rc.firewall revision 181760
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 181760 2008-08-15 18:58:15Z jhb $ 2766830Sobrien# 2815027Sphk 2966830Sobrien# 30168384Srwatson# Setup system for ipfw(4) 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# 72175244Smaxim# Firewalls and Internet Security: Repelling the Wily Hacker, 2nd Edition 73175244Smaxim# William R. Cheswick, Steven M. Bellowin, Aviel D. Rubin 7415027Sphk# 75175244Smaxim# Addison-Wesley / Prentice Hall 76175244Smaxim# ISBN 0-201-63466-X 77175244Smaxim# http://www.pearsonhighered.com/ 78175244Smaxim# http://www.pearsonhighered.com/educator/academic/product/0,3110,020163466X,00.html 7915027Sphk# 8015027Sphk 8191019Scjcsetup_loopback () { 8291019Scjc ############ 8391019Scjc # Only in rare cases do you want to change these rules 8491019Scjc # 8591019Scjc ${fwcmd} add 100 pass all from any to any via lo0 8691019Scjc ${fwcmd} add 200 deny all from any to 127.0.0.0/8 8791019Scjc ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any 8891019Scjc} 8991019Scjc 9051231Ssheldonhif [ -n "${1}" ]; then 9151231Ssheldonh firewall_type="${1}" 9229300Sdannyfi 9329300Sdanny 9415027Sphk############ 9529300Sdanny# Set quiet mode if requested 9651231Ssheldonh# 9751231Ssheldonhcase ${firewall_quiet} in 9851231Ssheldonh[Yy][Ee][Ss]) 9929300Sdanny fwcmd="/sbin/ipfw -q" 10051231Ssheldonh ;; 10151231Ssheldonh*) 10229300Sdanny fwcmd="/sbin/ipfw" 10351231Ssheldonh ;; 10451231Ssheldonhesac 10529300Sdanny 10629300Sdanny############ 10716578Salex# Flush out the list before we begin. 10851231Ssheldonh# 10950357Ssheldonh${fwcmd} -f flush 11016578Salex 111163749Sphksetup_loopback 112163749Sphk 11316578Salex############ 11464244Sru# Network Address Translation. All packets are passed to natd(8) 11564244Sru# before they encounter your remaining rules. The firewall rules 11664244Sru# will then be run again on each packet after translation by natd 11764244Sru# starting at the rule number following the divert rule. 11851231Ssheldonh# 11964244Sru# For ``simple'' firewall type the divert rule should be put to a 12064244Sru# different place to not interfere with address-checking rules. 12173842Sobrien# 12264244Srucase ${firewall_type} in 12365257Sru[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 12464244Sru case ${natd_enable} in 12564244Sru [Yy][Ee][Ss]) 12664244Sru if [ -n "${natd_interface}" ]; then 127152562Sume ${fwcmd} add 50 divert natd ip4 from any to any via ${natd_interface} 12864244Sru fi 12964244Sru ;; 13064244Sru esac 131165648Spiso case ${firewall_nat_enable} in 132165648Spiso [Yy][Ee][Ss]) 133165648Spiso if [ -n "${firewall_nat_interface}" ]; then 134175522Srafan if echo "${firewall_nat_interface}" | \ 135175522Srafan grep -q -E '^[0-9]+(\.[0-9]+){0,3}$'; then 136175522Srafan firewall_nat_flags="ip ${firewall_nat_interface} ${firewall_nat_flags}" 137175522Srafan else 138175522Srafan firewall_nat_flags="if ${firewall_nat_interface} ${firewall_nat_flags}" 139175522Srafan fi 140175522Srafan ${fwcmd} nat 123 config log ${firewall_nat_flags} 141165648Spiso ${fwcmd} add 50 nat 123 ip4 from any to any via ${firewall_nat_interface} 142165648Spiso fi 143165648Spiso ;; 144165648Spiso esac 14551231Ssheldonhesac 14635267Sbrian 14735267Sbrian############ 14815027Sphk# If you just configured ipfw in the kernel as a tool to solve network 14915027Sphk# problems or you just want to disallow some particular kinds of traffic 15051805Smpp# then you will want to change the default policy to open. You can also 15117594Sjkh# do this as your only action by setting the firewall_type to ``open''. 15251231Ssheldonh# 15350357Ssheldonh# ${fwcmd} add 65000 pass all from any to any 15415027Sphk 15515027Sphk 15617594Sjkh# Prototype setups. 15751231Ssheldonh# 15851231Ssheldonhcase ${firewall_type} in 15951231Ssheldonh[Oo][Pp][Ee][Nn]) 16050357Ssheldonh ${fwcmd} add 65000 pass all from any to any 16151231Ssheldonh ;; 16254108Sobrien 16351231Ssheldonh[Cc][Ll][Ii][Ee][Nn][Tt]) 16451231Ssheldonh ############ 16551231Ssheldonh # This is a prototype setup that will protect your system somewhat 16651231Ssheldonh # against people from outside your own network. 16751231Ssheldonh ############ 16829300Sdanny 16951231Ssheldonh # set these to your network and netmask and ip 17056736Srgrimes net="192.0.2.0" 17151231Ssheldonh mask="255.255.255.0" 17217594Sjkh 173179598Skeramida # Allow limited broadcast traffic from my own net. 174179598Skeramida ${fwcmd} add pass all from ${net}:${mask} to 255.255.255.255 175179598Skeramida 17651231Ssheldonh # Allow any traffic to or from my own net. 177181760Sjhb ${fwcmd} add pass all from me to ${net}:${mask} 178181760Sjhb ${fwcmd} add pass all from ${net}:${mask} to me 17915027Sphk 18051231Ssheldonh # Allow TCP through if setup succeeded 18151231Ssheldonh ${fwcmd} add pass tcp from any to any established 18215027Sphk 18352873Sru # Allow IP fragments to pass through 18452873Sru ${fwcmd} add pass all from any to any frag 18552873Sru 18651231Ssheldonh # Allow setup of incoming email 187163749Sphk ${fwcmd} add pass tcp from any to me 25 setup 18815027Sphk 18951231Ssheldonh # Allow setup of outgoing TCP connections only 190163749Sphk ${fwcmd} add pass tcp from me to any setup 19115027Sphk 19251231Ssheldonh # Disallow setup of all other TCP connections 19351231Ssheldonh ${fwcmd} add deny tcp from any to any setup 19415027Sphk 19551231Ssheldonh # Allow DNS queries out in the world 196163749Sphk ${fwcmd} add pass udp from me to any 53 keep-state 19715027Sphk 19851231Ssheldonh # Allow NTP queries out in the world 199163749Sphk ${fwcmd} add pass udp from me to any 123 keep-state 20015027Sphk 20151231Ssheldonh # Everything else is denied by default, unless the 20251231Ssheldonh # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 20351231Ssheldonh # config file. 20451231Ssheldonh ;; 20515027Sphk 20651231Ssheldonh[Ss][Ii][Mm][Pp][Ll][Ee]) 20751231Ssheldonh ############ 20851231Ssheldonh # This is a prototype setup for a simple firewall. Configure this 209121881Sru # machine as a DNS and NTP server, and point all the machines 21051231Ssheldonh # on the inside at this machine for those services. 21151231Ssheldonh ############ 21215027Sphk 21351231Ssheldonh # set these to your outside interface network and netmask and ip 21451231Ssheldonh oif="ed0" 21556736Srgrimes onet="192.0.2.0" 21656736Srgrimes omask="255.255.255.240" 21717594Sjkh 21851231Ssheldonh # set these to your inside interface network and netmask and ip 21951231Ssheldonh iif="ed1" 22056736Srgrimes inet="192.0.2.16" 22156736Srgrimes imask="255.255.255.240" 22215027Sphk 22351231Ssheldonh # Stop spoofing 22451231Ssheldonh ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 22551231Ssheldonh ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 22615027Sphk 22751231Ssheldonh # Stop RFC1918 nets on the outside interface 22856736Srgrimes ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 22956736Srgrimes ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 23056736Srgrimes ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 23115027Sphk 23264028Sobrien # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 23364028Sobrien # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 23464028Sobrien # on the outside interface 23556736Srgrimes ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 23656736Srgrimes ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 23756736Srgrimes ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 23856736Srgrimes ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 23956736Srgrimes ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 24056736Srgrimes 24164244Sru # Network Address Translation. This rule is placed here deliberately 24264244Sru # so that it does not interfere with the surrounding address-checking 24364244Sru # rules. If for example one of your internal LAN machines had its IP 24464244Sru # address set to 192.0.2.1 then an incoming packet for it after being 24564244Sru # translated by natd(8) would match the `deny' rule above. Similarly 24664244Sru # an outgoing packet originated from it before being translated would 24764244Sru # match the `deny' rule below. 24864244Sru case ${natd_enable} in 24964244Sru [Yy][Ee][Ss]) 25064244Sru if [ -n "${natd_interface}" ]; then 25164244Sru ${fwcmd} add divert natd all from any to any via ${natd_interface} 25264244Sru fi 25364244Sru ;; 25464244Sru esac 25564244Sru 25664244Sru # Stop RFC1918 nets on the outside interface 25764244Sru ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 25864244Sru ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 25964244Sru ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 26064244Sru 26164244Sru # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 26264244Sru # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 26364244Sru # on the outside interface 26464244Sru ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 26564244Sru ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 26664244Sru ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 26764244Sru ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 26864244Sru ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 26964244Sru 27051231Ssheldonh # Allow TCP through if setup succeeded 27151231Ssheldonh ${fwcmd} add pass tcp from any to any established 27215027Sphk 27352873Sru # Allow IP fragments to pass through 27452873Sru ${fwcmd} add pass all from any to any frag 27552873Sru 27651231Ssheldonh # Allow setup of incoming email 277181760Sjhb ${fwcmd} add pass tcp from any to me 25 setup 27815027Sphk 27951231Ssheldonh # Allow access to our DNS 280181760Sjhb ${fwcmd} add pass tcp from any to me 53 setup 281181760Sjhb ${fwcmd} add pass udp from any to me 53 282181760Sjhb ${fwcmd} add pass udp from me 53 to any 28315027Sphk 28451231Ssheldonh # Allow access to our WWW 285181760Sjhb ${fwcmd} add pass tcp from any to me 80 setup 28615027Sphk 28751231Ssheldonh # Reject&Log all setup of incoming connections from the outside 28851231Ssheldonh ${fwcmd} add deny log tcp from any to any in via ${oif} setup 28915027Sphk 29051231Ssheldonh # Allow setup of any other TCP connection 29151231Ssheldonh ${fwcmd} add pass tcp from any to any setup 29215027Sphk 29351231Ssheldonh # Allow DNS queries out in the world 294181760Sjhb ${fwcmd} add pass udp from me to any 53 keep-state 29515027Sphk 29651231Ssheldonh # Allow NTP queries out in the world 297181760Sjhb ${fwcmd} add pass udp from me to any 123 keep-state 29815027Sphk 29951231Ssheldonh # Everything else is denied by default, unless the 30051231Ssheldonh # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 30151231Ssheldonh # config file. 30251231Ssheldonh ;; 30315027Sphk 304163749Sphk[Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn]) 305163749Sphk # Configuration: 306163749Sphk # firewall_myservices: List of TCP ports on which this host 307163749Sphk # offers services. 308163749Sphk # firewall_allowservices: List of IPs which has access to 309163749Sphk # $firewall_myservices. 310163749Sphk # firewall_trusted: List of IPs which has full access 311163749Sphk # to this host. Be very carefull 312163749Sphk # when setting this. This option can 313163749Sphk # seriously degrade the level of 314163749Sphk # protection provided by the firewall. 315163749Sphk # firewall_logdeny: Boolean (YES/NO) specifying if the 316163749Sphk # default denied packets should be 317163749Sphk # logged (in /var/log/security). 318163749Sphk # firewall_nologports: List of TCP/UDP ports for which 319163749Sphk # denied incomming packets are not 320163749Sphk # logged. 321163749Sphk 322163749Sphk # Allow packets for which a state has been built. 323163749Sphk ${fwcmd} add check-state 324163749Sphk 325163749Sphk # For services permitted below. 326163749Sphk ${fwcmd} add pass tcp from me to any established 327163749Sphk 328163749Sphk # Allow any connection out, adding state for each. 329163749Sphk ${fwcmd} add pass tcp from me to any setup keep-state 330163749Sphk ${fwcmd} add pass udp from me to any keep-state 331163749Sphk ${fwcmd} add pass icmp from me to any keep-state 332163749Sphk 333163749Sphk # Allow DHCP. 334163749Sphk ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out 335163749Sphk ${fwcmd} add pass udp from any 67 to me 68 in 336163749Sphk ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in 337163749Sphk # Some servers will ping the IP while trying to decide if it's 338163749Sphk # still in use. 339163749Sphk ${fwcmd} add pass icmp from any to any icmptype 8 340163749Sphk 341163749Sphk # Allow "mandatory" ICMP in. 342163749Sphk ${fwcmd} add pass icmp from any to any icmptype 3,4,11 343163749Sphk 344163749Sphk # Add permits for this workstations published services below 345163749Sphk # Only IPs and nets in firewall_allowservices is allowed in. 346163749Sphk # If you really wish to let anyone use services on your 347163749Sphk # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf 348163749Sphk # 349163749Sphk # Note: We don't use keep-state as that would allow DoS of 350163749Sphk # our statetable. 351163749Sphk # You can add 'keep-state' to the lines for slightly 352163749Sphk # better performance if you fell that DoS of your 353163749Sphk # workstation won't be a problem. 354163749Sphk # 355163749Sphk for i in ${firewall_allowservices} ; do 356163749Sphk for j in ${firewall_myservices} ; do 357163749Sphk ${fwcmd} add pass tcp from $i to me $j 358163749Sphk done 359163749Sphk done 360163749Sphk 361163749Sphk # Allow all connections from trusted IPs. 362163749Sphk # Playing with the content of firewall_trusted could seriously 363163749Sphk # degrade the level of protection provided by the firewall. 364163749Sphk for i in ${firewall_trusted} ; do 365163749Sphk ${fwcmd} add pass ip from $i to me 366163749Sphk done 367163749Sphk 368163749Sphk ${fwcmd} add 65000 count ip from any to any 369163749Sphk 370163749Sphk # Drop packets to ports where we don't want logging 371163749Sphk for i in ${firewall_nologports} ; do 372163749Sphk ${fwcmd} add deny { tcp or udp } from any to any $i in 373163749Sphk done 374163749Sphk 375163749Sphk # Broadcasts and muticasts 376163749Sphk ${fwcmd} add deny ip from any to 255.255.255.255 377163749Sphk ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX 378163749Sphk 379163749Sphk # Noise from routers 380163749Sphk ${fwcmd} add deny udp from any to any 520 in 381163749Sphk 382163749Sphk # Noise from webbrowsing. 383163749Sphk # The statefull filter is a bit agressive, and will cause some 384163749Sphk # connection teardowns to be logged. 385163749Sphk ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in 386163749Sphk 387163749Sphk # Deny and (if wanted) log the rest unconditionally. 388163749Sphk log="" 389163749Sphk if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then 390163749Sphk log="log logamount 500" # The default of 100 is too low. 391163749Sphk sysctl net.inet.ip.fw.verbose=1 >/dev/null 392163749Sphk fi 393163749Sphk ${fwcmd} add deny $log ip from any to any 394163749Sphk ;; 395163749Sphk 39691019Scjc[Cc][Ll][Oo][Ss][Ee][Dd]) 397163749Sphk ${fwcmd} add 65000 deny ip from any to any 39891019Scjc ;; 39951231Ssheldonh[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 40051231Ssheldonh ;; 40151231Ssheldonh*) 40259669Sbsd if [ -r "${firewall_type}" ]; then 40357014Spaul ${fwcmd} ${firewall_flags} ${firewall_type} 40451231Ssheldonh fi 40551231Ssheldonh ;; 40651231Ssheldonhesac 407