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 ipfw(4) 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 # workstation - will try to protect just this machine using statefull
50 # firewalling. See below for rc.conf variables used
51 # UNKNOWN - disables the loading of firewall rules.
52 # filename - will load the rules in the given filename (full path required)
54 # For ``client'' and ``simple'' the entries below should be customized
59 # If you don't know enough about packet filtering, we suggest that you
60 # take time to read this book:
62 # Building Internet Firewalls, 2nd Edition
63 # Brent Chapman and Elizabeth Zwicky
65 # O'Reilly & Associates, Inc
68 # http://www.oreilly.com/catalog/fire2/
70 # For a more advanced treatment of Internet Security read:
72 # Firewalls & Internet Security
73 # Repelling the wily hacker
74 # William R. Cheswick, Steven M. Bellowin
79 # http://www.awlonline.com/product/0%2C2627%2C0201633574%2C00.html
84 # Only in rare cases do you want to change these rules
86 ${fwcmd} add 100 pass all from any to any via lo0
87 ${fwcmd} add 200 deny all from any to 127.0.0.0/8
88 ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any
91 if [ -n "${1}" ]; then
96 # Set quiet mode if requested
98 case ${firewall_quiet} in
100 fwcmd="/sbin/ipfw -q"
108 # Flush out the list before we begin.
115 # Network Address Translation. All packets are passed to natd(8)
116 # before they encounter your remaining rules. The firewall rules
117 # will then be run again on each packet after translation by natd
118 # starting at the rule number following the divert rule.
120 # For ``simple'' firewall type the divert rule should be put to a
121 # different place to not interfere with address-checking rules.
123 case ${firewall_type} in
124 [Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt])
125 case ${natd_enable} in
127 if [ -n "${natd_interface}" ]; then
128 ${fwcmd} add 50 divert natd ip4 from any to any via ${natd_interface}
132 case ${firewall_nat_enable} in
134 if [ -n "${firewall_nat_interface}" ]; then
135 ${fwcmd} nat 123 config if ${firewall_nat_interface} log
136 ${fwcmd} add 50 nat 123 ip4 from any to any via ${firewall_nat_interface}
143 # If you just configured ipfw in the kernel as a tool to solve network
144 # problems or you just want to disallow some particular kinds of traffic
145 # then you will want to change the default policy to open. You can also
146 # do this as your only action by setting the firewall_type to ``open''.
148 # ${fwcmd} add 65000 pass all from any to any
153 case ${firewall_type} in
155 ${fwcmd} add 65000 pass all from any to any
158 [Cc][Ll][Ii][Ee][Nn][Tt])
160 # This is a prototype setup that will protect your system somewhat
161 # against people from outside your own network.
164 # set these to your network and netmask and ip
169 # Allow any traffic to or from my own net.
170 ${fwcmd} add pass all from ${ip} to ${net}:${mask}
171 ${fwcmd} add pass all from ${net}:${mask} to ${ip}
173 # Allow TCP through if setup succeeded
174 ${fwcmd} add pass tcp from any to any established
176 # Allow IP fragments to pass through
177 ${fwcmd} add pass all from any to any frag
179 # Allow setup of incoming email
180 ${fwcmd} add pass tcp from any to me 25 setup
182 # Allow setup of outgoing TCP connections only
183 ${fwcmd} add pass tcp from me to any setup
185 # Disallow setup of all other TCP connections
186 ${fwcmd} add deny tcp from any to any setup
188 # Allow DNS queries out in the world
189 ${fwcmd} add pass udp from me to any 53 keep-state
191 # Allow NTP queries out in the world
192 ${fwcmd} add pass udp from me to any 123 keep-state
194 # Everything else is denied by default, unless the
195 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
199 [Ss][Ii][Mm][Pp][Ll][Ee])
201 # This is a prototype setup for a simple firewall. Configure this
202 # machine as a DNS and NTP server, and point all the machines
203 # on the inside at this machine for those services.
206 # set these to your outside interface network and netmask and ip
209 omask="255.255.255.240"
212 # set these to your inside interface network and netmask and ip
215 imask="255.255.255.240"
219 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif}
220 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif}
222 # Stop RFC1918 nets on the outside interface
223 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif}
224 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif}
225 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif}
227 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
228 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
229 # on the outside interface
230 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif}
231 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif}
232 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif}
233 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif}
234 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif}
236 # Network Address Translation. This rule is placed here deliberately
237 # so that it does not interfere with the surrounding address-checking
238 # rules. If for example one of your internal LAN machines had its IP
239 # address set to 192.0.2.1 then an incoming packet for it after being
240 # translated by natd(8) would match the `deny' rule above. Similarly
241 # an outgoing packet originated from it before being translated would
242 # match the `deny' rule below.
243 case ${natd_enable} in
245 if [ -n "${natd_interface}" ]; then
246 ${fwcmd} add divert natd all from any to any via ${natd_interface}
251 # Stop RFC1918 nets on the outside interface
252 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif}
253 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif}
254 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif}
256 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
257 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
258 # on the outside interface
259 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif}
260 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif}
261 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif}
262 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif}
263 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif}
265 # Allow TCP through if setup succeeded
266 ${fwcmd} add pass tcp from any to any established
268 # Allow IP fragments to pass through
269 ${fwcmd} add pass all from any to any frag
271 # Allow setup of incoming email
272 ${fwcmd} add pass tcp from any to ${oip} 25 setup
274 # Allow access to our DNS
275 ${fwcmd} add pass tcp from any to ${oip} 53 setup
276 ${fwcmd} add pass udp from any to ${oip} 53
277 ${fwcmd} add pass udp from ${oip} 53 to any
279 # Allow access to our WWW
280 ${fwcmd} add pass tcp from any to ${oip} 80 setup
282 # Reject&Log all setup of incoming connections from the outside
283 ${fwcmd} add deny log tcp from any to any in via ${oif} setup
285 # Allow setup of any other TCP connection
286 ${fwcmd} add pass tcp from any to any setup
288 # Allow DNS queries out in the world
289 ${fwcmd} add pass udp from ${oip} to any 53 keep-state
291 # Allow NTP queries out in the world
292 ${fwcmd} add pass udp from ${oip} to any 123 keep-state
294 # Everything else is denied by default, unless the
295 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
299 [Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn])
301 # firewall_myservices: List of TCP ports on which this host
303 # firewall_allowservices: List of IPs which has access to
304 # $firewall_myservices.
305 # firewall_trusted: List of IPs which has full access
306 # to this host. Be very carefull
307 # when setting this. This option can
308 # seriously degrade the level of
309 # protection provided by the firewall.
310 # firewall_logdeny: Boolean (YES/NO) specifying if the
311 # default denied packets should be
312 # logged (in /var/log/security).
313 # firewall_nologports: List of TCP/UDP ports for which
314 # denied incomming packets are not
317 # Allow packets for which a state has been built.
318 ${fwcmd} add check-state
320 # For services permitted below.
321 ${fwcmd} add pass tcp from me to any established
323 # Allow any connection out, adding state for each.
324 ${fwcmd} add pass tcp from me to any setup keep-state
325 ${fwcmd} add pass udp from me to any keep-state
326 ${fwcmd} add pass icmp from me to any keep-state
329 ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
330 ${fwcmd} add pass udp from any 67 to me 68 in
331 ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in
332 # Some servers will ping the IP while trying to decide if it's
334 ${fwcmd} add pass icmp from any to any icmptype 8
336 # Allow "mandatory" ICMP in.
337 ${fwcmd} add pass icmp from any to any icmptype 3,4,11
339 # Add permits for this workstations published services below
340 # Only IPs and nets in firewall_allowservices is allowed in.
341 # If you really wish to let anyone use services on your
342 # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf
344 # Note: We don't use keep-state as that would allow DoS of
346 # You can add 'keep-state' to the lines for slightly
347 # better performance if you fell that DoS of your
348 # workstation won't be a problem.
350 for i in ${firewall_allowservices} ; do
351 for j in ${firewall_myservices} ; do
352 ${fwcmd} add pass tcp from $i to me $j
356 # Allow all connections from trusted IPs.
357 # Playing with the content of firewall_trusted could seriously
358 # degrade the level of protection provided by the firewall.
359 for i in ${firewall_trusted} ; do
360 ${fwcmd} add pass ip from $i to me
363 ${fwcmd} add 65000 count ip from any to any
365 # Drop packets to ports where we don't want logging
366 for i in ${firewall_nologports} ; do
367 ${fwcmd} add deny { tcp or udp } from any to any $i in
370 # Broadcasts and muticasts
371 ${fwcmd} add deny ip from any to 255.255.255.255
372 ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX
375 ${fwcmd} add deny udp from any to any 520 in
377 # Noise from webbrowsing.
378 # The statefull filter is a bit agressive, and will cause some
379 # connection teardowns to be logged.
380 ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in
382 # Deny and (if wanted) log the rest unconditionally.
384 if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then
385 log="log logamount 500" # The default of 100 is too low.
386 sysctl net.inet.ip.fw.verbose=1 >/dev/null
388 ${fwcmd} add deny $log ip from any to any
391 [Cc][Ll][Oo][Ss][Ee][Dd])
392 ${fwcmd} add 65000 deny ip from any to any
394 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
397 if [ -r "${firewall_type}" ]; then
398 ${fwcmd} ${firewall_flags} ${firewall_type}