summaryrefslogtreecommitdiff
path: root/source4/rpc_server/drsuapi/getncchanges.c
blob: a9bb1c0b4e88cc11e3d4fdfda156009b7da40dbd (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
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
/* 
   Unix SMB/CIFS implementation.

   implement the DRSUpdateRefs call

   Copyright (C) Anatoliy Atanasov 2009
   Copyright (C) Andrew Tridgell 2009
   
   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/>.
*/

#include "includes.h"
#include "rpc_server/dcerpc_server.h"
#include "dsdb/samdb/samdb.h"
#include "param/param.h"
#include "librpc/gen_ndr/ndr_drsblobs.h"
#include "librpc/gen_ndr/ndr_drsuapi.h"
#include "rpc_server/drsuapi/dcesrv_drsuapi.h"
#include "rpc_server/dcerpc_server_proto.h"
#include "../libcli/drsuapi/drsuapi.h"
#include "libcli/security/security.h"
#include "lib/util/binsearch.h"
#include "lib/util/tsort.h"
#include "auth/session.h"

/*
  build a DsReplicaObjectIdentifier from a ldb msg
 */
static struct drsuapi_DsReplicaObjectIdentifier *get_object_identifier(TALLOC_CTX *mem_ctx,
								       struct ldb_message *msg)
{
	struct drsuapi_DsReplicaObjectIdentifier *identifier;
	struct dom_sid *sid;

	identifier = talloc(mem_ctx, struct drsuapi_DsReplicaObjectIdentifier);
	if (identifier == NULL) {
		return NULL;
	}

	identifier->dn = ldb_dn_alloc_linearized(identifier, msg->dn);
	identifier->guid = samdb_result_guid(msg, "objectGUID");

	sid = samdb_result_dom_sid(identifier, msg, "objectSid");
	if (sid) {
		identifier->sid = *sid;
	} else {
		ZERO_STRUCT(identifier->sid);
	}
	return identifier;
}

static int udv_compare(const struct GUID *guid1, struct GUID guid2)
{
	return GUID_compare(guid1, &guid2);
}

/*
  see if we can filter an attribute using the uptodateness_vector
 */
static bool udv_filter(const struct drsuapi_DsReplicaCursorCtrEx *udv,
		       const struct GUID *originating_invocation_id,
		       uint64_t originating_usn)
{
	const struct drsuapi_DsReplicaCursor *c;
	if (udv == NULL) return false;
	BINARY_ARRAY_SEARCH(udv->cursors, udv->count, source_dsa_invocation_id, 
			    originating_invocation_id, udv_compare, c);
	if (c && originating_usn <= c->highest_usn) {
		return true;
	}
	return false;
	
}

/* 
  drsuapi_DsGetNCChanges for one object
*/
static WERROR get_nc_changes_build_object(struct drsuapi_DsReplicaObjectListItemEx *obj,
					  struct ldb_message *msg,
					  struct ldb_context *sam_ctx,
					  struct ldb_dn *ncRoot_dn,
					  struct dsdb_schema *schema,
					  DATA_BLOB *session_key,
					  uint64_t highest_usn,
					  uint32_t replica_flags,
					  struct drsuapi_DsReplicaCursorCtrEx *uptodateness_vector)
{
	const struct ldb_val *md_value;
	unsigned int i, n;
	struct replPropertyMetaDataBlob md;
	uint32_t rid = 0;
	enum ndr_err_code ndr_err;
	uint32_t *attids;
	const char *rdn;
	const struct dsdb_attribute *rdn_sa;
	unsigned int instanceType;

	instanceType = ldb_msg_find_attr_as_uint(msg, "instanceType", 0);
	if (instanceType & INSTANCE_TYPE_IS_NC_HEAD) {
		obj->is_nc_prefix = true;
		obj->parent_object_guid = NULL;
	} else {
		obj->is_nc_prefix = false;
		obj->parent_object_guid = talloc(obj, struct GUID);
		if (obj->parent_object_guid == NULL) {
			return WERR_DS_DRA_INTERNAL_ERROR;
		}
		*obj->parent_object_guid = samdb_result_guid(msg, "parentGUID");
		if (GUID_all_zero(obj->parent_object_guid)) {
			DEBUG(0,(__location__ ": missing parentGUID for %s\n",
				 ldb_dn_get_linearized(msg->dn)));
			return WERR_DS_DRA_INTERNAL_ERROR;
		}
	}
	obj->next_object = NULL;
	
	md_value = ldb_msg_find_ldb_val(msg, "replPropertyMetaData");
	if (!md_value) {
		/* nothing to send */
		return WERR_OK;
	}

	if (instanceType & INSTANCE_TYPE_UNINSTANT) {
		/* don't send uninstantiated objects */
		return WERR_OK;
	}

	ndr_err = ndr_pull_struct_blob(md_value, obj, &md,
				       (ndr_pull_flags_fn_t)ndr_pull_replPropertyMetaDataBlob);
	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
		return WERR_DS_DRA_INTERNAL_ERROR;
	}
	
	if (md.version != 1) {
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	rdn = ldb_dn_get_rdn_name(msg->dn);
	if (rdn == NULL) {
		DEBUG(0,(__location__ ": No rDN for %s\n", ldb_dn_get_linearized(msg->dn)));
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	rdn_sa = dsdb_attribute_by_lDAPDisplayName(schema, rdn);
	if (rdn_sa == NULL) {
		DEBUG(0,(__location__ ": Can't find dsds_attribute for rDN %s in %s\n", 
			 rdn, ldb_dn_get_linearized(msg->dn)));
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	obj->meta_data_ctr = talloc(obj, struct drsuapi_DsReplicaMetaDataCtr);
	attids = talloc_array(obj, uint32_t, md.ctr.ctr1.count);

	obj->object.identifier = get_object_identifier(obj, msg);
	if (obj->object.identifier == NULL) {
		return WERR_NOMEM;
	}
	dom_sid_split_rid(NULL, &obj->object.identifier->sid, NULL, &rid);
	
	obj->meta_data_ctr->meta_data = talloc_array(obj, struct drsuapi_DsReplicaMetaData, md.ctr.ctr1.count);
	for (n=i=0; i<md.ctr.ctr1.count; i++) {
		const struct dsdb_attribute *sa;
		/* if the attribute has not changed, and it is not the
		   instanceType then don't include it */
		if (md.ctr.ctr1.array[i].local_usn < highest_usn &&
		    md.ctr.ctr1.array[i].attid != DRSUAPI_ATTRIBUTE_instanceType) continue;

		/* don't include the rDN */
		if (md.ctr.ctr1.array[i].attid == rdn_sa->attributeID_id) continue;

		sa = dsdb_attribute_by_attributeID_id(schema, md.ctr.ctr1.array[i].attid);
		if (!sa) {
			DEBUG(0,(__location__ ": Failed to find attribute in schema for attrid %u mentioned in replPropertyMetaData of %s\n", 
				 (unsigned int)md.ctr.ctr1.array[i].attid, 
				 ldb_dn_get_linearized(msg->dn)));
			return WERR_DS_DRA_INTERNAL_ERROR;		
		}

		if (sa->linkID) {
			struct ldb_message_element *el;
			el = ldb_msg_find_element(msg, sa->lDAPDisplayName);
			if (el && el->num_values && dsdb_dn_is_upgraded_link_val(&el->values[0])) {
				/* don't send upgraded links inline */
				continue;
			}
		}

		/* filter by uptodateness_vector */
		if (md.ctr.ctr1.array[i].attid != DRSUAPI_ATTRIBUTE_instanceType &&
		    udv_filter(uptodateness_vector,
			       &md.ctr.ctr1.array[i].originating_invocation_id, 
			       md.ctr.ctr1.array[i].originating_usn)) {
			continue;
		}

		/*
		 * If the recipient is a RODC, then we should not add any
		 * RODC filtered attribute
		 *
		 * TODO: This is not strictly correct, as it doesn't allow for administrators
		 * to setup some users to transfer passwords to specific RODCs. To support that
		 * we would instead remove this check and rely on extended ACL checking in the dsdb
		 * acl module.
		 */
		if (dsdb_attr_in_rodc_fas(replica_flags, sa)) {
			continue;
		}

		obj->meta_data_ctr->meta_data[n].originating_change_time = md.ctr.ctr1.array[i].originating_change_time;
		obj->meta_data_ctr->meta_data[n].version = md.ctr.ctr1.array[i].version;
		obj->meta_data_ctr->meta_data[n].originating_invocation_id = md.ctr.ctr1.array[i].originating_invocation_id;
		obj->meta_data_ctr->meta_data[n].originating_usn = md.ctr.ctr1.array[i].originating_usn;
		attids[n] = md.ctr.ctr1.array[i].attid;
		n++;
	}

	/* ignore it if its an empty change. Note that renames always
	 * change the 'name' attribute, so they won't be ignored by
	 * this */
	if (n == 0 ||
	    (n == 1 && attids[0] == DRSUAPI_ATTRIBUTE_instanceType)) {
		talloc_free(obj->meta_data_ctr);
		obj->meta_data_ctr = NULL;
		return WERR_OK;
	}

	obj->meta_data_ctr->count = n;

	obj->object.flags = DRSUAPI_DS_REPLICA_OBJECT_FROM_MASTER;
	obj->object.attribute_ctr.num_attributes = obj->meta_data_ctr->count;
	obj->object.attribute_ctr.attributes = talloc_array(obj, struct drsuapi_DsReplicaAttribute,
							    obj->object.attribute_ctr.num_attributes);

	/*
	 * Note that the meta_data array and the attributes array must
	 * be the same size and in the same order
	 */
	for (i=0; i<obj->object.attribute_ctr.num_attributes; i++) {
		struct ldb_message_element *el;
		WERROR werr;
		const struct dsdb_attribute *sa;
	
		sa = dsdb_attribute_by_attributeID_id(schema, attids[i]);
		if (!sa) {
			DEBUG(0,("Unable to find attributeID %u in schema\n", attids[i]));
			return WERR_DS_DRA_INTERNAL_ERROR;
		}

		el = ldb_msg_find_element(msg, sa->lDAPDisplayName);
		if (el == NULL) {
			/* this happens for attributes that have been removed */
			DEBUG(5,("No element '%s' for attributeID %u in message\n",
				 sa->lDAPDisplayName, attids[i]));
			ZERO_STRUCT(obj->object.attribute_ctr.attributes[i]);
			obj->object.attribute_ctr.attributes[i].attid = attids[i];
		} else {
			werr = dsdb_attribute_ldb_to_drsuapi(sam_ctx, schema, el, obj,
							     &obj->object.attribute_ctr.attributes[i]);
			if (!W_ERROR_IS_OK(werr)) {
				DEBUG(0,("Unable to convert %s to DRS object - %s\n", 
					 sa->lDAPDisplayName, win_errstr(werr)));
				return werr;
			}
			/* if DRSUAPI_DRS_SPECIAL_SECRET_PROCESSING is set
			 * check if attribute is secret and send a null value
			 */
			if (replica_flags & DRSUAPI_DRS_SPECIAL_SECRET_PROCESSING) {
				drsuapi_process_secret_attribute(&obj->object.attribute_ctr.attributes[i],
								 &obj->meta_data_ctr->meta_data[i]);
			}
			/* some attributes needs to be encrypted
			   before being sent */
			werr = drsuapi_encrypt_attribute(obj, session_key, rid, 
							 &obj->object.attribute_ctr.attributes[i]);
			if (!W_ERROR_IS_OK(werr)) {
				DEBUG(0,("Unable to encrypt %s in DRS object - %s\n", 
					 sa->lDAPDisplayName, win_errstr(werr)));
				return werr;
			}
		}
	}

	return WERR_OK;
}


/*
  add one linked attribute from an object to the list of linked
  attributes in a getncchanges request
 */
static WERROR get_nc_changes_add_la(TALLOC_CTX *mem_ctx,
				    struct ldb_context *sam_ctx,
				    const struct dsdb_schema *schema,
				    const struct dsdb_attribute *sa,
				    struct ldb_message *msg,
				    struct dsdb_dn *dsdb_dn,
				    struct drsuapi_DsReplicaLinkedAttribute **la_list,
				    uint32_t *la_count)
{
	struct drsuapi_DsReplicaLinkedAttribute *la;
	bool active;
	NTSTATUS status;
	WERROR werr;

	(*la_list) = talloc_realloc(mem_ctx, *la_list, struct drsuapi_DsReplicaLinkedAttribute, (*la_count)+1);
	W_ERROR_HAVE_NO_MEMORY(*la_list);

	la = &(*la_list)[*la_count];

	la->identifier = get_object_identifier(*la_list, msg);
	W_ERROR_HAVE_NO_MEMORY(la->identifier);

	active = (dsdb_dn_rmd_flags(dsdb_dn->dn) & DSDB_RMD_FLAG_DELETED) == 0;

	la->attid = sa->attributeID_id;
	la->flags = active?DRSUAPI_DS_LINKED_ATTRIBUTE_FLAG_ACTIVE:0;

	status = dsdb_get_extended_dn_nttime(dsdb_dn->dn, &la->originating_add_time, "RMD_ADDTIME");
	if (!NT_STATUS_IS_OK(status)) {
		return ntstatus_to_werror(status);
	}
	status = dsdb_get_extended_dn_uint32(dsdb_dn->dn, &la->meta_data.version, "RMD_VERSION");
	if (!NT_STATUS_IS_OK(status)) {
		return ntstatus_to_werror(status);
	}
	status = dsdb_get_extended_dn_nttime(dsdb_dn->dn, &la->meta_data.originating_change_time, "RMD_CHANGETIME");
	if (!NT_STATUS_IS_OK(status)) {
		return ntstatus_to_werror(status);
	}
	status = dsdb_get_extended_dn_guid(dsdb_dn->dn, &la->meta_data.originating_invocation_id, "RMD_INVOCID");
	if (!NT_STATUS_IS_OK(status)) {
		return ntstatus_to_werror(status);
	}
	status = dsdb_get_extended_dn_uint64(dsdb_dn->dn, &la->meta_data.originating_usn, "RMD_ORIGINATING_USN");
	if (!NT_STATUS_IS_OK(status)) {
		return ntstatus_to_werror(status);
	}

	werr = dsdb_dn_la_to_blob(sam_ctx, sa, schema, *la_list, dsdb_dn, &la->value.blob);
	W_ERROR_NOT_OK_RETURN(werr);

	(*la_count)++;
	return WERR_OK;
}


/*
  add linked attributes from an object to the list of linked
  attributes in a getncchanges request
 */
static WERROR get_nc_changes_add_links(struct ldb_context *sam_ctx,
				       TALLOC_CTX *mem_ctx,
				       struct ldb_dn *ncRoot_dn,
				       struct dsdb_schema *schema,
				       uint64_t highest_usn,
				       uint32_t replica_flags,
				       struct ldb_message *msg,
				       struct drsuapi_DsReplicaLinkedAttribute **la_list,
				       uint32_t *la_count,
				       struct drsuapi_DsReplicaCursorCtrEx *uptodateness_vector)
{
	unsigned int i;
	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
	uint64_t uSNChanged = ldb_msg_find_attr_as_int(msg, "uSNChanged", -1);

	for (i=0; i<msg->num_elements; i++) {
		struct ldb_message_element *el = &msg->elements[i];
		const struct dsdb_attribute *sa;
		unsigned int j;

		sa = dsdb_attribute_by_lDAPDisplayName(schema, el->name);

		if (!sa || sa->linkID == 0 || (sa->linkID & 1)) {
			/* we only want forward links */
			continue;
		}

		if (el->num_values && !dsdb_dn_is_upgraded_link_val(&el->values[0])) {
			/* its an old style link, it will have been
			 * sent in the main replication data */
			continue;
		}

		for (j=0; j<el->num_values; j++) {
			struct dsdb_dn *dsdb_dn;
			uint64_t local_usn;
			NTSTATUS status;
			WERROR werr;

			dsdb_dn = dsdb_dn_parse(tmp_ctx, sam_ctx, &el->values[j], sa->syntax->ldap_oid);
			if (dsdb_dn == NULL) {
				DEBUG(1,(__location__ ": Failed to parse DN for %s in %s\n",
					 el->name, ldb_dn_get_linearized(msg->dn)));
				talloc_free(tmp_ctx);
				return WERR_DS_DRA_INTERNAL_ERROR;
			}

			status = dsdb_get_extended_dn_uint64(dsdb_dn->dn, &local_usn, "RMD_LOCAL_USN");
			if (!NT_STATUS_IS_OK(status)) {
				/* this can happen for attributes
				   given to us with old style meta
				   data */
				continue;
			}

			if (local_usn > uSNChanged) {
				DEBUG(1,(__location__ ": uSNChanged less than RMD_LOCAL_USN for %s on %s\n",
					 el->name, ldb_dn_get_linearized(msg->dn)));
				talloc_free(tmp_ctx);
				return WERR_DS_DRA_INTERNAL_ERROR;
			}

			if (local_usn < highest_usn) {
				continue;
			}

			werr = get_nc_changes_add_la(mem_ctx, sam_ctx, schema, sa, msg,
						     dsdb_dn, la_list, la_count);
			if (!W_ERROR_IS_OK(werr)) {
				talloc_free(tmp_ctx);
				return werr;
			}
		}
	}

	talloc_free(tmp_ctx);
	return WERR_OK;
}

/*
  fill in the cursors return based on the replUpToDateVector for the ncRoot_dn
 */
static WERROR get_nc_changes_udv(struct ldb_context *sam_ctx,
				 struct ldb_dn *ncRoot_dn,
				 struct drsuapi_DsReplicaCursor2CtrEx *udv)
{
	int ret;

	udv->version = 2;
	udv->reserved1 = 0;
	udv->reserved2 = 0;

	ret = dsdb_load_udv_v2(sam_ctx, ncRoot_dn, udv, &udv->cursors, &udv->count);
	if (ret != LDB_SUCCESS) {
		DEBUG(0,(__location__ ": Failed to load UDV for %s - %s\n",
			 ldb_dn_get_linearized(ncRoot_dn), ldb_errstring(sam_ctx)));
		return WERR_DS_DRA_INTERNAL_ERROR;
	}
	
	return WERR_OK;
}


/* comparison function for linked attributes - see CompareLinks() in
 * MS-DRSR section 4.1.10.5.17 */
static int linked_attribute_compare(const struct drsuapi_DsReplicaLinkedAttribute *la1,
				    const struct drsuapi_DsReplicaLinkedAttribute *la2,
				    struct ldb_context *sam_ctx)
{
	int c;
	WERROR werr;
	TALLOC_CTX *tmp_ctx;
	const struct dsdb_schema *schema;
	const struct dsdb_attribute *schema_attrib;
	struct dsdb_dn *dn1, *dn2;
	struct GUID guid1, guid2;
	NTSTATUS status;

	c = GUID_compare(&la1->identifier->guid,
			 &la2->identifier->guid);
	if (c != 0) return c;

	if (la1->attid != la2->attid) {
		return la1->attid < la2->attid? -1:1;
	}

	if ((la1->flags & DRSUAPI_DS_LINKED_ATTRIBUTE_FLAG_ACTIVE) !=
	    (la2->flags & DRSUAPI_DS_LINKED_ATTRIBUTE_FLAG_ACTIVE)) {
		return (la1->flags & DRSUAPI_DS_LINKED_ATTRIBUTE_FLAG_ACTIVE)? 1:-1;
	}

	/* we need to get the target GUIDs to compare */
	tmp_ctx = talloc_new(sam_ctx);

	schema = dsdb_get_schema(sam_ctx, tmp_ctx);
	schema_attrib = dsdb_attribute_by_attributeID_id(schema, la1->attid);

	werr = dsdb_dn_la_from_blob(sam_ctx, schema_attrib, schema, tmp_ctx, la1->value.blob, &dn1);
	if (!W_ERROR_IS_OK(werr)) {
		DEBUG(0,(__location__ ": Bad la1 blob in sort\n"));
		talloc_free(tmp_ctx);
		return 0;
	}

	werr = dsdb_dn_la_from_blob(sam_ctx, schema_attrib, schema, tmp_ctx, la2->value.blob, &dn2);
	if (!W_ERROR_IS_OK(werr)) {
		DEBUG(0,(__location__ ": Bad la2 blob in sort\n"));
		talloc_free(tmp_ctx);
		return 0;
	}

	status = dsdb_get_extended_dn_guid(dn1->dn, &guid1, "GUID");
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,(__location__ ": Bad la1 guid in sort\n"));
		talloc_free(tmp_ctx);
		return 0;
	}
	status = dsdb_get_extended_dn_guid(dn2->dn, &guid2, "GUID");
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,(__location__ ": Bad la2 guid in sort\n"));
		talloc_free(tmp_ctx);
		return 0;
	}

	talloc_free(tmp_ctx);

	return GUID_compare(&guid1, &guid2);
}


/*
  sort the objects we send by tree order
 */
static int site_res_cmp_parent_order(struct ldb_message **m1, struct ldb_message **m2)
{
	return ldb_dn_compare((*m2)->dn, (*m1)->dn);
}

/*
  sort the objects we send first by uSNChanged
 */
static int site_res_cmp_usn_order(struct ldb_message **m1, struct ldb_message **m2)
{
	unsigned usnchanged1, usnchanged2;
	unsigned cn1, cn2;
	cn1 = ldb_dn_get_comp_num((*m1)->dn);
	cn2 = ldb_dn_get_comp_num((*m2)->dn);
	if (cn1 != cn2) {
		return cn1 > cn2 ? 1 : -1;
	}
	usnchanged1 = ldb_msg_find_attr_as_uint(*m1, "uSNChanged", 0);
	usnchanged2 = ldb_msg_find_attr_as_uint(*m2, "uSNChanged", 0);
	if (usnchanged1 == usnchanged2) {
		return 0;
	}
	return usnchanged1 > usnchanged2 ? 1 : -1;
}


/*
  handle a DRSUAPI_EXOP_FSMO_RID_ALLOC call
 */
static WERROR getncchanges_rid_alloc(struct drsuapi_bind_state *b_state,
				     TALLOC_CTX *mem_ctx,
				     struct drsuapi_DsGetNCChangesRequest8 *req8,
				     struct drsuapi_DsGetNCChangesCtr6 *ctr6)
{
	struct ldb_dn *rid_manager_dn, *fsmo_role_dn, *req_dn;
	int ret;
	struct ldb_context *ldb = b_state->sam_ctx;
	struct ldb_result *ext_res;
	struct ldb_dn *base_dn;
	struct dsdb_fsmo_extended_op *exop;

	/*
	  steps:
	    - verify that the DN being asked for is the RID Manager DN
	    - verify that we are the RID Manager
	 */

	/* work out who is the RID Manager */
	ret = samdb_rid_manager_dn(ldb, mem_ctx, &rid_manager_dn);
	if (ret != LDB_SUCCESS) {
		DEBUG(0, (__location__ ": Failed to find RID Manager object - %s\n", ldb_errstring(ldb)));
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	req_dn = ldb_dn_new(mem_ctx, ldb, req8->naming_context->dn);
	if (!req_dn ||
	    !ldb_dn_validate(req_dn) ||
	    ldb_dn_compare(req_dn, rid_manager_dn) != 0) {
		/* that isn't the RID Manager DN */
		DEBUG(0,(__location__ ": RID Alloc request for wrong DN %s\n",
			 req8->naming_context->dn));
		ctr6->extended_ret = DRSUAPI_EXOP_ERR_MISMATCH;
		return WERR_OK;
	}

	/* find the DN of the RID Manager */
	ret = samdb_reference_dn(ldb, mem_ctx, rid_manager_dn, "fSMORoleOwner", &fsmo_role_dn);
	if (ret != LDB_SUCCESS) {
		DEBUG(0,(__location__ ": Failed to find fSMORoleOwner in RID Manager object - %s\n",
			 ldb_errstring(ldb)));
		ctr6->extended_ret = DRSUAPI_EXOP_ERR_FSMO_NOT_OWNER;
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	if (ldb_dn_compare(samdb_ntds_settings_dn(ldb), fsmo_role_dn) != 0) {
		/* we're not the RID Manager - go away */
		DEBUG(0,(__location__ ": RID Alloc request when not RID Manager\n"));
		ctr6->extended_ret = DRSUAPI_EXOP_ERR_FSMO_NOT_OWNER;
		return WERR_OK;
	}

	exop = talloc(mem_ctx, struct dsdb_fsmo_extended_op);
	W_ERROR_HAVE_NO_MEMORY(exop);

	exop->fsmo_info = req8->fsmo_info;
	exop->destination_dsa_guid = req8->destination_dsa_guid;

	ret = ldb_transaction_start(ldb);
	if (ret != LDB_SUCCESS) {
		DEBUG(0,(__location__ ": Failed transaction start - %s\n",
			 ldb_errstring(ldb)));
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	ret = ldb_extended(ldb, DSDB_EXTENDED_ALLOCATE_RID_POOL, exop, &ext_res);
	if (ret != LDB_SUCCESS) {
		DEBUG(0,(__location__ ": Failed extended allocation RID pool operation - %s\n",
			 ldb_errstring(ldb)));
		ldb_transaction_cancel(ldb);
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	ret = ldb_transaction_commit(ldb);
	if (ret != LDB_SUCCESS) {
		DEBUG(0,(__location__ ": Failed transaction commit - %s\n",
			 ldb_errstring(ldb)));
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	talloc_free(ext_res);

	base_dn = ldb_get_default_basedn(ldb);

	DEBUG(2,("Allocated RID pool for server %s\n",
		 GUID_string(mem_ctx, &req8->destination_dsa_guid)));

	ctr6->extended_ret = DRSUAPI_EXOP_ERR_SUCCESS;

	return WERR_OK;
}



/* state of a partially completed getncchanges call */
struct drsuapi_getncchanges_state {
	struct ldb_result *site_res;
	uint32_t num_sent;
	struct ldb_dn *ncRoot_dn;
	uint64_t min_usn;
	uint64_t highest_usn;
	struct ldb_dn *last_dn;
	struct drsuapi_DsReplicaLinkedAttribute *la_list;
	uint32_t la_count;
	struct drsuapi_DsReplicaCursorCtrEx *uptodateness_vector;
};

/* 
  drsuapi_DsGetNCChanges

  see MS-DRSR 4.1.10.5.2 for basic logic of this function
*/
WERROR dcesrv_drsuapi_DsGetNCChanges(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
				     struct drsuapi_DsGetNCChanges *r)
{
	struct drsuapi_DsReplicaObjectIdentifier *ncRoot;
	int ret;
	unsigned int i;
	struct dsdb_schema *schema;
	struct drsuapi_DsReplicaOIDMapping_Ctr *ctr;
	struct drsuapi_DsReplicaObjectListItemEx **currentObject;
	NTSTATUS status;
	DATA_BLOB session_key;
	const char *attrs[] = { "*", "distinguishedName",
				"nTSecurityDescriptor",
				"parentGUID",
				"replPropertyMetaData",
				"unicodePwd",
				"dBCSPwd",
				"ntPwdHistory",
				"lmPwdHistory",
				"supplementalCredentials",
				NULL };
	WERROR werr;
	struct dcesrv_handle *h;
	struct drsuapi_bind_state *b_state;	
	struct drsuapi_getncchanges_state *getnc_state;
	struct drsuapi_DsGetNCChangesRequest8 *req8;
	uint32_t options;
	uint32_t max_objects;
	struct ldb_dn *search_dn = NULL;
	bool am_rodc;
	enum security_user_level security_level;

	DCESRV_PULL_HANDLE_WERR(h, r->in.bind_handle, DRSUAPI_BIND_HANDLE);
	b_state = h->data;

	*r->out.level_out = 6;
	/* TODO: linked attributes*/
	r->out.ctr->ctr6.linked_attributes_count = 0;
	r->out.ctr->ctr6.linked_attributes = NULL;

	r->out.ctr->ctr6.object_count = 0;
	r->out.ctr->ctr6.nc_object_count = 0;
	r->out.ctr->ctr6.more_data = false;
	r->out.ctr->ctr6.uptodateness_vector = NULL;

	/* a RODC doesn't allow for any replication */
	ret = samdb_rodc(b_state->sam_ctx, &am_rodc);
	if (ret == LDB_SUCCESS && am_rodc) {
		DEBUG(0,(__location__ ": DsGetNCChanges attempt on RODC\n"));
		return WERR_DS_DRA_SOURCE_DISABLED;
	}

	/* Check request revision. 
	   TODO: Adding mappings to req8 from the other levels
	 */
	if (r->in.level != 8) {
		DEBUG(0,(__location__ ": Request for DsGetNCChanges with unsupported level %u\n",
			 r->in.level));
		return WERR_REVISION_MISMATCH;
	}

	req8 = &r->in.req->req8;

        /* Perform access checks. */
	/* TODO: we need to support a sync on a specific non-root
	 * DN. We'll need to find the real partition root here */
	ncRoot = req8->naming_context;
	if (ncRoot == NULL) {
		DEBUG(0,(__location__ ": Request for DsGetNCChanges with no NC\n"));
		return WERR_DS_DRA_INVALID_PARAMETER;
	}

	if (samdb_ntds_options(b_state->sam_ctx, &options) != LDB_SUCCESS) {
		return WERR_DS_DRA_INTERNAL_ERROR;
	}
	
	if ((options & DS_NTDSDSA_OPT_DISABLE_OUTBOUND_REPL) &&
	    !(req8->replica_flags & DRSUAPI_DRS_SYNC_FORCED)) {
		return WERR_DS_DRA_SOURCE_DISABLED;
	}

	werr = drs_security_level_check(dce_call, "DsGetNCChanges", SECURITY_RO_DOMAIN_CONTROLLER);
	if (!W_ERROR_IS_OK(werr)) {
		return werr;
	}

	/* for non-administrator replications, check that they have
	   given the correct source_dsa_invocation_id */
	security_level = security_session_user_level(dce_call->conn->auth_state.session_info,
						     samdb_domain_sid(b_state->sam_ctx));
	if (security_level == SECURITY_RO_DOMAIN_CONTROLLER &&
	    (req8->replica_flags & DRSUAPI_DRS_WRIT_REP)) {
		DEBUG(0,(__location__ ": Attempt to do writeable replication by RODC %s\n",
			 dom_sid_string(mem_ctx,
					dce_call->conn->auth_state.session_info->security_token->user_sid)));
		return WERR_DS_DRA_INVALID_PARAMETER;
	}


	if (req8->replica_flags & DRSUAPI_DRS_FULL_SYNC_PACKET) {
		/* Ignore the _in_ uptpdateness vector*/
		req8->uptodateness_vector = NULL;
	} 

	/* we don't yet support extended operations */
	switch (req8->extended_op) {
	case DRSUAPI_EXOP_NONE:
		break;

	case DRSUAPI_EXOP_FSMO_RID_ALLOC:
		werr = getncchanges_rid_alloc(b_state, mem_ctx, req8, &r->out.ctr->ctr6);
		W_ERROR_NOT_OK_RETURN(werr);
		search_dn = ldb_get_default_basedn(b_state->sam_ctx);
		break;

	case DRSUAPI_EXOP_FSMO_REQ_ROLE:
	case DRSUAPI_EXOP_FSMO_RID_REQ_ROLE:
	case DRSUAPI_EXOP_FSMO_REQ_PDC:
	case DRSUAPI_EXOP_FSMO_ABANDON_ROLE:
	case DRSUAPI_EXOP_REPL_OBJ:
	case DRSUAPI_EXOP_REPL_SECRET:
		DEBUG(0,(__location__ ": Request for DsGetNCChanges unsupported extended op 0x%x\n",
			 (unsigned)req8->extended_op));
		return WERR_DS_DRA_NOT_SUPPORTED;
	}

	getnc_state = b_state->getncchanges_state;

	/* see if a previous replication has been abandoned */
	if (getnc_state) {
		struct ldb_dn *new_dn = ldb_dn_new(getnc_state, b_state->sam_ctx, ncRoot->dn);
		if (ldb_dn_compare(new_dn, getnc_state->ncRoot_dn) != 0) {
			DEBUG(0,(__location__ ": DsGetNCChanges 2nd replication on different DN %s %s (last_dn %s)\n",
				 ldb_dn_get_linearized(new_dn),
				 ldb_dn_get_linearized(getnc_state->ncRoot_dn),
				 ldb_dn_get_linearized(getnc_state->last_dn)));
			talloc_free(getnc_state);
			getnc_state = NULL;
		}
	}

	if (getnc_state == NULL) {
		getnc_state = talloc_zero(b_state, struct drsuapi_getncchanges_state);
		if (getnc_state == NULL) {
			return WERR_NOMEM;
		}
		b_state->getncchanges_state = getnc_state;
		getnc_state->ncRoot_dn = ldb_dn_new(getnc_state, b_state->sam_ctx, ncRoot->dn);
	}

	if (!ldb_dn_validate(getnc_state->ncRoot_dn) ||
	    ldb_dn_is_null(getnc_state->ncRoot_dn)) {
		DEBUG(0,(__location__ ": Bad DN '%s'\n", ncRoot->dn));
		return WERR_DS_DRA_INVALID_PARAMETER;
	}

	/* we need the session key for encrypting password attributes */
	status = dcesrv_inherited_session_key(dce_call->conn, &session_key);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(0,(__location__ ": Failed to get session key\n"));
		return WERR_DS_DRA_INTERNAL_ERROR;		
	}

	/* 
	   TODO: MS-DRSR section 4.1.10.1.1
	   Work out if this is the start of a new cycle */

	if (getnc_state->site_res == NULL) {
		char* search_filter;
		enum ldb_scope scope = LDB_SCOPE_SUBTREE;
		const char *extra_filter;

		extra_filter = lp_parm_string(dce_call->conn->dce_ctx->lp_ctx, NULL, "drs", "object filter");

		getnc_state->min_usn = req8->highwatermark.highest_usn;

		/* Construct response. */
		search_filter = talloc_asprintf(mem_ctx,
						"(uSNChanged>=%llu)",
						(unsigned long long)(getnc_state->min_usn+1));
	
		if (extra_filter) {
			search_filter = talloc_asprintf(mem_ctx, "(&%s(%s))", search_filter, extra_filter);
		}

		if (req8->replica_flags & DRSUAPI_DRS_CRITICAL_ONLY) {
			search_filter = talloc_asprintf(mem_ctx,
							"(&%s(isCriticalSystemObject=TRUE))",
							search_filter);
		}
		
		if (req8->replica_flags & DRSUAPI_DRS_ASYNC_REP) {
			scope = LDB_SCOPE_BASE;
		}
		
		if (!search_dn) {
			search_dn = getnc_state->ncRoot_dn;
		}

		DEBUG(1,(__location__ ": getncchanges on %s using filter %s\n",
			 ldb_dn_get_linearized(getnc_state->ncRoot_dn), search_filter));
		ret = drsuapi_search_with_extended_dn(b_state->sam_ctx, getnc_state, &getnc_state->site_res,
						      search_dn, scope, attrs,
						      search_filter);
		if (ret != LDB_SUCCESS) {
			return WERR_DS_DRA_INTERNAL_ERROR;
		}

		if (req8->replica_flags & DRSUAPI_DRS_GET_ANC) {
			TYPESAFE_QSORT(getnc_state->site_res->msgs,
				       getnc_state->site_res->count,
				       site_res_cmp_parent_order);
		} else {
			TYPESAFE_QSORT(getnc_state->site_res->msgs,
				       getnc_state->site_res->count,
				       site_res_cmp_usn_order);
		}

		getnc_state->uptodateness_vector = talloc_steal(getnc_state, req8->uptodateness_vector);
		if (getnc_state->uptodateness_vector) {
			/* make sure its sorted */
			TYPESAFE_QSORT(getnc_state->uptodateness_vector->cursors,
				       getnc_state->uptodateness_vector->count,
				       drsuapi_DsReplicaCursor_compare);
		}
	}

	/* Prefix mapping */
	schema = dsdb_get_schema(b_state->sam_ctx, mem_ctx);
	if (!schema) {
		DEBUG(0,("No schema in sam_ctx\n"));
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	r->out.ctr->ctr6.naming_context = talloc(mem_ctx, struct drsuapi_DsReplicaObjectIdentifier);
	*r->out.ctr->ctr6.naming_context = *ncRoot;

	if (dsdb_find_guid_by_dn(b_state->sam_ctx, getnc_state->ncRoot_dn, 
				 &r->out.ctr->ctr6.naming_context->guid) != LDB_SUCCESS) {
		DEBUG(0,(__location__ ": Failed to find GUID of ncRoot_dn %s\n",
			 ldb_dn_get_linearized(getnc_state->ncRoot_dn)));
		return WERR_DS_DRA_INTERNAL_ERROR;
	}

	/* find the SID if there is one */
	dsdb_find_sid_by_dn(b_state->sam_ctx, getnc_state->ncRoot_dn, &r->out.ctr->ctr6.naming_context->sid);

	dsdb_get_oid_mappings_drsuapi(schema, true, mem_ctx, &ctr);
	r->out.ctr->ctr6.mapping_ctr = *ctr;

	r->out.ctr->ctr6.source_dsa_guid = *(samdb_ntds_objectGUID(b_state->sam_ctx));
	r->out.ctr->ctr6.source_dsa_invocation_id = *(samdb_ntds_invocation_id(b_state->sam_ctx));

	r->out.ctr->ctr6.old_highwatermark = req8->highwatermark;
	r->out.ctr->ctr6.new_highwatermark = req8->highwatermark;

	r->out.ctr->ctr6.first_object = NULL;
	currentObject = &r->out.ctr->ctr6.first_object;

	/* use this to force single objects at a time, which is useful
	 * for working out what object is giving problems
	 */
	max_objects = lp_parm_int(dce_call->conn->dce_ctx->lp_ctx, NULL, "drs", "max object sync", 1000);
	if (req8->max_object_count < max_objects) {
		max_objects = req8->max_object_count;
	}

	for(i=getnc_state->num_sent; 
	    i<getnc_state->site_res->count && 
		    (r->out.ctr->ctr6.object_count < max_objects);
	    i++) {
		int uSN;
		struct drsuapi_DsReplicaObjectListItemEx *obj;
		struct ldb_message *msg = getnc_state->site_res->msgs[i];

		obj = talloc_zero(mem_ctx, struct drsuapi_DsReplicaObjectListItemEx);

		werr = get_nc_changes_build_object(obj, msg,
						   b_state->sam_ctx, getnc_state->ncRoot_dn, 
						   schema, &session_key, getnc_state->min_usn,
						   req8->replica_flags, getnc_state->uptodateness_vector);
		if (!W_ERROR_IS_OK(werr)) {
			return werr;
		}

		werr = get_nc_changes_add_links(b_state->sam_ctx, getnc_state,
						getnc_state->ncRoot_dn,
						schema, getnc_state->min_usn,
						req8->replica_flags,
						msg,
						&getnc_state->la_list,
						&getnc_state->la_count,
						getnc_state->uptodateness_vector);
		if (!W_ERROR_IS_OK(werr)) {
			return werr;
		}

		uSN = ldb_msg_find_attr_as_int(msg, "uSNChanged", -1);
		if (uSN > r->out.ctr->ctr6.new_highwatermark.tmp_highest_usn) {
			r->out.ctr->ctr6.new_highwatermark.tmp_highest_usn = uSN;
		}
		if (uSN > getnc_state->highest_usn) {
			getnc_state->highest_usn = uSN;
		}

		if (obj->meta_data_ctr == NULL) {
			DEBUG(8,(__location__ ": getncchanges skipping send of object %s\n",
				 ldb_dn_get_linearized(msg->dn)));
			/* no attributes to send */
			talloc_free(obj);
			continue;
		}

		r->out.ctr->ctr6.object_count++;
		
		*currentObject = obj;
		currentObject = &obj->next_object;

		talloc_free(getnc_state->last_dn);
		getnc_state->last_dn = ldb_dn_copy(getnc_state, msg->dn);

		DEBUG(8,(__location__ ": replicating object %s\n", ldb_dn_get_linearized(msg->dn)));
	}

	getnc_state->num_sent += r->out.ctr->ctr6.object_count;

	r->out.ctr->ctr6.nc_object_count = getnc_state->site_res->count;

	/* the client can us to call UpdateRefs on its behalf to
	   re-establish monitoring of the NC */
	if ((req8->replica_flags & (DRSUAPI_DRS_ADD_REF | DRSUAPI_DRS_REF_GCSPN)) &&
	    !GUID_all_zero(&req8->destination_dsa_guid)) {
		struct drsuapi_DsReplicaUpdateRefsRequest1 ureq;
		DEBUG(3,("UpdateRefs on getncchanges for %s\n",
			 GUID_string(mem_ctx, &req8->destination_dsa_guid)));
		ureq.naming_context = ncRoot;
		ureq.dest_dsa_dns_name = talloc_asprintf(mem_ctx, "%s._msdcs.%s",
							 GUID_string(mem_ctx, &req8->destination_dsa_guid),
							 lp_realm(dce_call->conn->dce_ctx->lp_ctx));
		if (!ureq.dest_dsa_dns_name) {
			return WERR_NOMEM;
		}
		ureq.dest_dsa_guid = req8->destination_dsa_guid;
		ureq.options = DRSUAPI_DRS_ADD_REF |
			DRSUAPI_DRS_ASYNC_OP |
			DRSUAPI_DRS_GETCHG_CHECK;
		werr = drsuapi_UpdateRefs(b_state, mem_ctx, &ureq);
		if (!W_ERROR_IS_OK(werr)) {
			DEBUG(0,(__location__ ": Failed UpdateRefs in DsGetNCChanges - %s\n",
				 win_errstr(werr)));
		}
	}

	if (i < getnc_state->site_res->count) {
		r->out.ctr->ctr6.more_data = true;
	} else {
		r->out.ctr->ctr6.linked_attributes_count = getnc_state->la_count;
		r->out.ctr->ctr6.linked_attributes = talloc_steal(mem_ctx, getnc_state->la_list);

		LDB_TYPESAFE_QSORT(r->out.ctr->ctr6.linked_attributes, r->out.ctr->ctr6.linked_attributes_count,
				   b_state->sam_ctx, linked_attribute_compare);

		r->out.ctr->ctr6.uptodateness_vector = talloc(mem_ctx, struct drsuapi_DsReplicaCursor2CtrEx);
		r->out.ctr->ctr6.new_highwatermark.highest_usn = r->out.ctr->ctr6.new_highwatermark.tmp_highest_usn;

		werr = get_nc_changes_udv(b_state->sam_ctx, getnc_state->ncRoot_dn, 
					  r->out.ctr->ctr6.uptodateness_vector);
		if (!W_ERROR_IS_OK(werr)) {
			return werr;
		}

		talloc_free(getnc_state);
		b_state->getncchanges_state = NULL;
	}

	if (req8->extended_op != DRSUAPI_EXOP_NONE) {
		r->out.ctr->ctr6.uptodateness_vector = NULL;
		r->out.ctr->ctr6.nc_object_count = 0;
		ZERO_STRUCT(r->out.ctr->ctr6.new_highwatermark);
	}

	DEBUG(r->out.ctr->ctr6.more_data?2:1,
	      ("DsGetNCChanges with uSNChanged >= %llu flags 0x%08x on %s gave %u objects (done %d/%d la=%d)\n",
	       (unsigned long long)(req8->highwatermark.highest_usn+1),
	       req8->replica_flags,
	       ncRoot->dn, r->out.ctr->ctr6.object_count,
	       i, r->out.ctr->ctr6.more_data?getnc_state->site_res->count:i,
	       r->out.ctr->ctr6.linked_attributes_count));

#if 0
	if (!r->out.ctr->ctr6.more_data) {
		NDR_PRINT_FUNCTION_DEBUG(drsuapi_DsGetNCChanges, NDR_BOTH, r);
	}
#endif

	return WERR_OK;
}