Avery Pennarun effbe67fe3 wgengine/magicsock: remove pickPort, use port 0 to avoid TOCTOU race
pickPort would bind a UDP socket on :0 to get a free port, close
the socket, then hope to rebind to the same port in NewConn. This
is a TOCTOU race that can cause flaky test failures when another
process grabs the port in between.

Instead, pass Port: 0 to NewConn and let the OS assign the port
atomically, then read back the assigned port via conn.LocalPort().

Fixes #19409

Change-Id: Ie44b599fb93c361e29a05f2171ad747c46f82b7a
Co-authored-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
2026-04-14 18:08:47 -07:00
2026-04-13 12:47:58 -07:00
2026-03-27 08:41:33 +00:00
2026-01-27 16:15:17 -08:00
2026-04-13 21:10:57 -07:00
2026-04-13 21:10:57 -07:00
2026-04-13 21:10:57 -07:00
2026-04-13 21:10:57 -07:00
2026-04-13 21:10:57 -07:00

Tailscale

https://tailscale.com

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:

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:

WireGuard is a registered trademark of Jason A. Donenfeld.

Description
The easiest, most secure way to use WireGuard and 2FA.
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