Johnathan Corgan 8162b7d9fc Cover the capture writer's failure path and split its flush cycle
The mesh rehearsal could not exercise the write-error stop at all, and
that is not a gap in the rehearsal. Removing the sink file leaves the
writer's descriptor valid, so writes keep succeeding into the unlinked
inode and the capture runs on; mounting a tiny filesystem inside the test
container is refused outright. So the terminal state added for a failing
sink had no coverage from either direction.

Split one flush cycle out of the writer loop as a function returning what
it decided, so the loop owns the waiting and the state transition while
the decision is testable on its own. A sink that fails every write now
drives the error outcome directly, and a working sink is asserted to
continue so the first test cannot pass for a writer that always stops.
The residual gap is recorded at the test: what is covered is that an
error from the sink produces the error outcome rather than the cap
outcome, not that a real full disk reaches that branch.

The rehearsal itself was otherwise clean on a live three-node mesh. The
header carries node, build, platform, tick period and the reading
caveats; every step reports every interval; stopping returns in 53 ms
rather than waiting out the flush interval; an idle status reports no
path and no bytes; arming twice is refused naming the active file; an
unwritable directory fails the command; and the node kept serving
throughout. On an idle node the entry gap sits at one tick period and
arm starvation reads about 1.4 ms, which is small but not zero, so the
measurement is live rather than degenerate.
2026-07-28 01:30:11 +00:00
2026-02-22 20:52:55 +00:00

FIPS: Free Internetworking Peering System

banner License: MIT Rust Status

A self-organizing encrypted mesh network built on Nostr identities, capable of operating over arbitrary transports without central infrastructure.

FIPS is under active development. The protocol and APIs are not yet stable. See Status & roadmap below.

What FIPS does

A machine running FIPS becomes a node in the mesh with a self-generated cryptographic identity (a Nostr keypair). There are two equally-supported deployment modes.

As an overlay on top of existing IP networks, FIPS lets your node reach any other FIPS node wherever it sits — behind a NAT, on a different ISP, on a phone over cellular, on a laptop with only Bluetooth in range, or behind a Tor onion. The mesh forwards IPv6 traffic transparently and end-to-end encrypted, with no central VPN concentrator or coordinating server.

Ground up over raw Ethernet, WiFi, or Bluetooth, FIPS provides a complete permissionless network without any pre-existing IP infrastructure, ISP, or DNS. Any node that joins the link gets routable IPv6 addresses, peer discovery, and a path to every other node automatically.

Either way, existing networking software runs over it unchanged — SSH, HTTP servers, file transfer, anything IPv6-native works the same way it would on a local network.

Features

  • Self-organizing mesh routing. Spanning-tree coordinates with bloom-filter-guided discovery; no global routing tables, no flooding.
  • Multi-transport. UDP, TCP, Ethernet, Tor, Nym, and Bluetooth (BLE L2CAP) ship today; transports compose on a single mesh and a node may run several at once.
  • Two-layer encryption. Noise IK between peers (hop-by-hop) and Noise XK between mesh endpoints (independent end-to-end), with periodic rekey for forward secrecy.
  • Nostr-native identity. secp256k1 / schnorr keypairs as node addresses; self-generated, no registration, no central authority.
  • IPv6 adapter. A TUN interface maps each remote npub to an fd00::/8 address, so unmodified IPv6 software reaches mesh peers as <npub>.fips. Built-in .fips DNS resolver, with optional static name mapping via /etc/fips/hosts.
  • Nostr-mediated discovery and NAT traversal. Peers publish endpoint adverts on public Nostr relays, exchange candidates via NIP-59 gift-wrapped offers and answers, and establish direct paths through NATs using STUN-assisted hole punching. On the local network, mDNS LAN discovery finds peers directly without relays.
  • LAN gateway. Optional fips-gateway service folds an entire unmodified LAN into the mesh: outbound (LAN clients reach mesh destinations through a DNS-allocated virtual IPv6 pool and nftables NAT) and inbound (LAN-side services exposed to the mesh through 1:1 port forwards).
  • Per-link metrics. RTT, loss, jitter, and goodput on every hop, plus mesh-size estimation, via the Metrics Measurement Protocol.
  • ECN congestion signaling. Hop-by-hop CE-flag relay with RFC 3168 IPv6 marking and transport kernel-drop detection.
  • Mesh-interface security baseline. Optional default-deny nftables policy for fips0 shipped as a packaged conffile (/etc/fips/fips.nft) with an operator drop-in directory (/etc/fips/fips.d/) and a disabled-by-default fips-firewall.service. The baseline polices only the mesh interface, leaving Docker, Tor, and the host firewall untouched.
  • Operator visibility. fipsctl CLI for control and inspection with time-series stats history queryable for any metric, fipstop TUI for live status with inline sparkline dashboards, and a JSON-line control socket on each binary for direct programmatic access.
  • Reproducible builds with toolchain pinning and SOURCE_DATE_EPOCH.

Quick start

The shortest path on Debian / Ubuntu:

git clone https://github.com/jmcorgan/fips.git
cd fips
cargo install cargo-deb
cargo deb
sudo dpkg -i target/debian/fips_*.deb
sudo systemctl start fips

This installs the daemon, CLI tools (fipsctl, fipstop), the optional fips-gateway service, systemd units, and a default /etc/fips/fips.yaml you can edit before starting.

For macOS, Windows, OpenWrt, the systemd tarball, a Nix flake, or a from-source build, see docs/getting-started.md for the full multi-platform installation guide.

To join a live mesh and reach your first peer, follow the new-user tutorial progression starting at docs/tutorials/join-the-test-mesh.md.

Building from source

cargo build --release

Requires Rust 1.94.1+ (edition 2024). Linux, macOS, and Windows run as standalone daemons; Android is supported as an embedded library (the host app owns the TUN, e.g. a VpnService). Transport availability varies by platform.

Transport Linux macOS Windows Android OpenWrt
UDP
TCP
Ethernet
Tor
Nym
BLE

On Linux, a source build requires libclang — the LAN gateway's nftables bindings are generated by bindgen at build time, which needs libclang.so on the build host. Install it before building (sudo apt install libclang-dev on Debian / Ubuntu); without it the build fails inside the rustables crate with an "Unable to find libclang" error. This is a build-time prerequisite only — it is not a runtime dependency, and the pre-built .deb artifacts do not need it.

BLE is optional and, on Linux, requires BlueZ and libdbus (sudo apt install bluez libdbus-1-dev on Debian / Ubuntu). It is gated on a build-script probe — install the dependencies first and the cargo build line above picks it up. The OpenWrt ipk omits BLE because libdbus is not available on the target.

Nym (mixnet) transport builds on all desktop platforms. The OpenWrt is provisional, pending verification of nym-socks5-client availability on the target; it will flip to only if confirmed buildable there.

Alternatively, the repo ships a Nix flake: nix develop drops you into a shell with the pinned toolchain and every build prerequisite (libclang, dbus, pkg-config) already provided, and nix build .#fips builds all four binaries with no host setup. See the Nix / NixOS section of packaging/README.md.

Documentation

docs/ is organised by reader purpose:

  • Tutorials — hand-held walk-throughs from a fresh install through to a participating mesh node, plus advanced deployments (gateway on OpenWrt, hosting services, ground-up two-device mesh).
  • How-to guides — operator recipes for specific tasks: firewall activation, Nostr discovery, Tor onion service, Bluetooth peering, LAN gateway deployment and troubleshooting, MTU diagnostics, host aliases, persistent identity, unprivileged-user setup, UDP buffer tuning.
  • Referencefips.yaml configuration, wire formats, control-socket protocol, CLI references for each binary, security posture matrix, Nostr events catalog, transport statistics inventory.
  • Design — protocol-level architecture and layer specifications. Start with fips-concepts.md for the framing, then fips-architecture.md for the protocol stack.

If you want to contribute, see CONTRIBUTING.md and testing/README.md.

Examples

  • examples/sidecar-nostr-relay/ — Run a strfry Nostr relay reachable exclusively over the FIPS mesh. The relay container shares the FIPS sidecar's network namespace and is isolated from the host network.
  • examples/sidecar-nostr-mixnet-relay/ — Single-container demo of FIPS peering through a mixnet (implemented with Nym): the FIPS daemon, the mixnet proxy, and a strfry Nostr relay all in one isolated container, with the direct route to the peer firewalled off so traffic provably crosses the mixnet.
  • examples/k8s-sidecar/ — Run FIPS as a Kubernetes Pod sidecar. The sidecar creates fips0 in the Pod's shared network namespace so every other container in the Pod gets mesh access without modification.
  • examples/wireguard-sidecar-macos/ — Reach the FIPS mesh from a macOS host through a local Docker container over a WireGuard tunnel. Only traffic destined for fd00::/8 transits the sidecar; regular internet traffic continues to use the host network.

Project structure

src/          Rust source: library + fips, fipsctl, fipstop, fips-gateway binaries
docs/         Documentation: tutorials, how-to, reference, design
packaging/    Debian, macOS .pkg, Windows ZIP, OpenWrt ipk, AUR, systemd tarball
examples/     Deployment examples (Nostr relay, K8s sidecar, macOS WireGuard)
testing/      Docker-based integration test harnesses + chaos simulation

Status & roadmap

FIPS is at v0.5.0-dev on the master branch. v0.4.1 has shipped; this development line continues the testing-and-polishing track toward v0.5.0. The core protocol works end-to-end over UDP, TCP, Ethernet, Tor, Nym, and Bluetooth on a global, public test mesh of thousands of nodes. v0.4.0 added the Nym mixnet transport and mDNS LAN discovery alongside the existing Nostr-mediated peer discovery, UDP NAT traversal, peer ACL, and packaging hardening. New wire-format work continues to be staged on the next branch for the subsequent release line.

What works today

  • Spanning-tree construction with greedy coordinate routing.
  • Bloom-filter-guided destination discovery (no flooding, single-path with retry).
  • Two-layer Noise encryption (IK at the link, XK at the session) with periodic hitless rekey for forward secrecy at both layers.
  • Persistent or ephemeral node identity with key-file management.
  • IPv6 TUN adapter with built-in .fips DNS resolver and multi-backend auto-configuration (systemd dns-delegate, systemd-resolved, dnsmasq, NetworkManager).
  • Static hostname mapping (/etc/fips/hosts) with auto-reload.
  • Per-link metrics (RTT, loss, jitter, goodput) and mesh size estimation.
  • ECN congestion signaling (hop-by-hop CE relay, IPv6 CE marking, kernel-drop detection).
  • UDP, TCP, Ethernet, Tor, Nym (mixnet), and BLE transports (BLE via L2CAP CoC with per-link MTU negotiation).
  • Nostr-mediated overlay endpoint discovery and UDP hole punching for NAT traversal, plus mDNS LAN discovery for local peers.
  • LAN gateway (fips-gateway) with both outbound (LAN-to-mesh) and inbound (mesh-to-LAN port-forwarding) modes.
  • Peer ACL: per-npub allow / deny admission control at the link layer; opt-in mesh-firewall baseline at fips0 ingress.
  • Runtime inspection and peer management via fipsctl and fipstop.
  • Reproducible builds with toolchain pinning and SOURCE_DATE_EPOCH.
  • Linux (Debian, systemd tarball, OpenWrt, AUR), macOS (.pkg), and Windows (ZIP, service) packaging.
  • Docker-based integration and chaos testing.

Near-term priorities

  • Native API for FIPS-aware applications (npub:port addressing without the IPv6-shim path).
  • Security audit of the cryptographic protocols.

Longer-term

  • Mobile platform support.
  • Bandwidth-aware routing and QoS.
  • Protocol stability and a versioned wire format.
  • Published crate.

License

MIT — see LICENSE.

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