PDO與FDO

在WDM的架構當中，
PDO如何得知上層FDO
->透過AttachedDevice 子欄位
ex:
PDEVICE_OBJECT pDevice = pDriverObject->DeviceObject;
pDevice->AttachedDevice

FDO如何得知下層的裝置
->透過裝置擴充紀錄
ex:
typedef struct _DEVICE_EXTENSION
{
PDEVICE_OBJECT fdo;
PDEVICE_OBJECT NextStackDevice;
UNICODE_STRING ustrDeviceName; // 裝置名
UNICODE_STRING ustrSymLinkName; // 符號連結名
} DEVICE_EXTENSION, *PDEVICE_EXTENSION;

PDEVICE_EXTENSION pdx = (PDEVICE_EXTENSION)fdo->DeviceExtension;
pdx->NextStackDevice = IoAttachDeviceToDeviceStack(fdo, PhysicalDeviceObject);