服务端

using System.Net.Sockets;
using System.Net;


int serverPort = 50001;
Socket server;
EndPoint client = new IPEndPoint(IPAddress.Any, 0);//用来保存发送方的ip和端口号

CreateSocket();

void CreateSocket()
{
    server = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
    IPAddress ip = IPAddress.Any;
    server.Bind(new IPEndPoint(ip, serverPort));//绑定端口号和IP
    Console.WriteLine("服务端已经开启，监听端口："+ serverPort);
    Thread t = new Thread(ReciveMsg);//开启接收消息线程
    t.Start();

}

/// <summary>
/// 接收发送给本机ip对应端口号的数据报
/// </summary>
void ReciveMsg()
{
    byte[] buffer = new byte[1024];
    while (true)
    {
        
        Console.WriteLine("等待接收数据 ...");
        int length = server.ReceiveFrom(buffer, ref client);//接收数据报
        try
        {
            int no = BitConverter.ToInt32(buffer, 0);
            long getd = BitConverter.ToInt64(buffer, 4);

            //string message = Encoding.UTF8.GetString(buffer, 0, length);
            Console.WriteLine(client.ToString() + " : " + no + "," + getd);

            server.SendTo(buffer, client);
        }
        catch
        {
            Console.WriteLine("error."+ client.ToString()+","+ buffer.Length.ToString());
        }
    }
}

注意下端口号，可以使用下面的命令查看是否被占用

netstat -alnp |grep 50001

如果没输出代表没有被使用，注意防火墙开启udp的端口

客户端

#define WLOG

using System.Net.Sockets;
using System.Net;
using System.Text;
using System.Diagnostics;

string serverIp = "192.168.3.76";
int serverPort = 50001;
int lost = 0;   //丢包率
long ping = 0;

Socket client;
EndPoint server;
int sendno = 0; //连续编号



int lostcount = 10;  //丢包百分比数组
int[] losts = new int[lostcount];

EndPoint recivePoint = new IPEndPoint(IPAddress.Any, 0);//用来保存发送方的ip和端口号
CreateClient();




void CreateClient()
{
    for (int i = 0; i < lostcount; i++)
        losts[i] = 1;

    client = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
    client.Bind(new IPEndPoint(IPAddress.Any, 0));

    server = new IPEndPoint(IPAddress.Parse(serverIp), serverPort);

    Thread t = new Thread(sendMsg);
    t.Start();

    Thread t2 = new Thread(ReciveMsg);
    t2.Start();
}


void Send()
{
    //发包格式#0编号，1时间
    long milliseconds = DateTimeOffset.Now.ToUnixTimeMilliseconds();
    List<byte> byteSource = new List<byte>();
    byteSource.AddRange(BitConverter.GetBytes(sendno));
   
    byte[] tick = BitConverter.GetBytes(milliseconds);
    byteSource.AddRange(tick);
    //byte[] sendata = milliseconds.tob Encoding.UTF8.GetBytes("unity hellp");
    byte[] data = byteSource.ToArray();

    client.SendTo(data, server);

    
    losts[sendno % lostcount] = 0;

    sendno++;

    Console.WriteLine("data:"+ milliseconds.ToString()+ ",lost:"+ lost+"%");
}
/// <summary>
/// 向特定ip的主机的端口发送数据报
/// </summary>
void sendMsg()
{

    while (true)
    {
        Send();
        Thread.Sleep(500);
        ComputLost();
        Thread.Sleep(500);
    }
}

void ComputLost()
{
    int all = 0;
    for (int i = 0; i < lostcount; i++)
    {
        if (losts[i] == 0)
            all++;
    }
    lost = (int)(all * 100.0 / lostcount);
}

/// <summary>
/// 接收发送给本机ip对应端口号的数据报
/// </summary>
void ReciveMsg()
{
    byte[] buffer = new byte[1024];
    while (true)
    {
        try
        {
            int length = client.Receive(buffer);//, ref recivePoint);//接收数据报

            int no = BitConverter.ToInt32(buffer, 0);
            long getd = BitConverter.ToInt64(buffer, 4);

           
            long milliseconds = DateTimeOffset.Now.ToUnixTimeMilliseconds();
            ping = milliseconds - getd;
            losts[no % lostcount] = (int)ping+1;
           
            Console.WriteLine(recivePoint.ToString() + " , no : " + no + " , getd : " + getd + " , ping : " + ping);
        }
        catch(Exception e) 
        {
            Console.WriteLine(e.ToString());
        }
    }
}

其中ping就是发包返回的时间。lost都是发10个包丢了几个。

在Centos部署

把代码拷贝到centos目录下

如果没安装dotnet，我们安装运行时就可以了

sudo rpm -Uvh https://packages.microsoft.com/config/centos/7/packages-microsoft-prod.rpm

sudo yum install dotnet-runtime-7.0

如果直接运行，可以输入

dotnet PingServer.dll

创建服务开机启动

vim /etc/systemd/system/pingserver.service

内容如下

[Unit]
Description=pingserver for centos7

[Service]
WorkingDirectory=/home/pingserver/Release
ExecStart=/usr/bin/dotnet /home/pingserver/Release/PingServer.dll
Restart=always
RestartSec=10  # Restart service after 10 seconds if dotnet service crashes
SyslogIdentifier=dotnet-pingserver
User=root
Environment=ASPNETCORE_ENVIRONMENT=Production
Environment=DOTNET_PRINT_TELEMETRY_MESSAGE=false

[Install]
WantedBy=multi-user.target

可以设置开机启动

systemctl enable pingserver.service

开启和状态

systemctl start pingserver.service
systemctl stop pingserver.service
systemctl status pingserver.service

注意配置文件如果在windows下编辑，记得换行符要改成LF（unix）格式的utf8才可以。