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git.ipfire.org Git - people/stevee/guardian.git/blob - guardian
2 ###############################################################################
4 # IPFire.org - A linux based firewall #
5 # Copyright (C) 2015 IPFire Development Team #
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. #
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. #
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/>. #
20 ###############################################################################
28 use Time
::HiRes qw
[ time sleep ];
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
;
40 # Disable warnings of unjoinded threads when stopping guardian.
41 no warnings
'threads';
46 # Get and store the given command line arguments in a hash.
49 &GetOptions
(\
%cmdargs,
56 # Show help / version information.
57 if (defined($cmdargs{"help"})) {
58 print "Guardian $version \n";
59 print "Usage: guardian <optional arguments>\n";
60 print " -c, --config\t\tspecifiy a configuration file other than the default (/etc/guardian/guardian.conf)\n";
61 print " -f, --foreground\trun in the foreground (doesn't fork, any output goes to STDOUT)\n";
62 print " -h, --help\t\tshows this help\n";
63 print " -v, --version\t\tdisplay programm version and exit.\n";
65 } elsif (defined($cmdargs{"version"})) {
66 print "Guardian $version \n";
70 # Check if another instance of guardian is allready running.
71 if (&Guardian
::Daemon
::IsRunning
()) {
72 die "Another instance of Guardian is allready running...\n";
75 # Read-in the configuration file and store the settings.
76 # Push the may be given config file argument.
77 my %mainsettings = &Guardian
::Config
::UseConfig
($cmdargs{"config"});
80 my $logger = Guardian
::Logger
->Init(%mainsettings);
81 $logger->Log("debug", "Logger successfully initialized...");
83 # Add the logger object to the mainsettings for passing
85 $mainsettings{Logger
} = $logger;
87 # Redirect perls "die" messages to the logger before exiting.
88 $SIG{__DIE__
} = sub { $logger->Log("err", "@_"); };
90 # Initialize the event handler.
91 my $events = Guardian
::Events
->Init(%mainsettings);
93 # Shared hash between the main process and all threads. It will store all
94 # monitored files and their current file position.
95 my %monitored_files :shared
= ();
97 # Create the main queue. It is used to store and process all events which are
98 # reported and enqueued by the worker threads.
99 my $queue :shared
= new Thread
::Queue
or die "Could not create new, empty queue. $!";;
101 # Array to store all currently running worker objects.
102 # (Does not include the socket thread)
105 # Check if guardian should be daemonized or keep in the foreground.
106 unless (defined($cmdargs{"foreground"})) {
107 # Fork into background.
108 &Guardian
::Daemon
::Daemonize
();
110 # Write PID (process-id).
111 &Guardian
::Daemon
::WritePID
();
114 # Call Init function to initzialize guardian.
117 # Infinite main loop, which processes all queued events.
119 # Get the amount of elements in our queue.
120 # "undef" will be returned if it is empty.
121 my $current_events = $queue->pending();
123 # If there is at least one element enqued
124 if($current_events > 0) {
125 # Grab the data of the top enqueued event.
126 my $event = $queue->peek();
128 # Log processed event.
129 $logger->Log("debug", "QUEUE - Processed event: $event");
131 # Send event data to the events parser to determine
132 # if any action is required.
133 $events->CheckAction($event);
135 # Drop processed event from queue.
139 # Call RemoveBlocks routine from the Events module to check
140 # if items from the block list can be dropped.
141 $events->RemoveBlocks();
143 # Sleep 10ms to reduce the load of the main process.
150 ## This function contains code which has to be executed while guardian
154 # Setup signal handler.
157 # Setup IPC mechanism via Socket in an own thread.
158 threads
->create(\
&Socket
);
160 # Generate hash of monitored files.
161 %monitored_files = &Guardian
::Base
::GenerateMonitoredFiles
(\
%mainsettings, \
%monitored_files);
163 # Start worker threads.
170 ## This function is responsible for monitoring modifications of the given logfile,
171 ## read them and pass them to the message parser.
173 ## To get file modifications the inotify subsystem of the linux kernel is used.
175 ## In order to prevent from permanently read and keep files opened, or dealing
176 ## with huge logfiles, at initialization time of the worker process, the file will
177 ## be opened once and the cursor position of the end of file (EOF) get stored. When
178 ## reading any newly added lines from the file, we directly can jump to the last
179 ## known position and get these lines. Afterwards, we store the current curser position
180 ## again, so we can do it in this way over and over again.
182 ## All read lines get stored in an array, which will be passed to the Parser.
184 ## If any response (action) from the parser get recieved, it will be put into the
185 ## shared event queue.
190 # Signal handler to kill worker.
191 $SIG{'KILL'} = sub { threads
->exit(); };
193 # Create inotify watcher.
194 my $watcher = new Linux
::Inotify2
or die "Could not use inotify. $!";
196 # Monitor the specified file.
197 $watcher->watch("$file", IN_MODIFY
) or die "Could not monitor $file. $!";
199 # Switch watcher into non-blocking mode.
200 $watcher->blocking(0);
202 # Log successfully spawned worker.
203 $logger->Log("debug", "Spawned worker thread for: $file");
207 # Check for any events and perform them, if there
209 if ($watcher->read) {
212 # Obtain fileposition from hash.
213 my $fileposition = $monitored_files{$file};
216 open (FILE
, $file) or die "Could not open $file. $!";
218 # Seek to the last known position.
219 seek (FILE
, $fileposition, 0);
221 # Get the log message.
222 while (my $line = <FILE
>) {
223 # Remove any newlines.
226 # Add all lines to the message array.
227 push (@message, $line);
232 lock(%monitored_files);
234 # Update fileposition.
235 $monitored_files{$file} = tell(FILE
);
241 # Send filename and message to the parser,
242 # which will return if an action has to be performed.
243 my @action = &Guardian
::Parser
::Parser
("$file", @message);
245 # Send the action to the main process and put it into
251 # Put the required action into the queue.
252 $queue->enqueue(@action);
255 # Sleep for 10ms until the next round of the loop will start.
264 ## This function uses the Socket module to create and listen to an UNIX socket.
265 ## It automatically accepts all incomming connections and pass the recieved
266 ## data messages to the the Message_Parser function which is also part of the
269 ## If a valid command has been sent through the socket, the corresponding event
270 ## will be enqueued into the shared event queue.
273 # Create the Server socket by calling the responsible function.
274 my $server = &Guardian
::Socket
::Server
();
276 # Log successfull creation of socket.
277 $logger->Log("debug", "Listening to Socket...");
279 # Accept incomming connections from the socket.
280 while (my $connection = $server->accept()) {
281 # Autoflush the socket after the data
283 $connection->autoflush(1);
285 # Gather all data from the connection.
286 while (my $message = <$connection>) {
287 # Remove any newlines.
290 # Log recieved socket command.
291 $logger->Log("debug", "Socket - Recieved message: $message");
293 # Send the recieved data message to the
295 my $action = &Guardian
::Socket
::Message_Parser
($message);
297 # If the parser returns to perform an action,
298 # add it to the main event queue.
303 # Enqueue the returned action.
304 $queue->enqueue($action);
311 ## Function for capturing process signals.
313 ## This function captures any sent process signals and will call various
314 ## actions, basend on the captured signal.
317 $SIG{INT
} = \
&Shutdown
;
318 $SIG{TERM
} = \
&Shutdown
;
319 $SIG{QUIT
} = \
&Shutdown
;
320 $SIG{HUP
} = \
&Reload
;
324 ## Function to start the workers (threads) for all monitored files.
326 ## This function will loop through the hash of monitored files and will
327 ## spawn an own thread based worker for each file. Every created worker will
328 ## be added to the array of running workers.
330 sub StartWorkers
() {
331 # Loop through the hash which contains the monitored files and start
332 # a worker thread for each single one.
333 foreach my $file (keys %monitored_files) {
334 $logger->Log("debug", "Starting worker thread for $file");
335 # Create worker thread for the file.
336 push @running_workers, threads
->create(\
&Worker
,$file);
341 ## Function to stop all running workers.
343 ## This function is used to stop all currently running workers and will be
344 ## called when reloading or shutting down guardian.
347 # Loop through all running workers.
348 foreach my $worker (@running_workers) {
349 # Send the worker the "KILL" signal and detach the
350 # thread so perl can do an automatically clean-up.
351 $worker->kill('KILL');
353 $logger->Log("debug", "All workers are stopped now...");
359 ## This function will get called if the signal handler recieves a "SIGHUP" signal,
360 ## or the reload command will be sent via socket connection. It is responsible for
361 ## reloading all configure options and stopping/starting the worker threads.
365 $logger->Log("info", "Reload configuration...");
367 # Stop all running workers.
370 # Re-read configuration file.
371 %mainsettings = &Guardian
::Config
::UseConfig
($cmdargs{"config"});
373 # Update Logger settings.
374 $logger = Guardian
::Logger
->Init(%mainsettings);
376 # Update logger object in mainsettings hash.
377 $mainsettings{Logger
} = $logger;
379 # Re-generate hash of monitored files.
380 %monitored_files = &Guardian
::Base
::GenerateMonitoredFiles
(\
%mainsettings, \
%monitored_files);
382 # Restart the worker threads.
387 ## Shutdown function.
389 ## This function is used to do a clean shutdown of guardian. It will be called
390 ## by the signal handler when recieving INT (2), QUIT (3) and TERM (15) signals.
394 $logger->Log("info", "Shutting down...");
399 # Remove socket file on exit.
400 &Guardian
::Socket
::RemoveSocketFile
();
402 # Remove pid file on exit.
403 &Guardian
::Daemon
::RemovePIDFile
();
405 # Sleep for one second to give perl some
406 # time to proper clean up everything before
410 # Log good bye message.
411 $logger->Log("debug", "Good Bye!");