rc.firewall revision 72772
1# Copyright (c) 1996 Poul-Henning Kamp 2# All rights reserved. 3# 4# Redistribution and use in source and binary forms, with or without 5# modification, are permitted provided that the following conditions 6# are met: 7# 1. Redistributions of source code must retain the above copyright 8# notice, this list of conditions and the following disclaimer. 9# 2. Redistributions in binary form must reproduce the above copyright 10# notice, this list of conditions and the following disclaimer in the 11# documentation and/or other materials provided with the distribution. 12# 13# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23# SUCH DAMAGE. 24# 25# $FreeBSD: head/etc/rc.firewall 72772 2001-02-20 19:54:31Z nsayer $ 26# 27 28# 29# Setup system for firewall service. 30# 31 32# Suck in the configuration variables. 33if [ -r /etc/defaults/rc.conf ]; then 34 . /etc/defaults/rc.conf 35 source_rc_confs 36elif [ -r /etc/rc.conf ]; then 37 . /etc/rc.conf 38fi 39 40############ 41# Define the firewall type in /etc/rc.conf. Valid values are: 42# open - will allow anyone in 43# client - will try to protect just this machine 44# simple - will try to protect a whole network 45# closed - totally disables IP services except via lo0 interface 46# UNKNOWN - disables the loading of firewall rules. 47# filename - will load the rules in the given filename (full path required) 48# 49# For ``client'' and ``simple'' the entries below should be customized 50# appropriately. 51 52############ 53# 54# If you don't know enough about packet filtering, we suggest that you 55# take time to read this book: 56# 57# Building Internet Firewalls 58# Brent Chapman and Elizabeth Zwicky 59# 60# O'Reilly & Associates, Inc 61# ISBN 1-56592-124-0 62# http://www.ora.com/ 63# 64# For a more advanced treatment of Internet Security read: 65# 66# Firewalls & Internet Security 67# Repelling the wily hacker 68# William R. Cheswick, Steven M. Bellowin 69# 70# Addison-Wesley 71# ISBN 0-201-6337-4 72# http://www.awl.com/ 73# 74 75if [ -n "${1}" ]; then 76 firewall_type="${1}" 77fi 78 79############ 80# Set quiet mode if requested 81# 82case ${firewall_quiet} in 83[Yy][Ee][Ss]) 84 fwcmd="/sbin/ipfw -q" 85 ;; 86*) 87 fwcmd="/sbin/ipfw" 88 ;; 89esac 90 91############ 92# Flush out the list before we begin. 93# 94${fwcmd} -f flush 95 96############ 97# Network Address Translation. All packets are passed to natd(8) 98# before they encounter your remaining rules. The firewall rules 99# will then be run again on each packet after translation by natd 100# starting at the rule number following the divert rule. 101# 102# For ``simple'' firewall type the divert rule should be put to a 103# different place to not interfere with address-checking rules. 104# 105case ${firewall_type} in 106[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 107 case ${natd_enable} in 108 [Yy][Ee][Ss]) 109 if [ -n "${natd_interface}" ]; then 110 ${fwcmd} add 50 divert natd all from any to any via ${natd_interface} 111 fi 112 ;; 113 esac 114esac 115 116############ 117# If you just configured ipfw in the kernel as a tool to solve network 118# problems or you just want to disallow some particular kinds of traffic 119# then you will want to change the default policy to open. You can also 120# do this as your only action by setting the firewall_type to ``open''. 121# 122# ${fwcmd} add 65000 pass all from any to any 123 124############ 125# Only in rare cases do you want to change these rules 126# 127${fwcmd} add 100 pass all from any to any via lo0 128${fwcmd} add 200 deny all from any to 127.0.0.0/8 129# If you're using 'options BRIDGE', uncomment the following line to pass ARP 130#${fwcmd} add 300 pass udp from 0.0.0.0 2054 to 0.0.0.0 131 132 133# Prototype setups. 134# 135case ${firewall_type} in 136[Oo][Pp][Ee][Nn]) 137 ${fwcmd} add 65000 pass all from any to any 138 ;; 139 140[Cc][Ll][Ii][Ee][Nn][Tt]) 141 ############ 142 # This is a prototype setup that will protect your system somewhat 143 # against people from outside your own network. 144 ############ 145 146 # set these to your network and netmask and ip 147 net="192.0.2.0" 148 mask="255.255.255.0" 149 ip="192.0.2.1" 150 151 # Allow any traffic to or from my own net. 152 ${fwcmd} add pass all from ${ip} to ${net}:${mask} 153 ${fwcmd} add pass all from ${net}:${mask} to ${ip} 154 155 # Allow TCP through if setup succeeded 156 ${fwcmd} add pass tcp from any to any established 157 158 # Allow IP fragments to pass through 159 ${fwcmd} add pass all from any to any frag 160 161 # Allow setup of incoming email 162 ${fwcmd} add pass tcp from any to ${ip} 25 setup 163 164 # Allow setup of outgoing TCP connections only 165 ${fwcmd} add pass tcp from ${ip} to any setup 166 167 # Disallow setup of all other TCP connections 168 ${fwcmd} add deny tcp from any to any setup 169 170 # Allow DNS queries out in the world 171 ${fwcmd} add pass udp from ${ip} to any 53 keep-state 172 173 # Allow NTP queries out in the world 174 ${fwcmd} add pass udp from ${ip} to any 123 keep-state 175 176 # Everything else is denied by default, unless the 177 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 178 # config file. 179 ;; 180 181[Ss][Ii][Mm][Pp][Ll][Ee]) 182 ############ 183 # This is a prototype setup for a simple firewall. Configure this 184 # machine as a named server and ntp server, and point all the machines 185 # on the inside at this machine for those services. 186 ############ 187 188 # set these to your outside interface network and netmask and ip 189 oif="ed0" 190 onet="192.0.2.0" 191 omask="255.255.255.240" 192 oip="192.0.2.1" 193 194 # set these to your inside interface network and netmask and ip 195 iif="ed1" 196 inet="192.0.2.16" 197 imask="255.255.255.240" 198 iip="192.0.2.17" 199 200 # Stop spoofing 201 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 202 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 203 204 # Stop RFC1918 nets on the outside interface 205 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 206 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 207 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 208 209 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 210 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 211 # on the outside interface 212 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 213 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 214 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 215 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 216 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 217 218 # Network Address Translation. This rule is placed here deliberately 219 # so that it does not interfere with the surrounding address-checking 220 # rules. If for example one of your internal LAN machines had its IP 221 # address set to 192.0.2.1 then an incoming packet for it after being 222 # translated by natd(8) would match the `deny' rule above. Similarly 223 # an outgoing packet originated from it before being translated would 224 # match the `deny' rule below. 225 case ${natd_enable} in 226 [Yy][Ee][Ss]) 227 if [ -n "${natd_interface}" ]; then 228 ${fwcmd} add divert natd all from any to any via ${natd_interface} 229 fi 230 ;; 231 esac 232 233 # Stop RFC1918 nets on the outside interface 234 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 235 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 236 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 237 238 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 239 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 240 # on the outside interface 241 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 242 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 243 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 244 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 245 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 246 247 # Allow TCP through if setup succeeded 248 ${fwcmd} add pass tcp from any to any established 249 250 # Allow IP fragments to pass through 251 ${fwcmd} add pass all from any to any frag 252 253 # Allow setup of incoming email 254 ${fwcmd} add pass tcp from any to ${oip} 25 setup 255 256 # Allow access to our DNS 257 ${fwcmd} add pass tcp from any to ${oip} 53 setup 258 ${fwcmd} add pass udp from any to ${oip} 53 259 ${fwcmd} add pass udp from ${oip} 53 to any 260 261 # Allow access to our WWW 262 ${fwcmd} add pass tcp from any to ${oip} 80 setup 263 264 # Reject&Log all setup of incoming connections from the outside 265 ${fwcmd} add deny log tcp from any to any in via ${oif} setup 266 267 # Allow setup of any other TCP connection 268 ${fwcmd} add pass tcp from any to any setup 269 270 # Allow DNS queries out in the world 271 ${fwcmd} add pass udp from ${oip} to any 53 keep-state 272 273 # Allow NTP queries out in the world 274 ${fwcmd} add pass udp from ${oip} to any 123 keep-state 275 276 # Everything else is denied by default, unless the 277 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 278 # config file. 279 ;; 280 281[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 282 ;; 283*) 284 if [ -r "${firewall_type}" ]; then 285 ${fwcmd} ${firewall_flags} ${firewall_type} 286 fi 287 ;; 288esac 289