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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
::Parser
;
33 require Guardian
::Socket
;
40 # Get and store the given command line arguments in a hash.
43 &GetOptions
(\
%cmdargs,
50 # Show help / version information.
51 if (defined($cmdargs{"help"})) {
52 print "Guardian $version \n";
53 print "Usage: guardian <optional arguments>\n";
54 print " -c, --config\t\tspecifiy a configuration file other than the default (/etc/guardian/guardian.conf)\n";
55 print " -f, --foreground\trun in the foreground (doesn't fork, any output goes to STDOUT)\n";
56 print " -h, --help\t\tshows this help\n";
57 print " -v, --version\t\tdisplay programm version and exit.\n";
59 } elsif (defined($cmdargs{"version"})) {
60 print "Guardian $version \n";
64 # Read-in the configuration file and store the settings.
65 # Push the may be given config file argument.
66 my %mainsettings = &Guardian
::Config
::UseConfig
($cmdargs{"config"});
68 # Shared hash between the main process and all threads. It will store all
69 # monitored files and their current file position.
70 my %monitored_files :shared
= ();
72 # Create the main queue. It is used to store and process all events which are
73 # reported and enqueued by the worker threads.
74 my $queue :shared
= new Thread
::Queue
or die "Could not create new, empty queue. $!\n";;
76 # Array to store all currently running worker objects.
77 # (Does not include the socket thread)
80 # Call Init function to initzialize guardian.
83 # Infinite main loop, which processes all queued events.
85 # Get the amount of elements in our queue.
86 # "undef" will be returned if it is empty.
87 my $current_events = $queue->pending();
89 # If there is at least one element enqued
90 if($current_events > 0) {
91 # Grab the data of the top enqueued event.
92 my $event = $queue->peek();
94 print "Got event: $event\n";
96 # Drop processed event from queue.
100 # Sleep 10ms to reduce the load of the main process.
107 ## This function contains code which has to be executed while guardian
111 # Setup signal handler.
114 # Setup IPC mechanism via Socket in an own thread.
115 threads
->create(\
&Socket
);
117 # Generate hash of monitored files.
118 %monitored_files = &Guardian
::Base
::GenerateMonitoredFiles
(\
%mainsettings, \
%monitored_files);
120 # Start worker threads.
127 ## This function is responsible for monitoring modifications of the given logfile,
128 ## read them and pass them to the message parser.
130 ## To get file modifications the inotify subsystem of the linux kernel is used.
132 ## In order to prevent from permanently read and keep files opened, or dealing
133 ## with huge logfiles, at initialization time of the worker process, the file will
134 ## be opened once and the cursor position of the end of file (EOF) get stored. When
135 ## reading any newly added lines from the file, we directly can jump to the last
136 ## known position and get these lines. Afterwards, we store the current curser position
137 ## again, so we can do it in this way over and over again.
139 ## All read lines get stored in an array, which will be passed to the Parser.
141 ## If any response (action) from the parser get recieved, it will be put into the
142 ## shared event queue.
147 # Signal handler to kill worker.
148 $SIG{'KILL'} = sub { threads
->exit(); };
150 # Create inotify watcher.
151 my $watcher = new Linux
::Inotify2
or die "Could not use inotify. $!\n";
153 # Monitor the specified file.
154 $watcher->watch("$file", IN_MODIFY
) or die "Could not monitor $file. $!\n";
156 # Switch watcher into non-blocking mode.
157 $watcher->blocking(0);
161 # Check for any events and perform them, if there
163 if ($watcher->read) {
166 # Obtain fileposition from hash.
167 my $fileposition = $monitored_files{$file};
170 open (FILE
, $file) or die "Could not open $file. $!\n";
172 # Seek to the last known position.
173 seek (FILE
, $fileposition, 0);
175 # Get the log message.
176 while (my $line = <FILE
>) {
177 # Remove any newlines.
180 # Add all lines to the message array.
181 push (@message, $line);
186 lock(%monitored_files);
188 # Update fileposition.
189 $monitored_files{$file} = tell(FILE
);
195 # Send filename and message to the parser,
196 # which will return if an action has to be performed.
197 my @action = &Guardian
::Parser
::Parser
("$file", @message);
199 # Send the action to the main process and put it into
205 # Put the required action into the queue.
206 $queue->enqueue(@action);
209 # Sleep for 10ms until the next round of the loop will start.
218 ## This function uses the Socket module to create and listen to an UNIX socket.
219 ## It automatically accepts all incomming connections and pass the recieved
220 ## data messages to the the Message_Parser function which is also part of the
223 ## If a valid command has been sent through the socket, the corresponding event
224 ## will be enqueued into the shared event queue.
227 # Create the Server socket by calling the responsible function.
228 my $server = &Guardian
::Socket
::Server
();
230 # Accept incomming connections from the socket.
231 while (my $connection = $server->accept()) {
232 # Autoflush the socket after the data
234 $connection->autoflush(1);
236 # Gather all data from the connection.
237 while (my $message = <$connection>) {
238 # Remove any newlines.
241 # Send the recieved data message to the
243 my $action = &Guardian
::Socket
::Message_Parser
($message);
245 # If the parser returns to perform an action,
246 # add it to the main event queue.
251 # Enqueue the returned action.
252 $queue->enqueue($action);
259 ## Function for capturing process signals.
261 ## This function captures any sent process signals and will call various
262 ## actions, basend on the captured signal.
265 $SIG{INT
} = \
&Shutdown
;
266 $SIG{TERM
} = \
&Shutdown
;
267 $SIG{QUIT
} = \
&Shutdown
;
268 $SIG{HUP
} = \
&Reload
;
272 ## Function to start the workers (threads) for all monitored files.
274 ## This function will loop through the hash of monitored files and will
275 ## spawn an own thread based worker for each file. Every created worker will
276 ## be added to the array of running workers.
278 sub StartWorkers
() {
279 # Loop through the hash which contains the monitored files and start
280 # a worker thread for each single one.
281 foreach my $file (keys %monitored_files) {
282 # Create worker thread for the file.
283 push @running_workers, threads
->create(\
&Worker
,$file);
288 ## Function to stop all running workers.
290 ## This function is used to stop all currently running workers and will be
291 ## called when reloading or shutting down guardian.
294 # Loop through all running workers.
295 foreach my $worker (@running_workers) {
296 # Send the worker the "KILL" signal and detach the
297 # thread so perl can do an automatically clean-up.
298 $worker->kill('KILL')->detach();
305 ## This function will get called if the signal handler recieves a "SIGHUP" signal,
306 ## or the reload command will be sent via socket connection. It is responsible for
307 ## reloading all configure options and stopping/starting the worker threads.
310 # Stop all running workers.
313 # Re-read configuration file.
314 %mainsettings = &Guardian
::Config
::UseConfig
($cmdargs{"config"});
316 # Re-generate hash of monitored files.
317 %monitored_files = &Guardian
::Base
::GenerateMonitoredFiles
(\
%mainsettings, \
%monitored_files);
319 # Restart the worker threads.
324 ## Shutdown function.
326 ## This function is used to do a clean shutdown of guardian. It will be called
327 ## by the signal handler when recieving INT (2), QUIT (3) and TERM (15) signals.
333 # Remove socket file on exit.
334 &Guardian
::Socket
::RemoveSocketFile
();
336 # Sleep for one second to give perl some
337 # time to proper clean up everything before