added a tdb backup utility

when complete, this will be used to backup critical tdbs at samba
startup and possibly periodically while Samba is running so that if
tdb corruption is caused by a power failure Samba can restore from the
backup.
(This used to be commit f619330082712cab72ec2d2ab76d67b8e9f3194c)

2 files changed, 177 insertions, 1 deletions

diff --git a/source3/tdb/Makefile b/source3/tdb/Makefile
index b29bedf92c..3417759124 100644
--- a/source3/tdb/Makefile
+++ b/source3/tdb/Makefile
@@ -2,7 +2,7 @@
 # Makefile for tdb directory
 #
 
-CFLAGS = -DSTANDALONE -DTDB_DEBUG -O2 -g -DHAVE_MMAP=1
+CFLAGS = -DSTANDALONE -DTDB_DEBUG -pg -g -DHAVE_MMAP=1
 CC = gcc
 
 PROGS = tdbtest tdbtool tdbtorture
@@ -22,5 +22,8 @@ tdbtorture: tdbtorture.o $(TDB_OBJ)
 tdbdump: tdbdump.o $(TDB_OBJ)
 	$(CC) $(CFLAGS) -o tdbdump tdbdump.o $(TDB_OBJ)
 
+tdbbackup: tdbbackup.o $(TDB_OBJ)
+	$(CC) $(CFLAGS) -o tdbbackup tdbbackup.o $(TDB_OBJ)
+
 clean:
 	rm -f $(PROGS) *.o *~ *% core test.db test.tdb test.gdbm
diff --git a/source3/tdb/tdbbackup.c b/source3/tdb/tdbbackup.c
new file mode 100644
index 0000000000..9f2fbdab3c
--- /dev/null
+++ b/source3/tdb/tdbbackup.c
@@ -0,0 +1,173 @@
+/* 
+   Unix SMB/CIFS implementation.
+   low level tdb 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 2 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <time.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <ctype.h>
+#include "tdb.h"
+
+static int failed;
+
+static int copy_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
+{
+	TDB_CONTEXT *tdb_new = (TDB_CONTEXT *)state;
+
+	if (tdb_store(tdb_new, key, dbuf, TDB_INSERT) != 0) {
+		fprintf(stderr,"Failed to insert into %s\n", tdb_new->name);
+		failed = 1;
+		return 1;
+	}
+	return 0;
+}
+
+
+static int test_fn(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
+{
+	return 0;
+}
+
+/*
+  carefully backup a tdb to %s.bak, validating the contents and
+  only doing the backup if its OK
+*/
+static int backup_tdb(const char *fname)
+{
+	TDB_CONTEXT *tdb;
+	TDB_CONTEXT *tdb_new;
+	char *tmp_name = NULL;
+	char *bak_name = NULL;
+	struct stat st;
+	int count1, count2;
+
+	asprintf(&tmp_name, "%s.tmp", fname);
+
+	/* stat the old tdb to find its permissions */
+	if (stat(fname, &st) != 0) {
+		perror(fname);
+		return 1;
+	}
+
+	/* open the old tdb */
+	tdb = tdb_open(fname, 0, 0, O_RDWR, 0);
+	if (!tdb) {
+		printf("Failed to open %s\n", fname);
+		return 1;
+	}
+
+	/* create the new tdb */
+	unlink(tmp_name);
+	tdb_new = tdb_open(tmp_name, 0, TDB_DEFAULT, O_RDWR|O_CREAT|O_EXCL, 
+			   st.st_mode & 0777);
+	if (!tdb_new) {
+		perror(tmp_name);
+		free(tmp_name);
+		return 1;
+	}
+
+	/* lock the old tdb */
+	if (tdb_lockall(tdb) != 0) {
+		fprintf(stderr,"Failed to lock %s\n", fname);
+		tdb_close(tdb);
+		tdb_close(tdb_new);
+		unlink(tmp_name);
+		free(tmp_name);
+		return 1;
+	}
+
+	failed = 0;
+
+	/* traverse and copy */
+	count1 = tdb_traverse(tdb, copy_fn, (void *)tdb_new);
+	if (count1 < 0 || failed) {
+		fprintf(stderr,"failed to backup %s\n", fname);
+		tdb_close(tdb);
+		tdb_close(tdb_new);
+		unlink(tmp_name);
+		free(tmp_name);
+		return 1;
+	}
+
+	/* close the old tdb */
+	tdb_close(tdb);
+
+	/* close the new tdb and re-open read-only */
+	tdb_close(tdb_new);
+	tdb_new = tdb_open(tmp_name, 0, TDB_DEFAULT, O_RDONLY, 0);
+	if (!tdb_new) {
+		fprintf(stderr,"failed to reopen %s\n", tmp_name);
+		unlink(tmp_name);
+		perror(tmp_name);
+		free(tmp_name);
+		return 1;
+	}
+	
+	/* traverse the new tdb to confirm */
+	count2 = tdb_traverse(tdb_new, test_fn, 0);
+	if (count2 != count1) {
+		fprintf(stderr,"failed to backup %s\n", fname);
+		tdb_close(tdb_new);
+		unlink(tmp_name);
+		free(tmp_name);
+		return 1;
+	}
+
+	/* close the new tdb and rename it to .bak */
+	tdb_close(tdb_new);
+	asprintf(&bak_name, "%s.bak", fname);
+	unlink(bak_name);
+	if (rename(tmp_name, bak_name) != 0) {
+		perror(bak_name);
+		free(tmp_name);
+		free(bak_name);
+		return 1;
+	}
+
+	printf("%s : %d records\n", fname, count1);
+	free(tmp_name);
+	free(bak_name);
+
+	return 0;
+}
+
+ int main(int argc, char *argv[])
+{
+	int i;
+	int ret = 0;
+
+	if (argc < 2) {
+		printf("Usage: tdbbackup [options] <fname...>\n");
+		exit(1);
+	}
+
+	for (i=1; i<argc; i++) {
+		if (backup_tdb(argv[i]) != 0) ret = 1;
+	}
+
+	return ret;
+}