mdoc.7/MANUAL STRUCTURE: add HARDWARE

[freebsd/src.git] / sys / net / if_vlan.c

/*-
 * Copyright 1998 Massachusetts Institute of Technology
 * Copyright 2012 ADARA Networks, Inc.
 * Copyright 2017 Dell EMC Isilon
 *
 * Portions of this software were developed by Robert N. M. Watson under
 * contract to ADARA Networks, Inc.
 *
 * 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.
 */

/*
 * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs.
 * 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() sends to us via if_transmit(), rewrite them for
 * use by the real outgoing interface, and ask it to send them.
 */

#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_kern_tls.h"
#include "opt_vlan.h"
#include "opt_ratelimit.h"

#include <sys/param.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/rmlock.h>
#include <sys/priv.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/sx.h>
#include <sys/taskqueue.h>

#include <net/bpf.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/if_clone.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/if_vlan_var.h>
#include <net/route.h>
#include <net/vnet.h>

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

#include <netlink/netlink.h>
#include <netlink/netlink_ctl.h>
#include <netlink/netlink_route.h>
#include <netlink/route/route_var.h>

#define VLAN_DEF_HWIDTH 4
#define VLAN_IFFLAGS    (IFF_BROADCAST | IFF_MULTICAST)

#define UP_AND_RUNNING(ifp) \
    ((ifp)->if_flags & IFF_UP && (ifp)->if_drv_flags & IFF_DRV_RUNNING)

CK_SLIST_HEAD(ifvlanhead, ifvlan);

struct ifvlantrunk {
        struct  ifnet   *parent;        /* parent interface of this trunk */
        struct  mtx     lock;
#ifdef VLAN_ARRAY
#define VLAN_ARRAY_SIZE (EVL_VLID_MASK + 1)
        struct  ifvlan  *vlans[VLAN_ARRAY_SIZE]; /* static table */
#else
        struct  ifvlanhead *hash;       /* dynamic hash-list table */
        uint16_t        hmask;
        uint16_t        hwidth;
#endif
        int             refcnt;
};

#if defined(KERN_TLS) || defined(RATELIMIT)
struct vlan_snd_tag {
        struct m_snd_tag com;
        struct m_snd_tag *tag;
};

static inline struct vlan_snd_tag *
mst_to_vst(struct m_snd_tag *mst)
{

        return (__containerof(mst, struct vlan_snd_tag, com));
}
#endif

/*
 * This macro provides a facility to iterate over every vlan on a trunk with
 * the assumption that none will be added/removed during iteration.
 */
#ifdef VLAN_ARRAY
#define VLAN_FOREACH(_ifv, _trunk) \
        size_t _i; \
        for (_i = 0; _i < VLAN_ARRAY_SIZE; _i++) \
                if (((_ifv) = (_trunk)->vlans[_i]) != NULL)
#else /* VLAN_ARRAY */
#define VLAN_FOREACH(_ifv, _trunk) \
        struct ifvlan *_next; \
        size_t _i; \
        for (_i = 0; _i < (1 << (_trunk)->hwidth); _i++) \
                CK_SLIST_FOREACH_SAFE((_ifv), &(_trunk)->hash[_i], ifv_list, _next)
#endif /* VLAN_ARRAY */

/*
 * This macro provides a facility to iterate over every vlan on a trunk while
 * also modifying the number of vlans on the trunk. The iteration continues
 * until some condition is met or there are no more vlans on the trunk.
 */
#ifdef VLAN_ARRAY
/* The VLAN_ARRAY case is simple -- just a for loop using the condition. */
#define VLAN_FOREACH_UNTIL_SAFE(_ifv, _trunk, _cond) \
        size_t _i; \
        for (_i = 0; !(_cond) && _i < VLAN_ARRAY_SIZE; _i++) \
                if (((_ifv) = (_trunk)->vlans[_i]))
#else /* VLAN_ARRAY */
/*
 * The hash table case is more complicated. We allow for the hash table to be
 * modified (i.e. vlans removed) while we are iterating over it. To allow for
 * this we must restart the iteration every time we "touch" something during
 * the iteration, since removal will resize the hash table and invalidate our
 * current position. If acting on the touched element causes the trunk to be
 * emptied, then iteration also stops.
 */
#define VLAN_FOREACH_UNTIL_SAFE(_ifv, _trunk, _cond) \
        size_t _i; \
        bool _touch = false; \
        for (_i = 0; \
            !(_cond) && _i < (1 << (_trunk)->hwidth); \
            _i = (_touch && ((_trunk) != NULL) ? 0 : _i + 1), _touch = false) \
                if (((_ifv) = CK_SLIST_FIRST(&(_trunk)->hash[_i])) != NULL && \
                    (_touch = true))
#endif /* VLAN_ARRAY */

struct vlan_mc_entry {
        struct sockaddr_dl              mc_addr;
        CK_SLIST_ENTRY(vlan_mc_entry)   mc_entries;
        struct epoch_context            mc_epoch_ctx;
};

struct ifvlan {
        struct  ifvlantrunk *ifv_trunk;
        struct  ifnet *ifv_ifp;
#define TRUNK(ifv)      ((ifv)->ifv_trunk)
#define PARENT(ifv)     (TRUNK(ifv)->parent)
        void    *ifv_cookie;
        int     ifv_pflags;     /* special flags we have set on parent */
        int     ifv_capenable;
        int     ifv_capenable2;
        int     ifv_encaplen;   /* encapsulation length */
        int     ifv_mtufudge;   /* MTU fudged by this much */
        int     ifv_mintu;      /* min transmission unit */
        struct  ether_8021q_tag ifv_qtag;
#define ifv_proto       ifv_qtag.proto
#define ifv_vid         ifv_qtag.vid
#define ifv_pcp         ifv_qtag.pcp
        struct task lladdr_task;
        CK_SLIST_HEAD(, vlan_mc_entry) vlan_mc_listhead;
#ifndef VLAN_ARRAY
        CK_SLIST_ENTRY(ifvlan) ifv_list;
#endif
};

/* 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}
};

VNET_DECLARE(int, vlan_mtag_pcp);
#define V_vlan_mtag_pcp VNET(vlan_mtag_pcp)

static const char vlanname[] = "vlan";
static MALLOC_DEFINE(M_VLAN, vlanname, "802.1Q Virtual LAN Interface");

static eventhandler_tag ifdetach_tag;
static eventhandler_tag iflladdr_tag;
static eventhandler_tag ifevent_tag;

/*
 * if_vlan uses two module-level synchronizations primitives to allow concurrent
 * modification of vlan interfaces and (mostly) allow for vlans to be destroyed
 * while they are being used for tx/rx. To accomplish this in a way that has
 * acceptable performance and cooperation with other parts of the network stack
 * there is a non-sleepable epoch(9) and an sx(9).
 *
 * The performance-sensitive paths that warrant using the epoch(9) are
 * vlan_transmit and vlan_input. Both have to check for the vlan interface's
 * existence using if_vlantrunk, and being in the network tx/rx paths the use
 * of an epoch(9) gives a measureable improvement in performance.
 *
 * The reason for having an sx(9) is mostly because there are still areas that
 * must be sleepable and also have safe concurrent access to a vlan interface.
 * Since the sx(9) exists, it is used by default in most paths unless sleeping
 * is not permitted, or if it is not clear whether sleeping is permitted.
 *
 */
#define _VLAN_SX_ID ifv_sx

static struct sx _VLAN_SX_ID;

#define VLAN_LOCKING_INIT() \
        sx_init_flags(&_VLAN_SX_ID, "vlan_sx", SX_RECURSE)

#define VLAN_LOCKING_DESTROY() \
        sx_destroy(&_VLAN_SX_ID)

#define VLAN_SLOCK()                    sx_slock(&_VLAN_SX_ID)
#define VLAN_SUNLOCK()                  sx_sunlock(&_VLAN_SX_ID)
#define VLAN_XLOCK()                    sx_xlock(&_VLAN_SX_ID)
#define VLAN_XUNLOCK()                  sx_xunlock(&_VLAN_SX_ID)
#define VLAN_SLOCK_ASSERT()             sx_assert(&_VLAN_SX_ID, SA_SLOCKED)
#define VLAN_XLOCK_ASSERT()             sx_assert(&_VLAN_SX_ID, SA_XLOCKED)
#define VLAN_SXLOCK_ASSERT()            sx_assert(&_VLAN_SX_ID, SA_LOCKED)

/*
 * We also have a per-trunk mutex that should be acquired when changing
 * its state.
 */
#define TRUNK_LOCK_INIT(trunk)          mtx_init(&(trunk)->lock, vlanname, NULL, MTX_DEF)
#define TRUNK_LOCK_DESTROY(trunk)       mtx_destroy(&(trunk)->lock)
#define TRUNK_WLOCK(trunk)              mtx_lock(&(trunk)->lock)
#define TRUNK_WUNLOCK(trunk)            mtx_unlock(&(trunk)->lock)
#define TRUNK_WLOCK_ASSERT(trunk)       mtx_assert(&(trunk)->lock, MA_OWNED);

/*
 * The VLAN_ARRAY substitutes the dynamic hash with a static array
 * with 4096 entries. In theory this can give a boost in processing,
 * however in practice it does not. Probably this is because the array
 * is too big to fit into CPU cache.
 */
#ifndef VLAN_ARRAY
static  void vlan_inithash(struct ifvlantrunk *trunk);
static  void vlan_freehash(struct ifvlantrunk *trunk);
static  int vlan_inshash(struct ifvlantrunk *trunk, struct ifvlan *ifv);
static  int vlan_remhash(struct ifvlantrunk *trunk, struct ifvlan *ifv);
static  void vlan_growhash(struct ifvlantrunk *trunk, int howmuch);
static __inline struct ifvlan * vlan_gethash(struct ifvlantrunk *trunk,
        uint16_t vid);
#endif
static  void trunk_destroy(struct ifvlantrunk *trunk);

static  void vlan_init(void *foo);
static  void vlan_input(struct ifnet *ifp, struct mbuf *m);
static  int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr);
#if defined(KERN_TLS) || defined(RATELIMIT)
static  int vlan_snd_tag_alloc(struct ifnet *,
    union if_snd_tag_alloc_params *, struct m_snd_tag **);
static  int vlan_snd_tag_modify(struct m_snd_tag *,
    union if_snd_tag_modify_params *);
static  int vlan_snd_tag_query(struct m_snd_tag *,
    union if_snd_tag_query_params *);
static  void vlan_snd_tag_free(struct m_snd_tag *);
static struct m_snd_tag *vlan_next_snd_tag(struct m_snd_tag *);
static void vlan_ratelimit_query(struct ifnet *,
    struct if_ratelimit_query_results *);
#endif
static  void vlan_qflush(struct ifnet *ifp);
static  int vlan_setflag(struct ifnet *ifp, int flag, int status,
    int (*func)(struct ifnet *, int));
static  int vlan_setflags(struct ifnet *ifp, int status);
static  int vlan_setmulti(struct ifnet *ifp);
static  int vlan_transmit(struct ifnet *ifp, struct mbuf *m);
#ifdef ALTQ
static void vlan_altq_start(struct ifnet *ifp);
static  int vlan_altq_transmit(struct ifnet *ifp, struct mbuf *m);
#endif
static  int vlan_output(struct ifnet *ifp, struct mbuf *m,
    const struct sockaddr *dst, struct route *ro);
static  void vlan_unconfig(struct ifnet *ifp);
static  void vlan_unconfig_locked(struct ifnet *ifp, int departing);
static  int vlan_config(struct ifvlan *ifv, struct ifnet *p, uint16_t tag,
        uint16_t proto);
static  void vlan_link_state(struct ifnet *ifp);
static  void vlan_capabilities(struct ifvlan *ifv);
static  void vlan_trunk_capabilities(struct ifnet *ifp);

static  struct ifnet *vlan_clone_match_ethervid(const char *, int *);
static  int vlan_clone_match(struct if_clone *, const char *);
static  int vlan_clone_create(struct if_clone *, char *, size_t,
    struct ifc_data *, struct ifnet **);
static  int vlan_clone_destroy(struct if_clone *, struct ifnet *, uint32_t);

static int vlan_clone_create_nl(struct if_clone *ifc, char *name, size_t len,
    struct ifc_data_nl *ifd);
static int vlan_clone_modify_nl(struct ifnet *ifp, struct ifc_data_nl *ifd);
static void vlan_clone_dump_nl(struct ifnet *ifp, struct nl_writer *nw);

static  void vlan_ifdetach(void *arg, struct ifnet *ifp);
static  void vlan_iflladdr(void *arg, struct ifnet *ifp);
static  void vlan_ifevent(void *arg, struct ifnet *ifp, int event);

static  void vlan_lladdr_fn(void *arg, int pending);

static struct if_clone *vlan_cloner;

#ifdef VIMAGE
VNET_DEFINE_STATIC(struct if_clone *, vlan_cloner);
#define V_vlan_cloner   VNET(vlan_cloner)
#endif

#ifdef RATELIMIT
static const struct if_snd_tag_sw vlan_snd_tag_ul_sw = {
        .snd_tag_modify = vlan_snd_tag_modify,
        .snd_tag_query = vlan_snd_tag_query,
        .snd_tag_free = vlan_snd_tag_free,
        .next_snd_tag = vlan_next_snd_tag,
        .type = IF_SND_TAG_TYPE_UNLIMITED
};

static const struct if_snd_tag_sw vlan_snd_tag_rl_sw = {
        .snd_tag_modify = vlan_snd_tag_modify,
        .snd_tag_query = vlan_snd_tag_query,
        .snd_tag_free = vlan_snd_tag_free,
        .next_snd_tag = vlan_next_snd_tag,
        .type = IF_SND_TAG_TYPE_RATE_LIMIT
};
#endif

#ifdef KERN_TLS
static const struct if_snd_tag_sw vlan_snd_tag_tls_sw = {
        .snd_tag_modify = vlan_snd_tag_modify,
        .snd_tag_query = vlan_snd_tag_query,
        .snd_tag_free = vlan_snd_tag_free,
        .next_snd_tag = vlan_next_snd_tag,
        .type = IF_SND_TAG_TYPE_TLS
};

#ifdef RATELIMIT
static const struct if_snd_tag_sw vlan_snd_tag_tls_rl_sw = {
        .snd_tag_modify = vlan_snd_tag_modify,
        .snd_tag_query = vlan_snd_tag_query,
        .snd_tag_free = vlan_snd_tag_free,
        .next_snd_tag = vlan_next_snd_tag,
        .type = IF_SND_TAG_TYPE_TLS_RATE_LIMIT
};
#endif
#endif

static void
vlan_mc_free(struct epoch_context *ctx)
{
        struct vlan_mc_entry *mc = __containerof(ctx, struct vlan_mc_entry, mc_epoch_ctx);
        free(mc, M_VLAN);
}

#ifndef VLAN_ARRAY
#define HASH(n, m)      ((((n) >> 8) ^ ((n) >> 4) ^ (n)) & (m))

static void
vlan_inithash(struct ifvlantrunk *trunk)
{
        int i, n;

        /*
         * The trunk must not be locked here since we call malloc(M_WAITOK).
         * It is OK in case this function is called before the trunk struct
         * gets hooked up and becomes visible from other threads.
         */

        KASSERT(trunk->hwidth == 0 && trunk->hash == NULL,
            ("%s: hash already initialized", __func__));

        trunk->hwidth = VLAN_DEF_HWIDTH;
        n = 1 << trunk->hwidth;
        trunk->hmask = n - 1;
        trunk->hash = malloc(sizeof(struct ifvlanhead) * n, M_VLAN, M_WAITOK);
        for (i = 0; i < n; i++)
                CK_SLIST_INIT(&trunk->hash[i]);
}

static void
vlan_freehash(struct ifvlantrunk *trunk)
{
#ifdef INVARIANTS
        int i;

        KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));
        for (i = 0; i < (1 << trunk->hwidth); i++)
                KASSERT(CK_SLIST_EMPTY(&trunk->hash[i]),
                    ("%s: hash table not empty", __func__));
#endif
        free(trunk->hash, M_VLAN);
        trunk->hash = NULL;
        trunk->hwidth = trunk->hmask = 0;
}

static int
vlan_inshash(struct ifvlantrunk *trunk, struct ifvlan *ifv)
{
        int i, b;
        struct ifvlan *ifv2;

        VLAN_XLOCK_ASSERT();
        KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));

        b = 1 << trunk->hwidth;
        i = HASH(ifv->ifv_vid, trunk->hmask);
        CK_SLIST_FOREACH(ifv2, &trunk->hash[i], ifv_list)
                if (ifv->ifv_vid == ifv2->ifv_vid)
                        return (EEXIST);

        /*
         * Grow the hash when the number of vlans exceeds half of the number of
         * hash buckets squared. This will make the average linked-list length
         * buckets/2.
         */
        if (trunk->refcnt > (b * b) / 2) {
                vlan_growhash(trunk, 1);
                i = HASH(ifv->ifv_vid, trunk->hmask);
        }
        CK_SLIST_INSERT_HEAD(&trunk->hash[i], ifv, ifv_list);
        trunk->refcnt++;

        return (0);
}

static int
vlan_remhash(struct ifvlantrunk *trunk, struct ifvlan *ifv)
{
        int i, b;
        struct ifvlan *ifv2;

        VLAN_XLOCK_ASSERT();
        KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));

        b = 1 << (trunk->hwidth - 1);
        i = HASH(ifv->ifv_vid, trunk->hmask);
        CK_SLIST_FOREACH(ifv2, &trunk->hash[i], ifv_list)
                if (ifv2 == ifv) {
                        trunk->refcnt--;
                        CK_SLIST_REMOVE(&trunk->hash[i], ifv2, ifvlan, ifv_list);
                        if (trunk->refcnt < (b * b) / 2)
                                vlan_growhash(trunk, -1);
                        return (0);
                }

        panic("%s: vlan not found\n", __func__);
        return (ENOENT); /*NOTREACHED*/
}

/*
 * Grow the hash larger or smaller if memory permits.
 */
static void
vlan_growhash(struct ifvlantrunk *trunk, int howmuch)
{
        struct ifvlan *ifv;
        struct ifvlanhead *hash2;
        int hwidth2, i, j, n, n2;

        VLAN_XLOCK_ASSERT();
        KASSERT(trunk->hwidth > 0, ("%s: hwidth not positive", __func__));

        if (howmuch == 0) {
                /* Harmless yet obvious coding error */
                printf("%s: howmuch is 0\n", __func__);
                return;
        }

        hwidth2 = trunk->hwidth + howmuch;
        n = 1 << trunk->hwidth;
        n2 = 1 << hwidth2;
        /* Do not shrink the table below the default */
        if (hwidth2 < VLAN_DEF_HWIDTH)
                return;

        hash2 = malloc(sizeof(struct ifvlanhead) * n2, M_VLAN, M_WAITOK);
        for (j = 0; j < n2; j++)
                CK_SLIST_INIT(&hash2[j]);
        for (i = 0; i < n; i++)
                while ((ifv = CK_SLIST_FIRST(&trunk->hash[i])) != NULL) {
                        CK_SLIST_REMOVE(&trunk->hash[i], ifv, ifvlan, ifv_list);
                        j = HASH(ifv->ifv_vid, n2 - 1);
                        CK_SLIST_INSERT_HEAD(&hash2[j], ifv, ifv_list);
                }
        NET_EPOCH_WAIT();
        free(trunk->hash, M_VLAN);
        trunk->hash = hash2;
        trunk->hwidth = hwidth2;
        trunk->hmask = n2 - 1;

        if (bootverbose)
                if_printf(trunk->parent,
                    "VLAN hash table resized from %d to %d buckets\n", n, n2);
}

static __inline struct ifvlan *
vlan_gethash(struct ifvlantrunk *trunk, uint16_t vid)
{
        struct ifvlan *ifv;

        NET_EPOCH_ASSERT();

        CK_SLIST_FOREACH(ifv, &trunk->hash[HASH(vid, trunk->hmask)], ifv_list)
                if (ifv->ifv_vid == vid)
                        return (ifv);
        return (NULL);
}

#if 0
/* Debugging code to view the hashtables. */
static void
vlan_dumphash(struct ifvlantrunk *trunk)
{
        int i;
        struct ifvlan *ifv;

        for (i = 0; i < (1 << trunk->hwidth); i++) {
                printf("%d: ", i);
                CK_SLIST_FOREACH(ifv, &trunk->hash[i], ifv_list)
                        printf("%s ", ifv->ifv_ifp->if_xname);
                printf("\n");
        }
}
#endif /* 0 */
#else

static __inline struct ifvlan *
vlan_gethash(struct ifvlantrunk *trunk, uint16_t vid)
{

        return trunk->vlans[vid];
}

static __inline int
vlan_inshash(struct ifvlantrunk *trunk, struct ifvlan *ifv)
{

        if (trunk->vlans[ifv->ifv_vid] != NULL)
                return EEXIST;
        trunk->vlans[ifv->ifv_vid] = ifv;
        trunk->refcnt++;

        return (0);
}

static __inline int
vlan_remhash(struct ifvlantrunk *trunk, struct ifvlan *ifv)
{

        trunk->vlans[ifv->ifv_vid] = NULL;
        trunk->refcnt--;

        return (0);
}

static __inline void
vlan_freehash(struct ifvlantrunk *trunk)
{
}

static __inline void
vlan_inithash(struct ifvlantrunk *trunk)
{
}

#endif /* !VLAN_ARRAY */

static void
trunk_destroy(struct ifvlantrunk *trunk)
{
        VLAN_XLOCK_ASSERT();

        vlan_freehash(trunk);
        trunk->parent->if_vlantrunk = NULL;
        TRUNK_LOCK_DESTROY(trunk);
        if_rele(trunk->parent);
        free(trunk, M_VLAN);
}

/*
 * 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 ifnet *ifp)
{
        struct ifnet            *ifp_p;
        struct ifmultiaddr      *ifma;
        struct ifvlan           *sc;
        struct vlan_mc_entry    *mc;
        int                     error;

        VLAN_XLOCK_ASSERT();

        /* Find the parent. */
        sc = ifp->if_softc;
        ifp_p = PARENT(sc);

        CURVNET_SET_QUIET(ifp_p->if_vnet);

        /* First, remove any existing filter entries. */
        while ((mc = CK_SLIST_FIRST(&sc->vlan_mc_listhead)) != NULL) {
                CK_SLIST_REMOVE_HEAD(&sc->vlan_mc_listhead, mc_entries);
                (void)if_delmulti(ifp_p, (struct sockaddr *)&mc->mc_addr);
                NET_EPOCH_CALL(vlan_mc_free, &mc->mc_epoch_ctx);
        }

        /* Now program new ones. */
        IF_ADDR_WLOCK(ifp);
        CK_STAILQ_FOREACH(ifma, &ifp->if_multiaddrs, ifma_link) {
                if (ifma->ifma_addr->sa_family != AF_LINK)
                        continue;
                mc = malloc(sizeof(struct vlan_mc_entry), M_VLAN, M_NOWAIT);
                if (mc == NULL) {
                        IF_ADDR_WUNLOCK(ifp);
                        CURVNET_RESTORE();
                        return (ENOMEM);
                }
                bcopy(ifma->ifma_addr, &mc->mc_addr, ifma->ifma_addr->sa_len);
                mc->mc_addr.sdl_index = ifp_p->if_index;
                CK_SLIST_INSERT_HEAD(&sc->vlan_mc_listhead, mc, mc_entries);
        }
        IF_ADDR_WUNLOCK(ifp);
        CK_SLIST_FOREACH (mc, &sc->vlan_mc_listhead, mc_entries) {
                error = if_addmulti(ifp_p, (struct sockaddr *)&mc->mc_addr,
                    NULL);
                if (error) {
                        CURVNET_RESTORE();
                        return (error);
                }
        }

        CURVNET_RESTORE();
        return (0);
}

/*
 * A handler for interface ifnet events.
 */
static void
vlan_ifevent(void *arg __unused, struct ifnet *ifp, int event)
{
        struct epoch_tracker et;
        struct ifvlan *ifv;
        struct ifvlantrunk *trunk;

        if (event != IFNET_EVENT_UPDATE_BAUDRATE)
                return;

        NET_EPOCH_ENTER(et);
        trunk = ifp->if_vlantrunk;
        if (trunk == NULL) {
                NET_EPOCH_EXIT(et);
                return;
        }

        TRUNK_WLOCK(trunk);
        VLAN_FOREACH(ifv, trunk) {
                ifv->ifv_ifp->if_baudrate = ifp->if_baudrate;
        }
        TRUNK_WUNLOCK(trunk);
        NET_EPOCH_EXIT(et);
}

/*
 * A handler for parent interface link layer address changes.
 * If the parent interface link layer address is changed we
 * should also change it on all children vlans.
 */
static void
vlan_iflladdr(void *arg __unused, struct ifnet *ifp)
{
        struct epoch_tracker et;
        struct ifvlan *ifv;
        struct ifnet *ifv_ifp;
        struct ifvlantrunk *trunk;
        struct sockaddr_dl *sdl;

        /* Need the epoch since this is run on taskqueue_swi. */
        NET_EPOCH_ENTER(et);
        trunk = ifp->if_vlantrunk;
        if (trunk == NULL) {
                NET_EPOCH_EXIT(et);
                return;
        }

        /*
         * OK, it's a trunk.  Loop over and change all vlan's lladdrs on it.
         * We need an exclusive lock here to prevent concurrent SIOCSIFLLADDR
         * ioctl calls on the parent garbling the lladdr of the child vlan.
         */
        TRUNK_WLOCK(trunk);
        VLAN_FOREACH(ifv, trunk) {
                /*
                 * Copy new new lladdr into the ifv_ifp, enqueue a task
                 * to actually call if_setlladdr. if_setlladdr needs to
                 * be deferred to a taskqueue because it will call into
                 * the if_vlan ioctl path and try to acquire the global
                 * lock.
                 */
                ifv_ifp = ifv->ifv_ifp;
                bcopy(IF_LLADDR(ifp), IF_LLADDR(ifv_ifp),
                    ifp->if_addrlen);
                sdl = (struct sockaddr_dl *)ifv_ifp->if_addr->ifa_addr;
                sdl->sdl_alen = ifp->if_addrlen;
                taskqueue_enqueue(taskqueue_thread, &ifv->lladdr_task);
        }
        TRUNK_WUNLOCK(trunk);
        NET_EPOCH_EXIT(et);
}

/*
 * A handler for network interface departure events.
 * Track departure of trunks here so that we don't access invalid
 * pointers or whatever if a trunk is ripped from under us, e.g.,
 * by ejecting its hot-plug card.  However, if an ifnet is simply
 * being renamed, then there's no need to tear down the state.
 */
static void
vlan_ifdetach(void *arg __unused, struct ifnet *ifp)
{
        struct ifvlan *ifv;
        struct ifvlantrunk *trunk;

        /* If the ifnet is just being renamed, don't do anything. */
        if (ifp->if_flags & IFF_RENAMING)
                return;
        VLAN_XLOCK();
        trunk = ifp->if_vlantrunk;
        if (trunk == NULL) {
                VLAN_XUNLOCK();
                return;
        }

        /*
         * OK, it's a trunk.  Loop over and detach all vlan's on it.
         * Check trunk pointer after each vlan_unconfig() as it will
         * free it and set to NULL after the last vlan was detached.
         */
        VLAN_FOREACH_UNTIL_SAFE(ifv, ifp->if_vlantrunk,
            ifp->if_vlantrunk == NULL)
                vlan_unconfig_locked(ifv->ifv_ifp, 1);

        /* Trunk should have been destroyed in vlan_unconfig(). */
        KASSERT(ifp->if_vlantrunk == NULL, ("%s: purge failed", __func__));
        VLAN_XUNLOCK();
}

/*
 * Return the trunk device for a virtual interface.
 */
static struct ifnet  *
vlan_trunkdev(struct ifnet *ifp)
{
        struct ifvlan *ifv;

        NET_EPOCH_ASSERT();

        if (ifp->if_type != IFT_L2VLAN)
                return (NULL);

        ifv = ifp->if_softc;
        ifp = NULL;
        if (ifv->ifv_trunk)
                ifp = PARENT(ifv);
        return (ifp);
}

/*
 * Return the 12-bit VLAN VID for this interface, for use by external
 * components such as Infiniband.
 *
 * XXXRW: Note that the function name here is historical; it should be named
 * vlan_vid().
 */
static int
vlan_tag(struct ifnet *ifp, uint16_t *vidp)
{
        struct ifvlan *ifv;

        if (ifp->if_type != IFT_L2VLAN)
                return (EINVAL);
        ifv = ifp->if_softc;
        *vidp = ifv->ifv_vid;
        return (0);
}

static int
vlan_pcp(struct ifnet *ifp, uint16_t *pcpp)
{
        struct ifvlan *ifv;

        if (ifp->if_type != IFT_L2VLAN)
                return (EINVAL);
        ifv = ifp->if_softc;
        *pcpp = ifv->ifv_pcp;
        return (0);
}

/*
 * Return a driver specific cookie for this interface.  Synchronization
 * with setcookie must be provided by the driver.
 */
static void *
vlan_cookie(struct ifnet *ifp)
{
        struct ifvlan *ifv;

        if (ifp->if_type != IFT_L2VLAN)
                return (NULL);
        ifv = ifp->if_softc;
        return (ifv->ifv_cookie);
}

/*
 * Store a cookie in our softc that drivers can use to store driver
 * private per-instance data in.
 */
static int
vlan_setcookie(struct ifnet *ifp, void *cookie)
{
        struct ifvlan *ifv;

        if (ifp->if_type != IFT_L2VLAN)
                return (EINVAL);
        ifv = ifp->if_softc;
        ifv->ifv_cookie = cookie;
        return (0);
}

/*
 * Return the vlan device present at the specific VID.
 */
static struct ifnet *
vlan_devat(struct ifnet *ifp, uint16_t vid)
{
        struct ifvlantrunk *trunk;
        struct ifvlan *ifv;

        NET_EPOCH_ASSERT();

        trunk = ifp->if_vlantrunk;
        if (trunk == NULL)
                return (NULL);
        ifp = NULL;
        ifv = vlan_gethash(trunk, vid);
        if (ifv)
                ifp = ifv->ifv_ifp;
        return (ifp);
}

/*
 * VLAN support can be loaded as a module.  The only place in the
 * system that's intimately aware of this is ether_input.  We hook
 * into this code through vlan_input_p which is defined there and
 * set here.  No one else in the system should be aware of this so
 * we use an explicit reference here.
 */
extern  void (*vlan_input_p)(struct ifnet *, struct mbuf *);

/* For if_link_state_change() eyes only... */
extern  void (*vlan_link_state_p)(struct ifnet *);

static struct if_clone_addreq_v2 vlan_addreq = {
        .version = 2,
        .match_f = vlan_clone_match,
        .create_f = vlan_clone_create,
        .destroy_f = vlan_clone_destroy,
        .create_nl_f = vlan_clone_create_nl,
        .modify_nl_f = vlan_clone_modify_nl,
        .dump_nl_f = vlan_clone_dump_nl,
};

static int
vlan_modevent(module_t mod, int type, void *data)
{

        switch (type) {
        case MOD_LOAD:
                ifdetach_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
                    vlan_ifdetach, NULL, EVENTHANDLER_PRI_ANY);
                if (ifdetach_tag == NULL)
                        return (ENOMEM);
                iflladdr_tag = EVENTHANDLER_REGISTER(iflladdr_event,
                    vlan_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
                if (iflladdr_tag == NULL)
                        return (ENOMEM);
                ifevent_tag = EVENTHANDLER_REGISTER(ifnet_event,
                    vlan_ifevent, NULL, EVENTHANDLER_PRI_ANY);
                if (ifevent_tag == NULL)
                        return (ENOMEM);
                VLAN_LOCKING_INIT();
                vlan_input_p = vlan_input;
                vlan_link_state_p = vlan_link_state;
                vlan_trunk_cap_p = vlan_trunk_capabilities;
                vlan_trunkdev_p = vlan_trunkdev;
                vlan_cookie_p = vlan_cookie;
                vlan_setcookie_p = vlan_setcookie;
                vlan_tag_p = vlan_tag;
                vlan_pcp_p = vlan_pcp;
                vlan_devat_p = vlan_devat;
#ifndef VIMAGE
                vlan_cloner = ifc_attach_cloner(vlanname, (struct if_clone_addreq *)&vlan_addreq);
#endif
                if (bootverbose)
                        printf("vlan: initialized, using "
#ifdef VLAN_ARRAY
                               "full-size arrays"
#else
                               "hash tables with chaining"
#endif

                               "\n");
                break;
        case MOD_UNLOAD:
#ifndef VIMAGE
                ifc_detach_cloner(vlan_cloner);
#endif
                EVENTHANDLER_DEREGISTER(ifnet_departure_event, ifdetach_tag);
                EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_tag);
                EVENTHANDLER_DEREGISTER(ifnet_event, ifevent_tag);
                vlan_input_p = NULL;
                vlan_link_state_p = NULL;
                vlan_trunk_cap_p = NULL;
                vlan_trunkdev_p = NULL;
                vlan_tag_p = NULL;
                vlan_cookie_p = NULL;
                vlan_setcookie_p = NULL;
                vlan_devat_p = NULL;
                VLAN_LOCKING_DESTROY();
                if (bootverbose)
                        printf("vlan: unloaded\n");
                break;
        default:
                return (EOPNOTSUPP);
        }
        return (0);
}

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

DECLARE_MODULE(if_vlan, vlan_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
MODULE_VERSION(if_vlan, 3);

#ifdef VIMAGE
static void
vnet_vlan_init(const void *unused __unused)
{
        vlan_cloner = ifc_attach_cloner(vlanname, (struct if_clone_addreq *)&vlan_addreq);
        V_vlan_cloner = vlan_cloner;
}
VNET_SYSINIT(vnet_vlan_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY,
    vnet_vlan_init, NULL);

static void
vnet_vlan_uninit(const void *unused __unused)
{

        ifc_detach_cloner(V_vlan_cloner);
}
VNET_SYSUNINIT(vnet_vlan_uninit, SI_SUB_INIT_IF, SI_ORDER_ANY,
    vnet_vlan_uninit, NULL);
#endif

/*
 * Check for <etherif>.<vlan>[.<vlan> ...] style interface names.
 */
static struct ifnet *
vlan_clone_match_ethervid(const char *name, int *vidp)
{
        char ifname[IFNAMSIZ];
        char *cp;
        struct ifnet *ifp;
        int vid;

        strlcpy(ifname, name, IFNAMSIZ);
        if ((cp = strrchr(ifname, '.')) == NULL)
                return (NULL);
        *cp = '\0';
        if ((ifp = ifunit_ref(ifname)) == NULL)
                return (NULL);
        /* Parse VID. */
        if (*++cp == '\0') {
                if_rele(ifp);
                return (NULL);
        }
        vid = 0;
        for(; *cp >= '0' && *cp <= '9'; cp++)
                vid = (vid * 10) + (*cp - '0');
        if (*cp != '\0') {
                if_rele(ifp);
                return (NULL);
        }
        if (vidp != NULL)
                *vidp = vid;

        return (ifp);
}

static int
vlan_clone_match(struct if_clone *ifc, const char *name)
{
        struct ifnet *ifp;
        const char *cp;

        ifp = vlan_clone_match_ethervid(name, NULL);
        if (ifp != NULL) {
                if_rele(ifp);
                return (1);
        }

        if (strncmp(vlanname, name, strlen(vlanname)) != 0)
                return (0);
        for (cp = name + 4; *cp != '\0'; cp++) {
                if (*cp < '0' || *cp > '9')
                        return (0);
        }

        return (1);
}

static int
vlan_clone_create(struct if_clone *ifc, char *name, size_t len,
    struct ifc_data *ifd, struct ifnet **ifpp)
{
        char *dp;
        bool wildcard = false;
        bool subinterface = false;
        int unit;
        int error;
        int vid = 0;
        uint16_t proto = ETHERTYPE_VLAN;
        struct ifvlan *ifv;
        struct ifnet *ifp;
        struct ifnet *p = NULL;
        struct ifaddr *ifa;
        struct sockaddr_dl *sdl;
        struct vlanreq vlr;
        static const u_char eaddr[ETHER_ADDR_LEN];      /* 00:00:00:00:00:00 */


        /*
         * There are three ways to specify the cloned device:
         * o pass a parameter block with the clone request.
         * o specify parameters in the text of the clone device name
         * o specify no parameters and get an unattached device that
         *   must be configured separately.
         * The first technique is preferred; the latter two are supported
         * for backwards compatibility.
         *
         * XXXRW: Note historic use of the word "tag" here.  New ioctls may be
         * called for.
         */

        if (ifd->params != NULL) {
                error = ifc_copyin(ifd, &vlr, sizeof(vlr));
                if (error)
                        return error;
                vid = vlr.vlr_tag;
                proto = vlr.vlr_proto;
                if (proto == 0)
                        proto = ETHERTYPE_VLAN;
                p = ifunit_ref(vlr.vlr_parent);
                if (p == NULL)
                        return (ENXIO);
        }

        if ((error = ifc_name2unit(name, &unit)) == 0) {

                /*
                 * vlanX interface. Set wildcard to true if the unit number
                 * is not fixed (-1)
                 */
                wildcard = (unit < 0);
        } else {
                struct ifnet *p_tmp = vlan_clone_match_ethervid(name, &vid);
                if (p_tmp != NULL) {
                        error = 0;
                        subinterface = true;
                        unit = IF_DUNIT_NONE;
                        wildcard = false;
                        if (p != NULL) {
                                if_rele(p_tmp);
                                if (p != p_tmp)
                                        error = EINVAL;
                        } else
                                p = p_tmp;
                } else
                        error = ENXIO;
        }

        if (error != 0) {
                if (p != NULL)
                        if_rele(p);
                return (error);
        }

        if (!subinterface) {
                /* vlanX interface, mark X as busy or allocate new unit # */
                error = ifc_alloc_unit(ifc, &unit);
                if (error != 0) {
                        if (p != NULL)
                                if_rele(p);
                        return (error);
                }
        }

        /* 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) {
                        panic("%s: interface name too long", __func__);
                }
        }

        ifv = malloc(sizeof(struct ifvlan), M_VLAN, M_WAITOK | M_ZERO);
        ifp = ifv->ifv_ifp = if_alloc(IFT_ETHER);
        CK_SLIST_INIT(&ifv->vlan_mc_listhead);
        ifp->if_softc = ifv;
        /*
         * Set the name manually rather than using if_initname because
         * we don't conform to the default naming convention for interfaces.
         */
        strlcpy(ifp->if_xname, name, IFNAMSIZ);
        ifp->if_dname = vlanname;
        ifp->if_dunit = unit;

        ifp->if_init = vlan_init;
#ifdef ALTQ
        ifp->if_start = vlan_altq_start;
        ifp->if_transmit = vlan_altq_transmit;
        IFQ_SET_MAXLEN(&ifp->if_snd, ifqmaxlen);
        ifp->if_snd.ifq_drv_maxlen = 0;
        IFQ_SET_READY(&ifp->if_snd);
#else
        ifp->if_transmit = vlan_transmit;
#endif
        ifp->if_qflush = vlan_qflush;
        ifp->if_ioctl = vlan_ioctl;
#if defined(KERN_TLS) || defined(RATELIMIT)
        ifp->if_snd_tag_alloc = vlan_snd_tag_alloc;
        ifp->if_ratelimit_query = vlan_ratelimit_query;
#endif
        ifp->if_flags = VLAN_IFFLAGS;
        ether_ifattach(ifp, eaddr);
        /* Now undo some of the damage... */
        ifp->if_baudrate = 0;
        ifp->if_type = IFT_L2VLAN;
        ifp->if_hdrlen = ETHER_VLAN_ENCAP_LEN;
        ifa = ifp->if_addr;
        sdl = (struct sockaddr_dl *)ifa->ifa_addr;
        sdl->sdl_type = IFT_L2VLAN;

        if (p != NULL) {
                error = vlan_config(ifv, p, vid, proto);
                if_rele(p);
                if (error != 0) {
                        /*
                         * Since we've partially failed, we need to back
                         * out all the way, otherwise userland could get
                         * confused.  Thus, we destroy the interface.
                         */
                        ether_ifdetach(ifp);
                        vlan_unconfig(ifp);
                        if_free(ifp);
                        if (!subinterface)
                                ifc_free_unit(ifc, unit);
                        free(ifv, M_VLAN);

                        return (error);
                }
        }
        *ifpp = ifp;

        return (0);
}

/*
 *
 * Parsers of IFLA_INFO_DATA inside IFLA_LINKINFO of RTM_NEWLINK
 *    {{nla_len=8, nla_type=IFLA_LINK}, 2},
 *    {{nla_len=12, nla_type=IFLA_IFNAME}, "xvlan22"},
 *    {{nla_len=24, nla_type=IFLA_LINKINFO},
 *     [
 *      {{nla_len=8, nla_type=IFLA_INFO_KIND}, "vlan"...},
 *      {{nla_len=12, nla_type=IFLA_INFO_DATA}, "\x06\x00\x01\x00\x16\x00\x00\x00"}]}
 */

struct nl_parsed_vlan {
        uint16_t vlan_id;
        uint16_t vlan_proto;
        struct ifla_vlan_flags vlan_flags;
};

#define _OUT(_field)    offsetof(struct nl_parsed_vlan, _field)
static const struct nlattr_parser nla_p_vlan[] = {
        { .type = IFLA_VLAN_ID, .off = _OUT(vlan_id), .cb = nlattr_get_uint16 },
        { .type = IFLA_VLAN_FLAGS, .off = _OUT(vlan_flags), .cb = nlattr_get_nla },
        { .type = IFLA_VLAN_PROTOCOL, .off = _OUT(vlan_proto), .cb = nlattr_get_uint16 },
};
#undef _OUT
NL_DECLARE_ATTR_PARSER(vlan_parser, nla_p_vlan);

static int
vlan_clone_create_nl(struct if_clone *ifc, char *name, size_t len,
    struct ifc_data_nl *ifd)
{
        struct epoch_tracker et;
        struct ifnet *ifp_parent;
        struct nl_pstate *npt = ifd->npt;
        struct nl_parsed_link *lattrs = ifd->lattrs;
        int error;

        /*
         * lattrs.ifla_ifname is the new interface name
         * lattrs.ifi_index contains parent interface index
         * lattrs.ifla_idata contains un-parsed vlan data
         */
        struct nl_parsed_vlan attrs = {
                .vlan_id = 0xFEFE,
                .vlan_proto = ETHERTYPE_VLAN
        };

        if (lattrs->ifla_idata == NULL) {
                nlmsg_report_err_msg(npt, "vlan id is required, guessing not supported");
                return (ENOTSUP);
        }

        error = nl_parse_nested(lattrs->ifla_idata, &vlan_parser, npt, &attrs);
        if (error != 0)
                return (error);
        if (attrs.vlan_id > 4095) {
                nlmsg_report_err_msg(npt, "Invalid VID: %d", attrs.vlan_id);
                return (EINVAL);
        }
        if (attrs.vlan_proto != ETHERTYPE_VLAN && attrs.vlan_proto != ETHERTYPE_QINQ) {
                nlmsg_report_err_msg(npt, "Unsupported ethertype: 0x%04X", attrs.vlan_proto);
                return (ENOTSUP);
        }

        struct vlanreq params = {
                .vlr_tag = attrs.vlan_id,
                .vlr_proto = attrs.vlan_proto,
        };
        struct ifc_data ifd_new = { .flags = IFC_F_SYSSPACE, .unit = ifd->unit, .params = &params };

        NET_EPOCH_ENTER(et);
        ifp_parent = ifnet_byindex(lattrs->ifi_index);
        if (ifp_parent != NULL)
                strlcpy(params.vlr_parent, if_name(ifp_parent), sizeof(params.vlr_parent));
        NET_EPOCH_EXIT(et);

        if (ifp_parent == NULL) {
                nlmsg_report_err_msg(npt, "unable to find parent interface %u", lattrs->ifi_index);
                return (ENOENT);
        }

        error = vlan_clone_create(ifc, name, len, &ifd_new, &ifd->ifp);

        return (error);
}

static int
vlan_clone_modify_nl(struct ifnet *ifp, struct ifc_data_nl *ifd)
{
        struct nl_parsed_link *lattrs = ifd->lattrs;

        if ((lattrs->ifla_idata != NULL) && ((ifd->flags & IFC_F_CREATE) == 0)) {
                struct epoch_tracker et;
                struct nl_parsed_vlan attrs = {
                        .vlan_proto = ETHERTYPE_VLAN,
                };
                int error;

                error = nl_parse_nested(lattrs->ifla_idata, &vlan_parser, ifd->npt, &attrs);
                if (error != 0)
                        return (error);

                NET_EPOCH_ENTER(et);
                struct ifnet *ifp_parent = ifnet_byindex_ref(lattrs->ifla_link);
                NET_EPOCH_EXIT(et);

                if (ifp_parent == NULL) {
                        nlmsg_report_err_msg(ifd->npt, "unable to find parent interface %u",
                            lattrs->ifla_link);
                        return (ENOENT);
                }

                struct ifvlan *ifv = ifp->if_softc;
                error = vlan_config(ifv, ifp_parent, attrs.vlan_id, attrs.vlan_proto);

                if_rele(ifp_parent);
                if (error != 0)
                        return (error);
        }

        return (nl_modify_ifp_generic(ifp, ifd->lattrs, ifd->bm, ifd->npt));
}

/*
 *    {{nla_len=24, nla_type=IFLA_LINKINFO},
 *     [
 *      {{nla_len=8, nla_type=IFLA_INFO_KIND}, "vlan"...},
 *      {{nla_len=12, nla_type=IFLA_INFO_DATA}, "\x06\x00\x01\x00\x16\x00\x00\x00"}]}
 */
static void
vlan_clone_dump_nl(struct ifnet *ifp, struct nl_writer *nw)
{
        uint32_t parent_index = 0;
        uint16_t vlan_id = 0;
        uint16_t vlan_proto = 0;

        VLAN_SLOCK();
        struct ifvlan *ifv = ifp->if_softc;
        if (TRUNK(ifv) != NULL)
                parent_index = PARENT(ifv)->if_index;
        vlan_id = ifv->ifv_vid;
        vlan_proto = ifv->ifv_proto;
        VLAN_SUNLOCK();

        if (parent_index != 0)
                nlattr_add_u32(nw, IFLA_LINK, parent_index);

        int off = nlattr_add_nested(nw, IFLA_LINKINFO);
        if (off != 0) {
                nlattr_add_string(nw, IFLA_INFO_KIND, "vlan");
                int off2 = nlattr_add_nested(nw, IFLA_INFO_DATA);
                if (off2 != 0) {
                        nlattr_add_u16(nw, IFLA_VLAN_ID, vlan_id);
                        nlattr_add_u16(nw, IFLA_VLAN_PROTOCOL, vlan_proto);
                        nlattr_set_len(nw, off2);
                }
                nlattr_set_len(nw, off);
        }
}

static int
vlan_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags)
{
        struct ifvlan *ifv = ifp->if_softc;
        int unit = ifp->if_dunit;

        if (ifp->if_vlantrunk)
                return (EBUSY);

#ifdef ALTQ
        IFQ_PURGE(&ifp->if_snd);
#endif
        ether_ifdetach(ifp);    /* first, remove it from system-wide lists */
        vlan_unconfig(ifp);     /* now it can be unconfigured and freed */
        /*
         * We should have the only reference to the ifv now, so we can now
         * drain any remaining lladdr task before freeing the ifnet and the
         * ifvlan.
         */
        taskqueue_drain(taskqueue_thread, &ifv->lladdr_task);
        NET_EPOCH_WAIT();
        if_free(ifp);
        free(ifv, M_VLAN);
        if (unit != IF_DUNIT_NONE)
                ifc_free_unit(ifc, unit);

        return (0);
}

/*
 * The ifp->if_init entry point for vlan(4) is a no-op.
 */
static void
vlan_init(void *foo __unused)
{
}

/*
 * The if_transmit method for vlan(4) interface.
 */
static int
vlan_transmit(struct ifnet *ifp, struct mbuf *m)
{
        struct ifvlan *ifv;
        struct ifnet *p;
        int error, len, mcast;

        NET_EPOCH_ASSERT();

        ifv = ifp->if_softc;
        if (TRUNK(ifv) == NULL) {
                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                m_freem(m);
                return (ENETDOWN);
        }
        p = PARENT(ifv);
        len = m->m_pkthdr.len;
        mcast = (m->m_flags & (M_MCAST | M_BCAST)) ? 1 : 0;

        BPF_MTAP(ifp, m);

#if defined(KERN_TLS) || defined(RATELIMIT)
        if (m->m_pkthdr.csum_flags & CSUM_SND_TAG) {
                struct vlan_snd_tag *vst;
                struct m_snd_tag *mst;

                MPASS(m->m_pkthdr.snd_tag->ifp == ifp);
                mst = m->m_pkthdr.snd_tag;
                vst = mst_to_vst(mst);
                if (vst->tag->ifp != p) {
                        if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                        m_freem(m);
                        return (EAGAIN);
                }

                m->m_pkthdr.snd_tag = m_snd_tag_ref(vst->tag);
                m_snd_tag_rele(mst);
        }
#endif

        /*
         * Do not run parent's if_transmit() if the parent is not up,
         * or parent's driver will cause a system crash.
         */
        if (!UP_AND_RUNNING(p)) {
                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                m_freem(m);
                return (ENETDOWN);
        }

        if (!ether_8021q_frame(&m, ifp, p, &ifv->ifv_qtag)) {
                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                return (0);
        }

        /*
         * Send it, precisely as ether_output() would have.
         */
        error = (p->if_transmit)(p, m);
        if (error == 0) {
                if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
                if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
                if_inc_counter(ifp, IFCOUNTER_OMCASTS, mcast);
        } else
                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
        return (error);
}

static int
vlan_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
    struct route *ro)
{
        struct ifvlan *ifv;
        struct ifnet *p;

        NET_EPOCH_ASSERT();

        /*
         * Find the first non-VLAN parent interface.
         */
        ifv = ifp->if_softc;
        do {
                if (TRUNK(ifv) == NULL) {
                        m_freem(m);
                        return (ENETDOWN);
                }
                p = PARENT(ifv);
                ifv = p->if_softc;
        } while (p->if_type == IFT_L2VLAN);

        return p->if_output(ifp, m, dst, ro);
}

#ifdef ALTQ
static void
vlan_altq_start(if_t ifp)
{
        struct ifaltq *ifq = &ifp->if_snd;
        struct mbuf *m;

        IFQ_LOCK(ifq);
        IFQ_DEQUEUE_NOLOCK(ifq, m);
        while (m != NULL) {
                vlan_transmit(ifp, m);
                IFQ_DEQUEUE_NOLOCK(ifq, m);
        }
        IFQ_UNLOCK(ifq);
}

static int
vlan_altq_transmit(if_t ifp, struct mbuf *m)
{
        int err;

        if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
                IFQ_ENQUEUE(&ifp->if_snd, m, err);
                if (err == 0)
                        vlan_altq_start(ifp);
        } else
                err = vlan_transmit(ifp, m);

        return (err);
}
#endif  /* ALTQ */

/*
 * The ifp->if_qflush entry point for vlan(4) is a no-op.
 */
static void
vlan_qflush(struct ifnet *ifp __unused)
{
}

static void
vlan_input(struct ifnet *ifp, struct mbuf *m)
{
        struct ifvlantrunk *trunk;
        struct ifvlan *ifv;
        struct m_tag *mtag;
        uint16_t vid, tag;

        NET_EPOCH_ASSERT();

        trunk = ifp->if_vlantrunk;
        if (trunk == NULL) {
                m_freem(m);
                return;
        }

        if (m->m_flags & M_VLANTAG) {
                /*
                 * Packet is tagged, but m contains a normal
                 * Ethernet frame; the tag is stored out-of-band.
                 */
                tag = m->m_pkthdr.ether_vtag;
                m->m_flags &= ~M_VLANTAG;
        } else {
                struct ether_vlan_header *evl;

                /*
                 * Packet is tagged in-band as specified by 802.1q.
                 */
                switch (ifp->if_type) {
                case IFT_ETHER:
                        if (m->m_len < sizeof(*evl) &&
                            (m = m_pullup(m, sizeof(*evl))) == NULL) {
                                if_printf(ifp, "cannot pullup VLAN header\n");
                                return;
                        }
                        evl = mtod(m, struct ether_vlan_header *);
                        tag = ntohs(evl->evl_tag);

                        /*
                         * Remove the 802.1q header by copying the Ethernet
                         * addresses over it and adjusting the beginning of
                         * the data in the mbuf.  The encapsulated Ethernet
                         * type field is already in place.
                         */
                        bcopy((char *)evl, (char *)evl + ETHER_VLAN_ENCAP_LEN,
                              ETHER_HDR_LEN - ETHER_TYPE_LEN);
                        m_adj(m, ETHER_VLAN_ENCAP_LEN);
                        break;

                default:
#ifdef INVARIANTS
                        panic("%s: %s has unsupported if_type %u",
                              __func__, ifp->if_xname, ifp->if_type);
#endif
                        if_inc_counter(ifp, IFCOUNTER_NOPROTO, 1);
                        m_freem(m);
                        return;
                }
        }

        vid = EVL_VLANOFTAG(tag);

        ifv = vlan_gethash(trunk, vid);
        if (ifv == NULL || !UP_AND_RUNNING(ifv->ifv_ifp)) {
                if_inc_counter(ifp, IFCOUNTER_NOPROTO, 1);
                m_freem(m);
                return;
        }

        if (V_vlan_mtag_pcp) {
                /*
                 * While uncommon, it is possible that we will find a 802.1q
                 * packet encapsulated inside another packet that also had an
                 * 802.1q header.  For example, ethernet tunneled over IPSEC
                 * arriving over ethernet.  In that case, we replace the
                 * existing 802.1q PCP m_tag value.
                 */
                mtag = m_tag_locate(m, MTAG_8021Q, MTAG_8021Q_PCP_IN, NULL);
                if (mtag == NULL) {
                        mtag = m_tag_alloc(MTAG_8021Q, MTAG_8021Q_PCP_IN,
                            sizeof(uint8_t), M_NOWAIT);
                        if (mtag == NULL) {
                                if_inc_counter(ifp, IFCOUNTER_IERRORS, 1);
                                m_freem(m);
                                return;
                        }
                        m_tag_prepend(m, mtag);
                }
                *(uint8_t *)(mtag + 1) = EVL_PRIOFTAG(tag);
        }

        m->m_pkthdr.rcvif = ifv->ifv_ifp;
        if_inc_counter(ifv->ifv_ifp, IFCOUNTER_IPACKETS, 1);

        /* Pass it back through the parent's input routine. */
        (*ifv->ifv_ifp->if_input)(ifv->ifv_ifp, m);
}

static void
vlan_lladdr_fn(void *arg, int pending __unused)
{
        struct ifvlan *ifv;
        struct ifnet *ifp;

        ifv = (struct ifvlan *)arg;
        ifp = ifv->ifv_ifp;

        CURVNET_SET(ifp->if_vnet);

        /* The ifv_ifp already has the lladdr copied in. */
        if_setlladdr(ifp, IF_LLADDR(ifp), ifp->if_addrlen);

        CURVNET_RESTORE();
}

static int
vlan_config(struct ifvlan *ifv, struct ifnet *p, uint16_t vid,
        uint16_t proto)
{
        struct epoch_tracker et;
        struct ifvlantrunk *trunk;
        struct ifnet *ifp;
        int error = 0;

        /*
         * We can handle non-ethernet hardware types as long as
         * they handle the tagging and headers themselves.
         */
        if (p->if_type != IFT_ETHER &&
            p->if_type != IFT_L2VLAN &&
            (p->if_capenable & IFCAP_VLAN_HWTAGGING) == 0)
                return (EPROTONOSUPPORT);
        if ((p->if_flags & VLAN_IFFLAGS) != VLAN_IFFLAGS)
                return (EPROTONOSUPPORT);
        /*
         * Don't let the caller set up a VLAN VID with
         * anything except VLID bits.
         * VID numbers 0x0 and 0xFFF are reserved.
         */
        if (vid == 0 || vid == 0xFFF || (vid & ~EVL_VLID_MASK))
                return (EINVAL);
        if (ifv->ifv_trunk) {
                trunk = ifv->ifv_trunk;
                if (trunk->parent != p)
                        return (EBUSY);

                VLAN_XLOCK();

                ifv->ifv_proto = proto;

                if (ifv->ifv_vid != vid) {
                        int oldvid = ifv->ifv_vid;

                        /* Re-hash */
                        vlan_remhash(trunk, ifv);
                        ifv->ifv_vid = vid;
                        error = vlan_inshash(trunk, ifv);
                        if (error) {
                                int ret __diagused;

                                ifv->ifv_vid = oldvid;
                                /* Re-insert back where we found it. */
                                ret = vlan_inshash(trunk, ifv);
                                MPASS(ret == 0);
                        }
                }
                /* Will unlock */
                goto done;
        }

        VLAN_XLOCK();
        if (p->if_vlantrunk == NULL) {
                trunk = malloc(sizeof(struct ifvlantrunk),
                    M_VLAN, M_WAITOK | M_ZERO);
                vlan_inithash(trunk);
                TRUNK_LOCK_INIT(trunk);
                TRUNK_WLOCK(trunk);
                p->if_vlantrunk = trunk;
                trunk->parent = p;
                if_ref(trunk->parent);
                TRUNK_WUNLOCK(trunk);
        } else {
                trunk = p->if_vlantrunk;
        }

        ifv->ifv_vid = vid;     /* must set this before vlan_inshash() */
        ifv->ifv_pcp = 0;       /* Default: best effort delivery. */
        error = vlan_inshash(trunk, ifv);
        if (error)
                goto done;
        ifv->ifv_proto = proto;
        ifv->ifv_encaplen = ETHER_VLAN_ENCAP_LEN;
        ifv->ifv_mintu = ETHERMIN;
        ifv->ifv_pflags = 0;
        ifv->ifv_capenable = -1;
        ifv->ifv_capenable2 = -1;

        /*
         * If the parent supports the VLAN_MTU capability,
         * i.e. can Tx/Rx larger than ETHER_MAX_LEN frames,
         * use it.
         */
        if (p->if_capenable & IFCAP_VLAN_MTU) {
                /*
                 * No need to fudge the MTU since the parent can
                 * handle extended frames.
                 */
                ifv->ifv_mtufudge = 0;
        } else {
                /*
                 * Fudge the MTU by the encapsulation size.  This
                 * makes us incompatible with strictly compliant
                 * 802.1Q implementations, but allows us to use
                 * the feature with other NetBSD implementations,
                 * which might still be useful.
                 */
                ifv->ifv_mtufudge = ifv->ifv_encaplen;
        }

        ifv->ifv_trunk = trunk;
        ifp = ifv->ifv_ifp;
        /*
         * Initialize fields from our parent.  This duplicates some
         * work with ether_ifattach() but allows for non-ethernet
         * interfaces to also work.
         */
        ifp->if_mtu = p->if_mtu - ifv->ifv_mtufudge;
        ifp->if_baudrate = p->if_baudrate;
        ifp->if_input = p->if_input;
        ifp->if_resolvemulti = p->if_resolvemulti;
        ifp->if_addrlen = p->if_addrlen;
        ifp->if_broadcastaddr = p->if_broadcastaddr;
        ifp->if_pcp = ifv->ifv_pcp;

        /*
         * We wrap the parent's if_output using vlan_output to ensure that it
         * can't become stale.
         */
        ifp->if_output = vlan_output;

        /*
         * Copy only a selected subset of flags from the parent.
         * Other flags are none of our business.
         */
#define VLAN_COPY_FLAGS (IFF_SIMPLEX)
        ifp->if_flags &= ~VLAN_COPY_FLAGS;
        ifp->if_flags |= p->if_flags & VLAN_COPY_FLAGS;
#undef VLAN_COPY_FLAGS

        ifp->if_link_state = p->if_link_state;

        NET_EPOCH_ENTER(et);
        vlan_capabilities(ifv);
        NET_EPOCH_EXIT(et);

        /*
         * Set up our interface address to reflect the underlying
         * physical interface's.
         */
        TASK_INIT(&ifv->lladdr_task, 0, vlan_lladdr_fn, ifv);
        ((struct sockaddr_dl *)ifp->if_addr->ifa_addr)->sdl_alen =
            p->if_addrlen;

        /*
         * Do not schedule link address update if it was the same
         * as previous parent's. This helps avoid updating for each
         * associated llentry.
         */
        if (memcmp(IF_LLADDR(p), IF_LLADDR(ifp), p->if_addrlen) != 0) {
                bcopy(IF_LLADDR(p), IF_LLADDR(ifp), p->if_addrlen);
                taskqueue_enqueue(taskqueue_thread, &ifv->lladdr_task);
        }

        /* We are ready for operation now. */
        ifp->if_drv_flags |= IFF_DRV_RUNNING;

        /* Update flags on the parent, if necessary. */
        vlan_setflags(ifp, 1);

        /*
         * Configure multicast addresses that may already be
         * joined on the vlan device.
         */
        (void)vlan_setmulti(ifp);

done:
        if (error == 0)
                EVENTHANDLER_INVOKE(vlan_config, p, ifv->ifv_vid);
        VLAN_XUNLOCK();

        return (error);
}

static void
vlan_unconfig(struct ifnet *ifp)
{

        VLAN_XLOCK();
        vlan_unconfig_locked(ifp, 0);
        VLAN_XUNLOCK();
}

static void
vlan_unconfig_locked(struct ifnet *ifp, int departing)
{
        struct ifvlantrunk *trunk;
        struct vlan_mc_entry *mc;
        struct ifvlan *ifv;
        struct ifnet  *parent;
        int error;

        VLAN_XLOCK_ASSERT();

        ifv = ifp->if_softc;
        trunk = ifv->ifv_trunk;
        parent = NULL;

        if (trunk != NULL) {
                parent = trunk->parent;

                /*
                 * 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.
                 */
                while ((mc = CK_SLIST_FIRST(&ifv->vlan_mc_listhead)) != NULL) {
                        /*
                         * If the parent interface is being detached,
                         * all its multicast addresses have already
                         * been removed.  Warn about errors if
                         * if_delmulti() does fail, but don't abort as
                         * all callers expect vlan destruction to
                         * succeed.
                         */
                        if (!departing) {
                                error = if_delmulti(parent,
                                    (struct sockaddr *)&mc->mc_addr);
                                if (error)
                                        if_printf(ifp,
                    "Failed to delete multicast address from parent: %d\n",
                                            error);
                        }
                        CK_SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries);
                        NET_EPOCH_CALL(vlan_mc_free, &mc->mc_epoch_ctx);
                }

                vlan_setflags(ifp, 0); /* clear special flags on parent */

                vlan_remhash(trunk, ifv);
                ifv->ifv_trunk = NULL;

                /*
                 * Check if we were the last.
                 */
                if (trunk->refcnt == 0) {
                        parent->if_vlantrunk = NULL;
                        NET_EPOCH_WAIT();
                        trunk_destroy(trunk);
                }
        }

        /* Disconnect from parent. */
        if (ifv->ifv_pflags)
                if_printf(ifp, "%s: ifv_pflags unclean\n", __func__);
        ifp->if_mtu = ETHERMTU;
        ifp->if_link_state = LINK_STATE_UNKNOWN;
        ifp->if_drv_flags &= ~IFF_DRV_RUNNING;

        /*
         * Only dispatch an event if vlan was
         * attached, otherwise there is nothing
         * to cleanup anyway.
         */
        if (parent != NULL)
                EVENTHANDLER_INVOKE(vlan_unconfig, parent, ifv->ifv_vid);
}

/* Handle a reference counted flag that should be set on the parent as well */
static int
vlan_setflag(struct ifnet *ifp, int flag, int status,
             int (*func)(struct ifnet *, int))
{
        struct ifvlan *ifv;
        int error;

        VLAN_SXLOCK_ASSERT();

        ifv = ifp->if_softc;
        status = status ? (ifp->if_flags & flag) : 0;
        /* Now "status" contains the flag value or 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 (status != (ifv->ifv_pflags & flag)) {
                error = (*func)(PARENT(ifv), status);
                if (error)
                        return (error);
                ifv->ifv_pflags &= ~flag;
                ifv->ifv_pflags |= status;
        }
        return (0);
}

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

        for (i = 0; vlan_pflags[i].flag; i++) {
                error = vlan_setflag(ifp, vlan_pflags[i].flag,
                                     status, vlan_pflags[i].func);
                if (error)
                        return (error);
        }
        return (0);
}

/* Inform all vlans that their parent has changed link state */
static void
vlan_link_state(struct ifnet *ifp)
{
        struct epoch_tracker et;
        struct ifvlantrunk *trunk;
        struct ifvlan *ifv;

        NET_EPOCH_ENTER(et);
        trunk = ifp->if_vlantrunk;
        if (trunk == NULL) {
                NET_EPOCH_EXIT(et);
                return;
        }

        TRUNK_WLOCK(trunk);
        VLAN_FOREACH(ifv, trunk) {
                ifv->ifv_ifp->if_baudrate = trunk->parent->if_baudrate;
                if_link_state_change(ifv->ifv_ifp,
                    trunk->parent->if_link_state);
        }
        TRUNK_WUNLOCK(trunk);
        NET_EPOCH_EXIT(et);
}

#ifdef IPSEC_OFFLOAD
#define VLAN_IPSEC_METHOD(exp)                          \
        if_t p;                                         \
        struct ifvlan *ifv;                             \
        int error;                                      \
                                                        \
        ifv = ifp->if_softc;                            \
        VLAN_SLOCK();                                   \
        if (TRUNK(ifv) != NULL) {                       \
                p = PARENT(ifv);                        \
                if_ref(p);                              \
                error = p->if_ipsec_accel_m->exp;       \
                if_rele(p);                             \
        } else {                                        \
                error = ENXIO;                          \
        }                                               \
        VLAN_SUNLOCK();                                 \
        return (error);


static int
vlan_if_spdadd(if_t ifp, void *sp, void *inp, void **priv)
{
        VLAN_IPSEC_METHOD(if_spdadd(ifp, sp, inp, priv));
}

static int
vlan_if_spddel(if_t ifp, void *sp, void *priv)
{
        VLAN_IPSEC_METHOD(if_spddel(ifp, sp, priv));
}

static int
vlan_if_sa_newkey(if_t ifp, void *sav, u_int drv_spi, void **privp)
{
        VLAN_IPSEC_METHOD(if_sa_newkey(ifp, sav, drv_spi, privp));
}

static int
vlan_if_sa_deinstall(if_t ifp, u_int drv_spi, void *priv)
{
        VLAN_IPSEC_METHOD(if_sa_deinstall(ifp, drv_spi, priv));
}

static int
vlan_if_sa_cnt(if_t ifp, void *sa, uint32_t drv_spi, void *priv,
    struct seclifetime *lt)
{
        VLAN_IPSEC_METHOD(if_sa_cnt(ifp, sa, drv_spi, priv, lt));
}

static int
vlan_if_ipsec_hwassist(if_t ifp, void *sav, u_int drv_spi,void *priv)
{
        if_t trunk;

        NET_EPOCH_ASSERT();
        trunk = vlan_trunkdev(ifp);
        if (trunk == NULL)
                return (0);
        return (trunk->if_ipsec_accel_m->if_hwassist(trunk, sav,
            drv_spi, priv));
}

static const struct if_ipsec_accel_methods vlan_if_ipsec_accel_methods = {
        .if_spdadd = vlan_if_spdadd,
        .if_spddel = vlan_if_spddel,
        .if_sa_newkey = vlan_if_sa_newkey,
        .if_sa_deinstall = vlan_if_sa_deinstall,
        .if_sa_cnt = vlan_if_sa_cnt,
        .if_hwassist = vlan_if_ipsec_hwassist,
};

#undef VLAN_IPSEC_METHOD
#endif  /* IPSEC_OFFLOAD */

static void
vlan_capabilities(struct ifvlan *ifv)
{
        struct ifnet *p;
        struct ifnet *ifp;
        struct ifnet_hw_tsomax hw_tsomax;
        int cap = 0, ena = 0, mena, cap2 = 0, ena2 = 0;
        int mena2 __unused;
        u_long hwa = 0;

        NET_EPOCH_ASSERT();
        VLAN_SXLOCK_ASSERT();

        p = PARENT(ifv);
        ifp = ifv->ifv_ifp;

        /* Mask parent interface enabled capabilities disabled by user. */
        mena = p->if_capenable & ifv->ifv_capenable;
        mena2 = p->if_capenable2 & ifv->ifv_capenable2;

        /*
         * If the parent interface can do checksum offloading
         * on VLANs, then propagate its hardware-assisted
         * checksumming flags. Also assert that checksum
         * offloading requires hardware VLAN tagging.
         */
        if (p->if_capabilities & IFCAP_VLAN_HWCSUM)
                cap |= p->if_capabilities & (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6);
        if (p->if_capenable & IFCAP_VLAN_HWCSUM &&
            p->if_capenable & IFCAP_VLAN_HWTAGGING) {
                ena |= mena & (IFCAP_HWCSUM | IFCAP_HWCSUM_IPV6);
                if (ena & IFCAP_TXCSUM)
                        hwa |= p->if_hwassist & (CSUM_IP | CSUM_TCP |
                            CSUM_UDP | CSUM_SCTP);
                if (ena & IFCAP_TXCSUM_IPV6)
                        hwa |= p->if_hwassist & (CSUM_TCP_IPV6 |
                            CSUM_UDP_IPV6 | CSUM_SCTP_IPV6);
        }

        /*
         * If the parent interface can do TSO on VLANs then
         * propagate the hardware-assisted flag. TSO on VLANs
         * does not necessarily require hardware VLAN tagging.
         */
        memset(&hw_tsomax, 0, sizeof(hw_tsomax));
        if_hw_tsomax_common(p, &hw_tsomax);
        if_hw_tsomax_update(ifp, &hw_tsomax);
        if (p->if_capabilities & IFCAP_VLAN_HWTSO)
                cap |= p->if_capabilities & IFCAP_TSO;
        if (p->if_capenable & IFCAP_VLAN_HWTSO) {
                ena |= mena & IFCAP_TSO;
                if (ena & IFCAP_TSO)
                        hwa |= p->if_hwassist & CSUM_TSO;
        }

        /*
         * If the parent interface can do LRO and checksum offloading on
         * VLANs, then guess it may do LRO on VLANs.  False positive here
         * cost nothing, while false negative may lead to some confusions.
         */
        if (p->if_capabilities & IFCAP_VLAN_HWCSUM)
                cap |= p->if_capabilities & IFCAP_LRO;
        if (p->if_capenable & IFCAP_VLAN_HWCSUM)
                ena |= mena & IFCAP_LRO;

        /*
         * If the parent interface can offload TCP connections over VLANs then
         * propagate its TOE capability to the VLAN interface.
         *
         * All TOE drivers in the tree today can deal with VLANs.  If this
         * changes then IFCAP_VLAN_TOE should be promoted to a full capability
         * with its own bit.
         */
#define IFCAP_VLAN_TOE IFCAP_TOE
        if (p->if_capabilities & IFCAP_VLAN_TOE)
                cap |= p->if_capabilities & IFCAP_TOE;
        if (p->if_capenable & IFCAP_VLAN_TOE) {
                SETTOEDEV(ifp, TOEDEV(p));
                ena |= mena & IFCAP_TOE;
        }

        /*
         * If the parent interface supports dynamic link state, so does the
         * VLAN interface.
         */
        cap |= (p->if_capabilities & IFCAP_LINKSTATE);
        ena |= (mena & IFCAP_LINKSTATE);

#ifdef RATELIMIT
        /*
         * If the parent interface supports ratelimiting, so does the
         * VLAN interface.
         */
        cap |= (p->if_capabilities & IFCAP_TXRTLMT);
        ena |= (mena & IFCAP_TXRTLMT);
#endif

        /*
         * If the parent interface supports unmapped mbufs, so does
         * the VLAN interface.  Note that this should be fine even for
         * interfaces that don't support hardware tagging as headers
         * are prepended in normal mbufs to unmapped mbufs holding
         * payload data.
         */
        cap |= (p->if_capabilities & IFCAP_MEXTPG);
        ena |= (mena & IFCAP_MEXTPG);

        /*
         * If the parent interface can offload encryption and segmentation
         * of TLS records over TCP, propagate it's capability to the VLAN
         * interface.
         *
         * All TLS drivers in the tree today can deal with VLANs.  If
         * this ever changes, then a new IFCAP_VLAN_TXTLS can be
         * defined.
         */
        if (p->if_capabilities & (IFCAP_TXTLS | IFCAP_TXTLS_RTLMT))
                cap |= p->if_capabilities & (IFCAP_TXTLS | IFCAP_TXTLS_RTLMT);
        if (p->if_capenable & (IFCAP_TXTLS | IFCAP_TXTLS_RTLMT))
                ena |= mena & (IFCAP_TXTLS | IFCAP_TXTLS_RTLMT);

        ifp->if_capabilities = cap;
        ifp->if_capenable = ena;
        ifp->if_hwassist = hwa;

#ifdef IPSEC_OFFLOAD
        cap2 |= p->if_capabilities2 & IFCAP2_BIT(IFCAP2_IPSEC_OFFLOAD);
        ena2 |= mena2 & IFCAP2_BIT(IFCAP2_IPSEC_OFFLOAD);
        ifp->if_ipsec_accel_m = &vlan_if_ipsec_accel_methods;
#endif

        ifp->if_capabilities2 = cap2;
        ifp->if_capenable2 = ena2;
}

static void
vlan_trunk_capabilities(struct ifnet *ifp)
{
        struct epoch_tracker et;
        struct ifvlantrunk *trunk;
        struct ifvlan *ifv;

        VLAN_SLOCK();
        trunk = ifp->if_vlantrunk;
        if (trunk == NULL) {
                VLAN_SUNLOCK();
                return;
        }
        NET_EPOCH_ENTER(et);
        VLAN_FOREACH(ifv, trunk)
                vlan_capabilities(ifv);
        NET_EPOCH_EXIT(et);
        VLAN_SUNLOCK();
}

static int
vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
{
        struct ifnet *p;
        struct ifreq *ifr;
#ifdef INET
        struct ifaddr *ifa;
#endif
        struct ifvlan *ifv;
        struct ifvlantrunk *trunk;
        struct vlanreq vlr;
        int error = 0, oldmtu;

        ifr = (struct ifreq *)data;
#ifdef INET
        ifa = (struct ifaddr *) data;
#endif
        ifv = ifp->if_softc;

        switch (cmd) {
        case SIOCSIFADDR:
                ifp->if_flags |= IFF_UP;
#ifdef INET
                if (ifa->ifa_addr->sa_family == AF_INET)
                        arp_ifinit(ifp, ifa);
#endif
                break;
        case SIOCGIFADDR:
                bcopy(IF_LLADDR(ifp), &ifr->ifr_addr.sa_data[0],
                    ifp->if_addrlen);
                break;
        case SIOCGIFMEDIA:
                VLAN_SLOCK();
                if (TRUNK(ifv) != NULL) {
                        p = PARENT(ifv);
                        if_ref(p);
                        error = (*p->if_ioctl)(p, SIOCGIFMEDIA, data);
                        if_rele(p);
                        /* 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;
                }
                VLAN_SUNLOCK();
                break;

        case SIOCSIFMEDIA:
                error = EINVAL;
                break;

        case SIOCSIFMTU:
                /*
                 * Set the interface MTU.
                 */
                VLAN_SLOCK();
                trunk = TRUNK(ifv);
                if (trunk != NULL) {
                        TRUNK_WLOCK(trunk);
                        if (ifr->ifr_mtu >
                             (PARENT(ifv)->if_mtu - ifv->ifv_mtufudge) ||
                            ifr->ifr_mtu <
                             (ifv->ifv_mintu - ifv->ifv_mtufudge))
                                error = EINVAL;
                        else
                                ifp->if_mtu = ifr->ifr_mtu;
                        TRUNK_WUNLOCK(trunk);
                } else
                        error = EINVAL;
                VLAN_SUNLOCK();
                break;

        case SIOCSETVLAN:
#ifdef VIMAGE
                /*
                 * XXXRW/XXXBZ: The goal in these checks is to allow a VLAN
                 * interface to be delegated to a jail without allowing the
                 * jail to change what underlying interface/VID it is
                 * associated with.  We are not entirely convinced that this
                 * is the right way to accomplish that policy goal.
                 */
                if (ifp->if_vnet != ifp->if_home_vnet) {
                        error = EPERM;
                        break;
                }
#endif
                error = copyin(ifr_data_get_ptr(ifr), &vlr, sizeof(vlr));
                if (error)
                        break;
                if (vlr.vlr_parent[0] == '\0') {
                        vlan_unconfig(ifp);
                        break;
                }
                p = ifunit_ref(vlr.vlr_parent);
                if (p == NULL) {
                        error = ENOENT;
                        break;
                }
                if (vlr.vlr_proto == 0)
                        vlr.vlr_proto = ETHERTYPE_VLAN;
                oldmtu = ifp->if_mtu;
                error = vlan_config(ifv, p, vlr.vlr_tag, vlr.vlr_proto);
                if_rele(p);

                /*
                 * VLAN MTU may change during addition of the vlandev.
                 * If it did, do network layer specific procedure.
                 */
                if (ifp->if_mtu != oldmtu)
                        if_notifymtu(ifp);
                break;

        case SIOCGETVLAN:
#ifdef VIMAGE
                if (ifp->if_vnet != ifp->if_home_vnet) {
                        error = EPERM;
                        break;
                }
#endif
                bzero(&vlr, sizeof(vlr));
                VLAN_SLOCK();
                if (TRUNK(ifv) != NULL) {
                        strlcpy(vlr.vlr_parent, PARENT(ifv)->if_xname,
                            sizeof(vlr.vlr_parent));
                        vlr.vlr_tag = ifv->ifv_vid;
                        vlr.vlr_proto = ifv->ifv_proto;
                }
                VLAN_SUNLOCK();
                error = copyout(&vlr, ifr_data_get_ptr(ifr), sizeof(vlr));
                break;

        case SIOCSIFFLAGS:
                /*
                 * We should propagate selected flags to the parent,
                 * e.g., promiscuous mode.
                 */
                VLAN_SLOCK();
                if (TRUNK(ifv) != NULL)
                        error = vlan_setflags(ifp, 1);
                VLAN_SUNLOCK();
                break;

        case SIOCADDMULTI:
        case SIOCDELMULTI:
                /*
                 * If we don't have a parent, just remember the membership for
                 * when we do.
                 *
                 * XXX We need the rmlock here to avoid sleeping while
                 * holding in6_multi_mtx.
                 */
                VLAN_XLOCK();
                trunk = TRUNK(ifv);
                if (trunk != NULL)
                        error = vlan_setmulti(ifp);
                VLAN_XUNLOCK();

                break;
        case SIOCGVLANPCP:
#ifdef VIMAGE
                if (ifp->if_vnet != ifp->if_home_vnet) {
                        error = EPERM;
                        break;
                }
#endif
                ifr->ifr_vlan_pcp = ifv->ifv_pcp;
                break;

        case SIOCSVLANPCP:
#ifdef VIMAGE
                if (ifp->if_vnet != ifp->if_home_vnet) {
                        error = EPERM;
                        break;
                }
#endif
                error = priv_check(curthread, PRIV_NET_SETVLANPCP);
                if (error)
                        break;
                if (ifr->ifr_vlan_pcp > VLAN_PCP_MAX) {
                        error = EINVAL;
                        break;
                }
                ifv->ifv_pcp = ifr->ifr_vlan_pcp;
                ifp->if_pcp = ifv->ifv_pcp;
                /* broadcast event about PCP change */
                EVENTHANDLER_INVOKE(ifnet_event, ifp, IFNET_EVENT_PCP);
                break;

        case SIOCSIFCAP:
                VLAN_SLOCK();
                ifv->ifv_capenable = ifr->ifr_reqcap;
                trunk = TRUNK(ifv);
                if (trunk != NULL) {
                        struct epoch_tracker et;

                        NET_EPOCH_ENTER(et);
                        vlan_capabilities(ifv);
                        NET_EPOCH_EXIT(et);
                }
                VLAN_SUNLOCK();
                break;

        default:
                error = EINVAL;
                break;
        }

        return (error);
}

#if defined(KERN_TLS) || defined(RATELIMIT)
static int
vlan_snd_tag_alloc(struct ifnet *ifp,
    union if_snd_tag_alloc_params *params,
    struct m_snd_tag **ppmt)
{
        struct epoch_tracker et;
        const struct if_snd_tag_sw *sw;
        struct vlan_snd_tag *vst;
        struct ifvlan *ifv;
        struct ifnet *parent;
        struct m_snd_tag *mst;
        int error;

        NET_EPOCH_ENTER(et);
        ifv = ifp->if_softc;

        switch (params->hdr.type) {
#ifdef RATELIMIT
        case IF_SND_TAG_TYPE_UNLIMITED:
                sw = &vlan_snd_tag_ul_sw;
                break;
        case IF_SND_TAG_TYPE_RATE_LIMIT:
                sw = &vlan_snd_tag_rl_sw;
                break;
#endif
#ifdef KERN_TLS
        case IF_SND_TAG_TYPE_TLS:
                sw = &vlan_snd_tag_tls_sw;
                break;
        case IF_SND_TAG_TYPE_TLS_RX:
                sw = NULL;
                if (params->tls_rx.vlan_id != 0)
                        goto failure;
                params->tls_rx.vlan_id = ifv->ifv_vid;
                break;
#ifdef RATELIMIT
        case IF_SND_TAG_TYPE_TLS_RATE_LIMIT:
                sw = &vlan_snd_tag_tls_rl_sw;
                break;
#endif
#endif
        default:
                goto failure;
        }

        if (ifv->ifv_trunk != NULL)
                parent = PARENT(ifv);
        else
                parent = NULL;
        if (parent == NULL)
                goto failure;
        if_ref(parent);
        NET_EPOCH_EXIT(et);

        if (sw != NULL) {
                vst = malloc(sizeof(*vst), M_VLAN, M_NOWAIT);
                if (vst == NULL) {
                        if_rele(parent);
                        return (ENOMEM);
                }
        } else
                vst = NULL;

        error = m_snd_tag_alloc(parent, params, &mst);
        if_rele(parent);
        if (error) {
                free(vst, M_VLAN);
                return (error);
        }

        if (sw != NULL) {
                m_snd_tag_init(&vst->com, ifp, sw);
                vst->tag = mst;

                *ppmt = &vst->com;
        } else
                *ppmt = mst;

        return (0);
failure:
        NET_EPOCH_EXIT(et);
        return (EOPNOTSUPP);
}

static struct m_snd_tag *
vlan_next_snd_tag(struct m_snd_tag *mst)
{
        struct vlan_snd_tag *vst;

        vst = mst_to_vst(mst);
        return (vst->tag);
}

static int
vlan_snd_tag_modify(struct m_snd_tag *mst,
    union if_snd_tag_modify_params *params)
{
        struct vlan_snd_tag *vst;

        vst = mst_to_vst(mst);
        return (vst->tag->sw->snd_tag_modify(vst->tag, params));
}

static int
vlan_snd_tag_query(struct m_snd_tag *mst,
    union if_snd_tag_query_params *params)
{
        struct vlan_snd_tag *vst;

        vst = mst_to_vst(mst);
        return (vst->tag->sw->snd_tag_query(vst->tag, params));
}

static void
vlan_snd_tag_free(struct m_snd_tag *mst)
{
        struct vlan_snd_tag *vst;

        vst = mst_to_vst(mst);
        m_snd_tag_rele(vst->tag);
        free(vst, M_VLAN);
}

static void
vlan_ratelimit_query(struct ifnet *ifp __unused, struct if_ratelimit_query_results *q)
{
        /*
         * For vlan, we have an indirect
         * interface. The caller needs to
         * get a ratelimit tag on the actual
         * interface the flow will go on.
         */
        q->rate_table = NULL;
        q->flags = RT_IS_INDIRECT;
        q->max_flows = 0;
        q->number_of_rates = 0;
}

#endif