Add an IPv4 helper lib (parse, netmask, cidr, overlap) and derive
router.lans.<name>.ipv4.subnet from address and prefixLength instead of
requiring it twice. New assertions reject invalid addresses, DHCP pools that
are reversed, outside the subnet or contain the router address, and
overlapping LANs.
Add `lib` unit tests and an `assertions` check that evaluates broken configs
and compares the exact error messages.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
driverInteractive uses the full QEMU build, which opens a GUI window per VM.
Pass -display none for the interactive nodes so `nix run .#lab` stays in the
terminal.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
router.* schema (wan, lans, dns.forwarders) compiled to systemd-networkd,
a generated nftables ruleset with NAT, Kea DHCPv4 and Unbound, plus build-time
assertions against lock-out and interface conflicts.
tests/basic.nix is a three-node VM test (upstream/router/client) covering WAN
DHCP, LAN DHCP and DNS, NAT, WAN-deny and LAN SSH/ping. `nix run .#lab` boots
the same topology in tmux with one console pane per VM and the driver REPL.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
nilsandClaude Sonnet 5.5