--- /dev/null
+/*
+ Unix SMB/CIFS implementation.
+ low level tdb backup and restore utility
+ Copyright (C) Andrew Tridgell 2002
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/*
+
+ This program is meant for backup/restore of tdb databases. Typical usage would be:
+ tdbbackup *.tdb
+ when Samba shuts down cleanly, which will make a backup of all the local databases
+ to *.bak files. Then on Samba startup you would use:
+ tdbbackup -v *.tdb
+ and this will check the databases for corruption and if corruption is detected then
+ the backup will be restored.
+
+ You may also like to do a backup on a regular basis while Samba is
+ running, perhaps using cron.
+
+ The reason this program is needed is to cope with power failures
+ while Samba is running. A power failure could lead to database
+ corruption and Samba will then not start correctly.
+
+ Note that many of the databases in Samba are transient and thus
+ don't need to be backed up, so you can optimise the above a little
+ by only running the backup on the critical databases.
+
+ */
+
+#include "tdb2.h"
+#include "system/filesys.h"
+
+/* Currently we default to creating a tdb1. This will change! */
+#define TDB2_IS_DEFAULT false
+
+#ifdef HAVE_GETOPT_H
+#include <getopt.h>
+#endif
+
+static int failed;
+
+static void tdb_log(struct tdb_context *tdb,
+ enum tdb_log_level level,
+ enum TDB_ERROR ecode,
+ const char *message,
+ void *data)
+{
+ fprintf(stderr, "%s:%s\n", tdb_errorstr(ecode), message);
+}
+
+static char *add_suffix(const char *name, const char *suffix)
+{
+ char *ret;
+ int len = strlen(name) + strlen(suffix) + 1;
+ ret = (char *)malloc(len);
+ if (!ret) {
+ fprintf(stderr,"Out of memory!\n");
+ exit(1);
+ }
+ snprintf(ret, len, "%s%s", name, suffix);
+ return ret;
+}
+
+static int copy_fn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
+{
+ struct tdb_context *tdb_new = (struct tdb_context *)state;
+ enum TDB_ERROR err;
+
+ err = tdb_store(tdb_new, key, dbuf, TDB_INSERT);
+ if (err) {
+ fprintf(stderr,"Failed to insert into %s: %s\n",
+ tdb_name(tdb_new), tdb_errorstr(err));
+ failed = 1;
+ return 1;
+ }
+ return 0;
+}
+
+
+static int test_fn(struct tdb_context *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
+{
+ return 0;
+}
+
+/*
+ carefully backup a tdb, validating the contents and
+ only doing the backup if its OK
+ this function is also used for restore
+*/
+static int backup_tdb(const char *old_name, const char *new_name,
+ bool tdb2, int hash_size)
+{
+ struct tdb_context *tdb;
+ struct tdb_context *tdb_new;
+ char *tmp_name;
+ struct stat st;
+ int count1, count2;
+ enum TDB_ERROR err;
+ union tdb_attribute log_attr, hsize_attr;
+ int tdb_flags = TDB_DEFAULT;
+
+ if (!tdb2) {
+ tdb_flags |= TDB_VERSION1;
+ }
+
+ tmp_name = add_suffix(new_name, ".tmp");
+
+ /* stat the old tdb to find its permissions */
+ if (stat(old_name, &st) != 0) {
+ perror(old_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ log_attr.base.attr = TDB_ATTRIBUTE_LOG;
+ log_attr.base.next = NULL;
+ log_attr.log.fn = tdb_log;
+
+ /* open the old tdb */
+ tdb = tdb_open(old_name, TDB_DEFAULT, O_RDWR, 0, &log_attr);
+ if (!tdb) {
+ printf("Failed to open %s\n", old_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ /* create the new tdb */
+ if (!tdb2 && hash_size) {
+ hsize_attr.base.attr = TDB_ATTRIBUTE_TDB1_HASHSIZE;
+ hsize_attr.base.next = NULL;
+ hsize_attr.tdb1_hashsize.hsize = hash_size;
+ log_attr.base.next = &hsize_attr;
+ }
+
+ unlink(tmp_name);
+ tdb_new = tdb_open(tmp_name, tdb_flags,
+ O_RDWR|O_CREAT|O_EXCL, st.st_mode & 0777,
+ &log_attr);
+ if (!tdb_new) {
+ perror(tmp_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ err = tdb_transaction_start(tdb);
+ if (err) {
+ fprintf(stderr, "Failed to start transaction on old tdb: %s\n",
+ tdb_errorstr(err));
+ tdb_close(tdb);
+ tdb_close(tdb_new);
+ unlink(tmp_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ /* lock the backup tdb so that nobody else can change it */
+ err = tdb_lockall(tdb_new);
+ if (err) {
+ fprintf(stderr, "Failed to lock backup tdb: %s\n",
+ tdb_errorstr(err));
+ tdb_close(tdb);
+ tdb_close(tdb_new);
+ unlink(tmp_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ failed = 0;
+
+ /* traverse and copy */
+ count1 = tdb_traverse(tdb, copy_fn, (void *)tdb_new);
+ if (count1 < 0 || failed) {
+ fprintf(stderr,"failed to copy %s\n", old_name);
+ tdb_close(tdb);
+ tdb_close(tdb_new);
+ unlink(tmp_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ /* close the old tdb */
+ tdb_close(tdb);
+
+ /* copy done, unlock the backup tdb */
+ tdb_unlockall(tdb_new);
+
+#ifdef HAVE_FDATASYNC
+ if (fdatasync(tdb_fd(tdb_new)) != 0) {
+#else
+ if (fsync(tdb_fd(tdb_new)) != 0) {
+#endif
+ /* not fatal */
+ fprintf(stderr, "failed to fsync backup file\n");
+ }
+
+ /* close the new tdb and re-open read-only */
+ tdb_close(tdb_new);
+
+ /* we don't need the hash attr any more */
+ log_attr.base.next = NULL;
+
+ tdb_new = tdb_open(tmp_name, TDB_DEFAULT, O_RDONLY, 0, &log_attr);
+ if (!tdb_new) {
+ fprintf(stderr,"failed to reopen %s\n", tmp_name);
+ unlink(tmp_name);
+ perror(tmp_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ /* traverse the new tdb to confirm */
+ count2 = tdb_traverse(tdb_new, test_fn, NULL);
+ if (count2 != count1) {
+ fprintf(stderr,"failed to copy %s\n", old_name);
+ tdb_close(tdb_new);
+ unlink(tmp_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ /* close the new tdb and rename it to .bak */
+ tdb_close(tdb_new);
+ if (rename(tmp_name, new_name) != 0) {
+ perror(new_name);
+ free(tmp_name);
+ return 1;
+ }
+
+ free(tmp_name);
+
+ return 0;
+}
+
+/*
+ verify a tdb and if it is corrupt then restore from *.bak
+*/
+static int verify_tdb(const char *fname, const char *bak_name)
+{
+ struct tdb_context *tdb;
+ int count = -1;
+ union tdb_attribute log_attr;
+
+ log_attr.base.attr = TDB_ATTRIBUTE_LOG;
+ log_attr.base.next = NULL;
+ log_attr.log.fn = tdb_log;
+
+ /* open the tdb */
+ tdb = tdb_open(fname, TDB_DEFAULT, O_RDONLY, 0, &log_attr);
+
+ /* traverse the tdb, then close it */
+ if (tdb) {
+ count = tdb_traverse(tdb, test_fn, NULL);
+ tdb_close(tdb);
+ }
+
+ /* count is < 0 means an error */
+ if (count < 0) {
+ printf("restoring %s\n", fname);
+ return backup_tdb(bak_name, fname, TDB2_IS_DEFAULT, 0);
+ }
+
+ printf("%s : %d records\n", fname, count);
+
+ return 0;
+}
+
+/*
+ see if one file is newer than another
+*/
+static int file_newer(const char *fname1, const char *fname2)
+{
+ struct stat st1, st2;
+ if (stat(fname1, &st1) != 0) {
+ return 0;
+ }
+ if (stat(fname2, &st2) != 0) {
+ return 1;
+ }
+ return (st1.st_mtime > st2.st_mtime);
+}
+
+static void usage(void)
+{
+ printf("Usage: tdbbackup [options] <fname...>\n\n");
+ printf(" -h this help message\n");
+ printf(" -1 make the backup a TDB1 file\n");
+ printf(" -2 make the backup a TDB2 file\n");
+ printf(" -v verify mode (restore if corrupt)\n");
+ printf(" -s suffix set the backup suffix\n");
+ printf(" -v verify mode (restore if corrupt)\n");
+ printf(" -n hashsize set the new hash size for the backup\n");
+}
+
+
+ int main(int argc, char *argv[])
+{
+ int i;
+ int ret = 0;
+ int c;
+ int verify = 0;
+ int hashsize = 0;
+ bool tdb2 = TDB2_IS_DEFAULT;
+ const char *suffix = ".bak";
+
+ while ((c = getopt(argc, argv, "vhs:n:12")) != -1) {
+ switch (c) {
+ case 'h':
+ usage();
+ exit(0);
+ case 'v':
+ verify = 1;
+ break;
+ case '1':
+ tdb2 = false;
+ break;
+ case '2':
+ tdb2 = true;
+ break;
+ case 's':
+ suffix = optarg;
+ break;
+ case 'n':
+ hashsize = atoi(optarg);
+ break;
+ }
+ }
+
+ argc -= optind;
+ argv += optind;
+
+ if (argc < 1) {
+ usage();
+ exit(1);
+ }
+
+ for (i=0; i<argc; i++) {
+ const char *fname = argv[i];
+ char *bak_name;
+
+ bak_name = add_suffix(fname, suffix);
+
+ if (verify) {
+ if (verify_tdb(fname, bak_name) != 0) {
+ ret = 1;
+ }
+ } else {
+ if (file_newer(fname, bak_name) &&
+ backup_tdb(fname, bak_name, tdb2, hashsize) != 0) {
+ ret = 1;
+ }
+ }
+
+ free(bak_name);
+ }
+
+ return ret;
+}
git.samba.org / tridge / samba.git / commitdiff