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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 (
ICMPv4TypeEchoReply = 0
ICMPv4TypeDestinationUnreachable = 3
ICMPv4TypeSourceQuench = 4
ICMPv4TypeRedirect = 5
ICMPv4TypeEchoRequest = 8
ICMPv4TypeRouterAdvertisement = 9
ICMPv4TypeRouterSolicitation = 10
ICMPv4TypeTimeExceeded = 11
ICMPv4TypeParameterProblem = 12
ICMPv4TypeTimestampRequest = 13
ICMPv4TypeTimestampReply = 14
ICMPv4TypeInfoRequest = 15
ICMPv4TypeInfoReply = 16
ICMPv4TypeAddressMaskRequest = 17
ICMPv4TypeAddressMaskReply = 18
)
const (
// DestinationUnreachable
ICMPv4CodeNet = 0
ICMPv4CodeHost = 1
ICMPv4CodeProtocol = 2
ICMPv4CodePort = 3
ICMPv4CodeFragmentationNeeded = 4
ICMPv4CodeSourceRoutingFailed = 5
ICMPv4CodeNetUnknown = 6
ICMPv4CodeHostUnknown = 7
ICMPv4CodeSourceIsolated = 8
ICMPv4CodeNetAdminProhibited = 9
ICMPv4CodeHostAdminProhibited = 10
ICMPv4CodeNetTOS = 11
ICMPv4CodeHostTOS = 12
ICMPv4CodeCommAdminProhibited = 13
ICMPv4CodeHostPrecedence = 14
ICMPv4CodePrecedenceCutoff = 15
// TimeExceeded
ICMPv4CodeTTLExceeded = 0
ICMPv4CodeFragmentReassemblyTimeExceeded = 1
// ParameterProblem
ICMPv4CodePointerIndicatesError = 0
ICMPv4CodeMissingOption = 1
ICMPv4CodeBadLength = 2
// Redirect
// ICMPv4CodeNet = same as for DestinationUnreachable
// ICMPv4CodeHost = same as for DestinationUnreachable
ICMPv4CodeTOSNet = 2
ICMPv4CodeTOSHost = 3
)
type icmpv4TypeCodeInfoStruct struct {
typeStr string
codeStr *map[uint8]string
}
var (
icmpv4TypeCodeInfo = map[uint8]icmpv4TypeCodeInfoStruct{
ICMPv4TypeDestinationUnreachable: icmpv4TypeCodeInfoStruct{
"DestinationUnreachable", &map[uint8]string{
ICMPv4CodeNet: "Net",
ICMPv4CodeHost: "Host",
ICMPv4CodeProtocol: "Protocol",
ICMPv4CodePort: "Port",
ICMPv4CodeFragmentationNeeded: "FragmentationNeeded",
ICMPv4CodeSourceRoutingFailed: "SourceRoutingFailed",
ICMPv4CodeNetUnknown: "NetUnknown",
ICMPv4CodeHostUnknown: "HostUnknown",
ICMPv4CodeSourceIsolated: "SourceIsolated",
ICMPv4CodeNetAdminProhibited: "NetAdminProhibited",
ICMPv4CodeHostAdminProhibited: "HostAdminProhibited",
ICMPv4CodeNetTOS: "NetTOS",
ICMPv4CodeHostTOS: "HostTOS",
ICMPv4CodeCommAdminProhibited: "CommAdminProhibited",
ICMPv4CodeHostPrecedence: "HostPrecedence",
ICMPv4CodePrecedenceCutoff: "PrecedenceCutoff",
},
},
ICMPv4TypeTimeExceeded: icmpv4TypeCodeInfoStruct{
"TimeExceeded", &map[uint8]string{
ICMPv4CodeTTLExceeded: "TTLExceeded",
ICMPv4CodeFragmentReassemblyTimeExceeded: "FragmentReassemblyTimeExceeded",
},
},
ICMPv4TypeParameterProblem: icmpv4TypeCodeInfoStruct{
"ParameterProblem", &map[uint8]string{
ICMPv4CodePointerIndicatesError: "PointerIndicatesError",
ICMPv4CodeMissingOption: "MissingOption",
ICMPv4CodeBadLength: "BadLength",
},
},
ICMPv4TypeSourceQuench: icmpv4TypeCodeInfoStruct{
"SourceQuench", nil,
},
ICMPv4TypeRedirect: icmpv4TypeCodeInfoStruct{
"Redirect", &map[uint8]string{
ICMPv4CodeNet: "Net",
ICMPv4CodeHost: "Host",
ICMPv4CodeTOSNet: "TOS+Net",
ICMPv4CodeTOSHost: "TOS+Host",
},
},
ICMPv4TypeEchoRequest: icmpv4TypeCodeInfoStruct{
"EchoRequest", nil,
},
ICMPv4TypeEchoReply: icmpv4TypeCodeInfoStruct{
"EchoReply", nil,
},
ICMPv4TypeTimestampRequest: icmpv4TypeCodeInfoStruct{
"TimestampRequest", nil,
},
ICMPv4TypeTimestampReply: icmpv4TypeCodeInfoStruct{
"TimestampReply", nil,
},
ICMPv4TypeInfoRequest: icmpv4TypeCodeInfoStruct{
"InfoRequest", nil,
},
ICMPv4TypeInfoReply: icmpv4TypeCodeInfoStruct{
"InfoReply", nil,
},
ICMPv4TypeRouterSolicitation: icmpv4TypeCodeInfoStruct{
"RouterSolicitation", nil,
},
ICMPv4TypeRouterAdvertisement: icmpv4TypeCodeInfoStruct{
"RouterAdvertisement", nil,
},
ICMPv4TypeAddressMaskRequest: icmpv4TypeCodeInfoStruct{
"AddressMaskRequest", nil,
},
ICMPv4TypeAddressMaskReply: icmpv4TypeCodeInfoStruct{
"AddressMaskReply", nil,
},
}
)
type ICMPv4TypeCode uint16
// Type returns the ICMPv4 type field.
func (a ICMPv4TypeCode) Type() uint8 {
return uint8(a >> 8)
}
// Code returns the ICMPv4 code field.
func (a ICMPv4TypeCode) Code() uint8 {
return uint8(a)
}
func (a ICMPv4TypeCode) String() string {
t, c := a.Type(), a.Code()
strInfo, ok := icmpv4TypeCodeInfo[t]
if !ok {
// Unknown ICMPv4 type field
return fmt.Sprintf("%d(%d)", t, c)
}
typeStr := strInfo.typeStr
if strInfo.codeStr == nil && c == 0 {
// The ICMPv4 type does not make use of the code field
return fmt.Sprintf("%s", strInfo.typeStr)
}
if strInfo.codeStr == nil && c != 0 {
// The ICMPv4 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 ICMPv4 code; print the numerical value
return fmt.Sprintf("%s(Code: %d)", typeStr, c)
}
return fmt.Sprintf("%s(%s)", typeStr, codeStr)
}
func (a ICMPv4TypeCode) GoString() string {
t := reflect.TypeOf(a)
return fmt.Sprintf("%s(%d, %d)", t.String(), a.Type(), a.Code())
}
// SerializeTo writes the ICMPv4TypeCode value to the 'bytes' buffer.
func (a ICMPv4TypeCode) SerializeTo(bytes []byte) {
binary.BigEndian.PutUint16(bytes, uint16(a))
}
// CreateICMPv4TypeCode is a convenience function to create an ICMPv4TypeCode
// gopacket type from the ICMPv4 type and code values.
func CreateICMPv4TypeCode(typ uint8, code uint8) ICMPv4TypeCode {
return ICMPv4TypeCode(binary.BigEndian.Uint16([]byte{typ, code}))
}
// ICMPv4 is the layer for IPv4 ICMP packet data.
type ICMPv4 struct {
BaseLayer
TypeCode ICMPv4TypeCode
Checksum uint16
Id uint16
Seq uint16
}
// LayerType returns LayerTypeICMPv4.
func (i *ICMPv4) LayerType() gopacket.LayerType { return LayerTypeICMPv4 }
// DecodeFromBytes decodes the given bytes into this layer.
func (i *ICMPv4) DecodeFromBytes(data []byte, df gopacket.DecodeFeedback) error {
if len(data) < 8 {
df.SetTruncated()
return errors.New("ICMP layer less then 8 bytes for ICMPv4 packet")
}
i.TypeCode = CreateICMPv4TypeCode(data[0], data[1])
i.Checksum = binary.BigEndian.Uint16(data[2:4])
i.Id = binary.BigEndian.Uint16(data[4:6])
i.Seq = binary.BigEndian.Uint16(data[6:8])
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 *ICMPv4) SerializeTo(b gopacket.SerializeBuffer, opts gopacket.SerializeOptions) error {
bytes, err := b.PrependBytes(8)
if err != nil {
return err
}
i.TypeCode.SerializeTo(bytes)
binary.BigEndian.PutUint16(bytes[4:], i.Id)
binary.BigEndian.PutUint16(bytes[6:], i.Seq)
if opts.ComputeChecksums {
bytes[2] = 0
bytes[3] = 0
i.Checksum = tcpipChecksum(b.Bytes(), 0)
}
binary.BigEndian.PutUint16(bytes[2:], i.Checksum)
return nil
}
// CanDecode returns the set of layer types that this DecodingLayer can decode.
func (i *ICMPv4) CanDecode() gopacket.LayerClass {
return LayerTypeICMPv4
}
// NextLayerType returns the layer type contained by this DecodingLayer.
func (i *ICMPv4) NextLayerType() gopacket.LayerType {
return gopacket.LayerTypePayload
}
func decodeICMPv4(data []byte, p gopacket.PacketBuilder) error {
i := &ICMPv4{}
return decodingLayerDecoder(i, data, p)
}