public static Result <NtpMessage> ParseFromBytes(byte[] bytes)
{
if (bytes.Length < MinMessageSizeInBytes || bytes.Length > MaxMessageSizeInBytes)
{
return(Result.Fail <NtpMessage>("Incorrect input data (should be more than 48 and less than 68)"));
}
var leapIndicator = (LeapIndicator)((bytes[0] & 0b11000000) >> 6);
var versionNumber = (bytes[0] & 0b00111000) >> 3;
var mode = bytes[0] & 0b00000111;
var stratum = bytes[1];
var pollInterver = bytes[2];
var precision = bytes[3];
var rootDelay = Converter.ToUInt32(bytes, 4);
var rootDispersion = Converter.ToUInt32(bytes, 8);
var referenceId = Converter.ToUInt32(bytes, 12);
var referenceTimestamp = TimeStamp.ReadFromByteArray(bytes, 16);
var originateTimestmap = TimeStamp.ReadFromByteArray(bytes, 24);
var receiveTimestamp = TimeStamp.ReadFromByteArray(bytes, 32);
var transmitTimestamp = TimeStamp.ReadFromByteArray(bytes, 40);
var id = bytes.Length > 48 ? Converter.ToUInt32(bytes, 48) : 0;
var digest = bytes.Length > 48 ? BitConverter.ToString(bytes, 52) : "";
var result = new NtpMessage
{
LeapIndicator = leapIndicator,
VersionNumber = versionNumber,
Mode = mode,
Stratum = stratum,
PollInterver = pollInterver,
Precision = precision,
RootDelay = rootDelay,
RootDispersion = rootDispersion,
ReferenceId = referenceId,
ReferenceTimestamp = referenceTimestamp,
OriginateTimestmap = originateTimestmap,
ReceiveTimestamp = receiveTimestamp,
TransmitTimestamp = transmitTimestamp,
Id = id,
Digest = digest
};
return(Result.Ok(result));
}
public static Result <NtpMessage> GenerateReplyFrom(NtpMessage ntpRequest, DateTime currentTime)
{
var receiveTimestamp = TimeStamp.FromDateTime(currentTime - StartTime);
var result = new NtpMessage
{
LeapIndicator = LeapIndicator.NoWarning,
VersionNumber = ntpRequest.VersionNumber,
Mode = RequestMode,
Stratum = 1,
PollInterver = ntpRequest.PollInterver,
Precision = 0xe9,
RootDelay = 0,
RootDispersion = 0,
ReferenceId = BitConverter.ToUInt32(Encoding.UTF8.GetBytes("LOCL"), 0),
ReceiveTimestamp = receiveTimestamp,
OriginateTimestmap = ntpRequest.TransmitTimestamp,
ReferenceTimestamp = receiveTimestamp,
TransmitTimestamp = receiveTimestamp,
Digest = ""
};
return(Result.Ok(result));
}
