aboutsummaryrefslogtreecommitdiffstats
path: root/lib/ldb/ldb_tdb/ldb_tdb.c
blob: c7bf865de588e0e113fab3928281193f0a565535 (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
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
/*
   ldb database library

   Copyright (C) Andrew Tridgell 2004
   Copyright (C) Stefan Metzmacher 2004
   Copyright (C) Simo Sorce 2006-2008
   Copyright (C) Matthias Dieter Wallnöfer 2009-2010

     ** NOTE! The following LGPL license applies to the ldb
     ** library. This does NOT imply that all of Samba is released
     ** under the LGPL

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

   This library 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
   Lesser General Public License for more details.

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

/*
 *  Name: ldb_tdb
 *
 *  Component: ldb tdb backend
 *
 *  Description: core functions for tdb backend
 *
 *  Author: Andrew Tridgell
 *  Author: Stefan Metzmacher
 *
 *  Modifications:
 *
 *  - description: make the module use asynchronous calls
 *    date: Feb 2006
 *    Author: Simo Sorce
 *
 *  - description: make it possible to use event contexts
 *    date: Jan 2008
 *    Author: Simo Sorce
 *
 *  - description: fix up memory leaks and small bugs
 *    date: Oct 2009
 *    Author: Matthias Dieter Wallnöfer
 */

#include "ldb_tdb.h"
#include "ldb_private.h"
#include <tdb.h>

/*
  prevent memory errors on callbacks
*/
struct ltdb_req_spy {
	struct ltdb_context *ctx;
};

/*
  map a tdb error code to a ldb error code
*/
int ltdb_err_map(enum TDB_ERROR tdb_code)
{
	switch (tdb_code) {
	case TDB_SUCCESS:
		return LDB_SUCCESS;
	case TDB_ERR_CORRUPT:
	case TDB_ERR_OOM:
	case TDB_ERR_EINVAL:
		return LDB_ERR_OPERATIONS_ERROR;
	case TDB_ERR_IO:
		return LDB_ERR_PROTOCOL_ERROR;
	case TDB_ERR_LOCK:
	case TDB_ERR_NOLOCK:
		return LDB_ERR_BUSY;
	case TDB_ERR_LOCK_TIMEOUT:
		return LDB_ERR_TIME_LIMIT_EXCEEDED;
	case TDB_ERR_EXISTS:
		return LDB_ERR_ENTRY_ALREADY_EXISTS;
	case TDB_ERR_NOEXIST:
		return LDB_ERR_NO_SUCH_OBJECT;
	case TDB_ERR_RDONLY:
		return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
	default:
		break;
	}
	return LDB_ERR_OTHER;
}

/*
  lock the database for read - use by ltdb_search and ltdb_sequence_number
*/
int ltdb_lock_read(struct ldb_module *module)
{
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	int tdb_ret = 0;
	int ret;

	if (ltdb->in_transaction == 0 &&
	    ltdb->read_lock_count == 0) {
		tdb_ret = tdb_lockall_read(ltdb->tdb);
	}
	if (tdb_ret == 0) {
		ltdb->read_lock_count++;
		return LDB_SUCCESS;
	}
	ret = ltdb_err_map(tdb_error(ltdb->tdb));
	if (ret == LDB_SUCCESS) {
		ret = LDB_ERR_OPERATIONS_ERROR;
	}
	ldb_debug_set(ldb_module_get_ctx(module),
		      LDB_DEBUG_FATAL,
		      "Failure during ltdb_lock_read(): %s -> %s",
		      tdb_errorstr(ltdb->tdb),
		      ldb_strerror(ret));
	return ret;
}

/*
  unlock the database after a ltdb_lock_read()
*/
int ltdb_unlock_read(struct ldb_module *module)
{
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	if (ltdb->in_transaction == 0 && ltdb->read_lock_count == 1) {
		tdb_unlockall_read(ltdb->tdb);
		ltdb->read_lock_count--;
		return 0;
	}
	ltdb->read_lock_count--;
	return 0;
}


/* 
 * Determine if this key could hold a record.  We allow the new GUID
 * index, the old DN index and a possible future ID=
 */
bool ltdb_key_is_record(TDB_DATA key)
{
	if (key.dsize < 4) {
		return false;
	}

	if (memcmp(key.dptr, "DN=", 3) == 0) {
		return true;
	}
	
	if (memcmp(key.dptr, "ID=", 3) == 0) {
		return true;
	}

	if (key.dsize < sizeof(LTDB_GUID_KEY_PREFIX)) {
		return false;
	}

	if (memcmp(key.dptr, LTDB_GUID_KEY_PREFIX,
		   sizeof(LTDB_GUID_KEY_PREFIX) - 1) == 0) {
		return true;
	}
	
	return false;
}

/*
  form a TDB_DATA for a record key
  caller frees

  note that the key for a record can depend on whether the
  dn refers to a case sensitive index record or not
*/
TDB_DATA ltdb_key_dn(struct ldb_module *module, TALLOC_CTX *mem_ctx,
		     struct ldb_dn *dn)
{
	TDB_DATA key;
	char *key_str = NULL;
	const char *dn_folded = NULL;

	/*
	  most DNs are case insensitive. The exception is index DNs for
	  case sensitive attributes

	  there are 3 cases dealt with in this code:

	  1) if the dn doesn't start with @ then uppercase the attribute
             names and the attributes values of case insensitive attributes
	  2) if the dn starts with @ then leave it alone -
	     the indexing code handles the rest
	*/

	dn_folded = ldb_dn_get_casefold(dn);
	if (!dn_folded) {
		goto failed;
	}

	key_str = talloc_strdup(mem_ctx, "DN=");
	if (!key_str) {
		goto failed;
	}

	key_str = talloc_strdup_append_buffer(key_str, dn_folded);
	if (!key_str) {
		goto failed;
	}

	key.dptr = (uint8_t *)key_str;
	key.dsize = strlen(key_str) + 1;

	return key;

failed:
	errno = ENOMEM;
	key.dptr = NULL;
	key.dsize = 0;
	return key;
}

/* The caller is to provide a correctly sized key */
int ltdb_guid_to_key(struct ldb_module *module,
		     struct ltdb_private *ltdb,
		     const struct ldb_val *GUID_val,
		     TDB_DATA *key)
{
	const char *GUID_prefix = LTDB_GUID_KEY_PREFIX;
	const int GUID_prefix_len = sizeof(LTDB_GUID_KEY_PREFIX) - 1;

	if (key->dsize != (GUID_val->length+GUID_prefix_len)) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	memcpy(key->dptr, GUID_prefix, GUID_prefix_len);
	memcpy(&key->dptr[GUID_prefix_len],
	       GUID_val->data, GUID_val->length);
	return LDB_SUCCESS;
}

/*
 * The caller is to provide a correctly sized key, used only in
 * the GUID index mode
 */
int ltdb_idx_to_key(struct ldb_module *module,
		    struct ltdb_private *ltdb,
		    TALLOC_CTX *mem_ctx,
		    const struct ldb_val *idx_val,
		    TDB_DATA *key)
{
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	struct ldb_dn *dn;

	if (ltdb->cache->GUID_index_attribute != NULL) {
		return ltdb_guid_to_key(module, ltdb,
					idx_val, key);
	}

	dn = ldb_dn_from_ldb_val(mem_ctx, ldb, idx_val);
	if (dn == NULL) {
		/*
		 * LDB_ERR_INVALID_DN_SYNTAX would just be confusing
		 * to the caller, as this in an invalid index value
		 */
		return LDB_ERR_OPERATIONS_ERROR;
	}
	/* form the key */
	*key = ltdb_key_dn(module, mem_ctx, dn);
	TALLOC_FREE(dn);
	if (!key->dptr) {
		return ldb_module_oom(module);
	}
	return LDB_SUCCESS;
}

/*
  form a TDB_DATA for a record key
  caller frees mem_ctx, which may or may not have the key
  as a child.

  note that the key for a record can depend on whether a
  GUID index is in use, or the DN is used as the key
*/
TDB_DATA ltdb_key_msg(struct ldb_module *module, TALLOC_CTX *mem_ctx,
		      const struct ldb_message *msg)
{
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	TDB_DATA key;
	const struct ldb_val *guid_val;
	int ret;

	if (ltdb->cache->GUID_index_attribute == NULL) {
		return ltdb_key_dn(module, mem_ctx, msg->dn);
	}

	if (ldb_dn_is_special(msg->dn)) {
		return ltdb_key_dn(module, mem_ctx, msg->dn);
	}

	guid_val = ldb_msg_find_ldb_val(msg,
				       ltdb->cache->GUID_index_attribute);
	if (guid_val == NULL) {
		ldb_asprintf_errstring(ldb_module_get_ctx(module),
				       "Did not find GUID attribute %s "
				       "in %s, required for TDB record "
				       "key in " LTDB_IDXGUID " mode.",
				       ltdb->cache->GUID_index_attribute,
				       ldb_dn_get_linearized(msg->dn));
		errno = EINVAL;
		key.dptr = NULL;
		key.dsize = 0;
		return key;
	}

	/* In this case, allocate with talloc */
	key.dptr = talloc_size(mem_ctx, LTDB_GUID_KEY_SIZE);
	if (key.dptr == NULL) {
		errno = ENOMEM;
		key.dptr = NULL;
		key.dsize = 0;
		return key;
	}
	key.dsize = talloc_get_size(key.dptr);

	ret = ltdb_guid_to_key(module, ltdb, guid_val, &key);

	if (ret != LDB_SUCCESS) {
		errno = EINVAL;
		key.dptr = NULL;
		key.dsize = 0;
		return key;
	}
	return key;
}

/*
  check special dn's have valid attributes
  currently only @ATTRIBUTES is checked
*/
static int ltdb_check_special_dn(struct ldb_module *module,
				 const struct ldb_message *msg)
{
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	unsigned int i, j;

	if (! ldb_dn_is_special(msg->dn) ||
	    ! ldb_dn_check_special(msg->dn, LTDB_ATTRIBUTES)) {
		return LDB_SUCCESS;
	}

	/* we have @ATTRIBUTES, let's check attributes are fine */
	/* should we check that we deny multivalued attributes ? */
	for (i = 0; i < msg->num_elements; i++) {
		if (ldb_attr_cmp(msg->elements[i].name, "distinguishedName") == 0) continue;

		for (j = 0; j < msg->elements[i].num_values; j++) {
			if (ltdb_check_at_attributes_values(&msg->elements[i].values[j]) != 0) {
				ldb_set_errstring(ldb, "Invalid attribute value in an @ATTRIBUTES entry");
				return LDB_ERR_INVALID_ATTRIBUTE_SYNTAX;
			}
		}
	}

	return LDB_SUCCESS;
}


/*
  we've made a modification to a dn - possibly reindex and
  update sequence number
*/
static int ltdb_modified(struct ldb_module *module, struct ldb_dn *dn)
{
	int ret = LDB_SUCCESS;
	struct ltdb_private *ltdb = talloc_get_type(ldb_module_get_private(module), struct ltdb_private);

	/* only allow modifies inside a transaction, otherwise the
	 * ldb is unsafe */
	if (ltdb->in_transaction == 0) {
		ldb_set_errstring(ldb_module_get_ctx(module), "ltdb modify without transaction");
		return LDB_ERR_OPERATIONS_ERROR;
	}

	if (ldb_dn_is_special(dn) &&
	    (ldb_dn_check_special(dn, LTDB_INDEXLIST) ||
	     ldb_dn_check_special(dn, LTDB_ATTRIBUTES)) )
	{
		if (ltdb->warn_reindex) {
			ldb_debug(ldb_module_get_ctx(module),
				LDB_DEBUG_ERROR, "Reindexing %s due to modification on %s",
				tdb_name(ltdb->tdb), ldb_dn_get_linearized(dn));
		}
		ret = ltdb_reindex(module);
	}

	/* If the modify was to a normal record, or any special except @BASEINFO, update the seq number */
	if (ret == LDB_SUCCESS &&
	    !(ldb_dn_is_special(dn) &&
	      ldb_dn_check_special(dn, LTDB_BASEINFO)) ) {
		ret = ltdb_increase_sequence_number(module);
	}

	/* If the modify was to @OPTIONS, reload the cache */
	if (ret == LDB_SUCCESS &&
	    ldb_dn_is_special(dn) &&
	    (ldb_dn_check_special(dn, LTDB_OPTIONS)) ) {
		ret = ltdb_cache_reload(module);
	}

	if (ret != LDB_SUCCESS) {
		ltdb->reindex_failed = true;
	}

	return ret;
}

/*
  store a record into the db
*/
int ltdb_store(struct ldb_module *module, const struct ldb_message *msg, int flgs)
{
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	TDB_DATA tdb_key, tdb_data;
	struct ldb_val ldb_data;
	int ret = LDB_SUCCESS;
	TALLOC_CTX *tdb_key_ctx = talloc_new(module);

	if (tdb_key_ctx == NULL) {
		return ldb_module_oom(module);
	}

	if (ltdb->read_only) {
		talloc_free(tdb_key_ctx);
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	tdb_key = ltdb_key_msg(module, tdb_key_ctx, msg);
	if (tdb_key.dptr == NULL) {
		TALLOC_FREE(tdb_key_ctx);
		return LDB_ERR_OTHER;
	}

	ret = ldb_pack_data(ldb_module_get_ctx(module),
			    msg, &ldb_data);
	if (ret == -1) {
		TALLOC_FREE(tdb_key_ctx);
		return LDB_ERR_OTHER;
	}

	tdb_data.dptr = ldb_data.data;
	tdb_data.dsize = ldb_data.length;

	ret = tdb_store(ltdb->tdb, tdb_key, tdb_data, flgs);
	if (ret != 0) {
		bool is_special = ldb_dn_is_special(msg->dn);
		ret = ltdb_err_map(tdb_error(ltdb->tdb));

		/*
		 * LDB_ERR_ENTRY_ALREADY_EXISTS means the DN, not
		 * the GUID, so re-map
		 */
		if (ret == LDB_ERR_ENTRY_ALREADY_EXISTS
		    && !is_special
		    && ltdb->cache->GUID_index_attribute != NULL) {
			ret = LDB_ERR_CONSTRAINT_VIOLATION;
		}
		goto done;
	}

done:
	TALLOC_FREE(tdb_key_ctx);
	talloc_free(ldb_data.data);

	return ret;
}


/*
  check if a attribute is a single valued, for a given element
 */
static bool ldb_tdb_single_valued(const struct ldb_schema_attribute *a,
				  struct ldb_message_element *el)
{
	if (!a) return false;
	if (el != NULL) {
		if (el->flags & LDB_FLAG_INTERNAL_FORCE_SINGLE_VALUE_CHECK) {
			/* override from a ldb module, for example
			   used for the description field, which is
			   marked multi-valued in the schema but which
			   should not actually accept multiple
			   values */
			return true;
		}
		if (el->flags & LDB_FLAG_INTERNAL_DISABLE_SINGLE_VALUE_CHECK) {
			/* override from a ldb module, for example used for
			   deleted linked attribute entries */
			return false;
		}
	}
	if (a->flags & LDB_ATTR_FLAG_SINGLE_VALUE) {
		return true;
	}
	return false;
}

static int ltdb_add_internal(struct ldb_module *module,
			     struct ltdb_private *ltdb,
			     const struct ldb_message *msg,
			     bool check_single_value)
{
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	int ret = LDB_SUCCESS;
	unsigned int i;
	bool valid_dn = false;

	/* Check the new DN is reasonable */
	valid_dn = ldb_dn_validate(msg->dn);
	if (valid_dn == false) {
		ldb_asprintf_errstring(ldb_module_get_ctx(module),
				       "Invalid DN in ADD: %s",
				       ldb_dn_get_linearized(msg->dn));
		return LDB_ERR_INVALID_DN_SYNTAX;
	}

	for (i=0;i<msg->num_elements;i++) {
		struct ldb_message_element *el = &msg->elements[i];
		const struct ldb_schema_attribute *a = ldb_schema_attribute_by_name(ldb, el->name);

		if (el->num_values == 0) {
			ldb_asprintf_errstring(ldb, "attribute '%s' on '%s' specified, but with 0 values (illegal)",
					       el->name, ldb_dn_get_linearized(msg->dn));
			return LDB_ERR_CONSTRAINT_VIOLATION;
		}
		if (check_single_value &&
				el->num_values > 1 &&
				ldb_tdb_single_valued(a, el)) {
			ldb_asprintf_errstring(ldb, "SINGLE-VALUE attribute %s on %s specified more than once",
					       el->name, ldb_dn_get_linearized(msg->dn));
			return LDB_ERR_CONSTRAINT_VIOLATION;
		}

		/* Do not check "@ATTRIBUTES" for duplicated values */
		if (ldb_dn_is_special(msg->dn) &&
		    ldb_dn_check_special(msg->dn, LTDB_ATTRIBUTES)) {
			continue;
		}

		if (check_single_value &&
		    !(el->flags &
		      LDB_FLAG_INTERNAL_DISABLE_SINGLE_VALUE_CHECK)) {
			struct ldb_val *duplicate = NULL;

			ret = ldb_msg_find_duplicate_val(ldb, discard_const(msg),
							 el, &duplicate, 0);
			if (ret != LDB_SUCCESS) {
				return ret;
			}
			if (duplicate != NULL) {
				ldb_asprintf_errstring(
					ldb,
					"attribute '%s': value '%.*s' on '%s' "
					"provided more than once in ADD object",
					el->name,
					(int)duplicate->length,
					duplicate->data,
					ldb_dn_get_linearized(msg->dn));
				return LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
			}
		}
	}

	ret = ltdb_store(module, msg, TDB_INSERT);
	if (ret != LDB_SUCCESS) {
		/*
		 * Try really hard to get the right error code for
		 * a re-add situation, as this can matter!
		 */
		if (ret == LDB_ERR_CONSTRAINT_VIOLATION) {
			int ret2;
			struct ldb_dn *dn2 = NULL;
			TALLOC_CTX *mem_ctx = talloc_new(module);
			if (mem_ctx == NULL) {
				return ldb_module_operr(module);
			}
			ret2 = ltdb_search_base(module, mem_ctx,
						msg->dn, &dn2);
			TALLOC_FREE(mem_ctx);
			if (ret2 == LDB_SUCCESS) {
				ret = LDB_ERR_ENTRY_ALREADY_EXISTS;
			}
		}
		if (ret == LDB_ERR_ENTRY_ALREADY_EXISTS) {
			ldb_asprintf_errstring(ldb,
					       "Entry %s already exists",
					       ldb_dn_get_linearized(msg->dn));
		}
		return ret;
	}

	ret = ltdb_index_add_new(module, ltdb, msg);
	if (ret != LDB_SUCCESS) {
		/*
		 * If we failed to index, delete the message again.
		 *
		 * This is particularly important for the GUID index
		 * case, which will only fail for a duplicate DN
		 * in the index add.
		 *
		 * Note that the caller may not cancel the transation
		 * and this means the above add might really show up!
		 */
		ltdb_delete_noindex(module, msg);
		return ret;
	}

	ret = ltdb_modified(module, msg->dn);

	return ret;
}

/*
  add a record to the database
*/
static int ltdb_add(struct ltdb_context *ctx)
{
	struct ldb_module *module = ctx->module;
	struct ldb_request *req = ctx->req;
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	int ret = LDB_SUCCESS;

	ret = ltdb_check_special_dn(module, req->op.add.message);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ldb_request_set_state(req, LDB_ASYNC_PENDING);

	if (ltdb_cache_load(module) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ltdb_add_internal(module, ltdb,
				req->op.add.message, true);

	return ret;
}

/*
  delete a record from the database, not updating indexes (used for deleting
  index records)
*/
int ltdb_delete_noindex(struct ldb_module *module,
			const struct ldb_message *msg)
{
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	TDB_DATA tdb_key;
	int ret;
	TALLOC_CTX *tdb_key_ctx = talloc_new(module);

	if (tdb_key_ctx == NULL) {
		return ldb_module_oom(module);
	}

	if (ltdb->read_only) {
		talloc_free(tdb_key_ctx);
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	tdb_key = ltdb_key_msg(module, tdb_key_ctx, msg);
	if (!tdb_key.dptr) {
		TALLOC_FREE(tdb_key_ctx);
		return LDB_ERR_OTHER;
	}

	ret = tdb_delete(ltdb->tdb, tdb_key);
	TALLOC_FREE(tdb_key_ctx);

	if (ret != 0) {
		ret = ltdb_err_map(tdb_error(ltdb->tdb));
	}

	return ret;
}

static int ltdb_delete_internal(struct ldb_module *module, struct ldb_dn *dn)
{
	struct ldb_message *msg;
	int ret = LDB_SUCCESS;

	msg = ldb_msg_new(module);
	if (msg == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/* in case any attribute of the message was indexed, we need
	   to fetch the old record */
	ret = ltdb_search_dn1(module, dn, msg, LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC);
	if (ret != LDB_SUCCESS) {
		/* not finding the old record is an error */
		goto done;
	}

	ret = ltdb_delete_noindex(module, msg);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

	/* remove any indexed attributes */
	ret = ltdb_index_delete(module, msg);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

	ret = ltdb_modified(module, dn);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

done:
	talloc_free(msg);
	return ret;
}

/*
  delete a record from the database
*/
static int ltdb_delete(struct ltdb_context *ctx)
{
	struct ldb_module *module = ctx->module;
	struct ldb_request *req = ctx->req;
	int ret = LDB_SUCCESS;

	ldb_request_set_state(req, LDB_ASYNC_PENDING);

	if (ltdb_cache_load(module) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ltdb_delete_internal(module, req->op.del.dn);

	return ret;
}

/*
  find an element by attribute name. At the moment this does a linear search,
  it should be re-coded to use a binary search once all places that modify
  records guarantee sorted order

  return the index of the first matching element if found, otherwise -1
*/
static int find_element(const struct ldb_message *msg, const char *name)
{
	unsigned int i;
	for (i=0;i<msg->num_elements;i++) {
		if (ldb_attr_cmp(msg->elements[i].name, name) == 0) {
			return i;
		}
	}
	return -1;
}


/*
  add an element to an existing record. Assumes a elements array that we
  can call re-alloc on, and assumed that we can re-use the data pointers from
  the passed in additional values. Use with care!

  returns 0 on success, -1 on failure (and sets errno)
*/
static int ltdb_msg_add_element(struct ldb_message *msg,
				struct ldb_message_element *el)
{
	struct ldb_message_element *e2;
	unsigned int i;

	if (el->num_values == 0) {
		/* nothing to do here - we don't add empty elements */
		return 0;
	}

	e2 = talloc_realloc(msg, msg->elements, struct ldb_message_element,
			      msg->num_elements+1);
	if (!e2) {
		errno = ENOMEM;
		return -1;
	}

	msg->elements = e2;

	e2 = &msg->elements[msg->num_elements];

	e2->name = el->name;
	e2->flags = el->flags;
	e2->values = talloc_array(msg->elements,
				  struct ldb_val, el->num_values);
	if (!e2->values) {
		errno = ENOMEM;
		return -1;
	}
	for (i=0;i<el->num_values;i++) {
		e2->values[i] = el->values[i];
	}
	e2->num_values = el->num_values;

	++msg->num_elements;

	return 0;
}

/*
  delete all elements having a specified attribute name
*/
static int msg_delete_attribute(struct ldb_module *module,
				struct ltdb_private *ltdb,
				struct ldb_message *msg, const char *name)
{
	unsigned int i;
	int ret;
	struct ldb_message_element *el;
	bool is_special = ldb_dn_is_special(msg->dn);

	if (!is_special
	    && ltdb->cache->GUID_index_attribute != NULL
	    && ldb_attr_cmp(name, ltdb->cache->GUID_index_attribute) == 0) {
		struct ldb_context *ldb = ldb_module_get_ctx(module);
		ldb_asprintf_errstring(ldb, "Must not modify GUID "
				       "attribute %s (used as DB index)",
				       ltdb->cache->GUID_index_attribute);
		return LDB_ERR_CONSTRAINT_VIOLATION;
	}

	el = ldb_msg_find_element(msg, name);
	if (el == NULL) {
		return LDB_ERR_NO_SUCH_ATTRIBUTE;
	}
	i = el - msg->elements;

	ret = ltdb_index_del_element(module, ltdb, msg, el);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	talloc_free(el->values);
	if (msg->num_elements > (i+1)) {
		memmove(el, el+1, sizeof(*el) * (msg->num_elements - (i+1)));
	}
	msg->num_elements--;
	msg->elements = talloc_realloc(msg, msg->elements,
				       struct ldb_message_element,
				       msg->num_elements);
	return LDB_SUCCESS;
}

/*
  delete all elements matching an attribute name/value

  return LDB Error on failure
*/
static int msg_delete_element(struct ldb_module *module,
			      struct ltdb_private *ltdb,
			      struct ldb_message *msg,
			      const char *name,
			      const struct ldb_val *val)
{
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	unsigned int i;
	int found, ret;
	struct ldb_message_element *el;
	const struct ldb_schema_attribute *a;

	found = find_element(msg, name);
	if (found == -1) {
		return LDB_ERR_NO_SUCH_ATTRIBUTE;
	}

	i = (unsigned int) found;
	el = &(msg->elements[i]);

	a = ldb_schema_attribute_by_name(ldb, el->name);

	for (i=0;i<el->num_values;i++) {
		bool matched;
		if (a->syntax->operator_fn) {
			ret = a->syntax->operator_fn(ldb, LDB_OP_EQUALITY, a,
						     &el->values[i], val, &matched);
			if (ret != LDB_SUCCESS) return ret;
		} else {
			matched = (a->syntax->comparison_fn(ldb, ldb,
							    &el->values[i], val) == 0);
		}
		if (matched) {
			if (el->num_values == 1) {
				return msg_delete_attribute(module,
							    ltdb, msg, name);
			}

			ret = ltdb_index_del_value(module, ltdb, msg, el, i);
			if (ret != LDB_SUCCESS) {
				return ret;
			}

			if (i<el->num_values-1) {
				memmove(&el->values[i], &el->values[i+1],
					sizeof(el->values[i])*
						(el->num_values-(i+1)));
			}
			el->num_values--;

			/* per definition we find in a canonicalised message an
			   attribute value only once. So we are finished here */
			return LDB_SUCCESS;
		}
	}

	/* Not found */
	return LDB_ERR_NO_SUCH_ATTRIBUTE;
}


/*
  modify a record - internal interface

  yuck - this is O(n^2). Luckily n is usually small so we probably
  get away with it, but if we ever have really large attribute lists
  then we'll need to look at this again

  'req' is optional, and is used to specify controls if supplied
*/
int ltdb_modify_internal(struct ldb_module *module,
			 const struct ldb_message *msg,
			 struct ldb_request *req)
{
	struct ldb_context *ldb = ldb_module_get_ctx(module);
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	struct ldb_message *msg2;
	unsigned int i, j;
	int ret = LDB_SUCCESS, idx;
	struct ldb_control *control_permissive = NULL;
	TALLOC_CTX *mem_ctx = talloc_new(req);

	if (mem_ctx == NULL) {
		return ldb_module_oom(module);
	}
	
	if (req) {
		control_permissive = ldb_request_get_control(req,
					LDB_CONTROL_PERMISSIVE_MODIFY_OID);
	}

	msg2 = ldb_msg_new(mem_ctx);
	if (msg2 == NULL) {
		ret = LDB_ERR_OTHER;
		goto done;
	}

	ret = ltdb_search_dn1(module, msg->dn,
			      msg2,
			      LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

	for (i=0; i<msg->num_elements; i++) {
		struct ldb_message_element *el = &msg->elements[i], *el2;
		struct ldb_val *vals;
		const struct ldb_schema_attribute *a = ldb_schema_attribute_by_name(ldb, el->name);
		const char *dn;
		uint32_t options = 0;
		if (control_permissive != NULL) {
			options |= LDB_MSG_FIND_COMMON_REMOVE_DUPLICATES;
		}

		switch (msg->elements[i].flags & LDB_FLAG_MOD_MASK) {
		case LDB_FLAG_MOD_ADD:

			if (el->num_values == 0) {
				ldb_asprintf_errstring(ldb,
						       "attribute '%s': attribute on '%s' specified, but with 0 values (illegal)",
						       el->name, ldb_dn_get_linearized(msg2->dn));
				ret = LDB_ERR_CONSTRAINT_VIOLATION;
				goto done;
			}

			/* make a copy of the array so that a permissive
			 * control can remove duplicates without changing the
			 * original values, but do not copy data as we do not
			 * need to keep it around once the operation is
			 * finished */
			if (control_permissive) {
				el = talloc(msg2, struct ldb_message_element);
				if (!el) {
					ret = LDB_ERR_OTHER;
					goto done;
				}
				*el = msg->elements[i];
				el->values = talloc_array(el, struct ldb_val, el->num_values);
				if (el->values == NULL) {
					ret = LDB_ERR_OTHER;
					goto done;
				}
				for (j = 0; j < el->num_values; j++) {
					el->values[j] = msg->elements[i].values[j];
				}
			}

			if (el->num_values > 1 && ldb_tdb_single_valued(a, el)) {
				ldb_asprintf_errstring(ldb, "SINGLE-VALUE attribute %s on %s specified more than once",
						       el->name, ldb_dn_get_linearized(msg2->dn));
				ret = LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
				goto done;
			}

			/* Checks if element already exists */
			idx = find_element(msg2, el->name);
			if (idx == -1) {
				if (ltdb_msg_add_element(msg2, el) != 0) {
					ret = LDB_ERR_OTHER;
					goto done;
				}
				ret = ltdb_index_add_element(module, ltdb,
							     msg2,
							     el);
				if (ret != LDB_SUCCESS) {
					goto done;
				}
			} else {
				j = (unsigned int) idx;
				el2 = &(msg2->elements[j]);

				/* We cannot add another value on a existing one
				   if the attribute is single-valued */
				if (ldb_tdb_single_valued(a, el)) {
					ldb_asprintf_errstring(ldb, "SINGLE-VALUE attribute %s on %s specified more than once",
						               el->name, ldb_dn_get_linearized(msg2->dn));
					ret = LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
					goto done;
				}

				/* Check that values don't exist yet on multi-
				   valued attributes or aren't provided twice */
				if (!(el->flags &
				      LDB_FLAG_INTERNAL_DISABLE_SINGLE_VALUE_CHECK)) {
					struct ldb_val *duplicate = NULL;
					ret = ldb_msg_find_common_values(ldb,
									 msg2,
									 el,
									 el2,
									 options);

					if (ret ==
					    LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS) {
						ldb_asprintf_errstring(ldb,
							"attribute '%s': value "
							"#%u on '%s' already "
							"exists", el->name, j,
							ldb_dn_get_linearized(msg2->dn));
						goto done;
					} else if (ret != LDB_SUCCESS) {
						goto done;
					}

					ret = ldb_msg_find_duplicate_val(
						ldb, msg2, el, &duplicate, 0);
					if (ret != LDB_SUCCESS) {
						goto done;
					}
					if (duplicate != NULL) {
						ldb_asprintf_errstring(
							ldb,
							"attribute '%s': value "
							"'%.*s' on '%s' "
							"provided more than "
							"once in ADD",
							el->name,
							(int)duplicate->length,
							duplicate->data,
							ldb_dn_get_linearized(msg->dn));
						ret = LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
						goto done;
					}
				}

				/* Now combine existing and new values to a new
				   attribute record */
				vals = talloc_realloc(msg2->elements,
						      el2->values, struct ldb_val,
						      el2->num_values + el->num_values);
				if (vals == NULL) {
					ldb_oom(ldb);
					ret = LDB_ERR_OTHER;
					goto done;
				}

				for (j=0; j<el->num_values; j++) {
					vals[el2->num_values + j] =
						ldb_val_dup(vals, &el->values[j]);
				}

				el2->values = vals;
				el2->num_values += el->num_values;

				ret = ltdb_index_add_element(module, ltdb,
							     msg2, el);
				if (ret != LDB_SUCCESS) {
					goto done;
				}
			}

			break;

		case LDB_FLAG_MOD_REPLACE:

			if (el->num_values > 1 && ldb_tdb_single_valued(a, el)) {
				ldb_asprintf_errstring(ldb, "SINGLE-VALUE attribute %s on %s specified more than once",
						       el->name, ldb_dn_get_linearized(msg2->dn));
				ret = LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
				goto done;
			}

			/*
			 * We don't need to check this if we have been
			 * pre-screened by the repl_meta_data module
			 * in Samba, or someone else who can claim to
			 * know what they are doing. 
			 */
			if (!(el->flags & LDB_FLAG_INTERNAL_DISABLE_SINGLE_VALUE_CHECK)) {
				struct ldb_val *duplicate = NULL;

				ret = ldb_msg_find_duplicate_val(ldb, msg2, el,
								 &duplicate, 0);
				if (ret != LDB_SUCCESS) {
					goto done;
				}
				if (duplicate != NULL) {
					ldb_asprintf_errstring(
						ldb,
						"attribute '%s': value '%.*s' "
						"on '%s' provided more than "
						"once in REPLACE",
						el->name,
						(int)duplicate->length,
						duplicate->data,
						ldb_dn_get_linearized(msg2->dn));
					ret = LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS;
					goto done;
				}
			}

			/* Checks if element already exists */
			idx = find_element(msg2, el->name);
			if (idx != -1) {
				j = (unsigned int) idx;
				el2 = &(msg2->elements[j]);

				/* we consider two elements to be
				 * equal only if the order
				 * matches. This allows dbcheck to
				 * fix the ordering on attributes
				 * where order matters, such as
				 * objectClass
				 */
				if (ldb_msg_element_equal_ordered(el, el2)) {
					continue;
				}

				/* Delete the attribute if it exists in the DB */
				if (msg_delete_attribute(module, ltdb,
							 msg2,
							 el->name) != 0) {
					ret = LDB_ERR_OTHER;
					goto done;
				}
			}

			/* Recreate it with the new values */
			if (ltdb_msg_add_element(msg2, el) != 0) {
				ret = LDB_ERR_OTHER;
				goto done;
			}

			ret = ltdb_index_add_element(module, ltdb,
						     msg2, el);
			if (ret != LDB_SUCCESS) {
				goto done;
			}

			break;

		case LDB_FLAG_MOD_DELETE:
			dn = ldb_dn_get_linearized(msg2->dn);
			if (dn == NULL) {
				ret = LDB_ERR_OTHER;
				goto done;
			}

			if (msg->elements[i].num_values == 0) {
				/* Delete the whole attribute */
				ret = msg_delete_attribute(module,
							   ltdb,
							   msg2,
							   msg->elements[i].name);
				if (ret == LDB_ERR_NO_SUCH_ATTRIBUTE &&
				    control_permissive) {
					ret = LDB_SUCCESS;
				} else {
					ldb_asprintf_errstring(ldb,
							       "attribute '%s': no such attribute for delete on '%s'",
							       msg->elements[i].name, dn);
				}
				if (ret != LDB_SUCCESS) {
					goto done;
				}
			} else {
				/* Delete specified values from an attribute */
				for (j=0; j < msg->elements[i].num_values; j++) {
					ret = msg_delete_element(module,
								 ltdb,
							         msg2,
							         msg->elements[i].name,
							         &msg->elements[i].values[j]);
					if (ret == LDB_ERR_NO_SUCH_ATTRIBUTE &&
					    control_permissive) {
						ret = LDB_SUCCESS;
					} else if (ret == LDB_ERR_NO_SUCH_ATTRIBUTE) {
						ldb_asprintf_errstring(ldb,
								       "attribute '%s': no matching attribute value while deleting attribute on '%s'",
								       msg->elements[i].name, dn);
					}
					if (ret != LDB_SUCCESS) {
						goto done;
					}
				}
			}
			break;
		default:
			ldb_asprintf_errstring(ldb,
					       "attribute '%s': invalid modify flags on '%s': 0x%x",
					       msg->elements[i].name, ldb_dn_get_linearized(msg->dn),
					       msg->elements[i].flags & LDB_FLAG_MOD_MASK);
			ret = LDB_ERR_PROTOCOL_ERROR;
			goto done;
		}
	}

	ret = ltdb_store(module, msg2, TDB_MODIFY);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

	ret = ltdb_modified(module, msg2->dn);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

done:
	TALLOC_FREE(mem_ctx);
	return ret;
}

/*
  modify a record
*/
static int ltdb_modify(struct ltdb_context *ctx)
{
	struct ldb_module *module = ctx->module;
	struct ldb_request *req = ctx->req;
	int ret = LDB_SUCCESS;

	ret = ltdb_check_special_dn(module, req->op.mod.message);
	if (ret != LDB_SUCCESS) {
		return ret;
	}

	ldb_request_set_state(req, LDB_ASYNC_PENDING);

	if (ltdb_cache_load(module) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ltdb_modify_internal(module, req->op.mod.message, req);

	return ret;
}

/*
  rename a record
*/
static int ltdb_rename(struct ltdb_context *ctx)
{
	struct ldb_module *module = ctx->module;
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	struct ldb_request *req = ctx->req;
	struct ldb_message *msg;
	int ret = LDB_SUCCESS;
	TDB_DATA tdb_key, tdb_key_old;
	struct ldb_dn *db_dn;
	bool valid_dn = false;

	ldb_request_set_state(req, LDB_ASYNC_PENDING);

	if (ltdb_cache_load(ctx->module) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	msg = ldb_msg_new(ctx);
	if (msg == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/* Check the new DN is reasonable */
	valid_dn = ldb_dn_validate(req->op.rename.newdn);
	if (valid_dn == false) {
		ldb_asprintf_errstring(ldb_module_get_ctx(module),
				       "Invalid New DN: %s",
				       ldb_dn_get_linearized(req->op.rename.newdn));
		return LDB_ERR_INVALID_DN_SYNTAX;
	}

	/* we need to fetch the old record to re-add under the new name */
	ret = ltdb_search_dn1(module, req->op.rename.olddn, msg,
			      LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC);
	if (ret == LDB_ERR_INVALID_DN_SYNTAX) {
		ldb_asprintf_errstring(ldb_module_get_ctx(module),
				       "Invalid Old DN: %s",
				       ldb_dn_get_linearized(req->op.rename.newdn));
		return ret;
	} else if (ret != LDB_SUCCESS) {
		/* not finding the old record is an error */
		return ret;
	}

	/* We need to, before changing the DB, check if the new DN
	 * exists, so we can return this error to the caller with an
	 * unmodified DB
	 *
	 * Even in GUID index mode we use ltdb_key_dn() as we are
	 * trying to figure out if this is just a case rename
	 */
	tdb_key = ltdb_key_dn(module, msg, req->op.rename.newdn);
	if (!tdb_key.dptr) {
		talloc_free(msg);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	tdb_key_old = ltdb_key_dn(module, msg, req->op.rename.olddn);
	if (!tdb_key_old.dptr) {
		talloc_free(msg);
		talloc_free(tdb_key.dptr);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/*
	 * Only declare a conflict if the new DN already exists,
	 * and it isn't a case change on the old DN
	 */
	if (tdb_key_old.dsize != tdb_key.dsize
	    || memcmp(tdb_key.dptr, tdb_key_old.dptr, tdb_key.dsize) != 0) {
		ret = ltdb_search_base(module, msg,
				       req->op.rename.newdn,
				       &db_dn);
		if (ret == LDB_SUCCESS) {
			ret = LDB_ERR_ENTRY_ALREADY_EXISTS;
		} else if (ret == LDB_ERR_NO_SUCH_OBJECT) {
			ret = LDB_SUCCESS;
		}
	}

	/* finding the new record already in the DB is an error */

	if (ret == LDB_ERR_ENTRY_ALREADY_EXISTS) {
		ldb_asprintf_errstring(ldb_module_get_ctx(module),
				       "Entry %s already exists",
				       ldb_dn_get_linearized(req->op.rename.newdn));
	}
	if (ret != LDB_SUCCESS) {
		talloc_free(tdb_key_old.dptr);
		talloc_free(tdb_key.dptr);
		talloc_free(msg);
		return ret;
	}

	talloc_free(tdb_key_old.dptr);
	talloc_free(tdb_key.dptr);

	/* Always delete first then add, to avoid conflicts with
	 * unique indexes. We rely on the transaction to make this
	 * atomic
	 */
	ret = ltdb_delete_internal(module, msg->dn);
	if (ret != LDB_SUCCESS) {
		talloc_free(msg);
		return ret;
	}

	msg->dn = ldb_dn_copy(msg, req->op.rename.newdn);
	if (msg->dn == NULL) {
		talloc_free(msg);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/* We don't check single value as we can have more than 1 with
	 * deleted attributes. We could go through all elements but that's
	 * maybe not the most efficient way
	 */
	ret = ltdb_add_internal(module, ltdb, msg, false);

	talloc_free(msg);

	return ret;
}

static int ltdb_start_trans(struct ldb_module *module)
{
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);

	/* Do not take out the transaction lock on a read-only DB */
	if (ltdb->read_only) {
		return LDB_ERR_UNWILLING_TO_PERFORM;
	}

	if (tdb_transaction_start(ltdb->tdb) != 0) {
		return ltdb_err_map(tdb_error(ltdb->tdb));
	}

	ltdb->in_transaction++;

	ltdb_index_transaction_start(module);

	ltdb->reindex_failed = false;

	return LDB_SUCCESS;
}

/*
 * Forward declaration to allow prepare_commit to in fact abort the
 * transaction
 */
static int ltdb_del_trans(struct ldb_module *module);

static int ltdb_prepare_commit(struct ldb_module *module)
{
	int ret;
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);

	if (ltdb->in_transaction != 1) {
		return LDB_SUCCESS;
	}

	/*
	 * Check if the last re-index failed.
	 *
	 * This can happen if for example a duplicate value was marked
	 * unique.  We must not write a partial re-index into the DB.
	 */
	if (ltdb->reindex_failed) {
		/*
		 * We must instead abort the transaction so we get the
		 * old values and old index back
		 */
		ltdb_del_trans(module);
		ldb_set_errstring(ldb_module_get_ctx(module),
				  "Failure during re-index, so "
				  "transaction must be aborted.");
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ltdb_index_transaction_commit(module);
	if (ret != LDB_SUCCESS) {
		tdb_transaction_cancel(ltdb->tdb);
		ltdb->in_transaction--;
		return ret;
	}

	if (tdb_transaction_prepare_commit(ltdb->tdb) != 0) {
		ret = ltdb_err_map(tdb_error(ltdb->tdb));
		ltdb->in_transaction--;
		ldb_debug_set(ldb_module_get_ctx(module),
			      LDB_DEBUG_FATAL,
			      "Failure during "
			      "tdb_transaction_prepare_commit(): %s -> %s",
			      tdb_errorstr(ltdb->tdb),
			      ldb_strerror(ret));
		return ret;
	}

	ltdb->prepared_commit = true;

	return LDB_SUCCESS;
}

static int ltdb_end_trans(struct ldb_module *module)
{
	int ret;
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);

	if (!ltdb->prepared_commit) {
		ret = ltdb_prepare_commit(module);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	ltdb->in_transaction--;
	ltdb->prepared_commit = false;

	if (tdb_transaction_commit(ltdb->tdb) != 0) {
		ret = ltdb_err_map(tdb_error(ltdb->tdb));
		ldb_asprintf_errstring(ldb_module_get_ctx(module),
				       "Failure during tdb_transaction_commit(): %s -> %s",
				       tdb_errorstr(ltdb->tdb),
				       ldb_strerror(ret));
		return ret;
	}

	return LDB_SUCCESS;
}

static int ltdb_del_trans(struct ldb_module *module)
{
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);

	ltdb->in_transaction--;

	if (ltdb_index_transaction_cancel(module) != 0) {
		tdb_transaction_cancel(ltdb->tdb);
		return ltdb_err_map(tdb_error(ltdb->tdb));
	}

	tdb_transaction_cancel(ltdb->tdb);
	return LDB_SUCCESS;
}

/*
  return sequenceNumber from @BASEINFO
*/
static int ltdb_sequence_number(struct ltdb_context *ctx,
				struct ldb_extended **ext)
{
	struct ldb_context *ldb;
	struct ldb_module *module = ctx->module;
	struct ldb_request *req = ctx->req;
	TALLOC_CTX *tmp_ctx = NULL;
	struct ldb_seqnum_request *seq;
	struct ldb_seqnum_result *res;
	struct ldb_message *msg = NULL;
	struct ldb_dn *dn;
	const char *date;
	int ret = LDB_SUCCESS;

	ldb = ldb_module_get_ctx(module);

	seq = talloc_get_type(req->op.extended.data,
				struct ldb_seqnum_request);
	if (seq == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ldb_request_set_state(req, LDB_ASYNC_PENDING);

	if (ltdb_lock_read(module) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	res = talloc_zero(req, struct ldb_seqnum_result);
	if (res == NULL) {
		ret = LDB_ERR_OPERATIONS_ERROR;
		goto done;
	}

	tmp_ctx = talloc_new(req);
	if (tmp_ctx == NULL) {
		ret = LDB_ERR_OPERATIONS_ERROR;
		goto done;
	}

	dn = ldb_dn_new(tmp_ctx, ldb, LTDB_BASEINFO);
	if (dn == NULL) {
		ret = LDB_ERR_OPERATIONS_ERROR;
		goto done;
	}

	msg = ldb_msg_new(tmp_ctx);
	if (msg == NULL) {
		ret = LDB_ERR_OPERATIONS_ERROR;
		goto done;
	}

	ret = ltdb_search_dn1(module, dn, msg, 0);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

	switch (seq->type) {
	case LDB_SEQ_HIGHEST_SEQ:
		res->seq_num = ldb_msg_find_attr_as_uint64(msg, LTDB_SEQUENCE_NUMBER, 0);
		break;
	case LDB_SEQ_NEXT:
		res->seq_num = ldb_msg_find_attr_as_uint64(msg, LTDB_SEQUENCE_NUMBER, 0);
		res->seq_num++;
		break;
	case LDB_SEQ_HIGHEST_TIMESTAMP:
		date = ldb_msg_find_attr_as_string(msg, LTDB_MOD_TIMESTAMP, NULL);
		if (date) {
			res->seq_num = ldb_string_to_time(date);
		} else {
			res->seq_num = 0;
			/* zero is as good as anything when we don't know */
		}
		break;
	}

	*ext = talloc_zero(req, struct ldb_extended);
	if (*ext == NULL) {
		ret = LDB_ERR_OPERATIONS_ERROR;
		goto done;
	}
	(*ext)->oid = LDB_EXTENDED_SEQUENCE_NUMBER;
	(*ext)->data = talloc_steal(*ext, res);

done:
	talloc_free(tmp_ctx);
	ltdb_unlock_read(module);
	return ret;
}

static void ltdb_request_done(struct ltdb_context *ctx, int error)
{
	struct ldb_context *ldb;
	struct ldb_request *req;
	struct ldb_reply *ares;

	ldb = ldb_module_get_ctx(ctx->module);
	req = ctx->req;

	/* if we already returned an error just return */
	if (ldb_request_get_status(req) != LDB_SUCCESS) {
		return;
	}

	ares = talloc_zero(req, struct ldb_reply);
	if (!ares) {
		ldb_oom(ldb);
		req->callback(req, NULL);
		return;
	}
	ares->type = LDB_REPLY_DONE;
	ares->error = error;

	req->callback(req, ares);
}

static void ltdb_timeout(struct tevent_context *ev,
			  struct tevent_timer *te,
			  struct timeval t,
			  void *private_data)
{
	struct ltdb_context *ctx;
	ctx = talloc_get_type(private_data, struct ltdb_context);

	if (!ctx->request_terminated) {
		/* request is done now */
		ltdb_request_done(ctx, LDB_ERR_TIME_LIMIT_EXCEEDED);
	}

	if (ctx->spy) {
		/* neutralize the spy */
		ctx->spy->ctx = NULL;
		ctx->spy = NULL;
	}
	talloc_free(ctx);
}

static void ltdb_request_extended_done(struct ltdb_context *ctx,
					struct ldb_extended *ext,
					int error)
{
	struct ldb_context *ldb;
	struct ldb_request *req;
	struct ldb_reply *ares;

	ldb = ldb_module_get_ctx(ctx->module);
	req = ctx->req;

	/* if we already returned an error just return */
	if (ldb_request_get_status(req) != LDB_SUCCESS) {
		return;
	}

	ares = talloc_zero(req, struct ldb_reply);
	if (!ares) {
		ldb_oom(ldb);
		req->callback(req, NULL);
		return;
	}
	ares->type = LDB_REPLY_DONE;
	ares->response = ext;
	ares->error = error;

	req->callback(req, ares);
}

static void ltdb_handle_extended(struct ltdb_context *ctx)
{
	struct ldb_extended *ext = NULL;
	int ret;

	if (strcmp(ctx->req->op.extended.oid,
		   LDB_EXTENDED_SEQUENCE_NUMBER) == 0) {
		/* get sequence number */
		ret = ltdb_sequence_number(ctx, &ext);
	} else {
		/* not recognized */
		ret = LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION;
	}

	ltdb_request_extended_done(ctx, ext, ret);
}

static void ltdb_callback(struct tevent_context *ev,
			  struct tevent_timer *te,
			  struct timeval t,
			  void *private_data)
{
	struct ltdb_context *ctx;
	int ret;

	ctx = talloc_get_type(private_data, struct ltdb_context);

	if (ctx->request_terminated) {
		goto done;
	}

	switch (ctx->req->operation) {
	case LDB_SEARCH:
		ret = ltdb_search(ctx);
		break;
	case LDB_ADD:
		ret = ltdb_add(ctx);
		break;
	case LDB_MODIFY:
		ret = ltdb_modify(ctx);
		break;
	case LDB_DELETE:
		ret = ltdb_delete(ctx);
		break;
	case LDB_RENAME:
		ret = ltdb_rename(ctx);
		break;
	case LDB_EXTENDED:
		ltdb_handle_extended(ctx);
		goto done;
	default:
		/* no other op supported */
		ret = LDB_ERR_PROTOCOL_ERROR;
	}

	if (!ctx->request_terminated) {
		/* request is done now */
		ltdb_request_done(ctx, ret);
	}

done:
	if (ctx->spy) {
		/* neutralize the spy */
		ctx->spy->ctx = NULL;
		ctx->spy = NULL;
	}
	talloc_free(ctx);
}

static int ltdb_request_destructor(void *ptr)
{
	struct ltdb_req_spy *spy = talloc_get_type(ptr, struct ltdb_req_spy);

	if (spy->ctx != NULL) {
		spy->ctx->spy = NULL;
		spy->ctx->request_terminated = true;
		spy->ctx = NULL;
	}

	return 0;
}

static int ltdb_handle_request(struct ldb_module *module,
			       struct ldb_request *req)
{
	struct ldb_control *control_permissive;
	struct ldb_context *ldb;
	struct tevent_context *ev;
	struct ltdb_context *ac;
	struct tevent_timer *te;
	struct timeval tv;
	unsigned int i;

	ldb = ldb_module_get_ctx(module);

	control_permissive = ldb_request_get_control(req,
					LDB_CONTROL_PERMISSIVE_MODIFY_OID);

	for (i = 0; req->controls && req->controls[i]; i++) {
		if (req->controls[i]->critical &&
		    req->controls[i] != control_permissive) {
			ldb_asprintf_errstring(ldb, "Unsupported critical extension %s",
					       req->controls[i]->oid);
			return LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION;
		}
	}

	if (req->starttime == 0 || req->timeout == 0) {
		ldb_set_errstring(ldb, "Invalid timeout settings");
		return LDB_ERR_TIME_LIMIT_EXCEEDED;
	}

	ev = ldb_handle_get_event_context(req->handle);

	ac = talloc_zero(ldb, struct ltdb_context);
	if (ac == NULL) {
		ldb_oom(ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ac->module = module;
	ac->req = req;

	tv.tv_sec = 0;
	tv.tv_usec = 0;
	te = tevent_add_timer(ev, ac, tv, ltdb_callback, ac);
	if (NULL == te) {
		talloc_free(ac);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	if (req->timeout > 0) {
		tv.tv_sec = req->starttime + req->timeout;
		tv.tv_usec = 0;
		ac->timeout_event = tevent_add_timer(ev, ac, tv,
						     ltdb_timeout, ac);
		if (NULL == ac->timeout_event) {
			talloc_free(ac);
			return LDB_ERR_OPERATIONS_ERROR;
		}
	}

	/* set a spy so that we do not try to use the request context
	 * if it is freed before ltdb_callback fires */
	ac->spy = talloc(req, struct ltdb_req_spy);
	if (NULL == ac->spy) {
		talloc_free(ac);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	ac->spy->ctx = ac;

	talloc_set_destructor((TALLOC_CTX *)ac->spy, ltdb_request_destructor);

	return LDB_SUCCESS;
}

static int ltdb_init_rootdse(struct ldb_module *module)
{
	/* ignore errors on this - we expect it for non-sam databases */
	ldb_mod_register_control(module, LDB_CONTROL_PERMISSIVE_MODIFY_OID);

	/* there can be no module beyond the backend, just return */
	return LDB_SUCCESS;
}

static const struct ldb_module_ops ltdb_ops = {
	.name              = "tdb",
	.init_context      = ltdb_init_rootdse,
	.search            = ltdb_handle_request,
	.add               = ltdb_handle_request,
	.modify            = ltdb_handle_request,
	.del               = ltdb_handle_request,
	.rename            = ltdb_handle_request,
	.extended          = ltdb_handle_request,
	.start_transaction = ltdb_start_trans,
	.end_transaction   = ltdb_end_trans,
	.prepare_commit    = ltdb_prepare_commit,
	.del_transaction   = ltdb_del_trans,
	.read_lock         = ltdb_lock_read,
	.read_unlock       = ltdb_unlock_read,
};

/*
  connect to the database
*/
static int ltdb_connect(struct ldb_context *ldb, const char *url,
			unsigned int flags, const char *options[],
			struct ldb_module **_module)
{
	struct ldb_module *module;
	const char *path;
	int tdb_flags, open_flags;
	struct ltdb_private *ltdb;

	/*
	 * We hold locks, so we must use a private event context
	 * on each returned handle
	 */

	ldb_set_require_private_event_context(ldb);

	/* parse the url */
	if (strchr(url, ':')) {
		if (strncmp(url, "tdb://", 6) != 0) {
			ldb_debug(ldb, LDB_DEBUG_ERROR,
				  "Invalid tdb URL '%s'", url);
			return LDB_ERR_OPERATIONS_ERROR;
		}
		path = url+6;
	} else {
		path = url;
	}

	tdb_flags = TDB_DEFAULT | TDB_SEQNUM;

	/* check for the 'nosync' option */
	if (flags & LDB_FLG_NOSYNC) {
		tdb_flags |= TDB_NOSYNC;
	}

	/* and nommap option */
	if (flags & LDB_FLG_NOMMAP) {
		tdb_flags |= TDB_NOMMAP;
	}

	ltdb = talloc_zero(ldb, struct ltdb_private);
	if (!ltdb) {
		ldb_oom(ldb);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	if (flags & LDB_FLG_RDONLY) {
		/*
		 * This is weird, but because we can only have one tdb
		 * in this process, and the other one could be
		 * read-write, we can't use the tdb readonly.  Plus a
		 * read only tdb prohibits the all-record lock.
		 */
		open_flags = O_RDWR;

		ltdb->read_only = true;

	} else if (flags & LDB_FLG_DONT_CREATE_DB) {
		/*
		 * This is used by ldbsearch to prevent creation of the database
		 * if the name is wrong
		 */
		open_flags = O_RDWR;
	} else {
		/*
		 * This is the normal case
		 */
		open_flags = O_CREAT | O_RDWR;
	}

	/* note that we use quite a large default hash size */
	ltdb->tdb = ltdb_wrap_open(ltdb, path, 10000,
				   tdb_flags, open_flags,
				   ldb_get_create_perms(ldb), ldb);
	if (!ltdb->tdb) {
		ldb_asprintf_errstring(ldb,
				       "Unable to open tdb '%s': %s", path, strerror(errno));
		ldb_debug(ldb, LDB_DEBUG_ERROR,
			  "Unable to open tdb '%s': %s", path, strerror(errno));
		talloc_free(ltdb);
		if (errno == EACCES || errno == EPERM) {
			return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
		}
		return LDB_ERR_OPERATIONS_ERROR;
	}

	if (getenv("LDB_WARN_UNINDEXED")) {
		ltdb->warn_unindexed = true;
	}

	if (getenv("LDB_WARN_REINDEX")) {
		ltdb->warn_reindex = true;
	}

	ltdb->sequence_number = 0;

	/*
	 * Override full DB scans
	 *
	 * A full DB scan is expensive on a large database.  This
	 * option is for testing to show that the full DB scan is not
	 * triggered.
	 */
	{
		const char *len_str =
			ldb_options_find(ldb, options,
					 "disable_full_db_scan_for_self_test");
		if (len_str != NULL) {
			ltdb->disable_full_db_scan = true;
		}
	}

	module = ldb_module_new(ldb, ldb, "ldb_tdb backend", &ltdb_ops);
	if (!module) {
		ldb_oom(ldb);
		talloc_free(ltdb);
		return LDB_ERR_OPERATIONS_ERROR;
	}
	ldb_module_set_private(module, ltdb);
	talloc_steal(module, ltdb);

	if (ltdb_cache_load(module) != 0) {
		ldb_asprintf_errstring(ldb,
				       "Unable to load ltdb cache records of tdb '%s'", path);
		talloc_free(module);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	*_module = module;
	return LDB_SUCCESS;
}

int ldb_tdb_init(const char *version)
{
	LDB_MODULE_CHECK_VERSION(version);
	return ldb_register_backend("tdb", ltdb_connect, false);
}