2 * validator/val_neg.c - validator aggressive negative caching functions.
4 * Copyright (c) 2008, 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 helper functions for the validator module.
40 * The functions help with aggressive negative caching.
41 * This creates new denials of existence, and proofs for absence of types
42 * from cached NSEC records.
45 #ifdef HAVE_OPENSSL_SSL_H
46 #include "openssl/ssl.h"
47 #define NSEC3_SHA_LEN SHA_DIGEST_LENGTH
49 #define NSEC3_SHA_LEN 20
51 #include "validator/val_neg.h"
52 #include "validator/val_nsec.h"
53 #include "validator/val_nsec3.h"
54 #include "validator/val_utils.h"
55 #include "util/data/dname.h"
56 #include "util/data/msgreply.h"
58 #include "util/net_help.h"
59 #include "util/config_file.h"
60 #include "services/cache/rrset.h"
61 #include "services/cache/dns.h"
62 #include "sldns/rrdef.h"
63 #include "sldns/sbuffer.h"
65 int val_neg_data_compare(const void* a, const void* b)
67 struct val_neg_data* x = (struct val_neg_data*)a;
68 struct val_neg_data* y = (struct val_neg_data*)b;
70 return dname_canon_lab_cmp(x->name, x->labs, y->name, y->labs, &m);
73 int val_neg_zone_compare(const void* a, const void* b)
75 struct val_neg_zone* x = (struct val_neg_zone*)a;
76 struct val_neg_zone* y = (struct val_neg_zone*)b;
78 if(x->dclass != y->dclass) {
79 if(x->dclass < y->dclass)
83 return dname_canon_lab_cmp(x->name, x->labs, y->name, y->labs, &m);
86 struct val_neg_cache* val_neg_create(struct config_file* cfg, size_t maxiter)
88 struct val_neg_cache* neg = (struct val_neg_cache*)calloc(1,
91 log_err("Could not create neg cache: out of memory");
94 neg->nsec3_max_iter = maxiter;
95 neg->max = 1024*1024; /* 1 M is thousands of entries */
96 if(cfg) neg->max = cfg->neg_cache_size;
97 rbtree_init(&neg->tree, &val_neg_zone_compare);
98 lock_basic_init(&neg->lock);
99 lock_protect(&neg->lock, neg, sizeof(*neg));
103 size_t val_neg_get_mem(struct val_neg_cache* neg)
106 lock_basic_lock(&neg->lock);
107 result = sizeof(*neg) + neg->use;
108 lock_basic_unlock(&neg->lock);
112 /** clear datas on cache deletion */
114 neg_clear_datas(rbnode_t* n, void* ATTR_UNUSED(arg))
116 struct val_neg_data* d = (struct val_neg_data*)n;
121 /** clear zones on cache deletion */
123 neg_clear_zones(rbnode_t* n, void* ATTR_UNUSED(arg))
125 struct val_neg_zone* z = (struct val_neg_zone*)n;
126 /* delete all the rrset entries in the tree */
127 traverse_postorder(&z->tree, &neg_clear_datas, NULL);
133 void neg_cache_delete(struct val_neg_cache* neg)
136 lock_basic_destroy(&neg->lock);
137 /* delete all the zones in the tree */
138 traverse_postorder(&neg->tree, &neg_clear_zones, NULL);
143 * Put data element at the front of the LRU list.
144 * @param neg: negative cache with LRU start and end.
145 * @param data: this data is fronted.
147 static void neg_lru_front(struct val_neg_cache* neg,
148 struct val_neg_data* data)
151 data->next = neg->first;
154 else neg->first->prev = data;
159 * Remove data element from LRU list.
160 * @param neg: negative cache with LRU start and end.
161 * @param data: this data is removed from the list.
163 static void neg_lru_remove(struct val_neg_cache* neg,
164 struct val_neg_data* data)
167 data->prev->next = data->next;
168 else neg->first = data->next;
170 data->next->prev = data->prev;
171 else neg->last = data->prev;
175 * Touch LRU for data element, put it at the start of the LRU list.
176 * @param neg: negative cache with LRU start and end.
177 * @param data: this data is used.
179 static void neg_lru_touch(struct val_neg_cache* neg,
180 struct val_neg_data* data)
182 if(data == neg->first)
183 return; /* nothing to do */
184 /* remove from current lru position */
185 neg_lru_remove(neg, data);
187 neg_lru_front(neg, data);
191 * Delete a zone element from the negative cache.
192 * May delete other zone elements to keep tree coherent, or
193 * only mark the element as 'not in use'.
194 * @param neg: negative cache.
195 * @param z: zone element to delete.
197 static void neg_delete_zone(struct val_neg_cache* neg, struct val_neg_zone* z)
199 struct val_neg_zone* p, *np;
201 log_assert(z->in_use);
202 log_assert(z->count > 0);
205 /* go up the tree and reduce counts */
208 log_assert(p->count > 0);
213 /* remove zones with zero count */
215 while(p && p->count == 0) {
217 (void)rbtree_delete(&neg->tree, &p->node);
218 neg->use -= p->len + sizeof(*p);
226 void neg_delete_data(struct val_neg_cache* neg, struct val_neg_data* el)
228 struct val_neg_zone* z;
229 struct val_neg_data* p, *np;
232 log_assert(el->in_use);
233 log_assert(el->count > 0);
236 /* remove it from the lru list */
237 neg_lru_remove(neg, el);
239 /* go up the tree and reduce counts */
242 log_assert(p->count > 0);
247 /* delete 0 count items from tree */
249 while(p && p->count == 0) {
251 (void)rbtree_delete(&z->tree, &p->node);
252 neg->use -= p->len + sizeof(*p);
258 /* check if the zone is now unused */
259 if(z->tree.count == 0) {
260 neg_delete_zone(neg, z);
265 * Create more space in negative cache
266 * The oldest elements are deleted until enough space is present.
267 * Empty zones are deleted.
268 * @param neg: negative cache.
269 * @param need: how many bytes are needed.
271 static void neg_make_space(struct val_neg_cache* neg, size_t need)
273 /* delete elements until enough space or its empty */
274 while(neg->last && neg->max < neg->use + need) {
275 neg_delete_data(neg, neg->last);
279 struct val_neg_zone* neg_find_zone(struct val_neg_cache* neg,
280 uint8_t* nm, size_t len, uint16_t dclass)
282 struct val_neg_zone lookfor;
283 struct val_neg_zone* result;
284 lookfor.node.key = &lookfor;
287 lookfor.labs = dname_count_labels(lookfor.name);
288 lookfor.dclass = dclass;
290 result = (struct val_neg_zone*)
291 rbtree_search(&neg->tree, lookfor.node.key);
296 * Find the given data
297 * @param zone: negative zone
298 * @param nm: what to look for.
299 * @param len: length of nm
300 * @param labs: labels in nm
301 * @return data or NULL if not found.
303 static struct val_neg_data* neg_find_data(struct val_neg_zone* zone,
304 uint8_t* nm, size_t len, int labs)
306 struct val_neg_data lookfor;
307 struct val_neg_data* result;
308 lookfor.node.key = &lookfor;
313 result = (struct val_neg_data*)
314 rbtree_search(&zone->tree, lookfor.node.key);
319 * Calculate space needed for the data and all its parents
320 * @param rep: NSEC entries.
323 static size_t calc_data_need(struct reply_info* rep)
326 size_t i, len, res = 0;
328 for(i=rep->an_numrrsets; i<rep->an_numrrsets+rep->ns_numrrsets; i++) {
329 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC) {
330 d = rep->rrsets[i]->rk.dname;
331 len = rep->rrsets[i]->rk.dname_len;
332 res = sizeof(struct val_neg_data) + len;
333 while(!dname_is_root(d)) {
334 log_assert(len > 1); /* not root label */
335 dname_remove_label(&d, &len);
336 res += sizeof(struct val_neg_data) + len;
344 * Calculate space needed for zone and all its parents
345 * @param d: name of zone
346 * @param len: length of name
349 static size_t calc_zone_need(uint8_t* d, size_t len)
351 size_t res = sizeof(struct val_neg_zone) + len;
352 while(!dname_is_root(d)) {
353 log_assert(len > 1); /* not root label */
354 dname_remove_label(&d, &len);
355 res += sizeof(struct val_neg_zone) + len;
361 * Find closest existing parent zone of the given name.
362 * @param neg: negative cache.
363 * @param nm: name to look for
364 * @param nm_len: length of nm
365 * @param labs: labelcount of nm.
366 * @param qclass: class.
367 * @return the zone or NULL if none found.
369 static struct val_neg_zone* neg_closest_zone_parent(struct val_neg_cache* neg,
370 uint8_t* nm, size_t nm_len, int labs, uint16_t qclass)
372 struct val_neg_zone key;
373 struct val_neg_zone* result;
374 rbnode_t* res = NULL;
380 if(rbtree_find_less_equal(&neg->tree, &key, &res)) {
382 result = (struct val_neg_zone*)res;
384 /* smaller element (or no element) */
386 result = (struct val_neg_zone*)res;
387 if(!result || result->dclass != qclass)
389 /* count number of labels matched */
390 (void)dname_lab_cmp(result->name, result->labs, key.name,
392 while(result) { /* go up until qname is subdomain of stub */
393 if(result->labs <= m)
395 result = result->parent;
402 * Find closest existing parent data for the given name.
403 * @param zone: to look in.
404 * @param nm: name to look for
405 * @param nm_len: length of nm
406 * @param labs: labelcount of nm.
407 * @return the data or NULL if none found.
409 static struct val_neg_data* neg_closest_data_parent(
410 struct val_neg_zone* zone, uint8_t* nm, size_t nm_len, int labs)
412 struct val_neg_data key;
413 struct val_neg_data* result;
414 rbnode_t* res = NULL;
419 if(rbtree_find_less_equal(&zone->tree, &key, &res)) {
421 result = (struct val_neg_data*)res;
423 /* smaller element (or no element) */
425 result = (struct val_neg_data*)res;
428 /* count number of labels matched */
429 (void)dname_lab_cmp(result->name, result->labs, key.name,
431 while(result) { /* go up until qname is subdomain of stub */
432 if(result->labs <= m)
434 result = result->parent;
441 * Create a single zone node
442 * @param nm: name for zone (copied)
443 * @param nm_len: length of name
444 * @param labs: labels in name.
445 * @param dclass: class of zone, host order.
446 * @return new zone or NULL on failure
448 static struct val_neg_zone* neg_setup_zone_node(
449 uint8_t* nm, size_t nm_len, int labs, uint16_t dclass)
451 struct val_neg_zone* zone =
452 (struct val_neg_zone*)calloc(1, sizeof(*zone));
456 zone->node.key = zone;
457 zone->name = memdup(nm, nm_len);
464 zone->dclass = dclass;
466 rbtree_init(&zone->tree, &val_neg_data_compare);
471 * Create a linked list of parent zones, starting at longname ending on
472 * the parent (can be NULL, creates to the root).
473 * @param nm: name for lowest in chain
474 * @param nm_len: length of name
475 * @param labs: labels in name.
476 * @param dclass: class of zone.
477 * @param parent: NULL for to root, else so it fits under here.
478 * @return zone; a chain of zones and their parents up to the parent.
479 * or NULL on malloc failure
481 static struct val_neg_zone* neg_zone_chain(
482 uint8_t* nm, size_t nm_len, int labs, uint16_t dclass,
483 struct val_neg_zone* parent)
486 int tolabs = parent?parent->labs:0;
487 struct val_neg_zone* zone, *prev = NULL, *first = NULL;
489 /* create the new subtree, i is labelcount of current creation */
490 /* this creates a 'first' to z->parent=NULL list of zones */
491 for(i=labs; i!=tolabs; i--) {
492 /* create new item */
493 zone = neg_setup_zone_node(nm, nm_len, i, dclass);
495 /* need to delete other allocations in this routine!*/
496 struct val_neg_zone* p=first, *np;
510 /* prepare for next name */
512 dname_remove_label(&nm, &nm_len);
517 void val_neg_zone_take_inuse(struct val_neg_zone* zone)
520 struct val_neg_zone* p;
522 /* increase usage count of all parents */
523 for(p=zone; p; p = p->parent) {
529 struct val_neg_zone* neg_create_zone(struct val_neg_cache* neg,
530 uint8_t* nm, size_t nm_len, uint16_t dclass)
532 struct val_neg_zone* zone;
533 struct val_neg_zone* parent;
534 struct val_neg_zone* p, *np;
535 int labs = dname_count_labels(nm);
537 /* find closest enclosing parent zone that (still) exists */
538 parent = neg_closest_zone_parent(neg, nm, nm_len, labs, dclass);
539 if(parent && query_dname_compare(parent->name, nm) == 0)
540 return parent; /* already exists, weird */
541 /* if parent exists, it is in use */
542 log_assert(!parent || parent->count > 0);
543 zone = neg_zone_chain(nm, nm_len, labs, dclass, parent);
548 /* insert the list of zones into the tree */
553 neg->use += sizeof(struct val_neg_zone) + p->len;
555 (void)rbtree_insert(&neg->tree, &p->node);
556 /* last one needs proper parent pointer */
564 /** find zone name of message, returns the SOA record */
565 static struct ub_packed_rrset_key* reply_find_soa(struct reply_info* rep)
568 for(i=rep->an_numrrsets; i< rep->an_numrrsets+rep->ns_numrrsets; i++){
569 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_SOA)
570 return rep->rrsets[i];
575 /** see if the reply has NSEC records worthy of caching */
576 static int reply_has_nsec(struct reply_info* rep)
579 struct packed_rrset_data* d;
580 if(rep->security != sec_status_secure)
582 for(i=rep->an_numrrsets; i< rep->an_numrrsets+rep->ns_numrrsets; i++){
583 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC) {
584 d = (struct packed_rrset_data*)rep->rrsets[i]->
586 if(d->security == sec_status_secure)
595 * Create single node of data element.
596 * @param nm: name (copied)
597 * @param nm_len: length of name
598 * @param labs: labels in name.
599 * @return element with name nm, or NULL malloc failure.
601 static struct val_neg_data* neg_setup_data_node(
602 uint8_t* nm, size_t nm_len, int labs)
604 struct val_neg_data* el;
605 el = (struct val_neg_data*)calloc(1, sizeof(*el));
610 el->name = memdup(nm, nm_len);
621 * Create chain of data element and parents
623 * @param nm_len: length of name
624 * @param labs: labels in name.
625 * @param parent: up to where to make, if NULL up to root label.
626 * @return lowest element with name nm, or NULL malloc failure.
628 static struct val_neg_data* neg_data_chain(
629 uint8_t* nm, size_t nm_len, int labs, struct val_neg_data* parent)
632 int tolabs = parent?parent->labs:0;
633 struct val_neg_data* el, *first = NULL, *prev = NULL;
635 /* create the new subtree, i is labelcount of current creation */
636 /* this creates a 'first' to z->parent=NULL list of zones */
637 for(i=labs; i!=tolabs; i--) {
638 /* create new item */
639 el = neg_setup_data_node(nm, nm_len, i);
641 /* need to delete other allocations in this routine!*/
642 struct val_neg_data* p = first, *np;
657 /* prepare for next name */
659 dname_remove_label(&nm, &nm_len);
665 * Remove NSEC records between start and end points.
666 * By walking the tree, the tree is sorted canonically.
667 * @param neg: negative cache.
668 * @param zone: the zone
669 * @param el: element to start walking at.
670 * @param nsec: the nsec record with the end point
672 static void wipeout(struct val_neg_cache* neg, struct val_neg_zone* zone,
673 struct val_neg_data* el, struct ub_packed_rrset_key* nsec)
675 struct packed_rrset_data* d = (struct packed_rrset_data*)nsec->
680 rbnode_t* walk, *next;
681 struct val_neg_data* cur;
684 if(!d || d->count == 0 || d->rr_len[0] < 2+1)
686 if(ntohs(nsec->rk.type) == LDNS_RR_TYPE_NSEC) {
687 end = d->rr_data[0]+2;
688 end_len = dname_valid(end, d->rr_len[0]-2);
689 end_labs = dname_count_labels(end);
692 if(!nsec3_get_nextowner_b32(nsec, 0, buf, sizeof(buf)))
695 end_labs = dname_count_size_labels(end, &end_len);
698 /* sanity check, both owner and end must be below the zone apex */
699 if(!dname_subdomain_c(el->name, zone->name) ||
700 !dname_subdomain_c(end, zone->name))
703 /* detect end of zone NSEC ; wipe until the end of zone */
704 if(query_dname_compare(end, zone->name) == 0) {
708 walk = rbtree_next(&el->node);
709 while(walk && walk != RBTREE_NULL) {
710 cur = (struct val_neg_data*)walk;
711 /* sanity check: must be larger than start */
712 if(dname_canon_lab_cmp(cur->name, cur->labs,
713 el->name, el->labs, &m) <= 0) {
714 /* r == 0 skip original record. */
715 /* r < 0 too small! */
716 walk = rbtree_next(walk);
719 /* stop at endpoint, also data at empty nonterminals must be
720 * removed (no NSECs there) so everything between
722 if(end && dname_canon_lab_cmp(cur->name, cur->labs,
723 end, end_labs, &m) >= 0) {
726 /* this element has to be deleted, but we cannot do it
727 * now, because we are walking the tree still ... */
728 /* get the next element: */
729 next = rbtree_next(walk);
730 /* now delete the original element, this may trigger
731 * rbtree rebalances, but really, the next element is
733 * But it may trigger delete of other data and the
734 * entire zone. However, if that happens, this is done
735 * by deleting the *parents* of the element for deletion,
736 * and maybe also the entire zone if it is empty.
737 * But parents are smaller in canonical compare, thus,
738 * if a larger element exists, then it is not a parent,
739 * it cannot get deleted, the zone cannot get empty.
740 * If the next==NULL, then zone can be empty. */
742 neg_delete_data(neg, cur);
747 void neg_insert_data(struct val_neg_cache* neg,
748 struct val_neg_zone* zone, struct ub_packed_rrset_key* nsec)
750 struct packed_rrset_data* d;
751 struct val_neg_data* parent;
752 struct val_neg_data* el;
753 uint8_t* nm = nsec->rk.dname;
754 size_t nm_len = nsec->rk.dname_len;
755 int labs = dname_count_labels(nsec->rk.dname);
757 d = (struct packed_rrset_data*)nsec->entry.data;
758 if( !(d->security == sec_status_secure ||
759 (d->security == sec_status_unchecked && d->rrsig_count > 0)))
761 log_nametypeclass(VERB_ALGO, "negcache rr",
762 nsec->rk.dname, ntohs(nsec->rk.type),
763 ntohs(nsec->rk.rrset_class));
765 /* find closest enclosing parent data that (still) exists */
766 parent = neg_closest_data_parent(zone, nm, nm_len, labs);
767 if(parent && query_dname_compare(parent->name, nm) == 0) {
768 /* perfect match already exists */
769 log_assert(parent->count > 0);
772 struct val_neg_data* p, *np;
774 /* create subtree for perfect match */
775 /* if parent exists, it is in use */
776 log_assert(!parent || parent->count > 0);
778 el = neg_data_chain(nm, nm_len, labs, parent);
780 log_err("out of memory inserting NSEC negative cache");
783 el->in_use = 0; /* set on below */
785 /* insert the list of zones into the tree */
790 neg->use += sizeof(struct val_neg_data) + p->len;
793 (void)rbtree_insert(&zone->tree, &p->node);
794 /* last one needs proper parent pointer */
802 struct val_neg_data* p;
805 /* increase usage count of all parents */
806 for(p=el; p; p = p->parent) {
810 neg_lru_front(neg, el);
812 /* in use, bring to front, lru */
813 neg_lru_touch(neg, el);
816 /* if nsec3 store last used parameters */
817 if(ntohs(nsec->rk.type) == LDNS_RR_TYPE_NSEC3) {
821 if(nsec3_get_params(nsec, 0, &h, &it, &s, &slen) &&
822 it <= neg->nsec3_max_iter &&
823 (h != zone->nsec3_hash || it != zone->nsec3_iter ||
824 slen != zone->nsec3_saltlen ||
825 memcmp(zone->nsec3_salt, s, slen) != 0)) {
828 uint8_t* sa = memdup(s, slen);
830 free(zone->nsec3_salt);
831 zone->nsec3_salt = sa;
832 zone->nsec3_saltlen = slen;
833 zone->nsec3_iter = it;
834 zone->nsec3_hash = h;
837 free(zone->nsec3_salt);
838 zone->nsec3_salt = NULL;
839 zone->nsec3_saltlen = 0;
840 zone->nsec3_iter = it;
841 zone->nsec3_hash = h;
846 /* wipe out the cache items between NSEC start and end */
847 wipeout(neg, zone, el, nsec);
850 void val_neg_addreply(struct val_neg_cache* neg, struct reply_info* rep)
853 struct ub_packed_rrset_key* soa;
854 struct val_neg_zone* zone;
855 /* see if secure nsecs inside */
856 if(!reply_has_nsec(rep))
858 /* find the zone name in message */
859 soa = reply_find_soa(rep);
863 log_nametypeclass(VERB_ALGO, "negcache insert for zone",
864 soa->rk.dname, LDNS_RR_TYPE_SOA, ntohs(soa->rk.rrset_class));
866 /* ask for enough space to store all of it */
867 need = calc_data_need(rep) +
868 calc_zone_need(soa->rk.dname, soa->rk.dname_len);
869 lock_basic_lock(&neg->lock);
870 neg_make_space(neg, need);
872 /* find or create the zone entry */
873 zone = neg_find_zone(neg, soa->rk.dname, soa->rk.dname_len,
874 ntohs(soa->rk.rrset_class));
876 if(!(zone = neg_create_zone(neg, soa->rk.dname,
877 soa->rk.dname_len, ntohs(soa->rk.rrset_class)))) {
878 lock_basic_unlock(&neg->lock);
879 log_err("out of memory adding negative zone");
883 val_neg_zone_take_inuse(zone);
885 /* insert the NSECs */
886 for(i=rep->an_numrrsets; i< rep->an_numrrsets+rep->ns_numrrsets; i++){
887 if(ntohs(rep->rrsets[i]->rk.type) != LDNS_RR_TYPE_NSEC)
889 if(!dname_subdomain_c(rep->rrsets[i]->rk.dname,
890 zone->name)) continue;
891 /* insert NSEC into this zone's tree */
892 neg_insert_data(neg, zone, rep->rrsets[i]);
894 if(zone->tree.count == 0) {
895 /* remove empty zone if inserts failed */
896 neg_delete_zone(neg, zone);
898 lock_basic_unlock(&neg->lock);
902 * Lookup closest data record. For NSEC denial.
903 * @param zone: zone to look in
904 * @param qname: name to look for.
905 * @param len: length of name
906 * @param labs: labels in name
907 * @param data: data element, exact or smaller or NULL
908 * @return true if exact match.
910 static int neg_closest_data(struct val_neg_zone* zone,
911 uint8_t* qname, size_t len, int labs, struct val_neg_data** data)
913 struct val_neg_data key;
919 if(rbtree_find_less_equal(&zone->tree, &key, &r)) {
921 *data = (struct val_neg_data*)r;
925 *data = (struct val_neg_data*)r;
930 int val_neg_dlvlookup(struct val_neg_cache* neg, uint8_t* qname, size_t len,
931 uint16_t qclass, struct rrset_cache* rrset_cache, time_t now)
933 /* lookup closest zone */
934 struct val_neg_zone* zone;
935 struct val_neg_data* data;
937 struct ub_packed_rrset_key* nsec;
938 struct packed_rrset_data* d;
941 struct query_info qinfo;
944 log_nametypeclass(VERB_ALGO, "negcache dlvlookup", qname,
945 LDNS_RR_TYPE_DLV, qclass);
947 labs = dname_count_labels(qname);
948 lock_basic_lock(&neg->lock);
949 zone = neg_closest_zone_parent(neg, qname, len, labs, qclass);
950 while(zone && !zone->in_use)
953 lock_basic_unlock(&neg->lock);
956 log_nametypeclass(VERB_ALGO, "negcache zone", zone->name, 0,
959 /* DLV is defined to use NSEC only */
960 if(zone->nsec3_hash) {
961 lock_basic_unlock(&neg->lock);
965 /* lookup closest data record */
966 (void)neg_closest_data(zone, qname, len, labs, &data);
967 while(data && !data->in_use)
970 lock_basic_unlock(&neg->lock);
973 log_nametypeclass(VERB_ALGO, "negcache rr", data->name,
974 LDNS_RR_TYPE_NSEC, zone->dclass);
976 /* lookup rrset in rrset cache */
978 if(query_dname_compare(data->name, zone->name) == 0)
979 flags = PACKED_RRSET_NSEC_AT_APEX;
980 nsec = rrset_cache_lookup(rrset_cache, data->name, data->len,
981 LDNS_RR_TYPE_NSEC, zone->dclass, flags, now, 0);
983 /* check if secure and TTL ok */
985 lock_basic_unlock(&neg->lock);
988 d = (struct packed_rrset_data*)nsec->entry.data;
989 if(!d || now > d->ttl) {
990 lock_rw_unlock(&nsec->entry.lock);
991 /* delete data record if expired */
992 neg_delete_data(neg, data);
993 lock_basic_unlock(&neg->lock);
996 if(d->security != sec_status_secure) {
997 lock_rw_unlock(&nsec->entry.lock);
998 neg_delete_data(neg, data);
999 lock_basic_unlock(&neg->lock);
1002 verbose(VERB_ALGO, "negcache got secure rrset");
1004 /* check NSEC security */
1005 /* check if NSEC proves no DLV type exists */
1006 /* check if NSEC proves NXDOMAIN for qname */
1007 qinfo.qname = qname;
1008 qinfo.qtype = LDNS_RR_TYPE_DLV;
1009 qinfo.qclass = qclass;
1010 if(!nsec_proves_nodata(nsec, &qinfo, &wc) &&
1011 !val_nsec_proves_name_error(nsec, qname)) {
1012 /* the NSEC is not a denial for the DLV */
1013 lock_rw_unlock(&nsec->entry.lock);
1014 lock_basic_unlock(&neg->lock);
1015 verbose(VERB_ALGO, "negcache not proven");
1018 /* so the NSEC was a NODATA proof, or NXDOMAIN proof. */
1020 /* no need to check for wildcard NSEC; no wildcards in DLV repos */
1021 /* no need to lookup SOA record for client; no response message */
1023 lock_rw_unlock(&nsec->entry.lock);
1024 /* if OK touch the LRU for neg_data element */
1025 neg_lru_touch(neg, data);
1026 lock_basic_unlock(&neg->lock);
1027 verbose(VERB_ALGO, "negcache DLV denial proven");
1031 /** see if the reply has signed NSEC records and return the signer */
1032 static uint8_t* reply_nsec_signer(struct reply_info* rep, size_t* signer_len,
1036 struct packed_rrset_data* d;
1038 for(i=rep->an_numrrsets; i< rep->an_numrrsets+rep->ns_numrrsets; i++){
1039 if(ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC ||
1040 ntohs(rep->rrsets[i]->rk.type) == LDNS_RR_TYPE_NSEC3) {
1041 d = (struct packed_rrset_data*)rep->rrsets[i]->
1043 /* return first signer name of first NSEC */
1044 if(d->rrsig_count != 0) {
1045 val_find_rrset_signer(rep->rrsets[i],
1047 if(s && *signer_len) {
1048 *dclass = ntohs(rep->rrsets[i]->
1058 void val_neg_addreferral(struct val_neg_cache* neg, struct reply_info* rep,
1065 struct val_neg_zone* zone;
1066 /* no SOA in this message, find RRSIG over NSEC's signer name.
1067 * note the NSEC records are maybe not validated yet */
1068 signer = reply_nsec_signer(rep, &signer_len, &dclass);
1071 if(!dname_subdomain_c(signer, zone_name)) {
1072 /* the signer is not in the bailiwick, throw it out */
1076 log_nametypeclass(VERB_ALGO, "negcache insert referral ",
1077 signer, LDNS_RR_TYPE_NS, dclass);
1079 /* ask for enough space to store all of it */
1080 need = calc_data_need(rep) + calc_zone_need(signer, signer_len);
1081 lock_basic_lock(&neg->lock);
1082 neg_make_space(neg, need);
1084 /* find or create the zone entry */
1085 zone = neg_find_zone(neg, signer, signer_len, dclass);
1087 if(!(zone = neg_create_zone(neg, signer, signer_len,
1089 lock_basic_unlock(&neg->lock);
1090 log_err("out of memory adding negative zone");
1094 val_neg_zone_take_inuse(zone);
1096 /* insert the NSECs */
1097 for(i=rep->an_numrrsets; i< rep->an_numrrsets+rep->ns_numrrsets; i++){
1098 if(ntohs(rep->rrsets[i]->rk.type) != LDNS_RR_TYPE_NSEC &&
1099 ntohs(rep->rrsets[i]->rk.type) != LDNS_RR_TYPE_NSEC3)
1101 if(!dname_subdomain_c(rep->rrsets[i]->rk.dname,
1102 zone->name)) continue;
1103 /* insert NSEC into this zone's tree */
1104 neg_insert_data(neg, zone, rep->rrsets[i]);
1106 if(zone->tree.count == 0) {
1107 /* remove empty zone if inserts failed */
1108 neg_delete_zone(neg, zone);
1110 lock_basic_unlock(&neg->lock);
1114 * Check that an NSEC3 rrset does not have a type set.
1115 * None of the nsec3s in a hash-collision are allowed to have the type.
1116 * (since we do not know which one is the nsec3 looked at, flags, ..., we
1117 * ignore the cached item and let it bypass negative caching).
1118 * @param k: the nsec3 rrset to check.
1119 * @param t: type to check
1120 * @return true if no RRs have the type.
1122 static int nsec3_no_type(struct ub_packed_rrset_key* k, uint16_t t)
1124 int count = (int)((struct packed_rrset_data*)k->entry.data)->count;
1126 for(i=0; i<count; i++)
1127 if(nsec3_has_type(k, i, t))
1133 * See if rrset exists in rrset cache.
1134 * If it does, the bit is checked, and if not expired, it is returned
1135 * allocated in region.
1136 * @param rrset_cache: rrset cache
1137 * @param qname: to lookup rrset name
1138 * @param qname_len: length of qname.
1139 * @param qtype: type of rrset to lookup, host order
1140 * @param qclass: class of rrset to lookup, host order
1141 * @param flags: flags for rrset to lookup
1142 * @param region: where to alloc result
1143 * @param checkbit: if true, a bit in the nsec typemap is checked for absence.
1144 * @param checktype: which bit to check
1145 * @param now: to check ttl against
1146 * @return rrset or NULL
1148 static struct ub_packed_rrset_key*
1149 grab_nsec(struct rrset_cache* rrset_cache, uint8_t* qname, size_t qname_len,
1150 uint16_t qtype, uint16_t qclass, uint32_t flags,
1151 struct regional* region, int checkbit, uint16_t checktype,
1154 struct ub_packed_rrset_key* r, *k = rrset_cache_lookup(rrset_cache,
1155 qname, qname_len, qtype, qclass, flags, now, 0);
1156 struct packed_rrset_data* d;
1158 d = (struct packed_rrset_data*)k->entry.data;
1160 lock_rw_unlock(&k->entry.lock);
1163 /* only secure or unchecked records that have signatures. */
1164 if( ! ( d->security == sec_status_secure ||
1165 (d->security == sec_status_unchecked &&
1166 d->rrsig_count > 0) ) ) {
1167 lock_rw_unlock(&k->entry.lock);
1170 /* check if checktype is absent */
1172 (qtype == LDNS_RR_TYPE_NSEC && nsec_has_type(k, checktype)) ||
1173 (qtype == LDNS_RR_TYPE_NSEC3 && !nsec3_no_type(k, checktype))
1175 lock_rw_unlock(&k->entry.lock);
1178 /* looks OK! copy to region and return it */
1179 r = packed_rrset_copy_region(k, region, now);
1180 /* if it failed, we return the NULL */
1181 lock_rw_unlock(&k->entry.lock);
1185 /** find nsec3 closest encloser in neg cache */
1186 static struct val_neg_data*
1187 neg_find_nsec3_ce(struct val_neg_zone* zone, uint8_t* qname, size_t qname_len,
1188 int qlabs, sldns_buffer* buf, uint8_t* hashnc, size_t* nclen)
1190 struct val_neg_data* data;
1191 uint8_t hashce[NSEC3_SHA_LEN];
1193 size_t celen, b32len;
1198 if(!(celen=nsec3_get_hashed(buf, qname, qname_len,
1199 zone->nsec3_hash, zone->nsec3_iter, zone->nsec3_salt,
1200 zone->nsec3_saltlen, hashce, sizeof(hashce))))
1202 if(!(b32len=nsec3_hash_to_b32(hashce, celen, zone->name,
1203 zone->len, b32, sizeof(b32))))
1206 /* lookup (exact match only) */
1207 data = neg_find_data(zone, b32, b32len, zone->labs+1);
1208 if(data && data->in_use) {
1209 /* found ce match! */
1214 memmove(hashnc, hashce, celen);
1215 dname_remove_label(&qname, &qname_len);
1221 /** check nsec3 parameters on nsec3 rrset with current zone values */
1223 neg_params_ok(struct val_neg_zone* zone, struct ub_packed_rrset_key* rrset)
1228 if(!nsec3_get_params(rrset, 0, &h, &it, &s, &slen))
1230 return (h == zone->nsec3_hash && it == zone->nsec3_iter &&
1231 slen == zone->nsec3_saltlen &&
1232 memcmp(zone->nsec3_salt, s, slen) == 0);
1235 /** get next closer for nsec3 proof */
1236 static struct ub_packed_rrset_key*
1237 neg_nsec3_getnc(struct val_neg_zone* zone, uint8_t* hashnc, size_t nclen,
1238 struct rrset_cache* rrset_cache, struct regional* region,
1239 time_t now, uint8_t* b32, size_t maxb32)
1241 struct ub_packed_rrset_key* nc_rrset;
1242 struct val_neg_data* data;
1245 if(!(b32len=nsec3_hash_to_b32(hashnc, nclen, zone->name,
1246 zone->len, b32, maxb32)))
1248 (void)neg_closest_data(zone, b32, b32len, zone->labs+1, &data);
1249 if(!data && zone->tree.count != 0) {
1250 /* could be before the first entry ; return the last
1251 * entry (possibly the rollover nsec3 at end) */
1252 data = (struct val_neg_data*)rbtree_last(&zone->tree);
1254 while(data && !data->in_use)
1255 data = data->parent;
1258 /* got a data element in tree, grab it */
1259 nc_rrset = grab_nsec(rrset_cache, data->name, data->len,
1260 LDNS_RR_TYPE_NSEC3, zone->dclass, 0, region, 0, 0, now);
1263 if(!neg_params_ok(zone, nc_rrset))
1268 /** neg cache nsec3 proof procedure*/
1269 static struct dns_msg*
1270 neg_nsec3_proof_ds(struct val_neg_zone* zone, uint8_t* qname, size_t qname_len,
1271 int qlabs, sldns_buffer* buf, struct rrset_cache* rrset_cache,
1272 struct regional* region, time_t now, uint8_t* topname)
1274 struct dns_msg* msg;
1275 struct val_neg_data* data;
1276 uint8_t hashnc[NSEC3_SHA_LEN];
1278 struct ub_packed_rrset_key* ce_rrset, *nc_rrset;
1279 struct nsec3_cached_hash c;
1280 uint8_t nc_b32[257];
1282 /* for NSEC3 ; determine the closest encloser for which we
1283 * can find an exact match. Remember the hashed lower name,
1284 * since that is the one we need a closest match for.
1285 * If we find a match straight away, then it becomes NODATA.
1286 * Otherwise, NXDOMAIN or if OPTOUT, an insecure delegation.
1287 * Also check that parameters are the same on closest encloser
1288 * and on closest match.
1290 if(!zone->nsec3_hash)
1291 return NULL; /* not nsec3 zone */
1293 if(!(data=neg_find_nsec3_ce(zone, qname, qname_len, qlabs, buf,
1298 /* grab the ce rrset */
1299 ce_rrset = grab_nsec(rrset_cache, data->name, data->len,
1300 LDNS_RR_TYPE_NSEC3, zone->dclass, 0, region, 1,
1301 LDNS_RR_TYPE_DS, now);
1304 if(!neg_params_ok(zone, ce_rrset))
1308 /* exact match, just check the type bits */
1309 /* need: -SOA, -DS, +NS */
1310 if(nsec3_has_type(ce_rrset, 0, LDNS_RR_TYPE_SOA) ||
1311 nsec3_has_type(ce_rrset, 0, LDNS_RR_TYPE_DS) ||
1312 !nsec3_has_type(ce_rrset, 0, LDNS_RR_TYPE_NS))
1314 if(!(msg = dns_msg_create(qname, qname_len,
1315 LDNS_RR_TYPE_DS, zone->dclass, region, 1)))
1317 /* TTL reduced in grab_nsec */
1318 if(!dns_msg_authadd(msg, region, ce_rrset, 0))
1323 /* optout is not allowed without knowing the trust-anchor in use,
1324 * otherwise the optout could spoof away that anchor */
1328 /* if there is no exact match, it must be in an optout span
1329 * (an existing DS implies an NSEC3 must exist) */
1330 nc_rrset = neg_nsec3_getnc(zone, hashnc, nclen, rrset_cache,
1331 region, now, nc_b32, sizeof(nc_b32));
1334 if(!neg_params_ok(zone, nc_rrset))
1336 if(!nsec3_has_optout(nc_rrset, 0))
1341 c.b32_len = (size_t)nc_b32[0];
1342 if(nsec3_covers(zone->name, &c, nc_rrset, 0, buf)) {
1343 /* nc_rrset covers the next closer name.
1344 * ce_rrset equals a closer encloser.
1345 * nc_rrset is optout.
1346 * No need to check wildcard for type DS */
1347 /* capacity=3: ce + nc + soa(if needed) */
1348 if(!(msg = dns_msg_create(qname, qname_len,
1349 LDNS_RR_TYPE_DS, zone->dclass, region, 3)))
1351 /* now=0 because TTL was reduced in grab_nsec */
1352 if(!dns_msg_authadd(msg, region, ce_rrset, 0))
1354 if(!dns_msg_authadd(msg, region, nc_rrset, 0))
1362 * Add SOA record for external responses.
1363 * @param rrset_cache: to look into.
1364 * @param now: current time.
1365 * @param region: where to perform the allocation
1366 * @param msg: current msg with NSEC.
1367 * @param zone: val_neg_zone if we have one.
1368 * @return false on lookup or alloc failure.
1370 static int add_soa(struct rrset_cache* rrset_cache, time_t now,
1371 struct regional* region, struct dns_msg* msg, struct val_neg_zone* zone)
1373 struct ub_packed_rrset_key* soa;
1380 dclass = zone->dclass;
1382 /* Assumes the signer is the zone SOA to add */
1383 nm = reply_nsec_signer(msg->rep, &nmlen, &dclass);
1387 soa = rrset_cache_lookup(rrset_cache, nm, nmlen, LDNS_RR_TYPE_SOA,
1388 dclass, PACKED_RRSET_SOA_NEG, now, 0);
1391 if(!dns_msg_authadd(msg, region, soa, now)) {
1392 lock_rw_unlock(&soa->entry.lock);
1395 lock_rw_unlock(&soa->entry.lock);
1400 val_neg_getmsg(struct val_neg_cache* neg, struct query_info* qinfo,
1401 struct regional* region, struct rrset_cache* rrset_cache,
1402 sldns_buffer* buf, time_t now, int addsoa, uint8_t* topname)
1404 struct dns_msg* msg;
1405 struct ub_packed_rrset_key* rrset;
1409 struct val_neg_zone* zone;
1411 /* only for DS queries */
1412 if(qinfo->qtype != LDNS_RR_TYPE_DS)
1414 log_assert(!topname || dname_subdomain_c(qinfo->qname, topname));
1416 /* see if info from neg cache is available
1417 * For NSECs, because there is no optout; a DS next to a delegation
1418 * always has exactly an NSEC for it itself; check its DS bit.
1419 * flags=0 (not the zone apex).
1421 rrset = grab_nsec(rrset_cache, qinfo->qname, qinfo->qname_len,
1422 LDNS_RR_TYPE_NSEC, qinfo->qclass, 0, region, 1,
1425 /* return msg with that rrset */
1426 if(!(msg = dns_msg_create(qinfo->qname, qinfo->qname_len,
1427 qinfo->qtype, qinfo->qclass, region, 2)))
1429 /* TTL already subtracted in grab_nsec */
1430 if(!dns_msg_authadd(msg, region, rrset, 0))
1432 if(addsoa && !add_soa(rrset_cache, now, region, msg, NULL))
1437 /* check NSEC3 neg cache for type DS */
1438 /* need to look one zone higher for DS type */
1439 zname = qinfo->qname;
1440 zname_len = qinfo->qname_len;
1441 dname_remove_label(&zname, &zname_len);
1442 zname_labs = dname_count_labels(zname);
1444 /* lookup closest zone */
1445 lock_basic_lock(&neg->lock);
1446 zone = neg_closest_zone_parent(neg, zname, zname_len, zname_labs,
1448 while(zone && !zone->in_use)
1449 zone = zone->parent;
1450 /* check that the zone is not too high up so that we do not pick data
1451 * out of a zone that is above the last-seen key (or trust-anchor). */
1452 if(zone && topname) {
1453 if(!dname_subdomain_c(zone->name, topname))
1457 lock_basic_unlock(&neg->lock);
1461 msg = neg_nsec3_proof_ds(zone, qinfo->qname, qinfo->qname_len,
1462 zname_labs+1, buf, rrset_cache, region, now, topname);
1463 if(msg && addsoa && !add_soa(rrset_cache, now, region, msg, zone)) {
1464 lock_basic_unlock(&neg->lock);
1467 lock_basic_unlock(&neg->lock);