option src lan
option dest wan
+## Enable this option if you encounter any MTU problems
+## e.g. some websites work, others do not, submitting
+## forms causes problems, ...
+# option mtu_fix 1
+
### EXAMPLE CONFIG SECTIONS
# do not allow a specific ip to access wan
config_set $ZONE_LIST $1 1
$IPTABLES -N zone_$1
+ $IPTABLES -N zone_$1_MSSFIX
$IPTABLES -N zone_$1_ACCEPT
$IPTABLES -N zone_$1_DROP
$IPTABLES -N zone_$1_REJECT
[ -n "$dev" -a "$dev" == "$1" ] && return
logger "adding $1 to firewall zone $2"
$IPTABLES -A input -i $1 -j zone_$2
+ $IPTABLES -I zone_$2_MSSFIX 1 -o $1 -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
$IPTABLES -I zone_$2_ACCEPT 1 -o $1 -j ACCEPT
$IPTABLES -I zone_$2_DROP 1 -o $1 -j DROP
$IPTABLES -I zone_$2_REJECT 1 -o $1 -j reject
$IPTABLES -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
$IPTABLES -A FORWARD -m state --state INVALID -j DROP
- $IPTABLES -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
$IPTABLES -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT
$IPTABLES -A INPUT -i lo -j ACCEPT
config_get src $1 src
config_get dest $1 dest
+ config_get_bool mtu_fix $1 mtu_fix 0
[ -n "$src" ] && z_src=zone_${src}_forward || z_src=forward
[ -n "$dest" ] && z_dest=zone_${dest}_ACCEPT || z_dest=ACCEPT
$IPTABLES -I $z_src 1 -j $z_dest
+ [ "$mtu_fix" -gt 0 -a -n "$dest" ] && $IPTABLES -I $z_src 1 -j zone_${dest}_MSSFIX
}
fw_redirect() {