#!/sbin/runscript
# Copyright 1999-2004 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2
# $Id$

start() {
	ebegin "Starting p0f"
	# The 'tcp and tcp[13] & 2 = 2' requires at least syn set.
	# An alternative would be 'tcp and tcp[13] & 0x3f = 2', which
	# is syn and no other major flags (but ECN enabled packets are OK)
	if [ -z "$BpfFilter" ]; then
		BpfFilter='tcp and tcp[13] & 2 = 2'
	else
		BpfFilter="$BpfFilter and tcp and tcp[13] & 2 = 2"
	fi

	# The command in backticks returns all the local IP addresses on this machine.
	for OneIP in `/sbin/ifconfig 2>/dev/null | grep 'inet addr' | sed -e 's/.*addr://' -e 's/ .*//'` ; do
		BpfFilter="$BpfFilter and not src host $OneIP"
	done


	# Create a lock file.
	mkdir -p /var/lock/subsys
	touch /var/lock/subsys/p0f
	
	# Start up p0f and filter out all packets originating from any of this machines IP's.
	if [ -z "${P0FLOGFILE}" ]; then
		P0FLOGFILE="/var/log/p0f"
	fi
	einfo "Logfile: ${P0FLOGFILE}"
	start-stop-daemon --start --quiet --pidfile /var/run/p0f.pid --exec /usr/sbin/p0f -- -i "${P0FDEVICE}" \
		${P0FOPTIONS} -o "${P0FLOGFILE}" -d "${BpfFilter}" 2>/dev/null
	eend ${?}
}

stop() {
	ebegin "Stopping p0f"
	start-stop-daemon --stop --quiet --pidfile /var/run/p0f.pid
	rm -f /var/lock/subsys/p0f
	eend ${?}
}