main.rs

// Copyright 2023 Protocol Labs.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

#![doc = include_str!("../README.md")]

use futures::prelude::*;
use libp2p::core::upgrade::Version;
use libp2p::{
    identity, noise,
    swarm::{SwarmBuilder, SwarmEvent},
    tcp, upnp, yamux, Multiaddr, PeerId, Transport,
};
use std::error::Error;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    let local_key = identity::Keypair::generate_ed25519();
    let local_peer_id = PeerId::from(local_key.public());
    println!("Local peer id: {local_peer_id:?}");

    let transport = tcp::tokio::Transport::default()
        .upgrade(Version::V1Lazy)
        .authenticate(noise::Config::new(&local_key)?)
        .multiplex(yamux::Config::default())
        .boxed();

    let mut swarm = SwarmBuilder::with_tokio_executor(
        transport,
        upnp::tokio::Behaviour::default(),
        local_peer_id,
    )
    .build();

    // Tell the swarm to listen on all interfaces and a random, OS-assigned
    // port.
    swarm.listen_on("/ip4/0.0.0.0/tcp/0".parse()?)?;

    // Dial the peer identified by the multi-address given as the second
    // command-line argument, if any.
    if let Some(addr) = std::env::args().nth(1) {
        let remote: Multiaddr = addr.parse()?;
        swarm.dial(remote)?;
        println!("Dialed {addr}")
    }

    loop {
        match swarm.select_next_some().await {
            SwarmEvent::NewListenAddr { address, .. } => println!("Listening on {address:?}"),
            SwarmEvent::Behaviour(upnp::Event::NewExternalAddr(addr)) => {
                println!("New external address: {addr}");
            }
            SwarmEvent::Behaviour(upnp::Event::GatewayNotFound) => {
                println!("Gateway does not support UPnP");
                break;
            }
            SwarmEvent::Behaviour(upnp::Event::NonRoutableGateway) => {
                println!("Gateway is not exposed directly to the public Internet, i.e. it itself has a private IP address.");
                break;
            }
            _ => {}
        }
    }
    Ok(())
}