iptables -P INPUT DROP
iptables -P OUTPUT DROP
iptables -P FORWARD DROP

iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT

iptables -A INPUT -p udp -m udp --dport 137:138 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 139 -j ACCEPT
iptables -A INPUT -p tcp -m tcp --dport 445 -j ACCEPT
iptables -A INPUT -s 127.0.0.1 -j ACCEPT

iptables -A OUTPUT -p udp -m udp --dport 137:138 -j ACCEPT
iptables -A OUTPUT -p tcp -m tcp --dport 139 -j ACCEPT
iptables -A OUTPUT -p tcp -m tcp --dport 445 -j ACCEPT
iptables -A OUTPUT -d 127.0.0.1 -j ACCEPT