mflood.cc

《NS与网络模拟》一书的源代码

#include <mflood/mflood.h>
#include <mflood/mflood-packet.h>
//#include <mflood.h>
#include <random.h>
#include <cmu-trace.h>
//#include <iostream>

// New packet type
int hdr_mflood::offset_;
static class MFloodHeaderClass : public PacketHeaderClass {
public:
	MFloodHeaderClass() : PacketHeaderClass("PacketHeader/MFlood", 
					      sizeof(hdr_mflood)) {
		bind_offset(&hdr_mflood::offset_);
	}
} class_mfloodhdr;

// TCL Hooks
static class MFloodclass : public TclClass {
public:
	MFloodclass() : TclClass("Agent/MFlood") {}
	TclObject* create(int argc, const char*const* argv) {
		assert(argc == 5);
		return (new MFlood((nsaddr_t) atoi(argv[4])));	// PBO agrv[4] is index_}
	}
} class_rtProtoMFlood;


int
MFlood::command(int argc, const char*const* argv) {
	Tcl& tcl = Tcl::instance();
	if(argc == 2) {		
		if(strncasecmp(argv[1], "id", 2) == 0) {
			tcl.resultf("%d", index_);
			return TCL_OK;
		}
		else if (strcmp(argv[1], "uptarget") == 0) {
			if (uptarget_ != 0)
				tcl.result(uptarget_->name());
			return (TCL_OK);
		}
	} else if(argc == 3) {
		if(strcmp(argv[1], "index_") == 0) {
			index_ = atoi(argv[2]);
			return TCL_OK;
		} else if(strcmp(argv[1], "log-target") == 0 || strcmp(argv[1], "tracetarget") == 0) {
			logtarget = (Trace*) TclObject::lookup(argv[2]);
			if(logtarget == 0) return TCL_ERROR;
			return TCL_OK;
		}
		else if (strcmp(argv[1], "uptarget") == 0) {
			if (*argv[2] == '0') {
				target_ = 0;
				return (TCL_OK);
			}
			uptarget_ = (NsObject*)TclObject::lookup(argv[2]);
			if (uptarget_ == 0) {
				tcl.resultf("no such object %s", argv[2]);
				return (TCL_ERROR);
			}
			return (TCL_OK);
		}		
	}
	return Agent::command(argc, argv);
}

MFlood::MFlood(nsaddr_t id) : Agent(PT_MFLOOD) {
	index_ = id;
	logtarget = 0;
	myseq_ = 0;
}


// Route Handling Functions
void
MFlood::rt_resolve(Packet *p) {
	struct hdr_cmn *ch = HDR_CMN(p);
	struct hdr_ip *ih = HDR_IP(p);
	struct hdr_mflood *fh = HDR_MFLOOD(p);
	MFlood_RTEntry* rt;

	rt = rtable_.rt_lookup(ih->saddr());
	if(rt == NULL) {
		rt = new MFlood_RTEntry(ih->saddr(), fh->seq_);

		LIST_INSERT_HEAD(&rtable_.rthead,rt,rt_link);		
	
		//printf("%.8f %d,no uptarget,\n",NOW,index_);
		forward(rt,p,FORWARD_DELAY);
		
//printf("%.8f %d,no rt,so forward.rt_seq:%d,pkt seq:%d\n",NOW,index_,rt->max_seqno,fh->seq_);
rtable_.rt_print();		
		
	}
//	else if(rt->seq_ < fh->seq_ )
	else if(rt->isNewSeq(fh->seq_) )
	{
		//printf("%.8f %d,no uptarget,\n",NOW,index_);
		forward(rt, p, FORWARD_DELAY);
		
//		rt->seq_ = fh->seq_;
		rt->addSeq(fh->seq_);

//printf("%.8f %d,rt seq too small,so forward,rt_seq:%d,packet seq:%d.\n",NOW,index_,rt->max_seqno,fh->seq_);	
rtable_.rt_print();		
	}
	else
	{
		drop(p, "LOWSEQ");
	}
}


// Packet Reception Routines
void
MFlood::recv(Packet *p, Handler*) {
	struct hdr_cmn *ch = HDR_CMN(p);
	struct hdr_ip *ih = HDR_IP(p);
	struct hdr_mflood *fh = HDR_MFLOOD(p);
	assert(initialized());

	if((ih->saddr() == index_) && (ch->num_forwards() == 0)) {	// Must be a packet I'm originating...		
		ch->size() += IP_HDR_LEN;		// Add the IP Header
		ih->ttl_ = NETWORK_DIAMETER;
		fh->seq_ = myseq_++;			
		forward((MFlood_RTEntry*)1,p,0);		
		return;
	} else if(ih->saddr() == index_) {	// I received a packet that I sent.  Probably a routing loop.
		drop(p, DROP_RTR_ROUTE_LOOP);
		return;
	} else {		// Packet I'm forwarding...
		if(--ih->ttl_ == 0) {	// Check the TTL.  If it is zero, then discard.
			drop(p, DROP_RTR_TTL);
	 		return;
		}
	}

	rt_resolve(p);
}


// Packet Transmission Routines
void
MFlood::forward(MFlood_RTEntry* rt, Packet *p, double delay) {
	struct hdr_cmn *ch = HDR_CMN(p);
	struct hdr_ip *ih = HDR_IP(p);

	assert(ih->ttl_ > 0);
	assert(rt != 0);
//	assert(rt->rt_flags == RTF_UP);
	ch->next_hop_ = -1;	//Broadcast address
	ch->addr_type() = NS_AF_INET;
	ch->direction() = hdr_cmn::DOWN;       //important: change the packet's direction
	if(delay > 0.0) {
 		Scheduler::instance().schedule(target_, p, Random::uniform(delay*2));
	} else {		// Not a broadcast packet, no delay, send immediately
 		Scheduler::instance().schedule(target_, p, 0.);
	}
}