ddidderr
2a8e6467c4
The Windows client now verifies that the relay path still uses the pinned host route after the TAP adapter is activated, and keeps checking that invariant while frames are being bridged. If Windows starts choosing a different prefix, next hop, or interface for the relay IP, the client exits instead of silently letting the tunnel route itself through the TAP side. This closes the remaining detection half of the route-protection startup flow from PLAN.md. The previous commits installed the pre-TAP host route, scoped TAP metrics, and disabled TAP default routes; this commit proves those protections are still winning after TAP activation and catches later DHCP-driven route changes during the session. The route crate now exposes small helpers for route-interface identity and host route matching so the client does not duplicate route-prefix semantics inline. The full Windows client target check still cannot complete on this Linux host: `ring` fails while compiling for `x86_64-pc-windows-msvc` because the Windows C header `assert.h` is unavailable, before `lanparty-client-win` is typechecked. The independent Windows-target route crate checks do pass. 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
149 lines
5.7 KiB
Markdown
149 lines
5.7 KiB
Markdown
# softlan-vpn
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Monorepo for a Layer 2 over QUIC LAN party bridge.
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## Workspace crates
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- `lanparty-proto`: shared frame format, MAC validation, MTU helpers.
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- `lanparty-ctrl`: control-plane messages (join/hello/role/version).
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- `lanparty-obs`: shared diagnostics/logging event models.
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- `lanparty-client-core`: platform-agnostic client session state.
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- `lanparty-client-route`: Windows relay-route inspection.
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- `lanparty-client-tap`: TAP-Windows6 adapter discovery and frame I/O.
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- `lanparty-client-win`: Windows TAP + route/metric handling binary.
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- `lanparty-gateway`: Linux AF_PACKET gateway binary.
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- `lanparty-relay`: public QUIC relay binary.
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### `lanparty-proto`
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Transport-agnostic tunnel contract shared by all binaries:
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- overlay datagram header encoding and decoding
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- Ethernet frame header parsing
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- MAC address parsing and identity validation
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- QUIC datagram to TAP MTU budget helpers
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### `lanparty-ctrl`
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Reliable control-plane schema shared by the QUIC stream handlers:
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- endpoint hello messages with role, room, MAC, and datagram budget
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- server welcome, reject, peer lifecycle, stats, and disconnect messages
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- room-code, role/MAC, peer-id, and effective-MTU validation
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- length-prefixed JSON control frames for reliable QUIC streams
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### `lanparty-obs`
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Shared diagnostics and structured logging vocabulary:
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- gateway/relay frame logs with MACs, ethertype, length, peer, and action
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- tunnel counters shared by control messages and runtime diagnostics
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- client connectivity/TAP diagnostics and user-facing status messages
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### `lanparty-client-core`
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Platform-neutral remote client relay session:
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- relay QUIC connection with pinned relay certificate trust
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- client hello with room, virtual MAC, and datagram budget
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- welcome/reject handling with assigned peer id and effective TAP MTU
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- Ethernet frame send/receive helpers over QUIC DATAGRAM
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### `lanparty-client-route`
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Windows route-table boundary:
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- read-only best-route lookup for a relay destination IP
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- selected source address, next hop, interface index/LUID, prefix, and metric
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- interface index/LUID lookup from Windows network adapter GUIDs
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- scoped IP interface metric overrides with restore-on-drop behavior
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- scoped default-route suppression with restore-on-drop behavior
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- scoped host-route pinning for the relay IP on the pre-TAP interface
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- non-Windows builds return a clear unsupported-platform error
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### `lanparty-client-tap`
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Windows TAP adapter boundary:
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- TAP-Windows6 adapter discovery from the Windows network adapter registry
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- `\\.\Global\{NetCfgInstanceId}.tap` device path construction
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- blocking Ethernet frame reads/writes through the TAP device handle
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- TAP driver IOCTL helpers for media status, adapter MAC, and MTU
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### `lanparty-relay`
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Public relay binary and relay-owned room state:
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- QUIC endpoint binding and first-stream hello/welcome admission
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- room admission for clients and gateways
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- one gateway per room, duplicate client MAC rejection, and room limits
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- stable effective room MTU chosen before Ethernet datagrams flow
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- live Ethernet datagram forwarding with no ingress reflection
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- L2 safety filters for jumbo, switch-control, DHCP-server, and IPv6-RA frames
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- peer leave cleanup for room membership and MAC indexes
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## Build
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```bash
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cargo check --workspace
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```
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## Relay
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```bash
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cargo run -p lanparty-relay -- --listen 443/udp --dev-cert-der-out relay-cert.der
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```
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`--listen` accepts either a socket address or a UDP port shorthand such as
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`443/udp`. The relay binds a QUIC endpoint, accepts a control-stream `hello`,
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replies with `welcome` or `reject`, and forwards live Ethernet QUIC datagrams
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between accepted peers in the same room. It currently uses a generated
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self-signed development certificate; `--dev-cert-der-out` writes that
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certificate so the gateway and client can pin it in development. Production
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certificate handling remains future work. Ethernet forwarding decisions are
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logged with room, peer, MAC, ethertype, action, drop reason, and target count.
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## Gateway
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```bash
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cargo run -p lanparty-gateway -- \
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--relay 203.0.113.10:443 \
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--server-name lanparty-relay.local \
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--relay-ca-cert relay-cert.der \
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--room ROOM1 \
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--interface eth0
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```
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The gateway connects to the relay as `role = gateway`, completes the
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control-stream hello/welcome handshake, opens an AF_PACKET socket on the LAN
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interface, and bridges Ethernet frames between the relay and wired LAN until
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shutdown. It tracks remote-client source MACs seen from relay traffic and
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periodically emits small CAM refresh frames so the physical switch keeps those
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MACs associated with the gateway port.
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## Windows Client
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```bash
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cargo run -p lanparty-client-win -- \
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--relay 203.0.113.10:443 \
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--server-name lanparty-relay.local \
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--relay-ca-cert relay-cert.der \
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--room ROOM1
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```
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The Windows client binary currently connects to the relay as `role = client`
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with a generated locally administered virtual MAC persisted in
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`lanparty-client-identity.json`, completes the control-stream hello/welcome
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handshake, pins a host route for the relay IP on the current pre-TAP interface,
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verifies that the relay route still uses that pinned host route after TAP
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activation, and then bridges Ethernet frames between the relay and the first
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TAP-Windows6 adapter until shutdown.
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`--virtual-mac` can still override the stored identity for manual testing. On
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Windows it marks the TAP media connected and reports the driver MAC/MTU before
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forwarding frames, along with the TAP interface index/LUID. The client applies
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a scoped TAP interface metric and disables TAP default routes while it runs,
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periodically rechecks that the relay route remains pinned, then restores the
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previous route policy on exit. Until automatic TAP MAC/MTU configuration is
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wired, startup fails before bridging if the driver-reported MAC or MTU does not
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match the tunnel settings.
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