Archived
jschoubben
092109debc
The machine that most needed a firewall was the one that could not have one. A hub is dialled by every node at other sites and needs its port open; a machine that is not a hub dials out and needs nothing open. They are the same module, and `listens` in a manifest is one answer for every machine that runs it — so the machine a static answer gets wrong is the one facing the public internet. A generator can now say what it opens, in a second interface rather than a method on every generator: most have nothing to say here, and requiring an empty method of each would be a cost paid everywhere for one caller. The port is the one in the endpoint, which is where the interface takes its ListenPort from. One source, so a rule set cannot open a port the interface is not on. Open to everywhere and deliberately: a node at another site is not on the private network until this port lets it on, so restricting it to the mesh would be a rule that can never be satisfied by the thing it exists for. And a generator that cannot say is refused rather than read as silence. Closing a port on the evidence of a failure to look is how a machine is severed by a fault somewhere else — and the machine it would sever is the hub, whose only route to being fixed is the network it just closed.