Investigating battery costs on a busy tailnet I noticed a large number
of nodes regularly reconnecting to control and DERP. In one case I was
able to analyze closely `pmset` reported the every-minute wake-ups being
triggered by bluetooth. The node was by side effect reconnecting to
control constantly, and this was at times visible to peers as well.
Three changes here improve the situation:
- Short time jumps (less than 10 minutes) no longer produce "major
network change" events, and so do not trigger full rebind/reconnect.
- Many "incidental" fields on interfaces are ignored, like MTU, flags
and so on - if the route is still good, the rest should be manageable.
- Additional log output will provide more detail about the cause of
major network change events.
Updates #3363
Signed-off-by: James Tucker <james@tailscale.com>
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>
fixestailscale/tailscale#18418
Both Serve and PeerAPI broke when we moved the TailscaleInterfaceName
into State, which is updated asynchronously and may not be
available when we configure the listeners.
This extracts the explicit interface name property from netmon.State
and adds as a static struct with getters that have proper error
handling.
The bug is only found in sandboxed Darwin clients, where we
need to know the Tailscale interface details in order to set up the
listeners correctly (they must bind to our interface explicitly to escape
the network sandboxing that is applied by NECP).
Currently set only sandboxed macOS and Plan9 set this but it will
also be useful on Windows to simplify interface filtering in netns.
Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
updates tailscale/corp#33891
Addresses several older the TODO's in netmon. This removes the
Major flag precomputes the ChangeDelta state, rather than making
consumers of ChangeDeltas sort that out themselves. We're also seeing
a lot of ChangeDelta's being flagged as "Major" when they are
not interesting, triggering rebinds in wgengine that are not needed. This
cleans that up and adds a host of additional tests.
The dependencies are cleaned, notably removing dependency on netmon
itself for calculating what is interesting, and what is not. This includes letting
individual platforms set a bespoke global "IsInterestingInterface"
function. This is only used on Darwin.
RebindRequired now roughly follows how "Major" was historically
calculated but includes some additional checks for various
uninteresting events such as changes in interface addresses that
shouldn't trigger a rebind. This significantly reduces thrashing (by
roughly half on Darwin clients which switching between nics). The individual
values that we roll into RebindRequired are also exposed so that
components consuming netmap.ChangeDelta can ask more
targeted questions.
Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
The callback itself is not removed as it is used in other repos, making
it simpler for those to slowly transition to the eventbus.
Updates #15160
Signed-off-by: Claus Lensbøl <claus@tailscale.com>
Remove the need for the caller to hold on to and call an unregister
function. Both two callers (one real, one test) already have a context
they can use. Use context.AfterFunc instead. There are no observable
side effects from scheduling too late if the goroutine doesn't run sync.
Updates #17148
Change-Id: Ie697dae0e797494fa8ef27fbafa193bfe5ceb307
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This adds a new helper to the netmon package that allows us to
rate-limit log messages, so that they only print once per (major)
LinkChange event. We then use this when constructing the portmapper, so
that we don't keep spamming logs forever on the same network.
Updates #13145
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I6e7162509148abea674f96efd76be9dffb373ae4
