/// <summary>
/// Send a packet to a target IP address.
/// </summary>
/// <param name="sender">Default object parameter for event receiving methods. Unused here.</param>
/// <param name="args">PacketTransmissionEventArgs object containing the byte array to be send and the destination IP address.</param>
public void SendPacket(object sender, PacketTransmissionEventArgs args)
{
ControlledPacket ctrlPacket = new ControlledPacket();
ctrlPacket.Recipient = args.Destination;
ctrlPacket.Data = args.PacketContent;
_messageSendingControlList.Add(ctrlPacket);
}
/// <summary>
/// Attempt to send the controlled packet. Return true if successful.
/// </summary>
/// <param name="ctrlPacket">Packet to be sent.</param>
protected bool SendControlledPacket(ControlledPacket ctrlPacket)
{
try
{
_client.Send(ctrlPacket.Data, ctrlPacket.Data.Length, ctrlPacket.Recipient); // Send the packet.
}
catch (SocketException ex)
{
#if DEBUG
throw;
#else
System.Diagnostics.Debug.WriteLine("### An error happened when trying to send ControlledPacket:");
System.Diagnostics.Debug.WriteLine("### " + ex.Message);
System.Diagnostics.Debug.WriteLine("### " + ex.ToString());
return(false);
#endif
}
return(true);
}
/// <summary>
/// This is a threaded method that keeps looping while _online is true.
/// It will receive UDP messages on the UdpClient's port number and forward them to the OnPacketReceived event.
/// </summary>
public void ReceivePacket() // Threaded looping method.
{
while (_online)
{
try
{
IPEndPoint remoteSender = new IPEndPoint(IPAddress.Any, 0);
byte[] receivedBytes = _client.Receive(ref remoteSender);
if (receivedBytes != null && receivedBytes.Length != 0)
{
if (receivedBytes.Length == ByteHelper.HashByteLength + 2 && receivedBytes[0] == 0xCE && receivedBytes[receivedBytes.Length - 1] == 0xCE)
{
if (_messageSendingControlList.Count != 0)
{
// The received message is a ACK message.
string hash = OpenAck(receivedBytes);
ControlledPacket packet = _messageSendingControlList.Find(x => x.Hash == hash);
if (packet != null)
{
_messageSendingControlList.Remove(packet);
}
}
}
else if (receivedBytes.Length == 1 && receivedBytes[0] == 0xEC)
{
// Fire an OnEtherConnectionReply event.
OnEtherConnectionReply(null);
}
else
{
// Send back an ACK packet.
string hash = ByteHelper.GetHashString(receivedBytes);
byte[] ackBytes = CreateAck(hash);
_client.Send(ackBytes, ackBytes.Length, remoteSender);
// Check if the message is a duplicate.
if (!_messageReceivingControlList.Any(x => x == hash))
{
// Add the message's hash to a list so we don't react on the same message twice.
_messageReceivingControlList.Add(hash);
if (_messageReceivingControlList.Count > 5) // Only keep the latest 5 messages.
{
_messageReceivingControlList.RemoveAt(0);
}
// Fire an OnPacketReceived event.
PacketReceivedEventArgs args = new PacketReceivedEventArgs();
args.Sender = remoteSender;
args.Data = receivedBytes;
OnPacketReceived(args);
}
}
}
}
catch (SocketException ex)
{
if (ex.SocketErrorCode != SocketError.TimedOut)
{
System.Diagnostics.Debug.WriteLine("### " + _threadPacketListener.Name + " has crashed:");
System.Diagnostics.Debug.WriteLine("### " + ex.Message);
System.Diagnostics.Debug.WriteLine("### " + ex.ToString());
break;
}
else
{
continue;
}
}
}
}
