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;
-# Array to store the monitored logfiles.
-my @monitored_files = (
- "/var/log/snort/alert",
+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...");
+
+# Add the logger object to the mainsettings for passing
+# it to the modules.
+$mainsettings{Logger} = $logger;
+
+# Redirect perls "die" messages to the logger before exiting.
+$SIG{__DIE__} = sub { $logger->Log("err", "@_"); };
+
+# 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";;
+my $queue :shared = new Thread::Queue or die "Could not create new, empty queue. $!";;
+
+# Array to store all currently running worker objects.
+# (Does not include the socket thread)
+my @running_workers;
# Call Init function to initzialize guardian.
&Init();
# Grab the data of the top enqueued event.
my $event = $queue->peek();
- print "Got event: $event\n";
+ # Log processed event.
+ $logger->Log("debug", "QUEUE - Processed event: $event");
# Drop processed event from queue.
$queue->dequeue();
}
- # XXX
- # Temporary workaround to reduce the load of the main process.
- sleep(1);
+ # Sleep 10ms to reduce the load of the main process.
+ sleep(0.01);
}
#
## is starting.
#
sub Init () {
- # Loop through the array of which files should be monitored and
- # create a worker thread for each single one.
- foreach my $monitored_file (@monitored_files) {
- # Check if the file exists and is readable.
- if (-r "$monitored_file") {
- # Create worker thread for the file.
- threads->create(\&Worker,$monitored_file);
- }
- }
+ # Setup signal handler.
+ &SignalHandler();
+
+ # Setup IPC mechanism via Socket in an own thread.
+ threads->create(\&Socket);
+
+ # Generate hash of monitored files.
+ %monitored_files = &Guardian::Base::GenerateMonitoredFiles(\%mainsettings, \%monitored_files);
+
+ # Start worker threads.
+ &StartWorkers();
}
#
## shared event queue.
#
sub Worker ($) {
- my $file = @_[0];
+ my $file = $_[0];
- # Get the fileposition.
- my $fileposition = &Init_fileposition("$file");
+ # 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";
+ my $watcher = new Linux::Inotify2 or die "Could not use inotify. $!";
# Monitor the specified file.
- $watcher->watch("$file", IN_MODIFY) or die "Could not monitor $file. $!\n";
+ $watcher->watch("$file", IN_MODIFY) or die "Could not monitor $file. $!";
- # Get all notifications.
- while ($watcher->read) {
- my @message = ();
+ # Switch watcher into non-blocking mode.
+ $watcher->blocking(0);
- # Open the file.
- open (FILE, $file) or die "Could not open $file. $!\n";
+ # Log successfully spawned worker.
+ $logger->Log("debug", "Spawned worker thread for: $file");
- # Seek to the last known position.
- seek (FILE, $fileposition, 0);
+ # Infinite loop.
+ while(1) {
+ # Check for any events and perform them, if there
+ # is a least one.
+ if ($watcher->read) {
+ my @message = ();
- # Get the log message.
- while (my $line = <FILE>) {
- # Remove any newlines.
- chomp $line;
+ # Obtain fileposition from hash.
+ my $fileposition = $monitored_files{$file};
+
+ # Open the file.
+ open (FILE, $file) or die "Could not open $file. $!";
+
+ # 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);
- # Add all lines to the message array.
- push (@message, $line);
+ # Send filename and message to the parser,
+ # which will return if an action has to be performed.
+ my @action = &Guardian::Parser::Parser("$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);
}
+ }
+}
- # Update fileposition.
- $fileposition = tell(FILE);
+#
+## 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();
- # Close file.
- close(FILE);
+ # Log successfull creation of socket.
+ $logger->Log("debug", "Listening to Socket...");
- # Send filename and message to the parser,
- # which will return if an action has to be performed.
- my @action = &Guardian::Parser::Parser("$file", @message);
+ # Accept incomming connections from the socket.
+ while (my $connection = $server->accept()) {
+ # Autoflush the socket after the data
+ # has been recieved.
+ $connection->autoflush(1);
- # Send the action to the main process and put it into
- # the queue.
- if (@action) {
- # Lock the queue.
- lock($queue);
+ # 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);
- # Put the required action into the queue.
- $queue->enqueue(@action);
+ # If the parser returns to perform an action,
+ # add it to the main event queue.
+ if ($action) {
+ # Lock the queue.
+ lock($queue);
+
+ # Enqueue the returned action.
+ $queue->enqueue($action);
+ }
}
}
}
#
-## Function for fileposition initialization.
+## Function for capturing process signals.
#
-## This function is used to get the cursor position of the end of file (EOF) of
-## a specified file.
+## This function captures any sent process signals and will call various
+## actions, basend on the captured signal.
#
-## In order to prevent from permanently read and keep files opened, or dealing
-## with huge logfiles, at initialization time of the worker processes, the file will
-## be opened once and the cursor position of the end of file (EOF) get stored.
+sub SignalHandler {
+ $SIG{INT} = \&Shutdown;
+ $SIG{TERM} = \&Shutdown;
+ $SIG{QUIT} = \&Shutdown;
+ $SIG{HUP} = \&Reload;
+}
+
#
-sub Init_fileposition ($) {
- my $file = $_[0];
+## 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...");
- # Open the file.
- open(FILE, $file) or die "Could not open $file. $!\n";
+ # Stop all running workers.
+ &StopWorkers();
- # Just seek to the end of the file (EOF).
- seek(FILE, 0, 2);
+ # Re-read configuration file.
+ %mainsettings = &Guardian::Config::UseConfig($cmdargs{"config"});
- # Get and store the position.
- my $position = tell(FILE),
+ # Update Logger settings.
+ $logger = Guardian::Logger->Update(%mainsettings);
+
+ # Update logger object in mainsettings hash.
+ $mainsettings{Logger} = $logger;
+
+ # 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);
- # Close the file again.
- close(FILE);
+ # Log good bye message.
+ $logger->Log("debug", "Good Bye!");
- # Return the position.
- return $position;
+ # Exit guardian.
+ exit;
}
projects / people / stevee / guardian.git / blobdiff