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Commit | Line | Data |
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7c4cc0d8 | 1 | #!/usr/bin/perl |
6579aab2 | 2 | # based on V 1.7 guardian enhanced for IPFire and snort 2.8 |
7c4cc0d8 CS |
3 | # Read the readme file for changes |
4 | # | |
fb30e20c CS |
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 | |
7c4cc0d8 CS |
9 | |
10 | $OS=`uname`; | |
11 | chomp $OS; | |
12 | print "OS shows $OS\n"; | |
13 | ||
14 | require 'getopts.pl'; | |
15 | ||
16 | &Getopts ('hc:d'); | |
17 | if (defined($opt_h)) { | |
6579aab2 CS |
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"; | |
23 | exit; | |
7c4cc0d8 CS |
24 | } |
25 | &load_conf; | |
26 | &sig_handler_setup; | |
27 | ||
28 | print "My ip address and interface are: $hostipaddr $interface\n"; | |
29 | ||
30 | if ($hostipaddr !~ /\d+\.\d+\.\d+\.\d+/) { | |
6579aab2 CS |
31 | print "This ip address is bad : $hostipaddr\n"; |
32 | die "I need a good host ipaddress\n"; | |
7c4cc0d8 CS |
33 | } |
34 | ||
35 | $networkaddr = $hostipaddr; | |
36 | $networkaddr =~ s/\d+$/0/; | |
841f013e | 37 | $gatewayaddr = `cat /var/ipfire/red/remote-ipaddress 2>/dev/null`; |
7c4cc0d8 CS |
38 | $broadcastaddr = $hostipaddr; |
39 | $broadcastaddr =~ s/\d+$/255/; | |
40 | &build_ignore_hash; | |
41 | ||
841f013e CS |
42 | print "My gatewayaddess is: $gatewayaddr\n"; |
43 | ||
7c4cc0d8 CS |
44 | # This is the target hash. If a packet was destened to any of these, then the |
45 | # sender of that packet will get denied, unless it is on the ignore list.. | |
46 | ||
6579aab2 CS |
47 | %targethash = ( "$networkaddr" => 1, |
48 | "$broadcastaddr" => 1, | |
49 | "0" => 1, # This is what gets sent to &checkem if no | |
50 | # destination was found. | |
51 | "$hostipaddr" => 1); | |
7c4cc0d8 | 52 | |
057249ba CS |
53 | &get_aliases; |
54 | ||
fb30e20c CS |
55 | %sshhash = (); |
56 | ||
7c4cc0d8 | 57 | if ( -e $targetfile ) { |
6579aab2 | 58 | &load_targetfile; |
7c4cc0d8 CS |
59 | } |
60 | ||
61 | if (!defined($opt_d)) { | |
6579aab2 CS |
62 | print "Becoming a daemon..\n"; |
63 | &daemonize; | |
7c4cc0d8 CS |
64 | } else { print "Running in debug mode..\n"; } |
65 | ||
66 | open (ALERT, $alert_file) or die "can't open alert file: $alert_file: $!\n"; | |
6579aab2 | 67 | seek (ALERT, 0, 2); # set the position to EOF. |
7c4cc0d8 CS |
68 | # this is the same as a tail -f :) |
69 | $counter=0; | |
fb30e20c | 70 | open (ALERT2, "/var/log/messages" ) or die "can't open /var/log/messages: $!\n"; |
6579aab2 | 71 | seek (ALERT2, 0, 2); # set the position to EOF. |
fb30e20c | 72 | # this is the same as a tail -f :) |
fb30e20c | 73 | |
6579aab2 CS |
74 | for (;;) { |
75 | sleep 1; | |
76 | if (seek(ALERT,0,1)){ | |
77 | while (<ALERT>) { | |
78 | chop; | |
79 | if (defined($opt_d)) { | |
80 | print "$_\n"; | |
81 | } | |
82 | if (/\[\*\*\]\s+(.*)\s+\[\*\*\]/){ | |
83 | $type=$1; | |
84 | } | |
85 | if (/(\d+\.\d+\.\d+\.\d+):\d+ -\> (\d+\.\d+\.\d+\.\d+):\d+/) { | |
86 | &checkem ($1, $2, $type); | |
87 | } | |
88 | if (/(\d+\.\d+\.\d+\.\d+)+ -\> (\d+\.\d+\.\d+\.\d+)+/) { | |
89 | &checkem ($1, $2, $type); | |
90 | } | |
91 | } | |
92 | } | |
93 | ||
94 | sleep 1; | |
95 | if (seek(ALERT2,0,1)){ | |
96 | while (<ALERT2>) { | |
97 | chop; | |
98 | if ($_=~/.*sshd.*Failed password for root from.*/) { | |
a3db3cc9 | 99 | my @array=split(/ /,$_);&checkssh ($array[11], "possible SSH-Bruteforce Attack");} |
6579aab2 CS |
100 | } |
101 | } | |
102 | ||
103 | # Run this stuff every 30 seconds.. | |
104 | if ($counter == 30) { | |
105 | &remove_blocks; # This might get moved elsewhere, depending on how much load | |
106 | # it puts on the system.. | |
107 | &check_log_name; | |
108 | $counter=0; | |
109 | } else { | |
110 | $counter=$counter+1; | |
111 | } | |
7c4cc0d8 CS |
112 | } |
113 | ||
114 | sub check_log_name { | |
6579aab2 CS |
115 | my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size, |
116 | $atime,$mtime,$ctime,$blksize,$blocks) = stat($alert_file); | |
117 | if ($size < $previous_size) { # The filesize is smaller than last | |
118 | close (ALERT); # we checked, so we need to reopen it | |
119 | open (ALERT, "$alert_file"); # This should still work in our main while | |
120 | $previous_size=$size; # loop (I hope) | |
121 | write_log ("Log filename changed. Reopening $alert_file\n"); | |
122 | } else { | |
123 | $previous_size=$size; | |
124 | } | |
7c4cc0d8 | 125 | } |
6579aab2 | 126 | |
7c4cc0d8 CS |
127 | |
128 | sub checkem { | |
6579aab2 CS |
129 | my ($source, $dest,$type) = @_; |
130 | my $flag=0; | |
131 | ||
132 | return 1 if ($source eq $hostipaddr); | |
133 | # this should prevent is from nuking ourselves | |
134 | ||
135 | return 1 if ($source eq $gatewayaddr); # or our gateway | |
136 | if ($ignore{$source} == 1) { # check our ignore list.. | |
137 | &write_log("$source\t$type\n"); | |
138 | &write_log("Ignoring attack because $source is in my ignore list\n"); | |
139 | return 1; | |
140 | } | |
141 | ||
142 | # if the offending packet was sent to us, the network, or the broadcast, then | |
143 | if ($targethash{$dest} == 1) { | |
144 | &ipchain ($source, $dest, $type); | |
145 | } | |
146 | # you will see this if the destination was not in the $targethash, and the | |
147 | # packet was not ignored before the target check.. | |
148 | else { | |
149 | &write_log ("Odd.. source = $source, dest = $dest - No action done.\n"); | |
150 | if (defined ($opt_d)) { | |
151 | foreach $key (keys %targethash) { | |
152 | &write_log ("targethash{$key} = $targethash{$key}\n"); | |
153 | } | |
154 | } | |
155 | } | |
7c4cc0d8 CS |
156 | } |
157 | ||
fb30e20c | 158 | sub checkssh { |
6579aab2 CS |
159 | my ($source,$type) = @_; |
160 | my $flag=0; | |
161 | ||
162 | return 1 if ($source eq $hostipaddr); | |
163 | # this should prevent is from nuking ourselves | |
164 | ||
165 | return 1 if ($source eq $gatewayaddr); # or our gateway | |
166 | ||
167 | if ($sshhash{$dest} eq "" ){ | |
168 | $sshhash{$dest} = 1; | |
169 | } | |
170 | if ($sshhash{$dest} >= 3 ) { | |
171 | &write_log ("source = $source, count $sshhash{$dest} - blocking for ssh attack.\n"); | |
172 | &ipchain ($source, "", $type); | |
173 | } | |
174 | # you will see this if the destination was not in the $sshhash, and the | |
175 | # packet was not ignored before the target check.. | |
176 | else { | |
177 | &write_log ("Odd.. source = $source, ssh count only $sshhash{$dest} - No action done.\n"); | |
178 | if (defined ($opt_d)) { | |
179 | foreach $key (keys %sshhash) { | |
180 | &write_log ("sshhash{$key} = %sshhash{$key}\n"); | |
181 | } | |
182 | } | |
183 | $sshhash{$key} = $sshhash{$key}+1; | |
184 | } | |
fb30e20c CS |
185 | } |
186 | ||
6579aab2 CS |
187 | sub ipchain { |
188 | my ($source, $dest, $type) = @_; | |
189 | &write_log ("$source\t$type\n"); | |
190 | if ($hash{$source} eq "") { | |
057249ba CS |
191 | &write_log ("Running '$blockpath $source $interface'\n"); |
192 | system ("$blockpath $source $interface"); | |
6579aab2 CS |
193 | $hash{$source} = time() + $TimeLimit; |
194 | } else { | |
195 | # We have already blocked this one, but snort detected another attack. So | |
196 | # we should update the time blocked.. | |
197 | $hash{$source} = time() + $TimeLimit; | |
198 | } | |
7c4cc0d8 | 199 | } |
6579aab2 | 200 | |
7c4cc0d8 CS |
201 | sub build_ignore_hash { |
202 | # This would cause is to ignore all broadcasts if it | |
203 | # got set.. However if unset, then the attacker could spoof the packet to make | |
204 | # it look like it came from the network, and a reply to the spoofed packet | |
6579aab2 CS |
205 | # could be seen if the attacker were on the local network. |
206 | # $ignore{$networkaddr}=1; | |
7c4cc0d8 CS |
207 | |
208 | # same thing as above, just with the broadcast instead of the network. | |
209 | # $ignore{$broadcastaddr}=1; | |
6579aab2 CS |
210 | my $count =0; |
211 | $ignore{$gatewayaddr}=1; | |
212 | $ignore{$hostipaddr}=1; | |
213 | if ($ignorefile ne "") { | |
214 | open (IGNORE, $ignorefile); | |
215 | while (<IGNORE>) { | |
fd4da55b CS |
216 | $_=~ s/\s+$//; |
217 | chomp; | |
6579aab2 CS |
218 | next if (/\#/); #skip comments |
219 | next if (/^\s*$/); # and blank lines | |
220 | $ignore{$_}=1; | |
221 | $count++; | |
222 | } | |
223 | close (IGNORE); | |
224 | print "Loaded $count addresses from $ignorefile\n"; | |
225 | } else { | |
226 | print "No ignore file was loaded!\n"; | |
227 | } | |
7c4cc0d8 CS |
228 | } |
229 | ||
230 | sub load_conf { | |
6579aab2 CS |
231 | if ($opt_c eq "") { |
232 | $opt_c = "/etc/guardian.conf"; | |
233 | } | |
234 | ||
235 | if (! -e $opt_c) { | |
236 | die "Need a configuration file.. please use to the -c option to name a configuration file\n"; | |
237 | } | |
238 | ||
239 | open (CONF, $opt_c) or die "Cannot read the config file $opt_c, $!\n"; | |
240 | while (<CONF>) { | |
241 | chop; | |
242 | next if (/^\s*$/); #skip blank lines | |
243 | next if (/^#/); # skip comment lines | |
244 | if (/LogFile\s+(.*)/) { | |
245 | $logfile = $1; | |
246 | } | |
247 | if (/Interface\s+(.*)/) { | |
248 | $interface = $1; | |
057249ba CS |
249 | if ( $interface eq "" ) { |
250 | $interface = `cat /var/ipfire/ethernet/settings | grep RED_DEV | cut -d"=" -f2`; | |
251 | } | |
6579aab2 CS |
252 | } |
253 | if (/AlertFile\s+(.*)/) { | |
254 | $alert_file = $1; | |
255 | } | |
256 | if (/IgnoreFile\s+(.*)/) { | |
257 | $ignorefile = $1; | |
258 | } | |
259 | if (/TargetFile\s+(.*)/) { | |
260 | $targetfile = $1; | |
261 | } | |
262 | if (/TimeLimit\s+(.*)/) { | |
263 | $TimeLimit = $1; | |
264 | } | |
265 | if (/HostIpAddr\s+(.*)/) { | |
266 | $hostipaddr = $1; | |
267 | } | |
268 | if (/HostGatewayByte\s+(.*)/) { | |
269 | $hostgatewaybyte = $1; | |
270 | } | |
271 | } | |
272 | ||
6579aab2 CS |
273 | if ($alert_file eq "") { |
274 | print "Warning! AlertFile is undefined.. Assuming /var/log/snort.alert\n"; | |
275 | $alert_file="/var/log/snort.alert"; | |
276 | } | |
277 | if ($hostipaddr eq "") { | |
278 | print "Warning! HostIpAddr is undefined! Attempting to guess..\n"; | |
057249ba | 279 | $hostipaddr = `cat /var/ipfire/red/local-ipaddress`; |
6579aab2 CS |
280 | print "Got it.. your HostIpAddr is $hostipaddr\n"; |
281 | } | |
282 | if ($ignorefile eq "") { | |
283 | print "Warning! IgnoreFile is undefined.. going with default ignore list (hostname and gateway)!\n"; | |
284 | } | |
285 | if ($hostgatewaybyte eq "") { | |
286 | print "Warning! HostGatewayByte is undefined.. gateway will not be in ignore list!\n"; | |
287 | } | |
288 | if ($logfile eq "") { | |
289 | print "Warning! LogFile is undefined.. Assuming debug mode, output to STDOUT\n"; | |
290 | $opt_d = 1; | |
291 | } | |
292 | if (! -w $logfile) { | |
293 | print "Warning! Logfile is not writeable! Engaging debug mode, output to STDOUT\n"; | |
294 | $opt_d = 1; | |
295 | } | |
296 | ||
297 | foreach $mypath (split (/:/, $ENV{PATH})) { | |
298 | if (-x "$mypath/guardian_block.sh") { | |
299 | $blockpath = "$mypath/guardian_block.sh"; | |
300 | } | |
301 | if (-x "$mypath/guardian_unblock.sh") { | |
302 | $unblockpath = "$mypath/guardian_unblock.sh"; | |
303 | } | |
304 | } | |
305 | ||
306 | if ($blockpath eq "") { | |
307 | print "Error! Could not find guardian_block.sh. Please consult the README. \n"; | |
308 | exit; | |
309 | } | |
310 | if ($unblockpath eq "") { | |
311 | print "Warning! Could not find guardian_unblock.sh. Guardian will not be\n"; | |
312 | print "able to remove blocked ip addresses. Please consult the README file\n"; | |
313 | } | |
314 | if ($TimeLimit eq "") { | |
315 | print "Warning! Time limit not defined. Defaulting to absurdly long time limit\n"; | |
316 | $TimeLimit = 999999999; | |
317 | } | |
7c4cc0d8 CS |
318 | } |
319 | ||
7c4cc0d8 | 320 | sub write_log { |
6579aab2 CS |
321 | my $message = $_[0]; |
322 | my $date = localtime(); | |
323 | if (defined($opt_d)) { # we are in debug mode, and not daemonized | |
324 | print STDOUT $message; | |
325 | } else { | |
326 | open (LOG, ">>$logfile"); | |
327 | print LOG $date.": ".$message; | |
328 | close (LOG); | |
329 | } | |
7c4cc0d8 CS |
330 | } |
331 | ||
7c4cc0d8 | 332 | sub daemonize { |
6579aab2 CS |
333 | my ($home); |
334 | if (fork()) { | |
335 | # parent | |
336 | exit(0); | |
337 | } else { | |
338 | # child | |
339 | &write_log ("Guardian process id $$\n"); | |
340 | $home = (getpwuid($>))[7] || die "No home directory!\n"; | |
341 | chdir($home); # go to my homedir | |
342 | setpgrp(0,0); # become process leader | |
343 | close(STDOUT); | |
344 | close(STDIN); | |
345 | close(STDERR); | |
346 | print "Testing...\n"; | |
347 | } | |
348 | } | |
7c4cc0d8 | 349 | |
7c4cc0d8 | 350 | sub sig_handler_setup { |
057249ba CS |
351 | $SIG{INT} = \&clean_up_and_exit; # kill -2 |
352 | $SIG{TERM} = \&clean_up_and_exit; # kill -9 | |
6579aab2 | 353 | $SIG{QUIT} = \&clean_up_and_exit; # kill -3 |
7c4cc0d8 CS |
354 | # $SIG{HUP} = \&flush_and_reload; # kill -1 |
355 | } | |
356 | ||
357 | sub remove_blocks { | |
6579aab2 CS |
358 | my $source; |
359 | my $time = time(); | |
360 | foreach $source (keys %hash) { | |
361 | if ($hash{$source} < $time) { | |
362 | &call_unblock ($source, "expiring block of $source\n"); | |
363 | delete ($hash{$source}); | |
364 | } | |
365 | } | |
7c4cc0d8 CS |
366 | } |
367 | ||
368 | sub call_unblock { | |
6579aab2 CS |
369 | my ($source, $message) = @_; |
370 | &write_log ("$message"); | |
057249ba | 371 | system ("$unblockpath $source $interface"); |
7c4cc0d8 CS |
372 | } |
373 | ||
374 | sub clean_up_and_exit { | |
6579aab2 CS |
375 | my $source; |
376 | &write_log ("received kill sig.. shutting down\n"); | |
377 | foreach $source (keys %hash) { | |
378 | &call_unblock ($source, "removing $source for shutdown\n"); | |
379 | } | |
380 | exit; | |
7c4cc0d8 CS |
381 | } |
382 | ||
383 | sub load_targetfile { | |
6579aab2 CS |
384 | my $count = 0; |
385 | open (TARG, "$targetfile") or die "Cannot open $targetfile\n"; | |
386 | while (<TARG>) { | |
387 | chop; | |
388 | next if (/\#/); #skip comments | |
389 | next if (/^\s*$/); # and blank lines | |
390 | $targethash{$_}=1; | |
391 | $count++; | |
392 | } | |
393 | close (TARG); | |
394 | print "Loaded $count addresses from $targetfile\n"; | |
7c4cc0d8 | 395 | } |
057249ba CS |
396 | |
397 | sub get_aliases { | |
398 | my $ip; | |
399 | print "Scanning for aliases on $interface and add them to the target hash..."; | |
400 | ||
401 | open (IFCONFIG, "/sbin/ip addr show $interface |"); | |
402 | my @lines = <IFCONFIG>; | |
403 | close(IFCONFIG); | |
404 | ||
405 | foreach $line (@lines) { | |
406 | if ( $line =~ /inet (\d+\.\d+\.\d+\.\d+)/) { | |
407 | $ip = $1; | |
408 | print " got $ip on $interface ... "; | |
409 | $targethash{'$ip'} = "1"; | |
410 | } | |
411 | } | |
412 | ||
413 | print "done \n"; | |
414 | } |