qpsmtpd/plugins/queue/maildir

#!perl -Tw

=head1 NAME

queue/maildir

=head1 DESCRIPTION

This plugin delivers mails to a maildir spool.

=head1 CONFIG

It takes one required parameter, the location of the maildir.

A second optional parameter delivers the mail into a sub directory named by 
the recipient of the mail B<for each recipient>. Some substituions take place.
Before replacing the parts descibed below, any character of the recipient 
address, which is not one of C<-A-Za-z0-9+_.,@=> is set to a C<_>.

If a third parameter is given, it will be used as octal (!) permisson of the
newly created files and directories, any execute bits will be stripped for 
files: Use C<770> to create group writable directories and files with mode 
C<0660>.

=head2 Maildir spool directory substitutions

=over 4

=item %l

Replaced by the local part of the address (i.e. the username)

=item %d

Replaced by the domain part of the address (i.e. the domain name)

=item %u

Replaced by the full address.

=cut 

# =item %%
# 
# Replaced by a single percent sign (%)
# 
# =cut

=back

Examples: if the plugin is loaded with the parameters

  queue/maildir /var/spool/qpdeliver %d/%l

and the recipient is C<user@example.com> the mails will be written to
the C<new> sub directory of C</var/spool/qpdeliver/example.com/user/>.

With 

  queue/maildir /var/spool/qpdeliver %u

and a recipient of C<user@example.org> the mail goes to
C</var/spool/qpdeliver/user@example.org>.

=head1 NOTES

Names of the substitution parameters and the replaced charachters are the same
L<spamd(8)> supports, for more info see the C<--virtual-config-dir> 
option of L<spamd(8)>.

When called with more than one parameter, this plugin is probably not usable
with qpsmtpd-async.

With the the second parameter being C<%d> it will still deliver one message 
for each recipient: With the two recpients C<user@example.org> and 
C<user2@example.org> you get two messages in the C<example.org/> directory.

=cut

use File::Path qw(mkpath);
use Sys::Hostname qw(hostname);
use Time::HiRes qw(gettimeofday);

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

  if (@args > 0) {
    ($self->{_maildir}) = ($args[0] =~ m!([-/\w\.]+)!);
  }

  if (@args > 1) {
    ($self->{_subdirs}) = ($args[1] =~ m#^(.*\%[ldu].*)$#);
    unless ($self->{_subdirs}) {
      $self->log(LOGWARN, "WARNING: sub directory does not contain a "
                         ."substitution parameter");
      return 0;
    }
  }

  if (@args > 2) {
    ($self->{_perms}) = ($args[2] =~ /^([0-7]{3})$/);
    unless ($self->{_perms}) { # 000 is unfortunately true ;-) 
      $self->log(LOGWARN, "WARNING: mode is not an octal number");
      return 0;
    }
    $self->{_perms} = oct($self->{_perms});
  }

  $self->{_perms} = 0700
    unless $self->{_perms};

  unless ($self->{_maildir}) {
    $self->log(LOGWARN, "WARNING: maildir directory not specified");
    return 0;
  }

  unless ($self->{_subdirs}) {
    # mkpath is influenced by umask...
    my $old_umask = umask 000;
    map { my $d = $self->{_maildir} . "/$_"; -e $d or mkpath $d, 0, $self->{_perms} } qw(cur tmp new);
    umask $old_umask;
  }

  my $hostname = (hostname =~ m/([\w\._\-]+)/)[0];
  $self->{_hostname} = $hostname;

}

my $maildir_counter = 0;

sub hook_queue {
  my ($self, $transaction) = @_;
  my ($rc, @msg);
  my $old_umask = umask($self->{_perms} ^ 0777);

  if ($self->{_subdirs}) {
    foreach my $addr ($transaction->recipients) {
      ($rc, @msg) = $self->deliver_user($transaction, $addr);
      unless($rc == OK) {
        umask $old_umask;
        return ($rc, @msg);
      }
    }
    umask $old_umask;
    return (OK, @msg); # last @msg is the same like any other before...
  }

  $transaction->header->add('Delivered-To', $_->address, 0)
    for $transaction->recipients;
  ($rc, @msg) = $self->write_file($transaction, $self->{_maildir});
  umask $old_umask;
  return ($rc, @msg);
}

sub write_file {
  my ($self, $transaction, $maildir, $addr) = @_;
  my ($time, $microseconds) = gettimeofday;

  $time = ($time =~ m/(\d+)/)[0];
  $microseconds =~ s/\D//g;

  my $unique  = "P$$" . "M$microseconds" . "Q" . $maildir_counter++;
  my $file    = join ".", $time, $unique, $self->{_hostname};

  open (MF, ">$maildir/tmp/$file") or
    $self->log(LOGWARN, "could not open $maildir/tmp/$file: $!"),
    return(DECLINED, "queue error (open)");

  print MF "Return-Path: ", $transaction->sender->format , "\n";

  print MF "Delivered-To: ",$addr->address,"\n"
    if $addr; # else it had been added before...

  $transaction->header->print(\*MF);
  $transaction->body_resetpos;
  while (my $line = $transaction->body_getline) {
    print MF $line;
  }
  close MF or
    $self->log(LOGWARN, "could not close $maildir/tmp/$file: $!")
    and return(DECLINED, "queue error (close)");

  link "$maildir/tmp/$file", "$maildir/new/$file" or
    $self->log(LOGWARN, "could not link $maildir/tmp/$file to $maildir/new/$file: $!")
    and return(DECLINED, "queue error (link)");

  unlink "$maildir/tmp/$file";

  my $msg_id = $transaction->header->get('Message-Id') || '';
  $msg_id =~ s/[\r\n].*//s;

  return (OK, "Queued! $msg_id");
}

sub deliver_user {
  my ($self, $transaction, $addr) = @_;
  my $user = $addr->user; $user =~ tr/-A-Za-z0-9+_.,@=/_/c;
  my $host = $addr->host; $host =~ tr/-A-Za-z0-9+_.,@=/_/c;
  my $rcpt = $user.'@'.$host;

  my $subdir = $self->{_subdirs};
  $subdir =~ s/\%l/$user/g;
  $subdir =~ s/\%d/$host/g;
  $subdir =~ s/\%u/$rcpt/g;
#  $subdir =~ s/\%%/%/g;

  my $maildir = $self->{_maildir}."/$subdir";
  my $old_umask = umask 000;
  map { my $d = $maildir . "/$_"; -e $d or mkpath $d, 0, $self->{_perms} } qw(cur tmp new);
  umask $old_umask;

  return $self->write_file($transaction, $maildir, $addr);
}