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-rw-r--r--pkg/tcpip/header/BUILD5
-rw-r--r--pkg/tcpip/header/icmpv4.go71
-rw-r--r--pkg/tcpip/header/icmpv6.go88
-rw-r--r--pkg/tcpip/header/ipv4.go35
-rw-r--r--pkg/tcpip/header/ipv6.go55
-rw-r--r--pkg/tcpip/header/udp.go5
6 files changed, 219 insertions, 40 deletions
diff --git a/pkg/tcpip/header/BUILD b/pkg/tcpip/header/BUILD
index 76ef02f13..a255231a3 100644
--- a/pkg/tcpip/header/BUILD
+++ b/pkg/tcpip/header/BUILD
@@ -1,6 +1,7 @@
-package(licenses = ["notice"])
+load("@io_bazel_rules_go//go:def.bzl", "go_test")
+load("//tools/go_stateify:defs.bzl", "go_library")
-load("//tools/go_stateify:defs.bzl", "go_library", "go_test")
+package(licenses = ["notice"])
go_library(
name = "header",
diff --git a/pkg/tcpip/header/icmpv4.go b/pkg/tcpip/header/icmpv4.go
index c52c0d851..0cac6c0a5 100644
--- a/pkg/tcpip/header/icmpv4.go
+++ b/pkg/tcpip/header/icmpv4.go
@@ -18,6 +18,7 @@ import (
"encoding/binary"
"gvisor.dev/gvisor/pkg/tcpip"
+ "gvisor.dev/gvisor/pkg/tcpip/buffer"
)
// ICMPv4 represents an ICMPv4 header stored in a byte array.
@@ -25,13 +26,29 @@ type ICMPv4 []byte
const (
// ICMPv4PayloadOffset defines the start of ICMP payload.
- ICMPv4PayloadOffset = 4
+ ICMPv4PayloadOffset = 8
// ICMPv4MinimumSize is the minimum size of a valid ICMP packet.
ICMPv4MinimumSize = 8
// ICMPv4ProtocolNumber is the ICMP transport protocol number.
ICMPv4ProtocolNumber tcpip.TransportProtocolNumber = 1
+
+ // icmpv4ChecksumOffset is the offset of the checksum field
+ // in an ICMPv4 message.
+ icmpv4ChecksumOffset = 2
+
+ // icmpv4MTUOffset is the offset of the MTU field
+ // in a ICMPv4FragmentationNeeded message.
+ icmpv4MTUOffset = 6
+
+ // icmpv4IdentOffset is the offset of the ident field
+ // in a ICMPv4EchoRequest/Reply message.
+ icmpv4IdentOffset = 4
+
+ // icmpv4SequenceOffset is the offset of the sequence field
+ // in a ICMPv4EchoRequest/Reply message.
+ icmpv4SequenceOffset = 6
)
// ICMPv4Type is the ICMP type field described in RFC 792.
@@ -72,12 +89,12 @@ func (b ICMPv4) SetCode(c byte) { b[1] = c }
// Checksum is the ICMP checksum field.
func (b ICMPv4) Checksum() uint16 {
- return binary.BigEndian.Uint16(b[2:])
+ return binary.BigEndian.Uint16(b[icmpv4ChecksumOffset:])
}
// SetChecksum sets the ICMP checksum field.
func (b ICMPv4) SetChecksum(checksum uint16) {
- binary.BigEndian.PutUint16(b[2:], checksum)
+ binary.BigEndian.PutUint16(b[icmpv4ChecksumOffset:], checksum)
}
// SourcePort implements Transport.SourcePort.
@@ -102,3 +119,51 @@ func (ICMPv4) SetDestinationPort(uint16) {
func (b ICMPv4) Payload() []byte {
return b[ICMPv4PayloadOffset:]
}
+
+// MTU retrieves the MTU field from an ICMPv4 message.
+func (b ICMPv4) MTU() uint16 {
+ return binary.BigEndian.Uint16(b[icmpv4MTUOffset:])
+}
+
+// SetMTU sets the MTU field from an ICMPv4 message.
+func (b ICMPv4) SetMTU(mtu uint16) {
+ binary.BigEndian.PutUint16(b[icmpv4MTUOffset:], mtu)
+}
+
+// Ident retrieves the Ident field from an ICMPv4 message.
+func (b ICMPv4) Ident() uint16 {
+ return binary.BigEndian.Uint16(b[icmpv4IdentOffset:])
+}
+
+// SetIdent sets the Ident field from an ICMPv4 message.
+func (b ICMPv4) SetIdent(ident uint16) {
+ binary.BigEndian.PutUint16(b[icmpv4IdentOffset:], ident)
+}
+
+// Sequence retrieves the Sequence field from an ICMPv4 message.
+func (b ICMPv4) Sequence() uint16 {
+ return binary.BigEndian.Uint16(b[icmpv4SequenceOffset:])
+}
+
+// SetSequence sets the Sequence field from an ICMPv4 message.
+func (b ICMPv4) SetSequence(sequence uint16) {
+ binary.BigEndian.PutUint16(b[icmpv4SequenceOffset:], sequence)
+}
+
+// ICMPv4Checksum calculates the ICMP checksum over the provided ICMP header,
+// and payload.
+func ICMPv4Checksum(h ICMPv4, vv buffer.VectorisedView) uint16 {
+ // Calculate the IPv6 pseudo-header upper-layer checksum.
+ xsum := uint16(0)
+ for _, v := range vv.Views() {
+ xsum = Checksum(v, xsum)
+ }
+
+ // h[2:4] is the checksum itself, set it aside to avoid checksumming the checksum.
+ h2, h3 := h[2], h[3]
+ h[2], h[3] = 0, 0
+ xsum = ^Checksum(h, xsum)
+ h[2], h[3] = h2, h3
+
+ return xsum
+}
diff --git a/pkg/tcpip/header/icmpv6.go b/pkg/tcpip/header/icmpv6.go
index 3cc57e234..1125a7d14 100644
--- a/pkg/tcpip/header/icmpv6.go
+++ b/pkg/tcpip/header/icmpv6.go
@@ -18,6 +18,7 @@ import (
"encoding/binary"
"gvisor.dev/gvisor/pkg/tcpip"
+ "gvisor.dev/gvisor/pkg/tcpip/buffer"
)
// ICMPv6 represents an ICMPv6 header stored in a byte array.
@@ -25,14 +26,18 @@ type ICMPv6 []byte
const (
// ICMPv6MinimumSize is the minimum size of a valid ICMP packet.
- ICMPv6MinimumSize = 4
+ ICMPv6MinimumSize = 8
+
+ // ICMPv6PayloadOffset is the offset of the payload in an
+ // ICMP packet.
+ ICMPv6PayloadOffset = 8
// ICMPv6ProtocolNumber is the ICMP transport protocol number.
ICMPv6ProtocolNumber tcpip.TransportProtocolNumber = 58
// ICMPv6NeighborSolicitMinimumSize is the minimum size of a
// neighbor solicitation packet.
- ICMPv6NeighborSolicitMinimumSize = ICMPv6MinimumSize + 4 + 16
+ ICMPv6NeighborSolicitMinimumSize = ICMPv6MinimumSize + 16
// ICMPv6NeighborAdvertSize is size of a neighbor advertisement.
ICMPv6NeighborAdvertSize = 32
@@ -42,11 +47,27 @@ const (
// ICMPv6DstUnreachableMinimumSize is the minimum size of a valid ICMP
// destination unreachable packet.
- ICMPv6DstUnreachableMinimumSize = ICMPv6MinimumSize + 4
+ ICMPv6DstUnreachableMinimumSize = ICMPv6MinimumSize
// ICMPv6PacketTooBigMinimumSize is the minimum size of a valid ICMP
// packet-too-big packet.
- ICMPv6PacketTooBigMinimumSize = ICMPv6MinimumSize + 4
+ ICMPv6PacketTooBigMinimumSize = ICMPv6MinimumSize
+
+ // icmpv6ChecksumOffset is the offset of the checksum field
+ // in an ICMPv6 message.
+ icmpv6ChecksumOffset = 2
+
+ // icmpv6MTUOffset is the offset of the MTU field in an ICMPv6
+ // PacketTooBig message.
+ icmpv6MTUOffset = 4
+
+ // icmpv6IdentOffset is the offset of the ident field
+ // in a ICMPv6 Echo Request/Reply message.
+ icmpv6IdentOffset = 4
+
+ // icmpv6SequenceOffset is the offset of the sequence field
+ // in a ICMPv6 Echo Request/Reply message.
+ icmpv6SequenceOffset = 6
)
// ICMPv6Type is the ICMP type field described in RFC 4443 and friends.
@@ -89,12 +110,12 @@ func (b ICMPv6) SetCode(c byte) { b[1] = c }
// Checksum is the ICMP checksum field.
func (b ICMPv6) Checksum() uint16 {
- return binary.BigEndian.Uint16(b[2:])
+ return binary.BigEndian.Uint16(b[icmpv6ChecksumOffset:])
}
// SetChecksum calculates and sets the ICMP checksum field.
func (b ICMPv6) SetChecksum(checksum uint16) {
- binary.BigEndian.PutUint16(b[2:], checksum)
+ binary.BigEndian.PutUint16(b[icmpv6ChecksumOffset:], checksum)
}
// SourcePort implements Transport.SourcePort.
@@ -115,7 +136,60 @@ func (ICMPv6) SetSourcePort(uint16) {
func (ICMPv6) SetDestinationPort(uint16) {
}
+// MTU retrieves the MTU field from an ICMPv6 message.
+func (b ICMPv6) MTU() uint32 {
+ return binary.BigEndian.Uint32(b[icmpv6MTUOffset:])
+}
+
+// SetMTU sets the MTU field from an ICMPv6 message.
+func (b ICMPv6) SetMTU(mtu uint32) {
+ binary.BigEndian.PutUint32(b[icmpv6MTUOffset:], mtu)
+}
+
+// Ident retrieves the Ident field from an ICMPv6 message.
+func (b ICMPv6) Ident() uint16 {
+ return binary.BigEndian.Uint16(b[icmpv6IdentOffset:])
+}
+
+// SetIdent sets the Ident field from an ICMPv6 message.
+func (b ICMPv6) SetIdent(ident uint16) {
+ binary.BigEndian.PutUint16(b[icmpv6IdentOffset:], ident)
+}
+
+// Sequence retrieves the Sequence field from an ICMPv6 message.
+func (b ICMPv6) Sequence() uint16 {
+ return binary.BigEndian.Uint16(b[icmpv6SequenceOffset:])
+}
+
+// SetSequence sets the Sequence field from an ICMPv6 message.
+func (b ICMPv6) SetSequence(sequence uint16) {
+ binary.BigEndian.PutUint16(b[icmpv6SequenceOffset:], sequence)
+}
+
// Payload implements Transport.Payload.
func (b ICMPv6) Payload() []byte {
- return b[ICMPv6MinimumSize:]
+ return b[ICMPv6PayloadOffset:]
+}
+
+// ICMPv6Checksum calculates the ICMP checksum over the provided ICMP header,
+// IPv6 src/dst addresses and the payload.
+func ICMPv6Checksum(h ICMPv6, src, dst tcpip.Address, vv buffer.VectorisedView) uint16 {
+ // Calculate the IPv6 pseudo-header upper-layer checksum.
+ xsum := Checksum([]byte(src), 0)
+ xsum = Checksum([]byte(dst), xsum)
+ var upperLayerLength [4]byte
+ binary.BigEndian.PutUint32(upperLayerLength[:], uint32(len(h)+vv.Size()))
+ xsum = Checksum(upperLayerLength[:], xsum)
+ xsum = Checksum([]byte{0, 0, 0, uint8(ICMPv6ProtocolNumber)}, xsum)
+ for _, v := range vv.Views() {
+ xsum = Checksum(v, xsum)
+ }
+
+ // h[2:4] is the checksum itself, set it aside to avoid checksumming the checksum.
+ h2, h3 := h[2], h[3]
+ h[2], h[3] = 0, 0
+ xsum = ^Checksum(h, xsum)
+ h[2], h[3] = h2, h3
+
+ return xsum
}
diff --git a/pkg/tcpip/header/ipv4.go b/pkg/tcpip/header/ipv4.go
index 17fc9c68e..e5360e7c1 100644
--- a/pkg/tcpip/header/ipv4.go
+++ b/pkg/tcpip/header/ipv4.go
@@ -21,16 +21,18 @@ import (
)
const (
- versIHL = 0
- tos = 1
- totalLen = 2
- id = 4
- flagsFO = 6
- ttl = 8
- protocol = 9
- checksum = 10
- srcAddr = 12
- dstAddr = 16
+ versIHL = 0
+ tos = 1
+ // IPv4TotalLenOffset is the offset of the total length field in the
+ // IPv4 header.
+ IPv4TotalLenOffset = 2
+ id = 4
+ flagsFO = 6
+ ttl = 8
+ protocol = 9
+ checksum = 10
+ srcAddr = 12
+ dstAddr = 16
)
// IPv4Fields contains the fields of an IPv4 packet. It is used to describe the
@@ -103,6 +105,11 @@ const (
// IPv4Any is the non-routable IPv4 "any" meta address.
IPv4Any tcpip.Address = "\x00\x00\x00\x00"
+
+ // IPv4MinimumProcessableDatagramSize is the minimum size of an IP
+ // packet that every IPv4 capable host must be able to
+ // process/reassemble.
+ IPv4MinimumProcessableDatagramSize = 576
)
// Flags that may be set in an IPv4 packet.
@@ -163,7 +170,7 @@ func (b IPv4) FragmentOffset() uint16 {
// TotalLength returns the "total length" field of the ipv4 header.
func (b IPv4) TotalLength() uint16 {
- return binary.BigEndian.Uint16(b[totalLen:])
+ return binary.BigEndian.Uint16(b[IPv4TotalLenOffset:])
}
// Checksum returns the checksum field of the ipv4 header.
@@ -209,7 +216,7 @@ func (b IPv4) SetTOS(v uint8, _ uint32) {
// SetTotalLength sets the "total length" field of the ipv4 header.
func (b IPv4) SetTotalLength(totalLength uint16) {
- binary.BigEndian.PutUint16(b[totalLen:], totalLength)
+ binary.BigEndian.PutUint16(b[IPv4TotalLenOffset:], totalLength)
}
// SetChecksum sets the checksum field of the ipv4 header.
@@ -265,7 +272,7 @@ func (b IPv4) Encode(i *IPv4Fields) {
// packets are produced.
func (b IPv4) EncodePartial(partialChecksum, totalLength uint16) {
b.SetTotalLength(totalLength)
- checksum := Checksum(b[totalLen:totalLen+2], partialChecksum)
+ checksum := Checksum(b[IPv4TotalLenOffset:IPv4TotalLenOffset+2], partialChecksum)
b.SetChecksum(^checksum)
}
@@ -277,7 +284,7 @@ func (b IPv4) IsValid(pktSize int) bool {
hlen := int(b.HeaderLength())
tlen := int(b.TotalLength())
- if hlen > tlen || tlen > pktSize {
+ if hlen < IPv4MinimumSize || hlen > tlen || tlen > pktSize {
return false
}
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go
index 31be42ce0..9d3abc0e4 100644
--- a/pkg/tcpip/header/ipv6.go
+++ b/pkg/tcpip/header/ipv6.go
@@ -22,12 +22,14 @@ import (
)
const (
- versTCFL = 0
- payloadLen = 4
- nextHdr = 6
- hopLimit = 7
- v6SrcAddr = 8
- v6DstAddr = 24
+ versTCFL = 0
+ // IPv6PayloadLenOffset is the offset of the PayloadLength field in
+ // IPv6 header.
+ IPv6PayloadLenOffset = 4
+ nextHdr = 6
+ hopLimit = 7
+ v6SrcAddr = 8
+ v6DstAddr = v6SrcAddr + IPv6AddressSize
)
// IPv6Fields contains the fields of an IPv6 packet. It is used to describe the
@@ -74,6 +76,13 @@ const (
// IPv6Version is the version of the ipv6 protocol.
IPv6Version = 6
+ // IPv6AllNodesMulticastAddress is a link-local multicast group that
+ // all IPv6 nodes MUST join, as per RFC 4291, section 2.8. Packets
+ // destined to this address will reach all nodes on a link.
+ //
+ // The address is ff02::1.
+ IPv6AllNodesMulticastAddress tcpip.Address = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01"
+
// IPv6MinimumMTU is the minimum MTU required by IPv6, per RFC 2460,
// section 5.
IPv6MinimumMTU = 1280
@@ -94,7 +103,7 @@ var IPv6EmptySubnet = func() tcpip.Subnet {
// PayloadLength returns the value of the "payload length" field of the ipv6
// header.
func (b IPv6) PayloadLength() uint16 {
- return binary.BigEndian.Uint16(b[payloadLen:])
+ return binary.BigEndian.Uint16(b[IPv6PayloadLenOffset:])
}
// HopLimit returns the value of the "hop limit" field of the ipv6 header.
@@ -119,13 +128,13 @@ func (b IPv6) Payload() []byte {
// SourceAddress returns the "source address" field of the ipv6 header.
func (b IPv6) SourceAddress() tcpip.Address {
- return tcpip.Address(b[v6SrcAddr : v6SrcAddr+IPv6AddressSize])
+ return tcpip.Address(b[v6SrcAddr:][:IPv6AddressSize])
}
// DestinationAddress returns the "destination address" field of the ipv6
// header.
func (b IPv6) DestinationAddress() tcpip.Address {
- return tcpip.Address(b[v6DstAddr : v6DstAddr+IPv6AddressSize])
+ return tcpip.Address(b[v6DstAddr:][:IPv6AddressSize])
}
// Checksum implements Network.Checksum. Given that IPv6 doesn't have a
@@ -148,18 +157,18 @@ func (b IPv6) SetTOS(t uint8, l uint32) {
// SetPayloadLength sets the "payload length" field of the ipv6 header.
func (b IPv6) SetPayloadLength(payloadLength uint16) {
- binary.BigEndian.PutUint16(b[payloadLen:], payloadLength)
+ binary.BigEndian.PutUint16(b[IPv6PayloadLenOffset:], payloadLength)
}
// SetSourceAddress sets the "source address" field of the ipv6 header.
func (b IPv6) SetSourceAddress(addr tcpip.Address) {
- copy(b[v6SrcAddr:v6SrcAddr+IPv6AddressSize], addr)
+ copy(b[v6SrcAddr:][:IPv6AddressSize], addr)
}
// SetDestinationAddress sets the "destination address" field of the ipv6
// header.
func (b IPv6) SetDestinationAddress(addr tcpip.Address) {
- copy(b[v6DstAddr:v6DstAddr+IPv6AddressSize], addr)
+ copy(b[v6DstAddr:][:IPv6AddressSize], addr)
}
// SetNextHeader sets the value of the "next header" field of the ipv6 header.
@@ -178,8 +187,8 @@ func (b IPv6) Encode(i *IPv6Fields) {
b.SetPayloadLength(i.PayloadLength)
b[nextHdr] = i.NextHeader
b[hopLimit] = i.HopLimit
- copy(b[v6SrcAddr:v6SrcAddr+IPv6AddressSize], i.SrcAddr)
- copy(b[v6DstAddr:v6DstAddr+IPv6AddressSize], i.DstAddr)
+ b.SetSourceAddress(i.SrcAddr)
+ b.SetDestinationAddress(i.DstAddr)
}
// IsValid performs basic validation on the packet.
@@ -219,6 +228,24 @@ func IsV6MulticastAddress(addr tcpip.Address) bool {
return addr[0] == 0xff
}
+// IsV6UnicastAddress determines if the provided address is a valid IPv6
+// unicast (and specified) address. That is, IsV6UnicastAddress returns
+// true if addr contains IPv6AddressSize bytes, is not the unspecified
+// address and is not a multicast address.
+func IsV6UnicastAddress(addr tcpip.Address) bool {
+ if len(addr) != IPv6AddressSize {
+ return false
+ }
+
+ // Must not be unspecified
+ if addr == IPv6Any {
+ return false
+ }
+
+ // Return if not a multicast.
+ return addr[0] != 0xff
+}
+
// SolicitedNodeAddr computes the solicited-node multicast address. This is
// used for NDP. Described in RFC 4291. The argument must be a full-length IPv6
// address.
diff --git a/pkg/tcpip/header/udp.go b/pkg/tcpip/header/udp.go
index c1f454805..74412c894 100644
--- a/pkg/tcpip/header/udp.go
+++ b/pkg/tcpip/header/udp.go
@@ -27,6 +27,11 @@ const (
udpChecksum = 6
)
+const (
+ // UDPMaximumPacketSize is the largest possible UDP packet.
+ UDPMaximumPacketSize = 0xffff
+)
+
// UDPFields contains the fields of a UDP packet. It is used to describe the
// fields of a packet that needs to be encoded.
type UDPFields struct {