#!/usr/bin/perl -w

# Copyright (C) 2020 debizoh / Masami Ohkubo

use Encode 'decode';
use utf8;
use Net::Telnet();

my $rtx_host     = $ENV{host}      || undef;
my $rtx_passwd_l = $ENV{login_password}      || undef;
my $rtx_passwd_a = $ENV{admin_password}      || undef;
my $DEBUG = 0;
my $rtx_port = 23;

if ($0 =~ /^(?:|.*\/)nat_([^_]+)_nat$/)
{
	$rtx_host  = $1;
	if ($rtx_host =~ /^([^:]+):(\d+)$/)
	{
		$rtx_host = $1;
		$rtx_port = $2;
	}
}
elsif (!defined($rtx_host))
{
	print "# Debug: $0 -- $1\n" if $DEBUG;
	die "# Error: couldn't understand what I'm supposed to monitor.";
}

if($ARGV[0] and $ARGV[0] eq "config") {
	print "host_name $rtx_host\n";
    print "graph_title RTX nat requests\n";
    print "graph_args --base 1000 -l 0 -u 65535\n";
    print "graph_vlabel requests\n";
    print "graph_order requests\n";
    print "graph_scale no\n";
    print "graph_category system\n";
    print "requests.label requests\n";
    print "requests.cdef requests\n";
    print "requests.type GAUGE\n";
    print "requests.draw AREA\n";
    print "requests.min 0\n";
    print "requests.max 65535\n";
    exit 0;
}

sub query_rtx {
    my ($host, $login_password, $admin_password) = @_;

	$host = $host;
	$login_password = $login_password;
	$admin_password = $admin_password;
	$natget_cmd = 'show nat descriptor address';

	use Net::Telnet ();
	my($t) = new Net::Telnet (Timeout => 10,Binmode=> 1);
	$t->input_record_separator("\n");
	$t->output_record_separator("\n");
	$t->open($host);
	$t->waitfor('/Password: ?$/i');
	$t->print($login_password);

	$t->prompt('/> $/');
	#doesn't require administrator
	#$t->print('administrator');
	#$t->waitfor('/Password: ?$/i');
	#$t->print($admin_password);
	#$t->waitfor('/\# ?$/i');
	#$t->prompt('/# ?$/');

	$t->print('console lines infinity');

	@lines = $t->cmd($natget_cmd);
	#print @lines;

	$natcount = 0;
	$match = 0;
	foreach $text (@lines)
	{
		$str = decode('cp932', $text);
		#print $str;
		if ($str =~ m/^.*?(\d+)個使用中.*?/)
		{
			$match = 0;
			$natcount = $1;
			last;
		}
		if ($match == 0)
		{
			if ($str =~ m/^.*?(\d+)(\s)セッション.*?/)
			{
				$natcount = $1;
				last;
			}
		}
	}
	#print "Nat: $natcount" . "\n";
	return ($natcount);

}

#print $rtx_host;
#print $rtx_passwd_l;
#print $rtx_passwd_a;

print "requests.value ", &query_rtx ($rtx_host, $rtx_passwd_l, $rtx_passwd_a), "\n";