[rt-devel] Crude blacklist for rt-mailgate

[Bob Finch]

I've hacked a crude blacklist into rt-mailgate that helps keep
annoying things like bounces from broken mailers and worm droppings
from creating new tickets.  It matches incoming mail against a list of
patterns and bounces the message to $RT::OwnerEmail if there is a
match.

There's currently no way to "approve" an incoming message that would
otherwise be blacklisted.  I've thought of a few ways to do it, but
haven't implemented anything yet.

This patch also changes the behavior of MailError.  It now attaches
the original message as a message/rfc822 attachment to the error
message.  This way, the original message is preserved as much as
possible.

Jesse -- you can do whatever you like with this if you find it
useful...

You need to add something like this to etc/config.pm:

# Blacklist is a reference to an array of references to two element
# arrays.  Each outer element describes one blacklist entry.  Each
# entry is a reference to an array containing the header name and a
# regular expression.
#
# If any blacklist entry matches the corresponding header in an
# incoming message, the message will be send to OwnerEmail instead of
# being handled normally.  Using "Body" as the header name will look
# for matches in all the text body parts.

$Blacklist = [
    [ "From", "maildaemon\@broken-mailer\\.com" ],
    [ "Subject", "Snowhite and the Seven Dwarfs" ],
    [ "Body", "\\nI send you this file in order to have your advice\\n" ],
];


Here's a patch against RT 2.0.7:


*** bin/rt-mailgate.orig	Thu Aug 23 16:49:18 2001
--- bin/rt-mailgate	Sat Sep 15 19:47:00 2001
***************
*** 27,32 ****
--- 27,33 ----
  			     ParseCcAddressesFromHead
  			     ParseSenderAddressFromHead 
  			     ParseErrorsToAddressFromHead
+ 			     MatchBodyPattern
  			    );
  
  #Clean out all the nasties from the environment
***************
*** 123,128 ****
--- 124,152 ----
  my $IsSuspiciousSender = CheckForSuspiciousSender($head);
  
  my $IsALoop = CheckForLoops($head);
+ 
+ 
+ # Send message to RT Owner if it is in the blacklist
+ my $blacklist = $RT::Blacklist;
+ for my $entry (@$blacklist) {
+     my ($field, $pattern) = @$entry;
+     if ($field eq "Body") {
+ 	if (MatchBodyPattern ($entity, $pattern)) {
+ 	    MailError(To => $RT::OwnerEmail,
+ 		      Subject => "RT Blacklist: $Subject",
+ 		      Explanation => "RT Blacklist: Body matches $pattern",
+ 		      MIMEObj => $entity);
+ 	    exit;
+ 	}
+     }
+     elsif ($head->get ($field) =~ /$pattern/) {
+ 	MailError(To => $RT::OwnerEmail,
+ 		  Subject => "RT Blacklist: $Subject",
+ 		  Explanation => "RT Blacklist: $field header matches $pattern",
+ 		  MIMEObj => $entity);
+ 	exit;
+     }
+ }
  
  
  #If the message is autogenerated, we need to know, so we can not 
*** lib/RT/Interface/Email.pm.orig	Thu Aug 23 21:08:30 2001
--- lib/RT/Interface/Email.pm	Sat Sep 15 20:24:00 2001
***************
*** 32,38 ****
  		      &ParseCcAddressesFromHead
  		      &ParseSenderAddressFromHead 
  		      &ParseErrorsToAddressFromHead
! 		      
  		      &debug);
  }
  =head1 NAME
--- 32,39 ----
  		      &ParseCcAddressesFromHead
  		      &ParseSenderAddressFromHead 
  		      &ParseErrorsToAddressFromHead
! 		      &MatchBodyPattern
! 
  		      &debug);
  }
  =head1 NAME
***************
*** 292,299 ****
      $entity->attach(  Data => $args{'Explanation'}."\n");
      
      my $mimeobj = $args{'MIMEObj'};
!     $mimeobj->sync_headers();
!     $entity->add_part($mimeobj);
      
      if ($RT::MailCommand eq 'sendmailpipe') {
          open (MAIL, "|$RT::SendmailPath $RT::SendmailArguments") || return(0);
--- 293,300 ----
      $entity->attach(  Data => $args{'Explanation'}."\n");
      
      my $mimeobj = $args{'MIMEObj'};
!     $entity->attach(  Type => "message/rfc822",
! 		      Data => $mimeobj->as_string);
      
      if ($RT::MailCommand eq 'sendmailpipe') {
          open (MAIL, "|$RT::SendmailPath $RT::SendmailArguments") || return(0);
***************
*** 538,543 ****
--- 539,572 ----
      my $Address = $AddrObj->address;
  
      return ($Address, $Name);
+ }
+ # }}}
+ 
+ # {{{ MatchBodyPattern
+ 
+ =head2 MatchBodyPattern ENTITY PATTERN
+ 
+ Return 1 if the body part of ENTITY matches pattern.  Recursively decends
+ through multipart bodies.
+ 
+ =cut
+ 
+ 
+ sub MatchBodyPattern {
+     my $entity = shift;
+     my $pattern = shift;
+ 
+     my $bh = $entity->bodyhandle;
+     if ($bh) {
+ 	if ($entity->effective_type() =~ /^text\//) {
+ 	    return $bh->as_string =~ $pattern;
+ 	}
+     }
+     else {
+ 	for my $part ($entity->parts) {
+ 	    return 1 if MatchBodyPattern ($part, $pattern);
+ 	}
+     }
  }
  # }}}
  
-- Bob