plugins/bogus_bounce: add Return-Path check

make sure return path is empty, per RFC 3834
This commit is contained in:
Matt Simerson 2013-03-10 23:38:03 -04:00
parent b9750ee5bf
commit c3dff626cb

View File

@ -36,16 +36,11 @@ Deny with a soft error code.
2010 - Steve Kemp - http://steve.org.uk/Software/qpsmtpd/
=cut
=begin doc
Look for our single expected argument and configure "action" appropriately.
=end doc
2013 - Matt Simerson - added Return Path check
=cut
sub register {
my ($self, $qp) = (shift, shift);
@ -66,21 +61,11 @@ sub register {
}
}
=begin doc
Handle the detection of bounces here.
If we find a match then we'll react with our expected action.
=end doc
=cut
sub hook_data_post {
my ($self, $transaction) = (@_);
#
# Find the sender, and return unless it wasn't a bounce.
# Find the sender, quit processing if this isn't a bounce.
#
my $sender = $transaction->sender->address || undef;
if ( $sender && $sender ne '<>') {
@ -88,22 +73,24 @@ sub hook_data_post {
return DECLINED;
};
# at this point we know it is a bounce, via the null-envelope.
#
# Get the recipients.
# Count the recipients. Valid bounces have a single recipient
#
my @to = $transaction->recipients || ();
if (scalar @to == 1) {
$self->log(LOGINFO, "pass, only 1 recipient");
return DECLINED;
if (scalar @to != 1) {
$self->log(LOGINFO, "fail, bogus bounce to: " . join(',', @to));
return $self->get_reject( "fail, this bounce message does not have 1 recipient" );
};
#
# 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));
# validate that Return-Path is empty, RFC 3834
$self->get_reject( "fail, this is a bogus bounce" );
my $rp = $transaction->header->get('Return-Path');
if ( $rp && $rp ne '<>' ) {
$self->log(LOGINFO, "fail, bounce messages must not have a Return-Path");
return $self->get_reject( "a bounce return path must be empty (RFC 3834)" );
};
$self->log(LOGINFO, "pass, single recipient, empty Return-Path");
return DECLINED;
}