rrset.h File Reference

This file contains the rrset cache. More...

#include "util/storage/lruhash.h"
#include "util/storage/slabhash.h"
#include "util/data/packed_rrset.h"

Data Structures
struct	rrset_cache
	The rrset cache Thin wrapper around hashtable, like a typedef. More...

Functions
struct rrset_cache *	rrset_cache_create (struct config_file *cfg, struct alloc_cache *alloc)
	Create rrset cache. More...
void	rrset_cache_delete (struct rrset_cache *r)
	Delete rrset cache. More...
struct rrset_cache *	rrset_cache_adjust (struct rrset_cache *r, struct config_file *cfg, struct alloc_cache *alloc)
	Adjust settings of the cache to settings from the config file. More...
void	rrset_cache_touch (struct rrset_cache *r, struct ub_packed_rrset_key *key, hashvalue_type hash, rrset_id_type id)
	Touch rrset, with given pointer and id. More...
int	rrset_cache_update (struct rrset_cache *r, struct rrset_ref *ref, struct alloc_cache *alloc, time_t timenow)
	Update an rrset in the rrset cache. More...
void	rrset_cache_update_wildcard (struct rrset_cache *rrset_cache, struct ub_packed_rrset_key *rrset, uint8_t *ce, size_t ce_len, struct alloc_cache *alloc, time_t timenow)
	Update or add an rrset in the rrset cache using a wildcard dname. More...
struct ub_packed_rrset_key *	rrset_cache_lookup (struct rrset_cache *r, uint8_t *qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, uint32_t flags, time_t timenow, int wr)
	Lookup rrset. More...
int	rrset_array_lock (struct rrset_ref *ref, size_t count, time_t timenow)
	Obtain readlock on a (sorted) list of rrset references. More...
void	rrset_array_unlock (struct rrset_ref *ref, size_t count)
	Unlock array (sorted) of rrset references. More...
void	rrset_array_unlock_touch (struct rrset_cache *r, struct regional *scratch, struct rrset_ref *ref, size_t count)
	Unlock array (sorted) of rrset references and at the same time touch LRU on the rrsets. More...
void	rrset_update_sec_status (struct rrset_cache *r, struct ub_packed_rrset_key *rrset, time_t now)
	Update security status of an rrset. More...
void	rrset_check_sec_status (struct rrset_cache *r, struct ub_packed_rrset_key *rrset, time_t now)
	Looks up security status of an rrset. More...
void	rrset_cache_remove (struct rrset_cache *r, uint8_t *nm, size_t nmlen, uint16_t type, uint16_t dclass, uint32_t flags)
	Remove an rrset from the cache, by name and type and flags. More...
void	rrset_markdel (void *key)
	mark rrset to be deleted, set id=0

Detailed Description

This file contains the rrset cache.

Function Documentation

rrset_cache_create()

struct rrset_cache* rrset_cache_create	(	struct config_file *	cfg,
		struct alloc_cache *	alloc
	)

Create rrset cache.

Parameters

cfg	config settings or NULL for defaults.
alloc	initial default rrset key allocation.

Returns

: NULL on error.

References HASH_DEFAULT_MAXMEM, HASH_DEFAULT_SLABS, HASH_DEFAULT_STARTARRAY, config_file::rrset_cache_size, config_file::rrset_cache_slabs, rrset_data_delete(), rrset_markdel(), slabhash_create(), slabhash_setmarkdel(), rrset_cache::table, ub_rrset_compare(), ub_rrset_key_delete(), and ub_rrset_sizefunc().

Referenced by rrset_cache_adjust().

rrset_cache_delete()

void rrset_cache_delete

(

struct rrset_cache *

r

)

Delete rrset cache.

Parameters

r	rrset cache to delete.

References slabhash_delete(), and rrset_cache::table.

Referenced by daemon_delete(), and rrset_cache_adjust().

rrset_cache_adjust()

struct rrset_cache* rrset_cache_adjust	(	struct rrset_cache *	r,
		struct config_file *	cfg,
		struct alloc_cache *	alloc
	)

Adjust settings of the cache to settings from the config file.

May purge the cache. May recreate the cache. There may be no threading or use by other threads.

Parameters

r	rrset cache to adjust (like realloc).
cfg	config settings or NULL for defaults.
alloc	initial default rrset key allocation.

Returns

0 on error, or new rrset cache pointer on success.

References rrset_cache_create(), rrset_cache_delete(), config_file::rrset_cache_size, config_file::rrset_cache_slabs, slabhash_is_size(), and rrset_cache::table.

Referenced by context_finalize().

rrset_cache_touch()

void rrset_cache_touch	(	struct rrset_cache *	r,
		struct ub_packed_rrset_key *	key,
		hashvalue_type	hash,
		rrset_id_type	id
	)

Touch rrset, with given pointer and id.

Caller may not hold a lock on ANY rrset, this could give deadlock.

This routine is faster than a hashtable lookup: o no bin_lock is acquired. o no walk through the bin-overflow-list. o no comparison of the entry key to find it.

Parameters

r	rrset cache.
key	rrset key. Marked recently used (if it was not deleted before the lock is acquired, in that case nothing happens).
hash	hash value of the item. Please read it from the key when you have it locked. Used to find slab from slabhash.
id	used to check that the item is unchanged and not deleted.

References ub_packed_rrset_key::entry, lruhash_entry::hash, ub_packed_rrset_key::id, lruhash::lock, lruhash_entry::lock, lru_touch(), slabhash_gettable(), and rrset_cache::table.

Referenced by rrset_array_unlock_touch().

rrset_cache_update()

int rrset_cache_update	(	struct rrset_cache *	r,
		struct rrset_ref *	ref,
		struct alloc_cache *	alloc,
		time_t	timenow
	)

Update an rrset in the rrset cache.

Stores the information for later use. Will lookup if the rrset is in the cache and perform an update if necessary. If the item was present, and superior, references are returned to that. The passed item is then deallocated with rrset_parsedelete.

A superior rrset is: o rrset with better trust value. o same trust value, different rdata, newly passed rrset is inserted. If rdata is the same, TTL in the cache is updated.

Parameters

r	the rrset cache.
ref	reference (ptr and id) to the rrset. Pass reference setup for the new rrset. The reference may be changed if the cached rrset is superior. Before calling the rrset is presumed newly allocated and changeable. After calling you do not hold a lock, and the rrset is inserted in the hashtable so you need a lock to change it.
alloc	how to allocate (and deallocate) the special rrset key.
timenow	current time (to see if ttl in cache is expired).

Returns

: true if the passed reference is updated, false if it is unchanged. 0: reference unchanged, inserted in cache. 1: reference updated, item is inserted in cache. 2: reference updated, item in cache is considered superior. also the rdata is equal (but other parameters in cache are superior).

References lruhash_entry::data, packed_rrset_key::dname, ub_packed_rrset_key::entry, lruhash_entry::hash, rrset_ref::id, ub_packed_rrset_key::id, rrset_ref::key, lruhash_entry::key, LDNS_RR_TYPE_NS, lruhash_entry::lock, log_assert, need_to_update_rrset(), ub_packed_rrset_key::rk, rrsetdata_equal(), slabhash_insert(), slabhash_lookup(), rrset_cache::table, packed_rrset_key::type, and ub_packed_rrset_parsedelete().

Referenced by dns_cache_store(), iter_store_parentside_rrset(), move_into_cache(), rrset_cache_update_wildcard(), store_rrset(), and store_rrsets().

rrset_cache_update_wildcard()

void rrset_cache_update_wildcard	(	struct rrset_cache *	rrset_cache,
		struct ub_packed_rrset_key *	rrset,
		uint8_t *	ce,
		size_t	ce_len,
		struct alloc_cache *	alloc,
		time_t	timenow
	)

Update or add an rrset in the rrset cache using a wildcard dname.

Generates wildcard dname by prepending the wildcard label to the closest encloser. Will lookup if the rrset is in the cache and perform an update if necessary.

Parameters

rrset_cache	the rrset cache.
rrset	which rrset to cache as wildcard. This rrset is left untouched.
ce	the closest encloser, will be uses to generate the wildcard dname.
ce_len	the closest encloser length.
alloc	how to allocate (and deallocate) the special rrset key.
timenow	current time (to see if ttl in cache is expired).

References alloc_special_release(), packed_rrset_key::dname, packed_rrset_key::dname_len, ub_packed_rrset_key::entry, lruhash_entry::hash, rrset_ref::id, ub_packed_rrset_key::id, rrset_ref::key, LDNS_MAX_DOMAINLEN, log_err(), memdup(), packed_rrset_copy_alloc(), ub_packed_rrset_key::rk, rrset_cache_update(), and rrset_key_hash().

rrset_cache_lookup()

struct ub_packed_rrset_key* rrset_cache_lookup	(	struct rrset_cache *	r,
		uint8_t *	qname,
		size_t	qnamelen,
		uint16_t	qtype,
		uint16_t	qclass,
		uint32_t	flags,
		time_t	timenow,
		int	wr
	)

Lookup rrset.

You obtain read/write lock. You must unlock before lookup anything of else.

Parameters

r	the rrset cache.
qname	name of rrset to lookup.
qnamelen	length of name of rrset to lookup.
qtype	type of rrset to lookup (host order).
qclass	class of rrset to lookup (host order).
flags	rrset flags, or 0.
timenow	used to compare with TTL.
wr	set true to get writelock.

Returns

packed rrset key pointer. Remember to unlock the key.entry.lock. or NULL if could not be found or it was timed out.

References lruhash_entry::data, packed_rrset_key::dname, packed_rrset_key::dname_len, ub_packed_rrset_key::entry, packed_rrset_key::flags, lruhash_entry::hash, lruhash_entry::key, lruhash_entry::lock, ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, rrset_key_hash(), slabhash_lookup(), rrset_cache::table, packed_rrset_data::ttl, and packed_rrset_key::type.

Referenced by add_soa(), dns_cache_lookup(), find_add_addrs(), find_add_ds(), find_closest_of_type(), grab_nsec(), iter_lookup_parent_NS_from_cache(), load_ref(), rrset_expired_above(), and val_find_DS().

rrset_array_lock()

int rrset_array_lock	(	struct rrset_ref *	ref,
		size_t	count,
		time_t	timenow
	)

Obtain readlock on a (sorted) list of rrset references.

Checks TTLs and IDs of the rrsets and rollbacks locking if not Ok.

Parameters

ref	array of rrset references (key pointer and ID value). duplicate references are allowed and handled.
count	size of array.
timenow	used to compare with TTL.

Returns

true on success, false on a failure, which can be that some RRsets have timed out, or that they do not exist any more, the RRsets have been purged from the cache. If true, you hold readlocks on all the ref items.

References packed_rrset_data::count, lruhash_entry::data, ub_packed_rrset_key::entry, rrset_ref::id, rrset_ref::key, and rrset_array_unlock().

Referenced by dump_msg(), and invalidateQueryInCache().

rrset_array_unlock()

void rrset_array_unlock	(	struct rrset_ref *	ref,
		size_t	count
	)

Unlock array (sorted) of rrset references.

Parameters

ref	array of rrset references (key pointer and ID value). duplicate references are allowed and handled.
count	size of array.

References packed_rrset_data::count.

Referenced by dump_msg(), invalidateQueryInCache(), and rrset_array_lock().

rrset_array_unlock_touch()

void rrset_array_unlock_touch	(	struct rrset_cache *	r,
		struct regional *	scratch,
		struct rrset_ref *	ref,
		size_t	count
	)

Unlock array (sorted) of rrset references and at the same time touch LRU on the rrsets.

It needs the scratch region for temporary storage as it uses the initial locks to obtain hash values.

Parameters

r	the rrset cache. In this cache LRU is updated.
scratch	region for temporary storage of hash values. if memory allocation fails, the lru touch fails silently, but locks are released. memory errors are logged.
ref	array of rrset references (key pointer and ID value). duplicate references are allowed and handled.
count	size of array.

References packed_rrset_data::count, log_warn(), regional_alloc(), RR_COUNT_MAX, and rrset_cache_touch().

rrset_update_sec_status()

void rrset_update_sec_status	(	struct rrset_cache *	r,
		struct ub_packed_rrset_key *	rrset,
		time_t	now
	)

Update security status of an rrset.

Looks up the rrset. If found, checks if rdata is equal. If so, it will update the security, trust and rrset-ttl values. The values are only updated if security is increased (towards secure).

Parameters

r	the rrset cache.
rrset	which rrset to attempt to update. This rrset is left untouched. The rrset in the cache is updated in-place.
now	current time.

References lruhash_entry::data, ub_packed_rrset_key::entry, lruhash_entry::hash, LDNS_RR_TYPE_NS, ub_packed_rrset_key::rk, packed_rrset_data::rr_ttl, rrset_key_hash(), rrsetdata_equal(), sec_status_bogus, packed_rrset_data::security, slabhash_lookup(), rrset_cache::table, packed_rrset_data::trust, packed_rrset_data::ttl, and packed_rrset_key::type.

Referenced by val_mark_indeterminate(), and val_mark_insecure().

rrset_check_sec_status()

void rrset_check_sec_status	(	struct rrset_cache *	r,
		struct ub_packed_rrset_key *	rrset,
		time_t	now
	)

Looks up security status of an rrset.

Looks up the rrset. If found, checks if rdata is equal, and entry did not expire. If so, it will update the security, trust and rrset-ttl values.

Parameters

r	the rrset cache.
rrset	This rrset may change security status due to the cache. But its status will only improve, towards secure.
now	current time.

References lruhash_entry::data, ub_packed_rrset_key::entry, lruhash_entry::hash, ub_packed_rrset_key::rk, packed_rrset_data::rr_ttl, rrset_key_hash(), rrsetdata_equal(), sec_status_bogus, packed_rrset_data::security, slabhash_lookup(), rrset_cache::table, packed_rrset_data::trust, and packed_rrset_data::ttl.

Referenced by nsec_verify_rrset().

rrset_cache_remove()

void rrset_cache_remove	(	struct rrset_cache *	r,
		uint8_t *	nm,
		size_t	nmlen,
		uint16_t	type,
		uint16_t	dclass,
		uint32_t	flags
	)

Remove an rrset from the cache, by name and type and flags.

Parameters

r	rrset cache
nm	name of rrset
nmlen	length of name
type	type of rrset
dclass	class of rrset, host order
flags	flags of rrset, host order

References packed_rrset_key::dname, packed_rrset_key::dname_len, ub_packed_rrset_key::entry, packed_rrset_key::flags, lruhash_entry::hash, lruhash_entry::key, ub_packed_rrset_key::rk, packed_rrset_key::rrset_class, rrset_key_hash(), slabhash_remove(), rrset_cache::table, and packed_rrset_key::type.

Referenced by do_cache_remove().