Rename libp2p to eth2-libp2p

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

@@ -0,0 +1,181 @@
+use super::methods::{HelloMessage, RPCMethod, RPCRequest, RPCResponse};
+use libp2p::core::{upgrade, InboundUpgrade, OutboundUpgrade, UpgradeInfo};
+use ssz::{ssz_encode, Decodable, Encodable, SszStream};
+use std::io;
+use std::iter;
+use tokio::io::{AsyncRead, AsyncWrite};
+
+/// The maximum bytes that can be sent across the RPC.
+const MAX_READ_SIZE: usize = 2048;
+
+/// Implementation of the `ConnectionUpgrade` for the rpc protocol.
+
+#[derive(Debug, Clone)]
+pub struct RPCProtocol;
+
+impl UpgradeInfo for RPCProtocol {
+    type Info = &'static [u8];
+    type InfoIter = iter::Once<Self::Info>;
+
+    #[inline]
+    fn protocol_info(&self) -> Self::InfoIter {
+        iter::once(b"/eth/serenity/rpc/1.0.0")
+    }
+}
+
+impl Default for RPCProtocol {
+    fn default() -> Self {
+        RPCProtocol
+    }
+}
+
+/// The RPC types which are sent/received in this protocol.
+#[derive(Debug, Clone)]
+pub enum RPCEvent {
+    Request {
+        id: u64,
+        method_id: u16,
+        body: RPCRequest,
+    },
+    Response {
+        id: u64,
+        method_id: u16, //TODO: Remove and process decoding upstream
+        result: RPCResponse,
+    },
+}
+
+impl UpgradeInfo for RPCEvent {
+    type Info = &'static [u8];
+    type InfoIter = iter::Once<Self::Info>;
+
+    #[inline]
+    fn protocol_info(&self) -> Self::InfoIter {
+        iter::once(b"/eth/serenity/rpc/1.0.0")
+    }
+}
+
+impl<TSocket> InboundUpgrade<TSocket> for RPCProtocol
+where
+    TSocket: AsyncRead + AsyncWrite,
+{
+    type Output = RPCEvent;
+    type Error = DecodeError;
+    type Future =
+        upgrade::ReadOneThen<TSocket, (), fn(Vec<u8>, ()) -> Result<RPCEvent, DecodeError>>;
+
+    fn upgrade_inbound(self, socket: TSocket, _: Self::Info) -> Self::Future {
+        upgrade::read_one_then(socket, MAX_READ_SIZE, (), |packet, ()| Ok(decode(packet)?))
+    }
+}
+
+fn decode(packet: Vec<u8>) -> Result<RPCEvent, DecodeError> {
+    // decode the header of the rpc
+    // request/response
+    let (request, index) = bool::ssz_decode(&packet, 0)?;
+    let (id, index) = u64::ssz_decode(&packet, index)?;
+    let (method_id, index) = u16::ssz_decode(&packet, index)?;
+
+    if request {
+        let body = match RPCMethod::from(method_id) {
+            RPCMethod::Hello => {
+                let (hello_body, _index) = HelloMessage::ssz_decode(&packet, index)?;
+                RPCRequest::Hello(hello_body)
+            }
+            RPCMethod::Unknown | _ => return Err(DecodeError::UnknownRPCMethod),
+        };
+
+        Ok(RPCEvent::Request {
+            id,
+            method_id,
+            body,
+        })
+    }
+    // we have received a response
+    else {
+        let result = match RPCMethod::from(method_id) {
+            RPCMethod::Hello => {
+                let (body, _index) = HelloMessage::ssz_decode(&packet, index)?;
+                RPCResponse::Hello(body)
+            }
+            RPCMethod::Unknown | _ => return Err(DecodeError::UnknownRPCMethod),
+        };
+        Ok(RPCEvent::Response {
+            id,
+            method_id,
+            result,
+        })
+    }
+}
+
+impl<TSocket> OutboundUpgrade<TSocket> for RPCEvent
+where
+    TSocket: AsyncWrite,
+{
+    type Output = ();
+    type Error = io::Error;
+    type Future = upgrade::WriteOne<TSocket>;
+
+    #[inline]
+    fn upgrade_outbound(self, socket: TSocket, _: Self::Info) -> Self::Future {
+        let bytes = ssz_encode(&self);
+        upgrade::write_one(socket, bytes)
+    }
+}
+
+impl Encodable for RPCEvent {
+    fn ssz_append(&self, s: &mut SszStream) {
+        match self {
+            RPCEvent::Request {
+                id,
+                method_id,
+                body,
+            } => {
+                s.append(&true);
+                s.append(id);
+                s.append(method_id);
+                match body {
+                    RPCRequest::Hello(body) => {
+                        s.append(body);
+                    }
+                    _ => {}
+                }
+            }
+            RPCEvent::Response {
+                id,
+                method_id,
+                result,
+            } => {
+                s.append(&false);
+                s.append(id);
+                s.append(method_id);
+                match result {
+                    RPCResponse::Hello(response) => {
+                        s.append(response);
+                    }
+                    _ => {}
+                }
+            }
+        }
+    }
+}
+
+#[derive(Debug)]
+pub enum DecodeError {
+    ReadError(upgrade::ReadOneError),
+    SSZDecodeError(ssz::DecodeError),
+    UnknownRPCMethod,
+}
+
+impl From<upgrade::ReadOneError> for DecodeError {
+    #[inline]
+    fn from(err: upgrade::ReadOneError) -> Self {
+        DecodeError::ReadError(err)
+    }
+}
+
+impl From<ssz::DecodeError> for DecodeError {
+    #[inline]
+    fn from(err: ssz::DecodeError) -> Self {
+        DecodeError::SSZDecodeError(err)
+    }
+}