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/>.
23 #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;
47 /* Check if the tdb's freelist is good. */
48 if (tdb_validate_freelist(tdb, &num_entries) == -1) {
49 v_status.bad_freelist = True;
50 v_status.success = False;
54 DEBUG(10,("tdb_validate_child: tdb %s freelist has %d entries\n",
55 tdb_name(tdb), num_entries));
57 /* Now traverse the tdb to validate it. */
58 num_entries = tdb_traverse(tdb, validate_fn, (void *)&v_status);
59 if (!v_status.success) {
61 } else if (num_entries == -1) {
62 v_status.tdb_error = True;
63 v_status.success = False;
67 DEBUG(10,("tdb_validate_child: tdb %s is good with %d entries\n",
68 tdb_name(tdb), num_entries));
69 ret = 0; /* Cache is good. */
72 DEBUG(10, ("tdb_validate_child: summary of validation status:\n"));
73 DEBUGADD(10,(" * tdb error: %s\n", v_status.tdb_error ? "yes" : "no"));
74 DEBUGADD(10,(" * bad freelist: %s\n",v_status.bad_freelist?"yes":"no"));
75 DEBUGADD(10,(" * bad entry: %s\n", v_status.bad_entry ? "yes" : "no"));
76 DEBUGADD(10,(" * unknown key: %s\n", v_status.unknown_key?"yes":"no"));
77 DEBUGADD(10,(" => overall success: %s\n", v_status.success?"yes":"no"));
83 * tdb validation function.
84 * returns 0 if tdb is ok, != 0 if it isn't.
85 * this function expects an opened tdb.
87 int tdb_validate(struct tdb_context *tdb, tdb_validate_data_func validate_fn)
95 DEBUG(1, ("Error: tdb_validate called with tdb == NULL\n"));
99 DEBUG(5, ("tdb_validate called for tdb '%s'\n", tdb_name(tdb)));
101 /* fork and let the child do the validation.
102 * benefit: no need to twist signal handlers and panic functions.
103 * just let the child panic. we catch the signal. */
105 DEBUG(10, ("tdb_validate: forking to let child do validation.\n"));
106 child_pid = sys_fork();
107 if (child_pid == 0) {
109 DEBUG(10, ("tdb_validate (validation child): created\n"));
110 DEBUG(10, ("tdb_validate (validation child): "
111 "calling tdb_validate_child\n"));
112 exit(tdb_validate_child(tdb, validate_fn));
114 else if (child_pid < 0) {
115 DEBUG(1, ("tdb_validate: fork for validation failed.\n"));
121 DEBUG(10, ("tdb_validate: fork succeeded, child PID = %d\n",child_pid));
123 DEBUG(10, ("tdb_validate: waiting for child to finish...\n"));
124 while ((wait_pid = sys_waitpid(child_pid, &child_status, 0)) < 0) {
125 if (errno == EINTR) {
126 DEBUG(10, ("tdb_validate: got signal during waitpid, "
131 DEBUG(1, ("tdb_validate: waitpid failed with error '%s'.\n",
135 if (wait_pid != child_pid) {
136 DEBUG(1, ("tdb_validate: waitpid returned pid %d, "
137 "but %d was expected\n", wait_pid, child_pid));
141 DEBUG(10, ("tdb_validate: validating child returned.\n"));
142 if (WIFEXITED(child_status)) {
143 DEBUG(10, ("tdb_validate: child exited, code %d.\n",
144 WEXITSTATUS(child_status)));
145 ret = WEXITSTATUS(child_status);
147 if (WIFSIGNALED(child_status)) {
148 DEBUG(10, ("tdb_validate: child terminated by signal %d\n",
149 WTERMSIG(child_status)));
151 if (WCOREDUMP(child_status)) {
152 DEBUGADD(10, ("core dumped\n"));
155 ret = WTERMSIG(child_status);
157 if (WIFSTOPPED(child_status)) {
158 DEBUG(10, ("tdb_validate: child was stopped by signal %d\n",
159 WSTOPSIG(child_status)));
160 ret = WSTOPSIG(child_status);
164 DEBUG(5, ("tdb_validate returning code '%d' for tdb '%s'\n", ret,
171 * tdb validation function.
172 * returns 0 if tdb is ok, != 0 if it isn't.
173 * this is a wrapper around the actual validation function that opens and closes
176 int tdb_validate_open(const char *tdb_path, tdb_validate_data_func validate_fn)
178 TDB_CONTEXT *tdb = NULL;
181 DEBUG(5, ("tdb_validate_open called for tdb '%s'\n", tdb_path));
183 tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDONLY, 0);
185 DEBUG(1, ("Error opening tdb %s\n", tdb_path));
189 ret = tdb_validate(tdb, validate_fn);
195 * tdb backup function and helpers for tdb_validate wrapper with backup
199 /* this structure eliminates the need for a global overall status for
200 * the traverse-copy */
201 struct tdb_copy_data {
202 struct tdb_context *dst;
206 static int traverse_copy_fn(struct tdb_context *tdb, TDB_DATA key,
207 TDB_DATA dbuf, void *private_data)
209 struct tdb_copy_data *data = (struct tdb_copy_data *)private_data;
211 if (tdb_store(data->dst, key, dbuf, TDB_INSERT) != 0) {
212 DEBUG(4, ("Failed to insert into %s: %s\n", tdb_name(data->dst),
214 data->success = False;
220 static int tdb_copy(struct tdb_context *src, struct tdb_context *dst)
222 struct tdb_copy_data data;
228 count = tdb_traverse(src, traverse_copy_fn, (void *)(&data));
229 if ((count < 0) || (data.success == False)) {
235 static int tdb_verify_basic(struct tdb_context *tdb)
237 return tdb_traverse(tdb, NULL, NULL);
240 /* this backup function is essentially taken from lib/tdb/tools/tdbbackup.tdb
242 static int tdb_backup(TALLOC_CTX *ctx, const char *src_path,
243 const char *dst_path, int hash_size)
245 struct tdb_context *src_tdb = NULL;
246 struct tdb_context *dst_tdb = NULL;
247 char *tmp_path = NULL;
253 if (stat(src_path, &st) != 0) {
254 DEBUG(3, ("Could not stat '%s': %s\n", src_path,
259 /* open old tdb RDWR - so we can lock it */
260 src_tdb = tdb_open_log(src_path, 0, TDB_DEFAULT, O_RDWR, 0);
261 if (src_tdb == NULL) {
262 DEBUG(3, ("Failed to open tdb '%s'\n", src_path));
266 if (tdb_lockall(src_tdb) != 0) {
267 DEBUG(3, ("Failed to lock tdb '%s'\n", src_path));
271 tmp_path = talloc_asprintf(ctx, "%s%s", dst_path, ".tmp");
273 dst_tdb = tdb_open_log(tmp_path,
274 hash_size ? hash_size : tdb_hash_size(src_tdb),
275 TDB_DEFAULT, O_RDWR | O_CREAT | O_EXCL,
277 if (dst_tdb == NULL) {
278 DEBUG(3, ("Error creating tdb '%s': %s\n", tmp_path,
285 count1 = tdb_copy(src_tdb, dst_tdb);
287 DEBUG(3, ("Failed to copy tdb '%s': %s\n", src_path,
293 /* reopen ro and do basic verification */
295 dst_tdb = tdb_open_log(tmp_path, 0, TDB_DEFAULT, O_RDONLY, 0);
297 DEBUG(3, ("Failed to reopen tdb '%s': %s\n", tmp_path,
301 count2 = tdb_verify_basic(dst_tdb);
302 if (count2 != count1) {
303 DEBUG(3, ("Failed to verify result of copying tdb '%s'.\n",
309 DEBUG(10, ("tdb_backup: successfully copied %d entries\n", count1));
311 /* make sure the new tdb has reached stable storage
312 * then rename it to its destination */
313 fsync(tdb_fd(dst_tdb));
316 if (rename(tmp_path, dst_path) != 0) {
317 DEBUG(3, ("Failed to rename '%s' to '%s': %s\n",
318 tmp_path, dst_path, strerror(errno)));
326 if (src_tdb != NULL) {
329 if (tmp_path != NULL) {
331 TALLOC_FREE(tmp_path);
333 if (saved_errno != 0) {
339 static int rename_file_with_suffix(TALLOC_CTX *ctx, const char *path,
345 dst_path = talloc_asprintf(ctx, "%s%s", path, suffix);
347 ret = (rename(path, dst_path) != 0);
350 DEBUG(5, ("moved '%s' to '%s'\n", path, dst_path));
351 } else if (errno == ENOENT) {
352 DEBUG(3, ("file '%s' does not exist - so not moved\n", path));
355 DEBUG(3, ("error renaming %s to %s: %s\n", path, dst_path,
359 TALLOC_FREE(dst_path);
364 * do a backup of a tdb, moving the destination out of the way first
366 static int tdb_backup_with_rotate(TALLOC_CTX *ctx, const char *src_path,
367 const char *dst_path, int hash_size,
368 const char *rotate_suffix,
369 bool retry_norotate_if_nospc,
370 bool rename_as_last_resort_if_nospc)
374 rename_file_with_suffix(ctx, dst_path, rotate_suffix);
376 ret = tdb_backup(ctx, src_path, dst_path, hash_size);
379 DEBUG(10, ("backup of %s failed: %s\n", src_path, strerror(errno)));
381 if ((ret != 0) && (errno == ENOSPC) && retry_norotate_if_nospc)
383 char *rotate_path = talloc_asprintf(ctx, "%s%s", dst_path,
385 DEBUG(10, ("backup of %s failed due to lack of space\n",
387 DEBUGADD(10, ("trying to free some space by removing rotated "
388 "dst %s\n", rotate_path));
389 if (unlink(rotate_path) == -1) {
390 DEBUG(10, ("unlink of %s failed: %s\n", rotate_path,
393 ret = tdb_backup(ctx, src_path, dst_path, hash_size);
395 TALLOC_FREE(rotate_path);
398 if ((ret != 0) && (errno == ENOSPC) && rename_as_last_resort_if_nospc)
400 DEBUG(10, ("backup of %s failed due to lack of space\n",
402 DEBUGADD(10, ("using 'rename' as a last resort\n"));
403 ret = rename(src_path, dst_path);
410 * validation function with backup handling:
412 * - calls tdb_validate
413 * - if the tdb is ok, create a backup "name.bak", possibly moving
414 * existing backup to name.bak.old,
415 * return 0 (success) even if the backup fails
416 * - if the tdb is corrupt:
417 * - move the tdb to "name.corrupt"
418 * - check if there is valid backup.
419 * if so, restore the backup.
420 * if restore is successful, return 0 (success),
421 * - otherwise return -1 (failure)
423 int tdb_validate_and_backup(const char *tdb_path,
424 tdb_validate_data_func validate_fn)
427 const char *backup_suffix = ".bak";
428 const char *corrupt_suffix = ".corrupt";
429 const char *rotate_suffix = ".old";
430 char *tdb_path_backup;
432 TALLOC_CTX *ctx = NULL;
434 ctx = talloc_new(NULL);
436 DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
440 tdb_path_backup = talloc_asprintf(ctx, "%s%s", tdb_path, backup_suffix);
442 ret = tdb_validate_open(tdb_path, validate_fn);
445 DEBUG(1, ("tdb '%s' is valid\n", tdb_path));
446 ret = tdb_backup_with_rotate(ctx, tdb_path, tdb_path_backup, 0,
447 rotate_suffix, True, False);
449 DEBUG(1, ("Error creating backup of tdb '%s'\n",
451 /* the actual validation was successful: */
454 DEBUG(1, ("Created backup '%s' of tdb '%s'\n",
455 tdb_path_backup, tdb_path));
458 DEBUG(1, ("tdb '%s' is invalid\n", tdb_path));
460 ret =stat(tdb_path_backup, &st);
462 DEBUG(5, ("Could not stat '%s': %s\n", tdb_path_backup,
464 DEBUG(1, ("No backup found.\n"));
466 DEBUG(1, ("backup '%s' found.\n", tdb_path_backup));
467 ret = tdb_validate_open(tdb_path_backup, validate_fn);
469 DEBUG(1, ("Backup '%s' is invalid.\n",
475 int renamed = rename_file_with_suffix(ctx, tdb_path,
478 DEBUG(1, ("Error moving tdb to '%s%s'\n",
479 tdb_path, corrupt_suffix));
481 DEBUG(1, ("Corrupt tdb stored as '%s%s'\n",
482 tdb_path, corrupt_suffix));
487 DEBUG(1, ("valid backup '%s' found\n", tdb_path_backup));
488 ret = tdb_backup_with_rotate(ctx, tdb_path_backup, tdb_path, 0,
489 corrupt_suffix, True, True);
491 DEBUG(1, ("Error restoring backup from '%s'\n",
494 DEBUG(1, ("Restored tdb backup from '%s'\n",