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 ${fwcmd} add 65000 pass all from any to any
163 [Cc][Ll][Ii][Ee][Nn][Tt])
165 # This is a prototype setup that will protect your system somewhat
166 # against people from outside your own network.
169 # firewall_client_net: Network address of local network.
172 # set this to your local network
173 net="$firewall_client_net"
175 # Allow any traffic to or from my own net.
176 ${fwcmd} add pass all from me to ${net}
177 ${fwcmd} add pass all from ${net} to me
179 # Allow TCP through if setup succeeded
180 ${fwcmd} add pass tcp from any to any established
182 # Allow IP fragments to pass through
183 ${fwcmd} add pass all from any to any frag
185 # Allow setup of incoming email
186 ${fwcmd} add pass tcp from any to me 25 setup
188 # Allow setup of outgoing TCP connections only
189 ${fwcmd} add pass tcp from me to any setup
191 # Disallow setup of all other TCP connections
192 ${fwcmd} add deny tcp from any to any setup
194 # Allow DNS queries out in the world
195 ${fwcmd} add pass udp from me to any 53 keep-state
197 # Allow NTP queries out in the world
198 ${fwcmd} add pass udp from me to any 123 keep-state
200 # Everything else is denied by default, unless the
201 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
205 [Ss][Ii][Mm][Pp][Ll][Ee])
207 # This is a prototype setup for a simple firewall. Configure this
208 # machine as a DNS and NTP server, and point all the machines
209 # on the inside at this machine for those services.
212 # firewall_simple_iif: Inside network interface.
213 # firewall_simple_inet: Inside network address.
214 # firewall_simple_oif: Outside network interface.
215 # firewall_simple_onet: Outside network address.
218 # set these to your outside interface network
219 oif="$firewall_simple_oif"
220 onet="$firewall_simple_onet"
222 # set these to your inside interface network
223 iif="$firewall_simple_iif"
224 inet="$firewall_simple_inet"
227 ${fwcmd} add deny all from ${inet} to any in via ${oif}
228 ${fwcmd} add deny all from ${onet} to any in via ${iif}
230 # Stop RFC1918 nets on the outside interface
231 ${fwcmd} add deny all from any to 10.0.0.0/8 via ${oif}
232 ${fwcmd} add deny all from any to 172.16.0.0/12 via ${oif}
233 ${fwcmd} add deny all from any to 192.168.0.0/16 via ${oif}
235 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
236 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
237 # on the outside interface
238 ${fwcmd} add deny all from any to 0.0.0.0/8 via ${oif}
239 ${fwcmd} add deny all from any to 169.254.0.0/16 via ${oif}
240 ${fwcmd} add deny all from any to 192.0.2.0/24 via ${oif}
241 ${fwcmd} add deny all from any to 224.0.0.0/4 via ${oif}
242 ${fwcmd} add deny all from any to 240.0.0.0/4 via ${oif}
244 # Network Address Translation. This rule is placed here deliberately
245 # so that it does not interfere with the surrounding address-checking
246 # rules. If for example one of your internal LAN machines had its IP
247 # address set to 192.0.2.1 then an incoming packet for it after being
248 # translated by natd(8) would match the `deny' rule above. Similarly
249 # an outgoing packet originated from it before being translated would
250 # match the `deny' rule below.
251 case ${natd_enable} in
253 if [ -n "${natd_interface}" ]; then
254 ${fwcmd} add divert natd all from any to any via ${natd_interface}
259 # Stop RFC1918 nets on the outside interface
260 ${fwcmd} add deny all from 10.0.0.0/8 to any via ${oif}
261 ${fwcmd} add deny all from 172.16.0.0/12 to any via ${oif}
262 ${fwcmd} add deny all from 192.168.0.0/16 to any via ${oif}
264 # Stop draft-manning-dsua-03.txt (1 May 2000) nets (includes RESERVED-1,
265 # DHCP auto-configuration, NET-TEST, MULTICAST (class D), and class E)
266 # on the outside interface
267 ${fwcmd} add deny all from 0.0.0.0/8 to any via ${oif}
268 ${fwcmd} add deny all from 169.254.0.0/16 to any via ${oif}
269 ${fwcmd} add deny all from 192.0.2.0/24 to any via ${oif}
270 ${fwcmd} add deny all from 224.0.0.0/4 to any via ${oif}
271 ${fwcmd} add deny all from 240.0.0.0/4 to any via ${oif}
273 # Allow TCP through if setup succeeded
274 ${fwcmd} add pass tcp from any to any established
276 # Allow IP fragments to pass through
277 ${fwcmd} add pass all from any to any frag
279 # Allow setup of incoming email
280 ${fwcmd} add pass tcp from any to me 25 setup
282 # Allow access to our DNS
283 ${fwcmd} add pass tcp from any to me 53 setup
284 ${fwcmd} add pass udp from any to me 53
285 ${fwcmd} add pass udp from me 53 to any
287 # Allow access to our WWW
288 ${fwcmd} add pass tcp from any to me 80 setup
290 # Reject&Log all setup of incoming connections from the outside
291 ${fwcmd} add deny log tcp from any to any in via ${oif} setup
293 # Allow setup of any other TCP connection
294 ${fwcmd} add pass tcp from any to any setup
296 # Allow DNS queries out in the world
297 ${fwcmd} add pass udp from me to any 53 keep-state
299 # Allow NTP queries out in the world
300 ${fwcmd} add pass udp from me to any 123 keep-state
302 # Everything else is denied by default, unless the
303 # IPFIREWALL_DEFAULT_TO_ACCEPT option is set in your kernel
307 [Ww][Oo][Rr][Kk][Ss][Tt][Aa][Tt][Ii][Oo][Nn])
309 # firewall_myservices: List of TCP ports on which this host
311 # firewall_allowservices: List of IPs which has access to
312 # $firewall_myservices.
313 # firewall_trusted: List of IPs which has full access
314 # to this host. Be very carefull
315 # when setting this. This option can
316 # seriously degrade the level of
317 # protection provided by the firewall.
318 # firewall_logdeny: Boolean (YES/NO) specifying if the
319 # default denied packets should be
320 # logged (in /var/log/security).
321 # firewall_nologports: List of TCP/UDP ports for which
322 # denied incomming packets are not
325 # Allow packets for which a state has been built.
326 ${fwcmd} add check-state
328 # For services permitted below.
329 ${fwcmd} add pass tcp from me to any established
331 # Allow any connection out, adding state for each.
332 ${fwcmd} add pass tcp from me to any setup keep-state
333 ${fwcmd} add pass udp from me to any keep-state
334 ${fwcmd} add pass icmp from me to any keep-state
337 ${fwcmd} add pass udp from 0.0.0.0 68 to 255.255.255.255 67 out
338 ${fwcmd} add pass udp from any 67 to me 68 in
339 ${fwcmd} add pass udp from any 67 to 255.255.255.255 68 in
340 # Some servers will ping the IP while trying to decide if it's
342 ${fwcmd} add pass icmp from any to any icmptype 8
344 # Allow "mandatory" ICMP in.
345 ${fwcmd} add pass icmp from any to any icmptype 3,4,11
347 # Add permits for this workstations published services below
348 # Only IPs and nets in firewall_allowservices is allowed in.
349 # If you really wish to let anyone use services on your
350 # workstation, then set "firewall_allowservices='any'" in /etc/rc.conf
352 # Note: We don't use keep-state as that would allow DoS of
354 # You can add 'keep-state' to the lines for slightly
355 # better performance if you fell that DoS of your
356 # workstation won't be a problem.
358 for i in ${firewall_allowservices} ; do
359 for j in ${firewall_myservices} ; do
360 ${fwcmd} add pass tcp from $i to me $j
364 # Allow all connections from trusted IPs.
365 # Playing with the content of firewall_trusted could seriously
366 # degrade the level of protection provided by the firewall.
367 for i in ${firewall_trusted} ; do
368 ${fwcmd} add pass ip from $i to me
371 ${fwcmd} add 65000 count ip from any to any
373 # Drop packets to ports where we don't want logging
374 for i in ${firewall_nologports} ; do
375 ${fwcmd} add deny { tcp or udp } from any to any $i in
378 # Broadcasts and muticasts
379 ${fwcmd} add deny ip from any to 255.255.255.255
380 ${fwcmd} add deny ip from any to 224.0.0.0/24 in # XXX
383 ${fwcmd} add deny udp from any to any 520 in
385 # Noise from webbrowsing.
386 # The statefull filter is a bit agressive, and will cause some
387 # connection teardowns to be logged.
388 ${fwcmd} add deny tcp from any 80,443 to any 1024-65535 in
390 # Deny and (if wanted) log the rest unconditionally.
392 if [ ${firewall_logdeny:-x} = "YES" -o ${firewall_logdeny:-x} = "yes" ] ; then
393 log="log logamount 500" # The default of 100 is too low.
394 sysctl net.inet.ip.fw.verbose=1 >/dev/null
396 ${fwcmd} add deny $log ip from any to any
399 [Cc][Ll][Oo][Ss][Ee][Dd])
400 ${fwcmd} add 65000 deny ip from any to any
402 [Uu][Nn][Kk][Nn][Oo][Ww][Nn])
405 if [ -r "${firewall_type}" ]; then
406 ${fwcmd} ${firewall_flags} ${firewall_type}