[people/stevee/guardian.git] / guardian

#!/usr/bin/perl
###############################################################################
#                                                                             #
# IPFire.org - A linux based firewall                                         #
# Copyright (C) 2015  IPFire Development Team                                 #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

use strict;
use threads;
use threads::shared;
use Getopt::Long;
use Thread::Queue;
use Linux::Inotify2;
use Time::HiRes qw[ time sleep ];

require Guardian::Base;
require Guardian::Config;
require Guardian::Logger;
require Guardian::Parser;
require Guardian::Socket;

use warnings;

# Disable warnings of unjoinded threads when stopping guardian.
no warnings 'threads';

# Define version.
my $version ="2.0";

# Get and store the given command line arguments in a hash.
my %cmdargs = ();

&GetOptions (\%cmdargs,
	'foreground|f',
	'config|c=s',
	'help|h',
	'version|v',
);

# Show help / version information.
if (defined($cmdargs{"help"})) {
	print "Guardian $version \n";
	print "Usage: guardian <optional arguments>\n";
	print " -c, --config\t\tspecifiy a configuration file other than the default (/etc/guardian/guardian.conf)\n";
	print " -f, --foreground\trun in the foreground (doesn't fork, any output goes to STDOUT)\n";
	print " -h, --help\t\tshows this help\n";
	print " -v, --version\t\tdisplay programm version and exit.\n";
	exit;
} elsif (defined($cmdargs{"version"})) {
	print "Guardian $version \n";
	exit;
}

# Read-in the configuration file and store the settings.
# Push the may be given config file argument.
my %mainsettings = &Guardian::Config::UseConfig($cmdargs{"config"});

# Initialize Logger.
my $logger = Guardian::Logger->New(%mainsettings);
$logger->Log("debug", "Logger successfully initialized...");

# Shared hash between the main process and all threads. It will store all
# monitored files and their current file position.
my %monitored_files :shared = ();

# Create the main queue. It is used to store and process all events which are
# reported and enqueued by the worker threads.
my $queue :shared = new Thread::Queue or die "Could not create new, empty queue. $!\n";;

# Array to store all currently running worker objects.
# (Does not include the socket thread)
my @running_workers;

# Call Init function to initzialize guardian.
&Init();

# Infinite main loop, which processes all queued events.
while(1) {
	# Get the amount of elements in our queue.
	# "undef" will be returned if it is empty.
	my $current_events = $queue->pending();

	# If there is at least one element enqued
	if($current_events > 0) {
		# Grab the data of the top enqueued event.
		my $event = $queue->peek();

		# Log processed event.
		$logger->Log("debug", "QUEUE - Processed event: $event");

		# Drop processed event from queue.
		$queue->dequeue();
	}

	# Sleep 10ms to reduce the load of the main process.
	sleep(0.01);
}

#
## Init function.
#
## This function contains code which has to be executed while guardian
## is starting.
#
sub Init () {
	# Setup signal handler.
	&SignalHandler();

	# Setup IPC mechanism via Socket in an own thread.
	threads->create(\&Socket);

	# Generate hash of monitored files.
	%monitored_files = &Guardian::Base::GenerateMonitoredFiles(\%mainsettings, \%monitored_files);

	# Start worker threads.
	&StartWorkers();
}

#
## Worker function.
#
## This function is responsible for monitoring modifications of the given logfile,
## read them and pass them to the message parser.
#
## To get file modifications the inotify subsystem of the linux kernel is used.
#
## In order to prevent from permanently read and keep files opened, or dealing
## with huge logfiles, at initialization time of the worker process, the file will
## be opened once and the cursor position of the end of file (EOF) get stored. When
## reading any newly added lines from the file, we directly can jump to the last
## known position and get these lines. Afterwards, we store the current curser position
## again, so we can do it in this way over and over again.
#
## All read lines get stored in an array, which will be passed to the Parser.
#
## If any response (action) from the parser get recieved, it will be put into the
## shared event queue.
#
sub Worker ($) {
	my $file = $_[0];

	# Signal handler to kill worker.
	$SIG{'KILL'} = sub { threads->exit(); };

	# Create inotify watcher.
	my $watcher = new Linux::Inotify2 or die "Could not use inotify. $!\n";

	# Monitor the specified file.
	$watcher->watch("$file", IN_MODIFY) or die "Could not monitor $file. $!\n";

	# Switch watcher into non-blocking mode.
	$watcher->blocking(0);

	# Log successfully spawned worker.
	$logger->Log("debug", "Spawned worker thread for: $file");

	# Infinite loop.
	while(1) {
		# Check for any events and perform them, if there
		# is a least one.
		if ($watcher->read) {
			my @message = ();

			# Obtain fileposition from hash.
			my $fileposition = $monitored_files{$file};

			# Open the file.
			open (FILE, $file) or die "Could not open $file. $!\n";

			# Seek to the last known position.
			seek (FILE, $fileposition, 0);

			# Get the log message.
			while (my $line = <FILE>) {
				# Remove any newlines.
				chomp $line;

				# Add all lines to the message array.
				push (@message, $line);
			}

			{
				# Lock shared hash.
				lock(%monitored_files);

				# Update fileposition.
				$monitored_files{$file} = tell(FILE);
			}

			# Close file.
			close(FILE);

			# Send filename and message to the parser,
			# which will return if an action has to be performed.
			my @action = &Guardian::Parser::Parser("$file", @message);

			# Send the action to the main process and put it into
			# the queue.
			if (@action) {
				# Lock the queue.
				lock($queue);

				# Put the required action into the queue.
				$queue->enqueue(@action);
			}
		} else {
			# Sleep for 10ms until the next round of the loop will start.
			sleep(0.01);
		}
	}
}

#
## Socket function.
#
## This function uses the Socket module to create and listen to an UNIX socket.
## It automatically accepts all incomming connections and pass the recieved
## data messages to the the Message_Parser function which is also part of the
## socket module.
#
## If a valid command has been sent through the socket, the corresponding event
## will be enqueued into the shared event queue.
#
sub Socket () {
	# Create the Server socket by calling the responsible function.
	my $server = &Guardian::Socket::Server();

	# Log successfull creation of socket.
	$logger->Log("debug", "Listening to Socket...");

        # Accept incomming connections from the socket.
        while (my $connection = $server->accept()) {
		# Autoflush the socket after the data
		# has been recieved.
		$connection->autoflush(1);

		# Gather all data from the connection.
		while (my $message = <$connection>) {
			# Remove any newlines.
			chomp($message);

			# Log recieved socket command.
			$logger->Log("debug", "Socket - Recieved message: $message");

			# Send the recieved data message to the
			# socket parser.
			my $action = &Guardian::Socket::Message_Parser($message);

			# If the parser returns to perform an action,
			# add it to the main event queue.
			if ($action) {
				# Lock the queue.
				lock($queue);

				# Enqueue the returned action.
				$queue->enqueue($action);
			}
		}
	}
}

#
## Function for capturing process signals.
#
## This function captures any sent process signals and will call various
## actions, basend on the captured signal.
#
sub SignalHandler {
	$SIG{INT} = \&Shutdown;
	$SIG{TERM} = \&Shutdown;
	$SIG{QUIT} = \&Shutdown;
	$SIG{HUP} = \&Reload;
}

#
## Function to start the workers (threads) for all monitored files.
#
## This function will loop through the hash of monitored files and will
## spawn an own thread based worker for each file. Every created worker will
## be added to the array of running workers.
#
sub StartWorkers () {
	# Loop through the hash which contains the monitored files and start
	# a worker thread for each single one.
	foreach my $file (keys %monitored_files) {
		$logger->Log("debug", "Starting worker thread for $file");
		# Create worker thread for the file.
		push @running_workers, threads->create(\&Worker,$file);
	}
}

#
## Function to stop all running workers.
#
## This function is used to stop all currently running workers and will be
## called when reloading or shutting down guardian.
#
sub StopWorkers () {
	# Loop through all running workers.
	foreach my $worker (@running_workers) {
		# Send the worker the "KILL" signal and detach the
		# thread so perl can do an automatically clean-up.
		$worker->kill('KILL');
	}
	$logger->Log("debug", "All workers are stopped now...");
}

#
## Reload function.
#
## This function will get called if the signal handler recieves a "SIGHUP" signal,
## or the reload command will be sent via socket connection. It is responsible for
## reloading all configure options and stopping/starting the worker threads.
#
sub Reload () {
	# Log reload.
	$logger->Log("info", "Reload configuration...");

	# Stop all running workers.
	&StopWorkers();

	# Re-read configuration file.
	%mainsettings = &Guardian::Config::UseConfig($cmdargs{"config"});

	# Re-generate hash of monitored files.
	%monitored_files = &Guardian::Base::GenerateMonitoredFiles(\%mainsettings, \%monitored_files);

	# Restart the worker threads.
	&StartWorkers();
}

#
## Shutdown function.
#
## This function is used to do a clean shutdown of guardian. It will be called
## by the signal handler when recieving INT (2), QUIT (3) and TERM (15) signals.
#
sub Shutdown () {
	# Log shutdown.
	$logger->Log("info", "Shutting down...");

	# Stop all workers.
	&StopWorkers();

	# Remove socket file on exit.
	&Guardian::Socket::RemoveSocketFile();

	# Sleep for one second to give perl some
	# time to proper clean up everything before
	# exiting.
	sleep(1);

	# Log good bye message.
	$logger->Log("debug", "Good Bye!");

	# Exit guardian.
	exit;
}
Commit	Line	Data
	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::Logger;
	33	require Guardian::Parser;
	34	require Guardian::Socket;
	35
	36	use warnings;
	37
	38	# Disable warnings of unjoinded threads when stopping guardian.
	39	no warnings 'threads';
	40
	41	# Define version.
	42	my $version ="2.0";
	43
	44	# Get and store the given command line arguments in a hash.
	45	my %cmdargs = ();
	46
	47	&GetOptions (\%cmdargs,
	48	'foreground\|f',
	49	'config\|c=s',
	50	'help\|h',
	51	'version\|v',
	52	);
	53
	54	# Show help / version information.
	55	if (defined($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 $version \n";
	65	exit;
	66	}
	67
	68	# Read-in the configuration file and store the settings.
	69	# Push the may be given config file argument.
	70	my %mainsettings = &Guardian::Config::UseConfig($cmdargs{"config"});
	71
	72	# Initialize Logger.
	73	my $logger = Guardian::Logger->New(%mainsettings);
	74	$logger->Log("debug", "Logger successfully initialized...");
	75
	76	# Shared hash between the main process and all threads. It will store all
	77	# monitored files and their current file position.
	78	my %monitored_files :shared = ();
	79
	80	# Create the main queue. It is used to store and process all events which are
	81	# reported and enqueued by the worker threads.
	82	my $queue :shared = new Thread::Queue or die "Could not create new, empty queue. $!\n";;
	83
	84	# Array to store all currently running worker objects.
	85	# (Does not include the socket thread)
	86	my @running_workers;
	87
	88	# Call Init function to initzialize guardian.
	89	&Init();
	90
	91	# Infinite main loop, which processes all queued events.
	92	while(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
	102	# Log processed event.
	103	$logger->Log("debug", "QUEUE - Processed event: $event");
	104
	105	# Drop processed event from queue.
	106	$queue->dequeue();
	107	}
	108
	109	# Sleep 10ms to reduce the load of the main process.
	110	sleep(0.01);
	111	}
	112
	113	#
	114	## Init function.
	115	#
	116	## This function contains code which has to be executed while guardian
	117	## is starting.
	118	#
	119	sub Init () {
	120	# Setup signal handler.
	121	&SignalHandler();
	122
	123	# Setup IPC mechanism via Socket in an own thread.
	124	threads->create(\&Socket);
	125
	126	# Generate hash of monitored files.
	127	%monitored_files = &Guardian::Base::GenerateMonitoredFiles(\%mainsettings, \%monitored_files);
	128
	129	# Start worker threads.
	130	&StartWorkers();
	131	}
	132
	133	#
	134	## Worker function.
	135	#
	136	## This function is responsible for monitoring modifications of the given logfile,
	137	## read them and pass them to the message parser.
	138	#
	139	## To get file modifications the inotify subsystem of the linux kernel is used.
	140	#
	141	## In order to prevent from permanently read and keep files opened, or dealing
	142	## with huge logfiles, at initialization time of the worker process, the file will
	143	## be opened once and the cursor position of the end of file (EOF) get stored. When
	144	## reading any newly added lines from the file, we directly can jump to the last
	145	## known position and get these lines. Afterwards, we store the current curser position
	146	## again, so we can do it in this way over and over again.
	147	#
	148	## All read lines get stored in an array, which will be passed to the Parser.
	149	#
	150	## If any response (action) from the parser get recieved, it will be put into the
	151	## shared event queue.
	152	#
	153	sub Worker ($) {
	154	my $file = $_[0];
	155
	156	# Signal handler to kill worker.
	157	$SIG{'KILL'} = sub { threads->exit(); };
	158
	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
	165	# Switch watcher into non-blocking mode.
	166	$watcher->blocking(0);
	167
	168	# Log successfully spawned worker.
	169	$logger->Log("debug", "Spawned worker thread for: $file");
	170
	171	# Infinite loop.
	172	while(1) {
	173	# Check for any events and perform them, if there
	174	# is a least one.
	175	if ($watcher->read) {
	176	my @message = ();
	177
	178	# Obtain fileposition from hash.
	179	my $fileposition = $monitored_files{$file};
	180
	181	# Open the file.
	182	open (FILE, $file) or die "Could not open $file. $!\n";
	183
	184	# Seek to the last known position.
	185	seek (FILE, $fileposition, 0);
	186
	187	# Get the log message.
	188	while (my $line = <FILE>) {
	189	# Remove any newlines.
	190	chomp $line;
	191
	192	# Add all lines to the message array.
	193	push (@message, $line);
	194	}
	195
	196	{
	197	# Lock shared hash.
	198	lock(%monitored_files);
	199
	200	# Update fileposition.
	201	$monitored_files{$file} = tell(FILE);
	202	}
	203
	204	# Close file.
	205	close(FILE);
	206
	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("$file", @message);
	210
	211	# Send the action to the main process and put it into
	212	# the queue.
	213	if (@action) {
	214	# Lock the queue.
	215	lock($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);
	223	}
	224	}
	225	}
	226
	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	#
	238	sub Socket () {
	239	# Create the Server socket by calling the responsible function.
	240	my $server = &Guardian::Socket::Server();
	241
	242	# Log successfull creation of socket.
	243	$logger->Log("debug", "Listening to Socket...");
	244
	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
	256	# Log recieved socket command.
	257	$logger->Log("debug", "Socket - Recieved message: $message");
	258
	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
	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	#
	282	sub SignalHandler {
	283	$SIG{INT} = \&Shutdown;
	284	$SIG{TERM} = \&Shutdown;
	285	$SIG{QUIT} = \&Shutdown;
	286	$SIG{HUP} = \&Reload;
	287	}
	288
	289	#
	290	## Function to start the workers (threads) for all monitored files.
	291	#
	292	## This function will loop through the hash of monitored files and will
	293	## spawn an own thread based worker for each file. Every created worker will
	294	## be added to the array of running workers.
	295	#
	296	sub StartWorkers () {
	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) {
	300	$logger->Log("debug", "Starting worker thread for $file");
	301	# Create worker thread for the file.
	302	push @running_workers, threads->create(\&Worker,$file);
	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	#
	312	sub 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.
	317	$worker->kill('KILL');
	318	}
	319	$logger->Log("debug", "All workers are stopped now...");
	320	}
	321
	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	#
	329	sub Reload () {
	330	# Log reload.
	331	$logger->Log("info", "Reload configuration...");
	332
	333	# Stop all running workers.
	334	&StopWorkers();
	335
	336	# Re-read configuration file.
	337	%mainsettings = &Guardian::Config::UseConfig($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
	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	#
	352	sub Shutdown () {
	353	# Log shutdown.
	354	$logger->Log("info", "Shutting down...");
	355
	356	# Stop all workers.
	357	&StopWorkers();
	358
	359	# Remove socket file on exit.
	360	&Guardian::Socket::RemoveSocketFile();
	361
	362	# Sleep for one second to give perl some
	363	# time to proper clean up everything before
	364	# exiting.
	365	sleep(1);
	366
	367	# Log good bye message.
	368	$logger->Log("debug", "Good Bye!");
	369
	370	# Exit guardian.
	371	exit;
	372	}