AF_XDP

Purpose

Guide agents through AF_XDP sockets for high-performance packet I/O: socket creation, UMEM setup, fill/completion/RX/TX rings, XDP programs with XDP_REDIRECT to XSK, copy vs zero-copy modes, libbpf helpers, performance comparison with DPDK, and production use cases.

When to Use

• Building a userspace packet processor with lower overhead than raw sockets
• Redirecting XDP-filtered traffic to userspace without DPDK complexity
• Implementing a custom load balancer or IDS dataplane
• Comparing zero-copy vs copy mode on your NIC/driver
• Integrating with existing libbpf/XDP infrastructure
• Need kernel cooperation (firewall rules) plus userspace processing

Workflow

1. Architecture overview