Block incoming connection requests which are not allowed by current access lists

[soffokl]

Closes #878

[vkuznecovas]

I'm not sure. I think the implementation should account for the fact that most of the service providers will be running 24/7 for months at a time with no service restarts. Therefore I think we should periodically update the list of allowed ID's and:

a) don't let anyone who's not whitelisted access our service
b) remove active sessions from ID's that are not whitelisted(since the list might change)

[vkuznecovas]

the else is redundant

[soffokl]

It's not.
It's else if just for a smaller number of lines instead of two if. :)

[donce]

I'm not sure. I think the implementation should account for the fact that most of the service providers will be running 24/7 for months at a time with no service restarts. Therefore I think we should periodically update the list of allowed ID's and:

a) don't let anyone who's not whitelisted access our service
b) remove active sessions from ID's that are not whitelisted(since the list might change)

You're totally right - this is what we discussed in grooming meeting before starting implementing, and we agreed (together with business at TL) that we need to do this, but it's not a priority. For starters, it's enough to use the rules which are fetched once.

Added a task in https://github.com/mysteriumnetwork/mysterium-vpn/issues/456 not to forget about this thing :)

[donce]

Let's merge this PR to start testing. We can work on periodic fetching and forbidden identities kicking in parallel.

[donce]

CI is feiling