Beispiel #1
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func decodeSCTPEmptyLayer(data []byte, p gopacket.PacketBuilder) error {
	sc := &SCTPEmptyLayer{
		SCTPChunk: decodeSCTPChunk(data),
	}
	p.AddLayer(sc)
	return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
}
Beispiel #2
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func decodeSCTPCookieEcho(data []byte, p gopacket.PacketBuilder) error {
	sc := &SCTPCookieEcho{
		SCTPChunk: decodeSCTPChunk(data),
	}
	sc.Cookie = data[4:sc.Length]
	p.AddLayer(sc)
	return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
}
Beispiel #3
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func decodeSCTPShutdown(data []byte, p gopacket.PacketBuilder) error {
	sc := &SCTPShutdown{
		SCTPChunk:        decodeSCTPChunk(data),
		CumulativeTSNAck: binary.BigEndian.Uint32(data[4:8]),
	}
	p.AddLayer(sc)
	return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
}
Beispiel #4
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func decodeICMPv4(data []byte, p gopacket.PacketBuilder) error {
	i := &ICMPv4{}
	err := i.DecodeFromBytes(data, p)
	if err != nil {
		return err
	}
	p.AddLayer(i)
	return p.NextDecoder(gopacket.LayerTypePayload)
}
Beispiel #5
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func decodeIPv6HopByHop(data []byte, p gopacket.PacketBuilder) error {
	i := &IPv6HopByHop{}
	err := i.DecodeFromBytes(data, p)
	p.AddLayer(i)
	if err != nil {
		return err
	}
	return p.NextDecoder(i.NextHeader)
}
Beispiel #6
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func decodeDHCPv4(data []byte, p gopacket.PacketBuilder) error {
	dhcp := &DHCPv4{}
	err := dhcp.DecodeFromBytes(data, p)
	if err != nil {
		return err
	}
	p.AddLayer(dhcp)
	return p.NextDecoder(gopacket.LayerTypePayload)
}
Beispiel #7
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func decodeIPSecESP(data []byte, p gopacket.PacketBuilder) error {
	i := &IPSecESP{
		BaseLayer: BaseLayer{data, nil},
		SPI:       binary.BigEndian.Uint32(data[:4]),
		Seq:       binary.BigEndian.Uint32(data[4:8]),
		Encrypted: data[8:],
	}
	p.AddLayer(i)
	return nil
}
Beispiel #8
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// decodeDNS decodes the byte slice into a DNS type. It also
// setups the application Layer in PacketBuilder.
func decodeDNS(data []byte, p gopacket.PacketBuilder) error {
	d := &DNS{}
	err := d.DecodeFromBytes(data, p)
	if err != nil {
		return err
	}
	p.AddLayer(d)
	p.SetApplicationLayer(d)
	return nil
}
Beispiel #9
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func decodeEthernetCTP(data []byte, p gopacket.PacketBuilder) error {
	c := &EthernetCTP{
		SkipCount: binary.LittleEndian.Uint16(data[:2]),
		BaseLayer: BaseLayer{data[:2], data[2:]},
	}
	if c.SkipCount%2 != 0 {
		return fmt.Errorf("EthernetCTP skip count is odd: %d", c.SkipCount)
	}
	p.AddLayer(c)
	return p.NextDecoder(gopacket.DecodeFunc(decodeEthernetCTPFromFunctionType))
}
Beispiel #10
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func decodeSNAP(data []byte, p gopacket.PacketBuilder) error {
	s := &SNAP{
		OrganizationalCode: data[:3],
		Type:               EthernetType(binary.BigEndian.Uint16(data[3:5])),
		BaseLayer:          BaseLayer{data[:5], data[5:]},
	}
	p.AddLayer(s)
	// BUG(gconnell):  When decoding SNAP, we treat the SNAP type as an Ethernet
	// type.  This may not actually be an ethernet type in all cases,
	// depending on the organizational code.  Right now, we don't check.
	return p.NextDecoder(s.Type)
}
Beispiel #11
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func decodingLayerDecoder(d layerDecodingLayer, data []byte, p gopacket.PacketBuilder) error {
	err := d.DecodeFromBytes(data, p)
	if err != nil {
		return err
	}
	p.AddLayer(d)
	next := d.NextLayerType()
	if next == gopacket.LayerTypeZero {
		return nil
	}
	return p.NextDecoder(next)
}
Beispiel #12
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// decodePPPoE decodes the PPPoE header (see http://tools.ietf.org/html/rfc2516).
func decodePPPoE(data []byte, p gopacket.PacketBuilder) error {
	pppoe := &PPPoE{
		Version:   data[0] >> 4,
		Type:      data[0] & 0x0F,
		Code:      PPPoECode(data[1]),
		SessionId: binary.BigEndian.Uint16(data[2:4]),
		Length:    binary.BigEndian.Uint16(data[4:6]),
	}
	pppoe.BaseLayer = BaseLayer{data[:6], data[6 : 6+pppoe.Length]}
	p.AddLayer(pppoe)
	return p.NextDecoder(pppoe.Code)
}
Beispiel #13
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func decodeIPv6Fragment(data []byte, p gopacket.PacketBuilder) error {
	i := &IPv6Fragment{
		BaseLayer:      BaseLayer{data[:8], data[8:]},
		NextHeader:     IPProtocol(data[0]),
		Reserved1:      data[1],
		FragmentOffset: binary.BigEndian.Uint16(data[2:4]) >> 3,
		Reserved2:      data[3] & 0x6 >> 1,
		MoreFragments:  data[3]&0x1 != 0,
		Identification: binary.BigEndian.Uint32(data[4:8]),
	}
	p.AddLayer(i)
	return p.NextDecoder(gopacket.DecodeFragment)
}
Beispiel #14
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func decodeSCTPHeartbeat(data []byte, p gopacket.PacketBuilder) error {
	sc := &SCTPHeartbeat{
		SCTPChunk: decodeSCTPChunk(data),
	}
	paramData := data[4:sc.Length]
	for len(paramData) > 0 {
		p := SCTPHeartbeatParameter(decodeSCTPParameter(paramData))
		paramData = paramData[p.ActualLength:]
		sc.Parameters = append(sc.Parameters, p)
	}
	p.AddLayer(sc)
	return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
}
Beispiel #15
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func decodeNortelDiscovery(data []byte, p gopacket.PacketBuilder) error {
	c := &NortelDiscovery{}
	if len(data) < 11 {
		return fmt.Errorf("Invalid NortelDiscovery packet length %d", len(data))
	}
	c.IPAddress = data[0:4]
	c.SegmentID = data[4:7]
	c.Chassis = NDPChassisType(data[7])
	c.Backplane = NDPBackplaneType(data[8])
	c.State = NDPState(data[9])
	c.NumLinks = uint8(data[10])
	p.AddLayer(c)
	return nil
}
Beispiel #16
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func decodeIPv6Destination(data []byte, p gopacket.PacketBuilder) error {
	i := &IPv6Destination{
		ipv6ExtensionBase: decodeIPv6ExtensionBase(data),
		// We guess we'll 1-2 options, one regular option at least, then maybe one
		// padding option.
		Options: make([]IPv6DestinationOption, 0, 2),
	}
	var opt *IPv6DestinationOption
	for d := i.Contents[2:]; len(d) > 0; d = d[opt.ActualLength:] {
		i.Options = append(i.Options, IPv6DestinationOption(decodeIPv6HeaderTLVOption(d)))
		opt = &i.Options[len(i.Options)-1]
	}
	p.AddLayer(i)
	return p.NextDecoder(i.NextHeader)
}
Beispiel #17
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func decodeIPSecAH(data []byte, p gopacket.PacketBuilder) error {
	i := &IPSecAH{
		ipv6ExtensionBase: ipv6ExtensionBase{
			NextHeader:   IPProtocol(data[0]),
			HeaderLength: data[1],
		},
		Reserved: binary.BigEndian.Uint16(data[2:4]),
		SPI:      binary.BigEndian.Uint32(data[4:8]),
		Seq:      binary.BigEndian.Uint32(data[8:12]),
	}
	i.ActualLength = (int(i.HeaderLength) + 2) * 4
	i.AuthenticationData = data[12:i.ActualLength]
	i.Contents = data[:i.ActualLength]
	i.Payload = data[i.ActualLength:]
	p.AddLayer(i)
	return p.NextDecoder(i.NextHeader)
}
Beispiel #18
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func decodeSCTPInit(data []byte, p gopacket.PacketBuilder) error {
	sc := &SCTPInit{
		SCTPChunk:                      decodeSCTPChunk(data),
		InitiateTag:                    binary.BigEndian.Uint32(data[4:8]),
		AdvertisedReceiverWindowCredit: binary.BigEndian.Uint32(data[8:12]),
		OutboundStreams:                binary.BigEndian.Uint16(data[12:14]),
		InboundStreams:                 binary.BigEndian.Uint16(data[14:16]),
		InitialTSN:                     binary.BigEndian.Uint32(data[16:20]),
	}
	paramData := data[20:sc.ActualLength]
	for len(paramData) > 0 {
		p := SCTPInitParameter(decodeSCTPParameter(paramData))
		paramData = paramData[p.ActualLength:]
		sc.Parameters = append(sc.Parameters, p)
	}
	p.AddLayer(sc)
	return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
}
Beispiel #19
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func decodeIPv6(data []byte, p gopacket.PacketBuilder) error {
	ip6 := &IPv6{}
	err := ip6.DecodeFromBytes(data, p)
	p.AddLayer(ip6)
	p.SetNetworkLayer(ip6)
	if ip6.HopByHop != nil {
		// TODO(gconnell):  Since HopByHop is now an integral part of the IPv6
		// layer, should it actually be added as its own layer?  I'm leaning towards
		// no.
		p.AddLayer(ip6.HopByHop)
	}
	if err != nil {
		return err
	}
	if ip6.HopByHop != nil {
		return p.NextDecoder(ip6.HopByHop.NextHeader)
	}
	return p.NextDecoder(ip6.NextHeader)
}
Beispiel #20
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func decodeCiscoDiscovery(data []byte, p gopacket.PacketBuilder) error {
	c := &CiscoDiscovery{
		Version:  data[0],
		TTL:      data[1],
		Checksum: binary.BigEndian.Uint16(data[2:4]),
	}
	if c.Version != 1 && c.Version != 2 {
		return fmt.Errorf("Invalid CiscoDiscovery version number %d", c.Version)
	}
	var err error
	c.Values, err = decodeCiscoDiscoveryTLVs(data[4:])
	if err != nil {
		return err
	}
	c.Contents = data[0:4]
	c.Payload = data[4:]
	p.AddLayer(c)
	return p.NextDecoder(gopacket.DecodeFunc(decodeCiscoDiscoveryInfo))
}
Beispiel #21
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func decodeIPv6Routing(data []byte, p gopacket.PacketBuilder) error {
	i := &IPv6Routing{
		ipv6ExtensionBase: decodeIPv6ExtensionBase(data),
		RoutingType:       data[2],
		SegmentsLeft:      data[3],
		Reserved:          data[4:8],
	}
	switch i.RoutingType {
	case 0: // Source routing
		if (len(data)-8)%16 != 0 {
			return fmt.Errorf("Invalid IPv6 source routing, length of type 0 packet %d", len(data))
		}
		for d := i.Contents[8:]; len(d) >= 16; d = d[16:] {
			i.SourceRoutingIPs = append(i.SourceRoutingIPs, net.IP(d[:16]))
		}
	}
	p.AddLayer(i)
	return p.NextDecoder(i.NextHeader)
}
Beispiel #22
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func decodeLoopback(data []byte, p gopacket.PacketBuilder) error {
	// The protocol could be either big-endian or little-endian, we're
	// not sure.  But we're PRETTY sure that the value is less than
	// 256, so we can check the first two bytes.
	var prot uint32
	if data[0] == 0 && data[1] == 0 {
		prot = binary.BigEndian.Uint32(data[:4])
	} else {
		prot = binary.LittleEndian.Uint32(data[:4])
	}
	if prot > 0xFF {
		return fmt.Errorf("Invalid loopback protocol %q", data[:4])
	}
	l := &Loopback{
		BaseLayer: BaseLayer{data[:4], data[4:]},
		Family:    ProtocolFamily(prot),
	}
	p.AddLayer(l)
	return p.NextDecoder(l.Family)
}
Beispiel #23
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func decodeSCTPChunkTypeUnknown(data []byte, p gopacket.PacketBuilder) error {
	sc := &SCTPUnknownChunkType{SCTPChunk: decodeSCTPChunk(data)}
	sc.bytes = data[:sc.ActualLength]
	p.AddLayer(sc)
	p.SetErrorLayer(sc)
	return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
}
Beispiel #24
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func decodeLinuxSLL(data []byte, p gopacket.PacketBuilder) error {
	sll := &LinuxSLL{}
	if err := sll.DecodeFromBytes(data, p); err != nil {
		return err
	}
	p.AddLayer(sll)
	p.SetLinkLayer(sll)
	return p.NextDecoder(sll.EthernetType)
}
Beispiel #25
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func decodeSCTPSack(data []byte, p gopacket.PacketBuilder) error {
	sc := &SCTPSack{
		SCTPChunk:                      decodeSCTPChunk(data),
		CumulativeTSNAck:               binary.BigEndian.Uint32(data[4:8]),
		AdvertisedReceiverWindowCredit: binary.BigEndian.Uint32(data[8:12]),
		NumGapACKs:                     binary.BigEndian.Uint16(data[12:14]),
		NumDuplicateTSNs:               binary.BigEndian.Uint16(data[14:16]),
	}
	// We maximize gapAcks and dupTSNs here so we're not allocating tons
	// of memory based on a user-controlable field.  Our maximums are not exact,
	// but should give us sane defaults... we'll still hit slice boundaries and
	// fail if the user-supplied values are too high (in the for loops below), but
	// the amount of memory we'll have allocated because of that should be small
	// (< sc.ActualLength)
	gapAcks := sc.SCTPChunk.ActualLength / 2
	dupTSNs := (sc.SCTPChunk.ActualLength - gapAcks*2) / 4
	if gapAcks > int(sc.NumGapACKs) {
		gapAcks = int(sc.NumGapACKs)
	}
	if dupTSNs > int(sc.NumDuplicateTSNs) {
		dupTSNs = int(sc.NumDuplicateTSNs)
	}
	sc.GapACKs = make([]uint16, 0, gapAcks)
	sc.DuplicateTSNs = make([]uint32, 0, dupTSNs)
	bytesRemaining := data[16:]
	for i := 0; i < int(sc.NumGapACKs); i++ {
		sc.GapACKs = append(sc.GapACKs, binary.BigEndian.Uint16(bytesRemaining[:2]))
		bytesRemaining = bytesRemaining[2:]
	}
	for i := 0; i < int(sc.NumDuplicateTSNs); i++ {
		sc.DuplicateTSNs = append(sc.DuplicateTSNs, binary.BigEndian.Uint32(bytesRemaining[:4]))
		bytesRemaining = bytesRemaining[4:]
	}
	p.AddLayer(sc)
	return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
}
Beispiel #26
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func decodeEthernet(data []byte, p gopacket.PacketBuilder) error {
	eth := &Ethernet{}
	err := eth.DecodeFromBytes(data, p)
	if err != nil {
		return err
	}
	p.AddLayer(eth)
	p.SetLinkLayer(eth)
	return p.NextDecoder(eth.EthernetType)
}
Beispiel #27
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func decodeTCP(data []byte, p gopacket.PacketBuilder) error {
	tcp := &TCP{}
	err := tcp.DecodeFromBytes(data, p)
	p.AddLayer(tcp)
	p.SetTransportLayer(tcp)
	if err != nil {
		return err
	}
	return p.NextDecoder(gopacket.LayerTypePayload)
}
Beispiel #28
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func decodeIPv4(data []byte, p gopacket.PacketBuilder) error {
	ip := &IPv4{}
	err := ip.DecodeFromBytes(data, p)
	p.AddLayer(ip)
	p.SetNetworkLayer(ip)
	if err != nil {
		return err
	}
	return p.NextDecoder(ip.NextLayerType())
}
Beispiel #29
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func decodeUDP(data []byte, p gopacket.PacketBuilder) error {
	udp := &UDP{}
	err := udp.DecodeFromBytes(data, p)
	p.AddLayer(udp)
	p.SetTransportLayer(udp)
	if err != nil {
		return err
	}
	return p.NextDecoder(udp.NextLayerType())
}
Beispiel #30
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func decodeFDDI(data []byte, p gopacket.PacketBuilder) error {
	f := &FDDI{
		FrameControl: FDDIFrameControl(data[0] & 0xF8),
		Priority:     data[0] & 0x07,
		SrcMAC:       net.HardwareAddr(data[1:7]),
		DstMAC:       net.HardwareAddr(data[7:13]),
		BaseLayer:    BaseLayer{data[:13], data[13:]},
	}
	p.SetLinkLayer(f)
	p.AddLayer(f)
	return p.NextDecoder(f.FrameControl)
}