summaryrefslogtreecommitdiff
path: root/source3/nsswitch/winbindd_cache.c
blob: af4ccabadeda854e005aac6cd0d21be537466381 (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
/* 
   Unix SMB/CIFS implementation.

   Winbind cache backend functions

   Copyright (C) Andrew Tridgell 2001
   Copyright (C) Gerald Carter   2003
   
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "winbindd.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_WINBIND

struct winbind_cache {
	TDB_CONTEXT *tdb;
};

struct cache_entry {
	NTSTATUS status;
	uint32 sequence_number;
	uint8 *data;
	uint32 len, ofs;
};

#define WINBINDD_MAX_CACHE_SIZE (50*1024*1024)

static struct winbind_cache *wcache;

/* flush the cache */
void wcache_flush_cache(void)
{
	extern BOOL opt_nocache;

	if (!wcache)
		return;
	if (wcache->tdb) {
		tdb_close(wcache->tdb);
		wcache->tdb = NULL;
	}
	if (opt_nocache)
		return;

	wcache->tdb = tdb_open_log(lock_path("winbindd_cache.tdb"), 5000, 
				   TDB_CLEAR_IF_FIRST, O_RDWR|O_CREAT, 0600);

	if (!wcache->tdb) {
		DEBUG(0,("Failed to open winbindd_cache.tdb!\n"));
	}
	DEBUG(10,("wcache_flush_cache success\n"));
}

void winbindd_check_cache_size(time_t t)
{
	static time_t last_check_time;
	struct stat st;

	if (last_check_time == (time_t)0)
		last_check_time = t;

	if (t - last_check_time < 60 && t - last_check_time > 0)
		return;

	if (wcache == NULL || wcache->tdb == NULL) {
		DEBUG(0, ("Unable to check size of tdb cache - cache not open !\n"));
		return;
	}

	if (fstat(wcache->tdb->fd, &st) == -1) {
		DEBUG(0, ("Unable to check size of tdb cache %s!\n", strerror(errno) ));
		return;
	}

	if (st.st_size > WINBINDD_MAX_CACHE_SIZE) {
		DEBUG(10,("flushing cache due to size (%lu) > (%lu)\n",
			(unsigned long)st.st_size,
			(unsigned long)WINBINDD_MAX_CACHE_SIZE));
		wcache_flush_cache();
	}
}

/* get the winbind_cache structure */
static struct winbind_cache *get_cache(struct winbindd_domain *domain)
{
	struct winbind_cache *ret = wcache;

	if (!domain->backend) {
		extern struct winbindd_methods msrpc_methods;
		switch (lp_security()) {
#ifdef HAVE_ADS
		case SEC_ADS: {
			extern struct winbindd_methods ads_methods;
			/* always obey the lp_security parameter for our domain */
			if ( strequal(lp_realm(), domain->alt_name) || strequal(lp_workgroup(), domain->name) ) {
				domain->backend = &ads_methods;
				break;
			}

			if ( domain->native_mode ) {
				domain->backend = &ads_methods;
				break;
			}

			/* fall through */
		}	
#endif
		default:
			domain->backend = &msrpc_methods;
		}
	}

	if (ret)
		return ret;
	
	ret = smb_xmalloc(sizeof(*ret));
	ZERO_STRUCTP(ret);

	wcache = ret;
	wcache_flush_cache();

	return ret;
}

/*
  free a centry structure
*/
static void centry_free(struct cache_entry *centry)
{
	if (!centry)
		return;
	SAFE_FREE(centry->data);
	free(centry);
}

/*
  pull a uint32 from a cache entry 
*/
static uint32 centry_uint32(struct cache_entry *centry)
{
	uint32 ret;
	if (centry->len - centry->ofs < 4) {
		DEBUG(0,("centry corruption? needed 4 bytes, have %d\n", 
			 centry->len - centry->ofs));
		smb_panic("centry_uint32");
	}
	ret = IVAL(centry->data, centry->ofs);
	centry->ofs += 4;
	return ret;
}

/*
  pull a uint8 from a cache entry 
*/
static uint8 centry_uint8(struct cache_entry *centry)
{
	uint8 ret;
	if (centry->len - centry->ofs < 1) {
		DEBUG(0,("centry corruption? needed 1 bytes, have %d\n", 
			 centry->len - centry->ofs));
		smb_panic("centry_uint32");
	}
	ret = CVAL(centry->data, centry->ofs);
	centry->ofs += 1;
	return ret;
}

/* pull a string from a cache entry, using the supplied
   talloc context 
*/
static char *centry_string(struct cache_entry *centry, TALLOC_CTX *mem_ctx)
{
	uint32 len;
	char *ret;

	len = centry_uint8(centry);

	if (len == 0xFF) {
		/* a deliberate NULL string */
		return NULL;
	}

	if (centry->len - centry->ofs < len) {
		DEBUG(0,("centry corruption? needed %d bytes, have %d\n", 
			 len, centry->len - centry->ofs));
		smb_panic("centry_string");
	}

	ret = talloc(mem_ctx, len+1);
	if (!ret) {
		smb_panic("centry_string out of memory\n");
	}
	memcpy(ret,centry->data + centry->ofs, len);
	ret[len] = 0;
	centry->ofs += len;
	return ret;
}

/* pull a string from a cache entry, using the supplied
   talloc context 
*/
static DOM_SID *centry_sid(struct cache_entry *centry, TALLOC_CTX *mem_ctx)
{
	DOM_SID *sid;
	char *sid_string;

	sid = talloc(mem_ctx, sizeof(*sid));
	if (!sid)
		return NULL;
	
	sid_string = centry_string(centry, mem_ctx);
	if (!string_to_sid(sid, sid_string)) {
		return NULL;
	}
	return sid;
}

/* the server is considered down if it can't give us a sequence number */
static BOOL wcache_server_down(struct winbindd_domain *domain)
{
	BOOL ret;

	if (!wcache->tdb)
		return False;

	ret = (domain->sequence_number == DOM_SEQUENCE_NONE);

	if (ret)
		DEBUG(10,("wcache_server_down: server for Domain %s down\n", 
			domain->name ));
	return ret;
}

static NTSTATUS fetch_cache_seqnum( struct winbindd_domain *domain, time_t now )
{
	TDB_DATA data;
	fstring key;
	uint32 time_diff;
	
	if (!wcache->tdb) {
		DEBUG(10,("fetch_cache_seqnum: tdb == NULL\n"));
		return NT_STATUS_UNSUCCESSFUL;
	}
		
	fstr_sprintf( key, "SEQNUM/%s", domain->name );
	
	data = tdb_fetch_bystring( wcache->tdb, key );
	if ( !data.dptr || data.dsize!=8 ) {
		DEBUG(10,("fetch_cache_seqnum: invalid data size key [%s]\n", key ));
		return NT_STATUS_UNSUCCESSFUL;
	}
	
	domain->sequence_number = IVAL(data.dptr, 0);
	domain->last_seq_check  = IVAL(data.dptr, 4);
	
	/* have we expired? */
	
	time_diff = now - domain->last_seq_check;
	if ( time_diff > lp_winbind_cache_time() ) {
		DEBUG(10,("fetch_cache_seqnum: timeout [%s][%u @ %u]\n",
			domain->name, domain->sequence_number,
			(uint32)domain->last_seq_check));
		return NT_STATUS_UNSUCCESSFUL;
	}

	DEBUG(10,("fetch_cache_seqnum: success [%s][%u @ %u]\n", 
		domain->name, domain->sequence_number, 
		(uint32)domain->last_seq_check));

	return NT_STATUS_OK;
}

static NTSTATUS store_cache_seqnum( struct winbindd_domain *domain )
{
	TDB_DATA data, key;
	fstring key_str;
	char buf[8];
	
	if (!wcache->tdb) {
		DEBUG(10,("store_cache_seqnum: tdb == NULL\n"));
		return NT_STATUS_UNSUCCESSFUL;
	}
		
	fstr_sprintf( key_str, "SEQNUM/%s", domain->name );
	key.dptr = key_str;
	key.dsize = strlen(key_str)+1;
	
	SIVAL(buf, 0, domain->sequence_number);
	SIVAL(buf, 4, domain->last_seq_check);
	data.dptr = buf;
	data.dsize = 8;
	
	if ( tdb_store( wcache->tdb, key, data, TDB_REPLACE) == -1 ) {
		DEBUG(10,("store_cache_seqnum: tdb_store fail key [%s]\n", key_str ));
		return NT_STATUS_UNSUCCESSFUL;
	}

	DEBUG(10,("store_cache_seqnum: success [%s][%u @ %u]\n", 
		domain->name, domain->sequence_number, 
		(uint32)domain->last_seq_check));
	
	return NT_STATUS_OK;
}

/*
  refresh the domain sequence number. If force is True
  then always refresh it, no matter how recently we fetched it
*/

static void refresh_sequence_number(struct winbindd_domain *domain, BOOL force)
{
	NTSTATUS status;
	unsigned time_diff;
	time_t t = time(NULL);
	unsigned cache_time = lp_winbind_cache_time();

	/* trying to reconnect is expensive, don't do it too often */
	if (domain->sequence_number == DOM_SEQUENCE_NONE) {
		cache_time *= 8;
	}

	time_diff = t - domain->last_seq_check;

	/* see if we have to refetch the domain sequence number */
	if (!force && (time_diff < cache_time)) {
		DEBUG(10, ("refresh_sequence_number: %s time ok\n", domain->name));
		goto done;
	}
	
	/* try to get the sequence number from the tdb cache first */
	/* this will update the timestamp as well */
	
	status = fetch_cache_seqnum( domain, t );
	if ( NT_STATUS_IS_OK(status) )
		goto done;	

	status = domain->backend->sequence_number(domain, &domain->sequence_number);

	if (!NT_STATUS_IS_OK(status)) {
		domain->sequence_number = DOM_SEQUENCE_NONE;
	}
	
	domain->last_status = status;
	domain->last_seq_check = time(NULL);
	
	/* save the new sequence number ni the cache */
	store_cache_seqnum( domain );

done:
	DEBUG(10, ("refresh_sequence_number: %s seq number is now %d\n", 
		   domain->name, domain->sequence_number));

	return;
}

/*
  decide if a cache entry has expired
*/
static BOOL centry_expired(struct winbindd_domain *domain, const char *keystr, struct cache_entry *centry)
{
	/* if the server is OK and our cache entry came from when it was down then
	   the entry is invalid */
	if (domain->sequence_number != DOM_SEQUENCE_NONE && 
	    centry->sequence_number == DOM_SEQUENCE_NONE) {
		DEBUG(10,("centry_expired: Key %s for domain %s invalid sequence.\n",
			keystr, domain->name ));
		return True;
	}

	/* if the server is down or the cache entry is not older than the
	   current sequence number then it is OK */
	if (wcache_server_down(domain) || 
	    centry->sequence_number == domain->sequence_number) {
		DEBUG(10,("centry_expired: Key %s for domain %s is good.\n",
			keystr, domain->name ));
		return False;
	}

	DEBUG(10,("centry_expired: Key %s for domain %s expired\n",
		keystr, domain->name ));

	/* it's expired */
	return True;
}

/*
  fetch an entry from the cache, with a varargs key. auto-fetch the sequence
  number and return status
*/
static struct cache_entry *wcache_fetch(struct winbind_cache *cache, 
					struct winbindd_domain *domain,
					const char *format, ...) PRINTF_ATTRIBUTE(3,4);
static struct cache_entry *wcache_fetch(struct winbind_cache *cache, 
					struct winbindd_domain *domain,
					const char *format, ...)
{
	va_list ap;
	char *kstr;
	TDB_DATA data;
	struct cache_entry *centry;
	TDB_DATA key;

	refresh_sequence_number(domain, False);

	va_start(ap, format);
	smb_xvasprintf(&kstr, format, ap);
	va_end(ap);
	
	key.dptr = kstr;
	key.dsize = strlen(kstr);
	data = tdb_fetch(wcache->tdb, key);
	if (!data.dptr) {
		/* a cache miss */
		free(kstr);
		return NULL;
	}

	centry = smb_xmalloc(sizeof(*centry));
	centry->data = data.dptr;
	centry->len = data.dsize;
	centry->ofs = 0;

	if (centry->len < 8) {
		/* huh? corrupt cache? */
		DEBUG(10,("wcache_fetch: Corrupt cache for key %s domain %s (len < 8) ?\n",
			kstr, domain->name ));
		centry_free(centry);
		free(kstr);
		return NULL;
	}
	
	centry->status = NT_STATUS(centry_uint32(centry));
	centry->sequence_number = centry_uint32(centry);

	if (centry_expired(domain, kstr, centry)) {
		extern BOOL opt_dual_daemon;

		DEBUG(10,("wcache_fetch: entry %s expired for domain %s\n",
			 kstr, domain->name ));

		if (opt_dual_daemon) {
			extern BOOL background_process;
			background_process = True;
			DEBUG(10,("wcache_fetch: background processing expired entry %s for domain %s\n",
				 kstr, domain->name ));
		} else {
			centry_free(centry);
			free(kstr);
			return NULL;
		}
	}

	DEBUG(10,("wcache_fetch: returning entry %s for domain %s\n",
		 kstr, domain->name ));

	free(kstr);
	return centry;
}

/*
  make sure we have at least len bytes available in a centry 
*/
static void centry_expand(struct cache_entry *centry, uint32 len)
{
	uint8 *p;
	if (centry->len - centry->ofs >= len)
		return;
	centry->len *= 2;
	p = realloc(centry->data, centry->len);
	if (!p) {
		DEBUG(0,("out of memory: needed %d bytes in centry_expand\n", centry->len));
		smb_panic("out of memory in centry_expand");
	}
	centry->data = p;
}

/*
  push a uint32 into a centry 
*/
static void centry_put_uint32(struct cache_entry *centry, uint32 v)
{
	centry_expand(centry, 4);
	SIVAL(centry->data, centry->ofs, v);
	centry->ofs += 4;
}

/*
  push a uint8 into a centry 
*/
static void centry_put_uint8(struct cache_entry *centry, uint8 v)
{
	centry_expand(centry, 1);
	SCVAL(centry->data, centry->ofs, v);
	centry->ofs += 1;
}

/* 
   push a string into a centry 
 */
static void centry_put_string(struct cache_entry *centry, const char *s)
{
	int len;

	if (!s) {
		/* null strings are marked as len 0xFFFF */
		centry_put_uint8(centry, 0xFF);
		return;
	}

	len = strlen(s);
	/* can't handle more than 254 char strings. Truncating is probably best */
	if (len > 254)
		len = 254;
	centry_put_uint8(centry, len);
	centry_expand(centry, len);
	memcpy(centry->data + centry->ofs, s, len);
	centry->ofs += len;
}

static void centry_put_sid(struct cache_entry *centry, const DOM_SID *sid) 
{
	fstring sid_string;
	centry_put_string(centry, sid_to_string(sid_string, sid));
}

/*
  start a centry for output. When finished, call centry_end()
*/
struct cache_entry *centry_start(struct winbindd_domain *domain, NTSTATUS status)
{
	struct cache_entry *centry;

	if (!wcache->tdb)
		return NULL;

	centry = smb_xmalloc(sizeof(*centry));

	centry->len = 8192; /* reasonable default */
	centry->data = smb_xmalloc(centry->len);
	centry->ofs = 0;
	centry->sequence_number = domain->sequence_number;
	centry_put_uint32(centry, NT_STATUS_V(status));
	centry_put_uint32(centry, centry->sequence_number);
	return centry;
}

/*
  finish a centry and write it to the tdb
*/
static void centry_end(struct cache_entry *centry, const char *format, ...) PRINTF_ATTRIBUTE(2,3);
static void centry_end(struct cache_entry *centry, const char *format, ...)
{
	va_list ap;
	char *kstr;
	TDB_DATA key, data;

	va_start(ap, format);
	smb_xvasprintf(&kstr, format, ap);
	va_end(ap);

	key.dptr = kstr;
	key.dsize = strlen(kstr);
	data.dptr = centry->data;
	data.dsize = centry->ofs;

	tdb_store(wcache->tdb, key, data, TDB_REPLACE);
	free(kstr);
}

static void wcache_save_name_to_sid(struct winbindd_domain *domain, 
				    NTSTATUS status, 
				    const char *name, DOM_SID *sid, 
				    enum SID_NAME_USE type)
{
	struct cache_entry *centry;
	fstring uname;
	fstring sid_string;

	centry = centry_start(domain, status);
	if (!centry)
		return;
	centry_put_sid(centry, sid);
	fstrcpy(uname, name);
	strupper_m(uname);
	centry_end(centry, "NS/%s", sid_to_string(sid_string, sid));
	DEBUG(10,("wcache_save_name_to_sid: %s -> %s\n", uname, sid_string));
	centry_free(centry);
}

static void wcache_save_sid_to_name(struct winbindd_domain *domain, NTSTATUS status, 
				    DOM_SID *sid, const char *name, enum SID_NAME_USE type)
{
	struct cache_entry *centry;
	fstring sid_string;

	centry = centry_start(domain, status);
	if (!centry)
		return;
	if (NT_STATUS_IS_OK(status)) {
		centry_put_uint32(centry, type);
		centry_put_string(centry, name);
	}
	centry_end(centry, "SN/%s", sid_to_string(sid_string, sid));
	DEBUG(10,("wcache_save_sid_to_name: %s -> %s\n", sid_string, name));
	centry_free(centry);
}


static void wcache_save_user(struct winbindd_domain *domain, NTSTATUS status, WINBIND_USERINFO *info)
{
	struct cache_entry *centry;
	fstring sid_string;

	centry = centry_start(domain, status);
	if (!centry)
		return;
	centry_put_string(centry, info->acct_name);
	centry_put_string(centry, info->full_name);
	centry_put_sid(centry, info->user_sid);
	centry_put_sid(centry, info->group_sid);
	centry_end(centry, "U/%s", sid_to_string(sid_string, info->user_sid));
	DEBUG(10,("wcache_save_user: %s (acct_name %s)\n", sid_string, info->acct_name));
	centry_free(centry);
}


/* Query display info. This is the basic user list fn */
static NTSTATUS query_user_list(struct winbindd_domain *domain,
				TALLOC_CTX *mem_ctx,
				uint32 *num_entries, 
				WINBIND_USERINFO **info)
{
	struct winbind_cache *cache = get_cache(domain);
	struct cache_entry *centry = NULL;
	NTSTATUS status;
	unsigned int i, retry;

	if (!cache->tdb)
		goto do_query;

	centry = wcache_fetch(cache, domain, "UL/%s", domain->name);
	if (!centry)
		goto do_query;

	*num_entries = centry_uint32(centry);
	
	if (*num_entries == 0)
		goto do_cached;

	(*info) = talloc(mem_ctx, sizeof(**info) * (*num_entries));
	if (! (*info))
		smb_panic("query_user_list out of memory");
	for (i=0; i<(*num_entries); i++) {
		(*info)[i].acct_name = centry_string(centry, mem_ctx);
		(*info)[i].full_name = centry_string(centry, mem_ctx);
		(*info)[i].user_sid = centry_sid(centry, mem_ctx);
		(*info)[i].group_sid = centry_sid(centry, mem_ctx);
	}

do_cached:	
	status = centry->status;

	DEBUG(10,("query_user_list: [Cached] - cached list for domain %s status %s\n",
		domain->name, get_friendly_nt_error_msg(status) ));

	centry_free(centry);
	return status;

do_query:
	*num_entries = 0;
	*info = NULL;

	/* Return status value returned by seq number check */

	if (!NT_STATUS_IS_OK(domain->last_status))
		return domain->last_status;

	/* Put the query_user_list() in a retry loop.  There appears to be
	 * some bug either with Windows 2000 or Samba's handling of large
	 * rpc replies.  This manifests itself as sudden disconnection
	 * at a random point in the enumeration of a large (60k) user list.
	 * The retry loop simply tries the operation again. )-:  It's not
	 * pretty but an acceptable workaround until we work out what the
	 * real problem is. */

	retry = 0;
	do {

		DEBUG(10,("query_user_list: [Cached] - doing backend query for list for domain %s\n",
			domain->name ));

		status = domain->backend->query_user_list(domain, mem_ctx, num_entries, info);
		if (!NT_STATUS_IS_OK(status))
			DEBUG(3, ("query_user_list: returned 0x%08x, retrying\n", NT_STATUS_V(status)));
			if (NT_STATUS_V(status) == NT_STATUS_V(NT_STATUS_UNSUCCESSFUL)) {
				DEBUG(3, ("query_user_list: flushing connection cache\n"));
				winbindd_cm_flush();
			}

	} while (NT_STATUS_V(status) == NT_STATUS_V(NT_STATUS_UNSUCCESSFUL) && 
		 (retry++ < 5));

	/* and save it */
	refresh_sequence_number(domain, False);
	centry = centry_start(domain, status);
	if (!centry)
		goto skip_save;
	centry_put_uint32(centry, *num_entries);
	for (i=0; i<(*num_entries); i++) {
		centry_put_string(centry, (*info)[i].acct_name);
		centry_put_string(centry, (*info)[i].full_name);
		centry_put_sid(centry, (*info)[i].user_sid);
		centry_put_sid(centry, (*info)[i].group_sid);
		if (domain->backend->consistent) {
			/* when the backend is consistent we can pre-prime some mappings */
			wcache_save_name_to_sid(domain, NT_STATUS_OK, 
						(*info)[i].acct_name, 
						(*info)[i].user_sid,
						SID_NAME_USER);
			wcache_save_sid_to_name(domain, NT_STATUS_OK, 
						(*info)[i].user_sid,
						(*info)[i].acct_name, 
						SID_NAME_USER);
			wcache_save_user(domain, NT_STATUS_OK, &(*info)[i]);
		}
	}	
	centry_end(centry, "UL/%s", domain->name);
	centry_free(centry);

skip_save:
	return status;
}

/* list all domain groups */
static NTSTATUS enum_dom_groups(struct winbindd_domain *domain,
				TALLOC_CTX *mem_ctx,
				uint32 *num_entries, 
				struct acct_info **info)
{
	struct winbind_cache *cache = get_cache(domain);
	struct cache_entry *centry = NULL;
	NTSTATUS status;
	unsigned int i;

	if (!cache->tdb)
		goto do_query;

	centry = wcache_fetch(cache, domain, "GL/%s/domain", domain->name);
	if (!centry)
		goto do_query;

	*num_entries = centry_uint32(centry);
	
	if (*num_entries == 0)
		goto do_cached;

	(*info) = talloc(mem_ctx, sizeof(**info) * (*num_entries));
	if (! (*info))
		smb_panic("enum_dom_groups out of memory");
	for (i=0; i<(*num_entries); i++) {
		fstrcpy((*info)[i].acct_name, centry_string(centry, mem_ctx));
		fstrcpy((*info)[i].acct_desc, centry_string(centry, mem_ctx));
		(*info)[i].rid = centry_uint32(centry);
	}

do_cached:	
	status = centry->status;

	DEBUG(10,("enum_dom_groups: [Cached] - cached list for domain %s status %s\n",
		domain->name, get_friendly_nt_error_msg(status) ));

	centry_free(centry);
	return status;

do_query:
	*num_entries = 0;
	*info = NULL;

	/* Return status value returned by seq number check */

	if (!NT_STATUS_IS_OK(domain->last_status))
		return domain->last_status;

	DEBUG(10,("enum_dom_groups: [Cached] - doing backend query for list for domain %s\n",
		domain->name ));

	status = domain->backend->enum_dom_groups(domain, mem_ctx, num_entries, info);

	/* and save it */
	refresh_sequence_number(domain, False);
	centry = centry_start(domain, status);
	if (!centry)
		goto skip_save;
	centry_put_uint32(centry, *num_entries);
	for (i=0; i<(*num_entries); i++) {
		centry_put_string(centry, (*info)[i].acct_name);
		centry_put_string(centry, (*info)[i].acct_desc);
		centry_put_uint32(centry, (*info)[i].rid);
	}	
	centry_end(centry, "GL/%s/domain", domain->name);
	centry_free(centry);

skip_save:
	return status;
}

/* list all domain groups */
static NTSTATUS enum_local_groups(struct winbindd_domain *domain,
				TALLOC_CTX *mem_ctx,
				uint32 *num_entries, 
				struct acct_info **info)
{
	struct winbind_cache *cache = get_cache(domain);
	struct cache_entry *centry = NULL;
	NTSTATUS status;
	unsigned int i;

	if (!cache->tdb)
		goto do_query;

	centry = wcache_fetch(cache, domain, "GL/%s/local", domain->name);
	if (!centry)
		goto do_query;

	*num_entries = centry_uint32(centry);
	
	if (*num_entries == 0)
		goto do_cached;

	(*info) = talloc(mem_ctx, sizeof(**info) * (*num_entries));
	if (! (*info))
		smb_panic("enum_dom_groups out of memory");
	for (i=0; i<(*num_entries); i++) {
		fstrcpy((*info)[i].acct_name, centry_string(centry, mem_ctx));
		fstrcpy((*info)[i].acct_desc, centry_string(centry, mem_ctx));
		(*info)[i].rid = centry_uint32(centry);
	}

do_cached:	

	/* If we are returning cached data and the domain controller
	   is down then we don't know whether the data is up to date
	   or not.  Return NT_STATUS_MORE_PROCESSING_REQUIRED to
	   indicate this. */

	if (wcache_server_down(domain)) {
		DEBUG(10, ("enum_local_groups: returning cached user list and server was down\n"));
		status = NT_STATUS_MORE_PROCESSING_REQUIRED;
	} else
		status = centry->status;

	DEBUG(10,("enum_local_groups: [Cached] - cached list for domain %s status %s\n",
		domain->name, get_friendly_nt_error_msg(status) ));

	centry_free(centry);
	return status;

do_query:
	*num_entries = 0;
	*info = NULL;

	/* Return status value returned by seq number check */

	if (!NT_STATUS_IS_OK(domain->last_status))
		return domain->last_status;

	DEBUG(10,("enum_local_groups: [Cached] - doing backend query for list for domain %s\n",
		domain->name ));

	status = domain->backend->enum_local_groups(domain, mem_ctx, num_entries, info);

	/* and save it */
	refresh_sequence_number(domain, False);
	centry = centry_start(domain, status);
	if (!centry)
		goto skip_save;
	centry_put_uint32(centry, *num_entries);
	for (i=0; i<(*num_entries); i++) {
		centry_put_string(centry, (*info)[i].acct_name);
		centry_put_string(centry, (*info)[i].acct_desc);
		centry_put_uint32(centry, (*info)[i].rid);
	}
	centry_end(centry, "GL/%s/local", domain->name);
	centry_free(centry);

skip_save:
	return status;
}

/* convert a single name to a sid in a domain */
static NTSTATUS name_to_sid(struct winbindd_domain *domain,
			    TALLOC_CTX *mem_ctx,
			    const char *name,
			    DOM_SID *sid,
			    enum SID_NAME_USE *type)
{
	struct winbind_cache *cache = get_cache(domain);
	struct cache_entry *centry = NULL;
	NTSTATUS status;
	fstring uname;
	DOM_SID *sid2;

	if (!cache->tdb)
		goto do_query;

	fstrcpy(uname, name);
	strupper_m(uname);
	centry = wcache_fetch(cache, domain, "NS/%s/%s", domain->name, uname);
	if (!centry)
		goto do_query;
	*type = centry_uint32(centry);
	sid2 = centry_sid(centry, mem_ctx);
	if (!sid2) {
		ZERO_STRUCTP(sid);
	} else {
		sid_copy(sid, sid2);
	}

	status = centry->status;

	DEBUG(10,("name_to_sid: [Cached] - cached name for domain %s status %s\n",
		domain->name, get_friendly_nt_error_msg(status) ));

	centry_free(centry);
	return status;

do_query:
	ZERO_STRUCTP(sid);

	/* If the seq number check indicated that there is a problem
	 * with this DC, then return that status... except for
	 * access_denied.  This is special because the dc may be in
	 * "restrict anonymous = 1" mode, in which case it will deny
	 * most unauthenticated operations, but *will* allow the LSA
	 * name-to-sid that we try as a fallback. */

	if (!(NT_STATUS_IS_OK(domain->last_status)
	      || NT_STATUS_EQUAL(domain->last_status, NT_STATUS_ACCESS_DENIED)))
		return domain->last_status;

	DEBUG(10,("name_to_sid: [Cached] - doing backend query for name for domain %s\n",
		domain->name ));

	status = domain->backend->name_to_sid(domain, mem_ctx, name, sid, type);

	/* and save it */
	wcache_save_name_to_sid(domain, status, name, sid, *type);

	/* We can't save the sid to name mapping as we don't know the
	   correct case of the name without looking it up */

	return status;
}

/* convert a sid to a user or group name. The sid is guaranteed to be in the domain
   given */
static NTSTATUS sid_to_name(struct winbindd_domain *domain,
			    TALLOC_CTX *mem_ctx,
			    DOM_SID *sid,
			    char **name,
			    enum SID_NAME_USE *type)
{
	struct winbind_cache *cache = get_cache(domain);
	struct cache_entry *centry = NULL;
	NTSTATUS status;
	fstring sid_string;

	if (!cache->tdb)
		goto do_query;

	centry = wcache_fetch(cache, domain, "SN/%s", sid_to_string(sid_string, sid));
	if (!centry)
		goto do_query;
	if (NT_STATUS_IS_OK(centry->status)) {
		*type = centry_uint32(centry);
		*name = centry_string(centry, mem_ctx);
	}
	status = centry->status;

	DEBUG(10,("sid_to_name: [Cached] - cached name for domain %s status %s\n",
		domain->name, get_friendly_nt_error_msg(status) ));

	centry_free(centry);
	return status;

do_query:
	*name = NULL;

	/* If the seq number check indicated that there is a problem
	 * with this DC, then return that status... except for
	 * access_denied.  This is special because the dc may be in
	 * "restrict anonymous = 1" mode, in which case it will deny
	 * most unauthenticated operations, but *will* allow the LSA
	 * sid-to-name that we try as a fallback. */

	if (!(NT_STATUS_IS_OK(domain->last_status)
	      || NT_STATUS_EQUAL(domain->last_status, NT_STATUS_ACCESS_DENIED)))
		return domain->last_status;

	DEBUG(10,("sid_to_name: [Cached] - doing backend query for name for domain %s\n",
		domain->name ));

	status = domain->backend->sid_to_name(domain, mem_ctx, sid, name, type);

	/* and save it */
	refresh_sequence_number(domain, False);
	wcache_save_sid_to_name(domain, status, sid, *name, *type);
	wcache_save_name_to_sid(domain, status, *name, sid, *type);

	return status;
}


/* Lookup user information from a rid */
static NTSTATUS query_user(struct winbindd_domain *domain, 
			   TALLOC_CTX *mem_ctx, 
			   DOM_SID *user_sid, 
			   WINBIND_USERINFO *info)
{
	struct winbind_cache *cache = get_cache(domain);
	struct cache_entry *centry = NULL;
	NTSTATUS status;

	if (!cache->tdb)
		goto do_query;

	centry = wcache_fetch(cache, domain, "U/%s", sid_string_static(user_sid));
	
	/* If we have an access denied cache entry and a cached info3 in the
           samlogon cache then do a query.  This will force the rpc back end
           to return the info3 data. */

	if (NT_STATUS_V(domain->last_status) == NT_STATUS_V(NT_STATUS_ACCESS_DENIED) &&
	    netsamlogon_cache_have(user_sid)) {
		DEBUG(10, ("query_user: cached access denied and have cached info3\n"));
		domain->last_status = NT_STATUS_OK;
		centry_free(centry);
		goto do_query;
	}
	
	if (!centry)
		goto do_query;

	info->acct_name = centry_string(centry, mem_ctx);
	info->full_name = centry_string(centry, mem_ctx);
	info->user_sid = centry_sid(centry, mem_ctx);
	info->group_sid = centry_sid(centry, mem_ctx);
	status = centry->status;

	DEBUG(10,("query_user: [Cached] - cached info for domain %s status %s\n",
		domain->name, get_friendly_nt_error_msg(status) ));

	centry_free(centry);
	return status;

do_query:
	ZERO_STRUCTP(info);

	/* Return status value returned by seq number check */

	if (!NT_STATUS_IS_OK(domain->last_status))
		return domain->last_status;
	
	DEBUG(10,("sid_to_name: [Cached] - doing backend query for info for domain %s\n",
		domain->name ));

	status = domain->backend->query_user(domain, mem_ctx, user_sid, info);

	/* and save it */
	refresh_sequence_number(domain, False);
	wcache_save_user(domain, status, info);

	return status;
}


/* Lookup groups a user is a member of. */
static NTSTATUS lookup_usergroups(struct winbindd_domain *domain,
				  TALLOC_CTX *mem_ctx,
				  DOM_SID *user_sid, 
				  uint32 *num_groups, DOM_SID ***user_gids)
{
	struct winbind_cache *cache = get_cache(domain);
	struct cache_entry *centry = NULL;
	NTSTATUS status;
	unsigned int i;
	fstring sid_string;

	if (!cache->tdb)
		goto do_query;

	centry = wcache_fetch(cache, domain, "UG/%s", sid_to_string(sid_string, user_sid));
	
	/* If we have an access denied cache entry and a cached info3 in the
           samlogon cache then do a query.  This will force the rpc back end
           to return the info3 data. */

	if (NT_STATUS_V(domain->last_status) == NT_STATUS_V(NT_STATUS_ACCESS_DENIED) &&
	    netsamlogon_cache_have(user_sid)) {
		DEBUG(10, ("query_user: cached access denied and have cached info3\n"));
		domain->last_status = NT_STATUS_OK;
		centry_free(centry);
		goto do_query;
	}
	
	if (!centry)
		goto do_query;

	*num_groups = centry_uint32(centry);
	
	if (*num_groups == 0)
		goto do_cached;

	(*user_gids) = talloc(mem_ctx, sizeof(**user_gids) * (*num_groups));
	if (! (*user_gids))
		smb_panic("lookup_usergroups out of memory");
	for (i=0; i<(*num_groups); i++) {
		(*user_gids)[i] = centry_sid(centry, mem_ctx);
	}

do_cached:	
	status = centry->status;

	DEBUG(10,("lookup_usergroups: [Cached] - cached info for domain %s status %s\n",
		domain->name, get_friendly_nt_error_msg(status) ));

	centry_free(centry);
	return status;

do_query:
	(*num_groups) = 0;
	(*user_gids) = NULL;

	/* Return status value returned by seq number check */

	if (!NT_STATUS_IS_OK(domain->last_status))
		return domain->last_status;

	DEBUG(10,("lookup_usergroups: [Cached] - doing backend query for info for domain %s\n",
		domain->name ));

	status = domain->backend->lookup_usergroups(domain, mem_ctx, user_sid, num_groups, user_gids);

	/* and save it */
	refresh_sequence_number(domain, False);
	centry = centry_start(domain, status);
	if (!centry)
		goto skip_save;
	centry_put_uint32(centry, *num_groups);
	for (i=0; i<(*num_groups); i++) {
		centry_put_sid(centry, (*user_gids)[i]);
	}	
	centry_end(centry, "UG/%s", sid_to_string(sid_string, user_sid));
	centry_free(centry);

skip_save:
	return status;
}


static NTSTATUS lookup_groupmem(struct winbindd_domain *domain,
				TALLOC_CTX *mem_ctx,
				DOM_SID *group_sid, uint32 *num_names, 
				DOM_SID ***sid_mem, char ***names, 
				uint32 **name_types)
{
	struct winbind_cache *cache = get_cache(domain);
	struct cache_entry *centry = NULL;
	NTSTATUS status;
	unsigned int i;
	fstring sid_string;

	if (!cache->tdb)
		goto do_query;

	centry = wcache_fetch(cache, domain, "GM/%s", sid_to_string(sid_string, group_sid));
	if (!centry)
		goto do_query;

	*num_names = centry_uint32(centry);
	
	if (*num_names == 0)
		goto do_cached;

	(*sid_mem) = talloc(mem_ctx, sizeof(**sid_mem) * (*num_names));
	(*names) = talloc(mem_ctx, sizeof(**names) * (*num_names));
	(*name_types) = talloc(mem_ctx, sizeof(**name_types) * (*num_names));

	if (! (*sid_mem) || ! (*names) || ! (*name_types)) {
		smb_panic("lookup_groupmem out of memory");
	}

	for (i=0; i<(*num_names); i++) {
		(*sid_mem)[i] = centry_sid(centry, mem_ctx);
		(*names)[i] = centry_string(centry, mem_ctx);
		(*name_types)[i] = centry_uint32(centry);
	}

do_cached:	
	status = centry->status;

	DEBUG(10,("lookup_groupmem: [Cached] - cached info for domain %s status %s\n",
		domain->name, get_friendly_nt_error_msg(status) ));

	centry_free(centry);
	return status;

do_query:
	(*num_names) = 0;
	(*sid_mem) = NULL;
	(*names) = NULL;
	(*name_types) = NULL;
	
	/* Return status value returned by seq number check */

	if (!NT_STATUS_IS_OK(domain->last_status))
		return domain->last_status;

	DEBUG(10,("lookup_groupmem: [Cached] - doing backend query for info for domain %s\n",
		domain->name ));

	status = domain->backend->lookup_groupmem(domain, mem_ctx, group_sid, num_names, 
						  sid_mem, names, name_types);

	/* and save it */
	refresh_sequence_number(domain, False);
	centry = centry_start(domain, status);
	if (!centry)
		goto skip_save;
	centry_put_uint32(centry, *num_names);
	for (i=0; i<(*num_names); i++) {
		centry_put_sid(centry, (*sid_mem)[i]);
		centry_put_string(centry, (*names)[i]);
		centry_put_uint32(centry, (*name_types)[i]);
	}	
	centry_end(centry, "GM/%s", sid_to_string(sid_string, group_sid));
	centry_free(centry);

skip_save:
	return status;
}

/* find the sequence number for a domain */
static NTSTATUS sequence_number(struct winbindd_domain *domain, uint32 *seq)
{
	refresh_sequence_number(domain, False);

	*seq = domain->sequence_number;

	return NT_STATUS_OK;
}

/* enumerate trusted domains */
static NTSTATUS trusted_domains(struct winbindd_domain *domain,
				TALLOC_CTX *mem_ctx,
				uint32 *num_domains,
				char ***names,
				char ***alt_names,
				DOM_SID **dom_sids)
{
	get_cache(domain);

	DEBUG(10,("trusted_domains: [Cached] - doing backend query for info for domain %s\n",
		domain->name ));

	/* we don't cache this call */
	return domain->backend->trusted_domains(domain, mem_ctx, num_domains, 
					       names, alt_names, dom_sids);
}

/* find the domain sid */
static NTSTATUS domain_sid(struct winbindd_domain *domain, DOM_SID *sid)
{
	get_cache(domain);

	DEBUG(10,("domain_sid: [Cached] - doing backend query for info for domain %s\n",
		domain->name ));

	/* we don't cache this call */
	return domain->backend->domain_sid(domain, sid);
}

/* find the alternate names for the domain, if any */
static NTSTATUS alternate_name(struct winbindd_domain *domain)
{
	get_cache(domain);

	DEBUG(10,("alternate_name: [Cached] - doing backend query for info for domain %s\n",
		domain->name ));

	/* we don't cache this call */
	return domain->backend->alternate_name(domain);
}

/* Invalidate cached user and group lists coherently */

static int traverse_fn(TDB_CONTEXT *the_tdb, TDB_DATA kbuf, TDB_DATA dbuf, 
		       void *state)
{
	if (strncmp(kbuf.dptr, "UL/", 3) == 0 ||
	    strncmp(kbuf.dptr, "GL/", 3) == 0)
		tdb_delete(the_tdb, kbuf);

	return 0;
}

/* Invalidate the getpwnam and getgroups entries for a winbindd domain */

void wcache_invalidate_samlogon(struct winbindd_domain *domain, 
				NET_USER_INFO_3 *info3)
{
	struct winbind_cache *cache;
	
	if (!domain)
		return;

	cache = get_cache(domain);
	netsamlogon_clear_cached_user(cache->tdb, info3);
}

void wcache_invalidate_cache(void)
{
	struct winbindd_domain *domain;

	for (domain = domain_list(); domain; domain = domain->next) {
		struct winbind_cache *cache = get_cache(domain);

		DEBUG(10, ("wcache_invalidate_cache: invalidating cache "
			   "entries for %s\n", domain->name));
		if (cache)
			tdb_traverse(cache->tdb, traverse_fn, NULL);
	}
}

/* the ADS backend methods are exposed via this structure */
struct winbindd_methods cache_methods = {
	True,
	query_user_list,
	enum_dom_groups,
	enum_local_groups,
	name_to_sid,
	sid_to_name,
	query_user,
	lookup_usergroups,
	lookup_groupmem,
	sequence_number,
	trusted_domains,
	domain_sid,
	alternate_name
};