/*	Copyright 2001, 2002 Georges Menie (www.menie.org)	This file is part of Tftpnaive.    Tftpnaive is free software; you can redistribute it and/or modify    it under the terms of the GNU Lesser General Public License as published by    the Free Software Foundation; either version 2 of the License, or    (at your option) any later version.    Tftpnaive 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 Lesser General Public License for more details.    You should have received a copy of the GNU Lesser General Public License    along with Tftpnaive; if not, write to the Free Software    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA*/#include "tftpnaive.h"#include "net.h"#include "baselib.h"#define MAXARPENTRIES 16static struct arp_entry {	unsigned int ip;	unsigned char ia[6];	char ok;} arpCache[MAXARPENTRIES];static int arpCacheCnt;static int updateAddr (ARPpkt * p){	int i, f = 0;	for (i = 0; i < MAXARPENTRIES; ++i) {		if (arpCache[i].ip == p->sender_ipaddr) {			if (f) {				arpCache[i].ok = 0;			}			else if (arpCache[i].ok != 0) {				memcpy (arpCache[i].ia, p->sender_hwaddr, 6);				arpCache[i].ok = f = 1;			}		}	}	return f;}static void addAddr (ARPpkt * p){	memcpy (arpCache[arpCacheCnt].ia, p->sender_hwaddr, 6);	arpCache[arpCacheCnt].ip = p->sender_ipaddr;	arpCache[arpCacheCnt].ok = 1;	arpCacheCnt = (arpCacheCnt + 1) % MAXARPENTRIES;}int sendARPRequest (unsigned int sender_ip, unsigned int target_ip){	ARPpkt p;	int i;	for (i = 0; i < 6; ++i)		p.ehdr.dst_hwadr[i] = 0xff;	memcpy (p.ehdr.src_hwadr, netif.IEEEIA, 6);	p.ehdr.frametype = FRAME_ARP;	p.hardtype = ARP_ETH;	p.prottype = FRAME_IP;	p.hardsize = 6;	p.protsize = 4;	p.op = ARP_REQUEST;	memcpy (p.sender_hwaddr, netif.IEEEIA, 6);	p.sender_ipaddr = sender_ip;	memset (p.target_hwaddr, 0, 6);	p.target_ipaddr = target_ip;	return netif.send (&p, sizeof (ARPpkt));}unsigned char *lookupARP (unsigned int ip){	int i;	for (i = 0; i < MAXARPENTRIES; ++i) {		if (arpCache[i].ip == ip) {			if (arpCache[i].ok == 1)				return arpCache[i].ia;			if (arpCache[i].ok == 2)				return 0;		}	}	arpCache[arpCacheCnt].ip = ip;	arpCache[arpCacheCnt].ok = 2;	arpCacheCnt = (arpCacheCnt + 1) % MAXARPENTRIES;	return 0;}#if 0void listARPCache (void){	int i;	printf ("ARP Cache entries:\n");	for (i = 0; i < MAXARPENTRIES; ++i) {		if (arpCache[i].ok == 1) {			printf ("%d.%d.%d.%d is-at %02X:%02X:%02X:%02X:%02X:%02X\n",					(arpCache[i].ip >> 24) & 0xff,					(arpCache[i].ip >> 16) & 0xff,					(arpCache[i].ip >> 8) & 0xff, (arpCache[i].ip) & 0xff,					arpCache[i].ia[0], arpCache[i].ia[1], arpCache[i].ia[2],					arpCache[i].ia[3], arpCache[i].ia[4], arpCache[i].ia[5]);		}	}}#endifvoid processARP (unsigned char *pkt, unsigned short len){	register ARPpkt *p = (ARPpkt *) pkt;	if (len >= sizeof (ARPpkt)) {		if (p->hardtype == ARP_ETH && p->prottype == FRAME_IP && netif.ip) {			if (p->hardsize == 6 && p->protsize == 4) {				if (p->op == ARP_REQUEST) {					if (!updateAddr (p)) {						addAddr (p);					}					if (netif.ip == p->target_ipaddr) {						p->op = ARP_REPLY;						memcpy (p->target_hwaddr, p->sender_hwaddr, 10);						p->sender_ipaddr = netif.ip;						memcpy (p->sender_hwaddr, netif.IEEEIA, 6);						memcpy (pkt, pkt + 6, 6);						memcpy (pkt + 6, netif.IEEEIA, 6);						netif.send (pkt, sizeof (ARPpkt));					}				}				else if (p->op == ARP_REPLY) {					if (p->sender_ipaddr == netif.ip) {						netif.ip = 0;						printf ("IP conflict : ");						printf							("ARP reply: %d.%d.%d.%d is-at %02X:%02X:%02X:%02X:%02X:%02X\n",							 (p->sender_ipaddr >> 24) & 0xff,							 (p->sender_ipaddr >> 16) & 0xff,							 (p->sender_ipaddr >> 8) & 0xff,							 (p->sender_ipaddr) & 0xff, p->sender_hwaddr[0],							 p->sender_hwaddr[1], p->sender_hwaddr[2],							 p->sender_hwaddr[3], p->sender_hwaddr[4],							 p->sender_hwaddr[5]);					}					updateAddr (p);				}			}		}	}}