diff options
| -rw-r--r-- | test/packetimpact/testbench/layers.go | 164 | ||||
| -rw-r--r-- | test/packetimpact/testbench/layers_test.go | 111 |
2 files changed, 261 insertions, 14 deletions
diff --git a/test/packetimpact/testbench/layers.go b/test/packetimpact/testbench/layers.go index 560c4111b..a8121b0da 100644 --- a/test/packetimpact/testbench/layers.go +++ b/test/packetimpact/testbench/layers.go @@ -477,6 +477,10 @@ func (l *IPv6) ToBytes() ([]byte, error) { fields.NextHeader = uint8(header.UDPProtocolNumber) case *ICMPv6: fields.NextHeader = uint8(header.ICMPv6ProtocolNumber) + case *IPv6HopByHopOptionsExtHdr: + fields.NextHeader = uint8(header.IPv6HopByHopOptionsExtHdrIdentifier) + case *IPv6DestinationOptionsExtHdr: + fields.NextHeader = uint8(header.IPv6DestinationOptionsExtHdrIdentifier) 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) @@ -495,6 +499,25 @@ func (l *IPv6) ToBytes() ([]byte, error) { return h, nil } +// nextIPv6PayloadParser finds the corresponding parser for nextHeader. +func nextIPv6PayloadParser(nextHeader uint8) layerParser { + switch tcpip.TransportProtocolNumber(nextHeader) { + case header.TCPProtocolNumber: + return parseTCP + case header.UDPProtocolNumber: + return parseUDP + case header.ICMPv6ProtocolNumber: + return parseICMPv6 + } + switch header.IPv6ExtensionHeaderIdentifier(nextHeader) { + case header.IPv6HopByHopOptionsExtHdrIdentifier: + return parseIPv6HopByHopOptionsExtHdr + case header.IPv6DestinationOptionsExtHdrIdentifier: + return parseIPv6DestinationOptionsExtHdr + } + return parsePayload +} + // parseIPv6 parses the bytes assuming that they start with an ipv6 header and // continues parsing further encapsulations. func parseIPv6(b []byte) (Layer, layerParser) { @@ -509,18 +532,7 @@ func parseIPv6(b []byte) (Layer, layerParser) { 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 - } + nextParser := nextIPv6PayloadParser(h.NextHeader()) return &ipv6, nextParser } @@ -538,6 +550,123 @@ func (l *IPv6) merge(other Layer) error { return mergeLayer(l, other) } +// IPv6HopByHopOptionsExtHdr can construct and match an IPv6HopByHopOptions +// Extension Header. +type IPv6HopByHopOptionsExtHdr struct { + LayerBase + NextHeader *header.IPv6ExtensionHeaderIdentifier + Options []byte +} + +// IPv6DestinationOptionsExtHdr can construct and match an IPv6DestinationOptions +// Extension Header. +type IPv6DestinationOptionsExtHdr struct { + LayerBase + NextHeader *header.IPv6ExtensionHeaderIdentifier + Options []byte +} + +// ipv6OptionsExtHdrToBytes serializes an options extension header into bytes. +func ipv6OptionsExtHdrToBytes(nextHeader *header.IPv6ExtensionHeaderIdentifier, options []byte) []byte { + length := len(options) + 2 + bytes := make([]byte, length) + if nextHeader == nil { + bytes[0] = byte(header.IPv6NoNextHeaderIdentifier) + } else { + bytes[0] = byte(*nextHeader) + } + // ExtHdrLen field is the length of the extension header + // in 8-octet unit, ignoring the first 8 octets. + // https://tools.ietf.org/html/rfc2460#section-4.3 + // https://tools.ietf.org/html/rfc2460#section-4.6 + bytes[1] = uint8((length - 8) / 8) + copy(bytes[2:], options) + return bytes +} + +// IPv6ExtHdrIdent is a helper routine that allocates a new +// header.IPv6ExtensionHeaderIdentifier value to store v and returns a pointer +// to it. +func IPv6ExtHdrIdent(id header.IPv6ExtensionHeaderIdentifier) *header.IPv6ExtensionHeaderIdentifier { + return &id +} + +// ToBytes implements Layer.ToBytes +func (l *IPv6HopByHopOptionsExtHdr) ToBytes() ([]byte, error) { + return ipv6OptionsExtHdrToBytes(l.NextHeader, l.Options), nil +} + +// ToBytes implements Layer.ToBytes +func (l *IPv6DestinationOptionsExtHdr) ToBytes() ([]byte, error) { + return ipv6OptionsExtHdrToBytes(l.NextHeader, l.Options), nil +} + +// parseIPv6ExtHdr parses an IPv6 extension header and returns the NextHeader +// field, the rest of the payload and a parser function for the corresponding +// next extension header. +func parseIPv6ExtHdr(b []byte) (header.IPv6ExtensionHeaderIdentifier, []byte, layerParser) { + nextHeader := b[0] + // For HopByHop and Destination options extension headers, + // This field is the length of the extension header in + // 8-octet units, not including the first 8 octets. + // https://tools.ietf.org/html/rfc2460#section-4.3 + // https://tools.ietf.org/html/rfc2460#section-4.6 + length := b[1]*8 + 8 + data := b[2:length] + nextParser := nextIPv6PayloadParser(nextHeader) + return header.IPv6ExtensionHeaderIdentifier(nextHeader), data, nextParser +} + +// parseIPv6HopByHopOptionsExtHdr parses the bytes assuming that they start +// with an IPv6 HopByHop Options Extension Header. +func parseIPv6HopByHopOptionsExtHdr(b []byte) (Layer, layerParser) { + nextHeader, options, nextParser := parseIPv6ExtHdr(b) + return &IPv6HopByHopOptionsExtHdr{NextHeader: &nextHeader, Options: options}, nextParser +} + +// parseIPv6DestinationOptionsExtHdr parses the bytes assuming that they start +// with an IPv6 Destination Options Extension Header. +func parseIPv6DestinationOptionsExtHdr(b []byte) (Layer, layerParser) { + nextHeader, options, nextParser := parseIPv6ExtHdr(b) + return &IPv6DestinationOptionsExtHdr{NextHeader: &nextHeader, Options: options}, nextParser +} + +func (l *IPv6HopByHopOptionsExtHdr) length() int { + return len(l.Options) + 2 +} + +func (l *IPv6HopByHopOptionsExtHdr) match(other Layer) bool { + return equalLayer(l, other) +} + +// merge overrides the values in l with the values from other but only in fields +// where the value is not nil. +func (l *IPv6HopByHopOptionsExtHdr) merge(other Layer) error { + return mergeLayer(l, other) +} + +func (l *IPv6HopByHopOptionsExtHdr) String() string { + return stringLayer(l) +} + +func (l *IPv6DestinationOptionsExtHdr) length() int { + return len(l.Options) + 2 +} + +func (l *IPv6DestinationOptionsExtHdr) match(other Layer) bool { + return equalLayer(l, other) +} + +// merge overrides the values in l with the values from other but only in fields +// where the value is not nil. +func (l *IPv6DestinationOptionsExtHdr) merge(other Layer) error { + return mergeLayer(l, other) +} + +func (l *IPv6DestinationOptionsExtHdr) String() string { + return stringLayer(l) +} + // ICMPv6 can construct and match an ICMPv6 encapsulation. type ICMPv6 struct { LayerBase @@ -567,8 +696,15 @@ func (l *ICMPv6) ToBytes() ([]byte, error) { if l.Checksum != nil { h.SetChecksum(*l.Checksum) } else { - ipv6 := l.Prev().(*IPv6) - h.SetChecksum(header.ICMPv6Checksum(h, *ipv6.SrcAddr, *ipv6.DstAddr, buffer.VectorisedView{})) + // It is possible that the ICMPv6 header does not follow the IPv6 header + // immediately, there could be one or more extension headers in between. + // We need to search forward to find the IPv6 header. + for prev := l.Prev(); prev != nil; prev = prev.Prev() { + if ipv6, ok := prev.(*IPv6); ok { + h.SetChecksum(header.ICMPv6Checksum(h, *ipv6.SrcAddr, *ipv6.DstAddr, buffer.VectorisedView{})) + break + } + } } return h, nil } diff --git a/test/packetimpact/testbench/layers_test.go b/test/packetimpact/testbench/layers_test.go index c7f00e70d..382a983a1 100644 --- a/test/packetimpact/testbench/layers_test.go +++ b/test/packetimpact/testbench/layers_test.go @@ -505,3 +505,114 @@ func TestTCPOptions(t *testing.T) { }) } } + +func TestIPv6ExtHdrOptions(t *testing.T) { + for _, tt := range []struct { + description string + wantBytes []byte + wantLayers Layers + }{ + { + description: "IPv6/HopByHop", + wantBytes: []byte{ + // IPv6 Header + 0x60, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x40, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x01, 0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xde, 0xad, 0xbe, 0xef, + // HopByHop Options + 0x3b, 0x00, 0x05, 0x02, 0x00, 0x00, 0x01, 0x00, + }, + wantLayers: []Layer{ + &IPv6{ + SrcAddr: Address(tcpip.Address(net.ParseIP("::1"))), + DstAddr: Address(tcpip.Address(net.ParseIP("fe80::dead:beef"))), + }, + &IPv6HopByHopOptionsExtHdr{ + NextHeader: IPv6ExtHdrIdent(header.IPv6NoNextHeaderIdentifier), + Options: []byte{0x05, 0x02, 0x00, 0x00, 0x01, 0x00}, + }, + &Payload{ + Bytes: nil, + }, + }, + }, + { + description: "IPv6/HopByHop/Payload", + wantBytes: []byte{ + // IPv6 Header + 0x60, 0x00, 0x00, 0x00, 0x00, 0x13, 0x00, 0x40, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x01, 0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xde, 0xad, 0xbe, 0xef, + // HopByHop Options + 0x3b, 0x00, 0x05, 0x02, 0x00, 0x00, 0x01, 0x00, + // Sample Data + 0x53, 0x61, 0x6d, 0x70, 0x6c, 0x65, 0x20, 0x44, 0x61, 0x74, 0x61, + }, + wantLayers: []Layer{ + &IPv6{ + SrcAddr: Address(tcpip.Address(net.ParseIP("::1"))), + DstAddr: Address(tcpip.Address(net.ParseIP("fe80::dead:beef"))), + }, + &IPv6HopByHopOptionsExtHdr{ + NextHeader: IPv6ExtHdrIdent(header.IPv6NoNextHeaderIdentifier), + Options: []byte{0x05, 0x02, 0x00, 0x00, 0x01, 0x00}, + }, + &Payload{ + Bytes: []byte("Sample Data"), + }, + }, + }, + { + description: "IPv6/HopByHop/Destination/ICMPv6", + wantBytes: []byte{ + // IPv6 Header + 0x60, 0x00, 0x00, 0x00, 0x00, 0x18, 0x00, 0x40, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x01, 0xfe, 0x80, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xde, 0xad, 0xbe, 0xef, + // HopByHop Options + 0x3c, 0x00, 0x05, 0x02, 0x00, 0x00, 0x01, 0x00, + // Destination Options + 0x3a, 0x00, 0x05, 0x02, 0x00, 0x00, 0x01, 0x00, + // ICMPv6 Param Problem + 0x04, 0x00, 0x5f, 0x98, 0x00, 0x00, 0x00, 0x06, + }, + wantLayers: []Layer{ + &IPv6{ + SrcAddr: Address(tcpip.Address(net.ParseIP("::1"))), + DstAddr: Address(tcpip.Address(net.ParseIP("fe80::dead:beef"))), + }, + &IPv6HopByHopOptionsExtHdr{ + NextHeader: IPv6ExtHdrIdent(header.IPv6DestinationOptionsExtHdrIdentifier), + Options: []byte{0x05, 0x02, 0x00, 0x00, 0x01, 0x00}, + }, + &IPv6DestinationOptionsExtHdr{ + NextHeader: IPv6ExtHdrIdent(header.IPv6ExtensionHeaderIdentifier(header.ICMPv6ProtocolNumber)), + Options: []byte{0x05, 0x02, 0x00, 0x00, 0x01, 0x00}, + }, + &ICMPv6{ + Type: ICMPv6Type(header.ICMPv6ParamProblem), + Code: Byte(0), + Checksum: Uint16(0x5f98), + NDPPayload: []byte{0x00, 0x00, 0x00, 0x06}, + }, + }, + }, + } { + t.Run(tt.description, func(t *testing.T) { + layers := parse(parseIPv6, tt.wantBytes) + if !layers.match(tt.wantLayers) { + t.Fatalf("match failed with diff: %s", layers.diff(tt.wantLayers)) + } + gotBytes, err := layers.ToBytes() + if err != nil { + t.Fatalf("ToBytes() failed on %s: %s", &layers, err) + } + if !bytes.Equal(tt.wantBytes, gotBytes) { + t.Fatalf("mismatching bytes, gotBytes: %x, wantBytes: %x", gotBytes, tt.wantBytes) + } + }) + } +} |