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authorRiccardo Spagni <ric@spagni.net>2014-10-05 23:44:31 +0200
committerRiccardo Spagni <ric@spagni.net>2014-10-05 23:44:31 +0200
commit9ef094b356b4da7542c3cab898dac7e135b76903 (patch)
tree99b5876712b0b1551fc042fe75447b998e4b0fc1 /external/unbound/services/cache/rrset.c
parentsplit mnemonic printout over 3 lines (diff)
downloadmonero-9ef094b356b4da7542c3cab898dac7e135b76903.tar.xz
added unbound to external deps
Diffstat (limited to 'external/unbound/services/cache/rrset.c')
-rw-r--r--external/unbound/services/cache/rrset.c417
1 files changed, 417 insertions, 0 deletions
diff --git a/external/unbound/services/cache/rrset.c b/external/unbound/services/cache/rrset.c
new file mode 100644
index 000000000..5f52dbce1
--- /dev/null
+++ b/external/unbound/services/cache/rrset.c
@@ -0,0 +1,417 @@
+/*
+ * 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 "ldns/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);
+ /* 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(!(h = (hashvalue_t*)regional_alloc(scratch,
+ sizeof(hashvalue_t)*count)))
+ log_warn("rrset LRU: memory allocation failed");
+ 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);
+}