private bool HandleHandshake(TcpClient client, out NetworkStream stream, out Guid nodeId)
{
var clientEndpoint = (IPEndPoint)client.Client.RemoteEndPoint;
_log.Info("Got connection from {0}:{1}", clientEndpoint.Address, clientEndpoint.Port);
stream = client.GetStream();
var idBytes = new byte[16]; // GUID is 16 bytes
stream.Read(idBytes, 0, 16);
nodeId = new Guid(idBytes);
_log.Info("Node identified as: {0}", nodeId.ToString());
bool knownGuid = NodesPublicKeys.ContainsKey(nodeId);
if (!knownGuid && !AllowUnknownGuid)
{
_log.Warn("Node GUID not recognized, closing connection.");
stream.WriteSbyte((sbyte)HandshakeResult.UNKNOWN_GUID_NOT_ALLOWED);
stream.Close();
return(false);
}
else
{
if (knownGuid)
{
stream.WriteSbyte((sbyte)HandshakeResult.ACCEPTED);
}
else
{
stream.WriteSbyte((sbyte)HandshakeResult.UNKNOWN_GUID_ACCEPTED);
}
return(true);
}
}
private void HandleAsyncSendConnection(IAsyncResult result)
{
TcpListener listener = (TcpListener)result.AsyncState;
TcpClient client = listener.EndAcceptTcpClient(result);
NetworkStream stream;
Guid nodeId;
sendConnectionWaitHandle.Set(); //Inform the main thread this connection is now handled
if (HandleHandshake(client, out stream, out nodeId))
{
var nodeConnection = new NodeConnection()
{
Client = client,
Thread = Thread.CurrentThread,
CommandQueue = new ConcurrentQueue <QueuedCommand>()
};
nodeConnections.AddOrUpdate(nodeId, nodeConnection, (g, sc) =>
{
nodeConnection.CommandQueue = sc.CommandQueue; // Preserve the queue if it already exists
return(nodeConnection);
});
while (!aborted && client.Connected)
{
var commandQueue = nodeConnection.CommandQueue;
if (commandQueue.Count > 0) // Sending mode
{
if (!NodesPublicKeys.ContainsKey(nodeId))
{
_log.Info(String.Format("Cannot process queue. No public key for server {0}.", nodeId));
Thread.Sleep(1000);
}
else
{
_log.Debug("Processing command from queue...");
QueuedCommand serverCommand;
if (commandQueue.TryDequeue(out serverCommand))
{
try
{
handleRemoteCommand(stream, serverCommand);
}
catch (AggregateException ax)
{
ax.Handle((x) =>
{
if (x is System.Security.Cryptography.CryptographicException)
{
_log.Warn(x, $"Cryptographic communication error with node. Check encryption keys. Details: {x.Message}");
}
else
{
var ix = x.InnerException;
_log.Warn(x, $"Communication error with node. Requeueing command. Details: {x.Message}{(ix != null ? "; " + ix.Message : "")}");
commandQueue.Enqueue(serverCommand);
}
return(true);
});
}
stream.Close();
}
else
{
_log.Warn("Could not dequeue command!");
}
}
}
else
{
Thread.Sleep(1000);
}
}
}
}
