Johnathan Corgan
2d0e8de8c8
PeerRecvDrain::drop previously called std::thread::join on the worker
thread synchronously. The worker uses packet_tx.blocking_send on a
tokio mpsc Sender, which internally parks the worker via
tokio::block_on on the same current_thread runtime that drives
rx_loop. Calling join from inside remove_active_peer (which runs on
the runtime thread, the runtime's sole driver) created a circular
wait:
- rx_loop blocks in libc futex via Thread::join
- the worker being joined cannot observe the stop flag because the
runtime that polls it is the very thread now blocked joining it
- all other PeerRecvDrain workers park on the same runtime via
block_on, so a single peer's removal wedges every worker on the
daemon
The /proc snapshot from a production wedge showed exactly this
shape: 107 of 108 threads in futex_do_wait, 101 of them named
fips-peer-drain. fipsctl became unresponsive (EAGAIN on control
socket), SIGTERM was ignored, and Docker SIGKILLed the container
after the 10 s grace period. Two confirmed wedges on the public
test deployment (52 min and 23 min uptime), plus a third on the
admission-gate-Msg2-silent-drop build at 2 min 21 sec — all ending
with the identical "Peer removed and state cleaned up
tree_changed=false" final log line preceding total silence.
Fix: detach the std::thread instead of joining. The stop flag plus
self-pipe write already signal the worker to exit; the worker's
kernel-level libc::poll inside the drain loop sees the wake, checks
the flag, exits, and the OS reclaims the thread state independently
of the JoinHandle being dropped.
The trigger was statistically amplified by aggressive multi-npub-
from-one-NAT peer reconnect patterns at the moment of the 30 s
link-dead-timeout peer-removal, but not bounded to them. Any
peer whose disconnect happens with the per-peer drain worker
parked in block_on can fire the bug. The admission-gate work
that landed earlier in this branch line compressed more handshake
work per rx_loop tick, increasing the rate at which workers are
parked in block_on and so reducing time-to-wedge — but the
underlying bug pre-dated the admission gate and pre-dated this
fix branch.
The deployed wedged daemon is mitigated operationally by blocking
the trigger IP at the host firewall; this commit removes the bug
class entirely.
FIPS: Free Internetworking Peering System
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, 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::/8address, so unmodified IPv6 software reaches mesh peers as<npub>.fips. Built-in.fipsDNS 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.
- LAN gateway. Optional
fips-gatewayservice 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
fips0shipped as a packaged conffile (/etc/fips/fips.nft) with an operator drop-in directory (/etc/fips/fips.d/) and a disabled-by-defaultfips-firewall.service. The baseline polices only the mesh interface, leaving Docker, Tor, and the host firewall untouched. - Operator visibility.
fipsctlCLI for control and inspection with time-series stats history queryable for any metric,fipstopTUI 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, 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 are supported; transport availability varies by platform.
| Transport | Linux | macOS | Windows | OpenWrt |
|---|---|---|---|---|
| UDP | ✅ | ✅ | ✅ | ✅ |
| TCP | ✅ | ✅ | ✅ | ✅ |
| Ethernet | ✅ | ✅ | ❌ | ✅ |
| Tor | ✅ | ✅ | ✅ | ✅ |
| BLE | ✅ | ❌ | ❌ | ❌ |
On Linux, BLE requires BlueZ and libdbus
(sudo apt install bluez libdbus-1-dev on Debian / Ubuntu) and 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.
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.
- Reference —
fips.yamlconfiguration, 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/k8s-sidecar/ — Run FIPS as
a Kubernetes Pod sidecar. The sidecar creates
fips0in 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::/8transits 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 v0.3.0. The core protocol works end-to-end over
UDP, TCP, Ethernet, Tor, and Bluetooth on a small live mesh of
deployed nodes. v0.3.0 is the testing-and-polishing track for
everything accumulated since v0.2.0 on the v0.2.x wire format —
Nostr-mediated peer discovery, UDP NAT traversal, peer ACL, the
DNS-responder fix, packaging hardening, and discovery rate-limit
retuning. New wire-format work is staged on the next branch for
the post-v0.3.0 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
.fipsDNS 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, and BLE transports (BLE via L2CAP CoC with per-link MTU negotiation).
- Nostr-mediated overlay endpoint discovery and UDP hole punching for NAT traversal.
- 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
fips0ingress. - Runtime inspection and peer management via
fipsctlandfipstop. - 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.