Commit Graph

222 Commits (b9bd7dbc5dda17b7b8abb938092aa0a625c27056)

Author SHA1 Message Date
Josh Bleecher Snyder a4e19f2233 version: remove rsc.io/goversion dependency
rsc.io/goversion is really expensive.
Running version.ReadExe on tailscaled on darwin
allocates 47k objects, almost 11mb.

All we want is the module info. For that, all we need to do
is scan through the binary looking for the magic start/end strings
and then grab the bytes in between them.

We can do that easily and quickly with nothing but a 64k buffer.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
David Crawshaw 360223fccb types/dnstype: introduce new package for Resolver
So the type can be used in net/dns without introducing a tailcfg
dependency.

For #2596

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Josh Bleecher Snyder eee6b85b9b cmd/tailscaled: don't require root for --cleanup
Without this, the integration tests fail locally for me:

--- FAIL: TestCollectPanic (7.61s)
    integration.go:74: built [tailscale.com/cmd/tailscaled tailscale.com/cmd/tailscale] in 1.59s
    integration_test.go:102: initial run: tailscaled requires root; use sudo tailscaled (or use --tun=userspace-networking)
    integration_test.go:108: cleanup failed: exit status 1: "tailscaled requires root; use sudo tailscaled (or use --tun=userspace-networking)\n"
    stuntest.go:64: STUN server shutdown
FAIL
FAIL	tailscale.com/tstest/integration	9.678s
FAIL

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder a5da4ed981 all: gofmt with Go 1.17
This adds "//go:build" lines and tidies up existing "// +build" lines.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Brad Fitzpatrick a729070252 net/tstun: add start of Linux TAP support, with DHCP+ARP server
Still very much a prototype (hard-coded IPs, etc) but should be
non-invasive enough to submit at this point and iterate from here.

Updates #2589

Co-Author: David Crawshaw <crawshaw@tailscale.com>
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick fd7b738e5b derp: use pad32 package for padding, reduce duplication
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick fdc081c291 net/portmapper: fix UPnP probing, work against all ports
Prior to Tailscale 1.12 it detected UPnP on any port.
Starting with Tailscale 1.11.x, it stopped detecting UPnP on all ports.

Then start plumbing its discovered Location header port number to the
code that was assuming port 5000.

Fixes #2109

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 1db9032ff5 cmd/tailscaled: let portmap debug mode have an gateway/IP override knob
For testing pfSense clients "behind" pfSense on Digital Ocean where
the main interface still exists. This is easier for debugging.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 31ea073a73 cmd/tailscaled: add debug -portmap mode
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
David Crawshaw 3e039daf95 logpolicy: actually collect panics
(Written with Josh)

For #2544

Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
3 years ago
Josh Bleecher Snyder 9da4181606 tstime/rate: new package
This is a simplified rate limiter geared for exactly our needs:
A fast, mono.Time-based rate limiter for use in tstun.
It was generated by stripping down the x/time/rate rate limiter
to just our needs and switching it to use mono.Time.

It removes one time.Now call per packet.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder 8a3d52e882 wgengine/magicsock: use mono.Time
magicsock makes multiple calls to Now per packet.
Move to mono.Now. Changing some of the calls to
use package mono has a cascading effect,
causing non-per-packet call sites to also switch.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Josh Bleecher Snyder c2202cc27c net/tstun: use mono.Time
There's a call to Now once per packet.
Move to mono.Now.

Though the current implementation provides high precision,
we document it to be coarse, to preserve the ability
to switch to a coarse monotonic time later.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
3 years ago
Joe Tsai d145c594ad
util/deephash: improve cycle detection (#2470)
The previous algorithm used a map of all visited pointers.
The strength of this approach is that it quickly prunes any nodes
that we have ever visited before. The detriment of the approach
is that pruning is heavily dependent on the order that pointers
were visited. This is especially relevant for hashing a map
where map entries are visited in a non-deterministic manner,
which would cause the map hash to be non-deterministic
(which defeats the point of a hash).

This new algorithm uses a stack of all visited pointers,
similar to how github.com/google/go-cmp performs cycle detection.
When we visit a pointer, we push it onto the stack, and when
we leave a pointer, we pop it from the stack.
Before visiting a pointer, we first check whether the pointer exists
anywhere in the stack. If yes, then we prune the node.
The detriment of this approach is that we may hash a node more often
than before since we do not prune as aggressively.

The set of visited pointers up until any node is only the
path of nodes up to that node and not any other pointers
that may have been visited elsewhere. This provides us
deterministic hashing regardless of visit order.
We can now delete hashMapFallback and associated complexity,
which only exists because the previous approach was non-deterministic
in the presence of cycles.

This fixes a failure of the old algorithm where obviously different
values are treated as equal because the pruning was too aggresive.
See https://github.com/tailscale/tailscale/issues/2443#issuecomment-883653534

The new algorithm is slightly slower since it prunes less aggresively:
	name              old time/op    new time/op    delta
	Hash-8              66.1µs ± 1%    68.8µs ± 1%   +4.09%        (p=0.000 n=19+19)
	HashMapAcyclic-8    63.0µs ± 1%    62.5µs ± 1%   -0.76%        (p=0.000 n=18+19)
	TailcfgNode-8       9.79µs ± 2%    9.88µs ± 1%   +0.95%        (p=0.000 n=19+17)
	HashArray-8          643ns ± 1%     653ns ± 1%   +1.64%        (p=0.000 n=19+19)
However, a slower but more correct algorithm seems
more favorable than a faster but incorrect algorithm.

Signed-off-by: Joe Tsai <joetsai@digital-static.net>
3 years ago
Brad Fitzpatrick ed8587f90d wgengine/router: take a link monitor
Prep for #1591 which will need to make Linux's router react to changes
that the link monitor observes.

The router package already depended on the monitor package
transitively. Now it's explicit.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick 7f7a81e5ae cmd/tailscaled: add func to create ipnserver.Opts
To unify the Windows service and non-service/non-Windows paths a bit.

And provides a way to make Linux act like Windows for testing.
(notably, for testing the fix to #2137)

One perhaps visible change of this is that tailscaled.exe when run in
cmd.exe/powershell (not as a Windows Service) no longer uses the
"_daemon" autostart key. But in addition to being naturally what falls
out of this change, that's also what Windows users would likely want,
as otherwise the unattended mode user is ignored when the "_daemon"
autostart key is specified. Notably, this would let people debug what
their normally-run-as-a-service tailscaled is doing, even when they're
running in Unattended Mode.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
Brad Fitzpatrick ec4d721572 cmd/tailscaled: use state key constant from ipn package
Rather than redefining it again.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
3 years ago
julianknodt 1bb6abc604 net/portmapper: add upnp port mapping
Add in UPnP portmapping, using goupnp library in order to get the UPnP client and run the
portmapping functions. This rips out anywhere where UPnP used to be in portmapping, and has a
flow separate from PMP and PCP.

RELNOTE=portmapper now supports UPnP mappings

Fixes #682
Updates #2109

Signed-off-by: julianknodt <julianknodt@gmail.com>
3 years ago
Christine Dodrill a19eea965f
tstest/integration/vms: use an in-process logcatcher (#2360)
This adapts the existing in-process logcatcher from tstest/integration
into a public type and uses it on the side of testcontrol. This also
fixes a bug in the Alpine Linux OpenRC unit that makes every value in
`/etc/default/tailscaled` exported into tailscaled's environment, a-la
systemd [Service].EnviromentFile.

Signed-off-by: Christine Dodrill <xe@tailscale.com>
3 years ago
Brad Fitzpatrick 700badd8f8 util/deephash: move internal/deephash to util/deephash
No code changes. Just a minor package doc addition about lack of API
stability.
3 years ago
Maisem Ali ec52760a3d wgengine/router_windows: support toggling local lan access when using
exit nodes.

Signed-off-by: Maisem Ali <maisem@tailscale.com>
4 years ago
julianknodt 506c2fe8e2 cmd/tailscale: make netcheck use active DERP map, delete static copy
After allowing for custom DERP maps, it's convenient to be able to see their latency in
netcheck. This adds a query to the local tailscaled for the current DERPMap.

Updates #1264

Signed-off-by: julianknodt <julianknodt@gmail.com>
4 years ago
Brad Fitzpatrick 3910c1edaf net/socks5/tssocks: add new package, move SOCKS5 glue out of tailscaled
Prep for #1970, #2264, #2268

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 82e15d3450 cmd/tailscaled: log SOCKS5 port when port 0 requested
Part of #2158

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Brad Fitzpatrick 10d7c2583c net/dnsfallback: don't depend on derpmap.Prod
Move derpmap.Prod to a static JSON file (go:generate'd) instead,
to make its role explicit. And add a TODO about making dnsfallback
use an update-over-time DERP map file instead of a baked-in one.

Updates #1264

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
julianknodt 148602a89a derp,cmd/derper: allow server to verify clients
This adds a flag to the DERP server which specifies to verify clients through a local
tailscaled. It is opt-in, so should not affect existing clients, and is mainly intended for
users who want to run their own DERP servers. It assumes there is a local tailscaled running and
will attempt to hit it for peer status information.

Updates #1264

Signed-off-by: julianknodt <julianknodt@gmail.com>
4 years ago
Brad Fitzpatrick 38be964c2b go.mod: update netstack
Fixes a atomic alignment crash on 32-bit machines.

Fixes #2129
Fixes tailscale/tailscale-synology#66 (same)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Denton Gentry ad288baaea net/interfaces: use IPv4 link local if nothing better
The only connectivity an AWS Lambda container has is an IPv4 link-local
169.254.x.x address using NAT:
12: vtarget_1@if11: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500
                    qdisc noqueue state UP group default qlen 1000
     link/ether 7e:1c:3f:00:00:00 brd ff:ff:ff:ff:ff:ff link-netnsid 1
     inet 169.254.79.1/32 scope global vtarget_1
     valid_lft forever preferred_lft forever

If there are no other IPv4/v6 addresses available, and we are running
in AWS Lambda, allow IPv4 169.254.x.x addresses to be used.

----

Similarly, a Google Cloud Run container's only connectivity is
a Unique Local Address fddf:3978:feb1:d745::c001/128.
If there are no other addresses available then allow IPv6
Unique Local Addresses to be used.
We actually did this in an earlier release, but now refactor it to
work the same way as the IPv4 link-local support is being done.

Signed-off-by: Denton Gentry <dgentry@tailscale.com>
4 years ago
Brad Fitzpatrick 03311bb0d6 hostinfo: add hostinfo package, move stuff out of controlclient
And make it cheaper, so other parts of the code can check the
environment.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
David Anderson ac07ff43bf cmd/tailscaled: start after NetworkManager and systemd-resolved.
The dependency is a "soft" ordering dependency only, meaning that
tailscaled will start after those services if those services were
going to be run anyway, but doesn't force either of them to run.
That's why it's safe to specify this dependency unconditionally,
even for systems that don't run those services.

Updates #2127.

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Christine Dodrill 8b2b899989
tstest/integration: test Alpine Linux (#2098)
Alpine Linux[1] is a minimal Linux distribution built around musl libc.
It boots very quickly, requires very little ram and is as close as you
can get to an ideal citizen for testing Tailscale on musl. Alpine has a
Tailscale package already[2], but this patch also makes it easier for us
to provide an Alpine Linux package off of pkgs in the future.

Alpine only offers Tailscale on the rolling-release edge branch.

[1]: https://alpinelinux.org/
[2]: https://pkgs.alpinelinux.org/packages?name=tailscale&branch=edge

Updates #1988

Signed-off-by: Christine Dodrill <xe@tailscale.com>
4 years ago
Maisem Ali f944614c5c cmd/tailscale/web: add support for QNAP
Signed-off-by: Maisem Ali <maisem@tailscale.com>
4 years ago
Matt Layher 6956645ec8 go.mod: bump github.com/mdlayher/netlink to v1.4.1
Signed-off-by: Matt Layher <mdlayher@gmail.com>
4 years ago
Adrian Dewhurst 6d6cf88d82 control/controlclient: use our fork of certstore
The cyolosecurity fork of certstore did not update its module name and
thus can only be used with a replace directive. This interferes with
installing using `go install` so I created a tailscale fork with an
updated module name.

Signed-off-by: Adrian Dewhurst <adrian@tailscale.com>
4 years ago
Josh Bleecher Snyder 1ece91cede go.mod: upgrade wireguard-windows, de-fork wireguard-go
Pull in the latest version of wireguard-windows.

Switch to upstream wireguard-go.
This requires reverting all of our import paths.

Unfortunately, this has to happen at the same time.
The wireguard-go change is very low risk,
as that commit matches our fork almost exactly.
(The only changes are import paths, CI files, and a go.mod entry.)
So if there are issues as a result of this commit,
the first place to look is wireguard-windows changes.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick a86a0361a7 go.mod: upgrade all deps
At the start of a dev cycle we'll upgrade all dependencies.

Done with:

$ for Dep in $(cat go.mod | perl -ne '/(\S+) v/ and print "$1\n"'); do go get $Dep@upgrade; done

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Josh Bleecher Snyder 5666663370 net/packet: use netaddr AppendTo methods
This lets us remote the types/strbuilder package,
which had only a single user.
And it's faster.

name              old time/op    new time/op    delta
String/tcp4-8        175ns ± 0%      58ns ± 1%  -66.95%  (p=0.000 n=10+9)
String/tcp6-8        226ns ± 1%     136ns ± 1%  -39.85%  (p=0.000 n=10+10)
String/udp4-8        175ns ± 1%      58ns ± 1%  -67.01%  (p=0.000 n=10+9)
String/udp6-8        230ns ± 1%     140ns ± 0%  -39.32%  (p=0.000 n=10+9)
String/icmp4-8       164ns ± 0%      50ns ± 1%  -69.89%  (p=0.000 n=10+10)
String/icmp6-8       217ns ± 1%     129ns ± 0%  -40.46%  (p=0.000 n=10+10)
String/igmp-8        196ns ± 0%      56ns ± 1%  -71.32%  (p=0.000 n=10+10)
String/unknown-8    2.06ns ± 1%    2.06ns ± 2%     ~     (p=0.985 n=10+10)

name              old alloc/op   new alloc/op   delta
String/tcp4-8        32.0B ± 0%     32.0B ± 0%     ~     (all equal)
String/tcp6-8         168B ± 0%       96B ± 0%  -42.86%  (p=0.000 n=10+10)
String/udp4-8        32.0B ± 0%     32.0B ± 0%     ~     (all equal)
String/udp6-8         168B ± 0%       96B ± 0%  -42.86%  (p=0.000 n=10+10)
String/icmp4-8       32.0B ± 0%     32.0B ± 0%     ~     (all equal)
String/icmp6-8        104B ± 0%       64B ± 0%  -38.46%  (p=0.000 n=10+10)
String/igmp-8        48.0B ± 0%     48.0B ± 0%     ~     (all equal)
String/unknown-8     0.00B          0.00B          ~     (all equal)

name              old allocs/op  new allocs/op  delta
String/tcp4-8         1.00 ± 0%      1.00 ± 0%     ~     (all equal)
String/tcp6-8         3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
String/udp4-8         1.00 ± 0%      1.00 ± 0%     ~     (all equal)
String/udp6-8         3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
String/icmp4-8        1.00 ± 0%      1.00 ± 0%     ~     (all equal)
String/icmp6-8        3.00 ± 0%      1.00 ± 0%  -66.67%  (p=0.000 n=10+10)
String/igmp-8         1.00 ± 0%      1.00 ± 0%     ~     (all equal)
String/unknown-8      0.00           0.00          ~     (all equal)

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Maisem Ali 234cc87f48 cmd/tailscaled: use the wf package instead of wireguard-windows/firewall
Signed-off-by: Maisem Ali <maisem@tailscale.com>
4 years ago
Josh Bleecher Snyder 25df067dd0 all: adapt to opaque netaddr types
This commit is a mishmash of automated edits using gofmt:

gofmt -r 'netaddr.IPPort{IP: a, Port: b} -> netaddr.IPPortFrom(a, b)' -w .
gofmt -r 'netaddr.IPPrefix{IP: a, Port: b} -> netaddr.IPPrefixFrom(a, b)' -w .

gofmt -r 'a.IP.Is4 -> a.IP().Is4' -w .
gofmt -r 'a.IP.As16 -> a.IP().As16' -w .
gofmt -r 'a.IP.Is6 -> a.IP().Is6' -w .
gofmt -r 'a.IP.As4 -> a.IP().As4' -w .
gofmt -r 'a.IP.String -> a.IP().String' -w .

And regexps:

\w*(.*)\.Port = (.*)  ->  $1 = $1.WithPort($2)
\w*(.*)\.IP = (.*)  ->  $1 = $1.WithIP($2)

And lots of manual fixups.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
4 years ago
Brad Fitzpatrick 36a26e6a71 internal/deephash: rename from deepprint
Yes, it printed, but that was an implementation detail for hashing.

And coming optimization will make it print even less.

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Josh Bleecher Snyder 9360f36ebd all: use lower-case letters at the start of error message
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
Avery Pennarun 19c3e6cc9e types/logger: rate limited: more hysteresis, better messages.
- Switch to our own simpler token bucket, since x/time/rate is missing
  necessary stuff (can't provide your own time func; can't check the
  current bucket contents) and it's overkill anyway.

- Add tests that actually include advancing time.

- Don't remove the rate limit on a message until there's enough room to
  print at least two more of them. When we do, we'll also print how
  many we dropped, as a contextual reminder that some were previously
  lost. (This is more like how the Linux kernel does it.)

- Reformat the [RATE LIMITED] messages to be shorter, and to not
  corrupt original message. Instead, we print the message, then print
  its format string.

- Use %q instead of \"%s\", for more accurate parsing later, if the
  format string contained quotes.

Fixes #1772

Signed-off-by: Avery Pennarun <apenwarr@tailscale.com>
4 years ago
Josh Bleecher Snyder 20e04418ff net/dns: add GOOS build tags
Fixes #1786

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
Josh Bleecher Snyder 3c543c103a wgengine/magicsock: unify initial bind and rebind
We had two separate code paths for the initial UDP listener bind
and any subsequent rebinds.

IPv6 got left out of the rebind code.
Rather than duplicate it there, unify the two code paths.
Then improve the resulting code:

* Rebind had nested listen attempts to try the user-specified port first,
  and then fall back to :0 if that failed. Convert that into a loop.
* Initial bind tried only the user-specified port.
  Rebind tried the user-specified port and 0.
  But there are actually three ports of interest:
  The one the user specified, the most recent port in use, and 0.
  We now try all three in order, as appropriate.
* In the extremely rare case in which binding to port 0 fails,
  use a dummy net.PacketConn whose reads block until close.
  This will keep the wireguard-go receive func goroutine alive.

As a pleasant side-effect of this, if we decide that
we need to resuscitate #1796, it will now be much easier.

Fixes #1799

Co-authored-by: David Anderson <danderson@tailscale.com>
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
Josh Bleecher Snyder 8fb66e20a4 wgengine/magicsock: remove DefaultPort const
Assume it'll stay at 0 forever, so hard-code it
and delete code conditional on it being non-0.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
4 years ago
David Anderson 25ce9885a2 net/dns: don't use NM+resolved for NM >=1.26.6.
NetworkManager fixed the bug that forced us to use NetworkManager
if it's programming systemd-resolved, and in the same release also
made NetworkManager ignore DNS settings provided for unmanaged
interfaces... Which breaks what we used to do. So, with versions
1.26.6 and above, we MUST NOT use NetworkManager to indirectly
program systemd-resolved, but thankfully we can talk to resolved
directly and get the right outcome.

Fixes #1788

Signed-off-by: David Anderson <danderson@tailscale.com>
4 years ago
Aleksandar Pesic 7c985e4944 ipn/ipnlocal: add file sharing to windows shell
Updates: tailscale/winmin#33

Signed-off-by: Aleksandar Pesic <peske.nis@gmail.com>
4 years ago
Brad Fitzpatrick 91c9c33036 cmd/tailscaled: don't block ipnserver startup behind engine init on Windows
With this change, the ipnserver's safesocket.Listen (the localhost
tcp.Listen) happens right away, before any synchronous
TUN/DNS/Engine/etc setup work, which might be slow, especially on
early boot on Windows.

Because the safesocket.Listen starts up early, that means localhost
TCP dials (the safesocket.Connect from the GUI) complete successfully
and thus the GUI avoids the MessageBox error. (I verified that
pacifies it, even without a Listener.Accept; I'd feared that Windows
localhost was maybe special and avoided the normal listener backlog).

Once the GUI can then connect immediately without errors, the various
timeouts then matter less, because the backend is no longer trying to
race against the GUI's timeout. So keep retrying on errors for a
minute, or 10 minutes if the system just booted in the past 10
minutes.

This should fix the problem with Windows 10 desktops auto-logging in
and starting the Tailscale frontend which was then showing a
MessageBox error about failing to connect to tailscaled, which was
slow coming up because the Windows networking stack wasn't up
yet. Fingers crossed.

Fixes #1313 (previously #1187, etc)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago
Alex Brainman 7689213aaa cmd/tailscaled: add subcommands to install and remove tailscaled Windows service
This change implements Windows version of install-system-daemon and
uninstall-system-daemon subcommands. When running the commands the
user will install or remove Tailscale Windows service.

Updates #1232

Signed-off-by: Alex Brainman <alex.brainman@gmail.com>
4 years ago
Brad Fitzpatrick f99e63bb17 ipn: don't Logout when Windows GUI disconnects
Logout used to be a no-op, so the ipnserver previously synthensized a Logout
on disconnect. Now that Logout actually invalidates the node key that was
forcing all GUI closes to log people out.

Instead, add a method to LocalBackend to specifically mean "the
Windows GUI closed, please forget all the state".

Fixes tailscale/corp#1591 (ignoring the notification issues, tracked elsewhere)

Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
4 years ago