xref: /freebsd/sys/net80211/ieee80211_node.c (revision 7660b554bc59a07be0431c17e0e33815818baa69)
1 /*-
2  * Copyright (c) 2001 Atsushi Onoe
3  * Copyright (c) 2002, 2003 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 "opt_inet.h"
37 
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/mbuf.h>
41 #include <sys/malloc.h>
42 #include <sys/kernel.h>
43 #include <sys/socket.h>
44 #include <sys/sockio.h>
45 #include <sys/endian.h>
46 #include <sys/errno.h>
47 #include <sys/bus.h>
48 #include <sys/proc.h>
49 #include <sys/sysctl.h>
50 
51 #include <machine/atomic.h>
52 
53 #include <net/if.h>
54 #include <net/if_dl.h>
55 #include <net/if_media.h>
56 #include <net/if_arp.h>
57 #include <net/ethernet.h>
58 #include <net/if_llc.h>
59 
60 #include <net80211/ieee80211_var.h>
61 
62 #include <net/bpf.h>
63 
64 #ifdef INET
65 #include <netinet/in.h>
66 #include <netinet/if_ether.h>
67 #endif
68 
69 static struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *);
70 static void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *);
71 static void ieee80211_node_copy(struct ieee80211com *,
72 		struct ieee80211_node *, const struct ieee80211_node *);
73 static u_int8_t ieee80211_node_getrssi(struct ieee80211com *,
74 		struct ieee80211_node *);
75 
76 static void ieee80211_setup_node(struct ieee80211com *ic,
77 		struct ieee80211_node *ni, u_int8_t *macaddr);
78 static void _ieee80211_free_node(struct ieee80211com *,
79 		struct ieee80211_node *);
80 
81 void
82 ieee80211_node_attach(struct ifnet *ifp)
83 {
84 	struct ieee80211com *ic = (void *)ifp;
85 
86 	/* XXX need unit */
87 	mtx_init(&ic->ic_nodelock, ifp->if_name, "802.11 node table", MTX_DEF);
88 	TAILQ_INIT(&ic->ic_node);
89 	ic->ic_node_alloc = ieee80211_node_alloc;
90 	ic->ic_node_free = ieee80211_node_free;
91 	ic->ic_node_copy = ieee80211_node_copy;
92 	ic->ic_node_getrssi = ieee80211_node_getrssi;
93 }
94 
95 void
96 ieee80211_node_lateattach(struct ifnet *ifp)
97 {
98 	struct ieee80211com *ic = (void *)ifp;
99 
100 	ic->ic_bss = (*ic->ic_node_alloc)(ic);
101 	KASSERT(ic->ic_bss != NULL, ("unable to setup inital BSS node"));
102 	ic->ic_bss->ni_chan = IEEE80211_CHAN_ANYC;
103 }
104 
105 void
106 ieee80211_node_detach(struct ifnet *ifp)
107 {
108 	struct ieee80211com *ic = (void *)ifp;
109 
110 	if (ic->ic_bss != NULL)
111 		(*ic->ic_node_free)(ic, ic->ic_bss);
112 	ieee80211_free_allnodes(ic);
113 	mtx_destroy(&ic->ic_nodelock);
114 }
115 
116 /*
117  * AP scanning support.
118  */
119 
120 /*
121  * Initialize the active channel set based on the set
122  * of available channels and the current PHY mode.
123  */
124 static void
125 ieee80211_reset_scan(struct ifnet *ifp)
126 {
127 	struct ieee80211com *ic = (void *)ifp;
128 
129 	memcpy(ic->ic_chan_scan, ic->ic_chan_active,
130 		sizeof(ic->ic_chan_active));
131 	/* NB: hack, setup so next_scan starts with the first channel */
132 	if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC)
133 		ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX];
134 }
135 
136 /*
137  * Begin an active scan.
138  */
139 void
140 ieee80211_begin_scan(struct ifnet *ifp)
141 {
142 	struct ieee80211com *ic = (void *)ifp;
143 
144 	/*
145 	 * In all but hostap mode scanning starts off in
146 	 * an active mode before switching to passive.
147 	 */
148 	if (ic->ic_opmode != IEEE80211_M_HOSTAP)
149 		ic->ic_flags |= IEEE80211_F_ASCAN;
150 	if (ifp->if_flags & IFF_DEBUG)
151 		if_printf(ifp, "begin %s scan\n",
152 			(ic->ic_flags & IEEE80211_F_ASCAN) ?
153 				"active" : "passive");
154 	/*
155 	 * Clear scan state and flush any previously seen
156 	 * AP's.  Note that the latter assumes we don't act
157 	 * as both an AP and a station, otherwise we'll
158 	 * potentially flush state of stations associated
159 	 * with us.
160 	 */
161 	ieee80211_reset_scan(ifp);
162 	ieee80211_free_allnodes(ic);
163 
164 	/* Scan the next channel. */
165 	ieee80211_next_scan(ifp);
166 }
167 
168 /*
169  * Switch to the next channel marked for scanning.
170  */
171 void
172 ieee80211_next_scan(struct ifnet *ifp)
173 {
174 	struct ieee80211com *ic = (void *)ifp;
175 	struct ieee80211_channel *chan;
176 
177 	chan = ic->ic_bss->ni_chan;
178 	for (;;) {
179 		if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX])
180 			chan = &ic->ic_channels[0];
181 		if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) {
182 			/*
183 			 * Honor channels marked passive-only
184 			 * during an active scan.
185 			 */
186 			if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 ||
187 			    (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0)
188 				break;
189 		}
190 		if (chan == ic->ic_bss->ni_chan) {
191 			ieee80211_end_scan(ifp);
192 			return;
193 		}
194 	}
195 	clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan));
196 	IEEE80211_DPRINTF(("ieee80211_next_scan: chan %d->%d\n",
197 	    ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan),
198 	    ieee80211_chan2ieee(ic, chan)));
199 	ic->ic_bss->ni_chan = chan;
200 	ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
201 }
202 
203 void
204 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan)
205 {
206 	struct ieee80211_node *ni;
207 	struct ifnet *ifp = &ic->ic_if;
208 
209 	ni = ic->ic_bss;
210 	if (ifp->if_flags & IFF_DEBUG)
211 		if_printf(ifp, "creating ibss\n");
212 	ic->ic_flags |= IEEE80211_F_SIBSS;
213 	ni->ni_chan = chan;
214 	ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)];
215 	IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr);
216 	IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr);
217 	if (ic->ic_opmode == IEEE80211_M_IBSS)
218 		ni->ni_bssid[0] |= 0x02;	/* local bit for IBSS */
219 	ni->ni_esslen = ic->ic_des_esslen;
220 	memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen);
221 	ni->ni_rssi = 0;
222 	ni->ni_rstamp = 0;
223 	memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp));
224 	ni->ni_intval = ic->ic_lintval;
225 	ni->ni_capinfo = IEEE80211_CAPINFO_IBSS;
226 	if (ic->ic_flags & IEEE80211_F_WEPON)
227 		ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
228 	if (ic->ic_phytype == IEEE80211_T_FH) {
229 		ni->ni_fhdwell = 200;	/* XXX */
230 		ni->ni_fhindex = 1;
231 	}
232 	ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
233 }
234 
235 /*
236  * Complete a scan of potential channels.
237  */
238 void
239 ieee80211_end_scan(struct ifnet *ifp)
240 {
241 	struct ieee80211com *ic = (void *)ifp;
242 	struct ieee80211_node *ni, *nextbs, *selbs;
243 	u_int8_t rate;
244 	int i, fail;
245 
246 	ic->ic_flags &= ~IEEE80211_F_ASCAN;
247 	ni = TAILQ_FIRST(&ic->ic_node);
248 
249 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
250 		/* XXX off stack? */
251 		u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)];
252 		/*
253 		 * The passive scan to look for existing AP's completed,
254 		 * select a channel to camp on.  Identify the channels
255 		 * that already have one or more AP's and try to locate
256 		 * an unnoccupied one.  If that fails, pick a random
257 		 * channel from the active set.
258 		 */
259 		for (; ni != NULL; ni = nextbs) {
260 			ieee80211_ref_node(ni);
261 			nextbs = TAILQ_NEXT(ni, ni_list);
262 			setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan));
263 			ieee80211_free_node(ic, ni);
264 		}
265 		for (i = 0; i < IEEE80211_CHAN_MAX; i++)
266 			if (isset(ic->ic_chan_active, i) && isclr(occupied, i))
267 				break;
268 		if (i == IEEE80211_CHAN_MAX) {
269 			fail = arc4random() & 3;	/* random 0-3 */
270 			for (i = 0; i < IEEE80211_CHAN_MAX; i++)
271 				if (isset(ic->ic_chan_active, i) && fail-- == 0)
272 					break;
273 		}
274 		ieee80211_create_ibss(ic, &ic->ic_channels[i]);
275 		return;
276 	}
277 	if (ni == NULL) {
278 		IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__));
279   notfound:
280 		if (ic->ic_opmode == IEEE80211_M_IBSS &&
281 		    (ic->ic_flags & IEEE80211_F_IBSSON) &&
282 		    ic->ic_des_esslen != 0) {
283 			ieee80211_create_ibss(ic, ic->ic_ibss_chan);
284 			return;
285 		}
286 		/*
287 		 * Reset the list of channels to scan and start again.
288 		 */
289 		ieee80211_reset_scan(ifp);
290 		ieee80211_next_scan(ifp);
291 		return;
292 	}
293 	selbs = NULL;
294 	if (ifp->if_flags & IFF_DEBUG)
295 		if_printf(ifp, "\tmacaddr          bssid         chan  rssi rate flag  wep  essid\n");
296 	for (; ni != NULL; ni = nextbs) {
297 		ieee80211_ref_node(ni);
298 		nextbs = TAILQ_NEXT(ni, ni_list);
299 		if (ni->ni_fails) {
300 			/*
301 			 * The configuration of the access points may change
302 			 * during my scan.  So delete the entry for the AP
303 			 * and retry to associate if there is another beacon.
304 			 */
305 			if (ni->ni_fails++ > 2)
306 				ieee80211_free_node(ic, ni);
307 			continue;
308 		}
309 		fail = 0;
310 		if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
311 			fail |= 0x01;
312 		if (ic->ic_des_chan != IEEE80211_CHAN_ANYC &&
313 		    ni->ni_chan != ic->ic_des_chan)
314 			fail |= 0x01;
315 		if (ic->ic_opmode == IEEE80211_M_IBSS) {
316 			if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
317 				fail |= 0x02;
318 		} else {
319 			if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
320 				fail |= 0x02;
321 		}
322 		if (ic->ic_flags & IEEE80211_F_WEPON) {
323 			if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
324 				fail |= 0x04;
325 		} else {
326 			if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
327 				fail |= 0x04;
328 		}
329 		rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO);
330 		if (rate & IEEE80211_RATE_BASIC)
331 			fail |= 0x08;
332 		if (ic->ic_des_esslen != 0 &&
333 		    (ni->ni_esslen != ic->ic_des_esslen ||
334 		     memcmp(ni->ni_essid, ic->ic_des_essid,
335 		     ic->ic_des_esslen != 0)))
336 			fail |= 0x10;
337 		if ((ic->ic_flags & IEEE80211_F_DESBSSID) &&
338 		    !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid))
339 			fail |= 0x20;
340 		if (ifp->if_flags & IFF_DEBUG) {
341 			printf(" %c %s", fail ? '-' : '+',
342 			    ether_sprintf(ni->ni_macaddr));
343 			printf(" %s%c", ether_sprintf(ni->ni_bssid),
344 			    fail & 0x20 ? '!' : ' ');
345 			printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan),
346 				fail & 0x01 ? '!' : ' ');
347 			printf(" %+4d", ni->ni_rssi);
348 			printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
349 			    fail & 0x08 ? '!' : ' ');
350 			printf(" %4s%c",
351 			    (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
352 			    (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
353 			    "????",
354 			    fail & 0x02 ? '!' : ' ');
355 			printf(" %3s%c ",
356 			    (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
357 			    "wep" : "no",
358 			    fail & 0x04 ? '!' : ' ');
359 			ieee80211_print_essid(ni->ni_essid, ni->ni_esslen);
360 			printf("%s\n", fail & 0x10 ? "!" : "");
361 		}
362 		if (!fail) {
363 			if (selbs == NULL)
364 				selbs = ni;
365 			else if (ni->ni_rssi > selbs->ni_rssi) {
366 				ieee80211_unref_node(&selbs);
367 				selbs = ni;
368 			} else
369 				ieee80211_unref_node(&ni);
370 		} else {
371 			ieee80211_unref_node(&ni);
372 		}
373 	}
374 	if (selbs == NULL)
375 		goto notfound;
376 	(*ic->ic_node_copy)(ic, ic->ic_bss, selbs);
377 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
378 		ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE |
379 		    IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
380 		if (ic->ic_bss->ni_rates.rs_nrates == 0) {
381 			selbs->ni_fails++;
382 			ieee80211_unref_node(&selbs);
383 			goto notfound;
384 		}
385 		ieee80211_unref_node(&selbs);
386 		ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
387 	} else {
388 		ieee80211_unref_node(&selbs);
389 		ieee80211_new_state(ic, IEEE80211_S_AUTH, -1);
390 	}
391 }
392 
393 static struct ieee80211_node *
394 ieee80211_node_alloc(struct ieee80211com *ic)
395 {
396 	return malloc(sizeof(struct ieee80211_node), M_DEVBUF,
397 		M_NOWAIT | M_ZERO);
398 }
399 
400 static void
401 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni)
402 {
403 	free(ni, M_DEVBUF);
404 }
405 
406 static void
407 ieee80211_node_copy(struct ieee80211com *ic,
408 	struct ieee80211_node *dst, const struct ieee80211_node *src)
409 {
410 	*dst = *src;
411 }
412 
413 static u_int8_t
414 ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni)
415 {
416 	return ni->ni_rssi;
417 }
418 
419 static void
420 ieee80211_setup_node(struct ieee80211com *ic,
421 	struct ieee80211_node *ni, u_int8_t *macaddr)
422 {
423 	int hash;
424 
425 	IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
426 	hash = IEEE80211_NODE_HASH(macaddr);
427 	ni->ni_refcnt = 1;		/* mark referenced */
428 	mtx_lock(&ic->ic_nodelock);
429 	TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list);
430 	LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash);
431 	/*
432 	 * Note we don't enable the inactive timer when acting
433 	 * as a station.  Nodes created in this mode represent
434 	 * AP's identified while scanning.  If we time them out
435 	 * then several things happen: we can't return the data
436 	 * to users to show the list of AP's we encountered, and
437 	 * more importantly, we'll incorrectly deauthenticate
438 	 * ourself because the inactivity timer will kick us off.
439 	 */
440 	if (ic->ic_opmode != IEEE80211_M_STA)
441 		ic->ic_inact_timer = IEEE80211_INACT_WAIT;
442 	mtx_unlock(&ic->ic_nodelock);
443 }
444 
445 struct ieee80211_node *
446 ieee80211_alloc_node(struct ieee80211com *ic, u_int8_t *macaddr)
447 {
448 	struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic);
449 	if (ni != NULL)
450 		ieee80211_setup_node(ic, ni, macaddr);
451 	return ni;
452 }
453 
454 struct ieee80211_node *
455 ieee80211_dup_bss(struct ieee80211com *ic, u_int8_t *macaddr)
456 {
457 	struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic);
458 	if (ni != NULL) {
459 		memcpy(ni, ic->ic_bss, sizeof(struct ieee80211_node));
460 		ieee80211_setup_node(ic, ni, macaddr);
461 	}
462 	return ni;
463 }
464 
465 struct ieee80211_node *
466 ieee80211_find_node(struct ieee80211com *ic, u_int8_t *macaddr)
467 {
468 	struct ieee80211_node *ni;
469 	int hash;
470 
471 	hash = IEEE80211_NODE_HASH(macaddr);
472 	mtx_lock(&ic->ic_nodelock);
473 	LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) {
474 		if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) {
475 			atomic_add_int(&ni->ni_refcnt, 1); /* mark referenced */
476 			break;
477 		}
478 	}
479 	mtx_unlock(&ic->ic_nodelock);
480 	return ni;
481 }
482 
483 /*
484  * Like find but search based on the channel too.
485  */
486 struct ieee80211_node *
487 ieee80211_lookup_node(struct ieee80211com *ic,
488 	u_int8_t *macaddr, struct ieee80211_channel *chan)
489 {
490 	struct ieee80211_node *ni;
491 	int hash;
492 
493 	hash = IEEE80211_NODE_HASH(macaddr);
494 	mtx_lock(&ic->ic_nodelock);
495 	LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) {
496 		if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && ni->ni_chan == chan) {
497 			atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */
498 			break;
499 		}
500 	}
501 	mtx_unlock(&ic->ic_nodelock);
502 	return ni;
503 }
504 
505 static void
506 _ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
507 {
508 	KASSERT(ni != ic->ic_bss, ("freeing bss node"));
509 
510 	TAILQ_REMOVE(&ic->ic_node, ni, ni_list);
511 	LIST_REMOVE(ni, ni_hash);
512 	if (TAILQ_EMPTY(&ic->ic_node))
513 		ic->ic_inact_timer = 0;
514 	(*ic->ic_node_free)(ic, ni);
515 }
516 
517 void
518 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
519 {
520 	KASSERT(ni != ic->ic_bss, ("freeing ic_bss"));
521 
522 	/* XXX need equivalent of atomic_dec_and_test */
523 	atomic_subtract_int(&ni->ni_refcnt, 1);
524 	if (atomic_cmpset_int(&ni->ni_refcnt, 0, 1)) {
525 		mtx_lock(&ic->ic_nodelock);
526 		_ieee80211_free_node(ic, ni);
527 		mtx_unlock(&ic->ic_nodelock);
528 	}
529 }
530 
531 void
532 ieee80211_free_allnodes(struct ieee80211com *ic)
533 {
534 	struct ieee80211_node *ni;
535 
536 	mtx_lock(&ic->ic_nodelock);
537 	while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL)
538 		_ieee80211_free_node(ic, ni);
539 	mtx_unlock(&ic->ic_nodelock);
540 }
541 
542 void
543 ieee80211_timeout_nodes(struct ieee80211com *ic)
544 {
545 	struct ieee80211_node *ni, *nextbs;
546 
547 	mtx_lock(&ic->ic_nodelock);
548 	for (ni = TAILQ_FIRST(&ic->ic_node); ni != NULL;) {
549 		if (++ni->ni_inact > IEEE80211_INACT_MAX) {
550 			IEEE80211_DPRINTF(("station %s timed out "
551 			    "due to inactivity (%u secs)\n",
552 			    ether_sprintf(ni->ni_macaddr),
553 			    ni->ni_inact));
554 			nextbs = TAILQ_NEXT(ni, ni_list);
555 			/*
556 			 * Send a deauthenticate frame.
557 			 */
558 			IEEE80211_SEND_MGMT(ic, ni,
559 			    IEEE80211_FC0_SUBTYPE_DEAUTH,
560 			    IEEE80211_REASON_AUTH_EXPIRE);
561 			ieee80211_free_node(ic, ni);
562 			ni = nextbs;
563 		} else
564 			ni = TAILQ_NEXT(ni, ni_list);
565 	}
566 	if (!TAILQ_EMPTY(&ic->ic_node))
567 		ic->ic_inact_timer = IEEE80211_INACT_WAIT;
568 	mtx_unlock(&ic->ic_nodelock);
569 }
570 
571 void
572 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg)
573 {
574 	struct ieee80211_node *ni;
575 
576 	mtx_lock(&ic->ic_nodelock);
577 	TAILQ_FOREACH(ni, &ic->ic_node, ni_list)
578 		(*f)(arg, ni);
579 	mtx_unlock(&ic->ic_nodelock);
580 }
581