tetragon: Add support to pass options for spec

Adding support to process options passed in spec for kprobe sensor.

At the moment the only supported option is to disable kprobe multi
(like global --disable=-kprobe-multi option).

Signed-off-by: Jiri Olsa <[email protected]>

pkg/sensors/tracing/generickprobe.go

@@ -508,11 +508,19 @@ func createGenericKprobeSensor(
 	kprobes := spec.KProbes
 	lists := spec.Lists
 
+	options, err := getKprobeOptions(spec.Options)
+	if err != nil {
+		return nil, fmt.Errorf("failed to set options: %s", err)
+	}
+
 	// use multi kprobe only if:
+	// - it's not disable via spec options
 	// - it's not disabled by user
 	// - there's support detected
-	useMulti = !option.Config.DisableKprobeMulti &&
-		bpf.HasKprobeMulti()
+	if !options.DisableKprobeMulti {
+		useMulti = !option.Config.DisableKprobeMulti &&
+			bpf.HasKprobeMulti()
+	}
 
 	in := addKprobeIn{
 		useMulti:      useMulti,

pkg/sensors/tracing/options.go

@@ -0,0 +1,51 @@
+package tracing
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/cilium/tetragon/pkg/k8s/apis/cilium.io/v1alpha1"
+	"github.com/cilium/tetragon/pkg/logger"
+	"github.com/cilium/tetragon/pkg/option"
+)
+
+type kprobeOptions struct {
+	DisableKprobeMulti bool
+}
+
+func getKprobeOptions(specs []v1alpha1.OptionSpec) (*kprobeOptions, error) {
+	type opt struct {
+		name string
+		set  func(val string) error
+	}
+
+	options := &kprobeOptions{}
+
+	var opts = []opt{
+		opt{
+			// local --disable-kprobe-multi
+			name: option.KeyDisableKprobeMulti,
+			set: func(str string) (err error) {
+				options.DisableKprobeMulti, err = strconv.ParseBool(str)
+				return err
+			},
+		},
+	}
+
+	for i := range specs {
+		spec := specs[i]
+
+		for j := range opts {
+			opt := opts[j]
+
+			if opt.name == spec.Name {
+				if err := opt.set(spec.Value); err != nil {
+					return nil, fmt.Errorf("failed to set option %s: %s", opt.name, err)
+				}
+				logger.GetLogger().Infof("Set option %s = %s", spec.Name, spec.Value)
+			}
+		}
+	}
+
+	return options, nil
+}