#!/usr/bin/perl -w
#
# Copyright (c) 2012 Ralf Schiffers <ralf.schiffers@bmw-kirsch.de>
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#
################################################################################
# This script is used check the the bayes database of Spamassassin is up-to-date
# and running. As we cannot tie directly to the database we use a file generated
# by sa-learn as input.
# If the newest entry in the database is older than the specified time (default
# for warning is 60 minutes, for critical 120 minuts) it will trigger warning/
# critical state.
# 
# Furthermore the scripts prints the number of spams, hams and tokens in
# Spamassassins bayes database.
#
# In order to use this script, you might need to make the following
# adjustments:
#  - Set the path to your sa-learn output.
#  - setup a cronjob to generate the necessary sa-learn output
#  Example: 30 * * * * /usr/bin/sa-learn -u amavis --dbpath /var/amavis/.spamassassin/bayes --dump magic > /tmp/sabayes
#
# This scripts needs the following perl modules (available via CPAN)
#  - Getopt::Long
#
################################################################################

use strict;
use Getopt::Long;
use vars qw ($opt_h $opt_w $opt_c);

# Where is sa-learn output generated by cron-job?
my $sa_output = "/tmp/sabayes";

# Default warning and critical of age of newest token in database (minutes)
my $warn_level = 60;
my $crit_level = 120;

######################## Nothing to change below this ##########################

my $script = "check_bayes";
my $script_version = "1.0.0";

# Check sa-learn output exists and is readable for us
if (!-r $sa_output) {
  die("ERROR: Unable to read $sa_output");
}

# Get the Options
Getopt::Long::Configure('bundling');
GetOptions
  ("h"   => \$opt_h, "help"       => \$opt_h,
   "w=i" => \$opt_w, "warning=i"  => \$opt_w,
   "c=i" => \$opt_c, "critical=i" => \$opt_c,
  );

if ($opt_h) {
  usage();
}

$warn_level = $opt_w if defined $opt_w;
$crit_level = $opt_c if defined $opt_c;

if ($warn_level >= $crit_level) {
  die ("ERROR: Warning must not be greater or equal than Critical");
}

# Get the current date to compare it with bayes-Database entry

my $current_timescan = time();

# Get the date of current database

my @sa_learn_output;

open (FILE, $sa_output) || die $!;
while (<FILE>) {
 my $zeile = $_;
 chomp ($zeile);
 push (@sa_learn_output, $zeile);
}
close FILE;


# Get number of spam mails in database
my @spams = split(/ +/,$sa_learn_output[1]);
my $spamcount = $spams[2];

# Get number of ham mails in database
my @hams = split(/ +/,$sa_learn_output[2]);
my $hamcount = $hams[2];

# Get number of tokens in database
my @satokens = split(/ +/,$sa_learn_output[3]);
my $satokencount = $satokens[2];

# Get timestamp of newest token in database
my @newesttoken = split(/ +/,$sa_learn_output[5]);
my $newest_token_stamp = $newesttoken[2];

# Difference between current time and newest timestamp

my $time_diff = int (($current_timescan - $newest_token_stamp) / 60);

# Compare the times and set exit code for Nagios

my $bayes_status = "Spamassassin bayes OK - newest entry is $time_diff minutes old ($spamcount Spams, $hamcount Hams, $satokencount Tokens in Bayes database)\n";
my $plugin_status = 0;

if ($time_diff >= $crit_level) {
  $bayes_status = "Spamassassin bayes CRITICAL - newest entry is $time_diff minutes old ($spamcount Spams, $hamcount Hams, $satokencount Tokens in Bayes database)\n";
  $plugin_status = 2;
}
elsif ($time_diff >= $warn_level) {
  $bayes_status = "Spamassassin bayes WARNING - newest entry is $time_diff minutes old ($spamcount Spams, $hamcount Hams, $satokencount Tokens in bayes database)\n";
  $plugin_status = 1; 
}
     
print $bayes_status;
exit $plugin_status;
        

################################################################################
# help and usage information                                                   #
################################################################################

sub usage {
  print << "USAGE";
-----------------------------------------------------------------
$script v$script_version
    
Nagios plugin to check if Spamasassin bayes database is working
    
Usage: $script -w <warn_level> -c <crit_level>
    
Options: -h	show this help
         -w	generate a warning state if newest entray in
                bayes database is older than <w> minutes
                (default is 60)
         -c     generate a critical state if newest entra in
                bayes database is older than <c> minutes
                (default is 120)
                      
-----------------------------------------------------------------
Copyright (C) 2012 Ralf Schiffers. All rights reserved
                      
This program is free software; you can redistribute it or modify
it under the terms of the GNU General Public License
-----------------------------------------------------------------
                      
USAGE
  exit 0;
}