3ad551c325
Add TestRangeHook, a build-tagged (ts_rangehook) test that finds
accidentally-O(n) range loops in the netmap delta processing path.
It arms the runtime.DidRange hook, a Tailscale-only Go toolchain
modification that reports every range loop's potential and actual
iteration counts, while an in-process tsnet client (via the existing
largetailnet Streamer harness) processes a few hundred one-peer
add+remove deltas against an initial N-peer netmap. Any loop that
could iterate at least N/2 times is recorded with its call stack
into a custom pprof profile, so per-delta O(n) work shows up as a
stack with a sample count near the delta count.
The test requires the bradfitz/rangehook branch of
github.com/tailscale/go (as of 2026-07-11, based on upstream Go at
approximately 1.27rc1), which is why it is hidden behind the
ts_rangehook build tag; the stock toolchain has no runtime.DidRange
and cannot compile this file. See the file comment for the full
recipe.
Running it on main at 296f6c1f7 finds 16 unique per-delta O(n)
loops, all under LocalBackend.UpdateNetmapDelta ->
authReconfigLocked; on bradfitz/routeman2 that drops to 6.
Updates #12542
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: I49ccadbd4472abecc1450ca67bd93919f6b90201
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.