public void Start()
{
NetworkClient.BeginReceive(NetworkMessageReceived, null);
if (LocalNode != null)
{
Console.WriteLine("Network: Listening on " + NetworkClient.Client.LocalEndPoint);
}
RetryTimer.Change(10000, 10000);
}
private void Accept(IAsyncResult res)
{
var clientSocket = Server.EndAccept(res);
clientSocket.ReceiveBufferSize = ClientBufferSize;
var client = new NetworkClient(this, clientSocket, ClientBufferSize);
OnConnect?.Invoke(client);
client.BeginReceive();
BeginAccept();
}
public BinaryClient(NetworkClient client)
{
_client = client;
client.Connected += Client_Connected;
client.Disconnected += Client_Disconnected;
client.DataReceived += Client_DataReceived;
if (_client.IsConnected)
{
_client.BeginReceive();
}
}
private void NetworkMessageReceived(IAsyncResult result)
{
IPEndPoint endPoint = default(IPEndPoint);
var payload = NetworkClient.EndReceive(result, ref endPoint);
NetworkClient.BeginReceive(NetworkMessageReceived, null);
var stream = new BinaryReader(new MemoryStream(payload), Encoding.UTF8);
AsymmetricKeyParameter key;
RemoteNode node = null;
if (endPoint.Address.Equals(IPAddress.Loopback))
{
key = CryptoProvider.PublicKey;
}
else
{
node = GetNode(endPoint);
if (node == null)
{
return;
}
key = node.PublicKey;
}
try
{
var id = stream.ReadString();
var flags = (MessageFlags)stream.ReadByte();
var transaction = stream.ReadUInt32();
var timestamp = new DateTime(stream.ReadInt64(), DateTimeKind.Utc);
if (node != null)
{
// TODO: Evaluate this margin of error, and this whole system in general that prevents resubmission
if (Math.Abs((timestamp - node.PreviousMessageTimestamp).TotalSeconds) > 10)
{
return;
}
node.PreviousMessageTimestamp = timestamp;
}
if (PacketFactories.ContainsKey(id))
{
var packet = PacketFactories[id]();
packet.Transaction = transaction;
packet.Read(stream);
int signatureLength = (int)(stream.BaseStream.Length - stream.BaseStream.Position);
int messageLength = (int)stream.BaseStream.Position;
stream.BaseStream.Seek(0, SeekOrigin.Begin);
byte[] message = new byte[messageLength];
byte[] signature = new byte[signatureLength];
stream.BaseStream.Read(message, 0, message.Length);
stream.BaseStream.Read(signature, 0, signature.Length);
// Verify signature
if (!CryptoProvider.VerifySignature(message, signature, key))
{
Console.WriteLine("Warning: Received internode network packet with bad signature from {0}", endPoint);
}
else
{
if (id == typeof(ConfirmationPacket).Name)
{
HandleConfirmation(packet);
}
else if (PacketHandlers.ContainsKey(id))
{
PacketHandlers[id](packet, endPoint, this);
}
else
{
Console.WriteLine("Warning: Unhandled internode network packet with ID {0}", id);
}
if ((flags & MessageFlags.PropegateTransaction) > 0 && endPoint.Address == IPAddress.Loopback)
{
foreach (var target in Network)
{
if (target != node)
{
Send(packet, target.EndPoint);
}
}
}
if ((flags & MessageFlags.ConfirmationRequired) > 0)
{
Send(new ConfirmationPacket(transaction), endPoint); // TODO: Don't re-handle duplicate transactions
}
}
}
else
{
Console.WriteLine("Warning: Received unknown internode network packet ID {0}", id);
}
}
catch (Exception e)
{
Console.WriteLine("Warning: Error parsing internetwork message: {0}", e.GetType().Name);
}
}
