summaryrefslogtreecommitdiff
path: root/lib/dbwrap/dbwrap.c
blob: 15eb239c358994f0a71c5ee32d356954a0f31b51 (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
/*
   Unix SMB/CIFS implementation.
   Database interface wrapper
   Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2006

   Major code contributions from Aleksey Fedoseev (fedoseev@ru.ibm.com)

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

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

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

#include "includes.h"
#include "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_private.h"
#include "lib/util/util_tdb.h"

/*
 * Fall back using fetch if no genuine exists operation is provided
 */

static int dbwrap_fallback_exists(struct db_context *db, TDB_DATA key)
{
	NTSTATUS status = dbwrap_parse_record(db, key, NULL, NULL);
	return NT_STATUS_IS_OK(status) ? 1 : 0;
}

static int delete_record(struct db_record *rec, void *data)
{
	NTSTATUS status = dbwrap_record_delete(rec);
	return NT_STATUS_IS_OK(status) ? 0 : -1;
}

/*
 * Fallback wipe implementation using traverse and delete if no genuine
 * wipe operation is provided
 */
static int dbwrap_fallback_wipe(struct db_context *db)
{
	NTSTATUS status = dbwrap_trans_traverse(db, delete_record, NULL);
	return NT_STATUS_IS_OK(status) ? 0 : -1;
}

static int do_nothing(struct db_record *rec, void *unused)
{
	return 0;
}

/*
 * Fallback check operation: just traverse.
 */
static int dbwrap_fallback_check(struct db_context *db)
{
	NTSTATUS status = dbwrap_traverse_read(db, do_nothing, NULL, NULL);
	return NT_STATUS_IS_OK(status) ? 0 : -1;
}

/*
 * Wrapper functions for the backend methods
 */

TDB_DATA dbwrap_record_get_key(const struct db_record *rec)
{
	return rec->key;
}

TDB_DATA dbwrap_record_get_value(const struct db_record *rec)
{
	return rec->value;
}

NTSTATUS dbwrap_record_store(struct db_record *rec, TDB_DATA data, int flags)
{
	NTSTATUS status;
	struct db_context *db;

	status = rec->store(rec, data, flags);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}
	db = rec->db;
	if (db->stored_callback != NULL) {
		db->stored_callback(db, rec,
				    db->stored_callback_private_data);
	}
	return NT_STATUS_OK;
}

void dbwrap_set_stored_callback(
	struct db_context *db,
	void (*cb)(struct db_context *db, struct db_record *rec,
		   void *private_data),
	void *private_data)
{
	db->stored_callback = cb;
	db->stored_callback_private_data = private_data;
}

NTSTATUS dbwrap_record_delete(struct db_record *rec)
{
	NTSTATUS status;
	struct db_context *db;

	status = rec->delete_rec(rec);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}
	db = rec->db;
	if (db->stored_callback != NULL) {
		db->stored_callback(db, rec,
				    db->stored_callback_private_data);
	}
	return NT_STATUS_OK;
}

struct dbwrap_lock_order_state {
	struct db_context **locked_dbs;
	struct db_context *db;
};

static void debug_lock_order(int level, struct db_context *dbs[])
{
	int i;
	DEBUG(level, ("lock order: "));
	for (i=0; i<DBWRAP_LOCK_ORDER_MAX; i++) {
		DEBUGADD(level, (" %d:%s", i + 1, dbs[i] ? dbs[i]->name : "<none>"));
	}
	DEBUGADD(level, ("\n"));
}

static int dbwrap_lock_order_state_destructor(
	struct dbwrap_lock_order_state *s)
{
	int idx = s->db->lock_order - 1;

	DEBUG(5, ("release lock order %d for %s\n",
		  (int)s->db->lock_order, s->db->name));

	if (s->locked_dbs[idx] != s->db) {
		DEBUG(0, ("locked db at lock order %d is %s, expected %s\n",
			  idx + 1, s->locked_dbs[idx]->name, s->db->name));
		debug_lock_order(0, s->locked_dbs);
		smb_panic("inconsistent lock_order\n");
	}

	s->locked_dbs[idx] = NULL;

	debug_lock_order(10, s->locked_dbs);

	return 0;
}


static struct dbwrap_lock_order_state *dbwrap_check_lock_order(
	struct db_context *db, TALLOC_CTX *mem_ctx)
{
	int idx;
	static struct db_context *locked_dbs[DBWRAP_LOCK_ORDER_MAX];
	struct dbwrap_lock_order_state *state = NULL;

	if (db->lock_order == 0) {
		/*
		 * lock order 0 is for example for dbwrap_rbt without
		 * real locking. Return state nevertheless to avoid
		 * special cases.
		 */
		return talloc_zero(mem_ctx, struct dbwrap_lock_order_state);
	}

	if (db->lock_order > DBWRAP_LOCK_ORDER_MAX) {
		DEBUG(0,("Invalid lock order %d of %s\n",
			 (int)db->lock_order, db->name));
		smb_panic("invalid lock_order\n");
		return NULL;
	}

	DEBUG(5, ("check lock order %d for %s\n",
		  (int)db->lock_order, db->name));


	for (idx=db->lock_order - 1; idx < DBWRAP_LOCK_ORDER_MAX; idx++) {
		if (locked_dbs[idx] != NULL) {
			DEBUG(0, ("Lock order violation: Trying %s at %d while %s at %d is locked\n",
				  db->name, (int)db->lock_order, locked_dbs[idx]->name, idx + 1));
			debug_lock_order(0, locked_dbs);
			smb_panic("invalid lock_order");
			return NULL;
		}
	}

	state = talloc(mem_ctx, struct dbwrap_lock_order_state);
	if (state == NULL) {
		DEBUG(1, ("talloc failed\n"));
		return NULL;
	}
	state->db = db;
	state->locked_dbs = locked_dbs;
	talloc_set_destructor(state, dbwrap_lock_order_state_destructor);

	locked_dbs[db->lock_order - 1] = db;

	debug_lock_order(10, locked_dbs);

	return state;
}

static struct db_record *dbwrap_fetch_locked_internal(
	struct db_context *db, TALLOC_CTX *mem_ctx, TDB_DATA key,
	struct db_record *(*db_fn)(struct db_context *db, TALLOC_CTX *mem_ctx,
				   TDB_DATA key))
{
	struct db_record *rec;
	struct dbwrap_lock_order_state *lock_order;
	TALLOC_CTX *frame = talloc_stackframe();

	lock_order = dbwrap_check_lock_order(db, frame);
	if (lock_order == NULL) {
		TALLOC_FREE(frame);
		return NULL;
	}
	rec = db_fn(db, mem_ctx, key);
	if (rec == NULL) {
		TALLOC_FREE(frame);
		return NULL;
	}
	(void)talloc_steal(rec, lock_order);
	rec->db = db;
	TALLOC_FREE(frame);
	return rec;
}

struct db_record *dbwrap_fetch_locked(struct db_context *db,
				      TALLOC_CTX *mem_ctx,
				      TDB_DATA key)
{
	return dbwrap_fetch_locked_internal(db, mem_ctx, key,
					    db->fetch_locked);
}

struct db_record *dbwrap_try_fetch_locked(struct db_context *db,
				      TALLOC_CTX *mem_ctx,
				      TDB_DATA key)
{
	return dbwrap_fetch_locked_internal(
		db, mem_ctx, key,
		db->try_fetch_locked
		? db->try_fetch_locked : db->fetch_locked);
}

struct db_record *dbwrap_fetch_locked_timeout(struct db_context *db,
					      TALLOC_CTX *mem_ctx,
					      TDB_DATA key,
					      unsigned int timeout)
{
	struct db_record *rec;
	struct dbwrap_lock_order_state *lock_order;
	TALLOC_CTX *frame = talloc_stackframe();

	lock_order = dbwrap_check_lock_order(db, frame);
	if (lock_order == NULL) {
		TALLOC_FREE(frame);
		return NULL;
	}
	rec = db->fetch_locked_timeout
		? db->fetch_locked_timeout(db, mem_ctx, key, timeout)
		: db->fetch_locked(db, mem_ctx, key);
	if (rec == NULL) {
		TALLOC_FREE(frame);
		return NULL;
	}
	(void)talloc_steal(rec, lock_order);
	rec->db = db;
	TALLOC_FREE(frame);
	return rec;
}

struct db_context *dbwrap_record_get_db(struct db_record *rec)
{
	return rec->db;
}

struct dbwrap_fetch_state {
	TALLOC_CTX *mem_ctx;
	TDB_DATA data;
};

static void dbwrap_fetch_parser(TDB_DATA key, TDB_DATA data,
				void *private_data)
{
	struct dbwrap_fetch_state *state =
		(struct dbwrap_fetch_state *)private_data;

	state->data.dsize = data.dsize;
	state->data.dptr = (uint8_t *)talloc_memdup(state->mem_ctx, data.dptr,
						    data.dsize);
}

NTSTATUS dbwrap_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
		      TDB_DATA key, TDB_DATA *value)
{
	struct dbwrap_fetch_state state;
	NTSTATUS status;

	if (value == NULL) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	state.mem_ctx = mem_ctx;

	status = dbwrap_parse_record(db, key, dbwrap_fetch_parser, &state);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}
	if ((state.data.dsize != 0) && (state.data.dptr == NULL)) {
		return NT_STATUS_NO_MEMORY;
	}
	*value = state.data;
	return NT_STATUS_OK;
}

bool dbwrap_exists(struct db_context *db, TDB_DATA key)
{
	int result;
	if (db->exists != NULL) {
		result = db->exists(db, key);
	} else {
		result = dbwrap_fallback_exists(db,key);
	}
	return (result == 1);
}

NTSTATUS dbwrap_store(struct db_context *db, TDB_DATA key,
		      TDB_DATA data, int flags)
{
	struct db_record *rec;
	NTSTATUS status;
	TALLOC_CTX *frame = talloc_stackframe();

	rec = dbwrap_fetch_locked(db, frame, key);
	if (rec == NULL) {
		TALLOC_FREE(frame);
		return NT_STATUS_NO_MEMORY;
	}

	status = dbwrap_record_store(rec, data, flags);
	TALLOC_FREE(frame);
	return status;
}

NTSTATUS dbwrap_delete(struct db_context *db, TDB_DATA key)
{
	struct db_record *rec;
	NTSTATUS status;
	TALLOC_CTX *frame = talloc_stackframe();

	rec = dbwrap_fetch_locked(db, frame, key);
	if (rec == NULL) {
		TALLOC_FREE(frame);
		return NT_STATUS_NO_MEMORY;
	}
	status = dbwrap_record_delete(rec);
	TALLOC_FREE(frame);
	return status;
}

NTSTATUS dbwrap_traverse(struct db_context *db,
			 int (*f)(struct db_record*, void*),
			 void *private_data,
			 int *count)
{
	int ret = db->traverse(db, f, private_data);

	if (ret < 0) {
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}

	if (count != NULL) {
		*count = ret;
	}

	return NT_STATUS_OK;
}

NTSTATUS dbwrap_traverse_read(struct db_context *db,
			      int (*f)(struct db_record*, void*),
			      void *private_data,
			      int *count)
{
	int ret = db->traverse_read(db, f, private_data);

	if (ret < 0) {
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}

	if (count != NULL) {
		*count = ret;
	}

	return NT_STATUS_OK;
}

static void dbwrap_null_parser(TDB_DATA key, TDB_DATA val, void* data)
{
	return;
}

NTSTATUS dbwrap_parse_record(struct db_context *db, TDB_DATA key,
			     void (*parser)(TDB_DATA key, TDB_DATA data,
					    void *private_data),
			     void *private_data)
{
	if (parser == NULL) {
		parser = dbwrap_null_parser;
	}
	return db->parse_record(db, key, parser, private_data);
}

int dbwrap_wipe(struct db_context *db)
{
	if (db->wipe == NULL) {
		return dbwrap_fallback_wipe(db);
	}
	return db->wipe(db);
}

int dbwrap_hash_size(struct db_context *db)
{
	return db->hash_size;
}

int dbwrap_check(struct db_context *db)
{
	if (db->check == NULL) {
		return dbwrap_fallback_check(db);
	}
	return db->check(db);
}

int dbwrap_get_seqnum(struct db_context *db)
{
	return db->get_seqnum(db);
}

int dbwrap_transaction_start(struct db_context *db)
{
	return db->transaction_start(db);
}

NTSTATUS dbwrap_transaction_start_nonblock(struct db_context *db)
{
	if (db->transaction_start_nonblock) {
		return db->transaction_start_nonblock(db);
	} else {
		return dbwrap_transaction_start(db) == 0 ? NT_STATUS_OK
			: NT_STATUS_UNSUCCESSFUL;
	}
}

int dbwrap_transaction_commit(struct db_context *db)
{
	return db->transaction_commit(db);
}

int dbwrap_transaction_cancel(struct db_context *db)
{
	return db->transaction_cancel(db);
}

void dbwrap_db_id(struct db_context *db, const uint8_t **id, size_t *idlen)
{
	db->id(db, id, idlen);
}

bool dbwrap_is_persistent(struct db_context *db)
{
	return db->persistent;
}

const char *dbwrap_name(struct db_context *db)
{
	return db->name;
}