package jos.system.net.jeps;

class UDP extends Protocol
{
  int MAXPORT=65534;
  int defport=30000;
  UDPQueue[] queues;
  
  UDP()
  {
    protocolNumber=0x11;
    queues=new UDPQueue[MAXPORT];
    next=null;
  }

  public void Handle(Packet p)
  {
    UDPPacket udpp = new UDPPacket(p);
    System.out.println(udpp.toString());
    if (queues[udpp.destport] != null)
     { queues[udpp.destport].add(udpp);}
    else {System.out.println("No listening socket on UDP port "+udpp.destport);}
    /* Should send ICMP: PORT UNREACH */
  }
  
  public UDPQueue openQueue(int port) throws Exception
  {
    int startport=defport;
    if (port == 0) 
     { port=defport; 
       defport=(defport%MAXPORT)+1;
       while(queues[port]!=null)
 	{ port=defport; 
          defport=(defport%MAXPORT)+1;
	  if (startport==defport) {throw new StackPanic("No more UDP ports");}
	}
     }
    if (queues[port] != null) {throw new java.lang.Exception("Port already in use");}
    queues[port]=new UDPQueue(port,UDPQueue.ANYPORT);
    System.out.println("opened port "+port);
    return queues[port];
  }
  
  public void send(IPAddr ipaddr,UDPPacket udpp) throws NoRouteException
  {
    IP.ip.send(ipaddr,udpp);
  }
};