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-rw-r--r--pkg/tcpip/header/BUILD12
-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/ipv6.go9
-rw-r--r--pkg/tcpip/header/ndp_neighbor_advert.go2
-rw-r--r--pkg/tcpip/header/ndp_neighbor_solicit.go2
-rw-r--r--pkg/tcpip/header/ndp_router_advert.go112
-rw-r--r--pkg/tcpip/header/ndp_test.go35
10 files changed, 448 insertions, 13 deletions
diff --git a/pkg/tcpip/header/BUILD b/pkg/tcpip/header/BUILD
index 07d09abed..a3485b35c 100644
--- a/pkg/tcpip/header/BUILD
+++ b/pkg/tcpip/header/BUILD
@@ -19,6 +19,7 @@ go_library(
"ndp_neighbor_advert.go",
"ndp_neighbor_solicit.go",
"ndp_options.go",
+ "ndp_router_advert.go",
"tcp.go",
"udp.go",
],
@@ -36,16 +37,23 @@ go_test(
name = "header_x_test",
size = "small",
srcs = [
+ "checksum_test.go",
"ipversion_test.go",
"tcp_test.go",
],
- deps = [":header"],
+ deps = [
+ ":header",
+ "//pkg/tcpip/buffer",
+ ],
)
go_test(
name = "header_test",
size = "small",
- srcs = ["ndp_test.go"],
+ 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/ipv6.go b/pkg/tcpip/header/ipv6.go
index b125bbea5..f1e60911b 100644
--- a/pkg/tcpip/header/ipv6.go
+++ b/pkg/tcpip/header/ipv6.go
@@ -101,6 +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
index 5c2b472c8..505c92668 100644
--- a/pkg/tcpip/header/ndp_neighbor_advert.go
+++ b/pkg/tcpip/header/ndp_neighbor_advert.go
@@ -18,6 +18,8 @@ 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 (
diff --git a/pkg/tcpip/header/ndp_neighbor_solicit.go b/pkg/tcpip/header/ndp_neighbor_solicit.go
index 1dcb0fbc6..3a1b8e139 100644
--- a/pkg/tcpip/header/ndp_neighbor_solicit.go
+++ b/pkg/tcpip/header/ndp_neighbor_solicit.go
@@ -18,6 +18,8 @@ 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 (
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
index a431a6e61..0aac14f43 100644
--- a/pkg/tcpip/header/ndp_test.go
+++ b/pkg/tcpip/header/ndp_test.go
@@ -17,6 +17,7 @@ package header
import (
"bytes"
"testing"
+ "time"
"gvisor.dev/gvisor/pkg/tcpip"
)
@@ -117,6 +118,40 @@ func TestNDPNeighborAdvert(t *testing.T) {
}
}
+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) {
generated by cgit v1.2.3 (git 2.39.1) at 2025-02-10 16:38:21 +0000