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 ${fwcmd} add pass ipv6-icmp from any to any icmp6types 2,135,136
118 if [ -n "${1}" ]; then
121 if [ -z "${firewall_rc_config_load}" ]; then
124 for i in ${firewall_rc_config_load}; do
133 # Set quiet mode if requested
135 case ${firewall_quiet} in
137 fwcmd="/sbin/ipfw -q"
145 # Flush out the list before we begin.
153 # Network Address Translation. All packets are passed to natd(8)
154 # before they encounter your remaining rules. The firewall rules
155 # will then be run again on each packet after translation by natd
156 # starting at the rule number following the divert rule.
158 # For ``simple'' firewall type the divert rule should be put to a
159 # different place to not interfere with address-checking rules.
161 case ${firewall_type} in
162 [Oo][Pp][Ee][Nn]|[Cc][Ll][Ii][Ee][Nn][Tt])
163 case ${natd_enable} in
165 if [ -n "${natd_interface}" ]; then
166 ${fwcmd} add 50 divert natd ip4 from any to any via ${natd_interface}
170 case ${firewall_nat_enable} in
172 if [ -n "${firewall_nat_interface}" ]; then
173 if echo "${firewall_nat_interface}" | \
174 grep -q -E '^[0-9]+(\.[0-9]+){0,3}$'; then
175 firewall_nat_flags="ip ${firewall_nat_interface} ${firewall_nat_flags}"
177 firewall_nat_flags="if ${firewall_nat_interface} ${firewall_nat_flags}"
179 ${fwcmd} nat 123 config log ${firewall_nat_flags}
180 ${fwcmd} add 50 nat 123 ip4 from any to any via ${firewall_nat_interface}
187 # If you just configured ipfw in the kernel as a tool to solve network
188 # problems or you just want to disallow some particular kinds of traffic
189 # then you will want to change the default policy to open. You can also
190 # do this as your only action by setting the firewall_type to ``open''.
192 # ${fwcmd} add 65000 pass all from any to any
197 case ${firewall_type} in
199 ${fwcmd} add 65000 pass all from any to any
202 [Cc][Ll][Ii][Ee][Nn][Tt])
204 # This is a prototype setup that will protect your system somewhat
205 # against people from outside your own network.
208 # firewall_client_net: Network address of local IPv4 network.
209 # firewall_client_net_ipv6: Network address of local IPv6 network.
212 # set this to your local network
213 net="$firewall_client_net"
214 net6="$firewall_client_net_ipv6"
216 # Allow limited broadcast traffic from my own net.
217 ${fwcmd} add pass all from ${net} to 255.255.255.255
219 # Allow any traffic to or from my own net.
220 ${fwcmd} add pass all from me to ${net}
221 ${fwcmd} add pass all from ${net} to me
222 if [ -n "$net6" ]; then
223 ${fwcmd} add pass all from me to ${net6}
224 ${fwcmd} add pass all from ${net6} to me
225 # Allow any link-local multicast traffic
226 ${fwcmd} add pass all from fe80::/10 to ff02::/16
227 ${fwcmd} add pass all from ${net6} to ff02::/16
229 ${fwcmd} add pass udp from fe80::/10 to me 546
232 # Allow TCP through if setup succeeded
233 ${fwcmd} add pass tcp from any to any established
235 # Allow IP fragments to pass through
236 ${fwcmd} add pass all from any to any frag
238 # Allow setup of incoming email
239 ${fwcmd} add pass tcp from any to me 25 setup
241 # Allow setup of outgoing TCP connections only
242 ${fwcmd} add pass tcp from me to any setup
244 # Disallow setup of all other TCP connections
245 ${fwcmd} add deny tcp from any to any setup
247 # Allow DNS queries out in the world
248 ${fwcmd} add pass udp from me to any 53 keep-state
250 # Allow NTP queries out in the world
251 ${fwcmd} add pass udp from me to any 123 keep-state
253 # Everything else is denied by default, unless the
254 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
258 [Ss][Ii][Mm][Pp][Ll][Ee])
260 # This is a prototype setup for a simple firewall. Configure this
261 # machine as a DNS and NTP server, and point all the machines
262 # on the inside at this machine for those services.
265 # firewall_simple_iif: Inside IPv4 network interface.
266 # firewall_simple_inet: Inside IPv4 network address.
267 # firewall_simple_oif: Outside IPv4 network interface.
268 # firewall_simple_onet: Outside IPv4 network address.
269 # firewall_simple_iif_ipv6: Inside IPv6 network interface.
270 # firewall_simple_inet_ipv6: Inside IPv6 network prefix.
271 # firewall_simple_oif_ipv6: Outside IPv6 network interface.
272 # firewall_simple_onet_ipv6: Outside IPv6 network prefix.
276 # set these to your outside interface network
277 oif="$firewall_simple_oif"
278 onet="$firewall_simple_onet"
279 oif6="${firewall_simple_oif_ipv6:-$firewall_simple_oif}"
280 onet6="$firewall_simple_onet_ipv6"
282 # set these to your inside interface network
283 iif="$firewall_simple_iif"
284 inet="$firewall_simple_inet"
285 iif6="${firewall_simple_iif_ipv6:-$firewall_simple_iif}"
286 inet6="$firewall_simple_inet_ipv6"
289 ${fwcmd} add deny all from ${inet} to any in via ${oif}
290 ${fwcmd} add deny all from ${onet} to any in via ${iif}
291 if [ -n "$inet6" ]; then
292 ${fwcmd} add deny all from ${inet6} to any in via ${oif6}
293 if [ -n "$onet6" ]; then
294 ${fwcmd} add deny all from ${onet6} to any in \
299 # Define stuff we should never send out or receive in.
300 # Stop RFC1918 nets on the outside interface
301 ${fwcmd} table ${BAD_ADDR_TBL} flush
302 ${fwcmd} table ${BAD_ADDR_TBL} add 10.0.0.0/8
303 ${fwcmd} table ${BAD_ADDR_TBL} add 172.16.0.0/12
304 ${fwcmd} table ${BAD_ADDR_TBL} add 192.168.0.0/16
306 # And stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
307 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
308 # on the outside interface
309 ${fwcmd} table ${BAD_ADDR_TBL} add 0.0.0.0/8
310 ${fwcmd} table ${BAD_ADDR_TBL} add 169.254.0.0/16
311 ${fwcmd} table ${BAD_ADDR_TBL} add 192.0.2.0/24
312 ${fwcmd} table ${BAD_ADDR_TBL} add 224.0.0.0/4
313 ${fwcmd} table ${BAD_ADDR_TBL} add 240.0.0.0/4
315 ${fwcmd} add deny all from any to "table($BAD_ADDR_TBL)" via ${oif}
317 # Network Address Translation. This rule is placed here deliberately
318 # so that it does not interfere with the surrounding address-checking
319 # rules. If for example one of your internal LAN machines had its IP
320 # address set to 192.0.2.1 then an incoming packet for it after being
321 # translated by natd(8) would match the `deny' rule above. Similarly
322 # an outgoing packet originated from it before being translated would
323 # match the `deny' rule below.
324 case ${natd_enable} in
326 if [ -n "${natd_interface}" ]; then
327 ${fwcmd} add divert natd ip4 from any to any via ${natd_interface}
332 ${fwcmd} add deny all from "table($BAD_ADDR_TBL)" to any via ${oif}
333 if [ -n "$inet6" ]; then
334 # Stop unique local unicast address on the outside interface
335 ${fwcmd} add deny all from fc00::/7 to any via ${oif6}
336 ${fwcmd} add deny all from any to fc00::/7 via ${oif6}
338 # Stop site-local on the outside interface
339 ${fwcmd} add deny all from fec0::/10 to any via ${oif6}
340 ${fwcmd} add deny all from any to fec0::/10 via ${oif6}
342 # Disallow "internal" addresses to appear on the wire.
343 ${fwcmd} add deny all from ::ffff:0.0.0.0/96 to any \
345 ${fwcmd} add deny all from any to ::ffff:0.0.0.0/96 \
348 # Disallow packets to malicious IPv4 compatible prefix.
349 ${fwcmd} add deny all from ::224.0.0.0/100 to any via ${oif6}
350 ${fwcmd} add deny all from any to ::224.0.0.0/100 via ${oif6}
351 ${fwcmd} add deny all from ::127.0.0.0/104 to any via ${oif6}
352 ${fwcmd} add deny all from any to ::127.0.0.0/104 via ${oif6}
353 ${fwcmd} add deny all from ::0.0.0.0/104 to any via ${oif6}
354 ${fwcmd} add deny all from any to ::0.0.0.0/104 via ${oif6}
355 ${fwcmd} add deny all from ::255.0.0.0/104 to any via ${oif6}
356 ${fwcmd} add deny all from any to ::255.0.0.0/104 via ${oif6}
358 ${fwcmd} add deny all from ::0.0.0.0/96 to any via ${oif6}
359 ${fwcmd} add deny all from any to ::0.0.0.0/96 via ${oif6}
361 # Disallow packets to malicious 6to4 prefix.
362 ${fwcmd} add deny all from 2002:e000::/20 to any via ${oif6}
363 ${fwcmd} add deny all from any to 2002:e000::/20 via ${oif6}
364 ${fwcmd} add deny all from 2002:7f00::/24 to any via ${oif6}
365 ${fwcmd} add deny all from any to 2002:7f00::/24 via ${oif6}
366 ${fwcmd} add deny all from 2002:0000::/24 to any via ${oif6}
367 ${fwcmd} add deny all from any to 2002:0000::/24 via ${oif6}
368 ${fwcmd} add deny all from 2002:ff00::/24 to any via ${oif6}
369 ${fwcmd} add deny all from any to 2002:ff00::/24 via ${oif6}
371 ${fwcmd} add deny all from 2002:0a00::/24 to any via ${oif6}
372 ${fwcmd} add deny all from any to 2002:0a00::/24 via ${oif6}
373 ${fwcmd} add deny all from 2002:ac10::/28 to any via ${oif6}
374 ${fwcmd} add deny all from any to 2002:ac10::/28 via ${oif6}
375 ${fwcmd} add deny all from 2002:c0a8::/32 to any via ${oif6}
376 ${fwcmd} add deny all from any to 2002:c0a8::/32 via ${oif6}
378 ${fwcmd} add deny all from ff05::/16 to any via ${oif6}
379 ${fwcmd} add deny all from any to ff05::/16 via ${oif6}
382 # Allow TCP through if setup succeeded
383 ${fwcmd} add pass tcp from any to any established
385 # Allow IP fragments to pass through
386 ${fwcmd} add pass all from any to any frag
388 # Allow setup of incoming email
389 ${fwcmd} add pass tcp from any to me 25 setup
391 # Allow access to our DNS
392 ${fwcmd} add pass tcp from any to me 53 setup
393 ${fwcmd} add pass udp from any to me 53
394 ${fwcmd} add pass udp from me 53 to any
396 # Allow access to our WWW
397 ${fwcmd} add pass tcp from any to me 80 setup
399 # Reject&Log all setup of incoming connections from the outside
400 ${fwcmd} add deny log ip4 from any to any in via ${oif} setup proto tcp
401 if [ -n "$inet6" ]; then
402 ${fwcmd} add deny log ip6 from any to any in via ${oif6} \
406 # Allow setup of any other TCP connection
407 ${fwcmd} add pass tcp from any to any setup
409 # Allow DNS queries out in the world
410 ${fwcmd} add pass udp from me to any 53 keep-state
412 # Allow NTP queries out in the world
413 ${fwcmd} add pass udp from me to any 123 keep-state
415 # Everything else is denied by default, unless the
416 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
420 [Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn])
422 # firewall_myservices: List of ports/protocols on which this
423 # host offers services.
424 # firewall_allowservices: List of IPv4 and/or IPv6 addresses
425 # that have access to
426 # $firewall_myservices.
427 # firewall_trusted: List of IPv4 and/or IPv6 addresses
428 # that have full access to this host.
429 # Be very careful when setting this.
430 # This option can seriously degrade
431 # the level of protection provided by
433 # firewall_logdeny: Boolean (YES/NO) specifying if the
434 # default denied packets should be
435 # logged (in /var/log/security).
436 # firewall_nologports: List of TCP/UDP ports for which
437 # denied incoming packets are not
440 # Allow packets for which a state has been built.
441 ${fwcmd} add check-state
443 # For services permitted below.
444 ${fwcmd} add pass tcp from me to any established
446 # Allow any connection out, adding state for each.
447 ${fwcmd} add pass tcp from me to any setup keep-state
448 ${fwcmd} add pass udp from me to any keep-state
449 ${fwcmd} add pass icmp from me to any keep-state
450 if [ $ipv6_available -eq 0 ]; then
451 ${fwcmd} add pass ipv6-icmp from me to any keep-state
455 ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
456 ${fwcmd} add pass udp from any 67 to me 68 in
457 ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in
458 if [ $ipv6_available -eq 0 ]; then
459 ${fwcmd} add pass udp from fe80::/10 to me 546 in
461 # Some servers will ping the IP while trying to decide if it's
463 ${fwcmd} add pass icmp from any to any icmptype 8
464 if [ $ipv6_available -eq 0 ]; then
465 ${fwcmd} add pass ipv6-icmp from any to any icmp6type 128,129
468 # Allow "mandatory" ICMP in.
469 ${fwcmd} add pass icmp from any to any icmptype 3,4,11
470 if [ $ipv6_available -eq 0 ]; then
471 ${fwcmd} add pass ipv6-icmp from any to any icmp6type 3
474 # Add permits for this workstations published services below
475 # Only IPs and nets in firewall_allowservices is allowed in.
476 # If you really wish to let anyone use services on your
477 # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf
479 # Note: We don't use keep-state as that would allow DoS of
481 # You can add 'keep-state' to the lines for slightly
482 # better performance if you fell that DoS of your
483 # workstation won't be a problem.
485 for i in ${firewall_allowservices} ; do
486 for j in ${firewall_myservices} ; do
488 [0-9A-Za-z]*/[Pp][Rr][Oo][Tt][Oo])
489 ${fwcmd} add pass ${j%/[Pp][Rr][Oo][Tt][Oo]} from $i to me
491 [0-9A-Za-z]*/[Tt][Cc][Pp])
492 ${fwcmd} add pass tcp from $i to me ${j%/[Tt][Cc][Pp]}
494 [0-9A-Za-z]*/[Uu][Dd][Pp])
495 ${fwcmd} add pass udp from $i to me ${j%/[Uu][Dd][Pp]}
498 echo "Consider using ${j}/tcp in firewall_myservices." \
500 ${fwcmd} add pass tcp from $i to me $j
503 echo "Invalid port in firewall_myservices: $j" > /dev/stderr
509 # Allow all connections from trusted IPs.
510 # Playing with the content of firewall_trusted could seriously
511 # degrade the level of protection provided by the firewall.
512 for i in ${firewall_trusted} ; do
513 ${fwcmd} add pass ip from $i to me
516 ${fwcmd} add 65000 count ip from any to any
518 # Drop packets to ports where we don't want logging
519 for i in ${firewall_nologports} ; do
520 ${fwcmd} add deny { tcp or udp } from any to any $i in
523 # Broadcasts and multicasts
524 ${fwcmd} add deny ip from any to 255.255.255.255
525 ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX
528 ${fwcmd} add deny udp from any to any 520 in
530 # Noise from webbrowsing.
531 # The stateful filter is a bit aggressive, and will cause some
532 # connection teardowns to be logged.
533 ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in
535 # Deny and (if wanted) log the rest unconditionally.
537 if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then
538 log="log logamount 500" # The default of 100 is too low.
539 sysctl net.inet.ip.fw.verbose=1 >/dev/null
541 ${fwcmd} add deny $log ip from any to any
544 [Cc][Ll][Oo][Ss][Ee][Dd])
545 ${fwcmd} add 65000 deny ip from any to any
547 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
550 if [ -r "${firewall_type}" ]; then
551 ${fwcmd} ${firewall_flags} ${firewall_type}