Commit Graph

1488 Commits (978306565d0e9e9f1e5347969ddaeffe0f989cfe)

Author SHA1 Message Date
Jordan Whited 641693d61c
ipn/ipnlocal: install IPv6 service addr route (#13252)
This is the equivalent of quad-100, but for IPv6. This is technically
already contained in the Tailscale IPv6 ULA prefix, but that is only
installed when remote peers are visible via control with contained
addrs. The service addr should always be reachable.

Updates #1152

Signed-off-by: Jordan Whited <jordan@tailscale.com>
4 weeks ago
Brad Fitzpatrick e54c81d1d0 types/views: add Slice.All iterator
And convert a few callers as an example, but nowhere near all.

Updates #12912

Change-Id: I5eaa12a29a6cd03b58d6f1072bd27bc0467852f2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 weeks ago
Percy Wegmann 4637ac732e ipn/ipnlocal: remember last notified taildrive shares and only notify if they've changed
Fixes #13195

Signed-off-by: Percy Wegmann <percy@tailscale.com>
4 weeks ago
Anton Tolchanov 151b77f9d6 cmd/tl-longchain: tool to re-sign nodes with long rotation signatures
In Tailnet Lock, there is an implicit limit on the number of rotation
signatures that can be chained before the signature becomes too long.

This program helps tailnet admins to identify nodes that have signatures
with long chains and prints commands to re-sign those node keys with a
fresh direct signature. It's a temporary mitigation measure, and we will
remove this tool as we design and implement a long-term approach for
rotation signatures.

Example output:

```
2024/08/20 18:25:03 Self: does not need re-signing
2024/08/20 18:25:03 Visible peers with valid signatures:
2024/08/20 18:25:03 Peer xxx2.yy.ts.net. (100.77.192.34) nodeid=nyDmhiZiGA11KTM59, current signature kind=direct: does not need re-signing
2024/08/20 18:25:03 Peer xxx3.yy.ts.net. (100.84.248.22) nodeid=ndQ64mDnaB11KTM59, current signature kind=direct: does not need re-signing
2024/08/20 18:25:03 Peer xxx4.yy.ts.net. (100.85.253.53) nodeid=nmZfVygzkB21KTM59, current signature kind=rotation: chain length 4, printing command to re-sign
tailscale lock sign nodekey:530bddbfbe69e91fe15758a1d6ead5337aa6307e55ac92dafad3794f8b3fc661 tlpub:4bf07597336703395f2149dce88e7c50dd8694ab5bbde3d7c2a1c7b3e231a3c2
```

To support this, the NetworkLockStatus localapi response now includes
information about signatures of all peers rather than just the invalid
ones. This is not displayed by default in `tailscale lock status`, but
will be surfaced in `tailscale lock status --json`.

Updates #13185

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
1 month ago
Kristoffer Dalby 01aa01f310 ipn/ipnlocal: network-lock, error if no pubkey instead of panic
Updates tailscale/corp#20931

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
1 month ago
Andrea Gottardo 9d2b1820f1
ipnlocal: support setting authkey at login using syspolicy (#13061)
Updates tailscale/corp#22120

Adds the ability to start the backend by reading an authkey stored in the syspolicy database (MDM). This is useful for devices that are provisioned in an unattended fashion.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
1 month ago
Percy Wegmann 74b9fa1348 ipn/localapi: only flush relevant data in multiFilePostResponseWriter.Flush()
This prevents two things:

1. Crashing if there's no response body
2. Sending a nonsensical 0 response status code

Updates tailscale/corp#22357

Signed-off-by: Percy Wegmann <percy@tailscale.com>
1 month ago
Brad Fitzpatrick 4c2e978f1e cmd/tailscale/cli: support passing network lock keys via files
Fixes tailscale/corp#22356

Change-Id: I959efae716a22bcf582c20d261fb1b57bacf6dd9
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
1 month ago
Naman Sood f79183dac7
cmd/tsidp: add funnel support (#12591)
* cmd/tsidp: add funnel support

Updates #10263.

Signed-off-by: Naman Sood <mail@nsood.in>

* look past funnel-ingress-node to see who we're authenticating

Signed-off-by: Naman Sood <mail@nsood.in>

* fix comment typo

Signed-off-by: Naman Sood <mail@nsood.in>

* address review feedback, support Basic auth for /token

Turns out you need to support Basic auth if you do client ID/secret
according to OAuth.

Signed-off-by: Naman Sood <mail@nsood.in>

* fix typos

Signed-off-by: Naman Sood <mail@nsood.in>

* review fixes

Signed-off-by: Naman Sood <mail@nsood.in>

* remove debugging log

Signed-off-by: Naman Sood <mail@nsood.in>

* add comments, fix header

Signed-off-by: Naman Sood <mail@nsood.in>

---------

Signed-off-by: Naman Sood <mail@nsood.in>
1 month ago
Andrea Gottardo 949b15d858
net/captivedetection: call SetHealthy once connectivity restored (#12974)
Fixes tailscale/tailscale#12973
Updates tailscale/tailscale#1634

There was a logic issue in the captive detection code we shipped in https://github.com/tailscale/tailscale/pull/12707.

Assume a captive portal has been detected, and the user notified. Upon switching to another Wi-Fi that does *not* have a captive portal, we were issuing a signal to interrupt any pending captive detection attempt. However, we were not also setting the `captive-portal-detected` warnable to healthy. The result was that any "captive portal detected" alert would not be cleared from the UI.

Also fixes a broken log statement value.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2 months ago
Andrea Gottardo 90be06bd5b
health: introduce captive-portal-detected Warnable (#12707)
Updates tailscale/tailscale#1634

This PR introduces a new `captive-portal-detected` Warnable which is set to an unhealthy state whenever a captive portal is detected on the local network, preventing Tailscale from connecting.



ipn/ipnlocal: fix captive portal loop shutdown


Change-Id: I7cafdbce68463a16260091bcec1741501a070c95

net/captivedetection: fix mutex misuse

ipn/ipnlocal: ensure that we don't fail to start the timer


Change-Id: I3e43fb19264d793e8707c5031c0898e48e3e7465

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2 months ago
Irbe Krumina 57856fc0d5
ipn,wgengine/magicsock: allow setting static node endpoints via tailscaled configfile (#12882)
wgengine/magicsock,ipn: allow setting static node endpoints via tailscaled config file.

Adds a new StaticEndpoints field to tailscaled config
that can be used to statically configure the endpoints
that the node advertizes. This field will replace
TS_DEBUG_PRETENDPOINTS env var that can be used to achieve the same.

Additionally adds some functionality that ensures that endpoints
are updated when configfile is reloaded.

Also, refactor configuring/reconfiguring components to use the
same functionality when configfile is parsed the first time or
subsequent times (after reload). Previously a configfile reload
did not result in resetting of prefs. Now it does- but does not yet
tell the relevant components to consume the new prefs. This is to
be done in a follow-up.

Updates tailscale/tailscale#12578


Signed-off-by: Irbe Krumina <irbe@tailscale.com>
2 months ago
Andrew Lytvynov e7bf6e716b
cmd/tailscale: add --min-validity flag to the cert command (#12822)
Some users run "tailscale cert" in a cron job to renew their
certificates on disk. The time until the next cron job run may be long
enough for the old cert to expire with our default heristics.

Add a `--min-validity` flag which ensures that the returned cert is
valid for at least the provided duration (unless it's longer than the
cert lifetime set by Let's Encrypt).

Updates #8725

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
2 months ago
Adrian Dewhurst 54f58d1143 ipn/ipnlocal: add comment explaining auto exit node migration
Updates tailscale/corp#19681

Change-Id: I6d396780b058ff0fbea0e9e53100f04ef3b76339
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
2 months ago
Adrian Dewhurst 8882c6b730 ipn/ipnlocal: wait for DERP before auto exit node migration
Updates tailscale/corp#19681

Change-Id: I31dec154aa3b5edba01f10eec37640f631729cb2
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
2 months ago
Adrian Dewhurst 0834712c91 ipn: allow FQDN in exit node selection
To match the format of exit node suggestions and ensure that the result
is not ambiguous, relax exit node CLI selection to permit using a FQDN
including the trailing dot.

Updates #12618

Change-Id: I04b9b36d2743154aa42f2789149b2733f8555d3f
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
2 months ago
Anton Tolchanov 5d61d1c7b0 log/sockstatlog: don't block for more than 5s on shutdown
Fixes tailscale/corp#21618

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
2 months ago
Claire Wang 49bf63cdd0
ipn/ipnlocal: check for offline auto exit node in SetControlClientStatus (#12772)
Updates tailscale/corp#19681

Signed-off-by: Claire Wang <claire@tailscale.com>
2 months ago
Nick Khyl fc28c8e7f3 cmd/cloner, cmd/viewer, util/codegen: add support for generic types and interfaces
This adds support for generic types and interfaces to our cloner and viewer codegens.
It updates these packages to determine whether to make shallow or deep copies based
on the type parameter constraints. Additionally, if a template parameter or an interface
type has View() and Clone() methods, we'll use them for getters and the cloner of the
owning structure.

Updates #12736

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2 months ago
Anton Tolchanov 874972b683 posture: add network hardware addresses to posture identity
If an optional `hwaddrs` URL parameter is present, add network interface
hardware addresses to the posture identity response.

Just like with serial numbers, this requires client opt-in via MDM or
`tailscale set --posture-checking=true`
(https://tailscale.com/kb/1326/device-identity)

Updates tailscale/corp#21371

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
2 months ago
Brad Fitzpatrick c6af5bbfe8 all: add test for package comments, fix, add comments as needed
Updates #cleanup

Change-Id: Ic4304e909d2131a95a38b26911f49e7b1729aaef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2 months ago
Andrew Lytvynov 7b1c764088
ipn/ipnlocal: gate systemd-run flags on systemd version (#12747)
We added a workaround for --wait, but didn't confirm the other flags,
which were added in systemd 235 and 236. Check systemd version for
deciding when to set all 3 flags.

Fixes #12136

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
2 months ago
Andrew Lytvynov b8af91403d
clientupdate: return true for CanAutoUpdate for macsys (#12746)
While `clientupdate.Updater` won't be able to apply updates on macsys,
we use `clientupdate.CanAutoUpdate` to gate the EditPrefs endpoint in
localAPI. We should allow the GUI client to set AutoUpdate.Apply on
macsys for it to properly get reported to the control plane. This also
allows the tailnet-wide default for auto-updates to propagate to macsys
clients.

Updates https://github.com/tailscale/corp/issues/21339

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
2 months ago
Claire Wang 8965e87fa8
ipn/ipnlocal: handle auto value for ExitNodeID syspolicy (#12512)
Updates tailscale/corp#19681

Signed-off-by: Claire Wang <claire@tailscale.com>
3 months ago
Anton Tolchanov 781f79408d ipn/ipnlocal: allow multiple signature chains from the same SigCredential
Detection of duplicate Network Lock signature chains added in
01847e0123 failed to account for chains
originating with a SigCredential signature, which is used for wrapped
auth keys. This results in erroneous removal of signatures that
originate from the same re-usable auth key.

This change ensures that multiple nodes created by the same re-usable
auth key are not getting filtered out by the network lock.

Updates tailscale/corp#19764

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
3 months ago
Anton Tolchanov 4651827f20 tka: test SigCredential signatures and netmap filtering
This change moves handling of wrapped auth keys to the `tka` package and
adds a test covering auth key originating signatures (SigCredential) in
netmap.

Updates tailscale/corp#19764

Signed-off-by: Anton Tolchanov <anton@tailscale.com>
3 months ago
Adrian Dewhurst 8f7588900a ipn/ipnlocal: fix nil pointer dereference and add related test
Fixes #12644

Change-Id: I3589b01a9c671937192caaedbb1312fd906ca712
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
3 months ago
Andrew Lytvynov 2064dc20d4
health,ipn/ipnlocal: hide update warning when auto-updates are enabled (#12631)
When auto-udpates are enabled, we don't need to nag users to update
after a new release, before we release auto-updates.

Updates https://github.com/tailscale/corp/issues/20081

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
3 months ago
Josh McKinney 1d6ab9f9db cmd/serve: don't convert localhost to 127.0.0.1
This is not valid in many situations, specifically when running a local astro site that listens on localhost, but ignores 127.0.0.1

Fixes: https://github.com/tailscale/tailscale/issues/12201

Signed-off-by: Josh McKinney <joshka@users.noreply.github.com>
3 months ago
Andrew Dunham 0323dd01b2 ci: enable checklocks workflow for specific packages
This turns the checklocks workflow into a real check, and adds
annotations to a few basic packages as a starting point.

Updates #12625

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I2b0185bae05a843b5257980fc6bde732b1bdd93f
3 months ago
Naman Sood 75254178a0
ipn/ipnlocal: don't bind localListener if its context is canceled (#12621)
The context can get canceled during backoff, and binding after that
makes the listener impossible to close afterwards.

Fixes #12620.

Signed-off-by: Naman Sood <mail@nsood.in>
3 months ago
Andrew Dunham 30f8d8199a ipn/ipnlocal: fix data race in tests
We can observe a data race in tests when logging after a test is
finished. `b.onHealthChange` is called in a goroutine after being
registered with `health.Tracker.RegisterWatcher`, which calls callbacks
in `setUnhealthyLocked` in a new goroutine.

See: https://github.com/tailscale/tailscale/actions/runs/9672919302/job/26686038740

Updates #12054

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ibf22cc994965d88a9e7236544878d5373f91229e
3 months ago
Brad Fitzpatrick d5e692f7e7 ipn/ipnlocal: check operator user via osuser package
So non-local users (e.g. Kerberos on FreeIPA) on Linux can be looked
up. Our default binaries are built with pure Go os/user which only
supports the classic /etc/passwd and not any libc-hooked lookups.

Updates #12601

Change-Id: I9592db89e6ca58bf972f2dcee7a35fbf44608a4f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 months ago
Brad Fitzpatrick 5ec01bf3ce wgengine/filter: support FilterRules matching on srcIP node caps [capver 100]
See #12542 for background.

Updates #12542

Change-Id: Ida312f700affc00d17681dc7551ee9672eeb1789
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 months ago
Andrea Gottardo d6a8fb20e7
health: include DERP region name in bad derp notifications (#12530)
Fixes tailscale/corp#20971

We added some Warnables for DERP failure situations, but their Text currently spits out the DERP region ID ("10") in the UI, which is super ugly. It would be better to provide the RegionName of the DERP region that is failing. We can do so by storing a reference to the last-known DERP map in the health package whenever we fetch one, and using it when generating the notification text.

This way, the following message...

> Tailscale could not connect to the relay server '10'. The server might be temporarily unavailable, or your Internet connection might be down.

becomes:

> Tailscale could not connect to the 'Seattle' relay server. The server might be temporarily unavailable, or your Internet connection might be down.

which is a lot more user-friendly.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
3 months ago
Andrew Dunham 45d2f4301f proxymap, various: distinguish between different protocols
Previously, we were registering TCP and UDP connections in the same map,
which could result in erroneously removing a mapping if one of the two
connections completes while the other one is still active.

Add a "proto string" argument to these functions to avoid this.
Additionally, take the "proto" argument in LocalAPI, and plumb that
through from the CLI and add a new LocalClient method.

Updates tailscale/corp#20600

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I35d5efaefdfbf4721e315b8ca123f0c8af9125fb
3 months ago
Brad Fitzpatrick 86e0f9b912 net/ipset, wgengine/filter/filtertype: add split-out packages
This moves NewContainsIPFunc from tsaddr to new ipset package.

And wgengine/filter types gets split into wgengine/filter/filtertype,
so netmap (and thus the CLI, etc) doesn't need to bring in ipset,
bart, etc.

Then add a test making sure the CLI deps don't regress.

Updates #1278

Change-Id: Ia246d6d9502bbefbdeacc4aef1bed9c8b24f54d5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 months ago
Maisem Ali 491483d599 cmd/viewer,type/views: add MapSlice for maps of slices
This abstraction provides a nicer way to work with
maps of slices without having to write out three long type
params.

This also allows it to provide an AsMap implementation which
copies the map and the slices at least.

Updates tailscale/corp#20910

Signed-off-by: Maisem Ali <maisem@tailscale.com>
3 months ago
Andrea Gottardo a8ee83e2c5
health: begin work to use structured health warnings instead of strings, pipe changes into ipn.Notify (#12406)
Updates tailscale/tailscale#4136

This PR is the first round of work to move from encoding health warnings as strings and use structured data instead. The current health package revolves around the idea of Subsystems. Each subsystem can have (or not have) a Go error associated with it. The overall health of the backend is given by the concatenation of all these errors.

This PR polishes the concept of Warnable introduced by @bradfitz a few weeks ago. Each Warnable is a component of the backend (for instance, things like 'dns' or 'magicsock' are Warnables). Each Warnable has a unique identifying code. A Warnable is an entity we can warn the user about, by setting (or unsetting) a WarningState for it. Warnables have:

- an identifying Code, so that the GUI can track them as their WarningStates come and go
- a Title, which the GUIs can use to tell the user what component of the backend is broken
- a Text, which is a function that is called with a set of Args to generate a more detailed error message to explain the unhappy state

Additionally, this PR also begins to send Warnables and their WarningStates through LocalAPI to the clients, using ipn.Notify messages. An ipn.Notify is only issued when a warning is added or removed from the Tracker.

In a next PR, we'll get rid of subsystems entirely, and we'll start using structured warnings for all errors affecting the backend functionality.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
3 months ago
Brad Fitzpatrick 6908fb0de3 ipn/localapi,client/tailscale,cmd/derper: add WhoIs lookup by nodekey, use in derper
Fixes #12465

Change-Id: I9b7c87315a3d2b2ecae2b8db9e94b4f5a1eef74a
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 months ago
Irbe Krumina bc53ebd4a0
ipn/{ipnlocal,localapi},net/netkernelconf,client/tailscale,cmd/containerboot: optionally enable UDP GRO forwarding for containers (#12410)
Add a new TS_EXPERIMENTAL_ENABLE_FORWARDING_OPTIMIZATIONS env var
that can be set for tailscale/tailscale container running as
a subnet router or exit node to enable UDP GRO forwarding
for improved performance.
See https://tailscale.com/kb/1320/performance-best-practices#linux-optimizations-for-subnet-routers-and-exit-nodes
This is currently considered an experimental approach;
the configuration support is partially to allow further experimentation
with containerized environments to evaluate the performance
improvements.

Updates tailscale/tailscale#12295

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
3 months ago
Adrian Dewhurst 0219317372 ipn/ipnlocal: improve sticky last suggestion
The last suggested exit node needs to be incorporated in the decision
making process when a new suggestion is requested, but currently it is
not quite right: it'll be used if the suggestion code has an error or a
netmap is unavailable, but it won't be used otherwise.

Instead, this makes the last suggestion into a tiebreaker when making a
random selection between equally-good options. If the last suggestion
does not make it to the final selection pool, then a different
suggestion will be made.

Since LocalBackend.SuggestExitNode is back to being a thin shim that
sets up the parameters to suggestExitNode, it no longer needs a test.
Its test was unable to be comprehensive anyway as the code being tested
contains an uncontrolled random number generator.

Updates tailscale/corp#19681

Change-Id: I94ecc9a0d1b622de3df4ef90523f1d3e67b4bfba
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
4 months ago
Andrew Lytvynov 7a7e314096
ipn/ipnlocal,clientupdate: allow auto-updates in contaienrs (#12391)
We assume most containers are immutable and don't expect tailscale
running in them to auto-update. But there's no reason to prohibit it
outright.

Ignore the tailnet-wide default auto-update setting in containers, but
allow local users to turn on auto-updates via the CLI.

RELNOTE=Auto-updates are allowed in containers, but ignore the tailnet-wide default.

Fixes #12292

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
4 months ago
Andrew Dunham e88a5dbc92 various: fix lint warnings
Some lint warnings caught by running 'make lint' locally.

Updates #cleanup

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I1534ed6f2f5e1eb029658906f9d62607dad98ca3
4 months ago
Maisem Ali 4a8cb1d9f3 all: use math/rand/v2 more
Updates #11058

Signed-off-by: Maisem Ali <maisem@tailscale.com>
4 months ago
Andrew Lytvynov 347e3f3d9a
go.mod,ipn/ipnlocal: update the ACME fork (#12343)
Update our fork of golang.org/x/crypto to pick up a fix for ACME ARI:
3fde5e568a

Fixes #12278

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
4 months ago
Adrian Dewhurst cf9f507d47 ipn/ipnlocal: only build allowed suggested node list once
Rather than building a new suggested exit node set every time, compute
it once on first use. Currently, syspolicy ensures that values do not
change without a restart anyway.

Since the set is being constructed in a separate func now, the test code
that manipulates syspolicy can live there, and the TestSuggestExitNode
can now run in parallel with other tests because it does not have global
dependencies.

Updates tailscale/corp#19681

Change-Id: Ic4bb40ccc91b671f9e542bd5ba9c96f942081515
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
4 months ago
Andrew Lytvynov 379e2bf189
ipn/ipnlocal: stop offline auto-updates on shutdown (#12342)
Clean up the updater goroutine on shutdown, in addition to doing that on
backend state change. This fixes a goroutine leak on shutdown in tests.

Updates #cleanup
4 months ago
Andrew Lytvynov bc4c8b65c7
ipn/ipnlocal: periodically run auto-updates when "offline" (#12118)
When the client is disconnected from control for any reason (typically
just turned off), we should still attempt to update if auto-updates are
enabled. This may help users who turn tailscale on infrequently for
accessing resources.

RELNOTE: Apply auto-updates even if the node is down or disconnected
from the coordination server.

Updates #12117

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
4 months ago
Adrian Dewhurst 3bf2bddbb5 ipn/ipnlocal: improve testability of random node selection
In order to test the sticky last suggestion code, a test was written for
LocalBackend.SuggestExitNode but it contains a random number generator
which makes writing comprehensive tests very difficult. This doesn't
change how the last suggestion works, but it adds some infrastructure to
make that easier in a later PR.

This adds func parameters for the two randomized parts: breaking ties
between DERP regions and breaking ties between nodes. This way tests can
validate the entire list of tied options, rather than expecting a
particular outcome given a particular random seed.

As a result of this, the global random number generator can be used
rather than seeding a local one each time.

In order to see the tied nodes for the location based (i.e. Mullvad)
case, pickWeighted needed to return a slice instead of a single
arbitrary option, so there is a small change in how that works.

Updates tailscale/corp#19681

Change-Id: I83c48a752abdec0f59c58ccfd8bfb3f3f17d0ea8
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
4 months ago