fwsnort - iptables Intrusion Detection with String Matching and Snort Rules

fwsnort parses the rules files included in the SNORT ® intrusion detection system and builds an equivalent iptables ruleset for as many rules as possible. fwsnort utilizes the iptables string match module (together with a custom patch that adds a --hex-string option to the iptables user space code which is now integrated with iptables) to detect application level attacks.

via cipherdyne.org