docs: declare GPL3 license
refs #2672
Change-Id: I93e0cb6b7ff907d3f05d21aae2d21009efd3e2f0
diff --git a/tools/ping/ndn-ping-server.cpp b/tools/ping/ndn-ping-server.cpp
index 684891c..d508e6c 100644
--- a/tools/ping/ndn-ping-server.cpp
+++ b/tools/ping/ndn-ping-server.cpp
@@ -1,4 +1,21 @@
-/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015, Arizona Board of Regents.
+ *
+ * This file is part of ndn-tools (Named Data Networking Essential Tools).
+ * See AUTHORS.md for complete list of ndn-tools authors and contributors.
+ *
+ * ndn-tools is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-tools is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndn-tools, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ */
/**
* Copyright (C) 2014 Arizona Board of Regents
*
diff --git a/tools/ping/ndn-ping.cpp b/tools/ping/ndn-ping.cpp
index 4abfcec..11591a6 100644
--- a/tools/ping/ndn-ping.cpp
+++ b/tools/ping/ndn-ping.cpp
@@ -1,4 +1,21 @@
-/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil -*- */
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2014-2015, Arizona Board of Regents.
+ *
+ * This file is part of ndn-tools (Named Data Networking Essential Tools).
+ * See AUTHORS.md for complete list of ndn-tools authors and contributors.
+ *
+ * ndn-tools is free software: you can redistribute it and/or modify it under the terms
+ * of the GNU General Public License as published by the Free Software Foundation,
+ * either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-tools is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+ * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+ * PURPOSE. See the GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * ndn-tools, e.g., in COPYING.md file. If not, see <http://www.gnu.org/licenses/>.
+ */
/**
* Copyright (C) 2014 Arizona Board of Regents
*