notify of connection at earliest step, pause, proceed

[mcfnord]

In the server, I have added a systemd log message for a new connection in the earliest connection steps, followed by a pause. The quarter-second pause gives a log subscriber the opportunity to intervene before the connection is finalized.

Before I deploy this to more servers, I wonder if anyone has any insights about how this approach might fail, or how it could be done better.

I will use this modification along with a Python script to protect against bot and social engineering attacks from networks known for hosting these, which will also block a very small amount of legitimate traffic originating from the Philippines. I will keep an eye out for scenarios where VPNs bypass bad routing for legitimate users, and I'll avoid deploying this modified server near them. If others use this patch, these network insights can be shared.

I'm also making a PR to see if it triggers a build that I/anyone can use. A PR will also help me patch the next release when it's available.