mac-802_11.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 Computer Systems
 *      Engineering Group at Lawrence Berkeley Laboratory.
 * 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.
 *
 * $Header: /nfs/jade/vint/CVSROOT/ns-2/mac/mac-802_11.h,v 1.20 2002/03/14 01:12:53 haldar Exp $
 *
 * Ported from CMU/Monarch's code, nov'98 -Padma.
 * wireless-mac-802_11.h
 */

#ifndef ns_mac_80211_h
#define ns_mac_80211_h

#include "mac-timers.h"
#include "marshall.h"

#define GET_ETHER_TYPE(x)               GET2BYTE((x))
#define SET_ETHER_TYPE(x,y)            {u_int16_t t = (y); STORE2BYTE(x,&t);}

/* ======================================================================
   Frame Formats
   ====================================================================== */

#define MAC_ProtocolVersion     0x00

#define MAC_Type_Management     0x00
#define MAC_Type_Control        0x01
#define MAC_Type_Data           0x02
#define MAC_Type_Reserved       0x03

#define MAC_Subtype_RTS         0x0B
#define MAC_Subtype_CTS         0x0C
#define MAC_Subtype_ACK         0x0D
#define MAC_Subtype_Data        0x00

struct frame_control {
        u_char          fc_subtype              : 4;
        u_char          fc_type                 : 2;
        u_char          fc_protocol_version     : 2;

        u_char          fc_order                : 1;
        u_char          fc_wep                  : 1;
        u_char          fc_more_data            : 1;
        u_char          fc_pwr_mgt              : 1;
        u_char          fc_retry                : 1;
        u_char          fc_more_frag            : 1;
        u_char          fc_from_ds              : 1;
        u_char          fc_to_ds                : 1;
};

struct rts_frame {
        struct frame_control    rf_fc;
        u_int16_t               rf_duration;
        u_char                  rf_ra[ETHER_ADDR_LEN];
        u_char                  rf_ta[ETHER_ADDR_LEN];
        u_char                  rf_fcs[ETHER_FCS_LEN];
};

struct cts_frame {
        struct frame_control    cf_fc;
        u_int16_t               cf_duration;
        u_char                  cf_ra[ETHER_ADDR_LEN];
        u_char                  cf_fcs[ETHER_FCS_LEN];
};

struct ack_frame {
        struct frame_control    af_fc;
        u_int16_t               af_duration;
        u_char                  af_ra[ETHER_ADDR_LEN];
        u_char                  af_fcs[ETHER_FCS_LEN];
};

// XXX This header does not have its header access function because it shares
// the same header space with hdr_mac.
struct hdr_mac802_11 {
        struct frame_control    dh_fc;
        u_int16_t               dh_duration;
        u_char                  dh_da[ETHER_ADDR_LEN];
        u_char                  dh_sa[ETHER_ADDR_LEN];
        u_char                  dh_bssid[ETHER_ADDR_LEN];
        u_int16_t               dh_scontrol;
        u_char                  dh_body[0]; // XXX Non-ANSI
};


/* ======================================================================
   Definitions
   ====================================================================== */

#define PLCP_HDR_LEN                            \
        ((phymib_->PreambleLength >> 3) +        \
         (phymib_->PLCPHeaderLength >> 3))

#define ETHER_HDR_LEN11                         \
        (PLCP_HDR_LEN +                         \
         sizeof(struct hdr_mac802_11) +         \
         ETHER_FCS_LEN)

#define ETHER_RTS_LEN                           \
        (PLCP_HDR_LEN +                         \
         sizeof(struct rts_frame))

#define ETHER_CTS_LEN                           \
         (PLCP_HDR_LEN +                        \
         sizeof(struct cts_frame))

#define ETHER_ACK_LEN                           \
         (PLCP_HDR_LEN +                        \
         sizeof(struct ack_frame))

/*
 * IEEE 802.11 Spec, section 15.3.2
 *      - default values for the DSSS PHY MIB
 */
#define DSSS_CWMin                      31
#define DSSS_CWMax                      1023
#define DSSS_SlotTime                   0.000020        // 20us
#define DSSS_CCATime                    0.000015        // 15us
#define DSSS_RxTxTurnaroundTime         0.000005        // 5us
#define DSSS_SIFSTime                   0.000010        // 10us
#define DSSS_PreambleLength             144             // 144 bits
#define DSSS_PLCPHeaderLength           48              // 48 bits
#define DSSS_PLCPDataRate               1.0e6           // 1Mbps

/* Must account for propagation delays added by the channel model when
 * calculating tx timeouts (as set in tcl/lan/ns-mac.tcl).
 *   -- Gavin Holland, March 2002
 */
#define DSSS_MaxPropagationDelay        0.000002        // 2us   XXXX

class PHY_MIB {
public:
        u_int32_t       CWMin;
        u_int32_t       CWMax;
        double          SlotTime;
        double          CCATime;
        double          RxTxTurnaroundTime;
        double          SIFSTime;
        u_int32_t       PreambleLength;
        u_int32_t       PLCPHeaderLength;
        double          PLCPDataRate;
};


/*
 * IEEE 802.11 Spec, section 11.4.4.2
 *      - default values for the MAC Attributes
 */
//#define MAC_RTSThreshold              3000            // bytes
#define MAC_RTSThreshold                0               // bytes
#define MAC_ShortRetryLimit             7               // retransmittions
#define MAC_LongRetryLimit              4               // retransmissions
#define MAC_FragmentationThreshold      2346            // bytes
#define MAC_MaxTransmitMSDULifetime     512             // time units
#define MAC_MaxReceiveLifetime          512             // time units

class MAC_MIB {
public:
        //              MACAddress;
        //              GroupAddresses;
        u_int32_t       RTSThreshold;
        u_int32_t       ShortRetryLimit;
        u_int32_t       LongRetryLimit;
        u_int32_t       FragmentationThreshold;
        u_int32_t       MaxTransmitMSDULifetime;
        u_int32_t       MaxReceiveLifetime;
        //              ManufacturerID;
        //              ProductID;

        u_int32_t       TransmittedFragmentCount;
        u_int32_t       MulticastTransmittedFrameCount;
        u_int32_t       FailedCount;    
        u_int32_t       RetryCount;
        u_int32_t       MultipleRetryCount;
        u_int32_t       FrameDuplicateCount;
        u_int32_t       RTSSuccessCount;
        u_int32_t       RTSFailureCount;
        u_int32_t       ACKFailureCount;
        u_int32_t       ReceivedFragmentCount;
        u_int32_t       MulticastReceivedFrameCount;
        u_int32_t       FCSErrorCount;
};


/* ======================================================================
   The following destination class is used for duplicate detection.
   ====================================================================== */
class Host {
public:
        LIST_ENTRY(Host) link;
        u_int32_t       index;
        u_int32_t       seqno;
};


/* ======================================================================
   The actual 802.11 MAC class.
   ====================================================================== */
class Mac802_11 : public Mac {
        friend class DeferTimer;
        friend class BackoffTimer;
        friend class IFTimer;
        friend class NavTimer;
        friend class RxTimer;
        friend class TxTimer;
public:
        Mac802_11(PHY_MIB* p, MAC_MIB *m);
        void            recv(Packet *p, Handler *h);
        inline int      hdr_dst(char* hdr, int dst = -2);
        inline int      hdr_src(char* hdr, int src = -2);
        inline int      hdr_type(char* hdr, u_int16_t type = 0);

protected:
        void    backoffHandler(void);
        void    deferHandler(void);
        void    navHandler(void);
        void    recvHandler(void);
        void    sendHandler(void);
        void    txHandler(void);

private:
        int             command(int argc, const char*const* argv);

        /*
         * Called by the timers.
         */
        void            recv_timer(void);
        void            send_timer(void);
        int             check_pktCTRL();
        int             check_pktRTS();
        int             check_pktTx();

        /*
         * Packet Transmission Functions.
         */
        void    send(Packet *p, Handler *h);
        void    sendRTS(int dst);
        void    sendCTS(int dst, double duration);
        void    sendACK(int dst);
        void    sendDATA(Packet *p);
        void    RetransmitRTS();
        void    RetransmitDATA();

        /*
         * Packet Reception Functions.
         */
        void    recvRTS(Packet *p);
        void    recvCTS(Packet *p);
        void    recvACK(Packet *p);
        void    recvDATA(Packet *p);

        void            capture(Packet *p);
        void            collision(Packet *p);
        void            discard(Packet *p, const char* why);
        void            rx_resume(void);
        void            tx_resume(void);

        inline int      is_idle(void);

        /*
         * Debugging Functions.
         */
        void            trace_pkt(Packet *p);
        void            dump(char* fname);

        inline int initialized() {
                return (phymib_ && macmib_ && cache_ && logtarget_ && 
                        Mac::initialized());
        }
        void mac_log(Packet *p) {
                logtarget_->recv(p, (Handler*) 0);
        }
        double txtime(Packet *p);
        double txtime(double psz, double drt);
        double txtime(int bytes) { /* clobber inherited txtime() */ abort(); }

        inline void inc_cw() {
                cw_ = (cw_ << 1) + 1;
                if(cw_ > phymib_->CWMax)
                        cw_ = phymib_->CWMax;
        }
        inline void rst_cw() { cw_ = phymib_->CWMin; }
        inline double sec(double t) { return(t *= 1.0e-6); }
        inline u_int16_t usec(double t) {
                u_int16_t us = (u_int16_t)floor((t *= 1e6) + 0.5);
                /* u_int16_t us = (u_int16_t)rint(t *= 1e6); */
                return us;
        }
        inline void set_nav(u_int16_t us) {
                double now = Scheduler::instance().clock();
                double t = us * 1e-6;

                if((now + t) > nav_) {
                        nav_ = now + t;
                        if(mhNav_.busy())
                                mhNav_.stop();
                        mhNav_.start(t);
                }
        }

protected:
        PHY_MIB         *phymib_;
        MAC_MIB         *macmib_;

private:
        double          basicRate_;
        double          dataRate_;
        
        /*
         * Mac Timers
         */
        IFTimer         mhIF_;          // interface timer
        NavTimer        mhNav_;         // NAV timer
        RxTimer         mhRecv_;                // incoming packets
        TxTimer         mhSend_;                // outgoing packets

        DeferTimer      mhDefer_;       // defer timer
        BackoffTimer    mhBackoff_;     // backoff timer

        /* ============================================================
           Internal MAC State
           ============================================================ */
        double          nav_;           // Network Allocation Vector

        MacState        rx_state_;      // incoming state (MAC_RECV or MAC_IDLE)
        MacState        tx_state_;      // outgoint state
        int             tx_active_;     // transmitter is ACTIVE

        Packet          *pktRTS_;       // outgoing RTS packet
        Packet          *pktCTRL_;      // outgoing non-RTS packet

        u_int32_t       cw_;            // Contention Window
        u_int32_t       ssrc_;          // STA Short Retry Count
        u_int32_t       slrc_;          // STA Long Retry Count
        double          sifs_;          // Short Interface Space
        double          pifs_;          // PCF Interframe Space
        double          difs_;          // DCF Interframe Space
        double          eifs_;          // Extended Interframe Space
        double          tx_sifs_;
        double          tx_pifs_;
        double          tx_difs_;

        int             min_frame_len_;

        NsObject*       logtarget_;

        /* ============================================================
           Duplicate Detection state
           ============================================================ */
        u_int16_t       sta_seqno_;     // next seqno that I'll use
        int             cache_node_count_;
        Host            *cache_;
};

#endif /* __mac_80211_h__ */

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