This enables the following linters
- typecheck
- unused
- staticcheck
- bidichk
- durationcheck
- exportloopref
- gosec
WIth a few exceptions.
- We use a deprecated protobuf in trezor. I didn't want to mess with that, since I cannot meaningfully test any changes there.
- The deprecated TypeMux is used in a few places still, so the warning for it is silenced for now.
- Using string type in context.WithValue is apparently wrong, one should use a custom type, to prevent collisions between different places in the hierarchy of callers. That should be fixed at some point, but may require some attention.
- The warnings for using weak random generator are squashed, since we use a lot of random without need for cryptographic guarantees.
This adds a lock around requests because some routers can't handle
concurrent requests. Requests are also rate-limited.
The Map function request a new mapping exactly when the map timeout
occurs instead of 5 minutes earlier. This should prevent duplicate mappings.
I have verified that UPnP and NAT-PMP work against an older version of
the MiniUPnP daemon running on pfSense. This code is kind of hard to
test automatically.
