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)
288 if (rrec->rr_type == DNS_QTYPE_ALL) {
289 return DNS_ERR(FORMAT_ERROR);
294 r->wType = rrec->rr_type;
295 r->dwTtlSeconds = rrec->ttl;
296 r->rank = DNS_RANK_ZONE;
297 /* TODO: Autogenerate this somehow */
300 /* If we get QCLASS_ANY, we're done here */
301 if (rrec->rr_class == DNS_QCLASS_ANY) {
305 switch(rrec->rr_type) {
307 r->data.ipv4 = talloc_strdup(mem_ctx, rrec->rdata.ipv4_record);
308 W_ERROR_HAVE_NO_MEMORY(r->data.ipv4);
311 r->data.ipv6 = talloc_strdup(mem_ctx, rrec->rdata.ipv6_record);
312 W_ERROR_HAVE_NO_MEMORY(r->data.ipv6);
315 r->data.ns = talloc_strdup(mem_ctx, rrec->rdata.ns_record);
316 W_ERROR_HAVE_NO_MEMORY(r->data.ns);
318 case DNS_QTYPE_CNAME:
319 r->data.cname = talloc_strdup(mem_ctx, rrec->rdata.cname_record);
320 W_ERROR_HAVE_NO_MEMORY(r->data.cname);
323 r->data.srv.wPriority = rrec->rdata.srv_record.priority;
324 r->data.srv.wWeight = rrec->rdata.srv_record.weight;
325 r->data.srv.wPort = rrec->rdata.srv_record.port;
326 r->data.srv.nameTarget = talloc_strdup(mem_ctx,
327 rrec->rdata.srv_record.target);
328 W_ERROR_HAVE_NO_MEMORY(r->data.srv.nameTarget);
331 r->data.mx.wPriority = rrec->rdata.mx_record.preference;
332 r->data.mx.nameTarget = talloc_strdup(mem_ctx,
333 rrec->rdata.mx_record.exchange);
334 W_ERROR_HAVE_NO_MEMORY(r->data.mx.nameTarget);
337 r->data.txt = talloc_strdup(mem_ctx, rrec->rdata.txt_record.txt);
338 W_ERROR_HAVE_NO_MEMORY(r->data.txt);
341 DEBUG(0, ("Got a qytpe of %d\n", rrec->rr_type));
342 return DNS_ERR(NOT_IMPLEMENTED);
351 static WERROR handle_one_update(struct dns_server *dns,
353 const struct dns_name_question *zone,
354 const struct dns_res_rec *update)
356 struct dnsp_DnssrvRpcRecord *recs = NULL;
361 bool needs_add = false;
363 DEBUG(1, ("Looking at record: \n"));
364 NDR_PRINT_DEBUG(dns_res_rec, discard_const(update));
366 switch (update->rr_type) {
371 case DNS_QTYPE_CNAME:
386 return DNS_ERR(NOT_IMPLEMENTED);
389 werror = dns_name2dn(dns, mem_ctx, update->name, &dn);
390 W_ERROR_NOT_OK_RETURN(werror);
392 werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rcount);
393 if (W_ERROR_EQUAL(werror, DNS_ERR(NAME_ERROR))) {
399 W_ERROR_NOT_OK_RETURN(werror);
401 if (update->rr_class == zone->question_class) {
402 if (update->rr_type == DNS_QTYPE_CNAME) {
404 * If there is a record in the directory
405 * that's not a CNAME, ignore update
407 for (i = 0; i < rcount; i++) {
408 if (recs[i].wType != DNS_TYPE_CNAME) {
409 DEBUG(0, ("Skipping update\n"));
416 * There should be no entries besides one CNAME record
417 * per name, so replace everything with the new CNAME
421 recs = talloc_realloc(mem_ctx, recs,
422 struct dnsp_DnssrvRpcRecord, rcount);
423 W_ERROR_HAVE_NO_MEMORY(recs);
425 werror = dns_rr_to_dnsp(recs, update, &recs[0]);
426 W_ERROR_NOT_OK_RETURN(werror);
428 werror = dns_replace_records(dns, mem_ctx, dn,
429 needs_add, recs, rcount);
430 W_ERROR_NOT_OK_RETURN(werror);
435 * If there is a CNAME record for this name,
438 for (i = 0; i < rcount; i++) {
439 if (recs[i].wType == DNS_TYPE_CNAME) {
440 DEBUG(0, ("Skipping update\n"));
445 if (update->rr_type == DNS_QTYPE_SOA) {
449 * If the zone has no SOA record?? or update's
450 * serial number is smaller than existing SOA's,
453 for (i = 0; i < rcount; i++) {
454 if (recs[i].wType == DNS_TYPE_SOA) {
457 n = update->rdata.soa_record.serial;
458 o = recs[i].data.soa.serial;
460 * TODO: Implement RFC 1982 comparison
464 DEBUG(0, ("Skipping update\n"));
472 DEBUG(0, ("Skipping update\n"));
476 werror = dns_rr_to_dnsp(mem_ctx, update, &recs[i]);
477 W_ERROR_NOT_OK_RETURN(werror);
479 for (i++; i < rcount; i++) {
480 if (recs[i].wType != DNS_TYPE_SOA) {
484 ZERO_STRUCT(recs[i]);
487 werror = dns_replace_records(dns, mem_ctx, dn,
488 needs_add, recs, rcount);
489 W_ERROR_NOT_OK_RETURN(werror);
494 recs = talloc_realloc(mem_ctx, recs,
495 struct dnsp_DnssrvRpcRecord, rcount+1);
496 W_ERROR_HAVE_NO_MEMORY(recs);
498 werror = dns_rr_to_dnsp(recs, update, &recs[rcount]);
499 W_ERROR_NOT_OK_RETURN(werror);
501 for (i = 0; i < rcount; i++) {
502 if (!dns_records_match(&recs[i], &recs[rcount])) {
506 recs[i] = recs[rcount];
508 werror = dns_replace_records(dns, mem_ctx, dn,
509 needs_add, recs, rcount);
510 W_ERROR_NOT_OK_RETURN(werror);
515 werror = dns_replace_records(dns, mem_ctx, dn,
516 needs_add, recs, rcount+1);
517 W_ERROR_NOT_OK_RETURN(werror);
520 } else if (update->rr_class == DNS_QCLASS_ANY) {
521 if (update->rr_type == DNS_QTYPE_ALL) {
522 if (dns_name_equal(update->name, zone->name)) {
523 for (i = 0; i < rcount; i++) {
525 if (recs[i].wType == DNS_TYPE_SOA) {
529 if (recs[i].wType == DNS_TYPE_NS) {
533 ZERO_STRUCT(recs[i]);
537 for (i = 0; i < rcount; i++) {
538 ZERO_STRUCT(recs[i]);
542 } else if (dns_name_equal(update->name, zone->name)) {
544 if (update->rr_type == DNS_QTYPE_SOA) {
548 if (update->rr_type == DNS_QTYPE_NS) {
552 for (i = 0; i < rcount; i++) {
553 if (recs[i].wType == update->rr_type) {
554 ZERO_STRUCT(recs[i]);
558 werror = dns_replace_records(dns, mem_ctx, dn,
559 needs_add, recs, rcount);
560 W_ERROR_NOT_OK_RETURN(werror);
563 } else if (update->rr_class == DNS_QCLASS_NONE) {
564 struct dnsp_DnssrvRpcRecord *del_rec;
566 if (update->rr_type == DNS_QTYPE_SOA) {
569 if (update->rr_type == DNS_QTYPE_NS) {
571 struct dnsp_DnssrvRpcRecord *ns_rec = talloc(mem_ctx,
572 struct dnsp_DnssrvRpcRecord);
573 W_ERROR_HAVE_NO_MEMORY(ns_rec);
576 werror = dns_rr_to_dnsp(ns_rec, update, ns_rec);
577 W_ERROR_NOT_OK_RETURN(werror);
579 for (i = 0; i < rcount; i++) {
580 if (dns_records_match(ns_rec, &recs[i])) {
590 del_rec = talloc(mem_ctx, struct dnsp_DnssrvRpcRecord);
591 W_ERROR_HAVE_NO_MEMORY(del_rec);
593 werror = dns_rr_to_dnsp(del_rec, update, del_rec);
594 W_ERROR_NOT_OK_RETURN(werror);
596 for (i = 0; i < rcount; i++) {
597 if (dns_records_match(del_rec, &recs[i])) {
598 ZERO_STRUCT(recs[i]);
606 static WERROR handle_updates(struct dns_server *dns,
608 const struct dns_name_question *zone,
609 const struct dns_res_rec *prereqs, uint16_t pcount,
610 struct dns_res_rec *updates, uint16_t upd_count)
612 struct ldb_dn *zone_dn = NULL;
613 WERROR werror = WERR_OK;
616 TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
618 werror = dns_name2dn(dns, tmp_ctx, zone->name, &zone_dn);
619 W_ERROR_NOT_OK_RETURN(werror);
621 ret = ldb_transaction_start(dns->samdb);
622 if (ret != LDB_SUCCESS) {
623 return DNS_ERR(SERVER_FAILURE);
626 werror = check_prerequisites(dns, tmp_ctx, zone, prereqs, pcount);
627 W_ERROR_NOT_OK_GOTO(werror, failed);
629 DEBUG(0, ("update count is %u\n", upd_count));
631 for (ri = 0; ri < upd_count; ri++) {
632 werror = handle_one_update(dns, tmp_ctx, zone,
634 W_ERROR_NOT_OK_GOTO(werror, failed);
637 ldb_transaction_commit(dns->samdb);
638 TALLOC_FREE(tmp_ctx);
642 ldb_transaction_cancel(dns->samdb);
643 TALLOC_FREE(tmp_ctx);
648 WERROR dns_server_process_update(struct dns_server *dns,
650 struct dns_name_packet *in,
651 struct dns_res_rec **prereqs, uint16_t *prereq_count,
652 struct dns_res_rec **updates, uint16_t *update_count,
653 struct dns_res_rec **additional, uint16_t *arcount)
655 struct dns_name_question *zone;
656 const struct dns_server_zone *z;
657 size_t host_part_len = 0;
658 WERROR werror = DNS_ERR(NOT_IMPLEMENTED);
660 if (in->qdcount != 1) {
661 return DNS_ERR(FORMAT_ERROR);
664 zone = &in->questions[0];
666 if (zone->question_class != DNS_QCLASS_IN &&
667 zone->question_class != DNS_QCLASS_ANY) {
668 return DNS_ERR(NOT_IMPLEMENTED);
671 if (zone->question_type != DNS_QTYPE_SOA) {
672 return DNS_ERR(FORMAT_ERROR);
675 DEBUG(0, ("Got a dns update request.\n"));
677 for (z = dns->zones; z != NULL; z = z->next) {
680 match = dns_name_match(z->name, zone->name, &host_part_len);
687 DEBUG(0, ("We're not authorative for this zone\n"));
688 return DNS_ERR(NOTAUTH);
691 if (host_part_len != 0) {
692 /* TODO: We need to delegate this one */
693 DEBUG(0, ("Would have to delegate zones.\n"));
694 return DNS_ERR(NOT_IMPLEMENTED);
697 *prereq_count = in->ancount;
698 *prereqs = in->answers;
699 werror = check_prerequisites(dns, mem_ctx, in->questions, *prereqs,
701 W_ERROR_NOT_OK_RETURN(werror);
703 /* TODO: Check if update is allowed, we probably want "always",
704 * key-based GSSAPI, key-based bind-style TSIG and "never" as
705 * smb.conf options. */
706 if (lpcfg_allow_dns_updates(dns->task->lp_ctx) != DNS_UPDATE_ON) {
707 DEBUG(0, ("Update not allowed."));
708 return DNS_ERR(REFUSED);
711 *update_count = in->nscount;
712 *updates = in->nsrecs;
713 werror = update_prescan(in->questions, *updates, *update_count);
714 W_ERROR_NOT_OK_RETURN(werror);
717 werror = handle_updates(dns, mem_ctx, in->questions, *prereqs,
718 *prereq_count, *updates, *update_count);
719 W_ERROR_NOT_OK_RETURN(werror);