xref: /netbsd-src/sys/netatalk/aarp.c (revision 404fbe5fb94ca1e054339640cabb2801ce52dd30)
1 /*	$NetBSD: aarp.c,v 1.27 2008/04/24 11:38:37 ad 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 1.27 2008/04/24 11:38:37 ad 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 <sys/socketvar.h>
44 #include <net/if.h>
45 #include <net/route.h>
46 #include <net/if_ether.h>
47 #include <net/if_dl.h>
48 #include <netinet/in.h>
49 #undef s_net
50 
51 #include <netatalk/at.h>
52 #include <netatalk/at_var.h>
53 #include <netatalk/aarp.h>
54 #include <netatalk/ddp_var.h>
55 #include <netatalk/phase2.h>
56 #include <netatalk/at_extern.h>
57 
58 static struct aarptab *aarptnew(const struct at_addr *);
59 static void aarptfree(struct aarptab *);
60 static void at_aarpinput(struct ifnet *, struct mbuf *);
61 static void aarptimer(void *);
62 static void aarpwhohas(struct ifnet *, const struct sockaddr_at *);
63 
64 #define AARPTAB_BSIZ	9
65 #define AARPTAB_NB	19
66 #define AARPTAB_SIZE	(AARPTAB_BSIZ * AARPTAB_NB)
67 struct aarptab  aarptab[AARPTAB_SIZE];
68 
69 #define AARPTAB_HASH(a) \
70     ((((a).s_net << 8 ) + (a).s_node ) % AARPTAB_NB )
71 
72 #define AARPTAB_LOOK(aat,addr) { \
73     int		n; \
74     aat = &aarptab[ AARPTAB_HASH(addr) * AARPTAB_BSIZ ]; \
75     for ( n = 0; n < AARPTAB_BSIZ; n++, aat++ ) \
76 	if ( aat->aat_ataddr.s_net == (addr).s_net && \
77 	     aat->aat_ataddr.s_node == (addr).s_node ) \
78 	    break; \
79 	if ( n >= AARPTAB_BSIZ ) \
80 	    aat = 0; \
81 }
82 
83 #define AARPT_AGE	(60 * 1)
84 #define AARPT_KILLC	20
85 #define AARPT_KILLI	3
86 
87 const u_char atmulticastaddr[6] = {
88 	0x09, 0x00, 0x07, 0xff, 0xff, 0xff
89 };
90 
91 const u_char at_org_code[3] = {
92 	0x08, 0x00, 0x07
93 };
94 const u_char aarp_org_code[3] = {
95 	0x00, 0x00, 0x00
96 };
97 
98 struct callout aarptimer_callout;
99 #ifdef MBUFTRACE
100 struct mowner aarp_mowner = MOWNER_INIT("atalk", "arp");
101 #endif
102 
103 /*ARGSUSED*/
104 static void
105 aarptimer(void *ignored)
106 {
107 	struct aarptab *aat;
108 	int             i, s;
109 
110 	mutex_enter(softnet_lock);
111 	callout_reset(&aarptimer_callout, AARPT_AGE * hz, aarptimer, NULL);
112 	aat = aarptab;
113 	for (i = 0; i < AARPTAB_SIZE; i++, aat++) {
114 		int killtime = (aat->aat_flags & ATF_COM) ? AARPT_KILLC :
115 		    AARPT_KILLI;
116 		if (aat->aat_flags == 0 || (aat->aat_flags & ATF_PERM))
117 			continue;
118 		if (++aat->aat_timer < killtime)
119 			continue;
120 		s = splnet();
121 		aarptfree(aat);
122 		splx(s);
123 	}
124 	mutex_exit(softnet_lock);
125 }
126 
127 /*
128  * search through the network addresses to find one that includes the given
129  * network.. remember to take netranges into consideration.
130  */
131 struct ifaddr *
132 at_ifawithnet(sat, ifp)
133 	const struct sockaddr_at *sat;
134 	struct ifnet *ifp;
135 {
136 	struct ifaddr  *ifa;
137 	struct sockaddr_at *sat2;
138 	struct netrange *nr;
139 
140 	IFADDR_FOREACH(ifa, ifp) {
141 		if (ifa->ifa_addr->sa_family != AF_APPLETALK)
142 			continue;
143 
144 		sat2 = satosat(ifa->ifa_addr);
145 		if (sat2->sat_addr.s_net == sat->sat_addr.s_net)
146 			break;
147 
148 		nr = (struct netrange *) (sat2->sat_zero);
149 		if ((nr->nr_phase == 2)
150 		    && (ntohs(nr->nr_firstnet) <= ntohs(sat->sat_addr.s_net))
151 		    && (ntohs(nr->nr_lastnet) >= ntohs(sat->sat_addr.s_net)))
152 			break;
153 	}
154 	return ifa;
155 }
156 
157 static void
158 aarpwhohas(ifp, sat)
159 	struct ifnet *ifp;
160 	const struct sockaddr_at *sat;
161 {
162 	struct mbuf    *m;
163 	struct ether_header *eh;
164 	struct ether_aarp *ea;
165 	struct at_ifaddr *aa;
166 	struct llc     *llc;
167 	struct sockaddr sa;
168 
169 	if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL)
170 		return;
171 
172 	MCLAIM(m, &aarp_mowner);
173 	m->m_len = sizeof(*ea);
174 	m->m_pkthdr.len = sizeof(*ea);
175 	MH_ALIGN(m, sizeof(*ea));
176 
177 	ea = mtod(m, struct ether_aarp *);
178 	bzero(ea, sizeof(*ea));
179 
180 	ea->aarp_hrd = htons(AARPHRD_ETHER);
181 	ea->aarp_pro = htons(ETHERTYPE_ATALK);
182 	ea->aarp_hln = sizeof(ea->aarp_sha);
183 	ea->aarp_pln = sizeof(ea->aarp_spu);
184 	ea->aarp_op = htons(AARPOP_REQUEST);
185 	bcopy(CLLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
186 
187 	/*
188          * We need to check whether the output ethernet type should
189          * be phase 1 or 2. We have the interface that we'll be sending
190          * the aarp out. We need to find an AppleTalk network on that
191          * interface with the same address as we're looking for. If the
192          * net is phase 2, generate an 802.2 and SNAP header.
193          */
194 	if ((aa = (struct at_ifaddr *) at_ifawithnet(sat, ifp)) == NULL) {
195 		m_freem(m);
196 		return;
197 	}
198 	eh = (struct ether_header *) sa.sa_data;
199 
200 	if (aa->aa_flags & AFA_PHASE2) {
201 		bcopy(atmulticastaddr, eh->ether_dhost,
202 		    sizeof(eh->ether_dhost));
203 		eh->ether_type = 0;	/* if_output will treat as 802 */
204 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
205 		if (!m)
206 			return;
207 
208 		llc = mtod(m, struct llc *);
209 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
210 		llc->llc_control = LLC_UI;
211 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
212 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
213 
214 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_spnet,
215 		      sizeof(ea->aarp_spnet));
216 		bcopy(&sat->sat_addr.s_net, ea->aarp_tpnet,
217 		      sizeof(ea->aarp_tpnet));
218 		ea->aarp_spnode = AA_SAT(aa)->sat_addr.s_node;
219 		ea->aarp_tpnode = sat->sat_addr.s_node;
220 	} else {
221 		bcopy(etherbroadcastaddr, eh->ether_dhost,
222 		    sizeof(eh->ether_dhost));
223 		eh->ether_type = htons(ETHERTYPE_AARP);
224 
225 		ea->aarp_spa = AA_SAT(aa)->sat_addr.s_node;
226 		ea->aarp_tpa = sat->sat_addr.s_node;
227 	}
228 
229 #ifdef NETATALKDEBUG
230 	printf("aarp: sending request via %u.%u seaking %u.%u\n",
231 	    ntohs(AA_SAT(aa)->sat_addr.s_net), AA_SAT(aa)->sat_addr.s_node,
232 	    ntohs(sat->sat_addr.s_net), sat->sat_addr.s_node);
233 #endif	/* NETATALKDEBUG */
234 
235 	sa.sa_len = sizeof(struct sockaddr);
236 	sa.sa_family = AF_UNSPEC;
237 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX NULL should be routing */
238 						/* information */
239 }
240 
241 int
242 aarpresolve(struct ifnet *ifp, struct mbuf *m,
243     const struct sockaddr_at *destsat, u_char *desten)
244 {
245 	struct at_ifaddr *aa;
246 	struct aarptab *aat;
247 	int             s;
248 
249 	if (at_broadcast(destsat)) {
250 		aa = (struct at_ifaddr *) at_ifawithnet(destsat, ifp);
251 		if (aa == NULL) {
252 			m_freem(m);
253 			return (0);
254 		}
255 		if (aa->aa_flags & AFA_PHASE2)
256 			bcopy(atmulticastaddr, desten,
257 			    sizeof(atmulticastaddr));
258 		else
259 			bcopy(etherbroadcastaddr, desten,
260 			    sizeof(etherbroadcastaddr));
261 		return 1;
262 	}
263 	s = splnet();
264 	AARPTAB_LOOK(aat, destsat->sat_addr);
265 	if (aat == 0) {		/* No entry */
266 		aat = aarptnew(&destsat->sat_addr);
267 		if (aat == 0)
268 			panic("aarpresolve: no free entry");
269 
270 		aat->aat_hold = m;
271 		aarpwhohas(ifp, destsat);
272 		splx(s);
273 		return 0;
274 	}
275 
276 	/* found an entry */
277 	aat->aat_timer = 0;
278 	if (aat->aat_flags & ATF_COM) {	/* entry is COMplete */
279 		bcopy(aat->aat_enaddr, desten, sizeof(aat->aat_enaddr));
280 		splx(s);
281 		return 1;
282 	}
283 
284 	/* entry has not completed */
285 	if (aat->aat_hold)
286 		m_freem(aat->aat_hold);
287 	aat->aat_hold = m;
288 	aarpwhohas(ifp, destsat);
289 	splx(s);
290 
291 	return 0;
292 }
293 
294 void
295 aarpinput(ifp, m)
296 	struct ifnet   *ifp;
297 	struct mbuf    *m;
298 {
299 	struct arphdr  *ar;
300 
301 	if (ifp->if_flags & IFF_NOARP)
302 		goto out;
303 
304 	if (m->m_len < sizeof(struct arphdr))
305 		goto out;
306 
307 	ar = mtod(m, struct arphdr *);
308 	if (ntohs(ar->ar_hrd) != AARPHRD_ETHER)
309 		goto out;
310 
311 	if (m->m_len < sizeof(struct arphdr) + 2 * ar->ar_hln + 2 * ar->ar_pln)
312 		goto out;
313 
314 	switch (ntohs(ar->ar_pro)) {
315 	case ETHERTYPE_ATALK:
316 		at_aarpinput(ifp, m);
317 		return;
318 
319 	default:
320 		break;
321 	}
322 
323 out:
324 	m_freem(m);
325 }
326 
327 static void
328 at_aarpinput(ifp, m)
329 	struct ifnet *ifp;
330 	struct mbuf *m;
331 {
332 	struct ether_aarp *ea;
333 	struct at_ifaddr *aa;
334 	struct ifaddr *ia;
335 	struct aarptab *aat;
336 	struct ether_header *eh;
337 	struct llc     *llc;
338 	struct sockaddr_at sat;
339 	struct sockaddr sa;
340 	struct at_addr  spa, tpa, ma;
341 	int             op;
342 	u_int16_t       net;
343 
344 	ea = mtod(m, struct ether_aarp *);
345 
346 	/* Check to see if from my hardware address */
347 	if (!bcmp(ea->aarp_sha, CLLADDR(ifp->if_sadl), sizeof(ea->aarp_sha))) {
348 		m_freem(m);
349 		return;
350 	}
351 	op = ntohs(ea->aarp_op);
352 	bcopy(ea->aarp_tpnet, &net, sizeof(net));
353 
354 	if (net != 0) {		/* should be ATADDR_ANYNET? */
355 		sat.sat_len = sizeof(struct sockaddr_at);
356 		sat.sat_family = AF_APPLETALK;
357 		sat.sat_addr.s_net = net;
358 		aa = (struct at_ifaddr *) at_ifawithnet(&sat, ifp);
359 		if (aa == NULL) {
360 			m_freem(m);
361 			return;
362 		}
363 		bcopy(ea->aarp_spnet, &spa.s_net, sizeof(spa.s_net));
364 		bcopy(ea->aarp_tpnet, &tpa.s_net, sizeof(tpa.s_net));
365 	} else {
366 		/*
367 		 * Since we don't know the net, we just look for the first
368 		 * phase 1 address on the interface.
369 		 */
370 		IFADDR_FOREACH(ia, ifp) {
371 			aa = (struct at_ifaddr *)ia;
372 			if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
373 			    (aa->aa_flags & AFA_PHASE2) == 0)
374 				break;
375 		}
376 		if (ia == NULL) {
377 			m_freem(m);
378 			return;
379 		}
380 		tpa.s_net = spa.s_net = AA_SAT(aa)->sat_addr.s_net;
381 	}
382 
383 	spa.s_node = ea->aarp_spnode;
384 	tpa.s_node = ea->aarp_tpnode;
385 	ma.s_net = AA_SAT(aa)->sat_addr.s_net;
386 	ma.s_node = AA_SAT(aa)->sat_addr.s_node;
387 
388 	/*
389          * This looks like it's from us.
390          */
391 	if (spa.s_net == ma.s_net && spa.s_node == ma.s_node) {
392 		if (aa->aa_flags & AFA_PROBING) {
393 			/*
394 		         * We're probing, someone either responded to our
395 			 * probe, or probed for the same address we'd like
396 			 * to use. Change the address we're probing for.
397 		         */
398 			callout_stop(&aa->aa_probe_ch);
399 			wakeup(aa);
400 			m_freem(m);
401 			return;
402 		} else if (op != AARPOP_PROBE) {
403 			/*
404 		         * This is not a probe, and we're not probing.
405 			 * This means that someone's saying they have the same
406 			 * source address as the one we're using. Get upset...
407 		         */
408 			log(LOG_ERR, "aarp: duplicate AT address!! %s\n",
409 			    ether_sprintf(ea->aarp_sha));
410 			m_freem(m);
411 			return;
412 		}
413 	}
414 	AARPTAB_LOOK(aat, spa);
415 	if (aat) {
416 		if (op == AARPOP_PROBE) {
417 			/*
418 		         * Someone's probing for spa, deallocate the one we've
419 			 * got, so that if the prober keeps the address, we'll
420 			 * be able to arp for him.
421 		         */
422 			aarptfree(aat);
423 			m_freem(m);
424 			return;
425 		}
426 		bcopy(ea->aarp_sha, aat->aat_enaddr, sizeof(ea->aarp_sha));
427 		aat->aat_flags |= ATF_COM;
428 		if (aat->aat_hold) {
429 			sat.sat_len = sizeof(struct sockaddr_at);
430 			sat.sat_family = AF_APPLETALK;
431 			sat.sat_addr = spa;
432 			(*ifp->if_output)(ifp, aat->aat_hold,
433 			    (struct sockaddr *) & sat, NULL);	/* XXX */
434 			aat->aat_hold = 0;
435 		}
436 	}
437 	if (aat == 0 && tpa.s_net == ma.s_net && tpa.s_node == ma.s_node
438 	    && op != AARPOP_PROBE) {
439 		if ((aat = aarptnew(&spa)) != NULL) {
440 			bcopy(ea->aarp_sha, aat->aat_enaddr,
441 			    sizeof(ea->aarp_sha));
442 			aat->aat_flags |= ATF_COM;
443 		}
444 	}
445 	/*
446          * Don't respond to responses, and never respond if we're
447          * still probing.
448          */
449 	if (tpa.s_net != ma.s_net || tpa.s_node != ma.s_node ||
450 	    op == AARPOP_RESPONSE || (aa->aa_flags & AFA_PROBING)) {
451 		m_freem(m);
452 		return;
453 	}
454 	bcopy(ea->aarp_sha, ea->aarp_tha, sizeof(ea->aarp_sha));
455 	bcopy(CLLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
456 
457 	/* XXX */
458 	eh = (struct ether_header *) sa.sa_data;
459 	bcopy(ea->aarp_tha, eh->ether_dhost, sizeof(eh->ether_dhost));
460 
461 	if (aa->aa_flags & AFA_PHASE2) {
462 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
463 		if (m == NULL)
464 			return;
465 
466 		llc = mtod(m, struct llc *);
467 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
468 		llc->llc_control = LLC_UI;
469 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
470 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
471 
472 		bcopy(ea->aarp_spnet, ea->aarp_tpnet, sizeof(ea->aarp_tpnet));
473 		bcopy(&ma.s_net, ea->aarp_spnet, sizeof(ea->aarp_spnet));
474 		eh->ether_type = 0;	/* if_output will treat as 802 */
475 	} else {
476 		eh->ether_type = htons(ETHERTYPE_AARP);
477 	}
478 
479 	ea->aarp_tpnode = ea->aarp_spnode;
480 	ea->aarp_spnode = ma.s_node;
481 	ea->aarp_op = htons(AARPOP_RESPONSE);
482 
483 	sa.sa_len = sizeof(struct sockaddr);
484 	sa.sa_family = AF_UNSPEC;
485 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX */
486 	return;
487 }
488 
489 static void
490 aarptfree(aat)
491 	struct aarptab *aat;
492 {
493 
494 	if (aat->aat_hold)
495 		m_freem(aat->aat_hold);
496 	aat->aat_hold = 0;
497 	aat->aat_timer = aat->aat_flags = 0;
498 	aat->aat_ataddr.s_net = 0;
499 	aat->aat_ataddr.s_node = 0;
500 }
501 
502 static struct aarptab *
503 aarptnew(const struct at_addr *addr)
504 {
505 	int             n;
506 	int             oldest = -1;
507 	struct aarptab *aat, *aato = NULL;
508 	static int      first = 1;
509 
510 	if (first) {
511 		first = 0;
512 		callout_init(&aarptimer_callout, 0);
513 		callout_reset(&aarptimer_callout, hz, aarptimer, NULL);
514 		MOWNER_ATTACH(&aarp_mowner);
515 	}
516 	aat = &aarptab[AARPTAB_HASH(*addr) * AARPTAB_BSIZ];
517 	for (n = 0; n < AARPTAB_BSIZ; n++, aat++) {
518 		if (aat->aat_flags == 0)
519 			goto out;
520 		if (aat->aat_flags & ATF_PERM)
521 			continue;
522 		if ((int) aat->aat_timer > oldest) {
523 			oldest = aat->aat_timer;
524 			aato = aat;
525 		}
526 	}
527 	if (aato == NULL)
528 		return (NULL);
529 	aat = aato;
530 	aarptfree(aat);
531 out:
532 	aat->aat_ataddr = *addr;
533 	aat->aat_flags = ATF_INUSE;
534 	return (aat);
535 }
536 
537 
538 void
539 aarpprobe(arp)
540 	void *arp;
541 {
542 	struct mbuf    *m;
543 	struct ether_header *eh;
544 	struct ether_aarp *ea;
545 	struct ifaddr *ia;
546 	struct at_ifaddr *aa;
547 	struct llc     *llc;
548 	struct sockaddr sa;
549 	struct ifnet   *ifp = arp;
550 
551 	mutex_enter(softnet_lock);
552 
553 	/*
554          * We need to check whether the output ethernet type should
555          * be phase 1 or 2. We have the interface that we'll be sending
556          * the aarp out. We need to find an AppleTalk network on that
557          * interface with the same address as we're looking for. If the
558          * net is phase 2, generate an 802.2 and SNAP header.
559          */
560 	IFADDR_FOREACH(ia, ifp) {
561 		aa = (struct at_ifaddr *)ia;
562 		if (AA_SAT(aa)->sat_family == AF_APPLETALK &&
563 		    (aa->aa_flags & AFA_PROBING))
564 			break;
565 	}
566 	if (ia == NULL) {	/* serious error XXX */
567 		printf("aarpprobe why did this happen?!\n");
568 		mutex_exit(softnet_lock);
569 		return;
570 	}
571 	if (aa->aa_probcnt <= 0) {
572 		aa->aa_flags &= ~AFA_PROBING;
573 		wakeup(aa);
574 		mutex_exit(softnet_lock);
575 		return;
576 	} else {
577 		callout_reset(&aa->aa_probe_ch, hz / 5, aarpprobe, arp);
578 	}
579 
580 	if ((m = m_gethdr(M_DONTWAIT, MT_DATA)) == NULL) {
581 		mutex_exit(softnet_lock);
582 		return;
583 	}
584 
585 	MCLAIM(m, &aarp_mowner);
586 	m->m_len = sizeof(*ea);
587 	m->m_pkthdr.len = sizeof(*ea);
588 	MH_ALIGN(m, sizeof(*ea));
589 
590 	ea = mtod(m, struct ether_aarp *);
591 	bzero(ea, sizeof(*ea));
592 
593 	ea->aarp_hrd = htons(AARPHRD_ETHER);
594 	ea->aarp_pro = htons(ETHERTYPE_ATALK);
595 	ea->aarp_hln = sizeof(ea->aarp_sha);
596 	ea->aarp_pln = sizeof(ea->aarp_spu);
597 	ea->aarp_op = htons(AARPOP_PROBE);
598 	bcopy(CLLADDR(ifp->if_sadl), ea->aarp_sha, sizeof(ea->aarp_sha));
599 
600 	eh = (struct ether_header *) sa.sa_data;
601 
602 	if (aa->aa_flags & AFA_PHASE2) {
603 		bcopy(atmulticastaddr, eh->ether_dhost,
604 		    sizeof(eh->ether_dhost));
605 		eh->ether_type = 0;	/* if_output will treat as 802 */
606 		M_PREPEND(m, sizeof(struct llc), M_DONTWAIT);
607 		if (!m) {
608 			mutex_exit(softnet_lock);
609 			return;
610 		}
611 
612 		llc = mtod(m, struct llc *);
613 		llc->llc_dsap = llc->llc_ssap = LLC_SNAP_LSAP;
614 		llc->llc_control = LLC_UI;
615 		bcopy(aarp_org_code, llc->llc_org_code, sizeof(aarp_org_code));
616 		llc->llc_ether_type = htons(ETHERTYPE_AARP);
617 
618 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_spnet,
619 		      sizeof(ea->aarp_spnet));
620 		bcopy(&AA_SAT(aa)->sat_addr.s_net, ea->aarp_tpnet,
621 		      sizeof(ea->aarp_tpnet));
622 		ea->aarp_spnode = ea->aarp_tpnode =
623 		    AA_SAT(aa)->sat_addr.s_node;
624 	} else {
625 		bcopy(etherbroadcastaddr, eh->ether_dhost,
626 		    sizeof(eh->ether_dhost));
627 		eh->ether_type = htons(ETHERTYPE_AARP);
628 		ea->aarp_spa = ea->aarp_tpa = AA_SAT(aa)->sat_addr.s_node;
629 	}
630 
631 #ifdef NETATALKDEBUG
632 	printf("aarp: sending probe for %u.%u\n",
633 	       ntohs(AA_SAT(aa)->sat_addr.s_net),
634 	       AA_SAT(aa)->sat_addr.s_node);
635 #endif	/* NETATALKDEBUG */
636 
637 	sa.sa_len = sizeof(struct sockaddr);
638 	sa.sa_family = AF_UNSPEC;
639 	(*ifp->if_output) (ifp, m, &sa, NULL);	/* XXX */
640 	aa->aa_probcnt--;
641 	mutex_exit(softnet_lock);
642 }
643 
644 void
645 aarp_clean()
646 {
647 	struct aarptab *aat;
648 	int             i;
649 
650 	callout_stop(&aarptimer_callout);
651 	for (i = 0, aat = aarptab; i < AARPTAB_SIZE; i++, aat++)
652 		if (aat->aat_hold)
653 			m_freem(aat->aat_hold);
654 }
655