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 *)TDB_MAGIC_FOOD;
41 hash_key.dsize = sizeof(TDB_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->hash_fn == tdb1_incompatible_hash)
76 newdb->rwlocks = TDB1_HASH_RWLOCK_MAGIC;
78 if (tdb->flags & TDB_INTERNAL) {
80 tdb->file->map_size = size;
81 tdb->file->map_ptr = (char *)newdb;
82 memcpy(&tdb->header, newdb, sizeof(tdb->header));
83 /* Convert the `ondisk' version if asked. */
87 if (lseek(tdb->file->fd, 0, SEEK_SET) == -1)
90 if (ftruncate(tdb->file->fd, 0) == -1)
93 /* This creates an endian-converted header, as if read from disk */
95 memcpy(&tdb->header, newdb, sizeof(tdb->header));
96 /* Don't endian-convert the magic food! */
97 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
98 /* we still have "ret == -1" here */
99 if (tdb1_write_all(tdb->file->fd, newdb, size))
109 static int tdb1_already_open(dev_t device,
112 struct tdb1_context *i;
114 for (i = tdb1s; i; i = i->next) {
115 if (i->file->device == device && i->file->inode == ino) {
123 /* open the database, creating it if necessary
125 The open_flags and mode are passed straight to the open call on the
126 database file. A flags value of O_WRONLY is invalid. The hash size
127 is advisory, use zero for a default value.
129 Return is NULL on error, in which case errno is also set. Don't
130 try to call tdb1_error or tdb1_errname, just do strerror(errno).
132 @param name may be NULL for internal databases. */
133 struct tdb1_context *tdb1_open(const char *name, int hash_size, int tdb1_flags,
134 int open_flags, mode_t mode)
136 return tdb1_open_ex(name, hash_size, tdb1_flags, open_flags, mode, NULL, NULL);
139 static bool hash_correct(struct tdb1_context *tdb,
140 uint32_t *m1, uint32_t *m2)
142 tdb1_header_hash(tdb, m1, m2);
143 return (tdb->header.magic1_hash == *m1 &&
144 tdb->header.magic2_hash == *m2);
147 static bool check_header_hash(struct tdb1_context *tdb,
148 uint32_t *m1, uint32_t *m2)
150 if (hash_correct(tdb, m1, m2))
153 /* If they use one inbuilt, try the other inbuilt hash. */
154 if (tdb->hash_fn == tdb1_old_hash)
155 tdb->hash_fn = tdb1_incompatible_hash;
156 else if (tdb->hash_fn == tdb1_incompatible_hash)
157 tdb->hash_fn = tdb1_old_hash;
160 return hash_correct(tdb, m1, m2);
163 struct tdb1_context *tdb1_open_ex(const char *name, int hash_size, int tdb1_flags,
164 int open_flags, mode_t mode,
165 const struct tdb1_logging_context *log_ctx,
166 tdb1_hash_func hash_fn)
168 struct tdb1_context *tdb;
172 const char *hash_alg;
173 uint32_t magic1, magic2;
175 if (!(tdb = (struct tdb1_context *)calloc(1, sizeof *tdb))) {
180 tdb->file = calloc(1, sizeof *tdb->file);
189 tdb->file->map_ptr = NULL;
190 tdb->flags = tdb1_flags|TDB_VERSION1;
191 tdb->open_flags = open_flags;
193 tdb->log_fn = log_ctx->log_fn;
194 tdb->log_data = log_ctx->log_private;
198 if (name == NULL && (tdb1_flags & TDB_INTERNAL)) {
199 name = "__TDB1_INTERNAL__";
203 tdb->name = (char *)"__NULL__";
204 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
205 "tdb1_open_ex: called with name == NULL");
211 /* now make a copy of the name, as the caller memory might went away */
212 if (!(tdb->name = (char *)strdup(name))) {
214 * set the name as the given string, so that tdb1_name() will
215 * work in case of an error.
217 tdb->name = (char *)name;
218 tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
219 "tdb1_open_ex: can't strdup(%s)", name);
226 tdb->hash_fn = hash_fn;
227 if (hash_fn == tdb1_incompatible_hash)
228 hash_alg = "tdb1_incompatible_hash";
230 hash_alg = "the user defined";
232 tdb->hash_fn = tdb1_old_hash;
233 hash_alg = "default";
236 /* cache the page size */
237 tdb->page_size = getpagesize();
238 if (tdb->page_size <= 0) {
239 tdb->page_size = 0x2000;
242 /* FIXME: Used to be 5 for TDB_VOLATILE. */
243 tdb->max_dead_records = 0;
245 if ((open_flags & O_ACCMODE) == O_WRONLY) {
246 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
247 "tdb1_open_ex: can't open tdb %s write-only",
254 hash_size = TDB1_DEFAULT_HASH_SIZE;
255 if ((open_flags & O_ACCMODE) == O_RDONLY) {
257 /* read only databases don't do locking */
258 tdb->flags |= TDB_NOLOCK;
261 /* internal databases don't mmap or lock, and start off cleared */
262 if (tdb->flags & TDB_INTERNAL) {
263 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
264 if (tdb1_new_database(tdb, hash_size) != 0) {
265 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
266 "tdb1_open_ex: tdb1_new_database failed!");
272 if ((tdb->file->fd = open(name, open_flags, mode)) == -1) {
273 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
274 "tdb1_open_ex: could not open file %s: %s",
275 name, strerror(errno));
276 goto fail; /* errno set by open(2) */
279 /* on exec, don't inherit the fd */
280 v = fcntl(tdb->file->fd, F_GETFD, 0);
281 fcntl(tdb->file->fd, F_SETFD, v | FD_CLOEXEC);
283 /* ensure there is only one process initialising at once */
284 if (tdb1_nest_lock(tdb, TDB1_OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
285 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
286 "tdb1_open_ex: failed to get open lock on %s: %s",
287 name, strerror(errno));
288 goto fail; /* errno set by tdb1_brlock */
292 if (read(tdb->file->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
293 || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0) {
294 if (!(open_flags & O_CREAT) || tdb1_new_database(tdb, hash_size) == -1) {
296 errno = EIO; /* ie bad format or something */
300 rev = (tdb->flags & TDB_CONVERT);
301 } else if (tdb->header.version != TDB1_VERSION
302 && !(rev = (tdb->header.version==TDB1_BYTEREV(TDB1_VERSION)))) {
308 tdb->flags &= ~TDB_CONVERT;
310 tdb->flags |= TDB_CONVERT;
311 tdb1_convert(&tdb->header, sizeof(tdb->header));
313 if (fstat(tdb->file->fd, &st) == -1)
316 if (tdb->header.rwlocks != 0 &&
317 tdb->header.rwlocks != TDB1_HASH_RWLOCK_MAGIC) {
318 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
319 "tdb1_open_ex: spinlocks no longer supported");
323 if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
324 /* older TDB without magic hash references */
325 tdb->hash_fn = tdb1_old_hash;
326 } else if (!check_header_hash(tdb, &magic1, &magic2)) {
327 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_USE_ERROR,
329 "%s was not created with %s hash function we are using\n"
330 "magic1_hash[0x%08X %s 0x%08X] "
331 "magic2_hash[0x%08X %s 0x%08X]",
333 tdb->header.magic1_hash,
334 (tdb->header.magic1_hash == magic1) ? "==" : "!=",
336 tdb->header.magic2_hash,
337 (tdb->header.magic2_hash == magic2) ? "==" : "!=",
343 /* Is it already in the open list? If so, fail. */
344 if (tdb1_already_open(st.st_dev, st.st_ino)) {
345 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
347 "%s (%d,%d) is already open in this process",
348 name, (int)st.st_dev, (int)st.st_ino);
353 tdb->file->map_size = st.st_size;
354 tdb->file->device = st.st_dev;
355 tdb->file->inode = st.st_ino;
358 /* if needed, run recovery */
359 if (tdb1_transaction_recover(tdb) == -1) {
364 /* Internal (memory-only) databases skip all the code above to
365 * do with disk files, and resume here by releasing their
366 * open lock and hooking into the active list. */
367 if (tdb1_nest_unlock(tdb, TDB1_OPEN_LOCK, F_WRLCK) == -1) {
375 { int save_errno = errno;
380 if (tdb->file->map_ptr) {
381 if (tdb->flags & TDB_INTERNAL)
382 SAFE_FREE(tdb->file->map_ptr);
386 if (tdb->file->fd != -1)
387 if (close(tdb->file->fd) != 0)
388 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
389 "tdb1_open_ex: failed to close tdb->fd on error!");
391 SAFE_FREE(tdb->file->lockrecs);
392 SAFE_FREE(tdb->file);
394 SAFE_FREE(tdb->name);
402 * Set the maximum number of dead records per hash chain
405 void tdb1_set_max_dead(struct tdb1_context *tdb, int max_dead)
407 tdb->max_dead_records = max_dead;
413 * @returns -1 for error; 0 for success.
415 int tdb1_close(struct tdb1_context *tdb)
417 struct tdb1_context **i;
420 if (tdb->transaction) {
421 tdb1_transaction_cancel(tdb);
424 if (tdb->file->map_ptr) {
425 if (tdb->flags & TDB_INTERNAL)
426 SAFE_FREE(tdb->file->map_ptr);
430 SAFE_FREE(tdb->name);
431 if (tdb->file->fd != -1) {
432 ret = close(tdb->file->fd);
435 SAFE_FREE(tdb->file->lockrecs);
436 SAFE_FREE(tdb->file);
438 /* Remove from contexts list */
439 for (i = &tdb1s; *i; i = &(*i)->next) {
446 memset(tdb, 0, sizeof(*tdb));