From 359a3bb655e7cd82e3d68a7f2d0ee1b4cda68d2b Mon Sep 17 00:00:00 2001
From: Shargon <shargon@gmail.com>
Date: Sat, 18 Apr 2020 21:42:09 +0200
Subject: [PATCH] Only accept one mempool message per remote node

---
 src/neo/Network/P2P/RemoteNode.ProtocolHandler.cs | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/neo/Network/P2P/RemoteNode.ProtocolHandler.cs b/src/neo/Network/P2P/RemoteNode.ProtocolHandler.cs
index 91b3921326..4df1b56b80 100644
--- a/src/neo/Network/P2P/RemoteNode.ProtocolHandler.cs
+++ b/src/neo/Network/P2P/RemoteNode.ProtocolHandler.cs
@@ -30,6 +30,7 @@ protected override UInt256 GetKeyForItem((UInt256, DateTime) item)
         private readonly HashSetCache<UInt256> knownHashes = new HashSetCache<UInt256>(Blockchain.Singleton.MemPool.Capacity * 2 / 5);
         private readonly HashSetCache<UInt256> sentHashes = new HashSetCache<UInt256>(Blockchain.Singleton.MemPool.Capacity * 2 / 5);
         private bool verack = false;
+        private bool memPoolWasSent = false;
         private BloomFilter bloom_filter;
 
         private static readonly TimeSpan TimerInterval = TimeSpan.FromSeconds(30);
@@ -314,6 +315,14 @@ private void OnInvMessageReceived(InvPayload payload)
 
         private void OnMemPoolMessageReceived()
         {
+            if (memPoolWasSent)
+            {
+                Disconnect(true);
+                return;
+            }
+
+            memPoolWasSent = true;
+
             foreach (InvPayload payload in InvPayload.CreateGroup(InventoryType.TX, Blockchain.Singleton.MemPool.GetVerifiedTransactions().Select(p => p.Hash).ToArray()))
                 EnqueueMessage(Message.Create(MessageCommand.Inv, payload));
         }