Per contract §0 ("if this doc disagrees with the code, the code
wins; fix it in the same PR"), fold the step-0 probe results and
the as-landed impl back into `01_tipc_backend.md`.
Settled the two claims §9 flagged as unverified,
- `SO_ACCEPTCONN` on `AF_TIPC` **works** (answers `1`); we never
needed trio's `except OSError` carve-out.
- dup-name bind → **silent crosstalk is real**: both binds
succeed and dials alternate strictly, so a `.get_random()`
clash is never `EADDRINUSE`.
Corrections where the plan was wrong,
- §5.2's `tipc_event` is **48B not 40B** (`4+4+4+8+28`), and
python exposes `TIPC_WAIT_FOREVER` as `-1` so it needs masking
before packing as `'I'`.
- §7.2's pytest mark goes in `_testing/pytest.py::
pytest_configure()`, NOT `pyproject.toml` — the repo has no
`markers` ini table.
- §7.4's "10k → 10k distinct" is a ~1.2% flaky assert by
birthday bound on a 32b instance space; use `>= n-2` w/ the
arithmetic documented.
- §2.2's `unwrapped_type` and §3.2's `from_addr()` sketch still
showed the 2-tuple + the `'tipc:<stype>:<scope>'` prefix hack
that §2.2 itself had already withdrawn.
Two hazards the plan never anticipated, now recorded in §9,
- an unpublished-name dial answers `EHOSTUNREACH` which python
maps to a **bare `OSError`**, NOT a `ConnectionError` subtype,
so the `_reraise_as_connerr()` wrap is contract-§4 mandatory.
- a connect-then-drop peer answers `ENOTCONN` from
`getpeername()`, which — since `.get_stream_addrs()` runs
BEFORE the handshake — used to kill the whole actor.
Also withdraw §9's "fold a 6-byte digest into `(stype_low,
instance)`" escalation: varying `_stype` per-actor would need
65536 topology subscriptions and kills layer B outright.
(this patch was generated in some part by `claude-code` using `claude-opus-5` (`anthropic`))
Shape-matching in `wrap_address()` doesn't survive 4 backends and
the plans were papering over it: TIPC's natural unwrapped form is
a `(str, int)`, indistinguishable from `TCPAddress`, and iroh's
is a `(str, str)`, which the *existing* UDS case
(`case (_, filename) if type(filename) is str`) already swallows.
So the contract doc (§1.1) now carries the conclusion as a
**recommended prerequisite for all three backends**: make the
unwrapped form carry an explicit proto-key spelled with the
`multiaddr` protocol name — `('tcp', host, port)`,
`('unix', path)`, `('tipc', stype, inst, scope)`. `wrap_address()`
then collapses from an order-sensitive `match` to
`_address_types[addr[0]]` and the whole collision class stops
existing, while the on-wire form finally agrees w/
`mk_maddr()`/`parse_maddr()` instead of being an independent
invention.
Two consequences spelled out: it's a wire-format change
(`SpawnSpec`, `_root_mailbox`, `_registry_addrs`) + every fixture
+ downstream config, so it wants its own migration commit landed
*before* any new backend; and it's the moment to stop handing raw
tuples to users at all — `Address` becomes the public currency
and `UnwrappedAddress` an internal serialization detail, the same
discipline `ipaddress` uses (you pass `IPv4Address`, never a
4-tuple).
Plan 01 §2.2 is rewritten to match and to explicitly **retract**
its own earlier `('tipc:<stype>:<scope>', instance)` self-tagging
prefix hack — it keeps `wrap_address()` order-sensitive and does
nothing for the iroh/UDS collision, so the doc says don't
resurrect it. Registration checklist item 4 likewise becomes "do
the migration first, then this is a one-line `_address_types`
entry".
Also seeds a `/tipc` multiaddr-spec submission as a follow-up,
mirroring the `wg` track (multiformats/py-multiaddr#107/#108 + gh
(this patch was generated in some part by `claude-code` using `claude-opus-5` (`anthropic`))
Plan doc for gh #378, the cheapest new backend we can add: it's
stdlib-only (CPython ships `AF_TIPC` + 23 `TIPC_*` consts) and
per the contract doc `trio`'s stream/listener wrappers don't care
about the addr family, so `MsgpackTransport` framing and
`trio.serve_listeners()` are reused verbatim.
Deats,
- `TIPCAddress` as a *service name* `(type, instance)` w/ scope
as the `.bindspace`; `bind()` publishes the singleton
name-range, peers `connect()` by name and the kernel resolves
+ load-balances. I.e. registration/lookup for free, no
registrar in the loop.
- the self-tagging `('tipc:<stype>:<scope>', instance)` unwrapped
form + why it must be match-ordered before `TCPAddress`'s.
- `get_random()` via a blake2b digest of the actor id (there's no
`port=0` analogue) and the silent-crosstalk risk that follows:
TIPC *allows* dup binders and round-robins, so a collision
doesn't `EADDRINUSE`, it cross-talks.
- an `Address.rebind_from_sockname` ClassVar to opt out of
`Endpoint.start_listener()`'s `getsockname()` reconcile, which
for TIPC always returns a port-id, never the bound name.
- the `TIPC_TOP_SRV` topology-service subscription as an `@acm`
yielding a chan of typed name-table events — push-based
register/dereg, the real "end game cluster proto" bit.
- commit sequencing, hard capability gating (`modprobe tipc`;
bare `AF_TIPC` is `EAFNOSUPPORT` on a stock box), CI matrix
notes, risks + follow-up seeds.
(this patch was generated in some part by `claude-code` using `claude-opus-5` (`anthropic`))
Gud Boi