Socket网络通信基础

缺乏、安全感 2022-10-27 02:41 252阅读 0赞

## 写在前面的话 ##

编译环境：VS2019 + win10

// pch.h
    #define WIN32_LEAN_AND_MEAN
    #include <Windows.h>
    #include <WinSock2.h>
    
    #pragma comment(lib, "Ws2_32.lib")
    
    #include <stdio.h>
    #include <iostream>
    
    
    using namespace std;

// server.cpp
    #include "pch.h"
    
    #pragma warning(disable:4996)
    
    int main(int argc, char** argv)
    { 
    #ifdef _WIN32
    	WSADATA wsadata = {  0 };
    	int iResult = WSAStartup(MAKEWORD(2, 2), &wsadata);
    	if (iResult)
    	{ 
    		cout << "init failed.." << WSAGetLastError() << endl;
    		return -1;
    	}
    #endif // _WIN32
    	SOCKET sock = INVALID_SOCKET;
    	sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    	if (sock == INVALID_SOCKET)
    	{ 
    		cout << "socket failed..." << WSAGetLastError() << endl;
    		return -1;
    	}
    	sockaddr_in sockAddrIn = {  0 };
    	sockAddrIn.sin_family = AF_INET;
    	sockAddrIn.sin_port = htons(4567);
    	sockAddrIn.sin_addr.S_un.S_addr = INADDR_ANY;
    	iResult = bind(sock, (sockaddr *)&sockAddrIn, sizeof(sockaddr_in));
    	// inet_addr("127.0.0.1")
    	if (iResult == SOCKET_ERROR)
    	{ 
    		cout << "bind error..." << WSAGetLastError() << endl;
    		closesocket(sock);
    		return -1;
    	}
    	iResult = listen(sock, 5);
    	if (iResult == SOCKET_ERROR)
    	{ 
    		cout << "listen error..." << WSAGetLastError() << endl;
    		closesocket(sock);
    		return -1;
    	}
    	sockaddr_in clientSockAddr = {  0 };
    	int iAddrLen = sizeof(sockaddr_in);
    	SOCKET clientSocket = INVALID_SOCKET;
    	char msgbuff[0x1000] = {  0 };
    	strcat_s(msgbuff, "hello, my name is server!");
    	int sendMsgLen = strlen(msgbuff) + 1;
    	int iSendByteNum = 0;
    	for (;;)
    	{ 
    		memset(&clientSockAddr, 0, sizeof(sockaddr_in));
    		clientSocket = INVALID_SOCKET;
    		clientSocket = accept(sock, (sockaddr*)&clientSockAddr, &iAddrLen);
    		if (clientSocket == INVALID_SOCKET)
    		{ 
    			cout << "accept failed..." << WSAGetLastError() << endl;
    			break;
    		}
    		cout << "accept successful... client ip:" << inet_ntoa(clientSockAddr.sin_addr) << endl;
    		iSendByteNum = send(clientSocket, msgbuff, sendMsgLen, MSG_OOB);
    		if (iSendByteNum == SOCKET_ERROR)
    		{ 
    			cout << "send failed..." << WSAGetLastError() << endl;
    			break;
    		}
    		cout << "the length of message is: " << iSendByteNum << endl;
    
    	}
    	
    	closesocket(sock);
    #ifdef _WIN32
    	WSACleanup();
    #endif
    	return 0;
    }

// client.cpp
    #include "pch.h"
    
    #pragma warning(disable:4996)
    
    int main(int argc, char** argv)
    { 
    	WSADATA wsadata = {  0 };
    	int iResult = 0;
    	iResult = WSAStartup(MAKEWORD(2, 2), &wsadata); // If successful, the WSAStartup function returns zero.
    	if (iResult)
    	{ 
    		cout << "init failed..." << WSAGetLastError() << endl;
    		return -1;
    	}
    	SOCKET _socket = INVALID_SOCKET;
    	_socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    	if (_socket == INVALID_SOCKET)
    	{ 
    		cout << "socket failed..." << WSAGetLastError() << endl;
    		WSACleanup();
    		return -1;
    	}
    	sockaddr_in sockAddr = {  0 };
    	sockAddr.sin_family = AF_INET;
    	sockAddr.sin_port = htons(4567);
    	sockAddr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    	iResult = connect(_socket, (sockaddr*)&sockAddr, sizeof(sockaddr));
    	if (iResult == SOCKET_ERROR)
    	{ 
    		cout << "connect failed..." << WSAGetLastError() << endl;
    		closesocket(_socket);
    		WSACleanup();
    		return -1;
    	}
    	char msgbuff[0x1000] = {  0 };
    	iResult = recv(_socket, msgbuff, 0x1000, MSG_PEEK);
    	if (iResult == SOCKET_ERROR)
    	{ 
    		cout << "recv failed..." << WSAGetLastError() << endl;
    	}
    	else
    	{ 
    		cout << "msg: " << msgbuff << endl;
    	}
    	closesocket(_socket);
    	WSACleanup();
    	getchar();
    	return 0;
    }