copy(b, bb)
	return len(bb), nil
}

func (f *fakeDNSConn) Write(b []byte) (int, error) {
	if f.tcp && len(b) >= 2 {
		b = b[2:]
	}
	if f.q.Unpack(b) != nil {
		return 0, fmt.Errorf("cannot unmarshal DNS message fake %s (%d)", f.n, len(b))
	}
	return len(b), nil
}

func (f *fakeDNSConn) SetDeadline(t time.Time) error {
	f.t = t
	return nil
}

type fakeDNSPacketConn struct {
	PacketConn