64b92755b5
before we show our SMTP banner. (From Devin Carraway) git-svn-id: https://svn.perl.org/qpsmtpd/trunk@135 958fd67b-6ff1-0310-b445-bb7760255be9
43 lines
1.1 KiB
Plaintext
43 lines
1.1 KiB
Plaintext
=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;
|
|
}
|