xref: /netbsd-src/sys/netatalk/aarp.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: aarp.c,v 1.14 2003/06/23 11:02:12 martin Exp $	*/
2 
3 /*
4  * Copyright (c) 1990,1991 Regents of The University of Michigan.
5  * All Rights Reserved.
6  *
7  * Permission to use, copy, modify, and distribute this software and
8  * its documentation for any purpose and without fee is hereby granted,
9  * provided that the above copyright notice appears in all copies and
10  * that both that copyright notice and this permission notice appear
11  * in supporting documentation, and that the name of The University
12  * of Michigan not be used in advertising or publicity pertaining to
13  * distribution of the software without specific, written prior
14  * permission. This software is supplied as is without expressed or
15  * implied warranties of any kind.
16  *
17  * This product includes software developed by the University of
18  * California, Berkeley and its contributors.
19  *
20  *	Research Systems Unix Group
21  *	The University of Michigan
22  *	c/o Wesley Craig
23  *	535 W. William Street
24  *	Ann Arbor, Michigan
25  *	+1-313-764-2278
26  *	netatalk@umich.edu
27  */
28 
29 #include <sys/cdefs.h>
30 __KERNEL_RCSID(0, "$NetBSD: aarp.c,v 1.14 2003/06/23 11:02:12 martin Exp $");
31 
32 #include "opt_mbuftrace.h"
33 
34 #include <sys/param.h>
35 #include <sys/socket.h>
36 #include <sys/syslog.h>
37 #include <sys/systm.h>
38 #include <sys/callout.h>
39 #include <sys/proc.h>
40 #include <sys/mbuf.h>
41 #include <sys/time.h>
42 #include <sys/kernel.h>
43 #include <net/if.h>
44 #include <net/route.h>
45 #include <net/if_ether.h>
46 #include <net/if_dl.h>
47 #include <netinet/in.h>
48 #undef s_net
49 
50 #include <netatalk/at.h>
51 #include <netatalk/at_var.h>
52 #include <netatalk/aarp.h>
53 #include <netatalk/ddp_var.h>
54 #include <netatalk/phase2.h>
55 #include <netatalk/at_extern.h>
56 
57 static struct aarptab *aarptnew __P((struct at_addr *));
58 static void aarptfree __P((struct aarptab *));
59 static void at_aarpinput __P((struct ifnet *, struct mbuf *));
60 static void aarptimer __P((void *));
61 static void aarpwhohas __P((struct ifnet *, struct sockaddr_at *));
62 
63 #define AARPTAB_BSIZ	9
64 #define AARPTAB_NB	19
65 #define AARPTAB_SIZE	(AARPTAB_BSIZ * AARPTAB_NB)
66 struct aarptab  aarptab[AARPTAB_SIZE];
67 
68 #define AARPTAB_HASH(a) \
69     ((((a).s_net << 8 ) + (a).s_node ) % AARPTAB_NB )
70 
71 #define AARPTAB_LOOK(aat,addr) { \
72     int		n; \
73     aat = &aarptab[ AARPTAB_HASH(addr) * AARPTAB_BSIZ ]; \
74     for ( n = 0; n < AARPTAB_BSIZ; n++, aat++ ) \
75 	if ( aat->aat_ataddr.s_net == (addr).s_net && \
76 	     aat->aat_ataddr.s_node == (addr).s_node ) \
77 	    break; \
78 	if ( n >= AARPTAB_BSIZ ) \
79 	    aat = 0; \
80 }
81 
82 #define AARPT_AGE	(60 * 1)
83 #define AARPT_KILLC	20
84 #define AARPT_KILLI	3
85 
86 #if !defined( __FreeBSD__ )
87 extern u_char   etherbroadcastaddr[6];
88 #endif	/* __FreeBSD__ */
89 
90 const u_char atmulticastaddr[6] = {
91 	0x09, 0x00, 0x07, 0xff, 0xff, 0xff
92 };
93 
94 const u_char at_org_code[3] = {
95 	0x08, 0x00, 0x07
96 };
97 const u_char aarp_org_code[3] = {
98 	0x00, 0x00, 0x00
99 };
100 
101 struct callout aarptimer_callout;
102 #ifdef MBUFTRACE
103 struct mowner aarp_mowner = { "atalk", "arp" };
104 #endif
105 
106 /*ARGSUSED*/
107 static void
108 aarptimer(ignored)
109 	void *ignored;
110 {
111 	struct aarptab *aat;
112 	int             i, s;
113 
114 	callout_reset(&aarptimer_callout, AARPT_AGE * hz, aarptimer, NULL);
115 	aat = aarptab;
116 	for (i = 0; i < AARPTAB_SIZE; i++, aat++) {
117 		int killtime = (aat->aat_flags & ATF_COM) ? AARPT_KILLC :
118 		    AARPT_KILLI;
119 		if (aat->aat_flags == 0 || (aat->aat_flags & ATF_PERM))
120 			continue;
121 		if (++aat->aat_timer < killtime)
122 			continue;
123 		s = splnet();
124 		aarptfree(aat);
125 		splx(s);
126 	}
127 }
128 
129 /*
130  * search through the network addresses to find one that includes the given
131  * network.. remember to take netranges into consideration.
132  */
133 struct ifaddr *
134 at_ifawithnet(sat, ifp)
135 	struct sockaddr_at *sat;
136 	struct ifnet *ifp;
137 {
138 	struct ifaddr  *ifa;
139 	struct sockaddr_at *sat2;
140 	struct netrange *nr;
141 
142 	for (ifa = ifp->if_addrlist.tqh_first; ifa;
143 	    ifa = ifa->ifa_list.tqe_next) {
144 		if (ifa->ifa_addr->sa_family != AF_APPLETALK)
145 			continue;
146 
147 		sat2 = satosat(ifa->ifa_addr);
148 		if (sat2->sat_addr.s_net == sat->sat_addr.s_net)
149 			break;
150 
151 		nr = (struct netrange *) (sat2->sat_zero);
152 		if ((nr->nr_phase == 2)
153 		    && (nr->nr_firstnet <= sat->sat_addr.s_net)
154 		    && (nr->nr_lastnet >= sat->sat_addr.s_net))
155 			break;
156 	}
157 	return ifa;
158 }
159 
160 static void
161 aarpwhohas(ifp, sat)
162 	struct ifnet *ifp;
163 	struct sockaddr_at *sat;
164 {
165 	struct mbuf    *m;
166 	struct ether_header *eh;
167 	struct ether_aarp *ea;
168 	struct at_ifaddr *aa;
169 	struct llc     *llc;
170 	struct sockaddr sa;
171 
172 	if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
173 		return;
174 
175 	MCLAIM(m, &aarp_mowner);
176 	m->m_len = sizeof(*ea);
177 	m->m_pkthdr.len = sizeof(*ea);
178 	MH_ALIGN(m, sizeof(*ea));
179 
180 	ea = mtod(m, struct ether_aarp *);
181 	bzero(ea, sizeof(*ea));
182 
183 	ea->aarp_hrd = htons(AARPHRD_ETHER);
184 	ea->aarp_pro = htons(ETHERTYPE_ATALK);
185 	ea->aarp_hln = sizeof(ea->aarp_sha);
186 	ea->aarp_pln = sizeof(ea->aarp_spu);
187 	ea->aarp_op = htons(AARPOP_REQUEST);
188 	bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
189 
190 	/*
191          * We need to check whether the output ethernet type should
192          * be phase 1 or 2. We have the interface that we'll be sending
193          * the aarp out. We need to find an AppleTalk network on that
194          * interface with the same address as we're looking for. If the
195          * net is phase 2, generate an 802.2 and SNAP header.
196          */
197 	if ((aa = (struct at_ifaddr *) at_ifawithnet(sat, ifp)) == NULL) {
198 		m_freem(m);
199 		return;
200 	}
201 	eh = (struct ether_header *) sa.sa_data;
202 
203 	if (aa->aa_flags & AFA_PHASE2) {
204 		bcopy(atmulticastaddr, eh->ether_dhost,
205 		    sizeof(eh->ether_dhost));
206 		eh->ether_type = 0;	/* if_output will treat as 802 */
207 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
208 		if (!m)
209 			return;
210 
211 		llc = mtod(m, struct llc *);
212 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
213 		llc->llc_control = LLC_UI;
214 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
215 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
216 
217 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_spnet,
218 		      sizeof(ea->aarp_spnet));
219 		bcopy(&sat->sat_addr.s_net, ea->aarp_tpnet,
220 		      sizeof(ea->aarp_tpnet));
221 		ea->aarp_spnode = AA_SAT(aa)->sat_addr.s_node;
222 		ea->aarp_tpnode = sat->sat_addr.s_node;
223 	} else {
224 		bcopy(etherbroadcastaddr, eh->ether_dhost,
225 		    sizeof(eh->ether_dhost));
226 		eh->ether_type = htons(ETHERTYPE_AARP);
227 
228 		ea->aarp_spa = AA_SAT(aa)->sat_addr.s_node;
229 		ea->aarp_tpa = sat->sat_addr.s_node;
230 	}
231 
232 #ifdef NETATALKDEBUG
233 	printf("aarp: sending request via %u.%u seaking %u.%u\n",
234 	    ntohs(AA_SAT(aa)->sat_addr.s_net), AA_SAT(aa)->sat_addr.s_node,
235 	    ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node);
236 #endif	/* NETATALKDEBUG */
237 
238 	sa.sa_len = sizeof(struct sockaddr);
239 	sa.sa_family = AF_UNSPEC;
240 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX NULL should be routing */
241 						/* information */
242 }
243 
244 int
245 aarpresolve(ifp, m, destsat, desten)
246 	struct ifnet   *ifp;
247 	struct mbuf    *m;
248 	struct sockaddr_at *destsat;
249 	u_char         *desten;
250 {
251 	struct at_ifaddr *aa;
252 	struct aarptab *aat;
253 	int             s;
254 
255 	if (at_broadcast(destsat)) {
256 		aa = (struct at_ifaddr *) at_ifawithnet(destsat, ifp);
257 		if (aa == NULL) {
258 			m_freem(m);
259 			return (0);
260 		}
261 		if (aa->aa_flags & AFA_PHASE2)
262 			bcopy(atmulticastaddr, desten,
263 			    sizeof(atmulticastaddr));
264 		else
265 			bcopy(etherbroadcastaddr, desten,
266 			    sizeof(etherbroadcastaddr));
267 		return 1;
268 	}
269 	s = splnet();
270 	AARPTAB_LOOK(aat, destsat->sat_addr);
271 	if (aat == 0) {		/* No entry */
272 		aat = aarptnew(&destsat->sat_addr);
273 		if (aat == 0)
274 			panic("aarpresolve: no free entry");
275 
276 		aat->aat_hold = m;
277 		aarpwhohas(ifp, destsat);
278 		splx(s);
279 		return 0;
280 	}
281 
282 	/* found an entry */
283 	aat->aat_timer = 0;
284 	if (aat->aat_flags & ATF_COM) {	/* entry is COMplete */
285 		bcopy(aat->aat_enaddr, desten, sizeof(aat->aat_enaddr));
286 		splx(s);
287 		return 1;
288 	}
289 
290 	/* entry has not completed */
291 	if (aat->aat_hold)
292 		m_freem(aat->aat_hold);
293 	aat->aat_hold = m;
294 	aarpwhohas(ifp, destsat);
295 	splx(s);
296 
297 	return 0;
298 }
299 
300 void
301 aarpinput(ifp, m)
302 	struct ifnet   *ifp;
303 	struct mbuf    *m;
304 {
305 	struct arphdr  *ar;
306 
307 	if (ifp->if_flags & IFF_NOARP)
308 		goto out;
309 
310 	if (m->m_len < sizeof(struct arphdr))
311 		goto out;
312 
313 	ar = mtod(m, struct arphdr *);
314 	if (ntohs(ar->ar_hrd) != AARPHRD_ETHER)
315 		goto out;
316 
317 	if (m->m_len < sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln)
318 		goto out;
319 
320 	switch (ntohs(ar->ar_pro)) {
321 	case ETHERTYPE_ATALK:
322 		at_aarpinput(ifp, m);
323 		return;
324 
325 	default:
326 		break;
327 	}
328 
329 out:
330 	m_freem(m);
331 }
332 
333 static void
334 at_aarpinput(ifp, m)
335 	struct ifnet *ifp;
336 	struct mbuf *m;
337 {
338 	struct ether_aarp *ea;
339 	struct at_ifaddr *aa;
340 	struct aarptab *aat;
341 	struct ether_header *eh;
342 	struct llc     *llc;
343 	struct sockaddr_at sat;
344 	struct sockaddr sa;
345 	struct at_addr  spa, tpa, ma;
346 	int             op;
347 	u_int16_t       net;
348 
349 	ea = mtod(m, struct ether_aarp *);
350 
351 	/* Check to see if from my hardware address */
352 	if (!bcmp(ea->aarp_sha, LLADDR(ifp->if_sadl), sizeof(ea->aarp_sha))) {
353 		m_freem(m);
354 		return;
355 	}
356 	op = ntohs(ea->aarp_op);
357 	bcopy(ea->aarp_tpnet, &net, sizeof(net));
358 
359 	if (net != 0) {		/* should be ATADDR_ANYNET? */
360 		sat.sat_len = sizeof(struct sockaddr_at);
361 		sat.sat_family = AF_APPLETALK;
362 		sat.sat_addr.s_net = net;
363 		aa = (struct at_ifaddr *) at_ifawithnet(&sat, ifp);
364 		if (aa == NULL) {
365 			m_freem(m);
366 			return;
367 		}
368 		bcopy(ea->aarp_spnet, &spa.s_net, sizeof(spa.s_net));
369 		bcopy(ea->aarp_tpnet, &tpa.s_net, sizeof(tpa.s_net));
370 	} else {
371 		/*
372 		 * Since we don't know the net, we just look for the first
373 		 * phase 1 address on the interface.
374 		 */
375 		for (aa = (struct at_ifaddr *) ifp->if_addrlist.tqh_first; aa;
376 		    aa = (struct at_ifaddr *) aa->aa_ifa.ifa_list.tqe_next) {
377 			if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
378 			    (aa->aa_flags & AFA_PHASE2) == 0)
379 				break;
380 		}
381 		if (aa == NULL) {
382 			m_freem(m);
383 			return;
384 		}
385 		tpa.s_net = spa.s_net = AA_SAT(aa)->sat_addr.s_net;
386 	}
387 
388 	spa.s_node = ea->aarp_spnode;
389 	tpa.s_node = ea->aarp_tpnode;
390 	ma.s_net = AA_SAT(aa)->sat_addr.s_net;
391 	ma.s_node = AA_SAT(aa)->sat_addr.s_node;
392 
393 	/*
394          * This looks like it's from us.
395          */
396 	if (spa.s_net == ma.s_net && spa.s_node == ma.s_node) {
397 		if (aa->aa_flags & AFA_PROBING) {
398 			/*
399 		         * We're probing, someone either responded to our
400 			 * probe, or probed for the same address we'd like
401 			 * to use. Change the address we're probing for.
402 		         */
403 			callout_stop(&aa->aa_probe_ch);
404 			wakeup(aa);
405 			m_freem(m);
406 			return;
407 		} else if (op != AARPOP_PROBE) {
408 			/*
409 		         * This is not a probe, and we're not probing.
410 			 * This means that someone's saying they have the same
411 			 * source address as the one we're using. Get upset...
412 		         */
413 			log(LOG_ERR, "aarp: duplicate AT address!! %s\n",
414 			    ether_sprintf(ea->aarp_sha));
415 			m_freem(m);
416 			return;
417 		}
418 	}
419 	AARPTAB_LOOK(aat, spa);
420 	if (aat) {
421 		if (op == AARPOP_PROBE) {
422 			/*
423 		         * Someone's probing for spa, deallocate the one we've
424 			 * got, so that if the prober keeps the address, we'll
425 			 * be able to arp for him.
426 		         */
427 			aarptfree(aat);
428 			m_freem(m);
429 			return;
430 		}
431 		bcopy(ea->aarp_sha, aat->aat_enaddr, sizeof(ea->aarp_sha));
432 		aat->aat_flags |= ATF_COM;
433 		if (aat->aat_hold) {
434 			sat.sat_len = sizeof(struct sockaddr_at);
435 			sat.sat_family = AF_APPLETALK;
436 			sat.sat_addr = spa;
437 			(*ifp->if_output)(ifp, aat->aat_hold,
438 			    (struct sockaddr *) & sat, NULL);	/* XXX */
439 			aat->aat_hold = 0;
440 		}
441 	}
442 	if (aat == 0 && tpa.s_net == ma.s_net && tpa.s_node == ma.s_node
443 	    && op != AARPOP_PROBE) {
444 		if ((aat = aarptnew(&spa)) != NULL) {
445 			bcopy(ea->aarp_sha, aat->aat_enaddr,
446 			    sizeof(ea->aarp_sha));
447 			aat->aat_flags |= ATF_COM;
448 		}
449 	}
450 	/*
451          * Don't respond to responses, and never respond if we're
452          * still probing.
453          */
454 	if (tpa.s_net != ma.s_net || tpa.s_node != ma.s_node ||
455 	    op == AARPOP_RESPONSE || (aa->aa_flags & AFA_PROBING)) {
456 		m_freem(m);
457 		return;
458 	}
459 	bcopy(ea->aarp_sha, ea->aarp_tha, sizeof(ea->aarp_sha));
460 	bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
461 
462 	/* XXX */
463 	eh = (struct ether_header *) sa.sa_data;
464 	bcopy(ea->aarp_tha, eh->ether_dhost, sizeof(eh->ether_dhost));
465 
466 	if (aa->aa_flags & AFA_PHASE2) {
467 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
468 		if (m == NULL)
469 			return;
470 
471 		llc = mtod(m, struct llc *);
472 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
473 		llc->llc_control = LLC_UI;
474 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
475 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
476 
477 		bcopy(ea->aarp_spnet, ea->aarp_tpnet, sizeof(ea->aarp_tpnet));
478 		bcopy(&ma.s_net, ea->aarp_spnet, sizeof(ea->aarp_spnet));
479 		eh->ether_type = 0;	/* if_output will treat as 802 */
480 	} else {
481 		eh->ether_type = htons(ETHERTYPE_AARP);
482 	}
483 
484 	ea->aarp_tpnode = ea->aarp_spnode;
485 	ea->aarp_spnode = ma.s_node;
486 	ea->aarp_op = htons(AARPOP_RESPONSE);
487 
488 	sa.sa_len = sizeof(struct sockaddr);
489 	sa.sa_family = AF_UNSPEC;
490 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX */
491 	return;
492 }
493 
494 static void
495 aarptfree(aat)
496 	struct aarptab *aat;
497 {
498 
499 	if (aat->aat_hold)
500 		m_freem(aat->aat_hold);
501 	aat->aat_hold = 0;
502 	aat->aat_timer = aat->aat_flags = 0;
503 	aat->aat_ataddr.s_net = 0;
504 	aat->aat_ataddr.s_node = 0;
505 }
506 
507 static struct aarptab *
508 aarptnew(addr)
509 	struct at_addr *addr;
510 {
511 	int             n;
512 	int             oldest = -1;
513 	struct aarptab *aat, *aato = NULL;
514 	static int      first = 1;
515 
516 	if (first) {
517 		first = 0;
518 		callout_init(&aarptimer_callout);
519 		callout_reset(&aarptimer_callout, hz, aarptimer, NULL);
520 		MOWNER_ATTACH(&aarp_mowner);
521 	}
522 	aat = &aarptab[AARPTAB_HASH(*addr) * AARPTAB_BSIZ];
523 	for (n = 0; n < AARPTAB_BSIZ; n++, aat++) {
524 		if (aat->aat_flags == 0)
525 			goto out;
526 		if (aat->aat_flags & ATF_PERM)
527 			continue;
528 		if ((int) aat->aat_timer > oldest) {
529 			oldest = aat->aat_timer;
530 			aato = aat;
531 		}
532 	}
533 	if (aato == NULL)
534 		return (NULL);
535 	aat = aato;
536 	aarptfree(aat);
537 out:
538 	aat->aat_ataddr = *addr;
539 	aat->aat_flags = ATF_INUSE;
540 	return (aat);
541 }
542 
543 
544 void
545 aarpprobe(arp)
546 	void *arp;
547 {
548 	struct mbuf    *m;
549 	struct ether_header *eh;
550 	struct ether_aarp *ea;
551 	struct at_ifaddr *aa;
552 	struct llc     *llc;
553 	struct sockaddr sa;
554 	struct ifnet   *ifp = arp;
555 
556 	/*
557          * We need to check whether the output ethernet type should
558          * be phase 1 or 2. We have the interface that we'll be sending
559          * the aarp out. We need to find an AppleTalk network on that
560          * interface with the same address as we're looking for. If the
561          * net is phase 2, generate an 802.2 and SNAP header.
562          */
563 	for (aa = (struct at_ifaddr *) ifp->if_addrlist.tqh_first; aa;
564 	     aa = (struct at_ifaddr *) aa->aa_ifa.ifa_list.tqe_next) {
565 		if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
566 		    (aa->aa_flags & AFA_PROBING))
567 			break;
568 	}
569 	if (aa == NULL) {	/* serious error XXX */
570 		printf("aarpprobe why did this happen?!\n");
571 		return;
572 	}
573 	if (aa->aa_probcnt <= 0) {
574 		aa->aa_flags &= ~AFA_PROBING;
575 		wakeup(aa);
576 		return;
577 	} else {
578 		callout_reset(&aa->aa_probe_ch, hz / 5, aarpprobe, arp);
579 	}
580 
581 	if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
582 		return;
583 
584 	MCLAIM(m, &aarp_mowner);
585 	m->m_len = sizeof(*ea);
586 	m->m_pkthdr.len = sizeof(*ea);
587 	MH_ALIGN(m, sizeof(*ea));
588 
589 	ea = mtod(m, struct ether_aarp *);
590 	bzero(ea, sizeof(*ea));
591 
592 	ea->aarp_hrd = htons(AARPHRD_ETHER);
593 	ea->aarp_pro = htons(ETHERTYPE_ATALK);
594 	ea->aarp_hln = sizeof(ea->aarp_sha);
595 	ea->aarp_pln = sizeof(ea->aarp_spu);
596 	ea->aarp_op = htons(AARPOP_PROBE);
597 	bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
598 
599 	eh = (struct ether_header *) sa.sa_data;
600 
601 	if (aa->aa_flags & AFA_PHASE2) {
602 		bcopy(atmulticastaddr, eh->ether_dhost,
603 		    sizeof(eh->ether_dhost));
604 		eh->ether_type = 0;	/* if_output will treat as 802 */
605 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
606 		if (!m)
607 			return;
608 
609 		llc = mtod(m, struct llc *);
610 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
611 		llc->llc_control = LLC_UI;
612 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
613 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
614 
615 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_spnet,
616 		      sizeof(ea->aarp_spnet));
617 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_tpnet,
618 		      sizeof(ea->aarp_tpnet));
619 		ea->aarp_spnode = ea->aarp_tpnode =
620 		    AA_SAT(aa)->sat_addr.s_node;
621 	} else {
622 		bcopy(etherbroadcastaddr, eh->ether_dhost,
623 		    sizeof(eh->ether_dhost));
624 		eh->ether_type = htons(ETHERTYPE_AARP);
625 		ea->aarp_spa = ea->aarp_tpa = AA_SAT(aa)->sat_addr.s_node;
626 	}
627 
628 #ifdef NETATALKDEBUG
629 	printf("aarp: sending probe for %u.%u\n",
630 	       ntohs(AA_SAT(aa)->sat_addr.s_net),
631 	       AA_SAT(aa)->sat_addr.s_node);
632 #endif	/* NETATALKDEBUG */
633 
634 	sa.sa_len = sizeof(struct sockaddr);
635 	sa.sa_family = AF_UNSPEC;
636 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX */
637 	aa->aa_probcnt--;
638 }
639 
640 void
641 aarp_clean()
642 {
643 	struct aarptab *aat;
644 	int             i;
645 
646 	callout_stop(&aarptimer_callout);
647 	for (i = 0, aat = aarptab; i < AARPTAB_SIZE; i++, aat++)
648 		if (aat->aat_hold)
649 			m_freem(aat->aat_hold);
650 }
651