Add basic Gossip sync handlers

beacon_node/eth2-libp2p/src/rpc/methods.rs

@@ -1,7 +1,7 @@
 use ssz::{Decodable, DecodeError, Encodable, SszStream};
 /// Available RPC methods types and ids.
 use ssz_derive::{Decode, Encode};
-use types::{BeaconBlockBody, BeaconBlockHeader, Epoch, Hash256, Slot};
+use types::{Attestation, BeaconBlockBody, BeaconBlockHeader, Epoch, Hash256, Slot};
 
 #[derive(Debug)]
 /// Available Serenity Libp2p RPC methods
@@ -97,6 +97,12 @@ impl RPCResponse {
     }
 }
 
+#[derive(Debug, Clone)]
+pub enum IncomingGossip {
+    Block(BlockGossip),
+    Attestation(AttestationGossip),
+}
+
 /* Request/Response data structures for RPC methods */
 
 /// The HELLO request/response handshake message.
@@ -236,3 +242,15 @@ pub struct BeaconChainStateResponse {
     /// The values corresponding the to the requested tree hashes.
     pub values: bool, //TBD - stubbed with encodeable bool
 }
+
+/// Gossipsub message providing notification of a new block.
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
+pub struct BlockGossip {
+    pub root: BlockRootSlot,
+}
+
+/// Gossipsub message providing notification of a new attestation.
+#[derive(Encode, Decode, Clone, Debug, PartialEq)]
+pub struct AttestationGossip {
+    pub attestation: Attestation,
+}