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[people/stevee/guardian.git] / guardian
1 #!/usr/bin/perl
2 ###############################################################################
3 # #
4 # IPFire.org - A linux based firewall #
5 # Copyright (C) 2015 IPFire Development Team #
6 # #
7 # This program is free software: you can redistribute it and/or modify #
8 # it under the terms of the GNU General Public License as published by #
9 # the Free Software Foundation, either version 3 of the License, or #
10 # (at your option) any later version. #
11 # #
12 # This program is distributed in the hope that it will be useful, #
13 # but WITHOUT ANY WARRANTY; without even the implied warranty of #
14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
15 # GNU General Public License for more details. #
16 # #
17 # You should have received a copy of the GNU General Public License #
18 # along with this program. If not, see <http://www.gnu.org/licenses/>. #
19 # #
20 ###############################################################################
21
22 use strict;
23 use threads;
24 use threads::shared;
25 use Getopt::Long;
26 use Thread::Queue;
27 use Linux::Inotify2;
28 use Time::HiRes qw[ time sleep ];
29
30 require Guardian::Base;
31 require Guardian::Config;
32 require Guardian::Daemon;
33 require Guardian::Events;
34 require Guardian::Logger;
35 require Guardian::Parser;
36 require Guardian::Socket;
37
38 use warnings;
39
40 # Disable warnings of unjoinded threads when stopping guardian.
41 no warnings 'threads';
42
43 # Define version.
44 my $version ="2.0";
45
46 # Get and store the given command line arguments in a hash.
47 my %cmdargs = ();
48
49 &GetOptions (\%cmdargs,
50 'foreground|f',
51 'config|c=s',
52 'help|h',
53 'version|v',
54 );
55
56 # Show help / version information.
57 if (defined($cmdargs{"help"})) {
58 print "Guardian $version \n";
59 print "Usage: guardian <optional arguments>\n";
60 print " -c, --config\t\tspecifiy a configuration file other than the default (/etc/guardian/guardian.conf)\n";
61 print " -f, --foreground\trun in the foreground (doesn't fork, any output goes to STDOUT)\n";
62 print " -h, --help\t\tshows this help\n";
63 print " -v, --version\t\tdisplay programm version and exit.\n";
64 exit;
65 } elsif (defined($cmdargs{"version"})) {
66 print "Guardian $version \n";
67 exit;
68 }
69
70 # Check if another instance of guardian is allready running.
71 if (&Guardian::Daemon::IsRunning()) {
72 die "Another instance of Guardian is allready running...\n";
73 }
74
75 # Read-in the configuration file and store the settings.
76 # Push the may be given config file argument.
77 my %mainsettings = &Guardian::Config::UseConfig($cmdargs{"config"});
78
79 # Initialize Logger.
80 my $logger = Guardian::Logger->Init(%mainsettings);
81 $logger->Log("debug", "Logger successfully initialized...");
82
83 # Add the logger object to the mainsettings for passing
84 # it to the modules.
85 $mainsettings{Logger} = $logger;
86
87 # Redirect perls "die" messages to the logger before exiting.
88 $SIG{__DIE__} = sub { $logger->Log("err", "@_"); };
89
90 # Initialize the event handler.
91 my $events = Guardian::Events->Init(%mainsettings);
92
93 # Hash to store the currently monitored files and their configured
94 # parsers.
95 my %monitored_files = ();
96
97 # Shared hash between the main process and all threads. It will store the
98 # monitored files and their current file position.
99 my %file_positions :shared = ();
100
101 # Create the main queue. It is used to store and process all events which are
102 # reported and enqueued by the worker threads.
103 my $queue :shared = new Thread::Queue or die "Could not create new, empty queue. $!";;
104
105 # Array to store all currently running worker objects.
106 # (Does not include the socket thread)
107 my @running_workers;
108
109 # Check if guardian should be daemonized or keep in the foreground.
110 unless (defined($cmdargs{"foreground"})) {
111 # Fork into background.
112 &Guardian::Daemon::Daemonize();
113 } else {
114 # Write PID (process-id).
115 &Guardian::Daemon::WritePID();
116 }
117
118 # Call Init function to initzialize guardian.
119 &Init();
120
121 # Infinite main loop, which processes all queued events.
122 while(1) {
123 # Get the amount of elements in our queue.
124 # "undef" will be returned if it is empty.
125 my $current_events = $queue->pending();
126
127 # If there is at least one element enqued
128 if($current_events > 0) {
129 # Grab the data of the top enqueued event.
130 my $event = $queue->peek();
131
132 # Log processed event.
133 $logger->Log("debug", "QUEUE - Processed event: $event");
134
135 # Send event data to the events parser to determine
136 # if any action is required.
137 $events->CheckAction($event);
138
139 # Drop processed event from queue.
140 $queue->dequeue();
141 }
142
143 # Call RemoveBlocks routine from the Events module to check
144 # if items from the block list can be dropped.
145 $events->RemoveBlocks();
146
147 # Sleep 10ms to reduce the load of the main process.
148 sleep(0.01);
149 }
150
151 #
152 ## Init function.
153 #
154 ## This function contains code which has to be executed while guardian
155 ## is starting.
156 #
157 sub Init () {
158 # Setup signal handler.
159 &SignalHandler();
160
161 # Setup IPC mechanism via Socket in an own thread.
162 threads->create(\&Socket);
163
164 # Generate hash of monitored files.
165 %monitored_files = &Guardian::Base::GenerateMonitoredFiles(\%mainsettings, \%monitored_files);
166
167 # Start worker threads.
168 &StartWorkers();
169 }
170
171 #
172 ## Worker function.
173 #
174 ## This function is responsible for monitoring modifications of the given logfile,
175 ## read them and pass them to the message parser.
176 #
177 ## To get file modifications the inotify subsystem of the linux kernel is used.
178 #
179 ## In order to prevent from permanently read and keep files opened, or dealing
180 ## with huge logfiles, at initialization time of the worker process, the file will
181 ## be opened once and the cursor position of the end of file (EOF) get stored. When
182 ## reading any newly added lines from the file, we directly can jump to the last
183 ## known position and get these lines. Afterwards, we store the current curser position
184 ## again, so we can do it in this way over and over again.
185 #
186 ## All read lines get stored in an array, which will be passed to the Parser.
187 #
188 ## If any response (action) from the parser get recieved, it will be put into the
189 ## shared event queue.
190 #
191 sub Worker ($) {
192 my $file = $_[0];
193
194 # Obtain the parser name which should be used to parser any
195 # messages of this file.
196 my $parser = $monitored_files{$file};
197
198 # Signal handler to kill worker.
199 $SIG{'KILL'} = sub { threads->exit(); };
200
201 # Create inotify watcher.
202 my $watcher = new Linux::Inotify2 or die "Could not use inotify. $!";
203
204 # Monitor the specified file.
205 $watcher->watch("$file", IN_MODIFY) or die "Could not monitor $file. $!";
206
207 # Switch watcher into non-blocking mode.
208 $watcher->blocking(0);
209
210 # Log successfully spawned worker.
211 $logger->Log("debug", "Spawned worker thread for: $file");
212
213 # Infinite loop.
214 while(1) {
215 # Check for any events and perform them, if there
216 # is a least one.
217 if ($watcher->read) {
218 my @message = ();
219
220 # Obtain fileposition from hash.
221 my $fileposition = $file_positions{$file};
222
223 # Open the file.
224 open (FILE, $file) or die "Could not open $file. $!";
225
226 # Seek to the last known position.
227 seek (FILE, $fileposition, 0);
228
229 # Get the log message.
230 while (my $line = <FILE>) {
231 # Remove any newlines.
232 chomp $line;
233
234 # Add all lines to the message array.
235 push (@message, $line);
236 }
237
238 {
239 # Lock shared hash.
240 lock(%file_positions);
241
242 # Update fileposition.
243 $file_positions{$file} = tell(FILE);
244 }
245
246 # Close file.
247 close(FILE);
248
249 # Send filename and message to the parser,
250 # which will return if any actions have to be performed.
251 my @actions = &Guardian::Parser::Parser("$parser", @message);
252
253 # Send the action to the main process and put it into
254 # the queue.
255 if (@actions) {
256 # Lock the queue.
257 lock($queue);
258
259 # Loop through the actions array, and perform
260 # every single action.
261 foreach my $action (@actions) {
262 # Prevent from enqueuing empty actions.
263 if (defined($action)) {
264 # Put the required action into the queue.
265 $queue->enqueue($action);
266 }
267 }
268 }
269 } else {
270 # Sleep for 10ms until the next round of the loop will start.
271 sleep(0.01);
272 }
273 }
274 }
275
276 #
277 ## Socket function.
278 #
279 ## This function uses the Socket module to create and listen to an UNIX socket.
280 ## It automatically accepts all incomming connections and pass the recieved
281 ## data messages to the the Message_Parser function which is also part of the
282 ## socket module.
283 #
284 ## If a valid command has been sent through the socket, the corresponding event
285 ## will be enqueued into the shared event queue.
286 #
287 sub Socket () {
288 # Create the Server socket by calling the responsible function.
289 my $server = &Guardian::Socket::Server($mainsettings{SocketOwner});
290
291 # Log successfull creation of socket.
292 $logger->Log("debug", "Listening to Socket...");
293
294 # Accept incomming connections from the socket.
295 while (my $connection = $server->accept()) {
296 # Autoflush the socket after the data
297 # has been recieved.
298 $connection->autoflush(1);
299
300 # Gather all data from the connection.
301 while (my $message = <$connection>) {
302 # Remove any newlines.
303 chomp($message);
304
305 # Log recieved socket command.
306 $logger->Log("debug", "Socket - Recieved message: $message");
307
308 # Send the recieved data message to the
309 # socket parser.
310 my $action = &Guardian::Socket::Message_Parser($message);
311
312 # If the parser returns to perform an action,
313 # add it to the main event queue.
314 if ($action) {
315 # Lock the queue.
316 lock($queue);
317
318 # Enqueue the returned action.
319 $queue->enqueue($action);
320 }
321 }
322 }
323 }
324
325 #
326 ## Function for capturing process signals.
327 #
328 ## This function captures any sent process signals and will call various
329 ## actions, basend on the captured signal.
330 #
331 sub SignalHandler {
332 $SIG{INT} = \&Shutdown;
333 $SIG{TERM} = \&Shutdown;
334 $SIG{QUIT} = \&Shutdown;
335 $SIG{HUP} = \&Reload;
336 }
337
338 #
339 ## Function to start the workers (threads) for all monitored files.
340 #
341 ## This function will loop through the hash of monitored files and will
342 ## spawn an own thread based worker for each file. Every created worker will
343 ## be added to the array of running workers.
344 #
345 sub StartWorkers () {
346 # Init/Update hash which contains the cursor position of EOF.
347 %file_positions = &Guardian::Base::FilePositions(\%monitored_files, \%file_positions);
348
349 # Loop through the hash which contains the monitored files and start
350 # a worker thread for each single one.
351 foreach my $file (keys %monitored_files) {
352 $logger->Log("debug", "Starting worker thread for $file");
353 # Create worker thread for the file.
354 push @running_workers, threads->create(\&Worker,$file);
355 }
356 }
357
358 #
359 ## Function to stop all running workers.
360 #
361 ## This function is used to stop all currently running workers and will be
362 ## called when reloading or shutting down guardian.
363 #
364 sub StopWorkers () {
365 # Loop through all running workers.
366 foreach my $worker (@running_workers) {
367 # Send the worker the "KILL" signal and detach the
368 # thread so perl can do an automatically clean-up.
369 $worker->kill('KILL');
370 }
371 $logger->Log("debug", "All workers are stopped now...");
372 }
373
374 #
375 ## Reload function.
376 #
377 ## This function will get called if the signal handler recieves a "SIGHUP" signal,
378 ## or the reload command will be sent via socket connection. It is responsible for
379 ## reloading all configure options and stopping/starting the worker threads.
380 #
381 sub Reload () {
382 # Log reload.
383 $logger->Log("info", "Reload configuration...");
384
385 # Stop all running workers.
386 &StopWorkers();
387
388 # Re-read configuration file.
389 %mainsettings = &Guardian::Config::UseConfig($cmdargs{"config"});
390
391 # Update Logger settings.
392 $logger = Guardian::Logger->Init(%mainsettings);
393
394 # Update logger object in mainsettings hash.
395 $mainsettings{Logger} = $logger;
396
397 # Update ignore list, if one has been specified.
398 if (exists($mainsettings{IgnoreFile})) {
399 &Guardian::Events::GenerateIgnoreList($mainsettings{IgnoreFile});
400 }
401
402 # Re-generate hash of monitored files.
403 %monitored_files = &Guardian::Base::GenerateMonitoredFiles(\%mainsettings, \%monitored_files);
404
405 # Restart the worker threads.
406 &StartWorkers();
407 }
408
409 #
410 ## Shutdown function.
411 #
412 ## This function is used to do a clean shutdown of guardian. It will be called
413 ## by the signal handler when recieving INT (2), QUIT (3) and TERM (15) signals.
414 #
415 sub Shutdown () {
416 # Log shutdown.
417 $logger->Log("info", "Shutting down...");
418
419 # Stop all workers.
420 &StopWorkers();
421
422 # Remove socket file on exit.
423 &Guardian::Socket::RemoveSocketFile();
424
425 # Remove pid file on exit.
426 &Guardian::Daemon::RemovePIDFile();
427
428 # Sleep for one second to give perl some
429 # time to proper clean up everything before
430 # exiting.
431 sleep(1);
432
433 # Log good bye message.
434 $logger->Log("debug", "Good Bye!");
435
436 # Exit guardian.
437 exit;
438 }