initial client and server implementations

.gitmodules

@@ -13,6 +13,6 @@
 [submodule "src/c++/deps/opendnp3"]
 	path = src/c++/deps/opendnp3
 	url = https://github.com/dnp3/opendnp3.git
-[submodule "src/go/sunspec/models"]
-	path = src/go/sunspec/models
+[submodule "src/go/sunspec/common/models"]
+	path = src/go/sunspec/common/models
 	url = https://github.com/sunspec/models.git

src/go/Makefile

@@ -44,8 +44,8 @@ clean:
 	$(RM) bin/ot-sim-tailscale-module
 	$(RM) bin/ot-sim-telnet-module
 
-sunspec/types.go: sunspec/models/json/schema.json bin/go-jsonschema
-	$(GOBIN)/go-jsonschema -p sunspec -o sunspec/types.go sunspec/models/json/schema.json
+sunspec/common/types.go: sunspec/common/models/json/schema.json bin/go-jsonschema
+	$(GOBIN)/go-jsonschema -p common -o sunspec/common/types.go sunspec/common/models/json/schema.json
 
 MSGBUS_SOURCES := $(shell find msgbus \( -name '*.go' \))
 
@@ -81,7 +81,7 @@ bin/ot-sim-node-red-module: $(NODERED_SOURCES)
 
 SUNSPEC_SOURCES := $(shell find sunspec \( -name '*.go' \))
 
-bin/ot-sim-sunspec-module: $(SUNSPEC_SOURCES) sunspec/types.go
+bin/ot-sim-sunspec-module: $(SUNSPEC_SOURCES) $(MSGBUS_SOURCES)
 	mkdir -p bin
 	GOOS=linux go build -a -ldflags="-s -w" -trimpath -o bin/ot-sim-sunspec-module cmd/ot-sim-sunspec-module/main.go
 

src/go/cmd/ot-sim-sunspec-module/main.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+
+	otsim "github.com/patsec/ot-sim"
+	"github.com/patsec/ot-sim/util"
+	"github.com/patsec/ot-sim/util/sigterm"
+
+	// This will cause the SunSpec module to register itself with the otsim package
+	// so it gets run by the otsim.Start function below.
+	_ "github.com/patsec/ot-sim/sunspec"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		panic("path to config file not provided")
+	}
+
+	if err := otsim.ParseConfigFile(os.Args[1]); err != nil {
+		fmt.Printf("Error parsing config file: %v\n", err)
+		os.Exit(util.ExitNoRestart)
+	}
+
+	ctx := sigterm.CancelContext(context.Background())
+
+	if err := otsim.Start(ctx); err != nil {
+		fmt.Printf("Error starting SunSpec module: %v\n", err)
+
+		var exitErr util.ExitError
+		if errors.As(err, &exitErr) {
+			os.Exit(exitErr.ExitCode)
+		}
+
+		os.Exit(1)
+	}
+
+	<-ctx.Done()
+
+	if err := ctx.Err(); err != nil && !errors.Is(err, context.Canceled) {
+		fmt.Printf("Error running SunSpec module: %v\n", err)
+
+		var exitErr util.ExitError
+		if errors.As(err, &exitErr) {
+			os.Exit(exitErr.ExitCode)
+		}
+
+		os.Exit(1)
+	}
+}

src/go/sunspec/README.md

@@ -25,4 +25,8 @@ OT-sim tags?
 How do we want to specify point scalings?
 
   * map scaling values to SF values?
-  * have deault scaling values for SF's that can be overwritten?
+  * have deault scaling values for SF's that can be overwritten?
+
+## TODO
+
+* [ ] Build out initial Model 1 (static data)

src/go/sunspec/client/client.go

@@ -0,0 +1,191 @@
+package client
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+
+	"github.com/beevik/etree"
+	otsim "github.com/patsec/ot-sim"
+	"github.com/patsec/ot-sim/sunspec/common"
+
+	"actshad.dev/modbus"
+)
+
+type Factory struct{}
+
+func (Factory) NewModule(e *etree.Element) (otsim.Module, error) {
+	name := e.SelectAttrValue("name", "sunspec")
+	return New(name), nil
+}
+
+type SunSpecClient struct {
+	pullEndpoint string
+	pubEndpoint  string
+
+	name     string
+	id       int
+	endpoint string
+
+	models    []int
+	registers map[int]common.Register
+}
+
+func New(name string) *SunSpecClient {
+	return &SunSpecClient{
+		name:      name,
+		registers: make(map[int]common.Register),
+	}
+}
+
+func (this SunSpecClient) Name() string {
+	return this.name
+}
+
+func (this *SunSpecClient) Configure(e *etree.Element) error {
+	for _, child := range e.ChildElements() {
+		switch child.Tag {
+		case "pull-endpoint":
+			this.pullEndpoint = child.Text()
+		case "pub-endpoint":
+			this.pubEndpoint = child.Text()
+		case "endpoint":
+			this.endpoint = child.Text()
+		case "model":
+			attr := child.SelectAttr("id")
+			if attr == nil {
+				return fmt.Errorf("missing 'id' attribute for SunSpec model")
+			}
+
+			id, err := strconv.Atoi(attr.Value)
+			if err != nil {
+				return fmt.Errorf("parsing model ID %s: %w", attr.Value, err)
+			}
+
+			this.models = append(this.models, id)
+		}
+	}
+
+	return nil
+}
+
+func (this *SunSpecClient) Run(ctx context.Context, pubEndpoint, pullEndpoint string) error {
+	var handler modbus.ClientHandler
+
+	handler = modbus.NewTCPClientHandler(this.endpoint)
+	handler.(*modbus.TCPClientHandler).SlaveId = byte(this.id)
+
+	client := modbus.NewClient(handler)
+
+	r := common.IdentifierRegister
+
+	data, err := client.ReadHoldingRegisters(40000, uint16(r.Count))
+	if err != nil {
+		return fmt.Errorf("reading identifier from SunSpec device %s: %w", this.endpoint, err)
+	}
+
+	value, err := r.Value(data)
+	if err != nil {
+		return fmt.Errorf("parsing identifier from SunSpec device %s: %w", this.endpoint, err)
+	}
+
+	if value != common.SunSpecIdentifier {
+		return fmt.Errorf("invalid identifier provided by remote device")
+	}
+
+	// start addr at 40002 after well known identifier
+	addr := 40002
+
+	r = common.Register{DataType: "uint16"}
+
+	if err := r.Init(); err != nil {
+		return fmt.Errorf("initializing generic model register %d: %w", addr, err)
+	}
+
+	data, err = client.ReadHoldingRegisters(uint16(addr), uint16(r.Count))
+	if err != nil {
+		return fmt.Errorf("reading model ID from SunSpec device %s: %w", this.endpoint, err)
+	}
+
+	value, err = r.Value(data)
+	if err != nil {
+		return fmt.Errorf("parsing model ID from SunSpec device %s: %w", this.endpoint, err)
+	}
+
+	if value != 1 {
+		return fmt.Errorf("remote SunSpec device missing required Model 1")
+	}
+
+	addr += r.Count
+
+	data, err = client.ReadHoldingRegisters(uint16(addr), uint16(r.Count))
+	if err != nil {
+		return fmt.Errorf("reading model 1 length from SunSpec device %s: %w", this.endpoint, err)
+	}
+
+	value, err = r.Value(data)
+	if err != nil {
+		return fmt.Errorf("parsing model 1 length from SunSpec device %s: %w", this.endpoint, err)
+	}
+
+	addr += r.Count
+
+	data, err = client.ReadHoldingRegisters(uint16(addr), uint16(value))
+	if err != nil {
+		return fmt.Errorf("reading rest of model 1 data from SunSpec device %s: %w", this.endpoint, err)
+	}
+
+	model, err := common.GetModelSchema(1)
+	if err != nil {
+		return fmt.Errorf("getting model schema: %w", err)
+	}
+
+	// track position of current model data array
+	var pos int
+
+	for idx, point := range model.Group.Points {
+		if idx < 2 {
+			continue
+		}
+
+		dt := string(point.Type)
+		if dt == string(common.PointTypeString) {
+			dt = fmt.Sprintf("string%d", point.Size)
+		}
+
+		r := common.Register{
+			DataType: dt,
+			Tag:      point.Name,
+		}
+
+		if err := r.Init(); err != nil {
+			return fmt.Errorf("initializing register %d: %w", addr, err)
+		}
+
+		bytes := data[pos : pos+(point.Size*2)]
+
+		if point.Type == common.PointTypeString {
+			value, err := r.String(bytes)
+			if err != nil {
+				return fmt.Errorf("parsing string value for SunSpec point: %w", err)
+			}
+
+			fmt.Printf("%s - %s\n", point.Name, value)
+		} else {
+			value, err := r.Value(bytes)
+			if err != nil {
+				return fmt.Errorf("parsing value for SunSpec point: %w", err)
+			}
+
+			fmt.Printf("%s - %f\n", point.Name, value)
+		}
+
+		pos += point.Size * 2
+	}
+
+	return nil
+}
+
+func (this SunSpecClient) log(format string, a ...any) {
+	fmt.Printf("[%s] %s\n", this.name, fmt.Sprintf(format, a...))
+}

src/go/sunspec/common/common.go

@@ -0,0 +1,32 @@
+package common
+
+var SunSpecIdentifier = float64(1400204883)
+
+var IdentifierRegister = Register{
+	DataType:      "uint32",
+	InternalValue: SunSpecIdentifier,
+}
+
+var EndRegister = Register{
+	DataType:      "uint16",
+	InternalValue: 65535,
+}
+
+var EndRegisterLength = Register{
+	DataType:      "uint16",
+	InternalValue: 0,
+}
+
+func init() {
+	if err := IdentifierRegister.Init(); err != nil {
+		panic(err)
+	}
+
+	if err := EndRegister.Init(); err != nil {
+		panic(err)
+	}
+
+	if err := EndRegisterLength.Init(); err != nil {
+		panic(err)
+	}
+}