Initial commit: Ananta CBT 4229938 private server with all fixes

Ananta.SDK/Rpc/RpcPacketReader.cs

@@ -0,0 +1,34 @@
+using System.Buffers.Binary;
+
+namespace Ananta.SDK.Rpc;
+
+public static class RpcPacketReader
+{
+    public static RpcPacket Parse(ReadOnlySpan<byte> payload)
+    {
+        if (payload.Length < 5)
+            return new RpcPacket(RpcPacketKind.Unknown, 0, 0, payload.ToArray());
+
+        var tag = payload[0];
+        var methodId = BinaryPrimitives.ReadUInt32LittleEndian(payload[1..5]);
+
+        if (tag == 0x03)
+        {
+            return new RpcPacket(RpcPacketKind.Notify, methodId, 0, payload[5..].ToArray());
+        }
+
+        if (tag == 0x01 && payload.Length >= 9)
+        {
+            var invokeId = BinaryPrimitives.ReadInt32LittleEndian(payload[5..9]);
+            return new RpcPacket(RpcPacketKind.Invoke, methodId, invokeId, payload[9..].ToArray());
+        }
+
+        if (tag == 0x02 && payload.Length >= 13)
+        {
+            var invokeId = BinaryPrimitives.ReadInt32LittleEndian(payload[5..9]);
+            return new RpcPacket(RpcPacketKind.Return, methodId, invokeId, payload[13..].ToArray());
+        }
+
+        return new RpcPacket(RpcPacketKind.Unknown, methodId, 0, payload.ToArray());
+    }
+}