Получить внешний ip, socket,recv( ), win

string GetExternalIP( )
{
    string ip;
    // Create socket object
    SOCKET sock = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
 
    if( sock == SOCKET_ERROR )  // bad socket?
    {
        return string( );
    }
 
    sockaddr_in sa;
    sa.sin_family = AF_INET;
    sa.sin_port = htons( 80 );  // HTTP service uses port 80
 
    // Time to get the hostname of www.whatismyip.com
    hostent *h = gethostbyname( WHATISMYIP );
 
    if( !h )
        return string( );
 
    memcpy( &sa.sin_addr.s_addr, h->h_addr_list[0], 4 );
 
    if( connect( sock, (sockaddr*)&sa, sizeof( sa ) ) == SOCKET_ERROR )
        return string( );
 
    // This is our packet that we are going to send to the HTTP server.
    char Packet[] =
        "GET /automation/n09230945.asp HTTP/1.1\r\n"    // GET request fetches a page
        "Host: " WHATISMYIP "\r\n"                      // we MUST use this param as of HTTP/1.1
        "Referrer: \r\n"                                // Heh... you should remove this.
        "\r\n";                                         // final \r\n
 
    int rtn = 0;
    int iOptVal = 3;
    int iOptLen = sizeof( int );
    setsockopt( sock, SOL_SOCKET, SO_SNDTIMEO, reinterpret_cast<char*>(&iOptVal), iOptLen );
    rtn = send( sock, Packet, sizeof( Packet ) - 1, 0 );
 
    if( rtn <= 0 )
        return string( );
 
    char Buffer[16384] = { 0 };
    setsockopt( sock, SOL_SOCKET, SO_RCVTIMEO, reinterpret_cast<char*>(&iOptVal), iOptLen );
    rtn = recv( sock, Buffer, sizeof( Buffer ), 0 );
    closesocket( sock );
    // ВОТ ТУТ RECV ВОЗВРАЩАЕТ 0 НА WIN10, но не на win7
    if( rtn <= 0 )
        return string( );
 
    // Did we get a valid reply back from the server?
    if( _strnicmp( Buffer, "HTTP/1.1 200 OK", 15 ) )
        return string( );
 
    char *p = strstr( Buffer, "Cache-control: private" );
 
    if( p == nullptr )
        return string( );
 
    if( strlen( p ) < 26 )
        return string( );
 
    if( p[26] < 0x30 || p[26]>0x39 )
        return string( );
 
    for( int i = 26; p[i] != 0; i++ )
    {
        ip += p[i];
    }
 
    return ip;
}