diff options
Diffstat (limited to 'pkg/tcpip/stack/nic.go')
-rw-r--r-- | pkg/tcpip/stack/nic.go | 236 |
1 files changed, 134 insertions, 102 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index de88c0bfa..79556a36f 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -35,24 +35,21 @@ type NIC struct { linkEP LinkEndpoint context NICContext - mu sync.RWMutex - spoofing bool - promiscuous bool - primary map[tcpip.NetworkProtocolNumber][]*referencedNetworkEndpoint - endpoints map[NetworkEndpointID]*referencedNetworkEndpoint - addressRanges []tcpip.Subnet - mcastJoins map[NetworkEndpointID]int32 - // packetEPs is protected by mu, but the contained PacketEndpoint - // values are not. - packetEPs map[tcpip.NetworkProtocolNumber][]PacketEndpoint - stats NICStats - // ndp is the NDP related state for NIC. - // - // Note, read and write operations on ndp require that the NIC is - // appropriately locked. - ndp ndpState + mu struct { + sync.RWMutex + spoofing bool + promiscuous bool + primary map[tcpip.NetworkProtocolNumber][]*referencedNetworkEndpoint + endpoints map[NetworkEndpointID]*referencedNetworkEndpoint + addressRanges []tcpip.Subnet + mcastJoins map[NetworkEndpointID]int32 + // packetEPs is protected by mu, but the contained PacketEndpoint + // values are not. + packetEPs map[tcpip.NetworkProtocolNumber][]PacketEndpoint + ndp ndpState + } } // NICStats includes transmitted and received stats. @@ -97,15 +94,11 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC // of IPv6 is supported on this endpoint's LinkEndpoint. nic := &NIC{ - stack: stack, - id: id, - name: name, - linkEP: ep, - context: ctx, - primary: make(map[tcpip.NetworkProtocolNumber][]*referencedNetworkEndpoint), - endpoints: make(map[NetworkEndpointID]*referencedNetworkEndpoint), - mcastJoins: make(map[NetworkEndpointID]int32), - packetEPs: make(map[tcpip.NetworkProtocolNumber][]PacketEndpoint), + stack: stack, + id: id, + name: name, + linkEP: ep, + context: ctx, stats: NICStats{ Tx: DirectionStats{ Packets: &tcpip.StatCounter{}, @@ -116,22 +109,26 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC Bytes: &tcpip.StatCounter{}, }, }, - ndp: ndpState{ - configs: stack.ndpConfigs, - dad: make(map[tcpip.Address]dadState), - defaultRouters: make(map[tcpip.Address]defaultRouterState), - onLinkPrefixes: make(map[tcpip.Subnet]onLinkPrefixState), - autoGenAddresses: make(map[tcpip.Address]autoGenAddressState), - }, } - nic.ndp.nic = nic + nic.mu.primary = make(map[tcpip.NetworkProtocolNumber][]*referencedNetworkEndpoint) + nic.mu.endpoints = make(map[NetworkEndpointID]*referencedNetworkEndpoint) + nic.mu.mcastJoins = make(map[NetworkEndpointID]int32) + nic.mu.packetEPs = make(map[tcpip.NetworkProtocolNumber][]PacketEndpoint) + nic.mu.ndp = ndpState{ + nic: nic, + configs: stack.ndpConfigs, + dad: make(map[tcpip.Address]dadState), + defaultRouters: make(map[tcpip.Address]defaultRouterState), + onLinkPrefixes: make(map[tcpip.Subnet]onLinkPrefixState), + autoGenAddresses: make(map[tcpip.Address]autoGenAddressState), + } // Register supported packet endpoint protocols. for _, netProto := range header.Ethertypes { - nic.packetEPs[netProto] = []PacketEndpoint{} + nic.mu.packetEPs[netProto] = []PacketEndpoint{} } for _, netProto := range stack.networkProtocols { - nic.packetEPs[netProto.Number()] = []PacketEndpoint{} + nic.mu.packetEPs[netProto.Number()] = []PacketEndpoint{} } return nic @@ -215,7 +212,7 @@ func (n *NIC) enable() *tcpip.Error { // and default routers). Therefore, soliciting RAs from other routers on // a link is unnecessary for routers. if !n.stack.forwarding { - n.ndp.startSolicitingRouters() + n.mu.ndp.startSolicitingRouters() } return nil @@ -230,8 +227,8 @@ func (n *NIC) becomeIPv6Router() { n.mu.Lock() defer n.mu.Unlock() - n.ndp.cleanupHostOnlyState() - n.ndp.stopSolicitingRouters() + n.mu.ndp.cleanupHostOnlyState() + n.mu.ndp.stopSolicitingRouters() } // becomeIPv6Host transitions n into an IPv6 host. @@ -242,7 +239,7 @@ func (n *NIC) becomeIPv6Host() { n.mu.Lock() defer n.mu.Unlock() - n.ndp.startSolicitingRouters() + n.mu.ndp.startSolicitingRouters() } // attachLinkEndpoint attaches the NIC to the endpoint, which will enable it @@ -254,13 +251,13 @@ func (n *NIC) attachLinkEndpoint() { // setPromiscuousMode enables or disables promiscuous mode. func (n *NIC) setPromiscuousMode(enable bool) { n.mu.Lock() - n.promiscuous = enable + n.mu.promiscuous = enable n.mu.Unlock() } func (n *NIC) isPromiscuousMode() bool { n.mu.RLock() - rv := n.promiscuous + rv := n.mu.promiscuous n.mu.RUnlock() return rv } @@ -272,7 +269,7 @@ func (n *NIC) isLoopback() bool { // setSpoofing enables or disables address spoofing. func (n *NIC) setSpoofing(enable bool) { n.mu.Lock() - n.spoofing = enable + n.mu.spoofing = enable n.mu.Unlock() } @@ -291,8 +288,8 @@ func (n *NIC) primaryEndpoint(protocol tcpip.NetworkProtocolNumber, remoteAddr t defer n.mu.RUnlock() var deprecatedEndpoint *referencedNetworkEndpoint - for _, r := range n.primary[protocol] { - if !r.isValidForOutgoing() { + for _, r := range n.mu.primary[protocol] { + if !r.isValidForOutgoingRLocked() { continue } @@ -342,7 +339,7 @@ func (n *NIC) primaryIPv6Endpoint(remoteAddr tcpip.Address) *referencedNetworkEn n.mu.RLock() defer n.mu.RUnlock() - primaryAddrs := n.primary[header.IPv6ProtocolNumber] + primaryAddrs := n.mu.primary[header.IPv6ProtocolNumber] if len(primaryAddrs) == 0 { return nil @@ -425,7 +422,7 @@ func (n *NIC) primaryIPv6Endpoint(remoteAddr tcpip.Address) *referencedNetworkEn // hasPermanentAddrLocked returns true if n has a permanent (including currently // tentative) address, addr. func (n *NIC) hasPermanentAddrLocked(addr tcpip.Address) bool { - ref, ok := n.endpoints[NetworkEndpointID{addr}] + ref, ok := n.mu.endpoints[NetworkEndpointID{addr}] if !ok { return false @@ -436,24 +433,54 @@ func (n *NIC) hasPermanentAddrLocked(addr tcpip.Address) bool { return kind == permanent || kind == permanentTentative } +type getRefBehaviour int + +const ( + // spoofing indicates that the NIC's spoofing flag should be observed when + // getting a NIC's referenced network endpoint. + spoofing getRefBehaviour = iota + + // promiscuous indicates that the NIC's promiscuous flag should be observed + // when getting a NIC's referenced network endpoint. + promiscuous + + // forceSpoofing indicates that the NIC should be assumed to be spoofing, + // regardless of what the NIC's spoofing flag is when getting a NIC's + // referenced network endpoint. + forceSpoofing +) + func (n *NIC) getRef(protocol tcpip.NetworkProtocolNumber, dst tcpip.Address) *referencedNetworkEndpoint { - return n.getRefOrCreateTemp(protocol, dst, CanBePrimaryEndpoint, n.promiscuous) + return n.getRefOrCreateTemp(protocol, dst, CanBePrimaryEndpoint, promiscuous) } // findEndpoint finds the endpoint, if any, with the given address. func (n *NIC) findEndpoint(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior) *referencedNetworkEndpoint { - return n.getRefOrCreateTemp(protocol, address, peb, n.spoofing) + return n.getRefOrCreateTemp(protocol, address, peb, spoofing) } // getRefEpOrCreateTemp returns the referenced network endpoint for the given -// protocol and address. If none exists a temporary one may be created if -// we are in promiscuous mode or spoofing. -func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior, spoofingOrPromiscuous bool) *referencedNetworkEndpoint { +// protocol and address. +// +// If none exists a temporary one may be created if we are in promiscuous mode +// or spoofing. Promiscuous mode will only be checked if promiscuous is true. +// Similarly, spoofing will only be checked if spoofing is true. +func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address tcpip.Address, peb PrimaryEndpointBehavior, tempRef getRefBehaviour) *referencedNetworkEndpoint { id := NetworkEndpointID{address} n.mu.RLock() - if ref, ok := n.endpoints[id]; ok { + var spoofingOrPromiscuous bool + switch tempRef { + case spoofing: + spoofingOrPromiscuous = n.mu.spoofing + case promiscuous: + spoofingOrPromiscuous = n.mu.promiscuous + case forceSpoofing: + spoofingOrPromiscuous = true + } + + if ref, ok := n.mu.endpoints[id]; ok { // An endpoint with this id exists, check if it can be used and return it. switch ref.getKind() { case permanentExpired: @@ -474,7 +501,7 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t // the caller or if the address is found in the NIC's subnets. createTempEP := spoofingOrPromiscuous if !createTempEP { - for _, sn := range n.addressRanges { + for _, sn := range n.mu.addressRanges { // Skip the subnet address. if address == sn.ID() { continue @@ -502,7 +529,7 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t // endpoint, create a new "temporary" endpoint. It will only exist while // there's a route through it. n.mu.Lock() - if ref, ok := n.endpoints[id]; ok { + if ref, ok := n.mu.endpoints[id]; ok { // No need to check the type as we are ok with expired endpoints at this // point. if ref.tryIncRef() { @@ -543,7 +570,7 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar // Sanity check. id := NetworkEndpointID{LocalAddress: protocolAddress.AddressWithPrefix.Address} - if ref, ok := n.endpoints[id]; ok { + if ref, ok := n.mu.endpoints[id]; ok { // Endpoint already exists. if kind != permanent { return nil, tcpip.ErrDuplicateAddress @@ -562,7 +589,7 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar ref.deprecated = deprecated ref.configType = configType - refs := n.primary[ref.protocol] + refs := n.mu.primary[ref.protocol] for i, r := range refs { if r == ref { switch peb { @@ -572,9 +599,9 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar if i == 0 { return ref, nil } - n.primary[r.protocol] = append(refs[:i], refs[i+1:]...) + n.mu.primary[r.protocol] = append(refs[:i], refs[i+1:]...) case NeverPrimaryEndpoint: - n.primary[r.protocol] = append(refs[:i], refs[i+1:]...) + n.mu.primary[r.protocol] = append(refs[:i], refs[i+1:]...) return ref, nil } } @@ -637,13 +664,13 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar } } - n.endpoints[id] = ref + n.mu.endpoints[id] = ref n.insertPrimaryEndpointLocked(ref, peb) // If we are adding a tentative IPv6 address, start DAD. if isIPv6Unicast && kind == permanentTentative { - if err := n.ndp.startDuplicateAddressDetection(protocolAddress.AddressWithPrefix.Address, ref); err != nil { + if err := n.mu.ndp.startDuplicateAddressDetection(protocolAddress.AddressWithPrefix.Address, ref); err != nil { return nil, err } } @@ -668,8 +695,8 @@ func (n *NIC) AllAddresses() []tcpip.ProtocolAddress { n.mu.RLock() defer n.mu.RUnlock() - addrs := make([]tcpip.ProtocolAddress, 0, len(n.endpoints)) - for nid, ref := range n.endpoints { + addrs := make([]tcpip.ProtocolAddress, 0, len(n.mu.endpoints)) + for nid, ref := range n.mu.endpoints { // Don't include tentative, expired or temporary endpoints to // avoid confusion and prevent the caller from using those. switch ref.getKind() { @@ -695,7 +722,7 @@ func (n *NIC) PrimaryAddresses() []tcpip.ProtocolAddress { defer n.mu.RUnlock() var addrs []tcpip.ProtocolAddress - for proto, list := range n.primary { + for proto, list := range n.mu.primary { for _, ref := range list { // Don't include tentative, expired or tempory endpoints // to avoid confusion and prevent the caller from using @@ -726,7 +753,7 @@ func (n *NIC) primaryAddress(proto tcpip.NetworkProtocolNumber) tcpip.AddressWit n.mu.RLock() defer n.mu.RUnlock() - list, ok := n.primary[proto] + list, ok := n.mu.primary[proto] if !ok { return tcpip.AddressWithPrefix{} } @@ -769,7 +796,7 @@ func (n *NIC) primaryAddress(proto tcpip.NetworkProtocolNumber) tcpip.AddressWit // address. func (n *NIC) AddAddressRange(protocol tcpip.NetworkProtocolNumber, subnet tcpip.Subnet) { n.mu.Lock() - n.addressRanges = append(n.addressRanges, subnet) + n.mu.addressRanges = append(n.mu.addressRanges, subnet) n.mu.Unlock() } @@ -778,13 +805,13 @@ func (n *NIC) RemoveAddressRange(subnet tcpip.Subnet) { n.mu.Lock() // Use the same underlying array. - tmp := n.addressRanges[:0] - for _, sub := range n.addressRanges { + tmp := n.mu.addressRanges[:0] + for _, sub := range n.mu.addressRanges { if sub != subnet { tmp = append(tmp, sub) } } - n.addressRanges = tmp + n.mu.addressRanges = tmp n.mu.Unlock() } @@ -793,8 +820,8 @@ func (n *NIC) RemoveAddressRange(subnet tcpip.Subnet) { func (n *NIC) AddressRanges() []tcpip.Subnet { n.mu.RLock() defer n.mu.RUnlock() - sns := make([]tcpip.Subnet, 0, len(n.addressRanges)+len(n.endpoints)) - for nid := range n.endpoints { + sns := make([]tcpip.Subnet, 0, len(n.mu.addressRanges)+len(n.mu.endpoints)) + for nid := range n.mu.endpoints { sn, err := tcpip.NewSubnet(nid.LocalAddress, tcpip.AddressMask(strings.Repeat("\xff", len(nid.LocalAddress)))) if err != nil { // This should never happen as the mask has been carefully crafted to @@ -803,7 +830,7 @@ func (n *NIC) AddressRanges() []tcpip.Subnet { } sns = append(sns, sn) } - return append(sns, n.addressRanges...) + return append(sns, n.mu.addressRanges...) } // insertPrimaryEndpointLocked adds r to n's primary endpoint list as required @@ -813,9 +840,9 @@ func (n *NIC) AddressRanges() []tcpip.Subnet { func (n *NIC) insertPrimaryEndpointLocked(r *referencedNetworkEndpoint, peb PrimaryEndpointBehavior) { switch peb { case CanBePrimaryEndpoint: - n.primary[r.protocol] = append(n.primary[r.protocol], r) + n.mu.primary[r.protocol] = append(n.mu.primary[r.protocol], r) case FirstPrimaryEndpoint: - n.primary[r.protocol] = append([]*referencedNetworkEndpoint{r}, n.primary[r.protocol]...) + n.mu.primary[r.protocol] = append([]*referencedNetworkEndpoint{r}, n.mu.primary[r.protocol]...) } } @@ -827,7 +854,7 @@ func (n *NIC) removeEndpointLocked(r *referencedNetworkEndpoint) { // and was waiting (on the lock) to be removed and 2) the same address was // re-added in the meantime by removing this endpoint from the list and // adding a new one. - if n.endpoints[id] != r { + if n.mu.endpoints[id] != r { return } @@ -835,11 +862,11 @@ func (n *NIC) removeEndpointLocked(r *referencedNetworkEndpoint) { panic("Reference count dropped to zero before being removed") } - delete(n.endpoints, id) - refs := n.primary[r.protocol] + delete(n.mu.endpoints, id) + refs := n.mu.primary[r.protocol] for i, ref := range refs { if ref == r { - n.primary[r.protocol] = append(refs[:i], refs[i+1:]...) + n.mu.primary[r.protocol] = append(refs[:i], refs[i+1:]...) break } } @@ -854,7 +881,7 @@ func (n *NIC) removeEndpoint(r *referencedNetworkEndpoint) { } func (n *NIC) removePermanentAddressLocked(addr tcpip.Address) *tcpip.Error { - r, ok := n.endpoints[NetworkEndpointID{addr}] + r, ok := n.mu.endpoints[NetworkEndpointID{addr}] if !ok { return tcpip.ErrBadLocalAddress } @@ -870,13 +897,13 @@ func (n *NIC) removePermanentAddressLocked(addr tcpip.Address) *tcpip.Error { // If we are removing a tentative IPv6 unicast address, stop // DAD. if kind == permanentTentative { - n.ndp.stopDuplicateAddressDetection(addr) + n.mu.ndp.stopDuplicateAddressDetection(addr) } // If we are removing an address generated via SLAAC, cleanup // its SLAAC resources and notify the integrator. if r.configType == slaac { - n.ndp.cleanupAutoGenAddrResourcesAndNotify(addr) + n.mu.ndp.cleanupAutoGenAddrResourcesAndNotify(addr) } } @@ -926,7 +953,7 @@ func (n *NIC) joinGroupLocked(protocol tcpip.NetworkProtocolNumber, addr tcpip.A // outlined in RFC 3810 section 5. id := NetworkEndpointID{addr} - joins := n.mcastJoins[id] + joins := n.mu.mcastJoins[id] if joins == 0 { netProto, ok := n.stack.networkProtocols[protocol] if !ok { @@ -942,7 +969,7 @@ func (n *NIC) joinGroupLocked(protocol tcpip.NetworkProtocolNumber, addr tcpip.A return err } } - n.mcastJoins[id] = joins + 1 + n.mu.mcastJoins[id] = joins + 1 return nil } @@ -960,7 +987,7 @@ func (n *NIC) leaveGroup(addr tcpip.Address) *tcpip.Error { // before leaveGroupLocked is called. func (n *NIC) leaveGroupLocked(addr tcpip.Address) *tcpip.Error { id := NetworkEndpointID{addr} - joins := n.mcastJoins[id] + joins := n.mu.mcastJoins[id] switch joins { case 0: // There are no joins with this address on this NIC. @@ -971,7 +998,7 @@ func (n *NIC) leaveGroupLocked(addr tcpip.Address) *tcpip.Error { return err } } - n.mcastJoins[id] = joins - 1 + n.mu.mcastJoins[id] = joins - 1 return nil } @@ -1006,12 +1033,12 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.Link // Are any packet sockets listening for this network protocol? n.mu.RLock() - packetEPs := n.packetEPs[protocol] + packetEPs := n.mu.packetEPs[protocol] // Check whether there are packet sockets listening for every protocol. // If we received a packet with protocol EthernetProtocolAll, then the // previous for loop will have handled it. if protocol != header.EthernetProtocolAll { - packetEPs = append(packetEPs, n.packetEPs[header.EthernetProtocolAll]...) + packetEPs = append(packetEPs, n.mu.packetEPs[header.EthernetProtocolAll]...) } n.mu.RUnlock() for _, ep := range packetEPs { @@ -1060,8 +1087,8 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.Link // Found a NIC. n := r.ref.nic n.mu.RLock() - ref, ok := n.endpoints[NetworkEndpointID{dst}] - ok = ok && ref.isValidForOutgoing() && ref.tryIncRef() + ref, ok := n.mu.endpoints[NetworkEndpointID{dst}] + ok = ok && ref.isValidForOutgoingRLocked() && ref.tryIncRef() n.mu.RUnlock() if ok { r.RemoteAddress = src @@ -1181,7 +1208,7 @@ func (n *NIC) Stack() *Stack { // false. It will only return true if the address is associated with the NIC // AND it is tentative. func (n *NIC) isAddrTentative(addr tcpip.Address) bool { - ref, ok := n.endpoints[NetworkEndpointID{addr}] + ref, ok := n.mu.endpoints[NetworkEndpointID{addr}] if !ok { return false } @@ -1197,7 +1224,7 @@ func (n *NIC) dupTentativeAddrDetected(addr tcpip.Address) *tcpip.Error { n.mu.Lock() defer n.mu.Unlock() - ref, ok := n.endpoints[NetworkEndpointID{addr}] + ref, ok := n.mu.endpoints[NetworkEndpointID{addr}] if !ok { return tcpip.ErrBadAddress } @@ -1217,7 +1244,7 @@ func (n *NIC) setNDPConfigs(c NDPConfigurations) { c.validate() n.mu.Lock() - n.ndp.configs = c + n.mu.ndp.configs = c n.mu.Unlock() } @@ -1226,7 +1253,7 @@ func (n *NIC) handleNDPRA(ip tcpip.Address, ra header.NDPRouterAdvert) { n.mu.Lock() defer n.mu.Unlock() - n.ndp.handleRA(ip, ra) + n.mu.ndp.handleRA(ip, ra) } type networkEndpointKind int32 @@ -1268,11 +1295,11 @@ func (n *NIC) registerPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep Pa n.mu.Lock() defer n.mu.Unlock() - eps, ok := n.packetEPs[netProto] + eps, ok := n.mu.packetEPs[netProto] if !ok { return tcpip.ErrNotSupported } - n.packetEPs[netProto] = append(eps, ep) + n.mu.packetEPs[netProto] = append(eps, ep) return nil } @@ -1281,14 +1308,14 @@ func (n *NIC) unregisterPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep n.mu.Lock() defer n.mu.Unlock() - eps, ok := n.packetEPs[netProto] + eps, ok := n.mu.packetEPs[netProto] if !ok { return } for i, epOther := range eps { if epOther == ep { - n.packetEPs[netProto] = append(eps[:i], eps[i+1:]...) + n.mu.packetEPs[netProto] = append(eps[:i], eps[i+1:]...) return } } @@ -1346,14 +1373,19 @@ func (r *referencedNetworkEndpoint) setKind(kind networkEndpointKind) { // packet. It requires the endpoint to not be marked expired (i.e., its address // has been removed), or the NIC to be in spoofing mode. func (r *referencedNetworkEndpoint) isValidForOutgoing() bool { - return r.getKind() != permanentExpired || r.nic.spoofing + r.nic.mu.RLock() + defer r.nic.mu.RUnlock() + + return r.isValidForOutgoingRLocked() } -// isValidForIncoming returns true if the endpoint can accept an incoming -// packet. It requires the endpoint to not be marked expired (i.e., its address -// has been removed), or the NIC to be in promiscuous mode. -func (r *referencedNetworkEndpoint) isValidForIncoming() bool { - return r.getKind() != permanentExpired || r.nic.promiscuous +// isValidForOutgoingRLocked 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), or the NIC to be in spoofing mode. +// +// r's NIC must be read locked. +func (r *referencedNetworkEndpoint) isValidForOutgoingRLocked() bool { + return r.getKind() != permanentExpired || r.nic.mu.spoofing } // decRef decrements the ref count and cleans up the endpoint once it reaches |