diff options
Diffstat (limited to 'pkg/tcpip/network/ipv6')
| -rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 41 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv6/ndp_test.go | 135 |
2 files changed, 161 insertions, 15 deletions
diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index 1c3410618..dc20c0fd7 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -137,21 +137,24 @@ func (e *endpoint) handleICMP(r *stack.Route, netHeader buffer.View, pkt tcpip.P } ns := header.NDPNeighborSolicit(h.NDPPayload()) + it, err := ns.Options().Iter(true) + if err != nil { + // If we have a malformed NDP NS option, drop the packet. + received.Invalid.Increment() + return + } + targetAddr := ns.TargetAddress() s := r.Stack() rxNICID := r.NICID() - - isTentative, err := s.IsAddrTentative(rxNICID, targetAddr) - if err != nil { + if isTentative, err := s.IsAddrTentative(rxNICID, targetAddr); err != nil { // We will only get an error if rxNICID is unrecognized, // which should not happen. For now short-circuit this // packet. // // TODO(b/141002840): Handle this better? return - } - - if isTentative { + } else if isTentative { // If the target address is tentative and the source // of the packet is a unicast (specified) address, then // the source of the packet is attempting to perform @@ -185,6 +188,23 @@ func (e *endpoint) handleICMP(r *stack.Route, netHeader buffer.View, pkt tcpip.P return } + // If the NS message has the source link layer option, update the link + // address cache with the link address for the sender of the message. + // + // TODO(b/148429853): Properly process the NS message and do Neighbor + // Unreachability Detection. + for { + opt, done, _ := it.Next() + if done { + break + } + + switch opt := opt.(type) { + case header.NDPSourceLinkLayerAddressOption: + e.linkAddrCache.AddLinkAddress(e.nicID, r.RemoteAddress, opt.EthernetAddress()) + } + } + optsSerializer := header.NDPOptionsSerializer{ header.NDPTargetLinkLayerAddressOption(r.LocalLinkAddress[:]), } @@ -211,15 +231,6 @@ func (e *endpoint) handleICMP(r *stack.Route, netHeader buffer.View, pkt tcpip.P r.LocalAddress = targetAddr packet.SetChecksum(header.ICMPv6Checksum(packet, r.LocalAddress, r.RemoteAddress, buffer.VectorisedView{})) - // TODO(tamird/ghanan): there exists an explicit NDP option that is - // used to update the neighbor table with link addresses for a - // neighbor from an NS (see the Source Link Layer option RFC - // 4861 section 4.6.1 and section 7.2.3). - // - // Furthermore, the entirety of NDP handling here seems to be - // contradicted by RFC 4861. - e.linkAddrCache.AddLinkAddress(e.nicID, r.RemoteAddress, r.RemoteLinkAddress) - // RFC 4861 Neighbor Discovery for IP version 6 (IPv6) // // 7.1.2. Validation of Neighbor Advertisements diff --git a/pkg/tcpip/network/ipv6/ndp_test.go b/pkg/tcpip/network/ipv6/ndp_test.go index fe895b376..bd732f93f 100644 --- a/pkg/tcpip/network/ipv6/ndp_test.go +++ b/pkg/tcpip/network/ipv6/ndp_test.go @@ -70,6 +70,141 @@ func setupStackAndEndpoint(t *testing.T, llladdr, rlladdr tcpip.Address) (*stack return s, ep } +// TestNeighorSolicitationWithSourceLinkLayerOption tests that receiving an +// NDP NS message with the Source Link Layer Address option results in a +// new entry in the link address cache for the sender of the message. +func TestNeighorSolicitationWithSourceLinkLayerOption(t *testing.T) { + const nicID = 1 + + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{NewProtocol()}, + }) + e := channel.New(0, 1280, linkAddr0) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + if err := s.AddAddress(nicID, ProtocolNumber, lladdr0); err != nil { + t.Fatalf("AddAddress(%d, %d, %s) = %s", nicID, ProtocolNumber, lladdr0, err) + } + + ndpNSSize := header.ICMPv6NeighborSolicitMinimumSize + header.NDPLinkLayerAddressSize + hdr := buffer.NewPrependable(header.IPv6MinimumSize + ndpNSSize) + pkt := header.ICMPv6(hdr.Prepend(ndpNSSize)) + pkt.SetType(header.ICMPv6NeighborSolicit) + ns := header.NDPNeighborSolicit(pkt.NDPPayload()) + ns.SetTargetAddress(lladdr0) + ns.Options().Serialize(header.NDPOptionsSerializer{ + header.NDPSourceLinkLayerAddressOption(linkAddr1), + }) + pkt.SetChecksum(header.ICMPv6Checksum(pkt, lladdr1, lladdr0, buffer.VectorisedView{})) + payloadLength := hdr.UsedLength() + ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize)) + ip.Encode(&header.IPv6Fields{ + PayloadLength: uint16(payloadLength), + NextHeader: uint8(header.ICMPv6ProtocolNumber), + HopLimit: 255, + SrcAddr: lladdr1, + DstAddr: lladdr0, + }) + e.InjectInbound(ProtocolNumber, tcpip.PacketBuffer{ + Data: hdr.View().ToVectorisedView(), + }) + + linkAddr, c, err := s.GetLinkAddress(nicID, lladdr1, lladdr0, ProtocolNumber, nil) + if err != nil { + t.Errorf("s.GetLinkAddress(%d, %s, %s, %d, nil): %s", nicID, lladdr1, lladdr0, ProtocolNumber, err) + } + if c != nil { + t.Errorf("got unexpected channel") + } + if linkAddr != linkAddr1 { + t.Errorf("got link address = %s, want = %s", linkAddr, linkAddr1) + } +} + +// TestNeighorSolicitationWithInvalidSourceLinkLayerOption tests that receiving +// an NDP NS message with an invalid Source Link Layer Address option does not +// result in a new entry in the link address cache for the sender of the +// message. +func TestNeighorSolicitationWithInvalidSourceLinkLayerOption(t *testing.T) { + const nicID = 1 + + tests := []struct { + name string + optsBuf []byte + }{ + { + name: "Too Small", + optsBuf: []byte{1, 1, 1, 2, 3, 4, 5}, + }, + { + name: "Invalid Length", + optsBuf: []byte{1, 2, 1, 2, 3, 4, 5, 6}, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{NewProtocol()}, + }) + e := channel.New(0, 1280, linkAddr0) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + if err := s.AddAddress(nicID, ProtocolNumber, lladdr0); err != nil { + t.Fatalf("AddAddress(%d, %d, %s) = %s", nicID, ProtocolNumber, lladdr0, err) + } + + ndpNSSize := header.ICMPv6NeighborSolicitMinimumSize + len(test.optsBuf) + hdr := buffer.NewPrependable(header.IPv6MinimumSize + ndpNSSize) + pkt := header.ICMPv6(hdr.Prepend(ndpNSSize)) + pkt.SetType(header.ICMPv6NeighborSolicit) + ns := header.NDPNeighborSolicit(pkt.NDPPayload()) + ns.SetTargetAddress(lladdr0) + opts := ns.Options() + copy(opts, test.optsBuf) + pkt.SetChecksum(header.ICMPv6Checksum(pkt, lladdr1, lladdr0, buffer.VectorisedView{})) + payloadLength := hdr.UsedLength() + ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize)) + ip.Encode(&header.IPv6Fields{ + PayloadLength: uint16(payloadLength), + NextHeader: uint8(header.ICMPv6ProtocolNumber), + HopLimit: 255, + SrcAddr: lladdr1, + DstAddr: lladdr0, + }) + + invalid := s.Stats().ICMP.V6PacketsReceived.Invalid + + // Invalid count should initially be 0. + if got := invalid.Value(); got != 0 { + t.Fatalf("got invalid = %d, want = 0", got) + } + + e.InjectInbound(ProtocolNumber, tcpip.PacketBuffer{ + Data: hdr.View().ToVectorisedView(), + }) + + // Invalid count should have increased. + if got := invalid.Value(); got != 1 { + t.Fatalf("got invalid = %d, want = 1", got) + } + + linkAddr, c, err := s.GetLinkAddress(nicID, lladdr1, lladdr0, ProtocolNumber, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got s.GetLinkAddress(%d, %s, %s, %d, nil) = (_, _, %v), want = (_, _, %s)", nicID, lladdr1, lladdr0, ProtocolNumber, err, tcpip.ErrWouldBlock) + } + if c == nil { + t.Errorf("expected channel from call to s.GetLinkAddress(%d, %s, %s, %d, nil)", nicID, lladdr1, lladdr0, ProtocolNumber) + } + if linkAddr != "" { + t.Errorf("got s.GetLinkAddress(%d, %s, %s, %d, nil) = (%s, _, ), want = ('', _, _)", nicID, lladdr1, lladdr0, ProtocolNumber, linkAddr) + } + }) + } +} + // TestHopLimitValidation is a test that makes sure that NDP packets are only // received if their IP header's hop limit is set to 255. func TestHopLimitValidation(t *testing.T) { |