Initial Libp2p RPC implementation.

beacon_node/libp2p/src/rpc/methods.rs

@@ -0,0 +1,38 @@
+/// Available RPC methods types and ids.
+use ssz_derive::{Decode, Encode};
+use types::{Epoch, Hash256, Slot};
+
+#[derive(Debug)]
+pub enum RPCMethod {
+    Hello,
+    Unknown,
+}
+
+impl From<u16> for RPCMethod {
+    fn from(method_id: u16) -> Self {
+        match method_id {
+            0 => RPCMethod::Hello,
+            _ => RPCMethod::Unknown,
+        }
+    }
+}
+
+#[derive(Debug, Clone)]
+pub enum RPCRequest {
+    HelloRequest,
+}
+
+#[derive(Debug, Clone)]
+pub enum RPCResponse {
+    HelloResponse(HelloResponse),
+}
+
+// request/response structs for RPC methods
+#[derive(Encode, Decode, Clone, Debug)]
+pub struct HelloResponse {
+    pub network_id: u8,
+    pub latest_finalized_root: Hash256,
+    pub latest_finalized_epoch: Epoch,
+    pub best_root: Hash256,
+    pub best_slot: Slot,
+}