// Copyright 2018 Parity Technologies (UK) Ltd.
//
// 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.
use std::{
collections::hash_map::DefaultHasher,
error::Error,
hash::{Hash, Hasher},
time::Duration,
};
use futures::stream::StreamExt;
use libp2p::{
gossipsub,
mdns,
noise,
swarm::{NetworkBehaviour, SwarmEvent},
SwarmBuilder,
tcp, yamux,
};
use tokio::{io, io::AsyncBufReadExt, select};
// We create a custom network behaviour that combines Gossipsub and Mdns.
#[derive(NetworkBehaviour)]
struct MyBehaviour {
gossipsub: gossipsub::Behaviour,
mdns: mdns::tokio::Behaviour,
}
pub fn ensure_identity_from_file() {
let identity_file_path = "~/.mew/identity.json";
let identity = libp2p::identity::Keypair::load(identity_path).unwrap();
return identity;
}
pub async fn start() -> Result<(), Box<dyn Error>> {
let mut swarm = SwarmBuilder::with_new_identity()
.with_tokio()
.with_quic()
.with_behaviour(|key| {
// To content-address message, we can take the hash of message and use it as an ID.
let message_id_fn = |message: &gossipsub::Message| {
let mut s = DefaultHasher::new();
message.data.hash(&mut s);
gossipsub::MessageId::from(s.finish().to_string())
};
// Set a custom gossipsub configuration
let gossipsub_config = gossipsub::ConfigBuilder::default()
.heartbeat_interval(Duration::from_secs(10)) // This is set to aid debugging by not cluttering the log space
.validation_mode(gossipsub::ValidationMode::Strict) // This sets the kind of message validation. The default is Strict (enforce message
// signing)
.message_id_fn(message_id_fn) // content-address messages. No two messages of the same content will be propagated.
.build()
.map_err(|msg| io::Error::new(io::ErrorKind::Other, msg))?; // Temporary hack because `build` does not return a proper `std::error::Error`.
// build a gossipsub network behaviour
let gossipsub = gossipsub::Behaviour::new(
gossipsub::MessageAuthenticity::Signed(key.clone()),
gossipsub_config,
)?;
let mdns = mdns::tokio::Behaviour::new(
mdns::Config::default(),
key.public().to_peer_id()
)?;
Ok(MyBehaviour { gossipsub, mdns })
})?
.build();
// Create a Gossipsub topic
let topic = gossipsub::IdentTopic::new("mew");
// subscribes to our topic
swarm.behaviour_mut().gossipsub.subscribe(&topic)?;
// Read full lines from stdin
let mut stdin = io::BufReader::new(io::stdin()).lines();
// Listen on all interfaces and whatever port the OS assigns
swarm.listen_on("/ip4/0.0.0.0/udp/0/quic-v1".parse()?)?;
println!("Enter messages via STDIN and they will be sent to connected peers using Gossipsub");
// Kick it off
loop {
select! {
Ok(Some(line)) = stdin.next_line() => {
if let Err(e) = swarm
.behaviour_mut().gossipsub
.publish(topic.clone(), line.as_bytes()) {
println!("Publish error: {e:?}");
}
}
event = swarm.select_next_some() => match event {
SwarmEvent::Behaviour(MyBehaviourEvent::Mdns(mdns::Event::Discovered(list))) => {
for (peer_id, _multiaddr) in list {
println!("mDNS discovered a new peer: {peer_id}");
swarm.behaviour_mut().gossipsub.add_explicit_peer(&peer_id);
}
},
SwarmEvent::Behaviour(MyBehaviourEvent::Mdns(mdns::Event::Expired(list))) => {
for (peer_id, _multiaddr) in list {
println!("mDNS discover peer has expired: {peer_id}");
swarm.behaviour_mut().gossipsub.remove_explicit_peer(&peer_id);
}
},
SwarmEvent::Behaviour(MyBehaviourEvent::Gossipsub(gossipsub::Event::Message {
propagation_source: peer_id,
message_id: id,
message,
})) => println!(
"Got message: '{}' with id: {id} from peer: {peer_id}",
String::from_utf8_lossy(&message.data),
),
SwarmEvent::NewListenAddr { address, .. } => {
println!("Local node is listening on {address}");
}
_ => {}
}
}
}
}