Wire `.connect_to()` (dial by service name), `.connected()`
and `.get_stream_addrs()` on top of `MsgpackTransport` so
`trio.SocketStream` + the existing `<I`-prefix framing carry
`msgpack` msgs over TIPC unchanged.
XXX both ends of a connected TIPC sock answer `TIPC_ADDR_ID`
port-ids and a port-id carries NO service name, so,
- the *dialling* side re-asserts the name it actually dialled
over `._raddr` (same move as `MsgpackUDSStream`s peer-pid
re-assign),
- the *accepting* side keeps a `TIPC_NAME_UNKNOWN` sentinel
plus the observed `(node, ref)`. It doesn't need more — the
`Aid` from `._do_handshake()` already carries the peer's
logical identity.
Also normalize dial failures: TIPC answers an unpublished-name
lookup with `EHOSTUNREACH`, which python maps to a **bare**
`OSError` and NOT a `ConnectionError` subtype the way
`ECONNREFUSED` maps to `ConnectionRefusedError`. The
discovery-ping path needs the `ConnectionError` shape, so the
`_reraise_as_connerr()` wrap is load-bearing, not polish.
XXX ALSO tolerate a dead peer in `.get_stream_addrs()`!
Unlike tcp/uds — where the kernel keeps answering the peer
addr until *we* close — TIPC answers `ENOTCONN` once the peer
is gone. Since `MsgpackTransport.__init__()` calls
`.get_stream_addrs()` (via `Channel.from_stream()`) BEFORE the
handshake, an unguarded `OSError` there escapes
`handle_stream_from_peer()`s handshake tolerance (contract §4)
and tears down the WHOLE actor. Any connect-then-drop peer — a
port scan, a liveness probe, a cancelled dial — was a remote
actor-kill. A dead peer must cost us an addr, not the runtime.
Deats,
- `TIPC_IMPORTANCE` exposed as a `.connect_to()` kwarg — TIPC
can rank a conn's traffic under congestion, which no other
backend can do. Defaulted to the kernel default for now;
wiring the parent<->child chan to `HIGH` is a follow-up.
- `TIPC_DEST_DROPPABLE = 0` so undeliverable msgs surface as
errors instead of being silently dropped.
(this patch was generated in some part by `claude-code` using `claude-opus-5` (`anthropic`))