Factor out the code checking if a parent should override DELETE_ACCESS into a function.
[Samba/gebeck_regimport.git] / lib / tdb2 / tdb.c
blob6f38244352cd5665fbe3eb5286ea846e6dc7b246
1 /*
2 Trivial Database 2: fetch, store and misc routines.
3 Copyright (C) Rusty Russell 2010
5 This library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 3 of the License, or (at your option) any later version.
10 This library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 #include "private.h"
19 #ifndef _SAMBA_BUILD_
20 #include <ccan/asprintf/asprintf.h>
21 #include <stdarg.h>
22 #endif
24 static enum TDB_ERROR update_rec_hdr(struct tdb_context *tdb,
25 tdb_off_t off,
26 tdb_len_t keylen,
27 tdb_len_t datalen,
28 struct tdb_used_record *rec,
29 uint64_t h)
31 uint64_t dataroom = rec_data_length(rec) + rec_extra_padding(rec);
32 enum TDB_ERROR ecode;
34 ecode = set_header(tdb, rec, TDB_USED_MAGIC, keylen, datalen,
35 keylen + dataroom, h);
36 if (ecode == TDB_SUCCESS) {
37 ecode = tdb_write_convert(tdb, off, rec, sizeof(*rec));
39 return ecode;
42 static enum TDB_ERROR replace_data(struct tdb_context *tdb,
43 struct hash_info *h,
44 struct tdb_data key, struct tdb_data dbuf,
45 tdb_off_t old_off, tdb_len_t old_room,
46 bool growing)
48 tdb_off_t new_off;
49 enum TDB_ERROR ecode;
51 /* Allocate a new record. */
52 new_off = alloc(tdb, key.dsize, dbuf.dsize, h->h, TDB_USED_MAGIC,
53 growing);
54 if (TDB_OFF_IS_ERR(new_off)) {
55 return TDB_OFF_TO_ERR(new_off);
58 /* We didn't like the existing one: remove it. */
59 if (old_off) {
60 tdb->stats.frees++;
61 ecode = add_free_record(tdb, old_off,
62 sizeof(struct tdb_used_record)
63 + key.dsize + old_room,
64 TDB_LOCK_WAIT, true);
65 if (ecode == TDB_SUCCESS)
66 ecode = replace_in_hash(tdb, h, new_off);
67 } else {
68 ecode = add_to_hash(tdb, h, new_off);
70 if (ecode != TDB_SUCCESS) {
71 return ecode;
74 new_off += sizeof(struct tdb_used_record);
75 ecode = tdb->tdb2.io->twrite(tdb, new_off, key.dptr, key.dsize);
76 if (ecode != TDB_SUCCESS) {
77 return ecode;
80 new_off += key.dsize;
81 ecode = tdb->tdb2.io->twrite(tdb, new_off, dbuf.dptr, dbuf.dsize);
82 if (ecode != TDB_SUCCESS) {
83 return ecode;
86 if (tdb->flags & TDB_SEQNUM)
87 tdb_inc_seqnum(tdb);
89 return TDB_SUCCESS;
92 static enum TDB_ERROR update_data(struct tdb_context *tdb,
93 tdb_off_t off,
94 struct tdb_data dbuf,
95 tdb_len_t extra)
97 enum TDB_ERROR ecode;
99 ecode = tdb->tdb2.io->twrite(tdb, off, dbuf.dptr, dbuf.dsize);
100 if (ecode == TDB_SUCCESS && extra) {
101 /* Put a zero in; future versions may append other data. */
102 ecode = tdb->tdb2.io->twrite(tdb, off + dbuf.dsize, "", 1);
104 if (tdb->flags & TDB_SEQNUM)
105 tdb_inc_seqnum(tdb);
107 return ecode;
110 enum TDB_ERROR tdb_store(struct tdb_context *tdb,
111 struct tdb_data key, struct tdb_data dbuf, int flag)
113 struct hash_info h;
114 tdb_off_t off;
115 tdb_len_t old_room = 0;
116 struct tdb_used_record rec;
117 enum TDB_ERROR ecode;
119 if (tdb->flags & TDB_VERSION1) {
120 if (tdb1_store(tdb, key, dbuf, flag) == -1)
121 return tdb->last_error;
122 return TDB_SUCCESS;
125 off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
126 if (TDB_OFF_IS_ERR(off)) {
127 return tdb->last_error = TDB_OFF_TO_ERR(off);
130 /* Now we have lock on this hash bucket. */
131 if (flag == TDB_INSERT) {
132 if (off) {
133 ecode = TDB_ERR_EXISTS;
134 goto out;
136 } else {
137 if (off) {
138 old_room = rec_data_length(&rec)
139 + rec_extra_padding(&rec);
140 if (old_room >= dbuf.dsize) {
141 /* Can modify in-place. Easy! */
142 ecode = update_rec_hdr(tdb, off,
143 key.dsize, dbuf.dsize,
144 &rec, h.h);
145 if (ecode != TDB_SUCCESS) {
146 goto out;
148 ecode = update_data(tdb,
149 off + sizeof(rec)
150 + key.dsize, dbuf,
151 old_room - dbuf.dsize);
152 if (ecode != TDB_SUCCESS) {
153 goto out;
155 tdb_unlock_hashes(tdb, h.hlock_start,
156 h.hlock_range, F_WRLCK);
157 return tdb->last_error = TDB_SUCCESS;
159 } else {
160 if (flag == TDB_MODIFY) {
161 /* if the record doesn't exist and we
162 are in TDB_MODIFY mode then we should fail
163 the store */
164 ecode = TDB_ERR_NOEXIST;
165 goto out;
170 /* If we didn't use the old record, this implies we're growing. */
171 ecode = replace_data(tdb, &h, key, dbuf, off, old_room, off);
172 out:
173 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
174 return tdb->last_error = ecode;
177 enum TDB_ERROR tdb_append(struct tdb_context *tdb,
178 struct tdb_data key, struct tdb_data dbuf)
180 struct hash_info h;
181 tdb_off_t off;
182 struct tdb_used_record rec;
183 tdb_len_t old_room = 0, old_dlen;
184 unsigned char *newdata;
185 struct tdb_data new_dbuf;
186 enum TDB_ERROR ecode;
188 if (tdb->flags & TDB_VERSION1) {
189 if (tdb1_append(tdb, key, dbuf) == -1)
190 return tdb->last_error;
191 return TDB_SUCCESS;
194 off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
195 if (TDB_OFF_IS_ERR(off)) {
196 return tdb->last_error = TDB_OFF_TO_ERR(off);
199 if (off) {
200 old_dlen = rec_data_length(&rec);
201 old_room = old_dlen + rec_extra_padding(&rec);
203 /* Fast path: can append in place. */
204 if (rec_extra_padding(&rec) >= dbuf.dsize) {
205 ecode = update_rec_hdr(tdb, off, key.dsize,
206 old_dlen + dbuf.dsize, &rec,
207 h.h);
208 if (ecode != TDB_SUCCESS) {
209 goto out;
212 off += sizeof(rec) + key.dsize + old_dlen;
213 ecode = update_data(tdb, off, dbuf,
214 rec_extra_padding(&rec));
215 goto out;
218 /* Slow path. */
219 newdata = malloc(key.dsize + old_dlen + dbuf.dsize);
220 if (!newdata) {
221 ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
222 "tdb_append:"
223 " failed to allocate %zu bytes",
224 (size_t)(key.dsize + old_dlen
225 + dbuf.dsize));
226 goto out;
228 ecode = tdb->tdb2.io->tread(tdb, off + sizeof(rec) + key.dsize,
229 newdata, old_dlen);
230 if (ecode != TDB_SUCCESS) {
231 goto out_free_newdata;
233 memcpy(newdata + old_dlen, dbuf.dptr, dbuf.dsize);
234 new_dbuf.dptr = newdata;
235 new_dbuf.dsize = old_dlen + dbuf.dsize;
236 } else {
237 newdata = NULL;
238 new_dbuf = dbuf;
241 /* If they're using tdb_append(), it implies they're growing record. */
242 ecode = replace_data(tdb, &h, key, new_dbuf, off, old_room, true);
244 out_free_newdata:
245 free(newdata);
246 out:
247 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
248 return tdb->last_error = ecode;
251 enum TDB_ERROR tdb_fetch(struct tdb_context *tdb, struct tdb_data key,
252 struct tdb_data *data)
254 tdb_off_t off;
255 struct tdb_used_record rec;
256 struct hash_info h;
257 enum TDB_ERROR ecode;
259 if (tdb->flags & TDB_VERSION1)
260 return tdb1_fetch(tdb, key, data);
262 off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
263 if (TDB_OFF_IS_ERR(off)) {
264 return tdb->last_error = TDB_OFF_TO_ERR(off);
267 if (!off) {
268 ecode = TDB_ERR_NOEXIST;
269 } else {
270 data->dsize = rec_data_length(&rec);
271 data->dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize,
272 data->dsize);
273 if (TDB_PTR_IS_ERR(data->dptr)) {
274 ecode = TDB_PTR_ERR(data->dptr);
275 } else
276 ecode = TDB_SUCCESS;
279 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
280 return tdb->last_error = ecode;
283 bool tdb_exists(struct tdb_context *tdb, TDB_DATA key)
285 tdb_off_t off;
286 struct tdb_used_record rec;
287 struct hash_info h;
289 if (tdb->flags & TDB_VERSION1) {
290 return tdb1_exists(tdb, key);
293 off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
294 if (TDB_OFF_IS_ERR(off)) {
295 tdb->last_error = TDB_OFF_TO_ERR(off);
296 return false;
298 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
300 tdb->last_error = TDB_SUCCESS;
301 return off ? true : false;
304 enum TDB_ERROR tdb_delete(struct tdb_context *tdb, struct tdb_data key)
306 tdb_off_t off;
307 struct tdb_used_record rec;
308 struct hash_info h;
309 enum TDB_ERROR ecode;
311 if (tdb->flags & TDB_VERSION1) {
312 if (tdb1_delete(tdb, key) == -1)
313 return tdb->last_error;
314 return TDB_SUCCESS;
317 off = find_and_lock(tdb, key, F_WRLCK, &h, &rec, NULL);
318 if (TDB_OFF_IS_ERR(off)) {
319 return tdb->last_error = TDB_OFF_TO_ERR(off);
322 if (!off) {
323 ecode = TDB_ERR_NOEXIST;
324 goto unlock;
327 ecode = delete_from_hash(tdb, &h);
328 if (ecode != TDB_SUCCESS) {
329 goto unlock;
332 /* Free the deleted entry. */
333 tdb->stats.frees++;
334 ecode = add_free_record(tdb, off,
335 sizeof(struct tdb_used_record)
336 + rec_key_length(&rec)
337 + rec_data_length(&rec)
338 + rec_extra_padding(&rec),
339 TDB_LOCK_WAIT, true);
341 if (tdb->flags & TDB_SEQNUM)
342 tdb_inc_seqnum(tdb);
344 unlock:
345 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_WRLCK);
346 return tdb->last_error = ecode;
349 unsigned int tdb_get_flags(struct tdb_context *tdb)
351 return tdb->flags;
354 static bool inside_transaction(const struct tdb_context *tdb)
356 if (tdb->flags & TDB_VERSION1)
357 return tdb->tdb1.transaction != NULL;
358 else
359 return tdb->tdb2.transaction != NULL;
362 static bool readonly_changable(struct tdb_context *tdb, const char *caller)
364 if (inside_transaction(tdb)) {
365 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
366 TDB_LOG_USE_ERROR,
367 "%s: can't change"
368 " TDB_RDONLY inside transaction",
369 caller);
370 return false;
372 return true;
375 void tdb_add_flag(struct tdb_context *tdb, unsigned flag)
377 if (tdb->flags & TDB_INTERNAL) {
378 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
379 TDB_LOG_USE_ERROR,
380 "tdb_add_flag: internal db");
381 return;
383 switch (flag) {
384 case TDB_NOLOCK:
385 tdb->flags |= TDB_NOLOCK;
386 break;
387 case TDB_NOMMAP:
388 tdb->flags |= TDB_NOMMAP;
389 tdb_munmap(tdb->file);
390 break;
391 case TDB_NOSYNC:
392 tdb->flags |= TDB_NOSYNC;
393 break;
394 case TDB_SEQNUM:
395 tdb->flags |= TDB_SEQNUM;
396 break;
397 case TDB_ALLOW_NESTING:
398 tdb->flags |= TDB_ALLOW_NESTING;
399 break;
400 case TDB_RDONLY:
401 if (readonly_changable(tdb, "tdb_add_flag"))
402 tdb->flags |= TDB_RDONLY;
403 break;
404 default:
405 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
406 TDB_LOG_USE_ERROR,
407 "tdb_add_flag: Unknown flag %u",
408 flag);
412 void tdb_remove_flag(struct tdb_context *tdb, unsigned flag)
414 if (tdb->flags & TDB_INTERNAL) {
415 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
416 TDB_LOG_USE_ERROR,
417 "tdb_remove_flag: internal db");
418 return;
420 switch (flag) {
421 case TDB_NOLOCK:
422 tdb->flags &= ~TDB_NOLOCK;
423 break;
424 case TDB_NOMMAP:
425 tdb->flags &= ~TDB_NOMMAP;
426 tdb_mmap(tdb);
427 break;
428 case TDB_NOSYNC:
429 tdb->flags &= ~TDB_NOSYNC;
430 break;
431 case TDB_SEQNUM:
432 tdb->flags &= ~TDB_SEQNUM;
433 break;
434 case TDB_ALLOW_NESTING:
435 tdb->flags &= ~TDB_ALLOW_NESTING;
436 break;
437 case TDB_RDONLY:
438 if ((tdb->open_flags & O_ACCMODE) == O_RDONLY) {
439 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
440 TDB_LOG_USE_ERROR,
441 "tdb_remove_flag: can't"
442 " remove TDB_RDONLY on tdb"
443 " opened with O_RDONLY");
444 break;
446 if (readonly_changable(tdb, "tdb_remove_flag"))
447 tdb->flags &= ~TDB_RDONLY;
448 break;
449 default:
450 tdb->last_error = tdb_logerr(tdb, TDB_ERR_EINVAL,
451 TDB_LOG_USE_ERROR,
452 "tdb_remove_flag: Unknown flag %u",
453 flag);
457 const char *tdb_errorstr(enum TDB_ERROR ecode)
459 /* Gcc warns if you miss a case in the switch, so use that. */
460 switch (TDB_ERR_TO_OFF(ecode)) {
461 case TDB_ERR_TO_OFF(TDB_SUCCESS): return "Success";
462 case TDB_ERR_TO_OFF(TDB_ERR_CORRUPT): return "Corrupt database";
463 case TDB_ERR_TO_OFF(TDB_ERR_IO): return "IO Error";
464 case TDB_ERR_TO_OFF(TDB_ERR_LOCK): return "Locking error";
465 case TDB_ERR_TO_OFF(TDB_ERR_OOM): return "Out of memory";
466 case TDB_ERR_TO_OFF(TDB_ERR_EXISTS): return "Record exists";
467 case TDB_ERR_TO_OFF(TDB_ERR_EINVAL): return "Invalid parameter";
468 case TDB_ERR_TO_OFF(TDB_ERR_NOEXIST): return "Record does not exist";
469 case TDB_ERR_TO_OFF(TDB_ERR_RDONLY): return "write not permitted";
471 return "Invalid error code";
474 enum TDB_ERROR tdb_error(struct tdb_context *tdb)
476 return tdb->last_error;
479 enum TDB_ERROR COLD tdb_logerr(struct tdb_context *tdb,
480 enum TDB_ERROR ecode,
481 enum tdb_log_level level,
482 const char *fmt, ...)
484 char *message;
485 va_list ap;
486 size_t len;
487 /* tdb_open paths care about errno, so save it. */
488 int saved_errno = errno;
490 if (!tdb->log_fn)
491 return ecode;
493 va_start(ap, fmt);
494 len = vasprintf(&message, fmt, ap);
495 va_end(ap);
497 if (len < 0) {
498 tdb->log_fn(tdb, TDB_LOG_ERROR, TDB_ERR_OOM,
499 "out of memory formatting message:", tdb->log_data);
500 tdb->log_fn(tdb, level, ecode, fmt, tdb->log_data);
501 } else {
502 tdb->log_fn(tdb, level, ecode, message, tdb->log_data);
503 free(message);
505 errno = saved_errno;
506 return ecode;
509 enum TDB_ERROR tdb_parse_record_(struct tdb_context *tdb,
510 TDB_DATA key,
511 enum TDB_ERROR (*parse)(TDB_DATA k,
512 TDB_DATA d,
513 void *data),
514 void *data)
516 tdb_off_t off;
517 struct tdb_used_record rec;
518 struct hash_info h;
519 enum TDB_ERROR ecode;
521 if (tdb->flags & TDB_VERSION1) {
522 return tdb->last_error = tdb1_parse_record(tdb, key, parse,
523 data);
526 off = find_and_lock(tdb, key, F_RDLCK, &h, &rec, NULL);
527 if (TDB_OFF_IS_ERR(off)) {
528 return tdb->last_error = TDB_OFF_TO_ERR(off);
531 if (!off) {
532 ecode = TDB_ERR_NOEXIST;
533 } else {
534 const void *dptr;
535 dptr = tdb_access_read(tdb, off + sizeof(rec) + key.dsize,
536 rec_data_length(&rec), false);
537 if (TDB_PTR_IS_ERR(dptr)) {
538 ecode = TDB_PTR_ERR(dptr);
539 } else {
540 TDB_DATA d = tdb_mkdata(dptr, rec_data_length(&rec));
542 ecode = parse(key, d, data);
543 tdb_access_release(tdb, dptr);
547 tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);
548 return tdb->last_error = ecode;
551 const char *tdb_name(const struct tdb_context *tdb)
553 return tdb->name;
556 int64_t tdb_get_seqnum(struct tdb_context *tdb)
558 tdb_off_t off;
560 if (tdb->flags & TDB_VERSION1) {
561 tdb1_off_t val;
562 tdb->last_error = TDB_SUCCESS;
563 val = tdb1_get_seqnum(tdb);
565 if (tdb->last_error != TDB_SUCCESS)
566 return TDB_ERR_TO_OFF(tdb->last_error);
567 else
568 return val;
571 off = tdb_read_off(tdb, offsetof(struct tdb_header, seqnum));
572 if (TDB_OFF_IS_ERR(off))
573 tdb->last_error = TDB_OFF_TO_ERR(off);
574 else
575 tdb->last_error = TDB_SUCCESS;
576 return off;
580 int tdb_fd(const struct tdb_context *tdb)
582 return tdb->file->fd;
585 struct traverse_state {
586 enum TDB_ERROR error;
587 struct tdb_context *dest_db;
591 traverse function for repacking
593 static int repack_traverse(struct tdb_context *tdb, TDB_DATA key, TDB_DATA data,
594 struct traverse_state *state)
596 state->error = tdb_store(state->dest_db, key, data, TDB_INSERT);
597 if (state->error != TDB_SUCCESS) {
598 return -1;
600 return 0;
603 enum TDB_ERROR tdb_repack(struct tdb_context *tdb)
605 struct tdb_context *tmp_db;
606 struct traverse_state state;
608 state.error = tdb_transaction_start(tdb);
609 if (state.error != TDB_SUCCESS) {
610 return state.error;
613 tmp_db = tdb_open("tmpdb", TDB_INTERNAL, O_RDWR|O_CREAT, 0, NULL);
614 if (tmp_db == NULL) {
615 state.error = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
616 __location__
617 " Failed to create tmp_db");
618 tdb_transaction_cancel(tdb);
619 return tdb->last_error = state.error;
622 state.dest_db = tmp_db;
623 if (tdb_traverse(tdb, repack_traverse, &state) < 0) {
624 goto fail;
627 state.error = tdb_wipe_all(tdb);
628 if (state.error != TDB_SUCCESS) {
629 goto fail;
632 state.dest_db = tdb;
633 if (tdb_traverse(tmp_db, repack_traverse, &state) < 0) {
634 goto fail;
637 tdb_close(tmp_db);
638 return tdb_transaction_commit(tdb);
640 fail:
641 tdb_transaction_cancel(tdb);
642 tdb_close(tmp_db);
643 return state.error;