James Tucker
3c0508fa28
Make link queue writes nonblocking: gVisor can generate replies on the reader needed to drain the queue. A full queue drops only the rejected packet and reports ErrNoBufferSpace, which gVisor counts and TCP handles by arming its retransmit timer. UDP sockets do not see the error unless IP_RECVERR is set, matching Linux. Count WireGuard-bound drops as reason="queue_full" in tailscaled_outbound_dropped_packets_total, and per-queue drops in debug and client metrics. Add Wrapper.TryInjectOutbound for best-effort replies generated while processing packets (TSMP rejects and pongs, conn25 rejects, fake-mode echo replies), so those paths drop instead of stalling behind the injection queue's reader. Its drops are also counted as queue_full. Make outbound injection waits cancellable and close link queues before abort-generated replies. Stop the WireGuard injection pump on ErrClosed. Release injected packets still queued at Close, outside closeOnce to allow reentrant release callbacks; a sender whose send races with Close releases the packet itself. Release temporary capture buffers. Copy injected payload views directly into the WireGuard slab, avoiding an intermediate allocation and copy. Test queue saturation, multiqueue progress, cancellation, concurrent shutdown, reference ownership, fragmented payloads, and GSO. Performance versus the parent commit, on a 4-core Xeon 6975P-C: inject+read 64B / 1280B 245ns / 479ns -> 187ns / 195ns, 0 allocs 4 injectors, 1 reader 843ns -> 451ns 64KiB GSO inject+split 10.9us -> 4.4us, 64KiB/op -> 0 link queue write+read 81.4ns -> 81.5ns tsnet TCP, 1 / 8 streams 448 / 580 MB/s -> 492 / 674 MB/s BenchmarkTCPQueueBottleneck shows that dropping on full queues keeps throughput at the bottleneck rate (117 MB/s at 100k packets/s, as with blocking writes), at the cost of more retransmits with many streams. Fixes #21631 Updates #21638 Updates #21632 Updates #21639 Signed-off-by: James Tucker <james@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 1.27. (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.