#!/bin/sh
INET_IFACE="venet0"
INET_ADDRESS="79.99.1.170"
LO_IFACE="lo"
LO_IP="127.0.0.1"
echo "Loading kernel modules ..."
# depmod -a
/sbin/modprobe ip_tables
/sbin/modprobe ip_conntrack
/sbin/modprobe ip_nat_ftp
/sbin/modprobe ip_conntrack_ftp
/sbin/modprobe ip_conntrack_irc
echo "Configuring system ..."
# /sbin/sysctl -w net.ipv4.tcp_syncookies="1"
/sbin/sysctl -w net.ipv4.conf.all.rp_filter="1"
# /sbin/sysctl -w net.ipv4.icmp_echo_ignore_broadcasts="1"
/sbin/sysctl -w net.ipv4.conf.all.accept_source_route="0"
/sbin/sysctl -w net.ipv4.conf.all.accept_redirects="0"
/sbin/sysctl -w net.ipv4.conf.all.secure_redirects="1"
/sbin/sysctl -w net.ipv4.conf.all.log_martians="1"
echo "Flushing Tables ..."
/sbin/iptables -P INPUT ACCEPT
/sbin/iptables -P FORWARD ACCEPT
/sbin/iptables -P OUTPUT ACCEPT
/sbin/iptables -t nat -P PREROUTING ACCEPT
/sbin/iptables -t nat -P POSTROUTING ACCEPT
/sbin/iptables -t nat -P OUTPUT ACCEPT
/sbin/iptables -t mangle -P PREROUTING ACCEPT
/sbin/iptables -t mangle -P OUTPUT ACCEPT
/sbin/iptables -F
/sbin/iptables -t nat -F
/sbin/iptables -t mangle -F
/sbin/iptables -X
/sbin/iptables -t nat -X
/sbin/iptables -t mangle -X
echo "Locking server down ..."
/sbin/iptables -P INPUT DROP
/sbin/iptables -P OUTPUT DROP
/sbin/iptables -P FORWARD DROP
echo "Building namespaces ..."
/sbin/iptables -N bad_packets
/sbin/iptables -N bad_tcp_packets
/sbin/iptables -N icmp_packets
/sbin/iptables -N udp_inbound
/sbin/iptables -N udp_outbound
/sbin/iptables -N tcp_inbound
/sbin/iptables -N tcp_outbound
echo "Handling bad packets ..."
/sbin/iptables -A bad_packets -p ALL -m state --state INVALID -j LOG \
    --log-prefix "Invalid packet: "
/sbin/iptables -A bad_packets -p ALL -m state --state INVALID -j DROP
/sbin/iptables -A bad_packets -p tcp -j bad_tcp_packets
/sbin/iptables -A bad_packets -p ALL -j RETURN
echo "Handling bad TCP packets ..."
/sbin/iptables -A bad_tcp_packets -p tcp ! --syn -m state --state NEW -j LOG \
    --log-prefix "New not syn: "
/sbin/iptables -A bad_tcp_packets -p tcp ! --syn -m state --state NEW -j DROP
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags ALL NONE -j LOG \
    --log-prefix "Stealth scan: "
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags ALL NONE -j DROP
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags ALL ALL -j LOG \
    --log-prefix "Stealth scan: "
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags ALL ALL -j DROP
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags ALL FIN,URG,PSH -j LOG \
    --log-prefix "Stealth scan: "
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags ALL FIN,URG,PSH -j DROP
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j LOG \
    --log-prefix "Stealth scan: "
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags SYN,RST SYN,RST -j LOG \
    --log-prefix "Stealth scan: "
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags SYN,RST SYN,RST -j DROP
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags SYN,FIN SYN,FIN -j LOG \
    --log-prefix "Stealth scan: "
/sbin/iptables -A bad_tcp_packets -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP
/sbin/iptables -A bad_tcp_packets -p tcp -j RETURN
echo "Handling ICMP packets ..."
/sbin/iptables -A icmp_packets --fragment -p ICMP -j LOG \
    --log-prefix "ICMP Fragment: "
/sbin/iptables -A icmp_packets --fragment -p ICMP -j DROP
/sbin/iptables -A icmp_packets -p ICMP -s 0/0 --icmp-type 8 -j DROP
/sbin/iptables -A icmp_packets -p ICMP -s 0/0 --icmp-type 11 -j ACCEPT
/sbin/iptables -A icmp_packets -p ICMP -j RETURN
echo "Handling UDP"
/sbin/iptables -A udp_inbound -p UDP -s 0/0 --destination-port 137 -j DROP
/sbin/iptables -A udp_inbound -p UDP -s 0/0 --destination-port 138 -j DROP
/sbin/iptables -A udp_inbound -p UDP -s 0/0 --destination-port 9000:9024 -j ACCEPT
/sbin/iptables -A udp_inbound -p UDP -j RETURN
/sbin/iptables -A udp_outbound -p UDP -s 0/0 -j ACCEPT
echo "Handling TCP"
/sbin/iptables -A tcp_inbound -p TCP -s 0/0 --destination-port 80 -j ACCEPT
/sbin/iptables -A tcp_inbound -p TCP -s 0/0 --destination-port 21 -j ACCEPT
/sbin/iptables -A tcp_inbound -p TCP -s 0/0 --source-port 20 -j ACCEPT
/sbin/iptables -A tcp_inbound -p TCP -s 0/0 --destination-port 62000:64000 -j ACCEPT
/sbin/iptables -A tcp_inbound -p TCP -s 0/0 --destination-port 22 -j ACCEPT
/sbin/iptables -A tcp_inbound -p TCP -s 0/0 --destination-port 8000:8006 -j ACCEPT
/sbin/iptables -A tcp_inbound -p TCP -s 0/0 --destination-port 8895 -j ACCEPT
/sbin/iptables -A tcp_inbound -p TCP -s 0/0 --destination-port 9000:9024 -j ACCEPT
/sbin/iptables -A tcp_inbound -p TCP -j RETURN
/sbin/iptables -A tcp_outbound -p TCP -s 0/0 -j ACCEPT
echo "Handlng Input"
/sbin/iptables -A INPUT -p ALL -i $LO_IFACE -j ACCEPT
/sbin/iptables -A INPUT -p ALL -j bad_packets
/sbin/iptables -A INPUT -p ALL -d 224.0.0.1 -j DROP
/sbin/iptables -A INPUT -p ALL -i $INET_IFACE -m state --state ESTABLISHED,RELATED \
     -j ACCEPT
/sbin/iptables -A INPUT -p TCP -i $INET_IFACE -j tcp_inbound
/sbin/iptables -A INPUT -p UDP -i $INET_IFACE -j udp_inbound
/sbin/iptables -A INPUT -p ICMP -i $INET_IFACE -j icmp_packets
# /sbin/iptables -A INPUT -m pkttype --pkt-type broadcast -j DROP
/sbin/iptables -A INPUT -m limit --limit 3/minute --limit-burst 3 -j LOG \
    --log-prefix "INPUT packet died: "
echo "Handling output"
/sbin/iptables -A OUTPUT -m state -p icmp --state INVALID -j DROP
/sbin/iptables -A OUTPUT -p ALL -s $LO_IP -j ACCEPT
/sbin/iptables -A OUTPUT -p ALL -o $LO_IFACE -j ACCEPT
/sbin/iptables -A OUTPUT -p ALL -o $INET_IFACE -j ACCEPT
/sbin/iptables -A OUTPUT -m limit --limit 3/minute --limit-burst 3 -j LOG \
    --log-prefix "OUTPUT packet died: "
echo " [IPtables built]"