mac-802_11e.cc

在网络仿真模拟工具下实现支持QoS的MAC层EDCF协议

#undef NDEBUG
#include <assert.h>
#include "delay.h"
#include "connector.h"
#include "packet.h"
#include "random.h"
#include "mobilenode.h"
#include "stream.h"

#include "arp.h"
#include "ll.h"
#include "mac.h"
#include "mac-timers_802_11e.h"
#include "mac-802_11e.h"
#include "cmu-trace.h"
#include "priq.h"
//include the following line when using Akaroa
//#include "akaroa.H"
#define AKAROA 0 
#define INTERVAL 0.01 
// XXX Can't we make these macros inline methods? Otherwise why should we have
// inline methods at all??
#define CHECK_BACKOFF_TIMER() 					                \
{									        \
	if(is_idle() && mhBackoff_.paused()) { 				        \
            mhBackoff_.resume();				                \
	}                                                                       \
	if(! is_idle() && mhBackoff_.busy() && ! mhBackoff_.paused()){	        \
		mhBackoff_.pause();					        \
        }                                                                       \
 if(!is_idle() && mhDefer_.busy()) mhDefer_.stop();                             \
}


inline void
Mac802_11e::transmit(Packet *p, double t)
{                                                                       
	/*                                                              
         * If I'm transmitting without doing CS, such as when           
         * sending an ACK, any incoming packet will be "missed"         
         * and hence, must be discarded.                                
         */                                                             
         if(rx_state_ != MAC_IDLE) {                                     
                struct hdr_mac802_11 *dh = HDR_MAC802_11(p);            
                                                                        
                assert(dh->dh_fc.fc_type == MAC_Type_Control);          
                assert(dh->dh_fc.fc_subtype == MAC_Subtype_ACK);        
                                                                        
                assert(pktRx_);                                         
                struct hdr_cmn *ch = HDR_CMN(pktRx_);                   
                                                                        
                ch->error() = 1;        /* force packet discard */      
        }                                                               
                                                                        
        /*                                                              
         * pass the packet on the "interface" which will in turn        
         * place the packet on the channel.                             
         *                                                              
         * NOTE: a handler is passed along so that the Network          
         *       Interface can distinguish between incoming and         
         *       outgoing packets.                                      
         */
	struct hdr_cmn *sd = HDR_CMN(p);
	int prio = LEVEL(p);
	tx_active_ = 1;
	sending = 1;
	CHECK_BACKOFF_TIMER();

	downtarget_->recv(p->copy(), this);
	if(sd->ptype() == PT_CBR || sd->ptype() == PT_EXP) {
	  if(!rtx_[prio]){
	    numbytes_[prio] += sd->size() - ETHER_HDR_LEN11;
	  }
	} 
	mhIF_.start(txtime(p));  
	mhSend_.start(t);                      

	                                       
} 




#define SET_RX_STATE(x) 		                            \
{	                                                            \
	rx_state_ = x;		                                    \
	CHECK_BACKOFF_TIMER();  	                            \
}

#define SET_TX_STATE(pri, x)			                    \
{						                    \
	tx_state_[pri] = x;			                    \
}

/* ======================================================================
   Global Variables
   ====================================================================== */

static EDCF_PHY_MIB EDCF_PMIB =
{
        DSSS_EDCF_SlotTime, DSSS_EDCF_CCATime,
	DSSS_EDCF_RxTxTurnaroundTime, DSSS_EDCF_SIFSTime, DSSS_EDCF_PreambleLength,
	DSSS_EDCF_PLCPHeaderLength, DSSS_EDCF_PLCPDataRate
};	

static MAC_MIB EDCF_MMIB =
{
	MAC_EDCF_RTSThreshold, MAC_EDCF_ShortRetryLimit,
	MAC_EDCF_LongRetryLimit, MAC_EDCF_FragmentationThreshold,
	MAC_EDCF_MaxTransmitMSDULifetime, MAC_EDCF_MaxReceiveLifetime,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

/* ======================================================================
   TCL Hooks for the simulator
   ====================================================================== */
static class Mac802_11eClass : public TclClass {
public:
	Mac802_11eClass() : TclClass("Mac/802_11e") {}
	TclObject* create(int, const char*const*) {
		return (new Mac802_11e(&EDCF_PMIB, &EDCF_MMIB));
	}
} class_mac802_11e;


/* ======================================================================
   Mac Class Functions
   ====================================================================== */
Mac802_11e::Mac802_11e(EDCF_PHY_MIB *p, MAC_MIB *m) : Mac(), mhIF_(this), mhNav_(this), mhRecv_(this), mhSend_(this), mhDefer_(this, p->SlotTime), mhSifs_(this, p->SlotTime), mhBackoff_(this, p->SlotTime), AK(this)
{
        // Pointer to PriQ, Cast in priq.cc
	queue_  = 0;
	
	//flags to control if PriQ Parameters have already been adopted
	AIFSset = 0;
	CWset   = 0;
	for(int i=0; i < MAX_PRI; i++){
	    packets_[i] = 0;
	    pktRTS_[i] = 0;
	    pktCTRL_[i] = 0;
	    pktTx_[i] = 0;
	    tx_state_[i] = MAC_IDLE;
	    ssrc_[i] = slrc_[i] = 0;
	    callback_[i] = 0;
	    numbytes_[i] = 0;
	    rtx_[i] = 0;
	    cw_[i] = 0;
	    cwmin_[i] = 0;
	    cwmax_[i] = 0;
	    aifs_[i] = 0;
	    txop_limit_[i] = 0;
	} 
        jitter  =    1000;
	//jitter =   0;
	throughput = 0;
	interval_ =  INTERVAL;
        if(AKAROA) AK.start();
	macmib_ =    m;
	phymib_ =    p;
	
	nav_ =       0.0;
	
	rx_state_ =  MAC_IDLE;
	tx_active_ = 0;    
      	
	idle_time =     0;
	sending =       0;
	cfb_dur =       0;
	cfb_active =    0;
        cfb_broadcast = 0;
	
	levels =     0;
	slotnum =    0;
	pf =         0;
	cw_old =     0;

	sifs_ = phymib_->SIFSTime;
	pifs_ = sifs_ + phymib_->SlotTime;
	difs_ = sifs_ + 2*phymib_->SlotTime;
		
        // see (802.11-1999, 9.2.10) 
	eifs_ = sifs_ + (8 * ETHER_ACK_LEN / phymib_->PLCPDataRate);
//	eifs_ = sifs_ + (8 * ETHER_ACK_LEN / phymib_->PLCPDataRate) + difs_;
	
	eifs_nav_ =  0;
	//tx_sifs_ = sifs_ - phymib_->RxTxTurnaroundTime;
	//tx_pifs_ = tx_sifs_ + phymib_->SlotTime;
	//tx_difs_ = tx_sifs_ + 2 * phymib_->SlotTime;
	
	sta_seqno_ =        1;
	cache_ =            0;
	cache_node_count_ = 0;
	
        // chk if basic/data rates are set
	// otherwise use bandwidth_ as default;
	
	Tcl& tcl = Tcl::instance();
	tcl.evalf("Mac/802_11e set basicRate_");
	if (strcmp(tcl.result(), "0") != 0) 
		bind_bw("basicRate_", &basicRate_);
	else
	    basicRate_ = bandwidth_;

	tcl.evalf("Mac/802_11e set dataRate_");
	if (strcmp(tcl.result(), "0") != 0) 
	  bind_bw("dataRate_", &dataRate_);
	else
	  dataRate_ = bandwidth_;
	  
	tcl.evalf("Mac/802_11e set rst_cw_mode_");
	if (strcmp(tcl.result(), "0") != 0) 
	  bind("rst_cw_mode_", &rst_cw_mode_);
	else
	  rst_cw_mode_=0;
	  	
	bind("cfb_", &cfb_);
}


int
Mac802_11e::command(int argc, const char*const* argv)
{
	if (argc == 3) {
	    if (strcmp(argv[1], "log-target") == 0) {
		logtarget_ = (NsObject*) TclObject::lookup(argv[2]);
		if(logtarget_ == 0)
		    return TCL_ERROR;
		return TCL_OK;
	    } else if(strcmp(argv[1], "nodes") == 0) {
		if(cache_) return TCL_ERROR;
		cache_node_count_ = atoi(argv[2]);
		cache_ = new Host[cache_node_count_ + 1];
		assert(cache_);
		bzero(cache_, sizeof(Host) * (cache_node_count_+1 ));
		return TCL_OK;
	    }
	}
	// wiethoelter, 28.07.03
	// VOIP-Projekt
        // Zugriff auf das RetryLimit des MAC-Layers vom RTPData-Agent aus

        Tcl& tcl = Tcl::instance();

        if ( argc == 2 ) {
                if ( strcmp( argv[1], "set_RetryLimit" ) == 0 ) {
                        tcl.resultf( "%d", macmib_->ShortRetryLimit );
                        return TCL_OK;
                }
        }

        if ( argc == 3 ) {
                if ( strcmp( argv[1], "set_RetryLimit" ) == 0 ) {
                        macmib_->ShortRetryLimit = atoi( argv[2] );;
                        return TCL_OK;
                }
        }


	return Mac::command(argc, argv);
}

/* ======================================================================
   Debugging Routines
   ====================================================================== */

/*
 * dump and packet trace are not adopted to 802.11e yet!
 */

void
Mac802_11e::trace_pkt(Packet *p) {
	struct hdr_cmn *ch = HDR_CMN(p);
	struct hdr_mac802_11* dh = HDR_MAC802_11(p);
	u_int16_t *t = (u_int16_t*) &dh->dh_fc;

	fprintf(stderr, "\t[ %2x %2x %2x %2x ] %x %s %d\n",
		*t, dh->dh_duration,
		ETHER_ADDR(dh->dh_da), ETHER_ADDR(dh->dh_sa),
		index_, packet_info.name(ch->ptype()), ch->size());
}

void
Mac802_11e::dump(char *fname)
{
	fprintf(stderr,
		"\n%s --- (INDEX: %d, time: %2.9f)\n",
		fname, index_, Scheduler::instance().clock());

	fprintf(stderr,
		"\ttx_state_: %x, rx_state_: %x, nav: %2.9f, idle: %d\n",
		tx_state_, rx_state_, nav_, is_idle());

	fprintf(stderr,
		"\tpktTx_: %x, pktRx_: %x, pktRTS_: %x, pktCTRL_: %x, callback: %x\n",
		(int) pktTx_, (int) pktRx_, (int) pktRTS_,
		(int) pktCTRL_, (int) callback_);

	fprintf(stderr,
		"\tDefer: %d, Backoff: %d (%d), Recv: %d, Timer: %d Nav: %d\n",
		mhDefer_.busy(), mhBackoff_.busy(), mhBackoff_.paused(),
		mhRecv_.busy(), mhSend_.busy(), mhNav_.busy());
	fprintf(stderr,
		"\tBackoff Expire: %f\n",
		mhBackoff_.expire());
}


/* ======================================================================
   Packet Headers Routines
   ====================================================================== */
inline int
Mac802_11e::hdr_dst(char* hdr, int dst )
{
	struct hdr_mac802_11 *dh = (struct hdr_mac802_11*) hdr;
	//dst = (u_int32_t)(dst);

	if(dst > -2)
		STORE4BYTE(&dst, (dh->dh_da));

	return ETHER_ADDR(dh->dh_da);
}

inline int 
Mac802_11e::hdr_src(char* hdr, int src )
{
	struct hdr_mac802_11 *dh = (struct hdr_mac802_11*) hdr;
	if(src > -2)
		STORE4BYTE(&src, (dh->dh_sa));
	return ETHER_ADDR(dh->dh_sa);
}

inline int 
Mac802_11e::hdr_type(char* hdr, u_int16_t type)
{
	struct hdr_mac802_11 *dh = (struct hdr_mac802_11*) hdr;
	if(type)
		STORE2BYTE(&type,(dh->dh_body));
	return GET2BYTE(dh->dh_body);
}


/* ======================================================================
   Misc Routines
   ====================================================================== */
inline int
Mac802_11e::is_idle()
{
    if(rx_state_ != MAC_IDLE){
      idle_time = 0;
      return 0;
    }
    if(sending) {
      idle_time = 0;
      return 0;
    }
    
    if(nav_ > Scheduler::instance().clock()){
      idle_time = 0;
      return 0;
    }
    idle_time = Scheduler::instance().clock();
    return 1;
}

void
Mac802_11e::discard(Packet *p, const char* why)
{
	hdr_mac802_11* mh = HDR_MAC802_11(p);
	hdr_cmn *ch = HDR_CMN(p);

#if 0
	/* old logic 8/8/98 -dam */
	/*
	 * If received below the RXThreshold, then just free.
	 */
	if(p->txinfo_.Pr < p->txinfo_.ant.RXThresh) {
		Packet::free(p);
		//p = 0;
		return;
	}
#endif // 0

	/* if the rcvd pkt contains errors, a real MAC layer couldn't
	   necessarily read any data from it, so we just toss it now */
	if(ch->error() != 0) {
		Packet::free(p);
		//p = 0;
		return;
	}

	switch(mh->dh_fc.fc_type) {
	case MAC_Type_Management:
		drop(p, why);
		return;
	case MAC_Type_Control:
		switch(mh->dh_fc.fc_subtype) {
		case MAC_Subtype_RTS:
			if((u_int32_t)ETHER_ADDR(mh->dh_sa) == \
			   (u_int32_t)index_) {
				drop(p, why);
				return;
			}
			/* fall through - if necessary */
		case MAC_Subtype_CTS:
		case MAC_Subtype_ACK:
			if((u_int32_t)ETHER_ADDR(mh->dh_da) == \
			   (u_int32_t)index_) {
				drop(p, why);
				return;
			}
			break;
		default:
			fprintf(stderr, "invalid MAC Control subtype\n");
			exit(1);
		}
		break;
	case MAC_Type_Data:
		switch(mh->dh_fc.fc_subtype) {
		case MAC_Subtype_Data:
			if((u_int32_t)ETHER_ADDR(mh->dh_da) == \
			   (u_int32_t)index_ ||
			   (u_int32_t)ETHER_ADDR(mh->dh_sa) == \
			   (u_int32_t)index_ ||
			   (u_int32_t)ETHER_ADDR(mh->dh_da) == MAC_BROADCAST) {
				drop(p);
				return;
			}
			break;
		default:
			fprintf(stderr, "invalid MAC Data subtype\n");
			exit(1);
		}
		break;
	default:
		fprintf(stderr, "invalid MAC type (%x)\n", mh->dh_fc.fc_type);
		trace_pkt(p);
		exit(1);
	}
	Packet::free(p);
}

void
Mac802_11e::capture(Packet *p)
{
	/*
	 * Update the NAV so that this does not screw
	 * up carrier sense.
	 */
    	set_nav(usec(eifs_ + txtime(p)));
		      Packet::free(p);
}

void
Mac802_11e::collision(Packet *p)
{
	switch(rx_state_) {
	case MAC_RECV:
		SET_RX_STATE(MAC_COLL);
		/* fall through */
	case MAC_COLL:
		assert(pktRx_);
		assert(mhRecv_.busy());
		/*
		 *  Since a collision has occurred, figure out
		 *  which packet that caused the collision will
		 *  "last" the longest.  Make this packet,
		 *  pktRx_ and reset the Recv Timer if necessary.
		 */
		if(txtime(p) > mhRecv_.expire()) {
			mhRecv_.stop();
			discard(pktRx_, DROP_MAC_COLLISION);
			pktRx_ = p;
			mhRecv_.start(txtime(pktRx_));
		}
		else {
			discard(p, DROP_MAC_COLLISION);
		}
		break;
	default:
		assert(0);
	}
}

void
Mac802_11e::tx_resume()
{
	double rTime;
	assert(mhSend_.busy() == 0);
	
	for(int pri = 0; pri < MAX_PRI; pri++){
	    //assert(mhDefer_.defer(pri) == 0);
	    if(!mhDefer_.defer(pri)) {
		if(pktCTRL_[pri]) {
		/*
		 *  Need to send a CTS or ACK.
		 */
		    mhSifs_.start(pri, sifs_);
		} else if(pktRTS_[pri]) {
		    if(mhBackoff_.backoff(pri) == 0) {
		      rTime = (Random::random() % getCW(LEVEL(pktRTS_[pri]))) * phymib_->SlotTime;
		      mhDefer_.start(pri, getAIFS(LEVEL(pktRTS_[pri]))); 
		    }
		} else if(pktTx_[pri]) {
		    if(mhBackoff_.backoff(pri) == 0) {
			hdr_cmn *ch = HDR_CMN(pktTx_[pri]);
			struct hdr_mac802_11 *mh = HDR_MAC802_11(pktTx_[pri]);
			
			if ((u_int32_t) ch->size() < macmib_->RTSThreshold ||
			    (u_int32_t) ETHER_ADDR(mh->dh_da) == MAC_BROADCAST) {
			  
			  if((u_int32_t) ETHER_ADDR(mh->dh_da) == MAC_BROADCAST) rTime = (Random::random() % (getCW(pri) + 1)) * phymib_->SlotTime;
			  else rTime = 0;
			    mhDefer_.start(pri, getAIFS(pri) + rTime);
			} else {
			    mhSifs_.start(pri, sifs_); 
			}
		    }
		} else if(callback_[pri] != 0) {
		  rtx_[pri] = 0;
		  Handler *h = callback_[pri];
		  callback_[pri] = 0;
		  h->handle((Event*) 0);
		}
		SET_TX_STATE(pri, MAC_IDLE);
	    }
	}
}

void
Mac802_11e::rx_resume()
{
  assert(pktRx_ == 0);
    assert(mhRecv_.busy() == 0);
    SET_RX_STATE(MAC_IDLE);
}


/* ======================================================================
   Timer Handler Routines
   ====================================================================== */
void
Mac802_11e::backoffHandler(int pri)
{
   if(pktCTRL_[pri]) {
    assert(mhSend_.busy() || mhDefer_.defer(pri));
    return;
  }
  
  if(check_pktRTS(pri) == 0)
    return;
  
  if(check_pktTx(pri) == 0)
    return;
}

void
Mac802_11e::deferHandler(int pri)
{
	assert(pktCTRL_[pri] || pktRTS_[pri] || pktTx_[pri]);

	if(check_pktCTRL(pri) == 0)
		return;

	assert(mhBackoff_.backoff(pri) == 0);
	//if (mhBackoff_.busy() != 0)
	//{
	//	printf("deferHandler:mhBackoff_ busy!\n");
	//	return;
	//}
	if(check_pktRTS(pri) == 0)
		return;

	if(check_pktTx(pri) == 0)
		return;
}

void
Mac802_11e::navHandler()
{
    eifs_nav_ = 0.0;
    if(is_idle() && mhBackoff_.paused()) {
		mhBackoff_.resume();
    }
}

void
Mac802_11e::recvHandler()
{
    
	recv_timer();
}

void
Mac802_11e::sendHandler()
{
    Scheduler &s = Scheduler::instance();
    sending = 0;
    CHECK_BACKOFF_TIMER();
    send_timer();
}


void