#!/usr/local/perl -w

use strict;
use warnings;
use diagnostics;
use Net::SMTP;
use File::Tail;


our $logfile=("/pix/pix.log");		# PIX Log File
our $criticallog=("/pix/critical_log");	# Critical Message Log File
our $datestamp;					# Global Time Variables
our $timestamp;
our $readline;					# File::Tail Working Variable
our $maxlogsize=("10000000");			# Max Log Size (bytes)
our $emailpriority;				# E-Mail Priority for Paging
our $messagebody;					# Text Of E-Mail Alert
our $size;						# Current Log File Size

# main
{
   # Process PIX Log File in infinite loop of tail checking
	# Start 'Tailing' the log file for changes
	my $workingfile=File::Tail->new(name=>$logfile,
					maxinterval=>30,
					adjustafter=>5,
					maxbuf=>16384);
	# Evaluation Loop - NOTE: Activates only on changes to logfile
	while (defined($readline=$workingfile->read))
	{
		# Sets evaluation parsing to look for ACTIVE and Down
		# ACTIVE - triggered on firewall failover
		# Down - triggered on interface shutdown or failure
		if (($readline=~/ACTIVE/) || ($readline=~/Down/))
		{
			TimeStamping ($datestamp,$timestamp);
			$messagebody=("$readline");
			$emailpriority=("2");
			EMailAlert ($datestamp,$timestamp,
					$messagebody,$emailpriority);
			CriticalLogging ($datestamp,$timestamp,$readline);
		}
		# Evaluate the log size against established maximum
		(my $dev,my $ino,my $mode,my $nlink,my $uid,my $gid,
			my $rdev,$size,my $atime,my $mtime,my $ctime,
			my $blksize,my $blocks)=stat($logfile);
		if ($size>$maxlogsize)
		{
			LogRollover ($size);
			$workingfile=File::Tail->new(name=>$logfile,
						maxinterval=>30,
						adjustafter=>5,
						maxbuf=>16384);
		}
		# Signal handlers for an attempted clean exit
		$SIG{INT}=\&CleanExit;
		$SIG{QUIT}=\&CleanExit;
		$SIG{ABRT}=\&CleanExit;
		$SIG{TERM}=\&CleanExit;
	}
}
exit;


sub TimeStamping
{
   # Dynamically assigns a human readable date/time variable for stamping
	(my $sec, my $min, my $hour, my $day, my $mon, my $year)
		=localtime(time);
	$year=sprintf("%04d",($year+1900));		# Year correction
	$mon=sprintf("%02d",($mon+1));		# Month correction
	$day=sprintf("%02d",$day);
	$hour=sprintf("%02d",$hour);
	$min=sprintf("%02d",$min);
	$sec=sprintf("%02d",$sec);
	$datestamp=("$year-$mon-$day");		# Friendly file date
	$timestamp=("$hour:$min:$sec");		# Friendly file time
}


sub LogRollover
{
   # Rollover of logs to an archived datestamped file
	TimeStamping ($datestamp,$timestamp);
	my $archivename=("pix.$datestamp.$timestamp.archive");
	rename "/pix/pix.log","/pix/pix.$datestamp.$timestamp.archive";
	system "/etc/init.d/syslog restart";	# Restart Syslogd
	$messagebody=("Log at: $size/n Archived to: $archivename");
	$emailpriority=("1");				# Low Priority
	EMailAlert ($messagebody,$emailpriority);
}


sub EMailAlert
{
   # E-Mail or Page the Administrator of critical alerts and failures

   # SMTP Relay Server Information
	my $smtp=Net::SMTP->new('mail.<somedomain>.com'
				, Hello => '<somedomain>.com'
				, Timeout => 60,
				, Debug => 0,
				);


	$smtp->mail( "" );
	# Evaluate priority for alphanumeric paging
	if ($emailpriority=="2")
	{
		$smtp->to("<phonenumber>\@<some>wireless.net");
	}
	$smtp->to("<administrator-type>\@<somedomain>.com");
	$smtp->data();
	$smtp->datasend("From: PIX Syslog Parser\n");
	$smtp->datasend("Subject: PIX Alert Notification\n");
	$smtp->datasend("To: Network Administrator\n");
	$smtp->datasend("BCC: \n");
	$smtp->datasend("\n");
	$smtp->datasend("Alert: $datestamp $timestamp\n");
	$smtp->datasend("\n");
	$smtp->datasend("$messagebody\n");
	$smtp->datasend("\n");
	$smtp->dataend();
	$smtp->quit();
	$emailpriority=("1");
}


sub CriticalLogging
{
   # Writes critical notifications to seperate log file
	open (CRITICALLOGFILE, ">>$criticallog")
		or die "Unable to write critical notification to file\n";
	print CRITICALLOGFILE "$datestamp  $timestamp\n";
	print CRITICALLOGFILE "$readline\n";
	close (CRITICALLOGFILE);
}


sub CleanExit
{
   # Subroutine for a clean exit from script
	close (CRITICALLOGFILE);
	close ($logfile);
	print ("Terminating Script\n");
	exit;
}