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Diffstat (limited to 'test/packetimpact/testbench/layers.go')
-rw-r--r-- | test/packetimpact/testbench/layers.go | 671 |
1 files changed, 0 insertions, 671 deletions
diff --git a/test/packetimpact/testbench/layers.go b/test/packetimpact/testbench/layers.go deleted file mode 100644 index b467c15cc..000000000 --- a/test/packetimpact/testbench/layers.go +++ /dev/null @@ -1,671 +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 ( - "fmt" - "reflect" - "strings" - - "github.com/google/go-cmp/cmp" - "github.com/google/go-cmp/cmp/cmpopts" - "github.com/imdario/mergo" - "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) -} - -// LayerBase is the common elements of all layers. -type LayerBase struct { - nextLayer Layer - prevLayer Layer -} - -func (lb *LayerBase) next() Layer { - return lb.nextLayer -} - -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 { - // 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{})) -} - -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 - } - ret = append(ret, fmt.Sprintf("%s:%v", t.Name, reflect.Indirect(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) -} - -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 - default: - // TODO(b/150301488): Support more protocols, like IPv6. - 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 - default: - // Assume that the rest is a payload. - nextParser = ParsePayload - } - return ðer, nextParser -} - -func (l *Ether) match(other Layer) bool { - return equalLayer(l, other) -} - -func (l *Ether) length() int { - return header.EthernetMinimumSize -} - -// 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) -} - -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) - 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 - 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) -} - -// 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) -} - -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 -} - -// 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) - } - var payloadBytes buffer.VectorisedView - for current := l.next(); current != nil; current = current.next() { - payload, err := current.toBytes() - if err != nil { - return 0, fmt.Errorf("can't get bytes for next header: %s", payload) - } - payloadBytes.AppendView(payload) - } - 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 overrides the values in l with the values from other but only in fields -// where the value is not nil. -func (l *TCP) merge(other TCP) error { - return mergo.Merge(l, other, mergo.WithOverride) -} - -// 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) -} - -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 { - if l.Length == nil { - return header.UDPMinimumSize - } - return int(*l.Length) -} - -// merge overrides the values in l with the values from other but only in fields -// where the value is not nil. -func (l *UDP) merge(other UDP) error { - return mergo.Merge(l, other, mergo.WithOverride) -} - -// 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 -} - -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) -} - -// 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) - } - } -} - -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 := 0; i < len(*ls); i++ { - if !equalLayer((*ls)[i], other[i]) { - return false - } - } - return true -} |