如何在 windows NT 驱动程序中获取符号 link 名称？

Question

我正在编写一个 windows nt 驱动程序。我定义了一个 DEVICE_EXTENSION

typedef struct _DEVICE_EXTENSION {
PDEVICE_OBJECT pDevice;
UNICODE_STRING ustrDeviceName;
UNICODE_STRING ustrSymLinkName;
} DEVICE_EXTENSION, *PDEVICE_EXTENSION;

然后我创建了一个设备，

status = IoCreateDevice(pDriverObject,
    sizeof(DEVICE_EXTENSION),
    &devName,
    FILE_DEVICE_UNKNOWN,
    0, TRUE,
    &pDevObj);
if (!NT_SUCCESS(status))
{ 
    DbgPrint("CreateDevice Error...\n");
    return status;
}
pDevObj->Flags |= DO_BUFFERED_IO;
pDevExt = (PDEVICE_EXTENSION)pDevObj->DeviceExtension;
pDevExt->pDevice = pDevObj;
pDevExt->ustrDeviceName = devName;

UNICODE_STRING symLinkName;
RtlInitUnicodeString(&symLinkName, DOS_DEVICE_NAME);
pDevExt->ustrSymLinkName = symLinkName;
status = IoCreateSymbolicLink(&symLinkName, &devName);

你可以看到，我把symLinkName存入了DEVICE_EXTENSIONpDevExt。当它从设备上卸载时，我读到这个 symLinkName

NTSTATUS status;
PDEVICE_OBJECT  pNextObj;
DbgPrint(("Enter DriverUnload\n"));
pNextObj = pDriverObject->DeviceObject;
UNICODE_STRING pLinkName;

while (pNextObj != NULL)
{
    PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)pNextObj->DeviceExtension;
    RtlCopyUnicodeString(&pLinkName, &(pDevExt->ustrSymLinkName));
    DbgPrint("Start delete symlinkname %wZ ...\n", &pLinkName);n // meet a error
    status = IoDeleteSymbolicLink(&pLinkName);
    if (!NT_SUCCESS(status))
    {
        DbgPrint("Delete SymbolLink Error\n");
        goto finish;
    }
    pNextObj = pNextObj->NextDevice;
    IoDeleteDevice(pDevExt->pDevice);
}

在执行IoDeleteSymbolicLink之前，我想打印这个pLinkName，但是我遇到了一个错误。

为了解决这个问题，我尝试了很多方法。

while (pNextObj != NULL)
{
    PDEVICE_EXTENSION pDevExt = (PDEVICE_EXTENSION)pNextObj->DeviceExtension;
    // RtlCopyUnicodeString(&pLinkName, &(pDevExt->ustrSymLinkName));
    RtlInitUnicodeString(&pLinkName, DOS_DEVICE_NAME);     
    DbgPrint("Start delete symlinkname %wZ ...\n", &pLinkName);
    status = IoDeleteSymbolicLink(&pLinkName);
    if (!NT_SUCCESS(status))
    {
        DbgPrint("Delete SymbolLink Error\n");
        goto finish;
    }
    pNextObj = pNextObj->NextDevice;
    IoDeleteDevice(pDevExt->pDevice);
}

这会执行成功，但我不知道为什么会这样。

Answer 1

我猜您在代码中使用了这个 #pragma alloc_text(INIT, DriverEntry)。如果是这样，这是解释：

/* 
 * These compiler directives tell the Operating System how to load the
 * driver into memory. The "INIT" section is discardable as you only
 * need the driver entry upon initialization, then it can be discarded.
 *
 */

加载后，INIT sesison 将被丢弃，如果您的 pDevExt->ustrSymLinkName 数据在该会话中，则该数据已被释放。您可以删除所有 #pragma alloc_text 以避免此问题。

如何在 windows NT 驱动程序中获取符号 link 名称？

How can I get symbol link name in windows NT driver?

c++

windows

driver