serwer UDP

#include <winsock.h>

#include <iostream>

using namespace std;

void UDPServer(short nPort);

int main()
{
    WORD wVersionRequested = MAKEWORD(2,2);

    WSADATA wsadata;

    int nRet;

    short nPort;

    cout << "Serwer UDP" << endl;

    cout << "Podaj nr portu, na ktorym mam nasluchiwac: ";

    cin >> nPort;

    nRet = WSAStartup(wVersionRequested, &wsadata);

    if(wsadata.wVersion != wVersionRequested)
    {
        cout << "WSADATA error: " << WSAGetLastError() << endl;

        return -1;
    }

    UDPServer(nPort);

    WSACleanup();

    cin.get();

    return 0;
}

void UDPServer(short nPort)
{
    SOCKET serversocket;

    serversocket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);

    if(serversocket == INVALID_SOCKET)
    {
        cout << "SOCKET error: " << WSAGetLastError() << endl;

        return;
    }

    SOCKADDR_IN serveraddr;

    serveraddr.sin_family = AF_INET;

    serveraddr.sin_addr.s_addr = INADDR_ANY;

    serveraddr.sin_port = htons(nPort);

    int nRet;

    nRet = bind(serversocket, (LPSOCKADDR)&serveraddr, sizeof(struct sockaddr));

    if(nRet == SOCKET_ERROR)
    {
        cout << "bind() error: " << WSAGetLastError() << endl;

        closesocket(serversocket);

        return;
    }

    char Buffer[256];

    nRet = gethostname(Buffer, sizeof(Buffer));

    if(nRet == SOCKET_ERROR)
    {
        cout << "gethostname() error: " << WSAGetLastError() << endl;

        closesocket(serversocket);

        return;
    }

    cout << "Server o nazwie " << Buffer << " nasluchuje na porcie: " << nPort << endl;

    SOCKADDR_IN clientaddr;

    int nLength = sizeof(SOCKADDR);

    memset(Buffer, 0, sizeof(Buffer));

    nRet = recvfrom(serversocket, Buffer, sizeof(Buffer), 0, (LPSOCKADDR)&clientaddr, &nLength);

    if(nRet == SOCKET_ERROR)
    {
        cout << "recvfrom() error: " << WSAGetLastError << endl;

        closesocket(serversocket);

        return;
    }

    cout << "Dane otrzymane od klienta: " << Buffer << endl;

    cout << "Wpisz komunikat zwrotny: ";

    char Message[256];

    cin >> Buffer;

    nRet = sendto(serversocket, Message, strlen(Message), 0, (LPSOCKADDR)&clientaddr, nLength);

    if(nRet == SOCKET_ERROR)
    {
        cout << "sendto() error: " << WSAGetLastError() << endl;

        closesocket(serversocket);

        return;
    }

    closesocket(serversocket);

    cin.get();

    return;
}