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1 #!/bin/sh
2 ###############################################################################
3 # #
4 # IPFire.org - A linux based firewall #
5 # Copyright (C) 2007-2022 IPFire Team <info@ipfire.org> #
6 # #
7 # This program is free software: you can redistribute it and/or modify #
8 # it under the terms of the GNU General Public License as published by #
9 # the Free Software Foundation, either version 3 of the License, or #
10 # (at your option) any later version. #
11 # #
12 # This program is distributed in the hope that it will be useful, #
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of #
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
15 # GNU General Public License for more details. #
16 # #
17 # You should have received a copy of the GNU General Public License #
18 # along with this program. If not, see <http://www.gnu.org/licenses/>. #
19 # #
20 ###############################################################################
21
22 . /etc/sysconfig/rc
23 . ${rc_functions}
24
25 eval $(/usr/local/bin/readhash /var/ipfire/ppp/settings)
26 eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
27 eval $(/usr/local/bin/readhash /var/ipfire/optionsfw/settings)
28 IFACE=`/bin/cat /var/ipfire/red/iface 2> /dev/null | /usr/bin/tr -d '\012'`
29 if [ -z $IFACE ]; then
30 IFACE="red0"
31 fi
32
33 if [ -f /var/ipfire/red/device ]; then
34 DEVICE=`/bin/cat /var/ipfire/red/device 2> /dev/null | /usr/bin/tr -d '\012'`
35 fi
36
37 NAT_MASK="0x0f000000"
38
39 IPS_REPEAT_MARK="0x80000000"
40 IPS_REPEAT_MASK="0x80000000"
41 IPS_BYPASS_MARK="0x40000000"
42 IPS_BYPASS_MASK="0x40000000"
43
44 IPSET_DB_DIR="/var/lib/location/ipset"
45
46 function iptables() {
47 /sbin/iptables --wait "$@"
48 }
49
50 iptables_init() {
51 # Flush all rules and delete all custom chains
52 iptables -F
53 iptables -t nat -F
54 iptables -t mangle -F
55 iptables -t raw -F
56 iptables -X
57 iptables -t nat -X
58 iptables -t mangle -X
59 iptables -t raw -X
60
61 # Set up policies
62 iptables -P INPUT DROP
63 iptables -P FORWARD DROP
64 iptables -P OUTPUT ACCEPT
65
66 # Enable TRACE logging to syslog
67 modprobe nf_log_ipv4
68 sysctl -q -w net.netfilter.nf_log.2=nf_log_ipv4
69
70 # IPS Bypass Chain which stores the BYPASS bit in connection tracking
71 iptables -N IPSBYPASS
72 iptables -A IPSBYPASS -j CONNMARK --save-mark --mask "$(( ~IPS_REPEAT_MASK & 0xffffffff ))"
73
74 # Jump into bypass chain when the BYPASS bit is set
75 for chain in INPUT FORWARD OUTPUT; do
76 iptables -A "${chain}" -m mark \
77 --mark "$(( IPS_REPEAT_MARK | IPS_BYPASS_MARK ))/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j IPSBYPASS
78 done
79
80 # Empty LOG_DROP and LOG_REJECT chains
81 iptables -N LOG_DROP
82 iptables -A LOG_DROP -m limit --limit 10/second -j LOG
83 iptables -A LOG_DROP -j DROP
84 iptables -N LOG_REJECT
85 iptables -A LOG_REJECT -m limit --limit 10/second -j LOG
86 iptables -A LOG_REJECT -j REJECT
87
88 # This chain will log, then DROPs packets with certain bad combinations
89 # of flags might indicate a port-scan attempt (xmas, null, etc.)
90 iptables -N PSCAN
91 if [ "$DROPPORTSCAN" == "on" ]; then
92 iptables -A PSCAN -p tcp -m limit --limit 10/second -j LOG --log-prefix "DROP_TCP Scan " -m comment --comment "DROP_TCP PScan"
93 iptables -A PSCAN -p udp -m limit --limit 10/second -j LOG --log-prefix "DROP_UDP Scan " -m comment --comment "DROP_UDP PScan"
94 iptables -A PSCAN -p icmp -m limit --limit 10/second -j LOG --log-prefix "DROP_ICMP Scan " -m comment --comment "DROP_ICMP PScan"
95 iptables -A PSCAN -f -m limit --limit 10/second -j LOG --log-prefix "DROP_FRAG Scan " -m comment --comment "DROP_FRAG PScan"
96 fi
97 iptables -A PSCAN -j DROP -m comment --comment "DROP_PScan"
98
99 # New tcp packets without SYN set - could well be an obscure type of port scan
100 # that's not covered above, may just be a broken Windows machine
101 iptables -N NEWNOTSYN
102 if [ "$DROPNEWNOTSYN" == "on" ]; then
103 iptables -A NEWNOTSYN -m limit --limit 10/second -j LOG --log-prefix "DROP_NEWNOTSYN "
104 fi
105 iptables -A NEWNOTSYN -j DROP -m comment --comment "DROP_NEWNOTSYN"
106
107 # Log and subsequently drop spoofed packets or "martians", arriving from sources
108 # on interfaces where we don't expect them
109 iptables -N SPOOFED_MARTIAN
110 if [ "$DROPSPOOFEDMARTIAN" == "on" ]; then
111 iptables -A SPOOFED_MARTIAN -m limit --limit 10/second -j LOG --log-prefix "DROP_SPOOFED_MARTIAN "
112 fi
113 iptables -A SPOOFED_MARTIAN -j DROP -m comment --comment "DROP_SPOOFED_MARTIAN"
114
115 # Chain to contain all the rules relating to bad TCP flags
116 iptables -N BADTCP
117
118 # Don't check loopback
119 iptables -A BADTCP -i lo -j RETURN
120
121 # Disallow packets frequently used by port-scanners
122 # NMAP FIN/URG/PSH (XMAS scan)
123 iptables -A BADTCP -p tcp --tcp-flags ALL FIN,URG,PSH -j PSCAN
124 # SYN/RST/ACK/FIN/URG
125 iptables -A BADTCP -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j PSCAN
126 # ALL/ALL
127 iptables -A BADTCP -p tcp --tcp-flags ALL ALL -j PSCAN
128 # FIN Stealth
129 iptables -A BADTCP -p tcp --tcp-flags ALL FIN -j PSCAN
130 # SYN/RST (also catches xmas variants that set SYN+RST+...)
131 iptables -A BADTCP -p tcp --tcp-flags SYN,RST SYN,RST -j PSCAN
132 # SYN/FIN (QueSO or nmap OS probe)
133 iptables -A BADTCP -p tcp --tcp-flags SYN,FIN SYN,FIN -j PSCAN
134 # Null
135 iptables -A BADTCP -p tcp --tcp-flags ALL NONE -j PSCAN
136 # NEW TCP without SYN
137 iptables -A BADTCP -p tcp ! --syn -m conntrack --ctstate NEW -j NEWNOTSYN
138
139 iptables -A INPUT -p tcp -j BADTCP
140 iptables -A FORWARD -p tcp -j BADTCP
141
142 # Connection tracking chains
143 iptables -N CTINVALID
144 if [ "$LOGDROPCTINVALID" == "on" ]; then
145 iptables -A CTINVALID -m limit --limit 10/second -j LOG --log-prefix "DROP_CTINVALID "
146 fi
147 iptables -A CTINVALID -j DROP -m comment --comment "DROP_CTINVALID"
148
149 iptables -N CONNTRACK
150 iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
151 iptables -A CONNTRACK -m conntrack --ctstate INVALID -j CTINVALID
152 iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
153
154 # Restore any connection marks
155 iptables -t mangle -A PREROUTING -j CONNMARK --restore-mark
156
157 # Fix for braindead ISPs
158 iptables -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j TCPMSS --clamp-mss-to-pmtu
159
160 # CUSTOM chains, can be used by the users themselves
161 iptables -N CUSTOMINPUT
162 iptables -A INPUT -j CUSTOMINPUT
163 iptables -N CUSTOMFORWARD
164 iptables -A FORWARD -j CUSTOMFORWARD
165 iptables -N CUSTOMOUTPUT
166 iptables -A OUTPUT -j CUSTOMOUTPUT
167 iptables -t nat -N CUSTOMPREROUTING
168 iptables -t nat -A PREROUTING -j CUSTOMPREROUTING
169 iptables -t nat -N CUSTOMPOSTROUTING
170 iptables -t nat -A POSTROUTING -j CUSTOMPOSTROUTING
171
172 # IPS (Guardian) chains
173 iptables -N GUARDIAN
174 iptables -A INPUT -j GUARDIAN
175 iptables -A FORWARD -j GUARDIAN
176
177 # Block non-established IPsec networks
178 iptables -N IPSECBLOCK
179 iptables -A FORWARD -m policy --dir out --pol none -j IPSECBLOCK
180 iptables -A OUTPUT -m policy --dir out --pol none -j IPSECBLOCK
181
182 # Block OpenVPN transfer networks
183 iptables -N OVPNBLOCK
184 iptables -A INPUT -i tun+ -j OVPNBLOCK
185 iptables -A FORWARD -i tun+ -j OVPNBLOCK
186 iptables -A FORWARD -o tun+ -j OVPNBLOCK
187
188 # IPS (Suricata) chains
189 iptables -N IPS_INPUT
190 iptables -N IPS_FORWARD
191 iptables -N IPS_OUTPUT
192
193 for chain in INPUT FORWARD OUTPUT; do
194 iptables -A "${chain}" -m mark --mark "0x0/$(( IPS_REPEAT_MASK | IPS_BYPASS_MASK ))" -j "IPS_${chain}"
195 done
196
197 # OpenVPN transfer network translation
198 iptables -t nat -N OVPNNAT
199 iptables -t nat -A POSTROUTING -j OVPNNAT
200
201 # IPTV chains for IGMPPROXY
202 iptables -N IPTVINPUT
203 iptables -A INPUT -j IPTVINPUT
204 iptables -N IPTVFORWARD
205 iptables -A FORWARD -j IPTVFORWARD
206
207 # Allow to ping the firewall.
208 iptables -N ICMPINPUT
209 iptables -A INPUT -j ICMPINPUT
210 iptables -A ICMPINPUT -p icmp --icmp-type 8 -j ACCEPT
211
212 # Accept everything on loopback
213 iptables -N LOOPBACK
214 iptables -A LOOPBACK -i lo -j ACCEPT
215 iptables -A LOOPBACK -o lo -j ACCEPT
216
217 # Filter all packets with loopback addresses on non-loopback interfaces (spoofed)
218 iptables -A LOOPBACK -s 127.0.0.0/8 -j SPOOFED_MARTIAN
219 iptables -A LOOPBACK -d 127.0.0.0/8 -j SPOOFED_MARTIAN
220
221 for i in INPUT FORWARD OUTPUT; do
222 iptables -A ${i} -j LOOPBACK
223 done
224
225 # Captive portal
226 iptables -N CAPTIVE_PORTAL
227 iptables -N CAPTIVE_PORTAL_CLIENTS
228 for i in INPUT FORWARD; do
229 iptables -A ${i} -j CAPTIVE_PORTAL
230 done
231
232 # Accept everything connected
233 for i in INPUT FORWARD OUTPUT; do
234 iptables -A ${i} -j CONNTRACK
235 done
236
237 # Allow DHCP
238 iptables -N DHCPINPUT
239 iptables -A DHCPINPUT -p udp --sport 68 --dport 67 -j ACCEPT
240 iptables -A DHCPINPUT -p tcp --sport 68 --dport 67 -j ACCEPT
241
242 iptables -N DHCPOUTPUT
243 iptables -A DHCPOUTPUT -p udp --sport 67 --dport 68 -j ACCEPT
244 iptables -A DHCPOUTPUT -p tcp --sport 67 --dport 68 -j ACCEPT
245
246 # Allow DHCP on GREEN
247 iptables -N DHCPGREENINPUT
248 iptables -N DHCPGREENOUTPUT
249 if [ -n "${GREEN_DEV}" ]; then
250 iptables -A INPUT -i "${GREEN_DEV}" -j DHCPGREENINPUT
251 iptables -A OUTPUT -o "${GREEN_DEV}" -j DHCPGREENOUTPUT
252 fi
253
254 # Allow DHCP on BLUE to be turned on/off
255 iptables -N DHCPBLUEINPUT
256 iptables -N DHCPBLUEOUTPUT
257 if [ -n "${BLUE_DEV}" ]; then
258 iptables -A INPUT -i "${BLUE_DEV}" -j DHCPBLUEINPUT
259 iptables -A OUTPUT -o "${BLUE_DEV}" -j DHCPBLUEOUTPUT
260 fi
261
262 # Chains for networks known as being hostile, posing a technical threat to our users
263 # (i. e. listed at Spamhaus DROP et al.)
264 iptables -N HOSTILE
265 iptables -A INPUT -i $IFACE -j HOSTILE
266 iptables -A FORWARD -i $IFACE -j HOSTILE
267 iptables -A FORWARD -o $IFACE -j HOSTILE
268 iptables -A OUTPUT -o $IFACE -j HOSTILE
269
270 # Tor (inbound)
271 iptables -N TOR_INPUT
272 iptables -A INPUT -j TOR_INPUT
273
274 # Location Block
275 iptables -N LOCATIONBLOCK
276 iptables -A INPUT -j LOCATIONBLOCK
277 iptables -A FORWARD -j LOCATIONBLOCK
278
279 # trafic from ipsecX/TUN/TAP interfaces, before "-i GREEN_DEV" accept everything
280 iptables -N IPSECINPUT
281 iptables -N IPSECFORWARD
282 iptables -N IPSECOUTPUT
283 iptables -A INPUT -j IPSECINPUT
284 iptables -A FORWARD -j IPSECFORWARD
285 iptables -A OUTPUT -j IPSECOUTPUT
286 iptables -t nat -N IPSECNAT
287 iptables -t nat -A POSTROUTING -j IPSECNAT
288
289 # localhost and ethernet.
290 # Always allow accessing the web GUI from GREEN.
291 iptables -N GUIINPUT
292 iptables -A INPUT -j GUIINPUT
293 if [ -n "${GREEN_DEV}" ]; then
294 iptables -A GUIINPUT -i "${GREEN_DEV}" -p tcp --dport 444 -j ACCEPT
295 fi
296
297 # WIRELESS chains
298 iptables -N WIRELESSINPUT
299 iptables -A INPUT -m conntrack --ctstate NEW -j WIRELESSINPUT
300 iptables -N WIRELESSFORWARD
301 iptables -A FORWARD -m conntrack --ctstate NEW -j WIRELESSFORWARD
302
303 # OpenVPN
304 iptables -N OVPNINPUT
305 iptables -A INPUT -j OVPNINPUT
306
307 # Tor (outbound)
308 iptables -N TOR_OUTPUT
309 iptables -A OUTPUT -j TOR_OUTPUT
310
311 # Jump into the actual firewall ruleset.
312 iptables -N INPUTFW
313 iptables -A INPUT -j INPUTFW
314
315 iptables -N OUTGOINGFW
316 iptables -A OUTPUT -j OUTGOINGFW
317
318 iptables -N FORWARDFW
319 iptables -A FORWARD -j FORWARDFW
320
321 # SNAT rules
322 iptables -t nat -N NAT_SOURCE
323 iptables -t nat -A POSTROUTING -j NAT_SOURCE
324
325 # Captive Portal
326 iptables -t nat -N CAPTIVE_PORTAL
327 iptables -t nat -A PREROUTING -j CAPTIVE_PORTAL
328
329 # Custom prerouting chains (for transparent proxy)
330 iptables -t nat -N SQUID
331 iptables -t nat -A PREROUTING -j SQUID
332
333 # DNAT rules
334 iptables -t nat -N NAT_DESTINATION
335 iptables -t nat -A PREROUTING -j NAT_DESTINATION
336 iptables -t nat -A OUTPUT -j NAT_DESTINATION
337
338 iptables -t mangle -N NAT_DESTINATION
339 iptables -t mangle -A PREROUTING -j NAT_DESTINATION
340
341 iptables -t nat -N NAT_DESTINATION_FIX
342 iptables -t nat -A POSTROUTING -j NAT_DESTINATION_FIX
343
344 if [ -n "${GREEN_ADDRESS}" ]; then
345 iptables -t nat -A NAT_DESTINATION_FIX \
346 -m mark --mark "0x01000000/${NAT_MASK}" -j SNAT --to-source "${GREEN_ADDRESS}"
347 fi
348
349 if [ -n "${BLUE_ADDRESS}" ]; then
350 iptables -t nat -A NAT_DESTINATION_FIX \
351 -m mark --mark "0x02000000/${NAT_MASK}" -j SNAT --to-source "${BLUE_ADDRESS}"
352 fi
353
354 if [ -n "${ORANGE_ADDRESS}" ]; then
355 iptables -t nat -A NAT_DESTINATION_FIX \
356 -m mark --mark "0x04000000/${NAT_MASK}" -j SNAT --to-source "${ORANGE_ADDRESS}"
357 fi
358
359 # RED chain, used for the red interface
360 iptables -N REDINPUT
361 iptables -A INPUT -j REDINPUT
362 iptables -N REDFORWARD
363 iptables -A FORWARD -j REDFORWARD
364 iptables -t nat -N REDNAT
365 iptables -t nat -A POSTROUTING -j REDNAT
366
367 # Populate IPsec chains
368 /usr/lib/firewall/ipsec-policy
369
370 # Apply OpenVPN firewall rules
371 /usr/local/bin/openvpnctrl --firewall-rules
372
373 # run wirelessctrl
374 /usr/local/bin/wirelessctrl
375
376 # run captivectrl
377 /usr/local/bin/captivectrl
378
379 # POLICY CHAIN
380 iptables -N POLICYIN
381 iptables -A INPUT -j POLICYIN
382 iptables -N POLICYFWD
383 iptables -A FORWARD -j POLICYFWD
384 iptables -N POLICYOUT
385 iptables -A OUTPUT -j POLICYOUT
386
387 # Initialize firewall policies.
388 /usr/sbin/firewall-policy
389
390 # Install firewall rules for the red interface.
391 iptables_red_up
392
393 # If red has not been brought up yet, we will
394 # add the blocking rules for MASQUERADE
395 if [ ! -e "/var/ipfire/red/active" ]; then
396 iptables_red_down
397 fi
398 }
399
400 iptables_red_up() {
401 iptables -F REDINPUT
402 iptables -F REDFORWARD
403 iptables -t nat -F REDNAT
404
405 # Prohibit spoofing our own IP address on RED
406 if [ -f /var/ipfire/red/active ]; then
407 REDIP="$( cat /var/ipfire/red/local-ipaddress )";
408
409 if [ "$IFACE" != "" ]; then
410 iptables -A REDINPUT -s $REDIP -i $IFACE -j SPOOFED_MARTIAN
411 elif [ "$DEVICE" != "" ]; then
412 iptables -A REDINPUT -s $REDIP -i $DEVICE -j SPOOFED_MARTIAN
413 fi
414 fi
415
416 # PPPoE / PPTP Device
417 if [ "$IFACE" != "" ]; then
418 # PPPoE / PPTP
419 if [ "$DEVICE" != "" ]; then
420 iptables -A REDINPUT -i $DEVICE -j ACCEPT
421 fi
422 if [ "$RED_TYPE" == "PPTP" -o "$RED_TYPE" == "PPPOE" ]; then
423 if [ "$RED_DEV" != "" ]; then
424 iptables -A REDINPUT -i $RED_DEV -j ACCEPT
425 fi
426 fi
427 fi
428
429 # PPTP over DHCP
430 if [ "$DEVICE" != "" -a "$TYPE" == "PPTP" -a "$METHOD" == "DHCP" ]; then
431 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
432 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $DEVICE -j ACCEPT
433 fi
434
435 if [ "$IFACE" != "" -a -f /var/ipfire/red/active ]; then
436 # DHCP
437 if [ "$RED_DEV" != "" -a "$RED_TYPE" == "DHCP" ]; then
438 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
439 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
440 fi
441 if [ "$METHOD" == "DHCP" -a "$PROTOCOL" == "RFC1483" ]; then
442 iptables -A REDINPUT -p tcp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
443 iptables -A REDINPUT -p udp --source-port 67 --destination-port 68 -i $IFACE -j ACCEPT
444 fi
445
446 # Outgoing masquerading (don't masqerade IPsec)
447 iptables -t nat -A REDNAT -m policy --pol ipsec --dir=out -o "${IFACE}" -j RETURN
448
449 if [ "${IFACE}" = "${GREEN_DEV}" ]; then
450 iptables -t nat -A REDNAT -i "${GREEN_DEV}" -o "${IFACE}" -j RETURN
451 fi
452
453 local NO_MASQ_NETWORKS
454
455 if [ "${MASQUERADE_GREEN}" = "off" ]; then
456 NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${GREEN_NETADDRESS}/${GREEN_NETMASK}"
457 fi
458
459 if [ "${MASQUERADE_BLUE}" = "off" ]; then
460 NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${BLUE_NETADDRESS}/${BLUE_NETMASK}"
461 fi
462
463 if [ "${MASQUERADE_ORANGE}" = "off" ]; then
464 NO_MASQ_NETWORKS="${NO_MASQ_NETWORKS} ${ORANGE_NETADDRESS}/${ORANGE_NETMASK}"
465 fi
466
467 local network
468 for network in ${NO_MASQ_NETWORKS}; do
469 iptables -t nat -A REDNAT -s "${network}" -o "${IFACE}" -j RETURN
470 done
471
472 # Masquerade everything else
473 iptables -t nat -A REDNAT -o $IFACE -j MASQUERADE
474 fi
475
476 # Reload all rules.
477 /usr/local/bin/firewallctrl
478 }
479
480 iptables_red_down() {
481 # Prohibit packets to reach the masquerading rule
482 # while the WAN interface is down - this is required to
483 # circumvent udp related NAT issues
484 # http://forum.ipfire.org/index.php?topic=11127.0
485 if [ -n "${IFACE}" ]; then
486 iptables -F REDFORWARD
487 iptables -A REDFORWARD -o "${IFACE}" -j DROP
488 fi
489
490 # Reload all rules.
491 /usr/local/bin/firewallctrl
492 }
493
494 # See how we were called.
495 case "$1" in
496 start)
497 boot_mesg "Setting up firewall"
498 iptables_init
499 evaluate_retval
500 ;;
501 reload|up)
502 boot_mesg "Reloading firewall"
503 iptables_red_up
504 evaluate_retval
505 ;;
506 down)
507 boot_mesg "Disabling firewall access to RED"
508 iptables_red_down
509 evaluate_retval
510 ;;
511 restart)
512 $0 start
513 ;;
514 *)
515 echo "Usage: $0 {start|reload|restart}"
516 exit 1
517 ;;
518 esac
519
520 exit 0