297 lines
8.4 KiB
C
297 lines
8.4 KiB
C
/*
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* iterator/iter_priv.c - iterative resolver private address and domain store
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*
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* Copyright (c) 2008, NLnet Labs. All rights reserved.
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*
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* This software is open source.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of the NLNET LABS nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file
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*
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* This file contains functions to assist the iterator module.
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* Keep track of the private addresses and lookup fast.
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*/
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#include "config.h"
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#include "iterator/iter_priv.h"
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#include "util/regional.h"
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#include "util/log.h"
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#include "util/config_file.h"
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#include "util/data/dname.h"
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#include "util/data/msgparse.h"
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#include "util/net_help.h"
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#include "util/storage/dnstree.h"
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#include "sldns/str2wire.h"
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#include "sldns/sbuffer.h"
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struct iter_priv* priv_create(void)
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{
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struct iter_priv* priv = (struct iter_priv*)calloc(1, sizeof(*priv));
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if(!priv)
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return NULL;
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priv->region = regional_create();
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if(!priv->region) {
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priv_delete(priv);
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return NULL;
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}
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addr_tree_init(&priv->a);
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name_tree_init(&priv->n);
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return priv;
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}
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void priv_delete(struct iter_priv* priv)
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{
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if(!priv) return;
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regional_destroy(priv->region);
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free(priv);
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}
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/** Read private-addr declarations from config */
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static int read_addrs(struct iter_priv* priv, struct config_file* cfg)
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{
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/* parse addresses, report errors, insert into tree */
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struct config_strlist* p;
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struct addr_tree_node* n;
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struct sockaddr_storage addr;
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int net;
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socklen_t addrlen;
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for(p = cfg->private_address; p; p = p->next) {
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log_assert(p->str);
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if(!netblockstrtoaddr(p->str, UNBOUND_DNS_PORT, &addr,
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&addrlen, &net)) {
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log_err("cannot parse private-address: %s", p->str);
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return 0;
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}
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n = (struct addr_tree_node*)regional_alloc(priv->region,
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sizeof(*n));
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if(!n) {
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log_err("out of memory");
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return 0;
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}
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if(!addr_tree_insert(&priv->a, n, &addr, addrlen, net)) {
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verbose(VERB_QUERY, "ignoring duplicate "
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"private-address: %s", p->str);
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}
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}
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return 1;
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}
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/** Read private-domain declarations from config */
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static int read_names(struct iter_priv* priv, struct config_file* cfg)
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{
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/* parse names, report errors, insert into tree */
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struct config_strlist* p;
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struct name_tree_node* n;
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uint8_t* nm, *nmr;
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size_t nm_len;
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int nm_labs;
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for(p = cfg->private_domain; p; p = p->next) {
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log_assert(p->str);
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nm = sldns_str2wire_dname(p->str, &nm_len);
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if(!nm) {
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log_err("cannot parse private-domain: %s", p->str);
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return 0;
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}
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nm_labs = dname_count_size_labels(nm, &nm_len);
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nmr = (uint8_t*)regional_alloc_init(priv->region, nm, nm_len);
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free(nm);
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if(!nmr) {
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log_err("out of memory");
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return 0;
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}
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n = (struct name_tree_node*)regional_alloc(priv->region,
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sizeof(*n));
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if(!n) {
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log_err("out of memory");
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return 0;
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}
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if(!name_tree_insert(&priv->n, n, nmr, nm_len, nm_labs,
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LDNS_RR_CLASS_IN)) {
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verbose(VERB_QUERY, "ignoring duplicate "
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"private-domain: %s", p->str);
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}
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}
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return 1;
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}
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int priv_apply_cfg(struct iter_priv* priv, struct config_file* cfg)
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{
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/* empty the current contents */
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regional_free_all(priv->region);
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addr_tree_init(&priv->a);
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name_tree_init(&priv->n);
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/* read new contents */
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if(!read_addrs(priv, cfg))
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return 0;
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if(!read_names(priv, cfg))
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return 0;
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/* prepare for lookups */
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addr_tree_init_parents(&priv->a);
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name_tree_init_parents(&priv->n);
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return 1;
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}
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/**
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* See if an address is blocked.
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* @param priv: structure for address storage.
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* @param addr: address to check
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* @param addrlen: length of addr.
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* @return: true if the address must not be queried. false if unlisted.
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*/
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static int
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priv_lookup_addr(struct iter_priv* priv, struct sockaddr_storage* addr,
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socklen_t addrlen)
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{
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return addr_tree_lookup(&priv->a, addr, addrlen) != NULL;
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}
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/**
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* See if a name is whitelisted.
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* @param priv: structure for address storage.
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* @param pkt: the packet (for compression ptrs).
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* @param name: name to check.
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* @param name_len: uncompressed length of the name to check.
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* @param dclass: class to check.
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* @return: true if the name is OK. false if unlisted.
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*/
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static int
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priv_lookup_name(struct iter_priv* priv, sldns_buffer* pkt,
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uint8_t* name, size_t name_len, uint16_t dclass)
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{
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size_t len;
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uint8_t decomp[256];
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int labs;
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if(name_len >= sizeof(decomp))
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return 0;
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dname_pkt_copy(pkt, decomp, name);
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labs = dname_count_size_labels(decomp, &len);
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log_assert(name_len == len);
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return name_tree_lookup(&priv->n, decomp, len, labs, dclass) != NULL;
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}
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size_t priv_get_mem(struct iter_priv* priv)
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{
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if(!priv) return 0;
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return sizeof(*priv) + regional_get_mem(priv->region);
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}
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/** remove RR from msgparse RRset, return true if rrset is entirely bad */
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static int
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remove_rr(const char* str, sldns_buffer* pkt, struct rrset_parse* rrset,
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struct rr_parse* prev, struct rr_parse** rr, struct sockaddr_storage* addr, socklen_t addrlen)
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{
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if(verbosity >= VERB_QUERY && rrset->dname_len <= LDNS_MAX_DOMAINLEN && str) {
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uint8_t buf[LDNS_MAX_DOMAINLEN+1];
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dname_pkt_copy(pkt, buf, rrset->dname);
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log_name_addr(VERB_QUERY, str, buf, addr, addrlen);
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}
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if(prev)
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prev->next = (*rr)->next;
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else rrset->rr_first = (*rr)->next;
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if(rrset->rr_last == *rr)
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rrset->rr_last = prev;
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rrset->rr_count --;
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rrset->size -= (*rr)->size;
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/* rr struct still exists, but is unlinked, so that in the for loop
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* the rr->next works fine to continue. */
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return rrset->rr_count == 0;
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}
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int priv_rrset_bad(struct iter_priv* priv, sldns_buffer* pkt,
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struct rrset_parse* rrset)
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{
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if(priv->a.count == 0)
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return 0; /* there are no blocked addresses */
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/* see if it is a private name, that is allowed to have any */
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if(priv_lookup_name(priv, pkt, rrset->dname, rrset->dname_len,
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ntohs(rrset->rrset_class))) {
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return 0;
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} else {
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/* so its a public name, check the address */
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socklen_t len;
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struct rr_parse* rr, *prev = NULL;
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if(rrset->type == LDNS_RR_TYPE_A) {
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struct sockaddr_storage addr;
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struct sockaddr_in sa;
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len = (socklen_t)sizeof(sa);
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memset(&sa, 0, len);
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sa.sin_family = AF_INET;
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sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT);
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for(rr = rrset->rr_first; rr; rr = rr->next) {
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if(sldns_read_uint16(rr->ttl_data+4)
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!= INET_SIZE) {
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prev = rr;
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continue;
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}
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memmove(&sa.sin_addr, rr->ttl_data+4+2,
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INET_SIZE);
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memmove(&addr, &sa, len);
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if(priv_lookup_addr(priv, &addr, len)) {
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if(remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, &rr, &addr, len))
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return 1;
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continue;
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}
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prev = rr;
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}
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} else if(rrset->type == LDNS_RR_TYPE_AAAA) {
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struct sockaddr_storage addr;
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struct sockaddr_in6 sa;
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len = (socklen_t)sizeof(sa);
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memset(&sa, 0, len);
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sa.sin6_family = AF_INET6;
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sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT);
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for(rr = rrset->rr_first; rr; rr = rr->next) {
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if(sldns_read_uint16(rr->ttl_data+4)
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!= INET6_SIZE) {
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prev = rr;
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continue;
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}
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memmove(&sa.sin6_addr, rr->ttl_data+4+2,
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INET6_SIZE);
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memmove(&addr, &sa, len);
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if(priv_lookup_addr(priv, &addr, len)) {
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if(remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, &rr, &addr, len))
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return 1;
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continue;
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}
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prev = rr;
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}
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}
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}
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return 0;
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}
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