diff options
Diffstat (limited to 'pkg/tcpip/stack/nic.go')
-rw-r--r-- | pkg/tcpip/stack/nic.go | 596 |
1 files changed, 461 insertions, 135 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 43719085e..e8401c673 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -19,7 +19,6 @@ import ( "sync" "sync/atomic" - "gvisor.dev/gvisor/pkg/ilist" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" "gvisor.dev/gvisor/pkg/tcpip/header" @@ -34,17 +33,24 @@ type NIC struct { linkEP LinkEndpoint loopback bool - demux *transportDemuxer - mu sync.RWMutex spoofing bool promiscuous bool - primary map[tcpip.NetworkProtocolNumber]*ilist.List + 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 } // NICStats includes transmitted and received stats. @@ -78,17 +84,26 @@ const ( NeverPrimaryEndpoint ) +// newNIC returns a new NIC using the default NDP configurations from stack. func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, loopback bool) *NIC { - return &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. + + // TODO(b/143357959): RFC 8200 section 5 requires that IPv6 endpoints + // observe an MTU of at least 1280 bytes. Ensure that this requirement + // of IPv6 is supported on this endpoint's LinkEndpoint. + + nic := &NIC{ stack: stack, id: id, name: name, linkEP: ep, loopback: loopback, - demux: newTransportDemuxer(stack), - primary: make(map[tcpip.NetworkProtocolNumber]*ilist.List), + primary: make(map[tcpip.NetworkProtocolNumber][]*referencedNetworkEndpoint), endpoints: make(map[NetworkEndpointID]*referencedNetworkEndpoint), mcastJoins: make(map[NetworkEndpointID]int32), + packetEPs: make(map[tcpip.NetworkProtocolNumber][]PacketEndpoint), stats: NICStats{ Tx: DirectionStats{ Packets: &tcpip.StatCounter{}, @@ -99,7 +114,93 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, loopback 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 + + // Register supported packet endpoint protocols. + for _, netProto := range header.Ethertypes { + nic.packetEPs[netProto] = []PacketEndpoint{} + } + for _, netProto := range stack.networkProtocols { + nic.packetEPs[netProto.Number()] = []PacketEndpoint{} + } + + return nic +} + +// enable enables the NIC. enable will attach the link to its LinkEndpoint and +// join the IPv6 All-Nodes Multicast address (ff02::1). +func (n *NIC) enable() *tcpip.Error { + n.attachLinkEndpoint() + + // Create an endpoint to receive broadcast packets on this interface. + if _, ok := n.stack.networkProtocols[header.IPv4ProtocolNumber]; ok { + if err := n.AddAddress(tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: tcpip.AddressWithPrefix{header.IPv4Broadcast, 8 * header.IPv4AddressSize}, + }, NeverPrimaryEndpoint); err != nil { + return err + } + } + + // Join the IPv6 All-Nodes Multicast group if the stack is configured to + // use IPv6. This is required to ensure that this node properly receives + // and responds to the various NDP messages that are destined to the + // all-nodes multicast address. An example is the Neighbor Advertisement + // when we perform Duplicate Address Detection, or Router Advertisement + // when we do Router Discovery. See RFC 4862, section 5.4.2 and RFC 4861 + // section 4.2 for more information. + // + // Also auto-generate an IPv6 link-local address based on the NIC's + // link address if it is configured to do so. Note, each interface is + // required to have IPv6 link-local unicast address, as per RFC 4291 + // section 2.1. + _, ok := n.stack.networkProtocols[header.IPv6ProtocolNumber] + if !ok { + return nil + } + + n.mu.Lock() + defer n.mu.Unlock() + + if err := n.joinGroupLocked(header.IPv6ProtocolNumber, header.IPv6AllNodesMulticastAddress); err != nil { + return err + } + + if !n.stack.autoGenIPv6LinkLocal { + return nil } + + l2addr := n.linkEP.LinkAddress() + + // Only attempt to generate the link-local address if we have a + // valid MAC address. + // + // TODO(b/141011931): Validate a LinkEndpoint's link address + // (provided by LinkEndpoint.LinkAddress) before reaching this + // point. + if !header.IsValidUnicastEthernetAddress(l2addr) { + return nil + } + + addr := header.LinkLocalAddr(l2addr) + + _, err := n.addPermanentAddressLocked(tcpip.ProtocolAddress{ + Protocol: header.IPv6ProtocolNumber, + AddressWithPrefix: tcpip.AddressWithPrefix{ + Address: addr, + PrefixLen: header.IPv6LinkLocalPrefix.PrefixLen, + }, + }, CanBePrimaryEndpoint) + + return err } // attachLinkEndpoint attaches the NIC to the endpoint, which will enable it @@ -129,55 +230,13 @@ func (n *NIC) setSpoofing(enable bool) { n.mu.Unlock() } -func (n *NIC) getMainNICAddress(protocol tcpip.NetworkProtocolNumber) (tcpip.AddressWithPrefix, *tcpip.Error) { - n.mu.RLock() - defer n.mu.RUnlock() - - var r *referencedNetworkEndpoint - - // Check for a primary endpoint. - if list, ok := n.primary[protocol]; ok { - for e := list.Front(); e != nil; e = e.Next() { - ref := e.(*referencedNetworkEndpoint) - if ref.getKind() == permanent && ref.tryIncRef() { - r = ref - break - } - } - - } - - if r == nil { - return tcpip.AddressWithPrefix{}, tcpip.ErrNoLinkAddress - } - - addressWithPrefix := tcpip.AddressWithPrefix{ - Address: r.ep.ID().LocalAddress, - PrefixLen: r.ep.PrefixLen(), - } - r.decRef() - - return addressWithPrefix, nil -} - // primaryEndpoint returns the primary endpoint of n for the given network // protocol. func (n *NIC) primaryEndpoint(protocol tcpip.NetworkProtocolNumber) *referencedNetworkEndpoint { n.mu.RLock() defer n.mu.RUnlock() - list := n.primary[protocol] - if list == nil { - return nil - } - - for e := list.Front(); e != nil; e = e.Next() { - r := e.(*referencedNetworkEndpoint) - // TODO(crawshaw): allow broadcast address when SO_BROADCAST is set. - switch r.ep.ID().LocalAddress { - case header.IPv4Broadcast, header.IPv4Any: - continue - } + for _, r := range n.primary[protocol] { if r.isValidForOutgoing() && r.tryIncRef() { return r } @@ -186,6 +245,20 @@ func (n *NIC) primaryEndpoint(protocol tcpip.NetworkProtocolNumber) *referencedN return nil } +// 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}] + + if !ok { + return false + } + + kind := ref.getKind() + + return kind == permanent || kind == permanentTentative +} + func (n *NIC) getRef(protocol tcpip.NetworkProtocolNumber, dst tcpip.Address) *referencedNetworkEndpoint { return n.getRefOrCreateTemp(protocol, dst, CanBePrimaryEndpoint, n.promiscuous) } @@ -277,7 +350,7 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t Address: address, PrefixLen: netProto.DefaultPrefixLen(), }, - }, peb, temporary) + }, peb, temporary, static) n.mu.Unlock() return ref @@ -287,13 +360,35 @@ func (n *NIC) addPermanentAddressLocked(protocolAddress tcpip.ProtocolAddress, p id := NetworkEndpointID{protocolAddress.AddressWithPrefix.Address} if ref, ok := n.endpoints[id]; ok { switch ref.getKind() { - case permanent: + case permanentTentative, permanent: // The NIC already have a permanent endpoint with that address. return nil, tcpip.ErrDuplicateAddress case permanentExpired, temporary: - // Promote the endpoint to become permanent. + // Promote the endpoint to become permanent and respect + // the new peb. if ref.tryIncRef() { ref.setKind(permanent) + + refs := n.primary[ref.protocol] + for i, r := range refs { + if r == ref { + switch peb { + case CanBePrimaryEndpoint: + return ref, nil + case FirstPrimaryEndpoint: + if i == 0 { + return ref, nil + } + n.primary[r.protocol] = append(refs[:i], refs[i+1:]...) + case NeverPrimaryEndpoint: + n.primary[r.protocol] = append(refs[:i], refs[i+1:]...) + return ref, nil + } + } + } + + n.insertPrimaryEndpointLocked(ref, peb) + return ref, nil } // tryIncRef failing means the endpoint is scheduled to be removed once @@ -303,10 +398,13 @@ func (n *NIC) addPermanentAddressLocked(protocolAddress tcpip.ProtocolAddress, p n.removeEndpointLocked(ref) } } - return n.addAddressLocked(protocolAddress, peb, permanent) + + return n.addAddressLocked(protocolAddress, peb, permanent, static) } -func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior, kind networkEndpointKind) (*referencedNetworkEndpoint, *tcpip.Error) { +func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior, kind networkEndpointKind, configType networkEndpointConfigType) (*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 { @@ -324,12 +422,22 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar if err != nil { return nil, err } + + isIPv6Unicast := protocolAddress.Protocol == header.IPv6ProtocolNumber && header.IsV6UnicastAddress(protocolAddress.AddressWithPrefix.Address) + + // If the address is an IPv6 address and it is a permanent address, + // mark it as tentative so it goes through the DAD process. + if isIPv6Unicast && kind == permanent { + kind = permanentTentative + } + ref := &referencedNetworkEndpoint{ - refs: 1, - ep: ep, - nic: n, - protocol: protocolAddress.Protocol, - kind: kind, + refs: 1, + ep: ep, + nic: n, + protocol: protocolAddress.Protocol, + kind: kind, + configType: configType, } // Set up cache if link address resolution exists for this protocol. @@ -339,19 +447,24 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar } } + // If we are adding an IPv6 unicast address, join the solicited-node + // multicast address. + if isIPv6Unicast { + snmc := header.SolicitedNodeAddr(protocolAddress.AddressWithPrefix.Address) + if err := n.joinGroupLocked(protocolAddress.Protocol, snmc); err != nil { + return nil, err + } + } + n.endpoints[id] = ref - l, ok := n.primary[protocolAddress.Protocol] - if !ok { - l = &ilist.List{} - n.primary[protocolAddress.Protocol] = l - } + n.insertPrimaryEndpointLocked(ref, peb) - switch peb { - case CanBePrimaryEndpoint: - l.PushBack(ref) - case FirstPrimaryEndpoint: - l.PushFront(ref) + // 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 { + return nil, err + } } return ref, nil @@ -368,16 +481,20 @@ func (n *NIC) AddAddress(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpo return err } -// Addresses returns the addresses associated with this NIC. -func (n *NIC) Addresses() []tcpip.ProtocolAddress { +// AllAddresses returns all addresses (primary and non-primary) associated with +// this NIC. +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 { - // Don't include expired or tempory endpoints to avoid confusion and - // prevent the caller from using those. + // Don't include tentative, expired or temporary endpoints to + // avoid confusion and prevent the caller from using those. switch ref.getKind() { - case permanentExpired, temporary: + case permanentTentative, permanentExpired, temporary: + // TODO(b/140898488): Should tentative addresses be + // returned? continue } addrs = append(addrs, tcpip.ProtocolAddress{ @@ -391,6 +508,34 @@ func (n *NIC) Addresses() []tcpip.ProtocolAddress { return addrs } +// PrimaryAddresses returns the primary addresses associated with this NIC. +func (n *NIC) PrimaryAddresses() []tcpip.ProtocolAddress { + n.mu.RLock() + defer n.mu.RUnlock() + + var addrs []tcpip.ProtocolAddress + for proto, list := range n.primary { + for _, ref := range list { + // Don't include tentative, expired or tempory endpoints + // to avoid confusion and prevent the caller from using + // those. + switch ref.getKind() { + case permanentTentative, permanentExpired, temporary: + continue + } + + addrs = append(addrs, tcpip.ProtocolAddress{ + Protocol: proto, + AddressWithPrefix: tcpip.AddressWithPrefix{ + Address: ref.ep.ID().LocalAddress, + PrefixLen: ref.ep.PrefixLen(), + }, + }) + } + } + return addrs +} + // AddAddressRange adds a range of addresses to n, so that it starts accepting // packets targeted at the given addresses and network protocol. The range is // given by a subnet address, and all addresses contained in the subnet are @@ -435,6 +580,19 @@ func (n *NIC) AddressRanges() []tcpip.Subnet { return append(sns, n.addressRanges...) } +// insertPrimaryEndpointLocked adds r to n's primary endpoint list as required +// by peb. +// +// n MUST be locked. +func (n *NIC) insertPrimaryEndpointLocked(r *referencedNetworkEndpoint, peb PrimaryEndpointBehavior) { + switch peb { + case CanBePrimaryEndpoint: + n.primary[r.protocol] = append(n.primary[r.protocol], r) + case FirstPrimaryEndpoint: + n.primary[r.protocol] = append([]*referencedNetworkEndpoint{r}, n.primary[r.protocol]...) + } +} + func (n *NIC) removeEndpointLocked(r *referencedNetworkEndpoint) { id := *r.ep.ID() @@ -452,9 +610,12 @@ func (n *NIC) removeEndpointLocked(r *referencedNetworkEndpoint) { } delete(n.endpoints, id) - wasInList := r.Next() != nil || r.Prev() != nil || r == n.primary[r.protocol].Front() - if wasInList { - n.primary[r.protocol].Remove(r) + refs := n.primary[r.protocol] + for i, ref := range refs { + if ref == r { + n.primary[r.protocol] = append(refs[:i], refs[i+1:]...) + break + } } r.ep.Close() @@ -467,13 +628,48 @@ func (n *NIC) removeEndpoint(r *referencedNetworkEndpoint) { } func (n *NIC) removePermanentAddressLocked(addr tcpip.Address) *tcpip.Error { - r := n.endpoints[NetworkEndpointID{addr}] - if r == nil || r.getKind() != permanent { + r, ok := n.endpoints[NetworkEndpointID{addr}] + if !ok { + return tcpip.ErrBadLocalAddress + } + + kind := r.getKind() + if kind != permanent && kind != permanentTentative { return tcpip.ErrBadLocalAddress } + isIPv6Unicast := r.protocol == header.IPv6ProtocolNumber && header.IsV6UnicastAddress(addr) + + if isIPv6Unicast { + // If we are removing a tentative IPv6 unicast address, stop + // DAD. + if kind == permanentTentative { + n.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) + } + } + r.setKind(permanentExpired) - r.decRefLocked() + if !r.decRefLocked() { + // The endpoint still has references to it. + return nil + } + + // At this point the endpoint is deleted. + + // If we are removing an IPv6 unicast address, leave the solicited-node + // multicast address. + if isIPv6Unicast { + snmc := header.SolicitedNodeAddr(addr) + if err := n.leaveGroupLocked(snmc); err != nil { + return err + } + } return nil } @@ -491,6 +687,18 @@ func (n *NIC) joinGroup(protocol tcpip.NetworkProtocolNumber, addr tcpip.Address n.mu.Lock() defer n.mu.Unlock() + return n.joinGroupLocked(protocol, addr) +} + +// joinGroupLocked adds a new endpoint for the given multicast address, if none +// exists yet. Otherwise it just increments its count. n MUST be locked before +// joinGroupLocked is called. +func (n *NIC) joinGroupLocked(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 + // outlined in RFC 3810 section 5. + id := NetworkEndpointID{addr} joins := n.mcastJoins[id] if joins == 0 { @@ -518,6 +726,13 @@ func (n *NIC) leaveGroup(addr tcpip.Address) *tcpip.Error { n.mu.Lock() defer n.mu.Unlock() + return n.leaveGroupLocked(addr) +} + +// leaveGroupLocked decrements the count for the given multicast address, and +// when it reaches zero removes the endpoint for this address. n MUST be locked +// before leaveGroupLocked is called. +func (n *NIC) leaveGroupLocked(addr tcpip.Address) *tcpip.Error { id := NetworkEndpointID{addr} joins := n.mcastJoins[id] switch joins { @@ -534,10 +749,10 @@ func (n *NIC) leaveGroup(addr tcpip.Address) *tcpip.Error { return nil } -func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address, localLinkAddr, remotelinkAddr tcpip.LinkAddress, ref *referencedNetworkEndpoint, vv buffer.VectorisedView) { +func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address, localLinkAddr, remotelinkAddr tcpip.LinkAddress, ref *referencedNetworkEndpoint, pkt tcpip.PacketBuffer) { r := makeRoute(protocol, dst, src, localLinkAddr, ref, false /* handleLocal */, false /* multicastLoop */) r.RemoteLinkAddress = remotelinkAddr - ref.ep.HandlePacket(&r, vv) + ref.ep.HandlePacket(&r, pkt) ref.decRef() } @@ -547,9 +762,9 @@ func handlePacket(protocol tcpip.NetworkProtocolNumber, dst, src tcpip.Address, // 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(linkEP LinkEndpoint, remote, _ tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView) { +func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, pkt tcpip.PacketBuffer) { n.stats.Rx.Packets.Increment() - n.stats.Rx.Bytes.IncrementBy(uint64(vv.Size())) + n.stats.Rx.Bytes.IncrementBy(uint64(pkt.Data.Size())) netProto, ok := n.stack.networkProtocols[protocol] if !ok { @@ -557,36 +772,39 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, _ tcpip.LinkAddr return } + // If no local link layer address is provided, assume it was sent + // directly to this NIC. + if local == "" { + local = n.linkEP.LinkAddress() + } + + // Are any packet sockets listening for this network protocol? + n.mu.RLock() + packetEPs := n.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]...) + } + n.mu.RUnlock() + for _, ep := range packetEPs { + ep.HandlePacket(n.id, local, protocol, pkt.Clone()) + } + if netProto.Number() == header.IPv4ProtocolNumber || netProto.Number() == header.IPv6ProtocolNumber { n.stack.stats.IP.PacketsReceived.Increment() } - if len(vv.First()) < netProto.MinimumPacketSize() { + if len(pkt.Data.First()) < netProto.MinimumPacketSize() { n.stack.stats.MalformedRcvdPackets.Increment() return } - src, dst := netProto.ParseAddresses(vv.First()) - - n.stack.AddLinkAddress(n.id, src, remote) - - // If the packet is destined to the IPv4 Broadcast address, then make a - // route to each IPv4 network endpoint and let each endpoint handle the - // packet. - if dst == header.IPv4Broadcast { - // n.endpoints is mutex protected so acquire lock. - n.mu.RLock() - for _, ref := range n.endpoints { - if ref.isValidForIncoming() && ref.protocol == header.IPv4ProtocolNumber && ref.tryIncRef() { - handlePacket(protocol, dst, src, linkEP.LinkAddress(), remote, ref, vv) - } - } - n.mu.RUnlock() - return - } + src, dst := netProto.ParseAddresses(pkt.Data.First()) if ref := n.getRef(protocol, dst); ref != nil { - handlePacket(protocol, dst, src, linkEP.LinkAddress(), remote, ref, vv) + handlePacket(protocol, dst, src, linkEP.LinkAddress(), remote, ref, pkt) return } @@ -614,31 +832,34 @@ func (n *NIC) DeliverNetworkPacket(linkEP LinkEndpoint, remote, _ tcpip.LinkAddr if ok { r.RemoteAddress = src // TODO(b/123449044): Update the source NIC as well. - ref.ep.HandlePacket(&r, vv) + ref.ep.HandlePacket(&r, pkt) ref.decRef() } else { // n doesn't have a destination endpoint. // Send the packet out of n. - hdr := buffer.NewPrependableFromView(vv.First()) - vv.RemoveFirst() + pkt.Header = buffer.NewPrependableFromView(pkt.Data.First()) + pkt.Data.RemoveFirst() // TODO(b/128629022): use route.WritePacket. - if err := n.linkEP.WritePacket(&r, nil /* gso */, hdr, vv, protocol); err != nil { + if err := n.linkEP.WritePacket(&r, nil /* gso */, protocol, pkt); err != nil { r.Stats().IP.OutgoingPacketErrors.Increment() } else { n.stats.Tx.Packets.Increment() - n.stats.Tx.Bytes.IncrementBy(uint64(hdr.UsedLength() + vv.Size())) + n.stats.Tx.Bytes.IncrementBy(uint64(pkt.Header.UsedLength() + pkt.Data.Size())) } } return } - n.stack.stats.IP.InvalidAddressesReceived.Increment() + // If a packet socket handled the packet, don't treat it as invalid. + if len(packetEPs) == 0 { + n.stack.stats.IP.InvalidAddressesReceived.Increment() + } } // DeliverTransportPacket delivers the packets to the appropriate transport // protocol endpoint. -func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, netHeader buffer.View, vv buffer.VectorisedView) { +func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, pkt tcpip.PacketBuffer) { state, ok := n.stack.transportProtocols[protocol] if !ok { n.stack.stats.UnknownProtocolRcvdPackets.Increment() @@ -650,46 +871,41 @@ func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolN // Raw socket packets are delivered based solely on the transport // protocol number. We do not inspect the payload to ensure it's // validly formed. - if !n.demux.deliverRawPacket(r, protocol, netHeader, vv) { - n.stack.demux.deliverRawPacket(r, protocol, netHeader, vv) - } + n.stack.demux.deliverRawPacket(r, protocol, pkt) - if len(vv.First()) < transProto.MinimumPacketSize() { + if len(pkt.Data.First()) < transProto.MinimumPacketSize() { n.stack.stats.MalformedRcvdPackets.Increment() return } - srcPort, dstPort, err := transProto.ParsePorts(vv.First()) + srcPort, dstPort, err := transProto.ParsePorts(pkt.Data.First()) if err != nil { n.stack.stats.MalformedRcvdPackets.Increment() return } id := TransportEndpointID{dstPort, r.LocalAddress, srcPort, r.RemoteAddress} - if n.demux.deliverPacket(r, protocol, netHeader, vv, id) { - return - } - if n.stack.demux.deliverPacket(r, protocol, netHeader, vv, id) { + if n.stack.demux.deliverPacket(r, protocol, pkt, id) { return } // Try to deliver to per-stack default handler. if state.defaultHandler != nil { - if state.defaultHandler(r, id, netHeader, vv) { + if state.defaultHandler(r, id, pkt) { return } } // We could not find an appropriate destination for this packet, so // deliver it to the global handler. - if !transProto.HandleUnknownDestinationPacket(r, id, netHeader, vv) { + if !transProto.HandleUnknownDestinationPacket(r, id, pkt) { n.stack.stats.MalformedRcvdPackets.Increment() } } // DeliverTransportControlPacket delivers control packets to the appropriate // transport protocol endpoint. -func (n *NIC) DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, vv buffer.VectorisedView) { +func (n *NIC) DeliverTransportControlPacket(local, remote tcpip.Address, net tcpip.NetworkProtocolNumber, trans tcpip.TransportProtocolNumber, typ ControlType, extra uint32, pkt tcpip.PacketBuffer) { state, ok := n.stack.transportProtocols[trans] if !ok { return @@ -700,20 +916,17 @@ func (n *NIC) DeliverTransportControlPacket(local, remote tcpip.Address, net tcp // ICMPv4 only guarantees that 8 bytes of the transport protocol will // be present in the payload. We know that the ports are within the // first 8 bytes for all known transport protocols. - if len(vv.First()) < 8 { + if len(pkt.Data.First()) < 8 { return } - srcPort, dstPort, err := transProto.ParsePorts(vv.First()) + srcPort, dstPort, err := transProto.ParsePorts(pkt.Data.First()) if err != nil { return } id := TransportEndpointID{srcPort, local, dstPort, remote} - if n.demux.deliverControlPacket(net, trans, typ, extra, vv, id) { - return - } - if n.stack.demux.deliverControlPacket(net, trans, typ, extra, vv, id) { + if n.stack.demux.deliverControlPacket(n, net, trans, typ, extra, pkt, id) { return } } @@ -728,16 +941,80 @@ func (n *NIC) Stack() *Stack { return n.stack } +// isAddrTentative returns true if addr is tentative on n. +// +// Note that if addr is not associated with n, then this function will return +// 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}] + if !ok { + return false + } + + return ref.getKind() == permanentTentative +} + +// dupTentativeAddrDetected attempts to inform n that a tentative addr +// is a duplicate on a link. +// +// dupTentativeAddrDetected will delete the tentative address if it exists. +func (n *NIC) dupTentativeAddrDetected(addr tcpip.Address) *tcpip.Error { + n.mu.Lock() + defer n.mu.Unlock() + + ref, ok := n.endpoints[NetworkEndpointID{addr}] + if !ok { + return tcpip.ErrBadAddress + } + + if ref.getKind() != permanentTentative { + return tcpip.ErrInvalidEndpointState + } + + return n.removePermanentAddressLocked(addr) +} + +// setNDPConfigs sets the NDP configurations for n. +// +// Note, if c contains invalid NDP configuration values, it will be fixed to +// use default values for the erroneous values. +func (n *NIC) setNDPConfigs(c NDPConfigurations) { + c.validate() + + n.mu.Lock() + n.ndp.configs = c + n.mu.Unlock() +} + +// handleNDPRA handles an NDP Router Advertisement message that arrived on n. +func (n *NIC) handleNDPRA(ip tcpip.Address, ra header.NDPRouterAdvert) { + n.mu.Lock() + defer n.mu.Unlock() + + n.ndp.handleRA(ip, ra) +} + type networkEndpointKind int32 const ( + // A permanentTentative endpoint is a permanent address that is not yet + // considered to be fully bound to an interface in the traditional + // sense. That is, the address is associated with a NIC, but packets + // destined to the address MUST NOT be accepted and MUST be silently + // dropped, and the address MUST NOT be used as a source address for + // outgoing packets. For IPv6, addresses will be of this kind until + // NDP's Duplicate Address Detection has resolved, or be deleted if + // the process results in detecting a duplicate address. + permanentTentative networkEndpointKind = iota + // A permanent endpoint is created by adding a permanent address (vs. a // temporary one) to the NIC. Its reference count is biased by 1 to avoid // removal when no route holds a reference to it. It is removed by explicitly // removing the permanent address from the NIC. - permanent networkEndpointKind = iota + permanent - // An expired permanent endoint is a permanent endoint that had its address + // An expired permanent endpoint is a permanent endpoint that had its address // removed from the NIC, and it is waiting to be removed once no more routes // hold a reference to it. This is achieved by decreasing its reference count // by 1. If its address is re-added before the endpoint is removed, its type @@ -753,8 +1030,50 @@ const ( temporary ) +func (n *NIC) registerPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep PacketEndpoint) *tcpip.Error { + n.mu.Lock() + defer n.mu.Unlock() + + eps, ok := n.packetEPs[netProto] + if !ok { + return tcpip.ErrNotSupported + } + n.packetEPs[netProto] = append(eps, ep) + + return nil +} + +func (n *NIC) unregisterPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep PacketEndpoint) { + n.mu.Lock() + defer n.mu.Unlock() + + eps, ok := n.packetEPs[netProto] + if !ok { + return + } + + for i, epOther := range eps { + if epOther == ep { + n.packetEPs[netProto] = append(eps[:i], eps[i+1:]...) + return + } + } +} + +type networkEndpointConfigType int32 + +const ( + // A statically configured endpoint is an address that was added by + // some user-specified action (adding an explicit address, joining a + // multicast group). + static networkEndpointConfigType = iota + + // A slaac configured endpoint is an IPv6 endpoint that was + // added by SLAAC as per RFC 4862 section 5.5.3. + slaac +) + type referencedNetworkEndpoint struct { - ilist.Entry ep NetworkEndpoint nic *NIC protocol tcpip.NetworkProtocolNumber @@ -769,6 +1088,10 @@ type referencedNetworkEndpoint struct { // networkEndpointKind must only be accessed using {get,set}Kind(). kind networkEndpointKind + + // configType is the method that was used to configure this endpoint. + // This must never change after the endpoint is added to a NIC. + configType networkEndpointConfigType } func (r *referencedNetworkEndpoint) getKind() networkEndpointKind { @@ -802,11 +1125,14 @@ func (r *referencedNetworkEndpoint) decRef() { } // decRefLocked is the same as decRef but assumes that the NIC.mu mutex is -// locked. -func (r *referencedNetworkEndpoint) decRefLocked() { +// locked. Returns true if the endpoint was removed. +func (r *referencedNetworkEndpoint) decRefLocked() bool { if atomic.AddInt32(&r.refs, -1) == 0 { r.nic.removeEndpointLocked(r) + return true } + + return false } // incRef increments the ref count. It must only be called when the caller is |