This talk will introduce XDP (eXpress Data Path), and explain how this is essentially a new (programmable) network layer in-front of the existing network stack. Then it will dive into the details of the new XDP redirect feature, which goes beyond forwarding packets out other NIC devices.
The eXpress Data Path (XDP) has been gradually integrated into the Linux kernel over several releases. XDP offers fast and programmable packet processing in kernel context. The operating system kernel itself provides a safe execution environment for custom packet processing applications, in form of eBPF programs, executed in device driver context. XDP provides a fully integrated solution working in concert with the kernel’s networking stack. Applications are written in higher level languages such as C and compiled via LLVM into eBPF bytecode which the kernel statically analyses for safety, and JIT translates into native instructions. This is an alternative approach, compared to kernel bypass mechanisms (like DPDK and netmap).
Jesper Dangaard Brouer, Red Hat