2 Unix SMB/CIFS implementation.
4 DNS server handler for update requests
6 Copyright (C) 2010 Kai Blin <kai@samba.org>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include "libcli/util/ntstatus.h"
24 #include "librpc/ndr/libndr.h"
25 #include "librpc/gen_ndr/ndr_dns.h"
26 #include "librpc/gen_ndr/ndr_dnsp.h"
28 #include "param/param.h"
29 #include "dsdb/samdb/samdb.h"
30 #include "dsdb/common/util.h"
31 #include "smbd/service_task.h"
32 #include "dns_server/dns_server.h"
33 #include "dns_server/dns_update.h"
35 static WERROR
dns_rr_to_dnsp(TALLOC_CTX
*mem_ctx
,
36 const struct dns_res_rec
*rrec
,
37 struct dnsp_DnssrvRpcRecord
*r
);
39 static WERROR
check_one_prerequisite(struct dns_server
*dns
,
41 const struct dns_name_question
*zone
,
42 const struct dns_res_rec
*pr
,
50 struct dnsp_DnssrvRpcRecord
*rec
= NULL
;
51 struct dnsp_DnssrvRpcRecord
*ans
;
54 size_t host_part_len
= 0;
59 return DNS_ERR(FORMAT_ERROR
);
62 match
= dns_name_match(zone
->name
, pr
->name
, &host_part_len
);
64 return DNS_ERR(NOTZONE
);
67 werror
= dns_name2dn(dns
, mem_ctx
, pr
->name
, &dn
);
68 W_ERROR_NOT_OK_RETURN(werror
);
70 if (pr
->rr_class
== DNS_QCLASS_ANY
) {
72 if (pr
->length
!= 0) {
73 return DNS_ERR(FORMAT_ERROR
);
77 if (pr
->rr_type
== DNS_QTYPE_ALL
) {
80 werror
= dns_lookup_records(dns
, mem_ctx
, dn
, &ans
, &acount
);
81 W_ERROR_NOT_OK_RETURN(werror
);
84 return DNS_ERR(NAME_ERROR
);
89 werror
= dns_lookup_records(dns
, mem_ctx
, dn
, &ans
, &acount
);
90 if (W_ERROR_EQUAL(werror
, DNS_ERR(NAME_ERROR
))) {
91 return DNS_ERR(NXRRSET
);
93 W_ERROR_NOT_OK_RETURN(werror
);
95 for (i
= 0; i
< acount
; i
++) {
96 if (ans
[i
].wType
== pr
->rr_type
) {
102 return DNS_ERR(NXRRSET
);
107 * RFC2136 3.2.5 doesn't actually mention the need to return
108 * OK here, but otherwise we'd always return a FORMAT_ERROR
109 * later on. This also matches Microsoft DNS behavior.
114 if (pr
->rr_class
== DNS_QCLASS_NONE
) {
115 if (pr
->length
!= 0) {
116 return DNS_ERR(FORMAT_ERROR
);
119 if (pr
->rr_type
== DNS_QTYPE_ALL
) {
122 werror
= dns_lookup_records(dns
, mem_ctx
, dn
, &ans
, &acount
);
123 if (W_ERROR_EQUAL(werror
, WERR_OK
)) {
124 return DNS_ERR(YXDOMAIN
);
129 werror
= dns_lookup_records(dns
, mem_ctx
, dn
, &ans
, &acount
);
130 if (W_ERROR_EQUAL(werror
, DNS_ERR(NAME_ERROR
))) {
136 for (i
= 0; i
< acount
; i
++) {
137 if (ans
[i
].wType
== pr
->rr_type
) {
143 return DNS_ERR(YXRRSET
);
148 * RFC2136 3.2.5 doesn't actually mention the need to return
149 * OK here, but otherwise we'd always return a FORMAT_ERROR
150 * later on. This also matches Microsoft DNS behavior.
155 if (pr
->rr_class
!= zone
->question_class
) {
156 return DNS_ERR(FORMAT_ERROR
);
159 *final_result
= false;
161 werror
= dns_lookup_records(dns
, mem_ctx
, dn
, &ans
, &acount
);
162 if (W_ERROR_EQUAL(werror
, DNS_ERR(NAME_ERROR
))) {
163 return DNS_ERR(NXRRSET
);
165 W_ERROR_NOT_OK_RETURN(werror
);
167 rec
= talloc_zero(mem_ctx
, struct dnsp_DnssrvRpcRecord
);
168 W_ERROR_HAVE_NO_MEMORY(rec
);
170 werror
= dns_rr_to_dnsp(rec
, pr
, rec
);
171 W_ERROR_NOT_OK_RETURN(werror
);
173 for (i
= 0; i
< acount
; i
++) {
174 if (dns_records_match(rec
, &ans
[i
])) {
181 return DNS_ERR(NXRRSET
);
187 static WERROR
check_prerequisites(struct dns_server
*dns
,
189 const struct dns_name_question
*zone
,
190 const struct dns_res_rec
*prereqs
, uint16_t count
)
193 WERROR final_error
= WERR_OK
;
195 for (i
= 0; i
< count
; i
++) {
199 werror
= check_one_prerequisite(dns
, mem_ctx
, zone
,
200 &prereqs
[i
], &final
);
201 if (!W_ERROR_IS_OK(werror
)) {
205 if (W_ERROR_IS_OK(final_error
)) {
206 final_error
= werror
;
211 if (!W_ERROR_IS_OK(final_error
)) {
218 static WERROR
update_prescan(const struct dns_name_question
*zone
,
219 const struct dns_res_rec
*updates
, uint16_t count
)
221 const struct dns_res_rec
*r
;
223 size_t host_part_len
;
226 for (i
= 0; i
< count
; i
++) {
228 match
= dns_name_match(zone
->name
, r
->name
, &host_part_len
);
230 return DNS_ERR(NOTZONE
);
232 if (zone
->question_class
== r
->rr_class
) {
233 if (r
->rr_type
== DNS_QTYPE_ALL
) {
234 return DNS_ERR(FORMAT_ERROR
);
236 if (r
->rr_type
== DNS_QTYPE_AXFR
) {
237 return DNS_ERR(FORMAT_ERROR
);
239 if (r
->rr_type
== DNS_QTYPE_MAILB
) {
240 return DNS_ERR(FORMAT_ERROR
);
242 if (r
->rr_type
== DNS_QTYPE_MAILA
) {
243 return DNS_ERR(FORMAT_ERROR
);
245 } else if (r
->rr_class
== DNS_QCLASS_ANY
) {
247 return DNS_ERR(FORMAT_ERROR
);
249 if (r
->length
!= 0) {
250 return DNS_ERR(FORMAT_ERROR
);
252 if (r
->rr_type
== DNS_QTYPE_AXFR
) {
253 return DNS_ERR(FORMAT_ERROR
);
255 if (r
->rr_type
== DNS_QTYPE_MAILB
) {
256 return DNS_ERR(FORMAT_ERROR
);
258 if (r
->rr_type
== DNS_QTYPE_MAILA
) {
259 return DNS_ERR(FORMAT_ERROR
);
261 } else if (r
->rr_class
== DNS_QCLASS_NONE
) {
263 return DNS_ERR(FORMAT_ERROR
);
265 if (r
->rr_type
== DNS_QTYPE_ALL
) {
266 return DNS_ERR(FORMAT_ERROR
);
268 if (r
->rr_type
== DNS_QTYPE_AXFR
) {
269 return DNS_ERR(FORMAT_ERROR
);
271 if (r
->rr_type
== DNS_QTYPE_MAILB
) {
272 return DNS_ERR(FORMAT_ERROR
);
274 if (r
->rr_type
== DNS_QTYPE_MAILA
) {
275 return DNS_ERR(FORMAT_ERROR
);
278 return DNS_ERR(FORMAT_ERROR
);
284 static WERROR
dns_rr_to_dnsp(TALLOC_CTX
*mem_ctx
,
285 const struct dns_res_rec
*rrec
,
286 struct dnsp_DnssrvRpcRecord
*r
)
289 char *txt_record_txt
;
290 char *saveptr
= NULL
;
292 if (rrec
->rr_type
== DNS_QTYPE_ALL
) {
293 return DNS_ERR(FORMAT_ERROR
);
298 r
->wType
= rrec
->rr_type
;
299 r
->dwTtlSeconds
= rrec
->ttl
;
300 r
->rank
= DNS_RANK_ZONE
;
301 /* TODO: Autogenerate this somehow */
304 /* If we get QCLASS_ANY, we're done here */
305 if (rrec
->rr_class
== DNS_QCLASS_ANY
) {
309 switch(rrec
->rr_type
) {
311 r
->data
.ipv4
= talloc_strdup(mem_ctx
, rrec
->rdata
.ipv4_record
);
312 W_ERROR_HAVE_NO_MEMORY(r
->data
.ipv4
);
315 r
->data
.ipv6
= talloc_strdup(mem_ctx
, rrec
->rdata
.ipv6_record
);
316 W_ERROR_HAVE_NO_MEMORY(r
->data
.ipv6
);
319 r
->data
.ns
= talloc_strdup(mem_ctx
, rrec
->rdata
.ns_record
);
320 W_ERROR_HAVE_NO_MEMORY(r
->data
.ns
);
322 case DNS_QTYPE_CNAME
:
323 r
->data
.cname
= talloc_strdup(mem_ctx
, rrec
->rdata
.cname_record
);
324 W_ERROR_HAVE_NO_MEMORY(r
->data
.cname
);
327 r
->data
.srv
.wPriority
= rrec
->rdata
.srv_record
.priority
;
328 r
->data
.srv
.wWeight
= rrec
->rdata
.srv_record
.weight
;
329 r
->data
.srv
.wPort
= rrec
->rdata
.srv_record
.port
;
330 r
->data
.srv
.nameTarget
= talloc_strdup(mem_ctx
,
331 rrec
->rdata
.srv_record
.target
);
332 W_ERROR_HAVE_NO_MEMORY(r
->data
.srv
.nameTarget
);
335 r
->data
.mx
.wPriority
= rrec
->rdata
.mx_record
.preference
;
336 r
->data
.mx
.nameTarget
= talloc_strdup(mem_ctx
,
337 rrec
->rdata
.mx_record
.exchange
);
338 W_ERROR_HAVE_NO_MEMORY(r
->data
.mx
.nameTarget
);
341 r
->data
.txt
.count
= 0;
342 r
->data
.txt
.str
= talloc_array(mem_ctx
, const char *,
344 W_ERROR_HAVE_NO_MEMORY(r
->data
.txt
.str
);
346 txt_record_txt
= talloc_strdup(r
->data
.txt
.str
,
347 rrec
->rdata
.txt_record
.txt
);
348 W_ERROR_HAVE_NO_MEMORY(txt_record_txt
);
350 tmp
= strtok_r(txt_record_txt
, "\"", &saveptr
);
352 if (strcmp(tmp
, " ") == 0) {
353 tmp
= strtok_r(NULL
, "\"", &saveptr
);
356 r
->data
.txt
.str
= talloc_realloc(mem_ctx
, r
->data
.txt
.str
, const char *,
357 r
->data
.txt
.count
+1);
358 r
->data
.txt
.str
[r
->data
.txt
.count
] = talloc_strdup(r
->data
.txt
.str
, tmp
);
359 W_ERROR_HAVE_NO_MEMORY(r
->data
.txt
.str
[r
->data
.txt
.count
]);
362 tmp
= strtok_r(NULL
, "\"", &saveptr
);
367 DEBUG(0, ("Got a qytpe of %d\n", rrec
->rr_type
));
368 return DNS_ERR(NOT_IMPLEMENTED
);
377 static WERROR
handle_one_update(struct dns_server
*dns
,
379 const struct dns_name_question
*zone
,
380 const struct dns_res_rec
*update
)
382 struct dnsp_DnssrvRpcRecord
*recs
= NULL
;
387 bool needs_add
= false;
389 DEBUG(2, ("Looking at record: \n"));
391 NDR_PRINT_DEBUG(dns_res_rec
, discard_const(update
));
394 switch (update
->rr_type
) {
399 case DNS_QTYPE_CNAME
:
414 DEBUG(0, ("Can't handle updates of type %u yet\n",
416 return DNS_ERR(NOT_IMPLEMENTED
);
419 werror
= dns_name2dn(dns
, mem_ctx
, update
->name
, &dn
);
420 W_ERROR_NOT_OK_RETURN(werror
);
422 werror
= dns_lookup_records(dns
, mem_ctx
, dn
, &recs
, &rcount
);
423 if (W_ERROR_EQUAL(werror
, DNS_ERR(NAME_ERROR
))) {
429 W_ERROR_NOT_OK_RETURN(werror
);
431 if (update
->rr_class
== zone
->question_class
) {
432 if (update
->rr_type
== DNS_QTYPE_CNAME
) {
434 * If there is a record in the directory
435 * that's not a CNAME, ignore update
437 for (i
= 0; i
< rcount
; i
++) {
438 if (recs
[i
].wType
!= DNS_TYPE_CNAME
) {
439 DEBUG(0, ("Skipping update\n"));
446 * There should be no entries besides one CNAME record
447 * per name, so replace everything with the new CNAME
451 recs
= talloc_realloc(mem_ctx
, recs
,
452 struct dnsp_DnssrvRpcRecord
, rcount
);
453 W_ERROR_HAVE_NO_MEMORY(recs
);
455 werror
= dns_rr_to_dnsp(recs
, update
, &recs
[0]);
456 W_ERROR_NOT_OK_RETURN(werror
);
458 werror
= dns_replace_records(dns
, mem_ctx
, dn
,
459 needs_add
, recs
, rcount
);
460 W_ERROR_NOT_OK_RETURN(werror
);
465 * If there is a CNAME record for this name,
468 for (i
= 0; i
< rcount
; i
++) {
469 if (recs
[i
].wType
== DNS_TYPE_CNAME
) {
470 DEBUG(0, ("Skipping update\n"));
475 if (update
->rr_type
== DNS_QTYPE_SOA
) {
479 * If the zone has no SOA record?? or update's
480 * serial number is smaller than existing SOA's,
483 for (i
= 0; i
< rcount
; i
++) {
484 if (recs
[i
].wType
== DNS_TYPE_SOA
) {
487 n
= update
->rdata
.soa_record
.serial
;
488 o
= recs
[i
].data
.soa
.serial
;
490 * TODO: Implement RFC 1982 comparison
494 DEBUG(0, ("Skipping update\n"));
502 DEBUG(0, ("Skipping update\n"));
506 werror
= dns_rr_to_dnsp(mem_ctx
, update
, &recs
[i
]);
507 W_ERROR_NOT_OK_RETURN(werror
);
509 for (i
++; i
< rcount
; i
++) {
510 if (recs
[i
].wType
!= DNS_TYPE_SOA
) {
514 ZERO_STRUCT(recs
[i
]);
517 werror
= dns_replace_records(dns
, mem_ctx
, dn
,
518 needs_add
, recs
, rcount
);
519 W_ERROR_NOT_OK_RETURN(werror
);
524 recs
= talloc_realloc(mem_ctx
, recs
,
525 struct dnsp_DnssrvRpcRecord
, rcount
+1);
526 W_ERROR_HAVE_NO_MEMORY(recs
);
528 werror
= dns_rr_to_dnsp(recs
, update
, &recs
[rcount
]);
529 W_ERROR_NOT_OK_RETURN(werror
);
531 for (i
= 0; i
< rcount
; i
++) {
532 if (!dns_records_match(&recs
[i
], &recs
[rcount
])) {
536 recs
[i
] = recs
[rcount
];
538 werror
= dns_replace_records(dns
, mem_ctx
, dn
,
539 needs_add
, recs
, rcount
);
540 W_ERROR_NOT_OK_RETURN(werror
);
545 werror
= dns_replace_records(dns
, mem_ctx
, dn
,
546 needs_add
, recs
, rcount
+1);
547 W_ERROR_NOT_OK_RETURN(werror
);
550 } else if (update
->rr_class
== DNS_QCLASS_ANY
) {
551 if (update
->rr_type
== DNS_QTYPE_ALL
) {
552 if (dns_name_equal(update
->name
, zone
->name
)) {
553 for (i
= 0; i
< rcount
; i
++) {
555 if (recs
[i
].wType
== DNS_TYPE_SOA
) {
559 if (recs
[i
].wType
== DNS_TYPE_NS
) {
563 ZERO_STRUCT(recs
[i
]);
567 for (i
= 0; i
< rcount
; i
++) {
568 ZERO_STRUCT(recs
[i
]);
572 } else if (dns_name_equal(update
->name
, zone
->name
)) {
574 if (update
->rr_type
== DNS_QTYPE_SOA
) {
578 if (update
->rr_type
== DNS_QTYPE_NS
) {
582 for (i
= 0; i
< rcount
; i
++) {
583 if (recs
[i
].wType
== update
->rr_type
) {
584 ZERO_STRUCT(recs
[i
]);
588 werror
= dns_replace_records(dns
, mem_ctx
, dn
,
589 needs_add
, recs
, rcount
);
590 W_ERROR_NOT_OK_RETURN(werror
);
593 } else if (update
->rr_class
== DNS_QCLASS_NONE
) {
594 struct dnsp_DnssrvRpcRecord
*del_rec
;
596 if (update
->rr_type
== DNS_QTYPE_SOA
) {
599 if (update
->rr_type
== DNS_QTYPE_NS
) {
601 struct dnsp_DnssrvRpcRecord
*ns_rec
= talloc(mem_ctx
,
602 struct dnsp_DnssrvRpcRecord
);
603 W_ERROR_HAVE_NO_MEMORY(ns_rec
);
606 werror
= dns_rr_to_dnsp(ns_rec
, update
, ns_rec
);
607 W_ERROR_NOT_OK_RETURN(werror
);
609 for (i
= 0; i
< rcount
; i
++) {
610 if (dns_records_match(ns_rec
, &recs
[i
])) {
620 del_rec
= talloc(mem_ctx
, struct dnsp_DnssrvRpcRecord
);
621 W_ERROR_HAVE_NO_MEMORY(del_rec
);
623 werror
= dns_rr_to_dnsp(del_rec
, update
, del_rec
);
624 W_ERROR_NOT_OK_RETURN(werror
);
626 for (i
= 0; i
< rcount
; i
++) {
627 if (dns_records_match(del_rec
, &recs
[i
])) {
628 ZERO_STRUCT(recs
[i
]);
632 werror
= dns_replace_records(dns
, mem_ctx
, dn
,
633 needs_add
, recs
, rcount
);
634 W_ERROR_NOT_OK_RETURN(werror
);
640 static WERROR
handle_updates(struct dns_server
*dns
,
642 const struct dns_name_question
*zone
,
643 const struct dns_res_rec
*prereqs
, uint16_t pcount
,
644 struct dns_res_rec
*updates
, uint16_t upd_count
)
646 struct ldb_dn
*zone_dn
= NULL
;
647 WERROR werror
= WERR_OK
;
650 TALLOC_CTX
*tmp_ctx
= talloc_new(mem_ctx
);
652 werror
= dns_name2dn(dns
, tmp_ctx
, zone
->name
, &zone_dn
);
653 W_ERROR_NOT_OK_RETURN(werror
);
655 ret
= ldb_transaction_start(dns
->samdb
);
656 if (ret
!= LDB_SUCCESS
) {
657 return DNS_ERR(SERVER_FAILURE
);
660 werror
= check_prerequisites(dns
, tmp_ctx
, zone
, prereqs
, pcount
);
661 W_ERROR_NOT_OK_GOTO(werror
, failed
);
663 DEBUG(0, ("update count is %u\n", upd_count
));
665 for (ri
= 0; ri
< upd_count
; ri
++) {
666 werror
= handle_one_update(dns
, tmp_ctx
, zone
,
668 W_ERROR_NOT_OK_GOTO(werror
, failed
);
671 ldb_transaction_commit(dns
->samdb
);
672 TALLOC_FREE(tmp_ctx
);
676 ldb_transaction_cancel(dns
->samdb
);
677 TALLOC_FREE(tmp_ctx
);
682 WERROR
dns_server_process_update(struct dns_server
*dns
,
684 struct dns_name_packet
*in
,
685 struct dns_res_rec
**prereqs
, uint16_t *prereq_count
,
686 struct dns_res_rec
**updates
, uint16_t *update_count
,
687 struct dns_res_rec
**additional
, uint16_t *arcount
)
689 struct dns_name_question
*zone
;
690 const struct dns_server_zone
*z
;
691 size_t host_part_len
= 0;
692 WERROR werror
= DNS_ERR(NOT_IMPLEMENTED
);
694 if (in
->qdcount
!= 1) {
695 return DNS_ERR(FORMAT_ERROR
);
698 zone
= &in
->questions
[0];
700 if (zone
->question_class
!= DNS_QCLASS_IN
&&
701 zone
->question_class
!= DNS_QCLASS_ANY
) {
702 return DNS_ERR(NOT_IMPLEMENTED
);
705 if (zone
->question_type
!= DNS_QTYPE_SOA
) {
706 return DNS_ERR(FORMAT_ERROR
);
709 DEBUG(2, ("Got a dns update request.\n"));
711 for (z
= dns
->zones
; z
!= NULL
; z
= z
->next
) {
714 match
= dns_name_match(z
->name
, zone
->name
, &host_part_len
);
721 DEBUG(0, ("We're not authorative for this zone\n"));
722 return DNS_ERR(NOTAUTH
);
725 if (host_part_len
!= 0) {
726 /* TODO: We need to delegate this one */
727 DEBUG(0, ("Would have to delegate zones.\n"));
728 return DNS_ERR(NOT_IMPLEMENTED
);
731 *prereq_count
= in
->ancount
;
732 *prereqs
= in
->answers
;
733 werror
= check_prerequisites(dns
, mem_ctx
, in
->questions
, *prereqs
,
735 W_ERROR_NOT_OK_RETURN(werror
);
737 /* TODO: Check if update is allowed, we probably want "always",
738 * key-based GSSAPI, key-based bind-style TSIG and "never" as
739 * smb.conf options. */
740 if (lpcfg_allow_dns_updates(dns
->task
->lp_ctx
) != DNS_UPDATE_ON
) {
741 DEBUG(0, ("Update not allowed.\n"));
742 return DNS_ERR(REFUSED
);
745 *update_count
= in
->nscount
;
746 *updates
= in
->nsrecs
;
747 werror
= update_prescan(in
->questions
, *updates
, *update_count
);
748 W_ERROR_NOT_OK_RETURN(werror
);
751 werror
= handle_updates(dns
, mem_ctx
, in
->questions
, *prereqs
,
752 *prereq_count
, *updates
, *update_count
);
753 W_ERROR_NOT_OK_RETURN(werror
);