This tripped me up when I was testing something and wrote:
if conn != nil {
conn.Close()
}
In netstack mode, when an error occurred we were getting a non-nil error
and a non-nil interface that contained a nil pointer. Instead, just
return a nil interface value.
Updates #cleanup
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: Id9ef3dd24529e0e8c53adc60ed914c31fbb10cc4
A Tailnet node can be told to stop advertise subnets by passing
an empty string to --advertise-routes flag.
Respect an explicitly passed empty value to TS_ROUTES env var
so that users have a way to stop containerboot acting as a subnet
router without recreating it.
Distinguish between TS_ROUTES being unset and empty.
Updates tailscale/tailscale#10708
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
The service is only used as a watchdog and for piping logs from the child
process. We shouldn't be creating a network monitor in that case.
Fixes#10732
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
The cmpx.Compare function (and associated interface) are now available
in the standard library as cmp.Compare. Remove our version of it and use
the version from the standard library.
Updates #cleanup
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I4be3ac63d466c05eb7a0babb25cb0d41816fbd53
When auto-update setting in local Prefs is unset, apply the tailnet
default value from control. This only happens once, when we apply the
default (or when the user manually overrides it), tailnet default no
longer affects the node.
Updates #16244
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
Instead of taking the first UPnP response we receive and using that to
create port mappings, store all received UPnP responses, sort and
deduplicate them, and then try all of them to obtain an external
address.
Updates #10602
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I783ccb1834834ee2a9ecbae2b16d801f2354302f
connector-gen can initially generate connector ACL snippets and
advertise-routes flags for Github and AWS based on their public IP /
domain data.
Updates ENG-2425
Signed-off-by: James Tucker <james@tailscale.com>
* k8s-operator,cmd/k8s-operator,Makefile,scripts,.github/workflows: add Connector kube CRD.
Connector CRD allows users to configure the Tailscale Kubernetes operator
to deploy a subnet router to expose cluster CIDRs or
other CIDRs available from within the cluster
to their tailnet.
Also adds various CRD related machinery to
generate CRD YAML, deep copy implementations etc.
Engineers will now have to run
'make kube-generate-all` after changing kube files
to ensure that all generated files are up to date.
* cmd/k8s-operator,k8s-operator: reconcile Connector resources
Reconcile Connector resources, create/delete subnetrouter resources in response to changes to Connector(s).
Connector reconciler will not be started unless
ENABLE_CONNECTOR env var is set to true.
This means that users who don't want to use the alpha
Connector custom resource don't have to install the Connector
CRD to their cluster.
For users who do want to use it the flow is:
- install the CRD
- install the operator (via Helm chart or using static manifests).
For Helm users set .values.enableConnector to true, for static
manifest users, set ENABLE_CONNECTOR to true in the static manifest.
Updates tailscale/tailscale#502
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
This uses the fact that we've received a frame from a given DERP region
within a certain time as a signal that the region is stil present (and
thus can still be a node's PreferredDERP / home region) even if we don't
get a STUN response from that region during a netcheck.
This should help avoid DERP flaps that occur due to losing STUN probes
while still having a valid and active TCP connection to the DERP server.
RELNOTE=Reduce home DERP flapping when there's still an active connection
Updates #8603
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: If7da6312581e1d434d5c0811697319c621e187a0
Initial implementation of a `tailscale whois` subcommand
which allows users to observe metadata associated with a
Tailscale IP. It also has a `--json` flag to allow consumption
programmatically.
Updates #4217
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Previously were always setting `UseSocketOnly` because we were
comparing `args.socketpath != ""`, but `args.socketpath` flag
always gets filled with `paths.DefaultTailscaledSocket()` when
not provided. Rather than comparing to the empty string, compare
to the default value to determine if `UseSocketOnly` should be
set.
Should fix issue with web client being unreachable for Mac App
Store variant of the mac build.
Updates #16054
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
Instead of overloading the Version field, add an explicit Track field.
This fixes a bug where passing a track name in `args.Version` would keep
the track name in `updater.Version` and pass it down the code path to
commands like `apt-get install`. Now, `updater.Version` should always be
a version (or empty string).
Updates #cleanup
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
`tailscaled` and `tailscale` expect the socket to be at
`/var/run/tailscale/tailscaled.sock`, however containerboot
would set up the socket at `/tmp/tailscaled.sock`. This leads to a
poor UX when users try to use any `tailscale` command as they
have to prefix everything with `--socket /tmp/tailscaled.sock`.
To improve the UX, this adds a symlink to
`/var/run/tailscale/tailscaled.sock` to point to `/tmp/tailscaled.sock`.
This approach has two benefits, 1 users are able to continue to use
existing scripts without this being a breaking change. 2. users are
able to use the `tailscale` CLI without having to add the `--socket` flag.
Fixes tailscale/corp#15902
Fixes#6849Fixes#10027
Signed-off-by: Maisem Ali <maisem@tailscale.com>
Some fields if `ipn.Prefs` are structs. `ipn.MaskedPrefs` has a single
level of boolean `*Set` flags, which doesn't map well to nested structs
within `ipn.Prefs`.
Change `MaskedPrefs` and `ApplyEdits` to support `FooSet` struct fields
that map to a nested struct of `ipn.Prefs` like `AutoUpdates`. Each
struct field in `MaskedPrefs` is just a bundle of more `Set` bool fields
or other structs. This allows you to have a `Set` flag for any
arbitrarily-nested field of `ipn.Prefs`.
Also, make `ApplyEdits` match fields between `Prefs` and `MaskedPrefs`
by name instead of order, to make it a bit less finicky. It's probably
slower but `ipn.ApplyEdits` should not be in any hot path.
As a result, `AutoUpdate.Check` and `AutoUpdate.Apply` fields don't
clobber each other when set individually.
Updates #16247
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
Precompress webclient assets with precompress util. This cuts our
css and js build sizes to about 1/3 of non-compressed size. Similar
compression done on tsconnect and adminhttp assets.
Updates #10261
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
* cmd/k8s-operator: generate static manifests from Helm charts
This is done to ensure that there is a single source of truth
for the operator kube manifests.
Also adds linux node selector to the static manifests as
this was added as a default to the Helm chart.
Static manifests can now be generated by running
`go generate tailscale.com/cmd/k8s-operator`.
Updates tailscale/tailscale#9222
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
The recent addition of RequestID was only populated if the
HTTP Request had returned an error. This meant that the underlying
handler has no access to this request id and any logs it may have
emitted were impossible to correlate to that request id. Therefore,
this PR adds a middleware to generate request ids and pass them
through the request context. The tsweb.StdHandler automatically
populates this request id if the middleware is being used. Finally,
inner handlers can use the context to retrieve that same request id
and use it so that all logs and events can be correlated.
Updates #2549
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
Adds policy keys ExitNodeID and ExitNodeIP.
Uses the policy keys to determine the exit node in preferences.
Fixestailscale/corp#15683
Signed-off-by: Claire Wang <claire@tailscale.com>
To be consistent with the formatting of other warnings, pass available
update health message instead of handling ClientVersion in he CLI.
Fixes#10312
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
Enforcing inclusion of our OSS license at the top of .ts and .tsx
files. Also updates any relevant files in the repo that were
previously missing the license comment. An additional `@license`
comment is added to client/web/src/index.tsx to preserve the
license in generated Javascript.
Updates #10261
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
We warn users about IP forwarding being disabled when using
`--avertise-routes` in `tailscale up`, this adds the same warnings
to `tailscale set`.
Updates tailscale/corp#9968
Signed-off-by: Jenny Zhang <jz@tailscale.com>
* cmd/containerboot: proxy traffic to tailnet target defined by FQDN
Add a new Service annotation tailscale.com/tailnet-fqdn that
users can use to specify a tailnet target for which
an egress proxy should be deployed in the cluster.
Updates tailscale/tailscale#10280
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
This records test coverage for the amd64 no race tests and uploads the
results to coveralls.io.
Updates #cleanup
Signed-off-by: Ox Cart <ox.to.a.cart@gmail.com>
Kubernetes can generate StatefulSet names that are too long and result in invalid Pod revision hash label values.
Calculate whether a StatefulSet name generated for a Service or Ingress
will be too long and if so, truncate it.
Updates tailscale/tailscale#10284
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
It's possible to do this with a combination of watch-ipn and jq, but looking
at the netmap while debugging is quite common, so it's nice to have a one-shot
command to get it.
Updates #cleanup
Signed-off-by: David Anderson <danderson@tailscale.com>
jq doens't like non-json output in the json stream, and works more happily
when the input stream EOFs at some point. Move non-json words to stderr, and
add a parameter to stop watching and exit after some number of objects.
Updates #cleanup
Signed-off-by: David Anderson <danderson@tailscale.com>
This PR starts to persist the NetMap tailnet name in SetPrefs so that tailscaled
clients can use this value to disambiguate fast user switching from one tailnet
to another that are under the same exact login. We will also try to backfill
this information during backend starts and profile switches so that users don't
have to re-authenticate their profile. The first client to use this new
information is the CLI in 'tailscale switch -list' which now uses text/tabwriter
to display the ID, Tailnet, and Account. Since account names are ambiguous, we
allow the user to pass 'tailscale switch ID' to specify the exact tailnet they
want to switch to.
Updates #9286
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
* cmd/containerboot: shut down cleanly on SIGTERM
Make sure that tailscaled watcher returns when
SIGTERM is received and also that it shuts down
before tailscaled exits.
Updates tailscale/tailscale#10090
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
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>
Now that we have nftable support this works fine and force
it on gokrazy since 25a8daf405.
Updates gokrazy/gokrazy#209
Signed-off-by: Maisem Ali <maisem@tailscale.com>
No longer using this! Readonly state fully managed via auth endpoint.
Also getting rid of old Legacy server mode.
A #cleanup
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
For consistency with the "WebClient" naming of the other functions
here. Also fixed a doc typo.
A #cleanup
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
This PR changes the internal getTokenInfo function to use generics.
I also removed our own implementations for obtaining a token's user
and primary group in favour of calling the ones now available in
x/sys/windows.
Furthermore, I added two new functions for working with tokens, logon
session IDs, and Terminal Services / RDP session IDs.
I modified our privilege enabling code to allow enabling of multiple
privileges via one single function call.
Finally, I added the ProcessImageName function and updated the code in
tailscaled_windows.go to use that instead of directly calling the
underlying API.
All of these changes will be utilized by subsequent PRs pertaining to
this issue.
Updates https://github.com/tailscale/corp/issues/13998
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
Now that 1.54 has released, and the new web client will be included in
1.56, we can remove the need for the node capability. This means that
all 1.55 unstable builds, and then eventually the 1.56 build, will work
without setting the node capability.
The web client still requires the "webclient" user pref, so this does
NOT mean that the web client will be on by default for all devices.
Updates tailscale/corp#14335
Signed-off-by: Will Norris <will@tailscale.com>
This removes the dev/unstable build check for the --webclient flag on
`tailscale set`, so that it will be included in the next major stable
release (1.56)
Updates tailscale/corp#14335
Signed-off-by: Will Norris <will@tailscale.com>
This prevents running more than one recursive resolution for the same
hostname in parallel, which can use excessive amounts of CPU when called
in a tight loop. Additionally, add tests that hit the network (when
run with a flag) to test the lookup behaviour.
Updates tailscale/corp#15261
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I39351e1d2a8782dd4c52cb04b3bd982eb651c81e
Causing issues building a stable release. Getting rid of the flag
for now because it was only available in unstable, can still be
turned on through localapi.
A #cleanup
Co-authored-by: Will Norris <will@tailscale.com>
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
`winutil.WTSGetActiveConsoleSessionId` only works for physical desktop
logins and does not return the session ID for RDP logins. We need to
`windows.WTSEnumerateSessions` and find the active session.
Fixes https://github.com/tailscale/corp/issues/15772
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
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>
This package is a wrapper for os/user that handles non-cgo builds,
gokrazy and user shells.
Updates tailscale/corp#15405
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
If the status request to check for the preview node cap fails,
continue with starting up the legacy client.
Updates tailscale/corp#14335
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
After running `tailscale web`, only disable the user pref if it was not
already previously set.
Updates tailscale/corp#14335
Signed-off-by: Will Norris <will@tailscale.com>
Avoids the need to pipe a web client dev flag through the tailscaled
command.
Updates tailscale/corp#14335
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
Adds a new Mode to the web server, indicating the specific
scenario the constructed server is intended to be run in. Also
starts filling this from the cli/web and ipn/ipnlocal callers.
From cli/web this gets filled conditionally based on whether the
preview web client node cap is set. If not set, the existing
"legacy" client is served. If set, both a login/lobby and full
management client are started (in "login" and "manage" modes
respectively).
Updates tailscale/corp#14335
Signed-off-by: Sonia Appasamy <sonia@tailscale.com>
The design changed during integration and testing, resulting in the
earlier implementation growing in the appc package to be intended now
only for the sniproxy implementation. That code is moved to it's final
location, and the current App Connector code is now renamed.
Updates tailscale/corp#15437
Signed-off-by: James Tucker <james@tailscale.com>
In corp PR #14970 I updated the installer to set a security mitigation that
always forces system32 to the front of the Windows dynamic linker's search
path.
Unfortunately there are other products out there that, partying like it's
1995, drop their own, older version of wintun.dll into system32. Since we
look there first, we end up loading that old version.
We can fix this by preloading wintun using a fully-qualified path. When
wintun-go then loads wintun, the dynamic linker will hand it the module
that was previously loaded by us.
Fixes#10023, #10025, #10052
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
Updates tailscale/tailscale#9222
plain k8s-operator should have hostinfo.App set to 'k8s-operator', operator with proxy should have it set to 'k8s-operator-proxy'. In proxy mode, we were setting the type after it had already been set to 'k8s-operator'
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
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>
API v1 is compatible with helm v2 and v2 is not.
However, helm v2 (the Tiller deployment mechanism) was deprecated in 2020
and no-one should be using it anymore.
This PR also adds a CI lint test for helm chart
Updates tailscale/tailscale#9222
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
The derphttp client automatically reconnects upon failure.
RunWatchConnectionLoop called derphttp.Client.WatchConnectionChanges
once, but that wrapper method called the underlying
derp.Client.WatchConnectionChanges exactly once on derphttp.Client's
currently active connection. If there's a failure, we need to re-subscribe
upon all reconnections.
This removes the derphttp.Client.WatchConnectionChanges method, which
was basically impossible to use correctly, and changes it to be a
boolean field on derphttp.Client alongside MeshKey and IsProber. Then
it moves the call to the underlying derp.Client.WatchConnectionChanges
to derphttp's client connection code, so it's resubscribed on any
reconnect.
Some paranoia is then added to make sure people hold the API right,
not calling derphttp.Client.RunWatchConnectionLoop on an
already-started Client without having set the bool to true. (But still
auto-setting it to true if that's the first method that's been called
on that derphttp.Client, as is commonly the case, and prevents
existing code from breaking)
Fixestailscale/corp#9916
Supercedes tailscale/tailscale#9719
Co-authored-by: Val <valerie@tailscale.com>
Co-authored-by: Irbe Krumina <irbe@tailscale.com>
Co-authored-by: Anton Tolchanov <anton@tailscale.com>
Signed-off-by: Brad Fitzpatrick <brad@danga.com>
* Implement missing tests for sniproxy
* Wire sniproxy to new appc package
* Add support to tsnet for routing subnet router traffic into netstack, so it can be handled
Updates: https://github.com/tailscale/corp/issues/15038
Signed-off-by: Tom DNetto <tom@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>
We were inconsistent whether we checked if the feature was already
enabled which we could do cheaply using the locally available status.
We would do the checks fine if we were turning on funnel, but not serve.
This moves the cap checks down into enableFeatureInteractive so that
are always run.
Updates #9984
Co-authored-by: Tyler Smalley <tyler@tailscale.com>
Signed-off-by: Maisem Ali <maisem@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>
We prevent shodow configs when starting a foreground when a background serve config already exists for the serve type and port. This PR improves the messaging to let the user know how to remove the previous config.
Updates #8489
ENG-2314
Signed-off-by: Tyler Smalley <tyler@tailscale.com>
The `--http` flag can not be used with Funnel, so we should remove it to remove confusion.
Updates #8489
ENG-2316
Signed-off-by: Tyler Smalley <tyler@tailscale.com>
This PR changes the -https, -http, -tcp, and -tls-terminated-tcp
flags from string to int and also updates the validation to ensure
they fit the uint16 size as the flag library does not have a Uint16Var
method.
Updates #8489
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
The TestServeDevConfigMutations test has 63 steps that all run
under the same scope. This tests breaks them out into isolated
subtests that can be run independently.
Updates #8489
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
We currently print out "run tailscale serve --help" when the subcmd
might be funnel. This PR ensures the right subcmd is passed.
Updates #8489
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
On `tailscale set --auto-update`, set the Sparkle plist option for it.
Also make macsys report not supporting auto-updates over c2n, since they
will be triggered by Sparkle locally.
Updates #755
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
A few people have run into issues with understanding why `--set-path` started in background mode, and/or why they couldn't use a path in foreground mode. This change allows `--set-path` to be used in either case (foreground or background).
updates #8489
Signed-off-by: Tyler Smalley <tyler@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>
* Fixes issue with template string not being provided in help text
* Updates background information to provide full URL, including path, to make it clear the source and destination
* Restores some tests
* Removes AllowFunnel in ServeConfig if no proxy exists for that port.
updates #8489
Signed-off-by: Tyler Smalley <tyler@tailscale.com>
This PR adds the same set-raw from the old flow into the new one
so that users can continue to use it when transitioning into the new
flow.
Updates #8489
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
This PR fixes the isLegacyInvocation to better catch serve and
funnel legacy commands. In addition, it now also returns a string
that translates the old command into the new one so that users
can have an easier transition story.
Updates #8489
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
This PR allows you to do "tailscale serve -bg -https:4545 off" and it
will delete all handlers under it. It will also prompt you for a y/n in case
you wanted to delete a single port.
Updates #8489
Signed-off-by: Marwan Sulaiman <marwan@tailscale.com>
Users should delete proxies by deleting or modifying the k8s cluster resources
that they used to tell the operator to create they proxy. With this flow,
the tailscale operator will delete the associated device from the control.
However, in some cases users might have already deleted the device from the control manually.
Updates tailscale/tailscale#9773
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
We no longer build Windows releases with cgo enabled, which
automatically turned off certstore support. Rather than re-enabling cgo,
we updated our fork of the certstore package to no longer require cgo.
This updates the package, cleans up how the feature is configured, and
removes the cgo build tag requirement.
Fixestailscale/corp#14797Fixestailscale/coral#118
Change-Id: Iaea34340761c0431d759370532c16a48c0913374
Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
In the sandboxed app from the app store, we cannot check
`/Library/Preferences/com.apple.commerce.plist` or run `softwareupdate`.
We can at most print a helpful message and open the app store page.
Also, reenable macsys update function to mark it as supporting c2n
updates. macsys support in `tailscale update` was fixed.
Updates #755
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
