 cn->rr_first->outside_packet = 1;
263 cn->rr_first->ttl_data = (uint8_t*)regional_alloc(region,
264 sizeof(uint32_t)+sizeof(uint16_t)+aliaslen);
265 if(!cn->rr_first->ttl_data)
267 ldns_write_uint32(cn->rr_first->ttl_data, 0); /* TTL = 0 */
268 ldns_write_uint16(cn->rr_first->ttl_data+4, aliaslen);
269 memmove(cn->rr_first->ttl_data+6, alias, aliaslen);
270 cn->rr_first->size = sizeof(uint16_t)+aliaslen;
273 cn->rrset_all_next = nx;
275 prev->rrset_all_next = cn;
276 else msg->rrset_first = cn;
278 msg->rrset_last = cn;
281 /* it is not inserted in the msg hashtable. */
283 *sname = cn->rr_first->ttl_data + sizeof(uint32_t)+sizeof(uint16_t);
284 *snamelen = aliaslen;
288 /** check if DNAME applies to a name */
290 pkt_strict_sub(ldns_buffer* pkt, uint8_t* sname, uint8_t* dr)
292 uint8_t buf1[LDNS_MAX_DOMAINLEN+1];
293 uint8_t buf2[LDNS_MAX_DOMAINLEN+1];
294 /* decompress names */
295 dname_pkt_copy(pkt, buf1, sname);
296 dname_pkt_copy(pkt, buf2, dr);
297 return dname_strict_subdomain_c(buf1, buf2);
300 /** check subdomain with decompression */
302 pkt_sub(ldns_buffer* pkt, uint8_t* comprname, uint8_t* zone)
304 uint8_t buf[LDNS_MAX_DOMAINLEN+1];
305 dname_pkt_copy(pkt, buf, comprname);
306 return dname_subdomain_c(buf, zone);
309 /** check subdomain with decompression, compressed is parent */
311 sub_of_pkt(ldns_buffer* pkt, uint8_t* zone, uint8_t* comprname)
313 uint8_t buf[LDNS_MAX_DOMAINLEN+1];
314 dname_pkt_copy(pkt, buf, comprname);
315 return dname_subdomain_c(zone, buf);
319 * This routine normalizes a response. This includes removing "irrelevant"
320 * records from the answer and additional sections and (re)synthesizing
321 * CNAMEs from DNAMEs, if present.
323 * @param pkt: packet.
324 * @param msg: msg to normalize.
325 * @param qinfo: original query.
326 * @param region: where to allocate synthesized CNAMEs.
327 * @return 0 on error.
330 scrub_normalize(ldns_buffer* pkt, struct msg_parse* msg,
331 struct query_info* qinfo, struct regional* region)
333 uint8_t* sname = qinfo->qname;
334 size_t snamelen = qinfo->qname_len;
335 struct rrset_parse* rrset, *prev, *nsset=NULL;
337 if(FLAGS_GET_RCODE(msg->flags) != LDNS_RCODE_NOERROR &&
338 FLAGS_GET_RCODE(msg->flags) != LDNS_RCODE_NXDOMAIN)
341 /* For the ANSWER section, remove all "irrelevant" records and add
342 * synthesized CNAMEs from DNAMEs
343 * This will strip out-of-order CNAMEs as well. */
345 /* walk through the parse packet rrset list, keep track of previous
346 * for insert and delete ease, and examine every RRset */
348 rrset = msg->rrset_first;
349 while(rrset && rrset->section == LDNS_SECTION_ANSWER) {
350 if(rrset->type == LDNS_RR_TYPE_DNAME &&
351 pkt_strict_sub(pkt, sname, rrset->dname)) {
352 /* check if next rrset is correct CNAME. else,
353 * synthesize a CNAME */
354 struct rrset_parse* nx = rrset->rrset_all_next;
355 uint8_t alias[LDNS_MAX_DOMAINLEN+1];
357 if(rrset->rr_count != 1) {
358 verbose(VERB_ALGO, "Found DNAME rrset with "
360 (unsigned)rrset->rr_count);
363 if(!synth_cname(sname, snamelen, rrset, alias,
365 verbose(VERB_ALGO, "synthesized CNAME "
369 if(nx && nx->type == LDNS_RR_TYPE_CNAME &&
370 dname_pkt_compare(pkt, sname, nx->dname) == 0) {
371 /* check next cname */
374 if(!parse_get_cname_target(rrset, &t, &tlen))
376 if(dname_pkt_compare(pkt, alias, t) == 0) {
377 /* it's OK and better capitalized */
382 /* synth ourselves */
384 /* synth a CNAME rrset */
385 prev = synth_cname_rrset(&sname, &snamelen, alias,
386 aliaslen, region, msg, rrset, rrset, nx, pkt);
388 log_err("out of memory synthesizing CNAME");
391 /* FIXME: resolve the conflict between synthesized
392 * CNAME ttls and the cache. */
398 /* The only records in the ANSWER section not allowed to */
399 if(dname_pkt_compare(pkt, sname, rrset->dname) != 0) {
400 remove_rrset("normalize: removing irrelevant RRset:",
401 pkt, msg, prev, &rrset);
405 /* Follow the CNAME chain. */
406 if(rrset->type == LDNS_RR_TYPE_CNAME) {
407 uint8_t* oldsname = sname;
408 if(!parse_get_cname_target(rrset, &sname, &snamelen))
411 rrset = rrset->rrset_all_next;
412 /* in CNAME ANY response, can have data after CNAME */
413 if(qinfo->qtype == LDNS_RR_TYPE_ANY) {
414 while(rrset && rrset->section ==
415 LDNS_SECTION_ANSWER &&
416 dname_pkt_compare(pkt, oldsname,
417 rrset->dname) == 0) {
419 rrset = rrset->rrset_all_next;
425 /* Otherwise, make sure that the RRset matches the qtype. */
426 if(qinfo->qtype != LDNS_RR_TYPE_ANY &&
427 qinfo->qtype != rrset->type) {
428 remove_rrset("normalize: removing irrelevant RRset:",
429 pkt, msg, prev, &rrset);
433 /* Mark the additional names from relevant rrset as OK. */
434 /* only for RRsets that match the query name, other ones
435 * will be removed by sanitize, so no additional for them */
436 if(dname_pkt_compare(pkt, qinfo->qname, rrset->dname) == 0)
437 mark_additional_rrset(pkt, msg, rrset);
440 rrset = rrset->rrset_all_next;
443 /* Mark additional names from AUTHORITY */
444 while(rrset && rrset->section == LDNS_SECTION_AUTHORITY) {
445 if(rrset->type==LDNS_RR_TYPE_DNAME ||
446 rrset->type==LDNS_RR_TYPE_CNAME ||
447 rrset->type==LDNS_RR_TYPE_A ||
448 rrset->type==LDNS_RR_TYPE_AAAA) {
449 remove_rrset("normalize: removing irrelevant "
450 "RRset:", pkt, msg, prev, &rrset);
453 /* only one NS set allowed in authority section */
454 if(rrset->type==LDNS_RR_TYPE_NS) {
455 /* NS set must be pertinent to the query */
456 if(!sub_of_pkt(pkt, qinfo->qname, rrset->dname)) {
457 remove_rrset("normalize: removing irrelevant "
458 "RRset:", pkt, msg, prev, &rrset);
464 remove_rrset("normalize: removing irrelevant "
465 "RRset:", pkt, msg, prev, &rrset);
469 mark_additional_rrset(pkt, msg, rrset);
471 rrset = rrset->rrset_all_next;
474 /* For each record in the additional section, remove it if it is an
475 * address record and not in the collection of additional names
476 * found in ANSWER and AUTHORITY. */
477 /* These records have not been marked OK previously */
478 while(rrset && rrset->section == LDNS_SECTION_ADDITIONAL) {
479 /* FIXME: what about other types? */
480 if(rrset->type==LDNS_RR_TYPE_A ||
481 rrset->type==LDNS_RR_TYPE_AAAA)
483 if((rrset->flags & RRSET_SCRUB_OK)) {
484 /* remove flag to clean up flags variable */
485 rrset->flags &= ~RRSET_SCRUB_OK;
487 remove_rrset("normalize: removing irrelevant "
488 "RRset:", pkt, msg, prev, &rrset);
492 if(rrset->type==LDNS_RR_TYPE_DNAME ||
493 rrset->type==LDNS_RR_TYPE_CNAME ||
494 rrset->type==LDNS_RR_TYPE_NS) {
495 remove_rrset("normalize: removing irrelevant "
496 "RRset:", pkt, msg, prev, &rrset);
500 rrset = rrset->rrset_all_next;
507 * Store potential poison in the cache (only if hardening disabled).
508 * The rrset is stored in the cache but removed from the message.
509 * So that it will be used for infrastructure purposes, but not be
510 * returned to the client.
512 * @param msg: message parsed
513 * @param env: environment with cache
514 * @param rrset: to store.
517 store_rrset(ldns_buffer* pkt, struct msg_parse* msg, struct module_env* env,
518 struct rrset_parse* rrset)
520 struct ub_packed_rrset_key* k;
521 struct packed_rrset_data* d;
522 struct rrset_ref ref;
523 time_t now = *env->now;
525 k = alloc_special_obtain(env->alloc);
528 k->entry.data = NULL;
529 if(!parse_copy_decompress_rrset(pkt, msg, rrset, NULL, k)) {
530 alloc_special_release(env->alloc, k);
533 d = (struct packed_rrset_data*)k->entry.data;
534 packed_rrset_ttl_add(d, now);
537 /*ignore ret: it was in the cache, ref updated */
538 (void)rrset_cache_update(env->rrset_cache, &ref, env->alloc, now);
541 /** Check if there are SOA records in the authority section (negative) */
543 soa_in_auth(struct msg_parse* msg)
545 struct rrset_parse* rrset;
546 for(rrset = msg->rrset_first; rrset; rrset = rrset->rrset_all_next)
547 if(rrset->type == LDNS_RR_TYPE_SOA &&
548 rrset->section == LDNS_SECTION_AUTHORITY)
554 * Check if right hand name in NSEC is within zone
555 * @param rrset: the NSEC rrset
556 * @param zonename: the zone name.
557 * @return true if BAD.
559 static int sanitize_nsec_is_overreach(struct rrset_parse* rrset,
565 log_assert(rrset->type == LDNS_RR_TYPE_NSEC);
566 for(rr = rrset->rr_first; rr; rr = rr->next) {
567 rhs = rr->ttl_data+4+2;
568 len = ldns_read_uint16(rr->ttl_data+4);
569 if(!dname_valid(rhs, len)) {
570 /* malformed domain name in rdata */
573 if(!dname_subdomain_c(rhs, zonename)) {
578 /* all NSEC RRs OK */
583 * Given a response event, remove suspect RRsets from the response.
584 * "Suspect" rrsets are potentially poison. Note that this routine expects
585 * the response to be in a "normalized" state -- that is, all "irrelevant"
586 * RRsets have already been removed, CNAMEs are in order, etc.
588 * @param pkt: packet.
589 * @param msg: msg to normalize.
590 * @param qinfo: the question originally asked.
591 * @param zonename: name of server zone.
592 * @param env: module environment with config and cache.
593 * @param ie: iterator environment with private address data.
594 * @return 0 on error.
597 scrub_sanitize(ldns_buffer* pkt, struct msg_parse* msg,
598 struct query_info* qinfo, uint8_t* zonename, struct module_env* env,
601 int del_addi = 0; /* if additional-holding rrsets are deleted, we
602 do not trust the normalized additional-A-AAAA any more */
603 struct rrset_parse* rrset, *prev;
605 rrset = msg->rrset_first;
607 /* the first DNAME is allowed to stay. It needs checking before
608 * it can be used from the cache. After normalization, an initial
609 * DNAME will have a correctly synthesized CNAME after it. */
610 if(rrset && rrset->type == LDNS_RR_TYPE_DNAME &&
611 rrset->section == LDNS_SECTION_ANSWER &&
612 pkt_strict_sub(pkt, qinfo->qname, rrset->dname) &&
613 pkt_sub(pkt, rrset->dname, zonename)) {
614 prev = rrset; /* DNAME allowed to stay in answer section */
615 rrset = rrset->rrset_all_next;
618 /* remove all records from the answer section that are
619 * not the same domain name as the query domain name.
620 * The answer section should contain rrsets with the same name
621 * as the question. For DNAMEs a CNAME has been synthesized.
622 * Wildcards have the query name in answer section.
623 * ANY queries get query name in answer section.
624 * Remainders of CNAME chains are cut off and resolved by iterator. */
625 while(rrset && rrset->section == LDNS_SECTION_ANSWER) {
626 if(dname_pkt_compare(pkt, qinfo->qname, rrset->dname) != 0) {
627 if(has_additional(rrset->type)) del_addi = 1;
628 remove_rrset("sanitize: removing extraneous answer "
629 "RRset:", pkt, msg, prev, &rrset);
633 rrset = rrset->rrset_all_next;
636 /* At this point, we brutally remove ALL rrsets that aren't
637 * children of the originating zone. The idea here is that,
638 * as far as we know, the server that we contacted is ONLY
639 * authoritative for the originating zone. It, of course, MAY
640 * be authoriative for any other zones, and of course, MAY
641 * NOT be authoritative for some subdomains of the originating
644 rrset = msg->rrset_first;
647 /* remove private addresses */
648 if( (rrset->type == LDNS_RR_TYPE_A ||
649 rrset->type == LDNS_RR_TYPE_AAAA)) {
651 /* do not set servfail since this leads to too
652 * many drops of other people using rfc1918 space */
653 /* also do not remove entire rrset, unless all records
655 if(priv_rrset_bad(ie->priv, pkt, rrset)) {
656 remove_rrset(NULL, pkt, msg, prev, &rrset);
661 /* skip DNAME records -- they will always be followed by a
662 * synthesized CNAME, which will be relevant.
663 * FIXME: should this do something differently with DNAME
664 * rrsets NOT in Section.ANSWER? */
665 /* But since DNAME records are also subdomains of the zone,
666 * same check can be used */
668 if(!pkt_sub(pkt, rrset->dname, zonename)) {
669 if(msg->an_rrsets == 0 &&
670 rrset->type == LDNS_RR_TYPE_NS &&
671 rrset->section == LDNS_SECTION_AUTHORITY &&
672 FLAGS_GET_RCODE(msg->flags) ==
673 LDNS_RCODE_NOERROR && !soa_in_auth(msg) &&
674 sub_of_pkt(pkt, zonename, rrset->dname)) {
675 /* noerror, nodata and this NS rrset is above
676 * the zone. This is LAME!
677 * Leave in the NS for lame classification. */
678 /* remove everything from the additional
679 * (we dont want its glue that was approved
680 * during the normalize action) */
682 } else if(!env->cfg->harden_glue) {
683 /* store in cache! Since it is relevant
684 * (from normalize) it will be picked up
685 * from the cache to be used later */
686 store_rrset(pkt, msg, env, rrset);
687 remove_rrset("sanitize: storing potential "
688 "poison RRset:", pkt, msg, prev, &rrset);
691 if(has_additional(rrset->type)) del_addi = 1;
692 remove_rrset("sanitize: removing potential "
693 "poison RRset:", pkt, msg, prev, &rrset);
697 if(del_addi && rrset->section == LDNS_SECTION_ADDITIONAL) {
698 remove_rrset("sanitize: removing potential "
699 "poison reference RRset:", pkt, msg, prev, &rrset);
702 /* check if right hand side of NSEC is within zone */
703 if(rrset->type == LDNS_RR_TYPE_NSEC &&
704 sanitize_nsec_is_overreach(rrset, zonename)) {
705 remove_rrset("sanitize: removing overreaching NSEC "
706 "RRset:", pkt, msg, prev, &rrset);
710 rrset = rrset->rrset_all_next;
716 scrub_message(ldns_buffer* pkt, struct msg_parse* msg,
717 struct query_info* qinfo, uint8_t* zonename, struct regional* region,
718 struct module_env* env, struct iter_env* ie)
720 /* basic sanity checks */
721 log_nametypeclass(VERB_ALGO, "scrub for", zonename, LDNS_RR_TYPE_NS,
725 if( !(msg->flags&BIT_QR) )
727 msg->flags &= ~(BIT_AD|BIT_Z); /* force off bit AD and Z */
729 /* make sure that a query is echoed back when NOERROR or NXDOMAIN */
730 /* this is not required for basic operation but is a forgery
731 * resistance (security) feature */
732 if((FLAGS_GET_RCODE(msg->flags) == LDNS_RCODE_NOERROR ||
733 FLAGS_GET_RCODE(msg->flags) == LDNS_RCODE_NXDOMAIN) &&
737 /* if a query is echoed back, make sure it is correct. Otherwise,
738 * this may be not a reply to our query. */
739 if(msg->qdcount == 1) {
740 if(dname_pkt_compare(pkt, msg->qname, qinfo->qname) != 0)
742 if(msg->qtype != qinfo->qtype || msg->qclass != qinfo->qclass)
746 /* normalize the response, this cleans up the additional. */
747 if(!scrub_normalize(pkt, msg, qinfo, region))
749 /* delete all out-of-zone information */
750 if(!scrub_sanitize(pkt, msg, qinfo, zonename, env, ie))