Use "Logger" module for logging purposes.
[people/stevee/guardian.git] / guardian
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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
22use strict;
23use threads;
24use threads::shared;
45bf2a03 25use Getopt::Long;
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26use Thread::Queue;
27use Linux::Inotify2;
01147a7e 28use Time::HiRes qw[ time sleep ];
88d9af2c 29
3111df62 30require Guardian::Base;
45bf2a03 31require Guardian::Config;
c95dfa5b 32require Guardian::Logger;
88d9af2c 33require Guardian::Parser;
6abac3d4 34require Guardian::Socket;
88d9af2c 35
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36use warnings;
37
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38# Disable warnings of unjoinded threads when stopping guardian.
39no warnings 'threads';
40
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41# Define version.
42my $version ="2.0";
43
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44# Get and store the given command line arguments in a hash.
45my %cmdargs = ();
46
47&GetOptions (\%cmdargs,
48 'foreground|f',
49 'config|c=s',
50 'help|h',
51 'version|v',
52);
53
54# Show help / version information.
55if (defined($cmdargs{"help"})) {
56 print "Guardian $version \n";
57 print "Usage: guardian <optional arguments>\n";
58 print " -c, --config\t\tspecifiy a configuration file other than the default (/etc/guardian/guardian.conf)\n";
59 print " -f, --foreground\trun in the foreground (doesn't fork, any output goes to STDOUT)\n";
60 print " -h, --help\t\tshows this help\n";
61 print " -v, --version\t\tdisplay programm version and exit.\n";
62 exit;
63} elsif (defined($cmdargs{"version"})) {
64 print "Guardian $version \n";
65 exit;
66}
67
68# Read-in the configuration file and store the settings.
69# Push the may be given config file argument.
70my %mainsettings = &Guardian::Config::UseConfig($cmdargs{"config"});
71
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72# Initialize Logger.
73my $logger = Guardian::Logger->New(%mainsettings);
74$logger->Log("debug", "Logger successfully initialized...");
75
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76# Shared hash between the main process and all threads. It will store all
77# monitored files and their current file position.
78my %monitored_files :shared = ();
79
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80# Create the main queue. It is used to store and process all events which are
81# reported and enqueued by the worker threads.
82my $queue :shared = new Thread::Queue or die "Could not create new, empty queue. $!\n";;
83
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84# Array to store all currently running worker objects.
85# (Does not include the socket thread)
86my @running_workers;
87
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88# Call Init function to initzialize guardian.
89&Init();
90
91# Infinite main loop, which processes all queued events.
92while(1) {
93 # Get the amount of elements in our queue.
94 # "undef" will be returned if it is empty.
95 my $current_events = $queue->pending();
96
97 # If there is at least one element enqued
98 if($current_events > 0) {
99 # Grab the data of the top enqueued event.
100 my $event = $queue->peek();
101
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102 # Log processed event.
103 $logger->Log("debug", "QUEUE - Processed event: $event");
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104
105 # Drop processed event from queue.
106 $queue->dequeue();
107 }
108
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109 # Sleep 10ms to reduce the load of the main process.
110 sleep(0.01);
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111}
112
113#
114## Init function.
115#
116## This function contains code which has to be executed while guardian
117## is starting.
118#
119sub Init () {
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120 # Setup signal handler.
121 &SignalHandler();
122
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123 # Setup IPC mechanism via Socket in an own thread.
124 threads->create(\&Socket);
125
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126 # Generate hash of monitored files.
127 %monitored_files = &Guardian::Base::GenerateMonitoredFiles(\%mainsettings, \%monitored_files);
128
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129 # Start worker threads.
130 &StartWorkers();
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131}
132
133#
134## Worker function.
135#
136## This function is responsible for monitoring modifications of the given logfile,
137## read them and pass them to the message parser.
138#
139## To get file modifications the inotify subsystem of the linux kernel is used.
140#
141## In order to prevent from permanently read and keep files opened, or dealing
142## with huge logfiles, at initialization time of the worker process, the file will
143## be opened once and the cursor position of the end of file (EOF) get stored. When
144## reading any newly added lines from the file, we directly can jump to the last
145## known position and get these lines. Afterwards, we store the current curser position
146## again, so we can do it in this way over and over again.
147#
148## All read lines get stored in an array, which will be passed to the Parser.
149#
150## If any response (action) from the parser get recieved, it will be put into the
151## shared event queue.
152#
153sub Worker ($) {
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154 my $file = $_[0];
155
156 # Signal handler to kill worker.
157 $SIG{'KILL'} = sub { threads->exit(); };
88d9af2c 158
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159 # Create inotify watcher.
160 my $watcher = new Linux::Inotify2 or die "Could not use inotify. $!\n";
161
162 # Monitor the specified file.
163 $watcher->watch("$file", IN_MODIFY) or die "Could not monitor $file. $!\n";
164
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165 # Switch watcher into non-blocking mode.
166 $watcher->blocking(0);
88d9af2c 167
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168 # Log successfully spawned worker.
169 $logger->Log("debug", "Spawned worker thread for: $file");
170
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171 # Infinite loop.
172 while(1) {
173 # Check for any events and perform them, if there
174 # is a least one.
175 if ($watcher->read) {
176 my @message = ();
88d9af2c 177
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178 # Obtain fileposition from hash.
179 my $fileposition = $monitored_files{$file};
180
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181 # Open the file.
182 open (FILE, $file) or die "Could not open $file. $!\n";
88d9af2c 183
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184 # Seek to the last known position.
185 seek (FILE, $fileposition, 0);
88d9af2c 186
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187 # Get the log message.
188 while (my $line = <FILE>) {
189 # Remove any newlines.
190 chomp $line;
88d9af2c 191
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192 # Add all lines to the message array.
193 push (@message, $line);
194 }
88d9af2c 195
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196 {
197 # Lock shared hash.
198 lock(%monitored_files);
199
200 # Update fileposition.
201 $monitored_files{$file} = tell(FILE);
202 }
88d9af2c 203
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204 # Close file.
205 close(FILE);
88d9af2c 206
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207 # Send filename and message to the parser,
208 # which will return if an action has to be performed.
209 my @action = &Guardian::Parser::Parser("$file", @message);
88d9af2c 210
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211 # Send the action to the main process and put it into
212 # the queue.
213 if (@action) {
214 # Lock the queue.
215 lock($queue);
216
217 # Put the required action into the queue.
218 $queue->enqueue(@action);
219 }
220 } else {
221 # Sleep for 10ms until the next round of the loop will start.
222 sleep(0.01);
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223 }
224 }
225}
226
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227#
228## Socket function.
229#
230## This function uses the Socket module to create and listen to an UNIX socket.
231## It automatically accepts all incomming connections and pass the recieved
232## data messages to the the Message_Parser function which is also part of the
233## socket module.
234#
235## If a valid command has been sent through the socket, the corresponding event
236## will be enqueued into the shared event queue.
237#
238sub Socket () {
239 # Create the Server socket by calling the responsible function.
240 my $server = &Guardian::Socket::Server();
241
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242 # Log successfull creation of socket.
243 $logger->Log("debug", "Listening to Socket...");
244
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245 # Accept incomming connections from the socket.
246 while (my $connection = $server->accept()) {
247 # Autoflush the socket after the data
248 # has been recieved.
249 $connection->autoflush(1);
250
251 # Gather all data from the connection.
252 while (my $message = <$connection>) {
253 # Remove any newlines.
254 chomp($message);
255
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256 # Log recieved socket command.
257 $logger->Log("debug", "Socket - Recieved message: $message");
258
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259 # Send the recieved data message to the
260 # socket parser.
261 my $action = &Guardian::Socket::Message_Parser($message);
262
263 # If the parser returns to perform an action,
264 # add it to the main event queue.
265 if ($action) {
266 # Lock the queue.
267 lock($queue);
268
269 # Enqueue the returned action.
270 $queue->enqueue($action);
271 }
272 }
273 }
274}
275
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276#
277## Function for capturing process signals.
278#
279## This function captures any sent process signals and will call various
280## actions, basend on the captured signal.
281#
282sub SignalHandler {
283 $SIG{INT} = \&Shutdown;
284 $SIG{TERM} = \&Shutdown;
285 $SIG{QUIT} = \&Shutdown;
ba734c53 286 $SIG{HUP} = \&Reload;
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287}
288
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289#
290## Function to start the workers (threads) for all monitored files.
291#
3111df62 292## This function will loop through the hash of monitored files and will
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293## spawn an own thread based worker for each file. Every created worker will
294## be added to the array of running workers.
295#
296sub StartWorkers () {
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297 # Loop through the hash which contains the monitored files and start
298 # a worker thread for each single one.
299 foreach my $file (keys %monitored_files) {
c95dfa5b 300 $logger->Log("debug", "Starting worker thread for $file");
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301 # Create worker thread for the file.
302 push @running_workers, threads->create(\&Worker,$file);
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303 }
304}
305
306#
307## Function to stop all running workers.
308#
309## This function is used to stop all currently running workers and will be
310## called when reloading or shutting down guardian.
311#
312sub StopWorkers () {
313 # Loop through all running workers.
314 foreach my $worker (@running_workers) {
315 # Send the worker the "KILL" signal and detach the
316 # thread so perl can do an automatically clean-up.
4d19939e 317 $worker->kill('KILL');
9c74e9bb 318 }
c95dfa5b 319 $logger->Log("debug", "All workers are stopped now...");
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320}
321
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322#
323## Reload function.
324#
325## This function will get called if the signal handler recieves a "SIGHUP" signal,
326## or the reload command will be sent via socket connection. It is responsible for
327## reloading all configure options and stopping/starting the worker threads.
328#
329sub Reload () {
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330 # Log reload.
331 $logger->Log("info", "Reload configuration...");
332
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333 # Stop all running workers.
334 &StopWorkers();
335
336 # Re-read configuration file.
337 %mainsettings = &Guardian::Config::UseConfig($cmdargs{"config"});
338
339 # Re-generate hash of monitored files.
340 %monitored_files = &Guardian::Base::GenerateMonitoredFiles(\%mainsettings, \%monitored_files);
341
342 # Restart the worker threads.
343 &StartWorkers();
344}
345
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346#
347## Shutdown function.
348#
349## This function is used to do a clean shutdown of guardian. It will be called
350## by the signal handler when recieving INT (2), QUIT (3) and TERM (15) signals.
351#
352sub Shutdown () {
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353 # Log shutdown.
354 $logger->Log("info", "Shutting down...");
355
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356 # Stop all workers.
357 &StopWorkers();
358
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359 # Remove socket file on exit.
360 &Guardian::Socket::RemoveSocketFile();
361
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362 # Sleep for one second to give perl some
363 # time to proper clean up everything before
364 # exiting.
365 sleep(1);
366
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367 # Log good bye message.
368 $logger->Log("debug", "Good Bye!");
369
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370 # Exit guardian.
371 exit;
372}