source: trunk/server/source4/dsdb/dns/dns_update.c

Last change on this file was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 17.8 KB
Line 
1/*
2 Unix SMB/CIFS mplementation.
3
4 DNS update service
5
6 Copyright (C) Andrew Tridgell 2009
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
23/*
24 this module auto-creates the named.conf.update file, which tells
25 bind9 what KRB5 principals it should accept for updates to our zone
26
27 It also uses the samba_dnsupdate script to auto-create the right DNS
28 names for ourselves as a DC in the domain, using TSIG-GSS
29 */
30
31#include "includes.h"
32#include "dsdb/samdb/samdb.h"
33#include "auth/auth.h"
34#include "smbd/service.h"
35#include "lib/messaging/irpc.h"
36#include "param/param.h"
37#include "system/filesys.h"
38#include "libcli/composite/composite.h"
39#include "libcli/security/dom_sid.h"
40#include "librpc/gen_ndr/ndr_irpc.h"
41
42struct dnsupdate_service {
43 struct task_server *task;
44 struct auth_session_info *system_session_info;
45 struct ldb_context *samdb;
46
47 /* status for periodic config file update */
48 struct {
49 uint32_t interval;
50 struct tevent_timer *te;
51 struct tevent_req *subreq;
52 NTSTATUS status;
53 } confupdate;
54
55 /* status for periodic DNS name check */
56 struct {
57 uint32_t interval;
58 struct tevent_timer *te;
59 struct tevent_req *subreq;
60 struct tevent_req *spnreq;
61 NTSTATUS status;
62 } nameupdate;
63};
64
65/*
66 called when rndc reload has finished
67 */
68static void dnsupdate_rndc_done(struct tevent_req *subreq)
69{
70 struct dnsupdate_service *service = tevent_req_callback_data(subreq,
71 struct dnsupdate_service);
72 int ret;
73 int sys_errno;
74
75 service->confupdate.subreq = NULL;
76
77 ret = samba_runcmd_recv(subreq, &sys_errno);
78 TALLOC_FREE(subreq);
79 if (ret != 0) {
80 service->confupdate.status = map_nt_error_from_unix(sys_errno);
81 } else {
82 service->confupdate.status = NT_STATUS_OK;
83 }
84
85 if (!NT_STATUS_IS_OK(service->confupdate.status)) {
86 DEBUG(0,(__location__ ": Failed rndc update - %s\n",
87 nt_errstr(service->confupdate.status)));
88 } else {
89 DEBUG(3,("Completed rndc reload OK\n"));
90 }
91}
92
93/*
94 called every 'dnsupdate:conf interval' seconds
95 */
96static void dnsupdate_rebuild(struct dnsupdate_service *service)
97{
98 int ret;
99 size_t size;
100 struct ldb_result *res;
101 const char *tmp_path, *path, *path_static;
102 char *static_policies;
103 int fd;
104 unsigned int i;
105 const char *attrs[] = { "sAMAccountName", NULL };
106 const char *realm = lpcfg_realm(service->task->lp_ctx);
107 TALLOC_CTX *tmp_ctx = talloc_new(service);
108 const char * const *rndc_command = lpcfg_rndc_command(service->task->lp_ctx);
109
110 /* abort any pending script run */
111 TALLOC_FREE(service->confupdate.subreq);
112
113 ret = ldb_search(service->samdb, tmp_ctx, &res, NULL, LDB_SCOPE_SUBTREE,
114 attrs, "(|(samaccountname=administrator)(&(primaryGroupID=%u)(objectClass=computer)))",
115 DOMAIN_RID_DCS);
116 if (ret != LDB_SUCCESS) {
117 DEBUG(0,(__location__ ": Unable to find DCs list - %s", ldb_errstring(service->samdb)));
118 talloc_free(tmp_ctx);
119 return;
120 }
121
122 path = lpcfg_parm_string(service->task->lp_ctx, NULL, "dnsupdate", "path");
123 if (path == NULL) {
124 path = private_path(tmp_ctx, service->task->lp_ctx, "named.conf.update");
125 }
126
127 path_static = lpcfg_parm_string(service->task->lp_ctx, NULL, "dnsupdate", "extra_static_grant_rules");
128 if (path_static == NULL) {
129 path_static = private_path(tmp_ctx, service->task->lp_ctx, "named.conf.update.static");
130 }
131
132 tmp_path = talloc_asprintf(tmp_ctx, "%s.tmp", path);
133 if (path == NULL || tmp_path == NULL || path_static == NULL ) {
134 DEBUG(0,(__location__ ": Unable to get paths\n"));
135 talloc_free(tmp_ctx);
136 return;
137 }
138
139 static_policies = file_load(path_static, &size, 0, tmp_ctx);
140
141 unlink(tmp_path);
142 fd = open(tmp_path, O_CREAT|O_TRUNC|O_WRONLY, 0444);
143 if (fd == -1) {
144 DEBUG(1,(__location__ ": Unable to open %s - %s\n", tmp_path, strerror(errno)));
145 talloc_free(tmp_ctx);
146 return;
147 }
148
149 dprintf(fd, "/* this file is auto-generated - do not edit */\n");
150 dprintf(fd, "update-policy {\n");
151 if( static_policies != NULL ) {
152 dprintf(fd, "/* Start of static entries */\n");
153 dprintf(fd, "%s\n",static_policies);
154 dprintf(fd, "/* End of static entries */\n");
155 }
156 dprintf(fd, "\tgrant %s ms-self * A AAAA;\n", realm);
157
158 for (i=0; i<res->count; i++) {
159 const char *acctname;
160 acctname = ldb_msg_find_attr_as_string(res->msgs[i],
161 "sAMAccountName", NULL);
162 if (!acctname) continue;
163 dprintf(fd, "\tgrant %s@%s wildcard * A AAAA SRV CNAME;\n",
164 acctname, realm);
165 }
166 dprintf(fd, "};\n");
167 close(fd);
168
169
170 if (NT_STATUS_IS_OK(service->confupdate.status) &&
171 file_compare(tmp_path, path) == true) {
172 unlink(tmp_path);
173 talloc_free(tmp_ctx);
174 return;
175 }
176
177 if (rename(tmp_path, path) != 0) {
178 DEBUG(0,(__location__ ": Failed to rename %s to %s - %s\n",
179 tmp_path, path, strerror(errno)));
180 talloc_free(tmp_ctx);
181 return;
182 }
183
184 DEBUG(2,("Loading new DNS update grant rules\n"));
185 service->confupdate.subreq = samba_runcmd_send(service,
186 service->task->event_ctx,
187 timeval_current_ofs(10, 0),
188 2, 0,
189 rndc_command,
190 "reload", NULL);
191 if (service->confupdate.subreq == NULL) {
192 DEBUG(0,(__location__ ": samba_runcmd_send() failed with no memory\n"));
193 talloc_free(tmp_ctx);
194 return;
195 }
196 tevent_req_set_callback(service->confupdate.subreq,
197 dnsupdate_rndc_done,
198 service);
199
200 talloc_free(tmp_ctx);
201}
202
203static NTSTATUS dnsupdate_confupdate_schedule(struct dnsupdate_service *service);
204
205/*
206 called every 'dnsupdate:conf interval' seconds
207 */
208static void dnsupdate_confupdate_handler_te(struct tevent_context *ev, struct tevent_timer *te,
209 struct timeval t, void *ptr)
210{
211 struct dnsupdate_service *service = talloc_get_type(ptr, struct dnsupdate_service);
212
213 dnsupdate_rebuild(service);
214 dnsupdate_confupdate_schedule(service);
215}
216
217
218static NTSTATUS dnsupdate_confupdate_schedule(struct dnsupdate_service *service)
219{
220 service->confupdate.te = tevent_add_timer(service->task->event_ctx, service,
221 timeval_current_ofs(service->confupdate.interval, 0),
222 dnsupdate_confupdate_handler_te, service);
223 NT_STATUS_HAVE_NO_MEMORY(service->confupdate.te);
224 return NT_STATUS_OK;
225}
226
227
228/*
229 called when dns update script has finished
230 */
231static void dnsupdate_nameupdate_done(struct tevent_req *subreq)
232{
233 struct dnsupdate_service *service = tevent_req_callback_data(subreq,
234 struct dnsupdate_service);
235 int ret;
236 int sys_errno;
237
238 service->nameupdate.subreq = NULL;
239
240 ret = samba_runcmd_recv(subreq, &sys_errno);
241 TALLOC_FREE(subreq);
242 if (ret != 0) {
243 service->nameupdate.status = map_nt_error_from_unix(sys_errno);
244 } else {
245 service->nameupdate.status = NT_STATUS_OK;
246 }
247
248 if (!NT_STATUS_IS_OK(service->nameupdate.status)) {
249 DEBUG(0,(__location__ ": Failed DNS update - %s\n",
250 nt_errstr(service->nameupdate.status)));
251 } else {
252 DEBUG(3,("Completed DNS update check OK\n"));
253 }
254}
255
256
257/*
258 called when spn update script has finished
259 */
260static void dnsupdate_spnupdate_done(struct tevent_req *subreq)
261{
262 struct dnsupdate_service *service = tevent_req_callback_data(subreq,
263 struct dnsupdate_service);
264 int ret;
265 int sys_errno;
266
267 service->nameupdate.spnreq = NULL;
268
269 ret = samba_runcmd_recv(subreq, &sys_errno);
270 TALLOC_FREE(subreq);
271 if (ret != 0) {
272 service->nameupdate.status = map_nt_error_from_unix(sys_errno);
273 } else {
274 service->nameupdate.status = NT_STATUS_OK;
275 }
276
277 if (!NT_STATUS_IS_OK(service->nameupdate.status)) {
278 DEBUG(0,(__location__ ": Failed SPN update - %s\n",
279 nt_errstr(service->nameupdate.status)));
280 } else {
281 DEBUG(3,("Completed SPN update check OK\n"));
282 }
283}
284
285/*
286 called every 'dnsupdate:name interval' seconds
287 */
288static void dnsupdate_check_names(struct dnsupdate_service *service)
289{
290 const char * const *dns_update_command = lpcfg_dns_update_command(service->task->lp_ctx);
291 const char * const *spn_update_command = lpcfg_spn_update_command(service->task->lp_ctx);
292
293 /* kill any existing child */
294 TALLOC_FREE(service->nameupdate.subreq);
295
296 DEBUG(3,("Calling DNS name update script\n"));
297 service->nameupdate.subreq = samba_runcmd_send(service,
298 service->task->event_ctx,
299 timeval_current_ofs(20, 0),
300 2, 0,
301 dns_update_command,
302 NULL);
303 if (service->nameupdate.subreq == NULL) {
304 DEBUG(0,(__location__ ": samba_runcmd_send() failed with no memory\n"));
305 return;
306 }
307 tevent_req_set_callback(service->nameupdate.subreq,
308 dnsupdate_nameupdate_done,
309 service);
310
311 DEBUG(3,("Calling SPN name update script\n"));
312 service->nameupdate.spnreq = samba_runcmd_send(service,
313 service->task->event_ctx,
314 timeval_current_ofs(20, 0),
315 2, 0,
316 spn_update_command,
317 NULL);
318 if (service->nameupdate.spnreq == NULL) {
319 DEBUG(0,(__location__ ": samba_runcmd_send() failed with no memory\n"));
320 return;
321 }
322 tevent_req_set_callback(service->nameupdate.spnreq,
323 dnsupdate_spnupdate_done,
324 service);
325}
326
327static NTSTATUS dnsupdate_nameupdate_schedule(struct dnsupdate_service *service);
328
329/*
330 called every 'dnsupdate:name interval' seconds
331 */
332static void dnsupdate_nameupdate_handler_te(struct tevent_context *ev, struct tevent_timer *te,
333 struct timeval t, void *ptr)
334{
335 struct dnsupdate_service *service = talloc_get_type(ptr, struct dnsupdate_service);
336
337 dnsupdate_check_names(service);
338 dnsupdate_nameupdate_schedule(service);
339}
340
341
342static NTSTATUS dnsupdate_nameupdate_schedule(struct dnsupdate_service *service)
343{
344 service->nameupdate.te = tevent_add_timer(service->task->event_ctx, service,
345 timeval_current_ofs(service->nameupdate.interval, 0),
346 dnsupdate_nameupdate_handler_te, service);
347 NT_STATUS_HAVE_NO_MEMORY(service->nameupdate.te);
348 return NT_STATUS_OK;
349}
350
351
352struct dnsupdate_RODC_state {
353 struct irpc_message *msg;
354 struct dnsupdate_RODC *r;
355 char *tmp_path;
356 int fd;
357};
358
359static int dnsupdate_RODC_destructor(struct dnsupdate_RODC_state *st)
360{
361 if (st->fd != -1) {
362 close(st->fd);
363 }
364 unlink(st->tmp_path);
365 return 0;
366}
367
368/*
369 called when the DNS update has completed
370 */
371static void dnsupdate_RODC_callback(struct tevent_req *req)
372{
373 struct dnsupdate_RODC_state *st =
374 tevent_req_callback_data(req,
375 struct dnsupdate_RODC_state);
376 int sys_errno;
377 int i, ret;
378
379 ret = samba_runcmd_recv(req, &sys_errno);
380 talloc_free(req);
381 if (ret != 0) {
382 st->r->out.result = map_nt_error_from_unix(sys_errno);
383 DEBUG(2,(__location__ ": RODC DNS Update failed: %s\n", nt_errstr(st->r->out.result)));
384 } else {
385 st->r->out.result = NT_STATUS_OK;
386 DEBUG(3,(__location__ ": RODC DNS Update OK\n"));
387 }
388
389 for (i=0; i<st->r->in.dns_names->count; i++) {
390 st->r->out.dns_names->names[i].status = NT_STATUS_V(st->r->out.result);
391 }
392
393 irpc_send_reply(st->msg, NT_STATUS_OK);
394}
395
396
397/**
398 * Called when we get a RODC DNS update request from the netlogon
399 * rpc server
400 */
401static NTSTATUS dnsupdate_dnsupdate_RODC(struct irpc_message *msg,
402 struct dnsupdate_RODC *r)
403{
404 struct dnsupdate_service *s = talloc_get_type(msg->private_data,
405 struct dnsupdate_service);
406 const char * const *dns_update_command = lpcfg_dns_update_command(s->task->lp_ctx);
407 struct dnsupdate_RODC_state *st;
408 struct tevent_req *req;
409 int i, ret;
410 struct GUID ntds_guid;
411 const char *site, *dnsdomain, *dnsforest, *ntdsguid, *hostname;
412 struct ldb_dn *sid_dn;
413 const char *attrs[] = { "dNSHostName", NULL };
414 struct ldb_result *res;
415
416 st = talloc_zero(msg, struct dnsupdate_RODC_state);
417 if (!st) {
418 r->out.result = NT_STATUS_NO_MEMORY;
419 return NT_STATUS_OK;
420 }
421
422 st->r = r;
423 st->msg = msg;
424
425 st->tmp_path = smbd_tmp_path(st, s->task->lp_ctx, "rodcdns.XXXXXX");
426 if (!st->tmp_path) {
427 talloc_free(st);
428 r->out.result = NT_STATUS_NO_MEMORY;
429 return NT_STATUS_OK;
430 }
431
432 st->fd = mkstemp(st->tmp_path);
433 if (st->fd == -1) {
434 DEBUG(0,("Unable to create a temporary file for RODC dnsupdate\n"));
435 talloc_free(st);
436 r->out.result = NT_STATUS_INTERNAL_DB_CORRUPTION;
437 return NT_STATUS_OK;
438 }
439
440 talloc_set_destructor(st, dnsupdate_RODC_destructor);
441
442 sid_dn = ldb_dn_new_fmt(st, s->samdb, "<SID=%s>", dom_sid_string(st, r->in.dom_sid));
443 if (!sid_dn) {
444 talloc_free(st);
445 r->out.result = NT_STATUS_NO_MEMORY;
446 return NT_STATUS_OK;
447 }
448
449 /* work out the site */
450 ret = samdb_find_site_for_computer(s->samdb, st, sid_dn, &site);
451 if (ret != LDB_SUCCESS) {
452 DEBUG(2, (__location__ ": Unable to find site for computer %s\n",
453 ldb_dn_get_linearized(sid_dn)));
454 talloc_free(st);
455 r->out.result = NT_STATUS_NO_SUCH_USER;
456 return NT_STATUS_OK;
457 }
458
459 /* work out the ntdsguid */
460 ret = samdb_find_ntdsguid_for_computer(s->samdb, sid_dn, &ntds_guid);
461 ntdsguid = GUID_string(st, &ntds_guid);
462 if (ret != LDB_SUCCESS || !ntdsguid) {
463 DEBUG(2, (__location__ ": Unable to find NTDS GUID for computer %s\n",
464 ldb_dn_get_linearized(sid_dn)));
465 talloc_free(st);
466 r->out.result = NT_STATUS_NO_SUCH_USER;
467 return NT_STATUS_OK;
468 }
469
470
471 /* find dnsdomain and dnsforest */
472 dnsdomain = lpcfg_realm(s->task->lp_ctx);
473 dnsforest = dnsdomain;
474
475 /* find the hostname */
476 ret = dsdb_search_dn(s->samdb, st, &res, sid_dn, attrs, 0);
477 if (ret == LDB_SUCCESS) {
478 hostname = ldb_msg_find_attr_as_string(res->msgs[0], "dNSHostName", NULL);
479 }
480 if (ret != LDB_SUCCESS || !hostname) {
481 DEBUG(2, (__location__ ": Unable to find NTDS GUID for computer %s\n",
482 ldb_dn_get_linearized(sid_dn)));
483 talloc_free(st);
484 r->out.result = NT_STATUS_NO_SUCH_USER;
485 return NT_STATUS_OK;
486 }
487
488
489 for (i=0; i<st->r->in.dns_names->count; i++) {
490 struct NL_DNS_NAME_INFO *n = &r->in.dns_names->names[i];
491 switch (n->type) {
492 case NlDnsLdapAtSite:
493 dprintf(st->fd, "SRV _ldap._tcp.%s._sites.%s. %s %u\n",
494 site, dnsdomain, hostname, n->port);
495 break;
496 case NlDnsGcAtSite:
497 dprintf(st->fd, "SRV _ldap._tcp.%s._sites.gc._msdcs.%s. %s %u\n",
498 site, dnsdomain, hostname, n->port);
499 break;
500 case NlDnsDsaCname:
501 dprintf(st->fd, "CNAME %s._msdcs.%s. %s\n",
502 ntdsguid, dnsforest, hostname);
503 break;
504 case NlDnsKdcAtSite:
505 dprintf(st->fd, "SRV _kerberos._tcp.%s._sites.dc._msdcs.%s. %s %u\n",
506 site, dnsdomain, hostname, n->port);
507 break;
508 case NlDnsDcAtSite:
509 dprintf(st->fd, "SRV _ldap._tcp.%s._sites.dc._msdcs.%s. %s %u\n",
510 site, dnsdomain, hostname, n->port);
511 break;
512 case NlDnsRfc1510KdcAtSite:
513 dprintf(st->fd, "SRV _kerberos._tcp.%s._sites.%s. %s %u\n",
514 site, dnsdomain, hostname, n->port);
515 break;
516 case NlDnsGenericGcAtSite:
517 dprintf(st->fd, "SRV _gc._tcp.%s._sites.%s. %s %u\n",
518 site, dnsforest, hostname, n->port);
519 break;
520 }
521 }
522
523 close(st->fd);
524 st->fd = -1;
525
526 DEBUG(3,("Calling RODC DNS name update script %s\n", st->tmp_path));
527 req = samba_runcmd_send(st,
528 s->task->event_ctx,
529 timeval_current_ofs(20, 0),
530 2, 0,
531 dns_update_command,
532 "--update-list",
533 st->tmp_path,
534 NULL);
535 NT_STATUS_HAVE_NO_MEMORY(req);
536
537 /* setup the callback */
538 tevent_req_set_callback(req, dnsupdate_RODC_callback, st);
539
540 msg->defer_reply = true;
541
542 return NT_STATUS_OK;
543}
544
545/*
546 startup the dns update task
547*/
548static void dnsupdate_task_init(struct task_server *task)
549{
550 NTSTATUS status;
551 struct dnsupdate_service *service;
552
553 if (lpcfg_server_role(task->lp_ctx) != ROLE_DOMAIN_CONTROLLER) {
554 /* not useful for non-DC */
555 return;
556 }
557
558 task_server_set_title(task, "task[dnsupdate]");
559
560 service = talloc_zero(task, struct dnsupdate_service);
561 if (!service) {
562 task_server_terminate(task, "dnsupdate_task_init: out of memory", true);
563 return;
564 }
565 service->task = task;
566 task->private_data = service;
567
568 service->system_session_info = system_session(service->task->lp_ctx);
569 if (!service->system_session_info) {
570 task_server_terminate(task,
571 "dnsupdate: Failed to obtain server credentials\n",
572 true);
573 return;
574 }
575
576 service->samdb = samdb_connect(service, service->task->event_ctx, task->lp_ctx,
577 service->system_session_info, 0);
578 if (!service->samdb) {
579 task_server_terminate(task, "dnsupdate: Failed to connect to local samdb\n",
580 true);
581 return;
582 }
583
584 service->confupdate.interval = lpcfg_parm_int(task->lp_ctx, NULL,
585 "dnsupdate", "config interval", 60); /* in seconds */
586
587 service->nameupdate.interval = lpcfg_parm_int(task->lp_ctx, NULL,
588 "dnsupdate", "name interval", 600); /* in seconds */
589
590 dnsupdate_rebuild(service);
591 status = dnsupdate_confupdate_schedule(service);
592 if (!NT_STATUS_IS_OK(status)) {
593 task_server_terminate(task, talloc_asprintf(task,
594 "dnsupdate: Failed to confupdate schedule: %s\n",
595 nt_errstr(status)), true);
596 return;
597 }
598
599 dnsupdate_check_names(service);
600 status = dnsupdate_nameupdate_schedule(service);
601 if (!NT_STATUS_IS_OK(status)) {
602 task_server_terminate(task, talloc_asprintf(task,
603 "dnsupdate: Failed to nameupdate schedule: %s\n",
604 nt_errstr(status)), true);
605 return;
606 }
607
608 irpc_add_name(task->msg_ctx, "dnsupdate");
609
610 IRPC_REGISTER(task->msg_ctx, irpc, DNSUPDATE_RODC,
611 dnsupdate_dnsupdate_RODC, service);
612
613 /* create the intial file */
614 dnsupdate_rebuild(service);
615
616}
617
618/*
619 register ourselves as a available server
620*/
621NTSTATUS server_service_dnsupdate_init(void)
622{
623 return register_server_service("dnsupdate", dnsupdate_task_init);
624}
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