From cdb7e95bf47d82a5f95595e302f3486901b64fa3 Mon Sep 17 00:00:00 2001
From: Ian Chen <ychen.cs10@nycu.edu.tw>
Date: Thu, 13 Feb 2025 23:17:13 +0800
Subject: [PATCH] fix: ci failed & update API based on reviewer's comments

---
 link.go                     |  4 ++++
 map.go                      | 24 +++++++++++++++++-------
 selftest/struct-ops/go.mod  |  2 +-
 selftest/struct-ops/main.go | 16 ++++++++++++----
 4 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/link.go b/link.go
index a5990872..bfd8f9ba 100644
--- a/link.go
+++ b/link.go
@@ -33,6 +33,7 @@ const (
 	CgroupLegacy
 	Netns
 	Iter
+	StructOps
 )
 
 //
@@ -47,6 +48,7 @@ type bpfLinkLegacy struct {
 type BPFLink struct {
 	link      *C.struct_bpf_link
 	prog      *BPFProg
+	m         *BPFMap
 	linkType  LinkType
 	eventName string
 	legacy    *bpfLinkLegacy // if set, this is a fake BPFLink
@@ -59,6 +61,8 @@ func (l *BPFLink) DestroyLegacy(linkType LinkType) error {
 			l.legacy.cgroupDir,
 			l.legacy.attachType,
 		)
+		// case StructOps:
+		// 	return l.m.DetachStructOps(l.link)
 	}
 
 	return fmt.Errorf("unable to destroy legacy link")
diff --git a/map.go b/map.go
index 5aa634be..ed4cad64 100644
--- a/map.go
+++ b/map.go
@@ -7,7 +7,6 @@ package libbpfgo
 import "C"
 
 import (
-	"errors"
 	"fmt"
 	"syscall"
 	"unsafe"
@@ -74,17 +73,28 @@ func (m *BPFMap) ReuseFD(fd int) error {
 	return nil
 }
 
-func (m *BPFMap) AttachStructOps() error {
-	if m.Type().String() != MapTypeStructOps.String() {
-		return errors.New("Map type should be BPF_MAP_TYPE_STRUCT_OPS")
-	}
+func (m *BPFMap) AttachStructOps() (*BPFLink, error) {
 	linkC, errno := C.bpf_map__attach_struct_ops(m.bpfMap)
 	if linkC == nil {
-		return fmt.Errorf("Map attach failed: %v", &errno)
+		return nil, fmt.Errorf("failed to attach struct_ops: %w", errno)
 	}
-	return nil
+	return &BPFLink{
+		link:      linkC,
+		m:         m,
+		linkType:  StructOps,
+		eventName: fmt.Sprintf("structOps-%s", m.Name()),
+	}, nil
 }
 
+// func (m *BPFMap) DetachStructOps(l *C.struct_bpf_link) error {
+// 	retC := C.bpf_link__detach_struct_ops(l)
+// 	if retC < 0 {
+// 		return fmt.Errorf("failed to detach struct_ops: %w", syscall.Errno(-retC))
+// 	}
+
+// 	return nil
+// }
+
 func (m *BPFMap) Name() string {
 	return C.GoString(C.bpf_map__name(m.bpfMap))
 }
diff --git a/selftest/struct-ops/go.mod b/selftest/struct-ops/go.mod
index 72a57bd7..d24b6b41 100644
--- a/selftest/struct-ops/go.mod
+++ b/selftest/struct-ops/go.mod
@@ -1,4 +1,4 @@
-module github.com/aquasecurity/libbpfgo/selftest/perfbuffers
+module github.com/aquasecurity/libbpfgo/selftest/struct-ops
 
 go 1.21
 
diff --git a/selftest/struct-ops/main.go b/selftest/struct-ops/main.go
index d1ddecd3..97b9151a 100644
--- a/selftest/struct-ops/main.go
+++ b/selftest/struct-ops/main.go
@@ -43,6 +43,8 @@ func main() {
 
 	m := bpfModule
 
+	var afterFunc func()
+
 	iters := m.Iterator()
 	for {
 		m := iters.NextMap()
@@ -50,9 +52,16 @@ func main() {
 			break
 		}
 		if m.Type().String() == "BPF_MAP_TYPE_STRUCT_OPS" {
-			if err := m.AttachStructOps(); err != nil {
+			if link, err := m.AttachStructOps(); err != nil {
 				log.Printf("error: %v", err)
 				os.Exit(-1)
+			} else {
+				afterFunc = func() {
+					if err := link.Destroy(); err != nil {
+						log.Printf("error: %v", err)
+						os.Exit(-1)
+					}
+				}
 			}
 		}
 	}
@@ -82,6 +91,7 @@ func main() {
 		time.Sleep(3 * time.Second)
 		cancel()
 		wg.Wait()
+		afterFunc()
 		log.Println("scheduler exit")
 		os.Exit(0)
 	}
@@ -91,9 +101,8 @@ func getStat(m *bpf.BPFMap) []uint64 {
 	cpuNum, err := bpf.NumPossibleCPUs()
 	if err != nil {
 		log.Fatal(err)
-		os.Exit(-1)
 	}
-	var cnts [][]uint64 = make([][]uint64, 2)
+	cnts := make([][]uint64, 2)
 	cnts[0] = make([]uint64, cpuNum)
 	cnts[1] = make([]uint64, cpuNum)
 	stats := []uint64{0, 0}
@@ -101,7 +110,6 @@ func getStat(m *bpf.BPFMap) []uint64 {
 		v, err := m.GetValue(unsafe.Pointer(&i))
 		if err != nil {
 			log.Fatal(err)
-			os.Exit(-1)
 		}
 		for cpu := 0; cpu < cpuNum; cpu++ {
 			n := v[cpu*8 : cpu*8+8]