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 "${source_rc_confs_defined}" ]; then
34 if [ -r /etc/defaults/rc.conf ]; then
35 . /etc/defaults/rc.conf
37 elif [ -r /etc/rc.conf ]; then
43 # Define the firewall type in /etc/rc.conf. Valid values are:
44 # open - will allow anyone in
45 # client - will try to protect just this machine
46 # simple - will try to protect a whole network
47 # closed - totally disables IP services except via lo0 interface
48 # UNKNOWN - disables the loading of firewall rules.
49 # filename - will load the rules in the given filename (full path required)
51 # For ``client'' and ``simple'' the entries below should be customized
56 # If you don't know enough about packet filtering, we suggest that you
57 # take time to read this book:
59 # Building Internet Firewalls, 2nd Edition
60 # Brent Chapman and Elizabeth Zwicky
62 # O'Reilly & Associates, Inc
65 # http://www.oreilly.com/catalog/fire2/
67 # For a more advanced treatment of Internet Security read:
69 # Firewalls & Internet Security
70 # Repelling the wily hacker
71 # William R. Cheswick, Steven M. Bellowin
76 # http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html
79 if [ -n "${1}" ]; then
84 # Set quiet mode if requested
86 case ${firewall_quiet} in
96 # Flush out the list before we begin.
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.
106 # For ``simple'' firewall type the divert rule should be put to a
107 # different place to not interfere with address-checking rules.
109 case ${firewall_type} in
110 [Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt])
111 case ${natd_enable} in
113 if [ -n "${natd_interface}" ]; then
114 ${fwcmd} add 50 divert natd all from any to any via ${natd_interface}
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''.
126 # ${fwcmd} add 65000 pass all from any to any
129 # Only in rare cases do you want to change these rules
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 ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any
134 # If you're using 'options BRIDGE', uncomment the following line to pass ARP
135 #${fwcmd} add 400 pass udp from 0.0.0.0 2054 to 0.0.0.0
140 case ${firewall_type} in
142 ${fwcmd} add 65000 pass all from any to any
145 [Cc][Ll][Ii][Ee][Nn][Tt])
147 # This is a prototype setup that will protect your system somewhat
148 # against people from outside your own network.
151 # set these to your network and netmask and ip
156 # Allow any traffic to or from my own net.
157 ${fwcmd} add pass all from ${ip} to ${net}:${mask}
158 ${fwcmd} add pass all from ${net}:${mask} to ${ip}
160 # Allow TCP through if setup succeeded
161 ${fwcmd} add pass tcp from any to any established
163 # Allow IP fragments to pass through
164 ${fwcmd} add pass all from any to any frag
166 # Allow setup of incoming email
167 ${fwcmd} add pass tcp from any to ${ip} 25 setup
169 # Allow setup of outgoing TCP connections only
170 ${fwcmd} add pass tcp from ${ip} to any setup
172 # Disallow setup of all other TCP connections
173 ${fwcmd} add deny tcp from any to any setup
175 # Allow DNS queries out in the world
176 ${fwcmd} add pass udp from ${ip} to any 53 keep-state
178 # Allow NTP queries out in the world
179 ${fwcmd} add pass udp from ${ip} to any 123 keep-state
181 # Everything else is denied by default, unless the
182 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
186 [Ss][Ii][Mm][Pp][Ll][Ee])
188 # This is a prototype setup for a simple firewall. Configure this
189 # machine as a named server and ntp server, and point all the machines
190 # on the inside at this machine for those services.
193 # set these to your outside interface network and netmask and ip
196 omask="255.255.255.240"
199 # set these to your inside interface network and netmask and ip
202 imask="255.255.255.240"
206 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif}
207 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif}
209 # Stop RFC1918 nets on the outside interface
210 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif}
211 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif}
212 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif}
214 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
215 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
216 # on the outside interface
217 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif}
218 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif}
219 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif}
220 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif}
221 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif}
223 # Network Address Translation. This rule is placed here deliberately
224 # so that it does not interfere with the surrounding address-checking
225 # rules. If for example one of your internal LAN machines had its IP
226 # address set to 192.0.2.1 then an incoming packet for it after being
227 # translated by natd(8) would match the `deny' rule above. Similarly
228 # an outgoing packet originated from it before being translated would
229 # match the `deny' rule below.
230 case ${natd_enable} in
232 if [ -n "${natd_interface}" ]; then
233 ${fwcmd} add divert natd all from any to any via ${natd_interface}
238 # Stop RFC1918 nets on the outside interface
239 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif}
240 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif}
241 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif}
243 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
244 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
245 # on the outside interface
246 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif}
247 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif}
248 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif}
249 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif}
250 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif}
252 # Allow TCP through if setup succeeded
253 ${fwcmd} add pass tcp from any to any established
255 # Allow IP fragments to pass through
256 ${fwcmd} add pass all from any to any frag
258 # Allow setup of incoming email
259 ${fwcmd} add pass tcp from any to ${oip} 25 setup
261 # Allow access to our DNS
262 ${fwcmd} add pass tcp from any to ${oip} 53 setup
263 ${fwcmd} add pass udp from any to ${oip} 53
264 ${fwcmd} add pass udp from ${oip} 53 to any
266 # Allow access to our WWW
267 ${fwcmd} add pass tcp from any to ${oip} 80 setup
269 # Reject&Log all setup of incoming connections from the outside
270 ${fwcmd} add deny log tcp from any to any in via ${oif} setup
272 # Allow setup of any other TCP connection
273 ${fwcmd} add pass tcp from any to any setup
275 # Allow DNS queries out in the world
276 ${fwcmd} add pass udp from ${oip} to any 53 keep-state
278 # Allow NTP queries out in the world
279 ${fwcmd} add pass udp from ${oip} to any 123 keep-state
281 # Everything else is denied by default, unless the
282 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
286 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
289 if [ -r "${firewall_type}" ]; then
290 ${fwcmd} ${firewall_flags} ${firewall_type}