WiP merge of libzfs_core (MFV r238590, r238592)

[FreeBSD/FreeBSD.git] / sys / net80211 / ieee80211_node.c

/*-
 * Copyright (c) 2001 Atsushi Onoe
 * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR 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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_wlan.h"

#include <sys/param.h>
#include <sys/systm.h> 
#include <sys/mbuf.h>   
#include <sys/malloc.h>
#include <sys/kernel.h>

#include <sys/socket.h>
 
#include <net/if.h>
#include <net/if_media.h>
#include <net/ethernet.h>

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_input.h>
#ifdef IEEE80211_SUPPORT_SUPERG
#include <net80211/ieee80211_superg.h>
#endif
#ifdef IEEE80211_SUPPORT_TDMA
#include <net80211/ieee80211_tdma.h>
#endif
#include <net80211/ieee80211_wds.h>
#include <net80211/ieee80211_mesh.h>
#include <net80211/ieee80211_ratectl.h>

#include <net/bpf.h>

/*
 * IEEE80211_NODE_HASHSIZE must be a power of 2.
 */
CTASSERT((IEEE80211_NODE_HASHSIZE & (IEEE80211_NODE_HASHSIZE-1)) == 0);

/*
 * Association id's are managed with a bit vector.
 */
#define IEEE80211_AID_SET(_vap, b) \
        ((_vap)->iv_aid_bitmap[IEEE80211_AID(b) / 32] |= \
                (1 << (IEEE80211_AID(b) % 32)))
#define IEEE80211_AID_CLR(_vap, b) \
        ((_vap)->iv_aid_bitmap[IEEE80211_AID(b) / 32] &= \
                ~(1 << (IEEE80211_AID(b) % 32)))
#define IEEE80211_AID_ISSET(_vap, b) \
        ((_vap)->iv_aid_bitmap[IEEE80211_AID(b) / 32] & (1 << (IEEE80211_AID(b) % 32)))

#ifdef IEEE80211_DEBUG_REFCNT
#define REFCNT_LOC "%s (%s:%u) %p<%s> refcnt %d\n", __func__, func, line
#else
#define REFCNT_LOC "%s %p<%s> refcnt %d\n", __func__
#endif

static int ieee80211_sta_join1(struct ieee80211_node *);

static struct ieee80211_node *node_alloc(struct ieee80211vap *,
        const uint8_t [IEEE80211_ADDR_LEN]);
static void node_cleanup(struct ieee80211_node *);
static void node_free(struct ieee80211_node *);
static void node_age(struct ieee80211_node *);
static int8_t node_getrssi(const struct ieee80211_node *);
static void node_getsignal(const struct ieee80211_node *, int8_t *, int8_t *);
static void node_getmimoinfo(const struct ieee80211_node *,
        struct ieee80211_mimo_info *);

static void _ieee80211_free_node(struct ieee80211_node *);

static void ieee80211_node_table_init(struct ieee80211com *ic,
        struct ieee80211_node_table *nt, const char *name,
        int inact, int keymaxix);
static void ieee80211_node_table_reset(struct ieee80211_node_table *,
        struct ieee80211vap *);
static void ieee80211_node_table_cleanup(struct ieee80211_node_table *nt);
static void ieee80211_erp_timeout(struct ieee80211com *);

MALLOC_DEFINE(M_80211_NODE, "80211node", "802.11 node state");
MALLOC_DEFINE(M_80211_NODE_IE, "80211nodeie", "802.11 node ie");

void
ieee80211_node_attach(struct ieee80211com *ic)
{
        /* XXX really want maxlen enforced per-sta */
        ieee80211_ageq_init(&ic->ic_stageq, ic->ic_max_keyix * 8,
            "802.11 staging q");
        ieee80211_node_table_init(ic, &ic->ic_sta, "station",
                IEEE80211_INACT_INIT, ic->ic_max_keyix);
        callout_init(&ic->ic_inact, CALLOUT_MPSAFE);
        callout_reset(&ic->ic_inact, IEEE80211_INACT_WAIT*hz,
                ieee80211_node_timeout, ic);

        ic->ic_node_alloc = node_alloc;
        ic->ic_node_free = node_free;
        ic->ic_node_cleanup = node_cleanup;
        ic->ic_node_age = node_age;
        ic->ic_node_drain = node_age;           /* NB: same as age */
        ic->ic_node_getrssi = node_getrssi;
        ic->ic_node_getsignal = node_getsignal;
        ic->ic_node_getmimoinfo = node_getmimoinfo;

        /*
         * Set flags to be propagated to all vap's;
         * these define default behaviour/configuration.
         */
        ic->ic_flags_ext |= IEEE80211_FEXT_INACT; /* inactivity processing */
}

void
ieee80211_node_detach(struct ieee80211com *ic)
{

        callout_drain(&ic->ic_inact);
        ieee80211_node_table_cleanup(&ic->ic_sta);
        ieee80211_ageq_cleanup(&ic->ic_stageq);
}

void
ieee80211_node_vattach(struct ieee80211vap *vap)
{
        /* NB: driver can override */
        vap->iv_max_aid = IEEE80211_AID_DEF;

        /* default station inactivity timer setings */
        vap->iv_inact_init = IEEE80211_INACT_INIT;
        vap->iv_inact_auth = IEEE80211_INACT_AUTH;
        vap->iv_inact_run = IEEE80211_INACT_RUN;
        vap->iv_inact_probe = IEEE80211_INACT_PROBE;

        IEEE80211_DPRINTF(vap, IEEE80211_MSG_INACT,
            "%s: init %u auth %u run %u probe %u\n", __func__,
            vap->iv_inact_init, vap->iv_inact_auth,
            vap->iv_inact_run, vap->iv_inact_probe);
}

void
ieee80211_node_latevattach(struct ieee80211vap *vap)
{
        if (vap->iv_opmode == IEEE80211_M_HOSTAP) {
                /* XXX should we allow max aid to be zero? */
                if (vap->iv_max_aid < IEEE80211_AID_MIN) {
                        vap->iv_max_aid = IEEE80211_AID_MIN;
                        if_printf(vap->iv_ifp,
                            "WARNING: max aid too small, changed to %d\n",
                            vap->iv_max_aid);
                }
                vap->iv_aid_bitmap = (uint32_t *) malloc(
                        howmany(vap->iv_max_aid, 32) * sizeof(uint32_t),
                        M_80211_NODE, M_NOWAIT | M_ZERO);
                if (vap->iv_aid_bitmap == NULL) {
                        /* XXX no way to recover */
                        printf("%s: no memory for AID bitmap, max aid %d!\n",
                            __func__, vap->iv_max_aid);
                        vap->iv_max_aid = 0;
                }
        }

        ieee80211_reset_bss(vap);

        vap->iv_auth = ieee80211_authenticator_get(vap->iv_bss->ni_authmode);
}

void
ieee80211_node_vdetach(struct ieee80211vap *vap)
{
        struct ieee80211com *ic = vap->iv_ic;

        ieee80211_node_table_reset(&ic->ic_sta, vap);
        if (vap->iv_bss != NULL) {
                ieee80211_free_node(vap->iv_bss);
                vap->iv_bss = NULL;
        }
        if (vap->iv_aid_bitmap != NULL) {
                free(vap->iv_aid_bitmap, M_80211_NODE);
                vap->iv_aid_bitmap = NULL;
        }
}

/* 
 * Port authorize/unauthorize interfaces for use by an authenticator.
 */

void
ieee80211_node_authorize(struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;

        ni->ni_flags |= IEEE80211_NODE_AUTH;
        ni->ni_inact_reload = vap->iv_inact_run;
        ni->ni_inact = ni->ni_inact_reload;

        IEEE80211_NOTE(vap, IEEE80211_MSG_INACT, ni,
            "%s: inact_reload %u", __func__, ni->ni_inact_reload);
}

void
ieee80211_node_unauthorize(struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;

        ni->ni_flags &= ~IEEE80211_NODE_AUTH;
        ni->ni_inact_reload = vap->iv_inact_auth;
        if (ni->ni_inact > ni->ni_inact_reload)
                ni->ni_inact = ni->ni_inact_reload;

        IEEE80211_NOTE(vap, IEEE80211_MSG_INACT, ni,
            "%s: inact_reload %u inact %u", __func__,
            ni->ni_inact_reload, ni->ni_inact);
}

/*
 * Fix tx parameters for a node according to ``association state''.
 */
void
ieee80211_node_setuptxparms(struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;
        enum ieee80211_phymode mode;

        if (ni->ni_flags & IEEE80211_NODE_HT) {
                if (IEEE80211_IS_CHAN_5GHZ(ni->ni_chan))
                        mode = IEEE80211_MODE_11NA;
                else
                        mode = IEEE80211_MODE_11NG;
        } else {                                /* legacy rate handling */
                if (IEEE80211_IS_CHAN_ST(ni->ni_chan))
                        mode = IEEE80211_MODE_STURBO_A;
                else if (IEEE80211_IS_CHAN_HALF(ni->ni_chan))
                        mode = IEEE80211_MODE_HALF;
                else if (IEEE80211_IS_CHAN_QUARTER(ni->ni_chan))
                        mode = IEEE80211_MODE_QUARTER;
                /* NB: 108A should be handled as 11a */
                else if (IEEE80211_IS_CHAN_A(ni->ni_chan))
                        mode = IEEE80211_MODE_11A;
                else if (IEEE80211_IS_CHAN_108G(ni->ni_chan) ||
                    (ni->ni_flags & IEEE80211_NODE_ERP))
                        mode = IEEE80211_MODE_11G;
                else
                        mode = IEEE80211_MODE_11B;
        }
        ni->ni_txparms = &vap->iv_txparms[mode];
}

/*
 * Set/change the channel.  The rate set is also updated as
 * to insure a consistent view by drivers.
 * XXX should be private but hostap needs it to deal with CSA
 */
void
ieee80211_node_set_chan(struct ieee80211_node *ni,
        struct ieee80211_channel *chan)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct ieee80211vap *vap = ni->ni_vap;
        enum ieee80211_phymode mode;

        KASSERT(chan != IEEE80211_CHAN_ANYC, ("no channel"));

        ni->ni_chan = chan;
        mode = ieee80211_chan2mode(chan);
        if (IEEE80211_IS_CHAN_HT(chan)) {
                /*
                 * We must install the legacy rate est in ni_rates and the
                 * HT rate set in ni_htrates.
                 */
                ni->ni_htrates = *ieee80211_get_suphtrates(ic, chan);
                /*
                 * Setup bss tx parameters based on operating mode.  We
                 * use legacy rates when operating in a mixed HT+non-HT bss
                 * and non-ERP rates in 11g for mixed ERP+non-ERP bss.
                 */
                if (mode == IEEE80211_MODE_11NA &&
                    (vap->iv_flags_ht & IEEE80211_FHT_PUREN) == 0)
                        mode = IEEE80211_MODE_11A;
                else if (mode == IEEE80211_MODE_11NG &&
                    (vap->iv_flags_ht & IEEE80211_FHT_PUREN) == 0)
                        mode = IEEE80211_MODE_11G;
                if (mode == IEEE80211_MODE_11G &&
                    (vap->iv_flags & IEEE80211_F_PUREG) == 0)
                        mode = IEEE80211_MODE_11B;
        }
        ni->ni_txparms = &vap->iv_txparms[mode];
        ni->ni_rates = *ieee80211_get_suprates(ic, chan);
}

static __inline void
copy_bss(struct ieee80211_node *nbss, const struct ieee80211_node *obss)
{
        /* propagate useful state */
        nbss->ni_authmode = obss->ni_authmode;
        nbss->ni_txpower = obss->ni_txpower;
        nbss->ni_vlan = obss->ni_vlan;
        /* XXX statistics? */
        /* XXX legacy WDS bssid? */
}

void
ieee80211_create_ibss(struct ieee80211vap* vap, struct ieee80211_channel *chan)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ieee80211_node *ni;

        IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
                "%s: creating %s on channel %u\n", __func__,
                ieee80211_opmode_name[vap->iv_opmode],
                ieee80211_chan2ieee(ic, chan));

        ni = ieee80211_alloc_node(&ic->ic_sta, vap, vap->iv_myaddr);
        if (ni == NULL) {
                /* XXX recovery? */
                return;
        }
        IEEE80211_ADDR_COPY(ni->ni_bssid, vap->iv_myaddr);
        ni->ni_esslen = vap->iv_des_ssid[0].len;
        memcpy(ni->ni_essid, vap->iv_des_ssid[0].ssid, ni->ni_esslen);
        if (vap->iv_bss != NULL)
                copy_bss(ni, vap->iv_bss);
        ni->ni_intval = ic->ic_bintval;
        if (vap->iv_flags & IEEE80211_F_PRIVACY)
                ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
        if (ic->ic_phytype == IEEE80211_T_FH) {
                ni->ni_fhdwell = 200;   /* XXX */
                ni->ni_fhindex = 1;
        }
        if (vap->iv_opmode == IEEE80211_M_IBSS) {
                vap->iv_flags |= IEEE80211_F_SIBSS;
                ni->ni_capinfo |= IEEE80211_CAPINFO_IBSS;       /* XXX */
                if (vap->iv_flags & IEEE80211_F_DESBSSID)
                        IEEE80211_ADDR_COPY(ni->ni_bssid, vap->iv_des_bssid);
                else {
                        get_random_bytes(ni->ni_bssid, IEEE80211_ADDR_LEN);
                        /* clear group bit, add local bit */
                        ni->ni_bssid[0] = (ni->ni_bssid[0] &~ 0x01) | 0x02;
                }
        } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
                if (vap->iv_flags & IEEE80211_F_DESBSSID)
                        IEEE80211_ADDR_COPY(ni->ni_bssid, vap->iv_des_bssid);
                else
#ifdef IEEE80211_SUPPORT_TDMA
                if ((vap->iv_caps & IEEE80211_C_TDMA) == 0)
#endif
                        memset(ni->ni_bssid, 0, IEEE80211_ADDR_LEN);
#ifdef IEEE80211_SUPPORT_MESH
        } else if (vap->iv_opmode == IEEE80211_M_MBSS) {
                ni->ni_meshidlen = vap->iv_mesh->ms_idlen;
                memcpy(ni->ni_meshid, vap->iv_mesh->ms_id, ni->ni_meshidlen);
#endif
        }
        /* 
         * Fix the channel and related attributes.
         */
        /* clear DFS CAC state on previous channel */
        if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
            ic->ic_bsschan->ic_freq != chan->ic_freq &&
            IEEE80211_IS_CHAN_CACDONE(ic->ic_bsschan))
                ieee80211_dfs_cac_clear(ic, ic->ic_bsschan);
        ic->ic_bsschan = chan;
        ieee80211_node_set_chan(ni, chan);
        ic->ic_curmode = ieee80211_chan2mode(chan);
        /*
         * Do mode-specific setup.
         */
        if (IEEE80211_IS_CHAN_FULL(chan)) {
                if (IEEE80211_IS_CHAN_ANYG(chan)) {
                        /*
                         * Use a mixed 11b/11g basic rate set.
                         */
                        ieee80211_setbasicrates(&ni->ni_rates,
                            IEEE80211_MODE_11G);
                        if (vap->iv_flags & IEEE80211_F_PUREG) {
                                /*
                                 * Also mark OFDM rates basic so 11b
                                 * stations do not join (WiFi compliance).
                                 */
                                ieee80211_addbasicrates(&ni->ni_rates,
                                    IEEE80211_MODE_11A);
                        }
                } else if (IEEE80211_IS_CHAN_B(chan)) {
                        /*
                         * Force pure 11b rate set.
                         */
                        ieee80211_setbasicrates(&ni->ni_rates,
                                IEEE80211_MODE_11B);
                }
        }

        (void) ieee80211_sta_join1(ieee80211_ref_node(ni));
}

/*
 * Reset bss state on transition to the INIT state.
 * Clear any stations from the table (they have been
 * deauth'd) and reset the bss node (clears key, rate
 * etc. state).
 */
void
ieee80211_reset_bss(struct ieee80211vap *vap)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ieee80211_node *ni, *obss;

        ieee80211_node_table_reset(&ic->ic_sta, vap);
        /* XXX multi-bss: wrong */
        ieee80211_reset_erp(ic);

        ni = ieee80211_alloc_node(&ic->ic_sta, vap, vap->iv_myaddr);
        KASSERT(ni != NULL, ("unable to setup initial BSS node"));
        obss = vap->iv_bss;
        vap->iv_bss = ieee80211_ref_node(ni);
        if (obss != NULL) {
                copy_bss(ni, obss);
                ni->ni_intval = ic->ic_bintval;
                ieee80211_free_node(obss);
        } else
                IEEE80211_ADDR_COPY(ni->ni_bssid, vap->iv_myaddr);
}

static int
match_ssid(const struct ieee80211_node *ni,
        int nssid, const struct ieee80211_scan_ssid ssids[])
{
        int i;

        for (i = 0; i < nssid; i++) {
                if (ni->ni_esslen == ssids[i].len &&
                     memcmp(ni->ni_essid, ssids[i].ssid, ni->ni_esslen) == 0)
                        return 1;
        }
        return 0;
}

/*
 * Test a node for suitability/compatibility.
 */
static int
check_bss(struct ieee80211vap *vap, struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;
        uint8_t rate;

        if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
                return 0;
        if (vap->iv_opmode == IEEE80211_M_IBSS) {
                if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
                        return 0;
        } else {
                if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
                        return 0;
        }
        if (vap->iv_flags & IEEE80211_F_PRIVACY) {
                if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
                        return 0;
        } else {
                /* XXX does this mean privacy is supported or required? */
                if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
                        return 0;
        }
        rate = ieee80211_fix_rate(ni, &ni->ni_rates,
            IEEE80211_F_JOIN | IEEE80211_F_DONEGO | IEEE80211_F_DOFRATE);
        if (rate & IEEE80211_RATE_BASIC)
                return 0;
        if (vap->iv_des_nssid != 0 &&
            !match_ssid(ni, vap->iv_des_nssid, vap->iv_des_ssid))
                return 0;
        if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
            !IEEE80211_ADDR_EQ(vap->iv_des_bssid, ni->ni_bssid))
                return 0;
        return 1;
}

#ifdef IEEE80211_DEBUG
/*
 * Display node suitability/compatibility.
 */
static void
check_bss_debug(struct ieee80211vap *vap, struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;
        uint8_t rate;
        int fail;

        fail = 0;
        if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
                fail |= 0x01;
        if (vap->iv_opmode == IEEE80211_M_IBSS) {
                if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
                        fail |= 0x02;
        } else {
                if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
                        fail |= 0x02;
        }
        if (vap->iv_flags & IEEE80211_F_PRIVACY) {
                if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
                        fail |= 0x04;
        } else {
                /* XXX does this mean privacy is supported or required? */
                if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
                        fail |= 0x04;
        }
        rate = ieee80211_fix_rate(ni, &ni->ni_rates,
             IEEE80211_F_JOIN | IEEE80211_F_DONEGO | IEEE80211_F_DOFRATE);
        if (rate & IEEE80211_RATE_BASIC)
                fail |= 0x08;
        if (vap->iv_des_nssid != 0 &&
            !match_ssid(ni, vap->iv_des_nssid, vap->iv_des_ssid))
                fail |= 0x10;
        if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
            !IEEE80211_ADDR_EQ(vap->iv_des_bssid, ni->ni_bssid))
                fail |= 0x20;

        printf(" %c %s", fail ? '-' : '+', ether_sprintf(ni->ni_macaddr));
        printf(" %s%c", ether_sprintf(ni->ni_bssid), fail & 0x20 ? '!' : ' ');
        printf(" %3d%c",
            ieee80211_chan2ieee(ic, ni->ni_chan), fail & 0x01 ? '!' : ' ');
        printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
            fail & 0x08 ? '!' : ' ');
        printf(" %4s%c",
            (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
            (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
            "????",
            fail & 0x02 ? '!' : ' ');
        printf(" %3s%c ",
            (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ?  "wep" : "no",
            fail & 0x04 ? '!' : ' ');
        ieee80211_print_essid(ni->ni_essid, ni->ni_esslen);
        printf("%s\n", fail & 0x10 ? "!" : "");
}
#endif /* IEEE80211_DEBUG */
 
/*
 * Handle 802.11 ad hoc network merge.  The
 * convention, set by the Wireless Ethernet Compatibility Alliance
 * (WECA), is that an 802.11 station will change its BSSID to match
 * the "oldest" 802.11 ad hoc network, on the same channel, that
 * has the station's desired SSID.  The "oldest" 802.11 network
 * sends beacons with the greatest TSF timestamp.
 *
 * The caller is assumed to validate TSF's before attempting a merge.
 *
 * Return !0 if the BSSID changed, 0 otherwise.
 */
int
ieee80211_ibss_merge(struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;
#ifdef IEEE80211_DEBUG
        struct ieee80211com *ic = ni->ni_ic;
#endif

        if (ni == vap->iv_bss ||
            IEEE80211_ADDR_EQ(ni->ni_bssid, vap->iv_bss->ni_bssid)) {
                /* unchanged, nothing to do */
                return 0;
        }
        if (!check_bss(vap, ni)) {
                /* capabilities mismatch */
                IEEE80211_DPRINTF(vap, IEEE80211_MSG_ASSOC,
                    "%s: merge failed, capabilities mismatch\n", __func__);
#ifdef IEEE80211_DEBUG
                if (ieee80211_msg_assoc(vap))
                        check_bss_debug(vap, ni);
#endif
                vap->iv_stats.is_ibss_capmismatch++;
                return 0;
        }
        IEEE80211_DPRINTF(vap, IEEE80211_MSG_ASSOC,
                "%s: new bssid %s: %s preamble, %s slot time%s\n", __func__,
                ether_sprintf(ni->ni_bssid),
                ic->ic_flags&IEEE80211_F_SHPREAMBLE ? "short" : "long",
                ic->ic_flags&IEEE80211_F_SHSLOT ? "short" : "long",
                ic->ic_flags&IEEE80211_F_USEPROT ? ", protection" : ""
        );
        return ieee80211_sta_join1(ieee80211_ref_node(ni));
}

/*
 * Calculate HT channel promotion flags for all vaps.
 * This assumes ni_chan have been setup for each vap.
 */
static int
gethtadjustflags(struct ieee80211com *ic)
{
        struct ieee80211vap *vap;
        int flags;

        flags = 0;
        /* XXX locking */
        TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
                if (vap->iv_state < IEEE80211_S_RUN)
                        continue;
                switch (vap->iv_opmode) {
                case IEEE80211_M_WDS:
                case IEEE80211_M_STA:
                case IEEE80211_M_AHDEMO:
                case IEEE80211_M_HOSTAP:
                case IEEE80211_M_IBSS:
                case IEEE80211_M_MBSS:
                        flags |= ieee80211_htchanflags(vap->iv_bss->ni_chan);
                        break;
                default:
                        break;
                }
        }
        return flags;
}

/*
 * Check if the current channel needs to change based on whether
 * any vap's are using HT20/HT40.  This is used to sync the state
 * of ic_curchan after a channel width change on a running vap.
 */
void
ieee80211_sync_curchan(struct ieee80211com *ic)
{
        struct ieee80211_channel *c;

        c = ieee80211_ht_adjust_channel(ic, ic->ic_curchan, gethtadjustflags(ic));
        if (c != ic->ic_curchan) {
                ic->ic_curchan = c;
                ic->ic_curmode = ieee80211_chan2mode(ic->ic_curchan);
                ic->ic_rt = ieee80211_get_ratetable(ic->ic_curchan);
                IEEE80211_UNLOCK(ic);
                ic->ic_set_channel(ic);
                ieee80211_radiotap_chan_change(ic);
                IEEE80211_LOCK(ic);
        }
}

/*
 * Setup the current channel.  The request channel may be
 * promoted if other vap's are operating with HT20/HT40.
 */
void
ieee80211_setupcurchan(struct ieee80211com *ic, struct ieee80211_channel *c)
{
        if (ic->ic_htcaps & IEEE80211_HTC_HT) {
                int flags = gethtadjustflags(ic);
                /*
                 * Check for channel promotion required to support the
                 * set of running vap's.  This assumes we are called
                 * after ni_chan is setup for each vap.
                 */
                /* NB: this assumes IEEE80211_FHT_USEHT40 > IEEE80211_FHT_HT */
                if (flags > ieee80211_htchanflags(c))
                        c = ieee80211_ht_adjust_channel(ic, c, flags);
        }
        ic->ic_bsschan = ic->ic_curchan = c;
        ic->ic_curmode = ieee80211_chan2mode(ic->ic_curchan);
        ic->ic_rt = ieee80211_get_ratetable(ic->ic_curchan);
}

/*
 * Change the current channel.  The channel change is guaranteed to have
 * happened before the next state change.
 */
void
ieee80211_setcurchan(struct ieee80211com *ic, struct ieee80211_channel *c)
{
        ieee80211_setupcurchan(ic, c);
        ieee80211_runtask(ic, &ic->ic_chan_task);
}

void
ieee80211_update_chw(struct ieee80211com *ic)
{

        ieee80211_setupcurchan(ic, ic->ic_curchan);
        ieee80211_runtask(ic, &ic->ic_chw_task);
}

/*
 * Join the specified IBSS/BSS network.  The node is assumed to
 * be passed in with a held reference.
 */
static int
ieee80211_sta_join1(struct ieee80211_node *selbs)
{
        struct ieee80211vap *vap = selbs->ni_vap;
        struct ieee80211com *ic = selbs->ni_ic;
        struct ieee80211_node *obss;
        int canreassoc;

        /*
         * Committed to selbs, setup state.
         */
        obss = vap->iv_bss;
        /*
         * Check if old+new node have the same address in which
         * case we can reassociate when operating in sta mode.
         */
        canreassoc = (obss != NULL &&
                vap->iv_state == IEEE80211_S_RUN &&
                IEEE80211_ADDR_EQ(obss->ni_macaddr, selbs->ni_macaddr));
        vap->iv_bss = selbs;            /* NB: caller assumed to bump refcnt */
        if (obss != NULL) {
                copy_bss(selbs, obss);
                ieee80211_node_decref(obss);    /* iv_bss reference */
                ieee80211_free_node(obss);      /* station table reference */
                obss = NULL;            /* NB: guard against later use */
        }

        /*
         * Delete unusable rates; we've already checked
         * that the negotiated rate set is acceptable.
         */
        ieee80211_fix_rate(vap->iv_bss, &vap->iv_bss->ni_rates,
                IEEE80211_F_DODEL | IEEE80211_F_JOIN);

        ieee80211_setcurchan(ic, selbs->ni_chan);
        /*
         * Set the erp state (mostly the slot time) to deal with
         * the auto-select case; this should be redundant if the
         * mode is locked.
         */ 
        ieee80211_reset_erp(ic);
        ieee80211_wme_initparams(vap);

        if (vap->iv_opmode == IEEE80211_M_STA) {
                if (canreassoc) {
                        /* Reassociate */
                        ieee80211_new_state(vap, IEEE80211_S_ASSOC, 1);
                } else {
                        /*
                         * Act as if we received a DEAUTH frame in case we
                         * are invoked from the RUN state.  This will cause
                         * us to try to re-authenticate if we are operating
                         * as a station.
                         */
                        ieee80211_new_state(vap, IEEE80211_S_AUTH,
                                IEEE80211_FC0_SUBTYPE_DEAUTH);
                }
        } else
                ieee80211_new_state(vap, IEEE80211_S_RUN, -1);
        return 1;
}

int
ieee80211_sta_join(struct ieee80211vap *vap, struct ieee80211_channel *chan,
        const struct ieee80211_scan_entry *se)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ieee80211_node *ni;

        ni = ieee80211_alloc_node(&ic->ic_sta, vap, se->se_macaddr);
        if (ni == NULL) {
                /* XXX msg */
                return 0;
        }

        /*
         * Expand scan state into node's format.
         * XXX may not need all this stuff
         */
        IEEE80211_ADDR_COPY(ni->ni_bssid, se->se_bssid);
        ni->ni_esslen = se->se_ssid[1];
        memcpy(ni->ni_essid, se->se_ssid+2, ni->ni_esslen);
        ni->ni_tstamp.tsf = se->se_tstamp.tsf;
        ni->ni_intval = se->se_intval;
        ni->ni_capinfo = se->se_capinfo;
        ni->ni_chan = chan;
        ni->ni_timoff = se->se_timoff;
        ni->ni_fhdwell = se->se_fhdwell;
        ni->ni_fhindex = se->se_fhindex;
        ni->ni_erp = se->se_erp;
        IEEE80211_RSSI_LPF(ni->ni_avgrssi, se->se_rssi);
        ni->ni_noise = se->se_noise;
        if (vap->iv_opmode == IEEE80211_M_STA) {
                /* NB: only infrastructure mode requires an associd */
                ni->ni_flags |= IEEE80211_NODE_ASSOCID;
        }

        if (ieee80211_ies_init(&ni->ni_ies, se->se_ies.data, se->se_ies.len)) {
                ieee80211_ies_expand(&ni->ni_ies);
#ifdef IEEE80211_SUPPORT_SUPERG
                if (ni->ni_ies.ath_ie != NULL)
                        ieee80211_parse_ath(ni, ni->ni_ies.ath_ie);
#endif
                if (ni->ni_ies.htcap_ie != NULL)
                        ieee80211_parse_htcap(ni, ni->ni_ies.htcap_ie);
                if (ni->ni_ies.htinfo_ie != NULL)
                        ieee80211_parse_htinfo(ni, ni->ni_ies.htinfo_ie);
#ifdef IEEE80211_SUPPORT_MESH
                if (ni->ni_ies.meshid_ie != NULL)
                        ieee80211_parse_meshid(ni, ni->ni_ies.meshid_ie);
#endif
#ifdef IEEE80211_SUPPORT_TDMA
                if (ni->ni_ies.tdma_ie != NULL)
                        ieee80211_parse_tdma(ni, ni->ni_ies.tdma_ie);
#endif
        }

        vap->iv_dtim_period = se->se_dtimperiod;
        vap->iv_dtim_count = 0;

        /* NB: must be after ni_chan is setup */
        ieee80211_setup_rates(ni, se->se_rates, se->se_xrates,
                IEEE80211_F_DOSORT);
        if (ieee80211_iserp_rateset(&ni->ni_rates))
                ni->ni_flags |= IEEE80211_NODE_ERP;

        /*
         * Setup HT state for this node if it's available, otherwise
         * non-STA modes won't pick this state up.
         *
         * For IBSS and related modes that don't go through an
         * association request/response, the only appropriate place
         * to setup the HT state is here.
         */
        if (ni->ni_ies.htinfo_ie != NULL &&
            ni->ni_ies.htcap_ie != NULL &&
            vap->iv_flags_ht & IEEE80211_FHT_HT) {
                ieee80211_ht_node_init(ni);
                ieee80211_ht_updateparams(ni,
                    ni->ni_ies.htcap_ie,
                    ni->ni_ies.htinfo_ie);
                ieee80211_setup_htrates(ni, ni->ni_ies.htcap_ie,
                    IEEE80211_F_JOIN | IEEE80211_F_DOBRS);
                ieee80211_setup_basic_htrates(ni, ni->ni_ies.htinfo_ie);
        }
        /* XXX else check for ath FF? */
        /* XXX QoS? Difficult given that WME config is specific to a master */

        ieee80211_node_setuptxparms(ni);
        ieee80211_ratectl_node_init(ni);

        return ieee80211_sta_join1(ieee80211_ref_node(ni));
}

/*
 * Leave the specified IBSS/BSS network.  The node is assumed to
 * be passed in with a held reference.
 */
void
ieee80211_sta_leave(struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;

        ic->ic_node_cleanup(ni);
        ieee80211_notify_node_leave(ni);
}

/*
 * Send a deauthenticate frame and drop the station.
 */
void
ieee80211_node_deauth(struct ieee80211_node *ni, int reason)
{
        /* NB: bump the refcnt to be sure temporay nodes are not reclaimed */
        ieee80211_ref_node(ni);
        if (ni->ni_associd != 0)
                IEEE80211_SEND_MGMT(ni, IEEE80211_FC0_SUBTYPE_DEAUTH, reason);
        ieee80211_node_leave(ni);
        ieee80211_free_node(ni);
}

static struct ieee80211_node *
node_alloc(struct ieee80211vap *vap, const uint8_t macaddr[IEEE80211_ADDR_LEN])
{
        struct ieee80211_node *ni;

        ni = (struct ieee80211_node *) malloc(sizeof(struct ieee80211_node),
                M_80211_NODE, M_NOWAIT | M_ZERO);
        return ni;
}

/*
 * Initialize an ie blob with the specified data.  If previous
 * data exists re-use the data block.  As a side effect we clear
 * all references to specific ie's; the caller is required to
 * recalculate them.
 */
int
ieee80211_ies_init(struct ieee80211_ies *ies, const uint8_t *data, int len)
{
        /* NB: assumes data+len are the last fields */
        memset(ies, 0, offsetof(struct ieee80211_ies, data));
        if (ies->data != NULL && ies->len != len) {
                /* data size changed */
                free(ies->data, M_80211_NODE_IE);
                ies->data = NULL;
        }
        if (ies->data == NULL) {
                ies->data = (uint8_t *) malloc(len, M_80211_NODE_IE, M_NOWAIT);
                if (ies->data == NULL) {
                        ies->len = 0;
                        /* NB: pointers have already been zero'd above */
                        return 0;
                }
        }
        memcpy(ies->data, data, len);
        ies->len = len;
        return 1;
}

/*
 * Reclaim storage for an ie blob.
 */
void
ieee80211_ies_cleanup(struct ieee80211_ies *ies)
{
        if (ies->data != NULL)
                free(ies->data, M_80211_NODE_IE);
}

/*
 * Expand an ie blob data contents and to fillin individual
 * ie pointers.  The data blob is assumed to be well-formed;
 * we don't do any validity checking of ie lengths.
 */
void
ieee80211_ies_expand(struct ieee80211_ies *ies)
{
        uint8_t *ie;
        int ielen;

        ie = ies->data;
        ielen = ies->len;
        while (ielen > 0) {
                switch (ie[0]) {
                case IEEE80211_ELEMID_VENDOR:
                        if (iswpaoui(ie))
                                ies->wpa_ie = ie;
                        else if (iswmeoui(ie))
                                ies->wme_ie = ie;
#ifdef IEEE80211_SUPPORT_SUPERG
                        else if (isatherosoui(ie))
                                ies->ath_ie = ie;
#endif
#ifdef IEEE80211_SUPPORT_TDMA
                        else if (istdmaoui(ie))
                                ies->tdma_ie = ie;
#endif
                        break;
                case IEEE80211_ELEMID_RSN:
                        ies->rsn_ie = ie;
                        break;
                case IEEE80211_ELEMID_HTCAP:
                        ies->htcap_ie = ie;
                        break;
                case IEEE80211_ELEMID_HTINFO:
                        ies->htinfo_ie = ie;
                        break;
#ifdef IEEE80211_SUPPORT_MESH
                case IEEE80211_ELEMID_MESHID:
                        ies->meshid_ie = ie;
                        break;
#endif
                }
                ielen -= 2 + ie[1];
                ie += 2 + ie[1];
        }
}

/*
 * Reclaim any resources in a node and reset any critical
 * state.  Typically nodes are free'd immediately after,
 * but in some cases the storage may be reused so we need
 * to insure consistent state (should probably fix that).
 */
static void
node_cleanup(struct ieee80211_node *ni)
{
#define N(a)    (sizeof(a)/sizeof(a[0]))
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211com *ic = ni->ni_ic;
        int i;

        /* NB: preserve ni_table */
        if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
                if (vap->iv_opmode != IEEE80211_M_STA)
                        vap->iv_ps_sta--;
                ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
                IEEE80211_NOTE(vap, IEEE80211_MSG_POWER, ni,
                    "power save mode off, %u sta's in ps mode", vap->iv_ps_sta);
        }
        /*
         * Cleanup any HT-related state.
         */
        if (ni->ni_flags & IEEE80211_NODE_HT)
                ieee80211_ht_node_cleanup(ni);
#ifdef IEEE80211_SUPPORT_SUPERG
        else if (ni->ni_ath_flags & IEEE80211_NODE_ATH)
                ieee80211_ff_node_cleanup(ni);
#endif
#ifdef IEEE80211_SUPPORT_MESH
        /*
         * Cleanup any mesh-related state.
         */
        if (vap->iv_opmode == IEEE80211_M_MBSS)
                ieee80211_mesh_node_cleanup(ni);
#endif
        /*
         * Clear any staging queue entries.
         */
        ieee80211_ageq_drain_node(&ic->ic_stageq, ni);

        /*
         * Clear AREF flag that marks the authorization refcnt bump
         * has happened.  This is probably not needed as the node
         * should always be removed from the table so not found but
         * do it just in case.
         * Likewise clear the ASSOCID flag as these flags are intended
         * to be managed in tandem.
         */
        ni->ni_flags &= ~(IEEE80211_NODE_AREF | IEEE80211_NODE_ASSOCID);

        /*
         * Drain power save queue and, if needed, clear TIM.
         */
        if (ieee80211_node_psq_drain(ni) != 0 && vap->iv_set_tim != NULL)
                vap->iv_set_tim(ni, 0);

        ni->ni_associd = 0;
        if (ni->ni_challenge != NULL) {
                free(ni->ni_challenge, M_80211_NODE);
                ni->ni_challenge = NULL;
        }
        /*
         * Preserve SSID, WPA, and WME ie's so the bss node is
         * reusable during a re-auth/re-assoc state transition.
         * If we remove these data they will not be recreated
         * because they come from a probe-response or beacon frame
         * which cannot be expected prior to the association-response.
         * This should not be an issue when operating in other modes
         * as stations leaving always go through a full state transition
         * which will rebuild this state.
         *
         * XXX does this leave us open to inheriting old state?
         */
        for (i = 0; i < N(ni->ni_rxfrag); i++)
                if (ni->ni_rxfrag[i] != NULL) {
                        m_freem(ni->ni_rxfrag[i]);
                        ni->ni_rxfrag[i] = NULL;
                }
        /*
         * Must be careful here to remove any key map entry w/o a LOR.
         */
        ieee80211_node_delucastkey(ni);
#undef N
}

static void
node_free(struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;

        ieee80211_ratectl_node_deinit(ni);
        ic->ic_node_cleanup(ni);
        ieee80211_ies_cleanup(&ni->ni_ies);
        ieee80211_psq_cleanup(&ni->ni_psq);
        free(ni, M_80211_NODE);
}

static void
node_age(struct ieee80211_node *ni)
{
        struct ieee80211vap *vap = ni->ni_vap;

        IEEE80211_NODE_LOCK_ASSERT(&vap->iv_ic->ic_sta);

        /*
         * Age frames on the power save queue.
         */
        if (ieee80211_node_psq_age(ni) != 0 &&
            ni->ni_psq.psq_len == 0 && vap->iv_set_tim != NULL)
                vap->iv_set_tim(ni, 0);
        /*
         * Age out HT resources (e.g. frames on the
         * A-MPDU reorder queues).
         */
        if (ni->ni_associd != 0 && (ni->ni_flags & IEEE80211_NODE_HT))
                ieee80211_ht_node_age(ni);
}

static int8_t
node_getrssi(const struct ieee80211_node *ni)
{
        uint32_t avgrssi = ni->ni_avgrssi;
        int32_t rssi;

        if (avgrssi == IEEE80211_RSSI_DUMMY_MARKER)
                return 0;
        rssi = IEEE80211_RSSI_GET(avgrssi);
        return rssi < 0 ? 0 : rssi > 127 ? 127 : rssi;
}

static void
node_getsignal(const struct ieee80211_node *ni, int8_t *rssi, int8_t *noise)
{
        *rssi = node_getrssi(ni);
        *noise = ni->ni_noise;
}

static void
node_getmimoinfo(const struct ieee80211_node *ni,
        struct ieee80211_mimo_info *info)
{
        int i;
        uint32_t avgrssi;
        int32_t rssi;

        bzero(info, sizeof(*info));

        for (i = 0; i < ni->ni_mimo_chains; i++) {
                avgrssi = ni->ni_mimo_rssi_ctl[i];
                if (avgrssi == IEEE80211_RSSI_DUMMY_MARKER) {
                        info->rssi[i] = 0;
                } else {
                        rssi = IEEE80211_RSSI_GET(avgrssi);
                        info->rssi[i] = rssi < 0 ? 0 : rssi > 127 ? 127 : rssi;
                }
                info->noise[i] = ni->ni_mimo_noise_ctl[i];
        }

        /* XXX ext radios? */

        /* XXX EVM? */
}

struct ieee80211_node *
ieee80211_alloc_node(struct ieee80211_node_table *nt,
        struct ieee80211vap *vap, const uint8_t macaddr[IEEE80211_ADDR_LEN])
{
        struct ieee80211com *ic = nt->nt_ic;
        struct ieee80211_node *ni;
        int hash;

        ni = ic->ic_node_alloc(vap, macaddr);
        if (ni == NULL) {
                vap->iv_stats.is_rx_nodealloc++;
                return NULL;
        }

        IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE,
                "%s %p<%s> in %s table\n", __func__, ni,
                ether_sprintf(macaddr), nt->nt_name);

        IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
        hash = IEEE80211_NODE_HASH(ic, macaddr);
        ieee80211_node_initref(ni);             /* mark referenced */
        ni->ni_chan = IEEE80211_CHAN_ANYC;
        ni->ni_authmode = IEEE80211_AUTH_OPEN;
        ni->ni_txpower = ic->ic_txpowlimit;     /* max power */
        ni->ni_txparms = &vap->iv_txparms[ieee80211_chan2mode(ic->ic_curchan)];
        ieee80211_crypto_resetkey(vap, &ni->ni_ucastkey, IEEE80211_KEYIX_NONE);
        ni->ni_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
        ni->ni_inact_reload = nt->nt_inact_init;
        ni->ni_inact = ni->ni_inact_reload;
        ni->ni_ath_defkeyix = 0x7fff;
        ieee80211_psq_init(&ni->ni_psq, "unknown");
#ifdef IEEE80211_SUPPORT_MESH
        if (vap->iv_opmode == IEEE80211_M_MBSS)
                ieee80211_mesh_node_init(vap, ni);
#endif
        IEEE80211_NODE_LOCK(nt);
        TAILQ_INSERT_TAIL(&nt->nt_node, ni, ni_list);
        LIST_INSERT_HEAD(&nt->nt_hash[hash], ni, ni_hash);
        ni->ni_table = nt;
        ni->ni_vap = vap;
        ni->ni_ic = ic;
        IEEE80211_NODE_UNLOCK(nt);

        IEEE80211_NOTE(vap, IEEE80211_MSG_INACT, ni,
            "%s: inact_reload %u", __func__, ni->ni_inact_reload);

        ieee80211_ratectl_node_init(ni);

        return ni;
}

/*
 * Craft a temporary node suitable for sending a management frame
 * to the specified station.  We craft only as much state as we
 * need to do the work since the node will be immediately reclaimed
 * once the send completes.
 */
struct ieee80211_node *
ieee80211_tmp_node(struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN])
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ieee80211_node *ni;

        ni = ic->ic_node_alloc(vap, macaddr);
        if (ni != NULL) {
                struct ieee80211_node *bss = vap->iv_bss;

                IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE,
                        "%s %p<%s>\n", __func__, ni, ether_sprintf(macaddr));

                ni->ni_table = NULL;            /* NB: pedantic */
                ni->ni_ic = ic;                 /* NB: needed to set channel */
                ni->ni_vap = vap;

                IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
                IEEE80211_ADDR_COPY(ni->ni_bssid, bss->ni_bssid);
                ieee80211_node_initref(ni);             /* mark referenced */
                /* NB: required by ieee80211_fix_rate */
                ieee80211_node_set_chan(ni, bss->ni_chan);
                ieee80211_crypto_resetkey(vap, &ni->ni_ucastkey,
                        IEEE80211_KEYIX_NONE);
                ni->ni_txpower = bss->ni_txpower;
                /* XXX optimize away */
                ieee80211_psq_init(&ni->ni_psq, "unknown");

                ieee80211_ratectl_node_init(ni);
        } else {
                /* XXX msg */
                vap->iv_stats.is_rx_nodealloc++;
        }
        return ni;
}

struct ieee80211_node *
ieee80211_dup_bss(struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN])
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ieee80211_node *ni;

        ni = ieee80211_alloc_node(&ic->ic_sta, vap, macaddr);
        if (ni != NULL) {
                struct ieee80211_node *bss = vap->iv_bss;
                /*
                 * Inherit from iv_bss.
                 */
                copy_bss(ni, bss);
                IEEE80211_ADDR_COPY(ni->ni_bssid, bss->ni_bssid);
                ieee80211_node_set_chan(ni, bss->ni_chan);
        }
        return ni;
}

/*
 * Create a bss node for a legacy WDS vap.  The far end does
 * not associate so we just create create a new node and
 * simulate an association.  The caller is responsible for
 * installing the node as the bss node and handling any further
 * setup work like authorizing the port.
 */
struct ieee80211_node *
ieee80211_node_create_wds(struct ieee80211vap *vap,
        const uint8_t bssid[IEEE80211_ADDR_LEN], struct ieee80211_channel *chan)
{
        struct ieee80211com *ic = vap->iv_ic;
        struct ieee80211_node *ni;

        /* XXX check if node already in sta table? */
        ni = ieee80211_alloc_node(&ic->ic_sta, vap, bssid);
        if (ni != NULL) {
                ni->ni_wdsvap = vap;
                IEEE80211_ADDR_COPY(ni->ni_bssid, bssid);
                /*
                 * Inherit any manually configured settings.
                 */
                copy_bss(ni, vap->iv_bss);
                ieee80211_node_set_chan(ni, chan);
                /* NB: propagate ssid so available to WPA supplicant */
                ni->ni_esslen = vap->iv_des_ssid[0].len;
                memcpy(ni->ni_essid, vap->iv_des_ssid[0].ssid, ni->ni_esslen);
                /* NB: no associd for peer */
                /*
                 * There are no management frames to use to
                 * discover neighbor capabilities, so blindly
                 * propagate the local configuration.
                 */
                if (vap->iv_flags & IEEE80211_F_WME)
                        ni->ni_flags |= IEEE80211_NODE_QOS;
#ifdef IEEE80211_SUPPORT_SUPERG
                if (vap->iv_flags & IEEE80211_F_FF)
                        ni->ni_flags |= IEEE80211_NODE_FF;
#endif
                if ((ic->ic_htcaps & IEEE80211_HTC_HT) &&
                    (vap->iv_flags_ht & IEEE80211_FHT_HT)) {
                        /*
                         * Device is HT-capable and HT is enabled for
                         * the vap; setup HT operation.  On return
                         * ni_chan will be adjusted to an HT channel.
                         */
                        ieee80211_ht_wds_init(ni);
                } else {
                        struct ieee80211_channel *c = ni->ni_chan;
                        /*
                         * Force a legacy channel to be used.
                         */
                        c = ieee80211_find_channel(ic,
                            c->ic_freq, c->ic_flags &~ IEEE80211_CHAN_HT);
                        KASSERT(c != NULL, ("no legacy channel, %u/%x",
                            ni->ni_chan->ic_freq, ni->ni_chan->ic_flags));
                        ni->ni_chan = c;
                }
        }
        return ni;
}

struct ieee80211_node *
#ifdef IEEE80211_DEBUG_REFCNT
ieee80211_find_node_locked_debug(struct ieee80211_node_table *nt,
        const uint8_t macaddr[IEEE80211_ADDR_LEN], const char *func, int line)
#else
ieee80211_find_node_locked(struct ieee80211_node_table *nt,
        const uint8_t macaddr[IEEE80211_ADDR_LEN])
#endif
{
        struct ieee80211_node *ni;
        int hash;

        IEEE80211_NODE_LOCK_ASSERT(nt);

        hash = IEEE80211_NODE_HASH(nt->nt_ic, macaddr);
        LIST_FOREACH(ni, &nt->nt_hash[hash], ni_hash) {
                if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) {
                        ieee80211_ref_node(ni); /* mark referenced */
#ifdef IEEE80211_DEBUG_REFCNT
                        IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_NODE,
                            "%s (%s:%u) %p<%s> refcnt %d\n", __func__,
                            func, line,
                            ni, ether_sprintf(ni->ni_macaddr),
                            ieee80211_node_refcnt(ni));
#endif
                        return ni;
                }
        }
        return NULL;
}

struct ieee80211_node *
#ifdef IEEE80211_DEBUG_REFCNT
ieee80211_find_node_debug(struct ieee80211_node_table *nt,
        const uint8_t macaddr[IEEE80211_ADDR_LEN], const char *func, int line)
#else
ieee80211_find_node(struct ieee80211_node_table *nt,
        const uint8_t macaddr[IEEE80211_ADDR_LEN])
#endif
{
        struct ieee80211_node *ni;

        IEEE80211_NODE_LOCK(nt);
        ni = ieee80211_find_node_locked(nt, macaddr);
        IEEE80211_NODE_UNLOCK(nt);
        return ni;
}

struct ieee80211_node *
#ifdef IEEE80211_DEBUG_REFCNT
ieee80211_find_vap_node_locked_debug(struct ieee80211_node_table *nt,
        const struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN], const char *func, int line)
#else
ieee80211_find_vap_node_locked(struct ieee80211_node_table *nt,
        const struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN])
#endif
{
        struct ieee80211_node *ni;
        int hash;

        IEEE80211_NODE_LOCK_ASSERT(nt);

        hash = IEEE80211_NODE_HASH(nt->nt_ic, macaddr);
        LIST_FOREACH(ni, &nt->nt_hash[hash], ni_hash) {
                if (ni->ni_vap == vap &&
                    IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) {
                        ieee80211_ref_node(ni); /* mark referenced */
#ifdef IEEE80211_DEBUG_REFCNT
                        IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_NODE,
                            "%s (%s:%u) %p<%s> refcnt %d\n", __func__,
                            func, line,
                            ni, ether_sprintf(ni->ni_macaddr),
                            ieee80211_node_refcnt(ni));
#endif
                        return ni;
                }
        }
        return NULL;
}

struct ieee80211_node *
#ifdef IEEE80211_DEBUG_REFCNT
ieee80211_find_vap_node_debug(struct ieee80211_node_table *nt,
        const struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN], const char *func, int line)
#else
ieee80211_find_vap_node(struct ieee80211_node_table *nt,
        const struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN])
#endif
{
        struct ieee80211_node *ni;

        IEEE80211_NODE_LOCK(nt);
        ni = ieee80211_find_vap_node_locked(nt, vap, macaddr);
        IEEE80211_NODE_UNLOCK(nt);
        return ni;
}

/*
 * Fake up a node; this handles node discovery in adhoc mode.
 * Note that for the driver's benefit we we treat this like
 * an association so the driver has an opportunity to setup
 * it's private state.
 */
struct ieee80211_node *
ieee80211_fakeup_adhoc_node(struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN])
{
        struct ieee80211_node *ni;

        IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE | IEEE80211_MSG_ASSOC,
            "%s: mac<%s>\n", __func__, ether_sprintf(macaddr));
        ni = ieee80211_dup_bss(vap, macaddr);
        if (ni != NULL) {
                struct ieee80211com *ic = vap->iv_ic;

                /* XXX no rate negotiation; just dup */
                ni->ni_rates = vap->iv_bss->ni_rates;
                if (ieee80211_iserp_rateset(&ni->ni_rates))
                        ni->ni_flags |= IEEE80211_NODE_ERP;
                if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
                        /*
                         * In adhoc demo mode there are no management
                         * frames to use to discover neighbor capabilities,
                         * so blindly propagate the local configuration 
                         * so we can do interesting things (e.g. use
                         * WME to disable ACK's).
                         */
                        if (vap->iv_flags & IEEE80211_F_WME)
                                ni->ni_flags |= IEEE80211_NODE_QOS;
#ifdef IEEE80211_SUPPORT_SUPERG
                        if (vap->iv_flags & IEEE80211_F_FF)
                                ni->ni_flags |= IEEE80211_NODE_FF;
#endif
                }
                ieee80211_node_setuptxparms(ni);
                ieee80211_ratectl_node_init(ni);
                if (ic->ic_newassoc != NULL)
                        ic->ic_newassoc(ni, 1);
                /* XXX not right for 802.1x/WPA */
                ieee80211_node_authorize(ni);
        }
        return ni;
}

void
ieee80211_init_neighbor(struct ieee80211_node *ni,
        const struct ieee80211_frame *wh,
        const struct ieee80211_scanparams *sp)
{
        int do_ht_setup = 0;

        ni->ni_esslen = sp->ssid[1];
        memcpy(ni->ni_essid, sp->ssid + 2, sp->ssid[1]);
        IEEE80211_ADDR_COPY(ni->ni_bssid, wh->i_addr3);
        memcpy(ni->ni_tstamp.data, sp->tstamp, sizeof(ni->ni_tstamp));
        ni->ni_intval = sp->bintval;
        ni->ni_capinfo = sp->capinfo;
        ni->ni_chan = ni->ni_ic->ic_curchan;
        ni->ni_fhdwell = sp->fhdwell;
        ni->ni_fhindex = sp->fhindex;
        ni->ni_erp = sp->erp;
        ni->ni_timoff = sp->timoff;
#ifdef IEEE80211_SUPPORT_MESH
        if (ni->ni_vap->iv_opmode == IEEE80211_M_MBSS)
                ieee80211_mesh_init_neighbor(ni, wh, sp);
#endif
        if (ieee80211_ies_init(&ni->ni_ies, sp->ies, sp->ies_len)) {
                ieee80211_ies_expand(&ni->ni_ies);
                if (ni->ni_ies.wme_ie != NULL)
                        ni->ni_flags |= IEEE80211_NODE_QOS;
                else
                        ni->ni_flags &= ~IEEE80211_NODE_QOS;
#ifdef IEEE80211_SUPPORT_SUPERG
                if (ni->ni_ies.ath_ie != NULL)
                        ieee80211_parse_ath(ni, ni->ni_ies.ath_ie);
#endif
                if (ni->ni_ies.htcap_ie != NULL)
                        ieee80211_parse_htcap(ni, ni->ni_ies.htcap_ie);
                if (ni->ni_ies.htinfo_ie != NULL)
                        ieee80211_parse_htinfo(ni, ni->ni_ies.htinfo_ie);

                if ((ni->ni_ies.htcap_ie != NULL) &&
                    (ni->ni_ies.htinfo_ie != NULL) &&
                    (ni->ni_vap->iv_flags_ht & IEEE80211_FHT_HT)) {
                        do_ht_setup = 1;
                }
        }

        /* NB: must be after ni_chan is setup */
        ieee80211_setup_rates(ni, sp->rates, sp->xrates,
                IEEE80211_F_DOSORT | IEEE80211_F_DOFRATE |
                IEEE80211_F_DONEGO | IEEE80211_F_DODEL);

        /*
         * If the neighbor is HT compatible, flip that on.
         */
        if (do_ht_setup) {
                IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_ASSOC,
                    "%s: doing HT setup\n", __func__);
                ieee80211_ht_node_init(ni);
                ieee80211_ht_updateparams(ni,
                    ni->ni_ies.htcap_ie,
                    ni->ni_ies.htinfo_ie);
                ieee80211_setup_htrates(ni,
                    ni->ni_ies.htcap_ie,
                    IEEE80211_F_JOIN | IEEE80211_F_DOBRS);
                ieee80211_setup_basic_htrates(ni,
                    ni->ni_ies.htinfo_ie);
                ieee80211_node_setuptxparms(ni);
                ieee80211_ratectl_node_init(ni);
        }
}

/*
 * Do node discovery in adhoc mode on receipt of a beacon
 * or probe response frame.  Note that for the driver's
 * benefit we we treat this like an association so the
 * driver has an opportunity to setup it's private state.
 */
struct ieee80211_node *
ieee80211_add_neighbor(struct ieee80211vap *vap,
        const struct ieee80211_frame *wh,
        const struct ieee80211_scanparams *sp)
{
        struct ieee80211_node *ni;

        IEEE80211_DPRINTF(vap, IEEE80211_MSG_ASSOC,
            "%s: mac<%s>\n", __func__, ether_sprintf(wh->i_addr2));
        ni = ieee80211_dup_bss(vap, wh->i_addr2);/* XXX alloc_node? */
        if (ni != NULL) {
                struct ieee80211com *ic = vap->iv_ic;

                ieee80211_init_neighbor(ni, wh, sp);
                if (ieee80211_iserp_rateset(&ni->ni_rates))
                        ni->ni_flags |= IEEE80211_NODE_ERP;
                ieee80211_node_setuptxparms(ni);
                ieee80211_ratectl_node_init(ni);
                if (ic->ic_newassoc != NULL)
                        ic->ic_newassoc(ni, 1);
                /* XXX not right for 802.1x/WPA */
                ieee80211_node_authorize(ni);
        }
        return ni;
}

#define IS_PROBEREQ(wh) \
        ((wh->i_fc[0] & (IEEE80211_FC0_TYPE_MASK|IEEE80211_FC0_SUBTYPE_MASK)) \
            == (IEEE80211_FC0_TYPE_MGT | IEEE80211_FC0_SUBTYPE_PROBE_REQ))
#define IS_BCAST_PROBEREQ(wh) \
        (IS_PROBEREQ(wh) && IEEE80211_IS_MULTICAST( \
            ((const struct ieee80211_frame *)(wh))->i_addr3))

static __inline struct ieee80211_node *
_find_rxnode(struct ieee80211_node_table *nt,
    const struct ieee80211_frame_min *wh)
{
        if (IS_BCAST_PROBEREQ(wh))
                return NULL;            /* spam bcast probe req to all vap's */
        return ieee80211_find_node_locked(nt, wh->i_addr2);
}

/*
 * Locate the node for sender, track state, and then pass the
 * (referenced) node up to the 802.11 layer for its use.  Note
 * we can return NULL if the sender is not in the table.
 */
struct ieee80211_node *
#ifdef IEEE80211_DEBUG_REFCNT
ieee80211_find_rxnode_debug(struct ieee80211com *ic,
        const struct ieee80211_frame_min *wh, const char *func, int line)
#else
ieee80211_find_rxnode(struct ieee80211com *ic,
        const struct ieee80211_frame_min *wh)
#endif
{
        struct ieee80211_node_table *nt;
        struct ieee80211_node *ni;

        nt = &ic->ic_sta;
        IEEE80211_NODE_LOCK(nt);
        ni = _find_rxnode(nt, wh);
        IEEE80211_NODE_UNLOCK(nt);

        return ni;
}

/*
 * Like ieee80211_find_rxnode but use the supplied h/w
 * key index as a hint to locate the node in the key
 * mapping table.  If an entry is present at the key
 * index we return it; otherwise do a normal lookup and
 * update the mapping table if the station has a unicast
 * key assigned to it.
 */
struct ieee80211_node *
#ifdef IEEE80211_DEBUG_REFCNT
ieee80211_find_rxnode_withkey_debug(struct ieee80211com *ic,
        const struct ieee80211_frame_min *wh, ieee80211_keyix keyix,
        const char *func, int line)
#else
ieee80211_find_rxnode_withkey(struct ieee80211com *ic,
        const struct ieee80211_frame_min *wh, ieee80211_keyix keyix)
#endif
{
        struct ieee80211_node_table *nt;
        struct ieee80211_node *ni;

        nt = &ic->ic_sta;
        IEEE80211_NODE_LOCK(nt);
        if (nt->nt_keyixmap != NULL && keyix < nt->nt_keyixmax)
                ni = nt->nt_keyixmap[keyix];
        else
                ni = NULL;
        if (ni == NULL) {
                ni = _find_rxnode(nt, wh);
                if (ni != NULL && nt->nt_keyixmap != NULL) {
                        /*
                         * If the station has a unicast key cache slot
                         * assigned update the key->node mapping table.
                         */
                        keyix = ni->ni_ucastkey.wk_rxkeyix;
                        /* XXX can keyixmap[keyix] != NULL? */
                        if (keyix < nt->nt_keyixmax &&
                            nt->nt_keyixmap[keyix] == NULL) {
                                IEEE80211_DPRINTF(ni->ni_vap,
                                    IEEE80211_MSG_NODE,
                                    "%s: add key map entry %p<%s> refcnt %d\n",
                                    __func__, ni, ether_sprintf(ni->ni_macaddr),
                                    ieee80211_node_refcnt(ni)+1);
                                nt->nt_keyixmap[keyix] = ieee80211_ref_node(ni);
                        }
                }
        } else {
                if (IS_BCAST_PROBEREQ(wh))
                        ni = NULL;      /* spam bcast probe req to all vap's */
                else
                        ieee80211_ref_node(ni);
        }
        IEEE80211_NODE_UNLOCK(nt);

        return ni;
}
#undef IS_BCAST_PROBEREQ
#undef IS_PROBEREQ

/*
 * Return a reference to the appropriate node for sending
 * a data frame.  This handles node discovery in adhoc networks.
 */
struct ieee80211_node *
#ifdef IEEE80211_DEBUG_REFCNT
ieee80211_find_txnode_debug(struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN],
        const char *func, int line)
#else
ieee80211_find_txnode(struct ieee80211vap *vap,
        const uint8_t macaddr[IEEE80211_ADDR_LEN])
#endif
{
        struct ieee80211_node_table *nt = &vap->iv_ic->ic_sta;
        struct ieee80211_node *ni;

        /*
         * The destination address should be in the node table
         * unless this is a multicast/broadcast frame.  We can
         * also optimize station mode operation, all frames go
         * to the bss node.
         */
        /* XXX can't hold lock across dup_bss 'cuz of recursive locking */
        IEEE80211_NODE_LOCK(nt);
        if (vap->iv_opmode == IEEE80211_M_STA ||
            vap->iv_opmode == IEEE80211_M_WDS ||
            IEEE80211_IS_MULTICAST(macaddr))
                ni = ieee80211_ref_node(vap->iv_bss);
        else
                ni = ieee80211_find_node_locked(nt, macaddr);
        IEEE80211_NODE_UNLOCK(nt);

        if (ni == NULL) {
                if (vap->iv_opmode == IEEE80211_M_IBSS ||
                    vap->iv_opmode == IEEE80211_M_AHDEMO) {
                        /*
                         * In adhoc mode cons up a node for the destination.
                         * Note that we need an additional reference for the
                         * caller to be consistent with
                         * ieee80211_find_node_locked.
                         */
                        ni = ieee80211_fakeup_adhoc_node(vap, macaddr);
                        if (ni != NULL)
                                (void) ieee80211_ref_node(ni);
                } else {
                        IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_OUTPUT, macaddr,
                            "no node, discard frame (%s)", __func__);
                        vap->iv_stats.is_tx_nonode++;
                }
        }
        return ni;
}

static void
_ieee80211_free_node(struct ieee80211_node *ni)
{
        struct ieee80211_node_table *nt = ni->ni_table;

        /*
         * NB: careful about referencing the vap as it may be
         * gone if the last reference was held by a driver.
         * We know the com will always be present so it's safe
         * to use ni_ic below to reclaim resources.
         */
#if 0
        IEEE80211_DPRINTF(vap, IEEE80211_MSG_NODE,
                "%s %p<%s> in %s table\n", __func__, ni,
                ether_sprintf(ni->ni_macaddr),
                nt != NULL ? nt->nt_name : "<gone>");
#endif
        if (ni->ni_associd != 0) {
                struct ieee80211vap *vap = ni->ni_vap;
                if (vap->iv_aid_bitmap != NULL)
                        IEEE80211_AID_CLR(vap, ni->ni_associd);
        }
        if (nt != NULL) {
                TAILQ_REMOVE(&nt->nt_node, ni, ni_list);
                LIST_REMOVE(ni, ni_hash);
        }
        ni->ni_ic->ic_node_free(ni);
}

void
#ifdef IEEE80211_DEBUG_REFCNT
ieee80211_free_node_debug(struct ieee80211_node *ni, const char *func, int line)
#else
ieee80211_free_node(struct ieee80211_node *ni)
#endif
{
        struct ieee80211_node_table *nt = ni->ni_table;

#ifdef IEEE80211_DEBUG_REFCNT
        IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_NODE,
                "%s (%s:%u) %p<%s> refcnt %d\n", __func__, func, line, ni,
                 ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni)-1);
#endif
        if (nt != NULL) {
                IEEE80211_NODE_LOCK(nt);
                if (ieee80211_node_dectestref(ni)) {
                        /*
                         * Last reference, reclaim state.
                         */
                        _ieee80211_free_node(ni);
                } else if (ieee80211_node_refcnt(ni) == 1 &&
                    nt->nt_keyixmap != NULL) {
                        ieee80211_keyix keyix;
                        /*
                         * Check for a last reference in the key mapping table.
                         */
                        keyix = ni->ni_ucastkey.wk_rxkeyix;
                        if (keyix < nt->nt_keyixmax &&
                            nt->nt_keyixmap[keyix] == ni) {
                                IEEE80211_DPRINTF(ni->ni_vap,
                                    IEEE80211_MSG_NODE,
                                    "%s: %p<%s> clear key map entry", __func__,
                                    ni, ether_sprintf(ni->ni_macaddr));
                                nt->nt_keyixmap[keyix] = NULL;
                                ieee80211_node_decref(ni); /* XXX needed? */
                                _ieee80211_free_node(ni);
                        }
                }
                IEEE80211_NODE_UNLOCK(nt);
        } else {
                if (ieee80211_node_dectestref(ni))
                        _ieee80211_free_node(ni);
        }
}

/*
 * Reclaim a unicast key and clear any key cache state.
 */
int
ieee80211_node_delucastkey(struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct ieee80211_node_table *nt = &ic->ic_sta;
        struct ieee80211_node *nikey;
        ieee80211_keyix keyix;
        int isowned, status;

        /*
         * NB: We must beware of LOR here; deleting the key
         * can cause the crypto layer to block traffic updates
         * which can generate a LOR against the node table lock;
         * grab it here and stash the key index for our use below.
         *
         * Must also beware of recursion on the node table lock.
         * When called from node_cleanup we may already have
         * the node table lock held.  Unfortunately there's no
         * way to separate out this path so we must do this
         * conditionally.
         */
        isowned = IEEE80211_NODE_IS_LOCKED(nt);
        if (!isowned)
                IEEE80211_NODE_LOCK(nt);
        nikey = NULL;
        status = 1;             /* NB: success */
        if (ni->ni_ucastkey.wk_keyix != IEEE80211_KEYIX_NONE) {
                keyix = ni->ni_ucastkey.wk_rxkeyix;
                status = ieee80211_crypto_delkey(ni->ni_vap, &ni->ni_ucastkey);
                if (nt->nt_keyixmap != NULL && keyix < nt->nt_keyixmax) {
                        nikey = nt->nt_keyixmap[keyix];
                        nt->nt_keyixmap[keyix] = NULL;
                }
        }
        if (!isowned)
                IEEE80211_NODE_UNLOCK(nt);

        if (nikey != NULL) {
                KASSERT(nikey == ni,
                        ("key map out of sync, ni %p nikey %p", ni, nikey));
                IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_NODE,
                        "%s: delete key map entry %p<%s> refcnt %d\n",
                        __func__, ni, ether_sprintf(ni->ni_macaddr),
                        ieee80211_node_refcnt(ni)-1);
                ieee80211_free_node(ni);
        }
        return status;
}

/*
 * Reclaim a node.  If this is the last reference count then
 * do the normal free work.  Otherwise remove it from the node
 * table and mark it gone by clearing the back-reference.
 */
static void
node_reclaim(struct ieee80211_node_table *nt, struct ieee80211_node *ni)
{
        ieee80211_keyix keyix;

        IEEE80211_NODE_LOCK_ASSERT(nt);

        IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_NODE,
                "%s: remove %p<%s> from %s table, refcnt %d\n",
                __func__, ni, ether_sprintf(ni->ni_macaddr),
                nt->nt_name, ieee80211_node_refcnt(ni)-1);
        /*
         * Clear any entry in the unicast key mapping table.
         * We need to do it here so rx lookups don't find it
         * in the mapping table even if it's not in the hash
         * table.  We cannot depend on the mapping table entry
         * being cleared because the node may not be free'd.
         */
        keyix = ni->ni_ucastkey.wk_rxkeyix;
        if (nt->nt_keyixmap != NULL && keyix < nt->nt_keyixmax &&
            nt->nt_keyixmap[keyix] == ni) {
                IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_NODE,
                        "%s: %p<%s> clear key map entry %u\n",
                        __func__, ni, ether_sprintf(ni->ni_macaddr), keyix);
                nt->nt_keyixmap[keyix] = NULL;
                ieee80211_node_decref(ni);      /* NB: don't need free */
        }
        if (!ieee80211_node_dectestref(ni)) {
                /*
                 * Other references are present, just remove the
                 * node from the table so it cannot be found.  When
                 * the references are dropped storage will be
                 * reclaimed.
                 */
                TAILQ_REMOVE(&nt->nt_node, ni, ni_list);
                LIST_REMOVE(ni, ni_hash);
                ni->ni_table = NULL;            /* clear reference */
        } else
                _ieee80211_free_node(ni);
}

/*
 * Node table support.
 */

static void
ieee80211_node_table_init(struct ieee80211com *ic,
        struct ieee80211_node_table *nt,
        const char *name, int inact, int keyixmax)
{
        struct ifnet *ifp = ic->ic_ifp;

        nt->nt_ic = ic;
        IEEE80211_NODE_LOCK_INIT(nt, ifp->if_xname);
        IEEE80211_NODE_ITERATE_LOCK_INIT(nt, ifp->if_xname);
        TAILQ_INIT(&nt->nt_node);
        nt->nt_name = name;
        nt->nt_scangen = 1;
        nt->nt_inact_init = inact;
        nt->nt_keyixmax = keyixmax;
        if (nt->nt_keyixmax > 0) {
                nt->nt_keyixmap = (struct ieee80211_node **) malloc(
                        keyixmax * sizeof(struct ieee80211_node *),
                        M_80211_NODE, M_NOWAIT | M_ZERO);
                if (nt->nt_keyixmap == NULL)
                        if_printf(ic->ic_ifp,
                            "Cannot allocate key index map with %u entries\n",
                            keyixmax);
        } else
                nt->nt_keyixmap = NULL;
}

static void
ieee80211_node_table_reset(struct ieee80211_node_table *nt,
        struct ieee80211vap *match)
{
        struct ieee80211_node *ni, *next;

        IEEE80211_NODE_LOCK(nt);
        TAILQ_FOREACH_SAFE(ni, &nt->nt_node, ni_list, next) {
                if (match != NULL && ni->ni_vap != match)
                        continue;
                /* XXX can this happen?  if so need's work */
                if (ni->ni_associd != 0) {
                        struct ieee80211vap *vap = ni->ni_vap;

                        if (vap->iv_auth->ia_node_leave != NULL)
                                vap->iv_auth->ia_node_leave(ni);
                        if (vap->iv_aid_bitmap != NULL)
                                IEEE80211_AID_CLR(vap, ni->ni_associd);
                }
                ni->ni_wdsvap = NULL;           /* clear reference */
                node_reclaim(nt, ni);
        }
        if (match != NULL && match->iv_opmode == IEEE80211_M_WDS) {
                /*
                 * Make a separate pass to clear references to this vap
                 * held by DWDS entries.  They will not be matched above
                 * because ni_vap will point to the ap vap but we still
                 * need to clear ni_wdsvap when the WDS vap is destroyed
                 * and/or reset.
                 */
                TAILQ_FOREACH_SAFE(ni, &nt->nt_node, ni_list, next)
                        if (ni->ni_wdsvap == match)
                                ni->ni_wdsvap = NULL;
        }
        IEEE80211_NODE_UNLOCK(nt);
}

static void
ieee80211_node_table_cleanup(struct ieee80211_node_table *nt)
{
        ieee80211_node_table_reset(nt, NULL);
        if (nt->nt_keyixmap != NULL) {
#ifdef DIAGNOSTIC
                /* XXX verify all entries are NULL */
                int i;
                for (i = 0; i < nt->nt_keyixmax; i++)
                        if (nt->nt_keyixmap[i] != NULL)
                                printf("%s: %s[%u] still active\n", __func__,
                                        nt->nt_name, i);
#endif
                free(nt->nt_keyixmap, M_80211_NODE);
                nt->nt_keyixmap = NULL;
        }
        IEEE80211_NODE_ITERATE_LOCK_DESTROY(nt);
        IEEE80211_NODE_LOCK_DESTROY(nt);
}

/*
 * Timeout inactive stations and do related housekeeping.
 * Note that we cannot hold the node lock while sending a
 * frame as this would lead to a LOR.  Instead we use a
 * generation number to mark nodes that we've scanned and
 * drop the lock and restart a scan if we have to time out
 * a node.  Since we are single-threaded by virtue of
 * controlling the inactivity timer we can be sure this will
 * process each node only once.
 */
static void
ieee80211_timeout_stations(struct ieee80211com *ic)
{
        struct ieee80211_node_table *nt = &ic->ic_sta;
        struct ieee80211vap *vap;
        struct ieee80211_node *ni;
        int gen = 0;

        IEEE80211_NODE_ITERATE_LOCK(nt);
        gen = ++nt->nt_scangen;
restart:
        IEEE80211_NODE_LOCK(nt);
        TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
                if (ni->ni_scangen == gen)      /* previously handled */
                        continue;
                ni->ni_scangen = gen;
                /*
                 * Ignore entries for which have yet to receive an
                 * authentication frame.  These are transient and
                 * will be reclaimed when the last reference to them
                 * goes away (when frame xmits complete).
                 */
                vap = ni->ni_vap;
                /*
                 * Only process stations when in RUN state.  This
                 * insures, for example, that we don't timeout an
                 * inactive station during CAC.  Note that CSA state
                 * is actually handled in ieee80211_node_timeout as
                 * it applies to more than timeout processing.
                 */
                if (vap->iv_state != IEEE80211_S_RUN)
                        continue;
                /* XXX can vap be NULL? */
                if ((vap->iv_opmode == IEEE80211_M_HOSTAP ||
                     vap->iv_opmode == IEEE80211_M_STA) &&
                    (ni->ni_flags & IEEE80211_NODE_AREF) == 0)
                        continue;
                /*
                 * Free fragment if not needed anymore
                 * (last fragment older than 1s).
                 * XXX doesn't belong here, move to node_age
                 */
                if (ni->ni_rxfrag[0] != NULL &&
                    ticks > ni->ni_rxfragstamp + hz) {
                        m_freem(ni->ni_rxfrag[0]);
                        ni->ni_rxfrag[0] = NULL;
                }
                if (ni->ni_inact > 0) {
                        ni->ni_inact--;
                        IEEE80211_NOTE(vap, IEEE80211_MSG_INACT, ni,
                            "%s: inact %u inact_reload %u nrates %u",
                            __func__, ni->ni_inact, ni->ni_inact_reload,
                            ni->ni_rates.rs_nrates);
                }
                /*
                 * Special case ourself; we may be idle for extended periods
                 * of time and regardless reclaiming our state is wrong.
                 * XXX run ic_node_age
                 */
                if (ni == vap->iv_bss)
                        continue;
                if (ni->ni_associd != 0 || 
                    (vap->iv_opmode == IEEE80211_M_IBSS ||
                     vap->iv_opmode == IEEE80211_M_AHDEMO)) {
                        /*
                         * Age/drain resources held by the station.
                         */
                        ic->ic_node_age(ni);
                        /*
                         * Probe the station before time it out.  We
                         * send a null data frame which may not be
                         * universally supported by drivers (need it
                         * for ps-poll support so it should be...).
                         *
                         * XXX don't probe the station unless we've
                         *     received a frame from them (and have
                         *     some idea of the rates they are capable
                         *     of); this will get fixed more properly
                         *     soon with better handling of the rate set.
                         */
                        if ((vap->iv_flags_ext & IEEE80211_FEXT_INACT) &&
                            (0 < ni->ni_inact &&
                             ni->ni_inact <= vap->iv_inact_probe) &&
                            ni->ni_rates.rs_nrates != 0) {
                                IEEE80211_NOTE(vap,
                                    IEEE80211_MSG_INACT | IEEE80211_MSG_NODE,
                                    ni, "%s",
                                    "probe station due to inactivity");
                                /*
                                 * Grab a reference before unlocking the table
                                 * so the node cannot be reclaimed before we
                                 * send the frame. ieee80211_send_nulldata
                                 * understands we've done this and reclaims the
                                 * ref for us as needed.
                                 */
                                ieee80211_ref_node(ni);
                                IEEE80211_NODE_UNLOCK(nt);
                                ieee80211_send_nulldata(ni);
                                /* XXX stat? */
                                goto restart;
                        }
                }
                if ((vap->iv_flags_ext & IEEE80211_FEXT_INACT) &&
                    ni->ni_inact <= 0) {
                        IEEE80211_NOTE(vap,
                            IEEE80211_MSG_INACT | IEEE80211_MSG_NODE, ni,
                            "station timed out due to inactivity "
                            "(refcnt %u)", ieee80211_node_refcnt(ni));
                        /*
                         * Send a deauthenticate frame and drop the station.
                         * This is somewhat complicated due to reference counts
                         * and locking.  At this point a station will typically
                         * have a reference count of 1.  ieee80211_node_leave
                         * will do a "free" of the node which will drop the
                         * reference count.  But in the meantime a reference
                         * wil be held by the deauth frame.  The actual reclaim
                         * of the node will happen either after the tx is
                         * completed or by ieee80211_node_leave.
                         *
                         * Separately we must drop the node lock before sending
                         * in case the driver takes a lock, as this can result
                         * in a LOR between the node lock and the driver lock.
                         */
                        ieee80211_ref_node(ni);
                        IEEE80211_NODE_UNLOCK(nt);
                        if (ni->ni_associd != 0) {
                                IEEE80211_SEND_MGMT(ni,
                                    IEEE80211_FC0_SUBTYPE_DEAUTH,
                                    IEEE80211_REASON_AUTH_EXPIRE);
                        }
                        ieee80211_node_leave(ni);
                        ieee80211_free_node(ni);
                        vap->iv_stats.is_node_timeout++;
                        goto restart;
                }
        }
        IEEE80211_NODE_UNLOCK(nt);

        IEEE80211_NODE_ITERATE_UNLOCK(nt);
}

/*
 * Aggressively reclaim resources.  This should be used
 * only in a critical situation to reclaim mbuf resources.
 */
void
ieee80211_drain(struct ieee80211com *ic)
{
        struct ieee80211_node_table *nt = &ic->ic_sta;
        struct ieee80211vap *vap;
        struct ieee80211_node *ni;

        IEEE80211_NODE_LOCK(nt);
        TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
                /*
                 * Ignore entries for which have yet to receive an
                 * authentication frame.  These are transient and
                 * will be reclaimed when the last reference to them
                 * goes away (when frame xmits complete).
                 */
                vap = ni->ni_vap;
                /*
                 * Only process stations when in RUN state.  This
                 * insures, for example, that we don't timeout an
                 * inactive station during CAC.  Note that CSA state
                 * is actually handled in ieee80211_node_timeout as
                 * it applies to more than timeout processing.
                 */
                if (vap->iv_state != IEEE80211_S_RUN)
                        continue;
                /* XXX can vap be NULL? */
                if ((vap->iv_opmode == IEEE80211_M_HOSTAP ||
                     vap->iv_opmode == IEEE80211_M_STA) &&
                    (ni->ni_flags & IEEE80211_NODE_AREF) == 0)
                        continue;
                /*
                 * Free fragments.
                 * XXX doesn't belong here, move to node_drain
                 */
                if (ni->ni_rxfrag[0] != NULL) {
                        m_freem(ni->ni_rxfrag[0]);
                        ni->ni_rxfrag[0] = NULL;
                }
                /*
                 * Drain resources held by the station.
                 */
                ic->ic_node_drain(ni);
        }
        IEEE80211_NODE_UNLOCK(nt);
}

/*
 * Per-ieee80211com inactivity timer callback.
 */
void
ieee80211_node_timeout(void *arg)
{
        struct ieee80211com *ic = arg;

        /*
         * Defer timeout processing if a channel switch is pending.
         * We typically need to be mute so not doing things that
         * might generate frames is good to handle in one place.
         * Supressing the station timeout processing may extend the
         * lifetime of inactive stations (by not decrementing their
         * idle counters) but this should be ok unless the CSA is
         * active for an unusually long time.
         */
        if ((ic->ic_flags & IEEE80211_F_CSAPENDING) == 0) {
                ieee80211_scan_timeout(ic);
                ieee80211_timeout_stations(ic);
                ieee80211_ageq_age(&ic->ic_stageq, IEEE80211_INACT_WAIT);

                IEEE80211_LOCK(ic);
                ieee80211_erp_timeout(ic);
                ieee80211_ht_timeout(ic);
                IEEE80211_UNLOCK(ic);
        }
        callout_reset(&ic->ic_inact, IEEE80211_INACT_WAIT*hz,
                ieee80211_node_timeout, ic);
}

/*
 * Iterate over the node table and return an array of ref'ed nodes.
 *
 * This is separated out from calling the actual node function so that
 * no LORs will occur.
 *
 * If there are too many nodes (ie, the number of nodes doesn't fit
 * within 'max_aid' entries) then the node references will be freed
 * and an error will be returned.
 *
 * The responsibility of allocating and freeing "ni_arr" is up to
 * the caller.
 */
int
ieee80211_iterate_nt(struct ieee80211_node_table *nt,
    struct ieee80211_node **ni_arr, uint16_t max_aid)
{
        u_int gen;
        int i, j, ret;
        struct ieee80211_node *ni;

        IEEE80211_NODE_ITERATE_LOCK(nt);
        IEEE80211_NODE_LOCK(nt);

        gen = ++nt->nt_scangen;
        i = ret = 0;

        /*
         * We simply assume here that since the node
         * scan generation doesn't change (as
         * we are holding both the node table and
         * node table iteration locks), we can simply
         * assign it to the node here.
         */
        TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
                if (i >= max_aid) {
                        ret = E2BIG;
                        if_printf(nt->nt_ic->ic_ifp,
                            "Node array overflow: max=%u", max_aid);
                        break;
                }
                ni_arr[i] = ieee80211_ref_node(ni);
                ni_arr[i]->ni_scangen = gen;
                i++;
        }

        /*
         * It's safe to unlock here.
         *
         * If we're successful, the list is returned.
         * If we're unsuccessful, the list is ignored
         * and we remove our references.
         *
         * This avoids any potential LOR with
         * ieee80211_free_node().
         */
        IEEE80211_NODE_UNLOCK(nt);
        IEEE80211_NODE_ITERATE_UNLOCK(nt);

        /*
         * If ret is non-zero, we hit some kind of error.
         * Rather than walking some nodes, we'll walk none
         * of them.
         */
        if (ret) {
                for (j = 0; j < i; j++) {
                        /* ieee80211_free_node() locks by itself */
                        ieee80211_free_node(ni_arr[j]);
                }
        }

        return (ret);
}

/*
 * Just a wrapper, so we don't have to change every ieee80211_iterate_nodes()
 * reference in the source.
 *
 * Note that this fetches 'max_aid' from the first VAP, rather than finding
 * the largest max_aid from all VAPs.
 */
void
ieee80211_iterate_nodes(struct ieee80211_node_table *nt,
        ieee80211_iter_func *f, void *arg)
{
        struct ieee80211_node **ni_arr;
        size_t size;
        int i;
        uint16_t max_aid;
        struct ieee80211vap *vap;

        /* Overdoing it default */
        max_aid = IEEE80211_AID_MAX;

        /* Handle the case of there being no vaps just yet */
        vap = TAILQ_FIRST(&nt->nt_ic->ic_vaps);
        if (vap != NULL)
                max_aid = vap->iv_max_aid;

        size = max_aid * sizeof(struct ieee80211_node *);
        ni_arr = (struct ieee80211_node **) malloc(size, M_80211_NODE,
            M_NOWAIT | M_ZERO);
        if (ni_arr == NULL)
                return;

        /*
         * If this fails, the node table won't have any
         * valid entries - ieee80211_iterate_nt() frees
         * the references to them.  So don't try walking
         * the table; just skip to the end and free the
         * temporary memory.
         */
        if (ieee80211_iterate_nt(nt, ni_arr, max_aid) != 0)
                goto done;

        for (i = 0; i < max_aid; i++) {
                if (ni_arr[i] == NULL)  /* end of the list */
                        break;
                (*f)(arg, ni_arr[i]);
                /* ieee80211_free_node() locks by itself */
                ieee80211_free_node(ni_arr[i]);
        }

done:
        free(ni_arr, M_80211_NODE);
}

void
ieee80211_dump_node(struct ieee80211_node_table *nt, struct ieee80211_node *ni)
{
        printf("0x%p: mac %s refcnt %d\n", ni,
                ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni));
        printf("\tscangen %u authmode %u flags 0x%x\n",
                ni->ni_scangen, ni->ni_authmode, ni->ni_flags);
        printf("\tassocid 0x%x txpower %u vlan %u\n",
                ni->ni_associd, ni->ni_txpower, ni->ni_vlan);
        printf("\ttxseq %u rxseq %u fragno %u rxfragstamp %u\n",
                ni->ni_txseqs[IEEE80211_NONQOS_TID],
                ni->ni_rxseqs[IEEE80211_NONQOS_TID] >> IEEE80211_SEQ_SEQ_SHIFT,
                ni->ni_rxseqs[IEEE80211_NONQOS_TID] & IEEE80211_SEQ_FRAG_MASK,
                ni->ni_rxfragstamp);
        printf("\trssi %d noise %d intval %u capinfo 0x%x\n",
                node_getrssi(ni), ni->ni_noise,
                ni->ni_intval, ni->ni_capinfo);
        printf("\tbssid %s essid \"%.*s\" channel %u:0x%x\n",
                ether_sprintf(ni->ni_bssid),
                ni->ni_esslen, ni->ni_essid,
                ni->ni_chan->ic_freq, ni->ni_chan->ic_flags);
        printf("\tinact %u inact_reload %u txrate %u\n",
                ni->ni_inact, ni->ni_inact_reload, ni->ni_txrate);
        printf("\thtcap %x htparam %x htctlchan %u ht2ndchan %u\n",
                ni->ni_htcap, ni->ni_htparam,
                ni->ni_htctlchan, ni->ni_ht2ndchan);
        printf("\thtopmode %x htstbc %x chw %u\n",
                ni->ni_htopmode, ni->ni_htstbc, ni->ni_chw);
}

void
ieee80211_dump_nodes(struct ieee80211_node_table *nt)
{
        ieee80211_iterate_nodes(nt,
                (ieee80211_iter_func *) ieee80211_dump_node, nt);
}

static void
ieee80211_notify_erp_locked(struct ieee80211com *ic)
{
        struct ieee80211vap *vap;

        IEEE80211_LOCK_ASSERT(ic);

        TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next)
                if (vap->iv_opmode == IEEE80211_M_HOSTAP)
                        ieee80211_beacon_notify(vap, IEEE80211_BEACON_ERP);
}

void
ieee80211_notify_erp(struct ieee80211com *ic)
{
        IEEE80211_LOCK(ic);
        ieee80211_notify_erp_locked(ic);
        IEEE80211_UNLOCK(ic);
}

/*
 * Handle a station joining an 11g network.
 */
static void
ieee80211_node_join_11g(struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;

        IEEE80211_LOCK_ASSERT(ic);

        /*
         * Station isn't capable of short slot time.  Bump
         * the count of long slot time stations and disable
         * use of short slot time.  Note that the actual switch
         * over to long slot time use may not occur until the
         * next beacon transmission (per sec. 7.3.1.4 of 11g).
         */
        if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) == 0) {
                ic->ic_longslotsta++;
                IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_ASSOC, ni,
                    "station needs long slot time, count %d",
                    ic->ic_longslotsta);
                /* XXX vap's w/ conflicting needs won't work */
                if (!IEEE80211_IS_CHAN_108G(ic->ic_bsschan)) {
                        /*
                         * Don't force slot time when switched to turbo
                         * mode as non-ERP stations won't be present; this
                         * need only be done when on the normal G channel.
                         */
                        ieee80211_set_shortslottime(ic, 0);
                }
        }
        /*
         * If the new station is not an ERP station
         * then bump the counter and enable protection
         * if configured.
         */
        if (!ieee80211_iserp_rateset(&ni->ni_rates)) {
                ic->ic_nonerpsta++;
                IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_ASSOC, ni,
                    "station is !ERP, %d non-ERP stations associated",
                    ic->ic_nonerpsta);
                /*
                 * If station does not support short preamble
                 * then we must enable use of Barker preamble.
                 */
                if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE) == 0) {
                        IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_ASSOC, ni,
                            "%s", "station needs long preamble");
                        ic->ic_flags |= IEEE80211_F_USEBARKER;
                        ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE;
                }
                /*
                 * If protection is configured and this is the first
                 * indication we should use protection, enable it.
                 */
                if (ic->ic_protmode != IEEE80211_PROT_NONE &&
                    ic->ic_nonerpsta == 1 &&
                    (ic->ic_flags_ext & IEEE80211_FEXT_NONERP_PR) == 0) {
                        IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_ASSOC,
                            "%s: enable use of protection\n", __func__);
                        ic->ic_flags |= IEEE80211_F_USEPROT;
                        ieee80211_notify_erp_locked(ic);
                }
        } else
                ni->ni_flags |= IEEE80211_NODE_ERP;
}

void
ieee80211_node_join(struct ieee80211_node *ni, int resp)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct ieee80211vap *vap = ni->ni_vap;
        int newassoc;

        if (ni->ni_associd == 0) {
                uint16_t aid;

                KASSERT(vap->iv_aid_bitmap != NULL, ("no aid bitmap"));
                /*
                 * It would be good to search the bitmap
                 * more efficiently, but this will do for now.
                 */
                for (aid = 1; aid < vap->iv_max_aid; aid++) {
                        if (!IEEE80211_AID_ISSET(vap, aid))
                                break;
                }
                if (aid >= vap->iv_max_aid) {
                        IEEE80211_SEND_MGMT(ni, resp, IEEE80211_STATUS_TOOMANY);
                        ieee80211_node_leave(ni);
                        return;
                }
                ni->ni_associd = aid | 0xc000;
                ni->ni_jointime = time_uptime;
                IEEE80211_LOCK(ic);
                IEEE80211_AID_SET(vap, ni->ni_associd);
                vap->iv_sta_assoc++;
                ic->ic_sta_assoc++;

                if (IEEE80211_IS_CHAN_HT(ic->ic_bsschan))
                        ieee80211_ht_node_join(ni);
                if (IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan) &&
                    IEEE80211_IS_CHAN_FULL(ic->ic_bsschan))
                        ieee80211_node_join_11g(ni);
                IEEE80211_UNLOCK(ic);

                newassoc = 1;
        } else
                newassoc = 0;

        IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG, ni,
            "station associated at aid %d: %s preamble, %s slot time%s%s%s%s%s%s%s%s",
            IEEE80211_NODE_AID(ni),
            ic->ic_flags & IEEE80211_F_SHPREAMBLE ? "short" : "long",
            ic->ic_flags & IEEE80211_F_SHSLOT ? "short" : "long",
            ic->ic_flags & IEEE80211_F_USEPROT ? ", protection" : "",
            ni->ni_flags & IEEE80211_NODE_QOS ? ", QoS" : "",
            ni->ni_flags & IEEE80211_NODE_HT ?
                (ni->ni_chw == 40 ? ", HT40" : ", HT20") : "",
            ni->ni_flags & IEEE80211_NODE_AMPDU ? " (+AMPDU)" : "",
            ni->ni_flags & IEEE80211_NODE_MIMO_RTS ? " (+SMPS-DYN)" :
                ni->ni_flags & IEEE80211_NODE_MIMO_PS ? " (+SMPS)" : "",
            ni->ni_flags & IEEE80211_NODE_RIFS ? " (+RIFS)" : "",
            IEEE80211_ATH_CAP(vap, ni, IEEE80211_NODE_FF) ?
                ", fast-frames" : "",
            IEEE80211_ATH_CAP(vap, ni, IEEE80211_NODE_TURBOP) ?
                ", turbo" : ""
        );

        ieee80211_node_setuptxparms(ni);
        ieee80211_ratectl_node_init(ni);
        /* give driver a chance to setup state like ni_txrate */
        if (ic->ic_newassoc != NULL)
                ic->ic_newassoc(ni, newassoc);
        IEEE80211_SEND_MGMT(ni, resp, IEEE80211_STATUS_SUCCESS);
        /* tell the authenticator about new station */
        if (vap->iv_auth->ia_node_join != NULL)
                vap->iv_auth->ia_node_join(ni);
        ieee80211_notify_node_join(ni,
            resp == IEEE80211_FC0_SUBTYPE_ASSOC_RESP);
}

static void
disable_protection(struct ieee80211com *ic)
{
        KASSERT(ic->ic_nonerpsta == 0 &&
            (ic->ic_flags_ext & IEEE80211_FEXT_NONERP_PR) == 0,
           ("%d non ERP stations, flags 0x%x", ic->ic_nonerpsta,
           ic->ic_flags_ext));

        ic->ic_flags &= ~IEEE80211_F_USEPROT;
        /* XXX verify mode? */
        if (ic->ic_caps & IEEE80211_C_SHPREAMBLE) {
                ic->ic_flags |= IEEE80211_F_SHPREAMBLE;
                ic->ic_flags &= ~IEEE80211_F_USEBARKER;
        }
        ieee80211_notify_erp_locked(ic);
}

/*
 * Handle a station leaving an 11g network.
 */
static void
ieee80211_node_leave_11g(struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;

        IEEE80211_LOCK_ASSERT(ic);

        KASSERT(IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan),
             ("not in 11g, bss %u:0x%x", ic->ic_bsschan->ic_freq,
              ic->ic_bsschan->ic_flags));

        /*
         * If a long slot station do the slot time bookkeeping.
         */
        if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) == 0) {
                KASSERT(ic->ic_longslotsta > 0,
                    ("bogus long slot station count %d", ic->ic_longslotsta));
                ic->ic_longslotsta--;
                IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_ASSOC, ni,
                    "long slot time station leaves, count now %d",
                    ic->ic_longslotsta);
                if (ic->ic_longslotsta == 0) {
                        /*
                         * Re-enable use of short slot time if supported
                         * and not operating in IBSS mode (per spec).
                         */
                        if ((ic->ic_caps & IEEE80211_C_SHSLOT) &&
                            ic->ic_opmode != IEEE80211_M_IBSS) {
                                IEEE80211_DPRINTF(ni->ni_vap,
                                    IEEE80211_MSG_ASSOC,
                                    "%s: re-enable use of short slot time\n",
                                    __func__);
                                ieee80211_set_shortslottime(ic, 1);
                        }
                }
        }
        /*
         * If a non-ERP station do the protection-related bookkeeping.
         */
        if ((ni->ni_flags & IEEE80211_NODE_ERP) == 0) {
                KASSERT(ic->ic_nonerpsta > 0,
                    ("bogus non-ERP station count %d", ic->ic_nonerpsta));
                ic->ic_nonerpsta--;
                IEEE80211_NOTE(ni->ni_vap, IEEE80211_MSG_ASSOC, ni,
                    "non-ERP station leaves, count now %d%s", ic->ic_nonerpsta,
                    (ic->ic_flags_ext & IEEE80211_FEXT_NONERP_PR) ?
                        " (non-ERP sta present)" : "");
                if (ic->ic_nonerpsta == 0 &&
                    (ic->ic_flags_ext & IEEE80211_FEXT_NONERP_PR) == 0) {
                        IEEE80211_DPRINTF(ni->ni_vap, IEEE80211_MSG_ASSOC,
                                "%s: disable use of protection\n", __func__);
                        disable_protection(ic);
                }
        }
}

/*
 * Time out presence of an overlapping bss with non-ERP
 * stations.  When operating in hostap mode we listen for
 * beacons from other stations and if we identify a non-ERP
 * station is present we enable protection.  To identify
 * when all non-ERP stations are gone we time out this
 * condition.
 */
static void
ieee80211_erp_timeout(struct ieee80211com *ic)
{

        IEEE80211_LOCK_ASSERT(ic);

        if ((ic->ic_flags_ext & IEEE80211_FEXT_NONERP_PR) &&
            time_after(ticks, ic->ic_lastnonerp + IEEE80211_NONERP_PRESENT_AGE)) {
#if 0
                IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC, ni,
                    "%s", "age out non-ERP sta present on channel");
#endif
                ic->ic_flags_ext &= ~IEEE80211_FEXT_NONERP_PR;
                if (ic->ic_nonerpsta == 0)
                        disable_protection(ic);
        }
}

/*
 * Handle bookkeeping for station deauthentication/disassociation
 * when operating as an ap.
 */
void
ieee80211_node_leave(struct ieee80211_node *ni)
{
        struct ieee80211com *ic = ni->ni_ic;
        struct ieee80211vap *vap = ni->ni_vap;
        struct ieee80211_node_table *nt = ni->ni_table;

        IEEE80211_NOTE(vap, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG, ni,
            "station with aid %d leaves", IEEE80211_NODE_AID(ni));

        KASSERT(vap->iv_opmode != IEEE80211_M_STA,
                ("unexpected operating mode %u", vap->iv_opmode));
        /*
         * If node wasn't previously associated all
         * we need to do is reclaim the reference.
         */
        /* XXX ibss mode bypasses 11g and notification */
        if (ni->ni_associd == 0)
                goto done;
        /*
         * Tell the authenticator the station is leaving.
         * Note that we must do this before yanking the
         * association id as the authenticator uses the
         * associd to locate it's state block.
         */
        if (vap->iv_auth->ia_node_leave != NULL)
                vap->iv_auth->ia_node_leave(ni);

        IEEE80211_LOCK(ic);
        IEEE80211_AID_CLR(vap, ni->ni_associd);
        ni->ni_associd = 0;
        vap->iv_sta_assoc--;
        ic->ic_sta_assoc--;

        if (IEEE80211_IS_CHAN_HT(ic->ic_bsschan))
                ieee80211_ht_node_leave(ni);
        if (IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan) &&
            IEEE80211_IS_CHAN_FULL(ic->ic_bsschan))
                ieee80211_node_leave_11g(ni);
        IEEE80211_UNLOCK(ic);
        /*
         * Cleanup station state.  In particular clear various
         * state that might otherwise be reused if the node
         * is reused before the reference count goes to zero
         * (and memory is reclaimed).
         */
        ieee80211_sta_leave(ni);
done:
        /*
         * Remove the node from any table it's recorded in and
         * drop the caller's reference.  Removal from the table
         * is important to insure the node is not reprocessed
         * for inactivity.
         */
        if (nt != NULL) {
                IEEE80211_NODE_LOCK(nt);
                node_reclaim(nt, ni);
                IEEE80211_NODE_UNLOCK(nt);
        } else
                ieee80211_free_node(ni);
}

struct rssiinfo {
        struct ieee80211vap *vap;
        int     rssi_samples;
        uint32_t rssi_total;
};

static void
get_hostap_rssi(void *arg, struct ieee80211_node *ni)
{
        struct rssiinfo *info = arg;
        struct ieee80211vap *vap = ni->ni_vap;
        int8_t rssi;

        if (info->vap != vap)
                return;
        /* only associated stations */
        if (ni->ni_associd == 0)
                return;
        rssi = vap->iv_ic->ic_node_getrssi(ni);
        if (rssi != 0) {
                info->rssi_samples++;
                info->rssi_total += rssi;
        }
}

static void
get_adhoc_rssi(void *arg, struct ieee80211_node *ni)
{
        struct rssiinfo *info = arg;
        struct ieee80211vap *vap = ni->ni_vap;
        int8_t rssi;

        if (info->vap != vap)
                return;
        /* only neighbors */
        /* XXX check bssid */
        if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
                return;
        rssi = vap->iv_ic->ic_node_getrssi(ni);
        if (rssi != 0) {
                info->rssi_samples++;
                info->rssi_total += rssi;
        }
}

#ifdef IEEE80211_SUPPORT_MESH
static void
get_mesh_rssi(void *arg, struct ieee80211_node *ni)
{
        struct rssiinfo *info = arg;
        struct ieee80211vap *vap = ni->ni_vap;
        int8_t rssi;

        if (info->vap != vap)
                return;
        /* only neighbors that peered successfully */
        if (ni->ni_mlstate != IEEE80211_NODE_MESH_ESTABLISHED)
                return;
        rssi = vap->iv_ic->ic_node_getrssi(ni);
        if (rssi != 0) {
                info->rssi_samples++;
                info->rssi_total += rssi;
        }
}
#endif /* IEEE80211_SUPPORT_MESH */

int8_t
ieee80211_getrssi(struct ieee80211vap *vap)
{
#define NZ(x)   ((x) == 0 ? 1 : (x))
        struct ieee80211com *ic = vap->iv_ic;
        struct rssiinfo info;

        info.rssi_total = 0;
        info.rssi_samples = 0;
        info.vap = vap;
        switch (vap->iv_opmode) {
        case IEEE80211_M_IBSS:          /* average of all ibss neighbors */
        case IEEE80211_M_AHDEMO:        /* average of all neighbors */
                ieee80211_iterate_nodes(&ic->ic_sta, get_adhoc_rssi, &info);
                break;
        case IEEE80211_M_HOSTAP:        /* average of all associated stations */
                ieee80211_iterate_nodes(&ic->ic_sta, get_hostap_rssi, &info);
                break;
#ifdef IEEE80211_SUPPORT_MESH
        case IEEE80211_M_MBSS:          /* average of all mesh neighbors */
                ieee80211_iterate_nodes(&ic->ic_sta, get_mesh_rssi, &info);
                break;
#endif
        case IEEE80211_M_MONITOR:       /* XXX */
        case IEEE80211_M_STA:           /* use stats from associated ap */
        default:
                if (vap->iv_bss != NULL)
                        info.rssi_total = ic->ic_node_getrssi(vap->iv_bss);
                info.rssi_samples = 1;
                break;
        }
        return info.rssi_total / NZ(info.rssi_samples);
#undef NZ
}

void
ieee80211_getsignal(struct ieee80211vap *vap, int8_t *rssi, int8_t *noise)
{

        if (vap->iv_bss == NULL)                /* NB: shouldn't happen */
                return;
        vap->iv_ic->ic_node_getsignal(vap->iv_bss, rssi, noise);
        /* for non-station mode return avg'd rssi accounting */
        if (vap->iv_opmode != IEEE80211_M_STA)
                *rssi = ieee80211_getrssi(vap);
}