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)
37 uint32_t tdb1_magic = TDB1_MAGIC;
39 *magic1_hash = tdb_hash(tdb, TDB_MAGIC_FOOD, sizeof(TDB_MAGIC_FOOD));
40 *magic2_hash = tdb_hash(tdb, TDB1_CONV(tdb1_magic), sizeof(tdb1_magic));
42 /* Make sure at least one hash is non-zero! */
43 if (*magic1_hash == 0 && *magic2_hash == 0)
47 /* initialise a new database with a specified hash size */
48 static int tdb1_new_database(struct tdb1_context *tdb, int hash_size)
50 struct tdb1_header *newdb;
54 /* We make it up in memory, then write it out if not internal */
55 size = sizeof(struct tdb1_header) + (hash_size+1)*sizeof(tdb1_off_t);
56 if (!(newdb = (struct tdb1_header *)calloc(size, 1))) {
57 tdb->last_error = TDB_ERR_OOM;
61 /* Fill in the header */
62 newdb->version = TDB1_VERSION;
63 newdb->hash_size = hash_size;
65 tdb1_header_hash(tdb, &newdb->magic1_hash, &newdb->magic2_hash);
67 /* Make sure older tdbs (which don't check the magic hash fields)
68 * will refuse to open this TDB. */
69 if (tdb->hash_fn == tdb1_incompatible_hash)
70 newdb->rwlocks = TDB1_HASH_RWLOCK_MAGIC;
72 if (tdb->flags & TDB_INTERNAL) {
74 tdb->file->map_size = size;
75 tdb->file->map_ptr = (char *)newdb;
76 memcpy(&tdb->header, newdb, sizeof(tdb->header));
77 /* Convert the `ondisk' version if asked. */
81 if (lseek(tdb->file->fd, 0, SEEK_SET) == -1)
84 if (ftruncate(tdb->file->fd, 0) == -1)
87 /* This creates an endian-converted header, as if read from disk */
89 memcpy(&tdb->header, newdb, sizeof(tdb->header));
90 /* Don't endian-convert the magic food! */
91 memcpy(newdb->magic_food, TDB_MAGIC_FOOD, strlen(TDB_MAGIC_FOOD)+1);
92 /* we still have "ret == -1" here */
93 if (tdb1_write_all(tdb->file->fd, newdb, size))
103 static int tdb1_already_open(dev_t device,
106 struct tdb1_context *i;
108 for (i = tdb1s; i; i = i->next) {
109 if (i->file->device == device && i->file->inode == ino) {
117 /* open the database, creating it if necessary
119 The open_flags and mode are passed straight to the open call on the
120 database file. A flags value of O_WRONLY is invalid. The hash size
121 is advisory, use zero for a default value.
123 Return is NULL on error, in which case errno is also set. Don't
124 try to call tdb1_error or tdb1_errname, just do strerror(errno).
126 @param name may be NULL for internal databases. */
127 struct tdb1_context *tdb1_open(const char *name, int hash_size, int tdb1_flags,
128 int open_flags, mode_t mode)
130 return tdb1_open_ex(name, hash_size, tdb1_flags, open_flags, mode, NULL, NULL);
133 static bool hash_correct(struct tdb1_context *tdb,
134 uint32_t *m1, uint32_t *m2)
136 tdb1_header_hash(tdb, m1, m2);
137 return (tdb->header.magic1_hash == *m1 &&
138 tdb->header.magic2_hash == *m2);
141 static bool check_header_hash(struct tdb1_context *tdb,
142 uint32_t *m1, uint32_t *m2)
144 if (hash_correct(tdb, m1, m2))
147 /* If they use one inbuilt, try the other inbuilt hash. */
148 if (tdb->hash_fn == tdb1_old_hash)
149 tdb->hash_fn = tdb1_incompatible_hash;
150 else if (tdb->hash_fn == tdb1_incompatible_hash)
151 tdb->hash_fn = tdb1_old_hash;
154 return hash_correct(tdb, m1, m2);
157 struct tdb1_context *tdb1_open_ex(const char *name, int hash_size, int tdb1_flags,
158 int open_flags, mode_t mode,
159 const struct tdb1_logging_context *log_ctx,
160 tdb1_hash_func hash_fn)
162 struct tdb1_context *tdb;
166 const char *hash_alg;
167 uint32_t magic1, magic2;
169 if (!(tdb = (struct tdb1_context *)calloc(1, sizeof *tdb))) {
174 tdb->file = calloc(1, sizeof *tdb->file);
183 tdb->file->map_ptr = NULL;
184 tdb->flags = tdb1_flags|TDB_VERSION1;
185 tdb->open_flags = open_flags;
186 tdb->lock_fn = tdb_fcntl_lock;
187 tdb->unlock_fn = tdb_fcntl_unlock;
189 tdb->log_fn = log_ctx->log_fn;
190 tdb->log_data = log_ctx->log_private;
194 if (name == NULL && (tdb1_flags & TDB_INTERNAL)) {
195 name = "__TDB1_INTERNAL__";
199 tdb->name = (char *)"__NULL__";
200 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
201 "tdb1_open_ex: called with name == NULL");
207 /* now make a copy of the name, as the caller memory might went away */
208 if (!(tdb->name = (char *)strdup(name))) {
210 * set the name as the given string, so that tdb1_name() will
211 * work in case of an error.
213 tdb->name = (char *)name;
214 tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
215 "tdb1_open_ex: can't strdup(%s)", name);
223 tdb->hash_fn = hash_fn;
224 if (hash_fn == tdb1_incompatible_hash)
225 hash_alg = "tdb1_incompatible_hash";
227 hash_alg = "the user defined";
229 tdb->hash_fn = tdb1_old_hash;
230 hash_alg = "default";
233 /* cache the page size */
234 tdb->page_size = getpagesize();
235 if (tdb->page_size <= 0) {
236 tdb->page_size = 0x2000;
239 /* FIXME: Used to be 5 for TDB_VOLATILE. */
240 tdb->max_dead_records = 0;
242 if ((open_flags & O_ACCMODE) == O_WRONLY) {
243 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
244 "tdb1_open_ex: can't open tdb %s write-only",
251 hash_size = TDB1_DEFAULT_HASH_SIZE;
252 if ((open_flags & O_ACCMODE) == O_RDONLY) {
253 tdb->flags |= TDB_RDONLY;
254 /* read only databases don't do locking */
255 tdb->flags |= TDB_NOLOCK;
258 /* internal databases don't mmap or lock, and start off cleared */
259 if (tdb->flags & TDB_INTERNAL) {
260 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
261 if (tdb1_new_database(tdb, hash_size) != 0) {
262 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
263 "tdb1_open_ex: tdb1_new_database failed!");
269 if ((tdb->file->fd = open(name, open_flags, mode)) == -1) {
270 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
271 "tdb1_open_ex: could not open file %s: %s",
272 name, strerror(errno));
273 goto fail; /* errno set by open(2) */
276 /* on exec, don't inherit the fd */
277 v = fcntl(tdb->file->fd, F_GETFD, 0);
278 fcntl(tdb->file->fd, F_SETFD, v | FD_CLOEXEC);
280 /* ensure there is only one process initialising at once */
281 if (tdb1_nest_lock(tdb, TDB1_OPEN_LOCK, F_WRLCK, TDB_LOCK_WAIT) == -1) {
282 tdb_logerr(tdb, tdb->last_error, TDB_LOG_ERROR,
283 "tdb1_open_ex: failed to get open lock on %s: %s",
284 name, strerror(errno));
285 goto fail; /* errno set by tdb1_brlock */
289 if (read(tdb->file->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
290 || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0) {
291 if (!(open_flags & O_CREAT) || tdb1_new_database(tdb, hash_size) == -1) {
293 errno = EIO; /* ie bad format or something */
297 rev = (tdb->flags & TDB_CONVERT);
298 } else if (tdb->header.version != TDB1_VERSION
299 && !(rev = (tdb->header.version==TDB1_BYTEREV(TDB1_VERSION)))) {
305 tdb->flags &= ~TDB_CONVERT;
307 tdb->flags |= TDB_CONVERT;
308 tdb1_convert(&tdb->header, sizeof(tdb->header));
310 if (fstat(tdb->file->fd, &st) == -1)
313 if (tdb->header.rwlocks != 0 &&
314 tdb->header.rwlocks != TDB1_HASH_RWLOCK_MAGIC) {
315 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_ERROR,
316 "tdb1_open_ex: spinlocks no longer supported");
320 if ((tdb->header.magic1_hash == 0) && (tdb->header.magic2_hash == 0)) {
321 /* older TDB without magic hash references */
322 tdb->hash_fn = tdb1_old_hash;
323 } else if (!check_header_hash(tdb, &magic1, &magic2)) {
324 tdb_logerr(tdb, TDB_ERR_CORRUPT, TDB_LOG_USE_ERROR,
326 "%s was not created with %s hash function we are using\n"
327 "magic1_hash[0x%08X %s 0x%08X] "
328 "magic2_hash[0x%08X %s 0x%08X]",
330 tdb->header.magic1_hash,
331 (tdb->header.magic1_hash == magic1) ? "==" : "!=",
333 tdb->header.magic2_hash,
334 (tdb->header.magic2_hash == magic2) ? "==" : "!=",
340 /* Is it already in the open list? If so, fail. */
341 if (tdb1_already_open(st.st_dev, st.st_ino)) {
342 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
344 "%s (%d,%d) is already open in this process",
345 name, (int)st.st_dev, (int)st.st_ino);
350 tdb->file->map_size = st.st_size;
351 tdb->file->device = st.st_dev;
352 tdb->file->inode = st.st_ino;
355 /* if needed, run recovery */
356 if (tdb1_transaction_recover(tdb) == -1) {
361 /* Internal (memory-only) databases skip all the code above to
362 * do with disk files, and resume here by releasing their
363 * open lock and hooking into the active list. */
364 if (tdb1_nest_unlock(tdb, TDB1_OPEN_LOCK, F_WRLCK) == -1) {
372 { int save_errno = errno;
377 if (tdb->file->map_ptr) {
378 if (tdb->flags & TDB_INTERNAL)
379 SAFE_FREE(tdb->file->map_ptr);
383 if (tdb->file->fd != -1)
384 if (close(tdb->file->fd) != 0)
385 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
386 "tdb1_open_ex: failed to close tdb->fd on error!");
388 SAFE_FREE(tdb->file->lockrecs);
389 SAFE_FREE(tdb->file);
391 SAFE_FREE(tdb->name);
399 * Set the maximum number of dead records per hash chain
402 void tdb1_set_max_dead(struct tdb1_context *tdb, int max_dead)
404 tdb->max_dead_records = max_dead;
410 * @returns -1 for error; 0 for success.
412 int tdb1_close(struct tdb1_context *tdb)
414 struct tdb1_context **i;
417 if (tdb->transaction) {
418 tdb1_transaction_cancel(tdb);
421 if (tdb->file->map_ptr) {
422 if (tdb->flags & TDB_INTERNAL)
423 SAFE_FREE(tdb->file->map_ptr);
427 SAFE_FREE(tdb->name);
428 if (tdb->file->fd != -1) {
429 ret = close(tdb->file->fd);
432 SAFE_FREE(tdb->file->lockrecs);
433 SAFE_FREE(tdb->file);
435 /* Remove from contexts list */
436 for (i = &tdb1s; *i; i = &(*i)->next) {
443 memset(tdb, 0, sizeof(*tdb));