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ieee80211_node.c revision 1.1.1.4
      1 /*-
      2  * Copyright (c) 2001 Atsushi Onoe
      3  * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting
      4  * All rights reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the author may not be used to endorse or promote products
     15  *    derived from this software without specific prior written permission.
     16  *
     17  * Alternatively, this software may be distributed under the terms of the
     18  * GNU General Public License ("GPL") version 2 as published by the Free
     19  * Software Foundation.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     22  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #include <sys/cdefs.h>
     34 __FBSDID("$FreeBSD: src/sys/net80211/ieee80211_node.c,v 1.45 2005/03/16 20:40:48 sam Exp $");
     35 
     36 #include <sys/param.h>
     37 #include <sys/systm.h>
     38 #include <sys/mbuf.h>
     39 #include <sys/malloc.h>
     40 #include <sys/kernel.h>
     41 
     42 #include <sys/socket.h>
     43 
     44 #include <net/if.h>
     45 #include <net/if_media.h>
     46 #include <net/ethernet.h>
     47 
     48 #include <net80211/ieee80211_var.h>
     49 
     50 #include <net/bpf.h>
     51 
     52 static struct ieee80211_node *node_alloc(struct ieee80211_node_table *);
     53 static void node_cleanup(struct ieee80211_node *);
     54 static void node_free(struct ieee80211_node *);
     55 static u_int8_t node_getrssi(const struct ieee80211_node *);
     56 
     57 static void ieee80211_setup_node(struct ieee80211_node_table *,
     58 		struct ieee80211_node *, const u_int8_t *);
     59 static void _ieee80211_free_node(struct ieee80211_node *);
     60 static void ieee80211_free_allnodes(struct ieee80211_node_table *);
     61 
     62 static void ieee80211_timeout_scan_candidates(struct ieee80211_node_table *);
     63 static void ieee80211_timeout_stations(struct ieee80211_node_table *);
     64 
     65 static void ieee80211_set_tim(struct ieee80211com *,
     66 		struct ieee80211_node *, int set);
     67 
     68 static void ieee80211_node_table_init(struct ieee80211com *ic,
     69 	struct ieee80211_node_table *nt, const char *name, int inact,
     70 	void (*timeout)(struct ieee80211_node_table *));
     71 static void ieee80211_node_table_cleanup(struct ieee80211_node_table *nt);
     72 
     73 MALLOC_DEFINE(M_80211_NODE, "80211node", "802.11 node state");
     74 
     75 void
     76 ieee80211_node_attach(struct ieee80211com *ic)
     77 {
     78 
     79 	ieee80211_node_table_init(ic, &ic->ic_sta, "station",
     80 		IEEE80211_INACT_INIT, ieee80211_timeout_stations);
     81 	ieee80211_node_table_init(ic, &ic->ic_scan, "scan",
     82 		IEEE80211_INACT_SCAN, ieee80211_timeout_scan_candidates);
     83 
     84 	ic->ic_node_alloc = node_alloc;
     85 	ic->ic_node_free = node_free;
     86 	ic->ic_node_cleanup = node_cleanup;
     87 	ic->ic_node_getrssi = node_getrssi;
     88 
     89 	/* default station inactivity timer setings */
     90 	ic->ic_inact_init = IEEE80211_INACT_INIT;
     91 	ic->ic_inact_auth = IEEE80211_INACT_AUTH;
     92 	ic->ic_inact_run = IEEE80211_INACT_RUN;
     93 	ic->ic_inact_probe = IEEE80211_INACT_PROBE;
     94 
     95 	/* XXX defer */
     96 	if (ic->ic_max_aid == 0)
     97 		ic->ic_max_aid = IEEE80211_AID_DEF;
     98 	else if (ic->ic_max_aid > IEEE80211_AID_MAX)
     99 		ic->ic_max_aid = IEEE80211_AID_MAX;
    100 	MALLOC(ic->ic_aid_bitmap, u_int32_t *,
    101 		howmany(ic->ic_max_aid, 32) * sizeof(u_int32_t),
    102 		M_DEVBUF, M_NOWAIT | M_ZERO);
    103 	if (ic->ic_aid_bitmap == NULL) {
    104 		/* XXX no way to recover */
    105 		printf("%s: no memory for AID bitmap!\n", __func__);
    106 		ic->ic_max_aid = 0;
    107 	}
    108 
    109 	/* XXX defer until using hostap/ibss mode */
    110 	ic->ic_tim_len = howmany(ic->ic_max_aid, 8) * sizeof(u_int8_t);
    111 	MALLOC(ic->ic_tim_bitmap, u_int8_t *, ic->ic_tim_len,
    112 		M_DEVBUF, M_NOWAIT | M_ZERO);
    113 	if (ic->ic_tim_bitmap == NULL) {
    114 		/* XXX no way to recover */
    115 		printf("%s: no memory for TIM bitmap!\n", __func__);
    116 	}
    117 	ic->ic_set_tim = ieee80211_set_tim;	/* NB: driver should override */
    118 }
    119 
    120 void
    121 ieee80211_node_lateattach(struct ieee80211com *ic)
    122 {
    123 	struct ieee80211_node *ni;
    124 	struct ieee80211_rsnparms *rsn;
    125 
    126 	ni = ieee80211_alloc_node(&ic->ic_scan, ic->ic_myaddr);
    127 	KASSERT(ni != NULL, ("unable to setup inital BSS node"));
    128 	/*
    129 	 * Setup "global settings" in the bss node so that
    130 	 * each new station automatically inherits them.
    131 	 */
    132 	rsn = &ni->ni_rsn;
    133 	/* WEP, TKIP, and AES-CCM are always supported */
    134 	rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_WEP;
    135 	rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_TKIP;
    136 	rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_AES_CCM;
    137 	if (ic->ic_caps & IEEE80211_C_AES)
    138 		rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_AES_OCB;
    139 	if (ic->ic_caps & IEEE80211_C_CKIP)
    140 		rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_CKIP;
    141 	/*
    142 	 * Default unicast cipher to WEP for 802.1x use.  If
    143 	 * WPA is enabled the management code will set these
    144 	 * values to reflect.
    145 	 */
    146 	rsn->rsn_ucastcipher = IEEE80211_CIPHER_WEP;
    147 	rsn->rsn_ucastkeylen = 104 / NBBY;
    148 	/*
    149 	 * WPA says the multicast cipher is the lowest unicast
    150 	 * cipher supported.  But we skip WEP which would
    151 	 * otherwise be used based on this criteria.
    152 	 */
    153 	rsn->rsn_mcastcipher = IEEE80211_CIPHER_TKIP;
    154 	rsn->rsn_mcastkeylen = 128 / NBBY;
    155 
    156 	/*
    157 	 * We support both WPA-PSK and 802.1x; the one used
    158 	 * is determined by the authentication mode and the
    159 	 * setting of the PSK state.
    160 	 */
    161 	rsn->rsn_keymgmtset = WPA_ASE_8021X_UNSPEC | WPA_ASE_8021X_PSK;
    162 	rsn->rsn_keymgmt = WPA_ASE_8021X_PSK;
    163 
    164 	ic->ic_bss = ieee80211_ref_node(ni);		/* hold reference */
    165 	ic->ic_auth = ieee80211_authenticator_get(ni->ni_authmode);
    166 }
    167 
    168 void
    169 ieee80211_node_detach(struct ieee80211com *ic)
    170 {
    171 
    172 	if (ic->ic_bss != NULL) {
    173 		ieee80211_free_node(ic->ic_bss);
    174 		ic->ic_bss = NULL;
    175 	}
    176 	ieee80211_node_table_cleanup(&ic->ic_scan);
    177 	ieee80211_node_table_cleanup(&ic->ic_sta);
    178 	if (ic->ic_aid_bitmap != NULL) {
    179 		FREE(ic->ic_aid_bitmap, M_DEVBUF);
    180 		ic->ic_aid_bitmap = NULL;
    181 	}
    182 	if (ic->ic_tim_bitmap != NULL) {
    183 		FREE(ic->ic_tim_bitmap, M_DEVBUF);
    184 		ic->ic_tim_bitmap = NULL;
    185 	}
    186 }
    187 
    188 /*
    189  * Port authorize/unauthorize interfaces for use by an authenticator.
    190  */
    191 
    192 void
    193 ieee80211_node_authorize(struct ieee80211com *ic, struct ieee80211_node *ni)
    194 {
    195 	ni->ni_flags |= IEEE80211_NODE_AUTH;
    196 	ni->ni_inact_reload = ic->ic_inact_run;
    197 }
    198 
    199 void
    200 ieee80211_node_unauthorize(struct ieee80211com *ic, struct ieee80211_node *ni)
    201 {
    202 	ni->ni_flags &= ~IEEE80211_NODE_AUTH;
    203 }
    204 
    205 /*
    206  * Set/change the channel.  The rate set is also updated as
    207  * to insure a consistent view by drivers.
    208  */
    209 static __inline void
    210 ieee80211_set_chan(struct ieee80211com *ic,
    211 	struct ieee80211_node *ni, struct ieee80211_channel *chan)
    212 {
    213 	ni->ni_chan = chan;
    214 	ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, chan)];
    215 }
    216 
    217 /*
    218  * AP scanning support.
    219  */
    220 
    221 #ifdef IEEE80211_DEBUG
    222 static void
    223 dump_chanlist(const u_char chans[])
    224 {
    225 	const char *sep;
    226 	int i;
    227 
    228 	sep = " ";
    229 	for (i = 0; i < IEEE80211_CHAN_MAX; i++)
    230 		if (isset(chans, i)) {
    231 			printf("%s%u", sep, i);
    232 			sep = ", ";
    233 		}
    234 }
    235 #endif /* IEEE80211_DEBUG */
    236 
    237 /*
    238  * Initialize the channel set to scan based on the
    239  * of available channels and the current PHY mode.
    240  */
    241 static void
    242 ieee80211_reset_scan(struct ieee80211com *ic)
    243 {
    244 
    245 	/* XXX ic_des_chan should be handled with ic_chan_active */
    246 	if (ic->ic_des_chan != IEEE80211_CHAN_ANYC) {
    247 		memset(ic->ic_chan_scan, 0, sizeof(ic->ic_chan_scan));
    248 		setbit(ic->ic_chan_scan,
    249 			ieee80211_chan2ieee(ic, ic->ic_des_chan));
    250 	} else
    251 		memcpy(ic->ic_chan_scan, ic->ic_chan_active,
    252 			sizeof(ic->ic_chan_active));
    253 	/* NB: hack, setup so next_scan starts with the first channel */
    254 	if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC)
    255 		ieee80211_set_chan(ic, ic->ic_bss,
    256 			&ic->ic_channels[IEEE80211_CHAN_MAX]);
    257 #ifdef IEEE80211_DEBUG
    258 	if (ieee80211_msg_scan(ic)) {
    259 		printf("%s: scan set:", __func__);
    260 		dump_chanlist(ic->ic_chan_scan);
    261 		printf(" start chan %u\n",
    262 			ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan));
    263 	}
    264 #endif /* IEEE80211_DEBUG */
    265 }
    266 
    267 /*
    268  * Begin an active scan.
    269  */
    270 void
    271 ieee80211_begin_scan(struct ieee80211com *ic, int reset)
    272 {
    273 
    274 	ic->ic_scan.nt_scangen++;
    275 	/*
    276 	 * In all but hostap mode scanning starts off in
    277 	 * an active mode before switching to passive.
    278 	 */
    279 	if (ic->ic_opmode != IEEE80211_M_HOSTAP) {
    280 		ic->ic_flags |= IEEE80211_F_ASCAN;
    281 		ic->ic_stats.is_scan_active++;
    282 	} else
    283 		ic->ic_stats.is_scan_passive++;
    284 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
    285 		"begin %s scan in %s mode, scangen %u\n",
    286 		(ic->ic_flags & IEEE80211_F_ASCAN) ?  "active" : "passive",
    287 		ieee80211_phymode_name[ic->ic_curmode], ic->ic_scan.nt_scangen);
    288 	/*
    289 	 * Clear scan state and flush any previously seen AP's.
    290 	 */
    291 	ieee80211_reset_scan(ic);
    292 	if (reset)
    293 		ieee80211_free_allnodes(&ic->ic_scan);
    294 
    295 	ic->ic_flags |= IEEE80211_F_SCAN;
    296 
    297 	/* Scan the next channel. */
    298 	ieee80211_next_scan(ic);
    299 }
    300 
    301 /*
    302  * Switch to the next channel marked for scanning.
    303  */
    304 int
    305 ieee80211_next_scan(struct ieee80211com *ic)
    306 {
    307 	struct ieee80211_channel *chan;
    308 
    309 	/*
    310 	 * Insure any previous mgt frame timeouts don't fire.
    311 	 * This assumes the driver does the right thing in
    312 	 * flushing anything queued in the driver and below.
    313 	 */
    314 	ic->ic_mgt_timer = 0;
    315 
    316 	chan = ic->ic_bss->ni_chan;
    317 	do {
    318 		if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX])
    319 			chan = &ic->ic_channels[0];
    320 		if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) {
    321 			clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan));
    322 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
    323 			    "%s: chan %d->%d\n", __func__,
    324 			    ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan),
    325 			    ieee80211_chan2ieee(ic, chan));
    326 			ieee80211_set_chan(ic, ic->ic_bss, chan);
    327 #ifdef notyet
    328 			/* XXX driver state change */
    329 			/*
    330 			 * Scan next channel. If doing an active scan
    331 			 * and the channel is not marked passive-only
    332 			 * then send a probe request.  Otherwise just
    333 			 * listen for beacons on the channel.
    334 			 */
    335 			if ((ic->ic_flags & IEEE80211_F_ASCAN) &&
    336 			    (ni->ni_chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) {
    337 				IEEE80211_SEND_MGMT(ic, ni,
    338 				    IEEE80211_FC0_SUBTYPE_PROBE_REQ, 0);
    339 			}
    340 #else
    341 			ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
    342 #endif
    343 			return 1;
    344 		}
    345 	} while (chan != ic->ic_bss->ni_chan);
    346 	ieee80211_end_scan(ic);
    347 	return 0;
    348 }
    349 
    350 static __inline void
    351 copy_bss(struct ieee80211_node *nbss, const struct ieee80211_node *obss)
    352 {
    353 	/* propagate useful state */
    354 	nbss->ni_authmode = obss->ni_authmode;
    355 	nbss->ni_txpower = obss->ni_txpower;
    356 	nbss->ni_vlan = obss->ni_vlan;
    357 	nbss->ni_rsn = obss->ni_rsn;
    358 	/* XXX statistics? */
    359 }
    360 
    361 void
    362 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan)
    363 {
    364 	struct ieee80211_node_table *nt;
    365 	struct ieee80211_node *ni;
    366 
    367 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
    368 		"%s: creating ibss\n", __func__);
    369 
    370 	/*
    371 	 * Create the station/neighbor table.  Note that for adhoc
    372 	 * mode we make the initial inactivity timer longer since
    373 	 * we create nodes only through discovery and they typically
    374 	 * are long-lived associations.
    375 	 */
    376 	nt = &ic->ic_sta;
    377 	IEEE80211_NODE_LOCK(nt);
    378 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
    379 		nt->nt_name = "station";
    380 		nt->nt_inact_init = ic->ic_inact_init;
    381 	} else {
    382 		nt->nt_name = "neighbor";
    383 		nt->nt_inact_init = ic->ic_inact_run;
    384 	}
    385 	IEEE80211_NODE_UNLOCK(nt);
    386 
    387 	ni = ieee80211_alloc_node(nt, ic->ic_myaddr);
    388 	if (ni == NULL) {
    389 		/* XXX recovery? */
    390 		return;
    391 	}
    392 	IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr);
    393 	ni->ni_esslen = ic->ic_des_esslen;
    394 	memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen);
    395 	copy_bss(ni, ic->ic_bss);
    396 	ni->ni_intval = ic->ic_lintval;
    397 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
    398 		ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
    399 	if (ic->ic_phytype == IEEE80211_T_FH) {
    400 		ni->ni_fhdwell = 200;	/* XXX */
    401 		ni->ni_fhindex = 1;
    402 	}
    403 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
    404 		ic->ic_flags |= IEEE80211_F_SIBSS;
    405 		ni->ni_capinfo |= IEEE80211_CAPINFO_IBSS;	/* XXX */
    406 		if (ic->ic_flags & IEEE80211_F_DESBSSID)
    407 			IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_des_bssid);
    408 		else
    409 			ni->ni_bssid[0] |= 0x02;	/* local bit for IBSS */
    410 	}
    411 	/*
    412 	 * Fix the channel and related attributes.
    413 	 */
    414 	ieee80211_set_chan(ic, ni, chan);
    415 	ic->ic_curmode = ieee80211_chan2mode(ic, chan);
    416 	/*
    417 	 * Do mode-specific rate setup.
    418 	 */
    419 	if (ic->ic_curmode == IEEE80211_MODE_11G) {
    420 		/*
    421 		 * Use a mixed 11b/11g rate set.
    422 		 */
    423 		ieee80211_set11gbasicrates(&ni->ni_rates, IEEE80211_MODE_11G);
    424 	} else if (ic->ic_curmode == IEEE80211_MODE_11B) {
    425 		/*
    426 		 * Force pure 11b rate set.
    427 		 */
    428 		ieee80211_set11gbasicrates(&ni->ni_rates, IEEE80211_MODE_11B);
    429 	}
    430 
    431 	(void) ieee80211_sta_join(ic, ieee80211_ref_node(ni));
    432 }
    433 
    434 void
    435 ieee80211_reset_bss(struct ieee80211com *ic)
    436 {
    437 	struct ieee80211_node *ni, *obss;
    438 
    439 	ieee80211_node_table_reset(&ic->ic_scan);
    440 	ieee80211_node_table_reset(&ic->ic_sta);
    441 
    442 	ni = ieee80211_alloc_node(&ic->ic_scan, ic->ic_myaddr);
    443 	KASSERT(ni != NULL, ("unable to setup inital BSS node"));
    444 	obss = ic->ic_bss;
    445 	ic->ic_bss = ieee80211_ref_node(ni);
    446 	if (obss != NULL) {
    447 		copy_bss(ni, obss);
    448 		ni->ni_intval = ic->ic_lintval;
    449 		ieee80211_free_node(obss);
    450 	}
    451 }
    452 
    453 static int
    454 ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni)
    455 {
    456         u_int8_t rate;
    457         int fail;
    458 
    459 	fail = 0;
    460 	if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
    461 		fail |= 0x01;
    462 	if (ic->ic_des_chan != IEEE80211_CHAN_ANYC &&
    463 	    ni->ni_chan != ic->ic_des_chan)
    464 		fail |= 0x01;
    465 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
    466 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
    467 			fail |= 0x02;
    468 	} else {
    469 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
    470 			fail |= 0x02;
    471 	}
    472 	if (ic->ic_flags & IEEE80211_F_PRIVACY) {
    473 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
    474 			fail |= 0x04;
    475 	} else {
    476 		/* XXX does this mean privacy is supported or required? */
    477 		if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
    478 			fail |= 0x04;
    479 	}
    480 	rate = ieee80211_fix_rate(ic, ni,
    481 			IEEE80211_F_DONEGO | IEEE80211_F_DOFRATE);
    482 	if (rate & IEEE80211_RATE_BASIC)
    483 		fail |= 0x08;
    484 	if (ic->ic_des_esslen != 0 &&
    485 	    (ni->ni_esslen != ic->ic_des_esslen ||
    486 	     memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0))
    487 		fail |= 0x10;
    488 	if ((ic->ic_flags & IEEE80211_F_DESBSSID) &&
    489 	    !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid))
    490 		fail |= 0x20;
    491 #ifdef IEEE80211_DEBUG
    492 	if (ieee80211_msg_scan(ic)) {
    493 		printf(" %c %s", fail ? '-' : '+',
    494 		    ether_sprintf(ni->ni_macaddr));
    495 		printf(" %s%c", ether_sprintf(ni->ni_bssid),
    496 		    fail & 0x20 ? '!' : ' ');
    497 		printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan),
    498 			fail & 0x01 ? '!' : ' ');
    499 		printf(" %+4d", ni->ni_rssi);
    500 		printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
    501 		    fail & 0x08 ? '!' : ' ');
    502 		printf(" %4s%c",
    503 		    (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
    504 		    (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
    505 		    "????",
    506 		    fail & 0x02 ? '!' : ' ');
    507 		printf(" %3s%c ",
    508 		    (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
    509 		    "wep" : "no",
    510 		    fail & 0x04 ? '!' : ' ');
    511 		ieee80211_print_essid(ni->ni_essid, ni->ni_esslen);
    512 		printf("%s\n", fail & 0x10 ? "!" : "");
    513 	}
    514 #endif
    515 	return fail;
    516 }
    517 
    518 static __inline u_int8_t
    519 maxrate(const struct ieee80211_node *ni)
    520 {
    521 	const struct ieee80211_rateset *rs = &ni->ni_rates;
    522 	/* NB: assumes rate set is sorted (happens on frame receive) */
    523 	return rs->rs_rates[rs->rs_nrates-1] & IEEE80211_RATE_VAL;
    524 }
    525 
    526 /*
    527  * Compare the capabilities of two nodes and decide which is
    528  * more desirable (return >0 if a is considered better).  Note
    529  * that we assume compatibility/usability has already been checked
    530  * so we don't need to (e.g. validate whether privacy is supported).
    531  * Used to select the best scan candidate for association in a BSS.
    532  */
    533 static int
    534 ieee80211_node_compare(struct ieee80211com *ic,
    535 		       const struct ieee80211_node *a,
    536 		       const struct ieee80211_node *b)
    537 {
    538 	u_int8_t maxa, maxb;
    539 	u_int8_t rssia, rssib;
    540 
    541 	/* privacy support preferred */
    542 	if ((a->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) &&
    543 	    (b->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
    544 		return 1;
    545 	if ((a->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0 &&
    546 	    (b->ni_capinfo & IEEE80211_CAPINFO_PRIVACY))
    547 		return -1;
    548 
    549 	rssia = ic->ic_node_getrssi(a);
    550 	rssib = ic->ic_node_getrssi(b);
    551 	if (abs(rssib - rssia) < 5) {
    552 		/* best/max rate preferred if signal level close enough XXX */
    553 		maxa = maxrate(a);
    554 		maxb = maxrate(b);
    555 		if (maxa != maxb)
    556 			return maxa - maxb;
    557 		/* XXX use freq for channel preference */
    558 		/* for now just prefer 5Ghz band to all other bands */
    559 		if (IEEE80211_IS_CHAN_5GHZ(a->ni_chan) &&
    560 		   !IEEE80211_IS_CHAN_5GHZ(b->ni_chan))
    561 			return 1;
    562 		if (!IEEE80211_IS_CHAN_5GHZ(a->ni_chan) &&
    563 		     IEEE80211_IS_CHAN_5GHZ(b->ni_chan))
    564 			return -1;
    565 	}
    566 	/* all things being equal, use signal level */
    567 	return rssia - rssib;
    568 }
    569 
    570 /*
    571  * Mark an ongoing scan stopped.
    572  */
    573 void
    574 ieee80211_cancel_scan(struct ieee80211com *ic)
    575 {
    576 
    577 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, "%s: end %s scan\n",
    578 		__func__,
    579 		(ic->ic_flags & IEEE80211_F_ASCAN) ?  "active" : "passive");
    580 
    581 	ic->ic_flags &= ~(IEEE80211_F_SCAN | IEEE80211_F_ASCAN);
    582 }
    583 
    584 /*
    585  * Complete a scan of potential channels.
    586  */
    587 void
    588 ieee80211_end_scan(struct ieee80211com *ic)
    589 {
    590 	struct ieee80211_node_table *nt = &ic->ic_scan;
    591 	struct ieee80211_node *ni, *selbs;
    592 
    593 	ieee80211_cancel_scan(ic);
    594 	ieee80211_notify_scan_done(ic);
    595 
    596 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
    597 		u_int8_t maxrssi[IEEE80211_CHAN_MAX];	/* XXX off stack? */
    598 		int i, bestchan;
    599 		u_int8_t rssi;
    600 
    601 		/*
    602 		 * The passive scan to look for existing AP's completed,
    603 		 * select a channel to camp on.  Identify the channels
    604 		 * that already have one or more AP's and try to locate
    605 		 * an unoccupied one.  If that fails, pick a channel that
    606 		 * looks to be quietest.
    607 		 */
    608 		memset(maxrssi, 0, sizeof(maxrssi));
    609 		IEEE80211_NODE_LOCK(nt);
    610 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
    611 			rssi = ic->ic_node_getrssi(ni);
    612 			i = ieee80211_chan2ieee(ic, ni->ni_chan);
    613 			if (rssi > maxrssi[i])
    614 				maxrssi[i] = rssi;
    615 		}
    616 		IEEE80211_NODE_UNLOCK(nt);
    617 		/* XXX select channel more intelligently */
    618 		bestchan = -1;
    619 		for (i = 0; i < IEEE80211_CHAN_MAX; i++)
    620 			if (isset(ic->ic_chan_active, i)) {
    621 				/*
    622 				 * If the channel is unoccupied the max rssi
    623 				 * should be zero; just take it.  Otherwise
    624 				 * track the channel with the lowest rssi and
    625 				 * use that when all channels appear occupied.
    626 				 */
    627 				if (maxrssi[i] == 0) {
    628 					bestchan = i;
    629 					break;
    630 				}
    631 				if (bestchan == -1 ||
    632 				    maxrssi[i] < maxrssi[bestchan])
    633 					bestchan = i;
    634 			}
    635 		if (bestchan != -1) {
    636 			ieee80211_create_ibss(ic, &ic->ic_channels[bestchan]);
    637 			return;
    638 		}
    639 		/* no suitable channel, should not happen */
    640 	}
    641 
    642 	/*
    643 	 * When manually sequencing the state machine; scan just once
    644 	 * regardless of whether we have a candidate or not.  The
    645 	 * controlling application is expected to setup state and
    646 	 * initiate an association.
    647 	 */
    648 	if (ic->ic_roaming == IEEE80211_ROAMING_MANUAL)
    649 		return;
    650 	/*
    651 	 * Automatic sequencing; look for a candidate and
    652 	 * if found join the network.
    653 	 */
    654 	/* NB: unlocked read should be ok */
    655 	if (TAILQ_FIRST(&nt->nt_node) == NULL) {
    656 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
    657 			"%s: no scan candidate\n", __func__);
    658   notfound:
    659 		if (ic->ic_opmode == IEEE80211_M_IBSS &&
    660 		    (ic->ic_flags & IEEE80211_F_IBSSON) &&
    661 		    ic->ic_des_esslen != 0) {
    662 			ieee80211_create_ibss(ic, ic->ic_ibss_chan);
    663 			return;
    664 		}
    665 		/*
    666 		 * Reset the list of channels to scan and start again.
    667 		 */
    668 		ieee80211_reset_scan(ic);
    669 		ic->ic_flags |= IEEE80211_F_SCAN;
    670 		ieee80211_next_scan(ic);
    671 		return;
    672 	}
    673 	selbs = NULL;
    674 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, "\t%s\n",
    675 	    "macaddr          bssid         chan  rssi rate flag  wep  essid");
    676 	IEEE80211_NODE_LOCK(nt);
    677 	TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
    678 		if (ni->ni_fails) {
    679 			/*
    680 			 * The configuration of the access points may change
    681 			 * during my scan.  So delete the entry for the AP
    682 			 * and retry to associate if there is another beacon.
    683 			 */
    684 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
    685 				"%s: skip scan candidate %s, fails %u\n",
    686 				__func__, ether_sprintf(ni->ni_macaddr),
    687 				ni->ni_fails);
    688 			ni->ni_fails++;
    689 #if 0
    690 			if (ni->ni_fails++ > 2)
    691 				ieee80211_free_node(ni);
    692 #endif
    693 			continue;
    694 		}
    695 		if (ieee80211_match_bss(ic, ni) == 0) {
    696 			if (selbs == NULL)
    697 				selbs = ni;
    698 			else if (ieee80211_node_compare(ic, ni, selbs) > 0)
    699 				selbs = ni;
    700 		}
    701 	}
    702 	if (selbs != NULL)		/* NB: grab ref while dropping lock */
    703 		(void) ieee80211_ref_node(selbs);
    704 	IEEE80211_NODE_UNLOCK(nt);
    705 	if (selbs == NULL)
    706 		goto notfound;
    707 	if (!ieee80211_sta_join(ic, selbs)) {
    708 		ieee80211_free_node(selbs);
    709 		goto notfound;
    710 	}
    711 }
    712 
    713 /*
    714  * Handle 802.11 ad hoc network merge.  The
    715  * convention, set by the Wireless Ethernet Compatibility Alliance
    716  * (WECA), is that an 802.11 station will change its BSSID to match
    717  * the "oldest" 802.11 ad hoc network, on the same channel, that
    718  * has the station's desired SSID.  The "oldest" 802.11 network
    719  * sends beacons with the greatest TSF timestamp.
    720  *
    721  * The caller is assumed to validate TSF's before attempting a merge.
    722  *
    723  * Return !0 if the BSSID changed, 0 otherwise.
    724  */
    725 int
    726 ieee80211_ibss_merge(struct ieee80211com *ic, struct ieee80211_node *ni)
    727 {
    728 
    729 	if (ni == ic->ic_bss ||
    730 	    IEEE80211_ADDR_EQ(ni->ni_bssid, ic->ic_bss->ni_bssid)) {
    731 		/* unchanged, nothing to do */
    732 		return 0;
    733 	}
    734 	if (ieee80211_match_bss(ic, ni) != 0) {	/* capabilities mismatch */
    735 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
    736 		    "%s: merge failed, capabilities mismatch\n", __func__);
    737 		ic->ic_stats.is_ibss_capmismatch++;
    738 		return 0;
    739 	}
    740 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
    741 		"%s: new bssid %s: %s preamble, %s slot time%s\n", __func__,
    742 		ether_sprintf(ni->ni_bssid),
    743 		ic->ic_flags&IEEE80211_F_SHPREAMBLE ? "short" : "long",
    744 		ic->ic_flags&IEEE80211_F_SHSLOT ? "short" : "long",
    745 		ic->ic_flags&IEEE80211_F_USEPROT ? ", protection" : ""
    746 	);
    747 	return ieee80211_sta_join(ic, ieee80211_ref_node(ni));
    748 }
    749 
    750 /*
    751  * Join the specified IBSS/BSS network.  The node is assumed to
    752  * be passed in with a held reference.
    753  */
    754 int
    755 ieee80211_sta_join(struct ieee80211com *ic, struct ieee80211_node *selbs)
    756 {
    757 	struct ieee80211_node *obss;
    758 
    759 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
    760 		struct ieee80211_node_table *nt;
    761 		/*
    762 		 * Delete unusable rates; we've already checked
    763 		 * that the negotiated rate set is acceptable.
    764 		 */
    765 		ieee80211_fix_rate(ic, selbs, IEEE80211_F_DODEL);
    766 		/*
    767 		 * Fillin the neighbor table; it will already
    768 		 * exist if we are simply switching mastership.
    769 		 * XXX ic_sta always setup so this is unnecessary?
    770 		 */
    771 		nt = &ic->ic_sta;
    772 		IEEE80211_NODE_LOCK(nt);
    773 		nt->nt_name = "neighbor";
    774 		nt->nt_inact_init = ic->ic_inact_run;
    775 		IEEE80211_NODE_UNLOCK(nt);
    776 	}
    777 
    778 	/*
    779 	 * Committed to selbs, setup state.
    780 	 */
    781 	obss = ic->ic_bss;
    782 	ic->ic_bss = selbs;		/* NB: caller assumed to bump refcnt */
    783 	if (obss != NULL)
    784 		ieee80211_free_node(obss);
    785 	/*
    786 	 * Set the erp state (mostly the slot time) to deal with
    787 	 * the auto-select case; this should be redundant if the
    788 	 * mode is locked.
    789 	 */
    790 	ic->ic_curmode = ieee80211_chan2mode(ic, selbs->ni_chan);
    791 	ieee80211_reset_erp(ic);
    792 	ieee80211_wme_initparams(ic);
    793 
    794 	if (ic->ic_opmode == IEEE80211_M_STA)
    795 		ieee80211_new_state(ic, IEEE80211_S_AUTH, -1);
    796 	else
    797 		ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
    798 	return 1;
    799 }
    800 
    801 /*
    802  * Leave the specified IBSS/BSS network.  The node is assumed to
    803  * be passed in with a held reference.
    804  */
    805 void
    806 ieee80211_sta_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
    807 {
    808 	ic->ic_node_cleanup(ni);
    809 	ieee80211_notify_node_leave(ic, ni);
    810 }
    811 
    812 static struct ieee80211_node *
    813 node_alloc(struct ieee80211_node_table *nt)
    814 {
    815 	struct ieee80211_node *ni;
    816 
    817 	MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node),
    818 		M_80211_NODE, M_NOWAIT | M_ZERO);
    819 	return ni;
    820 }
    821 
    822 /*
    823  * Reclaim any resources in a node and reset any critical
    824  * state.  Typically nodes are free'd immediately after,
    825  * but in some cases the storage may be reused so we need
    826  * to insure consistent state (should probably fix that).
    827  */
    828 static void
    829 node_cleanup(struct ieee80211_node *ni)
    830 {
    831 #define	N(a)	(sizeof(a)/sizeof(a[0]))
    832 	struct ieee80211com *ic = ni->ni_ic;
    833 	int i, qlen;
    834 
    835 	/* NB: preserve ni_table */
    836 	if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
    837 		ic->ic_ps_sta--;
    838 		ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
    839 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
    840 		    "[%s] power save mode off, %u sta's in ps mode\n",
    841 		    ether_sprintf(ni->ni_macaddr), ic->ic_ps_sta);
    842 	}
    843 
    844 	/*
    845 	 * Drain power save queue and, if needed, clear TIM.
    846 	 */
    847 	IEEE80211_NODE_SAVEQ_DRAIN(ni, qlen);
    848 	if (qlen != 0 && ic->ic_set_tim != NULL)
    849 		ic->ic_set_tim(ic, ni, 0);
    850 
    851 	ni->ni_associd = 0;
    852 	if (ni->ni_challenge != NULL) {
    853 		FREE(ni->ni_challenge, M_DEVBUF);
    854 		ni->ni_challenge = NULL;
    855 	}
    856 	/*
    857 	 * Preserve SSID, WPA, and WME ie's so the bss node is
    858 	 * reusable during a re-auth/re-assoc state transition.
    859 	 * If we remove these data they will not be recreated
    860 	 * because they come from a probe-response or beacon frame
    861 	 * which cannot be expected prior to the association-response.
    862 	 * This should not be an issue when operating in other modes
    863 	 * as stations leaving always go through a full state transition
    864 	 * which will rebuild this state.
    865 	 *
    866 	 * XXX does this leave us open to inheriting old state?
    867 	 */
    868 	for (i = 0; i < N(ni->ni_rxfrag); i++)
    869 		if (ni->ni_rxfrag[i] != NULL) {
    870 			m_freem(ni->ni_rxfrag[i]);
    871 			ni->ni_rxfrag[i] = NULL;
    872 		}
    873 	ieee80211_crypto_delkey(ic, &ni->ni_ucastkey);
    874 #undef N
    875 }
    876 
    877 static void
    878 node_free(struct ieee80211_node *ni)
    879 {
    880 	struct ieee80211com *ic = ni->ni_ic;
    881 
    882 	ic->ic_node_cleanup(ni);
    883 	if (ni->ni_wpa_ie != NULL)
    884 		FREE(ni->ni_wpa_ie, M_DEVBUF);
    885 	if (ni->ni_wme_ie != NULL)
    886 		FREE(ni->ni_wme_ie, M_DEVBUF);
    887 	IEEE80211_NODE_SAVEQ_DESTROY(ni);
    888 	FREE(ni, M_80211_NODE);
    889 }
    890 
    891 static u_int8_t
    892 node_getrssi(const struct ieee80211_node *ni)
    893 {
    894 	return ni->ni_rssi;
    895 }
    896 
    897 static void
    898 ieee80211_setup_node(struct ieee80211_node_table *nt,
    899 	struct ieee80211_node *ni, const u_int8_t *macaddr)
    900 {
    901 	struct ieee80211com *ic = nt->nt_ic;
    902 	int hash;
    903 
    904 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
    905 		"%s %p<%s> in %s table\n", __func__, ni,
    906 		ether_sprintf(macaddr), nt->nt_name);
    907 
    908 	IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
    909 	hash = IEEE80211_NODE_HASH(macaddr);
    910 	ieee80211_node_initref(ni);		/* mark referenced */
    911 	ni->ni_chan = IEEE80211_CHAN_ANYC;
    912 	ni->ni_authmode = IEEE80211_AUTH_OPEN;
    913 	ni->ni_txpower = ic->ic_txpowlimit;	/* max power */
    914 	ieee80211_crypto_resetkey(ic, &ni->ni_ucastkey, IEEE80211_KEYIX_NONE);
    915 	ni->ni_inact_reload = nt->nt_inact_init;
    916 	ni->ni_inact = ni->ni_inact_reload;
    917 	IEEE80211_NODE_SAVEQ_INIT(ni, "unknown");
    918 
    919 	IEEE80211_NODE_LOCK(nt);
    920 	TAILQ_INSERT_TAIL(&nt->nt_node, ni, ni_list);
    921 	LIST_INSERT_HEAD(&nt->nt_hash[hash], ni, ni_hash);
    922 	ni->ni_table = nt;
    923 	ni->ni_ic = ic;
    924 	IEEE80211_NODE_UNLOCK(nt);
    925 }
    926 
    927 struct ieee80211_node *
    928 ieee80211_alloc_node(struct ieee80211_node_table *nt, const u_int8_t *macaddr)
    929 {
    930 	struct ieee80211com *ic = nt->nt_ic;
    931 	struct ieee80211_node *ni;
    932 
    933 	ni = ic->ic_node_alloc(nt);
    934 	if (ni != NULL)
    935 		ieee80211_setup_node(nt, ni, macaddr);
    936 	else
    937 		ic->ic_stats.is_rx_nodealloc++;
    938 	return ni;
    939 }
    940 
    941 struct ieee80211_node *
    942 ieee80211_dup_bss(struct ieee80211_node_table *nt, const u_int8_t *macaddr)
    943 {
    944 	struct ieee80211com *ic = nt->nt_ic;
    945 	struct ieee80211_node *ni;
    946 
    947 	ni = ic->ic_node_alloc(nt);
    948 	if (ni != NULL) {
    949 		ieee80211_setup_node(nt, ni, macaddr);
    950 		/*
    951 		 * Inherit from ic_bss.
    952 		 */
    953 		ni->ni_authmode = ic->ic_bss->ni_authmode;
    954 		ni->ni_txpower = ic->ic_bss->ni_txpower;
    955 		ni->ni_vlan = ic->ic_bss->ni_vlan;	/* XXX?? */
    956 		IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid);
    957 		ieee80211_set_chan(ic, ni, ic->ic_bss->ni_chan);
    958 		ni->ni_rsn = ic->ic_bss->ni_rsn;
    959 	} else
    960 		ic->ic_stats.is_rx_nodealloc++;
    961 	return ni;
    962 }
    963 
    964 static struct ieee80211_node *
    965 #ifdef IEEE80211_DEBUG_REFCNT
    966 _ieee80211_find_node_debug(struct ieee80211_node_table *nt,
    967 	const u_int8_t *macaddr, const char *func, int line)
    968 #else
    969 _ieee80211_find_node(struct ieee80211_node_table *nt,
    970 	const u_int8_t *macaddr)
    971 #endif
    972 {
    973 	struct ieee80211_node *ni;
    974 	int hash;
    975 
    976 	IEEE80211_NODE_LOCK_ASSERT(nt);
    977 
    978 	hash = IEEE80211_NODE_HASH(macaddr);
    979 	LIST_FOREACH(ni, &nt->nt_hash[hash], ni_hash) {
    980 		if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) {
    981 			ieee80211_ref_node(ni);	/* mark referenced */
    982 #ifdef IEEE80211_DEBUG_REFCNT
    983 			IEEE80211_DPRINTF(nt->nt_ic, IEEE80211_MSG_NODE,
    984 			    "%s (%s:%u) %p<%s> refcnt %d\n", __func__,
    985 			    func, line,
    986 			    ni, ether_sprintf(ni->ni_macaddr),
    987 			    ieee80211_node_refcnt(ni));
    988 #endif
    989 			return ni;
    990 		}
    991 	}
    992 	return NULL;
    993 }
    994 #ifdef IEEE80211_DEBUG_REFCNT
    995 #define	_ieee80211_find_node(nt, mac) \
    996 	_ieee80211_find_node_debug(nt, mac, func, line)
    997 #endif
    998 
    999 struct ieee80211_node *
   1000 #ifdef IEEE80211_DEBUG_REFCNT
   1001 ieee80211_find_node_debug(struct ieee80211_node_table *nt,
   1002 	const u_int8_t *macaddr, const char *func, int line)
   1003 #else
   1004 ieee80211_find_node(struct ieee80211_node_table *nt, const u_int8_t *macaddr)
   1005 #endif
   1006 {
   1007 	struct ieee80211_node *ni;
   1008 
   1009 	IEEE80211_NODE_LOCK(nt);
   1010 	ni = _ieee80211_find_node(nt, macaddr);
   1011 	IEEE80211_NODE_UNLOCK(nt);
   1012 	return ni;
   1013 }
   1014 
   1015 /*
   1016  * Fake up a node; this handles node discovery in adhoc mode.
   1017  * Note that for the driver's benefit we we treat this like
   1018  * an association so the driver has an opportunity to setup
   1019  * it's private state.
   1020  */
   1021 struct ieee80211_node *
   1022 ieee80211_fakeup_adhoc_node(struct ieee80211_node_table *nt,
   1023 	const u_int8_t macaddr[IEEE80211_ADDR_LEN])
   1024 {
   1025 	struct ieee80211com *ic = nt->nt_ic;
   1026 	struct ieee80211_node *ni;
   1027 
   1028 	ni = ieee80211_dup_bss(nt, macaddr);
   1029 	if (ni != NULL) {
   1030 		/* XXX no rate negotiation; just dup */
   1031 		ni->ni_rates = ic->ic_bss->ni_rates;
   1032 		if (ic->ic_newassoc != NULL)
   1033 			ic->ic_newassoc(ic, ni, 1);
   1034 		/* XXX not right for 802.1x/WPA */
   1035 		ieee80211_node_authorize(ic, ni);
   1036 	}
   1037 	return ni;
   1038 }
   1039 
   1040 /*
   1041  * Locate the node for sender, track state, and then pass the
   1042  * (referenced) node up to the 802.11 layer for its use.  We
   1043  * are required to pass some node so we fall back to ic_bss
   1044  * when this frame is from an unknown sender.  The 802.11 layer
   1045  * knows this means the sender wasn't in the node table and
   1046  * acts accordingly.
   1047  */
   1048 struct ieee80211_node *
   1049 #ifdef IEEE80211_DEBUG_REFCNT
   1050 ieee80211_find_rxnode_debug(struct ieee80211com *ic,
   1051 	const struct ieee80211_frame_min *wh, const char *func, int line)
   1052 #else
   1053 ieee80211_find_rxnode(struct ieee80211com *ic,
   1054 	const struct ieee80211_frame_min *wh)
   1055 #endif
   1056 {
   1057 #define	IS_CTL(wh) \
   1058 	((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
   1059 #define	IS_PSPOLL(wh) \
   1060 	((wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == IEEE80211_FC0_SUBTYPE_PS_POLL)
   1061 	struct ieee80211_node_table *nt;
   1062 	struct ieee80211_node *ni;
   1063 
   1064 	/* XXX may want scanned nodes in the neighbor table for adhoc */
   1065 	if (ic->ic_opmode == IEEE80211_M_STA ||
   1066 	    ic->ic_opmode == IEEE80211_M_MONITOR ||
   1067 	    (ic->ic_flags & IEEE80211_F_SCAN))
   1068 		nt = &ic->ic_scan;
   1069 	else
   1070 		nt = &ic->ic_sta;
   1071 	/* XXX check ic_bss first in station mode */
   1072 	/* XXX 4-address frames? */
   1073 	IEEE80211_NODE_LOCK(nt);
   1074 	if (IS_CTL(wh) && !IS_PSPOLL(wh) /*&& !IS_RTS(ah)*/)
   1075 		ni = _ieee80211_find_node(nt, wh->i_addr1);
   1076 	else
   1077 		ni = _ieee80211_find_node(nt, wh->i_addr2);
   1078 	IEEE80211_NODE_UNLOCK(nt);
   1079 
   1080 	return (ni != NULL ? ni : ieee80211_ref_node(ic->ic_bss));
   1081 #undef IS_PSPOLL
   1082 #undef IS_CTL
   1083 }
   1084 
   1085 /*
   1086  * Return a reference to the appropriate node for sending
   1087  * a data frame.  This handles node discovery in adhoc networks.
   1088  */
   1089 struct ieee80211_node *
   1090 #ifdef IEEE80211_DEBUG_REFCNT
   1091 ieee80211_find_txnode_debug(struct ieee80211com *ic, const u_int8_t *macaddr,
   1092 	const char *func, int line)
   1093 #else
   1094 ieee80211_find_txnode(struct ieee80211com *ic, const u_int8_t *macaddr)
   1095 #endif
   1096 {
   1097 	struct ieee80211_node_table *nt = &ic->ic_sta;
   1098 	struct ieee80211_node *ni;
   1099 
   1100 	/*
   1101 	 * The destination address should be in the node table
   1102 	 * unless we are operating in station mode or this is a
   1103 	 * multicast/broadcast frame.
   1104 	 */
   1105 	if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr))
   1106 		return ieee80211_ref_node(ic->ic_bss);
   1107 
   1108 	/* XXX can't hold lock across dup_bss 'cuz of recursive locking */
   1109 	IEEE80211_NODE_LOCK(nt);
   1110 	ni = _ieee80211_find_node(nt, macaddr);
   1111 	IEEE80211_NODE_UNLOCK(nt);
   1112 
   1113 	if (ni == NULL) {
   1114 		if (ic->ic_opmode == IEEE80211_M_IBSS ||
   1115 		    ic->ic_opmode == IEEE80211_M_AHDEMO) {
   1116 			/*
   1117 			 * In adhoc mode cons up a node for the destination.
   1118 			 * Note that we need an additional reference for the
   1119 			 * caller to be consistent with _ieee80211_find_node.
   1120 			 */
   1121 			ni = ieee80211_fakeup_adhoc_node(nt, macaddr);
   1122 			if (ni != NULL)
   1123 				(void) ieee80211_ref_node(ni);
   1124 		} else {
   1125 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
   1126 				"[%s] no node, discard frame (%s)\n",
   1127 				ether_sprintf(macaddr), __func__);
   1128 			ic->ic_stats.is_tx_nonode++;
   1129 		}
   1130 	}
   1131 	return ni;
   1132 }
   1133 
   1134 /*
   1135  * Like find but search based on the channel too.
   1136  */
   1137 struct ieee80211_node *
   1138 #ifdef IEEE80211_DEBUG_REFCNT
   1139 ieee80211_find_node_with_channel_debug(struct ieee80211_node_table *nt,
   1140 	const u_int8_t *macaddr, struct ieee80211_channel *chan,
   1141 	const char *func, int line)
   1142 #else
   1143 ieee80211_find_node_with_channel(struct ieee80211_node_table *nt,
   1144 	const u_int8_t *macaddr, struct ieee80211_channel *chan)
   1145 #endif
   1146 {
   1147 	struct ieee80211_node *ni;
   1148 	int hash;
   1149 
   1150 	hash = IEEE80211_NODE_HASH(macaddr);
   1151 	IEEE80211_NODE_LOCK(nt);
   1152 	LIST_FOREACH(ni, &nt->nt_hash[hash], ni_hash) {
   1153 		if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) &&
   1154 		    ni->ni_chan == chan) {
   1155 			ieee80211_ref_node(ni);		/* mark referenced */
   1156 			IEEE80211_DPRINTF(nt->nt_ic, IEEE80211_MSG_NODE,
   1157 #ifdef IEEE80211_DEBUG_REFCNT
   1158 			    "%s (%s:%u) %p<%s> refcnt %d\n", __func__,
   1159 			    func, line,
   1160 #else
   1161 			    "%s %p<%s> refcnt %d\n", __func__,
   1162 #endif
   1163 			    ni, ether_sprintf(ni->ni_macaddr),
   1164 			    ieee80211_node_refcnt(ni));
   1165 			break;
   1166 		}
   1167 	}
   1168 	IEEE80211_NODE_UNLOCK(nt);
   1169 	return ni;
   1170 }
   1171 
   1172 /*
   1173  * Like find but search based on the ssid too.
   1174  */
   1175 struct ieee80211_node *
   1176 #ifdef IEEE80211_DEBUG_REFCNT
   1177 ieee80211_find_node_with_ssid_debug(struct ieee80211_node_table *nt,
   1178 	const u_int8_t *macaddr, u_int ssidlen, const u_int8_t *ssid,
   1179 	const char *func, int line)
   1180 #else
   1181 ieee80211_find_node_with_ssid(struct ieee80211_node_table *nt,
   1182 	const u_int8_t *macaddr, u_int ssidlen, const u_int8_t *ssid)
   1183 #endif
   1184 {
   1185 	struct ieee80211com *ic = nt->nt_ic;
   1186 	struct ieee80211_node *ni;
   1187 	int hash;
   1188 
   1189 	hash = IEEE80211_NODE_HASH(macaddr);
   1190 	IEEE80211_NODE_LOCK(nt);
   1191 	LIST_FOREACH(ni, &nt->nt_hash[hash], ni_hash) {
   1192 		if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) &&
   1193 		    ni->ni_esslen == ic->ic_des_esslen &&
   1194 		    memcmp(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen) == 0) {
   1195 			ieee80211_ref_node(ni);		/* mark referenced */
   1196 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
   1197 #ifdef IEEE80211_DEBUG_REFCNT
   1198 			    "%s (%s:%u) %p<%s> refcnt %d\n", __func__,
   1199 			    func, line,
   1200 #else
   1201 			    "%s %p<%s> refcnt %d\n", __func__,
   1202 #endif
   1203 			     ni, ether_sprintf(ni->ni_macaddr),
   1204 			     ieee80211_node_refcnt(ni));
   1205 			break;
   1206 		}
   1207 	}
   1208 	IEEE80211_NODE_UNLOCK(nt);
   1209 	return ni;
   1210 }
   1211 
   1212 static void
   1213 _ieee80211_free_node(struct ieee80211_node *ni)
   1214 {
   1215 	struct ieee80211com *ic = ni->ni_ic;
   1216 	struct ieee80211_node_table *nt = ni->ni_table;
   1217 
   1218 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
   1219 		"%s %p<%s> in %s table\n", __func__, ni,
   1220 		ether_sprintf(ni->ni_macaddr),
   1221 		nt != NULL ? nt->nt_name : "<gone>");
   1222 
   1223 	IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
   1224 	if (nt != NULL) {
   1225 		TAILQ_REMOVE(&nt->nt_node, ni, ni_list);
   1226 		LIST_REMOVE(ni, ni_hash);
   1227 	}
   1228 	ic->ic_node_free(ni);
   1229 }
   1230 
   1231 void
   1232 #ifdef IEEE80211_DEBUG_REFCNT
   1233 ieee80211_free_node_debug(struct ieee80211_node *ni, const char *func, int line)
   1234 #else
   1235 ieee80211_free_node(struct ieee80211_node *ni)
   1236 #endif
   1237 {
   1238 	struct ieee80211_node_table *nt = ni->ni_table;
   1239 
   1240 #ifdef IEEE80211_DEBUG_REFCNT
   1241 	IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_NODE,
   1242 		"%s (%s:%u) %p<%s> refcnt %d\n", __func__, func, line, ni,
   1243 		 ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni)-1);
   1244 #endif
   1245 	if (ieee80211_node_dectestref(ni)) {
   1246 		/*
   1247 		 * Beware; if the node is marked gone then it's already
   1248 		 * been removed from the table and we cannot assume the
   1249 		 * table still exists.  Regardless, there's no need to lock
   1250 		 * the table.
   1251 		 */
   1252 		if (ni->ni_table != NULL) {
   1253 			IEEE80211_NODE_LOCK(nt);
   1254 			_ieee80211_free_node(ni);
   1255 			IEEE80211_NODE_UNLOCK(nt);
   1256 		} else
   1257 			_ieee80211_free_node(ni);
   1258 	}
   1259 }
   1260 
   1261 /*
   1262  * Reclaim a node.  If this is the last reference count then
   1263  * do the normal free work.  Otherwise remove it from the node
   1264  * table and mark it gone by clearing the back-reference.
   1265  */
   1266 static void
   1267 node_reclaim(struct ieee80211_node_table *nt, struct ieee80211_node *ni)
   1268 {
   1269 
   1270 	IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_NODE,
   1271 		"%s: remove %p<%s> from %s table, refcnt %d\n",
   1272 		__func__, ni, ether_sprintf(ni->ni_macaddr),
   1273 		nt->nt_name, ieee80211_node_refcnt(ni)-1);
   1274 	if (!ieee80211_node_dectestref(ni)) {
   1275 		/*
   1276 		 * Other references are present, just remove the
   1277 		 * node from the table so it cannot be found.  When
   1278 		 * the references are dropped storage will be
   1279 		 * reclaimed.
   1280 		 */
   1281 		TAILQ_REMOVE(&nt->nt_node, ni, ni_list);
   1282 		LIST_REMOVE(ni, ni_hash);
   1283 		ni->ni_table = NULL;		/* clear reference */
   1284 	} else
   1285 		_ieee80211_free_node(ni);
   1286 }
   1287 
   1288 static void
   1289 ieee80211_free_allnodes_locked(struct ieee80211_node_table *nt)
   1290 {
   1291 	struct ieee80211com *ic = nt->nt_ic;
   1292 	struct ieee80211_node *ni;
   1293 
   1294 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
   1295 		"%s: free all nodes in %s table\n", __func__, nt->nt_name);
   1296 
   1297 	while ((ni = TAILQ_FIRST(&nt->nt_node)) != NULL) {
   1298 		if (ni->ni_associd != 0) {
   1299 			if (ic->ic_auth->ia_node_leave != NULL)
   1300 				ic->ic_auth->ia_node_leave(ic, ni);
   1301 			IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
   1302 		}
   1303 		node_reclaim(nt, ni);
   1304 	}
   1305 	ieee80211_reset_erp(ic);
   1306 }
   1307 
   1308 static void
   1309 ieee80211_free_allnodes(struct ieee80211_node_table *nt)
   1310 {
   1311 
   1312 	IEEE80211_NODE_LOCK(nt);
   1313 	ieee80211_free_allnodes_locked(nt);
   1314 	IEEE80211_NODE_UNLOCK(nt);
   1315 }
   1316 
   1317 /*
   1318  * Timeout entries in the scan cache.
   1319  */
   1320 static void
   1321 ieee80211_timeout_scan_candidates(struct ieee80211_node_table *nt)
   1322 {
   1323 	struct ieee80211com *ic = nt->nt_ic;
   1324 	struct ieee80211_node *ni, *tni;
   1325 
   1326 	IEEE80211_NODE_LOCK(nt);
   1327 	ni = ic->ic_bss;
   1328 	/* XXX belongs elsewhere */
   1329 	if (ni->ni_rxfrag[0] != NULL && ticks > ni->ni_rxfragstamp + hz) {
   1330 		m_freem(ni->ni_rxfrag[0]);
   1331 		ni->ni_rxfrag[0] = NULL;
   1332 	}
   1333 	TAILQ_FOREACH_SAFE(ni, &nt->nt_node, ni_list, tni) {
   1334 		if (ni->ni_inact && --ni->ni_inact == 0) {
   1335 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
   1336 			    "[%s] scan candidate purged from cache "
   1337 			    "(refcnt %u)\n", ether_sprintf(ni->ni_macaddr),
   1338 			    ieee80211_node_refcnt(ni));
   1339 			node_reclaim(nt, ni);
   1340 		}
   1341 	}
   1342 	IEEE80211_NODE_UNLOCK(nt);
   1343 
   1344 	nt->nt_inact_timer = IEEE80211_INACT_WAIT;
   1345 }
   1346 
   1347 /*
   1348  * Timeout inactive stations and do related housekeeping.
   1349  * Note that we cannot hold the node lock while sending a
   1350  * frame as this would lead to a LOR.  Instead we use a
   1351  * generation number to mark nodes that we've scanned and
   1352  * drop the lock and restart a scan if we have to time out
   1353  * a node.  Since we are single-threaded by virtue of
   1354  * controlling the inactivity timer we can be sure this will
   1355  * process each node only once.
   1356  */
   1357 static void
   1358 ieee80211_timeout_stations(struct ieee80211_node_table *nt)
   1359 {
   1360 	struct ieee80211com *ic = nt->nt_ic;
   1361 	struct ieee80211_node *ni;
   1362 	u_int gen;
   1363 
   1364 	IEEE80211_SCAN_LOCK(nt);
   1365 	gen = nt->nt_scangen++;
   1366 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
   1367 		"%s: %s scangen %u\n", __func__, nt->nt_name, gen);
   1368 restart:
   1369 	IEEE80211_NODE_LOCK(nt);
   1370 	TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
   1371 		if (ni->ni_scangen == gen)	/* previously handled */
   1372 			continue;
   1373 		ni->ni_scangen = gen;
   1374 		/*
   1375 		 * Free fragment if not needed anymore
   1376 		 * (last fragment older than 1s).
   1377 		 * XXX doesn't belong here
   1378 		 */
   1379 		if (ni->ni_rxfrag[0] != NULL &&
   1380 		    ticks > ni->ni_rxfragstamp + hz) {
   1381 			m_freem(ni->ni_rxfrag[0]);
   1382 			ni->ni_rxfrag[0] = NULL;
   1383 		}
   1384 		/*
   1385 		 * Special case ourself; we may be idle for extended periods
   1386 		 * of time and regardless reclaiming our state is wrong.
   1387 		 */
   1388 		if (ni == ic->ic_bss)
   1389 			continue;
   1390 		ni->ni_inact--;
   1391 		if (ni->ni_associd != 0) {
   1392 			/*
   1393 			 * Age frames on the power save queue. The
   1394 			 * aging interval is 4 times the listen
   1395 			 * interval specified by the station.  This
   1396 			 * number is factored into the age calculations
   1397 			 * when the frame is placed on the queue.  We
   1398 			 * store ages as time differences we can check
   1399 			 * and/or adjust only the head of the list.
   1400 			 */
   1401 			if (IEEE80211_NODE_SAVEQ_QLEN(ni) != 0) {
   1402 				struct mbuf *m;
   1403 				int discard = 0;
   1404 
   1405 				IEEE80211_NODE_SAVEQ_LOCK(ni);
   1406 				while (IF_POLL(&ni->ni_savedq, m) != NULL &&
   1407 				     M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
   1408 IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER, "[%s] discard frame, age %u\n", ether_sprintf(ni->ni_macaddr), M_AGE_GET(m));/*XXX*/
   1409 					_IEEE80211_NODE_SAVEQ_DEQUEUE_HEAD(ni, m);
   1410 					m_freem(m);
   1411 					discard++;
   1412 				}
   1413 				if (m != NULL)
   1414 					M_AGE_SUB(m, IEEE80211_INACT_WAIT);
   1415 				IEEE80211_NODE_SAVEQ_UNLOCK(ni);
   1416 
   1417 				if (discard != 0) {
   1418 					IEEE80211_DPRINTF(ic,
   1419 					    IEEE80211_MSG_POWER,
   1420 					    "[%s] discard %u frames for age\n",
   1421 					    ether_sprintf(ni->ni_macaddr),
   1422 					    discard);
   1423 					IEEE80211_NODE_STAT_ADD(ni,
   1424 						ps_discard, discard);
   1425 					if (IEEE80211_NODE_SAVEQ_QLEN(ni) == 0)
   1426 						ic->ic_set_tim(ic, ni, 0);
   1427 				}
   1428 			}
   1429 			/*
   1430 			 * Probe the station before time it out.  We
   1431 			 * send a null data frame which may not be
   1432 			 * universally supported by drivers (need it
   1433 			 * for ps-poll support so it should be...).
   1434 			 */
   1435 			if (0 < ni->ni_inact &&
   1436 			    ni->ni_inact <= ic->ic_inact_probe) {
   1437 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
   1438 				    "[%s] probe station due to inactivity\n",
   1439 				    ether_sprintf(ni->ni_macaddr));
   1440 				IEEE80211_NODE_UNLOCK(nt);
   1441 				ieee80211_send_nulldata(ic, ni);
   1442 				/* XXX stat? */
   1443 				goto restart;
   1444 			}
   1445 		}
   1446 		if (ni->ni_inact <= 0) {
   1447 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
   1448 			    "[%s] station timed out due to inactivity "
   1449 			    "(refcnt %u)\n", ether_sprintf(ni->ni_macaddr),
   1450 			    ieee80211_node_refcnt(ni));
   1451 			/*
   1452 			 * Send a deauthenticate frame and drop the station.
   1453 			 * This is somewhat complicated due to reference counts
   1454 			 * and locking.  At this point a station will typically
   1455 			 * have a reference count of 1.  ieee80211_node_leave
   1456 			 * will do a "free" of the node which will drop the
   1457 			 * reference count.  But in the meantime a reference
   1458 			 * wil be held by the deauth frame.  The actual reclaim
   1459 			 * of the node will happen either after the tx is
   1460 			 * completed or by ieee80211_node_leave.
   1461 			 *
   1462 			 * Separately we must drop the node lock before sending
   1463 			 * in case the driver takes a lock, as this will result
   1464 			 * in  LOR between the node lock and the driver lock.
   1465 			 */
   1466 			IEEE80211_NODE_UNLOCK(nt);
   1467 			if (ni->ni_associd != 0) {
   1468 				IEEE80211_SEND_MGMT(ic, ni,
   1469 				    IEEE80211_FC0_SUBTYPE_DEAUTH,
   1470 				    IEEE80211_REASON_AUTH_EXPIRE);
   1471 			}
   1472 			ieee80211_node_leave(ic, ni);
   1473 			ic->ic_stats.is_node_timeout++;
   1474 			goto restart;
   1475 		}
   1476 	}
   1477 	IEEE80211_NODE_UNLOCK(nt);
   1478 
   1479 	IEEE80211_SCAN_UNLOCK(nt);
   1480 
   1481 	nt->nt_inact_timer = IEEE80211_INACT_WAIT;
   1482 }
   1483 
   1484 void
   1485 ieee80211_iterate_nodes(struct ieee80211_node_table *nt, ieee80211_iter_func *f, void *arg)
   1486 {
   1487 	struct ieee80211_node *ni;
   1488 	u_int gen;
   1489 
   1490 	IEEE80211_SCAN_LOCK(nt);
   1491 	gen = nt->nt_scangen++;
   1492 restart:
   1493 	IEEE80211_NODE_LOCK(nt);
   1494 	TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
   1495 		if (ni->ni_scangen != gen) {
   1496 			ni->ni_scangen = gen;
   1497 			(void) ieee80211_ref_node(ni);
   1498 			IEEE80211_NODE_UNLOCK(nt);
   1499 			(*f)(arg, ni);
   1500 			ieee80211_free_node(ni);
   1501 			goto restart;
   1502 		}
   1503 	}
   1504 	IEEE80211_NODE_UNLOCK(nt);
   1505 
   1506 	IEEE80211_SCAN_UNLOCK(nt);
   1507 }
   1508 
   1509 void
   1510 ieee80211_dump_node(struct ieee80211_node_table *nt, struct ieee80211_node *ni)
   1511 {
   1512 	printf("0x%p: mac %s refcnt %d\n", ni,
   1513 		ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni));
   1514 	printf("\tscangen %u authmode %u flags 0x%x\n",
   1515 		ni->ni_scangen, ni->ni_authmode, ni->ni_flags);
   1516 	printf("\tassocid 0x%x txpower %u vlan %u\n",
   1517 		ni->ni_associd, ni->ni_txpower, ni->ni_vlan);
   1518 	printf("\ttxseq %u rxseq %u fragno %u rxfragstamp %u\n",
   1519 		ni->ni_txseqs[0],
   1520 		ni->ni_rxseqs[0] >> IEEE80211_SEQ_SEQ_SHIFT,
   1521 		ni->ni_rxseqs[0] & IEEE80211_SEQ_FRAG_MASK,
   1522 		ni->ni_rxfragstamp);
   1523 	printf("\trstamp %u rssi %u intval %u capinfo 0x%x\n",
   1524 		ni->ni_rstamp, ni->ni_rssi, ni->ni_intval, ni->ni_capinfo);
   1525 	printf("\tbssid %s essid \"%.*s\" channel %u:0x%x\n",
   1526 		ether_sprintf(ni->ni_bssid),
   1527 		ni->ni_esslen, ni->ni_essid,
   1528 		ni->ni_chan->ic_freq, ni->ni_chan->ic_flags);
   1529 	printf("\tfails %u inact %u txrate %u\n",
   1530 		ni->ni_fails, ni->ni_inact, ni->ni_txrate);
   1531 }
   1532 
   1533 void
   1534 ieee80211_dump_nodes(struct ieee80211_node_table *nt)
   1535 {
   1536 	ieee80211_iterate_nodes(nt,
   1537 		(ieee80211_iter_func *) ieee80211_dump_node, nt);
   1538 }
   1539 
   1540 /*
   1541  * Handle a station joining an 11g network.
   1542  */
   1543 static void
   1544 ieee80211_node_join_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
   1545 {
   1546 
   1547 	/*
   1548 	 * Station isn't capable of short slot time.  Bump
   1549 	 * the count of long slot time stations and disable
   1550 	 * use of short slot time.  Note that the actual switch
   1551 	 * over to long slot time use may not occur until the
   1552 	 * next beacon transmission (per sec. 7.3.1.4 of 11g).
   1553 	 */
   1554 	if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) == 0) {
   1555 		ic->ic_longslotsta++;
   1556 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1557 		    "[%s] station needs long slot time, count %d\n",
   1558 		    ether_sprintf(ni->ni_macaddr), ic->ic_longslotsta);
   1559 		/* XXX vap's w/ conflicting needs won't work */
   1560 		ieee80211_set_shortslottime(ic, 0);
   1561 	}
   1562 	/*
   1563 	 * If the new station is not an ERP station
   1564 	 * then bump the counter and enable protection
   1565 	 * if configured.
   1566 	 */
   1567 	if (!ieee80211_iserp_rateset(ic, &ni->ni_rates)) {
   1568 		ic->ic_nonerpsta++;
   1569 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1570 		    "[%s] station is !ERP, %d non-ERP stations associated\n",
   1571 		    ether_sprintf(ni->ni_macaddr), ic->ic_nonerpsta);
   1572 		/*
   1573 		 * If protection is configured, enable it.
   1574 		 */
   1575 		if (ic->ic_protmode != IEEE80211_PROT_NONE) {
   1576 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1577 			    "%s: enable use of protection\n", __func__);
   1578 			ic->ic_flags |= IEEE80211_F_USEPROT;
   1579 		}
   1580 		/*
   1581 		 * If station does not support short preamble
   1582 		 * then we must enable use of Barker preamble.
   1583 		 */
   1584 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE) == 0) {
   1585 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1586 			    "[%s] station needs long preamble\n",
   1587 			    ether_sprintf(ni->ni_macaddr));
   1588 			ic->ic_flags |= IEEE80211_F_USEBARKER;
   1589 			ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE;
   1590 		}
   1591 	} else
   1592 		ni->ni_flags |= IEEE80211_NODE_ERP;
   1593 }
   1594 
   1595 void
   1596 ieee80211_node_join(struct ieee80211com *ic, struct ieee80211_node *ni, int resp)
   1597 {
   1598 	int newassoc;
   1599 
   1600 	if (ni->ni_associd == 0) {
   1601 		u_int16_t aid;
   1602 
   1603 		/*
   1604 		 * It would be good to search the bitmap
   1605 		 * more efficiently, but this will do for now.
   1606 		 */
   1607 		for (aid = 1; aid < ic->ic_max_aid; aid++) {
   1608 			if (!IEEE80211_AID_ISSET(aid,
   1609 			    ic->ic_aid_bitmap))
   1610 				break;
   1611 		}
   1612 		if (aid >= ic->ic_max_aid) {
   1613 			IEEE80211_SEND_MGMT(ic, ni, resp,
   1614 			    IEEE80211_REASON_ASSOC_TOOMANY);
   1615 			ieee80211_node_leave(ic, ni);
   1616 			return;
   1617 		}
   1618 		ni->ni_associd = aid | 0xc000;
   1619 		IEEE80211_AID_SET(ni->ni_associd, ic->ic_aid_bitmap);
   1620 		ic->ic_sta_assoc++;
   1621 		newassoc = 1;
   1622 		if (ic->ic_curmode == IEEE80211_MODE_11G ||
   1623 		    ic->ic_curmode == IEEE80211_MODE_TURBO_G)
   1624 			ieee80211_node_join_11g(ic, ni);
   1625 	} else
   1626 		newassoc = 0;
   1627 
   1628 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG,
   1629 	    "[%s] station %sassociated at aid %d: %s preamble, %s slot time%s%s\n",
   1630 	    ether_sprintf(ni->ni_macaddr), newassoc ? "" : "re",
   1631 	    IEEE80211_NODE_AID(ni),
   1632 	    ic->ic_flags & IEEE80211_F_SHPREAMBLE ? "short" : "long",
   1633 	    ic->ic_flags & IEEE80211_F_SHSLOT ? "short" : "long",
   1634 	    ic->ic_flags & IEEE80211_F_USEPROT ? ", protection" : "",
   1635 	    ni->ni_flags & IEEE80211_NODE_QOS ? ", QoS" : ""
   1636 	);
   1637 
   1638 	/* give driver a chance to setup state like ni_txrate */
   1639 	if (ic->ic_newassoc != NULL)
   1640 		ic->ic_newassoc(ic, ni, newassoc);
   1641 	ni->ni_inact_reload = ic->ic_inact_auth;
   1642 	ni->ni_inact = ni->ni_inact_reload;
   1643 	IEEE80211_SEND_MGMT(ic, ni, resp, IEEE80211_STATUS_SUCCESS);
   1644 	/* tell the authenticator about new station */
   1645 	if (ic->ic_auth->ia_node_join != NULL)
   1646 		ic->ic_auth->ia_node_join(ic, ni);
   1647 	ieee80211_notify_node_join(ic, ni, newassoc);
   1648 }
   1649 
   1650 /*
   1651  * Handle a station leaving an 11g network.
   1652  */
   1653 static void
   1654 ieee80211_node_leave_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
   1655 {
   1656 
   1657 	KASSERT(ic->ic_curmode == IEEE80211_MODE_11G ||
   1658 		ic->ic_curmode == IEEE80211_MODE_TURBO_G,
   1659 		("not in 11g, curmode %x", ic->ic_curmode));
   1660 
   1661 	/*
   1662 	 * If a long slot station do the slot time bookkeeping.
   1663 	 */
   1664 	if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) == 0) {
   1665 		KASSERT(ic->ic_longslotsta > 0,
   1666 		    ("bogus long slot station count %d", ic->ic_longslotsta));
   1667 		ic->ic_longslotsta--;
   1668 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1669 		    "[%s] long slot time station leaves, count now %d\n",
   1670 		    ether_sprintf(ni->ni_macaddr), ic->ic_longslotsta);
   1671 		if (ic->ic_longslotsta == 0) {
   1672 			/*
   1673 			 * Re-enable use of short slot time if supported
   1674 			 * and not operating in IBSS mode (per spec).
   1675 			 */
   1676 			if ((ic->ic_caps & IEEE80211_C_SHSLOT) &&
   1677 			    ic->ic_opmode != IEEE80211_M_IBSS) {
   1678 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1679 				    "%s: re-enable use of short slot time\n",
   1680 				    __func__);
   1681 				ieee80211_set_shortslottime(ic, 1);
   1682 			}
   1683 		}
   1684 	}
   1685 	/*
   1686 	 * If a non-ERP station do the protection-related bookkeeping.
   1687 	 */
   1688 	if ((ni->ni_flags & IEEE80211_NODE_ERP) == 0) {
   1689 		KASSERT(ic->ic_nonerpsta > 0,
   1690 		    ("bogus non-ERP station count %d", ic->ic_nonerpsta));
   1691 		ic->ic_nonerpsta--;
   1692 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1693 		    "[%s] non-ERP station leaves, count now %d\n",
   1694 		    ether_sprintf(ni->ni_macaddr), ic->ic_nonerpsta);
   1695 		if (ic->ic_nonerpsta == 0) {
   1696 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1697 				"%s: disable use of protection\n", __func__);
   1698 			ic->ic_flags &= ~IEEE80211_F_USEPROT;
   1699 			/* XXX verify mode? */
   1700 			if (ic->ic_caps & IEEE80211_C_SHPREAMBLE) {
   1701 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
   1702 				    "%s: re-enable use of short preamble\n",
   1703 				    __func__);
   1704 				ic->ic_flags |= IEEE80211_F_SHPREAMBLE;
   1705 				ic->ic_flags &= ~IEEE80211_F_USEBARKER;
   1706 			}
   1707 		}
   1708 	}
   1709 }
   1710 
   1711 /*
   1712  * Handle bookkeeping for station deauthentication/disassociation
   1713  * when operating as an ap.
   1714  */
   1715 void
   1716 ieee80211_node_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
   1717 {
   1718 	struct ieee80211_node_table *nt = ni->ni_table;
   1719 
   1720 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG,
   1721 	    "[%s] station with aid %d leaves\n",
   1722 	    ether_sprintf(ni->ni_macaddr), IEEE80211_NODE_AID(ni));
   1723 
   1724 	KASSERT(ic->ic_opmode == IEEE80211_M_HOSTAP ||
   1725 		ic->ic_opmode == IEEE80211_M_IBSS ||
   1726 		ic->ic_opmode == IEEE80211_M_AHDEMO,
   1727 		("unexpected operating mode %u", ic->ic_opmode));
   1728 	/*
   1729 	 * If node wasn't previously associated all
   1730 	 * we need to do is reclaim the reference.
   1731 	 */
   1732 	/* XXX ibss mode bypasses 11g and notification */
   1733 	if (ni->ni_associd == 0)
   1734 		goto done;
   1735 	/*
   1736 	 * Tell the authenticator the station is leaving.
   1737 	 * Note that we must do this before yanking the
   1738 	 * association id as the authenticator uses the
   1739 	 * associd to locate it's state block.
   1740 	 */
   1741 	if (ic->ic_auth->ia_node_leave != NULL)
   1742 		ic->ic_auth->ia_node_leave(ic, ni);
   1743 	IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
   1744 	ni->ni_associd = 0;
   1745 	ic->ic_sta_assoc--;
   1746 
   1747 	if (ic->ic_curmode == IEEE80211_MODE_11G ||
   1748 	    ic->ic_curmode == IEEE80211_MODE_TURBO_G)
   1749 		ieee80211_node_leave_11g(ic, ni);
   1750 	/*
   1751 	 * Cleanup station state.  In particular clear various
   1752 	 * state that might otherwise be reused if the node
   1753 	 * is reused before the reference count goes to zero
   1754 	 * (and memory is reclaimed).
   1755 	 */
   1756 	ieee80211_sta_leave(ic, ni);
   1757 done:
   1758 	/*
   1759 	 * Remove the node from any table it's recorded in and
   1760 	 * drop the caller's reference.  Removal from the table
   1761 	 * is important to insure the node is not reprocessed
   1762 	 * for inactivity.
   1763 	 */
   1764 	if (nt != NULL) {
   1765 		IEEE80211_NODE_LOCK(nt);
   1766 		node_reclaim(nt, ni);
   1767 		IEEE80211_NODE_UNLOCK(nt);
   1768 	} else
   1769 		ieee80211_free_node(ni);
   1770 }
   1771 
   1772 u_int8_t
   1773 ieee80211_getrssi(struct ieee80211com *ic)
   1774 {
   1775 #define	NZ(x)	((x) == 0 ? 1 : (x))
   1776 	struct ieee80211_node_table *nt = &ic->ic_sta;
   1777 	u_int32_t rssi_samples, rssi_total;
   1778 	struct ieee80211_node *ni;
   1779 
   1780 	rssi_total = 0;
   1781 	rssi_samples = 0;
   1782 	switch (ic->ic_opmode) {
   1783 	case IEEE80211_M_IBSS:		/* average of all ibss neighbors */
   1784 		/* XXX locking */
   1785 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list)
   1786 			if (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) {
   1787 				rssi_samples++;
   1788 				rssi_total += ic->ic_node_getrssi(ni);
   1789 			}
   1790 		break;
   1791 	case IEEE80211_M_AHDEMO:	/* average of all neighbors */
   1792 		/* XXX locking */
   1793 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
   1794 			rssi_samples++;
   1795 			rssi_total += ic->ic_node_getrssi(ni);
   1796 		}
   1797 		break;
   1798 	case IEEE80211_M_HOSTAP:	/* average of all associated stations */
   1799 		/* XXX locking */
   1800 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list)
   1801 			if (IEEE80211_AID(ni->ni_associd) != 0) {
   1802 				rssi_samples++;
   1803 				rssi_total += ic->ic_node_getrssi(ni);
   1804 			}
   1805 		break;
   1806 	case IEEE80211_M_MONITOR:	/* XXX */
   1807 	case IEEE80211_M_STA:		/* use stats from associated ap */
   1808 	default:
   1809 		if (ic->ic_bss != NULL)
   1810 			rssi_total = ic->ic_node_getrssi(ic->ic_bss);
   1811 		rssi_samples = 1;
   1812 		break;
   1813 	}
   1814 	return rssi_total / NZ(rssi_samples);
   1815 #undef NZ
   1816 }
   1817 
   1818 /*
   1819  * Indicate whether there are frames queued for a station in power-save mode.
   1820  */
   1821 static void
   1822 ieee80211_set_tim(struct ieee80211com *ic, struct ieee80211_node *ni, int set)
   1823 {
   1824 	u_int16_t aid;
   1825 
   1826 	KASSERT(ic->ic_opmode == IEEE80211_M_HOSTAP ||
   1827 		ic->ic_opmode == IEEE80211_M_IBSS,
   1828 		("operating mode %u", ic->ic_opmode));
   1829 
   1830 	aid = IEEE80211_AID(ni->ni_associd);
   1831 	KASSERT(aid < ic->ic_max_aid,
   1832 		("bogus aid %u, max %u", aid, ic->ic_max_aid));
   1833 
   1834 	IEEE80211_BEACON_LOCK(ic);
   1835 	if (set != (isset(ic->ic_tim_bitmap, aid) != 0)) {
   1836 		if (set) {
   1837 			setbit(ic->ic_tim_bitmap, aid);
   1838 			ic->ic_ps_pending++;
   1839 		} else {
   1840 			clrbit(ic->ic_tim_bitmap, aid);
   1841 			ic->ic_ps_pending--;
   1842 		}
   1843 		ic->ic_flags |= IEEE80211_F_TIMUPDATE;
   1844 	}
   1845 	IEEE80211_BEACON_UNLOCK(ic);
   1846 }
   1847 
   1848 /*
   1849  * Node table support.
   1850  */
   1851 
   1852 static void
   1853 ieee80211_node_table_init(struct ieee80211com *ic,
   1854 	struct ieee80211_node_table *nt,
   1855 	const char *name, int inact,
   1856 	void (*timeout)(struct ieee80211_node_table *))
   1857 {
   1858 
   1859 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
   1860 		"%s %s table, inact %u\n", __func__, name, inact);
   1861 
   1862 	nt->nt_ic = ic;
   1863 	/* XXX need unit */
   1864 	IEEE80211_NODE_LOCK_INIT(nt, ic->ic_ifp->if_xname);
   1865 	IEEE80211_SCAN_LOCK_INIT(nt, ic->ic_ifp->if_xname);
   1866 	TAILQ_INIT(&nt->nt_node);
   1867 	nt->nt_name = name;
   1868 	nt->nt_scangen = 1;
   1869 	nt->nt_inact_init = inact;
   1870 	nt->nt_timeout = timeout;
   1871 }
   1872 
   1873 void
   1874 ieee80211_node_table_reset(struct ieee80211_node_table *nt)
   1875 {
   1876 
   1877 	IEEE80211_DPRINTF(nt->nt_ic, IEEE80211_MSG_NODE,
   1878 		"%s %s table\n", __func__, nt->nt_name);
   1879 
   1880 	IEEE80211_NODE_LOCK(nt);
   1881 	nt->nt_inact_timer = 0;
   1882 	ieee80211_free_allnodes_locked(nt);
   1883 	IEEE80211_NODE_UNLOCK(nt);
   1884 }
   1885 
   1886 static void
   1887 ieee80211_node_table_cleanup(struct ieee80211_node_table *nt)
   1888 {
   1889 
   1890 	IEEE80211_DPRINTF(nt->nt_ic, IEEE80211_MSG_NODE,
   1891 		"%s %s table\n", __func__, nt->nt_name);
   1892 
   1893 	ieee80211_free_allnodes_locked(nt);
   1894 	IEEE80211_SCAN_LOCK_DESTROY(nt);
   1895 	IEEE80211_NODE_LOCK_DESTROY(nt);
   1896 }
   1897