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/*
* axfr.c -- generating AXFR responses.
*
* Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
*
* See LICENSE for the license.
*
*/
#include <config.h>
#include "axfr.h"
#include "dns.h"
#include "packet.h"
#include "options.h"
#define AXFR_TSIG_SIGN_EVERY_NTH 96 /* tsig sign every N packets. */
query_state_type
query_axfr(struct nsd *nsd, struct query *query)
{
domain_type *closest_match;
domain_type *closest_encloser;
int exact;
int added;
uint16_t total_added = 0;
if (query->axfr_is_done)
return QUERY_PROCESSED;
if (query->maxlen > AXFR_MAX_MESSAGE_LEN)
query->maxlen = AXFR_MAX_MESSAGE_LEN;
assert(!query_overflow(query));
#ifdef TSIG
/* only keep running values for most packets */
query->tsig_prepare_it = 0;
query->tsig_update_it = 1;
if(query->tsig_sign_it) {
/* prepare for next updates */
query->tsig_prepare_it = 1;
query->tsig_sign_it = 0;
}
#endif /* TSIG */
if (query->axfr_zone == NULL) {
/* Start AXFR. */
exact = namedb_lookup(nsd->db,
query->qname,
&closest_match,
&closest_encloser);
query->domain = closest_encloser;
query->axfr_zone = domain_find_zone(closest_encloser);
if (!exact
|| query->axfr_zone == NULL
|| query->axfr_zone->apex != query->domain)
{
/* No SOA no transfer */
RCODE_SET(query->packet, RCODE_REFUSE);
return QUERY_PROCESSED;
}
query->axfr_current_domain
= (domain_type *) rbtree_first(nsd->db->domains->names_to_domains);
query->axfr_current_rrset = NULL;
query->axfr_current_rr = 0;
#ifdef TSIG
if(query->tsig.status == TSIG_OK) {
query->tsig_sign_it = 1; /* sign first packet in stream */
}
#endif /* TSIG */
query_add_compression_domain(query, query->domain, QHEADERSZ);
assert(query->axfr_zone->soa_rrset->rr_count == 1);
added = packet_encode_rr(query,
query->axfr_zone->apex,
&query->axfr_zone->soa_rrset->rrs[0]);
if (!added) {
/* XXX: This should never happen... generate error code? */
abort();
}
++total_added;
} else {
/*
* Query name and EDNS need not be repeated after the
* first response packet.
*/
query->edns.status = EDNS_NOT_PRESENT;
buffer_set_limit(query->packet, QHEADERSZ);
QDCOUNT_SET(query->packet, 0);
query_prepare_response(query);
}
/* Add zone RRs until answer is full. */
assert(query->axfr_current_domain);
while ((rbnode_t *) query->axfr_current_domain != RBTREE_NULL) {
if (!query->axfr_current_rrset) {
query->axfr_current_rrset = domain_find_any_rrset(
query->axfr_current_domain,
query->axfr_zone);
query->axfr_current_rr = 0;
}
while (query->axfr_current_rrset) {
if (query->axfr_current_rrset != query->axfr_zone->soa_rrset
&& query->axfr_current_rrset->zone == query->axfr_zone)
{
while (query->axfr_current_rr < query->axfr_current_rrset->rr_count) {
added = packet_encode_rr(
query,
query->axfr_current_domain,
&query->axfr_current_rrset->rrs[query->axfr_current_rr]);
if (!added)
goto return_answer;
++total_added;
++query->axfr_current_rr;
}
}
query->axfr_current_rrset = query->axfr_current_rrset->next;
query->axfr_current_rr = 0;
}
assert(query->axfr_current_domain);
query->axfr_current_domain
= (domain_type *) rbtree_next((rbnode_t *) query->axfr_current_domain);
}
/* Add terminating SOA RR. */
assert(query->axfr_zone->soa_rrset->rr_count == 1);
added = packet_encode_rr(query,
query->axfr_zone->apex,
&query->axfr_zone->soa_rrset->rrs[0]);
if (added) {
++total_added;
#ifdef TSIG
query->tsig_sign_it = 1; /* sign last packet */
#endif /* TSIG */
query->axfr_is_done = 1;
}
return_answer:
ANCOUNT_SET(query->packet, total_added);
NSCOUNT_SET(query->packet, 0);
ARCOUNT_SET(query->packet, 0);
#ifdef TSIG
/* check if it needs tsig signatures */
if(query->tsig.status == TSIG_OK) {
if(query->tsig.updates_since_last_prepare >= AXFR_TSIG_SIGN_EVERY_NTH) {
query->tsig_sign_it = 1;
}
}
#endif /* TSIG */
query_clear_compression_tables(query);
return QUERY_IN_AXFR;
}
/*
* Answer if this is an AXFR or IXFR query.
*/
query_state_type
answer_axfr_ixfr(struct nsd *nsd, struct query *q)
{
acl_options_t *acl;
/* Is it AXFR? */
switch (q->qtype) {
case TYPE_AXFR:
if (q->tcp) {
zone_options_t* zone_opt;
zone_opt = zone_options_find(nsd->options, q->qname);
if(!zone_opt ||
acl_check_incoming(zone_opt->provide_xfr, q, &acl)==-1)
{
char address[128];
if (addr2ip(q->addr, address, 128)) {
DEBUG(DEBUG_XFRD,1, (LOG_INFO,
"addr2ip failed"));
strlcpy(address, "[unknown]", sizeof(address));
}
VERBOSITY(1, (LOG_INFO, "axfr for zone %s from client %s refused, %s", dname_to_string(q->qname, NULL), address, acl?"blocked":"no acl matches"));
DEBUG(DEBUG_XFRD,1, (LOG_INFO, "axfr refused, %s",
acl?"blocked":"no acl matches"));
RCODE_SET(q->packet, RCODE_REFUSE);
return QUERY_PROCESSED;
}
DEBUG(DEBUG_XFRD,1, (LOG_INFO, "axfr admitted acl %s %s",
acl->ip_address_spec, acl->key_name?acl->key_name:"NOKEY"));
return query_axfr(nsd, q);
}
case TYPE_IXFR:
RCODE_SET(q->packet, RCODE_IMPL);
return QUERY_PROCESSED;
default:
return QUERY_DISCARDED;
}
}
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