ll.cc

一个很好的LINUX底下的GPRS协议栈

			
			llhsp->seqno_ = 0;
			llhsp->bopno_ = bopno;
			llhsp->eopno_ = eopno;
			llhsp->psize_ = ch->size_;
			chsp->size_  = psize;
			
			if((acked_==0)||(chsp->next_hop()==-1)){
				if(i==eopno)
					llhsp->seqno_=eopno;
		
				// XXX HACK for now - Padma, 03/99.
				nsaddr_t dst = (nsaddr_t)Address::instance().get_nodeaddr(ihsp->daddr());
				
				int tx = 0;
	
				switch(chsp->addr_type()) {
				case NS_AF_ILINK:
						mac_->hdr_dst((char*) HDR_MAC(sp), chsp->next_hop());
						break;

				case NS_AF_INET:
						dst = chsp->next_hop();
						/* FALL THROUGH */
		
				case NS_AF_NONE:
		
						if (IP_BROADCAST == (u_int32_t) dst)
						{
							mac_->hdr_dst((char*) HDR_MAC(sp), MAC_BROADCAST);
							break;
						}
						/* Assuming arptable is present, send query */
						if (arptable_) {
							tx = arptable_->arpresolve(dst, sp, this);
							break;
						}
						/* FALL THROUGH */

				default:
		
					int IPnh = (lanrouter_) ? lanrouter_->next_hop(sp) : -1;
					if (IPnh < 0)
						mac_->hdr_dst((char*) HDR_MAC(sp),macDA_);
					else if (varp_)
						tx = varp_->arpresolve(IPnh, sp);
					else
						mac_->hdr_dst((char*) HDR_MAC(sp), IPnh);
					break;
				}

			if(tx==0){
				Scheduler& s = Scheduler::instance();
				s.schedule(downtarget_, sp, delay_);
				if (llverbose_==1) fprintf(stderr,"<%d> %f LL: send down NON-ack uid=%d\n", mac_->addr(), NOW ,chsp->uid_);
			}
			}else{
				llhsp->seqno_=i;
				seqno_++;
				buf_->enque(sp);    
				if (llverbose_==1) fprintf(stderr,"<%d> %f LL: buffering ll_seq=%d pktuid=%d bufq_length=%d \n",
						mac_->addr(), NOW, llhsp->seqno_, chsp->uid_, buf_->length() );
			}
		}	
		if(acked_==1)
			sendDownDATA();
}

void LL::sendDownDATA(void)
{
	Packet* sp;
	if(!(sp = buf_->deque())){
		if (llverbose_==1) fprintf(stderr,"<%d> %f LL: bufq is empty\n", mac_->addr(), NOW );
		return;
	}
	
	hdr_cmn *chsp = HDR_CMN(sp);
	hdr_ll *llhsp = HDR_LL(sp);
	hdr_ip *ihsp = HDR_IP(sp);
	
	if (ackno_ == llhsp->seqno_){  //send new pkt if ack no matches with new pkt to be sent
	
		if (llverbose_==1) fprintf(stderr ,"<%d> %f LL: last ack=%d, send down pktuid=%d ll_seq=%d bopno=%d eopno=%d\n",
				mac_->addr(), NOW ,ackno_, chsp->uid_,llhsp->seqno_,llhsp->bopno_,llhsp->eopno_);   
		pktTx_ = sp->copy();
	
	// moved frm above due to arp schedules
	// XXX HACK for now - Padma, 03/99.
		nsaddr_t dst = (nsaddr_t)Address::instance().get_nodeaddr(ihsp->daddr());
		int tx = 0;
	
		switch(chsp->addr_type()) {

		case NS_AF_ILINK:
			mac_->hdr_dst((char*) HDR_MAC(sp), chsp->next_hop());
			break;

		case NS_AF_INET:
			dst = chsp->next_hop();
			/* FALL THROUGH */
		
		case NS_AF_NONE:
		
			if (IP_BROADCAST == (u_int32_t) dst)
			{
				mac_->hdr_dst((char*) HDR_MAC(sp), MAC_BROADCAST);
				break;
			}
			/* Assuming arptable is present, send query */
			if (arptable_) {
				tx = arptable_->arpresolve(dst, sp, this);
				break;
			}
			//if (varp_) {
			//tx = varp_->arpresolve(dst, p);
			//break;
			
			//}			
			/* FALL THROUGH */

		default:
		
			int IPnh = (lanrouter_) ? lanrouter_->next_hop(sp) : -1;
			if (IPnh < 0)
				mac_->hdr_dst((char*) HDR_MAC(sp),macDA_);
			else if (varp_)
				tx = varp_->arpresolve(IPnh, sp);
			else
				mac_->hdr_dst((char*) HDR_MAC(sp), IPnh);
			break;
		}

		if(tx==0){
			Scheduler& s = Scheduler::instance();
		// let mac decide when to take a new packet from the queue.
			s.schedule(downtarget_, sp, delay_);
			lhSend_.stop();
			lhSend_.start(0.5);//?? why 1.5 rj
		}
	}
	else{
		if (llverbose_==1) fprintf(stderr,"<%d> %f LL: expected pkt(last ack)=%d, this pkt=%d\n", 
				mac_->addr(), NOW, ackno_, llhsp->seqno_);
		buf_->enqueHead(sp);
	}
}

void LL::recvACK(Packet* p)
{
	hdr_ll *llh = HDR_LL(p);
	if(ackno_ < llh->ackno_){
		ackno_ = llh->ackno_;
		lhSend_.stop();
		datacounter=0;
	}
	if (llverbose_==1) fprintf(stderr,"<%d> %f LL: recvd ACK num %d\n", mac_->addr(), NOW, llh->ackno_);
	sendDownDATA();
}


void LL::sendUpDATA(Packet* p)
{
	acSend_.stop();
	ackcounter=0;   //see if req...was working fine
	if (hdr_cmn::access(p)->error() > 0)
		drop(p);
	else{
		hdr_cmn *ch = HDR_CMN(p);
		hdr_ll *llh = HDR_LL(p);
		hdr_ip *iph = HDR_IP(p);
	
		
		if(((ch->next_hop_)!=-1)&&(acked_==1)){
			sendACK(p);
		}
		if ( llh->seqno_ == llh->eopno_ ){
			ch->size_=llh->psize_;
		  	if (llverbose_==1) fprintf(stderr , "<%d> %f LL: all LL frags for pkt uid=%d recvd. sending up.ll_seqno=ll_eopno=%d \n",
					mac_->addr(), NOW, ch->uid_, llh->eopno_);   
			Scheduler& s = Scheduler::instance();
			s.schedule(uptarget_, p, delay_);
		} else { 
		   if (llverbose_==1) fprintf(stderr , "<%d> %f LL: frag with ll_seqno=%d recvd. for pkt uid=%d ll_eopno=%d\n",
				   mac_->addr(), NOW, llh->seqno_, ch->uid_, llh->eopno_);   
			  Packet::free(p);   
		}
	}
}

void LL::sendACK(Packet* p)
{
		hdr_cmn *ch = HDR_CMN(p);
		hdr_ll *llh = HDR_LL(p);
		hdr_ip *iph = HDR_IP(p);
		hdr_mac_gprs *dh = HDR_MAC_GPRS(p);
		char *mh = (char*)p->access(hdr_mac::offset_);
		
		Packet* sp = Packet::alloc();
		
		hdr_cmn *chsp = HDR_CMN(sp);
		hdr_ll *llhsp = HDR_LL(sp);
		hdr_ip *iphsp = HDR_IP(sp);
		char *mhsp = (char *)HDR_MAC(sp);
// 		char *mhsp = (char*)sp->access(hdr_mac::offset_);
		
		iphsp->src_ = iph->dst_;
		iphsp->dst_ = iph->src_;

//		chsp->next_hop_ = ch->prev_hop_;
		chsp->next_hop_=Address::instance().get_nodeaddr(iph->saddr());	
//		chsp->prev_hop_ = ch->next_hop_;
		chsp->prev_hop_=Address::instance().get_nodeaddr(iph->daddr());	
		chsp->addr_type_ = ch->addr_type_;
		chsp->direction_ = hdr_cmn::DOWN;
		chsp->ptype_=PT_LLACK; 
		chsp->size_=6;
		chsp->iface()= -2;
		chsp->error()= 0;
		chsp->uid()= 0;
//		if (llverbose_==1) fprintf(stderr,"<%d> %fnexthop=%x; prevhop=%x, lasthop=%x",chsp->next_hop_,chsp->prev_hop_,chsp->last_hop_);  
//	if (llverbose_==1) fprintf(stderr,"<%d> %f LL:test:recv pkt_type=%s uid=%d src=%d dst=%d\n", mac_->addr(), NOW ,packet_info.name(ch->ptype()),ch->uid_,Address::instance().get_nodeaddr(iph->saddr()),Address::instance().get_nodeaddr(iph->daddr()));

//		mhsp->set(mh->ftype(),mh->macDA(),mh->macSA());
//		mhsp->dh_da=mh->dh_sa;
//		mhsp->dh_sa=mh->dh_da;
//		mhsp->hdr_type_=mh->hdr_type_;
//		mhsp->ftype_=mh->ftype_;
		
		int dst_=ETHER_ADDR(dh->dh_sa);
		mac_->hdr_src(mhsp, mac_->addr());
		mac_->hdr_type(mhsp, ETHERTYPE_IP);
		mac_->hdr_dst(mhsp, dst_);
//		mac_->hdr_dst((char*) HDR_MAC(sp), chsp->next_hop());

			
		llhsp->lltype() = LL_ACK;
		llhsp->ackno_ = llh->seqno_+1;
		

		pktRx_ = sp->copy();	
		Scheduler& s = Scheduler::instance();
		s.schedule(downtarget_, sp, delay_);
		acSend_.stop();
		acSend_.start(0.5);//why 1.5 ?? rj
		if (llverbose_==1) fprintf(stderr,"<%d> %f LL: recvd a LL frag. sending LL ack num %d\n",
				mac_->addr(), NOW, llhsp->ackno_);

		//Packet::free(p);   
}

void LL::sendHandler()
{
	send_timer();
}

void LL::sendackHandler()
{
	send_acktimer();
}


void LL::send_timer()
{
	RetransmitDATA();
//	RetransmitACK();
}

void LL::send_acktimer()
{
	RetransmitACK();
}


void LL::RetransmitDATA()
{
	datacounter =datacounter + 1;
	assert(pktTx_);
 	hdr_ll* llh=HDR_LL(pktTx_);
	
	if (datacounter <4){	
	if (llverbose_==1) fprintf(stderr,"<%d> %f LL: wait for ack timed out. retxing ll_seqno=%d bopno=%d eopno=%d for %dth time\n",
			mac_->addr(), NOW, llh->seqno_, llh->bopno_, llh->eopno_, datacounter);
		Scheduler& s = Scheduler::instance();
		s.schedule(downtarget_, pktTx_->copy(), delay_);
		lhSend_.stop();
		lhSend_.start(0.5);
	}
	else{
	if (llverbose_==1) fprintf(stderr,"<%d> %f LL: retxed 5 times. ditched ll_seqno=%d bopno=%d eopno=%d\n", 
			mac_->addr(), NOW, llh->seqno_, llh->bopno_, llh->eopno_);
		datacounter=0;		//check this up...was good without it
		ackno_ ++;
		sendDownDATA();
	}
}

void LL::RetransmitACK()
{
	ackcounter =ackcounter +1;
	assert(pktRx_);
	hdr_ll *llh=HDR_LL(pktRx_);
	if (ackcounter < 4){
		if (llverbose_==1) fprintf(stderr,"<%d> %f LL: retx ack=%d for %dth time\n",
				mac_->addr(), NOW, llh->ackno_, ackcounter);
		Scheduler& s = Scheduler::instance();
		s.schedule(downtarget_,pktRx_->copy(),delay_);
		acSend_.stop();
		acSend_.start(0.5);
	}
	else{
		if (llverbose_==1) fprintf(stderr,"<%d> %f LL: retx ack 5 times. ditching\n", mac_->addr(), NOW );
	}
}

/* hack for the sendDown being called directly from snoop and satlink*/
void LL::sendDown(Packet* p)
{
	enqueDATA(p);
}