localrepair.c

ucsb大学开发的aodv路由协议代码。

/*
 * Copyright (C) 2001, University of California, Santa Barbara
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 * 
 * Other copyrights might apply to parts of this software and are so
 * noted when applicable.
 */

/*
 * Parts of this program has been derived from PIM sparse-mode pimd.
 * The pimd program is covered by the license in the accompanying file
 * named "LICENSE.pimd".
 *  
 * The pimd program is COPYRIGHT 1998 by University of Southern California.
 *
 */

#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/types.h>

#include "aodvConst.h"
#include "aodvPktInfo.h"
#include "callout.h"
#include "const.h"
#include "debug.h"
#include "inet.h"
#include "rerr.h"
#include "routingTable.h"
#include "rreq.h"
#include "sendDatagram.h"

struct LREntry {
  u_int32_t dest;
  struct LREntry *next;
};

static struct LREntry *firstLREntry = NULL;

int inLRList(u_int32_t dest){
  struct LREntry *entry = NULL;
  trace(TRACE_LOCAL_REPAIR,"inLRList");
  for ( entry = firstLREntry
	  ; entry != NULL
	  ; entry = entry->next){
    if(entry->dest == dest){
      return TRUE;
    }
  }
  return FALSE;
}


static void addToLRList(u_int32_t dest){
  struct LREntry *entry = NULL;
  struct LREntry *first = NULL;
  trace(TRACE_LOCAL_REPAIR,"addToList");
  if(inLRList(dest) == FALSE) {
    entry = (struct LREntry *)malloc(sizeof(struct LREntry));
    if(entry == NULL){
      log(LOG_ERR,TRUE,"unable to allocate memory, LREntry");
    }
    entry->dest=dest;
    first=firstLREntry;
    firstLREntry=entry;
    firstLREntry->next=first;
  }
}

void removeFromLRList(u_int32_t dest){
  struct LREntry *toMe = NULL;
  struct LREntry *me = NULL;
  trace(TRACE_LOCAL_REPAIR,"removeFromLRList");
  if(localRepair == TRUE){
    for ( toMe = firstLREntry
	    ; toMe != NULL
	    ; toMe = toMe->next){
      if(toMe->next->dest == dest){
	me=toMe->next;
	toMe->next=me->next;
	free(me);
	return;
      }
    } 
  }
}

static void issueRERR(u_int32_t broken){
  trace(TRACE_LOCAL_REPAIR,"issueRERR");
  //if in the list
  if(inLRList(broken) == TRUE){
    //TODO what should N be? createAndSendRERR(broken,N);
    createAndSendRERR(broken,0);
  }
}


void repairLocally(u_int32_t broken) {
  struct RREQ *rreq = NULL;
  struct AodvPktInfo *info = NULL;
  int hopCount;

  trace(TRACE_LOCAL_REPAIR,"repairLocally");
  
  if(inLRList(broken) == TRUE){
    return;
  }

  hopCount = getHopCount(broken);

  if (hopCount == -1){
    log(LOG_ERR,FALSE,"repairLocally: hopcount = -1");
    return;
  }
  
  //create RREQ
  incrementDestSeqNum(broken);
  rreq = newRREQ(broken,DEFAULT_G);
  info = new_pktInfo(BROADCAST);

  //according to draft, good value of MIN_REPAIR_TTL 
  //is lastHopCount
  //therfore using hopCount + LOCAL_ADD_TTL for initial TTL
  info->ttl = hopCount + LOCAL_ADD_TTL;
  //if(MIN_REPAIR_TTL > (hopCount / 2.0)) {
  //info->ttl = MIN_REPAIR_TTL + LOCAL_ADD_TTL;
  //} else {
  //  info->ttl = (hopCount / 2.0) + LOCAL_ADD_TTL;
  //}
  
  addToLRList(broken);
  //create timer for RERR
  trace(TRACE_LOCAL_REPAIR|TRACE_TIMER,"repairLocally setting timer %u"
	,2*info->ttl*NODE_TRAVERSAL_TIME);
  timer_setTimer(2*info->ttl*NODE_TRAVERSAL_TIME
		 ,(cfunc_t)issueRERR
		 ,(void *)broken);
  
  //send RREQ
  sendDatagram(info,rreq,sizeof(struct RREQ));
}