Tom Eastep 2012 Thomas M. Eastep Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover, and with no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.

This document provides an overview of Shorewall internals. It is intended to ease the task of approaching the Shorewall code base by providing a roadmap of what you will find there.

Shorewall was originally written entirely in Bourne Shell. The chief advantage of this approach was that virtually any platform supports the shell, including small embedded environments. The