Hmmm... Az OpenBSD PF -jéről jut eszembe egy részét? annak is portolták Windowsra a Core Force nevű biztonsági alkalmazásban. Különben ez az applikáció is egy saját köztes hálózati drivert applikál a windowsba.
http://force.coresecurity.com/index.php?module=articles&func=display&ca…
The firewall is a Windows port of OpenBSD’s Packet Filter (PF), which has been trimmed and tailored to make it suitable for desktop systems and to minimize complexity. There are two kernel-mode drivers that implement CORE FORCE's firewall, the core functionality of the firewall is performed by a miniport driver (croxy.sys) that uses the standard NDIS (Network Driver Interface Specification) API to wrap all communications between the network card drivers and the Operating System application layer. This driver intercepts all outgoing and incoming network packets, and because it's placed at the bottom of the networking stack, it additionally protects attacks to the Operating System's stack itself.
Üdv
Godot