bpf: Dual-license the code as GPL-2.0 OR BSD-2-Clause (update text)

Relicense most code under the "bpf/" directory as dual-licensed under
the terms of both the GPL 2.0 license and the 2-Clause BSD license.

Signed-off-by: Kornilios Kourtis <[email protected]>

README.md

@@ -6,6 +6,8 @@
 </a>
 
 [![License](https://img.shields.io/badge/License-Apache_2.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
+[![License](https://img.shields.io/badge/license-BSD-blue.svg)](https://opensource.org/license/bsd-2-clause/)
+[![License](https://img.shields.io/badge/license-GPL-blue.svg)](https://opensource.org/license/gpl-2-0/)
 
 ---
 
@@ -70,4 +72,3 @@ For getting started with local development, you can refer to the
 [Contribution Guide](https://tetragon.cilium.io/docs/contribution-guide/). If
 you plan to submit a PR, please ["sign-off"](https://tetragon.cilium.io/docs/contribution-guide/developer-certificate-of-origin/)
 your commits.
-

bpf/COPYING

@@ -0,0 +1,7 @@
+The code under this directory, unless otherwise specified, is dual-licensed:
+you can use it either under the terms of the GPL v2.0 (only) or the 2-Clause
+BSD license, at your option. Note that this dual licensing only applies to the
+files under this directory, and not this project as a whole.
+
+See the files LICENSE.GPL-2.0 and LICENSE.BSD-2-Clause in this directory for
+more details about the terms of these licenses.

bpf/LICENSE.BSD-2-Clause

@@ -0,0 +1,23 @@
+Copyright Authors of Cilium. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.