packet.c

wifi 无线网络路由协议OLSR linux下C代码

/*
 * OLSR ad-hoc routing table management protocol GUI front-end
 * Copyright (C) 2003 Andreas T鴑nesen ([e-mail])
 *
 * This file is part of olsr.org.
 *
 * uolsrGUI 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.
 *
 * uolsrGUI 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 olsr.org; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/*
 *Andreas T鴑nesen ([e-mail])
 *
 *The list of cached packets
 *
 */

#include "common.h"
#include "packet.h"

struct packnode *packets = NULL;
int no_packets = 0;

/*
 *Add the contets of a packet to
 *the cached packets
 */
int
add_packet_to_buffer(union olsr_message *p, int size)
{
  struct packnode *tmp;
  /* Should be the same for v4 and v6 */


  /* If this is the first packet */
  if(!packets)
    {
      //printf("Adding first packet\n");
      packets = malloc(sizeof(struct packnode));
      packets->packet = malloc(size);
      memcpy(packets->packet, p, size);
      packets->next = NULL;
      no_packets++;
      return 1;
    }
  else
    {
      /* If the buffer is not full */
      if(no_packets < MAXPACKS)
	{
	  //printf("Buffer not filled yet..\n");
	  tmp = packets;
	  packets = malloc(sizeof(struct packnode));
	  packets->packet = malloc(size);
	  memcpy(packets->packet, p, size);
	  packets->next = tmp;
	  no_packets++;
	  return 1;
	}
      /* If buffer is full */
      else
	{
	  //printf("Buffer full - deleting...\n");
	  tmp = packets;
	  /* Find second last packet */
	  while(tmp->next->next)
	    {
	      tmp = tmp->next;
	    }
	  /* Delete last packet */
	  free(tmp->next->packet);
	  free(tmp->next);
	  tmp->next = NULL;

	  /*Add the new packet */
	  tmp = packets;
	  packets = malloc(sizeof(struct packnode));
	  packets->packet = malloc(size);
	  memcpy(packets->packet, p, size);
	  packets->next = tmp;
	  return 1;
	}

    }
  return 0;
}



/*
 *Get the packet with index 'index'
 */
union olsr_message *
get_packet(int index)
{
  int i = 0;
  struct packnode *tmp;

  if(index>MAXPACKS)
    return 0;

  if(index == 0)
    return packets->packet;

  tmp = packets;

  while(i != index)
    {
      tmp = tmp->next;
      i++;
    }
  return tmp->packet;

}