aboutsummaryrefslogtreecommitdiffstats
path: root/lib/ldb/ldb_tdb/ldb_search.c
blob: d14be0febd435ce3bd9fd701116d831379a31960 (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
/* 
   ldb database library

   Copyright (C) Andrew Tridgell  2004

     ** 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
 *
 *  Component: ldb search functions
 *
 *  Description: functions to search ldb+tdb databases
 *
 *  Author: Andrew Tridgell
 */

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

/*
  add one element to a message
*/
static int msg_add_element(struct ldb_message *ret, 
			   const struct ldb_message_element *el,
			   int check_duplicates)
{
	unsigned int i;
	struct ldb_message_element *e2, *elnew;

	if (check_duplicates && ldb_msg_find_element(ret, el->name)) {
		/* its already there */
		return 0;
	}

	e2 = talloc_realloc(ret, ret->elements, struct ldb_message_element, ret->num_elements+1);
	if (!e2) {
		return -1;
	}
	ret->elements = e2;
	
	elnew = &e2[ret->num_elements];

	elnew->name = talloc_strdup(ret->elements, el->name);
	if (!elnew->name) {
		return -1;
	}

	if (el->num_values) {
		elnew->values = talloc_array(ret->elements, struct ldb_val, el->num_values);
		if (!elnew->values) {
			return -1;
		}
	} else {
		elnew->values = NULL;
	}

	for (i=0;i<el->num_values;i++) {
		elnew->values[i] = ldb_val_dup(elnew->values, &el->values[i]);
		if (elnew->values[i].length != el->values[i].length) {
			return -1;
		}
	}

	elnew->num_values = el->num_values;
	elnew->flags = el->flags;

	ret->num_elements++;

	return 0;
}

/*
  add the special distinguishedName element
*/
static int msg_add_distinguished_name(struct ldb_message *msg)
{
	struct ldb_message_element el;
	struct ldb_val val;
	int ret;

	el.flags = 0;
	el.name = "distinguishedName";
	el.num_values = 1;
	el.values = &val;
	el.flags = 0;
	val.data = (uint8_t *)ldb_dn_alloc_linearized(msg, msg->dn);
	if (val.data == NULL) {
		return -1;
	}
	val.length = strlen((char *)val.data);

	ret = msg_add_element(msg, &el, 1);
	return ret;
}

/*
  search the database for a single simple dn.
  return LDB_ERR_NO_SUCH_OBJECT on record-not-found
  and LDB_SUCCESS on success
*/
int ltdb_search_base(struct ldb_module *module,
		     TALLOC_CTX *mem_ctx,
		     struct ldb_dn *dn,
		     struct ldb_dn **ret_dn)
{
	int exists;
	int ret;
	struct ldb_message *msg = NULL;

	if (ldb_dn_is_null(dn)) {
		return LDB_ERR_NO_SUCH_OBJECT;
	}

	/*
	 * We can't use tdb_exists() directly on a key when the TDB
	 * key is the GUID one, not the DN based one.  So we just do a
	 * normal search and avoid most of the allocation with the
	 * LDB_UNPACK_DATA_FLAG_NO_DN and
	 * LDB_UNPACK_DATA_FLAG_NO_ATTRS flags
	 */
	msg = ldb_msg_new(module);
	if (msg == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ltdb_search_dn1(module, dn,
			      msg,
			      LDB_UNPACK_DATA_FLAG_NO_ATTRS);
	if (ret == LDB_SUCCESS) {
		const char *dn_linearized
			= ldb_dn_get_linearized(dn);
		const char *msg_dn_linearlized
			= ldb_dn_get_linearized(msg->dn);

		if (strcmp(dn_linearized, msg_dn_linearlized) == 0) {
			/*
			 * Re-use the full incoming DN for
			 * subtree checks
			 */
			*ret_dn = dn;
		} else {
			/*
			 * Use the string DN from the unpack, so that
			 * we have a case-exact match of the base
			 */
			*ret_dn = talloc_steal(mem_ctx, msg->dn);
		}
		exists = true;
	} else if (ret == LDB_ERR_NO_SUCH_OBJECT) {
		exists = false;
	} else {
		talloc_free(msg);
		return ret;
	}
	talloc_free(msg);
	if (exists) {
		return LDB_SUCCESS;
	}
	return LDB_ERR_NO_SUCH_OBJECT;
}

struct ltdb_parse_data_unpack_ctx {
	struct ldb_message *msg;
	struct ldb_module *module;
	unsigned int unpack_flags;
};

static int ltdb_parse_data_unpack(TDB_DATA key, TDB_DATA data,
				  void *private_data)
{
	struct ltdb_parse_data_unpack_ctx *ctx = private_data;
	unsigned int nb_elements_in_db;
	int ret;
	struct ldb_context *ldb = ldb_module_get_ctx(ctx->module);
	struct ldb_val data_parse = {
		.data = data.dptr,
		.length = data.dsize
	};

	if (ctx->unpack_flags & LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC) {
		/*
		 * If we got LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC
		 * we need at least do a memdup on the whole
		 * data buffer as that may change later
		 * and the caller needs a stable result.
		 */
		data_parse.data = talloc_memdup(ctx->msg,
						data.dptr,
						data.dsize);
		if (data_parse.data == NULL) {
			ldb_debug(ldb, LDB_DEBUG_ERROR,
				  "Unable to allocate data(%d) for %*.*s\n",
				  (int)data.dsize,
				  (int)key.dsize, (int)key.dsize, key.dptr);
			return LDB_ERR_OPERATIONS_ERROR;
		}
	}

	ret = ldb_unpack_data_only_attr_list_flags(ldb, &data_parse,
						   ctx->msg,
						   NULL, 0,
						   ctx->unpack_flags,
						   &nb_elements_in_db);
	if (ret == -1) {
		if (data_parse.data != data.dptr) {
			talloc_free(data_parse.data);
		}

		ldb_debug(ldb, LDB_DEBUG_ERROR, "Invalid data for index %*.*s\n",
			  (int)key.dsize, (int)key.dsize, key.dptr);
		return LDB_ERR_OPERATIONS_ERROR;		
	}
	return ret;
}

/*
  search the database for a single simple dn, returning all attributes
  in a single message

  return LDB_ERR_NO_SUCH_OBJECT on record-not-found
  and LDB_SUCCESS on success
*/
int ltdb_search_key(struct ldb_module *module, struct ltdb_private *ltdb,
		    const struct TDB_DATA tdb_key,
		    struct ldb_message *msg,
		    unsigned int unpack_flags)
{
	int ret;
	struct ltdb_parse_data_unpack_ctx ctx = {
		.msg = msg,
		.module = module,
		.unpack_flags = unpack_flags
	};

	memset(msg, 0, sizeof(*msg));

	msg->num_elements = 0;
	msg->elements = NULL;

	ret = tdb_parse_record(ltdb->tdb, tdb_key, 
			       ltdb_parse_data_unpack, &ctx); 
	
	if (ret == -1) {
		ret = ltdb_err_map(tdb_error(ltdb->tdb));
		if (ret == LDB_SUCCESS) {
			/*
			 * Just to be sure we don't turn errors
			 * into success
			 */
			return LDB_ERR_OPERATIONS_ERROR;
		}
		return ret;
	} else if (ret != LDB_SUCCESS) {
		return ret;
	}

	return LDB_SUCCESS;
}

/*
  search the database for a single simple dn, returning all attributes
  in a single message

  return LDB_ERR_NO_SUCH_OBJECT on record-not-found
  and LDB_SUCCESS on success
*/
int ltdb_search_dn1(struct ldb_module *module, struct ldb_dn *dn, struct ldb_message *msg,
		    unsigned int unpack_flags)
{
	void *data = ldb_module_get_private(module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	int ret;
	uint8_t guid_key[LTDB_GUID_KEY_SIZE];
	TDB_DATA tdb_key = {
		.dptr = guid_key,
		.dsize = sizeof(guid_key)
	};
	TALLOC_CTX *tdb_key_ctx = NULL;

	bool valid_dn = ldb_dn_validate(dn);
	if (valid_dn == false) {
		ldb_asprintf_errstring(ldb_module_get_ctx(module),
				       "Invalid Base DN: %s",
				       ldb_dn_get_linearized(dn));
		return LDB_ERR_INVALID_DN_SYNTAX;
	}

	if (ltdb->cache->GUID_index_attribute == NULL) {
		tdb_key_ctx = talloc_new(msg);
		if (!tdb_key_ctx) {
			return ldb_module_oom(module);
		}

		/* form the key */
		tdb_key = ltdb_key_dn(module, tdb_key_ctx, dn);
		if (!tdb_key.dptr) {
			TALLOC_FREE(tdb_key_ctx);
			return LDB_ERR_OPERATIONS_ERROR;
		}
	} else if (ldb_dn_is_special(dn)) {
		tdb_key_ctx = talloc_new(msg);
		if (!tdb_key_ctx) {
			return ldb_module_oom(module);
		}

		/* form the key */
		tdb_key = ltdb_key_dn(module, tdb_key_ctx, dn);
		if (!tdb_key.dptr) {
			TALLOC_FREE(tdb_key_ctx);
			return LDB_ERR_OPERATIONS_ERROR;
		}
	} else {
		/*
		 * Look in the index to find the key for this DN.
		 *
		 * the tdb_key memory is allocated above, msg is just
		 * used for internal memory.
		 *
		 */
		ret = ltdb_key_dn_from_idx(module, ltdb,
					   msg,
					   dn, &tdb_key);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	ret = ltdb_search_key(module, ltdb, tdb_key, msg, unpack_flags);

	TALLOC_FREE(tdb_key_ctx);

	if (ret != LDB_SUCCESS) {
		return ret;
	}

	if ((unpack_flags & LDB_UNPACK_DATA_FLAG_NO_DN) == 0) {
		if (!msg->dn) {
			msg->dn = ldb_dn_copy(msg, dn);
		}
		if (!msg->dn) {
			return LDB_ERR_OPERATIONS_ERROR;
		}
	}

	return LDB_SUCCESS;
}

/*
  filter the specified list of attributes from a message
  removing not requested attrs from the new message constructed.

  The reason this makes a new message is that the old one may not be
  individually allocated, which is what our callers expect.

 */
int ltdb_filter_attrs(TALLOC_CTX *mem_ctx,
		      const struct ldb_message *msg, const char * const *attrs,
		      struct ldb_message **filtered_msg)
{
	unsigned int i;
	bool keep_all = false;
	bool add_dn = false;
	uint32_t num_elements;
	uint32_t elements_size;
	struct ldb_message *msg2;

	msg2 = ldb_msg_new(mem_ctx);
	if (msg2 == NULL) {
		goto failed;
	}

	msg2->dn = ldb_dn_copy(msg2, msg->dn);
	if (msg2->dn == NULL) {
		goto failed;
	}

	if (attrs) {
		/* check for special attrs */
		for (i = 0; attrs[i]; i++) {
			int cmp = strcmp(attrs[i], "*");
			if (cmp == 0) {
				keep_all = true;
				break;
			}
			cmp = ldb_attr_cmp(attrs[i], "distinguishedName");
			if (cmp == 0) {
				add_dn = true;
			}
		}
	} else {
		keep_all = true;
	}

	if (keep_all) {
		add_dn = true;
		elements_size = msg->num_elements + 1;

	/* Shortcuts for the simple cases */
	} else if (add_dn && i == 1) {
		if (msg_add_distinguished_name(msg2) != 0) {
			goto failed;
		}
		*filtered_msg = msg2;
		return 0;
	} else if (i == 0) {
		*filtered_msg = msg2;
		return 0;

	/* Otherwise we are copying at most as many element as we have attributes */
	} else {
		elements_size = i;
	}

	msg2->elements = talloc_array(msg2, struct ldb_message_element,
				      elements_size);
	if (msg2->elements == NULL) goto failed;

	num_elements = 0;

	for (i = 0; i < msg->num_elements; i++) {
		struct ldb_message_element *el = &msg->elements[i];
		struct ldb_message_element *el2 = &msg2->elements[num_elements];
		unsigned int j;

		if (keep_all == false) {
			bool found = false;
			for (j = 0; attrs[j]; j++) {
				int cmp = ldb_attr_cmp(el->name, attrs[j]);
				if (cmp == 0) {
					found = true;
					break;
				}
			}
			if (found == false) {
				continue;
			}
		}
		*el2 = *el;
		el2->name = talloc_strdup(msg2->elements, el->name);
		if (el2->name == NULL) {
			goto failed;
		}
		el2->values = talloc_array(msg2->elements, struct ldb_val, el->num_values);
		if (el2->values == NULL) {
			goto failed;
		}
		for (j=0;j<el->num_values;j++) {
			el2->values[j] = ldb_val_dup(el2->values, &el->values[j]);
			if (el2->values[j].data == NULL && el->values[j].length != 0) {
				goto failed;
			}
		}
		num_elements++;

		/* Pidginhole principle: we can't have more elements
		 * than the number of attributes if they are unique in
		 * the DB */
		if (num_elements > elements_size) {
			goto failed;
		}
	}

	msg2->num_elements = num_elements;

	if (add_dn) {
		if (msg_add_distinguished_name(msg2) != 0) {
			goto failed;
		}
	}

	if (msg2->num_elements > 0) {
		msg2->elements = talloc_realloc(msg2, msg2->elements,
						struct ldb_message_element,
						msg2->num_elements);
		if (msg2->elements == NULL) {
			goto failed;
		}
	} else {
		talloc_free(msg2->elements);
		msg2->elements = NULL;
	}

	*filtered_msg = msg2;

	return 0;
failed:
	TALLOC_FREE(msg2);
	return -1;
}

/*
  search function for a non-indexed search
 */
static int search_func(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data, void *state)
{
	struct ldb_context *ldb;
	struct ltdb_context *ac;
	struct ldb_message *msg, *filtered_msg;
	const struct ldb_val val = {
		.data = data.dptr,
		.length = data.dsize,
	};
	int ret;
	bool matched;
	unsigned int nb_elements_in_db;

	ac = talloc_get_type(state, struct ltdb_context);
	ldb = ldb_module_get_ctx(ac->module);

	if (ltdb_key_is_record(key) == false) {
		return 0;
	}

	msg = ldb_msg_new(ac);
	if (!msg) {
		ac->error = LDB_ERR_OPERATIONS_ERROR;
		return -1;
	}

	/* unpack the record */
	ret = ldb_unpack_data_only_attr_list_flags(ldb, &val,
						   msg,
						   NULL, 0,
						   LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC|
						   LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC,
						   &nb_elements_in_db);
	if (ret == -1) {
		talloc_free(msg);
		ac->error = LDB_ERR_OPERATIONS_ERROR;
		return -1;
	}

	if (!msg->dn) {
		msg->dn = ldb_dn_new(msg, ldb,
				     (char *)key.dptr + 3);
		if (msg->dn == NULL) {
			talloc_free(msg);
			ac->error = LDB_ERR_OPERATIONS_ERROR;
			return -1;
		}
	}

	/* see if it matches the given expression */
	ret = ldb_match_msg_error(ldb, msg,
				  ac->tree, ac->base, ac->scope, &matched);
	if (ret != LDB_SUCCESS) {
		talloc_free(msg);
		ac->error = LDB_ERR_OPERATIONS_ERROR;
		return -1;
	}
	if (!matched) {
		talloc_free(msg);
		return 0;
	}

	/* filter the attributes that the user wants */
	ret = ltdb_filter_attrs(ac, msg, ac->attrs, &filtered_msg);
	talloc_free(msg);

	if (ret == -1) {
		ac->error = LDB_ERR_OPERATIONS_ERROR;
		return -1;
	}

	ret = ldb_module_send_entry(ac->req, filtered_msg, NULL);
	if (ret != LDB_SUCCESS) {
		ac->request_terminated = true;
		/* the callback failed, abort the operation */
		ac->error = LDB_ERR_OPERATIONS_ERROR;
		return -1;
	}

	return 0;
}


/*
  search the database with a LDAP-like expression.
  this is the "full search" non-indexed variant
*/
static int ltdb_search_full(struct ltdb_context *ctx)
{
	void *data = ldb_module_get_private(ctx->module);
	struct ltdb_private *ltdb = talloc_get_type(data, struct ltdb_private);
	int ret;

	ctx->error = LDB_SUCCESS;
	if (ltdb->in_transaction != 0) {
		ret = tdb_traverse(ltdb->tdb, search_func, ctx);
	} else {
		ret = tdb_traverse_read(ltdb->tdb, search_func, ctx);
	}

	if (ret < 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	return ctx->error;
}

static int ltdb_search_and_return_base(struct ltdb_private *ltdb,
				       struct ltdb_context *ctx)
{
	struct ldb_message *msg, *filtered_msg;
	struct ldb_context *ldb = ldb_module_get_ctx(ctx->module);
	const char *dn_linearized;
	const char *msg_dn_linearlized;
	int ret;
	bool matched;

	msg = ldb_msg_new(ctx);
	if (!msg) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	ret = ltdb_search_dn1(ctx->module, ctx->base, msg,
			      LDB_UNPACK_DATA_FLAG_NO_DATA_ALLOC|
			      LDB_UNPACK_DATA_FLAG_NO_VALUES_ALLOC);

	if (ret == LDB_ERR_NO_SUCH_OBJECT) {
		if (ltdb->check_base == false) {
			/*
			 * In this case, we are done, as no base
			 * checking is allowed in this DB
			 */
			talloc_free(msg);
			return LDB_SUCCESS;
		}
		ldb_asprintf_errstring(ldb,
				       "No such Base DN: %s",
				       ldb_dn_get_linearized(ctx->base));
	}
	if (ret != LDB_SUCCESS) {
		talloc_free(msg);
		return ret;
	}


	/*
	 * We use this, not ldb_match_msg_error() as we know
	 * we matched on the scope BASE, as we just fetched
	 * the base DN
	 */

	ret = ldb_match_message(ldb, msg,
				ctx->tree,
				ctx->scope,
				&matched);
	if (ret != LDB_SUCCESS) {
		talloc_free(msg);
		return ret;
	}
	if (!matched) {
		talloc_free(msg);
		return LDB_SUCCESS;
	}

	dn_linearized = ldb_dn_get_linearized(ctx->base);
	msg_dn_linearlized = ldb_dn_get_linearized(msg->dn);

	if (strcmp(dn_linearized, msg_dn_linearlized) == 0) {
		/*
		 * If the DN is exactly the same string, then
		 * re-use the full incoming DN for the
		 * returned result, as it has already been
		 * casefolded
		 */
		msg->dn = ctx->base;
	}

	/*
	 * filter the attributes that the user wants.
	 *
	 * This copies msg->dn including the casefolding, so the above
	 * assignment is safe
	 */
	ret = ltdb_filter_attrs(ctx, msg, ctx->attrs, &filtered_msg);

	/*
	 * Remove any extended components possibly copied in from
	 * msg->dn, we just want the casefold components
	 */
	ldb_dn_remove_extended_components(filtered_msg->dn);
	talloc_free(msg);

	if (ret == -1) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ldb_module_send_entry(ctx->req, filtered_msg, NULL);
	if (ret != LDB_SUCCESS) {
		/* Regardless of success or failure, the msg
		 * is the callbacks responsiblity, and should
		 * not be talloc_free()'ed */
		ctx->request_terminated = true;
		return ret;
	}

	return LDB_SUCCESS;
}

/*
  search the database with a LDAP-like expression.
  choses a search method
*/
int ltdb_search(struct ltdb_context *ctx)
{
	struct ldb_context *ldb;
	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 = ldb_module_get_ctx(module);

	ldb_request_set_state(req, LDB_ASYNC_PENDING);

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

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

	if (req->op.search.tree == NULL) {
		ltdb_unlock_read(module);
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ctx->tree = req->op.search.tree;
	ctx->scope = req->op.search.scope;
	ctx->base = req->op.search.base;
	ctx->attrs = req->op.search.attrs;

	if ((req->op.search.base == NULL) || (ldb_dn_is_null(req->op.search.base) == true)) {

		/* Check what we should do with a NULL dn */
		switch (req->op.search.scope) {
		case LDB_SCOPE_BASE:
			ldb_asprintf_errstring(ldb, 
					       "NULL Base DN invalid for a base search");
			ret = LDB_ERR_INVALID_DN_SYNTAX;
			break;
		case LDB_SCOPE_ONELEVEL:
			ldb_asprintf_errstring(ldb, 
					       "NULL Base DN invalid for a one-level search");
			ret = LDB_ERR_INVALID_DN_SYNTAX;	
			break;
		case LDB_SCOPE_SUBTREE:
		default:
			/* We accept subtree searches from a NULL base DN, ie over the whole DB */
			ret = LDB_SUCCESS;
		}
	} else if (ldb_dn_is_valid(req->op.search.base) == false) {

		/* We don't want invalid base DNs here */
		ldb_asprintf_errstring(ldb, 
				       "Invalid Base DN: %s", 
				       ldb_dn_get_linearized(req->op.search.base));
		ret = LDB_ERR_INVALID_DN_SYNTAX;

	} else if (req->op.search.scope == LDB_SCOPE_BASE) {

		/*
		 * If we are LDB_SCOPE_BASE, do just one search and
		 * return early.  This is critical to ensure we do not
		 * go into the index code for special DNs, as that
		 * will try to look up an index record for a special
		 * record (which doesn't exist).
		 */
		ret = ltdb_search_and_return_base(ltdb, ctx);

		ltdb_unlock_read(module);

		return ret;

	} else if (ltdb->check_base) {
		/*
		 * This database has been marked as
		 * 'checkBaseOnSearch', so do a spot check of the base
		 * dn.  Also optimise the subsequent filter by filling
		 * in the ctx->base to be exactly case correct
		 */
		ret = ltdb_search_base(module, ctx,
				       req->op.search.base,
				       &ctx->base);
		
		if (ret == LDB_ERR_NO_SUCH_OBJECT) {
			ldb_asprintf_errstring(ldb, 
					       "No such Base DN: %s", 
					       ldb_dn_get_linearized(req->op.search.base));
		}
			
	} else if (ldb_dn_validate(req->op.search.base) == false) {

		/* We don't want invalid base DNs here */
		ldb_asprintf_errstring(ldb,
				       "Invalid Base DN: %s",
				       ldb_dn_get_linearized(req->op.search.base));
		ret = LDB_ERR_INVALID_DN_SYNTAX;

	} else {
		/* If we are not checking the base DN life is easy */
		ret = LDB_SUCCESS;
	}

	if (ret == LDB_SUCCESS) {
		uint32_t match_count = 0;

		ret = ltdb_search_indexed(ctx, &match_count);
		if (ret == LDB_ERR_NO_SUCH_OBJECT) {
			/* Not in the index, therefore OK! */
			ret = LDB_SUCCESS;
			
		}
		/* Check if we got just a normal error.
		 * In that case proceed to a full search unless we got a
		 * callback error */
		if ( ! ctx->request_terminated && ret != LDB_SUCCESS) {
			/* Not indexed, so we need to do a full scan */
			if (ltdb->warn_unindexed || ltdb->disable_full_db_scan) {
				/* useful for debugging when slow performance
				 * is caused by unindexed searches */
				char *expression = ldb_filter_from_tree(ctx, ctx->tree);
				ldb_debug(ldb, LDB_DEBUG_ERROR, "ldb FULL SEARCH: %s SCOPE: %s DN: %s",
							expression,
							req->op.search.scope==LDB_SCOPE_BASE?"base":
							req->op.search.scope==LDB_SCOPE_ONELEVEL?"one":
							req->op.search.scope==LDB_SCOPE_SUBTREE?"sub":"UNKNOWN",
							ldb_dn_get_linearized(req->op.search.base));

				talloc_free(expression);
			}

			if (match_count != 0) {
				/* the indexing code gave an error
				 * after having returned at least one
				 * entry. This means the indexes are
				 * corrupt or a database record is
				 * corrupt. We cannot continue with a
				 * full search or we may return
				 * duplicate entries
				 */
				ltdb_unlock_read(module);
				return LDB_ERR_OPERATIONS_ERROR;
			}

			if (ltdb->disable_full_db_scan) {
				ldb_set_errstring(ldb,
						  "ldb FULL SEARCH disabled");
				ltdb_unlock_read(module);
				return LDB_ERR_INAPPROPRIATE_MATCHING;
			}

			ret = ltdb_search_full(ctx);
			if (ret != LDB_SUCCESS) {
				ldb_set_errstring(ldb, "Indexed and full searches both failed!\n");
			}
		}
	}

	ltdb_unlock_read(module);

	return ret;
}