xnu-517.3.15.tar.gz

[apple/xnu.git] / bsd / net / if.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1980, 1986, 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.c        8.3 (Berkeley) 1/4/94
 * $FreeBSD: src/sys/net/if.c,v 1.85.2.9 2001/07/24 19:10:17 brooks Exp $
 */

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/kernel.h>
#include <sys/sockio.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>

#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/if_var.h>
#include <net/radix.h>
#include <net/route.h>
#ifdef __APPLE__
#include <net/dlil.h>
//#include <string.h>
#include <sys/domain.h>
#endif

#if defined(INET) || defined(INET6)
/*XXX*/
#include <netinet/in.h>
#include <netinet/in_var.h>
#if INET6
#include <netinet6/in6_var.h>
#include <netinet6/in6_ifattach.h>
#endif
#endif

/*
 * System initialization
 */

static int ifconf __P((u_long, caddr_t));
static void if_qflush __P((struct ifqueue *));
static void link_rtrequest __P((int, struct rtentry *, struct sockaddr *));

static struct   if_clone *if_clone_lookup(const char *, int *);
static int      if_clone_list(struct if_clonereq *);

MALLOC_DEFINE(M_IFADDR, "ifaddr", "interface address");
MALLOC_DEFINE(M_IFMADDR, "ether_multi", "link-level multicast address");

int     ifqmaxlen = IFQ_MAXLEN;
struct  ifnethead ifnet = TAILQ_HEAD_INITIALIZER(ifnet);
struct ifmultihead ifma_lostlist = LIST_HEAD_INITIALIZER(ifma_lostlist);

static int      if_cloners_count;
LIST_HEAD(, if_clone) if_cloners = LIST_HEAD_INITIALIZER(if_cloners);

#if INET6
/*
 * XXX: declare here to avoid to include many inet6 related files..
 * should be more generalized?
 */
extern void     nd6_setmtu __P((struct ifnet *));
#endif

#define M_CLONE         M_IFADDR

/*
 * Network interface utility routines.
 *
 * Routines with ifa_ifwith* names take sockaddr *'s as
 * parameters.
 */

int if_index;
struct ifaddr **ifnet_addrs;
struct ifnet **ifindex2ifnet;

#define INITIAL_IF_INDEXLIM     8

/*
 * Function: if_next_index
 * Purpose:
 *   Return the next available interface index.  
 *   Grow the ifnet_addrs[] and ifindex2ifnet[] arrays to accomodate the 
 *   added entry when necessary.
 *
 * Note:
 *   ifnet_addrs[] is indexed by (if_index - 1), whereas
 *   ifindex2ifnet[] is indexed by ifp->if_index.  That requires us to
 *   always allocate one extra element to hold ifindex2ifnet[0], which
 *   is unused.
 */
static int
if_next_index(void)
{
        static int      if_indexlim = 0;
        static int      if_list_growing = 0;
        int             new_index;

        while (if_list_growing) {
                /* wait until list is done growing */
                (void)tsleep((caddr_t)&ifnet_addrs, PZERO, "if_next_index", 0);
        }
        new_index = ++if_index;
        if (if_index > if_indexlim) {
                unsigned        n;
                int             new_if_indexlim;
                caddr_t         new_ifnet_addrs;
                caddr_t         new_ifindex2ifnet;
                caddr_t         old_ifnet_addrs;

                /* mark list as growing */
                if_list_growing = 1;

                old_ifnet_addrs = (caddr_t)ifnet_addrs;
                if (ifnet_addrs == NULL) {
                        new_if_indexlim = INITIAL_IF_INDEXLIM;
                } else {
                        new_if_indexlim = if_indexlim << 1;
                }

                /* allocate space for the larger arrays */
                n = (2 * new_if_indexlim + 1) * sizeof(caddr_t);
                new_ifnet_addrs = _MALLOC(n, M_IFADDR, M_WAITOK);
                new_ifindex2ifnet = new_ifnet_addrs 
                        + new_if_indexlim * sizeof(caddr_t);
                bzero(new_ifnet_addrs, n);
                if (ifnet_addrs != NULL) {
                        /* copy the existing data */
                        bcopy((caddr_t)ifnet_addrs, new_ifnet_addrs,
                              if_indexlim * sizeof(caddr_t));
                        bcopy((caddr_t)ifindex2ifnet,
                              new_ifindex2ifnet,
                              (if_indexlim + 1) * sizeof(caddr_t));
                }

                /* switch to the new tables and size */
                ifnet_addrs = (struct ifaddr **)new_ifnet_addrs;
                ifindex2ifnet = (struct ifnet **)new_ifindex2ifnet;
                if_indexlim = new_if_indexlim;

                /* release the old data */
                if (old_ifnet_addrs != NULL) {
                        _FREE((caddr_t)old_ifnet_addrs, M_IFADDR);
                }

                /* wake up others that might be blocked */
                if_list_growing = 0;
                wakeup((caddr_t)&ifnet_addrs);
        }
        return (new_index);

}

/*
 * Attach an interface to the
 * list of "active" interfaces.
 */
void
old_if_attach(ifp)
        struct ifnet *ifp;
{
        unsigned socksize, ifasize;
        int namelen, masklen;
        char workbuf[64];
        register struct sockaddr_dl *sdl;
        register struct ifaddr *ifa;

        if (ifp->if_snd.ifq_maxlen == 0)
            ifp->if_snd.ifq_maxlen = ifqmaxlen;

        /*
         * XXX -
         * The old code would work if the interface passed a pre-existing
         * chain of ifaddrs to this code.  We don't trust our callers to
         * properly initialize the tailq, however, so we no longer allow
         * this unlikely case.
         */
        TAILQ_INIT(&ifp->if_addrhead);
        TAILQ_INIT(&ifp->if_prefixhead);
        LIST_INIT(&ifp->if_multiaddrs);
        getmicrotime(&ifp->if_lastchange);

        if ((ifp->if_eflags & IFEF_REUSE) == 0 || ifp->if_index == 0) {
                /* allocate a new entry */
                ifp->if_index = if_next_index();
                ifindex2ifnet[ifp->if_index] = ifp;

                /*
                 * create a Link Level name for this device
                 */
                namelen = snprintf(workbuf, sizeof(workbuf),
                                   "%s%d", ifp->if_name, ifp->if_unit);
#define _offsetof(t, m) ((int)((caddr_t)&((t *)0)->m))
                masklen = _offsetof(struct sockaddr_dl, sdl_data[0]) + namelen;
                socksize = masklen + ifp->if_addrlen;
#define ROUNDUP(a) (1 + (((a) - 1) | (sizeof(long) - 1)))
                if (socksize < sizeof(*sdl))
                        socksize = sizeof(*sdl);
                socksize = ROUNDUP(socksize);
                ifasize = sizeof(*ifa) + 2 * socksize;
                ifa = (struct ifaddr *) _MALLOC(ifasize, M_IFADDR, M_WAITOK);
                if (ifa) {
                        bzero((caddr_t)ifa, ifasize);
                        sdl = (struct sockaddr_dl *)(ifa + 1);
                        sdl->sdl_len = socksize;
                        sdl->sdl_family = AF_LINK;
                        bcopy(workbuf, sdl->sdl_data, namelen);
                        sdl->sdl_nlen = namelen;
                        sdl->sdl_index = ifp->if_index;
                        sdl->sdl_type = ifp->if_type;
                        ifnet_addrs[ifp->if_index - 1] = ifa;
                        ifa->ifa_ifp = ifp;
                        ifa->ifa_rtrequest = link_rtrequest;
                        ifa->ifa_addr = (struct sockaddr *)sdl;
                        sdl = (struct sockaddr_dl *)(socksize + (caddr_t)sdl);
                        ifa->ifa_netmask = (struct sockaddr *)sdl;
                        sdl->sdl_len = masklen;
                        while (namelen != 0)
                                sdl->sdl_data[--namelen] = 0xff;
                }
        } else {
                ifa = ifnet_addrs[ifp->if_index - 1];
        }
        if (ifa != NULL) {
                TAILQ_INSERT_HEAD(&ifp->if_addrhead, ifa, ifa_link);
        }
        TAILQ_INSERT_TAIL(&ifnet, ifp, if_link);
}

/*
 * Create a clone network interface.
 */
static int
if_clone_create(char *name, int len)
{
        struct if_clone *ifc;
        char *dp;
        int wildcard, bytoff, bitoff;
        int unit;
        int err;

        ifc = if_clone_lookup(name, &unit);
        if (ifc == NULL)
                return (EINVAL);

        if (ifunit(name) != NULL)
                return (EEXIST);

        bytoff = bitoff = 0;
        wildcard = (unit < 0);
        /*
         * Find a free unit if none was given.
         */
        if (wildcard) {
                while ((bytoff < ifc->ifc_bmlen)
                    && (ifc->ifc_units[bytoff] == 0xff))
                        bytoff++;
                if (bytoff >= ifc->ifc_bmlen)
                        return (ENOSPC);
                while ((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0)
                        bitoff++;
                unit = (bytoff << 3) + bitoff;
        }

        if (unit > ifc->ifc_maxunit)
                return (ENXIO);

        err = (*ifc->ifc_create)(ifc, unit);
        if (err != 0)
                return (err);

        if (!wildcard) {
                bytoff = unit >> 3;
                bitoff = unit - (bytoff << 3);
        }

        /*
         * Allocate the unit in the bitmap.
         */
        KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) == 0,
            ("%s: bit is already set", __func__));
        ifc->ifc_units[bytoff] |= (1 << bitoff);

        /* In the wildcard case, we need to update the name. */
        if (wildcard) {
                for (dp = name; *dp != '\0'; dp++);
                if (snprintf(dp, len - (dp-name), "%d", unit) >
                    len - (dp-name) - 1) {
                        /*
                         * This can only be a programmer error and
                         * there's no straightforward way to recover if
                         * it happens.
                         */
                        panic("if_clone_create(): interface name too long");
                }

        }

        return (0);
}

/*
 * Destroy a clone network interface.
 */
int
if_clone_destroy(const char *name)
{
        struct if_clone *ifc;
        struct ifnet *ifp;
        int bytoff, bitoff;
        int unit;

        ifc = if_clone_lookup(name, &unit);
        if (ifc == NULL)
                return (EINVAL);

        if (unit < ifc->ifc_minifs)
                return (EINVAL);

        ifp = ifunit(name);
        if (ifp == NULL)
                return (ENXIO);

        if (ifc->ifc_destroy == NULL)
                return (EOPNOTSUPP);

        (*ifc->ifc_destroy)(ifp);

        /*
         * Compute offset in the bitmap and deallocate the unit.
         */
        bytoff = unit >> 3;
        bitoff = unit - (bytoff << 3);
        KASSERT((ifc->ifc_units[bytoff] & (1 << bitoff)) != 0,
            ("%s: bit is already cleared", __func__));
        ifc->ifc_units[bytoff] &= ~(1 << bitoff);
        return (0);
}

/*
 * Look up a network interface cloner.
 */

static struct if_clone *
if_clone_lookup(const char *name, int *unitp)
{
        struct if_clone *ifc;
        const char *cp;
        int i;

        for (ifc = LIST_FIRST(&if_cloners); ifc != NULL;) {
                for (cp = name, i = 0; i < ifc->ifc_namelen; i++, cp++) {
                        if (ifc->ifc_name[i] != *cp)
                                goto next_ifc;
                }
                goto found_name;
 next_ifc:
                ifc = LIST_NEXT(ifc, ifc_list);
        }

        /* No match. */
        return ((struct if_clone *)NULL);

 found_name:
        if (*cp == '\0') {
                i = -1;
        } else {
                for (i = 0; *cp != '\0'; cp++) {
                        if (*cp < '0' || *cp > '9') {
                                /* Bogus unit number. */
                                return (NULL);
                        }
                        i = (i * 10) + (*cp - '0');
                }
        }

        if (unitp != NULL)
                *unitp = i;
        return (ifc);
}

/*
 * Register a network interface cloner.
 */
void
if_clone_attach(struct if_clone *ifc)
{
        int bytoff, bitoff;
        int err;
        int len, maxclone;
        int unit;

        KASSERT(ifc->ifc_minifs - 1 <= ifc->ifc_maxunit,
            ("%s: %s requested more units then allowed (%d > %d)",
            __func__, ifc->ifc_name, ifc->ifc_minifs,
            ifc->ifc_maxunit + 1));
        /*
         * Compute bitmap size and allocate it.
         */
        maxclone = ifc->ifc_maxunit + 1;
        len = maxclone >> 3;
        if ((len << 3) < maxclone)
                len++;
        ifc->ifc_units = _MALLOC(len, M_CLONE, M_WAITOK | M_ZERO);
        bzero(ifc->ifc_units, len);
        ifc->ifc_bmlen = len;

        LIST_INSERT_HEAD(&if_cloners, ifc, ifc_list);
        if_cloners_count++;

        for (unit = 0; unit < ifc->ifc_minifs; unit++) {
                err = (*ifc->ifc_create)(ifc, unit);
                KASSERT(err == 0,
                    ("%s: failed to create required interface %s%d",
                    __func__, ifc->ifc_name, unit));

                /* Allocate the unit in the bitmap. */
                bytoff = unit >> 3;
                bitoff = unit - (bytoff << 3);
                ifc->ifc_units[bytoff] |= (1 << bitoff);
        }
}

/*
 * Unregister a network interface cloner.
 */
void
if_clone_detach(struct if_clone *ifc)
{

        LIST_REMOVE(ifc, ifc_list);
        FREE(ifc->ifc_units, M_CLONE);
        if_cloners_count--;
}

/*
 * Provide list of interface cloners to userspace.
 */
static int
if_clone_list(struct if_clonereq *ifcr)
{
        char outbuf[IFNAMSIZ], *dst;
        struct if_clone *ifc;
        int count, error = 0;

        ifcr->ifcr_total = if_cloners_count;
        if ((dst = ifcr->ifcr_buffer) == NULL) {
                /* Just asking how many there are. */
                return (0);
        }

        if (ifcr->ifcr_count < 0)
                return (EINVAL);

        count = (if_cloners_count < ifcr->ifcr_count) ?
            if_cloners_count : ifcr->ifcr_count;

        for (ifc = LIST_FIRST(&if_cloners); ifc != NULL && count != 0;
             ifc = LIST_NEXT(ifc, ifc_list), count--, dst += IFNAMSIZ) {
                strncpy(outbuf, ifc->ifc_name, IFNAMSIZ - 1);
                error = copyout(outbuf, dst, IFNAMSIZ);
                if (error)
                        break;
        }

        return (error);
}

__private_extern__ int
ifa_foraddr(addr)
        unsigned int addr;
{
        register struct ifnet *ifp;
        register struct ifaddr *ifa;
        register unsigned int addr2;
        

        for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next)
            for (ifa = ifp->if_addrhead.tqh_first; ifa;
                 ifa = ifa->ifa_link.tqe_next) {
                if (ifa->ifa_addr->sa_family != AF_INET)
                        continue;
                addr2 = IA_SIN(ifa)->sin_addr.s_addr;

                if (addr == addr2)
                        return (1);
        }
        return (0);
}

/*
 * Locate an interface based on a complete address.
 */
/*ARGSUSED*/
struct ifaddr *
ifa_ifwithaddr(addr)
        register struct sockaddr *addr;
{
        register struct ifnet *ifp;
        register struct ifaddr *ifa;

#define equal(a1, a2) \
  (bcmp((caddr_t)(a1), (caddr_t)(a2), ((struct sockaddr *)(a1))->sa_len) == 0)
        for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next)
            for (ifa = ifp->if_addrhead.tqh_first; ifa;
                 ifa = ifa->ifa_link.tqe_next) {
                if (ifa->ifa_addr->sa_family != addr->sa_family)
                        continue;
                if (equal(addr, ifa->ifa_addr))
                        return (ifa);
                if ((ifp->if_flags & IFF_BROADCAST) && ifa->ifa_broadaddr &&
                    /* IP6 doesn't have broadcast */
                    ifa->ifa_broadaddr->sa_len != 0 &&
                    equal(ifa->ifa_broadaddr, addr))
                        return (ifa);
        }
        return ((struct ifaddr *)0);
}
/*
 * Locate the point to point interface with a given destination address.
 */
/*ARGSUSED*/
struct ifaddr *
ifa_ifwithdstaddr(addr)
        register struct sockaddr *addr;
{
        register struct ifnet *ifp;
        register struct ifaddr *ifa;

        for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next)
            if (ifp->if_flags & IFF_POINTOPOINT)
                for (ifa = ifp->if_addrhead.tqh_first; ifa;
                     ifa = ifa->ifa_link.tqe_next) {
                        if (ifa->ifa_addr->sa_family != addr->sa_family)
                                continue;
                        if (ifa->ifa_dstaddr && equal(addr, ifa->ifa_dstaddr))
                                return (ifa);
        }
        return ((struct ifaddr *)0);
}

/*
 * Find an interface on a specific network.  If many, choice
 * is most specific found.
 */
struct ifaddr *
ifa_ifwithnet(addr)
        struct sockaddr *addr;
{
        register struct ifnet *ifp;
        register struct ifaddr *ifa;
        struct ifaddr *ifa_maybe = (struct ifaddr *) 0;
        u_int af = addr->sa_family;
        char *addr_data = addr->sa_data, *cplim;

        /*
         * AF_LINK addresses can be looked up directly by their index number,
         * so do that if we can.
         */
        if (af == AF_LINK) {
            register struct sockaddr_dl *sdl = (struct sockaddr_dl *)addr;
            if (sdl->sdl_index && sdl->sdl_index <= if_index)
                return (ifnet_addrs[sdl->sdl_index - 1]);
        }

        /*
         * Scan though each interface, looking for ones that have
         * addresses in this address family.
         */
        for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next) {
                for (ifa = ifp->if_addrhead.tqh_first; ifa;
                     ifa = ifa->ifa_link.tqe_next) {
                        register char *cp, *cp2, *cp3;

                        if (ifa->ifa_addr->sa_family != af)
next:                           continue;
#ifndef __APPLE__
/* This breaks tunneling application trying to install a route with
 * a specific subnet and the local address as the destination
 * It's breaks binary compatibility with previous version of MacOS X
 */
                        if (
 
#if INET6 /* XXX: for maching gif tunnel dst as routing entry gateway */
                            addr->sa_family != AF_INET6 &&
#endif
                            ifp->if_flags & IFF_POINTOPOINT) {
                                /*
                                 * This is a bit broken as it doesn't
                                 * take into account that the remote end may
                                 * be a single node in the network we are
                                 * looking for.
                                 * The trouble is that we don't know the
                                 * netmask for the remote end.
                                 */
                                if (ifa->ifa_dstaddr != 0
                                    && equal(addr, ifa->ifa_dstaddr))
                                        return (ifa);
                        } else
#endif /* __APPLE__*/
                        {
                                /*
                                 * if we have a special address handler,
                                 * then use it instead of the generic one.
                                 */
                                if (ifa->ifa_claim_addr) {
                                        if ((*ifa->ifa_claim_addr)(ifa, addr)) {
                                                return (ifa);
                                        } else {
                                                continue;
                                        }
                                }

                                /*
                                 * Scan all the bits in the ifa's address.
                                 * If a bit dissagrees with what we are
                                 * looking for, mask it with the netmask
                                 * to see if it really matters.
                                 * (A byte at a time)
                                 */
                                if (ifa->ifa_netmask == 0)
                                        continue;
                                cp = addr_data;
                                cp2 = ifa->ifa_addr->sa_data;
                                cp3 = ifa->ifa_netmask->sa_data;
                                cplim = ifa->ifa_netmask->sa_len
                                        + (char *)ifa->ifa_netmask;
                                while (cp3 < cplim)
                                        if ((*cp++ ^ *cp2++) & *cp3++)
                                                goto next; /* next address! */
                                /*
                                 * If the netmask of what we just found
                                 * is more specific than what we had before
                                 * (if we had one) then remember the new one
                                 * before continuing to search
                                 * for an even better one.
                                 */
                                if (ifa_maybe == 0 ||
                                    rn_refines((caddr_t)ifa->ifa_netmask,
                                    (caddr_t)ifa_maybe->ifa_netmask))
                                        ifa_maybe = ifa;
                        }
                }
        }
        return (ifa_maybe);
}

/*
 * Find an interface address specific to an interface best matching
 * a given address.
 */
struct ifaddr *
ifaof_ifpforaddr(addr, ifp)
        struct sockaddr *addr;
        register struct ifnet *ifp;
{
        register struct ifaddr *ifa;
        register char *cp, *cp2, *cp3;
        register char *cplim;
        struct ifaddr *ifa_maybe = 0;
        u_int af = addr->sa_family;

        if (af >= AF_MAX)
                return (0);
        for (ifa = ifp->if_addrhead.tqh_first; ifa;
             ifa = ifa->ifa_link.tqe_next) {
                if (ifa->ifa_addr->sa_family != af)
                        continue;
                if (ifa_maybe == 0)
                        ifa_maybe = ifa;
                if (ifa->ifa_netmask == 0) {
                        if (equal(addr, ifa->ifa_addr) ||
                            (ifa->ifa_dstaddr && equal(addr, ifa->ifa_dstaddr)))
                                return (ifa);
                        continue;
                }
                if (ifp->if_flags & IFF_POINTOPOINT) {
                        if (equal(addr, ifa->ifa_dstaddr))
                                return (ifa);
                } else {
                        cp = addr->sa_data;
                        cp2 = ifa->ifa_addr->sa_data;
                        cp3 = ifa->ifa_netmask->sa_data;
                        cplim = ifa->ifa_netmask->sa_len + (char *)ifa->ifa_netmask;
                        for (; cp3 < cplim; cp3++)
                                if ((*cp++ ^ *cp2++) & *cp3)
                                        break;
                        if (cp3 == cplim)
                                return (ifa);
                }
        }
        return (ifa_maybe);
}

#include <net/route.h>

/*
 * Default action when installing a route with a Link Level gateway.
 * Lookup an appropriate real ifa to point to.
 * This should be moved to /sys/net/link.c eventually.
 */
static void
link_rtrequest(cmd, rt, sa)
        int cmd;
        register struct rtentry *rt;
        struct sockaddr *sa;
{
        register struct ifaddr *ifa;
        struct sockaddr *dst;
        struct ifnet *ifp;

        if (cmd != RTM_ADD || ((ifa = rt->rt_ifa) == 0) ||
            ((ifp = ifa->ifa_ifp) == 0) || ((dst = rt_key(rt)) == 0))
                return;
        ifa = ifaof_ifpforaddr(dst, ifp);
        if (ifa) {
                rtsetifa(rt, ifa);
                if (ifa->ifa_rtrequest && ifa->ifa_rtrequest != link_rtrequest)
                        ifa->ifa_rtrequest(cmd, rt, sa);
        }
}

/*
 * Mark an interface down and notify protocols of
 * the transition.
 * NOTE: must be called at splnet or eqivalent.
 */
void
if_unroute(ifp, flag, fam)
        register struct ifnet *ifp;
        int flag, fam;
{
        register struct ifaddr *ifa;

        ifp->if_flags &= ~flag;
        getmicrotime(&ifp->if_lastchange);
        TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
                if (fam == PF_UNSPEC || (fam == ifa->ifa_addr->sa_family))
                        pfctlinput(PRC_IFDOWN, ifa->ifa_addr);
        if_qflush(&ifp->if_snd);
        rt_ifmsg(ifp);
}

/*
 * Mark an interface up and notify protocols of
 * the transition.
 * NOTE: must be called at splnet or eqivalent.
 */
void
if_route(ifp, flag, fam)
        register struct ifnet *ifp;
        int flag, fam;
{
        register struct ifaddr *ifa;

        ifp->if_flags |= flag;
        getmicrotime(&ifp->if_lastchange);
        TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
                if (fam == PF_UNSPEC || (fam == ifa->ifa_addr->sa_family))
                        pfctlinput(PRC_IFUP, ifa->ifa_addr);
        rt_ifmsg(ifp);

}

/*
 * Mark an interface down and notify protocols of
 * the transition.
 * NOTE: must be called at splnet or eqivalent.
 */
void
if_down(ifp)
        register struct ifnet *ifp;
{

        if_unroute(ifp, IFF_UP, AF_UNSPEC);
}

/*
 * Mark an interface up and notify protocols of
 * the transition.
 * NOTE: must be called at splnet or eqivalent.
 */
void
if_up(ifp)
        register struct ifnet *ifp;
{

        if_route(ifp, IFF_UP, AF_UNSPEC);
}

/*
 * Flush an interface queue.
 */
static void
if_qflush(ifq)
        register struct ifqueue *ifq;
{
        register struct mbuf *m, *n;

        n = ifq->ifq_head;
        while ((m = n) != 0) {
                n = m->m_act;
                m_freem(m);
        }
        ifq->ifq_head = 0;
        ifq->ifq_tail = 0;
        ifq->ifq_len = 0;
}

/*
 * Map interface name to
 * interface structure pointer.
 */
struct ifnet *
ifunit(const char *name)
{
        char namebuf[IFNAMSIZ + 1];
        const char *cp;
        struct ifnet *ifp;
        int unit;
        unsigned len, m;
        char c;

        len = strlen(name);
        if (len < 2 || len > IFNAMSIZ)
                return NULL;
        cp = name + len - 1;
        c = *cp;
        if (c < '0' || c > '9')
                return NULL;            /* trailing garbage */
        unit = 0;
        m = 1;
        do {
                if (cp == name)
                        return NULL;    /* no interface name */
                unit += (c - '0') * m;
                if (unit > 1000000)
                        return NULL;    /* number is unreasonable */
                m *= 10;
                c = *--cp;
        } while (c >= '0' && c <= '9');
        len = cp - name + 1;
        bcopy(name, namebuf, len);
        namebuf[len] = '\0';
        /*
         * Now search all the interfaces for this name/number
         */
        for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next) {
                if (strcmp(ifp->if_name, namebuf))
                        continue;
                if (unit == ifp->if_unit)
                        break;
        }
        return (ifp);
}


/*
 * Map interface name in a sockaddr_dl to
 * interface structure pointer.
 */
struct ifnet *
if_withname(sa)
        struct sockaddr *sa;
{
        char ifname[IFNAMSIZ+1];
        struct sockaddr_dl *sdl = (struct sockaddr_dl *)sa;

        if ( (sa->sa_family != AF_LINK) || (sdl->sdl_nlen == 0) ||
             (sdl->sdl_nlen > IFNAMSIZ) )
                return NULL;

        /*
         * ifunit wants a null-terminated name.  It may not be null-terminated
         * in the sockaddr.  We don't want to change the caller's sockaddr,
         * and there might not be room to put the trailing null anyway, so we
         * make a local copy that we know we can null terminate safely.
         */

        bcopy(sdl->sdl_data, ifname, sdl->sdl_nlen);
        ifname[sdl->sdl_nlen] = '\0';
        return ifunit(ifname);
}


/*
 * Interface ioctls.
 */
int
ifioctl(so, cmd, data, p)
        struct socket *so;
        u_long cmd;
        caddr_t data;
        struct proc *p;
{
        register struct ifnet *ifp;
        register struct ifreq *ifr;
        struct ifstat *ifs;
        int error = 0;
        short oif_flags;
        struct kev_msg        ev_msg;
        struct net_event_data ev_data;

        switch (cmd) {

        case SIOCGIFCONF:
        case OSIOCGIFCONF:
                return (ifconf(cmd, data));
        }
        ifr = (struct ifreq *)data;

        switch (cmd) {
        case SIOCIFCREATE:
        case SIOCIFDESTROY:
                error = suser(p->p_ucred, &p->p_acflag);
                if (error)
                        return (error);
                return ((cmd == SIOCIFCREATE) ?
                        if_clone_create(ifr->ifr_name, sizeof(ifr->ifr_name)) :
                        if_clone_destroy(ifr->ifr_name));
#if 0
        case SIOCIFGCLONERS:
                return (if_clone_list((struct if_clonereq *)data));
#endif 0
        }

        ifp = ifunit(ifr->ifr_name);
        if (ifp == 0)
                return (ENXIO);
        switch (cmd) {

        case SIOCGIFFLAGS:
                ifr->ifr_flags = ifp->if_flags;
                break;

        case SIOCGIFMETRIC:
                ifr->ifr_metric = ifp->if_metric;
                break;

        case SIOCGIFMTU:
                ifr->ifr_mtu = ifp->if_mtu;
                break;

        case SIOCGIFPHYS:
                ifr->ifr_phys = ifp->if_physical;
                break;

        case SIOCSIFFLAGS:
                error = suser(p->p_ucred, &p->p_acflag);
                if (error)
                        return (error);
#ifndef __APPLE__
                if (ifp->if_flags & IFF_SMART) {
                        /* Smart drivers twiddle their own routes */
                } else
#endif
                if (ifp->if_flags & IFF_UP &&
                    (ifr->ifr_flags & IFF_UP) == 0) {
                        int s = splimp();
                        if_down(ifp);
                        splx(s);
                } else if (ifr->ifr_flags & IFF_UP &&
                    (ifp->if_flags & IFF_UP) == 0) {
                        int s = splimp();
                        if_up(ifp);
                        splx(s);
                }
                ifp->if_flags = (ifp->if_flags & IFF_CANTCHANGE) |
                        (ifr->ifr_flags &~ IFF_CANTCHANGE);

                error = dlil_ioctl(so->so_proto->pr_domain->dom_family, 
                                   ifp, cmd, (caddr_t) data);

                if (error == 0) {
                         ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                         ev_msg.kev_class      = KEV_NETWORK_CLASS;
                         ev_msg.kev_subclass   = KEV_DL_SUBCLASS;

                         ev_msg.event_code = KEV_DL_SIFFLAGS;
                         strncpy(&ev_data.if_name[0], ifp->if_name, IFNAMSIZ);
                         ev_data.if_family = ifp->if_family;
                         ev_data.if_unit   = (unsigned long) ifp->if_unit;
                         ev_msg.dv[0].data_length = sizeof(struct net_event_data);
                         ev_msg.dv[0].data_ptr    = &ev_data;
                         ev_msg.dv[1].data_length = 0;
                         kev_post_msg(&ev_msg);
                }
                getmicrotime(&ifp->if_lastchange);
                break;

        case SIOCSIFMETRIC:
                error = suser(p->p_ucred, &p->p_acflag);
                if (error)
                        return (error);
                ifp->if_metric = ifr->ifr_metric;


                ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                ev_msg.kev_class      = KEV_NETWORK_CLASS;
                ev_msg.kev_subclass   = KEV_DL_SUBCLASS;
        
                ev_msg.event_code = KEV_DL_SIFMETRICS;
                strncpy(&ev_data.if_name[0], ifp->if_name, IFNAMSIZ);
                ev_data.if_family = ifp->if_family;
                ev_data.if_unit   = (unsigned long) ifp->if_unit;
                ev_msg.dv[0].data_length = sizeof(struct net_event_data);
                ev_msg.dv[0].data_ptr    = &ev_data;

                ev_msg.dv[1].data_length = 0;
                kev_post_msg(&ev_msg);

                getmicrotime(&ifp->if_lastchange);
                break;

        case SIOCSIFPHYS:
                error = suser(p->p_ucred, &p->p_acflag);
                if (error)
                        return error;

                error = dlil_ioctl(so->so_proto->pr_domain->dom_family, 
                                        ifp, cmd, (caddr_t) data);

                if (error == 0) {
                        ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                        ev_msg.kev_class      = KEV_NETWORK_CLASS;
                        ev_msg.kev_subclass   = KEV_DL_SUBCLASS;

                        ev_msg.event_code = KEV_DL_SIFPHYS;
                        strncpy(&ev_data.if_name[0], ifp->if_name, IFNAMSIZ);
                        ev_data.if_family = ifp->if_family;
                        ev_data.if_unit   = (unsigned long) ifp->if_unit;
                        ev_msg.dv[0].data_length = sizeof(struct net_event_data);
                        ev_msg.dv[0].data_ptr    = &ev_data;
                        ev_msg.dv[1].data_length = 0;
                        kev_post_msg(&ev_msg);

                        getmicrotime(&ifp->if_lastchange);
                }
                return(error);

        case SIOCSIFMTU:
        {
                u_long oldmtu = ifp->if_mtu;

                error = suser(p->p_ucred, &p->p_acflag);
                if (error)
                        return (error);
                if (ifp->if_ioctl == NULL)
                        return (EOPNOTSUPP);
                if (ifr->ifr_mtu < IF_MINMTU || ifr->ifr_mtu > IF_MAXMTU)
                        return (EINVAL);

                error = dlil_ioctl(so->so_proto->pr_domain->dom_family, 
                                   ifp, cmd, (caddr_t) data);

                if (error == 0) {
                     ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                     ev_msg.kev_class      = KEV_NETWORK_CLASS;
                     ev_msg.kev_subclass   = KEV_DL_SUBCLASS;
        
                     ev_msg.event_code = KEV_DL_SIFMTU;
                     strncpy(&ev_data.if_name[0], ifp->if_name, IFNAMSIZ);
                     ev_data.if_family = ifp->if_family;
                     ev_data.if_unit   = (unsigned long) ifp->if_unit;
                     ev_msg.dv[0].data_length = sizeof(struct net_event_data);
                     ev_msg.dv[0].data_ptr    = &ev_data;
                     ev_msg.dv[1].data_length = 0;
                     kev_post_msg(&ev_msg);

                        getmicrotime(&ifp->if_lastchange);
                        rt_ifmsg(ifp);
                }
                /*
                 * If the link MTU changed, do network layer specific procedure.
                 */
                if (ifp->if_mtu != oldmtu) {
#if INET6
                        nd6_setmtu(ifp);
#endif
                }
                return (error);
        }

        case SIOCADDMULTI:
        case SIOCDELMULTI:
                error = suser(p->p_ucred, &p->p_acflag);
                if (error)
                        return (error);

                /* Don't allow group membership on non-multicast interfaces. */
                if ((ifp->if_flags & IFF_MULTICAST) == 0)
                        return EOPNOTSUPP;

#ifndef __APPLE__
                /* Don't let users screw up protocols' entries. */
                if (ifr->ifr_addr.sa_family != AF_LINK)
                        return EINVAL;
#endif

                if (cmd == SIOCADDMULTI) {
                        struct ifmultiaddr *ifma;
                        error = if_addmulti(ifp, &ifr->ifr_addr, &ifma);
                        ev_msg.event_code = KEV_DL_ADDMULTI;
                } else {
                        error = if_delmulti(ifp, &ifr->ifr_addr);
                        ev_msg.event_code = KEV_DL_DELMULTI;
                }
                if (error == 0) {
                     ev_msg.vendor_code    = KEV_VENDOR_APPLE;
                     ev_msg.kev_class      = KEV_NETWORK_CLASS;
                     ev_msg.kev_subclass   = KEV_DL_SUBCLASS;
                     strncpy(&ev_data.if_name[0], ifp->if_name, IFNAMSIZ);
        
                     ev_data.if_family = ifp->if_family;
                     ev_data.if_unit   = (unsigned long) ifp->if_unit;
                     ev_msg.dv[0].data_length = sizeof(struct net_event_data);
                     ev_msg.dv[0].data_ptr    = &ev_data;
                     ev_msg.dv[1].data_length = 0;
                     kev_post_msg(&ev_msg);

                     getmicrotime(&ifp->if_lastchange);
                }
                return error;

        case SIOCSETVLAN:
                if (ifp->if_type != IFT_L2VLAN) {
                        return (EOPNOTSUPP);
                }
        case SIOCSIFPHYADDR:
        case SIOCDIFPHYADDR:
#ifdef INET6
        case SIOCSIFPHYADDR_IN6:
#endif
        case SIOCSLIFPHYADDR:
        case SIOCSIFMEDIA:
        case SIOCSIFGENERIC:
        case SIOCSIFLLADDR:
                error = suser(p->p_ucred, &p->p_acflag);
                if (error)
                        return (error);

                error = dlil_ioctl(so->so_proto->pr_domain->dom_family, 
                                   ifp, cmd, (caddr_t) data);

                if (error == 0)
                        getmicrotime(&ifp->if_lastchange);
                return error;

        case SIOCGIFSTATUS:
                ifs = (struct ifstat *)data;
                ifs->ascii[0] = '\0';
                
        case SIOCGIFPSRCADDR:
        case SIOCGIFPDSTADDR:
        case SIOCGLIFPHYADDR:
        case SIOCGIFMEDIA:
        case SIOCGIFGENERIC:

                return dlil_ioctl(so->so_proto->pr_domain->dom_family, 
                                   ifp, cmd, (caddr_t) data);
        case SIOCGETVLAN:
                if (ifp->if_type != IFT_L2VLAN) {
                        return (EOPNOTSUPP);
                }
                return dlil_ioctl(so->so_proto->pr_domain->dom_family, 
                                   ifp, cmd, (caddr_t) data);

        default:
                oif_flags = ifp->if_flags;
                if (so->so_proto == 0)
                        return (EOPNOTSUPP);
#if !COMPAT_43
                return ((*so->so_proto->pr_usrreqs->pru_control)(so, cmd,
                                                                 data,
                                                                 ifp, p));
#else
            {
                int ocmd = cmd;

                switch (cmd) {

                case SIOCSIFDSTADDR:
                case SIOCSIFADDR:
                case SIOCSIFBRDADDR:
                case SIOCSIFNETMASK:
#if BYTE_ORDER != BIG_ENDIAN
                        if (ifr->ifr_addr.sa_family == 0 &&
                            ifr->ifr_addr.sa_len < 16) {
                                ifr->ifr_addr.sa_family = ifr->ifr_addr.sa_len;
                                ifr->ifr_addr.sa_len = 16;
                        }
#else
                        if (ifr->ifr_addr.sa_len == 0)
                                ifr->ifr_addr.sa_len = 16;
#endif
                        break;

                case OSIOCGIFADDR:
                        cmd = SIOCGIFADDR;
                        break;

                case OSIOCGIFDSTADDR:
                        cmd = SIOCGIFDSTADDR;
                        break;

                case OSIOCGIFBRDADDR:
                        cmd = SIOCGIFBRDADDR;
                        break;

                case OSIOCGIFNETMASK:
                        cmd = SIOCGIFNETMASK;
                }
                error =  ((*so->so_proto->pr_usrreqs->pru_control)(so,
                                                                   cmd,
                                                                   data,
                                                                   ifp, p));
                switch (ocmd) {

                case OSIOCGIFADDR:
                case OSIOCGIFDSTADDR:
                case OSIOCGIFBRDADDR:
                case OSIOCGIFNETMASK:
                        *(u_short *)&ifr->ifr_addr = ifr->ifr_addr.sa_family;

                }
            }
#endif /* COMPAT_43 */

                if (error == EOPNOTSUPP)
                        error = dlil_ioctl(so->so_proto->pr_domain->dom_family,
                                                                ifp, cmd, (caddr_t) data);

                return (error);
        }
        return (0);
}

/*
 * Set/clear promiscuous mode on interface ifp based on the truth value
 * of pswitch.  The calls are reference counted so that only the first
 * "on" request actually has an effect, as does the final "off" request.
 * Results are undefined if the "off" and "on" requests are not matched.
 */
int
ifpromisc(ifp, pswitch)
        struct ifnet *ifp;
        int pswitch;
{
        struct ifreq ifr;
        int error;
        int oldflags;

        oldflags = ifp->if_flags;
        if (pswitch) {
                /*
                 * If the device is not configured up, we cannot put it in
                 * promiscuous mode.
                 */
                if ((ifp->if_flags & IFF_UP) == 0)
                        return (ENETDOWN);
                if (ifp->if_pcount++ != 0)
                        return (0);
                ifp->if_flags |= IFF_PROMISC;
                log(LOG_INFO, "%s%d: promiscuous mode enabled\n",
                    ifp->if_name, ifp->if_unit);
        } else {
                if (--ifp->if_pcount > 0)
                        return (0);
                ifp->if_flags &= ~IFF_PROMISC;
                log(LOG_INFO, "%s%d: promiscuous mode disabled\n",
                    ifp->if_name, ifp->if_unit);
        }
        ifr.ifr_flags = ifp->if_flags;
        error = dlil_ioctl(0, ifp, SIOCSIFFLAGS, (caddr_t)&ifr);
        if (error == 0)
                rt_ifmsg(ifp);
        else
                ifp->if_flags = oldflags;
        return error;
}

/*
 * Return interface configuration
 * of system.  List may be used
 * in later ioctl's (above) to get
 * other information.
 */
/*ARGSUSED*/
static int
ifconf(cmd, data)
        u_long cmd;
        caddr_t data;
{
        register struct ifconf *ifc = (struct ifconf *)data;
        register struct ifnet *ifp = ifnet.tqh_first;
        register struct ifaddr *ifa;
        struct ifreq ifr, *ifrp;
        int space = ifc->ifc_len, error = 0;

        ifrp = ifc->ifc_req;
        for (; space > sizeof (ifr) && ifp; ifp = ifp->if_link.tqe_next) {
                char workbuf[64];
                int ifnlen, addrs;

                ifnlen = snprintf(workbuf, sizeof(workbuf),
                    "%s%d", ifp->if_name, ifp->if_unit);
                if(ifnlen + 1 > sizeof ifr.ifr_name) {
                        error = ENAMETOOLONG;
                        break;
                } else {
                        strcpy(ifr.ifr_name, workbuf);
                }

                addrs = 0;
                ifa = ifp->if_addrhead.tqh_first;
                for ( ; space > sizeof (ifr) && ifa;
                    ifa = ifa->ifa_link.tqe_next) {
                        register struct sockaddr *sa = ifa->ifa_addr;
#ifndef __APPLE__
                        if (curproc->p_prison && prison_if(curproc, sa))
                                continue;
#endif
                        addrs++;
#ifdef COMPAT_43
                        if (cmd == OSIOCGIFCONF) {
                                struct osockaddr *osa =
                                         (struct osockaddr *)&ifr.ifr_addr;
                                ifr.ifr_addr = *sa;
                                osa->sa_family = sa->sa_family;
                                error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
                                                sizeof (ifr));
                                ifrp++;
                        } else
#endif
                        if (sa->sa_len <= sizeof(*sa)) {
                                ifr.ifr_addr = *sa;
                                error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
                                                sizeof (ifr));
                                ifrp++;
                        } else {
                                if (space < sizeof (ifr) + sa->sa_len -
                                            sizeof(*sa))
                                        break;
                                space -= sa->sa_len - sizeof(*sa);
                                error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
                                                sizeof (ifr.ifr_name));
                                if (error == 0)
                                    error = copyout((caddr_t)sa,
                                      (caddr_t)&ifrp->ifr_addr, sa->sa_len);
                                ifrp = (struct ifreq *)
                                        (sa->sa_len + (caddr_t)&ifrp->ifr_addr);
                        }
                        if (error)
                                break;
                        space -= sizeof (ifr);
                }
                if (error)
                        break;
                if (!addrs) {
                        bzero((caddr_t)&ifr.ifr_addr, sizeof(ifr.ifr_addr));
                        error = copyout((caddr_t)&ifr, (caddr_t)ifrp,
                            sizeof (ifr));
                        if (error)
                                break;
                        space -= sizeof (ifr);
                        ifrp++;
                }
        }
        ifc->ifc_len -= space;
        return (error);
}

/*
 * Just like if_promisc(), but for all-multicast-reception mode.
 */
int
if_allmulti(ifp, onswitch)
        struct ifnet *ifp;
        int onswitch;
{
        int error = 0;
        int s = splimp();

        if (onswitch) {
                if (ifp->if_amcount++ == 0) {
                        ifp->if_flags |= IFF_ALLMULTI;
                        error = dlil_ioctl(0, ifp, SIOCSIFFLAGS, (caddr_t) 0);
                }
        } else {
                if (ifp->if_amcount > 1) {
                        ifp->if_amcount--;
                } else {
                        ifp->if_amcount = 0;
                        ifp->if_flags &= ~IFF_ALLMULTI;
                        error = dlil_ioctl(0, ifp, SIOCSIFFLAGS, (caddr_t) 0);
                }
        }
        splx(s);

        if (error == 0)
                rt_ifmsg(ifp);
        return error;
}

/*
 * Add a multicast listenership to the interface in question.
 * The link layer provides a routine which converts
 */
int
if_addmulti(ifp, sa, retifma)
        struct ifnet *ifp;      /* interface to manipulate */
        struct sockaddr *sa;    /* address to add */
        struct ifmultiaddr **retifma;
{
        struct sockaddr *llsa = 0;
        struct sockaddr *dupsa;
        int error, s;
        struct ifmultiaddr *ifma;
        struct rslvmulti_req   rsreq;

        /*
         * If the matching multicast address already exists
         * then don't add a new one, just add a reference
         */
        for (ifma = ifp->if_multiaddrs.lh_first; ifma;
             ifma = ifma->ifma_link.le_next) {
                if (equal(sa, ifma->ifma_addr)) {
                        ifma->ifma_refcount++;
                        if (retifma)
                                *retifma = ifma;
                        return 0;
                }
        }

        /*
         * Give the link layer a chance to accept/reject it, and also
         * find out which AF_LINK address this maps to, if it isn't one
         * already.
         */
        rsreq.sa = sa;
        rsreq.llsa = &llsa;

        error = dlil_ioctl(sa->sa_family, ifp, SIOCRSLVMULTI, (caddr_t) &rsreq);
        
        /* to be similar to FreeBSD */
        if (error == EOPNOTSUPP)
                error = 0;

        if (error) 
             return error;

        MALLOC(ifma, struct ifmultiaddr *, sizeof *ifma, M_IFMADDR, M_WAITOK);
        MALLOC(dupsa, struct sockaddr *, sa->sa_len, M_IFMADDR, M_WAITOK);
        bcopy(sa, dupsa, sa->sa_len);

        ifma->ifma_addr = dupsa;
        ifma->ifma_lladdr = llsa;
        ifma->ifma_ifp = ifp;
        ifma->ifma_refcount = 1;
        ifma->ifma_protospec = 0;
        rt_newmaddrmsg(RTM_NEWMADDR, ifma);

        /*
         * Some network interfaces can scan the address list at
         * interrupt time; lock them out.
         */
        s = splimp();
        LIST_INSERT_HEAD(&ifp->if_multiaddrs, ifma, ifma_link);
        splx(s);
        if (retifma)
            *retifma = ifma;

        if (llsa != 0) {
                for (ifma = ifp->if_multiaddrs.lh_first; ifma;
                     ifma = ifma->ifma_link.le_next) {
                        if (equal(ifma->ifma_addr, llsa))
                                break;
                }
                if (ifma) {
                        ifma->ifma_refcount++;
                } else {
                        MALLOC(ifma, struct ifmultiaddr *, sizeof *ifma,
                               M_IFMADDR, M_WAITOK);
                        MALLOC(dupsa, struct sockaddr *, llsa->sa_len,
                               M_IFMADDR, M_WAITOK);
                        bcopy(llsa, dupsa, llsa->sa_len);
                        ifma->ifma_addr = dupsa;
                        ifma->ifma_lladdr = 0;
                        ifma->ifma_ifp = ifp;
                        ifma->ifma_refcount = 1;
                        s = splimp();
                        LIST_INSERT_HEAD(&ifp->if_multiaddrs, ifma, ifma_link);
                        splx(s);
                }
        }
        /*
         * We are certain we have added something, so call down to the
         * interface to let them know about it.
         */
        s = splimp();
        dlil_ioctl(0, ifp, SIOCADDMULTI, (caddr_t) 0);
        splx(s);

        return 0;
}

int
if_delmultiaddr(struct ifmultiaddr *ifma)
{
        struct sockaddr *sa;
        struct ifnet *ifp;
        
        /* Verify ifma is valid */
        {
                struct ifmultiaddr *match = NULL;
                for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next) {
                        for (match = ifp->if_multiaddrs.lh_first; match; match = match->ifma_link.le_next) {
                                if (match->ifma_ifp != ifp) {
                                        printf("if_delmultiaddr: ifma (%x) on ifp i(%s) is stale\n",
                                                        match, if_name(ifp));
                                        return (0) ; /* swallow error ? */
                                }
                                if (match == ifma)
                                        break;
                        }
                        if (match == ifma)
                                break;
                }
                if (match != ifma) {
                        for (match = ifma_lostlist.lh_first; match; match = match->ifma_link.le_next) {
                                if (match->ifma_ifp != NULL) {
                                        printf("if_delmultiaddr: item on lost list (%x) contains non-null ifp=%s\n",
                                                        match, if_name(match->ifma_ifp));
                                        return (0) ; /* swallow error ? */
                                }
                                if (match == ifma)
                                        break;
                        }
                }
                
                if (match != ifma) {
                        printf("if_delmultiaddr: ifma 0x%X is invalid\n", ifma);
                        return 0;
                }
        }
        
        if (ifma->ifma_refcount > 1) {
                ifma->ifma_refcount--;
                return 0;
        }

        sa = ifma->ifma_lladdr;

        if (sa) /* send a routing msg for network addresses only */
                rt_newmaddrmsg(RTM_DELMADDR, ifma);

        ifp = ifma->ifma_ifp;
        
        LIST_REMOVE(ifma, ifma_link);
        /*
         * Make sure the interface driver is notified
         * in the case of a link layer mcast group being left.
         */
        if (ifp && ifma->ifma_addr->sa_family == AF_LINK && sa == 0)
                dlil_ioctl(0, ifp, SIOCDELMULTI, 0);
        FREE(ifma->ifma_addr, M_IFMADDR);
        FREE(ifma, M_IFMADDR);
        if (sa == 0)
                return 0;

        /*
         * Now look for the link-layer address which corresponds to
         * this network address.  It had been squirreled away in
         * ifma->ifma_lladdr for this purpose (so we don't have
         * to call SIOCRSLVMULTI again), and we saved that
         * value in sa above.  If some nasty deleted the
         * link-layer address out from underneath us, we can deal because
         * the address we stored was is not the same as the one which was
         * in the record for the link-layer address.  (So we don't complain
         * in that case.)
         */
        if (ifp)
                ifma = ifp->if_multiaddrs.lh_first;
        else
                ifma = ifma_lostlist.lh_first;
        for (; ifma; ifma = ifma->ifma_link.le_next)
                if (equal(sa, ifma->ifma_addr))
                        break;
        
        FREE(sa, M_IFMADDR);
        if (ifma == 0) {
                return 0;
        }

        return if_delmultiaddr(ifma);
}

/*
 * Remove a reference to a multicast address on this interface.  Yell
 * if the request does not match an existing membership.
 */
int
if_delmulti(ifp, sa)
        struct ifnet *ifp;
        struct sockaddr *sa;
{
        struct ifmultiaddr *ifma;

        for (ifma = ifp->if_multiaddrs.lh_first; ifma;
             ifma = ifma->ifma_link.le_next)
                if (equal(sa, ifma->ifma_addr))
                        break;
        if (ifma == 0)
                return ENOENT;
        
        return if_delmultiaddr(ifma);
}


/*
 * We don't use if_setlladdr, our interfaces are responsible for
 * handling the SIOCSIFLLADDR ioctl.
 */
#ifndef __APPLE__
int
if_setlladdr(struct ifnet *ifp, const u_char *lladdr, int len)
{
        ...
}
#endif

struct ifmultiaddr *
ifmaof_ifpforaddr(sa, ifp)
        struct sockaddr *sa;
        struct ifnet *ifp;
{
        struct ifmultiaddr *ifma;
        
        for (ifma = ifp->if_multiaddrs.lh_first; ifma;
             ifma = ifma->ifma_link.le_next)
                if (equal(ifma->ifma_addr, sa))
                        break;

        return ifma;
}

SYSCTL_NODE(_net, PF_LINK, link, CTLFLAG_RW, 0, "Link layers");
SYSCTL_NODE(_net_link, 0, generic, CTLFLAG_RW, 0, "Generic link-management");


/*
 * Shutdown all network activity.  Used boot() when halting
 * system.
 */
int if_down_all(void)
{
        struct ifnet *ifp;
        int s;

        s = splnet();
        TAILQ_FOREACH(ifp, &ifnet, if_link)
                if_down(ifp);

        splx(s);
        return(0);              /* Sheesh */
}

/*
 * Delete Routes for a Network Interface
 * 
 * Called for each routing entry via the rnh->rnh_walktree() call above
 * to delete all route entries referencing a detaching network interface.
 *
 * Arguments:
 *      rn      pointer to node in the routing table
 *      arg     argument passed to rnh->rnh_walktree() - detaching interface
 *
 * Returns:
 *      0       successful
 *      errno   failed - reason indicated
 *
 */
static int
if_rtdel(rn, arg)
        struct radix_node       *rn;
        void                    *arg;
{
        struct rtentry  *rt = (struct rtentry *)rn;
        struct ifnet    *ifp = arg;
        int             err;

        if (rt != NULL && rt->rt_ifp == ifp) {
                
                /*
                 * Protect (sorta) against walktree recursion problems
                 * with cloned routes
                 */
                if ((rt->rt_flags & RTF_UP) == 0)
                        return (0);

                err = rtrequest(RTM_DELETE, rt_key(rt), rt->rt_gateway,
                                rt_mask(rt), rt->rt_flags,
                                (struct rtentry **) NULL);
                if (err) {
                        log(LOG_WARNING, "if_rtdel: error %d\n", err);
                }
        }

        return (0);
}

/*
 * Removes routing table reference to a given interfacei
 * for a given protocol family
 */

void if_rtproto_del(struct ifnet *ifp, int protocol)
{
        
        struct radix_node_head  *rnh;

        if ((protocol <= AF_MAX) && ((rnh = rt_tables[protocol]) != NULL) && (ifp != NULL))
                (void) rnh->rnh_walktree(rnh, if_rtdel, ifp);
}