lighthouse/beacon_node/eth2-libp2p/src/behaviour.rs
2019-03-26 13:28:21 +11:00

260 lines
8.5 KiB
Rust

use crate::rpc::methods::BlockRootSlot;
use crate::rpc::{RPCEvent, RPCMessage, Rpc};
use crate::NetworkConfig;
use futures::prelude::*;
use libp2p::{
core::{
swarm::{NetworkBehaviourAction, NetworkBehaviourEventProcess},
PublicKey,
},
gossipsub::{Gossipsub, GossipsubEvent},
identify::{protocol::IdentifyInfo, Identify, IdentifyEvent},
ping::{Ping, PingEvent},
tokio_io::{AsyncRead, AsyncWrite},
NetworkBehaviour, PeerId,
};
use slog::{debug, o, warn};
use ssz::{ssz_encode, Decodable, DecodeError, Encodable, SszStream};
use ssz_derive::{Decode, Encode};
use types::Attestation;
use types::{Topic, TopicHash};
/// Builds the network behaviour for the libp2p Swarm.
/// Implements gossipsub message routing.
#[derive(NetworkBehaviour)]
#[behaviour(out_event = "BehaviourEvent", poll_method = "poll")]
pub struct Behaviour<TSubstream: AsyncRead + AsyncWrite> {
/// The routing pub-sub mechanism for eth2.
gossipsub: Gossipsub<TSubstream>,
// TODO: Add Kademlia for peer discovery
/// The events generated by this behaviour to be consumed in the swarm poll.
serenity_rpc: Rpc<TSubstream>,
/// Allows discovery of IP addresses for peers on the network.
identify: Identify<TSubstream>,
/// Keep regular connection to peers and disconnect if absent.
// TODO: Keepalive, likely remove this later.
// TODO: Make the ping time customizeable.
ping: Ping<TSubstream>,
#[behaviour(ignore)]
events: Vec<BehaviourEvent>,
/// Logger for behaviour actions.
#[behaviour(ignore)]
log: slog::Logger,
}
// Implement the NetworkBehaviourEventProcess trait so that we can derive NetworkBehaviour for Behaviour
impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<GossipsubEvent>
for Behaviour<TSubstream>
{
fn inject_event(&mut self, event: GossipsubEvent) {
match event {
GossipsubEvent::Message(gs_msg) => {
debug!(self.log, "Received GossipEvent"; "msg" => format!("{:?}", gs_msg));
let pubsub_message = match PubsubMessage::ssz_decode(&gs_msg.data, 0) {
//TODO: Punish peer on error
Err(e) => {
warn!(
self.log,
"Received undecodable message from Peer {:?} error", gs_msg.source;
"error" => format!("{:?}", e)
);
return;
}
Ok((msg, _index)) => msg,
};
self.events.push(BehaviourEvent::GossipMessage {
source: gs_msg.source,
topics: gs_msg.topics,
message: pubsub_message,
});
}
GossipsubEvent::Subscribed {
peer_id: _,
topic: _,
}
| GossipsubEvent::Unsubscribed {
peer_id: _,
topic: _,
} => {}
}
}
}
impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<RPCMessage>
for Behaviour<TSubstream>
{
fn inject_event(&mut self, event: RPCMessage) {
match event {
RPCMessage::PeerDialed(peer_id) => {
self.events.push(BehaviourEvent::PeerDialed(peer_id))
}
RPCMessage::RPC(peer_id, rpc_event) => {
self.events.push(BehaviourEvent::RPC(peer_id, rpc_event))
}
}
}
}
impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<IdentifyEvent>
for Behaviour<TSubstream>
{
fn inject_event(&mut self, event: IdentifyEvent) {
match event {
IdentifyEvent::Identified {
peer_id, mut info, ..
} => {
if info.listen_addrs.len() > 20 {
debug!(
self.log,
"More than 20 peers have been identified, truncating"
);
info.listen_addrs.truncate(20);
}
self.events.push(BehaviourEvent::Identified(peer_id, info));
}
IdentifyEvent::Error { .. } => {}
IdentifyEvent::SendBack { .. } => {}
}
}
}
impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<PingEvent>
for Behaviour<TSubstream>
{
fn inject_event(&mut self, _event: PingEvent) {
// not interested in ping responses at the moment.
}
}
impl<TSubstream: AsyncRead + AsyncWrite> Behaviour<TSubstream> {
pub fn new(local_public_key: PublicKey, net_conf: &NetworkConfig, log: &slog::Logger) -> Self {
let local_peer_id = local_public_key.clone().into_peer_id();
let identify_config = net_conf.identify_config.clone();
let behaviour_log = log.new(o!());
Behaviour {
gossipsub: Gossipsub::new(local_peer_id, net_conf.gs_config.clone()),
serenity_rpc: Rpc::new(log),
identify: Identify::new(
identify_config.version,
identify_config.user_agent,
local_public_key,
),
ping: Ping::new(),
events: Vec::new(),
log: behaviour_log,
}
}
/// Consumes the events list when polled.
fn poll<TBehaviourIn>(
&mut self,
) -> Async<NetworkBehaviourAction<TBehaviourIn, BehaviourEvent>> {
if !self.events.is_empty() {
return Async::Ready(NetworkBehaviourAction::GenerateEvent(self.events.remove(0)));
}
Async::NotReady
}
}
/// Implements the combined behaviour for the libp2p service.
impl<TSubstream: AsyncRead + AsyncWrite> Behaviour<TSubstream> {
/// Subscribes to a gossipsub topic.
pub fn subscribe(&mut self, topic: Topic) -> bool {
self.gossipsub.subscribe(topic)
}
/// Sends an RPC Request/Response via the RPC protocol.
pub fn send_rpc(&mut self, peer_id: PeerId, rpc_event: RPCEvent) {
self.serenity_rpc.send_rpc(peer_id, rpc_event);
}
/// Publishes a message on the pubsub (gossipsub) behaviour.
pub fn publish(&mut self, topics: Vec<Topic>, message: PubsubMessage) {
let message_bytes = ssz_encode(&message);
for topic in topics {
self.gossipsub.publish(topic, message_bytes.clone());
}
}
}
/// The types of events than can be obtained from polling the behaviour.
pub enum BehaviourEvent {
RPC(PeerId, RPCEvent),
PeerDialed(PeerId),
Identified(PeerId, IdentifyInfo),
// TODO: This is a stub at the moment
GossipMessage {
source: PeerId,
topics: Vec<TopicHash>,
message: PubsubMessage,
},
}
/// Messages that are passed to and from the pubsub (Gossipsub) behaviour.
#[derive(Debug, Clone, PartialEq)]
pub enum PubsubMessage {
/// Gossipsub message providing notification of a new block.
Block(BlockRootSlot),
/// Gossipsub message providing notification of a new attestation.
Attestation(Attestation),
}
//TODO: Correctly encode/decode enums. Prefixing with integer for now.
impl Encodable for PubsubMessage {
fn ssz_append(&self, s: &mut SszStream) {
match self {
PubsubMessage::Block(block_gossip) => {
0u32.ssz_append(s);
block_gossip.ssz_append(s);
}
PubsubMessage::Attestation(attestation_gossip) => {
1u32.ssz_append(s);
attestation_gossip.ssz_append(s);
}
}
}
}
impl Decodable for PubsubMessage {
fn ssz_decode(bytes: &[u8], index: usize) -> Result<(Self, usize), DecodeError> {
let (id, index) = u32::ssz_decode(bytes, index)?;
match id {
0 => {
let (block, index) = BlockRootSlot::ssz_decode(bytes, index)?;
Ok((PubsubMessage::Block(block), index))
}
1 => {
let (attestation, index) = Attestation::ssz_decode(bytes, index)?;
Ok((PubsubMessage::Attestation(attestation), index))
}
_ => Err(DecodeError::Invalid),
}
}
}
#[cfg(test)]
mod test {
use super::*;
use types::*;
#[test]
fn ssz_encoding() {
let original = PubsubMessage::Block(BlockRootSlot {
block_root: Hash256::from_slice(&[42; 32]),
slot: Slot::new(4),
});
let encoded = ssz_encode(&original);
println!("{:?}", encoded);
let (decoded, _i) = PubsubMessage::ssz_decode(&encoded, 0).unwrap();
assert_eq!(original, decoded);
}
}