housecarl/CHANGELOG.md

Changelog

All notable changes to Housecarl are documented here. The format follows Keep a Changelog, and versions follow Semantic Versioning.

[Unreleased]

Added

• An administrator can make an API token for another user in the web UI: New token on the user's row under Users (the CLI's hc token create --user and the API could already).

• Ban lists (docs/bans.md). A program (Guard, which reads logs, or fail2ban) bans an address, of every port or of some, for a time; the ban list says what the address is kept from: the firewall itself (firewall), some hosts behind it (hosts, port forwards to them included), or everything. Bans are dropped ahead of every rule, established connections too, and the banned address's connections are closed. IPv6 addresses are banned by /64 (group_v6). Never banned: inside networks, the firewall's own addresses, whoever asks, and the list's never. Bans end by themselves, are cut to the list's longest time, survive restarts and reboots, and are audited, but aren't configuration (no history, probation or changesets). hc banlist, hc bans, hc ban, hc unban; Traffic → Bans in the web UI; /banlists and /banlists/{ref}/bans in the API; a bans grant that can name lists (bans:write:web), in the viewer and operator roles.

• A fail2ban action, contrib/fail2ban/action.d/housecarl.conf (installed under /usr/share/doc/housecarl/contrib/): fail2ban's bans go into a ban list, with the jail's port and protocol.

• Failed logins in the journal. A failed login and a refused API token are logged (msg="login failed" ip=… user=…), for Guard and fail2ban to act on.

• Quota usage as a share. What a quota used shows its percentage (12.3 GB of 50.0 GB used (24%), each address's in the quota dialog), on the Rules page, the dashboard and in hc quotas.

• Reset one address's quota, or give some back. hc rule reset-quota ID --address ADDR starts only that device's allowance again; --give 5gbytes takes that much off what was used instead (one address's, or everyone's): extra allowance until the next reset, without changing the rule. In the web UI, a rule's quota is one line (what it used, how it resets) that opens a dialog with the rest: usage per address, last and next reset, and Reset and Give back for everyone or one address. POST /rules/{ref}/reset-quota takes address and give.

• Names beside inside addresses. Connections, the log, quota usage, the dashboard's quotas and the statistics' devices and blocked sources show each inside address's name, found by a reverse lookup: laptop 192.168.1.20 in the web UI, 192.168.1.20 (laptop) in hc. Only inside addresses are looked up (an inside zone's networks, and private ones outside the external zones'). Names are cached for 10 minutes and never stored. names.enabled, names.resolver and names.cache in housecarl.yaml; hc --no-names; POST /names.

• Quotas on the dashboard. With any rule holding a quota, the dashboard lists them all: the allowance, what is used (for a per-address quota, how many addresses and the busiest) with a bar, and the next reset. Each opens its rule.

• Links to a rule open it. A rule named in the matrix, the log, the tracer, statistics or the dashboard's busiest rules opens the Rules page on its chain, scrolled to it and highlighted (#/rules?rule=ID). The Rules page shows each rule's ID (#410, as hc and labels name it) beside its order.

• A clearer zone matrix. A cell reads allow, block, or partly (some new connections let through, the rest not), with the exceptions counted by what they do (+3 -1 instead of +4), and what they let through: services with the addresses they're limited to (ssh from trusted, 5 port forwards), under the grid in hc matrix, in each cell on the Matrix page. A zone to itself is marked (only traffic routed between its interfaces passes the firewall). The details list each rule's hits. API: summary, allowed, blocked, open, same_zone, note, hits, and short and hits per exception. Raw rules that are a match and then accept, drop or reject (without interfaces) are read instead of shown as unknown.

• Shadow mode (shadow.enabled in housecarl.yaml; docs/shadow.md): Housecarl's ruleset is loaded beside the firewall you have but blocks, rejects and translates nothing. Drops and rejects are counted and accept instead (an accept only ends Housecarl's chain), policies accept and always log what they would drop, NAT only counts, MSS clamping and the flowtable are left out, and raw rules that do more than accept, drop or reject are left out with a warning (shadow_raw_left_out). Comments mark what would happen ([would drop]). shadow.position: Housecarl's filter chains run after the other firewall's (filter + 10, the default: what it would drop is what switching would break) or before (- 10); its NAT chains always first. Every change is checked by nftables in both forms, so leaving shadow mode can't fail. No probation; takeovers and closing connections are refused (409). The boot ruleset is the shadow one, and its fallback filters nothing. When a reload (flush ruleset) deletes Housecarl's table, housecarld puts it back (it listens to nftables' netlink notifications). mode in /status, /healthz and /auth/whoami; a banner in the web UI; would-be drops marked in the log (shadow) and the tracer (would_drop); hc ruleset --enforcing (GET /ruleset?enforcing=1) shows the ruleset for after. shadow_unprotected warns when no other table filters the input hook; nftables_service and takeover_pending aren't raised in shadow mode. The e2e test imports in shadow mode before taking over.

• Zone names at import: hc import --zone enp2s0=lan (repeat; interfaces given one name share a zone; Zone names on the Import page), and a note listing each zone and where its name came from. Defines holding a VLAN sub-interface (enp2s0.20) name their zone, and _ifname, _device and _nic are taken off define names too (docs/import.md, "How things are named").

• Import: sets with flags timeout become dynamic sets; a DNAT of several ports becomes one port forward per port.

Changed

• The ruleset's diff (Changes, hc changeset diff, --dry-run) names the chain each part is in on its @@ line (@@ -40,6 +40,8 @@ chain forward), as git diff names the function, so a rule added deep in a long chain says whether it is in input, forward or output.
• History shows the ruleset's diff. An entry's page (and hc history diff ID, GET /history/{id}/diff) shows what the change did to the ruleset, for entries made before this version too: the configuration before and after it is got back from the current one and rendered by this version.
• The rule dialog shows only the zone fields its chain can use: no "Going out on" for input and early, no "Coming in on" for output (they could only be refused). A zone left in a field the chain hides isn't sent.
• History lists a changed setting by its own fields (builtins.drop_invalid: false → true), on the web page and in hc history show, instead of the whole builtins before and after.
• Set names starting with ban_ are now reserved (set_name_reserved): ban lists' sets use them.
• Rules read as a direction. A match's zones are written lan → wan, any but wan → any, or with the firewall itself as the other end (lan → firewall in input, firewall → wan in output), instead of in lan · out wan and in not wan; exclusions read from any but X. On the Rules and NAT pages and in hc; the flags and JSON stay as they were.

Fixed

• The dashboard's bar for a per-address quota showed only the busiest address, so one address that used up its allowance filled it (100%). The bar is now all the addresses together, and the dashboard and the rule's quota line say how many addresses used theirs up.
• Changing how a quota counts lost or muddled what it used: per address to a total started at nothing, per source to per destination kept the sources' use as if it were the destinations', and other groups left the old entries behind. Now a total starts at the addresses' sum, wider groups add up their addresses, and what can't be carried starts again with a warning (quota_restarts) on the change.
• What the quotas used is saved after every change, not only every five minutes: a reboot soon after a change that counts a quota differently could bring back its usage counted the old way.
• Statistics' Quotas card linked every entry to the Rules page, not to its rule; each now opens its rule, named. Per-address quotas were missing from it (and from the quota:rN series): they count their addresses' sum.
• hc stats top devices listed each device twice (once for what it received, once for what it sent); it is one row with both again.
• hc rule add --before/--after/--first made two changes (create at the end, then move), so two history entries, two probations, and the rule briefly in force at the end of its chain; staged in a changeset, the place was lost. The create now takes the place (POST /rules?before=ID, after, first) and makes one change.
• hc matrix in a terminal: the colours' escape codes threw the columns out of line.
• hc counters (GET /counters) kept listing the objects of a configuration replaced since housecarld started (hc import --replace gives every object a new ID), beside the current ones; the totals of objects that no longer exist are now forgotten.
• Import: two base chains on one hook had their rules imported twice, and the second chain's leading built-ins were moved above the first chain's rules; they now follow each other by priority (read in a fixed order), with the stricter policy, and a note.
• Import: a rule inside a jumped-to chain that stays raw kept only its own text and so applied to everything; the jump's condition now goes in front. A jump and a rule matching the same field are combined only when one's addresses lie within the other's; else the rule stays raw. A jump's ports, ICMP types, connection status and hop limit were dropped; a limit or log on the jump is no longer silently lost.
• Import: a second match on the same field (ip saddr A ip saddr != B) replaced the first; != on the hop limit and TCP flags was read as ==. Such rules now stay raw, as written.
• Import: a forward-chain accept to a forwarded host and port without ct status dnat was folded into the port forward, which only lets forwarded connections through; it stays a rule now. An IPv6 accept limited to an interface no longer becomes a pinhole open to all.
• Import: raw rules naming a set of the old table made nftables refuse the ruleset; address sets are now renamed NAME_v4/NAME_v6, other sets written out with their elements, and what can't be is left out with a note. Rules naming a set that isn't imported stay raw instead of failing validation.
• Import: a DNAT to an IPv6 address, or with matches a port forward can't hold (an interface excluded, a limit, a log), is left out with a note instead of being imported without them.

[0.1.0] - 2026-10-19

The 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 like incusbr*; 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 ID or HOUSECARL_CHANGESET, and has hc changeset create/list/show/diff/apply/discard/remove. An applied changeset is on probation like any change. --dry-run shows 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), then nft -c, then one nft -f transaction 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 and hc confirm 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-confirm and the "a person confirms each change" setting leave it to hc confirm or 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.service before the network comes up, without housecarld. An empty configuration applies nothing. It fails closed: if the saved ruleset doesn't load, a fallback saved beside it (ruleset-fallback.nft) is, until housecarld puts the real one back: nothing new gets in from external zones, the inside keeps working (masqueraded), and the unit is marked failed with a critical message. hc status, the dashboard and /healthz say while the fallback is in force; the warning no_external_zone says when no zone is external, which would make the fallback close everything (docs/operations.md).
• The flowtable and interfaces that come and go: the boot ruleset has no flowtable (nftables on Debian 13's kernel refuses one naming a device that doesn't exist yet, such as ppp0 before PPPoE is up, and with it the whole file); housecarld watches the kernel's link messages and applies the ruleset again when a flowtable device appears or comes back as a new interface (PPPoE reconnecting). A guide to when the flowtable helps, and what it costs (docs/flowtable.md).
• GET /healthz for monitoring: ok, firewall (applied, unconfigured, fallback, missing), changes on probation and the machine's warnings, with HTTP 503 unless the firewall is in force; no login needed, read at most every five seconds.
• Import keeps a chain's head in order: once a would-be built-in at the head of a chain has to stay a rule (an invalid drop the forward chain needs after an exception), the built-ins after it stay rules too, in their place, instead of moving ahead of it: an ICMPv6 accept no longer jumps ahead of the invalid drop it came after.
• Renaming a zone, set or service changes the rules, NAT rules and port forwards that name it, in the same change (one history entry, one undo); before, a name in use couldn't change. Dynamic sets keep their names (their tokens and programs go by them).
• VLAN sub-interfaces (enp2s0.20) in zones and the flowtable, tested with tagged traffic (docs/rules.md).
• hc settings set --flowtable none (and none for the other lists) empties the list.
• Warnings about the machine: while nftables.service is enabled (it loads /etc/nftables.conf at 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_ or stats_ 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 hc CLI, 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 housecarl and housecarl-cli, a systemd unit whose only privilege is CAP_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.