The hook fires when a flow is removed for any reason (LRU capacity eviction,
tuple-collision displacement, or idle-time expiry). The hook is invoked
exactly once per flow, after the flow table mutex is released, so callbacks
may safely acquire other locks.
We rename the IPMapper interface to Conn25Datapath, and add
ClientFlowCreated/ClientFlowRemoved methods so *Conn25 can keep client-side
address assignments alive while traffic is in flight. Those methods are
currently stubbed for future work.
Connector flows do not currently call these methods.
Updates tailscale/corp#38630
Updates tailscale/corp#43180
Signed-off-by: Michael Ben-Ami <mzb@tailscale.com>
6f281ccbcd