/// <summary> /// Create global events necessary for handshaking with the parent /// </summary> /// <param name="nodeNumber"></param> /// <returns>True if events created successfully and false otherwise</returns> private static bool CreateGlobalEvents(int nodeNumber) { bool createdNew = false; if (NativeMethods.IsUserAdministrator()) { EventWaitHandleSecurity mSec = new EventWaitHandleSecurity(); // Add a rule that grants the access only to admins and systems mSec.SetSecurityDescriptorSddlForm(NativeMethods.ADMINONLYSDDL); // Create an initiation event to allow the parent side to prove to the child that we have the same level of privilege as it does. // this is done by having the parent set this event which means it needs to have administrative permissions to do so. globalInitiateActivationEvent = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeInitiateActivationEventName(nodeNumber), out createdNew, mSec); } else { // Create an initiation event to allow the parent side to prove to the child that we have the same level of privilege as it does. // this is done by having the parent set this event which means it has atleast the same permissions as the child process globalInitiateActivationEvent = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeInitiateActivationEventName(nodeNumber), out createdNew); } // This process must be the creator of the event to prevent squating by a lower privilaged attacker if (!createdNew) { return(false); } // Informs the parent process that the child process has been created. globalNodeActive = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeActiveEventName(nodeNumber)); globalNodeActive.Set(); // Indicate to the parent process, this node is currently is ready to start to recieve requests globalNodeInUse = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeInUseEventName(nodeNumber)); // Used by the parent process to inform the child process to shutdown due to the child process // not recieving the initialization command. globalNodeErrorShutdown = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeErrorShutdownEventName(nodeNumber)); // Inform the parent process the node has started its communication threads. globalNodeActivate = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeActivedEventName(nodeNumber)); return(true); }
/// <summary> /// This function establishes communication with a node given an index. If a node /// is not running it is launched. /// </summary> private void InitializeNode(int nodeIndex) { bool nodeConnected = false; int restartCount = 0; try { IncreaseActiveNodeCount(); while (!nodeConnected && restartCount < maximumNodeRestartCount) { if (!checkIfNodeActive(nodeData[nodeIndex].NodeNumber)) { // Attempt to launch a new node process LaunchNode(nodeIndex); // If we could not launch the node there is no reason to continue if (nodeData[nodeIndex].CommunicationFailed) { break; } } if (checkIfNodeActive(nodeData[nodeIndex].NodeNumber)) { nodeData[nodeIndex].SharedMemoryToNode.Reset(); nodeData[nodeIndex].SharedMemoryFromNode.Reset(); // Activate the initiation event to prove to the child that we have the same level of privilege as it does. This operation will not fail because each privilege level creates // events in different namespaces EventWaitHandle nodeInitiateActivationEvent = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeInitiateActivationEventName(nodeData[nodeIndex].NodeNumber)); nodeInitiateActivationEvent.Set(); nodeInitiateActivationEvent.Close(); // Wait for node to indicate that it is activated EventWaitHandle nodeActivatedEvent = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeActivedEventName(nodeData[nodeIndex].NodeNumber)); nodeActivatedEvent.WaitOne(initializationTimeout, false); nodeActivatedEvent.Close(); // Looked in Environment.cs the IDictionary is a HashTable IDictionary variableDictionary = Environment.GetEnvironmentVariables(); Hashtable environmentVariablesTable = new Hashtable(variableDictionary); LocalCallDescriptorForInitializeNode callDescriptorInit = new LocalCallDescriptorForInitializeNode(environmentVariablesTable, nodeLoggers.ToArray(), nodeData[nodeIndex].NodeId, parentGlobalProperties, toolsetSearchLocations, Process.GetCurrentProcess().Id, startupDirectory); nodeData[nodeIndex].NodeCommandQueue.Enqueue(callDescriptorInit); EventWaitHandle nodeInUseEvent = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeInUseEventName(nodeData[nodeIndex].NodeNumber)); // Wait for node to indicate that it is ready. The node may time out and exit, between // when we check that it is active and before the initialization messages reaches it. // In that rare case we have to restart the node. if (nodeInUseEvent.WaitOne(initializationTimeout, false)) { UpdateSettings(nodeIndex); nodeConnected = true; } nodeInUseEvent.Close(); // If the node is still active and has not replied to the initialization message it must // be in bad state - try to get that node to exit if (!nodeConnected && checkIfNodeActive(nodeData[nodeIndex].NodeNumber)) { EventWaitHandle nodeShutdownEvent = new EventWaitHandle(false, EventResetMode.ManualReset, LocalNodeProviderGlobalNames.NodeErrorShutdownEventName(nodeData[nodeIndex].NodeNumber)); nodeShutdownEvent.Set(); nodeShutdownEvent.Close(); restartCount = maximumNodeRestartCount; } restartCount++; } } } finally { // Make sure to decrement the active node count if the communication has failed if (nodeConnected != true) { DecreaseActiveNodeCount(nodeData[nodeIndex].NodeId); nodeData[nodeIndex].CommunicationFailed = true; } } }