When an event bus is configured publish an event each time a new port mapping
is updated. Publication is unconditional and occurs prior to calling any
callback that is registered. For now, the callback is still fired in a separate
goroutine as before -- later, those callbacks should become subscriptions to
the published event.
For now, the event type is defined as a new type here in the package. We will
want to move it to a more central package when there are subscribers. The event
wrapper is effectively a subset of the data exported by the internal mapping
interface, but on a concrete struct so the bus plumbing can inspect it.
Updates #15160
Change-Id: I951f212429ac791223af8d75b6eb39a0d2a0053a
Signed-off-by: M. J. Fromberger <fromberger@tailscale.com>
Previously, we would select the first WANIPConnection2 (and related)
client from the root device, without any additional checks. However,
some routers expose multiple UPnP devices in various states, and simply
picking the first available one can result in attempting to perform a
portmap with a device that isn't functional.
Instead, mimic what the miniupnpc code does, and prefer devices that are
(a) reporting as Connected, and (b) have a valid external IP address.
For our use-case, we additionally prefer devices that have an external
IP address that's a public address, to increase the likelihood that we
can obtain a direct connection from peers.
Finally, we split out fetching the root device (getUPnPRootDevice) from
selecting the best service within that root device (selectBestService),
and add some extensive tests for various UPnP server behaviours.
RELNOTE=Improve UPnP portmapping when multiple UPnP services exist
Updates #8364
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I71795cd80be6214dfcef0fe83115a5e3fe4b8753
