rc.firewall revision 110476
1110476Strhodes#!/bin/sh - 266830Sobrien# Copyright (c) 1996 Poul-Henning Kamp 366830Sobrien# All rights reserved. 466830Sobrien# 566830Sobrien# Redistribution and use in source and binary forms, with or without 666830Sobrien# modification, are permitted provided that the following conditions 766830Sobrien# are met: 866830Sobrien# 1. Redistributions of source code must retain the above copyright 966830Sobrien# notice, this list of conditions and the following disclaimer. 1066830Sobrien# 2. Redistributions in binary form must reproduce the above copyright 1166830Sobrien# notice, this list of conditions and the following disclaimer in the 1266830Sobrien# documentation and/or other materials provided with the distribution. 1366830Sobrien# 1466830Sobrien# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1566830Sobrien# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1666830Sobrien# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1766830Sobrien# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1866830Sobrien# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1966830Sobrien# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2066830Sobrien# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2166830Sobrien# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2266830Sobrien# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2366830Sobrien# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2466830Sobrien# SUCH DAMAGE. 2566830Sobrien# 2650472Speter# $FreeBSD: head/etc/rc.firewall 110476 2003-02-06 22:00:38Z trhodes $ 2766830Sobrien# 2815027Sphk 2966830Sobrien# 3066830Sobrien# Setup system for firewall service. 3166830Sobrien# 3266830Sobrien 3343849Sjkh# Suck in the configuration variables. 3481618Sddif [ -z "${source_rc_confs_defined}" ]; then 3581618Sdd if [ -r /etc/defaults/rc.conf ]; then 3681618Sdd . /etc/defaults/rc.conf 3781618Sdd source_rc_confs 3881618Sdd elif [ -r /etc/rc.conf ]; then 3981618Sdd . /etc/rc.conf 4081618Sdd fi 4133203Sadamfi 4233203Sadam 4315027Sphk############ 4429300Sdanny# Define the firewall type in /etc/rc.conf. Valid values are: 4529300Sdanny# open - will allow anyone in 4629300Sdanny# client - will try to protect just this machine 4729300Sdanny# simple - will try to protect a whole network 4829300Sdanny# closed - totally disables IP services except via lo0 interface 4929300Sdanny# UNKNOWN - disables the loading of firewall rules. 5029300Sdanny# filename - will load the rules in the given filename (full path required) 5115027Sphk# 5251231Ssheldonh# For ``client'' and ``simple'' the entries below should be customized 5329300Sdanny# appropriately. 5415027Sphk 5515027Sphk############ 5615027Sphk# 5715027Sphk# If you don't know enough about packet filtering, we suggest that you 5815027Sphk# take time to read this book: 5915027Sphk# 6073023Sdes# Building Internet Firewalls, 2nd Edition 6115210Sphk# Brent Chapman and Elizabeth Zwicky 6215210Sphk# 6315210Sphk# O'Reilly & Associates, Inc 6473023Sdes# ISBN 1-56592-871-7 6525478Sjkh# http://www.ora.com/ 6673023Sdes# http://www.oreilly.com/catalog/fire2/ 6715210Sphk# 6815210Sphk# For a more advanced treatment of Internet Security read: 6915210Sphk# 7015027Sphk# Firewalls & Internet Security 7115027Sphk# Repelling the wily hacker 7215027Sphk# William R. Cheswick, Steven M. Bellowin 7315027Sphk# 7415027Sphk# Addison-Wesley 7573023Sdes# ISBN 0-201-63357-4 7625478Sjkh# http://www.awl.com/ 7773023Sdes# http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html 7815027Sphk# 7915027Sphk 8091019Scjcsetup_loopback () { 8191019Scjc ############ 8291019Scjc # Only in rare cases do you want to change these rules 8391019Scjc # 8491019Scjc ${fwcmd} add 100 pass all from any to any via lo0 8591019Scjc ${fwcmd} add 200 deny all from any to 127.0.0.0/8 8691019Scjc ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any 8791019Scjc} 8891019Scjc 8951231Ssheldonhif [ -n "${1}" ]; then 9051231Ssheldonh firewall_type="${1}" 9129300Sdannyfi 9229300Sdanny 9315027Sphk############ 9429300Sdanny# Set quiet mode if requested 9551231Ssheldonh# 9651231Ssheldonhcase ${firewall_quiet} in 9751231Ssheldonh[Yy][Ee][Ss]) 9829300Sdanny fwcmd="/sbin/ipfw -q" 9951231Ssheldonh ;; 10051231Ssheldonh*) 10129300Sdanny fwcmd="/sbin/ipfw" 10251231Ssheldonh ;; 10351231Ssheldonhesac 10429300Sdanny 10529300Sdanny############ 10616578Salex# Flush out the list before we begin. 10751231Ssheldonh# 10850357Ssheldonh${fwcmd} -f flush 10916578Salex 11016578Salex############ 11164244Sru# Network Address Translation. All packets are passed to natd(8) 11264244Sru# before they encounter your remaining rules. The firewall rules 11364244Sru# will then be run again on each packet after translation by natd 11464244Sru# starting at the rule number following the divert rule. 11551231Ssheldonh# 11664244Sru# For ``simple'' firewall type the divert rule should be put to a 11764244Sru# different place to not interfere with address-checking rules. 11873842Sobrien# 11964244Srucase ${firewall_type} in 12065257Sru[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 12164244Sru case ${natd_enable} in 12264244Sru [Yy][Ee][Ss]) 12364244Sru if [ -n "${natd_interface}" ]; then 12464244Sru ${fwcmd} add 50 divert natd all from any to any via ${natd_interface} 12564244Sru fi 12664244Sru ;; 12764244Sru esac 12851231Ssheldonhesac 12935267Sbrian 13035267Sbrian############ 13115027Sphk# If you just configured ipfw in the kernel as a tool to solve network 13215027Sphk# problems or you just want to disallow some particular kinds of traffic 13351805Smpp# then you will want to change the default policy to open. You can also 13417594Sjkh# do this as your only action by setting the firewall_type to ``open''. 13551231Ssheldonh# 13650357Ssheldonh# ${fwcmd} add 65000 pass all from any to any 13715027Sphk 13815027Sphk 13917594Sjkh# Prototype setups. 14051231Ssheldonh# 14151231Ssheldonhcase ${firewall_type} in 14251231Ssheldonh[Oo][Pp][Ee][Nn]) 14391019Scjc setup_loopback 14450357Ssheldonh ${fwcmd} add 65000 pass all from any to any 14551231Ssheldonh ;; 14654108Sobrien 14751231Ssheldonh[Cc][Ll][Ii][Ee][Nn][Tt]) 14851231Ssheldonh ############ 14951231Ssheldonh # This is a prototype setup that will protect your system somewhat 15051231Ssheldonh # against people from outside your own network. 15151231Ssheldonh ############ 15229300Sdanny 15351231Ssheldonh # set these to your network and netmask and ip 15456736Srgrimes net="192.0.2.0" 15551231Ssheldonh mask="255.255.255.0" 15656736Srgrimes ip="192.0.2.1" 15717594Sjkh 15891019Scjc setup_loopback 15991019Scjc 16051231Ssheldonh # Allow any traffic to or from my own net. 16151231Ssheldonh ${fwcmd} add pass all from ${ip} to ${net}:${mask} 16251231Ssheldonh ${fwcmd} add pass all from ${net}:${mask} to ${ip} 16315027Sphk 16451231Ssheldonh # Allow TCP through if setup succeeded 16551231Ssheldonh ${fwcmd} add pass tcp from any to any established 16615027Sphk 16752873Sru # Allow IP fragments to pass through 16852873Sru ${fwcmd} add pass all from any to any frag 16952873Sru 17051231Ssheldonh # Allow setup of incoming email 17151231Ssheldonh ${fwcmd} add pass tcp from any to ${ip} 25 setup 17215027Sphk 17351231Ssheldonh # Allow setup of outgoing TCP connections only 17451231Ssheldonh ${fwcmd} add pass tcp from ${ip} to any setup 17515027Sphk 17651231Ssheldonh # Disallow setup of all other TCP connections 17751231Ssheldonh ${fwcmd} add deny tcp from any to any setup 17815027Sphk 17951231Ssheldonh # Allow DNS queries out in the world 18072772Snsayer ${fwcmd} add pass udp from ${ip} to any 53 keep-state 18115027Sphk 18251231Ssheldonh # Allow NTP queries out in the world 18372772Snsayer ${fwcmd} add pass udp from ${ip} to any 123 keep-state 18415027Sphk 18551231Ssheldonh # Everything else is denied by default, unless the 18651231Ssheldonh # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 18751231Ssheldonh # config file. 18851231Ssheldonh ;; 18915027Sphk 19051231Ssheldonh[Ss][Ii][Mm][Pp][Ll][Ee]) 19151231Ssheldonh ############ 19251231Ssheldonh # This is a prototype setup for a simple firewall. Configure this 19351231Ssheldonh # machine as a named server and ntp server, and point all the machines 19451231Ssheldonh # on the inside at this machine for those services. 19551231Ssheldonh ############ 19615027Sphk 19751231Ssheldonh # set these to your outside interface network and netmask and ip 19851231Ssheldonh oif="ed0" 19956736Srgrimes onet="192.0.2.0" 20056736Srgrimes omask="255.255.255.240" 20156736Srgrimes oip="192.0.2.1" 20217594Sjkh 20351231Ssheldonh # set these to your inside interface network and netmask and ip 20451231Ssheldonh iif="ed1" 20556736Srgrimes inet="192.0.2.16" 20656736Srgrimes imask="255.255.255.240" 20756736Srgrimes iip="192.0.2.17" 20815027Sphk 20991019Scjc setup_loopback 21091019Scjc 21151231Ssheldonh # Stop spoofing 21251231Ssheldonh ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 21351231Ssheldonh ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 21415027Sphk 21551231Ssheldonh # Stop RFC1918 nets on the outside interface 21656736Srgrimes ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 21756736Srgrimes ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 21856736Srgrimes ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 21915027Sphk 22064028Sobrien # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 22164028Sobrien # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 22264028Sobrien # on the outside interface 22356736Srgrimes ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 22456736Srgrimes ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 22556736Srgrimes ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 22656736Srgrimes ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 22756736Srgrimes ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 22856736Srgrimes 22964244Sru # Network Address Translation. This rule is placed here deliberately 23064244Sru # so that it does not interfere with the surrounding address-checking 23164244Sru # rules. If for example one of your internal LAN machines had its IP 23264244Sru # address set to 192.0.2.1 then an incoming packet for it after being 23364244Sru # translated by natd(8) would match the `deny' rule above. Similarly 23464244Sru # an outgoing packet originated from it before being translated would 23564244Sru # match the `deny' rule below. 23664244Sru case ${natd_enable} in 23764244Sru [Yy][Ee][Ss]) 23864244Sru if [ -n "${natd_interface}" ]; then 23964244Sru ${fwcmd} add divert natd all from any to any via ${natd_interface} 24064244Sru fi 24164244Sru ;; 24264244Sru esac 24364244Sru 24464244Sru # Stop RFC1918 nets on the outside interface 24564244Sru ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 24664244Sru ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 24764244Sru ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 24864244Sru 24964244Sru # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 25064244Sru # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 25164244Sru # on the outside interface 25264244Sru ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 25364244Sru ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 25464244Sru ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 25564244Sru ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 25664244Sru ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 25764244Sru 25851231Ssheldonh # Allow TCP through if setup succeeded 25951231Ssheldonh ${fwcmd} add pass tcp from any to any established 26015027Sphk 26152873Sru # Allow IP fragments to pass through 26252873Sru ${fwcmd} add pass all from any to any frag 26352873Sru 26451231Ssheldonh # Allow setup of incoming email 26551231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 25 setup 26615027Sphk 26751231Ssheldonh # Allow access to our DNS 26851231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 53 setup 26952404Sru ${fwcmd} add pass udp from any to ${oip} 53 27052404Sru ${fwcmd} add pass udp from ${oip} 53 to any 27115027Sphk 27251231Ssheldonh # Allow access to our WWW 27351231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 80 setup 27415027Sphk 27551231Ssheldonh # Reject&Log all setup of incoming connections from the outside 27651231Ssheldonh ${fwcmd} add deny log tcp from any to any in via ${oif} setup 27715027Sphk 27851231Ssheldonh # Allow setup of any other TCP connection 27951231Ssheldonh ${fwcmd} add pass tcp from any to any setup 28015027Sphk 28151231Ssheldonh # Allow DNS queries out in the world 28272772Snsayer ${fwcmd} add pass udp from ${oip} to any 53 keep-state 28315027Sphk 28451231Ssheldonh # Allow NTP queries out in the world 28572772Snsayer ${fwcmd} add pass udp from ${oip} to any 123 keep-state 28615027Sphk 28751231Ssheldonh # Everything else is denied by default, unless the 28851231Ssheldonh # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 28951231Ssheldonh # config file. 29051231Ssheldonh ;; 29115027Sphk 29291019Scjc[Cc][Ll][Oo][Ss][Ee][Dd]) 29391019Scjc setup_loopback 29491019Scjc ;; 29551231Ssheldonh[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 29651231Ssheldonh ;; 29751231Ssheldonh*) 29859669Sbsd if [ -r "${firewall_type}" ]; then 29957014Spaul ${fwcmd} ${firewall_flags} ${firewall_type} 30051231Ssheldonh fi 30151231Ssheldonh ;; 30251231Ssheldonhesac 303