xref: /haiku/src/libs/compat/freebsd_wlan/net80211/ieee80211_scan_sta.c (revision 9760dcae2038d47442f4658c2575844c6cf92c40)
1 /*-
2  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 /*
30  * IEEE 802.11 station scanning support.
31  */
32 #include "opt_wlan.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/kernel.h>
37 #include <sys/module.h>
38 
39 #include <sys/socket.h>
40 
41 #include <net/if.h>
42 #include <net/if_media.h>
43 #include <net/ethernet.h>
44 
45 #include <net80211/ieee80211_var.h>
46 #include <net80211/ieee80211_input.h>
47 #include <net80211/ieee80211_regdomain.h>
48 #ifdef IEEE80211_SUPPORT_TDMA
49 #include <net80211/ieee80211_tdma.h>
50 #endif
51 #ifdef IEEE80211_SUPPORT_MESH
52 #include <net80211/ieee80211_mesh.h>
53 #endif
54 
55 #include <net/bpf.h>
56 
57 /*
58  * Parameters for managing cache entries:
59  *
60  * o a station with STA_FAILS_MAX failures is not considered
61  *   when picking a candidate
62  * o a station that hasn't had an update in STA_PURGE_SCANS
63  *   (background) scans is discarded
64  * o after STA_FAILS_AGE seconds we clear the failure count
65  */
66 #define	STA_FAILS_MAX	2		/* assoc failures before ignored */
67 #define	STA_FAILS_AGE	(2*60)		/* time before clearing fails (secs) */
68 #define	STA_PURGE_SCANS	2		/* age for purging entries (scans) */
69 
70 /* XXX tunable */
71 #define	STA_RSSI_MIN	8		/* min acceptable rssi */
72 #define	STA_RSSI_MAX	40		/* max rssi for comparison */
73 
74 struct sta_entry {
75 	struct ieee80211_scan_entry base;
76 	TAILQ_ENTRY(sta_entry) se_list;
77 	LIST_ENTRY(sta_entry) se_hash;
78 	uint8_t		se_fails;		/* failure to associate count */
79 	uint8_t		se_seen;		/* seen during current scan */
80 	uint8_t		se_notseen;		/* not seen in previous scans */
81 	uint8_t		se_flags;
82 #define	STA_DEMOTE11B	0x01			/* match w/ demoted 11b chan */
83 	uint32_t	se_avgrssi;		/* LPF rssi state */
84 	unsigned long	se_lastupdate;		/* time of last update */
85 	unsigned long	se_lastfail;		/* time of last failure */
86 	unsigned long	se_lastassoc;		/* time of last association */
87 	u_int		se_scangen;		/* iterator scan gen# */
88 	u_int		se_countrygen;		/* gen# of last cc notify */
89 };
90 
91 #define	STA_HASHSIZE	32
92 /* simple hash is enough for variation of macaddr */
93 #define	STA_HASH(addr)	\
94 	(((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE)
95 
96 #define	MAX_IEEE_CHAN	256			/* max acceptable IEEE chan # */
97 CTASSERT(MAX_IEEE_CHAN >= 256);
98 
99 struct sta_table {
100 	struct mtx	st_lock;		/* on scan table */
101 	TAILQ_HEAD(, sta_entry) st_entry;	/* all entries */
102 	LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE];
103 	struct mtx	st_scanlock;		/* on st_scaniter */
104 	u_int		st_scaniter;		/* gen# for iterator */
105 	u_int		st_scangen;		/* scan generation # */
106 	int		st_newscan;
107 	/* ap-related state */
108 	int		st_maxrssi[MAX_IEEE_CHAN];
109 };
110 
111 static void sta_flush_table(struct sta_table *);
112 /*
113  * match_bss returns a bitmask describing if an entry is suitable
114  * for use.  If non-zero the entry was deemed not suitable and it's
115  * contents explains why.  The following flags are or'd to to this
116  * mask and can be used to figure out why the entry was rejected.
117  */
118 #define	MATCH_CHANNEL		0x00001	/* channel mismatch */
119 #define	MATCH_CAPINFO		0x00002	/* capabilities mismatch, e.g. no ess */
120 #define	MATCH_PRIVACY		0x00004	/* privacy mismatch */
121 #define	MATCH_RATE		0x00008	/* rate set mismatch */
122 #define	MATCH_SSID		0x00010	/* ssid mismatch */
123 #define	MATCH_BSSID		0x00020	/* bssid mismatch */
124 #define	MATCH_FAILS		0x00040	/* too many failed auth attempts */
125 #define	MATCH_NOTSEEN		0x00080	/* not seen in recent scans */
126 #define	MATCH_RSSI		0x00100	/* rssi deemed too low to use */
127 #define	MATCH_CC		0x00200	/* country code mismatch */
128 #define	MATCH_TDMA_NOIE		0x00400	/* no TDMA ie */
129 #define	MATCH_TDMA_NOTMASTER	0x00800	/* not TDMA master */
130 #define	MATCH_TDMA_NOSLOT	0x01000	/* all TDMA slots occupied */
131 #define	MATCH_TDMA_LOCAL	0x02000	/* local address */
132 #define	MATCH_TDMA_VERSION	0x04000	/* protocol version mismatch */
133 #define	MATCH_MESH_NOID		0x10000	/* no MESHID ie */
134 #define	MATCH_MESHID		0x20000	/* meshid mismatch */
135 static int match_bss(struct ieee80211vap *,
136 	const struct ieee80211_scan_state *, struct sta_entry *, int);
137 static void adhoc_age(struct ieee80211_scan_state *);
138 
139 static __inline int
140 isocmp(const uint8_t cc1[], const uint8_t cc2[])
141 {
142      return (cc1[0] == cc2[0] && cc1[1] == cc2[1]);
143 }
144 
145 /* number of references from net80211 layer */
146 static	int nrefs = 0;
147 /*
148  * Module glue.
149  */
150 IEEE80211_SCANNER_MODULE(sta, 1);
151 
152 /*
153  * Attach prior to any scanning work.
154  */
155 static int
156 sta_attach(struct ieee80211_scan_state *ss)
157 {
158 	struct sta_table *st;
159 
160 	st = (struct sta_table *) malloc(sizeof(struct sta_table),
161 		M_80211_SCAN, M_NOWAIT | M_ZERO);
162 	if (st == NULL)
163 		return 0;
164 	mtx_init(&st->st_lock, "scantable", "802.11 scan table", MTX_DEF);
165 	mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF);
166 	TAILQ_INIT(&st->st_entry);
167 	ss->ss_priv = st;
168 	nrefs++;			/* NB: we assume caller locking */
169 	return 1;
170 }
171 
172 /*
173  * Cleanup any private state.
174  */
175 static int
176 sta_detach(struct ieee80211_scan_state *ss)
177 {
178 	struct sta_table *st = ss->ss_priv;
179 
180 	if (st != NULL) {
181 		sta_flush_table(st);
182 		mtx_destroy(&st->st_lock);
183 		mtx_destroy(&st->st_scanlock);
184 		free(st, M_80211_SCAN);
185 		KASSERT(nrefs > 0, ("imbalanced attach/detach"));
186 		nrefs--;		/* NB: we assume caller locking */
187 	}
188 	return 1;
189 }
190 
191 /*
192  * Flush all per-scan state.
193  */
194 static int
195 sta_flush(struct ieee80211_scan_state *ss)
196 {
197 	struct sta_table *st = ss->ss_priv;
198 
199 	mtx_lock(&st->st_lock);
200 	sta_flush_table(st);
201 	mtx_unlock(&st->st_lock);
202 	ss->ss_last = 0;
203 	return 0;
204 }
205 
206 /*
207  * Flush all entries in the scan cache.
208  */
209 static void
210 sta_flush_table(struct sta_table *st)
211 {
212 	struct sta_entry *se, *next;
213 
214 	TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
215 		TAILQ_REMOVE(&st->st_entry, se, se_list);
216 		LIST_REMOVE(se, se_hash);
217 		ieee80211_ies_cleanup(&se->base.se_ies);
218 		free(se, M_80211_SCAN);
219 	}
220 	memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi));
221 }
222 
223 /*
224  * Process a beacon or probe response frame; create an
225  * entry in the scan cache or update any previous entry.
226  */
227 static int
228 sta_add(struct ieee80211_scan_state *ss,
229 	const struct ieee80211_scanparams *sp,
230 	const struct ieee80211_frame *wh,
231 	int subtype, int rssi, int noise)
232 {
233 #define	ISPROBE(_st)	((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
234 #define	PICK1ST(_ss) \
235 	((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \
236 	IEEE80211_SCAN_PICK1ST)
237 	struct sta_table *st = ss->ss_priv;
238 	const uint8_t *macaddr = wh->i_addr2;
239 	struct ieee80211vap *vap = ss->ss_vap;
240 	struct ieee80211com *ic = vap->iv_ic;
241 	struct sta_entry *se;
242 	struct ieee80211_scan_entry *ise;
243 	int hash;
244 
245 	hash = STA_HASH(macaddr);
246 
247 	mtx_lock(&st->st_lock);
248 	LIST_FOREACH(se, &st->st_hash[hash], se_hash)
249 		if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
250 			goto found;
251 	se = (struct sta_entry *) malloc(sizeof(struct sta_entry),
252 		M_80211_SCAN, M_NOWAIT | M_ZERO);
253 	if (se == NULL) {
254 		mtx_unlock(&st->st_lock);
255 		return 0;
256 	}
257 	se->se_scangen = st->st_scaniter-1;
258 	se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
259 	IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
260 	TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
261 	LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
262 found:
263 	ise = &se->base;
264 	/* XXX ap beaconing multiple ssid w/ same bssid */
265 	if (sp->ssid[1] != 0 &&
266 	    (ISPROBE(subtype) || ise->se_ssid[1] == 0))
267 		memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
268 	KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
269 		("rate set too large: %u", sp->rates[1]));
270 	memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
271 	if (sp->xrates != NULL) {
272 		/* XXX validate xrates[1] */
273 		KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
274 			("xrate set too large: %u", sp->xrates[1]));
275 		memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
276 	} else
277 		ise->se_xrates[1] = 0;
278 	IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
279 	if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
280 		/*
281 		 * Record rssi data using extended precision LPF filter.
282 		 *
283 		 * NB: use only on-channel data to insure we get a good
284 		 *     estimate of the signal we'll see when associated.
285 		 */
286 		IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
287 		ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
288 		ise->se_noise = noise;
289 	}
290 	memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
291 	ise->se_intval = sp->bintval;
292 	ise->se_capinfo = sp->capinfo;
293 #ifdef IEEE80211_SUPPORT_MESH
294 	if (sp->meshid != NULL && sp->meshid[1] != 0)
295 		memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]);
296 #endif
297 	/*
298 	 * Beware of overriding se_chan for frames seen
299 	 * off-channel; this can cause us to attempt an
300 	 * association on the wrong channel.
301 	 */
302 	if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
303 		struct ieee80211_channel *c;
304 		/*
305 		 * Off-channel, locate the home/bss channel for the sta
306 		 * using the value broadcast in the DSPARMS ie.  We know
307 		 * sp->chan has this value because it's used to calculate
308 		 * IEEE80211_BPARSE_OFFCHAN.
309 		 */
310 		c = ieee80211_find_channel_byieee(ic, sp->chan,
311 		    ic->ic_curchan->ic_flags);
312 		if (c != NULL) {
313 			ise->se_chan = c;
314 		} else if (ise->se_chan == NULL) {
315 			/* should not happen, pick something */
316 			ise->se_chan = ic->ic_curchan;
317 		}
318 	} else
319 		ise->se_chan = ic->ic_curchan;
320 	ise->se_fhdwell = sp->fhdwell;
321 	ise->se_fhindex = sp->fhindex;
322 	ise->se_erp = sp->erp;
323 	ise->se_timoff = sp->timoff;
324 	if (sp->tim != NULL) {
325 		const struct ieee80211_tim_ie *tim =
326 		    (const struct ieee80211_tim_ie *) sp->tim;
327 		ise->se_dtimperiod = tim->tim_period;
328 	}
329 	if (sp->country != NULL) {
330 		const struct ieee80211_country_ie *cie =
331 		    (const struct ieee80211_country_ie *) sp->country;
332 		/*
333 		 * If 11d is enabled and we're attempting to join a bss
334 		 * that advertises it's country code then compare our
335 		 * current settings to what we fetched from the country ie.
336 		 * If our country code is unspecified or different then
337 		 * dispatch an event to user space that identifies the
338 		 * country code so our regdomain config can be changed.
339 		 */
340 		/* XXX only for STA mode? */
341 		if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
342 		    (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
343 		    (ic->ic_regdomain.country == CTRY_DEFAULT ||
344 		     !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
345 			/* only issue one notify event per scan */
346 			if (se->se_countrygen != st->st_scangen) {
347 				ieee80211_notify_country(vap, ise->se_bssid,
348 				    cie->cc);
349 				se->se_countrygen = st->st_scangen;
350 			}
351 		}
352 		ise->se_cc[0] = cie->cc[0];
353 		ise->se_cc[1] = cie->cc[1];
354 	}
355 	/* NB: no need to setup ie ptrs; they are not (currently) used */
356 	(void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
357 
358 	/* clear failure count after STA_FAIL_AGE passes */
359 	if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
360 		se->se_fails = 0;
361 		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
362 		    "%s: fails %u", __func__, se->se_fails);
363 	}
364 
365 	se->se_lastupdate = ticks;		/* update time */
366 	se->se_seen = 1;
367 	se->se_notseen = 0;
368 
369 	KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
370 	if (rssi > st->st_maxrssi[sp->bchan])
371 		st->st_maxrssi[sp->bchan] = rssi;
372 
373 	mtx_unlock(&st->st_lock);
374 
375 	/*
376 	 * If looking for a quick choice and nothing's
377 	 * been found check here.
378 	 */
379 	if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
380 		ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
381 
382 	return 1;
383 #undef PICK1ST
384 #undef ISPROBE
385 }
386 
387 /*
388  * Check if a channel is excluded by user request.
389  */
390 static int
391 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
392 {
393 	return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
394 	    (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
395 	     c->ic_freq != vap->iv_des_chan->ic_freq));
396 }
397 
398 static struct ieee80211_channel *
399 find11gchannel(struct ieee80211com *ic, int i, int freq)
400 {
401 	struct ieee80211_channel *c;
402 	int j;
403 
404 	/*
405 	 * The normal ordering in the channel list is b channel
406 	 * immediately followed by g so optimize the search for
407 	 * this.  We'll still do a full search just in case.
408 	 */
409 	for (j = i+1; j < ic->ic_nchans; j++) {
410 		c = &ic->ic_channels[j];
411 		if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
412 			return c;
413 	}
414 	for (j = 0; j < i; j++) {
415 		c = &ic->ic_channels[j];
416 		if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
417 			return c;
418 	}
419 	return NULL;
420 }
421 
422 static const u_int chanflags[IEEE80211_MODE_MAX] = {
423 	[IEEE80211_MODE_AUTO]	  = IEEE80211_CHAN_B,
424 	[IEEE80211_MODE_11A]	  = IEEE80211_CHAN_A,
425 	[IEEE80211_MODE_11B]	  = IEEE80211_CHAN_B,
426 	[IEEE80211_MODE_11G]	  = IEEE80211_CHAN_G,
427 	[IEEE80211_MODE_FH]	  = IEEE80211_CHAN_FHSS,
428 	/* check base channel */
429 	[IEEE80211_MODE_TURBO_A]  = IEEE80211_CHAN_A,
430 	[IEEE80211_MODE_TURBO_G]  = IEEE80211_CHAN_G,
431 	[IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST,
432 	[IEEE80211_MODE_HALF]	  = IEEE80211_CHAN_HALF,
433 	[IEEE80211_MODE_QUARTER]  = IEEE80211_CHAN_QUARTER,
434 	/* check legacy */
435 	[IEEE80211_MODE_11NA]	  = IEEE80211_CHAN_A,
436 	[IEEE80211_MODE_11NG]	  = IEEE80211_CHAN_G,
437 };
438 
439 static void
440 add_channels(struct ieee80211vap *vap,
441 	struct ieee80211_scan_state *ss,
442 	enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
443 {
444 #define	N(a)	(sizeof(a) / sizeof(a[0]))
445 	struct ieee80211com *ic = vap->iv_ic;
446 	struct ieee80211_channel *c, *cg;
447 	u_int modeflags;
448 	int i;
449 
450 	KASSERT(mode < N(chanflags), ("Unexpected mode %u", mode));
451 	modeflags = chanflags[mode];
452 	for (i = 0; i < nfreq; i++) {
453 		if (ss->ss_last >= IEEE80211_SCAN_MAX)
454 			break;
455 
456 		c = ieee80211_find_channel(ic, freq[i], modeflags);
457 		if (c == NULL || isexcluded(vap, c))
458 			continue;
459 		if (mode == IEEE80211_MODE_AUTO) {
460 			/*
461 			 * XXX special-case 11b/g channels so we select
462 			 *     the g channel if both are present.
463 			 */
464 			if (IEEE80211_IS_CHAN_B(c) &&
465 			    (cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
466 				c = cg;
467 		}
468 		ss->ss_chans[ss->ss_last++] = c;
469 	}
470 #undef N
471 }
472 
473 struct scanlist {
474 	uint16_t	mode;
475 	uint16_t	count;
476 	const uint16_t	*list;
477 };
478 
479 static int
480 checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
481 {
482 	int i;
483 
484 	for (; scan->list != NULL; scan++) {
485 		for (i = 0; i < scan->count; i++)
486 			if (scan->list[i] == c->ic_freq)
487 				return 1;
488 	}
489 	return 0;
490 }
491 
492 static int
493 onscanlist(const struct ieee80211_scan_state *ss,
494 	const struct ieee80211_channel *c)
495 {
496 	int i;
497 
498 	for (i = 0; i < ss->ss_last; i++)
499 		if (ss->ss_chans[i] == c)
500 			return 1;
501 	return 0;
502 }
503 
504 static void
505 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
506 	const struct scanlist table[])
507 {
508 	struct ieee80211com *ic = vap->iv_ic;
509 	struct ieee80211_channel *c;
510 	int i;
511 
512 	for (i = 0; i < ic->ic_nchans; i++) {
513 		if (ss->ss_last >= IEEE80211_SCAN_MAX)
514 			break;
515 
516 		c = &ic->ic_channels[i];
517 		/*
518 		 * Ignore dynamic turbo channels; we scan them
519 		 * in normal mode (i.e. not boosted).  Likewise
520 		 * for HT channels, they get scanned using
521 		 * legacy rates.
522 		 */
523 		if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c))
524 			continue;
525 
526 		/*
527 		 * If a desired mode was specified, scan only
528 		 * channels that satisfy that constraint.
529 		 */
530 		if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
531 		    vap->iv_des_mode != ieee80211_chan2mode(c))
532 			continue;
533 
534 		/*
535 		 * Skip channels excluded by user request.
536 		 */
537 		if (isexcluded(vap, c))
538 			continue;
539 
540 		/*
541 		 * Add the channel unless it is listed in the
542 		 * fixed scan order tables.  This insures we
543 		 * don't sweep back in channels we filtered out
544 		 * above.
545 		 */
546 		if (checktable(table, c))
547 			continue;
548 
549 		/* Add channel to scanning list. */
550 		ss->ss_chans[ss->ss_last++] = c;
551 	}
552 	/*
553 	 * Explicitly add any desired channel if:
554 	 * - not already on the scan list
555 	 * - allowed by any desired mode constraint
556 	 * - there is space in the scan list
557 	 * This allows the channel to be used when the filtering
558 	 * mechanisms would otherwise elide it (e.g HT, turbo).
559 	 */
560 	c = vap->iv_des_chan;
561 	if (c != IEEE80211_CHAN_ANYC &&
562 	    !onscanlist(ss, c) &&
563 	    (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
564 	     vap->iv_des_mode == ieee80211_chan2mode(c)) &&
565 	    ss->ss_last < IEEE80211_SCAN_MAX)
566 		ss->ss_chans[ss->ss_last++] = c;
567 }
568 
569 static void
570 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
571 	const struct scanlist table[])
572 {
573 	const struct scanlist *scan;
574 	enum ieee80211_phymode mode;
575 
576 	ss->ss_last = 0;
577 	/*
578 	 * Use the table of ordered channels to construct the list
579 	 * of channels for scanning.  Any channels in the ordered
580 	 * list not in the master list will be discarded.
581 	 */
582 	for (scan = table; scan->list != NULL; scan++) {
583 		mode = scan->mode;
584 		if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
585 			/*
586 			 * If a desired mode was specified, scan only
587 			 * channels that satisfy that constraint.
588 			 */
589 			if (vap->iv_des_mode != mode) {
590 				/*
591 				 * The scan table marks 2.4Ghz channels as b
592 				 * so if the desired mode is 11g, then use
593 				 * the 11b channel list but upgrade the mode.
594 				 */
595 				if (vap->iv_des_mode != IEEE80211_MODE_11G ||
596 				    mode != IEEE80211_MODE_11B)
597 					continue;
598 				mode = IEEE80211_MODE_11G;	/* upgrade */
599 			}
600 		} else {
601 			/*
602 			 * This lets add_channels upgrade an 11b channel
603 			 * to 11g if available.
604 			 */
605 			if (mode == IEEE80211_MODE_11B)
606 				mode = IEEE80211_MODE_AUTO;
607 		}
608 #ifdef IEEE80211_F_XR
609 		/* XR does not operate on turbo channels */
610 		if ((vap->iv_flags & IEEE80211_F_XR) &&
611 		    (mode == IEEE80211_MODE_TURBO_A ||
612 		     mode == IEEE80211_MODE_TURBO_G ||
613 		     mode == IEEE80211_MODE_STURBO_A))
614 			continue;
615 #endif
616 		/*
617 		 * Add the list of the channels; any that are not
618 		 * in the master channel list will be discarded.
619 		 */
620 		add_channels(vap, ss, mode, scan->list, scan->count);
621 	}
622 
623 	/*
624 	 * Add the channels from the ic that are not present
625 	 * in the table.
626 	 */
627 	sweepchannels(ss, vap, table);
628 }
629 
630 static const uint16_t rcl1[] =		/* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
631 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
632 static const uint16_t rcl2[] =		/* 4 MKK channels: 34, 38, 42, 46 */
633 { 5170, 5190, 5210, 5230 };
634 static const uint16_t rcl3[] =		/* 2.4Ghz ch: 1,6,11,7,13 */
635 { 2412, 2437, 2462, 2442, 2472 };
636 static const uint16_t rcl4[] =		/* 5 FCC channel: 149, 153, 161, 165 */
637 { 5745, 5765, 5785, 5805, 5825 };
638 static const uint16_t rcl7[] =		/* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
639 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
640 static const uint16_t rcl8[] =		/* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
641 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
642 static const uint16_t rcl9[] =		/* 2.4Ghz ch: 14 */
643 { 2484 };
644 static const uint16_t rcl10[] =	/* Added Korean channels 2312-2372 */
645 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
646 static const uint16_t rcl11[] =	/* Added Japan channels in 4.9/5.0 spectrum */
647 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
648 #ifdef ATH_TURBO_SCAN
649 static const uint16_t rcl5[] =		/* 3 static turbo channels */
650 { 5210, 5250, 5290 };
651 static const uint16_t rcl6[] =		/* 2 static turbo channels */
652 { 5760, 5800 };
653 static const uint16_t rcl6x[] =	/* 4 FCC3 turbo channels */
654 { 5540, 5580, 5620, 5660 };
655 static const uint16_t rcl12[] =	/* 2.4Ghz Turbo channel 6 */
656 { 2437 };
657 static const uint16_t rcl13[] =	/* dynamic Turbo channels */
658 { 5200, 5240, 5280, 5765, 5805 };
659 #endif /* ATH_TURBO_SCAN */
660 
661 #define	X(a)	.count = sizeof(a)/sizeof(a[0]), .list = a
662 
663 static const struct scanlist staScanTable[] = {
664 	{ IEEE80211_MODE_11B,   	X(rcl3) },
665 	{ IEEE80211_MODE_11A,   	X(rcl1) },
666 	{ IEEE80211_MODE_11A,   	X(rcl2) },
667 	{ IEEE80211_MODE_11B,   	X(rcl8) },
668 	{ IEEE80211_MODE_11B,   	X(rcl9) },
669 	{ IEEE80211_MODE_11A,   	X(rcl4) },
670 #ifdef ATH_TURBO_SCAN
671 	{ IEEE80211_MODE_STURBO_A,	X(rcl5) },
672 	{ IEEE80211_MODE_STURBO_A,	X(rcl6) },
673 	{ IEEE80211_MODE_TURBO_A,	X(rcl6x) },
674 	{ IEEE80211_MODE_TURBO_A,	X(rcl13) },
675 #endif /* ATH_TURBO_SCAN */
676 	{ IEEE80211_MODE_11A,		X(rcl7) },
677 	{ IEEE80211_MODE_11B,		X(rcl10) },
678 	{ IEEE80211_MODE_11A,		X(rcl11) },
679 #ifdef ATH_TURBO_SCAN
680 	{ IEEE80211_MODE_TURBO_G,	X(rcl12) },
681 #endif /* ATH_TURBO_SCAN */
682 	{ .list = NULL }
683 };
684 
685 /*
686  * Start a station-mode scan by populating the channel list.
687  */
688 static int
689 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
690 {
691 	struct sta_table *st = ss->ss_priv;
692 
693 	makescanlist(ss, vap, staScanTable);
694 
695 	if (ss->ss_mindwell == 0)
696 		ss->ss_mindwell = msecs_to_ticks(20);	/* 20ms */
697 	if (ss->ss_maxdwell == 0)
698 		ss->ss_maxdwell = msecs_to_ticks(200);	/* 200ms */
699 
700 	st->st_scangen++;
701 	st->st_newscan = 1;
702 
703 	return 0;
704 }
705 
706 /*
707  * Restart a scan, typically a bg scan but can
708  * also be a fg scan that came up empty.
709  */
710 static int
711 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
712 {
713 	struct sta_table *st = ss->ss_priv;
714 
715 	st->st_newscan = 1;
716 	return 0;
717 }
718 
719 /*
720  * Cancel an ongoing scan.
721  */
722 static int
723 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
724 {
725 	return 0;
726 }
727 
728 /* unalligned little endian access */
729 #define LE_READ_2(p)					\
730 	((uint16_t)					\
731 	 ((((const uint8_t *)(p))[0]      ) |		\
732 	  (((const uint8_t *)(p))[1] <<  8)))
733 
734 /*
735  * Demote any supplied 11g channel to 11b.  There should
736  * always be an 11b channel but we check anyway...
737  */
738 static struct ieee80211_channel *
739 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
740 {
741 	struct ieee80211_channel *c;
742 
743 	if (IEEE80211_IS_CHAN_ANYG(chan) &&
744 	    vap->iv_des_mode == IEEE80211_MODE_AUTO) {
745 		c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
746 		    (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
747 		    IEEE80211_CHAN_B);
748 		if (c != NULL)
749 			chan = c;
750 	}
751 	return chan;
752 }
753 
754 static int
755 maxrate(const struct ieee80211_scan_entry *se)
756 {
757 	const struct ieee80211_ie_htcap *htcap =
758 	    (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
759 	int rmax, r, i;
760 	uint16_t caps;
761 
762 	rmax = 0;
763 	if (htcap != NULL) {
764 		/*
765 		 * HT station; inspect supported MCS and then adjust
766 		 * rate by channel width.  Could also include short GI
767 		 * in this if we want to be extra accurate.
768 		 */
769 		/* XXX assumes MCS15 is max */
770 		for (i = 15; i >= 0 && isclr(htcap->hc_mcsset, i); i--)
771 			;
772 		if (i >= 0) {
773 			caps = LE_READ_2(&htcap->hc_cap);
774 			/* XXX short/long GI */
775 			if (caps & IEEE80211_HTCAP_CHWIDTH40)
776 				rmax = ieee80211_htrates[i].ht40_rate_400ns;
777 			else
778 				rmax = ieee80211_htrates[i].ht40_rate_800ns;
779 		}
780 	}
781 	for (i = 0; i < se->se_rates[1]; i++) {
782 		r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
783 		if (r > rmax)
784 			rmax = r;
785 	}
786 	for (i = 0; i < se->se_xrates[1]; i++) {
787 		r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
788 		if (r > rmax)
789 			rmax = r;
790 	}
791 	return rmax;
792 }
793 
794 /*
795  * Compare the capabilities of two entries and decide which is
796  * more desirable (return >0 if a is considered better).  Note
797  * that we assume compatibility/usability has already been checked
798  * so we don't need to (e.g. validate whether privacy is supported).
799  * Used to select the best scan candidate for association in a BSS.
800  */
801 static int
802 sta_compare(const struct sta_entry *a, const struct sta_entry *b)
803 {
804 #define	PREFER(_a,_b,_what) do {			\
805 	if (((_a) ^ (_b)) & (_what))			\
806 		return ((_a) & (_what)) ? 1 : -1;	\
807 } while (0)
808 	int maxa, maxb;
809 	int8_t rssia, rssib;
810 	int weight;
811 
812 	/* privacy support */
813 	PREFER(a->base.se_capinfo, b->base.se_capinfo,
814 		IEEE80211_CAPINFO_PRIVACY);
815 
816 	/* compare count of previous failures */
817 	weight = b->se_fails - a->se_fails;
818 	if (abs(weight) > 1)
819 		return weight;
820 
821 	/*
822 	 * Compare rssi.  If the two are considered equivalent
823 	 * then fallback to other criteria.  We threshold the
824 	 * comparisons to avoid selecting an ap purely by rssi
825 	 * when both values may be good but one ap is otherwise
826 	 * more desirable (e.g. an 11b-only ap with stronger
827 	 * signal than an 11g ap).
828 	 */
829 	rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
830 	rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
831 	if (abs(rssib - rssia) < 5) {
832 		/* best/max rate preferred if signal level close enough XXX */
833 		maxa = maxrate(&a->base);
834 		maxb = maxrate(&b->base);
835 		if (maxa != maxb)
836 			return maxa - maxb;
837 		/* XXX use freq for channel preference */
838 		/* for now just prefer 5Ghz band to all other bands */
839 		PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
840 		       IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
841 	}
842 	/* all things being equal, use signal level */
843 	return a->base.se_rssi - b->base.se_rssi;
844 #undef PREFER
845 }
846 
847 /*
848  * Check rate set suitability and return the best supported rate.
849  * XXX inspect MCS for HT
850  */
851 static int
852 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
853     const struct ieee80211_scan_entry *se)
854 {
855 #define	RV(v)	((v) & IEEE80211_RATE_VAL)
856 	const struct ieee80211_rateset *srs;
857 	int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
858 	const uint8_t *rs;
859 
860 	okrate = badrate = 0;
861 
862 	srs = ieee80211_get_suprates(vap->iv_ic, chan);
863 	nrs = se->se_rates[1];
864 	rs = se->se_rates+2;
865 	/* XXX MCS */
866 	ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
867 	fixedrate = IEEE80211_FIXED_RATE_NONE;
868 again:
869 	for (i = 0; i < nrs; i++) {
870 		r = RV(rs[i]);
871 		badrate = r;
872 		/*
873 		 * Check any fixed rate is included.
874 		 */
875 		if (r == ucastrate)
876 			fixedrate = r;
877 		/*
878 		 * Check against our supported rates.
879 		 */
880 		for (j = 0; j < srs->rs_nrates; j++)
881 			if (r == RV(srs->rs_rates[j])) {
882 				if (r > okrate)		/* NB: track max */
883 					okrate = r;
884 				break;
885 			}
886 
887 		if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
888 			/*
889 			 * Don't try joining a BSS, if we don't support
890 			 * one of its basic rates.
891 			 */
892 			okrate = 0;
893 			goto back;
894 		}
895 	}
896 	if (rs == se->se_rates+2) {
897 		/* scan xrates too; sort of an algol68-style for loop */
898 		nrs = se->se_xrates[1];
899 		rs = se->se_xrates+2;
900 		goto again;
901 	}
902 
903 back:
904 	if (okrate == 0 || ucastrate != fixedrate)
905 		return badrate | IEEE80211_RATE_BASIC;
906 	else
907 		return RV(okrate);
908 #undef RV
909 }
910 
911 static __inline int
912 match_id(const uint8_t *ie, const uint8_t *val, int len)
913 {
914 	return (ie[1] == len && memcmp(ie+2, val, len) == 0);
915 }
916 
917 static int
918 match_ssid(const uint8_t *ie,
919 	int nssid, const struct ieee80211_scan_ssid ssids[])
920 {
921 	int i;
922 
923 	for (i = 0; i < nssid; i++) {
924 		if (match_id(ie, ssids[i].ssid, ssids[i].len))
925 			return 1;
926 	}
927 	return 0;
928 }
929 
930 #ifdef IEEE80211_SUPPORT_TDMA
931 static int
932 tdma_isfull(const struct ieee80211_tdma_param *tdma)
933 {
934 	int slot, slotcnt;
935 
936 	slotcnt = tdma->tdma_slotcnt;
937 	for (slot = slotcnt-1; slot >= 0; slot--)
938 		if (isclr(tdma->tdma_inuse, slot))
939 			return 0;
940 	return 1;
941 }
942 #endif /* IEEE80211_SUPPORT_TDMA */
943 
944 /*
945  * Test a scan candidate for suitability/compatibility.
946  */
947 static int
948 match_bss(struct ieee80211vap *vap,
949 	const struct ieee80211_scan_state *ss, struct sta_entry *se0,
950 	int debug)
951 {
952 	struct ieee80211com *ic = vap->iv_ic;
953 	struct ieee80211_scan_entry *se = &se0->base;
954         uint8_t rate;
955         int fail;
956 
957 	fail = 0;
958 	if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
959 		fail |= MATCH_CHANNEL;
960 	/*
961 	 * NB: normally the desired mode is used to construct
962 	 * the channel list, but it's possible for the scan
963 	 * cache to include entries for stations outside this
964 	 * list so we check the desired mode here to weed them
965 	 * out.
966 	 */
967 	if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
968 	    (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
969 	    chanflags[vap->iv_des_mode])
970 		fail |= MATCH_CHANNEL;
971 	if (vap->iv_opmode == IEEE80211_M_IBSS) {
972 		if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
973 			fail |= MATCH_CAPINFO;
974 #ifdef IEEE80211_SUPPORT_TDMA
975 	} else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
976 		/*
977 		 * Adhoc demo network setup shouldn't really be scanning
978 		 * but just in case skip stations operating in IBSS or
979 		 * BSS mode.
980 		 */
981 		if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
982 			fail |= MATCH_CAPINFO;
983 		/*
984 		 * TDMA operation cannot coexist with a normal 802.11 network;
985 		 * skip if IBSS or ESS capabilities are marked and require
986 		 * the beacon have a TDMA ie present.
987 		 */
988 		if (vap->iv_caps & IEEE80211_C_TDMA) {
989 			const struct ieee80211_tdma_param *tdma =
990 			    (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
991 			const struct ieee80211_tdma_state *ts = vap->iv_tdma;
992 
993 			if (tdma == NULL)
994 				fail |= MATCH_TDMA_NOIE;
995 			else if (tdma->tdma_version != ts->tdma_version)
996 				fail |= MATCH_TDMA_VERSION;
997 			else if (tdma->tdma_slot != 0)
998 				fail |= MATCH_TDMA_NOTMASTER;
999 			else if (tdma_isfull(tdma))
1000 				fail |= MATCH_TDMA_NOSLOT;
1001 #if 0
1002 			else if (ieee80211_local_address(se->se_macaddr))
1003 				fail |= MATCH_TDMA_LOCAL;
1004 #endif
1005 		}
1006 #endif /* IEEE80211_SUPPORT_TDMA */
1007 #ifdef IEEE80211_SUPPORT_MESH
1008 	} else if (vap->iv_opmode == IEEE80211_M_MBSS) {
1009 		const struct ieee80211_mesh_state *ms = vap->iv_mesh;
1010 		/*
1011 		 * Mesh nodes have IBSS & ESS bits in capinfo turned off
1012 		 * and two special ie's that must be present.
1013 		 */
1014 		if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1015 			fail |= MATCH_CAPINFO;
1016 		else if (se->se_meshid == NULL)
1017 			fail |= MATCH_MESH_NOID;
1018 		else if (ms->ms_idlen != 0 &&
1019 		    match_id(se->se_meshid, ms->ms_id, ms->ms_idlen))
1020 			fail |= MATCH_MESHID;
1021 #endif
1022 	} else {
1023 		if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
1024 			fail |= MATCH_CAPINFO;
1025 		/*
1026 		 * If 11d is enabled and we're attempting to join a bss
1027 		 * that advertises it's country code then compare our
1028 		 * current settings to what we fetched from the country ie.
1029 		 * If our country code is unspecified or different then do
1030 		 * not attempt to join the bss.  We should have already
1031 		 * dispatched an event to user space that identifies the
1032 		 * new country code so our regdomain config should match.
1033 		 */
1034 		if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
1035 		    (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
1036 		    se->se_cc[0] != 0 &&
1037 		    (ic->ic_regdomain.country == CTRY_DEFAULT ||
1038 		     !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
1039 			fail |= MATCH_CC;
1040 	}
1041 	if (vap->iv_flags & IEEE80211_F_PRIVACY) {
1042 		if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
1043 			fail |= MATCH_PRIVACY;
1044 	} else {
1045 		/* XXX does this mean privacy is supported or required? */
1046 		if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
1047 			fail |= MATCH_PRIVACY;
1048 	}
1049 	se0->se_flags &= ~STA_DEMOTE11B;
1050 	rate = check_rate(vap, se->se_chan, se);
1051 	if (rate & IEEE80211_RATE_BASIC) {
1052 		fail |= MATCH_RATE;
1053 		/*
1054 		 * An 11b-only ap will give a rate mismatch if there is an
1055 		 * OFDM fixed tx rate for 11g.  Try downgrading the channel
1056 		 * in the scan list to 11b and retry the rate check.
1057 		 */
1058 		if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
1059 			rate = check_rate(vap, demote11b(vap, se->se_chan), se);
1060 			if ((rate & IEEE80211_RATE_BASIC) == 0) {
1061 				fail &= ~MATCH_RATE;
1062 				se0->se_flags |= STA_DEMOTE11B;
1063 			}
1064 		}
1065 	} else if (rate < 2*24) {
1066 		/*
1067 		 * This is an 11b-only ap.  Check the desired mode in
1068 		 * case that needs to be honored (mode 11g filters out
1069 		 * 11b-only ap's).  Otherwise force any 11g channel used
1070 		 * in scanning to be demoted.
1071 		 *
1072 		 * NB: we cheat a bit here by looking at the max rate;
1073 		 *     we could/should check the rates.
1074 		 */
1075 		if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1076 		      vap->iv_des_mode == IEEE80211_MODE_11B))
1077 			fail |= MATCH_RATE;
1078 		else
1079 			se0->se_flags |= STA_DEMOTE11B;
1080 	}
1081 	if (ss->ss_nssid != 0 &&
1082 	    !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1083 		fail |= MATCH_SSID;
1084 	if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1085 	    !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1086 		fail |= MATCH_BSSID;
1087 	if (se0->se_fails >= STA_FAILS_MAX)
1088 		fail |= MATCH_FAILS;
1089 	if (se0->se_notseen >= STA_PURGE_SCANS)
1090 		fail |= MATCH_NOTSEEN;
1091 	if (se->se_rssi < STA_RSSI_MIN)
1092 		fail |= MATCH_RSSI;
1093 #ifdef IEEE80211_DEBUG
1094 	if (ieee80211_msg(vap, debug)) {
1095 		printf(" %c %s",
1096 		    fail & MATCH_FAILS ? '=' :
1097 		    fail & MATCH_NOTSEEN ? '^' :
1098 		    fail & MATCH_CC ? '$' :
1099 #ifdef IEEE80211_SUPPORT_TDMA
1100 		    fail & MATCH_TDMA_NOIE ? '&' :
1101 		    fail & MATCH_TDMA_VERSION ? 'v' :
1102 		    fail & MATCH_TDMA_NOTMASTER ? 's' :
1103 		    fail & MATCH_TDMA_NOSLOT ? 'f' :
1104 		    fail & MATCH_TDMA_LOCAL ? 'l' :
1105 #endif
1106 		    fail & MATCH_MESH_NOID ? 'm' :
1107 		    fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1108 		printf(" %s%c", ether_sprintf(se->se_bssid),
1109 		    fail & MATCH_BSSID ? '!' : ' ');
1110 		printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1111 			fail & MATCH_CHANNEL ? '!' : ' ');
1112 		printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1113 		printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1114 		    fail & MATCH_RATE ? '!' : ' ');
1115 		printf(" %4s%c",
1116 		    (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1117 		    (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "",
1118 		    fail & MATCH_CAPINFO ? '!' : ' ');
1119 		printf(" %3s%c ",
1120 		    (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1121 		    "wep" : "no",
1122 		    fail & MATCH_PRIVACY ? '!' : ' ');
1123 		ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1124 		printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : "");
1125 	}
1126 #endif
1127 	return fail;
1128 }
1129 
1130 static void
1131 sta_update_notseen(struct sta_table *st)
1132 {
1133 	struct sta_entry *se;
1134 
1135 	mtx_lock(&st->st_lock);
1136 	TAILQ_FOREACH(se, &st->st_entry, se_list) {
1137 		/*
1138 		 * If seen the reset and don't bump the count;
1139 		 * otherwise bump the ``not seen'' count.  Note
1140 		 * that this insures that stations for which we
1141 		 * see frames while not scanning but not during
1142 		 * this scan will not be penalized.
1143 		 */
1144 		if (se->se_seen)
1145 			se->se_seen = 0;
1146 		else
1147 			se->se_notseen++;
1148 	}
1149 	mtx_unlock(&st->st_lock);
1150 }
1151 
1152 static void
1153 sta_dec_fails(struct sta_table *st)
1154 {
1155 	struct sta_entry *se;
1156 
1157 	mtx_lock(&st->st_lock);
1158 	TAILQ_FOREACH(se, &st->st_entry, se_list)
1159 		if (se->se_fails)
1160 			se->se_fails--;
1161 	mtx_unlock(&st->st_lock);
1162 }
1163 
1164 static struct sta_entry *
1165 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1166 {
1167 	struct sta_table *st = ss->ss_priv;
1168 	struct sta_entry *se, *selbs = NULL;
1169 
1170 	IEEE80211_DPRINTF(vap, debug, " %s\n",
1171 	    "macaddr          bssid         chan  rssi  rate flag  wep  essid");
1172 	mtx_lock(&st->st_lock);
1173 	TAILQ_FOREACH(se, &st->st_entry, se_list) {
1174 		ieee80211_ies_expand(&se->base.se_ies);
1175 		if (match_bss(vap, ss, se, debug) == 0) {
1176 			if (selbs == NULL)
1177 				selbs = se;
1178 			else if (sta_compare(se, selbs) > 0)
1179 				selbs = se;
1180 		}
1181 	}
1182 	mtx_unlock(&st->st_lock);
1183 
1184 	return selbs;
1185 }
1186 
1187 /*
1188  * Pick an ap or ibss network to join or find a channel
1189  * to use to start an ibss network.
1190  */
1191 static int
1192 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1193 {
1194 	struct sta_table *st = ss->ss_priv;
1195 	struct sta_entry *selbs;
1196 	struct ieee80211_channel *chan;
1197 
1198 	KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1199 		("wrong mode %u", vap->iv_opmode));
1200 
1201 	if (st->st_newscan) {
1202 		sta_update_notseen(st);
1203 		st->st_newscan = 0;
1204 	}
1205 	if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1206 		/*
1207 		 * Manual/background scan, don't select+join the
1208 		 * bss, just return.  The scanning framework will
1209 		 * handle notification that this has completed.
1210 		 */
1211 		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1212 		return 1;
1213 	}
1214 	/*
1215 	 * Automatic sequencing; look for a candidate and
1216 	 * if found join the network.
1217 	 */
1218 	/* NB: unlocked read should be ok */
1219 	if (TAILQ_FIRST(&st->st_entry) == NULL) {
1220 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1221 			"%s: no scan candidate\n", __func__);
1222 		if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1223 			return 0;
1224 notfound:
1225 		/*
1226 		 * If nothing suitable was found decrement
1227 		 * the failure counts so entries will be
1228 		 * reconsidered the next time around.  We
1229 		 * really want to do this only for sta's
1230 		 * where we've previously had some success.
1231 		 */
1232 		sta_dec_fails(st);
1233 		st->st_newscan = 1;
1234 		return 0;			/* restart scan */
1235 	}
1236 	selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1237 	if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1238 		return (selbs != NULL);
1239 	if (selbs == NULL)
1240 		goto notfound;
1241 	chan = selbs->base.se_chan;
1242 	if (selbs->se_flags & STA_DEMOTE11B)
1243 		chan = demote11b(vap, chan);
1244 	if (!ieee80211_sta_join(vap, chan, &selbs->base))
1245 		goto notfound;
1246 	return 1;				/* terminate scan */
1247 }
1248 
1249 /*
1250  * Lookup an entry in the scan cache.  We assume we're
1251  * called from the bottom half or such that we don't need
1252  * to block the bottom half so that it's safe to return
1253  * a reference to an entry w/o holding the lock on the table.
1254  */
1255 static struct sta_entry *
1256 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1257 {
1258 	struct sta_entry *se;
1259 	int hash = STA_HASH(macaddr);
1260 
1261 	mtx_lock(&st->st_lock);
1262 	LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1263 		if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1264 			break;
1265 	mtx_unlock(&st->st_lock);
1266 
1267 	return se;		/* NB: unlocked */
1268 }
1269 
1270 static void
1271 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1272 {
1273 	struct ieee80211com *ic = vap->iv_ic;
1274 	struct ieee80211_node *ni = vap->iv_bss;
1275 	struct sta_table *st = ss->ss_priv;
1276 	enum ieee80211_phymode mode;
1277 	struct sta_entry *se, *selbs;
1278 	uint8_t roamRate, curRate, ucastRate;
1279 	int8_t roamRssi, curRssi;
1280 
1281 	se = sta_lookup(st, ni->ni_macaddr);
1282 	if (se == NULL) {
1283 		/* XXX something is wrong */
1284 		return;
1285 	}
1286 
1287 	mode = ieee80211_chan2mode(ic->ic_bsschan);
1288 	roamRate = vap->iv_roamparms[mode].rate;
1289 	roamRssi = vap->iv_roamparms[mode].rssi;
1290 	ucastRate = vap->iv_txparms[mode].ucastrate;
1291 	/* NB: the most up to date rssi is in the node, not the scan cache */
1292 	curRssi = ic->ic_node_getrssi(ni);
1293 	if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1294 		curRate = ni->ni_txrate;
1295 		roamRate &= IEEE80211_RATE_VAL;
1296 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1297 		    "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1298 		    __func__, curRssi, curRate, roamRssi, roamRate);
1299 	} else {
1300 		curRate = roamRate;	/* NB: insure compare below fails */
1301 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1302 		    "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1303 	}
1304 	/*
1305 	 * Check if a new ap should be used and switch.
1306 	 * XXX deauth current ap
1307 	 */
1308 	if (curRate < roamRate || curRssi < roamRssi) {
1309 		if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1310 			/*
1311 			 * Scan cache contents are too old; force a scan now
1312 			 * if possible so we have current state to make a
1313 			 * decision with.  We don't kick off a bg scan if
1314 			 * we're using dynamic turbo and boosted or if the
1315 			 * channel is busy.
1316 			 * XXX force immediate switch on scan complete
1317 			 */
1318 			if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1319 			    time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle))
1320 				ieee80211_bg_scan(vap, 0);
1321 			return;
1322 		}
1323 		se->base.se_rssi = curRssi;
1324 		selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1325 		if (selbs != NULL && selbs != se) {
1326 			struct ieee80211_channel *chan;
1327 
1328 			IEEE80211_DPRINTF(vap,
1329 			    IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1330 			    "%s: ROAM: curRate %u, roamRate %u, "
1331 			    "curRssi %d, roamRssi %d\n", __func__,
1332 			    curRate, roamRate, curRssi, roamRssi);
1333 
1334 			chan = selbs->base.se_chan;
1335 			if (selbs->se_flags & STA_DEMOTE11B)
1336 				chan = demote11b(vap, chan);
1337 			(void) ieee80211_sta_join(vap, chan, &selbs->base);
1338 		}
1339 	}
1340 }
1341 
1342 /*
1343  * Age entries in the scan cache.
1344  * XXX also do roaming since it's convenient
1345  */
1346 static void
1347 sta_age(struct ieee80211_scan_state *ss)
1348 {
1349 	struct ieee80211vap *vap = ss->ss_vap;
1350 
1351 	adhoc_age(ss);
1352 	/*
1353 	 * If rate control is enabled check periodically to see if
1354 	 * we should roam from our current connection to one that
1355 	 * might be better.  This only applies when we're operating
1356 	 * in sta mode and automatic roaming is set.
1357 	 * XXX defer if busy
1358 	 * XXX repeater station
1359 	 * XXX do when !bgscan?
1360 	 */
1361 	KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1362 		("wrong mode %u", vap->iv_opmode));
1363 	if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1364 	    (vap->iv_ic->ic_flags & IEEE80211_F_BGSCAN) &&
1365 	    vap->iv_state >= IEEE80211_S_RUN)
1366 		/* XXX vap is implicit */
1367 		sta_roam_check(ss, vap);
1368 }
1369 
1370 /*
1371  * Iterate over the entries in the scan cache, invoking
1372  * the callback function on each one.
1373  */
1374 static void
1375 sta_iterate(struct ieee80211_scan_state *ss,
1376 	ieee80211_scan_iter_func *f, void *arg)
1377 {
1378 	struct sta_table *st = ss->ss_priv;
1379 	struct sta_entry *se;
1380 	u_int gen;
1381 
1382 	mtx_lock(&st->st_scanlock);
1383 	gen = st->st_scaniter++;
1384 restart:
1385 	mtx_lock(&st->st_lock);
1386 	TAILQ_FOREACH(se, &st->st_entry, se_list) {
1387 		if (se->se_scangen != gen) {
1388 			se->se_scangen = gen;
1389 			/* update public state */
1390 			se->base.se_age = ticks - se->se_lastupdate;
1391 			mtx_unlock(&st->st_lock);
1392 			(*f)(arg, &se->base);
1393 			goto restart;
1394 		}
1395 	}
1396 	mtx_unlock(&st->st_lock);
1397 
1398 	mtx_unlock(&st->st_scanlock);
1399 }
1400 
1401 static void
1402 sta_assoc_fail(struct ieee80211_scan_state *ss,
1403 	const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1404 {
1405 	struct sta_table *st = ss->ss_priv;
1406 	struct sta_entry *se;
1407 
1408 	se = sta_lookup(st, macaddr);
1409 	if (se != NULL) {
1410 		se->se_fails++;
1411 		se->se_lastfail = ticks;
1412 		IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1413 		    macaddr, "%s: reason %u fails %u",
1414 		    __func__, reason, se->se_fails);
1415 	}
1416 }
1417 
1418 static void
1419 sta_assoc_success(struct ieee80211_scan_state *ss,
1420 	const uint8_t macaddr[IEEE80211_ADDR_LEN])
1421 {
1422 	struct sta_table *st = ss->ss_priv;
1423 	struct sta_entry *se;
1424 
1425 	se = sta_lookup(st, macaddr);
1426 	if (se != NULL) {
1427 #if 0
1428 		se->se_fails = 0;
1429 		IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1430 		    macaddr, "%s: fails %u",
1431 		    __func__, se->se_fails);
1432 #endif
1433 		se->se_lastassoc = ticks;
1434 	}
1435 }
1436 
1437 static const struct ieee80211_scanner sta_default = {
1438 	.scan_name		= "default",
1439 	.scan_attach		= sta_attach,
1440 	.scan_detach		= sta_detach,
1441 	.scan_start		= sta_start,
1442 	.scan_restart		= sta_restart,
1443 	.scan_cancel		= sta_cancel,
1444 	.scan_end		= sta_pick_bss,
1445 	.scan_flush		= sta_flush,
1446 	.scan_add		= sta_add,
1447 	.scan_age		= sta_age,
1448 	.scan_iterate		= sta_iterate,
1449 	.scan_assoc_fail	= sta_assoc_fail,
1450 	.scan_assoc_success	= sta_assoc_success,
1451 };
1452 
1453 /*
1454  * Adhoc mode-specific support.
1455  */
1456 
1457 static const uint16_t adhocWorld[] =		/* 36, 40, 44, 48 */
1458 { 5180, 5200, 5220, 5240 };
1459 static const uint16_t adhocFcc3[] =		/* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1460 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1461 static const uint16_t adhocMkk[] =		/* 34, 38, 42, 46 */
1462 { 5170, 5190, 5210, 5230 };
1463 static const uint16_t adhoc11b[] =		/* 10, 11 */
1464 { 2457, 2462 };
1465 
1466 static const struct scanlist adhocScanTable[] = {
1467 	{ IEEE80211_MODE_11B,   	X(adhoc11b) },
1468 	{ IEEE80211_MODE_11A,   	X(adhocWorld) },
1469 	{ IEEE80211_MODE_11A,   	X(adhocFcc3) },
1470 	{ IEEE80211_MODE_11B,   	X(adhocMkk) },
1471 	{ .list = NULL }
1472 };
1473 #undef X
1474 
1475 /*
1476  * Start an adhoc-mode scan by populating the channel list.
1477  */
1478 static int
1479 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1480 {
1481 	struct sta_table *st = ss->ss_priv;
1482 
1483 	makescanlist(ss, vap, adhocScanTable);
1484 
1485 	if (ss->ss_mindwell == 0)
1486 		ss->ss_mindwell = msecs_to_ticks(200);	/* 200ms */
1487 	if (ss->ss_maxdwell == 0)
1488 		ss->ss_maxdwell = msecs_to_ticks(200);	/* 200ms */
1489 
1490 	st->st_scangen++;
1491 	st->st_newscan = 1;
1492 
1493 	return 0;
1494 }
1495 
1496 /*
1497  * Select a channel to start an adhoc network on.
1498  * The channel list was populated with appropriate
1499  * channels so select one that looks least occupied.
1500  */
1501 static struct ieee80211_channel *
1502 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1503 {
1504 	struct sta_table *st = ss->ss_priv;
1505 	struct sta_entry *se;
1506 	struct ieee80211_channel *c, *bestchan;
1507 	int i, bestrssi, maxrssi;
1508 
1509 	bestchan = NULL;
1510 	bestrssi = -1;
1511 
1512 	mtx_lock(&st->st_lock);
1513 	for (i = 0; i < ss->ss_last; i++) {
1514 		c = ss->ss_chans[i];
1515 		/* never consider a channel with radar */
1516 		if (IEEE80211_IS_CHAN_RADAR(c))
1517 			continue;
1518 		/* skip channels disallowed by regulatory settings */
1519 		if (IEEE80211_IS_CHAN_NOADHOC(c))
1520 			continue;
1521 		/* check channel attributes for band compatibility */
1522 		if (flags != 0 && (c->ic_flags & flags) != flags)
1523 			continue;
1524 		maxrssi = 0;
1525 		TAILQ_FOREACH(se, &st->st_entry, se_list) {
1526 			if (se->base.se_chan != c)
1527 				continue;
1528 			if (se->base.se_rssi > maxrssi)
1529 				maxrssi = se->base.se_rssi;
1530 		}
1531 		if (bestchan == NULL || maxrssi < bestrssi)
1532 			bestchan = c;
1533 	}
1534 	mtx_unlock(&st->st_lock);
1535 
1536 	return bestchan;
1537 }
1538 
1539 /*
1540  * Pick an ibss network to join or find a channel
1541  * to use to start an ibss network.
1542  */
1543 static int
1544 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1545 {
1546 	struct sta_table *st = ss->ss_priv;
1547 	struct sta_entry *selbs;
1548 	struct ieee80211_channel *chan;
1549 
1550 	KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1551 		vap->iv_opmode == IEEE80211_M_AHDEMO ||
1552 		vap->iv_opmode == IEEE80211_M_MBSS,
1553 		("wrong opmode %u", vap->iv_opmode));
1554 
1555 	if (st->st_newscan) {
1556 		sta_update_notseen(st);
1557 		st->st_newscan = 0;
1558 	}
1559 	if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1560 		/*
1561 		 * Manual/background scan, don't select+join the
1562 		 * bss, just return.  The scanning framework will
1563 		 * handle notification that this has completed.
1564 		 */
1565 		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1566 		return 1;
1567 	}
1568 	/*
1569 	 * Automatic sequencing; look for a candidate and
1570 	 * if found join the network.
1571 	 */
1572 	/* NB: unlocked read should be ok */
1573 	if (TAILQ_FIRST(&st->st_entry) == NULL) {
1574 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1575 			"%s: no scan candidate\n", __func__);
1576 		if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1577 			return 0;
1578 notfound:
1579 		/* NB: never auto-start a tdma network for slot !0 */
1580 #ifdef IEEE80211_SUPPORT_TDMA
1581 		if (vap->iv_des_nssid &&
1582 		    ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1583 		     ieee80211_tdma_getslot(vap) == 0)) {
1584 #else
1585 		if (vap->iv_des_nssid) {
1586 #endif
1587 			/*
1588 			 * No existing adhoc network to join and we have
1589 			 * an ssid; start one up.  If no channel was
1590 			 * specified, try to select a channel.
1591 			 */
1592 			if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1593 			    IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1594 				struct ieee80211com *ic = vap->iv_ic;
1595 
1596 				chan = adhoc_pick_channel(ss, 0);
1597 				if (chan != NULL)
1598 					chan = ieee80211_ht_adjust_channel(ic,
1599 					    chan, vap->iv_flags_ht);
1600 			} else
1601 				chan = vap->iv_des_chan;
1602 			if (chan != NULL) {
1603 				ieee80211_create_ibss(vap, chan);
1604 				return 1;
1605 			}
1606 		}
1607 		/*
1608 		 * If nothing suitable was found decrement
1609 		 * the failure counts so entries will be
1610 		 * reconsidered the next time around.  We
1611 		 * really want to do this only for sta's
1612 		 * where we've previously had some success.
1613 		 */
1614 		sta_dec_fails(st);
1615 		st->st_newscan = 1;
1616 		return 0;			/* restart scan */
1617 	}
1618 	selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1619 	if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1620 		return (selbs != NULL);
1621 	if (selbs == NULL)
1622 		goto notfound;
1623 	chan = selbs->base.se_chan;
1624 	if (selbs->se_flags & STA_DEMOTE11B)
1625 		chan = demote11b(vap, chan);
1626 	if (!ieee80211_sta_join(vap, chan, &selbs->base))
1627 		goto notfound;
1628 	return 1;				/* terminate scan */
1629 }
1630 
1631 /*
1632  * Age entries in the scan cache.
1633  */
1634 static void
1635 adhoc_age(struct ieee80211_scan_state *ss)
1636 {
1637 	struct sta_table *st = ss->ss_priv;
1638 	struct sta_entry *se, *next;
1639 
1640 	mtx_lock(&st->st_lock);
1641 	TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1642 		if (se->se_notseen > STA_PURGE_SCANS) {
1643 			TAILQ_REMOVE(&st->st_entry, se, se_list);
1644 			LIST_REMOVE(se, se_hash);
1645 			ieee80211_ies_cleanup(&se->base.se_ies);
1646 			free(se, M_80211_SCAN);
1647 		}
1648 	}
1649 	mtx_unlock(&st->st_lock);
1650 }
1651 
1652 static const struct ieee80211_scanner adhoc_default = {
1653 	.scan_name		= "default",
1654 	.scan_attach		= sta_attach,
1655 	.scan_detach		= sta_detach,
1656 	.scan_start		= adhoc_start,
1657 	.scan_restart		= sta_restart,
1658 	.scan_cancel		= sta_cancel,
1659 	.scan_end		= adhoc_pick_bss,
1660 	.scan_flush		= sta_flush,
1661 	.scan_pickchan		= adhoc_pick_channel,
1662 	.scan_add		= sta_add,
1663 	.scan_age		= adhoc_age,
1664 	.scan_iterate		= sta_iterate,
1665 	.scan_assoc_fail	= sta_assoc_fail,
1666 	.scan_assoc_success	= sta_assoc_success,
1667 };
1668 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1669 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1670 
1671 static void
1672 ap_force_promisc(struct ieee80211com *ic)
1673 {
1674 	struct ifnet *ifp = ic->ic_ifp;
1675 
1676 	IEEE80211_LOCK(ic);
1677 	/* set interface into promiscuous mode */
1678 	ifp->if_flags |= IFF_PROMISC;
1679 	ieee80211_runtask(ic, &ic->ic_promisc_task);
1680 	IEEE80211_UNLOCK(ic);
1681 }
1682 
1683 static void
1684 ap_reset_promisc(struct ieee80211com *ic)
1685 {
1686 	IEEE80211_LOCK(ic);
1687 	ieee80211_syncifflag_locked(ic, IFF_PROMISC);
1688 	IEEE80211_UNLOCK(ic);
1689 }
1690 
1691 static int
1692 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1693 {
1694 	struct sta_table *st = ss->ss_priv;
1695 
1696 	makescanlist(ss, vap, staScanTable);
1697 
1698 	if (ss->ss_mindwell == 0)
1699 		ss->ss_mindwell = msecs_to_ticks(200);	/* 200ms */
1700 	if (ss->ss_maxdwell == 0)
1701 		ss->ss_maxdwell = msecs_to_ticks(200);	/* 200ms */
1702 
1703 	st->st_scangen++;
1704 	st->st_newscan = 1;
1705 
1706 	ap_force_promisc(vap->iv_ic);
1707 	return 0;
1708 }
1709 
1710 /*
1711  * Cancel an ongoing scan.
1712  */
1713 static int
1714 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1715 {
1716 	ap_reset_promisc(vap->iv_ic);
1717 	return 0;
1718 }
1719 
1720 /*
1721  * Pick a quiet channel to use for ap operation.
1722  */
1723 static struct ieee80211_channel *
1724 ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1725 {
1726 	struct sta_table *st = ss->ss_priv;
1727 	struct ieee80211_channel *bestchan = NULL;
1728 	int i;
1729 
1730 	/* XXX select channel more intelligently, e.g. channel spread, power */
1731 	/* NB: use scan list order to preserve channel preference */
1732 	for (i = 0; i < ss->ss_last; i++) {
1733 		struct ieee80211_channel *chan = ss->ss_chans[i];
1734 		/*
1735 		 * If the channel is unoccupied the max rssi
1736 		 * should be zero; just take it.  Otherwise
1737 		 * track the channel with the lowest rssi and
1738 		 * use that when all channels appear occupied.
1739 		 */
1740 		if (IEEE80211_IS_CHAN_RADAR(chan))
1741 			continue;
1742 		if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1743 			continue;
1744 		/* check channel attributes for band compatibility */
1745 		if (flags != 0 && (chan->ic_flags & flags) != flags)
1746 			continue;
1747 		KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1748 		/* XXX channel have interference */
1749 		if (st->st_maxrssi[chan->ic_ieee] == 0) {
1750 			/* XXX use other considerations */
1751 			return chan;
1752 		}
1753 		if (bestchan == NULL ||
1754 		    st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1755 			bestchan = chan;
1756 	}
1757 	return bestchan;
1758 }
1759 
1760 /*
1761  * Pick a quiet channel to use for ap operation.
1762  */
1763 static int
1764 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1765 {
1766 	struct ieee80211com *ic = vap->iv_ic;
1767 	struct ieee80211_channel *bestchan;
1768 
1769 	KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1770 		("wrong opmode %u", vap->iv_opmode));
1771 	bestchan = ap_pick_channel(ss, 0);
1772 	if (bestchan == NULL) {
1773 		/* no suitable channel, should not happen */
1774 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1775 		    "%s: no suitable channel! (should not happen)\n", __func__);
1776 		/* XXX print something? */
1777 		return 0;			/* restart scan */
1778 	}
1779 	/*
1780 	 * If this is a dynamic turbo channel, start with the unboosted one.
1781 	 */
1782 	if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1783 		bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1784 			bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1785 		if (bestchan == NULL) {
1786 			/* should never happen ?? */
1787 			return 0;
1788 		}
1789 	}
1790 	ap_reset_promisc(ic);
1791 	if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1792 		/*
1793 		 * Manual/background scan, don't select+join the
1794 		 * bss, just return.  The scanning framework will
1795 		 * handle notification that this has completed.
1796 		 */
1797 		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1798 		return 1;
1799 	}
1800 	ieee80211_create_ibss(vap,
1801 	    ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht));
1802 	return 1;
1803 }
1804 
1805 static const struct ieee80211_scanner ap_default = {
1806 	.scan_name		= "default",
1807 	.scan_attach		= sta_attach,
1808 	.scan_detach		= sta_detach,
1809 	.scan_start		= ap_start,
1810 	.scan_restart		= sta_restart,
1811 	.scan_cancel		= ap_cancel,
1812 	.scan_end		= ap_end,
1813 	.scan_flush		= sta_flush,
1814 	.scan_pickchan		= ap_pick_channel,
1815 	.scan_add		= sta_add,
1816 	.scan_age		= adhoc_age,
1817 	.scan_iterate		= sta_iterate,
1818 	.scan_assoc_success	= sta_assoc_success,
1819 	.scan_assoc_fail	= sta_assoc_fail,
1820 };
1821 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1822 
1823 #ifdef IEEE80211_SUPPORT_MESH
1824 /*
1825  * Pick an mbss network to join or find a channel
1826  * to use to start an mbss network.
1827  */
1828 static int
1829 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1830 {
1831 	struct sta_table *st = ss->ss_priv;
1832 	struct ieee80211_mesh_state *ms = vap->iv_mesh;
1833 	struct sta_entry *selbs;
1834 	struct ieee80211_channel *chan;
1835 
1836 	KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1837 		("wrong opmode %u", vap->iv_opmode));
1838 
1839 	if (st->st_newscan) {
1840 		sta_update_notseen(st);
1841 		st->st_newscan = 0;
1842 	}
1843 	if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1844 		/*
1845 		 * Manual/background scan, don't select+join the
1846 		 * bss, just return.  The scanning framework will
1847 		 * handle notification that this has completed.
1848 		 */
1849 		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1850 		return 1;
1851 	}
1852 	/*
1853 	 * Automatic sequencing; look for a candidate and
1854 	 * if found join the network.
1855 	 */
1856 	/* NB: unlocked read should be ok */
1857 	if (TAILQ_FIRST(&st->st_entry) == NULL) {
1858 		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1859 			"%s: no scan candidate\n", __func__);
1860 		if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1861 			return 0;
1862 notfound:
1863 		if (ms->ms_idlen != 0) {
1864 			/*
1865 			 * No existing mbss network to join and we have
1866 			 * a meshid; start one up.  If no channel was
1867 			 * specified, try to select a channel.
1868 			 */
1869 			if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1870 			    IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1871 				struct ieee80211com *ic = vap->iv_ic;
1872 
1873 				chan = adhoc_pick_channel(ss, 0);
1874 				if (chan != NULL)
1875 					chan = ieee80211_ht_adjust_channel(ic,
1876 					    chan, vap->iv_flags_ht);
1877 			} else
1878 				chan = vap->iv_des_chan;
1879 			if (chan != NULL) {
1880 				ieee80211_create_ibss(vap, chan);
1881 				return 1;
1882 			}
1883 		}
1884 		/*
1885 		 * If nothing suitable was found decrement
1886 		 * the failure counts so entries will be
1887 		 * reconsidered the next time around.  We
1888 		 * really want to do this only for sta's
1889 		 * where we've previously had some success.
1890 		 */
1891 		sta_dec_fails(st);
1892 		st->st_newscan = 1;
1893 		return 0;			/* restart scan */
1894 	}
1895 	selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1896 	if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1897 		return (selbs != NULL);
1898 	if (selbs == NULL)
1899 		goto notfound;
1900 	chan = selbs->base.se_chan;
1901 	if (selbs->se_flags & STA_DEMOTE11B)
1902 		chan = demote11b(vap, chan);
1903 	if (!ieee80211_sta_join(vap, chan, &selbs->base))
1904 		goto notfound;
1905 	return 1;				/* terminate scan */
1906 }
1907 
1908 static const struct ieee80211_scanner mesh_default = {
1909 	.scan_name		= "default",
1910 	.scan_attach		= sta_attach,
1911 	.scan_detach		= sta_detach,
1912 	.scan_start		= adhoc_start,
1913 	.scan_restart		= sta_restart,
1914 	.scan_cancel		= sta_cancel,
1915 	.scan_end		= mesh_pick_bss,
1916 	.scan_flush		= sta_flush,
1917 	.scan_pickchan		= adhoc_pick_channel,
1918 	.scan_add		= sta_add,
1919 	.scan_age		= adhoc_age,
1920 	.scan_iterate		= sta_iterate,
1921 	.scan_assoc_fail	= sta_assoc_fail,
1922 	.scan_assoc_success	= sta_assoc_success,
1923 };
1924 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
1925 #endif /* IEEE80211_SUPPORT_MESH */
1926 
1927 #if defined(__HAIKU__)
1928 void
1929 ieee80211_scan_sta_init()
1930 {
1931 	ieee80211_scanner_register(IEEE80211_M_STA, &sta_default);
1932 	ieee80211_scanner_register(IEEE80211_M_IBSS, &adhoc_default);
1933 }
1934 
1935 void
1936 ieee80211_scan_sta_uninit()
1937 {
1938 	ieee80211_scanner_unregister(IEEE80211_M_STA, &sta_default);
1939 	ieee80211_scanner_unregister(IEEE80211_M_IBSS, &adhoc_default);
1940 }
1941 #endif /* __HAIKU__ */
1942