Every member now also derives an IPv4 address, from the same inputs as its
IPv6 one, into 100.64.0.0/10 by default. The range is configurable and IPv4
can be turned off with --no-ipv4.
IPv4 is honestly weaker than IPv6 here and the code says so. A 64 bit
interface identifier makes an IPv6 collision impossible in practice; IPv4
has nothing like that room, and in a /10 with 50 members two will derive the
same address about 0.03% of the time. A mesh with no coordinator cannot
allocate around that, so a collision is detected and resolved instead: the
member whose public key sorts lower keeps the address, a rule every member
computes identically and therefore agrees on. The other keeps IPv6 and is
flagged in the status. IPv6 always works; IPv4 almost always works and
degrades predictably.
Routing and address-ownership enforcement now cover both families: a packet
goes to the peer that owns its destination, and a decrypted packet is
dropped unless its source is an address derived for the peer that sent it,
IPv4 included.
Six new tests, among them a real IPv4 packet crossing a tunnel next to an
IPv6 one, a spoofed IPv4 source being dropped, and an IPv6-only overlay.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The first IP plugin, built on the data plane boundary the core already had.
Plugin:
- one X25519 key per network in the plugin's own wireguard.sqlite, separate
from the iroh identity and from the network secret; a damaged store is an
error, never a silently regenerated identity
- deterministic IPv6 ULA overlay: every member derives the same /64 from the
network id and its own /128 from its WireGuard public key, so no
coordinator allocates addresses
- AllowedIPs are derived locally, never taken from a peer's announcement, so
a member cannot claim another member's overlay address; a mismatched claim
is rejected
- bounded, versioned, validated announcement carried as the existing opaque
capability payload, which the core still never parses
- each agent builds its own full-mesh configuration (N-1 peers) and
reconciles on every change and on a timer, repairing drift
- WireguardBackend abstraction: RecordingBackend in memory, and WgToolBackend
driving real wg/ip on Linux, split into a pure planner plus parsers and a
thin executor so everything interesting is testable without root
Core, three generic additions the plugin needed:
- IpPlugin::on_network_activated, so per-network state is ready before peers
- PluginContext for re-announcements and error reports from plugin tasks,
with errors counted by the owning network runtime
- IpPlugin::shutdown, awaited with a grace period, so system objects go away
94 tests pass offline with no privileges: 35 new WireGuard unit tests and 12
integration tests over real iroh connections. The real wg/ip backend needs
root and is behind --ignored in tests/wireguard_system.rs; it was not run.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
tsunagiandClaude Opus 5