--- ../samba-orig/source/tdb/tdb.h	Wed Feb  5 16:25:48 2003
+++ source/tdb/tdb.h	Sun Feb 15 08:28:24 2004
@@ -96,6 +96,7 @@
 	ino_t inode;	/* uniquely identifies this tdb */
 	void (*log_fn)(struct tdb_context *tdb, int level, const char *, ...); /* logging function */
 	int open_flags; /* flags used in the open - needed by reopen */
+	int fd_active_lock;
 } TDB_CONTEXT;
 
 typedef int (*tdb_traverse_func)(TDB_CONTEXT *, TDB_DATA, TDB_DATA, void *);
--- ../samba-orig/source/tdb/tdb.c	Thu Feb 12 21:07:18 2004
+++ source/tdb/tdb.c	Sun Feb 15 10:06:33 2004
@@ -69,6 +69,7 @@
 /* lock offsets */
 #define GLOBAL_LOCK 0
 #define ACTIVE_LOCK 4
+#define USE_ACTIVE_LOCK 1
 
 #ifndef MAP_FILE
 #define MAP_FILE 0
@@ -182,8 +183,8 @@
 
    On error, errno is also set so that errors are passed back properly
    through tdb_open(). */
-static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, 
-		      int rw_type, int lck_type, int probe)
+static int tdb_brlock_fd(TDB_CONTEXT *tdb, int fd, tdb_off offset, 
+			 int rw_type, int lck_type, int probe)
 {
 	struct flock fl;
 	int ret;
@@ -202,7 +203,7 @@
 	fl.l_pid = 0;
 
 	do {
-		ret = fcntl(tdb->fd,lck_type,&fl);
+		ret = fcntl(fd,lck_type,&fl);
 		if (ret == -1 && errno == EINTR && palarm_fired && *palarm_fired)
 			break;
 	} while (ret == -1 && errno == EINTR);
@@ -210,7 +211,7 @@
 	if (ret == -1) {
 		if (!probe && lck_type != F_SETLK) {
 			TDB_LOG((tdb, 5,"tdb_brlock failed (fd=%d) at offset %d rw_type=%d lck_type=%d\n", 
-				 tdb->fd, offset, rw_type, lck_type));
+				 fd, offset, rw_type, lck_type));
 		}
 		/* Was it an alarm timeout ? */
 		if (errno == EINTR && palarm_fired && *palarm_fired)
@@ -222,6 +223,13 @@
 	return 0;
 }
 
+
+static int tdb_brlock(TDB_CONTEXT *tdb, tdb_off offset, 
+		      int rw_type, int lck_type, int probe)
+{
+	return tdb_brlock_fd(tdb, tdb->fd, offset, rw_type, lck_type, probe);
+}
+
 /* lock a list in the database. list -1 is the alloc list */
 static int tdb_lock(TDB_CONTEXT *tdb, int list, int ltype)
 {
@@ -291,6 +299,87 @@
 	return ret;
 }
 
+
+#define OLD_ACTIVE_LOCK_CODE 0
+
+#if OLD_ACTIVE_LOCK_CODE
+static int tdb_active_lock_exclusive(TDB_CONTEXT *tdb)
+{
+	return tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0);
+}
+
+static int tdb_active_lock_unlock(TDB_CONTEXT *tdb)
+{
+	return tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0);
+}
+
+static int tdb_active_lock_shared(TDB_CONTEXT *tdb)
+{
+	return tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0);
+}
+#else
+
+
+static int tdb_active_lock_create(TDB_CONTEXT *tdb)
+{
+	char *name = NULL;
+
+	if (tdb->fd_active_lock != -1) {
+		return tdb->fd_active_lock;
+	}
+
+	asprintf(&name, "%s.lck", tdb->name);
+	if (!name) {
+		TDB_LOG((tdb, 0, "Failed to allocate active lock name\n"));
+		errno = ENOMEM;
+		return -1;
+	}
+	tdb->fd_active_lock = open(name, O_CREAT|O_RDWR, 0600);
+	free(name);
+	if (tdb->fd_active_lock == -1) {
+		TDB_LOG((tdb, 0, "Failed to create active lock file\n"));
+		return -1;
+	}
+	return tdb->fd_active_lock;
+}
+
+static int tdb_active_lock_exclusive(TDB_CONTEXT *tdb)
+{
+	int fd = tdb_active_lock_create(tdb);
+	if (fd == -1) {
+		return -1;
+	}
+
+	return tdb_brlock_fd(tdb, fd, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0);
+}
+
+static int tdb_active_lock_unlock(TDB_CONTEXT *tdb)
+{
+	int fd = tdb_active_lock_create(tdb);
+	if (fd == -1) {
+		return -1;
+	}
+
+	return tdb_brlock_fd(tdb, fd, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0);
+}
+
+static int tdb_active_lock_shared(TDB_CONTEXT *tdb)
+{
+	int fd = tdb_active_lock_create(tdb);
+	if (fd == -1) {
+		return -1;
+	}
+
+	/* we also try to get an exclusive lock on the old active lock
+	   range on the main tdb file. This greatly reduces the chance
+	   of old tools from destroying our database */
+	tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0);
+
+	return tdb_brlock_fd(tdb, fd, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0);
+}
+
+#endif
+
 /* This is based on the hash algorithm from gdbm */
 static u32 tdb_hash(TDB_DATA *key)
 {
@@ -1679,6 +1768,7 @@
 		goto fail;
 	}
 	tdb->fd = -1;
+	tdb->fd_active_lock = -1;
 	tdb->name = NULL;
 	tdb->map_ptr = NULL;
 	tdb->lockedkeys = NULL;
@@ -1726,8 +1816,14 @@
 		goto fail;	/* errno set by tdb_brlock */
 	}
 
+	if (!(tdb->name = (char *)strdup(name))) {
+		errno = ENOMEM;
+		goto fail;
+	}
+
 	/* we need to zero database if we are the only one with it open */
-	if ((locked = (tdb_brlock(tdb, ACTIVE_LOCK, F_WRLCK, F_SETLK, 0) == 0))
+#if USE_ACTIVE_LOCK
+	if ((locked = (tdb_active_lock_exclusive(tdb) == 0))
 	    && (tdb_flags & TDB_CLEAR_IF_FIRST)) {
 		open_flags |= O_CREAT;
 		if (ftruncate(tdb->fd, 0) == -1) {
@@ -1737,15 +1833,17 @@
 			goto fail; /* errno set by ftruncate */
 		}
 	}
+#endif
 
 	if (read(tdb->fd, &tdb->header, sizeof(tdb->header)) != sizeof(tdb->header)
 	    || strcmp(tdb->header.magic_food, TDB_MAGIC_FOOD) != 0
-	    || tdb->header.version != TDB_VERSION
-	    || (tdb->header.hash_size != hash_size
+	    || (tdb->header.version != TDB_VERSION 
 		&& !(rev = (tdb->header.version==TDB_BYTEREV(TDB_VERSION))))) {
 		/* its not a valid database - possibly initialise it */
 		if (!(open_flags & O_CREAT) || tdb_new_database(tdb, hash_size) == -1) {
 			errno = EIO; /* ie bad format or something */
+			TDB_LOG((tdb, 0, "Failed to open hash=%d tdbhash=%d\n",
+				 hash_size, tdb->header.hash_size));
 			goto fail;
 		}
 		rev = (tdb->flags & TDB_CONVERT);
@@ -1772,11 +1870,6 @@
 		goto fail;
 	}
 
-	if (!(tdb->name = (char *)strdup(name))) {
-		errno = ENOMEM;
-		goto fail;
-	}
-
 	tdb->map_size = st.st_size;
 	tdb->device = st.st_dev;
 	tdb->inode = st.st_ino;
@@ -1796,16 +1889,21 @@
 				"failed to clear spinlock\n"));
 				goto fail;
 			}
-		if (tdb_brlock(tdb, ACTIVE_LOCK, F_UNLCK, F_SETLK, 0) == -1) {
+#if USE_ACTIVE_LOCK
+		if (tdb_active_lock_unlock(tdb) == -1) {
 			TDB_LOG((tdb, 0, "tdb_open_ex: "
-				 "failed to take ACTIVE_LOCK on %s: %s\n",
+				 "failed to release ACTIVE_LOCK on %s: %s\n",
 				 name, strerror(errno)));
 			goto fail;
 		}
+#endif
 	}
+
+#if USE_ACTIVE_LOCK
 	/* leave this lock in place to indicate it's in use */
-	if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)
+	if (tdb_active_lock_shared(tdb) == -1)
 		goto fail;
+#endif
 
  internal:
 	/* Internal (memory-only) databases skip all the code above to
@@ -1836,6 +1934,9 @@
 	if (tdb->fd != -1)
 		if (close(tdb->fd) != 0)
 			TDB_LOG((tdb, 5, "tdb_open_ex: failed to close tdb->fd on error!\n"));
+	if (tdb->fd_active_lock != -1)
+		if (close(tdb->fd_active_lock) != 0)
+			TDB_LOG((tdb, 5, "tdb_open_ex: failed to close tdb->fd_active_lock on error!\n"));
 	SAFE_FREE(tdb->locked);
 	SAFE_FREE(tdb);
 	errno = save_errno;
@@ -1861,6 +1962,8 @@
 	SAFE_FREE(tdb->name);
 	if (tdb->fd != -1)
 		ret = close(tdb->fd);
+	if (tdb->fd_active_lock != -1)
+		ret = close(tdb->fd_active_lock);
 	SAFE_FREE(tdb->locked);
 	SAFE_FREE(tdb->lockedkeys);
 
@@ -2026,6 +2129,9 @@
 	}
 	if (close(tdb->fd) != 0)
 		TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n"));
+	if (close(tdb->fd_active_lock) != 0)
+		TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd_active_lock failed!\n"));
+	tdb->fd_active_lock = -1;
 	tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0);
 	if (tdb->fd == -1) {
 		TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno)));
@@ -2040,10 +2146,12 @@
 		goto fail;
 	}
 	tdb_mmap(tdb);
-	if (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1) {
+#if USE_ACTIVE_LOCK
+	if (tdb_active_lock_shared(tdb) == -1) {
 		TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n"));
 		goto fail;
 	}
+#endif
 
 	END_PROFILE(tdb_reopen);
 	return 0;