mirror of
https://github.com/jmcorgan/fips.git
synced 2026-10-05 19:18:25 +00:00
Johnathan Corgan
28f9fc007a
5353 is the mDNS port, which the daemon's LAN rendezvous, Avahi and systemd-resolved can hold. On an OpenWrt access point with the gateway enabled, the gateway lost the port to the daemon's mDNS responder and dnsmasq sent .fips queries to a responder that does not answer them. 5365 is unassigned by IANA and not used by any common resolver. The OpenWrt init script now points dnsmasq at the port gateway.dns.listen actually sets, falling back to the new default, and when it swaps the .fips forwarding it clears every loopback .fips entry rather than four fixed ones, so a stale entry for an old or custom port does not linger. Forwards to other hosts and other domains are kept. The shipped OpenWrt config and the example config leave the listen line at the default. fips.yaml is a conffile on OpenWrt, and fips-ap-setup edits it, so routers that set up an access point would keep the old explicit listen: "[::1]:5353" across an upgrade and stay broken after the default moved. The first-boot setup script, which every install and upgrade path runs before the services start, now rewrites that exact shipped line to the line a fresh install ships and logs that it did; any other value is left as configured. The script is sourced rather than executed on the SDK-feed and sysupgrade paths, so the migration runs last, cannot end the script early and cannot change its exit status. The script also removes stale loopback .fips forwarding entries for port 5353. The gateway warns at startup when it is configured on 5353, whether or not the bind succeeds, since an mDNS responder can take the port later. The OpenWrt scenario harness checks the port the init script reads, that its default matches the gateway's, and the swap's cleanup against a uci stub. It also runs the real setup script executed by both package managers' upgrade scripts and sourced in a subshell, and checks the negative, missing-file, repeat-run and stale-entry cases. The dns-resolver and deb-install harnesses check that the gateway binds the new default.
FIPS Design
Architectural and protocol-level explanations for FIPS — the why and the how behind the wire and the system. For wire formats and configuration keys, see reference/. For task recipes, see how-to/. For end-to-end lessons, see tutorials/.
Reading Order
Start with fips-concepts.md for the novice-friendly framing of what FIPS is and why, then move to fips-architecture.md for the protocol stack, identity model, and two-layer encryption walkthrough. From there, follow the protocol stack from bottom to top. After the stack, fips-mesh-operation.md explains how the pieces work together at runtime. Cross-cutting and supporting documents cover specific subsystems in detail.
Foundations
| Document | Description |
|---|---|
| fips-concepts.md | What FIPS is, why it exists, mental model |
| fips-architecture.md | Protocol stack, identity, two-layer encryption |
| fips-prior-work.md | Designs and protocols FIPS builds on |
Protocol Stack
| Document | Description |
|---|---|
| fips-transport-layer.md | Transport layer: datagram delivery over arbitrary media |
| fips-mesh-layer.md | FIPS Mesh Protocol (FMP): peer authentication, link encryption, forwarding |
| fips-session-layer.md | FIPS Session Protocol (FSP): end-to-end encryption, sessions |
| fips-ipv6-adapter.md | IPv6 adaptation: TUN interface, DNS, MTU enforcement |
| fips-native-api.md | Native datagram API: pubkey-addressed flows over FSP, and what it is instead of the TUN path |
Cross-Cutting
| Document | Description |
|---|---|
| fips-mmp.md | Metrics Measurement Protocol (link + session) |
| fips-mtu.md | Path MTU model, encapsulation overhead, PMTUD |
| fips-security.md | fips0 interface threat model and default-deny baseline |
Mesh Behavior
| Document | Description |
|---|---|
| fips-mesh-operation.md | How the mesh operates: routing, discovery, error recovery |
| fips-nostr-discovery.md | Optional Nostr-mediated peer discovery and UDP NAT hole-punch |
| port-advertisement-and-nat-traversal.md | Nostr-signaled port advertisement and UDP NAT-traversal protocol; generic, with FIPS as an example implementation |
Deeper Dives
| Document | Description |
|---|---|
| fips-spanning-tree.md | Spanning tree algorithms: root discovery, parent selection, coordinates |
| fips-bloom-filters.md | Bloom filter properties: FPR analysis, size classes, split-horizon |
| spanning-tree-dynamics.md | Spanning tree walkthroughs: convergence scenarios, worked examples |
Adjacent Components
| Document | Description |
|---|---|
| fips-gateway.md | fips-gateway service: outbound (LAN-to-mesh) DNS-proxy + virtual-IP NAT and inbound (mesh-to-LAN) port-forwarding, sharing one nftables table |