--- /dev/null
+/*
+ * validator/val_neg.c - validator aggressive negative caching functions.
+ *
+ * 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 REGENTS 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 helper functions for the validator module.
+ * The functions help with aggressive negative caching.
+ * This creates new denials of existance, and proofs for absence of types
+ * from cached NSEC records.
+ */
+#include "config.h"
+#include "validator/val_neg.h"
+#include "util/log.h"
+#include "util/data/dname.h"
+
+int val_neg_compare(const void* a, const void* b)
+{
+ struct val_neg_data* x = (struct val_neg_data*)a;
+ struct val_neg_data* y = (struct val_neg_data*)b;
+ int m;
+ if(x->dclass != y->dclass) {
+ if(x->dclass < y->dclass)
+ return -1;
+ return 1;
+ }
+ return dname_canon_lab_cmp(x->name, x->labs, y->name, y->labs, &m);
+}
+
+struct val_neg_cache* val_neg_create()
+{
+ struct val_neg_cache* neg = (struct val_neg_cache*)calloc(1,
+ sizeof(*neg));
+ if(!neg) {
+ log_err("Could not create neg cache: out of memory");
+ return NULL;
+ }
+ neg->max = 1024*1024; /* 1 M is about 5000(64bit)-10000(32) data */
+ rbtree_init(&neg->tree, &val_neg_compare);
+ lock_basic_init(&neg->lock);
+ lock_protect(&neg->lock, neg, sizeof(*neg));
+ return neg;
+}
+
+int val_neg_apply_cfg(struct val_neg_cache* neg, struct config_file* cfg)
+{
+ /* TODO read max mem size from cfg */
+ return 1;
+}
+
+size_t val_neg_get_mem(struct val_neg_cache* neg)
+{
+ size_t result;
+ lock_basic_lock(&neg->lock);
+ result = sizeof(*neg) + neg->use;
+ lock_basic_unlock(&neg->lock);
+ return result;
+}
+
+void neg_cache_delete(struct val_neg_cache* neg)
+{
+ struct val_neg_data* p, *np;
+ if(!neg) return;
+ lock_basic_destroy(&neg->lock);
+ /* delete all the elements */
+ p = neg->first;
+ while(p) {
+ np = p->next;
+ free(p->name);
+ free(p);
+ p = np;
+ }
+ free(neg);
+}
+
+void val_neg_addreply(struct val_neg_cache* neg, struct reply_info* rep)
+{
+ size_t i;
+ for(i=rep->an_numrrsets; i< rep->an_numrrsets+rep->ns_numrrsets; i++){
+ if(ntohs(rep->rrsets[i]->rk.type) != LDNS_RR_TYPE_NSEC)
+ continue;
+ /* insert the NSEC */
+ }
+}
+
+int val_neg_dlvlookup(struct val_neg_cache* neg, uint8_t* qname, size_t len,
+ uint16_t qclass)
+{
+ /* lookup closest data record */
+
+ /* examine proof */
+
+ /* delete closest data record if expired */
+
+ /* if OK touch the LRU for it */
+}
--- /dev/null
+/*
+ * validator/val_neg.h - validator aggressive negative caching functions.
+ *
+ * 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 REGENTS 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 helper functions for the validator module.
+ * The functions help with aggressive negative caching.
+ * This creates new denials of existance, and proofs for absence of types
+ * from cached NSEC records.
+ */
+
+#ifndef VALIDATOR_VAL_NEG_H
+#define VALIDATOR_VAL_NEG_H
+#include "util/locks.h"
+#include "util/rbtree.h"
+#include "util/data/msgreply.h"
+struct val_neg_data;
+struct config_file;
+struct reply_info;
+
+/**
+ * The negative cache. It is shared between the threads, so locked.
+ * Kept as validator-module-state. It refers back to the rrset cache for
+ * data elements. It can be out of date and contain conflicting data
+ * from zone content changes.
+ */
+struct val_neg_cache {
+ /** the big lock on the negative cache
+ * Because we use a rbtree for the data (quick lookup), we need
+ * a big lock */
+ lock_basic_t lock;
+ /** The data rbtree for NSEC. contents of type val_neg_data */
+ rbtree_t tree;
+ /** the first and last in linked list of LRU of val_neg_data */
+ struct val_neg_data* first;
+ /** last in lru (least recently used element) */
+ struct val_neg_data* last;
+ /** current memory in use (bytes) */
+ size_t use;
+ /** max memory to use (bytes) */
+ size_t max;
+};
+
+/**
+ * Data element for aggressive negative caching.
+ */
+struct val_neg_data {
+ /** rbtree node element, key is this struct: the name */
+ rbnode_t node;
+ /** name; the key */
+ uint8_t* name;
+ /** length of name */
+ size_t len;
+ /** labels in name */
+ int labs;
+
+ /** pointer to parent node in the negative cache */
+ struct val_neg_data* parent;
+
+ /** previous in LRU */
+ struct val_neg_data* prev;
+ /** next in LRU (next element was less recently used) */
+ struct val_neg_data* next;
+
+ /* reference to NSEC rrset (parent side of a zone cut) */
+ struct rrset_ref nsec_above;
+ /* reference to SOA record for zone of nsec_above */
+ struct rrset_ref soa_above;
+ /* reference to NSEC rrset (child side of a zone cut - or elsewhere) */
+ struct rrset_ref nsec_below;
+ /* reference to SOA record for zone of nsec_below */
+ struct rrset_ref soa_below;
+
+ /** class of node; host order */
+ uint16_t dclass;
+};
+
+/**
+ * Create negative cache
+ * @return neg cache, empty or NULL on failure.
+ */
+struct val_neg_cache* val_neg_create();
+
+/**
+ * Apply configuration settings to negative cache
+ * @param neg: negative cache.
+ * @param cfg: config options.
+ * @return false on error.
+ */
+int val_neg_apply_cfg(struct val_neg_cache* neg, struct config_file* cfg);
+
+/**
+ * see how much memory is in use by the negative cache.
+ * @param neg: negative cache
+ * @return number of bytes in use.
+ */
+size_t val_neg_get_mem(struct val_neg_cache* neg);
+
+/**
+ * Destroy negative cache. There must no longer be any other threads.
+ * @param neg: negative cache.
+ */
+void neg_cache_delete(struct val_neg_cache* neg);
+
+/**
+ * Comparison function for rbtree val neg data elements
+ */
+int val_neg_compare(const void* a, const void* b);
+
+/**
+ * Insert NSECs from this message into the negative cache for reference.
+ * @param neg: negative cache
+ * @param rep: reply with NSECs.
+ * Errors are ignored, means that storage is omitted.
+ */
+void val_neg_addreply(struct val_neg_cache* neg, struct reply_info* rep);
+
+/**
+ * Perform a DLV style lookup
+ * During the lookup, we could find out that data has expired. In that
+ * case the neg_cache entries are removed, and lookup fails.
+ *
+ * @param neg: negative cache.
+ * @param qname: name to look for
+ * @param len: length of qname.
+ * @param qclass: class to look in.
+ * @return
+ * 0 on error
+ * 0 if no proof of negative
+ * 1 if indeed negative was proven
+ * thus, qname DLV qclass does not exist.
+ */
+int val_neg_dlvlookup(struct val_neg_cache* neg, uint8_t* qname, size_t len,
+ uint16_t qclass);
+
+#endif /* VALIDATOR_VAL_NEG_H */
projects / thirdparty / unbound.git / commitdiff
