#!/usr/bin/perl -w
#
# check_snmp_mssql - nagios plugin 
# 
# Kaltashkin Eugene <zhecka@gmail.com >
#   inspiration by Douglas E. Warner <silfreed@silfreed.net> - check_snmp_gauge
#
# Douglas E. Warner <silfreed@silfreed.net>
#   inspiration by Christoph Kron <ck@zet.net> - check_ifstatus.pl
#
# 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.
#
#

use strict;

use Net::SNMP;
use Getopt::Long;
#use File::Basename;
&Getopt::Long::config('auto_abbrev');

my $version = "0.0.2";
my $status;
my $needhelp = '';
my $init = '';
my $compare = '';
my $TIMEOUT = 30;
my $tmppath = '/tmp';

my %ERRORS = (
              'OK' , '0',
              'WARNING', '1',
              'CRITICAL', '2',
              'UNKNOWN' , '3',
             );

# The state of the database. Valid states are defined as follows:
# Active(0,1), Single User(2), DBO Only(3), Read Only(4), Offline(5),
# Suspect(6), Loading(7), and Publishing(8).
# States from MSSQL-MIB

my %dbStat = (
		'0','OK',
		'1','Active',
		'2','Single User',
		'3','DBO use Only',
		'4','Read Only',
		'5','Offline',
		'6','Suspect',
		'7','Loading',
		'8','Publishing',
	      );


# default return value is UNKNOWN
my $state = "UNKNOWN";

# time this script was run
my $runtime = time();

# responses from script
my $answer = "";
my $error;

# external variable declarations
my $hostname;
my $community = "public";
my $port = 161;
my $snmpTable = ".1.3.6.1.4.1.311.1.4.1.1.5";

# snmp related variables
my $session;
my $response;
my $snmpkey;
my $key;
my $dbID;
my $dbName = '';
my $dbNamelc = '';
my $keyType;
my %dbNamesTmp;
my %dbStatus;
my %dbStatusTmp;

# the usage of this program (duh)
sub usage
{
	printf("== check_snmp_mssql v%s ==\n", $version);
	printf("  Perl SNMP Check MSSQL plugin for Nagios\n");
	printf("  Kaltashkin Eugene <zhecka\@gmail.com>\n");
	printf("  checks MSSQL databases status\n");
	printf("\n");
	printf("Usage: \n");
	printf("  check_snmp_mssql (-C|--snmpcommunity) <SNMPCOMMUNITY>\n");
	printf("                   [-p|--port] <PORT> (-H|--hostname) <HOSTNAME>\n");
	printf("                   [-d|--dbname] <Database name> [-i|--init] [-c|--compare]\n");
	printf("\n\n");
	exit $ERRORS{"UNKNOWN"};
}

# for sorting things numerically
sub numerically
{
	$a <=> $b
} # end numerically

# get Statuses the user wants from host
sub getStatusList
{
	# get the value(s) for the oid given
	($session, $error) = Net::SNMP->session(
		-hostname  => $hostname,
		-community => $community,
		-port      => $port
	);

	if (!defined($session)) {
		exitout (
		$state = "UNKNOWN",
		$answer = $error
		);
	}

	if (!defined($response = $session->get_table($snmpTable))) {
		$answer = $session->error;
		$session->close;
		$state = "WARNING";
		print "$state: $answer,$community,$snmpTable";
		exit $ERRORS{$state};
	}

	foreach $snmpkey (sort keys %{$response}) {
		$snmpkey =~ /.*\.(\d+)\.(\d+)\.(\d+)$/;
		$keyType = $1;
		$dbID = $2;
		$key = $3;
		$dbNamesTmp{$dbID} = lc($response->{$snmpkey}) if ($keyType == 2);
		$dbStatusTmp{$dbID} = $response->{$snmpkey} if ($keyType == 3);
	}

	foreach $dbID (sort numerically keys %dbNamesTmp) {
	my $dbNameTmp = $dbNamesTmp{$dbID};
	my $dbStatTmp = $dbStatusTmp{$dbID};
	$dbStatus{$dbNameTmp} = $dbStatTmp;
	}

	undef %dbNamesTmp;
	undef %dbStatusTmp;
	$session->close;
} # end getStatusList

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

if (scalar(@ARGV) == 0) {
	usage();
} # end if no options, give usage

Getopt::Long::Configure("no_ignore_case");
$status = GetOptions("h|help"				=> \$needhelp,
                     "C|snmpcommunity=s"		=> \$community,
                     "p|port=i"				=> \$port,
                     "H|hostname=s"			=> \$hostname,
                     "d|dbname=s"			=> \$dbName,
                     "i|init"				=> \$init,
                     "c|compare"			=> \$compare
                     );

if ($status == 0 || $needhelp) {
print "Usage";
	&usage();
}

# check temporary path
if (!($tmppath)) {
	exitout (
	$state = "UNKNOWN",
	$answer = "Please define temporary path in script\n"
	);
}

if (!-d $tmppath) {
	exitout (
	$state = "CRITICAL",
	$answer = "Directory $tmppath not accessible\n"
	);
}
# end check path

# begin check for hostname
if (!defined($hostname)) {
	exitout (
	$state = "UNKNOWN",
	$answer = "Hostname must be specified\n"
	);
} # end check for hostname

getStatusList();

if ($init)
{
$tmppath .= '/' if ($tmppath !~ /\/$/);
my $fname = $tmppath.'dblist_'.$hostname;
open OUT,">$fname" or exitout (
	$state = "CRITICAL",
	$answer = "Create file $!\n"
	);
foreach $dbID ( sort keys %dbStatus )
{
print OUT $dbID,"\n";
}
close OUT;
exitout (
	$state = "OK",
	$answer = "DB List initialized succesfully\n"
	);
}

if ($compare)
{
$tmppath .= '/' if ($tmppath !~ /\/$/);
my $fname = $tmppath.'dblist_'.$hostname;
# check filename exists
if(!-f $fname) {
		exitout	(
			$state = "CRITICAL",
			$answer = "Database list file not found, please run script with --init option\n"
			);
		}
open OUT,"<$fname" or exitout (
	$state = "CRITICAL",
	$answer = "Open file $!\n"
	);
my %dblst;
# pushing file content into hash for compare
foreach $dbID (<OUT>) { chomp $dbID;$dblst{$dbID} = 1; }
close OUT;
# check exist keys in two hashes, if found delete keys
foreach $dbID ( keys %dbStatus )
{
if (exists $dbStatus{$dbID} && exists $dblst{$dbID}) { delete $dbStatus{$dbID}; delete $dblst{$dbID}; }
}
# after compare hashes have differences
my $lenold = scalar keys %dblst; # databases deleted
my $lennew = scalar keys %dbStatus; # databases created
if ($lenold > 0)
	{
		my $tmp = join ",",keys %dblst;
		exitout (
			$state = "CRITICAL",
			$answer = "Database: $tmp has been deleted\n"
			);
	}
if ($lennew > 0)
	{
		my $tmp = join ",",keys %dbStatus;
		exitout (
			$state = "WARNING",
			$answer = "Found new Database: $tmp\n"
			);
	}
exitout (
	$state = "OK",
	$answer = "No difference found\n"
	);

}



if ($dbName)
{
	$dbNamelc = lc($dbName);
	if(!exists $dbStatus{$dbNamelc})
	{
		exitout (
		$state = "UNKNOWN",
		$answer = "Status of Database $dbName unknown or Database not exist\n"
		);
	}
	else
	{
		if($dbStatus{$dbNamelc} > 1)
		{
			exitout (
			$state = "CRITICAL",
			$answer = $dbName." ".$dbStat{$dbStatus{$dbNamelc}}."\n"
			);
		}
		else
		{
			exitout (
			$state = "OK",
			$answer = $dbName." ".$dbStat{$dbStatus{$dbNamelc}}."\n"
			);
			
		}
	}
	
}

$state = "OK";

foreach $dbID (sort keys %dbStatus) {
	if ($dbStatus{$dbID} > 1)
		{
			$state = "CRITICAL";
			$answer .= $dbID." ".$dbStat{$dbStatus{$dbID}}.",";
		}
} # end foreach $key

# Truncate last comma
$answer =~ s/\,$//;

# setup final message
$answer = "ALL Databases OK" if(length($answer) < 2);
$answer .= "\n";
print ("$state: $answer");
exit $ERRORS{$state};

sub exitout
{
	print "$state: $answer";
	exit $ERRORS{$state};
}