The AppConnector is now configured by the mapcap from the control plane.
Updates tailscale/corp#15437
Signed-off-by: James Tucker <james@tailscale.com>
An EmbeddedAppConnector is added that when configured observes DNS
responses from the PeerAPI. If a response is found matching a configured
domain, routes are advertised when necessary.
The wiring from a configuration in the netmap capmap is not yet done, so
while the connector can be enabled, no domains can yet be added.
Updates tailscale/corp#15437
Signed-off-by: James Tucker <james@tailscale.com>
WebClientShutdown tries to acquire the b.mu lock, so run it in a go
routine so that it can finish shutdown after setPrefsLockedOnEntry is
finished. This is the same reason b.sshServer.Shutdown is run in a go
routine.
Updates tailscale/corp#14335
Signed-off-by: Will Norris <will@tailscale.com>
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>
instead of starting a separate server listening on a particular port,
use the TCPHandlerForDst method to intercept requests for the special
web client port (currently 5252, probably configurable later).
Updates tailscale/corp#14335
Signed-off-by: Will Norris <will@tailscale.com>
This is not currently exposed as a user-settable preference through
`tailscale up` or `tailscale set`. Instead, the preference is set when
turning the web client on and off via localapi. In a subsequent commit,
the pref will be used to automatically start the web client on startup
when appropriate.
Updates tailscale/corp#14335
Signed-off-by: Will Norris <will@tailscale.com>
Allows for serving the web interface from tailscaled, with the
ability to start and stop the server via localapi endpoints
(/web/start and /web/stop).
This will be used to run the new full management web client,
which will only be accessible over Tailscale (with an extra auth
check step over noise) from the daemon. This switch also allows
us to run the web interface as a long-lived service in environments
where the CLI version is restricted to CGI, allowing us to manage
certain auth state in memory.
ipn/ipnlocal/web is stubbed out in ipn/ipnlocal/web_stub for
ios builds to satisfy ios restriction from adding "text/template"
and "html/template" dependencies.
Updates tailscale/corp#14335
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
* ipn/localapi: add endpoint to handle APNS payloads
Fixes#9971. This adds a new `handle-push-message` local API endpoint. When an APNS payload is delivered to the main app, this endpoint can be used to forward the JSON body of the message to the backend, making a POST request.
cc @bradfitz
Signed-off-by: Andrea Gottardo <andrea@tailscale.com>
* Address comments from code review
Signed-off-by: Andrea Gottardo <andrea@tailscale.com>
---------
Signed-off-by: Andrea Gottardo <andrea@tailscale.com>
For a serve config with a path handler, ensure the caller is a local administrator on Windows.
updates #8489
Signed-off-by: Tyler Smalley <tyler@tailscale.com>
On Windows, the idiomatic way to check access on a named pipe is for
the server to impersonate the client on its current OS thread, perform
access checks using the client's access token, and then revert the OS
thread's access token back to its true self.
The access token is a better representation of the client's rights than just
a username/userid check, as it represents the client's effective rights
at connection time, which might differ from their normal rights.
This patch updates safesocket to do the aforementioned impersonation,
extract the token handle, and then revert the impersonation. We retain
the token handle for the remaining duration of the connection (the token
continues to be valid even after we have reverted back to self).
Since the token is a property of the connection, I changed ipnauth to wrap
the concrete net.Conn to include the token. I then plumbed that change
through ipnlocal, ipnserver, and localapi as necessary.
I also added a PermitLocalAdmin flag to the localapi Handler which I intend
to use for controlling access to a few new localapi endpoints intended
for configuring auto-update.
Updates https://github.com/tailscale/tailscale/issues/755
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
In addition to the new policy keys for the new options, some
already-in-use but missing policy keys are also being added to
util/syspolicy.
Updates ENG-2133
Change-Id: Iad08ca47f839ea6a65f81b76b4f9ef21183ebdc6
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
clientupdate.Updater will have a non-nil Update func in a few cases
where it doesn't actually perform an update:
* on Arch-like distros, where it prints instructions on how to update
* on macOS app store version, where it opens the app store page
Add a new clientupdate.Arguments field to cause NewUpdater to fail when
we hit one of these cases. This results in c2n updates being "not
supported" and `tailscale set --auto-update` returning an error.
Updates #755
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
It would end up resetting whatever hostinfo we had constructed
and leave the backend statemachine in a broken state.
This fixes that by storing the PushDeviceToken on the LocalBackend
and populating it on Hostinfo before passing it to controlclient.
Updates tailscale/corp#8940
Updates tailscale/corp#15367
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The value being passed was the same as whats on b.hostinfo, so just
use that directly.
Updates #cleanup
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Go has no way to explicitly identify Go struct as effectively a tuple,
so staticcheck assumes any external use of unkeyed literals is wrong.
Updates #cleanup
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This adds a check to prevent changes to ServeConfig if tailscaled
is run with a Locked config.
Missed in 1fc3573446.
Updates #1412
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This commit makes two changes to the web client auth flow error
handling:
1. Properly passes back the error code from the noise request from
the localapi. Previously we were using io.Copy, which was always
setting a 200 response status code.
2. Clean up web client browser sessions on any /wait endpoint error.
This avoids the user getting in a stuck state if something goes
wrong with their auth path.
Updates tailscale/corp#14335
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
Ensure that when a userspace proxy config is reloaded,
connections for any removed proxies are safely closed
Updates tailscale/tailscale#9725
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
Initiates http/h2c transport for userspace proxy
backend lazily and at most once.
Updates tailscale/tailscale#9725
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
Connects serveTailscaleAuth to the localapi webclient endpoint
and pipes auth URLs and session cookies back to the browser to
redirect users from the frontend.
All behind debug flags for now.
Updates tailscale/corp#14335
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
Updates userspace proxy to detect plaintext grpc requests
using the preconfigured host prefix and request's content
type header and ensure that these will be proxied over h2c.
Updates tailscale/tailscale#9725
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
While the previous logic was correct, it did not perform well.
Resuming is a dance between the client and server, where
1. the client requests hashes for a partial file,
2. the server then computes those hashes,
3. the client computes hashes locally and compares them.
4. goto 1 while the partial file still has data
While step 2 is running, the client is sitting idle.
While step 3 is running, the server is sitting idle.
By streaming over the block hash immediately after the server
computes it, the client can start checking the hash,
while the server works on the next hash (in a pipelined manner).
This performs dramatically better and also uses less memory
as we don't need to hold a list of hashes, but only need to
handle one hash at a time.
There are two detriments to this approach:
* The HTTP API relies on a JSON stream,
which is not a standard REST-like pattern.
However, since we implement both client and server,
this is fine.
* While the stream is on-going, we hold an open file handle
on the server side while the file is being hashed.
On really slow streams, this could hold a file open forever.
Updates tailscale/corp#14772
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Co-authored-by: Rhea Ghosh <rhea@tailscale.com>
Minor fixes:
* The branch for listing or hashing partial files was inverted.
* The host for peerapi call needs to be real (rather than bogus).
* Handle remote peers that don't support resuming.
* Make resume failures non-fatal (since we can still continue).
This was tested locally, end-to-end system test is future work.
Updates tailscale/corp#14772
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Co-authored-by: Rhea Ghosh <rhea@tailscale.com>
Two bug fixes:
1. when tailscale update is executed as root, `os.UserCacheDir` may
return an error because `$XDG_CACHE_HOME` and `$HOME` are not set;
fallback to `os.TempDir` in those cases
2. on some weird distros (like my EndeavourOS), `/usr/sbin` is just a
symlink to `/usr/bin`; when we resolve `tailscale` binary path from
`tailscaled`, allow `tailscaled` to be in either directory
Updates #755
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
File resumption requires keeping partial files around for some time,
but we must still eventually delete them if never resumed.
Thus, we implement asynchronous file deletion, which could
spawn a background goroutine to delete the files.
We also use the same mechanism for deleting files on Windows,
where a file can't be deleted if there is still an open file handle.
We can enqueue those with the asynchronous file deleter as well.
Updates tailscale/corp#14772
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
The old code would always retain value `true` if it was set once, even
if you then change `prefs.AutoUpdate.Apply` to `false`.
Instead of using the previous value, use the default (envknob) value to
OR with.
Updates #755
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
This change:
* adds a partial files peerAPI endpoint to get a list of partial files
* adds a helper function to extract the basename of a file
* updates the peer put peerAPI endpoint
* updates the file put localapi endpoint to allow resume functionality
Updates #14772
Signed-off-by: Rhea Ghosh <rhea@tailscale.com>
The Sparkle-based update is not quite working yet. Make `NewUpdater`
return `ErrUnsupported` for it to avoid the proliferation of exceptions
up the stack.
Updates #755
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
Debug endpoint for the web client's auth flow to talk back to the
control server. Restricted behind a feature flag on control.
We will either be removing this debug endpoint, or renaming it
before launching the web client updates.
Updates tailscale/corp#14335
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
This commit changes the PostureChecking syspolicy key to be a
PreferenceOption(user-defined, always, never) instead of Bool.
This aligns better with the defaults implementation on macOS allowing
CLI arguments to be read when user-defined or no defaults is set.
Updates #tailscale/tailscale/5902
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
We add the following API:
* type FileChecksums
* type Checksum
* func Manager.PartialFiles
* func Manager.HashPartialFile
* func ResumeReader
The Manager methods provide the ability to query for partial files
and retrieve a list of checksums for a given partial file.
The ResumeReader function is a helper that wraps an io.Reader
to discard content that is identical locally and remotely.
The FileChecksums type represents the checksums of a file
and is safe to JSON marshal and send over the wire.
Updates tailscale/corp#14772
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Co-authored-by: Rhea Ghosh <rhea@tailscale.com>
We were eagerly doing a synchronous renewal of the cert while
trying to serve traffic. Instead of that, just do the cert
renewal in the background and continue serving traffic as long
as the cert is still valid.
This regressed in c1ecae13ab when
we introduced ARI support and were trying to make the experience
of `tailscale cert` better. However, that ended up regressing
the experience for tsnet as it would not always doing the renewal
synchronously.
Fixes#9783
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Changes made:
* Move all HTTP related functionality from taildrop to ipnlocal.
* Add two arguments to taildrop.Manager.PutFile to specify
an opaque client ID and a resume offset (both unused for now).
* Cleanup the logic of taildrop.Manager.PutFile
to be easier to follow.
* Implement file conflict handling where duplicate files are renamed
(e.g., "IMG_1234.jpg" -> "IMG_1234 (2).jpg").
* Implement file de-duplication where "renaming" a partial file
simply deletes it if it already exists with the same contents.
* Detect conflicting active puts where a second concurrent put
results in an error.
Updates tailscale/corp#14772
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Co-authored-by: Rhea Ghosh <rhea@tailscale.com>
These log paths were actually unexpected until the refactor in
fe95d81b43. This moves the logs
to the callsites where they are actually unexpected.
Fixes#9670
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The current structure meant that we were embedding netstack in
the tailscale CLI and in the GUIs. This removes that by isolating
the checksum munging to a different pkg which is only called from
`net/tstun`.
Fixes#9756
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The whois handler was documented as taking IP (e.g. 100.101.102.103)
or IP:port (e.g. usermode 127.0.0.1:1234) but that got broken at some point
and we started requiring a port always. Fix that.
Also, found in the process of adding tests: fix the CapMap lookup in
userspace mode (it was always returning the caps of 127.0.0.1 in
userspace mode). Fix and test that too.
Updates #9714
Change-Id: Ie9a59744286522fa91c4b70ebe89a1e94dbded26
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit adds support for getting serial numbers from SMBIOS
on Windows/Linux (and BSD) using go-smbios.
Updates #5902
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
Changes made:
* Unexport declarations specific to internal taildrop functionality.
* Document all exported functionality.
* Move TestRedactErr to the taildrop package.
* Rename and invert Handler.DirectFileDoFinalRename as AvoidFinalRename.
Updates tailscale/corp#14772
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
This is being moved to taildrop, so clean it up to stop depending
on so much unreleated functionality by removing a dependency
on peerAPIHandler.
Updates tailscale/corp#14772
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Co-authored-by: Rhea Ghosh <rhea@tailscale.com>
Over time all taildrop functionality will be contained in the
taildrop package. This will include end to end unit tests. This is
simply the first smallest piece to move over.
There is no functionality change in this commit.
Updates tailscale/corp#14772
Signed-off-by: Rhea Ghosh <rhea@tailscale.com>
Co-authored-by: Joseph Tsai <joetsai@tailscale.com>
Adds `getTailscaleBrowserSession` to pull the user's session out of
api requests, and `serveTailscaleAuth` to provide the "/api/auth"
endpoint for browser to request auth status and new sessions.
Updates tailscale/corp#14335
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
Advertise it on Android (it looks like it already works once advertised).
And both advertise & likely fix it on iOS. Yet untested.
Updates #9672
Change-Id: If3b7e97f011dea61e7e75aff23dcc178b6cf9123
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This optionally uploads MAC address(es) to control, then adds a
c2n handler so control can ask a node to send a WoL packet.
Updates #306
RELNOTE=now supports waking up peer nodes on your LAN via Wake-on-LAN packets
Change-Id: Ibea1275fcd2048dc61d7059039abfbaf1ad4f465
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Make the 'tailscale debug component-logs' command print the component names for
which extra logging can be turned on, for easier discoverability of debug
functions.
Updates #cleanup
Co-authored-by: Paul Scott <paul@tailscale.com>
Signed-off-by: Val <valerie@tailscale.com>
Thanks to @qur and @eric for debugging!
Fixes#6973
Change-Id: Ib2cf8f030cf595cc73dd061c72e78ac19f5fae5d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
These were missed when adding NodeCapMap and resulted
in tsnet binaries not being able to turn on funnel.
Fixes#9566
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Control sends ExitNodeDNSResolvers when configured for IsWireGuardOnly
nodes that are to be used as the default resolver with a lower
precedence than split DNS, and a lower precedence than "Override local
DNS", but otherwise before local DNS is used when the exit node is in
use.
Neither of the below changes were problematic, but appeared so alongside
a number of other client and external changes. See tailscale/corp#14809.
Reland ea9dd8fabc.
Reland d52ab181c3.
Updates #9377
Updates tailscale/corp#14809
Signed-off-by: James Tucker <james@tailscale.com>
Prepare for path MTU discovery by splitting up the concept of
DefaultMTU() into the concepts of the Tailscale TUN MTU, MTUs of
underlying network interfaces, minimum "safe" TUN MTU, user configured
TUN MTU, probed path MTU to a peer, and maximum probed MTU. Add a set
of likely MTUs to probe.
Updates #311
Signed-off-by: Val <valerie@tailscale.com>
This PR ensures zombie foregrounds are shutdown if a new
ServeConfig is created that wipes the ongoing foreground ones.
For example, "tailscale serve|funnel reset|off" should close
all open sessions.
Updates #8489
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
For loading testing & profiling the cost of full netmap updates.
Updates #1909
Change-Id: I0afdf5de9967f8d95c7f81d5b531ed1c92c3208f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Prepare for path MTU discovery by splitting up the concept of
DefaultMTU() into the concepts of the Tailscale TUN MTU, MTUs of
underlying network interfaces, minimum "safe" TUN MTU, user configured
TUN MTU, probed path MTU to a peer, and maximum probed MTU. Add a set
of likely MTUs to probe.
Updates #311
Signed-off-by: Val <valerie@tailscale.com>
This would've prevented #9470.
This used to pass, fails as of 9538e9f970, and passes again
once #9472 is in.
Updates #9470
Change-Id: Iab97666f7a318432fb3b6372a177ab50c55d4697
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
9538e9f970 broke LocalBackend.WhoIs
where you can no longer lookup yourself in WhoIs.
This occurs because the LocalBackend.peers map only contains peers.
If we fail to lookup a peer, double-check whether it is ourself.
Fixes#9470
Signed-off-by: Joe Tsai <joetsai@digital-static.net>
Co-authored-by: Rhea Ghosh <rhea@tailscale.com>
The initial implementation directly mirrored the behavior of Tailscale
exit nodes, where the WireGuard exit node DNS took precedence over other
configuration.
This adjusted implementation treats the WireGuard DNS
resolvers as a lower precedence default resolver than the tailnet
default resolver, and allows split DNS configuration as well.
This also adds test coverage to the existing DNS selection behavior with
respect to default resolvers and split DNS routes for Tailscale exit
nodes above cap 25. There may be some refinement to do in the logic in
those cases, as split DNS may not be working as we intend, though that
would be a pre-existing and separate issue.
Updates #9377
Signed-off-by: James Tucker <james@tailscale.com>
This PR plumbs through awareness of an IPv6 SNAT/masquerade address from the wire protocol
through to the low-level (tstun / wgengine). This PR is the first in two PRs for implementing
IPv6 NAT support to/from peers.
A subsequent PR will implement the data-plane changes to implement IPv6 NAT - this is just plumbing.
Signed-off-by: Tom DNetto <tom@tailscale.com>
Updates ENG-991
Like PeerCapMap, add a field to `tailcfg.Node` which provides
a map of Capability to raw JSON messages which are deferred to be
parsed later by the application code which cares about the specific
capabilities. This effectively allows us to prototype new behavior
without having to commit to a schema in tailcfg, and it also opens up
the possibilities to develop custom behavior in tsnet applications w/o
having to plumb through application specific data in the MapResponse.
Updates #4217
Signed-off-by: Maisem Ali <maisem@tailscale.com>
And convert all callers over to the methods that check SelfNode.
Now we don't have multiple ways to express things in tests (setting
fields on SelfNode vs NetworkMap, sometimes inconsistently) and don't
have multiple ways to check those two fields (often only checking one
or the other).
Updates #9443
Change-Id: I2d7ba1cf6556142d219fae2be6f484f528756e3c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We have some flaky integration tests elsewhere that have no one place
to ask about the state of the world. This makes LocalBackend be that
place (as it's basically there anyway) but doesn't yet add the ForTest
accessor method.
This adds a LocalBackend.peers map[NodeID]NodeView that is
incrementally updated as mutations arrive. And then we start moving
away from using NetMap.Peers at runtime (UpdateStatus no longer uses
it now). And remove another copy of NodeView in the LocalBackend
nodeByAddr map. Change that to point into b.peers instead.
Future changes will then start streaming whole-node-granularity peer
change updates to WatchIPNBus clients, tracking statefully per client
what each has seen. This will get the GUI clients from receiving less
of a JSON storm of updates all the time.
Updates #1909
Change-Id: I14a976ca9f493bdf02ba7e6e05217363dcf422e5
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
NetworkMap.Addresses is redundant with the SelfNode.Addresses. This
works towards a TODO to delete NetworkMap.Addresses and replace it
with a method.
This is similar to #9389.
Updates #cleanup
Change-Id: Id000509ca5d16bb636401763d41bdb5f38513ba0
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
* Remove unnecessary mutexes (there's no concurrency)
* Simplify LocalBackend.UpdateStatus using the StatusBuilder.WantPeers
field that was added in 0f604923d3, removing passing around some
method values into func args. And then merge two methods.
More remains, but this is a start.
Updates #9433
Change-Id: Iaf2d7ec6e4e590799f00bae185465a4fd089b822
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This enables installing default resolvers specified by
tailcfg.Node.ExitNodeDNSResolvers when the exit node is selected.
Updates #9377
Signed-off-by: James Tucker <james@tailscale.com>
This PR uses the etag/if-match pattern to ensure multiple calls
to SetServeConfig are synchronized. It currently errors out and
asks the user to retry but we can add occ retries as a follow up.
Updates #8489
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
It has one user (LocalBackend) which can ask magicsock itself.
Updates #cleanup
Change-Id: I8c03cbb1e5ba57b0b442621b5fa467030c14a2e2
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
General cleanup and additional test coverage of WIP code.
* use enum for serveType
* combine instances of ServeConfig access within unset
* cleanMountPoint rewritten into cleanURLPath as it only handles URL paths
* refactor and test expandProxyTargetDev
> **Note**
> Behind the `TAILSCALE_USE_WIP_CODE` flag
updates #8489
Signed-off-by: Tyler Smalley <tyler@tailscale.com>
(continuing the mission of removing rando methods from the Engine
interface that we don't need anymore)
Updates #cleanup
Change-Id: Id5190917596bf04d7185c3b331a852724a3f5a16
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
We always have one. Stop pretending we might not.
Instead, add one early panic in NewLocalBackend if we actually don't.
Updates #cleanup
Change-Id: Iba4b78ed22cb6248e59c2b01a79355ca7a200ec8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
LocalBackend can talk to magicsock on its own to do this without
the "Engine" being involved.
(Continuing a little side quest of cleaning up the Engine
interface...)
Updates #cleanup
Change-Id: I8654acdca2b883b1bd557fdc0cfb90cd3a418a62
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
It had exactly one user: netstack. Just have LocalBackend notify
netstack when here's a new netmap instead, simplifying the bloated
Engine interface that has grown a bunch of non-Engine-y things.
(plenty of rando stuff remains after this, but it's a start)
Updates #cleanup
Change-Id: I45e10ab48119e962fc4967a95167656e35b141d8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Currently only the top four most popular changes: endpoints, DERP
home, online, and LastSeen.
Updates #1909
Change-Id: I03152da176b2b95232b56acabfb55dcdfaa16b79
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
I missed connecting some controlknobs.Knobs pieces in 4e91cf20a8
resulting in that breaking control knobs entirely.
Whoops.
The fix in ipn/ipnlocal (where it makes a new controlclient) but to
atone, I also added integration tests. Those integration tests use
a new "tailscale debug control-knobs" which by itself might be useful
for future debugging.
Updates #9351
Change-Id: Id9c89c8637746d879d5da67b9ac4e0d2367a3f0d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
