1: # The LearningOnline Network with CAPA
2: # Firewall configuration to allow internal LON-CAPA communication between servers
3: #
4: # $Id: Firewall.pm,v 1.15 2018/10/24 02:08:04 raeburn Exp $
5: #
6: # The LearningOnline Network with CAPA
7: #
8: # Copyright Michigan State University Board of Trustees
9: #
10: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
11: #
12: # LON-CAPA is free software; you can redistribute it and/or modify
13: # it under the terms of the GNU General Public License as published by
14: # the Free Software Foundation; either version 2 of the License, or
15: # (at your option) any later version.
16: #
17: # LON-CAPA is distributed in the hope that it will be useful,
18: # but WITHOUT ANY WARRANTY; without even the implied warranty of
19: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20: # GNU General Public License for more details.
21: #
22: # You should have received a copy of the GNU General Public License
23: # along with LON-CAPA; if not, write to the Free Software
24: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25: #
26: # /home/httpd/html/adm/gpl.txt
27: #
28: # http://www.lon-capa.org/
29: #
30: # Startup script for the LON-CAPA network processes
31: #
32:
33: package LONCAPA::Firewall;
34:
35: use strict;
36: use lib '/home/httpd/perl/lib';
37: use LONCAPA::Configuration;
38: use LONCAPA;
39:
40: sub uses_firewalld {
41: my ($distro) = @_;
42: if ($distro eq '') {
43: $distro = &get_distro();
44: }
45: my ($inuse, $checkfirewalld);
46: if ($distro =~ /^(suse|sles)([\d\.]+)$/) {
47: if (($1 eq 'sles') && ($2 >= 15)) {
48: $checkfirewalld = 1;
49: }
50: } elsif ($distro =~ /^fedora(\d+)$/) {
51: if ($1 >= 18) {
52: $checkfirewalld = 1;
53: }
54: } elsif ($distro =~ /^(?:centos|rhes|scientific)(\d+)/) {
55: if ($1 >= 7) {
56: $checkfirewalld = 1;
57: }
58: }
59: if ($checkfirewalld) {
60: my ($loaded,$active);
61: if (open(PIPE,"systemctl status firewalld |")) {
62: while (<PIPE>) {
63: chomp();
64: if (/^\s*Loaded:\s+(\w+)/) {
65: $loaded = $1;
66: }
67: if (/^\s*Active\s+(\w+)/) {
68: $active = $1;
69: }
70: }
71: close(PIPE);
72: }
73: if (($loaded eq 'loaded') || ($active eq 'active')) {
74: $inuse = 1;
75: }
76: }
77: return $inuse;
78: }
79:
80: sub firewall_open_port {
81: my ($iptables,$fw_chains,$lond_port,$iphost,$ports) = @_;
82: return 'inactive firewall' if (!&firewall_is_active());
83: return 'port number unknown' if !$lond_port;
84: return 'invalid firewall chain' unless (ref($fw_chains) eq 'ARRAY');
85: my (@opened,@chains,@badchains,@okchains);
86: foreach my $chain (@{$fw_chains}) {
87: if ($chain =~ /^([\w\-]+)$/) {
88: push(@okchains,$1);
89: } else {
90: push(@badchains,$chain);
91: }
92: }
93: if (!@okchains) {
94: return 'None of the chain names has the expected format.'."\n";
95: }
96: if (ref($ports) ne 'ARRAY') {
97: return 'List of ports to open needed.';
98: }
99: my $firewalld = &uses_firewalld();
100: foreach my $portnum (@{$ports}) {
101: my $port = '';
102: if ($portnum =~ /^(\d+)$/) {
103: $port = $1;
104: } else {
105: print "Skipped non-numeric port: $portnum.\n";
106: next;
107: }
108: print "Opening firewall access on port $port.\n";
109: my $result;
110: if ($port eq $lond_port) {
111: # For lond port, restrict the servers allowed to attempt to communicate
112: # to include only source IPs in the LON-CAPA cluster.
113: my (@port_error,%command_error,@lond_port_open,
114: @lond_port_curropen);
115: if (ref($iphost) eq 'HASH') {
116: if (keys(%{$iphost}) > 0) {
117: my %curropen;
118: foreach my $fw_chain (@okchains) {
119: &firewall_close_anywhere($iptables,$fw_chain,$port);
120: my $current = &firewall_is_port_open($iptables,$fw_chain,$port,$lond_port,$iphost,\%curropen);
121: }
122: foreach my $key (keys(%{$iphost})) {
123: my $ip = '';
124: if ($key =~ /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/) {
125: if (($1<=255) && ($2<=255) && ($3<=255) && ($4<=255)) {
126: $ip = "$1.$2.$3.$4";
127: } else {
128: print "IP address: $key does not have expected format.\n";
129: next;
130: }
131: } else {
132: print "IP address: $key does not have expected format.\n";
133: next;
134: }
135: if ($curropen{$ip}) {
136: push(@lond_port_curropen,$ip);
137: } else {
138: foreach my $fw_chain (@okchains) {
139: if ($firewalld) {
140: my $cmd = 'firewall-cmd --zone=public --add-rich-rule \'rule family="ipv4" source address="'.$ip.'/32" port port="'.$port.'" protocol="tcp" accept\'';
141: if (open(PIPE,"$cmd |")) {
142: my $result = <PIPE>;
143: chomp($result);
144: close(PIPE);
145: if ($result eq 'success') {
146: push(@lond_port_open,$ip);
147: last;
148: } else {
149: push (@port_error,$ip);
150: }
151: } else {
152: push (@port_error,$ip);
153: }
154: } else {
155: my $firewall_command =
156: "$iptables -I $fw_chain -p tcp -s $ip -d 0/0 --dport $port -j ACCEPT";
157: system($firewall_command);
158: my $return_status = $?>>8;
159: if ($return_status == 1) {
160: unless(grep(/^\Q$ip\E$/,@port_error)) {
161: push (@port_error,$ip);
162: }
163: } elsif ($return_status == 2) {
164: push(@{$command_error{$fw_chain}},$ip);
165: } elsif ($return_status == 0) {
166: push(@lond_port_open,$ip);
167: last;
168: }
169: }
170: }
171: }
172: }
173: } else {
174: print "no key found in $iphost hash ref\n";
175: }
176: } else {
177: print "$iphost is not a reference to a hash\n";
178: }
179: if (@lond_port_curropen) {
180: unless (grep(/^\Q$port\E$/,@opened)) {
181: push(@opened,$port);
182: }
183: print "Port already open for ".scalar(@lond_port_curropen)." IP addresses.\n";
184: }
185: if (@lond_port_open) {
186: unless (grep(/^\Q$port\E$/,@opened)) {
187: push(@opened,$port);
188: }
189: print "Port opened for ".scalar(@lond_port_open)." IP addresses.\n";
190: }
191: if (@port_error) {
192: print "Error opening port for following IP addresses: ".join(', ',@port_error)."\n";
193: }
194: if (keys(%command_error) > 0) {
195: foreach my $chain (sort(keys(%command_error))) {
196: if (ref($command_error{$chain}) eq 'ARRAY') {
197: if (@{$command_error{$chain}}) {
198: print "Bad command error opening port for following IP addresses: ".
199: join(', ',@{$command_error{$chain}})."\n".
200: 'Command was: "'."$iptables -I $chain -p tcp -s ".'$ip'." -d 0/0 --dport $port -j ACCEPT".'", where $ip is IP address'."\n";
201: }
202: }
203: }
204: }
205: } else {
206: my (@port_errors,%command_errors);
207: foreach my $fw_chain (@okchains) {
208: if ($firewalld) {
209: my $cmd = 'firewall-cmd --zone=public --add-rich-rule \'rule family="ipv4" port port="'.$port.'" protocol="tcp" accept\'';
210: if (open(PIPE,"$cmd |")) {
211: my $result = <PIPE>;
212: chomp($result);
213: close(PIPE);
214: if ($result eq 'success') {
215: push(@opened,$port);
216: last;
217: } else {
218: push(@port_errors,$fw_chain);
219: }
220: } else {
221: push(@port_errors,$fw_chain);
222: }
223: } else {
224: my $firewall_command =
225: "$iptables -I $fw_chain -p tcp -d 0/0 --dport $port -j ACCEPT";
226: system($firewall_command);
227: my $return_status = $?>>8;
228: if ($return_status == 1) {
229: push(@port_errors,$fw_chain);
230: } elsif ($return_status == 2) {
231: $command_errors{$fw_chain} = $firewall_command;
232: } elsif ($return_status == 0) {
233: push(@opened,$port);
234: last;
235: }
236: }
237: unless (grep(/^\Q$port\E$/,@opened)) {
238: if (@port_errors) {
239: print "Error opening port for chains: ".
240: join(', ',@port_errors).".\n";
241: }
242: if (keys(%command_errors)) {
243: foreach my $fw_chain (sort(keys(%command_errors))) {
244: print "Bad command error opening port for chain: $fw_chain. Command was\n".
245: " ".$command_errors{$fw_chain}."\n";
246: }
247: }
248: }
249: }
250: }
251: }
252: foreach my $port (@{$ports}) {
253: if (!grep(/^\Q$port\E$/,@opened)) {
254: return 'Required port not open: '.$port."\n";
255: }
256: }
257: return 'ok';
258: }
259:
260: sub firewall_is_port_open {
261: my ($iptables,$fw_chain,$port,$lond_port,$iphost,$curropen) = @_;
262: # for lond port returns number of source IPs for which firewall port is open
263: # for other ports returns 1 if the firewall port is open, 0 if not.
264: #
265: # check if firewall is active or installed
266: return if (! &firewall_is_active());
267: my $count = 0;
268: if (open(PIPE,"$iptables -L $fw_chain -n |")) {
269: while(<PIPE>) {
270: if ($port eq $lond_port) {
271: if (ref($iphost) eq 'HASH') {
272: if (/^ACCEPT\s+tcp\s+\-{2}\s+(\S+)\s+\S+\s+tcp\s+dpt\:\Q$port\E/) {
273: my $ip = $1;
274: if ($iphost->{$ip}) {
275: $count ++;
276: if (ref($curropen) eq 'HASH') {
277: $curropen->{$ip} ++;
278: }
279: }
280: }
281: }
282: } else {
283: if (/tcp dpt\:\Q$port\E/) {
284: $count ++;
285: last;
286: }
287: }
288: }
289: close(PIPE);
290: }
291: return $count;
292: }
293:
294: sub firewall_is_active {
295: my $status = 0;
296: if (-e '/proc/net/ip_tables_names') {
297: if (open(PIPE,'cat /proc/net/ip_tables_names |')) {
298: while(<PIPE>) {
299: chomp();
300: if (/^filter$/) {
301: $status = 1;
302: last;
303: }
304: }
305: close(PIPE);
306: }
307: }
308: return $status;
309: }
310:
311: sub firewall_close_port {
312: my ($iptables,$fw_chains,$lond_port,$iphost,$ports) = @_;
313: return 'inactive firewall' if (!&firewall_is_active());
314: return 'port number unknown' if !$lond_port;
315: return 'invalid firewall chain' unless (ref($fw_chains) eq 'ARRAY');
316: my (@opened,@chains,@badchains,@okchains);
317: foreach my $chain (@{$fw_chains}) {
318: if ($chain =~ /^([\w\-]+)$/) {
319: push(@okchains,$1);
320: } else {
321: push(@badchains,$chain);
322: }
323: }
324: if (!@okchains) {
325: return 'None of the chain names has the expected format.'."\n";
326: }
327: if (ref($ports) ne 'ARRAY') {
328: return 'List of ports to close needed.';
329: }
330: my $firewalld = &uses_firewalld();
331: foreach my $portnum (@{$ports}) {
332: my $port = '';
333: if ($portnum =~ /^(\d+)$/) {
334: $port = $1;
335: } else {
336: print "Skipped non-numeric port: $portnum\n";
337: next;
338: }
339: print "Closing firewall access on port $port.\n";
340: if (($port ne '') && ($port eq $lond_port)) {
341: my $output;
342: foreach my $fw_chain (@okchains) {
343: my (@port_error,@command_error,@lond_port_close);
344: my %to_close;
345: if (open(PIPE, "$iptables -n -L $fw_chain |")) {
346: while (<PIPE>) {
347: chomp();
348: next unless (/dpt:\Q$port\E/);
349: if (/^ACCEPT\s+tcp\s+\-{2}\s+(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})\s+/) {
350: my $ip = $1;
351: my $keepopen = 0;
352: if (ref($iphost) eq 'HASH') {
353: if (exists($iphost->{$ip})) {
354: $keepopen = 1;
355: }
356: }
357: unless ($keepopen) {
358: $to_close{$ip} = $port;
359: }
360: }
361: }
362: close(PIPE);
363: }
364: if (keys(%to_close) > 0) {
365: foreach my $ip (keys(%to_close)) {
366: if ($firewalld) {
367: my $cmd = 'firewall-cmd --zone=public --remove-rich-rule \'rule family="ipv4" source address="'.$ip.'/32" port port="'.$port.'" protocol="tcp" accept\'';
368: if (open(PIPE,"$cmd |")) {
369: my $result = <PIPE>;
370: chomp($result);
371: close(PIPE);
372: if ($result eq 'success') {
373: push(@lond_port_close,$ip);
374: } else {
375: push(@port_error,$ip);
376: }
377: } else {
378: push(@port_error,$ip);
379: }
380: } else {
381: my $firewall_command =
382: "$iptables -D $fw_chain -p tcp -s $ip -d 0/0 --dport $port -j ACCEPT";
383: system($firewall_command);
384: my $return_status = $?>>8;
385: if ($return_status == 1) {
386: push (@port_error,$ip);
387: } elsif ($return_status == 2) {
388: push(@command_error,$ip);
389: } elsif ($return_status == 0) {
390: push(@lond_port_close,$ip);
391: }
392: }
393: }
394: }
395: if (@lond_port_close) {
396: $output .= "Port closed for ".scalar(@lond_port_close)." IP addresses.\n";
397: }
398: if (@port_error) {
399: $output .= "Error closing port for following IP addresses: ".join(', ',@port_error)."\n";
400: }
401: if (@command_error) {
402: $output .= "Bad command error opening port for following IP addresses: ".
403: join(', ',@command_error)."\n".
404: 'Command was: "'."$iptables -D $fw_chain -p tcp -s ".'$ip'." -d 0/0 --dport $port -j ACCEPT".'", where $ip is IP address'."\n";
405: }
406: }
407: if ($output) {
408: print $output;
409: } else {
410: print "No IP addresses required discontinuation of access.\n";
411: }
412: } else {
413: foreach my $fw_chain (@okchains) {
414: my (@port_error,@command_error,@lond_port_close);
415: my $to_close;
416: if (open(PIPE, "$iptables -n -L $fw_chain |")) {
417: while (<PIPE>) {
418: chomp();
419: next unless (/dpt:\Q$port\E/);
420: $to_close = 1;
421: }
422: close(PIPE);
423: }
424: if ($to_close) {
425: if ($firewalld) {
426: my $cmd = 'firewall-cmd --zone=public --remove-rich-rule \'rule family="ipv4" port port="'.$port.'" protocol="tcp" accept\'';
427: if (open(PIPE,"$cmd|")) {
428: my $result = <PIPE>;
429: chomp($result);
430: close(PIPE);
431: if ($result eq 'success') {
432: print "Port closed for chain $fw_chain.\n";
433: } else {
434: print "Error closing port for chain: $fw_chain.\n";
435: }
436: } else {
437: print "Error closing port for chain: $fw_chain.\n";
438: }
439: } else {
440: my $firewall_command =
441: "$iptables -D $fw_chain -p tcp -d 0/0 --dport $port -j ACCEPT";
442: system($firewall_command);
443: my $return_status = $?>>8;
444: if ($return_status == 1) {
445: # Error
446: print "Error closing port for chain: $fw_chain.\n";
447: } elsif ($return_status == 2) {
448: # Bad command
449: print "Bad command error closing port. Command was\n".
450: " ".$firewall_command."\n";
451: } else {
452: print "Port closed for chain $fw_chain.\n";
453: }
454: }
455: }
456: }
457: }
458: }
459: return;
460: }
461:
462: sub firewall_close_anywhere {
463: my ($iptables,$fw_chain,$port) = @_;
464: my $firewalld = &uses_firewalld();
465: if (open(PIPE, "$iptables --line-numbers -n -L $fw_chain |")) {
466: while (<PIPE>) {
467: next unless (/dpt:\Q$port\E/);
468: chomp();
469: if (/^(\d+)\s+ACCEPT\s+tcp\s+\-{2}\s+0\.0\.0\.0\/0\s+0\.0\.0\.0\/0/) {
470: if ($firewalld) {
471: my $cmd = 'firewall-cmd --remove-port='.$port.'/tcp';
472: if (open(PIPE,"$cmd |")) {
473: my $result = <PIPE>;
474: chomp($result);
475: close(PIPE);
476: if ($result eq 'success') {
477: print 'Port '.$port.' closed for source "anywhere"'."\n";
478: } else {
479: print 'Error closing port '.$port.' for source "anywhere".'."\n";
480: }
481: } else {
482: print 'Error closing port '.$port.' for source "anywhere".'."\n";
483: }
484: } else {
485: my $firewall_command = "$iptables -D $fw_chain $1";
486: system($firewall_command);
487: my $return_status = $?>>8;
488: if ($return_status == 1) {
489: print 'Error closing port '.$port.' for source "anywhere".'."\n";
490: } elsif ($return_status == 2) {
491: print 'Bad command error closing port '.$port.' for source "anywhere". Command was'."\n".
492: ' '.$firewall_command."\n";
493: } else {
494: print 'Port '.$port.' closed for source "anywhere"'."\n";
495: }
496: }
497: }
498: }
499: close(PIPE);
500: }
501: }
502:
503: sub get_lond_port {
504: my $perlvarref=&LONCAPA::Configuration::read_conf();
505: my $lond_port;
506: if (ref($perlvarref) eq 'HASH') {
507: if (defined($perlvarref->{'londPort'})) {
508: $lond_port = $perlvarref->{'londPort'};
509: }
510: }
511: if (!$lond_port) {
512: print("Unable to determine lond port number from LON-CAPA configuration.\n");
513: }
514: return $lond_port;
515: }
516:
517: sub get_fw_chains {
518: my ($iptables,$distro) = @_;
519: if ($distro eq '') {
520: $distro = &get_distro();
521: }
522: my @fw_chains;
523: my $suse_config = "/etc/sysconfig/SuSEfirewall2";
524: my $ubuntu_config = "/etc/ufw/ufw.conf";
525: if (&uses_firewalld($distro)) {
526: push(@fw_chains,'IN_public_allow');
527: } elsif (-e $suse_config) {
528: push(@fw_chains,'input_ext');
529: } else {
530: my @posschains;
531: if (-e $ubuntu_config) {
532: @posschains = ('ufw-user-input','INPUT');
533: } else {
534: if ($distro =~ /^(debian|ubuntu|suse|sles)/) {
535: @posschains = ('INPUT');
536: } elsif ($distro =~ /^(fedora|rhes|centos|scientific)(\d+)$/) {
537: if ((($1 eq 'fedora') && ($2 > 15)) || (($1 ne 'fedora') && ($2 >= 7))) {
538: @posschains = ('INPUT');
539: } else {
540: @posschains = ('RH-Firewall-1-INPUT','INPUT');
541: }
542: }
543: if (!-e '/etc/sysconfig/iptables') {
544: if (!-e '/var/lib/iptables') {
545: unless ($distro =~ /^(debian|ubuntu)/) {
546: print("Unable to find iptables file containing static definitions.\n");
547: }
548: }
549: if ($distro =~ /^(fedora|rhes|centos|scientific)(\d+)$/) {
550: unless ((($1 eq 'fedora') && ($2 > 15)) || (($1 ne 'fedora') && ($2 >= 7))) {
551: push(@fw_chains,'RH-Firewall-1-INPUT');
552: }
553: }
554: }
555: }
556: if ($iptables eq '') {
557: $iptables = &get_pathto_iptables();
558: }
559: my %counts;
560: if (open(PIPE,"$iptables -L -n |")) {
561: while(<PIPE>) {
562: foreach my $chain (@posschains) {
563: if (/(\Q$chain\E)/) {
564: $counts{$1} ++;
565: }
566: }
567: }
568: close(PIPE);
569: }
570: foreach my $fw_chain (@posschains) {
571: if ($counts{$fw_chain}) {
572: unless(grep(/^\Q$fw_chain\E$/,@fw_chains)) {
573: push(@fw_chains,$fw_chain);
574: }
575: }
576: }
577: }
578: return @fw_chains;
579: }
580:
581: sub get_pathto_iptables {
582: my $iptables;
583: if (-e '/sbin/iptables') {
584: $iptables = '/sbin/iptables';
585: } elsif (-e '/usr/sbin/iptables') {
586: $iptables = '/usr/sbin/iptables';
587: } else {
588: print("Unable to find iptables command.\n");
589: }
590: return $iptables;
591: }
592:
593: sub get_distro {
594: my $distro;
595: if (open(PIPE,"/home/httpd/perl/distprobe |")) {
596: $distro = <PIPE>;
597: close(PIPE);
598: }
599: return $distro;
600: }
601:
602: 1;
603: __END__
604:
605: =pod
606:
607: =head1 NAME
608:
609: B<LONCAPA::Firewall> - dynamic opening/closing of firewall ports
610:
611: =head1 SYNOPSIS
612:
613: use lib '/home/httpd/lib/perl/';
614: use LONCAPA::Firewall;
615:
616: LONCAPA::Firewall::uses_firewalld();
617: LONCAPA::Firewall::firewall_open_port();
618: LONCAPA::Firewall::firewall_close_port();
619: LONCAPA::Firewall::firewall_is_port_open();
620: LONCAPA::Firewall::firewall_is_active();
621: LONCAPA::Firewall::firewall_close_anywhere();
622:
623: =head1 DESCRIPTION
624:
625: The scripts: /etc/init.d/loncontrol, used to stop or start LON-CAPA services,
626: as well as the setuid script /home/httpd/perl/lciptables, called by loncron
627: for housekeeping tasks, make use of the methods provided by this module to
628: open and close firewall ports (currently the default port: 5663), used
629: for socket-based communication between LON-CAPA servers in the cluster
630: of networked servers to which the server belongs.
631:
632: The following methods are available:
633:
634: =over 4
635:
636: =item LONCAPA::Firewall::uses_firewalld( $distro );
637:
638: =back
639:
640: =over 4
641:
642: =item LONCAPA::Firewall::firewall_open_port( $iptables,$fw_chains,$lond_port,$iphost,$port );
643:
644: =back
645:
646: =over 4
647:
648: =item LONCAPA::Firewall::firewall_close_port( $iptables,$fw_chains,$lond_port,$iphost,$ports );
649:
650: =back
651:
652: =over 4
653:
654: =item LONCAPA::Firewall::firewall_is_port_open( $iptables,$fw_chain,$port,$lond_port,$iphost,$curropen );
655:
656: =back
657:
658: =over 4
659:
660: =item LONCAPA::Firewall::firewall_is_active();
661:
662: =back
663:
664: =over 4
665:
666: =item LONCAPA::Firewall::firewall_close_anywhere( $iptables,$fw_chain,$port );
667:
668: =back
669:
670: =over 4
671:
672: =item LONCAPA::Firewall::get_lond_port();
673:
674: =back
675:
676: =over 4
677:
678: =item LONCAPA::Firewall::get_fw_chains( $iptables,$distro );
679:
680: =back
681:
682: =over 4
683:
684: =item LONCAPA::Firewall::get_pathto_iptables();
685:
686: =back
687:
688: =over 4
689:
690: =item LONCAPA::Firewall::get_distro();
691:
692: =back
693:
694: =head1 AUTHORS
695:
696: This library is free software; you can redistribute it and/or
697: modify it under the same terms as LON-CAPA itself.
698:
699: =cut
700:
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