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-rw-r--r--pkg/tcpip/header/BUILD19
-rw-r--r--pkg/tcpip/header/checksum.go50
-rw-r--r--pkg/tcpip/header/checksum_test.go109
-rw-r--r--pkg/tcpip/header/eth.go62
-rw-r--r--pkg/tcpip/header/eth_test.go68
-rw-r--r--pkg/tcpip/header/icmpv6.go32
-rw-r--r--pkg/tcpip/header/ipv6.go12
-rw-r--r--pkg/tcpip/header/ndp_neighbor_advert.go110
-rw-r--r--pkg/tcpip/header/ndp_neighbor_solicit.go52
-rw-r--r--pkg/tcpip/header/ndp_options.go172
-rw-r--r--pkg/tcpip/header/ndp_router_advert.go112
-rw-r--r--pkg/tcpip/header/ndp_test.go199
12 files changed, 981 insertions, 16 deletions
diff --git a/pkg/tcpip/header/BUILD b/pkg/tcpip/header/BUILD
index a255231a3..a3485b35c 100644
--- a/pkg/tcpip/header/BUILD
+++ b/pkg/tcpip/header/BUILD
@@ -16,6 +16,10 @@ go_library(
"ipv4.go",
"ipv6.go",
"ipv6_fragment.go",
+ "ndp_neighbor_advert.go",
+ "ndp_neighbor_solicit.go",
+ "ndp_options.go",
+ "ndp_router_advert.go",
"tcp.go",
"udp.go",
],
@@ -30,13 +34,26 @@ go_library(
)
go_test(
- name = "header_test",
+ name = "header_x_test",
size = "small",
srcs = [
+ "checksum_test.go",
"ipversion_test.go",
"tcp_test.go",
],
deps = [
":header",
+ "//pkg/tcpip/buffer",
+ ],
+)
+
+go_test(
+ name = "header_test",
+ size = "small",
+ srcs = [
+ "eth_test.go",
+ "ndp_test.go",
],
+ embed = [":header"],
+ deps = ["//pkg/tcpip"],
)
diff --git a/pkg/tcpip/header/checksum.go b/pkg/tcpip/header/checksum.go
index 39a4d69be..9749c7f4d 100644
--- a/pkg/tcpip/header/checksum.go
+++ b/pkg/tcpip/header/checksum.go
@@ -23,11 +23,17 @@ import (
"gvisor.dev/gvisor/pkg/tcpip/buffer"
)
-func calculateChecksum(buf []byte, initial uint32) uint16 {
+func calculateChecksum(buf []byte, odd bool, initial uint32) (uint16, bool) {
v := initial
+ if odd {
+ v += uint32(buf[0])
+ buf = buf[1:]
+ }
+
l := len(buf)
- if l&1 != 0 {
+ odd = l&1 != 0
+ if odd {
l--
v += uint32(buf[l]) << 8
}
@@ -36,7 +42,7 @@ func calculateChecksum(buf []byte, initial uint32) uint16 {
v += (uint32(buf[i]) << 8) + uint32(buf[i+1])
}
- return ChecksumCombine(uint16(v), uint16(v>>16))
+ return ChecksumCombine(uint16(v), uint16(v>>16)), odd
}
// Checksum calculates the checksum (as defined in RFC 1071) of the bytes in the
@@ -44,7 +50,8 @@ func calculateChecksum(buf []byte, initial uint32) uint16 {
//
// The initial checksum must have been computed on an even number of bytes.
func Checksum(buf []byte, initial uint16) uint16 {
- return calculateChecksum(buf, uint32(initial))
+ s, _ := calculateChecksum(buf, false, uint32(initial))
+ return s
}
// ChecksumVV calculates the checksum (as defined in RFC 1071) of the bytes in
@@ -52,19 +59,40 @@ func Checksum(buf []byte, initial uint16) uint16 {
//
// The initial checksum must have been computed on an even number of bytes.
func ChecksumVV(vv buffer.VectorisedView, initial uint16) uint16 {
- var odd bool
+ return ChecksumVVWithOffset(vv, initial, 0, vv.Size())
+}
+
+// ChecksumVVWithOffset calculates the checksum (as defined in RFC 1071) of the
+// bytes in the given VectorizedView.
+//
+// The initial checksum must have been computed on an even number of bytes.
+func ChecksumVVWithOffset(vv buffer.VectorisedView, initial uint16, off int, size int) uint16 {
+ odd := false
sum := initial
for _, v := range vv.Views() {
if len(v) == 0 {
continue
}
- s := uint32(sum)
- if odd {
- s += uint32(v[0])
- v = v[1:]
+
+ if off >= len(v) {
+ off -= len(v)
+ continue
+ }
+ v = v[off:]
+
+ l := len(v)
+ if l > size {
+ l = size
+ }
+ v = v[:l]
+
+ sum, odd = calculateChecksum(v, odd, uint32(sum))
+
+ size -= len(v)
+ if size == 0 {
+ break
}
- odd = len(v)&1 != 0
- sum = calculateChecksum(v, s)
+ off = 0
}
return sum
}
diff --git a/pkg/tcpip/header/checksum_test.go b/pkg/tcpip/header/checksum_test.go
new file mode 100644
index 000000000..86b466c1c
--- /dev/null
+++ b/pkg/tcpip/header/checksum_test.go
@@ -0,0 +1,109 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package header provides the implementation of the encoding and decoding of
+// network protocol headers.
+package header_test
+
+import (
+ "testing"
+
+ "gvisor.dev/gvisor/pkg/tcpip/buffer"
+ "gvisor.dev/gvisor/pkg/tcpip/header"
+)
+
+func TestChecksumVVWithOffset(t *testing.T) {
+ testCases := []struct {
+ name string
+ vv buffer.VectorisedView
+ off, size int
+ initial uint16
+ want uint16
+ }{
+ {
+ name: "empty",
+ vv: buffer.NewVectorisedView(0, []buffer.View{
+ buffer.NewViewFromBytes([]byte{1, 9, 0, 5, 4}),
+ }),
+ off: 0,
+ size: 0,
+ want: 0,
+ },
+ {
+ name: "OneView",
+ vv: buffer.NewVectorisedView(0, []buffer.View{
+ buffer.NewViewFromBytes([]byte{1, 9, 0, 5, 4}),
+ }),
+ off: 0,
+ size: 5,
+ want: 1294,
+ },
+ {
+ name: "TwoViews",
+ vv: buffer.NewVectorisedView(0, []buffer.View{
+ buffer.NewViewFromBytes([]byte{1, 9, 0, 5, 4}),
+ buffer.NewViewFromBytes([]byte{4, 3, 7, 1, 2, 123}),
+ }),
+ off: 0,
+ size: 11,
+ want: 33819,
+ },
+ {
+ name: "TwoViewsWithOffset",
+ vv: buffer.NewVectorisedView(0, []buffer.View{
+ buffer.NewViewFromBytes([]byte{98, 1, 9, 0, 5, 4}),
+ buffer.NewViewFromBytes([]byte{4, 3, 7, 1, 2, 123}),
+ }),
+ off: 1,
+ size: 11,
+ want: 33819,
+ },
+ {
+ name: "ThreeViewsWithOffset",
+ vv: buffer.NewVectorisedView(0, []buffer.View{
+ buffer.NewViewFromBytes([]byte{98, 1, 9, 0, 5, 4}),
+ buffer.NewViewFromBytes([]byte{98, 1, 9, 0, 5, 4}),
+ buffer.NewViewFromBytes([]byte{4, 3, 7, 1, 2, 123}),
+ }),
+ off: 7,
+ size: 11,
+ want: 33819,
+ },
+ {
+ name: "ThreeViewsWithInitial",
+ vv: buffer.NewVectorisedView(0, []buffer.View{
+ buffer.NewViewFromBytes([]byte{77, 11, 33, 0, 55, 44}),
+ buffer.NewViewFromBytes([]byte{98, 1, 9, 0, 5, 4}),
+ buffer.NewViewFromBytes([]byte{4, 3, 7, 1, 2, 123, 99}),
+ }),
+ initial: 77,
+ off: 7,
+ size: 11,
+ want: 33896,
+ },
+ }
+ for _, tc := range testCases {
+ t.Run(tc.name, func(t *testing.T) {
+ if got, want := header.ChecksumVVWithOffset(tc.vv, tc.initial, tc.off, tc.size), tc.want; got != want {
+ t.Errorf("header.ChecksumVVWithOffset(%v) = %v, want: %v", tc, got, tc.want)
+ }
+ v := tc.vv.ToView()
+ v.TrimFront(tc.off)
+ v.CapLength(tc.size)
+ if got, want := header.Checksum(v, tc.initial), tc.want; got != want {
+ t.Errorf("header.Checksum(%v) = %v, want: %v", tc, got, tc.want)
+ }
+ })
+ }
+}
diff --git a/pkg/tcpip/header/eth.go b/pkg/tcpip/header/eth.go
index 4c3d3311f..f5d2c127f 100644
--- a/pkg/tcpip/header/eth.go
+++ b/pkg/tcpip/header/eth.go
@@ -48,8 +48,48 @@ const (
// EthernetAddressSize is the size, in bytes, of an ethernet address.
EthernetAddressSize = 6
+
+ // unspecifiedEthernetAddress is the unspecified ethernet address
+ // (all bits set to 0).
+ unspecifiedEthernetAddress = tcpip.LinkAddress("\x00\x00\x00\x00\x00\x00")
+
+ // unicastMulticastFlagMask is the mask of the least significant bit in
+ // the first octet (in network byte order) of an ethernet address that
+ // determines whether the ethernet address is a unicast or multicast. If
+ // the masked bit is a 1, then the address is a multicast, unicast
+ // otherwise.
+ //
+ // See the IEEE Std 802-2001 document for more details. Specifically,
+ // section 9.2.1 of http://ieee802.org/secmail/pdfocSP2xXA6d.pdf:
+ // "A 48-bit universal address consists of two parts. The first 24 bits
+ // correspond to the OUI as assigned by the IEEE, expect that the
+ // assignee may set the LSB of the first octet to 1 for group addresses
+ // or set it to 0 for individual addresses."
+ unicastMulticastFlagMask = 1
+
+ // unicastMulticastFlagByteIdx is the byte that holds the
+ // unicast/multicast flag. See unicastMulticastFlagMask.
+ unicastMulticastFlagByteIdx = 0
+)
+
+const (
+ // EthernetProtocolAll is a catch-all for all protocols carried inside
+ // an ethernet frame. It is mainly used to create packet sockets that
+ // capture all traffic.
+ EthernetProtocolAll tcpip.NetworkProtocolNumber = 0x0003
+
+ // EthernetProtocolPUP is the PARC Universial Packet protocol ethertype.
+ EthernetProtocolPUP tcpip.NetworkProtocolNumber = 0x0200
)
+// Ethertypes holds the protocol numbers describing the payload of an ethernet
+// frame. These types aren't necessarily supported by netstack, but can be used
+// to catch all traffic of a type via packet endpoints.
+var Ethertypes = []tcpip.NetworkProtocolNumber{
+ EthernetProtocolAll,
+ EthernetProtocolPUP,
+}
+
// SourceAddress returns the "MAC source" field of the ethernet frame header.
func (b Ethernet) SourceAddress() tcpip.LinkAddress {
return tcpip.LinkAddress(b[srcMAC:][:EthernetAddressSize])
@@ -72,3 +112,25 @@ func (b Ethernet) Encode(e *EthernetFields) {
copy(b[srcMAC:][:EthernetAddressSize], e.SrcAddr)
copy(b[dstMAC:][:EthernetAddressSize], e.DstAddr)
}
+
+// IsValidUnicastEthernetAddress returns true if addr is a valid unicast
+// ethernet address.
+func IsValidUnicastEthernetAddress(addr tcpip.LinkAddress) bool {
+ // Must be of the right length.
+ if len(addr) != EthernetAddressSize {
+ return false
+ }
+
+ // Must not be unspecified.
+ if addr == unspecifiedEthernetAddress {
+ return false
+ }
+
+ // Must not be a multicast.
+ if addr[unicastMulticastFlagByteIdx]&unicastMulticastFlagMask != 0 {
+ return false
+ }
+
+ // addr is a valid unicast ethernet address.
+ return true
+}
diff --git a/pkg/tcpip/header/eth_test.go b/pkg/tcpip/header/eth_test.go
new file mode 100644
index 000000000..6634c90f5
--- /dev/null
+++ b/pkg/tcpip/header/eth_test.go
@@ -0,0 +1,68 @@
+// Copyright 2018 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package header
+
+import (
+ "testing"
+
+ "gvisor.dev/gvisor/pkg/tcpip"
+)
+
+func TestIsValidUnicastEthernetAddress(t *testing.T) {
+ tests := []struct {
+ name string
+ addr tcpip.LinkAddress
+ expected bool
+ }{
+ {
+ "Nil",
+ tcpip.LinkAddress([]byte(nil)),
+ false,
+ },
+ {
+ "Empty",
+ tcpip.LinkAddress(""),
+ false,
+ },
+ {
+ "InvalidLength",
+ tcpip.LinkAddress("\x01\x02\x03"),
+ false,
+ },
+ {
+ "Unspecified",
+ unspecifiedEthernetAddress,
+ false,
+ },
+ {
+ "Multicast",
+ tcpip.LinkAddress("\x01\x02\x03\x04\x05\x06"),
+ false,
+ },
+ {
+ "Valid",
+ tcpip.LinkAddress("\x02\x02\x03\x04\x05\x06"),
+ true,
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ if got := IsValidUnicastEthernetAddress(test.addr); got != test.expected {
+ t.Fatalf("got IsValidUnicastEthernetAddress = %t, want = %t", got, test.expected)
+ }
+ })
+ }
+}
diff --git a/pkg/tcpip/header/icmpv6.go b/pkg/tcpip/header/icmpv6.go
index 1125a7d14..c2bfd8c79 100644
--- a/pkg/tcpip/header/icmpv6.go
+++ b/pkg/tcpip/header/icmpv6.go
@@ -25,6 +25,12 @@ import (
type ICMPv6 []byte
const (
+ // ICMPv6HeaderSize is the size of the ICMPv6 header. That is, the
+ // sum of the size of the ICMPv6 Type, Code and Checksum fields, as
+ // per RFC 4443 section 2.1. After the ICMPv6 header, the ICMPv6
+ // message body begins.
+ ICMPv6HeaderSize = 4
+
// ICMPv6MinimumSize is the minimum size of a valid ICMP packet.
ICMPv6MinimumSize = 8
@@ -37,10 +43,16 @@ const (
// ICMPv6NeighborSolicitMinimumSize is the minimum size of a
// neighbor solicitation packet.
- ICMPv6NeighborSolicitMinimumSize = ICMPv6MinimumSize + 16
+ ICMPv6NeighborSolicitMinimumSize = ICMPv6HeaderSize + NDPNSMinimumSize
+
+ // ICMPv6NeighborAdvertMinimumSize is the minimum size of a
+ // neighbor advertisement packet.
+ ICMPv6NeighborAdvertMinimumSize = ICMPv6HeaderSize + NDPNAMinimumSize
- // ICMPv6NeighborAdvertSize is size of a neighbor advertisement.
- ICMPv6NeighborAdvertSize = 32
+ // ICMPv6NeighborAdvertSize is size of a neighbor advertisement
+ // including the NDP Target Link Layer option for an Ethernet
+ // address.
+ ICMPv6NeighborAdvertSize = ICMPv6HeaderSize + NDPNAMinimumSize + ndpTargetEthernetLinkLayerAddressSize
// ICMPv6EchoMinimumSize is the minimum size of a valid ICMP echo packet.
ICMPv6EchoMinimumSize = 8
@@ -68,6 +80,13 @@ const (
// icmpv6SequenceOffset is the offset of the sequence field
// in a ICMPv6 Echo Request/Reply message.
icmpv6SequenceOffset = 6
+
+ // NDPHopLimit is the expected IP hop limit value of 255 for received
+ // NDP packets, as per RFC 4861 sections 4.1 - 4.5, 6.1.1, 6.1.2, 7.1.1,
+ // 7.1.2 and 8.1. If the hop limit value is not 255, nodes MUST silently
+ // drop the NDP packet. All outgoing NDP packets must use this value for
+ // its IP hop limit field.
+ NDPHopLimit = 255
)
// ICMPv6Type is the ICMP type field described in RFC 4443 and friends.
@@ -166,6 +185,13 @@ func (b ICMPv6) SetSequence(sequence uint16) {
binary.BigEndian.PutUint16(b[icmpv6SequenceOffset:], sequence)
}
+// NDPPayload returns the NDP payload buffer. That is, it returns the ICMPv6
+// packet's message body as defined by RFC 4443 section 2.1; the portion of the
+// ICMPv6 buffer after the first ICMPv6HeaderSize bytes.
+func (b ICMPv6) NDPPayload() []byte {
+ return b[ICMPv6HeaderSize:]
+}
+
// Payload implements Transport.Payload.
func (b ICMPv6) Payload() []byte {
return b[ICMPv6PayloadOffset:]
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go
index 9d3abc0e4..f1e60911b 100644
--- a/pkg/tcpip/header/ipv6.go
+++ b/pkg/tcpip/header/ipv6.go
@@ -87,7 +87,8 @@ const (
// section 5.
IPv6MinimumMTU = 1280
- // IPv6Any is the non-routable IPv6 "any" meta address.
+ // IPv6Any is the non-routable IPv6 "any" meta address. It is also
+ // known as the unspecified address.
IPv6Any tcpip.Address = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
)
@@ -100,6 +101,15 @@ var IPv6EmptySubnet = func() tcpip.Subnet {
return subnet
}()
+// IPv6LinkLocalPrefix is the prefix for IPv6 link-local addresses, as defined
+// by RFC 4291 section 2.5.6.
+//
+// The prefix is fe80::/64
+var IPv6LinkLocalPrefix = tcpip.AddressWithPrefix{
+ Address: "\xfe\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00",
+ PrefixLen: 64,
+}
+
// PayloadLength returns the value of the "payload length" field of the ipv6
// header.
func (b IPv6) PayloadLength() uint16 {
diff --git a/pkg/tcpip/header/ndp_neighbor_advert.go b/pkg/tcpip/header/ndp_neighbor_advert.go
new file mode 100644
index 000000000..505c92668
--- /dev/null
+++ b/pkg/tcpip/header/ndp_neighbor_advert.go
@@ -0,0 +1,110 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package header
+
+import "gvisor.dev/gvisor/pkg/tcpip"
+
+// NDPNeighborAdvert is an NDP Neighbor Advertisement message. It will
+// only contain the body of an ICMPv6 packet.
+//
+// See RFC 4861 section 4.4 for more details.
+type NDPNeighborAdvert []byte
+
+const (
+ // NDPNAMinimumSize is the minimum size of a valid NDP Neighbor
+ // Advertisement message (body of an ICMPv6 packet).
+ NDPNAMinimumSize = 20
+
+ // ndpNATargetAddressOffset is the start of the Target Address
+ // field within an NDPNeighborAdvert.
+ ndpNATargetAddressOffset = 4
+
+ // ndpNAOptionsOffset is the start of the NDP options in an
+ // NDPNeighborAdvert.
+ ndpNAOptionsOffset = ndpNATargetAddressOffset + IPv6AddressSize
+
+ // ndpNAFlagsOffset is the offset of the flags within an
+ // NDPNeighborAdvert
+ ndpNAFlagsOffset = 0
+
+ // ndpNARouterFlagMask is the mask of the Router Flag field in
+ // the flags byte within in an NDPNeighborAdvert.
+ ndpNARouterFlagMask = (1 << 7)
+
+ // ndpNASolicitedFlagMask is the mask of the Solicited Flag field in
+ // the flags byte within in an NDPNeighborAdvert.
+ ndpNASolicitedFlagMask = (1 << 6)
+
+ // ndpNAOverrideFlagMask is the mask of the Override Flag field in
+ // the flags byte within in an NDPNeighborAdvert.
+ ndpNAOverrideFlagMask = (1 << 5)
+)
+
+// TargetAddress returns the value within the Target Address field.
+func (b NDPNeighborAdvert) TargetAddress() tcpip.Address {
+ return tcpip.Address(b[ndpNATargetAddressOffset:][:IPv6AddressSize])
+}
+
+// SetTargetAddress sets the value within the Target Address field.
+func (b NDPNeighborAdvert) SetTargetAddress(addr tcpip.Address) {
+ copy(b[ndpNATargetAddressOffset:][:IPv6AddressSize], addr)
+}
+
+// RouterFlag returns the value of the Router Flag field.
+func (b NDPNeighborAdvert) RouterFlag() bool {
+ return b[ndpNAFlagsOffset]&ndpNARouterFlagMask != 0
+}
+
+// SetRouterFlag sets the value in the Router Flag field.
+func (b NDPNeighborAdvert) SetRouterFlag(f bool) {
+ if f {
+ b[ndpNAFlagsOffset] |= ndpNARouterFlagMask
+ } else {
+ b[ndpNAFlagsOffset] &^= ndpNARouterFlagMask
+ }
+}
+
+// SolicitedFlag returns the value of the Solicited Flag field.
+func (b NDPNeighborAdvert) SolicitedFlag() bool {
+ return b[ndpNAFlagsOffset]&ndpNASolicitedFlagMask != 0
+}
+
+// SetSolicitedFlag sets the value in the Solicited Flag field.
+func (b NDPNeighborAdvert) SetSolicitedFlag(f bool) {
+ if f {
+ b[ndpNAFlagsOffset] |= ndpNASolicitedFlagMask
+ } else {
+ b[ndpNAFlagsOffset] &^= ndpNASolicitedFlagMask
+ }
+}
+
+// OverrideFlag returns the value of the Override Flag field.
+func (b NDPNeighborAdvert) OverrideFlag() bool {
+ return b[ndpNAFlagsOffset]&ndpNAOverrideFlagMask != 0
+}
+
+// SetOverrideFlag sets the value in the Override Flag field.
+func (b NDPNeighborAdvert) SetOverrideFlag(f bool) {
+ if f {
+ b[ndpNAFlagsOffset] |= ndpNAOverrideFlagMask
+ } else {
+ b[ndpNAFlagsOffset] &^= ndpNAOverrideFlagMask
+ }
+}
+
+// Options returns an NDPOptions of the the options body.
+func (b NDPNeighborAdvert) Options() NDPOptions {
+ return NDPOptions(b[ndpNAOptionsOffset:])
+}
diff --git a/pkg/tcpip/header/ndp_neighbor_solicit.go b/pkg/tcpip/header/ndp_neighbor_solicit.go
new file mode 100644
index 000000000..3a1b8e139
--- /dev/null
+++ b/pkg/tcpip/header/ndp_neighbor_solicit.go
@@ -0,0 +1,52 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package header
+
+import "gvisor.dev/gvisor/pkg/tcpip"
+
+// NDPNeighborSolicit is an NDP Neighbor Solicitation message. It will only
+// contain the body of an ICMPv6 packet.
+//
+// See RFC 4861 section 4.3 for more details.
+type NDPNeighborSolicit []byte
+
+const (
+ // NDPNSMinimumSize is the minimum size of a valid NDP Neighbor
+ // Solicitation message (body of an ICMPv6 packet).
+ NDPNSMinimumSize = 20
+
+ // ndpNSTargetAddessOffset is the start of the Target Address
+ // field within an NDPNeighborSolicit.
+ ndpNSTargetAddessOffset = 4
+
+ // ndpNSOptionsOffset is the start of the NDP options in an
+ // NDPNeighborSolicit.
+ ndpNSOptionsOffset = ndpNSTargetAddessOffset + IPv6AddressSize
+)
+
+// TargetAddress returns the value within the Target Address field.
+func (b NDPNeighborSolicit) TargetAddress() tcpip.Address {
+ return tcpip.Address(b[ndpNSTargetAddessOffset:][:IPv6AddressSize])
+}
+
+// SetTargetAddress sets the value within the Target Address field.
+func (b NDPNeighborSolicit) SetTargetAddress(addr tcpip.Address) {
+ copy(b[ndpNSTargetAddessOffset:][:IPv6AddressSize], addr)
+}
+
+// Options returns an NDPOptions of the the options body.
+func (b NDPNeighborSolicit) Options() NDPOptions {
+ return NDPOptions(b[ndpNSOptionsOffset:])
+}
diff --git a/pkg/tcpip/header/ndp_options.go b/pkg/tcpip/header/ndp_options.go
new file mode 100644
index 000000000..b28bde15b
--- /dev/null
+++ b/pkg/tcpip/header/ndp_options.go
@@ -0,0 +1,172 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package header
+
+import (
+ "gvisor.dev/gvisor/pkg/tcpip"
+)
+
+const (
+ // 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
+
+ // lengthByteUnits is the multiplier factor for the Length field of an
+ // NDP option. That is, the length field for NDP options is in units of
+ // 8 octets, as per RFC 4861 section 4.6.
+ lengthByteUnits = 8
+)
+
+// NDPOptions is a buffer of NDP options as defined by RFC 4861 section 4.6.
+type NDPOptions []byte
+
+// Serialize serializes the provided list of NDP options into o.
+//
+// Note, b must be of sufficient size to hold all the options in s. See
+// NDPOptionsSerializer.Length for details on the getting the total size
+// of a serialized NDPOptionsSerializer.
+//
+// Serialize may panic if b is not of sufficient size to hold all the options
+// in s.
+func (b NDPOptions) Serialize(s NDPOptionsSerializer) int {
+ done := 0
+
+ for _, o := range s {
+ l := paddedLength(o)
+
+ if l == 0 {
+ continue
+ }
+
+ b[0] = o.Type()
+
+ // We know this safe because paddedLength would have returned
+ // 0 if o had an invalid length (> 255 * lengthByteUnits).
+ b[1] = uint8(l / lengthByteUnits)
+
+ // Serialize NDP option body.
+ used := o.serializeInto(b[2:])
+
+ // Zero out remaining (padding) bytes, if any exists.
+ for i := used + 2; i < l; i++ {
+ b[i] = 0
+ }
+
+ b = b[l:]
+ done += l
+ }
+
+ return done
+}
+
+// ndpOption is the set of functions to be implemented by all NDP option types.
+type ndpOption interface {
+ // Type returns the type of this ndpOption.
+ Type() uint8
+
+ // Length returns the length of the body of this ndpOption, in bytes.
+ Length() int
+
+ // serializeInto serializes this ndpOption into the provided byte
+ // buffer.
+ //
+ // Note, the caller MUST provide a byte buffer with size of at least
+ // Length. Implementers of this function may assume that the byte buffer
+ // is of sufficient size. serializeInto MAY panic if the provided byte
+ // buffer is not of sufficient size.
+ //
+ // serializeInto will return the number of bytes that was used to
+ // serialize this ndpOption. Implementers must only use the number of
+ // bytes required to serialize this ndpOption. Callers MAY provide a
+ // larger buffer than required to serialize into.
+ serializeInto([]byte) int
+}
+
+// paddedLength returns the length of o, in bytes, with any padding bytes, if
+// required.
+func paddedLength(o ndpOption) int {
+ l := o.Length()
+
+ if l == 0 {
+ return 0
+ }
+
+ // Length excludes the 2 Type and Length bytes.
+ l += 2
+
+ // Add extra bytes if needed to make sure the option is
+ // lengthByteUnits-byte aligned. We do this by adding lengthByteUnits-1
+ // to l and then stripping off the last few LSBits from l. This will
+ // make sure that l is rounded up to the nearest unit of
+ // lengthByteUnits. This works since lengthByteUnits is a power of 2
+ // (= 8).
+ mask := lengthByteUnits - 1
+ l += mask
+ l &^= mask
+
+ if l/lengthByteUnits > 255 {
+ // Should never happen because an option can only have a max
+ // value of 255 for its Length field, so just return 0 so this
+ // option does not get serialized.
+ //
+ // Returning 0 here will make sure that this option does not get
+ // serialized when NDPOptions.Serialize is called with the
+ // NDPOptionsSerializer that holds this option, effectively
+ // skipping this option during serialization. Also note that
+ // a value of zero for the Length field in an NDP option is
+ // invalid so this is another sign to the caller that this NDP
+ // option is malformed, as per RFC 4861 section 4.6.
+ return 0
+ }
+
+ return l
+}
+
+// NDPOptionsSerializer is a serializer for NDP options.
+type NDPOptionsSerializer []ndpOption
+
+// Length returns the total number of bytes required to serialize.
+func (b NDPOptionsSerializer) Length() int {
+ l := 0
+
+ for _, o := range b {
+ l += paddedLength(o)
+ }
+
+ return l
+}
+
+// NDPTargetLinkLayerAddressOption is the NDP Target Link Layer Option
+// as defined by RFC 4861 section 4.6.1.
+type NDPTargetLinkLayerAddressOption tcpip.LinkAddress
+
+// Type implements ndpOption.Type.
+func (o NDPTargetLinkLayerAddressOption) Type() uint8 {
+ return NDPTargetLinkLayerAddressOptionType
+}
+
+// Length implements ndpOption.Length.
+func (o NDPTargetLinkLayerAddressOption) Length() int {
+ return len(o)
+}
+
+// serializeInto implements ndpOption.serializeInto.
+func (o NDPTargetLinkLayerAddressOption) serializeInto(b []byte) int {
+ return copy(b, o)
+}
diff --git a/pkg/tcpip/header/ndp_router_advert.go b/pkg/tcpip/header/ndp_router_advert.go
new file mode 100644
index 000000000..bf7610863
--- /dev/null
+++ b/pkg/tcpip/header/ndp_router_advert.go
@@ -0,0 +1,112 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package header
+
+import (
+ "encoding/binary"
+ "time"
+)
+
+// NDPRouterAdvert is an NDP Router Advertisement message. It will only contain
+// the body of an ICMPv6 packet.
+//
+// See RFC 4861 section 4.2 for more details.
+type NDPRouterAdvert []byte
+
+const (
+ // NDPRAMinimumSize is the minimum size of a valid NDP Router
+ // Advertisement message (body of an ICMPv6 packet).
+ NDPRAMinimumSize = 12
+
+ // ndpRACurrHopLimitOffset is the byte of the Curr Hop Limit field
+ // within an NDPRouterAdvert.
+ ndpRACurrHopLimitOffset = 0
+
+ // ndpRAFlagsOffset is the byte with the NDP RA bit-fields/flags
+ // within an NDPRouterAdvert.
+ ndpRAFlagsOffset = 1
+
+ // ndpRAManagedAddrConfFlagMask is the mask of the Managed Address
+ // Configuration flag within the bit-field/flags byte of an
+ // NDPRouterAdvert.
+ ndpRAManagedAddrConfFlagMask = (1 << 7)
+
+ // ndpRAOtherConfFlagMask is the mask of the Other Configuration flag
+ // within the bit-field/flags byte of an NDPRouterAdvert.
+ ndpRAOtherConfFlagMask = (1 << 6)
+
+ // ndpRARouterLifetimeOffset is the start of the 2-byte Router Lifetime
+ // field within an NDPRouterAdvert.
+ ndpRARouterLifetimeOffset = 2
+
+ // ndpRAReachableTimeOffset is the start of the 4-byte Reachable Time
+ // field within an NDPRouterAdvert.
+ ndpRAReachableTimeOffset = 4
+
+ // ndpRARetransTimerOffset is the start of the 4-byte Retrans Timer
+ // field within an NDPRouterAdvert.
+ ndpRARetransTimerOffset = 8
+
+ // ndpRAOptionsOffset is the start of the NDP options in an
+ // NDPRouterAdvert.
+ ndpRAOptionsOffset = 12
+)
+
+// CurrHopLimit returns the value of the Curr Hop Limit field.
+func (b NDPRouterAdvert) CurrHopLimit() uint8 {
+ return b[ndpRACurrHopLimitOffset]
+}
+
+// ManagedAddrConfFlag returns the value of the Managed Address Configuration
+// flag.
+func (b NDPRouterAdvert) ManagedAddrConfFlag() bool {
+ return b[ndpRAFlagsOffset]&ndpRAManagedAddrConfFlagMask != 0
+}
+
+// OtherConfFlag returns the value of the Other Configuration flag.
+func (b NDPRouterAdvert) OtherConfFlag() bool {
+ return b[ndpRAFlagsOffset]&ndpRAOtherConfFlagMask != 0
+}
+
+// RouterLifetime returns the lifetime associated with the default router. A
+// value of 0 means the source of the Router Advertisement is not a default
+// router and SHOULD NOT appear on the default router list. Note, a value of 0
+// only means that the router should not be used as a default router, it does
+// not apply to other information contained in the Router Advertisement.
+func (b NDPRouterAdvert) RouterLifetime() time.Duration {
+ // The field is the time in seconds, as per RFC 4861 section 4.2.
+ return time.Second * time.Duration(binary.BigEndian.Uint16(b[ndpRARouterLifetimeOffset:]))
+}
+
+// ReachableTime returns the time that a node assumes a neighbor is reachable
+// after having received a reachability confirmation. A value of 0 means
+// that it is unspecified by the source of the Router Advertisement message.
+func (b NDPRouterAdvert) ReachableTime() time.Duration {
+ // The field is the time in milliseconds, as per RFC 4861 section 4.2.
+ return time.Millisecond * time.Duration(binary.BigEndian.Uint32(b[ndpRAReachableTimeOffset:]))
+}
+
+// RetransTimer returns the time between retransmitted Neighbor Solicitation
+// messages. A value of 0 means that it is unspecified by the source of the
+// Router Advertisement message.
+func (b NDPRouterAdvert) RetransTimer() time.Duration {
+ // The field is the time in milliseconds, as per RFC 4861 section 4.2.
+ return time.Millisecond * time.Duration(binary.BigEndian.Uint32(b[ndpRARetransTimerOffset:]))
+}
+
+// Options returns an NDPOptions of the the options body.
+func (b NDPRouterAdvert) Options() NDPOptions {
+ return NDPOptions(b[ndpRAOptionsOffset:])
+}
diff --git a/pkg/tcpip/header/ndp_test.go b/pkg/tcpip/header/ndp_test.go
new file mode 100644
index 000000000..0aac14f43
--- /dev/null
+++ b/pkg/tcpip/header/ndp_test.go
@@ -0,0 +1,199 @@
+// Copyright 2019 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package header
+
+import (
+ "bytes"
+ "testing"
+ "time"
+
+ "gvisor.dev/gvisor/pkg/tcpip"
+)
+
+// TestNDPNeighborSolicit tests the functions of NDPNeighborSolicit.
+func TestNDPNeighborSolicit(t *testing.T) {
+ b := []byte{
+ 0, 0, 0, 0,
+ 1, 2, 3, 4,
+ 5, 6, 7, 8,
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ }
+
+ // Test getting the Target Address.
+ ns := NDPNeighborSolicit(b)
+ addr := tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10")
+ if got := ns.TargetAddress(); got != addr {
+ t.Fatalf("got ns.TargetAddress = %s, want %s", got, addr)
+ }
+
+ // Test updating the Target Address.
+ addr2 := tcpip.Address("\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x11")
+ ns.SetTargetAddress(addr2)
+ if got := ns.TargetAddress(); got != addr2 {
+ t.Fatalf("got ns.TargetAddress = %s, want %s", got, addr2)
+ }
+ // Make sure the address got updated in the backing buffer.
+ if got := tcpip.Address(b[ndpNSTargetAddessOffset:][:IPv6AddressSize]); got != addr2 {
+ t.Fatalf("got targetaddress buffer = %s, want %s", got, addr2)
+ }
+}
+
+// TestNDPNeighborAdvert tests the functions of NDPNeighborAdvert.
+func TestNDPNeighborAdvert(t *testing.T) {
+ b := []byte{
+ 160, 0, 0, 0,
+ 1, 2, 3, 4,
+ 5, 6, 7, 8,
+ 9, 10, 11, 12,
+ 13, 14, 15, 16,
+ }
+
+ // Test getting the Target Address.
+ na := NDPNeighborAdvert(b)
+ addr := tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10")
+ if got := na.TargetAddress(); got != addr {
+ t.Fatalf("got TargetAddress = %s, want %s", got, addr)
+ }
+
+ // Test getting the Router Flag.
+ if got := na.RouterFlag(); !got {
+ t.Fatalf("got RouterFlag = false, want = true")
+ }
+
+ // Test getting the Solicited Flag.
+ if got := na.SolicitedFlag(); got {
+ t.Fatalf("got SolicitedFlag = true, want = false")
+ }
+
+ // Test getting the Override Flag.
+ if got := na.OverrideFlag(); !got {
+ t.Fatalf("got OverrideFlag = false, want = true")
+ }
+
+ // Test updating the Target Address.
+ addr2 := tcpip.Address("\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x11")
+ na.SetTargetAddress(addr2)
+ if got := na.TargetAddress(); got != addr2 {
+ t.Fatalf("got TargetAddress = %s, want %s", got, addr2)
+ }
+ // Make sure the address got updated in the backing buffer.
+ if got := tcpip.Address(b[ndpNATargetAddressOffset:][:IPv6AddressSize]); got != addr2 {
+ t.Fatalf("got targetaddress buffer = %s, want %s", got, addr2)
+ }
+
+ // Test updating the Router Flag.
+ na.SetRouterFlag(false)
+ if got := na.RouterFlag(); got {
+ t.Fatalf("got RouterFlag = true, want = false")
+ }
+
+ // Test updating the Solicited Flag.
+ na.SetSolicitedFlag(true)
+ if got := na.SolicitedFlag(); !got {
+ t.Fatalf("got SolicitedFlag = false, want = true")
+ }
+
+ // Test updating the Override Flag.
+ na.SetOverrideFlag(false)
+ if got := na.OverrideFlag(); got {
+ t.Fatalf("got OverrideFlag = true, want = false")
+ }
+
+ // Make sure flags got updated in the backing buffer.
+ if got := b[ndpNAFlagsOffset]; got != 64 {
+ t.Fatalf("got flags byte = %d, want = 64")
+ }
+}
+
+func TestNDPRouterAdvert(t *testing.T) {
+ b := []byte{
+ 64, 128, 1, 2,
+ 3, 4, 5, 6,
+ 7, 8, 9, 10,
+ }
+
+ ra := NDPRouterAdvert(b)
+
+ if got := ra.CurrHopLimit(); got != 64 {
+ t.Fatalf("got ra.CurrHopLimit = %d, want = 64", got)
+ }
+
+ if got := ra.ManagedAddrConfFlag(); !got {
+ t.Fatalf("got ManagedAddrConfFlag = false, want = true")
+ }
+
+ if got := ra.OtherConfFlag(); got {
+ t.Fatalf("got OtherConfFlag = true, want = false")
+ }
+
+ if got, want := ra.RouterLifetime(), time.Second*258; got != want {
+ t.Fatalf("got ra.RouterLifetime = %d, want = %d", got, want)
+ }
+
+ if got, want := ra.ReachableTime(), time.Millisecond*50595078; got != want {
+ t.Fatalf("got ra.ReachableTime = %d, want = %d", got, want)
+ }
+
+ if got, want := ra.RetransTimer(), time.Millisecond*117967114; got != want {
+ t.Fatalf("got ra.RetransTimer = %d, want = %d", got, want)
+ }
+}
+
+// TestNDPTargetLinkLayerAddressOptionSerialize tests serializing a
+// NDPTargetLinkLayerAddressOption.
+func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) {
+ tests := []struct {
+ name string
+ buf []byte
+ expectedBuf []byte
+ addr tcpip.LinkAddress
+ }{
+ {
+ "Ethernet",
+ make([]byte, 8),
+ []byte{2, 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{2, 2, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0},
+ "\x01\x02\x03\x04\x05\x06\x07\x08",
+ },
+ {
+ "Empty",
+ []byte{},
+ []byte{},
+ "",
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ opts := NDPOptions(test.buf)
+ serializer := NDPOptionsSerializer{
+ NDPTargetLinkLayerAddressOption(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)
+ }
+ })
+ }
+}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-28 05:44:50 +0000