#!/usr/bin/perl
#
#
# AUTHORS:
#	Copyright (C) 2003-2012 Opsview Limited. All rights reserved
#
#    This file is part of Opsview
#
#    Opsview 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 2 of the License, or
#    (at your option) any later version.
#
#    Opsview 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 Opsview; if not, write to the Free Software
#    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
# MODIFIED:
#    July 25, 2012 by Patrik Dufresne. Take the buffered and chaced value in
#    consideration
use lib qw ( /usr/local/nagios/perl/lib );
use Net::SNMP;
use Getopt::Std;

use warnings;
use strict;

my $script         = 'check_snmp_memutil';
my $script_version = '3.0';

my $metric        = 1;
my $oid_sysDescr  = ".1.3.6.1.2.1.1.1.0";
my $memTotalSwap  = ".1.3.6.1.4.1.2021.4.3.0";
my $memTotalReal  = ".1.3.6.1.4.1.2021.4.5.0";
my $memAvailSwap  = ".1.3.6.1.4.1.2021.4.4.0";
my $memAvailReal  = ".1.3.6.1.4.1.2021.4.6.0";
my $memCached     = ".1.3.6.1.4.1.2021.4.15.0";
my $memBuffered   = ".1.3.6.1.4.1.2021.4.14.0";
my $version       = "1";
my $timeout       = 2;
my $real_warning  = 90;
my $real_critical = 95;
my $swap_warning  = 90;
my $swap_critical = 95;
my $status        = 0;
my $returnstring  = "";
my $port          = 161;
my $hostname;
my $community = "public";    # Default community string

# SNMP values
my $availreal          = 0;
my $availswap          = 0;
my $totalmemused       = 0;
my $totalreal          = 0;
my $totalrealmb        = 0;
my $totalswap          = 0;
my $totalswapmb        = 0;
my $usedreal           = 0;
my $usedrealmb         = 0;
my $usedrealpercentage = 0;
my $usedswap           = 0;
my $usedswapmb         = 0;
my $usedswappercentage = 0;
my $buffered           = 0;
my $bufferedmb         = 0;
my $cached             = 0;
my $cachedmb           = 0;

# Do we have enough information?
if ( @ARGV < 1 ) {
    print "Too few arguments$/";
    usage();
}

our ( $opt_h, $opt_H, $opt_C, $opt_w, $opt_c, $opt_x, $opt_d, $opt_p, $opt_v );
getopts("hH:C:w:c:x:d:p:v:");
if ($opt_h) {
    usage();
    exit(0);
}
if ($opt_H) {
    $hostname = $opt_H;
}
else {
    print "No hostname specified$/";
    usage();
}
if ($opt_C) {
    $community = $opt_C;
}
if ($opt_w) {
    $real_warning = $opt_w;
    $real_warning =~ s/%//g;
}
if ($opt_c) {
    $real_critical = $opt_c;
    $real_critical =~ s/%//g;
}
if ($opt_x) {
    $swap_warning = $opt_x;
    $swap_warning =~ s/%//g;
}
if ($opt_d) {
    $swap_critical = $opt_d;
    $swap_critical =~ s/%//g;
}
if ($opt_p) {
    $port = $opt_p;
}
if ($opt_v) {
    if ( $opt_v ne "1" && $opt_v ne "2c" ) {
        print "SNMP version must be 1 or 2c (not $opt_v)$/";
        usage();
    }
    else {
        $version = $opt_v;
    }
}

# Create the SNMP session
my ( $s, $e ) = Net::SNMP->session(
    -community => $community,
    -hostname  => $hostname,
    -version   => $version,
    -timeout   => $timeout,
    -port      => $port,
);

main();

# Close the session
$s->close();

if ( $returnstring eq "" ) {
    $status = 3;
}

if ( $status == 0 ) {
    print "OK - $returnstring$/";
}
elsif ( $status == 1 ) {
    print "WARNING - $returnstring$/";
}
elsif ( $status == 2 ) {
    print "CRITICAL - $returnstring$/";
}
else {
    print "UNKNOWN - Plugin error?$/";
}

exit $status;

sub main {

    # Swap
    if ( !defined( $s->get_request($memTotalSwap) ) ) {
        if ( !defined( $s->get_request($oid_sysDescr) ) ) {
            $returnstring = "SNMP agent not responding";
            $status       = 1;
            return 1;
        }
        else {
            $returnstring = "SNMP OID does not exist";
            $status       = 1;
            return 1;
        }
    }
    foreach ( $s->var_bind_names() ) {
        $totalswap = $s->var_bind_list()->{$_};
    }

    if ( !defined( $s->get_request($memAvailSwap) ) ) {
        if ( !defined( $s->get_request($oid_sysDescr) ) ) {
            $returnstring = "SNMP agent not responding";
            $status       = 1;
            return 1;
        }
        else {
            $returnstring = "SNMP OID does not exist";
            $status       = 1;
            return 1;
        }
    }
    foreach ( $s->var_bind_names() ) {
        $availswap = $s->var_bind_list()->{$_};
    }
    $usedswap           = $totalswap - $availswap;
    if( $totalswap > 0 ) {
        $usedswappercentage = ( 100 / $totalswap ) * $usedswap;
    }
    $usedswapmb         = $usedswap / 1024;

    # printf "Swap memory used: %.0f percent (%.0f Mb)$/", $usedswappercentage, $usedswapmb ;

    # Real
    if ( !defined( $s->get_request($memTotalReal) ) ) {
        if ( !defined( $s->get_request($oid_sysDescr) ) ) {
            $returnstring = "SNMP agent not responding";
            $status       = 1;
            return 1;
        }
        else {
            $returnstring = "SNMP OID does not exist";
            $status       = 1;
            return 1;
        }
    }
    foreach ( $s->var_bind_names() ) {
        $totalreal = $s->var_bind_list()->{$_};

        # $totalreal = sprintf("%.2f",$totalreal);
    }

    if ( !defined( $s->get_request($memAvailReal) ) ) {
        if ( !defined( $s->get_request($oid_sysDescr) ) ) {
            $returnstring = "SNMP agent not responding";
            $status       = 1;
            return 1;
        }
        else {
            $returnstring = "SNMP OID does not exist";
            $status       = 1;
            return 1;
        }
    }
    foreach ( $s->var_bind_names() ) {
        $availreal = $s->var_bind_list()->{$_};

        # $availreal = sprintf("%.2f",$availreal);
    }

    # Buffered
    if ( !defined( $s->get_request($memBuffered) ) ) {
        if ( !defined( $s->get_request($oid_sysDescr) ) ) {
            $returnstring = "SNMP agent not responding";
            $status       = 1;
            return 1;
        }
        else {
            $returnstring = "SNMP OID does not exist";
            $status       = 1;
            return 1;
        }
    }
    foreach ( $s->var_bind_names() ) {
        $buffered = $s->var_bind_list()->{$_};

        # $availreal = sprintf("%.2f",$availreal);
    }

    # Cached
    if ( !defined( $s->get_request($memCached) ) ) {
        if ( !defined( $s->get_request($oid_sysDescr) ) ) {
            $returnstring = "SNMP agent not responding";
            $status       = 1;
            return 1;
        }
        else {
            $returnstring = "SNMP OID does not exist";
            $status       = 1;
            return 1;
        }
    }
    foreach ( $s->var_bind_names() ) {
        $cached = $s->var_bind_list()->{$_};

        # $availreal = sprintf("%.2f",$availreal);
    }

    $totalrealmb        = $totalreal / 1024;
    $totalswapmb        = $totalswap / 1024;
    $usedreal           = $totalreal - ( $cached + $buffered + $availreal);
    $usedrealpercentage = ( 100 / $totalreal ) * $usedreal;
    $usedrealmb         = $usedreal / 1024;
    $cachedmb           = $cached / 1024;
    $bufferedmb         = $buffered / 1024;

    $totalmemused = $usedrealpercentage + $usedswappercentage;

    $returnstring .= sprintf "USAGE: real %.0f%% (%.0f/%.0fMB), buffer: %.0fMB, cache: %.0fMB, swap %.0f%% (%.0f/%.0f MB)|", $usedrealpercentage, $usedrealmb, $totalrealmb, $bufferedmb, $cachedmb, $usedswappercentage, $usedswapmb, $totalswapmb;

    # Perf data
    $returnstring .= sprintf "used_real_pct=%.0f%% used_real_mb=%.0f used_swap_pct=%.0f%% used_swap_mb=%.0f cached_mb=%.0f buffered_mb=%.0f", $usedrealpercentage, $usedrealmb, $usedswappercentage, $usedswapmb, $cachedmb, $bufferedmb;

    if ( $usedrealpercentage >= $real_critical ) {
        $status = 2;
    }
    elsif ( $usedswappercentage >= $swap_critical ) {
        $status = 2;
    }
    elsif ( $usedrealpercentage >= $real_warning ) {
        $status = 1;
    }
    elsif ( $usedswappercentage >= $swap_warning ) {
        $status = 1;
    }
    else {
        $status = 0;
    }
}

sub usage {
    print << "USAGE";

$script v$script_version

Returns memory utilisation stats for Linux / Unix systems

Usage: $script -H <hostname> -C <community> [...]
Options: -H 		Hostname or IP address
         -p 		Port (default: 161)
         -C 		Community (default is public)
         -w 		Real memory warning threshold (as % used)
         -c 		Real memory critical threshold (as % used)
         -x 		Swap warning threshold (as % used)
         -d 		Swap critical threshold (as % used)
USAGE
    exit 3;
}