1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/*
* axfr.c -- generating AXFR responses.
*
* Copyright (c) 2001-2011, 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));
/* 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;
}
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_NOTAUTH);
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;
if(query->tsig.status == TSIG_OK) {
query->tsig_sign_it = 1; /* sign first packet in stream */
}
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;
query->tsig_sign_it = 1; /* sign last packet */
query->axfr_is_done = 1;
}
return_answer:
AA_SET(query->packet);
ANCOUNT_SET(query->packet, total_added);
NSCOUNT_SET(query->packet, 0);
ARCOUNT_SET(query->packet, 0);
/* 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;
}
}
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 = NULL;
/* Is it AXFR? */
switch (q->qtype) {
case TYPE_AXFR:
if (q->tcp) {
zone_options_t* zone_opt = zone_options_find(nsd->options, q->qname);
if(!zone_opt ||
acl_check_incoming(zone_opt->provide_xfr, q, &acl)==-1)
{
if (verbosity > 0) {
char address[128];
if (addr2ip(q->addr, address, sizeof(address))) {
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"));
if (!zone_opt) {
RCODE_SET(q->packet, RCODE_NOTAUTH);
} else {
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);
}
/** Fallthrough: AXFR over UDP queries are discarded. */
case TYPE_IXFR:
RCODE_SET(q->packet, RCODE_IMPL);
return QUERY_PROCESSED;
default:
return QUERY_DISCARDED;
}
}
|
