rc.firewall revision 165648
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 165648 2006-12-29 21:59:17Z piso $ 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: 45163749Sphk# open - will allow anyone in 46163749Sphk# client - will try to protect just this machine 47163749Sphk# simple - will try to protect a whole network 48163749Sphk# closed - totally disables IP services except via lo0 interface 49163749Sphk# workstation - will try to protect just this machine using statefull 50163749Sphk# firewalling. See below for rc.conf variables used 51163749Sphk# UNKNOWN - disables the loading of firewall rules. 52163749Sphk# filename - will load the rules in the given filename (full path required) 5315027Sphk# 5451231Ssheldonh# For ``client'' and ``simple'' the entries below should be customized 5529300Sdanny# appropriately. 5615027Sphk 5715027Sphk############ 5815027Sphk# 5915027Sphk# If you don't know enough about packet filtering, we suggest that you 6015027Sphk# take time to read this book: 6115027Sphk# 6273023Sdes# Building Internet Firewalls, 2nd Edition 6315210Sphk# Brent Chapman and Elizabeth Zwicky 6415210Sphk# 6515210Sphk# O'Reilly & Associates, Inc 6673023Sdes# ISBN 1-56592-871-7 6725478Sjkh# http://www.ora.com/ 6873023Sdes# http://www.oreilly.com/catalog/fire2/ 6915210Sphk# 7015210Sphk# For a more advanced treatment of Internet Security read: 7115210Sphk# 7215027Sphk# Firewalls & Internet Security 7315027Sphk# Repelling the wily hacker 7415027Sphk# William R. Cheswick, Steven M. Bellowin 7515027Sphk# 7615027Sphk# Addison-Wesley 7773023Sdes# ISBN 0-201-63357-4 7825478Sjkh# http://www.awl.com/ 7973023Sdes# http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html 8015027Sphk# 8115027Sphk 8291019Scjcsetup_loopback () { 8391019Scjc ############ 8491019Scjc # Only in rare cases do you want to change these rules 8591019Scjc # 8691019Scjc ${fwcmd} add 100 pass all from any to any via lo0 8791019Scjc ${fwcmd} add 200 deny all from any to 127.0.0.0/8 8891019Scjc ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any 8991019Scjc} 9091019Scjc 9151231Ssheldonhif [ -n "${1}" ]; then 9251231Ssheldonh firewall_type="${1}" 9329300Sdannyfi 9429300Sdanny 9515027Sphk############ 9629300Sdanny# Set quiet mode if requested 9751231Ssheldonh# 9851231Ssheldonhcase ${firewall_quiet} in 9951231Ssheldonh[Yy][Ee][Ss]) 10029300Sdanny fwcmd="/sbin/ipfw -q" 10151231Ssheldonh ;; 10251231Ssheldonh*) 10329300Sdanny fwcmd="/sbin/ipfw" 10451231Ssheldonh ;; 10551231Ssheldonhesac 10629300Sdanny 10729300Sdanny############ 10816578Salex# Flush out the list before we begin. 10951231Ssheldonh# 11050357Ssheldonh${fwcmd} -f flush 11116578Salex 112163749Sphksetup_loopback 113163749Sphk 11416578Salex############ 11564244Sru# Network Address Translation. All packets are passed to natd(8) 11664244Sru# before they encounter your remaining rules. The firewall rules 11764244Sru# will then be run again on each packet after translation by natd 11864244Sru# starting at the rule number following the divert rule. 11951231Ssheldonh# 12064244Sru# For ``simple'' firewall type the divert rule should be put to a 12164244Sru# different place to not interfere with address-checking rules. 12273842Sobrien# 12364244Srucase ${firewall_type} in 12465257Sru[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 12564244Sru case ${natd_enable} in 12664244Sru [Yy][Ee][Ss]) 12764244Sru if [ -n "${natd_interface}" ]; then 128152562Sume ${fwcmd} add 50 divert natd ip4 from any to any via ${natd_interface} 12964244Sru fi 13064244Sru ;; 13164244Sru esac 132165648Spiso case ${firewall_nat_enable} in 133165648Spiso [Yy][Ee][Ss]) 134165648Spiso if [ -n "${firewall_nat_interface}" ]; then 135165648Spiso ${fwcmd} nat 123 config if ${firewall_nat_interface} log 136165648Spiso ${fwcmd} add 50 nat 123 ip4 from any to any via ${firewall_nat_interface} 137165648Spiso fi 138165648Spiso ;; 139165648Spiso esac 14051231Ssheldonhesac 14135267Sbrian 14235267Sbrian############ 14315027Sphk# If you just configured ipfw in the kernel as a tool to solve network 14415027Sphk# problems or you just want to disallow some particular kinds of traffic 14551805Smpp# then you will want to change the default policy to open. You can also 14617594Sjkh# do this as your only action by setting the firewall_type to ``open''. 14751231Ssheldonh# 14850357Ssheldonh# ${fwcmd} add 65000 pass all from any to any 14915027Sphk 15015027Sphk 15117594Sjkh# Prototype setups. 15251231Ssheldonh# 15351231Ssheldonhcase ${firewall_type} in 15451231Ssheldonh[Oo][Pp][Ee][Nn]) 15550357Ssheldonh ${fwcmd} add 65000 pass all from any to any 15651231Ssheldonh ;; 15754108Sobrien 15851231Ssheldonh[Cc][Ll][Ii][Ee][Nn][Tt]) 15951231Ssheldonh ############ 16051231Ssheldonh # This is a prototype setup that will protect your system somewhat 16151231Ssheldonh # against people from outside your own network. 16251231Ssheldonh ############ 16329300Sdanny 16451231Ssheldonh # set these to your network and netmask and ip 16556736Srgrimes net="192.0.2.0" 16651231Ssheldonh mask="255.255.255.0" 16756736Srgrimes ip="192.0.2.1" 16817594Sjkh 16951231Ssheldonh # Allow any traffic to or from my own net. 17051231Ssheldonh ${fwcmd} add pass all from ${ip} to ${net}:${mask} 17151231Ssheldonh ${fwcmd} add pass all from ${net}:${mask} to ${ip} 17215027Sphk 17351231Ssheldonh # Allow TCP through if setup succeeded 17451231Ssheldonh ${fwcmd} add pass tcp from any to any established 17515027Sphk 17652873Sru # Allow IP fragments to pass through 17752873Sru ${fwcmd} add pass all from any to any frag 17852873Sru 17951231Ssheldonh # Allow setup of incoming email 180163749Sphk ${fwcmd} add pass tcp from any to me 25 setup 18115027Sphk 18251231Ssheldonh # Allow setup of outgoing TCP connections only 183163749Sphk ${fwcmd} add pass tcp from me to any setup 18415027Sphk 18551231Ssheldonh # Disallow setup of all other TCP connections 18651231Ssheldonh ${fwcmd} add deny tcp from any to any setup 18715027Sphk 18851231Ssheldonh # Allow DNS queries out in the world 189163749Sphk ${fwcmd} add pass udp from me to any 53 keep-state 19015027Sphk 19151231Ssheldonh # Allow NTP queries out in the world 192163749Sphk ${fwcmd} add pass udp from me to any 123 keep-state 19315027Sphk 19451231Ssheldonh # Everything else is denied by default, unless the 19551231Ssheldonh # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 19651231Ssheldonh # config file. 19751231Ssheldonh ;; 19815027Sphk 19951231Ssheldonh[Ss][Ii][Mm][Pp][Ll][Ee]) 20051231Ssheldonh ############ 20151231Ssheldonh # This is a prototype setup for a simple firewall. Configure this 202121881Sru # machine as a DNS and NTP server, and point all the machines 20351231Ssheldonh # on the inside at this machine for those services. 20451231Ssheldonh ############ 20515027Sphk 20651231Ssheldonh # set these to your outside interface network and netmask and ip 20751231Ssheldonh oif="ed0" 20856736Srgrimes onet="192.0.2.0" 20956736Srgrimes omask="255.255.255.240" 21056736Srgrimes oip="192.0.2.1" 21117594Sjkh 21251231Ssheldonh # set these to your inside interface network and netmask and ip 21351231Ssheldonh iif="ed1" 21456736Srgrimes inet="192.0.2.16" 21556736Srgrimes imask="255.255.255.240" 21656736Srgrimes iip="192.0.2.17" 21715027Sphk 21851231Ssheldonh # Stop spoofing 21951231Ssheldonh ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 22051231Ssheldonh ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 22115027Sphk 22251231Ssheldonh # Stop RFC1918 nets on the outside interface 22356736Srgrimes ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 22456736Srgrimes ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 22556736Srgrimes ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 22615027Sphk 22764028Sobrien # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 22864028Sobrien # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 22964028Sobrien # on the outside interface 23056736Srgrimes ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 23156736Srgrimes ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 23256736Srgrimes ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 23356736Srgrimes ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 23456736Srgrimes ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 23556736Srgrimes 23664244Sru # Network Address Translation. This rule is placed here deliberately 23764244Sru # so that it does not interfere with the surrounding address-checking 23864244Sru # rules. If for example one of your internal LAN machines had its IP 23964244Sru # address set to 192.0.2.1 then an incoming packet for it after being 24064244Sru # translated by natd(8) would match the `deny' rule above. Similarly 24164244Sru # an outgoing packet originated from it before being translated would 24264244Sru # match the `deny' rule below. 24364244Sru case ${natd_enable} in 24464244Sru [Yy][Ee][Ss]) 24564244Sru if [ -n "${natd_interface}" ]; then 24664244Sru ${fwcmd} add divert natd all from any to any via ${natd_interface} 24764244Sru fi 24864244Sru ;; 24964244Sru esac 25064244Sru 25164244Sru # Stop RFC1918 nets on the outside interface 25264244Sru ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 25364244Sru ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 25464244Sru ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 25564244Sru 25664244Sru # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 25764244Sru # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 25864244Sru # on the outside interface 25964244Sru ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 26064244Sru ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 26164244Sru ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 26264244Sru ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 26364244Sru ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 26464244Sru 26551231Ssheldonh # Allow TCP through if setup succeeded 26651231Ssheldonh ${fwcmd} add pass tcp from any to any established 26715027Sphk 26852873Sru # Allow IP fragments to pass through 26952873Sru ${fwcmd} add pass all from any to any frag 27052873Sru 27151231Ssheldonh # Allow setup of incoming email 27251231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 25 setup 27315027Sphk 27451231Ssheldonh # Allow access to our DNS 27551231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 53 setup 27652404Sru ${fwcmd} add pass udp from any to ${oip} 53 27752404Sru ${fwcmd} add pass udp from ${oip} 53 to any 27815027Sphk 27951231Ssheldonh # Allow access to our WWW 28051231Ssheldonh ${fwcmd} add pass tcp from any to ${oip} 80 setup 28115027Sphk 28251231Ssheldonh # Reject&Log all setup of incoming connections from the outside 28351231Ssheldonh ${fwcmd} add deny log tcp from any to any in via ${oif} setup 28415027Sphk 28551231Ssheldonh # Allow setup of any other TCP connection 28651231Ssheldonh ${fwcmd} add pass tcp from any to any setup 28715027Sphk 28851231Ssheldonh # Allow DNS queries out in the world 28972772Snsayer ${fwcmd} add pass udp from ${oip} to any 53 keep-state 29015027Sphk 29151231Ssheldonh # Allow NTP queries out in the world 29272772Snsayer ${fwcmd} add pass udp from ${oip} to any 123 keep-state 29315027Sphk 29451231Ssheldonh # Everything else is denied by default, unless the 29551231Ssheldonh # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 29651231Ssheldonh # config file. 29751231Ssheldonh ;; 29815027Sphk 299163749Sphk[Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn]) 300163749Sphk # Configuration: 301163749Sphk # firewall_myservices: List of TCP ports on which this host 302163749Sphk # offers services. 303163749Sphk # firewall_allowservices: List of IPs which has access to 304163749Sphk # $firewall_myservices. 305163749Sphk # firewall_trusted: List of IPs which has full access 306163749Sphk # to this host. Be very carefull 307163749Sphk # when setting this. This option can 308163749Sphk # seriously degrade the level of 309163749Sphk # protection provided by the firewall. 310163749Sphk # firewall_logdeny: Boolean (YES/NO) specifying if the 311163749Sphk # default denied packets should be 312163749Sphk # logged (in /var/log/security). 313163749Sphk # firewall_nologports: List of TCP/UDP ports for which 314163749Sphk # denied incomming packets are not 315163749Sphk # logged. 316163749Sphk 317163749Sphk # Allow packets for which a state has been built. 318163749Sphk ${fwcmd} add check-state 319163749Sphk 320163749Sphk # For services permitted below. 321163749Sphk ${fwcmd} add pass tcp from me to any established 322163749Sphk 323163749Sphk # Allow any connection out, adding state for each. 324163749Sphk ${fwcmd} add pass tcp from me to any setup keep-state 325163749Sphk ${fwcmd} add pass udp from me to any keep-state 326163749Sphk ${fwcmd} add pass icmp from me to any keep-state 327163749Sphk 328163749Sphk # Allow DHCP. 329163749Sphk ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out 330163749Sphk ${fwcmd} add pass udp from any 67 to me 68 in 331163749Sphk ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in 332163749Sphk # Some servers will ping the IP while trying to decide if it's 333163749Sphk # still in use. 334163749Sphk ${fwcmd} add pass icmp from any to any icmptype 8 335163749Sphk 336163749Sphk # Allow "mandatory" ICMP in. 337163749Sphk ${fwcmd} add pass icmp from any to any icmptype 3,4,11 338163749Sphk 339163749Sphk # Add permits for this workstations published services below 340163749Sphk # Only IPs and nets in firewall_allowservices is allowed in. 341163749Sphk # If you really wish to let anyone use services on your 342163749Sphk # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf 343163749Sphk # 344163749Sphk # Note: We don't use keep-state as that would allow DoS of 345163749Sphk # our statetable. 346163749Sphk # You can add 'keep-state' to the lines for slightly 347163749Sphk # better performance if you fell that DoS of your 348163749Sphk # workstation won't be a problem. 349163749Sphk # 350163749Sphk for i in ${firewall_allowservices} ; do 351163749Sphk for j in ${firewall_myservices} ; do 352163749Sphk ${fwcmd} add pass tcp from $i to me $j 353163749Sphk done 354163749Sphk done 355163749Sphk 356163749Sphk # Allow all connections from trusted IPs. 357163749Sphk # Playing with the content of firewall_trusted could seriously 358163749Sphk # degrade the level of protection provided by the firewall. 359163749Sphk for i in ${firewall_trusted} ; do 360163749Sphk ${fwcmd} add pass ip from $i to me 361163749Sphk done 362163749Sphk 363163749Sphk ${fwcmd} add 65000 count ip from any to any 364163749Sphk 365163749Sphk # Drop packets to ports where we don't want logging 366163749Sphk for i in ${firewall_nologports} ; do 367163749Sphk ${fwcmd} add deny { tcp or udp } from any to any $i in 368163749Sphk done 369163749Sphk 370163749Sphk # Broadcasts and muticasts 371163749Sphk ${fwcmd} add deny ip from any to 255.255.255.255 372163749Sphk ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX 373163749Sphk 374163749Sphk # Noise from routers 375163749Sphk ${fwcmd} add deny udp from any to any 520 in 376163749Sphk 377163749Sphk # Noise from webbrowsing. 378163749Sphk # The statefull filter is a bit agressive, and will cause some 379163749Sphk # connection teardowns to be logged. 380163749Sphk ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in 381163749Sphk 382163749Sphk # Deny and (if wanted) log the rest unconditionally. 383163749Sphk log="" 384163749Sphk if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then 385163749Sphk log="log logamount 500" # The default of 100 is too low. 386163749Sphk sysctl net.inet.ip.fw.verbose=1 >/dev/null 387163749Sphk fi 388163749Sphk ${fwcmd} add deny $log ip from any to any 389163749Sphk ;; 390163749Sphk 39191019Scjc[Cc][Ll][Oo][Ss][Ee][Dd]) 392163749Sphk ${fwcmd} add 65000 deny ip from any to any 39391019Scjc ;; 39451231Ssheldonh[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 39551231Ssheldonh ;; 39651231Ssheldonh*) 39759669Sbsd if [ -r "${firewall_type}" ]; then 39857014Spaul ${fwcmd} ${firewall_flags} ${firewall_type} 39951231Ssheldonh fi 40051231Ssheldonh ;; 40151231Ssheldonhesac 402