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

2 files changed, 8 insertions, 10 deletions

diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go
index 70b699b2e..ee36ed254 100644
--- a/pkg/tcpip/network/ipv6/ndp.go
+++ b/pkg/tcpip/network/ipv6/ndp.go
@@ -214,19 +214,17 @@ type NDPDispatcher interface {
 	// is also not permitted to call into the stack.
 	OnDuplicateAddressDetectionResult(tcpip.NICID, tcpip.Address, stack.DADResult)
 
-	// OnDefaultRouterDiscovered is called when a new default router is
-	// discovered.
+	// OnOffLinkRouteUpdated is called when an off-link route is updated.
 	//
 	// This function is not permitted to block indefinitely. This function
 	// is also not permitted to call into the stack.
-	OnDefaultRouterDiscovered(tcpip.NICID, tcpip.Address)
+	OnOffLinkRouteUpdated(tcpip.NICID, tcpip.Subnet, tcpip.Address)
 
-	// OnDefaultRouterInvalidated is called when a discovered default router that
-	// was remembered is invalidated.
+	// OnOffLinkRouteInvalidated is called when an off-link route is invalidated.
 	//
 	// This function is not permitted to block indefinitely. This function
 	// is also not permitted to call into the stack.
-	OnDefaultRouterInvalidated(tcpip.NICID, tcpip.Address)
+	OnOffLinkRouteInvalidated(tcpip.NICID, tcpip.Subnet, tcpip.Address)
 
 	// OnOnLinkPrefixDiscovered is called when a new on-link prefix is discovered.
 	//
@@ -826,7 +824,7 @@ func (ndp *ndpState) invalidateDefaultRouter(ip tcpip.Address) {
 
 	// Let the integrator know a discovered default router is invalidated.
 	if ndpDisp := ndp.ep.protocol.options.NDPDisp; ndpDisp != nil {
-		ndpDisp.OnDefaultRouterInvalidated(ndp.ep.nic.ID(), ip)
+		ndpDisp.OnOffLinkRouteInvalidated(ndp.ep.nic.ID(), header.IPv6EmptySubnet, ip)
 	}
 }
 
@@ -843,7 +841,7 @@ func (ndp *ndpState) rememberDefaultRouter(ip tcpip.Address, rl time.Duration) {
 	}
 
 	// Inform the integrator when we discovered a default router.
-	ndpDisp.OnDefaultRouterDiscovered(ndp.ep.nic.ID(), ip)
+	ndpDisp.OnOffLinkRouteUpdated(ndp.ep.nic.ID(), header.IPv6EmptySubnet, ip)
 
 	state := defaultRouterState{
 		invalidationJob: ndp.ep.protocol.stack.NewJob(&ndp.ep.mu, func() {
diff --git a/pkg/tcpip/network/ipv6/ndp_test.go b/pkg/tcpip/network/ipv6/ndp_test.go
index 7b4774abb..95d23f200 100644
--- a/pkg/tcpip/network/ipv6/ndp_test.go
+++ b/pkg/tcpip/network/ipv6/ndp_test.go
@@ -42,11 +42,11 @@ type testNDPDispatcher struct {
 func (*testNDPDispatcher) OnDuplicateAddressDetectionResult(tcpip.NICID, tcpip.Address, stack.DADResult) {
 }
 
-func (t *testNDPDispatcher) OnDefaultRouterDiscovered(_ tcpip.NICID, addr tcpip.Address) {
+func (t *testNDPDispatcher) OnOffLinkRouteUpdated(_ tcpip.NICID, _ tcpip.Subnet, addr tcpip.Address) {
 	t.addr = addr
 }
 
-func (t *testNDPDispatcher) OnDefaultRouterInvalidated(_ tcpip.NICID, addr tcpip.Address) {
+func (t *testNDPDispatcher) OnOffLinkRouteInvalidated(_ tcpip.NICID, _ tcpip.Subnet, addr tcpip.Address) {
 	t.addr = addr
 }