FreeBSD/Linux Kernel Cross Reference
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: releng/8.0/sys/net80211/ieee80211_node.c 195618 2009-07-11 15:02:45Z rpaulo $");
    
    #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 <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)) {
                   /*
                    * XXX Gotta be careful here; the rate set returned by
                    * ieee80211_get_suprates is actually any HT rate
                    * set so blindly copying it will be bad.  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 inital 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);
   }
   
   /*
    * 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;
           ieee80211_node_setuptxparms(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;
   #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;
  
          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)
  {
          /* XXX zero data? */
  }
  
  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);
  
          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");
          } 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,
              "%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);
                  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)
  {
          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
          }
  
          /* 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);
  }
  
  /*
   * 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_NODE,
              "%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);
                  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);
  }
  
  void
  ieee80211_iterate_nodes(struct ieee80211_node_table *nt,
          ieee80211_iter_func *f, void *arg)
  {
          struct ieee80211_node *ni;
          u_int gen;
  
          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) {
                          ni->ni_scangen = gen;
                          (void) ieee80211_ref_node(ni);
                          IEEE80211_NODE_UNLOCK(nt);
                          (*f)(arg, ni);
                          ieee80211_free_node(ni);
                          goto restart;
                  }
          }
          IEEE80211_NODE_UNLOCK(nt);
  
          IEEE80211_NODE_ITERATE_UNLOCK(nt);
  }
  
  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);
          /* 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);
  }

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