mac-802_3.h

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#ifndef __mac_802_3_h__
#define __mac_802_3_h__

#include <assert.h>
#include "mac.h"

#define min(x, y)   ((x) < (y) ? (x) : (y))
#define ETHER_HDR_LEN       ((ETHER_ADDR_LEN << 1) + ETHER_TYPE_LEN)

/*
 10Mbps:
#define IEEE_8023_SLOT      0.000051200 // 512 bit times
#define IEEE_8023_IFS       0.000009600 // 9.6us interframe spacing
 100Mbps:
#define IEEE_8023_SLOT                0.0000051200    //512 bit time
#define IEEE_8023_IFS                 0.0000009600    //0.96us interframe spacing
*/
#define IEEE_8023_SLOT_BITS             512.0 //when we divide these by the bandwidth
#define IEEE_8023_IFS_BITS               96.0 //we'll have what we want

#define IEEE_8023_ALIMIT    16      // attempt limit
#define IEEE_8023_BLIMIT    10      // backoff limit
#define IEEE_8023_JAMSIZE   32      // bits
#define IEEE_8023_MAXFRAME  1518        // bytes
#define IEEE_8023_MINFRAME  64      // bytes
#define INVALID_UID             -1              // Used for mac level traces
#define INVALID_TIME            -1

/* ======================================================================
   Handler Functions
   ====================================================================== */
class Mac802_3;

class MacHandler : public Handler {
public:
    MacHandler(Mac802_3* m) :  callback(0), mac(m), busy_(false) {}
    virtual void handle(Event *e) = 0;
    virtual inline void cancel();
    bool busy(void) { return busy_; }
    double expire(void) { return intr.time_; }
protected:
    Handler     *callback;
    Mac802_3    *mac;
    Event       intr;
    bool        busy_;
};


class Mac8023HandlerSend : public MacHandler {
 public:
    Mac8023HandlerSend(Mac802_3* m) : MacHandler(m), p_(0) {}
    void handle(Event*);
    void schedule(const Packet *p, double t);
    void cancel();
    const Packet *packet() const { return p_; }
 protected:
    const Packet *p_;
};

class MacHandlerRecv : public MacHandler {
public:
    MacHandlerRecv(Mac802_3* m) : MacHandler(m), p_(0) {}
    void handle(Event*);
    void schedule(Packet *p, double t);
    virtual void cancel();
private:
    Packet *p_;
};

class MacHandlerRetx : public MacHandler {
 public:
    MacHandlerRetx(Mac802_3* m) : MacHandler(m), p_(0), try_(1) {}
    void reset() {
        // before calling reset, you MUST free or drop p_
        if (busy_) cancel();
        try_= 1;
        p_= 0;
    }
    void handle(Event*);
    bool schedule(double delta=0.0);
    void cancel();
    void free() { 
        if (p_) {
            Packet::free(p_);
            p_= 0;
        }
    }
    Packet* packet() const { return p_; }
    void packet(Packet *p) { p_= p; }
private:
    Packet *p_;
    int try_;
};
        
class MacHandlerIFS : public MacHandler {
 public:
    MacHandlerIFS(Mac802_3* m) : MacHandler(m) {}
    void handle (Event*); 
    void schedule(double t);
    void cancel();
};


/* ======================================================================
   MAC data structure
   ====================================================================== */
class Mac802_3 : public Mac {
    friend class MacHandler;
    friend class MacHandlerRecv;
    friend class Mac8023HandlerSend;
    friend class MacHandlerRetx;
    friend class MacHandlerIFS;
 public:
    Mac802_3();

    void recv(Packet* p, Handler* h) {
        BiConnector::recv(p, h);
    }

 protected:
    void sendDown(Packet* p, Handler* h);
    void sendUp(Packet* p, Handler* h);
    /*
    inline int  hdr_dst(char* hdr, u_int32_t dst = -2);
    inline int  hdr_src(char* hdr, u_int32_t src = -2);
    inline int  hdr_type(char* hdr, u_int16_t type = 0);
    */
    
    void        recv_complete(Packet *p);
    virtual void    resume();

    //protected:
    virtual void    transmit(Packet* p);
    int trace_;      // To turn on MAC level collision traces 
private:
    //void      send(Packet *p, Handler *h);
    void        collision(Packet *p);

    //int       pktTxcnt;

    MacHandlerRecv  mhRecv_;
    MacHandlerRetx  mhRetx_;
    MacHandlerIFS   mhIFS_;
    Mac8023HandlerSend  mhSend_;
    
};


#endif /* __mac_802_3_h__ */

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