1 # Copyright (c) 1996 Poul-Henning Kamp
4 # Redistribution and use in source and binary forms, with or without
5 # modification, are permitted provided that the following conditions
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.
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
29 # Setup system for firewall service.
32 # Suck in the configuration variables.
33 if [ -z "${source_rc_confs_defined}" ]; then
34 if [ -r /etc/defaults/rc.conf ]; then
35 . /etc/defaults/rc.conf
37 elif [ -r /etc/rc.conf ]; then
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)
51 # For ``client'' and ``simple'' the entries below should be customized
56 # If you don't know enough about packet filtering, we suggest that you
57 # take time to read this book:
59 # Building Internet Firewalls, 2nd Edition
60 # Brent Chapman and Elizabeth Zwicky
62 # O'Reilly & Associates, Inc
65 # http://www.oreilly.com/catalog/fire2/
67 # For a more advanced treatment of Internet Security read:
69 # Firewalls & Internet Security
70 # Repelling the wily hacker
71 # William R. Cheswick, Steven M. Bellowin
76 # http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html
81 # Only in rare cases do you want to change these rules
83 ${fwcmd} add 100 pass all from any to any via lo0
84 ${fwcmd} add 200 deny all from any to 127.0.0.0/8
85 ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any
88 if [ -n "${1}" ]; then
93 # Set quiet mode if requested
95 case ${firewall_quiet} in
105 # Flush out the list before we begin.
110 # Network Address Translation. All packets are passed to natd(8)
111 # before they encounter your remaining rules. The firewall rules
112 # will then be run again on each packet after translation by natd
113 # starting at the rule number following the divert rule.
115 # For ``simple'' firewall type the divert rule should be put to a
116 # different place to not interfere with address-checking rules.
118 case ${firewall_type} in
119 [Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt])
120 case ${natd_enable} in
122 if [ -n "${natd_interface}" ]; then
123 ${fwcmd} add 50 divert natd all from any to any via ${natd_interface}
130 # If you just configured ipfw in the kernel as a tool to solve network
131 # problems or you just want to disallow some particular kinds of traffic
132 # then you will want to change the default policy to open. You can also
133 # do this as your only action by setting the firewall_type to ``open''.
135 # ${fwcmd} add 65000 pass all from any to any
140 case ${firewall_type} in
143 ${fwcmd} add 65000 pass all from any to any
146 [Cc][Ll][Ii][Ee][Nn][Tt])
148 # This is a prototype setup that will protect your system somewhat
149 # against people from outside your own network.
152 # set these to your network and netmask and ip
159 # Allow any traffic to or from my own net.
160 ${fwcmd} add pass all from ${ip} to ${net}:${mask}
161 ${fwcmd} add pass all from ${net}:${mask} to ${ip}
163 # Allow TCP through if setup succeeded
164 ${fwcmd} add pass tcp from any to any established
166 # Allow IP fragments to pass through
167 ${fwcmd} add pass all from any to any frag
169 # Allow setup of incoming email
170 ${fwcmd} add pass tcp from any to ${ip} 25 setup
172 # Allow setup of outgoing TCP connections only
173 ${fwcmd} add pass tcp from ${ip} to any setup
175 # Disallow setup of all other TCP connections
176 ${fwcmd} add deny tcp from any to any setup
178 # Allow DNS queries out in the world
179 ${fwcmd} add pass udp from ${ip} to any 53 keep-state
181 # Allow NTP queries out in the world
182 ${fwcmd} add pass udp from ${ip} to any 123 keep-state
184 # Everything else is denied by default, unless the
185 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
189 [Ss][Ii][Mm][Pp][Ll][Ee])
191 # This is a prototype setup for a simple firewall. Configure this
192 # machine as a named server and ntp server, and point all the machines
193 # on the inside at this machine for those services.
196 # set these to your outside interface network and netmask and ip
199 omask="255.255.255.240"
202 # set these to your inside interface network and netmask and ip
205 imask="255.255.255.240"
211 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif}
212 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif}
214 # Stop RFC1918 nets on the outside interface
215 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif}
216 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif}
217 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif}
219 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
220 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
221 # on the outside interface
222 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif}
223 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif}
224 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif}
225 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif}
226 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif}
228 # Network Address Translation. This rule is placed here deliberately
229 # so that it does not interfere with the surrounding address-checking
230 # rules. If for example one of your internal LAN machines had its IP
231 # address set to 192.0.2.1 then an incoming packet for it after being
232 # translated by natd(8) would match the `deny' rule above. Similarly
233 # an outgoing packet originated from it before being translated would
234 # match the `deny' rule below.
235 case ${natd_enable} in
237 if [ -n "${natd_interface}" ]; then
238 ${fwcmd} add divert natd all from any to any via ${natd_interface}
243 # Stop RFC1918 nets on the outside interface
244 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif}
245 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif}
246 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif}
248 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
249 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
250 # on the outside interface
251 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif}
252 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif}
253 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif}
254 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif}
255 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif}
257 # Allow TCP through if setup succeeded
258 ${fwcmd} add pass tcp from any to any established
260 # Allow IP fragments to pass through
261 ${fwcmd} add pass all from any to any frag
263 # Allow setup of incoming email
264 ${fwcmd} add pass tcp from any to ${oip} 25 setup
266 # Allow access to our DNS
267 ${fwcmd} add pass tcp from any to ${oip} 53 setup
268 ${fwcmd} add pass udp from any to ${oip} 53
269 ${fwcmd} add pass udp from ${oip} 53 to any
271 # Allow access to our WWW
272 ${fwcmd} add pass tcp from any to ${oip} 80 setup
274 # Reject&Log all setup of incoming connections from the outside
275 ${fwcmd} add deny log tcp from any to any in via ${oif} setup
277 # Allow setup of any other TCP connection
278 ${fwcmd} add pass tcp from any to any setup
280 # Allow DNS queries out in the world
281 ${fwcmd} add pass udp from ${oip} to any 53 keep-state
283 # Allow NTP queries out in the world
284 ${fwcmd} add pass udp from ${oip} to any 123 keep-state
286 # Everything else is denied by default, unless the
287 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
291 [Cc][Ll][Oo][Ss][Ee][Dd])
294 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
297 if [ -r "${firewall_type}" ]; then
298 ${fwcmd} ${firewall_flags} ${firewall_type}