rc.firewall revision 88523
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 88523 2001-12-27 05:40:09Z luigi $ 26# 27 28# 29# Setup system for firewall service. 30# 31 32# Suck in the configuration variables. 33if [ -z "${source_rc_confs_defined}" ]; then 34 if [ -r /etc/defaults/rc.conf ]; then 35 . /etc/defaults/rc.conf 36 source_rc_confs 37 elif [ -r /etc/rc.conf ]; then 38 . /etc/rc.conf 39 fi 40fi 41 42############ 43# Define the firewall type in /etc/rc.conf. Valid values are: 44# open - will allow anyone in 45# client - will try to protect just this machine 46# simple - will try to protect a whole network 47# closed - totally disables IP services except via lo0 interface 48# UNKNOWN - disables the loading of firewall rules. 49# filename - will load the rules in the given filename (full path required) 50# 51# For ``client'' and ``simple'' the entries below should be customized 52# appropriately. 53 54############ 55# 56# If you don't know enough about packet filtering, we suggest that you 57# take time to read this book: 58# 59# Building Internet Firewalls, 2nd Edition 60# Brent Chapman and Elizabeth Zwicky 61# 62# O'Reilly & Associates, Inc 63# ISBN 1-56592-871-7 64# http://www.ora.com/ 65# http://www.oreilly.com/catalog/fire2/ 66# 67# For a more advanced treatment of Internet Security read: 68# 69# Firewalls & Internet Security 70# Repelling the wily hacker 71# William R. Cheswick, Steven M. Bellowin 72# 73# Addison-Wesley 74# ISBN 0-201-63357-4 75# http://www.awl.com/ 76# http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html 77# 78 79if [ -n "${1}" ]; then 80 firewall_type="${1}" 81fi 82 83############ 84# Set quiet mode if requested 85# 86case ${firewall_quiet} in 87[Yy][Ee][Ss]) 88 fwcmd="/sbin/ipfw -q" 89 ;; 90*) 91 fwcmd="/sbin/ipfw" 92 ;; 93esac 94 95############ 96# Flush out the list before we begin. 97# 98${fwcmd} -f flush 99 100############ 101# Network Address Translation. All packets are passed to natd(8) 102# before they encounter your remaining rules. The firewall rules 103# will then be run again on each packet after translation by natd 104# starting at the rule number following the divert rule. 105# 106# For ``simple'' firewall type the divert rule should be put to a 107# different place to not interfere with address-checking rules. 108# 109case ${firewall_type} in 110[Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt]) 111 case ${natd_enable} in 112 [Yy][Ee][Ss]) 113 if [ -n "${natd_interface}" ]; then 114 ${fwcmd} add 50 divert natd all from any to any via ${natd_interface} 115 fi 116 ;; 117 esac 118esac 119 120############ 121# If you just configured ipfw in the kernel as a tool to solve network 122# problems or you just want to disallow some particular kinds of traffic 123# then you will want to change the default policy to open. You can also 124# do this as your only action by setting the firewall_type to ``open''. 125# 126# ${fwcmd} add 65000 pass all from any to any 127 128############ 129# Only in rare cases do you want to change these rules 130# 131${fwcmd} add 100 pass all from any to any via lo0 132${fwcmd} add 200 deny all from any to 127.0.0.0/8 133${fwcmd} add 300 deny ip from 127.0.0.0/8 to any 134 135 136# Prototype setups. 137# 138case ${firewall_type} in 139[Oo][Pp][Ee][Nn]) 140 ${fwcmd} add 65000 pass all from any to any 141 ;; 142 143[Cc][Ll][Ii][Ee][Nn][Tt]) 144 ############ 145 # This is a prototype setup that will protect your system somewhat 146 # against people from outside your own network. 147 ############ 148 149 # set these to your network and netmask and ip 150 net="192.0.2.0" 151 mask="255.255.255.0" 152 ip="192.0.2.1" 153 154 # Allow any traffic to or from my own net. 155 ${fwcmd} add pass all from ${ip} to ${net}:${mask} 156 ${fwcmd} add pass all from ${net}:${mask} to ${ip} 157 158 # Allow TCP through if setup succeeded 159 ${fwcmd} add pass tcp from any to any established 160 161 # Allow IP fragments to pass through 162 ${fwcmd} add pass all from any to any frag 163 164 # Allow setup of incoming email 165 ${fwcmd} add pass tcp from any to ${ip} 25 setup 166 167 # Allow setup of outgoing TCP connections only 168 ${fwcmd} add pass tcp from ${ip} to any setup 169 170 # Disallow setup of all other TCP connections 171 ${fwcmd} add deny tcp from any to any setup 172 173 # Allow DNS queries out in the world 174 ${fwcmd} add pass udp from ${ip} to any 53 keep-state 175 176 # Allow NTP queries out in the world 177 ${fwcmd} add pass udp from ${ip} to any 123 keep-state 178 179 # Everything else is denied by default, unless the 180 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 181 # config file. 182 ;; 183 184[Ss][Ii][Mm][Pp][Ll][Ee]) 185 ############ 186 # This is a prototype setup for a simple firewall. Configure this 187 # machine as a named server and ntp server, and point all the machines 188 # on the inside at this machine for those services. 189 ############ 190 191 # set these to your outside interface network and netmask and ip 192 oif="ed0" 193 onet="192.0.2.0" 194 omask="255.255.255.240" 195 oip="192.0.2.1" 196 197 # set these to your inside interface network and netmask and ip 198 iif="ed1" 199 inet="192.0.2.16" 200 imask="255.255.255.240" 201 iip="192.0.2.17" 202 203 # Stop spoofing 204 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif} 205 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif} 206 207 # Stop RFC1918 nets on the outside interface 208 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif} 209 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif} 210 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif} 211 212 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 213 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 214 # on the outside interface 215 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif} 216 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif} 217 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif} 218 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif} 219 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif} 220 221 # Network Address Translation. This rule is placed here deliberately 222 # so that it does not interfere with the surrounding address-checking 223 # rules. If for example one of your internal LAN machines had its IP 224 # address set to 192.0.2.1 then an incoming packet for it after being 225 # translated by natd(8) would match the `deny' rule above. Similarly 226 # an outgoing packet originated from it before being translated would 227 # match the `deny' rule below. 228 case ${natd_enable} in 229 [Yy][Ee][Ss]) 230 if [ -n "${natd_interface}" ]; then 231 ${fwcmd} add divert natd all from any to any via ${natd_interface} 232 fi 233 ;; 234 esac 235 236 # Stop RFC1918 nets on the outside interface 237 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif} 238 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif} 239 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif} 240 241 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1, 242 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E) 243 # on the outside interface 244 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif} 245 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif} 246 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif} 247 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif} 248 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif} 249 250 # Allow TCP through if setup succeeded 251 ${fwcmd} add pass tcp from any to any established 252 253 # Allow IP fragments to pass through 254 ${fwcmd} add pass all from any to any frag 255 256 # Allow setup of incoming email 257 ${fwcmd} add pass tcp from any to ${oip} 25 setup 258 259 # Allow access to our DNS 260 ${fwcmd} add pass tcp from any to ${oip} 53 setup 261 ${fwcmd} add pass udp from any to ${oip} 53 262 ${fwcmd} add pass udp from ${oip} 53 to any 263 264 # Allow access to our WWW 265 ${fwcmd} add pass tcp from any to ${oip} 80 setup 266 267 # Reject&Log all setup of incoming connections from the outside 268 ${fwcmd} add deny log tcp from any to any in via ${oif} setup 269 270 # Allow setup of any other TCP connection 271 ${fwcmd} add pass tcp from any to any setup 272 273 # Allow DNS queries out in the world 274 ${fwcmd} add pass udp from ${oip} to any 53 keep-state 275 276 # Allow NTP queries out in the world 277 ${fwcmd} add pass udp from ${oip} to any 123 keep-state 278 279 # Everything else is denied by default, unless the 280 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel 281 # config file. 282 ;; 283 284[Uu][Nn][Kk][Nn][Oo][Ww][Nn]) 285 ;; 286*) 287 if [ -r "${firewall_type}" ]; then 288 ${fwcmd} ${firewall_flags} ${firewall_type} 289 fi 290 ;; 291esac 292