summaryrefslogtreecommitdiff
path: root/source4/dsdb/samdb/ldb_modules/ridalloc.c
blob: 2dd4c563c8e2fbdcb5c2baa094186aa90c537d15 (plain)
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
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
/*
   RID allocation helper functions

   Copyright (C) Andrew Bartlett 2010
   Copyright (C) Andrew Tridgell 2010

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

/*
 *  Name: ldb
 *
 *  Component: RID allocation logic
 *
 *  Description: manage RID Set and RID Manager objects
 *
 */

#include "includes.h"
#include "ldb_module.h"
#include "dsdb/samdb/samdb.h"
#include "dsdb/samdb/ldb_modules/util.h"
#include "lib/messaging/irpc.h"
#include "param/param.h"
#include "librpc/gen_ndr/ndr_misc.h"

/*
  Note: the RID allocation attributes in AD are very badly named. Here
  is what we think they really do:

  in RID Set object:
    - rIDPreviousAllocationPool: the pool which a DC is currently
      pulling RIDs from. Managed by client DC

    - rIDAllocationPool: the pool that the DC will switch to next,
      when rIDPreviousAllocationPool is exhausted. Managed by RID Manager.

    - rIDNextRID: the last RID allocated by this DC. Managed by client DC

  in RID Manager object:
    - rIDAvailablePool: the pool where the RID Manager gets new rID
      pools from when it gets a EXOP_RID_ALLOC getncchanges call (or
      locally when the DC is the RID Manager)
 */


/*
  make a IRPC call to the drepl task to ask it to get the RID
  Manager to give us another RID pool.

  This function just sends the message to the drepl task then
  returns immediately. It should be called well before we
  completely run out of RIDs
 */
static void ridalloc_poke_rid_manager(struct ldb_module *module)
{
	struct messaging_context *msg;
	struct server_id *server;
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	struct loadparm_context *lp_ctx =
		(struct loadparm_context *)ldb_get_opaque(ldb, "loadparm");
	TALLOC_CTX *tmp_ctx = talloc_new(module);

	msg = messaging_client_init(tmp_ctx, lp_messaging_path(tmp_ctx, lp_ctx),
				    ldb_get_event_context(ldb));
	if (!msg) {
		DEBUG(3,(__location__ ": Failed to create messaging context\n"));
		talloc_free(tmp_ctx);
		return;
	}

	server = irpc_servers_byname(msg, msg, "dreplsrv");
	if (!server) {
		/* this means the drepl service is not running */
		talloc_free(tmp_ctx);
		return;
	}

	messaging_send(msg, server[0], MSG_DREPL_ALLOCATE_RID, NULL);

	/* we don't care if the message got through */
	talloc_free(tmp_ctx);
}


static const char * const ridalloc_ridset_attrs[] = {
	"rIDAllocationPool",
	"rIDPreviousAllocationPool",
	"rIDNextRID",
	"rIDUsedPool",
	NULL
};

struct ridalloc_ridset_values {
	uint64_t alloc_pool;
	uint64_t prev_pool;
	uint32_t next_rid;
	uint32_t used_pool;
};

static void ridalloc_get_ridset_values(struct ldb_message *msg, struct ridalloc_ridset_values *v)
{
	v->alloc_pool = ldb_msg_find_attr_as_uint64(msg, "rIDAllocationPool", UINT64_MAX);
	v->prev_pool = ldb_msg_find_attr_as_uint64(msg, "rIDPreviousAllocationPool", UINT64_MAX);
	v->next_rid = ldb_msg_find_attr_as_uint(msg, "rIDNextRID", UINT32_MAX);
	v->used_pool = ldb_msg_find_attr_as_uint(msg, "rIDUsedPool", UINT32_MAX);
}

static int ridalloc_set_ridset_values(struct ldb_module *module,
				      struct ldb_message *msg,
				      const struct ridalloc_ridset_values *o,
				      const struct ridalloc_ridset_values *n)
{
	const uint32_t *o32, *n32;
	const uint64_t *o64, *n64;
	int ret;

#define SETUP_PTRS(field, optr, nptr, max) do { \
	optr = &o->field; \
	nptr = &n->field; \
	if (o->field == max) { \
		optr = NULL; \
	} \
	if (n->field == max) { \
		nptr = NULL; \
	} \
	if (o->field == n->field) { \
		optr = NULL; \
		nptr = NULL; \
	} \
} while(0)

	SETUP_PTRS(alloc_pool, o64, n64, UINT64_MAX);
	ret = dsdb_msg_constrainted_update_uint64(module, msg,
						  "rIDAllocationPool",
						  o64, n64);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	SETUP_PTRS(prev_pool, o64, n64, UINT64_MAX);
	ret = dsdb_msg_constrainted_update_uint64(module, msg,
						  "rIDPreviousAllocationPool",
						  o64, n64);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	SETUP_PTRS(next_rid, o32, n32, UINT32_MAX);
	ret = dsdb_msg_constrainted_update_uint32(module, msg,
						  "rIDNextRID",
						  o32, n32);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	SETUP_PTRS(used_pool, o32, n32, UINT32_MAX);
	ret = dsdb_msg_constrainted_update_uint32(module, msg,
						  "rIDUsedPool",
						  o32, n32);
	if (ret != LDB_SUCCESS) {
		return ret;
	}
#undef SETUP_PTRS

	return LDB_SUCCESS;
}

/*
  allocate a new range of RIDs in the RID Manager object
 */
static int ridalloc_rid_manager_allocate(struct ldb_module *module, struct ldb_dn *rid_manager_dn, uint64_t *new_pool)
{
	int ret;
	TALLOC_CTX *tmp_ctx = talloc_new(module);
	const char *attrs[] = { "rIDAvailablePool", NULL };
	uint64_t rid_pool, new_rid_pool, dc_pool;
	uint32_t rid_pool_lo, rid_pool_hi;
	struct ldb_result *res;
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	const unsigned alloc_size = 500;

	ret = dsdb_module_search_dn(module, tmp_ctx, &res, rid_manager_dn,
	                            attrs, DSDB_FLAG_NEXT_MODULE);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find rIDAvailablePool in %s - %s",
				       ldb_dn_get_linearized(rid_manager_dn), ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	rid_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDAvailablePool", 0);
	rid_pool_lo = rid_pool & 0xFFFFFFFF;
	rid_pool_hi = rid_pool >> 32;
	if (rid_pool_lo >= rid_pool_hi) {
		ldb_asprintf_errstring(ldb, "Out of RIDs in RID Manager - rIDAvailablePool is %u-%u",
				       rid_pool_lo, rid_pool_hi);
		talloc_free(tmp_ctx);
		return ret;
	}

	/* lower part of new pool is the low part of the rIDAvailablePool */
	dc_pool = rid_pool_lo;

	/* allocate 500 RIDs to this DC */
	rid_pool_lo = MIN(rid_pool_hi, rid_pool_lo + alloc_size);

	/* work out upper part of new pool */
	dc_pool |= (((uint64_t)rid_pool_lo-1)<<32);

	/* and new rIDAvailablePool value */
	new_rid_pool = rid_pool_lo | (((uint64_t)rid_pool_hi)<<32);

	ret = dsdb_module_constrainted_update_uint64(module, rid_manager_dn, "rIDAvailablePool",
						     &rid_pool, &new_rid_pool);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to update rIDAvailablePool - %s",
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	(*new_pool) = dc_pool;
	talloc_free(tmp_ctx);
	return LDB_SUCCESS;
}

/*
  create a RID Set object for the specified DC
 */
static int ridalloc_create_rid_set_ntds(struct ldb_module *module, TALLOC_CTX *mem_ctx,
					struct ldb_dn *rid_manager_dn,
					struct ldb_dn *ntds_dn, struct ldb_dn **dn)
{
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	struct ldb_dn *server_dn, *machine_dn, *rid_set_dn;
	int ret;
	struct ldb_message *msg;
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	static const struct ridalloc_ridset_values o = {
		.alloc_pool	= UINT64_MAX,
		.prev_pool	= UINT64_MAX,
		.next_rid	= UINT32_MAX,
		.used_pool	= UINT32_MAX,
	};
	struct ridalloc_ridset_values n = {
		.alloc_pool	= 0,
		.prev_pool	= 0,
		.next_rid	= 0,
		.used_pool	= 0,
	};

	/*
	  steps:

	  find the machine object for the DC
	  construct the RID Set DN
	  load rIDAvailablePool to find next available set
	  modify RID Manager object to update rIDAvailablePool
	  add the RID Set object
	  link to the RID Set object in machine object
	 */

	server_dn = ldb_dn_get_parent(tmp_ctx, ntds_dn);
	if (!server_dn) {
		talloc_free(tmp_ctx);
		return ldb_module_oom(module);
	}

	ret = dsdb_module_reference_dn(module, tmp_ctx, server_dn, "serverReference", &machine_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find serverReference in %s - %s",
				       ldb_dn_get_linearized(server_dn), ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	rid_set_dn = ldb_dn_copy(tmp_ctx, machine_dn);
	if (rid_set_dn == NULL) {
		talloc_free(tmp_ctx);
		return ldb_module_oom(module);
	}

	if (! ldb_dn_add_child_fmt(rid_set_dn, "CN=RID Set")) {
		talloc_free(tmp_ctx);
		return ldb_module_oom(module);
	}

	/* grab a pool from the RID Manager object */
	ret = ridalloc_rid_manager_allocate(module, rid_manager_dn, &n.alloc_pool);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	/* create the RID Set object */
	msg = ldb_msg_new(tmp_ctx);
	msg->dn = rid_set_dn;

	ret = ldb_msg_add_string(msg, "objectClass", "rIDSet");
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	ret = ridalloc_set_ridset_values(module, msg, &o, &n);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	/* we need this to go all the way to the top of the module
	 * stack, as we need all the extra attributes added (including
	 * complex ones like ntsecuritydescriptor) */
	ret = dsdb_module_add(module, msg, DSDB_FLAG_TOP_MODULE | DSDB_MODIFY_RELAX);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to add RID Set %s - %s",
				       ldb_dn_get_linearized(msg->dn),
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	/* add the rIDSetReferences link */
	msg = ldb_msg_new(tmp_ctx);
	msg->dn = machine_dn;

	ret = ldb_msg_add_string(msg, "rIDSetReferences", ldb_dn_get_linearized(rid_set_dn));
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}
	msg->elements[0].flags = LDB_FLAG_MOD_ADD;

	ret = dsdb_module_modify(module, msg, DSDB_FLAG_NEXT_MODULE);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to add rIDSetReferences to %s - %s",
				       ldb_dn_get_linearized(msg->dn),
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	(*dn) = talloc_steal(mem_ctx, rid_set_dn);

	talloc_free(tmp_ctx);
	return LDB_SUCCESS;
}


/*
  create a RID Set object for this DC
 */
static int ridalloc_create_own_rid_set(struct ldb_module *module, TALLOC_CTX *mem_ctx,
				       struct ldb_dn **dn)
{
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	struct ldb_dn *rid_manager_dn, *fsmo_role_dn;
	int ret;
	struct ldb_context *ldb = ldb_module_get_ctx(module);

	/* work out who is the RID Manager */
	ret = dsdb_module_rid_manager_dn(module, tmp_ctx, &rid_manager_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find RID Manager object - %s",
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	/* find the DN of the RID Manager */
	ret = dsdb_module_reference_dn(module, tmp_ctx, rid_manager_dn, "fSMORoleOwner", &fsmo_role_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find fSMORoleOwner in RID Manager object - %s",
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	if (ldb_dn_compare(samdb_ntds_settings_dn(ldb), fsmo_role_dn) != 0) {
		ridalloc_poke_rid_manager(module);
		ldb_asprintf_errstring(ldb, "Remote RID Set allocation needs refresh");
		talloc_free(tmp_ctx);
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	ret = ridalloc_create_rid_set_ntds(module, mem_ctx, rid_manager_dn, fsmo_role_dn, dn);
	talloc_free(tmp_ctx);
	return ret;
}

/*
  refresh a RID Set object for the specified DC
  also returns the first RID for the new pool
 */
static int ridalloc_refresh_rid_set_ntds(struct ldb_module *module,
					 struct ldb_dn *rid_manager_dn,
					 struct ldb_dn *ntds_dn, uint64_t *new_pool)
{
	TALLOC_CTX *tmp_ctx = talloc_new(module);
	struct ldb_dn *server_dn, *machine_dn, *rid_set_dn;
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	int ret;

	/* grab a pool from the RID Manager object */
	ret = ridalloc_rid_manager_allocate(module, rid_manager_dn, new_pool);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	server_dn = ldb_dn_get_parent(tmp_ctx, ntds_dn);
	if (!server_dn) {
		talloc_free(tmp_ctx);
		return ldb_module_oom(module);
	}

	ret = dsdb_module_reference_dn(module, tmp_ctx, server_dn, "serverReference", &machine_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find serverReference in %s - %s",
				       ldb_dn_get_linearized(server_dn), ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	ret = dsdb_module_reference_dn(module, tmp_ctx, machine_dn, "rIDSetReferences", &rid_set_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find rIDSetReferences in %s - %s",
				       ldb_dn_get_linearized(machine_dn), ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	ret = dsdb_module_set_integer(module, rid_set_dn, "rIDAllocationPool", *new_pool);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to modify RID Set object %s - %s",
				       ldb_dn_get_linearized(rid_set_dn), ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	talloc_free(tmp_ctx);
	return LDB_SUCCESS;
}


/*
  get a new RID pool for ourselves
  also returns the first rid for the new pool
 */
static int ridalloc_new_own_pool(struct ldb_module *module, uint64_t *new_pool)
{
	TALLOC_CTX *tmp_ctx = talloc_new(module);
	struct ldb_dn *rid_manager_dn, *fsmo_role_dn;
	int ret;
	struct ldb_context *ldb = ldb_module_get_ctx(module);

	/* work out who is the RID Manager */
	ret = dsdb_module_rid_manager_dn(module, tmp_ctx, &rid_manager_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find RID Manager object - %s",
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	/* find the DN of the RID Manager */
	ret = dsdb_module_reference_dn(module, tmp_ctx, rid_manager_dn, "fSMORoleOwner", &fsmo_role_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find fSMORoleOwner in RID Manager object - %s",
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	if (ldb_dn_compare(samdb_ntds_settings_dn(ldb), fsmo_role_dn) != 0) {
		ridalloc_poke_rid_manager(module);
		ldb_asprintf_errstring(ldb, "Remote RID Set allocation needs refresh");
		talloc_free(tmp_ctx);
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	/* grab a pool from the RID Manager object */
	ret = ridalloc_rid_manager_allocate(module, rid_manager_dn, new_pool);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	talloc_free(tmp_ctx);
	return ret;
}


/* allocate a RID using our RID Set
   If we run out of RIDs then allocate a new pool
   either locally or by contacting the RID Manager
*/
int ridalloc_allocate_rid(struct ldb_module *module, uint32_t *rid)
{
	struct ldb_context *ldb;
	int ret;
	struct ldb_dn *rid_set_dn;
	struct ldb_result *res;
	struct ldb_message *msg;
	struct ridalloc_ridset_values oridset;
	struct ridalloc_ridset_values nridset;
	uint32_t prev_pool_lo, prev_pool_hi;
	TALLOC_CTX *tmp_ctx = talloc_new(module);

	(*rid) = 0;
	ldb = ldb_module_get_ctx(module);

	ret = samdb_rid_set_dn(ldb, tmp_ctx, &rid_set_dn);
	if (ret == LDB_ERR_NO_SUCH_ATTRIBUTE) {
		ret = ridalloc_create_own_rid_set(module, tmp_ctx, &rid_set_dn);
	}
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, __location__ ": No RID Set DN - %s",
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	ret = dsdb_module_search_dn(module, tmp_ctx, &res, rid_set_dn,
				    ridalloc_ridset_attrs, DSDB_FLAG_NEXT_MODULE);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, __location__ ": No RID Set %s",
				       ldb_dn_get_linearized(rid_set_dn));
		talloc_free(tmp_ctx);
		return ret;
	}

	ridalloc_get_ridset_values(res->msgs[0], &oridset);
	if (oridset.alloc_pool == UINT64_MAX) {
		ldb_asprintf_errstring(ldb, __location__ ": Bad RID Set %s",
				       ldb_dn_get_linearized(rid_set_dn));
		talloc_free(tmp_ctx);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	nridset = oridset;

	/*
	 * If we never used a pool, setup out first pool
	 */
	if (nridset.prev_pool == UINT64_MAX ||
	    nridset.next_rid == UINT32_MAX) {
		nridset.prev_pool = nridset.alloc_pool;
		nridset.next_rid = nridset.prev_pool & 0xFFFFFFFF;
	}

	/*
	 * Now check if our current pool is still usable
	 */
	nridset.next_rid += 1;
	prev_pool_lo = nridset.prev_pool & 0xFFFFFFFF;
	prev_pool_hi = nridset.prev_pool >> 32;
	if (nridset.next_rid > prev_pool_hi) {
		/*
		 * We need a new pool, check if we already have a new one
		 * Otherwise we need to get a new pool.
		 */
		if (nridset.alloc_pool == nridset.prev_pool) {
			/*
			 * if we are the RID Manager,
			 * we can get a new pool localy.
			 * Otherwise we fail the operation and
			 * ask async for a new pool.
			 */
			ret = ridalloc_new_own_pool(module, &nridset.alloc_pool);
			if (ret == LDB_ERR_UNWILLING_TO_PERFORM) {
				ridalloc_poke_rid_manager(module);
				talloc_free(tmp_ctx);
				return ret;
			}
			if (ret != LDB_SUCCESS) {
				talloc_free(tmp_ctx);
				return ret;
			}
		}

		/*
		 * increment the rIDUsedPool attribute
		 *
		 * Note: w2k8r2 doesn't update this attribute,
		 *       at least if it's itself the rid master.
		 */
		nridset.used_pool += 1;

		/* now use the new pool */
		nridset.prev_pool = nridset.alloc_pool;
		prev_pool_lo = nridset.prev_pool & 0xFFFFFFFF;
		prev_pool_hi = nridset.prev_pool >> 32;
		nridset.next_rid = prev_pool_lo;
	}

	if (nridset.next_rid < prev_pool_lo || nridset.next_rid > prev_pool_hi) {
		ldb_asprintf_errstring(ldb, __location__ ": Bad rid chosen %u from range %u-%u",
				       (unsigned)nridset.next_rid,
				       (unsigned)prev_pool_lo,
				       (unsigned)prev_pool_hi);
		talloc_free(tmp_ctx);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/*
	 * if we are half-exhausted then try to get a new pool.
	 */
	if (nridset.next_rid > (prev_pool_hi + prev_pool_lo)/2) {
		/*
		 * if we are the RID Manager,
		 * we can get a new pool localy.
		 * Otherwise we fail the operation and
		 * ask async for a new pool.
		 */
		ret = ridalloc_new_own_pool(module, &nridset.alloc_pool);
		if (ret == LDB_ERR_UNWILLING_TO_PERFORM) {
			ridalloc_poke_rid_manager(module);
			ret = LDB_SUCCESS;
		}
		if (ret != LDB_SUCCESS) {
			talloc_free(tmp_ctx);
			return ret;
		}
	}

	/*
	 * update the values
	 */
	msg = ldb_msg_new(tmp_ctx);
	if (msg == NULL) {
		return ldb_module_oom(module);
	}
	msg->dn = rid_set_dn;

	ret = ridalloc_set_ridset_values(module, msg,
					 &oridset, &nridset);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	ret = dsdb_module_modify(module, msg, DSDB_FLAG_NEXT_MODULE);
	if (ret != LDB_SUCCESS) {
		talloc_free(tmp_ctx);
		return ret;
	}

	talloc_free(tmp_ctx);
	*rid = nridset.next_rid;
	return LDB_SUCCESS;
}


/*
  called by DSDB_EXTENDED_ALLOCATE_RID_POOL extended operation in samldb
 */
int ridalloc_allocate_rid_pool_fsmo(struct ldb_module *module, struct dsdb_fsmo_extended_op *exop)
{
	struct ldb_dn *ntds_dn, *server_dn, *machine_dn, *rid_set_dn;
	struct ldb_dn *rid_manager_dn;
	TALLOC_CTX *tmp_ctx = talloc_new(module);
	int ret;
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	uint64_t new_pool;

	ret = dsdb_module_dn_by_guid(module, tmp_ctx, &exop->destination_dsa_guid, &ntds_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, __location__ ": Unable to find NTDS object for guid %s - %s\n",
				       GUID_string(tmp_ctx, &exop->destination_dsa_guid), ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	server_dn = ldb_dn_get_parent(tmp_ctx, ntds_dn);
	if (!server_dn) {
		talloc_free(tmp_ctx);
		return ldb_module_oom(module);
	}

	ret = dsdb_module_reference_dn(module, tmp_ctx, server_dn, "serverReference", &machine_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, __location__ ": Failed to find serverReference in %s - %s",
				       ldb_dn_get_linearized(server_dn), ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}


	ret = dsdb_module_rid_manager_dn(module, tmp_ctx, &rid_manager_dn);
	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, __location__ ": Failed to find RID Manager object - %s",
				       ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	ret = dsdb_module_reference_dn(module, tmp_ctx, machine_dn, "rIDSetReferences", &rid_set_dn);
	if (ret == LDB_ERR_NO_SUCH_ATTRIBUTE) {
		ret = ridalloc_create_rid_set_ntds(module, tmp_ctx, rid_manager_dn, ntds_dn, &rid_set_dn);
		talloc_free(tmp_ctx);
		return ret;
	}

	if (ret != LDB_SUCCESS) {
		ldb_asprintf_errstring(ldb, "Failed to find rIDSetReferences in %s - %s",
				       ldb_dn_get_linearized(machine_dn), ldb_errstring(ldb));
		talloc_free(tmp_ctx);
		return ret;
	}

	if (exop->fsmo_info != 0) {
		const char *attrs[] = { "rIDAllocationPool", NULL };
		struct ldb_result *res;
		uint64_t alloc_pool;

		ret = dsdb_module_search_dn(module, tmp_ctx, &res, rid_set_dn,
		                            attrs, DSDB_FLAG_NEXT_MODULE);
		if (ret != LDB_SUCCESS) {
			ldb_asprintf_errstring(ldb, __location__ ": No RID Set %s",
					       ldb_dn_get_linearized(rid_set_dn));
			talloc_free(tmp_ctx);
			return ret;
		}

		alloc_pool = ldb_msg_find_attr_as_uint64(res->msgs[0], "rIDAllocationPool", 0);
		if (alloc_pool != exop->fsmo_info) {
			/* it has already been updated */
			DEBUG(2,(__location__ ": rIDAllocationPool fsmo_info mismatch - already changed (0x%llx 0x%llx)\n",
				 (unsigned long long)exop->fsmo_info,
				 (unsigned long long)alloc_pool));
			talloc_free(tmp_ctx);
			return LDB_SUCCESS;
		}
	}

	ret = ridalloc_refresh_rid_set_ntds(module, rid_manager_dn, ntds_dn, &new_pool);
	talloc_free(tmp_ctx);
	return ret;
}