2 Unix SMB/CIFS implementation.
4 trivial database library
6 Copyright (C) Andrew Tridgell 1999-2005
7 Copyright (C) Paul `Rusty' Russell 2000
8 Copyright (C) Jeremy Allison 2000-2003
10 ** NOTE! The following LGPL license applies to the tdb
11 ** library. This does NOT imply that all of Samba is released
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.
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.
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/>.
28 #include "tdb1_private.h"
30 /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
31 static struct tdb1_context *tdb1s = NULL;
33 /* We use two hashes to double-check they're using the right hash function. */
34 void tdb1_header_hash(struct tdb1_context *tdb,
35 uint32_t *magic1_hash, uint32_t *magic2_hash)
38 uint32_t tdb1_magic = TDB1_MAGIC;
40 hash_key.dptr = (unsigned char *)TDB1_MAGIC_FOOD;
41 hash_key.dsize = sizeof(TDB1_MAGIC_FOOD);
42 *magic1_hash = tdb->hash_fn(&hash_key);
44 hash_key.dptr = (unsigned char *)TDB1_CONV(tdb1_magic);
45 hash_key.dsize = sizeof(tdb1_magic);
46 *magic2_hash = tdb->hash_fn(&hash_key);
48 /* Make sure at least one hash is non-zero! */
49 if (*magic1_hash == 0 && *magic2_hash == 0)
53 /* initialise a new database with a specified hash size */
54 static int tdb1_new_database(struct tdb1_context *tdb, int hash_size)
56 struct tdb1_header *newdb;
60 /* We make it up in memory, then write it out if not internal */
61 size = sizeof(struct tdb1_header) + (hash_size+1)*sizeof(tdb1_off_t);
62 if (!(newdb = (struct tdb1_header *)calloc(size, 1))) {
63 tdb->last_error = TDB_ERR_OOM;
67 /* Fill in the header */
68 newdb->version = TDB1_VERSION;
69 newdb->hash_size = hash_size;
71 tdb1_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
73 /* Make sure older tdbs (which don't check the magic hash fields)
74 * will refuse to open this TDB. */
75 if (tdb->flags & TDB1_INCOMPATIBLE_HASH)
76 newdb->rwlocks = TDB1_HASH_RWLOCK_MAGIC;
78 if (tdb->flags & TDB1_INTERNAL) {
80 tdb->map_ptr = (char *)newdb;
81 memcpy(&tdb->header, newdb, sizeof(tdb->header));
82 /* Convert the `ondisk' version if asked. */
86 if (lseek(tdb->fd, 0, SEEK_SET) == -1)
89 if (ftruncate(tdb->fd, 0) == -1)
92 /* This creates an endian-converted header, as if read from disk */
94 memcpy(&tdb->header, newdb, sizeof(tdb->header));
95 /* Don't endian-convert the magic food! */
96 memcpy(newdb->magic_food, TDB1_MAGIC_FOOD, strlen(TDB1_MAGIC_FOOD)+1);
97 /* we still have "ret == -1" here */
98 if (tdb1_write_all(tdb->fd, newdb, size))
108 static int tdb1_already_open(dev_t device,
111 struct tdb1_context *i;
113 for (i = tdb1s; i; i = i->next) {
114 if (i->device == device && i->inode == ino) {
122 /* open the database, creating it if necessary
124 The open_flags and mode are passed straight to the open call on the
125 database file. A flags value of O_WRONLY is invalid. The hash size
126 is advisory, use zero for a default value.
128 Return is NULL on error, in which case errno is also set. Don't
129 try to call tdb1_error or tdb1_errname, just do strerror(errno).
131 @param name may be NULL for internal databases. */
132 struct tdb1_context *tdb1_open(const char *name, int hash_size, int tdb1_flags,
133 int open_flags, mode_t mode)
135 return tdb1_open_ex(name, hash_size, tdb1_flags, open_flags, mode, NULL, NULL);
138 static bool check_header_hash(struct tdb1_context *tdb,
139 bool default_hash, uint32_t *m1, uint32_t *m2)
141 tdb1_header_hash(tdb, m1, m2);
142 if (tdb->header.magic1_hash == *m1 &&
143 tdb->header.magic2_hash == *m2) {
147 /* If they explicitly set a hash, always respect it. */
151 /* Otherwise, try the other inbuilt hash. */
152 if (tdb->hash_fn == tdb1_old_hash)
153 tdb->hash_fn = tdb1_jenkins_hash;
155 tdb->hash_fn = tdb1_old_hash;
156 return check_header_hash(tdb, false, m1, m2);
159 struct tdb1_context *tdb1_open_ex(const char *name, int hash_size, int tdb1_flags,
160 int open_flags, mode_t mode,
161 const struct tdb1_logging_context *log_ctx,
162 tdb1_hash_func hash_fn)
164 struct tdb1_context *tdb;
166 int rev = 0, locked = 0;
170 const char *hash_alg;
171 uint32_t magic1, magic2;
173 if (!(tdb = (struct tdb1_context *)calloc(1, sizeof *tdb))) {
182 tdb->flags = tdb1_flags;
183 tdb->open_flags = open_flags;
185 tdb->log_fn = log_ctx->log_fn;
186 tdb->log_data = log_ctx->log_private;
190 if (name == NULL && (tdb1_flags & TDB1_INTERNAL)) {
191 name = "__TDB1_INTERNAL__";
195 tdb->name = (char *)"__NULL__";
196 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
197 "tdb1_open_ex: called with name == NULL");
203 /* now make a copy of the name, as the caller memory might went away */
204 if (!(tdb->name = (char *)strdup(name))) {
206 * set the name as the given string, so that tdb1_name() will
207 * work in case of an error.
209 tdb->name = (char *)name;
210 tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
211 "tdb1_open_ex: can't strdup(%s)", name);
218 tdb->hash_fn = hash_fn;
219 hash_alg = "the user defined";
221 /* This controls what we use when creating a tdb. */
222 if (tdb->flags & TDB1_INCOMPATIBLE_HASH) {
223 tdb->hash_fn = tdb1_jenkins_hash;
225 tdb->hash_fn = tdb1_old_hash;
227 hash_alg = "either default";
230 /* cache the page size */
231 tdb->page_size = getpagesize();
232 if (tdb->page_size <= 0) {
233 tdb->page_size = 0x2000;
236 tdb->max_dead_records = (tdb1_flags & TDB1_VOLATILE) ? 5 : 0;
238 if ((open_flags & O_ACCMODE) == O_WRONLY) {
239 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
240 "tdb1_open_ex: can't open tdb %s write-only",
247 hash_size = TDB1_DEFAULT_HASH_SIZE;
248 if ((open_flags & O_ACCMODE) == O_RDONLY) {
250 /* read only databases don't do locking or clear if first */
251 tdb->flags |= TDB1_NOLOCK;
252 tdb->flags &= ~TDB1_CLEAR_IF_FIRST;
255 if ((tdb->flags & TDB1_ALLOW_NESTING) &&
256 (tdb->flags & TDB1_DISALLOW_NESTING)) {
257 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
259 "allow_nesting and disallow_nesting are not allowed together!");
265 * TDB1_ALLOW_NESTING is the default behavior.
266 * Note: this may change in future versions!
268 if (!(tdb->flags & TDB1_DISALLOW_NESTING)) {
269 tdb->flags |= TDB1_ALLOW_NESTING;
272 /* internal databases don't mmap or lock, and start off cleared */
273 if (tdb->flags & TDB1_INTERNAL) {
274 tdb->flags |= (TDB1_NOLOCK | TDB1_NOMMAP);
275 tdb->flags &= ~TDB1_CLEAR_IF_FIRST;
276 if (tdb1_new_database(tdb, hash_size) != 0) {
277 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
278 "tdb1_open_ex: tdb1_new_database failed!");
284 if ((tdb->fd = open(name, open_flags, mode)) == -1) {
285 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
286 "tdb1_open_ex: could not open file %s: %s",
287 name, strerror(errno));
288 goto fail; /* errno set by open(2) */
291 /* on exec, don't inherit the fd */
292 v = fcntl(tdb->fd, F_GETFD, 0);
293 fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
295 /* ensure there is only one process initialising at once */
296 if (tdb1_nest_lock(tdb, TDB1_OPEN_LOCK, F_WRLCK, TDB1_LOCK_WAIT) == -1) {
297 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
298 "tdb1_open_ex: failed to get open lock on %s: %s",
299 name, strerror(errno));
300 goto fail; /* errno set by tdb1_brlock */
303 /* we need to zero database if we are the only one with it open */
304 if ((tdb1_flags & TDB1_CLEAR_IF_FIRST) &&
306 (locked = (tdb1_nest_lock(tdb, TDB1_ACTIVE_LOCK, F_WRLCK, TDB1_LOCK_NOWAIT|TDB1_LOCK_PROBE) == 0))) {
307 open_flags |= O_CREAT;
308 if (ftruncate(tdb->fd, 0) == -1) {
309 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
311 "failed to truncate %s: %s",
312 name, strerror(errno));
313 goto fail; /* errno set by ftruncate */
318 if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
319 || strcmp(tdb->header.magic_food, TDB1_MAGIC_FOOD) != 0) {
320 if (!(open_flags & O_CREAT) || tdb1_new_database(tdb, hash_size) == -1) {
322 errno = EIO; /* ie bad format or something */
326 rev = (tdb->flags & TDB1_CONVERT);
327 } else if (tdb->header.version != TDB1_VERSION
328 && !(rev = (tdb->header.version==TDB1_BYTEREV(TDB1_VERSION)))) {
333 vp = (unsigned char *)&tdb->header.version;
334 vertest = (((uint32_t)vp[0]) << 24) | (((uint32_t)vp[1]) << 16) |
335 (((uint32_t)vp[2]) << 8) | (uint32_t)vp[3];
336 tdb->flags |= (vertest==TDB1_VERSION) ? TDB1_BIGENDIAN : 0;
338 tdb->flags &= ~TDB1_CONVERT;
340 tdb->flags |= TDB1_CONVERT;
341 tdb1_convert(&tdb->header, sizeof(tdb->header));
343 if (fstat(tdb->fd, &st) == -1)
346 if (tdb->header.rwlocks != 0 &&
347 tdb->header.rwlocks != TDB1_HASH_RWLOCK_MAGIC) {
348 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
349 "tdb1_open_ex: spinlocks no longer supported");
353 if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
354 /* older TDB without magic hash references */
355 tdb->hash_fn = tdb1_old_hash;
356 } else if (!check_header_hash(tdb, !hash_fn, &magic1, &magic2)) {
357 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_USE_ERROR,
359 "%s was not created with %s hash function we are using\n"
360 "magic1_hash[0x%08X %s 0x%08X] "
361 "magic2_hash[0x%08X %s 0x%08X]",
363 tdb->header.magic1_hash,
364 (tdb->header.magic1_hash == magic1) ? "==" : "!=",
366 tdb->header.magic2_hash,
367 (tdb->header.magic2_hash == magic2) ? "==" : "!=",
373 /* Is it already in the open list? If so, fail. */
374 if (tdb1_already_open(st.st_dev, st.st_ino)) {
375 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
377 "%s (%d,%d) is already open in this process",
378 name, (int)st.st_dev, (int)st.st_ino);
383 tdb->map_size = st.st_size;
384 tdb->device = st.st_dev;
385 tdb->inode = st.st_ino;
388 if (tdb1_nest_unlock(tdb, TDB1_ACTIVE_LOCK, F_WRLCK) == -1) {
389 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
391 "failed to release ACTIVE_LOCK on %s: %s",
392 name, strerror(errno));
398 /* We always need to do this if the CLEAR_IF_FIRST flag is set, even if
399 we didn't get the initial exclusive lock as we need to let all other
400 users know we're using it. */
402 if (tdb1_flags & TDB1_CLEAR_IF_FIRST) {
403 /* leave this lock in place to indicate it's in use */
404 if (tdb1_nest_lock(tdb, TDB1_ACTIVE_LOCK, F_RDLCK, TDB1_LOCK_WAIT) == -1) {
409 /* if needed, run recovery */
410 if (tdb1_transaction_recover(tdb) == -1) {
415 /* Internal (memory-only) databases skip all the code above to
416 * do with disk files, and resume here by releasing their
417 * open lock and hooking into the active list. */
418 if (tdb1_nest_unlock(tdb, TDB1_OPEN_LOCK, F_WRLCK) == -1) {
426 { int save_errno = errno;
432 if (tdb->flags & TDB1_INTERNAL)
433 SAFE_FREE(tdb->map_ptr);
438 if (close(tdb->fd) != 0)
439 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
440 "tdb1_open_ex: failed to close tdb->fd on error!");
441 SAFE_FREE(tdb->lockrecs);
442 SAFE_FREE(tdb->name);
450 * Set the maximum number of dead records per hash chain
453 void tdb1_set_max_dead(struct tdb1_context *tdb, int max_dead)
455 tdb->max_dead_records = max_dead;
461 * @returns -1 for error; 0 for success.
463 int tdb1_close(struct tdb1_context *tdb)
465 struct tdb1_context **i;
468 if (tdb->transaction) {
469 tdb1_transaction_cancel(tdb);
473 if (tdb->flags & TDB1_INTERNAL)
474 SAFE_FREE(tdb->map_ptr);
478 SAFE_FREE(tdb->name);
480 ret = close(tdb->fd);
483 SAFE_FREE(tdb->lockrecs);
485 /* Remove from contexts list */
486 for (i = &tdb1s; *i; i = &(*i)->next) {
493 memset(tdb, 0, sizeof(*tdb));