#!/usr/bin/perl

use strict;
use Net::SNMP;
use Getopt::Long;

my %opt;
GetOptions( "host=s" => \$opt{'host'},
				"community=s" => \$opt{'community'},
				"warn=i" => \$opt{'warn'},
				"crit=i" => \$opt{'crit'});

unless ($opt{'host'} && $opt{'community'} && $opt{'warn'} && $opt{'crit'}) {
	print "Usage: $0 --host <hostname> --community <community> --warn <percent> --crit <percent>\n\n";
	exit 1;
}

my $oid_mem_used_5min = "1.3.6.1.4.1.9.9.48.1.1.1.5.1";
my $oid_mem_free_5min = "1.3.6.1.4.1.9.9.48.1.1.1.6.1";

my($session, $error) = Net::SNMP->session(-hostname => $opt{'host'},
														-community => $opt{'community'} );
unless(defined($session)) {
	print "Critical - Could not establish SNMP session\n";
	exit 3;
}


my $result = $session->get_request(-varbindlist => [$oid_mem_used_5min,$oid_mem_free_5min] );

my $mem_free = $result->{$oid_mem_free_5min};
my $mem_used = $result->{$oid_mem_used_5min};
my $mem_total = $mem_free + $mem_used; 
my $mem_used_percent = int(100 * ($mem_used / $mem_total));
my $mem_free_percent = int(100 * ($mem_free / $mem_total));

$session->close;

print "Used: ".$mem_used."/".$mem_used_percent."% Free: ".$mem_free."/".$mem_free_percent."% Total: ".$mem_total."\n";

exit 2 if $mem_used_percent > $opt{'crit'};
exit 1 if $mem_used_percent > $opt{'warn'};
exit 0;