Introduces IConnectionFilter and the ConnectionFilters registry: one seam the
accept path consults per inbound socket, so core no longer has to know where a
gate's data comes from. The registry is a plain array walked by an indexed loop,
so the hot path has no enumerator, no closure and no allocation; an interface
dispatch is noise next to the accept syscall. Filters register during the
Configure sweep, cheapest first, and the first denial short-circuits.
A filter that throws on the accept path is unregistered and the connection
fails open. A filter that faults once faults for every subsequent connection,
so leaving it registered would mean an exception and a log line per accept --
exactly the amplification an attacker wants -- and a broken filter must not be
able to deny every connection either.
With that seam in place the whole file blocklist moves to UOContent: it is
policy (which feeds, when to promote, what to report) built on an external file
format with an external producer, and core does not need any of it. Firewall
stays in core -- it is long-standing public API, it is what an admin reaches for
manually, and a shard running without UOContent still has to be able to block an
address -- but it now reaches the accept path through the same registry via a
small adapter, so the two remain separate implementations rather than one
conflated store.
Blocklist policy moves out of bans.json into a UOContent Configuration/
blocklist.json, next to crowdsec.json. bans.json keeps only what core decides:
reportRateLimitTrips and autoBanDuration.
Cleanups found while moving the code:
- BanChannel.Stop() persisted the Firewall. A contribution coordinator has no
business saving an enforcement store; that is now the firewall filter's Stop.
- BlocklistGate.Evaluate took a `whitelisted` flag that was hardcoded false at
its only call site, and no whitelist concept exists anywhere in core. Dropped.
- FileBlocklist was a static holding a snapshot and a promote-guard, which
forced its tests onto the sequential collection and a LoadForTesting reset
hook. It is now an instance, so each test owns its own state and they run in
parallel. BlocklistGate folds into it: the pure decision survives as an
internal Evaluate, which is all the separate type ever provided.
- The promote-guard sweep timer was registered from NetState.Configure, two
files from the guard it swept, and ran even with the blocklist disabled. It
now starts with the filter that owns it.
Core sheds ~570 source and ~340 test lines for ~90 of seam. 1344 tests pass.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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