Captured OBJREF byte structures from both paths via the .NET probe:
- `--probe-callback-marshal`: DCOM-marshalled, 338 bytes, succeeds
(when used inside `MxNativeSession.Open` → `CreateRegisteredService`).
- `--probe-register-managed-callback`: hand-rolled, 162 bytes, fails
with `RegisterEngine2 → 0x800706BA RPC_S_SERVER_UNAVAILABLE`.
The structural diff:
- `std_flags`: DCOM=`0x0A80` (SORF_OXRES4+6+8) vs hand-rolled=`0x280`
(SORF_OXRES4+6). Bit `0x0800` (SORF_OXRES8) only set in DCOM.
- ncacn_ip_tcp bindings: DCOM=4 with no ports; hand-rolled=1 with
explicit `[port]`.
- Total size: 338 vs 162 bytes.
Tested the simplest fix (hand-rolled `std_flags = 0x0A80` to match
DCOM): **still fails with the same 1722.** Reverted.
**Diagnosis updated in F55:** NmxSvc on receiving RegisterEngine2
appears to call `IObjectExporter::ResolveOxid` against the local
SCM (`127.0.0.1:135`) to resolve the callback OBJREF's OXID, then
dial the resulting bindings. Our hand-rolled OXID is never
registered with RPCSS, so the SCM-side resolution fails and NmxSvc
returns RPC_S_SERVER_UNAVAILABLE — matching:
- the symptom (1722),
- the sub-second timing (no TCP dial-back to our listener attempted),
- the fact that the .NET `ManagedCallbackExporter` (same hand-rolled
approach) ALSO fails identically.
DCOM marshalling fixes this because `CoMarshalInterface` internally
registers the OXID with RPCSS. The bindings have no port because
RPCSS returns the dynamic port from the DCOM stub layer.
**Conclusion: Path A is the architecturally correct fix** — the
callback exporter must be a DCOM-managed object (e.g. via
`windows-rs` `#[implement]`) for NmxSvc to accept the callback.
The hand-rolled-listener-with-explicit-port approach is
fundamentally incompatible with NmxSvc's callback validation, in
both Rust and the .NET reference.
Path C (cheap investigation) is exhausted; F55 verdict updated to
recommend Path A explicitly.
`cargo test --workspace` 824 passing; clippy `-D warnings` clean
across both feature configurations.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Fix all 33 rustdoc warnings across the workspace:
- Unresolved intra-doc links: rewrite [`name`] → either backtick text
(when not actually a link) or fully-qualified `[Type::method]` /
`[crate::module::name]` form. Affected: mxaccess-codec
(asb_variant, item_control, metadata_query, observed_write_template,
reference_handle, write_message), mxaccess-rpc (pdu), mxaccess-nmx
(client), mxaccess-asb-nettcp (nmf), mxaccess-callback (exporter),
mxaccess (asb_session, session, lib).
- Bracket-text being interpreted as link refs (e.g. `body[17]` →
`` `body[17]` ``).
- Private-item references in public docs (CALLBACK_BROADCAST_CAPACITY,
recover_connection_core, mxvalue_to_writevalue) reduced to
backtick-text since they aren't part of the public API.
`RUSTDOCFLAGS="-D warnings" cargo doc --workspace --no-deps` now
exits clean. Workspace 759 tests pass; clippy clean.
Defers `#![warn(missing_docs)]` lint to a future pass — the cleanup
target is the broken-link warnings, which are signal; missing-docs
would surface hundreds of low-priority public-item gaps that are out
of scope for this F-number.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty