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 stateful
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
88 if [ $ipv6_available -eq 0 ]; then
89 ${fwcmd} add 400 deny all from any to ::1
90 ${fwcmd} add 500 deny all from ::1 to any
94 setup_ipv6_mandatory() {
95 [ $ipv6_available -eq 0 ] || return 0
98 # Only in rare cases do you want to change these rules
103 ${fwcmd} add pass ipv6-icmp from :: to ff02::/16
104 # RS, RA, NS, NA, redirect...
105 ${fwcmd} add pass ipv6-icmp from fe80::/10 to fe80::/10
106 ${fwcmd} add pass ipv6-icmp from fe80::/10 to ff02::/16
108 # Allow ICMPv6 destination unreachable
109 ${fwcmd} add pass ipv6-icmp from any to any icmp6types 1
111 # Allow NS/NA/toobig (don't filter it out)
112 ${fwcmd} add pass ipv6-icmp from any to any icmp6types 2,135,136
115 if [ -n "${1}" ]; then
125 # Set quiet mode if requested
127 case ${firewall_quiet} in
129 fwcmd="/sbin/ipfw -q"
137 # Flush out the list before we begin.
145 # Network Address Translation. All packets are passed to natd(8)
146 # before they encounter your remaining rules. The firewall rules
147 # will then be run again on each packet after translation by natd
148 # starting at the rule number following the divert rule.
150 # For ``simple'' firewall type the divert rule should be put to a
151 # different place to not interfere with address-checking rules.
153 case ${firewall_type} in
154 [Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt])
155 case ${natd_enable} in
157 if [ -n "${natd_interface}" ]; then
158 ${fwcmd} add 50 divert natd ip4 from any to any via ${natd_interface}
162 case ${firewall_nat_enable} in
164 if [ -n "${firewall_nat_interface}" ]; then
165 if echo "${firewall_nat_interface}" | \
166 grep -q -E '^[0-9]+(\.[0-9]+){0,3}$'; then
167 firewall_nat_flags="ip ${firewall_nat_interface} ${firewall_nat_flags}"
169 firewall_nat_flags="if ${firewall_nat_interface} ${firewall_nat_flags}"
171 ${fwcmd} nat 123 config log ${firewall_nat_flags}
172 ${fwcmd} add 50 nat 123 ip4 from any to any via ${firewall_nat_interface}
179 # If you just configured ipfw in the kernel as a tool to solve network
180 # problems or you just want to disallow some particular kinds of traffic
181 # then you will want to change the default policy to open. You can also
182 # do this as your only action by setting the firewall_type to ``open''.
184 # ${fwcmd} add 65000 pass all from any to any
189 case ${firewall_type} in
191 ${fwcmd} add 65000 pass all from any to any
194 [Cc][Ll][Ii][Ee][Nn][Tt])
196 # This is a prototype setup that will protect your system somewhat
197 # against people from outside your own network.
200 # firewall_client_net: Network address of local IPv4 network.
201 # firewall_client_net_ipv6: Network address of local IPv6 network.
204 # set this to your local network
205 net="$firewall_client_net"
206 net6="$firewall_client_net_ipv6"
208 # Allow limited broadcast traffic from my own net.
209 ${fwcmd} add pass all from ${net} to 255.255.255.255
211 # Allow any traffic to or from my own net.
212 ${fwcmd} add pass all from me to ${net}
213 ${fwcmd} add pass all from ${net} to me
214 if [ -n "$net6" ]; then
215 ${fwcmd} add pass all from me to ${net6}
216 ${fwcmd} add pass all from ${net6} to me
219 if [ -n "$net6" ]; then
220 # Allow any link-local multicast traffic
221 ${fwcmd} add pass all from fe80::/10 to ff02::/16
222 ${fwcmd} add pass all from ${net6} to ff02::/16
224 ${fwcmd} add pass udp from fe80::/10 to me 546
227 # Allow TCP through if setup succeeded
228 ${fwcmd} add pass tcp from any to any established
230 # Allow IP fragments to pass through
231 ${fwcmd} add pass all from any to any frag
233 # Allow setup of incoming email
234 ${fwcmd} add pass tcp from any to me 25 setup
236 # Allow setup of outgoing TCP connections only
237 ${fwcmd} add pass tcp from me to any setup
239 # Disallow setup of all other TCP connections
240 ${fwcmd} add deny tcp from any to any setup
242 # Allow DNS queries out in the world
243 ${fwcmd} add pass udp from me to any 53 keep-state
245 # Allow NTP queries out in the world
246 ${fwcmd} add pass udp from me to any 123 keep-state
248 # Everything else is denied by default, unless the
249 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
253 [Ss][Ii][Mm][Pp][Ll][Ee])
255 # This is a prototype setup for a simple firewall. Configure this
256 # machine as a DNS and NTP server, and point all the machines
257 # on the inside at this machine for those services.
260 # firewall_simple_iif: Inside IPv4 network interface.
261 # firewall_simple_inet: Inside IPv4 network address.
262 # firewall_simple_oif: Outside IPv4 network interface.
263 # firewall_simple_onet: Outside IPv4 network address.
264 # firewall_simple_iif_ipv6: Inside IPv6 network interface.
265 # firewall_simple_inet_ipv6: Inside IPv6 network prefix.
266 # firewall_simple_oif_ipv6: Outside IPv6 network interface.
267 # firewall_simple_onet_ipv6: Outside IPv6 network prefix.
270 # set these to your outside interface network
271 oif="$firewall_simple_oif"
272 onet="$firewall_simple_onet"
273 oif6="${firewall_simple_oif_ipv6:-$firewall_simple_oif}"
274 onet6="$firewall_simple_onet_ipv6"
276 # set these to your inside interface network
277 iif="$firewall_simple_iif"
278 inet="$firewall_simple_inet"
279 iif6="${firewall_simple_iif_ipv6:-$firewall_simple_iif}"
280 inet6="$firewall_simple_inet_ipv6"
283 ${fwcmd} add deny all from ${inet} to any in via ${oif}
284 ${fwcmd} add deny all from ${onet} to any in via ${iif}
285 if [ -n "$inet6" ]; then
286 ${fwcmd} add deny all from ${inet6} to any in via ${oif6}
287 if [ -n "$onet6" ]; then
288 ${fwcmd} add deny all from ${onet6} to any in \
293 # Stop RFC1918 nets on the outside interface
294 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif}
295 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif}
296 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif}
298 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
299 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
300 # on the outside interface
301 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif}
302 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif}
303 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif}
304 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif}
305 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif}
307 # Network Address Translation. This rule is placed here deliberately
308 # so that it does not interfere with the surrounding address-checking
309 # rules. If for example one of your internal LAN machines had its IP
310 # address set to 192.0.2.1 then an incoming packet for it after being
311 # translated by natd(8) would match the `deny' rule above. Similarly
312 # an outgoing packet originated from it before being translated would
313 # match the `deny' rule below.
314 case ${natd_enable} in
316 if [ -n "${natd_interface}" ]; then
317 ${fwcmd} add divert natd ip4 from any to any via ${natd_interface}
322 # Stop RFC1918 nets on the outside interface
323 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif}
324 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif}
325 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif}
327 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
328 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
329 # on the outside interface
330 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif}
331 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif}
332 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif}
333 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif}
334 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif}
336 if [ -n "$inet6" ]; then
337 # Stop unique local unicast address on the outside interface
338 ${fwcmd} add deny all from fc00::/7 to any via ${oif6}
339 ${fwcmd} add deny all from any to fc00::/7 via ${oif6}
341 # Stop site-local on the outside interface
342 ${fwcmd} add deny all from fec0::/10 to any via ${oif6}
343 ${fwcmd} add deny all from any to fec0::/10 via ${oif6}
345 # Disallow "internal" addresses to appear on the wire.
346 ${fwcmd} add deny all from ::ffff:0.0.0.0/96 to any \
348 ${fwcmd} add deny all from any to ::ffff:0.0.0.0/96 \
351 # Disallow packets to malicious IPv4 compatible prefix.
352 ${fwcmd} add deny all from ::224.0.0.0/100 to any via ${oif6}
353 ${fwcmd} add deny all from any to ::224.0.0.0/100 via ${oif6}
354 ${fwcmd} add deny all from ::127.0.0.0/104 to any via ${oif6}
355 ${fwcmd} add deny all from any to ::127.0.0.0/104 via ${oif6}
356 ${fwcmd} add deny all from ::0.0.0.0/104 to any via ${oif6}
357 ${fwcmd} add deny all from any to ::0.0.0.0/104 via ${oif6}
358 ${fwcmd} add deny all from ::255.0.0.0/104 to any via ${oif6}
359 ${fwcmd} add deny all from any to ::255.0.0.0/104 via ${oif6}
361 ${fwcmd} add deny all from ::0.0.0.0/96 to any via ${oif6}
362 ${fwcmd} add deny all from any to ::0.0.0.0/96 via ${oif6}
364 # Disallow packets to malicious 6to4 prefix.
365 ${fwcmd} add deny all from 2002:e000::/20 to any via ${oif6}
366 ${fwcmd} add deny all from any to 2002:e000::/20 via ${oif6}
367 ${fwcmd} add deny all from 2002:7f00::/24 to any via ${oif6}
368 ${fwcmd} add deny all from any to 2002:7f00::/24 via ${oif6}
369 ${fwcmd} add deny all from 2002:0000::/24 to any via ${oif6}
370 ${fwcmd} add deny all from any to 2002:0000::/24 via ${oif6}
371 ${fwcmd} add deny all from 2002:ff00::/24 to any via ${oif6}
372 ${fwcmd} add deny all from any to 2002:ff00::/24 via ${oif6}
374 ${fwcmd} add deny all from 2002:0a00::/24 to any via ${oif6}
375 ${fwcmd} add deny all from any to 2002:0a00::/24 via ${oif6}
376 ${fwcmd} add deny all from 2002:ac10::/28 to any via ${oif6}
377 ${fwcmd} add deny all from any to 2002:ac10::/28 via ${oif6}
378 ${fwcmd} add deny all from 2002:c0a8::/32 to any via ${oif6}
379 ${fwcmd} add deny all from any to 2002:c0a8::/32 via ${oif6}
381 ${fwcmd} add deny all from ff05::/16 to any via ${oif6}
382 ${fwcmd} add deny all from any to ff05::/16 via ${oif6}
385 # Allow TCP through if setup succeeded
386 ${fwcmd} add pass tcp from any to any established
388 # Allow IP fragments to pass through
389 ${fwcmd} add pass all from any to any frag
391 # Allow setup of incoming email
392 ${fwcmd} add pass tcp from any to me 25 setup
394 # Allow access to our DNS
395 ${fwcmd} add pass tcp from any to me 53 setup
396 ${fwcmd} add pass udp from any to me 53
397 ${fwcmd} add pass udp from me 53 to any
399 # Allow access to our WWW
400 ${fwcmd} add pass tcp from any to me 80 setup
402 # Reject&Log all setup of incoming connections from the outside
403 ${fwcmd} add deny log ip4 from any to any in via ${oif} setup proto tcp
404 if [ -n "$inet6" ]; then
405 ${fwcmd} add deny log ip6 from any to any in via ${oif6} \
409 # Allow setup of any other TCP connection
410 ${fwcmd} add pass tcp from any to any setup
412 # Allow DNS queries out in the world
413 ${fwcmd} add pass udp from me to any 53 keep-state
415 # Allow NTP queries out in the world
416 ${fwcmd} add pass udp from me to any 123 keep-state
418 # Everything else is denied by default, unless the
419 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
423 [Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn])
425 # firewall_myservices: List of ports/protocols on which this
426 # host offers services.
427 # firewall_allowservices: List of IPv4 and/or IPv6 addresses
428 # that have access to
429 # $firewall_myservices.
430 # firewall_trusted: List of IPv4 and/or IPv6 addresses
431 # that have full access to this host.
432 # Be very careful when setting this.
433 # This option can seriously degrade
434 # the level of protection provided by
436 # firewall_logdeny: Boolean (YES/NO) specifying if the
437 # default denied packets should be
438 # logged (in /var/log/security).
439 # firewall_nologports: List of TCP/UDP ports for which
440 # denied incoming packets are not
443 # Allow packets for which a state has been built.
444 ${fwcmd} add check-state
446 # For services permitted below.
447 ${fwcmd} add pass tcp from me to any established
449 # Allow any connection out, adding state for each.
450 ${fwcmd} add pass tcp from me to any setup keep-state
451 ${fwcmd} add pass udp from me to any keep-state
452 ${fwcmd} add pass icmp from me to any keep-state
453 if [ $ipv6_available -eq 0 ]; then
454 ${fwcmd} add pass ipv6-icmp from me to any keep-state
458 ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
459 ${fwcmd} add pass udp from any 67 to me 68 in
460 ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in
461 if [ $ipv6_available -eq 0 ]; then
462 ${fwcmd} add pass udp from fe80::/10 to me 546 in
464 # Some servers will ping the IP while trying to decide if it's
466 ${fwcmd} add pass icmp from any to any icmptype 8
467 if [ $ipv6_available -eq 0 ]; then
468 ${fwcmd} add pass ipv6-icmp from any to any icmp6type 128,129
471 # Allow "mandatory" ICMP in.
472 ${fwcmd} add pass icmp from any to any icmptype 3,4,11
473 if [ $ipv6_available -eq 0 ]; then
474 ${fwcmd} add pass ipv6-icmp from any to any icmp6type 3
477 # Add permits for this workstations published services below
478 # Only IPs and nets in firewall_allowservices is allowed in.
479 # If you really wish to let anyone use services on your
480 # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf
482 # Note: We don't use keep-state as that would allow DoS of
484 # You can add 'keep-state' to the lines for slightly
485 # better performance if you fell that DoS of your
486 # workstation won't be a problem.
488 for i in ${firewall_allowservices} ; do
489 for j in ${firewall_myservices} ; do
491 [0-9A-Za-z]*/[Pp][Rr][Oo][Tt][Oo])
492 ${fwcmd} add pass ${j%/[Pp][Rr][Oo][Tt][Oo]} from $i to me
494 [0-9A-Za-z]*/[Tt][Cc][Pp])
495 ${fwcmd} add pass tcp from $i to me ${j%/[Tt][Cc][Pp]}
497 [0-9A-Za-z]*/[Uu][Dd][Pp])
498 ${fwcmd} add pass udp from $i to me ${j%/[Uu][Dd][Pp]}
501 echo "Consider using ${j}/tcp in firewall_myservices." \
503 ${fwcmd} add pass tcp from $i to me $j
506 echo "Invalid port in firewall_myservices: $j" > /dev/stderr
512 # Allow all connections from trusted IPs.
513 # Playing with the content of firewall_trusted could seriously
514 # degrade the level of protection provided by the firewall.
515 for i in ${firewall_trusted} ; do
516 ${fwcmd} add pass ip from $i to me
519 ${fwcmd} add 65000 count ip from any to any
521 # Drop packets to ports where we don't want logging
522 for i in ${firewall_nologports} ; do
523 ${fwcmd} add deny { tcp or udp } from any to any $i in
526 # Broadcasts and multicasts
527 ${fwcmd} add deny ip from any to 255.255.255.255
528 ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX
531 ${fwcmd} add deny udp from any to any 520 in
533 # Noise from webbrowsing.
534 # The stateful filter is a bit aggressive, and will cause some
535 # connection teardowns to be logged.
536 ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in
538 # Deny and (if wanted) log the rest unconditionally.
540 if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then
541 log="log logamount 500" # The default of 100 is too low.
542 sysctl net.inet.ip.fw.verbose=1 >/dev/null
544 ${fwcmd} add deny $log ip from any to any
547 [Cc][Ll][Oo][Ss][Ee][Dd])
548 ${fwcmd} add 65000 deny ip from any to any
550 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
553 if [ -r "${firewall_type}" ]; then
554 ${fwcmd} ${firewall_flags} ${firewall_type}