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if_ethersubr.c revision 1.22
      1 /*	$NetBSD: if_ethersubr.c,v 1.22 1997/03/15 18:12:26 is 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 <net/if_ether.h>
     59 
     60 #include <netinet/in.h>
     61 #ifdef INET
     62 #include <netinet/in_var.h>
     63 #endif
     64 #include <netinet/if_inarp.h>
     65 
     66 #ifdef NS
     67 #include <netns/ns.h>
     68 #include <netns/ns_if.h>
     69 #endif
     70 
     71 #ifdef ISO
     72 #include <netiso/argo_debug.h>
     73 #include <netiso/iso.h>
     74 #include <netiso/iso_var.h>
     75 #include <netiso/iso_snpac.h>
     76 #endif
     77 
     78 #ifdef LLC
     79 #include <netccitt/dll.h>
     80 #include <netccitt/llc_var.h>
     81 #endif
     82 
     83 #if defined(LLC) && defined(CCITT)
     84 extern struct ifqueue pkintrq;
     85 #endif
     86 
     87 u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
     88 #define senderr(e) { error = (e); goto bad;}
     89 
     90 #define SIN(x) ((struct sockaddr_in *)x)
     91 
     92 /*
     93  * Ethernet output routine.
     94  * Encapsulate a packet of type family for the local net.
     95  * Assumes that ifp is actually pointer to ethercom structure.
     96  */
     97 int
     98 ether_output(ifp, m0, dst, rt0)
     99 	register struct ifnet *ifp;
    100 	struct mbuf *m0;
    101 	struct sockaddr *dst;
    102 	struct rtentry *rt0;
    103 {
    104 	u_int16_t etype;
    105 	int s, error = 0;
    106  	u_char edst[6];
    107 	register struct mbuf *m = m0;
    108 	register struct rtentry *rt;
    109 	struct mbuf *mcopy = (struct mbuf *)0;
    110 	register struct ether_header *eh;
    111 	struct arphdr *ah;
    112 
    113 	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
    114 		senderr(ENETDOWN);
    115 	ifp->if_lastchange = time;
    116 	if ((rt = rt0) != NULL) {
    117 		if ((rt->rt_flags & RTF_UP) == 0) {
    118 			if ((rt0 = rt = rtalloc1(dst, 1)) != NULL)
    119 				rt->rt_refcnt--;
    120 			else
    121 				senderr(EHOSTUNREACH);
    122 		}
    123 		if (rt->rt_flags & RTF_GATEWAY) {
    124 			if (rt->rt_gwroute == 0)
    125 				goto lookup;
    126 			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
    127 				rtfree(rt); rt = rt0;
    128 			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
    129 				if ((rt = rt->rt_gwroute) == 0)
    130 					senderr(EHOSTUNREACH);
    131 			}
    132 		}
    133 		if (rt->rt_flags & RTF_REJECT)
    134 			if (rt->rt_rmx.rmx_expire == 0 ||
    135 			    time.tv_sec < rt->rt_rmx.rmx_expire)
    136 				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
    137 	}
    138 	switch (dst->sa_family) {
    139 
    140 #ifdef INET
    141 	case AF_INET:
    142 		if (m->m_flags & M_BCAST)
    143                 	bcopy((caddr_t)etherbroadcastaddr, (caddr_t)edst,
    144 				sizeof(edst));
    145 
    146 		else if (m->m_flags & M_MCAST) {
    147 			ETHER_MAP_IP_MULTICAST(&SIN(dst)->sin_addr,
    148 			    (caddr_t)edst)
    149 
    150 		} else if (!arpresolve(ifp, rt, m, dst, edst))
    151 			return (0);	/* if not yet resolved */
    152 		/* If broadcasting on a simplex interface, loopback a copy */
    153 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
    154 			mcopy = m_copy(m, 0, (int)M_COPYALL);
    155 		etype = htons(ETHERTYPE_IP);
    156 		break;
    157 
    158 	case AF_ARP:
    159 		ah = mtod(m, struct arphdr *);
    160 		if (m->m_flags & M_BCAST)
    161                 	bcopy((caddr_t)etherbroadcastaddr, (caddr_t)edst,
    162 				sizeof(edst));
    163 		else
    164 			bcopy((caddr_t)ar_tha(ah),
    165 				(caddr_t)edst, sizeof(edst));
    166 
    167 		ah->ar_hrd = htons(ARPHRD_ETHER);
    168 
    169 		switch(ntohs(ah->ar_op)) {
    170 		case ARPOP_REVREQUEST:
    171 		case ARPOP_REVREPLY:
    172 			etype = htons(ETHERTYPE_REVARP);
    173 			break;
    174 
    175 		case ARPOP_REQUEST:
    176 		case ARPOP_REPLY:
    177 		default:
    178 			etype = htons(ETHERTYPE_ARP);
    179 		}
    180 
    181 		break;
    182 #endif
    183 #ifdef NS
    184 	case AF_NS:
    185 		etype = htons(ETHERTYPE_NS);
    186  		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
    187 		    (caddr_t)edst, sizeof (edst));
    188 		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
    189 			return (looutput(ifp, m, dst, rt));
    190 		/* If broadcasting on a simplex interface, loopback a copy */
    191 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
    192 			mcopy = m_copy(m, 0, (int)M_COPYALL);
    193 		break;
    194 #endif
    195 #ifdef	ISO
    196 	case AF_ISO: {
    197 		int	snpalen;
    198 		struct	llc *l;
    199 		register struct sockaddr_dl *sdl;
    200 
    201 		if (rt && (sdl = (struct sockaddr_dl *)rt->rt_gateway) &&
    202 		    sdl->sdl_family == AF_LINK && sdl->sdl_alen > 0) {
    203 			bcopy(LLADDR(sdl), (caddr_t)edst, sizeof(edst));
    204 		} else {
    205 			error = iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
    206 						(char *)edst, &snpalen);
    207 			if (error)
    208 				goto bad; /* Not Resolved */
    209 		}
    210 		/* If broadcasting on a simplex interface, loopback a copy */
    211 		if (*edst & 1)
    212 			m->m_flags |= (M_BCAST|M_MCAST);
    213 		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX) &&
    214 		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
    215 			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
    216 			if (mcopy) {
    217 				eh = mtod(mcopy, struct ether_header *);
    218 				bcopy((caddr_t)edst,
    219 				      (caddr_t)eh->ether_dhost, sizeof (edst));
    220 				bcopy(LLADDR(ifp->if_sadl),
    221 				      (caddr_t)eh->ether_shost, sizeof (edst));
    222 			}
    223 		}
    224 		M_PREPEND(m, 3, M_DONTWAIT);
    225 		if (m == NULL)
    226 			return (0);
    227 		etype = htons(m->m_pkthdr.len);
    228 		l = mtod(m, struct llc *);
    229 		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
    230 		l->llc_control = LLC_UI;
    231 #ifdef ARGO_DEBUG
    232 		if (argo_debug[D_ETHER]) {
    233 			int i;
    234 			printf("unoutput: sending pkt to: ");
    235 			for (i=0; i<6; i++)
    236 				printf("%x ", edst[i] & 0xff);
    237 			printf("\n");
    238 		}
    239 #endif
    240 		} break;
    241 #endif /* ISO */
    242 #ifdef	LLC
    243 /*	case AF_NSAP: */
    244 	case AF_CCITT: {
    245 		register struct sockaddr_dl *sdl =
    246 			(struct sockaddr_dl *) rt -> rt_gateway;
    247 
    248 		if (sdl && sdl->sdl_family == AF_LINK
    249 		    && sdl->sdl_alen > 0) {
    250 			bcopy(LLADDR(sdl), (char *)edst,
    251 				sizeof(edst));
    252 		} else goto bad; /* Not a link interface ? Funny ... */
    253 		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) &&
    254 		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
    255 			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
    256 			if (mcopy) {
    257 				eh = mtod(mcopy, struct ether_header *);
    258 				bcopy((caddr_t)edst,
    259 				      (caddr_t)eh->ether_dhost, sizeof (edst));
    260 				bcopy(LLADDR(ifp->if_sadl),
    261 				      (caddr_t)eh->ether_shost, sizeof (edst));
    262 			}
    263 		}
    264 		etype = htons(m->m_pkthdr.len);
    265 #ifdef LLC_DEBUG
    266 		{
    267 			int i;
    268 			register struct llc *l = mtod(m, struct llc *);
    269 
    270 			printf("ether_output: sending LLC2 pkt to: ");
    271 			for (i=0; i<6; i++)
    272 				printf("%x ", edst[i] & 0xff);
    273 			printf(" len 0x%x dsap 0x%x ssap 0x%x control 0x%x\n",
    274 			    m->m_pkthdr.len, l->llc_dsap & 0xff, l->llc_ssap &0xff,
    275 			    l->llc_control & 0xff);
    276 
    277 		}
    278 #endif /* LLC_DEBUG */
    279 		} break;
    280 #endif /* LLC */
    281 
    282 	case AF_UNSPEC:
    283 		eh = (struct ether_header *)dst->sa_data;
    284  		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
    285 		/* AF_UNSPEC doesn't swap the byte order of the ether_type. */
    286 		etype = eh->ether_type;
    287 		break;
    288 
    289 	default:
    290 		printf("%s: can't handle af%d\n", ifp->if_xname,
    291 			dst->sa_family);
    292 		senderr(EAFNOSUPPORT);
    293 	}
    294 
    295 	if (mcopy)
    296 		(void) looutput(ifp, mcopy, dst, rt);
    297 
    298 	/*
    299 	 * Add local net header.  If no space in first mbuf,
    300 	 * allocate another.
    301 	 */
    302 	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
    303 	if (m == 0)
    304 		senderr(ENOBUFS);
    305 	eh = mtod(m, struct ether_header *);
    306 	bcopy((caddr_t)&etype,(caddr_t)&eh->ether_type,
    307 		sizeof(eh->ether_type));
    308  	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
    309  	bcopy(LLADDR(ifp->if_sadl), (caddr_t)eh->ether_shost,
    310 	    sizeof(eh->ether_shost));
    311 	s = splimp();
    312 	/*
    313 	 * Queue message on interface, and start output if interface
    314 	 * not yet active.
    315 	 */
    316 	if (IF_QFULL(&ifp->if_snd)) {
    317 		IF_DROP(&ifp->if_snd);
    318 		splx(s);
    319 		senderr(ENOBUFS);
    320 	}
    321 	ifp->if_obytes += m->m_pkthdr.len;
    322 	IF_ENQUEUE(&ifp->if_snd, m);
    323 	if ((ifp->if_flags & IFF_OACTIVE) == 0)
    324 		(*ifp->if_start)(ifp);
    325 	splx(s);
    326 	if (m->m_flags & M_MCAST)
    327 		ifp->if_omcasts++;
    328 	return (error);
    329 
    330 bad:
    331 	if (m)
    332 		m_freem(m);
    333 	return (error);
    334 }
    335 
    336 /*
    337  * Process a received Ethernet packet;
    338  * the packet is in the mbuf chain m without
    339  * the ether header, which is provided separately.
    340  */
    341 void
    342 ether_input(ifp, eh, m)
    343 	struct ifnet *ifp;
    344 	register struct ether_header *eh;
    345 	struct mbuf *m;
    346 {
    347 	register struct ifqueue *inq;
    348 	u_int16_t etype;
    349 	int s;
    350 #if defined (ISO) || defined (LLC)
    351 	register struct llc *l;
    352 #endif
    353 
    354 	if ((ifp->if_flags & IFF_UP) == 0) {
    355 		m_freem(m);
    356 		return;
    357 	}
    358 	ifp->if_lastchange = time;
    359 	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
    360 	if (eh->ether_dhost[0] & 1) {
    361 		if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
    362 		    sizeof(etherbroadcastaddr)) == 0)
    363 			m->m_flags |= M_BCAST;
    364 		else
    365 			m->m_flags |= M_MCAST;
    366 	}
    367 	if (m->m_flags & (M_BCAST|M_MCAST))
    368 		ifp->if_imcasts++;
    369 
    370 	etype = ntohs(eh->ether_type);
    371 	switch (etype) {
    372 #ifdef INET
    373 	case ETHERTYPE_IP:
    374 		schednetisr(NETISR_IP);
    375 		inq = &ipintrq;
    376 		break;
    377 
    378 	case ETHERTYPE_ARP:
    379 		schednetisr(NETISR_ARP);
    380 		inq = &arpintrq;
    381 		break;
    382 
    383 	case ETHERTYPE_REVARP:
    384 		revarpinput(m);	/* XXX queue? */
    385 		return;
    386 #endif
    387 #ifdef NS
    388 	case ETHERTYPE_NS:
    389 		schednetisr(NETISR_NS);
    390 		inq = &nsintrq;
    391 		break;
    392 
    393 #endif
    394 	default:
    395 #if defined (ISO) || defined (LLC)
    396 		if (etype > ETHERMTU)
    397 			goto dropanyway;
    398 		l = mtod(m, struct llc *);
    399 		switch (l->llc_dsap) {
    400 #ifdef	ISO
    401 		case LLC_ISO_LSAP:
    402 			switch (l->llc_control) {
    403 			case LLC_UI:
    404 				/* LLC_UI_P forbidden in class 1 service */
    405 				if ((l->llc_dsap == LLC_ISO_LSAP) &&
    406 				    (l->llc_ssap == LLC_ISO_LSAP)) {
    407 					/* LSAP for ISO */
    408 					if (m->m_pkthdr.len > etype)
    409 						m_adj(m, etype - m->m_pkthdr.len);
    410 					m->m_data += 3;		/* XXX */
    411 					m->m_len -= 3;		/* XXX */
    412 					m->m_pkthdr.len -= 3;	/* XXX */
    413 					M_PREPEND(m, sizeof *eh, M_DONTWAIT);
    414 					if (m == 0)
    415 						return;
    416 					*mtod(m, struct ether_header *) = *eh;
    417 #ifdef ARGO_DEBUG
    418 					if (argo_debug[D_ETHER])
    419 						printf("clnp packet");
    420 #endif
    421 					schednetisr(NETISR_ISO);
    422 					inq = &clnlintrq;
    423 					break;
    424 				}
    425 				goto dropanyway;
    426 
    427 			case LLC_XID:
    428 			case LLC_XID_P:
    429 				if(m->m_len < 6)
    430 					goto dropanyway;
    431 				l->llc_window = 0;
    432 				l->llc_fid = 9;
    433 				l->llc_class = 1;
    434 				l->llc_dsap = l->llc_ssap = 0;
    435 				/* Fall through to */
    436 			case LLC_TEST:
    437 			case LLC_TEST_P:
    438 			{
    439 				struct sockaddr sa;
    440 				register struct ether_header *eh2;
    441 				int i;
    442 				u_char c = l->llc_dsap;
    443 
    444 				l->llc_dsap = l->llc_ssap;
    445 				l->llc_ssap = c;
    446 				if (m->m_flags & (M_BCAST | M_MCAST))
    447 					bcopy(LLADDR(ifp->if_sadl),
    448 					      (caddr_t)eh->ether_dhost, 6);
    449 				sa.sa_family = AF_UNSPEC;
    450 				sa.sa_len = sizeof(sa);
    451 				eh2 = (struct ether_header *)sa.sa_data;
    452 				for (i = 0; i < 6; i++) {
    453 					eh2->ether_shost[i] = c =
    454 					    eh->ether_dhost[i];
    455 					eh2->ether_dhost[i] =
    456 					    eh->ether_dhost[i] =
    457 					    eh->ether_shost[i];
    458 					eh->ether_shost[i] = c;
    459 				}
    460 				ifp->if_output(ifp, m, &sa, NULL);
    461 				return;
    462 			}
    463 			default:
    464 				m_freem(m);
    465 				return;
    466 			}
    467 			break;
    468 #endif /* ISO */
    469 #ifdef LLC
    470 		case LLC_X25_LSAP:
    471 		{
    472 			if (m->m_pkthdr.len > etype)
    473 				m_adj(m, etype - m->m_pkthdr.len);
    474 			M_PREPEND(m, sizeof(struct sdl_hdr) , M_DONTWAIT);
    475 			if (m == 0)
    476 				return;
    477 			if ( !sdl_sethdrif(ifp, eh->ether_shost, LLC_X25_LSAP,
    478 					    eh->ether_dhost, LLC_X25_LSAP, 6,
    479 					    mtod(m, struct sdl_hdr *)))
    480 				panic("ETHER cons addr failure");
    481 			mtod(m, struct sdl_hdr *)->sdlhdr_len = etype;
    482 #ifdef LLC_DEBUG
    483 				printf("llc packet\n");
    484 #endif /* LLC_DEBUG */
    485 			schednetisr(NETISR_CCITT);
    486 			inq = &llcintrq;
    487 			break;
    488 		}
    489 #endif /* LLC */
    490 		dropanyway:
    491 		default:
    492 			m_freem(m);
    493 			return;
    494 		}
    495 #else /* ISO || LLC */
    496 	    m_freem(m);
    497 	    return;
    498 #endif /* ISO || LLC */
    499 	}
    500 
    501 	s = splimp();
    502 	if (IF_QFULL(inq)) {
    503 		IF_DROP(inq);
    504 		m_freem(m);
    505 	} else
    506 		IF_ENQUEUE(inq, m);
    507 	splx(s);
    508 }
    509 
    510 /*
    511  * Convert Ethernet address to printable (loggable) representation.
    512  */
    513 static char digits[] = "0123456789abcdef";
    514 char *
    515 ether_sprintf(ap)
    516 	register u_char *ap;
    517 {
    518 	register i;
    519 	static char etherbuf[18];
    520 	register char *cp = etherbuf;
    521 
    522 	for (i = 0; i < 6; i++) {
    523 		*cp++ = digits[*ap >> 4];
    524 		*cp++ = digits[*ap++ & 0xf];
    525 		*cp++ = ':';
    526 	}
    527 	*--cp = 0;
    528 	return (etherbuf);
    529 }
    530 
    531 /*
    532  * Perform common duties while attaching to interface list
    533  */
    534 void
    535 ether_ifattach(ifp, lla)
    536 	register struct ifnet *ifp;
    537 	u_int8_t * lla;
    538 {
    539 	register struct sockaddr_dl *sdl;
    540 
    541 	ifp->if_type = IFT_ETHER;
    542 	ifp->if_addrlen = 6;
    543 	ifp->if_hdrlen = 14;
    544 	ifp->if_mtu = ETHERMTU;
    545 	ifp->if_output = ether_output;
    546 	if ((sdl = ifp->if_sadl) &&
    547 	    sdl->sdl_family == AF_LINK) {
    548 		sdl->sdl_type = IFT_ETHER;
    549 		sdl->sdl_alen = ifp->if_addrlen;
    550 		bcopy((caddr_t)lla, LLADDR(sdl), ifp->if_addrlen);
    551 	}
    552 	LIST_INIT(&((struct ethercom *)ifp)->ec_multiaddrs);
    553 }
    554 
    555 u_char	ether_ipmulticast_min[6] = { 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 };
    556 u_char	ether_ipmulticast_max[6] = { 0x01, 0x00, 0x5e, 0x7f, 0xff, 0xff };
    557 /*
    558  * Add an Ethernet multicast address or range of addresses to the list for a
    559  * given interface.
    560  */
    561 int
    562 ether_addmulti(ifr, ec)
    563 	struct ifreq *ifr;
    564 	register struct ethercom *ec;
    565 {
    566 	register struct ether_multi *enm;
    567 	struct sockaddr_in *sin;
    568 	u_char addrlo[6];
    569 	u_char addrhi[6];
    570 	int s = splimp();
    571 
    572 	switch (ifr->ifr_addr.sa_family) {
    573 
    574 	case AF_UNSPEC:
    575 		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
    576 		bcopy(addrlo, addrhi, 6);
    577 		break;
    578 
    579 #ifdef INET
    580 	case AF_INET:
    581 		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
    582 		if (sin->sin_addr.s_addr == INADDR_ANY) {
    583 			/*
    584 			 * An IP address of INADDR_ANY means listen to all
    585 			 * of the Ethernet multicast addresses used for IP.
    586 			 * (This is for the sake of IP multicast routers.)
    587 			 */
    588 			bcopy(ether_ipmulticast_min, addrlo, 6);
    589 			bcopy(ether_ipmulticast_max, addrhi, 6);
    590 		}
    591 		else {
    592 			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
    593 			bcopy(addrlo, addrhi, 6);
    594 		}
    595 		break;
    596 #endif
    597 
    598 	default:
    599 		splx(s);
    600 		return (EAFNOSUPPORT);
    601 	}
    602 
    603 	/*
    604 	 * Verify that we have valid Ethernet multicast addresses.
    605 	 */
    606 	if ((addrlo[0] & 0x01) != 1 || (addrhi[0] & 0x01) != 1) {
    607 		splx(s);
    608 		return (EINVAL);
    609 	}
    610 	/*
    611 	 * See if the address range is already in the list.
    612 	 */
    613 	ETHER_LOOKUP_MULTI(addrlo, addrhi, ec, enm);
    614 	if (enm != NULL) {
    615 		/*
    616 		 * Found it; just increment the reference count.
    617 		 */
    618 		++enm->enm_refcount;
    619 		splx(s);
    620 		return (0);
    621 	}
    622 	/*
    623 	 * New address or range; malloc a new multicast record
    624 	 * and link it into the interface's multicast list.
    625 	 */
    626 	enm = (struct ether_multi *)malloc(sizeof(*enm), M_IFMADDR, M_NOWAIT);
    627 	if (enm == NULL) {
    628 		splx(s);
    629 		return (ENOBUFS);
    630 	}
    631 	bcopy(addrlo, enm->enm_addrlo, 6);
    632 	bcopy(addrhi, enm->enm_addrhi, 6);
    633 	enm->enm_ec = ec;
    634 	enm->enm_refcount = 1;
    635 	LIST_INSERT_HEAD(&ec->ec_multiaddrs, enm, enm_list);
    636 	ec->ec_multicnt++;
    637 	splx(s);
    638 	/*
    639 	 * Return ENETRESET to inform the driver that the list has changed
    640 	 * and its reception filter should be adjusted accordingly.
    641 	 */
    642 	return (ENETRESET);
    643 }
    644 
    645 /*
    646  * Delete a multicast address record.
    647  */
    648 int
    649 ether_delmulti(ifr, ec)
    650 	struct ifreq *ifr;
    651 	register struct ethercom *ec;
    652 {
    653 	register struct ether_multi *enm;
    654 	struct sockaddr_in *sin;
    655 	u_char addrlo[6];
    656 	u_char addrhi[6];
    657 	int s = splimp();
    658 
    659 	switch (ifr->ifr_addr.sa_family) {
    660 
    661 	case AF_UNSPEC:
    662 		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
    663 		bcopy(addrlo, addrhi, 6);
    664 		break;
    665 
    666 #ifdef INET
    667 	case AF_INET:
    668 		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
    669 		if (sin->sin_addr.s_addr == INADDR_ANY) {
    670 			/*
    671 			 * An IP address of INADDR_ANY means stop listening
    672 			 * to the range of Ethernet multicast addresses used
    673 			 * for IP.
    674 			 */
    675 			bcopy(ether_ipmulticast_min, addrlo, 6);
    676 			bcopy(ether_ipmulticast_max, addrhi, 6);
    677 		}
    678 		else {
    679 			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
    680 			bcopy(addrlo, addrhi, 6);
    681 		}
    682 		break;
    683 #endif
    684 
    685 	default:
    686 		splx(s);
    687 		return (EAFNOSUPPORT);
    688 	}
    689 
    690 	/*
    691 	 * Look up the address in our list.
    692 	 */
    693 	ETHER_LOOKUP_MULTI(addrlo, addrhi, ec, enm);
    694 	if (enm == NULL) {
    695 		splx(s);
    696 		return (ENXIO);
    697 	}
    698 	if (--enm->enm_refcount != 0) {
    699 		/*
    700 		 * Still some claims to this record.
    701 		 */
    702 		splx(s);
    703 		return (0);
    704 	}
    705 	/*
    706 	 * No remaining claims to this record; unlink and free it.
    707 	 */
    708 	LIST_REMOVE(enm, enm_list);
    709 	free(enm, M_IFMADDR);
    710 	ec->ec_multicnt--;
    711 	splx(s);
    712 	/*
    713 	 * Return ENETRESET to inform the driver that the list has changed
    714 	 * and its reception filter should be adjusted accordingly.
    715 	 */
    716 	return (ENETRESET);
    717 }
    718