Brad Fitzpatrick
2b1cfa7c4d
When a recording upload fails mid-session, the recording goroutine
cancels the session context. This triggers two concurrent paths:
exec.CommandContext kills the process (causing cmd.Wait to return),
and killProcessOnContextDone tries to write the termination message
via exitOnce.Do. If cmd.Wait returns first, the main goroutine's
exitOnce.Do(func(){}) steals the once, and the termination message
is never written to the client.
Fix by waiting for killProcessOnContextDone to finish writing the
termination message (via <-ss.exitHandled) before claiming exitOnce,
when the context is already done.
Also fix the fallback path when launchProcess itself fails due to
context cancellation: use SSHTerminationMessage() with the correct
"\r\n\r\n" framing instead of fmt.Fprintf with the internal error
string.
Deflakes TestSSHRecordingCancelsSessionsOnUploadFailure, which was
failing consistently at a low rate due to the exitOnce race. After
this fix, flakestress passes with 8,668 runs, 0 failures.
Fixes #7707 (again. hopefully for good.)
Change-Id: I5ab911c71574db8d3f9d979fb839f273be51ecf9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Tailscale
Private WireGuard® networks made easy
Overview
This repository contains the majority of Tailscale's open source code.
Notably, it includes the tailscaled daemon and
the tailscale CLI tool. The tailscaled daemon runs on Linux, Windows,
macOS, and to varying degrees
on FreeBSD and OpenBSD. The Tailscale iOS and Android apps use this repo's
code, but this repo doesn't contain the mobile GUI code.
Other Tailscale repos of note:
- the Android app is at https://github.com/tailscale/tailscale-android
- the Synology package is at https://github.com/tailscale/tailscale-synology
- the QNAP package is at https://github.com/tailscale/tailscale-qpkg
- the Chocolatey packaging is at https://github.com/tailscale/tailscale-chocolatey
For background on which parts of Tailscale are open source and why, see https://tailscale.com/opensource/.
Using
We serve packages for a variety of distros and platforms at https://pkgs.tailscale.com.
Other clients
The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers. The GUI wrappers on non-open source platforms are themselves not open source.
Building
We always require the latest Go release, currently Go 1.26. (While we build releases with our Go fork, its use is not required.)
go install tailscale.com/cmd/tailscale{,d}
If you're packaging Tailscale for distribution, use build_dist.sh
instead, to burn commit IDs and version info into the binaries:
./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled
If your distro has conventions that preclude the use of
build_dist.sh, please do the equivalent of what it does in your
distro's way, so that bug reports contain useful version information.
Bugs
Please file any issues about this code or the hosted service on the issue tracker.
Contributing
PRs welcome! But please file bugs. Commit messages should reference bugs.
We require Developer Certificate of
Origin
Signed-off-by lines in commits.
See commit-messages.md (or skim git log) for our commit message style.
About Us
Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:
- https://github.com/tailscale/tailscale/graphs/contributors
- https://github.com/tailscale/tailscale-android/graphs/contributors
Legal
WireGuard is a registered trademark of Jason A. Donenfeld.