caodv.cc

这是我毕业设计做的无线多路径路由

   // I don't know how to forward .. drop the reply. 
#ifdef DEBUG
     fprintf(stderr, "%s: dropping Route Reply\n", __FUNCTION__);
#endif // DEBUG
     drop(p, DROP_RTR_NO_ROUTE);
   }
 }
}


void
CAODV::recvError(Packet *p) {
struct hdr_ip *ih = HDR_IP(p);
struct hdr_caodv_error *re = HDR_CAODV_ERROR(p);
caodv_rt_entry *rt;
u_int8_t i;
Packet *rerr = Packet::alloc();
struct hdr_caodv_error *nre = HDR_CAODV_ERROR(rerr);

 nre->DestCount = 0;

 for (i=0; i<re->DestCount; i++) {
 // For each unreachable destination
   rt = rtable.rt_lookup(re->unreachable_dst[i]);
   if ( rt && (rt->rt_hops != INFINITY2) &&
	(rt->rt_nexthop == ih->saddr()) &&
     	(rt->rt_seqno <= re->unreachable_dst_seqno[i]) ) {
	assert(rt->rt_flags == RTF_UP);
	assert((rt->rt_seqno%2) == 0); // is the seqno even?
#ifdef DEBUG
     fprintf(stderr, "%s(%f): %d\t(%d\t%u\t%d)\t(%d\t%u\t%d)\n", __FUNCTION__,CURRENT_TIME,
		     index, rt->rt_dst, rt->rt_seqno, rt->rt_nexthop,
		     re->unreachable_dst[i],re->unreachable_dst_seqno[i],
	             ih->saddr());
#endif // DEBUG
     	rt->rt_seqno = re->unreachable_dst_seqno[i];
     	rt_down(rt);

   // Not sure whether this is the right thing to do
   Packet *pkt;
	while((pkt = ifqueue->filter(ih->saddr()))) {
        	drop(pkt, DROP_RTR_MAC_CALLBACK);
     	}

     // if precursor list non-empty add to RERR and delete the precursor list
     	if (!rt->pc_empty()) {
     		nre->unreachable_dst[nre->DestCount] = rt->rt_dst;
     		nre->unreachable_dst_seqno[nre->DestCount] = rt->rt_seqno;
     		nre->DestCount += 1;
		rt->pc_delete();
     	}
   }
 } 

 if (nre->DestCount > 0) {
#ifdef DEBUG
   fprintf(stderr, "%s(%f): %d\t sending RERR...\n", __FUNCTION__, CURRENT_TIME, index);
#endif // DEBUG
   sendError(rerr);
 }
 else {
   Packet::free(rerr);
 }

 Packet::free(p);
}


/*
   Packet Transmission Routines
*/

void
CAODV::forward(caodv_rt_entry *rt, Packet *p, double delay) {
struct hdr_cmn *ch = HDR_CMN(p);
struct hdr_ip *ih = HDR_IP(p);

 if(ih->ttl_ == 0) {

#ifdef DEBUG
  fprintf(stderr, "%s: calling drop()\n", __PRETTY_FUNCTION__);
#endif // DEBUG
 
  drop(p, DROP_RTR_TTL);
  return;
 }

 if (ch->ptype() != PT_CAODV && ch->direction() == hdr_cmn::UP &&
	((u_int32_t)ih->daddr() == IP_BROADCAST)
		|| (ih->daddr() == here_.addr_)) {
	dmux_->recv(p,0);
	return;
 }

 if (rt) {
   assert(rt->rt_flags == RTF_UP);
   rt->rt_expire = CURRENT_TIME + ACTIVE_ROUTE_TIMEOUT;
   ch->next_hop_ = rt->rt_nexthop;
   ch->addr_type() = NS_AF_INET;
   ch->direction() = hdr_cmn::DOWN;       //important: change the packet's direction
 }
 else { // if it is a broadcast packet
   // assert(ch->ptype() == PT_CAODV); // maybe a diff pkt type like gaf
   assert(ih->daddr() == (nsaddr_t) IP_BROADCAST);
   ch->addr_type() = NS_AF_NONE;
   ch->direction() = hdr_cmn::DOWN;       //important: change the packet's direction
 }

if (ih->daddr() == (nsaddr_t) IP_BROADCAST) {
 // If it is a broadcast packet
   assert(rt == 0);
   /*
    *  Jitter the sending of broadcast packets by 10ms
    */
   Scheduler::instance().schedule(target_, p,
      				   0.01 * Random::uniform());
 }
 else { // Not a broadcast packet 
   if(delay > 0.0) {
     Scheduler::instance().schedule(target_, p, delay);
   }
   else {
   // Not a broadcast packet, no delay, send immediately
     Scheduler::instance().schedule(target_, p, 0.);
   }
 }

}


void
CAODV::sendRequest(nsaddr_t dst) {
// Allocate a RREQ packet 
Packet *p = Packet::alloc();
struct hdr_cmn *ch = HDR_CMN(p);
struct hdr_ip *ih = HDR_IP(p);
struct hdr_caodv_request *rq = HDR_CAODV_REQUEST(p);
caodv_rt_entry *rt = rtable.rt_lookup(dst);

 assert(rt);

 /*
  *  Rate limit sending of Route Requests. We are very conservative
  *  about sending out route requests. 
  */

 if (rt->rt_flags == RTF_UP) {
   assert(rt->rt_hops != INFINITY2);
   Packet::free((Packet *)p);
   return;
 }

 if (rt->rt_req_timeout > CURRENT_TIME) {
   Packet::free((Packet *)p);
   return;
 }

 // rt_req_cnt is the no. of times we did network-wide broadcast
 // RREQ_RETRIES is the maximum number we will allow before 
 // going to a long timeout.

 if (rt->rt_req_cnt > RREQ_RETRIES) {
   rt->rt_req_timeout = CURRENT_TIME + MAX_RREQ_TIMEOUT;
   rt->rt_req_cnt = 0;
 Packet *buf_pkt;
   while ((buf_pkt = rqueue.deque(rt->rt_dst))) {
       drop(buf_pkt, DROP_RTR_NO_ROUTE);
   }
   Packet::free((Packet *)p);
   return;
 }

#ifdef DEBUG
   fprintf(stderr, "(%2d) - %2d sending Route Request, dst: %d\n",
                    ++route_request, index, rt->rt_dst);
#endif // DEBUG

 // Determine the TTL to be used this time. 
 // Dynamic TTL evaluation - SRD

 rt->rt_req_last_ttl = max(rt->rt_req_last_ttl,rt->rt_last_hop_count);

 if (0 == rt->rt_req_last_ttl) {
 // first time query broadcast
   ih->ttl_ = TTL_START;
 }
 else {
 // Expanding ring search.
   if (rt->rt_req_last_ttl < TTL_THRESHOLD)
     ih->ttl_ = rt->rt_req_last_ttl + TTL_INCREMENT;
   else {
   // network-wide broadcast
     ih->ttl_ = NETWORK_DIAMETER;
     rt->rt_req_cnt += 1;
   }
 }

 // remember the TTL used  for the next time
 rt->rt_req_last_ttl = ih->ttl_;

 // PerHopTime is the roundtrip time per hop for route requests.
 // The factor 2.0 is just to be safe .. SRD 5/22/99
 // Also note that we are making timeouts to be larger if we have 
 // done network wide broadcast before. 

 rt->rt_req_timeout = 2.0 * (double) ih->ttl_ * PerHopTime(rt); 
 if (rt->rt_req_cnt > 0)
   rt->rt_req_timeout *= rt->rt_req_cnt;
 rt->rt_req_timeout += CURRENT_TIME;

 // Don't let the timeout to be too large, however .. SRD 6/8/99
 if (rt->rt_req_timeout > CURRENT_TIME + MAX_RREQ_TIMEOUT)
   rt->rt_req_timeout = CURRENT_TIME + MAX_RREQ_TIMEOUT;
 rt->rt_expire = 0;

#ifdef DEBUG
 fprintf(stderr, "(%2d) - %2d sending Route Request, dst: %d, tout %f ms\n",
	         ++route_request, 
		 index, rt->rt_dst, 
		 rt->rt_req_timeout - CURRENT_TIME);
#endif	// DEBUG
	

 // Fill out the RREQ packet 
 // ch->uid() = 0;
 ch->ptype() = PT_CAODV;
 ch->size() = IP_HDR_LEN + rq->size();
 ch->iface() = -2;
 ch->error() = 0;
 ch->addr_type() = NS_AF_NONE;
 ch->prev_hop_ = index;          // CAODV hack

 ih->saddr() = index;
 ih->daddr() = IP_BROADCAST;
 ih->sport() = RT_PORT;
 ih->dport() = RT_PORT;

 // Fill up some more fields. 
 rq->rq_type = CAODVTYPE_RREQ;
 rq->rq_hop_count = 1;
 rq->rq_bcast_id = bid++;
 rq->rq_dst = dst;
 rq->rq_dst_seqno = (rt ? rt->rt_seqno : 0);
 rq->rq_src = index;
 seqno += 2;
 assert ((seqno%2) == 0);
 rq->rq_src_seqno = seqno;
 rq->rq_timestamp = CURRENT_TIME;

 Scheduler::instance().schedule(target_, p, 0.);

}

void
CAODV::sendReply(nsaddr_t ipdst, u_int32_t hop_count, nsaddr_t rpdst,
                u_int32_t rpseq, u_int32_t lifetime, double timestamp) {
Packet *p = Packet::alloc();
struct hdr_cmn *ch = HDR_CMN(p);
struct hdr_ip *ih = HDR_IP(p);
struct hdr_caodv_reply *rp = HDR_CAODV_REPLY(p);
caodv_rt_entry *rt = rtable.rt_lookup(ipdst);

#ifdef DEBUG
fprintf(stderr, "sending Reply from %d at %.2f\n", index, Scheduler::instance().clock());
#endif // DEBUG
 assert(rt);

 rp->rp_type = CAODVTYPE_RREP;
 //rp->rp_flags = 0x00;
 rp->rp_hop_count = hop_count;
 rp->rp_dst = rpdst;
 rp->rp_dst_seqno = rpseq;
 rp->rp_src = index;
 rp->rp_lifetime = lifetime;
 rp->rp_timestamp = timestamp;
   
 // ch->uid() = 0;
 ch->ptype() = PT_CAODV;
 ch->size() = IP_HDR_LEN + rp->size();
 ch->iface() = -2;
 ch->error() = 0;
 ch->addr_type() = NS_AF_INET;
 ch->next_hop_ = rt->rt_nexthop;
 ch->prev_hop_ = index;          // CAODV hack
 ch->direction() = hdr_cmn::DOWN;

 ih->saddr() = index;
 ih->daddr() = ipdst;
 ih->sport() = RT_PORT;
 ih->dport() = RT_PORT;
 ih->ttl_ = NETWORK_DIAMETER;

 Scheduler::instance().schedule(target_, p, 0.);

}

void
CAODV::sendError(Packet *p, bool jitter) {
struct hdr_cmn *ch = HDR_CMN(p);
struct hdr_ip *ih = HDR_IP(p);
struct hdr_caodv_error *re = HDR_CAODV_ERROR(p);
    
#ifdef ERROR
fprintf(stderr, "sending Error from %d at %.2f\n", index, Scheduler::instance().clock());
#endif // DEBUG

 re->re_type = CAODVTYPE_RERR;
 //re->reserved[0] = 0x00; re->reserved[1] = 0x00;
 // DestCount and list of unreachable destinations are already filled

 // ch->uid() = 0;
 ch->ptype() = PT_CAODV;
 ch->size() = IP_HDR_LEN + re->size();
 ch->iface() = -2;
 ch->error() = 0;
 ch->addr_type() = NS_AF_NONE;
 ch->next_hop_ = 0;
 ch->prev_hop_ = index;          // CAODV hack
 ch->direction() = hdr_cmn::DOWN;       //important: change the packet's direction

 ih->saddr() = index;
 ih->daddr() = IP_BROADCAST;
 ih->sport() = RT_PORT;
 ih->dport() = RT_PORT;
 ih->ttl_ = 1;

 // Do we need any jitter? Yes
 if (jitter)
 	Scheduler::instance().schedule(target_, p, 0.01*Random::uniform());
 else
 	Scheduler::instance().schedule(target_, p, 0.0);

}


/*
   Neighbor Management Functions
*/

void
CAODV::sendHello() {
Packet *p = Packet::alloc();
struct hdr_cmn *ch = HDR_CMN(p);
struct hdr_ip *ih = HDR_IP(p);
struct hdr_caodv_reply *rh = HDR_CAODV_REPLY(p);

#ifdef DEBUG
fprintf(stderr, "sending Hello from %d at %.2f\n", index, Scheduler::instance().clock());
#endif // DEBUG

 rh->rp_type = CAODVTYPE_HELLO;
 //rh->rp_flags = 0x00;
 rh->rp_hop_count = 1;
 rh->rp_dst = index;
 rh->rp_dst_seqno = seqno;
 rh->rp_lifetime = (1 + ALLOWED_HELLO_LOSS) * HELLO_INTERVAL;

 // ch->uid() = 0;
 ch->ptype() = PT_CAODV;
 ch->size() = IP_HDR_LEN + rh->size();
 ch->iface() = -2;
 ch->error() = 0;
 ch->addr_type() = NS_AF_NONE;
 ch->prev_hop_ = index;          // CAODV hack

 ih->saddr() = index;
 ih->daddr() = IP_BROADCAST;
 ih->sport() = RT_PORT;
 ih->dport() = RT_PORT;
 ih->ttl_ = 1;

 Scheduler::instance().schedule(target_, p, 0.0);
}


void
CAODV::recvHello(Packet *p) {
//struct hdr_ip *ih = HDR_IP(p);
struct hdr_caodv_reply *rp = HDR_CAODV_REPLY(p);
CAODV_Neighbor *nb;

 nb = nb_lookup(rp->rp_dst);
 if(nb == 0) {
   nb_insert(rp->rp_dst);
 }
 else {
   nb->nb_expire = CURRENT_TIME +
                   (1.5 * ALLOWED_HELLO_LOSS * HELLO_INTERVAL);
 }

 Packet::free(p);
}

void
CAODV::nb_insert(nsaddr_t id) {
CAODV_Neighbor *nb = new CAODV_Neighbor(id);

 assert(nb);
 nb->nb_expire = CURRENT_TIME +
                (1.5 * ALLOWED_HELLO_LOSS * HELLO_INTERVAL);
 LIST_INSERT_HEAD(&nbhead, nb, nb_link);
 seqno += 2;             // set of neighbors changed
 assert ((seqno%2) == 0);
}


CAODV_Neighbor*
CAODV::nb_lookup(nsaddr_t id) {
CAODV_Neighbor *nb = nbhead.lh_first;

 for(; nb; nb = nb->nb_link.le_next) {
   if(nb->nb_addr == id) break;
 }
 return nb;
}


/*
 * Called when we receive *explicit* notification that a Neighbor
 * is no longer reachable.
 */
void
CAODV::nb_delete(nsaddr_t id) {
CAODV_Neighbor *nb = nbhead.lh_first;

 log_link_del(id);
 seqno += 2;     // Set of neighbors changed
 assert ((seqno%2) == 0);

 for(; nb; nb = nb->nb_link.le_next) {
   if(nb->nb_addr == id) {
     LIST_REMOVE(nb,nb_link);
     delete nb;
     break;
   }
 }

 handle_link_failure(id);

}


/*
 * Purges all timed-out Neighbor Entries - runs every
 * HELLO_INTERVAL * 1.5 seconds.
 */
void
CAODV::nb_purge() {
CAODV_Neighbor *nb = nbhead.lh_first;
CAODV_Neighbor *nbn;
double now = CURRENT_TIME;

 for(; nb; nb = nbn) {
   nbn = nb->nb_link.le_next;
   if(nb->nb_expire <= now) {
     nb_delete(nb->nb_addr);
   }
 }

}