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>
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>
Jordan Whited