using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Net;
using System.Net.Sockets;
using System.Runtime.InteropServices;
namespace Spider
{
public class Daytime
{
//Internet Time Server class by Alastair Dallas 01/27/04
//Number of seconds
private const int THRESHOLD_SECONDS = 15;
// that Windows clock can deviate from NIST and still be okay
//Server IP addresses from
//http://www.boulder.nist.gov/timefreq/service/time-servers.html
private static string[] Servers = {
"129.6.15.28",
"129.6.15.29",
"132.163.4.101",
"132.163.4.102",
"132.163.4.103",
"128.138.140.44",
"192.43.244.18",
"131.107.1.10",
"66.243.43.21",
"216.200.93.8",
"208.184.49.9",
"207.126.98.204",
"205.188.185.33"
};
public static string LastHost = "";
public static DateTime LastSysTime;
public static DateTime GetTime()
{
//Returns UTC/GMT using an NIST server if possible,
// degrading to simply returning the system clock
//If we are successful in getting NIST time, then
// LastHost indicates which server was used and
// LastSysTime contains the system time of the call
// If LastSysTime is not within 15 seconds of NIST time,
// the system clock may need to be reset
// If LastHost is "", time is equal to system clock
string host = null;
DateTime result = default(DateTime);
LastHost = "";
foreach (string host_loopVariable in Servers)
{
host = host_loopVariable;
result = GetNISTTime(host);
if (result > DateTime.MinValue)
{
LastHost = host;
break; // TODO: might not be correct. Was : Exit For
}
}
if (string.IsNullOrEmpty(LastHost))
{
//No server in list was successful so use system time
result = DateTime.UtcNow;
}
return result;
}
public static int SecondsDifference(DateTime dt1, DateTime dt2)
{
TimeSpan span = dt1.Subtract(dt2);
return span.Seconds + (span.Minutes * 60) + (span.Hours * 360);
}
public static bool WindowsClockIncorrect()
{
DateTime nist = GetTime();
if ((Math.Abs(SecondsDifference(nist, LastSysTime)) > THRESHOLD_SECONDS))
{
return true;
}
return false;
}
private static DateTime GetNISTTime(string host)
{
//Returns DateTime.MinValue if host unreachable or does not produce time
DateTime result = default(DateTime);
string timeStr = null;
try
{
StreamReader reader = new StreamReader(new TcpClient(host, 13).GetStream());
LastSysTime = DateTime.UtcNow;
timeStr = reader.ReadToEnd();
reader.Close();
}
catch (SocketException ex)
{
//Couldn't connect to server, transmission error
Debug.WriteLine("Socket Exception [" + host + "]");
return DateTime.MinValue;
}
catch (Exception ex)
{
//Some other error, such as Stream under/overflow
return DateTime.MinValue;
}
//Parse timeStr
if ((timeStr.Substring(38, 9) != "UTC(NIST)"))
{
//This signature should be there
return DateTime.MinValue;
}
if ((timeStr.Substring(30, 1) != "0"))
{
//Server reports non-optimum status, time off by as much as 5 seconds
return DateTime.MinValue;
//Try a different server
}
int jd = int.Parse(timeStr.Substring(1, 5));
int yr = int.Parse(timeStr.Substring(7, 2));
int mo = int.Parse(timeStr.Substring(10, 2));
int dy = int.Parse(timeStr.Substring(13, 2));
int hr = int.Parse(timeStr.Substring(16, 2));
int mm = int.Parse(timeStr.Substring(19, 2));
int sc = int.Parse(timeStr.Substring(22, 2));
if ((jd < 15020))
{
//Date is before 1900
return DateTime.MinValue;
}
if ((jd > 51544))
yr += 2000;
else
yr += 1900;
return new DateTime(yr, mo, dy, hr, mm, sc);
}
[StructLayout(LayoutKind.Sequential)]
public struct SYSTEMTIME
{
public Int16 wYear;
public Int16 wMonth;
public Int16 wDayOfWeek;
public Int16 wDay;
public Int16 wHour;
public Int16 wMinute;
public Int16 wSecond;
public Int16 wMilliseconds;
}
[DllImport("kernel32.dll", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
private static extern Int32 GetSystemTime(ref SYSTEMTIME stru);
[DllImport("kernel32.dll", CharSet = CharSet.Ansi, SetLastError = true, ExactSpelling = true)]
private static extern Int32 SetSystemTime(ref SYSTEMTIME stru);
public static void SetWindowsClock(DateTime dt)
{
//Sets system time. Note: Use UTC time; Windows will apply time zone
SYSTEMTIME timeStru = default(SYSTEMTIME);
Int32 result = default(Int32);
timeStru.wYear = (Int16)dt.Year;
timeStru.wMonth = (Int16)dt.Month;
timeStru.wDay = (Int16)dt.Day;
timeStru.wDayOfWeek = (Int16)dt.DayOfWeek;
timeStru.wHour = (Int16)dt.Hour;
timeStru.wMinute = (Int16)dt.Minute;
timeStru.wSecond = (Int16)dt.Second;
timeStru.wMilliseconds = (Int16)dt.Millisecond;
result = SetSystemTime(ref timeStru);
}
}
}