fs: Add proper volume and path validation.

fs-utils.go

@@ -0,0 +1,56 @@
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * 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
+
+import (
+	"regexp"
+	"unicode/utf8"
+)
+
+// validVolname regexp.
+var validVolname = regexp.MustCompile(`^.{3,63}$`)
+
+// isValidVolname verifies a volname name in accordance with object
+// layer requirements.
+func isValidVolname(volname string) bool {
+	return validVolname.MatchString(volname)
+}
+
+// Keeping this as lower bound value supporting Linux, Darwin and Windows operating systems.
+const pathMax = 4096
+
+// isValidPath verifies if a path name is in accordance with FS limitations.
+func isValidPath(path string) bool {
+	// TODO: Make this FSType or Operating system specific.
+	if len(path) > pathMax || len(path) == 0 {
+		return false
+	}
+	if !utf8.ValidString(path) {
+		return false
+	}
+	return true
+}
+
+// isValidPrefix verifies where the prefix is a valid path.
+func isValidPrefix(prefix string) bool {
+	// Prefix can be empty.
+	if prefix == "" {
+		return true
+	}
+	// Verify if prefix is a valid path.
+	return isValidPath(prefix)
+}