- Ethernet ioctl: cfg-gate the ioctl request parameter type — c_int on
musl, c_ulong on gnu — so the same code compiles on both
x86_64-unknown-linux-gnu and x86_64-unknown-linux-musl targets
- Chaos harness macOS support: replace direct host 'ip link' invocations
with a privileged Docker container helper (--net=host --pid=host) that
shares the Docker VM's namespaces, making veth pair setup work on both
Linux and macOS (where host 'ip' is unavailable and container PIDs
live inside the Docker Desktop VM)
- Python 3.9 compat: add 'from __future__ import annotations' to
docker_exec.py for X|Y union syntax support
- Add deploy/ to .gitignore
Co-authored-by: origami74 <origami74@gmail.com>
Implement raw Ethernet transport using AF_PACKET SOCK_DGRAM on Linux
with EtherType 0x88B5 (IEEE experimental range) and 1-byte frame type
prefix (0x00=data, 0x01=beacon).
Transport implementation:
- EthernetConfig with interface, ethertype, MTU, buffer sizes, and
four independent discovery knobs (discovery, announce, auto_connect,
accept_connections)
- PacketSocket/AsyncPacketSocket wrappers with ioctl helpers for
interface index, MAC address, and MTU queries
- EthernetTransport with Transport trait impl, async start/stop/send,
receive loop dispatching data frames and discovery beacons
- Discovery beacons (34 bytes: type + version + x-only pubkey) with
DiscoveryBuffer for peer accumulation and dedup
- Atomic statistics counters (frames, bytes, errors, beacons)
- Platform-gated with #[cfg(target_os = "linux")]
Transport-layer discovery integration:
- Promote auto_connect() and accept_connections() to Transport trait
with default implementations and TransportHandle dispatch
- Extract initiate_connection() so both static peer config and
discovery auto-connect share the same handshake initiation path
- Add poll_transport_discovery() to the tick handler to drain
discovery buffers and auto-connect to discovered peers
- Enforce accept_connections() in handle_msg1() — transports with
accept_connections=false silently drop inbound handshakes
Node integration:
- create_transports() handles Ethernet named instances
- resolve_ethernet_addr() parses "interface/mac" address format
- transport_mtu() generalized for multi-transport operation
Test harness:
- VethPair RAII struct for veth pair lifecycle management
- Three #[ignore] integration tests requiring root/CAP_NET_RAW:
two-node handshake, data exchange, mixed transport coexistence
- Chaos harness: transport-aware topology model, VethManager for
veth pairs between Docker containers, Ethernet-aware config gen,
netem split (HTB+u32 for UDP, root netem for veth), transport-aware
link flaps and node churn with veth re-setup
- Container entrypoint waits for configured Ethernet interfaces
before starting FIPS (handles veth creation timing)
- New scenarios: ethernet-only (4-node ring), ethernet-mesh (6-node
mixed UDP+Ethernet with netem and link flaps)
Documentation:
- fips-transport-layer.md: Ethernet section, beacon discovery, WiFi
compatibility, updated discovery state, trait surface additions,
implementation status table
- fips-configuration.md: Ethernet parameter table, named instances,
peer address format, mixed UDP+Ethernet example, complete reference
- fips-wire-formats.md: Ethernet frame type prefix note
Cost-based parent selection:
- Replace depth-only parent selection with effective_depth = depth + link_cost
- link_cost computed from locally measured MMP metrics: etx * (1.0 + srtt_ms / 100.0)
- Prevents bottleneck subtrees in heterogeneous networks where a LoRa link
at depth 1 would otherwise always beat fiber at depth 2
- Configurable hysteresis (default 0.2) prevents marginal parent switches
- Configurable hold-down timer (default 30s) suppresses re-evaluation
after parent switch
- Mandatory switches (parent lost, root change) bypass both safeguards
- Link costs passed as HashMap parameter to keep TreeState pure
Periodic re-evaluation:
- evaluate_parent() was only called on TreeAnnounce receipt or parent loss;
after tree stabilization, link degradation went undetected
- Added timer-based re-evaluation (reeval_interval_secs, default 60s) that
calls evaluate_parent() from the tick handler with current MMP link costs
- Respects existing hold-down and hysteresis safeguards
- Short-circuits when disabled or <2 peers
Design documentation:
- Update 7 design docs to reflect cost-based parent selection
- Replace depth-only algorithm descriptions with effective_depth model
- Replace rejected cumulative path cost spec with local-only design rationale
- Rewrite Example 2 (heterogeneous links) for local-only cost model
- Update config docs: parent_switch_threshold replaced by parent_hysteresis,
hold_down_secs, reeval_interval_secs
Chaos simulation enhancements:
- fips_overrides with deep merge for per-scenario FIPS config customization
- Explicit topology algorithm for deterministic test graphs
- Control socket querying via fipsctl for tree/MMP snapshot collection
- Edge existence validation in netem manager
- Per-link netem policy overrides
- 9 new chaos scenarios covering cost avoidance, depth-vs-cost tradeoffs,
stability, mixed topologies, periodic re-evaluation, and bottleneck parent
12 new unit tests, 667 total passing, clippy clean.
fips-link-layer.md:
- Rewrite Liveness Detection: explicit Heartbeat (0x51) with 10s interval
and 30s dead timeout replaces vague gossip-as-heartbeat description
- Add Auto-Reconnect section: MMP dead timeout triggers retry with
unlimited backoff for auto_reconnect peers
- Add Handshake Message Retry section: link + session layer resend with
exponential backoff within timeout window
- Add Heartbeat to Link Message Types table
- Update Implementation Status with three new implemented features
fips-configuration.md:
- Add handshake_resend_interval_ms, handshake_resend_backoff,
handshake_max_resends to rate_limit table
- Add heartbeat_interval_secs, link_dead_timeout_secs to general table
- Add peers[].auto_reconnect to peers table
- Note auto-reconnect bypasses max_retries in retry section
- Update complete reference YAML with all new parameters
fips-wire-formats.md:
- Rename 0x51 from reserved Keepalive to implemented Heartbeat
- Update Disconnect reason 0x07 to Heartbeat liveness timeout
testing/chaos/README.md:
- Add runner.log to output files
- Add Directed Outbound Configs subsection
Auto-reconnect:
- Add per-peer auto_reconnect config (default true) to PeerConfig
- schedule_reconnect() feeds removed peers back into retry system with
unlimited retries and exponential backoff after MMP dead timeout
- RetryState gains reconnect flag to distinguish startup retries
(max_retries-limited) from auto-reconnect (unlimited)
Retry re-fire fix:
- process_pending_retries() now pushes retry_after_ms past the handshake
timeout window after successful initiate_peer_connection(), preventing
retries from firing every tick with no backoff
Chaos sim improvements:
- Directed outbound configs: BFS spanning tree + lower-ID-first assignment
eliminates dual-connect race conditions in simulation
- Save runner log (runner.log) alongside per-node logs for event correlation
- Increase churn-20 traffic aggressiveness and node churn (max_down_nodes
3→5, traffic interval min 0s, duration max 90s, concurrent flows 5→10)
Johnathan Corgan