linux: add a few kTLS defintions

[gennyble]

related: nix-rust/nix#2065

i think android has support, too, but if I put it in linux-like does that imply emscripten support?

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @JohnTitor (or someone else) soon.

Please see the contribution instructions for more information. Namely, in order to ensure the minimum review times lag, PR authors and assigned reviewers should ensure that the review label (S-waiting-on-review and S-waiting-on-author) stays updated, invoking these commands when appropriate:

• @rustbot author: the review is finished, PR author should check the comments and take action accordingly
• @rustbot review: the author is ready for a review, this PR will be queued again in the reviewer's queue

[fasterthanlime]

Thanks @gennyble for opening this!

I need this PR + a point release to (ultimately) land nix-rust/nix#2065 which in turn unblocks doing in-kernel TLS properly from rust with tokio, cf. rustls/ktls#26

(I know, exciting!)

[gennyble]

TLS_GET_RECORD_TYPE is from a kernel header which might not be available where libc is built. What would you like me to do here?

I see a skip might be an option?

[fasterthanlime]

@JohnTitor would it be possible to get a look at this? Maybe from another maintainer, if you're not able to?

[JohnTitor]

TLS_GET_RECORD_TYPE is from a kernel header which might not be available where libc is built. What would you like me to do here?

I see a skip might be an option?

Correct.

[gennyble]

Instead of skipping I added the header to the linux kernel headers for libc-test.

@rustbot review

[JohnTitor]

Cool, thanks! @bors r+

[bors]

📌 Commit 94cfcd2 has been approved by JohnTitor

It is now in the queue for this repository.

[bors]

⌛ Testing commit 94cfcd2 with merge af676d1...

[bors]

☀️ Test successful - checks-actions, checks-cirrus-freebsd-12, checks-cirrus-freebsd-13, checks-cirrus-freebsd-14
Approved by: JohnTitor
Pushing af676d1 to main...

[fasterthanlime]

Thanks for getting this merged! When can we expect this to be included in a crates.io release of libc ? (So we can bump the version nix relies on)

[fasterthanlime]

@JohnTitor the latest libc release was cut on June 25, 2023 - I think this means this PR still isn't on crates.io? The problem is we're trying to use those new additions from https://lib.rs/crates/nix, so a git dependency isn't really an option here.

Edit: opened #3350 to track this

Edit 2: @joshtriplett released 0.2.148 just now.