Joseph Doherty
c73a33edd8
Path A landed for R3/R4. The byte->MxStatus synthesizer in Lmx.dll is
FUN_10100ce0 (`analysis/ghidra/exports/Lmx.dll.synthesizer-helpers2-decompile.md`),
a 4-byte u32 LE -> 4-tuple MxStatus decoder used by every NMX-frame
parser in Lmx.dll. The kernel is byte-deterministic and context-free,
so it ports as a pure function -- the operation-tracking state
machine the original verdict deferred is NOT required for synthesis.
Bit layout (per FUN_10100ce0 lines 21-24):
bit 31: success (-1 if set, 0 if clear)
bits 27..24: category (4 bits)
bits 23..20: detected_by (4 bits)
bits 15..0: detail (i16 -- low 16 bits, signed)
bits 30..28, 19..16: reserved/padding
Codec changes:
- MxStatus::from_packed_u32() / ::to_packed_u32() -- the kernel +
inverse for round-trip parity.
- MxStatus::from_nmx_response_code() -- the constructed-from-response-
code switch in FUN_1010bd10:741-770 (six proven mappings: 0x01, 0x02
-> CommunicationError + RequestingNmx; 0x03 -> ConfigurationError +
RequestingNmx; 0x04 -> ConfigurationError + RespondingNmx; 0x05 ->
CommunicationError + RespondingNmx; 0x1A -> CommunicationError +
RequestingNmx).
- MxStatusCategory / MxStatusSource: from_i16/to_i16 promoted to const
fn so MxStatus::from_packed_u32 can be const.
- NmxOperationStatusMessage::try_parse_process_data_received_body() --
thin wrapper that peels the outer NmxObservedEnvelope before
delegating to try_parse_inner. Mirrors
NmxOperationStatusMessage.TryParseProcessDataReceivedBody (.NET cs:20-32).
- NmxOperationStatusMessage::promote_to_typed() -- entry point that
returns the existing Status field. Documented as a no-op pass-through
for now (the 5-byte inner-body wire shape is NOT the same field as
the 4-byte packed-u32 the kernel decodes); kept for API symmetry.
- 22 new round-trip tests covering the kernel, the response-code
switch, the proven 0x00/0x41/0xEF completion bytes, and round-trip
for every canonical sentinel.
mxaccess (Session) changes:
- New OperationKind enum (Write/WriteSecured/Read/Subscribe/
Unsubscribe/Activate/Suspend/Other).
- New OperationContext struct (correlation_id, op_kind, reference,
retry_count) -- ground for the F54 follow-on per-operation
correlation work.
- New OperationStatus event type {raw, status, context,
is_during_recovery}, mirroring MxNativeOperationStatusEvent (cs:73-78)
with the typed-MxStatus addition.
- Session::operation_status_events() -> broadcast::Receiver<Arc<
OperationStatus>> + operation_status_stream() Stream variant.
- callback_router() now tries operation-status parsing first, falling
through to subscription messages -- matches MxNativeSession
.OnCallbackReceived dispatch order (cs:574,582,590).
- recover_connection() flips a recovery_active counter (Arc<AtomicU32>
shared with the router) so OperationStatus.is_during_recovery is
populated correctly. Mirrors MxNativeSession._recoveryActive
Volatile.Read at cs:573.
- 3 new router tests covering: status-word frame dispatch + typed
promotion to WriteCompleteOk; completion-only frames stay verbatim;
is_during_recovery is stamped from the live counter.
Per-operation context tracking (correlating completion frames back to
outstanding writes/subscribes via the correlation_id) is filed as F54
in design/followups.md. The synthesizer kernel itself is byte-
deterministic, so the kernel and the correlation work are decoupled.
Ghidra evidence (the next-ring xref walk beyond FUN_10114a90):
- analysis/ghidra/exports/Lmx.dll.set-attribute-result-xrefs.md --
xrefs to OnSetAttributeResult / CancelWithStatus / OperationComplete.
- analysis/ghidra/exports/Lmx.dll.vtable-data-xrefs.md -- vtable-slot
data xrefs for the virtual-dispatch path.
- analysis/ghidra/exports/Lmx.dll.synthesizer-decompile.md --
ScanOnDemandCallback::OperationComplete/MultipleOperationComplete
(FUN_1010b990), RemotePlatformResolver::OperationComplete
(FUN_1010dc80), and the constructed-from-responseCode synthesizer
in FUN_1010bd10 (lines 698-770). FUN_1010bd10 is the wire-frame
receiver that drives the synthesis.
- analysis/ghidra/exports/Lmx.dll.synthesizer-helpers-decompile.md --
FUN_10003fc0 (the <success %d category %d ...> formatter; confirms
the 4-tuple layout), FUN_1008f150 (dispatch helper).
- analysis/ghidra/exports/Lmx.dll.synthesizer-helpers2-decompile.md --
FUN_10100ce0 (the kernel itself), FUN_10100bc0 (3xu16 reader),
FUN_1005e580 (4-byte stream reader), FUN_1010ee00 (sister NMX-frame
parser using the same kernel).
- analysis/ghidra/exports/Lmx.dll.synthesizer-callers-xrefs.md --
caller graph; confirms the kernel is called from many wire-frame
parsers but each parser shares the single 4-byte decoder.
R3/R4 verdict updated in design/70-risks-and-open-questions.md from
"settled at verbatim-preserve" to "settled per Path A". F54 filed in
design/followups.md for the per-operation correlation work.
cargo build / test / clippy -D warnings / RUSTDOCFLAGS=-D warnings doc
all clean. cargo public-api baselines regenerated for mxaccess and
mxaccess-codec.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
design/ — Rust port architectural plan
This folder is the design contract for the Rust replacement of AVEVA/Wonderware MXAccess. It is the gap between the .NET reference in src/ and the Rust crates that will be written under a sibling rust/ workspace (per CLAUDE.md).
The folder is structured as a small set of focused documents. Read in order; each builds on the previous.
| File | Purpose |
|---|---|
00-overview.md |
Mission, two-layer goal, architectural principles, non-goals |
10-raw-layer.md |
Byte-accurate raw MXAccess layer (codec + transport + session) |
20-async-layer.md |
Idiomatic Tokio async layer on top of the raw layer |
30-crate-topology.md |
Cargo workspace, crates, dependencies, build/test commands |
40-protocol-invariants.md |
Bill of materials: IIDs, opnums, envelope/handle bytes |
50-error-model.md |
MxStatus, error types, panic/cancellation policy |
60-roadmap.md |
Milestones M0..M6, validation strategy |
70-risks-and-open-questions.md |
Parity gaps, unproven flows, cross-platform constraints |
dependencies.md |
Cross- and within-milestone parallelism map; agent budget per phase |
review.md |
Adversarial review log (BLOCKER/MAJOR/MINOR/NIT findings, all resolved) |
prompt.md |
/loop driver prompt for autonomous M2–M6 execution |
followups.md |
Open / resolved deferred work items; auto-triaged by prompt.md Step 0 (created on first /loop run if missing) |
The design is grounded in the .NET reference at src/ and the protocol artifacts in docs/, analysis/, and captures/. Do not introduce protocol behavior in these documents that is not already proven in the reference. When adding a new claim about wire format, cite either:
- a
.csfile path insrc/MxNativeCodec/,src/MxNativeClient/, orsrc/MxAsbClient/, or - a
docs/*.mdspec file, or - a
captures/0NN-frida-*directory oranalysis/frida/*.tsvrow.
This folder is documentation, not code. When the Rust workspace is created, the design here is the contract it must satisfy. When evidence in captures/ invalidates a design decision here, update the design first, then the code.
Reading order
- New contributor: 00 → 30 → 10 → 40 → 20 → 50 → 60 → 70.
- Protocol question: 40 first, then the relevant section of 10.
- API question: 20 first, then 50.
- Planning a milestone: 60 first, cross-reference 70 for blockers.
- Scheduling concurrent work:
dependencies.mdfor the per-phase parallelism map. - Driving M2–M6 autonomously via
/loop:prompt.md(and thefollowups.mdtriage log it maintains).