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 # 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}
135 # If you just configured ipfw in the kernel as a tool to solve network
136 # problems or you just want to disallow some particular kinds of traffic
137 # then you will want to change the default policy to open. You can also
138 # do this as your only action by setting the firewall_type to ``open''.
140 # ${fwcmd} add 65000 pass all from any to any
145 case ${firewall_type} in
147 ${fwcmd} add 65000 pass all from any to any
150 [Cc][Ll][Ii][Ee][Nn][Tt])
152 # This is a prototype setup that will protect your system somewhat
153 # against people from outside your own network.
156 # set these to your network and netmask and ip
161 # Allow any traffic to or from my own net.
162 ${fwcmd} add pass all from ${ip} to ${net}:${mask}
163 ${fwcmd} add pass all from ${net}:${mask} to ${ip}
165 # Allow TCP through if setup succeeded
166 ${fwcmd} add pass tcp from any to any established
168 # Allow IP fragments to pass through
169 ${fwcmd} add pass all from any to any frag
171 # Allow setup of incoming email
172 ${fwcmd} add pass tcp from any to me 25 setup
174 # Allow setup of outgoing TCP connections only
175 ${fwcmd} add pass tcp from me to any setup
177 # Disallow setup of all other TCP connections
178 ${fwcmd} add deny tcp from any to any setup
180 # Allow DNS queries out in the world
181 ${fwcmd} add pass udp from me to any 53 keep-state
183 # Allow NTP queries out in the world
184 ${fwcmd} add pass udp from me to any 123 keep-state
186 # Everything else is denied by default, unless the
187 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
191 [Ss][Ii][Mm][Pp][Ll][Ee])
193 # This is a prototype setup for a simple firewall. Configure this
194 # machine as a DNS and NTP server, and point all the machines
195 # on the inside at this machine for those services.
198 # set these to your outside interface network and netmask and ip
201 omask="255.255.255.240"
204 # set these to your inside interface network and netmask and ip
207 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 [Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn])
293 # firewall_myservices: List of TCP ports on which this host
295 # firewall_allowservices: List of IPs which has access to
296 # $firewall_myservices.
297 # firewall_trusted: List of IPs which has full access
298 # to this host. Be very carefull
299 # when setting this. This option can
300 # seriously degrade the level of
301 # protection provided by the firewall.
302 # firewall_logdeny: Boolean (YES/NO) specifying if the
303 # default denied packets should be
304 # logged (in /var/log/security).
305 # firewall_nologports: List of TCP/UDP ports for which
306 # denied incomming packets are not
309 # Allow packets for which a state has been built.
310 ${fwcmd} add check-state
312 # For services permitted below.
313 ${fwcmd} add pass tcp from me to any established
315 # Allow any connection out, adding state for each.
316 ${fwcmd} add pass tcp from me to any setup keep-state
317 ${fwcmd} add pass udp from me to any keep-state
318 ${fwcmd} add pass icmp from me to any keep-state
321 ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
322 ${fwcmd} add pass udp from any 67 to me 68 in
323 ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in
324 # Some servers will ping the IP while trying to decide if it's
326 ${fwcmd} add pass icmp from any to any icmptype 8
328 # Allow "mandatory" ICMP in.
329 ${fwcmd} add pass icmp from any to any icmptype 3,4,11
331 # Add permits for this workstations published services below
332 # Only IPs and nets in firewall_allowservices is allowed in.
333 # If you really wish to let anyone use services on your
334 # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf
336 # Note: We don't use keep-state as that would allow DoS of
338 # You can add 'keep-state' to the lines for slightly
339 # better performance if you fell that DoS of your
340 # workstation won't be a problem.
342 for i in ${firewall_allowservices} ; do
343 for j in ${firewall_myservices} ; do
344 ${fwcmd} add pass tcp from $i to me $j
348 # Allow all connections from trusted IPs.
349 # Playing with the content of firewall_trusted could seriously
350 # degrade the level of protection provided by the firewall.
351 for i in ${firewall_trusted} ; do
352 ${fwcmd} add pass ip from $i to me
355 ${fwcmd} add 65000 count ip from any to any
357 # Drop packets to ports where we don't want logging
358 for i in ${firewall_nologports} ; do
359 ${fwcmd} add deny { tcp or udp } from any to any $i in
362 # Broadcasts and muticasts
363 ${fwcmd} add deny ip from any to 255.255.255.255
364 ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX
367 ${fwcmd} add deny udp from any to any 520 in
369 # Noise from webbrowsing.
370 # The statefull filter is a bit agressive, and will cause some
371 # connection teardowns to be logged.
372 ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in
374 # Deny and (if wanted) log the rest unconditionally.
376 if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then
377 log="log logamount 500" # The default of 100 is too low.
378 sysctl net.inet.ip.fw.verbose=1 >/dev/null
380 ${fwcmd} add deny $log ip from any to any
383 [Cc][Ll][Oo][Ss][Ee][Dd])
384 ${fwcmd} add 65000 deny ip from any to any
386 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
389 if [ -r "${firewall_type}" ]; then
390 ${fwcmd} ${firewall_flags} ${firewall_type}