firewall-standalone

linux下的拨号程序rp-pppoe.3.7

#!/bin/sh
#
# firewall-standalone	This script sets up firewall rules for a standalone
#                       machine
#
# Copyright (C) 2005 Roaring Penguin Software Inc.  This software may
# be distributed under the terms of the GNU General Public License, version
# 2 or any later version.
# LIC: GPL

# Interface to Internet
EXTIF=ppp+

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

iptables -F FORWARD
iptables -F INPUT
iptables -F OUTPUT

# Deny TCP and UDP packets to privileged ports
iptables -A INPUT -p udp -i $EXTIF --dport 0:1023 -j LOG
iptables -A INPUT -p tcp -i $EXTIF --dport 0:1023 -j LOG
iptables -A INPUT -p udp -i $EXTIF --dport 0:1023 -j DROP
iptables -A INPUT -p tcp -i $EXTIF --dport 0:1023 -j DROP

# Deny TCP connection attempts
iptables -A INPUT -i $EXTIF -p tcp --syn -j LOG
iptables -A INPUT -i $EXTIF -p tcp --syn -j DROP

# Deny ICMP echo-requests
iptables -A INPUT -i $EXTIF -p icmp --icmp-type echo-request -j DROP