xref: /netbsd-src/sys/net/if_ethersubr.c (revision 9573504567626934c7ee01c7dce0c4bb1dfe7403)
1 /*	$NetBSD: if_ethersubr.c,v 1.15 1995/09/29 03:37:43 phil Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
36  */
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/protosw.h>
44 #include <sys/socket.h>
45 #include <sys/ioctl.h>
46 #include <sys/errno.h>
47 #include <sys/syslog.h>
48 
49 #include <machine/cpu.h>
50 
51 #include <net/if.h>
52 #include <net/netisr.h>
53 #include <net/route.h>
54 #include <net/if_llc.h>
55 #include <net/if_dl.h>
56 #include <net/if_types.h>
57 
58 #include <netinet/in.h>
59 #ifdef INET
60 #include <netinet/in_var.h>
61 #endif
62 #include <netinet/if_ether.h>
63 
64 #ifdef NS
65 #include <netns/ns.h>
66 #include <netns/ns_if.h>
67 #endif
68 
69 #ifdef ISO
70 #include <netiso/argo_debug.h>
71 #include <netiso/iso.h>
72 #include <netiso/iso_var.h>
73 #include <netiso/iso_snpac.h>
74 #endif
75 
76 #ifdef LLC
77 #include <netccitt/dll.h>
78 #include <netccitt/llc_var.h>
79 #endif
80 
81 #if defined(LLC) && defined(CCITT)
82 extern struct ifqueue pkintrq;
83 #endif
84 
85 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
86 #define senderr(e) { error = (e); goto bad;}
87 
88 /*
89  * Ethernet output routine.
90  * Encapsulate a packet of type family for the local net.
91  * Use trailer local net encapsulation if enough data in first
92  * packet leaves a multiple of 512 bytes of data in remainder.
93  * Assumes that ifp is actually pointer to arpcom structure.
94  */
95 int
96 ether_output(ifp, m0, dst, rt0)
97 	register struct ifnet *ifp;
98 	struct mbuf *m0;
99 	struct sockaddr *dst;
100 	struct rtentry *rt0;
101 {
102 	u_int16_t etype;
103 	int s, error = 0;
104  	u_char edst[6];
105 	register struct mbuf *m = m0;
106 	register struct rtentry *rt;
107 	struct mbuf *mcopy = (struct mbuf *)0;
108 	register struct ether_header *eh;
109 	struct arpcom *ac = (struct arpcom *)ifp;
110 
111 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
112 		senderr(ENETDOWN);
113 	ifp->if_lastchange = time;
114 	if (rt = rt0) {
115 		if ((rt->rt_flags & RTF_UP) == 0) {
116 			if (rt0 = rt = rtalloc1(dst, 1))
117 				rt->rt_refcnt--;
118 			else
119 				senderr(EHOSTUNREACH);
120 		}
121 		if (rt->rt_flags & RTF_GATEWAY) {
122 			if (rt->rt_gwroute == 0)
123 				goto lookup;
124 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
125 				rtfree(rt); rt = rt0;
126 			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
127 				if ((rt = rt->rt_gwroute) == 0)
128 					senderr(EHOSTUNREACH);
129 			}
130 		}
131 		if (rt->rt_flags & RTF_REJECT)
132 			if (rt->rt_rmx.rmx_expire == 0 ||
133 			    time.tv_sec < rt->rt_rmx.rmx_expire)
134 				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
135 	}
136 	switch (dst->sa_family) {
137 
138 #ifdef INET
139 	case AF_INET:
140 		if (!arpresolve(ac, rt, m, dst, edst))
141 			return (0);	/* if not yet resolved */
142 		/* If broadcasting on a simplex interface, loopback a copy */
143 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
144 			mcopy = m_copy(m, 0, (int)M_COPYALL);
145 		etype = ETHERTYPE_IP;
146 		break;
147 #endif
148 #ifdef NS
149 	case AF_NS:
150 		etype = ETHERTYPE_NS;
151  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
152 		    (caddr_t)edst, sizeof (edst));
153 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
154 			return (looutput(ifp, m, dst, rt));
155 		/* If broadcasting on a simplex interface, loopback a copy */
156 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
157 			mcopy = m_copy(m, 0, (int)M_COPYALL);
158 		break;
159 #endif
160 #ifdef	ISO
161 	case AF_ISO: {
162 		int	snpalen;
163 		struct	llc *l;
164 		register struct sockaddr_dl *sdl;
165 
166 		if (rt && (sdl = (struct sockaddr_dl *)rt->rt_gateway) &&
167 		    sdl->sdl_family == AF_LINK && sdl->sdl_alen > 0) {
168 			bcopy(LLADDR(sdl), (caddr_t)edst, sizeof(edst));
169 		} else if (error =
170 			    iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
171 					    (char *)edst, &snpalen))
172 			goto bad; /* Not Resolved */
173 		/* If broadcasting on a simplex interface, loopback a copy */
174 		if (*edst & 1)
175 			m->m_flags |= (M_BCAST|M_MCAST);
176 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX) &&
177 		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
178 			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
179 			if (mcopy) {
180 				eh = mtod(mcopy, struct ether_header *);
181 				bcopy((caddr_t)edst,
182 				      (caddr_t)eh->ether_dhost, sizeof (edst));
183 				bcopy((caddr_t)ac->ac_enaddr,
184 				      (caddr_t)eh->ether_shost, sizeof (edst));
185 			}
186 		}
187 		M_PREPEND(m, 3, M_DONTWAIT);
188 		if (m == NULL)
189 			return (0);
190 		etype = m->m_pkthdr.len;
191 		l = mtod(m, struct llc *);
192 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
193 		l->llc_control = LLC_UI;
194 		IFDEBUG(D_ETHER)
195 			int i;
196 			printf("unoutput: sending pkt to: ");
197 			for (i=0; i<6; i++)
198 				printf("%x ", edst[i] & 0xff);
199 			printf("\n");
200 		ENDDEBUG
201 		} break;
202 #endif /* ISO */
203 #ifdef	LLC
204 /*	case AF_NSAP: */
205 	case AF_CCITT: {
206 		register struct sockaddr_dl *sdl =
207 			(struct sockaddr_dl *) rt -> rt_gateway;
208 
209 		if (sdl && sdl->sdl_family == AF_LINK
210 		    && sdl->sdl_alen > 0) {
211 			bcopy(LLADDR(sdl), (char *)edst,
212 				sizeof(edst));
213 		} else goto bad; /* Not a link interface ? Funny ... */
214 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) &&
215 		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
216 			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
217 			if (mcopy) {
218 				eh = mtod(mcopy, struct ether_header *);
219 				bcopy((caddr_t)edst,
220 				      (caddr_t)eh->ether_dhost, sizeof (edst));
221 				bcopy((caddr_t)ac->ac_enaddr,
222 				      (caddr_t)eh->ether_shost, sizeof (edst));
223 			}
224 		}
225 		etype = m->m_pkthdr.len;
226 #ifdef LLC_DEBUG
227 		{
228 			int i;
229 			register struct llc *l = mtod(m, struct llc *);
230 
231 			printf("ether_output: sending LLC2 pkt to: ");
232 			for (i=0; i<6; i++)
233 				printf("%x ", edst[i] & 0xff);
234 			printf(" len 0x%x dsap 0x%x ssap 0x%x control 0x%x\n",
235 			       etype & 0xff, l->llc_dsap & 0xff, l->llc_ssap &0xff,
236 			       l->llc_control & 0xff);
237 
238 		}
239 #endif /* LLC_DEBUG */
240 		} break;
241 #endif /* LLC */
242 
243 	case AF_UNSPEC:
244 		eh = (struct ether_header *)dst->sa_data;
245  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
246 		/* AF_UNSPEC doesn't swap the byte order of the ether_type. */
247 		etype = ntohs(eh->ether_type);
248 		break;
249 
250 	default:
251 		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
252 			dst->sa_family);
253 		senderr(EAFNOSUPPORT);
254 	}
255 
256 
257 	if (mcopy)
258 		(void) looutput(ifp, mcopy, dst, rt);
259 	/*
260 	 * Add local net header.  If no space in first mbuf,
261 	 * allocate another.
262 	 */
263 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
264 	if (m == 0)
265 		senderr(ENOBUFS);
266 	eh = mtod(m, struct ether_header *);
267 	etype = htons(etype);
268 	bcopy((caddr_t)&etype,(caddr_t)&eh->ether_type,
269 		sizeof(eh->ether_type));
270  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
271  	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
272 	    sizeof(eh->ether_shost));
273 	s = splimp();
274 	/*
275 	 * Queue message on interface, and start output if interface
276 	 * not yet active.
277 	 */
278 	if (IF_QFULL(&ifp->if_snd)) {
279 		IF_DROP(&ifp->if_snd);
280 		splx(s);
281 		senderr(ENOBUFS);
282 	}
283 	ifp->if_obytes += m->m_pkthdr.len;
284 	IF_ENQUEUE(&ifp->if_snd, m);
285 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
286 		(*ifp->if_start)(ifp);
287 	splx(s);
288 	if (m->m_flags & M_MCAST)
289 		ifp->if_omcasts++;
290 	return (error);
291 
292 bad:
293 	if (m)
294 		m_freem(m);
295 	return (error);
296 }
297 
298 /*
299  * Process a received Ethernet packet;
300  * the packet is in the mbuf chain m without
301  * the ether header, which is provided separately.
302  */
303 void
304 ether_input(ifp, eh, m)
305 	struct ifnet *ifp;
306 	register struct ether_header *eh;
307 	struct mbuf *m;
308 {
309 	register struct ifqueue *inq;
310 	register struct llc *l;
311 	u_int16_t etype;
312 	struct arpcom *ac = (struct arpcom *)ifp;
313 	int s;
314 
315 	if ((ifp->if_flags & IFF_UP) == 0) {
316 		m_freem(m);
317 		return;
318 	}
319 	ifp->if_lastchange = time;
320 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
321 	if (eh->ether_dhost[0] & 1) {
322 		if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
323 		    sizeof(etherbroadcastaddr)) == 0)
324 			m->m_flags |= M_BCAST;
325 		else
326 			m->m_flags |= M_MCAST;
327 	}
328 	if (m->m_flags & (M_BCAST|M_MCAST))
329 		ifp->if_imcasts++;
330 
331 	etype = ntohs(eh->ether_type);
332 	switch (etype) {
333 #ifdef INET
334 	case ETHERTYPE_IP:
335 		schednetisr(NETISR_IP);
336 		inq = &ipintrq;
337 		break;
338 
339 	case ETHERTYPE_ARP:
340 		schednetisr(NETISR_ARP);
341 		inq = &arpintrq;
342 		break;
343 
344 	case ETHERTYPE_REVARP:
345 		revarpinput(m);	/* XXX queue? */
346 		return;
347 #endif
348 #ifdef NS
349 	case ETHERTYPE_NS:
350 		schednetisr(NETISR_NS);
351 		inq = &nsintrq;
352 		break;
353 
354 #endif
355 	default:
356 #if defined (ISO) || defined (LLC)
357 		if (etype > ETHERMTU)
358 			goto dropanyway;
359 		l = mtod(m, struct llc *);
360 		switch (l->llc_dsap) {
361 #ifdef	ISO
362 		case LLC_ISO_LSAP:
363 			switch (l->llc_control) {
364 			case LLC_UI:
365 				/* LLC_UI_P forbidden in class 1 service */
366 				if ((l->llc_dsap == LLC_ISO_LSAP) &&
367 				    (l->llc_ssap == LLC_ISO_LSAP)) {
368 					/* LSAP for ISO */
369 					if (m->m_pkthdr.len > etype)
370 						m_adj(m, etype - m->m_pkthdr.len);
371 					m->m_data += 3;		/* XXX */
372 					m->m_len -= 3;		/* XXX */
373 					m->m_pkthdr.len -= 3;	/* XXX */
374 					M_PREPEND(m, sizeof *eh, M_DONTWAIT);
375 					if (m == 0)
376 						return;
377 					*mtod(m, struct ether_header *) = *eh;
378 					IFDEBUG(D_ETHER)
379 						printf("clnp packet");
380 					ENDDEBUG
381 					schednetisr(NETISR_ISO);
382 					inq = &clnlintrq;
383 					break;
384 				}
385 				goto dropanyway;
386 
387 			case LLC_XID:
388 			case LLC_XID_P:
389 				if(m->m_len < 6)
390 					goto dropanyway;
391 				l->llc_window = 0;
392 				l->llc_fid = 9;
393 				l->llc_class = 1;
394 				l->llc_dsap = l->llc_ssap = 0;
395 				/* Fall through to */
396 			case LLC_TEST:
397 			case LLC_TEST_P:
398 			{
399 				struct sockaddr sa;
400 				register struct ether_header *eh2;
401 				int i;
402 				u_char c = l->llc_dsap;
403 
404 				l->llc_dsap = l->llc_ssap;
405 				l->llc_ssap = c;
406 				if (m->m_flags & (M_BCAST | M_MCAST))
407 					bcopy((caddr_t)ac->ac_enaddr,
408 					      (caddr_t)eh->ether_dhost, 6);
409 				sa.sa_family = AF_UNSPEC;
410 				sa.sa_len = sizeof(sa);
411 				eh2 = (struct ether_header *)sa.sa_data;
412 				for (i = 0; i < 6; i++) {
413 					eh2->ether_shost[i] = c = eh->ether_dhost[i];
414 					eh2->ether_dhost[i] =
415 						eh->ether_dhost[i] = eh->ether_shost[i];
416 					eh->ether_shost[i] = c;
417 				}
418 				ifp->if_output(ifp, m, &sa, NULL);
419 				return;
420 			}
421 			default:
422 				m_freem(m);
423 				return;
424 			}
425 			break;
426 #endif /* ISO */
427 #ifdef LLC
428 		case LLC_X25_LSAP:
429 		{
430 			if (m->m_pkthdr.len > etype)
431 				m_adj(m, etype - m->m_pkthdr.len);
432 			M_PREPEND(m, sizeof(struct sdl_hdr) , M_DONTWAIT);
433 			if (m == 0)
434 				return;
435 			if ( !sdl_sethdrif(ifp, eh->ether_shost, LLC_X25_LSAP,
436 					    eh->ether_dhost, LLC_X25_LSAP, 6,
437 					    mtod(m, struct sdl_hdr *)))
438 				panic("ETHER cons addr failure");
439 			mtod(m, struct sdl_hdr *)->sdlhdr_len = etype;
440 #ifdef LLC_DEBUG
441 				printf("llc packet\n");
442 #endif /* LLC_DEBUG */
443 			schednetisr(NETISR_CCITT);
444 			inq = &llcintrq;
445 			break;
446 		}
447 #endif /* LLC */
448 		dropanyway:
449 		default:
450 			m_freem(m);
451 			return;
452 		}
453 #else /* ISO || LLC */
454 	    m_freem(m);
455 	    return;
456 #endif /* ISO || LLC */
457 	}
458 
459 	s = splimp();
460 	if (IF_QFULL(inq)) {
461 		IF_DROP(inq);
462 		m_freem(m);
463 	} else
464 		IF_ENQUEUE(inq, m);
465 	splx(s);
466 }
467 
468 /*
469  * Convert Ethernet address to printable (loggable) representation.
470  */
471 static char digits[] = "0123456789abcdef";
472 char *
473 ether_sprintf(ap)
474 	register u_char *ap;
475 {
476 	register i;
477 	static char etherbuf[18];
478 	register char *cp = etherbuf;
479 
480 	for (i = 0; i < 6; i++) {
481 		*cp++ = digits[*ap >> 4];
482 		*cp++ = digits[*ap++ & 0xf];
483 		*cp++ = ':';
484 	}
485 	*--cp = 0;
486 	return (etherbuf);
487 }
488 
489 /*
490  * Perform common duties while attaching to interface list
491  */
492 void
493 ether_ifattach(ifp)
494 	register struct ifnet *ifp;
495 {
496 	register struct ifaddr *ifa;
497 	register struct sockaddr_dl *sdl;
498 
499 	ifp->if_type = IFT_ETHER;
500 	ifp->if_addrlen = 6;
501 	ifp->if_hdrlen = 14;
502 	ifp->if_mtu = ETHERMTU;
503 	ifp->if_output = ether_output;
504 	for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
505 	    ifa = ifa->ifa_list.tqe_next)
506 		if ((sdl = (struct sockaddr_dl *)ifa->ifa_addr) &&
507 		    sdl->sdl_family == AF_LINK) {
508 			sdl->sdl_type = IFT_ETHER;
509 			sdl->sdl_alen = ifp->if_addrlen;
510 			bcopy((caddr_t)((struct arpcom *)ifp)->ac_enaddr,
511 			      LLADDR(sdl), ifp->if_addrlen);
512 			break;
513 		}
514 	LIST_INIT(&((struct arpcom *)ifp)->ac_multiaddrs);
515 }
516 
517 u_char	ether_ipmulticast_min[6] = { 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 };
518 u_char	ether_ipmulticast_max[6] = { 0x01, 0x00, 0x5e, 0x7f, 0xff, 0xff };
519 /*
520  * Add an Ethernet multicast address or range of addresses to the list for a
521  * given interface.
522  */
523 int
524 ether_addmulti(ifr, ac)
525 	struct ifreq *ifr;
526 	register struct arpcom *ac;
527 {
528 	register struct ether_multi *enm;
529 	struct sockaddr_in *sin;
530 	u_char addrlo[6];
531 	u_char addrhi[6];
532 	int s = splimp();
533 
534 	switch (ifr->ifr_addr.sa_family) {
535 
536 	case AF_UNSPEC:
537 		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
538 		bcopy(addrlo, addrhi, 6);
539 		break;
540 
541 #ifdef INET
542 	case AF_INET:
543 		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
544 		if (sin->sin_addr.s_addr == INADDR_ANY) {
545 			/*
546 			 * An IP address of INADDR_ANY means listen to all
547 			 * of the Ethernet multicast addresses used for IP.
548 			 * (This is for the sake of IP multicast routers.)
549 			 */
550 			bcopy(ether_ipmulticast_min, addrlo, 6);
551 			bcopy(ether_ipmulticast_max, addrhi, 6);
552 		}
553 		else {
554 			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
555 			bcopy(addrlo, addrhi, 6);
556 		}
557 		break;
558 #endif
559 
560 	default:
561 		splx(s);
562 		return (EAFNOSUPPORT);
563 	}
564 
565 	/*
566 	 * Verify that we have valid Ethernet multicast addresses.
567 	 */
568 	if ((addrlo[0] & 0x01) != 1 || (addrhi[0] & 0x01) != 1) {
569 		splx(s);
570 		return (EINVAL);
571 	}
572 	/*
573 	 * See if the address range is already in the list.
574 	 */
575 	ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm);
576 	if (enm != NULL) {
577 		/*
578 		 * Found it; just increment the reference count.
579 		 */
580 		++enm->enm_refcount;
581 		splx(s);
582 		return (0);
583 	}
584 	/*
585 	 * New address or range; malloc a new multicast record
586 	 * and link it into the interface's multicast list.
587 	 */
588 	enm = (struct ether_multi *)malloc(sizeof(*enm), M_IFMADDR, M_NOWAIT);
589 	if (enm == NULL) {
590 		splx(s);
591 		return (ENOBUFS);
592 	}
593 	bcopy(addrlo, enm->enm_addrlo, 6);
594 	bcopy(addrhi, enm->enm_addrhi, 6);
595 	enm->enm_ac = ac;
596 	enm->enm_refcount = 1;
597 	LIST_INSERT_HEAD(&ac->ac_multiaddrs, enm, enm_list);
598 	ac->ac_multicnt++;
599 	splx(s);
600 	/*
601 	 * Return ENETRESET to inform the driver that the list has changed
602 	 * and its reception filter should be adjusted accordingly.
603 	 */
604 	return (ENETRESET);
605 }
606 
607 /*
608  * Delete a multicast address record.
609  */
610 int
611 ether_delmulti(ifr, ac)
612 	struct ifreq *ifr;
613 	register struct arpcom *ac;
614 {
615 	register struct ether_multi *enm;
616 	register struct ether_multi **p;
617 	struct sockaddr_in *sin;
618 	u_char addrlo[6];
619 	u_char addrhi[6];
620 	int s = splimp();
621 
622 	switch (ifr->ifr_addr.sa_family) {
623 
624 	case AF_UNSPEC:
625 		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
626 		bcopy(addrlo, addrhi, 6);
627 		break;
628 
629 #ifdef INET
630 	case AF_INET:
631 		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
632 		if (sin->sin_addr.s_addr == INADDR_ANY) {
633 			/*
634 			 * An IP address of INADDR_ANY means stop listening
635 			 * to the range of Ethernet multicast addresses used
636 			 * for IP.
637 			 */
638 			bcopy(ether_ipmulticast_min, addrlo, 6);
639 			bcopy(ether_ipmulticast_max, addrhi, 6);
640 		}
641 		else {
642 			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
643 			bcopy(addrlo, addrhi, 6);
644 		}
645 		break;
646 #endif
647 
648 	default:
649 		splx(s);
650 		return (EAFNOSUPPORT);
651 	}
652 
653 	/*
654 	 * Look up the address in our list.
655 	 */
656 	ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm);
657 	if (enm == NULL) {
658 		splx(s);
659 		return (ENXIO);
660 	}
661 	if (--enm->enm_refcount != 0) {
662 		/*
663 		 * Still some claims to this record.
664 		 */
665 		splx(s);
666 		return (0);
667 	}
668 	/*
669 	 * No remaining claims to this record; unlink and free it.
670 	 */
671 	LIST_REMOVE(enm, enm_list);
672 	free(enm, M_IFMADDR);
673 	ac->ac_multicnt--;
674 	splx(s);
675 	/*
676 	 * Return ENETRESET to inform the driver that the list has changed
677 	 * and its reception filter should be adjusted accordingly.
678 	 */
679 	return (ENETRESET);
680 }
681