In this paper we propose a novel hardware-software co-design vision that aims at enhancing flexibility and reusability of hardware based packet forwarding engines. In particular, we move on the path of the well-known OpenFlow architecture that allows the user to decide the action to be performed over the packet (drop, forward through a given port etc.) upon interaction with a software control plane. Although such an approach is certainly powerful and is gaining more and more attention in both academia and industry, it is biased towards routing application: its main goal is to allow the software control plane to arbitrarily route a packet flow. However, we think that a similar paradigm, encompassing high performance packet forwarding hardware driven by a flexible software control plane, may be beneficial even to other kinds of applications, like monitoring and measurements. However, the primitives that the OpenFlow protocol provides are not flexible enough for such purposes. For this reason, we propose a flexible packet forwarding architecture based on regular expression that, besides enabling standard-compliant OpenFlow switching, can be easily reconfigured through its control plane to support other kinds of applications.