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netlogon_creds_cli: Create cli_credentials from netlogon creds ctx
[Samba.git] / source4 / dns_server / dns_query.c
blobfa9272156abf0fa53707bc989b6d39c6e2e8859d
1 /*
2 Unix SMB/CIFS implementation.
3
4 DNS server handler for queries
5
6 Copyright (C) 2010 Kai Blin <kai@samba.org>
7
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.
12
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.
17
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/>.
20 */
21
22 #include "includes.h"
23 #include "smbd/service_task.h"
24 #include "libcli/util/werror.h"
25 #include "librpc/ndr/libndr.h"
26 #include "librpc/gen_ndr/ndr_dns.h"
27 #include "librpc/gen_ndr/ndr_dnsp.h"
28 #include <ldb.h>
29 #include "param/param.h"
30 #include "dsdb/samdb/samdb.h"
31 #include "dsdb/common/util.h"
32 #include "dns_server/dns_server.h"
33 #include "libcli/dns/libdns.h"
34 #include "lib/util/dlinklist.h"
35 #include "lib/util/util_net.h"
36 #include "lib/util/tevent_werror.h"
37 #include "auth/auth.h"
38 #include "auth/credentials/credentials.h"
39 #include "auth/gensec/gensec.h"
40
41 #undef DBGC_CLASS
42 #define DBGC_CLASS DBGC_DNS
43
44 struct forwarder_string {
45 const char *forwarder;
46 struct forwarder_string *prev, *next;
47 };
48
49 static WERROR add_response_rr(const char *name,
50 const struct dnsp_DnssrvRpcRecord *rec,
51 struct dns_res_rec **answers)
52 {
53 struct dns_res_rec *ans = *answers;
54 uint16_t ai = talloc_array_length(ans);
55 enum ndr_err_code ndr_err;
56
57 if (ai == UINT16_MAX) {
58 return WERR_BUFFER_OVERFLOW;
59 }
60
61 /*
62 * "ans" is always non-NULL and thus its own talloc context
63 */
64 ans = talloc_realloc(ans, ans, struct dns_res_rec, ai+1);
65 if (ans == NULL) {
66 return WERR_NOT_ENOUGH_MEMORY;
67 }
68
69 ZERO_STRUCT(ans[ai]);
70
71 switch (rec->wType) {
72 case DNS_QTYPE_CNAME:
73 ans[ai].rdata.cname_record = talloc_strdup(ans, rec->data.cname);
74 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.cname_record);
75 break;
76 case DNS_QTYPE_A:
77 ans[ai].rdata.ipv4_record = talloc_strdup(ans, rec->data.ipv4);
78 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ipv4_record);
79 break;
80 case DNS_QTYPE_AAAA:
81 ans[ai].rdata.ipv6_record = talloc_strdup(ans, rec->data.ipv6);
82 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ipv6_record);
83 break;
84 case DNS_TYPE_NS:
85 ans[ai].rdata.ns_record = talloc_strdup(ans, rec->data.ns);
86 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ns_record);
87 break;
88 case DNS_QTYPE_SRV:
89 ans[ai].rdata.srv_record.priority = rec->data.srv.wPriority;
90 ans[ai].rdata.srv_record.weight = rec->data.srv.wWeight;
91 ans[ai].rdata.srv_record.port = rec->data.srv.wPort;
92 ans[ai].rdata.srv_record.target = talloc_strdup(
93 ans, rec->data.srv.nameTarget);
94 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.srv_record.target);
95 break;
96 case DNS_QTYPE_SOA:
97 ans[ai].rdata.soa_record.mname = talloc_strdup(
98 ans, rec->data.soa.mname);
99 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.soa_record.mname);
100 ans[ai].rdata.soa_record.rname = talloc_strdup(
101 ans, rec->data.soa.rname);
102 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.soa_record.rname);
103 ans[ai].rdata.soa_record.serial = rec->data.soa.serial;
104 ans[ai].rdata.soa_record.refresh = rec->data.soa.refresh;
105 ans[ai].rdata.soa_record.retry = rec->data.soa.retry;
106 ans[ai].rdata.soa_record.expire = rec->data.soa.expire;
107 ans[ai].rdata.soa_record.minimum = rec->data.soa.minimum;
108 break;
109 case DNS_QTYPE_PTR:
110 ans[ai].rdata.ptr_record = talloc_strdup(ans, rec->data.ptr);
111 W_ERROR_HAVE_NO_MEMORY(ans[ai].rdata.ptr_record);
112 break;
113 case DNS_QTYPE_MX:
114 ans[ai].rdata.mx_record.preference = rec->data.mx.wPriority;
115 ans[ai].rdata.mx_record.exchange = talloc_strdup(
116 ans, rec->data.mx.nameTarget);
117 if (ans[ai].rdata.mx_record.exchange == NULL) {
118 return WERR_NOT_ENOUGH_MEMORY;
119 }
120 break;
121 case DNS_QTYPE_TXT:
122 ndr_err = ndr_dnsp_string_list_copy(ans,
123 &rec->data.txt,
124 &ans[ai].rdata.txt_record.txt);
125 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
126 return WERR_NOT_ENOUGH_MEMORY;
127 }
128 break;
129 default:
130 DEBUG(0, ("Got unhandled type %u query.\n", rec->wType));
131 return DNS_ERR(NOT_IMPLEMENTED);
132 }
133
134 ans[ai].name = talloc_strdup(ans, name);
135 W_ERROR_HAVE_NO_MEMORY(ans[ai].name);
136 ans[ai].rr_type = rec->wType;
137 ans[ai].rr_class = DNS_QCLASS_IN;
138 ans[ai].ttl = rec->dwTtlSeconds;
139 ans[ai].length = UINT16_MAX;
140
141 *answers = ans;
142
143 return WERR_OK;
144 }
145
146 static WERROR add_dns_res_rec(struct dns_res_rec **pdst,
147 const struct dns_res_rec *src)
148 {
149 struct dns_res_rec *dst = *pdst;
150 uint16_t di = talloc_array_length(dst);
151 enum ndr_err_code ndr_err;
152
153 if (di == UINT16_MAX) {
154 return WERR_BUFFER_OVERFLOW;
155 }
156
157 dst = talloc_realloc(dst, dst, struct dns_res_rec, di+1);
158 if (dst == NULL) {
159 return WERR_NOT_ENOUGH_MEMORY;
160 }
161
162 ZERO_STRUCT(dst[di]);
163
164 dst[di] = (struct dns_res_rec) {
165 .name = talloc_strdup(dst, src->name),
166 .rr_type = src->rr_type,
167 .rr_class = src->rr_class,
168 .ttl = src->ttl,
169 .length = src->length
170 };
171
172 if (dst[di].name == NULL) {
173 return WERR_NOT_ENOUGH_MEMORY;
174 }
175
176 switch (src->rr_type) {
177 case DNS_QTYPE_CNAME:
178 dst[di].rdata.cname_record = talloc_strdup(
179 dst, src->rdata.cname_record);
180 if (dst[di].rdata.cname_record == NULL) {
181 return WERR_NOT_ENOUGH_MEMORY;
182 }
183 break;
184 case DNS_QTYPE_A:
185 dst[di].rdata.ipv4_record = talloc_strdup(
186 dst, src->rdata.ipv4_record);
187 if (dst[di].rdata.ipv4_record == NULL) {
188 return WERR_NOT_ENOUGH_MEMORY;
189 }
190 break;
191 case DNS_QTYPE_AAAA:
192 dst[di].rdata.ipv6_record = talloc_strdup(
193 dst, src->rdata.ipv6_record);
194 if (dst[di].rdata.ipv6_record == NULL) {
195 return WERR_NOT_ENOUGH_MEMORY;
196 }
197 break;
198 case DNS_TYPE_NS:
199 dst[di].rdata.ns_record = talloc_strdup(
200 dst, src->rdata.ns_record);
201 if (dst[di].rdata.ns_record == NULL) {
202 return WERR_NOT_ENOUGH_MEMORY;
203 }
204 break;
205 case DNS_QTYPE_SRV:
206 dst[di].rdata.srv_record = (struct dns_srv_record) {
207 .priority = src->rdata.srv_record.priority,
208 .weight = src->rdata.srv_record.weight,
209 .port = src->rdata.srv_record.port,
210 .target = talloc_strdup(
211 dst, src->rdata.srv_record.target)
212 };
213 if (dst[di].rdata.srv_record.target == NULL) {
214 return WERR_NOT_ENOUGH_MEMORY;
215 }
216 break;
217 case DNS_QTYPE_SOA:
218 dst[di].rdata.soa_record = (struct dns_soa_record) {
219 .mname = talloc_strdup(
220 dst, src->rdata.soa_record.mname),
221 .rname = talloc_strdup(
222 dst, src->rdata.soa_record.rname),
223 .serial = src->rdata.soa_record.serial,
224 .refresh = src->rdata.soa_record.refresh,
225 .retry = src->rdata.soa_record.retry,
226 .expire = src->rdata.soa_record.expire,
227 .minimum = src->rdata.soa_record.minimum
228 };
229
230 if ((dst[di].rdata.soa_record.mname == NULL) ||
231 (dst[di].rdata.soa_record.rname == NULL)) {
232 return WERR_NOT_ENOUGH_MEMORY;
233 }
234
235 break;
236 case DNS_QTYPE_PTR:
237 dst[di].rdata.ptr_record = talloc_strdup(
238 dst, src->rdata.ptr_record);
239 if (dst[di].rdata.ptr_record == NULL) {
240 return WERR_NOT_ENOUGH_MEMORY;
241 }
242 break;
243 case DNS_QTYPE_MX:
244 dst[di].rdata.mx_record = (struct dns_mx_record) {
245 .preference = src->rdata.mx_record.preference,
246 .exchange = talloc_strdup(
247 src, src->rdata.mx_record.exchange)
248 };
249
250 if (dst[di].rdata.mx_record.exchange == NULL) {
251 return WERR_NOT_ENOUGH_MEMORY;
252 }
253 break;
254 case DNS_QTYPE_TXT:
255 ndr_err = ndr_dnsp_string_list_copy(dst,
256 &src->rdata.txt_record.txt,
257 &dst[di].rdata.txt_record.txt);
258 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
259 return WERR_NOT_ENOUGH_MEMORY;
260 }
261 break;
262 default:
263 DBG_WARNING("Got unhandled type %u query.\n", src->rr_type);
264 return DNS_ERR(NOT_IMPLEMENTED);
265 }
266
267 *pdst = dst;
268
269 return WERR_OK;
270 }
271
272 struct ask_forwarder_state {
273 struct tevent_context *ev;
274 uint16_t id;
275 struct dns_name_packet in_packet;
276 };
277
278 static void ask_forwarder_done(struct tevent_req *subreq);
279
280 static struct tevent_req *ask_forwarder_send(
281 TALLOC_CTX *mem_ctx, struct tevent_context *ev,
282 struct dns_server *dns,
283 const char *forwarder, struct dns_name_question *question)
284 {
285 struct tevent_req *req, *subreq;
286 struct ask_forwarder_state *state;
287 struct dns_res_rec *options;
288 struct dns_name_packet out_packet = { 0, };
289 DATA_BLOB out_blob;
290 enum ndr_err_code ndr_err;
291 WERROR werr;
292
293 req = tevent_req_create(mem_ctx, &state, struct ask_forwarder_state);
294 if (req == NULL) {
295 return NULL;
296 }
297 state->ev = ev;
298 generate_random_buffer((uint8_t *)&state->id, sizeof(state->id));
299
300 if (!is_ipaddress(forwarder)) {
301 DEBUG(0, ("Invalid 'dns forwarder' setting '%s', needs to be "
302 "an IP address\n", forwarder));
303 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
304 return tevent_req_post(req, ev);
305 }
306
307 out_packet.id = state->id;
308 out_packet.operation |= DNS_OPCODE_QUERY | DNS_FLAG_RECURSION_DESIRED;
309 out_packet.qdcount = 1;
310 out_packet.questions = question;
311
312 werr = dns_generate_options(dns, state, &options);
313 if (!W_ERROR_IS_OK(werr)) {
314 tevent_req_werror(req, werr);
315 return tevent_req_post(req, ev);
316 }
317
318 out_packet.arcount = 1;
319 out_packet.additional = options;
320
321 ndr_err = ndr_push_struct_blob(
322 &out_blob, state, &out_packet,
323 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
324 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
325 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
326 return tevent_req_post(req, ev);
327 }
328 subreq = dns_udp_request_send(state, ev, forwarder, out_blob.data,
329 out_blob.length);
330 if (tevent_req_nomem(subreq, req)) {
331 return tevent_req_post(req, ev);
332 }
333 tevent_req_set_callback(subreq, ask_forwarder_done, req);
334 return req;
335 }
336
337 static void ask_forwarder_done(struct tevent_req *subreq)
338 {
339 struct tevent_req *req = tevent_req_callback_data(
340 subreq, struct tevent_req);
341 struct ask_forwarder_state *state = tevent_req_data(
342 req, struct ask_forwarder_state);
343 DATA_BLOB in_blob;
344 enum ndr_err_code ndr_err;
345 int ret;
346
347 ret = dns_udp_request_recv(subreq, state,
348 &in_blob.data, &in_blob.length);
349 TALLOC_FREE(subreq);
350
351 if (ret != 0) {
352 tevent_req_werror(req, unix_to_werror(ret));
353 return;
354 }
355
356 ndr_err = ndr_pull_struct_blob(
357 &in_blob, state, &state->in_packet,
358 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
359 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
360 tevent_req_werror(req, DNS_ERR(SERVER_FAILURE));
361 return;
362 }
363 if (state->in_packet.id != state->id) {
364 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
365 return;
366 }
367 tevent_req_done(req);
368 }
369
370 static WERROR ask_forwarder_recv(
371 struct tevent_req *req, TALLOC_CTX *mem_ctx,
372 struct dns_res_rec **answers, uint16_t *ancount,
373 struct dns_res_rec **nsrecs, uint16_t *nscount,
374 struct dns_res_rec **additional, uint16_t *arcount)
375 {
376 struct ask_forwarder_state *state = tevent_req_data(
377 req, struct ask_forwarder_state);
378 struct dns_name_packet *in_packet = &state->in_packet;
379 WERROR err;
380
381 if (tevent_req_is_werror(req, &err)) {
382 return err;
383 }
384
385 *ancount = in_packet->ancount;
386 *answers = talloc_move(mem_ctx, &in_packet->answers);
387
388 *nscount = in_packet->nscount;
389 *nsrecs = talloc_move(mem_ctx, &in_packet->nsrecs);
390
391 *arcount = in_packet->arcount;
392 *additional = talloc_move(mem_ctx, &in_packet->additional);
393
394 return WERR_OK;
395 }
396
397 static WERROR add_zone_authority_record(struct dns_server *dns,
398 TALLOC_CTX *mem_ctx,
399 const struct dns_name_question *question,
400 struct dns_res_rec **nsrecs)
401 {
402 const char *zone = NULL;
403 struct dnsp_DnssrvRpcRecord *recs;
404 struct dns_res_rec *ns = *nsrecs;
405 uint16_t rec_count;
406 struct ldb_dn *dn = NULL;
407 unsigned int ri;
408 WERROR werror;
409
410 zone = dns_get_authoritative_zone(dns, question->name);
411 DEBUG(10, ("Creating zone authority record for '%s'\n", zone));
412
413 werror = dns_name2dn(dns, mem_ctx, zone, &dn);
414 if (!W_ERROR_IS_OK(werror)) {
415 return werror;
416 }
417
418 werror = dns_lookup_records(dns, mem_ctx, dn, &recs, &rec_count);
419 if (!W_ERROR_IS_OK(werror)) {
420 return werror;
421 }
422
423 for (ri = 0; ri < rec_count; ri++) {
424 if (recs[ri].wType == DNS_TYPE_SOA) {
425 werror = add_response_rr(zone, &recs[ri], &ns);
426 if (!W_ERROR_IS_OK(werror)) {
427 return werror;
428 }
429 }
430 }
431
432 *nsrecs = ns;
433
434 return WERR_OK;
435 }
436
437 static struct tevent_req *handle_authoritative_send(
438 TALLOC_CTX *mem_ctx, struct tevent_context *ev,
439 struct dns_server *dns, const char *forwarder,
440 struct dns_name_question *question,
441 struct dns_res_rec **answers, struct dns_res_rec **nsrecs);
442 static WERROR handle_authoritative_recv(struct tevent_req *req);
443
444 struct handle_dnsrpcrec_state {
445 struct dns_res_rec **answers;
446 struct dns_res_rec **nsrecs;
447 };
448
449 static void handle_dnsrpcrec_gotauth(struct tevent_req *subreq);
450 static void handle_dnsrpcrec_gotforwarded(struct tevent_req *subreq);
451
452 static struct tevent_req *handle_dnsrpcrec_send(
453 TALLOC_CTX *mem_ctx, struct tevent_context *ev,
454 struct dns_server *dns, const char *forwarder,
455 const struct dns_name_question *question,
456 struct dnsp_DnssrvRpcRecord *rec,
457 struct dns_res_rec **answers, struct dns_res_rec **nsrecs)
458 {
459 struct tevent_req *req, *subreq;
460 struct handle_dnsrpcrec_state *state;
461 struct dns_name_question *new_q;
462 bool resolve_cname;
463 WERROR werr;
464
465 req = tevent_req_create(mem_ctx, &state,
466 struct handle_dnsrpcrec_state);
467 if (req == NULL) {
468 return NULL;
469 }
470 state->answers = answers;
471 state->nsrecs = nsrecs;
472
473 resolve_cname = ((rec->wType == DNS_TYPE_CNAME) &&
474 ((question->question_type == DNS_QTYPE_A) ||
475 (question->question_type == DNS_QTYPE_AAAA)));
476
477 if (!resolve_cname) {
478 if ((question->question_type != DNS_QTYPE_ALL) &&
479 (rec->wType !=
480 (enum dns_record_type) question->question_type)) {
481 tevent_req_done(req);
482 return tevent_req_post(req, ev);
483 }
484
485 werr = add_response_rr(question->name, rec, state->answers);
486 if (tevent_req_werror(req, werr)) {
487 return tevent_req_post(req, ev);
488 }
489
490 tevent_req_done(req);
491 return tevent_req_post(req, ev);
492 }
493
494 werr = add_response_rr(question->name, rec, state->answers);
495 if (tevent_req_werror(req, werr)) {
496 return tevent_req_post(req, ev);
497 }
498
499 new_q = talloc(state, struct dns_name_question);
500 if (tevent_req_nomem(new_q, req)) {
501 return tevent_req_post(req, ev);
502 }
503
504 *new_q = (struct dns_name_question) {
505 .question_type = question->question_type,
506 .question_class = question->question_class,
507 .name = rec->data.cname
508 };
509
510 if (dns_authoritative_for_zone(dns, new_q->name)) {
511 subreq = handle_authoritative_send(
512 state, ev, dns, forwarder, new_q,
513 state->answers, state->nsrecs);
514 if (tevent_req_nomem(subreq, req)) {
515 return tevent_req_post(req, ev);
516 }
517 tevent_req_set_callback(subreq, handle_dnsrpcrec_gotauth, req);
518 return req;
519 }
520
521 subreq = ask_forwarder_send(state, ev, dns, forwarder, new_q);
522 if (tevent_req_nomem(subreq, req)) {
523 return tevent_req_post(req, ev);
524 }
525 tevent_req_set_callback(subreq, handle_dnsrpcrec_gotforwarded, req);
526
527 return req;
528 }
529
530 static void handle_dnsrpcrec_gotauth(struct tevent_req *subreq)
531 {
532 struct tevent_req *req = tevent_req_callback_data(
533 subreq, struct tevent_req);
534 WERROR werr;
535
536 werr = handle_authoritative_recv(subreq);
537 TALLOC_FREE(subreq);
538 if (tevent_req_werror(req, werr)) {
539 return;
540 }
541 tevent_req_done(req);
542 }
543
544 static void handle_dnsrpcrec_gotforwarded(struct tevent_req *subreq)
545 {
546 struct tevent_req *req = tevent_req_callback_data(
547 subreq, struct tevent_req);
548 struct handle_dnsrpcrec_state *state = tevent_req_data(
549 req, struct handle_dnsrpcrec_state);
550 struct dns_res_rec *answers, *nsrecs, *additional;
551 uint16_t ancount = 0;
552 uint16_t nscount = 0;
553 uint16_t arcount = 0;
554 uint16_t i;
555 WERROR werr;
556
557 werr = ask_forwarder_recv(subreq, state, &answers, &ancount,
558 &nsrecs, &nscount, &additional, &arcount);
559 if (tevent_req_werror(req, werr)) {
560 return;
561 }
562
563 for (i=0; i<ancount; i++) {
564 werr = add_dns_res_rec(state->answers, &answers[i]);
565 if (tevent_req_werror(req, werr)) {
566 return;
567 }
568 }
569
570 for (i=0; i<nscount; i++) {
571 werr = add_dns_res_rec(state->nsrecs, &nsrecs[i]);
572 if (tevent_req_werror(req, werr)) {
573 return;
574 }
575 }
576
577 tevent_req_done(req);
578 }
579
580 static WERROR handle_dnsrpcrec_recv(struct tevent_req *req)
581 {
582 return tevent_req_simple_recv_werror(req);
583 }
584
585 struct handle_authoritative_state {
586 struct tevent_context *ev;
587 struct dns_server *dns;
588 struct dns_name_question *question;
589 const char *forwarder;
590
591 struct dnsp_DnssrvRpcRecord *recs;
592 uint16_t rec_count;
593 uint16_t recs_done;
594
595 struct dns_res_rec **answers;
596 struct dns_res_rec **nsrecs;
597 };
598
599 static void handle_authoritative_done(struct tevent_req *subreq);
600
601 static struct tevent_req *handle_authoritative_send(
602 TALLOC_CTX *mem_ctx, struct tevent_context *ev,
603 struct dns_server *dns, const char *forwarder,
604 struct dns_name_question *question,
605 struct dns_res_rec **answers, struct dns_res_rec **nsrecs)
606 {
607 struct tevent_req *req, *subreq;
608 struct handle_authoritative_state *state;
609 struct ldb_dn *dn = NULL;
610 WERROR werr;
611
612 req = tevent_req_create(mem_ctx, &state,
613 struct handle_authoritative_state);
614 if (req == NULL) {
615 return NULL;
616 }
617 state->ev = ev;
618 state->dns = dns;
619 state->question = question;
620 state->forwarder = forwarder;
621 state->answers = answers;
622 state->nsrecs = nsrecs;
623
624 werr = dns_name2dn(dns, state, question->name, &dn);
625 if (tevent_req_werror(req, werr)) {
626 return tevent_req_post(req, ev);
627 }
628 werr = dns_lookup_records_wildcard(dns, state, dn, &state->recs,
629 &state->rec_count);
630 TALLOC_FREE(dn);
631 if (tevent_req_werror(req, werr)) {
632 return tevent_req_post(req, ev);
633 }
634
635 if (state->rec_count == 0) {
636 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
637 return tevent_req_post(req, ev);
638 }
639
640 subreq = handle_dnsrpcrec_send(
641 state, state->ev, state->dns, state->forwarder,
642 state->question, &state->recs[state->recs_done],
643 state->answers, state->nsrecs);
644 if (tevent_req_nomem(subreq, req)) {
645 return tevent_req_post(req, ev);
646 }
647 tevent_req_set_callback(subreq, handle_authoritative_done, req);
648 return req;
649 }
650
651 static void handle_authoritative_done(struct tevent_req *subreq)
652 {
653 struct tevent_req *req = tevent_req_callback_data(
654 subreq, struct tevent_req);
655 struct handle_authoritative_state *state = tevent_req_data(
656 req, struct handle_authoritative_state);
657 WERROR werr;
658
659 werr = handle_dnsrpcrec_recv(subreq);
660 TALLOC_FREE(subreq);
661 if (tevent_req_werror(req, werr)) {
662 return;
663 }
664
665 state->recs_done += 1;
666
667 if (state->recs_done == state->rec_count) {
668 tevent_req_done(req);
669 return;
670 }
671
672 subreq = handle_dnsrpcrec_send(
673 state, state->ev, state->dns, state->forwarder,
674 state->question, &state->recs[state->recs_done],
675 state->answers, state->nsrecs);
676 if (tevent_req_nomem(subreq, req)) {
677 return;
678 }
679 tevent_req_set_callback(subreq, handle_authoritative_done, req);
680 }
681
682 static WERROR handle_authoritative_recv(struct tevent_req *req)
683 {
684 struct handle_authoritative_state *state = tevent_req_data(
685 req, struct handle_authoritative_state);
686 WERROR werr;
687
688 if (tevent_req_is_werror(req, &werr)) {
689 return werr;
690 }
691
692 werr = add_zone_authority_record(state->dns, state, state->question,
693 state->nsrecs);
694 if (!W_ERROR_IS_OK(werr)) {
695 return werr;
696 }
697
698 return WERR_OK;
699 }
700
701 static NTSTATUS create_tkey(struct dns_server *dns,
702 const char* name,
703 const char* algorithm,
704 const struct tsocket_address *remote_address,
705 const struct tsocket_address *local_address,
706 struct dns_server_tkey **tkey)
707 {
708 NTSTATUS status;
709 struct dns_server_tkey_store *store = dns->tkeys;
710 struct dns_server_tkey *k = talloc_zero(store, struct dns_server_tkey);
711
712 if (k == NULL) {
713 return NT_STATUS_NO_MEMORY;
714 }
715
716 k->name = talloc_strdup(k, name);
717
718 if (k->name == NULL) {
719 return NT_STATUS_NO_MEMORY;
720 }
721
722 k->algorithm = talloc_strdup(k, algorithm);
723 if (k->algorithm == NULL) {
724 return NT_STATUS_NO_MEMORY;
725 }
726
727 /*
728 * We only allow SPNEGO/KRB5 currently
729 * and rely on the backend to be RPC/IPC free.
730 *
731 * It allows gensec_update() not to block.
732 */
733 status = samba_server_gensec_krb5_start(k,
734 dns->task->event_ctx,
735 dns->task->msg_ctx,
736 dns->task->lp_ctx,
737 dns->server_credentials,
738 "dns",
739 &k->gensec);
740 if (!NT_STATUS_IS_OK(status)) {
741 DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
742 *tkey = NULL;
743 return status;
744 }
745
746 gensec_want_feature(k->gensec, GENSEC_FEATURE_SIGN);
747
748 status = gensec_set_remote_address(k->gensec,
749 remote_address);
750 if (!NT_STATUS_IS_OK(status)) {
751 DEBUG(1, ("Failed to set remote address into GENSEC: %s\n",
752 nt_errstr(status)));
753 *tkey = NULL;
754 return status;
755 }
756
757 status = gensec_set_local_address(k->gensec,
758 local_address);
759 if (!NT_STATUS_IS_OK(status)) {
760 DEBUG(1, ("Failed to set local address into GENSEC: %s\n",
761 nt_errstr(status)));
762 *tkey = NULL;
763 return status;
764 }
765
766 status = gensec_start_mech_by_oid(k->gensec, GENSEC_OID_SPNEGO);
767
768 if (!NT_STATUS_IS_OK(status)) {
769 DEBUG(1, ("Failed to start GENSEC server code: %s\n",
770 nt_errstr(status)));
771 *tkey = NULL;
772 return status;
773 }
774
775 if (store->tkeys[store->next_idx] != NULL) {
776 TALLOC_FREE(store->tkeys[store->next_idx]);
777 }
778
779 store->tkeys[store->next_idx] = k;
780 (store->next_idx)++;
781 store->next_idx %= store->size;
782
783 *tkey = k;
784 return NT_STATUS_OK;
785 }
786
787 static NTSTATUS accept_gss_ticket(TALLOC_CTX *mem_ctx,
788 struct dns_server *dns,
789 struct dns_server_tkey *tkey,
790 const DATA_BLOB *key,
791 DATA_BLOB *reply,
792 uint16_t *dns_auth_error)
793 {
794 NTSTATUS status;
795
796 /*
797 * We use samba_server_gensec_krb5_start(),
798 * which only allows SPNEGO/KRB5 currently
799 * and makes sure the backend to be RPC/IPC free.
800 *
801 * See gensec_gssapi_update_internal() as
802 * GENSEC_SERVER.
803 *
804 * It allows gensec_update() not to block.
805 *
806 * If that changes in future we need to use
807 * gensec_update_send/recv here!
808 */
809 status = gensec_update(tkey->gensec, mem_ctx,
810 *key, reply);
811
812 if (NT_STATUS_EQUAL(NT_STATUS_MORE_PROCESSING_REQUIRED, status)) {
813 *dns_auth_error = DNS_RCODE_OK;
814 return status;
815 }
816
817 if (NT_STATUS_IS_OK(status)) {
818
819 status = gensec_session_info(tkey->gensec, tkey, &tkey->session_info);
820 if (!NT_STATUS_IS_OK(status)) {
821 *dns_auth_error = DNS_RCODE_BADKEY;
822 return status;
823 }
824 *dns_auth_error = DNS_RCODE_OK;
825 }
826
827 return status;
828 }
829
830 static WERROR handle_tkey(struct dns_server *dns,
831 TALLOC_CTX *mem_ctx,
832 const struct dns_name_packet *in,
833 struct dns_request_state *state,
834 struct dns_res_rec **answers,
835 uint16_t *ancount)
836 {
837 struct dns_res_rec *in_tkey = NULL;
838 struct dns_res_rec *ret_tkey;
839 uint16_t i;
840
841 for (i = 0; i < in->arcount; i++) {
842 if (in->additional[i].rr_type == DNS_QTYPE_TKEY) {
843 in_tkey = &in->additional[i];
844 break;
845 }
846 }
847
848 /* If this is a TKEY query, it should have a TKEY RR.
849 * Behaviour is not really specified in RFC 2930 or RFC 3645, but
850 * FORMAT_ERROR seems to be what BIND uses .*/
851 if (in_tkey == NULL) {
852 return DNS_ERR(FORMAT_ERROR);
853 }
854
855 ret_tkey = talloc_zero(mem_ctx, struct dns_res_rec);
856 if (ret_tkey == NULL) {
857 return WERR_NOT_ENOUGH_MEMORY;
858 }
859
860 ret_tkey->name = talloc_strdup(ret_tkey, in_tkey->name);
861 if (ret_tkey->name == NULL) {
862 return WERR_NOT_ENOUGH_MEMORY;
863 }
864
865 ret_tkey->rr_type = DNS_QTYPE_TKEY;
866 ret_tkey->rr_class = DNS_QCLASS_ANY;
867 ret_tkey->length = UINT16_MAX;
868
869 ret_tkey->rdata.tkey_record.algorithm = talloc_strdup(ret_tkey,
870 in_tkey->rdata.tkey_record.algorithm);
871 if (ret_tkey->rdata.tkey_record.algorithm == NULL) {
872 return WERR_NOT_ENOUGH_MEMORY;
873 }
874
875 ret_tkey->rdata.tkey_record.inception = in_tkey->rdata.tkey_record.inception;
876 ret_tkey->rdata.tkey_record.expiration = in_tkey->rdata.tkey_record.expiration;
877 ret_tkey->rdata.tkey_record.mode = in_tkey->rdata.tkey_record.mode;
878
879 switch (in_tkey->rdata.tkey_record.mode) {
880 case DNS_TKEY_MODE_DH:
881 /* FIXME: According to RFC 2930, we MUST support this, but we don't.
882 * Still, claim it's a bad key instead of a bad mode */
883 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
884 break;
885 case DNS_TKEY_MODE_GSSAPI: {
886 NTSTATUS status;
887 struct dns_server_tkey *tkey;
888 DATA_BLOB key;
889 DATA_BLOB reply;
890
891 tkey = dns_find_tkey(dns->tkeys, in->questions[0].name);
892 if (tkey != NULL && tkey->complete) {
893 /* TODO: check if the key is still valid */
894 DEBUG(1, ("Rejecting tkey negotiation for already established key\n"));
895 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADNAME;
896 break;
897 }
898
899 if (tkey == NULL) {
900 status = create_tkey(dns, in->questions[0].name,
901 in_tkey->rdata.tkey_record.algorithm,
902 state->remote_address,
903 state->local_address,
904 &tkey);
905 if (!NT_STATUS_IS_OK(status)) {
906 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
907 return ntstatus_to_werror(status);
908 }
909 }
910
911 key.data = in_tkey->rdata.tkey_record.key_data;
912 key.length = in_tkey->rdata.tkey_record.key_size;
913
914 status = accept_gss_ticket(ret_tkey, dns, tkey, &key, &reply,
915 &ret_tkey->rdata.tkey_record.error);
916 if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
917 DEBUG(1, ("More processing required\n"));
918 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
919 } else if (NT_STATUS_IS_OK(status)) {
920 DEBUG(1, ("Tkey handshake completed\n"));
921 ret_tkey->rdata.tkey_record.key_size = reply.length;
922 ret_tkey->rdata.tkey_record.key_data = talloc_memdup(ret_tkey,
923 reply.data,
924 reply.length);
925 state->sign = true;
926 state->key_name = talloc_strdup(state->mem_ctx, tkey->name);
927 if (state->key_name == NULL) {
928 return WERR_NOT_ENOUGH_MEMORY;
929 }
930 } else {
931 DEBUG(1, ("GSS key negotiation returned %s\n", nt_errstr(status)));
932 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADKEY;
933 }
934
935 break;
936 }
937 case DNS_TKEY_MODE_DELETE:
938 /* TODO: implement me */
939 DEBUG(1, ("Should delete tkey here\n"));
940 ret_tkey->rdata.tkey_record.error = DNS_RCODE_OK;
941 break;
942 case DNS_TKEY_MODE_NULL:
943 case DNS_TKEY_MODE_SERVER:
944 case DNS_TKEY_MODE_CLIENT:
945 case DNS_TKEY_MODE_LAST:
946 /* We don't have to implement these, return a mode error */
947 ret_tkey->rdata.tkey_record.error = DNS_RCODE_BADMODE;
948 break;
949 default:
950 DEBUG(1, ("Unsupported TKEY mode %d\n",
951 in_tkey->rdata.tkey_record.mode));
952 }
953
954 *answers = ret_tkey;
955 *ancount = 1;
956
957 return WERR_OK;
958 }
959
960 struct dns_server_process_query_state {
961 struct tevent_context *ev;
962 struct dns_server *dns;
963 struct dns_name_question *question;
964
965 struct dns_res_rec *answers;
966 uint16_t ancount;
967 struct dns_res_rec *nsrecs;
968 uint16_t nscount;
969 struct dns_res_rec *additional;
970 uint16_t arcount;
971 struct forwarder_string *forwarders;
972 };
973
974 static void dns_server_process_query_got_auth(struct tevent_req *subreq);
975 static void dns_server_process_query_got_response(struct tevent_req *subreq);
976
977 struct tevent_req *dns_server_process_query_send(
978 TALLOC_CTX *mem_ctx, struct tevent_context *ev,
979 struct dns_server *dns, struct dns_request_state *req_state,
980 const struct dns_name_packet *in)
981 {
982 struct tevent_req *req, *subreq;
983 struct dns_server_process_query_state *state;
984 const char **forwarders = NULL;
985 unsigned int i;
986
987 req = tevent_req_create(mem_ctx, &state,
988 struct dns_server_process_query_state);
989 if (req == NULL) {
990 return NULL;
991 }
992 if (in->qdcount != 1) {
993 tevent_req_werror(req, DNS_ERR(FORMAT_ERROR));
994 return tevent_req_post(req, ev);
995 }
996
997 /* Windows returns NOT_IMPLEMENTED on this as well */
998 if (in->questions[0].question_class == DNS_QCLASS_NONE) {
999 tevent_req_werror(req, DNS_ERR(NOT_IMPLEMENTED));
1000 return tevent_req_post(req, ev);
1001 }
1002
1003 if (in->questions[0].question_type == DNS_QTYPE_TKEY) {
1004 WERROR err;
1005
1006 err = handle_tkey(dns, state, in, req_state,
1007 &state->answers, &state->ancount);
1008 if (tevent_req_werror(req, err)) {
1009 return tevent_req_post(req, ev);
1010 }
1011 tevent_req_done(req);
1012 return tevent_req_post(req, ev);
1013 }
1014
1015 state->dns = dns;
1016 state->ev = ev;
1017 state->question = &in->questions[0];
1018
1019 forwarders = lpcfg_dns_forwarder(dns->task->lp_ctx);
1020 for (i = 0; forwarders != NULL && forwarders[i] != NULL; i++) {
1021 struct forwarder_string *f = talloc_zero(state,
1022 struct forwarder_string);
1023 f->forwarder = forwarders[i];
1024 DLIST_ADD_END(state->forwarders, f);
1025 }
1026
1027 if (dns_authoritative_for_zone(dns, in->questions[0].name)) {
1028
1029 req_state->flags |= DNS_FLAG_AUTHORITATIVE;
1030
1031 /*
1032 * Initialize the response arrays, so that we can use
1033 * them as their own talloc contexts when doing the
1034 * realloc
1035 */
1036 state->answers = talloc_array(state, struct dns_res_rec, 0);
1037 if (tevent_req_nomem(state->answers, req)) {
1038 return tevent_req_post(req, ev);
1039 }
1040 state->nsrecs = talloc_array(state, struct dns_res_rec, 0);
1041 if (tevent_req_nomem(state->nsrecs, req)) {
1042 return tevent_req_post(req, ev);
1043 }
1044
1045 subreq = handle_authoritative_send(
1046 state, ev, dns, (forwarders == NULL ? NULL : forwarders[0]),
1047 &in->questions[0], &state->answers, &state->nsrecs);
1048 if (tevent_req_nomem(subreq, req)) {
1049 return tevent_req_post(req, ev);
1050 }
1051 tevent_req_set_callback(
1052 subreq, dns_server_process_query_got_auth, req);
1053 return req;
1054 }
1055
1056 if ((req_state->flags & DNS_FLAG_RECURSION_DESIRED) &&
1057 (req_state->flags & DNS_FLAG_RECURSION_AVAIL)) {
1058 DEBUG(5, ("Not authoritative for '%s', forwarding\n",
1059 in->questions[0].name));
1060
1061 subreq = ask_forwarder_send(state, ev, dns,
1062 (forwarders == NULL ? NULL : forwarders[0]),
1063 &in->questions[0]);
1064 if (tevent_req_nomem(subreq, req)) {
1065 return tevent_req_post(req, ev);
1066 }
1067 tevent_req_set_callback(
1068 subreq, dns_server_process_query_got_response, req);
1069 return req;
1070 }
1071
1072 tevent_req_werror(req, DNS_ERR(NAME_ERROR));
1073 return tevent_req_post(req, ev);
1074 }
1075
1076 static void dns_server_process_query_got_response(struct tevent_req *subreq)
1077 {
1078 struct tevent_req *req = tevent_req_callback_data(
1079 subreq, struct tevent_req);
1080 struct dns_server_process_query_state *state = tevent_req_data(
1081 req, struct dns_server_process_query_state);
1082 WERROR werr;
1083
1084 werr = ask_forwarder_recv(subreq, state,
1085 &state->answers, &state->ancount,
1086 &state->nsrecs, &state->nscount,
1087 &state->additional, &state->arcount);
1088 TALLOC_FREE(subreq);
1089
1090 /* If you get an error, attempt a different forwarder */
1091 if (!W_ERROR_IS_OK(werr)) {
1092 if (state->forwarders != NULL) {
1093 DLIST_REMOVE(state->forwarders, state->forwarders);
1094 }
1095
1096 /* If you have run out of forwarders, simply finish */
1097 if (state->forwarders == NULL) {
1098 tevent_req_werror(req, werr);
1099 return;
1100 }
1101
1102 DEBUG(5, ("DNS query returned %s, trying another forwarder.\n",
1103 win_errstr(werr)));
1104 subreq = ask_forwarder_send(state, state->ev, state->dns,
1105 state->forwarders->forwarder,
1106 state->question);
1107
1108 if (tevent_req_nomem(subreq, req)) {
1109 return;
1110 }
1111
1112 tevent_req_set_callback(subreq,
1113 dns_server_process_query_got_response,
1114 req);
1115 return;
1116 }
1117
1118 tevent_req_done(req);
1119 }
1120
1121 static void dns_server_process_query_got_auth(struct tevent_req *subreq)
1122 {
1123 struct tevent_req *req = tevent_req_callback_data(
1124 subreq, struct tevent_req);
1125 struct dns_server_process_query_state *state = tevent_req_data(
1126 req, struct dns_server_process_query_state);
1127 WERROR werr;
1128
1129 werr = handle_authoritative_recv(subreq);
1130 TALLOC_FREE(subreq);
1131
1132 /* If you get an error, attempt a different forwarder */
1133 if (!W_ERROR_IS_OK(werr)) {
1134 if (state->forwarders != NULL) {
1135 DLIST_REMOVE(state->forwarders, state->forwarders);
1136 }
1137
1138 /* If you have run out of forwarders, simply finish */
1139 if (state->forwarders == NULL) {
1140 tevent_req_werror(req, werr);
1141 return;
1142 }
1143
1144 DEBUG(5, ("Error: %s, trying a different forwarder.\n",
1145 win_errstr(werr)));
1146 subreq = handle_authoritative_send(state, state->ev, state->dns,
1147 state->forwarders->forwarder,
1148 state->question, &state->answers,
1149 &state->nsrecs);
1150
1151 if (tevent_req_nomem(subreq, req)) {
1152 return;
1153 }
1154
1155 tevent_req_set_callback(subreq,
1156 dns_server_process_query_got_auth,
1157 req);
1158 return;
1159 }
1160
1161 state->ancount = talloc_array_length(state->answers);
1162 state->nscount = talloc_array_length(state->nsrecs);
1163 state->arcount = talloc_array_length(state->additional);
1164
1165 tevent_req_done(req);
1166 }
1167
1168 WERROR dns_server_process_query_recv(
1169 struct tevent_req *req, TALLOC_CTX *mem_ctx,
1170 struct dns_res_rec **answers, uint16_t *ancount,
1171 struct dns_res_rec **nsrecs, uint16_t *nscount,
1172 struct dns_res_rec **additional, uint16_t *arcount)
1173 {
1174 struct dns_server_process_query_state *state = tevent_req_data(
1175 req, struct dns_server_process_query_state);
1176 WERROR err = WERR_OK;
1177
1178 if (tevent_req_is_werror(req, &err)) {
1179
1180 if ((!W_ERROR_EQUAL(err, DNS_ERR(NAME_ERROR))) &&
1181 (!W_ERROR_EQUAL(err, WERR_DNS_ERROR_NAME_DOES_NOT_EXIST))) {
1182 return err;
1183 }
1184 }
1185 *answers = talloc_move(mem_ctx, &state->answers);
1186 *ancount = state->ancount;
1187 *nsrecs = talloc_move(mem_ctx, &state->nsrecs);
1188 *nscount = state->nscount;
1189 *additional = talloc_move(mem_ctx, &state->additional);
1190 *arcount = state->arcount;
1191 return err;
1192 }
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