1 files changed, 84 insertions, 0 deletions
diff --git a/cmd/ext4/feature_flag.go b/cmd/ext4/feature_flag.go
new file mode 100644
index 0000000..58b3669
--- /dev/null
+++ b/cmd/ext4/feature_flag.go
@@ -0,0 +1,84 @@
+// +build linux,cgo
+
+/*
+ * feature_flag.go - Changes encryption flag for an ext4 filesystem.
+ *
+ * Copyright 2017 Google Inc.
+ * Author: Joe Richey (joerichey@google.com)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not
+ * use this file except in compliance with the License. You may obtain a copy of
+ * the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package main
+
+/*
+#cgo LDFLAGS: -lext2fs
+#include <ext2fs/ext2_fs.h>
+#include <ext2fs/ext2fs.h>
+
+#include <stdlib.h>
+*/
+import "C"
+import (
+	"fmt"
+
+	"github.com/google/fscrypt/filesystem"
+)
+
+// Ext4Filesystem wraps the C structures returned from libext2fs.
+type Ext4Filesystem struct {
+	ptr     C.ext2_filsys
+	mounted bool
+	retVal  C.errcode_t
+}
+
+// NewExt4Filesystem creates a new Ext4Filesystem from a mountpoint path. Fail
+// if the path is not the mountpoint of an ext4 filesystem or cannot be opened.
+func NewExt4Filesystem(mount *filesystem.Mount) (*Ext4Filesystem, error) {
+	if mount.Filesystem != "ext4" {
+		err := fmt.Errorf("%q is not an ext4 filesystem (type %q)", mount.Path, mount.Filesystem)
+		return nil, err
+	}
+	if mount.Device == "" {
+		err := fmt.Errorf("underlying device for %q is invalid", mount.Filesystem)
+		return nil, err
+	}
+	return nil, nil
+}
+
+// HasValidBlockSize returns true if the filesystem has the same block size as
+// the system's page size.
+func (fs *Ext4Filesystem) HasValidBlockSize() bool {
+	return true
+}
+
+// IsEncryptionEnabled return true if the "encrypt" feature flag is set.
+func (fs *Ext4Filesystem) IsEncryptionEnabled() bool {
+	return C.ext2fs_has_feature_encrypt(fs.ptr.super) != 0
+}
+
+// EnableEncryption sets the "encrypt" feature flag and writes the appropriate
+// information in the superblock to allow filesystem encryption.
+func (fs *Ext4Filesystem) EnableEncryption() error {
+	return nil
+}
+
+// DisableEncryption removes the "encrypt" feature flag.
+func (fs *Ext4Filesystem) DisableEncryption() error {
+	return nil
+}
+
+// Close safely closes, frees, and runs cleanup f9r the filesystem.
+func (fs *Ext4Filesystem) Close() error {
+	return nil
+}