Brad Fitzpatrick 3e493e0417 wgengine: fix lazy wireguard config bug on sent packet minute+ later
A comparison operator was backwards.

The bad case went:

* device A send packet to B at t=1s
* B gets added to A's wireguard config
* B gets packet

(5 minutes pass)

* some other activity happens, causing B to expire
  to be removed from A's network map, since it's
  been over 5 minutes since sent or received activity
* device A sends packet to B at t=5m1s
* normally, B would get added back, but the old send
  time was not zero (we sent earlier!) and the time
  comparison was backwards, so we never regenerated
  the wireguard config.

This also refactors the code for legibility and moves constants up
top, with comments.
2020-07-31 12:56:37 -07:00
..