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mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-30 14:55:26 +03:00
systemd-stable/tdb/tdbback.c

202 lines
4.4 KiB
C

/*
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 2 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <time.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <ctype.h>
#include <signal.h>
#include "tdb.h"
static int failed;
char *add_suffix(const char *name, const char *suffix)
{
char *ret;
int len = strlen(name) + strlen(suffix) + 1;
ret = malloc(len);
if (!ret) {
fprintf(stderr,"Out of memory!\n");
exit(1);
}
strncpy(ret, name, len);
strncat(ret, suffix, len);
return ret;
}
static int copy_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
{
TDB_CONTEXT *tdb_new = (TDB_CONTEXT *)state;
if (tdb_store(tdb_new, key, dbuf, TDB_INSERT) != 0) {
fprintf(stderr,"Failed to insert into %s\n", tdb_new->name);
failed = 1;
return 1;
}
return 0;
}
static int test_fn(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
*/
int backup_tdb(const char *old_name, const char *new_name)
{
TDB_CONTEXT *tdb;
TDB_CONTEXT *tdb_new;
char *tmp_name;
struct stat st;
int count1, count2;
tmp_name = add_suffix(new_name, ".tmp");
/* stat the old tdb to find its permissions */
if (stat(old_name, &st) != 0) {
perror(old_name);
return 1;
}
/* open the old tdb */
tdb = tdb_open(old_name, 0, 0, O_RDWR, 0);
if (!tdb) {
printf("Failed to open %s\n", old_name);
return 1;
}
/* create the new tdb */
unlink(tmp_name);
tdb_new = tdb_open(tmp_name, tdb->header.hash_size,
TDB_DEFAULT, O_RDWR|O_CREAT|O_EXCL,
st.st_mode & 0777);
if (!tdb_new) {
perror(tmp_name);
free(tmp_name);
return 1;
}
/* lock the old tdb */
if (tdb_lockall(tdb) != 0) {
fprintf(stderr,"Failed to lock %s\n", old_name);
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);
/* close the new tdb and re-open read-only */
tdb_close(tdb_new);
tdb_new = tdb_open(tmp_name, 0, TDB_DEFAULT, O_RDONLY, 0);
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, 0);
if (count2 != count1) {
fprintf(stderr,"failed to copy %s\n", old_name);
tdb_close(tdb_new);
unlink(tmp_name);
free(tmp_name);
return 1;
}
/* make sure the new tdb has reached stable storage */
fsync(tdb_new->fd);
/* close the new tdb and rename it to .bak */
tdb_close(tdb_new);
unlink(new_name);
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
*/
int verify_tdb(const char *fname, const char *bak_name)
{
TDB_CONTEXT *tdb;
int count = -1;
/* open the tdb */
tdb = tdb_open(fname, 0, 0, O_RDONLY, 0);
/* 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);
}
printf("%s : %d records\n", fname, count);
return 0;
}