qpsmtpd/plugins/bogus_bounce
2013-08-05 15:01:52 -07:00

110 lines
2.1 KiB
Perl

#!perl -w
=head1 NAME
bogus_bounce - Check that a bounce message isn't bogus
=head1 DESCRIPTION
This plugin is designed to reject bogus bounce messages.
In our case a bogus bounce message is defined as a bounce message
which has more than a single recipient.
=head1 CONFIGURATION
Only a single argument is recognized and is assumed to be the default
action. Valid settings are:
=over 8
=item log
Merely log the receipt of the bogus bounce (the default behaviour).
=item deny
Deny with a hard error code.
=item denysoft
Deny with a soft error code.
=back
=head1 AUTHOR
2010 - Steve Kemp - http://steve.org.uk/Software/qpsmtpd/
=cut
=begin doc
Look for our single expected argument and configure "action" appropriately.
=end doc
=cut
sub register {
my ($self, $qp) = (shift, shift);
if ( @_ % 2 ) {
$self->{_args}{action} = shift;
}
else {
$self->{_args} = { @_ };
};
if ( ! defined $self->{_args}{reject} ) {
$self->{_args}{reject} = 0; # legacy default
};
# we only need to check for deferral, default is DENY
if ( $self->{_args}{action} =~ /soft/i ) {
$self->{_args}{reject_type} = 'temp';
}
}
=begin doc
Handle the detection of bounces here.
If we find a match then we'll react with our expected action.
=end doc
=cut
sub hook_data_post {
my ($self, $transaction) = (@_);
#
# Find the sender, and return unless it wasn't a bounce.
#
my $sender = $transaction->sender->address || undef;
if ( $sender && $sender ne '<>') {
$self->log(LOGINFO, "pass, not a null sender");
return DECLINED;
};
#
# Get the recipients.
#
my @to = $transaction->recipients || ();
if (scalar @to == 1) {
$self->log(LOGINFO, "pass, only 1 recipient");
return DECLINED;
};
#
# at this point we know:
#
# 1. It is a bounce, via the null-envelope.
# 2. It is a bogus bounce, because there are more than one recipients.
#
$self->log(LOGINFO, "fail, bogus bounce for :" . join(',', @to));
$self->get_reject( "fail, this is a bogus bounce" );
}