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. 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 #include <sys/param.h>
40 #include <sys/socket.h>
42 #include <netinet/in.h>
43 #include <netinet/if_ether.h>
45 #include <netinet/in_systm.h>
54 static ssize_t rarpsend(struct iodesc *, void *, size_t);
55 static ssize_t rarprecv(struct iodesc *, void **, void **, time_t, void *);
58 * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
61 rarp_getipaddress(int sock)
67 u_char header[ETHER_SIZE];
70 u_char pad[18]; /* 60 - sizeof(arp) */
76 printf("rarp: socket=%d\n", sock);
78 if (!(d = socktodesc(sock))) {
79 printf("rarp: bad socket. %d\n", sock);
84 printf("rarp: d=%lx\n", (long)d);
87 bzero((char*)&wbuf.data, sizeof(wbuf.data));
89 ap->arp_hrd = htons(ARPHRD_ETHER);
90 ap->arp_pro = htons(ETHERTYPE_IP);
91 ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */
92 ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */
93 ap->arp_op = htons(ARPOP_REVREQUEST);
94 bcopy(d->myea, ap->arp_sha, 6);
95 bcopy(d->myea, ap->arp_tha, 6);
99 rarpsend, &wbuf.data, sizeof(wbuf.data),
100 rarprecv, &pkt, (void *)&ap, NULL) < 0) {
101 printf("No response for RARP request\n");
105 bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip));
107 /* XXX - Can NOT assume this is our root server! */
108 bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip));
112 /* Compute our "natural" netmask. */
113 if (IN_CLASSA(myip.s_addr))
114 netmask = IN_CLASSA_NET;
115 else if (IN_CLASSB(myip.s_addr))
116 netmask = IN_CLASSB_NET;
118 netmask = IN_CLASSC_NET;
125 * Broadcast a RARP request (i.e. who knows who I am)
128 rarpsend(struct iodesc *d, void *pkt, size_t len)
133 printf("rarpsend: called\n");
136 return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP));
140 * Returns 0 if this is the packet we're waiting for
141 * else -1 (and errno == 0)
144 rarprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft,
148 struct ether_arp *ap;
150 uint16_t etype; /* host order */
154 printf("rarprecv: ");
157 n = readether(d, &ptr, (void **)&ap, tleft, &etype);
159 if (n == -1 || n < sizeof(struct ether_arp)) {
162 printf("bad len=%zd\n", n);
168 if (etype != ETHERTYPE_REVARP) {
171 printf("bad type=0x%x\n", etype);
177 if (ap->arp_hrd != htons(ARPHRD_ETHER) ||
178 ap->arp_pro != htons(ETHERTYPE_IP) ||
179 ap->arp_hln != sizeof(ap->arp_sha) ||
180 ap->arp_pln != sizeof(ap->arp_spa) )
184 printf("bad hrd/pro/hln/pln\n");
190 if (ap->arp_op != htons(ARPOP_REVREPLY)) {
193 printf("bad op=0x%x\n", ntohs(ap->arp_op));
199 /* Is the reply for our Ethernet address? */
200 if (bcmp(ap->arp_tha, d->myea, 6)) {
203 printf("unwanted address\n");
209 /* We have our answer. */