The compose pinned 172.32.0.0/24 with a per-container ipv4_address, so two
concurrent runs asked docker for the same address space and the second failed
with a pool-overlap error. Request no subnet and let docker assign one from the
daemon pool. Peers address each other by the docker hostname the compose already
sets (host-a, host-b) rather than by literal IP; docker's embedded DNS is
per-network, so the same hostname in two runs resolves inside each run's own
subnet. Nothing this suite asserts on moves as a result: its checks run over the
fips0 overlay, whose addresses are derived from node npubs and are independent of
docker addressing, and the packaged nftables ruleset matches on interface rather
than on any address.
The generated config directory moves under the run suffix for the same reason it
did in the acl suite, and the run teardown gains the matching removal so a run
no longer leaves its directory behind.
Case (b) also wrote curl's output to a fixed path under /tmp. Two concurrent
runs shared that one file, and either run's cleanup landing between the other's
write and read left an empty read, failing the http_code check for a reason
having nothing to do with the firewall. It uses mktemp now.
As in the acl suite, the floating subnet removes one of the two obstacles to
concurrent runs. The compose project name is still fixed; the local CI runner
scopes it externally, a bare hand run does not, and the comment at the site says
so rather than claiming the file is self-sufficient.
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