Crate xdp_socket

xdp-socket

A minimal and efficient Rust implementation of AF_XDP sockets for high-performance packet processing. This crate provides a low-level, transparent API to interact with XDP sockets, enabling direct, zero-copy access to network interfaces for both transmit and receive operations.

Features

• Simple and flexible API for AF_XDP sockets
• Support for both TX and RX directions
• UMEM management and ring buffer handling
• Utilities for polling, sending, and kernel wakeup
• Designed for integration with async runtimes or custom event loops

This crate is intended for developers building fast packet processing applications or custom networking stacks in Rust.

Main Components

• Socket: The main type representing an AF_XDP socket, parameterized by direction (TX or RX). Provides methods for sending, receiving, and managing descriptors.
• [UMEM]: User memory region for zero-copy packet buffers, shared with the kernel.
• Ring Buffers: Fill, Completion, TX, and RX rings for packet flow control and synchronization with the kernel.
• PollWaitExt: Trait for blocking until the socket is ready for I/O.
• SendExt: Trait for high-level, ergonomic packet sending on transmit sockets.

Descriptor Flow: seek → peek → commit → kick

The typical workflow for both sending and receiving packets involves the following steps:

1. seek: Reserve one or more descriptors in the ring buffer, ensuring space for packet data.
2. peek: Access the reserved UMEM region for reading (RX) or writing (TX) packet data.
3. commit: Mark the descriptor as ready for the kernel (TX) or for user processing (RX).
4. kick: Notify the kernel to process the descriptors if the ring requires wakeup.

This flow enables efficient, lock-free packet exchange between user space and the kernel, minimizing syscalls and maximizing throughput. For TX, you write data after seek/peek, then commit and kick. For RX, you seek/peek to fetch data, then commit to release the descriptor back to the kernel.

Re-exports

pub use create::Direction;

pub use create::XdpConfig;

pub use create::create_bi_socket;

pub use create::create_rx_socket;

pub use create::create_socket;

pub use create::create_tx_socket;

pub use socket::Socket;

pub use poll::PollWaitExt;

Modules

create

AF_XDP Socket Creation and Configuration

mmap

Memory Mapping for UMEM

peek

Peeking at Descriptors in XDP Rings

poll

XDP Socket Poll Utilities

ring

AF_XDP Ring Buffer Management

socket

XDP Socket Implementation

Traits

SendExt

A trait for high-level packet sending operations on XDP transmit sockets.