For the service, all we need to do is handle the `svc.SessionChange` command.
Upon receipt of a `windows.WTS_SESSION_UNLOCK` event, we fire off a goroutine to flush the DNS cache.
(Windows expects responses to service requests to be quick, so we don't want to do that synchronously.)
This is gated on an integral registry value named `FlushDNSOnSessionUnlock`,
whose value we obtain during service initialization.
(See [this link](https://docs.microsoft.com/en-us/windows/win32/api/winsvc/nc-winsvc-lphandler_function_ex) for information re: handling `SERVICE_CONTROL_SESSIONCHANGE`.)
Fixes#2956
Signed-off-by: Aaron Klotz <aaron@tailscale.com>
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>
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>
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>
This is usually the same as the requested interface, but on some
unixes can vary based on device number allocation, and on Windows
it's the GUID instead of the pretty name, since everything relating
to configuration wants the GUID.
Signed-off-by: David Anderson <danderson@tailscale.com>
This makes setup more explicit in prod codepaths, without
requiring a bunch of arguments or helpers for tests and
userspace mode.
Signed-off-by: David Anderson <danderson@tailscale.com>
So we can empty import the guts of cmd/tailscaled from another
module for go mod tidy reasons.
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
