#!perl -w

=head1 NAME

postfix-queue

=head1 DESCRIPTION

This plugin passes mails on to the postfix cleanup daemon.

=head1 CONFIG

The first optional parameter is the location of the cleanup socket. If it does
not start with a ``/'', it is treated as a flag for cleanup (see below).
The 'postfix_queue' plugin can also contain a list of cleanup socket paths
and/or remote postfix cleanup service hosts specified in the form of
'address:port'.  If set, the environment variable POSTFIXQUEUE overrides both
of these settings.

All other parameters are flags for cleanup, no flags are enabled by default.
See below in ``POSTFIX COMPATIBILITY'' for flags understood by your postfix
version. Supported by all postfix versions E<gt>= 2.1 are:

=over 4

=item FLAG_FILTER

Set the CLEANUP_FLAG_FILTER for cleanup. This enables the use of 
I<header_filter>, I<body_filter> or I<content_filter> in postfix' main.cf.

=item FLAG_BCC_OK

Setting this flag enables (for example) the I<recipient_bcc_maps> parameter

=item FLAG_MAP_OK

This flag enables the use of other recipient mappings (e.g. 
I<virtual_alias_maps>) in postfix' cleanup.

=item FLAG_MASK_EXTERNAL

This flag mask combines FLAG_FILTER, FLAG_MILTER (only in postfix >= 2.3)
FLAG_BCC_OK and FLAG_MAP_OK and is used by postfix for external messages.
This is probably what you want to use.

=back

For more flags see below in ``POSTFIX COMPATIBILITY'', your postfix version 
(grep _FLAG_ src/global/cleanup_user.h) and/or lib/Qpsmtpd/Postfix/Constants.pm

=head1 POSTFIX COMPATIBILITY

The first version of this plugin was written for postfix 1.x. 

The next step for Postfix 2.1 (and later) was to add the FLAG_FILTER, 
FLAG_BCC_OK and FLAG_MAP_OK flags for submission to the cleanup deamon.

This version can use all flags found in Postfix 2.x (up to 2.4 currently). 
Unknown flags are ignored by the cleanup daemon (just tested with postfix 
2.1), so it should be safe to set flags just understood by later versions 
of postfix/cleanup.

Even if all known flags can be set, some are not that useful when feeding
the message from qpsmtpd, e.g. 

=head2 FLAG_NONE

no effect 

=head2 FLAG_DISCARD

DON'T USE, use another plugin which hooks the I<hook_queue()> and returns 
B<OK> just for the messages you want to drop. As long as this plugin does
not support setting queue flags on the fly from other modules, this flag 
would drop ALL messages. Don't use!

=head2 FLAG_BOUNCE

Qpsmtpd should be configured not to accept bad messages...

=head2 FLAG_HOLD

Not useful in production setup, maybe in testing environment (untested, what 
real effects this has).

=over 4

=item Flags known by postfix 1.1:

   FLAG_NONE          - No special features
   FLAG_BOUNCE        - Bounce bad messages
   FLAG_FILTER        - Enable content filter

=item Flags known by postfix 2.1, 2.2

all flags from postfix 1.1, plus the following:
   FLAG_HOLD          - Place message on hold
   FLAG_DISCARD       - Discard message silently
   FLAG_BCC_OK        - Ok to add auto-BCC addresses 
   FLAG_MAP_OK        - Ok to map addresses 
   FLAG_MASK_INTERNAL - alias for FLAG_MAP_OK
   FLAG_MASK_EXTERNAL - FILTER, BCC_OK and MAP_OK

=item Flags known by postfix 2.3

all flags from postfix 2.1, up to FLAG_MASK_INTERNAL. New or changed:
   FLAG_MILTER        - Enable Milter applications
   FLAG_FILTER_ALL    - FILTER and MILTER
   FLAG_MASK_EXTERNAL - FILTER_ALL, BCC_OK, MAP_OK

=item Flags known by postfix 2.4

currently (postfix-2.4-20061019) the same as 2.3

=back

=head1 MAYBE IN FUTURE 

Settings the (additional) queue flags from another plugin. Currently at the
beginning of I<hook_queue()> all flags are reset to the flags given as plugin 
parameters.

=cut

use Qpsmtpd::Postfix;
use Qpsmtpd::Postfix::Constants;

sub register {
    my ($self, $qp, @args) = @_;

    $self->log(LOGDEBUG,
               "using constants generated from Postfix" . "v$postfix_version");
    $self->{_queue_flags} = 0;
    if (@args > 0) {
        if ($args[0] =~ m#^(/.+)#) {

            # untaint socket path
            $self->{_queue_socket} = $1;
            shift @args;
        }

        foreach (@args) {
            if ($self->can("CLEANUP_" . $_) and /^(FLAG_[A-Z0-9_]+)$/) {
                $_ = $1;
                $self->{_queue_flags} |= (eval "CLEANUP_$_;" || 0);

                #print STDERR "queue flag: $_: ".$self->{_queue_flags}."\n";
            }
            else {
                $self->log(LOGWARN, "Ignoring unkown cleanup flag $_");
            }
        }
    }
    else {
        $self->{_queue_socket} = "/var/spool/postfix/public/cleanup";
    }

    $self->{_queue_socket_env} = $ENV{POSTFIXQUEUE} if $ENV{POSTFIXQUEUE};

}

sub hook_queue {
    my ($self, $transaction) = @_;
    $transaction->notes('postfix-queue-flags', $self->{_queue_flags});
    my @queue;
    @queue = ($self->{_queue_socket_env}) if $self->{_queue_socket_env};
    @queue = $self->qp->config('cleanup_sockets') unless @queue;
    @queue = ($self->{_queue_socket} // ()) unless @queue;
    $transaction->notes('postfix-queue-sockets', \@queue) if @queue;

# $self->log(LOGDEBUG, "queue-flags=".$transaction->notes('postfix-queue-flags'));
    my ($status, $qid, $reason) = Qpsmtpd::Postfix->inject_mail($transaction);
    if ($status) {

        # this split is needed, because if cleanup returns
        # CLEANUP_STAT_MASK_INCOMPLETE we might return DENY (CLEANUP_STAT_SIZE)
        # instead of DENYSOFT (CLEANUP_STAT_WRITE, CLEANUP_STAT_BAD,
        # CLEANUP_STAT_DEFER) ... n.b. this is the behaviour of 667.
        foreach my $key (keys %cleanup_soft) {
            my $stat = eval $key    # keys have the same names as the constants
              or next;
            if ($status & $stat) {
                return DENYSOFT, $reason || $cleanup_soft{$key};
            }
        }
        foreach my $key (keys %cleanup_hard) {
            my $stat = eval $key    # keys have the same names as the constants
              or next;
            if ($status & $stat) {
                return DENY, $reason || $cleanup_hard{$key};
            }
        }

        # we have no idea why we're here.
        return DECLINED, $reason || "Unable to queue message ($status, $reason)";
    }

    my $msg_id = $transaction->header->get('Message-Id') || '';
    $msg_id =~ s/[\r\n].*//s;    # don't allow newlines in the Message-Id here
    return OK, "Queued! $msg_id (Queue-Id: $qid)";
}