#!/usr/bin/perl
#
#
# AUTHORS:
#	Copyright (C) 2003-2010 Opsera 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
#
#    Patched by M. Schoemaker/Shoenix for Thomson Modems

use lib qw ( /usr/local/nagios/perl/lib );
use Net::SNMP;
use Getopt::Std;

$script         = "check_snmp_interfaces";
$script_version = "2.1shoenix";

# SNMP options
$version = "2c";
$timeout = 2;

# $metric = 1;
$firsttime        = 0;
$change           = 0;
$error            = 0;
$interfacesup     = 0;
$interfacesdown   = 0;
@currentstatus    = ();
@previousstatus   = ();
$oid_sysDescr     = ".1.3.6.1.2.1.1.1.0";
$ifdescr          = ".1.3.6.1.2.1.2.2.1.2.1";
$baseifdescr      = ".1.3.6.1.2.1.2.2.1.2";
$ifoperstatus     = ".1.3.6.1.2.1.2.2.1.8";
$baseifoperstatus = ".1.3.6.1.2.1.2.2.1.8";
$hostname         = "192.168.10.21";
my $port = 161;

#$hostname = "212.113.28.134";
$returnstring = "";

$community      = "public";                  # Default community string
$configfilepath = "/usr/local/nagios/etc";
$firsttime      = 0;

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

getopts("hH:C:p:");
if ($opt_h) {
    usage();
    exit(0);
}
if ($opt_H) {
    $hostname = $opt_H;

    # print "Hostname $opt_H\n";
}
else {
    print "No hostname specified\n";
    usage();
    exit(0);
}
if ($opt_C) {
    $community = $opt_C;

    # print "Using community $opt_C\n";
}
else {

    # print "Using community $community\n";
}
if ($opt_p) {
    $port = $opt_p;
}

$statusfile = "/usr/local/nagios/var/status_$hostname.db";
readstatus();

# Create the SNMP session

$version = "1";
( $s, $e ) = Net::SNMP->session(
    -community => $community,
    -hostname  => $hostname,
    -version   => $version,
    -timeout   => $timeout,
    -port      => $port,
);

if ( !defined( $s->get_request($oid_sysDescr) ) ) {

    # If we can't connect using SNMPv1 lets try as SNMPv2
    $s->close();
    sleep 0.5;
    $version = "2c";
    ( $s, $e ) = Net::SNMP->session(
        -community => $community,
        -hostname  => $hostname,
        -version   => $version,
        -timeout   => $timeout,
    );
    if ( !defined( $s->get_request($oid_sysDescr) ) ) {
        print "Agent not responding, tried SNMP v1 and v2\n";
        exit(1);
    }
}

# Works out what type of device we are looking at
# and chances the OID if necessary

if ( !defined( $s->get_request(".1.3.6.1.2.1.1.1.0") ) ) {
    if ( !defined( $s->get_request($oid_sysDescr) ) ) {
        print "Status is a Warning Level - SNMP agent not responding\n";
        exit 1;
    }
    else {
        print "Status is a Warning Level - SNMP OID does not exist\n";
        exit 1;
    }
}
else {
    foreach ( $s->var_bind_names() ) {
        $oid      = $_;
        $sysdescr = $s->var_bind_list()->{$oid};
    }
}
if ( $sysdescr =~ /3Com/ ) {
    $ifdescr = ".1.3.6.1.2.1.2.2.1.2.101";
}

# This devices starts interfaces at a different location
if ( $sysdescr =~ /Catalyst 4500 L3 Switch/ ) {
    $ifdescr = ".1.3.6.1.2.1.2.2.1.2.2";
}

if ( $sysdescr =~ /ST780/ ) {
     $ifdescr = ".1.3.6.1.2.1.2.2.1.2.101";
}

if ( $sysdescr =~ /SpeedTouch 716/ ) {
     $ifdescr = ".1.3.6.1.2.1.2.2.1.2.101";
}

# Scans interfaces

$counter = 0;
while ( $ifdescr =~ /$baseifdescr/ ) {
    if ( !defined( $s->get_request($ifdescr) ) ) {
        if ( !defined( $s->get_request($oid_sysDescr) ) ) {
            print "SNMP agent not responding\n";
            exit 1;
        }
        else {
            print "SNMP OID does not exist\n";
            exit 1;
        }
    }
    else {
        foreach ( $s->var_bind_names() ) {
            $oid = $_;

            # print "$oid\n";
            $interfacedescr = $s->var_bind_list()->{$oid};

            # print "Interface: $interfacedescr\n";
            $oid =~ s/$baseifdescr//g;    # removes base oid from string
            $ifoperstatus = "$baseifoperstatus$oid";

            # print "$baseifoperstatus\n$ifoperstatus\n";
        }
    }

    if ( !defined( $s->get_request($ifoperstatus) ) ) {
        if ( !defined( $s->get_request($oid_sysDescr) ) ) {
            print("SNMP agent not responding");
            exit 1;
        }
        else {
            print "SNMP OID does not exist";
            exit 1;
        }
    }
    else {
        foreach ( $s->var_bind_names() ) {
            $oid    = $_;
            $status = $s->var_bind_list()->{$oid};
            push( @currentstatus, $status );
            if ( $status == 1 ) {
                $interfacesup++;
            }
            else {
                $interfacesdown++;
            }

            if ( $status == @previousstatus[$counter] ) {
            }
            else {
                if ( $status < @previousstatus[$counter] ) {
                    append("$interfacedescr now UP ");
                    $change = 1;
                }
                else {
                    append("$interfacedescr DOWN! ");
                    $change = 1;
                }
            }

            # print "Current=$status\nPrevious=@previousstatus[$counter]";
        }
    }

    if ( !defined( $s->get_next_request($ifdescr) ) ) {
        exit 1;
    }
    else {
        foreach ( $s->var_bind_names() ) {
            $ifdescr = $_;
        }
    }
    $counter++;
}

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

writestatus();

if ( $firsttime == 1 ) {
    $change = 0;
}
if ( error == 0 ) {
    if ( $change == 0 ) {
        print "Status is OK - Interfaces: $interfacesup UP, $interfacesdown DOWN|in_use=$interfacesup\n";
        exit 0;
    }
    elsif ( $change == 1 ) {
        print "Status is a Warning Level - $returnstring |in_use=$interfacesup\n";
        exit 1;
    }
    else {
        print "Plugin error! SNMP status unknown\n";
        exit 1;
    }
}
else {
    print "Status is Warning Level - $returnstring |in_use=$interfacesup\n";
    exit 1;
}

exit 0;

sub readstatus {
    if ( -e "$statusfile" ) {
        open STATUSFILE, "<$statusfile" or die "Can't open file $statusfile: $1";
        @previousstatus = <STATUSFILE>;
        close STATUSFILE;
    }
    else {
        $firsttime = 1;
    }
}

sub writestatus {
    open STATUSFILE, ">$statusfile" or die "Can't open file $statusfile: $1";
    foreach $line (@currentstatus) {
        print STATUSFILE "$line\n";
    }
    close STATUSFILE;
}

sub append {
    my $appendstring = @_[0];
    $returnstring = "$returnstring$appendstring";
}

sub usage {
    print << "USAGE";

$script v$script_version

Tracks status of Ethernet interfaces. Patched for Speedtouch/Thomson
modems.

Usage: $script -H <hostname> -c <community> [...]
Options: -H 		Hostname or IP address
         -C 		Community (default is public)
         -p 		Port (default: 161)
USAGE
    exit 1;
}