Unexpose NIC

The NIC structure is not to be used outside of the stack package
directly.

PiperOrigin-RevId: 356036737

1 files changed, 57 insertions, 57 deletions

diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index a90d027f2..6c09ba5ff 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -39,7 +39,7 @@ type neighborTable interface {
 	setNUDConfig(NUDConfigurations) tcpip.Error
 }
 
-var _ NetworkInterface = (*NIC)(nil)
+var _ NetworkInterface = (*nic)(nil)
 
 type linkResolver struct {
 	resolver LinkAddressResolver
@@ -55,9 +55,9 @@ func (l *linkResolver) confirmReachable(addr tcpip.Address) {
 	l.neighborTable.handleUpperLevelConfirmation(addr)
 }
 
-// NIC represents a "network interface card" to which the networking stack is
+// nic represents a "network interface card" to which the networking stack is
 // attached.
-type NIC struct {
+type nic struct {
 	LinkEndpoint
 
 	stack   *Stack
@@ -147,7 +147,7 @@ func (p *packetEndpointList) forEach(fn func(PacketEndpoint)) {
 }
 
 // newNIC returns a new NIC using the default NDP configurations from stack.
-func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICContext) *NIC {
+func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICContext) *nic {
 	// TODO(b/141011931): Validate a LinkEndpoint (ep) is valid. For
 	// example, make sure that the link address it provides is a valid
 	// unicast ethernet address.
@@ -156,7 +156,7 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC
 	// observe an MTU of at least 1280 bytes. Ensure that this requirement
 	// of IPv6 is supported on this endpoint's LinkEndpoint.
 
-	nic := &NIC{
+	nic := &nic{
 		LinkEndpoint: ep,
 
 		stack:             stack,
@@ -212,19 +212,19 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC
 	return nic
 }
 
-func (n *NIC) getNetworkEndpoint(proto tcpip.NetworkProtocolNumber) NetworkEndpoint {
+func (n *nic) getNetworkEndpoint(proto tcpip.NetworkProtocolNumber) NetworkEndpoint {
 	return n.networkEndpoints[proto]
 }
 
 // Enabled implements NetworkInterface.
-func (n *NIC) Enabled() bool {
+func (n *nic) Enabled() bool {
 	return atomic.LoadUint32(&n.enabled) == 1
 }
 
 // setEnabled sets the enabled status for the NIC.
 //
 // Returns true if the enabled status was updated.
-func (n *NIC) setEnabled(v bool) bool {
+func (n *nic) setEnabled(v bool) bool {
 	if v {
 		return atomic.SwapUint32(&n.enabled, 1) == 0
 	}
@@ -234,7 +234,7 @@ func (n *NIC) setEnabled(v bool) bool {
 // disable disables n.
 //
 // It undoes the work done by enable.
-func (n *NIC) disable() {
+func (n *nic) disable() {
 	n.mu.Lock()
 	n.disableLocked()
 	n.mu.Unlock()
@@ -245,7 +245,7 @@ func (n *NIC) disable() {
 // It undoes the work done by enable.
 //
 // n MUST be locked.
-func (n *NIC) disableLocked() {
+func (n *nic) disableLocked() {
 	if !n.Enabled() {
 		return
 	}
@@ -283,7 +283,7 @@ func (n *NIC) disableLocked() {
 // address (ff02::1), start DAD for permanent addresses, and start soliciting
 // routers if the stack is not operating as a router. If the stack is also
 // configured to auto-generate a link-local address, one will be generated.
-func (n *NIC) enable() tcpip.Error {
+func (n *nic) enable() tcpip.Error {
 	n.mu.Lock()
 	defer n.mu.Unlock()
 
@@ -303,7 +303,7 @@ func (n *NIC) enable() tcpip.Error {
 // remove detaches NIC from the link endpoint and releases network endpoint
 // resources. This guarantees no packets between this NIC and the network
 // stack.
-func (n *NIC) remove() tcpip.Error {
+func (n *nic) remove() tcpip.Error {
 	n.mu.Lock()
 	defer n.mu.Unlock()
 
@@ -319,14 +319,14 @@ func (n *NIC) remove() tcpip.Error {
 }
 
 // setPromiscuousMode enables or disables promiscuous mode.
-func (n *NIC) setPromiscuousMode(enable bool) {
+func (n *nic) setPromiscuousMode(enable bool) {
 	n.mu.Lock()
 	n.mu.promiscuous = enable
 	n.mu.Unlock()
 }
 
 // Promiscuous implements NetworkInterface.
-func (n *NIC) Promiscuous() bool {
+func (n *nic) Promiscuous() bool {
 	n.mu.RLock()
 	rv := n.mu.promiscuous
 	n.mu.RUnlock()
@@ -334,17 +334,17 @@ func (n *NIC) Promiscuous() bool {
 }
 
 // IsLoopback implements NetworkInterface.
-func (n *NIC) IsLoopback() bool {
+func (n *nic) IsLoopback() bool {
 	return n.LinkEndpoint.Capabilities()&CapabilityLoopback != 0
 }
 
 // WritePacket implements NetworkLinkEndpoint.
-func (n *NIC) WritePacket(r *Route, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) tcpip.Error {
+func (n *nic) WritePacket(r *Route, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) tcpip.Error {
 	_, err := n.enqueuePacketBuffer(r, gso, protocol, pkt)
 	return err
 }
 
-func (n *NIC) writePacketBuffer(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt pendingPacketBuffer) (int, tcpip.Error) {
+func (n *nic) writePacketBuffer(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt pendingPacketBuffer) (int, tcpip.Error) {
 	switch pkt := pkt.(type) {
 	case *PacketBuffer:
 		if err := n.writePacket(r, gso, protocol, pkt); err != nil {
@@ -358,7 +358,7 @@ func (n *NIC) writePacketBuffer(r RouteInfo, gso *GSO, protocol tcpip.NetworkPro
 	}
 }
 
-func (n *NIC) enqueuePacketBuffer(r *Route, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt pendingPacketBuffer) (int, tcpip.Error) {
+func (n *nic) enqueuePacketBuffer(r *Route, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt pendingPacketBuffer) (int, tcpip.Error) {
 	routeInfo, _, err := r.resolvedFields(nil)
 	switch err.(type) {
 	case nil:
@@ -388,14 +388,14 @@ func (n *NIC) enqueuePacketBuffer(r *Route, gso *GSO, protocol tcpip.NetworkProt
 }
 
 // WritePacketToRemote implements NetworkInterface.
-func (n *NIC) WritePacketToRemote(remoteLinkAddr tcpip.LinkAddress, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) tcpip.Error {
+func (n *nic) WritePacketToRemote(remoteLinkAddr tcpip.LinkAddress, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) tcpip.Error {
 	var r RouteInfo
 	r.NetProto = protocol
 	r.RemoteLinkAddress = remoteLinkAddr
 	return n.writePacket(r, gso, protocol, pkt)
 }
 
-func (n *NIC) writePacket(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) tcpip.Error {
+func (n *nic) writePacket(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) tcpip.Error {
 	// WritePacket takes ownership of pkt, calculate numBytes first.
 	numBytes := pkt.Size()
 
@@ -412,11 +412,11 @@ func (n *NIC) writePacket(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolN
 }
 
 // WritePackets implements NetworkLinkEndpoint.
-func (n *NIC) WritePackets(r *Route, gso *GSO, pkts PacketBufferList, protocol tcpip.NetworkProtocolNumber) (int, tcpip.Error) {
+func (n *nic) WritePackets(r *Route, gso *GSO, pkts PacketBufferList, protocol tcpip.NetworkProtocolNumber) (int, tcpip.Error) {
 	return n.enqueuePacketBuffer(r, gso, protocol, &pkts)
 }
 
-func (n *NIC) writePackets(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkts PacketBufferList) (int, tcpip.Error) {
+func (n *nic) writePackets(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocolNumber, pkts PacketBufferList) (int, tcpip.Error) {
 	for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() {
 		pkt.EgressRoute = r
 		pkt.GSOOptions = gso
@@ -435,14 +435,14 @@ func (n *NIC) writePackets(r RouteInfo, gso *GSO, protocol tcpip.NetworkProtocol
 }
 
 // setSpoofing enables or disables address spoofing.
-func (n *NIC) setSpoofing(enable bool) {
+func (n *nic) setSpoofing(enable bool) {
 	n.mu.Lock()
 	n.mu.spoofing = enable
 	n.mu.Unlock()
 }
 
 // Spoofing implements NetworkInterface.
-func (n *NIC) Spoofing() bool {
+func (n *nic) Spoofing() bool {
 	n.mu.RLock()
 	defer n.mu.RUnlock()
 	return n.mu.spoofing
@@ -450,7 +450,7 @@ func (n *NIC) Spoofing() bool {
 
 // primaryAddress returns an address that can be used to communicate with
 // remoteAddr.
-func (n *NIC) primaryEndpoint(protocol tcpip.NetworkProtocolNumber, remoteAddr tcpip.Address) AssignableAddressEndpoint {
+func (n *nic) primaryEndpoint(protocol tcpip.NetworkProtocolNumber, remoteAddr tcpip.Address) AssignableAddressEndpoint {
 	ep, ok := n.networkEndpoints[protocol]
 	if !ok {
 		return nil
@@ -480,11 +480,11 @@ const (
 	promiscuous
 )
 
-func (n *NIC) getAddress(protocol tcpip.NetworkProtocolNumber, dst tcpip.Address) AssignableAddressEndpoint {
+func (n *nic) getAddress(protocol tcpip.NetworkProtocolNumber, dst tcpip.Address) AssignableAddressEndpoint {
 	return n.getAddressOrCreateTemp(protocol, dst, CanBePrimaryEndpoint, promiscuous)
 }
 
-func (n *NIC) hasAddress(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) bool {
+func (n *nic) hasAddress(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) bool {
 	ep := n.getAddressOrCreateTempInner(protocol, addr, false, NeverPrimaryEndpoint)
 	if ep != nil {
 		ep.DecRef()
@@ -495,7 +495,7 @@ func (n *NIC) hasAddress(protocol tcpip.NetworkProtocolNumber, addr tcpip.Addres
 }
 
 // findEndpoint finds the endpoint, if any, with the given address.
-func (n *NIC) findEndpoint(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior) AssignableAddressEndpoint {
+func (n *nic) findEndpoint(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior) AssignableAddressEndpoint {
 	return n.getAddressOrCreateTemp(protocol, address, peb, spoofing)
 }
 
@@ -508,7 +508,7 @@ func (n *NIC) findEndpoint(protocol tcpip.NetworkProtocolNumber, address tcpip.A
 //
 // If the address is the IPv4 broadcast address for an endpoint's network, that
 // endpoint will be returned.
-func (n *NIC) getAddressOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior, tempRef getAddressBehaviour) AssignableAddressEndpoint {
+func (n *nic) getAddressOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior, tempRef getAddressBehaviour) AssignableAddressEndpoint {
 	n.mu.RLock()
 	var spoofingOrPromiscuous bool
 	switch tempRef {
@@ -523,7 +523,7 @@ func (n *NIC) getAddressOrCreateTemp(protocol tcpip.NetworkProtocolNumber, addre
 
 // getAddressOrCreateTempInner is like getAddressEpOrCreateTemp except a boolean
 // is passed to indicate whether or not we should generate temporary endpoints.
-func (n *NIC) getAddressOrCreateTempInner(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, createTemp bool, peb PrimaryEndpointBehavior) AssignableAddressEndpoint {
+func (n *nic) getAddressOrCreateTempInner(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, createTemp bool, peb PrimaryEndpointBehavior) AssignableAddressEndpoint {
 	ep, ok := n.networkEndpoints[protocol]
 	if !ok {
 		return nil
@@ -539,7 +539,7 @@ func (n *NIC) getAddressOrCreateTempInner(protocol tcpip.NetworkProtocolNumber,
 
 // addAddress adds a new address to n, so that it starts accepting packets
 // targeted at the given address (and network protocol).
-func (n *NIC) addAddress(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior) tcpip.Error {
+func (n *nic) addAddress(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior) tcpip.Error {
 	ep, ok := n.networkEndpoints[protocolAddress.Protocol]
 	if !ok {
 		return &tcpip.ErrUnknownProtocol{}
@@ -560,7 +560,7 @@ func (n *NIC) addAddress(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpo
 
 // allPermanentAddresses returns all permanent addresses associated with
 // this NIC.
-func (n *NIC) allPermanentAddresses() []tcpip.ProtocolAddress {
+func (n *nic) allPermanentAddresses() []tcpip.ProtocolAddress {
 	var addrs []tcpip.ProtocolAddress
 	for p, ep := range n.networkEndpoints {
 		addressableEndpoint, ok := ep.(AddressableEndpoint)
@@ -576,7 +576,7 @@ func (n *NIC) allPermanentAddresses() []tcpip.ProtocolAddress {
 }
 
 // primaryAddresses returns the primary addresses associated with this NIC.
-func (n *NIC) primaryAddresses() []tcpip.ProtocolAddress {
+func (n *nic) primaryAddresses() []tcpip.ProtocolAddress {
 	var addrs []tcpip.ProtocolAddress
 	for p, ep := range n.networkEndpoints {
 		addressableEndpoint, ok := ep.(AddressableEndpoint)
@@ -596,7 +596,7 @@ func (n *NIC) primaryAddresses() []tcpip.ProtocolAddress {
 // primaryAddress will return the first non-deprecated address if such an
 // address exists. If no non-deprecated address exists, the first deprecated
 // address will be returned.
-func (n *NIC) primaryAddress(proto tcpip.NetworkProtocolNumber) tcpip.AddressWithPrefix {
+func (n *nic) primaryAddress(proto tcpip.NetworkProtocolNumber) tcpip.AddressWithPrefix {
 	ep, ok := n.networkEndpoints[proto]
 	if !ok {
 		return tcpip.AddressWithPrefix{}
@@ -611,7 +611,7 @@ func (n *NIC) primaryAddress(proto tcpip.NetworkProtocolNumber) tcpip.AddressWit
 }
 
 // removeAddress removes an address from n.
-func (n *NIC) removeAddress(addr tcpip.Address) tcpip.Error {
+func (n *nic) removeAddress(addr tcpip.Address) tcpip.Error {
 	for _, ep := range n.networkEndpoints {
 		addressableEndpoint, ok := ep.(AddressableEndpoint)
 		if !ok {
@@ -629,7 +629,7 @@ func (n *NIC) removeAddress(addr tcpip.Address) tcpip.Error {
 	return &tcpip.ErrBadLocalAddress{}
 }
 
-func (n *NIC) getLinkAddress(addr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, onResolve func(LinkResolutionResult)) tcpip.Error {
+func (n *nic) getLinkAddress(addr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, onResolve func(LinkResolutionResult)) tcpip.Error {
 	linkRes, ok := n.linkAddrResolvers[protocol]
 	if !ok {
 		return &tcpip.ErrNotSupported{}
@@ -644,7 +644,7 @@ func (n *NIC) getLinkAddress(addr, localAddr tcpip.Address, protocol tcpip.Netwo
 	return err
 }
 
-func (n *NIC) neighbors(protocol tcpip.NetworkProtocolNumber) ([]NeighborEntry, tcpip.Error) {
+func (n *nic) neighbors(protocol tcpip.NetworkProtocolNumber) ([]NeighborEntry, tcpip.Error) {
 	if linkRes, ok := n.linkAddrResolvers[protocol]; ok {
 		return linkRes.neighborTable.neighbors()
 	}
@@ -652,7 +652,7 @@ func (n *NIC) neighbors(protocol tcpip.NetworkProtocolNumber) ([]NeighborEntry,
 	return nil, &tcpip.ErrNotSupported{}
 }
 
-func (n *NIC) addStaticNeighbor(addr tcpip.Address, protocol tcpip.NetworkProtocolNumber, linkAddress tcpip.LinkAddress) tcpip.Error {
+func (n *nic) addStaticNeighbor(addr tcpip.Address, protocol tcpip.NetworkProtocolNumber, linkAddress tcpip.LinkAddress) tcpip.Error {
 	if linkRes, ok := n.linkAddrResolvers[protocol]; ok {
 		linkRes.neighborTable.addStaticEntry(addr, linkAddress)
 		return nil
@@ -661,7 +661,7 @@ func (n *NIC) addStaticNeighbor(addr tcpip.Address, protocol tcpip.NetworkProtoc
 	return &tcpip.ErrNotSupported{}
 }
 
-func (n *NIC) removeNeighbor(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.Error {
+func (n *nic) removeNeighbor(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.Error {
 	if linkRes, ok := n.linkAddrResolvers[protocol]; ok {
 		return linkRes.neighborTable.remove(addr)
 	}
@@ -669,7 +669,7 @@ func (n *NIC) removeNeighbor(protocol tcpip.NetworkProtocolNumber, addr tcpip.Ad
 	return &tcpip.ErrNotSupported{}
 }
 
-func (n *NIC) clearNeighbors(protocol tcpip.NetworkProtocolNumber) tcpip.Error {
+func (n *nic) clearNeighbors(protocol tcpip.NetworkProtocolNumber) tcpip.Error {
 	if linkRes, ok := n.linkAddrResolvers[protocol]; ok {
 		return linkRes.neighborTable.removeAll()
 	}
@@ -679,7 +679,7 @@ func (n *NIC) clearNeighbors(protocol tcpip.NetworkProtocolNumber) tcpip.Error {
 
 // joinGroup adds a new endpoint for the given multicast address, if none
 // exists yet. Otherwise it just increments its count.
-func (n *NIC) joinGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.Error {
+func (n *nic) joinGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.Error {
 	// TODO(b/143102137): When implementing MLD, make sure MLD packets are
 	// not sent unless a valid link-local address is available for use on n
 	// as an MLD packet's source address must be a link-local address as
@@ -700,7 +700,7 @@ func (n *NIC) joinGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address
 
 // leaveGroup decrements the count for the given multicast address, and when it
 // reaches zero removes the endpoint for this address.
-func (n *NIC) leaveGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.Error {
+func (n *nic) leaveGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) tcpip.Error {
 	ep, ok := n.networkEndpoints[protocol]
 	if !ok {
 		return &tcpip.ErrNotSupported{}
@@ -715,7 +715,7 @@ func (n *NIC) leaveGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Addres
 }
 
 // isInGroup returns true if n has joined the multicast group addr.
-func (n *NIC) isInGroup(addr tcpip.Address) bool {
+func (n *nic) isInGroup(addr tcpip.Address) bool {
 	for _, ep := range n.networkEndpoints {
 		gep, ok := ep.(GroupAddressableEndpoint)
 		if !ok {
@@ -736,7 +736,7 @@ func (n *NIC) isInGroup(addr tcpip.Address) bool {
 // Note that the ownership of the slice backing vv is retained by the caller.
 // This rule applies only to the slice itself, not to the items of the slice;
 // the ownership of the items is not retained by the caller.
-func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) {
+func (n *nic) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) {
 	n.mu.RLock()
 	enabled := n.Enabled()
 	// If the NIC is not yet enabled, don't receive any packets.
@@ -788,7 +788,7 @@ func (n *NIC) DeliverNetworkPacket(remote, local tcpip.LinkAddress, protocol tcp
 }
 
 // DeliverOutboundPacket implements NetworkDispatcher.DeliverOutboundPacket.
-func (n *NIC) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) {
+func (n *nic) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt *PacketBuffer) {
 	n.mu.RLock()
 	// We do not deliver to protocol specific packet endpoints as on Linux
 	// only ETH_P_ALL endpoints get outbound packets.
@@ -808,7 +808,7 @@ func (n *NIC) DeliverOutboundPacket(remote, local tcpip.LinkAddress, protocol tc
 
 // DeliverTransportPacket delivers the packets to the appropriate transport
 // protocol endpoint.
-func (n *NIC) DeliverTransportPacket(protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) TransportPacketDisposition {
+func (n *nic) DeliverTransportPacket(protocol tcpip.TransportProtocolNumber, pkt *PacketBuffer) TransportPacketDisposition {
 	state, ok := n.stack.transportProtocols[protocol]
 	if !ok {
 		n.stack.stats.UnknownProtocolRcvdPackets.Increment()
@@ -889,7 +889,7 @@ func (n *NIC) DeliverTransportPacket(protocol tcpip.TransportProtocolNumber, pkt
 }
 
 // DeliverTransportError implements TransportDispatcher.
-func (n *NIC) DeliverTransportError(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, transErr TransportError, pkt *PacketBuffer) {
+func (n *nic) DeliverTransportError(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, transErr TransportError, pkt *PacketBuffer) {
 	state, ok := n.stack.transportProtocols[trans]
 	if !ok {
 		return
@@ -917,17 +917,17 @@ func (n *NIC) DeliverTransportError(local, remote tcpip.Address, net tcpip.Netwo
 }
 
 // ID implements NetworkInterface.
-func (n *NIC) ID() tcpip.NICID {
+func (n *nic) ID() tcpip.NICID {
 	return n.id
 }
 
 // Name implements NetworkInterface.
-func (n *NIC) Name() string {
+func (n *nic) Name() string {
 	return n.name
 }
 
 // nudConfigs gets the NUD configurations for n.
-func (n *NIC) nudConfigs(protocol tcpip.NetworkProtocolNumber) (NUDConfigurations, tcpip.Error) {
+func (n *nic) nudConfigs(protocol tcpip.NetworkProtocolNumber) (NUDConfigurations, tcpip.Error) {
 	if linkRes, ok := n.linkAddrResolvers[protocol]; ok {
 		return linkRes.neighborTable.nudConfig()
 	}
@@ -939,7 +939,7 @@ func (n *NIC) nudConfigs(protocol tcpip.NetworkProtocolNumber) (NUDConfiguration
 //
 // Note, if c contains invalid NUD configuration values, it will be fixed to
 // use default values for the erroneous values.
-func (n *NIC) setNUDConfigs(protocol tcpip.NetworkProtocolNumber, c NUDConfigurations) tcpip.Error {
+func (n *nic) setNUDConfigs(protocol tcpip.NetworkProtocolNumber, c NUDConfigurations) tcpip.Error {
 	if linkRes, ok := n.linkAddrResolvers[protocol]; ok {
 		c.resetInvalidFields()
 		return linkRes.neighborTable.setNUDConfig(c)
@@ -948,7 +948,7 @@ func (n *NIC) setNUDConfigs(protocol tcpip.NetworkProtocolNumber, c NUDConfigura
 	return &tcpip.ErrNotSupported{}
 }
 
-func (n *NIC) registerPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep PacketEndpoint) tcpip.Error {
+func (n *nic) registerPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep PacketEndpoint) tcpip.Error {
 	n.mu.Lock()
 	defer n.mu.Unlock()
 
@@ -961,7 +961,7 @@ func (n *NIC) registerPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep Pa
 	return nil
 }
 
-func (n *NIC) unregisterPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep PacketEndpoint) {
+func (n *nic) unregisterPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep PacketEndpoint) {
 	n.mu.Lock()
 	defer n.mu.Unlock()
 
@@ -975,7 +975,7 @@ func (n *NIC) unregisterPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep
 // isValidForOutgoing returns true if the endpoint can be used to send out a
 // packet. It requires the endpoint to not be marked expired (i.e., its address
 // has been removed) unless the NIC is in spoofing mode, or temporary.
-func (n *NIC) isValidForOutgoing(ep AssignableAddressEndpoint) bool {
+func (n *nic) isValidForOutgoing(ep AssignableAddressEndpoint) bool {
 	n.mu.RLock()
 	spoofing := n.mu.spoofing
 	n.mu.RUnlock()
@@ -983,7 +983,7 @@ func (n *NIC) isValidForOutgoing(ep AssignableAddressEndpoint) bool {
 }
 
 // HandleNeighborProbe implements NetworkInterface.
-func (n *NIC) HandleNeighborProbe(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address, linkAddr tcpip.LinkAddress) tcpip.Error {
+func (n *nic) HandleNeighborProbe(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address, linkAddr tcpip.LinkAddress) tcpip.Error {
 	if l, ok := n.linkAddrResolvers[protocol]; ok {
 		l.neighborTable.handleProbe(addr, linkAddr)
 		return nil
@@ -993,7 +993,7 @@ func (n *NIC) HandleNeighborProbe(protocol tcpip.NetworkProtocolNumber, addr tcp
 }
 
 // HandleNeighborConfirmation implements NetworkInterface.
-func (n *NIC) HandleNeighborConfirmation(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address, linkAddr tcpip.LinkAddress, flags ReachabilityConfirmationFlags) tcpip.Error {
+func (n *nic) HandleNeighborConfirmation(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address, linkAddr tcpip.LinkAddress, flags ReachabilityConfirmationFlags) tcpip.Error {
 	if l, ok := n.linkAddrResolvers[protocol]; ok {
 		l.neighborTable.handleConfirmation(addr, linkAddr, flags)
 		return nil
@@ -1003,7 +1003,7 @@ func (n *NIC) HandleNeighborConfirmation(protocol tcpip.NetworkProtocolNumber, a
 }
 
 // CheckLocalAddress implements NetworkInterface.
-func (n *NIC) CheckLocalAddress(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) bool {
+func (n *nic) CheckLocalAddress(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address) bool {
 	if n.Spoofing() {
 		return true
 	}