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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 = $hostipaddr;
38 $gatewayaddr =~ s/\d+$/$hostgatewaybyte/;
39 $broadcastaddr = $hostipaddr;
40 $broadcastaddr =~ s/\d+$/255/;
43 # This is the target hash. If a packet was destened to any of these, then the
44 # sender of that packet will get denied, unless it is on the ignore list..
46 %targethash = ( "$networkaddr" => 1,
47 "$broadcastaddr" => 1,
48 "0" => 1, # This is what gets sent to &checkem if no
49 # destination was found.
54 if ( -e
$targetfile ) {
58 if (!defined($opt_d)) {
59 print "Becoming a daemon..\n";
61 } else { print "Running in debug mode..\n"; }
63 open (ALERT
, $alert_file) or die "can't open alert file: $alert_file: $!\n";
64 seek (ALERT
, 0, 2); # set the position to EOF.
65 # this is the same as a tail -f :)
67 open (ALERT2
, "/var/log/messages" ) or die "can't open /var/log/messages: $!\n";
68 seek (ALERT2
, 0, 2); # set the position to EOF.
69 # this is the same as a tail -f :)
76 if (defined($opt_d)) {
79 if (/\[\*\*\]\s+(.*)\s+\[\*\*\]/){
82 if (/(\d+\.\d+\.\d+\.\d+):\d+ -\> (\d+\.\d+\.\d+\.\d+):\d+/) {
83 &checkem
($1, $2, $type);
85 if (/(\d+\.\d+\.\d+\.\d+)+ -\> (\d+\.\d+\.\d+\.\d+)+/) {
86 &checkem
($1, $2, $type);
92 if (seek(ALERT2
,0,1)){
95 if ($_=~/.*sshd.*Failed password for root from.*/) {
96 my @array=split(/ /,$_);&checkssh
($array[10], "possible SSH-Bruteforce Attack");}
100 # Run this stuff every 30 seconds..
101 if ($counter == 30) {
102 &remove_blocks
; # This might get moved elsewhere, depending on how much load
103 # it puts on the system..
112 my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size,
113 $atime,$mtime,$ctime,$blksize,$blocks) = stat($alert_file);
114 if ($size < $previous_size) { # The filesize is smaller than last
115 close (ALERT
); # we checked, so we need to reopen it
116 open (ALERT
, "$alert_file"); # This should still work in our main while
117 $previous_size=$size; # loop (I hope)
118 write_log
("Log filename changed. Reopening $alert_file\n");
120 $previous_size=$size;
126 my ($source, $dest,$type) = @_;
129 return 1 if ($source eq $hostipaddr);
130 # this should prevent is from nuking ourselves
132 return 1 if ($source eq $gatewayaddr); # or our gateway
133 if ($ignore{$source} == 1) { # check our ignore list..
134 &write_log
("$source\t$type\n");
135 &write_log
("Ignoring attack because $source is in my ignore list\n");
139 # if the offending packet was sent to us, the network, or the broadcast, then
140 if ($targethash{$dest} == 1) {
141 &ipchain
($source, $dest, $type);
143 # you will see this if the destination was not in the $targethash, and the
144 # packet was not ignored before the target check..
146 &write_log
("Odd.. source = $source, dest = $dest - No action done.\n");
147 if (defined ($opt_d)) {
148 foreach $key (keys %targethash) {
149 &write_log
("targethash{$key} = $targethash{$key}\n");
156 my ($source,$type) = @_;
159 return 1 if ($source eq $hostipaddr);
160 # this should prevent is from nuking ourselves
162 return 1 if ($source eq $gatewayaddr); # or our gateway
164 if ($sshhash{$dest} eq "" ){
167 if ($sshhash{$dest} >= 3 ) {
168 &write_log
("source = $source, count $sshhash{$dest} - blocking for ssh attack.\n");
169 &ipchain
($source, "", $type);
171 # you will see this if the destination was not in the $sshhash, and the
172 # packet was not ignored before the target check..
174 &write_log
("Odd.. source = $source, ssh count only $sshhash{$dest} - No action done.\n");
175 if (defined ($opt_d)) {
176 foreach $key (keys %sshhash) {
177 &write_log
("sshhash{$key} = %sshhash{$key}\n");
180 $sshhash{$key} = $sshhash{$key}+1;
185 my ($source, $dest, $type) = @_;
186 &write_log
("$source\t$type\n");
187 if ($hash{$source} eq "") {
188 &write_log
("Running '$blockpath $source'\n");
189 system ("$blockpath $source");
190 $hash{$source} = time() + $TimeLimit;
192 # We have already blocked this one, but snort detected another attack. So
193 # we should update the time blocked..
194 $hash{$source} = time() + $TimeLimit;
198 sub build_ignore_hash
{
199 # This would cause is to ignore all broadcasts if it
200 # got set.. However if unset, then the attacker could spoof the packet to make
201 # it look like it came from the network, and a reply to the spoofed packet
202 # could be seen if the attacker were on the local network.
203 # $ignore{$networkaddr}=1;
205 # same thing as above, just with the broadcast instead of the network.
206 # $ignore{$broadcastaddr}=1;
208 $ignore{$gatewayaddr}=1;
209 $ignore{$hostipaddr}=1;
210 if ($ignorefile ne "") {
211 open (IGNORE
, $ignorefile);
214 next if (/\#/); #skip comments
215 next if (/^\s*$/); # and blank lines
220 print "Loaded $count addresses from $ignorefile\n";
222 print "No ignore file was loaded!\n";
228 $opt_c = "/etc/guardian.conf";
232 die "Need a configuration file.. please use to the -c option to name a configuration file\n";
235 open (CONF
, $opt_c) or die "Cannot read the config file $opt_c, $!\n";
238 next if (/^\s*$/); #skip blank lines
239 next if (/^#/); # skip comment lines
240 if (/LogFile\s+(.*)/) {
243 if (/Interface\s+(.*)/) {
246 if (/AlertFile\s+(.*)/) {
249 if (/IgnoreFile\s+(.*)/) {
252 if (/TargetFile\s+(.*)/) {
255 if (/TimeLimit\s+(.*)/) {
258 if (/HostIpAddr\s+(.*)/) {
261 if (/HostGatewayByte\s+(.*)/) {
262 $hostgatewaybyte = $1;
266 if ($interface eq "") {
267 die "Fatal! Interface is undefined.. Please define it in $opt_o with keyword Interface\n";
269 if ($alert_file eq "") {
270 print "Warning! AlertFile is undefined.. Assuming /var/log/snort.alert\n";
271 $alert_file="/var/log/snort.alert";
273 if ($hostipaddr eq "") {
274 print "Warning! HostIpAddr is undefined! Attempting to guess..\n";
275 $hostipaddr = &get_ip
($interface);
276 print "Got it.. your HostIpAddr is $hostipaddr\n";
278 if ($ignorefile eq "") {
279 print "Warning! IgnoreFile is undefined.. going with default ignore list (hostname and gateway)!\n";
281 if ($hostgatewaybyte eq "") {
282 print "Warning! HostGatewayByte is undefined.. gateway will not be in ignore list!\n";
284 if ($logfile eq "") {
285 print "Warning! LogFile is undefined.. Assuming debug mode, output to STDOUT\n";
289 print "Warning! Logfile is not writeable! Engaging debug mode, output to STDOUT\n";
293 foreach $mypath (split (/:/, $ENV{PATH
})) {
294 if (-x
"$mypath/guardian_block.sh") {
295 $blockpath = "$mypath/guardian_block.sh";
297 if (-x
"$mypath/guardian_unblock.sh") {
298 $unblockpath = "$mypath/guardian_unblock.sh";
302 if ($blockpath eq "") {
303 print "Error! Could not find guardian_block.sh. Please consult the README. \n";
306 if ($unblockpath eq "") {
307 print "Warning! Could not find guardian_unblock.sh. Guardian will not be\n";
308 print "able to remove blocked ip addresses. Please consult the README file\n";
310 if ($TimeLimit eq "") {
311 print "Warning! Time limit not defined. Defaulting to absurdly long time limit\n";
312 $TimeLimit = 999999999;
318 my $date = localtime();
319 if (defined($opt_d)) { # we are in debug mode, and not daemonized
320 print STDOUT
$message;
322 open (LOG
, ">>$logfile");
323 print LOG
$date.": ".$message;
335 &write_log
("Guardian process id $$\n");
336 $home = (getpwuid($>))[7] || die "No home directory!\n";
337 chdir($home); # go to my homedir
338 setpgrp(0,0); # become process leader
342 print "Testing...\n";
347 my ($interface) = $_[0];
349 open (IFCONFIG
, "/bin/netstat -iee |grep $interface -A7 |");
351 if ($OS eq "FreeBSD") {
352 if (/inet (\d+\.\d+\.\d+\.\d+)/) {
356 if ($OS eq "Linux") {
357 if (/inet addr:(\d+\.\d+\.\d+\.\d+)/) {
364 if ($ip eq "") { die "Couldn't figure out the ip address\n"; }
368 sub sig_handler_setup
{
369 $SIG{TERM
} = \
&clean_up_and_exit
; # kill
370 $SIG{QUIT
} = \
&clean_up_and_exit
; # kill -3
371 # $SIG{HUP} = \&flush_and_reload; # kill -1
377 foreach $source (keys %hash) {
378 if ($hash{$source} < $time) {
379 &call_unblock
($source, "expiring block of $source\n");
380 delete ($hash{$source});
386 my ($source, $message) = @_;
387 &write_log
("$message");
388 system ("$unblockpath $source");
391 sub clean_up_and_exit
{
393 &write_log
("received kill sig.. shutting down\n");
394 foreach $source (keys %hash) {
395 &call_unblock
($source, "removing $source for shutdown\n");
400 sub load_targetfile
{
402 open (TARG
, "$targetfile") or die "Cannot open $targetfile\n";
405 next if (/\#/); #skip comments
406 next if (/^\s*$/); # and blank lines
411 print "Loaded $count addresses from $targetfile\n";