#!/bin/bash
#Copyright 2003 William Stearns <wstearns@pobox.com>
#Released under the GPL.

Me='lockdown'
MyVersion='0.4.0'
DefaultActions='DROP'

[ -r /etc/modwall/modwall.conf ] &&			. /etc/modwall/modwall.conf
[ -r /etc/modwall/$Me.conf ] &&				. /etc/modwall/$Me.conf
[ -r ${MWLibDir:-'/usr/lib/modwall/'}/modwalllib ] &&	. ${MWLibDir:-'/usr/lib/modwall/'}/modwalllib
if [ -z "$MWLibVer" ]; then
	echo 'It looks like modwalllib was not loaded, why?  Exiting' >&2
	exit 1
fi

for OneTask in $Tasks ; do
	case "$OneTask" in
	link)
		$IptablesBin -N $Me >/dev/null 2>&1
		$IptablesBin -I INPUT -i \! lo							-j $Me
		$IptablesBin -I FORWARD								-j $Me
		$IptablesBin -I OUTPUT								-j $Me
		;;
	unlink)
		$IptablesBin -D INPUT -i \! lo							-j $Me
		$IptablesBin -D FORWARD								-j $Me
		$IptablesBin -D OUTPUT								-j $Me
		$IptablesBin -X $Me >/dev/null 2>&1
		;;
	create)
		echo "Starting $Me" >&2
		FlushOrNewChain $Me
		LogAs='LockDown'	$Ipt -A $Me						$Tail
		;;
	destroy)
		echo "Stopping $Me" >&2
		DestroyChain $Me
		;;
	renamechain)
		TempChain="$Me-$RANDOM"
		echo "Replacing existing rules in $Me with new rules" >&2
		$IptablesBin -E $Me $TempChain
		;;
	replacelinks)
		if [ -z "$TempChain" ]; then
			echo "No temporary chain to relink in $Me replacelinks, replace operation incomplete." >&2
		elif ! $IptablesBin -L $Me -n >/dev/null 2>&1 ; then
			echo "No $Me chain in $Me, replace operation incomplete." >&2
		elif ! $IptablesBin -L $TempChain -n >/dev/null 2>&1 ; then
			echo "No $TempChain chain in $Me, replace operation incomplete." >&2
		elif [ "`$IptablesBin -L INPUT -n --line-numbers | grep $TempChain | wc -l`" -ne 1 ]; then
			echo "Too few/many references to $TempChain in INPUT in $Me replacelinks, replace operation incomplete." >&2
		elif [ "`$IptablesBin -L FORWARD -n --line-numbers | grep $TempChain | wc -l`" -ne 1 ]; then
			echo "Too few/many references to $TempChain in FORWARD in $Me replacelinks, replace operation incomplete." >&2
		elif [ "`$IptablesBin -L OUTPUT -n --line-numbers | grep $TempChain | wc -l`" -ne 1 ]; then
			echo "Too few/many references to $TempChain in OUTPUT in $Me replacelinks, replace operation incomplete." >&2
		else
			$IptablesBin -R INPUT `$IptablesBin -L INPUT -n --line-numbers | grep $TempChain | awk '{print $1}'` -i \! lo		-j $Me
			$IptablesBin -R FORWARD `$IptablesBin -L FORWARD -n --line-numbers | grep $TempChain | awk '{print $1}'`		-j $Me
			$IptablesBin -R OUTPUT `$IptablesBin -L OUTPUT -n --line-numbers | grep $TempChain | awk '{print $1}'`			-j $Me
			DestroyChain $TempChain
			unset TempChain
		fi
		;;
	status)
		if $IptablesBin -L $Me -n >/dev/null 2>&1 ; then
			echo "$Me created" >&2
		else
			echo "$Me destroyed" >&2
		fi
		;;
	version)
		echo "$Me $MyVersion, modwalllib $MWLibVer" >&2
		;;
	help)
		DefaultHelp
		cat <<EOTEXT >&2
	The $Me module completely blocks all traffic going in, out or
through the machine.  It is designed to go at the top of the ruleset,
blocking all traffic while the network interfaces, routing tables, and
firewall rules are being set up.  Once those are all in place, the
lockdown module can be shut down, allowing traffic to flow normally.
EOTEXT
		;;
	*)
		echo "Unknown action $Action in $Me, no action taken." >&2
		;;
	esac
done