xref: /freebsd/sys/net80211/ieee80211_node.c (revision ea8cbba64fcbb6b3f2fec5d8aea8f92a5f8fcdda)
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("$FreeBSD$");
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 /*
53  * Association id's are managed with a bit vector.
54  */
55 #define	IEEE80211_AID_SET(b, w) \
56 	((w)[IEEE80211_AID(b) / 32] |= (1 << (IEEE80211_AID(b) % 32)))
57 #define	IEEE80211_AID_CLR(b, w) \
58 	((w)[IEEE80211_AID(b) / 32] &= ~(1 << (IEEE80211_AID(b) % 32)))
59 #define	IEEE80211_AID_ISSET(b, w) \
60 	((w)[IEEE80211_AID(b) / 32] & (1 << (IEEE80211_AID(b) % 32)))
61 
62 static struct ieee80211_node *node_alloc(struct ieee80211_node_table *);
63 static void node_cleanup(struct ieee80211_node *);
64 static void node_free(struct ieee80211_node *);
65 static u_int8_t node_getrssi(const struct ieee80211_node *);
66 
67 static void ieee80211_setup_node(struct ieee80211_node_table *,
68 		struct ieee80211_node *, const u_int8_t *);
69 static void _ieee80211_free_node(struct ieee80211_node *);
70 static void ieee80211_free_allnodes(struct ieee80211_node_table *);
71 
72 static void ieee80211_timeout_scan_candidates(struct ieee80211_node_table *);
73 static void ieee80211_timeout_stations(struct ieee80211_node_table *);
74 
75 static void ieee80211_set_tim(struct ieee80211_node *, int set);
76 
77 static void ieee80211_node_table_init(struct ieee80211com *ic,
78 	struct ieee80211_node_table *nt, const char *name,
79 	int inact, int keyixmax,
80 	void (*timeout)(struct ieee80211_node_table *));
81 static void ieee80211_node_table_cleanup(struct ieee80211_node_table *nt);
82 
83 MALLOC_DEFINE(M_80211_NODE, "80211node", "802.11 node state");
84 
85 void
86 ieee80211_node_attach(struct ieee80211com *ic)
87 {
88 
89 	ic->ic_node_alloc = node_alloc;
90 	ic->ic_node_free = node_free;
91 	ic->ic_node_cleanup = node_cleanup;
92 	ic->ic_node_getrssi = node_getrssi;
93 
94 	/* default station inactivity timer setings */
95 	ic->ic_inact_init = IEEE80211_INACT_INIT;
96 	ic->ic_inact_auth = IEEE80211_INACT_AUTH;
97 	ic->ic_inact_run = IEEE80211_INACT_RUN;
98 	ic->ic_inact_probe = IEEE80211_INACT_PROBE;
99 
100 	/* NB: driver should override */
101 	ic->ic_max_aid = IEEE80211_AID_DEF;
102 	ic->ic_set_tim = ieee80211_set_tim;
103 }
104 
105 void
106 ieee80211_node_lateattach(struct ieee80211com *ic)
107 {
108 	struct ieee80211_rsnparms *rsn;
109 
110 	if (ic->ic_max_aid > IEEE80211_AID_MAX)
111 		ic->ic_max_aid = IEEE80211_AID_MAX;
112 	MALLOC(ic->ic_aid_bitmap, u_int32_t *,
113 		howmany(ic->ic_max_aid, 32) * sizeof(u_int32_t),
114 		M_DEVBUF, M_NOWAIT | M_ZERO);
115 	if (ic->ic_aid_bitmap == NULL) {
116 		/* XXX no way to recover */
117 		printf("%s: no memory for AID bitmap!\n", __func__);
118 		ic->ic_max_aid = 0;
119 	}
120 
121 	/* XXX defer until using hostap/ibss mode */
122 	ic->ic_tim_len = howmany(ic->ic_max_aid, 8) * sizeof(u_int8_t);
123 	MALLOC(ic->ic_tim_bitmap, u_int8_t *, ic->ic_tim_len,
124 		M_DEVBUF, M_NOWAIT | M_ZERO);
125 	if (ic->ic_tim_bitmap == NULL) {
126 		/* XXX no way to recover */
127 		printf("%s: no memory for TIM bitmap!\n", __func__);
128 	}
129 
130 	ieee80211_node_table_init(ic, &ic->ic_sta, "station",
131 		IEEE80211_INACT_INIT, ic->ic_crypto.cs_max_keyix,
132 		ieee80211_timeout_stations);
133 	ieee80211_node_table_init(ic, &ic->ic_scan, "scan",
134 		IEEE80211_INACT_SCAN, 0,
135 		ieee80211_timeout_scan_candidates);
136 
137 	ieee80211_reset_bss(ic);
138 	/*
139 	 * Setup "global settings" in the bss node so that
140 	 * each new station automatically inherits them.
141 	 */
142 	rsn = &ic->ic_bss->ni_rsn;
143 	/* WEP, TKIP, and AES-CCM are always supported */
144 	rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_WEP;
145 	rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_TKIP;
146 	rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_AES_CCM;
147 	if (ic->ic_caps & IEEE80211_C_AES)
148 		rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_AES_OCB;
149 	if (ic->ic_caps & IEEE80211_C_CKIP)
150 		rsn->rsn_ucastcipherset |= 1<<IEEE80211_CIPHER_CKIP;
151 	/*
152 	 * Default unicast cipher to WEP for 802.1x use.  If
153 	 * WPA is enabled the management code will set these
154 	 * values to reflect.
155 	 */
156 	rsn->rsn_ucastcipher = IEEE80211_CIPHER_WEP;
157 	rsn->rsn_ucastkeylen = 104 / NBBY;
158 	/*
159 	 * WPA says the multicast cipher is the lowest unicast
160 	 * cipher supported.  But we skip WEP which would
161 	 * otherwise be used based on this criteria.
162 	 */
163 	rsn->rsn_mcastcipher = IEEE80211_CIPHER_TKIP;
164 	rsn->rsn_mcastkeylen = 128 / NBBY;
165 
166 	/*
167 	 * We support both WPA-PSK and 802.1x; the one used
168 	 * is determined by the authentication mode and the
169 	 * setting of the PSK state.
170 	 */
171 	rsn->rsn_keymgmtset = WPA_ASE_8021X_UNSPEC | WPA_ASE_8021X_PSK;
172 	rsn->rsn_keymgmt = WPA_ASE_8021X_PSK;
173 
174 	ic->ic_auth = ieee80211_authenticator_get(ic->ic_bss->ni_authmode);
175 }
176 
177 void
178 ieee80211_node_detach(struct ieee80211com *ic)
179 {
180 
181 	if (ic->ic_bss != NULL) {
182 		ieee80211_free_node(ic->ic_bss);
183 		ic->ic_bss = NULL;
184 	}
185 	ieee80211_node_table_cleanup(&ic->ic_scan);
186 	ieee80211_node_table_cleanup(&ic->ic_sta);
187 	if (ic->ic_aid_bitmap != NULL) {
188 		FREE(ic->ic_aid_bitmap, M_DEVBUF);
189 		ic->ic_aid_bitmap = NULL;
190 	}
191 	if (ic->ic_tim_bitmap != NULL) {
192 		FREE(ic->ic_tim_bitmap, M_DEVBUF);
193 		ic->ic_tim_bitmap = NULL;
194 	}
195 }
196 
197 /*
198  * Port authorize/unauthorize interfaces for use by an authenticator.
199  */
200 
201 void
202 ieee80211_node_authorize(struct ieee80211_node *ni)
203 {
204 	struct ieee80211com *ic = ni->ni_ic;
205 
206 	ni->ni_flags |= IEEE80211_NODE_AUTH;
207 	ni->ni_inact_reload = ic->ic_inact_run;
208 }
209 
210 void
211 ieee80211_node_unauthorize(struct ieee80211_node *ni)
212 {
213 	ni->ni_flags &= ~IEEE80211_NODE_AUTH;
214 }
215 
216 /*
217  * Set/change the channel.  The rate set is also updated as
218  * to insure a consistent view by drivers.
219  */
220 static __inline void
221 ieee80211_set_chan(struct ieee80211com *ic,
222 	struct ieee80211_node *ni, struct ieee80211_channel *chan)
223 {
224 	ni->ni_chan = chan;
225 	ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, chan)];
226 }
227 
228 /*
229  * AP scanning support.
230  */
231 
232 #ifdef IEEE80211_DEBUG
233 static void
234 dump_chanlist(const u_char chans[])
235 {
236 	const char *sep;
237 	int i;
238 
239 	sep = " ";
240 	for (i = 0; i < IEEE80211_CHAN_MAX; i++)
241 		if (isset(chans, i)) {
242 			printf("%s%u", sep, i);
243 			sep = ", ";
244 		}
245 }
246 #endif /* IEEE80211_DEBUG */
247 
248 /*
249  * Initialize the channel set to scan based on the
250  * of available channels and the current PHY mode.
251  */
252 static void
253 ieee80211_reset_scan(struct ieee80211com *ic)
254 {
255 
256 	/* XXX ic_des_chan should be handled with ic_chan_active */
257 	if (ic->ic_des_chan != IEEE80211_CHAN_ANYC) {
258 		memset(ic->ic_chan_scan, 0, sizeof(ic->ic_chan_scan));
259 		setbit(ic->ic_chan_scan,
260 			ieee80211_chan2ieee(ic, ic->ic_des_chan));
261 	} else
262 		memcpy(ic->ic_chan_scan, ic->ic_chan_active,
263 			sizeof(ic->ic_chan_active));
264 #ifdef IEEE80211_DEBUG
265 	if (ieee80211_msg_scan(ic)) {
266 		printf("%s: scan set:", __func__);
267 		dump_chanlist(ic->ic_chan_scan);
268 		printf(" start chan %u\n",
269 			ieee80211_chan2ieee(ic, ic->ic_curchan));
270 	}
271 #endif /* IEEE80211_DEBUG */
272 }
273 
274 /*
275  * Begin an active scan.
276  */
277 void
278 ieee80211_begin_scan(struct ieee80211com *ic, int reset)
279 {
280 
281 	ic->ic_scan.nt_scangen++;
282 	/*
283 	 * In all but hostap mode scanning starts off in
284 	 * an active mode before switching to passive.
285 	 */
286 	if (ic->ic_opmode != IEEE80211_M_HOSTAP) {
287 		ic->ic_flags |= IEEE80211_F_ASCAN;
288 		ic->ic_stats.is_scan_active++;
289 	} else
290 		ic->ic_stats.is_scan_passive++;
291 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
292 		"begin %s scan in %s mode, scangen %u\n",
293 		(ic->ic_flags & IEEE80211_F_ASCAN) ?  "active" : "passive",
294 		ieee80211_phymode_name[ic->ic_curmode], ic->ic_scan.nt_scangen);
295 	/*
296 	 * Clear scan state and flush any previously seen AP's.
297 	 */
298 	ieee80211_reset_scan(ic);
299 	if (reset)
300 		ieee80211_free_allnodes(&ic->ic_scan);
301 
302 	ic->ic_flags |= IEEE80211_F_SCAN;
303 
304 	/* Scan the next channel. */
305 	ieee80211_next_scan(ic);
306 }
307 
308 /*
309  * Switch to the next channel marked for scanning.
310  */
311 int
312 ieee80211_next_scan(struct ieee80211com *ic)
313 {
314 	struct ieee80211_channel *chan;
315 
316 	/*
317 	 * Insure any previous mgt frame timeouts don't fire.
318 	 * This assumes the driver does the right thing in
319 	 * flushing anything queued in the driver and below.
320 	 */
321 	ic->ic_mgt_timer = 0;
322 
323 	chan = ic->ic_curchan;
324 	do {
325 		if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX])
326 			chan = &ic->ic_channels[0];
327 		if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) {
328 			clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan));
329 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
330 			    "%s: chan %d->%d\n", __func__,
331 			    ieee80211_chan2ieee(ic, ic->ic_curchan),
332 			    ieee80211_chan2ieee(ic, chan));
333 			ic->ic_curchan = chan;
334 			/*
335 			 * XXX drivers should do this as needed,
336 			 * XXX for now maintain compatibility
337 			 */
338 			ic->ic_bss->ni_rates =
339 				ic->ic_sup_rates[ieee80211_chan2mode(ic, chan)];
340 			ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
341 			return 1;
342 		}
343 	} while (chan != ic->ic_curchan);
344 	ieee80211_end_scan(ic);
345 	return 0;
346 }
347 
348 static __inline void
349 copy_bss(struct ieee80211_node *nbss, const struct ieee80211_node *obss)
350 {
351 	/* propagate useful state */
352 	nbss->ni_authmode = obss->ni_authmode;
353 	nbss->ni_txpower = obss->ni_txpower;
354 	nbss->ni_vlan = obss->ni_vlan;
355 	nbss->ni_rsn = obss->ni_rsn;
356 	/* XXX statistics? */
357 }
358 
359 void
360 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan)
361 {
362 	struct ieee80211_node_table *nt;
363 	struct ieee80211_node *ni;
364 
365 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
366 		"%s: creating ibss\n", __func__);
367 
368 	/*
369 	 * Create the station/neighbor table.  Note that for adhoc
370 	 * mode we make the initial inactivity timer longer since
371 	 * we create nodes only through discovery and they typically
372 	 * are long-lived associations.
373 	 */
374 	nt = &ic->ic_sta;
375 	IEEE80211_NODE_LOCK(nt);
376 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
377 		nt->nt_name = "station";
378 		nt->nt_inact_init = ic->ic_inact_init;
379 	} else {
380 		nt->nt_name = "neighbor";
381 		nt->nt_inact_init = ic->ic_inact_run;
382 	}
383 	IEEE80211_NODE_UNLOCK(nt);
384 
385 	ni = ieee80211_alloc_node(&ic->ic_sta, ic->ic_myaddr);
386 	if (ni == NULL) {
387 		/* XXX recovery? */
388 		return;
389 	}
390 	IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr);
391 	ni->ni_esslen = ic->ic_des_esslen;
392 	memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen);
393 	copy_bss(ni, ic->ic_bss);
394 	ni->ni_intval = ic->ic_bintval;
395 	if (ic->ic_flags & IEEE80211_F_PRIVACY)
396 		ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
397 	if (ic->ic_phytype == IEEE80211_T_FH) {
398 		ni->ni_fhdwell = 200;	/* XXX */
399 		ni->ni_fhindex = 1;
400 	}
401 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
402 		ic->ic_flags |= IEEE80211_F_SIBSS;
403 		ni->ni_capinfo |= IEEE80211_CAPINFO_IBSS;	/* XXX */
404 		if (ic->ic_flags & IEEE80211_F_DESBSSID)
405 			IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_des_bssid);
406 		else
407 			ni->ni_bssid[0] |= 0x02;	/* local bit for IBSS */
408 	}
409 	/*
410 	 * Fix the channel and related attributes.
411 	 */
412 	ieee80211_set_chan(ic, ni, chan);
413 	ic->ic_curchan = chan;
414 	ic->ic_curmode = ieee80211_chan2mode(ic, chan);
415 	/*
416 	 * Do mode-specific rate setup.
417 	 */
418 	if (ic->ic_curmode == IEEE80211_MODE_11G) {
419 		/*
420 		 * Use a mixed 11b/11g rate set.
421 		 */
422 		ieee80211_set11gbasicrates(&ni->ni_rates, IEEE80211_MODE_11G);
423 	} else if (ic->ic_curmode == IEEE80211_MODE_11B) {
424 		/*
425 		 * Force pure 11b rate set.
426 		 */
427 		ieee80211_set11gbasicrates(&ni->ni_rates, IEEE80211_MODE_11B);
428 	}
429 
430 	(void) ieee80211_sta_join(ic, ieee80211_ref_node(ni));
431 }
432 
433 void
434 ieee80211_reset_bss(struct ieee80211com *ic)
435 {
436 	struct ieee80211_node *ni, *obss;
437 
438 	ieee80211_node_table_reset(&ic->ic_scan);
439 	ieee80211_node_table_reset(&ic->ic_sta);
440 
441 	ni = ieee80211_alloc_node(&ic->ic_scan, ic->ic_myaddr);
442 	KASSERT(ni != NULL, ("unable to setup inital BSS node"));
443 	obss = ic->ic_bss;
444 	ic->ic_bss = ieee80211_ref_node(ni);
445 	if (obss != NULL) {
446 		copy_bss(ni, obss);
447 		ni->ni_intval = ic->ic_bintval;
448 		ieee80211_free_node(obss);
449 	}
450 }
451 
452 /* XXX tunable */
453 #define	STA_FAILS_MAX	2		/* assoc failures before ignored */
454 
455 static int
456 ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni)
457 {
458         u_int8_t rate;
459         int fail;
460 
461 	fail = 0;
462 	if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
463 		fail |= 0x01;
464 	if (ic->ic_des_chan != IEEE80211_CHAN_ANYC &&
465 	    ni->ni_chan != ic->ic_des_chan)
466 		fail |= 0x01;
467 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
468 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
469 			fail |= 0x02;
470 	} else {
471 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
472 			fail |= 0x02;
473 	}
474 	if (ic->ic_flags & IEEE80211_F_PRIVACY) {
475 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
476 			fail |= 0x04;
477 	} else {
478 		/* XXX does this mean privacy is supported or required? */
479 		if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
480 			fail |= 0x04;
481 	}
482 	rate = ieee80211_fix_rate(ni, IEEE80211_F_DONEGO | IEEE80211_F_DOFRATE);
483 	if (rate & IEEE80211_RATE_BASIC)
484 		fail |= 0x08;
485 	if (ic->ic_des_esslen != 0 &&
486 	    (ni->ni_esslen != ic->ic_des_esslen ||
487 	     memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0))
488 		fail |= 0x10;
489 	if ((ic->ic_flags & IEEE80211_F_DESBSSID) &&
490 	    !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid))
491 		fail |= 0x20;
492 	if (ni->ni_fails >= STA_FAILS_MAX)
493 		fail |= 0x40;
494 #ifdef IEEE80211_DEBUG
495 	if (ieee80211_msg_scan(ic)) {
496 		printf(" %c %s",
497 		    fail & 0x40 ? '=' : fail & 0x80 ? '^' : fail ? '-' : '+',
498 		    ether_sprintf(ni->ni_macaddr));
499 		printf(" %s%c", ether_sprintf(ni->ni_bssid),
500 		    fail & 0x20 ? '!' : ' ');
501 		printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan),
502 			fail & 0x01 ? '!' : ' ');
503 		printf(" %+4d", ni->ni_rssi);
504 		printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
505 		    fail & 0x08 ? '!' : ' ');
506 		printf(" %4s%c",
507 		    (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
508 		    (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
509 		    "????",
510 		    fail & 0x02 ? '!' : ' ');
511 		printf(" %3s%c ",
512 		    (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
513 		    "wep" : "no",
514 		    fail & 0x04 ? '!' : ' ');
515 		ieee80211_print_essid(ni->ni_essid, ni->ni_esslen);
516 		printf("%s\n", fail & 0x10 ? "!" : "");
517 	}
518 #endif
519 	return fail;
520 }
521 
522 static __inline u_int8_t
523 maxrate(const struct ieee80211_node *ni)
524 {
525 	const struct ieee80211_rateset *rs = &ni->ni_rates;
526 	/* NB: assumes rate set is sorted (happens on frame receive) */
527 	return rs->rs_rates[rs->rs_nrates-1] & IEEE80211_RATE_VAL;
528 }
529 
530 /*
531  * Compare the capabilities of two nodes and decide which is
532  * more desirable (return >0 if a is considered better).  Note
533  * that we assume compatibility/usability has already been checked
534  * so we don't need to (e.g. validate whether privacy is supported).
535  * Used to select the best scan candidate for association in a BSS.
536  */
537 static int
538 ieee80211_node_compare(struct ieee80211com *ic,
539 		       const struct ieee80211_node *a,
540 		       const struct ieee80211_node *b)
541 {
542 	u_int8_t maxa, maxb;
543 	u_int8_t rssia, rssib;
544 	int weight;
545 
546 	/* privacy support preferred */
547 	if ((a->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) &&
548 	    (b->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
549 		return 1;
550 	if ((a->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0 &&
551 	    (b->ni_capinfo & IEEE80211_CAPINFO_PRIVACY))
552 		return -1;
553 
554 	/* compare count of previous failures */
555 	weight = b->ni_fails - a->ni_fails;
556 	if (abs(weight) > 1)
557 		return weight;
558 
559 	rssia = ic->ic_node_getrssi(a);
560 	rssib = ic->ic_node_getrssi(b);
561 	if (abs(rssib - rssia) < 5) {
562 		/* best/max rate preferred if signal level close enough XXX */
563 		maxa = maxrate(a);
564 		maxb = maxrate(b);
565 		if (maxa != maxb)
566 			return maxa - maxb;
567 		/* XXX use freq for channel preference */
568 		/* for now just prefer 5Ghz band to all other bands */
569 		if (IEEE80211_IS_CHAN_5GHZ(a->ni_chan) &&
570 		   !IEEE80211_IS_CHAN_5GHZ(b->ni_chan))
571 			return 1;
572 		if (!IEEE80211_IS_CHAN_5GHZ(a->ni_chan) &&
573 		     IEEE80211_IS_CHAN_5GHZ(b->ni_chan))
574 			return -1;
575 	}
576 	/* all things being equal, use signal level */
577 	return rssia - rssib;
578 }
579 
580 /*
581  * Mark an ongoing scan stopped.
582  */
583 void
584 ieee80211_cancel_scan(struct ieee80211com *ic)
585 {
586 
587 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, "%s: end %s scan\n",
588 		__func__,
589 		(ic->ic_flags & IEEE80211_F_ASCAN) ?  "active" : "passive");
590 
591 	ic->ic_flags &= ~(IEEE80211_F_SCAN | IEEE80211_F_ASCAN);
592 }
593 
594 /*
595  * Complete a scan of potential channels.
596  */
597 void
598 ieee80211_end_scan(struct ieee80211com *ic)
599 {
600 	struct ieee80211_node_table *nt = &ic->ic_scan;
601 	struct ieee80211_node *ni, *selbs;
602 
603 	ieee80211_cancel_scan(ic);
604 	ieee80211_notify_scan_done(ic);
605 
606 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
607 		u_int8_t maxrssi[IEEE80211_CHAN_MAX];	/* XXX off stack? */
608 		int i, bestchan;
609 		u_int8_t rssi;
610 
611 		/*
612 		 * The passive scan to look for existing AP's completed,
613 		 * select a channel to camp on.  Identify the channels
614 		 * that already have one or more AP's and try to locate
615 		 * an unoccupied one.  If that fails, pick a channel that
616 		 * looks to be quietest.
617 		 */
618 		memset(maxrssi, 0, sizeof(maxrssi));
619 		IEEE80211_NODE_LOCK(nt);
620 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
621 			rssi = ic->ic_node_getrssi(ni);
622 			i = ieee80211_chan2ieee(ic, ni->ni_chan);
623 			if (rssi > maxrssi[i])
624 				maxrssi[i] = rssi;
625 		}
626 		IEEE80211_NODE_UNLOCK(nt);
627 		/* XXX select channel more intelligently */
628 		bestchan = -1;
629 		for (i = 0; i < IEEE80211_CHAN_MAX; i++)
630 			if (isset(ic->ic_chan_active, i)) {
631 				/*
632 				 * If the channel is unoccupied the max rssi
633 				 * should be zero; just take it.  Otherwise
634 				 * track the channel with the lowest rssi and
635 				 * use that when all channels appear occupied.
636 				 */
637 				if (maxrssi[i] == 0) {
638 					bestchan = i;
639 					break;
640 				}
641 				if (bestchan == -1 ||
642 				    maxrssi[i] < maxrssi[bestchan])
643 					bestchan = i;
644 			}
645 		if (bestchan != -1) {
646 			ieee80211_create_ibss(ic, &ic->ic_channels[bestchan]);
647 			return;
648 		}
649 		/* no suitable channel, should not happen */
650 	}
651 
652 	/*
653 	 * When manually sequencing the state machine; scan just once
654 	 * regardless of whether we have a candidate or not.  The
655 	 * controlling application is expected to setup state and
656 	 * initiate an association.
657 	 */
658 	if (ic->ic_roaming == IEEE80211_ROAMING_MANUAL)
659 		return;
660 	/*
661 	 * Automatic sequencing; look for a candidate and
662 	 * if found join the network.
663 	 */
664 	/* NB: unlocked read should be ok */
665 	if (TAILQ_FIRST(&nt->nt_node) == NULL) {
666 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN,
667 			"%s: no scan candidate\n", __func__);
668   notfound:
669 		if (ic->ic_opmode == IEEE80211_M_IBSS &&
670 		    (ic->ic_flags & IEEE80211_F_IBSSON) &&
671 		    ic->ic_des_esslen != 0) {
672 			ieee80211_create_ibss(ic, ic->ic_ibss_chan);
673 			return;
674 		}
675 		/*
676 		 * Decrement the failure counts so entries will be
677 		 * reconsidered the next time around.  We really want
678 		 * to do this only for sta's where we've previously
679 		 had some success.
680 		 */
681 		IEEE80211_NODE_LOCK(nt);
682 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list)
683 			if (ni->ni_fails)
684 				ni->ni_fails--;
685 		IEEE80211_NODE_UNLOCK(nt);
686 		/*
687 		 * Reset the list of channels to scan and start again.
688 		 */
689 		ieee80211_reset_scan(ic);
690 		ic->ic_flags |= IEEE80211_F_SCAN;
691 		ieee80211_next_scan(ic);
692 		return;
693 	}
694 	selbs = NULL;
695 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_SCAN, "\t%s\n",
696 	    "macaddr          bssid         chan  rssi rate flag  wep  essid");
697 	IEEE80211_NODE_LOCK(nt);
698 	TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
699 		if (ieee80211_match_bss(ic, ni) == 0) {
700 			if (selbs == NULL)
701 				selbs = ni;
702 			else if (ieee80211_node_compare(ic, ni, selbs) > 0)
703 				selbs = ni;
704 		}
705 	}
706 	if (selbs != NULL)		/* NB: grab ref while dropping lock */
707 		(void) ieee80211_ref_node(selbs);
708 	IEEE80211_NODE_UNLOCK(nt);
709 	if (selbs == NULL)
710 		goto notfound;
711 	if (!ieee80211_sta_join(ic, selbs)) {
712 		ieee80211_free_node(selbs);
713 		goto notfound;
714 	}
715 }
716 
717 /*
718  * Handle 802.11 ad hoc network merge.  The
719  * convention, set by the Wireless Ethernet Compatibility Alliance
720  * (WECA), is that an 802.11 station will change its BSSID to match
721  * the "oldest" 802.11 ad hoc network, on the same channel, that
722  * has the station's desired SSID.  The "oldest" 802.11 network
723  * sends beacons with the greatest TSF timestamp.
724  *
725  * The caller is assumed to validate TSF's before attempting a merge.
726  *
727  * Return !0 if the BSSID changed, 0 otherwise.
728  */
729 int
730 ieee80211_ibss_merge(struct ieee80211_node *ni)
731 {
732 	struct ieee80211com *ic = ni->ni_ic;
733 
734 	if (ni == ic->ic_bss ||
735 	    IEEE80211_ADDR_EQ(ni->ni_bssid, ic->ic_bss->ni_bssid)) {
736 		/* unchanged, nothing to do */
737 		return 0;
738 	}
739 	if (ieee80211_match_bss(ic, ni) != 0) {	/* capabilities mismatch */
740 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
741 		    "%s: merge failed, capabilities mismatch\n", __func__);
742 		ic->ic_stats.is_ibss_capmismatch++;
743 		return 0;
744 	}
745 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
746 		"%s: new bssid %s: %s preamble, %s slot time%s\n", __func__,
747 		ether_sprintf(ni->ni_bssid),
748 		ic->ic_flags&IEEE80211_F_SHPREAMBLE ? "short" : "long",
749 		ic->ic_flags&IEEE80211_F_SHSLOT ? "short" : "long",
750 		ic->ic_flags&IEEE80211_F_USEPROT ? ", protection" : ""
751 	);
752 	return ieee80211_sta_join(ic, ieee80211_ref_node(ni));
753 }
754 
755 /*
756  * Join the specified IBSS/BSS network.  The node is assumed to
757  * be passed in with a held reference.
758  */
759 int
760 ieee80211_sta_join(struct ieee80211com *ic, struct ieee80211_node *selbs)
761 {
762 	struct ieee80211_node *obss;
763 
764 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
765 		struct ieee80211_node_table *nt;
766 		/*
767 		 * Delete unusable rates; we've already checked
768 		 * that the negotiated rate set is acceptable.
769 		 */
770 		ieee80211_fix_rate(selbs, IEEE80211_F_DODEL);
771 		/*
772 		 * Fillin the neighbor table; it will already
773 		 * exist if we are simply switching mastership.
774 		 * XXX ic_sta always setup so this is unnecessary?
775 		 */
776 		nt = &ic->ic_sta;
777 		IEEE80211_NODE_LOCK(nt);
778 		nt->nt_name = "neighbor";
779 		nt->nt_inact_init = ic->ic_inact_run;
780 		IEEE80211_NODE_UNLOCK(nt);
781 	}
782 
783 	/*
784 	 * Committed to selbs, setup state.
785 	 */
786 	obss = ic->ic_bss;
787 	ic->ic_bss = selbs;		/* NB: caller assumed to bump refcnt */
788 	if (obss != NULL)
789 		ieee80211_free_node(obss);
790 	/*
791 	 * Set the erp state (mostly the slot time) to deal with
792 	 * the auto-select case; this should be redundant if the
793 	 * mode is locked.
794 	 */
795 	ic->ic_curmode = ieee80211_chan2mode(ic, selbs->ni_chan);
796 	ic->ic_curchan = selbs->ni_chan;
797 	ieee80211_reset_erp(ic);
798 	ieee80211_wme_initparams(ic);
799 
800 	if (ic->ic_opmode == IEEE80211_M_STA)
801 		ieee80211_new_state(ic, IEEE80211_S_AUTH, -1);
802 	else
803 		ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
804 	return 1;
805 }
806 
807 /*
808  * Leave the specified IBSS/BSS network.  The node is assumed to
809  * be passed in with a held reference.
810  */
811 void
812 ieee80211_sta_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
813 {
814 	ic->ic_node_cleanup(ni);
815 	ieee80211_notify_node_leave(ic, ni);
816 }
817 
818 static struct ieee80211_node *
819 node_alloc(struct ieee80211_node_table *nt)
820 {
821 	struct ieee80211_node *ni;
822 
823 	MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node),
824 		M_80211_NODE, M_NOWAIT | M_ZERO);
825 	return ni;
826 }
827 
828 /*
829  * Reclaim any resources in a node and reset any critical
830  * state.  Typically nodes are free'd immediately after,
831  * but in some cases the storage may be reused so we need
832  * to insure consistent state (should probably fix that).
833  */
834 static void
835 node_cleanup(struct ieee80211_node *ni)
836 {
837 #define	N(a)	(sizeof(a)/sizeof(a[0]))
838 	struct ieee80211com *ic = ni->ni_ic;
839 	int i, qlen;
840 
841 	/* NB: preserve ni_table */
842 	if (ni->ni_flags & IEEE80211_NODE_PWR_MGT) {
843 		ic->ic_ps_sta--;
844 		ni->ni_flags &= ~IEEE80211_NODE_PWR_MGT;
845 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER,
846 		    "[%s] power save mode off, %u sta's in ps mode\n",
847 		    ether_sprintf(ni->ni_macaddr), ic->ic_ps_sta);
848 	}
849 	/*
850 	 * Clear AREF flag that marks the authorization refcnt bump
851 	 * has happened.  This is probably not needed as the node
852 	 * should always be removed from the table so not found but
853 	 * do it just in case.
854 	 */
855 	ni->ni_flags &= ~IEEE80211_NODE_AREF;
856 
857 	/*
858 	 * Drain power save queue and, if needed, clear TIM.
859 	 */
860 	IEEE80211_NODE_SAVEQ_DRAIN(ni, qlen);
861 	if (qlen != 0 && ic->ic_set_tim != NULL)
862 		ic->ic_set_tim(ni, 0);
863 
864 	ni->ni_associd = 0;
865 	if (ni->ni_challenge != NULL) {
866 		FREE(ni->ni_challenge, M_DEVBUF);
867 		ni->ni_challenge = NULL;
868 	}
869 	/*
870 	 * Preserve SSID, WPA, and WME ie's so the bss node is
871 	 * reusable during a re-auth/re-assoc state transition.
872 	 * If we remove these data they will not be recreated
873 	 * because they come from a probe-response or beacon frame
874 	 * which cannot be expected prior to the association-response.
875 	 * This should not be an issue when operating in other modes
876 	 * as stations leaving always go through a full state transition
877 	 * which will rebuild this state.
878 	 *
879 	 * XXX does this leave us open to inheriting old state?
880 	 */
881 	for (i = 0; i < N(ni->ni_rxfrag); i++)
882 		if (ni->ni_rxfrag[i] != NULL) {
883 			m_freem(ni->ni_rxfrag[i]);
884 			ni->ni_rxfrag[i] = NULL;
885 		}
886 	/*
887 	 * Must be careful here to remove any key map entry w/o a LOR.
888 	 */
889 	ieee80211_node_delucastkey(ni);
890 #undef N
891 }
892 
893 static void
894 node_free(struct ieee80211_node *ni)
895 {
896 	struct ieee80211com *ic = ni->ni_ic;
897 
898 	ic->ic_node_cleanup(ni);
899 	if (ni->ni_wpa_ie != NULL)
900 		FREE(ni->ni_wpa_ie, M_DEVBUF);
901 	if (ni->ni_wme_ie != NULL)
902 		FREE(ni->ni_wme_ie, M_DEVBUF);
903 	IEEE80211_NODE_SAVEQ_DESTROY(ni);
904 	FREE(ni, M_80211_NODE);
905 }
906 
907 static u_int8_t
908 node_getrssi(const struct ieee80211_node *ni)
909 {
910 	return ni->ni_rssi;
911 }
912 
913 static void
914 ieee80211_setup_node(struct ieee80211_node_table *nt,
915 	struct ieee80211_node *ni, const u_int8_t *macaddr)
916 {
917 	struct ieee80211com *ic = nt->nt_ic;
918 	int hash;
919 
920 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
921 		"%s %p<%s> in %s table\n", __func__, ni,
922 		ether_sprintf(macaddr), nt->nt_name);
923 
924 	IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
925 	hash = IEEE80211_NODE_HASH(macaddr);
926 	ieee80211_node_initref(ni);		/* mark referenced */
927 	ni->ni_chan = IEEE80211_CHAN_ANYC;
928 	ni->ni_authmode = IEEE80211_AUTH_OPEN;
929 	ni->ni_txpower = ic->ic_txpowlimit;	/* max power */
930 	ieee80211_crypto_resetkey(ic, &ni->ni_ucastkey, IEEE80211_KEYIX_NONE);
931 	ni->ni_inact_reload = nt->nt_inact_init;
932 	ni->ni_inact = ni->ni_inact_reload;
933 	IEEE80211_NODE_SAVEQ_INIT(ni, "unknown");
934 
935 	IEEE80211_NODE_LOCK(nt);
936 	TAILQ_INSERT_TAIL(&nt->nt_node, ni, ni_list);
937 	LIST_INSERT_HEAD(&nt->nt_hash[hash], ni, ni_hash);
938 	ni->ni_table = nt;
939 	ni->ni_ic = ic;
940 	IEEE80211_NODE_UNLOCK(nt);
941 }
942 
943 struct ieee80211_node *
944 ieee80211_alloc_node(struct ieee80211_node_table *nt, const u_int8_t *macaddr)
945 {
946 	struct ieee80211com *ic = nt->nt_ic;
947 	struct ieee80211_node *ni;
948 
949 	ni = ic->ic_node_alloc(nt);
950 	if (ni != NULL)
951 		ieee80211_setup_node(nt, ni, macaddr);
952 	else
953 		ic->ic_stats.is_rx_nodealloc++;
954 	return ni;
955 }
956 
957 /*
958  * Craft a temporary node suitable for sending a management frame
959  * to the specified station.  We craft only as much state as we
960  * need to do the work since the node will be immediately reclaimed
961  * once the send completes.
962  */
963 struct ieee80211_node *
964 ieee80211_tmp_node(struct ieee80211com *ic, const u_int8_t *macaddr)
965 {
966 	struct ieee80211_node *ni;
967 
968 	ni = ic->ic_node_alloc(&ic->ic_sta);
969 	if (ni != NULL) {
970 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
971 			"%s %p<%s>\n", __func__, ni, ether_sprintf(macaddr));
972 
973 		IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
974 		IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid);
975 		ieee80211_node_initref(ni);		/* mark referenced */
976 		ni->ni_txpower = ic->ic_bss->ni_txpower;
977 		/* NB: required by ieee80211_fix_rate */
978 		ieee80211_set_chan(ic, ni, ic->ic_bss->ni_chan);
979 		ieee80211_crypto_resetkey(ic, &ni->ni_ucastkey,
980 			IEEE80211_KEYIX_NONE);
981 		/* XXX optimize away */
982 		IEEE80211_NODE_SAVEQ_INIT(ni, "unknown");
983 
984 		ni->ni_table = NULL;		/* NB: pedantic */
985 		ni->ni_ic = ic;
986 	} else {
987 		/* XXX msg */
988 		ic->ic_stats.is_rx_nodealloc++;
989 	}
990 	return ni;
991 }
992 
993 struct ieee80211_node *
994 ieee80211_dup_bss(struct ieee80211_node_table *nt, const u_int8_t *macaddr)
995 {
996 	struct ieee80211com *ic = nt->nt_ic;
997 	struct ieee80211_node *ni;
998 
999 	ni = ic->ic_node_alloc(nt);
1000 	if (ni != NULL) {
1001 		ieee80211_setup_node(nt, ni, macaddr);
1002 		/*
1003 		 * Inherit from ic_bss.
1004 		 */
1005 		ni->ni_authmode = ic->ic_bss->ni_authmode;
1006 		ni->ni_txpower = ic->ic_bss->ni_txpower;
1007 		ni->ni_vlan = ic->ic_bss->ni_vlan;	/* XXX?? */
1008 		IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid);
1009 		ieee80211_set_chan(ic, ni, ic->ic_bss->ni_chan);
1010 		ni->ni_rsn = ic->ic_bss->ni_rsn;
1011 	} else
1012 		ic->ic_stats.is_rx_nodealloc++;
1013 	return ni;
1014 }
1015 
1016 static struct ieee80211_node *
1017 #ifdef IEEE80211_DEBUG_REFCNT
1018 _ieee80211_find_node_debug(struct ieee80211_node_table *nt,
1019 	const u_int8_t *macaddr, const char *func, int line)
1020 #else
1021 _ieee80211_find_node(struct ieee80211_node_table *nt,
1022 	const u_int8_t *macaddr)
1023 #endif
1024 {
1025 	struct ieee80211_node *ni;
1026 	int hash;
1027 
1028 	IEEE80211_NODE_LOCK_ASSERT(nt);
1029 
1030 	hash = IEEE80211_NODE_HASH(macaddr);
1031 	LIST_FOREACH(ni, &nt->nt_hash[hash], ni_hash) {
1032 		if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) {
1033 			ieee80211_ref_node(ni);	/* mark referenced */
1034 #ifdef IEEE80211_DEBUG_REFCNT
1035 			IEEE80211_DPRINTF(nt->nt_ic, IEEE80211_MSG_NODE,
1036 			    "%s (%s:%u) %p<%s> refcnt %d\n", __func__,
1037 			    func, line,
1038 			    ni, ether_sprintf(ni->ni_macaddr),
1039 			    ieee80211_node_refcnt(ni));
1040 #endif
1041 			return ni;
1042 		}
1043 	}
1044 	return NULL;
1045 }
1046 #ifdef IEEE80211_DEBUG_REFCNT
1047 #define	_ieee80211_find_node(nt, mac) \
1048 	_ieee80211_find_node_debug(nt, mac, func, line)
1049 #endif
1050 
1051 struct ieee80211_node *
1052 #ifdef IEEE80211_DEBUG_REFCNT
1053 ieee80211_find_node_debug(struct ieee80211_node_table *nt,
1054 	const u_int8_t *macaddr, const char *func, int line)
1055 #else
1056 ieee80211_find_node(struct ieee80211_node_table *nt, const u_int8_t *macaddr)
1057 #endif
1058 {
1059 	struct ieee80211_node *ni;
1060 
1061 	IEEE80211_NODE_LOCK(nt);
1062 	ni = _ieee80211_find_node(nt, macaddr);
1063 	IEEE80211_NODE_UNLOCK(nt);
1064 	return ni;
1065 }
1066 
1067 /*
1068  * Fake up a node; this handles node discovery in adhoc mode.
1069  * Note that for the driver's benefit we we treat this like
1070  * an association so the driver has an opportunity to setup
1071  * it's private state.
1072  */
1073 struct ieee80211_node *
1074 ieee80211_fakeup_adhoc_node(struct ieee80211_node_table *nt,
1075 	const u_int8_t macaddr[IEEE80211_ADDR_LEN])
1076 {
1077 	struct ieee80211com *ic = nt->nt_ic;
1078 	struct ieee80211_node *ni;
1079 
1080 	ni = ieee80211_dup_bss(nt, macaddr);
1081 	if (ni != NULL) {
1082 		/* XXX no rate negotiation; just dup */
1083 		ni->ni_rates = ic->ic_bss->ni_rates;
1084 		if (ic->ic_newassoc != NULL)
1085 			ic->ic_newassoc(ni, 1);
1086 		/* XXX not right for 802.1x/WPA */
1087 		ieee80211_node_authorize(ni);
1088 	}
1089 	return ni;
1090 }
1091 
1092 #ifdef IEEE80211_DEBUG
1093 static void
1094 dump_probe_beacon(u_int8_t subtype, int isnew,
1095 	const u_int8_t mac[IEEE80211_ADDR_LEN],
1096 	const struct ieee80211_scanparams *sp)
1097 {
1098 
1099 	printf("[%s] %s%s on chan %u (bss chan %u) ",
1100 	    ether_sprintf(mac), isnew ? "new " : "",
1101 	    ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT],
1102 	    sp->chan, sp->bchan);
1103 	ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
1104 	printf("\n");
1105 
1106 	if (isnew) {
1107 		printf("[%s] caps 0x%x bintval %u erp 0x%x",
1108 			ether_sprintf(mac), sp->capinfo, sp->bintval, sp->erp);
1109 		if (sp->country != NULL) {
1110 #ifdef __FreeBSD__
1111 			printf(" country info %*D",
1112 				sp->country[1], sp->country+2, " ");
1113 #else
1114 			int i;
1115 			printf(" country info");
1116 			for (i = 0; i < sp->country[1]; i++)
1117 				printf(" %02x", sp->country[i+2]);
1118 #endif
1119 		}
1120 		printf("\n");
1121 	}
1122 }
1123 #endif /* IEEE80211_DEBUG */
1124 
1125 static void
1126 saveie(u_int8_t **iep, const u_int8_t *ie)
1127 {
1128 
1129 	if (ie == NULL)
1130 		*iep = NULL;
1131 	else
1132 		ieee80211_saveie(iep, ie);
1133 }
1134 
1135 /*
1136  * Process a beacon or probe response frame.
1137  */
1138 void
1139 ieee80211_add_scan(struct ieee80211com *ic,
1140 	const struct ieee80211_scanparams *sp,
1141 	const struct ieee80211_frame *wh,
1142 	int subtype, int rssi, int rstamp)
1143 {
1144 #define	ISPROBE(_st)	((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
1145 	struct ieee80211_node_table *nt = &ic->ic_scan;
1146 	struct ieee80211_node *ni;
1147 	int newnode = 0;
1148 
1149 	ni = ieee80211_find_node(nt, wh->i_addr2);
1150 	if (ni == NULL) {
1151 		/*
1152 		 * Create a new entry.
1153 		 */
1154 		ni = ic->ic_node_alloc(nt);
1155 		if (ni == NULL) {
1156 			ic->ic_stats.is_rx_nodealloc++;
1157 			return;
1158 		}
1159 		ieee80211_setup_node(nt, ni, wh->i_addr2);
1160 		/*
1161 		 * XXX inherit from ic_bss.
1162 		 */
1163 		ni->ni_authmode = ic->ic_bss->ni_authmode;
1164 		ni->ni_txpower = ic->ic_bss->ni_txpower;
1165 		ni->ni_vlan = ic->ic_bss->ni_vlan;	/* XXX?? */
1166 		ieee80211_set_chan(ic, ni, ic->ic_curchan);
1167 		ni->ni_rsn = ic->ic_bss->ni_rsn;
1168 		newnode = 1;
1169 	}
1170 #ifdef IEEE80211_DEBUG
1171 	if (ieee80211_msg_scan(ic) && (ic->ic_flags & IEEE80211_F_SCAN))
1172 		dump_probe_beacon(subtype, newnode, wh->i_addr2, sp);
1173 #endif
1174 	/* XXX ap beaconing multiple ssid w/ same bssid */
1175 	if (sp->ssid[1] != 0 &&
1176 	    (ISPROBE(subtype) || ni->ni_esslen == 0)) {
1177 		ni->ni_esslen = sp->ssid[1];
1178 		memset(ni->ni_essid, 0, sizeof(ni->ni_essid));
1179 		memcpy(ni->ni_essid, sp->ssid + 2, sp->ssid[1]);
1180 	}
1181 	ni->ni_scangen = ic->ic_scan.nt_scangen;
1182 	IEEE80211_ADDR_COPY(ni->ni_bssid, wh->i_addr3);
1183 	ni->ni_rssi = rssi;
1184 	ni->ni_rstamp = rstamp;
1185 	memcpy(ni->ni_tstamp.data, sp->tstamp, sizeof(ni->ni_tstamp));
1186 	ni->ni_intval = sp->bintval;
1187 	ni->ni_capinfo = sp->capinfo;
1188 	ni->ni_chan = &ic->ic_channels[sp->chan];
1189 	ni->ni_fhdwell = sp->fhdwell;
1190 	ni->ni_fhindex = sp->fhindex;
1191 	ni->ni_erp = sp->erp;
1192 	if (sp->tim != NULL) {
1193 		struct ieee80211_tim_ie *ie =
1194 		    (struct ieee80211_tim_ie *) sp->tim;
1195 
1196 		ni->ni_dtim_count = ie->tim_count;
1197 		ni->ni_dtim_period = ie->tim_period;
1198 	}
1199 	/*
1200 	 * Record the byte offset from the mac header to
1201 	 * the start of the TIM information element for
1202 	 * use by hardware and/or to speedup software
1203 	 * processing of beacon frames.
1204 	 */
1205 	ni->ni_timoff = sp->timoff;
1206 	/*
1207 	 * Record optional information elements that might be
1208 	 * used by applications or drivers.
1209 	 */
1210 	saveie(&ni->ni_wme_ie, sp->wme);
1211 	saveie(&ni->ni_wpa_ie, sp->wpa);
1212 
1213 	/* NB: must be after ni_chan is setup */
1214 	ieee80211_setup_rates(ni, sp->rates, sp->xrates, IEEE80211_F_DOSORT);
1215 
1216 	if (!newnode)
1217 		ieee80211_free_node(ni);
1218 #undef ISPROBE
1219 }
1220 
1221 /*
1222  * Do node discovery in adhoc mode on receipt of a beacon
1223  * or probe response frame.  Note that for the driver's
1224  * benefit we we treat this like an association so the
1225  * driver has an opportunity to setup it's private state.
1226  */
1227 struct ieee80211_node *
1228 ieee80211_add_neighbor(struct ieee80211com *ic,
1229 	const struct ieee80211_frame *wh,
1230 	const struct ieee80211_scanparams *sp)
1231 {
1232 	struct ieee80211_node *ni;
1233 
1234 	ni = ieee80211_dup_bss(&ic->ic_sta, wh->i_addr2);/* XXX alloc_node? */
1235 	if (ni != NULL) {
1236 		ni->ni_esslen = sp->ssid[1];
1237 		memcpy(ni->ni_essid, sp->ssid + 2, sp->ssid[1]);
1238 		IEEE80211_ADDR_COPY(ni->ni_bssid, wh->i_addr3);
1239 		memcpy(ni->ni_tstamp.data, sp->tstamp, sizeof(ni->ni_tstamp));
1240 		ni->ni_intval = sp->bintval;
1241 		ni->ni_capinfo = sp->capinfo;
1242 		ni->ni_chan = ic->ic_bss->ni_chan;
1243 		ni->ni_fhdwell = sp->fhdwell;
1244 		ni->ni_fhindex = sp->fhindex;
1245 		ni->ni_erp = sp->erp;
1246 		ni->ni_timoff = sp->timoff;
1247 		if (sp->wme != NULL)
1248 			ieee80211_saveie(&ni->ni_wme_ie, sp->wme);
1249 		if (sp->wpa != NULL)
1250 			ieee80211_saveie(&ni->ni_wpa_ie, sp->wpa);
1251 
1252 		/* NB: must be after ni_chan is setup */
1253 		ieee80211_setup_rates(ni, sp->rates, sp->xrates, IEEE80211_F_DOSORT);
1254 
1255 		if (ic->ic_newassoc != NULL)
1256 			ic->ic_newassoc(ni, 1);
1257 		/* XXX not right for 802.1x/WPA */
1258 		ieee80211_node_authorize(ni);
1259 	}
1260 	return ni;
1261 }
1262 
1263 #define	IS_CTL(wh) \
1264 	((wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) == IEEE80211_FC0_TYPE_CTL)
1265 #define	IS_PSPOLL(wh) \
1266 	((wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == IEEE80211_FC0_SUBTYPE_PS_POLL)
1267 /*
1268  * Locate the node for sender, track state, and then pass the
1269  * (referenced) node up to the 802.11 layer for its use.  We
1270  * are required to pass some node so we fall back to ic_bss
1271  * when this frame is from an unknown sender.  The 802.11 layer
1272  * knows this means the sender wasn't in the node table and
1273  * acts accordingly.
1274  */
1275 struct ieee80211_node *
1276 #ifdef IEEE80211_DEBUG_REFCNT
1277 ieee80211_find_rxnode_debug(struct ieee80211com *ic,
1278 	const struct ieee80211_frame_min *wh, const char *func, int line)
1279 #else
1280 ieee80211_find_rxnode(struct ieee80211com *ic,
1281 	const struct ieee80211_frame_min *wh)
1282 #endif
1283 {
1284 	struct ieee80211_node_table *nt;
1285 	struct ieee80211_node *ni;
1286 
1287 	/* XXX may want scanned nodes in the neighbor table for adhoc */
1288 	if (ic->ic_opmode == IEEE80211_M_STA ||
1289 	    ic->ic_opmode == IEEE80211_M_MONITOR ||
1290 	    (ic->ic_flags & IEEE80211_F_SCAN))
1291 		nt = &ic->ic_scan;
1292 	else
1293 		nt = &ic->ic_sta;
1294 	/* XXX check ic_bss first in station mode */
1295 	/* XXX 4-address frames? */
1296 	IEEE80211_NODE_LOCK(nt);
1297 	if (IS_CTL(wh) && !IS_PSPOLL(wh) /*&& !IS_RTS(ah)*/)
1298 		ni = _ieee80211_find_node(nt, wh->i_addr1);
1299 	else
1300 		ni = _ieee80211_find_node(nt, wh->i_addr2);
1301 	if (ni == NULL)
1302 		ni = ieee80211_ref_node(ic->ic_bss);
1303 	IEEE80211_NODE_UNLOCK(nt);
1304 
1305 	return ni;
1306 }
1307 
1308 /*
1309  * Like ieee80211_find_rxnode but use the supplied h/w
1310  * key index as a hint to locate the node in the key
1311  * mapping table.  If an entry is present at the key
1312  * index we return it; otherwise do a normal lookup and
1313  * update the mapping table if the station has a unicast
1314  * key assigned to it.
1315  */
1316 struct ieee80211_node *
1317 #ifdef IEEE80211_DEBUG_REFCNT
1318 ieee80211_find_rxnode_withkey_debug(struct ieee80211com *ic,
1319 	const struct ieee80211_frame_min *wh, ieee80211_keyix keyix,
1320 	const char *func, int line)
1321 #else
1322 ieee80211_find_rxnode_withkey(struct ieee80211com *ic,
1323 	const struct ieee80211_frame_min *wh, ieee80211_keyix keyix)
1324 #endif
1325 {
1326 	struct ieee80211_node_table *nt;
1327 	struct ieee80211_node *ni;
1328 
1329 	if (ic->ic_opmode == IEEE80211_M_STA ||
1330 	    ic->ic_opmode == IEEE80211_M_MONITOR ||
1331 	    (ic->ic_flags & IEEE80211_F_SCAN))
1332 		nt = &ic->ic_scan;
1333 	else
1334 		nt = &ic->ic_sta;
1335 	IEEE80211_NODE_LOCK(nt);
1336 	if (nt->nt_keyixmap != NULL && keyix < nt->nt_keyixmax)
1337 		ni = nt->nt_keyixmap[keyix];
1338 	else
1339 		ni = NULL;
1340 	if (ni == NULL) {
1341 		if (IS_CTL(wh) && !IS_PSPOLL(wh) /*&& !IS_RTS(ah)*/)
1342 			ni = _ieee80211_find_node(nt, wh->i_addr1);
1343 		else
1344 			ni = _ieee80211_find_node(nt, wh->i_addr2);
1345 		if (ni == NULL)
1346 			ni = ieee80211_ref_node(ic->ic_bss);
1347 		if (nt->nt_keyixmap != NULL) {
1348 			/*
1349 			 * If the station has a unicast key cache slot
1350 			 * assigned update the key->node mapping table.
1351 			 */
1352 			keyix = ni->ni_ucastkey.wk_rxkeyix;
1353 			/* XXX can keyixmap[keyix] != NULL? */
1354 			if (keyix < nt->nt_keyixmax &&
1355 			    nt->nt_keyixmap[keyix] == NULL) {
1356 				IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_NODE,
1357 				    "%s: add key map entry %p<%s> refcnt %d\n",
1358 				    __func__, ni, ether_sprintf(ni->ni_macaddr),
1359 				    ieee80211_node_refcnt(ni)+1);
1360 				nt->nt_keyixmap[keyix] = ieee80211_ref_node(ni);
1361 			}
1362 		}
1363 	} else {
1364 		ieee80211_ref_node(ni);
1365 	}
1366 	IEEE80211_NODE_UNLOCK(nt);
1367 
1368 	return ni;
1369 }
1370 #undef IS_PSPOLL
1371 #undef IS_CTL
1372 
1373 /*
1374  * Return a reference to the appropriate node for sending
1375  * a data frame.  This handles node discovery in adhoc networks.
1376  */
1377 struct ieee80211_node *
1378 #ifdef IEEE80211_DEBUG_REFCNT
1379 ieee80211_find_txnode_debug(struct ieee80211com *ic, const u_int8_t *macaddr,
1380 	const char *func, int line)
1381 #else
1382 ieee80211_find_txnode(struct ieee80211com *ic, const u_int8_t *macaddr)
1383 #endif
1384 {
1385 	struct ieee80211_node_table *nt = &ic->ic_sta;
1386 	struct ieee80211_node *ni;
1387 
1388 	/*
1389 	 * The destination address should be in the node table
1390 	 * unless this is a multicast/broadcast frame.  We can
1391 	 * also optimize station mode operation, all frames go
1392 	 * to the bss node.
1393 	 */
1394 	/* XXX can't hold lock across dup_bss 'cuz of recursive locking */
1395 	IEEE80211_NODE_LOCK(nt);
1396 	if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr))
1397 		ni = ieee80211_ref_node(ic->ic_bss);
1398 	else
1399 		ni = _ieee80211_find_node(nt, macaddr);
1400 	IEEE80211_NODE_UNLOCK(nt);
1401 
1402 	if (ni == NULL) {
1403 		if (ic->ic_opmode == IEEE80211_M_IBSS ||
1404 		    ic->ic_opmode == IEEE80211_M_AHDEMO) {
1405 			/*
1406 			 * In adhoc mode cons up a node for the destination.
1407 			 * Note that we need an additional reference for the
1408 			 * caller to be consistent with _ieee80211_find_node.
1409 			 */
1410 			ni = ieee80211_fakeup_adhoc_node(nt, macaddr);
1411 			if (ni != NULL)
1412 				(void) ieee80211_ref_node(ni);
1413 		} else {
1414 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_OUTPUT,
1415 				"[%s] no node, discard frame (%s)\n",
1416 				ether_sprintf(macaddr), __func__);
1417 			ic->ic_stats.is_tx_nonode++;
1418 		}
1419 	}
1420 	return ni;
1421 }
1422 
1423 /*
1424  * Like find but search based on the channel too.
1425  */
1426 struct ieee80211_node *
1427 #ifdef IEEE80211_DEBUG_REFCNT
1428 ieee80211_find_node_with_channel_debug(struct ieee80211_node_table *nt,
1429 	const u_int8_t *macaddr, struct ieee80211_channel *chan,
1430 	const char *func, int line)
1431 #else
1432 ieee80211_find_node_with_channel(struct ieee80211_node_table *nt,
1433 	const u_int8_t *macaddr, struct ieee80211_channel *chan)
1434 #endif
1435 {
1436 	struct ieee80211_node *ni;
1437 	int hash;
1438 
1439 	hash = IEEE80211_NODE_HASH(macaddr);
1440 	IEEE80211_NODE_LOCK(nt);
1441 	LIST_FOREACH(ni, &nt->nt_hash[hash], ni_hash) {
1442 		if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) &&
1443 		    ni->ni_chan == chan) {
1444 			ieee80211_ref_node(ni);		/* mark referenced */
1445 			IEEE80211_DPRINTF(nt->nt_ic, IEEE80211_MSG_NODE,
1446 #ifdef IEEE80211_DEBUG_REFCNT
1447 			    "%s (%s:%u) %p<%s> refcnt %d\n", __func__,
1448 			    func, line,
1449 #else
1450 			    "%s %p<%s> refcnt %d\n", __func__,
1451 #endif
1452 			    ni, ether_sprintf(ni->ni_macaddr),
1453 			    ieee80211_node_refcnt(ni));
1454 			break;
1455 		}
1456 	}
1457 	IEEE80211_NODE_UNLOCK(nt);
1458 	return ni;
1459 }
1460 
1461 /*
1462  * Like find but search based on the ssid too.
1463  */
1464 struct ieee80211_node *
1465 #ifdef IEEE80211_DEBUG_REFCNT
1466 ieee80211_find_node_with_ssid_debug(struct ieee80211_node_table *nt,
1467 	const u_int8_t *macaddr, u_int ssidlen, const u_int8_t *ssid,
1468 	const char *func, int line)
1469 #else
1470 ieee80211_find_node_with_ssid(struct ieee80211_node_table *nt,
1471 	const u_int8_t *macaddr, u_int ssidlen, const u_int8_t *ssid)
1472 #endif
1473 {
1474 #define	MATCH_SSID(ni, ssid, ssidlen) \
1475 	(ni->ni_esslen == ssidlen && memcmp(ni->ni_essid, ssid, ssidlen) == 0)
1476 	static const u_int8_t zeromac[IEEE80211_ADDR_LEN];
1477 	struct ieee80211com *ic = nt->nt_ic;
1478 	struct ieee80211_node *ni;
1479 	int hash;
1480 
1481 	IEEE80211_NODE_LOCK(nt);
1482 	/*
1483 	 * A mac address that is all zero means match only the ssid;
1484 	 * otherwise we must match both.
1485 	 */
1486 	if (IEEE80211_ADDR_EQ(macaddr, zeromac)) {
1487 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
1488 			if (MATCH_SSID(ni, ssid, ssidlen))
1489 				break;
1490 		}
1491 	} else {
1492 		hash = IEEE80211_NODE_HASH(macaddr);
1493 		LIST_FOREACH(ni, &nt->nt_hash[hash], ni_hash) {
1494 			if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) &&
1495 			    MATCH_SSID(ni, ssid, ssidlen))
1496 				break;
1497 		}
1498 	}
1499 	if (ni != NULL) {
1500 		ieee80211_ref_node(ni);	/* mark referenced */
1501 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1502 #ifdef IEEE80211_DEBUG_REFCNT
1503 		    "%s (%s:%u) %p<%s> refcnt %d\n", __func__,
1504 		    func, line,
1505 #else
1506 		    "%s %p<%s> refcnt %d\n", __func__,
1507 #endif
1508 		     ni, ether_sprintf(ni->ni_macaddr),
1509 		     ieee80211_node_refcnt(ni));
1510 	}
1511 	IEEE80211_NODE_UNLOCK(nt);
1512 	return ni;
1513 #undef MATCH_SSID
1514 }
1515 
1516 static void
1517 _ieee80211_free_node(struct ieee80211_node *ni)
1518 {
1519 	struct ieee80211com *ic = ni->ni_ic;
1520 	struct ieee80211_node_table *nt = ni->ni_table;
1521 
1522 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1523 		"%s %p<%s> in %s table\n", __func__, ni,
1524 		ether_sprintf(ni->ni_macaddr),
1525 		nt != NULL ? nt->nt_name : "<gone>");
1526 
1527 	IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
1528 	if (nt != NULL) {
1529 		TAILQ_REMOVE(&nt->nt_node, ni, ni_list);
1530 		LIST_REMOVE(ni, ni_hash);
1531 	}
1532 	ic->ic_node_free(ni);
1533 }
1534 
1535 void
1536 #ifdef IEEE80211_DEBUG_REFCNT
1537 ieee80211_free_node_debug(struct ieee80211_node *ni, const char *func, int line)
1538 #else
1539 ieee80211_free_node(struct ieee80211_node *ni)
1540 #endif
1541 {
1542 	struct ieee80211_node_table *nt = ni->ni_table;
1543 
1544 #ifdef IEEE80211_DEBUG_REFCNT
1545 	IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_NODE,
1546 		"%s (%s:%u) %p<%s> refcnt %d\n", __func__, func, line, ni,
1547 		 ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni)-1);
1548 #endif
1549 	if (nt != NULL) {
1550 		IEEE80211_NODE_LOCK(nt);
1551 		if (ieee80211_node_dectestref(ni)) {
1552 			/*
1553 			 * Last reference, reclaim state.
1554 			 */
1555 			_ieee80211_free_node(ni);
1556 		} else if (ieee80211_node_refcnt(ni) == 1 &&
1557 		    nt->nt_keyixmap != NULL) {
1558 			ieee80211_keyix keyix;
1559 			/*
1560 			 * Check for a last reference in the key mapping table.
1561 			 */
1562 			keyix = ni->ni_ucastkey.wk_rxkeyix;
1563 			if (keyix < nt->nt_keyixmax &&
1564 			    nt->nt_keyixmap[keyix] == ni) {
1565 				IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_NODE,
1566 				    "%s: %p<%s> clear key map entry", __func__,
1567 				    ni, ether_sprintf(ni->ni_macaddr));
1568 				nt->nt_keyixmap[keyix] = NULL;
1569 				ieee80211_node_decref(ni); /* XXX needed? */
1570 				_ieee80211_free_node(ni);
1571 			}
1572 		}
1573 		IEEE80211_NODE_UNLOCK(nt);
1574 	} else {
1575 		if (ieee80211_node_dectestref(ni))
1576 			_ieee80211_free_node(ni);
1577 	}
1578 }
1579 
1580 /*
1581  * Reclaim a unicast key and clear any key cache state.
1582  */
1583 int
1584 ieee80211_node_delucastkey(struct ieee80211_node *ni)
1585 {
1586 	struct ieee80211com *ic = ni->ni_ic;
1587 	struct ieee80211_node_table *nt = &ic->ic_sta;
1588 	struct ieee80211_node *nikey;
1589 	ieee80211_keyix keyix;
1590 	int isowned, status;
1591 
1592 	/*
1593 	 * NB: We must beware of LOR here; deleting the key
1594 	 * can cause the crypto layer to block traffic updates
1595 	 * which can generate a LOR against the node table lock;
1596 	 * grab it here and stash the key index for our use below.
1597 	 *
1598 	 * Must also beware of recursion on the node table lock.
1599 	 * When called from node_cleanup we may already have
1600 	 * the node table lock held.  Unfortunately there's no
1601 	 * way to separate out this path so we must do this
1602 	 * conditionally.
1603 	 */
1604 	isowned = IEEE80211_NODE_IS_LOCKED(nt);
1605 	if (!isowned)
1606 		IEEE80211_NODE_LOCK(nt);
1607 	keyix = ni->ni_ucastkey.wk_rxkeyix;
1608 	status = ieee80211_crypto_delkey(ic, &ni->ni_ucastkey);
1609 	if (nt->nt_keyixmap != NULL && keyix < nt->nt_keyixmax) {
1610 		nikey = nt->nt_keyixmap[keyix];
1611 		nt->nt_keyixmap[keyix] = NULL;;
1612 	} else
1613 		nikey = NULL;
1614 	if (!isowned)
1615 		IEEE80211_NODE_UNLOCK(&ic->ic_sta);
1616 
1617 	if (nikey != NULL) {
1618 		KASSERT(nikey == ni,
1619 			("key map out of sync, ni %p nikey %p", ni, nikey));
1620 		IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_NODE,
1621 			"%s: delete key map entry %p<%s> refcnt %d\n",
1622 			__func__, ni, ether_sprintf(ni->ni_macaddr),
1623 			ieee80211_node_refcnt(ni)-1);
1624 		ieee80211_free_node(ni);
1625 	}
1626 	return status;
1627 }
1628 
1629 /*
1630  * Reclaim a node.  If this is the last reference count then
1631  * do the normal free work.  Otherwise remove it from the node
1632  * table and mark it gone by clearing the back-reference.
1633  */
1634 static void
1635 node_reclaim(struct ieee80211_node_table *nt, struct ieee80211_node *ni)
1636 {
1637 	ieee80211_keyix keyix;
1638 
1639 	IEEE80211_NODE_LOCK_ASSERT(nt);
1640 
1641 	IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_NODE,
1642 		"%s: remove %p<%s> from %s table, refcnt %d\n",
1643 		__func__, ni, ether_sprintf(ni->ni_macaddr),
1644 		nt->nt_name, ieee80211_node_refcnt(ni)-1);
1645 	/*
1646 	 * Clear any entry in the unicast key mapping table.
1647 	 * We need to do it here so rx lookups don't find it
1648 	 * in the mapping table even if it's not in the hash
1649 	 * table.  We cannot depend on the mapping table entry
1650 	 * being cleared because the node may not be free'd.
1651 	 */
1652 	keyix = ni->ni_ucastkey.wk_rxkeyix;
1653 	if (nt->nt_keyixmap != NULL && keyix < nt->nt_keyixmax &&
1654 	    nt->nt_keyixmap[keyix] == ni) {
1655 		IEEE80211_DPRINTF(ni->ni_ic, IEEE80211_MSG_NODE,
1656 			"%s: %p<%s> clear key map entry\n",
1657 			__func__, ni, ether_sprintf(ni->ni_macaddr));
1658 		nt->nt_keyixmap[keyix] = NULL;
1659 		ieee80211_node_decref(ni);	/* NB: don't need free */
1660 	}
1661 	if (!ieee80211_node_dectestref(ni)) {
1662 		/*
1663 		 * Other references are present, just remove the
1664 		 * node from the table so it cannot be found.  When
1665 		 * the references are dropped storage will be
1666 		 * reclaimed.
1667 		 */
1668 		TAILQ_REMOVE(&nt->nt_node, ni, ni_list);
1669 		LIST_REMOVE(ni, ni_hash);
1670 		ni->ni_table = NULL;		/* clear reference */
1671 	} else
1672 		_ieee80211_free_node(ni);
1673 }
1674 
1675 static void
1676 ieee80211_free_allnodes_locked(struct ieee80211_node_table *nt)
1677 {
1678 	struct ieee80211com *ic = nt->nt_ic;
1679 	struct ieee80211_node *ni;
1680 
1681 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1682 		"%s: free all nodes in %s table\n", __func__, nt->nt_name);
1683 
1684 	while ((ni = TAILQ_FIRST(&nt->nt_node)) != NULL) {
1685 		if (ni->ni_associd != 0) {
1686 			if (ic->ic_auth->ia_node_leave != NULL)
1687 				ic->ic_auth->ia_node_leave(ic, ni);
1688 			IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
1689 		}
1690 		node_reclaim(nt, ni);
1691 	}
1692 	ieee80211_reset_erp(ic);
1693 }
1694 
1695 static void
1696 ieee80211_free_allnodes(struct ieee80211_node_table *nt)
1697 {
1698 
1699 	IEEE80211_NODE_LOCK(nt);
1700 	ieee80211_free_allnodes_locked(nt);
1701 	IEEE80211_NODE_UNLOCK(nt);
1702 }
1703 
1704 /*
1705  * Timeout entries in the scan cache.
1706  */
1707 static void
1708 ieee80211_timeout_scan_candidates(struct ieee80211_node_table *nt)
1709 {
1710 	struct ieee80211com *ic = nt->nt_ic;
1711 	struct ieee80211_node *ni, *tni;
1712 
1713 	IEEE80211_NODE_LOCK(nt);
1714 	ni = ic->ic_bss;
1715 	/* XXX belongs elsewhere */
1716 	if (ni->ni_rxfrag[0] != NULL && ticks > ni->ni_rxfragstamp + hz) {
1717 		m_freem(ni->ni_rxfrag[0]);
1718 		ni->ni_rxfrag[0] = NULL;
1719 	}
1720 	TAILQ_FOREACH_SAFE(ni, &nt->nt_node, ni_list, tni) {
1721 		if (ni->ni_inact && --ni->ni_inact == 0) {
1722 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1723 			    "[%s] scan candidate purged from cache "
1724 			    "(refcnt %u)\n", ether_sprintf(ni->ni_macaddr),
1725 			    ieee80211_node_refcnt(ni));
1726 			node_reclaim(nt, ni);
1727 		}
1728 	}
1729 	IEEE80211_NODE_UNLOCK(nt);
1730 
1731 	nt->nt_inact_timer = IEEE80211_INACT_WAIT;
1732 }
1733 
1734 /*
1735  * Timeout inactive stations and do related housekeeping.
1736  * Note that we cannot hold the node lock while sending a
1737  * frame as this would lead to a LOR.  Instead we use a
1738  * generation number to mark nodes that we've scanned and
1739  * drop the lock and restart a scan if we have to time out
1740  * a node.  Since we are single-threaded by virtue of
1741  * controlling the inactivity timer we can be sure this will
1742  * process each node only once.
1743  */
1744 static void
1745 ieee80211_timeout_stations(struct ieee80211_node_table *nt)
1746 {
1747 	struct ieee80211com *ic = nt->nt_ic;
1748 	struct ieee80211_node *ni;
1749 	u_int gen;
1750 	int isadhoc;
1751 
1752 	isadhoc = (ic->ic_opmode == IEEE80211_M_IBSS ||
1753 		   ic->ic_opmode == IEEE80211_M_AHDEMO);
1754 	IEEE80211_SCAN_LOCK(nt);
1755 	gen = nt->nt_scangen++;
1756 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
1757 		"%s: %s scangen %u\n", __func__, nt->nt_name, gen);
1758 restart:
1759 	IEEE80211_NODE_LOCK(nt);
1760 	TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
1761 		if (ni->ni_scangen == gen)	/* previously handled */
1762 			continue;
1763 		ni->ni_scangen = gen;
1764 		/*
1765 		 * Ignore entries for which have yet to receive an
1766 		 * authentication frame.  These are transient and
1767 		 * will be reclaimed when the last reference to them
1768 		 * goes away (when frame xmits complete).
1769 		 */
1770 		if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
1771 		    (ni->ni_flags & IEEE80211_NODE_AREF) == 0)
1772 			continue;
1773 		/*
1774 		 * Free fragment if not needed anymore
1775 		 * (last fragment older than 1s).
1776 		 * XXX doesn't belong here
1777 		 */
1778 		if (ni->ni_rxfrag[0] != NULL &&
1779 		    ticks > ni->ni_rxfragstamp + hz) {
1780 			m_freem(ni->ni_rxfrag[0]);
1781 			ni->ni_rxfrag[0] = NULL;
1782 		}
1783 		/*
1784 		 * Special case ourself; we may be idle for extended periods
1785 		 * of time and regardless reclaiming our state is wrong.
1786 		 */
1787 		if (ni == ic->ic_bss)
1788 			continue;
1789 		ni->ni_inact--;
1790 		if (ni->ni_associd != 0 || isadhoc) {
1791 			/*
1792 			 * Age frames on the power save queue. The
1793 			 * aging interval is 4 times the listen
1794 			 * interval specified by the station.  This
1795 			 * number is factored into the age calculations
1796 			 * when the frame is placed on the queue.  We
1797 			 * store ages as time differences we can check
1798 			 * and/or adjust only the head of the list.
1799 			 */
1800 			if (IEEE80211_NODE_SAVEQ_QLEN(ni) != 0) {
1801 				struct mbuf *m;
1802 				int discard = 0;
1803 
1804 				IEEE80211_NODE_SAVEQ_LOCK(ni);
1805 				while (IF_POLL(&ni->ni_savedq, m) != NULL &&
1806 				     M_AGE_GET(m) < IEEE80211_INACT_WAIT) {
1807 IEEE80211_DPRINTF(ic, IEEE80211_MSG_POWER, "[%s] discard frame, age %u\n", ether_sprintf(ni->ni_macaddr), M_AGE_GET(m));/*XXX*/
1808 					_IEEE80211_NODE_SAVEQ_DEQUEUE_HEAD(ni, m);
1809 					m_freem(m);
1810 					discard++;
1811 				}
1812 				if (m != NULL)
1813 					M_AGE_SUB(m, IEEE80211_INACT_WAIT);
1814 				IEEE80211_NODE_SAVEQ_UNLOCK(ni);
1815 
1816 				if (discard != 0) {
1817 					IEEE80211_DPRINTF(ic,
1818 					    IEEE80211_MSG_POWER,
1819 					    "[%s] discard %u frames for age\n",
1820 					    ether_sprintf(ni->ni_macaddr),
1821 					    discard);
1822 					IEEE80211_NODE_STAT_ADD(ni,
1823 						ps_discard, discard);
1824 					if (IEEE80211_NODE_SAVEQ_QLEN(ni) == 0)
1825 						ic->ic_set_tim(ni, 0);
1826 				}
1827 			}
1828 			/*
1829 			 * Probe the station before time it out.  We
1830 			 * send a null data frame which may not be
1831 			 * universally supported by drivers (need it
1832 			 * for ps-poll support so it should be...).
1833 			 */
1834 			if (0 < ni->ni_inact &&
1835 			    ni->ni_inact <= ic->ic_inact_probe) {
1836 				IEEE80211_NOTE(ic,
1837 				    IEEE80211_MSG_INACT | IEEE80211_MSG_NODE,
1838 				    ni, "%s",
1839 				    "probe station due to inactivity");
1840 				/*
1841 				 * Grab a reference before unlocking the table
1842 				 * so the node cannot be reclaimed before we
1843 				 * send the frame. ieee80211_send_nulldata
1844 				 * understands we've done this and reclaims the
1845 				 * ref for us as needed.
1846 				 */
1847 				ieee80211_ref_node(ni);
1848 				IEEE80211_NODE_UNLOCK(nt);
1849 				ieee80211_send_nulldata(ni);
1850 				/* XXX stat? */
1851 				goto restart;
1852 			}
1853 		}
1854 		if (ni->ni_inact <= 0) {
1855 			IEEE80211_NOTE(ic,
1856 			    IEEE80211_MSG_INACT | IEEE80211_MSG_NODE, ni,
1857 			    "station timed out due to inactivity "
1858 			    "(refcnt %u)", ieee80211_node_refcnt(ni));
1859 			/*
1860 			 * Send a deauthenticate frame and drop the station.
1861 			 * This is somewhat complicated due to reference counts
1862 			 * and locking.  At this point a station will typically
1863 			 * have a reference count of 1.  ieee80211_node_leave
1864 			 * will do a "free" of the node which will drop the
1865 			 * reference count.  But in the meantime a reference
1866 			 * wil be held by the deauth frame.  The actual reclaim
1867 			 * of the node will happen either after the tx is
1868 			 * completed or by ieee80211_node_leave.
1869 			 *
1870 			 * Separately we must drop the node lock before sending
1871 			 * in case the driver takes a lock, as this will result
1872 			 * in  LOR between the node lock and the driver lock.
1873 			 */
1874 			IEEE80211_NODE_UNLOCK(nt);
1875 			if (ni->ni_associd != 0) {
1876 				IEEE80211_SEND_MGMT(ic, ni,
1877 				    IEEE80211_FC0_SUBTYPE_DEAUTH,
1878 				    IEEE80211_REASON_AUTH_EXPIRE);
1879 			}
1880 			ieee80211_node_leave(ic, ni);
1881 			ic->ic_stats.is_node_timeout++;
1882 			goto restart;
1883 		}
1884 	}
1885 	IEEE80211_NODE_UNLOCK(nt);
1886 
1887 	IEEE80211_SCAN_UNLOCK(nt);
1888 
1889 	nt->nt_inact_timer = IEEE80211_INACT_WAIT;
1890 }
1891 
1892 void
1893 ieee80211_iterate_nodes(struct ieee80211_node_table *nt, ieee80211_iter_func *f, void *arg)
1894 {
1895 	struct ieee80211_node *ni;
1896 	u_int gen;
1897 
1898 	IEEE80211_SCAN_LOCK(nt);
1899 	gen = nt->nt_scangen++;
1900 restart:
1901 	IEEE80211_NODE_LOCK(nt);
1902 	TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
1903 		if (ni->ni_scangen != gen) {
1904 			ni->ni_scangen = gen;
1905 			(void) ieee80211_ref_node(ni);
1906 			IEEE80211_NODE_UNLOCK(nt);
1907 			(*f)(arg, ni);
1908 			ieee80211_free_node(ni);
1909 			goto restart;
1910 		}
1911 	}
1912 	IEEE80211_NODE_UNLOCK(nt);
1913 
1914 	IEEE80211_SCAN_UNLOCK(nt);
1915 }
1916 
1917 void
1918 ieee80211_dump_node(struct ieee80211_node_table *nt, struct ieee80211_node *ni)
1919 {
1920 	printf("0x%p: mac %s refcnt %d\n", ni,
1921 		ether_sprintf(ni->ni_macaddr), ieee80211_node_refcnt(ni));
1922 	printf("\tscangen %u authmode %u flags 0x%x\n",
1923 		ni->ni_scangen, ni->ni_authmode, ni->ni_flags);
1924 	printf("\tassocid 0x%x txpower %u vlan %u\n",
1925 		ni->ni_associd, ni->ni_txpower, ni->ni_vlan);
1926 	printf("\ttxseq %u rxseq %u fragno %u rxfragstamp %u\n",
1927 		ni->ni_txseqs[0],
1928 		ni->ni_rxseqs[0] >> IEEE80211_SEQ_SEQ_SHIFT,
1929 		ni->ni_rxseqs[0] & IEEE80211_SEQ_FRAG_MASK,
1930 		ni->ni_rxfragstamp);
1931 	printf("\trstamp %u rssi %u intval %u capinfo 0x%x\n",
1932 		ni->ni_rstamp, ni->ni_rssi, ni->ni_intval, ni->ni_capinfo);
1933 	printf("\tbssid %s essid \"%.*s\" channel %u:0x%x\n",
1934 		ether_sprintf(ni->ni_bssid),
1935 		ni->ni_esslen, ni->ni_essid,
1936 		ni->ni_chan->ic_freq, ni->ni_chan->ic_flags);
1937 	printf("\tfails %u inact %u txrate %u\n",
1938 		ni->ni_fails, ni->ni_inact, ni->ni_txrate);
1939 }
1940 
1941 void
1942 ieee80211_dump_nodes(struct ieee80211_node_table *nt)
1943 {
1944 	ieee80211_iterate_nodes(nt,
1945 		(ieee80211_iter_func *) ieee80211_dump_node, nt);
1946 }
1947 
1948 /*
1949  * Handle a station joining an 11g network.
1950  */
1951 static void
1952 ieee80211_node_join_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
1953 {
1954 
1955 	/*
1956 	 * Station isn't capable of short slot time.  Bump
1957 	 * the count of long slot time stations and disable
1958 	 * use of short slot time.  Note that the actual switch
1959 	 * over to long slot time use may not occur until the
1960 	 * next beacon transmission (per sec. 7.3.1.4 of 11g).
1961 	 */
1962 	if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) == 0) {
1963 		ic->ic_longslotsta++;
1964 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
1965 		    "[%s] station needs long slot time, count %d\n",
1966 		    ether_sprintf(ni->ni_macaddr), ic->ic_longslotsta);
1967 		/* XXX vap's w/ conflicting needs won't work */
1968 		ieee80211_set_shortslottime(ic, 0);
1969 	}
1970 	/*
1971 	 * If the new station is not an ERP station
1972 	 * then bump the counter and enable protection
1973 	 * if configured.
1974 	 */
1975 	if (!ieee80211_iserp_rateset(ic, &ni->ni_rates)) {
1976 		ic->ic_nonerpsta++;
1977 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
1978 		    "[%s] station is !ERP, %d non-ERP stations associated\n",
1979 		    ether_sprintf(ni->ni_macaddr), ic->ic_nonerpsta);
1980 		/*
1981 		 * If protection is configured, enable it.
1982 		 */
1983 		if (ic->ic_protmode != IEEE80211_PROT_NONE) {
1984 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
1985 			    "%s: enable use of protection\n", __func__);
1986 			ic->ic_flags |= IEEE80211_F_USEPROT;
1987 		}
1988 		/*
1989 		 * If station does not support short preamble
1990 		 * then we must enable use of Barker preamble.
1991 		 */
1992 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE) == 0) {
1993 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
1994 			    "[%s] station needs long preamble\n",
1995 			    ether_sprintf(ni->ni_macaddr));
1996 			ic->ic_flags |= IEEE80211_F_USEBARKER;
1997 			ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE;
1998 		}
1999 	} else
2000 		ni->ni_flags |= IEEE80211_NODE_ERP;
2001 }
2002 
2003 void
2004 ieee80211_node_join(struct ieee80211com *ic, struct ieee80211_node *ni, int resp)
2005 {
2006 	int newassoc;
2007 
2008 	if (ni->ni_associd == 0) {
2009 		u_int16_t aid;
2010 
2011 		/*
2012 		 * It would be good to search the bitmap
2013 		 * more efficiently, but this will do for now.
2014 		 */
2015 		for (aid = 1; aid < ic->ic_max_aid; aid++) {
2016 			if (!IEEE80211_AID_ISSET(aid,
2017 			    ic->ic_aid_bitmap))
2018 				break;
2019 		}
2020 		if (aid >= ic->ic_max_aid) {
2021 			IEEE80211_SEND_MGMT(ic, ni, resp,
2022 			    IEEE80211_REASON_ASSOC_TOOMANY);
2023 			ieee80211_node_leave(ic, ni);
2024 			return;
2025 		}
2026 		ni->ni_associd = aid | 0xc000;
2027 		IEEE80211_AID_SET(ni->ni_associd, ic->ic_aid_bitmap);
2028 		ic->ic_sta_assoc++;
2029 		newassoc = 1;
2030 		if (ic->ic_curmode == IEEE80211_MODE_11G)
2031 			ieee80211_node_join_11g(ic, ni);
2032 	} else
2033 		newassoc = 0;
2034 
2035 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG,
2036 	    "[%s] station %sassociated at aid %d: %s preamble, %s slot time%s%s\n",
2037 	    ether_sprintf(ni->ni_macaddr), newassoc ? "" : "re",
2038 	    IEEE80211_NODE_AID(ni),
2039 	    ic->ic_flags & IEEE80211_F_SHPREAMBLE ? "short" : "long",
2040 	    ic->ic_flags & IEEE80211_F_SHSLOT ? "short" : "long",
2041 	    ic->ic_flags & IEEE80211_F_USEPROT ? ", protection" : "",
2042 	    ni->ni_flags & IEEE80211_NODE_QOS ? ", QoS" : ""
2043 	);
2044 
2045 	/* give driver a chance to setup state like ni_txrate */
2046 	if (ic->ic_newassoc != NULL)
2047 		ic->ic_newassoc(ni, newassoc);
2048 	ni->ni_inact_reload = ic->ic_inact_auth;
2049 	ni->ni_inact = ni->ni_inact_reload;
2050 	IEEE80211_SEND_MGMT(ic, ni, resp, IEEE80211_STATUS_SUCCESS);
2051 	/* tell the authenticator about new station */
2052 	if (ic->ic_auth->ia_node_join != NULL)
2053 		ic->ic_auth->ia_node_join(ic, ni);
2054 	ieee80211_notify_node_join(ic, ni, newassoc);
2055 }
2056 
2057 /*
2058  * Handle a station leaving an 11g network.
2059  */
2060 static void
2061 ieee80211_node_leave_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
2062 {
2063 
2064 	KASSERT(ic->ic_curmode == IEEE80211_MODE_11G,
2065 	     ("not in 11g, bss %u:0x%x, curmode %u", ni->ni_chan->ic_freq,
2066 	      ni->ni_chan->ic_flags, ic->ic_curmode));
2067 
2068 	/*
2069 	 * If a long slot station do the slot time bookkeeping.
2070 	 */
2071 	if ((ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME) == 0) {
2072 		KASSERT(ic->ic_longslotsta > 0,
2073 		    ("bogus long slot station count %d", ic->ic_longslotsta));
2074 		ic->ic_longslotsta--;
2075 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
2076 		    "[%s] long slot time station leaves, count now %d\n",
2077 		    ether_sprintf(ni->ni_macaddr), ic->ic_longslotsta);
2078 		if (ic->ic_longslotsta == 0) {
2079 			/*
2080 			 * Re-enable use of short slot time if supported
2081 			 * and not operating in IBSS mode (per spec).
2082 			 */
2083 			if ((ic->ic_caps & IEEE80211_C_SHSLOT) &&
2084 			    ic->ic_opmode != IEEE80211_M_IBSS) {
2085 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
2086 				    "%s: re-enable use of short slot time\n",
2087 				    __func__);
2088 				ieee80211_set_shortslottime(ic, 1);
2089 			}
2090 		}
2091 	}
2092 	/*
2093 	 * If a non-ERP station do the protection-related bookkeeping.
2094 	 */
2095 	if ((ni->ni_flags & IEEE80211_NODE_ERP) == 0) {
2096 		KASSERT(ic->ic_nonerpsta > 0,
2097 		    ("bogus non-ERP station count %d", ic->ic_nonerpsta));
2098 		ic->ic_nonerpsta--;
2099 		IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
2100 		    "[%s] non-ERP station leaves, count now %d\n",
2101 		    ether_sprintf(ni->ni_macaddr), ic->ic_nonerpsta);
2102 		if (ic->ic_nonerpsta == 0) {
2103 			IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
2104 				"%s: disable use of protection\n", __func__);
2105 			ic->ic_flags &= ~IEEE80211_F_USEPROT;
2106 			/* XXX verify mode? */
2107 			if (ic->ic_caps & IEEE80211_C_SHPREAMBLE) {
2108 				IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC,
2109 				    "%s: re-enable use of short preamble\n",
2110 				    __func__);
2111 				ic->ic_flags |= IEEE80211_F_SHPREAMBLE;
2112 				ic->ic_flags &= ~IEEE80211_F_USEBARKER;
2113 			}
2114 		}
2115 	}
2116 }
2117 
2118 /*
2119  * Handle bookkeeping for station deauthentication/disassociation
2120  * when operating as an ap.
2121  */
2122 void
2123 ieee80211_node_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
2124 {
2125 	struct ieee80211_node_table *nt = ni->ni_table;
2126 
2127 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_ASSOC | IEEE80211_MSG_DEBUG,
2128 	    "[%s] station with aid %d leaves\n",
2129 	    ether_sprintf(ni->ni_macaddr), IEEE80211_NODE_AID(ni));
2130 
2131 	KASSERT(ic->ic_opmode == IEEE80211_M_HOSTAP ||
2132 		ic->ic_opmode == IEEE80211_M_IBSS ||
2133 		ic->ic_opmode == IEEE80211_M_AHDEMO,
2134 		("unexpected operating mode %u", ic->ic_opmode));
2135 	/*
2136 	 * If node wasn't previously associated all
2137 	 * we need to do is reclaim the reference.
2138 	 */
2139 	/* XXX ibss mode bypasses 11g and notification */
2140 	if (ni->ni_associd == 0)
2141 		goto done;
2142 	/*
2143 	 * Tell the authenticator the station is leaving.
2144 	 * Note that we must do this before yanking the
2145 	 * association id as the authenticator uses the
2146 	 * associd to locate it's state block.
2147 	 */
2148 	if (ic->ic_auth->ia_node_leave != NULL)
2149 		ic->ic_auth->ia_node_leave(ic, ni);
2150 	IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
2151 	ni->ni_associd = 0;
2152 	ic->ic_sta_assoc--;
2153 
2154 	if (ic->ic_curmode == IEEE80211_MODE_11G)
2155 		ieee80211_node_leave_11g(ic, ni);
2156 	/*
2157 	 * Cleanup station state.  In particular clear various
2158 	 * state that might otherwise be reused if the node
2159 	 * is reused before the reference count goes to zero
2160 	 * (and memory is reclaimed).
2161 	 */
2162 	ieee80211_sta_leave(ic, ni);
2163 done:
2164 	/*
2165 	 * Remove the node from any table it's recorded in and
2166 	 * drop the caller's reference.  Removal from the table
2167 	 * is important to insure the node is not reprocessed
2168 	 * for inactivity.
2169 	 */
2170 	if (nt != NULL) {
2171 		IEEE80211_NODE_LOCK(nt);
2172 		node_reclaim(nt, ni);
2173 		IEEE80211_NODE_UNLOCK(nt);
2174 	} else
2175 		ieee80211_free_node(ni);
2176 }
2177 
2178 u_int8_t
2179 ieee80211_getrssi(struct ieee80211com *ic)
2180 {
2181 #define	NZ(x)	((x) == 0 ? 1 : (x))
2182 	struct ieee80211_node_table *nt = &ic->ic_sta;
2183 	u_int32_t rssi_samples, rssi_total;
2184 	struct ieee80211_node *ni;
2185 
2186 	rssi_total = 0;
2187 	rssi_samples = 0;
2188 	switch (ic->ic_opmode) {
2189 	case IEEE80211_M_IBSS:		/* average of all ibss neighbors */
2190 		/* XXX locking */
2191 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list)
2192 			if (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) {
2193 				rssi_samples++;
2194 				rssi_total += ic->ic_node_getrssi(ni);
2195 			}
2196 		break;
2197 	case IEEE80211_M_AHDEMO:	/* average of all neighbors */
2198 		/* XXX locking */
2199 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list) {
2200 			rssi_samples++;
2201 			rssi_total += ic->ic_node_getrssi(ni);
2202 		}
2203 		break;
2204 	case IEEE80211_M_HOSTAP:	/* average of all associated stations */
2205 		/* XXX locking */
2206 		TAILQ_FOREACH(ni, &nt->nt_node, ni_list)
2207 			if (IEEE80211_AID(ni->ni_associd) != 0) {
2208 				rssi_samples++;
2209 				rssi_total += ic->ic_node_getrssi(ni);
2210 			}
2211 		break;
2212 	case IEEE80211_M_MONITOR:	/* XXX */
2213 	case IEEE80211_M_STA:		/* use stats from associated ap */
2214 	default:
2215 		if (ic->ic_bss != NULL)
2216 			rssi_total = ic->ic_node_getrssi(ic->ic_bss);
2217 		rssi_samples = 1;
2218 		break;
2219 	}
2220 	return rssi_total / NZ(rssi_samples);
2221 #undef NZ
2222 }
2223 
2224 /*
2225  * Indicate whether there are frames queued for a station in power-save mode.
2226  */
2227 static void
2228 ieee80211_set_tim(struct ieee80211_node *ni, int set)
2229 {
2230 	struct ieee80211com *ic = ni->ni_ic;
2231 	u_int16_t aid;
2232 
2233 	KASSERT(ic->ic_opmode == IEEE80211_M_HOSTAP ||
2234 		ic->ic_opmode == IEEE80211_M_IBSS,
2235 		("operating mode %u", ic->ic_opmode));
2236 
2237 	aid = IEEE80211_AID(ni->ni_associd);
2238 	KASSERT(aid < ic->ic_max_aid,
2239 		("bogus aid %u, max %u", aid, ic->ic_max_aid));
2240 
2241 	IEEE80211_BEACON_LOCK(ic);
2242 	if (set != (isset(ic->ic_tim_bitmap, aid) != 0)) {
2243 		if (set) {
2244 			setbit(ic->ic_tim_bitmap, aid);
2245 			ic->ic_ps_pending++;
2246 		} else {
2247 			clrbit(ic->ic_tim_bitmap, aid);
2248 			ic->ic_ps_pending--;
2249 		}
2250 		ic->ic_flags |= IEEE80211_F_TIMUPDATE;
2251 	}
2252 	IEEE80211_BEACON_UNLOCK(ic);
2253 }
2254 
2255 /*
2256  * Node table support.
2257  */
2258 
2259 static void
2260 ieee80211_node_table_init(struct ieee80211com *ic,
2261 	struct ieee80211_node_table *nt,
2262 	const char *name, int inact, int keyixmax,
2263 	void (*timeout)(struct ieee80211_node_table *))
2264 {
2265 
2266 	IEEE80211_DPRINTF(ic, IEEE80211_MSG_NODE,
2267 		"%s %s table, inact %u\n", __func__, name, inact);
2268 
2269 	nt->nt_ic = ic;
2270 	/* XXX need unit */
2271 	IEEE80211_NODE_LOCK_INIT(nt, ic->ic_ifp->if_xname);
2272 	IEEE80211_SCAN_LOCK_INIT(nt, ic->ic_ifp->if_xname);
2273 	TAILQ_INIT(&nt->nt_node);
2274 	nt->nt_name = name;
2275 	nt->nt_scangen = 1;
2276 	nt->nt_inact_init = inact;
2277 	nt->nt_timeout = timeout;
2278 	nt->nt_keyixmax = keyixmax;
2279 	if (nt->nt_keyixmax > 0) {
2280 		MALLOC(nt->nt_keyixmap, struct ieee80211_node **,
2281 			keyixmax * sizeof(struct ieee80211_node *),
2282 			M_80211_NODE, M_NOWAIT | M_ZERO);
2283 		if (nt->nt_keyixmap == NULL)
2284 			if_printf(ic->ic_ifp,
2285 			    "Cannot allocate key index map with %u entries\n",
2286 			    keyixmax);
2287 	} else
2288 		nt->nt_keyixmap = NULL;
2289 }
2290 
2291 void
2292 ieee80211_node_table_reset(struct ieee80211_node_table *nt)
2293 {
2294 
2295 	IEEE80211_DPRINTF(nt->nt_ic, IEEE80211_MSG_NODE,
2296 		"%s %s table\n", __func__, nt->nt_name);
2297 
2298 	IEEE80211_NODE_LOCK(nt);
2299 	nt->nt_inact_timer = 0;
2300 	ieee80211_free_allnodes_locked(nt);
2301 	IEEE80211_NODE_UNLOCK(nt);
2302 }
2303 
2304 static void
2305 ieee80211_node_table_cleanup(struct ieee80211_node_table *nt)
2306 {
2307 
2308 	IEEE80211_DPRINTF(nt->nt_ic, IEEE80211_MSG_NODE,
2309 		"%s %s table\n", __func__, nt->nt_name);
2310 
2311 	IEEE80211_NODE_LOCK(nt);
2312 	ieee80211_free_allnodes_locked(nt);
2313 	if (nt->nt_keyixmap != NULL) {
2314 		/* XXX verify all entries are NULL */
2315 		int i;
2316 		for (i = 0; i < nt->nt_keyixmax; i++)
2317 			if (nt->nt_keyixmap[i] != NULL)
2318 				printf("%s: %s[%u] still active\n", __func__,
2319 					nt->nt_name, i);
2320 		FREE(nt->nt_keyixmap, M_80211_NODE);
2321 		nt->nt_keyixmap = NULL;
2322 	}
2323 	IEEE80211_SCAN_LOCK_DESTROY(nt);
2324 	IEEE80211_NODE_LOCK_DESTROY(nt);
2325 }
2326