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/* $OpenBSD: rarp.c,v 1.10 2003/08/11 06:23:09 deraadt Exp $ */
/* $NetBSD: rarp.c,v 1.13 1996/10/13 02:29:05 christos Exp $ */
/*
* Copyright (c) 1992 Regents of the University of California.
* All rights reserved.
*
* This software was developed by the Computer Systems Engineering group
* at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
* contributed to Berkeley.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Lawrence Berkeley Laboratory and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL)
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <netinet/in_systm.h>
#include "stand.h"
#include "net.h"
#include "netif.h"
static ssize_t rarpsend(struct iodesc *, void *, size_t);
static ssize_t rarprecv(struct iodesc *, void *, size_t, time_t);
/*
* Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
*/
int
rarp_getipaddress(int sock)
{
struct iodesc *d;
struct ether_arp *ap;
struct {
u_char header[ETHER_SIZE];
struct {
struct ether_arp arp;
u_char pad[18]; /* 60 - sizeof(arp) */
} data;
} wbuf;
struct {
u_char header[ETHER_SIZE];
struct {
struct ether_arp arp;
u_char pad[24]; /* extra space */
} data;
} rbuf;
#ifdef RARP_DEBUG
if (debug)
printf("rarp: socket=%d\n", sock);
#endif
if (!(d = socktodesc(sock))) {
printf("rarp: bad socket. %d\n", sock);
return (-1);
}
#ifdef RARP_DEBUG
if (debug)
printf("rarp: d=%x\n", (u_int)d);
#endif
bzero((char *)&wbuf.data, sizeof(wbuf.data));
ap = &wbuf.data.arp;
ap->arp_hrd = htons(ARPHRD_ETHER);
ap->arp_pro = htons(ETHERTYPE_IP);
ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */
ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */
ap->arp_op = htons(ARPOP_REVREQUEST);
bcopy(d->myea, ap->arp_sha, 6);
bcopy(d->myea, ap->arp_tha, 6);
if (sendrecv(d,
rarpsend, &wbuf.data, sizeof(wbuf.data),
rarprecv, &rbuf.data, sizeof(rbuf.data)) < 0)
{
printf("No response for RARP request\n");
return (-1);
}
ap = &rbuf.data.arp;
bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip));
#if 0
/* XXX - Can NOT assume this is our root server! */
bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip));
#endif
/* Compute our "natural" netmask. */
if (IN_CLASSA(myip.s_addr))
netmask = IN_CLASSA_NET;
else if (IN_CLASSB(myip.s_addr))
netmask = IN_CLASSB_NET;
else
netmask = IN_CLASSC_NET;
d->myip = myip;
return (0);
}
/*
* Broadcast a RARP request (i.e. who knows who I am)
*/
static ssize_t
rarpsend(struct iodesc *d, void *pkt, size_t len)
{
#ifdef RARP_DEBUG
if (debug)
printf("rarpsend: called\n");
#endif
return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP));
}
/*
* Returns 0 if this is the packet we're waiting for
* else -1 (and errno == 0)
*/
static ssize_t
rarprecv(struct iodesc *d, void *pkt, size_t len, time_t tleft)
{
ssize_t n;
struct ether_arp *ap;
u_int16_t etype; /* host order */
#ifdef RARP_DEBUG
if (debug)
printf("rarprecv: ");
#endif
n = readether(d, pkt, len, tleft, &etype);
errno = 0; /* XXX */
if (n < 0 || (size_t)n < sizeof(struct ether_arp)) {
#ifdef RARP_DEBUG
if (debug)
printf("bad len=%d\n", n);
#endif
return (-1);
}
if (etype != ETHERTYPE_REVARP) {
#ifdef RARP_DEBUG
if (debug)
printf("bad type=0x%x\n", etype);
#endif
return (-1);
}
ap = (struct ether_arp *)pkt;
if (ap->arp_hrd != htons(ARPHRD_ETHER) ||
ap->arp_pro != htons(ETHERTYPE_IP) ||
ap->arp_hln != sizeof(ap->arp_sha) ||
ap->arp_pln != sizeof(ap->arp_spa) )
{
#ifdef RARP_DEBUG
if (debug)
printf("bad hrd/pro/hln/pln\n");
#endif
return (-1);
}
if (ap->arp_op != htons(ARPOP_REVREPLY)) {
#ifdef RARP_DEBUG
if (debug)
printf("bad op=0x%x\n", ntohs(ap->arp_op));
#endif
return (-1);
}
/* Is the reply for our Ethernet address? */
if (bcmp(ap->arp_tha, d->myea, 6)) {
#ifdef RARP_DEBUG
if (debug)
printf("unwanted address\n");
#endif
return (-1);
}
/* We have our answer. */
#ifdef RARP_DEBUG
if (debug)
printf("got it\n");
#endif
return (n);
}
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