Module afpacket 

Available on crate feature afpacket only.

AF_PACKET sockets: attach to an existing network interface.

This is the plainest way to put a real NIC into a topology. Unlike the tuntap feature it does not create a new interface — it binds to one that already exists — and unlike the afxdp feature it needs no eBPF, no driver support and no special interface configuration. It is the slowest of the three and the one most likely to just work.

(Those modules are named without links here because either may be compiled out while this one is not.)

use pktkit::afpacket::{Config, Socket};
use pktkit::{Frame, L2Device};
use std::sync::Arc;

let dev = Socket::open(Config {
    interface: "eth0".into(),
    promiscuous: true,
    ..Default::default()
})?;

dev.set_handler(Arc::new(|f: &Frame| {
    println!("{:?} -> {:?}", f.src_mac(), f.dst_mac());
    Ok(())
}));

Privileges

Opening an AF_PACKET socket needs CAP_NET_RAW. Without it, Socket::open fails with PermissionDenied.

What you will see

A bound socket receives every frame the interface accepts, including traffic for the host itself, and — with Config::promiscuous set — traffic addressed to other stations. Frames the host sends are also delivered back unless Config::inbound_only is set. Frames written with send go out the interface as-is, so the Ethernet header is yours to fill in.

Platform support

Linux only. On other platforms the type is still present so cross-platform code compiles, but Socket::open returns ErrorKind::Unsupported.

Structs

Config

How to open an Socket.

Socket

An AF_PACKET socket bound to one interface, presented as an L2Device.