We extract checkEditPrefsAccessLocked, adjustEditPrefsLocked, and onEditPrefsLocked from the EditPrefs
execution path, defining when each step is performed and what behavior is allowed at each stage.
Currently, this is primarily used to support Always On mode, to handle the Exit Node enablement toggle,
and to report prefs edit metrics.
We then use it to enforce Exit Node policy settings by preventing users from setting an exit node
and making EditPrefs return an error when an exit node is restricted by policy. This enforcement is also
extended to the Exit Node toggle.
These changes prepare for supporting Exit Node overrides when permitted by policy and preventing logout
while Always On mode is enabled.
In the future, implementation of these methods can be delegated to ipnext extensions via the feature hooks.
Updates tailscale/corp#29969
Updates tailscale/corp#26249
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>
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>
