public ForwardingDecision process_packet(int in_port, ref Packet packet)
{
ForwardingDecision fd = null;
//We return the ForwardingDecision made by the last element in the chain.
foreach (IPacketProcessor pp in chain)
{
fd = pp.process_packet(in_port, ref packet);
}
return(fd);
}
public void packetHandler(object sender, CaptureEventArgs e)
{
var packet = PacketDotNet.Packet.ParsePacket(e.Packet.LinkLayerType, e.Packet.Data);
int in_port = PaxConfig.rdeviceMap[e.Device.Name];
int out_port;
ForwardingDecision des = process_packet(in_port, ref packet);
if (des is ForwardingDecision.SinglePortForward)
{
out_port = ((ForwardingDecision.SinglePortForward)des).target_port;
}
else
{
throw (new Exception("Expected SinglePortForward"));
}
#if DEBUG
Debug.Write(PaxConfig.deviceMap[in_port].Name + " -1> ");
#endif
if (out_port > -1)
{
var device = PaxConfig.deviceMap[out_port];
if (packet is EthernetPacket)
{
((EthernetPacket)packet).SourceHwAddress = device.MacAddress;
}
device.SendPacket(packet);
#if DEBUG
Debug.WriteLine(PaxConfig.deviceMap[out_port].Name);
}
else
{
Debug.WriteLine("<dropped>");
#endif
}
}
public void packetHandler(object sender, CaptureEventArgs e)
{
var packet = PacketDotNet.Packet.ParsePacket(e.Packet.LinkLayerType, e.Packet.Data);
int in_port = PaxConfig.rdeviceMap[e.Device.Name];
int[] out_ports;
ForwardingDecision des = process_packet(in_port, ref packet);
if (des is ForwardingDecision.MultiPortForward)
{
out_ports = ((ForwardingDecision.MultiPortForward)des).target_ports;
/*
* Since MultiPortForward works with arrays, this increases the exposure
* to dud values:
* negative values within arrays
* repeated values within arrays
* an array might be larger than intended, and contains rubbish data.
* These could manifest themselves as bugs or abused behaviour.
* FIXME determine how each of these cases will be treated.
*/
}
else
{
throw (new Exception("Expected MultiPortForward"));
}
#if DEBUG
Debug.Write(PaxConfig.deviceMap[in_port].Name + " -> ");
// It's useful to know the width of the returned array during debugging,
// since it might be that the array was wider than intended, and contained
// repeated or rubbish values.
Debug.Write("[" + out_ports.Length.ToString() + "] ");
#endif
for (int idx = 0; idx < out_ports.Length; idx++)
{
int out_port = out_ports[idx];
// Check if trying to send over a non-existent port.
if (out_port < PaxConfig_Lite.no_interfaces)
{
PaxConfig.deviceMap[out_port].SendPacket(packet);
#if DEBUG
Debug.Write("(" + out_port.ToString() + ") "); // Show the network interface offset.
// And now show the network interface name that the offset resolves to.
if (idx < out_ports.Length - 1)
{
Debug.Write(PaxConfig.deviceMap[out_port].Name + ", ");
}
else
{
Debug.Write(PaxConfig.deviceMap[out_port].Name);
}
#endif
}
else if (!(out_port < PaxConfig_Lite.no_interfaces) &&
!PaxConfig_Lite.ignore_phantom_forwarding)
{
throw (new Exception("Tried forward to non-existant port"));
}
}
#if DEBUG
Debug.WriteLine("");
#endif
}
