| public static SubM32 ( uint a, uint b, uint c ) : uint | ||
| a | uint | |
| b | uint | |
| c | uint | |
| return | uint | |
public void SendKeepAlive(Guid guid)
{
EthernetLayer ethernetLayer = new EthernetLayer
{
Source = ownHardwareAddress,
Destination = ifHardwareAddress,
EtherType = EthernetType.None,
};
IpV4Layer ipV4Layer = new IpV4Layer
{
Source = RoutingTable.connParams[guid].remoteIp,
CurrentDestination = ifProtocolAddress,
Fragmentation = IpV4Fragmentation.None,
HeaderChecksum = null, // Will be filled automatically.
Identification = ipID,
Options = IpV4Options.None,
Protocol = IpV4Protocol.Tcp,
Ttl = 128,
TypeOfService = 0,
};
TcpLayer tcpLayer = new TcpLayer
{
SourcePort = RoutingTable.connParams[guid].remotePort,
DestinationPort = RoutingTable.connParams[guid].localPort,
Checksum = null, // Will be filled automatically.
SequenceNumber = IpFunctions.SubM32(RoutingTable.connParams[guid].seq, 1),
AcknowledgmentNumber = RoutingTable.connParams[guid].ack,
ControlBits = TcpControlBits.Acknowledgment,
Window = RoutingTable.connParams[guid].GetWindow(),
UrgentPointer = 0,
Options = TcpOptions.None,
};
PacketBuilder builder = new PacketBuilder(ethernetLayer, ipV4Layer, tcpLayer);
SendPacket(builder.Build(DateTime.Now));
}
public static RoutingObject GetInterface(Packet packet)
{
RequestAccess();
RoutingObject routingObject = new RoutingObject();
if (packet.Ethernet.IpV4.Protocol == IpV4Protocol.Tcp)
{
ConnId connId = new ConnId(packet.Ethernet.IpV4.Tcp.SourcePort, packet.Ethernet.IpV4.Destination, packet.Ethernet.IpV4.Tcp.DestinationPort, IpV4Protocol.Tcp);
Guid guid;
if (guidList.TryGetValue(connId, out guid))
{
connStatus[guid].timeStamp = DateTime.Now;
routingObject.response = 0;
routingObject.ifIndex = routingTable[guid];
routingObject.guid = guid;
if ((packet.Ethernet.IpV4.Tcp.ControlBits & TcpControlBits.Reset) > 0)
{
connStatus[guid].localEPFin = true;
connStatus[guid].remoteEPFin = true;
routingObject.response = -1;
lock (connParams[guid])
{
connParams[guid].socket.Close();
}
}
else if ((packet.Ethernet.IpV4.Tcp.ControlBits & TcpControlBits.Fin) > 0)
{
routingObject.response = -2;
}
if (!connStatus[guid].localEPFin && packet.Ethernet.IpV4.Tcp.SequenceNumber == connStatus[guid].expectedSeq)
{
connStatus[guid].UpdateExpectedSeq(packet);
if (connStatus[guid].state == 2)
{
connStatus[guid].state = 3;
}
}
else if (packet.Ethernet.IpV4.Tcp.SequenceNumber == IpFunctions.SubM32(connStatus[guid].expectedSeq, 1) &&
(packet.Ethernet.IpV4.Tcp.ControlBits & (TcpControlBits.Fin | TcpControlBits.Synchronize)) == 0 &&
(packet.Ethernet.IpV4.Tcp.PayloadLength == 0 || packet.Ethernet.IpV4.Tcp.PayloadLength == 1) &&
!connStatus[guid].remoteEPFin)
{
routingObject.response = -3; // KeepAlive
}
else
{
routingObject.response = -1;
}
}
else
{
if ((packet.Ethernet.IpV4.Tcp.ControlBits & TcpControlBits.Synchronize) == TcpControlBits.Synchronize)
{
guid = Guid.NewGuid();
guidList.TryAdd(connId, guid);
int routingInterface = LoadBalancer.routingInterface;
routingTable.TryAdd(guid, routingInterface);
connParams.TryAdd(guid, new ConnParams());
connParams[guid].ack = packet.Ethernet.IpV4.Tcp.SequenceNumber;
connParams[guid].UpdateAck(1);
connParams[guid].localPort = packet.Ethernet.IpV4.Tcp.SourcePort;
connParams[guid].remoteIp = packet.Ethernet.IpV4.Destination;
connParams[guid].remotePort = packet.Ethernet.IpV4.Tcp.DestinationPort;
connStatus.TryAdd(guid, new ConnStatus());
connStatus[guid].timeStamp = DateTime.Now;
connStatus[guid].expectedSeq = packet.Ethernet.IpV4.Tcp.SequenceNumber;
connStatus[guid].UpdateExpectedSeq(packet);
connStatus[guid].state = 1;
foreach (TcpOption tcpOption in packet.Ethernet.IpV4.Tcp.Options.OptionsCollection)
{
if (tcpOption.OptionType == TcpOptionType.WindowScale)
{
connParams[guid].windowScale = ((TcpOptionWindowScale)tcpOption).ScaleFactorLog;
}
}
connParams[guid].windowSize = packet.Ethernet.IpV4.Tcp.Window;
connParams[guid].freeWindow = (int)((packet.Ethernet.IpV4.Tcp.Window << RoutingTable.connParams[guid].windowScale) - (RoutingTable.connParams[guid].seq - packet.Ethernet.IpV4.Tcp.AcknowledgmentNumber));
connParams[guid].socket = new Socket(System.Net.Sockets.AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
connParams[guid].socket.Bind(new IPEndPoint(new System.Net.IPAddress(physicalWorkers[routingInterface].ifProtocolAddressByte), 0));
connParams[guid].socket.BeginConnect(new IPEndPoint(new IPAddress(packet.Ethernet.IpV4.Destination.ToString().Split('.').Select(byte.Parse).ToArray()), (int)packet.Ethernet.IpV4.Tcp.DestinationPort), new AsyncCallback(physicalWorkers[routingInterface].ConnectCallback), guid);
}
catch (Exception)
{
connStatus[guid].localEPFin = true;
connStatus[guid].remoteEPFin = true;
}
}
routingObject.response = -1;
}
}
else if (packet.Ethernet.IpV4.Protocol == IpV4Protocol.Udp)
{
ConnId connId = new ConnId(packet.Ethernet.IpV4.Udp.SourcePort, packet.Ethernet.IpV4.Destination, packet.Ethernet.IpV4.Udp.DestinationPort, IpV4Protocol.Udp);
Guid guid;
if (guidList.TryGetValue(connId, out guid))
{
connStatus[guid].timeStamp = DateTime.Now;
routingObject.ifIndex = routingTable[guid];
routingObject.guid = guid;
}
else
{
guid = Guid.NewGuid();
guidList.TryAdd(connId, guid);
int routingInterface = LoadBalancer.routingInterface;
routingTable.TryAdd(guid, routingInterface);
connStatus.TryAdd(guid, new ConnStatus());
connStatus[guid].timeStamp = DateTime.Now;
routingObject.ifIndex = routingInterface;
routingObject.guid = guid;
}
}
else if (packet.Ethernet.IpV4.Protocol == IpV4Protocol.InternetControlMessageProtocol)
{
routingObject = new RoutingObject(0, LoadBalancer.routingInterface);
}
else
{
routingObject = new RoutingObject(-1, 0);
}
ReleaseAccess();
return(routingObject);
}