Two local CI runs on one host both asked docker for 172.20.0.0/24 and the
second lost its whole static family to "Pool overlaps". Docker honours a
fixed subnet request verbatim, so the only robust fix is to stop making one:
fips-net now requests no subnet and docker assigns from its own pool, which
cannot hand the same range to two runs.
That means node addresses are not known before `up`, so peers address each
other by container hostname instead. The generator emits node-<id>, or the
topology's docker_host where the compose hostname differs — only the gateway
profile, whose services are gw-*. External peers keep the address the
topology gives them, since it is not ours to assign. The resolv.conf mount
stays: dnsmasq is what forwards these names to docker's resolver and .fips
to the daemon, so removing it would take out every .fips assertion.
generated-configs is now per-run as well. A shared directory let two runs
overwrite each other's node configs, which the subnet collision had been
hiding by killing runs before that window opened. The generator, the compose
bind mounts and env_file, the six scripts that read it, and teardown all
follow FIPS_CI_NAME_SUFFIX; unset, every path renders as before. Teardown
keeps the directory after a failed run, where it is the evidence of what the
failing nodes were configured with.
Three things this exposed that were wrong independently:
admission-cap built its tcpdump patterns from the topology file's docker_ip
literals. Floating the subnet makes those match nothing, which would have
left its expect-zero "no Msg2 leaked" assertion passing because it could no
longer see anything at all. It now reads addresses from the running
containers. Restarting the denied peers together also made them swap
addresses, so each peer's counts were really the pair's total; they are
restarted one at a time now, and a check fails the suite outright if two
denied peers ever share an address, because per-peer attribution is
impossible once they do.
Attribute lookups in the generator used a fixed ten-line window and read the
next node's fields when a node omitted an attribute. An external node
followed by an internal one was classified as internal, which under hostname
peering would emit a name that resolves nowhere. Lookups are bounded to the
node's own block; generated output is byte-identical for all eight
topologies.
The rekey outbound-only variant used to rewrite peer addresses to hostnames
to set up its scenario. The generator now does that everywhere, so the
rewrite matched nothing and was silently doing no work. It asserts the
premise instead, and fails if a numeric address ever reappears.
Verified by running three instances of this compose at once — tcp-chain plus
two independent meshes — which drew 10.128.2/3/4.0/24 with no overlap while
both meshes passed ping-test 20/20 over the real .fips path. tcp-chain is
run by neither CI runner, so it was checked by hand: chain peer counts 1/2/1
and multi-hop .fips reachable both directions over TCP.
gateway-lan still pins its own IPv4 and fd02:: ranges and is unchanged here,
so the gateway profile is not yet concurrency-safe.
Implement TCP transport for FIPS enabling firewall traversal and serving
as the foundation for future Tor transport. This is the first
connection-oriented transport in the system.
Key design decisions:
- FMP header-based framing: reuses existing 4-byte FMP common prefix for
packet boundary recovery with zero framing overhead
- Session survives TCP reconnection: Noise/MMP/FSP state bound to npub,
not TCP connection; MMP liveness is sole authority for peer death
- Connect-on-send: fresh connection on first send, transparent reconnect
- close_connection() trait method for cross-connection deduplication cleanup
New transport files:
- src/transport/tcp/mod.rs: TcpTransport, connection pool, accept loop
- src/transport/tcp/stream.rs: FMP-aware stream reader (shared with Tor)
Modified: transport trait (close_connection), TcpConfig, TransportHandle
match arms, create_transports(), initiate_connection() for connection-
oriented links, cross-connection tie-breaker cleanup, design docs.
Tree announce loop and TCP stability fixes:
- Preserve tree announce rate-limit state across reconnection: carry
forward last_tree_announce_sent_ms when a peer reconnects so the
rate-limit window isn't reset to zero
- Drop oversize TCP packets at sender: pre-send MTU check returns
MtuExceeded instead of writing to the stream, preventing receiver-side
connection teardown and reset-reconnect cycles
Chaos harness:
- TCP transport support: tcp_edges/has_tcp/tcp_peers in SimTopology,
transport-aware config_gen with per-edge transport type, TCP port 443,
pure-TCP node support
- Include all non-Ethernet edges in directed_outbound()
- Fix netem/links log messages to say "IP-based" instead of "UDP"
- Add tcp-chain, tcp-only, and tcp-mesh scenario files
Static harness:
- Transport-aware config generation (get_default_transport, transport_port)
- TCP transport injection via Python post-processing
- Add tcp-chain topology and docker-compose profile
Update the default UDP bind port from 4000 to 2121 (decimal) and the
default Ethernet EtherType from 0x88B5 to 0x2121 across all source
code, documentation, configuration templates, test fixtures, and
scripts. Remove references to "IEEE 802 experimental range" since
0x2121 is not in that range.
Johnathan Corgan