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 "system/filesys.h"
24 #include "tdb_validate.h"
27 * internal validation function, executed by the child.
29 static int tdb_validate_child(struct tdb_context *tdb,
30 tdb_validate_data_func validate_fn)
34 struct tdb_validation_status v_status;
36 v_status.tdb_error = False;
37 v_status.bad_freelist = False;
38 v_status.bad_entry = False;
39 v_status.unknown_key = False;
40 v_status.success = True;
43 v_status.tdb_error = True;
44 v_status.success = False;
49 * we can simplify this by passing a check function,
50 * but I don't want to change all the callers...
52 ret = tdb_check(tdb, NULL, NULL);
54 v_status.tdb_error = True;
55 v_status.success = False;
59 /* Check if the tdb's freelist is good. */
60 if (tdb_validate_freelist(tdb, &num_entries) == -1) {
61 v_status.bad_freelist = True;
62 v_status.success = False;
66 DEBUG(10,("tdb_validate_child: tdb %s freelist has %d entries\n",
67 tdb_name(tdb), num_entries));
69 /* Now traverse the tdb to validate it. */
70 num_entries = tdb_traverse(tdb, validate_fn, (void *)&v_status);
71 if (!v_status.success) {
73 } else if (num_entries == -1) {
74 v_status.tdb_error = True;
75 v_status.success = False;
79 DEBUG(10,("tdb_validate_child: tdb %s is good with %d entries\n",
80 tdb_name(tdb), num_entries));
81 ret = 0; /* Cache is good. */
84 DEBUG(10, ("tdb_validate_child: summary of validation status:\n"));
85 DEBUGADD(10,(" * tdb error: %s\n", v_status.tdb_error ? "yes" : "no"));
86 DEBUGADD(10,(" * bad freelist: %s\n",v_status.bad_freelist?"yes":"no"));
87 DEBUGADD(10,(" * bad entry: %s\n", v_status.bad_entry ? "yes" : "no"));
88 DEBUGADD(10,(" * unknown key: %s\n", v_status.unknown_key?"yes":"no"));
89 DEBUGADD(10,(" => overall success: %s\n", v_status.success?"yes":"no"));
95 * tdb validation function.
96 * returns 0 if tdb is ok, != 0 if it isn't.
97 * this function expects an opened tdb.
99 int tdb_validate(struct tdb_context *tdb, tdb_validate_data_func validate_fn)
101 pid_t child_pid = -1;
102 int child_status = 0;
107 DEBUG(1, ("Error: tdb_validate called with tdb == NULL\n"));
111 DEBUG(5, ("tdb_validate called for tdb '%s'\n", tdb_name(tdb)));
113 /* fork and let the child do the validation.
114 * benefit: no need to twist signal handlers and panic functions.
115 * just let the child panic. we catch the signal. */
117 DEBUG(10, ("tdb_validate: forking to let child do validation.\n"));
118 child_pid = sys_fork();
119 if (child_pid == 0) {
121 DEBUG(10, ("tdb_validate (validation child): created\n"));
122 DEBUG(10, ("tdb_validate (validation child): "
123 "calling tdb_validate_child\n"));
124 exit(tdb_validate_child(tdb, validate_fn));
126 else if (child_pid < 0) {
127 DEBUG(1, ("tdb_validate: fork for validation failed.\n"));
133 DEBUG(10, ("tdb_validate: fork succeeded, child PID = %u\n",
134 (unsigned int)child_pid));
136 DEBUG(10, ("tdb_validate: waiting for child to finish...\n"));
137 while ((wait_pid = sys_waitpid(child_pid, &child_status, 0)) < 0) {
138 if (errno == EINTR) {
139 DEBUG(10, ("tdb_validate: got signal during waitpid, "
144 DEBUG(1, ("tdb_validate: waitpid failed with error '%s'.\n",
148 if (wait_pid != child_pid) {
149 DEBUG(1, ("tdb_validate: waitpid returned pid %d, "
150 "but %u was expected\n", wait_pid, (unsigned int)child_pid));
154 DEBUG(10, ("tdb_validate: validating child returned.\n"));
155 if (WIFEXITED(child_status)) {
156 DEBUG(10, ("tdb_validate: child exited, code %d.\n",
157 WEXITSTATUS(child_status)));
158 ret = WEXITSTATUS(child_status);
160 if (WIFSIGNALED(child_status)) {
161 DEBUG(10, ("tdb_validate: child terminated by signal %d\n",
162 WTERMSIG(child_status)));
164 if (WCOREDUMP(child_status)) {
165 DEBUGADD(10, ("core dumped\n"));
168 ret = WTERMSIG(child_status);
170 if (WIFSTOPPED(child_status)) {
171 DEBUG(10, ("tdb_validate: child was stopped by signal %d\n",
172 WSTOPSIG(child_status)));
173 ret = WSTOPSIG(child_status);
177 DEBUG(5, ("tdb_validate returning code '%d' for tdb '%s'\n", ret,
184 * tdb validation function.
185 * returns 0 if tdb is ok, != 0 if it isn't.
186 * this is a wrapper around the actual validation function that opens and closes
189 int tdb_validate_open(const char *tdb_path, tdb_validate_data_func validate_fn)
191 TDB_CONTEXT *tdb = NULL;
194 DEBUG(5, ("tdb_validate_open called for tdb '%s'\n", tdb_path));
196 tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDWR, 0);
198 DEBUG(1, ("Error opening tdb %s\n", tdb_path));
202 ret = tdb_validate(tdb, validate_fn);
208 * tdb backup function and helpers for tdb_validate wrapper with backup
212 /* this structure eliminates the need for a global overall status for
213 * the traverse-copy */
214 struct tdb_copy_data {
215 struct tdb_context *dst;
219 static int traverse_copy_fn(struct tdb_context *tdb, TDB_DATA key,
220 TDB_DATA dbuf, void *private_data)
222 struct tdb_copy_data *data = (struct tdb_copy_data *)private_data;
224 if (tdb_store(data->dst, key, dbuf, TDB_INSERT) != 0) {
225 DEBUG(4, ("Failed to insert into %s: %s\n", tdb_name(data->dst),
227 data->success = False;
233 static int tdb_copy(struct tdb_context *src, struct tdb_context *dst)
235 struct tdb_copy_data data;
241 count = tdb_traverse(src, traverse_copy_fn, (void *)(&data));
242 if ((count < 0) || (data.success == False)) {
248 static int tdb_verify_basic(struct tdb_context *tdb)
250 return tdb_traverse(tdb, NULL, NULL);
253 /* this backup function is essentially taken from lib/tdb/tools/tdbbackup.tdb
255 static int tdb_backup(TALLOC_CTX *ctx, const char *src_path,
256 const char *dst_path, int hash_size)
258 struct tdb_context *src_tdb = NULL;
259 struct tdb_context *dst_tdb = NULL;
260 char *tmp_path = NULL;
266 if (stat(src_path, &st) != 0) {
267 DEBUG(3, ("Could not stat '%s': %s\n", src_path,
272 /* open old tdb RDWR - so we can lock it */
273 src_tdb = tdb_open_log(src_path, 0, TDB_DEFAULT, O_RDWR, 0);
274 if (src_tdb == NULL) {
275 DEBUG(3, ("Failed to open tdb '%s'\n", src_path));
279 if (tdb_lockall(src_tdb) != 0) {
280 DEBUG(3, ("Failed to lock tdb '%s'\n", src_path));
284 tmp_path = talloc_asprintf(ctx, "%s%s", dst_path, ".tmp");
286 DEBUG(3, ("talloc fail\n"));
291 dst_tdb = tdb_open_log(tmp_path,
292 hash_size ? hash_size : tdb_hash_size(src_tdb),
293 TDB_DEFAULT, O_RDWR | O_CREAT | O_EXCL,
295 if (dst_tdb == NULL) {
296 DEBUG(3, ("Error creating tdb '%s': %s\n", tmp_path,
303 count1 = tdb_copy(src_tdb, dst_tdb);
305 DEBUG(3, ("Failed to copy tdb '%s': %s\n", src_path,
311 /* reopen ro and do basic verification */
313 dst_tdb = tdb_open_log(tmp_path, 0, TDB_DEFAULT, O_RDONLY, 0);
315 DEBUG(3, ("Failed to reopen tdb '%s': %s\n", tmp_path,
319 count2 = tdb_verify_basic(dst_tdb);
320 if (count2 != count1) {
321 DEBUG(3, ("Failed to verify result of copying tdb '%s'.\n",
327 DEBUG(10, ("tdb_backup: successfully copied %d entries\n", count1));
329 /* make sure the new tdb has reached stable storage
330 * then rename it to its destination */
331 fsync(tdb_fd(dst_tdb));
334 if (rename(tmp_path, dst_path) != 0) {
335 DEBUG(3, ("Failed to rename '%s' to '%s': %s\n",
336 tmp_path, dst_path, strerror(errno)));
344 if (src_tdb != NULL) {
347 if (tmp_path != NULL) {
349 TALLOC_FREE(tmp_path);
351 if (saved_errno != 0) {
357 static int rename_file_with_suffix(TALLOC_CTX *ctx, const char *path,
363 dst_path = talloc_asprintf(ctx, "%s%s", path, suffix);
364 if (dst_path == NULL) {
365 DEBUG(3, ("error out of memory\n"));
369 ret = (rename(path, dst_path) != 0);
372 DEBUG(5, ("moved '%s' to '%s'\n", path, dst_path));
373 } else if (errno == ENOENT) {
374 DEBUG(3, ("file '%s' does not exist - so not moved\n", path));
377 DEBUG(3, ("error renaming %s to %s: %s\n", path, dst_path,
381 TALLOC_FREE(dst_path);
386 * do a backup of a tdb, moving the destination out of the way first
388 static int tdb_backup_with_rotate(TALLOC_CTX *ctx, const char *src_path,
389 const char *dst_path, int hash_size,
390 const char *rotate_suffix,
391 bool retry_norotate_if_nospc,
392 bool rename_as_last_resort_if_nospc)
396 rename_file_with_suffix(ctx, dst_path, rotate_suffix);
398 ret = tdb_backup(ctx, src_path, dst_path, hash_size);
401 DEBUG(10, ("backup of %s failed: %s\n", src_path, strerror(errno)));
403 if ((ret != 0) && (errno == ENOSPC) && retry_norotate_if_nospc)
405 char *rotate_path = talloc_asprintf(ctx, "%s%s", dst_path,
407 if (rotate_path == NULL) {
408 DEBUG(10, ("talloc fail\n"));
411 DEBUG(10, ("backup of %s failed due to lack of space\n",
413 DEBUGADD(10, ("trying to free some space by removing rotated "
414 "dst %s\n", rotate_path));
415 if (unlink(rotate_path) == -1) {
416 DEBUG(10, ("unlink of %s failed: %s\n", rotate_path,
419 ret = tdb_backup(ctx, src_path, dst_path, hash_size);
421 TALLOC_FREE(rotate_path);
424 if ((ret != 0) && (errno == ENOSPC) && rename_as_last_resort_if_nospc)
426 DEBUG(10, ("backup of %s failed due to lack of space\n",
428 DEBUGADD(10, ("using 'rename' as a last resort\n"));
429 ret = rename(src_path, dst_path);
436 * validation function with backup handling:
438 * - calls tdb_validate
439 * - if the tdb is ok, create a backup "name.bak", possibly moving
440 * existing backup to name.bak.old,
441 * return 0 (success) even if the backup fails
442 * - if the tdb is corrupt:
443 * - move the tdb to "name.corrupt"
444 * - check if there is valid backup.
445 * if so, restore the backup.
446 * if restore is successful, return 0 (success),
447 * - otherwise return -1 (failure)
449 int tdb_validate_and_backup(const char *tdb_path,
450 tdb_validate_data_func validate_fn)
453 const char *backup_suffix = ".bak";
454 const char *corrupt_suffix = ".corrupt";
455 const char *rotate_suffix = ".old";
456 char *tdb_path_backup;
458 TALLOC_CTX *ctx = NULL;
460 ctx = talloc_new(NULL);
462 DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
466 tdb_path_backup = talloc_asprintf(ctx, "%s%s", tdb_path, backup_suffix);
467 if (!tdb_path_backup) {
468 DEBUG(0, ("tdb_validate_and_backup: out of memory\n"));
472 ret = tdb_validate_open(tdb_path, validate_fn);
475 DEBUG(1, ("tdb '%s' is valid\n", tdb_path));
476 ret = tdb_backup_with_rotate(ctx, tdb_path, tdb_path_backup, 0,
477 rotate_suffix, True, False);
479 DEBUG(1, ("Error creating backup of tdb '%s'\n",
481 /* the actual validation was successful: */
484 DEBUG(1, ("Created backup '%s' of tdb '%s'\n",
485 tdb_path_backup, tdb_path));
488 DEBUG(1, ("tdb '%s' is invalid\n", tdb_path));
490 ret =stat(tdb_path_backup, &st);
492 DEBUG(5, ("Could not stat '%s': %s\n", tdb_path_backup,
494 DEBUG(1, ("No backup found.\n"));
496 DEBUG(1, ("backup '%s' found.\n", tdb_path_backup));
497 ret = tdb_validate_open(tdb_path_backup, validate_fn);
499 DEBUG(1, ("Backup '%s' is invalid.\n",
505 int renamed = rename_file_with_suffix(ctx, tdb_path,
508 DEBUG(1, ("Error moving tdb to '%s%s'\n",
509 tdb_path, corrupt_suffix));
511 DEBUG(1, ("Corrupt tdb stored as '%s%s'\n",
512 tdb_path, corrupt_suffix));
517 DEBUG(1, ("valid backup '%s' found\n", tdb_path_backup));
518 ret = tdb_backup_with_rotate(ctx, tdb_path_backup, tdb_path, 0,
519 corrupt_suffix, True, True);
521 DEBUG(1, ("Error restoring backup from '%s'\n",
524 DEBUG(1, ("Restored tdb backup from '%s'\n",