Add a new vet analyzer that checks t.Run subtest names don't contain
characters requiring quoting when re-running via "go test -run". This
enforces the style guide rule: don't use spaces or punctuation in
subtest names.
The analyzer flags:
- Direct t.Run calls with string literal names containing spaces,
regex metacharacters, quotes, or other problematic characters
- Table-driven t.Run(tt.name, ...) calls where tt ranges over a
slice/map literal with bad name field values
Also fix all 978 existing violations across 81 test files, replacing
spaces with hyphens and shortening long sentence-like names to concise
hyphenated forms.
Updates #19242
Change-Id: Ib0ad96a111bd8e764582d1d4902fe2599454ab65
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Use bufio.Writer.AvailableBuffer to write the frame header directly
into bufio's internal buffer as a single append+Write, avoiding 5
separate WriteByte calls. Fall back to the existing writeUint32
byte-at-a-time path when the buffer has insufficient space.
```
name old ns/op new ns/op speedup
WriteFrameHeader-8 18.8 7.8 ~2.4x
(0 allocs/op in both)
```
Add TestWriteFrameHeader with correctness
checks, allocation assertions, and coverage of both fast and slow
write paths. Move BenchmarkReadFrameHeader from client_test.go to
derp_test.go alongside BenchmarkWriteFrameHeader, co-located with
the functions under test.
Updates tailscale/corp#38509
Signed-off-by: Mike O'Driscoll <mikeo@tailscale.com>
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>
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>
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>
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>
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>
Add mesh key support to derpprobe for
probing derpers with verify set to true.
Move MeshKey checking to central point for code reuse.
Fix a bad error fmt msg.
Fixestailscale/corp#27294Fixestailscale/corp#25756
Signed-off-by: Mike O'Driscoll <mikeo@tailscale.com>
To authenticate mesh keys, the DERP servers used a simple == comparison,
which is susceptible to a side channel timing attack.
By extracting the mesh key for a DERP server, an attacker could DoS it
by forcing disconnects using derp.Client.ClosePeer. They could also
enumerate the public Wireguard keys, IP addresses and ports for nodes
connected to that DERP server.
DERP servers configured without mesh keys deny all such requests.
This patch also extracts the mesh key logic into key.DERPMesh, to
prevent this from happening again.
Security bulletin: https://tailscale.com/security-bulletins#ts-2025-003Fixestailscale/corp#28720
Signed-off-by: Simon Law <sfllaw@tailscale.com>
This fixes the implementation and test from #15208 which apparently
never worked.
Ignore the metacert when counting the number of expected certs
presented.
And fix the test, pulling out the TLSConfig setup code into something
shared between the real cmd/derper and the test.
Fixes#15579
Change-Id: I90526e38e59f89b480629b415f00587b107de10a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Use envknob to configure the per client send
queue depth for the derp server.
Fixestailscale/corp#24978
Signed-off-by: Mike O'Driscoll <mikeo@tailscale.com>
73280595a8 for #2751 added a "clientSet" interface to
distinguish the two cases of a client being singly connected (the
common case) vs tolerating multiple connections from the client at
once. At the time (three years ago) it was kinda an experiment
and we didn't know whether it'd stop the reconnect floods we saw
from certain clients. It did.
So this promotes it to a be first-class thing a bit, removing the
interface. The old tests from 73280595a were invaluable in ensuring
correctness while writing this change (they failed a bunch).
But the real motivation for this change is that it'll permit a future
optimization to add flow tracking for stats & performance where we
don't contend on Server.mu for each packet sent via DERP. Instead,
each client can track its active flows and hold on to a *clientSet and
ask the clientSet per packet what the active client is via one atomic
load rather than a mutex. And if the atomic load returns nil, we'll
know we need to ask the server to see if they died and reconnected and
got a new clientSet. But that's all coming later.
Updates #3560
Change-Id: I9ccda3e5381226563b5ec171ceeacf5c210e1faf
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
* wgengine/magicsock: add envknob to send CallMeMaybe to non-existent peer
For testing older client version responses to the PeerGone packet format change.
Updates #4326
Signed-off-by: Val <valerie@tailscale.com>
* derp: remove dead sclient struct member replaceLimiter
Leftover from an previous solution to the duplicate client problem.
Updates #2751
Signed-off-by: Val <valerie@tailscale.com>
* derp, derp/derphttp, wgengine/magicsock: add new PeerGone message type Not Here
Extend the PeerGone message type by adding a reason byte. Send a
PeerGone "Not Here" message when an endpoint sends a disco message to
a peer that this server has no record of.
Fixes#4326
Signed-off-by: Val <valerie@tailscale.com>
---------
Signed-off-by: Val <valerie@tailscale.com>
This allows tracking packet flow via logs for prober clients. Note that
the new sclient.debug() function is called on every received packet, but
will do nothing for most clients.
I have adjusted sclient logging to print public keys in short format
rather than full. This takes effect even for existing non-debug logging
(mostly client disconnect messages).
Example logs for a packet being sent from client [SbsJn] (connected to
derper [dM2E3]) to client [10WOo] (connected to derper [AVxvv]):
```
derper [dM2E3]:
derp client 10.0.0.1:35470[SbsJn]: register single client mesh("10.0.1.1"): 4 peers
derp client 10.0.0.1:35470[SbsJn]: read frame type 4 len 40 err <nil>
derp client 10.0.0.1:35470[SbsJn]: SendPacket for [10WOo], forwarding via <derphttp_client.Client [AVxvv] url=https://10.0.1.1/derp>: <nil>
derp client 10.0.0.1:35470[SbsJn]: read frame type 0 len 0 err EOF
derp client 10.0.0.1:35470[SbsJn]: read EOF
derp client 10.0.0.1:35470[SbsJn]: sender failed: context canceled
derp client 10.0.0.1:35470[SbsJn]: removing connection
derper [AVxvv]:
derp client 10.0.1.1:50650[10WOo]: register single client
derp client 10.0.1.1:50650[10WOo]: received forwarded packet from [SbsJn] via [dM2E3]
derp client 10.0.1.1:50650[10WOo]: sendPkt attempt 0 enqueued
derp client 10.0.1.1:50650[10WOo]: sendPacket from [SbsJn]: <nil>
derp client 10.0.1.1:50650[10WOo]: read frame type 0 len 0 err EOF
derp client 10.0.1.1:50650[10WOo]: read EOF
derp client 10.0.1.1:50650[10WOo]: sender failed: context canceled
derp client 10.0.1.1:50650[10WOo]: removing connection
```
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
Updates #7123
Updates #6257 (more to do in other repos)
Change-Id: I073e2a6d81a5d7fbecc29caddb7e057ff65239d0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
Instead of iterating over the map to determine the preferred forwarder
on every packet (which could happen concurrently with map mutations),
store it separately in an atomic variable.
Fixes#6445
Signed-off-by: Anton Tolchanov <anton@tailscale.com>
The io/ioutil package has been deprecated as of Go 1.16 [1]. This commit
replaces the existing io/ioutil functions with their new definitions in
io and os packages.
Reference: https://golang.org/doc/go1.16#ioutil
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
In prep for a future change to have client ping derp connections
when their state is questionable, rather than aggressively tearing
them down and doing a heavy reconnect when their state is unknown.
We already support ping/pong in the other direction (servers probing
clients) so we already had the two frame types, but I'd never finished
this direction.
Updates #3619
Change-Id: I024b815d9db1bc57c20f82f80f95fb55fc9e2fcc
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
On about 1 out of 500 runs, TestSendFreeze failed:
derp_test.go:416: bob: unexpected message type derp.PeerGoneMessage
Closing alice before bob created a race.
If bob closed promptly, the test passed.
If bob closed slowly, and alice's disappearance caused
bob to receive a PeerGoneMessage before closing, the test failed.
Deflake the test by closing bob first.
With this fix, the test passed 12,000 times locally.
Fixes#2668
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
A public key should only have max one connection to a given
DERP node (or really: one connection to a node in a region).
But if people clone their machine keys (e.g. clone their VM, Raspbery
Pi SD card, etc), then we can get into a situation where a public key
is connected multiple times.
Originally, the DERP server handled this by just kicking out a prior
connections whenever a new one came. But this led to reconnect fights
where 2+ nodes were in hard loops trying to reconnect and kicking out
their peer.
Then a909d37a59 tried to add rate
limiting to how often that dup-kicking can happen, but empirically it
just doesn't work and ~leaks a bunch of goroutines and TCP
connections, tying them up for hour+ while more and more accumulate
and waste memory. Mostly because we were doing a time.Sleep forever
while not reading from their TCP connections.
Instead, just accept multiple connections per public key but track
which is the most recent. And if two both are writing back & forth,
then optionally disable them both. That last part is only enabled in
tests for now. The current default policy is just last-sender-wins
while we gather the next round of stats.
Updates #2751
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
If a peer is connected to multiple nodes in a region (so
multiForwarder is in use) and then a node restarts and re-sends all
its additions, this bug about whether an element is in the
multiForwarder could cause a one-time flip in the which peer node we
forward to. Note a huge deal, but not written as intended.
Thanks to @lewgun for the bug report in #2141.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This adds a handler on the DERP server for logging bytes send and received by clients of the
server, by holding open a connection and recording if there is a difference between the number
of bytes sent and received. It sends a JSON marshalled object if there is an increase in the
number of bytes.
Signed-off-by: julianknodt <julianknodt@gmail.com>
No server support yet, but we want Tailscale 1.6 clients to be able to respond
to them when the server can do it.
Updates #1310
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
* advertise server's DERP public key following its ServerHello
* have client look for that DEPR public key in the response
PeerCertificates
* let client advertise it's going into a "fast start" mode
if it finds it
* modify server to support that fast start mode, just not
sending the HTTP response header
Cuts down another round trip, bringing the latency of being able to
write our first DERP frame from SF to Bangalore from ~725ms
(3 RTT) to ~481ms (2 RTT: TCP and TLS).
Fixes#693
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It just has a version number in it and it's not really needed.
Instead just return it as a normal Recv message type for those
that care (currently only tests).
Updates #150 (in that it shares the same goal: initial DERP latency)
Updates #199 (in that it removes some DERP versioning)
These aren't particularly performance critical,
but since I have an optimization pending for them,
it's worth having a corresponding benchmark.
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
This benchmark is far from perfect: It mixes together
client and server. Still, it provides a starting point
for easy profiling.
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
The magicsock derpReader was holding onto 65KB for each DERP
connection forever, just in case.
Make the derp{,http}.Client be in charge of memory instead. It can
reuse its bufio.Reader buffer space.
(The NewMeshClient constructor I added recently was gross in
retrospect at call sites, especially when it wasn't obvious that a
meshKey empty string meant a regular client)
Brad Fitzpatrick
Mike O'Driscoll
Will Norris
Simon Law
Claire Wang
valscale
Anton Tolchanov
Maisem Ali
Josh Soref
Eng Zer Jun
Charlotte Brandhorst-Satzkorn
Josh Bleecher Snyder
David Anderson
julianknodt
Josh Bleecher Snyder