#!/usr/bin/perl -w
# productname: raidcheck
# productrelease: V0.50b
#
# copyright 2003-2004 by kapper.net
# reach kapper.net at http://kapper.net/ or via postal mail to:
# kapper & partner communications keg, kapper.net gmbh
#  loeblichgasse 6, A-1090 Vienna, Austria
# development-team: mm@kapper.net, hk@kapper.net
#
# 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
# http://www.gnu.org/licenses/gpl.txt

# ----------------------------------------------------
# project started: 30.09.2003
# ----------------------------------------------------
# synopsis:
# script writes data from "cat /proc/mdstat" into the file "/var/log/raidstatus".
# it also can compare the data with the current output of the above command.
# if specified the result of that comparision can be sent via email to the
# given email address
#
# requirements: Mail::Sendmail perl-class (available from http://alma.ch/perl/mail.html or CPAN)
#               local sendmail/postfix/whatever mailserver to deliver the sent email if required
#		alternatively you can edit Sendmail.pm to have your smtp-server globally set
# 
# usage: raidcheck.pl <params>
# 
# possible parameters
# -------------------
#         --read-mdstat | -r
#           reads data from /proc/mdstat and saves it in /var/log/raidstatus
# 
#         --check-mdstat | -c
#           reads data from /var/log/raidstatus and compares it with /proc/mdstat
#           if there is a difference, both is printed to STDOUT
#           --sendto <emailaddress> | -s
#             this is an optional parameter, if used, it requires an email address,
#             to which a possible difference between /var/log/raidstatus and /proc/mdstat
#             is sent.
#
#
#
# History:
# --------
# 05.08.2004	hk	first-output now is "current" status in email and printout for
#			a fast look at things in email-preview, etc
# 29.07.2004	hk	adopt for fedora-core-series of redhat, release it, short params
# 30.01.2004	hk	from-email-address is now always similar to to-address
# 30.01.2004	hk	added "die" option for raidstatus-file-open on check
# 20.01.2004	mm	added "O_CREAT" to sysopen in "--read-mdstat" case
# 06.09.2003	mm	ready for usage!
# 06.09.2003	mm	changed sysopen params when writing, added sendmail class calls
# 03.09.2003	mm	param checking, problem with some chars and their mysterious apperance
# 30.09.2003	mm	test with file io and mdstat call, usage, ...
#


use strict;
use Fcntl;				# for file io
use Mail::Sendmail;			# for sendmail class


my $CMD = "cat /proc/mdstat";		# cmd to get raid status
my $FILENAME = "/var/log/raidstatus";	# in that file raid status is saved when --read-mdstat
# if needed please change the above systemcall and filepath/-name.
# possible params
my $PARAM_READ  = "--read-mdstat";
my $PARAM_CHECK = "--check-mdstat";
my $PARAM_SEND  = "--sendto";
my $PARAM_READ_SHORT  = "-r";
my $PARAM_CHECK_SHORT = "-c";
my $PARAM_SEND_SHORT  = "-s";
# constants
my $PDEFAULT =  0b0000;
my $callparam = $PDEFAULT;	# don't ask ;-)
my $READ   = 0b1000;
my $CHECK  = 0b0100;
my $SEND   = 0b0010;
my $EQUAL  = 123443;
my $NOTEQUAL = 394342;
#my $FROM    = "";	# set to get a specific from-address
my $SUBJECT = "raidstatus failed: " . `hostname`;

# --------------------------------------------
# compares the 2 submitted strings and returns
# above specified constants for equal / notequal
sub compare($$)
{
	my $one = $_[0];
	my $two = $_[1];
	my $rc = $NOTEQUAL; 
	
	# - - - - - - - -
	$one =~ s/^\s+//;		# eliminates heading  "whitespaces" 
	$one =~ s/\s+$//;		# eliminates trailing "whitespaces" 	
	$two =~ s/^\s+//;		# eliminates heading  "whitespaces"
	$two =~ s/\s+$//;		# eliminates trailing "whitespaces"
	
	if ($one eq $two)		# if identical
	{
		$rc = $EQUAL;
	}
	return ($rc);
}	
# --------------------------------------------------------------------------
# give the user some hints on how to use...
sub usage
{
	my $usageinfo = "";
	
	$usageinfo .= "---------------------------------------------------------\n";
	$usageinfo .= "usage: $0 <params>\n\n";
	$usageinfo .= "possible parameters\n";
	$usageinfo .= "-------------------\n";	
	$usageinfo .= "\t--read-mdstat | -r\n";
	$usageinfo .= "\t  reads data from /proc/mdstat and saves it in $FILENAME\n\n";
	$usageinfo .= "\t--check-mdstat | -c\n";
	$usageinfo .= "\t  reads data from $FILENAME and compares it with /proc/mdstat\n";
	$usageinfo .= "\t  if there is a difference, both is printed to STDOUT\n";
	$usageinfo .= "\t  --sendto <emailaddress> | -s <email>\n";
	$usageinfo .= "\t    this is optional - if used - it requires an email address,\n";
	$usageinfo .= "\t    a possible difference between $FILENAME and /proc/mdstat\n";
	$usageinfo .= "\t    is sent to this address using this email also as from-tag.\n\n";
	$usageinfo .= "Have fun and may your mirrors never break ;)\n";
	$usageinfo .= "copyright 2003-2004 by http://kapper.net/\n\n";
	$usageinfo .= "---------------------------------------------------------\n";

	die "$usageinfo";
}
# ----------------------------------------
# main

{
	my $param = shift @ARGV;	# shift gets the next parameter and cuts it off ARGV
	my $infotxt = "";
	my ($mailadr,$cmdreply, $rc,$maxpos,$readdata);
	my %mail;	# sendmail needs this


	while (defined $param)		# as long as there are parameters
	{
		if (($param eq $PARAM_READ) || ($param eq $PARAM_READ_SHORT))
		{
			$callparam |= $READ;
		}
		elsif (($param eq $PARAM_CHECK) || ($param eq $PARAM_CHECK_SHORT))
		{
			$callparam |= $CHECK;
		}
		elsif (($param eq $PARAM_SEND) || ($param eq $PARAM_SEND_SHORT))
		{
			$callparam |= $SEND;
			$mailadr = shift @ARGV;				# next parameter needs to be an email address
			if (!($mailadr))
			{
				$callparam = $PDEFAULT; 		# default value ... means error and needs to show usage
			}
			else
			{
				if (!($mailadr =~m/.+\@.+\..+/))
				{
					$callparam = $PDEFAULT;		# default value ... means error and needs to show usage
				}
			}
		}
		else  						# no params
		{
			$callparam = $PDEFAULT; # default value ... means error and needs to show usage
		}		
		
		$param = shift @ARGV;	# get next parameter
	}	
		
	if ($callparam == ($READ | $SEND)) { $callparam = $PDEFAULT;}  # combined not possible
	if ($callparam == ($SEND))         { $callparam = $PDEFAULT;}  # no sendonly option
	
	&usage if ($callparam == $PDEFAULT);

	if (($callparam & $READ) == $READ)
	{
		$cmdreply = qx($CMD);			# get current mdstat info
		# O_WRONLY ... in "read" case, mdstat output will be written into file
		# O_CREAT  ... Create the file if it does not exist
		# O_TRUNC  ... truncate the file (esp. necessary if file exists and new mdstat output is 
		#              not as long as the "old" one stored in file
		$rc =sysopen(FH, $FILENAME, O_WRONLY | O_CREAT | O_TRUNC) or die "raidstatus-file cannot be opened\n";	
		if ($rc)
		{
			if (not (syswrite(FH, $cmdreply, length($cmdreply)-1)))
			{	
				print STDOUT "could not write raidstatus-file\n";
			}
		}	
		close(FH);

		$callparam = $PDEFAULT; # default value ... means error and needs to show usage
	}

	if (($callparam & $CHECK) == $CHECK)
	{
		$cmdreply = qx($CMD);
		$rc =sysopen(FH, $FILENAME, O_RDONLY) or die "raidstatus file not found!\n";	
		
		if ($rc)
		{
			$maxpos = sysseek(FH, 0, 2);		# check file length
			$rc = sysseek(FH,-$maxpos, 2);		# position on file begin
			$rc = sysread(FH, $readdata, $maxpos);	# get whole data
			
			if (!($rc))
			{
				print STDOUT "raidstatus could not be read from status-file!\n";
			}
			
			$rc = compare($cmdreply, $readdata);

			if ($rc == $NOTEQUAL)
			{
				$infotxt  = "----------------------------------------\n";
				$infotxt .= "Attention! raid-status changed: \n";
				$infotxt .= "----------------------------------------\n";
				$infotxt .= "current status shows:\n";
				$infotxt .= "----------------------------------------\n";
				$infotxt .= "$cmdreply";
				$infotxt .= "----------------------------------------\n";
				$infotxt .= "stored status:\n";
				$infotxt .= "----------------------------------------\n";
				$infotxt .= "$readdata\n";
				$infotxt .= "----------------------------------------\n";
				$infotxt .= "please check your raid and take\nappropriate action.\n";
				$infotxt .= "raid-status-check sponsored by http://kapper.net/\n";
			}
		
		}	
		close(FH); 
	
		if (($callparam & $SEND) == $SEND)
		{
			if ($infotxt ne "")
			{
				# set mail parameters for sending
				%mail = ( To   =>    $mailadr,
				          From =>    $mailadr,
				          Subject => $SUBJECT,
				          Message => $infotxt
				         );#
				sendmail(%mail) or die   $Mail::Sendmail::error;
				#print "OK. Log says:\n", $Mail::Sendmail::log;
			}
		}
		else
		{
			if ($infotxt)		# if param = --check-mdstat without email
			{
				print STDOUT "\n$infotxt\n";	
			}
		}			
	}
	

} # end main