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Housecarl v0.1.0-rc.7 Pre-release
released this
2026-10-19 22:32:07 +01:00 | -16 commits to main since this releaseThe first version of Housecarl, a firewall manager for nftables, built
the way Jarl and Steward are.Added
- Zones, address sets and services: interfaces grouped by what they
connect to (wildcards likeincusbr*; external zones face the
internet); sets of IPv4 and IPv6 addresses, prefixes and ranges, mixed;
ports and ICMP types by name, with twenty built in (docs/rules.md). - Rules in four chains (input, forward, output, and early, before
connection tracking), in order, matching by zone, address, service,
family, connection state and status, days and hours, a rate (also per
source address), and a connection count; accept, drop, reject (ICMP or
TCP reset) or log. Raw nftables rules for the rest. - IPv4 and IPv6 together: one rule becomes the nftables rules each
family needs. - NAT: port forwards as one object (DNAT, the forward accept, hairpin
NAT, and optionally an IPv6 pinhole to a host's own port); source NAT
(masquerade or an address; NAT66 on request); redirects to the firewall
(docs/nat.md). - Built-ins, each switchable: loopback, established connections,
invalid packets, ICMPv6 (RFC 4890), ping from internal zones, DHCPv6
client replies, antispoofing with your own prefixes, MSS clamping, and
a flowtable fast path. - Changesets, as in Jarl: changes staged to be reviewed and applied
together, as one history entry. Each is checked as it is staged; the
review shows the problems, nftables' check and the diff of the ruleset.
The web UI collects edits as pending changes by default (pending rows,
a bar with Review and Apply now, a Changes page), with a switch for live
edits, and Undo in History is staged like any edit; hc stages with
-C IDorHOUSECARL_CHANGESET, and hashc changeset create/list/show/diff/apply/discard/remove. An applied
changeset is on probation like any change.--dry-runshows the
ruleset's diff too (docs/design.md, docs/cli.md). - Bandwidth limits and quotas: rate limits in bytes (
--limit 20mbytes/second,over,per-source), per source or per destination;
quotas, an allowance of traffic per rule or per address, reset daily,
weekly, monthly on a chosen day, or by hand, kept across changes,
restarts and reboots (hc quotas,hc rule reset-quota, usage on the
rules page). Rules that count traffic are checked before established
connections are accepted, so they see every packet. Per-address limits
group IPv6 by /64 by default (--group-v4,--group-v6). Meters,
byte rates and quotas in an imported ruleset carry over
(docs/rules.md). - Changes checked twice and applied atomically: validation of the
whole configuration with stable problem codes (docs/validation.md),
thennft -c, then onenft -ftransaction that replaces Housecarl's
own table,inet housecarl, and nothing else. Dynamic sets' entries
and the counters carry across. - Probation: a change made over the network rolls itself back unless
confirmed within two minutes. The web UI andhcconfirm their own
changes once they reach Housecarl again over a new connection, from the
same address (a change that cuts its client off can't, and rolls back);
--no-confirmand the "a person confirms each change" setting leave it
tohc confirmor the banner;
changes through the local socket are kept at once; a restart rolls
back what was pending. No rule is forced to keep SSH or the web UI
open. - At boot: the confirmed ruleset is loaded by
housecarl-ruleset.servicebefore the network comes up, without
housecarld. An empty configuration applies nothing. - Warnings about the machine: while
nftables.serviceis enabled
(it loads/etc/nftables.confat boot, and flushes every table when
stopped), and while the table an import came from still applies. - Statistics (Traffic → Statistics,
hc stats,/api/v1/stats/...):
traffic per interface and zone, drops by chain and when they happen,
hits per rule and the rules that matched nothing, the sources blocked
most and what they tried, connections against the kernel's limit, each
quota's use, and housecarld's and the host's memory and load, sampled
every minute into a database of their own (stats.db, kept 7 days per
minute, 90 days per hour, 2 years per day). On by default; traffic per
inside device is a setting (--stats-per-device) that adds counters
to the forward chain. Two charts on the dashboard; a warning when the
connection tracking table is nearly full (docs/stats.md). - Set names starting with
meter_,conn_,quota_orstats_are
refused (set_name_reserved): Housecarl's own sets use them, and a set
of yours named so could clash with them. - The zone matrix (Matrix,
hc matrix): what the rules do to new
connections between zones and to and from the firewall, worked out
from the rules in order, with each pair's exceptions; rules about
networks connected to other zones are left out of a pair. - Connections and tracing: the connections the kernel tracks, with
their NAT, and closing them so the rules check them again (Traffic →
Connections,hc connections); a rule option, "every packet", for
blocks that stop connections already open; and a packet tracer
(Traffic → Trace,hc trace) that follows packets through every
table's rules and names what accepted or dropped them. - Hits and the log: packet and byte counters for every rule, NAT rule,
built-in and policy; packets logged by rules and policies, read from
netlink log group 4171 (hc log -f, the Log page). - Dynamic sets whose entries expire by themselves, changed through
their own API with tokens that may be limited to one set
(sets:write:guests). - Import of an existing nftables ruleset (
hc import): rules keep
their order, defines name the sets, DNAT becomes port forwards, what
can't be translated stays as raw rules, with notes;hc takeover
deletes the old table, on probation (docs/import.md). DNAT maps and
verdict maps are expanded into one port forward or rule per element. - The
hcCLI, the REST API and the web UI (dashboard, rules per
chain with hits and reordering, NAT, zones, sets, services, the log,
settings, import, history with undo; the rule dialog keeps the less
used parts, such as rate limits, quotas and time windows, behind "+"
buttons; each chain's built-ins are listed, with their hits, and
switched in a window), with users, roles, scoped API
tokens, sessions, the audit log, and the web UI's certificate from
Let's Encrypt through Jarl, as in Steward. - Packaging: Debian packages
housecarlandhousecarl-cli, a
systemd unit whose only privilege isCAP_NET_ADMIN, daily backups. - The Housecarl logo: a carved Nordic doorway in Jarl's blue, with a
simplified version for small sizes, lighter on dark backgrounds; and a
HOUSECARL wordmark in Jarl's and Steward's angular letters.
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- Zones, address sets and services: interfaces grouped by what they