#!/usr/bin/perl

=pod

=head1 NAME $RCSfile: maps,v $

This script filters mail based on the files nulllist, blacklist and whitelist. 
Input is an email message. This script extracts the From line and then parses 
the email address. If the email is from a sender who should be /dev/null'ed 
(e.g. bounce messages from mail daemons) the message will be discarded. If the
sender is on the blacklist then a message is sent back informing the sender that
he's been blacklisted. If the sender is on the white list then the email is 
appended to the mail drop file. Otherwise a message is sent back informing the
sender that in order to successfully send email the sender must register for the
permission to do so, along with a URL that allows the sender to sign up.

=head1 VERSION

=over

=item Author

Andrew DeFaria <Andrew@DeFaria.com>

=item Revision

$Revision: 1.1 $

=item Created:

Fri Nov 29 14:17:21  2002

=item Modified:

$Date: 2013/06/12 14:05:47 $

=back

=head1 SYNOPSIS

 
 Usage maps: [-u|ser <username>] [-ve|rbose] [-deb|ug] [-e|xecute]

 Where:
   -u|ser <username>: Set context to this username
 
   -v|erbose:         Be verbose
   -de|bug:           Output debug messages
   
   -[no]e|xecute:     Set execute mode.         

# (c) Copyright 2000-2006, Andrew@DeFaria.com, all rights reserved.

=cut 

use strict;
use warnings;

use Getopt::Long;
use FindBin;
use File::Temp qw (tempfile);
use Net::Domain qw (hostdomain);

use lib $FindBin::Bin, '/opt/clearscm/lib';

use MAPS;
use MAPSLog;

use Display;
use Utils;

my $verbose	= 0;
my $execute	= 1;
my $userid 	 = $ENV{USER};

my $logpath	= "$FindBin::Bin/../log";
my $logfile	= "$logpath/debug.log";

# For some reason I'm not parsing messages correctly but it only seems to
# happen when the message is piped in from the MTA. This routine will
# temporarily save the messages in a file.
sub SaveStdin () {
  # Generate tempfile
  my $msgfile = tempfile ();

  # Read STDIN and write it out to the tempfile
  while (<STDIN>) {
    print $msgfile $_;
  } # while

  # Seek to the start of the file (Note if we closed it, it would be deleted)
  seek $msgfile, 0, 0;

  # Return the filehandle
  return $msgfile;
} # SaveStdin

sub save_msg {
  my ($sender, $sender_long, $reply_to, $subject, $data) = @_;

  open SAVED_MSG, ">>$logpath/$sender"
    or die "Unable to open $logpath/$sender - $!\n";

  print SAVED_MSG "Sender	= $sender\n";
  print SAVED_MSG "Sender long	= $sender\n";
  print SAVED_MSG "reply_to	= $reply_to\n";
  print SAVED_MSG "subject	= $subject\n";
  print SAVED_MSG "data:\n\n";
  print SAVED_MSG $data;
  print SAVED_MSG "*** END OF DATA***\n";
} # save_msg

sub ValidDomainUser ($) {
  my ($sender) = @_;

  my ($username, $domainname);

  if ($sender =~ /(.*)\@(.*)/) {
    $username	= $1;
    $domainname = $2;
  } else {
    return 1;
  } # if

  return 1 if $domainname ne hostdomain;

  # Let BICE email come through
  return 1 if $username eq "bice";

  my $uid = getpwnam $username;

  return defined $uid ? 1 : 0;
} # ValidDomainUser

sub ProcessMsgs ($$$) {
  my ($msgfile, $username, $user_email) = @_;

  return
    unless $execute;

  while (!eof *$msgfile) {
    my ($sender, $sender_long, $reply_to, $subject, $data) = ReadMsg (*$msgfile);

    my ($onlist, $rule, $sequence, $hit_count);

    if ($sender eq "" or $sender eq "@" or $sender =~ /.*\@$/) {
      verbose "Sender not found in message";
      next;
    } elsif ($sender eq $user_email and
            (lc ($sender_long) !~ lc ("\"$username\" <$user_email>") and
             lc ($sender_long) !~ lc ("$username <$user_email>"))) {
      verbose "Nulllisting message from sender ($sender_long) pretending to be $user_email";
      Nulllist $sender;
      next;
    } # if

    ($onlist, $rule, $sequence, $hit_count) = OnNulllist $sender;

    if ($onlist) {
      verbose "Nulllisting $sender";
      Nulllist $sender, $sequence, $hit_count;
      next;
    } # if

    ($onlist, $rule, $sequence, $hit_count) = OnBlacklist $sender;

    if ($onlist) {
      verbose "Blacklisting $sender";
      my @msg = split /\n/, $data;

      Blacklist $sender, $sequence, $hit_count, @msg;
      next;
    } # if 

    ($onlist, $rule, $sequence, $hit_count) = OnWhitelist $sender;

    if ($onlist) {
      if (ValidDomainUser $sender) {
	verbose "Whitelisting $sender";
	Whitelist $sender, $data, $sequence, $hit_count;
      } else {
	verbose "Sender from this domain but user not found";
	Nulllist $sender;
      } # if
    } else {
      if ($sender !~ /\@/) {
	verbose "Sender ($sender) does not appear to be a valid email address";
      } else {
        verbose "Returning message from $sender";
        ReturnMsg $sender, $reply_to, $subject, $data;
      } # if
    } # if
  } # while
} # ProcessMsgs

# Main
GetOptions (
  'user=s'	 => \$userid,
  'verbose'	 => sub { set_verbose },
  'debug'	   => sub { set_debug },
  'execute!' => \$execute,
) || Usage;

my $msgfile;

if ($ARGV[0] and $ARGV[0] ne "") {
  open $msgfile, $ARGV[0];

  if (!$msgfile) {
    Error "Unable to open file ($ARGV[0]): $!\n";
    exit 1;
  } # if
} else {
  $msgfile = SaveStdin;
} # if 

verbose "Starting MAPS....";

my ($username, $user_email) = SetContext $userid
  or die "$userid is not a registered MAPS user\n";

ProcessMsgs $msgfile, $username, $user_email;

exit 0;