modified aodv.cc

the code of Ad Hoc On-demand Distance Vector (AODV) routing protocol for mobile ad hoc networks

/*
Copyright (c) 1997, 1998 Carnegie Mellon University.  All Rights
Reserved. 

Permission to use, copy, modify, and distribute this
software and its documentation is hereby granted (including for
commercial or for-profit use), provided that both the copyright notice and this permission notice appear in all copies of the software, derivative works, or modified versions, and any portions thereof, and that both notices appear in supporting documentation, and that credit is given to Carnegie Mellon University in all publications reporting on direct or indirect use of this code or its derivatives.

ALL CODE, SOFTWARE, PROTOCOLS, AND ARCHITECTURES DEVELOPED BY THE CMU
MONARCH PROJECT ARE EXPERIMENTAL AND ARE KNOWN TO HAVE BUGS, SOME OF
WHICH MAY HAVE SERIOUS CONSEQUENCES. CARNEGIE MELLON PROVIDES THIS
SOFTWARE OR OTHER INTELLECTUAL PROPERTY IN ITS ``AS IS'' CONDITION,
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY
BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE OR
INTELLECTUAL PROPERTY, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.

Carnegie Mellon encourages (but does not require) users of this
software or intellectual property to return any improvements or
extensions that they make, and to grant Carnegie Mellon the rights to redistribute these changes without encumbrance.

The AODV code developed by the CMU/MONARCH group was optimized and tuned by Samir Das and Mahesh Marina, University of Cincinnati. The work was partially done in Sun Microsystems. Modified for gratuitous replies by Anant Utgikar, 09/16/02.

*/

//#include <ip.h>

#include <aodv/aodv.h>
#include <aodv/aodv_packet.h>
#include <random.h>
#include <cmu-trace.h>
//#include <energy-model.h>

#define max(a,b)        ( (a) > (b) ? (a) : (b) )
#define CURRENT_TIME    Scheduler::instance().clock()

//#define DEBUG
//#define ERROR

#ifdef DEBUG
static int extra_route_reply = 0;
static int limit_route_request = 0;
static int route_request = 0;
#endif


/*
  TCL Hooks
*/


int hdr_aodv::offset_;
static class AODVHeaderClass : public PacketHeaderClass {
public:
        AODVHeaderClass() : PacketHeaderClass("PacketHeader/AODV",
                                              sizeof(hdr_all_aodv)) {
	  bind_offset(&hdr_aodv::offset_);
	} 
} class_rtProtoAODV_hdr;

static class AODVclass : public TclClass {
public:
        AODVclass() : TclClass("Agent/AODV") {}
        TclObject* create(int argc, const char*const* argv) {
          assert(argc == 5);
          //return (new AODV((nsaddr_t) atoi(argv[4])));
	  return (new AODV((nsaddr_t) Address::instance().str2addr(argv[4])));
        }
} class_rtProtoAODV;


int
AODV::command(int argc, const char*const* argv) {
  if(argc == 2) {
  Tcl& tcl = Tcl::instance();
    
    if(strncasecmp(argv[1], "id", 2) == 0) {
      tcl.resultf("%d", index);
      return TCL_OK;
    }
    
    if(strncasecmp(argv[1], "start", 2) == 0) {
      btimer.handle((Event*) 0);

#ifndef AODV_LINK_LAYER_DETECTION
      htimer.handle((Event*) 0);
      ntimer.handle((Event*) 0);
#endif // LINK LAYER DETECTION

      rtimer.handle((Event*) 0);
      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], "drop-target") == 0) {
    int stat = rqueue.command(argc,argv);
      if (stat != TCL_OK) return stat;
      return Agent::command(argc, argv);
    }
    else if(strcmp(argv[1], "if-queue") == 0) {
    ifqueue = (PriQueue*) TclObject::lookup(argv[2]);
      
      if(ifqueue == 0)
	return TCL_ERROR;
      return TCL_OK;
    }
  }
  return Agent::command(argc, argv);
}

/* 
   Constructor
*/

AODV::AODV(nsaddr_t id) : Agent(PT_AODV),
			  btimer(this), htimer(this), ntimer(this), 
			  rtimer(this), lrtimer(this), rqueue() {
 
                
  index = id;
  seqno = 2;
  bid = 1;

  LIST_INIT(&nbhead);
  LIST_INIT(&bihead);

  logtarget = 0;
  ifqueue = 0;
}

/*
  Timers
*/

void
BroadcastTimer::handle(Event*) {
  agent->id_purge();
  Scheduler::instance().schedule(this, &intr, BCAST_ID_SAVE);
}

void
HelloTimer::handle(Event*) {
   agent->sendHello();
   double interval = MinHelloInterval + 
                 ((MaxHelloInterval - MinHelloInterval) * Random::uniform());
   assert(interval >= 0);
   Scheduler::instance().schedule(this, &intr, interval);
}

void
NeighborTimer::handle(Event*) {
  agent->nb_purge();
  Scheduler::instance().schedule(this, &intr, HELLO_INTERVAL);
}

void
RouteCacheTimer::handle(Event*) {
  agent->rt_purge();
#define FREQUENCY 0.5 // sec
  Scheduler::instance().schedule(this, &intr, FREQUENCY);
}

void
LocalRepairTimer::handle(Event* p)  {  // SRD: 5/4/99
aodv_rt_entry *rt;
struct hdr_ip *ih = HDR_IP( (Packet *)p);

   /* you get here after the timeout in a local repair attempt */
   /*	fprintf(stderr, "%s\n", __FUNCTION__); */


    rt = agent->rtable.rt_lookup(ih->daddr());
	
    if (rt && rt->rt_flags != RTF_UP) {
    // route is yet to be repaired
    // I will be conservative and bring down the route
    // and send route errors upstream.
    /* The following assert fails, not sure why */
    /* assert (rt->rt_flags == RTF_IN_REPAIR); */
		
      //rt->rt_seqno++;
      agent->rt_down(rt);
      // send RERR
#ifdef DEBUG
      fprintf(stderr,"Node %d: Dst - %d, failed local repair\n",index, rt->rt_dst);
#endif      
    }
    Packet::free((Packet *)p);
}


/*
   Broadcast ID Management  Functions
*/


void
AODV::id_insert(nsaddr_t id, u_int32_t bid) {
BroadcastID *b = new BroadcastID(id, bid);

 assert(b);
 b->expire = CURRENT_TIME + BCAST_ID_SAVE;
 LIST_INSERT_HEAD(&bihead, b, link);
}

/* SRD */
bool
AODV::id_lookup(nsaddr_t id, u_int32_t bid) {
BroadcastID *b = bihead.lh_first;
 
 // Search the list for a match of source and bid
 for( ; b; b = b->link.le_next) {
   if ((b->src == id) && (b->id == bid))
     return true;     
 }
 return false;
}

void
AODV::id_purge() {
BroadcastID *b = bihead.lh_first;
BroadcastID *bn;
double now = CURRENT_TIME;

 for(; b; b = bn) {
   bn = b->link.le_next;
   if(b->expire <= now) {
     LIST_REMOVE(b,link);
     delete b;
   }
 }
}

/*
  Helper Functions
*/

double
AODV::PerHopTime(aodv_rt_entry *rt) {
int num_non_zero = 0, i;
double total_latency = 0.0;

 if (!rt)
   return ((double) NODE_TRAVERSAL_TIME );
	
 for (i=0; i < MAX_HISTORY; i++) {
   if (rt->rt_disc_latency[i] > 0.0) {
      num_non_zero++;
      total_latency += rt->rt_disc_latency[i];
   }
 }
 if (num_non_zero > 0)
   return(total_latency / (double) num_non_zero);
 else
   return((double) NODE_TRAVERSAL_TIME);

}

/*
  Link Failure Management Functions
*/

static void
aodv_rt_failed_callback(Packet *p, void *arg) {
  ((AODV*) arg)->rt_ll_failed(p);
}

/*
 * This routine is invoked when the link-layer reports a route failed.
 */
void
AODV::rt_ll_failed(Packet *p) {
struct hdr_cmn *ch = HDR_CMN(p);
struct hdr_ip *ih = HDR_IP(p);
aodv_rt_entry *rt;
nsaddr_t broken_nbr = ch->next_hop_;

#ifndef AODV_LINK_LAYER_DETECTION
 drop(p, DROP_RTR_MAC_CALLBACK);
#else 

 /*
  * Non-data packets and Broadcast Packets can be dropped.
  */
  if(! DATA_PACKET(ch->ptype()) ||
     (u_int32_t) ih->daddr() == IP_BROADCAST) {
    drop(p, DROP_RTR_MAC_CALLBACK);
    return;
  }
  log_link_broke(p);
	if((rt = rtable.rt_lookup(ih->daddr())) == 0) {
    drop(p, DROP_RTR_MAC_CALLBACK);
    return;
  }
  log_link_del(ch->next_hop_);

#ifdef AODV_LOCAL_REPAIR
  /* if the broken link is closer to the dest than source, 
     attempt a local repair. Otherwise, bring down the route. */


  if (ch->num_forwards() > rt->rt_hops) {
    local_rt_repair(rt, p); // local repair
    // retrieve all the packets in the ifq using this link,
    // queue the packets for which local repair is done, 
    return;
  }
  else	
#endif // LOCAL REPAIR	

  {
    drop(p, DROP_RTR_MAC_CALLBACK);
    // Do the same thing for other packets in the interface queue using the
    // broken link -Mahesh
while((p = ifqueue->filter(broken_nbr))) {
     drop(p, DROP_RTR_MAC_CALLBACK);
    }	
    nb_delete(broken_nbr);
  }

#endif // LINK LAYER DETECTION
}

void
AODV::handle_link_failure(nsaddr_t id) {
aodv_rt_entry *rt, *rtn;
Packet *rerr = Packet::alloc();
struct hdr_aodv_error *re = HDR_AODV_ERROR(rerr);

 re->DestCount = 0;
 for(rt = rtable.head(); rt; rt = rtn) {  // for each rt entry
   rtn = rt->rt_link.le_next; 
   if ((rt->rt_hops != INFINITY2) && (rt->rt_nexthop == id) ) {
     assert (rt->rt_flags == RTF_UP);
     assert((rt->rt_seqno%2) == 0);
     rt->rt_seqno++;
     re->unreachable_dst[re->DestCount] = rt->rt_dst;
     re->unreachable_dst_seqno[re->DestCount] = rt->rt_seqno;
#ifdef DEBUG
     fprintf(stderr, "%s(%f): %d\t(%d\t%u\t%d)\n", __FUNCTION__, CURRENT_TIME,
		     index, re->unreachable_dst[re->DestCount],
		     re->unreachable_dst_seqno[re->DestCount], rt->rt_nexthop);
#endif // DEBUG
     re->DestCount += 1;
     rt_down(rt);
   }
   // remove the lost neighbor from all the precursor lists
   rt->pc_delete(id);
 }   

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

void
AODV::local_rt_repair(aodv_rt_entry *rt, Packet *p) {
#ifdef DEBUG
  fprintf(stderr,"%s: Dst - %d\n", __FUNCTION__, rt->rt_dst); 
#endif  
  // Buffer the packet 
  rqueue.enque(p);

  // mark the route as under repair 
  rt->rt_flags = RTF_IN_REPAIR;

  sendRequest(rt->rt_dst);

  // set up a timer interrupt
  Scheduler::instance().schedule(&lrtimer, p->copy(), rt->rt_req_timeout);
}

void
AODV::rt_update(aodv_rt_entry *rt, u_int32_t seqnum, u_int16_t metric,
	       	nsaddr_t nexthop, double expire_time) {

     rt->rt_seqno = seqnum;
     rt->rt_hops = metric;
     rt->rt_flags = RTF_UP;
     rt->rt_nexthop = nexthop;
     rt->rt_expire = expire_time;
}

void
AODV::rt_down(aodv_rt_entry *rt) {
  /*
   *  Make sure that you don't "down" a route more than once.
   */

  if(rt->rt_flags == RTF_DOWN) {
    return;
  }

  // assert (rt->rt_seqno%2); // is the seqno odd?
  rt->rt_last_hop_count = rt->rt_hops;
  rt->rt_hops = INFINITY2;
  rt->rt_flags = RTF_DOWN;
  rt->rt_nexthop = 0;
  rt->rt_expire = 0;

} /* rt_down function */

/*
  Route Handling Functions
*/

void
AODV::rt_resolve(Packet *p) {
struct hdr_cmn *ch = HDR_CMN(p);
struct hdr_ip *ih = HDR_IP(p);
aodv_rt_entry *rt;

 /*
  *  Set the transmit failure callback.  That
  *  won't change.
  */
 ch->xmit_failure_ = aodv_rt_failed_callback;
 ch->xmit_failure_data_ = (void*) this;
	rt = rtable.rt_lookup(ih->daddr());
 if(rt == 0) {
	  rt = rtable.rt_add(ih->daddr());
 }

 /*
  * If the route is up, forward the packet 
  */
	
 if(rt->rt_flags == RTF_UP) {
   assert(rt->rt_hops != INFINITY2);
   forward(rt, p, NO_DELAY);
 }
 /*
  *  if I am the source of the packet, then do a Route Request.