btleplug VS Rust-for-Linux

In case someone is curious: https://github.com/deviceplug/btleplug/pull/279/files

Is something wrong with https://github.com/deviceplug/btleplug or you haven't found it? You could also use bindings to platform libraries like https://github.com/microsoft/windows-rs and https://github.com/rust-mobile/ndk if btleplug doesn't have something fundamental to you.

One of the worst/best parts of buttplug is that I ended up needed to maintain my own Bluetooth LE library: btleplug (https://github.com/deviceplug/btleplug).

Worst because working with bluetooth is always THE WORST, best because of the submissions and community that've grown around it.

There's 2 types of PRs to btleplug:

- People going "here's a PR but uh, why is the library named btleplWAIT WHAT"

- People going "here is a PR specifically to fix something in Buttplug thank you"

"In its dev branch"

I've always been annoyed at the cross-platform story for Bluetooth. GATT is one of my favorite protocols because it is so simple, but writing simple code against this simple protocol is _not_ portable:

iOS and macOS have CoreBluetooth, Linux has BlueZ, Windows has Windows.Devices.Bluetooth and Android has android.bluetooth.

I've seen a few projects trying to fix this, like https://github.com/deviceplug/btleplug, and I hope one of them becomes production ready.

But, that's an ongoing problem. In terms of "done", I think the next big milestone will be mobile app support. We work on mobile web browsers in a couple of different ways, but Buttplug still needs app support, both native and for things like cordova/react native/etc... The biggest issue there at the moment lies in our bluetooth library (btleplug, https://github.com/deviceplug/btleplug), because getting the FFI via JNI to android is going to suck (even though I can crib off Servo's WebBluetooth impl, which worked on Android).

Ctrl-F "rust"

https://rust-for-linux.com/ links to LWN articles at https://lwn.net/Kernel/Index/#Development_tools-Rust that suggest that only basic modules are yet possible with the rust support in Linux kernels 6.2 and 6.3.

Rust-for-linux links to the Android binder module though:

> Android Binder Driver: This project is an effort to rewrite Android's Binder kernel driver in Rust.

> Motivation: Binder is one of the most security and performance critical components of Android. Android isolates apps from each other and the system by assigning each app a unique user ID (UID). This is called "application sandboxing", and is a fundamental tenet of the Android Platform Security Model.

> The majority of inter-process communication (IPC) on Android goes through Binder. Thus, memory unsafety vulnerabilities are especially critical when they happen in the Binder driver

... "Rust in the Linux kernel" (2021) https://security.googleblog.com/2021/04/rust-in-linux-kernel... :

> [...] We also need designs that allow code in the two languages to interact with each other: we're particularly interested in safe, zero-cost abstractions that allow Rust code to use kernel functionality written in C, and how to implement functionality in idiomatic Rust that can be called seamlessly from the C portions of the kernel.

> Since Rust is a new language for the kernel, we also have the opportunity to enforce best practices in terms of documentation and uniformity. For example, we have specific machine-checked requirements around the usage of unsafe code: for every unsafe function, the developer must document the requirements that need to be satisfied by callers to ensure that its usage is safe; additionally, for every call to unsafe functions (or usage of unsafe constructs like dereferencing a raw pointer), the developer must document the justification for why it is safe to do so.

> We'll now show how such a driver would be implemented in Rust, contrasting it with a C implementation. [...]

This guide with unsafe rust that calls into the C, and then with next gen much safer rust right next to it would be a helpful resource too.

What of the post-docker container support (with userspaces also written in go) should be cloned to rust first?

Rust-for-Linux issue tracker

Also, there already exists both issue: https://github.com/Rust-for-Linux/linux/issues/479

Yes, I definitely agree that it's a problem that pr_info implicitly wraps its arguments in unsafe {}. I wrote my own Pull Request with a trival fix.

Note that this template won't work with Linux 6.1, which has very minimal Rust support. You'll want the RustForLinux tree, or maybe Linux 6.2.

> Also we’re bringing NPM style supply chain problems to the kernel now?

Nope. They've thought that through.

(In fact, cargo is only used to build test helpers. https://github.com/Rust-for-Linux/linux/blob/rust/Documentat...)

The alloc library is available if a global allocator is available. Rust for Linux implements a global allocator (or, more accurately, hooks into the kernel's existing allocator, in rust/kernel/allocator.rs), and therefore you can use the alloc library in the Linux kernel.

Here's the tracking issue for unstable features used.

There’s a Github repo for the Rust support and the maintainers actually accept pull requests and issues there. They’re quite responsive too and you’ll get excellent feedback on your submissions.