override public ForwardingDecision process_packet(int in_port, ref Packet packet)
{
#if DEBUG
Console.Write("!");
Console.Write("{0}({1}/{2}) ", in_port, Interlocked.Increment(ref count), PaxConfig_Lite.no_interfaces);
#endif
int[] target_ports = ForwardingDecision.broadcast_raw(in_port);
return(new ForwardingDecision.MultiPortForward(target_ports));
}
override public ForwardingDecision process_packet(int in_port, ref Packet packet)
{
int[] out_ports;
if (packet is PacketDotNet.EthernetPacket)
{
EthernetPacket eth = ((PacketDotNet.EthernetPacket)packet);
int lookup_out_port;
// Forwarding decision.
if (forwarding_table.TryGetValue(eth.DestinationHwAddress, out lookup_out_port))
{
if (lookup_out_port == in_port)
{
var tmp = Console.ForegroundColor;
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine("Interface {0} was about to emit a frame it has just received.", PaxConfig.deviceMap[in_port].Name);
Console.ForegroundColor = tmp;
out_ports = new int[0];
}
else
{
out_ports = new int[1] {
lookup_out_port
};
}
}
else
{
out_ports = ForwardingDecision.broadcast_raw(in_port);
}
// This might hold the value that's mapped to by eth.SourceHwAddress,
// if one exists in our forwarding_table.
int supposed_in_port;
// Switch learns which port knows about the SourceHwAddress.
if (forwarding_table.TryGetValue(eth.SourceHwAddress, out supposed_in_port))
{
if (supposed_in_port != in_port)
{
if (!forwarding_table.TryUpdate(eth.SourceHwAddress, in_port, supposed_in_port))
{
Console.WriteLine("Concurrent update of output port for " + eth.SourceHwAddress.ToString());
}
#if DEBUG
Debug.WriteLine("Relearned " + eth.SourceHwAddress.ToString() + " <- " + PaxConfig.deviceMap[in_port].Name);
#endif
}
}
else
{
if (!forwarding_table.TryUpdate(eth.SourceHwAddress, in_port, supposed_in_port))
{
Console.WriteLine("Concurrent update of output port for " + eth.SourceHwAddress.ToString());
}
#if DEBUG
Debug.WriteLine("Learned " + eth.SourceHwAddress.ToString() + " <- " + PaxConfig.deviceMap[in_port].Name);
#endif
}
// FIXME We don't have a "forgetting policy". We could periodically empty our forwarding_table.
}
else
{
// Drop if the packet's not an Ethernet frame.
out_ports = new int[0];
}
return(new ForwardingDecision.MultiPortForward(out_ports));
}
