#!/usr/bin/perl -w
#
# Virtual Vacation 3.2
# by Mischa Peters <mischa at high5 dot net>
# Copyright (c) 2002 - 2005 High5!
# Licensed under GPL for more info check GPL-LICENSE.TXT
#
# Additions:
# 2004/07/13   David Osborn <ossdev at daocon.com>
#               Uses strict, processes domain level aliases, more
#               subroutines, send reply from original to address
# 2004/11/09   David Osborn <ossdev at daocon.com>
#               Added syslog support          
#               Slightly better logging which includes messageid
#               Avoid infinite loops with domain aliases
#
# 2005/07/20   David Osborn <ossdev at daocon.com>
#               Added threading headers to reply
#               Fixed problem of sending reply to wrong To:
#
# 2005/07/21   Brian Taber <btaber at diversecg.com>
#               Added error handling in case of database errors
#               to prevent bounced email
#
use DBI;
use strict;
use Sys::Syslog;

my $db_type = 'mysql';
my $db_host = 'localhost';
my $db_user = 'postfixadmin';
my $db_pass = 'postfixadmin';
my $db_name = 'postfix';
my $sendmail = "/usr/sbin/sendmail";
my $logfile = "";    # specify a file name here for example: vacation.log
my $debugfile = "";  # sepcify a file name here for example: vacation.debug
my $syslog = 0;   # 1 if log entries should be sent to syslog


my $dbh = DBI->connect("DBI:$db_type:$db_name:$db_host", "$db_user", "$db_pass", { RaiseError => 1 }) or &exit_error($DBI::errstr);

# make sure vacation.pl exists cleanly when it encounters an error
sub exit_error {
	syslog('mail|warning', 'virtual vacation failure: %s', shift);
	exit (0);
}

# used to detect infinite address lookup loops
my $loopcount=0;

sub do_query {
   my ($query) = @_;
   my $sth = $dbh->prepare($query) or &exit_error("Can't prepare $query: $dbh->errstr");
   $sth->execute or die "Can't execute the query: $sth->errstr";
   return $sth;
}

sub do_debug {
   my ($in1, $in2, $in3, $in4, $in5, $in6) = @_;
   if ( $debugfile ) {
      my $date;
      open (DEBUG, ">> $debugfile") or &exit_error("Unable to open debug file");
      chop ($date = `date "+%Y/%m/%d %H:%M:%S"`);
      print DEBUG "====== $date ======\n";
      printf DEBUG "%s | %s | %s | %s | %s | %s\n", $in1, $in2, $in3, $in4, $in5, $in6;
      close (DEBUG); 
   }
}

sub do_cache {
   my ($to, $from) = @_;
   my $query = qq{SELECT cache FROM vacation WHERE email='$to' AND FIND_IN_SET('$from',cache)};
   my $sth = do_query ($query);
   my $rv = $sth->rows;
   if ($rv == 0) {
      $query = qq{UPDATE vacation SET cache=CONCAT(cache,',','$from') WHERE email='$to'};
      $sth = do_query ($query);
   }
   return $rv;
}

sub do_log {
   my ($messageid, $to, $from, $subject) = @_;
   my $date;
   if ( $syslog ) {
       open (SYSLOG, "|/usr/bin/logger -p mail.info -t Vacation") or die ("Unable to open logger"); 
       printf SYSLOG "Orig-To: %s From: %s MessageID: %s Subject: %s", $to, $from, $messageid, $subject;
       close (SYSLOG); 
   }
   if ( $logfile ) {
       open (LOG, ">> $logfile") or die ("Unable to open log file");
       chop ($date = `date "+%Y/%m/%d %H:%M:%S"`);
       print LOG "$date: To: $to From: $from Subject: $subject MessageID: $messageid \n";
       close (LOG);
   }
}

sub do_mail {
   my ($from, $to, $subject, $body, $orig_msgID) = @_;
   # clean up the email address since we pass it to the commandline
   my $fromemail = $from;
   if ($fromemail =~ /([\w\-.%]+\@[\w.-]+)/) { $fromemail = $1; }
   open (MAIL, "| $sendmail -t -f \"$fromemail\"") or die ("Unable to open sendmail");
   print MAIL "From: $from\n";
   print MAIL "To: $to\n";
   print MAIL "Subject: $subject\n";
   if ( $orig_msgID ) {
        print MAIL "References: $orig_msgID\n";
        print MAIL "In-Reply-To: $orig_msgID\n";
   }
   print MAIL "X-Loop: Postfix Admin Virtual Vacation\n\n";
   print MAIL "$body";
   close (MAIL) or die ("Unable to close sendmail");
}

sub find_real_address {
   my ($email) = @_;
   if (++$loopcount > 20) {
      do_log ("find_real_address loop!", "currently: $email", "ERROR", "ERROR"); 
      print ("possible infinite loop in find_real_address for <$email>. Check for alias loop\n");
      exit 1;
   }
   my $realemail;
   my $query = qq{SELECT email FROM vacation WHERE email='$email' and active=1};
   my $sth = do_query ($query);
   my $rv = $sth->rows;

   # Recipient has vacation
   if ($rv == 1) {
        $realemail = $email;

   } else {
      $query = qq{SELECT goto FROM alias WHERE address='$email'};
      $sth = do_query ($query);
      $rv = $sth->rows;

      #  Recipient is an alias, check if mailbox has vacation
      if ($rv == 1) {  
         my @row = $sth->fetchrow_array;
         my $alias = $row[0];
         $query = qq{SELECT email FROM vacation WHERE email='$alias' and active=1};
         $sth = do_query ($query);
         $rv = $sth->rows;

         # Alias has vacation
         if ($rv == 1) {
             $realemail = $alias;
         }

      # We still have to look for domain level aliases...
      } else {
        my ($user, $domain) = split(/@/, $email);
        $query = qq{SELECT goto FROM alias WHERE address='\@$domain'};
        $sth = do_query ($query);
        $rv = $sth->rows;

        # The receipient has a domain level alias
        if ($rv == 1) {  
         my @row = $sth->fetchrow_array;
         my $wildcard_dest = $row[0];
         my ($wilduser, $wilddomain) = split(/@/, $wildcard_dest);

         # Check domain alias
         if ($wilduser) { 
           ($rv, $realemail) = find_real_address ($wildcard_dest);
         } else {  
           my $new_email = $user . '@' . $wilddomain;
           ($rv, $realemail) = find_real_address ($new_email);
         }
        }
      }
   }
   return ($rv, $realemail);
}

sub send_vacation_email {
   my ($email, $orig_subject, $orig_from, $orig_to, $orig_messageid) = @_;
   my $query = qq{SELECT subject,body FROM vacation WHERE email='$email'};
   my $sth = do_query ($query);
   my $rv = $sth->rows;
   if ($rv == 1) {
      my @row = $sth->fetchrow_array;
      if (do_cache ($email, $orig_from)) { return; }
      $row[0] =~ s/\$SUBJECT/$orig_subject/g;
      $row[1] =~ s/\$SUBJECT/$orig_subject/g;
      do_debug ("[SEND RESPONSE] for $orig_messageid:\n", "FROM: $email (orig_to: $orig_to)\n", "TO: $orig_from\n", "SUBJECT: $orig_subject\n", "VACATION SUBJECT: $row[0]\n", "VACATION BODY: $row[1]\n");
      do_mail ($orig_to, $orig_from, $row[0], $row[1], $orig_messageid);
      do_log ($orig_messageid, $orig_to, $orig_from, $orig_subject); 
   }
}

########################### main #################################

my ($from, $to, $cc, $subject, $messageid);

# Take headers apart
while (<STDIN>) {
   last if (/^$/);
   if (/^from:\s+(.*)\n$/i) { $from = $1; }
   if (/^to:\s+(.*)\n$/i) { $to = $1; }
   if (/^cc:\s+(.*)\n$/i) { $cc = $1; }
   if (/^subject:\s+(.*)\n$/i) { $subject = $1; }
   if (/^message-id:\s+(.*)\n$/i) { $messageid = $1; }
   if (/^precedence:\s+(bulk|list|junk)/i) { exit (0); }
   if (/^x-loop:\s+postfix\ admin\ virtual\ vacation/i) { exit (0); }
}

# If either From: or To: are not set, exit
if (!$from || !$to) { exit (0); }

$from = lc ($from);

# Check if it's an obvious sender, exit
if ($from =~ /([\w\-.%]+\@[\w.-]+)/) { $from = $1; }
if ($from eq "" || $from =~ /^owner-|-(request|owner)\@|^(mailer-daemon|postmaster)\@/i) { exit (0); }

# Strip To: and Cc: and push them in array
my @strip_cc_array; 
my @strip_to_array = split(/, */, lc ($to) );
if (defined $cc) { @strip_cc_array = split(/, */, lc ($cc) ); }
push (@strip_to_array, @strip_cc_array);

my @search_array;

# Strip email address from headers
for (@strip_to_array) {
   if ($_ =~ /([\w\-.%]+\@[\w.-]+)/) { 
        push (@search_array, $1); 
        #do_debug ("[STRIP RECIPIENTS]: ", $messageid, $1, "-", "-", "-");
   }
}

# Search for email address which has vacation
for my $to (@search_array) {
   my ($rv, $email) = find_real_address ($to);
   if ($rv == 1) {
         do_debug ("[FOUND VACATION]: ", $messageid, $from, $to, $email, $subject);
         send_vacation_email( $email, $subject, $from, $to, $messageid);
   }
}

0;