From 3f1edad4e6ba0a7876750aea55507fae14d8badf Mon Sep 17 00:00:00 2001 From: Milan Lenco Date: Wed, 11 Oct 2017 16:40:58 +0200 Subject: ODPM 266: Go-libmemif + 2 examples. Change-Id: Icdb9b9eb2314eff6c96afe7996fcf2728291de4a Signed-off-by: Milan Lenco --- vendor/github.com/google/gopacket/layers/sctp.go | 746 +++++++++++++++++++++++ 1 file changed, 746 insertions(+) create mode 100644 vendor/github.com/google/gopacket/layers/sctp.go (limited to 'vendor/github.com/google/gopacket/layers/sctp.go') diff --git a/vendor/github.com/google/gopacket/layers/sctp.go b/vendor/github.com/google/gopacket/layers/sctp.go new file mode 100644 index 0000000..511176e --- /dev/null +++ b/vendor/github.com/google/gopacket/layers/sctp.go @@ -0,0 +1,746 @@ +// Copyright 2012 Google, Inc. All rights reserved. +// +// Use of this source code is governed by a BSD-style license +// that can be found in the LICENSE file in the root of the source +// tree. + +package layers + +import ( + "encoding/binary" + "errors" + "fmt" + "hash/crc32" + + "github.com/google/gopacket" +) + +// SCTP contains information on the top level of an SCTP packet. +type SCTP struct { + BaseLayer + SrcPort, DstPort SCTPPort + VerificationTag uint32 + Checksum uint32 + sPort, dPort []byte +} + +// LayerType returns gopacket.LayerTypeSCTP +func (s *SCTP) LayerType() gopacket.LayerType { return LayerTypeSCTP } + +func decodeSCTP(data []byte, p gopacket.PacketBuilder) error { + sctp := &SCTP{} + err := sctp.DecodeFromBytes(data, p) + p.AddLayer(sctp) + p.SetTransportLayer(sctp) + if err != nil { + return err + } + return p.NextDecoder(sctpChunkTypePrefixDecoder) +} + +var sctpChunkTypePrefixDecoder = gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix) + +// TransportFlow returns a flow based on the source and destination SCTP port. +func (s *SCTP) TransportFlow() gopacket.Flow { + return gopacket.NewFlow(EndpointSCTPPort, s.sPort, s.dPort) +} + +func decodeWithSCTPChunkTypePrefix(data []byte, p gopacket.PacketBuilder) error { + chunkType := SCTPChunkType(data[0]) + return chunkType.Decode(data, p) +} + +// SerializeTo is for gopacket.SerializableLayer. +func (s SCTP) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error { + bytes, err := b.PrependBytes(12) + if err != nil { + return err + } + binary.BigEndian.PutUint16(bytes[0:2], uint16(s.SrcPort)) + binary.BigEndian.PutUint16(bytes[2:4], uint16(s.DstPort)) + binary.BigEndian.PutUint32(bytes[4:8], s.VerificationTag) + if opts.ComputeChecksums { + // Note: MakeTable(Castagnoli) actually only creates the table once, then + // passes back a singleton on every other call, so this shouldn't cause + // excessive memory allocation. + binary.LittleEndian.PutUint32(bytes[8:12], crc32.Checksum(b.Bytes(), crc32.MakeTable(crc32.Castagnoli))) + } + return nil +} + +func (sctp *SCTP) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error { + if len(data) < 12 { + return errors.New("Invalid SCTP common header length") + } + sctp.SrcPort = SCTPPort(binary.BigEndian.Uint16(data[:2])) + sctp.sPort = data[:2] + sctp.DstPort = SCTPPort(binary.BigEndian.Uint16(data[2:4])) + sctp.dPort = data[2:4] + sctp.VerificationTag = binary.BigEndian.Uint32(data[4:8]) + sctp.Checksum = binary.BigEndian.Uint32(data[8:12]) + sctp.BaseLayer = BaseLayer{data[:12], data[12:]} + + return nil +} + +func (t *SCTP) CanDecode() gopacket.LayerClass { + return LayerTypeSCTP +} + +func (t *SCTP) NextLayerType() gopacket.LayerType { + return gopacket.LayerTypePayload +} + +// SCTPChunk contains the common fields in all SCTP chunks. +type SCTPChunk struct { + BaseLayer + Type SCTPChunkType + Flags uint8 + Length uint16 + // ActualLength is the total length of an SCTP chunk, including padding. + // SCTP chunks start and end on 4-byte boundaries. So if a chunk has a length + // of 18, it means that it has data up to and including byte 18, then padding + // up to the next 4-byte boundary, 20. In this case, Length would be 18, and + // ActualLength would be 20. + ActualLength int +} + +func roundUpToNearest4(i int) int { + if i%4 == 0 { + return i + } + return i + 4 - (i % 4) +} + +func decodeSCTPChunk(data []byte) (SCTPChunk, error) { + length := binary.BigEndian.Uint16(data[2:4]) + if length < 4 { + return SCTPChunk{}, errors.New("invalid SCTP chunk length") + } + actual := roundUpToNearest4(int(length)) + ct := SCTPChunkType(data[0]) + + // For SCTP Data, use a separate layer for the payload + delta := 0 + if ct == SCTPChunkTypeData { + delta = int(actual) - int(length) + actual = 16 + } + + return SCTPChunk{ + Type: ct, + Flags: data[1], + Length: length, + ActualLength: actual, + BaseLayer: BaseLayer{data[:actual], data[actual : len(data)-delta]}, + }, nil +} + +// SCTPParameter is a TLV parameter inside a SCTPChunk. +type SCTPParameter struct { + Type uint16 + Length uint16 + ActualLength int + Value []byte +} + +func decodeSCTPParameter(data []byte) SCTPParameter { + length := binary.BigEndian.Uint16(data[2:4]) + return SCTPParameter{ + Type: binary.BigEndian.Uint16(data[0:2]), + Length: length, + Value: data[4:length], + ActualLength: roundUpToNearest4(int(length)), + } +} + +func (p SCTPParameter) Bytes() []byte { + length := 4 + len(p.Value) + data := make([]byte, roundUpToNearest4(length)) + binary.BigEndian.PutUint16(data[0:2], p.Type) + binary.BigEndian.PutUint16(data[2:4], uint16(length)) + copy(data[4:], p.Value) + return data +} + +// SCTPUnknownChunkType is the layer type returned when we don't recognize the +// chunk type. Since there's a length in a known location, we can skip over +// it even if we don't know what it is, and continue parsing the rest of the +// chunks. This chunk is stored as an ErrorLayer in the packet. +type SCTPUnknownChunkType struct { + SCTPChunk + bytes []byte +} + +func decodeSCTPChunkTypeUnknown(data []byte, p gopacket.PacketBuilder) error { + chunk, err := decodeSCTPChunk(data) + if err != nil { + return err + } + sc := &SCTPUnknownChunkType{SCTPChunk: chunk} + sc.bytes = data[:sc.ActualLength] + p.AddLayer(sc) + p.SetErrorLayer(sc) + return p.NextDecoder(gopacket.DecodeFunc(decodeWithSCTPChunkTypePrefix)) +} + +// SerializeTo is for gopacket.SerializableLayer. +func (s SCTPUnknownChunkType) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error { + bytes, err := b.PrependBytes(s.ActualLength) + if err != nil { + return err + } + copy(bytes, s.bytes) + return nil +} + +// LayerType returns gopacket.LayerTypeSCTPUnknownChunkType. +func (s *SCTPUnknownChunkType) LayerType() gopacket.LayerType { return LayerTypeSCTPUnknownChunkType } + +// Payload returns all bytes in this header, including the decoded Type, Length, +// and Flags. +func (s *SCTPUnknownChunkType) Payload() []byte { return s.bytes } + +// Error implements ErrorLayer. +func (s *SCTPUnknownChunkType) Error() error { + return fmt.Errorf("No decode method available for SCTP chunk type %s", s.Type) +} + +// SCTPData is the SCTP Data chunk layer. +type SCTPData struct { + SCTPChunk + Unordered, BeginFragment, EndFragment bool + TSN uint32 + StreamId uint16 + StreamSequence uint16 + PayloadProtocol SCTPPayloadProtocol +} + +// LayerType returns gopacket.LayerTypeSCTPData. +func (s *SCTPData) LayerType() gopacket.LayerType { return LayerTypeSCTPData } + +// SCTPPayloadProtocol represents a payload protocol +type SCTPPayloadProtocol uint32 + +// SCTPPayloadProtocol constonts from http://www.iana.org/assignments/sctp-parameters/sctp-parameters.xhtml +const ( + SCTPProtocolReserved SCTPPayloadProtocol = 0 + SCTPPayloadUIA = 1 + SCTPPayloadM2UA = 2 + SCTPPayloadM3UA = 3 + SCTPPayloadSUA = 4 + SCTPPayloadM2PA = 5 + SCTPPayloadV5UA = 6 + SCTPPayloadH248 = 7 + SCTPPayloadBICC = 8 + SCTPPayloadTALI = 9 + SCTPPayloadDUA = 10 + SCTPPayloadASAP = 11 + SCTPPayloadENRP = 12 + SCTPPayloadH323 = 13 + SCTPPayloadQIPC = 14 + SCTPPayloadSIMCO = 15 + SCTPPayloadDDPSegment = 16 + SCTPPayloadDDPStream = 17 + SCTPPayloadS1AP = 18 +) + +func (p SCTPPayloadProtocol) String() string { + switch p { + case SCTPProtocolReserved: + return "Reserved" + case SCTPPayloadUIA: + return "UIA" + case SCTPPayloadM2UA: + return "M2UA" + case SCTPPayloadM3UA: + return "M3UA" + case SCTPPayloadSUA: + return "SUA" + case SCTPPayloadM2PA: + return "M2PA" + case SCTPPayloadV5UA: + return "V5UA" + case SCTPPayloadH248: + return "H.248" + case SCTPPayloadBICC: + return "BICC" + case SCTPPayloadTALI: + return "TALI" + case SCTPPayloadDUA: + return "DUA" + case SCTPPayloadASAP: + return "ASAP" + case SCTPPayloadENRP: + return "ENRP" + case SCTPPayloadH323: + return "H.323" + case SCTPPayloadQIPC: + return "QIPC" + case SCTPPayloadSIMCO: + return "SIMCO" + case SCTPPayloadDDPSegment: + return "DDPSegment" + case SCTPPayloadDDPStream: + return "DDPStream" + case SCTPPayloadS1AP: + return "S1AP" + } + return fmt.Sprintf("Unknown(%d)", p) +} + +func decodeSCTPData(data []byte, p gopacket.PacketBuilder) error { + chunk, err := decodeSCTPChunk(data) + if err != nil { + return err + } + sc := &SCTPData{ + SCTPChunk: chunk, + Unordered: data[1]&0x4 != 0, + BeginFragment: data[1]&0x2 != 0, + EndFragment: data[1]&0x1 != 0, + TSN: binary.BigEndian.Uint32(data[4:8]), + StreamId: binary.BigEndian.Uint16(data[8:10]), + StreamSequence: binary.BigEndian.Uint16(data[10:12]), + PayloadProtocol: SCTPPayloadProtocol(binary.BigEndian.Uint32(data[12:16])), + } + // Length is the length in bytes of the data, INCLUDING the 16-byte header. + p.AddLayer(sc) + return p.NextDecoder(gopacket.LayerTypePayload) +} + +// SerializeTo is for gopacket.SerializableLayer. +func (sc SCTPData) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error { + payload := b.Bytes() + // Pad the payload to a 32 bit boundary + if rem := len(payload) % 4; rem != 0 { + b.AppendBytes(4 - rem) + } + length := 16 + bytes, err := b.PrependBytes(length) + if err != nil { + return err + } + bytes[0] = uint8(sc.Type) + flags := uint8(0) + if sc.Unordered { + flags |= 0x4 + } + if sc.BeginFragment { + flags |= 0x2 + } + if sc.EndFragment { + flags |= 0x1 + } + bytes[1] = flags + binary.BigEndian.PutUint16(bytes[2:4], uint16(length+len(payload))) + binary.BigEndian.PutUint32(bytes[4:8], sc.TSN) + binary.BigEndian.PutUint16(bytes[8:10], sc.StreamId) + binary.BigEndian.PutUint16(bytes[10:12], sc.StreamSequence) + binary.BigEndian.PutUint32(bytes[12:16], uint32(sc.PayloadProtocol)) + return nil +} + +// SCTPInitParameter is a parameter for an SCTP Init or InitAck packet. +type SCTPInitParameter SCTPParameter + +// SCTPInit is used as the return value for both SCTPInit and SCTPInitAck +// messages. +type SCTPInit struct { + SCTPChunk + InitiateTag uint32 + AdvertisedReceiverWindowCredit uint32 + OutboundStreams, InboundStreams uint16 + InitialTSN uint32 + Parameters []SCTPInitParameter +} + +// LayerType returns either gopacket.LayerTypeSCTPInit or gopacket.LayerTypeSCTPInitAck. +func (sc *SCTPInit) LayerType() gopacket.LayerType { + if sc.Type == SCTPChunkTypeInitAck { + return LayerTypeSCTPInitAck + } + // 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 +} -- cgit 1.2.3-korg