Commit Graph

229 Commits (0d76d7d21c951872433de708839025c8dfb304b3)

Author SHA1 Message Date
Nick Khyl 874db2173b ipn/{ipnauth,ipnlocal,ipnserver}: send the auth URL to the user who started interactive login
We add the ClientID() method to the ipnauth.Actor interface and updated ipnserver.actor to implement it.
This method returns a unique ID of the connected client if the actor represents one. It helps link a series
of interactions initiated by the client, such as when a notification needs to be sent back to a specific session,
rather than all active sessions, in response to a certain request.

We also add LocalBackend.WatchNotificationsAs and LocalBackend.StartLoginInteractiveAs methods,
which are like WatchNotifications and StartLoginInteractive but accept an additional parameter
specifying an ipnauth.Actor who initiates the operation. We store these actor identities in
watchSession.owner and LocalBackend.authActor, respectively,and implement LocalBackend.sendTo
and related helper methods to enable sending notifications to watchSessions associated with actors
(or, more broadly, identifiable recipients).

We then use the above to change who receives the BrowseToURL notifications:
 - For user-initiated, interactive logins, the notification is delivered only to the user who initiated the
   process. If the initiating actor represents a specific connected client, the URL notification is sent back
   to the same LocalAPI client that called StartLoginInteractive. Otherwise, the notification is sent to all
   clients connected as that user.
   Currently, we only differentiate between users on Windows, as it is inherently a multi-user OS.
 - In all other cases (e.g., node key expiration), we send the notification to all connected users.

Updates tailscale/corp#18342

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2 weeks ago
Brad Fitzpatrick 2531065d10 clientupdate, ipn/localapi: don't use google/uuid, thin iOS deps
We were using google/uuid in two places and that brought in database/sql/driver.

We didn't need it in either place.

Updates #13760
Updates tailscale/corp#20099

Change-Id: Ieed32f1bebe35d35f47ec5a2a429268f24f11f1f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 weeks ago
Kristoffer Dalby 0e0e53d3b3 util/usermetrics: make usermetrics non-global
this commit changes usermetrics to be non-global, this is a building
block for correct metrics if a go process runs multiple tsnets or
in tests.

Updates #13420
Updates tailscale/corp#22075

Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
1 month ago
Andrea Gottardo 8a6f48b455
cli: add `tailscale dns query` (#13368)
Updates tailscale/tailscale#13326

Adds a CLI subcommand to perform DNS queries using the internal DNS forwarder and observe its internals (namely, which upstream resolvers are being used).

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
1 month ago
Andrea Gottardo d060b3fa02
cli: implement `tailscale dns status` (#13353)
Updates tailscale/tailscale#13326

This PR begins implementing a `tailscale dns` command group in the Tailscale CLI. It provides an initial implementation of `tailscale dns status` which dumps the state of the internal DNS forwarder.

Two new endpoints were added in LocalAPI to support the CLI functionality:

- `/netmap`: dumps a copy of the last received network map (because the CLI shouldn't have to listen to the ipn bus for a copy)
- `/dns-osconfig`: dumps the OS DNS configuration (this will be very handy for the UI clients as well, as they currently do not display this information)

My plan is to implement other subcommands mentioned in tailscale/tailscale#13326, such as `query`, in later PRs.

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
2 months ago
Nick Khyl 961ee321e8 ipn/{ipnauth,ipnlocal,ipnserver,localapi}: start baby step toward moving access checks from the localapi.Handler to the LocalBackend
Currently, we use PermitRead/PermitWrite/PermitCert permission flags to determine which operations are allowed for a LocalAPI client.
These checks are performed when localapi.Handler handles a request. Additionally, certain operations (e.g., changing the serve config)
requires the connected user to be a local admin. This approach is inherently racey and is subject to TOCTOU issues.
We consider it to be more critical on Windows environments, which are inherently multi-user, and therefore we prevent more than one
OS user from connecting and utilizing the LocalBackend at the same time. However, the same type of issues is also applicable to other
platforms when switching between profiles that have different OperatorUser values in ipn.Prefs.

We'd like to allow more than one Windows user to connect, but limit what they can see and do based on their access rights on the device
(e.g., an local admin or not) and to the currently active LoginProfile (e.g., owner/operator or not), while preventing TOCTOU issues on Windows
and other platforms. Therefore, we'd like to pass an actor from the LocalAPI to the LocalBackend to represent the user performing the operation.
The LocalBackend, or the profileManager down the line, will then check the actor's access rights to perform a given operation on the device
and against the current (and/or the target) profile.

This PR does not change the current permission model in any way, but it introduces the concept of an actor and includes some preparatory
work to pass it around. Temporarily, the ipnauth.Actor interface has methods like IsLocalSystem and IsLocalAdmin, which are only relevant
to the current permission model. It also lacks methods that will actually be used in the new model. We'll be adding these gradually in the next
PRs and removing the deprecated methods and the Permit* flags at the end of the transition.

Updates tailscale/corp#18342

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2 months ago
Kristoffer Dalby a2c42d3cd4 usermetric: add initial user-facing metrics
This commit adds a new usermetric package and wires
up metrics across the tailscale client.

Updates tailscale/corp#22075

Co-authored-by: Anton Tolchanov <anton@tailscale.com>
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
2 months 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>
3 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>
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
4 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>
5 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>
5 months ago
Maisem Ali 42cfbf427c tsnet,wgengine/netstack: add ListenPacket and tests
This adds a new ListenPacket function on tsnet.Server
which acts mostly like `net.ListenPacket`.

Unlike `Server.Listen`, this requires listening on a
specific IP and does not automatically listen on both
V4 and V6 addresses of the Server when the IP is unspecified.

To test this, it also adds UDP support to tsdial.Dialer.UserDial
and plumbs it through the localapi. Then an associated test
to make sure the UDP functionality works from both sides.

Updates #12182

Signed-off-by: Maisem Ali <maisem@tailscale.com>
5 months ago
Brad Fitzpatrick 21509db121 ipn/ipnlocal, all: plumb health trackers in tests
I saw some panics in CI, like:

    2024-05-08T04:30:25.9553518Z ## WARNING: (non-fatal) nil health.Tracker (being strict in CI):
    2024-05-08T04:30:25.9554043Z goroutine 801 [running]:
    2024-05-08T04:30:25.9554489Z tailscale.com/health.(*Tracker).nil(0x0)
    2024-05-08T04:30:25.9555086Z 	tailscale.com/health/health.go:185 +0x70
    2024-05-08T04:30:25.9555688Z tailscale.com/health.(*Tracker).SetUDP4Unbound(0x0, 0x0)
    2024-05-08T04:30:25.9556373Z 	tailscale.com/health/health.go:532 +0x2f
    2024-05-08T04:30:25.9557296Z tailscale.com/wgengine/magicsock.(*Conn).bindSocket(0xc0003b4808, 0xc0003b4878, {0x1fbca53, 0x4}, 0x0)
    2024-05-08T04:30:25.9558301Z 	tailscale.com/wgengine/magicsock/magicsock.go:2481 +0x12c5
    2024-05-08T04:30:25.9559026Z tailscale.com/wgengine/magicsock.(*Conn).rebind(0xc0003b4808, 0x0)
    2024-05-08T04:30:25.9559874Z 	tailscale.com/wgengine/magicsock/magicsock.go:2510 +0x16f
    2024-05-08T04:30:25.9561038Z tailscale.com/wgengine/magicsock.NewConn({0xc000063c80, 0x0, 0xc000197930, 0xc000197950, 0xc000197960, {0x0, 0x0}, 0xc000197970, 0xc000198ee0, 0x0, ...})
    2024-05-08T04:30:25.9562402Z 	tailscale.com/wgengine/magicsock/magicsock.go:476 +0xd5f
    2024-05-08T04:30:25.9563779Z tailscale.com/wgengine.NewUserspaceEngine(0xc000063c80, {{0x22c8750, 0xc0001976b0}, 0x0, {0x22c3210, 0xc000063c80}, {0x22c31d8, 0x2d3c900}, 0x0, 0x0, ...})
    2024-05-08T04:30:25.9564982Z 	tailscale.com/wgengine/userspace.go:389 +0x159d
    2024-05-08T04:30:25.9565529Z tailscale.com/ipn/ipnlocal.newTestBackend(0xc000358b60)
    2024-05-08T04:30:25.9566086Z 	tailscale.com/ipn/ipnlocal/serve_test.go:675 +0x2a5
    2024-05-08T04:30:25.9566612Z ta

Updates #11874

Change-Id: I3432ed52d670743e532be4642f38dbd6e3763b1b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
6 months ago
Fran Bull 6a0fbacc28 appc: setting AdvertiseRoutes explicitly discards app connector routes
This fixes bugs where after using the cli to set AdvertiseRoutes users
were finding that they had to restart tailscaled before the app
connector would advertise previously learned routes again. And seems
more in line with user expectations.

Fixes #11006
Signed-off-by: Fran Bull <fran@tailscale.com>
6 months ago
Brad Fitzpatrick 6d69fc137f ipn/{ipnlocal,localapi},wgengine{,/magicsock}: plumb health.Tracker
Down to 25 health.Global users. After this remains controlclient &
net/dns & wgengine/router.

Updates #11874
Updates #4136

Change-Id: I6dd1856e3d9bf523bdd44b60fb3b8f7501d5dc0d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
6 months ago
Brad Fitzpatrick ebc552d2e0 health: add Tracker type, in prep for removing global variables
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>
6 months ago
Joe Tsai 63b3c82587
ipn/local: log OS-specific diagnostic information as JSON (#11700)
There is an undocumented 16KiB limit for text log messages.
However, the limit for JSON messages is 256KiB.
Even worse, logging JSON as text results in significant overhead
since each double quote needs to be escaped.

Instead, use logger.Logf.JSON to explicitly log the info as JSON.

We also modify osdiag to return the information as structured data
rather than implicitly have the package log on our behalf.
This gives more control to the caller on how to log.

Updates #7802

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
6 months ago
Brad Fitzpatrick 7c1d6e35a5 all: use Go 1.22 range-over-int
Updates #11058

Change-Id: I35e7ef9b90e83cac04ca93fd964ad00ed5b48430
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick 7ec0dc3834 ipn/ipnlocal: make StartLoginInteractive take (yet unused) context
In prep for future fix to undermentioned issue.

Updates tailscale/tailscale#7036

Change-Id: Ide114db917dcba43719482ffded6a9a54630d99e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Claire Wang 9171b217ba
cmd/tailscale, ipn/ipnlocal: add suggest exit node CLI option (#11407)
Updates tailscale/corp#17516

Signed-off-by: Claire Wang <claire@tailscale.com>
7 months ago
Brad Fitzpatrick b9aa7421d6 ipn/ipnlocal: remove some dead code (legacyBackend methods) from LocalBackend
Nothing used it.

Updates #11649

Change-Id: Ic1c331d947974cd7d4738ff3aafe9c498853689e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Brad Fitzpatrick a5e1f7d703 ipn/{ipnlocal,localapi}: add API to toggle use of exit node
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>
7 months ago
Brad Fitzpatrick 38377c37b5 ipn/localapi: sort localapi handler map keys
Updates #cleanup

Change-Id: I750ed8d033954f1f8786fb35dd16895bb1c5af8e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
7 months ago
Charlotte Brandhorst-Satzkorn 8c75da27fc
drive: move normalizeShareName into pkg drive and make func public (#11638)
This change makes the normalizeShareName function public, so it can be
used for validation in control.

Updates tailscale/corp#16827

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
7 months ago
Charlotte Brandhorst-Satzkorn 98cf71cd73
tailscale: switch tailfs to drive syntax for api and logs (#11625)
This change switches the api to /drive, rather than the previous /tailfs
as well as updates the log lines to reflect the new value. It also
cleans up some existing tailfs references.

Updates tailscale/corp#16827

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
7 months ago
Charlotte Brandhorst-Satzkorn 93618a3518
tailscale: update tailfs functions and vars to use drive naming (#11597)
This change updates all tailfs functions and the majority of the tailfs
variables to use the new drive naming.

Updates tailscale/corp#16827

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
7 months ago
Charlotte Brandhorst-Satzkorn 14683371ee
tailscale: update tailfs file and package names (#11590)
This change updates the tailfs file and package names to their new
naming convention.

Updates #tailscale/corp#16827

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>
7 months ago
Percy Wegmann 66e4d843c1 ipn/localapi: add support for multipart POST to file-put
This allows sending multiple files via Taildrop in one request.
Progress is tracked via ipn.Notify.

Updates tailscale/corp#18202

Signed-off-by: Percy Wegmann <percy@tailscale.com>
7 months ago
Percy Wegmann bed818a978 ipn/localapi: add support for multipart POST to file-put
This allows sending multiple files via Taildrop in one request.
Progress is tracked via ipn.Notify.

Updates tailscale/corp#18202

Signed-off-by: Percy Wegmann <percy@tailscale.com>
7 months ago
James Tucker e0f97738ee localapi: reduce garbage production in bus watcher
Updates #optimization

Signed-off-by: James Tucker <james@tailscale.com>
7 months ago
Brad Fitzpatrick ad33e47270 ipn/{ipnlocal,localapi}: add debug verb to force spam IPN bus NetMap
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>
8 months ago
Percy Wegmann e496451928 ipn,cmd/tailscale,client/tailscale: add support for renaming TailFS shares
- Updates API to support renaming TailFS shares.
- Adds a CLI rename subcommand for renaming a share.
- Renames the CLI subcommand 'add' to 'set' to make it clear that
  this is an add or update.
- Adds a unit test for TailFS in ipnlocal

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
8 months ago
Percy Wegmann 6c160e6321 ipn,tailfs: tie TailFS share configuration to user profile
Previously, the configuration of which folders to share persisted across
profile changes. Now, it is tied to the user's profile.

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
8 months ago
Andrea Gottardo 0cb86468ca ipn/localapi: add set-gui-visible endpoint
Updates tailscale/corp#17859

Provides a local API endpoint to be called from the GUI to inform the backend when the client menu is opened or closed.

cc @bradfitz

Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
Signed-off-by: Andrea Gottardo <andrea@tailscale.com>
Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
8 months ago
Percy Wegmann abab0d4197 tailfs: clean up naming and package structure
- Restyles tailfs -> tailFS
- Defines interfaces for main TailFS types
- Moves implemenatation of TailFS into tailfsimpl package

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
9 months ago
Percy Wegmann 993acf4475 tailfs: initial implementation
Add a WebDAV-based folder sharing mechanism that is exposed to local clients at
100.100.100.100:8080 and to remote peers via a new peerapi endpoint at
/v0/tailfs.

Add the ability to manage folder sharing via the new 'share' CLI sub-command.

Updates tailscale/corp#16827

Signed-off-by: Percy Wegmann <percy@tailscale.com>
9 months ago
kari-ts 5595b61b96
ipn/localapi: more http status cleanup (#10995)
Use Http.StatusOk instead of 200

Updates #cleanup
9 months ago
Andrew Dunham d3574a350f cmd/tailscale, ipn/ipnlocal: add 'debug dial-types' command
This command allows observing whether a given dialer ("SystemDial",
"UserDial", etc.) will successfully obtain a connection to a provided
host, from inside tailscaled itself. This is intended to help debug a
variety of issues from subnet routers to split DNS setups.

Updates #9619

Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Ie01ebb5469d3e287eac633ff656783960f697b84
10 months ago
Sonia Appasamy ac6f671c54 ipn/localapi: use clientupdate.CanAutoUpdate from serveUpdateCheck
Fixes #10486

Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
11 months ago
Sonia Appasamy bd534b971a {client/web},{ipn/ipnlocal}: replace localapi debug-web-client endpoint
This change removes the existing debug-web-client localapi endpoint
and replaces it with functions passed directly to the web.ServerOpts
when constructing a web.ManageServerMode client.

The debug-web-client endpoint previously handled making noise
requests to the control server via the /machine/webclient/ endpoints.
The noise requests must be made from tailscaled, which has the noise
connection open. But, now that the full client is served from
tailscaled, we no longer need to proxy this request over the localapi.

Updates tailscale/corp#14335

Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
12 months ago
Brad Fitzpatrick 3bd382f369 wgengine/magicsock: add DERP homeless debug mode for testing
In DERP homeless mode, a DERP home connection is not sought or
maintained and the local node is not reachable.

Updates #3363
Updates tailscale/corp#396

Change-Id: Ibc30488ac2e3cfe4810733b96c2c9f10a51b8331
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
12 months ago
Naman Sood e57fd9cda4
ipn/{ipnlocal,ipnstate,localapi}: add localapi endpoints for client self-update (#10188)
* ipn/{ipnlocal,ipnstate,localapi}: add localapi endpoints for client self-update

Updates #10187.

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

* depaware

Updates #10187.

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

* address review feedback

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

---------

Signed-off-by: Naman Sood <mail@nsood.in>
12 months ago
Andrew Lytvynov 55cd5c575b
ipn/localapi: only perform local-admin check in serveServeConfig (#10163)
On unix systems, the check involves executing sudo, which is slow.
Instead of doing it for every incoming request, move the logic into
localapi serveServeConfig handler and do it as needed.

Updates tailscale/corp#15405

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
12 months ago
Jordan Whited 12d5c99b04
client/tailscale,ipn/{ipnlocal,localapi}: check UDP GRO config (#10071)
Updates tailscale/corp#9990

Signed-off-by: Jordan Whited <jordan@tailscale.com>
12 months ago
Andrew Lytvynov 9b158db2c6
ipn/localapi: require root or sudo+operator access for SetServeConfig (#10142)
For an operator user, require them to be able to `sudo tailscale` to use
`tailscale serve`. This is similar to the Windows elevated token check.

Updates tailscale/corp#15405

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
12 months ago
Andrew Lytvynov f0bc95a066
ipn/localapi: make serveTKASign require write permission (#10094)
The existing read permission check looks like an oversight. Write seems
more appropriate for sining new nodes.

Updates https://github.com/tailscale/corp/issues/15506

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
1 year ago
Sonia Appasamy da31ce3a64 ipn/localapi: remove webclient endpoint
Managing starting/stopping tailscaled web client purely via setting
the RunWebClient pref.

Updates tailscale/corp#14335

Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
1 year ago
Andrew Lytvynov c6a4612915
ipn/localapi: require Write access on /watch-ipn-bus with private keys (#10059)
Clients optionally request private key filtering. If they don't, we
should require Write access for the user.

Updates https://github.com/tailscale/corp/issues/15506

Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
1 year ago
Sonia Appasamy 44175653dc ipn/ipnlocal: rename web fields/structs to webClient
For consistency and clarity around what the LocalBackend.web field
is used for.

Updates tailscale/corp#14335

Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
1 year ago