Online now requires a live session and an unexpired key, derived in one
place by Node.ShouldBeOnline so every writer agrees what online means.
Fixes#3470
Connect keeps 0.29's NodeOnlineFor peer patch; only the not-online branch
is new here. The updateChanges hunk is dropped: 0.29 has no caller for it.
(cherry picked from commit 80c863b15a)
Going offline changes nothing the policy reads, so the row write skips
the policy refresh and peers get only the offline patch.
Updates #3417
(cherry picked from commit dfe0d3f2e5)
A cancelled map request whose handler ran late could Connect after the
live session, steal the newest SessionEpoch, then exit without
disconnecting (stillConnected path); the live session's final
Disconnect was rejected as stale and the node stayed online forever
(relogin flake). Counted releases are order-independent, so overlapping
sessions cannot strand a node in either direction.
Don't send a full update when a subnet router goes up or down; the gated
policy change already recomputes peers and is a smaller payload.
Updates #3293
Connect and Disconnect appended change.PolicyChange() on every reconnect. PolicyChange sets RequiresRuntimePeerComputation, so the batcher rebuilt a full netmap (packet filters, SSH policy, peer serialization) for every connected node — O(N) per reconnect, O(N^2) on a restart storm. On a small VM this saturated CPU after the v0.28 -> v0.29 upgrade.
Emit it only when the node's online state changes what peers compute: subnet routers, relay targets, and via targets. An ordinary reconnect now sends just the lightweight online/offline peer patch. Relay and via targets still recompute, so peers drop a stale PeerRelay allocation when a relay goes offline.
Fixes#3293
Kristoffer Dalby
Kristoffer Dalby