The MVP bridge treats each remote player as a normal host on the LAN, not as a
trunk port. Allowing client-origin VLAN-tagged frames would let a remote client
send traffic outside the simple untagged Ethernet model, and could also hide
IPv4/IPv6 control traffic behind an outer VLAN EtherType that the existing
safety filters do not parse.
Filter 802.1Q, 802.1ad, and common QinQ-tagged frames from remote clients before
they can reach the physical LAN. LAN-origin tagged frames are still allowed back
toward clients so the gateway remains a transparent receiver for whatever the
local wired network emits. Add a dedicated drop reason so relay logs make the
policy clear.
Test Plan:
- cargo fmt --check
- cargo test -p lanparty-relay -p lanparty-obs
- cargo test --workspace
- cargo clippy --workspace --all-targets -- -D warnings
- git diff --check
Refs: MVP relay L2 safety filters
ddidderr
0784e73f30
