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

#ZZZZ Check Me and MyVersion
Me='snort-multimedia'
MyVersion='20031125'
#DefaultActions=''

[ -r /etc/firebricks/firebricks.conf ] &&			. /etc/firebricks/firebricks.conf
[ -r /etc/firebricks/$Me.conf ] &&				. /etc/firebricks/$Me.conf
[ -r ${FBLibDir:-'/usr/lib/firebricks/'}/firebrickslib ] &&	. ${FBLibDir:-'/usr/lib/firebricks/'}/firebrickslib
if [ -z "$FBLibVer" ]; then
	echo 'It looks like firebrickslib 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
#ZZZZ try to restrict the following three to only send down what the chain needs to inspect.
		$IptablesBin $AppIn INPUT -i \! lo						-j $Me
		$IptablesBin $AppIn FORWARD							-j $Me
		$IptablesBin $AppIn OUTPUT							-j $Me
		;;
	unlink)
#ZZZZ Make the same changes as above (such as "-p tcp"), but if you cut and paste, note "$AppIn" is now "-D"
		$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="SID1436"		$Ipt -A $Me -p tcp --dport 80 -m string --string '"User-Agent: Quicktime"'	$Tail	# '"MULTIMEDIA Quicktime User Agent access"' classtype:policy-violation sid:1436
		LogAs="SID1437"		$Ipt -A $Me -p tcp --sport 80 -m string --string '"Content-type: audio/x-ms-wma"' --string '""'	$Tail	# '"MULTIMEDIA Windows Media audio download"' classtype:policy-violation sid:1437
		LogAs="SID1438"		$Ipt -A $Me -p tcp --sport 80 -m string --string '"Content-type: video/x-ms-asf"' --string '""'	$Tail	# '"MULTIMEDIA Windows Media Video download"' classtype:policy-violation sid:1438
		LogAs="SID1439"		$Ipt -A $Me -p tcp --sport 80 -m string --string '"Content-type: audio/x-scpls"' --string '""'	$Tail	# '"MULTIMEDIA Shoutcast playlist redirection"' classtype:policy-violation sid:1439
		LogAs="SID1440"		$Ipt -A $Me -p tcp --sport 80 -m string --string '"Content-type: audio/x-mpegurl"' --string '""'	$Tail	# '"MULTIMEDIA Icecast playlist redirection"' classtype:policy-violation sid:1440
		LogAs="SID1428"		$Ipt -A $Me -p tcp -d 64.245.58.0/23 -m state --state ESTABLISHED -m string --string '"E_"'	$Tail	# '"MULTIMEDIA audio galaxy keepalive"' classtype:misc-activity sid:1428


		;;
	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
#ZZZZ Place the same criteria you used in link/unlink above in the following three lines.
#ZZZZ Criteria should go just in front of "-j $Me"
			$IptablesBin -R INPUT `$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, firebrickslib $FBLibVer" >&2
		;;
	help)
		DefaultHelp
#ZZZZ Please change the text to appropriate help text for this module.  You should
#ZZZZ cover what the module does, if it's generally safe to use, and under what
#ZZZZ conditions it should not be used.  Please replace the lines between the two
#ZZZZ EOTEXT lines with your own.
		cat <<EOTEXT >&2
	The $Me module puts in some blocks for fragmented icmp packets
(illegal) and address mask and timestamp requests and replies.  At best,
these are uncommon and are used in network mapping.  These rules should
be safe to use on any network.
EOTEXT
		;;
	*)
		echo "Unknown action $Action in $Me, no action taken." >&2
		;;
	esac
done