arp.c

力天电子 dsp源码

/******************************************************************/
/*Copyright (C), 2008-2009, 力天电子，LiTian Tech.Co.Ltd.		  */
/*  Module Name   : ENC28J60           							  */
/*  File Name     : ARP.c	    								  */        
/*  Author   	  : 侯长波                                        */     
/*  Create Date   : 2009/10/1                                     */      
/*  Version   	  : 1.0                                           */          
/*  Function      : 测试ENC28J60                                  */                       
/*  Description   : arp相关函数                                   */            
/*  Support       : www.LT430.com 				                  */             
/******************************************************************/ 
#include "Ne2000.h"

extern void encPacketSend(union ethernet_address_type *pDestAddr, union netcard *txdnet,
                   unsigned int buffer_length, unsigned int packet_type); 

extern union netcard rxdnetbuf;
extern union netcard txdnetbuf;
extern union NetNode myNode;

union arp_table_type arp_tab[MaxLenARPtable];
static unsigned char	arpindex = 0;	//ARP table 循环加入点

/*==============================================*/
//	函数名称:	arp动态缓冲区初始化
/*==============================================*/
void arptab_init(void)
{
	unsigned char	i,j;
	for(i = 0; i < MaxLenARPtable; i++)
	{
		for(j = 0; j < 12; j++)
		{
			arp_tab[i].bytes[j] = 0;
		}
	}
}

/*==============================================*/
//	函数名称:	arp请求
/*==============================================*/
void arp_request(union ip_address_type *ip_address)
{
	unsigned char	i;
	union ethernet_address_type castaddress;

	for(i = 0; i < 6; i++)
	{
		castaddress.bytes[i] = 0xFF;
		txdnetbuf.arpframe.sourcenodeid[i] = myNode.node.mac[i];
	}

	for(i = 0; i < 4; i++)
	{
		txdnetbuf.arpframe.sourceip[i] = myNode.nodebytes.ipbytes[i];
		txdnetbuf.arpframe.destip[i] = ip_address->bytes[i];
	}
	txdnetbuf.arpframe.halength=0x06;
	txdnetbuf.arpframe.palength=0x04;
 	for(i=46;i<64;i++)
		txdnetbuf.bytedata.bytebuf[i]=0x00;
	encPacketSend(&castaddress,&txdnetbuf,60,ARP_PACKET);
}

/*==============================================*/
//	函数名称:	arp应答
/*==============================================*/
void arp_answer(void)
{
	unsigned char	i;
	union ethernet_address_type answer_address;

	if( (rxdnetbuf.arpframe.destip[0] == myNode.nodebytes.ipbytes[0])
		&& (rxdnetbuf.arpframe.destip[1] == myNode.nodebytes.ipbytes[1])
		&& (rxdnetbuf.arpframe.destip[2] == myNode.nodebytes.ipbytes[2])
		&& (rxdnetbuf.arpframe.destip[3] == myNode.nodebytes.ipbytes[3]))
	{								//表示是向我这个ip地址的请求
	    	for(i = 14; i < 64; i++)//复制arp到发送缓冲区
			{							
	    		txdnetbuf.bytedata.bytebuf[i]=rxdnetbuf.bytedata.bytebuf[i];
	    	}
	    	for(i = 0; i < 6; i++)//复制对方网卡地址或网关地址
			{						   
				answer_address.bytes[i]=rxdnetbuf.etherframe.sourcenodeid[i];
				txdnetbuf.arpframe.sourcenodeid[i]=myNode.node.mac[i];
				txdnetbuf.arpframe.destnodeid[i]=rxdnetbuf.arpframe.sourcenodeid[i];
	    	}
			for(i = 0; i < 4; i++)
			{
			txdnetbuf.arpframe.destip[i]=rxdnetbuf.arpframe.sourceip[i];
			txdnetbuf.arpframe.sourceip[i]=rxdnetbuf.arpframe.destip[i];
			}
	  		txdnetbuf.arpframe.operation_L=ARP_Answer;//响应代码
			txdnetbuf.arpframe.operation_H=(ARP_Answer>>8);//响应代码
			encPacketSend(&answer_address,&txdnetbuf,60,ARP_PACKET);
	}
}

/*==============================================*/
//	函数名称:	arp应答处理
/*==============================================*/
void arp_process(void)
{	
	unsigned char	i,j;

	for(i = 0; i < MaxLenARPtable; i++)
	{
		if(arp_tab[i].arp.status == 1)
		{
			if((arp_tab[i].arp.ip_address.bytes[0] == rxdnetbuf.arpframe.sourceip[0])
				&& (arp_tab[i].arp.ip_address.bytes[1] == rxdnetbuf.arpframe.sourceip[1])
				&& (arp_tab[i].arp.ip_address.bytes[2] == rxdnetbuf.arpframe.sourceip[2])
				&& (arp_tab[i].arp.ip_address.bytes[3] == rxdnetbuf.arpframe.sourceip[3]))
			{
				arp_tab[i].arp.ttl=0x80;
				for(j = 0; j < 4; j++)
					arp_tab[i].arp.ip_address.bytes[j]=rxdnetbuf.arpframe.sourceip[j];
				for(j = 0; j < 6; j++)
					arp_tab[i].arp.ethernet_address.bytes[j]=rxdnetbuf.arpframe.sourcenodeid[j];
				return;
			}
		}
		
	}

	for(i = 0;i < MaxLenARPtable; i++)
	{
		if(arp_tab[i].arp.status == 0)
		{
			arp_tab[i].arp.status = 1;
			arp_tab[i].arp.ttl = 0x80;
			for(j = 0; j < 4; j++)
				arp_tab[i].arp.ip_address.bytes[j] = rxdnetbuf.arpframe.sourceip[j];
			for(j = 0;j < 6; j++)
				arp_tab[i].arp.ethernet_address.bytes[j] = rxdnetbuf.arpframe.sourcenodeid[j];
			return;
		}
	}

	arp_tab[arpindex].arp.status = 1;		//write arp package to some location.
	arp_tab[arpindex].arp.ttl = 0x80;
	for(j = 0; j < 4; j++)
		arp_tab[arpindex].arp.ip_address.bytes[j] = rxdnetbuf.arpframe.sourceip[j];
	for(j = 0; j < 6; j++)
		arp_tab[arpindex].arp.ethernet_address.bytes[j] = rxdnetbuf.arpframe.sourcenodeid[j];
	arpindex++;
	if(arpindex == MaxLenARPtable)
		arpindex = 0;
}

/*==============================================*/
//	函数名称:	更新ARP缓存
/*==============================================*/
void updatearptab(void)
{
	unsigned char	i;

	for(i = 0; i < MaxLenARPtable; i++)
	{
		if(arp_tab[i].arp.status == 1)
		{
			if(arp_tab[i].arp.ttl == 0)
			{
				arp_tab[i].arp.status=0;	
			}
			else
			{
				arp_tab[i].arp.ttl--;
			}
		}
	}
}

/*==============================================*/
//	函数名称:	在ARP缓存中查找指定IP/MAC映射对
/*==============================================*/
unsigned char arp_find_mac(union ip_address_type ip,union ethernet_address_type *macadr)
{
	unsigned char	i,j;

	for(i = 0; i < MaxLenARPtable; i++)
	{
		if(arp_tab[i].arp.status == 1)
			if(arp_tab[i].arp.ip_address.dwords == ip.dwords)
			{
				for(j = 0; j < 6; j++)
					macadr->bytes[j] = arp_tab[i].arp.ethernet_address.bytes[j];
				return 1;
		    }
	}
	return 0;
}

/*==============================================*/
//	函数名称:	在ARP缓存中直接加入IP/MAC映射对
/*==============================================*/
void arp_ip_mac(void)
{
	unsigned char	i,j;

	for(i = 0; i < MaxLenARPtable; i++)
	{
		if(arp_tab[i].arp.status == 1)
		{
			if((arp_tab[i].arp.ip_address.bytes[0] == rxdnetbuf.ipframe.sourceip[0])
				&& (arp_tab[i].arp.ip_address.bytes[1] == rxdnetbuf.ipframe.sourceip[1])
				&& (arp_tab[i].arp.ip_address.bytes[2] == rxdnetbuf.ipframe.sourceip[2])
				&& (arp_tab[i].arp.ip_address.bytes[3] == rxdnetbuf.ipframe.sourceip[3]))
			{
				arp_tab[i].arp.ttl=0x80;
				for(j = 0; j < 4; j++)
					arp_tab[i].arp.ip_address.bytes[j] = rxdnetbuf.ipframe.sourceip[j];
				for(j = 0; j < 6; j++)
					arp_tab[i].arp.ethernet_address.bytes[j] = rxdnetbuf.etherframe.sourcenodeid[j];
				return;
			}
		}
		
	}

	for(i = 0;i < MaxLenARPtable; i++)
	{
		if(arp_tab[i].arp.status == 0)
		{
			arp_tab[i].arp.status = 1;
			arp_tab[i].arp.ttl = 0x80;
			for(j = 0; j < 4; j++)
				arp_tab[i].arp.ip_address.bytes[j] = rxdnetbuf.ipframe.sourceip[j];
			for(j = 0;j < 6; j++)
				arp_tab[i].arp.ethernet_address.bytes[j] = rxdnetbuf.etherframe.sourcenodeid[j];
			return;
		}
	}

	arp_tab[arpindex].arp.status = 1;		//write arp package to some location.
	arp_tab[arpindex].arp.ttl = 0x80;
	for(j = 0; j < 4; j++)
		arp_tab[arpindex].arp.ip_address.bytes[j] = rxdnetbuf.ipframe.sourceip[j];
	for(j = 0; j < 6; j++)
		arp_tab[arpindex].arp.ethernet_address.bytes[j] = rxdnetbuf.etherframe.sourcenodeid[j];
	arpindex++;
	if(arpindex == MaxLenARPtable)
		arpindex = 0;
}