diff --git a/src/util/rfkill.cpp b/src/util/rfkill.cpp
index a4f9c71..2d5ad7f 100644
--- a/src/util/rfkill.cpp
+++ b/src/util/rfkill.cpp
@@ -1,3 +1,21 @@
+/* https://git.kernel.org/pub/scm/linux/kernel/git/jberg/rfkill.git/
+ *
+ * Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
+ * Copyright 2009 Marcel Holtmann <marcel@holtmann.org>
+ * Copyright 2009 Tim Gardner <tim.gardner@canonical.com>
+ * 
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
 #include "util/rfkill.hpp"
 #include <linux/rfkill.h>
 #include <unistd.h>