danicoin/external/unbound/services/cache/rrset.h
Erik de Castro Lopo a85b5759f3 Upgrade unbound library
These files were pulled from the 1.6.3 release tarball.

This new version builds against OpenSSL version 1.1 which will be
the default in the new Debian Stable which is due to be released
RealSoonNow (tm).
2017-06-17 23:04:00 +10:00

231 lines
9 KiB
C

/*
* services/cache/rrset.h - Resource record set cache.
*
* Copyright (c) 2007, NLnet Labs. All rights reserved.
*
* This software is open source.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the NLNET LABS nor the names of its contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* \file
*
* This file contains the rrset cache.
*/
#ifndef SERVICES_CACHE_RRSET_H
#define SERVICES_CACHE_RRSET_H
#include "util/storage/lruhash.h"
#include "util/storage/slabhash.h"
#include "util/data/packed_rrset.h"
struct config_file;
struct alloc_cache;
struct rrset_ref;
struct regional;
/**
* The rrset cache
* Thin wrapper around hashtable, like a typedef.
*/
struct rrset_cache {
/** uses partitioned hash table */
struct slabhash table;
};
/**
* Create rrset cache
* @param cfg: config settings or NULL for defaults.
* @param alloc: initial default rrset key allocation.
* @return: NULL on error.
*/
struct rrset_cache* rrset_cache_create(struct config_file* cfg,
struct alloc_cache* alloc);
/**
* Delete rrset cache
* @param r: rrset cache to delete.
*/
void rrset_cache_delete(struct rrset_cache* r);
/**
* 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.
* @param r: rrset cache to adjust (like realloc).
* @param cfg: config settings or NULL for defaults.
* @param alloc: initial default rrset key allocation.
* @return 0 on error, or new rrset cache pointer on success.
*/
struct rrset_cache* rrset_cache_adjust(struct rrset_cache* r,
struct config_file* cfg, struct alloc_cache* alloc);
/**
* 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.
*
* @param r: rrset cache.
* @param key: rrset key. Marked recently used (if it was not deleted
* before the lock is acquired, in that case nothing happens).
* @param hash: hash value of the item. Please read it from the key when
* you have it locked. Used to find slab from slabhash.
* @param id: used to check that the item is unchanged and not deleted.
*/
void rrset_cache_touch(struct rrset_cache* r, struct ub_packed_rrset_key* key,
hashvalue_type hash, rrset_id_type id);
/**
* 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.
*
* @param r: the rrset cache.
* @param 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.
* Afer calling you do not hold a lock, and the rrset is inserted in
* the hashtable so you need a lock to change it.
* @param alloc: how to allocate (and deallocate) the special rrset key.
* @param timenow: current time (to see if ttl in cache is expired).
* @return: 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).
*/
int rrset_cache_update(struct rrset_cache* r, struct rrset_ref* ref,
struct alloc_cache* alloc, time_t timenow);
/**
* Lookup rrset. You obtain read/write lock. You must unlock before lookup
* anything of else.
* @param r: the rrset cache.
* @param qname: name of rrset to lookup.
* @param qnamelen: length of name of rrset to lookup.
* @param qtype: type of rrset to lookup (host order).
* @param qclass: class of rrset to lookup (host order).
* @param flags: rrset flags, or 0.
* @param timenow: used to compare with TTL.
* @param wr: set true to get writelock.
* @return packed rrset key pointer. Remember to unlock the key.entry.lock.
* or NULL if could not be found or it was timed out.
*/
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);
/**
* Obtain readlock on a (sorted) list of rrset references.
* Checks TTLs and IDs of the rrsets and rollbacks locking if not Ok.
* @param ref: array of rrset references (key pointer and ID value).
* duplicate references are allowed and handled.
* @param count: size of array.
* @param timenow: used to compare with TTL.
* @return 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.
*/
int rrset_array_lock(struct rrset_ref* ref, size_t count, time_t timenow);
/**
* Unlock array (sorted) of rrset references.
* @param ref: array of rrset references (key pointer and ID value).
* duplicate references are allowed and handled.
* @param count: size of array.
*/
void rrset_array_unlock(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.
* @param r: the rrset cache. In this cache LRU is updated.
* @param 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.
* @param ref: array of rrset references (key pointer and ID value).
* duplicate references are allowed and handled.
* @param count: size of array.
*/
void rrset_array_unlock_touch(struct rrset_cache* r, struct regional* scratch,
struct rrset_ref* ref, size_t count);
/**
* 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).
* @param r: the rrset cache.
* @param rrset: which rrset to attempt to update. This rrset is left
* untouched. The rrset in the cache is updated in-place.
* @param now: current time.
*/
void rrset_update_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.
* @param r: the rrset cache.
* @param rrset: This rrset may change security status due to the cache.
* But its status will only improve, towards secure.
* @param now: current time.
*/
void rrset_check_sec_status(struct rrset_cache* r,
struct ub_packed_rrset_key* rrset, time_t now);
/**
* Remove an rrset from the cache, by name and type and flags
* @param r: rrset cache
* @param nm: name of rrset
* @param nmlen: length of name
* @param type: type of rrset
* @param dclass: class of rrset, host order
* @param flags: flags of rrset, host order
*/
void rrset_cache_remove(struct rrset_cache* r, uint8_t* nm, size_t nmlen,
uint16_t type, uint16_t dclass, uint32_t flags);
/** mark rrset to be deleted, set id=0 */
void rrset_markdel(void* key);
#endif /* SERVICES_CACHE_RRSET_H */