ddidderr
25157ad1a6
The LAN switch has to keep learning that remote client MAC addresses live on the gateway port. Once the gateway injects a remote client's traffic, that learning can age out if the client is quiet, breaking the Layer 2 illusion. Track valid remote-client source MACs observed in relay traffic and inject a small padded CAM refresh frame for each known MAC every 60 seconds. The refresh frame uses the remote MAC as the Ethernet source and the gateway NIC MAC as the destination, with a local experimental EtherType so hosts should ignore it. PacketSocket now reads the wired interface hardware address with SIOCGIFHWADDR when opening the AF_PACKET socket. Non-Ethernet or invalid source interfaces fail early instead of starting a gateway that cannot emit refresh traffic. Test Plan: - cargo fmt --check - cargo test --workspace - cargo clippy --workspace --all-targets -- -D warnings - git diff --check Refs: PLAN.md Linux gateway CAM-table refresh
115 lines
3.9 KiB
Markdown
115 lines
3.9 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-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-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.
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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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--virtual-mac 02:00:00:00:00:51
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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 the configured virtual MAC, completes the control-stream hello/welcome
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handshake, and then waits for shutdown. TAP adapter binding and route pinning
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are not wired yet.
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