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authorGhanan Gowripalan <ghanan@google.com>2020-01-27 20:28:14 -0800
committergVisor bot <gvisor-bot@google.com>2020-01-27 20:51:28 -0800
commit2a2da5be31ea3c32e66f0c0ff61ef189848f5258 (patch)
treeb15f052e79cbf166dc362a4d0a62b5cb040134d3
parent5776a7b6f6b52faf6e0735c3f4a892639c1bd773 (diff)
Add a type to represent the NDP Source Link Layer Address option
Tests: - header.TestNDPSourceLinkLayerAddressOptionEthernetAddress - header.TestNDPSourceLinkLayerAddressOptionSerialize - header.TestNDPOptionsIterCheck - header.TestNDPOptionsIter PiperOrigin-RevId: 291856429
-rw-r--r--pkg/tcpip/header/icmpv6.go2
-rw-r--r--pkg/tcpip/header/ndp_options.go52
-rw-r--r--pkg/tcpip/header/ndp_test.go180
3 files changed, 214 insertions, 20 deletions
diff --git a/pkg/tcpip/header/icmpv6.go b/pkg/tcpip/header/icmpv6.go
index b4037b6c8..b095dc0ab 100644
--- a/pkg/tcpip/header/icmpv6.go
+++ b/pkg/tcpip/header/icmpv6.go
@@ -52,7 +52,7 @@ const (
// ICMPv6NeighborAdvertSize is size of a neighbor advertisement
// including the NDP Target Link Layer option for an Ethernet
// address.
- ICMPv6NeighborAdvertSize = ICMPv6HeaderSize + NDPNAMinimumSize + ndpTargetEthernetLinkLayerAddressSize
+ ICMPv6NeighborAdvertSize = ICMPv6HeaderSize + NDPNAMinimumSize + ndpLinkLayerAddressSize
// ICMPv6EchoMinimumSize is the minimum size of a valid ICMP echo packet.
ICMPv6EchoMinimumSize = 8
diff --git a/pkg/tcpip/header/ndp_options.go b/pkg/tcpip/header/ndp_options.go
index 06e0bace2..1e60f3d4f 100644
--- a/pkg/tcpip/header/ndp_options.go
+++ b/pkg/tcpip/header/ndp_options.go
@@ -24,13 +24,17 @@ import (
)
const (
- // NDPTargetLinkLayerAddressOptionType is the type of the Target
- // Link-Layer Address option, as per RFC 4861 section 4.6.1.
+ // NDPSourceLinkLayerAddressOptionType is the type of the Source Link Layer
+ // Address option, as per RFC 4861 section 4.6.1.
+ NDPSourceLinkLayerAddressOptionType = 1
+
+ // NDPTargetLinkLayerAddressOptionType is the type of the Target Link Layer
+ // Address option, as per RFC 4861 section 4.6.1.
NDPTargetLinkLayerAddressOptionType = 2
- // ndpTargetEthernetLinkLayerAddressSize is the size of a Target
- // Link Layer Option for an Ethernet address.
- ndpTargetEthernetLinkLayerAddressSize = 8
+ // ndpLinkLayerAddressSize is the size of a Source or Target Link Layer
+ // Address option.
+ ndpLinkLayerAddressSize = 8
// NDPPrefixInformationType is the type of the Prefix Information
// option, as per RFC 4861 section 4.6.2.
@@ -189,6 +193,9 @@ func (i *NDPOptionIterator) Next() (NDPOption, bool, error) {
i.opts = i.opts[numBytes:]
switch t {
+ case NDPSourceLinkLayerAddressOptionType:
+ return NDPSourceLinkLayerAddressOption(body), false, nil
+
case NDPTargetLinkLayerAddressOptionType:
return NDPTargetLinkLayerAddressOption(body), false, nil
@@ -368,6 +375,41 @@ func (b NDPOptionsSerializer) Length() int {
return l
}
+// NDPSourceLinkLayerAddressOption is the NDP Source Link Layer Option
+// as defined by RFC 4861 section 4.6.1.
+//
+// It is the first X bytes following the NDP option's Type and Length field
+// where X is the value in Length multiplied by lengthByteUnits - 2 bytes.
+type NDPSourceLinkLayerAddressOption tcpip.LinkAddress
+
+// Type implements NDPOption.Type.
+func (o NDPSourceLinkLayerAddressOption) Type() uint8 {
+ return NDPSourceLinkLayerAddressOptionType
+}
+
+// Length implements NDPOption.Length.
+func (o NDPSourceLinkLayerAddressOption) Length() int {
+ return len(o)
+}
+
+// serializeInto implements NDPOption.serializeInto.
+func (o NDPSourceLinkLayerAddressOption) serializeInto(b []byte) int {
+ return copy(b, o)
+}
+
+// EthernetAddress will return an ethernet (MAC) address if the
+// NDPSourceLinkLayerAddressOption's body has at minimum EthernetAddressSize
+// bytes. If the body has more than EthernetAddressSize bytes, only the first
+// EthernetAddressSize bytes are returned as that is all that is needed for an
+// Ethernet address.
+func (o NDPSourceLinkLayerAddressOption) EthernetAddress() tcpip.LinkAddress {
+ if len(o) >= EthernetAddressSize {
+ return tcpip.LinkAddress(o[:EthernetAddressSize])
+ }
+
+ return tcpip.LinkAddress([]byte(nil))
+}
+
// NDPTargetLinkLayerAddressOption is the NDP Target Link Layer Option
// as defined by RFC 4861 section 4.6.1.
//
diff --git a/pkg/tcpip/header/ndp_test.go b/pkg/tcpip/header/ndp_test.go
index 2c439d70c..1cb9f5dc8 100644
--- a/pkg/tcpip/header/ndp_test.go
+++ b/pkg/tcpip/header/ndp_test.go
@@ -153,6 +153,125 @@ func TestNDPRouterAdvert(t *testing.T) {
}
}
+// TestNDPSourceLinkLayerAddressOptionEthernetAddress tests getting the
+// Ethernet address from an NDPSourceLinkLayerAddressOption.
+func TestNDPSourceLinkLayerAddressOptionEthernetAddress(t *testing.T) {
+ tests := []struct {
+ name string
+ buf []byte
+ expected tcpip.LinkAddress
+ }{
+ {
+ "ValidMAC",
+ []byte{1, 2, 3, 4, 5, 6},
+ tcpip.LinkAddress("\x01\x02\x03\x04\x05\x06"),
+ },
+ {
+ "SLLBodyTooShort",
+ []byte{1, 2, 3, 4, 5},
+ tcpip.LinkAddress([]byte(nil)),
+ },
+ {
+ "SLLBodyLargerThanNeeded",
+ []byte{1, 2, 3, 4, 5, 6, 7, 8},
+ tcpip.LinkAddress("\x01\x02\x03\x04\x05\x06"),
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ sll := NDPSourceLinkLayerAddressOption(test.buf)
+ if got := sll.EthernetAddress(); got != test.expected {
+ t.Errorf("got sll.EthernetAddress = %s, want = %s", got, test.expected)
+ }
+ })
+ }
+}
+
+// TestNDPSourceLinkLayerAddressOptionSerialize tests serializing a
+// NDPSourceLinkLayerAddressOption.
+func TestNDPSourceLinkLayerAddressOptionSerialize(t *testing.T) {
+ tests := []struct {
+ name string
+ buf []byte
+ expectedBuf []byte
+ addr tcpip.LinkAddress
+ }{
+ {
+ "Ethernet",
+ make([]byte, 8),
+ []byte{1, 1, 1, 2, 3, 4, 5, 6},
+ "\x01\x02\x03\x04\x05\x06",
+ },
+ {
+ "Padding",
+ []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1},
+ []byte{1, 2, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0},
+ "\x01\x02\x03\x04\x05\x06\x07\x08",
+ },
+ {
+ "Empty",
+ nil,
+ nil,
+ "",
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ opts := NDPOptions(test.buf)
+ serializer := NDPOptionsSerializer{
+ NDPSourceLinkLayerAddressOption(test.addr),
+ }
+ if got, want := int(serializer.Length()), len(test.expectedBuf); got != want {
+ t.Fatalf("got Length = %d, want = %d", got, want)
+ }
+ opts.Serialize(serializer)
+ if !bytes.Equal(test.buf, test.expectedBuf) {
+ t.Fatalf("got b = %d, want = %d", test.buf, test.expectedBuf)
+ }
+
+ it, err := opts.Iter(true)
+ if err != nil {
+ t.Fatalf("got Iter = (_, %s), want = (_, nil)", err)
+ }
+
+ if len(test.expectedBuf) > 0 {
+ next, done, err := it.Next()
+ if err != nil {
+ t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err)
+ }
+ if done {
+ t.Fatal("got Next = (_, true, _), want = (_, false, _)")
+ }
+ if got := next.Type(); got != NDPSourceLinkLayerAddressOptionType {
+ t.Fatalf("got Type = %d, want = %d", got, NDPSourceLinkLayerAddressOptionType)
+ }
+ sll := next.(NDPSourceLinkLayerAddressOption)
+ if got, want := []byte(sll), test.expectedBuf[2:]; !bytes.Equal(got, want) {
+ t.Fatalf("got Next = (%x, _, _), want = (%x, _, _)", got, want)
+ }
+
+ if got, want := sll.EthernetAddress(), tcpip.LinkAddress(test.expectedBuf[2:][:EthernetAddressSize]); got != want {
+ t.Errorf("got sll.EthernetAddress = %s, want = %s", got, want)
+ }
+ }
+
+ // Iterator should not return anything else.
+ next, done, err := it.Next()
+ if err != nil {
+ t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err)
+ }
+ if !done {
+ t.Error("got Next = (_, false, _), want = (_, true, _)")
+ }
+ if next != nil {
+ t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next)
+ }
+ })
+ }
+}
+
// TestNDPTargetLinkLayerAddressOptionEthernetAddress tests getting the
// Ethernet address from an NDPTargetLinkLayerAddressOption.
func TestNDPTargetLinkLayerAddressOptionEthernetAddress(t *testing.T) {
@@ -186,7 +305,6 @@ func TestNDPTargetLinkLayerAddressOptionEthernetAddress(t *testing.T) {
}
})
}
-
}
// TestNDPTargetLinkLayerAddressOptionSerialize tests serializing a
@@ -212,8 +330,8 @@ func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) {
},
{
"Empty",
- []byte{},
- []byte{},
+ nil,
+ nil,
"",
},
}
@@ -246,7 +364,7 @@ func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) {
t.Fatal("got Next = (_, true, _), want = (_, false, _)")
}
if got := next.Type(); got != NDPTargetLinkLayerAddressOptionType {
- t.Fatalf("got Type %= %d, want = %d", got, NDPTargetLinkLayerAddressOptionType)
+ t.Fatalf("got Type = %d, want = %d", got, NDPTargetLinkLayerAddressOptionType)
}
tll := next.(NDPTargetLinkLayerAddressOption)
if got, want := []byte(tll), test.expectedBuf[2:]; !bytes.Equal(got, want) {
@@ -254,7 +372,7 @@ func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) {
}
if got, want := tll.EthernetAddress(), tcpip.LinkAddress(test.expectedBuf[2:][:EthernetAddressSize]); got != want {
- t.Errorf("got tll.MACAddress = %s, want = %s", got, want)
+ t.Errorf("got tll.EthernetAddress = %s, want = %s", got, want)
}
}
@@ -510,7 +628,7 @@ func TestNDPRecursiveDNSServerOption(t *testing.T) {
t.Fatal("got Next = (_, true, _), want = (_, false, _)")
}
if got := next.Type(); got != NDPRecursiveDNSServerOptionType {
- t.Fatalf("got Type %= %d, want = %d", got, NDPRecursiveDNSServerOptionType)
+ t.Fatalf("got Type = %d, want = %d", got, NDPRecursiveDNSServerOptionType)
}
opt, ok := next.(NDPRecursiveDNSServer)
@@ -553,6 +671,16 @@ func TestNDPOptionsIterCheck(t *testing.T) {
ErrNDPOptZeroLength,
},
{
+ "ValidSourceLinkLayerAddressOption",
+ []byte{1, 1, 1, 2, 3, 4, 5, 6},
+ nil,
+ },
+ {
+ "TooSmallSourceLinkLayerAddressOption",
+ []byte{1, 1, 1, 2, 3, 4, 5},
+ ErrNDPOptBufExhausted,
+ },
+ {
"ValidTargetLinkLayerAddressOption",
[]byte{2, 1, 1, 2, 3, 4, 5, 6},
nil,
@@ -603,10 +731,13 @@ func TestNDPOptionsIterCheck(t *testing.T) {
ErrNDPOptMalformedBody,
},
{
- "ValidTargetLinkLayerAddressWithPrefixInformation",
+ "ValidSourceAndTargetLinkLayerAddressWithPrefixInformation",
[]byte{
+ // Source Link-Layer Address.
+ 1, 1, 1, 2, 3, 4, 5, 6,
+
// Target Link-Layer Address.
- 2, 1, 1, 2, 3, 4, 5, 6,
+ 2, 1, 7, 8, 9, 10, 11, 12,
// Prefix information.
3, 4, 43, 64,
@@ -621,10 +752,13 @@ func TestNDPOptionsIterCheck(t *testing.T) {
nil,
},
{
- "ValidTargetLinkLayerAddressWithPrefixInformationWithUnrecognized",
+ "ValidSourceAndTargetLinkLayerAddressWithPrefixInformationWithUnrecognized",
[]byte{
+ // Source Link-Layer Address.
+ 1, 1, 1, 2, 3, 4, 5, 6,
+
// Target Link-Layer Address.
- 2, 1, 1, 2, 3, 4, 5, 6,
+ 2, 1, 7, 8, 9, 10, 11, 12,
// 255 is an unrecognized type. If 255 ends up
// being the type for some recognized type,
@@ -714,8 +848,11 @@ func TestNDPOptionsIterCheck(t *testing.T) {
// here.
func TestNDPOptionsIter(t *testing.T) {
buf := []byte{
+ // Source Link-Layer Address.
+ 1, 1, 1, 2, 3, 4, 5, 6,
+
// Target Link-Layer Address.
- 2, 1, 1, 2, 3, 4, 5, 6,
+ 2, 1, 7, 8, 9, 10, 11, 12,
// 255 is an unrecognized type. If 255 ends up being the type
// for some recognized type, update 255 to some other
@@ -740,7 +877,7 @@ func TestNDPOptionsIter(t *testing.T) {
t.Fatalf("got Iter = (_, %s), want = (_, nil)", err)
}
- // Test the first (Taret Link-Layer) option.
+ // Test the first (Source Link-Layer) option.
next, done, err := it.Next()
if err != nil {
t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err)
@@ -748,7 +885,22 @@ func TestNDPOptionsIter(t *testing.T) {
if done {
t.Fatal("got Next = (_, true, _), want = (_, false, _)")
}
- if got, want := []byte(next.(NDPTargetLinkLayerAddressOption)), buf[2:][:6]; !bytes.Equal(got, want) {
+ if got, want := []byte(next.(NDPSourceLinkLayerAddressOption)), buf[2:][:6]; !bytes.Equal(got, want) {
+ t.Errorf("got Next = (%x, _, _), want = (%x, _, _)", got, want)
+ }
+ if got := next.Type(); got != NDPSourceLinkLayerAddressOptionType {
+ t.Errorf("got Type = %d, want = %d", got, NDPSourceLinkLayerAddressOptionType)
+ }
+
+ // Test the next (Target Link-Layer) option.
+ next, done, err = it.Next()
+ if err != nil {
+ t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err)
+ }
+ if done {
+ t.Fatal("got Next = (_, true, _), want = (_, false, _)")
+ }
+ if got, want := []byte(next.(NDPTargetLinkLayerAddressOption)), buf[10:][:6]; !bytes.Equal(got, want) {
t.Errorf("got Next = (%x, _, _), want = (%x, _, _)", got, want)
}
if got := next.Type(); got != NDPTargetLinkLayerAddressOptionType {
@@ -764,7 +916,7 @@ func TestNDPOptionsIter(t *testing.T) {
if done {
t.Fatal("got Next = (_, true, _), want = (_, false, _)")
}
- if got, want := next.(NDPPrefixInformation), buf[26:][:30]; !bytes.Equal(got, want) {
+ if got, want := next.(NDPPrefixInformation), buf[34:][:30]; !bytes.Equal(got, want) {
t.Errorf("got Next = (%x, _, _), want = (%x, _, _)", got, want)
}
if got := next.Type(); got != NDPPrefixInformationType {