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git.ipfire.org Git - people/pmueller/ipfire-2.x.git/blob - config/guardian/guardian.pl
2 # based on V 1.7 guardian enhanced for IPFire and snort 2.8
3 # Read the readme file for changes
5 # Enhanced for IPFire by IPFire Team
6 # Added Portscan detection for non syslog system
7 # Added SSH-Watch for SSH-Bruteforce Attacks
8 # An suppected IP will be blocked on all interfaces
12 print "OS shows $OS\n";
17 if (defined($opt_h)) {
18 print "Guardian v1.7 \n";
19 print "guardian.pl [-hd] <-c config>\n";
20 print " -h shows help\n";
21 print " -d run in debug mode (doesn't fork, output goes to STDOUT)\n";
22 print " -c specifiy a configuration file other than the default (/etc/guardian.conf)\n";
28 print "My ip address and interface are: $hostipaddr $interface\n";
30 if ($hostipaddr !~ /\d+\.\d+\.\d+\.\d+/) {
31 print "This ip address is bad : $hostipaddr\n";
32 die "I need a good host ipaddress\n";
35 $networkaddr = $hostipaddr;
36 $networkaddr =~ s/\d+$/0/;
37 $gatewayaddr = `cat /var/ipfire/red/remote-ipaddress 2>/dev/null`;
38 $broadcastaddr = $hostipaddr;
39 $broadcastaddr =~ s/\d+$/255/;
42 print "My gatewayaddess is: $gatewayaddr\n";
44 # This is the target hash. If a packet was destened to any of these, then the
45 # sender of that packet will get denied, unless it is on the ignore list..
47 %targethash = ( "$networkaddr" => 1,
48 "$broadcastaddr" => 1,
49 "0" => 1, # This is what gets sent to &checkem if no
50 # destination was found.
55 if ( -e
$targetfile ) {
59 if (!defined($opt_d)) {
60 print "Becoming a daemon..\n";
62 } else { print "Running in debug mode..\n"; }
64 open (ALERT
, $alert_file) or die "can't open alert file: $alert_file: $!\n";
65 seek (ALERT
, 0, 2); # set the position to EOF.
66 # this is the same as a tail -f :)
68 open (ALERT2
, "/var/log/messages" ) or die "can't open /var/log/messages: $!\n";
69 seek (ALERT2
, 0, 2); # set the position to EOF.
70 # this is the same as a tail -f :)
77 if (defined($opt_d)) {
80 if (/\[\*\*\]\s+(.*)\s+\[\*\*\]/){
83 if (/(\d+\.\d+\.\d+\.\d+):\d+ -\> (\d+\.\d+\.\d+\.\d+):\d+/) {
84 &checkem
($1, $2, $type);
86 if (/(\d+\.\d+\.\d+\.\d+)+ -\> (\d+\.\d+\.\d+\.\d+)+/) {
87 &checkem
($1, $2, $type);
93 if (seek(ALERT2
,0,1)){
96 if ($_=~/.*sshd.*Failed password for root from.*/) {
97 my @array=split(/ /,$_);&checkssh
($array[10], "possible SSH-Bruteforce Attack");}
101 # Run this stuff every 30 seconds..
102 if ($counter == 30) {
103 &remove_blocks
; # This might get moved elsewhere, depending on how much load
104 # it puts on the system..
113 my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
114 $atime,$mtime,$ctime,$blksize,$blocks) = stat($alert_file);
115 if ($size < $previous_size) { # The filesize is smaller than last
116 close (ALERT
); # we checked, so we need to reopen it
117 open (ALERT
, "$alert_file"); # This should still work in our main while
118 $previous_size=$size; # loop (I hope)
119 write_log
("Log filename changed. Reopening $alert_file\n");
121 $previous_size=$size;
127 my ($source, $dest,$type) = @_;
130 return 1 if ($source eq $hostipaddr);
131 # this should prevent is from nuking ourselves
133 return 1 if ($source eq $gatewayaddr); # or our gateway
134 if ($ignore{$source} == 1) { # check our ignore list..
135 &write_log
("$source\t$type\n");
136 &write_log
("Ignoring attack because $source is in my ignore list\n");
140 # if the offending packet was sent to us, the network, or the broadcast, then
141 if ($targethash{$dest} == 1) {
142 &ipchain
($source, $dest, $type);
144 # you will see this if the destination was not in the $targethash, and the
145 # packet was not ignored before the target check..
147 &write_log
("Odd.. source = $source, dest = $dest - No action done.\n");
148 if (defined ($opt_d)) {
149 foreach $key (keys %targethash) {
150 &write_log
("targethash{$key} = $targethash{$key}\n");
157 my ($source,$type) = @_;
160 return 1 if ($source eq $hostipaddr);
161 # this should prevent is from nuking ourselves
163 return 1 if ($source eq $gatewayaddr); # or our gateway
165 if ($sshhash{$dest} eq "" ){
168 if ($sshhash{$dest} >= 3 ) {
169 &write_log
("source = $source, count $sshhash{$dest} - blocking for ssh attack.\n");
170 &ipchain
($source, "", $type);
172 # you will see this if the destination was not in the $sshhash, and the
173 # packet was not ignored before the target check..
175 &write_log
("Odd.. source = $source, ssh count only $sshhash{$dest} - No action done.\n");
176 if (defined ($opt_d)) {
177 foreach $key (keys %sshhash) {
178 &write_log
("sshhash{$key} = %sshhash{$key}\n");
181 $sshhash{$key} = $sshhash{$key}+1;
186 my ($source, $dest, $type) = @_;
187 &write_log
("$source\t$type\n");
188 if ($hash{$source} eq "") {
189 &write_log
("Running '$blockpath $source'\n");
190 system ("$blockpath $source");
191 $hash{$source} = time() + $TimeLimit;
193 # We have already blocked this one, but snort detected another attack. So
194 # we should update the time blocked..
195 $hash{$source} = time() + $TimeLimit;
199 sub build_ignore_hash
{
200 # This would cause is to ignore all broadcasts if it
201 # got set.. However if unset, then the attacker could spoof the packet to make
202 # it look like it came from the network, and a reply to the spoofed packet
203 # could be seen if the attacker were on the local network.
204 # $ignore{$networkaddr}=1;
206 # same thing as above, just with the broadcast instead of the network.
207 # $ignore{$broadcastaddr}=1;
209 $ignore{$gatewayaddr}=1;
210 $ignore{$hostipaddr}=1;
211 if ($ignorefile ne "") {
212 open (IGNORE
, $ignorefile);
216 next if (/\#/); #skip comments
217 next if (/^\s*$/); # and blank lines
222 print "Loaded $count addresses from $ignorefile\n";
224 print "No ignore file was loaded!\n";
230 $opt_c = "/etc/guardian.conf";
234 die "Need a configuration file.. please use to the -c option to name a configuration file\n";
237 open (CONF
, $opt_c) or die "Cannot read the config file $opt_c, $!\n";
240 next if (/^\s*$/); #skip blank lines
241 next if (/^#/); # skip comment lines
242 if (/LogFile\s+(.*)/) {
245 if (/Interface\s+(.*)/) {
248 if (/AlertFile\s+(.*)/) {
251 if (/IgnoreFile\s+(.*)/) {
254 if (/TargetFile\s+(.*)/) {
257 if (/TimeLimit\s+(.*)/) {
260 if (/HostIpAddr\s+(.*)/) {
263 if (/HostGatewayByte\s+(.*)/) {
264 $hostgatewaybyte = $1;
268 if ($interface eq "") {
269 die "Fatal! Interface is undefined.. Please define it in $opt_o with keyword Interface\n";
271 if ($alert_file eq "") {
272 print "Warning! AlertFile is undefined.. Assuming /var/log/snort.alert\n";
273 $alert_file="/var/log/snort.alert";
275 if ($hostipaddr eq "") {
276 print "Warning! HostIpAddr is undefined! Attempting to guess..\n";
277 $hostipaddr = &get_ip
($interface);
278 print "Got it.. your HostIpAddr is $hostipaddr\n";
280 if ($ignorefile eq "") {
281 print "Warning! IgnoreFile is undefined.. going with default ignore list (hostname and gateway)!\n";
283 if ($hostgatewaybyte eq "") {
284 print "Warning! HostGatewayByte is undefined.. gateway will not be in ignore list!\n";
286 if ($logfile eq "") {
287 print "Warning! LogFile is undefined.. Assuming debug mode, output to STDOUT\n";
291 print "Warning! Logfile is not writeable! Engaging debug mode, output to STDOUT\n";
295 foreach $mypath (split (/:/, $ENV{PATH
})) {
296 if (-x
"$mypath/guardian_block.sh") {
297 $blockpath = "$mypath/guardian_block.sh";
299 if (-x
"$mypath/guardian_unblock.sh") {
300 $unblockpath = "$mypath/guardian_unblock.sh";
304 if ($blockpath eq "") {
305 print "Error! Could not find guardian_block.sh. Please consult the README. \n";
308 if ($unblockpath eq "") {
309 print "Warning! Could not find guardian_unblock.sh. Guardian will not be\n";
310 print "able to remove blocked ip addresses. Please consult the README file\n";
312 if ($TimeLimit eq "") {
313 print "Warning! Time limit not defined. Defaulting to absurdly long time limit\n";
314 $TimeLimit = 999999999;
320 my $date = localtime();
321 if (defined($opt_d)) { # we are in debug mode, and not daemonized
322 print STDOUT
$message;
324 open (LOG
, ">>$logfile");
325 print LOG
$date.": ".$message;
337 &write_log
("Guardian process id $$\n");
338 $home = (getpwuid($>))[7] || die "No home directory!\n";
339 chdir($home); # go to my homedir
340 setpgrp(0,0); # become process leader
344 print "Testing...\n";
349 my ($interface) = $_[0];
351 open (IFCONFIG
, "/bin/netstat -iee |grep $interface -A7 |");
353 if ($OS eq "FreeBSD") {
354 if (/inet (\d+\.\d+\.\d+\.\d+)/) {
358 if ($OS eq "Linux") {
359 if (/inet addr:(\d+\.\d+\.\d+\.\d+)/) {
366 if ($ip eq "") { die "Couldn't figure out the ip address\n"; }
370 sub sig_handler_setup
{
371 $SIG{TERM
} = \
&clean_up_and_exit
; # kill
372 $SIG{QUIT
} = \
&clean_up_and_exit
; # kill -3
373 # $SIG{HUP} = \&flush_and_reload; # kill -1
379 foreach $source (keys %hash) {
380 if ($hash{$source} < $time) {
381 &call_unblock
($source, "expiring block of $source\n");
382 delete ($hash{$source});
388 my ($source, $message) = @_;
389 &write_log
("$message");
390 system ("$unblockpath $source");
393 sub clean_up_and_exit
{
395 &write_log
("received kill sig.. shutting down\n");
396 foreach $source (keys %hash) {
397 &call_unblock
($source, "removing $source for shutdown\n");
402 sub load_targetfile
{
404 open (TARG
, "$targetfile") or die "Cannot open $targetfile\n";
407 next if (/\#/); #skip comments
408 next if (/^\s*$/); # and blank lines
413 print "Loaded $count addresses from $targetfile\n";