Just make [relayManager] always handle it, there's no benefit to
checking bestAddr's.
Also, remove passing of disco.Pong to [relayManager] in
endpoint.handlePongConnLocked(), which is redundant with the callsite in
Conn.handleDiscoMessage(). Conn.handleDiscoMessage() already passes to
[relayManager] if the txID us not known to any [*endpoint].
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Changes to our src/address family can trigger blackholes.
This commit also adds a missing set of trustBestAddrUntil when setting
a UDP relay path as bestAddr.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Relay handshakes may now occur multiple times over the lifetime of a
relay server endpoint. Handshake messages now include a handshake
generation, which is client specified, as a means to trigger safe
challenge reset server-side.
Relay servers continue to enforce challenge values as single use. They
will only send a given value once, in reply to the first arriving bind
message for a handshake generation.
VNI has been added to the handshake messages, and we expect the outer
Geneve header value to match the sealed value upon reception.
Remote peer disco pub key is now also included in handshake messages,
and it must match the receiver's expectation for the remote,
participating party.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Premature cancellation was preventing the work from ever being cleaned
up in runLoop().
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
If we acted as the allocator we are responsible for signaling it to the
remote peer in a CallMeMaybeVia message over DERP.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
udprelay.Server is lazily initialized when the first request is received
over peerAPI. These early requests have a high chance of failure until
the first address discovery cycle has completed.
Return an ErrServerNotReady error until the first address discovery
cycle has completed, and plumb retry handling for this error all the
way back to the client in relayManager.
relayManager can now retry after a few seconds instead of waiting for
the next path discovery cycle, which could take another minute or
longer.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Any return underneath this select case must belong to a type switch case.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
It might complete, interrupting it reduces the chances of establishing a
relay path.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
This is simply for consistency with relayManagerInputEvent(), which
should be the sole launcher of runLoop().
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
relayManager can now hand endpoint a relay epAddr for it to consider
as bestAddr.
endpoint and Conn disco ping/pong handling are now VNI-aware.
Updates tailscale/corp#27502
Updates tailscale/corp#29422
Signed-off-by: Jordan Whited <jordan@tailscale.com>
This commit adds a new type to magicsock, epAddr, which largely ends up
replacing netip.AddrPort in packet I/O paths throughout, enabling
Geneve encapsulation over UDP awareness.
The conn.ReceiveFunc for UDP has been revamped to fix and more clearly
distinguish the different classes of packets we expect to receive: naked
STUN binding messages, naked disco, naked WireGuard, Geneve-encapsulated
disco, and Geneve-encapsulated WireGuard.
Prior to this commit, STUN matching logic in the RX path could swallow
a naked WireGuard packet if the keypair index, which is randomly
generated, happened to overlap with a subset of the STUN magic cookie.
Updates tailscale/corp#27502
Updates tailscale/corp#29326
Signed-off-by: Jordan Whited <jordan@tailscale.com>
relayManager is responsible for disco ping/pong probing of relay
endpoints once a handshake is complete.
Future work will enable relayManager to set a relay endpoint as the best
UDP path on an endpoint if appropriate.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
This type improves code clarity and reduces the chance of heap alloc as
we pass it as a non-pointer. VNI being a 3-byte value enables us to
track set vs unset via the reserved/unused byte.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
CallMeMaybeVia reception and endpoint allocation have been collapsed to
a single event channel. discoInfo caching for active relay handshakes
is now implemented.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
The event loop removes the need for growing locking complexities and
synchronization. Now we simply use channels. The event loop only runs
while there is active work to do.
relayManager remains no-op inside magicsock for the time being.
endpoints are never 'relayCapable' and therefore endpoint & Conn will
not feed CallMeMaybeVia or allocation events into it.
A number of relayManager events remain unimplemented, e.g.
CallMeMaybeVia reception and relay handshaking.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
relayManager will eventually be responsible for handling the allocation
and handshaking of UDP relay server endpoints.
relay servers are endpoint-independent, and Conn must already maintain
handshake state for all endpoints. This justifies a new data structure
to fill these roles.
Updates tailscale/corp#27502
Signed-off-by: Jordan Whited <jordan@tailscale.com>
Jordan Whited