xref: /netbsd-src/sys/netatalk/aarp.c (revision e5548b402ae4c44fb816de42c7bba9581ce23ef5)
1 /*	$NetBSD: aarp.c,v 1.18 2005/12/11 12:24:54 christos 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 1.18 2005/12/11 12:24:54 christos 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 const u_char atmulticastaddr[6] = {
87 	0x09, 0x00, 0x07, 0xff, 0xff, 0xff
88 };
89 
90 const u_char at_org_code[3] = {
91 	0x08, 0x00, 0x07
92 };
93 const u_char aarp_org_code[3] = {
94 	0x00, 0x00, 0x00
95 };
96 
97 struct callout aarptimer_callout;
98 #ifdef MBUFTRACE
99 struct mowner aarp_mowner = { "atalk", "arp" };
100 #endif
101 
102 /*ARGSUSED*/
103 static void
104 aarptimer(ignored)
105 	void *ignored;
106 {
107 	struct aarptab *aat;
108 	int             i, s;
109 
110 	callout_reset(&aarptimer_callout, AARPT_AGE * hz, aarptimer, NULL);
111 	aat = aarptab;
112 	for (i = 0; i < AARPTAB_SIZE; i++, aat++) {
113 		int killtime = (aat->aat_flags & ATF_COM) ? AARPT_KILLC :
114 		    AARPT_KILLI;
115 		if (aat->aat_flags == 0 || (aat->aat_flags & ATF_PERM))
116 			continue;
117 		if (++aat->aat_timer < killtime)
118 			continue;
119 		s = splnet();
120 		aarptfree(aat);
121 		splx(s);
122 	}
123 }
124 
125 /*
126  * search through the network addresses to find one that includes the given
127  * network.. remember to take netranges into consideration.
128  */
129 struct ifaddr *
130 at_ifawithnet(sat, ifp)
131 	const struct sockaddr_at *sat;
132 	struct ifnet *ifp;
133 {
134 	struct ifaddr  *ifa;
135 	struct sockaddr_at *sat2;
136 	struct netrange *nr;
137 
138 	for (ifa = ifp->if_addrlist.tqh_first; ifa;
139 	    ifa = ifa->ifa_list.tqe_next) {
140 		if (ifa->ifa_addr->sa_family != AF_APPLETALK)
141 			continue;
142 
143 		sat2 = satosat(ifa->ifa_addr);
144 		if (sat2->sat_addr.s_net == sat->sat_addr.s_net)
145 			break;
146 
147 		nr = (struct netrange *) (sat2->sat_zero);
148 		if ((nr->nr_phase == 2)
149 		    && (ntohs(nr->nr_firstnet) <= ntohs(sat->sat_addr.s_net))
150 		    && (ntohs(nr->nr_lastnet) >= ntohs(sat->sat_addr.s_net)))
151 			break;
152 	}
153 	return ifa;
154 }
155 
156 static void
157 aarpwhohas(ifp, sat)
158 	struct ifnet *ifp;
159 	struct sockaddr_at *sat;
160 {
161 	struct mbuf    *m;
162 	struct ether_header *eh;
163 	struct ether_aarp *ea;
164 	struct at_ifaddr *aa;
165 	struct llc     *llc;
166 	struct sockaddr sa;
167 
168 	if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
169 		return;
170 
171 	MCLAIM(m, &aarp_mowner);
172 	m->m_len = sizeof(*ea);
173 	m->m_pkthdr.len = sizeof(*ea);
174 	MH_ALIGN(m, sizeof(*ea));
175 
176 	ea = mtod(m, struct ether_aarp *);
177 	bzero(ea, sizeof(*ea));
178 
179 	ea->aarp_hrd = htons(AARPHRD_ETHER);
180 	ea->aarp_pro = htons(ETHERTYPE_ATALK);
181 	ea->aarp_hln = sizeof(ea->aarp_sha);
182 	ea->aarp_pln = sizeof(ea->aarp_spu);
183 	ea->aarp_op = htons(AARPOP_REQUEST);
184 	bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
185 
186 	/*
187          * We need to check whether the output ethernet type should
188          * be phase 1 or 2. We have the interface that we'll be sending
189          * the aarp out. We need to find an AppleTalk network on that
190          * interface with the same address as we're looking for. If the
191          * net is phase 2, generate an 802.2 and SNAP header.
192          */
193 	if ((aa = (struct at_ifaddr *) at_ifawithnet(sat, ifp)) == NULL) {
194 		m_freem(m);
195 		return;
196 	}
197 	eh = (struct ether_header *) sa.sa_data;
198 
199 	if (aa->aa_flags & AFA_PHASE2) {
200 		bcopy(atmulticastaddr, eh->ether_dhost,
201 		    sizeof(eh->ether_dhost));
202 		eh->ether_type = 0;	/* if_output will treat as 802 */
203 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
204 		if (!m)
205 			return;
206 
207 		llc = mtod(m, struct llc *);
208 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
209 		llc->llc_control = LLC_UI;
210 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
211 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
212 
213 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_spnet,
214 		      sizeof(ea->aarp_spnet));
215 		bcopy(&sat->sat_addr.s_net, ea->aarp_tpnet,
216 		      sizeof(ea->aarp_tpnet));
217 		ea->aarp_spnode = AA_SAT(aa)->sat_addr.s_node;
218 		ea->aarp_tpnode = sat->sat_addr.s_node;
219 	} else {
220 		bcopy(etherbroadcastaddr, eh->ether_dhost,
221 		    sizeof(eh->ether_dhost));
222 		eh->ether_type = htons(ETHERTYPE_AARP);
223 
224 		ea->aarp_spa = AA_SAT(aa)->sat_addr.s_node;
225 		ea->aarp_tpa = sat->sat_addr.s_node;
226 	}
227 
228 #ifdef NETATALKDEBUG
229 	printf("aarp: sending request via %u.%u seaking %u.%u\n",
230 	    ntohs(AA_SAT(aa)->sat_addr.s_net), AA_SAT(aa)->sat_addr.s_node,
231 	    ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node);
232 #endif	/* NETATALKDEBUG */
233 
234 	sa.sa_len = sizeof(struct sockaddr);
235 	sa.sa_family = AF_UNSPEC;
236 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX NULL should be routing */
237 						/* information */
238 }
239 
240 int
241 aarpresolve(ifp, m, destsat, desten)
242 	struct ifnet   *ifp;
243 	struct mbuf    *m;
244 	struct sockaddr_at *destsat;
245 	u_char         *desten;
246 {
247 	struct at_ifaddr *aa;
248 	struct aarptab *aat;
249 	int             s;
250 
251 	if (at_broadcast(destsat)) {
252 		aa = (struct at_ifaddr *) at_ifawithnet(destsat, ifp);
253 		if (aa == NULL) {
254 			m_freem(m);
255 			return (0);
256 		}
257 		if (aa->aa_flags & AFA_PHASE2)
258 			bcopy(atmulticastaddr, desten,
259 			    sizeof(atmulticastaddr));
260 		else
261 			bcopy(etherbroadcastaddr, desten,
262 			    sizeof(etherbroadcastaddr));
263 		return 1;
264 	}
265 	s = splnet();
266 	AARPTAB_LOOK(aat, destsat->sat_addr);
267 	if (aat == 0) {		/* No entry */
268 		aat = aarptnew(&destsat->sat_addr);
269 		if (aat == 0)
270 			panic("aarpresolve: no free entry");
271 
272 		aat->aat_hold = m;
273 		aarpwhohas(ifp, destsat);
274 		splx(s);
275 		return 0;
276 	}
277 
278 	/* found an entry */
279 	aat->aat_timer = 0;
280 	if (aat->aat_flags & ATF_COM) {	/* entry is COMplete */
281 		bcopy(aat->aat_enaddr, desten, sizeof(aat->aat_enaddr));
282 		splx(s);
283 		return 1;
284 	}
285 
286 	/* entry has not completed */
287 	if (aat->aat_hold)
288 		m_freem(aat->aat_hold);
289 	aat->aat_hold = m;
290 	aarpwhohas(ifp, destsat);
291 	splx(s);
292 
293 	return 0;
294 }
295 
296 void
297 aarpinput(ifp, m)
298 	struct ifnet   *ifp;
299 	struct mbuf    *m;
300 {
301 	struct arphdr  *ar;
302 
303 	if (ifp->if_flags & IFF_NOARP)
304 		goto out;
305 
306 	if (m->m_len < sizeof(struct arphdr))
307 		goto out;
308 
309 	ar = mtod(m, struct arphdr *);
310 	if (ntohs(ar->ar_hrd) != AARPHRD_ETHER)
311 		goto out;
312 
313 	if (m->m_len < sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln)
314 		goto out;
315 
316 	switch (ntohs(ar->ar_pro)) {
317 	case ETHERTYPE_ATALK:
318 		at_aarpinput(ifp, m);
319 		return;
320 
321 	default:
322 		break;
323 	}
324 
325 out:
326 	m_freem(m);
327 }
328 
329 static void
330 at_aarpinput(ifp, m)
331 	struct ifnet *ifp;
332 	struct mbuf *m;
333 {
334 	struct ether_aarp *ea;
335 	struct at_ifaddr *aa;
336 	struct aarptab *aat;
337 	struct ether_header *eh;
338 	struct llc     *llc;
339 	struct sockaddr_at sat;
340 	struct sockaddr sa;
341 	struct at_addr  spa, tpa, ma;
342 	int             op;
343 	u_int16_t       net;
344 
345 	ea = mtod(m, struct ether_aarp *);
346 
347 	/* Check to see if from my hardware address */
348 	if (!bcmp(ea->aarp_sha, LLADDR(ifp->if_sadl), sizeof(ea->aarp_sha))) {
349 		m_freem(m);
350 		return;
351 	}
352 	op = ntohs(ea->aarp_op);
353 	bcopy(ea->aarp_tpnet, &net, sizeof(net));
354 
355 	if (net != 0) {		/* should be ATADDR_ANYNET? */
356 		sat.sat_len = sizeof(struct sockaddr_at);
357 		sat.sat_family = AF_APPLETALK;
358 		sat.sat_addr.s_net = net;
359 		aa = (struct at_ifaddr *) at_ifawithnet(&sat, ifp);
360 		if (aa == NULL) {
361 			m_freem(m);
362 			return;
363 		}
364 		bcopy(ea->aarp_spnet, &spa.s_net, sizeof(spa.s_net));
365 		bcopy(ea->aarp_tpnet, &tpa.s_net, sizeof(tpa.s_net));
366 	} else {
367 		/*
368 		 * Since we don't know the net, we just look for the first
369 		 * phase 1 address on the interface.
370 		 */
371 		for (aa = (struct at_ifaddr *) ifp->if_addrlist.tqh_first; aa;
372 		    aa = (struct at_ifaddr *) aa->aa_ifa.ifa_list.tqe_next) {
373 			if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
374 			    (aa->aa_flags & AFA_PHASE2) == 0)
375 				break;
376 		}
377 		if (aa == NULL) {
378 			m_freem(m);
379 			return;
380 		}
381 		tpa.s_net = spa.s_net = AA_SAT(aa)->sat_addr.s_net;
382 	}
383 
384 	spa.s_node = ea->aarp_spnode;
385 	tpa.s_node = ea->aarp_tpnode;
386 	ma.s_net = AA_SAT(aa)->sat_addr.s_net;
387 	ma.s_node = AA_SAT(aa)->sat_addr.s_node;
388 
389 	/*
390          * This looks like it's from us.
391          */
392 	if (spa.s_net == ma.s_net && spa.s_node == ma.s_node) {
393 		if (aa->aa_flags & AFA_PROBING) {
394 			/*
395 		         * We're probing, someone either responded to our
396 			 * probe, or probed for the same address we'd like
397 			 * to use. Change the address we're probing for.
398 		         */
399 			callout_stop(&aa->aa_probe_ch);
400 			wakeup(aa);
401 			m_freem(m);
402 			return;
403 		} else if (op != AARPOP_PROBE) {
404 			/*
405 		         * This is not a probe, and we're not probing.
406 			 * This means that someone's saying they have the same
407 			 * source address as the one we're using. Get upset...
408 		         */
409 			log(LOG_ERR, "aarp: duplicate AT address!! %s\n",
410 			    ether_sprintf(ea->aarp_sha));
411 			m_freem(m);
412 			return;
413 		}
414 	}
415 	AARPTAB_LOOK(aat, spa);
416 	if (aat) {
417 		if (op == AARPOP_PROBE) {
418 			/*
419 		         * Someone's probing for spa, deallocate the one we've
420 			 * got, so that if the prober keeps the address, we'll
421 			 * be able to arp for him.
422 		         */
423 			aarptfree(aat);
424 			m_freem(m);
425 			return;
426 		}
427 		bcopy(ea->aarp_sha, aat->aat_enaddr, sizeof(ea->aarp_sha));
428 		aat->aat_flags |= ATF_COM;
429 		if (aat->aat_hold) {
430 			sat.sat_len = sizeof(struct sockaddr_at);
431 			sat.sat_family = AF_APPLETALK;
432 			sat.sat_addr = spa;
433 			(*ifp->if_output)(ifp, aat->aat_hold,
434 			    (struct sockaddr *) & sat, NULL);	/* XXX */
435 			aat->aat_hold = 0;
436 		}
437 	}
438 	if (aat == 0 && tpa.s_net == ma.s_net && tpa.s_node == ma.s_node
439 	    && op != AARPOP_PROBE) {
440 		if ((aat = aarptnew(&spa)) != NULL) {
441 			bcopy(ea->aarp_sha, aat->aat_enaddr,
442 			    sizeof(ea->aarp_sha));
443 			aat->aat_flags |= ATF_COM;
444 		}
445 	}
446 	/*
447          * Don't respond to responses, and never respond if we're
448          * still probing.
449          */
450 	if (tpa.s_net != ma.s_net || tpa.s_node != ma.s_node ||
451 	    op == AARPOP_RESPONSE || (aa->aa_flags & AFA_PROBING)) {
452 		m_freem(m);
453 		return;
454 	}
455 	bcopy(ea->aarp_sha, ea->aarp_tha, sizeof(ea->aarp_sha));
456 	bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
457 
458 	/* XXX */
459 	eh = (struct ether_header *) sa.sa_data;
460 	bcopy(ea->aarp_tha, eh->ether_dhost, sizeof(eh->ether_dhost));
461 
462 	if (aa->aa_flags & AFA_PHASE2) {
463 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
464 		if (m == NULL)
465 			return;
466 
467 		llc = mtod(m, struct llc *);
468 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
469 		llc->llc_control = LLC_UI;
470 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
471 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
472 
473 		bcopy(ea->aarp_spnet, ea->aarp_tpnet, sizeof(ea->aarp_tpnet));
474 		bcopy(&ma.s_net, ea->aarp_spnet, sizeof(ea->aarp_spnet));
475 		eh->ether_type = 0;	/* if_output will treat as 802 */
476 	} else {
477 		eh->ether_type = htons(ETHERTYPE_AARP);
478 	}
479 
480 	ea->aarp_tpnode = ea->aarp_spnode;
481 	ea->aarp_spnode = ma.s_node;
482 	ea->aarp_op = htons(AARPOP_RESPONSE);
483 
484 	sa.sa_len = sizeof(struct sockaddr);
485 	sa.sa_family = AF_UNSPEC;
486 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX */
487 	return;
488 }
489 
490 static void
491 aarptfree(aat)
492 	struct aarptab *aat;
493 {
494 
495 	if (aat->aat_hold)
496 		m_freem(aat->aat_hold);
497 	aat->aat_hold = 0;
498 	aat->aat_timer = aat->aat_flags = 0;
499 	aat->aat_ataddr.s_net = 0;
500 	aat->aat_ataddr.s_node = 0;
501 }
502 
503 static struct aarptab *
504 aarptnew(addr)
505 	struct at_addr *addr;
506 {
507 	int             n;
508 	int             oldest = -1;
509 	struct aarptab *aat, *aato = NULL;
510 	static int      first = 1;
511 
512 	if (first) {
513 		first = 0;
514 		callout_init(&aarptimer_callout);
515 		callout_reset(&aarptimer_callout, hz, aarptimer, NULL);
516 		MOWNER_ATTACH(&aarp_mowner);
517 	}
518 	aat = &aarptab[AARPTAB_HASH(*addr) * AARPTAB_BSIZ];
519 	for (n = 0; n < AARPTAB_BSIZ; n++, aat++) {
520 		if (aat->aat_flags == 0)
521 			goto out;
522 		if (aat->aat_flags & ATF_PERM)
523 			continue;
524 		if ((int) aat->aat_timer > oldest) {
525 			oldest = aat->aat_timer;
526 			aato = aat;
527 		}
528 	}
529 	if (aato == NULL)
530 		return (NULL);
531 	aat = aato;
532 	aarptfree(aat);
533 out:
534 	aat->aat_ataddr = *addr;
535 	aat->aat_flags = ATF_INUSE;
536 	return (aat);
537 }
538 
539 
540 void
541 aarpprobe(arp)
542 	void *arp;
543 {
544 	struct mbuf    *m;
545 	struct ether_header *eh;
546 	struct ether_aarp *ea;
547 	struct at_ifaddr *aa;
548 	struct llc     *llc;
549 	struct sockaddr sa;
550 	struct ifnet   *ifp = arp;
551 
552 	/*
553          * We need to check whether the output ethernet type should
554          * be phase 1 or 2. We have the interface that we'll be sending
555          * the aarp out. We need to find an AppleTalk network on that
556          * interface with the same address as we're looking for. If the
557          * net is phase 2, generate an 802.2 and SNAP header.
558          */
559 	for (aa = (struct at_ifaddr *) ifp->if_addrlist.tqh_first; aa;
560 	     aa = (struct at_ifaddr *) aa->aa_ifa.ifa_list.tqe_next) {
561 		if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
562 		    (aa->aa_flags & AFA_PROBING))
563 			break;
564 	}
565 	if (aa == NULL) {	/* serious error XXX */
566 		printf("aarpprobe why did this happen?!\n");
567 		return;
568 	}
569 	if (aa->aa_probcnt <= 0) {
570 		aa->aa_flags &= ~AFA_PROBING;
571 		wakeup(aa);
572 		return;
573 	} else {
574 		callout_reset(&aa->aa_probe_ch, hz / 5, aarpprobe, arp);
575 	}
576 
577 	if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
578 		return;
579 
580 	MCLAIM(m, &aarp_mowner);
581 	m->m_len = sizeof(*ea);
582 	m->m_pkthdr.len = sizeof(*ea);
583 	MH_ALIGN(m, sizeof(*ea));
584 
585 	ea = mtod(m, struct ether_aarp *);
586 	bzero(ea, sizeof(*ea));
587 
588 	ea->aarp_hrd = htons(AARPHRD_ETHER);
589 	ea->aarp_pro = htons(ETHERTYPE_ATALK);
590 	ea->aarp_hln = sizeof(ea->aarp_sha);
591 	ea->aarp_pln = sizeof(ea->aarp_spu);
592 	ea->aarp_op = htons(AARPOP_PROBE);
593 	bcopy(LLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
594 
595 	eh = (struct ether_header *) sa.sa_data;
596 
597 	if (aa->aa_flags & AFA_PHASE2) {
598 		bcopy(atmulticastaddr, eh->ether_dhost,
599 		    sizeof(eh->ether_dhost));
600 		eh->ether_type = 0;	/* if_output will treat as 802 */
601 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
602 		if (!m)
603 			return;
604 
605 		llc = mtod(m, struct llc *);
606 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
607 		llc->llc_control = LLC_UI;
608 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
609 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
610 
611 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_spnet,
612 		      sizeof(ea->aarp_spnet));
613 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_tpnet,
614 		      sizeof(ea->aarp_tpnet));
615 		ea->aarp_spnode = ea->aarp_tpnode =
616 		    AA_SAT(aa)->sat_addr.s_node;
617 	} else {
618 		bcopy(etherbroadcastaddr, eh->ether_dhost,
619 		    sizeof(eh->ether_dhost));
620 		eh->ether_type = htons(ETHERTYPE_AARP);
621 		ea->aarp_spa = ea->aarp_tpa = AA_SAT(aa)->sat_addr.s_node;
622 	}
623 
624 #ifdef NETATALKDEBUG
625 	printf("aarp: sending probe for %u.%u\n",
626 	       ntohs(AA_SAT(aa)->sat_addr.s_net),
627 	       AA_SAT(aa)->sat_addr.s_node);
628 #endif	/* NETATALKDEBUG */
629 
630 	sa.sa_len = sizeof(struct sockaddr);
631 	sa.sa_family = AF_UNSPEC;
632 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX */
633 	aa->aa_probcnt--;
634 }
635 
636 void
637 aarp_clean()
638 {
639 	struct aarptab *aat;
640 	int             i;
641 
642 	callout_stop(&aarptimer_callout);
643 	for (i = 0, aat = aarptab; i < AARPTAB_SIZE; i++, aat++)
644 		if (aat->aat_hold)
645 			m_freem(aat->aat_hold);
646 }
647