qpsmtpd/docs/advanced.pod

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#
# This file is best read with ``perldoc advanced.pod''
#
###
# Conventions:
# plugin names: F<myplugin>
# constants: I<LOGDEBUG>
# smtp commands, answers: B<HELO>, B<250 Queued!>
#
# Notes:
# * due to restrictions of some POD parsers, no C<<$object->method()>>
# are allowed, use C<$object-E<gt>method()>
#
=head1 Advanced Playground
=head2 Discarding messages
If you want to make the client think a message has been regularily accepted,
but in real you delete it or send it to F</dev/null>, ..., use something
like the following plugin and load it before your default queue plugin.
sub hook_queue {
my ($self, $transaction) = @_;
if ($transaction->notes('discard_mail')) {
my $msg_id = $transaction->header->get('Message-Id') || '';
$msg_id =~ s/[\r\n].*//s;
return(OK, "Queued! $msg_id");
}
return(DECLINED);
}
=head2 Changing return values
This is an example how to use the C<isa_plugin> method.
The B<rcpt_ok_maxrelay> plugin wraps the B<rcpt_ok> plugin. The B<rcpt_ok>
plugin checks the F<rcpthosts> and F<morercpthosts> config files for
domains, which we accept mail for. If not found it tells the
client that relaying is not allowed. Clients which are marked as
C<relay clients> are excluded from this rule. This plugin counts the
number of unsuccessfull relaying attempts and drops the connection if
too many were made.
The optional parameter I<MAX_RELAY_ATTEMPTS> configures this plugin to drop
the connection after I<MAX_RELAY_ATTEMPTS> unsuccessful relaying attempts.
Set to C<0> to disable, default is C<5>.
Note: Do not load both (B<rcpt_ok> and B<rcpt_ok_maxrelay>). This plugin
should be configured to run I<last>, like B<rcpt_ok>.
use Qpsmtpd::DSN;
sub init {
my ($self, $qp, @args) = @_;
die "too many arguments"
if @args > 1;
$self->{_count_relay_max} = defined $args[0] ? $args[0] : 5;
$self->isa_plugin("rcpt_ok");
}
sub hook_rcpt {
my ($self, $transaction, $recipient) = @_;
my ($rc, @msg) = $self->SUPER::hook_rcpt($transaction, $recipient);
unless (($rc == DENY) and $self->{_count_relay_max}) {
return $rc, @msg;
};
my $count =
($self->connection->notes('count_relay_attempts') || 0) + 1;
$self->connection->notes('count_relay_attempts', $count);
unless ($count > $self->{_count_relay_max}) {
return $rc, @msg;
};
return Qpsmtpd::DSN->relaying_denied(DENY_DISCONNECT,
"Too many relaying attempts");
}
=head2 Results of other hooks
B<NOTE:> just copied from README.plugins
If we're in a transaction, the results of a callback are stored in
$self->transaction->notes( $code->{name})->{"hook_$hook"}->{return}
If we're in a connection, store things in the connection notes instead.
B<FIXME>: does the above (regarding connection notes) work?
=cut
# vim: ts=2 sw=2 expandtab