build_arp.c

裸板的tftp客户端

#include "./include/build_arp.h"

int BuildARP(U8 *PacketPage, U8 *ClientMac, U8 *ClientIp, U8 *HostIp)
{
	int i=0;
	for(i = 0; i < 6; i++)
	{	
		PacketPage[i]=0xff;
		PacketPage[6+i]=ClientMac[i];
	}	
	PacketPage[12]=0x08;	
	PacketPage[13]=0x06;
	PacketPage[14]=0x00;	// Hard type 0x0001 ethnet
	PacketPage[15]=0x01;
	PacketPage[16]=0x08;	// protocol type 0x0800 ip
	PacketPage[17]=0x00;
	PacketPage[18]=0x06;	// hard address len 0x04
	PacketPage[19]=0x04;	// protocol len 0x04
	PacketPage[20]=0x00;	// request 0x0001 ack 0x0002
	PacketPage[21]=0x01;	// arp request
	for(i = 0; i < 6; i++)
	{
		PacketPage[22+i]=ClientMac[i];	//source mac
		PacketPage[32+i]=0x00;	// destination mac
		
	}
	for(i=0;i<4;i++)
	{
		PacketPage[28+i]=ClientIp[i];	//source ip
		PacketPage[38+i]=HostIp[i];	//destination ip
	}
	return 42; 
}