Commit Graph

9 Commits

Author SHA1 Message Date
Mike O'Driscoll
1403920367 derp,types,util: use bufio Peek+Discard for allocation-free fast reads (#19067)
Replace byte-at-a-time ReadByte loops with Peek+Discard in the DERP
read path. Peek returns a slice into bufio's internal buffer without
allocating, and Discard advances the read pointer without copying.

Introduce util/bufiox with a BufferedReader interface and ReadFull
helper that uses Peek+copy+Discard as an allocation-free alternative
to io.ReadFull.

  - derp.ReadFrameHeader: replace 5× ReadByte with Peek(5)+Discard(5),
    reading the frame type and length directly from the peeked slice.
    Remove now-unused readUint32 helper.

    name                  old ns/op  new ns/op  speedup
    ReadFrameHeader-8     24.2       12.4       ~2x
    (0 allocs/op in both)

  - key.NodePublic.ReadRawWithoutAllocating: replace 32× ReadByte with
    bufiox.ReadFull. Addresses the "Dear future" comment about switching
    away from byte-at-a-time reads once a non-escaping alternative exists.

    name                              old ns/op  new ns/op  speedup
    NodeReadRawWithoutAllocating-8    140        43.6       ~3.2x
    (0 allocs/op in both)

  - derpserver.handleFramePing: replace io.ReadFull with bufiox.ReadFull.

Updates tailscale/corp#38509

Signed-off-by: Mike O'Driscoll <mikeo@tailscale.com>
2026-03-24 10:52:20 -04:00
Brad Fitzpatrick
156d97c549 derp/derpserver: fix locking in a few expvar.Func metrics (#19031)
Fixes #19030
Fixes tailscale/corp#38782

Change-Id: I53082059d4012b9765b5596f7023717282132888

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2026-03-18 14:26:01 -04:00
Mike O'Driscoll
26ba71d23f derp: add envknob to disable RTT stats collection (#19029)
Updates tailscale/corp#38509

Signed-off-by: Mike O'Driscoll <mikeo@tailscale.com>
2026-03-18 13:04:18 -04:00
Brad Fitzpatrick
bd2a2d53d3 all: use Go 1.26 things, run most gofix modernizers
I omitted a lot of the min/max modernizers because they didn't
result in more clear code.

Some of it's older "for x := range 123".

Also: errors.AsType, any, fmt.Appendf, etc.

Updates #18682

Change-Id: I83a451577f33877f962766a5b65ce86f7696471c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2026-03-06 13:32:03 -08:00
Will Norris
3ec5be3f51 all: remove AUTHORS file and references to it
This file was never truly necessary and has never actually been used in
the history of Tailscale's open source releases.

A Brief History of AUTHORS files
---

The AUTHORS file was a pattern developed at Google, originally for
Chromium, then adopted by Go and a bunch of other projects. The problem
was that Chromium originally had a copyright line only recognizing
Google as the copyright holder. Because Google (and most open source
projects) do not require copyright assignemnt for contributions, each
contributor maintains their copyright. Some large corporate contributors
then tried to add their own name to the copyright line in the LICENSE
file or in file headers. This quickly becomes unwieldy, and puts a
tremendous burden on anyone building on top of Chromium, since the
license requires that they keep all copyright lines intact.

The compromise was to create an AUTHORS file that would list all of the
copyright holders. The LICENSE file and source file headers would then
include that list by reference, listing the copyright holder as "The
Chromium Authors".

This also become cumbersome to simply keep the file up to date with a
high rate of new contributors. Plus it's not always obvious who the
copyright holder is. Sometimes it is the individual making the
contribution, but many times it may be their employer. There is no way
for the proejct maintainer to know.

Eventually, Google changed their policy to no longer recommend trying to
keep the AUTHORS file up to date proactively, and instead to only add to
it when requested: https://opensource.google/docs/releasing/authors.
They are also clear that:

> Adding contributors to the AUTHORS file is entirely within the
> project's discretion and has no implications for copyright ownership.

It was primarily added to appease a small number of large contributors
that insisted that they be recognized as copyright holders (which was
entirely their right to do). But it's not truly necessary, and not even
the most accurate way of identifying contributors and/or copyright
holders.

In practice, we've never added anyone to our AUTHORS file. It only lists
Tailscale, so it's not really serving any purpose. It also causes
confusion because Tailscalars put the "Tailscale Inc & AUTHORS" header
in other open source repos which don't actually have an AUTHORS file, so
it's ambiguous what that means.

Instead, we just acknowledge that the contributors to Tailscale (whoever
they are) are copyright holders for their individual contributions. We
also have the benefit of using the DCO (developercertificate.org) which
provides some additional certification of their right to make the
contribution.

The source file changes were purely mechanical with:

    git ls-files | xargs sed -i -e 's/\(Tailscale Inc &\) AUTHORS/\1 contributors/g'

Updates #cleanup

Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d
Signed-off-by: Will Norris <will@tailscale.com>
2026-01-23 15:49:45 -08:00
James Tucker
5ee0c6bf1d derp/derpserver: add a unique sender cardinality estimate
Adds an observation point that may identify potentially abusive traffic
patterns at outlier values.

Updates tailscale/corp#24681

Signed-off-by: James Tucker <james@tailscale.com>
2025-11-26 12:23:35 -08:00
Brad Fitzpatrick
99b06eac49 syncs: add Mutex/RWMutex alias/wrappers for future mutex debugging
Updates #17852

Change-Id: I477340fb8e40686870e981ade11cd61597c34a20
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2025-11-16 19:13:59 -08:00
Simon Law
34242df51b derp/derpserver: clean up extraction of derp.Server (#17264)
PR #17258 extracted `derp.Server` into `derp/derpserver.Server`.

This followup patch adds the following cleanups:
1. Rename `derp_server*.go` files to `derpserver*.go` to match
   the package name.
2. Rename the `derpserver.NewServer` constructor to `derpserver.New`
   to reduce stuttering.
3. Remove the unnecessary `derpserver.Conn` type alias.

Updates #17257
Updates #cleanup

Signed-off-by: Simon Law <sfllaw@tailscale.com>
2025-09-24 10:38:30 -07:00
Brad Fitzpatrick
21dc5f4e21 derp/derpserver: split off derp.Server out of derp into its own package
This exports a number of things from the derp (generic + client) package
to be used by the new derpserver package, as now used by cmd/derper.

And then enough other misc changes to lock in that cmd/tailscaled can
be configured to not bring in tailscale.com/client/local. (The webclient
in particular, even when disabled, was bringing it in, so that's now fixed)

Fixes #17257

Change-Id: I88b6c7958643fb54f386dd900bddf73d2d4d96d5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2025-09-24 09:19:01 -07:00