initial import of NetBSD tree

1 files changed, 680 insertions, 0 deletions

diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
new file mode 100644
index 00000000000..d777c51669f
--- /dev/null
+++ b/sys/net/if_ethersubr.c
@@ -0,0 +1,680 @@
+/*	$NetBSD: if_ethersubr.c,v 1.15 1995/09/29 03:37:43 phil Exp $	*/
+
+/*
+ * Copyright (c) 1982, 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)if_ethersubr.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <sys/errno.h>
+#include <sys/syslog.h>
+
+#include <machine/cpu.h>
+
+#include <net/if.h>
+#include <net/netisr.h>
+#include <net/route.h>
+#include <net/if_llc.h>
+#include <net/if_dl.h>
+#include <net/if_types.h>
+
+#include <netinet/in.h>
+#ifdef INET
+#include <netinet/in_var.h>
+#endif
+#include <netinet/if_ether.h>
+
+#ifdef NS
+#include <netns/ns.h>
+#include <netns/ns_if.h>
+#endif
+
+#ifdef ISO
+#include <netiso/argo_debug.h>
+#include <netiso/iso.h>
+#include <netiso/iso_var.h>
+#include <netiso/iso_snpac.h>
+#endif
+
+#ifdef LLC
+#include <netccitt/dll.h>
+#include <netccitt/llc_var.h>
+#endif
+
+#if defined(LLC) && defined(CCITT)
+extern struct ifqueue pkintrq;
+#endif
+
+u_char	etherbroadcastaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
+#define senderr(e) { error = (e); goto bad;}
+
+/*
+ * Ethernet output routine.
+ * Encapsulate a packet of type family for the local net.
+ * Use trailer local net encapsulation if enough data in first
+ * packet leaves a multiple of 512 bytes of data in remainder.
+ * Assumes that ifp is actually pointer to arpcom structure.
+ */
+int
+ether_output(ifp, m0, dst, rt0)
+	register struct ifnet *ifp;
+	struct mbuf *m0;
+	struct sockaddr *dst;
+	struct rtentry *rt0;
+{
+	u_int16_t etype;
+	int s, error = 0;
+ 	u_char edst[6];
+	register struct mbuf *m = m0;
+	register struct rtentry *rt;
+	struct mbuf *mcopy = (struct mbuf *)0;
+	register struct ether_header *eh;
+	struct arpcom *ac = (struct arpcom *)ifp;
+
+	if ((ifp->if_flags & (IFF_UP|IFF_RUNNING)) != (IFF_UP|IFF_RUNNING))
+		senderr(ENETDOWN);
+	ifp->if_lastchange = time;
+	if (rt = rt0) {
+		if ((rt->rt_flags & RTF_UP) == 0) {
+			if (rt0 = rt = rtalloc1(dst, 1))
+				rt->rt_refcnt--;
+			else 
+				senderr(EHOSTUNREACH);
+		}
+		if (rt->rt_flags & RTF_GATEWAY) {
+			if (rt->rt_gwroute == 0)
+				goto lookup;
+			if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
+				rtfree(rt); rt = rt0;
+			lookup: rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
+				if ((rt = rt->rt_gwroute) == 0)
+					senderr(EHOSTUNREACH);
+			}
+		}
+		if (rt->rt_flags & RTF_REJECT)
+			if (rt->rt_rmx.rmx_expire == 0 ||
+			    time.tv_sec < rt->rt_rmx.rmx_expire)
+				senderr(rt == rt0 ? EHOSTDOWN : EHOSTUNREACH);
+	}
+	switch (dst->sa_family) {
+
+#ifdef INET
+	case AF_INET:
+		if (!arpresolve(ac, rt, m, dst, edst))
+			return (0);	/* if not yet resolved */
+		/* If broadcasting on a simplex interface, loopback a copy */
+		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
+			mcopy = m_copy(m, 0, (int)M_COPYALL);
+		etype = ETHERTYPE_IP;
+		break;
+#endif
+#ifdef NS
+	case AF_NS:
+		etype = ETHERTYPE_NS;
+ 		bcopy((caddr_t)&(((struct sockaddr_ns *)dst)->sns_addr.x_host),
+		    (caddr_t)edst, sizeof (edst));
+		if (!bcmp((caddr_t)edst, (caddr_t)&ns_thishost, sizeof(edst)))
+			return (looutput(ifp, m, dst, rt));
+		/* If broadcasting on a simplex interface, loopback a copy */
+		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX))
+			mcopy = m_copy(m, 0, (int)M_COPYALL);
+		break;
+#endif
+#ifdef	ISO
+	case AF_ISO: {
+		int	snpalen;
+		struct	llc *l;
+		register struct sockaddr_dl *sdl;
+
+		if (rt && (sdl = (struct sockaddr_dl *)rt->rt_gateway) &&
+		    sdl->sdl_family == AF_LINK && sdl->sdl_alen > 0) {
+			bcopy(LLADDR(sdl), (caddr_t)edst, sizeof(edst));
+		} else if (error =
+			    iso_snparesolve(ifp, (struct sockaddr_iso *)dst,
+					    (char *)edst, &snpalen))
+			goto bad; /* Not Resolved */
+		/* If broadcasting on a simplex interface, loopback a copy */
+		if (*edst & 1)
+			m->m_flags |= (M_BCAST|M_MCAST);
+		if ((m->m_flags & M_BCAST) && (ifp->if_flags & IFF_SIMPLEX) &&
+		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
+			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
+			if (mcopy) {
+				eh = mtod(mcopy, struct ether_header *);
+				bcopy((caddr_t)edst,
+				      (caddr_t)eh->ether_dhost, sizeof (edst));
+				bcopy((caddr_t)ac->ac_enaddr,
+				      (caddr_t)eh->ether_shost, sizeof (edst));
+			}
+		}
+		M_PREPEND(m, 3, M_DONTWAIT);
+		if (m == NULL)
+			return (0);
+		etype = m->m_pkthdr.len;
+		l = mtod(m, struct llc *);
+		l->llc_dsap = l->llc_ssap = LLC_ISO_LSAP;
+		l->llc_control = LLC_UI;
+		IFDEBUG(D_ETHER)
+			int i;
+			printf("unoutput: sending pkt to: ");
+			for (i=0; i<6; i++)
+				printf("%x ", edst[i] & 0xff);
+			printf("\n");
+		ENDDEBUG
+		} break;
+#endif /* ISO */
+#ifdef	LLC
+/*	case AF_NSAP: */
+	case AF_CCITT: {
+		register struct sockaddr_dl *sdl = 
+			(struct sockaddr_dl *) rt -> rt_gateway;
+
+		if (sdl && sdl->sdl_family == AF_LINK
+		    && sdl->sdl_alen > 0) {
+			bcopy(LLADDR(sdl), (char *)edst,
+				sizeof(edst));
+		} else goto bad; /* Not a link interface ? Funny ... */
+		if ((ifp->if_flags & IFF_SIMPLEX) && (*edst & 1) &&
+		    (mcopy = m_copy(m, 0, (int)M_COPYALL))) {
+			M_PREPEND(mcopy, sizeof (*eh), M_DONTWAIT);
+			if (mcopy) {
+				eh = mtod(mcopy, struct ether_header *);
+				bcopy((caddr_t)edst,
+				      (caddr_t)eh->ether_dhost, sizeof (edst));
+				bcopy((caddr_t)ac->ac_enaddr,
+				      (caddr_t)eh->ether_shost, sizeof (edst));
+			}
+		}
+		etype = m->m_pkthdr.len;
+#ifdef LLC_DEBUG
+		{
+			int i;
+			register struct llc *l = mtod(m, struct llc *);
+
+			printf("ether_output: sending LLC2 pkt to: ");
+			for (i=0; i<6; i++)
+				printf("%x ", edst[i] & 0xff);
+			printf(" len 0x%x dsap 0x%x ssap 0x%x control 0x%x\n", 
+			       etype & 0xff, l->llc_dsap & 0xff, l->llc_ssap &0xff,
+			       l->llc_control & 0xff);
+
+		}
+#endif /* LLC_DEBUG */
+		} break;
+#endif /* LLC */	
+
+	case AF_UNSPEC:
+		eh = (struct ether_header *)dst->sa_data;
+ 		bcopy((caddr_t)eh->ether_dhost, (caddr_t)edst, sizeof (edst));
+		/* AF_UNSPEC doesn't swap the byte order of the ether_type. */
+		etype = ntohs(eh->ether_type);
+		break;
+
+	default:
+		printf("%s%d: can't handle af%d\n", ifp->if_name, ifp->if_unit,
+			dst->sa_family);
+		senderr(EAFNOSUPPORT);
+	}
+
+
+	if (mcopy)
+		(void) looutput(ifp, mcopy, dst, rt);
+	/*
+	 * Add local net header.  If no space in first mbuf,
+	 * allocate another.
+	 */
+	M_PREPEND(m, sizeof (struct ether_header), M_DONTWAIT);
+	if (m == 0)
+		senderr(ENOBUFS);
+	eh = mtod(m, struct ether_header *);
+	etype = htons(etype);
+	bcopy((caddr_t)&etype,(caddr_t)&eh->ether_type,
+		sizeof(eh->ether_type));
+ 	bcopy((caddr_t)edst, (caddr_t)eh->ether_dhost, sizeof (edst));
+ 	bcopy((caddr_t)ac->ac_enaddr, (caddr_t)eh->ether_shost,
+	    sizeof(eh->ether_shost));
+	s = splimp();
+	/*
+	 * Queue message on interface, and start output if interface
+	 * not yet active.
+	 */
+	if (IF_QFULL(&ifp->if_snd)) {
+		IF_DROP(&ifp->if_snd);
+		splx(s);
+		senderr(ENOBUFS);
+	}
+	ifp->if_obytes += m->m_pkthdr.len;
+	IF_ENQUEUE(&ifp->if_snd, m);
+	if ((ifp->if_flags & IFF_OACTIVE) == 0)
+		(*ifp->if_start)(ifp);
+	splx(s);
+	if (m->m_flags & M_MCAST)
+		ifp->if_omcasts++;
+	return (error);
+
+bad:
+	if (m)
+		m_freem(m);
+	return (error);
+}
+
+/*
+ * Process a received Ethernet packet;
+ * the packet is in the mbuf chain m without
+ * the ether header, which is provided separately.
+ */
+void
+ether_input(ifp, eh, m)
+	struct ifnet *ifp;
+	register struct ether_header *eh;
+	struct mbuf *m;
+{
+	register struct ifqueue *inq;
+	register struct llc *l;
+	u_int16_t etype;
+	struct arpcom *ac = (struct arpcom *)ifp;
+	int s;
+
+	if ((ifp->if_flags & IFF_UP) == 0) {
+		m_freem(m);
+		return;
+	}
+	ifp->if_lastchange = time;
+	ifp->if_ibytes += m->m_pkthdr.len + sizeof (*eh);
+	if (eh->ether_dhost[0] & 1) {
+		if (bcmp((caddr_t)etherbroadcastaddr, (caddr_t)eh->ether_dhost,
+		    sizeof(etherbroadcastaddr)) == 0)
+			m->m_flags |= M_BCAST;
+		else
+			m->m_flags |= M_MCAST;
+	}
+	if (m->m_flags & (M_BCAST|M_MCAST))
+		ifp->if_imcasts++;
+
+	etype = ntohs(eh->ether_type);
+	switch (etype) {
+#ifdef INET
+	case ETHERTYPE_IP:
+		schednetisr(NETISR_IP);
+		inq = &ipintrq;
+		break;
+
+	case ETHERTYPE_ARP:
+		schednetisr(NETISR_ARP);
+		inq = &arpintrq;
+		break;
+
+	case ETHERTYPE_REVARP:
+		revarpinput(m);	/* XXX queue? */
+		return;
+#endif
+#ifdef NS
+	case ETHERTYPE_NS:
+		schednetisr(NETISR_NS);
+		inq = &nsintrq;
+		break;
+
+#endif
+	default:
+#if defined (ISO) || defined (LLC)
+		if (etype > ETHERMTU)
+			goto dropanyway;
+		l = mtod(m, struct llc *);
+		switch (l->llc_dsap) {
+#ifdef	ISO
+		case LLC_ISO_LSAP: 
+			switch (l->llc_control) {
+			case LLC_UI:
+				/* LLC_UI_P forbidden in class 1 service */
+				if ((l->llc_dsap == LLC_ISO_LSAP) &&
+				    (l->llc_ssap == LLC_ISO_LSAP)) {
+					/* LSAP for ISO */
+					if (m->m_pkthdr.len > etype)
+						m_adj(m, etype - m->m_pkthdr.len);
+					m->m_data += 3;		/* XXX */
+					m->m_len -= 3;		/* XXX */
+					m->m_pkthdr.len -= 3;	/* XXX */
+					M_PREPEND(m, sizeof *eh, M_DONTWAIT);
+					if (m == 0)
+						return;
+					*mtod(m, struct ether_header *) = *eh;
+					IFDEBUG(D_ETHER)
+						printf("clnp packet");
+					ENDDEBUG
+					schednetisr(NETISR_ISO);
+					inq = &clnlintrq;
+					break;
+				}
+				goto dropanyway;
+				
+			case LLC_XID:
+			case LLC_XID_P:
+				if(m->m_len < 6)
+					goto dropanyway;
+				l->llc_window = 0;
+				l->llc_fid = 9;
+				l->llc_class = 1;
+				l->llc_dsap = l->llc_ssap = 0;
+				/* Fall through to */
+			case LLC_TEST:
+			case LLC_TEST_P:
+			{
+				struct sockaddr sa;
+				register struct ether_header *eh2;
+				int i;
+				u_char c = l->llc_dsap;
+
+				l->llc_dsap = l->llc_ssap;
+				l->llc_ssap = c;
+				if (m->m_flags & (M_BCAST | M_MCAST))
+					bcopy((caddr_t)ac->ac_enaddr,
+					      (caddr_t)eh->ether_dhost, 6);
+				sa.sa_family = AF_UNSPEC;
+				sa.sa_len = sizeof(sa);
+				eh2 = (struct ether_header *)sa.sa_data;
+				for (i = 0; i < 6; i++) {
+					eh2->ether_shost[i] = c = eh->ether_dhost[i];
+					eh2->ether_dhost[i] = 
+						eh->ether_dhost[i] = eh->ether_shost[i];
+					eh->ether_shost[i] = c;
+				}
+				ifp->if_output(ifp, m, &sa, NULL);
+				return;
+			}
+			default:
+				m_freem(m);
+				return;
+			}
+			break;
+#endif /* ISO */
+#ifdef LLC
+		case LLC_X25_LSAP:
+		{
+			if (m->m_pkthdr.len > etype)
+				m_adj(m, etype - m->m_pkthdr.len);
+			M_PREPEND(m, sizeof(struct sdl_hdr) , M_DONTWAIT);
+			if (m == 0)
+				return;
+			if ( !sdl_sethdrif(ifp, eh->ether_shost, LLC_X25_LSAP,
+					    eh->ether_dhost, LLC_X25_LSAP, 6, 
+					    mtod(m, struct sdl_hdr *)))
+				panic("ETHER cons addr failure");
+			mtod(m, struct sdl_hdr *)->sdlhdr_len = etype;
+#ifdef LLC_DEBUG
+				printf("llc packet\n");
+#endif /* LLC_DEBUG */
+			schednetisr(NETISR_CCITT);
+			inq = &llcintrq;
+			break;
+		}
+#endif /* LLC */
+		dropanyway:
+		default:
+			m_freem(m);
+			return;
+		}
+#else /* ISO || LLC */
+	    m_freem(m);
+	    return;
+#endif /* ISO || LLC */
+	}
+
+	s = splimp();
+	if (IF_QFULL(inq)) {
+		IF_DROP(inq);
+		m_freem(m);
+	} else
+		IF_ENQUEUE(inq, m);
+	splx(s);
+}
+
+/*
+ * Convert Ethernet address to printable (loggable) representation.
+ */
+static char digits[] = "0123456789abcdef";
+char *
+ether_sprintf(ap)
+	register u_char *ap;
+{
+	register i;
+	static char etherbuf[18];
+	register char *cp = etherbuf;
+
+	for (i = 0; i < 6; i++) {
+		*cp++ = digits[*ap >> 4];
+		*cp++ = digits[*ap++ & 0xf];
+		*cp++ = ':';
+	}
+	*--cp = 0;
+	return (etherbuf);
+}
+
+/*
+ * Perform common duties while attaching to interface list
+ */
+void
+ether_ifattach(ifp)
+	register struct ifnet *ifp;
+{
+	register struct ifaddr *ifa;
+	register struct sockaddr_dl *sdl;
+
+	ifp->if_type = IFT_ETHER;
+	ifp->if_addrlen = 6;
+	ifp->if_hdrlen = 14;
+	ifp->if_mtu = ETHERMTU;
+	ifp->if_output = ether_output;
+	for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
+	    ifa = ifa->ifa_list.tqe_next)
+		if ((sdl = (struct sockaddr_dl *)ifa->ifa_addr) &&
+		    sdl->sdl_family == AF_LINK) {
+			sdl->sdl_type = IFT_ETHER;
+			sdl->sdl_alen = ifp->if_addrlen;
+			bcopy((caddr_t)((struct arpcom *)ifp)->ac_enaddr,
+			      LLADDR(sdl), ifp->if_addrlen);
+			break;
+		}
+	LIST_INIT(&((struct arpcom *)ifp)->ac_multiaddrs);
+}
+
+u_char	ether_ipmulticast_min[6] = { 0x01, 0x00, 0x5e, 0x00, 0x00, 0x00 };
+u_char	ether_ipmulticast_max[6] = { 0x01, 0x00, 0x5e, 0x7f, 0xff, 0xff };
+/*
+ * Add an Ethernet multicast address or range of addresses to the list for a
+ * given interface.
+ */
+int
+ether_addmulti(ifr, ac)
+	struct ifreq *ifr;
+	register struct arpcom *ac;
+{
+	register struct ether_multi *enm;
+	struct sockaddr_in *sin;
+	u_char addrlo[6];
+	u_char addrhi[6];
+	int s = splimp();
+
+	switch (ifr->ifr_addr.sa_family) {
+
+	case AF_UNSPEC:
+		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
+		bcopy(addrlo, addrhi, 6);
+		break;
+
+#ifdef INET
+	case AF_INET:
+		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
+		if (sin->sin_addr.s_addr == INADDR_ANY) {
+			/*
+			 * An IP address of INADDR_ANY means listen to all
+			 * of the Ethernet multicast addresses used for IP.
+			 * (This is for the sake of IP multicast routers.)
+			 */
+			bcopy(ether_ipmulticast_min, addrlo, 6);
+			bcopy(ether_ipmulticast_max, addrhi, 6);
+		}
+		else {
+			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
+			bcopy(addrlo, addrhi, 6);
+		}
+		break;
+#endif
+
+	default:
+		splx(s);
+		return (EAFNOSUPPORT);
+	}
+
+	/*
+	 * Verify that we have valid Ethernet multicast addresses.
+	 */
+	if ((addrlo[0] & 0x01) != 1 || (addrhi[0] & 0x01) != 1) {
+		splx(s);
+		return (EINVAL);
+	}
+	/*
+	 * See if the address range is already in the list.
+	 */
+	ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm);
+	if (enm != NULL) {
+		/*
+		 * Found it; just increment the reference count.
+		 */
+		++enm->enm_refcount;
+		splx(s);
+		return (0);
+	}
+	/*
+	 * New address or range; malloc a new multicast record
+	 * and link it into the interface's multicast list.
+	 */
+	enm = (struct ether_multi *)malloc(sizeof(*enm), M_IFMADDR, M_NOWAIT);
+	if (enm == NULL) {
+		splx(s);
+		return (ENOBUFS);
+	}
+	bcopy(addrlo, enm->enm_addrlo, 6);
+	bcopy(addrhi, enm->enm_addrhi, 6);
+	enm->enm_ac = ac;
+	enm->enm_refcount = 1;
+	LIST_INSERT_HEAD(&ac->ac_multiaddrs, enm, enm_list);
+	ac->ac_multicnt++;
+	splx(s);
+	/*
+	 * Return ENETRESET to inform the driver that the list has changed
+	 * and its reception filter should be adjusted accordingly.
+	 */
+	return (ENETRESET);
+}
+
+/*
+ * Delete a multicast address record.
+ */
+int
+ether_delmulti(ifr, ac)
+	struct ifreq *ifr;
+	register struct arpcom *ac;
+{
+	register struct ether_multi *enm;
+	register struct ether_multi **p;
+	struct sockaddr_in *sin;
+	u_char addrlo[6];
+	u_char addrhi[6];
+	int s = splimp();
+
+	switch (ifr->ifr_addr.sa_family) {
+
+	case AF_UNSPEC:
+		bcopy(ifr->ifr_addr.sa_data, addrlo, 6);
+		bcopy(addrlo, addrhi, 6);
+		break;
+
+#ifdef INET
+	case AF_INET:
+		sin = (struct sockaddr_in *)&(ifr->ifr_addr);
+		if (sin->sin_addr.s_addr == INADDR_ANY) {
+			/*
+			 * An IP address of INADDR_ANY means stop listening
+			 * to the range of Ethernet multicast addresses used
+			 * for IP.
+			 */
+			bcopy(ether_ipmulticast_min, addrlo, 6);
+			bcopy(ether_ipmulticast_max, addrhi, 6);
+		}
+		else {
+			ETHER_MAP_IP_MULTICAST(&sin->sin_addr, addrlo);
+			bcopy(addrlo, addrhi, 6);
+		}
+		break;
+#endif
+
+	default:
+		splx(s);
+		return (EAFNOSUPPORT);
+	}
+
+	/*
+	 * Look up the address in our list.
+	 */
+	ETHER_LOOKUP_MULTI(addrlo, addrhi, ac, enm);
+	if (enm == NULL) {
+		splx(s);
+		return (ENXIO);
+	}
+	if (--enm->enm_refcount != 0) {
+		/*
+		 * Still some claims to this record.
+		 */
+		splx(s);
+		return (0);
+	}
+	/*
+	 * No remaining claims to this record; unlink and free it.
+	 */
+	LIST_REMOVE(enm, enm_list);
+	free(enm, M_IFMADDR);
+	ac->ac_multicnt--;
+	splx(s);
+	/*
+	 * Return ENETRESET to inform the driver that the list has changed
+	 * and its reception filter should be adjusted accordingly.
+	 */
+	return (ENETRESET);
+}