val_neg.h File Reference

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

#include "util/locks.h"
#include "util/rbtree.h"

Data Structures
struct	val_neg_cache
	The negative cache. More...
struct	val_neg_zone
	Per Zone aggressive negative caching data. More...
struct	val_neg_data
	Data element for aggressive negative caching. More...

Functions
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...
void	neg_cache_delete (struct val_neg_cache *neg)
	Destroy negative cache. More...
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.
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...
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. More...
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. 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...
void	neg_delete_data (struct val_neg_cache *neg, struct val_neg_data *el)
	Delete a data element from the negative cache. 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...
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...
void	val_neg_zone_take_inuse (struct val_neg_zone *zone)
	take a zone into use. 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().

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.

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.

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().

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.

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_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_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().

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().