Review of the ADR 0105 build (hq ADR 0105). Four things it got wrong and one
path it lacked:
- A predecessor spoke's tunnel names one peer, the hub, routed the whole
range; recording refused it and the whole enrolment failed. Range-routed
peers are skipped now — only the hub's peers are ever carried.
- The range and the carried peers were conditions on the node being adopted,
so converging the hub would have renumbered the mesh and dropped the peers
still reaching it. They are facts of the tunnel record now, mode aside; the
takeover alone is declared to an adopted node. Converging the hub is refused
while a carried peer has not enrolled, naming it.
- A push composed a takeover for a hub whose address or endpoint disagreed
with the tunnel, which would have the host stop the found interface and
raise the mesh's where no peer listens. The graph refuses to compose it,
naming both and the placement that fixes it.
- The host's account said taken or not; "found down and the mesh's not up"
read as not taken. Three states now, and an account on every takeover.
- A hub that enrolled before this feature holds a key of its own, and
re-enrolling would rotate every key the mesh sealed credentials to. A node
now rekeys in a report, signed with its identity key over the key it
leaves, the key it takes and the tunnel; the mesh verifies against the live
key, refuses a stale or foreign proof, records key and tunnel, and moves a
hub to the tunnel's address. `overlay show` names the path for a hub that
found no tunnel.
Also: a carried IPv6 peer is routed /128, and identity.ForTest exists so the
link can be tested against a real identity store.
jschoubben
4566c5c9aa