global: Add SPDX tags and copyright header

Mathias should probably add his copyright headers to each file too.

1 files changed, 5 insertions, 0 deletions

diff --git a/tun.go b/tun.go
index 318772a..ec3ab47 100644
--- a/tun.go
+++ b/tun.go
@@ -1,3 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (C) 2017-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
 package main
 
 import (