1 files changed, 66 insertions, 0 deletions
diff --git a/src/orchestrator/utils/utils.go b/src/orchestrator/utils/utils.go
new file mode 100644
index 00000000..44cf5120
--- /dev/null
+++ b/src/orchestrator/utils/utils.go
@@ -0,0 +1,66 @@
+/*
+ * Copyright 2020 Intel Corporation, 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 utils
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"io"
+
+	pkgerrors "github.com/pkg/errors"
+)
+
+func IsTarGz(r io.Reader) error {
+	//Check if it is a valid gz
+	gzf, err := gzip.NewReader(r)
+	if err != nil {
+		return pkgerrors.Wrap(err, "Invalid gzip format")
+	}
+
+	//Check if it is a valid tar file
+	//Unfortunately this can only be done by inspecting all the tar contents
+	tarR := tar.NewReader(gzf)
+	first := true
+
+	for true {
+		header, err := tarR.Next()
+
+		if err == io.EOF {
+			//Check if we have just a gzip file without a tar archive inside
+			if first {
+				return pkgerrors.New("Empty or non-existant Tar file found")
+			}
+			//End of archive
+			break
+		}
+
+		if err != nil {
+			return pkgerrors.Errorf("Error reading tar file %s", err.Error())
+		}
+
+		//Check if files are of type directory and regular file
+		if header.Typeflag != tar.TypeDir &&
+			header.Typeflag != tar.TypeReg {
+			return pkgerrors.Errorf("Unknown header in tar %s, %s",
+				header.Name, string(header.Typeflag))
+		}
+
+		first = false
+	}
+
+	return nil
+}