TCP Socket

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一个简单的TCP socket通讯的实例。

功能简单说明：
服务端主线程一直阻塞在accept，每连接上一个客户端，就创建一个新的线程去处理这个客户端的消息。
其中新线程中一直处于接收客户端的消息中，每接收一次都回复一个keep alive，当收到来自客户端stop消息时，就断开连接，并关闭当前线程。

一.服务端

  1. 创建套接字

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    WORD sockVersion = MAKEWORD(2, 2);
    WSADATA wsaData;
    if (WSAStartup(sockVersion, &wsaData) != 0) {
    	return 0;
    }
    //WSA(Windows Sockets Asynchronous，Windows异步套接字)的启动命令

  2. 绑定套接字到IP和端口

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    //创建并初始化socket
    SOCKET listen_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (listen_socket == INVALID_SOCKET) {
    	printf("socket init error code:%d", WSAGetLastError());
    	return 0;
    }
    //绑定结构
    struct sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(6666);
    sin.sin_addr.S_un.S_addr = INADDR_ANY;
    //绑定
    if (bind(listen_socket, (LPSOCKADDR)&sin, sizeof(sin)) != 0) {
    	printf("bind socket error code:%d", WSAGetLastError());
    	closesocket(listen_socket);//注意socket回收
    	return 0;
    }

  3. 监听端口

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    //int listen( int sockfd, int backlog);
    //sockfd：用于标识一个已捆绑未连接套接口的描述字。
    //backlog：等待连接队列的最大长度。
    if (listen(listen_socket, 5) != 0) {
    	printf("listen socket error code:%d", WSAGetLastError());
    	closesocket(listen_socket);
    	return 0;
    }

  4. 等待客户端连接，每连接一个可以创建一个对应的套接字和线程去处理对应的消息

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    //等待客户端连接 线程在这里会阻塞
    sClient = accept(listen_socket, (LPSOCKADDR)&remoteAddr, &slen);

    if (sClient == INVALID_SOCKET) {
    	printf("accept client error code:%d", WSAGetLastError());
    	continue;
    }
    else {
    	printf("connect success\n");
    	DWORD handleID; 
    	//当连接成功时，创建一个线程处理该客户端的消息，然后继续等待下一个客户端的连接
    	HANDLE handleSecond = CreateThread(NULL, 0, ClientChat, (LPVOID)sClient, 0, &handleID);
    }

  5. 处理完之后需要回收线程和回收socket

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    //回收线程
    CloseHandle(handle);
    //回收socket
    closesocket(listen_socket);
    //WSA套接字清理
    WSACleanup();

二.客户端

  1. 创建套接字，初始化等。（和服务端一致）

  2. 连接服务端

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    sockaddr_in sin;
    sin.sin_family = AF_INET;
    sin.sin_port = htons(6666);
    //sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    inet_pton(AF_INET, "192.168.0.190", (void*)&sin.sin_addr.S_un.S_addr);
    // 与指定地址端口连接
    if (connect(clientSocket, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR) {
    	printf("connect error code:%d", WSAGetLastError());
    	closesocket(clientSocket);
    	return  0;
    }
    else {
    	printf("connect success\n");
    }

  3. 和服务端之间收发消息

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    char rcv[256] = "";
    std::cout << "please input:";
    char sendData[128];
    while (std::cin >> sendData) {
    	// 向服务端发数据
    	int res = send(clientSocket, sendData, strlen(sendData), 0);
    	if (res == SOCKET_ERROR) {
    		printf("client send data error code:%d\n", WSAGetLastError());
    	}
    	else {
    		printf("client send data success\n");
    	}
    	//检测到发送的数据是stop时 断开连接
    	if (strcmp(sendData, "stop") == 0) {
    		break;
    	}
    	//接收数据之前先清空缓冲区，否则会有前一次传输的脏数据
    	memset(rcv, 0, sizeof(rcv));
    	int rec_res = recv(clientSocket, rcv, sizeof(rcv), 0);
    	if (rec_res > 0) {
    		printf("receive server bytes:%d, data:%s\n", res, rcv);
    		if (strcmp(rcv, "stop") == 0) {
    			break;
    		}
    	}
    	else if (rec_res == 0) {
    		printf("socket has closed\n");
    	}
    	else {
    		printf("recv failed: %d\n", WSAGetLastError());
    	}
    	std::cout << "please input:";
    }

  4. socket回收 同服务端

源代码：
服务端：

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//Server.cpp
#include <stdio.h>
#include <WinSock2.h>
#include <iostream>
#include <process.h>

#pragma comment( lib, "ws2_32.lib")

#define MAX_THREAD 10
struct ThreadMessage{
	SOCKET socket;
	DWORD id;
};

DWORD WINAPI ClientChat(LPVOID param);

int main() {
	WORD sockVersion = MAKEWORD(2, 2);
	WSADATA wsaData;

	if (WSAStartup(sockVersion, &wsaData) != 0) {
		return 0;
	}
	SOCKET listen_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (listen_socket == INVALID_SOCKET) {
		printf("socket init error code:%d", WSAGetLastError());
		return 0;
	}

	struct sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(6666);
	sin.sin_addr.S_un.S_addr = INADDR_ANY;

	if (bind(listen_socket, (LPSOCKADDR)&sin, sizeof(sin)) != 0) {
		printf("bind socket error code:%d", WSAGetLastError());
		closesocket(listen_socket);
		return 0;
	}

	if (listen(listen_socket, 5) != 0) {
		printf("listen socket error code:%d", WSAGetLastError());
		closesocket(listen_socket);
		return 0;
	}

	sockaddr_in remoteAddr;
	SOCKET sClient;
	int slen = sizeof(remoteAddr);
	char rcv[512];
	ThreadMessage thread[MAX_THREAD];
	int i = 0;
	while (true) {
		printf("server is ready, waiting for client ...");
		sClient = accept(listen_socket, (LPSOCKADDR)&remoteAddr, &slen);

		if (sClient == INVALID_SOCKET) {
			printf("accept client error code:%d", WSAGetLastError());
			continue;
		}
		else {
			printf("connect success\n");
			DWORD handleID; 
			thread[i].id = i;
			thread[i].socket = sClient;
			HANDLE handleSecond = CreateThread(NULL, 0, ClientChat, &thread[i], 0, &handleID);
			i++;
		}
		
	}

	closesocket(listen_socket);
	WSACleanup();

	return 0;
}

DWORD WINAPI ClientChat(LPVOID param) {
	ThreadMessage* msg = (ThreadMessage*)param;
	HANDLE handle = GetCurrentThread();
	if (msg->socket == INVALID_SOCKET) {
		printf("thread change error code:%d", WSAGetLastError());
		CloseHandle(handle);
		return 0;
	}
	char rcv[256] = "";
	while (1) {
		char sendData[256] = "keep alive"; 
		memset(rcv, 0, strlen(rcv));
		int res = recv(msg->socket, rcv, sizeof(rcv), 0);
		if (res > 0) {
			printf("tag:%d, receive client bytes:%d, data:%s\n", msg->id, res, rcv);
			if (strcmp(rcv, "stop") == 0) {
				memset(sendData, 0, strlen(sendData));
				sprintf_s(sendData, "stop");
				send(msg->socket, sendData, strlen(sendData), 0);
				break;
			}
			send(msg->socket, sendData, strlen(sendData), 0);
		}
		else if (res == 0) {
			printf("socket has closed\n");
		}
	}
	printf("close thread! \n");
	CloseHandle(handle);

}

客户端：

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//Client.cpp
#include <stdio.h>
#include <WinSock2.h>
#include<WS2tcpip.h>
#include <iostream>
#pragma comment(lib, "ws2_32.lib")

int main() {
	WORD wsaVer = MAKEWORD(2, 2);
	WSADATA wsaData;

	if (WSAStartup(wsaVer, &wsaData) != 0) {
		return 0;
	}

	SOCKET clientSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (clientSocket == INVALID_SOCKET) {
		printf("clientSocket error code:%d", WSAGetLastError());
		return 0;
	}

	sockaddr_in sin;
	sin.sin_family = AF_INET;
	sin.sin_port = htons(6666);
	//sin.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	inet_pton(AF_INET, "192.168.0.190", (void*)&sin.sin_addr.S_un.S_addr);

	if (connect(clientSocket, (LPSOCKADDR)&sin, sizeof(sin)) == SOCKET_ERROR) {
		printf("connect error code:%d", WSAGetLastError());
		closesocket(clientSocket);
		return  0;
	}
	else {
		printf("connect success\n");
	}

	char * sData = "Hello Server!";
	int res = send(clientSocket, sData, strlen(sData), 0);
	if (res == SOCKET_ERROR) {
		printf("client send data error code:%d\n", WSAGetLastError());
	}
	else {
		printf("client send data success\n");
	}
	char rcv[256] = "";
	std::cout << "please input:";
	char sendData[128];
	while (std::cin >> sendData) {
		int res = send(clientSocket, sendData, strlen(sendData), 0);
		if (res == SOCKET_ERROR) {
			printf("client send data error code:%d\n", WSAGetLastError());
		}
		else {
			printf("client send data success\n");
		}
		if (strcmp(sendData, "stop") == 0) {
			break;
		}
		memset(rcv, 0, sizeof(rcv));
		int rec_res = recv(clientSocket, rcv, sizeof(rcv), 0);
		if (rec_res > 0) {
			printf("receive server bytes:%d, data:%s\n", res, rcv);
			if (strcmp(rcv, "stop") == 0) {
				break;
			}
		}
		else if (rec_res == 0) {
			printf("socket has closed\n");
		}
		else {
			printf("recv failed: %d\n", WSAGetLastError());
		}
		std::cout << "please input:";
	}
	closesocket(clientSocket);
	std::cout << "socket close!\n";
	system("pause");
	return 0;
}

本文标题:TCP Socket

文章作者:Tokey

发布时间:2019年04月21日 - 23:04

最后更新:2021年06月29日 - 22:06

原始链接:http://TokeyRoad.github.io/2019/04/21/TCP Socket/

许可协议: 转载请保留原文链接及作者。

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