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// Copyright 2012 Google, Inc. All rights reserved.
// Copyright 2009-2011 Andreas Krennmair. 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"
"reflect"
"github.com/google/gopacket"
)
const (
// The following are from RFC 4443
ICMPv6TypeDestinationUnreachable = 1
ICMPv6TypePacketTooBig = 2
ICMPv6TypeTimeExceeded = 3
ICMPv6TypeParameterProblem = 4
ICMPv6TypeEchoRequest = 128
ICMPv6TypeEchoReply = 129
// The following are from RFC 4861
ICMPv6TypeRouterSolicitation = 133
ICMPv6TypeRouterAdvertisement = 134
ICMPv6TypeNeighborSolicitation = 135
ICMPv6TypeNeighborAdvertisement = 136
ICMPv6TypeRedirect = 137
)
const (
// DestinationUnreachable
ICMPv6CodeNoRouteToDst = 0
ICMPv6CodeAdminProhibited = 1
ICMPv6CodeBeyondScopeOfSrc = 2
ICMPv6CodeAddressUnreachable = 3
ICMPv6CodePortUnreachable = 4
ICMPv6CodeSrcAddressFailedPolicy = 5
ICMPv6CodeRejectRouteToDst = 6
// TimeExceeded
ICMPv6CodeHopLimitExceeded = 0
ICMPv6CodeFragmentReassemblyTimeExceeded = 1
// ParameterProblem
ICMPv6CodeErroneousHeaderField = 0
ICMPv6CodeUnrecognizedNextHeader = 1
ICMPv6CodeUnrecognizedIPv6Option = 2
)
type icmpv6TypeCodeInfoStruct struct {
typeStr string
codeStr *map[uint8]string
}
var (
icmpv6TypeCodeInfo = map[uint8]icmpv6TypeCodeInfoStruct{
ICMPv6TypeDestinationUnreachable: icmpv6TypeCodeInfoStruct{
"DestinationUnreachable", &map[uint8]string{
ICMPv6CodeNoRouteToDst: "NoRouteToDst",
ICMPv6CodeAdminProhibited: "AdminProhibited",
ICMPv6CodeBeyondScopeOfSrc: "BeyondScopeOfSrc",
ICMPv6CodeAddressUnreachable: "AddressUnreachable",
ICMPv6CodePortUnreachable: "PortUnreachable",
ICMPv6CodeSrcAddressFailedPolicy: "SrcAddressFailedPolicy",
ICMPv6CodeRejectRouteToDst: "RejectRouteToDst",
},
},
ICMPv6TypePacketTooBig: icmpv6TypeCodeInfoStruct{
"PacketTooBig", nil,
},
ICMPv6TypeTimeExceeded: icmpv6TypeCodeInfoStruct{
"TimeExceeded", &map[uint8]string{
ICMPv6CodeHopLimitExceeded: "HopLimitExceeded",
ICMPv6CodeFragmentReassemblyTimeExceeded: "FragmentReassemblyTimeExceeded",
},
},
ICMPv6TypeParameterProblem: icmpv6TypeCodeInfoStruct{
"ParameterProblem", &map[uint8]string{
ICMPv6CodeErroneousHeaderField: "ErroneousHeaderField",
ICMPv6CodeUnrecognizedNextHeader: "UnrecognizedNextHeader",
ICMPv6CodeUnrecognizedIPv6Option: "UnrecognizedIPv6Option",
},
},
ICMPv6TypeEchoRequest: icmpv6TypeCodeInfoStruct{
"EchoRequest", nil,
},
ICMPv6TypeEchoReply: icmpv6TypeCodeInfoStruct{
"EchoReply", nil,
},
ICMPv6TypeRouterSolicitation: icmpv6TypeCodeInfoStruct{
"RouterSolicitation", nil,
},
ICMPv6TypeRouterAdvertisement: icmpv6TypeCodeInfoStruct{
"RouterAdvertisement", nil,
},
ICMPv6TypeNeighborSolicitation: icmpv6TypeCodeInfoStruct{
"NeighborSolicitation", nil,
},
ICMPv6TypeNeighborAdvertisement: icmpv6TypeCodeInfoStruct{
"NeighborAdvertisement", nil,
},
ICMPv6TypeRedirect: icmpv6TypeCodeInfoStruct{
"Redirect", nil,
},
}
)
type ICMPv6TypeCode uint16
// Type returns the ICMPv6 type field.
func (a ICMPv6TypeCode) Type() uint8 {
return uint8(a >> 8)
}
// Code returns the ICMPv6 code field.
func (a ICMPv6TypeCode) Code() uint8 {
return uint8(a)
}
func (a ICMPv6TypeCode) String() string {
t, c := a.Type(), a.Code()
strInfo, ok := icmpv6TypeCodeInfo[t]
if !ok {
// Unknown ICMPv6 type field
return fmt.Sprintf("%d(%d)", t, c)
}
typeStr := strInfo.typeStr
if strInfo.codeStr == nil && c == 0 {
// The ICMPv6 type does not make use of the code field
return fmt.Sprintf("%s", strInfo.typeStr)
}
if strInfo.codeStr == nil && c != 0 {
// The ICMPv6 type does not make use of the code field, but it is present anyway
return fmt.Sprintf("%s(Code: %d)", typeStr, c)
}
codeStr, ok := (*strInfo.codeStr)[c]
if !ok {
// We don't know this ICMPv6 code; print the numerical value
return fmt.Sprintf("%s(Code: %d)", typeStr, c)
}
return fmt.Sprintf("%s(%s)", typeStr, codeStr)
}
func (a ICMPv6TypeCode) GoString() string {
t := reflect.TypeOf(a)
return fmt.Sprintf("%s(%d, %d)", t.String(), a.Type(), a.Code())
}
// SerializeTo writes the ICMPv6TypeCode value to the 'bytes' buffer.
func (a ICMPv6TypeCode) SerializeTo(bytes []byte) {
binary.BigEndian.PutUint16(bytes, uint16(a))
}
// CreateICMPv6TypeCode is a convenience function to create an ICMPv6TypeCode
// gopacket type from the ICMPv6 type and code values.
func CreateICMPv6TypeCode(typ uint8, code uint8) ICMPv6TypeCode {
return ICMPv6TypeCode(binary.BigEndian.Uint16([]byte{typ, code}))
}
// ICMPv6 is the layer for IPv6 ICMP packet data
type ICMPv6 struct {
BaseLayer
TypeCode ICMPv6TypeCode
Checksum uint16
TypeBytes []byte
tcpipchecksum
}
// LayerType returns LayerTypeICMPv6.
func (i *ICMPv6) LayerType() gopacket.LayerType { return LayerTypeICMPv6 }
// DecodeFromBytes decodes the given bytes into this layer.
func (i *ICMPv6) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
if len(data) < 8 {
df.SetTruncated()
return errors.New("ICMP layer less then 8 bytes for ICMPv6 packet")
}
i.TypeCode = CreateICMPv6TypeCode(data[0], data[1])
i.Checksum = binary.BigEndian.Uint16(data[2:4])
i.TypeBytes = data[4:8]
i.BaseLayer = BaseLayer{data[:8], data[8:]}
return nil
}
// SerializeTo writes the serialized form of this layer into the
// SerializationBuffer, implementing gopacket.SerializableLayer.
// See the docs for gopacket.SerializableLayer for more info.
func (i *ICMPv6) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
if i.TypeBytes == nil {
i.TypeBytes = lotsOfZeros[:4]
} else if len(i.TypeBytes) != 4 {
return fmt.Errorf("invalid type bytes for ICMPv6 packet: %v", i.TypeBytes)
}
bytes, err := b.PrependBytes(8)
if err != nil {
return err
}
i.TypeCode.SerializeTo(bytes)
copy(bytes[4:8], i.TypeBytes)
if opts.ComputeChecksums {
bytes[2] = 0
bytes[3] = 0
csum, err := i.computeChecksum(b.Bytes(), IPProtocolICMPv6)
if err != nil {
return err
}
i.Checksum = csum
}
binary.BigEndian.PutUint16(bytes[2:], i.Checksum)
return nil
}
// CanDecode returns the set of layer types that this DecodingLayer can decode.
func (i *ICMPv6) CanDecode() gopacket.LayerClass {
return LayerTypeICMPv6
}
// NextLayerType returns the layer type contained by this DecodingLayer.
func (i *ICMPv6) NextLayerType() gopacket.LayerType {
return gopacket.LayerTypePayload
}
func decodeICMPv6(data []byte, p gopacket.PacketBuilder) error {
i := &ICMPv6{}
return decodingLayerDecoder(i, data, p)
}
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