2 * Unix SMB/CIFS implementation.
4 * A general tdb content validation mechanism
6 * Copyright (C) Michael Adam 2007
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 3 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
22 #include "tdb_validate.h"
26 * internal validation function, executed by the child.
28 static int tdb_validate_child(struct tdb_context
*tdb
,
29 tdb_validate_data_func validate_fn
)
33 struct tdb_validation_status v_status
;
35 v_status
.tdb_error
= False
;
36 v_status
.bad_freelist
= False
;
37 v_status
.bad_entry
= False
;
38 v_status
.unknown_key
= False
;
39 v_status
.success
= True
;
42 v_status
.tdb_error
= True
;
43 v_status
.success
= False
;
48 * we can simplify this by passing a check function,
49 * but I don't want to change all the callers...
51 ret
= tdb_check(tdb
, NULL
, NULL
);
53 v_status
.tdb_error
= True
;
54 v_status
.success
= False
;
58 /* Check if the tdb's freelist is good. */
59 if (tdb_validate_freelist(tdb
, &num_entries
) == -1) {
60 v_status
.bad_freelist
= True
;
61 v_status
.success
= False
;
65 DEBUG(10,("tdb_validate_child: tdb %s freelist has %d entries\n",
66 tdb_name(tdb
), num_entries
));
68 /* Now traverse the tdb to validate it. */
69 num_entries
= tdb_traverse(tdb
, validate_fn
, (void *)&v_status
);
70 if (!v_status
.success
) {
72 } else if (num_entries
== -1) {
73 v_status
.tdb_error
= True
;
74 v_status
.success
= False
;
78 DEBUG(10,("tdb_validate_child: tdb %s is good with %d entries\n",
79 tdb_name(tdb
), num_entries
));
80 ret
= 0; /* Cache is good. */
83 DEBUG(10, ("tdb_validate_child: summary of validation status:\n"));
84 DEBUGADD(10,(" * tdb error: %s\n", v_status
.tdb_error
? "yes" : "no"));
85 DEBUGADD(10,(" * bad freelist: %s\n",v_status
.bad_freelist
?"yes":"no"));
86 DEBUGADD(10,(" * bad entry: %s\n", v_status
.bad_entry
? "yes" : "no"));
87 DEBUGADD(10,(" * unknown key: %s\n", v_status
.unknown_key
?"yes":"no"));
88 DEBUGADD(10,(" => overall success: %s\n", v_status
.success
?"yes":"no"));
94 * tdb validation function.
95 * returns 0 if tdb is ok, != 0 if it isn't.
96 * this function expects an opened tdb.
98 int tdb_validate(struct tdb_context
*tdb
, tdb_validate_data_func validate_fn
)
100 pid_t child_pid
= -1;
101 int child_status
= 0;
106 DEBUG(1, ("Error: tdb_validate called with tdb == NULL\n"));
110 DEBUG(5, ("tdb_validate called for tdb '%s'\n", tdb_name(tdb
)));
112 /* fork and let the child do the validation.
113 * benefit: no need to twist signal handlers and panic functions.
114 * just let the child panic. we catch the signal. */
116 DEBUG(10, ("tdb_validate: forking to let child do validation.\n"));
117 child_pid
= sys_fork();
118 if (child_pid
== 0) {
120 DEBUG(10, ("tdb_validate (validation child): created\n"));
121 DEBUG(10, ("tdb_validate (validation child): "
122 "calling tdb_validate_child\n"));
123 exit(tdb_validate_child(tdb
, validate_fn
));
125 else if (child_pid
< 0) {
126 DEBUG(1, ("tdb_validate: fork for validation failed.\n"));
132 DEBUG(10, ("tdb_validate: fork succeeded, child PID = %u\n",
133 (unsigned int)child_pid
));
135 DEBUG(10, ("tdb_validate: waiting for child to finish...\n"));
136 while ((wait_pid
= sys_waitpid(child_pid
, &child_status
, 0)) < 0) {
137 if (errno
== EINTR
) {
138 DEBUG(10, ("tdb_validate: got signal during waitpid, "
143 DEBUG(1, ("tdb_validate: waitpid failed with error '%s'.\n",
147 if (wait_pid
!= child_pid
) {
148 DEBUG(1, ("tdb_validate: waitpid returned pid %d, "
149 "but %u was expected\n", wait_pid
, (unsigned int)child_pid
));
153 DEBUG(10, ("tdb_validate: validating child returned.\n"));
154 if (WIFEXITED(child_status
)) {
155 DEBUG(10, ("tdb_validate: child exited, code %d.\n",
156 WEXITSTATUS(child_status
)));
157 ret
= WEXITSTATUS(child_status
);
159 if (WIFSIGNALED(child_status
)) {
160 DEBUG(10, ("tdb_validate: child terminated by signal %d\n",
161 WTERMSIG(child_status
)));
163 if (WCOREDUMP(child_status
)) {
164 DEBUGADD(10, ("core dumped\n"));
167 ret
= WTERMSIG(child_status
);
169 if (WIFSTOPPED(child_status
)) {
170 DEBUG(10, ("tdb_validate: child was stopped by signal %d\n",
171 WSTOPSIG(child_status
)));
172 ret
= WSTOPSIG(child_status
);
176 DEBUG(5, ("tdb_validate returning code '%d' for tdb '%s'\n", ret
,
183 * tdb validation function.
184 * returns 0 if tdb is ok, != 0 if it isn't.
185 * this is a wrapper around the actual validation function that opens and closes
188 int tdb_validate_open(const char *tdb_path
, tdb_validate_data_func validate_fn
)
190 TDB_CONTEXT
*tdb
= NULL
;
193 DEBUG(5, ("tdb_validate_open called for tdb '%s'\n", tdb_path
));
195 tdb
= tdb_open_log(tdb_path
, 0, TDB_DEFAULT
, O_RDWR
, 0);
197 DEBUG(1, ("Error opening tdb %s\n", tdb_path
));
201 ret
= tdb_validate(tdb
, validate_fn
);
207 * tdb backup function and helpers for tdb_validate wrapper with backup
211 /* this structure eliminates the need for a global overall status for
212 * the traverse-copy */
213 struct tdb_copy_data
{
214 struct tdb_context
*dst
;
218 static int traverse_copy_fn(struct tdb_context
*tdb
, TDB_DATA key
,
219 TDB_DATA dbuf
, void *private_data
)
221 struct tdb_copy_data
*data
= (struct tdb_copy_data
*)private_data
;
223 if (tdb_store(data
->dst
, key
, dbuf
, TDB_INSERT
) != 0) {
224 DEBUG(4, ("Failed to insert into %s: %s\n", tdb_name(data
->dst
),
226 data
->success
= False
;
232 static int tdb_copy(struct tdb_context
*src
, struct tdb_context
*dst
)
234 struct tdb_copy_data data
;
240 count
= tdb_traverse(src
, traverse_copy_fn
, (void *)(&data
));
241 if ((count
< 0) || (data
.success
== False
)) {
247 static int tdb_verify_basic(struct tdb_context
*tdb
)
249 return tdb_traverse(tdb
, NULL
, NULL
);
252 /* this backup function is essentially taken from lib/tdb/tools/tdbbackup.tdb
254 static int tdb_backup(TALLOC_CTX
*ctx
, const char *src_path
,
255 const char *dst_path
, int hash_size
)
257 struct tdb_context
*src_tdb
= NULL
;
258 struct tdb_context
*dst_tdb
= NULL
;
259 char *tmp_path
= NULL
;
265 if (stat(src_path
, &st
) != 0) {
266 DEBUG(3, ("Could not stat '%s': %s\n", src_path
,
271 /* open old tdb RDWR - so we can lock it */
272 src_tdb
= tdb_open_log(src_path
, 0, TDB_DEFAULT
, O_RDWR
, 0);
273 if (src_tdb
== NULL
) {
274 DEBUG(3, ("Failed to open tdb '%s'\n", src_path
));
278 if (tdb_lockall(src_tdb
) != 0) {
279 DEBUG(3, ("Failed to lock tdb '%s'\n", src_path
));
283 tmp_path
= talloc_asprintf(ctx
, "%s%s", dst_path
, ".tmp");
285 DEBUG(3, ("talloc fail\n"));
290 dst_tdb
= tdb_open_log(tmp_path
,
291 hash_size
? hash_size
: tdb_hash_size(src_tdb
),
292 TDB_DEFAULT
, O_RDWR
| O_CREAT
| O_EXCL
,
294 if (dst_tdb
== NULL
) {
295 DEBUG(3, ("Error creating tdb '%s': %s\n", tmp_path
,
302 count1
= tdb_copy(src_tdb
, dst_tdb
);
304 DEBUG(3, ("Failed to copy tdb '%s': %s\n", src_path
,
310 /* reopen ro and do basic verification */
312 dst_tdb
= tdb_open_log(tmp_path
, 0, TDB_DEFAULT
, O_RDONLY
, 0);
314 DEBUG(3, ("Failed to reopen tdb '%s': %s\n", tmp_path
,
318 count2
= tdb_verify_basic(dst_tdb
);
319 if (count2
!= count1
) {
320 DEBUG(3, ("Failed to verify result of copying tdb '%s'.\n",
326 DEBUG(10, ("tdb_backup: successfully copied %d entries\n", count1
));
328 /* make sure the new tdb has reached stable storage
329 * then rename it to its destination */
330 fsync(tdb_fd(dst_tdb
));
333 if (rename(tmp_path
, dst_path
) != 0) {
334 DEBUG(3, ("Failed to rename '%s' to '%s': %s\n",
335 tmp_path
, dst_path
, strerror(errno
)));
343 if (src_tdb
!= NULL
) {
346 if (tmp_path
!= NULL
) {
348 TALLOC_FREE(tmp_path
);
350 if (saved_errno
!= 0) {
356 static int rename_file_with_suffix(TALLOC_CTX
*ctx
, const char *path
,
362 dst_path
= talloc_asprintf(ctx
, "%s%s", path
, suffix
);
363 if (dst_path
== NULL
) {
364 DEBUG(3, ("error out of memory\n"));
368 ret
= (rename(path
, dst_path
) != 0);
371 DEBUG(5, ("moved '%s' to '%s'\n", path
, dst_path
));
372 } else if (errno
== ENOENT
) {
373 DEBUG(3, ("file '%s' does not exist - so not moved\n", path
));
376 DEBUG(3, ("error renaming %s to %s: %s\n", path
, dst_path
,
380 TALLOC_FREE(dst_path
);
385 * do a backup of a tdb, moving the destination out of the way first
387 static int tdb_backup_with_rotate(TALLOC_CTX
*ctx
, const char *src_path
,
388 const char *dst_path
, int hash_size
,
389 const char *rotate_suffix
,
390 bool retry_norotate_if_nospc
,
391 bool rename_as_last_resort_if_nospc
)
395 rename_file_with_suffix(ctx
, dst_path
, rotate_suffix
);
397 ret
= tdb_backup(ctx
, src_path
, dst_path
, hash_size
);
400 DEBUG(10, ("backup of %s failed: %s\n", src_path
, strerror(errno
)));
402 if ((ret
!= 0) && (errno
== ENOSPC
) && retry_norotate_if_nospc
)
404 char *rotate_path
= talloc_asprintf(ctx
, "%s%s", dst_path
,
406 if (rotate_path
== NULL
) {
407 DEBUG(10, ("talloc fail\n"));
410 DEBUG(10, ("backup of %s failed due to lack of space\n",
412 DEBUGADD(10, ("trying to free some space by removing rotated "
413 "dst %s\n", rotate_path
));
414 if (unlink(rotate_path
) == -1) {
415 DEBUG(10, ("unlink of %s failed: %s\n", rotate_path
,
418 ret
= tdb_backup(ctx
, src_path
, dst_path
, hash_size
);
420 TALLOC_FREE(rotate_path
);
423 if ((ret
!= 0) && (errno
== ENOSPC
) && rename_as_last_resort_if_nospc
)
425 DEBUG(10, ("backup of %s failed due to lack of space\n",
427 DEBUGADD(10, ("using 'rename' as a last resort\n"));
428 ret
= rename(src_path
, dst_path
);
435 * validation function with backup handling:
437 * - calls tdb_validate
438 * - if the tdb is ok, create a backup "name.bak", possibly moving
439 * existing backup to name.bak.old,
440 * return 0 (success) even if the backup fails
441 * - if the tdb is corrupt:
442 * - move the tdb to "name.corrupt"
443 * - check if there is valid backup.
444 * if so, restore the backup.
445 * if restore is successful, return 0 (success),
446 * - otherwise return -1 (failure)
448 int tdb_validate_and_backup(const char *tdb_path
,
449 tdb_validate_data_func validate_fn
)
452 const char *backup_suffix
= ".bak";
453 const char *corrupt_suffix
= ".corrupt";
454 const char *rotate_suffix
= ".old";
455 char *tdb_path_backup
;
457 TALLOC_CTX
*ctx
= NULL
;
459 ctx
= talloc_new(NULL
);
461 DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
465 tdb_path_backup
= talloc_asprintf(ctx
, "%s%s", tdb_path
, backup_suffix
);
466 if (!tdb_path_backup
) {
467 DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
471 ret
= tdb_validate_open(tdb_path
, validate_fn
);
474 DEBUG(1, ("tdb '%s' is valid\n", tdb_path
));
475 ret
= tdb_backup_with_rotate(ctx
, tdb_path
, tdb_path_backup
, 0,
476 rotate_suffix
, True
, False
);
478 DEBUG(1, ("Error creating backup of tdb '%s'\n",
480 /* the actual validation was successful: */
483 DEBUG(1, ("Created backup '%s' of tdb '%s'\n",
484 tdb_path_backup
, tdb_path
));
487 DEBUG(1, ("tdb '%s' is invalid\n", tdb_path
));
489 ret
=stat(tdb_path_backup
, &st
);
491 DEBUG(5, ("Could not stat '%s': %s\n", tdb_path_backup
,
493 DEBUG(1, ("No backup found.\n"));
495 DEBUG(1, ("backup '%s' found.\n", tdb_path_backup
));
496 ret
= tdb_validate_open(tdb_path_backup
, validate_fn
);
498 DEBUG(1, ("Backup '%s' is invalid.\n",
504 int renamed
= rename_file_with_suffix(ctx
, tdb_path
,
507 DEBUG(1, ("Error moving tdb to '%s%s'\n",
508 tdb_path
, corrupt_suffix
));
510 DEBUG(1, ("Corrupt tdb stored as '%s%s'\n",
511 tdb_path
, corrupt_suffix
));
516 DEBUG(1, ("valid backup '%s' found\n", tdb_path_backup
));
517 ret
= tdb_backup_with_rotate(ctx
, tdb_path_backup
, tdb_path
, 0,
518 corrupt_suffix
, True
, True
);
520 DEBUG(1, ("Error restoring backup from '%s'\n",
523 DEBUG(1, ("Restored tdb backup from '%s'\n",