nlink-macros

Procedural-macro derives + attribute macros for the nlink Linux netlink library. Lets downstream code declare a complete Generic Netlink family — marker struct, typed command enum, typed attribute-kind enums, typed message bodies, and the full request/response round-trip — in ~30 lines of declarative code.

Don't depend on this directly

Add nlink to your Cargo.toml; it re-exports everything from this crate under nlink::macros::*:

[dependencies]
nlink = "0.16"

use nlink::macros::*;          // pulls in every macro + the traits
use nlink::netlink::Connection;

You only need to depend on nlink-macros directly if you're building a library that exposes the macros to its downstream without dragging in the full nlink runtime.

What it ships

Macro	Replaces
`#[genl_family(name = "...", version = N)]`	Family marker struct + `ProtocolState` + `AsyncProtocolInit` + sealed-trait impls + `family_id` field/getter + `GenlFamily` impl
`#[derive(GenlCommand)]` + `#[genl_command(repr = "u8"\|"u16")]`	Typed GENL command enum — `From<MyCmd> for u8` + `TryFrom<u8> for MyCmd`
`#[derive(GenlAttribute)]` + `#[genl_attribute(repr = "u8"\|"u16")]`	Typed attribute-kind enum
`#[derive(GenlEnum)]` + `#[genl_enum(repr = "u8"\|"u16"\|"u32")]`	Typed value enum encoded inside an attribute payload
`#[derive(GenlMessage)]` + `#[genl_message(cmd = ...)]`	Typed request/response body with per-field `#[genl_attr(...)]`

#[derive(NetlinkAttrs)] for nested attribute groups is a tracked follow-up (the marker trait is defined in nlink::macros::NetlinkAttrs already so hand-implementations work today).

Quick taste

use nlink::macros::*;
use nlink::netlink::Connection;

#[genl_family(name = "TASKSTATS", version = 1)]
pub struct Taskstats;

#[derive(GenlCommand, Debug, Clone, Copy)]
#[genl_command(repr = "u8")]
pub enum TaskstatsCmd { Unspec = 0, Get = 1, New = 2 }

#[derive(GenlAttribute, Debug, Clone, Copy)]
#[genl_attribute(repr = "u16")]
pub enum TaskstatsCmdAttr { Pid = 1, Tgid = 2 }

#[derive(GenlMessage, Debug, Default)]
#[genl_message(cmd = TaskstatsCmd::Get)]
pub struct TaskstatsGet {
    #[genl_attr(TaskstatsCmdAttr::Pid)] pub pid: u32,
}

#[derive(GenlMessage, Debug, Default)]
#[genl_message(cmd = TaskstatsCmd::New)]
pub struct TaskstatsReply {
    #[genl_attr(TaskstatsCmdAttr::Pid)]  pub pid: u32,
    #[genl_attr(TaskstatsCmdAttr::Tgid)] pub tgid: u32,
}

#[tokio::main]
async fn main() -> nlink::Result<()> {
    let conn = Connection::<Taskstats>::new_async().await?;
    let reply: TaskstatsReply =
        conn.send_typed(TaskstatsGet { pid: std::process::id() }).await?;
    println!("pid={} tgid={}", reply.pid, reply.tgid);
    Ok(())
}

See docs/recipes/define-your-own-genl-family.md for the narrative walkthrough and crates/nlink/examples/macros/define_taskstats.rs for the runnable end-to-end version.

Versioning & publish order

nlink-macros is published to crates.io independently of nlink but they version in lockstep — version X.Y.Z of nlink depends on the matching X.Y.Z of nlink-macros. When cutting a release:

Bump both crates' versions.
cargo publish -p nlink-macros first.
Wait ~30s for crates.io to index.
cargo publish -p nlink.

nlink's Cargo.toml pins nlink-macros with a version = "..." in addition to the path dep — this is required for cargo publish nlink to resolve the dep on crates.io. Publishing nlink before nlink-macros will fail with "no matching version found."

MSRV

Matches nlink proper: Rust 1.95 as of 0.16.

License

Dual-licensed under MIT OR Apache-2.0, matching nlink. See the root LICENSE-* files.