Johnathan Corgan
717be3d960
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
FIPS: Free Internetworking Peering System
A distributed, decentralized network routing protocol for mesh nodes connecting over arbitrary transports.
Status: Experimental / Pre-release
FIPS is under active development. The protocol and APIs are not stable. Expect breaking changes.
Overview
FIPS is a self-organizing mesh network that operates natively over a variety of physical and logical media — local area networks, Bluetooth, serial links, radio, or the existing internet as an overlay. Nodes generate their own identities, discover each other, and route traffic without any central authority or global topology knowledge.
FIPS uses Nostr keypairs (secp256k1/schnorr) as native node identities, making every Nostr user a potential network participant. Nodes address each other by npub, and the same cryptographic identity used in the Nostr ecosystem serves as both the routing address and the basis for end-to-end encrypted sessions across the mesh.
Features
- Self-organizing mesh routing — spanning tree coordinates and bloom filter candidate selection, no global routing tables
- Multi-transport — UDP/IP overlay today; designed for Ethernet, Bluetooth, serial, radio, and Tor
- Noise encryption — hop-by-hop link encryption plus independent end-to-end session encryption
- Nostr-native identity — secp256k1 keypairs as node addresses, no registration or central authority
- IPv6 adaptation — TUN interface maps npubs to fd00::/8 addresses for unmodified IP applications
- Metrics Measurement Protocol — per-link RTT, loss, jitter, and goodput measurement
- Operator visibility —
fipsctlcontrol socket interface for runtime inspection of peers, links, sessions, tree state, and metrics - Zero configuration — sensible defaults; a node can run with no config file
Quick Start
Requirements
- Rust 1.85+ (edition 2024)
- Linux (TUN interface requires
CAP_NET_ADMINor root)
Build
git clone https://github.com/jmcorgan/fips.git
cd fips
cargo build --release
Run
# With default configuration (ephemeral identity, default ports):
sudo ./target/release/fips
# With a configuration file:
sudo ./target/release/fips -c fips.yaml
See docs/design/fips-configuration.md for the full configuration reference.
Multi-node Testing
See testing/ for Docker-based integration test harnesses including static topology tests and stochastic chaos simulation.
Documentation
Protocol design documentation is in docs/design/, organized as a layered protocol specification. Start with fips-intro.md for the full protocol overview.
Project Structure
src/ Rust source (library + fips/fipsctl binaries)
docs/design/ Protocol design specifications
testing/ Docker-based integration test harnesses
benches/ Criterion benchmarks
License
MIT — see LICENSE.