1238106Sdes/* 2238106Sdes * services/cache/rrset.h - Resource record set cache. 3238106Sdes * 4238106Sdes * Copyright (c) 2007, NLnet Labs. All rights reserved. 5238106Sdes * 6238106Sdes * This software is open source. 7238106Sdes * 8238106Sdes * Redistribution and use in source and binary forms, with or without 9238106Sdes * modification, are permitted provided that the following conditions 10238106Sdes * are met: 11238106Sdes * 12238106Sdes * Redistributions of source code must retain the above copyright notice, 13238106Sdes * this list of conditions and the following disclaimer. 14238106Sdes * 15238106Sdes * Redistributions in binary form must reproduce the above copyright notice, 16238106Sdes * this list of conditions and the following disclaimer in the documentation 17238106Sdes * and/or other materials provided with the distribution. 18238106Sdes * 19238106Sdes * Neither the name of the NLNET LABS nor the names of its contributors may 20238106Sdes * be used to endorse or promote products derived from this software without 21238106Sdes * specific prior written permission. 22238106Sdes * 23238106Sdes * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24269257Sdes * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 25269257Sdes * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 26269257Sdes * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 27269257Sdes * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 28269257Sdes * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 29269257Sdes * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 30269257Sdes * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 31269257Sdes * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 32269257Sdes * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 33269257Sdes * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 34238106Sdes */ 35238106Sdes 36238106Sdes/** 37238106Sdes * \file 38238106Sdes * 39238106Sdes * This file contains the rrset cache. 40238106Sdes */ 41238106Sdes 42238106Sdes#ifndef SERVICES_CACHE_RRSET_H 43238106Sdes#define SERVICES_CACHE_RRSET_H 44238106Sdes#include "util/storage/lruhash.h" 45238106Sdes#include "util/storage/slabhash.h" 46238106Sdes#include "util/data/packed_rrset.h" 47238106Sdesstruct config_file; 48238106Sdesstruct alloc_cache; 49238106Sdesstruct rrset_ref; 50238106Sdesstruct regional; 51238106Sdes 52238106Sdes/** 53238106Sdes * The rrset cache 54238106Sdes * Thin wrapper around hashtable, like a typedef. 55238106Sdes */ 56238106Sdesstruct rrset_cache { 57238106Sdes /** uses partitioned hash table */ 58238106Sdes struct slabhash table; 59238106Sdes}; 60238106Sdes 61238106Sdes/** 62238106Sdes * Create rrset cache 63238106Sdes * @param cfg: config settings or NULL for defaults. 64238106Sdes * @param alloc: initial default rrset key allocation. 65238106Sdes * @return: NULL on error. 66238106Sdes */ 67238106Sdesstruct rrset_cache* rrset_cache_create(struct config_file* cfg, 68238106Sdes struct alloc_cache* alloc); 69238106Sdes 70238106Sdes/** 71238106Sdes * Delete rrset cache 72238106Sdes * @param r: rrset cache to delete. 73238106Sdes */ 74238106Sdesvoid rrset_cache_delete(struct rrset_cache* r); 75238106Sdes 76238106Sdes/** 77238106Sdes * Adjust settings of the cache to settings from the config file. 78238106Sdes * May purge the cache. May recreate the cache. 79238106Sdes * There may be no threading or use by other threads. 80238106Sdes * @param r: rrset cache to adjust (like realloc). 81238106Sdes * @param cfg: config settings or NULL for defaults. 82238106Sdes * @param alloc: initial default rrset key allocation. 83238106Sdes * @return 0 on error, or new rrset cache pointer on success. 84238106Sdes */ 85238106Sdesstruct rrset_cache* rrset_cache_adjust(struct rrset_cache* r, 86238106Sdes struct config_file* cfg, struct alloc_cache* alloc); 87238106Sdes 88238106Sdes/** 89238106Sdes * Touch rrset, with given pointer and id. 90238106Sdes * Caller may not hold a lock on ANY rrset, this could give deadlock. 91238106Sdes * 92238106Sdes * This routine is faster than a hashtable lookup: 93238106Sdes * o no bin_lock is acquired. 94238106Sdes * o no walk through the bin-overflow-list. 95238106Sdes * o no comparison of the entry key to find it. 96238106Sdes * 97238106Sdes * @param r: rrset cache. 98238106Sdes * @param key: rrset key. Marked recently used (if it was not deleted 99238106Sdes * before the lock is acquired, in that case nothing happens). 100238106Sdes * @param hash: hash value of the item. Please read it from the key when 101238106Sdes * you have it locked. Used to find slab from slabhash. 102238106Sdes * @param id: used to check that the item is unchanged and not deleted. 103238106Sdes */ 104238106Sdesvoid rrset_cache_touch(struct rrset_cache* r, struct ub_packed_rrset_key* key, 105238106Sdes hashvalue_t hash, rrset_id_t id); 106238106Sdes 107238106Sdes/** 108238106Sdes * Update an rrset in the rrset cache. Stores the information for later use. 109238106Sdes * Will lookup if the rrset is in the cache and perform an update if necessary. 110238106Sdes * If the item was present, and superior, references are returned to that. 111238106Sdes * The passed item is then deallocated with rrset_parsedelete. 112238106Sdes * 113238106Sdes * A superior rrset is: 114238106Sdes * o rrset with better trust value. 115238106Sdes * o same trust value, different rdata, newly passed rrset is inserted. 116238106Sdes * If rdata is the same, TTL in the cache is updated. 117238106Sdes * 118238106Sdes * @param r: the rrset cache. 119238106Sdes * @param ref: reference (ptr and id) to the rrset. Pass reference setup for 120238106Sdes * the new rrset. The reference may be changed if the cached rrset is 121238106Sdes * superior. 122238106Sdes * Before calling the rrset is presumed newly allocated and changeable. 123238106Sdes * Afer calling you do not hold a lock, and the rrset is inserted in 124238106Sdes * the hashtable so you need a lock to change it. 125238106Sdes * @param alloc: how to allocate (and deallocate) the special rrset key. 126238106Sdes * @param timenow: current time (to see if ttl in cache is expired). 127238106Sdes * @return: true if the passed reference is updated, false if it is unchanged. 128238106Sdes * 0: reference unchanged, inserted in cache. 129238106Sdes * 1: reference updated, item is inserted in cache. 130238106Sdes * 2: reference updated, item in cache is considered superior. 131238106Sdes * also the rdata is equal (but other parameters in cache are superior). 132238106Sdes */ 133238106Sdesint rrset_cache_update(struct rrset_cache* r, struct rrset_ref* ref, 134269257Sdes struct alloc_cache* alloc, time_t timenow); 135238106Sdes 136238106Sdes/** 137238106Sdes * Lookup rrset. You obtain read/write lock. You must unlock before lookup 138238106Sdes * anything of else. 139238106Sdes * @param r: the rrset cache. 140238106Sdes * @param qname: name of rrset to lookup. 141238106Sdes * @param qnamelen: length of name of rrset to lookup. 142238106Sdes * @param qtype: type of rrset to lookup (host order). 143238106Sdes * @param qclass: class of rrset to lookup (host order). 144238106Sdes * @param flags: rrset flags, or 0. 145238106Sdes * @param timenow: used to compare with TTL. 146238106Sdes * @param wr: set true to get writelock. 147238106Sdes * @return packed rrset key pointer. Remember to unlock the key.entry.lock. 148238106Sdes * or NULL if could not be found or it was timed out. 149238106Sdes */ 150238106Sdesstruct ub_packed_rrset_key* rrset_cache_lookup(struct rrset_cache* r, 151238106Sdes uint8_t* qname, size_t qnamelen, uint16_t qtype, uint16_t qclass, 152269257Sdes uint32_t flags, time_t timenow, int wr); 153238106Sdes 154238106Sdes/** 155238106Sdes * Obtain readlock on a (sorted) list of rrset references. 156238106Sdes * Checks TTLs and IDs of the rrsets and rollbacks locking if not Ok. 157238106Sdes * @param ref: array of rrset references (key pointer and ID value). 158238106Sdes * duplicate references are allowed and handled. 159238106Sdes * @param count: size of array. 160238106Sdes * @param timenow: used to compare with TTL. 161238106Sdes * @return true on success, false on a failure, which can be that some 162238106Sdes * RRsets have timed out, or that they do not exist any more, the 163238106Sdes * RRsets have been purged from the cache. 164238106Sdes * If true, you hold readlocks on all the ref items. 165238106Sdes */ 166269257Sdesint rrset_array_lock(struct rrset_ref* ref, size_t count, time_t timenow); 167238106Sdes 168238106Sdes/** 169238106Sdes * Unlock array (sorted) of rrset references. 170238106Sdes * @param ref: array of rrset references (key pointer and ID value). 171238106Sdes * duplicate references are allowed and handled. 172238106Sdes * @param count: size of array. 173238106Sdes */ 174238106Sdesvoid rrset_array_unlock(struct rrset_ref* ref, size_t count); 175238106Sdes 176238106Sdes/** 177238106Sdes * Unlock array (sorted) of rrset references and at the same time 178238106Sdes * touch LRU on the rrsets. It needs the scratch region for temporary 179238106Sdes * storage as it uses the initial locks to obtain hash values. 180238106Sdes * @param r: the rrset cache. In this cache LRU is updated. 181238106Sdes * @param scratch: region for temporary storage of hash values. 182238106Sdes * if memory allocation fails, the lru touch fails silently, 183238106Sdes * but locks are released. memory errors are logged. 184238106Sdes * @param ref: array of rrset references (key pointer and ID value). 185238106Sdes * duplicate references are allowed and handled. 186238106Sdes * @param count: size of array. 187238106Sdes */ 188238106Sdesvoid rrset_array_unlock_touch(struct rrset_cache* r, struct regional* scratch, 189238106Sdes struct rrset_ref* ref, size_t count); 190238106Sdes 191238106Sdes/** 192238106Sdes * Update security status of an rrset. Looks up the rrset. 193238106Sdes * If found, checks if rdata is equal. 194238106Sdes * If so, it will update the security, trust and rrset-ttl values. 195238106Sdes * The values are only updated if security is increased (towards secure). 196238106Sdes * @param r: the rrset cache. 197238106Sdes * @param rrset: which rrset to attempt to update. This rrset is left 198238106Sdes * untouched. The rrset in the cache is updated in-place. 199238106Sdes * @param now: current time. 200238106Sdes */ 201238106Sdesvoid rrset_update_sec_status(struct rrset_cache* r, 202269257Sdes struct ub_packed_rrset_key* rrset, time_t now); 203238106Sdes 204238106Sdes/** 205238106Sdes * Looks up security status of an rrset. Looks up the rrset. 206238106Sdes * If found, checks if rdata is equal, and entry did not expire. 207238106Sdes * If so, it will update the security, trust and rrset-ttl values. 208238106Sdes * @param r: the rrset cache. 209238106Sdes * @param rrset: This rrset may change security status due to the cache. 210238106Sdes * But its status will only improve, towards secure. 211238106Sdes * @param now: current time. 212238106Sdes */ 213238106Sdesvoid rrset_check_sec_status(struct rrset_cache* r, 214269257Sdes struct ub_packed_rrset_key* rrset, time_t now); 215238106Sdes 216238106Sdes/** 217238106Sdes * Remove an rrset from the cache, by name and type and flags 218238106Sdes * @param r: rrset cache 219238106Sdes * @param nm: name of rrset 220238106Sdes * @param nmlen: length of name 221238106Sdes * @param type: type of rrset 222238106Sdes * @param dclass: class of rrset, host order 223238106Sdes * @param flags: flags of rrset, host order 224238106Sdes */ 225238106Sdesvoid rrset_cache_remove(struct rrset_cache* r, uint8_t* nm, size_t nmlen, 226238106Sdes uint16_t type, uint16_t dclass, uint32_t flags); 227238106Sdes 228238106Sdes/** mark rrset to be deleted, set id=0 */ 229238106Sdesvoid rrset_markdel(void* key); 230238106Sdes 231238106Sdes#endif /* SERVICES_CACHE_RRSET_H */ 232