346 lines
12 KiB
C#
346 lines
12 KiB
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 Chris Morgan <chmorgan@gmail.com>
|
||
|
|
*/
|
||
|
|
using System;
|
||
|
|
using System.Collections.Generic;
|
||
|
|
using System.Text;
|
||
|
|
using PacketDotNet.Utils;
|
||
|
|
using MiscUtil.Conversion;
|
||
|
|
|
||
|
|
namespace PacketDotNet
|
||
|
|
{
|
||
|
|
/// <summary>
|
||
|
|
/// User datagram protocol
|
||
|
|
/// See http://en.wikipedia.org/wiki/Udp
|
||
|
|
/// </summary>
|
||
|
|
public class UdpPacket : TransportPacket
|
||
|
|
{
|
||
|
|
// 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
|
||
|
|
|
||
|
|
/// <summary> Fetch the port number on the source host.</summary>
|
||
|
|
virtual public ushort SourcePort
|
||
|
|
{
|
||
|
|
get
|
||
|
|
{
|
||
|
|
return EndianBitConverter.Big.ToUInt16(header.Bytes, header.Offset + UdpFields.SourcePortPosition);
|
||
|
|
}
|
||
|
|
|
||
|
|
set
|
||
|
|
{
|
||
|
|
var val = value;
|
||
|
|
EndianBitConverter.Big.CopyBytes(val, header.Bytes, header.Offset + UdpFields.SourcePortPosition);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary> Fetch the port number on the target host.</summary>
|
||
|
|
virtual public ushort DestinationPort
|
||
|
|
{
|
||
|
|
get
|
||
|
|
{
|
||
|
|
return EndianBitConverter.Big.ToUInt16(header.Bytes,
|
||
|
|
header.Offset + UdpFields.DestinationPortPosition);
|
||
|
|
}
|
||
|
|
|
||
|
|
set
|
||
|
|
{
|
||
|
|
var val = value;
|
||
|
|
EndianBitConverter.Big.CopyBytes(val,
|
||
|
|
header.Bytes,
|
||
|
|
header.Offset + UdpFields.DestinationPortPosition);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <value>
|
||
|
|
/// Length in bytes of the header and payload, minimum size of 8,
|
||
|
|
/// the size of the Udp header
|
||
|
|
/// </value>
|
||
|
|
virtual public int Length
|
||
|
|
{
|
||
|
|
get
|
||
|
|
{
|
||
|
|
return EndianBitConverter.Big.ToInt16(header.Bytes,
|
||
|
|
header.Offset + UdpFields.HeaderLengthPosition);
|
||
|
|
}
|
||
|
|
|
||
|
|
// Internal because it is updated based on the payload when
|
||
|
|
// its bytes are retrieved
|
||
|
|
internal set
|
||
|
|
{
|
||
|
|
var val = (Int16)value;
|
||
|
|
EndianBitConverter.Big.CopyBytes(val,
|
||
|
|
header.Bytes,
|
||
|
|
header.Offset + UdpFields.HeaderLengthPosition);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary> Fetch the header checksum.</summary>
|
||
|
|
override public ushort Checksum
|
||
|
|
{
|
||
|
|
get
|
||
|
|
{
|
||
|
|
return EndianBitConverter.Big.ToUInt16(header.Bytes,
|
||
|
|
header.Offset + UdpFields.ChecksumPosition);
|
||
|
|
}
|
||
|
|
|
||
|
|
set
|
||
|
|
{
|
||
|
|
var val = value;
|
||
|
|
EndianBitConverter.Big.CopyBytes(val,
|
||
|
|
header.Bytes,
|
||
|
|
header.Offset + UdpFields.ChecksumPosition);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary> Check if the UDP packet is valid, checksum-wise.</summary>
|
||
|
|
public bool ValidChecksum
|
||
|
|
{
|
||
|
|
get
|
||
|
|
{
|
||
|
|
// IPv6 has no checksum so only the TCP checksum needs evaluation
|
||
|
|
if (ParentPacket.GetType() == typeof(IPv6Packet))
|
||
|
|
return ValidUDPChecksum;
|
||
|
|
// For IPv4 both the IP layer and the TCP layer contain checksums
|
||
|
|
else
|
||
|
|
return ((IPv4Packet)ParentPacket).ValidIPChecksum && ValidUDPChecksum;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <value>
|
||
|
|
/// True if the udp checksum is valid
|
||
|
|
/// </value>
|
||
|
|
virtual public bool ValidUDPChecksum
|
||
|
|
{
|
||
|
|
get
|
||
|
|
{
|
||
|
|
log.Debug("ValidUDPChecksum");
|
||
|
|
var retval = IsValidChecksum(TransportPacket.TransportChecksumOption.AttachPseudoIPHeader);
|
||
|
|
log.DebugFormat("ValidUDPChecksum {0}", retval);
|
||
|
|
return retval;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary> Fetch ascii escape sequence of the color associated with this packet type.</summary>
|
||
|
|
override public System.String Color
|
||
|
|
{
|
||
|
|
get
|
||
|
|
{
|
||
|
|
return AnsiEscapeSequences.LightGreen;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Update the Udp length
|
||
|
|
/// </summary>
|
||
|
|
public override void UpdateCalculatedValues ()
|
||
|
|
{
|
||
|
|
// update the length field based on the length of this packet header
|
||
|
|
// plus the length of all of the packets it contains
|
||
|
|
Length = TotalPacketLength;
|
||
|
|
|
||
|
|
UpdateUDPChecksum();
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Create from values
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="SourcePort">
|
||
|
|
/// A <see cref="System.UInt16"/>
|
||
|
|
/// </param>
|
||
|
|
/// <param name="DestinationPort">
|
||
|
|
/// A <see cref="System.UInt16"/>
|
||
|
|
/// </param>
|
||
|
|
public UdpPacket(ushort SourcePort, ushort DestinationPort)
|
||
|
|
{
|
||
|
|
log.Debug("");
|
||
|
|
|
||
|
|
// allocate memory for this packet
|
||
|
|
int offset = 0;
|
||
|
|
int length = UdpFields.HeaderLength;
|
||
|
|
var headerBytes = new byte[length];
|
||
|
|
header = new ByteArraySegment(headerBytes, offset, length);
|
||
|
|
|
||
|
|
// set instance values
|
||
|
|
this.SourcePort = SourcePort;
|
||
|
|
this.DestinationPort = DestinationPort;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Constructor
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="bas">
|
||
|
|
/// A <see cref="ByteArraySegment"/>
|
||
|
|
/// </param>
|
||
|
|
public UdpPacket(ByteArraySegment bas)
|
||
|
|
{
|
||
|
|
log.DebugFormat("bas {0}", bas.ToString());
|
||
|
|
|
||
|
|
// set the header field, header field values are retrieved from this byte array
|
||
|
|
header = new ByteArraySegment(bas);
|
||
|
|
RandomUtils.EnsurePacketLength(this, UdpFields.HeaderLength, header.Length);
|
||
|
|
header.Length = UdpFields.HeaderLength;
|
||
|
|
|
||
|
|
payloadPacketOrData = new PacketOrByteArraySegment();
|
||
|
|
|
||
|
|
// is this packet going to port 7 or 9? if so it might be a WakeOnLan packet
|
||
|
|
const int wakeOnLanPort0 = 7;
|
||
|
|
const int wakeOnLanPort1 = 9;
|
||
|
|
if(DestinationPort.Equals(wakeOnLanPort0) || DestinationPort.Equals (wakeOnLanPort1))
|
||
|
|
{
|
||
|
|
payloadPacketOrData.ThePacket = new WakeOnLanPacket(header.EncapsulatedBytes());
|
||
|
|
} else
|
||
|
|
{
|
||
|
|
// store the payload bytes
|
||
|
|
payloadPacketOrData.TheByteArraySegment = header.EncapsulatedBytes();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Constructor
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="bas">
|
||
|
|
/// A <see cref="ByteArraySegment"/>
|
||
|
|
/// </param>
|
||
|
|
/// <param name="ParentPacket">
|
||
|
|
/// A <see cref="Packet"/>
|
||
|
|
/// </param>
|
||
|
|
public UdpPacket(ByteArraySegment bas,
|
||
|
|
Packet ParentPacket) :
|
||
|
|
this(bas)
|
||
|
|
{
|
||
|
|
this.ParentPacket = ParentPacket;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Calculates the UDP checksum, optionally updating the UDP checksum header.
|
||
|
|
/// </summary>
|
||
|
|
/// <returns>The calculated UDP checksum.</returns>
|
||
|
|
public int CalculateUDPChecksum()
|
||
|
|
{
|
||
|
|
var newChecksum = CalculateChecksum(TransportChecksumOption.AttachPseudoIPHeader);
|
||
|
|
return newChecksum;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Update the checksum value.
|
||
|
|
/// </summary>
|
||
|
|
public void UpdateUDPChecksum()
|
||
|
|
{
|
||
|
|
this.Checksum = (ushort)CalculateUDPChecksum();
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <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)
|
||
|
|
{
|
||
|
|
buffer.AppendFormat("{0}[UDPPacket: SourcePort={2}, DestinationPort={3}]{1}",
|
||
|
|
color,
|
||
|
|
colorEscape,
|
||
|
|
SourcePort,
|
||
|
|
DestinationPort);
|
||
|
|
}
|
||
|
|
|
||
|
|
if(outputFormat == StringOutputType.Verbose || outputFormat == StringOutputType.VerboseColored)
|
||
|
|
{
|
||
|
|
// collect the properties and their value
|
||
|
|
Dictionary<string,string> properties = new Dictionary<string,string>();
|
||
|
|
properties.Add("source", SourcePort.ToString());
|
||
|
|
properties.Add("destination", DestinationPort.ToString());
|
||
|
|
properties.Add("length", Length.ToString());
|
||
|
|
properties.Add("checksum", "0x" + Checksum.ToString("x") + " [" + (ValidUDPChecksum ? "valid" : "invalid") + "]");
|
||
|
|
|
||
|
|
// 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("UDP: ******* UDP - \"User Datagram Protocol\" - offset=? length=" + TotalPacketLength);
|
||
|
|
buffer.AppendLine("UDP:");
|
||
|
|
foreach(var property in properties)
|
||
|
|
{
|
||
|
|
buffer.AppendLine("UDP: " + property.Key.PadLeft(padLength) + " = " + property.Value);
|
||
|
|
}
|
||
|
|
buffer.AppendLine("UDP:");
|
||
|
|
}
|
||
|
|
|
||
|
|
// append the base string output
|
||
|
|
buffer.Append(base.ToString(outputFormat));
|
||
|
|
|
||
|
|
return buffer.ToString();
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Returns the UdpPacket inside of the Packet p or null if
|
||
|
|
/// there is no encapsulated packet
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="p">
|
||
|
|
/// A <see cref="Packet"/>
|
||
|
|
/// </param>
|
||
|
|
/// <returns>
|
||
|
|
/// A <see cref="UdpPacket"/>
|
||
|
|
/// </returns>
|
||
|
|
[Obsolete("Use Packet.Extract() instead")]
|
||
|
|
public static UdpPacket GetEncapsulated(Packet p)
|
||
|
|
{
|
||
|
|
if(p is InternetLinkLayerPacket)
|
||
|
|
{
|
||
|
|
var payload = InternetLinkLayerPacket.GetInnerPayload((InternetLinkLayerPacket)p);
|
||
|
|
if(payload is IpPacket)
|
||
|
|
{
|
||
|
|
var innerPayload = payload.PayloadPacket;
|
||
|
|
if(innerPayload is UdpPacket)
|
||
|
|
{
|
||
|
|
return (UdpPacket)innerPayload;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return null;
|
||
|
|
}
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Generate a random packet
|
||
|
|
/// </summary>
|
||
|
|
/// <returns>
|
||
|
|
/// A <see cref="UdpPacket"/>
|
||
|
|
/// </returns>
|
||
|
|
public static UdpPacket RandomPacket()
|
||
|
|
{
|
||
|
|
var rnd = new Random();
|
||
|
|
var SourcePort = (ushort)rnd.Next(ushort.MinValue, ushort.MaxValue);
|
||
|
|
var DestinationPort = (ushort)rnd.Next(ushort.MinValue, ushort.MaxValue);
|
||
|
|
|
||
|
|
return new UdpPacket(SourcePort, DestinationPort);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|