Case (a) sends an unallowed inbound request that the ruleset should
drop, and accepted any non-zero curl status as proof. A drop produces
no RST, so curl can only hit its deadline and exit 28; connection
refused, an unroutable address or a missing listener all fail too, with
different codes, and the check counted those as a blocked connection.
Require 28 exactly, so the assertion distinguishes silently dropped
from failed for some other reason. Confirmed against the harness: the
real run returns 28.
The baseline check matched `counter packets`, which any counter rule
satisfies whatever its verdict, including one that accepts. Require the
rendered drop rule instead.
The drop-counter read had the same weakness plus a worse one: it took
field three of the first line mentioning a counter, which is the packet
count only when the line begins with `counter`. On a rule such as
`tcp dport 9 counter packets 42 bytes 3000 drop` it printed the port
number. That shape is reachable, because the shipped ruleset includes
the operator drop-in directory ahead of the trailing default deny and a
drop-in may add its own counted drop. Extract by position within the
matched text, and take the last match rather than the first, since case
(a) falls through to the default deny that the ruleset emits as the
final rule.
Note in place at the baseline check that it still only proves a counted
drop rule exists somewhere in the table, not that it is the trailing
one; asserting rule position is a larger change than this warrants.
The sample output in the README is updated to the new wording.
End-to-end exercise the v0.3.0 nftables firewall baseline so the
security claim — "services on fips0 are not exposed by default" — is
validated in CI rather than by operator opt-in. The packaging postinst
state is pinned by the deb-install matrix; this suite pins the actual
ruleset behavior.
testing/firewall/ — new directory mirroring the acl-allowlist
precedent (kept in its own directory, not extending testing/static):
docker-compose.yml (52 lines): two FIPS containers on bridge
172.32.0.0/24, peered over UDP/2121. node-b mounts
packaging/common/fips.nft RO at /etc/fips/fips.nft and a generated
drop-in services.nft at /etc/fips/fips.d/.
test.sh (247 lines): four-case asserter
(a) curl from node-a to node-b:8000 → DROP (port not allowlisted;
terminal counter drop fires)
(b) curl from node-b to node-a:8000 → 200 OK (reply traverses
node-b's ct state established,related accept)
(c) ping6 a→b → success (icmpv6 echo-request accept)
(d) nc -z a→b:22 → success (drop-in tcp dport 22 accept honored
via include "/etc/fips/fips.d/*.nft")
Plus drop-counter check after case (a) confirms the dropped
connection actually hit the chain's terminal counter drop.
generate-configs.sh (111 lines): mirrors acl-allowlist generator,
produces the drop-in services.nft + fips configs.
README.md (111 lines): how to run, expected output, design notes.
.gitignore: ignores generated-configs/.
testing/ci-local.sh: FIREWALL_SUITES=(firewall) array + run_firewall
runner; dispatch in run_integration and run_suite mirroring
run_acl_allowlist.
.github/workflows/ci.yml: matrix row {suite: firewall, type:
firewall} + 3 steps gated on matrix.type == 'firewall' between
acl-allowlist and gateway. Reuses fips-linux artifact + fips-test:
latest image.
Activation note: the unified test image does not run systemd, so
test.sh invokes the fips-firewall.service ExecStart
(/usr/sbin/nft -f /etc/fips/fips.nft) directly. The systemd-unit
enablement path is covered by the deb-install matrix; this suite
exercises what the unit configures, not how it gets started.
Johnathan Corgan