v1.0.8

Date: 2026-07-30
Previous release: v1.0.7

Summary

Patch release: bump go-mms to v1.0.7 (pulls go-cotp v1.0.4 / go-tpkt v1.0.1).
No public API surface or behavioural changes. Go floor remains 1.24.

Dependencies

• go-mms — v1.0.6 → v1.0.7
• go-cotp (indirect) — v1.0.3 → v1.0.4
• go-tpkt (indirect) — v1.0.0 → v1.0.1

Unchanged

• No API, wire, or behavioural changes. Import path remains github.com/otfabric/go-iec61850.

v1.0.7

Date: 2026-07-30
Previous release: v1.0.6

Summary

Dial now propagates DialOptions.Logger into the underlying MMS client when
MMS.Logger is unset (matching existing Server behaviour). Dependency bump to
go-mms v1.0.6 / go-cotp v1.0.3. Docs and Makefile tooling aligned with sibling
OT Fabric libraries, including a real make fuzz target. Broad unit-test
coverage lift (non-example packages ~90–100%). Go floor remains 1.24.

Fixed

• Dial logger → MMS — when DialOptions.Logger is set and
  DialOptions.MMS.Logger is nil, the IEC logger is passed through to
  iso.Dial / mms.Client (Server already did this).

Dependencies

• go-mms — v1.0.5 → v1.0.6
• go-cotp (indirect) — v1.0.2 → v1.0.3

Changed

• OBSERVABILITY.md / options godoc / doc.go — clarify IEC→MMS logger
  inheritance and that iso.WithLogger is independent.
• API.md — document IEDName on DialOptions/ClientOptions; note logger
  propagation.

Build / tooling

• Makefile — exports GOWORK=off; make fuzz runs the eight root fuzz
  targets plus FuzzParse in ./scl (replaces the stale “planned for M6”
  stub).

Tests

Coverage pass across client, server, SCL, and internal/servermodel
(approximate statement coverage: root ~90%, scl ~92%,
scl/validate 100%, scl/index ~93%, scl/internal/genir ~93%,
internal/servermodel ~87%). Notable additions:

• Values / Write / client helpers — type-mismatch and nil guards on
  accessors; Write validation edges; ldDomain / refToMMS /
  stripIEDPrefix.
• Server — installWriteInterceptor (RCB / SGCB / CO / DA notify),
  parseCOStoreKey / parseRCBStoreKey.
• Control / reports — Operate / Select / SelectWithValue / Cancel /
  ReadCtlModel / ReadLastApplError edges; buildCancel; OrCat /
  AddCause String; ListReportsVerified / verifyReportCandidates.
• Setting groups (client) — GetSettingGroupInfo, SelectActiveSG /
  SelectEditSG / ConfirmEditSG, GetEditSGValue / SetEditSGValue /
  GetActiveSGValue, decodeSGCB member-type edges; server
  GetEditSettingGroup.
• Data sets — List / Get / Read / Create / Delete validation and
  loopback paths; memberIdentity; lazy-cache ReadDataSet.
• SCL — Parse / ParseFile / ParseFileOpts / ParseWithOptions /
  ParseBytes (strict, MaxDiagnostics, read failures); DetectKind /
  KindFromPath; flatten GSE/SMV/ConnectedAP exports; index
  FindGSEControl / FindSMVControl; validate package edge matrix;
  v1.7 convert Private / SMV / SettingControl / LogControl; genir
  Emit / enums / types / SCL root / type-resolve helpers; sclparse
  list-smv / completion / version string.
• servermodel — registerSGCB, compound registerDA /
  registerDAWithFC, RCB register Read/Write via MMS loopback,
  makeStructRead / buildAttrElemAndRead.

No public API surface changes. No breaking changes.

Import path remains github.com/otfabric/go-iec61850.

v1.0.6

Fixed

• Report subscription overflow tests — TestSubscribeReport_QueueOverflow and
  TestSubscribeReport_OverflowDropOldest no longer use a fixed sleep plus non-blocking
  drain. They wait for the first delivered report (timeout) before draining the channel,
  which removes a flake under -race on busy CI (observed on Go 1.26).
• Report engine logging — removed accidental stderr debug prints from the URCB
  delayed-send path ([DBG] send OK / send failed). Failures remain on the structured
  logger.

No API changes. No breaking changes.

Import path remains github.com/otfabric/go-iec61850.

v1.0.5

Dependencies

• Bumped github.com/otfabric/go-mms from v1.0.4 → v1.0.5 (fix 32-bit / linux armv7 compile overflow in file PDU error formatting).

No API changes. No breaking changes.

Import path remains github.com/otfabric/go-iec61850.

v1.0.4

Documentation, lint hardening, and code-quality improvements. No API changes, no behavior changes.

Dependencies

• Bumped github.com/otfabric/go-mms from v1.0.3 → v1.0.4 (documentation and lint hardening; no API or behavior changes).
• Bumped github.com/otfabric/go-cotp (indirect) from v1.0.1 → v1.0.2.

Documentation — error taxonomy covering all 20 sentinel values, 7 typed error structs

(ReferenceError, DecodeError, ModelError, ReportError, SCLParseError,
DataAccessError, ControlError), underlying MMS error passthrough, and errors.Is /
errors.As usage patterns.

• Added link to ERRORS.md in README.md documentation table and repository file-tree section.

Linting and code quality

• golangci-lint exclusion-free (except two documented gocritic disables):
  • Removed blanket errcheck suppression for test files; all issues fixed in code.
  • Removed dead staticcheck SA2002 test-file exclusion (SA2002 does not occur in this repo).
  • ifElseChain disabled: three-branch if/else if/else patterns are preferred over switch
    for exclusive error-then-nil-then-value decisions.
  • exitAfterDefer disabled: Example_* documentation functions intentionally show
    defer client.Close followed by log.Fatal to model correct cleanup for users.
• Fixed unchecked error returns across 10 test files:
  • c.Abort, sub.Close, defer sub.Close → _ = ... or defer func() { _ = ... }()
  • srv.MMS().SetVariableRead(...) → wrapped in if err := ...; err != nil { t.Fatalf(...) }
  • srv.RegisterControl(...) in example_test.go → _ = srv.RegisterControl(...)
• Converted if/else if/else chains in bulk.go and dataset.go to switch statements.
• Fixed exitAfterDefer in all example programs (basic-client, control, files, reports,
  ied-client, ied-server) and scl/cmd/sclgen: moved defer cancel() / defer stop() to
  after the last potential fatal exit; explicit cleanup called before each log.Fatal.
• Removed unused test helper return values:
  • setupRCBLoopback dropped *mms.Server return (never used by any caller).
  • setupWritableLoopback dropped *writableVars return (never used by any caller).
  • executeCmd in scl/cmd/sclparse dropped string return (never used by any caller).
• Added unparam and gocritic linters to .golangci.yml.
• Added vuln target (govulncheck) to Makefile and wired it into make check.

No API changes. No breaking changes.

Import path remains github.com/otfabric/go-iec61850.

v1.0.3

Added: Recovery, concurrency, resource-pressure, and decoder-robustness hardening.

Recovery & lifecycle (reconnect_test.go)

• TestClientReconnect_AfterServerRestart — reconnect after server shutdown; new-port server model.
• TestClientReconnect_MultipleSequential — 5 sequential connect/close cycles without resource leak.
• TestClientReconnect_URCBResubscription — URCB re-established after reconnect on same server.
• TestClient_NoGoroutineLeakOnConnectDisconnect — 10 cycles; goroutine delta ≤ 3.
• TestServer_Close_StopsReportEngine — post-close connections refused immediately.
• TestClientReconnect_ReadAfterServerClose — reads return errors (not hang) after server gone.

BRCB EntryID resume (interop/brcb_resume_test.go, report_engine.go)

• Implemented decodeEntryID and filterEntriesAfter helpers.
• enableRCB reads the client's pre-written EntryID and filters buffer replay to entries strictly after that point.
• Policy: exclusive boundary — ID N means replay entries > N; zero means full replay; future ID means no replay.
• EntryIDs are 8-byte big-endian, monotonically increasing from 1, non-persistent across server restarts.
• PurgeBuf=true invalidates all previously issued EntryIDs.
• Three interop tests: Resume, ZeroResume (full buffer), ResumeFromFuture (no replay).

Bug fix: BRCB replay skipped after unconditional re-enable (report_engine.go)

• Root cause: when a BRCB generated a buffered entry it wrote EntryID to the value store. On re-enable, enableRCB read that server-written value as the resume filter, excluding the only buffered entry — so no replay was delivered.
• Fix: EntryID in the store is reset to all-zero bytes when RptEna=false is written. A subsequent re-enable with no client-written EntryID decodes to resumeID=0, which means full replay. Tests that explicitly write an EntryID before re-enabling are unaffected — they overwrite the cleared value before RptEna=true.
• Covered by TestGoServer_BRCB_Replay (was timing out, now passes).

Concurrent request hardening (concurrent_test.go)

• Context cancellation releases all in-flight confirmed requests.
• Asynchronous report delivery does not stall or corrupt concurrent read responses.
• Aborting the client while 20 writes are in flight — all goroutines exit cleanly.
• Timed-out requests do not accumulate goroutines (delta ≤ 3 after 10 timeouts).

Resource pressure tests (resource_exhaust_test.go)

• 50 sequential connections and 20 concurrent connections without descriptor leak.
• Report flood (30 GIs, queue-size=2) — reads succeed throughout; OverflowDropNewest drops silently.
• 10×200 concurrent SetValue with 100 simultaneous client reads — zero read errors.

SCL corpus expansion (scl_corpus_test.go)

• Multi-LN model (LLN0 + 3×GGIO + MMXU with AnalogueValue DAType/BDA).
• Multi-LD model (4 logical devices).
• SDO chain (DPC with Oper sub-object).
• Enum DAs (ENS with custom enum type).
• Multi-LN URCB report with cross-LN dataset members.

Report decoder robustness (additional fuzz targets in fuzz_test.go)

• FuzzDecodeReportIndication — arbitrary value arrays (4 seeds: minimal, empty, all-zeros, all-ones).
• FuzzDecodeOptFlds — arbitrary bit-string bytes for the OptFlds decoder.
• FuzzDecodeTrgOps — arbitrary bit-string bytes for the TrgOps decoder.
• FuzzDecodeReportIndication_NilValues — selective nil entries via fuzz-driven bit masks.

API documentation (example_test.go)

• Added Example* functions for Dial, SubscribeReport, Write, GetReportControlBlock, NewServer, SetValue, RegisterControl, and ParseRef.

Service profile (INTEROP.md)

• IEC 61850-7-2 service table (client + server columns).
• CDC conformance table with interop-tested column.
• Full report features table (URCB/BRCB, all OptFlds).
• New BRCB EntryID resume section with explicit exclusive-boundary contract, byte format, stability guarantees, overflow interaction, and purge invalidation.
• New Report backpressure and loss policy section documenting URCB vs. BRCB queue loss semantics.
• Known limitations and deferred features table.

Scheduled fuzz workflow (.github/workflows/fuzz.yml)

• Nightly 5-minute fuzz run per target, with workflow_dispatch override.
• Failing corpus entries uploaded as artifacts (30-day retention).

Race detector: go test -race ./... passes cleanly in both go-iec61850 and go-mms.

v1.0.2

Fixed: SBO/SBOw control server — connection-scoped ownership and ctlVal matching.

• controlRegistration now tracks selectConn *mms.ServerConn (SBO normal and SBOw contention) and selectCtlVal *mms.Value (SBOw value matching).
• executeSelect denies a second client's select when an active selection by a different connection exists; stale selections (owner disconnected or timed out) are cleared automatically.
• executeOperate (SBOw) rejects operates where the operating connection does not match the selecting connection (AddCauseSelectFailed) or where the ctlVal differs from the one provided at select time (AddCauseParameterChange).
• executeCancel enforces ownership for both SBO normal (connection identity) and SBOw (connection + origin identity).
• handleSBOSelectRead lazily clears a stale selection when the previous owner's connection is no longer active, allowing immediate re-selection by a new client.
• isConnActive helper queries the live mms.Server.Connections() list to determine whether a stored *ServerConn is still open.
• mmsValuesEqual helper compares two *mms.Value instances by type and byte content.

Added: ControlHandler.SelectTimeout — configurable per-control select reservation timeout.

When SelectTimeout > 0 in a ControlHandler, that duration overrides DefaultSelectTimeout (30 s) for that specific control object. Allows tests and applications to use short timeouts without changing the global default.

Fixed: Panic containment for ControlHandler callbacks.

callControlHandler wraps every invocation of OnSelect and OnOperate in a defer recover(). A panic in application callback code is caught and returned as a *ControlError instead of crashing the server goroutine.

Fixed: Panic containment for OnOverflow report callback.

deliver in report.go wraps the OverflowCallback invocation in a defer recover(), preventing an application panic from terminating the report delivery goroutine.

Fixed: RCB write interceptor value-restore on rejection.

internal/servermodel.registerRCB now saves the previous store value before calling vs.Set, and restores it if the write interceptor (e.g. ReportEngine.HandleRCBWrite) returns an error. This prevents a rejected URCB Resv or RptEna write from leaving the value store in an inconsistent state.

Fixed: URCB reservation and enable ownership enforcement.

ReportEngine.HandleRCBWrite now enforces connection-scoped ownership for Resv and RptEna writes:

• Resv=true is rejected with DataAccessErrorObjectAccessDenied if another active connection already holds the reservation.
• Resv=false is rejected if the clearing client does not own the reservation.
• RptEna=true is rejected for URCBs if the enabling client is not the reservation owner.
• Stale reservations (owner disconnected) are released automatically so a new client can reserve immediately.

Added: BRCB replay on re-enable.

ReportEngine.enableRCB now replays all buffered entries to the enabling connection when a BRCB is re-enabled with a non-empty buffer. Replay is delivered asynchronously via replayBRCBEntries after a 150 ms delay (to ensure the RptEna write response reaches the client before the first replayed report). ReportEngine.SetRCBBufMax allows test code to shrink the buffer for overflow testing without changing the default.

Added: DPS and BCR CDCs to the interop fixture.

interop/testdata/interop.icd (and the matching mms-interop fixture) now includes:

• GGIO1.DPS1 — double-point status (Dbpos 2-bit BitString, cdc=DPS).
• MMTR1.TotVAh — binary counter reading (INT32U, cdc=BCR).
• brcb01 buffered report control block with entryID=true and bufOvfl=true in OptFields.

Added: Interop test coverage for new phases.

New test files gated behind -tags=interop:

• interop/brcb_test.go — TestGoServer_BRCB_EntryID, _Replay, _Purge, _Overflow.
• interop/cdc_test.go — DPS and BCR read tests in all four directions (adapter directions skip pending mms-interop image rebuild).
• interop/quality_timestamp_test.go — Quality validity states (good/invalid/questionable/detail-bits), UTC timestamp round-trip, quality flags (LeapSecondsKnown, ClockNotSynchronized), and fractional-second accuracy sub-tests.
• interop/sbo_state_test.go — Full SBO/SBOw state-machine suite: cancel by non-owner, configurable select timeout, repeated select, second-client contention, disconnect releases selection, SBOw ctlVal mismatch, SBOw second-client contention.
• interop/urcb_reservation_test.go — Double-reserve same/different connection, enable without ownership, disconnect releases reservation.
• interop/urcb_integrity_test.go — Integrity-period delivery, coexistence with dchg, disable stops timer.
• interop/urcb_trigger_test.go — Data-change, quality-change, data-update, no-dchg-on-same-value, multiple-trigger coalescing.
• interop/multi_client_test.go — Concurrent reads (5 clients), concurrent writes to independent variables, invoke-ID isolation (3 clients × 10 reads), disconnect-one-keeps-others.
• interop/dataset_depth_test.go additions — TestGoServer_DS_WritePartialFail (type-mismatch partial failure in WriteMultiple), TestGoServer_DS_NestedDORead (structured MX read of TotW.mag).

v1.0.1

Added: MIT LICENSE with copyright Copyright (c) 2026 OT Fabric.

Added: // SPDX-License-Identifier: MIT headers on first-party Go sources (generated scl/internal/raw code left unchanged).

Changed: README license section and badge block for public release — added pkg.go.dev, removed Go Report Card, and switched Codecov to a tokenless public badge URL.

v1.0.0

Changed: Bump dependencies to stable releases (go-mms v1.0.0, go-cotp v1.0.1).

Added: DialOptions.IEDName — when set, the client prepends the IED identifier to every MMS domain name it sends and strips it from domain names returned by the server. Callers can always use bare LD instance names regardless of whether the target is a stand-alone Go server (no prefix) or a full IEC 61850 server with a vendor IED name.

Added: SBO normal (select-before-operate, ctlModel=2) — Client.Select reads SBO[CO] and grants/denies ownership per connection; Server.RegisterControl with CtlModelSBONormal installs a read-interceptor that enforces single-owner semantics. executeOperate checks the owning connection identity for SBO normal and the originator identity for SBO enhanced, so both paths share a single control-execution function.

Added: SBO enhanced (select-before-operate with enhanced security, ctlModel=4) — Client.SelectWithValue sends an SBOw[CO] write containing a full Oper structure; Server.RegisterControl with CtlModelSBOEnhanced validates that the ctlNum in the subsequent Operate matches the one used at select time. Cancel clears the select reservation for both SBO models.

Added: Client.Cancel sends an MMS write to Cancel[CO], releasing any SBO reservation held by the caller.

Fixed: OperateParams / CancelParams Oper structure encoding — operTm is now omitted from the encoded structure when not set, instead of sending a zero-time seventh element. Several IEC 61850 servers (including libiec61850 and iec61850bean) define OperSPC_Type without operTm and reject a seven-element structure with TypeInconsistent.

Fixed: Server.RegisterControl now correctly handles the CtlModelSBOEnhanced (ctlModel=4) path: executeOperate validates ctlNum consistency between SelectWithValue and Operate, and executeCancel clears both selectOwner and selectCtlNum.

Added: General interrogation — Client.TriggerGI sends an RptEna+GI write sequence; the report engine emits a GI report carrying all dataset members with ReasonGeneralInterrogation set in the inclusion bits.

Fixed: Report engine multi-member dchg — writes to multiple dataset members in a single MMS Write now correctly produce one report containing all changed members rather than emitting separate per-member reports or silently dropping later changes.

Added: Server SetVariableRead(domain, itemID, fn) — overrides the MMS read function for an already-registered variable at runtime. Used internally by RegisterControl for SBO normal; also available to applications that need custom read-time behaviour.

Changed: internal/servermodel.Register now includes RP/BR functional-constraint groups in the LN TypeSpec so that external tools (e.g. iec61850bean) can discover URCBs via GetVariableAccessAttributes.

Fixed: buildRCBFields stores DatSet as a fully-qualified domain/LNName$dsName reference so that iec61850bean's processReport can resolve the dataset from its ServerModel.

Fixed: SCL ctlModel DAI values are now emitted as enum name strings (direct-with-normal-security, sbo-with-normal-security, etc.) rather than ordinals, for compatibility with iec61850bean's SCL parser.

Changed: Examples directory renamed from _examples/ to examples/.

Added: interop/ test suite — consumed via -tags=interop; exercises go-iec61850 against live libiec61850 and iec61850bean adapters from mms-interop. Covers: basic operations, URCB reporting (dchg, GI, multi-member), dataset depth, negative/error cases, direct control, SBO normal, and SBO enhanced (SBOw). See INTEROP.md for the full compatibility matrix.

Added: .github/workflows/interop.yml — CI workflow that runs the full interop suite against pinned mms-interop adapter images.

v0.1.3

Changed: CI/release pipeline, SCL tooling, and documentation overhaul.

• Add GitHub Actions CI (ci.yml) and release (release.yml) workflows for package and binary releases.
• sclgen and sclparse binaries now embed full build metadata via ldflags (version, tag, commit, buildDate) and expose it through a dedicated version subcommand.
• Makefile build targets derive version from git tags instead of version.txt files.
• SCL model: add topology LNode references on Substation, VoltageLevel, and Bay; lossless Private.InnerXML capture.
• SCL validation: add topology LNode resolution, GOOSE/SMV cbName linkage checks; deprecate scl.Validate() in favour of scl/validate.All().
• SCL CLI: add list-goose, list-smv, list-connected-ap, list-types, and inspect commands; deprecate ParseWithOptions/ParseFileWithOptions.
• Add content-based DetectKind for document classification.
• New API.md (merged from ERRORS.md); updated KNOWN_LIMITATIONS.md, OBSERVABILITY.md, interop/README.md.