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Diffstat (limited to 'lib/ntdb/tools/ntdbbackup.c')
| -rw-r--r-- | lib/ntdb/tools/ntdbbackup.c | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/lib/ntdb/tools/ntdbbackup.c b/lib/ntdb/tools/ntdbbackup.c new file mode 100644 index 0000000000..a76f18491b --- /dev/null +++ b/lib/ntdb/tools/ntdbbackup.c @@ -0,0 +1,340 @@ +/* + Unix SMB/CIFS implementation. + low level ntdb 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 3 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, see <http://www.gnu.org/licenses/>. +*/ + +/* + + This program is meant for backup/restore of ntdb databases. Typical usage would be: + tdbbackup *.ntdb + when Samba shuts down cleanly, which will make a backup of all the local databases + to *.bak files. Then on Samba startup you would use: + tdbbackup -v *.ntdb + and this will check the databases for corruption and if corruption is detected then + the backup will be restored. + + You may also like to do a backup on a regular basis while Samba is + running, perhaps using cron. + + The reason this program is needed is to cope with power failures + while Samba is running. A power failure could lead to database + corruption and Samba will then not start correctly. + + Note that many of the databases in Samba are transient and thus + don't need to be backed up, so you can optimise the above a little + by only running the backup on the critical databases. + + */ + +#include "config.h" +#include "ntdb.h" +#include "system/filesys.h" + +#ifdef HAVE_GETOPT_H +#include <getopt.h> +#endif + +static int failed; + +static void ntdb_log(struct ntdb_context *ntdb, + enum ntdb_log_level level, + enum NTDB_ERROR ecode, + const char *message, + void *data) +{ + fprintf(stderr, "%s:%s\n", ntdb_errorstr(ecode), message); +} + +static char *add_suffix(const char *name, const char *suffix) +{ + char *ret; + int len = strlen(name) + strlen(suffix) + 1; + ret = (char *)malloc(len); + if (!ret) { + fprintf(stderr,"Out of memory!\n"); + exit(1); + } + snprintf(ret, len, "%s%s", name, suffix); + return ret; +} + +static int copy_fn(struct ntdb_context *ntdb, NTDB_DATA key, NTDB_DATA dbuf, void *state) +{ + struct ntdb_context *ntdb_new = (struct ntdb_context *)state; + enum NTDB_ERROR err; + + err = ntdb_store(ntdb_new, key, dbuf, NTDB_INSERT); + if (err) { + fprintf(stderr,"Failed to insert into %s: %s\n", + ntdb_name(ntdb_new), ntdb_errorstr(err)); + failed = 1; + return 1; + } + return 0; +} + + +static int test_fn(struct ntdb_context *ntdb, NTDB_DATA key, NTDB_DATA dbuf, void *state) +{ + return 0; +} + +/* + carefully backup a ntdb, validating the contents and + only doing the backup if its OK + this function is also used for restore +*/ +static int backup_ntdb(const char *old_name, const char *new_name) +{ + struct ntdb_context *ntdb; + struct ntdb_context *ntdb_new; + char *tmp_name; + struct stat st; + int count1, count2; + enum NTDB_ERROR err; + union ntdb_attribute log_attr; + + tmp_name = add_suffix(new_name, ".tmp"); + + /* stat the old ntdb to find its permissions */ + if (stat(old_name, &st) != 0) { + perror(old_name); + free(tmp_name); + return 1; + } + + log_attr.base.attr = NTDB_ATTRIBUTE_LOG; + log_attr.base.next = NULL; + log_attr.log.fn = ntdb_log; + + /* open the old ntdb */ + ntdb = ntdb_open(old_name, NTDB_DEFAULT, O_RDWR, 0, &log_attr); + if (!ntdb) { + printf("Failed to open %s\n", old_name); + free(tmp_name); + return 1; + } + + unlink(tmp_name); + ntdb_new = ntdb_open(tmp_name, NTDB_DEFAULT, + O_RDWR|O_CREAT|O_EXCL, st.st_mode & 0777, + &log_attr); + if (!ntdb_new) { + perror(tmp_name); + free(tmp_name); + return 1; + } + + err = ntdb_transaction_start(ntdb); + if (err) { + fprintf(stderr, "Failed to start transaction on old ntdb: %s\n", + ntdb_errorstr(err)); + ntdb_close(ntdb); + ntdb_close(ntdb_new); + unlink(tmp_name); + free(tmp_name); + return 1; + } + + /* lock the backup ntdb so that nobody else can change it */ + err = ntdb_lockall(ntdb_new); + if (err) { + fprintf(stderr, "Failed to lock backup ntdb: %s\n", + ntdb_errorstr(err)); + ntdb_close(ntdb); + ntdb_close(ntdb_new); + unlink(tmp_name); + free(tmp_name); + return 1; + } + + failed = 0; + + /* traverse and copy */ + count1 = ntdb_traverse(ntdb, copy_fn, (void *)ntdb_new); + if (count1 < 0 || failed) { + fprintf(stderr,"failed to copy %s\n", old_name); + ntdb_close(ntdb); + ntdb_close(ntdb_new); + unlink(tmp_name); + free(tmp_name); + return 1; + } + + /* close the old ntdb */ + ntdb_close(ntdb); + + /* copy done, unlock the backup ntdb */ + ntdb_unlockall(ntdb_new); + +#ifdef HAVE_FDATASYNC + if (fdatasync(ntdb_fd(ntdb_new)) != 0) { +#else + if (fsync(ntdb_fd(ntdb_new)) != 0) { +#endif + /* not fatal */ + fprintf(stderr, "failed to fsync backup file\n"); + } + + /* close the new ntdb and re-open read-only */ + ntdb_close(ntdb_new); + + /* we don't need the hash attr any more */ + log_attr.base.next = NULL; + + ntdb_new = ntdb_open(tmp_name, NTDB_DEFAULT, O_RDONLY, 0, &log_attr); + if (!ntdb_new) { + fprintf(stderr,"failed to reopen %s\n", tmp_name); + unlink(tmp_name); + perror(tmp_name); + free(tmp_name); + return 1; + } + + /* traverse the new ntdb to confirm */ + count2 = ntdb_traverse(ntdb_new, test_fn, NULL); + if (count2 != count1) { + fprintf(stderr,"failed to copy %s\n", old_name); + ntdb_close(ntdb_new); + unlink(tmp_name); + free(tmp_name); + return 1; + } + + /* close the new ntdb and rename it to .bak */ + ntdb_close(ntdb_new); + if (rename(tmp_name, new_name) != 0) { + perror(new_name); + free(tmp_name); + return 1; + } + + free(tmp_name); + + return 0; +} + +/* + verify a ntdb and if it is corrupt then restore from *.bak +*/ +static int verify_ntdb(const char *fname, const char *bak_name) +{ + struct ntdb_context *ntdb; + int count = -1; + union ntdb_attribute log_attr; + + log_attr.base.attr = NTDB_ATTRIBUTE_LOG; + log_attr.base.next = NULL; + log_attr.log.fn = ntdb_log; + + /* open the ntdb */ + ntdb = ntdb_open(fname, NTDB_DEFAULT, O_RDONLY, 0, &log_attr); + + /* traverse the ntdb, then close it */ + if (ntdb) { + count = ntdb_traverse(ntdb, test_fn, NULL); + ntdb_close(ntdb); + } + + /* count is < 0 means an error */ + if (count < 0) { + printf("restoring %s\n", fname); + return backup_ntdb(bak_name, fname); + } + + printf("%s : %d records\n", fname, count); + + return 0; +} + +/* + see if one file is newer than another +*/ +static int file_newer(const char *fname1, const char *fname2) +{ + struct stat st1, st2; + if (stat(fname1, &st1) != 0) { + return 0; + } + if (stat(fname2, &st2) != 0) { + return 1; + } + return (st1.st_mtime > st2.st_mtime); +} + +static void usage(void) +{ + printf("Usage: ntdbbackup [options] <fname...>\n\n"); + printf(" -h this help message\n"); + printf(" -v verify mode (restore if corrupt)\n"); + printf(" -s suffix set the backup suffix\n"); + printf(" -v verify mode (restore if corrupt)\n"); +} + + + int main(int argc, char *argv[]) +{ + int i; + int ret = 0; + int c; + int verify = 0; + const char *suffix = ".bak"; + + while ((c = getopt(argc, argv, "vhs:")) != -1) { + switch (c) { + case 'h': + usage(); + exit(0); + case 'v': + verify = 1; + break; + case 's': + suffix = optarg; + break; + } + } + + argc -= optind; + argv += optind; + + if (argc < 1) { + usage(); + exit(1); + } + + for (i=0; i<argc; i++) { + const char *fname = argv[i]; + char *bak_name; + + bak_name = add_suffix(fname, suffix); + + if (verify) { + if (verify_ntdb(fname, bak_name) != 0) { + ret = 1; + } + } else { + if (file_newer(fname, bak_name) && + backup_ntdb(fname, bak_name) != 0) { + ret = 1; + } + } + + free(bak_name); + } + + return ret; +} |