9 Commits

Author SHA1 Message Date
Will Norris
3ec5be3f51 all: remove AUTHORS file and references to it
This file was never truly necessary and has never actually been used in
the history of Tailscale's open source releases.

A Brief History of AUTHORS files
---

The AUTHORS file was a pattern developed at Google, originally for
Chromium, then adopted by Go and a bunch of other projects. The problem
was that Chromium originally had a copyright line only recognizing
Google as the copyright holder. Because Google (and most open source
projects) do not require copyright assignemnt for contributions, each
contributor maintains their copyright. Some large corporate contributors
then tried to add their own name to the copyright line in the LICENSE
file or in file headers. This quickly becomes unwieldy, and puts a
tremendous burden on anyone building on top of Chromium, since the
license requires that they keep all copyright lines intact.

The compromise was to create an AUTHORS file that would list all of the
copyright holders. The LICENSE file and source file headers would then
include that list by reference, listing the copyright holder as "The
Chromium Authors".

This also become cumbersome to simply keep the file up to date with a
high rate of new contributors. Plus it's not always obvious who the
copyright holder is. Sometimes it is the individual making the
contribution, but many times it may be their employer. There is no way
for the proejct maintainer to know.

Eventually, Google changed their policy to no longer recommend trying to
keep the AUTHORS file up to date proactively, and instead to only add to
it when requested: https://opensource.google/docs/releasing/authors.
They are also clear that:

> Adding contributors to the AUTHORS file is entirely within the
> project's discretion and has no implications for copyright ownership.

It was primarily added to appease a small number of large contributors
that insisted that they be recognized as copyright holders (which was
entirely their right to do). But it's not truly necessary, and not even
the most accurate way of identifying contributors and/or copyright
holders.

In practice, we've never added anyone to our AUTHORS file. It only lists
Tailscale, so it's not really serving any purpose. It also causes
confusion because Tailscalars put the "Tailscale Inc & AUTHORS" header
in other open source repos which don't actually have an AUTHORS file, so
it's ambiguous what that means.

Instead, we just acknowledge that the contributors to Tailscale (whoever
they are) are copyright holders for their individual contributions. We
also have the benefit of using the DCO (developercertificate.org) which
provides some additional certification of their right to make the
contribution.

The source file changes were purely mechanical with:

    git ls-files | xargs sed -i -e 's/\(Tailscale Inc &\) AUTHORS/\1 contributors/g'

Updates #cleanup

Change-Id: Ia101a4a3005adb9118051b3416f5a64a4a45987d
Signed-off-by: Will Norris <will@tailscale.com>
2026-01-23 15:49:45 -08:00
Jonathan Nobels
52710945f5
control/controlclient, ipn: add client audit logging (#14950)
updates tailscale/corp#26435

Adds client support for sending audit logs to control via /machine/audit-log.
Specifically implements audit logging for user initiated disconnections.

This will require further work to optimize the peristant storage and exclusion
via build tags for mobile:
tailscale/corp#27011
tailscale/corp#27012

Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
2025-03-12 10:37:03 -04:00
Nick Khyl
e9e2bc5bd7 ipn/ipn{auth,server}: update ipnauth.Actor to carry a context
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>
2025-02-11 15:31:42 -06:00
Nick Khyl
00fe8845b1 ipn/{ipnauth,ipnlocal,ipnserver}: move the AlwaysOn policy check from ipnserver to ipnauth
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>
2025-02-04 14:36:01 -06:00
Nick Khyl
0a51bbc765 ipn/ipnauth,util/syspolicy: improve comments
Updates #cleanup
Updates #14823

Signed-off-by: Nick Khyl <nickk@tailscale.com>
2025-01-31 11:33:13 -06:00
Nick Khyl
081595de63 ipn/{ipnauth, ipnserver}: extend the ipnauth.Actor interface with a CheckProfileAccess method
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>
2025-01-31 10:22:20 -06:00
Nick Khyl
c3c4c96489 ipn/{ipnauth,ipnlocal,ipnserver}, client/tailscale: make ipnserver.Server testable
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>
2025-01-14 15:54:43 -06:00
Nick Khyl
874db2173b ipn/{ipnauth,ipnlocal,ipnserver}: send the auth URL to the user who started interactive login
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>
2024-10-18 15:10:02 -05:00
Nick Khyl
961ee321e8 ipn/{ipnauth,ipnlocal,ipnserver,localapi}: start baby step toward moving access checks from the localapi.Handler to the LocalBackend
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>
2024-08-28 13:49:58 -05:00