s3-spoolss: Use a global variable for the pool
[Samba/vl.git] / lib / tdb2 / open.c
blobc35598cdcce5a0625434984a9139e1d41c8d4645
1 #include "private.h"
2 #include <ccan/hash/hash.h>
3 #include <assert.h>
5 /* all lock info, to detect double-opens (fcntl file don't nest!) */
6 static struct tdb_file *files = NULL;
8 static struct tdb_file *find_file(dev_t device, ino_t ino)
10 struct tdb_file *i;
12 for (i = files; i; i = i->next) {
13 if (i->device == device && i->inode == ino) {
14 i->refcnt++;
15 break;
18 return i;
21 static bool read_all(int fd, void *buf, size_t len)
23 while (len) {
24 ssize_t ret;
25 ret = read(fd, buf, len);
26 if (ret < 0)
27 return false;
28 if (ret == 0) {
29 /* ETOOSHORT? */
30 errno = EWOULDBLOCK;
31 return false;
33 buf = (char *)buf + ret;
34 len -= ret;
36 return true;
39 static uint64_t random_number(struct tdb_context *tdb)
41 int fd;
42 uint64_t ret = 0;
43 struct timeval now;
45 fd = open("/dev/urandom", O_RDONLY);
46 if (fd >= 0) {
47 if (read_all(fd, &ret, sizeof(ret))) {
48 close(fd);
49 return ret;
51 close(fd);
53 /* FIXME: Untested! Based on Wikipedia protocol description! */
54 fd = open("/dev/egd-pool", O_RDWR);
55 if (fd >= 0) {
56 /* Command is 1, next byte is size we want to read. */
57 char cmd[2] = { 1, sizeof(uint64_t) };
58 if (write(fd, cmd, sizeof(cmd)) == sizeof(cmd)) {
59 char reply[1 + sizeof(uint64_t)];
60 int r = read(fd, reply, sizeof(reply));
61 if (r > 1) {
62 /* Copy at least some bytes. */
63 memcpy(&ret, reply+1, r - 1);
64 if (reply[0] == sizeof(uint64_t)
65 && r == sizeof(reply)) {
66 close(fd);
67 return ret;
71 close(fd);
74 /* Fallback: pid and time. */
75 gettimeofday(&now, NULL);
76 ret = getpid() * 100132289ULL + now.tv_sec * 1000000ULL + now.tv_usec;
77 tdb_logerr(tdb, TDB_SUCCESS, TDB_LOG_WARNING,
78 "tdb_open: random from getpid and time");
79 return ret;
82 struct new_database {
83 struct tdb_header hdr;
84 struct tdb_freetable ftable;
87 /* initialise a new database */
88 static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
89 struct tdb_attribute_seed *seed,
90 struct tdb_header *hdr)
92 /* We make it up in memory, then write it out if not internal */
93 struct new_database newdb;
94 unsigned int magic_len;
95 ssize_t rlen;
96 enum TDB_ERROR ecode;
98 /* Fill in the header */
99 newdb.hdr.version = TDB_VERSION;
100 if (seed)
101 newdb.hdr.hash_seed = seed->seed;
102 else
103 newdb.hdr.hash_seed = random_number(tdb);
104 newdb.hdr.hash_test = TDB_HASH_MAGIC;
105 newdb.hdr.hash_test = tdb->hash_fn(&newdb.hdr.hash_test,
106 sizeof(newdb.hdr.hash_test),
107 newdb.hdr.hash_seed,
108 tdb->hash_data);
109 newdb.hdr.recovery = 0;
110 newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
111 newdb.hdr.seqnum = 0;
112 memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
113 /* Initial hashes are empty. */
114 memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
116 /* Free is empty. */
117 newdb.hdr.free_table = offsetof(struct new_database, ftable);
118 memset(&newdb.ftable, 0, sizeof(newdb.ftable));
119 ecode = set_header(NULL, &newdb.ftable.hdr, TDB_FTABLE_MAGIC, 0,
120 sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
121 sizeof(newdb.ftable) - sizeof(newdb.ftable.hdr),
123 if (ecode != TDB_SUCCESS) {
124 return ecode;
127 /* Magic food */
128 memset(newdb.hdr.magic_food, 0, sizeof(newdb.hdr.magic_food));
129 strcpy(newdb.hdr.magic_food, TDB_MAGIC_FOOD);
131 /* This creates an endian-converted database, as if read from disk */
132 magic_len = sizeof(newdb.hdr.magic_food);
133 tdb_convert(tdb,
134 (char *)&newdb.hdr + magic_len, sizeof(newdb) - magic_len);
136 *hdr = newdb.hdr;
138 if (tdb->flags & TDB_INTERNAL) {
139 tdb->file->map_size = sizeof(newdb);
140 tdb->file->map_ptr = malloc(tdb->file->map_size);
141 if (!tdb->file->map_ptr) {
142 return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
143 "tdb_new_database:"
144 " failed to allocate");
146 memcpy(tdb->file->map_ptr, &newdb, tdb->file->map_size);
147 return TDB_SUCCESS;
149 if (lseek(tdb->file->fd, 0, SEEK_SET) == -1) {
150 return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
151 "tdb_new_database:"
152 " failed to seek: %s", strerror(errno));
155 if (ftruncate(tdb->file->fd, 0) == -1) {
156 return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
157 "tdb_new_database:"
158 " failed to truncate: %s", strerror(errno));
161 rlen = write(tdb->file->fd, &newdb, sizeof(newdb));
162 if (rlen != sizeof(newdb)) {
163 if (rlen >= 0)
164 errno = ENOSPC;
165 return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
166 "tdb_new_database: %zi writing header: %s",
167 rlen, strerror(errno));
169 return TDB_SUCCESS;
172 static enum TDB_ERROR tdb_new_file(struct tdb_context *tdb)
174 tdb->file = malloc(sizeof(*tdb->file));
175 if (!tdb->file)
176 return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
177 "tdb_open: cannot alloc tdb_file structure");
178 tdb->file->num_lockrecs = 0;
179 tdb->file->lockrecs = NULL;
180 tdb->file->allrecord_lock.count = 0;
181 tdb->file->refcnt = 1;
182 return TDB_SUCCESS;
185 enum TDB_ERROR tdb_set_attribute(struct tdb_context *tdb,
186 const union tdb_attribute *attr)
188 switch (attr->base.attr) {
189 case TDB_ATTRIBUTE_LOG:
190 tdb->log_fn = attr->log.fn;
191 tdb->log_data = attr->log.data;
192 break;
193 case TDB_ATTRIBUTE_HASH:
194 case TDB_ATTRIBUTE_SEED:
195 case TDB_ATTRIBUTE_OPENHOOK:
196 return tdb->last_error
197 = tdb_logerr(tdb, TDB_ERR_EINVAL,
198 TDB_LOG_USE_ERROR,
199 "tdb_set_attribute:"
200 " cannot set %s after opening",
201 attr->base.attr == TDB_ATTRIBUTE_HASH
202 ? "TDB_ATTRIBUTE_HASH"
203 : attr->base.attr == TDB_ATTRIBUTE_SEED
204 ? "TDB_ATTRIBUTE_SEED"
205 : "TDB_ATTRIBUTE_OPENHOOK");
206 case TDB_ATTRIBUTE_STATS:
207 return tdb->last_error
208 = tdb_logerr(tdb, TDB_ERR_EINVAL,
209 TDB_LOG_USE_ERROR,
210 "tdb_set_attribute:"
211 " cannot set TDB_ATTRIBUTE_STATS");
212 case TDB_ATTRIBUTE_FLOCK:
213 tdb->lock_fn = attr->flock.lock;
214 tdb->unlock_fn = attr->flock.unlock;
215 tdb->lock_data = attr->flock.data;
216 break;
217 default:
218 return tdb->last_error
219 = tdb_logerr(tdb, TDB_ERR_EINVAL,
220 TDB_LOG_USE_ERROR,
221 "tdb_set_attribute:"
222 " unknown attribute type %u",
223 attr->base.attr);
225 return TDB_SUCCESS;
228 static uint64_t jenkins_hash(const void *key, size_t length, uint64_t seed,
229 void *unused)
231 uint64_t ret;
232 /* hash64_stable assumes lower bits are more important; they are a
233 * slightly better hash. We use the upper bits first, so swap them. */
234 ret = hash64_stable((const unsigned char *)key, length, seed);
235 return (ret >> 32) | (ret << 32);
238 enum TDB_ERROR tdb_get_attribute(struct tdb_context *tdb,
239 union tdb_attribute *attr)
241 switch (attr->base.attr) {
242 case TDB_ATTRIBUTE_LOG:
243 if (!tdb->log_fn)
244 return tdb->last_error = TDB_ERR_NOEXIST;
245 attr->log.fn = tdb->log_fn;
246 attr->log.data = tdb->log_data;
247 break;
248 case TDB_ATTRIBUTE_HASH:
249 attr->hash.fn = tdb->hash_fn;
250 attr->hash.data = tdb->hash_data;
251 break;
252 case TDB_ATTRIBUTE_SEED:
253 attr->seed.seed = tdb->hash_seed;
254 break;
255 case TDB_ATTRIBUTE_OPENHOOK:
256 return tdb->last_error
257 = tdb_logerr(tdb, TDB_ERR_EINVAL,
258 TDB_LOG_USE_ERROR,
259 "tdb_get_attribute:"
260 " cannot get TDB_ATTRIBUTE_OPENHOOK");
261 case TDB_ATTRIBUTE_STATS: {
262 size_t size = attr->stats.size;
263 if (size > tdb->stats.size)
264 size = tdb->stats.size;
265 memcpy(&attr->stats, &tdb->stats, size);
266 break;
268 case TDB_ATTRIBUTE_FLOCK:
269 attr->flock.lock = tdb->lock_fn;
270 attr->flock.unlock = tdb->unlock_fn;
271 attr->flock.data = tdb->lock_data;
272 break;
273 default:
274 return tdb->last_error
275 = tdb_logerr(tdb, TDB_ERR_EINVAL,
276 TDB_LOG_USE_ERROR,
277 "tdb_get_attribute:"
278 " unknown attribute type %u",
279 attr->base.attr);
281 attr->base.next = NULL;
282 return TDB_SUCCESS;
285 void tdb_unset_attribute(struct tdb_context *tdb,
286 enum tdb_attribute_type type)
288 switch (type) {
289 case TDB_ATTRIBUTE_LOG:
290 tdb->log_fn = NULL;
291 break;
292 case TDB_ATTRIBUTE_HASH:
293 case TDB_ATTRIBUTE_SEED:
294 case TDB_ATTRIBUTE_OPENHOOK:
295 tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
296 "tdb_unset_attribute: cannot unset %s after opening",
297 type == TDB_ATTRIBUTE_HASH
298 ? "TDB_ATTRIBUTE_HASH"
299 : type == TDB_ATTRIBUTE_SEED
300 ? "TDB_ATTRIBUTE_SEED"
301 : "TDB_ATTRIBUTE_OPENHOOK");
302 break;
303 case TDB_ATTRIBUTE_STATS:
304 tdb_logerr(tdb, TDB_ERR_EINVAL,
305 TDB_LOG_USE_ERROR,
306 "tdb_unset_attribute:"
307 "cannot unset TDB_ATTRIBUTE_STATS");
308 break;
309 case TDB_ATTRIBUTE_FLOCK:
310 tdb->lock_fn = tdb_fcntl_lock;
311 tdb->unlock_fn = tdb_fcntl_unlock;
312 break;
313 default:
314 tdb_logerr(tdb, TDB_ERR_EINVAL,
315 TDB_LOG_USE_ERROR,
316 "tdb_unset_attribute: unknown attribute type %u",
317 type);
321 struct tdb_context *tdb_open(const char *name, int tdb_flags,
322 int open_flags, mode_t mode,
323 union tdb_attribute *attr)
325 struct tdb_context *tdb;
326 struct stat st;
327 int saved_errno = 0;
328 uint64_t hash_test;
329 unsigned v;
330 ssize_t rlen;
331 struct tdb_header hdr;
332 struct tdb_attribute_seed *seed = NULL;
333 struct tdb_attribute_openhook *openhook = NULL;
334 tdb_bool_err berr;
335 enum TDB_ERROR ecode;
336 int openlock;
338 tdb = malloc(sizeof(*tdb) + (name ? strlen(name) + 1 : 0));
339 if (!tdb) {
340 /* Can't log this */
341 errno = ENOMEM;
342 return NULL;
344 /* Set name immediately for logging functions. */
345 if (name) {
346 tdb->name = strcpy((char *)(tdb + 1), name);
347 } else {
348 tdb->name = NULL;
350 tdb->direct_access = 0;
351 tdb->flags = tdb_flags;
352 tdb->log_fn = NULL;
353 tdb->transaction = NULL;
354 tdb->access = NULL;
355 tdb->last_error = TDB_SUCCESS;
356 tdb->file = NULL;
357 tdb->lock_fn = tdb_fcntl_lock;
358 tdb->unlock_fn = tdb_fcntl_unlock;
359 tdb->hash_fn = jenkins_hash;
360 memset(&tdb->stats, 0, sizeof(tdb->stats));
361 tdb->stats.base.attr = TDB_ATTRIBUTE_STATS;
362 tdb->stats.size = sizeof(tdb->stats);
363 tdb_io_init(tdb);
365 while (attr) {
366 switch (attr->base.attr) {
367 case TDB_ATTRIBUTE_HASH:
368 tdb->hash_fn = attr->hash.fn;
369 tdb->hash_data = attr->hash.data;
370 break;
371 case TDB_ATTRIBUTE_SEED:
372 seed = &attr->seed;
373 break;
374 case TDB_ATTRIBUTE_OPENHOOK:
375 openhook = &attr->openhook;
376 break;
377 default:
378 /* These are set as normal. */
379 ecode = tdb_set_attribute(tdb, attr);
380 if (ecode != TDB_SUCCESS)
381 goto fail;
383 attr = attr->base.next;
386 if (tdb_flags & ~(TDB_INTERNAL | TDB_NOLOCK | TDB_NOMMAP | TDB_CONVERT
387 | TDB_NOSYNC | TDB_SEQNUM | TDB_ALLOW_NESTING)) {
388 ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
389 "tdb_open: unknown flags %u", tdb_flags);
390 goto fail;
393 if ((open_flags & O_ACCMODE) == O_WRONLY) {
394 ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
395 "tdb_open: can't open tdb %s write-only",
396 name);
397 goto fail;
400 if ((open_flags & O_ACCMODE) == O_RDONLY) {
401 tdb->read_only = true;
402 tdb->mmap_flags = PROT_READ;
403 openlock = F_RDLCK;
404 } else {
405 tdb->read_only = false;
406 tdb->mmap_flags = PROT_READ | PROT_WRITE;
407 openlock = F_WRLCK;
410 /* internal databases don't need any of the rest. */
411 if (tdb->flags & TDB_INTERNAL) {
412 tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
413 ecode = tdb_new_file(tdb);
414 if (ecode != TDB_SUCCESS) {
415 goto fail;
417 tdb->file->fd = -1;
418 ecode = tdb_new_database(tdb, seed, &hdr);
419 if (ecode != TDB_SUCCESS) {
420 goto fail;
422 tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
423 tdb->hash_seed = hdr.hash_seed;
424 tdb_ftable_init(tdb);
425 return tdb;
428 if (stat(name, &st) != -1)
429 tdb->file = find_file(st.st_dev, st.st_ino);
431 if (!tdb->file) {
432 int fd;
434 if ((fd = open(name, open_flags, mode)) == -1) {
435 /* errno set by open(2) */
436 saved_errno = errno;
437 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
438 "tdb_open: could not open file %s: %s",
439 name, strerror(errno));
440 goto fail_errno;
443 /* on exec, don't inherit the fd */
444 v = fcntl(fd, F_GETFD, 0);
445 fcntl(fd, F_SETFD, v | FD_CLOEXEC);
447 if (fstat(fd, &st) == -1) {
448 saved_errno = errno;
449 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
450 "tdb_open: could not stat open %s: %s",
451 name, strerror(errno));
452 close(fd);
453 goto fail_errno;
456 ecode = tdb_new_file(tdb);
457 if (ecode != TDB_SUCCESS) {
458 close(fd);
459 goto fail;
462 tdb->file->next = files;
463 tdb->file->fd = fd;
464 tdb->file->device = st.st_dev;
465 tdb->file->inode = st.st_ino;
466 tdb->file->map_ptr = NULL;
467 tdb->file->map_size = sizeof(struct tdb_header);
470 /* ensure there is only one process initialising at once */
471 ecode = tdb_lock_open(tdb, openlock, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK);
472 if (ecode != TDB_SUCCESS) {
473 saved_errno = errno;
474 goto fail_errno;
477 /* call their open hook if they gave us one. */
478 if (openhook) {
479 ecode = openhook->fn(tdb->file->fd, openhook->data);
480 if (ecode != TDB_SUCCESS) {
481 tdb_logerr(tdb, ecode, TDB_LOG_ERROR,
482 "tdb_open: open hook failed");
483 goto fail;
485 open_flags |= O_CREAT;
488 /* If they used O_TRUNC, read will return 0. */
489 rlen = pread(tdb->file->fd, &hdr, sizeof(hdr), 0);
490 if (rlen == 0 && (open_flags & O_CREAT)) {
491 ecode = tdb_new_database(tdb, seed, &hdr);
492 if (ecode != TDB_SUCCESS) {
493 goto fail;
495 } else if (rlen < 0) {
496 ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
497 "tdb_open: error %s reading %s",
498 strerror(errno), name);
499 goto fail;
500 } else if (rlen < sizeof(hdr)
501 || strcmp(hdr.magic_food, TDB_MAGIC_FOOD) != 0) {
502 ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
503 "tdb_open: %s is not a tdb file", name);
504 goto fail;
507 if (hdr.version != TDB_VERSION) {
508 if (hdr.version == bswap_64(TDB_VERSION))
509 tdb->flags |= TDB_CONVERT;
510 else {
511 /* wrong version */
512 ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
513 "tdb_open:"
514 " %s is unknown version 0x%llx",
515 name, (long long)hdr.version);
516 goto fail;
520 tdb_convert(tdb, &hdr, sizeof(hdr));
521 tdb->hash_seed = hdr.hash_seed;
522 hash_test = TDB_HASH_MAGIC;
523 hash_test = tdb_hash(tdb, &hash_test, sizeof(hash_test));
524 if (hdr.hash_test != hash_test) {
525 /* wrong hash variant */
526 ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
527 "tdb_open:"
528 " %s uses a different hash function",
529 name);
530 goto fail;
533 /* Clear any features we don't understand. */
534 if ((open_flags & O_ACCMODE) != O_RDONLY) {
535 hdr.features_used &= TDB_FEATURE_MASK;
536 if (tdb_write_convert(tdb, offsetof(struct tdb_header,
537 features_used),
538 &hdr.features_used,
539 sizeof(hdr.features_used)) == -1)
540 goto fail;
543 tdb_unlock_open(tdb, openlock);
545 /* This make sure we have current map_size and mmap. */
546 tdb->methods->oob(tdb, tdb->file->map_size + 1, true);
548 /* Now it's fully formed, recover if necessary. */
549 berr = tdb_needs_recovery(tdb);
550 if (unlikely(berr != false)) {
551 if (berr < 0) {
552 ecode = berr;
553 goto fail;
555 ecode = tdb_lock_and_recover(tdb);
556 if (ecode != TDB_SUCCESS) {
557 goto fail;
561 ecode = tdb_ftable_init(tdb);
562 if (ecode != TDB_SUCCESS) {
563 goto fail;
566 /* Add to linked list if we're new. */
567 if (tdb->file->refcnt == 1)
568 files = tdb->file;
569 return tdb;
571 fail:
572 /* Map ecode to some logical errno. */
573 switch (ecode) {
574 case TDB_ERR_CORRUPT:
575 case TDB_ERR_IO:
576 saved_errno = EIO;
577 break;
578 case TDB_ERR_LOCK:
579 saved_errno = EWOULDBLOCK;
580 break;
581 case TDB_ERR_OOM:
582 saved_errno = ENOMEM;
583 break;
584 case TDB_ERR_EINVAL:
585 saved_errno = EINVAL;
586 break;
587 default:
588 saved_errno = EINVAL;
589 break;
592 fail_errno:
593 #ifdef TDB_TRACE
594 close(tdb->tracefd);
595 #endif
596 if (tdb->file) {
597 tdb_lock_cleanup(tdb);
598 if (--tdb->file->refcnt == 0) {
599 assert(tdb->file->num_lockrecs == 0);
600 if (tdb->file->map_ptr) {
601 if (tdb->flags & TDB_INTERNAL) {
602 free(tdb->file->map_ptr);
603 } else
604 tdb_munmap(tdb->file);
606 if (close(tdb->file->fd) != 0)
607 tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
608 "tdb_open: failed to close tdb fd"
609 " on error: %s", strerror(errno));
610 free(tdb->file->lockrecs);
611 free(tdb->file);
615 free(tdb);
616 errno = saved_errno;
617 return NULL;
620 int tdb_close(struct tdb_context *tdb)
622 int ret = 0;
624 tdb_trace(tdb, "tdb_close");
626 if (tdb->transaction) {
627 tdb_transaction_cancel(tdb);
630 if (tdb->file->map_ptr) {
631 if (tdb->flags & TDB_INTERNAL)
632 free(tdb->file->map_ptr);
633 else
634 tdb_munmap(tdb->file);
636 if (tdb->file) {
637 struct tdb_file **i;
639 tdb_lock_cleanup(tdb);
640 if (--tdb->file->refcnt == 0) {
641 ret = close(tdb->file->fd);
643 /* Remove from files list */
644 for (i = &files; *i; i = &(*i)->next) {
645 if (*i == tdb->file) {
646 *i = tdb->file->next;
647 break;
650 free(tdb->file->lockrecs);
651 free(tdb->file);
655 #ifdef TDB_TRACE
656 close(tdb->tracefd);
657 #endif
658 free(tdb);
660 return ret;