Mike O'Driscoll
48919f708b
Fix the following issues: 1. Endianness Bug: The nftables runner used hardcoded big-endian byte arrays for firewall mark values (0xff0000, etc.), breaking bitwise operations on little-endian systems (all x86/x64, ARM). This caused connmark save/restore rules to silently fail. Fixed by using binary.NativeEndian to generate correct byte order for the host system. 2. Connmark Restore Conditional Check: The connmark restore mechanism unconditionally overwrote packet marks, even when Tailscale hadn't set any mark bits in conntrack. This destroyed mark bits set by other systems (VPNs, policy routing, vendor flags), breaking coexistence. Fixed by adding a conditional check to only restore when (ct mark & 0xff0000) != 0, preventing the worst case of wiping all marks to zero. Changes: - util/linuxfw/linuxfw.go: Added nativeEndianUint32() helper and updated all mask functions to use native byte order instead of hardcoded bytes - util/linuxfw/nftables_runner.go: Added conditional check in makeConnmarkRestoreExprs() to only restore when ct mark has Tailscale bits set; added detailed comment about bit preservation limitations - util/linuxfw/iptables_runner.go: Added conditional check using -m connmark ! --mark to match nftables behavior - Tests updated: Fixed byte-level regression tests to expect little-endian byte sequences and verify the new conditional check Note: Perfect bit preservation in nftables remains challenging due to nftables expression VM limitations. The current implementation prevents the critical case of wiping marks with zero. Updates #3310 Fixes #11803 Related to #8555 Signed-off-by: Mike O'Driscoll <mikeo@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.