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df6ec59f SS |
1 | package Guardian::Events; |
2 | use strict; | |
3 | use warnings; | |
4 | ||
5 | use Exporter qw(import); | |
6 | ||
7c8f0696 | 7 | our @EXPORT_OK = qw(Init CheckAction GenerateIgnoreList Update); |
df6ec59f SS |
8 | |
9 | # Hash which stores all supported commands from the queue. | |
10 | my %commands = ( | |
11 | 'count' => \&Counter, | |
12 | 'block' => \&CallBlock, | |
13 | 'unblock' => \&CallUnblock, | |
14 | 'flush' => \&CallFlush, | |
7121d8cd | 15 | 'reload' => \&main::Reload, |
ab7c10eb | 16 | 'reload-ignore-list' => \&main::ReloadIgnoreList, |
df6ec59f SS |
17 | ); |
18 | ||
19 | # Hash to store addresses and their current count. | |
20 | my %counthash = (); | |
21 | ||
22 | # Hash to store all currentyl blocked addresses and a timestamp | |
23 | # when the block for this address can be released. | |
24 | my %blockhash = (); | |
25 | ||
66e1ad0a | 26 | # Hash to store user-defined IP addresses and/or subnets which should be |
0d218038 | 27 | # ignored in case any events should be repored for them. |
66e1ad0a SS |
28 | my %ignorehash = (); |
29 | ||
0d218038 SS |
30 | # Array to store localhost related IP addresses. |
31 | # They are always white-listed to prevent guardian from blocking | |
32 | # any local traffic. | |
33 | my @localhost_addresses = ("127.0.0.1", "::1"); | |
34 | ||
df6ec59f SS |
35 | # This object will contain the reference to the logger object after calling Init. |
36 | my $logger; | |
37 | ||
38 | # | |
39 | ## The "Init" (Block) function. | |
40 | # | |
41 | ## This function is responsible to initialize Block as a class based object. | |
42 | ## It has to be called once before any blocking event can be processed. | |
43 | # | |
44 | ## The following arguments must be passed, during initialization: | |
45 | ## "BlockCount" and "BlockTime" which both have to be natural numbers. | |
46 | # | |
47 | sub Init (%) { | |
48 | my ( $class, %args ) = @_; | |
49 | my $self = \%args; | |
50 | ||
51 | # Fail, if some critical arguments are missing. | |
52 | unless ((exists($self->{BlockCount})) && (exists($self->{BlockTime}))) { | |
53 | die "Could not initialize Block: Too less arguments are given.\n"; | |
54 | } | |
55 | ||
56 | # Use bless to make "$self" to an object of class "$class". | |
57 | bless($self, $class); | |
58 | ||
59 | # Assign logger object. | |
60 | $logger = $self->{Logger}; | |
61 | ||
62 | # Log used firewall engine. | |
63 | $logger->Log("debug", "Using firewall engine: $self->{FirewallEngine}"); | |
64 | ||
65 | # Try to load the specified firewall engine or die. | |
66 | my $module_name = "Guardian::" . $self->{FirewallEngine}; | |
67 | eval "use $module_name; 1" or die "Could not load a module for firewall engine: $self->{FirewallEngine}!"; | |
68 | ||
66e1ad0a SS |
69 | # Check if an IgnoreFile has been configured. |
70 | if (exists($self->{IgnoreFile})) { | |
71 | # Call function to handle the ignore mechanism. | |
72 | &GenerateIgnoreList($self->{IgnoreFile}); | |
0d218038 SS |
73 | } else { |
74 | # Whitelist local addresses. | |
75 | %ignorehash = &_whitelist_localhost(); | |
66e1ad0a SS |
76 | } |
77 | ||
df6ec59f SS |
78 | # Return the class object. |
79 | return $self; | |
80 | } | |
81 | ||
82 | # | |
83 | ## The main "CheckAction" function. | |
84 | # | |
85 | ## This function is used to handle each recived event from the main event queue of guardian. | |
86 | # | |
87 | ## It will check if the given command is valid and will pass it to the responsible function. | |
88 | # | |
89 | sub CheckAction ($$) { | |
90 | my $self = shift; | |
91 | my @event = split(/ /, $_[0], 4); | |
92 | my ($command, $address, $module, $message) = @event; | |
93 | ||
94 | # Check if we got an invalid command. | |
95 | unless(exists($commands{$command})) { | |
96 | $logger->Log("err", "The CheckAction function has been called with an unsupported command ($command)!"); | |
97 | return; | |
98 | } | |
99 | ||
e1ff25ce SS |
100 | # Check if the given event contains an address. |
101 | if ($address) { | |
102 | # Convert and validate the given address. | |
103 | my $bin_address = &Guardian::Base::IPOrNet2Int($address); | |
104 | ||
105 | # Abort if the given address could not be converted because it is not valid. | |
106 | unless ($bin_address) { | |
107 | $logger->Log("err", "Invalid IP address: $address"); | |
108 | return; | |
109 | } | |
110 | ||
111 | # Check if address should be ignored. | |
112 | if(&_IsOnIgnoreList($bin_address)) { | |
113 | # Log message. | |
114 | $logger->Log("info", "Ignoring event for $address, because it is part of the ignore list."); | |
115 | return; | |
116 | } | |
66e1ad0a SS |
117 | } |
118 | ||
df6ec59f SS |
119 | # Call required handler. |
120 | my $error = $commands{$command}->($self, $address, $module, $message); | |
121 | ||
122 | # If we got any return code, something went wrong and should be logged. | |
123 | if ($error) { | |
124 | $logger->Log("err", "Got error: $error"); | |
125 | return; | |
126 | } | |
127 | } | |
128 | ||
129 | # | |
130 | ## The main "Counter" function. | |
131 | # | |
132 | ## This function is used to handle each count message + address, which has been sent by the main event | |
133 | ## loop of guardian. | |
134 | # | |
135 | ## It stores the address and the current count into the counthash and increase the count each time when | |
136 | ## the same address should be counted again. When the current count reaches the configured BlockCount, | |
137 | ## the responsible function will be called to block the address. | |
138 | # | |
139 | sub Counter ($@) { | |
140 | my $self = shift; | |
141 | my ($address, $module, $message) = @_; | |
142 | ||
143 | # Log event. | |
144 | $logger->Log("debug", "$module reported $message for address: $address"); | |
145 | ||
146 | # Increase existing count or start counting for new source addresses. | |
147 | if (exists($counthash{$address})) { | |
148 | # Skip already blocked addresses. | |
149 | if (exists($blockhash{$address})) { | |
150 | return undef; | |
151 | } | |
152 | ||
153 | # Increase count of the existing entry. | |
154 | $counthash{$address} = $counthash{$address} + 1; | |
155 | ||
156 | # Log altered count of the address. | |
157 | $logger->Log("debug", "Source $address now has count $counthash{$address}/$self->{BlockCount}..."); | |
158 | } else { | |
159 | # Log that counting for the address has been started. | |
160 | $logger->Log("debug", "Start counting for $address..."); | |
161 | ||
162 | # Set count to "1". | |
163 | $counthash{$address} = 1; | |
164 | } | |
165 | ||
166 | # Check if the address has reached the configured count limit. | |
167 | if ($counthash{$address} >= $self->{BlockCount}) { | |
168 | # Write out log message. | |
169 | $logger->Log("info", "Blocking $address for $self->{BlockTime} seconds..."); | |
170 | ||
171 | # Call block subroutine to block the address. | |
172 | my $error = &CallBlock($self, $address, $module, $message); | |
173 | ||
174 | # Return the message if an error occurs. | |
175 | return $error; | |
176 | } | |
177 | ||
178 | # Everything worked well, return nothing. | |
179 | return undef; | |
180 | } | |
181 | ||
182 | # | |
183 | ## The RemoveBlocks function. | |
184 | # | |
185 | ## This function periodly will be called and is responsible for releasing the block if the Blocktime | |
186 | ## on an address has expired. | |
187 | # | |
188 | ## To do this, the code will loop through all entries of the blockhash and check | |
189 | ## if the estimiated BlockTime of each address has reached and so the block can be released. | |
190 | # | |
191 | sub RemoveBlocks () { | |
192 | my $self = shift; | |
193 | ||
194 | # Get the current time. | |
195 | my $time = time(); | |
196 | ||
197 | # Loop through the blockhash. | |
198 | foreach my $address (keys %blockhash) { | |
199 | # Check if the blocktime for the address has expired. | |
200 | if ($blockhash{$address} <= $time) { | |
201 | # Call unblock subroutine. | |
202 | my $error = &CallUnblock($self, $address, "BlockTime", "has expired for $address"); | |
203 | ||
204 | # Log error messages if returned. | |
205 | if ($error) { | |
206 | $logger->Log("err", "$error"); | |
207 | } | |
208 | } | |
209 | } | |
210 | ||
211 | # Everything okay, return nothing. | |
212 | return undef; | |
213 | } | |
214 | ||
215 | # | |
216 | ## The CallBlock function. | |
217 | # | |
218 | ## This function is called, if the BlockCount for an address is reached or a direct | |
219 | ## request for blocking an address has been recieved. | |
220 | # | |
221 | sub CallBlock ($@) { | |
222 | my $self = shift; | |
223 | my ($address, $module, $message) = @_; | |
224 | ||
225 | # Log the call for blocking an address. | |
226 | $logger->Log("info", "$module - $message"); | |
227 | ||
228 | # Check if an entry for this address exists | |
229 | # in the blockhash. If not, the address has | |
230 | # not been blocked yet, call the responisible | |
231 | # function to do this now. | |
232 | unless (exists($blockhash{$address})) { | |
e9c558fe SS |
233 | # Obtain the configured FirewallAction. |
234 | my $action = $self->{FirewallAction}; | |
df6ec59f SS |
235 | |
236 | # Block the given address. | |
237 | my $error = &DoBlock($address, $action); | |
238 | ||
239 | # If we got back an error message something went wrong. | |
240 | if ($error) { | |
f842727a SS |
241 | # Exit function and return the used FirewallEngine and the error message. |
242 | return "$self->{FirewallEngine} - $error"; | |
df6ec59f SS |
243 | } else { |
244 | # Address has been successfully blocked, print a log message. | |
245 | $logger->Log("debug", "Address $address successfully has been blocked..."); | |
246 | } | |
247 | } | |
248 | ||
249 | # Generate time when the block will expire. | |
250 | my $expire = time() + $self->{BlockTime}; | |
251 | ||
252 | # Store the blocked address and the expire time | |
253 | # in the blockhash. | |
254 | $blockhash{$address} = $expire; | |
255 | ||
256 | # Return nothing "undef" if everything is okay. | |
257 | return undef; | |
258 | } | |
259 | ||
260 | # | |
261 | ## CallUnblock function. | |
262 | # | |
263 | ## This function is responsible for unblocking and deleting a given | |
264 | ## address from the blockhash. | |
265 | # | |
266 | sub CallUnblock ($) { | |
267 | my $self = shift; | |
268 | my ($address, $module, $message) = @_; | |
269 | ||
270 | # Log the call for unblocking an address. | |
271 | $logger->Log("info", "$module - $message"); | |
272 | ||
273 | # Return an error if no entry for the given address | |
274 | # is present in the blockhash. | |
275 | unless (exists($blockhash{$address})) { | |
276 | return "Address $address was not blocked!"; | |
277 | } | |
278 | ||
279 | # Unblock the address. | |
280 | my $error = &DoUnblock($address); | |
281 | ||
282 | # If an error message is returned, something went wrong. | |
283 | if ($error) { | |
284 | # Exit function and return the error message. | |
285 | return $error; | |
286 | } else { | |
287 | # Address successfully has been unblocked. | |
288 | $logger->Log("debug", "Address $address successfully has been unblocked..."); | |
289 | } | |
290 | ||
291 | # Drop address from blockhash. | |
292 | delete ($blockhash{$address}); | |
293 | ||
294 | # Everything worked well, return nothing. | |
295 | return undef; | |
296 | } | |
297 | ||
66e1ad0a SS |
298 | # |
299 | ## GenerateIgnoreList function. | |
300 | # | |
301 | ## This function is responsible for generating/updating the | |
302 | ## IgnoreHash which contains all ignored IP addresses and | |
303 | ## networks. | |
304 | # | |
305 | sub GenerateIgnoreList($) { | |
306 | my $file = shift; | |
900cad7f SS |
307 | my @include_files; |
308 | ||
309 | # Reset current ignore hash and add | |
310 | # localhost related IP addresses. | |
311 | %ignorehash = &_whitelist_localhost(); | |
66e1ad0a SS |
312 | |
313 | # Check if the given IgnoreFile could be opened. | |
314 | unless(-e $file) { | |
315 | $logger->Log("err", "The configured IgnoreFile \($file\) could not be opened. Skipped!"); | |
316 | return; | |
317 | } | |
318 | ||
900cad7f | 319 | # Open the given IgnoreFile. |
66e1ad0a SS |
320 | open (IGNORE, $file); |
321 | ||
322 | # Read-in the file line by line. | |
323 | while (<IGNORE>) { | |
324 | # Skip comments. | |
325 | next if (/\#/); | |
326 | ||
327 | # Skip blank lines. | |
328 | next if (/^\s*$/); | |
329 | ||
330 | # Remove any newlines. | |
331 | chomp; | |
332 | ||
900cad7f SS |
333 | # Check for an include instruction. |
334 | if ($_ =~ /^Include_File = (.*)/) { | |
335 | my $include_file = $1; | |
66e1ad0a | 336 | |
900cad7f SS |
337 | # Check if the parsed include file exists and is read-able. |
338 | if (-e $include_file) { | |
339 | # Add file to the array of files wich will be included. | |
340 | push(@include_files, $include_file); | |
341 | ||
342 | # Write out log message. | |
343 | $logger->Log("debug", "Addresses from $include_file will be included..."); | |
344 | } else { | |
345 | # Log missing file. | |
346 | $logger->Log("err", "$include_file will not be included. File does not exist!"); | |
347 | } | |
348 | } else { | |
349 | # Check if the line contains a valid single address or network and | |
350 | # convert it into binary format. Store the result/start and | |
351 | # end values in a temporary array. | |
352 | my @values = &Guardian::Base::IPOrNet2Int($_); | |
353 | ||
354 | # If the function returned any values, the line contained a valid | |
355 | # single address or network which successfully has been converted into | |
356 | # binary format. | |
357 | if (@values) { | |
358 | # Assign the array as value to the ignorehash. | |
359 | $ignorehash{$_} = [@values]; | |
360 | } else { | |
361 | # Log invalid entry. | |
362 | $logger->Log("err", "IgnoreFile contains an invalid address/network: $_"); | |
363 | ||
364 | # Skip line. | |
365 | next; | |
366 | } | |
66e1ad0a SS |
367 | } |
368 | } | |
369 | ||
370 | # Close filehandle for the IgnoreFile. | |
371 | close (IGNORE); | |
5cd378cd | 372 | |
900cad7f SS |
373 | # Check if any files should be included. |
374 | if (@include_files) { | |
375 | # Loop through the array of files which should be included. | |
376 | foreach my $file (@include_files) { | |
377 | # Open the file. | |
378 | open(INCLUDE, $file); | |
379 | ||
380 | # Read-in file line by line. | |
381 | while(<INCLUDE>) { | |
382 | # Skip any comments. | |
383 | next if (/\#/); | |
384 | ||
385 | # Skip any blank lines. | |
386 | next if (/^\s*$/); | |
387 | ||
388 | # Chomp any newlines. | |
389 | chomp; | |
390 | ||
391 | # Check if the line contains a valid single address or network and | |
392 | # convert it into binary format. Store the result/start and | |
393 | # end values in a temporary array. | |
394 | my @values = &Guardian::Base::IPOrNet2Int($_); | |
395 | ||
396 | # If the function returned any values, the line contained a valid | |
397 | # single address or network which successfully has been converted into | |
398 | # binary format. | |
399 | if (@values) { | |
400 | # Assign the array as value to the ignorehash. | |
401 | $ignorehash{$_} = [@values]; | |
402 | } else { | |
403 | # Log invalid entry. | |
404 | $logger->Log("err", "$file contains an invalid address/network: $_"); | |
405 | ||
406 | # Skip line. | |
407 | next; | |
408 | } | |
409 | } | |
410 | ||
411 | # Close filehandle. | |
412 | close(INCLUDE); | |
413 | } | |
414 | } | |
415 | ||
5cd378cd SS |
416 | # Get amount of current elements in hash. |
417 | my $amount = scalar(keys(%ignorehash)); | |
418 | ||
419 | # Write out log message. | |
420 | $logger->Log("debug", "Ignore list currently contains $amount entries."); | |
66e1ad0a SS |
421 | } |
422 | ||
423 | # | |
424 | ## Private function to check if an address is part of the Ignore Hash. | |
425 | # | |
7c8f0696 SS |
426 | ## This function checks if a passed IP address in binary format (!), |
427 | ## directly or as part of an ignored network is stored in the ignore hash. | |
66e1ad0a SS |
428 | # |
429 | sub _IsOnIgnoreList ($) { | |
430 | my $bin_address = shift; | |
431 | ||
432 | # Loop through the ignore hash and grab the stored values. | |
433 | foreach my $key ( keys %ignorehash ) { | |
434 | # Dereference values array. | |
435 | my @values = @{$ignorehash{$key}}; | |
436 | ||
437 | # Obtain amount of items for the current value array. | |
438 | my $items = scalar @values; | |
439 | ||
440 | # Whether the amount equals one, the given binary address just | |
441 | # needs to be compared against a single address. | |
442 | if ($items eq "1") { | |
443 | my ($ignored_address) = @values; | |
444 | ||
445 | # Simple check if the stored and the given binary address | |
446 | # are the same. | |
447 | if ($bin_address eq $ignored_address) { | |
448 | # The given address is part of the ignore list. | |
449 | $logger->Log("debug", "Address $key found on the ignore list."); | |
450 | ||
451 | # Return "1" (True). | |
452 | return 1; | |
453 | } | |
454 | } | |
455 | ||
456 | # If the amount equals two, for passed binary address needs to | |
457 | # be checked if it is part of the ignored network range. | |
458 | elsif ($items eq "2") { | |
459 | my ($first_address, $last_address) = @values; | |
460 | ||
461 | # Check if the passed binary address is bigger than | |
462 | # the first address and smaler than the last address | |
463 | # (between) the stored network range. | |
464 | if (($bin_address >= $first_address) && ($bin_address <= $last_address)) { | |
465 | # The address is part of an ignored network. | |
466 | $logger->Log("debug", "Address is found inside the ignored network $key."); | |
467 | ||
468 | # Return "1" (True). | |
469 | return 1; | |
470 | } | |
471 | ||
472 | # If the amount is not eighter one or two, the current entry of the ignorehash seems | |
473 | # to be corrupted. Skip and log it. | |
474 | } else { | |
475 | # Write log message about this corruped item in the ignore hash. | |
476 | $logger->Log("err", "Invalid item in the Ignore Hash: $key - @values"); | |
477 | ||
478 | # Skip this element of the ignore hash. | |
479 | next; | |
480 | } | |
481 | } | |
482 | ||
483 | # If we got here, the given address is not part of the ignore hash. | |
484 | # Return nothing (False). | |
485 | return; | |
486 | } | |
487 | ||
0d218038 SS |
488 | # |
489 | ## The _whitelist_localhost function. | |
490 | # | |
491 | ## This tiny private function simple generates and returns a hash which contains | |
492 | ## the clear and binary converted addresses for all array-stored | |
493 | ## (@localhost_addresses) in an ignorelist compatible format. | |
494 | # | |
495 | sub _whitelist_localhost () { | |
496 | my %temphash; | |
497 | ||
498 | # Loop through the array of localhost related addresses. | |
499 | foreach my $address (@localhost_addresses) { | |
500 | # Validate and convert the addresss into binary format. | |
501 | my @values = &Guardian::Base::IPOrNet2Int($address); | |
502 | ||
503 | # Check if any values are returned. | |
504 | if (@values) { | |
505 | # Store the converted binary values in the temporary hash. | |
506 | $temphash{$address} = [@values]; | |
507 | } | |
508 | } | |
509 | ||
510 | # Return the temporary hash. | |
511 | return %temphash; | |
512 | } | |
513 | ||
df6ec59f | 514 | 1; |