source/tdb/tdbbackup.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    low level tdb backup and restore utility
   4    Copyright (C) Andrew Tridgell              2002
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 /*
  22
  23   This program is meant for backup/restore of tdb databases. Typical usage would be:
  24      tdbbackup *.tdb
  25   when Samba shuts down cleanly, which will make a backup of all the local databases
  26   to *.bak files. Then on Samba startup you would use:
  27      tdbbackup -v *.tdb
  28   and this will check the databases for corruption and if corruption is detected then
  29   the backup will be restored.
  30
  31   You may also like to do a backup on a regular basis while Samba is
  32   running, perhaps using cron.
  33
  34   The reason this program is needed is to cope with power failures
  35   while Samba is running. A power failure could lead to database
  36   corruption and Samba will then not start correctly.
  37
  38   Note that many of the databases in Samba are transient and thus
  39   don't need to be backed up, so you can optimise the above a little
  40   by only running the backup on the critical databases.
  41
  42  */
  43
  44 #ifdef STANDALONE
  45 #if HAVE_CONFIG_H
  46 #include <config.h>
  47 #endif
  48
  49 #include <errno.h>
  50 #include <stdlib.h>
  51 #include <stdio.h>
  52 #include <fcntl.h>
  53 #include <unistd.h>
  54 #include <string.h>
  55 #include <fcntl.h>
  56 #include <time.h>
  57 #include <sys/mman.h>
  58 #include <sys/stat.h>
  59 #include <sys/time.h>
  60 #include <ctype.h>
  61 #include <signal.h>
  62
  63 #else
  64
  65 #include "includes.h"
  66
  67 #endif
  68
  69 #include "tdb.h"
  70 #include "tdbback.h"
  71
  72 /*
  73   see if one file is newer than another
  74 */
  75 static int file_newer(const char *fname1, const char *fname2)
  76 {
  77         struct stat st1, st2;
  78         if (stat(fname1, &st1) != 0) {
  79                 return 0;
  80         }
  81         if (stat(fname2, &st2) != 0) {
  82                 return 1;
  83         }
  84         return (st1.st_mtime > st2.st_mtime);
  85 }
  86
  87 static void usage(void)
  88 {
  89         printf("Usage: tdbbackup [options] <fname...>\n\n");
  90         printf("   -h            this help message\n");
  91         printf("   -s suffix     set the backup suffix\n");
  92         printf("   -v            verify mode (restore if corrupt)\n");
  93 }
  94
  95
  96  int main(int argc, char *argv[])
  97 {
  98         int i;
  99         int ret = 0;
 100         int c;
 101         int verify = 0;
 102         const char *suffix = ".bak";
 103         extern int optind;
 104         extern char *optarg;
 105
 106         while ((c = getopt(argc, argv, "vhs:")) != -1) {
 107                 switch (c) {
 108                 case 'h':
 109                         usage();
 110                         exit(0);
 111                 case 'v':
 112                         verify = 1;
 113                         break;
 114                 case 's':
 115                         suffix = optarg;
 116                         break;
 117                 }
 118         }
 119
 120         argc -= optind;
 121         argv += optind;
 122
 123         if (argc < 1) {
 124                 usage();
 125                 exit(1);
 126         }
 127
 128         for (i=0; i<argc; i++) {
 129                 const char *fname = argv[i];
 130                 char *bak_name;
 131
 132                 bak_name = add_suffix(fname, suffix);
 133
 134                 if (verify) {
 135                         if (verify_tdb(fname, bak_name) != 0) {
 136                                 ret = 1;
 137                         }
 138                 } else {
 139                         if (file_newer(fname, bak_name) &&
 140                             backup_tdb(fname, bak_name) != 0) {
 141                                 ret = 1;
 142                         }
 143                 }
 144
 145                 free(bak_name);
 146         }
 147
 148         return ret;
 149 }