C ++ Winsock IP 204.204.204.204

Question

我正在尝试学习Winsock，当我尝试运行此代码时：

#define _WINSOCK_DEPRECATED_NO_WARNINGS

#include <iostream> 
#include <WS2tcpip.h> 
#include <thread>
#include <chrono>
#pragma comment(lib, "ws2_32.lib") 

using namespace std;

void main() { 
    // Initialize Winsock
    WSAData data; 
    WORD ver = MAKEWORD(2, 2); 
    int wsOk = WSAStartup(ver, &data);

    if (wsOk != 0) { cerr << "Can't start winsock! Tactical Retreat!" << endl;
    return; 
    } 
    // Create socket 
    SOCKET listening = socket(AF_INET, SOCK_STREAM, 0); 
    if (listening == INVALID_SOCKET) { 
        cerr << "Couldn't create socket!" << endl;
        return; 
    } 


    // Bind the ip address and port to a socket 
    sockaddr_in hint; hint.sin_family = AF_INET; 
    hint.sin_port = htons(3800); 
    hint.sin_addr.S_un.S_addr = INADDR_ANY; // or inet_pton
    bind(listening, (sockaddr*)&hint, sizeof(hint));
    //Tell winsock the socket is for listening 
    listen(listening, SOMAXCONN); // Wait for a connection 


    sockaddr_in client; 
    int clientSize = sizeof(client); 

    SOCKET clientSocket = accept(listening, (sockaddr*) &client, &clientSize); 

    char host[NI_MAXHOST]; // Client's remote name 
    char service[NI_MAXHOST]; // Service (i.e port) 
    ZeroMemory(host, NI_MAXHOST); ZeroMemory(service, NI_MAXHOST); 

    if (getnameinfo((sockaddr*)&client, sizeof(client), host, NI_MAXHOST, service, NI_MAXSERV, 0) == 0) { 
        cout << " connected on port " << service << endl; } 
    else { inet_ntop(AF_INET, &client.sin_addr, host, NI_MAXHOST); 
    cout << host << " connected on port" << htons(client.sin_port) << endl; } // Close listening socket closesocket(listening); // While loop: accept and echo message back to client 
    char buf[4096];

    while (true) {
        ZeroMemory(buf, 4096); // Wait for client to send data 
        int bytesRecieved = recv(clientSocket, buf, 4096, 0);
        if (bytesRecieved == SOCKET_ERROR) {
            cerr << "Error in recv(). Quitting" << endl;
            break;
        }

        if (bytesRecieved == 0) {
            cout << "client disconnected " << endl;
            break;
        } // Echo message back to client 

        send(clientSocket, buf, bytesRecieved * 1, 0);
    }// Close 
        closesocket(clientSocket); // Cleanup Winsock
        WSACleanup();

        std::this_thread::sleep_for(std::chrono::milliseconds(10000));

    }

这是从我复制并试图自己运行的youtube教程中获取的代码。每次我运行它，它说客户端已连接IP地址：204.204.204.204。我已经解决了问题，但我仍然无法让它工作......似乎问题来自：

sockaddr_in client; 
 int clientSize = sizeof(client); 
 SOCKET clientSocket = accept(listening, (sockaddr*) &client, &clientSize);

我不确定为什么它已经接受了连接。我没有看到任何错误。

编辑：

我做了一个接受检查但它失败了：

if (clientSocket == INVALID_SOCKET) {


        cout << "error on socket" << endl;
        std::this_thread::sleep_for(std::chrono::milliseconds(10000));
        return;
    }

似乎&clientSize检索NULL。我不知道该怎么做。