927ad0aef4
CmdName previously opened the running executable and streamed through tens of MB searching for two 16-byte magic needles to find the Go module info blob embedded by the linker, allocating a 64 KiB buffer on every call. It was called at least twice during tailscaled startup (logpolicy.LogsDir and logpolicy.Options.init on Windows) and once more for tsweb's debug page title -- each call ~2.6 ms on a ~40 MB tailscaled binary, and ~74 KB of allocator churn per call. The same module info is exposed via runtime/debug.ReadBuildInfo, which reads an already-resident string maintained by the Go runtime -- no filesystem I/O. Use that, cached with sync.OnceValue so the lookup happens at most once per process. Benchmarks on Xeon 6975P-C (Linux amd64), against the version test binary: BenchmarkCmdName before: 540,094 ns/op 66,136 B/op 8 allocs/op BenchmarkCmdName after: 2.5 ns/op 0 B/op 0 allocs/op First-call (uncached) cost at tailscaled scale (71 deps in embedded build info): 160 mallocs, ~11.5 KiB allocated, sub-microsecond. That is smaller than the single 64 KiB scratch buffer the old code allocated per call, and is now paid exactly once per process. Stripped tailscaled binary size is unchanged: runtime/debug was already imported transitively (including by sibling code in this same package at version/version.go:121), so no new dependencies ship. The hand-rolled byte scanner, 64 KiB scratch buffer, rsc.io/goversion- derived magic constants, and the 32-second integration test that built tailscaled to re-parse it are removed. TestCmdNameNoAllocs asserts that, once primed, CmdName is 0 allocs per call, guarding against regressions that reintroduce per-call binary parsing. TestCmdNameFromBuildInfo verifies that CmdName is pulling from the embedded build info rather than falling back to the os.Executable basename.
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.