Via grants steer routes to specific nodes per viewer. Until now,
all clients saw the same routes for each peer because route
assembly was viewer-independent. This implements per-viewer route
visibility so that via-designated peers serve routes only to
matching viewers, while non-designated peers have those routes
withdrawn.
Add ViaRouteResult type (Include/Exclude prefix lists) and
ViaRoutesForPeer to the PolicyManager interface. The v2
implementation iterates via grants, resolves sources against the
viewer, matches destinations against the peer's advertised routes
(both subnet and exit), and categorizes prefixes by whether the
peer has the via tag.
Add RoutesForPeer to State which composes global primary election,
via Include/Exclude filtering, exit routes, and ACL reduction.
When no via grants exist, it falls back to existing behavior.
Update the mapper to call RoutesForPeer per-peer instead of using
a single route function for all peers. The route function now
returns all routes (subnet + exit), and TailNode filters exit
routes out of the PrimaryRoutes field for HA tracking.
Updates #2180
This commit replaces the ChangeSet with a simpler bool based
change model that can be directly used in the map builder to
build the appropriate map response based on the change that
has occured. Previously, we fell back to sending full maps
for a lot of changes as that was consider "the safe" thing to
do to ensure no updates were missed.
This was slightly problematic as a node that already has a list
of peers will only do full replacement of the peers if the list
is non-empty, meaning that it was not possible to remove all
nodes (if for example policy changed).
Now we will keep track of last seen nodes, so we can send remove
ids, but also we are much smarter on how we send smaller, partial
maps when needed.
Fixes#2389
Signed-off-by: Kristoffer Dalby <kristoffer@dalby.cc>
This PR investigates, adds tests and aims to correctly implement Tailscale's model for how Tags should be accepted, assigned and used to identify nodes in the Tailscale access and ownership model.
When evaluating in Headscale's policy, Tags are now only checked against a nodes "tags" list, which defines the source of truth for all tags for a given node. This simplifies the code for dealing with tags greatly, and should help us have less access bugs related to nodes belonging to tags or users.
A node can either be owned by a user, or a tag.
Next, to ensure the tags list on the node is correctly implemented, we first add tests for every registration scenario and combination of user, pre auth key and pre auth key with tags with the same registration expectation as observed by trying them all with the Tailscale control server. This should ensure that we implement the correct behaviour and that it does not change or break over time.
Lastly, the missing parts of the auth has been added, or changed in the cases where it was wrong. This has in large parts allowed us to delete and simplify a lot of code.
Now, tags can only be changed when a node authenticates or if set via the CLI/API. Tags can only be fully overwritten/replaced and any use of either auth or CLI will replace the current set if different.
A user owned device can be converted to a tagged device, but it cannot be changed back. A tagged device can never remove the last tag either, it has to have a minimum of one.
Initial work on a nodestore which stores all of the nodes
and their relations in memory with relationship for peers
precalculated.
It is a copy-on-write structure, replacing the "snapshot"
when a change to the structure occurs. It is optimised for reads,
and while batches are not fast, they are grouped together
to do less of the expensive peer calculation if there are many
changes rapidly.
Writes will block until commited, while reads are never
blocked.
Signed-off-by: Kristoffer Dalby <kristoffer@tailscale.com>
