xref: /freebsd/sys/net/if_ethersubr.c (revision 05c7a37afb48ddd5ee1bd921a5d46fe59cc70b15)
1 /*
2  * Copyright (c) 1982, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
34  * $Id: if_ethersubr.c,v 1.14 1996/01/24 21:09:06 phk Exp $
35  */
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/kernel.h>
40 #include <sys/malloc.h>
41 #include <sys/mbuf.h>
42 #include <sys/protosw.h>
43 #include <sys/socket.h>
44 #include <sys/ioctl.h>
45 #include <sys/errno.h>
46 #include <sys/syslog.h>
47 #include <sys/sysctl.h>
48 
49 #include <net/if.h>
50 #include <net/netisr.h>
51 #include <net/route.h>
52 #include <net/if_llc.h>
53 #include <net/if_dl.h>
54 #include <net/if_types.h>
55 
56 #ifdef INET
57 #include <netinet/in.h>
58 #include <netinet/in_var.h>
59 #endif
60 #include <netinet/if_ether.h>
61 
62 #ifdef IPX
63 #include <netipx/ipx.h>
64 #include <netipx/ipx_if.h>
65 #endif
66 
67 #ifdef NS
68 #include <netns/ns.h>
69 #include <netns/ns_if.h>
70 #endif
71 
72 #ifdef ISO
73 #include <netiso/argo_debug.h>
74 #include <netiso/iso.h>
75 #include <netiso/iso_var.h>
76 #include <netiso/iso_snpac.h>
77 #endif
78 
79 #ifdef LLC
80 #include <netccitt/dll.h>
81 #include <netccitt/llc_var.h>
82 #endif
83 
84 #if defined(LLC) && defined(CCITT)
85 extern struct ifqueue pkintrq;
86 #endif
87 
88 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
89 #define senderr(e) { error = (e); goto bad;}
90 
91 /*
92  * Ethernet output routine.
93  * Encapsulate a packet of type family for the local net.
94  * Use trailer local net encapsulation if enough data in first
95  * packet leaves a multiple of 512 bytes of data in remainder.
96  * Assumes that ifp is actually pointer to arpcom structure.
97  */
98 int
99 ether_output(ifp, m0, dst, rt0)
100 	register struct ifnet *ifp;
101 	struct mbuf *m0;
102 	struct sockaddr *dst;
103 	struct rtentry *rt0;
104 {
105 	short type;
106 	int s, error = 0;
107  	u_char edst[6];
108 	register struct mbuf *m = m0;
109 	register struct rtentry *rt;
110 	struct mbuf *mcopy = (struct mbuf *)0;
111 	register struct ether_header *eh;
112 	int off, len = m->m_pkthdr.len;
113 	struct arpcom *ac = (struct arpcom *)ifp;
114 
115 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
116 		senderr(ENETDOWN);
117 	ifp->if_lastchange = time;
118 	rt = rt0;
119 	if (rt) {
120 		if ((rt->rt_flags & RTF_UP) == 0) {
121 			rt0 = rt = rtalloc1(dst, 1, 0UL);
122 			if (rt0)
123 				rt->rt_refcnt--;
124 			else
125 				senderr(EHOSTUNREACH);
126 		}
127 		if (rt->rt_flags & RTF_GATEWAY) {
128 			if (rt->rt_gwroute == 0)
129 				goto lookup;
130 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
131 				rtfree(rt); rt = rt0;
132 			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1,
133 							  0UL);
134 				if ((rt = rt->rt_gwroute) == 0)
135 					senderr(EHOSTUNREACH);
136 			}
137 		}
138 		if (rt->rt_flags & RTF_REJECT)
139 			if (rt->rt_rmx.rmx_expire == 0 ||
140 			    time.tv_sec < rt->rt_rmx.rmx_expire)
141 				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
142 	}
143 	switch (dst->sa_family) {
144 
145 #ifdef INET
146 	case AF_INET:
147 		if (!arpresolve(ac, rt, m, dst, edst, rt0))
148 			return (0);	/* if not yet resolved */
149 		/* If broadcasting on a simplex interface, loopback a copy */
150 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
151 			mcopy = m_copy(m, 0, (int)M_COPYALL);
152 		off = m->m_pkthdr.len - m->m_len;
153 		type = ETHERTYPE_IP;
154 		break;
155 #endif
156 #ifdef IPX
157 	case AF_IPX:
158 		type = ETHERTYPE_IPX;
159  		bcopy((caddr_t)&(((struct sockaddr_ipx *)dst)->sipx_addr.x_host),
160 		    (caddr_t)edst, sizeof (edst));
161 		if (!bcmp((caddr_t)edst, (caddr_t)&ipx_thishost, sizeof(edst)))
162 			return (looutput(ifp, m, dst, rt));
163 		/* If broadcasting on a simplex interface, loopback a copy */
164 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
165 			mcopy = m_copy(m, 0, (int)M_COPYALL);
166 		break;
167 #endif
168 #ifdef NS
169 	case AF_NS:
170 		type = ETHERTYPE_NS;
171  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
172 		    (caddr_t)edst, sizeof (edst));
173 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
174 			return (looutput(ifp, m, dst, rt));
175 		/* If broadcasting on a simplex interface, loopback a copy */
176 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
177 			mcopy = m_copy(m, 0, (int)M_COPYALL);
178 		break;
179 #endif
180 #ifdef	ISO
181 	case AF_ISO: {
182 		int	snpalen;
183 		struct	llc *l;
184 		register struct sockaddr_dl *sdl;
185 
186 		if (rt && (sdl = (struct sockaddr_dl *)rt->rt_gateway) &&
187 		    sdl->sdl_family == AF_LINK && sdl->sdl_alen > 0) {
188 			bcopy(LLADDR(sdl), (caddr_t)edst, sizeof(edst));
189 		} else if (error =
190 			    iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
191 					    (char *)edst, &snpalen))
192 			goto bad; /* Not Resolved */
193 		/* If broadcasting on a simplex interface, loopback a copy */
194 		if (*edst & 1)
195 			m->m_flags |= (M_BCAST|M_MCAST);
196 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX) &&
197 		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
198 			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
199 			if (mcopy) {
200 				eh = mtod(mcopy, struct ether_header *);
201 				bcopy((caddr_t)edst,
202 				      (caddr_t)eh->ether_dhost, sizeof (edst));
203 				bcopy((caddr_t)ac->ac_enaddr,
204 				      (caddr_t)eh->ether_shost, sizeof (edst));
205 			}
206 		}
207 		M_PREPEND(m, 3, M_DONTWAIT);
208 		if (m == NULL)
209 			return (0);
210 		type = m->m_pkthdr.len;
211 		l = mtod(m, struct llc *);
212 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
213 		l->llc_control = LLC_UI;
214 		len += 3;
215 		IFDEBUG(D_ETHER)
216 			int i;
217 			printf("unoutput: sending pkt to: ");
218 			for (i=0; i<6; i++)
219 				printf("%x ", edst[i] & 0xff);
220 			printf("\n");
221 		ENDDEBUG
222 		} break;
223 #endif /* ISO */
224 #ifdef	LLC
225 /*	case AF_NSAP: */
226 	case AF_CCITT: {
227 		register struct sockaddr_dl *sdl =
228 			(struct sockaddr_dl *) rt -> rt_gateway;
229 
230 		if (sdl && sdl->sdl_family == AF_LINK
231 		    && sdl->sdl_alen > 0) {
232 			bcopy(LLADDR(sdl), (char *)edst,
233 				sizeof(edst));
234 		} else goto bad; /* Not a link interface ? Funny ... */
235 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) &&
236 		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
237 			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
238 			if (mcopy) {
239 				eh = mtod(mcopy, struct ether_header *);
240 				bcopy((caddr_t)edst,
241 				      (caddr_t)eh->ether_dhost, sizeof (edst));
242 				bcopy((caddr_t)ac->ac_enaddr,
243 				      (caddr_t)eh->ether_shost, sizeof (edst));
244 			}
245 		}
246 		type = m->m_pkthdr.len;
247 #ifdef LLC_DEBUG
248 		{
249 			int i;
250 			register struct llc *l = mtod(m, struct llc *);
251 
252 			printf("ether_output: sending LLC2 pkt to: ");
253 			for (i=0; i<6; i++)
254 				printf("%x ", edst[i] & 0xff);
255 			printf(" len 0x%x dsap 0x%x ssap 0x%x control 0x%x\n",
256 			       type & 0xff, l->llc_dsap & 0xff, l->llc_ssap &0xff,
257 			       l->llc_control & 0xff);
258 
259 		}
260 #endif /* LLC_DEBUG */
261 		} break;
262 #endif /* LLC */
263 
264 	case AF_UNSPEC:
265 		eh = (struct ether_header *)dst->sa_data;
266  		(void)memcpy(edst, eh->ether_dhost, sizeof (edst));
267 		type = eh->ether_type;
268 		break;
269 
270 	default:
271 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
272 			dst->sa_family);
273 		senderr(EAFNOSUPPORT);
274 	}
275 
276 
277 	if (mcopy)
278 		(void) looutput(ifp, mcopy, dst, rt);
279 	/*
280 	 * Add local net header.  If no space in first mbuf,
281 	 * allocate another.
282 	 */
283 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
284 	if (m == 0)
285 		senderr(ENOBUFS);
286 	eh = mtod(m, struct ether_header *);
287 	type = htons((u_short)type);
288 	(void)memcpy(&eh->ether_type, &type,
289 		sizeof(eh->ether_type));
290  	(void)memcpy(eh->ether_dhost, edst, sizeof (edst));
291  	(void)memcpy(eh->ether_shost, ac->ac_enaddr,
292 	    sizeof(eh->ether_shost));
293 	s = splimp();
294 	/*
295 	 * Queue message on interface, and start output if interface
296 	 * not yet active.
297 	 */
298 	if (IF_QFULL(&ifp->if_snd)) {
299 		IF_DROP(&ifp->if_snd);
300 		splx(s);
301 		senderr(ENOBUFS);
302 	}
303 	IF_ENQUEUE(&ifp->if_snd, m);
304 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
305 		(*ifp->if_start)(ifp);
306 	splx(s);
307 	ifp->if_obytes += len + sizeof (struct ether_header);
308 	if (m->m_flags & M_MCAST)
309 		ifp->if_omcasts++;
310 	return (error);
311 
312 bad:
313 	if (m)
314 		m_freem(m);
315 	return (error);
316 }
317 
318 /*
319  * Process a received Ethernet packet;
320  * the packet is in the mbuf chain m without
321  * the ether header, which is provided separately.
322  */
323 void
324 ether_input(ifp, eh, m)
325 	struct ifnet *ifp;
326 	register struct ether_header *eh;
327 	struct mbuf *m;
328 {
329 	register struct ifqueue *inq;
330 	register struct llc *l;
331 	u_short ether_type;
332 	int s;
333 
334 	if ((ifp->if_flags & IFF_UP) == 0) {
335 		m_freem(m);
336 		return;
337 	}
338 	ifp->if_lastchange = time;
339 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
340 	if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
341 	    sizeof(etherbroadcastaddr)) == 0)
342 		m->m_flags |= M_BCAST;
343 	else if (eh->ether_dhost[0] & 1)
344 		m->m_flags |= M_MCAST;
345 	if (m->m_flags & (M_BCAST|M_MCAST))
346 		ifp->if_imcasts++;
347 
348 	ether_type = ntohs(eh->ether_type);
349 
350 	switch (ether_type) {
351 #ifdef INET
352 	case ETHERTYPE_IP:
353 		schednetisr(NETISR_IP);
354 		inq = &ipintrq;
355 		break;
356 
357 	case ETHERTYPE_ARP:
358 		schednetisr(NETISR_ARP);
359 		inq = &arpintrq;
360 		break;
361 #endif
362 #ifdef IPX
363 	case ETHERTYPE_IPX:
364 		schednetisr(NETISR_IPX);
365 		inq = &ipxintrq;
366 		break;
367 #endif
368 #ifdef NS
369 	case ETHERTYPE_NS:
370 		schednetisr(NETISR_NS);
371 		inq = &nsintrq;
372 		break;
373 #endif
374 	default:
375 #if defined (ISO) || defined (LLC)
376 		if (ether_type > ETHERMTU)
377 			goto dropanyway;
378 		l = mtod(m, struct llc *);
379 		switch (l->llc_dsap) {
380 #ifdef	ISO
381 		case LLC_ISO_LSAP:
382 			switch (l->llc_control) {
383 			case LLC_UI:
384 				/* LLC_UI_P forbidden in class 1 service */
385 				if ((l->llc_dsap == LLC_ISO_LSAP) &&
386 				    (l->llc_ssap == LLC_ISO_LSAP)) {
387 					/* LSAP for ISO */
388 					if (m->m_pkthdr.len > ether_type)
389 						m_adj(m, ether_type - m->m_pkthdr.len);
390 					m->m_data += 3;		/* XXX */
391 					m->m_len -= 3;		/* XXX */
392 					m->m_pkthdr.len -= 3;	/* XXX */
393 					M_PREPEND(m, sizeof *eh, M_DONTWAIT);
394 					if (m == 0)
395 						return;
396 					*mtod(m, struct ether_header *) = *eh;
397 					IFDEBUG(D_ETHER)
398 						printf("clnp packet");
399 					ENDDEBUG
400 					schednetisr(NETISR_ISO);
401 					inq = &clnlintrq;
402 					break;
403 				}
404 				goto dropanyway;
405 
406 			case LLC_XID:
407 			case LLC_XID_P:
408 				if(m->m_len < 6)
409 					goto dropanyway;
410 				l->llc_window = 0;
411 				l->llc_fid = 9;
412 				l->llc_class = 1;
413 				l->llc_dsap = l->llc_ssap = 0;
414 				/* Fall through to */
415 			case LLC_TEST:
416 			case LLC_TEST_P:
417 			{
418 				struct sockaddr sa;
419 				register struct ether_header *eh2;
420 				int i;
421 				u_char c = l->llc_dsap;
422 
423 				l->llc_dsap = l->llc_ssap;
424 				l->llc_ssap = c;
425 				if (m->m_flags & (M_BCAST | M_MCAST))
426 					bcopy((caddr_t)ac->ac_enaddr,
427 					      (caddr_t)eh->ether_dhost, 6);
428 				sa.sa_family = AF_UNSPEC;
429 				sa.sa_len = sizeof(sa);
430 				eh2 = (struct ether_header *)sa.sa_data;
431 				for (i = 0; i < 6; i++) {
432 					eh2->ether_shost[i] = c = eh->ether_dhost[i];
433 					eh2->ether_dhost[i] =
434 						eh->ether_dhost[i] = eh->ether_shost[i];
435 					eh->ether_shost[i] = c;
436 				}
437 				ifp->if_output(ifp, m, &sa, NULL);
438 				return;
439 			}
440 			default:
441 				m_freem(m);
442 				return;
443 			}
444 			break;
445 #endif /* ISO */
446 #ifdef LLC
447 		case LLC_X25_LSAP:
448 		{
449 			if (m->m_pkthdr.len > ether_type)
450 				m_adj(m, ether_type - m->m_pkthdr.len);
451 			M_PREPEND(m, sizeof(struct sdl_hdr) , M_DONTWAIT);
452 			if (m == 0)
453 				return;
454 			if ( !sdl_sethdrif(ifp, eh->ether_shost, LLC_X25_LSAP,
455 					    eh->ether_dhost, LLC_X25_LSAP, 6,
456 					    mtod(m, struct sdl_hdr *)))
457 				panic("ETHER cons addr failure");
458 			mtod(m, struct sdl_hdr *)->sdlhdr_len = ether_type;
459 #ifdef LLC_DEBUG
460 				printf("llc packet\n");
461 #endif /* LLC_DEBUG */
462 			schednetisr(NETISR_CCITT);
463 			inq = &llcintrq;
464 			break;
465 		}
466 #endif /* LLC */
467 		dropanyway:
468 		default:
469 			m_freem(m);
470 			return;
471 		}
472 #else /* ISO || LLC */
473 	    m_freem(m);
474 	    return;
475 #endif /* ISO || LLC */
476 	}
477 
478 	s = splimp();
479 	if (IF_QFULL(inq)) {
480 		IF_DROP(inq);
481 		m_freem(m);
482 	} else
483 		IF_ENQUEUE(inq, m);
484 	splx(s);
485 }
486 
487 /*
488  * Perform common duties while attaching to interface list
489  */
490 void
491 ether_ifattach(ifp)
492 	register struct ifnet *ifp;
493 {
494 	register struct ifaddr *ifa;
495 	register struct sockaddr_dl *sdl;
496 
497 	ifp->if_type = IFT_ETHER;
498 	ifp->if_addrlen = 6;
499 	ifp->if_hdrlen = 14;
500 	ifp->if_mtu = ETHERMTU;
501 	for (ifa = ifp->if_addrlist; ifa; ifa = ifa->ifa_next)
502 		if ((sdl = (struct sockaddr_dl *)ifa->ifa_addr) &&
503 		    sdl->sdl_family == AF_LINK) {
504 			sdl->sdl_type = IFT_ETHER;
505 			sdl->sdl_alen = ifp->if_addrlen;
506 			bcopy((caddr_t)((struct arpcom *)ifp)->ac_enaddr,
507 			      LLADDR(sdl), ifp->if_addrlen);
508 			break;
509 		}
510 }
511 
512 static u_char ether_ipmulticast_min[6] =
513 	{ 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 };
514 static u_char ether_ipmulticast_max[6] =
515 	{ 0x01, 0x00, 0x5e, 0x7f, 0xff, 0xff };
516 /*
517  * Add an Ethernet multicast address or range of addresses to the list for a
518  * given interface.
519  */
520 int
521 ether_addmulti(ifr, ac)
522 	struct ifreq *ifr;
523 	register struct arpcom *ac;
524 {
525 	register struct ether_multi *enm;
526 	struct sockaddr_in *sin;
527 	u_char addrlo[6];
528 	u_char addrhi[6];
529       int set_allmulti = 0;
530 	int s = splimp();
531 
532 	switch (ifr->ifr_addr.sa_family) {
533 
534 	case AF_UNSPEC:
535 		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
536 		bcopy(addrlo, addrhi, 6);
537 		break;
538 
539 #ifdef INET
540 	case AF_INET:
541 		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
542 		if (sin->sin_addr.s_addr == INADDR_ANY) {
543 			/*
544 			 * An IP address of INADDR_ANY means listen to all
545 			 * of the Ethernet multicast addresses used for IP.
546 			 * (This is for the sake of IP multicast routers.)
547 			 */
548 			bcopy(ether_ipmulticast_min, addrlo, 6);
549 			bcopy(ether_ipmulticast_max, addrhi, 6);
550                       set_allmulti = 1;
551 		}
552 		else {
553 			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
554 			bcopy(addrlo, addrhi, 6);
555 		}
556 		break;
557 #endif
558 
559 	default:
560 		splx(s);
561 		return (EAFNOSUPPORT);
562 	}
563 
564 	/*
565 	 * Verify that we have valid Ethernet multicast addresses.
566 	 */
567 	if ((addrlo[0] & 0x01) != 1 || (addrhi[0] & 0x01) != 1) {
568 		splx(s);
569 		return (EINVAL);
570 	}
571 	/*
572 	 * See if the address range is already in the list.
573 	 */
574 	ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm);
575 	if (enm != NULL) {
576 		/*
577 		 * Found it; just increment the reference count.
578 		 */
579 		++enm->enm_refcount;
580 		splx(s);
581 		return (0);
582 	}
583 	/*
584 	 * New address or range; malloc a new multicast record
585 	 * and link it into the interface's multicast list.
586 	 */
587 	enm = (struct ether_multi *)malloc(sizeof(*enm), M_IFMADDR, M_NOWAIT);
588 	if (enm == NULL) {
589 		splx(s);
590 		return (ENOBUFS);
591 	}
592 	bcopy(addrlo, enm->enm_addrlo, 6);
593 	bcopy(addrhi, enm->enm_addrhi, 6);
594 	enm->enm_ac = ac;
595 	enm->enm_refcount = 1;
596 	enm->enm_next = ac->ac_multiaddrs;
597 	ac->ac_multiaddrs = enm;
598 	ac->ac_multicnt++;
599 	splx(s);
600       if (set_allmulti)
601               ac->ac_if.if_flags |= IFF_ALLMULTI;
602 
603 	/*
604 	 * Return ENETRESET to inform the driver that the list has changed
605 	 * and its reception filter should be adjusted accordingly.
606 	 */
607 	return (ENETRESET);
608 }
609 
610 /*
611  * Delete a multicast address record.
612  */
613 int
614 ether_delmulti(ifr, ac)
615 	struct ifreq *ifr;
616 	register struct arpcom *ac;
617 {
618 	register struct ether_multi *enm;
619 	register struct ether_multi **p;
620 	struct sockaddr_in *sin;
621 	u_char addrlo[6];
622 	u_char addrhi[6];
623       int unset_allmulti = 0;
624 	int s = splimp();
625 
626 	switch (ifr->ifr_addr.sa_family) {
627 
628 	case AF_UNSPEC:
629 		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
630 		bcopy(addrlo, addrhi, 6);
631 		break;
632 
633 #ifdef INET
634 	case AF_INET:
635 		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
636 		if (sin->sin_addr.s_addr == INADDR_ANY) {
637 			/*
638 			 * An IP address of INADDR_ANY means stop listening
639 			 * to the range of Ethernet multicast addresses used
640 			 * for IP.
641 			 */
642 			bcopy(ether_ipmulticast_min, addrlo, 6);
643 			bcopy(ether_ipmulticast_max, addrhi, 6);
644                       unset_allmulti = 1;
645 		}
646 		else {
647 			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
648 			bcopy(addrlo, addrhi, 6);
649 		}
650 		break;
651 #endif
652 
653 	default:
654 		splx(s);
655 		return (EAFNOSUPPORT);
656 	}
657 
658 	/*
659 	 * Look up the address in our list.
660 	 */
661 	ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm);
662 	if (enm == NULL) {
663 		splx(s);
664 		return (ENXIO);
665 	}
666 	if (--enm->enm_refcount != 0) {
667 		/*
668 		 * Still some claims to this record.
669 		 */
670 		splx(s);
671 		return (0);
672 	}
673 	/*
674 	 * No remaining claims to this record; unlink and free it.
675 	 */
676 	for (p = &enm->enm_ac->ac_multiaddrs;
677 	     *p != enm;
678 	     p = &(*p)->enm_next)
679 		continue;
680 	*p = (*p)->enm_next;
681 	free(enm, M_IFMADDR);
682 	ac->ac_multicnt--;
683 	splx(s);
684       if (unset_allmulti)
685               ac->ac_if.if_flags &= ~IFF_ALLMULTI;
686 
687 	/*
688 	 * Return ENETRESET to inform the driver that the list has changed
689 	 * and its reception filter should be adjusted accordingly.
690 	 */
691 	return (ENETRESET);
692 }
693 
694 SYSCTL_NODE(_net_link, IFT_ETHER, ether, CTLFLAG_RW, 0, "Ethernet");
695