/// <summary>
/// This function build an IPv4 over GRE over IPv4 over Ethernet packet.
/// </summary>
public static Packet BuildGrePacket()
{
EthernetLayer ethernetLayer =
new EthernetLayer
{
Source = new MacAddress(macAddressSource),
Destination = new MacAddress(macAddressDest),
EtherType = EthernetType.None, // Will be filled automatically.
};
IpV4Layer ipV4Layer =
new IpV4Layer
{
Source = new IpV4Address(ipSource),
CurrentDestination = new IpV4Address(ipDest),
Fragmentation = IpV4Fragmentation.None,
HeaderChecksum = null, // Will be filled automatically.
Identification = 123,
Options = IpV4Options.None,
Protocol = null, // Will be filled automatically.
Ttl = 100,
TypeOfService = 0,
};
GreLayer greLayer =
new GreLayer
{
Version = GreVersion.Gre,
ProtocolType = EthernetType.None, // Will be filled automatically.
RecursionControl = 0,
FutureUseBits = 0,
ChecksumPresent = true,
Checksum = null, // Will be filled automatically.
Key = null,
SequenceNumber = 123,
AcknowledgmentSequenceNumber = null,
RoutingOffset = null,
Routing = null,
StrictSourceRoute = false,
};
IpV4Layer innerIpV4Layer =
new IpV4Layer
{
Source = new IpV4Address("100.200.201.202"),
CurrentDestination = new IpV4Address("123.254.132.40"),
Fragmentation = IpV4Fragmentation.None,
HeaderChecksum = null, // Will be filled automatically.
Identification = 123,
Options = IpV4Options.None,
Protocol = IpV4Protocol.Udp,
Ttl = 120,
TypeOfService = 0,
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, greLayer, innerIpV4Layer);
return(builder.Build(DateTime.Now));
}
private static void CreateRandomIpV4Payload(Random random, IpV4Layer ipV4Layer, List <ILayer> layers)
{
if (random.NextBool(20))
{
// Finish with payload.
PayloadLayer payloadLayer = random.NextPayloadLayer(random.Next(100));
layers.Add(payloadLayer);
return;
}
ipV4Layer.Protocol = null;
if (random.NextBool())
{
ipV4Layer.Fragmentation = IpV4Fragmentation.None;
}
switch (random.Next(0, 9))
{
case 0: // IpV4.
case 1:
IpV4Layer innerIpV4Layer = random.NextIpV4Layer();
layers.Add(innerIpV4Layer);
CreateRandomIpV4Payload(random, innerIpV4Layer, layers);
return;
case 2: // Igmp.
layers.Add(random.NextIgmpLayer());
return;
case 3: // Icmp.
IcmpLayer icmpLayer = random.NextIcmpLayer();
layers.Add(icmpLayer);
layers.AddRange(random.NextIcmpPayloadLayers(icmpLayer));
return;
case 4: // Gre.
GreLayer greLayer = random.NextGreLayer();
layers.Add(greLayer);
CreateRandomEthernetPayload(random, greLayer, layers);
return;
case 5: // Udp.
case 6:
UdpLayer udpLayer = random.NextUdpLayer();
layers.Add(udpLayer);
CreateRandomUdpPayload(random, udpLayer, layers);
return;
case 7: // Tcp.
case 8:
TcpLayer tcpLayer = random.NextTcpLayer();
layers.Add(tcpLayer);
CreateRandomTcpPayload(random, tcpLayer, layers);
return;
default:
throw new InvalidOperationException("Invalid value.");
}
}
public void RandomGreTest()
{
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 != 200; ++i)
{
IpV4Layer ipV4Layer = random.NextIpV4Layer(null);
ipV4Layer.HeaderChecksum = null;
Layer ipLayer = random.NextBool() ? (Layer)ipV4Layer : random.NextIpV6Layer(IpV4Protocol.Gre, false);
GreLayer greLayer = random.NextGreLayer();
PayloadLayer payloadLayer = random.NextPayloadLayer(random.Next(100));
PacketBuilder packetBuilder = new PacketBuilder(ethernetLayer, ipLayer, greLayer, payloadLayer);
Packet packet = packetBuilder.Build(DateTime.Now);
if (greLayer.Checksum == null &&
!new[] { EthernetType.IpV4, EthernetType.IpV6, EthernetType.Arp, EthernetType.VLanTaggedFrame }.Contains(packet.Ethernet.Ip.Gre.ProtocolType))
{
Assert.IsTrue(packet.IsValid, "IsValid, ProtocolType=" + packet.Ethernet.Ip.Gre.ProtocolType);
}
// 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.Gre;
ipV4Layer.HeaderChecksum = ((IpV4Layer)packet.Ethernet.Ip.ExtractLayer()).HeaderChecksum;
Assert.AreEqual(ipV4Layer, packet.Ethernet.Ip.ExtractLayer());
ipV4Layer.HeaderChecksum = null;
Assert.AreEqual(ipV4Layer.Length, packet.Ethernet.IpV4.HeaderLength);
Assert.IsTrue(packet.Ethernet.IpV4.IsHeaderChecksumCorrect);
Assert.AreEqual(ipV4Layer.Length + greLayer.Length + payloadLayer.Length,
packet.Ethernet.Ip.TotalLength);
Assert.AreEqual(IpV4Datagram.DefaultVersion, packet.Ethernet.Ip.Version);
}
else
{
// IPv6.
Assert.AreEqual(ipLayer, packet.Ethernet.Ip.ExtractLayer());
}
// GRE
GreDatagram actualGre = packet.Ethernet.Ip.Gre;
GreLayer actualGreLayer = (GreLayer)actualGre.ExtractLayer();
if (greLayer.ChecksumPresent && greLayer.Checksum == null)
{
Assert.IsTrue(actualGre.IsChecksumCorrect);
greLayer.Checksum = actualGre.Checksum;
}
Assert.AreEqual(greLayer, actualGreLayer, "Layer");
if (actualGreLayer.Key != null)
{
actualGreLayer.SetKey(actualGreLayer.KeyPayloadLength.Value, actualGreLayer.KeyCallId.Value);
}
else
{
Assert.IsNull(actualGreLayer.KeyPayloadLength);
Assert.IsNull(actualGreLayer.KeyCallId);
}
Assert.AreEqual(greLayer, actualGreLayer, "Layer");
if (actualGre.KeyPresent)
{
Assert.AreEqual(greLayer.KeyPayloadLength, actualGre.KeyPayloadLength, "KeyPayloadLength");
Assert.AreEqual(greLayer.KeyCallId, actualGre.KeyCallId, "KeyCallId");
}
Assert.AreNotEqual(random.NextGreLayer(), actualGreLayer, "Not Layer");
Assert.AreEqual(greLayer.Length, actualGre.HeaderLength);
Assert.IsTrue(actualGre.KeyPresent ^ (greLayer.Key == null));
MoreAssert.IsSmaller(8, actualGre.RecursionControl);
MoreAssert.IsSmaller(32, actualGre.FutureUseBits);
Assert.IsTrue(actualGre.RoutingPresent ^ (greLayer.Routing == null && greLayer.RoutingOffset == null));
Assert.IsTrue(actualGre.SequenceNumberPresent ^ (greLayer.SequenceNumber == null));
Assert.IsTrue(!actualGre.StrictSourceRoute || actualGre.RoutingPresent);
if (actualGre.RoutingPresent)
{
Assert.IsNotNull(actualGre.ActiveSourceRouteEntryIndex);
if (actualGre.ActiveSourceRouteEntryIndex < actualGre.Routing.Count)
{
Assert.IsNotNull(actualGre.ActiveSourceRouteEntry);
}
foreach (GreSourceRouteEntry entry in actualGre.Routing)
{
Assert.AreNotEqual(entry, 2);
Assert.AreEqual(entry.GetHashCode(), entry.GetHashCode());
switch (entry.AddressFamily)
{
case GreSourceRouteEntryAddressFamily.AsSourceRoute:
GreSourceRouteEntryAs asEntry = (GreSourceRouteEntryAs)entry;
MoreAssert.IsInRange(0, asEntry.AsNumbers.Count, asEntry.NextAsNumberIndex);
if (asEntry.NextAsNumberIndex != asEntry.AsNumbers.Count)
{
Assert.AreEqual(asEntry.AsNumbers[asEntry.NextAsNumberIndex], asEntry.NextAsNumber);
}
break;
case GreSourceRouteEntryAddressFamily.IpSourceRoute:
GreSourceRouteEntryIp ipEntry = (GreSourceRouteEntryIp)entry;
MoreAssert.IsInRange(0, ipEntry.Addresses.Count, ipEntry.NextAddressIndex);
if (ipEntry.NextAddressIndex != ipEntry.Addresses.Count)
{
Assert.AreEqual(ipEntry.Addresses[ipEntry.NextAddressIndex], ipEntry.NextAddress);
}
break;
default:
GreSourceRouteEntryUnknown unknownEntry = (GreSourceRouteEntryUnknown)entry;
MoreAssert.IsInRange(0, unknownEntry.Data.Length, unknownEntry.PayloadOffset);
break;
}
}
}
else
{
Assert.IsNull(actualGre.ActiveSourceRouteEntry);
}
Assert.IsNotNull(actualGre.Payload);
switch (actualGre.ProtocolType)
{
case EthernetType.IpV4:
Assert.IsNotNull(actualGre.IpV4);
break;
case EthernetType.Arp:
Assert.IsNotNull(actualGre.Arp);
break;
}
}
}
public void InvalidGreTest()
{
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 != 100; ++i)
{
IpV4Layer ipV4Layer = random.NextIpV4Layer(IpV4Protocol.Gre);
ipV4Layer.HeaderChecksum = null;
Layer ipLayer = random.NextBool() ? (Layer)ipV4Layer : random.NextIpV6Layer(IpV4Protocol.Gre, false);
GreLayer greLayer = random.NextGreLayer();
greLayer.Checksum = null;
greLayer.Routing = new List <GreSourceRouteEntry>
{
new GreSourceRouteEntryAs(new List <ushort> {
123
}.AsReadOnly(), 0),
new GreSourceRouteEntryIp(new List <IpV4Address> {
random.NextIpV4Address()
}.AsReadOnly(),
0)
}.AsReadOnly();
PacketBuilder packetBuilder = new PacketBuilder(ethernetLayer, ipLayer, greLayer);
Packet packet = packetBuilder.Build(DateTime.Now);
Assert.IsTrue(packet.IsValid ||
new[] { EthernetType.IpV4, EthernetType.IpV6, EthernetType.Arp, EthernetType.VLanTaggedFrame }.Contains(greLayer.ProtocolType),
"IsValid. ProtoclType=" + greLayer.ProtocolType);
GreDatagram gre = packet.Ethernet.Ip.Gre;
// Remove a byte from routing
Datagram newIpPayload = new Datagram(gre.Take(gre.Length - 1).ToArray());
packetBuilder = new PacketBuilder(ethernetLayer, ipLayer, new PayloadLayer {
Data = newIpPayload
});
packet = packetBuilder.Build(DateTime.Now);
Assert.IsNull(packet.Ethernet.Ip.Gre.Payload);
Assert.IsFalse(packet.IsValid);
// SreLength is too big
byte[] buffer = gre.ToArray();
buffer[buffer.Length - 1] = 200;
newIpPayload = new Datagram(buffer);
packetBuilder = new PacketBuilder(ethernetLayer, ipLayer, new PayloadLayer {
Data = newIpPayload
});
packet = packetBuilder.Build(DateTime.Now);
Assert.IsFalse(packet.IsValid);
// PayloadOffset is too big
buffer = gre.ToArray();
buffer[gre.Length - 10] = 100;
newIpPayload = new Datagram(buffer);
packetBuilder = new PacketBuilder(ethernetLayer, ipLayer, new PayloadLayer {
Data = newIpPayload
});
packet = packetBuilder.Build(DateTime.Now);
Assert.IsFalse(packet.IsValid);
// PayloadOffset isn't aligned to ip
buffer = gre.ToArray();
buffer[gre.Length - 10] = 3;
newIpPayload = new Datagram(buffer);
packetBuilder = new PacketBuilder(ethernetLayer, ipLayer, new PayloadLayer {
Data = newIpPayload
});
packet = packetBuilder.Build(DateTime.Now);
Assert.IsFalse(packet.IsValid);
// PayloadOffset isn't aligned to as
buffer = gre.ToArray();
buffer[gre.Length - 16] = 1;
newIpPayload = new Datagram(buffer);
packetBuilder = new PacketBuilder(ethernetLayer, ipLayer, new PayloadLayer {
Data = newIpPayload
});
packet = packetBuilder.Build(DateTime.Now);
Assert.IsFalse(packet.IsValid);
}
}
private static void CreateRandomIpPayload(Random random, Layer ipLayer, List <ILayer> layers)
{
IpV6Layer ipV6Layer = ipLayer as IpV6Layer;
if (ipV6Layer != null)
{
var headers = ipV6Layer.ExtensionHeaders.Headers;
if (headers.Any() && headers.Last().Protocol == IpV4Protocol.EncapsulatingSecurityPayload)
{
return;
}
}
if (ipV6Layer != null ? ipV6Layer.LastNextHeader != null : random.NextBool(20))
{
// Finish with payload.
PayloadLayer payloadLayer = random.NextPayloadLayer(random.Next(100));
layers.Add(payloadLayer);
return;
}
IpV4Layer ipV4Layer = ipLayer as IpV4Layer;
if (ipV4Layer != null)
{
ipV4Layer.Protocol = null;
if (random.NextBool())
{
ipV4Layer.Fragmentation = IpV4Fragmentation.None;
}
}
switch (random.Next(0, 11))
{
case 0: // IpV4.
case 1:
IpV4Layer innerIpV4Layer = random.NextIpV4Layer();
layers.Add(innerIpV4Layer);
CreateRandomIpPayload(random, innerIpV4Layer, layers);
return;
case 2: // IpV6.
case 3:
IpV6Layer innerIpV6Layer = random.NextIpV6Layer(random.NextBool(20));
layers.Add(innerIpV6Layer);
CreateRandomIpPayload(random, innerIpV6Layer, layers);
return;
case 4: // Igmp.
layers.Add(random.NextIgmpLayer());
return;
case 5: // Icmp.
IcmpLayer icmpLayer = random.NextIcmpLayer();
layers.Add(icmpLayer);
layers.AddRange(random.NextIcmpPayloadLayers(icmpLayer));
return;
case 6: // Gre.
GreLayer greLayer = random.NextGreLayer();
layers.Add(greLayer);
CreateRandomEthernetPayload(random, greLayer, layers);
return;
case 7: // Udp.
case 8:
UdpLayer udpLayer = random.NextUdpLayer();
layers.Add(udpLayer);
CreateRandomUdpPayload(random, udpLayer, layers);
return;
case 9: // Tcp.
case 10:
TcpLayer tcpLayer = random.NextTcpLayer();
layers.Add(tcpLayer);
CreateRandomTcpPayload(random, tcpLayer, layers);
return;
default:
throw new InvalidOperationException("Invalid value.");
}
}
/// <summary>
/// This function build an IPv4 over GRE over IPv4 over Ethernet packet.
/// </summary>
private static Packet BuildGrePacket()
{
EthernetLayer ethernetLayer =
new EthernetLayer
{
Source = new MacAddress("01:01:01:01:01:01"),
Destination = new MacAddress("02:02:02:02:02:02"),
EtherType = EthernetType.None, // Will be filled automatically.
};
IpV4Layer ipV4Layer =
new IpV4Layer
{
Source = new IpV4Address("1.2.3.4"),
CurrentDestination = new IpV4Address("11.22.33.44"),
Fragmentation = IpV4Fragmentation.None,
HeaderChecksum = null, // Will be filled automatically.
Identification = 123,
Options = IpV4Options.None,
Protocol = null, // Will be filled automatically.
Ttl = 100,
TypeOfService = 0,
};
GreLayer greLayer =
new GreLayer
{
Version = GreVersion.Gre,
ProtocolType = EthernetType.None, // Will be filled automatically.
RecursionControl = 0,
FutureUseBits = 0,
ChecksumPresent = true,
Checksum = null, // Will be filled automatically.
Key = null,
SequenceNumber = 123,
AcknowledgmentSequenceNumber = null,
RoutingOffset = null,
Routing = null,
StrictSourceRoute = false,
};
IpV4Layer innerIpV4Layer =
new IpV4Layer
{
Source = new IpV4Address("100.200.201.202"),
CurrentDestination = new IpV4Address("123.254.132.40"),
Fragmentation = IpV4Fragmentation.None,
HeaderChecksum = null, // Will be filled automatically.
Identification = 123,
Options = IpV4Options.None,
Protocol = IpV4Protocol.Udp,
Ttl = 120,
TypeOfService = 0,
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, greLayer, innerIpV4Layer);
return builder.Build(DateTime.Now);
}
