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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
::Logger
;
34 require Guardian
::Parser
;
35 require Guardian
::Socket
;
39 # Disable warnings of unjoinded threads when stopping guardian.
40 no warnings
'threads';
45 # Get and store the given command line arguments in a hash.
48 &GetOptions
(\
%cmdargs,
55 # Show help / version information.
56 if (defined($cmdargs{"help"})) {
57 print "Guardian $version \n";
58 print "Usage: guardian <optional arguments>\n";
59 print " -c, --config\t\tspecifiy a configuration file other than the default (/etc/guardian/guardian.conf)\n";
60 print " -f, --foreground\trun in the foreground (doesn't fork, any output goes to STDOUT)\n";
61 print " -h, --help\t\tshows this help\n";
62 print " -v, --version\t\tdisplay programm version and exit.\n";
64 } elsif (defined($cmdargs{"version"})) {
65 print "Guardian $version \n";
69 # Read-in the configuration file and store the settings.
70 # Push the may be given config file argument.
71 my %mainsettings = &Guardian
::Config
::UseConfig
($cmdargs{"config"});
74 my $logger = Guardian
::Logger
->Init(%mainsettings);
75 $logger->Log("debug", "Logger successfully initialized...");
77 # Add the logger object to the mainsettings for passing
79 $mainsettings{Logger
} = $logger;
81 # Redirect perls "die" messages to the logger before exiting.
82 $SIG{__DIE__
} = sub { $logger->Log("err", "@_"); };
84 # Shared hash between the main process and all threads. It will store all
85 # monitored files and their current file position.
86 my %monitored_files :shared
= ();
88 # Create the main queue. It is used to store and process all events which are
89 # reported and enqueued by the worker threads.
90 my $queue :shared
= new Thread
::Queue
or die "Could not create new, empty queue. $!";;
92 # Array to store all currently running worker objects.
93 # (Does not include the socket thread)
96 # Check if guardian should be daemonized or keep in the foreground.
97 unless (defined($cmdargs{"foreground"})) {
98 # Fork into background.
99 &Guardian
::Daemon
::Daemonize
();
101 # Write PID (process-id).
102 &Guardian
::Daemon
::WritePID
();
105 # Call Init function to initzialize guardian.
108 # Infinite main loop, which processes all queued events.
110 # Get the amount of elements in our queue.
111 # "undef" will be returned if it is empty.
112 my $current_events = $queue->pending();
114 # If there is at least one element enqued
115 if($current_events > 0) {
116 # Grab the data of the top enqueued event.
117 my $event = $queue->peek();
119 # Log processed event.
120 $logger->Log("debug", "QUEUE - Processed event: $event");
122 # Drop processed event from queue.
126 # Sleep 10ms to reduce the load of the main process.
133 ## This function contains code which has to be executed while guardian
137 # Setup signal handler.
140 # Setup IPC mechanism via Socket in an own thread.
141 threads
->create(\
&Socket
);
143 # Generate hash of monitored files.
144 %monitored_files = &Guardian
::Base
::GenerateMonitoredFiles
(\
%mainsettings, \
%monitored_files);
146 # Start worker threads.
153 ## This function is responsible for monitoring modifications of the given logfile,
154 ## read them and pass them to the message parser.
156 ## To get file modifications the inotify subsystem of the linux kernel is used.
158 ## In order to prevent from permanently read and keep files opened, or dealing
159 ## with huge logfiles, at initialization time of the worker process, the file will
160 ## be opened once and the cursor position of the end of file (EOF) get stored. When
161 ## reading any newly added lines from the file, we directly can jump to the last
162 ## known position and get these lines. Afterwards, we store the current curser position
163 ## again, so we can do it in this way over and over again.
165 ## All read lines get stored in an array, which will be passed to the Parser.
167 ## If any response (action) from the parser get recieved, it will be put into the
168 ## shared event queue.
173 # Signal handler to kill worker.
174 $SIG{'KILL'} = sub { threads
->exit(); };
176 # Create inotify watcher.
177 my $watcher = new Linux
::Inotify2
or die "Could not use inotify. $!";
179 # Monitor the specified file.
180 $watcher->watch("$file", IN_MODIFY
) or die "Could not monitor $file. $!";
182 # Switch watcher into non-blocking mode.
183 $watcher->blocking(0);
185 # Log successfully spawned worker.
186 $logger->Log("debug", "Spawned worker thread for: $file");
190 # Check for any events and perform them, if there
192 if ($watcher->read) {
195 # Obtain fileposition from hash.
196 my $fileposition = $monitored_files{$file};
199 open (FILE
, $file) or die "Could not open $file. $!";
201 # Seek to the last known position.
202 seek (FILE
, $fileposition, 0);
204 # Get the log message.
205 while (my $line = <FILE
>) {
206 # Remove any newlines.
209 # Add all lines to the message array.
210 push (@message, $line);
215 lock(%monitored_files);
217 # Update fileposition.
218 $monitored_files{$file} = tell(FILE
);
224 # Send filename and message to the parser,
225 # which will return if an action has to be performed.
226 my @action = &Guardian
::Parser
::Parser
("$file", @message);
228 # Send the action to the main process and put it into
234 # Put the required action into the queue.
235 $queue->enqueue(@action);
238 # Sleep for 10ms until the next round of the loop will start.
247 ## This function uses the Socket module to create and listen to an UNIX socket.
248 ## It automatically accepts all incomming connections and pass the recieved
249 ## data messages to the the Message_Parser function which is also part of the
252 ## If a valid command has been sent through the socket, the corresponding event
253 ## will be enqueued into the shared event queue.
256 # Create the Server socket by calling the responsible function.
257 my $server = &Guardian
::Socket
::Server
();
259 # Log successfull creation of socket.
260 $logger->Log("debug", "Listening to Socket...");
262 # Accept incomming connections from the socket.
263 while (my $connection = $server->accept()) {
264 # Autoflush the socket after the data
266 $connection->autoflush(1);
268 # Gather all data from the connection.
269 while (my $message = <$connection>) {
270 # Remove any newlines.
273 # Log recieved socket command.
274 $logger->Log("debug", "Socket - Recieved message: $message");
276 # Send the recieved data message to the
278 my $action = &Guardian
::Socket
::Message_Parser
($message);
280 # If the parser returns to perform an action,
281 # add it to the main event queue.
286 # Enqueue the returned action.
287 $queue->enqueue($action);
294 ## Function for capturing process signals.
296 ## This function captures any sent process signals and will call various
297 ## actions, basend on the captured signal.
300 $SIG{INT
} = \
&Shutdown
;
301 $SIG{TERM
} = \
&Shutdown
;
302 $SIG{QUIT
} = \
&Shutdown
;
303 $SIG{HUP
} = \
&Reload
;
307 ## Function to start the workers (threads) for all monitored files.
309 ## This function will loop through the hash of monitored files and will
310 ## spawn an own thread based worker for each file. Every created worker will
311 ## be added to the array of running workers.
313 sub StartWorkers
() {
314 # Loop through the hash which contains the monitored files and start
315 # a worker thread for each single one.
316 foreach my $file (keys %monitored_files) {
317 $logger->Log("debug", "Starting worker thread for $file");
318 # Create worker thread for the file.
319 push @running_workers, threads
->create(\
&Worker
,$file);
324 ## Function to stop all running workers.
326 ## This function is used to stop all currently running workers and will be
327 ## called when reloading or shutting down guardian.
330 # Loop through all running workers.
331 foreach my $worker (@running_workers) {
332 # Send the worker the "KILL" signal and detach the
333 # thread so perl can do an automatically clean-up.
334 $worker->kill('KILL');
336 $logger->Log("debug", "All workers are stopped now...");
342 ## This function will get called if the signal handler recieves a "SIGHUP" signal,
343 ## or the reload command will be sent via socket connection. It is responsible for
344 ## reloading all configure options and stopping/starting the worker threads.
348 $logger->Log("info", "Reload configuration...");
350 # Stop all running workers.
353 # Re-read configuration file.
354 %mainsettings = &Guardian
::Config
::UseConfig
($cmdargs{"config"});
356 # Update Logger settings.
357 $logger = Guardian
::Logger
->Init(%mainsettings);
359 # Update logger object in mainsettings hash.
360 $mainsettings{Logger
} = $logger;
362 # Re-generate hash of monitored files.
363 %monitored_files = &Guardian
::Base
::GenerateMonitoredFiles
(\
%mainsettings, \
%monitored_files);
365 # Restart the worker threads.
370 ## Shutdown function.
372 ## This function is used to do a clean shutdown of guardian. It will be called
373 ## by the signal handler when recieving INT (2), QUIT (3) and TERM (15) signals.
377 $logger->Log("info", "Shutting down...");
382 # Remove socket file on exit.
383 &Guardian
::Socket
::RemoveSocketFile
();
385 # Remove pid file on exit.
386 &Guardian
::Daemon
::RemovePIDFile
();
388 # Sleep for one second to give perl some
389 # time to proper clean up everything before
393 # Log good bye message.
394 $logger->Log("debug", "Good Bye!");