lighthouse/beacon_node/eth2-libp2p/src/service.rs
2019-07-16 23:26:31 +10:00

243 lines
9.1 KiB
Rust

use crate::behaviour::{Behaviour, BehaviourEvent, PubsubMessage};
use crate::error;
use crate::multiaddr::Protocol;
use crate::rpc::RPCEvent;
use crate::NetworkConfig;
use crate::{TopicBuilder, TopicHash};
use crate::{BEACON_ATTESTATION_TOPIC, BEACON_PUBSUB_TOPIC};
use futures::prelude::*;
use futures::Stream;
use libp2p::core::{
identity::Keypair,
multiaddr::Multiaddr,
muxing::StreamMuxerBox,
nodes::Substream,
transport::boxed::Boxed,
upgrade::{InboundUpgradeExt, OutboundUpgradeExt},
};
use libp2p::{core, secio, PeerId, Swarm, Transport};
use slog::{debug, info, trace, warn};
use std::fs::File;
use std::io::prelude::*;
use std::io::{Error, ErrorKind};
use std::time::Duration;
type Libp2pStream = Boxed<(PeerId, StreamMuxerBox), Error>;
type Libp2pBehaviour = Behaviour<Substream<StreamMuxerBox>>;
const NETWORK_KEY_FILENAME: &str = "key";
/// The configuration and state of the libp2p components for the beacon node.
pub struct Service {
/// The libp2p Swarm handler.
//TODO: Make this private
pub swarm: Swarm<Libp2pStream, Libp2pBehaviour>,
/// This node's PeerId.
_local_peer_id: PeerId,
/// The libp2p logger handle.
pub log: slog::Logger,
}
impl Service {
pub fn new(config: NetworkConfig, log: slog::Logger) -> error::Result<Self> {
debug!(log, "Network-libp2p Service starting");
// load the private key from CLI flag, disk or generate a new one
let local_private_key = load_private_key(&config, &log);
let local_peer_id = PeerId::from(local_private_key.public());
info!(log, "Local peer id: {:?}", local_peer_id);
let mut swarm = {
// Set up the transport - tcp/ws with secio and mplex/yamux
let transport = build_transport(local_private_key.clone());
// Lighthouse network behaviour
let behaviour = Behaviour::new(&local_private_key, &config, &log)?;
Swarm::new(transport, behaviour, local_peer_id.clone())
};
// listen on the specified address
let listen_multiaddr = {
let mut m = Multiaddr::from(config.listen_address);
m.push(Protocol::Tcp(config.libp2p_port));
m
};
match Swarm::listen_on(&mut swarm, listen_multiaddr.clone()) {
Ok(_) => {
let mut log_address = listen_multiaddr;
log_address.push(Protocol::P2p(local_peer_id.clone().into()));
info!(log, "Listening on: {}", log_address);
}
Err(err) => warn!(
log,
"Cannot listen on: {} because: {:?}", listen_multiaddr, err
),
};
// subscribe to default gossipsub topics
let mut topics = vec![];
//TODO: Handle multiple shard attestations. For now we simply use a separate topic for
//attestations
topics.push(BEACON_ATTESTATION_TOPIC.to_string());
topics.push(BEACON_PUBSUB_TOPIC.to_string());
topics.append(&mut config.topics.clone());
let mut subscribed_topics = vec![];
for topic in topics {
let t = TopicBuilder::new(topic.clone()).build();
if swarm.subscribe(t) {
trace!(log, "Subscribed to topic: {:?}", topic);
subscribed_topics.push(topic);
} else {
warn!(log, "Could not subscribe to topic: {:?}", topic)
}
}
info!(log, "Subscribed to topics: {:?}", subscribed_topics);
Ok(Service {
_local_peer_id: local_peer_id,
swarm,
log,
})
}
}
impl Stream for Service {
type Item = Libp2pEvent;
type Error = crate::error::Error;
fn poll(&mut self) -> Poll<Option<Self::Item>, Self::Error> {
loop {
match self.swarm.poll() {
//Behaviour events
Ok(Async::Ready(Some(event))) => match event {
// TODO: Stub here for debugging
BehaviourEvent::GossipMessage {
source,
topics,
message,
} => {
trace!(self.log, "Pubsub message received: {:?}", message);
return Ok(Async::Ready(Some(Libp2pEvent::PubsubMessage {
source,
topics,
message,
})));
}
BehaviourEvent::RPC(peer_id, event) => {
return Ok(Async::Ready(Some(Libp2pEvent::RPC(peer_id, event))));
}
BehaviourEvent::PeerDialed(peer_id) => {
return Ok(Async::Ready(Some(Libp2pEvent::PeerDialed(peer_id))));
}
BehaviourEvent::PeerDisconnected(peer_id) => {
return Ok(Async::Ready(Some(Libp2pEvent::PeerDisconnected(peer_id))));
}
},
Ok(Async::Ready(None)) => unreachable!("Swarm stream shouldn't end"),
Ok(Async::NotReady) => break,
_ => break,
}
}
Ok(Async::NotReady)
}
}
/// The implementation supports TCP/IP, WebSockets over TCP/IP, secio as the encryption layer, and
/// mplex or yamux as the multiplexing layer.
fn build_transport(local_private_key: Keypair) -> Boxed<(PeerId, StreamMuxerBox), Error> {
// TODO: The Wire protocol currently doesn't specify encryption and this will need to be customised
// in the future.
let transport = libp2p::tcp::TcpConfig::new();
let transport = libp2p::dns::DnsConfig::new(transport);
#[cfg(feature = "libp2p-websocket")]
let transport = {
let trans_clone = transport.clone();
transport.or_transport(websocket::WsConfig::new(trans_clone))
};
transport
.with_upgrade(secio::SecioConfig::new(local_private_key))
.and_then(move |out, endpoint| {
let peer_id = out.remote_key.into_peer_id();
let peer_id2 = peer_id.clone();
let upgrade = core::upgrade::SelectUpgrade::new(
libp2p::yamux::Config::default(),
libp2p::mplex::MplexConfig::new(),
)
// TODO: use a single `.map` instead of two maps
.map_inbound(move |muxer| (peer_id, muxer))
.map_outbound(move |muxer| (peer_id2, muxer));
core::upgrade::apply(out.stream, upgrade, endpoint)
.map(|(id, muxer)| (id, core::muxing::StreamMuxerBox::new(muxer)))
})
.with_timeout(Duration::from_secs(20))
.map_err(|err| Error::new(ErrorKind::Other, err))
.boxed()
}
/// Events that can be obtained from polling the Libp2p Service.
pub enum Libp2pEvent {
/// An RPC response request has been received on the swarm.
RPC(PeerId, RPCEvent),
/// Initiated the connection to a new peer.
PeerDialed(PeerId),
/// A peer has disconnected.
PeerDisconnected(PeerId),
/// Received pubsub message.
PubsubMessage {
source: PeerId,
topics: Vec<TopicHash>,
message: Box<PubsubMessage>,
},
}
/// Loads a private key from disk. If this fails, a new key is
/// generated and is then saved to disk.
///
/// Currently only secp256k1 keys are allowed, as these are the only keys supported by discv5.
fn load_private_key(config: &NetworkConfig, log: &slog::Logger) -> Keypair {
// TODO: Currently using secp256k1 keypairs - currently required for discv5
// check for key from disk
let network_key_f = config.network_dir.join(NETWORK_KEY_FILENAME);
if let Ok(mut network_key_file) = File::open(network_key_f.clone()) {
let mut key_bytes: Vec<u8> = Vec::with_capacity(36);
match network_key_file.read_to_end(&mut key_bytes) {
Err(_) => debug!(log, "Could not read network key file"),
Ok(_) => {
// only accept secp256k1 keys for now
if let Ok(secret_key) =
libp2p::core::identity::secp256k1::SecretKey::from_bytes(&mut key_bytes)
{
let kp: libp2p::core::identity::secp256k1::Keypair = secret_key.into();
debug!(log, "Loaded network key from disk.");
return Keypair::Secp256k1(kp);
} else {
debug!(log, "Network key file is not a valid secp256k1 key");
}
}
}
}
// if a key could not be loaded from disk, generate a new one and save it
let local_private_key = Keypair::generate_secp256k1();
if let Keypair::Secp256k1(key) = local_private_key.clone() {
let _ = std::fs::create_dir_all(&config.network_dir);
match File::create(network_key_f.clone())
.and_then(|mut f| f.write_all(&key.secret().to_bytes()))
{
Ok(_) => {
debug!(log, "New network key generated and written to disk");
}
Err(e) => {
warn!(
log,
"Could not write node key to file: {:?}. Error: {}", network_key_f, e
);
}
}
}
local_private_key
}