Johnathan Corgan
1cc069f1a2
The TUN adapter, the .fips DNS responder, ICMPv6 generation and TCP MSS clamping are the host-side IPv6 plane, but the code was split between src/upper and inline bodies in the node's session handler and lifecycle. Gather it into one module, src/ipv6tun, and reduce its calls into the rest of the crate to a small explicit set. This prepares the TUN adapter to run later as a separate daemon over the native API, and gives embedders one place to find the host-side surface. Behaviour is unchanged apart from log target names. - Rename src/upper to src/ipv6tun. A `pub use ipv6tun as upper;` alias keeps every crate::upper:: and fips::upper:: path resolving, so no consumer has to change. - Move hosts.rs whole to src/hosts.rs, a top-level public module: the hosts file also serves peer display names, the peer ACL and fipsctl, so it is not host-side only. ipv6tun re-exports it for the old path. - Move the DNS socket helpers (dual-stack bind, IPV6_RECVPKTINFO, interface index lookup) from Node into ipv6tun::dns, unchanged. Node::mesh_ifindex, which reads the live TUN device name, becomes Handles::mesh_ifindex. - Move ICMPv6 Destination Unreachable and Packet Too Big sending into ipv6tun::icmp behind IcmpContext, which borrows the TUN channel, our address and the Packet Too Big rate limiter for one use. Packet Too Big is still rate limited and Destination Unreachable still is not. The discovery lookup timeout hands its queued packets over as one no-route report. - Split handle_tun_outbound. The host-side half, in ipv6tun::outbound, validates the packet, makes both Packet Too Big decisions and sends the ICMPv6 replies, reaching the mesh through a small Mesh trait Node implements. The mesh-side half, Node::send_outbound, stays with the pending queue. The checks run in the same order with the same thresholds, and Node::handle_tun_outbound remains the entry point. - Move the TUN and DNS child start and stop bodies into ipv6tun::lifecycle, and gather their nine supervisor fields and the node's TUN device name into one Handles struct the supervisor holds. The supervisor arms, their order and the child-exit reporting are unchanged. A TUN still counts as up when it has a device name, so an app-owned TUN produces no TUN teardown, and DNS counts as up while its task runs. The node passes a new peer-alias base to the running responder through Handles::publish_aliases. Node::tun_name, tun_tx, dns_local_addr and enable_app_owned_tun keep their behaviour; tests install a TUN sender through a test-only Node::install_tun. Tracing targets follow module paths, so lines from the moved code now log under fips::ipv6tun::* and fips::hosts instead of fips::upper::*, fips::node::lifecycle and fips::node::handlers::session. Update the RUST_LOG example in the MTU diagnosis guide and the test harness filters that relied on the old targets, and note the rename in the changelog.
FIPS Documentation
FIPS (Free Internetworking Peering System) is a self-organizing encrypted mesh network built on Nostr identities, capable of operating over arbitrary transports — local networks, the public internet, Tor, Bluetooth, or point-to-point links — without central infrastructure.
With FIPS, your machine becomes a node in the mesh with a self-generated cryptographic identity. There are two ways to deploy it.
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.
From the 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.
New to FIPS? Start with the Getting Started guide.
Documentation Sections
Tutorials
If you are starting from scratch and want a guided path to a working mesh, go here.
How-To Guides
If you have a specific task in mind — enabling a feature, deploying a component, diagnosing a problem — go here.
Reference
If you need to look up wire formats, configuration keys, command flags, or counter inventories, go here.
Design
If you want to understand how the mesh self-organizes, why FIPS makes the choices it does, or how the pieces fit together, go here.
Releases
If you want the notes for a particular version — what changed, what broke, and what to do about it on upgrade — go here.