ddidderr
432d1d08d1
Add a small route-crate API that resolves a Windows network adapter GUID into its interface LUID and index. The TAP adapter discovery already gives us the NetCfgInstanceId GUID, and the route/metric work needs the corresponding IP interface identity before it can safely inspect or adjust TAP metrics. The implementation keeps GUID parsing local and dependency-free, then delegates the actual identity lookup to Windows IP Helper calls. Non-Windows builds expose the same API shape with a clear unsupported-platform error. Test Plan: - cargo fmt --check - cargo test --workspace - cargo clippy --workspace --all-targets -- -D warnings - cargo check -p lanparty-client-route --target x86_64-pc-windows-msvc - cargo clippy -p lanparty-client-route --target x86_64-pc-windows-msvc --all-targets -- -D warnings - git diff --check Refs: PLAN.md
softlan-vpn
Monorepo for a Layer 2 over QUIC LAN party bridge.
Workspace crates
lanparty-proto: shared frame format, MAC validation, MTU helpers.lanparty-ctrl: control-plane messages (join/hello/role/version).lanparty-obs: shared diagnostics/logging event models.lanparty-client-core: platform-agnostic client session state.lanparty-client-route: Windows relay-route inspection.lanparty-client-tap: TAP-Windows6 adapter discovery and frame I/O.lanparty-client-win: Windows TAP + route/metric handling binary.lanparty-gateway: Linux AF_PACKET gateway binary.lanparty-relay: public QUIC relay binary.
lanparty-proto
Transport-agnostic tunnel contract shared by all binaries:
- overlay datagram header encoding and decoding
- Ethernet frame header parsing
- MAC address parsing and identity validation
- QUIC datagram to TAP MTU budget helpers
lanparty-ctrl
Reliable control-plane schema shared by the QUIC stream handlers:
- endpoint hello messages with role, room, MAC, and datagram budget
- server welcome, reject, peer lifecycle, stats, and disconnect messages
- room-code, role/MAC, peer-id, and effective-MTU validation
- length-prefixed JSON control frames for reliable QUIC streams
lanparty-obs
Shared diagnostics and structured logging vocabulary:
- gateway/relay frame logs with MACs, ethertype, length, peer, and action
- tunnel counters shared by control messages and runtime diagnostics
- client connectivity/TAP diagnostics and user-facing status messages
lanparty-client-core
Platform-neutral remote client relay session:
- relay QUIC connection with pinned relay certificate trust
- client hello with room, virtual MAC, and datagram budget
- welcome/reject handling with assigned peer id and effective TAP MTU
- Ethernet frame send/receive helpers over QUIC DATAGRAM
lanparty-client-route
Windows route-table boundary:
- read-only best-route lookup for a relay destination IP
- selected source address, next hop, interface index/LUID, prefix, and metric
- interface index/LUID lookup from Windows network adapter GUIDs
- scoped host-route pinning for the relay IP on the pre-TAP interface
- non-Windows builds return a clear unsupported-platform error
lanparty-client-tap
Windows TAP adapter boundary:
- TAP-Windows6 adapter discovery from the Windows network adapter registry
\\.\Global\{NetCfgInstanceId}.tapdevice path construction- blocking Ethernet frame reads/writes through the TAP device handle
- TAP driver IOCTL helpers for media status, adapter MAC, and MTU
lanparty-relay
Public relay binary and relay-owned room state:
- QUIC endpoint binding and first-stream hello/welcome admission
- room admission for clients and gateways
- one gateway per room, duplicate client MAC rejection, and room limits
- stable effective room MTU chosen before Ethernet datagrams flow
- live Ethernet datagram forwarding with no ingress reflection
- L2 safety filters for jumbo, switch-control, DHCP-server, and IPv6-RA frames
- peer leave cleanup for room membership and MAC indexes
Build
cargo check --workspace
Relay
cargo run -p lanparty-relay -- --listen 443/udp --dev-cert-der-out relay-cert.der
--listen accepts either a socket address or a UDP port shorthand such as
443/udp. The relay binds a QUIC endpoint, accepts a control-stream hello,
replies with welcome or reject, and forwards live Ethernet QUIC datagrams
between accepted peers in the same room. It currently uses a generated
self-signed development certificate; --dev-cert-der-out writes that
certificate so the gateway and client can pin it in development. Production
certificate handling remains future work. Ethernet forwarding decisions are
logged with room, peer, MAC, ethertype, action, drop reason, and target count.
Gateway
cargo run -p lanparty-gateway -- \
--relay 203.0.113.10:443 \
--server-name lanparty-relay.local \
--relay-ca-cert relay-cert.der \
--room ROOM1 \
--interface eth0
The gateway connects to the relay as role = gateway, completes the
control-stream hello/welcome handshake, opens an AF_PACKET socket on the LAN
interface, and bridges Ethernet frames between the relay and wired LAN until
shutdown. It tracks remote-client source MACs seen from relay traffic and
periodically emits small CAM refresh frames so the physical switch keeps those
MACs associated with the gateway port.
Windows Client
cargo run -p lanparty-client-win -- \
--relay 203.0.113.10:443 \
--server-name lanparty-relay.local \
--relay-ca-cert relay-cert.der \
--room ROOM1
The Windows client binary currently connects to the relay as role = client
with a generated locally administered virtual MAC persisted in
lanparty-client-identity.json, completes the control-stream hello/welcome
handshake, pins a host route for the relay IP on the current pre-TAP interface,
and then bridges Ethernet frames between the relay and the first TAP-Windows6
adapter until shutdown.
--virtual-mac can still override the stored identity for manual testing. On
Windows it marks the TAP media connected and reports the driver MAC/MTU before
forwarding frames. Default-route takeover neutralization and automatic TAP
MAC/MTU configuration are not wired yet.