#!/usr/bin/perl -w
use strict;

use Net::SNMP qw(ticks_to_time);
use GD::Graph::lines;
use GD::Graph::colour;

use constant HOUR_IN_SECS => 3600;

my ($session, $error, $response, $run, $time, $upTime);
my (@utilizationRec, @utilizationOut, @runTimes);
my ($octetOutUtil, $octetInUtil, @timeSamples);

# Change these to match your needs
# --------------------------------------------

my $host      = "IP_ADDRESS";		# The host we want to monitor
my $hostname  = "SERVERNAME";		# its fancy netbios name
my $community = "public";		# The community name to read from
my $ifSpeed   = "IFSPEED";		# The speed of your interface

my $numRuns   = 108;			# +$pauseTime+$sleepTime dictates runtime length
my $pauseTime = 290;			# 5 minutes - total right now is set to one day	
my $sleepTime = 10;			# from 8am to 5pm

my $htmlFile  = "utilization.shtml";
my $runTime   = localtime;
my $runLength = ($pauseTime + $sleepTime) * $numRuns / HOUR_IN_SECS;

my $value     = 0;
my $recMax    = 0;
my $outMax    = 0;
my $outTotal  = 0;
my $recTotal  = 0;
my $recAvg    = 0;
my $outAvg    = 0;

# These are our specific SNMP OID's for 
# querying in and out octets and uptime
# --------------------------------------------

my @oids = ('1.3.6.1.2.1.2.2.1.10.16777219', '1.3.6.1.2.1.2.2.1.16.16777219', '1.3.6.1.2.1.1.3.0');

# This runs our SNMP get request so that I can
# populate our data for the graphs - calls the
# snmpRun() sub.
# --------------------------------------------

print "Begin data collection for $host - Runs: $numRuns\n";

for ($run = 1; $run <= $numRuns; $run++) {
	print "Starting run $run\\$numRuns - ";
	snmpRun();
	unless ($run == $numRuns) { sleep("$pauseTime"); }
}


# Now that our data is nicely entered into
# our arrays, we can plot our graphs out
# -------------------------------------------

createUtilGraph();
getAvgs();
upTime();
writeHTML();


sub snmpRun {
	# get the time

	use Time::localtime;
	my $tm = localtime;
	my ($hour, $min) = ($tm->hour, $tm->min);
	if ($min =~ /^\d$/) {
		$min = "0$min";
		$time = "$hour:$min";
	} else {
		$time = "$hour:$min";
	}


	# Run number 1
	# --------------------------------------

	($session, $error) = Net::SNMP->session(
	   -hostname	=>	$host,
	   -community	=>	$community,
	   -port	=>	161,
	   -version	=>	"2c",
	   -translate	=>	[ -timeticks => 0x0 ],
	);
	$session or die "Session error: $error\n";

	$response = $session->get_request(@oids);
	$response or die "Response error:" . "$session->error()" . "\n";

	$session->hostname();

	my $bytesIn   = $response->{'1.3.6.1.2.1.2.2.1.10.16777219'};
	my $bytesOut  = $response->{'1.3.6.1.2.1.2.2.1.16.16777219'};
	my $sysUpTime = $response->{'1.3.6.1.2.1.1.3.0'};
	
	$session->close();

	# Sleep till we go for the next run
	# --------------------------------------
	
	sleep("$sleepTime");

	# Run number 2
	# --------------------------------------

	($session, $error) = Net::SNMP->session(
	   -hostname	=>	$host,
	   -community	=>	$community,
	   -port	=>	161,
	   -version	=>	"2c",
	   -translate	=>	[ -timeticks => 0x0 ],
	);
	$session or die "Session error: $error\n";

	$response = $session->get_request(@oids);
	$response or die "Response error:" . "$session->error()" . "\n";

	$session->hostname();

	my $bytesIn2   = $response->{'1.3.6.1.2.1.2.2.1.10.16777219'};
	my $bytesOut2  = $response->{'1.3.6.1.2.1.2.2.1.16.16777219'};
	my $sysUpTime2 = $response->{'1.3.6.1.2.1.1.3.0'};
	
	$session->close();

	# Data is collected, now do our calculation
	# Delta(octetType) * 8
	# --- => octetType Utilization
	# Delta(sysUpTime)*10000
	# -----------------------------------------
	
	my $bytesInDiff   = $bytesIn2   - $bytesIn;
	my $bytesOutDiff  = $bytesOut2  - $bytesOut;
	my $sysUpTimeDiff = $sysUpTime2 - $sysUpTime;
	
	if ($bytesInDiff == 0) {
		$octetInUtil = "0.00";
	} else {
		my $octetInTemp  = ($bytesInDiff  * 8) / ($sysUpTimeDiff * $ifSpeed);
		$octetInTemp  =~ /(\d+)\.(\d\d)/;
		$octetInUtil = "$1.$2";
	}
	
	if ($bytesOutDiff == 0) {
		my $octetOutUtil = "0.00";
	} else {
		my $octetOutTemp = ($bytesOutDiff * 8) / ($sysUpTimeDiff * $ifSpeed);
		$octetOutTemp =~ /(\d+)\.(\d\d)/;
		$octetOutUtil = "$1.$2";
	}

	print "In: $octetInUtil Out: $octetOutUtil Time: $time\n";

	push( @utilizationRec, $octetInUtil );		# Push the data into our
	push( @utilizationOut, $octetOutUtil);		# arrays for use in our graphs
	push( @timeSamples, $time);			# Push the time from the run
}


sub createUtilGraph {
	my @outData = ( [ (@timeSamples) ], [ (@utilizationOut) ] );
	my @recData = ( [ (@timeSamples) ], [ (@utilizationRec) ] );
	
	my $graph = GD::Graph::lines->new(650,200);

	$graph->set(
		r_margin	=>	'4',
		title		=>	'Ethernet Utilization',
		x_label		=>	'Time (5 minute intervals with a 10 second sample pause)',
		y_label		=>	'Utilization %',
		x_label_skip	=>	'12',
		tick_length	=>	'-4',
		y_max_value	=>	'100',
		y_min_value	=>	'0',
		transparent	=>	'1',
		interlaced	=>	'1',
		valuesclr	=>	'black',
		bgclr		=>	'white',
		fgclr		=>	'black',
		accentclr	=>	'black',
		shadowclr	=>	'dgreen',
		labelclr	=>	'black',
		axislabelclr	=>	'black',
		textclr		=>	'black',
		dclrs		=>	[ qw(green) ],
	);

	my $gd = $graph->plot( \@outData );
	
	$graph->set( dclrs => [ qw(red) ] );
	
	$gd = $graph->plot( \@recData );
	
	open(IMG, "+>UtilData.png") || die "Can't create object: ($!)\n";
	binmode IMG;
	print IMG $gd->png;
	close(IMG);
	print "Utilization Graph Completed - Run length: $runLength hours\n";
}


sub getAvgs {

	# Here we figure out some avg's and peaks
	# from our collected octet data
	# -------------------------------------------

	foreach $value (@utilizationRec) { 
		if ($value > $recMax) { 
			$recMax = $value; 
		}
		$recTotal += $value;	
	}

	foreach $value (@utilizationOut) { 
		if ($value > $outMax) { 
			$outMax = $value; 
		}
		$outTotal += $value;
	}

	my $recAvgTemp = $recTotal / $numRuns;
	my $outAvgTemp = $outTotal / $numRuns;

	$recAvgTemp =~ /(\d+)\.(\d\d)/;
	$recAvg = "$1.$2";

	$outAvgTemp =~ /(\d+)\.(\d\d)/;
	$outAvg = "$1.$2";

}

sub upTime {
	($session, $error) = Net::SNMP->session(
			-hostname	=>	$host,
			-community	=>	$community,
			-port		=>	161,
	);
	$session or die "Session error: $error\n";

	my $sysUpTime = '1.3.6.1.2.1.1.3.0';

	$response = $session->get_request($sysUpTime);
	$response or die "Response error:" . $session->error() . "\n";
	$session->hostname();
	$upTime = $response->{$sysUpTime};
	$session->close();
}

sub writeHTML {
	open(HTML, "+>$htmlFile") || die "Can't open file $htmlFile: ($!)\n";
	print HTML "<!--#include virtual=\"header.shtml\"-->\n";
	
	print HTML "<table border=\"0\" width=\"300\" cellspacing=\"2\">\n";
	print HTML "<tr><td class=\"framed\"><small>\n";
	print HTML "<table border=\"0\" cellpadding=\"0\" width=\"300\">\n";
	
	print HTML "<tr>\n";
	print HTML "<td align=\"right\"><small>Host:</small></td>\n";
	print HTML "<td align=\"right\"><b><small><b>$hostname ($host)</b></small></b></td>\n";
	print HTML "</tr>\n";
	print HTML "<tr>\n";
	print HTML "<td align=\"right\"><small>Last run time:</small></td>\n";
	print HTML "<td align=\"right\"><small><b>$runTime</b></small></td>\n";
	print HTML "</tr>\n";
	print HTML "<tr>\n";
	print HTML "<td align=\"right\"><small>System Uptime:</small></td>\n";
	print HTML "<td align=\"right\"><small><b>$upTime</b></small></td>\n";
	print HTML "</tr>\n";	
	print HTML "<tr>\n";
	print HTML "<td align=\"right\"><small>Received Max:</small></td>\n";
	print HTML "<td align=\"right\"><small><b>$recMax %</b></small></td>\n";
	print HTML "</tr>";
	print HTML "<tr>\n";
	print HTML "<td align=\"right\"><small>Outgoing Max:</small></td>\n";
	print HTML "<td align=\"right\"><small><b>$outMax %</b></small></td>\n";
	print HTML "</tr>";
	print HTML "<tr>\n";
	print HTML "<td align=\"right\"><small>Received Average:</small></td>\n";
	print HTML "<td align=\"right\"><small><b>$recAvg %</b></small></td>\n";
	print HTML "</tr>";
	print HTML "<tr>\n";
	print HTML "<td align=\"right\"><small>Outgoing Average:</small></td>\n";
	print HTML "<td align=\"right\"><small><b>$outAvg %</b></small></td>\n";
	print HTML "</tr>";
	
	print HTML "</table>\n";
	print HTML "</small></td></tr></table><br>\n";
	
	print HTML "<small>Incoming: <font color=\"red\"><b>Red</b></font></small><br>\n";
	print HTML "<small>Outgoing:</smal><font color=\"green\"><b>Green</b></font></small>\n";
	print HTML "<br><br>";
	
	print HTML "<table border=\"0\"><tr><td class=\"framed\">\n";
	print HTML "<img src=\"UtilData.png\" border=\"0\">\n";
	print HTML "</td></tr></table>\n";
	print HTML "<!--#include virtual=\"footer.shtml\"-->\n";
	close(HTML);
}

print "Generation complete.\n";