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
74struct 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 # */
97CTASSERT(MAX_IEEE_CHAN >= 256);
98
99struct sta_table {
100	ieee80211_scan_table_lock_t 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
111static 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 */
135static int match_bss(struct ieee80211vap *,
136	const struct ieee80211_scan_state *, struct sta_entry *, int);
137static void adhoc_age(struct ieee80211_scan_state *);
138
139static __inline int
140isocmp(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 */
146static	int nrefs = 0;
147/*
148 * Module glue.
149 */
150IEEE80211_SCANNER_MODULE(sta, 1);
151
152/*
153 * Attach prior to any scanning work.
154 */
155static int
156sta_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	IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable");
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 */
175static int
176sta_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		IEEE80211_SCAN_TABLE_LOCK_DESTROY(st);
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 */
194static int
195sta_flush(struct ieee80211_scan_state *ss)
196{
197	struct sta_table *st = ss->ss_priv;
198
199	IEEE80211_SCAN_TABLE_LOCK(st);
200	sta_flush_table(st);
201	IEEE80211_SCAN_TABLE_UNLOCK(st);
202	ss->ss_last = 0;
203	return 0;
204}
205
206/*
207 * Flush all entries in the scan cache.
208 */
209static void
210sta_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 */
227static int
228sta_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 ieee80211_channel *c;
242	struct sta_entry *se;
243	struct ieee80211_scan_entry *ise;
244	int hash;
245
246	hash = STA_HASH(macaddr);
247
248	IEEE80211_SCAN_TABLE_LOCK(st);
249	LIST_FOREACH(se, &st->st_hash[hash], se_hash)
250		if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
251			goto found;
252	se = (struct sta_entry *) malloc(sizeof(struct sta_entry),
253		M_80211_SCAN, M_NOWAIT | M_ZERO);
254	if (se == NULL) {
255		IEEE80211_SCAN_TABLE_UNLOCK(st);
256		return 0;
257	}
258	se->se_scangen = st->st_scaniter-1;
259	se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER;
260	IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
261	TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
262	LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
263found:
264	ise = &se->base;
265	/* XXX ap beaconing multiple ssid w/ same bssid */
266	if (sp->ssid[1] != 0 &&
267	    (ISPROBE(subtype) || ise->se_ssid[1] == 0))
268		memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]);
269	KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE,
270		("rate set too large: %u", sp->rates[1]));
271	memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]);
272	if (sp->xrates != NULL) {
273		/* XXX validate xrates[1] */
274		KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE,
275			("xrate set too large: %u", sp->xrates[1]));
276		memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]);
277	} else
278		ise->se_xrates[1] = 0;
279	IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
280	if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) {
281		/*
282		 * Record rssi data using extended precision LPF filter.
283		 *
284		 * NB: use only on-channel data to insure we get a good
285		 *     estimate of the signal we'll see when associated.
286		 */
287		IEEE80211_RSSI_LPF(se->se_avgrssi, rssi);
288		ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi);
289		ise->se_noise = noise;
290	}
291	memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
292	ise->se_intval = sp->bintval;
293	ise->se_capinfo = sp->capinfo;
294#ifdef IEEE80211_SUPPORT_MESH
295	if (sp->meshid != NULL && sp->meshid[1] != 0)
296		memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]);
297#endif
298	/*
299	 * Beware of overriding se_chan for frames seen
300	 * off-channel; this can cause us to attempt an
301	 * association on the wrong channel.
302	 */
303	if (sp->status & IEEE80211_BPARSE_OFFCHAN) {
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	if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) {
321		/* Demote legacy networks to a non-HT channel. */
322		c = ieee80211_find_channel(ic, ise->se_chan->ic_freq,
323		    ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT);
324		KASSERT(c != NULL,
325		    ("no legacy channel %u", ise->se_chan->ic_ieee));
326		ise->se_chan = c;
327	}
328	ise->se_fhdwell = sp->fhdwell;
329	ise->se_fhindex = sp->fhindex;
330	ise->se_erp = sp->erp;
331	ise->se_timoff = sp->timoff;
332	if (sp->tim != NULL) {
333		const struct ieee80211_tim_ie *tim =
334		    (const struct ieee80211_tim_ie *) sp->tim;
335		ise->se_dtimperiod = tim->tim_period;
336	}
337	if (sp->country != NULL) {
338		const struct ieee80211_country_ie *cie =
339		    (const struct ieee80211_country_ie *) sp->country;
340		/*
341		 * If 11d is enabled and we're attempting to join a bss
342		 * that advertises it's country code then compare our
343		 * current settings to what we fetched from the country ie.
344		 * If our country code is unspecified or different then
345		 * dispatch an event to user space that identifies the
346		 * country code so our regdomain config can be changed.
347		 */
348		/* XXX only for STA mode? */
349		if ((IEEE80211_IS_CHAN_11D(ise->se_chan) ||
350		    (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
351		    (ic->ic_regdomain.country == CTRY_DEFAULT ||
352		     !isocmp(cie->cc, ic->ic_regdomain.isocc))) {
353			/* only issue one notify event per scan */
354			if (se->se_countrygen != st->st_scangen) {
355				ieee80211_notify_country(vap, ise->se_bssid,
356				    cie->cc);
357				se->se_countrygen = st->st_scangen;
358			}
359		}
360		ise->se_cc[0] = cie->cc[0];
361		ise->se_cc[1] = cie->cc[1];
362	}
363	/* NB: no need to setup ie ptrs; they are not (currently) used */
364	(void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len);
365
366	/* clear failure count after STA_FAIL_AGE passes */
367	if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) {
368		se->se_fails = 0;
369		IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
370		    "%s: fails %u", __func__, se->se_fails);
371	}
372
373	se->se_lastupdate = ticks;		/* update time */
374	se->se_seen = 1;
375	se->se_notseen = 0;
376
377	KASSERT(sizeof(sp->bchan) == 1, ("bchan size"));
378	if (rssi > st->st_maxrssi[sp->bchan])
379		st->st_maxrssi[sp->bchan] = rssi;
380
381	IEEE80211_SCAN_TABLE_UNLOCK(st);
382
383	/*
384	 * If looking for a quick choice and nothing's
385	 * been found check here.
386	 */
387	if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0)
388		ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
389
390	return 1;
391#undef PICK1ST
392#undef ISPROBE
393}
394
395/*
396 * Check if a channel is excluded by user request.
397 */
398static int
399isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c)
400{
401	return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) ||
402	    (vap->iv_des_chan != IEEE80211_CHAN_ANYC &&
403	     c->ic_freq != vap->iv_des_chan->ic_freq));
404}
405
406static struct ieee80211_channel *
407find11gchannel(struct ieee80211com *ic, int i, int freq)
408{
409	struct ieee80211_channel *c;
410	int j;
411
412	/*
413	 * The normal ordering in the channel list is b channel
414	 * immediately followed by g so optimize the search for
415	 * this.  We'll still do a full search just in case.
416	 */
417	for (j = i+1; j < ic->ic_nchans; j++) {
418		c = &ic->ic_channels[j];
419		if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
420			return c;
421	}
422	for (j = 0; j < i; j++) {
423		c = &ic->ic_channels[j];
424		if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c))
425			return c;
426	}
427	return NULL;
428}
429
430static const u_int chanflags[IEEE80211_MODE_MAX] = {
431	[IEEE80211_MODE_AUTO]	  = IEEE80211_CHAN_B,
432	[IEEE80211_MODE_11A]	  = IEEE80211_CHAN_A,
433	[IEEE80211_MODE_11B]	  = IEEE80211_CHAN_B,
434	[IEEE80211_MODE_11G]	  = IEEE80211_CHAN_G,
435	[IEEE80211_MODE_FH]	  = IEEE80211_CHAN_FHSS,
436	/* check base channel */
437	[IEEE80211_MODE_TURBO_A]  = IEEE80211_CHAN_A,
438	[IEEE80211_MODE_TURBO_G]  = IEEE80211_CHAN_G,
439	[IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST,
440	[IEEE80211_MODE_HALF]	  = IEEE80211_CHAN_HALF,
441	[IEEE80211_MODE_QUARTER]  = IEEE80211_CHAN_QUARTER,
442	/* check legacy */
443	[IEEE80211_MODE_11NA]	  = IEEE80211_CHAN_A,
444	[IEEE80211_MODE_11NG]	  = IEEE80211_CHAN_G,
445};
446
447static void
448add_channels(struct ieee80211vap *vap,
449	struct ieee80211_scan_state *ss,
450	enum ieee80211_phymode mode, const uint16_t freq[], int nfreq)
451{
452#define	N(a)	(sizeof(a) / sizeof(a[0]))
453	struct ieee80211com *ic = vap->iv_ic;
454	struct ieee80211_channel *c, *cg;
455	u_int modeflags;
456	int i;
457
458	KASSERT(mode < N(chanflags), ("Unexpected mode %u", mode));
459	modeflags = chanflags[mode];
460	for (i = 0; i < nfreq; i++) {
461		if (ss->ss_last >= IEEE80211_SCAN_MAX)
462			break;
463
464		c = ieee80211_find_channel(ic, freq[i], modeflags);
465		if (c == NULL || isexcluded(vap, c))
466			continue;
467		if (mode == IEEE80211_MODE_AUTO) {
468			/*
469			 * XXX special-case 11b/g channels so we select
470			 *     the g channel if both are present.
471			 */
472			if (IEEE80211_IS_CHAN_B(c) &&
473			    (cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
474				c = cg;
475		}
476		ss->ss_chans[ss->ss_last++] = c;
477	}
478#undef N
479}
480
481struct scanlist {
482	uint16_t	mode;
483	uint16_t	count;
484	const uint16_t	*list;
485};
486
487static int
488checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
489{
490	int i;
491
492	for (; scan->list != NULL; scan++) {
493		for (i = 0; i < scan->count; i++)
494			if (scan->list[i] == c->ic_freq)
495				return 1;
496	}
497	return 0;
498}
499
500static int
501onscanlist(const struct ieee80211_scan_state *ss,
502	const struct ieee80211_channel *c)
503{
504	int i;
505
506	for (i = 0; i < ss->ss_last; i++)
507		if (ss->ss_chans[i] == c)
508			return 1;
509	return 0;
510}
511
512static void
513sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
514	const struct scanlist table[])
515{
516	struct ieee80211com *ic = vap->iv_ic;
517	struct ieee80211_channel *c;
518	int i;
519
520	for (i = 0; i < ic->ic_nchans; i++) {
521		if (ss->ss_last >= IEEE80211_SCAN_MAX)
522			break;
523
524		c = &ic->ic_channels[i];
525		/*
526		 * Ignore dynamic turbo channels; we scan them
527		 * in normal mode (i.e. not boosted).  Likewise
528		 * for HT channels, they get scanned using
529		 * legacy rates.
530		 */
531		if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c))
532			continue;
533
534		/*
535		 * If a desired mode was specified, scan only
536		 * channels that satisfy that constraint.
537		 */
538		if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
539		    vap->iv_des_mode != ieee80211_chan2mode(c))
540			continue;
541
542		/*
543		 * Skip channels excluded by user request.
544		 */
545		if (isexcluded(vap, c))
546			continue;
547
548		/*
549		 * Add the channel unless it is listed in the
550		 * fixed scan order tables.  This insures we
551		 * don't sweep back in channels we filtered out
552		 * above.
553		 */
554		if (checktable(table, c))
555			continue;
556
557		/* Add channel to scanning list. */
558		ss->ss_chans[ss->ss_last++] = c;
559	}
560	/*
561	 * Explicitly add any desired channel if:
562	 * - not already on the scan list
563	 * - allowed by any desired mode constraint
564	 * - there is space in the scan list
565	 * This allows the channel to be used when the filtering
566	 * mechanisms would otherwise elide it (e.g HT, turbo).
567	 */
568	c = vap->iv_des_chan;
569	if (c != IEEE80211_CHAN_ANYC &&
570	    !onscanlist(ss, c) &&
571	    (vap->iv_des_mode == IEEE80211_MODE_AUTO ||
572	     vap->iv_des_mode == ieee80211_chan2mode(c)) &&
573	    ss->ss_last < IEEE80211_SCAN_MAX)
574		ss->ss_chans[ss->ss_last++] = c;
575}
576
577static void
578makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
579	const struct scanlist table[])
580{
581	const struct scanlist *scan;
582	enum ieee80211_phymode mode;
583
584	ss->ss_last = 0;
585	/*
586	 * Use the table of ordered channels to construct the list
587	 * of channels for scanning.  Any channels in the ordered
588	 * list not in the master list will be discarded.
589	 */
590	for (scan = table; scan->list != NULL; scan++) {
591		mode = scan->mode;
592		if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
593			/*
594			 * If a desired mode was specified, scan only
595			 * channels that satisfy that constraint.
596			 */
597			if (vap->iv_des_mode != mode) {
598				/*
599				 * The scan table marks 2.4Ghz channels as b
600				 * so if the desired mode is 11g, then use
601				 * the 11b channel list but upgrade the mode.
602				 */
603				if (vap->iv_des_mode != IEEE80211_MODE_11G ||
604				    mode != IEEE80211_MODE_11B)
605					continue;
606				mode = IEEE80211_MODE_11G;	/* upgrade */
607			}
608		} else {
609			/*
610			 * This lets add_channels upgrade an 11b channel
611			 * to 11g if available.
612			 */
613			if (mode == IEEE80211_MODE_11B)
614				mode = IEEE80211_MODE_AUTO;
615		}
616#ifdef IEEE80211_F_XR
617		/* XR does not operate on turbo channels */
618		if ((vap->iv_flags & IEEE80211_F_XR) &&
619		    (mode == IEEE80211_MODE_TURBO_A ||
620		     mode == IEEE80211_MODE_TURBO_G ||
621		     mode == IEEE80211_MODE_STURBO_A))
622			continue;
623#endif
624		/*
625		 * Add the list of the channels; any that are not
626		 * in the master channel list will be discarded.
627		 */
628		add_channels(vap, ss, mode, scan->list, scan->count);
629	}
630
631	/*
632	 * Add the channels from the ic that are not present
633	 * in the table.
634	 */
635	sweepchannels(ss, vap, table);
636}
637
638static const uint16_t rcl1[] =		/* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
639{ 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
640static const uint16_t rcl2[] =		/* 4 MKK channels: 34, 38, 42, 46 */
641{ 5170, 5190, 5210, 5230 };
642static const uint16_t rcl3[] =		/* 2.4Ghz ch: 1,6,11,7,13 */
643{ 2412, 2437, 2462, 2442, 2472 };
644static const uint16_t rcl4[] =		/* 5 FCC channel: 149, 153, 161, 165 */
645{ 5745, 5765, 5785, 5805, 5825 };
646static const uint16_t rcl7[] =		/* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
647{ 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
648static const uint16_t rcl8[] =		/* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
649{ 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
650static const uint16_t rcl9[] =		/* 2.4Ghz ch: 14 */
651{ 2484 };
652static const uint16_t rcl10[] =	/* Added Korean channels 2312-2372 */
653{ 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
654static const uint16_t rcl11[] =	/* Added Japan channels in 4.9/5.0 spectrum */
655{ 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
656#ifdef ATH_TURBO_SCAN
657static const uint16_t rcl5[] =		/* 3 static turbo channels */
658{ 5210, 5250, 5290 };
659static const uint16_t rcl6[] =		/* 2 static turbo channels */
660{ 5760, 5800 };
661static const uint16_t rcl6x[] =	/* 4 FCC3 turbo channels */
662{ 5540, 5580, 5620, 5660 };
663static const uint16_t rcl12[] =	/* 2.4Ghz Turbo channel 6 */
664{ 2437 };
665static const uint16_t rcl13[] =	/* dynamic Turbo channels */
666{ 5200, 5240, 5280, 5765, 5805 };
667#endif /* ATH_TURBO_SCAN */
668
669#define	X(a)	.count = sizeof(a)/sizeof(a[0]), .list = a
670
671static const struct scanlist staScanTable[] = {
672	{ IEEE80211_MODE_11B,   	X(rcl3) },
673	{ IEEE80211_MODE_11A,   	X(rcl1) },
674	{ IEEE80211_MODE_11A,   	X(rcl2) },
675	{ IEEE80211_MODE_11B,   	X(rcl8) },
676	{ IEEE80211_MODE_11B,   	X(rcl9) },
677	{ IEEE80211_MODE_11A,   	X(rcl4) },
678#ifdef ATH_TURBO_SCAN
679	{ IEEE80211_MODE_STURBO_A,	X(rcl5) },
680	{ IEEE80211_MODE_STURBO_A,	X(rcl6) },
681	{ IEEE80211_MODE_TURBO_A,	X(rcl6x) },
682	{ IEEE80211_MODE_TURBO_A,	X(rcl13) },
683#endif /* ATH_TURBO_SCAN */
684	{ IEEE80211_MODE_11A,		X(rcl7) },
685	{ IEEE80211_MODE_11B,		X(rcl10) },
686	{ IEEE80211_MODE_11A,		X(rcl11) },
687#ifdef ATH_TURBO_SCAN
688	{ IEEE80211_MODE_TURBO_G,	X(rcl12) },
689#endif /* ATH_TURBO_SCAN */
690	{ .list = NULL }
691};
692
693/*
694 * Start a station-mode scan by populating the channel list.
695 */
696static int
697sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
698{
699	struct sta_table *st = ss->ss_priv;
700
701	makescanlist(ss, vap, staScanTable);
702
703	if (ss->ss_mindwell == 0)
704		ss->ss_mindwell = msecs_to_ticks(20);	/* 20ms */
705	if (ss->ss_maxdwell == 0)
706		ss->ss_maxdwell = msecs_to_ticks(200);	/* 200ms */
707
708	st->st_scangen++;
709	st->st_newscan = 1;
710
711	return 0;
712}
713
714/*
715 * Restart a scan, typically a bg scan but can
716 * also be a fg scan that came up empty.
717 */
718static int
719sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
720{
721	struct sta_table *st = ss->ss_priv;
722
723	st->st_newscan = 1;
724	return 0;
725}
726
727/*
728 * Cancel an ongoing scan.
729 */
730static int
731sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
732{
733	return 0;
734}
735
736/* unalligned little endian access */
737#define LE_READ_2(p)					\
738	((uint16_t)					\
739	 ((((const uint8_t *)(p))[0]      ) |		\
740	  (((const uint8_t *)(p))[1] <<  8)))
741
742/*
743 * Demote any supplied 11g channel to 11b.  There should
744 * always be an 11b channel but we check anyway...
745 */
746static struct ieee80211_channel *
747demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan)
748{
749	struct ieee80211_channel *c;
750
751	if (IEEE80211_IS_CHAN_ANYG(chan) &&
752	    vap->iv_des_mode == IEEE80211_MODE_AUTO) {
753		c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq,
754		    (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) |
755		    IEEE80211_CHAN_B);
756		if (c != NULL)
757			chan = c;
758	}
759	return chan;
760}
761
762static int
763maxrate(const struct ieee80211_scan_entry *se)
764{
765	const struct ieee80211_ie_htcap *htcap =
766	    (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie;
767	int rmax, r, i, txstream;
768	uint16_t caps;
769	uint8_t txparams;
770
771	rmax = 0;
772	if (htcap != NULL) {
773		/*
774		 * HT station; inspect supported MCS and then adjust
775		 * rate by channel width.
776		 */
777		txparams = htcap->hc_mcsset[12];
778		if (txparams & 0x3) {
779			/*
780			 * TX MCS parameters defined and not equal to RX,
781			 * extract the number of spartial streams and
782			 * map it to the highest MCS rate.
783			 */
784			txstream = ((txparams & 0xc) >> 2) + 1;
785			i = txstream * 8 - 1;
786		} else
787			for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--);
788		if (i >= 0) {
789			caps = LE_READ_2(&htcap->hc_cap);
790			if ((caps & IEEE80211_HTCAP_CHWIDTH40) &&
791			    (caps & IEEE80211_HTCAP_SHORTGI40))
792				rmax = ieee80211_htrates[i].ht40_rate_400ns;
793			else if (caps & IEEE80211_HTCAP_CHWIDTH40)
794				rmax = ieee80211_htrates[i].ht40_rate_800ns;
795			else if (caps & IEEE80211_HTCAP_SHORTGI20)
796				rmax = ieee80211_htrates[i].ht20_rate_400ns;
797			else
798				rmax = ieee80211_htrates[i].ht20_rate_800ns;
799		}
800	}
801	for (i = 0; i < se->se_rates[1]; i++) {
802		r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
803		if (r > rmax)
804			rmax = r;
805	}
806	for (i = 0; i < se->se_xrates[1]; i++) {
807		r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
808		if (r > rmax)
809			rmax = r;
810	}
811	return rmax;
812}
813
814/*
815 * Compare the capabilities of two entries and decide which is
816 * more desirable (return >0 if a is considered better).  Note
817 * that we assume compatibility/usability has already been checked
818 * so we don't need to (e.g. validate whether privacy is supported).
819 * Used to select the best scan candidate for association in a BSS.
820 */
821static int
822sta_compare(const struct sta_entry *a, const struct sta_entry *b)
823{
824#define	PREFER(_a,_b,_what) do {			\
825	if (((_a) ^ (_b)) & (_what))			\
826		return ((_a) & (_what)) ? 1 : -1;	\
827} while (0)
828	int maxa, maxb;
829	int8_t rssia, rssib;
830	int weight;
831
832	/* privacy support */
833	PREFER(a->base.se_capinfo, b->base.se_capinfo,
834		IEEE80211_CAPINFO_PRIVACY);
835
836	/* compare count of previous failures */
837	weight = b->se_fails - a->se_fails;
838	if (abs(weight) > 1)
839		return weight;
840
841	/*
842	 * Compare rssi.  If the two are considered equivalent
843	 * then fallback to other criteria.  We threshold the
844	 * comparisons to avoid selecting an ap purely by rssi
845	 * when both values may be good but one ap is otherwise
846	 * more desirable (e.g. an 11b-only ap with stronger
847	 * signal than an 11g ap).
848	 */
849	rssia = MIN(a->base.se_rssi, STA_RSSI_MAX);
850	rssib = MIN(b->base.se_rssi, STA_RSSI_MAX);
851	if (abs(rssib - rssia) < 5) {
852		/* best/max rate preferred if signal level close enough XXX */
853		maxa = maxrate(&a->base);
854		maxb = maxrate(&b->base);
855		if (maxa != maxb)
856			return maxa - maxb;
857		/* XXX use freq for channel preference */
858		/* for now just prefer 5Ghz band to all other bands */
859		PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan),
860		       IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1);
861	}
862	/* all things being equal, use signal level */
863	return a->base.se_rssi - b->base.se_rssi;
864#undef PREFER
865}
866
867/*
868 * Check rate set suitability and return the best supported rate.
869 * XXX inspect MCS for HT
870 */
871static int
872check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan,
873    const struct ieee80211_scan_entry *se)
874{
875#define	RV(v)	((v) & IEEE80211_RATE_VAL)
876	const struct ieee80211_rateset *srs;
877	int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate;
878	const uint8_t *rs;
879
880	okrate = badrate = 0;
881
882	srs = ieee80211_get_suprates(vap->iv_ic, chan);
883	nrs = se->se_rates[1];
884	rs = se->se_rates+2;
885	/* XXX MCS */
886	ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate;
887	fixedrate = IEEE80211_FIXED_RATE_NONE;
888again:
889	for (i = 0; i < nrs; i++) {
890		r = RV(rs[i]);
891		badrate = r;
892		/*
893		 * Check any fixed rate is included.
894		 */
895		if (r == ucastrate)
896			fixedrate = r;
897		/*
898		 * Check against our supported rates.
899		 */
900		for (j = 0; j < srs->rs_nrates; j++)
901			if (r == RV(srs->rs_rates[j])) {
902				if (r > okrate)		/* NB: track max */
903					okrate = r;
904				break;
905			}
906
907		if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) {
908			/*
909			 * Don't try joining a BSS, if we don't support
910			 * one of its basic rates.
911			 */
912			okrate = 0;
913			goto back;
914		}
915	}
916	if (rs == se->se_rates+2) {
917		/* scan xrates too; sort of an algol68-style for loop */
918		nrs = se->se_xrates[1];
919		rs = se->se_xrates+2;
920		goto again;
921	}
922
923back:
924	if (okrate == 0 || ucastrate != fixedrate)
925		return badrate | IEEE80211_RATE_BASIC;
926	else
927		return RV(okrate);
928#undef RV
929}
930
931static __inline int
932match_id(const uint8_t *ie, const uint8_t *val, int len)
933{
934	return (ie[1] == len && memcmp(ie+2, val, len) == 0);
935}
936
937static int
938match_ssid(const uint8_t *ie,
939	int nssid, const struct ieee80211_scan_ssid ssids[])
940{
941	int i;
942
943	for (i = 0; i < nssid; i++) {
944		if (match_id(ie, ssids[i].ssid, ssids[i].len))
945			return 1;
946	}
947	return 0;
948}
949
950#ifdef IEEE80211_SUPPORT_TDMA
951static int
952tdma_isfull(const struct ieee80211_tdma_param *tdma)
953{
954	int slot, slotcnt;
955
956	slotcnt = tdma->tdma_slotcnt;
957	for (slot = slotcnt-1; slot >= 0; slot--)
958		if (isclr(tdma->tdma_inuse, slot))
959			return 0;
960	return 1;
961}
962#endif /* IEEE80211_SUPPORT_TDMA */
963
964/*
965 * Test a scan candidate for suitability/compatibility.
966 */
967static int
968match_bss(struct ieee80211vap *vap,
969	const struct ieee80211_scan_state *ss, struct sta_entry *se0,
970	int debug)
971{
972	struct ieee80211com *ic = vap->iv_ic;
973	struct ieee80211_scan_entry *se = &se0->base;
974        uint8_t rate;
975        int fail;
976
977	fail = 0;
978	if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
979		fail |= MATCH_CHANNEL;
980	/*
981	 * NB: normally the desired mode is used to construct
982	 * the channel list, but it's possible for the scan
983	 * cache to include entries for stations outside this
984	 * list so we check the desired mode here to weed them
985	 * out.
986	 */
987	if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
988	    (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
989	    chanflags[vap->iv_des_mode])
990		fail |= MATCH_CHANNEL;
991	if (vap->iv_opmode == IEEE80211_M_IBSS) {
992		if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
993			fail |= MATCH_CAPINFO;
994#ifdef IEEE80211_SUPPORT_TDMA
995	} else if (vap->iv_opmode == IEEE80211_M_AHDEMO) {
996		/*
997		 * Adhoc demo network setup shouldn't really be scanning
998		 * but just in case skip stations operating in IBSS or
999		 * BSS mode.
1000		 */
1001		if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1002			fail |= MATCH_CAPINFO;
1003		/*
1004		 * TDMA operation cannot coexist with a normal 802.11 network;
1005		 * skip if IBSS or ESS capabilities are marked and require
1006		 * the beacon have a TDMA ie present.
1007		 */
1008		if (vap->iv_caps & IEEE80211_C_TDMA) {
1009			const struct ieee80211_tdma_param *tdma =
1010			    (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie;
1011			const struct ieee80211_tdma_state *ts = vap->iv_tdma;
1012
1013			if (tdma == NULL)
1014				fail |= MATCH_TDMA_NOIE;
1015			else if (tdma->tdma_version != ts->tdma_version)
1016				fail |= MATCH_TDMA_VERSION;
1017			else if (tdma->tdma_slot != 0)
1018				fail |= MATCH_TDMA_NOTMASTER;
1019			else if (tdma_isfull(tdma))
1020				fail |= MATCH_TDMA_NOSLOT;
1021#if 0
1022			else if (ieee80211_local_address(se->se_macaddr))
1023				fail |= MATCH_TDMA_LOCAL;
1024#endif
1025		}
1026#endif /* IEEE80211_SUPPORT_TDMA */
1027#ifdef IEEE80211_SUPPORT_MESH
1028	} else if (vap->iv_opmode == IEEE80211_M_MBSS) {
1029		const struct ieee80211_mesh_state *ms = vap->iv_mesh;
1030		/*
1031		 * Mesh nodes have IBSS & ESS bits in capinfo turned off
1032		 * and two special ie's that must be present.
1033		 */
1034		if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS))
1035			fail |= MATCH_CAPINFO;
1036		else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID)
1037			fail |= MATCH_MESH_NOID;
1038		else if (ms->ms_idlen != 0 &&
1039		    match_id(se->se_meshid, ms->ms_id, ms->ms_idlen))
1040			fail |= MATCH_MESHID;
1041#endif
1042	} else {
1043		if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
1044			fail |= MATCH_CAPINFO;
1045		/*
1046		 * If 11d is enabled and we're attempting to join a bss
1047		 * that advertises it's country code then compare our
1048		 * current settings to what we fetched from the country ie.
1049		 * If our country code is unspecified or different then do
1050		 * not attempt to join the bss.  We should have already
1051		 * dispatched an event to user space that identifies the
1052		 * new country code so our regdomain config should match.
1053		 */
1054		if ((IEEE80211_IS_CHAN_11D(se->se_chan) ||
1055		    (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) &&
1056		    se->se_cc[0] != 0 &&
1057		    (ic->ic_regdomain.country == CTRY_DEFAULT ||
1058		     !isocmp(se->se_cc, ic->ic_regdomain.isocc)))
1059			fail |= MATCH_CC;
1060	}
1061	if (vap->iv_flags & IEEE80211_F_PRIVACY) {
1062		if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
1063			fail |= MATCH_PRIVACY;
1064	} else {
1065		/* XXX does this mean privacy is supported or required? */
1066		if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
1067			fail |= MATCH_PRIVACY;
1068	}
1069	se0->se_flags &= ~STA_DEMOTE11B;
1070	rate = check_rate(vap, se->se_chan, se);
1071	if (rate & IEEE80211_RATE_BASIC) {
1072		fail |= MATCH_RATE;
1073		/*
1074		 * An 11b-only ap will give a rate mismatch if there is an
1075		 * OFDM fixed tx rate for 11g.  Try downgrading the channel
1076		 * in the scan list to 11b and retry the rate check.
1077		 */
1078		if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) {
1079			rate = check_rate(vap, demote11b(vap, se->se_chan), se);
1080			if ((rate & IEEE80211_RATE_BASIC) == 0) {
1081				fail &= ~MATCH_RATE;
1082				se0->se_flags |= STA_DEMOTE11B;
1083			}
1084		}
1085	} else if (rate < 2*24) {
1086		/*
1087		 * This is an 11b-only ap.  Check the desired mode in
1088		 * case that needs to be honored (mode 11g filters out
1089		 * 11b-only ap's).  Otherwise force any 11g channel used
1090		 * in scanning to be demoted.
1091		 *
1092		 * NB: we cheat a bit here by looking at the max rate;
1093		 *     we could/should check the rates.
1094		 */
1095		if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO ||
1096		      vap->iv_des_mode == IEEE80211_MODE_11B))
1097			fail |= MATCH_RATE;
1098		else
1099			se0->se_flags |= STA_DEMOTE11B;
1100	}
1101	if (ss->ss_nssid != 0 &&
1102	    !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
1103		fail |= MATCH_SSID;
1104	if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
1105	    !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
1106		fail |= MATCH_BSSID;
1107	if (se0->se_fails >= STA_FAILS_MAX)
1108		fail |= MATCH_FAILS;
1109	if (se0->se_notseen >= STA_PURGE_SCANS)
1110		fail |= MATCH_NOTSEEN;
1111	if (se->se_rssi < STA_RSSI_MIN)
1112		fail |= MATCH_RSSI;
1113#ifdef IEEE80211_DEBUG
1114	if (ieee80211_msg(vap, debug)) {
1115		printf(" %c %s",
1116		    fail & MATCH_FAILS ? '=' :
1117		    fail & MATCH_NOTSEEN ? '^' :
1118		    fail & MATCH_CC ? '$' :
1119#ifdef IEEE80211_SUPPORT_TDMA
1120		    fail & MATCH_TDMA_NOIE ? '&' :
1121		    fail & MATCH_TDMA_VERSION ? 'v' :
1122		    fail & MATCH_TDMA_NOTMASTER ? 's' :
1123		    fail & MATCH_TDMA_NOSLOT ? 'f' :
1124		    fail & MATCH_TDMA_LOCAL ? 'l' :
1125#endif
1126		    fail & MATCH_MESH_NOID ? 'm' :
1127		    fail ? '-' : '+', ether_sprintf(se->se_macaddr));
1128		printf(" %s%c", ether_sprintf(se->se_bssid),
1129		    fail & MATCH_BSSID ? '!' : ' ');
1130		printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
1131			fail & MATCH_CHANNEL ? '!' : ' ');
1132		printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' ');
1133		printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
1134		    fail & MATCH_RATE ? '!' : ' ');
1135		printf(" %4s%c",
1136		    (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
1137		    (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "",
1138		    fail & MATCH_CAPINFO ? '!' : ' ');
1139		printf(" %3s%c ",
1140		    (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
1141		    "wep" : "no",
1142		    fail & MATCH_PRIVACY ? '!' : ' ');
1143		ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]);
1144		printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : "");
1145	}
1146#endif
1147	return fail;
1148}
1149
1150static void
1151sta_update_notseen(struct sta_table *st)
1152{
1153	struct sta_entry *se;
1154
1155	IEEE80211_SCAN_TABLE_LOCK(st);
1156	TAILQ_FOREACH(se, &st->st_entry, se_list) {
1157		/*
1158		 * If seen the reset and don't bump the count;
1159		 * otherwise bump the ``not seen'' count.  Note
1160		 * that this insures that stations for which we
1161		 * see frames while not scanning but not during
1162		 * this scan will not be penalized.
1163		 */
1164		if (se->se_seen)
1165			se->se_seen = 0;
1166		else
1167			se->se_notseen++;
1168	}
1169	IEEE80211_SCAN_TABLE_UNLOCK(st);
1170}
1171
1172static void
1173sta_dec_fails(struct sta_table *st)
1174{
1175	struct sta_entry *se;
1176
1177	IEEE80211_SCAN_TABLE_LOCK(st);
1178	TAILQ_FOREACH(se, &st->st_entry, se_list)
1179		if (se->se_fails)
1180			se->se_fails--;
1181	IEEE80211_SCAN_TABLE_UNLOCK(st);
1182}
1183
1184static struct sta_entry *
1185select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug)
1186{
1187	struct sta_table *st = ss->ss_priv;
1188	struct sta_entry *se, *selbs = NULL;
1189
1190	IEEE80211_DPRINTF(vap, debug, " %s\n",
1191	    "macaddr          bssid         chan  rssi  rate flag  wep  essid");
1192	IEEE80211_SCAN_TABLE_LOCK(st);
1193	TAILQ_FOREACH(se, &st->st_entry, se_list) {
1194		ieee80211_ies_expand(&se->base.se_ies);
1195		if (match_bss(vap, ss, se, debug) == 0) {
1196			if (selbs == NULL)
1197				selbs = se;
1198			else if (sta_compare(se, selbs) > 0)
1199				selbs = se;
1200		}
1201	}
1202	IEEE80211_SCAN_TABLE_UNLOCK(st);
1203
1204	return selbs;
1205}
1206
1207/*
1208 * Pick an ap or ibss network to join or find a channel
1209 * to use to start an ibss network.
1210 */
1211static int
1212sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1213{
1214	struct sta_table *st = ss->ss_priv;
1215	struct sta_entry *selbs;
1216	struct ieee80211_channel *chan;
1217
1218	KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1219		("wrong mode %u", vap->iv_opmode));
1220
1221	if (st->st_newscan) {
1222		sta_update_notseen(st);
1223		st->st_newscan = 0;
1224	}
1225	if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1226		/*
1227		 * Manual/background scan, don't select+join the
1228		 * bss, just return.  The scanning framework will
1229		 * handle notification that this has completed.
1230		 */
1231		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1232		return 1;
1233	}
1234	/*
1235	 * Automatic sequencing; look for a candidate and
1236	 * if found join the network.
1237	 */
1238	/* NB: unlocked read should be ok */
1239	if (TAILQ_FIRST(&st->st_entry) == NULL) {
1240		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1241			"%s: no scan candidate\n", __func__);
1242		if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1243			return 0;
1244notfound:
1245		/*
1246		 * If nothing suitable was found decrement
1247		 * the failure counts so entries will be
1248		 * reconsidered the next time around.  We
1249		 * really want to do this only for sta's
1250		 * where we've previously had some success.
1251		 */
1252		sta_dec_fails(st);
1253		st->st_newscan = 1;
1254		return 0;			/* restart scan */
1255	}
1256	selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1257	if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1258		return (selbs != NULL);
1259	if (selbs == NULL)
1260		goto notfound;
1261	chan = selbs->base.se_chan;
1262	if (selbs->se_flags & STA_DEMOTE11B)
1263		chan = demote11b(vap, chan);
1264	if (!ieee80211_sta_join(vap, chan, &selbs->base))
1265		goto notfound;
1266	return 1;				/* terminate scan */
1267}
1268
1269/*
1270 * Lookup an entry in the scan cache.  We assume we're
1271 * called from the bottom half or such that we don't need
1272 * to block the bottom half so that it's safe to return
1273 * a reference to an entry w/o holding the lock on the table.
1274 */
1275static struct sta_entry *
1276sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN])
1277{
1278	struct sta_entry *se;
1279	int hash = STA_HASH(macaddr);
1280
1281	IEEE80211_SCAN_TABLE_LOCK(st);
1282	LIST_FOREACH(se, &st->st_hash[hash], se_hash)
1283		if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr))
1284			break;
1285	IEEE80211_SCAN_TABLE_UNLOCK(st);
1286
1287	return se;		/* NB: unlocked */
1288}
1289
1290static void
1291sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1292{
1293	struct ieee80211com *ic = vap->iv_ic;
1294	struct ieee80211_node *ni = vap->iv_bss;
1295	struct sta_table *st = ss->ss_priv;
1296	enum ieee80211_phymode mode;
1297	struct sta_entry *se, *selbs;
1298	uint8_t roamRate, curRate, ucastRate;
1299	int8_t roamRssi, curRssi;
1300
1301	se = sta_lookup(st, ni->ni_macaddr);
1302	if (se == NULL) {
1303		/* XXX something is wrong */
1304		return;
1305	}
1306
1307	mode = ieee80211_chan2mode(ic->ic_bsschan);
1308	roamRate = vap->iv_roamparms[mode].rate;
1309	roamRssi = vap->iv_roamparms[mode].rssi;
1310	ucastRate = vap->iv_txparms[mode].ucastrate;
1311	/* NB: the most up to date rssi is in the node, not the scan cache */
1312	curRssi = ic->ic_node_getrssi(ni);
1313	if (ucastRate == IEEE80211_FIXED_RATE_NONE) {
1314		curRate = ni->ni_txrate;
1315		roamRate &= IEEE80211_RATE_VAL;
1316		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1317		    "%s: currssi %d currate %u roamrssi %d roamrate %u\n",
1318		    __func__, curRssi, curRate, roamRssi, roamRate);
1319	} else {
1320		curRate = roamRate;	/* NB: insure compare below fails */
1321		IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
1322		    "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi);
1323	}
1324	/*
1325	 * Check if a new ap should be used and switch.
1326	 * XXX deauth current ap
1327	 */
1328	if (curRate < roamRate || curRssi < roamRssi) {
1329		if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
1330			/*
1331			 * Scan cache contents are too old; force a scan now
1332			 * if possible so we have current state to make a
1333			 * decision with.  We don't kick off a bg scan if
1334			 * we're using dynamic turbo and boosted or if the
1335			 * channel is busy.
1336			 * XXX force immediate switch on scan complete
1337			 */
1338			if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) &&
1339			    time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle))
1340				ieee80211_bg_scan(vap, 0);
1341			return;
1342		}
1343		se->base.se_rssi = curRssi;
1344		selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM);
1345		if (selbs != NULL && selbs != se) {
1346			struct ieee80211_channel *chan;
1347
1348			IEEE80211_DPRINTF(vap,
1349			    IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG,
1350			    "%s: ROAM: curRate %u, roamRate %u, "
1351			    "curRssi %d, roamRssi %d\n", __func__,
1352			    curRate, roamRate, curRssi, roamRssi);
1353
1354			chan = selbs->base.se_chan;
1355			if (selbs->se_flags & STA_DEMOTE11B)
1356				chan = demote11b(vap, chan);
1357			(void) ieee80211_sta_join(vap, chan, &selbs->base);
1358		}
1359	}
1360}
1361
1362/*
1363 * Age entries in the scan cache.
1364 * XXX also do roaming since it's convenient
1365 */
1366static void
1367sta_age(struct ieee80211_scan_state *ss)
1368{
1369	struct ieee80211vap *vap = ss->ss_vap;
1370
1371	adhoc_age(ss);
1372	/*
1373	 * If rate control is enabled check periodically to see if
1374	 * we should roam from our current connection to one that
1375	 * might be better.  This only applies when we're operating
1376	 * in sta mode and automatic roaming is set.
1377	 * XXX defer if busy
1378	 * XXX repeater station
1379	 * XXX do when !bgscan?
1380	 */
1381	KASSERT(vap->iv_opmode == IEEE80211_M_STA,
1382		("wrong mode %u", vap->iv_opmode));
1383	if (vap->iv_roaming == IEEE80211_ROAMING_AUTO &&
1384	    (vap->iv_flags & IEEE80211_F_BGSCAN) &&
1385	    vap->iv_state >= IEEE80211_S_RUN)
1386		/* XXX vap is implicit */
1387		sta_roam_check(ss, vap);
1388}
1389
1390/*
1391 * Iterate over the entries in the scan cache, invoking
1392 * the callback function on each one.
1393 */
1394static void
1395sta_iterate(struct ieee80211_scan_state *ss,
1396	ieee80211_scan_iter_func *f, void *arg)
1397{
1398	struct sta_table *st = ss->ss_priv;
1399	struct sta_entry *se;
1400	u_int gen;
1401
1402	mtx_lock(&st->st_scanlock);
1403	gen = st->st_scaniter++;
1404restart:
1405	IEEE80211_SCAN_TABLE_LOCK(st);
1406	TAILQ_FOREACH(se, &st->st_entry, se_list) {
1407		if (se->se_scangen != gen) {
1408			se->se_scangen = gen;
1409			/* update public state */
1410			se->base.se_age = ticks - se->se_lastupdate;
1411			IEEE80211_SCAN_TABLE_UNLOCK(st);
1412			(*f)(arg, &se->base);
1413			goto restart;
1414		}
1415	}
1416	IEEE80211_SCAN_TABLE_UNLOCK(st);
1417
1418	mtx_unlock(&st->st_scanlock);
1419}
1420
1421static void
1422sta_assoc_fail(struct ieee80211_scan_state *ss,
1423	const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason)
1424{
1425	struct sta_table *st = ss->ss_priv;
1426	struct sta_entry *se;
1427
1428	se = sta_lookup(st, macaddr);
1429	if (se != NULL) {
1430		se->se_fails++;
1431		se->se_lastfail = ticks;
1432		IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1433		    macaddr, "%s: reason %u fails %u",
1434		    __func__, reason, se->se_fails);
1435	}
1436}
1437
1438static void
1439sta_assoc_success(struct ieee80211_scan_state *ss,
1440	const uint8_t macaddr[IEEE80211_ADDR_LEN])
1441{
1442	struct sta_table *st = ss->ss_priv;
1443	struct sta_entry *se;
1444
1445	se = sta_lookup(st, macaddr);
1446	if (se != NULL) {
1447#if 0
1448		se->se_fails = 0;
1449		IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
1450		    macaddr, "%s: fails %u",
1451		    __func__, se->se_fails);
1452#endif
1453		se->se_lastassoc = ticks;
1454	}
1455}
1456
1457static const struct ieee80211_scanner sta_default = {
1458	.scan_name		= "default",
1459	.scan_attach		= sta_attach,
1460	.scan_detach		= sta_detach,
1461	.scan_start		= sta_start,
1462	.scan_restart		= sta_restart,
1463	.scan_cancel		= sta_cancel,
1464	.scan_end		= sta_pick_bss,
1465	.scan_flush		= sta_flush,
1466	.scan_add		= sta_add,
1467	.scan_age		= sta_age,
1468	.scan_iterate		= sta_iterate,
1469	.scan_assoc_fail	= sta_assoc_fail,
1470	.scan_assoc_success	= sta_assoc_success,
1471};
1472
1473/*
1474 * Adhoc mode-specific support.
1475 */
1476
1477static const uint16_t adhocWorld[] =		/* 36, 40, 44, 48 */
1478{ 5180, 5200, 5220, 5240 };
1479static const uint16_t adhocFcc3[] =		/* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */
1480{ 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 };
1481static const uint16_t adhocMkk[] =		/* 34, 38, 42, 46 */
1482{ 5170, 5190, 5210, 5230 };
1483static const uint16_t adhoc11b[] =		/* 10, 11 */
1484{ 2457, 2462 };
1485
1486static const struct scanlist adhocScanTable[] = {
1487	{ IEEE80211_MODE_11B,   	X(adhoc11b) },
1488	{ IEEE80211_MODE_11A,   	X(adhocWorld) },
1489	{ IEEE80211_MODE_11A,   	X(adhocFcc3) },
1490	{ IEEE80211_MODE_11B,   	X(adhocMkk) },
1491	{ .list = NULL }
1492};
1493#undef X
1494
1495/*
1496 * Start an adhoc-mode scan by populating the channel list.
1497 */
1498static int
1499adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1500{
1501	struct sta_table *st = ss->ss_priv;
1502
1503	makescanlist(ss, vap, adhocScanTable);
1504
1505	if (ss->ss_mindwell == 0)
1506		ss->ss_mindwell = msecs_to_ticks(200);	/* 200ms */
1507	if (ss->ss_maxdwell == 0)
1508		ss->ss_maxdwell = msecs_to_ticks(200);	/* 200ms */
1509
1510	st->st_scangen++;
1511	st->st_newscan = 1;
1512
1513	return 0;
1514}
1515
1516/*
1517 * Select a channel to start an adhoc network on.
1518 * The channel list was populated with appropriate
1519 * channels so select one that looks least occupied.
1520 */
1521static struct ieee80211_channel *
1522adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags)
1523{
1524	struct sta_table *st = ss->ss_priv;
1525	struct sta_entry *se;
1526	struct ieee80211_channel *c, *bestchan;
1527	int i, bestrssi, maxrssi;
1528
1529	bestchan = NULL;
1530	bestrssi = -1;
1531
1532	IEEE80211_SCAN_TABLE_LOCK(st);
1533	for (i = 0; i < ss->ss_last; i++) {
1534		c = ss->ss_chans[i];
1535		/* never consider a channel with radar */
1536		if (IEEE80211_IS_CHAN_RADAR(c))
1537			continue;
1538		/* skip channels disallowed by regulatory settings */
1539		if (IEEE80211_IS_CHAN_NOADHOC(c))
1540			continue;
1541		/* check channel attributes for band compatibility */
1542		if (flags != 0 && (c->ic_flags & flags) != flags)
1543			continue;
1544		maxrssi = 0;
1545		TAILQ_FOREACH(se, &st->st_entry, se_list) {
1546			if (se->base.se_chan != c)
1547				continue;
1548			if (se->base.se_rssi > maxrssi)
1549				maxrssi = se->base.se_rssi;
1550		}
1551		if (bestchan == NULL || maxrssi < bestrssi)
1552			bestchan = c;
1553	}
1554	IEEE80211_SCAN_TABLE_UNLOCK(st);
1555
1556	return bestchan;
1557}
1558
1559/*
1560 * Pick an ibss network to join or find a channel
1561 * to use to start an ibss network.
1562 */
1563static int
1564adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1565{
1566	struct sta_table *st = ss->ss_priv;
1567	struct sta_entry *selbs;
1568	struct ieee80211_channel *chan;
1569
1570	KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
1571		vap->iv_opmode == IEEE80211_M_AHDEMO ||
1572		vap->iv_opmode == IEEE80211_M_MBSS,
1573		("wrong opmode %u", vap->iv_opmode));
1574
1575	if (st->st_newscan) {
1576		sta_update_notseen(st);
1577		st->st_newscan = 0;
1578	}
1579	if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1580		/*
1581		 * Manual/background scan, don't select+join the
1582		 * bss, just return.  The scanning framework will
1583		 * handle notification that this has completed.
1584		 */
1585		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1586		return 1;
1587	}
1588	/*
1589	 * Automatic sequencing; look for a candidate and
1590	 * if found join the network.
1591	 */
1592	/* NB: unlocked read should be ok */
1593	if (TAILQ_FIRST(&st->st_entry) == NULL) {
1594		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1595			"%s: no scan candidate\n", __func__);
1596		if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1597			return 0;
1598notfound:
1599		/* NB: never auto-start a tdma network for slot !0 */
1600#ifdef IEEE80211_SUPPORT_TDMA
1601		if (vap->iv_des_nssid &&
1602		    ((vap->iv_caps & IEEE80211_C_TDMA) == 0 ||
1603		     ieee80211_tdma_getslot(vap) == 0)) {
1604#else
1605		if (vap->iv_des_nssid) {
1606#endif
1607			/*
1608			 * No existing adhoc network to join and we have
1609			 * an ssid; start one up.  If no channel was
1610			 * specified, try to select a channel.
1611			 */
1612			if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1613			    IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1614				struct ieee80211com *ic = vap->iv_ic;
1615
1616				chan = adhoc_pick_channel(ss, 0);
1617				if (chan != NULL)
1618					chan = ieee80211_ht_adjust_channel(ic,
1619					    chan, vap->iv_flags_ht);
1620			} else
1621				chan = vap->iv_des_chan;
1622			if (chan != NULL) {
1623				ieee80211_create_ibss(vap, chan);
1624				return 1;
1625			}
1626		}
1627		/*
1628		 * If nothing suitable was found decrement
1629		 * the failure counts so entries will be
1630		 * reconsidered the next time around.  We
1631		 * really want to do this only for sta's
1632		 * where we've previously had some success.
1633		 */
1634		sta_dec_fails(st);
1635		st->st_newscan = 1;
1636		return 0;			/* restart scan */
1637	}
1638	selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1639	if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1640		return (selbs != NULL);
1641	if (selbs == NULL)
1642		goto notfound;
1643	chan = selbs->base.se_chan;
1644	if (selbs->se_flags & STA_DEMOTE11B)
1645		chan = demote11b(vap, chan);
1646	if (!ieee80211_sta_join(vap, chan, &selbs->base))
1647		goto notfound;
1648	return 1;				/* terminate scan */
1649}
1650
1651/*
1652 * Age entries in the scan cache.
1653 */
1654static void
1655adhoc_age(struct ieee80211_scan_state *ss)
1656{
1657	struct sta_table *st = ss->ss_priv;
1658	struct sta_entry *se, *next;
1659
1660	IEEE80211_SCAN_TABLE_LOCK(st);
1661	TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
1662		if (se->se_notseen > STA_PURGE_SCANS) {
1663			TAILQ_REMOVE(&st->st_entry, se, se_list);
1664			LIST_REMOVE(se, se_hash);
1665			ieee80211_ies_cleanup(&se->base.se_ies);
1666			free(se, M_80211_SCAN);
1667		}
1668	}
1669	IEEE80211_SCAN_TABLE_UNLOCK(st);
1670}
1671
1672static const struct ieee80211_scanner adhoc_default = {
1673	.scan_name		= "default",
1674	.scan_attach		= sta_attach,
1675	.scan_detach		= sta_detach,
1676	.scan_start		= adhoc_start,
1677	.scan_restart		= sta_restart,
1678	.scan_cancel		= sta_cancel,
1679	.scan_end		= adhoc_pick_bss,
1680	.scan_flush		= sta_flush,
1681	.scan_pickchan		= adhoc_pick_channel,
1682	.scan_add		= sta_add,
1683	.scan_age		= adhoc_age,
1684	.scan_iterate		= sta_iterate,
1685	.scan_assoc_fail	= sta_assoc_fail,
1686	.scan_assoc_success	= sta_assoc_success,
1687};
1688IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default);
1689IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default);
1690
1691static void
1692ap_force_promisc(struct ieee80211com *ic)
1693{
1694	struct ifnet *ifp = ic->ic_ifp;
1695
1696	IEEE80211_LOCK(ic);
1697	/* set interface into promiscuous mode */
1698	ifp->if_flags |= IFF_PROMISC;
1699	ieee80211_runtask(ic, &ic->ic_promisc_task);
1700	IEEE80211_UNLOCK(ic);
1701}
1702
1703static void
1704ap_reset_promisc(struct ieee80211com *ic)
1705{
1706	IEEE80211_LOCK(ic);
1707	ieee80211_syncifflag_locked(ic, IFF_PROMISC);
1708	IEEE80211_UNLOCK(ic);
1709}
1710
1711static int
1712ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1713{
1714	struct sta_table *st = ss->ss_priv;
1715
1716	makescanlist(ss, vap, staScanTable);
1717
1718	if (ss->ss_mindwell == 0)
1719		ss->ss_mindwell = msecs_to_ticks(200);	/* 200ms */
1720	if (ss->ss_maxdwell == 0)
1721		ss->ss_maxdwell = msecs_to_ticks(200);	/* 200ms */
1722
1723	st->st_scangen++;
1724	st->st_newscan = 1;
1725
1726	ap_force_promisc(vap->iv_ic);
1727	return 0;
1728}
1729
1730/*
1731 * Cancel an ongoing scan.
1732 */
1733static int
1734ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1735{
1736	ap_reset_promisc(vap->iv_ic);
1737	return 0;
1738}
1739
1740/*
1741 * Pick a quiet channel to use for ap operation.
1742 */
1743static struct ieee80211_channel *
1744ap_pick_channel(struct ieee80211_scan_state *ss, int flags)
1745{
1746	struct sta_table *st = ss->ss_priv;
1747	struct ieee80211_channel *bestchan = NULL;
1748	int i;
1749
1750	/* XXX select channel more intelligently, e.g. channel spread, power */
1751	/* NB: use scan list order to preserve channel preference */
1752	for (i = 0; i < ss->ss_last; i++) {
1753		struct ieee80211_channel *chan = ss->ss_chans[i];
1754		/*
1755		 * If the channel is unoccupied the max rssi
1756		 * should be zero; just take it.  Otherwise
1757		 * track the channel with the lowest rssi and
1758		 * use that when all channels appear occupied.
1759		 */
1760		if (IEEE80211_IS_CHAN_RADAR(chan))
1761			continue;
1762		if (IEEE80211_IS_CHAN_NOHOSTAP(chan))
1763			continue;
1764		/* check channel attributes for band compatibility */
1765		if (flags != 0 && (chan->ic_flags & flags) != flags)
1766			continue;
1767		KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size"));
1768		/* XXX channel have interference */
1769		if (st->st_maxrssi[chan->ic_ieee] == 0) {
1770			/* XXX use other considerations */
1771			return chan;
1772		}
1773		if (bestchan == NULL ||
1774		    st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee])
1775			bestchan = chan;
1776	}
1777	return bestchan;
1778}
1779
1780/*
1781 * Pick a quiet channel to use for ap operation.
1782 */
1783static int
1784ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1785{
1786	struct ieee80211com *ic = vap->iv_ic;
1787	struct ieee80211_channel *bestchan;
1788
1789	KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP,
1790		("wrong opmode %u", vap->iv_opmode));
1791	bestchan = ap_pick_channel(ss, 0);
1792	if (bestchan == NULL) {
1793		/* no suitable channel, should not happen */
1794		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1795		    "%s: no suitable channel! (should not happen)\n", __func__);
1796		/* XXX print something? */
1797		return 0;			/* restart scan */
1798	}
1799	/*
1800	 * If this is a dynamic turbo channel, start with the unboosted one.
1801	 */
1802	if (IEEE80211_IS_CHAN_TURBO(bestchan)) {
1803		bestchan = ieee80211_find_channel(ic, bestchan->ic_freq,
1804			bestchan->ic_flags & ~IEEE80211_CHAN_TURBO);
1805		if (bestchan == NULL) {
1806			/* should never happen ?? */
1807			return 0;
1808		}
1809	}
1810	ap_reset_promisc(ic);
1811	if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) {
1812		/*
1813		 * Manual/background scan, don't select+join the
1814		 * bss, just return.  The scanning framework will
1815		 * handle notification that this has completed.
1816		 */
1817		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1818		return 1;
1819	}
1820	ieee80211_create_ibss(vap,
1821	    ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht));
1822	return 1;
1823}
1824
1825static const struct ieee80211_scanner ap_default = {
1826	.scan_name		= "default",
1827	.scan_attach		= sta_attach,
1828	.scan_detach		= sta_detach,
1829	.scan_start		= ap_start,
1830	.scan_restart		= sta_restart,
1831	.scan_cancel		= ap_cancel,
1832	.scan_end		= ap_end,
1833	.scan_flush		= sta_flush,
1834	.scan_pickchan		= ap_pick_channel,
1835	.scan_add		= sta_add,
1836	.scan_age		= adhoc_age,
1837	.scan_iterate		= sta_iterate,
1838	.scan_assoc_success	= sta_assoc_success,
1839	.scan_assoc_fail	= sta_assoc_fail,
1840};
1841IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default);
1842
1843#ifdef IEEE80211_SUPPORT_MESH
1844/*
1845 * Pick an mbss network to join or find a channel
1846 * to use to start an mbss network.
1847 */
1848static int
1849mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
1850{
1851	struct sta_table *st = ss->ss_priv;
1852	struct ieee80211_mesh_state *ms = vap->iv_mesh;
1853	struct sta_entry *selbs;
1854	struct ieee80211_channel *chan;
1855
1856	KASSERT(vap->iv_opmode == IEEE80211_M_MBSS,
1857		("wrong opmode %u", vap->iv_opmode));
1858
1859	if (st->st_newscan) {
1860		sta_update_notseen(st);
1861		st->st_newscan = 0;
1862	}
1863	if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
1864		/*
1865		 * Manual/background scan, don't select+join the
1866		 * bss, just return.  The scanning framework will
1867		 * handle notification that this has completed.
1868		 */
1869		ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
1870		return 1;
1871	}
1872	/*
1873	 * Automatic sequencing; look for a candidate and
1874	 * if found join the network.
1875	 */
1876	/* NB: unlocked read should be ok */
1877	if (TAILQ_FIRST(&st->st_entry) == NULL) {
1878		IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1879			"%s: no scan candidate\n", __func__);
1880		if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1881			return 0;
1882notfound:
1883		if (ms->ms_idlen != 0) {
1884			/*
1885			 * No existing mbss network to join and we have
1886			 * a meshid; start one up.  If no channel was
1887			 * specified, try to select a channel.
1888			 */
1889			if (vap->iv_des_chan == IEEE80211_CHAN_ANYC ||
1890			    IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) {
1891				struct ieee80211com *ic = vap->iv_ic;
1892
1893				chan = adhoc_pick_channel(ss, 0);
1894				if (chan != NULL)
1895					chan = ieee80211_ht_adjust_channel(ic,
1896					    chan, vap->iv_flags_ht);
1897			} else
1898				chan = vap->iv_des_chan;
1899			if (chan != NULL) {
1900				ieee80211_create_ibss(vap, chan);
1901				return 1;
1902			}
1903		}
1904		/*
1905		 * If nothing suitable was found decrement
1906		 * the failure counts so entries will be
1907		 * reconsidered the next time around.  We
1908		 * really want to do this only for sta's
1909		 * where we've previously had some success.
1910		 */
1911		sta_dec_fails(st);
1912		st->st_newscan = 1;
1913		return 0;			/* restart scan */
1914	}
1915	selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN);
1916	if (ss->ss_flags & IEEE80211_SCAN_NOJOIN)
1917		return (selbs != NULL);
1918	if (selbs == NULL)
1919		goto notfound;
1920	chan = selbs->base.se_chan;
1921	if (selbs->se_flags & STA_DEMOTE11B)
1922		chan = demote11b(vap, chan);
1923	if (!ieee80211_sta_join(vap, chan, &selbs->base))
1924		goto notfound;
1925	return 1;				/* terminate scan */
1926}
1927
1928static const struct ieee80211_scanner mesh_default = {
1929	.scan_name		= "default",
1930	.scan_attach		= sta_attach,
1931	.scan_detach		= sta_detach,
1932	.scan_start		= adhoc_start,
1933	.scan_restart		= sta_restart,
1934	.scan_cancel		= sta_cancel,
1935	.scan_end		= mesh_pick_bss,
1936	.scan_flush		= sta_flush,
1937	.scan_pickchan		= adhoc_pick_channel,
1938	.scan_add		= sta_add,
1939	.scan_age		= adhoc_age,
1940	.scan_iterate		= sta_iterate,
1941	.scan_assoc_fail	= sta_assoc_fail,
1942	.scan_assoc_success	= sta_assoc_success,
1943};
1944IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default);
1945#endif /* IEEE80211_SUPPORT_MESH */
1946
1947#if defined(__HAIKU__)
1948void
1949ieee80211_scan_sta_init()
1950{
1951	ieee80211_scanner_register(IEEE80211_M_STA, &sta_default);
1952	ieee80211_scanner_register(IEEE80211_M_IBSS, &adhoc_default);
1953}
1954
1955void
1956ieee80211_scan_sta_uninit()
1957{
1958	ieee80211_scanner_unregister(IEEE80211_M_STA, &sta_default);
1959	ieee80211_scanner_unregister(IEEE80211_M_IBSS, &adhoc_default);
1960}
1961#endif /* __HAIKU__ */
1962