/******************************************************************************
*
*   Name:           uip_arp.c
*
*   Description:    ARP function
*
*   Copyright:      (c) 2005-2050    IC Plus Corp.
*                   All rights reserved.  By Chance
*
*******************************************************************************/
//20051021

#include "arp.h"
#include <stdio.h>
#include <string.h>


/******************************************************************************
*
*  Function:    uip_arp_arpin
*
*  Description:  while system get the arp packet, it will send here to process
*               
*  Parameters:   None       
*               
*  Returns:     None
*               
*******************************************************************************/
void
uip_arp_arpin(void)
{ 
  if(uip_len < sizeof(struct arp_hdr)) {
    uip_len = 0;
    return;
  }
  uip_len = 0;
  switch(ARP_BUF->opcode) {
  case HTONS(ARP_REQUEST):
    /* ARP request. If it asked for our address, we send out a
       reply. */
    if(ARP_BUF->dipaddr[0] == uip_hostaddr[0] &&
       ARP_BUF->dipaddr[1] == uip_hostaddr[1]) {
      //add remote mac and ip to arp table
      /* The reply opcode is 2. */
      ARP_BUF->opcode = HTONS(ARP_REPLY);
	  //set the remote MAC address to ethernet header
      memcpy(ARP_BUF->ethhdr.dest_mac, ARP_BUF->shwaddr, 6);
      //set the remote MAC address to ARP header
      memcpy(ARP_BUF->dhwaddr, ARP_BUF->shwaddr, 6);
	  //set the MY MAC address to ethernet header
      memcpy(ARP_BUF->ethhdr.src_mac, icp_netinfo.MY_MAC, 6);
      //set the MY MAC address to ARP header
      memcpy(ARP_BUF->shwaddr, icp_netinfo.MY_MAC, 6);
      //set remote ipaddress    
      ARP_BUF->dipaddr[0] = ARP_BUF->sipaddr[0];
      ARP_BUF->dipaddr[1] = ARP_BUF->sipaddr[1];
      //set the my ip address
      ARP_BUF->sipaddr[0] = uip_hostaddr[0];
      ARP_BUF->sipaddr[1] = uip_hostaddr[1];

      ARP_BUF->ethhdr.type = HTONS(UIP_ETHTYPE_ARP);      
      uip_len = sizeof(struct arp_hdr);	  
    }   
	else
	{
		uip_len = 0;
	}   
    break;
  case HTONS(ARP_REPLY):
    uip_len = 0;
    return;
    /* ARP reply. We insert or update the ARP table if it was meant
       for us. */
   // printf("\n\r Not support!");
    break;
  }
  return;
}