Packet 1 is always a stage 1 handshake and packet 2 is always stage 2.
Normal packets don't start flowing until the message counter is 3 or
higher.
Currently we only receive either packet 1 or 2 depending on if
we are the initiator or responder for the handshake, so we end up
marking one of these as "lost". We should mark these packets as "seen"
when we are the one sending them, since we don't expect to see them from
the other side.
* enforce the use of goimports
Instead of enforcing `gofmt`, enforce `goimports`, which also asserts
a separate section for non-builtin packages.
* run `goimports` everywhere
* exclude generated .pb.go files
This change add more metrics around "meta" (non "message" type packets).
For lighthouse packets, we also record statistics around the specific
lighthouse meta type.
We don't keep statistics for the "message" type so that we don't slow
down the fast path (and you can just look at metrics on the tun
interface to find that information).
This change adds a new helper, `(*HostInfo).logger()`, that starts a new
logrus.Entry with `vpnIp` and `certName`. We don't use the helper inside
of handshake_ix though since the certificate has not been attached to
the HostInfo yet.
Fixes: #84
