eventbus.Publish() calls newPublisher(), which in turn invokes (*Client).addPublisher().
That method adds the new publisher to c.pub, so we don’t need to add it again in eventbus.Publish.
Updates #cleanup
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We update LocalBackend to shut down the current nodeBackend
when switching to a different node, and to mark the new node's
nodeBackend as ready when the switch completes.
Updates tailscale/corp#28014
Updates tailscale/corp#29543
Updates #12614
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Using WINHTTP_AUTOPROXY_ALLOW_AUTOCONFIG on Windows versions older than Windows 10 1703 (build 15063)
is not supported and causes WinHttpGetProxyForUrl to fail with ERROR_INVALID_PARAMETER. This results in failures
reaching the control on environments where a proxy is required.
We use wingoes version detection to conditionally set the WINHTTP_AUTOPROXY_ALLOW_AUTOCONFIG flag
on Windows builds greater than 15063.
While there, we also update proxy detection to use WINHTTP_AUTO_DETECT_TYPE_DNS_A, as DNS-based proxy discovery
might be required with Active Directory and in certain other environments.
Updates tailscale/corp#29168
Fixes#879
Signed-off-by: Nick Khyl <nickk@tailscale.com>
The field must only be accessed while holding LocalBackend's mutex,
but there are two places where it's accessed without the mutex:
- (LocalBackend).MaybeClearAppConnector()
- handleC2NAppConnectorDomainRoutesGet()
Fixes#16123
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Currently, LocalBackend/ExtensionHost doesn't invoke the profile change callback for the initial profile.
Since the initial profile may vary depending on loaded extensions and applied policy settings,
it can't be reliably determined until all extensions are initialized. Additionally, some extensions
may asynchronously trigger a switch to the "best" profile (based on system state and policy settings) during
initialization.
We intended to address these issues as part of the ongoing profileManager/LocalBackend refactoring,
but the changes didn't land in time for the v1.84 release and the Taildrop refactoring.
In this PR, we update the Taildrop extension to retrieve the current profile at initialization time
and handle it as a profile change.
We also defer extension initialization until LocalBackend has started, since the Taildrop extension
already relies on this behavior (e.g., it requires clients to call SetDirectFileRoot before Init).
Fixes#15970
Updates #15812
Updates tailscale/corp#28449
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we make DNS registration behavior configurable via the EnableDNSRegistration policy setting.
We keep the default behavior unchanged, but allow admins to either enforce DNS registration and dynamic
DNS updates for the Tailscale interface, or prevent Tailscale from modifying the settings configured in
the network adapter's properties or by other means.
Updates #14917
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In tailssh.go:1284, (*sshSession).startNewRecording starts a fire-and-forget goroutine that can
outlive the test that triggered its creation. Among other things, it uses ss.logf, and may call it
after the test has already returned. Since we typically use (*testing.T).Logf as the logger,
this results in a data race and causes flaky tests.
Ideally, we should fix the root cause and/or use a goroutines.Tracker to wait for the goroutine
to complete. But with the release approaching, it's too risky to make such changes now.
As a workaround, we update the tests to use tstest.WhileTestRunningLogger, which logs to t.Logf
while the test is running and disables logging once the test finishes, avoiding the race.
While there, we also fix TestSSHAuthFlow not to use log.Printf.
Updates #15568
Updates #7707 (probably related)
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We previously kept these methods in local.go when we started moving node-specific state
from LocalBackend to nodeBackend, to make those changes easier to review. But it's time
to move them to node_backend.go.
Updates #cleanup
Updates #12614
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we extract the in-process LocalAPI client/server implementation from ipn/ipnserver/server_test.go
into a new ipntest package to be used in high‑level black‑box tests, such as those for the tailscale CLI.
Updates #15575
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we make the "user-dial-routes" behavior default on all platforms except for iOS and Android.
It can be disabled by setting the TS_DNS_FORWARD_USE_ROUTES envknob to 0 or false.
Updates #12027
Updates #13837
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We update profileManager to allow registering a single state (profile+prefs) change hook.
This is to invert the dependency between the profileManager and the LocalBackend, so that
instead of LocalBackend asking profileManager for the state, we can have profileManager
call LocalBackend when the state changes.
We also update feature.Hook with a new (*feature.Hook).GetOk method to avoid calling both
IsSet and Get.
Updates tailscale/corp#28014
Updates #12614
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This further minimizes the number of places where the profile manager updates the current profile and prefs.
We also document a scenario where an implicit profile switch can occur.
We should be able to address it after (partially?) inverting the dependency between
LocalBackend and profileManager, so that profileManager notifies LocalBackend
of profile changes instead of the other way around.
Updates tailscale/corp#28014
Updates #12614
Signed-off-by: Nick Khyl <nickk@tailscale.com>
These were likely added after everything else was updated to use tsd.NewSystem,
in a feature branch, and before it was merged back into main.
Updates #15160
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Both are populated from the current netmap's MagicDNSSuffix.
But building a full ipnstate.Status (with peers!) is expensive and unnecessary.
Updates #cleanup
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we enable extensions to track changes in the current prefs. These changes can result from a profile switch
or from the user or system modifying the current profile’s prefs. Since some extensions may want to distinguish between
the two events, while others may treat them similarly, we rename the existing profile-change callback to become
a profile-state-change callback and invoke it whenever the current profile or its preferences change. Extensions can still
use the sameNode parameter to distinguish between situations where the profile information, including its preferences,
has been updated but still represents the same tailnet node, and situations where a switch to a different profile has been made.
Having dedicated prefs-change callbacks is being considered, but currently seems redundant. A single profile-state-change callback
is easier to maintain. We’ll revisit the idea of adding a separate callback as we progress on extracting existing features from LocalBackend,
but the conversion to a profile-state-change callback is intended to be permanent.
Finally, we let extensions retrieve the current prefs or profile state (profile info + prefs) at any time using the new
CurrentProfileState and CurrentPrefs methods. We also simplify the NewControlClientCallback signature to exclude
profile prefs. It’s optional, and extensions can retrieve the current prefs themselves if needed.
Updates #12614
Updates tailscale/corp#27645
Updates tailscale/corp#26435
Updates tailscale/corp#27502
Signed-off-by: Nick Khyl <nickk@tailscale.com>
[G,S]etWindowLongPtrW are not available on 32-bit Windows, where [G,S]etWindowLongW should be used instead.
The initial revision of #14945 imported the win package for calling and other Win32 API functions, which exported
the correct API depending on the platform. However, the same logic wasn't implemented when we removed
the win package dependency in a later revision, resulting in panics on Windows 10 x86 (there's no 32-bit Windows 11).
In this PR, we update the ipn/desktop package to use either [G,S]etWindowLongPtrW or [G,S]etWindowLongW
depending on the platform.
Fixes#15684
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we add two methods to facilitate extension lookup by both extensions,
and non-extensions (e.g., PeerAPI or LocalAPI handlers):
- FindExtensionByName returns an extension with the specified name.
It can then be type asserted to a given type.
- FindMatchingExtension is like errors.As, but for extensions.
It returns the first extension that matches the target type (either a specific extension
or an interface).
Updates tailscale/corp#27645
Updates tailscale/corp#27502
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we refactor the LocalBackend extension system, moving from direct callbacks to a more organized extension host model.
Specifically, we:
- Extract interface and callback types used by packages extending LocalBackend functionality into a new ipn/ipnext package.
- Define ipnext.Host as a new interface that bridges extensions with LocalBackend.
It enables extensions to register callbacks and interact with LocalBackend in a concurrency-safe, well-defined, and controlled way.
- Move existing callback registration and invocation code from ipnlocal.LocalBackend into a new type called ipnlocal.ExtensionHost,
implementing ipnext.Host.
- Improve docs for existing types and methods while adding docs for the new interfaces.
- Add test coverage for both the extracted and the new code.
- Remove ipn/desktop.SessionManager from tsd.System since ipn/desktop is now self-contained.
- Update existing extensions (e.g., ipn/auditlog and ipn/desktop) to use the new interfaces where appropriate.
We're not introducing new callback and hook types (e.g., for ipn.Prefs changes) just yet, nor are we enhancing current callbacks,
such as by improving conflict resolution when more than one extension tries to influence profile selection via a background profile resolver.
These further improvements will be submitted separately.
Updates #12614
Updates tailscale/corp#27645
Updates tailscale/corp#26435
Updates tailscale/corp#18342
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Ultimately, we'd like to get rid of the concept of the "current user". It is only used on Windows,
but even then it doesn't work well in multi-user and enterprise/managed Windows environments.
In this PR, we update LocalBackend and profileManager to decouple them a bit more from this obsolete concept.
This is done in a preparation for extracting ipnlocal.Extension-related interfaces and types, and using them
to implement optional features like tailscale/corp#27645, instead of continuing growing the core ipnlocal logic.
Notably, we rename (*profileManager).SetCurrentUserAndProfile() to SwitchToProfile() and change its signature
to accept an ipn.LoginProfileView instead of an ipn.ProfileID and ipn.WindowsUserID. Since we're not removing
the "current user" completely just yet, the method sets the current user to the owner of the target profile.
We also update the profileResolver callback type, which is typically implemented by LocalBackend extensions,
to return an ipn.LoginProfileView instead of ipn.ProfileID and ipn.WindowsUserID.
Updates tailscale/corp#27645
Updates tailscale/corp#18342
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we update the Windows client updater to:
- Run msiexec with logging enabled and preserve the log file in %ProgramData%\Tailscale\Logs;
- Preserve the updater's own log file in the same location;
- Properly handle ERROR_SUCCESS_REBOOT_REQUIRED, ERROR_SUCCESS_REBOOT_INITIATED, and ERROR_INSTALL_ALREADY_RUNNING exit codes. The first two values indicate that installation
completed successfully and no further retries are needed. The last one means the Windows Installer
service is busy. Retrying immediately is likely to fail and may be risky; it could uninstall the current version
without successfully installing the new one, potentially leaving the user without Tailscale.
Updates tailscale/corp#27496
Updates tailscale#15554
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we update ipnlocal.LocalBackend to allow registering callbacks for control client creation
and profile changes. We also allow to register ipnauth.AuditLogFunc to be called when an auditable
action is attempted.
We then use all this to invert the dependency between the auditlog and ipnlocal packages and make
the auditlog functionality optional, where it only registers its callbacks via ipnlocal-provided hooks
when the auditlog package is imported.
We then underscore-import it when building tailscaled for Windows, and we'll explicitly
import it when building xcode/ipn-go-bridge for macOS. Since there's no default log-store
location for macOS, we'll also need to call auditlog.SetStoreFilePath to specify where
pending audit logs should be persisted.
Fixes#15394
Updates tailscale/corp#26435
Updates tailscale/corp#27012
Signed-off-by: Nick Khyl <nickk@tailscale.com>
LocalBackend transitions to ipn.NoState when switching to a different (or new) profile.
When this happens, we should unconfigure wgengine to clear routes, DNS configuration,
firewall rules that block all traffic except to the exit node, etc.
In this PR, we update (*LocalBackend).enterStateLockedOnEntry to do just that.
Fixes#15316
Updates tailscale/corp#23967
Signed-off-by: Nick Khyl <nickk@tailscale.com>
(*LocalBackend).setControlClientLocked() is called to both set and reset b.cc.
We shouldn't attempt to start the audit logger when b.cc is being reset (i.e., cc is nil).
However, it's fine to start the audit logger if b.cc implements auditlog.Transport, even if it's not a controlclient.Auto but a mock control client.
In this PR, we fix both issues and add an assertion that controlclient.Auto is an auditlog.Transport. This ensures a compile-time failure if controlclient.Auto ever stops being a valid transport due to future interface or implementation changes.
Updates tailscale/corp#26435
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Resetting LocalBackend's netmap without also unconfiguring wgengine to reset routes, DNS, and the killswitch
firewall rules may cause connectivity issues until a new netmap is received.
In some cases, such as when bootstrap DNS servers are inaccessible due to network restrictions or other reasons,
or if the control plane is experiencing issues, this can result in a complete loss of connectivity until the user disconnects
and reconnects to Tailscale.
As LocalBackend handles state resets in (*LocalBackend).resetForProfileChangeLockedOnEntry(), and this includes
resetting the netmap, resetting the current netmap in (*LocalBackend).Start() is not necessary.
Moreover, it's harmful if (*LocalBackend).Start() is called more than once for the same profile.
In this PR, we update resetForProfileChangeLockedOnEntry() to reset the packet filter and remove
the redundant resetting of the netmap and packet filter from Start(). We also update the state machine
tests and revise comments that became inaccurate due to previous test updates.
Updates tailscale/corp#27173
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we update the LocalBackend so that when the ReconnectAfter policy setting is configured
and a user disconnects Tailscale by setting WantRunning to false in the profile prefs, the LocalBackend
will now start a timer to set WantRunning back to true once the ReconnectAfter timer expires.
We also update the ADMX/ADML policy definitions to allow configuring this policy setting for Windows
via Group Policy and Intune.
Updates #14824
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We already reset the always-on override flag when switching profiles and in a few other cases.
In this PR, we update (*LocalBackend).Start() to reset it as well. This is necessary to support
scenarios where Start() is called explicitly, such as when the GUI starts or when tailscale up is used
with additional flags and passes prefs via ipn.Options in a call to Start() rather than via EditPrefs.
Additionally, we update it to apply policy settings to the current prefs, which is necessary
for properly overriding prefs specified in ipn.Options.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we enable the registration of LocalBackend extensions to exclude code specific to certain
platforms or environments. We then introduce desktopSessionsExt, which is included only in Windows builds
and only if the ts_omit_desktop_sessions tag is disabled for the build. This extension tracks desktop sessions
and switches to (or remains on) the appropriate profile when a user signs in or out, locks their screen,
or disconnects a remote session.
As desktopSessionsExt requires an ipn/desktop.SessionManager, we register it with tsd.System
for the tailscaled subprocess on Windows.
We also fix a bug in the sessionWatcher implementation where it attempts to close a nil channel on stop.
Updates #14823
Updates tailscale/corp#26247
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we further refactor LocalBackend and Unattended Mode to extract the logic that determines
which profile should be used at the time of the check, such as when a LocalAPI client connects or disconnects.
We then update (*LocalBackend).switchProfileLockedOnEntry to to switch to the profile returned by
(*LocalBackend).resolveBestProfileLocked() rather than to the caller-specified specified profile, and rename it
to switchToBestProfileLockedOnEntry.
This is done in preparation for updating (*LocalBackend).getBackgroundProfileIDLocked to support Always-On
mode by determining which profile to use based on which users, if any, are currently logged in and have an active
foreground desktop session.
Updates #14823
Updates tailscale/corp#26247
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This adds a new policy definition for the AlwaysOn.Enabled policy setting
as well as the AlwaysOn.OverrideWithReason sub-option.
Updates #14823
Updates tailscale/corp#26247
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Currently, we disconnect Tailscale and reset LocalBackend on Windows when the last LocalAPI client
disconnects, unless Unattended Mode is enabled for the current profile. And the implementation
is somewhat racy since the current profile could theoretically change after
(*ipnserver.Server).addActiveHTTPRequest checks (*LocalBackend).InServerMode() and before it calls
(*LocalBackend).SetCurrentUser(nil) (or, previously, (*LocalBackend).ResetForClientDisconnect).
Additionally, we might want to keep Tailscale running and connected while a user is logged in
rather than tying it to whether a LocalAPI client is connected (i.e., while the GUI is running),
even when Unattended Mode is disabled for a profile. This includes scenarios where the new
AlwaysOn mode is enabled, as well as when Tailscale is used on headless Windows editions,
such as Windows Server Core, where the GUI is not supported. It may also be desirable to switch
to the "background" profile when a user logs off from their device or implement other similar
features.
To facilitate these improvements, we move the logic from ipnserver.Server to ipnlocal.LocalBackend,
where it determines whether to keep Tailscale running when the current user disconnects.
We also update the logic that determines whether a connection should be allowed to better reflect
the fact that, currently, LocalAPI connections are not allowed unless:
- the current UID is "", meaning that either we are not on a multi-user system or Tailscale is idle;
- the LocalAPI client belongs to the current user (their UIDs are the same);
- the LocalAPI client is Local System (special case; Local System is always allowed).
Whether Unattended Mode is enabled only affects the error message returned to the Local API client
when the connection is denied.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This PR adds a new package, ipn/desktop, which provides a platform-agnostic
interface for enumerating desktop sessions and registering session callbacks.
Currently, it is implemented only for Windows.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
WindowsActor is an ipnauth.Actor implementation that represents a logged-in
Windows user by wrapping their Windows user token.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
The context carries additional information about the actor, such as the
request reason, and is canceled when the actor is done.
Additionally, we implement three new ipn.Actor types that wrap other actors
to modify their behavior:
- WithRequestReason, which adds a request reason to the actor;
- WithoutClose, which narrows the actor's interface to prevent it from being
closed;
- WithPolicyChecks, which adds policy checks to the actor's CheckProfileAccess
method.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
There’s (*LocalBackend).ResetForClientDisconnect, and there’s also (*LocalBackend).resetForProfileChangeLockedOnEntry.
Both methods essentially did the same thing but in slightly different ways. For example, resetForProfileChangeLockedOnEntry didn’t reset the control client until (*LocalBackend).Start() was called at the very end and didn’t reset the keyExpired flag, while ResetForClientDisconnect didn’t reinitialize TKA.
Since SetCurrentUser can be called with a nil argument to reset the currently connected user and internally calls resetForProfileChangeLockedOnEntry, we can remove ResetForClientDisconnect and let SetCurrentUser and resetForProfileChangeLockedOnEntry handle it.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Currently, profileManager filters profiles based on their creator/owner and the "current user"'s UID.
This causes DefaultUserProfileID(uid) to work incorrectly when the UID doesn't match the current user.
While we plan to remove the concept of the "current user" completely, we're not there yet.
In this PR, we fix DefaultUserProfileID by updating profileManager to allow checking profile access
for a given UID and modifying helper methods to accept UID as a parameter when returning
matching profiles.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Something I accidentally added in #14217.
It doesn't seem to impact Intune or the Administrative Templates MMC extension,
but it should still be fixed.
Updates #cleanup
Signed-off-by: Nick Khyl <nickk@tailscale.com>
With #14843 merged, (*localapi.Handler).servePrefs() now requires a non-nil actor,
and other places may soon require it as well.
In this PR, we update localapi.NewHandler with a new required parameter for the actor.
We then update tsnet to use ipnauth.Self.
We also rearrange the code in (*ipnserver.Server).serveHTTP() to pass the actor via Handler's
constructor instead of the field.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we move the code that checks the AlwaysOn policy from ipnserver.actor to ipnauth.
It is intended to be used by ipnauth.Actor implementations, and we temporarily make it exported
while these implementations reside in ipnserver and in corp. We'll unexport it later.
We also update [ipnauth.Actor.CheckProfileAccess] to accept an auditLogger, which is called
to write details about the action to the audit log when required by the policy, and update
LocalBackend.EditPrefsAs to use an auditLogger that writes to the regular backend log.
Updates tailscale/corp#26146
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we update client/tailscale.LocalClient to allow sending requests with an optional X-Tailscale-Reason
header. We then update ipn/ipnserver.{actor,Server} to retrieve this reason, if specified, and use it to determine
whether ipnauth.Disconnect is allowed when the AlwaysOn.OverrideWithReason policy setting is enabled.
For now, we log the reason, along with the profile and OS username, to the backend log.
Finally, we update LocalBackend to remember when a disconnect was permitted and do not reconnect automatically
unless the policy changes.
Updates tailscale/corp#26146
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Dots are not allowed in metric names and cause panics. Since we use dots in names like
AlwaysOn.OverrideWithReason, let's replace them with underscores. We don’t want to use
setting.KeyPathSeparator here just yet to make it fully hierarchical, but we will decide as
we progress on the (experimental) AlwaysOn.* policy settings.
tailscale/corp#26146
Signed-off-by: Nick Khyl <nickk@tailscale.com>
The AlwaysOn policy can be applied by (*LocalBackend).applySysPolicy, flipping WantRunning from false to true
before (*LocalBackend).Start() has been called for the first time and set a control client in b.cc. This results in a nil
pointer dereference and a panic when setPrefsLockedOnEntry applies the change and calls controlclient.Client.Login().
In this PR, we fix it by only doing a login if b.cc has been set.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we update LocalBackend to set WantRunning=true when applying policy settings
to the current profile's prefs, if the "always-on" mode is enabled.
We also implement a new (*LocalBackend).EditPrefsAs() method, which is like EditPrefs
but accepts an actor (e.g., a LocalAPI client's identity) that initiated the change.
If WantRunning is being set to false, the new EditPrefsAs method checks whether the actor
has ipnauth.Disconnect access to the profile and propagates an error if they do not.
Finally, we update (*ipnserver.actor).CheckProfileAccess to allow a disconnect
only if the "always-on" mode is not enabled by the AlwaysOn policy setting.
This is not a comprehensive solution to the "always-on" mode across platforms,
as instead of disconnecting a user could achieve the same effect by creating
a new empty profile, initiating a reauth, or by deleting the profile.
These are the things we should address in future PRs.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
The implementations define it to verify whether the actor has the requested access to a login profile.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Conventionally, we use views (e.g., ipn.PrefsView, tailcfg.NodeView, etc.) when
dealing with structs that shouldn't be mutated. However, ipn.LoginProfile has been
an exception so far, with a mix of passing and returning LoginProfile by reference
(allowing accidental mutations) and by value (which is wasteful, given its
current size of 192 bytes).
In this PR, we generate an ipn.LoginProfileView and use it instead of passing/returning
LoginProfiles by mutable reference or copying them when passing/returning by value.
Now, LoginProfiles can only be mutated by (*profileManager).setProfilePrefs.
Updates #14823
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In v1.78, we started acquiring the GP lock when reading policy settings. This led to a deadlock during
Tailscale installation via Group Policy Software Installation because the GP engine holds the write lock
for the duration of policy processing, which in turn waits for the installation to complete, which in turn
waits for the service to enter the running state.
In this PR, we prevent the acquisition of GP locks (aka EnterCriticalPolicySection) during service startup
and update the Windows Registry-based util/syspolicy/source.PlatformPolicyStore to handle this failure
gracefully. The GP lock is somewhat optional; it’s safe to read policy settings without it, but acquiring
the lock is recommended when reading multiple values to prevent the Group Policy engine from modifying
settings mid-read and to avoid inconsistent results.
Fixes#14416
Signed-off-by: Nick Khyl <nickk@tailscale.com>
If the server was in use at the time of the initial check, but disconnected and was removed
from the activeReqs map by the time we registered a waiter, the ready channel will never
be closed, resulting in a deadlock. To avoid this, we check whether the server is still busy
after registering the wait.
Fixes#14655
Signed-off-by: Nick Khyl <nickk@tailscale.com>
I made a last-minute change in #14626 to split a single loop that created 1_000 concurrent
connections into an inner and outer loop that create 100 concurrent connections 10 times.
This introduced a race because the last user's connection may still be active (from the server's
perspective) when a new outer iteration begins. Since every new client gets a unique ClientID,
but we reuse usernames and UIDs, the server may let a user in (as the UID matches, which is fine),
but the test might then fail due to a ClientID mismatch:
server_test.go:232: CurrentUser(Initial): got &{S-1-5-21-1-0-0-1001 User-4 <nil> Client-2 false false};
want &{S-1-5-21-1-0-0-1001 User-4 <nil> Client-114 false false}
In this PR, we update (*testIPNServer).blockWhileInUse to check whether the server is currently busy
and wait until it frees up. We then call blockWhileInUse at the end of each outer iteration so that the server
is always in a known idle state at the beginning of the inner loop. We also check that the current user
is not set when the server is idle.
Updates tailscale/corp#25804
Updates #14655 (found when working on it)
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This test verifies, among other things, that init functions cannot be deferred after (*DeferredFuncs).Do
has already been called and that all subsequent calls to (*DeferredFuncs).Defer return false.
However, the initial implementation of this check was racy: by the time (*DeferredFuncs).Do returned,
not all goroutines that successfully deferred an init function may have incremented the atomic variable
tracking the number of deferred functions. As a result, the variable's value could differ immediately
after (*DeferredFuncs).Do returned and after all goroutines had completed execution (i.e., after wg.Wait()).
In this PR, we replace the original racy check with a different one. Although this new check is also racy,
it can only produce false negatives. This means that if the test fails, it indicates an actual bug rather than
a flaky test.
Fixes#14039
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this commit, we add a failing test to verify that ipn/ipnserver.Server correctly
sets and unsets the current user when two different clients send requests concurrently
(A sends request, B sends request, A's request completes, B's request completes).
The expectation is that the user who wins the race becomes the current user
from the LocalBackend's perspective, remaining in this state until they disconnect,
after which a different user should be able to connect and use the LocalBackend.
We then fix the second of two bugs in (*Server).addActiveHTTPRequest, where a race
condition causes the LocalBackend's state to be reset after a new client connects,
instead of after the last active request of the previous client completes and the server
becomes idle.
Fixestailscale/corp#25804
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this commit, we add a failing test to verify that ipn/ipnserver.Server correctly
sets and unsets the current user when two different users connect sequentially
(A connects, A disconnects, B connects, B disconnects).
We then fix the test by updating (*ipn/ipnserver.Server).addActiveHTTPRequest
to avoid calling (*LocalBackend).ResetForClientDisconnect again after a new user
has connected and been set as the current user with (*LocalBackend).SetCurrentUser().
Since ipn/ipnserver.Server does not allow simultaneous connections from different
Windows users and relies on the LocalBackend's current user, and since we already
reset the LocalBackend's state by calling ResetForClientDisconnect when the last
active request completes (indicating the server is idle and can accept connections
from any Windows user), it is unnecessary to track the last connected user on the
ipnserver.Server side or call ResetForClientDisconnect again when the user changes.
Additionally, the second call to ResetForClientDisconnect occurs after the new user
has been set as the current user, resetting the correct state for the new user
instead of the old state of the now-disconnected user, causing issues.
Updates tailscale/corp#25804
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We update client/tailscale.LocalClient to allow specifying an optional Transport
(http.RoundTripper) for LocalAPI HTTP requests, and implement one that injects
an ipnauth.TestActor via request headers. We also add several functions and types
to make testing an ipn/ipnserver.Server possible (or at least easier).
We then use these updates to write basic tests for ipnserver.Server,
ensuring it works on non-Windows platforms and correctly sets and unsets
the LocalBackend's current user when a Windows user connects and disconnects.
We intentionally omit tests for switching between different OS users
and will add them in follow-up commits.
Updates tailscale/corp#25804
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In preparation for adding test coverage for ipn/ipnserver.Server, we update it
to use ipnauth.Actor instead of its concrete implementation where possible.
Updates tailscale/corp#25804
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This doesn't seem to have any immediate impact, but not allowing access via the IPv6 masquerade
address when an IPv4 masquerade address is also set seems like a bug.
Updates #cleanup
Updates #14570 (found when working on it)
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we add a generic views.ValuePointer type that can be used as a view for pointers
to basic types and struct types that do not require deep cloning and do not have corresponding
view types. Its Get/GetOk methods return stack-allocated shallow copies of the underlying value.
We then update the cmd/viewer codegen to produce getters that return either concrete views
when available or ValuePointer views when not, for pointer fields in generated view types.
This allows us to avoid unnecessary allocations compared to returning pointers to newly
allocated shallow copies.
Updates #14570
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We add a policy definition for the AllowedSuggestedExitNodes syspolicy setting, allowing admins
to configure a list of exit node IDs to be used as a pool for automatic suggested exit node selection.
We update definitions for policy settings configurable on both a per-user and per-machine basis,
such as UI customizations, to specify class="Both".
Lastly, we update the help text for existing policy definitions to include a link to the KB article
as the last line instead of in the first paragraph.
Updates #12687
Updates tailscale/corp#19681
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we update LocalBackend to rebuild the set of allowed suggested exit nodes whenever
the AllowedSuggestedExitNodes syspolicy setting changes. Additionally, we request a new suggested
exit node when this occurs, enabling its use if the ExitNodeID syspolicy setting is set to auto:any.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This PR removes the sync.Once wrapper around retrieving the MachineCertificateSubject policy
setting value, ensuring the most recent version is always used if it changes after the service starts.
Although this policy setting is used by a very limited number of customers, recent support escalations have highlighted issues caused by outdated or incorrect policy values being applied.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we update ipnlocal.NewLocalBackend to subscribe to policy change notifications
and reapply syspolicy settings to the current profile's ipn.Prefs whenever a change occurs.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This moves code that handles ExitNodeID/ExitNodeIP syspolicy settings
from (*LocalBackend).setExitNodeID to applySysPolicy.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This updates the syspolicy.LogSCMInteractions check to run at the time of an interaction,
just before logging a message, instead of during service startup. This ensures the most
recent policy setting is used if it has changed since the service started.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we move the syspolicy.FlushDNSOnSessionUnlock check from service startup
to when a session change notification is received. This ensures that the most recent policy
setting value is used if it has changed since the service started.
We also plan to handle session change notifications for unrelated reasons
and need to decouple notification subscriptions from DNS anyway.
Updates #12687
Updates tailscale/corp#18342
Signed-off-by: Nick Khyl <nickk@tailscale.com>
These delays determine how soon syspolicy change callbacks are invoked after a policy setting is updated
in a policy source. For tests, we shorten these delays to minimize unnecessary wait times. This adjustment
only affects tests that subscribe to policy change notifications and modify policy settings after they have
already been set. Initial policy settings are always available immediately without delay.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We have several places where LocalBackend instances are created for testing, but they are rarely shut down
when the tests that created them exit.
In this PR, we update newTestLocalBackend and similar functions to use testing.TB.Cleanup(lb.Shutdown)
to ensure LocalBackend instances are properly shut down during test cleanup.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we add the tailscale syspolicy command with two subcommands: list, which displays
policy settings, and reload, which forces a reload of those settings. We also update the LocalAPI
and LocalClient to facilitate these additions.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We make setting.Snapshot JSON-marshallable in preparation for returning it from the LocalAPI.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We add setting.RawValue, a new type that facilitates unmarshalling JSON numbers and arrays
as uint64 and []string (instead of float64 and []any) for policy setting values.
We then use it to make setting.RawItem JSON-marshallable and update the tests.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we implement (but do not use yet, pending #13727 review) a syspolicy/source.Store
that reads policy settings from environment variables. It converts a CamelCase setting.Key,
such as AuthKey or ExitNodeID, to a SCREAMING_SNAKE_CASE, TS_-prefixed environment
variable name, such as TS_AUTH_KEY and TS_EXIT_NODE_ID. It then looks up the variable
and attempts to parse it according to the expected value type. If the environment variable
is not set, the policy setting is considered not configured in this store (the syspolicy package
will still read it from other sources). Similarly, if the environment variable has an invalid value
for the setting type, it won't be used (though the reported/logged error will differ).
Updates #13193
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In this PR, we update the syspolicy package to utilize syspolicy/rsop under the hood,
and remove syspolicy.CachingHandler, syspolicy.windowsHandler and related code
which is no longer used.
We mark the syspolicy.Handler interface and RegisterHandler/SetHandlerForTest functions
as deprecated, but keep them temporarily until they are no longer used in other repos.
We also update the package to register setting definitions for all existing policy settings
and to register the Registry-based, Windows-specific policy stores when running on Windows.
Finally, we update existing internal and external tests to use the new API and add a few more
tests and benchmarks.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
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>
In this PR we add syspolicy/rsop package that facilitates policy source registration
and provides access to the resultant policy merged from all registered sources for a
given scope.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
If multiple upstream DNS servers are available, quad-100 sends requests to all of them
and forwards the first successful response, if any. If no successful responses are received,
it propagates the first failure from any of them.
This PR adds some test coverage for these scenarios.
Updates #13571
Signed-off-by: Nick Khyl <nickk@tailscale.com>
When an Exit Node is used, we create a WFP rule to block all inbound and outbound traffic,
along with several rules to permit specific types of traffic. Notably, we allow all inbound and
outbound traffic to and from LocalRoutes specified in wgengine/router.Config. The list of allowed
routes always includes routes for internal interfaces, such as loopback and virtual Hyper-V/WSL2
interfaces, and may also include LAN routes if the "Allow local network access" option is enabled.
However, these permitting rules do not allow link-local multicast on the corresponding interfaces.
This results in broken mDNS/LLMNR, and potentially other similar issues, whenever an exit node is used.
In this PR, we update (*wf.Firewall).UpdatePermittedRoutes() to create rules allowing outbound and
inbound link-local multicast traffic to and from the permitted IP ranges, partially resolving the mDNS/LLMNR
and *.local name resolution issue.
Since Windows does not attempt to send mDNS/LLMNR queries if a catch-all NRPT rule is present,
it is still necessary to disable the creation of that rule using the disable-local-dns-override-via-nrpt nodeAttr.
Updates #13571
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We already disable dynamic updates by setting DisableDynamicUpdate to 1 for the Tailscale interface.
However, this does not prevent non-dynamic DNS registration from happening when `ipconfig /registerdns`
runs and in similar scenarios. Notably, dns/windowsManager.SetDNS runs `ipconfig /registerdns`,
triggering DNS registration for all interfaces that do not explicitly disable it.
In this PR, we update dns/windowsManager.disableDynamicUpdates to also set RegistrationEnabled to 0.
Fixes#13411
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We no longer need this on Windows, and it was never required on other platforms.
It just results in more short-lived connections unless we use HTTP/2.
Updates tailscale/corp#18342
Signed-off-by: Nick Khyl <nickk@tailscale.com>
With the upcoming syspolicy changes, it's imperative that all syspolicy keys are defined in the syspolicy package
for proper registration. Otherwise, the corresponding policy settings will not be read.
This updates a couple of places where we still use string literals rather than syspolicy consts.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
This PR changes how LocalBackend handles interactive (initiated via StartLoginInteractive) and non-interactive (e.g., due to key expiration) logins,
and when it sends the authURL to the connected clients.
Specifically,
- When a user initiates an interactive login by clicking Log In in the GUI, the LocalAPI calls StartLoginInteractive.
If an authURL is available and hasn't expired, we immediately send it to all connected clients, suggesting them to open that URL in a browser.
Otherwise, we send a login request to the control plane and set a flag indicating that an interactive login is in progress.
- When LocalBackend receives an authURL from the control plane, we check if it differs from the previous one and whether an interactive login
is in progress. If either condition is true, we notify all connected clients with the new authURL and reset the interactive login flag.
We reset the auth URL and flags upon a successful authentication, when a different user logs in and when switching Tailscale login profiles.
Finally, we remove the redundant dedup logic added to WatchNotifications in #12096 and revert the tests to their original state to ensure that
calling StartLoginInteractive always produces BrowseToURL notifications, either immediately or when the authURL is received from the control plane.
Fixes#13296
Signed-off-by: Nick Khyl <nickk@tailscale.com>
We add package defining interfaces for policy stores, enabling creation of policy sources
and reading settings from them. It includes a Windows-specific PlatformPolicyStore for GP and MDM
policies stored in the Registry, and an in-memory TestStore for testing purposes.
We also include an internal package that tracks and reports policy usage metrics when a policy setting
is read from a store. Initially, it will be used only on Windows and Android, as macOS, iOS, and tvOS
report their own metrics. However, we plan to use it across all platforms eventually.
Updates #12687
Signed-off-by: Nick Khyl <nickk@tailscale.com>
The LocalBackend's state machine starts in NoState and soon transitions to NeedsLogin if there's no auto-start profile,
with the profileManager starting with a new empty profile. Notably, entering the NeedsLogin state blocks engine updates.
We expect the user to transition out of this state by logging in interactively, and we set WantRunning to true when
controlclient enters the StateAuthenticated state.
While our intention is correct, and completing an interactive login should set WantRunning to true, our assumption
that logging into the current Tailscale profile is the only way to transition out of the NeedsLogin state is not accurate.
Another common transition path includes an explicit profile switch (via LocalBackend.SwitchProfile) or an implicit switch
when a Windows user connects to the backend. This results in a bug where WantRunning is set to true even when it was
previously set to false, and the user expressed no intention of changing it.
A similar issue occurs when switching from (sic) a Tailnet that has seamlessRenewalEnabled, regardless of the current state
of the LocalBackend's state machine, and also results in unexpectedly set WantRunning. While this behavior is generally
undesired, it is also incorrect that it depends on the control knobs of the Tailnet we're switching from rather than
the Tailnet we're switching to. However, this issue needs to be addressed separately.
This PR updates LocalBackend.SetControlClientStatus to only set WantRunning to true in response to an interactive login
as indicated by a non-empty authURL.
Fixes#6668Fixes#11280
Updates #12756
Signed-off-by: Nick Khyl <nickk@tailscale.com>
In preparation for multi-user and unattended mode improvements, we are
refactoring and cleaning up `ipn/ipnlocal.profileManager`. The concept of the
"current user", which is only relevant on Windows, is being deprecated and will
soon be removed to allow more than one Windows user to connect and utilize
`LocalBackend` according to that user's access rights to the device and specific
Tailscale profiles.
We plan to pass the user's identity down to the `profileManager`, where it can
be used to determine the user's access rights to a given `LoginProfile`. While
the new permission model in `ipnauth` requires more work and is currently
blocked pending PR reviews, we are updating the `profileManager` to reduce its
reliance on the concept of a single OS user being connected to the backend at
the same time.
We extract the switching to the default Tailscale profile, which may also
trigger legacy profile migration, from `profileManager.SetCurrentUserID`. This
introduces `profileManager.DefaultUserProfileID`, which returns the default
profile ID for the current user, and `profileManager.SwitchToDefaultProfile`,
which is essentially a shorthand for `pm.SwitchProfile(pm.DefaultUserProfileID())`.
Both methods will eventually be updated to accept the user's identity and
utilize that user's default profile.
We make access checks more explicit by introducing the `profileManager.checkProfileAccess`
method. The current implementation continues to use `profileManager.currentUserID`
and `LoginProfile.LocalUserID` to determine whether access to a given profile
should be granted. This will be updated to utilize the `ipnauth` package and the
new permissions model once it's ready. We also expand access checks to be used
more widely in the `profileManager`, not just when switching or listing
profiles. This includes access checks in methods like `SetPrefs` and, most notably,
`DeleteProfile` and `DeleteAllProfiles`, preventing unprivileged Windows users
from deleting Tailscale profiles owned by other users on the same device,
including profiles owned by local admins.
We extract `profileManager.ProfilePrefs` and `profileManager.SetProfilePrefs`
methods that can be used to get and set preferences of a given `LoginProfile` if
`profileManager.checkProfileAccess` permits access to it.
We also update `profileManager.setUnattendedModeAsConfigured` to always enable
unattended mode on Windows if `Prefs.ForceDaemon` is true in the current
`LoginProfile`, even if `profileManager.currentUserID` is `""`. This facilitates
enabling unattended mode via `tailscale up --unattended` even if
`tailscale-ipn.exe` is not running, such as when a Group Policy or MDM-deployed
script runs at boot time, or when Tailscale is used on a Server Code or otherwise
headless Windows environments. See #12239, #2137, #3186 and
https://github.com/tailscale/tailscale/pull/6255#issuecomment-2016623838 for
details.
Fixes#12239
Updates tailscale/corp#18342
Updates #3186
Updates #2137
Signed-off-by: Nick Khyl <nickk@tailscale.com>
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>
Nick KhylandNick Khyl