Refactor default router state to off-link route state

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

The newly introduced off-link route state will be used to hold
both the state for default routers (which is a default (off-link)
route through the router, and more-specific routes (which are
routes through some router to some destination subnet more specific
than the IPv6 empty subnet).

Updates #6172.

PiperOrigin-RevId: 381403761

1 files changed, 3 insertions, 3 deletions

diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go
index bd512d312..9623d9c28 100644
--- a/pkg/tcpip/stack/ndp_test.go
+++ b/pkg/tcpip/stack/ndp_test.go
@@ -1461,7 +1461,7 @@ func TestRouterDiscovery(t *testing.T) {
 }
 
 // TestRouterDiscoveryMaxRouters tests that only
-// ipv6.MaxDiscoveredDefaultRouters discovered routers are remembered.
+// ipv6.MaxDiscoveredOffLinkRoutes discovered routers are remembered.
 func TestRouterDiscoveryMaxRouters(t *testing.T) {
 	const nicID = 1
 
@@ -1484,14 +1484,14 @@ func TestRouterDiscoveryMaxRouters(t *testing.T) {
 	}
 
 	// Receive an RA from 2 more than the max number of discovered routers.
-	for i := 1; i <= ipv6.MaxDiscoveredDefaultRouters+2; i++ {
+	for i := 1; i <= ipv6.MaxDiscoveredOffLinkRoutes+2; i++ {
 		linkAddr := []byte{2, 2, 3, 4, 5, 0}
 		linkAddr[5] = byte(i)
 		llAddr := header.LinkLocalAddr(tcpip.LinkAddress(linkAddr))
 
 		e.InjectInbound(header.IPv6ProtocolNumber, raBufSimple(llAddr, 5))
 
-		if i <= ipv6.MaxDiscoveredDefaultRouters {
+		if i <= ipv6.MaxDiscoveredOffLinkRoutes {
 			select {
 			case e := <-ndpDisp.offLinkRouteC:
 				if diff := checkOffLinkRouteEvent(e, nicID, llAddr, header.MediumRoutePreference, true); diff != "" {