尽管所有数据包都到达，但 C# UDP 数据包丢失 (WireShark) [英] C# UDP packetloss though all packets arrive (WireShark)

问题描述

正如标题所说，我在 C# 中遇到了 UDP 问题.我正在尝试为 DayZ 游戏的 rcon 协议构建一个库.

As the title says I have a problem with UDP in C#. I'm trying to build a library for the rcon protocol of the game DayZ.

我的问题是我没有收到我应该收到的每个数据包.发送命令后，服务器回复一个拆分答案.数据包头包含总数据包计数和当前数据包的索引.现在，如果我应该得到 17 个数据包，我的应用程序中只会得到 8-15 个数据包.

My problem is that I dont receive every packet I should receive. After sending a command the server replies with an split answer. The packet header contains the total packet count and the index of the current packet. Now if I should get 17 packets I only get 8-15 packets in my application.

在使用 WireShark 进行测试后，我现在知道所有包裹都到达了我的计算机上.他们只是没有得到我的应用程序或类似的东西的认可.

After testing with WireShark I know now that all packages arrive on my computer. They just dont get recognized by my application or something like that.

我的实际问题是:是否可以防止丢失我的网卡和我的应用程序之间的包?或者为什么会这样?

My Actual Question is: Is it possible to prevent losing the packages between my network card and my application? or Why does that happen?

这是我当前的代码.它很脏，因为我在没有按预期工作后把它撕开了:

Here is my current code. Its pretty dirty because I ripped it apart after not working as expected:

    private Socket _udpClient;
    private Thread _receiverThread;
    private Thread _workerThread;
    private Queue<byte[]> _packetQueue;
    private PacketBuffer[] MessageBuffer;
    private byte SenderSequence = 0;
    private IPEndPoint connection;

    public RCon(IPAddress ip, int port)
    {
        connection = new IPEndPoint(ip, port);
        _udpClient = new Socket(connection.Address.AddressFamily, SocketType.Dgram, ProtocolType.Udp);
        _udpClient.Connect(connection);
        MessageBuffer = new PacketBuffer[256];
        _packetQueue = new Queue<byte[]>();

        _receiverThread = new Thread(new ThreadStart(ReceiveCallback));
        _receiverThread.IsBackground = true;
        _receiverThread.Priority = ThreadPriority.AboveNormal;
        _receiverThread.Start();
        _workerThread = new Thread(new ThreadStart(WorkerCallback));
        _workerThread.IsBackground = true;
        _workerThread.Start();
    }

    public void Login(string password)
    {
        LoginPacket packet = new LoginPacket(password);

        _udpClient.Send(packet.Bytes);
    }

    public void SendCommand(string command)
    {
        CommandPacket packet = new CommandPacket(SenderSequence, command);
        SenderSequence++;

        _udpClient.Send(packet.Bytes);
    }

    private void ReceiveCallback()
    {

        while (true)
        {
                byte[] buffer = new byte[1036];
                if (_udpClient.Receive(buffer) > 0)
                    _packetQueue.Enqueue(buffer);
        }
    }

    private void WorkerCallback()
    {
        while (true)
        {
            if (_packetQueue.Count > 0)
            {
                byte[] buffer = _packetQueue.Dequeue();

                if (buffer != null)
                {
                    try
                    {
                        Packet receivedPacket = Packet.ParseIncoming(buffer);

                        OnPacketReceived(new PacketReceivedEventArgs(receivedPacket));

                        switch (receivedPacket.Type)
                        {
                            case PacketType.Message:
                                OnMessageReceived(new MessageReceivedEventArgs(receivedPacket.Content));
                                MessageCallbackPacket packet = new MessageCallbackPacket(receivedPacket.SequenceNumber);
                                _udpClient.Send(packet.Bytes);
                                break;
                            case PacketType.CommandCallback:
                                if (MessageBuffer[receivedPacket.SequenceNumber] == null)
                                    MessageBuffer[receivedPacket.SequenceNumber] = new PacketBuffer(receivedPacket);
                                else
                                    MessageBuffer[receivedPacket.SequenceNumber].AddPacket(receivedPacket);

                                if (MessageBuffer[receivedPacket.SequenceNumber].IsComplete)
                                    OnCommandCallback(new CommandCallbackEventArgs(MessageBuffer[receivedPacket.SequenceNumber].GetContent()));
                                break;
                        }
                    }
                    catch (ArgumentException) { }
                    catch (OverflowException) { }
                    catch (FormatException) { }
                }
            }
        }
    }

推荐答案

这通常是因为你没有足够快地使用你的数据报，所以内核套接字缓冲区已满，网络堆栈开始丢弃新到达的数据包.几点:

This is usually because you are not consuming your datagrams fast enough, so in-kernel socket buffer gets full and the network stack starts dropping newly arriving packets. Some points:

• 增加套接字上的接收缓冲区，
• 不要在每次迭代时都获取锁 - 尽可能多地读取，然后将数据放入队列中，
• 考虑非阻塞方法而不是线程.

这篇关于尽管所有数据包都到达，但 C# UDP 数据包丢失 (WireShark)的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！