source: branches/samba-3.5.x/lib/tdb/tools/tdbbackup.c

Last change on this file was 414, checked in by Herwig Bauernfeind, 15 years ago

Samba 3.5.0: Initial import
File size: 7.4 KB
Line 
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 3 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, see <http://www.gnu.org/licenses/>.
18*/
19
20/*
21
22 This program is meant for backup/restore of tdb databases. Typical usage would be:
23 tdbbackup *.tdb
24 when Samba shuts down cleanly, which will make a backup of all the local databases
25 to *.bak files. Then on Samba startup you would use:
26 tdbbackup -v *.tdb
27 and this will check the databases for corruption and if corruption is detected then
28 the backup will be restored.
29
30 You may also like to do a backup on a regular basis while Samba is
31 running, perhaps using cron.
32
33 The reason this program is needed is to cope with power failures
34 while Samba is running. A power failure could lead to database
35 corruption and Samba will then not start correctly.
36
37 Note that many of the databases in Samba are transient and thus
38 don't need to be backed up, so you can optimise the above a little
39 by only running the backup on the critical databases.
40
41 */
42
43#include "replace.h"
44#include "system/locale.h"
45#include "system/time.h"
46#include "system/filesys.h"
47#include "system/wait.h"
48#include "tdb.h"
49
50#ifdef HAVE_GETOPT_H
51#include <getopt.h>
52#endif
53
54static int failed;
55
56static struct tdb_logging_context log_ctx;
57
58#ifdef PRINTF_ATTRIBUTE
59static void tdb_log(struct tdb_context *tdb, enum tdb_debug_level level, const char *format, ...) PRINTF_ATTRIBUTE(3,4);
60#endif
61static void tdb_log(struct tdb_context *tdb, enum tdb_debug_level level, const char *format, ...)
62{
63 va_list ap;
64
65 va_start(ap, format);
66 vfprintf(stdout, format, ap);
67 va_end(ap);
68 fflush(stdout);
69}
70
71static char *add_suffix(const char *name, const char *suffix)
72{
73 char *ret;
74 int len = strlen(name) + strlen(suffix) + 1;
75 ret = (char *)malloc(len);
76 if (!ret) {
77 fprintf(stderr,"Out of memory!\n");
78 exit(1);
79 }
80 snprintf(ret, len, "%s%s", name, suffix);
81 return ret;
82}
83
84static int copy_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
85{
86 TDB_CONTEXT *tdb_new = (TDB_CONTEXT *)state;
87
88 if (tdb_store(tdb_new, key, dbuf, TDB_INSERT) != 0) {
89 fprintf(stderr,"Failed to insert into %s\n", tdb_name(tdb_new));
90 failed = 1;
91 return 1;
92 }
93 return 0;
94}
95
96
97static int test_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
98{
99 return 0;
100}
101
102/*
103 carefully backup a tdb, validating the contents and
104 only doing the backup if its OK
105 this function is also used for restore
106*/
107static int backup_tdb(const char *old_name, const char *new_name, int hash_size)
108{
109 TDB_CONTEXT *tdb;
110 TDB_CONTEXT *tdb_new;
111 char *tmp_name;
112 struct stat st;
113 int count1, count2;
114
115 tmp_name = add_suffix(new_name, ".tmp");
116
117 /* stat the old tdb to find its permissions */
118 if (stat(old_name, &st) != 0) {
119 perror(old_name);
120 free(tmp_name);
121 return 1;
122 }
123
124 /* open the old tdb */
125 tdb = tdb_open_ex(old_name, 0, 0,
126 O_RDWR, 0, &log_ctx, NULL);
127 if (!tdb) {
128 printf("Failed to open %s\n", old_name);
129 free(tmp_name);
130 return 1;
131 }
132
133 /* create the new tdb */
134 unlink(tmp_name);
135 tdb_new = tdb_open_ex(tmp_name,
136 hash_size ? hash_size : tdb_hash_size(tdb),
137 TDB_DEFAULT,
138 O_RDWR|O_CREAT|O_EXCL, st.st_mode & 0777,
139 &log_ctx, NULL);
140 if (!tdb_new) {
141 perror(tmp_name);
142 free(tmp_name);
143 return 1;
144 }
145
146 if (tdb_transaction_start(tdb) != 0) {
147 printf("Failed to start transaction on old tdb\n");
148 tdb_close(tdb);
149 tdb_close(tdb_new);
150 unlink(tmp_name);
151 free(tmp_name);
152 return 1;
153 }
154
155 if (tdb_transaction_start(tdb_new) != 0) {
156 printf("Failed to start transaction on new tdb\n");
157 tdb_close(tdb);
158 tdb_close(tdb_new);
159 unlink(tmp_name);
160 free(tmp_name);
161 return 1;
162 }
163
164 failed = 0;
165
166 /* traverse and copy */
167 count1 = tdb_traverse(tdb, copy_fn, (void *)tdb_new);
168 if (count1 < 0 || failed) {
169 fprintf(stderr,"failed to copy %s\n", old_name);
170 tdb_close(tdb);
171 tdb_close(tdb_new);
172 unlink(tmp_name);
173 free(tmp_name);
174 return 1;
175 }
176
177 /* close the old tdb */
178 tdb_close(tdb);
179
180 if (tdb_transaction_commit(tdb_new) != 0) {
181 fprintf(stderr, "Failed to commit new tdb\n");
182 tdb_close(tdb_new);
183 unlink(tmp_name);
184 free(tmp_name);
185 return 1;
186 }
187
188 /* close the new tdb and re-open read-only */
189 tdb_close(tdb_new);
190 tdb_new = tdb_open_ex(tmp_name,
191 0,
192 TDB_DEFAULT,
193 O_RDONLY, 0,
194 &log_ctx, NULL);
195 if (!tdb_new) {
196 fprintf(stderr,"failed to reopen %s\n", tmp_name);
197 unlink(tmp_name);
198 perror(tmp_name);
199 free(tmp_name);
200 return 1;
201 }
202
203 /* traverse the new tdb to confirm */
204 count2 = tdb_traverse(tdb_new, test_fn, NULL);
205 if (count2 != count1) {
206 fprintf(stderr,"failed to copy %s\n", old_name);
207 tdb_close(tdb_new);
208 unlink(tmp_name);
209 free(tmp_name);
210 return 1;
211 }
212
213 /* close the new tdb and rename it to .bak */
214 tdb_close(tdb_new);
215 if (rename(tmp_name, new_name) != 0) {
216 perror(new_name);
217 free(tmp_name);
218 return 1;
219 }
220
221 free(tmp_name);
222
223 return 0;
224}
225
226/*
227 verify a tdb and if it is corrupt then restore from *.bak
228*/
229static int verify_tdb(const char *fname, const char *bak_name)
230{
231 TDB_CONTEXT *tdb;
232 int count = -1;
233
234 /* open the tdb */
235 tdb = tdb_open_ex(fname, 0, 0,
236 O_RDONLY, 0, &log_ctx, NULL);
237
238 /* traverse the tdb, then close it */
239 if (tdb) {
240 count = tdb_traverse(tdb, test_fn, NULL);
241 tdb_close(tdb);
242 }
243
244 /* count is < 0 means an error */
245 if (count < 0) {
246 printf("restoring %s\n", fname);
247 return backup_tdb(bak_name, fname, 0);
248 }
249
250 printf("%s : %d records\n", fname, count);
251
252 return 0;
253}
254
255/*
256 see if one file is newer than another
257*/
258static int file_newer(const char *fname1, const char *fname2)
259{
260 struct stat st1, st2;
261 if (stat(fname1, &st1) != 0) {
262 return 0;
263 }
264 if (stat(fname2, &st2) != 0) {
265 return 1;
266 }
267 return (st1.st_mtime > st2.st_mtime);
268}
269
270static void usage(void)
271{
272 printf("Usage: tdbbackup [options] <fname...>\n\n");
273 printf(" -h this help message\n");
274 printf(" -s suffix set the backup suffix\n");
275 printf(" -v verify mode (restore if corrupt)\n");
276 printf(" -n hashsize set the new hash size for the backup\n");
277}
278
279
280 int main(int argc, char *argv[])
281{
282 int i;
283 int ret = 0;
284 int c;
285 int verify = 0;
286 int hashsize = 0;
287 const char *suffix = ".bak";
288
289 log_ctx.log_fn = tdb_log;
290
291 while ((c = getopt(argc, argv, "vhs:n:")) != -1) {
292 switch (c) {
293 case 'h':
294 usage();
295 exit(0);
296 case 'v':
297 verify = 1;
298 break;
299 case 's':
300 suffix = optarg;
301 break;
302 case 'n':
303 hashsize = atoi(optarg);
304 break;
305 }
306 }
307
308 argc -= optind;
309 argv += optind;
310
311 if (argc < 1) {
312 usage();
313 exit(1);
314 }
315
316 for (i=0; i<argc; i++) {
317 const char *fname = argv[i];
318 char *bak_name;
319
320 bak_name = add_suffix(fname, suffix);
321
322 if (verify) {
323 if (verify_tdb(fname, bak_name) != 0) {
324 ret = 1;
325 }
326 } else {
327 if (file_newer(fname, bak_name) &&
328 backup_tdb(fname, bak_name, hashsize) != 0) {
329 ret = 1;
330 }
331 }
332
333 free(bak_name);
334 }
335
336 return ret;
337}
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