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/* $Id: arp.c,v 0.3 1997/08/30 16:50:44 yoichi v0_70 $
*
* dhcpcd - DHCP client daemon -
* Copyright (C) 1996 - 1997 Yoichi Hariguchi <yoichi@fore.com>
*
* Dhcpcd is an RFC2131 and RFC1541 compliant DHCP client daemon.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
/*#include <linux/netdevice.h>*/
#include <netinet/if_ether.h>
#include <net/if_arp.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "dhcp.h"
#include <net/if.h>
#include "if.h"
#include "arp.h"
#include "socket-if.h"
#include "error-handler.h"
int
arpCheck(u_long inaddr, struct ifinfo *ifbuf, long timeout)
{
int s; /* socket */
int rv; /* return value */
struct sockaddr addr; /* for interface name */
struct arpMsg arp;
fd_set fdset;
struct timeval tm;
time_t prevTime;
rv = 1;
openRawSocket(&s, ETH_P_ARP);
/* send arp request
*/
mkArpMsg(ARPOP_REQUEST, inaddr, NULL, ifbuf->addr, ifbuf->haddr, &arp);
bzero(&addr, sizeof(addr));
strcpy(addr.sa_data, ifbuf->ifname);
if ( sendto(s, &arp, sizeof(arp), 0, &addr, sizeof(addr)) < 0 ) {
logSysRet("sendto (arpCheck)");
rv = 0;
}
/* wait arp reply, and check it
*/
tm.tv_usec = 0;
time(&prevTime);
while ( timeout > 0 ) {
FD_ZERO(&fdset);
FD_SET(s, &fdset);
tm.tv_sec = timeout;
if ( select(s+1, &fdset, (fd_set *)NULL, (fd_set *)NULL, &tm) < 0 ) {
logSysRet("select (arpCheck)");
rv = 0;
}
if ( FD_ISSET(s, &fdset) ) {
if (recv(s, &arp, sizeof(arp), 0) < 0 ) {
logSysRet("recv (arpCheck)");
rv = 0;
}
if ( arp.operation == htons(ARPOP_REPLY) &&
bcmp(arp.tHaddr, ifbuf->haddr, 6) == 0 &&
*((u_int *)arp.sInaddr) == inaddr ) {
rv = 0;
break;
}
}
timeout -= time(NULL) - prevTime;
time(&prevTime);
}
close(s);
return rv;
}
void
sendArpReply(u_char *thaddr, u_long tinaddr, struct ifinfo *ifbuf)
{
int s; /* socket */
struct sockaddr addr; /* for interface name */
struct arpMsg arp;
openRawSocket(&s, htons(ETH_P_ARP));
/* send arp reply
*/
mkArpMsg(ARPOP_REPLY, tinaddr, thaddr, ifbuf->addr, ifbuf->haddr, &arp);
bzero(&addr, sizeof(addr));
strcpy(addr.sa_data, ifbuf->ifname);
if ( sendto(s, &arp, sizeof(arp), 0, &addr, sizeof(addr)) < 0 ) {
logSysRet("sendto (arpCheck)");
}
}
void
mkArpMsg(int opcode, u_long tInaddr, u_char *tHaddr,
u_long sInaddr, u_char *sHaddr, struct arpMsg *msg)
{
bzero(msg, sizeof(*msg));
bcopy(MAC_BCAST_ADDR, msg->ethhdr.h_dest, 6); /* MAC DA */
bcopy(sHaddr, msg->ethhdr.h_source, 6); /* MAC SA */
msg->ethhdr.h_proto = htons(ETH_P_ARP); /* protocol type (Ethernet) */
msg->htype = htons(ARPHRD_ETHER); /* hardware type */
msg->ptype = htons(ETH_P_IP); /* protocol type (ARP message) */
msg->hlen = 6; /* hardware address length */
msg->plen = 4; /* protocol address length */
msg->operation = htons(opcode); /* ARP op code */
*((u_int *)msg->sInaddr) = sInaddr; /* source IP address */
bcopy(sHaddr, msg->sHaddr, 6); /* source hardware address */
*((u_int *)msg->tInaddr) = tInaddr; /* target IP address */
if ( opcode == ARPOP_REPLY ) {
bcopy(tHaddr, msg->tHaddr, 6); /* target hardware address */
}
}
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