API interface change and UTs for TC functions (#25)

* UTs for tc functions

* Fix vet

* Add mocks

* Feedback

* PR feedbacl

.github/workflows/pr-tests.yaml

@@ -33,6 +33,6 @@ jobs:
       - name: Build
         run: make build-linux
       - name: Unit test
-        run: make unit-test
+        run: sudo make unit-test
       - name: Upload code coverage
         uses: codecov/codecov-action@v3

pkg/tc/generate_mocks.go

@@ -0,0 +1,15 @@
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+package tc
+
+//go:generate go run github.com/golang/mock/mockgen -destination mocks/tc_mocks.go . BpfTc

pkg/tc/tc.go

@@ -31,6 +31,28 @@ const (
 
 var log = logger.Get()
 
+type BpfTc interface {
+	TCIngressAttach(interfaceName string, progFD int, funcName string) error
+	TCIngressDetach(interfaceName string) error
+	TCEgressAttach(interfaceName string, progFD int, funcName string) error
+	TCEgressDetach(interfaceName string) error
+	CleanupQdiscs(ingressCleanup bool, egressCleanup bool) error
+	mismatchedInterfacePrefix(interfaceName string) error
+}
+
+var _ BpfTc = &bpfTc{}
+
+type bpfTc struct {
+	InterfacePrefix string
+}
+
+func New(interfacePrefix string) BpfTc {
+	return &bpfTc{
+		InterfacePrefix: interfacePrefix,
+	}
+
+}
+
 func enableQdisc(link netlink.Link) bool {
 	qdiscs, err := netlink.QdiscList(link)
 	if err != nil {
@@ -54,7 +76,20 @@ func enableQdisc(link netlink.Link) bool {
 
 }
 
-func TCIngressAttach(interfaceName string, progFD int, funcName string) error {
+func (m *bpfTc) mismatchedInterfacePrefix(interfaceName string) error {
+	if !strings.HasPrefix(interfaceName, m.InterfacePrefix) {
+		log.Errorf("expected prefix - %s but got %s", m.InterfacePrefix, interfaceName)
+		return errors.New("Mismatched initialized prefix name and passed interface name")
+	}
+	return nil
+}
+
+func (m *bpfTc) TCIngressAttach(interfaceName string, progFD int, funcName string) error {
+
+	if err := m.mismatchedInterfacePrefix(interfaceName); err != nil {
+		return err
+	}
+
 	intf, err := netlink.LinkByName(interfaceName)
 	if err != nil {
 		log.Errorf("failed to find device by name %s: %w", interfaceName, err)
@@ -101,7 +136,12 @@ func TCIngressAttach(interfaceName string, progFD int, funcName string) error {
 	return nil
 }
 
-func TCIngressDetach(interfaceName string) error {
+func (m *bpfTc) TCIngressDetach(interfaceName string) error {
+
+	if err := m.mismatchedInterfacePrefix(interfaceName); err != nil {
+		return err
+	}
+
 	intf, err := netlink.LinkByName(interfaceName)
 	if err != nil {
 		log.Errorf("failed to find device by name %s: %w", interfaceName, err)
@@ -132,7 +172,12 @@ func TCIngressDetach(interfaceName string) error {
 	return fmt.Errorf("no active filter to detach-%s", interfaceName)
 }
 
-func TCEgressAttach(interfaceName string, progFD int, funcName string) error {
+func (m *bpfTc) TCEgressAttach(interfaceName string, progFD int, funcName string) error {
+
+	if err := m.mismatchedInterfacePrefix(interfaceName); err != nil {
+		return err
+	}
+
 	intf, err := netlink.LinkByName(interfaceName)
 	if err != nil {
 		log.Errorf("failed to find device by name %s: %w", interfaceName, err)
@@ -179,7 +224,12 @@ func TCEgressAttach(interfaceName string, progFD int, funcName string) error {
 	return nil
 }
 
-func TCEgressDetach(interfaceName string) error {
+func (m *bpfTc) TCEgressDetach(interfaceName string) error {
+
+	if err := m.mismatchedInterfacePrefix(interfaceName); err != nil {
+		return err
+	}
+
 	intf, err := netlink.LinkByName(interfaceName)
 	if err != nil {
 		log.Errorf("failed to find device by name %s: %w", interfaceName, err)
@@ -210,9 +260,9 @@ func TCEgressDetach(interfaceName string) error {
 	return fmt.Errorf("no active filter to detach-%s", interfaceName)
 }
 
-func CleanupQdiscs(prefix string, ingressCleanup bool, egressCleanup bool) error {
+func (m *bpfTc) CleanupQdiscs(ingressCleanup bool, egressCleanup bool) error {
 
-	if prefix == "" {
+	if m.InterfacePrefix == "" {
 		log.Errorf("invalid empty prefix")
 		return nil
 	}
@@ -225,10 +275,10 @@ func CleanupQdiscs(prefix string, ingressCleanup bool, egressCleanup bool) error
 
 	for _, link := range linkList {
 		linkName := link.Attrs().Name
-		if strings.HasPrefix(linkName, prefix) {
+		if strings.HasPrefix(linkName, m.InterfacePrefix) {
 			if ingressCleanup {
 				log.Infof("Trying to cleanup ingress on %s", linkName)
-				err = TCIngressDetach(linkName)
+				err = m.TCIngressDetach(linkName)
 				if err != nil {
 					if err.Error() == FILTER_CLEANUP_FAILED {
 						log.Errorf("failed to detach ingress, might not be present so moving on")
@@ -238,7 +288,7 @@ func CleanupQdiscs(prefix string, ingressCleanup bool, egressCleanup bool) error
 
 			if egressCleanup {
 				log.Infof("Trying to cleanup egress on %s", linkName)
-				err = TCEgressDetach(linkName)
+				err = m.TCEgressDetach(linkName)
 				if err != nil {
 					if err.Error() == FILTER_CLEANUP_FAILED {
 						log.Errorf("failed to detach egress, might not be present so moving on")