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 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL)
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
41 #include <sys/param.h>
42 #include <sys/socket.h>
44 #include <netinet/in.h>
45 #include <netinet/if_ether.h>
47 #include <netinet/in_systm.h>
56 static ssize_t rarpsend(struct iodesc *, void *, size_t);
57 static ssize_t rarprecv(struct iodesc *, void *, size_t, time_t);
60 * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
63 rarp_getipaddress(sock)
69 u_char header[ETHER_SIZE];
72 u_char pad[18]; /* 60 - sizeof(arp) */
76 u_char header[ETHER_SIZE];
79 u_char pad[24]; /* extra space */
85 printf("rarp: socket=%d\n", sock);
87 if (!(d = socktodesc(sock))) {
88 printf("rarp: bad socket. %d\n", sock);
93 printf("rarp: d=%x\n", (u_int)d);
96 bzero((char*)&wbuf.data, sizeof(wbuf.data));
98 ap->arp_hrd = htons(ARPHRD_ETHER);
99 ap->arp_pro = htons(ETHERTYPE_IP);
100 ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */
101 ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */
102 ap->arp_op = htons(ARPOP_REVREQUEST);
103 bcopy(d->myea, ap->arp_sha, 6);
104 bcopy(d->myea, ap->arp_tha, 6);
107 rarpsend, &wbuf.data, sizeof(wbuf.data),
108 rarprecv, &rbuf.data, sizeof(rbuf.data)) < 0)
110 printf("No response for RARP request\n");
115 bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip));
117 /* XXX - Can NOT assume this is our root server! */
118 bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip));
121 /* Compute our "natural" netmask. */
122 if (IN_CLASSA(myip.s_addr))
123 netmask = IN_CLASSA_NET;
124 else if (IN_CLASSB(myip.s_addr))
125 netmask = IN_CLASSB_NET;
127 netmask = IN_CLASSC_NET;
134 * Broadcast a RARP request (i.e. who knows who I am)
137 rarpsend(d, pkt, len)
145 printf("rarpsend: called\n");
148 return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP));
152 * Returns 0 if this is the packet we're waiting for
153 * else -1 (and errno == 0)
156 rarprecv(d, pkt, len, tleft)
163 struct ether_arp *ap;
164 u_int16_t etype; /* host order */
168 printf("rarprecv: ");
171 n = readether(d, pkt, len, tleft, &etype);
173 if (n == -1 || n < sizeof(struct ether_arp)) {
176 printf("bad len=%d\n", n);
181 if (etype != ETHERTYPE_REVARP) {
184 printf("bad type=0x%x\n", etype);
189 ap = (struct ether_arp *)pkt;
190 if (ap->arp_hrd != htons(ARPHRD_ETHER) ||
191 ap->arp_pro != htons(ETHERTYPE_IP) ||
192 ap->arp_hln != sizeof(ap->arp_sha) ||
193 ap->arp_pln != sizeof(ap->arp_spa) )
197 printf("bad hrd/pro/hln/pln\n");
202 if (ap->arp_op != htons(ARPOP_REVREPLY)) {
205 printf("bad op=0x%x\n", ntohs(ap->arp_op));
210 /* Is the reply for our Ethernet address? */
211 if (bcmp(ap->arp_tha, d->myea, 6)) {
214 printf("unwanted address\n");
219 /* We have our answer. */