1 /* $NetBSD: rarp.c,v 1.16 1997/07/07 15:52:52 drochner Exp $ */
4 * Copyright (c) 1992 Regents of the University of California.
7 * This software was developed by the Computer Systems Engineering group
8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9 * contributed to Berkeley.
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Lawrence Berkeley Laboratory and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
39 * @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL)
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
45 #include <sys/param.h>
46 #include <sys/socket.h>
48 #include <netinet/in.h>
49 #include <netinet/if_ether.h>
51 #include <netinet/in_systm.h>
60 static ssize_t rarpsend(struct iodesc *, void *, size_t);
61 static ssize_t rarprecv(struct iodesc *, void *, size_t, time_t);
64 * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
67 rarp_getipaddress(sock)
71 register struct ether_arp *ap;
73 u_char header[ETHER_SIZE];
76 u_char pad[18]; /* 60 - sizeof(arp) */
80 u_char header[ETHER_SIZE];
83 u_char pad[24]; /* extra space */
89 printf("rarp: socket=%d\n", sock);
91 if (!(d = socktodesc(sock))) {
92 printf("rarp: bad socket. %d\n", sock);
97 printf("rarp: d=%x\n", (u_int)d);
100 bzero((char*)&wbuf.data, sizeof(wbuf.data));
102 ap->arp_hrd = htons(ARPHRD_ETHER);
103 ap->arp_pro = htons(ETHERTYPE_IP);
104 ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */
105 ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */
106 ap->arp_op = htons(ARPOP_REVREQUEST);
107 bcopy(d->myea, ap->arp_sha, 6);
108 bcopy(d->myea, ap->arp_tha, 6);
111 rarpsend, &wbuf.data, sizeof(wbuf.data),
112 rarprecv, &rbuf.data, sizeof(rbuf.data)) < 0)
114 printf("No response for RARP request\n");
119 bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip));
121 /* XXX - Can NOT assume this is our root server! */
122 bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip));
125 /* Compute our "natural" netmask. */
126 if (IN_CLASSA(myip.s_addr))
127 netmask = IN_CLASSA_NET;
128 else if (IN_CLASSB(myip.s_addr))
129 netmask = IN_CLASSB_NET;
131 netmask = IN_CLASSC_NET;
138 * Broadcast a RARP request (i.e. who knows who I am)
141 rarpsend(d, pkt, len)
142 register struct iodesc *d;
149 printf("rarpsend: called\n");
152 return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP));
156 * Returns 0 if this is the packet we're waiting for
157 * else -1 (and errno == 0)
160 rarprecv(d, pkt, len, tleft)
161 register struct iodesc *d;
167 register struct ether_arp *ap;
168 u_int16_t etype; /* host order */
172 printf("rarprecv: ");
175 n = readether(d, pkt, len, tleft, &etype);
177 if (n == -1 || n < sizeof(struct ether_arp)) {
180 printf("bad len=%d\n", n);
185 if (etype != ETHERTYPE_REVARP) {
188 printf("bad type=0x%x\n", etype);
193 ap = (struct ether_arp *)pkt;
194 if (ap->arp_hrd != htons(ARPHRD_ETHER) ||
195 ap->arp_pro != htons(ETHERTYPE_IP) ||
196 ap->arp_hln != sizeof(ap->arp_sha) ||
197 ap->arp_pln != sizeof(ap->arp_spa) )
201 printf("bad hrd/pro/hln/pln\n");
206 if (ap->arp_op != htons(ARPOP_REVREPLY)) {
209 printf("bad op=0x%x\n", ntohs(ap->arp_op));
214 /* Is the reply for our Ethernet address? */
215 if (bcmp(ap->arp_tha, d->myea, 6)) {
218 printf("unwanted address\n");
223 /* We have our answer. */