Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/common/opcua/client.go

@@ -0,0 +1,241 @@
+package opcua
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log" //nolint:depguard // just for debug
+	"net/url"
+	"strconv"
+	"time"
+
+	"github.com/gopcua/opcua"
+	"github.com/gopcua/opcua/debug"
+	"github.com/gopcua/opcua/ua"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/config"
+	"github.com/influxdata/telegraf/internal/choice"
+)
+
+type OpcUAWorkarounds struct {
+	AdditionalValidStatusCodes []string `toml:"additional_valid_status_codes"`
+}
+
+type ConnectionState opcua.ConnState
+
+const (
+	Closed       ConnectionState = ConnectionState(opcua.Closed)
+	Connected    ConnectionState = ConnectionState(opcua.Connected)
+	Connecting   ConnectionState = ConnectionState(opcua.Connecting)
+	Disconnected ConnectionState = ConnectionState(opcua.Disconnected)
+	Reconnecting ConnectionState = ConnectionState(opcua.Reconnecting)
+)
+
+func (c ConnectionState) String() string {
+	return opcua.ConnState(c).String()
+}
+
+type OpcUAClientConfig struct {
+	Endpoint       string          `toml:"endpoint"`
+	SecurityPolicy string          `toml:"security_policy"`
+	SecurityMode   string          `toml:"security_mode"`
+	Certificate    string          `toml:"certificate"`
+	PrivateKey     string          `toml:"private_key"`
+	Username       config.Secret   `toml:"username"`
+	Password       config.Secret   `toml:"password"`
+	AuthMethod     string          `toml:"auth_method"`
+	ConnectTimeout config.Duration `toml:"connect_timeout"`
+	RequestTimeout config.Duration `toml:"request_timeout"`
+	ClientTrace    bool            `toml:"client_trace"`
+
+	OptionalFields []string         `toml:"optional_fields"`
+	Workarounds    OpcUAWorkarounds `toml:"workarounds"`
+	SessionTimeout config.Duration  `toml:"session_timeout"`
+}
+
+func (o *OpcUAClientConfig) Validate() error {
+	if err := o.validateOptionalFields(); err != nil {
+		return fmt.Errorf("invalid 'optional_fields': %w", err)
+	}
+
+	return o.validateEndpoint()
+}
+
+func (o *OpcUAClientConfig) validateOptionalFields() error {
+	validFields := []string{"DataType"}
+	return choice.CheckSlice(o.OptionalFields, validFields)
+}
+
+func (o *OpcUAClientConfig) validateEndpoint() error {
+	if o.Endpoint == "" {
+		return errors.New("endpoint url is empty")
+	}
+
+	_, err := url.Parse(o.Endpoint)
+	if err != nil {
+		return errors.New("endpoint url is invalid")
+	}
+
+	switch o.SecurityPolicy {
+	case "None", "Basic128Rsa15", "Basic256", "Basic256Sha256", "auto":
+	default:
+		return fmt.Errorf("invalid security type %q in %q", o.SecurityPolicy, o.Endpoint)
+	}
+
+	switch o.SecurityMode {
+	case "None", "Sign", "SignAndEncrypt", "auto":
+	default:
+		return fmt.Errorf("invalid security type %q in %q", o.SecurityMode, o.Endpoint)
+	}
+
+	return nil
+}
+
+func (o *OpcUAClientConfig) CreateClient(telegrafLogger telegraf.Logger) (*OpcUAClient, error) {
+	err := o.Validate()
+	if err != nil {
+		return nil, err
+	}
+
+	if o.ClientTrace {
+		debug.Enable = true
+		debug.Logger = log.New(&DebugLogger{Log: telegrafLogger}, "", 0)
+	}
+
+	c := &OpcUAClient{
+		Config: o,
+		Log:    telegrafLogger,
+	}
+	c.Log.Debug("Initialising OpcUAClient")
+
+	err = c.setupWorkarounds()
+	return c, err
+}
+
+type OpcUAClient struct {
+	Config *OpcUAClientConfig
+	Log    telegraf.Logger
+
+	Client *opcua.Client
+
+	opts  []opcua.Option
+	codes []ua.StatusCode
+}
+
+// / setupOptions read the endpoints from the specified server and setup all authentication
+func (o *OpcUAClient) SetupOptions() error {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Duration(o.Config.ConnectTimeout))
+	defer cancel()
+	// Get a list of the endpoints for our target server
+	endpoints, err := opcua.GetEndpoints(ctx, o.Config.Endpoint)
+	if err != nil {
+		return err
+	}
+
+	if o.Config.Certificate == "" && o.Config.PrivateKey == "" {
+		if o.Config.SecurityPolicy != "None" || o.Config.SecurityMode != "None" {
+			o.Log.Debug("Generating self-signed certificate")
+			cert, privateKey, err := generateCert("urn:telegraf:gopcua:client", 2048,
+				o.Config.Certificate, o.Config.PrivateKey, 365*24*time.Hour)
+			if err != nil {
+				return err
+			}
+
+			o.Config.Certificate = cert
+			o.Config.PrivateKey = privateKey
+		}
+	}
+
+	o.Log.Debug("Configuring OPC UA connection options")
+	o.opts, err = o.generateClientOpts(endpoints)
+
+	return err
+}
+
+func (o *OpcUAClient) setupWorkarounds() error {
+	o.codes = []ua.StatusCode{ua.StatusOK}
+	for _, c := range o.Config.Workarounds.AdditionalValidStatusCodes {
+		val, err := strconv.ParseUint(c, 0, 32) // setting 32 bits to allow for safe conversion
+		if err != nil {
+			return err
+		}
+		o.codes = append(o.codes, ua.StatusCode(val))
+	}
+
+	return nil
+}
+
+func (o *OpcUAClient) StatusCodeOK(code ua.StatusCode) bool {
+	for _, val := range o.codes {
+		if val == code {
+			return true
+		}
+	}
+	return false
+}
+
+// Connect to an OPC UA device
+func (o *OpcUAClient) Connect(ctx context.Context) error {
+	o.Log.Debug("Connecting OPC UA Client to server")
+	u, err := url.Parse(o.Config.Endpoint)
+	if err != nil {
+		return err
+	}
+
+	switch u.Scheme {
+	case "opc.tcp":
+		if err := o.SetupOptions(); err != nil {
+			return err
+		}
+
+		if o.Client != nil {
+			o.Log.Warnf("Closing connection to %q as already connected", u)
+			if err := o.Client.Close(ctx); err != nil {
+				// Only log the error but to not bail-out here as this prevents
+				// reconnections for multiple parties (see e.g. #9523).
+				o.Log.Errorf("Closing connection failed: %v", err)
+			}
+		}
+
+		o.Client, err = opcua.NewClient(o.Config.Endpoint, o.opts...)
+		if err != nil {
+			return fmt.Errorf("error in new client: %w", err)
+		}
+		ctx, cancel := context.WithTimeout(context.Background(), time.Duration(o.Config.ConnectTimeout))
+		defer cancel()
+		if err := o.Client.Connect(ctx); err != nil {
+			return fmt.Errorf("error in Client Connection: %w", err)
+		}
+		o.Log.Debug("Connected to OPC UA Server")
+
+	default:
+		return fmt.Errorf("unsupported scheme %q in endpoint. Expected opc.tcp", u.Scheme)
+	}
+	return nil
+}
+
+func (o *OpcUAClient) Disconnect(ctx context.Context) error {
+	o.Log.Debug("Disconnecting from OPC UA Server")
+	u, err := url.Parse(o.Config.Endpoint)
+	if err != nil {
+		return err
+	}
+
+	switch u.Scheme {
+	case "opc.tcp":
+		// We can't do anything about failing to close a connection
+		err := o.Client.Close(ctx)
+		o.Client = nil
+		return err
+	default:
+		return errors.New("invalid controller")
+	}
+}
+
+func (o *OpcUAClient) State() ConnectionState {
+	if o.Client == nil {
+		return Disconnected
+	}
+	return ConnectionState(o.Client.State())
+}