windows网络编程 使用流式套接字实现网络通信

【实验要求】
(1)使用基本的服务器编程模式，创建流式套接字，根据指定端口号绑定服务，建立监听队列，并接受来自客户端的连接请求，收发数据；使用基本的客户端编程模式，能够创建流式套接字，通过用户的指定的服务器地址向指定服务器发起连接请求，与服务器之间实现收发数据，然后关闭连接。
(2)通过改进服务器端，实现服务器循环为多个客户端提供服务；服务器端能够实现显示对应客户端的IP地址；客户端实现用户输入信息方式与服务器对话。
(3)采用Windows环境下多线程开发方法改进服务器端，对每个客户连接请求独立创建通信线程，实现并发服务器。

客户端：

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
// 连接到WinSock 2对应的lib文件：Ws2_32.lib, Mswsock.lib, Advapi32.lib
#pragma comment (lib, "Ws2_32.lib")
#pragma comment (lib, "Mswsock.lib")
#pragma comment (lib, "AdvApi32.lib")
// 定义默认的缓冲区长度和端口号
#define DEFAULT_BUFLEN 1024
#define DEFAULT_PORT "27015"

#pragma warning(disable:4996)

int __cdecl main(int argc, char** argv)
{
	WSADATA wsaData;
	SOCKET ConnectSocket = INVALID_SOCKET;
	struct addrinfo* result = NULL, * ptr = NULL, hints;
	char sendbuf[DEFAULT_BUFLEN];
	char recvbuf[DEFAULT_BUFLEN];
	int iResult;
	int recvbuflen = DEFAULT_BUFLEN;
	char servIP[20] = "127.0.0.1";		// 保存输入的服务器IP

	// 初始化套接字
	iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
	if (iResult != 0) {
		printf("WSAStartup failed with error: %d\n", iResult);
		return 1;
	}
	ZeroMemory(&hints, sizeof(hints));
	hints.ai_family = AF_UNSPEC;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;

	while (true)
	{
		printf("请输入服务器域名/IP地址：\n>>>");
		fflush(stdout);
		scanf("%s", servIP);				// 输入服务器IP
		// 解析服务器地址和端口号
		iResult = getaddrinfo(servIP, DEFAULT_PORT, &hints, &result);
		if (iResult != 0) {
			printf("getaddrinfo failed with error: %d\n", iResult);
			fflush(stdout);
			continue;
			//WSACleanup();
			//return 1;
		}
		for (ptr = result; ptr != NULL; ptr = ptr->ai_next) {
			// 创建套接字
			ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype,
				ptr->ai_protocol);
			if (ConnectSocket == INVALID_SOCKET) {
				printf("socket failed with error: %ld\n", WSAGetLastError());
				WSACleanup();
				return 1;
			}
			// 向服务器请求连接
			iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen);
			if (iResult == SOCKET_ERROR) {
				closesocket(ConnectSocket);
				ConnectSocket = INVALID_SOCKET;
				continue;
			}
			break;
		}
		break;
	}
	freeaddrinfo(result);
	if (ConnectSocket == INVALID_SOCKET) {
		printf("Unable to connect to server!\n");
		WSACleanup();
		return 1;
	}
	printf(">>>连接到服务器(%s)...\n>>>连接成功...[ok]\n", servIP);
	struct sockaddr_in sa;			// 客户端ip
	int len = sizeof(sa);
	if (!getsockname(ConnectSocket, (struct sockaddr*) & sa, &len))
	{
		printf("Client Ip：%s   ", inet_ntoa(sa.sin_addr));
		printf("Client Port：%d \n\n", ntohs(sa.sin_port));
	}
	printf("====================================================\n");
	char buff[40] = "";
	sprintf(buff, "title client:[%s: %d]", inet_ntoa(sa.sin_addr), ntohs(sa.sin_port));
	system(buff);			// 设置客户端标题
	// 发送数据
	bool flag = true;
	while (flag)
	{
		printf("send: ");
		fflush(stdout);
		scanf("%s", sendbuf);		// 键盘输入数据
		if (0 == strncmp(sendbuf, "end", 3))						// 输入end 结束发送
		{
			// 数据发送结束，调用shutdown()函数声明不再发送数据，此时客户端仍可以接收数据
			iResult = shutdown(ConnectSocket, SD_SEND);
			if (iResult == SOCKET_ERROR) {
				printf("shutdown failed with error: %d\n", WSAGetLastError());
				closesocket(ConnectSocket);
				WSACleanup();
				return 1;
			}
			flag = false;
		}
		else
		{
			iResult = send(ConnectSocket, sendbuf, (int)strlen(sendbuf), 0);
			if (iResult == SOCKET_ERROR) {
				printf("send failed with error: %d\n", WSAGetLastError());
				closesocket(ConnectSocket);
				WSACleanup();
				return 1;
			}
			printf("@%s: Bytes Sent: %ld\n-----------------------\n", servIP, iResult);
		}
		// 持续接收数据，直到服务器关闭连接
		iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
		if (iResult > 0)
			printf("Bytes received: %d\n\n", iResult);
		else if (iResult == 0)
			printf("Connection closed\n");
		else
			printf("recv failed with error: %d\n", WSAGetLastError());

	}
	// 关闭套接字
	closesocket(ConnectSocket);
	// 释放资源
	WSACleanup();
	return 0;
}

服务器：

#undef UNICODE
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#include <thread>

using std::thread;		// 声明线程库

#pragma warning(disable:4996)
// 连接到WinSock 2对应的lib文件：Ws2_32.lib
#pragma comment (lib, "Ws2_32.lib")
// 定义默认的缓冲区长度和端口号
#define DEFAULT_BUFLEN 1024
#define DEFAULT_PORT "27015"

void task_connect(SOCKET, struct sockaddr_in);		// 线程处理函数，处理已连接的套接字通讯


int __cdecl main(void)
{
	WSADATA wsaData;
	int iResult;
	SOCKET ListenSocket = INVALID_SOCKET;
	SOCKET ClientSocket = INVALID_SOCKET;
	struct addrinfo* result = NULL;
	struct addrinfo hints;

	// 初始化WinSock
	iResult = WSAStartup(MAKEWORD(2, 2), &wsaData);
	if (iResult != 0) {
		printf("WSAStartup failed with error: %d\n", iResult);
		return 1;
	}

	ZeroMemory(&hints, sizeof(hints));
	// 声明IPv4地址族，流式套接字，TCP协议
	hints.ai_family = AF_INET;
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_protocol = IPPROTO_TCP;
	hints.ai_flags = AI_PASSIVE;
	// 解析服务器地址和端口号
	iResult = getaddrinfo(NULL, DEFAULT_PORT, &hints, &result);
	if (iResult != 0) {
		printf("getaddrinfo failed with error: %d\n", iResult);
		WSACleanup();
		return 1;

	}
	// 为面向连接的服务器创建套接字
	ListenSocket = socket(result->ai_family, result->ai_socktype, result->ai_protocol);
	if (ListenSocket == INVALID_SOCKET) {
		printf("socket failed with error: %ld\n", WSAGetLastError());
		freeaddrinfo(result);
		WSACleanup();
		return 1;

	}
	// 为套接字绑定地址和端口号
	iResult = bind(ListenSocket, result->ai_addr, (int)result->ai_addrlen);
	if (iResult == SOCKET_ERROR) {
		printf("bind failed with error: %d\n", WSAGetLastError());
		freeaddrinfo(result);
		closesocket(ListenSocket);
		WSACleanup();
		return 1;

	}
	freeaddrinfo(result);
	// 监听连接请求
	iResult = listen(ListenSocket, SOMAXCONN);
	if (iResult == SOCKET_ERROR) {
		printf("listen failed with error: %d\n", WSAGetLastError());
		closesocket(ListenSocket);
		WSACleanup();
		return 1;

	}
	printf("服务器已启动，正在监听...\n");

	// 接受客户端的连接请求，返回连接套接字ClientSocket
	// 循环接收
	int id = 0;		// 表示第几个客户端连接
	while (true)
	{
		ClientSocket = accept(ListenSocket, NULL, NULL);
		if (ClientSocket == INVALID_SOCKET) {
			printf("accept failed with error: %d\n", WSAGetLastError());
			closesocket(ListenSocket);
			WSACleanup();
			return 1;
		}
		printf("\n>>>连接成功...[ok]\n");
		struct sockaddr_in sa;			// 客户端ip
		int len = sizeof(sa);
		if (!getpeername(ClientSocket, (struct sockaddr*) & sa, &len))
		{
			printf("Client Ip：%s   ", inet_ntoa(sa.sin_addr));//显示客户端IP
			printf("Client Port：%d \n\n", ntohs(sa.sin_port));//显示端口号
		}
		thread task(task_connect, ClientSocket, sa);
		task.detach();
	}

	// 在必须要监听套接字的情况下释放该套接字
	closesocket(ListenSocket);

	WSACleanup();
	return 0;
}


void task_connect(SOCKET ClientSocket, struct sockaddr_in ip)
{
	int iResult;	// 保存接收到数据的长度
	char recvbuf[DEFAULT_BUFLEN];
	int recvbuflen = DEFAULT_BUFLEN;

	// 持续接收数据，直到对方关闭连接
	do
	{
		memset(recvbuf, 0, recvbuflen);
		iResult = recv(ClientSocket, recvbuf, recvbuflen, 0);
		if (iResult > 0)
		{
			// 情况1：成功接收到数据		[ip:port]:(len)data
			printf("[%s:%d]:(%d)\t\b>> %s\n", inet_ntoa(ip.sin_addr), ntohs(ip.sin_port), iResult, recvbuf);					// 打印数据


			strcpy(recvbuf, "ok!");	// 回复ok
			// 将缓冲区的内容回送给客户端
			int iSendResult = send(ClientSocket, recvbuf, (int)strlen(recvbuf), 0);
			if (iSendResult == SOCKET_ERROR) {
				printf("send failed with error: %d\n", WSAGetLastError());
				closesocket(ClientSocket);
				WSACleanup();
			}
			printf("reply : (%d) ok! \n-----------------------\n", iSendResult);
		}
		else if (iResult == 0) {
			// 情况2：连接关闭
			printf("Client [%s]: Connection closing...\n", inet_ntoa(ip.sin_addr));

		}
		else {
			// 情况3：接收发生错误
			printf("Client [%s]: recv failed with error: %d\n", inet_ntoa(ip.sin_addr), WSAGetLastError());
			closesocket(ClientSocket);
			printf("Client [%s]: Connection closing...\n", inet_ntoa(ip.sin_addr));
			return;

		}
	} while (iResult > 0);
	// 关闭连接
	iResult = shutdown(ClientSocket, SD_SEND);
	if (iResult == SOCKET_ERROR) {
		printf("Client [%s]: shutdown failed with error: %d\n", inet_ntoa(ip.sin_addr), WSAGetLastError());
		closesocket(ClientSocket);
		printf("Client [%s]: Connection closing...\n", inet_ntoa(ip.sin_addr));
		return;

	}
	// 关闭套接字，释放资源
	closesocket(ClientSocket);
}

获得本机IP:win+r,输入ipconfig即可。