Winsock 2 C Test - Server

// WinSock32Test.cpp : Defines the entry point for the console application.
//

#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <WinSock2.h>
#include <ws2tcpip.h>
#include <iphlpapi.h>
#include <stdio.h>
#include <stdlib.h>
#include <tchar.h>

#pragma comment(lib, "Ws2_32.lib")

#define DEFAULT_PORT "27015"
#define BUFSIZE 1024

int _tmain(int argc, _TCHAR* argv[])
{
    WSADATA wsaData;
    int iResult;
    TCHAR buf[BUFSIZE];
    sockaddr_in remaddr;
    socklen_t addrlen = sizeof(remaddr);
    int recvlen;

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

    struct addrinfo *result = NULL, *ptr = NULL, hints;

    ZeroMemory(&hints, sizeof(hints));
    hints.ai_family = AF_INET;
    hints.ai_socktype = SOCK_DGRAM;
    hints.ai_protocol = IPPROTO_UDP;
    hints.ai_flags = AI_PASSIVE;

    iResult = getaddrinfo(NULL, DEFAULT_PORT, &hints, &result);
    if (iResult != 0) {
        printf("getaddrinfo failed: %d\n", iResult);
        WSACleanup();
        return 1;
    }

    SOCKET ListenSocket = INVALID_SOCKET;
    ListenSocket = socket(result->ai_family, result->ai_socktype, result->ai_protocol);

    if (ListenSocket == INVALID_SOCKET)
    {
        printf("Error at socket(): %ld\n", WSAGetLastError());
        freeaddrinfo(result);
        WSACleanup();
        return 1;
    }

    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);
    while (strncmp(buf, "END", BUFSIZE) != 0)
    {
        recvlen = recvfrom(ListenSocket, buf, BUFSIZE, 0, (sockaddr *)&remaddr, &addrlen);
        printf("received %d bytes\n", recvlen);
        if (recvlen > 0){
            buf[recvlen] = 0;
            printf("received message: %s\n", buf);
        }

        TCHAR sendBuf[] = "testReturn";
        int sendlen = sendto(ListenSocket, sendBuf, strlen(sendBuf), 0, (sockaddr *)&remaddr, addrlen);
        if (sendlen < 0)
        {
            printf("return message failed\n");
        }
        else
        {
            printf("return message sent\n");
        }
    }

    system("PAUSE");
    closesocket(ListenSocket);
    WSACleanup();
    return 0;
}