Use CSTD and remove local CSTD settings which are no longer needed.
[dragonfly.git] / lib / libstand / arp.c
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1/* $NetBSD: arp.c,v 1.18 1997/07/07 15:52:49 drochner Exp $ */
2
3/*
4 * Copyright (c) 1992 Regents of the University of California.
5 * All rights reserved.
6 *
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.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
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.
26 *
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
37 * SUCH DAMAGE.
38 *
39 * @(#) Header: arp.c,v 1.5 93/07/15 05:52:26 leres Exp (LBL)
ff2aef30 40 * $DragonFly: src/lib/libstand/arp.c,v 1.4 2005/12/11 02:27:26 swildner Exp $
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41 */
42
47883879 43#include <sys/param.h>
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44#include <sys/socket.h>
45#include <net/if.h>
46#include <netinet/in.h>
47#include <netinet/if_ether.h>
48
49#include <netinet/in_systm.h>
50
51#include <string.h>
52
53#include "stand.h"
54#include "net.h"
55
56/* Cache stuff */
57#define ARP_NUM 8 /* need at most 3 arp entries */
58
59struct arp_list {
60 struct in_addr addr;
61 u_char ea[6];
62} arp_list[ARP_NUM] = {
63 /* XXX - net order `INADDR_BROADCAST' must be a constant */
64 { {0xffffffff}, BA }
65};
66int arp_num = 1;
67
68/* Local forwards */
69static ssize_t arpsend(struct iodesc *, void *, size_t);
70static ssize_t arprecv(struct iodesc *, void *, size_t, time_t);
71
72/* Broadcast an ARP packet, asking who has addr on interface d */
73u_char *
ff2aef30 74arpwhohas(struct iodesc *d, struct in_addr addr)
984263bc 75{
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76 int i;
77 struct ether_arp *ah;
78 struct arp_list *al;
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79 struct {
80 struct ether_header eh;
81 struct {
82 struct ether_arp arp;
83 u_char pad[18]; /* 60 - sizeof(...) */
84 } data;
85 } wbuf;
86 struct {
87 struct ether_header eh;
88 struct {
89 struct ether_arp arp;
90 u_char pad[24]; /* extra space */
91 } data;
92 } rbuf;
93
94 /* Try for cached answer first */
95 for (i = 0, al = arp_list; i < arp_num; ++i, ++al)
96 if (addr.s_addr == al->addr.s_addr)
97 return (al->ea);
98
99 /* Don't overflow cache */
100 if (arp_num > ARP_NUM - 1) {
101 arp_num = 1; /* recycle */
102 printf("arpwhohas: overflowed arp_list!\n");
103 }
104
105#ifdef ARP_DEBUG
106 if (debug)
107 printf("arpwhohas: send request for %s\n", inet_ntoa(addr));
108#endif
109
110 bzero((char*)&wbuf.data, sizeof(wbuf.data));
111 ah = &wbuf.data.arp;
112 ah->arp_hrd = htons(ARPHRD_ETHER);
113 ah->arp_pro = htons(ETHERTYPE_IP);
114 ah->arp_hln = sizeof(ah->arp_sha); /* hardware address length */
115 ah->arp_pln = sizeof(ah->arp_spa); /* protocol address length */
116 ah->arp_op = htons(ARPOP_REQUEST);
117 MACPY(d->myea, ah->arp_sha);
118 bcopy(&d->myip, ah->arp_spa, sizeof(ah->arp_spa));
119 /* Leave zeros in arp_tha */
120 bcopy(&addr, ah->arp_tpa, sizeof(ah->arp_tpa));
121
122 /* Store ip address in cache (incomplete entry). */
123 al->addr = addr;
124
125 i = sendrecv(d,
126 arpsend, &wbuf.data, sizeof(wbuf.data),
127 arprecv, &rbuf.data, sizeof(rbuf.data));
128 if (i == -1) {
129 panic("arp: no response for %s\n",
130 inet_ntoa(addr));
131 }
132
133 /* Store ethernet address in cache */
134 ah = &rbuf.data.arp;
135#ifdef ARP_DEBUG
136 if (debug) {
137 printf("arp: response from %s\n",
138 ether_sprintf(rbuf.eh.ether_shost));
139 printf("arp: cacheing %s --> %s\n",
140 inet_ntoa(addr), ether_sprintf(ah->arp_sha));
141 }
142#endif
143 MACPY(ah->arp_sha, al->ea);
144 ++arp_num;
145
146 return (al->ea);
147}
148
149static ssize_t
ff2aef30 150arpsend(struct iodesc *d, void *pkt, size_t len)
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151{
152
153#ifdef ARP_DEBUG
154 if (debug)
155 printf("arpsend: called\n");
156#endif
157
158 return (sendether(d, pkt, len, bcea, ETHERTYPE_ARP));
159}
160
161/*
162 * Returns 0 if this is the packet we're waiting for
163 * else -1 (and errno == 0)
164 */
165static ssize_t
ff2aef30 166arprecv(struct iodesc *d, void *pkt, size_t len, time_t tleft)
984263bc 167{
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168 ssize_t n;
169 struct ether_arp *ah;
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170 u_int16_t etype; /* host order */
171
172#ifdef ARP_DEBUG
173 if (debug)
174 printf("arprecv: ");
175#endif
176
177 n = readether(d, pkt, len, tleft, &etype);
178 errno = 0; /* XXX */
179 if (n == -1 || n < sizeof(struct ether_arp)) {
180#ifdef ARP_DEBUG
181 if (debug)
182 printf("bad len=%d\n", n);
183#endif
184 return (-1);
185 }
186
187 if (etype != ETHERTYPE_ARP) {
188#ifdef ARP_DEBUG
189 if (debug)
190 printf("not arp type=%d\n", etype);
191#endif
192 return (-1);
193 }
194
195 /* Ethernet address now checked in readether() */
196
197 ah = (struct ether_arp *)pkt;
198 if (ah->arp_hrd != htons(ARPHRD_ETHER) ||
199 ah->arp_pro != htons(ETHERTYPE_IP) ||
200 ah->arp_hln != sizeof(ah->arp_sha) ||
201 ah->arp_pln != sizeof(ah->arp_spa) )
202 {
203#ifdef ARP_DEBUG
204 if (debug)
205 printf("bad hrd/pro/hln/pln\n");
206#endif
207 return (-1);
208 }
209
210 if (ah->arp_op == htons(ARPOP_REQUEST)) {
211#ifdef ARP_DEBUG
212 if (debug)
213 printf("is request\n");
214#endif
215 arp_reply(d, ah);
216 return (-1);
217 }
218
219 if (ah->arp_op != htons(ARPOP_REPLY)) {
220#ifdef ARP_DEBUG
221 if (debug)
222 printf("not ARP reply\n");
223#endif
224 return (-1);
225 }
226
227 /* Is the reply from the source we want? */
228 if (bcmp(&arp_list[arp_num].addr,
229 ah->arp_spa, sizeof(ah->arp_spa)))
230 {
231#ifdef ARP_DEBUG
232 if (debug)
233 printf("unwanted address\n");
234#endif
235 return (-1);
236 }
237 /* We don't care who the reply was sent to. */
238
239 /* We have our answer. */
240#ifdef ARP_DEBUG
241 if (debug)
242 printf("got it\n");
243#endif
244 return (n);
245}
246
247/*
248 * Convert an ARP request into a reply and send it.
249 * Notes: Re-uses buffer. Pad to length = 46.
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250 *
251 * Parameters:
252 * pkt: the request
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253 */
254void
ff2aef30 255arp_reply(struct iodesc *d, void *pkt)
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256{
257 struct ether_arp *arp = pkt;
258
259 if (arp->arp_hrd != htons(ARPHRD_ETHER) ||
260 arp->arp_pro != htons(ETHERTYPE_IP) ||
261 arp->arp_hln != sizeof(arp->arp_sha) ||
262 arp->arp_pln != sizeof(arp->arp_spa) )
263 {
264#ifdef ARP_DEBUG
265 if (debug)
266 printf("arp_reply: bad hrd/pro/hln/pln\n");
267#endif
268 return;
269 }
270
271 if (arp->arp_op != htons(ARPOP_REQUEST)) {
272#ifdef ARP_DEBUG
273 if (debug)
274 printf("arp_reply: not request!\n");
275#endif
276 return;
277 }
278
279 /* If we are not the target, ignore the request. */
280 if (bcmp(arp->arp_tpa, &d->myip, sizeof(arp->arp_tpa)))
281 return;
282
283#ifdef ARP_DEBUG
284 if (debug) {
285 printf("arp_reply: to %s\n", ether_sprintf(arp->arp_sha));
286 }
287#endif
288
289 arp->arp_op = htons(ARPOP_REPLY);
290 /* source becomes target */
291 bcopy(arp->arp_sha, arp->arp_tha, sizeof(arp->arp_tha));
292 bcopy(arp->arp_spa, arp->arp_tpa, sizeof(arp->arp_tpa));
293 /* here becomes source */
294 bcopy(d->myea, arp->arp_sha, sizeof(arp->arp_sha));
295 bcopy(&d->myip, arp->arp_spa, sizeof(arp->arp_spa));
296
297 /*
298 * No need to get fancy here. If the send fails, the
299 * requestor will just ask again.
300 */
301 (void) sendether(d, pkt, sizeof(*arp) + 18,
302 arp->arp_tha, ETHERTYPE_ARP);
303}