A purely functional approach to packet processing

Today's rapidly evolving network ecosystem, characterized by increasing traffic volumes, service heterogeneity and mutating cyber-threats, calls for new approaches to packet pro-cessing to address key issues such as scalability, flexibility, programmability and fast deployment. To this aim, this paper explores a new direction to packet processing by pushing forward functional programming principles in the definition of a "software defined networking" paradigm. This result is achieved by introducing PFQ-Lang, an extensible functional language which can be used to process, analyze and forward packets captured on modern multiqueue NICs (for example, it allows to quickly develop the early stage of monitoring applications). An implementation of PFQ-Lang, embedded into high level programming languages as an eDSL (embedded Domain Specific Language) is also presented. The proposed approach allows an easy development by leveraging the intuitive functional composition and, at the same time, allows to exploit multi-queue NICs and multi-core architectures to process high-speed network traffic. Experimental results are provided to prove that the presented implementation reaches line rate performance on a 10Gb line card. To demonstrate the effectiveness and expressiveness of PFQ-Lang, the paper also presents a few use-cases ranging from forwarding, firewalling and monitoring of real traffic.