Files
secs-gem/interop/README.md
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raphael fc3422a4a9 docs: move root .md files into docs/ + update every reference
Picks up the file renames that landed alongside the previous commit
and fixes everything that pointed at the old root locations:

- README.md doc-map updated: every entry now points at docs/X.md,
  with a new "docs/" lead entry pointing at the guided-tour index.
- README inline cross-refs (ARCHITECTURE / INTEGRATION / SECURITY /
  BENCHMARKS / MES_INTEROP / PROOFS) repointed to docs/.
- README "Interop" section rewritten — used to mention only
  secsgem-py; now covers all four external validators (secsgem-py
  31 / secs4java8 55 / tshark 69 frames / libFuzzer 200 k+ runs)
  with a one-line summary each, plus pointers to interop/README.md
  and docs/VERIFICATION.md.
- README "Deferred follow-ups" cleaned: dropped the explanatory
  "Listed here so reviewers don't go looking for them in
  COMPLIANCE.md and find an 'out of scope' entry that sounds
  defensive" sentence — the section header speaks for itself.
- docs/00_index.md "Where the rest of the docs live" table: dropped
  every `../` prefix since the docs are now siblings.
- docs/01_what_is_secs_gem.md PROOFS reference updated to sibling.
- docs/02_the_cast.md INTEGRATION + MES_INTEROP refs updated to
  siblings; dropped the stale "at the repo root" wording.
- interop/README.md: VERIFICATION + PROOFS refs updated to
  ../docs/X.md; stale "~24 + 4 checks" updated to 31 (matches
  PROOFS.md and README).
- examples/pvd_tool/README.md: every doc cross-ref now points at
  ../../docs/X.md.
- Source / data / CI comments mentioning doc names (e.g.
  "INTEGRATION.md §3", "COMPLIANCE.md gap") rewritten to
  "docs/INTEGRATION.md §3" etc. — affects 9 files across
  include/, apps/, tests/, data/, examples/, .gitea/workflows/.

Verified: full build under docker passes, 445/445 test cases pass,
2 753/2 753 assertions pass.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-06-09 19:36:27 +02:00

135 lines
6.1 KiB
Markdown

# External cross-validation harnesses
Every harness in this directory exists so a reviewer doesn't have to
take our word for it. Each one validates our C++ codec / framing /
dispatch against an **independent third-party implementation** that
read the SEMI standards without talking to us.
See [`../docs/VERIFICATION.md`](../docs/VERIFICATION.md) for the full
test plan and the honest accounting of which proofs are external vs
internal.
## What's here
| Validator | Independence | Coverage |
|--------------------------------------------|---------------------------------------------|---------------------------------------------------------------------------------------------------------------------|
| `host_vs_cpp_server.py` + `passive_equipment.py` | secsgem-py 0.3.0 — Python reference impl | 31 checks: S1, S2, S5, S6, S7, S10 happy paths + unsolicited S6F11 / S5F1 |
| `raw_gem300_harness.py` | secsgem-py with hand-crafted SecsStreamFunctions | 3 checks: S3F17, S16F5, S16F27 (limited by SFDL grammar) |
| `secs4j/Secs4jHostHarness.java` | secs4java8 — Apache 2.0 Java impl by kenta-shimizu | **55 checks** across S1/S2/S3/S5/S6/S7/S10/S14/S16, including the full E40 body that defeated secsgem-py and unsolicited S6F11/S5F1 observation |
| `tshark_validate.sh` | Wireshark's built-in HSMS dissector | 69 captured frames dissected with no malformed-packet warnings |
| `spool_persistence_test.py` | secsgem-py + a docker-restart loop | Restart-survives-spool integrity |
| ⚙️ `../tests/test_e5_kat.cpp` | SEMI E5 §9 encoding rules | 196 known-answer byte assertions across every format code |
| ⚙️ `../apps/fuzz_secs2_decode.cpp` + `fuzz_sml_parse.cpp` | libFuzzer + ASan + UBSan | ~70 000 + ~285 000 random inputs per minute, 0 crashes |
The ⚙️ entries aren't in `interop/` directly because they don't
involve a network peer — they're either pure codec round-trips
(KAT) or coverage-guided fuzzing. Listed here so the full external
proof inventory lives in one place.
## Running each validator
### secsgem-py — secsgem-py active host → C++ server
```sh
docker compose up -d server
docker compose run --rm interop python3 /app/interop/host_vs_cpp_server.py \
--host server --port 5000 --session-id 0
```
### secsgem-py — C++ host → secsgem-py equipment
```sh
docker compose up -d equipment_py
docker compose run --rm builder /app/build/secs_interop_probe \
--host equipment_py --port 5000 --device 0
```
### secsgem-py — raw GEM 300 frames
```sh
docker compose up -d server
docker compose run --rm interop python3 /app/interop/raw_gem300_harness.py \
--host server --port 5000 --session-id 0
```
### secs4j — independent Java host → C++ server
```sh
bash interop/secs4j_validate.sh
```
Builds an `eclipse-temurin:21-jdk` sidecar with secs4java8 cloned +
compiled at image build, then drives 55 checks against
`compose up server`. See `secs4j/Secs4jHostHarness.java` for the
list and `secs4j/Dockerfile` for the build.
### tshark — Wireshark HSMS dissector
```sh
docker compose run --rm builder bash /app/interop/tshark_validate.sh
```
Captures a pcap of the demo flow, runs `tshark -V` with the HSMS
dissector forced for the test port, asserts no malformed packets +
that all expected control/data frames parse.
### spool persistence — restart-survives test
```sh
bash interop/spool_persistence_test.py
```
Drops the host link mid-flight, kills the server, restarts it, and
asserts the spooled S5F1 / S6F11 frames drain to the host on
reconnect.
## What these harnesses caught
Real bugs surfaced during interop development (now fixed):
1. **Strict U-width parsing rejected U1-encoded identifiers.** SEMI
E5 declares DATAID, RPTID, VID, CEID, ALID, EXID etc. as
`U1 | U2 | U4 | U8`; secsgem-py picks the smallest width that
fits. Our scalar accessors were strict. Now lenient with
range-checked downcasts (`messages_helpers.hpp::any_unsigned_first`).
2. **PPBODY rejected when sent as ASCII.** SEMI allows PPBODY to be
`ASCII | Binary | List`; secsgem-py defaults to ASCII. Added the
`BINARY_OR_ASCII` codegen type and the `as_text_or_binary`
accessor.
3. **Missing S1F23 / S1F24 (Collection Event Namelist).** Added the
wire schema, the `vids_for(ceid)` accessor, and the dispatch
handler.
4. **Missing S10F3 handler (host→equipment Terminal Display).** Our
server only registered S10F1; per SEMI E5 §13 those are opposite
directions. Added the missing dispatch.
5. **TSan use-after-free in `act_exception_complete`** (test code,
not library): held a pointer across `fire_internal(RecoveryComplete)`
which deletes the entry. Found by the ThreadSanitizer lane on
first run.
The C++ test suite stayed green through every one of these fixes —
the changes were purely permissive widenings or additive features,
no existing behaviour broke.
## When to add a new validator
A new third-party SECS implementation, or a new dissector, or a new
fuzzer target — anything that exercises our wire surface from an
angle the existing five don't cover — is worth adding. The pattern
is consistent:
1. New script / harness lives here (or a sidecar Docker context for
non-Python validators).
2. Wired into `.gitea/workflows/ci.yml` as a separate job.
3. Listed in this README's table + in `../VERIFICATION.md`.
4. Surfaced in [`../docs/PROOFS.md`](../docs/PROOFS.md) if it adds a
meaningful new dimension.
Bug reports from a new validator → file at
`raphael@maenle.net` with the wire trace, the validator's output,
and the equipment YAML so we can reproduce.