Add 'all' option for mss clamp

CHANGELOG

@@ -1,6 +1,8 @@
 2.1 Alpha 2 - 03/15/2015
 	- Unset variables in loops to make sure theres no leakage of
 		variables into the next run of the loop
+	04/09/2015
+	- Allow use of 'all' in MSS rules to match all forwarding/out traffic
 
 2.1 Alpha 1 - 11/29/2014
 	- Added support for custom fields in NAT and ACL rules, as this allows

lib/iptables.inc

@@ -184,9 +184,11 @@ function enable_mss_clamp {
 			[[ -z ${msssize} ]] && msssize="-"
 			[[ ${msssize} != "-" ]] && msssize="--set-mss ${msssize}"
 			[[ ${msssize} == "-" ]] && msssize="--clamp-mss-to-pmtu"
+			[[ ${interface} == "all" ]] && interface=""
+			[[ ${interface} != "all" ]] && interface="-o ${interface}"
 			${debug} ${DebugColor} "${FUNCNAME}:${DEFAULT_COLOR} Read: ${interface} ${mss} ${type} ${msssize}"
 			${VER_IPTABLES} -A ${type} -p tcp --tcp-flags SYN,RST SYN -j TCPMSS \
-				 -o ${interface} -m tcpmss --mss ${mss} ${msssize}
+				 ${interface} -m tcpmss --mss ${mss} ${msssize}
 			unset interface mss type msssize
 		done < "${FWCONFIGDIR}/ipv${IPVER}/mss-clamp.conf"