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IRP_MJ_DIRECTORY_CONTROL return a new _FILE_BOTH_DIR_INFORMATION?
I'm trying to intercept calls to FindFirstFile/ZwQueryDirectoryFile from a specific application from Minifilter. The goal is for the application to see a folder that doesn't exist. So if the app enumerates files and folders from an empty folder C:\Temp, that application shouldn't see that the folder is empty, instead it should see a folder in that directory (that I will provide in output result).
For this, I have defined a post operation callback for IRP_MJ_DIRECTORY_CONTROL and from there I return one more _FILE_BOTH_DIR_INFORMATION containing data about my "virtual" directory. All's good, I can see the directory from cmd.exe and explorer, but the problem is that the name is corrupted and after banging my head on it for 2 days, can't seem to find the solution.
I added the code Here for ease of readability.
When I load my minifilter, as I said, I can see my virtual directory, but instead of "helloWorld", it gets truncated to "oWorld" in explorer. In cmd, last char (d) gets truncated only. See attached screenshot.
Any idea what am I doing wrong?
Thanks
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Comments
Your arithmetic is probably wrong.
Hey Dejan. Can you elaborate more pls?
What Mr. Maksimovic is saying, I suspect, is that IRP_MN_QUERY_DIRECTORY has LOTS of "File Information Classes"... of which FileBothInformation is but one. You have to handle all the types of directory queries that you get, NOT just queries "FileBothInformation"
Peter
Peter Viscarola
OSR
@OSRDrivers
To add to the previous replies, best place to start is the FastFat sample and see which information classes it supports:
https://github.com/microsoft/Windows-driver-samples/blob/master/filesys/fastfat/dirctrl.c#L699
There are more but you'll at least be compatible with FAT to start.
NOTE: This code suuuuucks to write. It's just painful no matter how you slice it.
-scott
OSR
Oh I see, thank you so much guys, will research it