vendor/github.com/google/gopacket/layers/icmp4.go

   1 // Copyright 2012 Google, Inc. All rights reserved.
   2 // Copyright 2009-2011 Andreas Krennmair. All rights reserved.
   3 //
   4 // Use of this source code is governed by a BSD-style license
   5 // that can be found in the LICENSE file in the root of the source
   6 // tree.
   7
   8 package layers
   9
  10 import (
  11         "encoding/binary"
  12         "errors"
  13         "fmt"
  14         "reflect"
  15
  16         "github.com/google/gopacket"
  17 )
  18
  19 const (
  20         ICMPv4TypeEchoReply              = 0
  21         ICMPv4TypeDestinationUnreachable = 3
  22         ICMPv4TypeSourceQuench           = 4
  23         ICMPv4TypeRedirect               = 5
  24         ICMPv4TypeEchoRequest            = 8
  25         ICMPv4TypeRouterAdvertisement    = 9
  26         ICMPv4TypeRouterSolicitation     = 10
  27         ICMPv4TypeTimeExceeded           = 11
  28         ICMPv4TypeParameterProblem       = 12
  29         ICMPv4TypeTimestampRequest       = 13
  30         ICMPv4TypeTimestampReply         = 14
  31         ICMPv4TypeInfoRequest            = 15
  32         ICMPv4TypeInfoReply              = 16
  33         ICMPv4TypeAddressMaskRequest     = 17
  34         ICMPv4TypeAddressMaskReply       = 18
  35 )
  36
  37 const (
  38         // DestinationUnreachable
  39         ICMPv4CodeNet                 = 0
  40         ICMPv4CodeHost                = 1
  41         ICMPv4CodeProtocol            = 2
  42         ICMPv4CodePort                = 3
  43         ICMPv4CodeFragmentationNeeded = 4
  44         ICMPv4CodeSourceRoutingFailed = 5
  45         ICMPv4CodeNetUnknown          = 6
  46         ICMPv4CodeHostUnknown         = 7
  47         ICMPv4CodeSourceIsolated      = 8
  48         ICMPv4CodeNetAdminProhibited  = 9
  49         ICMPv4CodeHostAdminProhibited = 10
  50         ICMPv4CodeNetTOS              = 11
  51         ICMPv4CodeHostTOS             = 12
  52         ICMPv4CodeCommAdminProhibited = 13
  53         ICMPv4CodeHostPrecedence      = 14
  54         ICMPv4CodePrecedenceCutoff    = 15
  55
  56         // TimeExceeded
  57         ICMPv4CodeTTLExceeded                    = 0
  58         ICMPv4CodeFragmentReassemblyTimeExceeded = 1
  59
  60         // ParameterProblem
  61         ICMPv4CodePointerIndicatesError = 0
  62         ICMPv4CodeMissingOption         = 1
  63         ICMPv4CodeBadLength             = 2
  64
  65         // Redirect
  66         // ICMPv4CodeNet  = same as for DestinationUnreachable
  67         // ICMPv4CodeHost = same as for DestinationUnreachable
  68         ICMPv4CodeTOSNet  = 2
  69         ICMPv4CodeTOSHost = 3
  70 )
  71
  72 type icmpv4TypeCodeInfoStruct struct {
  73         typeStr string
  74         codeStr *map[uint8]string
  75 }
  76
  77 var (
  78         icmpv4TypeCodeInfo = map[uint8]icmpv4TypeCodeInfoStruct{
  79                 ICMPv4TypeDestinationUnreachable: icmpv4TypeCodeInfoStruct{
  80                         "DestinationUnreachable", &map[uint8]string{
  81                                 ICMPv4CodeNet:                 "Net",
  82                                 ICMPv4CodeHost:                "Host",
  83                                 ICMPv4CodeProtocol:            "Protocol",
  84                                 ICMPv4CodePort:                "Port",
  85                                 ICMPv4CodeFragmentationNeeded: "FragmentationNeeded",
  86                                 ICMPv4CodeSourceRoutingFailed: "SourceRoutingFailed",
  87                                 ICMPv4CodeNetUnknown:          "NetUnknown",
  88                                 ICMPv4CodeHostUnknown:         "HostUnknown",
  89                                 ICMPv4CodeSourceIsolated:      "SourceIsolated",
  90                                 ICMPv4CodeNetAdminProhibited:  "NetAdminProhibited",
  91                                 ICMPv4CodeHostAdminProhibited: "HostAdminProhibited",
  92                                 ICMPv4CodeNetTOS:              "NetTOS",
  93                                 ICMPv4CodeHostTOS:             "HostTOS",
  94                                 ICMPv4CodeCommAdminProhibited: "CommAdminProhibited",
  95                                 ICMPv4CodeHostPrecedence:      "HostPrecedence",
  96                                 ICMPv4CodePrecedenceCutoff:    "PrecedenceCutoff",
  97                         },
  98                 },
  99                 ICMPv4TypeTimeExceeded: icmpv4TypeCodeInfoStruct{
 100                         "TimeExceeded", &map[uint8]string{
 101                                 ICMPv4CodeTTLExceeded:                    "TTLExceeded",
 102                                 ICMPv4CodeFragmentReassemblyTimeExceeded: "FragmentReassemblyTimeExceeded",
 103                         },
 104                 },
 105                 ICMPv4TypeParameterProblem: icmpv4TypeCodeInfoStruct{
 106                         "ParameterProblem", &map[uint8]string{
 107                                 ICMPv4CodePointerIndicatesError: "PointerIndicatesError",
 108                                 ICMPv4CodeMissingOption:         "MissingOption",
 109                                 ICMPv4CodeBadLength:             "BadLength",
 110                         },
 111                 },
 112                 ICMPv4TypeSourceQuench: icmpv4TypeCodeInfoStruct{
 113                         "SourceQuench", nil,
 114                 },
 115                 ICMPv4TypeRedirect: icmpv4TypeCodeInfoStruct{
 116                         "Redirect", &map[uint8]string{
 117                                 ICMPv4CodeNet:     "Net",
 118                                 ICMPv4CodeHost:    "Host",
 119                                 ICMPv4CodeTOSNet:  "TOS+Net",
 120                                 ICMPv4CodeTOSHost: "TOS+Host",
 121                         },
 122                 },
 123                 ICMPv4TypeEchoRequest: icmpv4TypeCodeInfoStruct{
 124                         "EchoRequest", nil,
 125                 },
 126                 ICMPv4TypeEchoReply: icmpv4TypeCodeInfoStruct{
 127                         "EchoReply", nil,
 128                 },
 129                 ICMPv4TypeTimestampRequest: icmpv4TypeCodeInfoStruct{
 130                         "TimestampRequest", nil,
 131                 },
 132                 ICMPv4TypeTimestampReply: icmpv4TypeCodeInfoStruct{
 133                         "TimestampReply", nil,
 134                 },
 135                 ICMPv4TypeInfoRequest: icmpv4TypeCodeInfoStruct{
 136                         "InfoRequest", nil,
 137                 },
 138                 ICMPv4TypeInfoReply: icmpv4TypeCodeInfoStruct{
 139                         "InfoReply", nil,
 140                 },
 141                 ICMPv4TypeRouterSolicitation: icmpv4TypeCodeInfoStruct{
 142                         "RouterSolicitation", nil,
 143                 },
 144                 ICMPv4TypeRouterAdvertisement: icmpv4TypeCodeInfoStruct{
 145                         "RouterAdvertisement", nil,
 146                 },
 147                 ICMPv4TypeAddressMaskRequest: icmpv4TypeCodeInfoStruct{
 148                         "AddressMaskRequest", nil,
 149                 },
 150                 ICMPv4TypeAddressMaskReply: icmpv4TypeCodeInfoStruct{
 151                         "AddressMaskReply", nil,
 152                 },
 153         }
 154 )
 155
 156 type ICMPv4TypeCode uint16
 157
 158 // Type returns the ICMPv4 type field.
 159 func (a ICMPv4TypeCode) Type() uint8 {
 160         return uint8(a >> 8)
 161 }
 162
 163 // Code returns the ICMPv4 code field.
 164 func (a ICMPv4TypeCode) Code() uint8 {
 165         return uint8(a)
 166 }
 167
 168 func (a ICMPv4TypeCode) String() string {
 169         t, c := a.Type(), a.Code()
 170         strInfo, ok := icmpv4TypeCodeInfo[t]
 171         if !ok {
 172                 // Unknown ICMPv4 type field
 173                 return fmt.Sprintf("%d(%d)", t, c)
 174         }
 175         typeStr := strInfo.typeStr
 176         if strInfo.codeStr == nil && c == 0 {
 177                 // The ICMPv4 type does not make use of the code field
 178                 return fmt.Sprintf("%s", strInfo.typeStr)
 179         }
 180         if strInfo.codeStr == nil && c != 0 {
 181                 // The ICMPv4 type does not make use of the code field, but it is present anyway
 182                 return fmt.Sprintf("%s(Code: %d)", typeStr, c)
 183         }
 184         codeStr, ok := (*strInfo.codeStr)[c]
 185         if !ok {
 186                 // We don't know this ICMPv4 code; print the numerical value
 187                 return fmt.Sprintf("%s(Code: %d)", typeStr, c)
 188         }
 189         return fmt.Sprintf("%s(%s)", typeStr, codeStr)
 190 }
 191
 192 func (a ICMPv4TypeCode) GoString() string {
 193         t := reflect.TypeOf(a)
 194         return fmt.Sprintf("%s(%d, %d)", t.String(), a.Type(), a.Code())
 195 }
 196
 197 // SerializeTo writes the ICMPv4TypeCode value to the 'bytes' buffer.
 198 func (a ICMPv4TypeCode) SerializeTo(bytes []byte) {
 199         binary.BigEndian.PutUint16(bytes, uint16(a))
 200 }
 201
 202 // CreateICMPv4TypeCode is a convenience function to create an ICMPv4TypeCode
 203 // gopacket type from the ICMPv4 type and code values.
 204 func CreateICMPv4TypeCode(typ uint8, code uint8) ICMPv4TypeCode {
 205         return ICMPv4TypeCode(binary.BigEndian.Uint16([]byte{typ, code}))
 206 }
 207
 208 // ICMPv4 is the layer for IPv4 ICMP packet data.
 209 type ICMPv4 struct {
 210         BaseLayer
 211         TypeCode ICMPv4TypeCode
 212         Checksum uint16
 213         Id       uint16
 214         Seq      uint16
 215 }
 216
 217 // LayerType returns LayerTypeICMPv4.
 218 func (i *ICMPv4) LayerType() gopacket.LayerType { return LayerTypeICMPv4 }
 219
 220 // DecodeFromBytes decodes the given bytes into this layer.
 221 func (i *ICMPv4) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
 222         if len(data) < 8 {
 223                 df.SetTruncated()
 224                 return errors.New("ICMP layer less then 8 bytes for ICMPv4 packet")
 225         }
 226         i.TypeCode = CreateICMPv4TypeCode(data[0], data[1])
 227         i.Checksum = binary.BigEndian.Uint16(data[2:4])
 228         i.Id = binary.BigEndian.Uint16(data[4:6])
 229         i.Seq = binary.BigEndian.Uint16(data[6:8])
 230         i.BaseLayer = BaseLayer{data[:8], data[8:]}
 231         return nil
 232 }
 233
 234 // SerializeTo writes the serialized form of this layer into the
 235 // SerializationBuffer, implementing gopacket.SerializableLayer.
 236 // See the docs for gopacket.SerializableLayer for more info.
 237 func (i *ICMPv4) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
 238         bytes, err := b.PrependBytes(8)
 239         if err != nil {
 240                 return err
 241         }
 242         i.TypeCode.SerializeTo(bytes)
 243         binary.BigEndian.PutUint16(bytes[4:], i.Id)
 244         binary.BigEndian.PutUint16(bytes[6:], i.Seq)
 245         if opts.ComputeChecksums {
 246                 bytes[2] = 0
 247                 bytes[3] = 0
 248                 i.Checksum = tcpipChecksum(b.Bytes(), 0)
 249         }
 250         binary.BigEndian.PutUint16(bytes[2:], i.Checksum)
 251         return nil
 252 }
 253
 254 // CanDecode returns the set of layer types that this DecodingLayer can decode.
 255 func (i *ICMPv4) CanDecode() gopacket.LayerClass {
 256         return LayerTypeICMPv4
 257 }
 258
 259 // NextLayerType returns the layer type contained by this DecodingLayer.
 260 func (i *ICMPv4) NextLayerType() gopacket.LayerType {
 261         return gopacket.LayerTypePayload
 262 }
 263
 264 func decodeICMPv4(data []byte, p gopacket.PacketBuilder) error {
 265         i := &ICMPv4{}
 266         return decodingLayerDecoder(i, data, p)
 267 }