NetBSD/sys/lib/libsa/rarp.c

171 lines
4.7 KiB
C

/* $NetBSD: rarp.c,v 1.5 1995/02/20 11:04:16 mycroft 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 <string.h>
#include "stand.h"
#include "net.h"
#include "netif.h"
static size_t rarpsend __P((struct iodesc *, void *, size_t));
static size_t rarprecv __P((struct iodesc *, void *, size_t, time_t));
/*
* Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
*/
n_long
rarp_getipaddress(sock)
int sock;
{
struct iodesc *d;
register struct ether_arp *ap;
struct {
u_char header[HEADER_SIZE];
struct ether_arp wrarp;
} wbuf;
struct {
u_char header[HEADER_SIZE];
struct ether_arp rrarp;
} 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(INADDR_ANY);
}
#ifdef RARP_DEBUG
if (debug)
printf("rarp: d=%x\n", (u_int)d);
#endif
ap = &wbuf.wrarp;
bzero(ap, sizeof(*ap));
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_REQUEST);
bcopy(d->myea, ap->arp_sha, 6);
bcopy(d->myea, ap->arp_tha, 6);
if (sendrecv(d,
rarpsend, ap, sizeof(*ap),
rarprecv, &rbuf.rrarp, sizeof(rbuf.rrarp)) < 0) {
printf("No response for RARP request\n");
return(INADDR_ANY);
}
return (myip);
}
/*
* Broadcast a RARP request (i.e. who knows who I am)
*/
static size_t
rarpsend(d, pkt, len)
register struct iodesc *d;
register void *pkt;
register size_t len;
{
#ifdef RARP_DEBUG
if (debug)
printf("rarpsend: called\n");
#endif
return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP));
}
/*
* Called when packet containing RARP is received
*/
static size_t
rarprecv(d, pkt, len, tleft)
register struct iodesc *d;
register void *pkt;
register size_t len;
time_t tleft;
{
register struct ether_header *eh;
register struct ether_arp *ap;
#ifdef RARP_DEBUG
if (debug)
printf("rarprecv: called\n");
#endif
len = readether(d, pkt, len, tleft);
if (len == -1 || len < sizeof(struct ether_arp))
goto bad;
eh = (struct ether_header *)pkt - 1;
if (ntohs(eh->ether_type) != ETHERTYPE_REVARP)
goto bad;
ap = (struct ether_arp *)pkt;
if (ntohs(ap->arp_op) != ARPOP_REPLY ||
ntohs(ap->arp_pro) != ETHERTYPE_IP)
goto bad;
if (bcmp(ap->arp_tha, d->myea, 6))
goto bad;
bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip));
bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip));
return (0);
bad:
errno = 0;
return (-1);
}