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C#

/*
This file is part of PacketDotNet
PacketDotNet is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
PacketDotNet is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with PacketDotNet. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* Copyright 2009 David Bond <mokon@mokon.net>
* Copyright 2009 Chris Morgan <chmorgan@gmail.com>
*/
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
using MiscUtil.Conversion;
using PacketDotNet.Utils;
namespace PacketDotNet
{
/// <summary>
/// IPv6 packet
///
/// References
/// ----------
/// http://tools.ietf.org/html/rfc2460
/// http://en.wikipedia.org/wiki/IPv6
/// </summary>
public class IPv6Packet : IpPacket
{
// NOTE: No need to warn about lack of use, the compiler won't
// put any calls to 'log' here but we need 'log' to exist to compile
#pragma warning disable 0169, 0649
private static readonly ILogInactive log;
#pragma warning restore 0169, 0649
/// <value>
/// Minimum number of bytes in an IPv6 header
/// </value>
public const int HeaderMinimumLength = 40;
/// <value>
/// The version of the IP protocol. The '6' in IPv6 indicates the version of the protocol
/// </value>
public static IpVersion ipVersion = IpVersion.IPv6;
private Int32 VersionTrafficClassFlowLabel
{
get
{
return EndianBitConverter.Big.ToInt32(header.Bytes,
header.Offset + IPv6Fields.VersionTrafficClassFlowLabelPosition);
}
set
{
EndianBitConverter.Big.CopyBytes(value, header.Bytes, header.Offset + IPv6Fields.VersionTrafficClassFlowLabelPosition);
}
}
/// <summary>
/// The version field of the IPv6 Packet.
/// </summary>
public override IpVersion Version
{
get
{
return (IpVersion)((VersionTrafficClassFlowLabel >> 28) & 0xF);
}
set
{
var theValue = (Int32)value;
// read the existing value
var field = (UInt32)VersionTrafficClassFlowLabel;
// mask the new field into place
field = (UInt32)((field & 0x0FFFFFFF) | ((theValue << 28) & 0xF0000000));
// write the updated value back
VersionTrafficClassFlowLabel = (int)field;
}
}
/// <summary>
/// The traffic class field of the IPv6 Packet.
/// </summary>
public virtual int TrafficClass
{
get
{
return ((VersionTrafficClassFlowLabel >> 20) & 0xFF);
}
set
{
// read the original value
var field = (UInt32)VersionTrafficClassFlowLabel;
// mask in the new field
field = (UInt32)(((field & 0xF00FFFFF) | (((UInt32)value) << 20 ) & 0x0FF00000));
// write the updated value back
VersionTrafficClassFlowLabel = (int)field;
}
}
/// <summary>
/// The flow label field of the IPv6 Packet.
/// </summary>
public virtual int FlowLabel
{
get
{
return (VersionTrafficClassFlowLabel & 0xFFFFF);
}
set
{
// read the original value
var field = (UInt32)VersionTrafficClassFlowLabel;
// make the value in
field = (UInt32)((field & 0xFFF00000) | ((UInt32)(value) & 0x000FFFFF));
// write the updated value back
VersionTrafficClassFlowLabel = (int)field;
}
}
/// <summary>
/// The payload lengeth field of the IPv6 Packet
/// NOTE: Differs from the IPv4 'Total length' field that includes the length of the header as
/// payload length is ONLY the size of the payload.
/// </summary>
public override ushort PayloadLength
{
get
{
return EndianBitConverter.Big.ToUInt16(header.Bytes,
header.Offset + IPv6Fields.PayloadLengthPosition);
}
set
{
EndianBitConverter.Big.CopyBytes(value,
header.Bytes,
header.Offset + IPv6Fields.PayloadLengthPosition);
}
}
/// <value>
/// Backwards compatibility property for IPv4.HeaderLength
/// NOTE: This field is the number of 32bit words
/// </value>
public override int HeaderLength
{
get
{
return (IPv6Fields.HeaderLength / 4);
}
set
{
throw new System.NotImplementedException ();
}
}
/// <value>
/// Backwards compatibility property for IPv4.TotalLength
/// </value>
public override int TotalLength
{
get
{
return PayloadLength + (HeaderLength * 4);
}
set
{
PayloadLength = (ushort)(value - (HeaderLength * 4));
}
}
/// <summary>
/// Identifies the protocol encapsulated by this packet
///
/// Replaces IPv4's 'protocol' field, has compatible values
/// </summary>
public override IPProtocolType NextHeader
{
get
{
return (IPProtocolType)(header.Bytes[header.Offset + IPv6Fields.NextHeaderPosition]);
}
set
{
header.Bytes[header.Offset + IPv6Fields.NextHeaderPosition] = (byte)value;
}
}
/// <value>
/// The protocol of the packet encapsulated in this ip packet
/// </value>
public override IPProtocolType Protocol
{
get { return NextHeader; }
set { NextHeader = value; }
}
/// <summary>
/// The hop limit field of the IPv6 Packet.
/// NOTE: Replaces the 'time to live' field of IPv4
///
/// 8-bit value
/// </summary>
public override int HopLimit
{
get
{
return header.Bytes[header.Offset + IPv6Fields.HopLimitPosition];
}
set
{
header.Bytes[header.Offset + IPv6Fields.HopLimitPosition] = (byte)value;
}
}
/// <value>
/// Helper alias for 'HopLimit'
/// </value>
public override int TimeToLive
{
get { return HopLimit; }
set { HopLimit = value; }
}
/// <summary>
/// The source address field of the IPv6 Packet.
/// </summary>
public override System.Net.IPAddress SourceAddress
{
get
{
return IpPacket.GetIPAddress(System.Net.Sockets.AddressFamily.InterNetworkV6,
header.Offset + IPv6Fields.SourceAddressPosition,
header.Bytes);
}
set
{
byte[] address = value.GetAddressBytes();
System.Array.Copy(address, 0,
header.Bytes, header.Offset + IPv6Fields.SourceAddressPosition,
address.Length);
}
}
/// <summary>
/// The destination address field of the IPv6 Packet.
/// </summary>
public override System.Net.IPAddress DestinationAddress
{
get
{
return IpPacket.GetIPAddress(System.Net.Sockets.AddressFamily.InterNetworkV6,
header.Offset + IPv6Fields.DestinationAddressPosition,
header.Bytes);
}
set
{
byte[] address = value.GetAddressBytes();
System.Array.Copy(address, 0,
header.Bytes, header.Offset + IPv6Fields.DestinationAddressPosition,
address.Length);
}
}
/// <summary>
/// Create an IPv6 packet from values
/// </summary>
/// <param name="SourceAddress">
/// A <see cref="System.Net.IPAddress"/>
/// </param>
/// <param name="DestinationAddress">
/// A <see cref="System.Net.IPAddress"/>
/// </param>
public IPv6Packet(System.Net.IPAddress SourceAddress,
System.Net.IPAddress DestinationAddress)
{
log.Debug("");
// allocate memory for this packet
int offset = 0;
int length = IPv6Fields.HeaderLength;
var headerBytes = new byte[length];
header = new ByteArraySegment(headerBytes, offset, length);
// set some default values to make this packet valid
PayloadLength = 0;
TimeToLive = DefaultTimeToLive;
// set instance values
this.SourceAddress = SourceAddress;
this.DestinationAddress = DestinationAddress;
this.Version = ipVersion;
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="bas">
/// A <see cref="ByteArraySegment"/>
/// </param>
public IPv6Packet(ByteArraySegment bas)
{
log.Debug(bas.ToString());
// slice off the header
header = new ByteArraySegment(bas);
RandomUtils.EnsurePacketLength(this, IPv6Fields.HeaderLength, header.Length);
// Base IPv6 header is always 40 bytes. Any extension headers
// should be processed based on the value of the `NextHeader` field
header.Length = IPv6Packet.HeaderMinimumLength;
// parse the payload
var payload = header.EncapsulatedBytes(PayloadLength);
payloadPacketOrData = IpPacket.ParseEncapsulatedBytes(payload,
NextHeader,
this);
}
/// <summary>
/// Prepend to the given byte[] origHeader the portion of the IPv6 header used for
/// generating an tcp checksum
///
/// http://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_checksum_using_IPv6
/// http://tools.ietf.org/html/rfc2460#page-27
/// </summary>
/// <param name="origHeader">
/// A <see cref="System.Byte"/>
/// </param>
/// <returns>
/// A <see cref="System.Byte"/>
/// </returns>
internal override byte[] AttachPseudoIPHeader(byte[] origHeader)
{
MemoryStream ms = new MemoryStream();
BinaryWriter bw = new BinaryWriter(ms);
// 0-16: ip src addr
bw.Write(header.Bytes, header.Offset + IPv6Fields.SourceAddressPosition,
IPv6Fields.AddressLength);
// 17-32: ip dst addr
bw.Write(header.Bytes, header.Offset + IPv6Fields.DestinationAddressPosition,
IPv6Fields.AddressLength);
// 33-36: TCP length
bw.Write((UInt32)System.Net.IPAddress.HostToNetworkOrder((Int32)origHeader.Length));
// 37-39: 3 bytes of zeros
bw.Write((byte)0);
bw.Write((byte)0);
bw.Write((byte)0);
// 40: Next header
bw.Write((byte)NextHeader);
// prefix the pseudoHeader to the header+data
byte[] pseudoHeader = ms.ToArray();
int headerSize = pseudoHeader.Length + origHeader.Length;
bool odd = origHeader.Length % 2 != 0;
if (odd)
headerSize++;
byte[] finalData = new byte[headerSize];
// copy the pseudo header in
Array.Copy(pseudoHeader, 0, finalData, 0, pseudoHeader.Length);
// copy the origHeader in
Array.Copy(origHeader, 0, finalData, pseudoHeader.Length, origHeader.Length);
//if not even length, pad with a zero
if (odd)
finalData[finalData.Length - 1] = 0;
return finalData;
}
/// <summary cref="Packet.ToString(StringOutputType)" />
public override string ToString(StringOutputType outputFormat)
{
var buffer = new StringBuilder();
string color = "";
string colorEscape = "";
if(outputFormat == StringOutputType.Colored || outputFormat == StringOutputType.VerboseColored)
{
color = Color;
colorEscape = AnsiEscapeSequences.Reset;
}
if(outputFormat == StringOutputType.Normal || outputFormat == StringOutputType.Colored)
{
// build the output string
buffer.AppendFormat("{0}[IPv6Packet: SourceAddress={2}, DestinationAddress={3}, NextHeader={4}]{1}",
color,
colorEscape,
SourceAddress,
DestinationAddress,
NextHeader);
}
if(outputFormat == StringOutputType.Verbose || outputFormat == StringOutputType.VerboseColored)
{
// collect the properties and their value
Dictionary<string,string> properties = new Dictionary<string,string>();
string ipVersion = Convert.ToString((int)Version, 2).PadLeft(4, '0');
properties.Add("version", ipVersion + " .... .... .... .... .... .... .... = " + (int)Version);
string trafficClass = Convert.ToString(TrafficClass, 2).PadLeft(8, '0').Insert(4, " ");
properties.Add("traffic class", ".... " + trafficClass + " .... .... .... .... .... = 0x" + TrafficClass.ToString("x").PadLeft(8, '0'));
string flowLabel = Convert.ToString(FlowLabel, 2).PadLeft(20, '0').Insert(16, " ").Insert(12, " ").Insert(8, " ").Insert(4, " ");
properties.Add("flow label", ".... .... .... " + flowLabel + " = 0x" + FlowLabel.ToString("x").PadLeft(8, '0'));
properties.Add("payload length", PayloadLength.ToString());
properties.Add("next header", NextHeader.ToString() + " (0x" + NextHeader.ToString("x") + ")");
properties.Add("hop limit", HopLimit.ToString());
properties.Add("source", SourceAddress.ToString());
properties.Add("destination", DestinationAddress.ToString());
// calculate the padding needed to right-justify the property names
int padLength = Utils.RandomUtils.LongestStringLength(new List<string>(properties.Keys));
// build the output string
buffer.AppendLine("IP: ******* IP - \"Internet Protocol (Version 6)\" - offset=? length=" + TotalPacketLength);
buffer.AppendLine("IP:");
foreach(var property in properties)
{
if(property.Key.Trim() != "")
{
buffer.AppendLine("IP: " + property.Key.PadLeft(padLength) + " = " + property.Value);
}
else
{
buffer.AppendLine("IP: " + property.Key.PadLeft(padLength) + " " + property.Value);
}
}
buffer.AppendLine("IP");
}
// append the base class output
buffer.Append(base.ToString(outputFormat));
return buffer.ToString();
}
/// <summary> Fetch ascii escape sequence of the color associated with this packet type.</summary>
override public String Color
{
get
{
return AnsiEscapeSequences.White;
}
}
/// <summary>
/// Generate a random packet
/// </summary>
/// <returns>
/// A <see cref="Packet"/>
/// </returns>
public static IPv6Packet RandomPacket()
{
var srcAddress = RandomUtils.GetIPAddress(ipVersion);
var dstAddress = RandomUtils.GetIPAddress(ipVersion);
return new IPv6Packet(srcAddress, dstAddress);
}
}
}