rreqresend.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 <netinet/in.h>
#include <sys/types.h>
#include <stdlib.h>

#include "aodvConst.h"
#include "aodvSocket.h"
#include "callout.h"
#include "const.h"
#include "debug.h"
#include "inet.h"
#include "packet_input.h"
#include "routingTable.h"
#include "rreq.h"
#include "sendDatagram.h"

struct REntry {
  int tries;
  struct RREQ *rreq;
  struct AodvPktInfo *info;
  struct REntry *next;
};

static struct REntry *firstREntry = NULL;

static struct REntry *find(u_int32_t dest){
  struct REntry *entry = NULL;
  struct RREQ *rreq = NULL;

  trace(TRACE_RREQ_RESEND,"RreqResend:find(%s)",inet_fmt_h(dest,s1));

  for(entry = firstREntry
	  ; entry != NULL
	  ; entry = entry->next){

    if(entry->rreq != NULL){
      trace(TRACE_RREQ_RESEND,"RreqResend:found entry");
      rreq=entry->rreq;
      if ( (rreq->dest != NULL) && (ntohl(rreq->dest) == dest) ) {
	trace(TRACE_RREQ_RESEND,"RreqResend:returning entry");
	return entry;
      }
    } else {
      trace(TRACE_RREQ_RESEND,"RreqResend:find HAVE NULL entry->rreq");
    }
  }
  trace(TRACE_RREQ_RESEND,"RreqResend:returning NULL");
  return NULL;
}


int rreqPending(u_int32_t dst){
  if(find(dst) == NULL){
    return FALSE;
  }else{
    return TRUE;
  }
}

static void removeEntry(struct REntry *entry){
  struct REntry *toMe = NULL; 
  
  trace(TRACE_RREQ_RESEND,"RreqResend:removeEntry");
  //go through list and find who is pointing to entry
  if(firstREntry != NULL && entry != NULL){
    trace(TRACE_RREQ_RESEND,"RreqResend:removeEntry(%s)"
	  ,inet_fmt_n(entry->rreq->dest,s1));
    if(entry==firstREntry){
      trace(TRACE_RREQ_RESEND,"RreqResend:entry==firstEntry");
      firstREntry=firstREntry->next;
      //free RREQ
      free(entry->rreq);
      //free AodvPktInfo
      free(entry->info);
      //free REntry
      free(entry);
      entry = NULL;
      return;
    }else{
      for(toMe = firstREntry
	    ; toMe != NULL
	    ; toMe = entry->next) {
	if (toMe->next == entry) {
	  trace(TRACE_RREQ_RESEND,"RreqResend:entry!=firstEntry");
	  toMe->next=entry->next;
	  //free RREQ
	  free(entry->rreq);
	  //free AodvPktInfo
	  free(entry->info);
	  //free REntry
	  free(entry);
	  entry = NULL;
	  return;
	}
      }
      trace(TRACE_RREQ_RESEND,"RreqResend: remove(entry not found)");
    }
  }
}

void removeFromRreqResend(u_int32_t dest){
  struct REntry *entry = NULL;
  entry=find(dest);
  removeEntry(entry);
}

//static void removeFromRreqResend(u_int32_t dest){
  //set timer to remove route in one second
  //otherwise another rreq might be generated
  //needed because of possible delay of route update
//  trace(TRACE_RREQ_RESEND|TRACE_TIMER,"removeFromRreqResend setTimer 1000");
//  timer_setTimer(1000,(cfunc_t) removeFromRreqResend1,(void *) dest);
//}
static void resendRREQ(u_int32_t dest){
  struct REntry *entry = NULL;
  trace(TRACE_RREQ_RESEND, "resendRreq(dest=%s"
      ,inet_fmt_h(dest,s1));
  entry=find(dest);
  if(entry != NULL){
    if(entry->tries <= RREQ_RETRIES){
      if(expandingRingSearch == TRUE) {
	entry->info->ttl = entry->info->ttl + TTL_INCREMENT;
	if(entry->info->ttl >= TTL_THRESHOLD){
	  entry->info->ttl = NET_DIAMETER;
	}
      }
      trace(TRACE_DEMO, "resending RREQ to dest=%s"
	    ,inet_fmt_h(dest,s1));
      trace(TRACE_RREQ_RESEND, "resendRreq: resending rreq");
      entry->rreq->broadcastId = htonl(broadcastId++);
      mySeqNum++;
      entry->rreq->srcSeqNum = htonl(mySeqNum);
      entry->rreq->destSeqNum = htonl(getDestinationSeqNum(ntohl(entry->rreq->dest)));
      printRREQ(entry->rreq);
      trace(TRACE_METRIC,"s r RREQ");
      sendDatagram(entry->info,entry->rreq,sizeof(struct RREQ));

      if(entry->info->ttl == NET_DIAMETER){
	(entry->tries)++;
      }

      //set timer to resend
      if(expandingRingSearch == FALSE){
	trace(TRACE_RREQ_RESEND|TRACE_TIMER
	      ,"resendRREQ setting timer %u",NET_TRAVERSAL_TIME);
	timer_setTimer(NET_TRAVERSAL_TIME
		       ,(cfunc_t)resendRREQ
		       ,(void *)dest);
      } else {
	trace(TRACE_RREQ_RESEND|TRACE_TIMER
	      ,"resendRREQ setting timer %u"
	      ,2*entry->info->ttl*NODE_TRAVERSAL_TIME);
	timer_setTimer(2*entry->info->ttl*NODE_TRAVERSAL_TIME
		       ,(cfunc_t)resendRREQ
		       ,(void *)dest);
      }
    } else {
      packet_buff_drop(dest);
      removeEntry(entry);
    }
  }
}

static void insert(struct REntry *entry){
  struct REntry *first = NULL;
  first=firstREntry;
  firstREntry=entry;
  firstREntry->next=first;
}



void insertRREQIntoResendList(struct AodvPktInfo *info, struct RREQ *rreq){
  struct REntry *entry = NULL;
  int newlyCreated = FALSE;
  
  trace(TRACE_RREQ_RESEND, "insertRreqIntoResendList(info->src=%s"
      ,inet_fmt_n(info->src,s1));
  trace(TRACE_RREQ_RESEND, "insertRreqIntoResendList(rreq->dest=%s"
      ,inet_fmt_n(rreq->dest,s1));
  entry = find(ntohl(rreq->dest));
  
  if(entry == NULL){
    //create entry
    entry = (struct REntry *)malloc(sizeof(struct REntry));
    if(entry == NULL){
      log(LOG_ERR,TRUE,"unable to allocate memory, REntry");
    }
  
    trace(TRACE_RREQ_RESEND,"insertRreqIntoResendList:ADDRESS:%u",entry);
    entry->tries = 1;
    entry->next = NULL;
    newlyCreated=TRUE;
  }
  
  entry->info=info;
  entry->rreq=rreq;
  if(newlyCreated == TRUE){
    insert(entry);
  }

  //set timer to resend
  if(expandingRingSearch == FALSE){
    trace(TRACE_RREQ_RESEND|TRACE_TIMER
	  ,"insertRreqIntoResendList:timer:%u"
	  ,NET_TRAVERSAL_TIME);
    timer_setTimer(NET_TRAVERSAL_TIME
		   ,(cfunc_t)resendRREQ
		   ,(void *)ntohl(rreq->dest));
  } else {
    trace(TRACE_RREQ_RESEND|TRACE_TIMER
	  ,"insertRreqIntoResendList:timer:%u"
	  ,2*info->ttl*NODE_TRAVERSAL_TIME);
    timer_setTimer(2*info->ttl*NODE_TRAVERSAL_TIME
		   ,(cfunc_t)resendRREQ
		   ,(void *)ntohl(rreq->dest));
  }
}