summaryrefslogtreecommitdiffhomepage
path: root/test/packetimpact/testbench/layers.go
diff options
context:
space:
mode:
Diffstat (limited to 'test/packetimpact/testbench/layers.go')
-rw-r--r--test/packetimpact/testbench/layers.go1234
1 files changed, 0 insertions, 1234 deletions
diff --git a/test/packetimpact/testbench/layers.go b/test/packetimpact/testbench/layers.go
deleted file mode 100644
index 49370377d..000000000
--- a/test/packetimpact/testbench/layers.go
+++ /dev/null
@@ -1,1234 +0,0 @@
-// Copyright 2020 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 testbench
-
-import (
- "encoding/hex"
- "fmt"
- "reflect"
- "strings"
-
- "github.com/google/go-cmp/cmp"
- "github.com/google/go-cmp/cmp/cmpopts"
- "go.uber.org/multierr"
- "gvisor.dev/gvisor/pkg/tcpip"
- "gvisor.dev/gvisor/pkg/tcpip/buffer"
- "gvisor.dev/gvisor/pkg/tcpip/header"
-)
-
-// Layer is the interface that all encapsulations must implement.
-//
-// A Layer is an encapsulation in a packet, such as TCP, IPv4, IPv6, etc. A
-// Layer contains all the fields of the encapsulation. Each field is a pointer
-// and may be nil.
-type Layer interface {
- fmt.Stringer
-
- // ToBytes converts the Layer into bytes. In places where the Layer's field
- // isn't nil, the value that is pointed to is used. When the field is nil, a
- // reasonable default for the Layer is used. For example, "64" for IPv4 TTL
- // and a calculated checksum for TCP or IP. Some layers require information
- // from the previous or next layers in order to compute a default, such as
- // TCP's checksum or Ethernet's type, so each Layer has a doubly-linked list
- // to the layer's neighbors.
- ToBytes() ([]byte, error)
-
- // match checks if the current Layer matches the provided Layer. If either
- // Layer has a nil in a given field, that field is considered matching.
- // Otherwise, the values pointed to by the fields must match. The LayerBase is
- // ignored.
- match(Layer) bool
-
- // length in bytes of the current encapsulation
- length() int
-
- // next gets a pointer to the encapsulated Layer.
- next() Layer
-
- // prev gets a pointer to the Layer encapsulating this one.
- Prev() Layer
-
- // setNext sets the pointer to the encapsulated Layer.
- setNext(Layer)
-
- // setPrev sets the pointer to the Layer encapsulating this one.
- setPrev(Layer)
-
- // merge overrides the values in the interface with the provided values.
- merge(Layer) error
-}
-
-// LayerBase is the common elements of all layers.
-type LayerBase struct {
- nextLayer Layer
- prevLayer Layer
-}
-
-func (lb *LayerBase) next() Layer {
- return lb.nextLayer
-}
-
-// Prev returns the previous layer.
-func (lb *LayerBase) Prev() Layer {
- return lb.prevLayer
-}
-
-func (lb *LayerBase) setNext(l Layer) {
- lb.nextLayer = l
-}
-
-func (lb *LayerBase) setPrev(l Layer) {
- lb.prevLayer = l
-}
-
-// equalLayer compares that two Layer structs match while ignoring field in
-// which either input has a nil and also ignoring the LayerBase of the inputs.
-func equalLayer(x, y Layer) bool {
- if x == nil || y == nil {
- return true
- }
- // opt ignores comparison pairs where either of the inputs is a nil.
- opt := cmp.FilterValues(func(x, y interface{}) bool {
- for _, l := range []interface{}{x, y} {
- v := reflect.ValueOf(l)
- if (v.Kind() == reflect.Ptr || v.Kind() == reflect.Slice) && v.IsNil() {
- return true
- }
- }
- return false
- }, cmp.Ignore())
- return cmp.Equal(x, y, opt, cmpopts.IgnoreTypes(LayerBase{}))
-}
-
-// mergeLayer merges y into x. Any fields for which y has a non-nil value, that
-// value overwrite the corresponding fields in x.
-func mergeLayer(x, y Layer) error {
- if y == nil {
- return nil
- }
- if reflect.TypeOf(x) != reflect.TypeOf(y) {
- return fmt.Errorf("can't merge %T into %T", y, x)
- }
- vx := reflect.ValueOf(x).Elem()
- vy := reflect.ValueOf(y).Elem()
- t := vy.Type()
- for i := 0; i < vy.NumField(); i++ {
- t := t.Field(i)
- if t.Anonymous {
- // Ignore the LayerBase in the Layer struct.
- continue
- }
- v := vy.Field(i)
- if v.IsNil() {
- continue
- }
- vx.Field(i).Set(v)
- }
- return nil
-}
-
-func stringLayer(l Layer) string {
- v := reflect.ValueOf(l).Elem()
- t := v.Type()
- var ret []string
- for i := 0; i < v.NumField(); i++ {
- t := t.Field(i)
- if t.Anonymous {
- // Ignore the LayerBase in the Layer struct.
- continue
- }
- v := v.Field(i)
- if v.IsNil() {
- continue
- }
- v = reflect.Indirect(v)
- if v.Kind() == reflect.Slice && v.Type().Elem().Kind() == reflect.Uint8 {
- ret = append(ret, fmt.Sprintf("%s:\n%v", t.Name, hex.Dump(v.Bytes())))
- } else {
- ret = append(ret, fmt.Sprintf("%s:%v", t.Name, v))
- }
- }
- return fmt.Sprintf("&%s{%s}", t, strings.Join(ret, " "))
-}
-
-// Ether can construct and match an ethernet encapsulation.
-type Ether struct {
- LayerBase
- SrcAddr *tcpip.LinkAddress
- DstAddr *tcpip.LinkAddress
- Type *tcpip.NetworkProtocolNumber
-}
-
-func (l *Ether) String() string {
- return stringLayer(l)
-}
-
-// ToBytes implements Layer.ToBytes.
-func (l *Ether) ToBytes() ([]byte, error) {
- b := make([]byte, header.EthernetMinimumSize)
- h := header.Ethernet(b)
- fields := &header.EthernetFields{}
- if l.SrcAddr != nil {
- fields.SrcAddr = *l.SrcAddr
- }
- if l.DstAddr != nil {
- fields.DstAddr = *l.DstAddr
- }
- if l.Type != nil {
- fields.Type = *l.Type
- } else {
- switch n := l.next().(type) {
- case *IPv4:
- fields.Type = header.IPv4ProtocolNumber
- case *IPv6:
- fields.Type = header.IPv6ProtocolNumber
- default:
- return nil, fmt.Errorf("ethernet header's next layer is unrecognized: %#v", n)
- }
- }
- h.Encode(fields)
- return h, nil
-}
-
-// LinkAddress is a helper routine that allocates a new tcpip.LinkAddress value
-// to store v and returns a pointer to it.
-func LinkAddress(v tcpip.LinkAddress) *tcpip.LinkAddress {
- return &v
-}
-
-// NetworkProtocolNumber is a helper routine that allocates a new
-// tcpip.NetworkProtocolNumber value to store v and returns a pointer to it.
-func NetworkProtocolNumber(v tcpip.NetworkProtocolNumber) *tcpip.NetworkProtocolNumber {
- return &v
-}
-
-// layerParser parses the input bytes and returns a Layer along with the next
-// layerParser to run. If there is no more parsing to do, the returned
-// layerParser is nil.
-type layerParser func([]byte) (Layer, layerParser)
-
-// parse parses bytes starting with the first layerParser and using successive
-// layerParsers until all the bytes are parsed.
-func parse(parser layerParser, b []byte) Layers {
- var layers Layers
- for {
- var layer Layer
- layer, parser = parser(b)
- layers = append(layers, layer)
- if parser == nil {
- break
- }
- b = b[layer.length():]
- }
- layers.linkLayers()
- return layers
-}
-
-// parseEther parses the bytes assuming that they start with an ethernet header
-// and continues parsing further encapsulations.
-func parseEther(b []byte) (Layer, layerParser) {
- h := header.Ethernet(b)
- ether := Ether{
- SrcAddr: LinkAddress(h.SourceAddress()),
- DstAddr: LinkAddress(h.DestinationAddress()),
- Type: NetworkProtocolNumber(h.Type()),
- }
- var nextParser layerParser
- switch h.Type() {
- case header.IPv4ProtocolNumber:
- nextParser = parseIPv4
- case header.IPv6ProtocolNumber:
- nextParser = parseIPv6
- default:
- // Assume that the rest is a payload.
- nextParser = parsePayload
- }
- return &ether, nextParser
-}
-
-func (l *Ether) match(other Layer) bool {
- return equalLayer(l, other)
-}
-
-func (l *Ether) length() int {
- return header.EthernetMinimumSize
-}
-
-// merge implements Layer.merge.
-func (l *Ether) merge(other Layer) error {
- return mergeLayer(l, other)
-}
-
-// IPv4 can construct and match an IPv4 encapsulation.
-type IPv4 struct {
- LayerBase
- IHL *uint8
- TOS *uint8
- TotalLength *uint16
- ID *uint16
- Flags *uint8
- FragmentOffset *uint16
- TTL *uint8
- Protocol *uint8
- Checksum *uint16
- SrcAddr *tcpip.Address
- DstAddr *tcpip.Address
-}
-
-func (l *IPv4) String() string {
- return stringLayer(l)
-}
-
-// ToBytes implements Layer.ToBytes.
-func (l *IPv4) ToBytes() ([]byte, error) {
- b := make([]byte, header.IPv4MinimumSize)
- h := header.IPv4(b)
- fields := &header.IPv4Fields{
- IHL: 20,
- TOS: 0,
- TotalLength: 0,
- ID: 0,
- Flags: 0,
- FragmentOffset: 0,
- TTL: 64,
- Protocol: 0,
- Checksum: 0,
- SrcAddr: tcpip.Address(""),
- DstAddr: tcpip.Address(""),
- }
- if l.TOS != nil {
- fields.TOS = *l.TOS
- }
- if l.TotalLength != nil {
- fields.TotalLength = *l.TotalLength
- } else {
- fields.TotalLength = uint16(l.length())
- current := l.next()
- for current != nil {
- fields.TotalLength += uint16(current.length())
- current = current.next()
- }
- }
- if l.ID != nil {
- fields.ID = *l.ID
- }
- if l.Flags != nil {
- fields.Flags = *l.Flags
- }
- if l.FragmentOffset != nil {
- fields.FragmentOffset = *l.FragmentOffset
- }
- if l.TTL != nil {
- fields.TTL = *l.TTL
- }
- if l.Protocol != nil {
- fields.Protocol = *l.Protocol
- } else {
- switch n := l.next().(type) {
- case *TCP:
- fields.Protocol = uint8(header.TCPProtocolNumber)
- case *UDP:
- fields.Protocol = uint8(header.UDPProtocolNumber)
- case *ICMPv4:
- fields.Protocol = uint8(header.ICMPv4ProtocolNumber)
- default:
- // TODO(b/150301488): Support more protocols as needed.
- return nil, fmt.Errorf("ipv4 header's next layer is unrecognized: %#v", n)
- }
- }
- if l.SrcAddr != nil {
- fields.SrcAddr = *l.SrcAddr
- }
- if l.DstAddr != nil {
- fields.DstAddr = *l.DstAddr
- }
- if l.Checksum != nil {
- fields.Checksum = *l.Checksum
- }
- h.Encode(fields)
- if l.Checksum == nil {
- h.SetChecksum(^h.CalculateChecksum())
- }
- return h, nil
-}
-
-// Uint16 is a helper routine that allocates a new
-// uint16 value to store v and returns a pointer to it.
-func Uint16(v uint16) *uint16 {
- return &v
-}
-
-// Uint8 is a helper routine that allocates a new
-// uint8 value to store v and returns a pointer to it.
-func Uint8(v uint8) *uint8 {
- return &v
-}
-
-// Address is a helper routine that allocates a new tcpip.Address value to store
-// v and returns a pointer to it.
-func Address(v tcpip.Address) *tcpip.Address {
- return &v
-}
-
-// parseIPv4 parses the bytes assuming that they start with an ipv4 header and
-// continues parsing further encapsulations.
-func parseIPv4(b []byte) (Layer, layerParser) {
- h := header.IPv4(b)
- tos, _ := h.TOS()
- ipv4 := IPv4{
- IHL: Uint8(h.HeaderLength()),
- TOS: &tos,
- TotalLength: Uint16(h.TotalLength()),
- ID: Uint16(h.ID()),
- Flags: Uint8(h.Flags()),
- FragmentOffset: Uint16(h.FragmentOffset()),
- TTL: Uint8(h.TTL()),
- Protocol: Uint8(h.Protocol()),
- Checksum: Uint16(h.Checksum()),
- SrcAddr: Address(h.SourceAddress()),
- DstAddr: Address(h.DestinationAddress()),
- }
- var nextParser layerParser
- switch h.TransportProtocol() {
- case header.TCPProtocolNumber:
- nextParser = parseTCP
- case header.UDPProtocolNumber:
- nextParser = parseUDP
- case header.ICMPv4ProtocolNumber:
- nextParser = parseICMPv4
- default:
- // Assume that the rest is a payload.
- nextParser = parsePayload
- }
- return &ipv4, nextParser
-}
-
-func (l *IPv4) match(other Layer) bool {
- return equalLayer(l, other)
-}
-
-func (l *IPv4) length() int {
- if l.IHL == nil {
- return header.IPv4MinimumSize
- }
- return int(*l.IHL)
-}
-
-// merge implements Layer.merge.
-func (l *IPv4) merge(other Layer) error {
- return mergeLayer(l, other)
-}
-
-// IPv6 can construct and match an IPv6 encapsulation.
-type IPv6 struct {
- LayerBase
- TrafficClass *uint8
- FlowLabel *uint32
- PayloadLength *uint16
- NextHeader *uint8
- HopLimit *uint8
- SrcAddr *tcpip.Address
- DstAddr *tcpip.Address
-}
-
-func (l *IPv6) String() string {
- return stringLayer(l)
-}
-
-// ToBytes implements Layer.ToBytes.
-func (l *IPv6) ToBytes() ([]byte, error) {
- b := make([]byte, header.IPv6MinimumSize)
- h := header.IPv6(b)
- fields := &header.IPv6Fields{
- HopLimit: 64,
- }
- if l.TrafficClass != nil {
- fields.TrafficClass = *l.TrafficClass
- }
- if l.FlowLabel != nil {
- fields.FlowLabel = *l.FlowLabel
- }
- if l.PayloadLength != nil {
- fields.PayloadLength = *l.PayloadLength
- } else {
- for current := l.next(); current != nil; current = current.next() {
- fields.PayloadLength += uint16(current.length())
- }
- }
- if l.NextHeader != nil {
- fields.NextHeader = *l.NextHeader
- } else {
- switch n := l.next().(type) {
- case *TCP:
- fields.NextHeader = uint8(header.TCPProtocolNumber)
- case *UDP:
- fields.NextHeader = uint8(header.UDPProtocolNumber)
- case *ICMPv6:
- fields.NextHeader = uint8(header.ICMPv6ProtocolNumber)
- default:
- // TODO(b/150301488): Support more protocols as needed.
- return nil, fmt.Errorf("ToBytes can't deduce the IPv6 header's next protocol: %#v", n)
- }
- }
- if l.HopLimit != nil {
- fields.HopLimit = *l.HopLimit
- }
- if l.SrcAddr != nil {
- fields.SrcAddr = *l.SrcAddr
- }
- if l.DstAddr != nil {
- fields.DstAddr = *l.DstAddr
- }
- h.Encode(fields)
- return h, nil
-}
-
-// parseIPv6 parses the bytes assuming that they start with an ipv6 header and
-// continues parsing further encapsulations.
-func parseIPv6(b []byte) (Layer, layerParser) {
- h := header.IPv6(b)
- tos, flowLabel := h.TOS()
- ipv6 := IPv6{
- TrafficClass: &tos,
- FlowLabel: &flowLabel,
- PayloadLength: Uint16(h.PayloadLength()),
- NextHeader: Uint8(h.NextHeader()),
- HopLimit: Uint8(h.HopLimit()),
- SrcAddr: Address(h.SourceAddress()),
- DstAddr: Address(h.DestinationAddress()),
- }
- var nextParser layerParser
- switch h.TransportProtocol() {
- case header.TCPProtocolNumber:
- nextParser = parseTCP
- case header.UDPProtocolNumber:
- nextParser = parseUDP
- case header.ICMPv6ProtocolNumber:
- nextParser = parseICMPv6
- default:
- // Assume that the rest is a payload.
- nextParser = parsePayload
- }
- return &ipv6, nextParser
-}
-
-func (l *IPv6) match(other Layer) bool {
- return equalLayer(l, other)
-}
-
-func (l *IPv6) length() int {
- return header.IPv6MinimumSize
-}
-
-// merge overrides the values in l with the values from other but only in fields
-// where the value is not nil.
-func (l *IPv6) merge(other Layer) error {
- return mergeLayer(l, other)
-}
-
-// ICMPv6 can construct and match an ICMPv6 encapsulation.
-type ICMPv6 struct {
- LayerBase
- Type *header.ICMPv6Type
- Code *byte
- Checksum *uint16
- NDPPayload []byte
-}
-
-func (l *ICMPv6) String() string {
- // TODO(eyalsoha): Do something smarter here when *l.Type is ParameterProblem?
- // We could parse the contents of the Payload as if it were an IPv6 packet.
- return stringLayer(l)
-}
-
-// ToBytes implements Layer.ToBytes.
-func (l *ICMPv6) ToBytes() ([]byte, error) {
- b := make([]byte, header.ICMPv6HeaderSize+len(l.NDPPayload))
- h := header.ICMPv6(b)
- if l.Type != nil {
- h.SetType(*l.Type)
- }
- if l.Code != nil {
- h.SetCode(*l.Code)
- }
- copy(h.NDPPayload(), l.NDPPayload)
- if l.Checksum != nil {
- h.SetChecksum(*l.Checksum)
- } else {
- ipv6 := l.Prev().(*IPv6)
- h.SetChecksum(header.ICMPv6Checksum(h, *ipv6.SrcAddr, *ipv6.DstAddr, buffer.VectorisedView{}))
- }
- return h, nil
-}
-
-// ICMPv6Type is a helper routine that allocates a new ICMPv6Type value to store
-// v and returns a pointer to it.
-func ICMPv6Type(v header.ICMPv6Type) *header.ICMPv6Type {
- return &v
-}
-
-// Byte is a helper routine that allocates a new byte value to store
-// v and returns a pointer to it.
-func Byte(v byte) *byte {
- return &v
-}
-
-// parseICMPv6 parses the bytes assuming that they start with an ICMPv6 header.
-func parseICMPv6(b []byte) (Layer, layerParser) {
- h := header.ICMPv6(b)
- icmpv6 := ICMPv6{
- Type: ICMPv6Type(h.Type()),
- Code: Byte(h.Code()),
- Checksum: Uint16(h.Checksum()),
- NDPPayload: h.NDPPayload(),
- }
- return &icmpv6, nil
-}
-
-func (l *ICMPv6) match(other Layer) bool {
- return equalLayer(l, other)
-}
-
-func (l *ICMPv6) length() int {
- return header.ICMPv6HeaderSize + len(l.NDPPayload)
-}
-
-// merge overrides the values in l with the values from other but only in fields
-// where the value is not nil.
-func (l *ICMPv6) merge(other Layer) error {
- return mergeLayer(l, other)
-}
-
-// ICMPv4Type is a helper routine that allocates a new header.ICMPv4Type value
-// to store t and returns a pointer to it.
-func ICMPv4Type(t header.ICMPv4Type) *header.ICMPv4Type {
- return &t
-}
-
-// ICMPv4 can construct and match an ICMPv4 encapsulation.
-type ICMPv4 struct {
- LayerBase
- Type *header.ICMPv4Type
- Code *uint8
- Checksum *uint16
-}
-
-func (l *ICMPv4) String() string {
- return stringLayer(l)
-}
-
-// ToBytes implements Layer.ToBytes.
-func (l *ICMPv4) ToBytes() ([]byte, error) {
- b := make([]byte, header.ICMPv4MinimumSize)
- h := header.ICMPv4(b)
- if l.Type != nil {
- h.SetType(*l.Type)
- }
- if l.Code != nil {
- h.SetCode(byte(*l.Code))
- }
- if l.Checksum != nil {
- h.SetChecksum(*l.Checksum)
- return h, nil
- }
- payload, err := payload(l)
- if err != nil {
- return nil, err
- }
- h.SetChecksum(header.ICMPv4Checksum(h, payload))
- return h, nil
-}
-
-// parseICMPv4 parses the bytes as an ICMPv4 header, returning a Layer and a
-// parser for the encapsulated payload.
-func parseICMPv4(b []byte) (Layer, layerParser) {
- h := header.ICMPv4(b)
- icmpv4 := ICMPv4{
- Type: ICMPv4Type(h.Type()),
- Code: Uint8(h.Code()),
- Checksum: Uint16(h.Checksum()),
- }
- return &icmpv4, parsePayload
-}
-
-func (l *ICMPv4) match(other Layer) bool {
- return equalLayer(l, other)
-}
-
-func (l *ICMPv4) length() int {
- return header.ICMPv4MinimumSize
-}
-
-// merge overrides the values in l with the values from other but only in fields
-// where the value is not nil.
-func (l *ICMPv4) merge(other Layer) error {
- return mergeLayer(l, other)
-}
-
-// TCP can construct and match a TCP encapsulation.
-type TCP struct {
- LayerBase
- SrcPort *uint16
- DstPort *uint16
- SeqNum *uint32
- AckNum *uint32
- DataOffset *uint8
- Flags *uint8
- WindowSize *uint16
- Checksum *uint16
- UrgentPointer *uint16
-}
-
-func (l *TCP) String() string {
- return stringLayer(l)
-}
-
-// ToBytes implements Layer.ToBytes.
-func (l *TCP) ToBytes() ([]byte, error) {
- b := make([]byte, header.TCPMinimumSize)
- h := header.TCP(b)
- if l.SrcPort != nil {
- h.SetSourcePort(*l.SrcPort)
- }
- if l.DstPort != nil {
- h.SetDestinationPort(*l.DstPort)
- }
- if l.SeqNum != nil {
- h.SetSequenceNumber(*l.SeqNum)
- }
- if l.AckNum != nil {
- h.SetAckNumber(*l.AckNum)
- }
- if l.DataOffset != nil {
- h.SetDataOffset(*l.DataOffset)
- } else {
- h.SetDataOffset(uint8(l.length()))
- }
- if l.Flags != nil {
- h.SetFlags(*l.Flags)
- }
- if l.WindowSize != nil {
- h.SetWindowSize(*l.WindowSize)
- } else {
- h.SetWindowSize(32768)
- }
- if l.UrgentPointer != nil {
- h.SetUrgentPoiner(*l.UrgentPointer)
- }
- if l.Checksum != nil {
- h.SetChecksum(*l.Checksum)
- return h, nil
- }
- if err := setTCPChecksum(&h, l); err != nil {
- return nil, err
- }
- return h, nil
-}
-
-// totalLength returns the length of the provided layer and all following
-// layers.
-func totalLength(l Layer) int {
- var totalLength int
- for ; l != nil; l = l.next() {
- totalLength += l.length()
- }
- return totalLength
-}
-
-// payload returns a buffer.VectorisedView of l's payload.
-func payload(l Layer) (buffer.VectorisedView, error) {
- var payloadBytes buffer.VectorisedView
- for current := l.next(); current != nil; current = current.next() {
- payload, err := current.ToBytes()
- if err != nil {
- return buffer.VectorisedView{}, fmt.Errorf("can't get bytes for next header: %s", payload)
- }
- payloadBytes.AppendView(payload)
- }
- return payloadBytes, nil
-}
-
-// layerChecksum calculates the checksum of the Layer header, including the
-// peusdeochecksum of the layer before it and all the bytes after it.
-func layerChecksum(l Layer, protoNumber tcpip.TransportProtocolNumber) (uint16, error) {
- totalLength := uint16(totalLength(l))
- var xsum uint16
- switch s := l.Prev().(type) {
- case *IPv4:
- xsum = header.PseudoHeaderChecksum(protoNumber, *s.SrcAddr, *s.DstAddr, totalLength)
- default:
- // TODO(b/150301488): Support more protocols, like IPv6.
- return 0, fmt.Errorf("can't get src and dst addr from previous layer: %#v", s)
- }
- payloadBytes, err := payload(l)
- if err != nil {
- return 0, err
- }
- xsum = header.ChecksumVV(payloadBytes, xsum)
- return xsum, nil
-}
-
-// setTCPChecksum calculates the checksum of the TCP header and sets it in h.
-func setTCPChecksum(h *header.TCP, tcp *TCP) error {
- h.SetChecksum(0)
- xsum, err := layerChecksum(tcp, header.TCPProtocolNumber)
- if err != nil {
- return err
- }
- h.SetChecksum(^h.CalculateChecksum(xsum))
- return nil
-}
-
-// Uint32 is a helper routine that allocates a new
-// uint32 value to store v and returns a pointer to it.
-func Uint32(v uint32) *uint32 {
- return &v
-}
-
-// parseTCP parses the bytes assuming that they start with a tcp header and
-// continues parsing further encapsulations.
-func parseTCP(b []byte) (Layer, layerParser) {
- h := header.TCP(b)
- tcp := TCP{
- SrcPort: Uint16(h.SourcePort()),
- DstPort: Uint16(h.DestinationPort()),
- SeqNum: Uint32(h.SequenceNumber()),
- AckNum: Uint32(h.AckNumber()),
- DataOffset: Uint8(h.DataOffset()),
- Flags: Uint8(h.Flags()),
- WindowSize: Uint16(h.WindowSize()),
- Checksum: Uint16(h.Checksum()),
- UrgentPointer: Uint16(h.UrgentPointer()),
- }
- return &tcp, parsePayload
-}
-
-func (l *TCP) match(other Layer) bool {
- return equalLayer(l, other)
-}
-
-func (l *TCP) length() int {
- if l.DataOffset == nil {
- return header.TCPMinimumSize
- }
- return int(*l.DataOffset)
-}
-
-// merge implements Layer.merge.
-func (l *TCP) merge(other Layer) error {
- return mergeLayer(l, other)
-}
-
-// UDP can construct and match a UDP encapsulation.
-type UDP struct {
- LayerBase
- SrcPort *uint16
- DstPort *uint16
- Length *uint16
- Checksum *uint16
-}
-
-func (l *UDP) String() string {
- return stringLayer(l)
-}
-
-// ToBytes implements Layer.ToBytes.
-func (l *UDP) ToBytes() ([]byte, error) {
- b := make([]byte, header.UDPMinimumSize)
- h := header.UDP(b)
- if l.SrcPort != nil {
- h.SetSourcePort(*l.SrcPort)
- }
- if l.DstPort != nil {
- h.SetDestinationPort(*l.DstPort)
- }
- if l.Length != nil {
- h.SetLength(*l.Length)
- } else {
- h.SetLength(uint16(totalLength(l)))
- }
- if l.Checksum != nil {
- h.SetChecksum(*l.Checksum)
- return h, nil
- }
- if err := setUDPChecksum(&h, l); err != nil {
- return nil, err
- }
- return h, nil
-}
-
-// setUDPChecksum calculates the checksum of the UDP header and sets it in h.
-func setUDPChecksum(h *header.UDP, udp *UDP) error {
- h.SetChecksum(0)
- xsum, err := layerChecksum(udp, header.UDPProtocolNumber)
- if err != nil {
- return err
- }
- h.SetChecksum(^h.CalculateChecksum(xsum))
- return nil
-}
-
-// parseUDP parses the bytes assuming that they start with a udp header and
-// returns the parsed layer and the next parser to use.
-func parseUDP(b []byte) (Layer, layerParser) {
- h := header.UDP(b)
- udp := UDP{
- SrcPort: Uint16(h.SourcePort()),
- DstPort: Uint16(h.DestinationPort()),
- Length: Uint16(h.Length()),
- Checksum: Uint16(h.Checksum()),
- }
- return &udp, parsePayload
-}
-
-func (l *UDP) match(other Layer) bool {
- return equalLayer(l, other)
-}
-
-func (l *UDP) length() int {
- return header.UDPMinimumSize
-}
-
-// merge implements Layer.merge.
-func (l *UDP) merge(other Layer) error {
- return mergeLayer(l, other)
-}
-
-// Payload has bytes beyond OSI layer 4.
-type Payload struct {
- LayerBase
- Bytes []byte
-}
-
-func (l *Payload) String() string {
- return stringLayer(l)
-}
-
-// parsePayload parses the bytes assuming that they start with a payload and
-// continue to the end. There can be no further encapsulations.
-func parsePayload(b []byte) (Layer, layerParser) {
- payload := Payload{
- Bytes: b,
- }
- return &payload, nil
-}
-
-// ToBytes implements Layer.ToBytes.
-func (l *Payload) ToBytes() ([]byte, error) {
- return l.Bytes, nil
-}
-
-func (l *Payload) match(other Layer) bool {
- return equalLayer(l, other)
-}
-
-func (l *Payload) length() int {
- return len(l.Bytes)
-}
-
-// merge implements Layer.merge.
-func (l *Payload) merge(other Layer) error {
- return mergeLayer(l, other)
-}
-
-// Layers is an array of Layer and supports similar functions to Layer.
-type Layers []Layer
-
-// linkLayers sets the linked-list ponters in ls.
-func (ls *Layers) linkLayers() {
- for i, l := range *ls {
- if i > 0 {
- l.setPrev((*ls)[i-1])
- } else {
- l.setPrev(nil)
- }
- if i+1 < len(*ls) {
- l.setNext((*ls)[i+1])
- } else {
- l.setNext(nil)
- }
- }
-}
-
-// ToBytes converts the Layers into bytes. It creates a linked list of the Layer
-// structs and then concatentates the output of ToBytes on each Layer.
-func (ls *Layers) ToBytes() ([]byte, error) {
- ls.linkLayers()
- outBytes := []byte{}
- for _, l := range *ls {
- layerBytes, err := l.ToBytes()
- if err != nil {
- return nil, err
- }
- outBytes = append(outBytes, layerBytes...)
- }
- return outBytes, nil
-}
-
-func (ls *Layers) match(other Layers) bool {
- if len(*ls) > len(other) {
- return false
- }
- for i, l := range *ls {
- if !equalLayer(l, other[i]) {
- return false
- }
- }
- return true
-}
-
-// layerDiff stores the diffs for each field along with the label for the Layer.
-// If rows is nil, that means that there was no diff.
-type layerDiff struct {
- label string
- rows []layerDiffRow
-}
-
-// layerDiffRow stores the fields and corresponding values for two got and want
-// layers. If the value was nil then the string stored is the empty string.
-type layerDiffRow struct {
- field, got, want string
-}
-
-// diffLayer extracts all differing fields between two layers.
-func diffLayer(got, want Layer) []layerDiffRow {
- vGot := reflect.ValueOf(got).Elem()
- vWant := reflect.ValueOf(want).Elem()
- if vGot.Type() != vWant.Type() {
- return nil
- }
- t := vGot.Type()
- var result []layerDiffRow
- for i := 0; i < t.NumField(); i++ {
- t := t.Field(i)
- if t.Anonymous {
- // Ignore the LayerBase in the Layer struct.
- continue
- }
- vGot := vGot.Field(i)
- vWant := vWant.Field(i)
- gotString := ""
- if !vGot.IsNil() {
- gotString = fmt.Sprint(reflect.Indirect(vGot))
- }
- wantString := ""
- if !vWant.IsNil() {
- wantString = fmt.Sprint(reflect.Indirect(vWant))
- }
- result = append(result, layerDiffRow{t.Name, gotString, wantString})
- }
- return result
-}
-
-// layerType returns a concise string describing the type of the Layer, like
-// "TCP", or "IPv6".
-func layerType(l Layer) string {
- return reflect.TypeOf(l).Elem().Name()
-}
-
-// diff compares Layers and returns a representation of the difference. Each
-// Layer in the Layers is pairwise compared. If an element in either is nil, it
-// is considered a match with the other Layer. If two Layers have differing
-// types, they don't match regardless of the contents. If two Layers have the
-// same type then the fields in the Layer are pairwise compared. Fields that are
-// nil always match. Two non-nil fields only match if they point to equal
-// values. diff returns an empty string if and only if *ls and other match.
-func (ls *Layers) diff(other Layers) string {
- var allDiffs []layerDiff
- // Check the cases where one list is longer than the other, where one or both
- // elements are nil, where the sides have different types, and where the sides
- // have the same type.
- for i := 0; i < len(*ls) || i < len(other); i++ {
- if i >= len(*ls) {
- // Matching ls against other where other is longer than ls. missing
- // matches everything so we just include a label without any rows. Having
- // no rows is a sign that there was no diff.
- allDiffs = append(allDiffs, layerDiff{
- label: "missing matches " + layerType(other[i]),
- })
- continue
- }
-
- if i >= len(other) {
- // Matching ls against other where ls is longer than other. missing
- // matches everything so we just include a label without any rows. Having
- // no rows is a sign that there was no diff.
- allDiffs = append(allDiffs, layerDiff{
- label: layerType((*ls)[i]) + " matches missing",
- })
- continue
- }
-
- if (*ls)[i] == nil && other[i] == nil {
- // Matching ls against other where both elements are nil. nil matches
- // everything so we just include a label without any rows. Having no rows
- // is a sign that there was no diff.
- allDiffs = append(allDiffs, layerDiff{
- label: "nil matches nil",
- })
- continue
- }
-
- if (*ls)[i] == nil {
- // Matching ls against other where the element in ls is nil. nil matches
- // everything so we just include a label without any rows. Having no rows
- // is a sign that there was no diff.
- allDiffs = append(allDiffs, layerDiff{
- label: "nil matches " + layerType(other[i]),
- })
- continue
- }
-
- if other[i] == nil {
- // Matching ls against other where the element in other is nil. nil
- // matches everything so we just include a label without any rows. Having
- // no rows is a sign that there was no diff.
- allDiffs = append(allDiffs, layerDiff{
- label: layerType((*ls)[i]) + " matches nil",
- })
- continue
- }
-
- if reflect.TypeOf((*ls)[i]) == reflect.TypeOf(other[i]) {
- // Matching ls against other where both elements have the same type. Match
- // each field pairwise and only report a diff if there is a mismatch,
- // which is only when both sides are non-nil and have differring values.
- diff := diffLayer((*ls)[i], other[i])
- var layerDiffRows []layerDiffRow
- for _, d := range diff {
- if d.got == "" || d.want == "" || d.got == d.want {
- continue
- }
- layerDiffRows = append(layerDiffRows, layerDiffRow{
- d.field,
- d.got,
- d.want,
- })
- }
- if len(layerDiffRows) > 0 {
- allDiffs = append(allDiffs, layerDiff{
- label: layerType((*ls)[i]),
- rows: layerDiffRows,
- })
- } else {
- allDiffs = append(allDiffs, layerDiff{
- label: layerType((*ls)[i]) + " matches " + layerType(other[i]),
- // Having no rows is a sign that there was no diff.
- })
- }
- continue
- }
- // Neither side is nil and the types are different, so we'll display one
- // side then the other.
- allDiffs = append(allDiffs, layerDiff{
- label: layerType((*ls)[i]) + " doesn't match " + layerType(other[i]),
- })
- diff := diffLayer((*ls)[i], (*ls)[i])
- layerDiffRows := []layerDiffRow{}
- for _, d := range diff {
- if len(d.got) == 0 {
- continue
- }
- layerDiffRows = append(layerDiffRows, layerDiffRow{
- d.field,
- d.got,
- "",
- })
- }
- allDiffs = append(allDiffs, layerDiff{
- label: layerType((*ls)[i]),
- rows: layerDiffRows,
- })
-
- layerDiffRows = []layerDiffRow{}
- diff = diffLayer(other[i], other[i])
- for _, d := range diff {
- if len(d.want) == 0 {
- continue
- }
- layerDiffRows = append(layerDiffRows, layerDiffRow{
- d.field,
- "",
- d.want,
- })
- }
- allDiffs = append(allDiffs, layerDiff{
- label: layerType(other[i]),
- rows: layerDiffRows,
- })
- }
-
- output := ""
- // These are for output formatting.
- maxLabelLen, maxFieldLen, maxGotLen, maxWantLen := 0, 0, 0, 0
- foundOne := false
- for _, l := range allDiffs {
- if len(l.label) > maxLabelLen && len(l.rows) > 0 {
- maxLabelLen = len(l.label)
- }
- if l.rows != nil {
- foundOne = true
- }
- for _, r := range l.rows {
- if len(r.field) > maxFieldLen {
- maxFieldLen = len(r.field)
- }
- if l := len(fmt.Sprint(r.got)); l > maxGotLen {
- maxGotLen = l
- }
- if l := len(fmt.Sprint(r.want)); l > maxWantLen {
- maxWantLen = l
- }
- }
- }
- if !foundOne {
- return ""
- }
- for _, l := range allDiffs {
- if len(l.rows) == 0 {
- output += "(" + l.label + ")\n"
- continue
- }
- for i, r := range l.rows {
- var label string
- if i == 0 {
- label = l.label + ":"
- }
- output += fmt.Sprintf(
- "%*s %*s %*v %*v\n",
- maxLabelLen+1, label,
- maxFieldLen+1, r.field+":",
- maxGotLen, r.got,
- maxWantLen, r.want,
- )
- }
- }
- return output
-}
-
-// merge merges the other Layers into ls. If the other Layers is longer, those
-// additional Layer structs are added to ls. The errors from merging are
-// collected and returned.
-func (ls *Layers) merge(other Layers) error {
- var errs error
- for i, o := range other {
- if i < len(*ls) {
- errs = multierr.Combine(errs, (*ls)[i].merge(o))
- } else {
- *ls = append(*ls, o)
- }
- }
- return errs
-}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-30 02:12:44 +0000