420 lines
13 KiB
C
420 lines
13 KiB
C
/*
|
|
* services/cache/rrset.c - 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.
|
|
*/
|
|
#include "config.h"
|
|
#include "services/cache/rrset.h"
|
|
#include "sldns/rrdef.h"
|
|
#include "util/storage/slabhash.h"
|
|
#include "util/config_file.h"
|
|
#include "util/data/packed_rrset.h"
|
|
#include "util/data/msgreply.h"
|
|
#include "util/regional.h"
|
|
#include "util/alloc.h"
|
|
|
|
void
|
|
rrset_markdel(void* key)
|
|
{
|
|
struct ub_packed_rrset_key* r = (struct ub_packed_rrset_key*)key;
|
|
r->id = 0;
|
|
}
|
|
|
|
struct rrset_cache* rrset_cache_create(struct config_file* cfg,
|
|
struct alloc_cache* alloc)
|
|
{
|
|
size_t slabs = (cfg?cfg->rrset_cache_slabs:HASH_DEFAULT_SLABS);
|
|
size_t startarray = HASH_DEFAULT_STARTARRAY;
|
|
size_t maxmem = (cfg?cfg->rrset_cache_size:HASH_DEFAULT_MAXMEM);
|
|
|
|
struct rrset_cache *r = (struct rrset_cache*)slabhash_create(slabs,
|
|
startarray, maxmem, ub_rrset_sizefunc, ub_rrset_compare,
|
|
ub_rrset_key_delete, rrset_data_delete, alloc);
|
|
slabhash_setmarkdel(&r->table, &rrset_markdel);
|
|
return r;
|
|
}
|
|
|
|
void rrset_cache_delete(struct rrset_cache* r)
|
|
{
|
|
if(!r)
|
|
return;
|
|
slabhash_delete(&r->table);
|
|
/* slabhash delete also does free(r), since table is first in struct*/
|
|
}
|
|
|
|
struct rrset_cache* rrset_cache_adjust(struct rrset_cache *r,
|
|
struct config_file* cfg, struct alloc_cache* alloc)
|
|
{
|
|
if(!r || !cfg || cfg->rrset_cache_slabs != r->table.size ||
|
|
cfg->rrset_cache_size != slabhash_get_size(&r->table))
|
|
{
|
|
rrset_cache_delete(r);
|
|
r = rrset_cache_create(cfg, alloc);
|
|
}
|
|
return r;
|
|
}
|
|
|
|
void
|
|
rrset_cache_touch(struct rrset_cache* r, struct ub_packed_rrset_key* key,
|
|
hashvalue_t hash, rrset_id_t id)
|
|
{
|
|
struct lruhash* table = slabhash_gettable(&r->table, hash);
|
|
/*
|
|
* This leads to locking problems, deadlocks, if the caller is
|
|
* holding any other rrset lock.
|
|
* Because a lookup through the hashtable does:
|
|
* tablelock -> entrylock (for that entry caller holds)
|
|
* And this would do
|
|
* entrylock(already held) -> tablelock
|
|
* And if two threads do this, it results in deadlock.
|
|
* So, the caller must not hold entrylock.
|
|
*/
|
|
lock_quick_lock(&table->lock);
|
|
/* we have locked the hash table, the item can still be deleted.
|
|
* because it could already have been reclaimed, but not yet set id=0.
|
|
* This is because some lruhash routines have lazy deletion.
|
|
* so, we must acquire a lock on the item to verify the id != 0.
|
|
* also, with hash not changed, we are using the right slab.
|
|
*/
|
|
lock_rw_rdlock(&key->entry.lock);
|
|
if(key->id == id && key->entry.hash == hash) {
|
|
lru_touch(table, &key->entry);
|
|
}
|
|
lock_rw_unlock(&key->entry.lock);
|
|
lock_quick_unlock(&table->lock);
|
|
}
|
|
|
|
/** see if rrset needs to be updated in the cache */
|
|
static int
|
|
need_to_update_rrset(void* nd, void* cd, time_t timenow, int equal, int ns)
|
|
{
|
|
struct packed_rrset_data* newd = (struct packed_rrset_data*)nd;
|
|
struct packed_rrset_data* cached = (struct packed_rrset_data*)cd;
|
|
/* o store if rrset has been validated
|
|
* everything better than bogus data
|
|
* secure is preferred */
|
|
if( newd->security == sec_status_secure &&
|
|
cached->security != sec_status_secure)
|
|
return 1;
|
|
if( cached->security == sec_status_bogus &&
|
|
newd->security != sec_status_bogus && !equal)
|
|
return 1;
|
|
/* o if current RRset is more trustworthy - insert it */
|
|
if( newd->trust > cached->trust ) {
|
|
/* if the cached rrset is bogus, and this one equal,
|
|
* do not update the TTL - let it expire. */
|
|
if(equal && cached->ttl >= timenow &&
|
|
cached->security == sec_status_bogus)
|
|
return 0;
|
|
return 1;
|
|
}
|
|
/* o item in cache has expired */
|
|
if( cached->ttl < timenow )
|
|
return 1;
|
|
/* o same trust, but different in data - insert it */
|
|
if( newd->trust == cached->trust && !equal ) {
|
|
/* if this is type NS, do not 'stick' to owner that changes
|
|
* the NS RRset, but use the old TTL for the new data, and
|
|
* update to fetch the latest data. ttl is not expired, because
|
|
* that check was before this one. */
|
|
if(ns) {
|
|
size_t i;
|
|
newd->ttl = cached->ttl;
|
|
for(i=0; i<(newd->count+newd->rrsig_count); i++)
|
|
if(newd->rr_ttl[i] > newd->ttl)
|
|
newd->rr_ttl[i] = newd->ttl;
|
|
}
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/** Update RRSet special key ID */
|
|
static void
|
|
rrset_update_id(struct rrset_ref* ref, struct alloc_cache* alloc)
|
|
{
|
|
/* this may clear the cache and invalidate lock below */
|
|
uint64_t newid = alloc_get_id(alloc);
|
|
/* obtain writelock */
|
|
lock_rw_wrlock(&ref->key->entry.lock);
|
|
/* check if it was deleted in the meantime, if so, skip update */
|
|
if(ref->key->id == ref->id) {
|
|
ref->key->id = newid;
|
|
ref->id = newid;
|
|
}
|
|
lock_rw_unlock(&ref->key->entry.lock);
|
|
}
|
|
|
|
int
|
|
rrset_cache_update(struct rrset_cache* r, struct rrset_ref* ref,
|
|
struct alloc_cache* alloc, time_t timenow)
|
|
{
|
|
struct lruhash_entry* e;
|
|
struct ub_packed_rrset_key* k = ref->key;
|
|
hashvalue_t h = k->entry.hash;
|
|
uint16_t rrset_type = ntohs(k->rk.type);
|
|
int equal = 0;
|
|
log_assert(ref->id != 0 && k->id != 0);
|
|
log_assert(k->rk.dname != NULL);
|
|
/* looks up item with a readlock - no editing! */
|
|
if((e=slabhash_lookup(&r->table, h, k, 0)) != 0) {
|
|
/* return id and key as they will be used in the cache
|
|
* since the lruhash_insert, if item already exists, deallocs
|
|
* the passed key in favor of the already stored key.
|
|
* because of the small gap (see below) this key ptr and id
|
|
* may prove later to be already deleted, which is no problem
|
|
* as it only makes a cache miss.
|
|
*/
|
|
ref->key = (struct ub_packed_rrset_key*)e->key;
|
|
ref->id = ref->key->id;
|
|
equal = rrsetdata_equal((struct packed_rrset_data*)k->entry.
|
|
data, (struct packed_rrset_data*)e->data);
|
|
if(!need_to_update_rrset(k->entry.data, e->data, timenow,
|
|
equal, (rrset_type==LDNS_RR_TYPE_NS))) {
|
|
/* cache is superior, return that value */
|
|
lock_rw_unlock(&e->lock);
|
|
ub_packed_rrset_parsedelete(k, alloc);
|
|
if(equal) return 2;
|
|
return 1;
|
|
}
|
|
lock_rw_unlock(&e->lock);
|
|
/* Go on and insert the passed item.
|
|
* small gap here, where entry is not locked.
|
|
* possibly entry is updated with something else.
|
|
* we then overwrite that with our data.
|
|
* this is just too bad, its cache anyway. */
|
|
/* use insert to update entry to manage lruhash
|
|
* cache size values nicely. */
|
|
}
|
|
log_assert(ref->key->id != 0);
|
|
slabhash_insert(&r->table, h, &k->entry, k->entry.data, alloc);
|
|
if(e) {
|
|
/* For NSEC, NSEC3, DNAME, when rdata is updated, update
|
|
* the ID number so that proofs in message cache are
|
|
* invalidated */
|
|
if((rrset_type == LDNS_RR_TYPE_NSEC
|
|
|| rrset_type == LDNS_RR_TYPE_NSEC3
|
|
|| rrset_type == LDNS_RR_TYPE_DNAME) && !equal) {
|
|
rrset_update_id(ref, alloc);
|
|
}
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
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)
|
|
{
|
|
struct lruhash_entry* e;
|
|
struct ub_packed_rrset_key key;
|
|
|
|
key.entry.key = &key;
|
|
key.entry.data = NULL;
|
|
key.rk.dname = qname;
|
|
key.rk.dname_len = qnamelen;
|
|
key.rk.type = htons(qtype);
|
|
key.rk.rrset_class = htons(qclass);
|
|
key.rk.flags = flags;
|
|
|
|
key.entry.hash = rrset_key_hash(&key.rk);
|
|
|
|
if((e = slabhash_lookup(&r->table, key.entry.hash, &key, wr))) {
|
|
/* check TTL */
|
|
struct packed_rrset_data* data =
|
|
(struct packed_rrset_data*)e->data;
|
|
if(timenow > data->ttl) {
|
|
lock_rw_unlock(&e->lock);
|
|
return NULL;
|
|
}
|
|
/* we're done */
|
|
return (struct ub_packed_rrset_key*)e->key;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
int
|
|
rrset_array_lock(struct rrset_ref* ref, size_t count, time_t timenow)
|
|
{
|
|
size_t i;
|
|
for(i=0; i<count; i++) {
|
|
if(i>0 && ref[i].key == ref[i-1].key)
|
|
continue; /* only lock items once */
|
|
lock_rw_rdlock(&ref[i].key->entry.lock);
|
|
if(ref[i].id != ref[i].key->id || timenow >
|
|
((struct packed_rrset_data*)(ref[i].key->entry.data))
|
|
->ttl) {
|
|
/* failure! rollback our readlocks */
|
|
rrset_array_unlock(ref, i+1);
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
void
|
|
rrset_array_unlock(struct rrset_ref* ref, size_t count)
|
|
{
|
|
size_t i;
|
|
for(i=0; i<count; i++) {
|
|
if(i>0 && ref[i].key == ref[i-1].key)
|
|
continue; /* only unlock items once */
|
|
lock_rw_unlock(&ref[i].key->entry.lock);
|
|
}
|
|
}
|
|
|
|
void
|
|
rrset_array_unlock_touch(struct rrset_cache* r, struct regional* scratch,
|
|
struct rrset_ref* ref, size_t count)
|
|
{
|
|
hashvalue_t* h;
|
|
size_t i;
|
|
if(count > RR_COUNT_MAX || !(h = (hashvalue_t*)regional_alloc(scratch,
|
|
sizeof(hashvalue_t)*count))) {
|
|
log_warn("rrset LRU: memory allocation failed");
|
|
h = NULL;
|
|
} else /* store hash values */
|
|
for(i=0; i<count; i++)
|
|
h[i] = ref[i].key->entry.hash;
|
|
/* unlock */
|
|
for(i=0; i<count; i++) {
|
|
if(i>0 && ref[i].key == ref[i-1].key)
|
|
continue; /* only unlock items once */
|
|
lock_rw_unlock(&ref[i].key->entry.lock);
|
|
}
|
|
if(h) {
|
|
/* LRU touch, with no rrset locks held */
|
|
for(i=0; i<count; i++) {
|
|
if(i>0 && ref[i].key == ref[i-1].key)
|
|
continue; /* only touch items once */
|
|
rrset_cache_touch(r, ref[i].key, h[i], ref[i].id);
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
rrset_update_sec_status(struct rrset_cache* r,
|
|
struct ub_packed_rrset_key* rrset, time_t now)
|
|
{
|
|
struct packed_rrset_data* updata =
|
|
(struct packed_rrset_data*)rrset->entry.data;
|
|
struct lruhash_entry* e;
|
|
struct packed_rrset_data* cachedata;
|
|
|
|
/* hash it again to make sure it has a hash */
|
|
rrset->entry.hash = rrset_key_hash(&rrset->rk);
|
|
|
|
e = slabhash_lookup(&r->table, rrset->entry.hash, rrset, 1);
|
|
if(!e)
|
|
return; /* not in the cache anymore */
|
|
cachedata = (struct packed_rrset_data*)e->data;
|
|
if(!rrsetdata_equal(updata, cachedata)) {
|
|
lock_rw_unlock(&e->lock);
|
|
return; /* rrset has changed in the meantime */
|
|
}
|
|
/* update the cached rrset */
|
|
if(updata->security > cachedata->security) {
|
|
size_t i;
|
|
if(updata->trust > cachedata->trust)
|
|
cachedata->trust = updata->trust;
|
|
cachedata->security = updata->security;
|
|
/* for NS records only shorter TTLs, other types: update it */
|
|
if(ntohs(rrset->rk.type) != LDNS_RR_TYPE_NS ||
|
|
updata->ttl+now < cachedata->ttl ||
|
|
cachedata->ttl < now ||
|
|
updata->security == sec_status_bogus) {
|
|
cachedata->ttl = updata->ttl + now;
|
|
for(i=0; i<cachedata->count+cachedata->rrsig_count; i++)
|
|
cachedata->rr_ttl[i] = updata->rr_ttl[i]+now;
|
|
}
|
|
}
|
|
lock_rw_unlock(&e->lock);
|
|
}
|
|
|
|
void
|
|
rrset_check_sec_status(struct rrset_cache* r,
|
|
struct ub_packed_rrset_key* rrset, time_t now)
|
|
{
|
|
struct packed_rrset_data* updata =
|
|
(struct packed_rrset_data*)rrset->entry.data;
|
|
struct lruhash_entry* e;
|
|
struct packed_rrset_data* cachedata;
|
|
|
|
/* hash it again to make sure it has a hash */
|
|
rrset->entry.hash = rrset_key_hash(&rrset->rk);
|
|
|
|
e = slabhash_lookup(&r->table, rrset->entry.hash, rrset, 0);
|
|
if(!e)
|
|
return; /* not in the cache anymore */
|
|
cachedata = (struct packed_rrset_data*)e->data;
|
|
if(now > cachedata->ttl || !rrsetdata_equal(updata, cachedata)) {
|
|
lock_rw_unlock(&e->lock);
|
|
return; /* expired, or rrset has changed in the meantime */
|
|
}
|
|
if(cachedata->security > updata->security) {
|
|
updata->security = cachedata->security;
|
|
if(cachedata->security == sec_status_bogus) {
|
|
size_t i;
|
|
updata->ttl = cachedata->ttl - now;
|
|
for(i=0; i<cachedata->count+cachedata->rrsig_count; i++)
|
|
if(cachedata->rr_ttl[i] < now)
|
|
updata->rr_ttl[i] = 0;
|
|
else updata->rr_ttl[i] =
|
|
cachedata->rr_ttl[i]-now;
|
|
}
|
|
if(cachedata->trust > updata->trust)
|
|
updata->trust = cachedata->trust;
|
|
}
|
|
lock_rw_unlock(&e->lock);
|
|
}
|
|
|
|
void rrset_cache_remove(struct rrset_cache* r, uint8_t* nm, size_t nmlen,
|
|
uint16_t type, uint16_t dclass, uint32_t flags)
|
|
{
|
|
struct ub_packed_rrset_key key;
|
|
key.entry.key = &key;
|
|
key.rk.dname = nm;
|
|
key.rk.dname_len = nmlen;
|
|
key.rk.rrset_class = htons(dclass);
|
|
key.rk.type = htons(type);
|
|
key.rk.flags = flags;
|
|
key.entry.hash = rrset_key_hash(&key.rk);
|
|
slabhash_remove(&r->table, key.entry.hash, &key);
|
|
}
|