=item $id = $res->bgread()

Similar to C<Net::DNS::Resolver::bgread>.  Reads a DNS packet from

a supplied socket, decodes it, and returns a Net::DNS::Packet object

if successful.  Dies on error.

=cut

sub bgread() {

  my ($self) = @_;

  my $sock = $self->{sock};

  my $packetsize = $self->{res}->udppacketsize;

  $packetsize = 512  if $packetsize < 512;  # just in case

  my $data = '';

  my $peeraddr = $sock->recv($data, $packetsize+256);  # with some size margin for troubleshooting

  defined $peeraddr or die "bgread: recv() failed: $!";

  my $peerhost = $sock->peerhost;

  $data ne '' or die "bgread: received empty packet from $peerhost";

  dbg("dns: bgread: received %d bytes from %s", length($data), $peerhost);

  my($answerpkt, $decoded_length) = Net::DNS::Packet->new(\$data);

  $answerpkt or die "bgread: decoding DNS packet failed: $@";

  $answerpkt->answerfrom($peerhost);

  if ($decoded_length ne length($data)) {

    warn sprintf("bgread: received a %d bytes packet from %s, decoded %d bytes\n",

                 length($data), $peerhost, $decoded_length);

  }

  return $answerpkt;

}

###########################################################################

#   Bug 7265, use our own bgread()

#   my $packet = $self->{res}->bgread($self->{sock});