text: #ifndef CLICK_MARKIPCE_HH
  #define CLICK_MARKIPCE_HH
  #include <click/element.hh>
  #include <click/atomic.hh>
  CLICK_DECLS
  
  /*
  =c
  
  MarkIPCE([FORCE])
  
  =s ip
  
  sets IP packets' ECN field to Congestion Experienced
  
  =d
  
  Expects IP packets as input.  Sets each incoming packet's ECN field to
  Congestion Experienced (value 3), incrementally recalculates the IP checksum,
  and passes the packet to output 0.  Packets whose ECN field is zero (not
  ECN-capable) are dropped unless the optional FORCE argument is true. */
  
  class MarkIPCE : public Element { public:
  
      MarkIPCE();
      ~MarkIPCE();
  
      const char *class_name() const		{ return "MarkIPCE"; }
      const char *port_count() const		{ return PORTS_1_1; }
  
      int configure(Vector<String> &conf, ErrorHandler *errh);
      void add_handlers();
  
      Packet *simple_action(Packet *);
  
    private:
  
      bool _force;
      atomic_uint32_t _drops;
  
  };
  
  CLICK_ENDDECLS
  #endif
  