初始化简单的IP放火墙（Script）(转)[@more@]

#!/bin/sh

#

# rc.firewall - Initial SIMPLE IP Firewall test script for 2.4.x

#

# Author: Oskar Andreasson

# (c) of BoingWorld.com, use at your own risk, do whatever you please with

# it as long as you don't distribute this with due credits to

# BoingWorld.com

#

###########

# Configuration options, these will speed you up getting this script to

# work with your own setup.

#

# your LAN's IP range and localhost IP. /24 means to only use the first 24

# bits of the 32 bit IP adress. the same as netmask 255.255.255.0

#

# STATIC_IP is used by me to allow myself to do anything to myself, might

# be a security risc but sometimes I want this. If you don't have a static

# IP, I suggest not using this option at all for now but it's still

# enabled per default and will add some really nifty security bugs for all

# those who skips reading the documentation=)

LAN_IP_RANGE="192.168.0.0/24"

LAN_IP="192.168.0.2/32"

LAN_BCAST_ADRESS="192.168.0.255/32"

LOCALHOST_IP="127.0.0.1/32"

STATIC_IP="194.236.50.155/32"

INET_IFACE="eth0"

LAN_IFACE="eth1"

IPTABLES="/usr/local/sbin/iptables"

#########

# Load all required IPTables modules

#

# Needed to initially load modules

#

/sbin/depmod -a

#

# Adds some iptables targets like LOG, REJECT and MASQUARADE.

#

/sbin/modprobe ipt_LOG

#/sbin/modprobe ipt_REJECT

#/sbin/modprobe ipt_MASQUERADE

#

# Support for owner matching

#

#/sbin/modprobe ipt_owner

#

# Support for connection tracking of FTP and IRC.

#

#/sbin/modprobe ip_conntrack_ftp

#/sbin/modprobe ip_conntrack_irc

#CRITICAL: Enable IP forwarding since it is disabled by default.

#

echo "1" > /proc/sys/net/ipv4/ip_forward

# Dynamic IP users:

#

# If you get your IP address dynamically from SLIP, PPP, or DHCP, enable this

# option. This enables dynamic-ip address hacking in IP MASQ, making the connection

# with Diald and similar programs much easier.

#

#echo "1" > /proc/sys/net/ipv4/ip_dynaddr

# Enable simple IP FORWARDing and Masquerading

#

# NOTE: The following is an example for an internal LAN, where the lan

# runs on eth1, and the Internet is on eth0.

#

# Please change the network devices to match your own configuration.

#

$IPTABLES -t nat -A POSTROUTING -o $INET_IFACE -j MASQUERADE

$IPTABLES -A FORWARD -i $LAN_IFACE -j ACCEPT

$IPTABLES -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT

$IPTABLES -A FORWARD -m limit --limit 3/minute --limit-burst 3 -j LOG --log-level DEBUG --log-prefix "IPT FORWARD packet died: "

#

# set default policies for the INPUT, FORWARD and OUTPUT chains

#

$IPTABLES -P INPUT DROP

$IPTABLES -P OUTPUT DROP

$IPTABLES -P FORWARD DROP

#

# Create separate chains for ICMP, TCP and UDP to traverse

#

$IPTABLES -N icmp_packets

$IPTABLES -N tcp_packets

$IPTABLES -N udpincoming_packets

#

# the allowed chain for TCP connections

#

# This chain will be utilised if someone tries to connect to an allowed

# port from the internet. If they are opening the connection, or if it's

# already established we ACCEPT the packages, if not we fuck them. This is

# where the state matching is performed also, we allow ESTABLISHED and

# RELATED packets.

$IPTABLES -N allowed

$IPTABLES -A allowed -p TCP --syn -j ACCEPT

$IPTABLES -A allowed -p TCP -m state --state ESTABLISHED,RELATED -j ACCEPT

$IPTABLES -A allowed -p TCP -j DROP

#

# ICMP rules

#

$IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 0 -j ACCEPT

$IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 3 -j ACCEPT

$IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 5 -j ACCEPT

$IPTABLES -A icmp_packets -p ICMP -s 0/0 --icmp-type 11 -j ACCEPT

#

# TCP rules

#

$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 21 -j allowed

$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 22 -j allowed

$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 80 -j allowed

$IPTABLES -A tcp_packets -p TCP -s 0/0 --dport 113 -j allowed

#

# UDP ports

#

$IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 53 -j ACCEPT

$IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 123 -j ACCEPT

$IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 2074 -j ACCEPT

$IPTABLES -A udpincoming_packets -p UDP -s 0/0 --source-port 4000 -j ACCEPT

#

# PREROUTING chain.

#

# Do some checks for obviously spoofed IP's

#

$IPTABLES -t nat -A PREROUTING -i $INET_IFACE -s 192.168.0.0/16 -j DROP

$IPTABLES -t nat -A PREROUTING -i $INET_IFACE -s 10.0.0.0/8 -j DROP

$IPTABLES -t nat -A PREROUTING -i $INET_IFACE -s 172.16.0.0/12 -j DROP

#

# INPUT chain

#

# establish the basic INPUT chain and filter the packets onto the correct

# chains.

#

$IPTABLES -A INPUT -p ICMP -i $INET_IFACE -j icmp_packets

$IPTABLES -A INPUT -p TCP -i $INET_IFACE -j tcp_packets

$IPTABLES -A INPUT -p UDP -i $INET_IFACE -j udpincoming_packets

$IPTABLES -A INPUT -p ALL -i $LAN_IFACE -d $LAN_BCAST_ADRESS -j ACCEPT

$IPTABLES -A INPUT -p ALL -d $LOCALHOST_IP -j ACCEPT

$IPTABLES -A INPUT -p ALL -d $LAN_IP -j ACCEPT

$IPTABLES -A INPUT -p ALL -d $STATIC_IP -m state --state ESTABLISHED,RELATED -j ACCEPT

$IPTABLES -A INPUT -m limit --limit 3/minute --limit-burst 3 -j LOG --log-level DEBUG --log-prefix "IPT INPUT packet died: "

#

# OUTPUT chain

#

# establish the basic OUTPUT chain and filter them onto the correct chain

#

$IPTABLES -A OUTPUT -p ALL -s $LOCALHOST_IP -j ACCEPT

$IPTABLES -A OUTPUT -p ALL -s $LAN_IP -j ACCEPT

$IPTABLES -A OUTPUT -p ALL -s $STATIC_IP -j ACCEPT

$IPTABLES -A OUTPUT -m limit --limit 3/minute --limit-burst 3 -j LOG --log-level DEBUG --log-prefix "IPT OUTPUT packet died:

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初始化简单的IP放火墙（Script）(转)

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