mmsd VS unsafe-code-guidelines

> MMS or Multimedia Messages are supported by gammu but they are stored in a binary format I have yet to find documentation on how to make something usable out of it for download. Any info in it is greatly appreciated.

You could look at this implementation: mmsd-tng [1]. It is used to handle MMSes on the PinePhone for instance.

[1] https://gitlab.com/kop316/mmsd/

I installed mmsd-tng from Chris Talbot's repo (I don't run Mobian unstable and didn't wanna go fetch the package from there), and installed Chatty from Purism's repo per the Mobian docs. To be sure of no conflicts, I carefully uninstalled the existing Chatty via dpkg -r --force-deps chatty to remove just Chatty without taking Phosh out with it.

Apparently MMS isn't used much outside of North America so it's not as high of a priority. I' on Mobian and use Janky MMS to at least receive them, but I still can't send them. There is also an MMS daemon that someone created to at least process them, but getting a messaging app to pick them up is still a challenge. They are also working on getting it integrated into Chatty. Apparently its getting pretty close but its kind of slow going because its mostly one guy working on it. So if you're any good with C (especially UI design) they are always open for more contributors.

To get it working, you basically need a fork of mmsd (i.e. mmsd-tng) and you need an app that can pull the MMS messages in. The same developer who has worked on mmsd (kop316) has spent a good amount of time updating Chatty/Chats with his own custom branch, though it is quite barebones and really only allows receiving MMS images as file:// links in the UX. It sounds like Purism will eventually get around to implementing this in the UX but it may not be for months.

Useful context on the Rust side is this issue [1]. It sounds like some of the author's concerns are addressed already.

[1]: https://github.com/rust-lang/unsafe-code-guidelines/issues/4...

Is this captured by one of the known soundness conflicts? If not then should consider adding it to the list.

There are some competing proposals for different memory models. Stacked borrows is the current proposal, but there are more work in the approproate WG.

Thank you /u/RalfJung for bringing formal methods to Rust, both through models like Stacked Borrows, by developing miri, and by working on unsafe-code-guidelines which aims to specify exactly what is and isn't allowed in unsafe code (surprisingly, it's an open question as 2023!)

You could imagine some way to make this safe for example automatically convert &'short &'long mut T to &'short &'short T, but it's non-trivial to prove they are safe at all, not to mention ensuring this is correctly implemented in the compiler. If you're interested there's also a discussion on whether the opposite (& & T to & &mut T) is sound here.

Agreed! MIRI is so good, it still feels like magic to me. It also comforts me that the Rust team takes improving unsafe semantics seriously, with the past Unsafe Code Guidelines WG and today's operational semantics team (t-opsem).

I think there are some aspects of this rule that are still undecided. See for example:

- https://github.com/rust-lang/unsafe-code-guidelines/issues/8...

- https://github.com/rust-lang/miri/issues/2732

C is much better specified than unsafe Rust. Some things are just not worked out yet in Rust. This may sometimes even bite very experienced devs, such as this issue with Box's aliasing semantics, which tripped up the author of left-right.