/*
* iterator/iter_priv.c - iterative resolver private address and domain store
*
* 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 functions to assist the iterator module.
* Keep track of the private addresses and lookup fast.
*/
#include "config.h"
#include "iterator/iter_priv.h"
#include "util/regional.h"
#include "util/log.h"
#include "util/config_file.h"
#include "util/data/dname.h"
#include "util/data/msgparse.h"
#include "util/net_help.h"
#include "util/storage/dnstree.h"
#include "sldns/str2wire.h"
#include "sldns/sbuffer.h"
struct iter_priv* priv_create(void)
{
struct iter_priv* priv = (struct iter_priv*)calloc(1, sizeof(*priv));
if(!priv)
return NULL;
priv->region = regional_create();
if(!priv->region) {
priv_delete(priv);
return NULL;
}
addr_tree_init(&priv->a);
name_tree_init(&priv->n);
return priv;
}
void priv_delete(struct iter_priv* priv)
{
if(!priv) return;
regional_destroy(priv->region);
free(priv);
}
/** Read private-addr declarations from config */
static int read_addrs(struct iter_priv* priv, struct config_file* cfg)
{
/* parse addresses, report errors, insert into tree */
struct config_strlist* p;
struct addr_tree_node* n;
struct sockaddr_storage addr;
int net;
socklen_t addrlen;
for(p = cfg->private_address; p; p = p->next) {
log_assert(p->str);
if(!netblockstrtoaddr(p->str, UNBOUND_DNS_PORT, &addr,
&addrlen, &net)) {
log_err("cannot parse private-address: %s", p->str);
return 0;
}
n = (struct addr_tree_node*)regional_alloc(priv->region,
sizeof(*n));
if(!n) {
log_err("out of memory");
return 0;
}
if(!addr_tree_insert(&priv->a, n, &addr, addrlen, net)) {
verbose(VERB_QUERY, "ignoring duplicate "
"private-address: %s", p->str);
}
}
return 1;
}
/** Read private-domain declarations from config */
static int read_names(struct iter_priv* priv, struct config_file* cfg)
{
/* parse names, report errors, insert into tree */
struct config_strlist* p;
struct name_tree_node* n;
uint8_t* nm, *nmr;
size_t nm_len;
int nm_labs;
for(p = cfg->private_domain; p; p = p->next) {
log_assert(p->str);
nm = sldns_str2wire_dname(p->str, &nm_len);
if(!nm) {
log_err("cannot parse private-domain: %s", p->str);
return 0;
}
nm_labs = dname_count_size_labels(nm, &nm_len);
nmr = (uint8_t*)regional_alloc_init(priv->region, nm, nm_len);
free(nm);
if(!nmr) {
log_err("out of memory");
return 0;
}
n = (struct name_tree_node*)regional_alloc(priv->region,
sizeof(*n));
if(!n) {
log_err("out of memory");
return 0;
}
if(!name_tree_insert(&priv->n, n, nmr, nm_len, nm_labs,
LDNS_RR_CLASS_IN)) {
verbose(VERB_QUERY, "ignoring duplicate "
"private-domain: %s", p->str);
}
}
return 1;
}
int priv_apply_cfg(struct iter_priv* priv, struct config_file* cfg)
{
/* empty the current contents */
regional_free_all(priv->region);
addr_tree_init(&priv->a);
name_tree_init(&priv->n);
/* read new contents */
if(!read_addrs(priv, cfg))
return 0;
if(!read_names(priv, cfg))
return 0;
/* prepare for lookups */
addr_tree_init_parents(&priv->a);
name_tree_init_parents(&priv->n);
return 1;
}
/**
* See if an address is blocked.
* @param priv: structure for address storage.
* @param addr: address to check
* @param addrlen: length of addr.
* @return: true if the address must not be queried. false if unlisted.
*/
static int
priv_lookup_addr(struct iter_priv* priv, struct sockaddr_storage* addr,
socklen_t addrlen)
{
return addr_tree_lookup(&priv->a, addr, addrlen) != NULL;
}
/**
* See if a name is whitelisted.
* @param priv: structure for address storage.
* @param pkt: the packet (for compression ptrs).
* @param name: name to check.
* @param name_len: uncompressed length of the name to check.
* @param dclass: class to check.
* @return: true if the name is OK. false if unlisted.
*/
static int
priv_lookup_name(struct iter_priv* priv, sldns_buffer* pkt,
uint8_t* name, size_t name_len, uint16_t dclass)
{
size_t len;
uint8_t decomp[256];
int labs;
if(name_len >= sizeof(decomp))
return 0;
dname_pkt_copy(pkt, decomp, name);
labs = dname_count_size_labels(decomp, &len);
log_assert(name_len == len);
return name_tree_lookup(&priv->n, decomp, len, labs, dclass) != NULL;
}
size_t priv_get_mem(struct iter_priv* priv)
{
if(!priv) return 0;
return sizeof(*priv) + regional_get_mem(priv->region);
}
/** remove RR from msgparse RRset, return true if rrset is entirely bad */
static int
remove_rr(const char* str, sldns_buffer* pkt, struct rrset_parse* rrset,
struct rr_parse* prev, struct rr_parse** rr, struct sockaddr_storage* addr, socklen_t addrlen)
{
if(verbosity >= VERB_QUERY && rrset->dname_len <= LDNS_MAX_DOMAINLEN && str) {
uint8_t buf[LDNS_MAX_DOMAINLEN+1];
dname_pkt_copy(pkt, buf, rrset->dname);
log_name_addr(VERB_QUERY, str, buf, addr, addrlen);
}
if(prev)
prev->next = (*rr)->next;
else rrset->rr_first = (*rr)->next;
if(rrset->rr_last == *rr)
rrset->rr_last = prev;
rrset->rr_count --;
rrset->size -= (*rr)->size;
/* rr struct still exists, but is unlinked, so that in the for loop
* the rr->next works fine to continue. */
return rrset->rr_count == 0;
}
int priv_rrset_bad(struct iter_priv* priv, sldns_buffer* pkt,
struct rrset_parse* rrset)
{
if(priv->a.count == 0)
return 0; /* there are no blocked addresses */
/* see if it is a private name, that is allowed to have any */
if(priv_lookup_name(priv, pkt, rrset->dname, rrset->dname_len,
ntohs(rrset->rrset_class))) {
return 0;
} else {
/* so its a public name, check the address */
socklen_t len;
struct rr_parse* rr, *prev = NULL;
if(rrset->type == LDNS_RR_TYPE_A) {
struct sockaddr_storage addr;
struct sockaddr_in sa;
len = (socklen_t)sizeof(sa);
memset(&sa, 0, len);
sa.sin_family = AF_INET;
sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT);
for(rr = rrset->rr_first; rr; rr = rr->next) {
if(sldns_read_uint16(rr->ttl_data+4)
!= INET_SIZE) {
prev = rr;
continue;
}
memmove(&sa.sin_addr, rr->ttl_data+4+2,
INET_SIZE);
memmove(&addr, &sa, len);
if(priv_lookup_addr(priv, &addr, len)) {
if(remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, &rr, &addr, len))
return 1;
continue;
}
prev = rr;
}
} else if(rrset->type == LDNS_RR_TYPE_AAAA) {
struct sockaddr_storage addr;
struct sockaddr_in6 sa;
len = (socklen_t)sizeof(sa);
memset(&sa, 0, len);
sa.sin6_family = AF_INET6;
sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT);
for(rr = rrset->rr_first; rr; rr = rr->next) {
if(sldns_read_uint16(rr->ttl_data+4)
!= INET6_SIZE) {
prev = rr;
continue;
}
memmove(&sa.sin6_addr, rr->ttl_data+4+2,
INET6_SIZE);
memmove(&addr, &sa, len);
if(priv_lookup_addr(priv, &addr, len)) {
if(remove_rr("sanitize: removing public name with private address", pkt, rrset, prev, &rr, &addr, len))
return 1;
continue;
}
prev = rr;
}
}
}
return 0;
}