source/tdb/tdbback.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 #ifdef STANDALONE
  22 #if HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <errno.h>
  27 #include <stdlib.h>
  28 #include <stdio.h>
  29 #include <fcntl.h>
  30 #include <unistd.h>
  31 #include <string.h>
  32 #include <fcntl.h>
  33 #include <time.h>
  34 #include <sys/mman.h>
  35
  36 #include <sys/stat.h>
  37 #include <sys/time.h>
  38 #include <ctype.h>
  39 #include <signal.h>
  40
  41 #else
  42 #include "includes.h"
  43 #endif
  44
  45 #include "tdb.h"
  46
  47 static int failed;
  48
  49 char *add_suffix(const char *name, const char *suffix)
  50 {
  51         char *ret;
  52         int len = strlen(name) + strlen(suffix) + 1;
  53         ret = malloc(len);
  54         if (!ret) {
  55                 fprintf(stderr,"Out of memory!\n");
  56                 exit(1);
  57         }
  58         snprintf(ret, len, "%s%s", name, suffix);
  59         return ret;
  60 }
  61
  62 static int copy_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
  63 {
  64         TDB_CONTEXT *tdb_new = (TDB_CONTEXT *)state;
  65
  66         if (tdb_store(tdb_new, key, dbuf, TDB_INSERT) != 0) {
  67                 fprintf(stderr,"Failed to insert into %s\n", tdb_new->name);
  68                 failed = 1;
  69                 return 1;
  70         }
  71         return 0;
  72 }
  73
  74
  75 static int test_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
  76 {
  77         return 0;
  78 }
  79
  80 /*
  81   carefully backup a tdb, validating the contents and
  82   only doing the backup if its OK
  83   this function is also used for restore
  84 */
  85 int backup_tdb(const char *old_name, const char *new_name)
  86 {
  87         TDB_CONTEXT *tdb;
  88         TDB_CONTEXT *tdb_new;
  89         char *tmp_name;
  90         struct stat st;
  91         int count1, count2;
  92
  93         tmp_name = add_suffix(new_name, ".tmp");
  94
  95         /* stat the old tdb to find its permissions */
  96         if (stat(old_name, &st) != 0) {
  97                 perror(old_name);
  98                 return 1;
  99         }
 100
 101         /* open the old tdb */
 102         tdb = tdb_open(old_name, 0, 0, O_RDWR, 0);
 103         if (!tdb) {
 104                 printf("Failed to open %s\n", old_name);
 105                 return 1;
 106         }
 107
 108         /* create the new tdb */
 109         unlink(tmp_name);
 110         tdb_new = tdb_open(tmp_name, tdb->header.hash_size,
 111                            TDB_DEFAULT, O_RDWR|O_CREAT|O_EXCL,
 112                            st.st_mode & 0777);
 113         if (!tdb_new) {
 114                 perror(tmp_name);
 115                 free(tmp_name);
 116                 return 1;
 117         }
 118
 119         /* lock the old tdb */
 120         if (tdb_lockall(tdb) != 0) {
 121                 fprintf(stderr,"Failed to lock %s\n", old_name);
 122                 tdb_close(tdb);
 123                 tdb_close(tdb_new);
 124                 unlink(tmp_name);
 125                 free(tmp_name);
 126                 return 1;
 127         }
 128
 129         failed = 0;
 130
 131         /* traverse and copy */
 132         count1 = tdb_traverse(tdb, copy_fn, (void *)tdb_new);
 133         if (count1 < 0 || failed) {
 134                 fprintf(stderr,"failed to copy %s\n", old_name);
 135                 tdb_close(tdb);
 136                 tdb_close(tdb_new);
 137                 unlink(tmp_name);
 138                 free(tmp_name);
 139                 return 1;
 140         }
 141
 142         /* close the old tdb */
 143         tdb_close(tdb);
 144
 145         /* close the new tdb and re-open read-only */
 146         tdb_close(tdb_new);
 147         tdb_new = tdb_open(tmp_name, 0, TDB_DEFAULT, O_RDONLY, 0);
 148         if (!tdb_new) {
 149                 fprintf(stderr,"failed to reopen %s\n", tmp_name);
 150                 unlink(tmp_name);
 151                 perror(tmp_name);
 152                 free(tmp_name);
 153                 return 1;
 154         }
 155
 156         /* traverse the new tdb to confirm */
 157         count2 = tdb_traverse(tdb_new, test_fn, 0);
 158         if (count2 != count1) {
 159                 fprintf(stderr,"failed to copy %s\n", old_name);
 160                 tdb_close(tdb_new);
 161                 unlink(tmp_name);
 162                 free(tmp_name);
 163                 return 1;
 164         }
 165
 166         /* make sure the new tdb has reached stable storage */
 167         fsync(tdb_new->fd);
 168
 169         /* close the new tdb and rename it to .bak */
 170         tdb_close(tdb_new);
 171         unlink(new_name);
 172         if (rename(tmp_name, new_name) != 0) {
 173                 perror(new_name);
 174                 free(tmp_name);
 175                 return 1;
 176         }
 177
 178         free(tmp_name);
 179
 180         return 0;
 181 }
 182
 183
 184
 185 /*
 186   verify a tdb and if it is corrupt then restore from *.bak
 187 */
 188 int verify_tdb(const char *fname, const char *bak_name)
 189 {
 190         TDB_CONTEXT *tdb;
 191         int count = -1;
 192
 193         /* open the tdb */
 194         tdb = tdb_open(fname, 0, 0, O_RDONLY, 0);
 195
 196         /* traverse the tdb, then close it */
 197         if (tdb) {
 198                 count = tdb_traverse(tdb, test_fn, NULL);
 199                 tdb_close(tdb);
 200         }
 201
 202         /* count is < 0 means an error */
 203         if (count < 0) {
 204                 printf("restoring %s\n", fname);
 205                 return backup_tdb(bak_name, fname);
 206         }
 207
 208         printf("%s : %d records\n", fname, count);
 209
 210         return 0;
 211 }