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 extern int optind;
  73 extern char *optarg;
  74
  75 /*
  76   see if one file is newer than another
  77 */
  78 static int file_newer(const char *fname1, const char *fname2)
  79 {
  80         struct stat st1, st2;
  81         if (stat(fname1, &st1) != 0) {
  82                 return 0;
  83         }
  84         if (stat(fname2, &st2) != 0) {
  85                 return 1;
  86         }
  87         return (st1.st_mtime > st2.st_mtime);
  88 }
  89
  90 static void usage(void)
  91 {
  92         printf("Usage: tdbbackup [options] <fname...>\n\n");
  93         printf("   -h            this help message\n");
  94         printf("   -s suffix     set the backup suffix\n");
  95         printf("   -v            verify mode (restore if corrupt)\n");
  96 }
  97
  98
  99  int main(int argc, char *argv[])
 100 {
 101         int i;
 102         int ret = 0;
 103         int c;
 104         int verify = 0;
 105         const char *suffix = ".bak";
 106
 107         while ((c = getopt(argc, argv, "vhs:")) != -1) {
 108                 switch (c) {
 109                 case 'h':
 110                         usage();
 111                         exit(0);
 112                 case 'v':
 113                         verify = 1;
 114                         break;
 115                 case 's':
 116                         suffix = optarg;
 117                         break;
 118                 }
 119         }
 120
 121         argc -= optind;
 122         argv += optind;
 123
 124         if (argc < 1) {
 125                 usage();
 126                 exit(1);
 127         }
 128
 129         for (i=0; i<argc; i++) {
 130                 const char *fname = argv[i];
 131                 char *bak_name;
 132
 133                 bak_name = add_suffix(fname, suffix);
 134
 135                 if (verify) {
 136                         if (verify_tdb(fname, bak_name) != 0) {
 137                                 ret = 1;
 138                         }
 139                 } else {
 140                         if (file_newer(fname, bak_name) &&
 141                             backup_tdb(fname, bak_name) != 0) {
 142                                 ret = 1;
 143                         }
 144                 }
 145
 146                 free(bak_name);
 147         }
 148
 149         return ret;
 150 }