Move PeerAclReloader onto the Reloadable trait: its ACL snapshot is now
published through an arc_swap::ArcSwap so the authorization hot path reads
it without locking, and the former check_reload becomes the trait's
reload(). The node tick calls self.peer_acl.reload().await.
Wire the host map into the tick as well. The host map snapshot was
previously taken once at construction and never polled; it now hot-reloads
on /etc/fips/hosts mtime changes once per tick, alongside the ACL, so
hostname display reflects edits without a restart.
The path_mtu_lookup cache (event-driven, populated from observed traffic)
and the nostr_discovery subsystem (an async spawned task) are deliberately
left off the trait: neither reloads from a backing file, so a no-op reload()
would be misleading. The rationale is documented on the trait module.
The host map and the ACL's embedded alias reloader still stat /etc/fips/hosts
independently each tick. A single small-file stat per tick is cheap, so the
duplicate is left in place; sharing one mtime observation between the two is
a possible future cleanup.
Tests: a node-level test exercises the host-map tick reload end to end
through peer_display_name; the ACL reloader tests are updated to drive the
async reload().
Implement TCP Wrappers-style peer access control using
/etc/fips/peers.allow and /etc/fips/peers.deny files. Evaluation
order: allow overrides deny, default permit when no files exist.
Three enforcement points: outbound connect (before dialing), inbound
handshake (msg1 receipt, after restart/rekey classification), and
outbound handshake completion (msg2, before peer promotion). Files
support npub, hex pubkey, host alias, and ALL wildcard entries with
automatic mtime-based reload.
Adds fipsctl acl show query, 954-line acl module with unit tests,
and a 6-node Docker integration harness (testing/acl-allowlist/)
exercising insider, outsider, and allowed-remote scenarios. CI
matrix entry included.
Closes#50
Co-authored-by: Johnathan Corgan <johnathan@corganlabs.com>