#!/usr/bin/perl -w
#
# check_softraid.pl - Nagios plugin to check software RAID status on Linux
#
#
# Copyright (C) 2003  Kenny Root
#
# 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.
#
#
# Report bugs to: kenny@the-b.org, nagiosplug-help@lists.sf.net
#
# 30-05-2003 Version 0.2
#
#

use strict;
use Getopt::Long;
use lib "nagios/plugins";
use utils qw($TIMEOUT %ERRORS &print_revision &support);
use vars qw($PROGNAME $MDSTAT $VERSION $opt_h $opt_V $exitstatus $exitstring);
Getopt::Long::Configure('bundling');

$PROGNAME="check_softraid";
$VERSION="0.2";
$MDSTAT="/proc/mdstat";

# Paranoia: clear out our environment variables.
$ENV{'PATH'} = '';
$ENV{'BASH_ENV'} = '';
$ENV{'ENV'} = '';

# Set the exit status to 0 (OK) until proven otherwise.
$exitstatus = $ERRORS{'OK'};
$exitstring = '';

# Create a timeout in case we can't read the mdstat file.
$SIG{'ALRM'} = sub {
        print ("ERROR: Cannot read $MDSTAT\n");
        exit $ERRORS{'UNKNOWN'};
};
alarm($TIMEOUT);

GetOptions("V" => \$opt_V, "version" => \$opt_V,
	   "h" => \$opt_h, "help" => \$opt_h);

# Print out the program version if requested.
if ($opt_V) {
	print_revision($PROGNAME,$VERSION);
	exit $ERRORS{'OK'};
}

# Print usage information if requested.
if ($opt_h) {
	print_help();
	exit $ERRORS{'OK'};
}

# Don't be tricked into opening a symlink.
if (! -f $MDSTAT) {
	print "$MDSTAT is not a regular file!\n";
	exit $ERRORS{'UNKNOWN'};
}

open(MDSTAT, "< $MDSTAT");

# Initialize the hash that will hold all the information about the status
# of each RAID device.
my %raid = ();

while (readline(*MDSTAT)) {
	chomp;

	# Parse each line in the mdstat.  Each RAID device should have three
	#  lines.  One for the personality and disk status, the second for
	#  the RAID personality's status.  The third line is for things like
	#  resync.
	# md1 : active raid1 hda2[1] hdb2[2]
	#       82348723 blocks [2/2] [UU]
	#
	if ($_ =~ /^(md[0-9]*) : ([^ ]*) ([^ ]*)( \(read-only\))? ([^\[]*\[.*)/) {
		my $device = $1;
		$raid{$device}{status} = $2;
		$raid{$device}{personality} = $3;
		my $diskstring = $5;

		# Split the disk status string into each disk, record those
		# into an array for possible parsing during the RAID status
		# line.  Also record if they're flagged as faulty disks.
		my @raiddisks = split(/ /, $diskstring);
		for my $eachdisknum (0 .. $#raiddisks) {

			# Each disk status would like like "hda2[1]" or
			# "hda2[1](F)" for a faulty disk.
			if ($raiddisks[$eachdisknum] =~ /([^\[]*)\[([0-9]*)\](\(F\))?$/) {
				my $diskname = $1;
				push @{$raid{$device}{disks}}, $diskname;

				# Record if this device is marked as faulted.
				if (defined $3 and ($3 eq "(F)")) {
					push @{$raid{$device}{faulted}}, $diskname;
				}
			}
		}

		# If the RAID device is active, the RAID personality should
		# have a status message as the second line.  Let's parse that.
		if ($raid{$device}{status} eq "active") {
			my $syncstatusline = <MDSTAT>;
			chomp $syncstatusline;

			# RAID1 and RAID5 personalities have a status line that
			# tells you whether you're out of sync or not.  Parse
			# that.
			if ($syncstatusline =~ / \[([0-9]*)\/([0-9]*)\] \[([^\]]*)\]/) {
				# Record the number of total disks, number of
				# disks operational, and compute the current
				# operational capacity.
				$raid{$device}{totaldisks} = $1;
				$raid{$device}{operationaldisks} = $2;
				$raid{$device}{capacity} = ($2 * 100) / $1;

				# Each operational disk is listed as "U"
				# while each out-of-sync disk is listed as "_"
				my $diskstatusstring = $3;
				my @diskstatuses = split //, $diskstatusstring;
				foreach my $disknumber (0 .. $#diskstatuses) {
					if (substr($diskstatusstring, $disknumber, 1) eq "_") {
						push @{$raid{$device}{desync}}, @{$raid{$device}{disks}}[$disknumber];
					}
				}
			}
		}
	}
}
close(MDSTAT);

foreach my $device (sort keys %raid) {
	if ($raid{$device}{status} eq "active") {
		if (exists $raid{$device}{faulted}) {
			$exitstring = $exitstring . "$device has faulted disks " . join(" ", @{$raid{$device}{faulted}}) . ". ";
			$exitstatus = $ERRORS{'CRITICAL'};
		} elsif (exists $raid{$device}{desync}) {
			$exitstring = $exitstring . "$device has desynced disks " . join(" ", @{$raid{$device}{desync}}) . ". ";
			$exitstatus = $ERRORS{'WARNING'} if ($exitstatus != $ERRORS{'CRITICAL'});
		}
	}
}

if ($exitstring eq "") {
	$exitstring = "All RAID disks OK.";
}

print $exitstring . "\n";
exit $exitstatus;

sub print_help {
	printf "$PROGNAME plugin for Nagios monitors Linux's software RAID \n";
	printf "status for the local machine.\n";
	printf "\nUsage:\n";
	printf "\t-V (--version)\tPlugin version\n";
	printf "\t-h (--help)\tThis usage help.\n\n";
	print_revision($PROGNAME, $VERSION);
}