From 14ccff36e913db0c9f18f0c0403f6b3d074115fd Mon Sep 17 00:00:00 2001
From: xeon <xeon@xeondev.com>
Date: Tue, 30 Jan 2024 19:37:13 +0300
Subject: [PATCH] Fix networking bug in Gateserver

---
 .../Session/NetworkSession.cs                 | 44 ++++++++++++-------
 1 file changed, 27 insertions(+), 17 deletions(-)

diff --git a/RPG.Services.Gateserver/Session/NetworkSession.cs b/RPG.Services.Gateserver/Session/NetworkSession.cs
index 7e263eb..2e0fe89 100644
--- a/RPG.Services.Gateserver/Session/NetworkSession.cs
+++ b/RPG.Services.Gateserver/Session/NetworkSession.cs
@@ -37,25 +37,35 @@ internal class NetworkSession : RPGSession
 
             recvBufferIdx += readAmount;
 
-            do
-            {
-                switch (NetPacket.TryDeserialize(recvBufferMem[..recvBufferIdx], out NetPacket? packet, out int bytesRead))
-                {
-                    case NetPacket.DeserializationResult.Success:
-                        HandleSessionPacketAsync(packet!);
-                        Buffer.BlockCopy(_recvBuffer, bytesRead, _recvBuffer, 0, recvBufferIdx -= bytesRead);
-                        break;
-                    case NetPacket.DeserializationResult.BufferExceeded:
-                        recvBufferIdx = -1;
-                        break;
-                    case NetPacket.DeserializationResult.Corrupted:
-                        throw new InvalidDataException("The network stream was corrupted");
-                }
-            }
-            while (recvBufferIdx >= NetPacket.Overhead);
+            int consumed = ConsumeData(recvBufferMem, recvBufferIdx);
+            if (consumed > 0)
+                Buffer.BlockCopy(_recvBuffer, consumed, _recvBuffer, 0, recvBufferIdx -= consumed);
         }
     }
 
+    private int ConsumeData(ReadOnlyMemory<byte> recvBufferMem, int recvBufferIdx)
+    {
+        int consumedBytes = 0;
+
+        do
+        {
+            switch (NetPacket.TryDeserialize(recvBufferMem[consumedBytes..recvBufferIdx], out NetPacket? packet, out int bytesRead))
+            {
+                case NetPacket.DeserializationResult.Success:
+                    HandlePacket(packet!);
+                    consumedBytes += bytesRead;
+                    break;
+                case NetPacket.DeserializationResult.BufferExceeded:
+                    return consumedBytes;
+                case NetPacket.DeserializationResult.Corrupted:
+                    throw new InvalidDataException("The network stream was corrupted");
+            }
+        }
+        while (recvBufferIdx - consumedBytes >= NetPacket.Overhead);
+
+        return consumedBytes;
+    }
+
     public void ServiceBound(RPGServiceType serviceType)
     {
         _boundServices.Add(serviceType);
@@ -74,7 +84,7 @@ internal class NetworkSession : RPGSession
         await Socket!.SendAsync(buffer);
     }
 
-    private void HandleSessionPacketAsync(NetPacket packet)
+    private void HandlePacket(NetPacket packet)
     {
         switch ((CmdType)packet.CmdType)
         {