2 # Copyright (c) 1996 Poul-Henning Kamp
5 # Redistribution and use in source and binary forms, with or without
6 # modification, are permitted provided that the following conditions
8 # 1. Redistributions of source code must retain the above copyright
9 # notice, this list of conditions and the following disclaimer.
10 # 2. Redistributions in binary form must reproduce the above copyright
11 # notice, this list of conditions and the following disclaimer in the
12 # documentation and/or other materials provided with the distribution.
14 # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 # Setup system for firewall service.
33 # Suck in the configuration variables.
34 if [ -z "${source_rc_confs_defined}" ]; then
35 if [ -r /etc/defaults/rc.conf ]; then
36 . /etc/defaults/rc.conf
38 elif [ -r /etc/rc.conf ]; then
44 # Define the firewall type in /etc/rc.conf. Valid values are:
45 # open - will allow anyone in
46 # client - will try to protect just this machine
47 # simple - will try to protect a whole network
48 # closed - totally disables IP services except via lo0 interface
49 # UNKNOWN - disables the loading of firewall rules.
50 # filename - will load the rules in the given filename (full path required)
52 # For ``client'' and ``simple'' the entries below should be customized
57 # If you don't know enough about packet filtering, we suggest that you
58 # take time to read this book:
60 # Building Internet Firewalls, 2nd Edition
61 # Brent Chapman and Elizabeth Zwicky
63 # O'Reilly & Associates, Inc
66 # http://www.oreilly.com/catalog/fire2/
68 # For a more advanced treatment of Internet Security read:
70 # Firewalls & Internet Security
71 # Repelling the wily hacker
72 # William R. Cheswick, Steven M. Bellowin
77 # http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html
82 # Only in rare cases do you want to change these rules
84 ${fwcmd} add 100 pass all from any to any via lo0
85 ${fwcmd} add 200 deny all from any to 127.0.0.0/8
86 ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any
89 if [ -n "${1}" ]; then
94 # Set quiet mode if requested
96 case ${firewall_quiet} in
106 # Flush out the list before we begin.
111 # Network Address Translation. All packets are passed to natd(8)
112 # before they encounter your remaining rules. The firewall rules
113 # will then be run again on each packet after translation by natd
114 # starting at the rule number following the divert rule.
116 # For ``simple'' firewall type the divert rule should be put to a
117 # different place to not interfere with address-checking rules.
119 case ${firewall_type} in
120 [Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt])
121 case ${natd_enable} in
123 if [ -n "${natd_interface}" ]; then
124 ${fwcmd} add 50 divert natd all from any to any via ${natd_interface}
131 # If you just configured ipfw in the kernel as a tool to solve network
132 # problems or you just want to disallow some particular kinds of traffic
133 # then you will want to change the default policy to open. You can also
134 # do this as your only action by setting the firewall_type to ``open''.
136 # ${fwcmd} add 65000 pass all from any to any
141 case ${firewall_type} in
144 ${fwcmd} add 65000 pass all from any to any
147 [Cc][Ll][Ii][Ee][Nn][Tt])
149 # This is a prototype setup that will protect your system somewhat
150 # against people from outside your own network.
153 # set these to your network and netmask and ip
160 # Allow any traffic to or from my own net.
161 ${fwcmd} add pass all from ${ip} to ${net}:${mask}
162 ${fwcmd} add pass all from ${net}:${mask} to ${ip}
164 # Allow TCP through if setup succeeded
165 ${fwcmd} add pass tcp from any to any established
167 # Allow IP fragments to pass through
168 ${fwcmd} add pass all from any to any frag
170 # Allow setup of incoming email
171 ${fwcmd} add pass tcp from any to ${ip} 25 setup
173 # Allow setup of outgoing TCP connections only
174 ${fwcmd} add pass tcp from ${ip} to any setup
176 # Disallow setup of all other TCP connections
177 ${fwcmd} add deny tcp from any to any setup
179 # Allow DNS queries out in the world
180 ${fwcmd} add pass udp from ${ip} to any 53 keep-state
182 # Allow NTP queries out in the world
183 ${fwcmd} add pass udp from ${ip} to any 123 keep-state
185 # Everything else is denied by default, unless the
186 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
190 [Ss][Ii][Mm][Pp][Ll][Ee])
192 # This is a prototype setup for a simple firewall. Configure this
193 # machine as a DNS and NTP server, and point all the machines
194 # on the inside at this machine for those services.
197 # set these to your outside interface network and netmask and ip
200 omask="255.255.255.240"
203 # set these to your inside interface network and netmask and ip
206 imask="255.255.255.240"
212 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif}
213 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif}
215 # Stop RFC1918 nets on the outside interface
216 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif}
217 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif}
218 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif}
220 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
221 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
222 # on the outside interface
223 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif}
224 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif}
225 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif}
226 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif}
227 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif}
229 # Network Address Translation. This rule is placed here deliberately
230 # so that it does not interfere with the surrounding address-checking
231 # rules. If for example one of your internal LAN machines had its IP
232 # address set to 192.0.2.1 then an incoming packet for it after being
233 # translated by natd(8) would match the `deny' rule above. Similarly
234 # an outgoing packet originated from it before being translated would
235 # match the `deny' rule below.
236 case ${natd_enable} in
238 if [ -n "${natd_interface}" ]; then
239 ${fwcmd} add divert natd all from any to any via ${natd_interface}
244 # Stop RFC1918 nets on the outside interface
245 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif}
246 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif}
247 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif}
249 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
250 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
251 # on the outside interface
252 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif}
253 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif}
254 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif}
255 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif}
256 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif}
258 # Allow TCP through if setup succeeded
259 ${fwcmd} add pass tcp from any to any established
261 # Allow IP fragments to pass through
262 ${fwcmd} add pass all from any to any frag
264 # Allow setup of incoming email
265 ${fwcmd} add pass tcp from any to ${oip} 25 setup
267 # Allow access to our DNS
268 ${fwcmd} add pass tcp from any to ${oip} 53 setup
269 ${fwcmd} add pass udp from any to ${oip} 53
270 ${fwcmd} add pass udp from ${oip} 53 to any
272 # Allow access to our WWW
273 ${fwcmd} add pass tcp from any to ${oip} 80 setup
275 # Reject&Log all setup of incoming connections from the outside
276 ${fwcmd} add deny log tcp from any to any in via ${oif} setup
278 # Allow setup of any other TCP connection
279 ${fwcmd} add pass tcp from any to any setup
281 # Allow DNS queries out in the world
282 ${fwcmd} add pass udp from ${oip} to any 53 keep-state
284 # Allow NTP queries out in the world
285 ${fwcmd} add pass udp from ${oip} to any 123 keep-state
287 # Everything else is denied by default, unless the
288 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
292 [Cc][Ll][Oo][Ss][Ee][Dd])
295 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
298 if [ -r "${firewall_type}" ]; then
299 ${fwcmd} ${firewall_flags} ${firewall_type}