//+----------------------------------------------------------------------------
//
//  Copyright (C) 1996, Microsoft Corporation
//
//  File:       create.c
//
//  Contents:   Implements the Create code for the Dfs server. The Dfs server
//              only allows opening the File System Device object for the
//              express purpose of FsControlling to the Dfs server.
//
//  Classes:
//
//  Functions:  DfsFsdCreate
//              DfsOpenDevice
//
//-----------------------------------------------------------------------------

#include "dfsprocs.h"
#include "attach.h"

//
//  The debug trace level
//

#define Dbg                              (DEBUG_TRACE_CREATE)

//
//  Local procedure prototypes
//

NTSTATUS
DfsOpenDevice (
    IN PFILE_OBJECT FileObject,
    IN PDEVICE_OBJECT DeviceObject,
    IN ULONG CreateOptions);


#ifdef ALLOC_PRAGMA

#pragma alloc_text( PAGE, DfsFsdCreate )
#pragma alloc_text( PAGE, DfsOpenDevice )

#endif // ALLOC_PRAGMA



//+-------------------------------------------------------------------
//
//  Function:   DfsFsdCreate, public
//
//  Synopsis:   This routine implements the FSD part of the NtCreateFile
//              and NtOpenFile API calls.
//
//  Arguments:  [DeviceObject] -- Supplies the device object relative to which
//                      the open is to be processed.
//              [Irp] - Supplies the Irp being processed.
//
//  Returns:    NTSTATUS - The Fsd status for the Irp
//
//--------------------------------------------------------------------

NTSTATUS
DfsFsdCreate (
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp
    )
{
    NTSTATUS            status;
    PIO_STACK_LOCATION  irpSp = IoGetCurrentIrpStackLocation(Irp);
    PFILE_OBJECT        fileObject;
    ULONG               createOptions;

    DebugTrace(+1, Dbg, "DfsFsdCreate: Entered\n", 0);

    ASSERT(IoIsOperationSynchronous(Irp) == TRUE);

    //
    // If someone is coming in via a device object attached to a file system
    // device object, pass it through.
    //

    if (DeviceObject->DeviceType == FILE_DEVICE_DISK_FILE_SYSTEM) {

        status = DfsVolumePassThrough(DeviceObject, Irp);

        DebugTrace(-1, Dbg, "DfsFsdCreate: FS Device Pass Through Exit %08lx\n", status);

        return status;

    }

    //
    // If someone is coming in via a device object attached to a file system
    // volume, we need to see if they are opening an exit point via its local
    // file system name.
    //

    if (DeviceObject->DeviceType == FILE_DEVICE_DFS_VOLUME) {

        status = DfsOpenFile(DeviceObject, Irp);

        DebugTrace(-1, Dbg, "DfsFsdCreate: Local File Open Exit %08lx\n', status);

        return status;
    }

    //
    // The only other create we handle is someone trying to open our own
    // file system device object.
    //

    ASSERT(DeviceObject->DeviceType == FILE_DEVICE_DFS_FILE_SYSTEM);

    FsRtlEnterFileSystem();

    fileObject = irpSp->FileObject;
    createOptions     = irpSp->Parameters.Create.Options;

    if (fileObject->FileName.Length == 0 &&
            fileObject->RelatedFileObject == NULL) {

        //
        // This is the only case we handle
        //

        status = DfsOpenDevice(
                    fileObject,
                    DeviceObject,
                    createOptions);

    } else {

        status = STATUS_INVALID_DEVICE_REQUEST;

    }

    FsRtlExitFileSystem();

    //
    //  And return to our caller
    //

    DebugTrace(-1, Dbg, "DfsFsdCreate: Exit -> %08lx\n", status );

    DfsCompleteRequest( Irp, status );

    return status;
}


//+----------------------------------------------------------------------------
//
//  Function:   DfsOpenFile, local
//
//  Synopsis:   This routine handles file opens that come in via attached
//              volumes. The semantics of this open are:
//
//              If the named file is a child of a DfsExitPath, fail it
//              with access denied.
//
//              If the named file is a DfsExitPath, and CreateOptions specify
//              DELETE_ON_CLOSE, fail it with access denied.
//
//              In all other cases, allocate an FCB, and pass the open through
//              to the underlying FS. If the open succeeds, then insert the
//              FCB in our FCB table. If the open fails, destroy the FCB.
//
//  Arguments:  [DeviceObject] -- The attached device object through which
//                      the Create Irp came in.
//
//              [Irp] -- The Create Irp.
//
//  Returns:    [STATUS_INSUFFICIENT_RESOURCES] -- Unable to allocate an FCB.
//
//              [STATUS_ACCESS_DENIED] -- The file is a child of a Dfs exit
//                      path or the file is a Dfs exit path and
//                      DELETE_ON_CLOSE was specified.
//
//              Status from the underlying FS.
//
//-----------------------------------------------------------------------------

NTSTATUS
DfsOpenFile(
    IN PDEVICE_OBJECT DeviceObject,
    IN PIRP Irp)
{
    NTSTATUS            status;
    PIO_STACK_LOCATION  irpSp = IoGetCurrentIrpStackLocation(Irp);
    PFILE_OBJECT        fileObject = irpSp->FileObject;
    ULONG               createOptions = irpSp->Parameters.Create.Options;

    DebugTrace(+1, Dbg, "DfsOpenFile - Entered\n", 0);

    if (fileObject->RelatedFileObject) {

        DebugTrace(0,
    }
}


//+-------------------------------------------------------------------
//
//  Function:   DfsOpenDevice, local
//
//  Synopsis:   This routine opens the specified device for direct
//              access.
//
//  Arguments:  [FileObject] - Supplies the File object
//              [DeviceObject] - Supplies the object denoting the device
//                      being opened
//              [CreateOptions] - Supplies the create options for
//                      this operation
//
//  Returns:    [IO_STATUS_BLOCK] - Returns the completion status for
//                      the operation
//
//--------------------------------------------------------------------

NTSTATUS
DfsOpenDevice (
    IN PFILE_OBJECT FileObject,
    IN PDEVICE_OBJECT DeviceObject,
    IN ULONG CreateOptions
) {

    //
    //  Check to see which type of device is being opened.
    //  We don't permit all open modes on the file system
    //  device object.
    //

    ULONG CreateDisposition = (CreateOptions >> 24) & 0x000000ff;

    //
    //  Check for proper desired access and rights
    //

    if (CreateDisposition != FILE_OPEN
        && CreateDisposition != FILE_OPEN_IF ) {

        DebugTrace(0, Dbg,
            "DfsOpenDevice: Invalid CreateDisposition\n", 0);

        return( STATUS_ACCESS_DENIED );
    }

    //
    //  Check if we were to open a directory
    //

    if (CreateOptions & FILE_DIRECTORY_FILE) {

        DebugTrace(0, Dbg,
            "DfsOpenDevice: Cannot open device as a directory\n", 0);

        return( STATUS_NOT_A_DIRECTORY );

    }

    FileObject->FsContext = (PVOID) DFS_OPEN_CONTEXT;

    return( STATUS_SUCCESS );
}