EVOLUTION-MANAGER

Edit File: firewall.sh

#!/bin/sh # A Sample OpenVPN-aware firewall. # eth0 is connected to the internet. # eth1 is connected to a private subnet. # Change this subnet to correspond to your private # ethernet subnet. Home will use HOME_NET/24 and # Office will use OFFICE_NET/24. PRIVATE=10.0.0.0/24 # Loopback address LOOP=127.0.0.1 # Delete old iptables rules # and temporarily block all traffic. iptables -P OUTPUT DROP iptables -P INPUT DROP iptables -P FORWARD DROP iptables -F # Set default policies iptables -P OUTPUT ACCEPT iptables -P INPUT DROP iptables -P FORWARD DROP # Prevent external packets from using loopback addr iptables -A INPUT -i eth0 -s $LOOP -j DROP iptables -A FORWARD -i eth0 -s $LOOP -j DROP iptables -A INPUT -i eth0 -d $LOOP -j DROP iptables -A FORWARD -i eth0 -d $LOOP -j DROP # Anything coming from the Internet should have a real Internet address iptables -A FORWARD -i eth0 -s 192.168.0.0/16 -j DROP iptables -A FORWARD -i eth0 -s 172.16.0.0/12 -j DROP iptables -A FORWARD -i eth0 -s 10.0.0.0/8 -j DROP iptables -A INPUT -i eth0 -s 192.168.0.0/16 -j DROP iptables -A INPUT -i eth0 -s 172.16.0.0/12 -j DROP iptables -A INPUT -i eth0 -s 10.0.0.0/8 -j DROP # Block outgoing NetBios (if you have windows machines running # on the private subnet). This will not affect any NetBios # traffic that flows over the VPN tunnel, but it will stop # local windows machines from broadcasting themselves to # the internet. iptables -A FORWARD -p tcp --sport 137:139 -o eth0 -j DROP iptables -A FORWARD -p udp --sport 137:139 -o eth0 -j DROP iptables -A OUTPUT -p tcp --sport 137:139 -o eth0 -j DROP iptables -A OUTPUT -p udp --sport 137:139 -o eth0 -j DROP # Check source address validity on packets going out to internet iptables -A FORWARD -s ! $PRIVATE -i eth1 -j DROP # Allow local loopback iptables -A INPUT -s $LOOP -j ACCEPT iptables -A INPUT -d $LOOP -j ACCEPT # Allow incoming pings (can be disabled) iptables -A INPUT -p icmp --icmp-type echo-request -j ACCEPT # Allow services such as www and ssh (can be disabled) iptables -A INPUT -p tcp --dport http -j ACCEPT iptables -A INPUT -p tcp --dport ssh -j ACCEPT # Allow incoming OpenVPN packets # Duplicate the line below for each # OpenVPN tunnel, changing --dport n # to match the OpenVPN UDP port. # # In OpenVPN, the port number is # controlled by the --port n option. # If you put this option in the config # file, you can remove the leading '--' # # If you taking the stateful firewall # approach (see the OpenVPN HOWTO), # then comment out the line below. iptables -A INPUT -p udp --dport 1194 -j ACCEPT # Allow packets from TUN/TAP devices. # When OpenVPN is run in a secure mode, # it will authenticate packets prior # to their arriving on a tun or tap # interface. Therefore, it is not # necessary to add any filters here, # unless you want to restrict the # type of packets which can flow over # the tunnel. iptables -A INPUT -i tun+ -j ACCEPT iptables -A FORWARD -i tun+ -j ACCEPT iptables -A INPUT -i tap+ -j ACCEPT iptables -A FORWARD -i tap+ -j ACCEPT # Allow packets from private subnets iptables -A INPUT -i eth1 -j ACCEPT iptables -A FORWARD -i eth1 -j ACCEPT # Keep state of connections from local machine and private subnets iptables -A OUTPUT -m state --state NEW -o eth0 -j ACCEPT iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT iptables -A FORWARD -m state --state NEW -o eth0 -j ACCEPT iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT # Masquerade local subnet iptables -t nat -A POSTROUTING -s $PRIVATE -o eth0 -j MASQUERADE