747 lines
22 KiB
Go
747 lines
22 KiB
Go
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// Copyright 2012 Google, Inc. All rights reserved.
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//
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// Use of this source code is governed by a BSD-style license
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// that can be found in the LICENSE file in the root of the source
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// tree.
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package layers
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import (
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"encoding/binary"
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"errors"
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"fmt"
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"hash/crc32"
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"github.com/google/gopacket"
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)
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// SCTP contains information on the top level of an SCTP packet.
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type SCTP struct {
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BaseLayer
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SrcPort, DstPort SCTPPort
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VerificationTag uint32
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Checksum uint32
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sPort, dPort []byte
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}
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// LayerType returns gopacket.LayerTypeSCTP
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func (s *SCTP) LayerType() gopacket.LayerType { return LayerTypeSCTP }
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func decodeSCTP(data []byte, p gopacket.PacketBuilder) error {
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sctp := &SCTP{}
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err := sctp.DecodeFromBytes(data, p)
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p.AddLayer(sctp)
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p.SetTransportLayer(sctp)
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if err != nil {
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return err
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}
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return p.NextDecoder(sctpChunkTypePrefixDecoder)
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}
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var sctpChunkTypePrefixDecoder = gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix)
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// TransportFlow returns a flow based on the source and destination SCTP port.
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func (s *SCTP) TransportFlow() gopacket.Flow {
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return gopacket.NewFlow(EndpointSCTPPort, s.sPort, s.dPort)
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}
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func decodeWithSCTPChunkTypePrefix(data []byte, p gopacket.PacketBuilder) error {
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chunkType := SCTPChunkType(data[0])
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return chunkType.Decode(data, p)
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}
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// SerializeTo is for gopacket.SerializableLayer.
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func (s SCTP) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
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bytes, err := b.PrependBytes(12)
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if err != nil {
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return err
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}
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binary.BigEndian.PutUint16(bytes[0:2], uint16(s.SrcPort))
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binary.BigEndian.PutUint16(bytes[2:4], uint16(s.DstPort))
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binary.BigEndian.PutUint32(bytes[4:8], s.VerificationTag)
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if opts.ComputeChecksums {
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// Note: MakeTable(Castagnoli) actually only creates the table once, then
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// passes back a singleton on every other call, so this shouldn't cause
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// excessive memory allocation.
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binary.LittleEndian.PutUint32(bytes[8:12], crc32.Checksum(b.Bytes(), crc32.MakeTable(crc32.Castagnoli)))
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}
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return nil
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}
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func (sctp *SCTP) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
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if len(data) < 12 {
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return errors.New("Invalid SCTP common header length")
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}
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sctp.SrcPort = SCTPPort(binary.BigEndian.Uint16(data[:2]))
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sctp.sPort = data[:2]
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sctp.DstPort = SCTPPort(binary.BigEndian.Uint16(data[2:4]))
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sctp.dPort = data[2:4]
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sctp.VerificationTag = binary.BigEndian.Uint32(data[4:8])
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sctp.Checksum = binary.BigEndian.Uint32(data[8:12])
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sctp.BaseLayer = BaseLayer{data[:12], data[12:]}
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return nil
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}
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func (t *SCTP) CanDecode() gopacket.LayerClass {
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return LayerTypeSCTP
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}
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func (t *SCTP) NextLayerType() gopacket.LayerType {
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return gopacket.LayerTypePayload
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}
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// SCTPChunk contains the common fields in all SCTP chunks.
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type SCTPChunk struct {
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BaseLayer
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Type SCTPChunkType
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Flags uint8
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Length uint16
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// ActualLength is the total length of an SCTP chunk, including padding.
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// SCTP chunks start and end on 4-byte boundaries. So if a chunk has a length
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// of 18, it means that it has data up to and including byte 18, then padding
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// up to the next 4-byte boundary, 20. In this case, Length would be 18, and
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// ActualLength would be 20.
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ActualLength int
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}
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func roundUpToNearest4(i int) int {
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if i%4 == 0 {
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return i
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}
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return i + 4 - (i % 4)
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}
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func decodeSCTPChunk(data []byte) (SCTPChunk, error) {
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length := binary.BigEndian.Uint16(data[2:4])
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if length < 4 {
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return SCTPChunk{}, errors.New("invalid SCTP chunk length")
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}
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actual := roundUpToNearest4(int(length))
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ct := SCTPChunkType(data[0])
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// For SCTP Data, use a separate layer for the payload
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delta := 0
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if ct == SCTPChunkTypeData {
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delta = int(actual) - int(length)
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actual = 16
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}
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return SCTPChunk{
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Type: ct,
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Flags: data[1],
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Length: length,
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ActualLength: actual,
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BaseLayer: BaseLayer{data[:actual], data[actual : len(data)-delta]},
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}, nil
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}
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// SCTPParameter is a TLV parameter inside a SCTPChunk.
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type SCTPParameter struct {
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Type uint16
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Length uint16
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ActualLength int
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Value []byte
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}
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func decodeSCTPParameter(data []byte) SCTPParameter {
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length := binary.BigEndian.Uint16(data[2:4])
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return SCTPParameter{
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Type: binary.BigEndian.Uint16(data[0:2]),
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Length: length,
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Value: data[4:length],
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ActualLength: roundUpToNearest4(int(length)),
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}
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}
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func (p SCTPParameter) Bytes() []byte {
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length := 4 + len(p.Value)
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data := make([]byte, roundUpToNearest4(length))
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binary.BigEndian.PutUint16(data[0:2], p.Type)
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binary.BigEndian.PutUint16(data[2:4], uint16(length))
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copy(data[4:], p.Value)
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return data
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}
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// SCTPUnknownChunkType is the layer type returned when we don't recognize the
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// chunk type. Since there's a length in a known location, we can skip over
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// it even if we don't know what it is, and continue parsing the rest of the
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// chunks. This chunk is stored as an ErrorLayer in the packet.
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type SCTPUnknownChunkType struct {
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SCTPChunk
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bytes []byte
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}
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func decodeSCTPChunkTypeUnknown(data []byte, p gopacket.PacketBuilder) error {
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chunk, err := decodeSCTPChunk(data)
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if err != nil {
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return err
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}
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sc := &SCTPUnknownChunkType{SCTPChunk: chunk}
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sc.bytes = data[:sc.ActualLength]
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p.AddLayer(sc)
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p.SetErrorLayer(sc)
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return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
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}
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// SerializeTo is for gopacket.SerializableLayer.
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func (s SCTPUnknownChunkType) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
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bytes, err := b.PrependBytes(s.ActualLength)
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if err != nil {
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return err
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}
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copy(bytes, s.bytes)
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return nil
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}
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// LayerType returns gopacket.LayerTypeSCTPUnknownChunkType.
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func (s *SCTPUnknownChunkType) LayerType() gopacket.LayerType { return LayerTypeSCTPUnknownChunkType }
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// Payload returns all bytes in this header, including the decoded Type, Length,
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// and Flags.
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func (s *SCTPUnknownChunkType) Payload() []byte { return s.bytes }
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// Error implements ErrorLayer.
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func (s *SCTPUnknownChunkType) Error() error {
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return fmt.Errorf("No decode method available for SCTP chunk type %s", s.Type)
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}
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// SCTPData is the SCTP Data chunk layer.
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type SCTPData struct {
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SCTPChunk
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Unordered, BeginFragment, EndFragment bool
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TSN uint32
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StreamId uint16
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StreamSequence uint16
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PayloadProtocol SCTPPayloadProtocol
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}
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// LayerType returns gopacket.LayerTypeSCTPData.
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func (s *SCTPData) LayerType() gopacket.LayerType { return LayerTypeSCTPData }
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// SCTPPayloadProtocol represents a payload protocol
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type SCTPPayloadProtocol uint32
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// SCTPPayloadProtocol constonts from http://www.iana.org/assignments/sctp-parameters/sctp-parameters.xhtml
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const (
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SCTPProtocolReserved SCTPPayloadProtocol = 0
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SCTPPayloadUIA = 1
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SCTPPayloadM2UA = 2
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SCTPPayloadM3UA = 3
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SCTPPayloadSUA = 4
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SCTPPayloadM2PA = 5
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SCTPPayloadV5UA = 6
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SCTPPayloadH248 = 7
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SCTPPayloadBICC = 8
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SCTPPayloadTALI = 9
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SCTPPayloadDUA = 10
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SCTPPayloadASAP = 11
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SCTPPayloadENRP = 12
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SCTPPayloadH323 = 13
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SCTPPayloadQIPC = 14
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SCTPPayloadSIMCO = 15
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SCTPPayloadDDPSegment = 16
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SCTPPayloadDDPStream = 17
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SCTPPayloadS1AP = 18
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)
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func (p SCTPPayloadProtocol) String() string {
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switch p {
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case SCTPProtocolReserved:
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return "Reserved"
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case SCTPPayloadUIA:
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return "UIA"
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case SCTPPayloadM2UA:
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return "M2UA"
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case SCTPPayloadM3UA:
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return "M3UA"
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case SCTPPayloadSUA:
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return "SUA"
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case SCTPPayloadM2PA:
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return "M2PA"
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case SCTPPayloadV5UA:
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return "V5UA"
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case SCTPPayloadH248:
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return "H.248"
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case SCTPPayloadBICC:
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return "BICC"
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case SCTPPayloadTALI:
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return "TALI"
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case SCTPPayloadDUA:
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return "DUA"
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case SCTPPayloadASAP:
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return "ASAP"
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case SCTPPayloadENRP:
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return "ENRP"
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case SCTPPayloadH323:
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return "H.323"
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case SCTPPayloadQIPC:
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return "QIPC"
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case SCTPPayloadSIMCO:
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return "SIMCO"
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case SCTPPayloadDDPSegment:
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return "DDPSegment"
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case SCTPPayloadDDPStream:
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return "DDPStream"
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case SCTPPayloadS1AP:
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return "S1AP"
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}
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return fmt.Sprintf("Unknown(%d)", p)
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}
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func decodeSCTPData(data []byte, p gopacket.PacketBuilder) error {
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chunk, err := decodeSCTPChunk(data)
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if err != nil {
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return err
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}
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sc := &SCTPData{
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SCTPChunk: chunk,
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Unordered: data[1]&0x4 != 0,
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BeginFragment: data[1]&0x2 != 0,
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EndFragment: data[1]&0x1 != 0,
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TSN: binary.BigEndian.Uint32(data[4:8]),
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StreamId: binary.BigEndian.Uint16(data[8:10]),
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StreamSequence: binary.BigEndian.Uint16(data[10:12]),
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PayloadProtocol: SCTPPayloadProtocol(binary.BigEndian.Uint32(data[12:16])),
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}
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// Length is the length in bytes of the data, INCLUDING the 16-byte header.
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p.AddLayer(sc)
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return p.NextDecoder(gopacket.LayerTypePayload)
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}
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// SerializeTo is for gopacket.SerializableLayer.
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func (sc SCTPData) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
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payload := b.Bytes()
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// Pad the payload to a 32 bit boundary
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if rem := len(payload) % 4; rem != 0 {
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b.AppendBytes(4 - rem)
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}
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length := 16
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bytes, err := b.PrependBytes(length)
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if err != nil {
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return err
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}
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bytes[0] = uint8(sc.Type)
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flags := uint8(0)
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if sc.Unordered {
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flags |= 0x4
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}
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if sc.BeginFragment {
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flags |= 0x2
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}
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if sc.EndFragment {
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flags |= 0x1
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}
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bytes[1] = flags
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binary.BigEndian.PutUint16(bytes[2:4], uint16(length+len(payload)))
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binary.BigEndian.PutUint32(bytes[4:8], sc.TSN)
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binary.BigEndian.PutUint16(bytes[8:10], sc.StreamId)
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binary.BigEndian.PutUint16(bytes[10:12], sc.StreamSequence)
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binary.BigEndian.PutUint32(bytes[12:16], uint32(sc.PayloadProtocol))
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return nil
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}
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// SCTPInitParameter is a parameter for an SCTP Init or InitAck packet.
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type SCTPInitParameter SCTPParameter
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// SCTPInit is used as the return value for both SCTPInit and SCTPInitAck
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// messages.
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type SCTPInit struct {
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SCTPChunk
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InitiateTag uint32
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AdvertisedReceiverWindowCredit uint32
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OutboundStreams, InboundStreams uint16
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InitialTSN uint32
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Parameters []SCTPInitParameter
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}
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// LayerType returns either gopacket.LayerTypeSCTPInit or gopacket.LayerTypeSCTPInitAck.
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func (sc *SCTPInit) LayerType() gopacket.LayerType {
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if sc.Type == SCTPChunkTypeInitAck {
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return LayerTypeSCTPInitAck
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|
}
|
||
|
|
// sc.Type == SCTPChunkTypeInit
|
||
|
|
return LayerTypeSCTPInit
|
||
|
|
}
|
||
|
|
|
||
|
|
func decodeSCTPInit(data []byte, p gopacket.PacketBuilder) error {
|
||
|
|
chunk, err := decodeSCTPChunk(data)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
sc := &SCTPInit{
|
||
|
|
SCTPChunk: chunk,
|
||
|
|
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))
|
||
|
|
}
|
||
|
|
|
||
|
|
// SerializeTo is for gopacket.SerializableLayer.
|
||
|
|
func (sc SCTPInit) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
|
||
|
|
var payload []byte
|
||
|
|
for _, param := range sc.Parameters {
|
||
|
|
payload = append(payload, SCTPParameter(param).Bytes()...)
|
||
|
|
}
|
||
|
|
length := 20 + len(payload)
|
||
|
|
bytes, err := b.PrependBytes(roundUpToNearest4(length))
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bytes[0] = uint8(sc.Type)
|
||
|
|
bytes[1] = sc.Flags
|
||
|
|
binary.BigEndian.PutUint16(bytes[2:4], uint16(length))
|
||
|
|
binary.BigEndian.PutUint32(bytes[4:8], sc.InitiateTag)
|
||
|
|
binary.BigEndian.PutUint32(bytes[8:12], sc.AdvertisedReceiverWindowCredit)
|
||
|
|
binary.BigEndian.PutUint16(bytes[12:14], sc.OutboundStreams)
|
||
|
|
binary.BigEndian.PutUint16(bytes[14:16], sc.InboundStreams)
|
||
|
|
binary.BigEndian.PutUint32(bytes[16:20], sc.InitialTSN)
|
||
|
|
copy(bytes[20:], payload)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// SCTPSack is the SCTP Selective ACK chunk layer.
|
||
|
|
type SCTPSack struct {
|
||
|
|
SCTPChunk
|
||
|
|
CumulativeTSNAck uint32
|
||
|
|
AdvertisedReceiverWindowCredit uint32
|
||
|
|
NumGapACKs, NumDuplicateTSNs uint16
|
||
|
|
GapACKs []uint16
|
||
|
|
DuplicateTSNs []uint32
|
||
|
|
}
|
||
|
|
|
||
|
|
// LayerType return LayerTypeSCTPSack
|
||
|
|
func (sc *SCTPSack) LayerType() gopacket.LayerType {
|
||
|
|
return LayerTypeSCTPSack
|
||
|
|
}
|
||
|
|
|
||
|
|
func decodeSCTPSack(data []byte, p gopacket.PacketBuilder) error {
|
||
|
|
chunk, err := decodeSCTPChunk(data)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
sc := &SCTPSack{
|
||
|
|
SCTPChunk: chunk,
|
||
|
|
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))
|
||
|
|
}
|
||
|
|
|
||
|
|
// SerializeTo is for gopacket.SerializableLayer.
|
||
|
|
func (sc SCTPSack) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
|
||
|
|
length := 16 + 2*len(sc.GapACKs) + 4*len(sc.DuplicateTSNs)
|
||
|
|
bytes, err := b.PrependBytes(roundUpToNearest4(length))
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bytes[0] = uint8(sc.Type)
|
||
|
|
bytes[1] = sc.Flags
|
||
|
|
binary.BigEndian.PutUint16(bytes[2:4], uint16(length))
|
||
|
|
binary.BigEndian.PutUint32(bytes[4:8], sc.CumulativeTSNAck)
|
||
|
|
binary.BigEndian.PutUint32(bytes[8:12], sc.AdvertisedReceiverWindowCredit)
|
||
|
|
binary.BigEndian.PutUint16(bytes[12:14], uint16(len(sc.GapACKs)))
|
||
|
|
binary.BigEndian.PutUint16(bytes[14:16], uint16(len(sc.DuplicateTSNs)))
|
||
|
|
for i, v := range sc.GapACKs {
|
||
|
|
binary.BigEndian.PutUint16(bytes[16+i*2:], v)
|
||
|
|
}
|
||
|
|
offset := 16 + 2*len(sc.GapACKs)
|
||
|
|
for i, v := range sc.DuplicateTSNs {
|
||
|
|
binary.BigEndian.PutUint32(bytes[offset+i*4:], v)
|
||
|
|
}
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// SCTPHeartbeatParameter is the parameter type used by SCTP heartbeat and
|
||
|
|
// heartbeat ack layers.
|
||
|
|
type SCTPHeartbeatParameter SCTPParameter
|
||
|
|
|
||
|
|
// SCTPHeartbeat is the SCTP heartbeat layer, also used for heatbeat ack.
|
||
|
|
type SCTPHeartbeat struct {
|
||
|
|
SCTPChunk
|
||
|
|
Parameters []SCTPHeartbeatParameter
|
||
|
|
}
|
||
|
|
|
||
|
|
// LayerType returns gopacket.LayerTypeSCTPHeartbeat.
|
||
|
|
func (sc *SCTPHeartbeat) LayerType() gopacket.LayerType {
|
||
|
|
if sc.Type == SCTPChunkTypeHeartbeatAck {
|
||
|
|
return LayerTypeSCTPHeartbeatAck
|
||
|
|
}
|
||
|
|
// sc.Type == SCTPChunkTypeHeartbeat
|
||
|
|
return LayerTypeSCTPHeartbeat
|
||
|
|
}
|
||
|
|
|
||
|
|
func decodeSCTPHeartbeat(data []byte, p gopacket.PacketBuilder) error {
|
||
|
|
chunk, err := decodeSCTPChunk(data)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
sc := &SCTPHeartbeat{
|
||
|
|
SCTPChunk: chunk,
|
||
|
|
}
|
||
|
|
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))
|
||
|
|
}
|
||
|
|
|
||
|
|
// SerializeTo is for gopacket.SerializableLayer.
|
||
|
|
func (sc SCTPHeartbeat) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
|
||
|
|
var payload []byte
|
||
|
|
for _, param := range sc.Parameters {
|
||
|
|
payload = append(payload, SCTPParameter(param).Bytes()...)
|
||
|
|
}
|
||
|
|
length := 4 + len(payload)
|
||
|
|
|
||
|
|
bytes, err := b.PrependBytes(roundUpToNearest4(length))
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bytes[0] = uint8(sc.Type)
|
||
|
|
bytes[1] = sc.Flags
|
||
|
|
binary.BigEndian.PutUint16(bytes[2:4], uint16(length))
|
||
|
|
copy(bytes[4:], payload)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// SCTPErrorParameter is the parameter type used by SCTP Abort and Error layers.
|
||
|
|
type SCTPErrorParameter SCTPParameter
|
||
|
|
|
||
|
|
// SCTPError is the SCTP error layer, also used for SCTP aborts.
|
||
|
|
type SCTPError struct {
|
||
|
|
SCTPChunk
|
||
|
|
Parameters []SCTPErrorParameter
|
||
|
|
}
|
||
|
|
|
||
|
|
// LayerType returns LayerTypeSCTPAbort or LayerTypeSCTPError.
|
||
|
|
func (sc *SCTPError) LayerType() gopacket.LayerType {
|
||
|
|
if sc.Type == SCTPChunkTypeAbort {
|
||
|
|
return LayerTypeSCTPAbort
|
||
|
|
}
|
||
|
|
// sc.Type == SCTPChunkTypeError
|
||
|
|
return LayerTypeSCTPError
|
||
|
|
}
|
||
|
|
|
||
|
|
func decodeSCTPError(data []byte, p gopacket.PacketBuilder) error {
|
||
|
|
// remarkably similar to decodeSCTPHeartbeat ;)
|
||
|
|
chunk, err := decodeSCTPChunk(data)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
sc := &SCTPError{
|
||
|
|
SCTPChunk: chunk,
|
||
|
|
}
|
||
|
|
paramData := data[4:sc.Length]
|
||
|
|
for len(paramData) > 0 {
|
||
|
|
p := SCTPErrorParameter(decodeSCTPParameter(paramData))
|
||
|
|
paramData = paramData[p.ActualLength:]
|
||
|
|
sc.Parameters = append(sc.Parameters, p)
|
||
|
|
}
|
||
|
|
p.AddLayer(sc)
|
||
|
|
return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
|
||
|
|
}
|
||
|
|
|
||
|
|
// SerializeTo is for gopacket.SerializableLayer.
|
||
|
|
func (sc SCTPError) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
|
||
|
|
var payload []byte
|
||
|
|
for _, param := range sc.Parameters {
|
||
|
|
payload = append(payload, SCTPParameter(param).Bytes()...)
|
||
|
|
}
|
||
|
|
length := 4 + len(payload)
|
||
|
|
|
||
|
|
bytes, err := b.PrependBytes(roundUpToNearest4(length))
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bytes[0] = uint8(sc.Type)
|
||
|
|
bytes[1] = sc.Flags
|
||
|
|
binary.BigEndian.PutUint16(bytes[2:4], uint16(length))
|
||
|
|
copy(bytes[4:], payload)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// SCTPShutdown is the SCTP shutdown layer.
|
||
|
|
type SCTPShutdown struct {
|
||
|
|
SCTPChunk
|
||
|
|
CumulativeTSNAck uint32
|
||
|
|
}
|
||
|
|
|
||
|
|
// LayerType returns gopacket.LayerTypeSCTPShutdown.
|
||
|
|
func (sc *SCTPShutdown) LayerType() gopacket.LayerType { return LayerTypeSCTPShutdown }
|
||
|
|
|
||
|
|
func decodeSCTPShutdown(data []byte, p gopacket.PacketBuilder) error {
|
||
|
|
chunk, err := decodeSCTPChunk(data)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
sc := &SCTPShutdown{
|
||
|
|
SCTPChunk: chunk,
|
||
|
|
CumulativeTSNAck: binary.BigEndian.Uint32(data[4:8]),
|
||
|
|
}
|
||
|
|
p.AddLayer(sc)
|
||
|
|
return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
|
||
|
|
}
|
||
|
|
|
||
|
|
// SerializeTo is for gopacket.SerializableLayer.
|
||
|
|
func (sc SCTPShutdown) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
|
||
|
|
bytes, err := b.PrependBytes(8)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bytes[0] = uint8(sc.Type)
|
||
|
|
bytes[1] = sc.Flags
|
||
|
|
binary.BigEndian.PutUint16(bytes[2:4], 8)
|
||
|
|
binary.BigEndian.PutUint32(bytes[4:8], sc.CumulativeTSNAck)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// SCTPShutdownAck is the SCTP shutdown layer.
|
||
|
|
type SCTPShutdownAck struct {
|
||
|
|
SCTPChunk
|
||
|
|
}
|
||
|
|
|
||
|
|
// LayerType returns gopacket.LayerTypeSCTPShutdownAck.
|
||
|
|
func (sc *SCTPShutdownAck) LayerType() gopacket.LayerType { return LayerTypeSCTPShutdownAck }
|
||
|
|
|
||
|
|
func decodeSCTPShutdownAck(data []byte, p gopacket.PacketBuilder) error {
|
||
|
|
chunk, err := decodeSCTPChunk(data)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
sc := &SCTPShutdownAck{
|
||
|
|
SCTPChunk: chunk,
|
||
|
|
}
|
||
|
|
p.AddLayer(sc)
|
||
|
|
return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
|
||
|
|
}
|
||
|
|
|
||
|
|
// SerializeTo is for gopacket.SerializableLayer.
|
||
|
|
func (sc SCTPShutdownAck) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
|
||
|
|
bytes, err := b.PrependBytes(4)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bytes[0] = uint8(sc.Type)
|
||
|
|
bytes[1] = sc.Flags
|
||
|
|
binary.BigEndian.PutUint16(bytes[2:4], 4)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// SCTPCookieEcho is the SCTP Cookie Echo layer.
|
||
|
|
type SCTPCookieEcho struct {
|
||
|
|
SCTPChunk
|
||
|
|
Cookie []byte
|
||
|
|
}
|
||
|
|
|
||
|
|
// LayerType returns gopacket.LayerTypeSCTPCookieEcho.
|
||
|
|
func (sc *SCTPCookieEcho) LayerType() gopacket.LayerType { return LayerTypeSCTPCookieEcho }
|
||
|
|
|
||
|
|
func decodeSCTPCookieEcho(data []byte, p gopacket.PacketBuilder) error {
|
||
|
|
chunk, err := decodeSCTPChunk(data)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
sc := &SCTPCookieEcho{
|
||
|
|
SCTPChunk: chunk,
|
||
|
|
}
|
||
|
|
sc.Cookie = data[4:sc.Length]
|
||
|
|
p.AddLayer(sc)
|
||
|
|
return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
|
||
|
|
}
|
||
|
|
|
||
|
|
// SerializeTo is for gopacket.SerializableLayer.
|
||
|
|
func (sc SCTPCookieEcho) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
|
||
|
|
length := 4 + len(sc.Cookie)
|
||
|
|
bytes, err := b.PrependBytes(roundUpToNearest4(length))
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bytes[0] = uint8(sc.Type)
|
||
|
|
bytes[1] = sc.Flags
|
||
|
|
binary.BigEndian.PutUint16(bytes[2:4], uint16(length))
|
||
|
|
copy(bytes[4:], sc.Cookie)
|
||
|
|
return nil
|
||
|
|
}
|
||
|
|
|
||
|
|
// This struct is used by all empty SCTP chunks (currently CookieAck and
|
||
|
|
// ShutdownComplete).
|
||
|
|
type SCTPEmptyLayer struct {
|
||
|
|
SCTPChunk
|
||
|
|
}
|
||
|
|
|
||
|
|
// LayerType returns either gopacket.LayerTypeSCTPShutdownComplete or
|
||
|
|
// LayerTypeSCTPCookieAck.
|
||
|
|
func (sc *SCTPEmptyLayer) LayerType() gopacket.LayerType {
|
||
|
|
if sc.Type == SCTPChunkTypeShutdownComplete {
|
||
|
|
return LayerTypeSCTPShutdownComplete
|
||
|
|
}
|
||
|
|
// sc.Type == SCTPChunkTypeCookieAck
|
||
|
|
return LayerTypeSCTPCookieAck
|
||
|
|
}
|
||
|
|
|
||
|
|
func decodeSCTPEmptyLayer(data []byte, p gopacket.PacketBuilder) error {
|
||
|
|
chunk, err := decodeSCTPChunk(data)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
sc := &SCTPEmptyLayer{
|
||
|
|
SCTPChunk: chunk,
|
||
|
|
}
|
||
|
|
p.AddLayer(sc)
|
||
|
|
return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix))
|
||
|
|
}
|
||
|
|
|
||
|
|
// SerializeTo is for gopacket.SerializableLayer.
|
||
|
|
func (sc SCTPEmptyLayer) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
|
||
|
|
bytes, err := b.PrependBytes(4)
|
||
|
|
if err != nil {
|
||
|
|
return err
|
||
|
|
}
|
||
|
|
bytes[0] = uint8(sc.Type)
|
||
|
|
bytes[1] = sc.Flags
|
||
|
|
binary.BigEndian.PutUint16(bytes[2:4], 4)
|
||
|
|
return nil
|
||
|
|
}
|