Ipfw and dummynet improvements


The microinstruction-based architecture of ipfw stimulated the addition of many new operations and features over the last few years. Individually, each of these additions is a small piece of code, but the overall result is that ipfw source code (both kernel and userland) has grown significantly, leading to very large source files and functions that are not in line with good engineering practices.

In this project I plan to revise the ipfw and dummynet code with following goals:

Project Details

The aim of this project is to revise and improve the ipfw and dummynet subsystems as explained in the summary.

The motivation for this project comes from some work I am doing with my advisor, Prof. Luigi Rizzo, in which we are porting ipfw and dummynet to Linux and Windows.

The Linux port, which is well on its way, pointed out some of the issues in the ipfw code, including the exceedingly large size of files and functions, the namespace pollution resulting from having most data structures defined in a single header, and the potential performance problems due to coarse locking and inefficient kernel/userland interface. The userland code has problems as well, also related to poor error handling in presence of malformed input.

In the work on the Linux port we already did some cleanup of the userland code, which was committed to both HEAD and RELENG_7. Also, I have gained a lot of familiarity with the kernel part of the code.


SOC2009MartaCarbone (last edited 2020-06-20T07:19:02+0000 by KubilayKocak)