/*
* util/storage/dnstree.c - support for rbtree types suitable for DNS code.
*
* Copyright (c) 2008, 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 structures combining types and functions to
* manipulate those structures that help building DNS lookup trees.
*/
#include "config.h"
#include "util/storage/dnstree.h"
#include "util/data/dname.h"
#include "util/net_help.h"
int name_tree_compare(const void* k1, const void* k2)
{
struct name_tree_node* x = (struct name_tree_node*)k1;
struct name_tree_node* y = (struct name_tree_node*)k2;
int m;
if(x->dclass != y->dclass) {
if(x->dclass < y->dclass)
return -1;
return 1;
}
return dname_lab_cmp(x->name, x->labs, y->name, y->labs, &m);
}
int addr_tree_compare(const void* k1, const void* k2)
{
struct addr_tree_node* n1 = (struct addr_tree_node*)k1;
struct addr_tree_node* n2 = (struct addr_tree_node*)k2;
int r = sockaddr_cmp_addr(&n1->addr, n1->addrlen, &n2->addr,
n2->addrlen);
if(r != 0) return r;
if(n1->net < n2->net)
return -1;
if(n1->net > n2->net)
return 1;
return 0;
}
void name_tree_init(rbtree_type* tree)
{
rbtree_init(tree, &name_tree_compare);
}
void addr_tree_init(rbtree_type* tree)
{
rbtree_init(tree, &addr_tree_compare);
}
int name_tree_insert(rbtree_type* tree, struct name_tree_node* node,
uint8_t* name, size_t len, int labs, uint16_t dclass)
{
node->node.key = node;
node->name = name;
node->len = len;
node->labs = labs;
node->dclass = dclass;
node->parent = NULL;
return rbtree_insert(tree, &node->node) != NULL;
}
int addr_tree_insert(rbtree_type* tree, struct addr_tree_node* node,
struct sockaddr_storage* addr, socklen_t addrlen, int net)
{
node->node.key = node;
memcpy(&node->addr, addr, addrlen);
node->addrlen = addrlen;
node->net = net;
node->parent = NULL;
return rbtree_insert(tree, &node->node) != NULL;
}
void addr_tree_init_parents_node(struct addr_tree_node* node)
{
struct addr_tree_node* prev = NULL, *p;
int m;
for(; (rbnode_type*)node != RBTREE_NULL;
node = (struct addr_tree_node*)rbtree_next((rbnode_type*)node)) {
node->parent = NULL;
if(!prev || prev->addrlen != node->addrlen) {
prev = node;
continue;
}
m = addr_in_common(&prev->addr, prev->net, &node->addr,
node->net, node->addrlen);
/* sort order like: ::/0, 1::/2, 1::/4, ... 2::/2 */
/* find the previous, or parent-parent-parent */
for(p = prev; p; p = p->parent)
if(p->net <= m) {
/* ==: since prev matched m, this is closest*/
/* <: prev matches more, but is not a parent,
* this one is a (grand)parent */
node->parent = p;
break;
}
prev = node;
}
}
void addr_tree_init_parents(rbtree_type* tree)
{
addr_tree_init_parents_node(
(struct addr_tree_node*)rbtree_first(tree));
}
void name_tree_init_parents(rbtree_type* tree)
{
struct name_tree_node* node, *prev = NULL, *p;
int m;
RBTREE_FOR(node, struct name_tree_node*, tree) {
node->parent = NULL;
if(!prev || prev->dclass != node->dclass) {
prev = node;
continue;
}
(void)dname_lab_cmp(prev->name, prev->labs, node->name,
node->labs, &m); /* we know prev is smaller */
/* sort order like: . com. bla.com. zwb.com. net. */
/* find the previous, or parent-parent-parent */
for(p = prev; p; p = p->parent)
if(p->labs <= m) {
/* ==: since prev matched m, this is closest*/
/* <: prev matches more, but is not a parent,
* this one is a (grand)parent */
node->parent = p;
break;
}
prev = node;
}
}
struct name_tree_node* name_tree_find(rbtree_type* tree, uint8_t* name,
size_t len, int labs, uint16_t dclass)
{
struct name_tree_node key;
key.node.key = &key;
key.name = name;
key.len = len;
key.labs = labs;
key.dclass = dclass;
return (struct name_tree_node*)rbtree_search(tree, &key);
}
struct name_tree_node* name_tree_lookup(rbtree_type* tree, uint8_t* name,
size_t len, int labs, uint16_t dclass)
{
rbnode_type* res = NULL;
struct name_tree_node *result;
struct name_tree_node key;
key.node.key = &key;
key.name = name;
key.len = len;
key.labs = labs;
key.dclass = dclass;
if(rbtree_find_less_equal(tree, &key, &res)) {
/* exact */
result = (struct name_tree_node*)res;
} else {
/* smaller element (or no element) */
int m;
result = (struct name_tree_node*)res;
if(!result || result->dclass != dclass)
return NULL;
/* count number of labels matched */
(void)dname_lab_cmp(result->name, result->labs, key.name,
key.labs, &m);
while(result) { /* go up until qname is subdomain of stub */
if(result->labs <= m)
break;
result = result->parent;
}
}
return result;
}
struct addr_tree_node* addr_tree_lookup(rbtree_type* tree,
struct sockaddr_storage* addr, socklen_t addrlen)
{
rbnode_type* res = NULL;
struct addr_tree_node* result;
struct addr_tree_node key;
key.node.key = &key;
memcpy(&key.addr, addr, addrlen);
key.addrlen = addrlen;
key.net = (addr_is_ip6(addr, addrlen)?128:32);
if(rbtree_find_less_equal(tree, &key, &res)) {
/* exact */
return (struct addr_tree_node*)res;
} else {
/* smaller element (or no element) */
int m;
result = (struct addr_tree_node*)res;
if(!result || result->addrlen != addrlen)
return 0;
/* count number of bits matched */
m = addr_in_common(&result->addr, result->net, addr,
key.net, addrlen);
while(result) { /* go up until addr is inside netblock */
if(result->net <= m)
break;
result = result->parent;
}
}
return result;
}
struct addr_tree_node* addr_tree_find(rbtree_type* tree,
struct sockaddr_storage* addr, socklen_t addrlen, int net)
{
rbnode_type* res = NULL;
struct addr_tree_node key;
key.node.key = &key;
memcpy(&key.addr, addr, addrlen);
key.addrlen = addrlen;
key.net = net;
res = rbtree_search(tree, &key);
return (struct addr_tree_node*)res;
}
int
name_tree_next_root(rbtree_type* tree, uint16_t* dclass)
{
struct name_tree_node key;
rbnode_type* n;
struct name_tree_node* p;
if(*dclass == 0) {
/* first root item is first item in tree */
n = rbtree_first(tree);
if(n == RBTREE_NULL)
return 0;
p = (struct name_tree_node*)n;
if(dname_is_root(p->name)) {
*dclass = p->dclass;
return 1;
}
/* root not first item? search for higher items */
*dclass = p->dclass + 1;
return name_tree_next_root(tree, dclass);
}
/* find class n in tree, we may get a direct hit, or if we don't
* this is the last item of the previous class so rbtree_next() takes
* us to the next root (if any) */
key.node.key = &key;
key.name = (uint8_t*)"\000";
key.len = 1;
key.labs = 0;
key.dclass = *dclass;
n = NULL;
if(rbtree_find_less_equal(tree, &key, &n)) {
/* exact */
return 1;
} else {
/* smaller element */
if(!n || n == RBTREE_NULL)
return 0; /* nothing found */
n = rbtree_next(n);
if(n == RBTREE_NULL)
return 0; /* no higher */
p = (struct name_tree_node*)n;
if(dname_is_root(p->name)) {
*dclass = p->dclass;
return 1;
}
/* not a root node, return next higher item */
*dclass = p->dclass+1;
return name_tree_next_root(tree, dclass);
}
}