[Nagiosplug-help] mod to check_ifstatus

[Austad, Jay]

I made some mods to check_ifstatus.  The first mod makes it ignore BRI
subinterfaces that are down and changes their state to dormant.  Not all of
my BRI's are dialed up all the time, but it will still detect if the ISDN
line is not physically working.

The second mod adds the -i option.  The -i lets you ignore certain
interfaces that need to not be administratively shutdown, but are down
because you have an external ISDN device or something else that is not
always in use.  External ISDN devices connected via serial links to the
router are a good example of these.  

I didn't update the usage message or anything, and I didn't do a diff to
supply the patch.  If someone wants to do it on the code below, feel free.
I'm no programmer, so the code may suck, but it works.  Maybe someone with
more skill wants to clean it up and roll it in with the release if they find
it useful.

Example:
./check_ifstatus -C public -H 10.1.1.1 -i Serial8/0 -i Serial11/0/2 -i
Serial3/0

I guess the code that specifically removes the BRI subinterfaces could be
taken out and just done on the command line, but I have a ton of routers
with all different numbering, so this would be a pain for me.  

Jay Austad

#! /usr/bin/perl -w
#
# check_ifstatus.pl - nagios plugin 
# 
#
# Copyright (C) 2000 Christoph Kron
# Modified 5/2002 to conform to updated Nagios Plugin Guidelines (S. Ghosh)
#
# This program 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.
#
# This program 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 this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
USA.
#
#
# Report bugs to: ck at zet.net, nagiosplug-help at lists.sf.net
# 
# 11.01.2000 Version 1.0
#
# $Id: check_ifstatus.pl,v 1.1 2002/05/08 04:58:22 sghosh Exp $

#use POSIX;
use strict;
use lib "/usr/local/libexec/nagios" ;
use utils qw($TIMEOUT %ERRORS &print_revision &support);

use Net::SNMP;
use Getopt::Long;
Getopt::Long::Configure('bundling');

my $PROGNAME = "check_ifstatus";


my $status;
my %ifOperStatus = 	('1','up',
			 '2','down',
			 '3','testing',
			 '4','unknown',
			 '5','dormant',
			 '6','notPresent');

my $state = "UNKNOWN";
my $answer = "";
my $snmpkey=0;
my $snmpoid=0;
my $key=0;
my $community = "public";
my $port = 161;
my @snmpoids;
my $snmpIfAdminStatus = '1.3.6.1.2.1.2.2.1.7';
my $snmpIfDescr = '1.3.6.1.2.1.2.2.1.2';
my $snmpIfOperStatus = '1.3.6.1.2.1.2.2.1.8';
my $snmpIfName = '1.3.6.1.2.1.31.1.1.1.1';
my $snmpIfAlias = '1.3.6.1.2.1.31.1.1.1.18';
my $snmpLocIfDescr = '1.3.6.1.4.1.9.2.2.1.1.28';
my $hostname;
my $session;
my $error;
my $response;
my %ifStatus;
my $ifup =0 ;
my $ifdown =0;
my $ifdormant = 0;
my $ifmessage = "";
my $snmp_version = 1;
my $ifXTable;
my $opt_h ;
my $opt_V ;
my @ignorelist;
my $ignore;





# Just in case of problems, let's not hang Nagios
$SIG{'ALRM'} = sub {
     print ("ERROR: No snmp response from $hostname (alarm timeout)\n");
     exit $ERRORS{"UNKNOWN"};
};
alarm($TIMEOUT);



#Option checking
$status = GetOptions(
		"V"   => \$opt_V, "version"    => \$opt_V,
		"h"   => \$opt_h, "help"       => \$opt_h,
		"v=i" => \$snmp_version, "snmp_version=i"  =>
\$snmp_version,
		"C=s" =>\$community,"community=s" => \$community,
		"p=i" =>\$port, "port=i" => \$port,
		"H=s" => \$hostname, "hostname=s" => \$hostname,
		"I"	  => \$ifXTable, "ifmib" => \$ifXTable ,
		"i=s"	=> \@ignorelist );
		
if ($status == 0)
{
	print_help() ;
	exit $ERRORS{'OK'};
}


if ($opt_V) {
	print_revision($PROGNAME,'$Revision: 1.1 $ ');
	exit $ERRORS{'OK'};
}

if ($opt_h) {
	print_help();
	exit $ERRORS{'OK'};
}

if (! utils::is_hostname($hostname)){
	usage();
	exit $ERRORS{"UNKNOWN"};
}

if ( ! $snmp_version ) {
	$snmp_version =1 ;
}else{
	if ( $snmp_version =~ /[12]/ ) {
			
		($session, $error) = Net::SNMP->session(
		      -hostname  => $hostname,
		      -community => $community,
		      -port      => $port,
			  -version	=> $snmp_version
			   );

		if (!defined($session)) {
		      $state='UNKNOWN';
		      $answer=$error;
		      print ("$state: $answer");
		      exit $ERRORS{$state};
		}

		
	}elsif ( $snmp_version =~ /3/ ) {
		$state='UNKNOWN';
		print ("$state: No support for SNMP v3 yet\n");
		exit $ERRORS{$state};
	}else{
		$state='UNKNOWN';
		print ("$state: No support for SNMP v$snmp_version yet\n");
		exit $ERRORS{$state};
	}
}



push(@snmpoids,$snmpIfOperStatus);
push(@snmpoids,$snmpIfAdminStatus);
push(@snmpoids,$snmpIfDescr);
push(@snmpoids,$snmpIfAlias);
push(@snmpoids,$snmpIfName) if ( defined $ifXTable);



foreach $snmpoid (@snmpoids) {

   if (!defined($response = $session->get_table($snmpoid))) {
      $answer=$session->error;
      $session->close;
      $state = 'CRITICAL';
      print ("$state: $answer for $snmpoid  with snmp version
$snmp_version\n");
      exit $ERRORS{$state};
   }

   foreach $snmpkey (keys %{$response}) {
      $snmpkey =~ /.*\.(\d+)$/;
      $key = $1;
      $ifStatus{$key}{$snmpoid} = $response->{$snmpkey};
   }
}


$session->close;

foreach $key (keys %ifStatus) {

	# check only if interface is administratively up
    if ($ifStatus{$key}{$snmpIfAdminStatus} == 1 ) {
	foreach $ignore (@ignorelist) {
		if($ifStatus{$key}{$snmpIfDescr}=~/^$ignore$/) {
			$ifStatus{$key}{$snmpIfOperStatus} = 5;
		}
	}
    	if ($ifStatus{$key}{$snmpIfOperStatus} == 1 ) { $ifup++ ;}
        if ($ifStatus{$key}{$snmpIfOperStatus} == 2 ) {
		if($ifStatus{$key}{$snmpIfDescr}!~/BRI.+:[12]/) {
             $ifdown++ ;
             $ifmessage .= sprintf("%s: down -> %s<BR>",
$ifStatus{$key}{$snmpIfDescr}, $ifStatus{$key}{$snmpIfAlias});
			}
			else {
				$ifStatus{$key}{$snmpIfOperStatus} = 5;
			}
         	}
         if ($ifStatus{$key}{$snmpIfOperStatus} == 5 ) { $ifdormant++ ;}
      }
   }
   

   if ($ifdown > 0) {
      $state = 'CRITICAL';
      $answer = sprintf("host '%s', interfaces up: %d, down: %d, dormant:
%d<BR>",
                        $hostname,
			$ifup,
			$ifdown,
			$ifdormant);
      $answer = $answer . $ifmessage . "\n";
   }
   else {
      $state = 'OK';
      $answer = sprintf("host '%s', interfaces up: %d, down: %d, dormant:
%d\n",
                        $hostname,
			$ifup,
			$ifdown,
			$ifdormant);
   }

print ("$state: $answer");
exit $ERRORS{$state};


sub usage {
	printf "\nMissing arguments!\n";
	printf "\n";
	printf "check_ifstatus -C <READCOMMUNITY> -p <PORT> -H
<HOSTNAME>\n";
	printf "Copyright (C) 2000 Christoph Kron\n";
	printf "Updates 5/2002 Subhendu Ghosh\n";
	printf "\n\n";
	support();
	exit $ERRORS{"UNKNOWN"};
}

sub print_help {
	printf "check_ifstatus plugin for Nagios monitors operational \n";
  	printf "status of each network interface on the target host\n";
	printf "\nUsage:\n";
	printf "   -H (--hostname)   Hostname to query - (required)\n";
	printf "   -C (--community)  SNMP read community (defaults to
public,\n";
	printf "                     used with SNMP v1 and v2c\n";
	printf "   -v (--snmp_version)  1 for SNMP v1 (default)\n";
	printf "                        2 for SNMP v2c\n";
	printf "                        SNMP v2c will use get_bulk for less
overhead\n";
	printf "   -p (--port)       SNMP port (default 161)\n";
	printf "   -I (--ifmib)      Agent supports IFMIB ifXTable.  Do not
use if\n";
	printf "                     you don't know what this is.\n";
	printf "   -V (--version)    Plugin version\n";
	printf "   -h (--help)       usage help \n\n";
	print_revision($PROGNAME, '$Revision: 1.1 $');
	
}