cvs commit: qpsmtpd/plugins check_earlytalker

cvsuser     03/04/15 10:39:27

  Added:       plugins  check_earlytalker
  Log:
  check_earlytalker plugin.  Deny the connection if the client talks
    before we show our SMTP banner.  (From Devin Carraway)
  
  Revision  Changes    Path
  1.1                  qpsmtpd/plugins/check_earlytalker
  
  Index: check_earlytalker
  ===================================================================
  =head1 NAME
  
  check_earlytalker - Check that the client doesn't talk before we send the SMTP banner
  
  =head1 DESCRIPTION
  
  Hooks connect, checks to see if the remote host starts talking before
  we've issued a 2xx greeting.  If so, we're likely looking at a
  direct-to-MX spam agent which pipelines its entire SMTP conversation,
  and will happily dump an entire spam into our mail log even if later
  tests deny acceptance.
  
  Such clients gets a 450 error code.  
  
  =head1 TODO
  
  Make how long we wait before reading from the socket configurable
  (currently 1 second)
  
  Make the soft/hard response code configurable (currently DENYSOFT)
  
  =cut
  
  use IO::Select;
  
  sub register {
    my ($self, $qp) = @_;
    $self->register_hook('connect', 'connect_handler');
  }
  
  sub connect_handler {
    my ($self, $transaction) = @_;
    my $in = new IO::Select;
    
    $in->add(\*STDIN) || return DECLINED;
    if ($in->can_read(1)) {
      $self->log(1, "remote host started talking before we said hello");
      return (DENYSOFT, "Don't be rude and talk before I say hello!");
    }
    $self->log(10,"remote host said nothing spontaneous, proceeding");
    return DECLINED;
  }