Rename DefaultRouter event to OffLinkRoute event

This change prepares for a later change which supports the NDP
Route Information option to discover more-specific routes, as
per RFC 4191.

Updates #6172.

PiperOrigin-RevId: 379361330

1 files changed, 88 insertions, 85 deletions

diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go
index b5878904b..b5c6626d6 100644
--- a/pkg/tcpip/stack/ndp_test.go
+++ b/pkg/tcpip/stack/ndp_test.go
@@ -112,11 +112,12 @@ type ndpDADEvent struct {
 	res   stack.DADResult
 }
 
-type ndpRouterEvent struct {
-	nicID tcpip.NICID
-	addr  tcpip.Address
-	// true if router was discovered, false if invalidated.
-	discovered bool
+type ndpOffLinkRouteEvent struct {
+	nicID  tcpip.NICID
+	subnet tcpip.Subnet
+	router tcpip.Address
+	// true if route was updated, false if invalidated.
+	updated bool
 }
 
 type ndpPrefixEvent struct {
@@ -167,7 +168,7 @@ var _ ipv6.NDPDispatcher = (*ndpDispatcher)(nil)
 // related events happen for test purposes.
 type ndpDispatcher struct {
 	dadC                 chan ndpDADEvent
-	routerC              chan ndpRouterEvent
+	offLinkRouteC        chan ndpOffLinkRouteEvent
 	prefixC              chan ndpPrefixEvent
 	autoGenAddrC         chan ndpAutoGenAddrEvent
 	rdnssC               chan ndpRDNSSEvent
@@ -187,23 +188,25 @@ func (n *ndpDispatcher) OnDuplicateAddressDetectionResult(nicID tcpip.NICID, add
 	}
 }
 
-// Implements ipv6.NDPDispatcher.OnDefaultRouterDiscovered.
-func (n *ndpDispatcher) OnDefaultRouterDiscovered(nicID tcpip.NICID, addr tcpip.Address) {
-	if c := n.routerC; c != nil {
-		c <- ndpRouterEvent{
+// Implements ipv6.NDPDispatcher.OnOffLinkRouteUpdated.
+func (n *ndpDispatcher) OnOffLinkRouteUpdated(nicID tcpip.NICID, subnet tcpip.Subnet, router tcpip.Address) {
+	if c := n.offLinkRouteC; c != nil {
+		c <- ndpOffLinkRouteEvent{
 			nicID,
-			addr,
+			subnet,
+			router,
 			true,
 		}
 	}
 }
 
-// Implements ipv6.NDPDispatcher.OnDefaultRouterInvalidated.
-func (n *ndpDispatcher) OnDefaultRouterInvalidated(nicID tcpip.NICID, addr tcpip.Address) {
-	if c := n.routerC; c != nil {
-		c <- ndpRouterEvent{
+// Implements ipv6.NDPDispatcher.OnOffLinkRouteInvalidated.
+func (n *ndpDispatcher) OnOffLinkRouteInvalidated(nicID tcpip.NICID, subnet tcpip.Subnet, router tcpip.Address) {
+	if c := n.offLinkRouteC; c != nil {
+		c <- ndpOffLinkRouteEvent{
 			nicID,
-			addr,
+			subnet,
+			router,
 			false,
 		}
 	}
@@ -1198,9 +1201,9 @@ func TestDynamicConfigurationsDisabled(t *testing.T) {
 
 				t.Run(fmt.Sprintf("HandleRAs(%s), Forwarding(%t), Enabled(%t)", handle, forwarding, enable), func(t *testing.T) {
 					ndpDisp := ndpDispatcher{
-						routerC:      make(chan ndpRouterEvent, 1),
-						prefixC:      make(chan ndpPrefixEvent, 1),
-						autoGenAddrC: make(chan ndpAutoGenAddrEvent, 1),
+						offLinkRouteC: make(chan ndpOffLinkRouteEvent, 1),
+						prefixC:       make(chan ndpPrefixEvent, 1),
+						autoGenAddrC:  make(chan ndpAutoGenAddrEvent, 1),
 					}
 					ndpConfigs := test.config(enable)
 					ndpConfigs.HandleRAs = handle
@@ -1270,8 +1273,8 @@ func TestDynamicConfigurationsDisabled(t *testing.T) {
 						t.Errorf("got v6Stats.UnhandledRouterAdvertisements.Value() = %d, want = %d", got, want)
 					}
 					select {
-					case e := <-ndpDisp.routerC:
-						t.Errorf("unexpectedly discovered a router when configured not to: %#v", e)
+					case e := <-ndpDisp.offLinkRouteC:
+						t.Errorf("unexpectedly updated an off-link route when configured not to: %#v", e)
 					default:
 					}
 					select {
@@ -1298,9 +1301,9 @@ func boolToUint64(v bool) uint64 {
 }
 
 // Check e to make sure that the event is for addr on nic with ID 1, and the
-// discovered flag set to discovered.
-func checkRouterEvent(e ndpRouterEvent, addr tcpip.Address, discovered bool) string {
-	return cmp.Diff(ndpRouterEvent{nicID: 1, addr: addr, discovered: discovered}, e, cmp.AllowUnexported(e))
+// update flag set to updated.
+func checkOffLinkRouteEvent(e ndpOffLinkRouteEvent, router tcpip.Address, updated bool) string {
+	return cmp.Diff(ndpOffLinkRouteEvent{nicID: 1, subnet: header.IPv6EmptySubnet, router: router, updated: updated}, e, cmp.AllowUnexported(e))
 }
 
 func testWithRAs(t *testing.T, f func(*testing.T, ipv6.HandleRAsConfiguration, bool)) {
@@ -1336,7 +1339,7 @@ func testWithRAs(t *testing.T, f func(*testing.T, ipv6.HandleRAsConfiguration, b
 func TestRouterDiscovery(t *testing.T) {
 	testWithRAs(t, func(t *testing.T, handleRAs ipv6.HandleRAsConfiguration, forwarding bool) {
 		ndpDisp := ndpDispatcher{
-			routerC: make(chan ndpRouterEvent, 1),
+			offLinkRouteC: make(chan ndpOffLinkRouteEvent, 1),
 		}
 		e := channel.New(0, 1280, linkAddr1)
 		clock := faketime.NewManualClock()
@@ -1351,27 +1354,27 @@ func TestRouterDiscovery(t *testing.T) {
 			Clock: clock,
 		})
 
-		expectRouterEvent := func(addr tcpip.Address, discovered bool) {
+		expectOffLinkRouteEvent := func(addr tcpip.Address, updated bool) {
 			t.Helper()
 
 			select {
-			case e := <-ndpDisp.routerC:
-				if diff := checkRouterEvent(e, addr, discovered); diff != "" {
-					t.Errorf("router event mismatch (-want +got):\n%s", diff)
+			case e := <-ndpDisp.offLinkRouteC:
+				if diff := checkOffLinkRouteEvent(e, addr, updated); diff != "" {
+					t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
 				}
 			default:
 				t.Fatal("expected router discovery event")
 			}
 		}
 
-		expectAsyncRouterInvalidationEvent := func(addr tcpip.Address, timeout time.Duration) {
+		expectAsyncOffLinkRouteInvalidationEvent := func(addr tcpip.Address, timeout time.Duration) {
 			t.Helper()
 
 			clock.Advance(timeout)
 			select {
-			case e := <-ndpDisp.routerC:
-				if diff := checkRouterEvent(e, addr, false); diff != "" {
-					t.Errorf("router event mismatch (-want +got):\n%s", diff)
+			case e := <-ndpDisp.offLinkRouteC:
+				if diff := checkOffLinkRouteEvent(e, addr, false); diff != "" {
+					t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
 				}
 			default:
 				t.Fatal("timed out waiting for router discovery event")
@@ -1390,26 +1393,26 @@ func TestRouterDiscovery(t *testing.T) {
 		// remembered.
 		e.InjectInbound(header.IPv6ProtocolNumber, raBuf(llAddr2, 0))
 		select {
-		case <-ndpDisp.routerC:
-			t.Fatal("unexpectedly discovered a router with 0 lifetime")
+		case <-ndpDisp.offLinkRouteC:
+			t.Fatal("unexpectedly updated an off-link route with 0 lifetime")
 		default:
 		}
 
 		// Rx an RA from lladdr2 with a huge lifetime.
 		e.InjectInbound(header.IPv6ProtocolNumber, raBuf(llAddr2, 1000))
-		expectRouterEvent(llAddr2, true)
+		expectOffLinkRouteEvent(llAddr2, true)
 
 		// Rx an RA from another router (lladdr3) with non-zero lifetime.
 		const l3LifetimeSeconds = 6
 		e.InjectInbound(header.IPv6ProtocolNumber, raBuf(llAddr3, l3LifetimeSeconds))
-		expectRouterEvent(llAddr3, true)
+		expectOffLinkRouteEvent(llAddr3, true)
 
 		// Rx an RA from lladdr2 with lesser lifetime.
 		const l2LifetimeSeconds = 2
 		e.InjectInbound(header.IPv6ProtocolNumber, raBuf(llAddr2, l2LifetimeSeconds))
 		select {
-		case <-ndpDisp.routerC:
-			t.Fatal("Should not receive a router event when updating lifetimes for known routers")
+		case <-ndpDisp.offLinkRouteC:
+			t.Fatal("should not receive a off-link route event when updating lifetimes for known routers")
 		default:
 		}
 
@@ -1420,15 +1423,15 @@ func TestRouterDiscovery(t *testing.T) {
 		// Wait for the normal lifetime plus an extra bit for the
 		// router to get invalidated. If we don't get an invalidation
 		// event after this time, then something is wrong.
-		expectAsyncRouterInvalidationEvent(llAddr2, l2LifetimeSeconds*time.Second)
+		expectAsyncOffLinkRouteInvalidationEvent(llAddr2, l2LifetimeSeconds*time.Second)
 
 		// Rx an RA from lladdr2 with huge lifetime.
 		e.InjectInbound(header.IPv6ProtocolNumber, raBuf(llAddr2, 1000))
-		expectRouterEvent(llAddr2, true)
+		expectOffLinkRouteEvent(llAddr2, true)
 
 		// Rx an RA from lladdr2 with zero lifetime. It should be invalidated.
 		e.InjectInbound(header.IPv6ProtocolNumber, raBuf(llAddr2, 0))
-		expectRouterEvent(llAddr2, false)
+		expectOffLinkRouteEvent(llAddr2, false)
 
 		// Wait for lladdr3's router invalidation job to execute. The lifetime
 		// of the router should have been updated to the most recent (smaller)
@@ -1437,7 +1440,7 @@ func TestRouterDiscovery(t *testing.T) {
 		// Wait for the normal lifetime plus an extra bit for the
 		// router to get invalidated. If we don't get an invalidation
 		// event after this time, then something is wrong.
-		expectAsyncRouterInvalidationEvent(llAddr3, l3LifetimeSeconds*time.Second)
+		expectAsyncOffLinkRouteInvalidationEvent(llAddr3, l3LifetimeSeconds*time.Second)
 	})
 }
 
@@ -1445,7 +1448,7 @@ func TestRouterDiscovery(t *testing.T) {
 // ipv6.MaxDiscoveredDefaultRouters discovered routers are remembered.
 func TestRouterDiscoveryMaxRouters(t *testing.T) {
 	ndpDisp := ndpDispatcher{
-		routerC: make(chan ndpRouterEvent, 1),
+		offLinkRouteC: make(chan ndpOffLinkRouteEvent, 1),
 	}
 	e := channel.New(0, 1280, linkAddr1)
 	s := stack.New(stack.Options{
@@ -1472,9 +1475,9 @@ func TestRouterDiscoveryMaxRouters(t *testing.T) {
 
 		if i <= ipv6.MaxDiscoveredDefaultRouters {
 			select {
-			case e := <-ndpDisp.routerC:
-				if diff := checkRouterEvent(e, llAddr, true); diff != "" {
-					t.Errorf("router event mismatch (-want +got):\n%s", diff)
+			case e := <-ndpDisp.offLinkRouteC:
+				if diff := checkOffLinkRouteEvent(e, llAddr, true); diff != "" {
+					t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
 				}
 			default:
 				t.Fatal("expected router discovery event")
@@ -1482,7 +1485,7 @@ func TestRouterDiscoveryMaxRouters(t *testing.T) {
 
 		} else {
 			select {
-			case <-ndpDisp.routerC:
+			case <-ndpDisp.offLinkRouteC:
 				t.Fatal("should not have discovered a new router after we already discovered the max number of routers")
 			default:
 			}
@@ -4612,9 +4615,9 @@ func TestNoCleanupNDPStateWhenForwardingEnabled(t *testing.T) {
 	)
 
 	ndpDisp := ndpDispatcher{
-		routerC:      make(chan ndpRouterEvent, 1),
-		prefixC:      make(chan ndpPrefixEvent, 1),
-		autoGenAddrC: make(chan ndpAutoGenAddrEvent, 1),
+		offLinkRouteC: make(chan ndpOffLinkRouteEvent, 1),
+		prefixC:       make(chan ndpPrefixEvent, 1),
+		autoGenAddrC:  make(chan ndpAutoGenAddrEvent, 1),
 	}
 	s := stack.New(stack.Options{
 		NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
@@ -4657,17 +4660,17 @@ func TestNoCleanupNDPStateWhenForwardingEnabled(t *testing.T) {
 		),
 	)
 	select {
-	case e := <-ndpDisp.routerC:
-		if diff := checkRouterEvent(e, llAddr3, true /* discovered */); diff != "" {
-			t.Errorf("router event mismatch (-want +got):\n%s", diff)
+	case e := <-ndpDisp.offLinkRouteC:
+		if diff := checkOffLinkRouteEvent(e, llAddr3, true /* discovered */); diff != "" {
+			t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
 		}
 	default:
-		t.Errorf("expected router event for %s on NIC(%d)", llAddr3, nicID)
+		t.Errorf("expected off-link route event for %s on NIC(%d)", llAddr3, nicID)
 	}
 	select {
 	case e := <-ndpDisp.prefixC:
 		if diff := checkPrefixEvent(e, subnet, true /* discovered */); diff != "" {
-			t.Errorf("router event mismatch (-want +got):\n%s", diff)
+			t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
 		}
 	default:
 		t.Errorf("expected prefix event for %s on NIC(%d)", prefix, nicID)
@@ -4689,8 +4692,8 @@ func TestNoCleanupNDPStateWhenForwardingEnabled(t *testing.T) {
 				t.Fatalf("SetForwardingDefaultAndAllNICs(%d, %t): %s", ipv6.ProtocolNumber, forwarding, err)
 			}
 			select {
-			case e := <-ndpDisp.routerC:
-				t.Errorf("unexpected router event = %#v", e)
+			case e := <-ndpDisp.offLinkRouteC:
+				t.Errorf("unexpected off-link route event = %#v", e)
 			default:
 			}
 			select {
@@ -4776,9 +4779,9 @@ func TestCleanupNDPState(t *testing.T) {
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			ndpDisp := ndpDispatcher{
-				routerC:      make(chan ndpRouterEvent, maxRouterAndPrefixEvents),
-				prefixC:      make(chan ndpPrefixEvent, maxRouterAndPrefixEvents),
-				autoGenAddrC: make(chan ndpAutoGenAddrEvent, test.maxAutoGenAddrEvents),
+				offLinkRouteC: make(chan ndpOffLinkRouteEvent, maxRouterAndPrefixEvents),
+				prefixC:       make(chan ndpPrefixEvent, maxRouterAndPrefixEvents),
+				autoGenAddrC:  make(chan ndpAutoGenAddrEvent, test.maxAutoGenAddrEvents),
 			}
 			clock := faketime.NewManualClock()
 			s := stack.New(stack.Options{
@@ -4795,14 +4798,14 @@ func TestCleanupNDPState(t *testing.T) {
 				Clock: clock,
 			})
 
-			expectRouterEvent := func() (bool, ndpRouterEvent) {
+			expectOffLinkRouteEvent := func() (bool, ndpOffLinkRouteEvent) {
 				select {
-				case e := <-ndpDisp.routerC:
+				case e := <-ndpDisp.offLinkRouteC:
 					return true, e
 				default:
 				}
 
-				return false, ndpRouterEvent{}
+				return false, ndpOffLinkRouteEvent{}
 			}
 
 			expectPrefixEvent := func() (bool, ndpPrefixEvent) {
@@ -4847,8 +4850,8 @@ func TestCleanupNDPState(t *testing.T) {
 			// multiple addresses.
 
 			e1.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr3, lifetimeSeconds, prefix1, true, true, lifetimeSeconds, lifetimeSeconds))
-			if ok, _ := expectRouterEvent(); !ok {
-				t.Errorf("expected router event for %s on NIC(%d)", llAddr3, nicID1)
+			if ok, _ := expectOffLinkRouteEvent(); !ok {
+				t.Errorf("expected off-link route event for %s on NIC(%d)", llAddr3, nicID1)
 			}
 			if ok, _ := expectPrefixEvent(); !ok {
 				t.Errorf("expected prefix event for %s on NIC(%d)", prefix1, nicID1)
@@ -4858,8 +4861,8 @@ func TestCleanupNDPState(t *testing.T) {
 			}
 
 			e1.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr4, lifetimeSeconds, prefix2, true, true, lifetimeSeconds, lifetimeSeconds))
-			if ok, _ := expectRouterEvent(); !ok {
-				t.Errorf("expected router event for %s on NIC(%d)", llAddr4, nicID1)
+			if ok, _ := expectOffLinkRouteEvent(); !ok {
+				t.Errorf("expected off-link route event for %s on NIC(%d)", llAddr4, nicID1)
 			}
 			if ok, _ := expectPrefixEvent(); !ok {
 				t.Errorf("expected prefix event for %s on NIC(%d)", prefix2, nicID1)
@@ -4869,8 +4872,8 @@ func TestCleanupNDPState(t *testing.T) {
 			}
 
 			e2.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr3, lifetimeSeconds, prefix1, true, true, lifetimeSeconds, lifetimeSeconds))
-			if ok, _ := expectRouterEvent(); !ok {
-				t.Errorf("expected router event for %s on NIC(%d)", llAddr3, nicID2)
+			if ok, _ := expectOffLinkRouteEvent(); !ok {
+				t.Errorf("expected off-link route event for %s on NIC(%d)", llAddr3, nicID2)
 			}
 			if ok, _ := expectPrefixEvent(); !ok {
 				t.Errorf("expected prefix event for %s on NIC(%d)", prefix1, nicID2)
@@ -4880,8 +4883,8 @@ func TestCleanupNDPState(t *testing.T) {
 			}
 
 			e2.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr4, lifetimeSeconds, prefix2, true, true, lifetimeSeconds, lifetimeSeconds))
-			if ok, _ := expectRouterEvent(); !ok {
-				t.Errorf("expected router event for %s on NIC(%d)", llAddr4, nicID2)
+			if ok, _ := expectOffLinkRouteEvent(); !ok {
+				t.Errorf("expected off-link route event for %s on NIC(%d)", llAddr4, nicID2)
 			}
 			if ok, _ := expectPrefixEvent(); !ok {
 				t.Errorf("expected prefix event for %s on NIC(%d)", prefix2, nicID2)
@@ -4922,14 +4925,14 @@ func TestCleanupNDPState(t *testing.T) {
 			test.cleanupFn(t, s)
 
 			// Collect invalidation events after having NDP state cleaned up.
-			gotRouterEvents := make(map[ndpRouterEvent]int)
+			gotOffLinkRouteEvents := make(map[ndpOffLinkRouteEvent]int)
 			for i := 0; i < maxRouterAndPrefixEvents; i++ {
-				ok, e := expectRouterEvent()
+				ok, e := expectOffLinkRouteEvent()
 				if !ok {
-					t.Errorf("expected %d router events after becoming a router; got = %d", maxRouterAndPrefixEvents, i)
+					t.Errorf("expected %d off-link route events after becoming a router; got = %d", maxRouterAndPrefixEvents, i)
 					break
 				}
-				gotRouterEvents[e]++
+				gotOffLinkRouteEvents[e]++
 			}
 			gotPrefixEvents := make(map[ndpPrefixEvent]int)
 			for i := 0; i < maxRouterAndPrefixEvents; i++ {
@@ -4956,14 +4959,14 @@ func TestCleanupNDPState(t *testing.T) {
 				t.FailNow()
 			}
 
-			expectedRouterEvents := map[ndpRouterEvent]int{
-				{nicID: nicID1, addr: llAddr3, discovered: false}: 1,
-				{nicID: nicID1, addr: llAddr4, discovered: false}: 1,
-				{nicID: nicID2, addr: llAddr3, discovered: false}: 1,
-				{nicID: nicID2, addr: llAddr4, discovered: false}: 1,
+			expectedOffLinkRouteEvents := map[ndpOffLinkRouteEvent]int{
+				{nicID: nicID1, subnet: header.IPv6EmptySubnet, router: llAddr3, updated: false}: 1,
+				{nicID: nicID1, subnet: header.IPv6EmptySubnet, router: llAddr4, updated: false}: 1,
+				{nicID: nicID2, subnet: header.IPv6EmptySubnet, router: llAddr3, updated: false}: 1,
+				{nicID: nicID2, subnet: header.IPv6EmptySubnet, router: llAddr4, updated: false}: 1,
 			}
-			if diff := cmp.Diff(expectedRouterEvents, gotRouterEvents); diff != "" {
-				t.Errorf("router events mismatch (-want +got):\n%s", diff)
+			if diff := cmp.Diff(expectedOffLinkRouteEvents, gotOffLinkRouteEvents); diff != "" {
+				t.Errorf("off-link route events mismatch (-want +got):\n%s", diff)
 			}
 			expectedPrefixEvents := map[ndpPrefixEvent]int{
 				{nicID: nicID1, prefix: subnet1, discovered: false}: 1,
@@ -5027,8 +5030,8 @@ func TestCleanupNDPState(t *testing.T) {
 			// cancelled when the NDP state was cleaned up).
 			clock.Advance(lifetimeSeconds * time.Second)
 			select {
-			case <-ndpDisp.routerC:
-				t.Error("unexpected router event")
+			case <-ndpDisp.offLinkRouteC:
+				t.Error("unexpected off-link route event")
 			default:
 			}
 			select {