iptables -A INPUT -i tun0 -j ACCEPT
iptables -A FORWARD -i tun0 -j ACCEPT
iptables -A OUTPUT -o tun0 -j ACCEPT
iptables -A FORWARD -i tun0 -o eth0 -s 10.8.0.0/24 -j ACCEPT
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT