主机(client)与ubuntu虚拟机(server)的通信(Version 1.0)

秒速五厘米 2021-12-13 20:59 277阅读 0赞

以下两个程序实现了ubuntu虚拟机 -> 主机VS2017的数据通信. 虽然实现了数据的通信, 但是有个问题值得我们注意: 当建立连接后, 我们在一段时间后关闭client程序(VS2017), 此时ubuntu端的send()函数会阻塞------这样一来, 每当我们在VS2017端关闭一次客户端程序, ubuntu端就会多一个浪费内存空间的服务端处理进程: 当VS2017端频繁开启关闭客户端程序, ubuntu端的压力会很大. 所以, 接下来如何应对客户端程序关闭变成了主要问题(应对方案将在Version 1.1中发布).

现在以下两个程序已经能够实现将ubuntu虚拟机端产生的数据送到主机VS 2017端.

//server.c 服务端
    #include <stdio.h>
    #include <stdlib.h>
    #include <errno.h>
    #include <unistd.h>
    #include <string.h>
    #include <sys/types.h>
    #include <netinet/in.h>
    #include <sys/socket.h>
    #include <sys/wait.h>
    #include <arpa/inet.h> 
    #include <time.h>
    #define SERVPORT 3333
    #define BACKLOG 10
    int random_number()//generating a random number
    {
        int a;
        srand((unsigned)time(NULL));
        a = rand();
        return a;
    }
    int main()
    {	
        int sockfd,client_fd;
        int value;
        int recvbytes;
        int sin_size;
        char buf[50];
        struct sockaddr_in my_addr;    
        struct sockaddr_in remote_addr; 
        sockfd = socket(AF_INET, SOCK_STREAM, 0);//建立socket --
        my_addr.sin_family=AF_INET;//AF_INET地址族
        my_addr.sin_port=htons(SERVPORT);//设定端口号(host -> networks)
        my_addr.sin_addr.s_addr = INADDR_ANY;//32位IPv4地址
        bzero(&(my_addr.sin_zero),8); //置前8个字节为0
        if (bind(sockfd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr)) == -1) 
         {
      	  perror("bind 出错！");		
    	  exit(1);	
         }
        if (listen(sockfd, BACKLOG) == -1) //监听socket连接，设置队列中最多拥有连接个数为10  --
         {	
    	  perror("listen 出错！");	
            exit(1);     
         }
        while(1)
         {
    	  sin_size = sizeof(struct sockaddr_in);//记录sockaddr_in结构体所占字节数
    	  if ((client_fd = accept(sockfd, (struct sockaddr *)&remote_addr, &sin_size)) == -1) //accept()缺省是阻塞函数，阻塞到有连接请求为止 --
              {	
    	      perror("accept error");		
    	      continue;		
    	  }
    	  printf("收到一个连接来自： %s\n", inet_ntoa(remote_addr.sin_addr));
    	  if (!fork()) 
              {
    		//test 1
    		//recv(client_fd, buf, 25, 0);
    		//printf("%s\n", buf); 	  
    	
    		//test 2
    		//send(client_fd, "12345", 5, 0);	
    			
    		//sending pieces of message to client
    		while(1)
    		{
    		    //generating a random number and sending it to the host
    
    		    value = random_number();
    
           	            sprintf(buf, "%d", value);//int to string
    
    		    //every one second client sends a random number converted to string to client
    			
    		    send(client_fd, buf, (int)strlen(buf), 0);
    		    
    		    sleep(1);
    		}
    		
                	close(client_fd);	
                	exit(0);		
              }
    	  close(client_fd);
         }
    }

//client 客户端 Visual Studio 2017 professional
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    using System.Net;
    using System.Net.Sockets;
    using System.Threading;
    
    namespace data_receiving
    {
        class Program
        {
            public static Socket ClientSocket;
            public static String IP = "192.168.239.132";//ubuntu虚拟机(server端)的IP地址
            public static void receive_message()//接收ubuntu虚拟机发来的数据
            {
                int port = 3333;//通信端口
    
                IPAddress ip = IPAddress.Parse(IP);  //将IP地址字符串转换成IPAddress实例
                ClientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);//使用指定的地址簇协议、套接字类型和通信协议
                IPEndPoint endPoint = new IPEndPoint(ip, port); // 用指定的ip和端口号初始化IPEndPoint实例
                ClientSocket.Connect(endPoint);  //与远程主机建立连接
    
                //ClientSocket.Send(Encoding.ASCII.GetBytes("12345")); //测试PC -> Ubuntu的连通性
    
                byte[] receive = new byte[100];
    
                //ClientSocket.Receive(receive); //测试Ubuntu -> PC的连通性
    
                //Console.WriteLine(Encoding.ASCII.GetString(receive));
    
                while(true)
                {
                    int length = ClientSocket.Receive(receive);
    
                    Thread.Sleep(1000);//程序休眠1s, 与server端保持同步
    
                    Console.WriteLine("接收消息为：" + Encoding.ASCII.GetString(receive));
                }
     
                ClientSocket.Close();  //关闭连接
    
            }
            static void Main(string[] args)//收到ubuntu虚拟机发来的数据, 并显示到终端
            {
                receive_message();
            }
        }
    }

在ubuntu端运行服务端程序.

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjA0ODQ2Mw_size_16_color_FFFFFF_t_70][]

在主机端运行客户端程序.

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回到服务端.

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjA0ODQ2Mw_size_16_color_FFFFFF_t_70 2][]

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