From 1fb0f6665d05b9ecec23fba8fc5d260a3fa7e722 Mon Sep 17 00:00:00 2001
From: Huang Huang <mozillazg101@gmail.com>
Date: Sat, 20 Jul 2024 10:02:12 +0800
Subject: [PATCH] improve compatibility with OpenCloudOS 7/8/9 and TencentOS
 Server 2.4/3.1 (#91)

closes #89
---
 bpf/bpf.go        |  8 +++++---
 bpf/bpf_legacy.go | 10 +++++++---
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/bpf/bpf.go b/bpf/bpf.go
index 70669eff..38658321 100644
--- a/bpf/bpf.go
+++ b/bpf/bpf.go
@@ -149,7 +149,8 @@ func (b *BPF) Load(opts Options) error {
 		}
 	}
 
-	if b.isLegacyKernel || !supportGetSocketCookieWithCgroup() {
+	if b.isLegacyKernel || !supportCgroupSock() {
+		log.Debug("will load the objs for legacy kernel")
 		b.skipAttachCgroup = true
 		objs := BpfObjectsForLegacyKernel{}
 		if err = b.spec.LoadAndAssign(&objs, &ebpf.CollectionOptions{
@@ -261,6 +262,7 @@ func (b *BPF) AttachKprobes() error {
 
 	lk, err = link.Kprobe("udp_send_skb", b.objs.KprobeUdpSendSkb, &link.KprobeOptions{})
 	if err != nil {
+		log.Debugf("%+v", err)
 		if strings.Contains(err.Error(), "no such file or directory") {
 			lk, err = link.Kprobe("udp_sendmsg", b.objs.KprobeUdpSendmsg, &link.KprobeOptions{})
 			if err != nil {
@@ -276,7 +278,7 @@ func (b *BPF) AttachKprobes() error {
 		b.objs.KprobeNfNatPacket, &link.KprobeOptions{})
 	if err != nil {
 		if strings.Contains(err.Error(), "nf_nat_packet: not found: no such file or directory") {
-			log.Warn("current system doest not enable netfilter based NAT feature, skip attach kprobe/nf_nat_packet")
+			log.Warn("the kernel does not support netfilter based NAT feature, skip attach kprobe/nf_nat_packet")
 		} else {
 			return fmt.Errorf("attach kprobe/nf_nat_packet: %w", err)
 		}
@@ -289,7 +291,7 @@ func (b *BPF) AttachKprobes() error {
 		b.objs.KprobeNfNatManipPkt, &link.KprobeOptions{})
 	if err != nil {
 		if strings.Contains(err.Error(), "nf_nat_manip_pkt: not found: no such file or directory") {
-			log.Warn("current system doest not enable netfilter based NAT feature, skip attach kprobe/nf_nat_manip_pkt")
+			log.Warn("the kernel does not support netfilter based NAT feature, skip attach kprobe/nf_nat_manip_pkt")
 		} else {
 			return fmt.Errorf("attach kprobe/nf_nat_manip_pkt: %w", err)
 		}
diff --git a/bpf/bpf_legacy.go b/bpf/bpf_legacy.go
index ece708f8..8fca688f 100644
--- a/bpf/bpf_legacy.go
+++ b/bpf/bpf_legacy.go
@@ -45,12 +45,16 @@ func (b *BpfObjects) FromLegacy(o *BpfObjectsForLegacyKernel) {
 	b.BpfMaps = o.BpfMaps
 }
 
-func supportGetSocketCookieWithCgroup() bool {
-	err := features.HaveProgramHelper(ebpf.CGroupSock, asm.FnGetSocketCookie)
-	if err != nil {
+func supportCgroupSock() bool {
+	if err := features.HaveProgramHelper(ebpf.CGroupSock, asm.FnGetSocketCookie); err != nil {
 		log.Debugf("%+v", err)
 		return false
 	}
+	if err := features.HaveProgramHelper(ebpf.CGroupSock, asm.FnGetCurrentTask); err != nil {
+		log.Debugf("%+v", err)
+		return false
+	}
+
 	return true
 }