Linux Network Programming with P 4

P4 is a domain-specific language for implementing network data-planes. The P4 abstraction allows programmers to write network protocols in a generalized fashion, without needing to know the configuration specifics of the targeted data-plane. The extended Berkely Packet Filter (eBPF) is a safe virtual machine for executing sand-boxed programs in the Linux kernel. eBPF, and its extension the eXpress Data Path (XDP), effectively serve as programmable data-planes of the kernel. P4C-XDP is a project combining the performance of XDP with the generality and usability of P4. In this document, we describe how P4 can be translated into eBPF/XDP. We review the fundamental limitations of both technologies, analyze the performance of several generated XDP programs, and discuss problems we have faced while working on this new technology.