rc.firewall revision 66830
133965Sjdp# Copyright (c) 1996 Poul-Henning Kamp 233965Sjdp# All rights reserved. 333965Sjdp# 433965Sjdp# Redistribution and use in source and binary forms, with or without 533965Sjdp# modification, are permitted provided that the following conditions 633965Sjdp# are met: 733965Sjdp# 1. Redistributions of source code must retain the above copyright 833965Sjdp# notice, this list of conditions and the following disclaimer. 933965Sjdp# 2. Redistributions in binary form must reproduce the above copyright 1033965Sjdp# notice, this list of conditions and the following disclaimer in the 1133965Sjdp# documentation and/or other materials provided with the distribution. 1233965Sjdp# 1333965Sjdp# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1433965Sjdp# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1533965Sjdp# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1633965Sjdp# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1733965Sjdp# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1833965Sjdp# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 1933965Sjdp# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2033965Sjdp# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2133965Sjdp# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2233965Sjdp# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2333965Sjdp# SUCH DAMAGE. 2433965Sjdp# 2533965Sjdp# $FreeBSD: head/etc/rc.firewall 66830 2000-10-08 19:20:36Z obrien $ 2633965Sjdp# 2733965Sjdp 2833965Sjdp# 2933965Sjdp# Setup system for firewall service. 3033965Sjdp# 3133965Sjdp 3233965Sjdp# Suck in the configuration variables. 3333965Sjdpif [ -r /etc/defaults/rc.conf ]; then 3433965Sjdp . /etc/defaults/rc.conf 3533965Sjdp source_rc_confs 3633965Sjdpelif [ -r /etc/rc.conf ]; then 3733965Sjdp . /etc/rc.conf 3833965Sjdpfi 3933965Sjdp 4033965Sjdp############ 4133965Sjdp# Define the firewall type in /etc/rc.conf. Valid values are: 4233965Sjdp# open - will allow anyone in 4333965Sjdp# client - will try to protect just this machine 4433965Sjdp# simple - will try to protect a whole network 4533965Sjdp# closed - totally disables IP services except via lo0 interface 4633965Sjdp# UNKNOWN - disables the loading of firewall rules. 4733965Sjdp# filename - will load the rules in the given filename (full path required) 4833965Sjdp# 4933965Sjdp# For ``client'' and ``simple'' the entries below should be customized 5033965Sjdp# appropriately. 5133965Sjdp 5233965Sjdp############ 5333965Sjdp# 5433965Sjdp# If you don't know enough about packet filtering, we suggest that you 5533965Sjdp# take time to read this book: 5633965Sjdp# 5733965Sjdp# Building Internet Firewalls 5833965Sjdp# Brent Chapman and Elizabeth Zwicky 5933965Sjdp# 6033965Sjdp# O'Reilly & Associates, Inc 6133965Sjdp# ISBN 1-56592-124-0 6233965Sjdp# http://www.ora.com/ 6333965Sjdp# 6433965Sjdp# For a more advanced treatment of Internet Security read: 6533965Sjdp# 6633965Sjdp# Firewalls & Internet Security 6733965Sjdp# Repelling the wily hacker 6833965Sjdp# William R. Cheswick, Steven M. Bellowin 6933965Sjdp# 7033965Sjdp# Addison-Wesley 7133965Sjdp# ISBN 0-201-6337-4 7233965Sjdp# http://www.awl.com/ 7333965Sjdp# 7433965Sjdp 7533965Sjdpif [ -n "${1}" ]; then 7633965Sjdp firewall_type="${1}" 7733965Sjdpfi 7833965Sjdp 7933965Sjdp############ 8033965Sjdp# Set quiet mode if requested 8133965Sjdp# 8233965Sjdpcase ${firewall_quiet} in 8333965Sjdp[Yy][Ee][Ss]) 8433965Sjdp fwcmd="/sbin/ipfw -q" 8533965Sjdp ;; 8633965Sjdp*) 8733965Sjdp fwcmd="/sbin/ipfw" 8833965Sjdp ;; 8933965Sjdpesac 9033965Sjdp 9133965Sjdp############ 9233965Sjdp# Flush out the list before we begin. 9333965Sjdp# 9433965Sjdp${fwcmd} -f flush 9533965Sjdp 9633965Sjdp############ 9733965Sjdp# Network Address Translation. All packets are passed to natd(8) 9833965Sjdp# before they encounter your remaining rules. The firewall rules 9933965Sjdp# will then be run again on each packet after translation by natd 10033965Sjdp# starting at the rule number following the divert rule. 10133965Sjdp# 10233965Sjdp# For ``simple'' firewall type the divert rule should be put to a 10333965Sjdp# different place to not interfere with address-checking rules. 10433965Sjdp# 10533965Sjdpcase ${firewall_type} in 10633965Sjdp[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 10733965Sjdp case ${natd_enable} in 10833965Sjdp [Yy][Ee][Ss]) 10933965Sjdp if [ -n "${natd_interface}" ]; then 11033965Sjdp ${fwcmd} add 50 divert natd all from any to any via ${natd_interface} 11133965Sjdp fi 11233965Sjdp ;; 11333965Sjdp esac 11433965Sjdpesac 11533965Sjdp 11633965Sjdp############ 11733965Sjdp# If you just configured ipfw in the kernel as a tool to solve network 11833965Sjdp# problems or you just want to disallow some particular kinds of traffic 11933965Sjdp# then you will want to change the default policy to open. You can also 12033965Sjdp# do this as your only action by setting the firewall_type to ``open''. 12133965Sjdp# 12233965Sjdp# ${fwcmd} add 65000 pass all from any to any 12333965Sjdp 12433965Sjdp############ 12533965Sjdp# Only in rare cases do you want to change these rules 12633965Sjdp# 12733965Sjdp${fwcmd} add 100 pass all from any to any via lo0 12833965Sjdp${fwcmd} add 200 deny all from any to 127.0.0.0/8 12933965Sjdp# If you're using 'options BRIDGE', uncomment the following line to pass ARP 13033965Sjdp#${fwcmd} add 300 pass udp from 0.0.0.0 2054 to 0.0.0.0 13133965Sjdp 13233965Sjdp 13333965Sjdp# Prototype setups. 13433965Sjdp# 13533965Sjdpcase ${firewall_type} in 13633965Sjdp[Oo][Pp][Ee][Nn]) 13733965Sjdp ${fwcmd} add 65000 pass all from any to any 13833965Sjdp ;; 13933965Sjdp 14033965Sjdp[Cc][Ll][Ii][Ee][Nn][Tt]) 14133965Sjdp ############ 14233965Sjdp # This is a prototype setup that will protect your system somewhat 14333965Sjdp # against people from outside your own network. 14433965Sjdp ############ 14533965Sjdp 14633965Sjdp # set these to your network and netmask and ip 14733965Sjdp net="192.0.2.0" 14833965Sjdp mask="255.255.255.0" 14933965Sjdp ip="192.0.2.1" 15033965Sjdp 15133965Sjdp # Allow any traffic to or from my own net. 15233965Sjdp ${fwcmd} add pass all from ${ip} to ${net}:${mask} 15333965Sjdp ${fwcmd} add pass all from ${net}:${mask} to ${ip} 15433965Sjdp 15533965Sjdp # Allow TCP through if setup succeeded 15633965Sjdp ${fwcmd} add pass tcp from any to any established 15733965Sjdp 15833965Sjdp # 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 any 53 to ${ip} 172 ${fwcmd} add pass udp from ${ip} to any 53 173 174 # Allow NTP queries out in the world 175 ${fwcmd} add pass udp from any 123 to ${ip} 176 ${fwcmd} add pass udp from ${ip} to any 123 177 178 # Everything else is denied by default, unless the 179 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 180 # config file. 181 ;; 182 183[Ss][Ii][Mm][Pp][Ll][Ee]) 184 ############ 185 # This is a prototype setup for a simple firewall. Configure this 186 # machine as a named server and ntp server, and point all the machines 187 # on the inside at this machine for those services. 188 ############ 189 190 # set these to your outside interface network and netmask and ip 191 oif="ed0" 192 onet="192.0.2.0" 193 omask="255.255.255.240" 194 oip="192.0.2.1" 195 196 # set these to your inside interface network and netmask and ip 197 iif="ed1" 198 inet="192.0.2.16" 199 imask="255.255.255.240" 200 iip="192.0.2.17" 201 202 # Stop spoofing 203 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 204 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 205 206 # Stop RFC1918 nets on the outside interface 207 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 208 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 209 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 210 211 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 212 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 213 # on the outside interface 214 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 215 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 216 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 217 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 218 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 219 220 # Network Address Translation. This rule is placed here deliberately 221 # so that it does not interfere with the surrounding address-checking 222 # rules. If for example one of your internal LAN machines had its IP 223 # address set to 192.0.2.1 then an incoming packet for it after being 224 # translated by natd(8) would match the `deny' rule above. Similarly 225 # an outgoing packet originated from it before being translated would 226 # match the `deny' rule below. 227 case ${natd_enable} in 228 [Yy][Ee][Ss]) 229 if [ -n "${natd_interface}" ]; then 230 ${fwcmd} add divert natd all from any to any via ${natd_interface} 231 fi 232 ;; 233 esac 234 235 # Stop RFC1918 nets on the outside interface 236 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 237 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 238 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 239 240 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 241 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 242 # on the outside interface 243 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 244 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 245 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 246 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 247 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 248 249 # Allow TCP through if setup succeeded 250 ${fwcmd} add pass tcp from any to any established 251 252 # Allow IP fragments to pass through 253 ${fwcmd} add pass all from any to any frag 254 255 # Allow setup of incoming email 256 ${fwcmd} add pass tcp from any to ${oip} 25 setup 257 258 # Allow access to our DNS 259 ${fwcmd} add pass tcp from any to ${oip} 53 setup 260 ${fwcmd} add pass udp from any to ${oip} 53 261 ${fwcmd} add pass udp from ${oip} 53 to any 262 263 # Allow access to our WWW 264 ${fwcmd} add pass tcp from any to ${oip} 80 setup 265 266 # Reject&Log all setup of incoming connections from the outside 267 ${fwcmd} add deny log tcp from any to any in via ${oif} setup 268 269 # Allow setup of any other TCP connection 270 ${fwcmd} add pass tcp from any to any setup 271 272 # Allow DNS queries out in the world 273 ${fwcmd} add pass udp from any 53 to ${oip} 274 ${fwcmd} add pass udp from ${oip} to any 53 275 276 # Allow NTP queries out in the world 277 ${fwcmd} add pass udp from any 123 to ${oip} 278 ${fwcmd} add pass udp from ${oip} to any 123 279 280 # Everything else is denied by default, unless the 281 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 282 # config file. 283 ;; 284 285[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 286 ;; 287*) 288 if [ -r "${firewall_type}" ]; then 289 ${fwcmd} ${firewall_flags} ${firewall_type} 290 fi 291 ;; 292esac 293