1 /*
2 Unix SMB/CIFS implementation.
3
4 trivial database library
5
6 Copyright (C) Andrew Tridgell 1999-2005
7 Copyright (C) Paul `Rusty' Russell 2000
8 Copyright (C) Jeremy Allison 2000-2003
9
10 ** NOTE! The following LGPL license applies to the tdb
11 ** library. This does NOT imply that all of Samba is released
12 ** under the LGPL
13
14 This library is free software; you can redistribute it and/or
15 modify it under the terms of the GNU Lesser General Public
16 License as published by the Free Software Foundation; either
17 version 3 of the License, or (at your option) any later version.
18
19 This library is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
22 Lesser General Public License for more details.
23
24 You should have received a copy of the GNU Lesser General Public
25 License along with this library; if not, see <http://www.gnu.org/licenses/>.
26 */
27
28 #include "tdb_private.h"
29
30 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
31 static struct tdb_context *tdbs = NULL;
32
33 /* We use two hashes to double-check they're using the right hash function. */
tdb_header_hash(struct tdb_context * tdb,uint32_t * magic1_hash,uint32_t * magic2_hash)34 void tdb_header_hash(struct tdb_context *tdb,
35 uint32_t *magic1_hash, uint32_t *magic2_hash)
36 {
37 TDB_DATA hash_key;
38 uint32_t tdb_magic = TDB_MAGIC;
39
40 hash_key.dptr = discard_const_p(unsigned char, TDB_MAGIC_FOOD);
41 hash_key.dsize = sizeof(TDB_MAGIC_FOOD);
42 *magic1_hash = tdb->hash_fn(&hash_key);
43
44 hash_key.dptr = (unsigned char *)CONVERT(tdb_magic);
45 hash_key.dsize = sizeof(tdb_magic);
46 *magic2_hash = tdb->hash_fn(&hash_key);
47
48 /* Make sure at least one hash is non-zero! */
49 if (*magic1_hash == 0 && *magic2_hash == 0)
50 *magic1_hash = 1;
51 }
52
53 /* initialise a new database with a specified hash size */
tdb_new_database(struct tdb_context * tdb,struct tdb_header * header,int hash_size)54 static int tdb_new_database(struct tdb_context *tdb, struct tdb_header *header,
55 int hash_size)
56 {
57 struct tdb_header *newdb;
58 size_t size;
59 int ret = -1;
60
61 /* We make it up in memory, then write it out if not internal */
62 size = sizeof(struct tdb_header) + (hash_size+1)*sizeof(tdb_off_t);
63 if (!(newdb = (struct tdb_header *)calloc(size, 1))) {
64 tdb->ecode = TDB_ERR_OOM;
65 return -1;
66 }
67
68 /* Fill in the header */
69 newdb->version = TDB_VERSION;
70 newdb->hash_size = hash_size;
71
72 tdb_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
73
74 /* Make sure older tdbs (which don't check the magic hash fields)
75 * will refuse to open this TDB. */
76 if (tdb->flags & TDB_INCOMPATIBLE_HASH)
77 newdb->rwlocks = TDB_HASH_RWLOCK_MAGIC;
78
79 /*
80 * We create a tdb with TDB_FEATURE_FLAG_MUTEX support,
81 * the flag combination and runtime feature checks
82 * are done by the caller already.
83 */
84 if (tdb->flags & TDB_MUTEX_LOCKING) {
85 newdb->feature_flags |= TDB_FEATURE_FLAG_MUTEX;
86 }
87
88 /*
89 * If we have any features we add the FEATURE_FLAG_MAGIC, overwriting the
90 * TDB_HASH_RWLOCK_MAGIC above.
91 */
92 if (newdb->feature_flags != 0) {
93 newdb->rwlocks = TDB_FEATURE_FLAG_MAGIC;
94 }
95
96 /*
97 * It's required for some following code pathes
98 * to have the fields on 'tdb' up-to-date.
99 *
100 * E.g. tdb_mutex_size() requires it
101 */
102 tdb->feature_flags = newdb->feature_flags;
103 tdb->hash_size = newdb->hash_size;
104
105 if (tdb->flags & TDB_INTERNAL) {
106 tdb->map_size = size;
107 tdb->map_ptr = (char *)newdb;
108 memcpy(header, newdb, sizeof(*header));
109 /* Convert the `ondisk' version if asked. */
110 CONVERT(*newdb);
111 return 0;
112 }
113 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
114 goto fail;
115
116 if (ftruncate(tdb->fd, 0) == -1)
117 goto fail;
118
119 if (newdb->feature_flags & TDB_FEATURE_FLAG_MUTEX) {
120 newdb->mutex_size = tdb_mutex_size(tdb);
121 tdb->hdr_ofs = newdb->mutex_size;
122 }
123
124 /* This creates an endian-converted header, as if read from disk */
125 CONVERT(*newdb);
126 memcpy(header, newdb, sizeof(*header));
127 /* Don't endian-convert the magic food! */
128 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
129
130 if (!tdb_write_all(tdb->fd, newdb, size))
131 goto fail;
132
133 if (newdb->feature_flags & TDB_FEATURE_FLAG_MUTEX) {
134
135 /*
136 * Now we init the mutex area
137 * followed by a second header.
138 */
139
140 ret = ftruncate(
141 tdb->fd,
142 newdb->mutex_size + sizeof(struct tdb_header));
143 if (ret == -1) {
144 goto fail;
145 }
146 ret = tdb_mutex_init(tdb);
147 if (ret == -1) {
148 goto fail;
149 }
150
151 /*
152 * Write a second header behind the mutexes. That's the area
153 * that will be mmapp'ed.
154 */
155 ret = lseek(tdb->fd, newdb->mutex_size, SEEK_SET);
156 if (ret == -1) {
157 goto fail;
158 }
159 if (!tdb_write_all(tdb->fd, newdb, size)) {
160 goto fail;
161 }
162 }
163
164 ret = 0;
165 fail:
166 SAFE_FREE(newdb);
167 return ret;
168 }
169
170
171
tdb_already_open(dev_t device,ino_t ino)172 static int tdb_already_open(dev_t device,
173 ino_t ino)
174 {
175 struct tdb_context *i;
176
177 for (i = tdbs; i; i = i->next) {
178 if (i->device == device && i->inode == ino) {
179 return 1;
180 }
181 }
182
183 return 0;
184 }
185
186 /* open the database, creating it if necessary
187
188 The open_flags and mode are passed straight to the open call on the
189 database file. A flags value of O_WRONLY is invalid. The hash size
190 is advisory, use zero for a default value.
191
192 Return is NULL on error, in which case errno is also set. Don't
193 try to call tdb_error or tdb_errname, just do strerror(errno).
194
195 @param name may be NULL for internal databases. */
tdb_open(const char * name,int hash_size,int tdb_flags,int open_flags,mode_t mode)196 _PUBLIC_ struct tdb_context *tdb_open(const char *name, int hash_size, int tdb_flags,
197 int open_flags, mode_t mode)
198 {
199 return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL);
200 }
201
202 /* a default logging function */
203 static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...) PRINTF_ATTRIBUTE(3, 4);
null_log_fn(struct tdb_context * tdb,enum tdb_debug_level level,const char * fmt,...)204 static void null_log_fn(struct tdb_context *tdb, enum tdb_debug_level level, const char *fmt, ...)
205 {
206 }
207
check_header_hash(struct tdb_context * tdb,struct tdb_header * header,bool default_hash,uint32_t * m1,uint32_t * m2)208 static bool check_header_hash(struct tdb_context *tdb,
209 struct tdb_header *header,
210 bool default_hash, uint32_t *m1, uint32_t *m2)
211 {
212 tdb_header_hash(tdb, m1, m2);
213 if (header->magic1_hash == *m1 &&
214 header->magic2_hash == *m2) {
215 return true;
216 }
217
218 /* If they explicitly set a hash, always respect it. */
219 if (!default_hash)
220 return false;
221
222 /* Otherwise, try the other inbuilt hash. */
223 if (tdb->hash_fn == tdb_old_hash)
224 tdb->hash_fn = tdb_jenkins_hash;
225 else
226 tdb->hash_fn = tdb_old_hash;
227 return check_header_hash(tdb, header, false, m1, m2);
228 }
229
tdb_mutex_open_ok(struct tdb_context * tdb,const struct tdb_header * header)230 static bool tdb_mutex_open_ok(struct tdb_context *tdb,
231 const struct tdb_header *header)
232 {
233 if (tdb->flags & TDB_NOLOCK) {
234 /*
235 * We don't look at locks, so it does not matter to have a
236 * compatible mutex implementation. Allow the open.
237 */
238 return true;
239 }
240
241 if (!(tdb->flags & TDB_MUTEX_LOCKING)) {
242 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_mutex_open_ok[%s]: "
243 "Can use mutexes only with "
244 "MUTEX_LOCKING or NOLOCK\n",
245 tdb->name));
246 return false;
247 }
248
249 if (tdb_mutex_size(tdb) != header->mutex_size) {
250 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_mutex_open_ok[%s]: "
251 "Mutex size changed from %"PRIu32" to %zu\n.",
252 tdb->name,
253 header->mutex_size,
254 tdb_mutex_size(tdb)));
255 return false;
256 }
257
258 return true;
259 }
260
tdb_open_ex(const char * name,int hash_size,int tdb_flags,int open_flags,mode_t mode,const struct tdb_logging_context * log_ctx,tdb_hash_func hash_fn)261 _PUBLIC_ struct tdb_context *tdb_open_ex(const char *name, int hash_size, int tdb_flags,
262 int open_flags, mode_t mode,
263 const struct tdb_logging_context *log_ctx,
264 tdb_hash_func hash_fn)
265 {
266 int orig_errno = errno;
267 struct tdb_header header = {
268 .version = 0,
269 };
270 struct tdb_context *tdb;
271 struct stat st;
272 int rev = 0;
273 bool locked = false;
274 unsigned char *vp;
275 uint32_t vertest;
276 unsigned v;
277 const char *hash_alg;
278 uint32_t magic1, magic2;
279 int ret;
280
281 if (!(tdb = (struct tdb_context *)calloc(1, sizeof *tdb))) {
282 /* Can't log this */
283 errno = ENOMEM;
284 goto fail;
285 }
286 tdb_io_init(tdb);
287
288 if (tdb_flags & TDB_INTERNAL) {
289 tdb_flags |= TDB_INCOMPATIBLE_HASH;
290 }
291 if (tdb_flags & TDB_MUTEX_LOCKING) {
292 tdb_flags |= TDB_INCOMPATIBLE_HASH;
293 }
294
295 tdb->fd = -1;
296 #ifdef TDB_TRACE
297 tdb->tracefd = -1;
298 #endif
299 tdb->name = NULL;
300 tdb->map_ptr = NULL;
301 tdb->flags = tdb_flags;
302 tdb->open_flags = open_flags;
303 if (log_ctx) {
304 tdb->log = *log_ctx;
305 } else {
306 tdb->log.log_fn = null_log_fn;
307 tdb->log.log_private = NULL;
308 }
309
310 if (name == NULL && (tdb_flags & TDB_INTERNAL)) {
311 name = "__TDB_INTERNAL__";
312 }
313
314 if (name == NULL) {
315 tdb->name = discard_const_p(char, "__NULL__");
316 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: called with name == NULL\n"));
317 tdb->name = NULL;
318 errno = EINVAL;
319 goto fail;
320 }
321
322 /* now make a copy of the name, as the caller memory might go away */
323 if (!(tdb->name = (char *)strdup(name))) {
324 /*
325 * set the name as the given string, so that tdb_name() will
326 * work in case of an error.
327 */
328 tdb->name = discard_const_p(char, name);
329 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't strdup(%s)\n",
330 name));
331 tdb->name = NULL;
332 errno = ENOMEM;
333 goto fail;
334 }
335
336 if (hash_fn) {
337 tdb->hash_fn = hash_fn;
338 hash_alg = "the user defined";
339 } else {
340 /* This controls what we use when creating a tdb. */
341 if (tdb->flags & TDB_INCOMPATIBLE_HASH) {
342 tdb->hash_fn = tdb_jenkins_hash;
343 } else {
344 tdb->hash_fn = tdb_old_hash;
345 }
346 hash_alg = "either default";
347 }
348
349 /* cache the page size */
350 tdb->page_size = getpagesize();
351 if (tdb->page_size <= 0) {
352 tdb->page_size = 0x2000;
353 }
354
355 tdb->max_dead_records = (tdb_flags & TDB_VOLATILE) ? 5 : 0;
356
357 if ((open_flags & O_ACCMODE) == O_WRONLY) {
358 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: can't open tdb %s write-only\n",
359 name));
360 errno = EINVAL;
361 goto fail;
362 }
363
364 if (hash_size == 0)
365 hash_size = DEFAULT_HASH_SIZE;
366 if ((open_flags & O_ACCMODE) == O_RDONLY) {
367 tdb->read_only = 1;
368 /* read only databases don't do locking or clear if first */
369 tdb->flags |= TDB_NOLOCK;
370 tdb->flags &= ~(TDB_CLEAR_IF_FIRST|TDB_MUTEX_LOCKING);
371 }
372
373 if ((tdb->flags & TDB_ALLOW_NESTING) &&
374 (tdb->flags & TDB_DISALLOW_NESTING)) {
375 tdb->ecode = TDB_ERR_NESTING;
376 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
377 "allow_nesting and disallow_nesting are not allowed together!"));
378 errno = EINVAL;
379 goto fail;
380 }
381
382 if (tdb->flags & TDB_MUTEX_LOCKING) {
383 /*
384 * Here we catch bugs in the callers,
385 * the runtime check for existing tdb's comes later.
386 */
387
388 if (tdb->flags & TDB_INTERNAL) {
389 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
390 "invalid flags for %s - TDB_MUTEX_LOCKING and "
391 "TDB_INTERNAL are not allowed together\n", name));
392 errno = EINVAL;
393 goto fail;
394 }
395
396 if (tdb->flags & TDB_NOMMAP) {
397 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
398 "invalid flags for %s - TDB_MUTEX_LOCKING and "
399 "TDB_NOMMAP are not allowed together\n", name));
400 errno = EINVAL;
401 goto fail;
402 }
403
404 if (tdb->read_only) {
405 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
406 "invalid flags for %s - TDB_MUTEX_LOCKING "
407 "not allowed read only\n", name));
408 errno = EINVAL;
409 goto fail;
410 }
411
412 /*
413 * The callers should have called
414 * tdb_runtime_check_for_robust_mutexes()
415 * before using TDB_MUTEX_LOCKING!
416 *
417 * This makes sure the caller understands
418 * that the locking may behave a bit differently
419 * than with pure fcntl locking. E.g. multiple
420 * read locks are not supported.
421 */
422 if (!tdb_runtime_check_for_robust_mutexes()) {
423 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
424 "invalid flags for %s - TDB_MUTEX_LOCKING "
425 "requires support for robust_mutexes\n",
426 name));
427 errno = ENOSYS;
428 goto fail;
429 }
430 }
431
432 if (getenv("TDB_NO_FSYNC")) {
433 tdb->flags |= TDB_NOSYNC;
434 }
435
436 /*
437 * TDB_ALLOW_NESTING is the default behavior.
438 * Note: this may change in future versions!
439 */
440 if (!(tdb->flags & TDB_DISALLOW_NESTING)) {
441 tdb->flags |= TDB_ALLOW_NESTING;
442 }
443
444 /* internal databases don't mmap or lock, and start off cleared */
445 if (tdb->flags & TDB_INTERNAL) {
446 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
447 tdb->flags &= ~TDB_CLEAR_IF_FIRST;
448 if (tdb_new_database(tdb, &header, hash_size) != 0) {
449 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: tdb_new_database failed!"));
450 goto fail;
451 }
452 tdb->hash_size = hash_size;
453 goto internal;
454 }
455
456 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
457 TDB_LOG((tdb, TDB_DEBUG_WARNING, "tdb_open_ex: could not open file %s: %s\n",
458 name, strerror(errno)));
459 goto fail; /* errno set by open(2) */
460 }
461
462 /* on exec, don't inherit the fd */
463 v = fcntl(tdb->fd, F_GETFD, 0);
464 fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
465
466 /* ensure there is only one process initialising at once */
467 if (tdb_nest_lock(tdb, OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
468 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to get open lock on %s: %s\n",
469 name, strerror(errno)));
470 goto fail; /* errno set by tdb_brlock */
471 }
472
473 /* we need to zero database if we are the only one with it open */
474 if ((tdb_flags & TDB_CLEAR_IF_FIRST) &&
475 (!tdb->read_only)) {
476 ret = tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK,
477 TDB_LOCK_NOWAIT|TDB_LOCK_PROBE);
478 locked = (ret == 0);
479
480 if (locked) {
481 ret = tdb_brlock(tdb, F_WRLCK, FREELIST_TOP, 0,
482 TDB_LOCK_WAIT);
483 if (ret == -1) {
484 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
485 "tdb_brlock failed for %s: %s\n",
486 name, strerror(errno)));
487 goto fail;
488 }
489 ret = tdb_new_database(tdb, &header, hash_size);
490 if (ret == -1) {
491 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
492 "tdb_new_database failed for "
493 "%s: %s\n", name, strerror(errno)));
494 tdb_unlockall(tdb);
495 goto fail;
496 }
497 ret = tdb_brunlock(tdb, F_WRLCK, FREELIST_TOP, 0);
498 if (ret == -1) {
499 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
500 "tdb_unlockall failed for %s: %s\n",
501 name, strerror(errno)));
502 goto fail;
503 }
504 ret = lseek(tdb->fd, 0, SEEK_SET);
505 if (ret == -1) {
506 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
507 "lseek failed for %s: %s\n",
508 name, strerror(errno)));
509 goto fail;
510 }
511 }
512 }
513
514 errno = 0;
515 if (read(tdb->fd, &header, sizeof(header)) != sizeof(header)
516 || strcmp(header.magic_food, TDB_MAGIC_FOOD) != 0) {
517 if (!(open_flags & O_CREAT) ||
518 tdb_new_database(tdb, &header, hash_size) == -1) {
519 if (errno == 0) {
520 errno = EIO; /* ie bad format or something */
521 }
522 goto fail;
523 }
524 rev = (tdb->flags & TDB_CONVERT);
525 } else if (header.version != TDB_VERSION
526 && !(rev = (header.version==TDB_BYTEREV(TDB_VERSION)))) {
527 /* wrong version */
528 errno = EIO;
529 goto fail;
530 }
531 vp = (unsigned char *)&header.version;
532 vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) |
533 (((uint32_t)vp[2]) << 8) | (uint32_t)vp[3];
534 tdb->flags |= (vertest==TDB_VERSION) ? TDB_BIGENDIAN : 0;
535 if (!rev)
536 tdb->flags &= ~TDB_CONVERT;
537 else {
538 tdb->flags |= TDB_CONVERT;
539 tdb_convert(&header, sizeof(header));
540 }
541
542 /*
543 * We only use st.st_dev and st.st_ino from the raw fstat()
544 * call, everything else needs to use tdb_fstat() in order
545 * to skip tdb->hdr_ofs!
546 */
547 if (fstat(tdb->fd, &st) == -1) {
548 goto fail;
549 }
550 tdb->device = st.st_dev;
551 tdb->inode = st.st_ino;
552 ZERO_STRUCT(st);
553
554 if (header.rwlocks != 0 &&
555 header.rwlocks != TDB_FEATURE_FLAG_MAGIC &&
556 header.rwlocks != TDB_HASH_RWLOCK_MAGIC) {
557 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: spinlocks no longer supported\n"));
558 errno = ENOSYS;
559 goto fail;
560 }
561
562 if (header.hash_size == 0) {
563 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: invalid database: 0 hash_size\n"));
564 errno = ENOSYS;
565 goto fail;
566 }
567
568 tdb->hash_size = header.hash_size;
569
570 if (header.rwlocks == TDB_FEATURE_FLAG_MAGIC) {
571 tdb->feature_flags = header.feature_flags;
572 }
573
574 if (tdb->feature_flags & ~TDB_SUPPORTED_FEATURE_FLAGS) {
575 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: unsupported "
576 "features in tdb %s: 0x%08x (supported: 0x%08x)\n",
577 name, (unsigned)tdb->feature_flags,
578 (unsigned)TDB_SUPPORTED_FEATURE_FLAGS));
579 errno = ENOSYS;
580 goto fail;
581 }
582
583 if (tdb->feature_flags & TDB_FEATURE_FLAG_MUTEX) {
584 if (!tdb_mutex_open_ok(tdb, &header)) {
585 errno = EINVAL;
586 goto fail;
587 }
588
589 /*
590 * We need to remember the hdr_ofs
591 * also for the TDB_NOLOCK case
592 * if the current library doesn't support
593 * mutex locking.
594 */
595 tdb->hdr_ofs = header.mutex_size;
596
597 if ((!(tdb_flags & TDB_CLEAR_IF_FIRST)) && (!tdb->read_only)) {
598 /*
599 * Open an existing mutexed tdb, but without
600 * CLEAR_IF_FIRST. We need to initialize the
601 * mutex array and keep the CLEAR_IF_FIRST
602 * lock locked.
603 */
604 ret = tdb_nest_lock(tdb, ACTIVE_LOCK, F_WRLCK,
605 TDB_LOCK_NOWAIT|TDB_LOCK_PROBE);
606 locked = (ret == 0);
607
608 if (locked) {
609 ret = tdb_mutex_init(tdb);
610 if (ret == -1) {
611 TDB_LOG((tdb,
612 TDB_DEBUG_FATAL,
613 "tdb_open_ex: tdb_mutex_init "
614 "failed for ""%s: %s\n",
615 name, strerror(errno)));
616 goto fail;
617 }
618 }
619 }
620 }
621
622 if ((header.magic1_hash == 0) && (header.magic2_hash == 0)) {
623 /* older TDB without magic hash references */
624 tdb->hash_fn = tdb_old_hash;
625 } else if (!check_header_hash(tdb, &header, !hash_fn,
626 &magic1, &magic2)) {
627 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
628 "%s was not created with %s hash function we are using\n"
629 "magic1_hash[0x%08X %s 0x%08X] "
630 "magic2_hash[0x%08X %s 0x%08X]\n",
631 name, hash_alg,
632 header.magic1_hash,
633 (header.magic1_hash == magic1) ? "==" : "!=",
634 magic1,
635 header.magic2_hash,
636 (header.magic2_hash == magic2) ? "==" : "!=",
637 magic2));
638 errno = EINVAL;
639 goto fail;
640 }
641
642 /* Is it already in the open list? If so, fail. */
643 if (tdb_already_open(tdb->device, tdb->inode)) {
644 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
645 "%s (%d,%d) is already open in this process\n",
646 name, (int)tdb->device, (int)tdb->inode));
647 errno = EBUSY;
648 goto fail;
649 }
650
651 /*
652 * We had tdb_mmap(tdb) here before,
653 * but we need to use tdb_fstat(),
654 * which is triggered from tdb_oob() before calling tdb_mmap().
655 * As this skips tdb->hdr_ofs.
656 */
657 tdb->map_size = 0;
658 ret = tdb_oob(tdb, 0, 1, 0);
659 if (ret == -1) {
660 errno = EIO;
661 goto fail;
662 }
663
664 if (tdb->feature_flags & TDB_FEATURE_FLAG_MUTEX) {
665 if (!(tdb->flags & TDB_NOLOCK)) {
666 ret = tdb_mutex_mmap(tdb);
667 if (ret != 0) {
668 goto fail;
669 }
670 }
671 }
672
673 if (tdb->hash_size > UINT32_MAX/4) {
674 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
675 "hash size %"PRIu32" too large\n", tdb->hash_size));
676 errno = EINVAL;
677 goto fail;
678 }
679
680 ret = tdb_oob(tdb, FREELIST_TOP, 4*tdb->hash_size, 1);
681 if (ret == -1) {
682 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_open_ex: "
683 "hash size %"PRIu32" does not fit\n", tdb->hash_size));
684 errno = EINVAL;
685 goto fail;
686 }
687
688 if (locked) {
689 if (tdb_nest_unlock(tdb, ACTIVE_LOCK, F_WRLCK, false) == -1) {
690 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: "
691 "failed to release ACTIVE_LOCK on %s: %s\n",
692 name, strerror(errno)));
693 goto fail;
694 }
695
696
697 }
698
699 if (locked || (tdb_flags & TDB_CLEAR_IF_FIRST)) {
700 /*
701 * We always need to do this if the CLEAR_IF_FIRST
702 * flag is set, even if we didn't get the initial
703 * exclusive lock as we need to let all other users
704 * know we're using it.
705 */
706
707 ret = tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT);
708 if (ret == -1) {
709 goto fail;
710 }
711 }
712
713 /* if needed, run recovery */
714 if (tdb_transaction_recover(tdb) == -1) {
715 goto fail;
716 }
717
718 #ifdef TDB_TRACE
719 {
720 char tracefile[strlen(name) + 32];
721
722 snprintf(tracefile, sizeof(tracefile),
723 "%s.trace.%li", name, (long)getpid());
724 tdb->tracefd = open(tracefile, O_WRONLY|O_CREAT|O_EXCL, 0600);
725 if (tdb->tracefd >= 0) {
726 tdb_enable_seqnum(tdb);
727 tdb_trace_open(tdb, "tdb_open", hash_size, tdb_flags,
728 open_flags);
729 } else
730 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to open trace file %s!\n", tracefile));
731 }
732 #endif
733
734 internal:
735 /* Internal (memory-only) databases skip all the code above to
736 * do with disk files, and resume here by releasing their
737 * open lock and hooking into the active list. */
738 if (tdb_nest_unlock(tdb, OPEN_LOCK, F_WRLCK, false) == -1) {
739 goto fail;
740 }
741 tdb->next = tdbs;
742 tdbs = tdb;
743 errno = orig_errno;
744 return tdb;
745
746 fail:
747 { int save_errno = errno;
748
749 if (!tdb)
750 return NULL;
751
752 #ifdef TDB_TRACE
753 close(tdb->tracefd);
754 #endif
755 if (tdb->map_ptr) {
756 if (tdb->flags & TDB_INTERNAL)
757 SAFE_FREE(tdb->map_ptr);
758 else
759 tdb_munmap(tdb);
760 }
761 if (tdb->fd != -1)
762 if (close(tdb->fd) != 0)
763 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_open_ex: failed to close tdb->fd on error!\n"));
764 SAFE_FREE(tdb->lockrecs);
765 SAFE_FREE(tdb->name);
766 SAFE_FREE(tdb);
767 errno = save_errno;
768 return NULL;
769 }
770 }
771
772 /*
773 * Set the maximum number of dead records per hash chain
774 */
775
tdb_set_max_dead(struct tdb_context * tdb,int max_dead)776 _PUBLIC_ void tdb_set_max_dead(struct tdb_context *tdb, int max_dead)
777 {
778 tdb->max_dead_records = max_dead;
779 }
780
781 /**
782 * Close a database.
783 *
784 * @returns -1 for error; 0 for success.
785 **/
tdb_close(struct tdb_context * tdb)786 _PUBLIC_ int tdb_close(struct tdb_context *tdb)
787 {
788 struct tdb_context **i;
789 int ret = 0;
790
791 if (tdb->transaction) {
792 tdb_transaction_cancel(tdb);
793 }
794 tdb_trace(tdb, "tdb_close");
795
796 if (tdb->map_ptr) {
797 if (tdb->flags & TDB_INTERNAL)
798 SAFE_FREE(tdb->map_ptr);
799 else
800 tdb_munmap(tdb);
801 }
802
803 tdb_mutex_munmap(tdb);
804
805 SAFE_FREE(tdb->name);
806 if (tdb->fd != -1) {
807 ret = close(tdb->fd);
808 tdb->fd = -1;
809 }
810 SAFE_FREE(tdb->lockrecs);
811
812 /* Remove from contexts list */
813 for (i = &tdbs; *i; i = &(*i)->next) {
814 if (*i == tdb) {
815 *i = tdb->next;
816 break;
817 }
818 }
819
820 #ifdef TDB_TRACE
821 close(tdb->tracefd);
822 #endif
823 memset(tdb, 0, sizeof(*tdb));
824 SAFE_FREE(tdb);
825
826 return ret;
827 }
828
829 /* register a loging function */
tdb_set_logging_function(struct tdb_context * tdb,const struct tdb_logging_context * log_ctx)830 _PUBLIC_ void tdb_set_logging_function(struct tdb_context *tdb,
831 const struct tdb_logging_context *log_ctx)
832 {
833 tdb->log = *log_ctx;
834 }
835
tdb_get_logging_private(struct tdb_context * tdb)836 _PUBLIC_ void *tdb_get_logging_private(struct tdb_context *tdb)
837 {
838 return tdb->log.log_private;
839 }
840
tdb_reopen_internal(struct tdb_context * tdb,bool active_lock)841 static int tdb_reopen_internal(struct tdb_context *tdb, bool active_lock)
842 {
843 #if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
844 !defined(LIBREPLACE_PWRITE_NOT_REPLACED)
845 struct stat st;
846 #endif
847
848 if (tdb->flags & TDB_INTERNAL) {
849 return 0; /* Nothing to do. */
850 }
851
852 if (tdb_have_extra_locks(tdb)) {
853 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed with locks held\n"));
854 goto fail;
855 }
856
857 if (tdb->transaction != 0) {
858 TDB_LOG((tdb, TDB_DEBUG_ERROR, "tdb_reopen: reopen not allowed inside a transaction\n"));
859 goto fail;
860 }
861
862 /* If we have real pread & pwrite, we can skip reopen. */
863 #if !defined(LIBREPLACE_PREAD_NOT_REPLACED) || \
864 !defined(LIBREPLACE_PWRITE_NOT_REPLACED)
865 if (tdb_munmap(tdb) != 0) {
866 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: munmap failed (%s)\n", strerror(errno)));
867 goto fail;
868 }
869 if (close(tdb->fd) != 0)
870 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
871 tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
872 if (tdb->fd == -1) {
873 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: open failed (%s)\n", strerror(errno)));
874 goto fail;
875 }
876 /*
877 * We only use st.st_dev and st.st_ino from the raw fstat()
878 * call, everything else needs to use tdb_fstat() in order
879 * to skip tdb->hdr_ofs!
880 */
881 if (fstat(tdb->fd, &st) != 0) {
882 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: fstat failed (%s)\n", strerror(errno)));
883 goto fail;
884 }
885 if (st.st_ino != tdb->inode || st.st_dev != tdb->device) {
886 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: file dev/inode has changed!\n"));
887 goto fail;
888 }
889 ZERO_STRUCT(st);
890
891 /*
892 * We had tdb_mmap(tdb) here before,
893 * but we need to use tdb_fstat(),
894 * which is triggered from tdb_oob() before calling tdb_mmap().
895 * As this skips tdb->hdr_ofs.
896 */
897 tdb->map_size = 0;
898 if (tdb_oob(tdb, 0, 1, 0) != 0) {
899 goto fail;
900 }
901 #endif /* fake pread or pwrite */
902
903 /* We may still think we hold the active lock. */
904 tdb->num_lockrecs = 0;
905 SAFE_FREE(tdb->lockrecs);
906 tdb->lockrecs_array_length = 0;
907
908 if (active_lock && tdb_nest_lock(tdb, ACTIVE_LOCK, F_RDLCK, TDB_LOCK_WAIT) == -1) {
909 TDB_LOG((tdb, TDB_DEBUG_FATAL, "tdb_reopen: failed to obtain active lock\n"));
910 goto fail;
911 }
912
913 return 0;
914
915 fail:
916 tdb_close(tdb);
917 return -1;
918 }
919
920 /* reopen a tdb - this can be used after a fork to ensure that we have an independent
921 seek pointer from our parent and to re-establish locks */
tdb_reopen(struct tdb_context * tdb)922 _PUBLIC_ int tdb_reopen(struct tdb_context *tdb)
923 {
924 bool active_lock;
925 active_lock = (tdb->flags & (TDB_CLEAR_IF_FIRST|TDB_MUTEX_LOCKING));
926
927 return tdb_reopen_internal(tdb, active_lock);
928 }
929
930 /* reopen all tdb's */
tdb_reopen_all(int parent_longlived)931 _PUBLIC_ int tdb_reopen_all(int parent_longlived)
932 {
933 struct tdb_context *tdb;
934
935 for (tdb=tdbs; tdb; tdb = tdb->next) {
936 bool active_lock;
937
938 active_lock =
939 (tdb->flags & (TDB_CLEAR_IF_FIRST|TDB_MUTEX_LOCKING));
940
941 /*
942 * If the parent is longlived (ie. a
943 * parent daemon architecture), we know
944 * it will keep it's active lock on a
945 * tdb opened with CLEAR_IF_FIRST. Thus
946 * for child processes we don't have to
947 * add an active lock. This is essential
948 * to improve performance on systems that
949 * keep POSIX locks as a non-scalable data
950 * structure in the kernel.
951 */
952 if (parent_longlived) {
953 /* Ensure no clear-if-first. */
954 active_lock = false;
955 }
956
957 if (tdb_reopen_internal(tdb, active_lock) != 0)
958 return -1;
959 }
960
961 return 0;
962 }
963