/*
 * Copyright 1998 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that both the above copyright notice and this
 * permission notice appear in all copies, that both the above
 * copyright notice and this permission notice appear in all
 * supporting documentation, and that the name of M.I.T. not be used
 * in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  M.I.T. makes
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 * 
 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
 * SHALL M.I.T. 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.
 *
 * $FreeBSD: src/sys/net/if_vlan.c,v 1.15.2.13 2003/02/14 22:25:58 fenner Exp $
 */

/*
 * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs.
 * Might be extended some day to also handle IEEE 802.1p priority
 * tagging.  This is sort of sneaky in the implementation, since
 * we need to pretend to be enough of an Ethernet implementation
 * to make arp work.  The way we do this is by telling everyone
 * that we are an Ethernet, and then catch the packets that
 * ether_output() left on our output queue queue when it calls
 * if_start(), rewrite them for use by the real outgoing interface,
 * and ask it to send them.
 *
 *
 * Note about vlan's MP safe approach:
 *
 * - All configuration operation, e.g. config, unconfig and change flags,
 *   is serialized by netisr0; not by vlan's serializer
 *
 * - Parent interface's trunk and vlans are linked in the following
 *   fashion:
 *                     CPU0     CPU1     CPU2     CPU3
 *   +--------------+--------+--------+--------+--------+
 *   | parent ifnet |trunk[0]|trunk[1]|trunk[2]|trunk[3]|
 *   +--------------+--------+--------+--------+--------+
 *                       |        |        |        |
 *                       V        V        V        V
 *   +--------------+--------+--------+--------+--------+
 *   |   vlan ifnet |entry[0]|entry[1]|entry[2]|entry[3]|
 *   +--------------+--------+--------+--------+--------+
 *                       |        |        |        |
 *                       V        V        V        V
 *   +--------------+--------+--------+--------+--------+
 *   |   vlan ifnet |entry[0]|entry[1]|entry[2]|entry[3]|
 *   +--------------+--------+--------+--------+--------+
 *
 * - Vlan is linked/unlinked onto parent interface's trunk using following
 *   way:
 *
 *       CPU0             CPU1              CPU2              CPU3
 *
 *      netisr0 <----------------------------------------------+
 *  (config/unconfig)                                          |
 *         |                                                   |
 *         | domsg                                             | replymsg
 *         : (link/unlink)                                     |
 *         :                                                   |
 *         :   fwdmsg             fwdmsg            fwdmsg     |
 *         :-----------> netisr1 --------> netisr2 --------> netisr3
 *                    (link/unlink)     (link/unlink)     (link/unlink)
 *
 * - Parent interface's trunk is destroyed in the following lockless way:
 *
 *     old_trunk = ifp->if_vlantrunks;
 *     ifp->if_vlantrunks = NULL;
 *     netmsg_service_sync();
 *     (*)
 *     free(old_trunk);
 *
 *   Since all of the accessing of if_vlantrunks only happens in network
 *   threads (percpu netisr and ifnet threads), after netmsg_service_sync()
 *   the network threads are promised to see only NULL if_vlantrunks; we
 *   are safe to free the "to be destroyed" parent interface's trunk
 *   afterwards.
 */

#ifndef NVLAN
#include "use_vlan.h"
#endif
#include "opt_inet.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/bus.h>
#include <sys/thread2.h>

#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/ifq_var.h>
#include <net/if_clone.h>
#include <net/netmsg2.h>
#include <net/netisr2.h>

#ifdef INET
#include <netinet/in.h>
#include <netinet/if_ether.h>
#endif

#include <net/vlan/if_vlan_var.h>
#include <net/vlan/if_vlan_ether.h>

struct ifvlan;

struct vlan_mc_entry {
        struct ether_addr               mc_addr;
        SLIST_ENTRY(vlan_mc_entry)      mc_entries;
};

struct vlan_entry {
        struct ifvlan           *ifv;
        LIST_ENTRY(vlan_entry)  ifv_link;
};

struct  ifvlan {
        struct  arpcom ifv_ac;  /* make this an interface */
        struct  ifnet *ifv_p;   /* parent inteface of this vlan */
        int ifv_pflags;         /* special flags we have set on parent */
        struct  ifv_linkmib {
                int     ifvm_parent;
                uint16_t ifvm_proto; /* encapsulation ethertype */
                uint16_t ifvm_tag; /* tag to apply on packets leaving if */
        }       ifv_mib;
        SLIST_HEAD(, vlan_mc_entry) vlan_mc_listhead;
        LIST_ENTRY(ifvlan) ifv_list;
        struct vlan_entry ifv_entries[1];
};
#define ifv_if  ifv_ac.ac_if
#define ifv_tag ifv_mib.ifvm_tag

struct vlan_trunk {
        LIST_HEAD(, vlan_entry) vlan_list;
};

struct netmsg_vlan {
        struct netmsg_base base;
        struct ifvlan   *nv_ifv;
        struct ifnet    *nv_ifp_p;
        const char      *nv_parent_name;
        uint16_t        nv_vlantag;
};

#define VLANNAME        "vlan"

SYSCTL_DECL(_net_link);
SYSCTL_NODE(_net_link, IFT_L2VLAN, vlan, CTLFLAG_RW, 0, "IEEE 802.1Q VLAN");
SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0, "for consistency");

static MALLOC_DEFINE(M_VLAN, "vlan", "802.1Q Virtual LAN Interface");
static LIST_HEAD(, ifvlan) ifv_list;

static int      vlan_clone_create(struct if_clone *, int, caddr_t, caddr_t);
static int      vlan_clone_destroy(struct ifnet *);
static void     vlan_ifdetach(void *, struct ifnet *);

static void     vlan_init(void *);
static void     vlan_start(struct ifnet *, struct ifaltq_subque *);
static int      vlan_ioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
static void     vlan_input(struct mbuf *);

static int      vlan_setflags(struct ifvlan *, struct ifnet *, int);
static int      vlan_setflag(struct ifvlan *, struct ifnet *, int, int,
                             int (*)(struct ifnet *, int));
static int      vlan_config_flags(struct ifvlan *ifv);
static void     vlan_clrmulti(struct ifvlan *, struct ifnet *);
static int      vlan_setmulti(struct ifvlan *, struct ifnet *);
static int      vlan_config_multi(struct ifvlan *);
static int      vlan_config(struct ifvlan *, const char *, uint16_t);
static int      vlan_unconfig(struct ifvlan *);
static void     vlan_link(struct ifvlan *, struct ifnet *);
static void     vlan_unlink(struct ifvlan *, struct ifnet *);

static void     vlan_config_dispatch(netmsg_t);
static void     vlan_unconfig_dispatch(netmsg_t);
static void     vlan_link_dispatch(netmsg_t);
static void     vlan_unlink_dispatch(netmsg_t);
static void     vlan_multi_dispatch(netmsg_t);
static void     vlan_flags_dispatch(netmsg_t);
static void     vlan_ifdetach_dispatch(netmsg_t);

/* Special flags we should propagate to parent */
static struct {
        int flag;
        int (*func)(struct ifnet *, int);
} vlan_pflags[] = {
        { IFF_PROMISC, ifpromisc },
        { IFF_ALLMULTI, if_allmulti },
        { 0, NULL }
};

static eventhandler_tag vlan_ifdetach_cookie;
static struct if_clone vlan_cloner =
        IF_CLONE_INITIALIZER("vlan", vlan_clone_create, vlan_clone_destroy,
                             NVLAN, IF_MAXUNIT);

/*
 * Handle IFF_* flags that require certain changes on the parent:
 * if "set" is true, update parent's flags respective to our if_flags;
 * if "set" is false, forcedly clear the flags set on parent.
 */
static int
vlan_setflags(struct ifvlan *ifv, struct ifnet *ifp_p, int set)
{
        int error, i;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(&ifv->ifv_if);

        for (i = 0; vlan_pflags[i].func != NULL; i++) {
                error = vlan_setflag(ifv, ifp_p, vlan_pflags[i].flag,
                                     set, vlan_pflags[i].func);
                if (error)
                        return error;
        }
        return 0;
}

/* Handle a reference counted flag that should be set on the parent as well */
static int
vlan_setflag(struct ifvlan *ifv, struct ifnet *ifp_p, int flag, int set,
             int (*func)(struct ifnet *, int))
{
        struct ifnet *ifp = &ifv->ifv_if;
        int error, ifv_flag;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(ifp);

        ifv_flag = set ? (ifp->if_flags & flag) : 0;

        /*
         * See if recorded parent's status is different from what
         * we want it to be.  If it is, flip it.  We record parent's
         * status in ifv_pflags so that we won't clear parent's flag
         * we haven't set.  In fact, we don't clear or set parent's
         * flags directly, but get or release references to them.
         * That's why we can be sure that recorded flags still are
         * in accord with actual parent's flags.
         */
        if (ifv_flag != (ifv->ifv_pflags & flag)) {
                error = func(ifp_p, ifv_flag);
                if (error)
                        return error;
                ifv->ifv_pflags &= ~flag;
                ifv->ifv_pflags |= ifv_flag;
        }
        return 0;
}

/*
 * Program our multicast filter. What we're actually doing is
 * programming the multicast filter of the parent. This has the
 * side effect of causing the parent interface to receive multicast
 * traffic that it doesn't really want, which ends up being discarded
 * later by the upper protocol layers. Unfortunately, there's no way
 * to avoid this: there really is only one physical interface.
 */
static int
vlan_setmulti(struct ifvlan *ifv, struct ifnet *ifp_p)
{
        struct ifmultiaddr *ifma;
        struct vlan_mc_entry *mc = NULL;
        struct sockaddr_dl sdl;
        struct ifnet *ifp = &ifv->ifv_if;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(ifp);

        /*
         * First, remove any existing filter entries.
         */
        vlan_clrmulti(ifv, ifp_p);

        /*
         * Save the filter entries to be added to parent.
         *
         * TODO: need ifnet_serialize_main
         */
        ifnet_serialize_all(ifp);
        TAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;

                /* Save a copy */
                mc = kmalloc(sizeof(struct vlan_mc_entry), M_VLAN, M_WAITOK);
                bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr),
                      &mc->mc_addr, ETHER_ADDR_LEN);
                SLIST_INSERT_HEAD(&ifv->vlan_mc_listhead, mc, mc_entries);
        }
        ifnet_deserialize_all(ifp);

        /*
         * Now program new ones.
         */
        bzero(&sdl, sizeof(sdl));
        sdl.sdl_len = sizeof(sdl);
        sdl.sdl_family = AF_LINK;
        sdl.sdl_index = ifp_p->if_index;
        sdl.sdl_type = IFT_ETHER;
        sdl.sdl_alen = ETHER_ADDR_LEN;

        /*
         * Program the parent multicast filter
         */
        SLIST_FOREACH(mc, &ifv->vlan_mc_listhead, mc_entries) {
                int error;

                bcopy(&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN);
                error = if_addmulti(ifp_p, (struct sockaddr *)&sdl, NULL);
                if (error) {
                        /* XXX probably should keep going */
                        return error;
                }
        }
        return 0;
}

static void
vlan_clrmulti(struct ifvlan *ifv, struct ifnet *ifp_p)
{
        struct vlan_mc_entry *mc;
        struct sockaddr_dl sdl;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(&ifv->ifv_if);

        bzero(&sdl, sizeof(sdl));
        sdl.sdl_len = sizeof(sdl);
        sdl.sdl_family = AF_LINK;
        sdl.sdl_index = ifp_p->if_index;
        sdl.sdl_type = IFT_ETHER;
        sdl.sdl_alen = ETHER_ADDR_LEN;

        while ((mc = SLIST_FIRST(&ifv->vlan_mc_listhead)) != NULL) {
                bcopy(&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN);
                if_delmulti(ifp_p, (struct sockaddr *)&sdl); /* ignore error */

                SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries);
                kfree(mc, M_VLAN);
        }
}

static int
vlan_modevent(module_t mod, int type, void *data)
{
        switch (type) {
        case MOD_LOAD:
                LIST_INIT(&ifv_list);
                vlan_input_p = vlan_input;
                vlan_ifdetach_cookie =
                EVENTHANDLER_REGISTER(ifnet_detach_event,
                                      vlan_ifdetach, NULL,
                                      EVENTHANDLER_PRI_ANY);
                if_clone_attach(&vlan_cloner);
                break;

        case MOD_UNLOAD:
                if_clone_detach(&vlan_cloner);

                vlan_input_p = NULL;
                /*
                 * Make sure that all protocol threads see vlan_input_p change.
                 */
                netmsg_service_sync();

                EVENTHANDLER_DEREGISTER(ifnet_detach_event,
                                        vlan_ifdetach_cookie);
                while (!LIST_EMPTY(&ifv_list))
                        vlan_clone_destroy(&LIST_FIRST(&ifv_list)->ifv_if);
                break;
        }
        return 0;
}

static moduledata_t vlan_mod = {
        "if_vlan",
        vlan_modevent,
        0
};

DECLARE_MODULE(if_vlan, vlan_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);

static void
vlan_ifdetach_dispatch(netmsg_t msg)
{
        struct netmsg_vlan *vmsg = (struct netmsg_vlan *)msg;
        struct ifnet *ifp_p = vmsg->nv_ifp_p;
        struct vlan_trunk *vlantrunks, *trunk;
        struct vlan_entry *ifve;

        vlantrunks = ifp_p->if_vlantrunks;
        if (vlantrunks == NULL)
                goto reply;
        trunk = &vlantrunks[mycpuid];

        while (ifp_p->if_vlantrunks &&
               (ifve = LIST_FIRST(&trunk->vlan_list)) != NULL)
        {
                vlan_unconfig(ifve->ifv);
        }
reply:
        lwkt_replymsg(&vmsg->base.lmsg, 0);
}

static void
vlan_ifdetach(void *arg __unused, struct ifnet *ifp)
{
        struct netmsg_vlan vmsg;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(ifp);

        bzero(&vmsg, sizeof(vmsg));

        netmsg_init(&vmsg.base, NULL, &curthread->td_msgport,
                    0, vlan_ifdetach_dispatch);
        vmsg.nv_ifp_p = ifp;

        lwkt_domsg(netisr_cpuport(0), &vmsg.base.lmsg, 0);
}

static int
vlan_clone_create(struct if_clone *ifc, int unit,
                  caddr_t params __unused, caddr_t data __unused)
{
        struct ifvlan *ifv;
        struct ifnet *ifp;
        int vlan_size, i;

        vlan_size = sizeof(struct ifvlan)
                  + ((netisr_ncpus - 1) * sizeof(struct vlan_entry));
        ifv = kmalloc(vlan_size, M_VLAN, M_WAITOK | M_ZERO);
        SLIST_INIT(&ifv->vlan_mc_listhead);
        for (i = 0; i < netisr_ncpus; ++i)
                ifv->ifv_entries[i].ifv = ifv;

        crit_enter();   /* XXX not MP safe */
        LIST_INSERT_HEAD(&ifv_list, ifv, ifv_list);
        crit_exit();

        ifp = &ifv->ifv_if;
        ifp->if_softc = ifv;
        if_initname(ifp, "vlan", unit);
        /* NB: flags are not set here */
        ifp->if_linkmib = &ifv->ifv_mib;
        ifp->if_linkmiblen = sizeof ifv->ifv_mib;
        /* NB: mtu is not set here */

        ifp->if_init = vlan_init;
        ifp->if_start = vlan_start;
        ifp->if_ioctl = vlan_ioctl;
        ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
        ifq_set_ready(&ifp->if_snd);
        ether_ifattach(ifp, ifv->ifv_ac.ac_enaddr, NULL);
        /* Now undo some of the damage... */
        ifp->if_data.ifi_type = IFT_L2VLAN;
        ifp->if_data.ifi_hdrlen = EVL_ENCAPLEN;

        return (0);
}

static int
vlan_clone_destroy(struct ifnet *ifp)
{
        struct ifvlan *ifv = ifp->if_softc;

        crit_enter();   /* XXX not MP safe */
        LIST_REMOVE(ifv, ifv_list);
        crit_exit();

        vlan_unconfig(ifv);
        ether_ifdetach(ifp);

        kfree(ifv, M_VLAN);

        return 0;
}

static void
vlan_init(void *xsc)
{
        struct ifvlan *ifv = xsc;
        struct ifnet *ifp = &ifv->ifv_if;

        ASSERT_IFNET_SERIALIZED_ALL(ifp);

        if (ifv->ifv_p != NULL)
                ifp->if_flags |= IFF_RUNNING;
}

static void
vlan_start(struct ifnet *ifp, struct ifaltq_subque *ifsq)
{
        struct ifvlan *ifv = ifp->if_softc;
        struct ifnet *ifp_p = ifv->ifv_p;
        struct mbuf *m;
        lwkt_port_t p_port;

        ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
        ASSERT_ALTQ_SQ_SERIALIZED_HW(ifsq);

        if (ifp_p == NULL) {
                ifsq_purge(ifsq);
                return;
        }

        if ((ifp->if_flags & IFF_RUNNING) == 0)
                return;

        p_port = netisr_cpuport(
            ifsq_get_cpuid(ifq_get_subq_default(&ifp_p->if_snd)));
        for (;;) {
                struct netmsg_packet *nmp;

                m = ifsq_dequeue(ifsq);
                if (m == NULL)
                        break;
                BPF_MTAP(ifp, m);

                /*
                 * Do not run parent's if_start() if the parent is not up,
                 * or parent's driver will cause a system crash.
                 */
                if ((ifp_p->if_flags & (IFF_UP | IFF_RUNNING)) !=
                    (IFF_UP | IFF_RUNNING)) {
                        m_freem(m);
                        IFNET_STAT_INC(ifp, collisions, 1);
                        continue;
                }

                /*
                 * We need some way to tell the interface where the packet
                 * came from so that it knows how to find the VLAN tag to
                 * use, so we set the ether_vlantag in the mbuf packet header
                 * to our vlan tag.  We also set the M_VLANTAG flag in the
                 * mbuf to let the parent driver know that the ether_vlantag
                 * is really valid.
                 */
                m->m_pkthdr.ether_vlantag = ifv->ifv_tag;
                m->m_flags |= M_VLANTAG;

                nmp = &m->m_hdr.mh_netmsg;

                netmsg_init(&nmp->base, NULL, &netisr_apanic_rport,
                            0, vlan_start_dispatch);
                nmp->nm_packet = m;
                nmp->base.lmsg.u.ms_resultp = ifp_p;

                lwkt_sendmsg(p_port, &nmp->base.lmsg);
                IFNET_STAT_INC(ifp, opackets, 1);
        }
}

static void
vlan_input(struct mbuf *m)
{
        struct ifvlan *ifv = NULL;
        struct ifnet *rcvif;
        struct vlan_trunk *vlantrunks;
        struct vlan_entry *entry;
        int cpuid = mycpuid;

        ASSERT_NETISR_NCPUS(cpuid);

        rcvif = m->m_pkthdr.rcvif;
        KKASSERT(m->m_flags & M_VLANTAG);

        /* Make sure 'vlantrunks' is really used. */
        vlantrunks = rcvif->if_vlantrunks;
        cpu_ccfence();
        if (vlantrunks == NULL) {
                IFNET_STAT_INC(rcvif, noproto, 1);
                m_freem(m);
                return;
        }

        /*
         * Locate the associated vlan
         */
        LIST_FOREACH(entry, &vlantrunks[cpuid].vlan_list, ifv_link) {
                if (entry->ifv->ifv_tag ==
                    EVL_VLANOFTAG(m->m_pkthdr.ether_vlantag))
                {
                        ifv = entry->ifv;
                        break;
                }
        }

        /*
         * Discard packets to unknown vlans, if the vlan interface is
         * not completely initialized yet, or it is being destroyed.
         */
        if (ifv == NULL || ifv->ifv_p != rcvif) {
                IFNET_STAT_INC(rcvif, noproto, 1);
                m_freem(m);
                return;
        }

        /*
         * Clear M_VLANTAG, then hand the vlan-stripped packet to the
         * vlan(4) interface.
         */
        m->m_flags &= ~M_VLANTAG;

        ether_reinput_oncpu(&ifv->ifv_if, m, REINPUT_RUNBPF);
}

static void
vlan_link_dispatch(netmsg_t msg)
{
        struct netmsg_vlan *vmsg = (struct netmsg_vlan *)msg;
        struct ifvlan *ifv = vmsg->nv_ifv;
        struct ifnet *ifp_p = vmsg->nv_ifp_p;
        struct vlan_entry *entry;
        struct vlan_trunk *vlantrunks, *trunk;
        int cpu = mycpuid;

        vlantrunks = ifp_p->if_vlantrunks;
        KASSERT(vlantrunks != NULL,
                ("vlan trunk has not been initialized yet"));

        entry = &ifv->ifv_entries[cpu];
        trunk = &vlantrunks[cpu];

        /*
         * Critical section protects per-cpu list
         */
        crit_enter();
        LIST_INSERT_HEAD(&trunk->vlan_list, entry, ifv_link);
        crit_exit();

        netisr_forwardmsg(&vmsg->base, cpu + 1);
}

static void
vlan_link(struct ifvlan *ifv, struct ifnet *ifp_p)
{
        struct netmsg_vlan vmsg;

        /* Assert in netisr0 */
        ASSERT_IFNET_NOT_SERIALIZED_ALL(&ifv->ifv_if);

        if (ifp_p->if_vlantrunks == NULL) {
                struct vlan_trunk *vlantrunks;
                int i;

                vlantrunks = kmalloc(sizeof(*vlantrunks) * netisr_ncpus,
                                     M_VLAN,
                                     M_WAITOK | M_ZERO);
                for (i = 0; i < netisr_ncpus; ++i)
                        LIST_INIT(&vlantrunks[i].vlan_list);

                ifp_p->if_vlantrunks = vlantrunks;
        }

        bzero(&vmsg, sizeof(vmsg));

        netmsg_init(&vmsg.base, NULL, &curthread->td_msgport,
                    0, vlan_link_dispatch);
        vmsg.nv_ifv = ifv;
        vmsg.nv_ifp_p = ifp_p;

        netisr_domsg(&vmsg.base, 0);
}

static void
vlan_config_dispatch(netmsg_t msg)
{
        struct netmsg_vlan *vmsg = (struct netmsg_vlan *)msg;
        struct ifvlan *ifv;
        struct ifnet *ifp_p, *ifp;
        struct sockaddr_dl *sdl1, *sdl2;
        int error;

        /* Assert in netisr0 */

        ifp_p = ifunit_netisr(vmsg->nv_parent_name);
        if (ifp_p == NULL) {
                error = ENOENT;
                goto reply;
        }

        if (ifp_p->if_data.ifi_type != IFT_ETHER) {
                error = EPROTONOSUPPORT;
                goto reply;
        }

        ifv = vmsg->nv_ifv;
        ifp = &ifv->ifv_if;

        if (ifv->ifv_p) {
                error = EBUSY;
                goto reply;
        }

        /* Link vlan into parent's vlantrunk */
        vlan_link(ifv, ifp_p);

        ifnet_serialize_all(ifp);

        ifv->ifv_tag = vmsg->nv_vlantag;
        if (ifp_p->if_capenable & IFCAP_VLAN_MTU)
                ifp->if_mtu = ifp_p->if_mtu;
        else
                ifp->if_mtu = ifp_p->if_data.ifi_mtu - EVL_ENCAPLEN;

        /*
         * Copy only a selected subset of flags from the parent.
         * Other flags are none of our business.
         */
#define VLAN_INHERIT_FLAGS      (IFF_BROADCAST | IFF_MULTICAST | \
                                 IFF_SIMPLEX | IFF_POINTOPOINT)

        ifp->if_flags &= ~VLAN_INHERIT_FLAGS;
        ifp->if_flags |= (ifp_p->if_flags & VLAN_INHERIT_FLAGS);

#undef VLAN_INHERIT_FLAGS

        /*
         * Set up our ``Ethernet address'' to reflect the underlying
         * physical interface's.
         */
        sdl1 = IF_LLSOCKADDR(ifp);
        sdl2 = IF_LLSOCKADDR(ifp_p);
        sdl1->sdl_type = IFT_ETHER;
        sdl1->sdl_alen = ETHER_ADDR_LEN;
        bcopy(LLADDR(sdl2), LLADDR(sdl1), ETHER_ADDR_LEN);
        bcopy(LLADDR(sdl2), ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN);

        /*
         * Release vlan's serializer before reprogramming parent's
         * multicast filter to avoid possible dead lock.
         */
        ifnet_deserialize_all(ifp);

        /*
         * Configure multicast addresses that may already be
         * joined on the vlan device.
         */
        vlan_setmulti(ifv, ifp_p);

        /*
         * Set flags on the parent, if necessary.
         */
        vlan_setflags(ifv, ifp_p, 1);

        /*
         * Connect to parent after everything have been set up,
         * so input/output could know that vlan is ready to go
         */
        ifv->ifv_p = ifp_p;
        error = 0;
reply:
        lwkt_replymsg(&vmsg->base.lmsg, error);
}

static int
vlan_config(struct ifvlan *ifv, const char *parent_name, uint16_t vlantag)
{
        struct netmsg_vlan vmsg;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(&ifv->ifv_if);

        bzero(&vmsg, sizeof(vmsg));

        netmsg_init(&vmsg.base, NULL, &curthread->td_msgport,
                    0, vlan_config_dispatch);
        vmsg.nv_ifv = ifv;
        vmsg.nv_parent_name = parent_name;
        vmsg.nv_vlantag = vlantag;

        return lwkt_domsg(netisr_cpuport(0), &vmsg.base.lmsg, 0);
}

static void
vlan_unlink_dispatch(netmsg_t msg)
{
        struct netmsg_vlan *vmsg = (struct netmsg_vlan *)msg;
        struct ifvlan *ifv = vmsg->nv_ifv;
        struct vlan_entry *entry;
        int cpu = mycpuid;

        KASSERT(vmsg->nv_ifp_p->if_vlantrunks != NULL,
                ("vlan trunk has not been initialized yet"));
        entry = &ifv->ifv_entries[cpu];

        crit_enter();
        LIST_REMOVE(entry, ifv_link);
        crit_exit();

        netisr_forwardmsg(&vmsg->base, cpu + 1);
}

static void
vlan_unlink(struct ifvlan *ifv, struct ifnet *ifp_p)
{
        struct vlan_trunk *vlantrunks = ifp_p->if_vlantrunks;
        struct netmsg_vlan vmsg;

        /* Assert in netisr0 */
        ASSERT_IFNET_NOT_SERIALIZED_ALL(&ifv->ifv_if);

        KASSERT(ifp_p->if_vlantrunks != NULL,
                ("vlan trunk has not been initialized yet"));

        bzero(&vmsg, sizeof(vmsg));

        netmsg_init(&vmsg.base, NULL, &curthread->td_msgport,
                    0, vlan_unlink_dispatch);
        vmsg.nv_ifv = ifv;
        vmsg.nv_ifp_p = ifp_p;

        netisr_domsg(&vmsg.base, 0);

        crit_enter();
        if (LIST_EMPTY(&vlantrunks[mycpuid].vlan_list)) {
                ifp_p->if_vlantrunks = NULL;

                /*
                 * Make sure that all protocol threads see if_vlantrunks change.
                 */
                netmsg_service_sync();
                kfree(vlantrunks, M_VLAN);
        }
        crit_exit();
}

static void
vlan_unconfig_dispatch(netmsg_t msg)
{
        struct netmsg_vlan *vmsg = (struct netmsg_vlan *)msg;
        struct sockaddr_dl *sdl;
        struct ifvlan *ifv;
        struct ifnet *ifp_p, *ifp;
        int error;

        /* Assert in netisr0 */

        ifv = vmsg->nv_ifv;
        ifp = &ifv->ifv_if;

        if (ifp->if_flags & IFF_UP)
                if_down(ifp);

        ifnet_serialize_all(ifp);

        ifp->if_flags &= ~IFF_RUNNING;

        /*
         * Save parent ifnet pointer and disconnect from parent.
         *
         * This is done early in this function, so input/output could
         * know that we are disconnecting.
         */
        ifp_p = ifv->ifv_p;
        ifv->ifv_p = NULL;

        /*
         * Release vlan's serializer before reprogramming parent's
         * multicast filter to avoid possible dead lock.
         */
        ifnet_deserialize_all(ifp);

        if (ifp_p) {
                /*
                 * Since the interface is being unconfigured, we need to
                 * empty the list of multicast groups that we may have joined
                 * while we were alive from the parent's list.
                 */
                vlan_clrmulti(ifv, ifp_p);

                /* Clear parent's flags which was set by us. */
                vlan_setflags(ifv, ifp_p, 0);
        }

        ifnet_serialize_all(ifp);

        ifp->if_mtu = ETHERMTU;

        /* Clear our MAC address. */
        sdl = IF_LLSOCKADDR(ifp);
        sdl->sdl_type = IFT_ETHER;
        sdl->sdl_alen = ETHER_ADDR_LEN;
        bzero(LLADDR(sdl), ETHER_ADDR_LEN);
        bzero(ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN);

        ifnet_deserialize_all(ifp);

        /* Unlink vlan from parent's vlantrunk */
        if (ifp_p != NULL && ifp_p->if_vlantrunks != NULL)
                vlan_unlink(ifv, ifp_p);

        error = 0;
        lwkt_replymsg(&vmsg->base.lmsg, error);
}

static int
vlan_unconfig(struct ifvlan *ifv)
{
        struct netmsg_vlan vmsg;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(&ifv->ifv_if);

        bzero(&vmsg, sizeof(vmsg));

        netmsg_init(&vmsg.base, NULL, &curthread->td_msgport,
                    0, vlan_unconfig_dispatch);
        vmsg.nv_ifv = ifv;

        return lwkt_domsg(netisr_cpuport(0), &vmsg.base.lmsg, 0);
}

static int
vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
{
        struct ifvlan *ifv = ifp->if_softc;
        struct ifreq *ifr = (struct ifreq *)data;
        struct ifnet *ifp_p;
        struct vlanreq vlr;
        int error = 0;

        ASSERT_IFNET_SERIALIZED_ALL(ifp);

        switch (cmd) {
        case SIOCGIFMEDIA:
                ifp_p = ifv->ifv_p;
                if (ifp_p != NULL) {
                        /*
                         * Release vlan interface's serializer to void
                         * possible dead lock.
                         */
                        ifnet_deserialize_all(ifp);

                        ifnet_serialize_all(ifp_p);
                        error = ifp_p->if_ioctl(ifp_p, SIOCGIFMEDIA, data, cr);
                        ifnet_deserialize_all(ifp_p);

                        ifnet_serialize_all(ifp);

                        if (ifv->ifv_p == NULL || ifv->ifv_p != ifp_p) {
                                /*
                                 * We are disconnected from the original
                                 * parent interface or the parent interface
                                 * is changed, after vlan interface's
                                 * serializer is released.
                                 */
                                error = EINVAL;
                        }

                        /* Limit the result to the parent's current config. */
                        if (error == 0) {
                                struct ifmediareq *ifmr;

                                ifmr = (struct ifmediareq *) data;
                                if (ifmr->ifm_count >= 1 && ifmr->ifm_ulist) {
                                        ifmr->ifm_count = 1;
                                        error = copyout(&ifmr->ifm_current,
                                                ifmr->ifm_ulist, 
                                                sizeof(int));
                                }
                        }
                } else {
                        error = EINVAL;
                }
                break;

        case SIOCSIFMEDIA:
                error = EINVAL;
                break;

        case SIOCSETVLAN:
                error = copyin(ifr->ifr_data, &vlr, sizeof vlr);
                if (error)
                        break;

                ifnet_deserialize_all(ifp);
                if (vlr.vlr_parent[0] == '\0')
                        error = vlan_unconfig(ifv);
                else
                        error = vlan_config(ifv, vlr.vlr_parent, vlr.vlr_tag);
                ifnet_serialize_all(ifp);
                break;

        case SIOCGETVLAN:
                bzero(&vlr, sizeof(vlr));
                if (ifv->ifv_p) {
                        strlcpy(vlr.vlr_parent, ifv->ifv_p->if_xname,
                            sizeof(vlr.vlr_parent));
                        vlr.vlr_tag = ifv->ifv_tag;
                }
                error = copyout(&vlr, ifr->ifr_data, sizeof vlr);
                break;

        case SIOCSIFFLAGS:
                if (ifp->if_flags & IFF_UP)
                        ifp->if_init(ifp);
                else
                        ifp->if_flags &= ~IFF_RUNNING;

                /*
                 * We should propagate selected flags to the parent,
                 * e.g., promiscuous mode.
                 */
                ifnet_deserialize_all(ifp);
                error = vlan_config_flags(ifv);
                ifnet_serialize_all(ifp);
                break;

        case SIOCADDMULTI:
        case SIOCDELMULTI:
                ifnet_deserialize_all(ifp);
                error = vlan_config_multi(ifv);
                ifnet_serialize_all(ifp);
                break;

        default:
                error = ether_ioctl(ifp, cmd, data);
                break;
        }
        return error;
}

static void
vlan_multi_dispatch(netmsg_t msg)
{
        struct netmsg_vlan *vmsg = (struct netmsg_vlan *)msg;
        struct ifvlan *ifv = vmsg->nv_ifv;
        int error = 0;

        /*
         * If we don't have a parent, just remember the membership for
         * when we do.
         */
        if (ifv->ifv_p != NULL)
                error = vlan_setmulti(ifv, ifv->ifv_p);
        lwkt_replymsg(&vmsg->base.lmsg, error);
}

static int
vlan_config_multi(struct ifvlan *ifv)
{
        struct netmsg_vlan vmsg;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(&ifv->ifv_if);

        bzero(&vmsg, sizeof(vmsg));

        netmsg_init(&vmsg.base, NULL, &curthread->td_msgport,
                    0, vlan_multi_dispatch);
        vmsg.nv_ifv = ifv;

        return lwkt_domsg(netisr_cpuport(0), &vmsg.base.lmsg, 0);
}

static void
vlan_flags_dispatch(netmsg_t msg)
{
        struct netmsg_vlan *vmsg = (struct netmsg_vlan *)msg;
        struct ifvlan *ifv = vmsg->nv_ifv;
        int error = 0;

        /*
         * If we don't have a parent, just remember the flags for
         * when we do.
         */
        if (ifv->ifv_p != NULL)
                error = vlan_setflags(ifv, ifv->ifv_p, 1);
        lwkt_replymsg(&vmsg->base.lmsg, error);
}

static int
vlan_config_flags(struct ifvlan *ifv)
{
        struct netmsg_vlan vmsg;

        ASSERT_IFNET_NOT_SERIALIZED_ALL(&ifv->ifv_if);

        bzero(&vmsg, sizeof(vmsg));

        netmsg_init(&vmsg.base, NULL, &curthread->td_msgport,
                    0, vlan_flags_dispatch);
        vmsg.nv_ifv = ifv;

        return lwkt_domsg(netisr_cpuport(0), &vmsg.base.lmsg, 0);
}