#! /usr/bin/perl -w
#
# check_pop3_subject.pl
# Hacked together by Zach Armstrong
#
# Some code taken from:  http://mipagina.cantv.net/lem/perl/mfetch
# Some more code taken from: http://www.perlmonks.org/?node_id=196853
# This is the ultra hack mashup to have a nagios check that checks a pop3 account for an email with a specific subject line.
#
#
# Copyright (c) 2010 Zachary Armstrong
#
# 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
#
#
# 0 = ok
# 1 = warn
# 2 = crit
# 3 = unknown

#configurable options:
my $debug = 1;
my $deleteMatches = 1;
my $deleteNonMatches = 1;

# No changes below, unless you want to change exit codes
use lib "/usr/local/nagios/libexec" ;    
use Net::POP3;
use Getopt::Std;
use strict;
use IO::File;
use warnings;
use MIME::Parser;
use HTML::Parser;
use Unicode::Map8;
my $VERSION = '0.1';

use utils qw( %ERRORS);

use vars qw(  $wd $e $map $parser);

my $time_start = time;
my $msg_id;
my $subJ;
my %options=();
getopts("H:u:p:s:", \%options);
my $matchCount =0; #do not edit
my $deletedSpamCount =0; #do not edit

if (scalar(keys(%options))<4 ){
	print "usage: $0 -u username -p password -H hostname -s search_string \n";
	print "\n searches the subject for the given search_string, case sensative\n";
	exit  $ERRORS{'UNKNOWN'}; # This will register as unknown in nagios
}

my $i=0;
my $exit_value = $ERRORS{'UNKNOWN'} ;
my $pop;
my $return_val;

while ((!$pop) && (!$return_val) && ($i < 3))
{
$pop = Net::POP3->new($options{'H'}, 'Timeout' => 30, 'Debug' => 0);
unless (($pop) && ($i < 3)) { print "Unable to establish pop3 connection (tried $i times)!\n"; exit $ERRORS{'UNKNOWN'}; }

$return_val = $pop->login($options{'u'}, $options{'p'});
unless (($return_val) && ($i < 3)) { 
print "Unable to connect - invalid user/password or a timeout has occured\n"; exit $ERRORS{'CRITICAL'}; 
}
$i++;
}

my $Messages = $pop->list();
if ($Messages > 0) 
{

	for $msg_id (keys(%$Messages))
	{
		if ($debug) { print "Retrieving Msg: $msg_id\n"; }
		my $fh = new_tmpfile IO::File
			or blowUpB();
		my $MsgContent = $pop->get($msg_id, $fh);		    
		 $fh->seek(0, SEEK_SET);
		my $mp = new MIME::Parser;
		$mp->output_dir("/tmp");
		$mp->ignore_errors(1);
		$mp->extract_uuencode(1);
		eval { $e = $mp->parse($fh); };
		my $error = ($@ || $mp->last_error);

		if ($error)
		{
		    $mp->filer->purge;		# Get rid of the temp files
		    print "Error parsing the message: $error\n";
		    exit $ERRORS{'UNKNOWN'};
		}
		
		my $parser = HTML::Parser->new
		    (
		     api_version => 3,
		     default_h		=> [ "" ],
		     start_h => [ sub { print "[IMG ", 
					d($_[1]->{alt}) || $_[1]->{src},"]\n" 
					    if $_[0] eq 'img';
				    }, "tagname, attr" ],
		     text_h => [ sub { print d(shift); }, "dtext" ],
		     );
		
		$parser->ignore_elements(qw(script style));
		$parser->strict_comment(1);
		$map = Unicode::Map8->new('ASCII')
		or blowUp();

		setup_decoder($e->head);
		$subJ = d($e->head->get('subject'));
		if ($subJ =~ m/$options{'s'}/)
		{
			 if ($debug) {  print "Found ", $options{'s'}, " in subject\n"; }
			 $matchCount++;
			$exit_value =$ERRORS{'OK'};
			if ($deleteMatches)
			{ if ($debug) { print "Deleting message ", $msg_id,"\n"; }  my $delete_msg = $pop->delete($msg_id); }
		}
		else
		{
			if ($debug) {  print  $options{'s'}, " NOT FOUND in subject\n"; }
			if ($deleteNonMatches) 
			{ if ($debug) { print "Deleting message ", $msg_id,"\n"; }  my $delete_msg = $pop->delete($msg_id); $deletedSpamCount++; }
			
		}

		#  decode_entities($e);
		if ($debug) {  print "Subject: ", $subJ, "\n"; }
		
  		$mp->filer->purge;		
		#  my $delete_msg = $pop3->delete($msg_id) unless ($opt_c);
	}

} else {	
	print "Error: was unable to connect to POP account.\r\n";
	$exit_value = $ERRORS{'UNKNOWN'};
}

$pop->quit;

my $time_end = time;
my $elapsedtime = $time_end - $time_start;
my $report;
if ($exit_value == 0) 
{ 
	$report = "POP3 Receive OK: " . $elapsedtime . " seconds elapsed, " . $matchCount . " found";
	if ($deleteMatches) 
	{ 
		$report = $report . ", " . $matchCount . " deleted";
	} else { 
		$report = $report . ", deleting DISABLED";
	} 
	if ($deleteNonMatches) 
	{ 
		$report = $report . ", " . $deletedSpamCount . " non-matches deleted";
	} else {
		$report = $report . ", deleting non-matches DISABLED";
	}
	print ($report . "\n");
} elsif ($matchCount == 0 ) {
	print "No messages found!";
	$exit_value = 2;
}

exit $exit_value;

sub blowUp { print "Cannot create character map\n"; exit $ERRORS{'CRITICAL'}; }

sub blowUpB { print "Cannot create temporary file: $!\n"; exit $ERRORS{'CRITICAL'}; }

sub d { $map->to8($map->to16($wd->decode(shift||''))); }

sub setup_decoder
{
    my $head = shift;
    if ($head->get('Content-Type')
	and $head->get('Content-Type') =~ m!charset="([^\"]+)"!)
    {
	$wd = supported MIME::WordDecoder uc $1;
    }
    $wd = supported MIME::WordDecoder "ISO-8859-1" unless $wd;
}

sub decode_entities
{
    my $ent = shift;

    if (my @parts = $ent->parts)
    {
	decode_entities($_) for @parts;
    }
    elsif (my $body = $ent->bodyhandle)
    {
	my $type = $ent->head->mime_type;

	setup_decoder($ent->head);

	if ($type eq 'text/plain')
	{ print d($body->as_string); }
	elsif ($type eq 'text/html')
	{ $parser->parse($body->as_string); }
	else
	{ print "[Unhandled part of type $type]"; }
    }
}