2 files changed, 28 insertions, 39 deletions
diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go
index c99d387d5..7d4b41dfa 100644
--- a/pkg/tcpip/stack/ndp.go
+++ b/pkg/tcpip/stack/ndp.go
@@ -432,13 +432,12 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref
 	// Should not attempt to perform DAD on an address that is currently in
 	// the DAD process.
 	if _, ok := ndp.dad[addr]; ok {
-		// Should never happen because we should only ever call this
-		// function for newly created addresses. If we attemped to
-		// "add" an address that already existed, we would returned an
-		// error since we attempted to add a duplicate address, or its
-		// reference count would have been increased without doing the
-		// work that would have been done for an address that was brand
-		// new. See NIC.addPermanentAddressLocked.
+		// Should never happen because we should only ever call this function for
+		// newly created addresses. If we attemped to "add" an address that already
+		// existed, we would get an error since we attempted to add a duplicate
+		// address, or its reference count would have been increased without doing
+		// the work that would have been done for an address that was brand new.
+		// See NIC.addAddressLocked.
 		panic(fmt.Sprintf("ndpdad: already performing DAD for addr %s on NIC(%d)", addr, ndp.nic.ID()))
 	}
 
@@ -994,7 +993,7 @@ func (ndp *ndpState) newAutoGenAddress(prefix tcpip.Subnet, pl, vl time.Duration
 	// If the preferred lifetime is zero, then the address should be considered
 	// deprecated.
 	deprecated := pl == 0
-	ref, err := ndp.nic.addPermanentAddressLocked(protocolAddr, FirstPrimaryEndpoint, slaac, deprecated)
+	ref, err := ndp.nic.addAddressLocked(protocolAddr, FirstPrimaryEndpoint, permanent, slaac, deprecated)
 	if err != nil {
 		log.Fatalf("ndp: error when adding address %s: %s", protocolAddr, err)
 	}
@@ -1164,7 +1163,7 @@ func (ndp *ndpState) cleanupAutoGenAddrResourcesAndNotify(addr tcpip.Address) bo
 //
 // The NIC that ndp belongs to MUST be locked.
 func (ndp *ndpState) cleanupHostOnlyState() {
-	for addr, _ := range ndp.autoGenAddresses {
+	for addr := range ndp.autoGenAddresses {
 		ndp.invalidateAutoGenAddress(addr)
 	}
 
@@ -1172,7 +1171,7 @@ func (ndp *ndpState) cleanupHostOnlyState() {
 		log.Fatalf("ndp: still have auto-generated addresses after cleaning up, found = %d", got)
 	}
 
-	for prefix, _ := range ndp.onLinkPrefixes {
+	for prefix := range ndp.onLinkPrefixes {
 		ndp.invalidateOnLinkPrefix(prefix)
 	}
 
@@ -1180,7 +1179,7 @@ func (ndp *ndpState) cleanupHostOnlyState() {
 		log.Fatalf("ndp: still have discovered on-link prefixes after cleaning up, found = %d", got)
 	}
 
-	for router, _ := range ndp.defaultRouters {
+	for router := range ndp.defaultRouters {
 		ndp.invalidateDefaultRouter(router)
 	}
 
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 4452a1302..53abf29e5 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -196,13 +196,13 @@ func (n *NIC) enable() *tcpip.Error {
 			addr = header.LinkLocalAddr(l2addr)
 		}
 
-		if _, err := n.addPermanentAddressLocked(tcpip.ProtocolAddress{
+		if _, err := n.addAddressLocked(tcpip.ProtocolAddress{
 			Protocol: header.IPv6ProtocolNumber,
 			AddressWithPrefix: tcpip.AddressWithPrefix{
 				Address:   addr,
 				PrefixLen: header.IPv6LinkLocalPrefix.PrefixLen,
 			},
-		}, CanBePrimaryEndpoint, static, false /* deprecated */); err != nil {
+		}, CanBePrimaryEndpoint, permanent, static, false /* deprecated */); err != nil {
 			return err
 		}
 	}
@@ -533,14 +533,21 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t
 	return ref
 }
 
-// addPermanentAddressLocked adds a permanent address to n.
+// addAddressLocked adds a new protocolAddress to n.
 //
-// If n already has the address in a non-permanent state,
-// addPermanentAddressLocked will promote it to permanent and update the
-// endpoint with the properties provided.
-func (n *NIC) addPermanentAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior, configType networkEndpointConfigType, deprecated bool) (*referencedNetworkEndpoint, *tcpip.Error) {
-	id := NetworkEndpointID{protocolAddress.AddressWithPrefix.Address}
+// If n already has the address in a non-permanent state, and the kind given is
+// permanent, that address will be promoted in place and its properties set to
+// the properties provided. Otherwise, it returns tcpip.ErrDuplicateAddress.
+func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior, kind networkEndpointKind, configType networkEndpointConfigType, deprecated bool) (*referencedNetworkEndpoint, *tcpip.Error) {
+	// TODO(b/141022673): Validate IP addresses before adding them.
+
+	// Sanity check.
+	id := NetworkEndpointID{LocalAddress: protocolAddress.AddressWithPrefix.Address}
 	if ref, ok := n.endpoints[id]; ok {
+		// Endpoint already exists.
+		if kind != permanent {
+			return nil, tcpip.ErrDuplicateAddress
+		}
 		switch ref.getKind() {
 		case permanentTentative, permanent:
 			// The NIC already have a permanent endpoint with that address.
@@ -585,23 +592,6 @@ func (n *NIC) addPermanentAddressLocked(protocolAddress tcpip.ProtocolAddress, p
 		}
 	}
 
-	return n.addAddressLocked(protocolAddress, peb, permanent, configType, deprecated)
-}
-
-// addAddressLocked adds a new protocolAddress to n.
-//
-// If the address is already known by n (irrespective of the state it is in),
-// addAddressLocked does nothing and returns tcpip.ErrDuplicateAddress.
-func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior, kind networkEndpointKind, configType networkEndpointConfigType, deprecated bool) (*referencedNetworkEndpoint, *tcpip.Error) {
-	// TODO(b/141022673): Validate IP address before adding them.
-
-	// Sanity check.
-	id := NetworkEndpointID{protocolAddress.AddressWithPrefix.Address}
-	if _, ok := n.endpoints[id]; ok {
-		// Endpoint already exists.
-		return nil, tcpip.ErrDuplicateAddress
-	}
-
 	netProto, ok := n.stack.networkProtocols[protocolAddress.Protocol]
 	if !ok {
 		return nil, tcpip.ErrUnknownProtocol
@@ -666,7 +656,7 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar
 func (n *NIC) AddAddress(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior) *tcpip.Error {
 	// Add the endpoint.
 	n.mu.Lock()
-	_, err := n.addPermanentAddressLocked(protocolAddress, peb, static, false /* deprecated */)
+	_, err := n.addAddressLocked(protocolAddress, peb, permanent, static, false /* deprecated */)
 	n.mu.Unlock()
 
 	return err
@@ -942,13 +932,13 @@ func (n *NIC) joinGroupLocked(protocol tcpip.NetworkProtocolNumber, addr tcpip.A
 		if !ok {
 			return tcpip.ErrUnknownProtocol
 		}
-		if _, err := n.addPermanentAddressLocked(tcpip.ProtocolAddress{
+		if _, err := n.addAddressLocked(tcpip.ProtocolAddress{
 			Protocol: protocol,
 			AddressWithPrefix: tcpip.AddressWithPrefix{
 				Address:   addr,
 				PrefixLen: netProto.DefaultPrefixLen(),
 			},
-		}, NeverPrimaryEndpoint, static, false /* deprecated */); err != nil {
+		}, NeverPrimaryEndpoint, permanent, static, false /* deprecated */); err != nil {
 			return err
 		}
 	}