UPnP is now used to request a port on the NAT be forwarded to the local machine.
This obviously only works for NATs that support UPnP, and thus is not a panacea
for all NAT-related connectivity issues.
Notable hacks in this patch include a transmit/receive UDP socket pair to work
around current protocol limitations whereby the full node assumes its peer can
receive on the same UDP port it transmitted from.
pnet_transport takes a long time to build. It's been especially
painful from within a docker container for reasons I don't care
to understand. pnet_datalink is the only part of pnet we're using
so booting the rest.
Refactored TVU, into stages
* blob fetch stage for blobs
* window stage for maintaining the blob window
* pulled out NCP out of the TVU so they can be separate units
TVU is now just the fetch -> window -> request and bank processing
We added them thinking it'd be a good stepping stone towards an
asynchronous thin client, but it's used inconsistently and where
it used, the function is still synchronous, which is just confusing.
The terms Stub and Skel come from OMG IDL and only made sense while
the Stub was acting as an RPC client for the the Accountant object.
Nowadays, the Stub interface looks nothing like the Accountant and
meanwhile we've recognized the multithreaded implementation is more
reminiscent of a pipelined CPU. Thus, we finally bite the bullet and
rename our modules.
AccountantSkel -> Tpu
AccountantStub -> ThinClient
Up next will be moving much of the TPU code into separate modules,
each representing a stage of the pipeline. The interface of each
will follow the precedent set by the Historian object.