1*22028508SToomas Soome /* $NetBSD: rarp.c,v 1.16 1997/07/07 15:52:52 drochner Exp $ */
2*22028508SToomas Soome
3*22028508SToomas Soome /*
4*22028508SToomas Soome * Copyright (c) 1992 Regents of the University of California.
5*22028508SToomas Soome * All rights reserved.
6*22028508SToomas Soome *
7*22028508SToomas Soome * This software was developed by the Computer Systems Engineering group
8*22028508SToomas Soome * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
9*22028508SToomas Soome * contributed to Berkeley.
10*22028508SToomas Soome *
11*22028508SToomas Soome * Redistribution and use in source and binary forms, with or without
12*22028508SToomas Soome * modification, are permitted provided that the following conditions
13*22028508SToomas Soome * are met:
14*22028508SToomas Soome * 1. Redistributions of source code must retain the above copyright
15*22028508SToomas Soome * notice, this list of conditions and the following disclaimer.
16*22028508SToomas Soome * 2. Redistributions in binary form must reproduce the above copyright
17*22028508SToomas Soome * notice, this list of conditions and the following disclaimer in the
18*22028508SToomas Soome * documentation and/or other materials provided with the distribution.
19*22028508SToomas Soome * 3. Neither the name of the University nor the names of its contributors
20*22028508SToomas Soome * may be used to endorse or promote products derived from this software
21*22028508SToomas Soome * without specific prior written permission.
22*22028508SToomas Soome *
23*22028508SToomas Soome * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24*22028508SToomas Soome * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25*22028508SToomas Soome * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26*22028508SToomas Soome * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27*22028508SToomas Soome * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28*22028508SToomas Soome * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29*22028508SToomas Soome * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30*22028508SToomas Soome * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31*22028508SToomas Soome * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32*22028508SToomas Soome * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33*22028508SToomas Soome * SUCH DAMAGE.
34*22028508SToomas Soome *
35*22028508SToomas Soome * @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL)
36*22028508SToomas Soome */
37*22028508SToomas Soome
38*22028508SToomas Soome #include <sys/cdefs.h>
39*22028508SToomas Soome
40*22028508SToomas Soome #include <sys/param.h>
41*22028508SToomas Soome #include <sys/socket.h>
42*22028508SToomas Soome #include <net/if.h>
43*22028508SToomas Soome #include <netinet/in.h>
44*22028508SToomas Soome #include <netinet/if_ether.h>
45*22028508SToomas Soome
46*22028508SToomas Soome #include <netinet/in_systm.h>
47*22028508SToomas Soome
48*22028508SToomas Soome #include <string.h>
49*22028508SToomas Soome
50*22028508SToomas Soome #include "stand.h"
51*22028508SToomas Soome #include "net.h"
52*22028508SToomas Soome #include "netif.h"
53*22028508SToomas Soome
54*22028508SToomas Soome
55*22028508SToomas Soome static ssize_t rarpsend(struct iodesc *, void *, size_t);
56*22028508SToomas Soome static ssize_t rarprecv(struct iodesc *, void **, void **, time_t, void *);
57*22028508SToomas Soome
58*22028508SToomas Soome /*
59*22028508SToomas Soome * Ethernet (Reverse) Address Resolution Protocol (see RFC 903, and 826).
60*22028508SToomas Soome */
61*22028508SToomas Soome int
rarp_getipaddress(int sock)62*22028508SToomas Soome rarp_getipaddress(int sock)
63*22028508SToomas Soome {
64*22028508SToomas Soome struct iodesc *d;
65*22028508SToomas Soome struct ether_arp *ap;
66*22028508SToomas Soome void *pkt;
67*22028508SToomas Soome struct {
68*22028508SToomas Soome u_char header[ETHER_SIZE];
69*22028508SToomas Soome struct {
70*22028508SToomas Soome struct ether_arp arp;
71*22028508SToomas Soome u_char pad[18]; /* 60 - sizeof(arp) */
72*22028508SToomas Soome } data;
73*22028508SToomas Soome } wbuf;
74*22028508SToomas Soome
75*22028508SToomas Soome #ifdef RARP_DEBUG
76*22028508SToomas Soome if (debug)
77*22028508SToomas Soome printf("rarp: socket=%d\n", sock);
78*22028508SToomas Soome #endif
79*22028508SToomas Soome if (!(d = socktodesc(sock))) {
80*22028508SToomas Soome printf("rarp: bad socket. %d\n", sock);
81*22028508SToomas Soome return (-1);
82*22028508SToomas Soome }
83*22028508SToomas Soome #ifdef RARP_DEBUG
84*22028508SToomas Soome if (debug)
85*22028508SToomas Soome printf("rarp: d=%x\n", (u_int)d);
86*22028508SToomas Soome #endif
87*22028508SToomas Soome
88*22028508SToomas Soome bzero((char*)&wbuf.data, sizeof(wbuf.data));
89*22028508SToomas Soome ap = &wbuf.data.arp;
90*22028508SToomas Soome ap->arp_hrd = htons(ARPHRD_ETHER);
91*22028508SToomas Soome ap->arp_pro = htons(ETHERTYPE_IP);
92*22028508SToomas Soome ap->arp_hln = sizeof(ap->arp_sha); /* hardware address length */
93*22028508SToomas Soome ap->arp_pln = sizeof(ap->arp_spa); /* protocol address length */
94*22028508SToomas Soome ap->arp_op = htons(ARPOP_REVREQUEST);
95*22028508SToomas Soome bcopy(d->myea, ap->arp_sha, 6);
96*22028508SToomas Soome bcopy(d->myea, ap->arp_tha, 6);
97*22028508SToomas Soome pkt = NULL;
98*22028508SToomas Soome
99*22028508SToomas Soome if (sendrecv(d,
100*22028508SToomas Soome rarpsend, &wbuf.data, sizeof(wbuf.data),
101*22028508SToomas Soome rarprecv, &pkt, (void *)&ap, NULL) < 0) {
102*22028508SToomas Soome printf("No response for RARP request\n");
103*22028508SToomas Soome return (-1);
104*22028508SToomas Soome }
105*22028508SToomas Soome
106*22028508SToomas Soome bcopy(ap->arp_tpa, (char *)&myip, sizeof(myip));
107*22028508SToomas Soome #if 0
108*22028508SToomas Soome /* XXX - Can NOT assume this is our root server! */
109*22028508SToomas Soome bcopy(ap->arp_spa, (char *)&rootip, sizeof(rootip));
110*22028508SToomas Soome #endif
111*22028508SToomas Soome free(pkt);
112*22028508SToomas Soome
113*22028508SToomas Soome /* Compute our "natural" netmask. */
114*22028508SToomas Soome if (IN_CLASSA(myip.s_addr))
115*22028508SToomas Soome netmask = IN_CLASSA_NET;
116*22028508SToomas Soome else if (IN_CLASSB(myip.s_addr))
117*22028508SToomas Soome netmask = IN_CLASSB_NET;
118*22028508SToomas Soome else
119*22028508SToomas Soome netmask = IN_CLASSC_NET;
120*22028508SToomas Soome
121*22028508SToomas Soome d->myip = myip;
122*22028508SToomas Soome return (0);
123*22028508SToomas Soome }
124*22028508SToomas Soome
125*22028508SToomas Soome /*
126*22028508SToomas Soome * Broadcast a RARP request (i.e. who knows who I am)
127*22028508SToomas Soome */
128*22028508SToomas Soome static ssize_t
rarpsend(struct iodesc * d,void * pkt,size_t len)129*22028508SToomas Soome rarpsend(struct iodesc *d, void *pkt, size_t len)
130*22028508SToomas Soome {
131*22028508SToomas Soome
132*22028508SToomas Soome #ifdef RARP_DEBUG
133*22028508SToomas Soome if (debug)
134*22028508SToomas Soome printf("rarpsend: called\n");
135*22028508SToomas Soome #endif
136*22028508SToomas Soome
137*22028508SToomas Soome return (sendether(d, pkt, len, bcea, ETHERTYPE_REVARP));
138*22028508SToomas Soome }
139*22028508SToomas Soome
140*22028508SToomas Soome /*
141*22028508SToomas Soome * Returns 0 if this is the packet we're waiting for
142*22028508SToomas Soome * else -1 (and errno == 0)
143*22028508SToomas Soome */
144*22028508SToomas Soome static ssize_t
rarprecv(struct iodesc * d,void ** pkt,void ** payload,time_t tleft,void * extra __unused)145*22028508SToomas Soome rarprecv(struct iodesc *d, void **pkt, void **payload, time_t tleft,
146*22028508SToomas Soome void *extra __unused)
147*22028508SToomas Soome {
148*22028508SToomas Soome ssize_t n;
149*22028508SToomas Soome struct ether_arp *ap;
150*22028508SToomas Soome void *ptr = NULL;
151*22028508SToomas Soome uint16_t etype; /* host order */
152*22028508SToomas Soome
153*22028508SToomas Soome #ifdef RARP_DEBUG
154*22028508SToomas Soome if (debug)
155*22028508SToomas Soome printf("rarprecv: ");
156*22028508SToomas Soome #endif
157*22028508SToomas Soome
158*22028508SToomas Soome n = readether(d, &ptr, (void **)&ap, tleft, &etype);
159*22028508SToomas Soome errno = 0; /* XXX */
160*22028508SToomas Soome if (n == -1 || n < sizeof(struct ether_arp)) {
161*22028508SToomas Soome #ifdef RARP_DEBUG
162*22028508SToomas Soome if (debug)
163*22028508SToomas Soome printf("bad len=%d\n", n);
164*22028508SToomas Soome #endif
165*22028508SToomas Soome free(ptr);
166*22028508SToomas Soome return (-1);
167*22028508SToomas Soome }
168*22028508SToomas Soome
169*22028508SToomas Soome if (etype != ETHERTYPE_REVARP) {
170*22028508SToomas Soome #ifdef RARP_DEBUG
171*22028508SToomas Soome if (debug)
172*22028508SToomas Soome printf("bad type=0x%x\n", etype);
173*22028508SToomas Soome #endif
174*22028508SToomas Soome free(ptr);
175*22028508SToomas Soome return (-1);
176*22028508SToomas Soome }
177*22028508SToomas Soome
178*22028508SToomas Soome if (ap->arp_hrd != htons(ARPHRD_ETHER) ||
179*22028508SToomas Soome ap->arp_pro != htons(ETHERTYPE_IP) ||
180*22028508SToomas Soome ap->arp_hln != sizeof(ap->arp_sha) ||
181*22028508SToomas Soome ap->arp_pln != sizeof(ap->arp_spa) )
182*22028508SToomas Soome {
183*22028508SToomas Soome #ifdef RARP_DEBUG
184*22028508SToomas Soome if (debug)
185*22028508SToomas Soome printf("bad hrd/pro/hln/pln\n");
186*22028508SToomas Soome #endif
187*22028508SToomas Soome free(ptr);
188*22028508SToomas Soome return (-1);
189*22028508SToomas Soome }
190*22028508SToomas Soome
191*22028508SToomas Soome if (ap->arp_op != htons(ARPOP_REVREPLY)) {
192*22028508SToomas Soome #ifdef RARP_DEBUG
193*22028508SToomas Soome if (debug)
194*22028508SToomas Soome printf("bad op=0x%x\n", ntohs(ap->arp_op));
195*22028508SToomas Soome #endif
196*22028508SToomas Soome free(ptr);
197*22028508SToomas Soome return (-1);
198*22028508SToomas Soome }
199*22028508SToomas Soome
200*22028508SToomas Soome /* Is the reply for our Ethernet address? */
201*22028508SToomas Soome if (bcmp(ap->arp_tha, d->myea, 6)) {
202*22028508SToomas Soome #ifdef RARP_DEBUG
203*22028508SToomas Soome if (debug)
204*22028508SToomas Soome printf("unwanted address\n");
205*22028508SToomas Soome #endif
206*22028508SToomas Soome free(ptr);
207*22028508SToomas Soome return (-1);
208*22028508SToomas Soome }
209*22028508SToomas Soome
210*22028508SToomas Soome /* We have our answer. */
211*22028508SToomas Soome #ifdef RARP_DEBUG
212*22028508SToomas Soome if (debug)
213*22028508SToomas Soome printf("got it\n");
214*22028508SToomas Soome #endif
215*22028508SToomas Soome *pkt = ptr;
216*22028508SToomas Soome *payload = ap;
217*22028508SToomas Soome return (n);
218*22028508SToomas Soome }
219