Rust crate for linux L2TP netlink management

To add a tunnel

use std::net::Ipv4Addr;

use nl_l2tp::L2tpTunnel;

async fn add_l2tp_tunnel() -> Result<(), Box<dyn std::error::Error>> {
    let (conn, mut handle, _) = nl_l2tp::new_connection()?;
    tokio::spawn(conn);

    let mut config = L2tpTunnel::new(1000);
    config.peer_tunnel_id = Some(2000);
    config.local = Some(Ipv4Addr::new(10, 0, 0, 1).into());
    config.peer = Some(Ipv4Addr::new(10, 0, 0, 2).into());
    config.local_udp_port = Some(1701);
    config.peer_udp_port = Some(1702);
    handle.add_tunnel(&config).await?;
    Ok(())
}

To list all tunnels

L2tpHandle::get_tunnels() returns one L2tpTunnel per tunnel:

use nl_l2tp::L2tpTunnel;

async fn show_l2tp_tunnels() -> Result<(), Box<dyn std::error::Error>> {
    let (conn, mut handle, _) = nl_l2tp::new_connection()?;
    tokio::spawn(conn);

    for tunnel in handle.get_tunnels(&L2tpTunnel::default()).await? {
        println!("{tunnel:?}");
    }
    Ok(())
}

To delete a tunnel

A tunnel is identified by its local tunnel ID, L2tpTunnel::new() sets it:

use nl_l2tp::L2tpTunnel;

async fn delete_l2tp_tunnel() -> Result<(), Box<dyn std::error::Error>> {
    let (conn, mut handle, _) = nl_l2tp::new_connection()?;
    tokio::spawn(conn);

    handle.delete_tunnel(&L2tpTunnel::new(1000)).await?;
    Ok(())
}

Notes

• L2tpTunnel::new(tunnel_id) creates a UDP tunnel config, the encapsulation of ip l2tp add tunnel.
• A UDP tunnel needs local_udp_port and peer_udp_port, an IP tunnel must not set them.
• Use L2tpSession and L2tpHandle::add_session(), L2tpHandle::get_sessions() and L2tpHandle::delete_session() to manage the sessions of a tunnel.

License: MIT