arp.c~

#include "arp.h"
#include "ipv4.h"
#include <stdlib.h>

/* ARP frame header structure */
struct arp_frame
{
	unsigned short hrd_type;
	unsigned short prot_type;
	unsigned char hrd_len;
	unsigned char prot_len;
	unsigned short opcode;
	mac_addr_t mac_src;
	ipv4_addr_t ip_src;
	mac_addr_t mac_dst;
	ipv4_addr_t ip_dst;
	
};

int arp_resolve (eth_iface_t* iface, ipv4_addr_t dest, mac_addr_t mac)
{

	/* Create ARP request header */
	struct arp_frame req;
	req.hrd_type = 0x0001;				// Ethernet
	req.prot_type = 0x0800;				// IP
	req.hrd_len = 6;					// MAC address length (bytes)
	req.prot_len = 4;					// IP address length (bytes)
	req.opcode = REQUEST;				// ARP request
	
	eth_getaddr (iface, req.mac_src);	//eth iface address

	ipv4_str_addr("0.0.0.0", req.ip_src);// Source IP address
	mac_str_addr((char *)MAC_BCAST_ADDR, req.mac_dst);// MAC broadcast
	req.ip_dst = dest;					// Destination IP address

	/* Send ARP request */
	eth_send (iface,req.mac_dst, ARP_TYPE, (unsigned char *)&req, ARP_LEN);

	/* Wait for answer */
	struct arp_frame rep;
	unsigned char found = 0;
	do
	{		
		if (eth_recv (iface, req.mac_src, ARP_TYPE, (unsigned char *)&rep, -1) == 28)
		{
			if ((rep.opcode == REPLY) && (rep.ip_src == req.ip_dst))
			{
				memcpy(&mac, &rep.mac_src, MAC_ADDR_SIZE);
				found = 1;
			}
		}
	}
	while (!found);

	return found;
}