阻塞模式客户端与服务器相互问候 TCP/IP通信 63页

红太狼 2022-05-23 05:18 94阅读 0赞

1.  代码来源于 》》》》》》》》》》》》》》》》》》》》》 Windows Sockets网络开发VC++ 这本书

1.  在stdafx.h 中添加 \#pragma comment(lib,"ws2\_32.lib")

服务器实现

// ServerCSgreeting.cpp : 客户端与服务器相互问候。
    //
    
    #include "stdafx.h"
    #include "winsock2.h"
    #include "funtiondec.h"   //所需函数声明
    #include "string.h"
    
    #define MAX_NUM_BUF 20  //需要读入数据的大小
    #define SERVER_DLL_REEOR 1 //调用Windows sockets DLL失败
    #define SERVER_API_ERROR 2 //调用socket DLL失败
    #define SERVERPORT 5555   // 服务器TCP端口
    //#define INVALID_SOCKET (SOCKET)(~0)
    //#define SOCKET_ERROR    (-1)
    
    
    char bufRecv[MAX_NUM_BUF]; //读缓冲区
    char  bufSend[MAX_NUM_BUF]; //写缓冲区
    SOCKET sServer;  //服务器监听套接字
    SOCKET sClient;  //接受客户端套接字
    bool bConning;   //与客户端的连接状态变量
    
    
    /*
    	初始化成员变量
    */
    void InitMember(void)
    {
    	//初始化读和写缓冲区
    	memset(bufRecv, 0, MAX_NUM_BUF);
    	memset(bufSend, 0, MAX_NUM_BUF);
    
    	//初始化
    	sServer = INVALID_SOCKET;
    	sClient = INVALID_SOCKET;
    
    	//没有连接状态
    	bConning = FALSE;
    }
    
    /*
    	Windows Sockets 动态库的初始化
    */
    int InitWinSoDll(void)
    {
    	WSADATA wsaData;
    	WORD wVersionRequested = MAKEWORD(1, 1);
    	int retVal = WSAStartup(wVersionRequested, &wsaData);
    
    	if (0 != retVal)
    	{
    		printf("Can not find a usable Windows Sockets dll!");
    		return SERVER_DLL_REEOR;
    	}
    
    	//确保WinSock DLL 支持1.1
    	if (LOBYTE(wsaData.wVersion) != 1 || HIBYTE(wsaData.wVersion) != 1)
    	{
    		printf("Can not find a usable Windows Sockets dll!");
    		WSACleanup();
    		return SERVER_DLL_REEOR;
    	}
    
    	return 0;
    }
    
    /*
    	创建套接字
    */
    int CreateSocket(void)
    {
    	sServer = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    	if (INVALID_SOCKET == sServer)
    	{
    		return HandleSocketError("Failed socket()!");
    	}
    
    	return 0;
    }
    
    /*
    	错误处理
    */
    int HandleSocketError(char *str)
    {
    	printf("%s", str);
    	WSACleanup();
    
    	return SERVER_API_ERROR;
    }
    
    /*
    	绑定套接字
    */
    int BindSoc(void)
    {
    	//服务器套接字地址
    	SOCKADDR_IN addrServ;
    	addrServ.sin_family = AF_INET;
    	addrServ.sin_port = htons(SERVERPORT);
    	addrServ.sin_addr.s_addr = INADDR_ANY;
    	
    
    	//绑定套接字
    	int retVal = bind(sServer, (LPSOCKADDR)&addrServ, sizeof(SOCKADDR_IN));
    	if (SOCKET_ERROR == retVal)
    	{
    		closesocket(sServer);  //关闭套接字
    		return HandleSocketError("Failed bind()!");  //错误处理
    	}
    
    	return 0;
    }
    
    /*
    	监听
    */
    int ListenSoc(void)
    {
    	//开始监听
    	int retVal = listen(sServer, 1);
    	if (SOCKET_ERROR == retVal)
    	{
    		closesocket(sServer);
    		return HandleSocketError("Failed listen()!");
    	}
    
    	//等待客户端的连接
    	printf("Server succeeded!\n");
    	printf("Waiting for new clients...\n");
    	return 0;
    }
    
    /*
    	接受请求
    */
    int AcceptSoc(void)
    {
    	//接受客户端请求
    	sockaddr_in addrClient;
    	int addrClientlen = sizeof(addrClient);
    
    	sClient = accept(sServer, (sockaddr FAR*)&addrClient, &addrClientlen);
    	if (INVALID_SOCKET == sClient)
    	{
    		closesocket(sServer);
    		return HandleSocketError("Failed accept()!");
    	}else
    	{
    		bConning = TRUE;  //客户端请求成功
    	}
    
    	//显示客户端的IP和端口
    	char *pClientIP = inet_ntoa(addrClient.sin_addr);
    	u_short clientPort = ntohs(addrClient.sin_port);
    	printf("Accept a client.\n");
    	printf("IP:%s\n", pClientIP);
    	printf("Port:%d\n", clientPort);
    
    	return 0;
    }
    
    /*
    	接收数据
    */
    BOOL RecvLine(SOCKET s, char* buf)
    {
    	BOOL retVal = TRUE;  //返回值
    	BOOL bLineEnd = FALSE;  //行结束
    	int nReadLen = 0;  //读入字节数
    	int nDataLen = 0;  //数据长度
    	while (!bLineEnd && bConning)  //与客户端连接 没有换行
    	{
    		nReadLen = recv(s, buf + nDataLen, 1, 0); // 每次接收一个字节
    
    		//错误处理
    		if (SOCKET_ERROR == nReadLen)
    		{
    			int nErrCode = WSAGetLastError();  //错误代码
    			if (WSAENOTCONN == nErrCode)
    			{
    				printf("The socket is not conected!\n");
    			}
    			else if (WSAESHUTDOWN == nErrCode)
    			{
    				printf("The socket has been shut down!\n");
    			}
    			else if (WSAETIMEDOUT == nErrCode)
    			{
    				printf("The connection has been dropped!\n");
    			}
    			else if (WSAECONNRESET == nErrCode)
    			{
    				printf("The virtual circuit was reset by the remote side!\n");
    			}
    			else{}
    
    			retVal = FALSE;// 读取数据失败
    			break;
    		}
    
    		if (0 == nReadLen) //客户端关闭
    		{
    			retVal = FALSE;  //读取数据失败
    			break;
    		}
    
    		//读入数据
    		if ('\n' == *(buf + nDataLen))
    		{
    			bLineEnd = TRUE;  //接收数据结束
    		}
    		else
    		{
    			nDataLen += nReadLen;  //增加数据掺毒
    		}
    	}
    
    	return retVal;
    }
    
    /*
    	发送一行数据
    */
    BOOL SendLine(SOCKET s, char* str)
    {
    	int retVal;  //返回值
    	retVal = send(s, str, strlen(str), 0);  //一次发送
    
    	//错误处理
    	if (SOCKET_ERROR == retVal)
    	{
    		int nErrCode = WSAGetLastError();
    		if (WSAENOTCONN == nErrCode)
    		{
    			printf("The socket is not conected!");
    		}
    		else if (WSAESHUTDOWN == nErrCode)
    		{
    			printf("The socket has been shut down!");
    		}
    		else if (WSAETIMEDOUT == nErrCode)
    		{
    			printf("The connection has been dropped!");
    		}
    		else{}
    
    		return FALSE;  //发送失败
    	}
    	return TRUE;  //发送成功
    }
    
    /*
    	退出
    */
    int ExitClient(int nExit)
    {
    	closesocket(sServer);  //关闭监听套接字
    	closesocket(sClient);  //关闭连接客户端套接字
    	WSACleanup();  //卸载Windows Sockets DLL清理内存
    	return nExit; //退出
    }
    
    int _tmain(int argc, _TCHAR* argv[])
    {
    	char bufSend[MAX_NUM_BUF] = { NULL };
    	char bufRecv[MAX_NUM_BUF] = { NULL };
    
    	strcpy_s(bufSend, "Hello,Client!\n");
    
    	InitMember(); // 初始化成员
    	InitWinSoDll();  //初始化Windows Sockets DLL
    
    	CreateSocket();  //创建套接字
    	BindSoc();      //绑定套接字
    	ListenSoc();  //监听
    	AcceptSoc();  //接受客户端请求
    
    
    	if (!RecvLine(sClient, bufRecv)) //接收数据
    	{
    		return HandleSocketError("RecvLine Error!\n");
    	}
    	printf("RecvLine=%s\n", bufRecv);
    
    	printf("RecvLine succeeded!\n");
    	if (!SendLine(sClient, bufSend))//发送一行数据
    	{
    		return ExitClient(SERVER_API_ERROR);
    	}
    
    	ExitClient(0);
    
    	return 0;
    }

客户端实现

// ClientCSgreeting.cpp : 定义控制台应用程序的入口点。
    //
    
    #include "stdafx.h"
    #include "winsock2.h"
    #include "funtiondec.h"
    #include "string.h"
    
    #define MAX_NUM_BUF 25  //需要读写入数据的大小
    #define CLIENT_SOCKET_DLL_ERROR 1 //调用Windows sockets DLL失败
    #define CLIENT_API_ERROR 2   //创建套接字失败
    #define SERVERPORT 5555   // 服务器TCP端口
    
    char bufRecv[MAX_NUM_BUF]; //读缓冲区
    char bufSend[MAX_NUM_BUF]; //写缓冲区
    SOCKET sHost; //套接字
    bool bConning;   //与服务器的连接状态变量
    
    /*
    初始化成员变量
    */
    void InitMember(void)
    {
    	//初始化读和写缓冲区
    	memset(bufRecv, 0, MAX_NUM_BUF);
    	memset(bufSend, 0, MAX_NUM_BUF);
    
    	//初始化
    	sHost = INVALID_SOCKET;
    
    	//没有连接状态
    	bConning = FALSE;
    }
    
    /*
    Windows Sockets 动态库的初始化
    */
    int InitWinSoDll(void)
    {
    	WSADATA wsaData;
    	WORD wVersionRequested = MAKEWORD(1, 1);
    	int err = WSAStartup(wVersionRequested, (LPWSADATA)&wsaData);
    
    	if (0 != err)
    	{
    		printf("Can not find a usable Windows Sockets dll!");
    		return CLIENT_SOCKET_DLL_ERROR;
    	}
    
    
    	return 0;
    }
    
    /*
    创建套接字
    */
    int CreateSocket(void)
    {
    	//创建Windows socket
    	sHost = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    	if (INVALID_SOCKET == sHost)
    	{
    		ShowErrorMsg();  //显示错误信息
    		WSACleanup(); //释放资源
    		return CLIENT_API_ERROR;  //退出
    	}
    
    	return 0;
    }
    
    /*
    	显示错误信息
    */
    void ShowErrorMsg(void)
    {
    	int nErrCode = WSAGetLastError(); //获取错误代码
    	HLOCAL hlocal = NULL;
    
    	//获取错误的文本字符串
    	BOOL fok = FormatMessage(
    		FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER,
    		NULL, nErrCode, MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US),
    		(PTSTR)&hlocal, 0, NULL
    		);
    
    	//显示错误信息
    	if (hlocal != NULL)
    	{
    		MessageBox(NULL, (LPCWSTR)LocalLock(hlocal), _T("CLIENT ERROR"), MB_OK);
    		LocalFree(hlocal);
    	}
    }
    
    /*
    	客户端连接服务器
    */
    int ConnectSoc(void)
    {
    	//获取主机的信息
    	int retVal;
    	LPHOSTENT hostEntry;
    	char hostname[MAX_NUM_BUF];
    	gethostname(hostname, MAX_NUM_BUF);  //获取主机名称
    	hostEntry = gethostbyname(hostname);  //获取主机信息
    	
    	if (!hostEntry)
    	{
    		ShowErrorMsg();   //显示错误信息
    		return ExitClient(CLIENT_API_ERROR); //退出
    	}
    
    	//设置sockaddr_in
    	SOCKADDR_IN addrServ;
    	addrServ.sin_family = AF_INET;
    	addrServ.sin_addr = *((LPIN_ADDR)*hostEntry->h_addr_list);
    	addrServ.sin_port = htons(SERVERPORT);
    
    	char *pClientIP = inet_ntoa(addrServ.sin_addr);
    	printf("IP:%s\n", pClientIP);
    
    	//连接服务器
    	retVal = connect(sHost, (LPSOCKADDR)&addrServ, sizeof(SOCKADDR_IN));
    	if (SOCKET_ERROR == retVal)
    	{
    		ShowErrorMsg();   //显示错误信息
    		return ExitClient(CLIENT_API_ERROR);  //退出
    	}
    	else
    	{
    		bConning = TRUE;  //连接服务器成功
    		printf("Connect succeedend!\n");
    	}
    	return 0;
    }
    
    /*
    	发送数据
    */
    int SendData(char *str)
    {
    	
    	int retVal = send(sHost, str, strlen(str), 0);
    
    	if (SOCKET_ERROR == retVal)
    	{
    		ShowErrorMsg();  //显示错误信息
    		return ExitClient(CLIENT_API_ERROR); //退出
    	}
    	return 0;
    }
    
    /*
    	读取一行数据
    */
    BOOL RecvLine(SOCKET s, char* buf)
    {
    	BOOL retVal = TRUE;  //返回值
    	BOOL bLineEnd = FALSE;  //行结束
    	int nReadLen = 0;  //读入字节数
    	int nDataLen = 0;  //数据长度
    	while (!bLineEnd && bConning)
    	{
    		nReadLen = recv(s, buf + nDataLen, 1, 0); //每次接收一个字节
    
    		//错误处理
    		if (SOCKET_ERROR == nReadLen)
    		{
    			retVal = FALSE;  //读数据失败
    			break;  // 跳出循环
    		}
    
    		if (0 == nReadLen)  //客户端关闭
    		{
    			retVal = FALSE;  //读数据失败
    			break; 
    		}
    
    		//读入数据
    		if ('\n' == *(buf + nDataLen))  //换行符
    		{
    			bLineEnd = TRUE;  //接收数据结束
    		}
    		else
    		{
    			nDataLen += nReadLen;  //增加数据长度
    		}
    	}
    
    	return retVal;
    }
    
    /*
    	退出
    */
    int ExitClient(int nExit)
    {
    	closesocket(sHost);  //关闭连接服务器套接字
    	WSACleanup();  //卸载Windows Sockets DLL清理内存
    	return nExit; //退出
    }
    
    int _tmain(int argc, _TCHAR* argv[])
    {
    	char recvbuf[MAX_NUM_BUF] = { NULL };
    	char bufSend[MAX_NUM_BUF] = { NULL };
    
    	strcpy_s(bufSend, "Hello,Server!\n");
    
    	InitMember();  // 初始化成员
    	InitWinSoDll();   //初始化Windows Sockets DLL
    
    	CreateSocket();  //创建套接字
    	ConnectSoc();   //客户端连接套接字
    
    	if (SendData(bufSend) > 0)  //向服务器发送数据
    	{
    		printf("ClientSend Error\n");
    		ExitClient(1);
    	}
    	else
    	{
    		printf("ClientSend succeeded\n");
    		
    	}
    
    
    	if (RecvLine(sHost, recvbuf))  //读取一行数据
    	{
    		printf("ClientRecvLine=%s\n", recvbuf);
    		printf("RecvLine succeeded!\n");
    	}
    	
    	
    	
    
    	ExitClient(1);
    
    	return 0;
    }

效果图

![70][]

[70]: /images/20220523/d02ed261b6af4604939aa8b4eb943d64.png