native windows winsock UDP cpp server and python client and

winsock2_UPD_server.cpp

#undef UNICODE

#define WIN32_LEAN_AND_MEAN

#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#include <stdlib.h>
#include <stdio.h>
#include <string>
#include <iostream>
#include <sstream> 
// Need to link with Ws2_32.lib
#pragma comment (lib, "Ws2_32.lib")
// #pragma comment (lib, "Mswsock.lib")

#define DEFAULT_BUFLEN 1024
#define DEFAULT_PORT "27014"

int __cdecl main(void) 
{
    WSADATA wsaData;
    int iResult;

    SOCKET ListenSocket = INVALID_SOCKET;
    SOCKET ClientSocket = INVALID_SOCKET;

    struct addrinfo *result = NULL;
    struct addrinfo hints;

    int iSendResult;
    char recvbuf[DEFAULT_BUFLEN];
    int recvbuflen = DEFAULT_BUFLEN;
    
    // Initialize Winsock
    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_INET;
    hints.ai_socktype = SOCK_DGRAM;
    hints.ai_protocol = IPPROTO_UDP;
    // hints.ai_flags = AI_PASSIVE;

    // Resolve the server address and port
    iResult = getaddrinfo(NULL, DEFAULT_PORT, &hints, &result);
    if ( iResult != 0 ) {
        printf("getaddrinfo failed with error: %d\n", iResult);
        WSACleanup();
        return 1;
    }

    // Create a SOCKET for connecting to server
    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;
    }
    int count = 0;
    std::stringstream buffer;
    ZeroMemory(recvbuf, sizeof(recvbuf));
    while (true)
    {
        buffer.str("");
        buffer << "hello world " << count << '\n';
        std::cout << buffer.str();
        count++;
        memcpy(recvbuf, buffer.str().c_str(), buffer.str().length()); 
        int i = sendto(ListenSocket, recvbuf, 1024, 0, result->ai_addr, result->ai_addrlen);
        if (i == -1)
            std::cout << "Error sending the packet\n";
        Sleep(100);
    }
    WSACleanup();
    return 0;
}

winsock_client.py

import socket
import sys

PORT = 27014              # The same port as used by the server
s = None
s = socket.socket(2, 2, 0)
s.bind(("127.0.0.1", PORT))
print('opened socket')
# s.settimeout(3.0)
while True:
    try:
        data = s.recv(1024)
        print('Received', str(data.decode("utf-8", errors='ignore')).split('\0')[0])
    except KeyboardInterrupt:
        sys.exit(1)
s.close()