Windows driver to access (read-only) conserve archives

[WolverinDEV]

As the title suggests, it might be possible to create a Windows UMDF driver allowing to view the conserve archive in read only mode and access it's file contents.
Original comment: #195 (comment)

[WolverinDEV]

Originally I thought about a classical kernel driver adding support for a virtual file system in order to read conserve archives.
The requirement for a kernel driver would be a [no_std] core library which can be leveraged to read the conserve archive.

Even tough, I'm most familiar with these kind of drivers kernel drivers (w/o wdk) might not be the well suited.
Over the years Windows has developed many different ways to create file system drivers without the need to load any kernel mode drivers.

Using the UMDF (user mode driver framework) is not only quite more safe and stable it might be possible to use the Rust std library therefore dropping the need for [no_std]. However, I do not have any experience with file system drivers using the UMDF therefore it's open if it's feasibility.

I might run some experiments if it's possible to create a virtual file system driver using the UMDF framework.

[sourcefrog]

Just based on glancing at their docs, UMDF seems like an easier approach than trying to get the whole of Conserve running in kernel mode. It looks a lot like FUSE for Windows.

[WolverinDEV]

Yes that's quite what I figured as well.
UMDF has one great addition as well:
You can load dynamic loadable libraries therefore you can write the UMDF driver with C and call into Rust code as windows-drivers-rs does not seem to be somewhat near to be used in production.

[WolverinDEV]

Hey,
a few updates here:

Using a driver to create a virtual file system seems to be a too tedious task to accomplish.
But with Windows 10, Microsoft published their Projected FileSystem API.

Leveraging this API we could easily implement a read-only conserve archive explorer.
Over the last few days I've experimented with that API and came up with a library for easy implementation:
https://github.com/WolverinDEV/windows-projfs

Some features are still missing like notification handling but the fundamentals are ready.