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>
Previously, we were registering TCP and UDP connections in the same map,
which could result in erroneously removing a mapping if one of the two
connections completes while the other one is still active.
Add a "proto string" argument to these functions to avoid this.
Additionally, take the "proto" argument in LocalAPI, and plumb that
through from the CLI and add a new LocalClient method.
Updates tailscale/corp#20600
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I35d5efaefdfbf4721e315b8ca123f0c8af9125fb
On unix systems, the check involves executing sudo, which is slow.
Instead of doing it for every incoming request, move the logic into
localapi serveServeConfig handler and do it as needed.
Updates tailscale/corp#15405
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
For an operator user, require them to be able to `sudo tailscale` to use
`tailscale serve`. This is similar to the Windows elevated token check.
Updates tailscale/corp#15405
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
Clients optionally request private key filtering. If they don't, we
should require Write access for the user.
Updates https://github.com/tailscale/corp/issues/15506
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
For a serve config with a path handler, ensure the caller is a local administrator on Windows.
updates #8489
Signed-off-by: Tyler Smalley <tyler@tailscale.com>
It would end up resetting whatever hostinfo we had constructed
and leave the backend statemachine in a broken state.
This fixes that by storing the PushDeviceToken on the LocalBackend
and populating it on Hostinfo before passing it to controlclient.
Updates tailscale/corp#8940
Updates tailscale/corp#15367
Signed-off-by: Maisem Ali <maisem@tailscale.com>
The whois handler was documented as taking IP (e.g. 100.101.102.103)
or IP:port (e.g. usermode 127.0.0.1:1234) but that got broken at some point
and we started requiring a port always. Fix that.
Also, found in the process of adding tests: fix the CapMap lookup in
userspace mode (it was always returning the caps of 127.0.0.1 in
userspace mode). Fix and test that too.
Updates #9714
Change-Id: Ie9a59744286522fa91c4b70ebe89a1e94dbded26
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This is for use by LocalAPI clients written in other languages that
don't appear to be able to talk HTTP over a socket (e.g.
java.net.http.HttpClient).
Signed-off-by: David Crawshaw <crawshaw@tailscale.com>
