The previous LocalBackend & CLI 'up' changes improved some stuff, but
might've been too aggressive in some edge cases.
This simplifies the authURL vs authURLSticky distinction and removes
the interact field, which seemed to just just be about duplicate URL
suppression in IPN bus, back from when the IPN bus was a single client
at a time. This moves that suppression to a different spot.
Fixes#12119
Updates #12028
Updates #12042
Change-Id: I1f8800b1e82ccc1c8a0d7abba559e7404ddf41e4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The CLI's "up" is kinda chaotic and LocalBackend.Start is kinda
chaotic and they both need to be redone/deleted (respectively), but
this fixes some buggy behavior meanwhile. We were previously calling
StartLoginInteractive (to start the controlclient's RegisterRequest)
redundantly in some cases, causing test flakes depending on timing and
up's weird state machine.
We only need to call StartLoginInteractive in the client if Start itself
doesn't. But Start doesn't tell us that. So cheat a bit and a put the
information about whether there's a current NodeKey in the ipn.Status.
It used to be accessible over LocalAPI via GetPrefs as a private key but
we removed that for security. But a bool is fine.
So then only call StartLoginInteractive if that bool is false and don't
do it in the WatchIPNBus loop.
Fixes#12028
Updates #12042
Change-Id: I0923c3f704a9d6afd825a858eb9a63ca7c1df294
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
There was a small window in ipnserver after we assigned a LocalBackend
to the ipnserver's atomic but before we Start'ed it where our
initalization Start could conflict with API calls from the LocalAPI.
Simplify that a bit and lay out the rules in the docs.
Updates #12028
Change-Id: Ic5f5e4861e26340599184e20e308e709edec68b1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I found this too hard to read before.
This is pulled out of #12033 as it's unrelated cleanup in retrospect.
Updates #12028
Change-Id: I727c47e573217e3d1973c5b66a76748139cf79ee
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The CLI "up" command is a historical mess, both on the CLI side and
the LocalBackend side. We're getting closer to cleaning it up, but in
the meantime it was again implicated in flaky tests.
In this case, the background goroutine running WatchIPNBus was very
occasionally running enough to get to its StartLoginInteractive call
before the original goroutine did its Start call. That meant
integration tests were very rarely but sometimes logging in with the
default control plane URL out on the internet
(controlplane.tailscale.com) instead of the localhost control server
for tests.
This also might've affected new Headscale etc users on initial "up".
Fixes#11960Fixes#11962
Change-Id: I36f8817b69267a99271b5ee78cb7dbf0fcc0bd34
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I noticed this while working on the following fix to #11962.
Updates #11962
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: I4c5894d8899d1ae8c42f54ecfd4d05a4a7ac598c
set.Of(1, 2, 3) is prettier than set.SetOf([]int{1, 2, 3}).
I was going to change the signature of SetOf but then I noticed its
name has stutter anyway, so I kept it for compatibility. People can
prefer to use set.Of for new code or slowly migrate.
Also add a lazy Make method, which I often find myself wanting,
without having to resort to uglier mak.Set(&set, k, struct{}{}).
Updates #cleanup
Change-Id: Ic6f3870115334efcbd65e79c437de2ad3edb7625
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
While debugging a failing test in airplane mode on macOS, I noticed
netcheck logspam about ICMP socket creation permission denied errors.
Apparently macOS just can't do those, or at least not in airplane
mode. Not worth spamming about.
Updates #cleanup
Change-Id: I302620cfd3c8eabb25202d7eef040c01bd8a843c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The netcheck client, when no UDP is available, probes distance using
HTTPS.
Several problems:
* It probes using /derp/latency-check.
* But cmd/derper serves the handler at /derp/probe
* Despite the difference, it work by accident until c8f4dfc8c0
which made netcheck's probe require a 2xx status code.
* in tests, we only use derphttp.Handler, so the cmd/derper-installed
mux routes aren't preesnt, so there's no probe. That breaks
tests in airplane mode. netcheck.Client then reports "unexpected
HTTP status 426" (Upgrade Required)
This makes derp handle both /derp/probe and /derp/latency-check
equivalently, and in both cmd/derper and derphttp.Handler standalone
modes.
I notice this when wgengine/magicsock TestActiveDiscovery was failing
in airplane mode (no wifi). It still doesn't pass, but it gets
further.
Fixes#11989
Change-Id: I45213d4bd137e0f29aac8bd4a9ac92091065113f
Not buying wifi on a short flight is a good way to find tests
that require network. Whoops.
Updates #cleanup
Change-Id: Ibe678e9c755d27269ad7206413ffe9971f07d298
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In prep for it being required in more places.
Updates #11874
Change-Id: Ib743205fc2a6c6ff3d2c4ed3a2b28cac79156539
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In prep for making health warnings rich objects with metadata rather
than a bunch of strings, start moving it all into the same place.
We'll still ultimately need the stringified form for the CLI and
LocalAPI for compatibility but we'll next convert all these warnings
into Warnables that have severity levels and such, and legacy
stringification will just be something each Warnable thing can do.
Updates #4136
Change-Id: I83e189435daae3664135ed53c98627c66e9e53da
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We had this in a different repo, but moving it here, as this a more
fitting package.
Updates #cleanup
Change-Id: I5fb9b10e465932aeef5841c67deba4d77d473d57
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In prep for most of the package funcs in net/interfaces to become
methods in a long-lived netmon.Monitor that can cache things. (Many
of the funcs are very heavy to call regularly, whereas the long-lived
netmon.Monitor can subscribe to things from the OS and remember
answers to questions it's asked regularly later)
Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299
Change-Id: Ie4e8dedb70136af2d611b990b865a822cd1797e5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
... in prep for merging the net/interfaces package into net/netmon.
This is a no-op change that updates a bunch of the API signatures ahead of
a future change to actually move things (and remove the type alias)
Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299
Change-Id: I477613388f09389214db0d77ccf24a65bff2199c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The goal is to move more network state accessors to netmon.Monitor
where they can be cheaper/cached. But first (this change and others)
we need to make sure the one netmon.Monitor is plumbed everywhere.
Some notable bits:
* tsdial.NewDialer is added, taking a now-required netmon
* because a tsdial.Dialer always has a netmon, anything taking both
a Dialer and a NetMon is now redundant; take only the Dialer and
get the NetMon from that if/when needed.
* netmon.NewStatic is added, primarily for tests
Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299
Change-Id: I877f9cb87618c4eb037cee098241d18da9c01691
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This has been a TODO for ages. Time to do it.
The goal is to move more network state accessors to netmon.Monitor
where they can be cheaper/cached.
Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299
Change-Id: I60fc6508cd2d8d079260bda371fc08b6318bcaf1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I'm working on moving all network state queries to be on
netmon.Monitor, removing old APIs.
Updates tailscale/corp#10910
Updates tailscale/corp#18960
Updates #7967
Updates #3299
Change-Id: If0de137e0e2e145520f69e258597fb89cf39a2a3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This adds a health.Tracker to tsd.System, accessible via
a new tsd.System.HealthTracker method.
In the future, that new method will return a tsd.System-specific
HealthTracker, so multiple tsnet.Servers in the same process are
isolated. For now, though, it just always returns the temporary
health.Global value. That permits incremental plumbing over a number
of changes. When the second to last health.Global reference is gone,
then the tsd.System.HealthTracker implementation can return a private
Tracker.
The primary plumbing this does is adding it to LocalBackend and its
dozen and change health calls. A few misc other callers are also
plumbed. Subsequent changes will flesh out other parts of the tree
(magicsock, controlclient, etc).
Updates #11874
Updates #4136
Change-Id: Id51e73cfc8a39110425b6dc19d18b3975eac75ce
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In prep for tsd.System Tracker plumbing throughout tailscaled,
defensively permit all methods on Tracker to accept a nil receiver
without crashing, lest I screw something up later. (A health tracking
system that itself causes crashes would be no good.) Methods on nil
receivers should not be called, so a future change will also collect
their stacks (and panic during dev/test), but we should at least not
crash in prod.
This also locks that in with a test using reflect to automatically
call all methods on a nil receiver and check they don't crash.
Updates #11874
Updates #4136
Change-Id: I8e955046ebf370ec8af0c1fb63e5123e6282a9d3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Previously it was both metadata about the class of warnable item as
well as the value.
Now it's only metadata and the value is per-Tracker.
Updates #11874
Updates #4136
Change-Id: Ia1ed1b6c95d34bc5aae36cffdb04279e6ba77015
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This moves most of the health package global variables to a new
`health.Tracker` type.
But then rather than plumbing the Tracker in tsd.System everywhere,
this only goes halfway and makes one new global Tracker
(`health.Global`) that all the existing callers now use.
A future change will eliminate that global.
Updates #11874
Updates #4136
Change-Id: I6ee27e0b2e35f68cb38fecdb3b2dc4c3f2e09d68
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It was only obviously unused after the previous change, c39cde79d.
Updates #19334
Change-Id: I9896d5fa692cb4346c070b4a339d0d12340c18f7
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We were storing server-side lots of:
"Auth":{"Provider":"","LoginName":"","Oauth2Token":null,"AuthKey":""},
That was about 7% of our total storage of pending RegisterRequest
bodies.
Updates tailscale/corp#19327
Change-Id: Ib73842759a2b303ff5fe4c052a76baea0d68ae7d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Most of the magicsock tests fake the network, simulating packets going
out and coming in. There's no reason to actually hit your router to do
UPnP/NAT-PMP/PCP during in tests. But while debugging thousands of
iterations of tests to deflake some things, I saw it slamming my
router. This stops that.
Updates #11762
Change-Id: I59b9f48f8f5aff1fa16b4935753d786342e87744
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This removes AWS and Kubernetes support from Linux binaries by default
on GOARCH values where people don't typically run on AWS or use
Kubernetes, such as 32-bit mips CPUs.
It primarily focuses on optimizing for the static binaries we
distribute. But for people building it themselves, they can set
ts_kube or ts_aws (the opposite of ts_omit_kube or ts_omit_aws) to
force it back on.
Makes tailscaled binary ~2.3MB (~7%) smaller.
Updates #7272, #10627 etc
Change-Id: I42a8775119ce006fa321462cb2d28bc985d1c146
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It should've been deleted in 11ece02f52.
Updates #9040
Change-Id: If8a136bdb6c82804af658c9d2b0a8c63ce02d509
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Seems to deflake tstest/integration tests. I can't reproduce it
anymore on one of my VMs that was consistently flaking after a dozen
runs before. Now I can run hundreds of times.
Updates #11649Fixes#7036
Change-Id: I2f7d4ae97500d507bdd78af9e92cd1242e8e44b8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We haven't needed this hack for quite some time Andrea says.
Updates #11649
Change-Id: Ie854b7edd0a01e92495669daa466c7c0d57e7438
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I'm on a mission to simplify LocalBackend.Start and its locking
and deflake some tests.
I noticed this hasn't been used since March 2023 when it was removed
from the Windows client in corp 66be796d33c.
So, delete.
Updates #11649
Change-Id: I40f2cb75fb3f43baf23558007655f65a8ec5e1b2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Trying to run iptables/nftables on Synology pauses for minutes with
lots of errors and ultimately does nothing as it's not used and we
lack permissions.
This fixes a regression from db760d0bac (#11601) that landed
between Synology testing on unstable 1.63.110 and 1.64.0 being cut.
Fixes#11737
Change-Id: Iaf9563363b8e45319a9b6fe94c8d5ffaecc9ccef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It was broken with the move to dist in 32e0ba5e68 which doesn't accept
amd64 anymore.
Updates #cleanup
Change-Id: Iaaaba2d73c6a09a226934fe8e5c18b16731ee7a6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We have tstest/integration nowadays.
And this test was one of the lone holdouts using the to-be-nuked
SetControlClientGetterForTesting.
Updates #11649
Change-Id: Icf8a6a2e9b8ae1ac534754afa898c00dc0b7623b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
cc vs ccAuto is a mess. It needs to go. But this is a baby step towards
getting there.
Updates #11649
Change-Id: I34f33934844e580bd823a7d8f2b945cf26c87b3b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The new Android app and its libtailscale don't use this anymore;
it uses LocalAPI like other clients now.
Updates #11649
Change-Id: Ic9f42b41e0e0280b82294329093dc6c275f41d50
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
At least in userspace-networking mode.
Fixes#11361
Change-Id: I78d33f0f7e05fe9e9ee95b97c99b593f8fe498f2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The derphttp.Client mutex is held during connects (for up to 10
seconds) so this LocalAddr method (blocking on said mutex) could also
block for up to 10 seconds, causing a pileup upstream in
magicsock/wgengine and ultimately a watchdog timeout resulting in a
crash.
Updates #11519
Change-Id: Idd1d94ee00966be1b901f6899d8b9492f18add0f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
After:
bradfitz@book1pro tailscale.com % ./tool/go test -c ./cmd/tailscale/cli
bradfitz@book1pro tailscale.com % ./cli.test
bradfitz@book1pro tailscale.com %
Before:
bradfitz@book1pro tailscale.com % ./tool/go test -c ./cmd/tailscale/cli
bradfitz@book1pro tailscale.com % ./cli.test
Warning: funnel=on for foo.test.ts.net:443, but no serve config
run: `tailscale serve --help` to see how to configure handlers
Warning: funnel=on for foo.test.ts.net:443, but no serve config
run: `tailscale serve --help` to see how to configure handlers
USAGE
funnel <serve-port> {on|off}
funnel status [--json]
Funnel allows you to publish a 'tailscale serve'
server publicly, open to the entire internet.
Turning off Funnel only turns off serving to the internet.
It does not affect serving to your tailnet.
SUBCOMMANDS
status show current serve/funnel status
error: path must be absolute
error: invalid TCP source "localhost:5432": missing port in address
error: invalid TCP source "tcp://somehost:5432"
must be one of: localhost or 127.0.0.1
tcp://somehost:5432error: invalid TCP source "tcp://somehost:0"
must be one of: localhost or 127.0.0.1
tcp://somehost:0error: invalid TCP source "tcp://somehost:65536"
must be one of: localhost or 127.0.0.1
tcp://somehost:65536error: path must be absolute
error: cannot serve web; already serving TCP
You don't have permission to enable this feature.
This also moves the color handling up to a generic spot so it's
not just one subcommand doing it itself. See
https://github.com/tailscale/tailscale/issues/11626#issuecomment-2041795129Fixes#11643
Updates #11626
Change-Id: I3a49e659dcbce491f4a2cb784be20bab53f72303
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
At least in the case of dialing a Tailscale IP.
Updates #4529
Change-Id: I9fd667d088a14aec4a56e23aabc2b1ffddafa3fe
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is primarily for GUIs, so they don't need to remember the most
recently used exit node themselves.
This adds some CLI commands, but they're disabled and behind the WIP
envknob, as we need to consider naming (on/off is ambiguous with
running an exit node, etc) as well as automatic exit node selection in
the future. For now the CLI commands are effectively developer debug
things to test the LocalAPI.
Updates tailscale/corp#18724
Change-Id: I9a32b00e3ffbf5b29bfdcad996a4296b5e37be7e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This names the func() that Once-unlocked LocalBackend.mu. It does so
both for docs and because it can then have a method: Unlock, for the
few points that need to explicitly unlock early (the cause of all this
mess). This makes those ugly points easy to find, and also can then
make them stricter, panicking if the mutex is already unlocked. So a
normal call to the func just once-releases the mutex, returning false
if it's already done, but the Unlock method is the strict one.
Then this uses it more, so most the b.mu.Unlock calls remaining are
simple cases and usually defers.
Updates #11649
Change-Id: Ia070db66c54a55e59d2f76fdc26316abf0dd4627
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
A number of methods in LocalBackend (with suffixed "LockedOnEntry")
require b.mu be held but unlock it on the way out. That's asymmetric
and atypical and error prone.
This adds a helper method to LocalBackend that locks the mutex and
returns a sync.OnceFunc that unlocks the mutex. Then we pass around
that unlocker func down the chain to make it explicit (and somewhat
type check the passing of ownership) but also let the caller defer
unlock it, in the case of errors/panics that happen before the callee
gets around to calling the unlock.
This revealed a latent bug in LocalBackend.DeleteProfile which double
unlocked the mutex.
Updates #11649
Change-Id: I002f77567973bd77b8906bfa4ec9a2049b89836a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
The output was changing randomly per run, due to range over a map.
Then some misc style tweaks I noticed while debugging.
Fixes#11629
Change-Id: I67aef0e68566994e5744d4828002f6eb70810ee1
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And make NewMultiLabelMap panic earlier (at construction time)
if the comparable struct type T violates the documented rules,
rather than panicking at Add time.
Updates #cleanup
Change-Id: Ib1a03babdd501b8d699c4f18b1097a56c916c6d5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Some of our labels contain UTF-8 and get mojibaked in the browser
right now.
Updates tailscale/corp#18687
Change-Id: I6069cffd6cc8813df415f06bb308bc2fc3ab65c4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This CONNECT client doesn't match what Go's net/http.Transport does
(making the two values match). This makes it match.
This is all pretty unspecified but most clients & doc examples show
these matching. And some proxy implementations (such as Zscaler) care.
Updates tailscale/corp#18716
Change-Id: I135c5facbbcec9276faa772facbde1bb0feb2d26
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Rather than pass around a scratch buffer, put it on the Logger.
This is a baby step towards removing the background uploading
goroutine and starting it as needed.
Updates tailscale/corp#18514 (insofar as it led me to look at this code)
Change-Id: I6fd94581c28bde40fdb9fca788eb9590bcedae1b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
First we had Capabilities []string. Then
https://tailscale.com/blog/acl-grants (#4217) brought CapMap, a
superset of Capabilities. Except we never really finished the
transition inside the codebase to go all-in on CapMap. This does so.
Notably, this coverts Capabilities on the wire early to CapMap
internally so the code can only deal in CapMap, even against an old
control server.
In the process, this removes PeerChange.Capabilities support, which no
known control plane sent anyway. They can and should use
PeerChange.CapMap instead.
Updates #11508
Updates #4217
Change-Id: I872074e226b873f9a578d9603897b831d50b25d9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
From a problem we hit with how badger registers expvars; it broke
trunkd's exported metrics.
Updates tailscale/corp#1297
Change-Id: I42e1552e25f734c6f521b6e993d57a82849464b2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
When node attributes were super rare, the O(n) slice scans looking for
node attributes was more acceptable. But now more code and more users
are using increasingly more node attributes. Time to make it a map.
Noticed while working on tailscale/corp#17879
Updates #cleanup
Change-Id: Ic17c80341f418421002fbceb47490729048756d2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
In the recent 20e9f3369 we made HealthChangeRequest machine requests
include a NodeKey, as it was the oddball machine request that didn't
include one. Unfortunately, that code was sometimes being called (at
least in some of our integration tests) without a node key due to its
registration with health.RegisterWatcher(direct.ReportHealthChange).
Fortunately tests in corp caught this before we cut a release. It's
possible this only affects this particular integration test's
environment, but still worth fixing.
Updates tailscale/corp#1297
Change-Id: I84046779955105763dc1be5121c69fec3c138672
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
To force the problem in its worst case scenario before fixing it.
Updates tailscale/corp#17859
Change-Id: I2c8b8e5f15c7801e1ab093feeafac52ec175a763
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This was just added in 69f4b459 which doesn't yet use it. This still
doesn't yet use it. It just pushes it down deeper into magicsock where
it'll used later.
Updates #7617
Change-Id: If2f8fd380af150ffc763489e1ff4f8ca2899fac6
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We used a HandleSet before when we didn't have a unique handle. But a
sessionID is a unique handle, so use that instead. Then that replaces
the other map we had.
And now we'll have a way to look up an IPN session by sessionID for
later.
Updates tailscale/corp#17859
Change-Id: I5f647f367563ec8783c643e49f93817b341d9064
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This adds a method to wgengine.Engine and plumbed down into magicsock
to add a way to get a type-safe Tailscale-safe wrapper around a
wireguard-go device.Peer that only exposes methods that are safe for
Tailscale to use internally.
It also removes HandshakeAttempts from PeerStatusLite that was just
added as it wasn't needed yet and is now accessible ala cart as needed
from the Peer type accessor.
None of this is used yet.
Updates #7617
Change-Id: I07be0c4e6679883e6eeddf8dbed7394c9e79c5f4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>