cvs commit: qpsmtpd/plugins count_unrecognized_commands

cvsuser     03/04/15 10:39:03

  Added:       plugins  count_unrecognized_commands
  Log:
  unrecognized_command hook and a count_unrecognized_commands
    plugin. (Rasjid Wilcox)
  
  Revision  Changes    Path
  1.1                  qpsmtpd/plugins/count_unrecognized_commands
  
  Index: count_unrecognized_commands
  ===================================================================
  =head1 NAME
  
  count_unrecognized_commands - Count unrecognized commands and disconnect when we have too many
  
  =head1 DESCRIPTION
  
  Disconnect the client if it sends too many unrecognized commands.
  Good for rejecting spam sent through open HTTP proxies.
  
  =head1 CONFIGURATION
  
  Takes one parameter, the number of allowed unrecognized commands
  before we disconnect the client.  Defaults to 4.
  
  =cut
  
  sub register {
    my ($self, $qp, @args) = @_;
    $self->register_hook("unrecognized_command", "check_unrec_cmd");
  
    if (@args > 0) {
      $self->{_unrec_cmd_max} = $args[0];
      $self->log(1, "WARNING: Ignoring additional arguments.") if (@args > 1);
    } else {
      $self->{_unrec_cmd_max} = 4;
    }
  
    $self->{_unrec_cmd_count} = 0;
  }
  
  sub check_unrec_cmd {
    my ($self, $transaction, $cmd) = @_;
    
    $self->log(5, "Unrecognized command '$cmd'");
  
    $self->{_unrec_cmd_count}++;
  
    my $badcmdcount = $self->{_unrec_cmd_count};
  
    if ($badcmdcount >= $self->{_unrec_cmd_max}) {
      $self->log(5, "Closing connection. Too many unrecognized commands.");
      return (DENY, "Closing connection. $badcmdcount unrecognized commands.  Perhaps you should read RFC 2821?");
    }
  
    return DECLINED;
  }