fxfileobjectapikm.cpp

Go to the documentation of this file.

/*++
 
Copyright (c) Microsoft Corporation
 
Module Name:
 
    FxFileObjectApiUm.cpp
 
Abstract:
 
    This modules implements the C API's for the FxFileObject.
 
Author:
 
Environment:
 
    Kernel Mode mode only
 
Revision History:
 
 
--*/
 
#include "coreprivshared.hpp"
#include "fxfileobject.hpp"
 
extern "C" {
// #include "FxFileObjectApiKm.tmh"
}
 
//
// Extern "C" the entire file
//
extern "C" {
 
__drv_maxIRQL(DISPATCH_LEVEL)
PFILE_OBJECT
STDCALL
WDFEXPORT(WdfFileObjectWdmGetFileObject)(
    __in
    PWDF_DRIVER_GLOBALS DriverGlobals,
    __in
    WDFFILEOBJECT  FileObject
    )
/*++
 
Routine Description:
 
    This functions returns the corresponding WDM fileobject. If the device is opened
    by a kernel-mode componenet by sending a IRP_MJ_CREATE irp
    directly without a fileobject, this call can return a NULL pointer.
 
    Creating a WDFFILEOBJECT without an underlying WDM fileobject
    is done only for 'exclusive' devices.
 
    Serenum sends such a create-irp to the serial driver.
 
Arguments:
 
    FileObject - WDFFILEOBJECT
 
Return Value:
 
 
--*/
{
   DDI_ENTRY();
 
   FxFileObject* pFO;
 
   //
   // Validate the FileObject object handle, and get its FxFileObject*
   //
   FxObjectHandleGetPtr(GetFxDriverGlobals(DriverGlobals),
                        FileObject,
                        FX_TYPE_FILEOBJECT,
                        (PVOID*)&pFO);
 
   return pFO->GetWdmFileObject();
}
 
} // extern "C"