/*
* iterator/iter_hints.c - iterative resolver module stub and root hints.
*
* 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 functions to assist the iterator module.
* Keep track of stub and root hints, and read those from config.
*/
#include "config.h"
#include "iterator/iter_hints.h"
#include "iterator/iter_delegpt.h"
#include "util/log.h"
#include "util/config_file.h"
#include "util/net_help.h"
#include "util/data/dname.h"
#include "sldns/rrdef.h"
#include "sldns/str2wire.h"
#include "sldns/wire2str.h"
struct iter_hints*
hints_create(void)
{
struct iter_hints* hints = (struct iter_hints*)calloc(1,
sizeof(struct iter_hints));
if(!hints)
return NULL;
return hints;
}
static void hints_stub_free(struct iter_hints_stub* s)
{
if(!s) return;
delegpt_free_mlc(s->dp);
free(s);
}
static void delhintnode(rbnode_type* n, void* ATTR_UNUSED(arg))
{
struct iter_hints_stub* node = (struct iter_hints_stub*)n;
hints_stub_free(node);
}
static void hints_del_tree(struct iter_hints* hints)
{
traverse_postorder(&hints->tree, &delhintnode, NULL);
}
void
hints_delete(struct iter_hints* hints)
{
if(!hints)
return;
hints_del_tree(hints);
free(hints);
}
/** add hint to delegation hints */
static int
ah(struct delegpt* dp, const char* sv, const char* ip)
{
struct sockaddr_storage addr;
socklen_t addrlen;
size_t dname_len;
uint8_t* dname = sldns_str2wire_dname(sv, &dname_len);
if(!dname) {
log_err("could not parse %s", sv);
return 0;
}
if(!delegpt_add_ns_mlc(dp, dname, 0) ||
!extstrtoaddr(ip, &addr, &addrlen) ||
!delegpt_add_target_mlc(dp, dname, dname_len,
&addr, addrlen, 0, 0)) {
free(dname);
return 0;
}
free(dname);
return 1;
}
/** obtain compiletime provided root hints */
static struct delegpt*
compile_time_root_prime(int do_ip4, int do_ip6)
{
/* from:
; This file is made available by InterNIC
; under anonymous FTP as
; file /domain/named.cache
; on server FTP.INTERNIC.NET
; -OR- RS.INTERNIC.NET
;
; related version of root zone: changes-on-20120103
*/
struct delegpt* dp = delegpt_create_mlc((uint8_t*)"\000");
if(!dp)
return NULL;
dp->has_parent_side_NS = 1;
if(do_ip4) {
if(!ah(dp, "A.ROOT-SERVERS.NET.", "198.41.0.4")) goto failed;
if(!ah(dp, "B.ROOT-SERVERS.NET.", "192.228.79.201")) goto failed;
if(!ah(dp, "C.ROOT-SERVERS.NET.", "192.33.4.12")) goto failed;
if(!ah(dp, "D.ROOT-SERVERS.NET.", "199.7.91.13")) goto failed;
if(!ah(dp, "E.ROOT-SERVERS.NET.", "192.203.230.10")) goto failed;
if(!ah(dp, "F.ROOT-SERVERS.NET.", "192.5.5.241")) goto failed;
if(!ah(dp, "G.ROOT-SERVERS.NET.", "192.112.36.4")) goto failed;
if(!ah(dp, "H.ROOT-SERVERS.NET.", "198.97.190.53")) goto failed;
if(!ah(dp, "I.ROOT-SERVERS.NET.", "192.36.148.17")) goto failed;
if(!ah(dp, "J.ROOT-SERVERS.NET.", "192.58.128.30")) goto failed;
if(!ah(dp, "K.ROOT-SERVERS.NET.", "193.0.14.129")) goto failed;
if(!ah(dp, "L.ROOT-SERVERS.NET.", "199.7.83.42")) goto failed;
if(!ah(dp, "M.ROOT-SERVERS.NET.", "202.12.27.33")) goto failed;
}
if(do_ip6) {
if(!ah(dp, "A.ROOT-SERVERS.NET.", "2001:503:ba3e::2:30")) goto failed;
if(!ah(dp, "B.ROOT-SERVERS.NET.", "2001:500:84::b")) goto failed;
if(!ah(dp, "C.ROOT-SERVERS.NET.", "2001:500:2::c")) goto failed;
if(!ah(dp, "D.ROOT-SERVERS.NET.", "2001:500:2d::d")) goto failed;
if(!ah(dp, "E.ROOT-SERVERS.NET.", "2001:500:a8::e")) goto failed;
if(!ah(dp, "F.ROOT-SERVERS.NET.", "2001:500:2f::f")) goto failed;
if(!ah(dp, "G.ROOT-SERVERS.NET.", "2001:500:12::d0d")) goto failed;
if(!ah(dp, "H.ROOT-SERVERS.NET.", "2001:500:1::53")) goto failed;
if(!ah(dp, "I.ROOT-SERVERS.NET.", "2001:7fe::53")) goto failed;
if(!ah(dp, "J.ROOT-SERVERS.NET.", "2001:503:c27::2:30")) goto failed;
if(!ah(dp, "K.ROOT-SERVERS.NET.", "2001:7fd::1")) goto failed;
if(!ah(dp, "L.ROOT-SERVERS.NET.", "2001:500:9f::42")) goto failed;
if(!ah(dp, "M.ROOT-SERVERS.NET.", "2001:dc3::35")) goto failed;
}
return dp;
failed:
delegpt_free_mlc(dp);
return 0;
}
/** insert new hint info into hint structure */
static int
hints_insert(struct iter_hints* hints, uint16_t c, struct delegpt* dp,
int noprime)
{
struct iter_hints_stub* node = (struct iter_hints_stub*)malloc(
sizeof(struct iter_hints_stub));
if(!node) {
delegpt_free_mlc(dp);
return 0;
}
node->dp = dp;
node->noprime = (uint8_t)noprime;
if(!name_tree_insert(&hints->tree, &node->node, dp->name, dp->namelen,
dp->namelabs, c)) {
char buf[257];
dname_str(dp->name, buf);
log_err("second hints for zone %s ignored.", buf);
delegpt_free_mlc(dp);
free(node);
}
return 1;
}
/** set stub name */
static struct delegpt*
read_stubs_name(struct config_stub* s)
{
struct delegpt* dp;
size_t dname_len;
uint8_t* dname;
if(!s->name) {
log_err("stub zone without a name");
return NULL;
}
dname = sldns_str2wire_dname(s->name, &dname_len);
if(!dname) {
log_err("cannot parse stub zone name %s", s->name);
return NULL;
}
if(!(dp=delegpt_create_mlc(dname))) {
free(dname);
log_err("out of memory");
return NULL;
}
free(dname);
return dp;
}
/** set stub host names */
static int
read_stubs_host(struct config_stub* s, struct delegpt* dp)
{
struct config_strlist* p;
size_t dname_len;
uint8_t* dname;
for(p = s->hosts; p; p = p->next) {
log_assert(p->str);
dname = sldns_str2wire_dname(p->str, &dname_len);
if(!dname) {
log_err("cannot parse stub %s nameserver name: '%s'",
s->name, p->str);
return 0;
}
if(!delegpt_add_ns_mlc(dp, dname, 0)) {
free(dname);
log_err("out of memory");
return 0;
}
free(dname);
}
return 1;
}
/** set stub server addresses */
static int
read_stubs_addr(struct config_stub* s, struct delegpt* dp)
{
struct config_strlist* p;
struct sockaddr_storage addr;
socklen_t addrlen;
for(p = s->addrs; p; p = p->next) {
log_assert(p->str);
if(!extstrtoaddr(p->str, &addr, &addrlen)) {
log_err("cannot parse stub %s ip address: '%s'",
s->name, p->str);
return 0;
}
if(!delegpt_add_addr_mlc(dp, &addr, addrlen, 0, 0)) {
log_err("out of memory");
return 0;
}
}
return 1;
}
/** read stubs config */
static int
read_stubs(struct iter_hints* hints, struct config_file* cfg)
{
struct config_stub* s;
struct delegpt* dp;
for(s = cfg->stubs; s; s = s->next) {
if(!(dp=read_stubs_name(s)))
return 0;
if(!read_stubs_host(s, dp) || !read_stubs_addr(s, dp)) {
delegpt_free_mlc(dp);
return 0;
}
/* the flag is turned off for 'stub-first' so that the
* last resort will ask for parent-side NS record and thus
* fallback to the internet name servers on a failure */
dp->has_parent_side_NS = (uint8_t)!s->isfirst;
/* ssl_upstream */
dp->ssl_upstream = (uint8_t)s->ssl_upstream;
delegpt_log(VERB_QUERY, dp);
if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, !s->isprime))
return 0;
}
return 1;
}
/** read root hints from file */
static int
read_root_hints(struct iter_hints* hints, char* fname)
{
struct sldns_file_parse_state pstate;
struct delegpt* dp;
uint8_t rr[LDNS_RR_BUF_SIZE];
size_t rr_len, dname_len;
int status;
uint16_t c = LDNS_RR_CLASS_IN;
FILE* f = fopen(fname, "r");
if(!f) {
log_err("could not read root hints %s: %s",
fname, strerror(errno));
return 0;
}
dp = delegpt_create_mlc(NULL);
if(!dp) {
log_err("out of memory reading root hints");
fclose(f);
return 0;
}
verbose(VERB_QUERY, "Reading root hints from %s", fname);
memset(&pstate, 0, sizeof(pstate));
pstate.lineno = 1;
dp->has_parent_side_NS = 1;
while(!feof(f)) {
rr_len = sizeof(rr);
dname_len = 0;
status = sldns_fp2wire_rr_buf(f, rr, &rr_len, &dname_len,
&pstate);
if(status != 0) {
log_err("reading root hints %s %d:%d: %s", fname,
pstate.lineno, LDNS_WIREPARSE_OFFSET(status),
sldns_get_errorstr_parse(status));
goto stop_read;
}
if(rr_len == 0)
continue; /* EMPTY line, TTL or ORIGIN */
if(sldns_wirerr_get_type(rr, rr_len, dname_len)
== LDNS_RR_TYPE_NS) {
if(!delegpt_add_ns_mlc(dp, sldns_wirerr_get_rdata(rr,
rr_len, dname_len), 0)) {
log_err("out of memory reading root hints");
goto stop_read;
}
c = sldns_wirerr_get_class(rr, rr_len, dname_len);
if(!dp->name) {
if(!delegpt_set_name_mlc(dp, rr)) {
log_err("out of memory.");
goto stop_read;
}
}
} else if(sldns_wirerr_get_type(rr, rr_len, dname_len)
== LDNS_RR_TYPE_A && sldns_wirerr_get_rdatalen(rr,
rr_len, dname_len) == INET_SIZE) {
struct sockaddr_in sa;
socklen_t len = (socklen_t)sizeof(sa);
memset(&sa, 0, len);
sa.sin_family = AF_INET;
sa.sin_port = (in_port_t)htons(UNBOUND_DNS_PORT);
memmove(&sa.sin_addr,
sldns_wirerr_get_rdata(rr, rr_len, dname_len),
INET_SIZE);
if(!delegpt_add_target_mlc(dp, rr, dname_len,
(struct sockaddr_storage*)&sa, len,
0, 0)) {
log_err("out of memory reading root hints");
goto stop_read;
}
} else if(sldns_wirerr_get_type(rr, rr_len, dname_len)
== LDNS_RR_TYPE_AAAA && sldns_wirerr_get_rdatalen(rr,
rr_len, dname_len) == INET6_SIZE) {
struct sockaddr_in6 sa;
socklen_t len = (socklen_t)sizeof(sa);
memset(&sa, 0, len);
sa.sin6_family = AF_INET6;
sa.sin6_port = (in_port_t)htons(UNBOUND_DNS_PORT);
memmove(&sa.sin6_addr,
sldns_wirerr_get_rdata(rr, rr_len, dname_len),
INET6_SIZE);
if(!delegpt_add_target_mlc(dp, rr, dname_len,
(struct sockaddr_storage*)&sa, len,
0, 0)) {
log_err("out of memory reading root hints");
goto stop_read;
}
} else {
char buf[17];
sldns_wire2str_type_buf(sldns_wirerr_get_type(rr,
rr_len, dname_len), buf, sizeof(buf));
log_warn("root hints %s:%d skipping type %s",
fname, pstate.lineno, buf);
}
}
fclose(f);
if(!dp->name) {
log_warn("root hints %s: no NS content", fname);
delegpt_free_mlc(dp);
return 1;
}
if(!hints_insert(hints, c, dp, 0)) {
return 0;
}
delegpt_log(VERB_QUERY, dp);
return 1;
stop_read:
delegpt_free_mlc(dp);
fclose(f);
return 0;
}
/** read root hints list */
static int
read_root_hints_list(struct iter_hints* hints, struct config_file* cfg)
{
struct config_strlist* p;
for(p = cfg->root_hints; p; p = p->next) {
log_assert(p->str);
if(p->str && p->str[0]) {
char* f = p->str;
if(cfg->chrootdir && cfg->chrootdir[0] &&
strncmp(p->str, cfg->chrootdir,
strlen(cfg->chrootdir)) == 0)
f += strlen(cfg->chrootdir);
if(!read_root_hints(hints, f))
return 0;
}
}
return 1;
}
int
hints_apply_cfg(struct iter_hints* hints, struct config_file* cfg)
{
hints_del_tree(hints);
name_tree_init(&hints->tree);
/* read root hints */
if(!read_root_hints_list(hints, cfg))
return 0;
/* read stub hints */
if(!read_stubs(hints, cfg))
return 0;
/* use fallback compiletime root hints */
if(!hints_lookup_root(hints, LDNS_RR_CLASS_IN)) {
struct delegpt* dp = compile_time_root_prime(cfg->do_ip4,
cfg->do_ip6);
verbose(VERB_ALGO, "no config, using builtin root hints.");
if(!dp)
return 0;
if(!hints_insert(hints, LDNS_RR_CLASS_IN, dp, 0))
return 0;
}
name_tree_init_parents(&hints->tree);
return 1;
}
struct delegpt*
hints_lookup_root(struct iter_hints* hints, uint16_t qclass)
{
uint8_t rootlab = 0;
struct iter_hints_stub *stub;
stub = (struct iter_hints_stub*)name_tree_find(&hints->tree,
&rootlab, 1, 1, qclass);
if(!stub)
return NULL;
return stub->dp;
}
struct iter_hints_stub*
hints_lookup_stub(struct iter_hints* hints, uint8_t* qname,
uint16_t qclass, struct delegpt* cache_dp)
{
size_t len;
int labs;
struct iter_hints_stub *r;
/* first lookup the stub */
labs = dname_count_size_labels(qname, &len);
r = (struct iter_hints_stub*)name_tree_lookup(&hints->tree, qname,
len, labs, qclass);
if(!r) return NULL;
/* If there is no cache (root prime situation) */
if(cache_dp == NULL) {
if(r->dp->namelabs != 1)
return r; /* no cache dp, use any non-root stub */
return NULL;
}
/*
* If the stub is same as the delegation we got
* And has noprime set, we need to 'prime' to use this stub instead.
*/
if(r->noprime && query_dname_compare(cache_dp->name, r->dp->name)==0)
return r; /* use this stub instead of cached dp */
/*
* If our cached delegation point is above the hint, we need to prime.
*/
if(dname_strict_subdomain(r->dp->name, r->dp->namelabs,
cache_dp->name, cache_dp->namelabs))
return r; /* need to prime this stub */
return NULL;
}
int hints_next_root(struct iter_hints* hints, uint16_t* qclass)
{
return name_tree_next_root(&hints->tree, qclass);
}
size_t
hints_get_mem(struct iter_hints* hints)
{
size_t s;
struct iter_hints_stub* p;
if(!hints) return 0;
s = sizeof(*hints);
RBTREE_FOR(p, struct iter_hints_stub*, &hints->tree) {
s += sizeof(*p) + delegpt_get_mem(p->dp);
}
return s;
}
int
hints_add_stub(struct iter_hints* hints, uint16_t c, struct delegpt* dp,
int noprime)
{
struct iter_hints_stub *z;
if((z=(struct iter_hints_stub*)name_tree_find(&hints->tree,
dp->name, dp->namelen, dp->namelabs, c)) != NULL) {
(void)rbtree_delete(&hints->tree, &z->node);
hints_stub_free(z);
}
if(!hints_insert(hints, c, dp, noprime))
return 0;
name_tree_init_parents(&hints->tree);
return 1;
}
void
hints_delete_stub(struct iter_hints* hints, uint16_t c, uint8_t* nm)
{
struct iter_hints_stub *z;
size_t len;
int labs = dname_count_size_labels(nm, &len);
if(!(z=(struct iter_hints_stub*)name_tree_find(&hints->tree,
nm, len, labs, c)))
return; /* nothing to do */
(void)rbtree_delete(&hints->tree, &z->node);
hints_stub_free(z);
name_tree_init_parents(&hints->tree);
}
