80 lines
2.5 KiB
C#
80 lines
2.5 KiB
C#
using System;
|
|
using System.Collections;
|
|
using System.Collections.Generic;
|
|
using UnityEngine;
|
|
using System.Net;
|
|
using System.Net.Sockets;
|
|
|
|
namespace ThinkingSDK.PC.Time
|
|
{
|
|
public class ThinkingSDKNTPCalibration : ThinkingSDKTimeCalibration
|
|
{
|
|
public ThinkingSDKNTPCalibration(string ntpServer) {
|
|
DateTime ntpTime = GetNetworkTime(ntpServer);
|
|
double totalMilliseconds = ConvertDateTimeInt(ntpTime);
|
|
|
|
this.mStartTime = (long)totalMilliseconds;
|
|
this.mSystemElapsedRealtime = Environment.TickCount;
|
|
}
|
|
|
|
private static double ConvertDateTimeInt(System.DateTime time)
|
|
{
|
|
DateTime startTime = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
|
|
return (double)(time - startTime).TotalMilliseconds;
|
|
}
|
|
|
|
private static DateTime GetNetworkTime(string ntpServer)
|
|
{
|
|
// NTP message size - 16 bytes of the digest (RFC 2030)
|
|
var ntpData = new byte[48];
|
|
|
|
//Setting the Leap Indicator, Version Number and Mode values
|
|
ntpData[0] = 0x1B; //LI = 0 (no warning), VN = 3 (IPv4 only), Mode = 3 (Client Mode)
|
|
|
|
var addresses = Dns.GetHostEntry(ntpServer).AddressList;
|
|
|
|
//The UDP port number assigned to NTP is 123
|
|
var ipEndPoint = new IPEndPoint(addresses[0], 123);
|
|
//NTP uses UDP
|
|
var socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
|
|
|
|
socket.Connect(ipEndPoint);
|
|
|
|
//Stops code hang if NTP is blocked
|
|
socket.ReceiveTimeout = 3000;
|
|
|
|
socket.Send(ntpData);
|
|
socket.Receive(ntpData);
|
|
socket.Close();
|
|
|
|
//Offset to get to the "Transmit Timestamp" field (time at which the reply
|
|
//departed the server for the client, in 64-bit timestamp format."
|
|
const byte serverReplyTime = 40;
|
|
|
|
//Get the seconds part
|
|
ulong intPart = BitConverter.ToUInt32(ntpData, serverReplyTime);
|
|
|
|
//Get the seconds fraction
|
|
ulong fractPart = BitConverter.ToUInt32(ntpData, serverReplyTime + 4);
|
|
|
|
//Convert From big-endian to little-endian
|
|
intPart = SwapEndianness(intPart);
|
|
fractPart = SwapEndianness(fractPart);
|
|
|
|
var milliseconds = (intPart * 1000) + ((fractPart * 1000) / 0x100000000L);
|
|
|
|
//**UTC** time
|
|
var networkDateTime = (new DateTime(1900, 1, 1, 0, 0, 0, DateTimeKind.Utc)).AddMilliseconds((long)milliseconds);
|
|
|
|
// return networkDateTime.ToLocalTime();
|
|
return networkDateTime;
|
|
}
|
|
|
|
static uint SwapEndianness(ulong x)
|
|
{
|
|
return (uint)(((x & 0x000000ff) << 24) + ((x & 0x0000ff00) << 8) + ((x & 0x00ff0000) >> 8) + ((x & 0xff000000) >> 24));
|
|
}
|
|
}
|
|
|
|
|
|
} |