mac-802_11.cc

TCP westwood code, download

		return 0;						// 0 == FALSE --> NOT IDLE
	if(tx_state_ != MAC_IDLE)
		return 0;
	if(nav_[nav_tc_] > Scheduler::instance().clock())
		return 0;

	return 1;
}

void
Mac802_11::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_QoS_Null:
		case MAC_Subtype_QoS_CFPoll:
		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_11::capture(Packet *p)
{
	/*
	 * Update the NAV so that this does not screw
	 * up carrier sense.
	 */
	for(int i=0; i<=7; i++) set_nav(usec(eifs_ + txtime(p)),i);
	Packet::free(p);
}

void
Mac802_11::collision(Packet *p)
{
	//printf("Detected collision at node %d...\n",index_);
	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_11::tx_resume()
{
	double rTime;
	assert(mhSend_.busy() == 0);
	//assert(mhDefer_[tc_].busy() == 0);

	if(pktCTRL_) {
		/*
		 *  Need to send a CTS or ACK.
		 */
		 // My BugFix 
		if (mhDefer_[tc_].busy()) {
			mhDefer_[tc_].stop();
			if (!mhBackoff_[tc_].busy()) mhBackoff_[tc_].start(cw_[tc_],0);
		}
		mhDefer_[tc_].start(sifs_);
	} else if(pktRTS_) {
		if(mhBackoff_[tc_].busy() == 0) {
			rTime = (Random::random() % cw_[tc_]) * phymib_->SlotTime;
			mhDefer_[tc_].start(aifs_[tc_] + rTime);
		}
	} 
//@@ FaZ
	else if (pktSchElem_) {
		//printf("In tx_resume cerco di inviare pktSchElem_ ... \n");
		int idle=0;
		for(int i=0;i<=7;i++) idle+=(nav_[i]<=Scheduler::instance().clock());
		if (idle==8 && rx_state_==MAC_IDLE) {
			//printf("Sending Schedule Element at time %2.9f\n",Scheduler::instance().clock()); // polling DELAY DEBUG
			if (mhDefer_[tc_].busy()) mhDefer_[tc_].stop();
			mhDefer_[tc_].start(pifs_);
		}
		//printf("Fatto!!!\n");
	}

//@ FaZ
	else 	if(pktQoSTx_[tc_]) {
		if (btbs_) {		
			int idle=0;
			for(int i=0;i<=7;i++) idle+=(mhBackoff_[i].busy()==0 || (mhBackoff_[i].busy() && mhBackoff_[i].paused()))+(mhDefer_[i].busy()==0);
			if (idle==16 && rx_state_==MAC_IDLE) { 
				//printf("OK->Defer PIFS tx %2.6f\n",Scheduler::instance().clock()); // BEACON DELAY DEBUG
				mhDefer_[tc_].start(pifs_);
				btbs_=0;
			}
		} /*else if (pktQoSPoll_ && (!pktCTRL_)) {
			int idle=0;
			for(int i=0;i<=7;i++) idle+=(mhBackoff_[i].busy()==0 || (mhBackoff_[i].busy() && mhBackoff_[i].paused()))+(mhDefer_[i].busy()==0);
			if (idle==16 && rx_state_==MAC_IDLE) { 
				//printf("\tOK->Defer PIFS tx %2.6f\n",Scheduler::instance().clock()); // polling DELAY DEBUG
				if (mhDefer_[tc_].busy()) mhDefer_[tc_].stop();
				mhDefer_[tc_].start(pifs_);
				ptbs_=0;
			}
		}*/
		if(mhBackoff_[tc_].busy() == 0) {
			hdr_cmn *ch = HDR_CMN(pktQoSTx_[tc_]);
			struct hdr_mac802_11 *mh = HDR_MAC802_11(pktQoSTx_[tc_]);
			if ((u_int32_t) ch->size() < macmib_->RTSThreshold || (u_int32_t) ETHER_ADDR(mh->dh_da) == MAC_BROADCAST) {
				//rTime = (Random::random() % cw_[tc_]) * phymib_->SlotTime;
				//mhDefer_[tc_].start(aifs_[tc_] + rTime);
				mhBackoff_[tc_].start(cw_[tc_],is_idle(tc_));
			} else {
				mhDefer_[tc_].start(sifs_);
			}
		}
	} else if(QoScallback_[tc_]) {
		Handler *h = QoScallback_[tc_];
		QoScallback_[tc_] = 0;
		h->handle((Event*) 0);
	}
	
	if (btbs_) {		
		int idle=0;
		for(int i=0;i<=7;i++) idle+=(nav_[i]<=Scheduler::instance().clock());
		if (idle==8 && rx_state_==MAC_IDLE) {
			//printf("OK->Defer PIFS tx %2.6f\n",Scheduler::instance().clock()); // BEACON DELAY DEBUG
			if (mhDefer_[tc_].busy()) mhDefer_[tc_].stop();
			mhDefer_[tc_].start(pifs_);
			btbs_=0;
		}
	} else if (pktQoSPoll_ && (!pktCTRL_)) {		
		int idle=0;
		for(int i=0;i<=7;i++) idle+=(nav_[i]<=Scheduler::instance().clock());
		if (idle==8) {
			//printf("\tOK->Defer PIFS tx %2.6f\n",Scheduler::instance().clock()); // polling DELAY DEBUG
			if (mhDefer_[tc_].busy()) mhDefer_[tc_].stop();
			mhDefer_[tc_].start(pifs_);
			ptbs_=0;
		}
	} 
//@@ FaZ
/*
	else if (pktSchElem_ && (!pktCTRL_)) {		
		//printf("In tx_resume cerco di inviare pktSchElem_ ... \n");
		int idle=0;
		for(int i=0;i<=7;i++) idle+=(nav_[i]<=Scheduler::instance().clock());
		if (idle==8 && rx_state_==MAC_IDLE) {
			//printf("Sending Schedule Element at time %2.9f\n",Scheduler::instance().clock()); // polling DELAY DEBUG
			if (mhDefer_[tc_].busy()) mhDefer_[tc_].stop();
			mhDefer_[tc_].start(pifs_);
		}
		//printf("Fatto!!!\n");
	}
//@ FaZ
*/
	SET_TX_STATE(MAC_IDLE);
}

void
Mac802_11::rx_resume()
{
	assert(pktRx_ == 0);
	assert(mhRecv_.busy() == 0);
	if (btbs_) {		
		int idle=0;
		for(int i=0;i<=7;i++) idle+=(nav_[i]<=Scheduler::instance().clock());
		if (idle==8 && tx_state_==MAC_IDLE) {
			//printf("OK->Defer PIFS rx %2.6f\n",Scheduler::instance().clock()); // BEACON DELAY DEBUG
			if (mhDefer_[tc_].busy()) mhDefer_[tc_].stop();
			mhDefer_[tc_].start(pifs_);
			btbs_=0;
		}
	}
	if (pktQoSPoll_ && (!pktCTRL_)) {		
		int idle=0;
		for(int i=0;i<=7;i++) idle+=(nav_[i]<=Scheduler::instance().clock());
		if (idle==8 && tx_state_==MAC_IDLE) {
			//printf("\tOK->Defer PIFS rx %2.6f\n",Scheduler::instance().clock()); // polling DELAY DEBUG
			if (mhDefer_[tc_].busy()) mhDefer_[tc_].stop();
			mhDefer_[tc_].start(pifs_);
			ptbs_=0;
		}
	}
		
	SET_RX_STATE(MAC_IDLE);
}


/* ======================================================================
   Timer Handler Routines
   ====================================================================== */
void
Mac802_11::backoffHandler(u_int32_t winner_tc_)
{
//@@ FaZ
	EnergyModel *em = netif_->node()->energy_model();
	
	if (em && em->sleep()) {
		printf("Node %d is sleeping at %2.9f, exiting backoff...\n",index_,Scheduler::instance().clock());
		return;
	}
//@ FaZ


	int highest=8;
	for(int i=0; i<=7; i++) { // TC=0 highest priority, .... TC=7 lower priority
		// check for virtual collisions
		if (mhBackoff_[i].busy() && mhBackoff_[i].expire()==0.0) {
			// virtual collision found
			//printf(" Node %d: VIRTUAL COLLISION occurred\n",index_);
			if (i<=highest && i<winner_tc_) { 
				highest=i; 
				//printf(" Node %d, TC %d: VIRTUAL COLLISION WINNER\n",index_,i);
			}
			else { mhBackoff_[i].stop(); inc_cw(i); mhBackoff_[i].start(cw_[i],0); }
		}
	}
	if (highest<winner_tc_) {
		inc_cw(winner_tc_);
		mhBackoff_[winner_tc_].start(cw_[winner_tc_],0);
		return;
	}


/*
//@@ FaZ
	int highest=0; //non dovrebbe essere 0 ma -1 (se lo metto si blocca) ... tanto l'AC=0 non viene usata :P
	for(int i=7; i>=0; i--) { // TC=7 highest priority, .... TC=0 lower priority
		// check for virtual collisions
		if (mhBackoff_[i].busy() && mhBackoff_[i].expire()==0.0) {
			// virtual collision found
			//printf(" Node %d: VIRTUAL COLLISION occurred\n",index_);
			if (i>=highest && i>winner_tc_) { 
				highest=i; 
				//printf(" Node %d, TC %d: VIRTUAL COLLISION WINNER\n",index_,i);
			}
			else { mhBackoff_[i].stop(); inc_cw(i); mhBackoff_[i].start(cw_[i],0); }
		}
	}
	if (highest>winner_tc_) {
		inc_cw(winner_tc_);
		mhBackoff_[winner_tc_].start(cw_[winner_tc_],0);
		return;
	}
//@ FaZ
*/
	
	//tc_=winner_tc_;
	//if (index_==0) printf(" BackoffHandler winner TC: %d\n",tc_);
	if(pktCTRL_) {
		assert(mhSend_.busy() || mhDefer_[winner_tc_].busy());
		return;
	}

	tc_=winner_tc_;

	if(check_pktRTS() == 0)
		return;

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

void
Mac802_11::deferHandler(u_int32_t winner_tc_)
{

//@@ FaZ
	EnergyModel *em = netif_->node()->energy_model();
	
	if (em && em->sleep()) {
		//printf("Node %d is sleeping at %2.9f, exiting defer...",index_,Scheduler::instance().clock());
		return;
	}
//@ FaZ

	if (check_pktQoSNull() == 0) return;