mac.h

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/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */
/*
 * Copyright (c) 1997 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the Daedalus Research
 *      Group at the University of California Berkeley.
 * 4. Neither the name of the University nor of the Laboratory may be used
 *    to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Contributed by Giao Nguyen, http://daedalus.cs.berkeley.edu/~gnguyen
 *
 * @(#) $Header: /nfs/jade/vint/CVSROOT/ns-2/mac/mac.h,v 1.35 2000/12/20 10:11:36 alefiyah Exp $ (UCB)
 */

#ifndef ns_mac_h
#define ns_mac_h

#include <assert.h>
#include "bi-connector.h"
#include "packet.h"
#include "ip.h"
#include "route.h"
#include "ll.h"
#include "phy.h"
#include "marshall.h"
#include "channel.h"

class Channel;

#define ZERO    0.00000

/*
 * Medium Access Control (MAC)
 */

#define EF_COLLISION 2          // collision error flag

/* ======================================================================
   Defines / Macros used by all MACs.
   ====================================================================== */

#define ETHER_ADDR(x)   (GET4BYTE(x))

#define MAC_HDR_LEN     64

#define MAC_BROADCAST   ((u_int32_t) 0xffffffff)
#define BCAST_ADDR -1

#define ETHER_ADDR_LEN  6
#define ETHER_TYPE_LEN  2
#define ETHER_FCS_LEN   4

#define ETHERTYPE_IP    0x0800
#define ETHERTYPE_ARP   0x0806

enum MacState {
        MAC_IDLE        = 0x0000,
        MAC_POLLING     = 0x0001,
        MAC_RECV        = 0x0010,
        MAC_SEND        = 0x0100,
        MAC_RTS         = 0x0200,
        MAC_CTS         = 0x0400,
        MAC_ACK         = 0x0800,
        MAC_COLL        = 0x1000
};

enum MacFrameType {
        MF_BEACON       = 0x0008, // beaconing
        MF_CONTROL      = 0x0010, // used as mask for control frame
        MF_SLOTS        = 0x001a, // announce slots open for contention
        MF_RTS          = 0x001b, // request to send
        MF_CTS          = 0x001c, // clear to send, grant
        MF_ACK          = 0x001d, // acknowledgement
        MF_CF_END       = 0x001e, // contention free period end
        MF_POLL         = 0x001f, // polling
        MF_DATA         = 0x0020, // also used as mask for data frame
        MF_DATA_ACK     = 0x0021  // ack for data frames
};

struct hdr_mac {
        MacFrameType ftype_;    // frame type
        int macSA_;             // source MAC address
        int macDA_;             // destination MAC address
        u_int16_t hdr_type_;     // mac_hdr type

        double txtime_;         // transmission time
        double sstime_;         // slot start time

        int padding_;

        inline void set(MacFrameType ft, int sa, int da=-1) {
                ftype_ = ft;
                macSA_ = sa;
                if (da != -1)  macDA_ = da;
        }
        inline MacFrameType& ftype() { return ftype_; }
        inline int& macSA() { return macSA_; }
        inline int& macDA() { return macDA_; }
        inline u_int16_t& hdr_type() {return hdr_type_; }

        inline double& txtime() { return txtime_; }
        inline double& sstime() { return sstime_; }

        // Header access methods
        static int offset_;
        inline static int& offset() { return offset_; }
        inline static hdr_mac* access(const Packet* p) {
                return (hdr_mac*) p->access(offset_);
        }
};

/* ===================================================================
   Objects that want to promiscously listen to the packets before
   address filtering must inherit from class Tap in order to plug into
   the tap
   =================================================================*/

class Tap {
public:
        virtual void tap(const Packet *p) = 0;
        // tap is given all packets received by the host.
        // it must not alter or free the pkt.  If you want to frob it, copy it.
};


class MacHandlerResume : public Handler {
public:
        MacHandlerResume(Mac* m) : mac_(m) {}
        void handle(Event*);
protected:
        Mac* mac_;
};

class MacHandlerSend : public Handler {
public:
        MacHandlerSend(Mac* m) : mac_(m) {}
        void handle(Event*);
protected:
        Mac* mac_;
};


/* ==================================================================
   MAC data structure
   ================================================================*/

class Mac : public BiConnector {
public:
        Mac();
        virtual void recv(Packet* p, Handler* h);
        virtual void sendDown(Packet* p);
        virtual void sendUp(Packet *p);

        virtual void resume(Packet* p = 0);
        virtual void installTap(Tap *t) { tap_ = t; }
        
        inline double txtime(int bytes) {
                return (8. * bytes / bandwidth_);
        }
        inline double txtime(Packet* p) {
                return 8. * (MAC_HDR_LEN + \
                             (HDR_CMN(p))->size()) / bandwidth_;
        }
        inline double bandwidth() const { return bandwidth_; }
        
        inline int addr() { return index_; }
        inline MacState state() { return state_; }
        inline MacState state(int m) { return state_ = (MacState) m; }
        
        //mac methods to set dst, src and hdt_type in pkt hdrs.
        // note: -1 is the broadcast mac addr.
        virtual inline int hdr_dst(char* hdr, int dst = -2) {
                struct hdr_mac *dh = (struct hdr_mac*) hdr;
                if(dst > -2)
                        dh->macDA_ = dst;
                return dh->macDA();
        }
        virtual inline int hdr_src(char* hdr, int src = -2) {
                struct hdr_mac *dh = (struct hdr_mac*) hdr;
                if(src > -2)
                        dh->macSA_ = src;
                return dh->macSA();
        }
        virtual inline int hdr_type(char *hdr, u_int16_t type = 0) {
                struct hdr_mac *dh = (struct hdr_mac*) hdr;
                if (type)
                        dh->hdr_type_ = type;
                return dh->hdr_type();
        }

private:
        void mac_log(Packet *p) {
                logtarget_->recv(p, (Handler*) 0);
        }
        NsObject*       logtarget_;

protected:
        int command(int argc, const char*const* argv);
        virtual int initialized() { 
                return (netif_ && uptarget_ && downtarget_); 
        }
        int index_;             // MAC address
        double bandwidth_;      // channel bitrate
        double delay_;          // MAC overhead
        int abstract_;         //   MAC support for abstract LAN 
        
        Phy *netif_;            // network interface
        Tap *tap_;              // tap agent
        LL *ll_;                // LL this MAC is connected to
        Channel *channel_;      // channel this MAC is connected to

        Handler* callback_;     // callback for end-of-transmission
        MacHandlerResume hRes_; // resume handler
        MacHandlerSend hSend_;  // handle delay send due to busy channel
        Event intr_;

        /*
         * Internal MAC State
         */
        MacState state_;        // MAC's current state
        Packet *pktRx_;
        Packet *pktTx_;
};

#endif

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