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.
size_t	val_neg_get_mem (struct val_neg_cache *neg)
	see how much memory is in use by the negative cache.
void	neg_cache_delete (struct val_neg_cache *neg)
	Destroy negative cache.
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.
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.
int	val_neg_dlvlookup (struct val_neg_cache *neg, uint8_t *qname, size_t len, uint16_t qclass, struct rrset_cache *rrset_cache, uint32_t now)
	Perform a DLV style lookup During the lookup, we could find out that data has expired.
struct dns_msg *	val_neg_getmsg (struct val_neg_cache *neg, struct query_info *qinfo, struct regional *region, struct rrset_cache *rrset_cache, ldns_buffer *buf, uint32_t now)
	For the given query, try to get a reply out of the negative cache.
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.
void	neg_delete_data (struct val_neg_cache *neg, struct val_neg_data *el)
	Delete a data element from the negative cache.
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.
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.
void	val_neg_zone_take_inuse (struct val_neg_zone *zone)
	take a zone into use.

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Detailed Description

This file contains helper functions for the validator module.

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

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Function Documentation

struct val_neg_cache* val_neg_create	(	struct config_file *	cfg,
		size_t	maxiter
	)			[read]

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().

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.

Referenced by val_get_mem().

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().

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(), rbtree_t::count, packed_rrset_key::dname, packed_rrset_key::dname_len, dname_subdomain_c(), val_neg_cache::lock, log_err(), log_nametypeclass(), val_neg_zone::name, neg_create_zone(), neg_delete_zone(), neg_find_zone(), neg_insert_data(), neg_make_space(), reply_info::ns_numrrsets, reply_find_soa(), reply_has_nsec(), ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, reply_info::rrsets, val_neg_zone::tree, packed_rrset_key::type, val_neg_zone_take_inuse(), and VERB_ALGO.

Referenced by process_dlv_response().

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(), rbtree_t::count, packed_rrset_key::dname, dname_subdomain_c(), val_neg_cache::lock, log_err(), log_nametypeclass(), val_neg_zone::name, neg_create_zone(), neg_delete_zone(), neg_find_zone(), neg_insert_data(), neg_make_space(), reply_info::ns_numrrsets, reply_nsec_signer(), ub_packed_rrset_key::rk, reply_info::rrsets, val_neg_zone::tree, packed_rrset_key::type, val_neg_zone_take_inuse(), and VERB_ALGO.

Referenced by processQueryResponse().

int val_neg_dlvlookup	(	struct val_neg_cache *	neg,
		uint8_t *	qname,
		size_t	len,
		uint16_t	qclass,
		struct rrset_cache *	rrset_cache,
		uint32_t	now
	)

Perform a DLV style lookup During the lookup, we could find out that data has expired.

In that case the neg_cache entries are removed, and lookup fails.

Parameters:

	neg,:	negative cache.
	qname,:	name to look for
	len,:	length of qname.
	qclass,:	class to look in.
	rrset_cache,:	the rrset cache, for NSEC lookups.
	now,:	current time for ttl checks.

Returns:

0 on error 0 if no proof of negative 1 if indeed negative was proven thus, qname DLV qclass does not exist.

References lruhash_entry::data, val_neg_zone::dclass, dname_count_labels(), ub_packed_rrset_key::entry, val_neg_data::in_use, val_neg_zone::in_use, val_neg_data::labs, val_neg_data::len, lruhash_entry::lock, val_neg_cache::lock, log_nametypeclass(), val_neg_data::name, val_neg_zone::name, neg_closest_data(), neg_closest_zone_parent(), neg_delete_data(), neg_lru_touch(), val_neg_zone::nsec3_hash, nsec_proves_nodata(), PACKED_RRSET_NSEC_AT_APEX, val_neg_data::parent, val_neg_zone::parent, query_info::qclass, query_info::qname, query_info::qtype, query_dname_compare(), rrset_cache_lookup(), sec_status_secure, packed_rrset_data::security, packed_rrset_data::ttl, val_nsec_proves_name_error(), VERB_ALGO, and verbose().

Referenced by processDLVLookup(), and val_dlv_init().

struct dns_msg* val_neg_getmsg	(	struct val_neg_cache *	neg,
		struct query_info *	qinfo,
		struct regional *	region,
		struct rrset_cache *	rrset_cache,
		ldns_buffer *	buf,
		uint32_t	now
	)			[read]

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.

Returns:

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

References dname_count_labels(), dname_remove_label(), dns_msg_authadd(), dns_msg_create(), grab_nsec(), val_neg_zone::in_use, val_neg_cache::lock, neg_closest_zone_parent(), neg_nsec3_proof_ds(), val_neg_zone::parent, query_info::qclass, query_info::qname, query_info::qname_len, and query_info::qtype.

Referenced by processInitRequest().

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, log_assert, log_err(), log_nametypeclass(), memdup(), val_neg_data::name, neg_closest_data_parent(), neg_data_chain(), neg_lru_front(), neg_lru_touch(), val_neg_data::node, nsec3_get_params(), val_neg_zone::nsec3_hash, val_neg_zone::nsec3_iter, val_neg_zone::nsec3_salt, val_neg_zone::nsec3_saltlen, 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, wipeout(), and val_neg_data::zone.

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

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_t::count, val_neg_data::count, val_neg_data::in_use, 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(), remove_item(), val_neg_dlvlookup(), and wipeout().

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

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_t::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().

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

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, dname_count_labels(), val_neg_zone::labs, 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().

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().