/*++ Copyright (c) 1996 Microsoft Corporation Module Name: pnp.c Abstract: NULL filter driver -- boilerplate code Author: ervinp Environment: Kernel mode Revision History: --*/ #include #include "filter.h" #ifdef ALLOC_PRAGMA #pragma alloc_text(PAGE, VA_PnP) #pragma alloc_text(PAGE, GetDeviceCapabilities) #endif NTSTATUS VA_PnP(struct DEVICE_EXTENSION *devExt, PIRP irp) /*++ Routine Description: Dispatch routine for PnP IRPs (MajorFunction == IRP_MJ_PNP) Arguments: devExt - device extension for the targetted device object irp - IO Request Packet Return Value: NT status code --*/ { PIO_STACK_LOCATION irpSp; NTSTATUS status = STATUS_SUCCESS; BOOLEAN completeIrpHere = FALSE; BOOLEAN justReturnStatus = FALSE; PAGED_CODE(); irpSp = IoGetCurrentIrpStackLocation(irp); DBGOUT(("VA_PnP, minorFunc = %d ", (ULONG)irpSp->MinorFunction)); switch (irpSp->MinorFunction){ case IRP_MN_START_DEVICE: DBGOUT(("START_DEVICE")); devExt->state = STATE_STARTING; /* * First, send the START_DEVICE irp down the stack * synchronously to start the lower stack. * We cannot do anything with our device object * before propagating the START_DEVICE this way. */ IoCopyCurrentIrpStackLocationToNext(irp); status = CallNextDriverSync(devExt, irp); if (NT_SUCCESS(status)){ /* * Now that the lower stack is started, * do any initialization required by this device object. */ status = GetDeviceCapabilities(devExt); if (NT_SUCCESS(status)){ devExt->state = STATE_STARTED; /* * Now that device is started, register with WMI */ IoWMIRegistrationControl(devExt->filterDevObj, WMIREG_ACTION_REGISTER); } else { devExt->state = STATE_START_FAILED; } } else { devExt->state = STATE_START_FAILED; } completeIrpHere = TRUE; break; case IRP_MN_QUERY_STOP_DEVICE: break; case IRP_MN_STOP_DEVICE: if (devExt->state == STATE_SUSPENDED){ status = STATUS_DEVICE_POWER_FAILURE; completeIrpHere = TRUE; } else { /* * Only set state to STOPPED if the device was * previously started successfully. */ if (devExt->state == STATE_STARTED){ devExt->state = STATE_STOPPED; } } break; case IRP_MN_QUERY_REMOVE_DEVICE: /* * We will pass this IRP down the driver stack. * However, we need to change the default status * from STATUS_NOT_SUPPORTED to STATUS_SUCCESS. */ irp->IoStatus.Status = STATUS_SUCCESS; break; case IRP_MN_SURPRISE_REMOVAL: DBGOUT(("SURPRISE_REMOVAL")); /* * We will pass this IRP down the driver stack. * However, we need to change the default status * from STATUS_NOT_SUPPORTED to STATUS_SUCCESS. */ irp->IoStatus.Status = STATUS_SUCCESS; /* * For now just set the STATE_REMOVING state so that * we don't do any more IO. We are guaranteed to get * IRP_MN_REMOVE_DEVICE soon; we'll do the rest of * the remove processing there. */ devExt->state = STATE_REMOVING; break; case IRP_MN_REMOVE_DEVICE: /* * Check the current state to guard against multiple * REMOVE_DEVICE IRPs. */ DBGOUT(("REMOVE_DEVICE")); if (devExt->state != STATE_REMOVED){ devExt->state = STATE_REMOVED; /* * Send the REMOVE IRP down the stack asynchronously. * Do not synchronize sending down the REMOVE_DEVICE * IRP, because the REMOVE_DEVICE IRP must be sent * down and completed all the way back up to the sender * before we continue. */ IoCopyCurrentIrpStackLocationToNext(irp); status = IoCallDriver(devExt->physicalDevObj, irp); justReturnStatus = TRUE; DBGOUT(("REMOVE_DEVICE - waiting for %d irps to complete...", devExt->pendingActionCount)); /* * We must for all outstanding IO to complete before * completing the REMOVE_DEVICE IRP. * * First do an extra decrement on the pendingActionCount. * This will cause pendingActionCount to eventually * go to -1 once all asynchronous actions on this * device object are complete. * Then wait on the event that gets set when the * pendingActionCount actually reaches -1. */ DecrementPendingActionCount(devExt); KeWaitForSingleObject( &devExt->removeEvent, Executive, // wait reason KernelMode, FALSE, // not alertable NULL ); // no timeout DBGOUT(("REMOVE_DEVICE - ... DONE waiting. ")); /* * Now that the device is going away unregister with WMI * Note that we wait until all WMI irps are completed * before unregistering since unregistering will block * until all WMI irps are completed. */ IoWMIRegistrationControl(devExt->filterDevObj, WMIREG_ACTION_DEREGISTER); /* * Detach our device object from the lower * device object stack. */ IoDetachDevice(devExt->topDevObj); /* * Delete our device object. * This will also delete the associated device extension. */ IoDeleteDevice(devExt->filterDevObj); } break; case IRP_MN_QUERY_DEVICE_RELATIONS: case IRP_MN_QUERY_PNP_DEVICE_STATE: default: break; } if (justReturnStatus){ /* * We've already sent this IRP down the stack asynchronously. */ } else if (completeIrpHere){ irp->IoStatus.Status = status; IoCompleteRequest(irp, IO_NO_INCREMENT); } else { IoCopyCurrentIrpStackLocationToNext(irp); status = IoCallDriver(devExt->physicalDevObj, irp); } return status; } NTSTATUS GetDeviceCapabilities(struct DEVICE_EXTENSION *devExt) /*++ Routine Description: Function retrieves the DEVICE_CAPABILITIES descriptor from the device Arguments: devExt - device extension for targetted device object Return Value: NT status code --*/ { NTSTATUS status; PIRP irp; PAGED_CODE(); irp = IoAllocateIrp(devExt->physicalDevObj->StackSize, FALSE); if (irp){ PIO_STACK_LOCATION nextSp = IoGetNextIrpStackLocation(irp); nextSp->MajorFunction = IRP_MJ_PNP; nextSp->MinorFunction = IRP_MN_QUERY_CAPABILITIES; RtlZeroMemory( &devExt->deviceCapabilities, sizeof(DEVICE_CAPABILITIES)); nextSp->Parameters.DeviceCapabilities.Capabilities = &devExt->deviceCapabilities; /* * For any IRP you create, you must set the default status * to STATUS_NOT_SUPPORTED before sending it. */ irp->IoStatus.Status = STATUS_NOT_SUPPORTED; status = CallNextDriverSync(devExt, irp); IoFreeIrp(irp); } else { status = STATUS_INSUFFICIENT_RESOURCES; } ASSERT(NT_SUCCESS(status)); return status; }