#!/usr/bin/perl
# -*- perl -*-
# ---------------------------------------------------- #
# File : netscaler_conn
# Author: Sandro Wefel
# based on Script by Damien SIAUD
# Date : 05/05/2011
# Modified : 05/05/2011
# ---------------------------------------------------- #
# This script require Net::SNMP
#
# Netscaler plugin for munin
#
# License Information:
# 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 3 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, see <http://www.gnu.org/licenses/>. 
#
# ---------------------------------------------------- # 

=head1 NAME

netscaler_conn - Munin plugin to monitor netscaler connections

=head1 CONFIGURATION

Make a symlink from netscaler_conn_ to /etc/munin/plugins/netscaler_conn_<nsfqdn>. 
You can omit <nsfqdn>, then you need the env variable B<host>.

To configure the plugin, use ENV variables.

Add something lile this to /etc/munin/plugin-conf.d/<conf>
 [netscaler_conn_*]
 env.community CommunityName

Variables:

=over

=item ENV B<host> netscaler host as FQDN or IP I<default is the nsfqdn-suffix from pluginname>

=item ENV B<port> I<default 161>

=item ENV B<community> I<default "public">

=item ENV B<timeout> in seconds I<default 5>

=back

=head1 AUTHORS

=over

=item Sandro Wefel <wefel@unixos.de>

=item based on scripts by Jimmy Olsen, Damien SIAUD

=back

=head1 LICENSE

GNU General Public License

=head1 MAGIC MARKERS

 #%# family=auto
 #%# capabilities=autoconf

=cut

use Net::SNMP;

use Munin::Plugin;

use vars qw($script_name $script_version $o_host $o_community $o_port $o_timeout);

use strict;


# --------------------------- globals -------------------------- #

$script_name = "netscaler_conn";
$script_version = "0.1";

$o_host = undef;
$o_community = undef;
$o_port = 161;

my $return_str = "";

# ---------------------------- snmp ---------------------------- #

my $oid_prefix = "1.3.6.1.4.1.5951";
my $oid_build_version = $oid_prefix.".4.1.1.1.0";
my $oid_ssl_session = $oid_prefix.".4.1.1.47.296.0";	# current ssl sessions
my $oid_client_conn = $oid_prefix.".4.1.1.46.2.0";	# current client connections
my $oid_server_conn = $oid_prefix.".4.1.1.46.1.0";	# current server connections

# ---------------------------- main ----------------------------- #


my $DEBUG = 0;

my $o_host      = $ENV{host}      || undef;
my $o_port      = $ENV{port}      || 161;
my $o_community = $ENV{community} || "public";
my $o_timeout   = $ENV{timeout}   || 5;

if ($ARGV[0] and $ARGV[0] eq "autoconf") {
		print "yes\n";
		exit 0;
}

if (! defined $o_host ) {
	$0 =~ /.*onnections?_(.+)*$/;
	$o_host = $1;
	die "No host provided or unabled to extract hostname from $0" unless defined $o_host;
}

if ($ARGV[0] and $ARGV[0] eq "config") {
    print "graph_args --base 1024 -l 0\n";
    print "graph_vlabel Connections\n";
    print "graph_title Netscaler Connections for $o_host\n";
    print "graph_category netscaler\n";
    print "graph_period second\n";
    print "graph_info This graph shows the netscaler TCP connections.\n";
    print "graph_order ",
	"client ",
	"server ",
	"ssl ",
	"\n";
    print "client.label client\n";
    print "client.draw AREA\n";
    print "client.info Client connections.\n";
    print "server.label server\n";
    print "server.draw STACK\n";
    print "server.info Server connections.\n";
    print "ssl.label SSL sessions\n";
    print "ssl.draw LINE2\n";
    print "ssl.info Currently active SSL sessions.\n";

    for my $field qw(client server ssl) {
        print_thresholds($field);
    }
    exit 0;
}


my $session = &open_session();
if (!defined($session)) {
	print "ERROR opening session\n";
	exit 1;
}

my $counter1;
# TCP
$counter1 = &get_oid_values($session,$oid_client_conn);
$return_str .= "client.value $counter1\n";
$counter1 = &get_oid_values($session,$oid_server_conn);
$return_str .= "server.value $counter1\n";
# SSL
$counter1 = &get_oid_values($session,$oid_ssl_session);
$return_str .= "ssl.value $counter1\n";

&close_session($session);

print "$return_str"; 
exit 0;

# --------------------------- functions ------------------------- #

sub open_session {
	my ($sess, $str) = Net::SNMP->session(
		-hostname	=> $o_host,
		-community	=> $o_community,
		-port		=> $o_port,
		-timeout	=> $o_timeout
	);

	$return_str = $str;

	return $sess;
}


sub close_session {
	my ($sess) = @_;

	if(defined($sess)){
		$session->close;
	}
}

sub get_buildversion {
	my ($session) = @_;
       	my $build_version;
	
	my $result = $session->get_request(
		      -varbindlist => [$oid_build_version]
	);

	if (!defined($result)) {
		return "na";
	}
	else {
		$build_version = $result->{$oid_build_version};
		return"Build version : ".$build_version;
	}
}

sub get_oid_values {
        my ($session,$oid_string) = @_;
        my $return_value;

        my $result = $session->get_request(
                -varbindlist => [$oid_string]
        );

        if (!defined($result)) {
                return "na";
        }
        else {  
                $return_value = $result->{$oid_string};
                return $return_value;
        }
}