A program bans an address (every port, or a protocol's ports) for a
time; the ban list says what it is kept from: the firewall, some hosts
behind it, or everything. Bans drop ahead of every rule, close the
address's connections, group IPv6 by /64, are kept in the database
across restarts and audited. Never banned: the inside, the firewall's
own addresses, the caller, the list's never. bans grant (bans:write:LIST),
hc banlist/bans/ban/unban, Traffic -> Bans, a fail2ban action in contrib/,
and failed logins and refused tokens logged for Guard and fail2ban.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
model.QuotaCarry says what becomes of a quota's use when its rule
changes how it counts; the firewall's apply follows it, comparing with
the rules in force: per address to a total starts at the addresses' sum,
wider groups add up their addresses, and what can't be carried (a total
to per address, per source to per destination, finer groups) starts
again, with the engine warning quota_restarts on that change. Before,
per source to per destination kept the sources' use as destinations',
and regrouping left old entries behind.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- Connections: the kernel's tracked connections, read and closed over
ctnetlink (internal/conntrack, raw netlink like the drop log), with
their NAT and TCP state; closing one makes the rules check its next
packet again (GET /connections, POST /connections/close; hc
connections; Traffic → Connections).
- Rules can check every packet (every_packet, --every-packet): before
established connections are accepted, so a drop or reject also stops
connections already open. They can't accept.
- A packet tracer (internal/trace): a table of its own, inet
housecarl-trace, marks the packets a filter picks, `nft monitor trace`
reports every rule and policy they meet in every table, and the tracer
names what accepted or dropped them, Housecarl's rules by name (POST,
GET, DELETE /trace; hc trace; Traffic → Trace). One trace at a time,
at most 200 packets and 20 a second; the table goes when it ends.
e2e: 157 checks, among them an upload a normal block doesn't stop and an
every-packet one does, and a trace naming the blocking rule.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Changesets, as in Jarl: configuration changes are operations that can be
staged in a changeset, checked as they are added (validation and nft -c),
reviewed with the diff of the ruleset, and applied together as one
history entry, then on probation like any change made over the network.
The web UI collects edits for review by default (pending rows, a bar with
Review and Apply now, a Changes page, a switch for live edits); hc stages
with -C ID or HOUSECARL_CHANGESET (checked like JARL_CHANGESET) and has
hc changeset create/list/show/diff/apply/discard/remove. Undo, import and
takeover refuse a changeset. --dry-run shows the ruleset's diff.
Bandwidth and quotas: rate limits in bytes, per source or destination;
quotas per rule or per address that reset daily, weekly, monthly on a
day, or by hand, with their usage carried across reloads, saved for
reboots, shown by hc quotas and on the rules page, and reset with hc rule
reset-quota. Rules that count traffic are checked before established
connections are accepted (so they see every packet) and can't accept.
Per-address limits group IPv6 by /64 by default (--group-v4/-v6).
Per-source rate meters use update. The importer turns meters, byte rates
and quotas into these fields.
The examples in the web UI, hc's help and the docs use documentation
addresses and generic names instead of the maintainer's network.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Zones, address sets (IPv4 and IPv6 mixed, dynamic sets with timeouts) and
services, ordered rules in the early, input, forward and output chains,
port forwards with hairpin NAT and IPv6 pinholes, source NAT, redirects,
and switchable built-ins (loopback, conntrack, ICMPv6, antispoofing, MSS
clamping, DHCPv6 client, flowtable). Every change is validated, checked
with nft -c and applied in one transaction to Housecarl's own table,
inet housecarl; changes made over the network roll back unless
confirmed, and the confirmed ruleset is loaded at boot by
housecarl-ruleset.service. An empty configuration applies nothing.
Also: hit counters and the drop log (nflog), 'hc import' of an existing
nftables ruleset and 'hc takeover', the hc CLI, the REST API and the web
UI, users, scoped tokens (sets:write:NAME), the audit log, the web UI's
certificate through Jarl, Debian packages, docs, unit tests with real
nft 1.1.3, and an e2e test with real traffic (71 checks).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
abrown38andClaude Opus 5.5