Add UT for VXLANFDB.

felix/netlinkshim/mocknetlink/netlink.go

@@ -305,7 +305,8 @@ type MockNetlinkDataplane struct {
 }
 
 type NeighKey struct {
-	MAC string
+	LinkIndex int
+	MAC       string
 	IP  ip.Addr
 }
 
@@ -485,6 +486,7 @@ func (d *MockNetlinkDataplane) LinkByName(name string) (netlink.Link, error) {
 	if d.DeleteInterfaceAfterLinkByName {
 		defer delete(d.NameToLink, name)
 	}
+	log.Debugf("Looking for interface: %s", name)
 	if link, ok := d.NameToLink[name]; ok {
 		return link.copy(), nil
 	}
@@ -880,6 +882,27 @@ func (d *MockNetlinkDataplane) RouteDel(route *netlink.Route) error {
 	}
 }
 
+// AddNeighs allows test code to add neighbours to the mock dataplane
+// without going through the netlink API.
+func (d *MockNetlinkDataplane) AddNeighs(family int, neighs ...netlink.Neigh) {
+	err := d.checkNeighFamily(family)
+	if err != nil {
+		panic(err)
+	}
+	if d.NeighsByFamily[family] == nil {
+		d.NeighsByFamily[family] = map[NeighKey]*netlink.Neigh{}
+	}
+	for _, neigh := range neighs {
+		neigh := neigh
+		nk := NeighKey{
+			LinkIndex: neigh.LinkIndex,
+			MAC:       neigh.HardwareAddr.String(),
+			IP:        ip.FromNetIP(neigh.IP),
+		}
+		d.NeighsByFamily[family][nk] = &neigh
+	}
+}
+
 func (d *MockNetlinkDataplane) NeighAdd(neigh *netlink.Neigh) error {
 	family := neigh.Family
 	err := d.checkNeighFamily(family)
@@ -896,7 +919,11 @@ func (d *MockNetlinkDataplane) NeighAdd(neigh *netlink.Neigh) error {
 	if neigh.HardwareAddr == nil {
 		return unix.EINVAL
 	}
+	if neigh.LinkIndex == 0 {
+		return unix.EINVAL
+	}
 	nk := NeighKey{
+		LinkIndex: neigh.LinkIndex,
 		MAC: neigh.HardwareAddr.String(),
 		IP:  ip.FromNetIP(neigh.IP),
 	}
@@ -951,7 +978,11 @@ func (d *MockNetlinkDataplane) NeighSet(neigh *netlink.Neigh) error {
 	if neigh.HardwareAddr == nil {
 		return unix.EINVAL
 	}
+	if neigh.LinkIndex == 0 {
+		return unix.EINVAL
+	}
 	nk := NeighKey{
+		LinkIndex: neigh.LinkIndex,
 		MAC: neigh.HardwareAddr.String(),
 		IP:  ip.FromNetIP(neigh.IP),
 	}
@@ -976,7 +1007,11 @@ func (d *MockNetlinkDataplane) NeighDel(neigh *netlink.Neigh) error {
 	if neigh.HardwareAddr == nil {
 		return unix.EINVAL
 	}
+	if neigh.LinkIndex == 0 {
+		return unix.EINVAL
+	}
 	nk := NeighKey{
+		LinkIndex: neigh.LinkIndex,
 		MAC: neigh.HardwareAddr.String(),
 		IP:  ip.FromNetIP(neigh.IP),
 	}
@@ -1011,8 +1046,9 @@ func (d *MockNetlinkDataplane) AddStaticArpEntry(cidr ip.CIDR, destMAC net.Hardw
 
 	linkIndex := d.NameToLink[ifaceName].LinkAttrs.Index
 	d.NeighsByFamily[unix.AF_INET][NeighKey{
-		MAC: destMAC.String(),
-		IP:  cidr.Addr(),
+		LinkIndex: linkIndex,
+		MAC:       destMAC.String(),
+		IP:        cidr.Addr(),
 	}] = &netlink.Neigh{
 		Family:       unix.AF_INET,
 		LinkIndex:    linkIndex,

felix/vxlanfdb/vxlan_fdb.go

@@ -44,23 +44,39 @@ type VTEP struct {
 }
 
 type VXLANFDB struct {
-	ifaceName      string
-	ifIndex        int
-	arpEntries     *deltatracker.DeltaTracker[string, ipMACMapping]
-	fdbEntries     *deltatracker.DeltaTracker[string, ipMACMapping]
-	logCxt         *log.Entry
-	resyncPending  bool
-	logNextSuccess bool
-	nl             *handlemgr.HandleManager
-	family         int
+	ifaceName        string
+	ifIndex          int
+	arpEntries       *deltatracker.DeltaTracker[string, ipMACMapping]
+	fdbEntries       *deltatracker.DeltaTracker[string, ipMACMapping]
+	logCxt           *log.Entry
+	resyncPending    bool
+	logNextSuccess   bool
+	nl               *handlemgr.HandleManager
+	family           int
+
+	newNetlinkHandle func() (netlinkshim.Interface, error)
 }
 
 type ipMACMapping struct {
 	IP  ip.Addr
 	MAC net.HardwareAddr
 }
 
-func New(family int, ifaceName string, featureDetector environment.FeatureDetectorIface, netlinkTimeout time.Duration) *VXLANFDB {
+type VXLANFDBOption func(*VXLANFDB)
+
+func WithNetlinkHandleShim(newNetlinkHandle func() (netlinkshim.Interface, error)) VXLANFDBOption {
+	return func(fdb *VXLANFDB) {
+		fdb.newNetlinkHandle = newNetlinkHandle
+	}
+}
+
+func New(
+	family int,
+	ifaceName string,
+	featureDetector environment.FeatureDetectorIface,
+	netlinkTimeout time.Duration,
+	opts ...VXLANFDBOption,
+) *VXLANFDB {
 	switch family {
 	case unix.AF_INET, unix.AF_INET6:
 	default:
@@ -77,14 +93,21 @@ func New(family int, ifaceName string, featureDetector environment.FeatureDetect
 		}),
 		resyncPending:  true,
 		logNextSuccess: true,
-		nl: handlemgr.NewHandleManager(
-			featureDetector,
-			handlemgr.WithSocketTimeout(netlinkTimeout),
-			// The Netlink library doesn't seem to be able to list
-			// both types of neighbors in strict mode.
-			handlemgr.WithStrictModeOverride(false),
-		),
+		newNetlinkHandle: netlinkshim.NewRealNetlink,
+	}
+
+	for _, o := range opts {
+		o(&f)
 	}
+
+	f.nl = handlemgr.NewHandleManager(
+		featureDetector,
+		handlemgr.WithSocketTimeout(netlinkTimeout),
+		// The Netlink library doesn't seem to be able to list
+		// both types of neighbors in strict mode.
+		handlemgr.WithStrictModeOverride(false),
+		handlemgr.WithNewHandleOverride(f.newNetlinkHandle),
+	)
 	return &f
 }
 
@@ -287,7 +310,7 @@ func (r *VXLANFDB) resync(nl netlinkshim.Interface) error {
 	}
 	r.ifIndex = link.Attrs().Index
 
-	// Refresh the neighbours.
+	// Refresh the neighbors.
 	existingNeigh, err := nl.NeighList(r.ifIndex, unix.AF_INET)
 	if err != nil {
 		r.logCxt.WithError(err).Error("Failed to list neighbors")