rc.firewall revision 73842
166830Sobrien# Copyright (c) 1996 Poul-Henning Kamp 266830Sobrien# All rights reserved. 366830Sobrien# 466830Sobrien# Redistribution and use in source and binary forms, with or without 566830Sobrien# modification, are permitted provided that the following conditions 666830Sobrien# are met: 766830Sobrien# 1. Redistributions of source code must retain the above copyright 866830Sobrien# notice, this list of conditions and the following disclaimer. 966830Sobrien# 2. Redistributions in binary form must reproduce the above copyright 1066830Sobrien# notice, this list of conditions and the following disclaimer in the 1166830Sobrien# documentation and/or other materials provided with the distribution. 1266830Sobrien# 1366830Sobrien# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1466830Sobrien# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1566830Sobrien# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1666830Sobrien# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1766830Sobrien# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1866830Sobrien# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 1966830Sobrien# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2066830Sobrien# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2166830Sobrien# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2266830Sobrien# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2366830Sobrien# SUCH DAMAGE. 2466830Sobrien# 2550472Speter# $FreeBSD: head/etc/rc.firewall 73842 2001-03-06 02:15:38Z obrien $ 2666830Sobrien# 2715027Sphk 2866830Sobrien# 2966830Sobrien# Setup system for firewall service. 3066830Sobrien# 3166830Sobrien 3243849Sjkh# Suck in the configuration variables. 3351231Ssheldonhif [ -r /etc/defaults/rc.conf ]; then 3443849Sjkh . /etc/defaults/rc.conf 3559674Ssheldonh source_rc_confs 3651231Ssheldonhelif [ -r /etc/rc.conf ]; then 3733203Sadam . /etc/rc.conf 3833203Sadamfi 3933203Sadam 4015027Sphk############ 4129300Sdanny# Define the firewall type in /etc/rc.conf. Valid values are: 4229300Sdanny# open - will allow anyone in 4329300Sdanny# client - will try to protect just this machine 4429300Sdanny# simple - will try to protect a whole network 4529300Sdanny# closed - totally disables IP services except via lo0 interface 4629300Sdanny# UNKNOWN - disables the loading of firewall rules. 4729300Sdanny# filename - will load the rules in the given filename (full path required) 4815027Sphk# 4951231Ssheldonh# For ``client'' and ``simple'' the entries below should be customized 5029300Sdanny# appropriately. 5115027Sphk 5215027Sphk############ 5315027Sphk# 5415027Sphk# If you don't know enough about packet filtering, we suggest that you 5515027Sphk# take time to read this book: 5615027Sphk# 5773023Sdes# Building Internet Firewalls, 2nd Edition 5815210Sphk# Brent Chapman and Elizabeth Zwicky 5915210Sphk# 6015210Sphk# O'Reilly & Associates, Inc 6173023Sdes# ISBN 1-56592-871-7 6225478Sjkh# http://www.ora.com/ 6373023Sdes# http://www.oreilly.com/catalog/fire2/ 6415210Sphk# 6515210Sphk# For a more advanced treatment of Internet Security read: 6615210Sphk# 6715027Sphk# Firewalls & Internet Security 6815027Sphk# Repelling the wily hacker 6915027Sphk# William R. Cheswick, Steven M. Bellowin 7015027Sphk# 7115027Sphk# Addison-Wesley 7273023Sdes# ISBN 0-201-63357-4 7325478Sjkh# http://www.awl.com/ 7473023Sdes# http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html 7515027Sphk# 7615027Sphk 7751231Ssheldonhif [ -n "${1}" ]; then 7851231Ssheldonh firewall_type="${1}" 7929300Sdannyfi 8029300Sdanny 8115027Sphk############ 8229300Sdanny# Set quiet mode if requested 8351231Ssheldonh# 8451231Ssheldonhcase ${firewall_quiet} in 8551231Ssheldonh[Yy][Ee][Ss]) 8629300Sdanny fwcmd="/sbin/ipfw -q" 8751231Ssheldonh ;; 8851231Ssheldonh*) 8929300Sdanny fwcmd="/sbin/ipfw" 9051231Ssheldonh ;; 9151231Ssheldonhesac 9229300Sdanny 9329300Sdanny############ 9416578Salex# Flush out the list before we begin. 9551231Ssheldonh# 9650357Ssheldonh${fwcmd} -f flush 9716578Salex 9816578Salex############ 9964244Sru# Network Address Translation. All packets are passed to natd(8) 10064244Sru# before they encounter your remaining rules. The firewall rules 10164244Sru# will then be run again on each packet after translation by natd 10264244Sru# starting at the rule number following the divert rule. 10351231Ssheldonh# 10464244Sru# For ``simple'' firewall type the divert rule should be put to a 10564244Sru# different place to not interfere with address-checking rules. 10673842Sobrien# 10764244Srucase ${firewall_type} in 10865257Sru[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 10964244Sru case ${natd_enable} in 11064244Sru [Yy][Ee][Ss]) 11164244Sru if [ -n "${natd_interface}" ]; then 11264244Sru ${fwcmd} add 50 divert natd all from any to any via ${natd_interface} 11364244Sru fi 11464244Sru ;; 11564244Sru esac 11651231Ssheldonhesac 11735267Sbrian 11835267Sbrian############ 11915027Sphk# If you just configured ipfw in the kernel as a tool to solve network 12015027Sphk# problems or you just want to disallow some particular kinds of traffic 12151805Smpp# then you will want to change the default policy to open. You can also 12217594Sjkh# do this as your only action by setting the firewall_type to ``open''. 12351231Ssheldonh# 12450357Ssheldonh# ${fwcmd} add 65000 pass all from any to any 12515027Sphk 12615027Sphk############ 12730617Sdanny# Only in rare cases do you want to change these rules 12851231Ssheldonh# 12950357Ssheldonh${fwcmd} add 100 pass all from any to any via lo0 13050357Ssheldonh${fwcmd} add 200 deny all from any to 127.0.0.0/8 13173785Sobrien${fwcmd} add 300 deny ip from 127.0.0.0/8 to any 13252449Snsayer# If you're using 'options BRIDGE', uncomment the following line to pass ARP 13373785Sobrien#${fwcmd} add 400 pass udp from 0.0.0.0 2054 to 0.0.0.0 13415027Sphk 13515027Sphk 13617594Sjkh# Prototype setups. 13751231Ssheldonh# 13851231Ssheldonhcase ${firewall_type} in 13951231Ssheldonh[Oo][Pp][Ee][Nn]) 14050357Ssheldonh ${fwcmd} add 65000 pass all from any to any 14151231Ssheldonh ;; 14254108Sobrien 14351231Ssheldonh[Cc][Ll][Ii][Ee][Nn][Tt]) 14451231Ssheldonh ############ 14551231Ssheldonh # This is a prototype setup that will protect your system somewhat 14651231Ssheldonh # against people from outside your own network. 14751231Ssheldonh ############ 14829300Sdanny 14951231Ssheldonh # set these to your network and netmask and ip 15056736Srgrimes net="192.0.2.0" 15151231Ssheldonh mask="255.255.255.0" 15256736Srgrimes ip="192.0.2.1" 15317594Sjkh 15451231Ssheldonh # Allow any traffic to or from my own net. 15551231Ssheldonh ${fwcmd} add pass all from ${ip} to ${net}:${mask} 15651231Ssheldonh ${fwcmd} add pass all from ${net}:${mask} to ${ip} 15715027Sphk 15851231Ssheldonh # Allow TCP through if setup succeeded 15951231Ssheldonh ${fwcmd} add pass tcp from any to any established 16015027Sphk 16152873Sru # Allow IP fragments to pass through 16252873Sru ${fwcmd} add pass all from any to any frag 16352873Sru 16451231Ssheldonh # Allow setup of incoming email 16551231Ssheldonh ${fwcmd} add pass tcp from any to ${ip} 25 setup 16615027Sphk 16751231Ssheldonh # Allow setup of outgoing TCP connections only 16851231Ssheldonh ${fwcmd} add pass tcp from ${ip} to any setup 16915027Sphk 17051231Ssheldonh # Disallow setup of all other TCP connections 17151231Ssheldonh ${fwcmd} add deny tcp from any to any setup 17215027Sphk 17351231Ssheldonh # Allow DNS queries out in the world 17472772Snsayer ${fwcmd} add pass udp from ${ip} to any 53 keep-state 17515027Sphk 17651231Ssheldonh # Allow NTP queries out in the world 17772772Snsayer ${fwcmd} add pass udp from ${ip} to any 123 keep-state 17815027Sphk 17951231Ssheldonh # Everything else is denied by default, unless the 18051231Ssheldonh # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 18151231Ssheldonh # config file. 18251231Ssheldonh ;; 18315027Sphk 18451231Ssheldonh[Ss][Ii][Mm][Pp][Ll][Ee]) 18551231Ssheldonh ############ 18651231Ssheldonh # This is a prototype setup for a simple firewall. Configure this 18751231Ssheldonh # machine as a named server and ntp server, and point all the machines 18851231Ssheldonh # on the inside at this machine for those services. 18951231Ssheldonh ############ 19015027Sphk 19151231Ssheldonh # set these to your outside interface network and netmask and ip 19251231Ssheldonh oif="ed0" 19356736Srgrimes onet="192.0.2.0" 19456736Srgrimes omask="255.255.255.240" 19556736Srgrimes oip="192.0.2.1" 19617594Sjkh 19751231Ssheldonh # set these to your inside interface network and netmask and ip 19851231Ssheldonh iif="ed1" 19956736Srgrimes inet="192.0.2.16" 20056736Srgrimes imask="255.255.255.240" 20156736Srgrimes iip="192.0.2.17" 20215027Sphk 20351231Ssheldonh # Stop spoofing 20451231Ssheldonh ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 20551231Ssheldonh ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 20615027Sphk 20751231Ssheldonh # Stop RFC1918 nets on the outside interface 20856736Srgrimes ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 20956736Srgrimes ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 21056736Srgrimes ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 21115027Sphk 21264028Sobrien # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 21364028Sobrien # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 21464028Sobrien # on the outside interface 21556736Srgrimes ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 21656736Srgrimes ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 21756736Srgrimes ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 21856736Srgrimes ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 21956736Srgrimes ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 22056736Srgrimes 22164244Sru # Network Address Translation. This rule is placed here deliberately 22264244Sru # so that it does not interfere with the surrounding address-checking 22364244Sru # rules. If for example one of your internal LAN machines had its IP 22464244Sru # address set to 192.0.2.1 then an incoming packet for it after being 22564244Sru # translated by natd(8) would match the `deny' rule above. Similarly 22664244Sru # an outgoing packet originated from it before being translated would 22764244Sru # match the `deny' rule below. 22864244Sru case ${natd_enable} in 22964244Sru [Yy][Ee][Ss]) 23064244Sru if [ -n "${natd_interface}" ]; then 23164244Sru ${fwcmd} add divert natd all from any to any via ${natd_interface} 23264244Sru fi 23364244Sru ;; 23464244Sru esac 23564244Sru 23664244Sru # Stop RFC1918 nets on the outside interface 23764244Sru ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 23864244Sru ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 23964244Sru ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 24064244Sru 24164244Sru # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 24264244Sru # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 24364244Sru # on the outside interface 24464244Sru ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 24564244Sru ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 24664244Sru ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 24764244Sru ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 24864244Sru ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 24964244Sru 25051231Ssheldonh # Allow TCP through if setup succeeded 25151231Ssheldonh ${fwcmd} add pass tcp from any to any established 25215027Sphk 25352873Sru # Allow IP fragments to pass through 25452873Sru ${fwcmd} add pass all from any to any frag 25552873Sru 25651231Ssheldonh # Allow setup of incoming email 25751231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 25 setup 25815027Sphk 25951231Ssheldonh # Allow access to our DNS 26051231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 53 setup 26152404Sru ${fwcmd} add pass udp from any to ${oip} 53 26252404Sru ${fwcmd} add pass udp from ${oip} 53 to any 26315027Sphk 26451231Ssheldonh # Allow access to our WWW 26551231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 80 setup 26615027Sphk 26751231Ssheldonh # Reject&Log all setup of incoming connections from the outside 26851231Ssheldonh ${fwcmd} add deny log tcp from any to any in via ${oif} setup 26915027Sphk 27051231Ssheldonh # Allow setup of any other TCP connection 27151231Ssheldonh ${fwcmd} add pass tcp from any to any setup 27215027Sphk 27351231Ssheldonh # Allow DNS queries out in the world 27472772Snsayer ${fwcmd} add pass udp from ${oip} to any 53 keep-state 27515027Sphk 27651231Ssheldonh # Allow NTP queries out in the world 27772772Snsayer ${fwcmd} add pass udp from ${oip} to any 123 keep-state 27815027Sphk 27951231Ssheldonh # Everything else is denied by default, unless the 28051231Ssheldonh # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 28151231Ssheldonh # config file. 28251231Ssheldonh ;; 28315027Sphk 28451231Ssheldonh[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 28551231Ssheldonh ;; 28651231Ssheldonh*) 28759669Sbsd if [ -r "${firewall_type}" ]; then 28857014Spaul ${fwcmd} ${firewall_flags} ${firewall_type} 28951231Ssheldonh fi 29051231Ssheldonh ;; 29151231Ssheldonhesac 292