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

#include "config.h"
#include "validator/val_neg.h"
#include "validator/val_nsec.h"
#include "validator/val_nsec3.h"
#include "validator/val_utils.h"
#include "util/data/dname.h"
#include "util/data/msgreply.h"
#include "util/log.h"
#include "util/net_help.h"
#include "util/config_file.h"
#include "services/cache/rrset.h"
#include "services/cache/dns.h"
#include "sldns/rrdef.h"
#include "sldns/sbuffer.h"

Macros
#define	NSEC3_SHA_LEN 20

Functions
int	val_neg_data_compare (const void a, const void b)
	Comparison function for rbtree val neg data elements.

int	val_neg_zone_compare (const void a, const void b)
	Comparison function for rbtree val neg zone elements.

struct val_neg_cache *	val_neg_create (struct config_file *cfg, size_t maxiter)
	Create negative cache. More...

size_t	val_neg_get_mem (struct val_neg_cache *neg)
	see how much memory is in use by the negative cache. More...

static void	neg_clear_datas (rbnode_type n, void ATTR_UNUSED(arg))
	clear datas on cache deletion

static void	neg_clear_zones (rbnode_type n, void ATTR_UNUSED(arg))
	clear zones on cache deletion

void	neg_cache_delete (struct val_neg_cache *neg)
	Destroy negative cache. More...

static void	neg_lru_front (struct val_neg_cache neg, struct val_neg_data data)
	Put data element at the front of the LRU list. More...

static void	neg_lru_remove (struct val_neg_cache neg, struct val_neg_data data)
	Remove data element from LRU list. More...

static void	neg_lru_touch (struct val_neg_cache neg, struct val_neg_data data)
	Touch LRU for data element, put it at the start of the LRU list. More...

static void	neg_delete_zone (struct val_neg_cache neg, struct val_neg_zone z)
	Delete a zone element from the negative cache. More...

void	neg_delete_data (struct val_neg_cache neg, struct val_neg_data el)
	Delete a data element from the negative cache. More...

static void	neg_make_space (struct val_neg_cache *neg, size_t need)
	Create more space in negative cache The oldest elements are deleted until enough space is present. More...

struct val_neg_zone *	neg_find_zone (struct val_neg_cache neg, uint8_t nm, size_t len, uint16_t dclass)
	Find the given zone, from the SOA owner name and class Does not do locking. More...

static struct val_neg_data *	neg_find_data (struct val_neg_zone zone, uint8_t nm, size_t len, int labs)
	Find the given data. More...

static size_t	calc_data_need (struct reply_info *rep)
	Calculate space needed for the data and all its parents. More...

static size_t	calc_zone_need (uint8_t *d, size_t len)
	Calculate space needed for zone and all its parents. More...

static struct val_neg_zone *	neg_closest_zone_parent (struct val_neg_cache neg, uint8_t nm, size_t nm_len, int labs, uint16_t qclass)
	Find closest existing parent zone of the given name. More...

static struct val_neg_data *	neg_closest_data_parent (struct val_neg_zone zone, uint8_t nm, size_t nm_len, int labs)
	Find closest existing parent data for the given name. More...

static struct val_neg_zone *	neg_setup_zone_node (uint8_t *nm, size_t nm_len, int labs, uint16_t dclass)
	Create a single zone node. More...

static struct val_neg_zone *	neg_zone_chain (uint8_t nm, size_t nm_len, int labs, uint16_t dclass, struct val_neg_zone parent)
	Create a linked list of parent zones, starting at longname ending on the parent (can be NULL, creates to the root). More...

void	val_neg_zone_take_inuse (struct val_neg_zone *zone)
	take a zone into use. More...

struct val_neg_zone *	neg_create_zone (struct val_neg_cache neg, uint8_t nm, size_t nm_len, uint16_t dclass)
	Create a new zone. More...

static struct ub_packed_rrset_key *	reply_find_soa (struct reply_info *rep)
	find zone name of message, returns the SOA record

static int	reply_has_nsec (struct reply_info *rep)
	see if the reply has NSEC records worthy of caching

static struct val_neg_data *	neg_setup_data_node (uint8_t *nm, size_t nm_len, int labs)
	Create single node of data element. More...

static struct val_neg_data *	neg_data_chain (uint8_t nm, size_t nm_len, int labs, struct val_neg_data parent)
	Create chain of data element and parents. More...

static void	wipeout (struct val_neg_cache neg, struct val_neg_zone zone, struct val_neg_data el, struct ub_packed_rrset_key nsec)
	Remove NSEC records between start and end points. More...

void	neg_insert_data (struct val_neg_cache neg, struct val_neg_zone zone, struct ub_packed_rrset_key *nsec)
	Insert data into the data tree of a zone Does not do locking. More...

static uint8_t *	reply_nsec_signer (struct reply_info rep, size_t signer_len, uint16_t *dclass)
	see if the reply has signed NSEC records and return the signer

void	val_neg_addreply (struct val_neg_cache neg, struct reply_info rep)
	Insert NSECs from this message into the negative cache for reference. More...

static int	neg_closest_data (struct val_neg_zone zone, uint8_t qname, size_t len, int labs, struct val_neg_data **data)
	Lookup closest data record. More...

void	val_neg_addreferral (struct val_neg_cache neg, struct reply_info rep, uint8_t *zone_name)
	Insert NSECs from this referral into the negative cache for reference. More...

static int	nsec3_no_type (struct ub_packed_rrset_key *k, uint16_t t)
	Check that an NSEC3 rrset does not have a type set. More...

static struct ub_packed_rrset_key *	grab_nsec (struct rrset_cache rrset_cache, uint8_t qname, size_t qname_len, uint16_t qtype, uint16_t qclass, uint32_t flags, struct regional *region, int checkbit, uint16_t checktype, time_t now)
	See if rrset exists in rrset cache. More...

static struct ub_packed_rrset_key *	neg_find_nsec (struct val_neg_cache neg_cache, uint8_t qname, size_t qname_len, uint16_t qclass, struct rrset_cache rrset_cache, time_t now, struct regional region)
	Get best NSEC record for qname. More...

static struct val_neg_data *	neg_find_nsec3_ce (struct val_neg_zone zone, uint8_t qname, size_t qname_len, int qlabs, sldns_buffer buf, uint8_t hashnc, size_t *nclen)
	find nsec3 closest encloser in neg cache

static int	neg_params_ok (struct val_neg_zone zone, struct ub_packed_rrset_key rrset)
	check nsec3 parameters on nsec3 rrset with current zone values

static struct ub_packed_rrset_key *	neg_nsec3_getnc (struct val_neg_zone zone, uint8_t hashnc, size_t nclen, struct rrset_cache rrset_cache, struct regional region, time_t now, uint8_t *b32, size_t maxb32)
	get next closer for nsec3 proof

static struct dns_msg *	neg_nsec3_proof_ds (struct val_neg_zone zone, uint8_t qname, size_t qname_len, int qlabs, sldns_buffer buf, struct rrset_cache rrset_cache, struct regional region, time_t now, uint8_t topname)
	neg cache nsec3 proof procedure

static int	add_soa (struct rrset_cache rrset_cache, time_t now, struct regional region, struct dns_msg msg, struct val_neg_zone zone)
	Add SOA record for external responses. More...

struct dns_msg *	val_neg_getmsg (struct val_neg_cache neg, struct query_info qinfo, struct regional region, struct rrset_cache rrset_cache, sldns_buffer buf, time_t now, int addsoa, uint8_t topname, struct config_file *cfg)
	For the given query, try to get a reply out of the negative cache. More...

Detailed Description

This file contains helper functions for the validator module.

The functions help with aggressive negative caching. This creates new denials of existence, and proofs for absence of types from cached NSEC records.

Function Documentation

◆ val_neg_create()

struct val_neg_cache* val_neg_create	(	struct config_file *	cfg,
		size_t	maxiter
	)

Create negative cache.

Parameters

cfg	config options.
maxiter	max nsec3 iterations allowed.

Returns: neg cache, empty or NULL on failure.

References val_neg_cache::lock, log_err(), val_neg_cache::max, config_file::neg_cache_size, val_neg_cache::nsec3_max_iter, rbtree_init(), val_neg_cache::tree, and val_neg_zone_compare().

Referenced by neg_test(), and val_apply_cfg().

◆ val_neg_get_mem()

size_t val_neg_get_mem ( struct val_neg_cache * neg )

see how much memory is in use by the negative cache.

Parameters

neg	negative cache

Returns: number of bytes in use.

References val_neg_cache::lock, and val_neg_cache::use.

◆ neg_cache_delete()

void neg_cache_delete ( struct val_neg_cache * neg )

Destroy negative cache.

There must no longer be any other threads.

Parameters

neg	negative cache.

References val_neg_cache::lock, neg_clear_zones(), traverse_postorder(), and val_neg_cache::tree.

Referenced by neg_test(), and val_deinit().

◆ neg_lru_front()

static void neg_lru_front	(	struct val_neg_cache *	neg,
		struct val_neg_data *	data
	)

static

Put data element at the front of the LRU list.

Parameters

neg	negative cache with LRU start and end.
data	this data is fronted.

References val_neg_cache::first, val_neg_cache::last, val_neg_data::next, and val_neg_data::prev.

Referenced by neg_insert_data(), and neg_lru_touch().

◆ neg_lru_remove()

static void neg_lru_remove	(	struct val_neg_cache *	neg,
		struct val_neg_data *	data
	)

static

Remove data element from LRU list.

Parameters

neg	negative cache with LRU start and end.
data	this data is removed from the list.

References val_neg_cache::first, val_neg_cache::last, val_neg_data::next, and val_neg_data::prev.

Referenced by neg_delete_data(), and neg_lru_touch().

◆ neg_lru_touch()

static void neg_lru_touch	(	struct val_neg_cache *	neg,
		struct val_neg_data *	data
	)

static

Touch LRU for data element, put it at the start of the LRU list.

Parameters

neg	negative cache with LRU start and end.
data	this data is used.

References val_neg_cache::first, neg_lru_front(), and neg_lru_remove().

Referenced by neg_insert_data().

◆ neg_delete_zone()

static void neg_delete_zone	(	struct val_neg_cache *	neg,
		struct val_neg_zone *	z
	)

static

Delete a zone element from the negative cache.

May delete other zone elements to keep tree coherent, or only mark the element as 'not in use'.

Parameters

neg	negative cache.
z	zone element to delete.

References val_neg_zone::count, val_neg_zone::in_use, val_neg_zone::len, log_assert, val_neg_zone::name, val_neg_zone::node, val_neg_zone::nsec3_salt, val_neg_zone::parent, rbtree_delete(), val_neg_cache::tree, and val_neg_cache::use.

Referenced by neg_delete_data().

◆ neg_delete_data()

void neg_delete_data	(	struct val_neg_cache *	neg,
		struct val_neg_data *	el
	)

Delete a data element from the negative cache.

May delete other data elements to keep tree coherent, or only mark the element as 'not in use'. Does not do locking.

Parameters

neg	negative cache.
el	data element to delete.

References rbtree_type::count, val_neg_data::count, val_neg_cache::first, val_neg_data::in_use, val_neg_cache::last, val_neg_data::len, log_assert, val_neg_data::name, neg_delete_zone(), neg_lru_remove(), val_neg_data::node, val_neg_data::parent, rbtree_delete(), val_neg_zone::tree, val_neg_cache::use, and val_neg_data::zone.

Referenced by neg_make_space(), and remove_item().

◆ neg_make_space()

static void neg_make_space	(	struct val_neg_cache *	neg,
		size_t	need
	)

static

Create more space in negative cache The oldest elements are deleted until enough space is present.

Empty zones are deleted.

Parameters

neg	negative cache.
need	how many bytes are needed.

References val_neg_cache::last, val_neg_cache::max, neg_delete_data(), and val_neg_cache::use.

Referenced by val_neg_addreferral(), and val_neg_addreply().

◆ neg_find_zone()

struct val_neg_zone* neg_find_zone	(	struct val_neg_cache *	neg,
		uint8_t *	nm,
		size_t	len,
		uint16_t	dclass
	)

Find the given zone, from the SOA owner name and class Does not do locking.

Parameters

neg	negative cache
nm	what to look for.
len	length of nm
dclass	class to look for.

Returns: zone or NULL if not found.

References val_neg_zone::dclass, dname_count_labels(), rbnode_type::key, val_neg_zone::labs, val_neg_zone::len, val_neg_zone::name, val_neg_zone::node, rbtree_search(), and val_neg_cache::tree.

Referenced by add_item(), val_neg_addreferral(), and val_neg_addreply().

◆ neg_find_data()

static struct val_neg_data* neg_find_data	(	struct val_neg_zone *	zone,
		uint8_t *	nm,
		size_t	len,
		int	labs
	)

static

Find the given data.

Parameters

zone	negative zone
nm	what to look for.
len	length of nm
labs	labels in nm

Returns: data or NULL if not found.

References rbnode_type::key, val_neg_data::labs, val_neg_data::len, val_neg_data::name, val_neg_data::node, rbtree_search(), val_neg_zone::tree, and val_neg_data::zone.

◆ calc_data_need()

static size_t calc_data_need ( struct reply_info * rep )

static

Calculate space needed for the data and all its parents.

Parameters

rep	NSEC entries.

Returns: size.

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

Referenced by val_neg_addreferral(), and val_neg_addreply().

◆ calc_zone_need()

static size_t calc_zone_need	(	uint8_t *	d,
		size_t	len
	)

static

Calculate space needed for zone and all its parents.

Parameters

d	name of zone
len	length of name

Returns: size.

References dname_is_root(), dname_remove_label(), val_neg_zone::len, and log_assert.

Referenced by val_neg_addreferral(), and val_neg_addreply().

◆ neg_closest_zone_parent()

static struct val_neg_zone* neg_closest_zone_parent	(	struct val_neg_cache *	neg,
		uint8_t *	nm,
		size_t	nm_len,
		int	labs,
		uint16_t	qclass
	)

static

Find closest existing parent zone of the given name.

Parameters

neg	negative cache.
nm	name to look for
nm_len	length of nm
labs	labelcount of nm.
qclass	class.

Returns: the zone or NULL if none found.

References val_neg_zone::dclass, dname_lab_cmp(), rbnode_type::key, val_neg_zone::labs, val_neg_zone::len, val_neg_zone::name, val_neg_zone::node, val_neg_zone::parent, rbtree_find_less_equal(), and val_neg_cache::tree.

Referenced by neg_create_zone(), and neg_find_nsec().

◆ neg_closest_data_parent()

static struct val_neg_data* neg_closest_data_parent	(	struct val_neg_zone *	zone,
		uint8_t *	nm,
		size_t	nm_len,
		int	labs
	)

static

Find closest existing parent data for the given name.

Parameters

zone	to look in.
nm	name to look for
nm_len	length of nm
labs	labelcount of nm.

Returns: the data or NULL if none found.

References dname_lab_cmp(), rbnode_type::key, val_neg_data::labs, val_neg_data::len, val_neg_data::name, val_neg_data::node, val_neg_data::parent, rbtree_find_less_equal(), val_neg_zone::tree, and val_neg_data::zone.

Referenced by neg_insert_data().

◆ neg_setup_zone_node()

static struct val_neg_zone* neg_setup_zone_node	(	uint8_t *	nm,
		size_t	nm_len,
		int	labs,
		uint16_t	dclass
	)

static

Create a single zone node.

Parameters

nm	name for zone (copied)
nm_len	length of name
labs	labels in name.
dclass	class of zone, host order.

Returns: new zone or NULL on failure

References val_neg_zone::dclass, rbnode_type::key, val_neg_zone::labs, val_neg_zone::len, memdup(), val_neg_zone::name, val_neg_zone::node, rbtree_init(), val_neg_zone::tree, and val_neg_data_compare().

Referenced by neg_zone_chain().

◆ neg_zone_chain()

static struct val_neg_zone* neg_zone_chain	(	uint8_t *	nm,
		size_t	nm_len,
		int	labs,
		uint16_t	dclass,
		struct val_neg_zone *	parent
	)

static

Create a linked list of parent zones, starting at longname ending on the parent (can be NULL, creates to the root).

Parameters

nm	name for lowest in chain
nm_len	length of name
labs	labels in name.
dclass	class of zone.
parent	NULL for to root, else so it fits under here.

Returns: zone; a chain of zones and their parents up to the parent. or NULL on malloc failure

References val_neg_zone::dclass, dname_remove_label(), val_neg_zone::labs, val_neg_zone::name, neg_setup_zone_node(), and val_neg_zone::parent.

Referenced by neg_create_zone().

◆ val_neg_zone_take_inuse()

void val_neg_zone_take_inuse ( struct val_neg_zone * zone )

take a zone into use.

increases counts of parents. Does not do locking.

Parameters

zone	zone to take into use.

References val_neg_zone::count, val_neg_zone::in_use, and val_neg_zone::parent.

Referenced by add_item(), val_neg_addreferral(), and val_neg_addreply().

◆ neg_create_zone()

struct val_neg_zone* neg_create_zone	(	struct val_neg_cache *	neg,
		uint8_t *	nm,
		size_t	nm_len,
		uint16_t	dclass
	)

Create a new zone.

Does not do locking.

Parameters

neg	negative cache
nm	what to look for.
nm_len	length of name.
dclass	class of zone, host order.

Returns: zone or NULL if out of memory.

References val_neg_zone::count, val_neg_zone::dclass, dname_count_labels(), val_neg_zone::labs, val_neg_zone::len, log_assert, val_neg_zone::name, neg_closest_zone_parent(), neg_zone_chain(), val_neg_zone::node, val_neg_zone::parent, query_dname_compare(), rbtree_insert(), val_neg_cache::tree, and val_neg_cache::use.

Referenced by add_item(), val_neg_addreferral(), and val_neg_addreply().

◆ neg_setup_data_node()

static struct val_neg_data* neg_setup_data_node	(	uint8_t *	nm,
		size_t	nm_len,
		int	labs
	)

static

Create single node of data element.

Parameters

nm	name (copied)
nm_len	length of name
labs	labels in name.

Returns: element with name nm, or NULL malloc failure.

References rbnode_type::key, val_neg_data::labs, val_neg_data::len, memdup(), val_neg_data::name, and val_neg_data::node.

Referenced by neg_data_chain().

◆ neg_data_chain()

static struct val_neg_data* neg_data_chain	(	uint8_t *	nm,
		size_t	nm_len,
		int	labs,
		struct val_neg_data *	parent
	)

static

Create chain of data element and parents.

Parameters

nm	name
nm_len	length of name
labs	labels in name.
parent	up to where to make, if NULL up to root label.

Returns: lowest element with name nm, or NULL malloc failure.

References dname_remove_label(), val_neg_data::labs, val_neg_data::name, neg_setup_data_node(), val_neg_data::parent, and val_neg_data::prev.

Referenced by neg_insert_data().

◆ wipeout()

static void wipeout	(	struct val_neg_cache *	neg,
		struct val_neg_zone *	zone,
		struct val_neg_data *	el,
		struct ub_packed_rrset_key *	nsec
	)

static

Remove NSEC records between start and end points.

By walking the tree, the tree is sorted canonically.

Parameters

neg	negative cache.
zone	the zone
el	element to start walking at.
nsec	the nsec record with the end point

References packed_rrset_data::count, ub_packed_rrset_key::rk, packed_rrset_data::rr_len, and packed_rrset_key::type.

◆ neg_insert_data()

void neg_insert_data	(	struct val_neg_cache *	neg,
		struct val_neg_zone *	zone,
		struct ub_packed_rrset_key *	nsec
	)

Insert data into the data tree of a zone Does not do locking.

Parameters

neg	negative cache
zone	zone to insert into
nsec	record to insert.

References val_neg_data::count, lruhash_entry::data, packed_rrset_key::dname, dname_count_labels(), packed_rrset_key::dname_len, ub_packed_rrset_key::entry, val_neg_data::in_use, val_neg_data::labs, val_neg_data::len, log_assert, log_err(), log_nametypeclass(), val_neg_data::name, neg_closest_data_parent(), neg_data_chain(), neg_lru_front(), neg_lru_touch(), val_neg_data::node, val_neg_data::parent, query_dname_compare(), rbtree_insert(), ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, packed_rrset_data::rrsig_count, sec_status_secure, sec_status_unchecked, packed_rrset_data::security, val_neg_zone::tree, packed_rrset_key::type, val_neg_cache::use, VERB_ALGO, and val_neg_data::zone.

◆ val_neg_addreply()

void val_neg_addreply	(	struct val_neg_cache *	neg,
		struct reply_info *	rep
	)

Insert NSECs from this message into the negative cache for reference.

Parameters

neg	negative cache
rep	reply with NSECs. Errors are ignored, means that storage is omitted.

References reply_info::an_numrrsets, calc_data_need(), calc_zone_need(), packed_rrset_key::dname, packed_rrset_key::dname_len, LDNS_RR_TYPE_SOA, val_neg_cache::lock, log_err(), log_nametypeclass(), neg_create_zone(), neg_find_zone(), neg_make_space(), reply_info::ns_numrrsets, reply_find_soa(), reply_has_nsec(), reply_nsec_signer(), ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, reply_info::rrsets, packed_rrset_key::type, val_neg_zone_take_inuse(), and VERB_ALGO.

◆ neg_closest_data()

static int neg_closest_data	(	struct val_neg_zone *	zone,
		uint8_t *	qname,
		size_t	len,
		int	labs,
		struct val_neg_data **	data
	)

static

Lookup closest data record.

For NSEC denial.

Parameters

zone	zone to look in
qname	name to look for.
len	length of name
labs	labels in name
data	data element, exact or smaller or NULL

Returns: true if exact match.

References rbnode_type::key, val_neg_data::labs, val_neg_data::len, val_neg_data::name, val_neg_data::node, rbtree_find_less_equal(), val_neg_zone::tree, and val_neg_data::zone.

Referenced by neg_find_nsec(), and neg_nsec3_getnc().

◆ val_neg_addreferral()

void val_neg_addreferral	(	struct val_neg_cache *	neg,
		struct reply_info *	rep,
		uint8_t *	zone
	)

Insert NSECs from this referral into the negative cache for reference.

Parameters

neg	negative cache
rep	referral reply with NS, NSECs.
zone	bailiwick for the referral. Errors are ignored, means that storage is omitted.

References reply_info::an_numrrsets, calc_data_need(), calc_zone_need(), val_neg_zone::dclass, dname_subdomain_c(), LDNS_RR_TYPE_NS, val_neg_cache::lock, log_err(), log_nametypeclass(), neg_create_zone(), neg_find_zone(), neg_make_space(), reply_info::ns_numrrsets, reply_nsec_signer(), ub_packed_rrset_key::rk, reply_info::rrsets, packed_rrset_key::type, val_neg_zone_take_inuse(), and VERB_ALGO.

◆ nsec3_no_type()

static int nsec3_no_type	(	struct ub_packed_rrset_key *	k,
		uint16_t	t
	)

static

Check that an NSEC3 rrset does not have a type set.

None of the nsec3s in a hash-collision are allowed to have the type. (since we do not know which one is the nsec3 looked at, flags, ..., we ignore the cached item and let it bypass negative caching).

Parameters

k	the nsec3 rrset to check.
t	type to check

Returns: true if no RRs have the type.

References val_neg_zone::count, lruhash_entry::data, ub_packed_rrset_key::entry, and nsec3_has_type().

◆ grab_nsec()

static struct ub_packed_rrset_key* grab_nsec	(	struct rrset_cache *	rrset_cache,
		uint8_t *	qname,
		size_t	qname_len,
		uint16_t	qtype,
		uint16_t	qclass,
		uint32_t	flags,
		struct regional *	region,
		int	checkbit,
		uint16_t	checktype,
		time_t	now
	)

static

See if rrset exists in rrset cache.

If it does, the bit is checked, and if not expired, it is returned allocated in region.

Parameters

rrset_cache	rrset cache
qname	to lookup rrset name
qname_len	length of qname.
qtype	type of rrset to lookup, host order
qclass	class of rrset to lookup, host order
flags	flags for rrset to lookup
region	where to alloc result
checkbit	if true, a bit in the nsec typemap is checked for absence.
checktype	which bit to check
now	to check ttl against

Returns: rrset or NULL

References lruhash_entry::data, ub_packed_rrset_key::entry, lruhash_entry::lock, rrset_cache_lookup(), packed_rrset_data::rrsig_count, sec_status_secure, sec_status_unchecked, packed_rrset_data::security, and packed_rrset_data::ttl.

Referenced by neg_find_nsec(), and neg_nsec3_getnc().

◆ neg_find_nsec()

static struct ub_packed_rrset_key* neg_find_nsec	(	struct val_neg_cache *	neg_cache,
		uint8_t *	qname,
		size_t	qname_len,
		uint16_t	qclass,
		struct rrset_cache *	rrset_cache,
		time_t	now,
		struct regional *	region
	)

static

Get best NSEC record for qname.

Might be matching, covering or totally useless.

Parameters

neg_cache	neg cache
qname	to lookup rrset name
qname_len	length of qname.
qclass	class of rrset to lookup, host order
rrset_cache	rrset cache
now	to check ttl against
region	where to alloc result

Returns: rrset or NULL

References dname_count_labels(), grab_nsec(), val_neg_zone::in_use, val_neg_data::in_use, val_neg_data::len, val_neg_cache::lock, val_neg_zone::name, val_neg_data::name, neg_closest_data(), neg_closest_zone_parent(), val_neg_zone::nsec3_hash, PACKED_RRSET_NSEC_AT_APEX, val_neg_zone::parent, query_dname_compare(), RBTREE_NULL, rbtree_previous(), and val_neg_data::zone.

◆ add_soa()

static int add_soa	(	struct rrset_cache *	rrset_cache,
		time_t	now,
		struct regional *	region,
		struct dns_msg *	msg,
		struct val_neg_zone *	zone
	)

static

Add SOA record for external responses.

Parameters

rrset_cache	to look into.
now	current time.
region	where to perform the allocation
msg	current msg with NSEC.
zone	val_neg_zone if we have one.

Returns: false on lookup or alloc failure.

References val_neg_zone::dclass, dns_msg_authadd(), ub_packed_rrset_key::entry, LDNS_RR_TYPE_SOA, val_neg_zone::len, lruhash_entry::lock, val_neg_zone::name, PACKED_RRSET_SOA_NEG, dns_msg::rep, reply_nsec_signer(), and rrset_cache_lookup().

◆ val_neg_getmsg()

struct dns_msg* val_neg_getmsg	(	struct val_neg_cache *	neg,
		struct query_info *	qinfo,
		struct regional *	region,
		struct rrset_cache *	rrset_cache,
		struct sldns_buffer *	buf,
		time_t	now,
		int	addsoa,
		uint8_t *	topname,
		struct config_file *	cfg
	)

For the given query, try to get a reply out of the negative cache.

The reply still needs to be validated.

Parameters

neg	negative cache.
qinfo	query
region	where to allocate reply.
rrset_cache	rrset cache.
buf	temporary buffer.
now	to check TTLs against.
addsoa	if true, produce result for external consumption. if false, do not add SOA - for unbound-internal consumption.
topname	do not look higher than this name, so that the result cannot be taken from a zone above the current trust anchor. Which could happen with multiple islands of trust. if NULL, then no trust anchor is used, but also the algorithm becomes more conservative, especially for opt-out zones, since the receiver may have a trust-anchor below the optout and thus the optout cannot be used to create a proof from the negative cache.
cfg	config options.

Returns: a reply message if something was found. This reply may still need validation. NULL if nothing found (or out of memory).

References LDNS_MAX_DOMAINLEN.

Referenced by val_find_DS().

Macros

Functions

Detailed Description

Function Documentation

◆ val_neg_create()

◆ val_neg_get_mem()

◆ neg_cache_delete()

◆ neg_lru_front()

◆ neg_lru_remove()

◆ neg_lru_touch()

◆ neg_delete_zone()

◆ neg_delete_data()

◆ neg_make_space()

◆ neg_find_zone()

◆ neg_find_data()

◆ calc_data_need()

◆ calc_zone_need()

◆ neg_closest_zone_parent()

◆ neg_closest_data_parent()

◆ neg_setup_zone_node()

◆ neg_zone_chain()

◆ val_neg_zone_take_inuse()

◆ neg_create_zone()

◆ neg_setup_data_node()

◆ neg_data_chain()

◆ wipeout()

◆ neg_insert_data()

◆ val_neg_addreply()

◆ neg_closest_data()

◆ val_neg_addreferral()

◆ nsec3_no_type()

◆ grab_nsec()

◆ neg_find_nsec()

◆ add_soa()

◆ val_neg_getmsg()