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

Me='shundst'
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 $AppIn INPUT -i \! lo						-j $Me
		$IptablesBin $AppIn FORWARD							-j $Me
		$IptablesBin $AppIn OUTPUT -o \! lo						-j $Me
		;;
	unlink)
		#$IptablesBin -D INPUT -i \! lo							-j $Me
		$IptablesBin -D FORWARD								-j $Me
		$IptablesBin -D OUTPUT -o \! lo							-j $Me
		$IptablesBin -X $Me >/dev/null 2>&1
		;;
	create)
		echo "Starting $Me" >&2
		FlushOrNewChain $Me

		for OneIP in `/sbin/ifconfig 2>/dev/null | grep 'inet addr:' | sed -e 's/.*inet addr://' | awk '{print $1}' | grep -v '0\.0\.0\.0'` ; do
			LogAs='ShunLocalIP'	$Ipt -A $Me -d $OneIP				$Tail
		done

		for ShunFile in $MWData/shun* ; do
			if [ -f "$ShunFile" ]; then
				cat "$ShunFile" | sed -e 's/#.*//' | while read ShunNet ; do
					LogAs='ShunIP'	$Ipt -A $Me -d $ShunNet			$Tail
				done
			fi
		done
		;;
	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}'` -o \! lo	-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 places permanent bans on destination IP addresses
or networks listed in any files whose names start with $MWData/shun .
EOTEXT
		;;
	*)
		echo "Unknown action $Action in $Me, no action taken." >&2
		;;
	esac
done