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Firewall: make DNAT only accessible from selected source network
[ipfire-2.x.git] / config / firewall / rules.pl
1 #!/usr/bin/perl -w
2 ###############################################################################
3 # #
4 # IPFire.org - A linux based firewall #
5 # Copyright (C) 2013 Alexander Marx <amarx@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 use strict;
23
24 require '/var/ipfire/general-functions.pl';
25 require "${General::swroot}/lang.pl";
26 require "/usr/lib/firewall/firewall-lib.pl";
27
28 # Set to one to enable debugging mode.
29 my $DEBUG = 0;
30
31 my $IPTABLES = "iptables --wait";
32
33 # iptables chains
34 my $CHAIN_INPUT = "INPUTFW";
35 my $CHAIN_FORWARD = "FORWARDFW";
36 my $CHAIN_OUTPUT = "OUTGOINGFW";
37 my $CHAIN = $CHAIN_FORWARD;
38 my $CHAIN_NAT_SOURCE = "NAT_SOURCE";
39 my $CHAIN_NAT_DESTINATION = "NAT_DESTINATION";
40 my $CHAIN_MANGLE_NAT_DESTINATION_FIX = "NAT_DESTINATION";
41 my @VALID_CHAINS = ($CHAIN_INPUT, $CHAIN_FORWARD, $CHAIN_OUTPUT);
42 my @ANY_ADDRESSES = ("0.0.0.0/0.0.0.0", "0.0.0.0/0", "0/0");
43
44 my @PROTOCOLS = ("tcp", "udp", "icmp", "igmp", "ah", "esp", "gre", "ipv6", "ipip");
45 my @PROTOCOLS_WITH_PORTS = ("tcp", "udp");
46
47 my @VALID_TARGETS = ("ACCEPT", "DROP", "REJECT");
48
49 my %fwdfwsettings=();
50 my %fwoptions = ();
51 my %defaultNetworks=();
52 my %configfwdfw=();;
53 my %customgrp=();
54 my %configinputfw=();
55 my %configoutgoingfw=();
56 my %confignatfw=();
57 my @p2ps=();
58
59 my $configfwdfw = "${General::swroot}/firewall/config";
60 my $configinput = "${General::swroot}/firewall/input";
61 my $configoutgoing = "${General::swroot}/firewall/outgoing";
62 my $p2pfile = "${General::swroot}/firewall/p2protocols";
63 my $configgrp = "${General::swroot}/fwhosts/customgroups";
64 my $netsettings = "${General::swroot}/ethernet/settings";
65
66 &General::readhash("${General::swroot}/firewall/settings", \%fwdfwsettings);
67 &General::readhash("${General::swroot}/optionsfw/settings", \%fwoptions);
68 &General::readhash("$netsettings", \%defaultNetworks);
69 &General::readhasharray($configfwdfw, \%configfwdfw);
70 &General::readhasharray($configinput, \%configinputfw);
71 &General::readhasharray($configoutgoing, \%configoutgoingfw);
72 &General::readhasharray($configgrp, \%customgrp);
73
74 my @log_limit_options = &make_log_limit_options();
75
76 my $POLICY_INPUT_ALLOWED = 0;
77 my $POLICY_FORWARD_ALLOWED = ($fwdfwsettings{"POLICY"} eq "MODE2");
78 my $POLICY_OUTPUT_ALLOWED = ($fwdfwsettings{"POLICY1"} eq "MODE2");
79
80 my $POLICY_INPUT_ACTION = $fwoptions{"FWPOLICY2"};
81 my $POLICY_FORWARD_ACTION = $fwoptions{"FWPOLICY"};
82 my $POLICY_OUTPUT_ACTION = $fwoptions{"FWPOLICY1"};
83
84 # MAIN
85 &main();
86
87 sub main {
88 # Flush all chains.
89 &flush();
90
91 # Reload firewall rules.
92 &preparerules();
93
94 # Load P2P block rules.
95 &p2pblock();
96
97 # Reload firewall policy.
98 run("/usr/sbin/firewall-policy");
99 }
100
101 sub run {
102 # Executes or prints the given shell command.
103 my $command = shift;
104
105 if ($DEBUG) {
106 print "$command\n";
107 } else {
108 system "$command";
109
110 if ($?) {
111 print_error("ERROR: $command");
112 }
113 }
114 }
115
116 sub print_error {
117 my $message = shift;
118
119 print STDERR "$message\n";
120 }
121
122 sub print_rule {
123 my $hash = shift;
124
125 print "\nRULE:";
126
127 my $i = 0;
128 foreach (@$hash) {
129 printf(" %2d: %s", $i++, $_);
130 }
131 print "\n";
132 }
133
134 sub flush {
135 run("$IPTABLES -F $CHAIN_INPUT");
136 run("$IPTABLES -F $CHAIN_FORWARD");
137 run("$IPTABLES -F $CHAIN_OUTPUT");
138 run("$IPTABLES -t nat -F $CHAIN_NAT_SOURCE");
139 run("$IPTABLES -t nat -F $CHAIN_NAT_DESTINATION");
140 run("$IPTABLES -t mangle -F $CHAIN_MANGLE_NAT_DESTINATION_FIX");
141 }
142
143 sub preparerules {
144 if (! -z "${General::swroot}/firewall/input"){
145 &buildrules(\%configinputfw);
146 }
147 if (! -z "${General::swroot}/firewall/outgoing"){
148 &buildrules(\%configoutgoingfw);
149 }
150 if (! -z "${General::swroot}/firewall/config"){
151 &buildrules(\%configfwdfw);
152 }
153 }
154
155 sub buildrules {
156 my $hash = shift;
157
158 # Search for targets that need to be specially handled when adding
159 # forwarding rules. Additional rules will automatically get inserted
160 # into the INPUT/OUTPUT chains for these targets.
161 my @special_input_targets = ();
162 if (!$POLICY_FORWARD_ALLOWED) {
163 push(@special_input_targets, "ACCEPT");
164 }
165
166 if ($POLICY_INPUT_ACTION eq "DROP") {
167 push(@special_input_targets, "REJECT");
168 } elsif ($POLICY_INPUT_ACTION eq "REJECT") {
169 push(@special_input_targets, "DROP");
170 }
171
172 my @special_output_targets = ();
173 if ($POLICY_OUTPUT_ALLOWED) {
174 push(@special_output_targets, ("DROP", "REJECT"));
175 } else {
176 push(@special_output_targets, "ACCEPT");
177
178 if ($POLICY_OUTPUT_ACTION eq "DROP") {
179 push(@special_output_targets, "REJECT");
180 } elsif ($POLICY_OUTPUT_ACTION eq "REJECT") {
181 push(@special_output_targets, "DROP");
182 }
183 }
184
185 foreach my $key (sort {$a <=> $b} keys %$hash) {
186 # Skip disabled rules.
187 next unless ($$hash{$key}[2] eq 'ON');
188
189 if ($DEBUG) {
190 print_rule($$hash{$key});
191 }
192
193 # Check if the target is valid.
194 my $target = $$hash{$key}[0];
195 if (!$target ~~ @VALID_TARGETS) {
196 print_error("Invalid target '$target' for rule $key");
197 next;
198 }
199
200 # Check if the chain is valid.
201 my $chain = $$hash{$key}[1];
202 if (!$chain ~~ @VALID_CHAINS) {
203 print_error("Invalid chain '$chain' in rule $key");
204 next;
205 }
206
207 # Collect all sources.
208 my @sources = &fwlib::get_addresses($hash, $key, "src");
209
210 # Collect all destinations.
211 my @destinations = &fwlib::get_addresses($hash, $key, "tgt");
212
213 # True if the destination is the firewall itself.
214 my $destination_is_firewall = ($$hash{$key}[5] eq "ipfire");
215
216 # Check if logging should be enabled.
217 my $LOG = ($$hash{$key}[17] eq 'ON');
218
219 # Check if NAT is enabled and initialize variables, that we use for that.
220 my $NAT = ($$hash{$key}[28] eq 'ON');
221 my $NAT_MODE;
222 if ($NAT) {
223 $NAT_MODE = uc($$hash{$key}[31]);
224 }
225
226 # Set up time constraints.
227 my @time_options = ();
228 if ($$hash{$key}[18] eq 'ON') {
229 push(@time_options, ("-m", "time"));
230
231 # Select all days of the week this match is active.
232 my @weekdays = ();
233 if ($$hash{$key}[19] ne '') {
234 push (@weekdays, "Mon");
235 }
236 if ($$hash{$key}[20] ne '') {
237 push (@weekdays, "Tue");
238 }
239 if ($$hash{$key}[21] ne '') {
240 push (@weekdays, "Wed");
241 }
242 if ($$hash{$key}[22] ne '') {
243 push (@weekdays, "Thu");
244 }
245 if ($$hash{$key}[23] ne '') {
246 push (@weekdays, "Fri");
247 }
248 if ($$hash{$key}[24] ne '') {
249 push (@weekdays, "Sat");
250 }
251 if ($$hash{$key}[25] ne '') {
252 push (@weekdays, "Sun");
253 }
254 if (@weekdays) {
255 push(@time_options, ("--weekdays", join(",", @weekdays)));
256 }
257
258 # Convert start time.
259 my $time_start = &format_time($$hash{$key}[26]);
260 if ($time_start) {
261 push(@time_options, ("--timestart", $time_start));
262 }
263
264 # Convert end time.
265 my $time_stop = &format_time($$hash{$key}[27]);
266 if ($time_stop) {
267 push(@time_options, ("--timestop", $time_stop));
268 }
269 }
270
271 # Check which protocols are used in this rule and so that we can
272 # later group rules by protocols.
273 my @protocols = &get_protocols($hash, $key);
274 if (!@protocols) {
275 print_error("Invalid protocol configuration for rule $key");
276 next;
277 }
278
279 foreach my $protocol (@protocols) {
280 # Check if the given protocol is supported.
281 if (($protocol ne "all") && (!$protocol ~~ @PROTOCOLS)) {
282 print_error("Protocol $protocol is not supported (rule $key)");
283 next;
284 }
285
286 # Prepare protocol options (like ICMP types, ports, etc...).
287 my @protocol_options = &get_protocol_options($hash, $key, $protocol, 0);
288
289 # Check if this protocol knows ports.
290 my $protocol_has_ports = ($protocol ~~ @PROTOCOLS_WITH_PORTS);
291
292 foreach my $src (@sources) {
293 # Skip invalid source.
294 next unless (@$src[0]);
295
296 # Sanitize source.
297 my $source = @$src[0];
298 if ($source ~~ @ANY_ADDRESSES) {
299 $source = "";
300 }
301
302 my $source_intf = @$src[1];
303
304 foreach my $dst (@destinations) {
305 # Skip invalid rules.
306 next if (!@$dst[0] || (@$dst[0] eq "none"));
307
308 # Sanitize destination.
309 my $destination = @$dst[0];
310 if ($destination ~~ @ANY_ADDRESSES) {
311 $destination = "";
312 }
313
314 my $destination_intf = @$dst[1];
315
316 # Array with iptables arguments.
317 my @options = ();
318
319 # Append protocol.
320 if ($protocol ne "all") {
321 push(@options, @protocol_options);
322 }
323
324 # Prepare source options.
325 my @source_options = ();
326 if ($source =~ /mac/) {
327 push(@source_options, $source);
328 } elsif ($source) {
329 push(@source_options, ("-s", $source));
330 }
331
332 if ($source_intf) {
333 push(@source_options, ("-i", $source_intf));
334 }
335
336 # Prepare destination options.
337 my @destination_options = ();
338 if ($destination) {
339 push(@destination_options, ("-d", $destination));
340 }
341
342 if ($destination_intf) {
343 push(@destination_options, ("-o", $destination_intf));
344 }
345
346 # Add time constraint options.
347 push(@options, @time_options);
348
349 my $firewall_is_in_source_subnet = 1;
350 if ($source) {
351 $firewall_is_in_source_subnet = &firewall_is_in_subnet($source);
352 }
353
354 my $firewall_is_in_destination_subnet = 1;
355 if ($destination) {
356 $firewall_is_in_destination_subnet = &firewall_is_in_subnet($destination);
357 }
358
359 # Process NAT rules.
360 if ($NAT) {
361 my $nat_address = &fwlib::get_nat_address($$hash{$key}[29], $source);
362
363 # Skip NAT rules if the NAT address is unknown
364 # (i.e. no internet connection has been established, yet).
365 next unless ($nat_address);
366
367 # Destination NAT
368 if ($NAT_MODE eq "DNAT") {
369 my @nat_options = ();
370 if ($protocol ne "all") {
371 my @nat_protocol_options = &get_protocol_options($hash, $key, $protocol, 1);
372 push(@nat_options, @nat_protocol_options);
373 }
374 push(@nat_options, @time_options);
375
376 # Make port-forwardings useable from the internal networks.
377 my @internal_addresses = &fwlib::get_internal_firewall_ip_addresses(1);
378 unless ($nat_address ~~ @internal_addresses) {
379 &add_dnat_mangle_rules($nat_address, $source_intf, @nat_options);
380 }
381
382 push(@nat_options, @source_options);
383 push(@nat_options, ("-d", $nat_address));
384
385 my $dnat_port;
386 if ($protocol_has_ports) {
387 $dnat_port = &get_dnat_target_port($hash, $key);
388 }
389
390 my @nat_action_options = ();
391
392 # Use iptables REDIRECT
393 my $use_redirect = ($destination_is_firewall && !$destination && $protocol_has_ports && $dnat_port);
394 if ($use_redirect) {
395 push(@nat_action_options, ("-j", "REDIRECT", "--to-ports", $dnat_port));
396
397 # Use iptables DNAT
398 } else {
399 if ($destination_is_firewall && !$destination) {
400 $destination = &fwlib::get_external_address();
401 }
402 next unless ($destination);
403
404 my ($dnat_address, $dnat_mask) = split("/", $destination);
405 @destination_options = ("-d", $dnat_address);
406
407 if ($protocol_has_ports) {
408 my $dnat_port = &get_dnat_target_port($hash, $key);
409
410 if ($dnat_port) {
411 $dnat_address .= ":$dnat_port";
412 }
413 }
414
415 push(@nat_action_options, ("-j", "DNAT", "--to-destination", $dnat_address));
416 }
417
418 if ($LOG) {
419 run("$IPTABLES -t nat -A $CHAIN_NAT_DESTINATION @nat_options @log_limit_options -j LOG --log-prefix 'DNAT '");
420 }
421 run("$IPTABLES -t nat -A $CHAIN_NAT_DESTINATION @nat_options @nat_action_options");
422
423 # Source NAT
424 } elsif ($NAT_MODE eq "SNAT") {
425 my @nat_options = @options;
426
427 push(@nat_options, @source_options);
428 push(@nat_options, @destination_options);
429
430 if ($LOG) {
431 run("$IPTABLES -t nat -A $CHAIN_NAT_SOURCE @nat_options @log_limit_options -j LOG --log-prefix 'SNAT '");
432 }
433 run("$IPTABLES -t nat -A $CHAIN_NAT_SOURCE @nat_options -j SNAT --to-source $nat_address");
434 }
435 }
436
437 push(@options, @source_options);
438 push(@options, @destination_options);
439
440 # Insert firewall rule.
441 if ($LOG && !$NAT) {
442 run("$IPTABLES -A $chain @options @log_limit_options -j LOG --log-prefix '$chain '");
443 }
444 run("$IPTABLES -A $chain @options -j $target");
445
446 # Handle forwarding rules and add corresponding rules for firewall access.
447 if ($chain eq $CHAIN_FORWARD) {
448 # If the firewall is part of the destination subnet and access to the destination network
449 # is granted/forbidden for any network that the firewall itself is part of, we grant/forbid access
450 # for the firewall, too.
451 if ($firewall_is_in_destination_subnet && ($target ~~ @special_input_targets)) {
452 if ($LOG && !$NAT) {
453 run("$IPTABLES -A $CHAIN_INPUT @options @log_limit_options -j LOG --log-prefix '$CHAIN_INPUT '");
454 }
455 run("$IPTABLES -A $CHAIN_INPUT @options -j $target");
456 }
457
458 # Likewise.
459 if ($firewall_is_in_source_subnet && ($target ~~ @special_output_targets)) {
460 if ($LOG && !$NAT) {
461 run("$IPTABLES -A $CHAIN_OUTPUT @options @log_limit_options -j LOG --log-prefix '$CHAIN_OUTPUT '");
462 }
463 run("$IPTABLES -A $CHAIN_OUTPUT @options -j $target");
464 }
465 }
466 }
467 }
468 }
469 }
470 }
471
472 # Formats the given timestamp into the iptables format which is "hh:mm" UTC.
473 sub format_time {
474 my $val = shift;
475
476 # Convert the given time into minutes.
477 my $minutes = &time_convert_to_minutes($val);
478
479 # Move the timestamp into UTC.
480 $minutes += &time_utc_offset();
481
482 # Make sure $minutes is between 00:00 and 23:59.
483 if ($minutes < 0) {
484 $minutes += 1440;
485 }
486
487 if ($minutes > 1440) {
488 $minutes -= 1440;
489 }
490
491 # Format as hh:mm.
492 return sprintf("%02d:%02d", $minutes / 60, $minutes % 60);
493 }
494
495 # Calculates the offsets in minutes from the local timezone to UTC.
496 sub time_utc_offset {
497 my @localtime = localtime(time);
498 my @gmtime = gmtime(time);
499
500 return ($gmtime[2] * 60 + $gmtime[1] % 60) - ($localtime[2] * 60 + $localtime[1] % 60);
501 }
502
503 # Takes a timestamp like "14:00" and converts it into minutes since midnight.
504 sub time_convert_to_minutes {
505 my ($hrs, $min) = split(":", shift);
506
507 return ($hrs * 60) + $min;
508 }
509
510 sub p2pblock {
511 my $search_action;
512 my $target;
513
514 if ($fwdfwsettings{"POLICY"} eq "MODE1") {
515 $search_action = "on";
516 $target = "ACCEPT";
517 } else {
518 $search_action = "off";
519 $target = "DROP";
520 }
521
522 open(FILE, "<$p2pfile") or die "Unable to read $p2pfile";
523 my @protocols = ();
524 foreach my $p2pentry (<FILE>) {
525 my @p2pline = split(/\;/, $p2pentry);
526 next unless ($p2pline[2] eq $search_action);
527
528 push(@protocols, "--$p2pline[1]");
529 }
530 close(FILE);
531
532 if (@protocols) {
533 run("$IPTABLES -A FORWARDFW -m ipp2p @protocols -j $target");
534 }
535 }
536
537 sub get_protocols {
538 my $hash = shift;
539 my $key = shift;
540
541 my $uses_source_ports = ($$hash{$key}[7] eq "ON");
542 my $uses_services = ($$hash{$key}[11] eq "ON");
543
544 my @protocols = ();
545
546 # Rules which don't have source ports or services (like ICMP, ESP, ...).
547 if (!$uses_source_ports && !$uses_services) {
548 push(@protocols, $$hash{$key}[8]);
549
550 # Rules which either use ports or services.
551 } elsif ($uses_source_ports || $uses_services) {
552 # Check if service group or service
553 if ($$hash{$key}[14] eq 'cust_srv') {
554 push(@protocols, &fwlib::get_srv_prot($$hash{$key}[15]));
555
556 } elsif($$hash{$key}[14] eq 'cust_srvgrp'){
557 my $protos = &fwlib::get_srvgrp_prot($$hash{$key}[15]);
558 push(@protocols, split(",", $protos));
559
560 } else {
561 # Fetch the protocol for this rule.
562 my $protocol = lc($$hash{$key}[8]);
563
564 # Fetch source and destination ports for this rule.
565 my $source_ports = $$hash{$key}[10];
566 my $destination_ports = $$hash{$key}[15];
567
568 # Check if ports are set for protocols which do not support ports.
569 if (!($protocol ~~ @PROTOCOLS_WITH_PORTS) && ($source_ports || $destination_ports)) {
570 print_error("$protocol does not support ports");
571 return ();
572 }
573
574 push(@protocols, $protocol);
575 }
576 }
577
578 # Remove all empty elements
579 @protocols = map { $_ ? $_ : () } @protocols;
580
581 # If no protocol has been defined, we assume "all".
582 if (!@protocols) {
583 push(@protocols, "all");
584 }
585
586 # Make all protocol names lowercase.
587 @protocols = map { lc } @protocols;
588
589 return @protocols;
590 }
591
592 sub get_protocol_options {
593 my $hash = shift;
594 my $key = shift;
595 my $protocol = shift;
596 my $nat_options_wanted = shift;
597 my @options = ();
598
599 # Nothing to do if no protocol is specified.
600 if ($protocol eq "all") {
601 return @options;
602 } else {
603 push(@options, ("-p", $protocol));
604 }
605
606 if ($protocol ~~ @PROTOCOLS_WITH_PORTS) {
607 # Process source ports.
608 my $use_src_ports = ($$hash{$key}[7] eq "ON");
609 my $src_ports = $$hash{$key}[10];
610
611 if ($use_src_ports && $src_ports) {
612 push(@options, &format_ports($src_ports, "src"));
613 }
614
615 # Process destination ports.
616 my $use_dst_ports = ($$hash{$key}[11] eq "ON");
617 my $use_dnat = (($$hash{$key}[28] eq "ON") && ($$hash{$key}[31] eq "dnat"));
618
619 if ($use_dst_ports) {
620 my $dst_ports_mode = $$hash{$key}[14];
621 my $dst_ports = $$hash{$key}[15];
622
623 if (($dst_ports_mode eq "TGT_PORT") && $dst_ports) {
624 if ($nat_options_wanted && $use_dnat && $$hash{$key}[30]) {
625 $dst_ports = $$hash{$key}[30];
626 }
627 push(@options, &format_ports($dst_ports, "dst"));
628
629 } elsif ($dst_ports_mode eq "cust_srv") {
630 if ($protocol eq "ICMP") {
631 push(@options, ("--icmp-type", &fwlib::get_srv_port($dst_ports, 3, "ICMP")));
632 } else {
633 $dst_ports = &fwlib::get_srv_port($dst_ports, 1, uc($protocol));
634 push(@options, &format_ports($dst_ports, "dst"));
635 }
636
637 } elsif ($dst_ports_mode eq "cust_srvgrp") {
638 push(@options, &fwlib::get_srvgrp_port($dst_ports, uc($protocol)));
639 }
640 }
641 }
642
643 # Check if a single ICMP type is selected.
644 if ($protocol eq "icmp") {
645 my $icmp_type = $$hash{$key}[9];
646
647 if (($icmp_type ne "All ICMP-Types") && $icmp_type) {
648 push(@options, ("--icmp-type", $icmp_type));
649 }
650 }
651
652 return @options;
653 }
654
655 sub format_ports {
656 my $ports = shift;
657 my $type = shift;
658
659 my $arg;
660 if ($type eq "src") {
661 $arg = "--sport";
662 } elsif ($type eq "dst") {
663 $arg = "--dport";
664 }
665
666 my @options = ();
667
668 if ($ports =~ /\|/) {
669 $ports =~ s/\|/,/g;
670 push(@options, ("-m", "multiport"));
671 }
672
673 if ($ports) {
674 push(@options, ($arg, $ports));
675 }
676
677 return @options;
678 }
679
680 sub get_dnat_target_port {
681 my $hash = shift;
682 my $key = shift;
683
684 if ($$hash{$key}[14] eq "TGT_PORT") {
685 my $port = $$hash{$key}[15];
686 my $external_port = $$hash{$key}[30];
687
688 if ($external_port && ($port ne $external_port)) {
689 return $$hash{$key}[15];
690 }
691 }
692 }
693
694 sub add_dnat_mangle_rules {
695 my $nat_address = shift;
696 my $interface = shift;
697 my @options = @_;
698
699 my $mark = 0;
700 foreach my $zone ("GREEN", "BLUE", "ORANGE") {
701 $mark++;
702
703 # Skip rule if not all required information exists.
704 next unless (exists $defaultNetworks{$zone . "_NETADDRESS"});
705 next unless (exists $defaultNetworks{$zone . "_NETMASK"});
706
707 next if ($interface && $interface ne $defaultNetworks{$zone . "_DEV"});
708
709 my @mangle_options = @options;
710
711 my $netaddress = $defaultNetworks{$zone . "_NETADDRESS"};
712 $netaddress .= "/" . $defaultNetworks{$zone . "_NETMASK"};
713
714 push(@mangle_options, ("-s", $netaddress, "-d", $nat_address));
715 push(@mangle_options, ("-j", "MARK", "--set-mark", $mark));
716
717 run("$IPTABLES -t mangle -A $CHAIN_MANGLE_NAT_DESTINATION_FIX @mangle_options");
718 }
719 }
720
721 sub make_log_limit_options {
722 my @options = ("-m", "limit");
723
724 # Maybe we should get this from the configuration.
725 my $limit = 10;
726
727 # We limit log messages to $limit messages per minute.
728 push(@options, ("--limit", "$limit/min"));
729
730 # And we allow bursts of 2x $limit.
731 push(@options, ("--limit-burst", $limit * 2));
732
733 return @options;
734 }
735
736 sub firewall_is_in_subnet {
737 my $subnet = shift;
738
739 # ORANGE is missing here, because nothing may ever access
740 # the firewall from this network.
741 my $address = &fwlib::get_internal_firewall_ip_address($subnet, 0);
742
743 if ($address) {
744 return 1;
745 }
746
747 return 0;
748 }