optimize(bpf): Skip attaching {tcp,udp}_send* hooks when cgroup hooks…

… are attached (#197) * optimize(bpf): Skip attaching {tcp,udp}_send* hooks when cgroup hooks are attached * fix missing `tcnl.SetOption(netlink.ExtendedAcknowledge, true)` * remove fallbak dir when not found cgroup v2 root dir * fix `-i any` will cause an error when running on Alibaba Cloud Linux (Aliyun Linux) release 2.1903 LTS
mozillazg · Nov 30, 2024 · 1277cdb · 1277cdb
1 parent 64ad6b3
commit 1277cdb
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Showing 8 changed files with 179 additions and 132 deletions.
diff --git a/bpf/bpf.go b/bpf/bpf.go
@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"github.com/mdlayher/netlink"
 	"strings"
 	"unsafe"
 
@@ -198,143 +199,39 @@ func (b *BPF) UpdateFlowPidMapValues(data map[*BpfFlowPidKeyT]BpfProcessMetaT) e
 	return nil
 }
 
-func (b *BPF) AttachCgroups(cgroupPath string) error {
-	if b.skipAttachCgroup {
-		return nil
-	}
-
-	lk, err := link.AttachCgroup(link.CgroupOptions{
-		Path:    cgroupPath,
-		Attach:  ebpf.AttachCGroupInetSockCreate,
-		Program: b.objs.CgroupSockCreate,
-	})
-	if err != nil {
-		return fmt.Errorf("attach cgroup/sock_create: %w", err)
-	}
-	b.links = append(b.links, lk)
-
-	lk, err = link.AttachCgroup(link.CgroupOptions{
-		Path:    cgroupPath,
-		Attach:  ebpf.AttachCgroupInetSockRelease,
-		Program: b.objs.CgroupSockRelease,
-	})
-	if err != nil {
-		return fmt.Errorf("attach cgroup/sock_release: %w", err)
-	}
-	b.links = append(b.links, lk)
-
-	return nil
-}
-
 func (b *BPF) AttachKprobes() error {
 	err := b.attachFentryOrKprobe("security_sk_classify_flow",
 		b.objs.FentrySecuritySkClassifyFlow, b.objs.KprobeSecuritySkClassifyFlow)
 	if err != nil {
 		return fmt.Errorf(": %w", err)
 	}
 
-	err = b.attachFentryOrKprobe("tcp_sendmsg",
-		b.objs.FentryTcpSendmsg, b.objs.KprobeTcpSendmsg)
-	if err != nil {
-		return fmt.Errorf(": %w", err)
-	}
-
-	err = b.attachFentryOrKprobe("udp_send_skb", b.objs.FentryUdpSendSkb, b.objs.KprobeUdpSendSkb)
-	if err != nil {
-		log.Infof("%+v", err)
-		if strings.Contains(err.Error(), "no such file or directory") {
-			err = b.attachFentryOrKprobe("udp_sendmsg", b.objs.FentryUdpSendmsg, b.objs.KprobeUdpSendmsg)
-			if err != nil {
-				return fmt.Errorf(": %w", err)
-			}
-		} else {
-			return fmt.Errorf(": %w", err)
-		}
-	}
-
-	err = b.attachFentryOrKprobe("nf_nat_packet",
-		b.objs.FentryNfNatPacket, b.objs.KprobeNfNatPacket)
-	if err != nil {
-		log.Infof("%+v", err)
-		if strings.Contains(err.Error(), "no such file or directory") {
-			log.Info("the kernel does not support netfilter based NAT feature, skip attach kprobe/nf_nat_packet")
-		} else {
-			return fmt.Errorf(": %w", err)
-		}
-	}
-
-	err = b.attachFentryOrKprobe("nf_nat_manip_pkt",
-		b.objs.FentryNfNatManipPkt, b.objs.KprobeNfNatManipPkt)
-	if err != nil {
-		log.Infof("%+v", err)
-		if strings.Contains(err.Error(), "no such file or directory") {
-			log.Info("the kernel does not support netfilter based NAT feature, skip attach kprobe/nf_nat_manip_pkt")
-		} else {
+	if b.skipAttachCgroup {
+		err = b.attachFentryOrKprobe("tcp_sendmsg",
+			b.objs.FentryTcpSendmsg, b.objs.KprobeTcpSendmsg)
+		if err != nil {
 			return fmt.Errorf(": %w", err)
 		}
-	}
-
-	return b.attachNetDevHooks()
-}
-
-func (b *BPF) attachNetDevHooks() error {
-	if !b.opts.hookNetDev {
-		return nil
-	}
-
-	err := b.attachFexitOrKprobe("register_netdevice",
-		nil, b.objs.KprobeRegisterNetdevice, b.objs.KretprobeRegisterNetdevice)
-	if err != nil {
-		return err
-	}
-
-	// TODO: refine
-	err = b.attachFexitOrKprobe("__dev_get_by_index",
-		nil, nil, b.objs.KretprobeDevGetByIndex)
-	if err != nil {
-		log.Infof("%+v", err)
-		if strings.Contains(err.Error(), "no such file or directory") {
-			err = b.attachFexitOrKprobe("dev_get_by_index",
-				nil, nil, b.objs.KretprobeDevGetByIndexLegacy)
-			if err != nil {
-				return err
-			}
-		} else {
-			return err
-		}
-	}
 
-	err = b.attachFentryOrKprobe("__dev_change_net_namespace",
-		nil, b.objs.KprobeDevChangeNetNamespace)
-	if err != nil {
-		log.Infof("%+v", err)
-		if strings.Contains(err.Error(), "no such file or directory") {
-			err = b.attachFentryOrKprobe("dev_change_net_namespace",
-				nil, b.objs.KprobeDevChangeNetNamespaceLegacy)
-			if err != nil {
-				return err
+		err = b.attachFentryOrKprobe("udp_send_skb", b.objs.FentryUdpSendSkb, b.objs.KprobeUdpSendSkb)
+		if err != nil {
+			log.Infof("%+v", err)
+			if isProbeNotSupportErr(err) {
+				err = b.attachFentryOrKprobe("udp_sendmsg", b.objs.FentryUdpSendmsg, b.objs.KprobeUdpSendmsg)
+				if err != nil {
+					return fmt.Errorf(": %w", err)
+				}
+			} else {
+				return fmt.Errorf(": %w", err)
 			}
-		} else {
-			return err
 		}
 	}
 
-	err = b.attachFexitOrKprobe("__dev_change_net_namespace",
-		nil, nil, b.objs.KretprobeDevChangeNetNamespace)
-	if err != nil {
-		log.Infof("%+v", err)
-		if strings.Contains(err.Error(), "no such file or directory") {
-			err = b.attachFexitOrKprobe("dev_change_net_namespace",
-				nil, nil, b.objs.KretprobeDevChangeNetNamespaceLegacy)
-			if err != nil {
-				return err
-			}
-		} else {
-			return err
-		}
+	if err := b.attachNatHooks(); err != nil {
+		return fmt.Errorf(": %w", err)
 	}
 
-	return nil
+	return b.attachNetDevHooks()
 }
 
 func (b *BPF) AttachTracepoints() error {
@@ -472,6 +369,10 @@ func attachTcHook(ifindex int, prog *ebpf.Program, ingress bool) (func(), error)
 			}
 		}
 	}
+	err = tcnl.SetOption(netlink.ExtendedAcknowledge, true)
+	if err != nil {
+		return closeFunc, fmt.Errorf("tc: set option ExtendedAcknowledge: %w", err)
+	}
 
 	var filter *tc.Object
 	fd := uint32(prog.FD())
@@ -544,6 +445,10 @@ func ensureTcQdisc(ifindex int) (func(), error) {
 			}
 		}
 	}
+	err = tcnl.SetOption(netlink.ExtendedAcknowledge, true)
+	if err != nil {
+		return closeFunc, fmt.Errorf("tc: set option ExtendedAcknowledge: %w", err)
+	}
 
 	qdisc := tc.Object{
 		Msg: tc.Msg{

diff --git a/bpf/cgroup.go b/bpf/cgroup.go
@@ -0,0 +1,41 @@
+package bpf
+
+import (
+	"fmt"
+	"github.com/cilium/ebpf"
+	"github.com/cilium/ebpf/link"
+	"github.com/mozillazg/ptcpdump/internal/log"
+)
+
+func (b *BPF) AttachCgroups(cgroupPath string) error {
+	if cgroupPath == "" {
+		b.skipAttachCgroup = true
+	}
+	if b.skipAttachCgroup {
+		return nil
+	}
+
+	log.Info("attaching cgroup/sock_create")
+	lk, err := link.AttachCgroup(link.CgroupOptions{
+		Path:    cgroupPath,
+		Attach:  ebpf.AttachCGroupInetSockCreate,
+		Program: b.objs.CgroupSockCreate,
+	})
+	if err != nil {
+		return fmt.Errorf("attach cgroup/sock_create: %w", err)
+	}
+	b.links = append(b.links, lk)
+
+	log.Info("attaching cgroup/sock_release")
+	lk, err = link.AttachCgroup(link.CgroupOptions{
+		Path:    cgroupPath,
+		Attach:  ebpf.AttachCgroupInetSockRelease,
+		Program: b.objs.CgroupSockRelease,
+	})
+	if err != nil {
+		return fmt.Errorf("attach cgroup/sock_release: %w", err)
+	}
+	b.links = append(b.links, lk)
+
+	return nil
+}
diff --git a/bpf/nat.go b/bpf/nat.go
@@ -0,0 +1,32 @@
+package bpf
+
+import (
+	"fmt"
+	"github.com/mozillazg/ptcpdump/internal/log"
+)
+
+func (b *BPF) attachNatHooks() error {
+	err := b.attachFentryOrKprobe("nf_nat_packet",
+		b.objs.FentryNfNatPacket, b.objs.KprobeNfNatPacket)
+	if err != nil {
+		log.Infof("%+v", err)
+		if isProbeNotSupportErr(err) {
+			log.Info("the kernel does not support netfilter based NAT feature, skip attach kprobe/nf_nat_packet")
+		} else {
+			return fmt.Errorf(": %w", err)
+		}
+	}
+
+	err = b.attachFentryOrKprobe("nf_nat_manip_pkt",
+		b.objs.FentryNfNatManipPkt, b.objs.KprobeNfNatManipPkt)
+	if err != nil {
+		log.Infof("%+v", err)
+		if isProbeNotSupportErr(err) {
+			log.Info("the kernel does not support netfilter based NAT feature, skip attach kprobe/nf_nat_manip_pkt")
+		} else {
+			return fmt.Errorf(": %w", err)
+		}
+	}
+
+	return nil
+}
diff --git a/bpf/net_dev.go b/bpf/net_dev.go
@@ -0,0 +1,65 @@
+package bpf
+
+import (
+	"github.com/mozillazg/ptcpdump/internal/log"
+)
+
+func (b *BPF) attachNetDevHooks() error {
+	if !b.opts.hookNetDev {
+		return nil
+	}
+
+	err := b.attachFexitOrKprobe("register_netdevice",
+		nil, b.objs.KprobeRegisterNetdevice, b.objs.KretprobeRegisterNetdevice)
+	if err != nil {
+		return err
+	}
+
+	// TODO: refine
+	err = b.attachFexitOrKprobe("__dev_get_by_index",
+		nil, nil, b.objs.KretprobeDevGetByIndex)
+	if err != nil {
+		log.Infof("%+v", err)
+		if isProbeNotSupportErr(err) {
+			err = b.attachFexitOrKprobe("dev_get_by_index",
+				nil, nil, b.objs.KretprobeDevGetByIndexLegacy)
+			if err != nil {
+				return err
+			}
+		} else {
+			return err
+		}
+	}
+
+	err = b.attachFentryOrKprobe("__dev_change_net_namespace",
+		nil, b.objs.KprobeDevChangeNetNamespace)
+	if err != nil {
+		log.Infof("%+v", err)
+		if isProbeNotSupportErr(err) {
+			err = b.attachFentryOrKprobe("dev_change_net_namespace",
+				nil, b.objs.KprobeDevChangeNetNamespaceLegacy)
+			if err != nil {
+				return err
+			}
+		} else {
+			return err
+		}
+	}
+
+	err = b.attachFexitOrKprobe("__dev_change_net_namespace",
+		nil, nil, b.objs.KretprobeDevChangeNetNamespace)
+	if err != nil {
+		log.Infof("%+v", err)
+		if isProbeNotSupportErr(err) {
+			err = b.attachFexitOrKprobe("dev_change_net_namespace",
+				nil, nil, b.objs.KretprobeDevChangeNetNamespaceLegacy)
+			if err != nil {
+				return err
+			}
+		} else {
+			return err
+		}
+	}
+
+	return nil
+}
diff --git a/bpf/utils.go b/bpf/utils.go
@@ -5,6 +5,7 @@ import (
 	"github.com/cilium/ebpf"
 	"github.com/cilium/ebpf/link"
 	"github.com/mozillazg/ptcpdump/internal/log"
+	"strings"
 )
 
 func (b *BPF) attachFentryOrKprobe(symbol string, fentryProg *ebpf.Program, kprobeProg *ebpf.Program) error {
@@ -101,3 +102,14 @@ func (b *BPF) attachBTFTracepointOrRawTP(name string, btfProg *ebpf.Program, raw
 
 	return nil
 }
+
+func isProbeNotSupportErr(err error) bool {
+	// TODO: refine
+	if strings.Contains(err.Error(), "no such file or directory") ||
+		strings.Contains(err.Error(), "invalid argument") {
+		log.Infof("%T", err)
+		log.Infof("%#v", err)
+		return true
+	}
+	return false
+}
diff --git a/go.mod b/go.mod
@@ -22,6 +22,7 @@ require (
 	github.com/containerd/errdefs v0.3.0
 	github.com/go-logr/logr v1.4.2
 	github.com/mandiant/GoReSym v1.7.2-0.20240819162932-534ca84b42d5
+	github.com/mdlayher/netlink v1.7.2
 	github.com/smira/go-xz v0.1.0
 	github.com/stretchr/testify v1.9.0
 	github.com/vishvananda/netns v0.0.5
@@ -61,7 +62,6 @@ require (
 	github.com/josharian/native v1.1.0 // indirect
 	github.com/klauspost/compress v1.16.7 // indirect
 	github.com/lufia/plan9stats v0.0.0-20211012122336-39d0f177ccd0 // indirect
-	github.com/mdlayher/netlink v1.7.2 // indirect
 	github.com/mdlayher/socket v0.4.1 // indirect
 	github.com/moby/docker-image-spec v1.3.1 // indirect
 	github.com/moby/locker v1.0.1 // indirect

diff --git a/internal/capturer/capturer.go b/internal/capturer/capturer.go
@@ -181,10 +181,8 @@ func (c *Capturer) AttachTracingHooks() error {
 	if err != nil {
 		log.Warnf("skip attach cgroup due to get cgroup v2 root dir failed: %s", err)
 	}
-	if cgroupPath != "" {
-		if err := bf.AttachCgroups(cgroupPath); err != nil {
-			return err
-		}
+	if err := bf.AttachCgroups(cgroupPath); err != nil {
+		return err
 	}
 
 	if err := bf.AttachKprobes(); err != nil {

diff --git a/internal/utils/cgroup.go b/internal/utils/cgroup.go
@@ -16,12 +16,6 @@ var reCgroup2Mount = regexp.MustCompile(`(?m)^cgroup2\s(/\S+)\scgroup2\s`)
 
 func GetCgroupV2RootDir() (string, error) {
 	p, err := getCgroupV2RootDir(pathProcMounts)
-	if err != nil {
-		st, errv2 := os.Stat(defaultCgroupV2RootDir)
-		if errv2 == nil && st.IsDir() {
-			return defaultCgroupV2RootDir, nil
-		}
-	}
 	return p, err
 }