Files
mxaccess/design
Joseph Doherty 432f1102b7 [M2/M3] mxaccess-rpc: tokio DCE/RPC TCP transport (DceRpcTcpClient port)
Lands the async DCE/RPC TCP client — the transport that bridges the M2
PDU codec to a real socket. Unblocks M3 stream B (mxaccess-nmx, the
NmxClient) and brings F9 (ResolveOxid wrappers) within reach.

New
- transport.rs (~700 LoC, 10 tests including 2 real-socket tokio tests)
  — port of src/MxNativeClient/DceRpcTcpClient.cs.
  - DceRpcTcpClient::connect/bind/bind_with_managed_ntlm_packet_integrity/
    call/call_bound/call_bound_object — async over tokio::net::TcpStream.
  - encode_packet_integrity_request: 4-byte 0xBB pad + 8-byte AuthTrailer
    + 16-byte NtlmClientContext::sign signature, frag_length and
    auth_length rewritten in the embedded header per cs:201-250.
  - encode_request_bytes: PFC_OBJECT_UUID flag (0x80) and inserted
    16-byte object UUID slot per cs:269-278.
  - TransportError enum unifies io / codec / NTLM / fault / not-connected
    surfaces. Mirrors DceRpcFaultException as the typed Fault variant.
  - NTLM_AUTH_CONTEXT_ID = 79232 = 0x13580 (cs:90,133) exposed publicly.

Deliberately skipped: BindWithNtlmConnect / BindWithNtlmPacketIntegrity
(SSPI flavours at cs:55-63,108-149) — those wrap .NET's
System.Net.Security.SspiClientContext, which has no portable analogue.
Managed-NTLM path covers what the production Rust client needs.

mxaccess-rpc/Cargo.toml: added tokio (workspace-pinned).

design/followups.md: F9 downgraded P1 → P2 (transport landed; only the
two pure-codec ResolveOxid wrappers remain).

Test count delta: 354 -> 364 (+10).
Open followups touched: F9 partially advanced.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-05 07:47:42 -04:00
..

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 M2M6 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 .cs file path in src/MxNativeCodec/, src/MxNativeClient/, or src/MxAsbClient/, or
  • a docs/*.md spec file, or
  • a captures/0NN-frida-* directory or analysis/frida/*.tsv row.

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.md for the per-phase parallelism map.
  • Driving M2M6 autonomously via /loop: prompt.md (and the followups.md triage log it maintains).