#!/usr/bin/perl -w
#
# $Id: check_email_loop.pl 1290 2005-11-29 23:21:06Z harpermann $
#
# (c)2000 Benjamin Schmid, blueshift@gmx.net (emergency use only ;-)
# Copyleft by GNU GPL
#
#
# check_email_loop Nagios Plugin
#
# This script sends a mail with a specific id in the subject via
# an given smtp-server to a given email-adress. When the script
# is run again, it checks for this Email (with its unique id) on
# a given pop3 account and send another mail.
# 
#
# Example: check_email_loop.pl -poph=mypop -popu=user -pa=password
# 	   -smtph=mailer -from=returnadress@yoursite.com
#	   -to=remaileradress@friend.com -pendc=2 -lostc=0
#
# This example will send eacht time this check is executed a new
# mail to remaileradress@friend.com using the SMTP-Host mailer.
# Then it looks for any back-forwarded mails in the POP3 host
# mypop. In this Configuration CRITICAL state will be reached if  
# more than 2 Mails are pending (meaning that they did not came 
# back till now) or if a mails got lost (meaning a mail, that was
# send later came back prior to another mail).
# 
# Michael Markstaller, mm@elabnet.de various changes/additions
# MM 021003: fixed some unquoted strings
# MM 021116: fixed/added pendwarn/lostwarn
# MM 030515: added deleting of orphaned check-emails 
#					  changed to use "top" instead of get to minimize traffic (required changing match-string from "Subject: Email-ping [" to "Email-Ping ["

use Net::POP3;
use Net::SMTP;
use strict;
use Getopt::Long;
&Getopt::Long::config('auto_abbrev');

# ----------------------------------------

my $TIMEOUT = 120;
my %ERRORS = ('OK' , '0',
              'WARNING', '1',
              'CRITICAL', '2');
              'UNKNOWN' , '3');

my $state = "UNKNOWN";
my ($sender,$receiver, $pophost, $popuser, $poppasswd, $smtphost,$keeporphaned);
my ($poptimeout,$smtptimeout,$pinginterval,$maxmsg)=(60,60,5,50);
my ($lostwarn, $lostcrit,$pendwarn, $pendcrit,$debug);
$debug = 0;

# Internal Vars
my ($pop,$msgcount,@msglines,$statinfo,@messageids,$newestid);
my (%other_smtp_opts);
my ($matchcount,$statfile) = (0,"check_email_loop.stat");

# Subs declaration
sub usage;
sub messagematchs;
sub nsexit;

# Just in case of problems, let's not hang Nagios
$SIG{'ALRM'} = sub {
     print ("ERROR: $0 Time-Out $TIMEOUT s \n");
     exit $ERRORS{"UNKNOWN"};
};
alarm($TIMEOUT);


# Evaluate Command Line Parameters
my $status = GetOptions(
		        "from=s",\$sender,
			"to=s",\$receiver,
                        "debug", \$debug,
                        "pophost=s",\$pophost,
                        "popuser=s",\$popuser,
			"passwd=s",\$poppasswd,
			"poptimeout=i",\$poptimeout,
			"smtphost=s",\$smtphost,
			"smtptimeout=i",\$smtptimeout,
			"statfile=s",\$statfile,
			"interval=i",\$pinginterval,
			"lostwarn=i",\$lostwarn,
			"lostcrit=i",\$lostcrit,
			"pendwarn=i",\$pendwarn,
			"pendcrit=i",\$pendcrit,
			"maxmsg=i",\$maxmsg,
			"keeporphaned=s",\$keeporphaned,
			);
usage() if ($status == 0 || ! ($pophost && $popuser && $poppasswd &&
	$smtphost && $receiver && $sender ));

# Try to read the ids of the last send emails out of statfile
if (open STATF, "$statfile") {
  @messageids = <STATF>;
  chomp @messageids;
  close STATF;