Commit Graph
20 Commits
Author SHA1 Message Date
Johnathan Corgan 5a5dbe36da Merge branch 'master' into next
# Conflicts:
#	src/node/lifecycle.rs
#	testing/static/scripts/rekey-test.sh
2026-04-27 16:10:11 +00:00
34e00b9f6e Add Nostr-mediated overlay discovery and UDP NAT traversal (#53)
Optional peer discovery and NAT hole-punching path gated behind a new
`nostr-discovery` cargo feature. Nodes publish signed overlay endpoint
adverts to public Nostr relays, consume peer adverts to populate
fallback dial addresses, and use STUN-assisted UDP hole punching with
NIP-59 gift-wrap offer/answer signaling to establish direct UDP paths
between NATed peers. Once a punched socket is up, it is handed into
the existing FIPS UDP transport and the standard Noise/FMP session
stack takes over unchanged.

The cargo feature is in the default feature set
(`default = ["nostr-discovery"]`) so stock builds include it; a
build that explicitly disables default features (or selects a
feature set without `nostr-discovery`) does not link the nostr /
nostr-sdk crates and does not emit a no-op poll in the tick loop.
Runtime behavior is independently gated by
`node.discovery.nostr.enabled`, which defaults to false; if the
config enables Nostr on a non-feature build, startup logs a
warning and continues without it.

== Cargo feature and dependencies

- New cargo feature `nostr-discovery = ["dep:nostr", "dep:nostr-sdk"]`.
  Not in the default feature set.
- New optional Linux-only dependencies: `nostr 0.44` (features: std,
  nip59) and `nostr-sdk 0.44`. Gift-wrap unwrap is hand-rolled in
  `src/discovery/nostr/signal.rs` rather than relying on the SDK's
  rumor-author check, which FIPS sidesteps by trusting `seal.pubkey`
  exclusively.

== Wire format

Overlay advert event: `kind 37195`, parameterized replaceable
(NIP-01 application-defined replaceable range 30000-39999), with
`d = "fips-overlay-v1"`. The digits visually spell FIPS (7=F, 1=I,
9=P, 5=S); a relay survey confirmed the kind is unused.

Advert content carries the version tag, endpoint list
(`udp|tcp|tor` + addr), optional signal-relay and stun-server
metadata, and `issuedAt` / `expiresAt` timestamps. Endpoint
`addr: "nat"` is the sentinel that triggers traversal on the peer
side. NIP-40 `expiration` tag bounds staleness on permanent
shutdown. Lifecycle relies on parameterized-replaceable
supersession; the daemon does not emit NIP-09 kind-5 deletes —
strict relays (Damus, Primal) race delete-against-replace and can
silently drop the replacement.

Gift-wrapped signal event: `kind 21059`. Punch packets carry magic
values `PUNCH_MAGIC` / `PUNCH_ACK_MAGIC`, a sequence number, and a
16-byte session hash.

== Discovery surface

- `src/discovery.rs` (always compiled)
  - `EstablishedTraversal`: bound UDP socket + selected remote +
    peer npub + optional transport name/config tuning overrides.
  - `BootstrapHandoffResult`: returned on successful handoff —
    allocated transport id, local/remote addrs, peer NodeAddr,
    session id.
- `src/discovery/nostr/` (`#![cfg(feature = "nostr-discovery")]`)
  - `types.rs`: wire and control types described above. `ADVERT_KIND`
    constant. `BootstrapError` enumerates failure modes (disabled,
    missing advert, missing NAT endpoint, no usable relays, invalid
    advert, invalid npub, signal timeout, punch timeout, replay,
    STUN failure, protocol, nostr, io, serde, event-parse).
  - `runtime.rs`: `NostrDiscovery` coordinator. Owns the shared
    nostr-sdk `Client`, subscribes to advert + signal event kinds,
    maintains a bounded advert cache and a bounded seen-sessions
    replay set, drains `BootstrapEvent::{Established, Failed}` for
    the node to consume, exposes `update_local_advert`,
    `request_connect`, `advert_endpoints_for_peer`,
    `cached_open_discovery_candidates`, and `shutdown`.
  - `signal.rs`: NIP-59 gift-wrap encode/decode. Outbound wraps are
    built against per-attempt ephemeral keys; inbound events are
    unwrapped against the node identity.
  - `stun.rs`: RFC 5389/8489 Binding Request client with
    XOR-MAPPED-ADDRESS parsing for both IPv4 and IPv6; used only to
    observe the initiator's own reflexive address against its
    locally configured STUN list (peer-advertised STUN is
    informational, never an egress target).
  - `traversal.rs`: per-attempt candidate-pair punch planner.
    Allocates a fresh `0.0.0.0:0` UDP socket per attempt, enumerates
    LAN-private and ULA interface addresses alongside the STUN
    reflexive address, schedules probe/ack exchanges at the
    configured interval for the configured duration, and picks the
    first candidate pair that authenticates end-to-end.

Strategy ordering is Reflexive↔Reflexive first, then LAN, then
Mixed. The STUN-observed pair is the only candidate that's reliable
across arbitrary network topologies; trying it first prevents the
planner from latching onto a misleading host-candidate path before
the reflexive path gets a chance. There is no catch-all
Local↔Local strategy: a previous design that paired every local
host candidate from one side with every local host candidate from
the other could declare success on a one-way reachable asymmetric
L3 path (corporate VPN, Tailscale subnet route, overlapping private
address space), only for the FMP handshake to stall because the
return path didn't match. The legitimate `Lan` strategy still pairs
candidates that share a subnet.

== Configuration surface

`node.discovery.nostr.*` (`NostrDiscoveryConfig`), all `serde(default)`
with `deny_unknown_fields`:

- `enabled` (default false), `advertise` (default true)
- `advert_relays`, `dm_relays`, `stun_servers`: defaults are
  `wss://relay.damus.io`, `wss://nos.lol`, `wss://offchain.pub`
  for both relay lists, and Google / Cloudflare / Twilio for STUN.
  Operators are expected to override for production. Other
  verified-working public relays for reference:
  `nostr.bitcoiner.social`, `nostr-pub.wellorder.net`,
  `nostr.oxtr.dev`, `nostr.mom`.
- `app` (default `"fips-overlay-v1"`), `signal_ttl_secs` (120)
- `policy`: `NostrDiscoveryPolicy::{Disabled, ConfiguredOnly (default),
  Open}` — controls whether advert-derived endpoints are consumed
  only for peers carrying `via_nostr = true`, or also for
  non-configured peers within a budget cap.
- `share_local_candidates` (default false) — when false, the offer's
  `local_addresses` list is empty and peers see only the reflexive
  address. Enable per-node only for genuinely same-LAN deployments;
  off-by-default eliminates the misleading-path failure mode for
  the common case where peers are not on the same broadcast domain.
- `open_discovery_max_pending` (64) — caps queued open-discovery
  retries; bounded by available outbound slots.
- `max_concurrent_incoming_offers` (16) — semaphore against offer
  spam; excess offers are debug-logged and dropped.
- `advert_cache_max_entries` (2048) and `seen_sessions_max_entries`
  (2048) — bound memory under ambient relay volume; overflow
  evictions are debug-logged.
- `attempt_timeout_secs` (10), `replay_window_secs` (300)
- `punch_start_delay_ms` (2000), `punch_interval_ms` (200),
  `punch_duration_ms` (10000)
- `advert_ttl_secs` (3600), `advert_refresh_secs` (1800)

Per-peer and per-transport flags:

- `PeerConfig.via_nostr: bool` — when true (and Nostr is enabled),
  advert-derived addresses are appended as fallback dial candidates
  after static addresses for that peer.
- `PeerConfig.addresses` is now `serde(default)` and may be empty
  when `via_nostr: true`; validation requires at least one of the
  two to be present per peer, and the error message names the
  peer's npub.
- `UdpConfig.advertise_on_nostr: Option<bool>` and
  `UdpConfig.public: Option<bool>` — UDP transports can be
  advertised either as direct `host:port` (public = true) or as the
  `addr: "nat"` sentinel that triggers rendezvous on the peer side.
- `TcpConfig.advertise_on_nostr` and `TorConfig.advertise_on_nostr`
  — TCP and Tor onion endpoints can be advertised as directly
  reachable.
- A reserved peer address `transport: udp, addr: "nat"` parses without
  special-casing in YAML and routes through the bootstrap runtime.

Cross-field validation (`Config::validate`, called from `Node::new`
and `Node::with_identity`):

- Any transport with `advertise_on_nostr = true` requires
  `node.discovery.nostr.enabled = true`.
- Any peer with `via_nostr = true` requires
  `node.discovery.nostr.enabled = true`.
- A non-public UDP advert (`advertise_on_nostr = true`,
  `public = false` — i.e. `udp:nat`) additionally requires at least
  one `dm_relay` and at least one `stun_server`.
  Surfaced as `ConfigError::Validation`.

== Node integration

`src/node/lifecycle.rs` is the main integration point.

- At node start (after transports are up, before TUN), if Nostr is
  enabled and the feature is compiled in, `NostrDiscovery::start` is
  invoked, the initial local overlay advert is built from the live
  transport set and published, and the runtime handle is stored.
- The rx tick loop calls `poll_nostr_discovery` (feature-gated both
  at method definition and call site), which refreshes the local
  advert, drains bootstrap events, adopts established traversals,
  schedules retries for failed traversals, and — under `policy:
  open` — enqueues outbound retries for non-configured peers
  visible in the advert cache, bounded by
  `open_discovery_max_pending` and the remaining outbound slots.
- Outbound peer dialing is refactored to `try_peer_addresses`, which
  first exhausts the static address list in priority order and only
  then appends advert-derived fallback addresses; both lists run
  through the same `attempt_peer_address_list` code path. The
  `udp:nat` sentinel address triggers `NostrDiscovery::request_connect`
  for the peer instead of a direct dial and returns `Ok(())`.
- `build_overlay_advert` walks operational transports, consults
  per-instance `UdpConfig` / `TcpConfig` / `TorConfig` (matching by
  optional transport instance name), and emits an `OverlayAdvert`
  including `signalRelays` and `stunServers` when any UDP endpoint
  is advertised as NAT.
- `adopt_established_traversal` is the bootstrap handoff API:
  allocates a new `TransportId`, constructs a `UdpTransport` with
  the user-supplied (or default) `UdpConfig`, calls the new
  `adopt_socket_async` to reuse the punched socket verbatim,
  registers the transport in the normal transport map, records it
  in `bootstrap_transports`, and calls `initiate_connection` so the
  normal handshake path runs. On failure, the transport is stopped
  and removed cleanly and the set membership is rolled back.
- On clean shutdown, `NostrDiscovery::shutdown` is awaited so
  background tasks stop before transports are torn down. (The
  advert is not explicitly retracted; NIP-40 expiration plus the
  next refresh from any live publisher supersedes it.)

New `Node` fields:

- `nostr_discovery: Option<Arc<NostrDiscovery>>` (feature-gated).
- `bootstrap_transports: HashSet<TransportId>` — per-peer UDP
  transports adopted from NAT traversal, cleaned up via
  `cleanup_bootstrap_transport_if_unused` whenever the link,
  connection, peer, or pending-connect referencing them is removed.

Retry and error surface:

- `RetryState.expires_at_ms: Option<u64>` — optional absolute expiry
  for a retry entry. `pump_retries` drops expired entries with an
  info log. Used for open-discovery retries, which expire at two
  times the advert TTL.
- New `NodeError::BootstrapHandoff(String)` returned from
  `adopt_established_traversal` when the underlying transport
  adoption fails or local address discovery fails.
- New `ConfigError::Validation(String)`.
- A small refactor extracts `Node::now_ms()` and reuses it across
  lifecycle, rx-loop tick, and timeout bookkeeping.

== UDP transport

`src/transport/udp/`:

- `UdpRawSocket::adopt(std::net::UdpSocket, recv_buf, send_buf)`:
  adopts an externally bound socket, makes it non-blocking, applies
  the configured buffer sizes (warning if the kernel clamps), and
  reports the resulting local address. Preserves the NAT mapping —
  no rebind.
- `UdpTransport::adopt_socket_async(std::net::UdpSocket)`: the
  `start_async` analogue for an already-bound socket, wiring the
  async socket and recv task exactly as the fresh-bind path would.
- `Drop` impl for `UdpTransport`: if a transport is dropped while
  still holding a recv task or socket (for example on error
  teardown), aborts the task, clears the socket, and emits a debug
  log so the cleanup is visible in tracing rather than silent.

== Logging and observability

Default `EnvFilter` demotes third-party relay-pool DEBUG output to
TRACE-only: `nostr_relay_pool`, `nostr_sdk`, and `nostr` are pinned
at INFO when our level is anything below TRACE, and at TRACE when
our level is TRACE — so the raw frames are still reachable when
explicitly asked for. RUST_LOG continues to override completely.

Concise one-line DEBUG events are emitted at the meaningful points
in the discovery / hole-punch sequence:

- `advert: published` (event id, relay count, endpoints, ttl)
- `advert: peer cached` (notify-loop ingress for non-self)
- `advert: resolved` (cache hit / relay fetch outcome)
- `traversal: initiator starting`
- `traversal: initiator STUN observed` (reflexive, local count)
- `traversal: offer sent` (session id, relay count, event id)
- `traversal: answer received` (accepted, reflexive, local)
- `traversal: initiator punch succeeded` (remote addr)
- `traversal: offer received` (responder side)
- `traversal: responder STUN observed`
- `traversal: answer sent`
- `traversal: responder punch succeeded`

Npubs are shortened to `npub1<4>..<4>` and event/session ids to
their first 8 hex characters.

Other operator-facing logs:

- `UdpTransport` adoption and drop paths log at info / debug.
- `adopt_established_traversal` logs at debug on entry and info on
  successful return, tagged with peer npub, session id, transport
  id, and both socket endpoints, so the bootstrap handoff is
  traceable end-to-end alongside the `UdpTransport::drop` log.
- `cleanup_bootstrap_transport_if_unused` logs at debug when the
  reference-count check drops an adopted transport.
- `connect_peer` tags its entry `debug!` with `peer_npub` so
  downstream STUN, punch, and handshake logs for the same peer
  correlate for operators.
- Advert-cache and seen-sessions overflow evictions log at debug so
  mis-sized caps are visible under ambient relay volume.
- Gift-wrap unwrap failures on `SIGNAL_KIND` events log at trace
  (hot path: fires for every unrelated signal event on the same
  relay).
- Traversal-offer handler failures log at debug. Expected conditions
  such as punch timeout on symmetric NAT are covered there; real
  problems are reported upstream via `BootstrapEvent::Failed`.
- Inbound-offer rate-limit messages name the governing config field
  (`max_concurrent_incoming_offers`) and state that the offer was
  rate-limited rather than failing.

== Tests

- 18 new unit tests in `src/discovery/nostr/tests.rs` covering advert
  encoding, signal envelope round-trip, STUN parsing, punch-packet
  codec, and replay-window enforcement. Run under the
  `nostr-discovery` feature.
- Config-validation tests in `src/config/mod.rs` covering the three
  cross-field invariants and YAML parsing of the full
  `node.discovery.nostr` block plus `peers[].via_nostr`, empty
  `addresses` with `via_nostr: true`, and a `udp: nat` address.
- `src/node/tests/bootstrap.rs` integration tests that drive a
  synthetic traversal (bound UDP socket pair + synthetic peer
  identity) through `adopt_established_traversal` and assert the
  Noise handshake completes over the adopted socket.
- Punch-planner tests assert reflexive-before-LAN ordering and that
  same-LAN scenarios still include the LAN target in the plan.
- `testing/nat/` Docker NAT lab harness:
  - Local `strfry` relay, local STUN responder, and one or two
    router containers performing `iptables` NAT.
  - Node LAN interfaces are provisioned with explicit `veth` pairs
    injected into the node and router namespaces so every packet
    traverses the router namespace (plain Docker bridges are not
    used for the LAN).
  - `cone` scenario: both peers behind full-cone-emulation NAT
    (SNAT with source-port preservation, inbound DNAT back to the
    single LAN host regardless of remote source); asserts UDP
    traversal succeeds and link remote addresses are on the router
    WAN subnet.
  - `symmetric` scenario: `MASQUERADE --random-fully`; asserts UDP
    traversal fails and TCP fallback converges over router-
    published WAN addresses.
  - `lan` scenario: both peers share a LAN subnet; asserts LAN
    addresses are preferred over reflexive ones.
  - Cleanup tears down all profile-gated services
    (`--profile cone --profile symmetric --profile lan`) so no
    orphan containers survive a run.
- `testing/scripts/build.sh` builds the Docker test image with
  `--features "tui nostr-discovery"` by default so NAT-harness
  binaries include bootstrap support.

== CI

- Linux release build and nextest unit-test job both use
  `--features "gateway nostr-discovery"` so the feature-gated code
  and its unit tests compile and run in CI.
- Three new integration matrix entries (`nat-cone`, `nat-symmetric`,
  `nat-lan`) invoke `testing/nat/scripts/nat-test.sh`, collect
  `docker compose logs` on failure, and always stop containers.

== Packaging and operations

- `packaging/common/fips.yaml` ships a fully commented
  `node.discovery.nostr.*` block, plus documented
  `advertise_on_nostr` / `public` examples under the UDP transport,
  an `advertise_on_nostr` example under TCP, and a `via_nostr: true`
  example under the static peer section with both a direct
  `host:port` UDP address and a `udp: nat` fallback.
- `.github/workflows/package-openwrt.yml`: NIP-94 release event
  publishes target the new default relay set.

== Documentation

- `README.md`: overlay discovery + NAT traversal moved from
  "Near-term priorities" into "What works today".
- `docs/design/fips-intro.md`: rewrites the paragraphs that
  previously described Nostr discovery and NAT traversal as future
  work; describes the shipped mechanism and the feature gate.
- `docs/design/fips-transport-layer.md`: drops the "(future
  direction)" qualifier from the Nostr Relay Discovery section,
  expands with the `udp:nat` advertisement and bootstrap handoff
  description, and updates the Current State callout.
- `docs/design/fips-mesh-layer.md`: notes that mid-session NAT
  rebinding (roaming) and initial NAT traversal (Nostr path) are
  distinct mechanisms.
- `docs/design/fips-configuration.md`: documents the full
  `node.discovery.nostr.*` surface, including the three resource
  caps and `share_local_candidates`.
- `docs/design/fips-nostr-discovery.md`: design and configuration
  reference for the shipped mechanism, including the empty-
  `addresses`-with-`via_nostr` shorthand.
- `docs/proposals/nostr-udp-hole-punch-protocol.md`: adds an
  Implemented status callout, clarifies that the punch socket is
  per-peer and per-attempt rather than shared with the application
  listener, aligns field names with the shipped JSON
  (`sessionId`, `issuedAt` / `expiresAt`, `reflexiveAddress`,
  `localAddresses`, `stunServer`), sets the `d`-tag to
  `fips-overlay-v1`, names the kind as 37195, and notes that
  advertised STUN entries are informational.
- `docs/proposals/README.md`: adds a Status column and marks the
  hole-punching proposal Implemented.
- `CHANGELOG.md`: Unreleased > Added entry covering the discovery
  path, STUN/punch path, configuration surface, and Docker NAT lab.

Co-authored-by: Johnathan Corgan <johnathan@corganlabs.com>
2026-04-27 08:15:58 -07:00
Johnathan Corgan 9e93b0b224 Merge branch 'master' into next 2026-04-13 06:37:23 +00:00
Johnathan Corgan 42834b8008 Fix auto-connect reconnect on graceful peer disconnect
handle_disconnect() called remove_active_peer without scheduling a
reconnect, orphaning auto-connect peers on a clean upstream shutdown.
Mirror the pattern from the other three peer-removal paths (link-dead,
decrypt failure, peer restart) which all schedule reconnect after
removal.

Adds test_disconnect_schedules_reconnect regression test that verifies
handle_disconnect populates retry_pending for an auto-connect peer.
Visibility of handle_disconnect bumped to pub(in crate::node) for
direct unit-test access.

Fixes #60.
2026-04-13 05:34:51 +00:00
Johnathan Corgan eb8479eb20 Heterogeneous bloom filters: delta compression, variable sizing, adaptive heuristic
Replace fixed 1KB bloom filters with variable-size filters (512B-32KB)
that adapt to each node's position in the spanning tree.

Core changes:
- Internal storage: Vec<u8> → Vec<u64> for word-level operations
- Delta compression: XOR diff with word-level RLE, sequence-based
  NACK protocol for full retransmit recovery
- Size conversion: fold (large→small) and duplicate (small→large)
  with auto-converting merge for mixed-size filter combination
- Native-size storage: peer filters stored at advertised size for
  full-resolution routing queries, converted only for outgoing filter
- Adaptive sizing: outgoing fill ratio drives step-up/step-down
  between size classes with hysteresis (20%/5% thresholds)
- Filter size decoupled from FMP negotiation: announced dynamically
  in filter updates, bit 7 and TLV field 1 removed from handshake

Wire format: FilterAnnounce gains flags byte (delta bit), base_seq
field, RLE-compressed payload. New FilterNack message (0x21) for
out-of-sequence delta recovery.
2026-04-11 08:16:01 +00:00
Johnathan Corgan f4278f1dd7 Add FMP node profile negotiation with mixed-profile integration tests
NodeProfile enum (Full/NonRouting/Leaf) with FMP feature bitfield:
bits 0-2 profile, bits 3-6 MMP wants/provides, bit 7 bloom filter
size negotiable. Bloom size TLV always sent with min=max=1KB.

Config mapping: leaf_only -> Leaf, disable_routing -> NonRouting.
Profile and agreed bloom size stored on PeerConnection and
ActivePeer. Handshake msg2/msg3 carry FMP negotiation payload
with profile validation and bloom size agreement.

MMP report sending gated by profile wants/provides. Parent
selection and routing constraints skip non-full peers. One-way
bloom filters for non-routing peers (F inserts N as dependent).
Leaf mode: single-peer enforcement, suppress tree announces and
discovery forwarding.

Mixed-profile integration test: A(Full) + B(Full) + C(NonRouting)
+ D(Leaf) with 9 connectivity assertions.
2026-04-11 08:16:01 +00:00
Johnathan Corgan 13c0b70dc3 Add rustfmt formatting policy and reformat codebase
Add rustfmt.toml with stable defaults and apply cargo fmt to all
source files. This establishes a consistent formatting baseline
for CI enforcement.
2026-04-10 08:27:07 +00:00
KieranandJohnathan Corgan e8ef15acb7 Fix stale session cleanup and identity cache pre-seeding
Cherry-picked from v0l PR #6 (issue #5):

1. remove_active_peer() now removes the end-to-end session from
   self.sessions when evicting a peer. The stale Established entry
   caused initiate_session() to silently return Ok(()) via the
   is_established() guard, preventing session re-establishment after
   link-layer reconnection.

2. initiate_peer_connections() pre-seeds the identity cache from
   configured peer npubs at startup, so TUN packets can be dispatched
   immediately without waiting for handshake completion.

3. schedule_reconnect() preserves accumulated backoff when a retry
   entry already exists, preventing exponential backoff reset on
   repeated link-dead cycles.

Includes regression tests for all three fixes.
2026-03-16 02:06:58 +00:00
Johnathan Corgan 5f7fe989f3 Fix rekey dual-initiation, parent selection, peer reconnect, and control socket
Rekey dual-initiation race (FMP + FSP):
When both sides' rekey timers fire simultaneously on high-latency links
(Tor ~700ms RTT), both msg1s cross in flight before dampening can
suppress the second initiation. Each node acts as both initiator and
responder, with set_pending_session() from the responder path destroying
the initiator's in-progress state. Each side ends up with a
pending_new_session from a different Noise handshake, causing AEAD
verification failure after cutover and link death. Fix: deterministic
tie-breaker in both FMP msg1 handler and FSP SessionSetup handler
(smaller NodeAddr wins as initiator). Also guard against pending session
overwrite from retransmitted msg1s.

Parent selection SRTT gate:
Peers without MMP RTT data are excluded from parent candidacy via
has_srtt() filter, preventing freshly reconnected peers from appearing
artificially attractive. First-RTT triggers immediate parent re-eval.
The gate in evaluate_parent() skips unmeasured candidates when any peer
has cost data, but falls back to default cost 1.0 during cold start
when no peer has MMP data yet.

Auto-reconnect on all peer removal paths:
The excessive-decryption-failure and peer-restart epoch-mismatch removal
paths were missing schedule_reconnect() calls, causing auto-connect peers
to be permanently abandoned after those events.

Control socket accessibility:
Socket and parent directory chowned to root:fips with mode 0770/0750 so
group members can use fipsctl/fipstop without root.

Log level changes:
Default RUST_LOG changed to debug in systemd service files. "Unknown
session index" log reduced from debug to trace.
2026-03-16 00:51:55 +00:00
Johnathan Corgan bf117df0ca Add periodic Noise rekey with fresh DH for forward secrecy (FMP + FSP)
Implement periodic full rekey at both protocol layers using fresh DH
key exchanges. Uses the existing K-bit flag (FLAG_KEY_EPOCH /
FSP_FLAG_K) to coordinate cutover between peers.

FMP layer (IK pattern):
- ActivePeer gains rekey state: pending/previous sessions, K-bit epoch
  tracking, drain window, dampening timer
- Handshake state stored on ActivePeer with msg1 sent on existing link
- Encrypted frame handler detects K-bit flips, promotes pending
  sessions, falls back to previous session during drain
- Handshake handlers distinguish rekey from new connections using
  addr_to_link lookup with identity-based fallback
- Free all session indices (current, rekey, pending, previous) on
  peer removal

FSP layer (XK pattern):
- SessionEntry gains parallel rekey fields with XK-specific state
  for the 3-message handshake
- Route availability check before FSP rekey initiation
- Encrypted session handler adds K-bit flip detection and dual-session
  decrypt fallback
- SessionSetup/Ack/Msg3 handlers extended for rekey paths

Defense-in-depth:
- Consecutive decryption failure detector (threshold=20) triggers
  forced peer removal instead of waiting for link-dead timeout
- Identity-based rekey detection as fallback when addr_to_link
  doesn't match (e.g., TCP ephemeral ports)

Configuration: RekeyConfig with enabled flag, after_secs (default 120),
and after_messages (default 65536) thresholds.

Logging: info for successful K-bit cutover completions, warn for
failures, debug for intermediate handshake steps, trace for routine
operations (resends, drain cleanup).

Rekey lifecycle:
1. Timer/counter fires -> initiator starts new handshake
2. Old session continues handling traffic during handshake
3. Handshake completes -> initiator cuts over, flips K-bit
4. Responder sees flipped K-bit -> promotes new session
5. Both keep old session for 10s drain window
6. After drain, old session discarded

Integration test: Docker-based multi-phase test exercising both FMP
and FSP rekey with aggressive timers (35s). Verifies connectivity
across all 20 directed pairs survives two consecutive rekey cycles.
Includes rekey topology, docker-compose profile, and CI matrix entry.

Increase ping test convergence wait from 3s to 5s for CI reliability.
2026-03-07 18:33:27 +00:00
Johnathan Corgan 56d39f223b Add ECN congestion signaling and transport congestion detection
Implement hop-by-hop ECN congestion signaling through the FMP layer,
transport-level congestion detection via kernel drop counters, and
chaos harness integration for end-to-end validation.

FMP/session ECN plumbing:

- Thread ce_flag parsed at link layer through dispatch_link_message,
  handle_session_datagram, handle_session_payload, and
  handle_encrypted_session_msg to session delivery
- Replace hardcoded false in session-layer record_recv() with actual
  ce_flag, activating ecn_ce_count tracking in session MMP

ECN congestion detection and CE relay:

- Add EcnConfig (node.ecn.*) with configurable loss_threshold (5%)
  and etx_threshold (3.0) for transit congestion detection
- Add send_encrypted_link_message_with_ce() that ORs FLAG_CE into FMP
  header flags; original method delegates with ce_flag=false
- Compute outgoing_ce = incoming_ce || local congestion on next-hop
  link, enabling hop-by-hop CE relay through transit nodes

IPv6 ECN-CE marking:

- Mark ECN-CE (0b11) in IPv6 Traffic Class on received DataPackets
  before TUN delivery when FMP CE flag is set
- Only marks ECN-capable packets (ECT(0)/ECT(1)); Not-ECT packets
  unchanged per RFC 3168

Transport congestion abstraction and UDP kernel drop detection:

- Add TransportCongestion struct to transport layer for transport-
  agnostic local congestion indicators
- Replace tokio::UdpSocket with AsyncFd<socket2::Socket> using
  libc::recvmsg() with ancillary data parsing
- Enable SO_RXQ_OVFL for kernel receive buffer drop counter on every
  packet, wiring up previously-stubbed UdpStats.kernel_drops
- Add TransportDropState for per-transport delta tracking with 1s
  tick sampling via sample_transport_congestion()
- Extend detect_congestion() with transport kernel drop check
  alongside MMP loss metrics

Congestion monitoring and control:

- Add CongestionStats (ce_forwarded, ce_received, congestion_detected,
  kernel_drop_events) to NodeStats with snapshot serialization
- Wire counters into forwarding path, session handler, and transport
  drop sampling with rate-limited warn logging (5s interval)
- Expose congestion data in show_routing control query and
  ecn_ce_count in show_mmp peer entries
- Add congestion counters to fipstop routing tab in two-column layout

Chaos harness integration:

- Add query_routing(), query_transports(), snapshot_all_congestion()
  to chaos control module
- Add congestion/kernel-drop log analysis in logs module
- Add congestion-stress scenario: 10-node tree, 1 Mbps bandwidth,
  5-10% netem loss, heavy iperf3 traffic
- Add IngressConfig for tc ingress policing with per-peer policer
  filters simulating upstream bandwidth bottlenecks
- Add iperf3 JSON result capture to traffic manager for throughput
  measurement across scenarios
- Add ECN A/B test scenarios (ecn-ab-on/off.yaml) with ingress
  policing and comparison script
- Enable TCP ECN negotiation (tcp_ecn=1 sysctl) in container
  entrypoint for end-to-end CE propagation

Tests:

- 10 ECN unit/integration tests: mark_ipv6_ecn_ce variants, CE relay
  chain (3-node propagation), EcnConfig serde roundtrip
- 3 transport drop congestion detection unit tests

Documentation:

- Update fips-mesh-layer.md: replace outdated CE Echo stub with full
  ECN Congestion Signaling section covering detection logic, CE relay,
  IPv6 marking, session tracking, and monitoring counters
- Update fips-configuration.md: add node.ecn.* parameter table and
  ecn block in complete reference YAML
- Update fips-transport-layer.md: add Congestion Reporting section
  with TransportCongestion struct, congestion() trait method, and
  per-transport status; document AsyncFd/recvmsg/SO_RXQ_OVFL in UDP
- Update chaos README: add congestion/ECN scenario docs, ingress
  traffic control, and iperf3 JSON capture sections
- Update README.md: add ECN to features list and "What works today";
  update transport and tooling entries
2026-03-05 17:05:57 +00:00
Johnathan Corgan 05e3853ca1 Suppress repeated replay detection log messages during link transitions
Add per-peer replay suppression counter to ActivePeer. Log the first 3
replay detections at DEBUG, then suppress with a one-time notice. Emit
a summary count on session replacement or peer removal.

Non-replay decryption errors continue to be logged unconditionally.
2026-02-23 19:56:12 +00:00
Johnathan Corgan 717be3d960 Restrict bloom filter propagation to tree edges, update design docs
Gate peer_inbound_filters() to only collect from tree peers (parent
and children), so outgoing filter computation merges only tree-sourced
information. All peers still receive FilterAnnounce messages and store
filters locally for routing queries — the restriction is only on what
gets merged into outgoing filters.

This prevents bloom filter saturation where mesh shortcuts cause every
node's filter to converge toward the full network. With tree-only
merge, filters contain subtree (from children) + complement (from
parent) + single-hop mesh views.

Implementation:
- Add is_tree_peer() helper to determine tree parent/child relationship
- Gate peer_inbound_filters() to tree peers only (single control point)
- Trigger bloom filter exchange on tree relationship changes
- Add est_entries, set_bits, fill ratio, and tree_peer fields to
  FilterAnnounce send/receive debug logs
- Add test_bloom_filter_split_horizon test verifying directional
  asymmetry: upward filters contain only the child's subtree, downward
  filters contain only the complement
- Add print_filter_cardinality diagnostic helper for test inspection

Design docs:
- fips-bloom-filters.md: Add directional asymmetry and mesh peer filter
  subsections, update per-peer filter model, saturation mitigation,
  implementation status table
- fips-mesh-operation.md: Update filter propagation description, add
  directional asymmetry, tree relationship change trigger
- fips-intro.md: Rewrite bloom propagation paragraph for tree-only merge
2026-02-23 14:00:00 +00:00
Johnathan Corgan a8d3627072 Add link-layer heartbeat and liveness timeout for dead peer detection
Sends a 1-byte encrypted heartbeat (0x51) to each peer every 10s.
If no frame is received from a peer within 30s, the peer is removed
via remove_active_peer(), triggering tree reconvergence, coord cache
flush, and bloom filter recomputation.

This fixes the critical bug where UDP peers that silently died
(e.g., container stopped) were never detected or removed, leaving
the spanning tree permanently stale.

Both intervals are configurable via node.heartbeat_interval_secs
and node.link_dead_timeout_secs.
2026-02-19 20:53:51 +00:00
Johnathan Corgan 9605cbafe3 Human-readable peer identifiers in log messages
Replace raw NodeAddr hex strings in log output with human-readable
identifiers using a four-tier lookup: configured alias, active peer
short npub, session endpoint short npub, or truncated hex fallback.

- Add PeerIdentity::short_npub() for compact npub display (npub1xxxx...yyyy)
- Add NodeAddr::short_hex() for compact hex fallback (first 4 bytes + ...)
- Add peer_aliases map populated at startup from peer config
- Add Node::peer_display_name() with four-tier resolution
- Add SessionEntry::remote_pubkey() accessor for session-layer lookups
- Update all 120 log field occurrences across 11 handler/node files
- Pass pre-computed display names to MMP static metric/teardown methods
  to work around borrow checker constraints in iterator loops
2026-02-19 05:04:19 +00:00
Johnathan Corgan d8cb4d407e FLP wire format revision and MMP link-layer measurement protocol
## FLP Wire Format Revision

Replace the 1-byte discriminator with a structured wire format:

- 4-byte common prefix (ver+phase, flags, payload_len) and 16-byte
  established frame header with AEAD AAD binding
- 5-byte encrypted inner header (4-byte session-relative timestamp +
  1-byte message type) on all link messages
- Phase-based packet dispatch replacing discriminator-based dispatch
- SessionDatagram reassigned from type 0x40 to 0x00; add SenderReport
  (0x01) and ReceiverReport (0x02) message types for MMP
- SessionDatagram: rename hop_limit to ttl, add path_mtu field (u16 LE)
  with min(datagram.path_mtu, transport.mtu()) at forwarding
- Updated handshake packets (msg1: 87->90 bytes, msg2: 42->45 bytes)
- FIPS_OVERHEAD updated from 135 to 144 bytes

## MMP Link-Layer Measurement Protocol

Add the Metrics Measurement Protocol for link quality measurement
between FIPS peers. Measures RTT, loss, jitter, throughput, OWD trend,
and ETX from periodic sender/receiver reports exchanged over established
links.

Module layout:
- mmp/algorithms.rs: JitterEstimator, SrttEstimator, DualEwma, OwdTrend,
  SpinBit, ETX computation
- mmp/report.rs: SenderReport (48B) and ReceiverReport (68B) wire format
- mmp/sender.rs: per-peer TX counters and interval tracking
- mmp/receiver.rs: per-peer RX counters, jitter, loss, gap tracking
- mmp/metrics.rs: derived metrics from report processing (SRTT, goodput_bps)
- mmp/mod.rs: MmpMode (Full/Lightweight/Minimal), MmpConfig, MmpPeerState
- node/handlers/mmp.rs: report dispatch, timer-driven generation, operator
  logging (periodic + teardown)

Integration: per-frame TX/RX hooks in encrypted message handling, report
dispatch from link message router, timer-driven generation from tick
handler, and periodic operator logging with throughput formatting.

Three operating modes: Full (sender + receiver reports, spin bit, CE echo),
Lightweight (receiver reports only), Minimal (spin bit + CE echo only).

## Design Documentation

Updated FLP sections across all design documents to match the implemented
wire format, including revised overhead calculations and numeric values.

568 tests pass, clippy clean.
2026-02-18 21:54:21 +00:00
Johnathan Corgan 89bc9cc4b0 Fix bloom filter cascade: gate re-announcements on content change
FilterAnnounce messages never settled in steady state because
handle_filter_announce unconditionally marked all peers for
re-announcement on every inbound filter, creating a perpetual
ping-pong at ~1 message/sec.

Added last_sent_filters tracking to BloomState. mark_changed_peers()
computes outgoing filters and compares against what was last sent,
only marking peers whose filter content actually differs.
2026-02-14 23:36:39 +00:00
Johnathan Corgan 9a7fa921ab Discovery protocol: LookupRequest/LookupResponse handlers
Implement the coordinate discovery protocol with flood-based lookup
and reverse-path response routing.

Wire format: LookupRequest (0x30) encode/decode with TTL, visited
bloom filter, origin coords. LookupResponse (0x31) encode/decode
with target coords and Schnorr proof signature.

Handler logic: request dedup by request_id, visited filter loop
prevention, TTL enforcement, lazy purge of expired entries (10s).
Response routing: originator caches route in route_cache, transit
nodes reverse-path forward via recent_requests.

Node state: RecentRequest struct, route_cache (RouteCache), and
recent_requests map for dedup + reverse-path forwarding.

13 handler tests (9 unit + 4 integration) plus 4 protocol tests.
392 tests pass, clean build.
2026-02-12 14:46:33 +00:00
Johnathan Corgan 009101ee4a SessionDatagram forwarding handler with coordinate cache warming
Add handle_session_datagram handler replacing the 0x40 dispatch stub.
Transit nodes now decode the datagram envelope, enforce hop limits,
warm coordinate caches from SessionSetup/SessionAck/DataPacket payloads,
route via find_next_hop, and generate CoordsRequired/PathBroken error
signals on routing failure.

14 new tests covering decode errors, hop limit enforcement, local
delivery, cache warming for all session message types, single-hop and
multi-hop forwarding through live node chains, error signal generation,
and cache warming enabling subsequent routing. 375 tests pass.
2026-02-12 13:39:34 +00:00
Johnathan Corgan cc29c51cac Refactor node/handlers.rs and node/tests.rs into subdirectories
Split handlers.rs (986 lines) into handlers/ with 5 subfiles organized
by responsibility: rx_loop, encrypted, handshake, dispatch, timeout.

Split tests.rs (2350 lines) into tests/ with 4 subfiles: unit tests,
handshake integration, spanning tree convergence, and bloom filter tests.
Shared test helpers extracted to tests/mod.rs.

Visibility adjusted from pub(super) to pub(in crate::node) for handler
methods now two levels deep. Unused imports cleaned up in node/mod.rs.

All 316 tests pass, zero warnings.
2026-02-11 03:49:45 +00:00