Consolidate the duplicated WebSocket frame-parsing logic from Read
and Write into a shared processFrames loop, fixing several bugs in
the process:
- Mixed control and data frames in a single Read/Write call buffer
were not handled: a control frame would cause merged data frames
to be skipped.
- Multiple data frames into one Write call weren't being correctly
parsed: only the first frame was processed, ignoring the rest in
the buffer.
- msg.isFinalized was being set before confirming the fragment was
complete, so an incomplete msg fragment, could've been sometimes
marked as finalized.
- Continuation frames without any payload were being treated as if
they didn't have stream ID, even thought the id is already known
from the initial fragment.
Fixestailscale/corp#39583
Signed-off-by: Fernando Serboncini <fserb@tailscale.com>
Signed-off-by: chaosinthecrd <tom@tmlabs.co.uk>
Co-authored-by: chaosinthecrd <tom@tmlabs.co.uk>
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>
When kubectl starts an interactive attach session, it sends 2 resize
messages in quick succession. It seems that particularly in HTTP mode,
we often receive both of these WebSocket frames from the underlying
connection in a single read. However, our parser currently assumes 0-1
frames per read, and leaves the second frame in the read buffer until
the next read from the underlying connection. It doesn't take long after
that before we end up failing to skip a control message as we normally
should, and then we parse a control message as though it will have a
stream ID (part of the Kubernetes protocol) and error out.
Instead, we should keep parsing frames from the read buffer for as long
as we're able to parse complete frames, so this commit refactors the
messages parsing logic into a loop based on the contents of the read
buffer being non-empty.
k/k staging/src/k8s.io/kubectl/pkg/cmd/attach/attach.go for full
details of the resize messages.
There are at least a couple more multiple-frame read edge cases we
should handle, but this commit is very conservatively fixing a single
observed issue to make it a low-risk candidate for cherry picking.
Updates #13358
Change-Id: Iafb91ad1cbeed9c5231a1525d4563164fc1f002f
Signed-off-by: Tom Proctor <tomhjp@users.noreply.github.com>
cmd/k8s-operator,k8s-operator/sessionrecording: support recording WebSocket sessions
Kubernetes currently supports two streaming protocols, SPDY and WebSockets.
WebSockets are replacing SPDY, see
https://github.com/kubernetes/enhancements/issues/4006.
We were currently only supporting SPDY, erroring out if session
was not SPDY and relying on the kube's built-in SPDY fallback.
This PR:
- adds support for parsing contents of 'kubectl exec' sessions streamed
over WebSockets
- adds logic to distinguish 'kubectl exec' requests for a SPDY/WebSockets
sessions and call the relevant handler
Updates tailscale/corp#19821
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
Co-authored-by: Tom Proctor <tomhjp@users.noreply.github.com>
Fernando Serboncini
Will Norris
Tom Proctor
Irbe Krumina