C# 端口转发

谁践踏了优雅 2022-05-27 06:25 549阅读 0赞

业务需要跳转ip，又不想迁移程序，可以用此方法进行端口转发

![这里写图片描述][70]

static void Main(string[] args)
            {
                //默认 127.0.0.1：8080 转发到 127.0.0.1：80
                var dk = new DuanKou("0.0.0.0",8080,"0.0.0.0",80);
                dk.Run();
                Console.ReadKey();
            }
     /// <summary>
        /// user => tcp1 => tcp2
        /// </summary>
        public class DuanKou
        {
            int localProt { get; set; }
            string localIp { get; set; }
            int TargetPort { get; set; }
            string TargetIp { get; set; }
            public DuanKou(string localIp,int localProt, string TargetIp, int TargetPort)
            {
                this.localIp = localIp;
                this.localProt = localProt;
                this.TargetIp = TargetIp;
                this.TargetPort = TargetPort;
            }
    
            public DuanKou()
            {
                this.localIp = "0.0.0.0" ;
                this.localProt = 8080;
                this.TargetIp = "0.0.0.0";
                this.TargetPort = 80;
            }
    
            public void Run()
            {
                //服务器IP地址 
                IPAddress ip = IPAddress.Parse(localIp);
                Socket serverSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); ;
                serverSocket.Bind(new IPEndPoint(ip, localProt));
                serverSocket.Listen(10000);   
                Console.WriteLine("启动监听{0}成功", serverSocket.LocalEndPoint.ToString());
                Thread myThread = new Thread(Listen);
                myThread.Start(serverSocket);
            }
    
            //监听客户端连接
            private void Listen(object obj)
            {
                Socket serverSocket = (Socket)obj;
                IPAddress ip = IPAddress.Parse(TargetIp);
                while (true)
                {
                    Socket tcp1 = serverSocket.Accept();
                    Socket tcp2 = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    tcp2.Connect(new IPEndPoint(ip, TargetPort));
                    //目标主机返回数据
                    ThreadPool.QueueUserWorkItem(new WaitCallback(SwapMsg), new thSock
                    {
                        tcp1 = tcp2,
                        tcp2 = tcp1
                    });
                    //中间主机请求数据
                    ThreadPool.QueueUserWorkItem(new WaitCallback(SwapMsg), new thSock
                    {
                        tcp1 = tcp1,
                        tcp2 = tcp2
                    });
                }
            }
            ///两个 tcp 连接 交换数据，一发一收
            public void SwapMsg(object obj)
            {
                thSock mSocket = (thSock)obj;
                while (true)
                {
                    try
                    {
                        byte[] result = new byte[1024];
                        int num = mSocket.tcp2.Receive(result, result.Length,SocketFlags.None);
                        if (num == 0) //接受空包关闭连接
                        {
                            if (mSocket.tcp1.Connected)
                            {
                                mSocket.tcp1.Close();
                            }
                            if (mSocket.tcp2.Connected)
                            {
                                mSocket.tcp2.Close();
                            }
                            break;
                        }
                        mSocket.tcp1.Send(result, num, SocketFlags.None);
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                        if (mSocket.tcp1.Connected)
                        {
                            mSocket.tcp1.Close();
                        }
                        if (mSocket.tcp2.Connected)
                        {
                            mSocket.tcp2.Close();
                        }
                        break;
                    }
                }
            }
    
        }
    
        public class thSock
        {
            public Socket tcp1 { get; set; }
            public Socket tcp2 { get; set; }
        }

[70]: /images/20220527/4787687f7db84bbe90b62a143cb87a13.png