val_utils.h File Reference

This file contains helper functions for the validator module. More...

#include "util/data/packed_rrset.h"
#include "sldns/pkthdr.h"
#include "sldns/rrdef.h"

Enumerations
enum	val_classification {   VAL_CLASS_UNTYPED = 0 , VAL_CLASS_UNKNOWN , VAL_CLASS_POSITIVE , VAL_CLASS_CNAME ,   VAL_CLASS_NODATA , VAL_CLASS_NAMEERROR , VAL_CLASS_CNAMENOANSWER , VAL_CLASS_REFERRAL ,   VAL_CLASS_ANY }
	Response classifications for the validator. More...

Functions
enum val_classification	val_classify_response (uint16_t query_flags, struct query_info *origqinf, struct query_info *qinf, struct reply_info *rep, size_t skip)
	Given a response, classify ANSWER responses into a subtype. More...
void	val_find_signer (enum val_classification subtype, struct query_info *qinf, struct reply_info *rep, size_t cname_skip, uint8_t **signer_name, size_t *signer_len)
	Given a response, determine the name of the "signer". More...
enum sec_status	val_verify_rrset_entry (struct module_env *env, struct val_env *ve, struct ub_packed_rrset_key *rrset, struct key_entry_key *kkey, char **reason, sldns_ede_code *reason_bogus, sldns_pkt_section section, struct module_qstate *qstate, int *verified)
	Verify RRset with keys from a keyset. More...
enum sec_status	val_verify_DNSKEY_with_DS (struct module_env *env, struct val_env *ve, struct ub_packed_rrset_key *dnskey_rrset, struct ub_packed_rrset_key *ds_rrset, uint8_t *sigalg, char **reason, sldns_ede_code *reason_bogus, struct module_qstate *qstate)
	Verify DNSKEYs with DS rrset. More...
enum sec_status	val_verify_DNSKEY_with_TA (struct module_env *env, struct val_env *ve, struct ub_packed_rrset_key *dnskey_rrset, struct ub_packed_rrset_key *ta_ds, struct ub_packed_rrset_key *ta_dnskey, uint8_t *sigalg, char **reason, sldns_ede_code *reason_bogus, struct module_qstate *qstate)
	Verify DNSKEYs with DS and DNSKEY rrset. More...
struct key_entry_key *	val_verify_new_DNSKEYs (struct regional *region, struct module_env *env, struct val_env *ve, struct ub_packed_rrset_key *dnskey_rrset, struct ub_packed_rrset_key *ds_rrset, int downprot, char **reason, sldns_ede_code *reason_bogus, struct module_qstate *qstate)
	Verify new DNSKEYs with DS rrset. More...
struct key_entry_key *	val_verify_new_DNSKEYs_with_ta (struct regional *region, struct module_env *env, struct val_env *ve, struct ub_packed_rrset_key *dnskey_rrset, struct ub_packed_rrset_key *ta_ds_rrset, struct ub_packed_rrset_key *ta_dnskey_rrset, int downprot, char **reason, sldns_ede_code *reason_bogus, struct module_qstate *qstate)
	Verify rrset with trust anchor: DS and DNSKEY rrset. More...
int	val_dsset_isusable (struct ub_packed_rrset_key *ds_rrset)
	Determine if DS rrset is usable for validator or not. More...
int	val_rrset_wildcard (struct ub_packed_rrset_key *rrset, uint8_t **wc, size_t *wc_len)
	Determine by looking at a signed RRset whether or not the RRset name was the result of a wildcard expansion. More...
int	val_chase_cname (struct query_info *qchase, struct reply_info *rep, size_t *cname_skip)
	Chase the cname to the next query name. More...
void	val_fill_reply (struct reply_info *chase, struct reply_info *orig, size_t cname_skip, uint8_t *name, size_t len, uint8_t *signer)
	Fill up the chased reply with the content from the original reply; as pointers to those rrsets. More...
void	val_reply_remove_auth (struct reply_info *rep, size_t index)
	Remove rrset with index from reply, from the authority section. More...
void	val_check_nonsecure (struct module_env *env, struct reply_info *rep)
	Remove all unsigned or non-secure status rrsets from NS and AR sections. More...
void	val_mark_indeterminate (struct reply_info *rep, struct val_anchors *anchors, struct rrset_cache *r, struct module_env *env)
	Mark all unchecked rrset entries not below a trust anchor as indeterminate. More...
void	val_mark_insecure (struct reply_info *rep, uint8_t *kname, struct rrset_cache *r, struct module_env *env)
	Mark all unchecked rrset entries below a NULL key entry as insecure. More...
size_t	val_next_unchecked (struct reply_info *rep, size_t skip)
	Find next unchecked rrset position, return it for skip. More...
void	val_find_rrset_signer (struct ub_packed_rrset_key *rrset, uint8_t **sname, size_t *slen)
	Find the signer name for an RRset. More...
const char *	val_classification_to_string (enum val_classification subtype)
	Get string to denote the classification result. More...
void	val_blacklist (struct sock_list **blacklist, struct regional *region, struct sock_list *origin, int cross)
	Add existing list to blacklist. More...
int	val_has_signed_nsecs (struct reply_info *rep, char **reason)
	check if has dnssec info, and if it has signed nsecs. More...
int	val_favorite_ds_algo (struct ub_packed_rrset_key *ds_rrset)
	Return algo number for favorite (best) algorithm that we support in DS. More...
struct dns_msg *	val_find_DS (struct module_env *env, uint8_t *nm, size_t nmlen, uint16_t c, struct regional *region, uint8_t *topname)
	Find DS denial message in cache. More...

Detailed Description

This file contains helper functions for the validator module.

Enumeration Type Documentation

val_classification

enum val_classification

Response classifications for the validator.

The different types of proofs.

Enumerator
VAL_CLASS_UNTYPED	Not subtyped yet.
VAL_CLASS_UNKNOWN	Not a recognized subtype.
VAL_CLASS_POSITIVE	A positive, direct, response.
VAL_CLASS_CNAME	A positive response, with a CNAME/DNAME chain.
VAL_CLASS_NODATA	A NOERROR/NODATA response.
VAL_CLASS_NAMEERROR	A NXDOMAIN response.
VAL_CLASS_CNAMENOANSWER	A CNAME/DNAME chain, and the offset is at the end of it, but there is no answer here, it can be NAMEERROR or NODATA.
VAL_CLASS_REFERRAL	A referral, from cache with a nonRD query.
VAL_CLASS_ANY	A response to a qtype=ANY query.

Function Documentation

val_classify_response()

enum val_classification val_classify_response	(	uint16_t	query_flags,
		struct query_info *	origqinf,
		struct query_info *	qinf,
		struct reply_info *	rep,
		size_t	skip
	)

Given a response, classify ANSWER responses into a subtype.

Parameters

query_flags	query flags for the original query.
origqinf	query info. The original query name.
qinf	query info. The chased query name.
rep	response. The original response.
skip	offset into the original response answer section.

Returns

A subtype, all values possible except UNTYPED . Once CNAME type is returned you can increase skip. Then, another CNAME type, CNAME_NOANSWER or POSITIVE are possible.

Referenced by processFinished(), and processInit().

val_find_signer()

void val_find_signer	(	enum val_classification	subtype,
		struct query_info *	qinf,
		struct reply_info *	rep,
		size_t	cname_skip,
		uint8_t **	signer_name,
		size_t *	signer_len
	)

Given a response, determine the name of the "signer".

This is primarily to determine if the response is, in fact, signed at all, and, if so, what is the name of the most pertinent keyset.

Parameters

subtype	the type from classify.
qinf	query, the chased query name.
rep	response to that, original response.
cname_skip	how many answer rrsets have been skipped due to CNAME chains being chased around.
signer_name	signer name, if the response is signed (even partially), or null if the response isn't signed.
signer_len	length of signer_name of 0 if signer_name is NULL.

References reply_info::an_numrrsets, packed_rrset_key::dname, LDNS_RR_TYPE_DNAME, reply_info::ns_numrrsets, query_info::qname, query_dname_compare(), ub_packed_rrset_key::rk, reply_info::rrsets, packed_rrset_key::type, VAL_CLASS_CNAME, VAL_CLASS_NAMEERROR, VAL_CLASS_NODATA, VAL_CLASS_POSITIVE, and val_find_rrset_signer().

val_verify_rrset_entry()

enum sec_status val_verify_rrset_entry	(	struct module_env *	env,
		struct val_env *	ve,
		struct ub_packed_rrset_key *	rrset,
		struct key_entry_key *	kkey,
		char **	reason,
		sldns_ede_code *	reason_bogus,
		sldns_pkt_section	section,
		struct module_qstate *	qstate,
		int *	verified
	)

Verify RRset with keys from a keyset.

Parameters

env	module environment (scratch buffer)
ve	validator environment (verification settings)
rrset	what to verify
kkey	key_entry to verify with.
reason	reason of failure. Fixed string or alloced in scratch.
reason_bogus	EDE (RFC8914) code paired with the reason of failure.
section	section of packet where this rrset comes from.
qstate	qstate with region.
verified	if not NULL, the number of RRSIG validations is returned.

Returns

security status of verification.

Referenced by nsec_verify_rrset().

val_verify_DNSKEY_with_DS()

enum sec_status val_verify_DNSKEY_with_DS	(	struct module_env *	env,
		struct val_env *	ve,
		struct ub_packed_rrset_key *	dnskey_rrset,
		struct ub_packed_rrset_key *	ds_rrset,
		uint8_t *	sigalg,
		char **	reason,
		sldns_ede_code *	reason_bogus,
		struct module_qstate *	qstate
	)

Verify DNSKEYs with DS rrset.

Like val_verify_new_DNSKEYs but returns a sec_status instead of a key_entry.

Parameters

env	module environment (scratch buffer)
ve	validator environment (verification settings)
dnskey_rrset	DNSKEY rrset to verify
ds_rrset	DS rrset to verify with.
sigalg	if nonNULL provide downgrade protection otherwise one algorithm is enough. The list of signalled algorithms is returned, must have enough space for ALGO_NEEDS_MAX+1.
reason	reason of failure. Fixed string or alloced in scratch.
reason_bogus	EDE (RFC8914) code paired with the reason of failure.
qstate	qstate with region.

Returns

: sec_status_secure if a DS matches. sec_status_insecure if end of trust (i.e., unknown algorithms). sec_status_bogus if it fails.

Referenced by val_verify_DNSKEY_with_TA().

val_verify_DNSKEY_with_TA()

enum sec_status val_verify_DNSKEY_with_TA	(	struct module_env *	env,
		struct val_env *	ve,
		struct ub_packed_rrset_key *	dnskey_rrset,
		struct ub_packed_rrset_key *	ta_ds,
		struct ub_packed_rrset_key *	ta_dnskey,
		uint8_t *	sigalg,
		char **	reason,
		sldns_ede_code *	reason_bogus,
		struct module_qstate *	qstate
	)

Verify DNSKEYs with DS and DNSKEY rrset.

Like val_verify_DNSKEY_with_DS but for a trust anchor.

Parameters

env	module environment (scratch buffer)
ve	validator environment (verification settings)
dnskey_rrset	DNSKEY rrset to verify
ta_ds	DS rrset to verify with.
ta_dnskey	DNSKEY rrset to verify with.
sigalg	if nonNULL provide downgrade protection otherwise one algorithm is enough. The list of signalled algorithms is returned, must have enough space for ALGO_NEEDS_MAX+1.
reason	reason of failure. Fixed string or alloced in scratch.
reason_bogus	EDE (RFC8914) code paired with the reason of failure.
qstate	qstate with region.

Returns

: sec_status_secure if a DS matches. sec_status_insecure if end of trust (i.e., unknown algorithms). sec_status_bogus if it fails.

References ALGO_NEEDS_MAX, packed_rrset_key::dname, packed_rrset_key::dname_len, key_entry_create_rrset(), ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, sec_status_secure, and val_verify_DNSKEY_with_DS().

Referenced by val_verify_new_DNSKEYs_with_ta(), and verify_dnskey().

val_verify_new_DNSKEYs()

struct key_entry_key* val_verify_new_DNSKEYs	(	struct regional *	region,
		struct module_env *	env,
		struct val_env *	ve,
		struct ub_packed_rrset_key *	dnskey_rrset,
		struct ub_packed_rrset_key *	ds_rrset,
		int	downprot,
		char **	reason,
		sldns_ede_code *	reason_bogus,
		struct module_qstate *	qstate
	)

Verify new DNSKEYs with DS rrset.

The DS contains hash values that should match the DNSKEY keys. match the DS to a DNSKEY and verify the DNSKEY rrset with that key.

Parameters

region	where to allocate key entry result.
env	module environment (scratch buffer)
ve	validator environment (verification settings)
dnskey_rrset	DNSKEY rrset to verify
ds_rrset	DS rrset to verify with.
downprot	if true provide downgrade protection otherwise one algorithm is enough.
reason	reason of failure. Fixed string or alloced in scratch.
reason_bogus	EDE (RFC8914) code paired with the reason of failure.
qstate	qstate with region.

Returns

a KeyEntry. This will either contain the now trusted dnskey_rrset, a "null" key entry indicating that this DS rrset/DNSKEY pair indicate an secure end to the island of trust (i.e., unknown algorithms), or a "bad" KeyEntry if the dnskey rrset fails to verify. Note that the "null" response should generally only occur in a private algorithm scenario: normally this sort of thing is checked before fetching the matching DNSKEY rrset. if downprot is set, a key entry with an algo list is made.

val_verify_new_DNSKEYs_with_ta()

struct key_entry_key* val_verify_new_DNSKEYs_with_ta	(	struct regional *	region,
		struct module_env *	env,
		struct val_env *	ve,
		struct ub_packed_rrset_key *	dnskey_rrset,
		struct ub_packed_rrset_key *	ta_ds_rrset,
		struct ub_packed_rrset_key *	ta_dnskey_rrset,
		int	downprot,
		char **	reason,
		sldns_ede_code *	reason_bogus,
		struct module_qstate *	qstate
	)

Verify rrset with trust anchor: DS and DNSKEY rrset.

Parameters

region	where to allocate key entry result.
env	module environment (scratch buffer)
ve	validator environment (verification settings)
dnskey_rrset	DNSKEY rrset to verify
ta_ds_rrset	DS rrset to verify with.
ta_dnskey_rrset	the DNSKEY rrset to verify with.
downprot	if true provide downgrade protection otherwise one algorithm is enough.
reason	reason of failure. Fixed string or alloced in scratch.
reason_bogus	EDE (RFC8914) code paired with the reason of failure.
qstate	qstate with region.

Returns

a KeyEntry. This will either contain the now trusted dnskey_rrset, a "null" key entry indicating that this DS rrset/DNSKEY pair indicate an secure end to the island of trust (i.e., unknown algorithms), or a "bad" KeyEntry if the dnskey rrset fails to verify. Note that the "null" response should generally only occur in a private algorithm scenario: normally this sort of thing is checked before fetching the matching DNSKEY rrset. if downprot is set, a key entry with an algo list is made.

References ALGO_NEEDS_MAX, packed_rrset_key::dname, packed_rrset_key::dname_len, key_entry_create_rrset(), ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, sec_status_secure, and val_verify_DNSKEY_with_TA().

val_dsset_isusable()

int val_dsset_isusable

(

struct ub_packed_rrset_key *

ds_rrset

)

Determine if DS rrset is usable for validator or not.

Returns true if the algorithms for key and DShash are supported, for at least one RR.

Parameters

ds_rrset

the newly received DS rrset.

Returns

true or false if not usable.

References ds_digest_algo_is_supported(), ds_get_digest_algo(), ds_get_key_algo(), ds_key_algo_is_supported(), rrset_get_count(), sldns_algorithms, sldns_hashes, sldns_lookup_by_id(), VERB_ALGO, verbose(), and verbosity.

val_rrset_wildcard()

int val_rrset_wildcard	(	struct ub_packed_rrset_key *	rrset,
		uint8_t **	wc,
		size_t *	wc_len
	)

Determine by looking at a signed RRset whether or not the RRset name was the result of a wildcard expansion.

If so, return the name of the generating wildcard.

Parameters

rrset	The rrset to check.
wc	the wildcard name, if the rrset was synthesized from a wildcard. unchanged if not. The wildcard name, without "*." in front, is returned. This is a pointer into the rrset owner name.
wc_len	the length of the returned wildcard name.

Returns

false if the signatures are inconsistent in indicating the wildcard status; possible spoofing of wildcard response for other responses is being tried. We lost the status which rrsig was verified after the verification routine finished, so we simply check if the signatures are consistent; inserting a fake signature is a denial of service; but in that you could also have removed the real signature anyway.

References packed_rrset_data::count, packed_rrset_key::dname, dname_count_labels(), dname_is_wild(), packed_rrset_key::dname_len, dname_remove_labels(), ub_packed_rrset_key::rk, packed_rrset_data::rrsig_count, and rrsig_get_labcount().

Referenced by dns_cache_lookup(), validate_cname_response(), and validate_positive_response().

val_chase_cname()

int val_chase_cname	(	struct query_info *	qchase,
		struct reply_info *	rep,
		size_t *	cname_skip
	)

Chase the cname to the next query name.

Parameters

qchase	the current query name, updated to next target.
rep	original message reply to look at CNAMEs.
cname_skip	the skip into the answer section. Updated to skip DNAME and CNAME to the next part of the answer.

Returns

false on error (bad rdata).

References reply_info::an_numrrsets, get_cname_target(), LDNS_RR_TYPE_CNAME, query_info::qname, query_info::qname_len, query_dname_compare(), ub_packed_rrset_key::rk, reply_info::rrsets, and packed_rrset_key::type.

val_fill_reply()

void val_fill_reply	(	struct reply_info *	chase,
		struct reply_info *	orig,
		size_t	cname_skip,
		uint8_t *	name,
		size_t	len,
		uint8_t *	signer
	)

Fill up the chased reply with the content from the original reply; as pointers to those rrsets.

Select the part after the cname_skip into the answer section, NS and AR sections that are signed with same signer.

Parameters

chase	chased reply, filled up.
orig	original reply.
cname_skip	which part of the answer section to skip. The skipped part contains CNAME(and DNAME)s that have been chased.
name	the signer name to look for.
len	length of name.
signer	signer name or NULL if an unsigned RRset is considered. If NULL, rrsets with the lookup name are copied over.

References reply_info::an_numrrsets, reply_info::ar_numrrsets, packed_rrset_key::dname, LDNS_RR_TYPE_CNAME, LDNS_RR_TYPE_DNAME, reply_info::ns_numrrsets, query_dname_compare(), ub_packed_rrset_key::rk, reply_info::rrset_count, rrset_has_signer(), reply_info::rrsets, and packed_rrset_key::type.

val_reply_remove_auth()

void val_reply_remove_auth	(	struct reply_info *	rep,
		size_t	index
	)

Remove rrset with index from reply, from the authority section.

Parameters

rep	reply to remove it from.
index	rrset to remove, must be in the authority section.

References reply_info::an_numrrsets, log_assert, reply_info::ns_numrrsets, reply_info::rrset_count, and reply_info::rrsets.

Referenced by remove_spurious_authority().

val_check_nonsecure()

void val_check_nonsecure	(	struct module_env *	env,
		struct reply_info *	rep
	)

Remove all unsigned or non-secure status rrsets from NS and AR sections.

So that unsigned data does not get let through to clients, when we have found the data to be secure.

Parameters

env	environment with cleaning options.
rep	reply to dump all nonsecure stuff out of.

References reply_info::an_numrrsets, reply_info::ar_numrrsets, module_env::cfg, lruhash_entry::data, packed_rrset_key::dname, ub_packed_rrset_key::entry, LDNS_RR_TYPE_NS, log_nametypeclass(), reply_info::ns_numrrsets, ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, reply_info::rrset_count, reply_info::rrsets, sec_status_bogus, sec_status_secure, reply_info::security, packed_rrset_key::type, config_file::val_clean_additional, VERB_ALGO, VERB_QUERY, and verbose().

val_mark_indeterminate()

void val_mark_indeterminate	(	struct reply_info *	rep,
		struct val_anchors *	anchors,
		struct rrset_cache *	r,
		struct module_env *	env
	)

Mark all unchecked rrset entries not below a trust anchor as indeterminate.

Only security==unchecked rrsets are updated.

Parameters

rep	the reply with rrsets.
anchors	the trust anchors.
r	rrset cache to store updated security status into.
env	module environment

References check_no_anchor(), lruhash_entry::data, packed_rrset_key::dname, packed_rrset_key::dname_len, ub_packed_rrset_key::entry, module_env::now, ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, reply_info::rrset_count, rrset_update_sec_status(), reply_info::rrsets, sec_status_indeterminate, sec_status_unchecked, and packed_rrset_data::security.

val_mark_insecure()

void val_mark_insecure	(	struct reply_info *	rep,
		uint8_t *	kname,
		struct rrset_cache *	r,
		struct module_env *	env
	)

Mark all unchecked rrset entries below a NULL key entry as insecure.

Only security==unchecked rrsets are updated.

Parameters

rep	the reply with rrsets.
kname	end of secure space name.
r	rrset cache to store updated security status into.
env	module environment

References lruhash_entry::data, packed_rrset_key::dname, dname_subdomain_c(), ub_packed_rrset_key::entry, module_env::now, ub_packed_rrset_key::rk, reply_info::rrset_count, rrset_update_sec_status(), reply_info::rrsets, sec_status_insecure, sec_status_unchecked, and packed_rrset_data::security.

Referenced by processValidate().

val_next_unchecked()

size_t val_next_unchecked	(	struct reply_info *	rep,
		size_t	skip
	)

Find next unchecked rrset position, return it for skip.

Parameters

rep	the original reply to look into.
skip	the skip now.

Returns

new skip, which may be at the rep->rrset_count position to signal there are no unchecked items.

References lruhash_entry::data, ub_packed_rrset_key::entry, reply_info::rrset_count, reply_info::rrsets, sec_status_unchecked, and packed_rrset_data::security.

val_find_rrset_signer()

void val_find_rrset_signer	(	struct ub_packed_rrset_key *	rrset,
		uint8_t **	sname,
		size_t *	slen
	)

Find the signer name for an RRset.

Parameters

rrset	the rrset.
sname	signer name is returned or NULL if not signed.
slen	length of sname (or 0).

References packed_rrset_data::count, lruhash_entry::data, ub_packed_rrset_key::entry, packed_rrset_data::rr_data, packed_rrset_data::rr_len, packed_rrset_data::rrsig_count, and rrsig_get_signer().

Referenced by iter_ds_toolow(), and val_find_signer().

val_classification_to_string()

const char* val_classification_to_string

(

enum val_classification

subtype

)

Get string to denote the classification result.

Parameters

subtype

from classification function.

Returns

static string to describe the classification.

References VAL_CLASS_ANY, VAL_CLASS_CNAME, VAL_CLASS_CNAMENOANSWER, VAL_CLASS_NAMEERROR, VAL_CLASS_NODATA, VAL_CLASS_POSITIVE, VAL_CLASS_REFERRAL, VAL_CLASS_UNKNOWN, and VAL_CLASS_UNTYPED.

val_blacklist()

void val_blacklist	(	struct sock_list **	blacklist,
		struct regional *	region,
		struct sock_list *	origin,
		int	cross
	)

Add existing list to blacklist.

Parameters

blacklist	the blacklist with result
region	the region where blacklist is allocated. Allocation failures are logged.
origin	origin list to add, if NULL, a cache-entry is added to the blacklist to stop cache from being used.
cross	if true this is a cross-qstate copy, and the 'origin' list is not allocated in the same region as the blacklist.

References sock_list::next, sock_list_insert(), sock_list_logentry(), sock_list_merge(), sock_list_prepend(), VERB_ALGO, verbose(), and verbosity.

Referenced by process_ds_response().

val_has_signed_nsecs()

int val_has_signed_nsecs	(	struct reply_info *	rep,
		char **	reason
	)

check if has dnssec info, and if it has signed nsecs.

gives error reason.

Parameters

rep	reply to check.
reason	returned on fail.

Returns

false if message has no signed nsecs. Can not prove negatives.

References reply_info::an_numrrsets, reply_info::ns_numrrsets, ub_packed_rrset_key::rk, reply_info::rrsets, and packed_rrset_key::type.

val_favorite_ds_algo()

int val_favorite_ds_algo

(

struct ub_packed_rrset_key *

ds_rrset

)

Return algo number for favorite (best) algorithm that we support in DS.

Parameters

ds_rrset

the DSes in this rrset are inspected and best algo chosen.

Returns

algo number or 0 if none supported. 0 is unused as algo number.

References ds_digest_algo_is_supported(), ds_get_digest_algo(), ds_key_algo_is_supported(), and rrset_get_count().

Referenced by key_matches_a_ds().

val_find_DS()

struct dns_msg* val_find_DS	(	struct module_env *	env,
		uint8_t *	nm,
		size_t	nmlen,
		uint16_t	c,
		struct regional *	region,
		uint8_t *	topname
	)

Find DS denial message in cache.

Saves new qstate allocation and allows the validator to use partial content which is not enough to construct a message for network (or user) consumption. Without SOA for example, which is a common occurrence in the unbound code since the referrals contain NSEC/NSEC3 rrs without the SOA element, thus do not allow synthesis of a full negative reply, but do allow synthesis of sufficient proof.

Parameters

env	query env with caches and time.
nm	name of DS record sought.
nmlen	length of name.
c	class of DS RR.
region	where to allocate result.
topname	name of the key that is currently in use, that will get used to validate the result, and thus no higher entries from the negative cache need to be examined.

Returns

a dns_msg on success. NULL on failure.

References reply_info::an_numrrsets, module_env::cfg, dns_msg_create(), ub_packed_rrset_key::entry, LDNS_RR_TYPE_DS, query_info::local_alias, lruhash_entry::lock, module_env::neg_cache, module_env::now, packed_rrset_copy_region(), query_info::qclass, query_info::qname, query_info::qname_len, query_info::qtype, dns_msg::rep, module_env::rrset_cache, rrset_cache_lookup(), reply_info::rrset_count, reply_info::rrsets, module_env::scratch_buffer, and val_neg_getmsg().