mirror of https://github.com/jmcorgan/fips.git synced 2026-10-06 11:38:24 +00:00

T

fr34akyandJohnathan Corgan 813c50bb14 fix(transport): take the stream write off the caller's task

TCP, Tor, Nym and BLE wrote to their links from whatever task called
`send`. `write_all` on a stream blocks once the peer's receive window and
this node's send buffer are both full, and it blocks for as long as that
lasts — there is no bound on it. A peer that has stopped reading, or one
whose path has just changed medium, produces exactly that state.

The callers are the rx loop's tick handlers. The heartbeat sweep is one
of them, which is how this surfaced: filtering connection-oriented peers
out of the medium-change fan-out took the write out of that handler, but
not out of the sweep ten seconds behind it — same peer, same state. And
while the rx loop sits in that write it is not serving anything else, so
one unresponsive peer stalls every other peer's liveness, the forwarding
path, and the control socket.

Each connection now owns a writer task holding the write half, and
`send` enqueues onto a bounded channel. The only code that can await the
wire is a task with nothing else to do, so the property holds by
construction rather than by a timeout that has to be tuned against a
healthy slow link — a Tor circuit legitimately stalls for seconds, and
any budget short enough to protect the rx loop is short enough to kill
one of those.

`try_send`, not `send`: awaiting a full queue would reinstate the same
block one level up. A full queue means the writer has not drained a
frame in the time it took to offer 64, which is a peer that is not
receiving, so the send fails and the caller's existing retry and
liveness handling takes over — the same shape as the connect gate above
it, which already refuses rather than waits.

Frames are written whole by a single task, so ordering is preserved and
the half-written-frame hazard cannot arise: a write error takes the
connection down with it, and the peer sees a closed connection rather
than a frame it cannot resynchronise from. Teardown mirrors the receive
loop's existing contract exactly — the pool entry is removed and the
direction counter decremented only when the removal returned `Some`, so
a concurrent close or stop of the same address cannot double-count.

BLE was the worst of the four. `send_async` awaited the L2CAP write
while holding the connection-pool mutex, so a peer that stopped draining
its link blocked not only its own sender but every other BLE operation
behind that guard: connects, evictions, and each receive loop's
teardown. The other three only blocked the caller. The fix is the same
shape, and the pooled stream was already an `Arc` with a `Send` future,
so the writer task holds a clone and no generic surgery was needed.
Queue depth is 16 there rather than 64: a BLE link carries a fraction of
the throughput, so the same depth would be seconds of backlog rather
than a burst.

This also settles the Android backend without changing it. Its
`BleStream::send` pushes onto the embedder's queue and waits for a slot
rather than dropping, which was an unbounded wait on whatever task
called it. That call now happens only in the writer task, where waiting
is the job, and the layer above it is the connection's own bounded
queue, which fills and refuses without waiting on anything.

Two costs, both deliberate. The byte count `send` returns is now what
was queued rather than what reached the wire, which is the prediction
the UDP fast path already reports when it dispatches to the encrypt
workers; bytes actually written are recorded by the writer task as they
go. And the frame is copied into the queue, because `write_all` borrows
and a queue must own — one memcpy of at most an MTU, against an
unbounded stall.

Tor and Nym share `socks5::pool`, so the writer loop is written once
there and once for TCP, matching each transport's existing receive loop.

Both regression tests drive a peer that accepts and then never reads,
push far more than any buffer holds, and assert every send returns
promptly. Both are mutation-checked: replacing `try_send` with an
awaiting `send` fails the TCP one on the timeout, and reinstating the
write under the pool guard fails the BLE one, which also asserts the
pool stays lockable throughout.

What the evidence does and does not cover. The BLE change is exercised
through `MockBleIo`, not over the radio, so the argument that a stalled
radio link behaves like a stalled mock channel is reasoning rather than
measurement. The Android backend is `target_os = "android"` and there is
no NDK on the author's host, so it has no local compile evidence; the
`android-check` leg is the only one. Integration suites were run one at
a time rather than as a single pass, since the full runner exhausts
memory there: `chaos-tcp-mesh`, `chaos-congestion-stress` and
`chaos-churn-mixed-10` all pass.

Folded in on landing, all documentation and no behaviour change. Two doc
comments were left attached to the wrong function when the writer loop was
inserted above the receive loop, so `tcp_receive_loop` and BLE's
`receive_loop` each lost their own documentation to the new function above
them; both are moved back, and the TCP section banner now names both loops.
The Android backend's safety comment claimed `BleStream::send` is reached
from the writer task and from nowhere else, which is not so — `pubkey_exchange`
calls it too, safely, because it wraps the call in a timeout — so the comment
now names both callers and the reason each is bounded. And the netmon
fan-out's filter documented itself by the hazard it avoided, an unbounded
`write_all` reached from the rx loop; that hazard is gone, so the rationale
and the matching changelog clause now record that the filter has outlived it
and that widening the fan-out is open work left out here so the two changes
stay separable.

Co-authored-by: Johnathan Corgan <johnathan@corganlabs.com>

2026-09-08 17:07:23 +00:00

.config

Give the UDP microbench a reason and record the retry asymmetry

2026-07-23 13:48:11 +00:00

.github

fix(node): re-pin connected UDP sockets when the host changes medium

2026-09-06 22:28:43 +00:00

benches

Avoid allocations in routing next-hop selection

2026-08-10 01:58:13 +00:00

docs

fix(node): re-pin connected UDP sockets when the host changes medium

2026-09-06 22:28:43 +00:00

examples

Prepare the v0.5.0 release content

2026-08-30 10:42:59 +00:00

packaging

Correct the release documents the readiness pass found wrong

2026-09-06 20:20:56 +00:00

src

fix(transport): take the stream write off the caller's task

2026-09-08 17:07:23 +00:00

testing

fix(testing): claim the medium-change lab's subnets instead of pinning them

2026-09-07 23:37:07 +02:00

.dockerignore

build: produce every Linux artifact in a pinned container and check its floor

2026-09-05 23:34:05 +00:00

.git-blame-ignore-revs

Update .git-blame-ignore-revs with master format commit

2026-04-10 08:47:20 +00:00

.gitattributes

Fix snapshot-test CRLF mismatch on Windows runners

2026-05-03 23:30:18 +00:00

.gitignore

fix(node): re-pin connected UDP sockets when the host changes medium

2026-09-06 22:28:43 +00:00

build.rs

build: gate BLE on backend availability, and let an embedder install the radio

2026-08-26 07:58:58 +01:00

Cargo.lock

Release v0.5.1

2026-09-06 20:20:56 +00:00

Cargo.toml

Release v0.5.1

2026-09-06 20:20:56 +00:00

CHANGELOG.md

fix(transport): take the stream write off the caller's task

2026-09-08 17:07:23 +00:00

CONTRIBUTING.md

Prepare the v0.5.0 release content

2026-08-30 10:42:59 +00:00

flake.lock

packaging(nix): add a Nix flake for reproducible from-source builds

2026-06-17 16:36:38 +00:00

flake.nix

Add NixOS flake module (nixosModules.default) + overlay

2026-08-23 17:39:22 +01:00

LICENSE

Add open-source project scaffolding

2026-02-22 20:52:55 +00:00

PR-REVIEW.md

Prepare the v0.5.0 release content

2026-08-30 10:42:59 +00:00

README.md

Merge branch 'maint'

2026-09-06 20:37:39 +00:00

RELEASE-NOTES.md

Correct the release documents the readiness pass found wrong

2026-09-06 20:20:56 +00:00

rust-toolchain.toml

Add clippy to rust-toolchain.toml components

2026-05-02 02:44:47 +00:00

rustfmt.toml

Add rustfmt formatting policy and reformat codebase

2026-04-10 08:27:07 +00:00

SECURITY.md

Add a security policy with a private reporting channel

2026-08-13 15:56:25 +00:00

README.md

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, tunneling existing IPv6 traffic over the mesh or bypassing IP altogether and letting natively written applications communicate directly with each other. In either case all traffic between nodes is end-to-end encrypted and authenticated.

The mesh is self-organizing and permissionless. Any node can join and reach any other node without a central address registry, routing configuration, or coordination server. Peering between nodes can be manually configured or use auto-discovery.

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.

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. Support exists in OpenWrt for turning a router radio into a backhaul link and for creating an open access SSID so a phone or laptop can join without any configuration.

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. Applications written to the FIPS native API skip that layer entirely and address each other by public key, with no IPv6 emulation.

Features

The mesh

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.
Self-assigned cryptographic identity. secp256k1 / schnorr keypairs as node addresses; no registration, no central authority.
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.
(Optional) Nostr-mediated discovery and NAT traversal. Peers may publish endpoint adverts on public Nostr relays, exchange peering candidates, and establish direct paths through NATs using STUN-assisted hole punching. On the local network, mDNS LAN discovery finds peers directly without relays.

Getting traffic onto it

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.
Native datagram API. A local program moves bytes between two public keys over the mesh, addressing a peer as npub:port with no IPv6 emulation and no TUN device in the path. connect and bind take a key and a port, and from there it is ordinary socket calls.
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).
OpenWrt support. FIPS ships as an OpenWrt package. Routers run 802.11s between themselves as a bare L2 link, with FIPS supplying the encryption, authentication and routing over it. A second helper brings up an open !FIPS SSID, the same on every router, which a FIPS client joins over WiFi without configuration.

Running a node

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.
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.
Reproducible builds with toolchain pinning and SOURCE_DATE_EPOCH.

Quick start

Start from a released package. Every packaged platform in the table below gets an installer built and published per release, with checksums, on the releases page. Building from source produces the same artifacts and the same post-install state, so it is the path to take when you want to modify FIPS rather than run it.

On Debian or Ubuntu, download fips_<version>_amd64.deb (or _arm64.deb) and install it:

sudo dpkg -i fips_<version>_amd64.deb
sudo systemctl start fips fips-dns

This installs the daemon, CLI tools (fipsctl, fipstop), the fips-dns service that wires .fips name resolution into the host resolver, the optional fips-gateway service, systemd units, and a default /etc/fips/fips.yaml you can edit before starting. The package enables fips and fips-dns but starts neither, which is why the second command is there.

For macOS, Windows, FreeBSD, OpenWrt, the systemd tarball or a Nix flake, 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

To build the Debian package yourself rather than downloading it:

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

For the binaries alone, without an installer:

cargo build --release

Requires Rust 1.94.1+ (edition 2024). Linux, macOS, FreeBSD, and Windows run as standalone daemons. FreeBSD is packaged for x86_64 only; no aarch64 FreeBSD artifact is built or tested. Android is supported as an embedded crate rather than as a standalone daemon: a compile-gated library surface where the host app owns the TUN (a VpnService, for example) and reaches the built-in resolver through Node::dns_local_addr(). There is no Android daemon artifact and no host-app guide. Transport and feature availability varies by platform.

Feature	Debian/Ubuntu	Arch	NixOS	macOS	OpenWrt	FreeBSD	Android	Windows
UDP	✅	✅	✅	✅	✅	✅	✅	✅
TCP	✅	✅	✅	✅	✅	✅	✅	✅
Tor	✅	✅	✅	✅	✅	✅	❌	✅
Nym	✅	✅	✅	✅	❌	✅	❌	✅
Ethernet	✅	✅	✅	✅	✅	❌	❌	❌
BLE	✅	✅	✅	❌	❌	❌	✅	❌
Native API	✅	✅	✅	✅	✅	✅	❌	❌
Package format	`.deb`	AUR	flake	`.pkg`	`.ipk` / `.apk`	`.pkg`	❌	ZIP

A column records what builds and runs in a packaged daemon, FreeBSD on x86_64 only. Native API is the native datagram API, which is off by default; Windows cannot carry it, because it has no SCM_RIGHTS with which to pass a descriptor. Package format names the artifact you install, and a ❌ there means the platform ships none. Windows is the odd one: its ZIP is an archive you unpack yourself rather than a package an installer consumes, and there is no MSI.

Five of these columns are Linux: Debian/Ubuntu, Arch, NixOS, OpenWrt and Android. Linux is not one target. Debian, Ubuntu, Arch and NixOS are the same glibc build, and what differs is the packaging: Debian and Ubuntu take the same .deb, Arch takes fips from the AUR, and NixOS uses the Nix flake described below. Only the .deb is exercised by an install test, by the deb-install suite across debian12, debian13, ubuntu22, ubuntu24 and ubuntu26; neither the AUR package nor the flake is. That suite runs on every push and pull request, on x86_64, against a .deb built by the same pinned container as the released one. It does not run at a tag, and the arm64 package is install-tested by nothing: no workflow installs a published artifact, so the released packages are checked by hand. OpenWrt is a musl target rather than glibc, and it takes an .ipk on 24.x and earlier or an .apk on 25 and later; both carry the fips-mesh-setup and fips-ap-setup helpers.

Android records what compiles for aarch64-linux-android under the CI cross-check and nothing more: no transport in that column is exercised on a device or an emulator, so read it as "compiles", not "verified here". Being an embedded crate rather than a daemon platform, it has nothing to install, which is what its ❌ package format records. The BLE cell is narrower still: the transport compiles, but the radio behind it is supplied by the embedding application rather than by FIPS, and no part of that path is device-tested.

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 compiles on every glibc Linux target and on Android, and is excluded on musl. On glibc Linux, libdbus is a hard build prerequisite (sudo apt install libdbus-1-dev pkg-config on Debian / Ubuntu) — without it the build fails inside libdbus-sys rather than skipping BLE. The BlueZ daemon itself is a runtime dependency, not a build one. The OpenWrt ipk is a musl target, so it omits BLE.

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, 802.11s mesh backhaul and the open access SSID on OpenWrt, LAN gateway deployment and troubleshooting, MTU diagnostics, host aliases, persistent identity, unprivileged-user setup, UDP buffer tuning.
Reference — fips.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.
Release notes — per-version notes, including v0.5.1.

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, AUR, systemd tarball, OpenWrt ipk/apk,
              macOS .pkg, FreeBSD .pkg, Windows ZIP
examples/     Deployment examples (Nostr relay, K8s sidecar, macOS WireGuard)
testing/      Docker-based integration test harnesses + chaos simulation

Status & roadmap

FIPS is at v0.6.0-dev on the master branch. v0.5.1 is the current release, a maintenance release on the v0.5.x line that makes the Linux packages install and run on Debian 12 and Ubuntu 22.04, where every artifact from v0.3.0 through v0.5.0 installed and then could not start. v0.5.0 was the last feature release; this development line continues the testing-and-polishing track toward v0.6.0. 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. v0.5.0 added FreeBSD as a packaged platform, OpenWrt setup helpers for an 802.11s mesh backhaul and an open client SSID, an Android embedding interface, a native datagram API addressed by public key, and published node health with a bounded shutdown drain. 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).
Native datagram API for FIPS-aware applications (npub:port addressing without the IPv6-shim path): off by default, with a surface that may still change.
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 (including fipsctl probe for reachability diagnosis and fipsctl address for mesh-address derivation) and fipstop.
Reproducible builds with toolchain pinning and SOURCE_DATE_EPOCH.
Node lifecycle and health reporting (Starting, Running, Degraded, Failed, Draining) with a fatal start when no transport comes up and a bounded shutdown drain window.
OpenWrt setup helpers for an 802.11s mesh between routers (fips-mesh-setup) and for the open !FIPS client SSID (fips-ap-setup).
Linux (Debian, systemd tarball, OpenWrt .ipk and .apk, AUR), macOS (.pkg), FreeBSD (.pkg, x86_64 only), and Windows (ZIP, service) packaging.
Docker-based integration and chaos testing.

Near-term priorities

Security audit of the cryptographic protocols.

Longer-term

Packaged mobile applications: an Android host app, and iOS. The Android embedding interface ships today (see Building from source); what is absent is a packaged app on either platform.
Bandwidth-aware routing and QoS.
Protocol stability and a versioned wire format.
Published crate.

License

MIT — see LICENSE.