#!/usr/bin/perl

################################################################################
## 
## check_foundry_ports (version 0.9)
##
## Check port status against a list and return CRITICAL
## if result doesn't match definition. This may be a 
## indicator for a bad guy adding a device to our
## foundry devices.
##
################################################################################
##
## 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
##
################################################################################
##
## Port configurations:
## =====================
##
## Set the variable $port_base to your base directory containing the up/down
## definitions. The file(s) must match the supplied parameter "host". Here's a
## example entry:
##
## File    : /etc/nagios/cfg_dir/port_status/1.2.3.4
## Content : 1:[STATE RETURNED FROM SNMPGET]
##           2:[STATE RETURNED FROM SNMPGET]
##           9:[STATE RETURNED FROM SNMPGET]
##
## The value you must enter after the ":" differs in some Foundry models. So 
## please find it out yourself.
##
## Feel free to contact me if you have any problems regarding this plugin.
##
## ==> daniel@linuxaddicted.de
##
################################################################################

use strict;
use warnings;
use Getopt::Long;

#########################################################
### Global Vars
#########################################################

### Set the base directory for port definitions
###
### ====> You may need to change this variable
###
my $port_base = '/etc/nagios/cfg_dir/port_status';

### Initialize user-supplied vars
my ($host, $community, $port);

### Get the supplied vars
GetOptions('host=s' => \$host, 'community=s' => \$community, 'port=s' => \$port);


#########################################################
### Main App
#########################################################

PrintUsage() unless (( defined($host) ) || ( defined($community) ) || ( defined($port) ));

my $snmp_status = GetStatus();

#########################################################
### Subs / Functions
#########################################################

### Print script usage
sub PrintUsage
{
  print "\nUsage: check_foundry_ports [PARAMETERS]

Parameters:
            --host=[HOSTNAME]            : Hostname or IP-Address of Foundry device
	    --community=[SNMP COMMUNITY] : SNMP community string
	    --port=[INTERFACE NR]        : The interface number to check (1,2,3,22,...)\n\n";
 
  exit 2;
}

### Get SNMP status
sub GetStatus
{
  ### Get this SNMP party started
  my $result = `/usr/bin/snmpget -v1 -c $community $host ifOperStatus.$port 2>&1`;
  my $rc = $?>>8;

  if ( $rc != 0 )
  {
    PrintExit ("Error while running snmpget: $result");
  }
  else
  {
    $result = $1 if ($result =~ m/(\w+)\(.+\)/);

    my $return = CompareResultToList ($result);
    SelectOutput ($return);
  }
}

### Compare SNMP status to list
sub CompareResultToList
{
  ### Get the result from SNMP
  my $snmp_result = shift;
  my $line;

  ### Exit if there's no such list for host supplied
  PrintExit ("Unable to find corresponding list for $host!") unless ( -f "$port_base/$host" );

  ### Read the list
  open (LIST, "< $port_base/$host") || PrintExit ("Unable to open list $host: $!");
  while ( <LIST> )
  {
    if ( m/^$port\:.+/ )
    {
      $line = $_;
      last;
    }
  }
  close (LIST) || PrintExit ("Unable to close FH on $host: $!");

  ### Get dummy (forget that) and status from list
  my ($dummy, $list_result) = split(/:/, $line);
  chomp($list_result);
  $dummy = '';

  if ( $snmp_result eq $list_result )
  {
    print "OK: Port $port is $snmp_result (as defined in list)";
    exit 0;
  }
  else
  {
    print "CRIT: Port $port is ", uc($snmp_result), " (!! NOT as defined in list !!)";
    exit 2;
  }
}

## Print message and die
sub PrintExit
{
  ## Fetch message
  my $msg = shift;

  ## Print to STDOUT
  print $msg;

  ## Die
  exit(2)
}