AFXDP-rs

This module provides a Rust interface for AF_XDP built on libbpf-sys (https://github.com/alexforster/libbpf-sys).

AF_XDP:

• https://www.kernel.org/doc/html/latest/networking/af_xdp.html
• https://lwn.net/Articles/750845/

The goals of this crate, in order, are:

1. Correctness
2. Performance
3. Ease of use

Current Status

The API works for my current use cases but I expect it will change to achieve higher performance and usability.

If you have knowledge of Rust FFI and general Rust unsafe things I would greatly appreciate some help auditing this crate as my experience in this area is limited.

AF_XDP Features

• HUGE TLB: At present this module always uses HUGETLB to map the memory.
• ZEROCOPY: At present this module always passes the ZEROCOPY flag which only works with a small number of drivers.
• Only the chunked memory mode is supported.

Notes

• At present the build will fail using cargo build. To avoid this, checkout libbpf-sys, download the Git submodule for libbpf, edit the Makefile in libbpf/src/, add -fPIC to the CFLAGS and rebuild libbpf-sys. Then add the path parameter to Cargo.toml in this module to point to the libbpf-sys directory.

toml libbpf-sys = { version = "0.0.6-4", path = "/home/dan/projects/rust/libbpf-sys" }

To Do

• Currently this module is not 'safe' because Bufs can outlive the memory pool they are associated with. I believe fixing this will require adding an Arc to each Buf. I have not had the time yet to determine the performance impact of this and would appreciate any other ideas.
• Allow more configurability of AF XDP features.