Ethereum 2.0 Network Specification Upgrade (#510)

Updates lighthouse to the latest networking spec

-  Sync re-write (#496)
-  Updates to the latest eth2 networking spec (#495)
-  Libp2p updates and improvements

beacon_node/eth2-libp2p/src/behaviour.rs

@@ -1,3 +1,4 @@
+use crate::config::*;
 use crate::discovery::Discovery;
 use crate::rpc::{RPCEvent, RPCMessage, RPC};
 use crate::{error, NetworkConfig};
@@ -15,7 +16,6 @@ use libp2p::{
     NetworkBehaviour, PeerId,
 };
 use slog::{debug, o, trace};
-use ssz::{ssz_encode, Encode};
 use std::num::NonZeroU32;
 use std::time::Duration;
 
@@ -91,7 +91,7 @@ impl<TSubstream: AsyncRead + AsyncWrite> NetworkBehaviourEventProcess<GossipsubE
     fn inject_event(&mut self, event: GossipsubEvent) {
         match event {
             GossipsubEvent::Message(gs_msg) => {
-                trace!(self.log, "Received GossipEvent"; "msg" => format!("{:?}", gs_msg));
+                trace!(self.log, "Received GossipEvent");
 
                 let msg = PubsubMessage::from_topics(&gs_msg.topics, gs_msg.data);
 
@@ -192,10 +192,10 @@ impl<TSubstream: AsyncRead + AsyncWrite> Behaviour<TSubstream> {
     }
 
     /// Publishes a message on the pubsub (gossipsub) behaviour.
-    pub fn publish(&mut self, topics: Vec<Topic>, message: PubsubMessage) {
-        let message_bytes = ssz_encode(&message);
+    pub fn publish(&mut self, topics: &[Topic], message: PubsubMessage) {
+        let message_data = message.to_data();
         for topic in topics {
-            self.gossipsub.publish(topic, message_bytes.clone());
+            self.gossipsub.publish(topic, message_data.clone());
         }
     }
 
@@ -224,13 +224,20 @@ pub enum BehaviourEvent {
     },
 }
 
-/// Messages that are passed to and from the pubsub (Gossipsub) behaviour.
+/// Messages that are passed to and from the pubsub (Gossipsub) behaviour. These are encoded and
+/// decoded upstream.
 #[derive(Debug, Clone, PartialEq)]
 pub enum PubsubMessage {
     /// Gossipsub message providing notification of a new block.
     Block(Vec<u8>),
     /// Gossipsub message providing notification of a new attestation.
     Attestation(Vec<u8>),
+    /// Gossipsub message providing notification of a voluntary exit.
+    VoluntaryExit(Vec<u8>),
+    /// Gossipsub message providing notification of a new proposer slashing.
+    ProposerSlashing(Vec<u8>),
+    /// Gossipsub message providing notification of a new attester slashing.
+    AttesterSlashing(Vec<u8>),
     /// Gossipsub message from an unknown topic.
     Unknown(Vec<u8>),
 }
@@ -244,29 +251,33 @@ impl PubsubMessage {
      */
     fn from_topics(topics: &Vec<TopicHash>, data: Vec<u8>) -> Self {
         for topic in topics {
-            match topic.as_str() {
-                BEACON_BLOCK_TOPIC => return PubsubMessage::Block(data),
-                BEACON_ATTESTATION_TOPIC => return PubsubMessage::Attestation(data),
-                _ => {}
+            // compare the prefix and postfix, then match on the topic
+            let topic_parts: Vec<&str> = topic.as_str().split('/').collect();
+            if topic_parts.len() == 4
+                && topic_parts[1] == TOPIC_PREFIX
+                && topic_parts[3] == TOPIC_ENCODING_POSTFIX
+            {
+                match topic_parts[2] {
+                    BEACON_BLOCK_TOPIC => return PubsubMessage::Block(data),
+                    BEACON_ATTESTATION_TOPIC => return PubsubMessage::Attestation(data),
+                    VOLUNTARY_EXIT_TOPIC => return PubsubMessage::VoluntaryExit(data),
+                    PROPOSER_SLASHING_TOPIC => return PubsubMessage::ProposerSlashing(data),
+                    ATTESTER_SLASHING_TOPIC => return PubsubMessage::AttesterSlashing(data),
+                    _ => {}
+                }
             }
         }
         PubsubMessage::Unknown(data)
     }
-}
 
-impl Encode for PubsubMessage {
-    fn is_ssz_fixed_len() -> bool {
-        false
-    }
-
-    fn ssz_append(&self, buf: &mut Vec<u8>) {
+    fn to_data(self) -> Vec<u8> {
         match self {
-            PubsubMessage::Block(inner)
-            | PubsubMessage::Attestation(inner)
-            | PubsubMessage::Unknown(inner) => {
-                // Encode the gossip as a Vec<u8>;
-                buf.append(&mut inner.as_ssz_bytes());
-            }
+            PubsubMessage::Block(data)
+            | PubsubMessage::Attestation(data)
+            | PubsubMessage::VoluntaryExit(data)
+            | PubsubMessage::ProposerSlashing(data)
+            | PubsubMessage::AttesterSlashing(data)
+            | PubsubMessage::Unknown(data) => data,
         }
     }
 }