Allow plugins to send custom messages

src/neo/Network/P2P/MessageCommand.cs

@@ -40,6 +40,8 @@ public enum MessageCommand : byte
  Block = 0x2c,
  [ReflectionCache(typeof(ConsensusPayload))]
  Consensus = 0x2d,
+ [ReflectionCache(typeof(PluginPayload))]
+ Plugin = 0x2e,
  Reject = 0x2f,
 
  //SPV protocol

src/neo/Network/P2P/Payloads/PluginPayload.cs

@@ -0,0 +1,110 @@
+using Neo.IO;
+using Neo.Ledger;
+using Neo.Persistence;
+using Neo.SmartContract;
+using Neo.SmartContract.Native;
+using Neo.SmartContract.Native.Designate;
+using System;
+using System.IO;
+
+namespace Neo.Network.P2P.Payloads
+{
+ public class PluginPayload : IVerifiable
+ {
+ public string Plugin;
+ public byte MessageType;
+ public byte[] Data;
+ public PluginPayloadRole WitnessRole;
+ public Witness Witness;
+
+ private UInt256 _hash = null;
+ public UInt256 Hash
+ {
+ get
+ {
+ if (_hash == null)
+ {
+ _hash = this.CalculateHash();
+ }
+ return _hash;
+ }
+ }
+
+ public int Size =>
+ Plugin.GetVarSize() + //Plugin
+ sizeof(byte) + //MessageType
+ sizeof(PluginPayloadRole) + //WitnessRole
+ Data.GetVarSize() + //Data
+ 1 + Witness.Size; //Witness
+
+ Witness[] IVerifiable.Witnesses
+ {
+ get
+ {
+ return new[] { Witness };
+ }
+ set
+ {
+ if (value.Length != 1) throw new ArgumentException();
+ Witness = value[0];
+ }
+ }
+
+ void ISerializable.Deserialize(BinaryReader reader)
+ {
+ ((IVerifiable)this).DeserializeUnsigned(reader);
+ if (reader.ReadByte() != 1) throw new FormatException();
+ Witness = reader.ReadSerializable<Witness>();
+ }
+
+ void IVerifiable.DeserializeUnsigned(BinaryReader reader)
+ {
+ Plugin = reader.ReadVarString(32);
+ MessageType = reader.ReadByte();
+ Data = reader.ReadVarBytes(ushort.MaxValue);
+ WitnessRole = (PluginPayloadRole)reader.ReadByte();
+ if (!Enum.IsDefined(typeof(PluginPayloadRole), WitnessRole)) throw new FormatException();
+ }
+
+ UInt160[] IVerifiable.GetScriptHashesForVerifying(StoreView snapshot)
+ {
+ switch (WitnessRole)
+ {
+ case PluginPayloadRole.Committee:
+ {
+ return new[] { NativeContract.NEO.GetCommitteeAddress(snapshot) };
+ }
+ case PluginPayloadRole.Validators:
+ {
+ return new[] { Blockchain.GetConsensusAddress(NativeContract.NEO.GetNextBlockValidators(snapshot)) };
+ }
+ case PluginPayloadRole.StateValidator:
+ case PluginPayloadRole.Oracle:
+ {
+ return new[] { Blockchain.GetConsensusAddress(NativeContract.Designate.GetDesignatedByRole(snapshot, (Role)WitnessRole, snapshot.Height)) };
+ }
+ }
+
+ throw new ArgumentException();
+ }
+
+ void ISerializable.Serialize(BinaryWriter writer)
+ {
+ ((IVerifiable)this).SerializeUnsigned(writer);
+ writer.Write((byte)1); writer.Write(Witness);
+ }
+
+ void IVerifiable.SerializeUnsigned(BinaryWriter writer)
+ {
+ writer.WriteVarString(Plugin);
+ writer.Write(MessageType);
+ writer.WriteVarBytes(Data);
+ writer.Write((byte)WitnessRole);
+ }
+
+ public bool Verify(StoreView snapshot)
+ {
+ return this.VerifyWitnesses(snapshot, 0_02000000);
+ }
+ }
+}

src/neo/Network/P2P/Payloads/PluginPayloadRole.cs

@@ -0,0 +1,10 @@
+namespace Neo.Network.P2P.Payloads
+{
+ public enum PluginPayloadRole : byte
+ {
+ Committee = 0,
+ Validators = 2,
+ StateValidator = 4,
+ Oracle = 8
+ }
+}

src/neo/Network/P2P/RemoteNode.ProtocolHandler.cs

@@ -39,6 +39,12 @@ protected override UInt256 GetKeyForItem((UInt256, DateTime) item)
 
  private void OnMessage(Message msg)
  {
+ if (msg.Command == MessageCommand.Plugin)
+ {
+ var payload = (PluginPayload)msg.Payload;
+ if (!knownHashes.Add(payload.Hash)) return;
+ if (!payload.Verify(Blockchain.Singleton.GetSnapshot())) return;
+ }
  foreach (IP2PPlugin plugin in Plugin.P2PPlugins)
  if (!plugin.OnP2PMessage(msg))
  return;
@@ -107,6 +113,9 @@ private void OnMessage(Message msg)
  if (msg.Payload.Size <= Transaction.MaxTransactionSize)
  OnInventoryReceived((Transaction)msg.Payload);
  break;
+ case MessageCommand.Plugin:
+ OnPluginMessage(msg);
+ break;
  case MessageCommand.Verack:
  case MessageCommand.Version:
  throw new ProtocolViolationException();
@@ -119,6 +128,11 @@ private void OnMessage(Message msg)
  }
  }
 
+ private void OnPluginMessage(Message msg)
+ {
+ system.LocalNode.Tell(msg);
+ }
+
  private void OnAddrMessageReceived(AddrPayload payload)
  {
  ref bool sent = ref sentCommands[(byte)MessageCommand.GetAddr];