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 and Internet Security: Repelling the Wily Hacker, 2nd Edition
73 # William R. Cheswick, Steven M. Bellowin, Aviel D. Rubin
75 # Addison-Wesley / Prentice Hall
77 # http://www.pearsonhighered.com/
78 # http://www.pearsonhighered.com/educator/academic/product/0,3110,020163466X,00.html
83 # Only in rare cases do you want to change these rules
85 ${fwcmd} add 100 pass all from any to any via lo0
86 ${fwcmd} add 200 deny all from any to 127.0.0.0/8
87 ${fwcmd} add 300 deny ip from 127.0.0.0/8 to any
90 if [ -n "${1}" ]; then
95 # Set quiet mode if requested
97 case ${firewall_quiet} in
107 # Flush out the list before we begin.
114 # Network Address Translation. All packets are passed to natd(8)
115 # before they encounter your remaining rules. The firewall rules
116 # will then be run again on each packet after translation by natd
117 # starting at the rule number following the divert rule.
119 # For ``simple'' firewall type the divert rule should be put to a
120 # different place to not interfere with address-checking rules.
122 case ${firewall_type} in
123 [Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt])
124 case ${natd_enable} in
126 if [ -n "${natd_interface}" ]; then
127 ${fwcmd} add 50 divert natd ip4 from any to any via ${natd_interface}
131 case ${firewall_nat_enable} in
133 if [ -n "${firewall_nat_interface}" ]; then
134 if echo "${firewall_nat_interface}" | \
135 grep -q -E '^[0-9]+(\.[0-9]+){0,3}$'; then
136 firewall_nat_flags="ip ${firewall_nat_interface} ${firewall_nat_flags}"
138 firewall_nat_flags="if ${firewall_nat_interface} ${firewall_nat_flags}"
140 ${fwcmd} nat 123 config log ${firewall_nat_flags}
141 ${fwcmd} add 50 nat 123 ip4 from any to any via ${firewall_nat_interface}
148 # If you just configured ipfw in the kernel as a tool to solve network
149 # problems or you just want to disallow some particular kinds of traffic
150 # then you will want to change the default policy to open. You can also
151 # do this as your only action by setting the firewall_type to ``open''.
153 # ${fwcmd} add 65000 pass all from any to any
158 case ${firewall_type} in
160 ${fwcmd} add 65000 pass all from any to any
163 [Cc][Ll][Ii][Ee][Nn][Tt])
165 # This is a prototype setup that will protect your system somewhat
166 # against people from outside your own network.
169 # set these to your network and netmask and ip
174 # Allow any traffic to or from my own net.
175 ${fwcmd} add pass all from ${ip} to ${net}:${mask}
176 ${fwcmd} add pass all from ${net}:${mask} to ${ip}
178 # Allow TCP through if setup succeeded
179 ${fwcmd} add pass tcp from any to any established
181 # Allow IP fragments to pass through
182 ${fwcmd} add pass all from any to any frag
184 # Allow setup of incoming email
185 ${fwcmd} add pass tcp from any to me 25 setup
187 # Allow setup of outgoing TCP connections only
188 ${fwcmd} add pass tcp from me to any setup
190 # Disallow setup of all other TCP connections
191 ${fwcmd} add deny tcp from any to any setup
193 # Allow DNS queries out in the world
194 ${fwcmd} add pass udp from me to any 53 keep-state
196 # Allow NTP queries out in the world
197 ${fwcmd} add pass udp from me to any 123 keep-state
199 # Everything else is denied by default, unless the
200 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
204 [Ss][Ii][Mm][Pp][Ll][Ee])
206 # This is a prototype setup for a simple firewall. Configure this
207 # machine as a DNS and NTP server, and point all the machines
208 # on the inside at this machine for those services.
211 # set these to your outside interface network and netmask and ip
214 omask="255.255.255.240"
217 # set these to your inside interface network and netmask and ip
220 imask="255.255.255.240"
224 ${fwcmd} add deny all from ${inet}:${imask} to any in via ${oif}
225 ${fwcmd} add deny all from ${onet}:${omask} to any in via ${iif}
227 # Stop RFC1918 nets on the outside interface
228 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif}
229 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif}
230 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif}
232 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
233 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
234 # on the outside interface
235 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif}
236 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif}
237 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif}
238 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif}
239 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif}
241 # Network Address Translation. This rule is placed here deliberately
242 # so that it does not interfere with the surrounding address-checking
243 # rules. If for example one of your internal LAN machines had its IP
244 # address set to 192.0.2.1 then an incoming packet for it after being
245 # translated by natd(8) would match the `deny' rule above. Similarly
246 # an outgoing packet originated from it before being translated would
247 # match the `deny' rule below.
248 case ${natd_enable} in
250 if [ -n "${natd_interface}" ]; then
251 ${fwcmd} add divert natd all from any to any via ${natd_interface}
256 # Stop RFC1918 nets on the outside interface
257 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif}
258 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif}
259 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif}
261 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
262 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
263 # on the outside interface
264 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif}
265 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif}
266 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif}
267 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif}
268 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif}
270 # Allow TCP through if setup succeeded
271 ${fwcmd} add pass tcp from any to any established
273 # Allow IP fragments to pass through
274 ${fwcmd} add pass all from any to any frag
276 # Allow setup of incoming email
277 ${fwcmd} add pass tcp from any to ${oip} 25 setup
279 # Allow access to our DNS
280 ${fwcmd} add pass tcp from any to ${oip} 53 setup
281 ${fwcmd} add pass udp from any to ${oip} 53
282 ${fwcmd} add pass udp from ${oip} 53 to any
284 # Allow access to our WWW
285 ${fwcmd} add pass tcp from any to ${oip} 80 setup
287 # Reject&Log all setup of incoming connections from the outside
288 ${fwcmd} add deny log tcp from any to any in via ${oif} setup
290 # Allow setup of any other TCP connection
291 ${fwcmd} add pass tcp from any to any setup
293 # Allow DNS queries out in the world
294 ${fwcmd} add pass udp from ${oip} to any 53 keep-state
296 # Allow NTP queries out in the world
297 ${fwcmd} add pass udp from ${oip} to any 123 keep-state
299 # Everything else is denied by default, unless the
300 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
304 [Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn])
306 # firewall_myservices: List of TCP ports on which this host
308 # firewall_allowservices: List of IPs which has access to
309 # $firewall_myservices.
310 # firewall_trusted: List of IPs which has full access
311 # to this host. Be very carefull
312 # when setting this. This option can
313 # seriously degrade the level of
314 # protection provided by the firewall.
315 # firewall_logdeny: Boolean (YES/NO) specifying if the
316 # default denied packets should be
317 # logged (in /var/log/security).
318 # firewall_nologports: List of TCP/UDP ports for which
319 # denied incomming packets are not
322 # Allow packets for which a state has been built.
323 ${fwcmd} add check-state
325 # For services permitted below.
326 ${fwcmd} add pass tcp from me to any established
328 # Allow any connection out, adding state for each.
329 ${fwcmd} add pass tcp from me to any setup keep-state
330 ${fwcmd} add pass udp from me to any keep-state
331 ${fwcmd} add pass icmp from me to any keep-state
334 ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
335 ${fwcmd} add pass udp from any 67 to me 68 in
336 ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in
337 # Some servers will ping the IP while trying to decide if it's
339 ${fwcmd} add pass icmp from any to any icmptype 8
341 # Allow "mandatory" ICMP in.
342 ${fwcmd} add pass icmp from any to any icmptype 3,4,11
344 # Add permits for this workstations published services below
345 # Only IPs and nets in firewall_allowservices is allowed in.
346 # If you really wish to let anyone use services on your
347 # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf
349 # Note: We don't use keep-state as that would allow DoS of
351 # You can add 'keep-state' to the lines for slightly
352 # better performance if you fell that DoS of your
353 # workstation won't be a problem.
355 for i in ${firewall_allowservices} ; do
356 for j in ${firewall_myservices} ; do
357 ${fwcmd} add pass tcp from $i to me $j
361 # Allow all connections from trusted IPs.
362 # Playing with the content of firewall_trusted could seriously
363 # degrade the level of protection provided by the firewall.
364 for i in ${firewall_trusted} ; do
365 ${fwcmd} add pass ip from $i to me
368 ${fwcmd} add 65000 count ip from any to any
370 # Drop packets to ports where we don't want logging
371 for i in ${firewall_nologports} ; do
372 ${fwcmd} add deny { tcp or udp } from any to any $i in
375 # Broadcasts and muticasts
376 ${fwcmd} add deny ip from any to 255.255.255.255
377 ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX
380 ${fwcmd} add deny udp from any to any 520 in
382 # Noise from webbrowsing.
383 # The statefull filter is a bit agressive, and will cause some
384 # connection teardowns to be logged.
385 ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in
387 # Deny and (if wanted) log the rest unconditionally.
389 if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then
390 log="log logamount 500" # The default of 100 is too low.
391 sysctl net.inet.ip.fw.verbose=1 >/dev/null
393 ${fwcmd} add deny $log ip from any to any
396 [Cc][Ll][Oo][Ss][Ee][Dd])
397 ${fwcmd} add 65000 deny ip from any to any
399 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
402 if [ -r "${firewall_type}" ]; then
403 ${fwcmd} ${firewall_flags} ${firewall_type}