Getting DOS name in minifilter

NTFSD
1

Hi all,

Suppose I want to convert a file path to DOS path.
For the file itself, it’s easily achieved using
IoQueryFileDosDeviceName(), since I have the FILE_OBJECT at hand.
However, in the case of RENAME, I only have the destination name in
FILE_RENAME_INFORMATION.
Which way would you advise to proceed?

Thanks in advance,
Greg.

2

I would try FltGetDestinationFileNameInformation, then
FltParseFileNameInformation and then IoVolumeDeviceToDosName on the original
FileObject->DeviceObject since rename doesn’t work across volumes. Then
simply concatenate the DOS name with the destination file name after the
volume (which is where FltParseFileNameInformation helps).

Thanks,
Alex.

3

In addition to what Alex says, remember that not every file can have a dos
device name. I’d also be very very careful about symbolic links.

“Greg” wrote in message news:xxxxx@ntfsd…
> Hi all,
>
> Suppose I want to convert a file path to DOS path.
> For the file itself, it’s easily achieved using
> IoQueryFileDosDeviceName(), since I have the FILE_OBJECT at hand.
> However, in the case of RENAME, I only have the destination name in
> FILE_RENAME_INFORMATION.
> Which way would you advise to proceed?
>
> Thanks in advance,
> Greg.
>

4

Thanks a lot, Alex.

Greg

On Wed, Oct 13, 2010 at 5:32 PM, Alex Carp wrote:
> I would try FltGetDestinationFileNameInformation, then
> FltParseFileNameInformation and then IoVolumeDeviceToDosName on the original
> FileObject->DeviceObject since rename doesn’t work across volumes. Then
> simply concatenate the DOS name with the destination file name after the
> volume (which is where FltParseFileNameInformation helps).
>
> Thanks,
> Alex.
>
>
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5

Thanks Rod.

Greg

On Thu, Oct 14, 2010 at 10:46 AM, Rod Widdowson
wrote:
> In addition to what Alex says, remember that not every file can have a dos
> device name. ?I’d also be very very careful about symbolic links.
>
>
> “Greg” wrote in message news:xxxxx@ntfsd…
>>
>> Hi all,
>>
>> Suppose I want to convert a file path to DOS path.
>> For the file itself, it’s easily achieved using
>> IoQueryFileDosDeviceName(), since I have the FILE_OBJECT at hand.
>> However, in the case of RENAME, I only have the destination name in
>> FILE_RENAME_INFORMATION.
>> Which way would you advise to proceed?
>>
>> Thanks in advance,
>> Greg.
>>
>
>
> —
> NTFSD is sponsored by OSR
>
> For our schedule of debugging and file system seminars
> (including our new fs mini-filter seminar) visit:
> http://www.osr.com/seminars
>
> To unsubscribe, visit the List Server section of OSR Online at
> http://www.osronline.com/page.cfm?name=ListServer
>