/// <summary>
/// A message was recived then forwared onto a remote time server.
/// </summary>
private void SendRequest(SntpMessageEventArgs args)
{
try
{
using (Socket _sendSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp))
{
Byte[] messageBuffer = new Byte[Constants.SNTP_MAX_MESSAGE_SIZE];
IPEndPoint remoteEndPoint = null;
try
{
IPHostEntry timeHost = Dns.GetHostEntry(_primaryServer);
remoteEndPoint = new IPEndPoint(timeHost.AddressList[0], Constants.SNTP_CLIENT_PORT);
_sendSocket.Connect(remoteEndPoint);
}
catch
{
Logger.WriteInfo(this, "Failed to contact primary server " + _primaryServer + " failed. Trying again using alternate server " + _alternateServer
+ " endpoint " + remoteEndPoint.ToString());
IPHostEntry timeHost = Dns.GetHostEntry(_alternateServer);
remoteEndPoint = new IPEndPoint(timeHost.AddressList[0], Constants.SNTP_CLIENT_PORT);
_sendSocket.Connect(remoteEndPoint);
}
if (remoteEndPoint != null)
{
_sendSocket.ReceiveTimeout = Constants.SNTP_RECEIVE_TIMEOUT;
_sendSocket.SendTimeout = Constants.SNTP_SEND_TIMEOUT;
// send message
_sendSocket.Connect(remoteEndPoint);
_sendSocket.Send(args.RequestMessage.ToArray());
Logger.WriteDebug(this, "PACKET successfully sent to client endpoint " +
remoteEndPoint.ToString());
Logger.WriteDebug(args.RequestMessage.ToString());
// receive message
_sendSocket.Receive(messageBuffer);
_sendSocket.Close();
args.ResponseMessage = new SntpMessage(messageBuffer);
Logger.WriteDebug(this, "PACKET successfully received from client endpoint " +
remoteEndPoint.ToString());
Logger.WriteDebug(args.ResponseMessage.ToString());
}
}
}
catch (SocketException ex)
{
Logger.WriteError(this, ex.Message + "Socket Error Code: " + ex.ErrorCode.ToString(), ex);
}
catch (Exception ex)
{
Logger.WriteError(this, "Error Message:" + ex.Message.ToString(), ex);
}
}
/// <summary>
/// Process request and send reply back to rempte client.
/// </summary>
private void ProcessRequest(Object state)
{
SntpMessageEventArgs args = (SntpMessageEventArgs)state;
if (args.RequestMessage != null)
{
switch (args.RequestMessage.Mode)
{
case Mode.Client:
if (_useLocalTimeSource == true)
{
args.ResponseMessage = args.RequestMessage;
args.ResponseMessage.Mode = Mode.Server;
args.ResponseMessage.ReceiveDateTime = DateTime.UtcNow;
args.ResponseMessage.TransmitDateTime = DateTime.UtcNow;
args.ResponseMessage.Stratum = Stratum.Secondary;
args.ResponseMessage.ReferenceIdentifier = ReferenceIdentifier.LOCL;
this.SendReply(args);
}
else
{
this.SendRequest(args);
this.SendReply(args);
}
break;
case Mode.Broadcast:
case Mode.Reserved:
case Mode.ReservedNTPControl:
case Mode.ReservedPrivate:
case Mode.Server:
case Mode.SymmetricActive:
case Mode.SymmetricPassive:
break;
default:
Logger.WriteInfo(this, "UNKNOWN message mode received and ignored");
break;
}
}
}
/// <summary>
/// A message is processsed and reply is sent back.
/// </summary>
private void SendReply(SntpMessageEventArgs args)
{
try
{
args.Channel.SendTo(args.ResponseMessage.ToArray(), args.Channel.RemoteEndpoint);
Logger.WriteDebug(this, "PACKET with channel id " +
args.Channel.ChannelId.ToString() +
" successfully sent to client endpoint " +
args.Channel.RemoteEndpoint.ToString());
Logger.WriteDebug(args.ResponseMessage.ToString());
OnSntpMessageSent(this, args);
}
catch (Exception ex)
{
Logger.WriteError(this, "Error Message:" + ex.Message.ToString(), ex);
}
}
/// <summary>
/// Remote client connects and makes a request.
/// </summary>
private void OnClientConnect(object sender, ClientConnectedEventArgs args)
{
SocketBuffer channelBuffer = args.ChannelBuffer;
if (channelBuffer != null &&
args.Channel.IsConnected &&
channelBuffer.BytesTransferred >= Constants.SNTP_MIN_MESSAGE_SIZE &&
channelBuffer.BytesTransferred <= Constants.SNTP_MAX_MESSAGE_SIZE)
{
Logger.WriteDebug(this, "PACKET request with channel id " +
args.Channel.ChannelId.ToString() +
" was received from " +
args.Channel.RemoteEndpoint.ToString() +
" and queued for processing...");
SntpMessageEventArgs messageArgs = new SntpMessageEventArgs(args.Channel, args.ChannelBuffer);
OnSntpMessageReceived(this, messageArgs);
ThreadPool.QueueUserWorkItem(new WaitCallback(ProcessRequest), messageArgs);
}
}
static void SntpService_OnSntpMessageSent(object sender, SntpMessageEventArgs args)
{
Debug.Print("Emulator: SNTP Message Sent " + args.RequestMessage.ToString());
}
/// <summary>
/// A message was recived then forwared onto a remote time server.
/// </summary>
private void SendRequest(SntpMessageEventArgs args)
{
try
{
using (Socket _sendSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp))
{
Byte[] messageBuffer = new Byte[Constants.SNTP_MAX_MESSAGE_SIZE];
IPEndPoint remoteEndPoint = null;
try
{
IPHostEntry timeHost = Dns.GetHostEntry(_primaryServer);
remoteEndPoint = new IPEndPoint(timeHost.AddressList[0], Constants.SNTP_CLIENT_PORT);
_sendSocket.Connect(remoteEndPoint);
}
catch
{
Logger.WriteInfo(this, "Failed to contact primary server " + _primaryServer + " failed. Trying again using alternate server " + _alternateServer
+ " endpoint " + remoteEndPoint.ToString());
IPHostEntry timeHost = Dns.GetHostEntry(_alternateServer);
remoteEndPoint = new IPEndPoint(timeHost.AddressList[0], Constants.SNTP_CLIENT_PORT);
_sendSocket.Connect(remoteEndPoint);
}
if (remoteEndPoint != null)
{
_sendSocket.ReceiveTimeout = Constants.SNTP_RECEIVE_TIMEOUT;
_sendSocket.SendTimeout = Constants.SNTP_SEND_TIMEOUT;
// send message
_sendSocket.Connect(remoteEndPoint);
_sendSocket.Send(args.RequestMessage.ToArray());
Logger.WriteDebug(this, "PACKET successfully sent to client endpoint " +
remoteEndPoint.ToString());
Logger.WriteDebug(args.RequestMessage.ToString());
// receive message
_sendSocket.Receive(messageBuffer);
_sendSocket.Close();
args.ResponseMessage = new SntpMessage(messageBuffer);
Logger.WriteDebug(this, "PACKET successfully received from client endpoint " +
remoteEndPoint.ToString());
Logger.WriteDebug(args.ResponseMessage.ToString());
}
}
}
catch (SocketException ex)
{
Logger.WriteError(this, ex.Message + "Socket Error Code: " + ex.ErrorCode.ToString(), ex);
}
catch (Exception ex)
{
Logger.WriteError(this, "Error Message:" + ex.Message.ToString(), ex);
}
}
/// <summary>
/// A message is processsed and reply is sent back.
/// </summary>
private void SendReply(SntpMessageEventArgs args)
{
try
{
args.Channel.SendTo(args.ResponseMessage.ToArray(), args.Channel.RemoteEndpoint);
Logger.WriteDebug(this, "PACKET with channel id " +
args.Channel.ChannelId.ToString() +
" successfully sent to client endpoint " +
args.Channel.RemoteEndpoint.ToString());
Logger.WriteDebug(args.ResponseMessage.ToString());
OnSntpMessageSent(this, args);
}
catch (Exception ex)
{
Logger.WriteError(this, "Error Message:" + ex.Message.ToString(), ex);
}
}
/// <summary>
/// Remote client connects and makes a request.
/// </summary>
private void OnClientConnect(object sender, ClientConnectedEventArgs args)
{
SocketBuffer channelBuffer = args.ChannelBuffer;
if (channelBuffer != null
&& args.Channel.IsConnected
&& channelBuffer.BytesTransferred >= Constants.SNTP_MIN_MESSAGE_SIZE
&& channelBuffer.BytesTransferred <= Constants.SNTP_MAX_MESSAGE_SIZE)
{
Logger.WriteDebug(this, "PACKET request with channel id " +
args.Channel.ChannelId.ToString() +
" was received from " +
args.Channel.RemoteEndpoint.ToString() +
" and queued for processing...");
SntpMessageEventArgs messageArgs = new SntpMessageEventArgs(args.Channel, args.ChannelBuffer);
OnSntpMessageReceived(this, messageArgs);
ThreadPool.QueueUserWorkItem(new WaitCallback(ProcessRequest), messageArgs);
}
}