rc.firewall revision 73023
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 73023 2001-02-25 11:44:51Z des $ 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, 2nd Edition 58# Brent Chapman and Elizabeth Zwicky 59# 60# O'Reilly & Associates, Inc 61# ISBN 1-56592-871-7 62# http://www.ora.com/ 63# http://www.oreilly.com/catalog/fire2/ 64# 65# For a more advanced treatment of Internet Security read: 66# 67# Firewalls & Internet Security 68# Repelling the wily hacker 69# William R. Cheswick, Steven M. Bellowin 70# 71# Addison-Wesley 72# ISBN 0-201-63357-4 73# http://www.awl.com/ 74# http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html 75# 76 77if [ -n "${1}" ]; then 78 firewall_type="${1}" 79fi 80 81############ 82# Set quiet mode if requested 83# 84case ${firewall_quiet} in 85[Yy][Ee][Ss]) 86 fwcmd="/sbin/ipfw -q" 87 ;; 88*) 89 fwcmd="/sbin/ipfw" 90 ;; 91esac 92 93############ 94# Flush out the list before we begin. 95# 96${fwcmd} -f flush 97 98############ 99# Network Address Translation. All packets are passed to natd(8) 100# before they encounter your remaining rules. The firewall rules 101# will then be run again on each packet after translation by natd 102# starting at the rule number following the divert rule. 103# 104# For ``simple'' firewall type the divert rule should be put to a 105# different place to not interfere with address-checking rules. 106# 107case ${firewall_type} in 108[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 109 case ${natd_enable} in 110 [Yy][Ee][Ss]) 111 if [ -n "${natd_interface}" ]; then 112 ${fwcmd} add 50 divert natd all from any to any via ${natd_interface} 113 fi 114 ;; 115 esac 116esac 117 118############ 119# If you just configured ipfw in the kernel as a tool to solve network 120# problems or you just want to disallow some particular kinds of traffic 121# then you will want to change the default policy to open. You can also 122# do this as your only action by setting the firewall_type to ``open''. 123# 124# ${fwcmd} add 65000 pass all from any to any 125 126############ 127# Only in rare cases do you want to change these rules 128# 129${fwcmd} add 100 pass all from any to any via lo0 130${fwcmd} add 200 deny all from any to 127.0.0.0/8 131# If you're using 'options BRIDGE', uncomment the following line to pass ARP 132#${fwcmd} add 300 pass udp from 0.0.0.0 2054 to 0.0.0.0 133 134 135# Prototype setups. 136# 137case ${firewall_type} in 138[Oo][Pp][Ee][Nn]) 139 ${fwcmd} add 65000 pass all from any to any 140 ;; 141 142[Cc][Ll][Ii][Ee][Nn][Tt]) 143 ############ 144 # This is a prototype setup that will protect your system somewhat 145 # against people from outside your own network. 146 ############ 147 148 # set these to your network and netmask and ip 149 net="192.0.2.0" 150 mask="255.255.255.0" 151 ip="192.0.2.1" 152 153 # Allow any traffic to or from my own net. 154 ${fwcmd} add pass all from ${ip} to ${net}:${mask} 155 ${fwcmd} add pass all from ${net}:${mask} to ${ip} 156 157 # Allow TCP through if setup succeeded 158 ${fwcmd} add pass tcp from any to any established 159 160 # Allow IP fragments to pass through 161 ${fwcmd} add pass all from any to any frag 162 163 # Allow setup of incoming email 164 ${fwcmd} add pass tcp from any to ${ip} 25 setup 165 166 # Allow setup of outgoing TCP connections only 167 ${fwcmd} add pass tcp from ${ip} to any setup 168 169 # Disallow setup of all other TCP connections 170 ${fwcmd} add deny tcp from any to any setup 171 172 # Allow DNS queries out in the world 173 ${fwcmd} add pass udp from ${ip} to any 53 keep-state 174 175 # Allow NTP queries out in the world 176 ${fwcmd} add pass udp from ${ip} to any 123 keep-state 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 ${oip} to any 53 keep-state 274 275 # Allow NTP queries out in the world 276 ${fwcmd} add pass udp from ${oip} to any 123 keep-state 277 278 # Everything else is denied by default, unless the 279 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 280 # config file. 281 ;; 282 283[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 284 ;; 285*) 286 if [ -r "${firewall_type}" ]; then 287 ${fwcmd} ${firewall_flags} ${firewall_type} 288 fi 289 ;; 290esac 291