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-rw-r--r--pkg/tcpip/network/ipv6/icmp.go41
-rw-r--r--pkg/tcpip/network/ipv6/ndp_test.go135
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) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 14:37:19 +0000