public void IpV4Handler(Packet packet, IList <Packet> packetList = null)
{
if (packet.Ethernet.IpV4.Length > MTU)
{
EthernetLayer ethernetLayer = new EthernetLayer
{
Source = ownHardwareAddress,
Destination = packet.Ethernet.Source,
EtherType = EthernetType.None,
};
IpV4Layer ipV4Layer = new IpV4Layer
{
Source = packet.Ethernet.IpV4.Destination,
CurrentDestination = packet.Ethernet.IpV4.Source,
Fragmentation = packet.Ethernet.IpV4.Fragmentation,
HeaderChecksum = null, // Will be filled automatically.
Identification = 123,
Options = packet.Ethernet.IpV4.Options,
Protocol = packet.Ethernet.IpV4.Protocol,
Ttl = packet.Ethernet.IpV4.Ttl,
TypeOfService = packet.Ethernet.IpV4.TypeOfService,
};
IcmpDestinationUnreachableLayer icmpLayer = new IcmpDestinationUnreachableLayer
{
Code = IcmpCodeDestinationUnreachable.FragmentationNeededAndDoNotFragmentSet,
NextHopMaximumTransmissionUnit = (ushort)MTU,
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, icmpLayer);
SendPacket(builder.Build(DateTime.Now));
// TODO: fix warning spam
if (Global.Config.LoadBalancer.ShowTrayTipsWarnings)
{
Global.ShowTrayTip("Load Balancer", "IP packet larger than the MTU detected on " + Name + ".\n\nIP fragmentation is not supported.", ToolTipIcon.Warning);
}
Global.WriteLog("Load Balancer: IP packet larger than the MTU detected on " + Name);
return;
}
if (packet.Ethernet.IpV4.Ttl < 2)
{
EthernetLayer ethernetLayer = new EthernetLayer
{
Source = ownHardwareAddress,
Destination = packet.Ethernet.Source,
EtherType = EthernetType.None,
};
IpV4Layer ipV4Layer = new IpV4Layer
{
Source = ownProtocolAddress,
CurrentDestination = packet.Ethernet.IpV4.Source,
Fragmentation = packet.Ethernet.IpV4.Fragmentation,
HeaderChecksum = null, // Will be filled automatically.
Identification = 123,
Options = packet.Ethernet.IpV4.Options,
Protocol = packet.Ethernet.IpV4.Protocol,
Ttl = packet.Ethernet.IpV4.Ttl,
TypeOfService = packet.Ethernet.IpV4.TypeOfService,
};
IcmpTimeExceededLayer icmpLayer = new IcmpTimeExceededLayer
{
Code = 0,
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, icmpLayer, packet.Ethernet.IpV4.ExtractLayer(), packet.Ethernet.IpV4.Payload.ExtractLayer());
SendPacket(builder.Build(DateTime.Now));
return;
}
if (packet.Ethernet.IpV4.Protocol == IpV4Protocol.InternetControlMessageProtocol)
{
if (packet.Ethernet.IpV4.Destination == ownProtocolAddress)
{
if ((packet.Ethernet.IpV4.Icmp.MessageType == IcmpMessageType.Echo || packet.Ethernet.IpV4.Fragmentation.Offset > 0))
{
EthernetLayer ethernetLayer = new EthernetLayer
{
Source = ownHardwareAddress,
Destination = packet.Ethernet.Source,
EtherType = EthernetType.None,
};
IpV4Layer ipV4Layer = new IpV4Layer
{
Source = packet.Ethernet.IpV4.Destination,
CurrentDestination = packet.Ethernet.IpV4.Source,
Fragmentation = packet.Ethernet.IpV4.Fragmentation,
HeaderChecksum = null, // Will be filled automatically.
Identification = 123,
Options = packet.Ethernet.IpV4.Options,
Protocol = packet.Ethernet.IpV4.Protocol,
Ttl = packet.Ethernet.IpV4.Ttl,
TypeOfService = packet.Ethernet.IpV4.TypeOfService,
};
if (packet.Ethernet.IpV4.Fragmentation.Options == IpV4FragmentationOptions.DoNotFragment ||
packet.Ethernet.IpV4.Fragmentation.Options == IpV4FragmentationOptions.None && packet.Ethernet.IpV4.Fragmentation.Offset == 0)
{
byte[] icmpPacket = packet.Ethernet.IpV4.Payload.ToArray();
icmpPacket[0] = 0;
icmpPacket[2] = 0;
icmpPacket[3] = 0;
ushort checksum = IpFunctions.ComputeIpChecksum(icmpPacket);
icmpPacket[2] = (byte)(checksum >> 8);
icmpPacket[3] = (byte)(checksum & 0xff);
PayloadLayer payloadLayer = new PayloadLayer
{
Data = new Datagram(icmpPacket),
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, payloadLayer);
SendPacket(builder.Build(DateTime.Now));
}
else if (packet.Ethernet.IpV4.Fragmentation.Offset == 0 && packet.Ethernet.IpV4.Fragmentation.Options == IpV4FragmentationOptions.MoreFragments)
{
byte[] icmpHeader = packet.Ethernet.IpV4.Payload.ToArray();
icmpHeader[0] = 0;
icmpHeader[2] = 0;
icmpHeader[3] = 0;
int icmpPacketLength = icmpHeader.Length;
for (int i = 1; i < packetList.Count; i++)
{
icmpPacketLength += packetList[i].Ethernet.IpV4.Payload.ToArray().Length;
}
byte[] icmpPacket = new byte[icmpPacketLength];
Buffer.BlockCopy(icmpHeader, 0, icmpPacket, 0, icmpHeader.Length);
icmpPacketLength = icmpHeader.Length;
for (int i = 1; i < packetList.Count; i++)
{
Buffer.BlockCopy(packetList[i].Ethernet.IpV4.Payload.ToArray(), 0, icmpPacket, icmpPacketLength, packetList[i].Ethernet.IpV4.Payload.ToArray().Length);
icmpPacketLength += packetList[i].Ethernet.IpV4.Payload.ToArray().Length;
}
ushort checksum = IpFunctions.ComputeIpChecksum(icmpPacket);
icmpHeader[2] = (byte)(checksum >> 8);
icmpHeader[3] = (byte)(checksum & 0xff);
PayloadLayer payloadLayer = new PayloadLayer
{
Data = new Datagram(icmpHeader),
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, payloadLayer);
SendPacket(builder.Build(DateTime.Now));
}
else
{
PayloadLayer payloadLayer = new PayloadLayer
{
Data = new Datagram(packet.Ethernet.IpV4.Payload.ToArray()),
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, payloadLayer);
SendPacket(builder.Build(DateTime.Now));
}
}
}
else if (packet.Ethernet.IpV4.Source == ifProtocolAddress)
{
if ((packet.Ethernet.IpV4.Icmp.MessageType == IcmpMessageType.Echo || packet.Ethernet.IpV4.Fragmentation.Offset > 0))
{
{
tapRoutingObject = RoutingTable.GetInterface(packet);
if (tapRoutingObject.response == -1)
{
return;
}
EthernetLayer ethernetLayer = new EthernetLayer
{
Source = physicalWorkers[tapRoutingObject.ifIndex].ifHardwareAddress,
Destination = physicalWorkers[tapRoutingObject.ifIndex].gatewayHardwareAddress,
EtherType = EthernetType.None,
};
IpV4Layer ipV4Layer = new IpV4Layer
{
Source = physicalWorkers[tapRoutingObject.ifIndex].ifProtocolAddress,
CurrentDestination = packet.Ethernet.IpV4.Destination,
Fragmentation = packet.Ethernet.IpV4.Fragmentation,
HeaderChecksum = null, // Will be filled automatically.
Identification = packet.Ethernet.IpV4.Identification,
Options = packet.Ethernet.IpV4.Options,
Protocol = packet.Ethernet.IpV4.Protocol,
Ttl = (byte)(packet.Ethernet.IpV4.Ttl - 1),
TypeOfService = packet.Ethernet.IpV4.TypeOfService,
};
PayloadLayer payloadLayer = new PayloadLayer
{
Data = new Datagram(packet.Ethernet.IpV4.Payload.ToArray()),
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, payloadLayer);
physicalWorkers[tapRoutingObject.ifIndex].SendPacket(builder.Build(DateTime.Now));
}
}
}
}
else if (packet.Ethernet.IpV4.Protocol == IpV4Protocol.Tcp)
{
if (packet.Ethernet.IpV4.Source == ifProtocolAddress)
{
tapRoutingObject = RoutingTable.GetInterface(packet);
if (tapRoutingObject.response == -1)
{
return;
}
if (tapRoutingObject.response == -3)
{
lock (RoutingTable.connParams[tapRoutingObject.guid])
SendAck(tapRoutingObject.guid);
return;
}
lock (RoutingTable.connParams[tapRoutingObject.guid])
{
RoutingTable.connParams[tapRoutingObject.guid].freeWindow = (int)((packet.Ethernet.IpV4.Tcp.Window << RoutingTable.connParams[tapRoutingObject.guid].windowScale) - (RoutingTable.connParams[tapRoutingObject.guid].seq - packet.Ethernet.IpV4.Tcp.AcknowledgmentNumber));
if (RoutingTable.connParams[tapRoutingObject.guid].windowFull)
{
if (RoutingTable.connParams[tapRoutingObject.guid].freeWindow > RoutingTable.connParams[tapRoutingObject.guid].bytesReceived)
{
SendData(tapRoutingObject.guid, RoutingTable.connParams[tapRoutingObject.guid].bytesReceived);
RoutingTable.connParams[tapRoutingObject.guid].freeWindow -= RoutingTable.connParams[tapRoutingObject.guid].bytesReceived;
RoutingTable.connParams[tapRoutingObject.guid].windowFull = false;
RoutingTable.connParams[tapRoutingObject.guid].UpdateSeq(RoutingTable.connParams[tapRoutingObject.guid].bytesReceived);
try
{
RoutingTable.connParams[tapRoutingObject.guid].socket.BeginReceive(RoutingTable.connParams[tapRoutingObject.guid].receivingBuffer, 0, RoutingTable.connParams[tapRoutingObject.guid].receivingBuffer.Count(), 0, new AsyncCallback(physicalWorkers[tapRoutingObject.ifIndex].ReceiveCallback), tapRoutingObject.guid);
}
catch (Exception)
{
RoutingTable.RequestAccess();
if (!RoutingTable.connStatus[tapRoutingObject.guid].remoteEPFin)
{
tapWorker.SendRst(tapRoutingObject.guid);
}
RoutingTable.connStatus[tapRoutingObject.guid].remoteEPFin = true;
RoutingTable.connStatus[tapRoutingObject.guid].localEPFin = true;
RoutingTable.ReleaseAccess();
}
}
}
}
if (packet.Ethernet.IpV4.Tcp.PayloadLength > 0 || tapRoutingObject.response == -2)
{
physicalWorkers[tapRoutingObject.ifIndex].SendData(packet, tapRoutingObject.guid);
}
}
}
else if (packet.Ethernet.IpV4.Protocol == IpV4Protocol.Udp)
{
if (packet.Ethernet.IpV4.Source == ifProtocolAddress)
{
tapRoutingObject = RoutingTable.GetInterface(packet);
if (tapRoutingObject.response == -1)
{
return;
}
EthernetLayer ethernetLayer = new EthernetLayer
{
Source = physicalWorkers[tapRoutingObject.ifIndex].ifHardwareAddress,
Destination = physicalWorkers[tapRoutingObject.ifIndex].gatewayHardwareAddress,
EtherType = packet.Ethernet.EtherType,
};
IpV4Layer ipV4Layer = new IpV4Layer
{
Source = physicalWorkers[tapRoutingObject.ifIndex].ifProtocolAddress,
CurrentDestination = packet.Ethernet.IpV4.Destination,
Fragmentation = packet.Ethernet.IpV4.Fragmentation,
HeaderChecksum = null, // Will be filled automatically.
Identification = packet.Ethernet.IpV4.Identification,
Options = packet.Ethernet.IpV4.Options,
Protocol = packet.Ethernet.IpV4.Protocol,
Ttl = (byte)(packet.Ethernet.IpV4.Ttl - 1),
TypeOfService = packet.Ethernet.IpV4.TypeOfService,
};
UdpLayer udpLayer = new UdpLayer
{
SourcePort = packet.Ethernet.IpV4.Udp.SourcePort,
DestinationPort = packet.Ethernet.IpV4.Udp.DestinationPort,
Checksum = null, // Will be filled automatically.
CalculateChecksumValue = packet.Ethernet.IpV4.Udp.IsChecksumOptional,
};
PayloadLayer payloadLayer = new PayloadLayer
{
Data = new Datagram(packet.Ethernet.IpV4.Udp.Payload.ToArray()),
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, udpLayer, payloadLayer);
physicalWorkers[tapRoutingObject.ifIndex].SendPacket(builder.Build(DateTime.Now));
}
}
}