Configuring eBPF Kernel Socket Filters (9358)
Technical Overview
Engineering breakdown of Configuring eBPF Kernel Socket Filters (9358). Bare-metal hardware performance requires isolated kernel parameters, deterministic latency, and zero-copy packet processing. This guide walks through the complete lifecycle: writing a BPF_PROG_TYPE_SOCKET_FILTER program, loading it via bpf() syscall, attaching to a socket with setsockopt(SO_ATTACH_BPF), and validating filter logic through kernel verifier logs.
Key Concepts
- Socket Filter Hook: Executes in softirq context, before protocol processing.
- Verifier Constraints: No loops, bounded stack, valid memory accesses.
- Map Integration: Use
BPF_MAP_TYPE_ARRAYfor runtime configuration.
eBPF/XDP kernel filter evaluates TCP/UDP frames directly on server NIC.