EldoS | Feel safer!

Software components for data protection, secure storage and transfer

Callback filesystem and Alternate Data streams

Also by EldoS: CallbackFilter
A component to monitor and control disk activity, track file and directory operations (create, read, write, rename etc.), alter file data, encrypt files, create virtual files.
#17218
Posted: 08/07/2011 22:05:06
by ray han (Basic support level)
Joined: 05/10/2011
Posts: 24

Hi All,
We are developing a remote filesystem using Callback filesystem (The data is being retrieved from a remote server and presented as a filesystem).

I have been successful in showing the folders and files but I notice that that I Am seeing lots of calls (and fails) due to the calls for /<path>/pipe or :Zone.Identifier. I see failures due to these as these files dont exist (for example I cant even open a PDF file)

Google searches indicate that these are related to Alternate Data Streams in NTFS. Is there any resource or sample that I can look at related to this or is there anyway I can prevent ADS?

Interestingly, the drive I have mounted shows as FAT32 and so it is odd that I am dealing with NTFS specific stuff. On a side note, I do have a "cache" in NTFS that I use to speed up access to the remote file.

I don't have lot of experience in windows specific programming (I have been working primarily in linux/AIX) so any pointers will be very helpful.

Regards
#17219
Posted: 08/08/2011 01:34:08
by Eugene Mayevski (EldoS Corp.)

Did you set an event handler for OnEnumerateNamedStreams? If yes, please remove it (completely, not just the code insight) and let us know the result.


Sincerely yours
Eugene Mayevski
#17223
Posted: 08/08/2011 07:24:32
by ray han (Basic support level)
Joined: 05/10/2011
Posts: 24

Hi Eugene,
I have no event handler installed for OnEnumerateNamedStreams.

Thanks
#17224
Posted: 08/08/2011 07:38:55
by Eugene Mayevski (EldoS Corp.)

Ok, and what about file system name? I assume that the samples work for you and your code does not, so we need to figure out, what is different between samples and your code.


Sincerely yours
Eugene Mayevski
#17225
Posted: 08/08/2011 07:54:37
by Volodymyr Zinin (EldoS Corp.)

Quote
ray han wrote:
I notice that that I Am seeing lots of calls (and fails) due to the calls for /<path>/pipe or :Zone.Identifier.

Where are you seeing it? Does it mean the OnOpen callback is called with such file names?

Also please specify what version of Windows (including if it's 32- or 64-bit) and type of CallbackFS (i.e. .NET, C++, or Delphi) you are using.
Thanks.
#17226
Posted: 08/08/2011 10:41:43
by ray han (Basic support level)
Joined: 05/10/2011
Posts: 24

Hi Vladimir,

I am using the C++ library.
The <xxxxx>/pipe call is coming to OnGetFileInfo callback when I try to open a pdf file
The <xxxxx>/Filename:Zone.Identifier come when I right click a file and click on Properties

Thanks
#17227
Posted: 08/08/2011 10:45:03
by ray han (Basic support level)
Joined: 05/10/2011
Posts: 24

Quote
Ok, and what about file system name? I assume that the samples work for you and your code does not, so we need to figure out, what is different between samples and your code.


I did try the Mounter sample and I could see that it is creating file and and it shows up fine. I didnt see any calls coming related to ADS.

Even in my setup, I can display files/folders, open text files, image files and modify and save them (Which gets coverted to a remote update op).

I read up on ADS and seems to be specific to NTFS and the drive itself shows up as FAT32 so I was surprised to see these callbacks (which fail because I dont have those files).
#17229
Posted: 08/08/2011 15:00:59
by Volodymyr Zinin (EldoS Corp.)

First check if your code contains the SetOnEnumerateNamedStreams call or not before the MountMedia call. If the call is present then remove it.

If it doesn't help please take Process Monitor from sysinternals.com, run it and reproduce the problem. Then save the log (in the native format, which is .pml or so) and give it to us.
Thanks.

Quote
ray han wrote:
I read up on ADS and seems to be specific to NTFS and the drive itself shows up as FAT32 so I was surprised to see these callbacks (which fail because I dont have those files).

I don't think that the file system name has any influence on this situation.
#17232
Posted: 08/08/2011 22:35:57
by ray han (Basic support level)
Joined: 05/10/2011
Posts: 24

Hi Vladimir,

I made sure that no callback handler was installed in SetOnEnumerateNamedStreams. I will try the Process Monitor stuff and get the trace.

Thanks
#17233
Posted: 08/08/2011 23:00:01
by ray han (Basic support level)
Joined: 05/10/2011
Posts: 24

Hi Vladimir,

Here is the processmonitor output.

This is a Win7 64bit box. I started process monitor and then reproduced the problem (by mounting the drive and accessing the files)

1. I tried opening 1010-MPEMS-DS-EN.pdf (This fails because I get calls for "pipe")
2. I right clicked and tried to display properties for file 7631472-lg.jpg (which opens fine etc) and it gets the calls for 7631472-lg.jpg:Zone.Identifier and the properties are all empty (though it shows everything in another view - When I click the file, the details are shown in the bottom panel of the window)

Let me know if this looks ok.

Thanks
Ray
Also by EldoS: CallbackDisk
Create virtual disks backed by memory or custom location, expose disk images as disks and more.

Reply

Statistics

Topic viewed 3785 times

Number of guests: 1, registered members: 0, in total hidden: 0




|

Back to top

As of July 15, 2016 EldoS Corporation will operate as a division of /n software inc. For more information, please read the announcement.

Got it!