/// <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(IncomingClient Client) { MessageBuilder mb = new MessageBuilder(0, new List <SemVer>() { SemVer.V100 }, null); Message response = mb.CreateErrorProtocolViolationResponse(new Message() { Id = 0x0BADC0DE }); await Client.SendMessageAsync(response); }
/// <summary> /// Processing of a message received from a client. /// </summary> /// <param name="Client">TCP client who send the message.</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(IncomingClient Client, Message IncomingMessage) { MessageBuilder messageBuilder = Client.MessageBuilder; 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: { Message responseMessage = messageBuilder.CreateErrorProtocolViolationResponse(IncomingMessage); Request request = IncomingMessage.Request; log.Trace("Request conversation type is {0}.", request.ConversationTypeCase); switch (request.ConversationTypeCase) { case Request.ConversationTypeOneofCase.SingleRequest: { SingleRequest singleRequest = request.SingleRequest; SemVer version = new SemVer(singleRequest.Version); log.Trace("Single request type is {0}, version is {1}.", singleRequest.RequestTypeCase, version); if (!version.IsValid()) { responseMessage.Response.Details = "version"; break; } switch (singleRequest.RequestTypeCase) { case SingleRequest.RequestTypeOneofCase.Ping: responseMessage = ProcessMessagePingRequest(Client, IncomingMessage); break; case SingleRequest.RequestTypeOneofCase.ListRoles: responseMessage = ProcessMessageListRolesRequest(Client, IncomingMessage); break; default: log.Warn("Invalid request type '{0}'.", singleRequest.RequestTypeCase); break; } break; } case Request.ConversationTypeOneofCase.ConversationRequest: { ConversationRequest conversationRequest = request.ConversationRequest; log.Trace("Conversation request type is {0}.", conversationRequest.RequestTypeCase); if (conversationRequest.Signature.Length > 0) { log.Trace("Conversation signature is '{0}'.", Crypto.ToHex(conversationRequest.Signature.ToByteArray())); } else { log.Trace("No signature provided."); } switch (conversationRequest.RequestTypeCase) { case ConversationRequest.RequestTypeOneofCase.Start: responseMessage = ProcessMessageStartConversationRequest(Client, IncomingMessage); break; case ConversationRequest.RequestTypeOneofCase.VerifyIdentity: responseMessage = ProcessMessageVerifyIdentityRequest(Client, IncomingMessage); break; case ConversationRequest.RequestTypeOneofCase.StartNeighborhoodInitialization: responseMessage = ProcessMessageStartNeighborhoodInitializationRequest(Client, IncomingMessage); break; case ConversationRequest.RequestTypeOneofCase.FinishNeighborhoodInitialization: responseMessage = ProcessMessageFinishNeighborhoodInitializationRequest(Client, IncomingMessage); break; case ConversationRequest.RequestTypeOneofCase.NeighborhoodSharedProfileUpdate: responseMessage = ProcessMessageNeighborhoodSharedProfileUpdateRequest(Client, IncomingMessage); break; case ConversationRequest.RequestTypeOneofCase.StopNeighborhoodUpdates: responseMessage = ProcessMessageStopNeighborhoodUpdatesRequest(Client, IncomingMessage); break; default: log.Warn("Invalid request type '{0}'.", conversationRequest.RequestTypeCase); // Connection will be closed in ReceiveMessageLoop. break; } break; } default: log.Error("Unknown conversation type '{0}'.", request.ConversationTypeCase); // Connection will be closed in ReceiveMessageLoop. break; } if (responseMessage != null) { // Send response to client. res = await Client.SendMessageAsync(responseMessage); } 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}', conversation type is {2}.", response.Status, response.Details, response.ConversationTypeCase); // Find associated request. If it does not exist, disconnect the client as it // send a response without receiving a request. This is protocol violation, // but as this is a reponse, we have no how to inform the client about it, // so we just disconnect it. UnfinishedRequest unfinishedRequest = Client.GetAndRemoveUnfinishedRequest(IncomingMessage.Id); if ((unfinishedRequest != null) && (unfinishedRequest.RequestMessage != null)) { Message requestMessage = unfinishedRequest.RequestMessage; Request request = requestMessage.Request; // We now check whether the response message type corresponds with the request type. // This is only valid if the status is Ok. If the message types do not match, we disconnect // for the protocol violation again. bool typeMatch = false; bool isErrorResponse = response.Status != Status.Ok; if (!isErrorResponse) { if (response.ConversationTypeCase == Response.ConversationTypeOneofCase.SingleResponse) { typeMatch = (request.ConversationTypeCase == Request.ConversationTypeOneofCase.SingleRequest) && ((int)response.SingleResponse.ResponseTypeCase == (int)request.SingleRequest.RequestTypeCase); } else { typeMatch = (request.ConversationTypeCase == Request.ConversationTypeOneofCase.ConversationRequest) && ((int)response.ConversationResponse.ResponseTypeCase == (int)request.ConversationRequest.RequestTypeCase); } } else { typeMatch = true; } if (typeMatch) { // Now we know the types match, so we can rely on request type even if response is just an error. switch (request.ConversationTypeCase) { case Request.ConversationTypeOneofCase.SingleRequest: { SingleRequest singleRequest = request.SingleRequest; switch (singleRequest.RequestTypeCase) { default: log.Warn("Invalid conversation type '{0}' of the corresponding request.", request.ConversationTypeCase); // Connection will be closed in ReceiveMessageLoop. break; } break; } case Request.ConversationTypeOneofCase.ConversationRequest: { ConversationRequest conversationRequest = request.ConversationRequest; switch (conversationRequest.RequestTypeCase) { case ConversationRequest.RequestTypeOneofCase.NeighborhoodSharedProfileUpdate: res = ProcessMessageNeighborhoodSharedProfileUpdateResponse(Client, IncomingMessage, unfinishedRequest); break; case ConversationRequest.RequestTypeOneofCase.FinishNeighborhoodInitialization: res = ProcessMessageFinishNeighborhoodInitializationResponse(Client, IncomingMessage, unfinishedRequest); break; default: log.Warn("Invalid type '{0}' of the corresponding request.", conversationRequest.RequestTypeCase); // Connection will be closed in ReceiveMessageLoop. break; } break; } default: log.Error("Unknown conversation type '{0}' of the corresponding request.", request.ConversationTypeCase); // Connection will be closed in ReceiveMessageLoop. break; } } else { log.Warn("Message type of the response ID {0} does not match the message type of the request ID {1}, the connection will be closed.", IncomingMessage.Id); // Connection will be closed in ReceiveMessageLoop. } } else { log.Warn("No unfinished request found for incoming response ID {0}, the connection will be closed.", IncomingMessage.Id); // Connection will be closed in ReceiveMessageLoop. } 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. } if (res && Client.ForceDisconnect) { log.Debug("Connection to the client will be forcefully closed."); res = false; } profileServer.AddMessage(IncomingMessage, Client.ServerRole, res ? Client : null); log.Debug("(-):{0}", res); return(res); }