50b8cfbde2
The maxInFlightConnectionAttemptsForTest and maxInFlightConnectionAttemptsPerClientForTest globals were plain ints read by background gVisor TCP handler goroutines (via wrapTCPProtocolHandler) and written by tstest.Replace cleanup in TestTCPForwardLimits_PerClient. When a gVisor goroutine outlived the test cleanup window, the race detector caught the unsynchronized access. The race-prone code was introduced inc5abbcd4b4(2024-02-26, "wgengine/netstack: add a per-client limit for in-flight TCP forwards") which added both the plain int globals and the TestTCPForwardLimits_PerClient test that writes them via tstest.Replace. It is not obvious why this has only recently started being detected as a data race; likely some combination of gVisor version bumps, Go toolchain scheduler changes, and additional TCP-injecting subtests (e.g.03461ea7f, 2026-01-30) increased goroutine churn enough to hit the window. Change both globals to atomic.Int32 and replace tstest.Replace (which does non-atomic *target = old on cleanup) with explicit Store/Cleanup pairs. Fixes #19118 Change-Id: Id26ba6fbfb2e4ade319976db80af8e16c7c8778e 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.