dsragent.cc

动态路由协议dsr改进算法

}


int
DSRAgent::command(int argc, const char*const* argv)
{
  TclObject *obj;  

  if (argc == 2) 
    {
      if (strcasecmp(argv[1], "testinit") == 0)
	{
	  testinit();
	  return TCL_OK;
	}
      if (strcasecmp(argv[1], "reset") == 0)
	{
	  Terminate();
	  return Agent::command(argc, argv);
	}
      if (strcasecmp(argv[1], "check-cache") == 0)
	{
	  return route_cache->command(argc, argv);
	}
      if (strcasecmp(argv[1], "startdsr") == 0)
	{
	  if (ID(1,::IP) == net_id) 
	    { // log the configuration parameters of the dsragent
  trace("Sconfig %.5f tap: %s snoop: rts? %s errs? %s",
		    Scheduler::instance().clock(),
		    dsragent_use_tap ? "on" : "off",
		    dsragent_snoop_source_routes ? "on" : "off",
		    dsragent_snoop_forwarded_errors ? "on" : "off");
  trace("Sconfig %.5f salvage: %s !bd replies? %s",
		    Scheduler::instance().clock(),
		    dsragent_salvage_with_cache ? "on" : "off",
		    dsragent_dont_salvage_bad_replies ? "on" : "off");
  trace("Sconfig %.5f grat error: %s grat reply: %s",
	            Scheduler::instance().clock(),
	            dsragent_propagate_last_error ? "on" : "off",
	            dsragent_send_grat_replies ? "on" : "off");
  trace("Sconfig %.5f $reply for props: %s ring 0 search: %s",
	            Scheduler::instance().clock(),
	            dsragent_reply_from_cache_on_propagating ? "on" : "off",
	            dsragent_ring_zero_search ? "on" : "off");
	    }
	  // cheap source of jitter
	  send_buf_timer.sched(BUFFER_CHECK 
			       + BUFFER_CHECK * Random::uniform(1.0));	  
          return route_cache->command(argc,argv);
	}
    }
  else if(argc == 3) 
    {
      if (strcasecmp(argv[1], "addr") == 0) 
	{
	  int temp;
	  temp = Address::instance().str2addr(argv[2]);
	 net_id = ID(temp, ::IP);
	 flow_table.setNetAddr(net_id.addr);
	 route_cache->net_id = net_id;
	 return TCL_OK;
	} 
      else if(strcasecmp(argv[1], "mac-addr") == 0) 
	{
	  MAC_id = ID(atoi(argv[2]), ::MAC);
	  route_cache->MAC_id = MAC_id;
	  return TCL_OK;
	}
      else if(strcasecmp(argv[1], "rt_rq_max_period") == 0)
        {
          rt_rq_max_period = strtod(argv[2],NULL);
          return TCL_OK;
        }
      else if(strcasecmp(argv[1], "rt_rq_period") == 0)
        {
          rt_rq_period = strtod(argv[2],NULL);
          return TCL_OK;
        }
      else if(strcasecmp(argv[1], "send_timeout") == 0)
        {
          send_timeout = strtod(argv[2],NULL);
          return TCL_OK;
        }

      
      if( (obj = TclObject::lookup(argv[2])) == 0) 
	{
	  fprintf(stderr, "DSRAgent: %s lookup of %s failed\n", argv[1],
		  argv[2]);
	  return TCL_ERROR;
	}

      if (strcasecmp(argv[1], "log-target") == 0)  {
	      logtarget = (Trace*) obj;
	      return route_cache->command(argc, argv);
      }
      else if (strcasecmp(argv[1], "tracetarget") == 0 )
       	{
	  logtarget = (Trace*) obj;
	  return route_cache->command(argc, argv);
	}
      else if (strcasecmp(argv[1], "install-tap") == 0)  
	{
	  mac_ = (Mac*) obj;
	  mac_->installTap(this);
	  return TCL_OK;
	}
      else if (strcasecmp(argv[1], "node") == 0)
	{
	  node_ = (MobileNode *) obj;
	  return TCL_OK;
	}
      else if (strcasecmp (argv[1], "port-dmux") == 0) 
	{
	  port_dmux_ = (NsObject *) obj;
	  return TCL_OK;
	}
    }
  else if (argc == 4)
    {
      if (strcasecmp(argv[1], "add-ll") == 0) 
	{
	  if( (obj = TclObject::lookup(argv[2])) == 0) {
	    fprintf(stderr, "DSRAgent: %s lookup of %s failed\n", argv[1],
		    argv[2]);
	    return TCL_ERROR;
	  }
	  ll = (NsObject*) obj;
	  if( (obj = TclObject::lookup(argv[3])) == 0) {
	    fprintf(stderr, "DSRAgent: %s lookup of %s failed\n", argv[1],
		    argv[3]);
	    return TCL_ERROR;
	  }
	  ifq = (CMUPriQueue *) obj;
	  return TCL_OK;

	}


    }
  return Agent::command(argc, argv);
}

void
DSRAgent::sendOutBCastPkt(Packet *p)
{
  hdr_cmn *cmh =  hdr_cmn::access(p);
  if(cmh->direction() == hdr_cmn::UP)
    cmh->direction() = hdr_cmn::DOWN;
  // no jitter required
  Scheduler::instance().schedule(ll, p, 0.0);
}



void
DSRAgent::recv(Packet* packet, Handler*)
  /* handle packets with a MAC destination address of this host, or
     the MAC broadcast addr */
{
  hdr_sr *srh =  hdr_sr::access(packet);
  hdr_ip *iph =  hdr_ip::access(packet);
  hdr_cmn *cmh =  hdr_cmn::access(packet);

  // special process for GAF
  if (cmh->ptype() == PT_GAF) {
    if (iph->daddr() == (int)IP_BROADCAST) { 
      if(cmh->direction() == hdr_cmn::UP)
	cmh->direction() = hdr_cmn::DOWN;
      Scheduler::instance().schedule(ll,packet,0);
      return;
    } else {
      target_->recv(packet, (Handler*)0);
      return;	  
    }
  }

  assert(cmh->size() >= 0);

  SRPacket p(packet, srh);
  //p.dest = ID(iph->dst(),::IP);
  //p.src = ID(iph->src(),::IP);
  p.dest = ID((Address::instance().get_nodeaddr(iph->daddr())),::IP);
  p.src = ID((Address::instance().get_nodeaddr(iph->saddr())),::IP);

  assert(logtarget != 0);

  if (srh->valid() != 1) {
    unsigned int dst = cmh->next_hop();
    if (dst == IP_BROADCAST) {
      // extensions for mobileIP --Padma, 04/99.
      // Brdcast pkt - treat differently
      if (p.src == net_id)
	// I have originated this pkt
	sendOutBCastPkt(packet);
      else 
	//hand it over to port-dmux
	port_dmux_->recv(packet, (Handler*)0);
      
    } else {
      // this must be an outgoing packet, it doesn't have a SR header on it
      
      srh->init();		 // give packet an SR header now
      cmh->size() += IP_HDR_LEN; // add on IP header size
      if (verbose)
	trace("S %.9f _%s_ originating %s -> %s",
	      Scheduler::instance().clock(), net_id.dump(), p.src.dump(), 
	      p.dest.dump());
      handlePktWithoutSR(p, false);
      goto done;
    }
  }
  else if (srh->valid() == 1) 
    {
      if (p.dest == net_id || p.dest == IP_broadcast)
	{ // this packet is intended for us
	  handlePacketReceipt(p);
	  goto done;
	}
      
      // should we check to see if it's an error packet we're handling
      // and if so call processBrokenRouteError to snoop
      if (dsragent_snoop_forwarded_errors && srh->route_error())
	{
	  processBrokenRouteError(p);
	}

      if (srh->route_request())
	{ // propagate a route_request that's not for us
	  handleRouteRequest(p);
	}
      else
	{ // we're not the intended final recpt, but we're a hop
	  handleForwarding(p);
	}
    }
  else {
    // some invalid pkt has reached here
    fprintf(stderr,"dsragent: Error-received Invalid pkt!\n");
    Packet::free(p.pkt);
    p.pkt =0; // drop silently
  }

 done:
  assert(p.pkt == 0);
  
  p.pkt = 0;
  return;
}


/*===========================================================================
  handlers for each class of packet
---------------------------------------------------------------------------*/
void
DSRAgent::handlePktWithoutSR(SRPacket& p, bool retry)
  /* obtain a source route to p's destination and send it off.
     this should be a retry if the packet is already in the sendbuffer */
{
  assert(HDR_SR (p.pkt)->valid());

  if (p.dest == net_id)
    { // it doesn't need a source route, 'cause it's for us
      handlePacketReceipt(p);
      return;
    }

  // Extensions for wired cum wireless simulation mode
  //if pkt dst outside my subnet, route to base_stn

  ID dest;
  if (diff_subnet(p.dest,net_id)) {
  dest = ID(node_->base_stn(),::IP);
  p.dest = dest;
  }

  if (route_cache->findRoute(p.dest, p.route, 1))
    { // we've got a route...
      if (verbose)
	trace("S$hit %.5f _%s_ %s -> %s %s",
	      Scheduler::instance().clock(), net_id.dump(),
	      p.src.dump(), p.dest.dump(), p.route.dump());      
      sendOutPacketWithRoute(p, true);
      return;
    } // end if we have a route
  else
    { // we don't have a route...
      if (verbose) 
	trace("S$miss %.5f _%s_ %s -> %s", 
	      Scheduler::instance().clock(), net_id.dump(), 
	      net_id.dump(), p.dest.dump());

      getRouteForPacket(p, retry);
      return;
    } // end of we don't have a route
}

void
DSRAgent::handlePacketReceipt(SRPacket& p)
  /* Handle a packet destined to us */
{
  hdr_cmn *cmh =  hdr_cmn::access(p.pkt);
  hdr_sr *srh =  hdr_sr::access(p.pkt);

  if (srh->route_reply())
    { // we got a route_reply piggybacked on a route_request
      // accept the new source route before we do anything else
      // (we'll send off any packet's we have queued and waiting)
      acceptRouteReply(p);
    }
  
  if (srh->route_request())
    {
      if (dsragent_reply_only_to_first_rtreq  && ignoreRouteRequestp(p)) 
	{ //we only respond to the first route request
	  // we receive from a host 
	  Packet::free(p.pkt);     // drop silently
	  p.pkt = 0;
	  return;
	}
      else
	{ // we're going to process this request now, so record the req_num
	  request_table.insert(p.src, p.src, srh->rtreq_seq());
	  returnSrcRouteToRequestor(p);
	}
    }

  if (srh->route_error())
    { // register the dead route      
      processBrokenRouteError(p);
    }

  if (srh->flow_unknown())
    processUnknownFlowError(p, false);

  if (srh->flow_default_unknown())
    processUnknownFlowError(p, true);

  /* give the data in the packet to our higher layer (our port dmuxer, most 
   likely) */
  //handPktToDmux(p);
  assert(p.dest == net_id || p.dest == MAC_id);
  
#if 0
  if (iph->dport() == 255) {
    int mask = Address::instance().portmask();
    int shift = Address::instance().portshift();  
    iph->daddr() = ((iph->dport() & mask) << shift) | ((~(mask) << shift) & iph->dst());
  }
#endif
  
  cmh->size() -= srh->size();	// cut off the SR header 4/7/99 -dam
  srh->valid() = 0;
  cmh->size() -= IP_HDR_LEN;    // cut off IP header size 4/7/99 -dam
  target_->recv(p.pkt, (Handler*)0);
  p.pkt = 0;

}


void
DSRAgent::handleDefaultForwarding(SRPacket &p) {
  hdr_ip *iph = hdr_ip::access(p.pkt);
  u_int16_t flowid;
  int       flowidx;

  if (!flow_table.defaultFlow(p.src.addr, p.dest.addr, flowid)) {
    sendUnknownFlow(p, true);
    assert(p.pkt == 0);
    return;
  }

  if ((flowidx = flow_table.find(p.src.addr, p.dest.addr, flowid)) == -1) {
    sendUnknownFlow(p, false, flowid);
    assert(p.pkt == 0);
    return;
  }

  if (iph->ttl() != flow_table[flowidx].expectedTTL) {
    sendUnknownFlow(p, true);
    assert(p.pkt == 0);
    return;
  }

  // XXX should also check prevhop

  handleFlowForwarding(p, flowidx);
}

void
DSRAgent::handleFlowForwarding(SRPacket &p, int flowidx) {
  hdr_sr *srh = hdr_sr::access(p.pkt);
  hdr_ip *iph = hdr_ip::access(p.pkt);
  hdr_cmn *cmnh =  hdr_cmn::access(p.pkt);
  int amt;

  assert(flowidx >= 0);
  assert(!srh->num_addrs());

  cmnh->next_hop() = flow_table[flowidx].nextHop;
  cmnh->addr_type() = ::IP;

  cmnh->xmit_failure_ = XmitFlowFailureCallback;
  cmnh->xmit_failure_data_ = (void *) this;

  // make sure we aren't cycling packets
  //assert(p.pkt->incoming == 0); // this is an outgoing packet
  assert(cmnh->direction() == hdr_cmn::UP);

  if (!iph->ttl()--) {
    drop(p.pkt, DROP_RTR_TTL);
    p.pkt = 0;
    return;
  }

  trace("SFf %.9f _%s_ %d [%s -> %s] %d to %d", 
	Scheduler::instance().clock(), net_id.dump(), cmnh->uid(),
	p.src.dump(), p.dest.dump(), flow_table[flowidx].flowId,
	flow_table[flowidx].nextHop);

  // XXX ych 5/8/01 ARS also should check previous hop
  if (!srh->salvaged() && 
      (amt = ars_table.findAndClear(cmnh->uid(), flow_table[flowidx].flowId)) &&