summaryrefslogtreecommitdiff
path: root/source4/lib/ldb/common/ldb_msg.c
blob: f1dd6f3544a2c08d49f0f6987a688aff6b4a945b (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
/* 
   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 message component utility functions
 *
 *  Description: functions for manipulating ldb_message structures
 *
 *  Author: Andrew Tridgell
 */

#include "ldb_private.h"

/*
  create a new ldb_message in a given memory context (NULL for top level)
*/
struct ldb_message *ldb_msg_new(void *mem_ctx)
{
	return talloc_zero(mem_ctx, struct ldb_message);
}

/*
  find an element in a message by attribute name
*/
struct ldb_message_element *ldb_msg_find_element(const struct ldb_message *msg, 
						 const char *attr_name)
{
	unsigned int i;
	for (i=0;i<msg->num_elements;i++) {
		if (ldb_attr_cmp(msg->elements[i].name, attr_name) == 0) {
			return &msg->elements[i];
		}
	}
	return NULL;
}

/*
  see if two ldb_val structures contain exactly the same data
  return 1 for a match, 0 for a mis-match
*/
int ldb_val_equal_exact(const struct ldb_val *v1, const struct ldb_val *v2)
{
	if (v1->length != v2->length) return 0;
	if (v1->data == v2->data) return 1;
	if (v1->length == 0) return 1;

	if (memcmp(v1->data, v2->data, v1->length) == 0) {
		return 1;
	}

	return 0;
}

/*
  find a value in an element
  assumes case sensitive comparison
*/
struct ldb_val *ldb_msg_find_val(const struct ldb_message_element *el, 
				 struct ldb_val *val)
{
	unsigned int i;
	for (i=0;i<el->num_values;i++) {
		if (ldb_val_equal_exact(val, &el->values[i])) {
			return &el->values[i];
		}
	}
	return NULL;
}

/*
  duplicate a ldb_val structure
*/
struct ldb_val ldb_val_dup(void *mem_ctx, const struct ldb_val *v)
{
	struct ldb_val v2;
	v2.length = v->length;
	if (v->data == NULL) {
		v2.data = NULL;
		return v2;
	}

	/* the +1 is to cope with buggy C library routines like strndup
	   that look one byte beyond */
	v2.data = talloc_array(mem_ctx, uint8_t, v->length+1);
	if (!v2.data) {
		v2.length = 0;
		return v2;
	}

	memcpy(v2.data, v->data, v->length);
	((char *)v2.data)[v->length] = 0;
	return v2;
}

/*
  add an empty element to a message
*/
int ldb_msg_add_empty(	struct ldb_message *msg,
			const char *attr_name,
			int flags,
			struct ldb_message_element **return_el)
{
	struct ldb_message_element *els;

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

	els[msg->num_elements].values = NULL;
	els[msg->num_elements].num_values = 0;
	els[msg->num_elements].flags = flags;
	els[msg->num_elements].name = talloc_strdup(els, attr_name);
	if (!els[msg->num_elements].name) {
		errno = ENOMEM;
		return LDB_ERR_OPERATIONS_ERROR;
	}

	msg->elements = els;
	msg->num_elements++;

	if (return_el) {
		*return_el = &els[msg->num_elements-1];
	}

	return LDB_SUCCESS;
}

/*
  add an empty element to a message
*/
int ldb_msg_add(struct ldb_message *msg, 
		const struct ldb_message_element *el, 
		int flags)
{
	/* We have to copy this, just in case *el is a pointer into
	 * what ldb_msg_add_empty() is about to realloc() */
	struct ldb_message_element el_copy = *el;
	if (ldb_msg_add_empty(msg, el->name, flags, NULL) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	msg->elements[msg->num_elements-1] = el_copy;
	msg->elements[msg->num_elements-1].flags = flags;

	return LDB_SUCCESS;
}

/*
  add a value to a message
*/
int ldb_msg_add_value(struct ldb_message *msg, 
		      const char *attr_name,
		      const struct ldb_val *val,
		      struct ldb_message_element **return_el)
{
	struct ldb_message_element *el;
	struct ldb_val *vals;
	int ret;

	el = ldb_msg_find_element(msg, attr_name);
	if (!el) {
		ret = ldb_msg_add_empty(msg, attr_name, 0, &el);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	vals = talloc_realloc(msg, el->values, struct ldb_val, el->num_values+1);
	if (!vals) {
		errno = ENOMEM;
		return LDB_ERR_OPERATIONS_ERROR;
	}
	el->values = vals;
	el->values[el->num_values] = *val;
	el->num_values++;

	if (return_el) {
		*return_el = el;
	}

	return LDB_SUCCESS;
}


/*
  add a value to a message, stealing it into the 'right' place
*/
int ldb_msg_add_steal_value(struct ldb_message *msg, 
			    const char *attr_name,
			    struct ldb_val *val)
{
	int ret;
	struct ldb_message_element *el;

	ret = ldb_msg_add_value(msg, attr_name, val, &el);
	if (ret == LDB_SUCCESS) {
		talloc_steal(el->values, val->data);
	}
	return ret;
}


/*
  add a string element to a message
*/
int ldb_msg_add_string(struct ldb_message *msg, 
		       const char *attr_name, const char *str)
{
	struct ldb_val val;

	val.data = discard_const_p(uint8_t, str);
	val.length = strlen(str);

	if (val.length == 0) {
		/* allow empty strings as non-existant attributes */
		return LDB_SUCCESS;
	}

	return ldb_msg_add_value(msg, attr_name, &val, NULL);
}

/*
  add a string element to a message, stealing it into the 'right' place
*/
int ldb_msg_add_steal_string(struct ldb_message *msg, 
			     const char *attr_name, char *str)
{
	struct ldb_val val;

	val.data = (uint8_t *)str;
	val.length = strlen(str);

	return ldb_msg_add_steal_value(msg, attr_name, &val);
}

/*
  add a DN element to a message
  WARNING: this uses the linearized string from the dn, and does not
  copy the string.
*/
int ldb_msg_add_dn(struct ldb_message *msg, const char *attr_name,
		   struct ldb_dn *dn)
{
	return ldb_msg_add_string(msg, attr_name, ldb_dn_get_linearized(dn));
}

/*
  add a printf formatted element to a message
*/
int ldb_msg_add_fmt(struct ldb_message *msg, 
		    const char *attr_name, const char *fmt, ...)
{
	struct ldb_val val;
	va_list ap;
	char *str;

	va_start(ap, fmt);
	str = talloc_vasprintf(msg, fmt, ap);
	va_end(ap);

	if (str == NULL) return LDB_ERR_OPERATIONS_ERROR;

	val.data   = (uint8_t *)str;
	val.length = strlen(str);

	return ldb_msg_add_steal_value(msg, attr_name, &val);
}

/*
  compare two ldb_message_element structures
  assumes case senistive comparison
*/
int ldb_msg_element_compare(struct ldb_message_element *el1, 
			    struct ldb_message_element *el2)
{
	unsigned int i;

	if (el1->num_values != el2->num_values) {
		return el1->num_values - el2->num_values;
	}

	for (i=0;i<el1->num_values;i++) {
		if (!ldb_msg_find_val(el2, &el1->values[i])) {
			return -1;
		}
	}

	return 0;
}

/*
  compare two ldb_message_element structures
  comparing by element name
*/
int ldb_msg_element_compare_name(struct ldb_message_element *el1, 
				 struct ldb_message_element *el2)
{
	return ldb_attr_cmp(el1->name, el2->name);
}

/*
  convenience functions to return common types from a message
  these return the first value if the attribute is multi-valued
*/
const struct ldb_val *ldb_msg_find_ldb_val(const struct ldb_message *msg, 
					   const char *attr_name)
{
	struct ldb_message_element *el = ldb_msg_find_element(msg, attr_name);
	if (!el || el->num_values == 0) {
		return NULL;
	}
	return &el->values[0];
}

int ldb_msg_find_attr_as_int(const struct ldb_message *msg, 
			     const char *attr_name,
			     int default_value)
{
	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
	if (!v || !v->data) {
		return default_value;
	}
	return strtol((const char *)v->data, NULL, 0);
}

unsigned int ldb_msg_find_attr_as_uint(const struct ldb_message *msg, 
				       const char *attr_name,
				       unsigned int default_value)
{
	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
	if (!v || !v->data) {
		return default_value;
	}
	return strtoul((const char *)v->data, NULL, 0);
}

int64_t ldb_msg_find_attr_as_int64(const struct ldb_message *msg, 
				   const char *attr_name,
				   int64_t default_value)
{
	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
	if (!v || !v->data) {
		return default_value;
	}
	return strtoll((const char *)v->data, NULL, 0);
}

uint64_t ldb_msg_find_attr_as_uint64(const struct ldb_message *msg, 
				     const char *attr_name,
				     uint64_t default_value)
{
	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
	if (!v || !v->data) {
		return default_value;
	}
	return strtoull((const char *)v->data, NULL, 0);
}

double ldb_msg_find_attr_as_double(const struct ldb_message *msg, 
				   const char *attr_name,
				   double default_value)
{
	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
	if (!v || !v->data) {
		return default_value;
	}
	return strtod((const char *)v->data, NULL);
}

int ldb_msg_find_attr_as_bool(const struct ldb_message *msg, 
			      const char *attr_name,
			      int default_value)
{
	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
	if (!v || !v->data) {
		return default_value;
	}
	if (v->length == 5 && strncasecmp((const char *)v->data, "FALSE", 5) == 0) {
		return 0;
	}
	if (v->length == 4 && strncasecmp((const char *)v->data, "TRUE", 4) == 0) {
		return 1;
	}
	return default_value;
}

const char *ldb_msg_find_attr_as_string(const struct ldb_message *msg, 
					const char *attr_name,
					const char *default_value)
{
	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
	if (!v || !v->data) {
		return default_value;
	}
	return (const char *)v->data;
}

struct ldb_dn *ldb_msg_find_attr_as_dn(struct ldb_context *ldb,
				       void *mem_ctx,
				       const struct ldb_message *msg,
				       const char *attr_name)
{
	struct ldb_dn *res_dn;
	const struct ldb_val *v;

	v = ldb_msg_find_ldb_val(msg, attr_name);
	if (!v || !v->data) {
		return NULL;
	}
	res_dn = ldb_dn_from_ldb_val(mem_ctx, ldb, v);
	if ( ! ldb_dn_validate(res_dn)) {
		talloc_free(res_dn);
		return NULL;
	}
	return res_dn;
}

/*
  sort the elements of a message by name
*/
void ldb_msg_sort_elements(struct ldb_message *msg)
{
	qsort(msg->elements, msg->num_elements, sizeof(struct ldb_message_element), 
	      (comparison_fn_t)ldb_msg_element_compare_name);
}

/*
  shallow copy a message - copying only the elements array so that the caller
  can safely add new elements without changing the message
*/
struct ldb_message *ldb_msg_copy_shallow(TALLOC_CTX *mem_ctx, 
					 const struct ldb_message *msg)
{
	struct ldb_message *msg2;
	int i;

	msg2 = talloc(mem_ctx, struct ldb_message);
	if (msg2 == NULL) return NULL;

	*msg2 = *msg;

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

	for (i=0;i<msg2->num_elements;i++) {
		msg2->elements[i] = msg->elements[i];
	}

	return msg2;

failed:
	talloc_free(msg2);
	return NULL;
}


/*
  copy a message, allocating new memory for all parts
*/
struct ldb_message *ldb_msg_copy(TALLOC_CTX *mem_ctx, 
				 const struct ldb_message *msg)
{
	struct ldb_message *msg2;
	int i, j;

	msg2 = ldb_msg_copy_shallow(mem_ctx, msg);
	if (msg2 == NULL) return NULL;

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

	for (i=0;i<msg2->num_elements;i++) {
		struct ldb_message_element *el = &msg2->elements[i];
		struct ldb_val *values = el->values;
		el->name = talloc_strdup(msg2->elements, el->name);
		if (el->name == NULL) goto failed;
		el->values = talloc_array(msg2->elements, struct ldb_val, el->num_values);
		for (j=0;j<el->num_values;j++) {
			el->values[j] = ldb_val_dup(el->values, &values[j]);
			if (el->values[j].data == NULL && values[j].length != 0) {
				goto failed;
			}
		}
	}

	return msg2;

failed:
	talloc_free(msg2);
	return NULL;
}


/*
  canonicalise a message, merging elements of the same name
*/
struct ldb_message *ldb_msg_canonicalize(struct ldb_context *ldb, 
					 const struct ldb_message *msg)
{
	int i;
	struct ldb_message *msg2;

	msg2 = ldb_msg_copy(ldb, msg);
	if (msg2 == NULL) return NULL;

	ldb_msg_sort_elements(msg2);

	for (i=1;i<msg2->num_elements;i++) {
		struct ldb_message_element *el1 = &msg2->elements[i-1];
		struct ldb_message_element *el2 = &msg2->elements[i];
		if (ldb_msg_element_compare_name(el1, el2) == 0) {
			el1->values = talloc_realloc(msg2->elements, el1->values, struct ldb_val, 
						       el1->num_values + el2->num_values);
			if (el1->num_values + el2->num_values > 0 && el1->values == NULL) {
				return NULL;
			}
			memcpy(el1->values + el1->num_values,
			       el2->values,
			       sizeof(struct ldb_val) * el2->num_values);
			el1->num_values += el2->num_values;
			talloc_free(discard_const_p(char, el2->name));
			if (i+1<msg2->num_elements) {
				memmove(el2, el2+1, sizeof(struct ldb_message_element) * 
					(msg2->num_elements - (i+1)));
			}
			msg2->num_elements--;
			i--;
		}
	}

	return msg2;
}


/*
  return a ldb_message representing the differences between msg1 and msg2. If you
  then use this in a ldb_modify() call it can be used to save edits to a message
*/
struct ldb_message *ldb_msg_diff(struct ldb_context *ldb, 
				 struct ldb_message *msg1,
				 struct ldb_message *msg2)
{
	struct ldb_message *mod;
	struct ldb_message_element *el;
	unsigned int i;

	mod = ldb_msg_new(ldb);
	if (mod == NULL) {
		return NULL;
	}

	mod->dn = msg1->dn;
	mod->num_elements = 0;
	mod->elements = NULL;

	msg2 = ldb_msg_canonicalize(ldb, msg2);
	if (msg2 == NULL) {
		talloc_free(mod);
		return NULL;
	}
	
	/* look in msg2 to find elements that need to be added
	   or modified */
	for (i=0;i<msg2->num_elements;i++) {
		el = ldb_msg_find_element(msg1, msg2->elements[i].name);

		if (el && ldb_msg_element_compare(el, &msg2->elements[i]) == 0) {
			continue;
		}

		if (ldb_msg_add(mod, 
				&msg2->elements[i],
				el?LDB_FLAG_MOD_REPLACE:LDB_FLAG_MOD_ADD) != LDB_SUCCESS) {
			talloc_free(mod);
			return NULL;
		}
	}

	/* look in msg1 to find elements that need to be deleted */
	for (i=0;i<msg1->num_elements;i++) {
		el = ldb_msg_find_element(msg2, msg1->elements[i].name);
		if (el == NULL) {
			if (ldb_msg_add_empty(mod, 
					      msg1->elements[i].name,
					      LDB_FLAG_MOD_DELETE, NULL) != LDB_SUCCESS) {
				talloc_free(mod);
				return NULL;
			}
		}
	}

	return mod;
}

int ldb_msg_sanity_check(struct ldb_context *ldb, 
			 const struct ldb_message *msg)
{
	int i, j;

	/* basic check on DN */
	if (msg->dn == NULL) {
		/* TODO: return also an error string */
		ldb_set_errstring(ldb, "ldb message lacks a DN!");
		return LDB_ERR_INVALID_DN_SYNTAX;
	}

	/* basic syntax checks */
	for (i = 0; i < msg->num_elements; i++) {
		for (j = 0; j < msg->elements[i].num_values; j++) {
			if (msg->elements[i].values[j].length == 0) {
				TALLOC_CTX *mem_ctx = talloc_new(ldb);
				/* an attribute cannot be empty */
				/* TODO: return also an error string */
				ldb_asprintf_errstring(ldb, "Element %s has empty attribute in ldb message (%s)!",
							    msg->elements[i].name, 
							    ldb_dn_get_linearized(msg->dn));
				talloc_free(mem_ctx);
				return LDB_ERR_INVALID_ATTRIBUTE_SYNTAX;
			}
		}
	}

	return LDB_SUCCESS;
}




/*
  copy an attribute list. This only copies the array, not the elements
  (ie. the elements are left as the same pointers)
*/
const char **ldb_attr_list_copy(TALLOC_CTX *mem_ctx, const char * const *attrs)
{
	const char **ret;
	int i;
	for (i=0;attrs && attrs[i];i++) /* noop */ ;
	ret = talloc_array(mem_ctx, const char *, i+1);
	if (ret == NULL) {
		return NULL;
	}
	for (i=0;attrs && attrs[i];i++) {
		ret[i] = attrs[i];
	}
	ret[i] = attrs[i];
	return ret;
}


/*
  copy an attribute list. This only copies the array, not the elements
  (ie. the elements are left as the same pointers).  The new attribute is added to the list.
*/
const char **ldb_attr_list_copy_add(TALLOC_CTX *mem_ctx, const char * const *attrs, const char *new_attr)
{
	const char **ret;
	int i;
	bool found = false;
	for (i=0;attrs && attrs[i];i++) {
		if (ldb_attr_cmp(attrs[i], new_attr) == 0) {
			found = true;
		}
	}
	if (found) {
		return ldb_attr_list_copy(mem_ctx, attrs);
	}
	ret = talloc_array(mem_ctx, const char *, i+2);
	if (ret == NULL) {
		return NULL;
	}
	for (i=0;attrs && attrs[i];i++) {
		ret[i] = attrs[i];
	}
	ret[i] = new_attr;
	ret[i+1] = NULL;
	return ret;
}


/*
  return 1 if an attribute is in a list of attributes, or 0 otherwise
*/
int ldb_attr_in_list(const char * const *attrs, const char *attr)
{
	int i;
	for (i=0;attrs && attrs[i];i++) {
		if (ldb_attr_cmp(attrs[i], attr) == 0) {
			return 1;
		}
	}
	return 0;
}


/*
  rename the specified attribute in a search result
*/
int ldb_msg_rename_attr(struct ldb_message *msg, const char *attr, const char *replace)
{
	struct ldb_message_element *el = ldb_msg_find_element(msg, attr);
	if (el == NULL) {
		return LDB_SUCCESS;
	}
	el->name = talloc_strdup(msg->elements, replace);
	if (el->name == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	return LDB_SUCCESS;
}


/*
  copy the specified attribute in a search result to a new attribute
*/
int ldb_msg_copy_attr(struct ldb_message *msg, const char *attr, const char *replace)
{
	struct ldb_message_element *el = ldb_msg_find_element(msg, attr);
	if (el == NULL) {
		return LDB_SUCCESS;
	}
	if (ldb_msg_add(msg, el, 0) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	return ldb_msg_rename_attr(msg, attr, replace);
}

/*
  remove the specified element in a search result
*/
void ldb_msg_remove_element(struct ldb_message *msg, struct ldb_message_element *el)
{
	int n = (el - msg->elements);
	if (n >= msg->num_elements) {
		/* should we abort() here? */
		return;
	}
	if (n != msg->num_elements-1) {
		memmove(el, el+1, ((msg->num_elements-1) - n)*sizeof(*el));
	}
	msg->num_elements--;
}


/*
  remove the specified attribute in a search result
*/
void ldb_msg_remove_attr(struct ldb_message *msg, const char *attr)
{
	struct ldb_message_element *el = ldb_msg_find_element(msg, attr);
	if (el) {
		ldb_msg_remove_element(msg, el);
	}
}

/*
  return a LDAP formatted GeneralizedTime string
*/
char *ldb_timestring(TALLOC_CTX *mem_ctx, time_t t)
{
	struct tm *tm = gmtime(&t);
	char *ts;
	int r;

	if (!tm) {
		return NULL;
	}

	/* we now excatly how long this string will be */
	ts = talloc_array(mem_ctx, char, 18);

	/* formatted like: 20040408072012.0Z */
	r = snprintf(ts, 18,
			"%04u%02u%02u%02u%02u%02u.0Z",
			tm->tm_year+1900, tm->tm_mon+1,
			tm->tm_mday, tm->tm_hour, tm->tm_min,
			tm->tm_sec);

	if (r != 17) {
		talloc_free(ts);
		return NULL;
	}

	return ts;
}

/*
  convert a LDAP GeneralizedTime string to a time_t. Return 0 if unable to convert
*/
time_t ldb_string_to_time(const char *s)
{
	struct tm tm;
	
	if (s == NULL) return 0;
	
	memset(&tm, 0, sizeof(tm));
	if (sscanf(s, "%04u%02u%02u%02u%02u%02u", 
		   &tm.tm_year, &tm.tm_mon, &tm.tm_mday, 
		   &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
		return 0;
	}
	tm.tm_year -= 1900;
	tm.tm_mon -= 1;
	
	return timegm(&tm);
}

/*
  return a LDAP formatted UTCTime string
*/
char *ldb_timestring_utc(TALLOC_CTX *mem_ctx, time_t t)
{
	struct tm *tm = gmtime(&t);
	char *ts;
	int r;

	if (!tm) {
		return NULL;
	}

	/* we now excatly how long this string will be */
	ts = talloc_array(mem_ctx, char, 14);

	/* formatted like: 20040408072012.0Z => 040408072012Z */
	r = snprintf(ts, 14,
			"%02u%02u%02u%02u%02u%02uZ",
			(tm->tm_year+1900)%100, tm->tm_mon+1,
			tm->tm_mday, tm->tm_hour, tm->tm_min,
			tm->tm_sec);

	if (r != 13) {
		talloc_free(ts);
		return NULL;
	}

	return ts;
}

/*
  convert a LDAP UTCTime string to a time_t. Return 0 if unable to convert
*/
time_t ldb_string_utc_to_time(const char *s)
{
	struct tm tm;
	
	if (s == NULL) return 0;
	
	memset(&tm, 0, sizeof(tm));
	if (sscanf(s, "%02u%02u%02u%02u%02u%02u", 
		   &tm.tm_year, &tm.tm_mon, &tm.tm_mday, 
		   &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
		return 0;
	}
	if (tm.tm_year < 50) {
		tm.tm_year += 100;
	}
	tm.tm_mon -= 1;
	
	return timegm(&tm);
}


/*
  dump a set of results to a file. Useful from within gdb
*/
void ldb_dump_results(struct ldb_context *ldb, struct ldb_result *result, FILE *f)
{
	int i;

	for (i = 0; i < result->count; i++) {
		struct ldb_ldif ldif;
		fprintf(f, "# record %d\n", i+1);
		ldif.changetype = LDB_CHANGETYPE_NONE;
		ldif.msg = result->msgs[i];
		ldb_ldif_write_file(ldb, f, &ldif);
	}
}

/*
  checks for a string attribute. Returns "1" on match and otherwise "0".
*/
int ldb_msg_check_string_attribute(const struct ldb_message *msg,
				   const char *name, const char *value)
{
	struct ldb_message_element *el;
	struct ldb_val val;
	
	el = ldb_msg_find_element(msg, name);
	if (el == NULL) {
		return 0;
	}

	val.data = discard_const_p(uint8_t, value);
	val.length = strlen(value);

	if (ldb_msg_find_val(el, &val)) {
		return 1;
	}

	return 0;
}