private void FinalizeLayers(byte[] buffer, int length)
{
int offset = length;
for (int i = _layers.Length - 1; i >= 0; --i)
{
ILayer layer = _layers[i];
ILayer nextLayer = i == _layers.Length - 1 ? null : _layers[i + 1];
offset -= layer.Length;
layer.Finalize(buffer, offset, length - offset - layer.Length, nextLayer);
}
}
private void FinalizeLayers(byte[] buffer, int length)
{
int offset = length;
for (int index = this._layers.Length - 1; index >= 0; --index)
{
ILayer layer = this._layers[index];
ILayer nextLayer = index == this._layers.Length - 1 ? (ILayer)null : this._layers[index + 1];
offset -= layer.Length;
layer.Finalize(buffer, offset, length - offset - layer.Length, nextLayer);
}
}
public void RandomIcmpTest()
{
EthernetLayer ethernetLayer = new EthernetLayer
{
Source = new MacAddress("00:01:02:03:04:05"),
Destination = new MacAddress("A0:A1:A2:A3:A4:A5")
};
int seed = new Random().Next();
Console.WriteLine("Seed: " + seed);
Random random = new Random(seed);
for (int i = 0; i != 2000; ++i)
{
IpV4Layer ipV4Layer = random.NextIpV4Layer(null);
ipV4Layer.HeaderChecksum = null;
Layer ipLayer = random.NextBool() ? (Layer)ipV4Layer : random.NextIpV6Layer(IpV4Protocol.InternetControlMessageProtocol, false);
IcmpLayer icmpLayer = random.NextIcmpLayer();
icmpLayer.Checksum = null;
if (icmpLayer.MessageType == IcmpMessageType.DestinationUnreachable &&
icmpLayer.MessageTypeAndCode != IcmpMessageTypeAndCode.DestinationUnreachableFragmentationNeededAndDoNotFragmentSet)
{
((IcmpDestinationUnreachableLayer)icmpLayer).NextHopMaximumTransmissionUnit = 0;
}
IEnumerable <ILayer> icmpPayloadLayers = random.NextIcmpPayloadLayers(icmpLayer);
int icmpPayloadLength = icmpPayloadLayers.Select(layer => layer.Length).Sum();
switch (icmpLayer.MessageType)
{
case IcmpMessageType.ParameterProblem:
if (icmpPayloadLength % 4 != 0)
{
icmpPayloadLayers = icmpPayloadLayers.Concat(new[] { new PayloadLayer {
Data = random.NextDatagram(4 - icmpPayloadLength % 4)
} });
}
icmpPayloadLength = icmpPayloadLayers.Select(layer => layer.Length).Sum();
IcmpParameterProblemLayer icmpParameterProblemLayer = (IcmpParameterProblemLayer)icmpLayer;
icmpParameterProblemLayer.Pointer = (byte)(icmpParameterProblemLayer.Pointer % icmpPayloadLength);
icmpParameterProblemLayer.OriginalDatagramLength = icmpPayloadLength - icmpPayloadLayers.First().Length;
break;
case IcmpMessageType.SecurityFailures:
((IcmpSecurityFailuresLayer)icmpLayer).Pointer %= (ushort)icmpPayloadLength;
break;
}
PacketBuilder packetBuilder = new PacketBuilder(new ILayer[] { ethernetLayer, ipLayer, icmpLayer }.Concat(icmpPayloadLayers));
Packet packet = packetBuilder.Build(DateTime.Now);
Assert.IsTrue(packet.IsValid, "IsValid");
byte[] buffer = (byte[])packet.Buffer.Clone();
buffer.Write(ethernetLayer.Length + ipLayer.Length, random.NextDatagram(icmpLayer.Length));
Packet illegalPacket = new Packet(buffer, DateTime.Now, packet.DataLink);
Assert.IsFalse(illegalPacket.IsValid, "IsInvalid");
if (illegalPacket.Ethernet.Ip.Icmp is IcmpUnknownDatagram)
{
byte[] icmpBuffer = new byte[illegalPacket.Ethernet.Ip.Icmp.ExtractLayer().Length];
ILayer layer = illegalPacket.Ethernet.Ip.Icmp.ExtractLayer();
layer.Write(icmpBuffer, 0, icmpBuffer.Length, null, null);
layer.Finalize(icmpBuffer, 0, icmpBuffer.Length, null);
MoreAssert.AreSequenceEqual(illegalPacket.Ethernet.Ip.Icmp.ToArray(),
icmpBuffer);
Assert.AreEqual(illegalPacket,
PacketBuilder.Build(DateTime.Now, ethernetLayer, ipLayer, illegalPacket.Ethernet.Ip.Icmp.ExtractLayer()));
}
// Ethernet
ethernetLayer.EtherType = ipLayer == ipV4Layer ? EthernetType.IpV4 : EthernetType.IpV6;
Assert.AreEqual(ethernetLayer, packet.Ethernet.ExtractLayer(), "Ethernet Layer");
ethernetLayer.EtherType = EthernetType.None;
// IP.
if (ipLayer == ipV4Layer)
{
// IPv4.
ipV4Layer.Protocol = IpV4Protocol.InternetControlMessageProtocol;
ipV4Layer.HeaderChecksum = ((IpV4Layer)packet.Ethernet.IpV4.ExtractLayer()).HeaderChecksum;
Assert.AreEqual(ipV4Layer, packet.Ethernet.IpV4.ExtractLayer());
ipV4Layer.HeaderChecksum = null;
Assert.AreEqual(ipV4Layer.Length, packet.Ethernet.IpV4.HeaderLength);
Assert.IsTrue(packet.Ethernet.IpV4.IsHeaderChecksumCorrect);
Assert.AreEqual(ipV4Layer.Length + icmpLayer.Length + icmpPayloadLength,
packet.Ethernet.IpV4.TotalLength);
Assert.AreEqual(IpV4Datagram.DefaultVersion, packet.Ethernet.IpV4.Version);
}
else
{
// IPv6.
Assert.AreEqual(ipLayer, packet.Ethernet.IpV6.ExtractLayer());
}
// ICMP
IcmpDatagram actualIcmp = packet.Ethernet.Ip.Icmp;
IcmpLayer actualIcmpLayer = (IcmpLayer)actualIcmp.ExtractLayer();
icmpLayer.Checksum = actualIcmpLayer.Checksum;
Assert.AreEqual(icmpLayer, actualIcmpLayer);
Assert.AreEqual(icmpLayer.GetHashCode(), actualIcmpLayer.GetHashCode());
if (actualIcmpLayer.MessageType != IcmpMessageType.RouterSolicitation)
{
Assert.AreNotEqual(random.NextIcmpLayer(), actualIcmpLayer);
IcmpLayer otherIcmpLayer = random.NextIcmpLayer();
Assert.AreNotEqual(otherIcmpLayer.GetHashCode(), actualIcmpLayer.GetHashCode());
}
Assert.IsTrue(actualIcmp.IsChecksumCorrect);
Assert.AreEqual(icmpLayer.MessageType, actualIcmp.MessageType);
Assert.AreEqual(icmpLayer.CodeValue, actualIcmp.Code);
Assert.AreEqual(icmpLayer.MessageTypeAndCode, actualIcmp.MessageTypeAndCode);
Assert.AreEqual(packet.Length - ethernetLayer.Length - ipLayer.Length - IcmpDatagram.HeaderLength, actualIcmp.Payload.Length);
Assert.IsNotNull(icmpLayer.ToString());
switch (packet.Ethernet.Ip.Icmp.MessageType)
{
case IcmpMessageType.RouterSolicitation:
case IcmpMessageType.SourceQuench:
case IcmpMessageType.TimeExceeded:
Assert.AreEqual <uint>(0, actualIcmp.Variable);
break;
case IcmpMessageType.DestinationUnreachable:
case IcmpMessageType.ParameterProblem:
case IcmpMessageType.Redirect:
case IcmpMessageType.ConversionFailed:
case IcmpMessageType.Echo:
case IcmpMessageType.EchoReply:
case IcmpMessageType.Timestamp:
case IcmpMessageType.TimestampReply:
case IcmpMessageType.InformationRequest:
case IcmpMessageType.InformationReply:
case IcmpMessageType.RouterAdvertisement:
case IcmpMessageType.AddressMaskRequest:
case IcmpMessageType.AddressMaskReply:
break;
case IcmpMessageType.TraceRoute:
Assert.AreEqual(((IcmpTraceRouteLayer)icmpLayer).ReturnHopCount == 0xFFFF, ((IcmpTraceRouteDatagram)actualIcmp).IsOutbound);
break;
case IcmpMessageType.DomainNameRequest:
case IcmpMessageType.SecurityFailures:
break;
case IcmpMessageType.DomainNameReply:
default:
throw new InvalidOperationException("Invalid icmpMessageType " + packet.Ethernet.Ip.Icmp.MessageType);
}
}
}