Program MTU on vxlan routes

felix/dataplane/linux/int_dataplane.go

@@ -668,6 +668,7 @@ func NewIntDataplaneDriver(config Config) *InternalDataplane {
 			config,
 			dp.loopSummarizer,
 			4,
+			config.VXLANMTU,
 		)
 		dp.vxlanParentC = make(chan string, 1)
 		go dp.vxlanManager.KeepVXLANDeviceInSync(context.Background(), config.VXLANMTU, dataplaneFeatures.ChecksumOffloadBroken, 10*time.Second, dp.vxlanParentC)
@@ -1130,6 +1131,7 @@ func NewIntDataplaneDriver(config Config) *InternalDataplane {
 				config,
 				dp.loopSummarizer,
 				6,
+				config.VXLANMTUV6,
 			)
 			dp.vxlanParentCV6 = make(chan string, 1)
 			go dp.vxlanManagerV6.KeepVXLANDeviceInSync(context.Background(), config.VXLANMTUV6, dataplaneFeatures.ChecksumOffloadBroken, 10*time.Second, dp.vxlanParentCV6)

felix/dataplane/linux/vxlan_mgr.go

@@ -76,6 +76,7 @@ type vxlanManager struct {
 	vxlanID     int
 	vxlanPort   int
 	ipVersion   uint8
+	mtu         int
 
 	// Indicates if configuration has changed since the last apply.
 	routesDirty       bool
@@ -104,6 +105,7 @@ func newVXLANManager(
 	dpConfig Config,
 	opRecorder logutils.OpRecorder,
 	ipVersion uint8,
+	mtu int,
 ) *vxlanManager {
 	nlHandle, _ := netlinkshim.NewRealNetlink()
 	return newVXLANManagerWithShims(
@@ -115,6 +117,7 @@ func newVXLANManager(
 		opRecorder,
 		nlHandle,
 		ipVersion,
+		mtu,
 	)
 }
 
@@ -127,6 +130,7 @@ func newVXLANManagerWithShims(
 	opRecorder logutils.OpRecorder,
 	nlHandle netlinkHandle,
 	ipVersion uint8,
+	mtu int,
 ) *vxlanManager {
 	logCtx := logrus.WithField("ipVersion", ipVersion)
 	return &vxlanManager{
@@ -147,6 +151,7 @@ func newVXLANManagerWithShims(
 		vxlanID:           dpConfig.RulesConfig.VXLANVNI,
 		vxlanPort:         dpConfig.RulesConfig.VXLANPort,
 		ipVersion:         ipVersion,
+		mtu:               mtu,
 		externalNodeCIDRs: dpConfig.ExternalNodesCidrs,
 		routesDirty:       true,
 		vtepsDirty:        true,
@@ -531,7 +536,10 @@ func (m *vxlanManager) tunneledRoute(cidr ip.CIDR, r *proto.RouteUpdate) *routet
 	if isRemoteTunnelRoute(r) {
 		// We treat remote tunnel routes as directly connected. They don't have a gateway of
 		// the VTEP because they ARE the VTEP!
-		return &routetable.Target{CIDR: cidr}
+		return &routetable.Target{
+			CIDR: cidr,
+			MTU:  m.mtu,
+		}
 	}
 
 	// Extract the gateway addr for this route based on its remote VTEP.
@@ -548,6 +556,7 @@ func (m *vxlanManager) tunneledRoute(cidr ip.CIDR, r *proto.RouteUpdate) *routet
 		Type: routetable.TargetTypeVXLAN,
 		CIDR: cidr,
 		GW:   ip.FromString(vtepAddr),
+		MTU:  m.mtu,
 	}
 }
 

felix/dataplane/linux/vxlan_mgr_test.go

@@ -157,6 +157,7 @@ var _ = Describe("VXLANManager", func() {
 				ipVersion: 4,
 			},
 			4,
+			4444,
 		)
 
 		managerV6 = newVXLANManagerWithShims(
@@ -179,6 +180,7 @@ var _ = Describe("VXLANManager", func() {
 				ipVersion: 6,
 			},
 			6,
+			6666,
 		)
 	})
 
@@ -478,7 +480,11 @@ var _ = Describe("VXLANManager", func() {
 
 		// Expect a directly connected route to the borrowed IP.
 		Expect(rt.currentRoutes[dataplanedefs.VXLANIfaceNameV4]).To(HaveLen(1))
-		Expect(rt.currentRoutes[dataplanedefs.VXLANIfaceNameV4][0]).To(Equal(routetable.Target{CIDR: ip.MustParseCIDROrIP("10.0.1.1/32")}))
+		Expect(rt.currentRoutes[dataplanedefs.VXLANIfaceNameV4][0]).To(Equal(
+			routetable.Target{
+				CIDR: ip.MustParseCIDROrIP("10.0.1.1/32"),
+				MTU:  4444,
+			}))
 
 		// Delete the route.
 		manager.OnUpdate(&proto.RouteRemove{
@@ -508,7 +514,11 @@ var _ = Describe("VXLANManager", func() {
 
 		// Expect a directly connected route to the borrowed IP.
 		Expect(rt.currentRoutes[dataplanedefs.VXLANIfaceNameV6]).To(HaveLen(1))
-		Expect(rt.currentRoutes[dataplanedefs.VXLANIfaceNameV6][0]).To(Equal(routetable.Target{CIDR: ip.MustParseCIDROrIP("fc00:10:244::1/112")}))
+		Expect(rt.currentRoutes[dataplanedefs.VXLANIfaceNameV6][0]).To(Equal(
+			routetable.Target{
+				CIDR: ip.MustParseCIDROrIP("fc00:10:244::1/112"),
+				MTU:  6666,
+			}))
 
 		// Delete the route.
 		managerV6.OnUpdate(&proto.RouteRemove{

felix/routetable/defs.go

@@ -73,6 +73,7 @@ type Target struct {
 	DestMAC   net.HardwareAddr
 	Protocol  netlink.RouteProtocol
 	MultiPath []NextHop
+	MTU       int
 }
 
 func (t Target) Equal(t2 Target) bool {

felix/routetable/route_table.go

@@ -749,6 +749,7 @@ func (r *RouteTable) recalculateDesiredKernelRoute(cidr ip.CIDR) {
 	} else {
 		kernRoute.GW = bestTarget.GW
 		kernRoute.Ifindex = bestIfaceIdx
+		kernRoute.MTU = bestTarget.MTU
 	}
 	if log.IsLevelEnabled(log.DebugLevel) && !reflect.DeepEqual(oldDesiredRoute, kernRoute) {
 		r.logCxt.WithFields(log.Fields{
@@ -1285,6 +1286,7 @@ func (r *RouteTable) netlinkRouteToKernelRoute(route *netlink.Route) (kernKey ke
 		Src:      ip.FromNetIP(route.Src),
 		OnLink:   route.Flags&unix.RTNH_F_ONLINK != 0,
 		Protocol: route.Protocol,
+		MTU:      route.MTU,
 	}
 
 	if len(route.MultiPath) > 0 {
@@ -1421,6 +1423,7 @@ func (r *RouteTable) applyUpdates(attempt int) error {
 			LinkIndex: kRoute.Ifindex,
 			Protocol:  kRoute.Protocol,
 			Flags:     flags,
+			MTU:       kRoute.MTU,
 		}
 		for _, nh := range kRoute.NextHops {
 			nlRoute.MultiPath = append(nlRoute.MultiPath, &netlink.NexthopInfo{
@@ -1754,6 +1757,7 @@ type kernelRoute struct {
 	// NextHops should be specified (for a multi-path route).
 	GW      ip.Addr
 	Ifindex int
+	MTU     int
 
 	NextHops []kernelNextHop
 }
@@ -1785,6 +1789,9 @@ func (r kernelRoute) Equals(b kernelRoute) bool {
 	if r.Ifindex != b.Ifindex {
 		return false
 	}
+	if r.MTU != b.MTU {
+		return false
+	}
 	if len(r.NextHops) != len(b.NextHops) {
 		return false
 	}
@@ -1833,8 +1840,16 @@ func (r kernelRoute) String() string {
 		nextHopPart = fmt.Sprintf("GW=%s, Ifindex=%d", gwStr, r.Ifindex)
 	}
 
-	return fmt.Sprintf("kernelRoute{Type=%d, Scope=%d, Src=%s, Protocol=%v, OnLink=%v, %s}",
+	str := fmt.Sprintf("kernelRoute{Type=%d, Scope=%d, Src=%s, Protocol=%v, OnLink=%v, %s",
 		r.Type, r.Scope, srcStr, r.Protocol, r.OnLink, nextHopPart)
+
+	if r.MTU != 0 {
+		str += fmt.Sprintf(", mtu %d", r.MTU)
+	}
+
+	str += "}"
+
+	return str
 }
 
 type kernelNextHop struct {