Rust bindings

[chrishayen]

I'm rewriting my tailscale-based cluster from go to rust and would like to get this in if possible. It implements all of the major functions and contains the echo example. All of the tsnet crates on crates.io are outdated and broken.

Please take a look. Thank you thank you.

[review-ai-agent]

Pull Request Revisions

Revision	Description
r8	Rust Tailscale networking API refactored Updated Rust Tailscale networking library to use OwnedFd and BorrowedFd instead of raw file descriptors, improving type safety
r7	Added Rust bindings for Tailscale library Introduced a new Rust project in rust/tsnet with Cargo configuration, build script, and library implementation to create Rust bindings for the Tailscale network library, including GitHub Actions workflow and necessary configuration files
r6	Refactored GitHub Actions Rust workflow Added workflow name, simplified trigger, and corrected YAML indentation for Rust build job
r5	Fixed GitHub Actions workflow indentation Corrected indentation of the steps block in the Rust workflow YAML configuration
r4	Added GitHub Actions workflow for Rust Created a new GitHub Actions workflow to build Rust project in tsnet directory on push and pull requests
r3	Added error message retrieval function Introduced new function to retrieve last error message from Tailscale instance using a pre-allocated buffer
r2	Modify tailscale error message handling Replace specific error message retrieval with generic "Unknown error" string when error occurs
r1	Added Rust bindings for libtailscale Created a new Rust project in rust/tsnet with Cargo configuration, build script, and initial library implementation to provide Rust bindings for the Tailscale C library

---

☑️ AI review skipped after 5 revisions, comment with `/review` to review again

Help

React with emojis to give feedback on AI-generated reviews:

• 👍 means the feedback was helpful and actionable
• 👎 means the feedback was incorrect or unhelpful

💬 Replying to feedback with a comment helps us improve the system. Your input also contributes to shaping future interactions with the AI reviewer.

We'd love to hear from you—reach out anytime at [email protected].

[raggi]

I may not have time to review immediately today, but in principle this will be great to have so I hope to get back to the PR ASAP.

[chrishayen]

I may not have time to review immediately today, but in principle this will be great to have so I hope to get back to the PR ASAP.

Awesome. Thank you.

[chrishayen]

@raggi Poke  🙂

[chrishayen]

@raggi Hey, actually don't merge this. I'm leaking file descriptors using dial. Any hints you can give me about the internal implementation of file descriptors? I get an error setting non blocking on them so I'm guessing there's maybe something non-standard going on. Even when I close the file descriptors on the rust side, while looping and using dial, I'm still seeing a steady increase of open file descriptors in lsof for my process. I didn't see anything to explicitly close file descriptors in tailscale.h, but I think I may have seen one of the other libraries using tailscale_close(fd).

I'm going to start digging through tailscale code but maybe you can give me a hint when you get a chance. Thanks.

[chrishayen]

@raggi All good. I updated the code to use rust's OwnedFd and BorrowedFd instead of i32 for passing file descriptors. The leak ended up being something in the app I was importing the library with, so it wasn't 100% necessary, but it's cleaner.