SVC_ROUTE_HDR: +uint8_t flags (23 bytes total).
bit7=START (0x80) — first data packet of new session
bit6=RST (0x40) — sequence violation detected
bit5-4=sess_id (0-3) — cyclically incremented on restart
router_send_one_flags: sets START+sess_id on first data packet.
router_send_ack: sets sess_id only (no START for ACK).
etcp_router_recv_cb: detects restart via sess_id change or START flag.
Old seq=0 heuristic replaced with explicit flags.
etcp_router_conn_get: init sess_id=0, peer_sess_id=0, start_sent=0.
etcp_router_conn_restart: increment sess_id before closing rconn.
etcp_router: new etcp_router_conn_restart(inst, node_id, svc_id) — closes
all rconns for the peer, notifies service via cb(NULL, entry) with
node_id, resets seq state.
seq=0 detection in etcp_router_recv_cb: when rx_seq >= 256 (MAX_INFLIGHT)
and a data packet arrives with seq=0, detect peer restart and reset rconn.
tcp_proxy_client: handle TCP_PROXY_SUBCMD_RESTART — clear all client conns
and server conns for the restarted peer.
Threshold prevents false positives on in-window seq=0 duplicates.
- consumer_ack flag: ACK sent only on consumption, not assembly
- etcp_router_consumer_ack() — called from tcp_proxy_client feed_from_transport
- last_ack_sent_tb: interval-based throttle — send immediately if >=10ms passed,
otherwise timer for remaining time
- timer rules: NULL handle after cancel/fire, NULL check before start
- ROUTER_ACK_INTERVAL_TB 1000→100 (100ms→10ms)
- test_etcp_router_unit: updated test 14 for new immediate-send behavior
rx_acked was used for two conflicting purposes:
1. remote ack of our sends (inflight = tx_seq - rx_acked)
2. our last sent ACK seq (dedup: rx_seq != rx_acked)
When the ack timer fired and set rx_acked = rx_seq, it overwrote
the inflight-tracking value. If rx_seq > tx_seq, the computation
tx_seq - rx_acked underflowed (e.g. 18 - 24 = 0xFFFFFFFA),
permanently blocking router_drain_send_q and causing send_q to
grow indefinitely.
Fix:
- Split rx_acked into tx_acked (remote ack, for inflight) and
last_sent_ack_seq (our ACK, for dedup)
- Incoming ACK handler only advances tx_acked forward (stale guard)
- Use int32_t cast on all inflight comparisons to handle stale states
- Add etcp_router architecture diagram (doc/etcp_router_arch.md)
- ROUTER_SEQ_CLOSE_FLAG (0x80000000): normal conn close
- ROUTER_SEQ_RST_FLAG (0x40000000): conn not found
- router_send_to(): SVC_ROUTE with flags, no conn needed
- router_send_close_to_service(): notify local service [svc_id],len=1
- router_close_and_notify(): CLOSE to remote + close to local + cleanup
- etcp_router_conn_close(): sends CLOSE to remote before cleanup
- etcp_router_conn_close_all_for_node(): close all conns for dead peer
- recv_cb: flags checked only when pl_len==0 (avoid seq collision)
- etcp_router_destroy: close notification to each service
- New SVC_ROUTE_HDR (packed struct, 22 bytes): cmd+dst+src+seq+svc_id
- ETCP_ROUTER_CONN: state per (remote_node_id, svc_id), hash-indexed in router_conns
- Reorder via recv_q (hash by seq), dedup with 32-bit circular compare
- Periodic ACK (100ms), idle ACK (500ms), inflight limit via tx_seq - rx_acked
- Legacy mode: no conn → direct delivery without reorder
- etcp_router_conn_get/send/close API for seq-managed connections
- Unit test test_etcp_router_unit: 18 tests, 3ms, no ETCP/sockets/BGP
etcp_router: routable service packets with dst/src node_id
- etcp_router_bind/unbind: per-instance service handler registry
- etcp_route_send: send to node by id via BGP routing
- multi-hop forwarding through intermediate nodes
- loopback optimization (dst==self dispatches directly)
remote_proxy: exit node creating OS sockets on demand
- handles CONNECT/DATA/CLOSE via etcp_router
- non-blocking socket connect with uasync callbacks
- echo back response data to requesting node
tcp_proxy: etcp_transport for remote proxy
- via_node_id in mapping selects between sock/etcp transport
- unified handler for both tcp_proxy and remote_proxy roles
- config: forward = port -> ip:port via NODE_HEX [remote_proxy] section
tests: test_etcp_router (20 pkts bidirectional), test_remote_proxy (echo)
Evgeny