The pod can now run entirely over the relay: one outbound TCP connection
carries both the console protocol (egg/launch) and all game traffic
(envelope-multiplexed), so internet play works behind NAT with no port
forwarding. All new code is behind 'if (relayMode)' (BT_RELAY unset => mesh
mode byte-for-byte untouched; verified un-regressed).
Env gates (parsed once in the ctor, after WSAStartup so gethostbyname works):
- BT_RELAY=<host>:<consolePort> (host may be a DNS name; game port = +1)
- BT_SELF=<exact [pilots] entry> (NIC matching can't identify us across NAT)
L4NET changes:
- CreateConsoleHost: relay branch dials OUT to the relay console port
(bounded retry; console-less continue on a re-dial) instead of listening.
- StartConnecting: relay self-match by BT_SELF string; peers become VIRTUAL
hosts (INVALID_SOCKET, NoNetworkConnectionStatus) flipped online by the
relay's PEER_UP; then ConnectRelayGame dials the game port + HELLOs. HostID
assignment / remoteHostCount / the connection gate / app ladder unchanged.
- CheckRelay (new): the receive seam -- drains {route,length} envelopes,
synthesizes HostConnected/Disconnected from PEER_UP/DOWN (same messages the
mesh accept path routes), returns game frames envelope-stripped (they
self-identify via NetworkPacketHeader.fromHost; consumers route by payload).
- Send: game-host traffic -> relay unicast envelope (console host excluded --
its legacy protocol is relay-TERMINATED, not routed).
- ExclusiveBroadcast: build ONCE, send ONCE with the broadcast route -- the
relay fans out, killing the mesh's (N-1)x upload duplication.
- RelaySendAll (new): partial-send-safe transmit (required on the multiplexed
socket -- a partial write would desync framing for all peers).
- CheckBuffers: polls CheckRelay first; skips recv on virtual game hosts.
- RelayGameDown: relay-loss synthesizes all-peers-disconnected (match
continues peer-less; pod never exits mid-match).
- Mode(): now STORES the reliable/unreliable mode (was ignored) for the UDP
phase's authentic mode+flag routing.
Verified 2-node localhost relay (MP_RELAY.EGG, tagged [pilots]):
- both pods reach 'All connections completed!' via PEER_UP, then
RunningMission; both mechs' MakeMessages cross the relay (paint x2 each) and
bidirectional 148-byte update records flow (net-tx/net-rx traces; relay
stats tcp rx==tx, registered [2,3]); cockpit/HUD render; no crashes.
- driving one node transmits pose/damage/death frames through the relay.
- mesh smoke (no BT_RELAY): 2-node session still forms + simulates unchanged.
Plan: ~/.claude/plans/partitioned-snuggling-piglet.md. Next: UDP channel.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>