Previous edit accidentally removed tcp_conn_destroy, timer cancellations,
and etcp_router_cancel_send_ready from conn_free. Without tcp_conn_destroy
the socket was never removed from uasync, causing repeated EPOLLERR →
repeated conn_free on freed memory → double-free crash.
Added debug logs for freed guard entry and u_free.
error_cb can fire twice for the same fd in one epoll batch,
or conn_free called from multiple callbacks during restart/shutdown.
freed flag makes conn_free idempotent.
tcp_conn_destroy: set read/write queue callbacks to NULL before
queue_free to stop deferred autofetch (drain_cb on freed rc).
write_on_get_cb: throttle consumer_ack to every 8th write_queue
dequeue instead of every single one (was 30+ ACK/sec).
ack_batch field in tcp_proxy_server_conn.
handle_connect: send first consumer_ack after setting consumer_ack=1
to unblock client router — fixes rq=32/send_q=256 deadlock.
diag_timer_cb: added send_q=N to DIAG line for instant root cause visibility.
read_queue_drain_cb: SOCK:BACKPRESSURE log with send_q count.
write_on_get_cb: SOCK:ACK debug log on each consumer_ack.
1-sec diag_timer_cb prints rq/wq counts+bytes, outstanding pool
allocations, tcp kernel buffer sizes (SO_RCVBUF/SO_SNDBUF).
Started in handle_connect, cancelled in conn_free.
External code pushes to write_queue directly (entry_pool + data_pool).
Added queue_set_threshold(write_queue, 32, 0) for write backpressure.
Tests split data into write_chunk_size chunks before queue put.
lib/u_async: uasync_set_socket_read/write — O(1) EPOLL_CTL_MOD toggle per socket
lib/ll_queue: queue_set_empty_callback — one-shot deferred callback on queue drain
lib/tcp_io: TCP connection management via uasync + ll_queue with pool alloc
- read: direct recv into pool buffer, high/low water flow control
- write: autofetch via ll_queue callback, partial send via write_buf
- on_fin/on_error/on_flushed callbacks, FIN deferred until read_queue drained
- getpeername for pre-connected socket detection
tcp_proxy_server: migrated to tcp_io (22→13 fields, 437→270 lines, -7 functions)
tests: test_tcp_io (5 tests), test_tcp_proxy_server rewritten for tcp_conn
- tcp_proxy_client_handle_error: set error flag + send CLOSE once if flag was clear
- tcp_proxy_client_handle_data/handle_close: drop silently, don't send ERROR back
- tcp_proxy_server_handle_data/handle_close: drop silently, don't send ERROR back
- Add recv→send 1MB integration test (3 clients × 3 requests, shell + python)
- remove sock_transport, transport abstraction, active connections API
- simplify proxy_conn to 13 fields (was 15), remove tcp_proxy_mapping linked list
- new protocol: stream_id 4B, seq 2B cyclic, HDR_SIZE 8B
- add ERROR subcmd for immediate abort, CLOSE for graceful half-close
- proper half-close: shutdown SHUT_WR, keep reading, no timer
- exhaustive DEBUG_ERROR/WARN on all error/unusual branches
- config parser: report unknown options with filename:line and valid keys
- Add closing_sent flag to proxy_conn (CLOSE sent to exit, no need to wait for reply)
- proxy_poll_cb: send CLOSE when done || sndbuf==0; cleanup when tun && (rem||sent)
- Destroy transport in proxy_poll_cb cleanup (fix 56-byte leak)
- remote_proxy_handle_close: shutdown(SHUT_WR) + 2s timer instead of immediate rp_conn_free
- Remove SHUTDOWN subcommand entirely (not needed with new lifecycle)
- UDP proxy: datagram relay client↔exit over ETCP
- ICMP proxy: echo ping relay client↔exit over ETCP
- Move via_node_id from per-forward-mapping to global tcp_proxy setting
- Support multiple concurrent tcp_proxy instances (no singleton g_tcp_proxy)
- Cap handshake padding to stay within 1472+overhead
- Handle non-TCP packets (UDP/ICMP) in tcp_proxy raw/tun input paths
- Add utun_instance_create_from_str() for test config creation
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