xref: /openbsd-src/sys/net80211/ieee80211_node.c (revision 850e275390052b330d93020bf619a739a3c277ac)
1 /*	$OpenBSD: ieee80211_node.c,v 1.46 2008/09/27 15:16:09 damien Exp $	*/
2 /*	$NetBSD: ieee80211_node.c,v 1.14 2004/05/09 09:18:47 dyoung Exp $	*/
3 
4 /*-
5  * Copyright (c) 2001 Atsushi Onoe
6  * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
7  * Copyright (c) 2008 Damien Bergamini
8  * All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
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 "bpfilter.h"
34 #include "bridge.h"
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 #include <sys/socket.h>
42 #include <sys/sockio.h>
43 #include <sys/endian.h>
44 #include <sys/errno.h>
45 #include <sys/proc.h>
46 #include <sys/sysctl.h>
47 #include <sys/tree.h>
48 
49 #include <net/if.h>
50 #include <net/if_dl.h>
51 #include <net/if_media.h>
52 #include <net/if_arp.h>
53 #include <net/if_llc.h>
54 
55 #if NBPFILTER > 0
56 #include <net/bpf.h>
57 #endif
58 
59 #ifdef INET
60 #include <netinet/in.h>
61 #include <netinet/if_ether.h>
62 #endif
63 
64 #if NBRIDGE > 0
65 #include <net/if_bridge.h>
66 #endif
67 
68 #include <net80211/ieee80211_var.h>
69 #include <net80211/ieee80211_priv.h>
70 
71 #include <dev/rndvar.h>
72 
73 struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *);
74 void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *);
75 void ieee80211_node_copy(struct ieee80211com *, struct ieee80211_node *,
76     const struct ieee80211_node *);
77 void ieee80211_choose_rsnparams(struct ieee80211com *);
78 u_int8_t ieee80211_node_getrssi(struct ieee80211com *,
79     const struct ieee80211_node *);
80 void ieee80211_setup_node(struct ieee80211com *, struct ieee80211_node *,
81     const u_int8_t *);
82 void ieee80211_free_node(struct ieee80211com *, struct ieee80211_node *);
83 struct ieee80211_node *ieee80211_alloc_node_helper(struct ieee80211com *);
84 void ieee80211_node_cleanup(struct ieee80211com *, struct ieee80211_node *);
85 void ieee80211_needs_auth(struct ieee80211com *, struct ieee80211_node *);
86 #ifndef IEEE80211_STA_ONLY
87 void ieee80211_node_join_rsn(struct ieee80211com *, struct ieee80211_node *);
88 void ieee80211_node_join_11g(struct ieee80211com *, struct ieee80211_node *);
89 void ieee80211_node_leave_rsn(struct ieee80211com *, struct ieee80211_node *);
90 void ieee80211_node_leave_11g(struct ieee80211com *, struct ieee80211_node *);
91 void ieee80211_set_tim(struct ieee80211com *, int, int);
92 #endif
93 
94 #define M_80211_NODE	M_DEVBUF
95 
96 void
97 ieee80211_node_attach(struct ifnet *ifp)
98 {
99 	struct ieee80211com *ic = (void *)ifp;
100 #ifndef IEEE80211_STA_ONLY
101 	int size;
102 #endif
103 
104 	RB_INIT(&ic->ic_tree);
105 	ic->ic_node_alloc = ieee80211_node_alloc;
106 	ic->ic_node_free = ieee80211_node_free;
107 	ic->ic_node_copy = ieee80211_node_copy;
108 	ic->ic_node_getrssi = ieee80211_node_getrssi;
109 	ic->ic_scangen = 1;
110 	ic->ic_max_nnodes = ieee80211_cache_size;
111 
112 	if (ic->ic_max_aid == 0)
113 		ic->ic_max_aid = IEEE80211_AID_DEF;
114 	else if (ic->ic_max_aid > IEEE80211_AID_MAX)
115 		ic->ic_max_aid = IEEE80211_AID_MAX;
116 #ifndef IEEE80211_STA_ONLY
117 	size = howmany(ic->ic_max_aid, 32) * sizeof(u_int32_t);
118 	ic->ic_aid_bitmap = malloc(size, M_DEVBUF, M_NOWAIT | M_ZERO);
119 	if (ic->ic_aid_bitmap == NULL) {
120 		/* XXX no way to recover */
121 		printf("%s: no memory for AID bitmap!\n", __func__);
122 		ic->ic_max_aid = 0;
123 	}
124 	if (ic->ic_caps & (IEEE80211_C_HOSTAP | IEEE80211_C_IBSS)) {
125 		ic->ic_tim_len = howmany(ic->ic_max_aid, 8);
126 		ic->ic_tim_bitmap = malloc(ic->ic_tim_len, M_DEVBUF,
127 		    M_NOWAIT | M_ZERO);
128 		if (ic->ic_tim_bitmap == NULL) {
129 			printf("%s: no memory for TIM bitmap!\n", __func__);
130 			ic->ic_tim_len = 0;
131 		} else
132 			ic->ic_set_tim = ieee80211_set_tim;
133 		timeout_set(&ic->ic_rsn_timeout,
134 		    ieee80211_gtk_rekey_timeout, ic);
135 	}
136 #endif
137 }
138 
139 struct ieee80211_node *
140 ieee80211_alloc_node_helper(struct ieee80211com *ic)
141 {
142 	struct ieee80211_node *ni;
143 	if (ic->ic_nnodes >= ic->ic_max_nnodes)
144 		ieee80211_clean_nodes(ic);
145 	if (ic->ic_nnodes >= ic->ic_max_nnodes)
146 		return NULL;
147 	ni = (*ic->ic_node_alloc)(ic);
148 	if (ni != NULL)
149 		ic->ic_nnodes++;
150 	return ni;
151 }
152 
153 void
154 ieee80211_node_lateattach(struct ifnet *ifp)
155 {
156 	struct ieee80211com *ic = (void *)ifp;
157 	struct ieee80211_node *ni;
158 
159 	ni = ieee80211_alloc_node_helper(ic);
160 	if (ni == NULL)
161 		panic("unable to setup inital BSS node");
162 	ni->ni_chan = IEEE80211_CHAN_ANYC;
163 	ic->ic_bss = ieee80211_ref_node(ni);
164 	ic->ic_txpower = IEEE80211_TXPOWER_MAX;
165 }
166 
167 void
168 ieee80211_node_detach(struct ifnet *ifp)
169 {
170 	struct ieee80211com *ic = (void *)ifp;
171 
172 	if (ic->ic_bss != NULL) {
173 		(*ic->ic_node_free)(ic, ic->ic_bss);
174 		ic->ic_bss = NULL;
175 	}
176 	ieee80211_free_allnodes(ic);
177 	if (ic->ic_aid_bitmap != NULL)
178 		free(ic->ic_aid_bitmap, M_DEVBUF);
179 	if (ic->ic_tim_bitmap != NULL)
180 		free(ic->ic_tim_bitmap, M_DEVBUF);
181 }
182 
183 /*
184  * AP scanning support.
185  */
186 
187 /*
188  * Initialize the active channel set based on the set
189  * of available channels and the current PHY mode.
190  */
191 void
192 ieee80211_reset_scan(struct ifnet *ifp)
193 {
194 	struct ieee80211com *ic = (void *)ifp;
195 
196 	memcpy(ic->ic_chan_scan, ic->ic_chan_active,
197 		sizeof(ic->ic_chan_active));
198 	/* NB: hack, setup so next_scan starts with the first channel */
199 	if (ic->ic_bss != NULL && ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC)
200 		ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX];
201 }
202 
203 /*
204  * Begin an active scan.
205  */
206 void
207 ieee80211_begin_scan(struct ifnet *ifp)
208 {
209 	struct ieee80211com *ic = (void *)ifp;
210 
211 	if (ic->ic_scan_lock & IEEE80211_SCAN_LOCKED)
212 		return;
213 	ic->ic_scan_lock |= IEEE80211_SCAN_LOCKED;
214 
215 	/*
216 	 * In all but hostap mode scanning starts off in
217 	 * an active mode before switching to passive.
218 	 */
219 #ifndef IEEE80211_STA_ONLY
220 	if (ic->ic_opmode != IEEE80211_M_HOSTAP)
221 #endif
222 	{
223 		ic->ic_flags |= IEEE80211_F_ASCAN;
224 		ic->ic_stats.is_scan_active++;
225 	}
226 #ifndef IEEE80211_STA_ONLY
227 	else
228 		ic->ic_stats.is_scan_passive++;
229 #endif
230 	if (ifp->if_flags & IFF_DEBUG)
231 		printf("%s: begin %s scan\n", ifp->if_xname,
232 			(ic->ic_flags & IEEE80211_F_ASCAN) ?
233 				"active" : "passive");
234 
235 	/*
236 	 * Flush any previously seen AP's. Note that the latter
237 	 * assumes we don't act as both an AP and a station,
238 	 * otherwise we'll potentially flush state of stations
239 	 * associated with us.
240 	 */
241 	ieee80211_free_allnodes(ic);
242 
243 	/*
244 	 * Reset the current mode. Setting the current mode will also
245 	 * reset scan state.
246 	 */
247 	if (IFM_MODE(ic->ic_media.ifm_cur->ifm_media) == IFM_AUTO)
248 		ic->ic_curmode = IEEE80211_MODE_AUTO;
249 	ieee80211_setmode(ic, ic->ic_curmode);
250 
251 	ic->ic_scan_count = 0;
252 
253 	/* Scan the next channel. */
254 	ieee80211_next_scan(ifp);
255 }
256 
257 /*
258  * Switch to the next channel marked for scanning.
259  */
260 void
261 ieee80211_next_scan(struct ifnet *ifp)
262 {
263 	struct ieee80211com *ic = (void *)ifp;
264 	struct ieee80211_channel *chan;
265 
266 	chan = ic->ic_bss->ni_chan;
267 	for (;;) {
268 		if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX])
269 			chan = &ic->ic_channels[0];
270 		if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) {
271 			/*
272 			 * Ignore channels marked passive-only
273 			 * during an active scan.
274 			 */
275 			if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 ||
276 			    (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0)
277 				break;
278 		}
279 		if (chan == ic->ic_bss->ni_chan) {
280 			ieee80211_end_scan(ifp);
281 			return;
282 		}
283 	}
284 	clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan));
285 	DPRINTF(("chan %d->%d\n",
286 	    ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan),
287 	    ieee80211_chan2ieee(ic, chan)));
288 	ic->ic_bss->ni_chan = chan;
289 	ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
290 }
291 
292 #ifndef IEEE80211_STA_ONLY
293 void
294 ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan)
295 {
296 	struct ieee80211_node *ni;
297 	struct ifnet *ifp = &ic->ic_if;
298 
299 	ni = ic->ic_bss;
300 	if (ifp->if_flags & IFF_DEBUG)
301 		printf("%s: creating ibss\n", ifp->if_xname);
302 	ic->ic_flags |= IEEE80211_F_SIBSS;
303 	ni->ni_chan = chan;
304 	ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)];
305 	IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr);
306 	IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr);
307 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
308 		if ((ic->ic_flags & IEEE80211_F_DESBSSID) != 0)
309 			IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_des_bssid);
310 		else
311 			ni->ni_bssid[0] |= 0x02;	/* local bit for IBSS */
312 	}
313 	ni->ni_esslen = ic->ic_des_esslen;
314 	memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen);
315 	ni->ni_rssi = 0;
316 	ni->ni_rstamp = 0;
317 	memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp));
318 	ni->ni_intval = ic->ic_lintval;
319 	ni->ni_capinfo = IEEE80211_CAPINFO_IBSS;
320 	if (ic->ic_flags & IEEE80211_F_WEPON)
321 		ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
322 	if (ic->ic_flags & IEEE80211_F_RSNON) {
323 		struct ieee80211_key *k;
324 
325 		/* initialize 256-bit global key counter to a random value */
326 		arc4random_buf(ic->ic_globalcnt, EAPOL_KEY_NONCE_LEN);
327 
328 		ni->ni_rsnprotos = ic->ic_rsnprotos;
329 		ni->ni_rsnakms = ic->ic_rsnakms;
330 		ni->ni_rsnciphers = ic->ic_rsnciphers;
331 		ni->ni_rsngroupcipher = ic->ic_rsngroupcipher;
332 		ni->ni_rsngroupmgmtcipher = ic->ic_rsngroupmgmtcipher;
333 		ni->ni_rsncaps = 0;
334 		if (ic->ic_caps & IEEE80211_C_MFP) {
335 			ni->ni_rsncaps |= IEEE80211_RSNCAP_MFPC;
336 			if (ic->ic_flags & IEEE80211_F_MFPR)
337 				ni->ni_rsncaps |= IEEE80211_RSNCAP_MFPR;
338 		}
339 
340 		ic->ic_def_txkey = 1;
341 		k = &ic->ic_nw_keys[ic->ic_def_txkey];
342 		memset(k, 0, sizeof(*k));
343 		k->k_id = ic->ic_def_txkey;
344 		k->k_cipher = ni->ni_rsngroupcipher;
345 		k->k_flags = IEEE80211_KEY_GROUP | IEEE80211_KEY_TX;
346 		k->k_len = ieee80211_cipher_keylen(k->k_cipher);
347 		arc4random_buf(k->k_key, k->k_len);
348 		(*ic->ic_set_key)(ic, ni, k);	/* XXX */
349 
350 		if (ic->ic_caps & IEEE80211_C_MFP) {
351 			ic->ic_igtk_kid = 4;
352 			k = &ic->ic_nw_keys[ic->ic_igtk_kid];
353 			memset(k, 0, sizeof(*k));
354 			k->k_id = ic->ic_igtk_kid;
355 			k->k_cipher = ni->ni_rsngroupmgmtcipher;
356 			k->k_flags = IEEE80211_KEY_IGTK | IEEE80211_KEY_TX;
357 			k->k_len = 16;
358 			arc4random_buf(k->k_key, k->k_len);
359 			(*ic->ic_set_key)(ic, ni, k);	/* XXX */
360 		}
361 		/*
362 		 * In HostAP mode, multicast traffic is sent using ic_bss
363 		 * as the Tx node, so mark our node as valid so we can send
364 		 * multicast frames using the group key we've just configured.
365 		 */
366 		ni->ni_port_valid = 1;
367 		ni->ni_flags |= IEEE80211_NODE_TXPROT;
368 
369 		/* schedule a GTK/IGTK rekeying after 3600s */
370 		timeout_add(&ic->ic_rsn_timeout, 3600 * hz);
371 	}
372 	ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
373 }
374 #endif	/* IEEE80211_STA_ONLY */
375 
376 int
377 ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni)
378 {
379 	u_int8_t rate;
380 	int fail;
381 
382 	fail = 0;
383 	if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
384 		fail |= 0x01;
385 	if (ic->ic_des_chan != IEEE80211_CHAN_ANYC &&
386 	    ni->ni_chan != ic->ic_des_chan)
387 		fail |= 0x01;
388 #ifndef IEEE80211_STA_ONLY
389 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
390 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
391 			fail |= 0x02;
392 	} else
393 #endif
394 	{
395 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
396 			fail |= 0x02;
397 	}
398 	if (ic->ic_flags & (IEEE80211_F_WEPON | IEEE80211_F_RSNON)) {
399 		if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
400 			fail |= 0x04;
401 	} else {
402 		if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
403 			fail |= 0x04;
404 	}
405 
406 	rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO);
407 	if (rate & IEEE80211_RATE_BASIC)
408 		fail |= 0x08;
409 	if (ic->ic_des_esslen != 0 &&
410 	    (ni->ni_esslen != ic->ic_des_esslen ||
411 	     memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0))
412 		fail |= 0x10;
413 	if ((ic->ic_flags & IEEE80211_F_DESBSSID) &&
414 	    !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid))
415 		fail |= 0x20;
416 
417 	if (ic->ic_flags & IEEE80211_F_RSNON) {
418 		/*
419 		 * If at least one RSN IE field from the AP's RSN IE fails
420 		 * to overlap with any value the STA supports, the STA shall
421 		 * decline to associate with that AP.
422 		 */
423 		if ((ni->ni_rsnprotos & ic->ic_rsnprotos) == 0)
424 			fail |= 0x40;
425 		if ((ni->ni_rsnakms & ic->ic_rsnakms) == 0)
426 			fail |= 0x40;
427 		if ((ni->ni_rsnakms & ic->ic_rsnakms &
428 		     ~(IEEE80211_AKM_PSK | IEEE80211_AKM_SHA256_PSK)) == 0) {
429 			/* AP only supports PSK AKMPs */
430 			if (!(ic->ic_flags & IEEE80211_F_PSK))
431 				fail |= 0x40;
432 		}
433 		if ((ni->ni_rsnciphers & ic->ic_rsnciphers) == 0)
434 			fail |= 0x40;
435 
436 		/* we only support AES-128-CMAC as the IGTK cipher */
437 		if ((ni->ni_rsncaps & IEEE80211_RSNCAP_MFPC) &&
438 		    ni->ni_rsngroupmgmtcipher != IEEE80211_CIPHER_AES128_CMAC)
439 			fail |= 0x40;
440 
441 		/* we do not support MFP but AP requires it */
442 		if (!(ic->ic_caps & IEEE80211_C_MFP) &&
443 		    (ni->ni_rsncaps & IEEE80211_RSNCAP_MFPR))
444 			fail |= 0x40;
445 
446 		/* we require MFP but AP does not support it */
447 		if ((ic->ic_caps & IEEE80211_C_MFP) &&
448 		    (ic->ic_flags & IEEE80211_F_MFPR) &&
449 		    !(ni->ni_rsncaps & IEEE80211_RSNCAP_MFPC))
450 			fail |= 0x40;
451 	}
452 
453 #ifdef IEEE80211_DEBUG
454 	if (ic->ic_if.if_flags & IFF_DEBUG) {
455 		printf(" %c %s", fail ? '-' : '+',
456 		    ether_sprintf(ni->ni_macaddr));
457 		printf(" %s%c", ether_sprintf(ni->ni_bssid),
458 		    fail & 0x20 ? '!' : ' ');
459 		printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan),
460 			fail & 0x01 ? '!' : ' ');
461 		printf(" %+4d", ni->ni_rssi);
462 		printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
463 		    fail & 0x08 ? '!' : ' ');
464 		printf(" %4s%c",
465 		    (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
466 		    (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
467 		    "????",
468 		    fail & 0x02 ? '!' : ' ');
469 		printf(" %7s%c ",
470 		    (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
471 		    "privacy" : "no",
472 		    fail & 0x04 ? '!' : ' ');
473 		printf(" %3s%c ",
474 		    (ic->ic_flags & IEEE80211_F_RSNON) ?
475 		    "rsn" : "no",
476 		    fail & 0x40 ? '!' : ' ');
477 		ieee80211_print_essid(ni->ni_essid, ni->ni_esslen);
478 		printf("%s\n", fail & 0x10 ? "!" : "");
479 	}
480 #endif
481 	return fail;
482 }
483 
484 /*
485  * Complete a scan of potential channels.
486  */
487 void
488 ieee80211_end_scan(struct ifnet *ifp)
489 {
490 	struct ieee80211com *ic = (void *)ifp;
491 	struct ieee80211_node *ni, *nextbs, *selbs;
492 
493 	if (ifp->if_flags & IFF_DEBUG)
494 		printf("%s: end %s scan\n", ifp->if_xname,
495 			(ic->ic_flags & IEEE80211_F_ASCAN) ?
496 				"active" : "passive");
497 
498 	if (ic->ic_scan_count)
499 		ic->ic_flags &= ~IEEE80211_F_ASCAN;
500 
501 	ni = RB_MIN(ieee80211_tree, &ic->ic_tree);
502 
503 #ifndef IEEE80211_STA_ONLY
504 	if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
505 		/* XXX off stack? */
506 		u_char occupied[howmany(IEEE80211_CHAN_MAX, NBBY)];
507 		int i, fail;
508 
509 		/*
510 		 * The passive scan to look for existing AP's completed,
511 		 * select a channel to camp on.  Identify the channels
512 		 * that already have one or more AP's and try to locate
513 		 * an unnoccupied one.  If that fails, pick a random
514 		 * channel from the active set.
515 		 */
516 		RB_FOREACH(ni, ieee80211_tree, &ic->ic_tree)
517 			setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan));
518 		for (i = 0; i < IEEE80211_CHAN_MAX; i++)
519 			if (isset(ic->ic_chan_active, i) && isclr(occupied, i))
520 				break;
521 		if (i == IEEE80211_CHAN_MAX) {
522 			fail = arc4random() & 3;	/* random 0-3 */
523 			for (i = 0; i < IEEE80211_CHAN_MAX; i++)
524 				if (isset(ic->ic_chan_active, i) && fail-- == 0)
525 					break;
526 		}
527 		ieee80211_create_ibss(ic, &ic->ic_channels[i]);
528 		goto wakeup;
529 	}
530 #endif
531 	if (ni == NULL) {
532 		DPRINTF(("no scan candidate\n"));
533  notfound:
534 
535 #ifndef IEEE80211_STA_ONLY
536 		if (ic->ic_opmode == IEEE80211_M_IBSS &&
537 		    (ic->ic_flags & IEEE80211_F_IBSSON) &&
538 		    ic->ic_des_esslen != 0) {
539 			ieee80211_create_ibss(ic, ic->ic_ibss_chan);
540 			goto wakeup;
541 		}
542 #endif
543 		/*
544 		 * Scan the next mode if nothing has been found. This
545 		 * is necessary if the device supports different
546 		 * incompatible modes in the same channel range, like
547 		 * like 11b and "pure" 11G mode. This will loop
548 		 * forever except for user-initiated scans.
549 		 */
550 		if (ieee80211_next_mode(ifp) == IEEE80211_MODE_AUTO) {
551 			if (ic->ic_scan_lock & IEEE80211_SCAN_REQUEST &&
552 			    ic->ic_scan_lock & IEEE80211_SCAN_RESUME) {
553 				ic->ic_scan_lock = IEEE80211_SCAN_LOCKED;
554 				/* Return from an user-initiated scan */
555 				wakeup(&ic->ic_scan_lock);
556 			} else if (ic->ic_scan_lock & IEEE80211_SCAN_REQUEST)
557 				goto wakeup;
558 			ic->ic_scan_count++;
559 		}
560 
561 		/*
562 		 * Reset the list of channels to scan and start again.
563 		 */
564 		ieee80211_next_scan(ifp);
565 		return;
566 	}
567 	selbs = NULL;
568 
569 	for (; ni != NULL; ni = nextbs) {
570 		nextbs = RB_NEXT(ieee80211_tree, &ic->ic_tree, ni);
571 		if (ni->ni_fails) {
572 			/*
573 			 * The configuration of the access points may change
574 			 * during my scan.  So delete the entry for the AP
575 			 * and retry to associate if there is another beacon.
576 			 */
577 			if (ni->ni_fails++ > 2)
578 				ieee80211_free_node(ic, ni);
579 			continue;
580 		}
581 		if (ieee80211_match_bss(ic, ni) == 0) {
582 			if (selbs == NULL)
583 				selbs = ni;
584 			else if (ni->ni_rssi > selbs->ni_rssi)
585 				selbs = ni;
586 		}
587 	}
588 	if (selbs == NULL)
589 		goto notfound;
590 	(*ic->ic_node_copy)(ic, ic->ic_bss, selbs);
591 	ni = ic->ic_bss;
592 
593 	/*
594 	 * Set the erp state (mostly the slot time) to deal with
595 	 * the auto-select case; this should be redundant if the
596 	 * mode is locked.
597 	 */
598 	ic->ic_curmode = ieee80211_chan2mode(ic, ni->ni_chan);
599 	ieee80211_reset_erp(ic);
600 
601 	if (ic->ic_flags & IEEE80211_F_RSNON)
602 		ieee80211_choose_rsnparams(ic);
603 	else if (ic->ic_flags & IEEE80211_F_WEPON)
604 		ni->ni_rsncipher = IEEE80211_CIPHER_USEGROUP;
605 
606 	ieee80211_node_newstate(selbs, IEEE80211_STA_BSS);
607 #ifndef IEEE80211_STA_ONLY
608 	if (ic->ic_opmode == IEEE80211_M_IBSS) {
609 		ieee80211_fix_rate(ic, ni, IEEE80211_F_DOFRATE |
610 		    IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
611 		if (ni->ni_rates.rs_nrates == 0)
612 			goto notfound;
613 		ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
614 	} else
615 #endif
616 		ieee80211_new_state(ic, IEEE80211_S_AUTH, -1);
617 
618  wakeup:
619 	if (ic->ic_scan_lock & IEEE80211_SCAN_REQUEST) {
620 		/* Return from an user-initiated scan */
621 		wakeup(&ic->ic_scan_lock);
622 	}
623 
624 	ic->ic_scan_lock = IEEE80211_SCAN_UNLOCKED;
625 }
626 
627 /*
628  * Autoselect the best RSN parameters (protocol, AKMP, pairwise cipher...)
629  * that are supported by both peers (STA mode only).
630  */
631 void
632 ieee80211_choose_rsnparams(struct ieee80211com *ic)
633 {
634 	struct ieee80211_node *ni = ic->ic_bss;
635 	struct ieee80211_pmk *pmk;
636 
637 	/* filter out unsupported protocol versions */
638 	ni->ni_rsnprotos &= ic->ic_rsnprotos;
639 	/* prefer RSN (aka WPA2) over WPA */
640 	if (ni->ni_rsnprotos & IEEE80211_PROTO_RSN)
641 		ni->ni_rsnprotos = IEEE80211_PROTO_RSN;
642 	else
643 		ni->ni_rsnprotos = IEEE80211_PROTO_WPA;
644 
645 	/* filter out unsupported AKMPs */
646 	ni->ni_rsnakms &= ic->ic_rsnakms;
647 	/* prefer SHA-256 based AKMPs */
648 	if ((ic->ic_flags & IEEE80211_F_PSK) && (ni->ni_rsnakms &
649 	    (IEEE80211_AKM_PSK | IEEE80211_AKM_SHA256_PSK))) {
650 		/* AP supports PSK AKMP and a PSK is configured */
651 		if (ni->ni_rsnakms & IEEE80211_AKM_SHA256_PSK)
652 			ni->ni_rsnakms = IEEE80211_AKM_SHA256_PSK;
653 		else
654 			ni->ni_rsnakms = IEEE80211_AKM_PSK;
655 	} else {
656 		if (ni->ni_rsnakms & IEEE80211_AKM_SHA256_8021X)
657 			ni->ni_rsnakms = IEEE80211_AKM_SHA256_8021X;
658 		else
659 			ni->ni_rsnakms = IEEE80211_AKM_8021X;
660 		/* check if we have a cached PMK for this AP */
661 		if (ni->ni_rsnprotos == IEEE80211_PROTO_RSN &&
662 		    (pmk = ieee80211_pmksa_find(ic, ni, NULL)) != NULL) {
663 			memcpy(ni->ni_pmkid, pmk->pmk_pmkid,
664 			    IEEE80211_PMKID_LEN);
665 			ni->ni_flags |= IEEE80211_NODE_PMKID;
666 		}
667 	}
668 
669 	/* filter out unsupported pairwise ciphers */
670 	ni->ni_rsnciphers &= ic->ic_rsnciphers;
671 	/* prefer CCMP over TKIP */
672 	if (ni->ni_rsnciphers & IEEE80211_CIPHER_CCMP)
673 		ni->ni_rsnciphers = IEEE80211_CIPHER_CCMP;
674 	else
675 		ni->ni_rsnciphers = IEEE80211_CIPHER_TKIP;
676 	ni->ni_rsncipher = ni->ni_rsnciphers;
677 
678 	/* use MFP if we both support it */
679 	if ((ic->ic_caps & IEEE80211_C_MFP) &&
680 	    (ni->ni_rsncaps & IEEE80211_RSNCAP_MFPC))
681 		ni->ni_flags |= IEEE80211_NODE_MFP;
682 }
683 
684 int
685 ieee80211_get_rate(struct ieee80211com *ic)
686 {
687 	u_int8_t (*rates)[IEEE80211_RATE_MAXSIZE];
688 	int rate;
689 
690 	rates = &ic->ic_bss->ni_rates.rs_rates;
691 
692 	if (ic->ic_fixed_rate != -1)
693 		rate = (*rates)[ic->ic_fixed_rate];
694 	else if (ic->ic_state == IEEE80211_S_RUN)
695 		rate = (*rates)[ic->ic_bss->ni_txrate];
696 	else
697 		rate = 0;
698 
699 	return rate & IEEE80211_RATE_VAL;
700 }
701 
702 struct ieee80211_node *
703 ieee80211_node_alloc(struct ieee80211com *ic)
704 {
705 	return malloc(sizeof(struct ieee80211_node), M_80211_NODE,
706 	    M_NOWAIT | M_ZERO);
707 }
708 
709 void
710 ieee80211_node_cleanup(struct ieee80211com *ic, struct ieee80211_node *ni)
711 {
712 	if (ni->ni_rsnie != NULL) {
713 		free(ni->ni_rsnie, M_DEVBUF);
714 		ni->ni_rsnie = NULL;
715 	}
716 }
717 
718 void
719 ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni)
720 {
721 	ieee80211_node_cleanup(ic, ni);
722 	free(ni, M_80211_NODE);
723 }
724 
725 void
726 ieee80211_node_copy(struct ieee80211com *ic,
727 	struct ieee80211_node *dst, const struct ieee80211_node *src)
728 {
729 	ieee80211_node_cleanup(ic, dst);
730 	*dst = *src;
731 	dst->ni_rsnie = NULL;
732 	if (src->ni_rsnie != NULL)
733 		ieee80211_save_ie(src->ni_rsnie, &dst->ni_rsnie);
734 }
735 
736 u_int8_t
737 ieee80211_node_getrssi(struct ieee80211com *ic,
738     const struct ieee80211_node *ni)
739 {
740 	return ni->ni_rssi;
741 }
742 
743 void
744 ieee80211_setup_node(struct ieee80211com *ic,
745 	struct ieee80211_node *ni, const u_int8_t *macaddr)
746 {
747 	int s;
748 
749 	DPRINTF(("%s\n", ether_sprintf((u_int8_t *)macaddr)));
750 	IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
751 	ieee80211_node_newstate(ni, IEEE80211_STA_CACHE);
752 
753 	ni->ni_ic = ic;	/* back-pointer */
754 
755 	/*
756 	 * Note we don't enable the inactive timer when acting
757 	 * as a station.  Nodes created in this mode represent
758 	 * AP's identified while scanning.  If we time them out
759 	 * then several things happen: we can't return the data
760 	 * to users to show the list of AP's we encountered, and
761 	 * more importantly, we'll incorrectly deauthenticate
762 	 * ourself because the inactivity timer will kick us off.
763 	 */
764 	s = splnet();
765 	if (ic->ic_opmode != IEEE80211_M_STA &&
766 	    RB_EMPTY(&ic->ic_tree))
767 		ic->ic_inact_timer = IEEE80211_INACT_WAIT;
768 	RB_INSERT(ieee80211_tree, &ic->ic_tree, ni);
769 	splx(s);
770 }
771 
772 struct ieee80211_node *
773 ieee80211_alloc_node(struct ieee80211com *ic, const u_int8_t *macaddr)
774 {
775 	struct ieee80211_node *ni = ieee80211_alloc_node_helper(ic);
776 	if (ni != NULL)
777 		ieee80211_setup_node(ic, ni, macaddr);
778 	else
779 		ic->ic_stats.is_rx_nodealloc++;
780 	return ni;
781 }
782 
783 struct ieee80211_node *
784 ieee80211_dup_bss(struct ieee80211com *ic, const u_int8_t *macaddr)
785 {
786 	struct ieee80211_node *ni = ieee80211_alloc_node_helper(ic);
787 	if (ni != NULL) {
788 		ieee80211_setup_node(ic, ni, macaddr);
789 		/*
790 		 * Inherit from ic_bss.
791 		 */
792 		IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid);
793 		ni->ni_chan = ic->ic_bss->ni_chan;
794 	} else
795 		ic->ic_stats.is_rx_nodealloc++;
796 	return ni;
797 }
798 
799 struct ieee80211_node *
800 ieee80211_find_node(struct ieee80211com *ic, const u_int8_t *macaddr)
801 {
802 	struct ieee80211_node ni;
803 
804 	IEEE80211_ADDR_COPY(ni.ni_macaddr, macaddr);
805 	return (RB_FIND(ieee80211_tree, &ic->ic_tree, &ni));
806 }
807 
808 /*
809  * Return a reference to the appropriate node for sending
810  * a data frame.  This handles node discovery in adhoc networks.
811  *
812  * Drivers will call this, so increase the reference count before
813  * returning the node.
814  */
815 struct ieee80211_node *
816 ieee80211_find_txnode(struct ieee80211com *ic, const u_int8_t *macaddr)
817 {
818 #ifndef IEEE80211_STA_ONLY
819 	struct ieee80211_node *ni;
820 	int s;
821 #endif
822 
823 	/*
824 	 * The destination address should be in the node table
825 	 * unless we are operating in station mode or this is a
826 	 * multicast/broadcast frame.
827 	 */
828 	if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr))
829 		return ieee80211_ref_node(ic->ic_bss);
830 
831 #ifndef IEEE80211_STA_ONLY
832 	s = splnet();
833 	ni = ieee80211_find_node(ic, macaddr);
834 	splx(s);
835 	if (ni == NULL) {
836 		if (ic->ic_opmode != IEEE80211_M_IBSS &&
837 		    ic->ic_opmode != IEEE80211_M_AHDEMO)
838 			return NULL;
839 
840 		/*
841 		 * Fake up a node; this handles node discovery in
842 		 * adhoc mode.  Note that for the driver's benefit
843 		 * we we treat this like an association so the driver
844 		 * has an opportunity to setup its private state.
845 		 *
846 		 * XXX need better way to handle this; issue probe
847 		 *     request so we can deduce rate set, etc.
848 		 */
849 		if ((ni = ieee80211_dup_bss(ic, macaddr)) == NULL)
850 			return NULL;
851 		/* XXX no rate negotiation; just dup */
852 		ni->ni_rates = ic->ic_bss->ni_rates;
853 		if (ic->ic_newassoc)
854 			(*ic->ic_newassoc)(ic, ni, 1);
855 	}
856 	return ieee80211_ref_node(ni);
857 #else
858 	return NULL;	/* can't get there */
859 #endif	/* IEEE80211_STA_ONLY */
860 }
861 
862 /*
863  * It is usually desirable to process a Rx packet using its sender's
864  * node-record instead of the BSS record.
865  *
866  * - AP mode: keep a node-record for every authenticated/associated
867  *   station *in the BSS*. For future use, we also track neighboring
868  *   APs, since they might belong to the same ESS.  APs in the same
869  *   ESS may bridge packets to each other, forming a Wireless
870  *   Distribution System (WDS).
871  *
872  * - IBSS mode: keep a node-record for every station *in the BSS*.
873  *   Also track neighboring stations by their beacons/probe responses.
874  *
875  * - monitor mode: keep a node-record for every sender, regardless
876  *   of BSS.
877  *
878  * - STA mode: the only available node-record is the BSS record,
879  *   ic->ic_bss.
880  *
881  * Of all the 802.11 Control packets, only the node-records for
882  * RTS packets node-record can be looked up.
883  *
884  * Return non-zero if the packet's node-record is kept, zero
885  * otherwise.
886  */
887 static __inline int
888 ieee80211_needs_rxnode(struct ieee80211com *ic,
889     const struct ieee80211_frame *wh, const u_int8_t **bssid)
890 {
891 	int monitor, rc = 0;
892 
893 	monitor = (ic->ic_opmode == IEEE80211_M_MONITOR);
894 
895 	*bssid = NULL;
896 
897 	switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) {
898 	case IEEE80211_FC0_TYPE_CTL:
899 		if (!monitor)
900 			break;
901 		return (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) ==
902 		    IEEE80211_FC0_SUBTYPE_RTS;
903 	case IEEE80211_FC0_TYPE_MGT:
904 		*bssid = wh->i_addr3;
905 		switch (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) {
906 		case IEEE80211_FC0_SUBTYPE_BEACON:
907 		case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
908 			rc = 1;
909 			break;
910 		default:
911 #ifndef IEEE80211_STA_ONLY
912 			if (ic->ic_opmode == IEEE80211_M_STA)
913 				break;
914 			rc = IEEE80211_ADDR_EQ(*bssid, ic->ic_bss->ni_bssid) ||
915 			     IEEE80211_ADDR_EQ(*bssid, etherbroadcastaddr);
916 #endif
917 			break;
918 		}
919 		break;
920 	case IEEE80211_FC0_TYPE_DATA:
921 		switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
922 		case IEEE80211_FC1_DIR_NODS:
923 			*bssid = wh->i_addr3;
924 #ifndef IEEE80211_STA_ONLY
925 			if (ic->ic_opmode == IEEE80211_M_IBSS ||
926 			    ic->ic_opmode == IEEE80211_M_AHDEMO)
927 				rc = IEEE80211_ADDR_EQ(*bssid,
928 				    ic->ic_bss->ni_bssid);
929 #endif
930 			break;
931 		case IEEE80211_FC1_DIR_TODS:
932 			*bssid = wh->i_addr1;
933 #ifndef IEEE80211_STA_ONLY
934 			if (ic->ic_opmode == IEEE80211_M_HOSTAP)
935 				rc = IEEE80211_ADDR_EQ(*bssid,
936 				    ic->ic_bss->ni_bssid);
937 #endif
938 			break;
939 		case IEEE80211_FC1_DIR_FROMDS:
940 		case IEEE80211_FC1_DIR_DSTODS:
941 			*bssid = wh->i_addr2;
942 #ifndef IEEE80211_STA_ONLY
943 			rc = (ic->ic_opmode == IEEE80211_M_HOSTAP);
944 #endif
945 			break;
946 		}
947 		break;
948 	}
949 	return monitor || rc;
950 }
951 
952 /*
953  * Drivers call this, so increase the reference count before returning
954  * the node.
955  */
956 struct ieee80211_node *
957 ieee80211_find_rxnode(struct ieee80211com *ic,
958     const struct ieee80211_frame *wh)
959 {
960 	static const u_int8_t zero[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
961 	struct ieee80211_node *ni;
962 	const u_int8_t *bssid;
963 	int s;
964 
965 	if (!ieee80211_needs_rxnode(ic, wh, &bssid))
966 		return ieee80211_ref_node(ic->ic_bss);
967 
968 	s = splnet();
969 	ni = ieee80211_find_node(ic, wh->i_addr2);
970 	splx(s);
971 
972 	if (ni != NULL)
973 		return ieee80211_ref_node(ni);
974 #ifndef IEEE80211_STA_ONLY
975 	if (ic->ic_opmode == IEEE80211_M_HOSTAP)
976 		return ieee80211_ref_node(ic->ic_bss);
977 #endif
978 	/* XXX see remarks in ieee80211_find_txnode */
979 	/* XXX no rate negotiation; just dup */
980 	if ((ni = ieee80211_dup_bss(ic, wh->i_addr2)) == NULL)
981 		return ieee80211_ref_node(ic->ic_bss);
982 
983 	IEEE80211_ADDR_COPY(ni->ni_bssid, (bssid != NULL) ? bssid : zero);
984 
985 	ni->ni_rates = ic->ic_bss->ni_rates;
986 	if (ic->ic_newassoc)
987 		(*ic->ic_newassoc)(ic, ni, 1);
988 
989 	DPRINTF(("faked-up node %p for %s\n", ni,
990 	    ether_sprintf((u_int8_t *)wh->i_addr2)));
991 
992 	return ieee80211_ref_node(ni);
993 }
994 
995 struct ieee80211_node *
996 ieee80211_find_node_for_beacon(struct ieee80211com *ic,
997     const u_int8_t *macaddr, const struct ieee80211_channel *chan,
998     const char *ssid, u_int8_t rssi)
999 {
1000 	struct ieee80211_node *ni, *keep = NULL;
1001 	int s, score = 0;
1002 
1003 	if ((ni = ieee80211_find_node(ic, macaddr)) != NULL) {
1004 		s = splnet();
1005 
1006 		if (ni->ni_chan != chan && ni->ni_rssi >= rssi)
1007 			score++;
1008 		if (ssid[1] == 0 && ni->ni_esslen != 0)
1009 			score++;
1010 		if (score > 0)
1011 			keep = ni;
1012 
1013 		splx(s);
1014 	}
1015 
1016 	return (keep);
1017 }
1018 
1019 void
1020 ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
1021 {
1022 	if (ni == ic->ic_bss)
1023 		panic("freeing bss node");
1024 
1025 	DPRINTF(("%s\n", ether_sprintf(ni->ni_macaddr)));
1026 	IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
1027 	RB_REMOVE(ieee80211_tree, &ic->ic_tree, ni);
1028 	ic->ic_nnodes--;
1029 	if (!IF_IS_EMPTY(&ni->ni_savedq)) {
1030 		IF_PURGE(&ni->ni_savedq);
1031 		if (ic->ic_set_tim != NULL)
1032 			(*ic->ic_set_tim)(ic, ni->ni_associd, 0);
1033 	}
1034 	if (RB_EMPTY(&ic->ic_tree))
1035 		ic->ic_inact_timer = 0;
1036 	(*ic->ic_node_free)(ic, ni);
1037 	/* TBD indicate to drivers that a new node can be allocated */
1038 }
1039 
1040 void
1041 ieee80211_release_node(struct ieee80211com *ic, struct ieee80211_node *ni)
1042 {
1043 	int s;
1044 
1045 	DPRINTF(("%s refcnt %d\n", ether_sprintf(ni->ni_macaddr),
1046 	    ni->ni_refcnt));
1047 	if (ieee80211_node_decref(ni) == 0 &&
1048 	    ni->ni_state == IEEE80211_STA_COLLECT) {
1049 		s = splnet();
1050 		ieee80211_free_node(ic, ni);
1051 		splx(s);
1052 	}
1053 }
1054 
1055 void
1056 ieee80211_free_allnodes(struct ieee80211com *ic)
1057 {
1058 	struct ieee80211_node *ni;
1059 	int s;
1060 
1061 	DPRINTF(("freeing all nodes\n"));
1062 	s = splnet();
1063 	while ((ni = RB_MIN(ieee80211_tree, &ic->ic_tree)) != NULL)
1064 		ieee80211_free_node(ic, ni);
1065 	splx(s);
1066 
1067 	if (ic->ic_bss != NULL)
1068 		ieee80211_node_cleanup(ic, ic->ic_bss);	/* for station mode */
1069 }
1070 
1071 /*
1072  * Timeout inactive nodes.
1073  */
1074 void
1075 ieee80211_clean_nodes(struct ieee80211com *ic)
1076 {
1077 	struct ieee80211_node *ni, *next_ni;
1078 	u_int gen = ic->ic_scangen++;		/* NB: ok 'cuz single-threaded*/
1079 	int s;
1080 
1081 	s = splnet();
1082 	for (ni = RB_MIN(ieee80211_tree, &ic->ic_tree);
1083 	    ni != NULL; ni = next_ni) {
1084 		next_ni = RB_NEXT(ieee80211_tree, &ic->ic_tree, ni);
1085 		if (ic->ic_nnodes <= ic->ic_max_nnodes)
1086 			break;
1087 		if (ni->ni_scangen == gen)	/* previously handled */
1088 			continue;
1089 		ni->ni_scangen = gen;
1090 		if (ni->ni_refcnt > 0)
1091 			continue;
1092 		DPRINTF(("station %s purged from LRU cache\n",
1093 		    ether_sprintf(ni->ni_macaddr)));
1094 		/*
1095 		 * Send a deauthenticate frame.
1096 		 */
1097 #ifndef IEEE80211_STA_ONLY
1098 		if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
1099 			splx(s);
1100 			IEEE80211_SEND_MGMT(ic, ni,
1101 			    IEEE80211_FC0_SUBTYPE_DEAUTH,
1102 			    IEEE80211_REASON_AUTH_EXPIRE);
1103 			s = splnet();
1104 			ieee80211_node_leave(ic, ni);
1105 		} else
1106 #endif
1107 			ieee80211_free_node(ic, ni);
1108 		ic->ic_stats.is_node_timeout++;
1109 	}
1110 	splx(s);
1111 }
1112 
1113 void
1114 ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f,
1115     void *arg)
1116 {
1117 	struct ieee80211_node *ni;
1118 	int s;
1119 
1120 	s = splnet();
1121 	RB_FOREACH(ni, ieee80211_tree, &ic->ic_tree)
1122 		(*f)(arg, ni);
1123 	splx(s);
1124 }
1125 
1126 /*
1127  * Install received rate set information in the node's state block.
1128  */
1129 int
1130 ieee80211_setup_rates(struct ieee80211com *ic, struct ieee80211_node *ni,
1131     const u_int8_t *rates, const u_int8_t *xrates, int flags)
1132 {
1133 	struct ieee80211_rateset *rs = &ni->ni_rates;
1134 
1135 	memset(rs, 0, sizeof(*rs));
1136 	rs->rs_nrates = rates[1];
1137 	memcpy(rs->rs_rates, rates + 2, rs->rs_nrates);
1138 	if (xrates != NULL) {
1139 		u_int8_t nxrates;
1140 		/*
1141 		 * Tack on 11g extended supported rate element.
1142 		 */
1143 		nxrates = xrates[1];
1144 		if (rs->rs_nrates + nxrates > IEEE80211_RATE_MAXSIZE) {
1145 			nxrates = IEEE80211_RATE_MAXSIZE - rs->rs_nrates;
1146 			DPRINTF(("extended rate set too large; "
1147 			    "only using %u of %u rates\n",
1148 			    nxrates, xrates[1]));
1149 			ic->ic_stats.is_rx_rstoobig++;
1150 		}
1151 		memcpy(rs->rs_rates + rs->rs_nrates, xrates+2, nxrates);
1152 		rs->rs_nrates += nxrates;
1153 	}
1154 	return ieee80211_fix_rate(ic, ni, flags);
1155 }
1156 
1157 #ifndef IEEE80211_STA_ONLY
1158 /*
1159  * Check if the specified node supports ERP.
1160  */
1161 int
1162 ieee80211_iserp_sta(const struct ieee80211_node *ni)
1163 {
1164 #define N(a)	(sizeof (a) / sizeof (a)[0])
1165 	static const u_int8_t rates[] = { 2, 4, 11, 22, 12, 24, 48 };
1166 	const struct ieee80211_rateset *rs = &ni->ni_rates;
1167 	int i, j;
1168 
1169 	/*
1170 	 * A STA supports ERP operation if it includes all the Clause 19
1171 	 * mandatory rates in its supported rate set.
1172 	 */
1173 	for (i = 0; i < N(rates); i++) {
1174 		for (j = 0; j < rs->rs_nrates; j++) {
1175 			if ((rs->rs_rates[j] & IEEE80211_RATE_VAL) == rates[i])
1176 				break;
1177 		}
1178 		if (j == rs->rs_nrates)
1179 			return 0;
1180 	}
1181 	return 1;
1182 #undef N
1183 }
1184 
1185 /*
1186  * This function is called to notify the 802.1X PACP machine that a new
1187  * 802.1X port is enabled and must be authenticated. For 802.11, a port
1188  * becomes enabled whenever a STA successfully completes Open System
1189  * authentication with an AP.
1190  */
1191 void
1192 ieee80211_needs_auth(struct ieee80211com *ic, struct ieee80211_node *ni)
1193 {
1194 	/*
1195 	 * XXX this could be done via the route socket of via a dedicated
1196 	 * EAP socket or another kernel->userland notification mechanism.
1197 	 * The notification should include the MAC address (ni_macaddr).
1198 	 */
1199 }
1200 
1201 /*
1202  * Handle a station joining an RSN network.
1203  */
1204 void
1205 ieee80211_node_join_rsn(struct ieee80211com *ic, struct ieee80211_node *ni)
1206 {
1207 	DPRINTF(("station %s associated using proto %d akm 0x%x "
1208 	    "cipher 0x%x groupcipher 0x%x\n", ether_sprintf(ni->ni_macaddr),
1209 	    ni->ni_rsnprotos, ni->ni_rsnakms, ni->ni_rsnciphers,
1210 	    ni->ni_rsngroupcipher));
1211 
1212 	ni->ni_rsn_state = RSNA_AUTHENTICATION;
1213 	ic->ic_rsnsta++;
1214 
1215 	ni->ni_key_count = 0;
1216 	ni->ni_port_valid = 0;
1217 	ni->ni_flags &= ~IEEE80211_NODE_TXRXPROT;
1218 	ni->ni_replaycnt = -1;	/* XXX */
1219 	ni->ni_rsn_retries = 0;
1220 	ni->ni_rsncipher = ni->ni_rsnciphers;
1221 	timeout_set(&ni->ni_rsn_timeout, ieee80211_eapol_timeout, ni);
1222 
1223 	ni->ni_rsn_state = RSNA_AUTHENTICATION_2;
1224 
1225 	/* generate a new authenticator nonce (ANonce) */
1226 	arc4random_buf(ni->ni_nonce, EAPOL_KEY_NONCE_LEN);
1227 
1228 	if (!ieee80211_is_8021x_akm(ni->ni_rsnakms)) {
1229 		memcpy(ni->ni_pmk, ic->ic_psk, IEEE80211_PMK_LEN);
1230 		ni->ni_flags |= IEEE80211_NODE_PMK;
1231 		(void)ieee80211_send_4way_msg1(ic, ni);
1232 	} else if (ni->ni_flags & IEEE80211_NODE_PMK) {
1233 		/* skip 802.1X auth if a cached PMK was found */
1234 		(void)ieee80211_send_4way_msg1(ic, ni);
1235 	} else {
1236 		/* no cached PMK found, needs full 802.1X auth */
1237 		ieee80211_needs_auth(ic, ni);
1238 	}
1239 }
1240 
1241 /*
1242  * Handle a station joining an 11g network.
1243  */
1244 void
1245 ieee80211_node_join_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
1246 {
1247 	if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME)) {
1248 		/*
1249 		 * Joining STA doesn't support short slot time.  We must
1250 		 * disable the use of short slot time for all other associated
1251 		 * STAs and give the driver a chance to reconfigure the
1252 		 * hardware.
1253 		 */
1254 		if (++ic->ic_longslotsta == 1) {
1255 			if (ic->ic_caps & IEEE80211_C_SHSLOT)
1256 				ieee80211_set_shortslottime(ic, 0);
1257 		}
1258 		DPRINTF(("[%s] station needs long slot time, count %d\n",
1259 		    ether_sprintf(ni->ni_macaddr), ic->ic_longslotsta));
1260 	}
1261 
1262 	if (!ieee80211_iserp_sta(ni)) {
1263 		/*
1264 		 * Joining STA is non-ERP.
1265 		 */
1266 		ic->ic_nonerpsta++;
1267 
1268 		DPRINTF(("[%s] station is non-ERP, %d non-ERP "
1269 		    "stations associated\n", ether_sprintf(ni->ni_macaddr),
1270 		    ic->ic_nonerpsta));
1271 
1272 		/* must enable the use of protection */
1273 		if (ic->ic_protmode != IEEE80211_PROT_NONE) {
1274 			DPRINTF(("enable use of protection\n"));
1275 			ic->ic_flags |= IEEE80211_F_USEPROT;
1276 		}
1277 
1278 		if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE))
1279 			ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE;
1280 	} else
1281 		ni->ni_flags |= IEEE80211_NODE_ERP;
1282 }
1283 
1284 void
1285 ieee80211_node_join(struct ieee80211com *ic, struct ieee80211_node *ni,
1286     int resp)
1287 {
1288 	int newassoc;
1289 
1290 	if (ni->ni_associd == 0) {
1291 		u_int16_t aid;
1292 
1293 		/*
1294 		 * It would be clever to search the bitmap
1295 		 * more efficiently, but this will do for now.
1296 		 */
1297 		for (aid = 1; aid < ic->ic_max_aid; aid++) {
1298 			if (!IEEE80211_AID_ISSET(aid,
1299 			    ic->ic_aid_bitmap))
1300 				break;
1301 		}
1302 		if (aid >= ic->ic_max_aid) {
1303 			IEEE80211_SEND_MGMT(ic, ni, resp,
1304 			    IEEE80211_REASON_ASSOC_TOOMANY);
1305 			ieee80211_node_leave(ic, ni);
1306 			return;
1307 		}
1308 		ni->ni_associd = aid | 0xc000;
1309 		IEEE80211_AID_SET(ni->ni_associd, ic->ic_aid_bitmap);
1310 		newassoc = 1;
1311 		if (ic->ic_curmode == IEEE80211_MODE_11G)
1312 			ieee80211_node_join_11g(ic, ni);
1313 	} else
1314 		newassoc = 0;
1315 
1316 	DPRINTF(("station %s %s associated at aid %d\n",
1317 	    ether_sprintf(ni->ni_macaddr), newassoc ? "newly" : "already",
1318 	    ni->ni_associd & ~0xc000));
1319 
1320 	/* give driver a chance to setup state like ni_txrate */
1321 	if (ic->ic_newassoc)
1322 		(*ic->ic_newassoc)(ic, ni, newassoc);
1323 	IEEE80211_SEND_MGMT(ic, ni, resp, IEEE80211_STATUS_SUCCESS);
1324 	ieee80211_node_newstate(ni, IEEE80211_STA_ASSOC);
1325 
1326 	if (!(ic->ic_flags & IEEE80211_F_RSNON)) {
1327 		ni->ni_port_valid = 1;
1328 		ni->ni_rsncipher = IEEE80211_CIPHER_USEGROUP;
1329 	} else
1330 		ieee80211_node_join_rsn(ic, ni);
1331 
1332 #if NBRIDGE > 0
1333 	/*
1334 	 * If the parent interface belongs to a bridge, learn
1335 	 * the node's address dynamically on this interface.
1336 	 */
1337 	if (ic->ic_if.if_bridge != NULL)
1338 		bridge_update(&ic->ic_if,
1339 		    (struct ether_addr *)ni->ni_macaddr, 0);
1340 #endif
1341 }
1342 
1343 /*
1344  * Handle a station leaving an RSN network.
1345  */
1346 void
1347 ieee80211_node_leave_rsn(struct ieee80211com *ic, struct ieee80211_node *ni)
1348 {
1349 	ni->ni_rsn_state = RSNA_DISCONNECTED;
1350 	ic->ic_rsnsta--;
1351 
1352 	ni->ni_rsn_state = RSNA_INITIALIZE;
1353 	if ((ni->ni_flags & IEEE80211_NODE_REKEY) &&
1354 	    --ic->ic_rsn_keydonesta == 0)
1355 		ieee80211_setkeysdone(ic);
1356 	ni->ni_flags &= ~IEEE80211_NODE_REKEY;
1357 
1358 	ni->ni_flags &= ~IEEE80211_NODE_PMK;
1359 	ni->ni_rsn_gstate = RSNA_IDLE;
1360 
1361 	timeout_del(&ni->ni_rsn_timeout);
1362 	ni->ni_rsn_retries = 0;
1363 	ni->ni_flags &= ~IEEE80211_NODE_TXRXPROT;
1364 	ni->ni_port_valid = 0;
1365 	(*ic->ic_delete_key)(ic, ni, &ni->ni_pairwise_key);
1366 }
1367 
1368 /*
1369  * Handle a station leaving an 11g network.
1370  */
1371 void
1372 ieee80211_node_leave_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
1373 {
1374 	if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME)) {
1375 #ifdef DIAGNOSTIC
1376 		if (ic->ic_longslotsta == 0) {
1377 			panic("bogus long slot station count %d",
1378 			    ic->ic_longslotsta);
1379 		}
1380 #endif
1381 		/* leaving STA did not support short slot time */
1382 		if (--ic->ic_longslotsta == 0) {
1383 			/*
1384 			 * All associated STAs now support short slot time, so
1385 			 * enable this feature and give the driver a chance to
1386 			 * reconfigure the hardware. Notice that IBSS always
1387 			 * use a long slot time.
1388 			 */
1389 			if ((ic->ic_caps & IEEE80211_C_SHSLOT) &&
1390 			    ic->ic_opmode != IEEE80211_M_IBSS)
1391 				ieee80211_set_shortslottime(ic, 1);
1392 		}
1393 		DPRINTF(("[%s] long slot time station leaves, count %d\n",
1394 		    ether_sprintf(ni->ni_macaddr), ic->ic_longslotsta));
1395 	}
1396 
1397 	if (!(ni->ni_flags & IEEE80211_NODE_ERP)) {
1398 #ifdef DIAGNOSTIC
1399 		if (ic->ic_nonerpsta == 0) {
1400 			panic("bogus non-ERP station count %d\n",
1401 			    ic->ic_nonerpsta);
1402 		}
1403 #endif
1404 		/* leaving STA was non-ERP */
1405 		if (--ic->ic_nonerpsta == 0) {
1406 			/*
1407 			 * All associated STAs are now ERP capable, disable use
1408 			 * of protection and re-enable short preamble support.
1409 			 */
1410 			ic->ic_flags &= ~IEEE80211_F_USEPROT;
1411 			if (ic->ic_caps & IEEE80211_C_SHPREAMBLE)
1412 				ic->ic_flags |= IEEE80211_F_SHPREAMBLE;
1413 		}
1414 		DPRINTF(("[%s] non-ERP station leaves, count %d\n",
1415 		    ether_sprintf(ni->ni_macaddr), ic->ic_nonerpsta));
1416 	}
1417 }
1418 
1419 /*
1420  * Handle bookkeeping for station deauthentication/disassociation
1421  * when operating as an ap.
1422  */
1423 void
1424 ieee80211_node_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
1425 {
1426 	if (ic->ic_opmode != IEEE80211_M_HOSTAP)
1427 		panic("not in ap mode, mode %u", ic->ic_opmode);
1428 	/*
1429 	 * If node wasn't previously associated all
1430 	 * we need to do is reclaim the reference.
1431 	 */
1432 	if (ni->ni_associd == 0)
1433 		return;
1434 	IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
1435 	ni->ni_associd = 0;
1436 
1437 	if (ni->ni_pwrsave == IEEE80211_PS_DOZE)
1438 		ic->ic_pssta--;
1439 
1440 	if (ic->ic_flags & IEEE80211_F_RSNON)
1441 		ieee80211_node_leave_rsn(ic, ni);
1442 
1443 	if (ic->ic_curmode == IEEE80211_MODE_11G)
1444 		ieee80211_node_leave_11g(ic, ni);
1445 
1446 	ieee80211_node_newstate(ni, IEEE80211_STA_COLLECT);
1447 
1448 #if NBRIDGE > 0
1449 	/*
1450 	 * If the parent interface belongs to a bridge, delete
1451 	 * any dynamically learned address for this node.
1452 	 */
1453 	if (ic->ic_if.if_bridge != NULL)
1454 		bridge_update(&ic->ic_if,
1455 		    (struct ether_addr *)ni->ni_macaddr, 1);
1456 #endif
1457 }
1458 
1459 static int
1460 ieee80211_do_slow_print(struct ieee80211com *ic, int *did_print)
1461 {
1462 	static const struct timeval merge_print_intvl = {
1463 		.tv_sec = 1, .tv_usec = 0
1464 	};
1465 	if ((ic->ic_if.if_flags & IFF_LINK0) == 0)
1466 		return 0;
1467 	if (!*did_print && (ic->ic_if.if_flags & IFF_DEBUG) == 0 &&
1468 	    !ratecheck(&ic->ic_last_merge_print, &merge_print_intvl))
1469 		return 0;
1470 
1471 	*did_print = 1;
1472 	return 1;
1473 }
1474 
1475 /* ieee80211_ibss_merge helps merge 802.11 ad hoc networks.  The
1476  * convention, set by the Wireless Ethernet Compatibility Alliance
1477  * (WECA), is that an 802.11 station will change its BSSID to match
1478  * the "oldest" 802.11 ad hoc network, on the same channel, that
1479  * has the station's desired SSID.  The "oldest" 802.11 network
1480  * sends beacons with the greatest TSF timestamp.
1481  *
1482  * Return ENETRESET if the BSSID changed, 0 otherwise.
1483  *
1484  * XXX Perhaps we should compensate for the time that elapses
1485  * between the MAC receiving the beacon and the host processing it
1486  * in ieee80211_ibss_merge.
1487  */
1488 int
1489 ieee80211_ibss_merge(struct ieee80211com *ic, struct ieee80211_node *ni,
1490     u_int64_t local_tsft)
1491 {
1492 	u_int64_t beacon_tsft;
1493 	int did_print = 0, sign;
1494 	union {
1495 		u_int64_t	word;
1496 		u_int8_t	tstamp[8];
1497 	} u;
1498 
1499 	/* ensure alignment */
1500 	(void)memcpy(&u, &ni->ni_tstamp[0], sizeof(u));
1501 	beacon_tsft = letoh64(u.word);
1502 
1503 	/* we are faster, let the other guy catch up */
1504 	if (beacon_tsft < local_tsft)
1505 		sign = -1;
1506 	else
1507 		sign = 1;
1508 
1509 	if (IEEE80211_ADDR_EQ(ni->ni_bssid, ic->ic_bss->ni_bssid)) {
1510 		if (!ieee80211_do_slow_print(ic, &did_print))
1511 			return 0;
1512 		printf("%s: tsft offset %s%llu\n", ic->ic_if.if_xname,
1513 		    (sign < 0) ? "-" : "",
1514 		    (sign < 0)
1515 			? (local_tsft - beacon_tsft)
1516 			: (beacon_tsft - local_tsft));
1517 		return 0;
1518 	}
1519 
1520 	if (sign < 0)
1521 		return 0;
1522 
1523 	if (ieee80211_match_bss(ic, ni) != 0)
1524 		return 0;
1525 
1526 	if (ieee80211_do_slow_print(ic, &did_print)) {
1527 		printf("%s: ieee80211_ibss_merge: bssid mismatch %s\n",
1528 		    ic->ic_if.if_xname, ether_sprintf(ni->ni_bssid));
1529 		printf("%s: my tsft %llu beacon tsft %llu\n",
1530 		    ic->ic_if.if_xname, local_tsft, beacon_tsft);
1531 		printf("%s: sync TSF with %s\n",
1532 		    ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr));
1533 	}
1534 
1535 	ic->ic_flags &= ~IEEE80211_F_SIBSS;
1536 
1537 	/* negotiate rates with new IBSS */
1538 	ieee80211_fix_rate(ic, ni, IEEE80211_F_DOFRATE |
1539 	    IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
1540 	if (ni->ni_rates.rs_nrates == 0) {
1541 		if (ieee80211_do_slow_print(ic, &did_print)) {
1542 			printf("%s: rates mismatch, BSSID %s\n",
1543 			    ic->ic_if.if_xname, ether_sprintf(ni->ni_bssid));
1544 		}
1545 		return 0;
1546 	}
1547 
1548 	if (ieee80211_do_slow_print(ic, &did_print)) {
1549 		printf("%s: sync BSSID %s -> ",
1550 		    ic->ic_if.if_xname, ether_sprintf(ic->ic_bss->ni_bssid));
1551 		printf("%s ", ether_sprintf(ni->ni_bssid));
1552 		printf("(from %s)\n", ether_sprintf(ni->ni_macaddr));
1553 	}
1554 
1555 	ieee80211_node_newstate(ni, IEEE80211_STA_BSS);
1556 	(*ic->ic_node_copy)(ic, ic->ic_bss, ni);
1557 
1558 	return ENETRESET;
1559 }
1560 
1561 void
1562 ieee80211_set_tim(struct ieee80211com *ic, int aid, int set)
1563 {
1564 	if (set)
1565 		setbit(ic->ic_tim_bitmap, aid & ~0xc000);
1566 	else
1567 		clrbit(ic->ic_tim_bitmap, aid & ~0xc000);
1568 }
1569 #endif	/* IEEE80211_STA_ONLY */
1570 
1571 /*
1572  * Compare nodes in the tree by lladdr
1573  */
1574 int
1575 ieee80211_node_cmp(const struct ieee80211_node *b1,
1576     const struct ieee80211_node *b2)
1577 {
1578 	return (memcmp(b1->ni_macaddr, b2->ni_macaddr, IEEE80211_ADDR_LEN));
1579 }
1580 
1581 /*
1582  * Generate red-black tree function logic
1583  */
1584 RB_GENERATE(ieee80211_tree, ieee80211_node, ni_node, ieee80211_node_cmp);
1585