#!/usr/bin/perl -w
# -*- perl -*-

=head1 NAME

snmp__screenos_ - SNMP plugin to monitor Juniper ScreenOS based routers

=head1 APPLICABLE SYSTEMS

This has been developed against a Juniper SSG5-Serial router, but
should work with any ScreenOS-based router as manufactured by Juniper.

Using a command such as "munin-node-configure --snmp
switch.langfeldt.net --snmpversion 2c --snmpcommunity public | sh -x"
should identify whether this plugin can apply.


=head1 CONFIGURATION

As a rule SNMP plugins need site specific configuration.  The default
configuration (shown here) will only work on insecure sites/devices:

   [snmp_*]
	env.version 2
        env.community public

In general SNMP is not very secure at all unless you use SNMP version
3 which supports authentication and privacy (encryption).  But in any
case the community string for your devices should not be "public".

Please see 'perldoc Munin::Plugin::SNMP' for further configuration
information.

=head1 MIB INFORMATION

This plugin requires NETSCREEN-RESOURCE-MIB information.

=head1 MAGIC MARKERS

  #%# family=snmpauto
  #%# capabilities=snmpconf

=head1 AUTHOR

Copyright (C) 2012 Diego Elio Pettenò.

=head1 LICENSE

GPLv2

=cut

use strict;
use Munin::Plugin;
use Munin::Plugin::SNMP;

# This corresponds to NETSCREEN-SMI::netscreenResource
my $oidBase = '1.3.6.1.4.1.3224.16';

my $oidMemAllocate = $oidBase . '.2.1';
my $oidMemLeft = $oidBase . '.2.2';
my $oidSessAllocate = $oidBase . '.3.2';
my $oidSessMaximum = $oidBase . '.3.3';
my $oidSessFailed = $oidBase . '.3.4';

if (defined $ARGV[0] and $ARGV[0] eq "snmpconf") {
    print "require $oidBase.[23].[13].0";
}

my $session = Munin::Plugin::SNMP->session();
my $data = $session->get_entries(-columns => [ $oidMemAllocate,
					       $oidMemLeft,
					       $oidSessAllocate,
					       $oidSessMaximum,
					       $oidSessFailed ]);

if ($ARGV[0] and $ARGV[0] eq "config") {
  my ($host) = Munin::Plugin::SNMP->config_session();

  my $memTotal = $data->{"$oidMemAllocate.0"} + $data->{"$oidMemLeft.0"};

  # this is the closet I can get to the yellow/red on the ScreenOS
  # interface.
  my $memWarning = int($memTotal * 0.75 + 0.5);
  my $memCritical = int($memTotal * 0.85 + 0.5);
  my $sessWarning = int($data->{"$oidSessMaximum.0"} * 0.75 + 0.5);
  my $sessCritical = int($data->{"$oidSessMaximum.0"} * 0.85 + 0.5);

  print <<END;
host_name $host

multigraph screenos_memory
graph_title Memory allocation
graph_vlabel bytes
graph_args --base 1024
graph_category system

memory.label Memory
memory.min 0
memory.max $memTotal
memory.warning $memWarning
memory.critical $memCritical

multigraph screenos_sessions
graph_title Sessions allocation
graph_vlabel Count
graph_category system

sessions.label Active Sessions
sessions.min 0
sessions.max $data->{"$oidSessMaximum.0"}
sessions.warning $sessWarning
sessions.critical $sessCritical
failed.label Failed Sessions
failed.min 0
failed.critical 1
END

  exit 0;
}

print <<END;
multigraph screenos_memory
memory.value $data->{"$oidMemAllocate.0"}

multigraph screenos_sessions
sessions.value $data->{"$oidSessAllocate.0"}
failed.value $data->{"$oidSessFailed.0"}
END