/// <summary>
/// Reads and decodes message from the stream from LOC server.
/// </summary>
/// <param name="CancellationToken">Cancallation token for async calls.</param>
/// <param name="CheckProtocolViolation">If set to true, the function checks whether a protocol violation occurred and if so, it sends protocol violation error to the peer.</param>
/// <returns>Received message of null if the function fails.</returns>
public async Task <LocProtocolMessage> ReceiveMessageAsync(CancellationToken CancellationToken, bool CheckProtocolViolation = false)
{
log.Trace("()");
LocProtocolMessage res = null;
RawMessageResult rawMessage = await messageReader.ReceiveMessageAsync(CancellationToken);
if (rawMessage.Data != null)
{
res = (LocProtocolMessage)LocMessageBuilder.CreateMessageFromRawData(rawMessage.Data);
}
else
{
log.Debug("Connection to LOC server has been terminated.");
}
if (CheckProtocolViolation)
{
if ((res == null) || rawMessage.ProtocolViolation)
{
await messageProcessor.SendProtocolViolation(this);
}
}
log.Trace("(-):{0}", res != null ? "LocProtocolMessage" : "null");
return(res);
}
/// <summary>
/// Sends ERROR_PROTOCOL_VIOLATION to client with message ID set to 0x0BADC0DE.
/// </summary>
/// <param name="Client">Client to send the error to.</param>
public async Task SendProtocolViolation(ClientBase Client)
{
LocMessageBuilder mb = new LocMessageBuilder(0, new List <SemVer> {
SemVer.V100
});
LocProtocolMessage response = mb.CreateErrorProtocolViolationResponse(new LocProtocolMessage(new Message()
{
Id = 0x0BADC0DE
}));
await Client.SendMessageAsync(response);
}
/// <summary>
/// Initialize the object.
/// </summary>
/// <param name="ServerEndPoint">LOC server address and port.</param>
public LocClient(IPEndPoint ServerEndPoint, IMessageProcessor MessageProcessor, ComponentShutdown ShutdownSignaling) :
base(ServerEndPoint, false)
{
log = new Logger("IopServerCore.Network.LOC.LocClient");
log.Trace("(ServerEndPoint:'{0}')", ServerEndPoint);
config = (ConfigBase)Base.ComponentDictionary[ConfigBase.ComponentName];
messageBuilder = new LocMessageBuilder(0, new List <SemVer> {
SemVer.V100
});
messageProcessor = MessageProcessor;
shutdownSignaling = ShutdownSignaling;
log.Trace("(-)");
}
/// <summary>
/// Reads messages from the client stream and processes them in a loop until the client disconnects
/// or until an action (such as a protocol violation) that leads to disconnecting of the client occurs.
/// </summary>
/// <param name="Client">TCP client.</param>
/// <param name="MessageBuilder">Client's message builder.</param>
public async Task ReceiveMessageLoop(TcpClient Client, LocMessageBuilder MessageBuilder)
{
log.Trace("()");
try
{
NetworkStream stream = Client.GetStream();
RawMessageReader messageReader = new RawMessageReader(stream);
while (!isShutdown)
{
RawMessageResult rawMessage = await messageReader.ReceiveMessageAsync(shutdownCancellationTokenSource.Token);
bool disconnect = rawMessage.Data == null;
bool protocolViolation = rawMessage.ProtocolViolation;
if (rawMessage.Data != null)
{
LocProtocolMessage message = (LocProtocolMessage)LocMessageBuilder.CreateMessageFromRawData(rawMessage.Data);
if (message != null)
{
disconnect = !await ProcessMessageAsync(Client, MessageBuilder, message);
}
else
{
protocolViolation = true;
}
}
if (protocolViolation)
{
await SendProtocolViolation(Client);
break;
}
if (disconnect)
{
break;
}
}
}
catch (Exception e)
{
log.Error("Exception occurred: {0}", e.ToString());
}
log.Trace("(-)");
}
/// <summary>
/// Sends a message to the client over the open network stream.
/// </summary>
/// <param name="Client">TCP client.</param>
/// <param name="Message">Message to send.</param>
/// <returns>true if the message was sent successfully to the target recipient.</returns>
private async Task <bool> SendMessageInternalAsync(TcpClient Client, LocProtocolMessage Message)
{
log.Trace("()");
bool res = false;
string msgStr = Message.ToString();
log.Trace("Sending message:\n{0}", msgStr);
byte[] responseBytes = LocMessageBuilder.MessageToByteArray(Message);
await StreamWriteLock.WaitAsync();
try
{
NetworkStream stream = Client.GetStream();
if (stream != null)
{
await stream.WriteAsync(responseBytes, 0, responseBytes.Length);
res = true;
}
else
{
log.Info("Connection to the client has been terminated.");
}
}
catch (IOException)
{
log.Info("Connection to the client has been terminated.");
}
finally
{
StreamWriteLock.Release();
}
log.Trace("(-):{0}", res);
return(res);
}
/// <summary>
/// Handler for each client that connects to the TCP server.
/// </summary>
/// <param name="Client">Client that is connected to TCP server.</param>
private async void ClientHandlerAsync(TcpClient Client)
{
LogDiagnosticContext.Start();
log.Debug("(Client.Client.RemoteEndPoint:{0})", Client.Client.RemoteEndPoint);
connectedProfileServer = Client;
connectedProfileServerMessageBuilder = new LocMessageBuilder(0, new List <SemVer>()
{
SemVer.V100
});
await ReceiveMessageLoop(Client, connectedProfileServerMessageBuilder);
connectedProfileServerWantsUpdates = false;
connectedProfileServer = null;
Client.Dispose();
log.Debug("(-)");
LogDiagnosticContext.Stop();
}
/// <summary>
/// Converts an IoP Network protocol message to a binary format.
/// </summary>
/// <param name="Message">IoP Network protocol message.</param>
/// <returns>Binary representation of the message to be sent over the network.</returns>
public override byte[] MessageToByteArray(IProtocolMessage Message)
{
return(LocMessageBuilder.MessageToByteArray(Message));
}
/// <summary>
/// Constructs ProtoBuf message from raw data read from the network stream.
/// </summary>
/// <param name="Data">Raw data to be decoded to the message.</param>
/// <returns>ProtoBuf message or null if the data do not represent a valid message.</returns>
public override IProtocolMessage CreateMessageFromRawData(byte[] Data)
{
return((IProtocolMessage)LocMessageBuilder.CreateMessageFromRawData(Data));
}
/// <summary>
/// Processes DeregisterServiceRequest message from client.
/// <para>Removes information about the profile server's NodeProfile.</para>
/// </summary>
/// <param name="Client">TCP client that sent the request.</param>
/// <param name="MessageBuilder">Client's message builder.</param>
/// <param name="RequestMessage">Full request message.</param>
/// <returns>Response message to be sent to the client.</returns>
public LocProtocolMessage ProcessMessageDeregisterServiceRequest(TcpClient Client, LocMessageBuilder MessageBuilder, LocProtocolMessage RequestMessage)
{
log.Trace("()");
LocProtocolMessage res = MessageBuilder.CreateDeregisterServiceResponse(RequestMessage);
DeregisterServiceRequest deregisterServiceRequest = RequestMessage.Request.LocalService.DeregisterService;
profileServer.Uninitialize();
log.Trace("(-):*.Response.Status={0}", res.Response.Status);
return(res);
}
/// <summary>
/// Processes RegisterServiceRequest message from client.
/// <para>Obtains information about the profile server's NodeProfile.</para>
/// </summary>
/// <param name="Client">TCP client that sent the request.</param>
/// <param name="MessageBuilder">Client's message builder.</param>
/// <param name="RequestMessage">Full request message.</param>
/// <returns>Response message to be sent to the client.</returns>
public LocProtocolMessage ProcessMessageRegisterServiceRequest(TcpClient Client, LocMessageBuilder MessageBuilder, LocProtocolMessage RequestMessage)
{
log.Trace("()");
LocProtocolMessage res = MessageBuilder.CreateRegisterServiceResponse(RequestMessage);
RegisterServiceRequest registerServiceRequest = RequestMessage.Request.LocalService.RegisterService;
byte[] serverId = registerServiceRequest.Service.ServiceData.ToByteArray();
if ((registerServiceRequest.Service.Type == ServiceType.Profile) && (serverId.Length == 32))
{
profileServer.SetNetworkId(serverId);
}
else
{
log.Error("Received register service request is invalid.");
}
log.Trace("(-):*.Response.Status={0}", res.Response.Status);
return(res);
}
/// <summary>
/// Processes GetNeighbourNodesByDistanceLocalRequest message from client.
/// <para>Obtains information about the profile server's neighborhood and initiates sending updates to it.</para>
/// </summary>
/// <param name="Client">TCP client that sent the request.</param>
/// <param name="MessageBuilder">Client's message builder.</param>
/// <param name="RequestMessage">Full request message.</param>
/// <param name="KeepAlive">This is set to true if KeepAliveAndSendUpdates in the request was set.</param>
/// <returns>Response message to be sent to the client.</returns>
public LocProtocolMessage ProcessMessageGetNeighbourNodesByDistanceLocalRequest(TcpClient Client, LocMessageBuilder MessageBuilder, LocProtocolMessage RequestMessage, out bool KeepAlive)
{
log.Trace("()");
LocProtocolMessage res = null;
GetNeighbourNodesByDistanceLocalRequest getNeighbourNodesByDistanceLocalRequest = RequestMessage.Request.LocalService.GetNeighbourNodes;
KeepAlive = getNeighbourNodesByDistanceLocalRequest.KeepAliveAndSendUpdates;
List <NodeInfo> neighborList = new List <NodeInfo>();
lock (neighborsLock)
{
foreach (ProfileServer ps in neighbors.Values)
{
NodeInfo ni = ps.GetNodeInfo();
neighborList.Add(ni);
}
}
res = MessageBuilder.CreateGetNeighbourNodesByDistanceLocalResponse(RequestMessage, neighborList);
log.Trace("(-):*.Response.Status={0}", res.Response.Status);
return(res);
}
/// <summary>
/// Processing of a message received from a client.
/// </summary>
/// <param name="Client">TCP client.</param>
/// <param name="MessageBuilder">Client's message builder.</param>
/// <param name="IncomingMessage">Full ProtoBuf message to be processed.</param>
/// <returns>true if the conversation with the client should continue, false if a protocol violation error occurred and the client should be disconnected.</returns>
public async Task <bool> ProcessMessageAsync(TcpClient Client, LocMessageBuilder MessageBuilder, LocProtocolMessage IncomingMessage)
{
bool res = false;
log.Debug("()");
try
{
log.Trace("Received message type is {0}, message ID is {1}.", IncomingMessage.MessageTypeCase, IncomingMessage.Id);
switch (IncomingMessage.MessageTypeCase)
{
case Message.MessageTypeOneofCase.Request:
{
LocProtocolMessage responseMessage = MessageBuilder.CreateErrorProtocolViolationResponse(IncomingMessage);
Request request = IncomingMessage.Request;
bool setKeepAlive = false;
SemVer version = new SemVer(request.Version);
log.Trace("Request type is {0}, version is {1}.", request.RequestTypeCase, version);
switch (request.RequestTypeCase)
{
case Request.RequestTypeOneofCase.LocalService:
{
log.Trace("Local service request type is {0}.", request.LocalService.LocalServiceRequestTypeCase);
switch (request.LocalService.LocalServiceRequestTypeCase)
{
case LocalServiceRequest.LocalServiceRequestTypeOneofCase.RegisterService:
responseMessage = ProcessMessageRegisterServiceRequest(Client, MessageBuilder, IncomingMessage);
break;
case LocalServiceRequest.LocalServiceRequestTypeOneofCase.DeregisterService:
responseMessage = ProcessMessageDeregisterServiceRequest(Client, MessageBuilder, IncomingMessage);
break;
case LocalServiceRequest.LocalServiceRequestTypeOneofCase.GetNeighbourNodes:
responseMessage = ProcessMessageGetNeighbourNodesByDistanceLocalRequest(Client, MessageBuilder, IncomingMessage, out setKeepAlive);
break;
default:
log.Error("Invalid local service request type '{0}'.", request.LocalService.LocalServiceRequestTypeCase);
break;
}
break;
}
default:
log.Error("Invalid request type '{0}'.", request.RequestTypeCase);
break;
}
if (responseMessage != null)
{
// Send response to client.
res = await SendMessageAsync(Client, responseMessage);
if (res)
{
// If the message was sent successfully to the target, we close the connection only in case of protocol violation error.
if (responseMessage.MessageTypeCase == Message.MessageTypeOneofCase.Response)
{
res = responseMessage.Response.Status != Status.ErrorProtocolViolation;
}
}
if (res && setKeepAlive)
{
connectedProfileServerWantsUpdates = true;
log.Debug("Profile server '{0}' is now connected to its LOC server and waiting for updates.", profileServer.Name);
}
}
else
{
// If there is no response to send immediately to the client,
// we want to keep the connection open.
res = true;
}
break;
}
case Message.MessageTypeOneofCase.Response:
{
Response response = IncomingMessage.Response;
log.Trace("Response status is {0}, details are '{1}', response type is {2}.", response.Status, response.Details, response.ResponseTypeCase);
switch (response.ResponseTypeCase)
{
case Response.ResponseTypeOneofCase.LocalService:
{
log.Trace("Local service response type is {0}.", response.LocalService.LocalServiceResponseTypeCase);
switch (response.LocalService.LocalServiceResponseTypeCase)
{
case LocalServiceResponse.LocalServiceResponseTypeOneofCase.NeighbourhoodUpdated:
// Nothing to be done here.
res = true;
break;
default:
log.Error("Invalid local service response type '{0}'.", response.LocalService.LocalServiceResponseTypeCase);
break;
}
break;
}
default:
log.Error("Unknown response type '{0}'.", response.ResponseTypeCase);
// Connection will be closed in ReceiveMessageLoop.
break;
}
break;
}
default:
log.Error("Unknown message type '{0}', connection to the client will be closed.", IncomingMessage.MessageTypeCase);
await SendProtocolViolation(Client);
// Connection will be closed in ReceiveMessageLoop.
break;
}
}
catch (Exception e)
{
log.Error("Exception occurred, connection to the client will be closed: {0}", e.ToString());
await SendProtocolViolation(Client);
// Connection will be closed in ReceiveMessageLoop.
}
log.Debug("(-):{0}", res);
return(res);
}