Rename IsV6LinkLocalAddress to IsV6LinkLocalUnicastAddress

To match the V4 variant.

PiperOrigin-RevId: 367691981

7 files changed, 22 insertions, 21 deletions

diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go
index fa6ccff30..c3a0407ac 100644
--- a/pkg/tcpip/header/ipv6.go
+++ b/pkg/tcpip/header/ipv6.go
@@ -391,23 +391,23 @@ func LinkLocalAddr(linkAddr tcpip.LinkAddress) tcpip.Address {
 	return tcpip.Address(lladdrb[:])
 }
 
-// IsV6LinkLocalAddress determines if the provided address is an IPv6
-// link-local address (fe80::/10).
-func IsV6LinkLocalAddress(addr tcpip.Address) bool {
+// IsV6LinkLocalUnicastAddress returns true iff the provided address is an IPv6
+// link-local unicast address, as defined by RFC 4291 section 2.5.6.
+func IsV6LinkLocalUnicastAddress(addr tcpip.Address) bool {
 	if len(addr) != IPv6AddressSize {
 		return false
 	}
 	return addr[0] == 0xfe && (addr[1]&0xc0) == 0x80
 }
 
-// IsV6LoopbackAddress determines if the provided address is an IPv6 loopback
-// address.
+// IsV6LoopbackAddress returns true iff the provided address is an IPv6 loopback
+// address, as defined by RFC 4291 section 2.5.3.
 func IsV6LoopbackAddress(addr tcpip.Address) bool {
 	return addr == IPv6Loopback
 }
 
-// IsV6LinkLocalMulticastAddress determines if the provided address is an IPv6
-// link-local multicast address.
+// IsV6LinkLocalMulticastAddress returns true iff the provided address is an
+// IPv6 link-local multicast address, as defined by RFC 4291 section 2.7.
 func IsV6LinkLocalMulticastAddress(addr tcpip.Address) bool {
 	return IsV6MulticastAddress(addr) && V6MulticastScope(addr) == IPv6LinkLocalMulticastScope
 }
@@ -472,7 +472,7 @@ func ScopeForIPv6Address(addr tcpip.Address) (IPv6AddressScope, tcpip.Error) {
 	case IsV6LinkLocalMulticastAddress(addr):
 		return LinkLocalScope, nil
 
-	case IsV6LinkLocalAddress(addr):
+	case IsV6LinkLocalUnicastAddress(addr):
 		return LinkLocalScope, nil
 
 	default:
@@ -531,7 +531,8 @@ func GenerateTempIPv6SLAACAddr(tempIIDHistory []byte, stableAddr tcpip.Address)
 	}
 }
 
-// IPv6MulticastScope is the scope of a multicast IPv6 address.
+// IPv6MulticastScope is the scope of a multicast IPv6 address, as defined by
+// RFC 7346 section 2.
 type IPv6MulticastScope uint8
 
 // The various values for IPv6 multicast scopes, as per RFC 7346 section 2:
diff --git a/pkg/tcpip/header/ipv6_test.go b/pkg/tcpip/header/ipv6_test.go
index 38b6dbc18..ccee9000e 100644
--- a/pkg/tcpip/header/ipv6_test.go
+++ b/pkg/tcpip/header/ipv6_test.go
@@ -252,7 +252,7 @@ func TestIsV6LinkLocalMulticastAddress(t *testing.T) {
 	}
 }
 
-func TestIsV6LinkLocalAddress(t *testing.T) {
+func TestIsV6LinkLocalUnicastAddress(t *testing.T) {
 	tests := []struct {
 		name     string
 		addr     tcpip.Address
@@ -287,8 +287,8 @@ func TestIsV6LinkLocalAddress(t *testing.T) {
 
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
-			if got := header.IsV6LinkLocalAddress(test.addr); got != test.expected {
-				t.Errorf("got header.IsV6LinkLocalAddress(%s) = %t, want = %t", test.addr, got, test.expected)
+			if got := header.IsV6LinkLocalUnicastAddress(test.addr); got != test.expected {
+				t.Errorf("got header.IsV6LinkLocalUnicastAddress(%s) = %t, want = %t", test.addr, got, test.expected)
 			}
 		})
 	}
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go
index a142b76c1..b2a80e1e9 100644
--- a/pkg/tcpip/network/ipv6/icmp.go
+++ b/pkg/tcpip/network/ipv6/icmp.go
@@ -273,7 +273,7 @@ func isMLDValid(pkt *stack.PacketBuffer, iph header.IPv6, routerAlert *header.IP
 	if iph.HopLimit() != header.MLDHopLimit {
 		return false
 	}
-	if !header.IsV6LinkLocalAddress(iph.SourceAddress()) {
+	if !header.IsV6LinkLocalUnicastAddress(iph.SourceAddress()) {
 		return false
 	}
 	return true
@@ -804,7 +804,7 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r
 		routerAddr := srcAddr
 
 		// Is the IP Source Address a link-local address?
-		if !header.IsV6LinkLocalAddress(routerAddr) {
+		if !header.IsV6LinkLocalUnicastAddress(routerAddr) {
 			// ...No, silently drop the packet.
 			received.invalid.Increment()
 			return
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 7ee7be0f9..d36cefcd0 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -314,7 +314,7 @@ func (e *endpoint) onAddressAssignedLocked(addr tcpip.Address) {
 	//   Snooping switches MUST manage multicast forwarding state based on MLD
 	//   Report and Done messages sent with the unspecified address as the
 	//   IPv6 source address.
-	if header.IsV6LinkLocalAddress(addr) {
+	if header.IsV6LinkLocalUnicastAddress(addr) {
 		e.mu.mld.sendQueuedReports()
 	}
 }
@@ -914,7 +914,7 @@ func (e *endpoint) forwardPacket(pkt *stack.PacketBuffer) tcpip.Error {
 	h := header.IPv6(pkt.NetworkHeader().View())
 
 	dstAddr := h.DestinationAddress()
-	if header.IsV6LinkLocalAddress(h.SourceAddress()) || header.IsV6LinkLocalAddress(dstAddr) || header.IsV6LinkLocalMulticastAddress(dstAddr) {
+	if header.IsV6LinkLocalUnicastAddress(h.SourceAddress()) || header.IsV6LinkLocalUnicastAddress(dstAddr) || header.IsV6LinkLocalMulticastAddress(dstAddr) {
 		// As per RFC 4291 section 2.5.6,
 		//
 		//   Routers must not forward any packets with Link-Local source or
@@ -1622,7 +1622,7 @@ func (e *endpoint) getLinkLocalAddressRLocked() tcpip.Address {
 	var linkLocalAddr tcpip.Address
 	e.mu.addressableEndpointState.ForEachPrimaryEndpoint(func(addressEndpoint stack.AddressEndpoint) bool {
 		if addressEndpoint.IsAssigned(false /* allowExpired */) {
-			if addr := addressEndpoint.AddressWithPrefix().Address; header.IsV6LinkLocalAddress(addr) {
+			if addr := addressEndpoint.AddressWithPrefix().Address; header.IsV6LinkLocalUnicastAddress(addr) {
 				linkLocalAddr = addr
 				return false
 			}
diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go
index dd7f6a126..a110faa54 100644
--- a/pkg/tcpip/network/ipv6/ndp.go
+++ b/pkg/tcpip/network/ipv6/ndp.go
@@ -737,7 +737,7 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) {
 			prefix := opt.Subnet()
 
 			// Is the prefix a link-local?
-			if header.IsV6LinkLocalAddress(prefix.ID()) {
+			if header.IsV6LinkLocalUnicastAddress(prefix.ID()) {
 				// ...Yes, skip as per RFC 4861 section 6.3.4,
 				// and RFC 4862 section 5.5.3.b (for SLAAC).
 				continue
diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go
index 39344808d..4ae6bed5a 100644
--- a/pkg/tcpip/stack/route.go
+++ b/pkg/tcpip/stack/route.go
@@ -132,7 +132,7 @@ func constructAndValidateRoute(netProto tcpip.NetworkProtocolNumber, addressEndp
 		localAddr = addressEndpoint.AddressWithPrefix().Address
 	}
 
-	if localAddressNIC != outgoingNIC && header.IsV6LinkLocalAddress(localAddr) {
+	if localAddressNIC != outgoingNIC && header.IsV6LinkLocalUnicastAddress(localAddr) {
 		addressEndpoint.DecRef()
 		return nil
 	}
diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go
index 931a97ddc..f23112410 100644
--- a/pkg/tcpip/stack/stack.go
+++ b/pkg/tcpip/stack/stack.go
@@ -1344,7 +1344,7 @@ func (s *Stack) FindRoute(id tcpip.NICID, localAddr, remoteAddr tcpip.Address, n
 	s.mu.RLock()
 	defer s.mu.RUnlock()
 
-	isLinkLocal := header.IsV6LinkLocalAddress(remoteAddr) || header.IsV6LinkLocalMulticastAddress(remoteAddr)
+	isLinkLocal := header.IsV6LinkLocalUnicastAddress(remoteAddr) || header.IsV6LinkLocalMulticastAddress(remoteAddr)
 	isLocalBroadcast := remoteAddr == header.IPv4Broadcast
 	isMulticast := header.IsV4MulticastAddress(remoteAddr) || header.IsV6MulticastAddress(remoteAddr)
 	isLoopback := header.IsV4LoopbackAddress(remoteAddr) || header.IsV6LoopbackAddress(remoteAddr)
@@ -1381,7 +1381,7 @@ func (s *Stack) FindRoute(id tcpip.NICID, localAddr, remoteAddr tcpip.Address, n
 		return nil, &tcpip.ErrNetworkUnreachable{}
 	}
 
-	canForward := s.Forwarding(netProto) && !header.IsV6LinkLocalAddress(localAddr) && !isLinkLocal
+	canForward := s.Forwarding(netProto) && !header.IsV6LinkLocalUnicastAddress(localAddr) && !isLinkLocal
 
 	// Find a route to the remote with the route table.
 	var chosenRoute tcpip.Route