/etc/firewall.user

# This assumes your gateway is an OpenWRT box at 192.168.1.1,
# your lan is 192.168.1.0/24,
# and your OpenWRT stock chains are intact.
# It is different than the built in /etc/config/firewall rules in that it allows you to address 
# your linux box at example.com, whether your request originates from within your lan, or from outside.

WIN_XP_HOST=192.168.1.184                                                                                                                                                          
LINUX_HOST=192.168.1.202
WWW_NAME=example.com                                                                                                                                                           

forward () {                                                                                                                                                                       
        DESTINATION_HOST=$1                                                                                                                                                        
        PORT_LIST=$2                                                                                                                                                               
        iptables        -A forwarding_wan   -d $DESTINATION_HOST                                                                        -j ACCEPT                                  
        iptables -t nat -A prerouting_wan                                                       -p tcp -m multiport --dports $PORT_LIST -j DNAT --to $DESTINATION_HOST             
        iptables -t nat -A prerouting_rule  -d $WWW_NAME         -s 192.168.1.0/24       -p tcp -m multiport --dports $PORT_LIST -j DNAT --to $DESTINATION_HOST             
        iptables -t nat -A postrouting_rule -d $DESTINATION_HOST        -s 192.168.1.0/24       -p tcp -m multiport --dports $PORT_LIST -j SNAT --to 192.168.1.1                   
}                                                                                                                                                                                  
                                                                                                                                                                                   
forward $WIN_XP_HOST 21,3389,50000,50001,50002,50003,50004,50005                                                                                                                   
forward $LINUX_HOST  22,80